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FIELD OF THE INVENTION The present invention relates to a filter module for a transaction processing system. BACKGROUND OF THE INVENTION WOSA/XFS (Windows Open Services Architecture for Extended Financial Services) is an emerging standard enabling financial institutions, whose branch and office solutions run on the Windows NT platform, to develop applications independent of vendor equipment. FIG. 1 shows the standard WOSA model in solid lines. Using this model, an application 10 communicates hardware requests 12 to various hardware devices in an ATM 14 via a WOSA manager 20 . The application issues transaction requests 12 which are hardware independent, and thus vendor independent. The requests are queued by the WOSA manager 20 which manages concurrent access to the ATM hardware 14 from any number of applications 10 . When a piece of hardware is installed on the ATM, it registers its controlling software, known as a service provider module (SPM) 30 , with the WOSA manager by using, for example, the Windows registry. The WOSA manager 20 is thus able to relay a hardware request 12 to an appropriate SPM 30 , using the Windows registry as a look-up table. The SPM 30 takes relayed hardware independent requests 16 from the WOSA manager and actuates the appropriate piece of hardware to process the requests. The results of a request can be returned to the application by an SPM 30 synchronously via the WOSA manager 20 or asynchronously directly to the application 10 . During development, it can be very difficult to debug a WOSA system, because at run-time a number of applications may be generating hardware requests and receiving responses either synchronously or asynchronously at any given time. Messages are transmitted via many routes at run-time and the operation of one application's requests and responses could interfere with those of another application. It can also be desirable in an installed system to keep track of or log the operation of sensitive parts of a WOSA system. It may be desirable to track applications who are requesting access to a cash dispenser and the responses of the cash dispenser to those requests. Also, for example, keeping track of the number of bad card reads might indicate the card reader is coming to the end of its life or needs cleaning. Similarly, the number of uses of the printer can be tracked to determine when the printer ribbon needs to be replaced, as well as numerous other examples. It is an object of the present invention to provide a filter module to solve these problems. SUMMARY OF THE INVENTION Accordingly, the present invention provides a filter module for a transaction processing system in which a transaction manager responsive to transaction requests from at least one applications and a service provider layer is adapted to relay transaction requests passed from said transaction manager to associated hardware for execution; said filter module being adapted to intercept transaction requests from said transaction manager to said service provider layer and to process said requests, said filter module being further adapted to intercept transaction responses from said service provider layer to said transaction manager and at least one application and to process said responses. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a standard WOSA single process transaction processing system including a filter module according to the invention (shown shaded); FIG. 2 shows an alternative transaction processing system including the filter module of FIG. 1 (shown shaded); FIG. 3 shows a server component of the transaction processing system of FIG. 2 in more detail; FIG. 4 is a schematic view of a portion of a Windows NT registry employed by a WOSA manager; and FIG. 5 is a schematic diagram of an ATM including a transaction processing system according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The standard WOSA model includes three layers, FIG. 1 . An application layer 10 issues transaction requests in the form of hardware independent Application Programming Interface (API) calls 12 to a WOSA Manager 20 layer in order to access services from a Service Provider 30 , 37 layer. All components exist within the same process (the Application's) and memory address space. WOSA is a classic single process model, where all components of the solution run in the same process. If a single thread within this process abends, it will normally take the entire process down. Although this is acceptable in non-critical applications, for example printing, it is not acceptable where security is involved and where detailed audit trails are required. The best example of this case is where ATM cash dispensing is involved. If the process abends while a dispense is taking place, the error needs to be recoverable in order to determine the disposition of the cash involved. In an alternative server model, FIG. 2 , the application 10 and WOSA Manager 20 exist within the same user application process. The WOSA manager 20 , however, communicates with stub Dynamic Link Libraries (DLLs) 35 each corresponding to a respective SPM 30 of FIG. 1 . Transaction requests 12 from the application layer 10 pass through the WOSA Manager 20 to the stub DLLs 35 , where the data is repackaged and passed across process boundaries to a server 40 running in a separate process, where the required transaction request is actually executed. Once a request is received, the server 40 communicates with SPM's 30 to execute the transaction request. In either model, any execution results are either passed back from the SPMs to the application 10 through the WOSA manager 20 (via the stub DLLs 35 in the case of FIG. 2 ) or directly to the application 10 . In a Windows NT operating system embodiment of the invention, the SPMs 30 generate windows events using a window handle nominated by an application, whereas in an embodiment of the invention using IBM's OS/2 operating system, the SPMs generate presentation manager events. In either case, the application 10 passes an identifier (either a window handle or presentation manager event) corresponding to the application itself (asynchronous) or the WOSA manager (synchronous) to an SPM so that the SPM knows where to send its response. Similarly, the stub modules 35 also communicate messages to the WOSA manager 20 via the operating system messenger, because the window handle or presentation manager event for the WOSA manager 20 will be included in the response returned from the server 40 . The method of response is therefore determined by the application 10 , depending on whether a transaction request issued is specified as synchronous (the server responds through the stub DLL mechanism) or asynchronous (the server responds via the Windows Event mechanism). Information is also accessible by both the application 10 and the SPMs using shared memory. When, for example, an SPM 30 wishes to transmit information to an application 10 , the SPM sends a WOSA call to the WOSA manager 20 which communicates with an operating system memory manager 55 to allocate the shared memory. Once allocated, then SPMs 30 in the server 40 process or applications 10 can read or write information from this shared memory. FIG. 3 , shows the server 40 in more detail. The server is a multi-threaded application supporting the simultaneous execution of transaction requests on all of its supported WOSA device classes explained below. The server 40 consists of the following major components: A server object 41 runs in its own thread and has responsibility for creating and monitoring memory ‘pipes’ 42 connecting the server process to respective stub DLLs 35 , running in the user application process. When the server object detects a transaction request packet from one of the stub DLLs 35 waiting in its associated ‘pipe’ 42 , it moves the packet into a master queue 43 and thus frees the pipe for more communications. The server also detects packets in the master queue 43 that are response packets from service provider modules 30 , and channels these back through the ‘pipes’ to the correct stub DLL 35 , which then passes the response back to the user application 10 via the WOSA Manager. The memory pipes 42 are implemented in a class including essentially three methods: readpipe( ), writePipe( ), querypipe( ) with the methods being passed an identifier corresponding to the stub DLL associated with the pipe. In the application process, a stub DLL 35 receives a WOSA transaction request from the transaction manager and calls the writePipe method to place the request in its pipe 42 . writePipe essentially writes a message to a designated location in shared memory with a flag indicating that the message needs to be read. Once the stub DLL 35 has written the message to the pipe, it then polls its pipe 42 continually using queryPipe to determine when a response has been sent from the server 41 or if the message has been read. Within the server process, the server object 41 continually polls each of the pipes 42 using the queryPipe method for each pipe in turn to determine if messages are waiting to be processed. If a pipe has a message, the server calls readpipe to read the message from the pipe, resets the message flag indicating that the message has been read and places the message in the master queue 43 . The server also interrogates the master queue 43 , and if a message for the server 41 is in the master queue 43 , the server 41 pops the messages from the queue and calls writePipe to place the message in the appropriate pipe and thereafter reverts back to querying the pipe for the next message. A client object 44 runs in its own thread and is responsible for creating and managing the supported service provider modules 30 below it. The client object 44 monitors the server master queue 43 and when it detects an inbound packet for one of its managed hardware devices, it moves the packet from the queue 43 on to a private queue 45 associated with a target device. Instances of service provider module objects 30 are created at startup time by the client. In the case of an ATM, objects would be instantiated for a journal printer, receipt printer, passbook printer, statement printer, deposit unit, cash dispenser, magnetic card reader/smart card reader, sensors and indicators unit, pinpad unit, encryptor unit, vendor dependant mode (VDM) unit, and text terminal unit. Each instantiation spawns its own control thread that is responsible for monitoring its own private queue 45 for requests that are placed there by the client object 44 . When an SPM object 30 detects a request waiting on its private queue 45 , or if there is a request pending execution and it is time to attempt to process pending requests again, the SPM object spawns an execution thread that handles the execution of that single request. The execution thread has the responsibility of processing the request to its conclusion, either returning the relevant data to the caller application 10 via events, marking the request as ‘pending’ on the queue 45 and completing, or returning a response by returning a completed packet back to the server queue 43 for transmission to the stub DLL 35 associated with that hardware device. Each SPM 30 converts all WOSA transaction requests into one or more generic commands that are processed by a layer of small hardware DLLs 46 . An Application Programming Interface (API) for each type of hardware device is published by the hardware vendor and consists of the minimum number of hardware level commands (example read_card on a magnetic stripe reader device, or dispense_cash on a dispenser) that can satisfy the complete set of WOSA transaction requests for that device type. For example, a respective hardware DLL is supplied for both an IBM Dispenser and an Olivetti dispenser. The user only has to change which DLL is active, by updating the Windows registry in order to switch between the different devices. At the application and server layers, nothing changes. The same is true for all device types. The Windows NT registry is a hierarchy of keys, FIG. 4 , each key containing one or more data values. The WOSA Manager 20 uses the system provided HKEY_CLASSES_ROOT key to store and obtain data on Logical Service Providers, for example, “msrspm”. The application 10 opens a service by providing the WOSA manager with that service's logical name. The manager finds the key entry, “msrspm” in the HKEY_CLASSES_ROOT\WOSA/XFS_ROOT\LOGICAL_SERVICES key for that service. One of the data fields, “provider”, within that key is an entry describing the service provider key name, “testmsr”. The manager then accesses the relevant service provider key within the HKEY_CLASSES_ROOT\WOSA/XFS_ROOT\SERVICE_PROVIDERS key, which will contain an entry describing the exact path to the physical dynamic link library (dll) that contains the executable code for that service provider, “d:\path\msrdll.dll”. In the conventional WOSA transaction processing system of FIG. 1 , the path to the physical file in the Windows registry will point to a service provider module 30 . For service providers who support the alternative server model of FIG. 2 , the path points to a stub DLL 35 . This stub DLL 35 will thus direct any WOSA transaction requests across the process boundary to the server 40 as described above. If some vendor devices do not support the alternative server model, because they do not provide stub modules, then their respective SPMs can communicate directly with the WOSA manager 20 within the same process, as in the case of the SPM 37 in FIG. 2 . In the server models of FIGS. 1 and 2 , the WOSA manager 20 can essentially regard any communication as being with a service provider layer. In the case of FIG. 1 , communication with the service provider layer is more direct with the manager 20 communicating with the SPM's 30 . In the case of FIG. 2 , communication is less direct with the stub modules 35 representing the interface between the WOSA manager and the service provider layer. In the present invention, one or more filter modules 36 are located in the communications channel between the WOSA manager and selected portions of the service provider layer, for example, the cash dispenser service provider module. This is accomplished during installation of the filter module, by updating the Windows registry with the location of the filter module 36 instead of the location of the appropriate SPM 37 in FIGS. 1 and 2 or stub module 38 in FIG. 2 . During installation, the filter module is also updated with the location of the SPM or stub module it has replaced. The filter module 36 of the present embodiment, monitors communications both from the manager 20 to the service provider layer and vice versa. In the case of the former, transaction requests are initially passed through to the filter module 36 from the WOSA manager, the filter module records these requests in a log 90 and then passes the requests on to the SPM or stub module. Before passing the request on, however, the filter module alters the contents of the transaction request to change the window handle identifier to which the SPM must return its response, to that of the window handle of the filter module. Thus, in the model of FIG. 1 , the transaction request is first recorded by the filter module in the log 90 , the window handle for the response is updated to that of the filter module and the original window handle destination for the response is saved, before passing the request to an SPM 37 . The SPM passes the request to the ATM hardware and receives a response. Regardless of whether the original transaction request required a synchronous or asynchronous response, the response is passed from the SPM back to the filter module, which records the response in the log 90 . The filter module now passes the response back to the destination originally specified in the transaction request, that is, the WOSA manager 20 for synchronous requests or the application 10 for asynchronous requests. In the case of FIG. 2 , the steps of recording the transaction request and relaying the request to the service provider layer are the same as for FIG. 1 , except that the requests are relayed to either a stub module 35 or a SPM 37 not compliant with the model of FIG. 2 . For asynchronous responses, the messages passed from the SPMs 30 to the application 10 , FIG. 3 , are now directed to the filter module 36 corresponding to the SPM. The filter module 36 receives the responses, records them in the log 90 and relays the responses to the application 10 . For synchronuous responses, the SPM's relay their responses through their associated queue 45 and then through to the stub modules 35 as normal. However, where a filter according to the present invention has been deployed, the stub modules 35 pass their response to the filter module 36 which records the response and relays the response to the WOSA manager 20 . It will be seen from the above embodiments, that neither the vendor SPM nor the application is aware that anything has happened and takes no part in the filter procedure. It will also be seen that filter modules can be cascaded, so that one or more filters each dedicated to a particular task can be set between the WOSA manager and the service provider layer. An example of a type of filter module which could operate with the filter module according to the invention, is a security module for checking an application's right to access hardware described in Applicant's co-pending British Patent Application No. 9801931.8 (IBM Docket No. UK9-98-009). The above description has extended only to traditional applications running on an ATM. However, a number of companies other than the Applicant, including Microsoft Corporation, Keybank incorporated of Cleveland, Ohio and Diebold Incorporated of Canton, Ohio have mooted the idea of using an automatic teller machine (ATM) to provide access to Internet services, for example, for executing financial transactions, ticket reservation and information retrieval. Thus, a web ATM (Automatic Teller Machine) includes appropriate Internet browser software, for example Internet Explorer from Microsoft as an application running with the transaction processing system according to the model of FIG. 1 or FIG. 2 . The browser takes the place of the application 10 of FIGS. 1 and 2 , and runs a Bank ATM Application written in the form of a page, or series of pages located on a bank web server (or cached on the local machine). The bank application, via its web pages, can prompt a web ATM user to swap web pages within the bank web site or to swap to web pages of any other web sites, for example, an airline web page or a supermarket web page. The ATM Application pages are able to call methods for reading the users card and PIN number, for example, thus verifying the user's identity. The ATM Application can then prompt the ATM user to swap to other sites by, for example, displaying buttons on the ATM screen which can be touched by the user to select a site. By swapping to other sites, for example, an Airline booking system site, the user can for example select a flight and pay for the flight directly from the ATM using the user's bank account information. Other sites could be utility company sites, at which the user could pay a bill, or supermarket sites, at which a user could cash in loyalty points. Thus, it will also be seen that the filter module and transaction processing system according to the invention can operate with more than one application 10 at any given time or, in the case of a web ATM, many web applications can run through the web browser along with conventional applications 10 .

A filter module for a WOSA/XFS transaction processing system is disclosed. The system includes a WOSA transaction manager which is responsive to transaction requests from at least one application. A service provider layer is adapted to relay transaction requests passed from the transaction manager to associated hardware for execution. The filter module is adapted to intercept transaction requests from the transaction manager to the service provider layer and to process the requests. The filter module is further adapted to intercept transaction responses form the service provider layer to the transaction manager and the at least one application and to process these responses.

BACKGROUND OF THE INVENTION [0001] I. Field of the Invention [0002] The present invention relates generally to the trailer hitch and, more particularly, to an improved fifth wheel hitch designed to better accommodate pulling forces and secure the kingpin on the tongue of a trailer to be towed by a vehicle. [0003] II. Description of the Prior Art [0004] People who live and work in urban and suburban areas often find themselves with the desire to “want to get away from it all.” They drive to secluded areas, where they can just relax. Others, desiring a more mobile lifestyle, have turned a trailer into their home. The question is, how to get their boats, campers, trailers, and the like from their busy lives to different locations. [0005] Pick-up trucks are often used to tow trailers. This creates a need for a towing hitch which can be affixed to the bed of a pick-up truck and both accommodate the pulling forces to which the trailer is exposed when traversing uneven terrains, and provide a latching mechanism which is both easy to operate as well as safe and reliable. Further, the hitch should be removable so that the truck bed can be freed of obstruction. [0006] To deal with the problem of traveling over uneven terrain with a trailer attached to a-towing vehicle, it is recognized that the hitch head should be allowed to tilt fore and aft, as well as side-to-side pivoting. The prior art has numerous examples of mechanisms to allow such tilting, most by a gimble arrangement. Allowing this movement reduces the strain placed on the latching mechanism of the hitch. Such movement however can create its own wear-and-tear on the tilting mechanism itself, creating additional repair and replacement costs. A need is therefore identified for a fifth wheel hitch assembly for coupling a trailer to a towing pick-up truck which allows for two degrees of movement of the head assembly, while at the same time reducing the friction caused by such movement. [0007] In addition to allowing the head assembly to tilt, the hitch assembly must effectively hold the kingpin of the trailer. When the towing vehicle comes to a stop, the trailer will continue to move forward, until it is interfered with by the trailer hitch. When the kingpin moves forward and is not completely surrounded by the latching mechanism, it will create a jolt along with a loud and disturbing sound. Moreover, the kingpin will wear on the unsupported area of the latching mechanism. [0008] Finally, the entire hitch assembly must not only be easily removable from the towing vehicle, but also must be easily adjustable on the truck bed of the towing vehicle. Fifth wheel hitches are typically bolted to the bed of the towing vehicle above its rear axle. However, when the trailer must be maneuvered in tight spaces, it is useful to be able to adjust fore/aft the location of the hitch assembly to a position nearer to the pickup's tailgate. OBJECTS [0009] It would be advantageous to provide a fifth wheel hitch which overcomes the known problems of the prior art hitches. It is an object of the present invention to provide a fifth wheel hitch, mountable on the bed of a towing vehicle, such as a pick-up truck. [0010] It is a further object of the present invention to provide a trailer hitch which, while bolted to the bed of the towing vehicle, can be adjusted and positioned in a longitudinal direction along a pair of rails. [0011] It is another object of the present invention to provide a trailer hitch which securely holds the trailer's kingpin within the hitch assembly. [0012] It is still another object of the present invention to provide a trailer hitch which can permit the vehicle being towed to adjust to the terrain on which the towing vehicle travels. SUMMARY OF THE INVENTION [0013] These objects are accomplished by the present invention which comprises a support frame having two horizontal support legs for mounting the trailer hitch to the towing vehicle, a spherical bearing mounted in the frame creating a ball joint, and a latch assembly affixed to the spherical bearing to allow the latch assembly to have two degrees of movement, and a head body to aid in guiding a kingpin into the latch assembly. The latch assembly comprises a base plate with two pivot pins extending upwardly, two pivotable jaws attached to the pivot pins, and a stationary release cam. One of the jaws is fixed at one elevation. The second jaw, can be vertically displaced so that it is either above the fixed jaw, or coplanar with the fixed jaw. A lever with a cam follower is used to elevate the vertically displaceable jaw. When a kingpin of a trailer is inserted into the head body, it is captured by the two jaws, and then locked into place. When the towing vehicle turns, or travels on uneven roads, the trailer adjusts accordingly as the base plate is attached to the spherical bearing. [0014] It is an advantage of the present invention that the latching assembly is movable along two degrees of movement namely, fore and aft and side-to-side or in pitch and yaw. These and other advantages, objects and features of the present invention will become apparent from the drawings, detailed description and claims which follow. BRIEF DESCRIPTION OF THE DRAWINGS [0015] [0015]FIG. 1 is a side perspective view from above of a preferred embodiment of the present invention; [0016] [0016]FIG. 2 is an exploded view of the base plate, the latching assembly and the head body of the trailer hitch of the present invention; [0017] [0017]FIG. 3 is a side perspective view of an alternative embodiment of the invention having a fixed mount; [0018] [0018]FIG. 4 is a perspective view of the head body removed to more clearly show the base plate assembly and the latching assembly; [0019] [0019]FIG. 5 is a side view of the base plate and latch assembly in its released position; [0020] [0020]FIG. 6 is a cross-sectional view of the preferred embodiment showing the base plate having a center pin passing thought a spherical bearing having a vertically disposed race; and [0021] [0021]FIG. 7 is a cross-sectional view of an alternative embodiment showing the base plate having a center pin passing through a spherical bearing having a horizontally disposed race. DETAILED DESCRIPTION OF THE INVENTION [0022] The present invention provides a fifth wheel trailer hitch. The invention is useable in a variety of towing vehicle. The invention is described in the context of a towing hitch for a 5 th wheel trailer as a specific example for illustrative purposes only. The appended claims are not intended to be limited to any specific example or embodiment in the following description. It will be understood by those skilled in the art that the present invention may be used in conjunction with a variety of towing devices, including, but not limited to, fifth wheel hitches. Further, in the drawings described below, the reference numerals are generally repeated where identical elements appear in more than one figure. [0023] Referring to the drawings, FIG. 1 shows the preferred embodiment of a trailer hitch 10 for use in flat bed and pick-up trucks when towing a 5 th wheel trailer. The trailer hitch has two side frame assemblies 12 and 14 , a top frame assembly 16 which joins the two side frame assemblies 12 and 14 in a parallel spaced relationship, a head body 18 , and a base assembly 20 (FIG. 2). Within the head body 18 there is a latching assembly 22 which is show in detail in the exploded view of FIG. 2. [0024] In FIG. 1, the side frame assemblies 12 and 14 each have a horizontal support leg 24 which supports two braces 26 . A mounting bracket 28 of a predetermined width having a pair of side members 30 is supported by a support leg 32 extending between the pair of braces 26 for the-mounting bracket 28 and the end portions of the horizontal support leg 24 . The mounting brackets 28 each have a pattern of apertures 34 formed therethrough. The apertures 34 are adapted to receive a fastener for connecting the side frame assemblies 12 and 14 to the top frame assembly 16 . [0025] The top frame assembly 16 has a front horizontal bar 36 and a rear horizontal bar 38 held in spaced relation by two spaced-apart cross bars 40 and 42 . Fasteners, as at 44 , are inserted into the apertures 34 of the U-shaped mounting bracket 28 and are received by the front and rear horizontal bars 36 and 38 . The pattern of apertures 34 in the mounting bracket 28 is adapted to allow selection of an elevation of the top frame assembly 16 above the horizontal support legs 24 . The head body 18 is mounted on the top frame assembly 16 . [0026] In the preferred embodiment illustrated in FIG. 1, the side frame assemblies 12 and 14 are mounted to the truck bed by a rail-latch assembly indicated generally by numeral 46 . Two guide rails 48 are adapted to be bolted to the upwardly facing surface of the bed of a towing vehicle and extend longitudinally in parallel spaced relation. The guide rails 48 each have two vertical sidewalls 50 (FIG. 1) extending perpendicularly from a base to form a guide channel 52 . The horizontal support leg 24 of the side frame assembly 12 and 14 ride on the base of the guide rails 48 and are straddled by the two sidewalls 50 . The horizontal support legs 24 of the side frame assemblies 12 and 14 are capable of sliding within the channels 52 , allowing the hitch assembly to be placed over the towing vehicles rear axles when traveling over-the-road or at a position nearer to the tailgate when backing and maneuvering in tight quarters. [0027] U-shaped clamps 54 bolted to the truck bed hold the horizontal support legs 24 of the side frame assemblies 12 and 14 down and function as a travel limiter. To fix the side frame assemblies 12 and 14 at a particular position along the rails 48 a locking structure shown in FIGS. 1 is used. The locking structure comprises a lever 56 , a latch pin 58 , and bracket 60 . [0028] The lever 56 is attached to the latching pin 58 by a link 62 . The lever 56 passes through an aperture in the bracket 60 . A coil spring 64 runs along the lever between the backside of the bracket 60 and a bolt (not shown) attached to the end of the lever 56 to urge the latch pin 58 to the right when viewed in FIG. 1. To disengage the locking structure and allow the hitch assembly to be longitudinally positioned, the user pulls the lever 56 to the left which, in turn, removes the latching pin 58 attached to the lever 56 from aligned holes in bracket 60 , U-shaped bracket 54 and rails 50 . The user then rotates the lever and the latching pin 58 . The coil spring 64 pulls the lever 56 and latching pin 58 against the bracket 54 . The rail latch assembly 46 is now able to slide to a particular maneuvering position. When the outer support frame is located at a particular position, the lock can be re-engaged. The user turns the lever 56 so that the latching pins 58 line up with a receiving hole on the bracket 54 and with a hole that is aligned with a like opening in the U-Shaped clamp bracket 54 , the sidewall 50 , and the horizontal support leg 24 of the side frame assemblies 12 and 14 . A tube runs transversely through the center of the horizontal support leg 24 and surrounds the latch pin 58 when the locking structure is engaged. [0029] In an alternative embodiment shown in FIG. 3, the side frame assemblies 12 and 14 are mounted at a fixed location on the towing truck bed. A flange plate 68 with side gussets 69 is welded to the outside surface of the horizontal support leg 24 . The flange plates 68 on each side have bolt receiving apertures for securing the side frame assembly to the bed of the towing vehicle by means of bolts, as at 70 . [0030] Once the entire hitch unit is attached to the towing-vehicle it is ready to receive the kingpin of a trailer. The kingpin latching assembly 22 of the present invention is shown in the exploded view of FIG. 2 and in a perspective subassembly view of FIG. 4 and comprises a pair of cooperating jaws 72 and 74 that must be placed in the open position shown in FIG. 4 to receive and capture the kingpin. Here, one somewhat U-shaped jaw 72 is mounted to pivot at a fixed elevation on the base plate 20 . A second, vertically displaceable U-shaped jaw 74 rests on the top surface of the fixed jaw 72 . Since both jaws are U-shaped, when the latch is open, due to a semicircular recess formed inwardly of mated edges 76 and 78 , the back leg 80 of the vertically displaceable jaw 27 is resting at an angle so that there is a gap between the front legs 82 of the two jaws. The towing vehicle can now be backed toward the trailer until the kingpin on the trailer passes into the U-shaped cut-out 84 in the top plate 85 of the head body 18 . As the trailer's kingpin then passes through the gap between the front edges 76 and 78 of the jaws and presses against the back legs of both jaws, the jaws pivot on the axis of the pivot pins 86 and 88 . When the edges of the vertically displaceable jaw 74 and the jaw 72 that is fixed in elevation becomes aligned, a return spring 90 forces the vertically displaceable jaw 74 downward so that the front edge surfaces 76 and 78 of the jaws 72 and 74 are both collinear and coplanar. The kingpin is then trapped in the circular aperture created by the two semicircular recesses formed in the front edge 76 and 78 of the jaws 72 and 74 . The cooperation between the front edges 76 and 78 of the two jaws prevent the jaws from opening up and releasing the kingpin. [0031] As a safety measure, to prevent the vertically displaceable jaw 74 from lifting clear of the fixed jaw 72 during travel, a safety pin 92 shown in FIGS. 1 - 3 is inserted into an aperture 94 on the side wall of the head body 18 and is threaded through a second aperture (not shown) which is aligned with the first aperture 94 . The safety pin 92 , when inserted into the aperture formed in the head body 18 , rests on the top of the two jaws 72 and 74 , and interferes with upward displacement of the vertically displaceable jaws 74 . The safety pin 92 is bent at a right angle at one end, and the bent tip portion 96 can be inserted into a notch 98 in an ear 99 extending from the sidewall of the head body 18 to prevent it from vibrating loose during travel. [0032] The entire latching assembly is mounted on a base plate 100 (FIG. 4). To detach the kingpin from the latching assembly, one merely needs to first remove the safety pin 92 from the head body 18 , and then turn a release handle 102 . The release handle 102 is attached to a hand lever 84 of a cam follower 106 . The cam follower 106 has a bore formed through it for receiving the pivot pin 88 therethrough. Formed into the base plate 100 is a cam surface 108 . As the cam follower 106 is rotated, the cam follower raises and falls as defined by the profile of the cam. The bottom of the vertically displaceable jaw 74 rests on the top of the cam follower 106 . When the cam follower 106 is raised, it pushes up on the vertically displaceable jaw 74 against the force of the return spring 90 , and the bottom surface of the vertically displaceable jaw 74 then slides onto the top surface of the fixed jaw 72 . The force of the kingpin acting on the front edges of the jaws 72 and 74 causes a gap there between to open, allowing the kingpin to move free of latching mechanism of the hitch unit. [0033] While the preferred embodiment discloses a cam and a cam follower arrangement for elevating the jaw 74 above the jaw 72 , those skilled in the art will appreciate that equivalent mechanical devices, such as sliding wedge or a lever mechanism can also be used. [0034] As seen in FIG. 2, in the preferred embodiment, a spherical bearing housing 110 allows the base plate 100 to accommodate towing forces to which it is exposed when traversing uneven terrain. A spherical bearing race 112 is secured in the bottom of the base plate 100 . A spherical bearing 114 is captive in the race 112 and held in place by a snap ring 113 . In this embodiment, the spherical race 112 is vertically disposed. A cylindrical center pin 116 (FIGS. 5 and 7) passes through a diametric bore formed through the spherical bearing 114 . The cylindrical center pin 116 is attached at opposed ends thereof to opposed, parallel assembly walls 118 of the head body by a pair of fasteners 120 . The base assembly with its spherical bearings 114 allows two degrees of freedom of movement, and provides a limit to the extent that the base plate 100 can tilt from side to side. [0035] A nub 111 is integrally attached to the bottom of the bearing housing 110 . A urethane filled cartridge 113 is affixed to the top of the nub 111 . The nub 111 has a threaded hole 115 which receives a bolt 115 for affixing the urethane filled cartridge 113 to the nub 111 . The urethane is of a compliance to absorb the shock created when the kingpin is received by the latch jaws 72 and 74 . [0036] In an alternative embodiment shown in FIG. 7 a vertical center pin 121 extends downward from the midpoint of the underside of the base plate 100 . The spherical race 122 is horizontally disposed. The vertical center pin 121 passes through a diametric bore formed through the spherical bearing 123 . [0037] The use of the spherical bearing assembly allows the base plate 100 to accommodate towing forces to which it is exposed when traversing uneven terrain or when, for example, one wheel of the trailer is made to ride over a speed bump, or curb, or the like. Two restraint devices 124 extend vertically downward from the underside of the base plate 100 . The restraint devices 124 are disposed proximate the front and rear edges of the base plate 100 . When the head body 18 is attached to a trailer kingpin and the trailer is turned, a rotating moment is developed about vertical pin 120 . Restraint device 124 limits the extent of rotation to the size of the apertures through which they protrude. [0038] Various alterations and modifications to the present invention will, no doubt, occur to those skilled in the towing art. It is the following claims, including all equivalents, which define the scope of the present invention.

An improved fifth wheel hitch for attaching a trailer to a towing vehicle. The hitch includes an outer box support frame having two rails for mounting the trailer hitch to the towing vehicle, a spherical bearing mounted in the frame having a ball joint, and a latch assembly affixed to the spherical bearing to allow the assembly to have two degrees of movement, and a head body. The latch assembly comprises a base plate, a jaw fixed at a first elevation, and a vertically displaceable jaw. A means are provided to raise the vertically displaceable jaw above the level of the fixed jaw to allow release of the king pin latch. When the jaws are coplanar they capture the kingpin of a trailer, and safely lock the trailer to the hitch.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority and is based upon U.S. Provisional Patent Application Ser. No. 61/247,126, filed Sep. 30, 2009. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not applicable. REFERENCE TO MICROFISHE APPENDIX [0003] Not applicable. BACKGROUND OF THE INVENTION [0004] 1. Field of the Invention [0005] The invention relates to electrical power distribution systems and, more particularly, to systems employing modular components with the capability of utilizing junction blocks for providing various types of circuit configurations, and electrically interconnecting outlet receptacle blocks so as to provide for interconnecting various types of international outlet receptacles. [0006] 2. Background Art [0007] It is known to utilize power distribution systems with various types of physical structures, including modular distribution systems for use with wall panels, work surfaces and the like. Such distribution systems can include what are often characterized as raceway systems, although actual “raceways” may not be utilized. The raceway distribution systems can include a series of cables and junction blocks, with the junction blocks having the capability of selectively being interconnected to one or more electrical outlet receptacles mounted in the junction blocks. Incoming power is supplied to the junction blocks (and to the interconnected outlet receptacles) through power cables which may be “hard-wired” to the junction blocks, or otherwise releasably connectible to the junction blocks. [0008] The receptacles may be positioned on one or on two opposing sides of the junction blocks. Further, the outlet receptacles may be in the form of single or “simplex” outlet receptacles. Alternatively, it is known to “bundle” outlet receptacles in “receptacle blocks.” A receptacle block may include two (i.e., duplex), three (i.e. triplex), or more receptacles. [0009] Still further, the junction blocks and the receptacles may be formed as a single unit which are manufactured together or otherwise or assembled together at the factory. Such configurations are typically characterized as being “integral” units, or junction blocks and outlet receptacles which are “hard-wired” together. Alternatively, the receptacles (or receptacle blocks) may be releasably, mechanically and electrically coupled together “on-site” (i.e., where the distribution system is actually being installed and will be in use). [0010] Various problematic issues exist with respect to usage of power distribution systems with electrical receptacles. During the past two decades, a substantial amount of research and development have been directed to raceways, junction blocks and receptacles, means for interconnection of the junction blocks and receptacles, and mounting of the junction blocks within the raceways. One aspect of the increasing use of electrical power relates to circuit loads. Any particular electrical circuit is limited to carrying a finite power load. Previously, when electrical power was not used to the extent that it is today, a single electrical circuit interconnecting to an incoming power supply was typically sufficient to handle power requirements. Accordingly, wiring within stationery or movable walls (or other wiring configurations) could comprise only two (hot and neutral) or three (hot, neutral and ground) wires, with receptacle blocks having simplex or duplex receptacles typically wired directly to the incoming two or three-wire circuit. However, today, it is advantageous to employ systems having an incoming power supply comprising multiple electrical circuits. The development of modular systems has advantageously provided for facilitating various circuit configurations and reconfigurations at locations of use. [0011] For example, power distribution system design often requires a reasonable balancing of loads among incoming circuits. However, having the ability of multiple circuits has led to other electrical wiring issues. For example, a number of junction blocks and outlet receptacle blocks may be assembled within several raceways of a modular system, with wiring and bus bars configured for interconnection of the outlet receptacles for a particular one of the available multiple circuits. However, over time, electrical power loads may change, resulting in load balance problems and the like. These changes may require circuit reconfigurations involving substantial rewiring and “change out” of junction blocks, receptacles and other electrical components to other devices having different wire and bus bar configurations, so as to accommodate circuit changeovers. In the past, many junction block and receptacle designs could handle only a single incoming power circuit (and pass-through of the incoming circuit “down the line”). To connect junction blocks and receptacles to differing circuits, differently wired junction blocks and differently wired receptacles were required to be used. [0012] Today, however, junction blocks are commercially available which provide for the capability of receiving (and passing through) incoming power from multiple circuits. Still, however, even with multiple incoming circuits to the junction blocks, differing outlet receptacle modules have been required to provide electrical connections to different ones of the separate circuits. A disadvantage of this arrangement has been that a separate supply receptacle module must be kept, and a receptacle module of proper type must be found each time a change is to be made to a different circuit arrangement. This presented substantial inconveniences to the user and required substantial and separate stocking of parts. [0013] A substantial advance was made with respect to receptacle blocks having multiple outlet receptacles and capable of being arranged for use with multiple circuit configurations in commonly owned Byrne U.S. Pat. No. 7,410,379, issued Aug. 12, 2008. In the Byrne patent, outlet receptacle blocks were provided having circuit means for electrically and selectively coupling the receptacle blocks to power supply means through the junction blocks, in a series of special orientations. In this manner, any one of a plurality of power supply circuits could be coupled to the receptacle blocks. [0014] In addition to the issues associated with multiple circuit configurations, existing issues also exist with respect to the capability of power distribution design and modularity regarding different “types” of receptacles, with respect to power, data and other energy connectors. That is, junction blocks are wired so as to be physically and electrically connectible to a particular “type” of receptacle block, at least with respect to physical structure and wiring. Correspondingly, the junction blocks and the internal wiring of receptacle blocks are configured so as to be electrically connected to only a single type of outlet receptacle configuration. In the past, this limitation with respect to the usage of particular outlet receptacles has not present significant problems, in that power distribution systems have been typically designed for use in one particular country. For example, in the U.S., the vast majority of power distribution systems and electrical appliances use a very limited number of electrical outlet receptacle types. [0015] However, with the global economy and commerce, power distribution systems are being marketed and used in a variety of developed and developing countries. However, with known systems, differently wired power distribution systems (with respect to junction blocks and other modular electrical components) must be wired differently and configured differently, depending upon the electrical requirements of the particular county in which the systems will be used. The various countries have a substantial number of different types of wiring and outlet receptacle requirements. Accordingly, it would be advantageous if a system could be developed which could accommodate different users in different countries, while still retaining modularity and a limited number of electrical components being required to have differing wiring configurations. [0016] The following paragraphs briefly describe certain known systems utilizing various types of modular electrical components, both within wall panels, various raceway configurations, and other system designs. [0017] One example of a prior art system is illustrated in Propst, et al., U.S. Pat. No. 4,382,648 issued May 10, 1983. In the Propst, et al. system, mating connectors of opposing panels are engaged when the panels are aligned in a straight line. When the panels are positioned in an intersecting relationship, specially manufactured couplers are utilized. One type of special coupler is used when the panels are positioned at right angles. Another type is used with adjoining panels arranged at angles other than right angles. Consequently, costly inventory of couplers must be maintained. The Propst, et al. system uses a double set of connectors comprising a male and female connector for each conductor to be interconnected. When a single one of these prior art panels intersects two adjacent panels, one of the specially manufactured couplers connects the female terminals to one of the adjacent panels, and another of the couplers connects the male terminals to the adjacent panel. [0018] A further system is disclosed in Driscoll, U.S. Pat. No. 4,135,775, issued Jan. 23, 1979. In the Driscoll system, each panel is provided with an electrical outlet box in its raceway. Panels of different widths are provided with a pair of female connectors. Outlet boxes of adjacent panels are interconnected by means of flexible cables having male connectors at both ends. When three or four panels are adjoined in an intersecting arrangement, two cables may be connected the pair of female connectors at one end of an outlet box. In this manner, connection of two adjacent panels is facilitated. [0019] With respect to both of the foregoing systems, and other than in the special intersecting relationship, one half of the double set of terminals of these systems is superfluous. There is a distinct disadvantage in modern day systems, where several independent electrical circuits are needed in a wall panel system, with each requiring separate connectors. Space for such circuits and their connectors is very limited in the raceway areas of modern, thin-line wall panels. [0020] Other systems also exist with respect to electrical connectors, junction boxes, and the like. For example, Rodrigues, U.S. Pat. No. 1,187,010 issued Jun. 13, 1916, discloses a detachable and interchangeable electrical switch plug adapted for use in connection with various electrically heated appliances. A clamping device is positioned in a fixed, but detachable relationship to one end of the plug. Means are provided to enclose and prevent sharp flexure of the cord comprising a flexible enclosing tube gripped under tension by the other end of the clamping device. The plug and the clamping device may be simultaneously removed from the socket. [0021] Finizie, U.S. Pat. No. 2,540,575, issued Feb. 6, 1951, discloses a cord guide member for utensil plugs. The concept is to reduce wear on the cord and the connector plug, and to provide a connection which will withstand heavy pulling strains without injury. Strain relief is also provided. A sectional body is equipped anteriorally adjacent one end of the body with terminals. The other end of the body contains an anterior chamber or socket. A pivotable cord-guiding member having a pivot member is movably mounted in the socket. A wedge-shaped strain relief insert is received within a wedge-shaped recess in the pivot member. A cord extends into the pivot member and includes wires passing from the cord toward the terminals. The incoming portions of the wires are moved around the insert and firmly wedged within the recess. [0022] Byrne, U.S. Pat. No. 4,551,577, issued Nov. 5, 1985, describes a retractable power center. The power center provides for conveniently located electrical power source receptacles adapted to be mounted on a work surface. In one embodiment, the power center includes a rectangular housing received within a slot in a work surface. A clamping arrangement is utilized to secure the housing to the work surface. A lower extrusion is connected to the lower portion of the housing. A movable power carriage mounts the receptacles and a catch assembly releasably maintains a carriage in a closed and retracted position. In response to manual activation, the catch assembly is released and springs tensioned between the carriage and the extrusion exert forces so as to extend the carriage upward into an extended, open position. In the open position, the user can energize the desired electrical devices from the receptacles, and then lower the carriage into the retracted position. [0023] Byrne, U.S. Pat. No. 4,959,021, issued Sep. 25, 1990, discloses a pivotable power feed connector having a pivotal connector adapted to be connected to a flexible conduit or cable. The cable has a series of conductors extending there through. The connector is pivotably connected to a block assembly through which the conductors extend. The block assembly, in turn, is connectable to a contact block, with the conductors conductively connected to a set of prong terminals extending outwardly from the block. A cover is secured over the block so as to prevent the prong terminals from being exposed during assembly and disassembly. [0024] The cover automatically exposes the prong terminals as the power feed connector is moved into engagement with a receptacle in a modular office panel. The connector allows the conduit or cable to be swiveled to an arc of approximately 180 degrees to any desired position. The connector is also manually removable from interconnection with the block assembly. Such removal allows the conduit or cable to be pulled back from the conductors and cut to a desired length. The connector includes a power feed cover which can be utilized in part to maintain the connector in either of two spatial configurations relative to the block assembly. [0025] Nienhuis, et al., U.S. Pat. No. 5,013,252, issued May 7, 1991, discloses an electrified wall panel system having a power distribution server located within a wall panel unit. The server includes four receptacle module ports oriented in an h-shaped configuration. A first receptacle port is located on the first side of the wall panel unit and opens toward a first end of the unit. A second receptacle unit is also located on the first side of the wall panel unit, and opens toward a second end of the wall panel unit. A third receptacle port and a second sided wall panel unit opens toward the first end of the wall panel unit, while correspondingly, a fourth receptacle port on the second side of the wall panel unit opens toward the second end of the wall panel unit. First and second harnesses are each electrically connected at first ends thereof to the power distribution server. They extend to opposite ends of the wall paneled unit and include connector ports on the second ends thereof for providing electrical interconnection of adjacent wall panel units. The Nienhuis, et al. patent also discloses a system with a wall panel connector interchangeably usable with the interconnection of two, three or four units. The connector includes a hook member for connecting together adjacent vertical members of frames of adjacent wall panel units at a lower portion thereof. A draw naught for connecting together adjacent vertical members of frames of adjacent wall panel units and an odd proportion thereof is provided by vertical displacement thereof. [0026] Lincoln, et al. U.S. Pat. No. 5,073,120, issued Dec. 17, 1991, discloses a power distribution assembly having a bussing distribution connector. The connector includes a series of bus terminals positioned within an electrically insulative housing. A series of electrical terminals are positioned in the housing for distributing more than one electrical circuit. At least one ground terminal, one neutral terminal, and three hot terminals are provided. A grounding shell partially surrounds the bus connector and includes a grounding tab grounding the one ground terminal to the metallic grounding shell. In another embodiment, two bus connectors are interconnected together, so as to provide for an increased number of output ports. [0027] Byrne, U.S. Pat. No. 5,096,431, issued Mar. 17, 1992, discloses an outlet receptacle with rearrangeable terminals. The receptacle is provided with input terminals to selected positions, for engagement with terminals of an electrical junction block. The block includes a series of terminals representing a plurality of different electrical circuits. The receptacle block has neutral, ground and positive flexible positive conductor bars electrically connected to neutral, ground and positive electrical terminals. Input terminals of the block are formed integral with the flexible conductor bars and levers are provided for moving the terminal ends of the conductor bars to physically different positions. In one configuration, the receptacle block housing is provided with openings at opposing ends, and the flexible conductor bars have terminal ends controlled by levers at both ends of the outlet receptacle block. In another configuration, the block has output terminals in a front wall, and the input terminals of the receptacle block are formed as ends of the flexible bars and extend at an approximately 90 degree angle to the bars. They further send through openings in the back wall of the outlet receptacle for engagement with terminals of a junction block. Levers are provided in the back wall of the receptacle block for positioning the terminal ends in alignment with different terminals of the junction block, and windowed openings in the front wall expose indices on the levers identifying selected circuits. [0028] Byrne, U.S. Pat. No. 5,096,434, issued Mar. 17, 1992, discloses an electrical interconnection assembly for use in wall panels of a space divider wall system. The system includes junction blocks having several receptacle connectors, so as to provide a plurality of electrical outlets on both sides of a wall panel. The junction block is connected by means of conduits extending from both ends of the junction block to oppositely directed connector blocks for connection to adjoining panels. The assembly of the junction block and connector blocks allows electrical power to be supplied to one end of the panel and conducted to and through the junction block to other panels. The receptacle connectors on the junction block each have one type of terminal configuration, e.g., a female electrical terminal configuration. One of the connector blocks is provided with the identical terminal configuration. The other connector block is provided with a matching terminal configuration, e.g., a male electrical terminal configuration. When two wall panels are joined at their respective edges, the male connector block may be readily connected to the female connector block in the adjacent panel. When two panels are joined to a third panel, all at one point, the arrangement of this invention allows the male connector block to be connected to the female connector block of one of the other two panels, and the male connector of the other of the two panels may be connected to one of the receptacle connectors of the junction block on either of the other two panels, in this manner establishing a three way interconnection arrangement. In a similar fashion, a fourth, or other additional panels may be added to the junction and plug into receptacle outlets of other panels in order to provide an arrangement of panels that is totally interconnected, electrically. [0029] Snodgrass, et al., U.S. Pat. No. 5,164,544, issued Nov. 17, 1992, describes an electrified space dividing panel having a panel member, raceway, modular, or electric system disposed in a raceway and raceway covers for gaining access to the system. The system includes a single terminal block having end and side sockets, with first and second electrical receptacles being respectively removeably engaged with the end socket and the side sockets, such that the first and second electrical receptacles are disposed in horizontally spaced, side-by-side relation and project outwardly for predetermined light dimensions through receptacle openings in one of the raceway covers. The raceway can include a web having an opening which cooperates with a support ear on the first receptacle during engagement of the first receptacle with an end socket, so as to provide additional lateral support for the electrical receptacle when a plug is removed there from. [0030] Kilpatrick, et al., U.S. Pat. No. 5,178,555, issued Jan. 12, 1993, discloses a kit which includes a junction box for installation along a raceway. The kit includes a mounting bracket having a first adjustable mounting mechanism for locating the bracket along the raceway. This provides an initial adjustment, and a second adjustable mounting mechanism is provided for securing the junction box to the mounting bracket. This adjustably locates the junction box along the mounting bracket, and provides a second or final adjustment to accurately locate the junction box between two pre-measured lengths of cable. [0031] Byrne, U.S. Pat. No. 5,259,787, issued Nov. 9, 1993, discloses an electrical junction block mounting assembly, which may be utilized for mounting the junction block within a raceway. The assembly includes a cantilever beam formed on an outer wall of the junction block. This beam is provided with a transversely extending channel for engagement with a support structure. The beam is attached to the junction block by means of a resilient hinge section, and is provided with a first arm section extending between the hinge section and the channel, and a second arm section extending beyond the channel. The first arm section has a sloping surface sloping away from the outer channel between the hinge section of the panel. The second armed section has a sloping surface sloping toward the wall beyond the channel. The surfaces will contact a mounting rail or similar structure during installation of the junction block. In this manner, the hinged cantilever beam is deflected until the rail is in alignment with the channel for engagement with the structural support member. SUMMARY OF THE INVENTION [0032] In accordance with the invention, an international power distribution system is adapted for use to energize outlet receptacles of various types. The power distribution system includes an incoming power cable assembly connected to a source of incoming power. A series of junction block assemblies are also provided, with at least a first one of the assemblies being electrically coupled, directly or indirectly, to the source of incoming power. A series of cable assemblies are electrically and mechanically interconnected to at least a subset of the junction block assemblies. The junction block assemblies include receptacle receiving means capable of energizing, from the source of incoming power, a series of alternative, differing international outlet receptacles having various types of outlet sockets, without requiring any electrical or mechanical modifications to the junction block assemblies. [0033] In one aspect, the outlet receptacles include a Type F outlet receptacle. In accordance with another aspect of the invention, the outlet receptacles comprise a Type I receptacle, having a ground pin and a pair of live pins forming a V-shape. Still further, the outlet receptacles can comprise a Type J receptacle. In addition, the outlet receptacles can include a Type B NEMA 5 receptacle. Still further, the outlet receptacles can comprise a Type B receptacle. In addition, the outlet receptacles can comprise a Type G or 13 amp receptacle. [0034] In accordance with other aspects of the invention, the junction block assemblies can each comprise a junction block and a pair of junction block end connectors located at opposing ends of the junction block. The receptacle receiving means are located within the junction blocks. Each of the junction block assemblies can include at least one junction block. The receptacle receiving means can include, for each of the junction blocks, a pair of receiving sections located in a face of the junction block, for receiving a pair of the outlet receptacles. Each of the pair of the outlet receptacles can be of a different type and configuration from the other of the pair of outlet receptacles. [0035] Still further, with each of the junction block assemblies comprising a junction block, the receptacle receiving means can comprise a set of three receiving sections for each of the junction blocks, located in a face of the junction block, for receiving three of the outlet receptacles. Each of the three outlet receptacles can be of a different type and configuration from the other two of the three outlet receptacles. In addition, each of the junction block assemblies can include a junction block, and the receptacle receiving means can comprise, for at least one of the junction blocks, a set of four receiving sections located in a face of the junction block. The receiving sections receive four of the outlet receptacles, with each of the outlet receptacles being of a differing type and configuration from the other three of the outlet receptacles. [0036] At least a subset of the cable assemblies can comprise jumper cable assemblies, with each of the jumper cable assemblies having a cable connected at its ends to a pair of opposing end connectors. Still further, at least a subset of the outlet receptacles may be polarized. In addition, the incoming power cable assembly can correspond in structure and configuration at least a subset of the series of cable assemblies. [0037] The power distribution system can include means for interconnecting a pair of cable assemblies, in an electrical and mechanical structure to one of the end connectors of one of the subsets of the junction block assemblies. Still further, the means for interconnecting a pair of cable assemblies can include a quad connector. Still further, the power distribution system can include means for coupling each of the junction blocks of the subset of the junction blocks to a vertically disposed wall element. BRIEF DESCRIPTION OF THE DRAWINGS [0038] The invention will now be described with reference to the drawings, in which: [0039] FIG. 1 is a perspective view of a pair of work surfaces having junction blocks and electrical receptacle blocks in accordance with the invention; [0040] FIG. 2 is an enlarged view of a portion of the illustration shown in FIG. 1 ; [0041] FIG. 3 is a perspective view of a pair of adjacent wall panels and electrical interconnection assemblies arranged in the panels, with the interconnection assemblies being part of a distribution system in accordance with the invention; [0042] FIG. 4 is an enlarged view of a portion of the distribution system shown in FIG. 3 , and specifically formed within circle 4 of FIG. 3 ; [0043] FIG. 5 is a rear view of a junction block in accordance with the invention; [0044] FIG. 6 is a plan view of a junction block in accordance with the invention; [0045] FIG. 7 is a left-side elevation view of a junction block in accordance with the invention; [0046] FIG. 8 is a front, elevation view of a junction block in accordance with the invention, with the absence of any electric receptacle blocks; [0047] FIG. 9 is a right-side elevation view of the junction block of FIG. 8 ; [0048] FIG. 10 is an underside view of the junction block shown in FIG. 8 ; [0049] FIG. 11 is an exploded, perspective view of a junction block in accordance with the invention, showing the bus bar configuration for the hot, neutral and ground connectors as they are to be inserted into the junction block; [0050] FIG. 12 is a further, exploded view of the junction block in accordance with the invention, showing the bus bars in place, and the end connectors and front cover being in position so as to be connected to the base housing of the junction block; [0051] FIG. 13 is a front, perspective view of the fully assembled junction block; [0052] FIG. 14 is a rear, perspective view of the junction block shown in FIG. 13 ; [0053] FIG. 15 is a rear, elevation view of a first international receptacle which may be utilized in accordance with the invention; [0054] FIG. 16 is a plan view of the receptacle shown in FIG. 15 ; [0055] FIG. 17 is a left-side end view of the receptacle shown in FIG. 15 ; [0056] FIG. 18 is a front, elevation view of the receptacle shown in FIG. 15 ; [0057] FIG. 19 is a right-side end view of the receptacle shown in FIG. 15 ; [0058] FIG. 20 is an underside view of the receptacle shown in FIG. 15 ; [0059] FIG. 21 is a rear, elevation view of a second outlet receptacle in accordance with the invention, with the receptacle having a three-pronged configuration; [0060] FIG. 22 is a plan view of the receptacle as shown in FIG. 21 ; [0061] FIG. 23 is a left-side end view of the receptacle as shown in FIG. 21 ; [0062] FIG. 24 is a front, elevation view of the receptacle as shown in FIG. 21 , and illustrating the three terminals for receipt of three prongs of an electrical plug; [0063] FIG. 25 is a right-side end view of the receptacle as shown in FIG. 21 ; [0064] FIG. 26 is an underside view of the receptacle as shown in FIG. 21 ; [0065] FIG. 27 is a rear, elevation view of a third embodiment of a receptacle in accordance with the invention, with the receptacle having three sockets for receiving circular prongs of a plug; [0066] FIG. 28 is a plan view of the receptacle as shown in FIG. 27 ; [0067] FIG. 29 is a left-side end view of the receptacle shown in FIG. 27 ; [0068] FIG. 30 is a front, elevation view of the receptacle as shown in FIG. 27 , and showing the three circular sockets for receipt of circular plug prongs; [0069] FIG. 31 is a right-side end view of the receptacle as shown in FIG. 27 ; [0070] FIG. 32 is an underside view of the receptacle as shown in FIG. 27 ; [0071] FIG. 33 is a rear, elevation view of a fourth embodiment of a receptacle in accordance with the invention, with the receptacles having three sockets, with one of the sockets having a T-shaped configuration; [0072] FIG. 34 is a plan view of the receptacle as shown in FIG. 33 ; [0073] FIG. 35 is a left-side end view of the receptacle as shown in FIG. 33 ; [0074] FIG. 36 is a front, elevation view of the receptacle as shown in FIG. 33 ; [0075] FIG. 37 is a right-side end view of the receptacle as shown in FIG. 33 ; [0076] FIG. 38 is an underside view of the receptacle as shown in FIG. 33 ; [0077] FIG. 39 is a rear, elevation view of a fifth embodiment of a receptacle in accordance with the invention; [0078] FIG. 40 is a plan view of the receptacle as shown in FIG. 39 ; [0079] FIG. 41 is a left-side end view of the receptacle as shown in FIG. 39 ; [0080] FIG. 42 is a front, elevation view of the receptacle as shown in FIG. 39 , and showing a set of three sockets having a polarized configuration; [0081] FIG. 43 is a right-side end view of the receptacle as shown in FIG. 39 ; [0082] FIG. 44 is an underside view of the receptacle as shown in FIG. 39 ; [0083] FIG. 45 is a rear, elevation view of a sixth embodiment of a receptacle in accordance with the invention; [0084] FIG. 46 is a plan view of the receptacle as shown in FIG. 45 ; [0085] FIG. 47 is a left-side end view of the receptacle as shown in FIG. 45 ; [0086] FIG. 48 is a front, elevation view of the receptacle as shown in FIG. 45 , and showing the receptacle as having a three socket configuration; [0087] FIG. 49 is a right-side end view of the receptacle as shown in FIG. 45 ; [0088] FIG. 50 is an underside view of the receptacle as shown in FIG. 45 ; [0089] FIG. 51 is an exploded view of the second embodiment of a receptacle in accordance with the invention, as illustrated in FIGS. 21-26 , with FIG. 51 showing the receptacle cover and the base outlet housing, and showing the clip terminals prior to interconnection; [0090] FIG. 51A is similar to FIG. 51 , but shows the terminal connector clips in a connected configuration; [0091] FIG. 51B is an enlarged view of the area identified by circle 51 B in FIG. 51 ; [0092] FIG. 51C is an enlarged view of the area identified by circle 51 C in FIG. 51A ; [0093] FIG. 52 is a side, sectional view of the receptacle as shown in FIG. 51 , and showing the receptacle cover plate prior to interconnection with the receptacle base housing; [0094] FIG. 53 is an enlarged view of the area identified by circle 53 in FIG. 52 ; [0095] FIG. 54 is a sectional view similar to FIG. 52 , but showing the cover plate as it is releasably secured to the receptacle base housing; [0096] FIG. 55 is an enlarged view of the area identified by circle 55 in FIG. 54 ; [0097] FIG. 56 is a perspective view of the assembled receptacle originally shown in FIGS. 21-16 ; [0098] FIG. 57 is an underside, perspective view of the receptacle as shown in FIG. 56 ; [0099] FIG. 58 is a perspective view of an assembled receptacle as previously shown in FIGS. 39-44 ; [0100] FIG. 59 is an underside, perspective view of the receptacle as shown in FIG. 58 ; [0101] FIG. 60 is a perspective view of an assembled receptacle corresponding to the receptacle previously illustrated in FIGS. 33-37 ; [0102] FIG. 61 is an underside, perspective view of the receptacle as shown in FIG. 60 ; [0103] FIG. 62 is a perspective view of the assembled receptacle as previously shown in FIGS. 45-49 ; [0104] FIG. 63 is an underside perspective view of the receptacle as shown in FIG. 62 ; [0105] FIG. 64 is a perspective view of the fully assembled receptacle as previously illustrated in FIGS. 27-32 ; [0106] FIG. 65 is an exploded view of the receptacle as shown in FIG. 64 , showing the receptacle cover plate as it is being assembled to the receptacle base housing; [0107] FIG. 66 is an underside, perspective view of the receptacle as shown in FIG. 64 ; [0108] FIG. 67 is a perspective and exploded view of the receptacle previously illustrated in FIGS. 15-20 , and illustrating the receptacle cover plate as it is being assembled with the receptacle base housing; [0109] FIG. 68 is a perspective view of the receptacle as shown in FIG. 67 , but shown in a fully assembled state; [0110] FIG. 69 is an underside, perspective view of the receptacle as shown in FIG. 68 ; [0111] FIG. 70 is an exploded view showing the second receptacle previously illustrated in FIGS. 21-26 as it is being inserted into a junction block; [0112] FIG. 70A is a perspective view similar to FIG. 70 , but showing the second receptacle and the junction block in an assembled state; [0113] FIG. 70B is an enlarged view of the portion of FIG. 70A identified by circle 70 B; [0114] FIG. 71 is an exploded view of the first receptacle previously illustrated in FIGS. 15-20 as it is being inserted into a junction block; [0115] FIG. 72 is a perspective view similar to FIG. 72 , but showing the first receptacle in a fully assembled state with the junction block. [0116] FIG. 73 is a perspective view of a junction block showing its use with the first receptacle as shown in FIGS. 15-20 and the third receptacle as shown in FIGS. 27-32 ; [0117] FIG. 74 is a perspective view similar to FIG. 73 , but showing the junction block is use with the third receptacle as shown in FIGS. 27-32 and the second receptacle as shown in FIGS. 21-26 ; [0118] FIG. 75 is a perspective view similar to FIG. 74 , but showing the junction block in use with the second receptacle as shown in FIGS. 21-26 and the first receptacle as shown in FIGS. 15-20 ; [0119] FIG. 76 is a perspective view of another embodiment of a junction block in accordance with the invention, showing the capability of receiving three receptacles, and specifically showing use with the second receptacle ( FIGS. 21-26 ), first receptacle ( FIGS. 15-20 ) and third receptacle ( FIGS. 27-32 ); [0120] FIG. 77 is a perspective view of a further embodiment of a junction block in accordance with the invention, showing the junction block as being adapted to receive four receptacles, and expressly showing its use with two of the third receptacles ( FIGS. 27-32 ) and two of the first receptacles ( FIGS. 15-20 ); [0121] FIG. 78 illustrates a rear, perspective view of a junction block in accordance with the invention, and further showing it in an exploded view with connecting screws positioned so as to connect a rear plate to the junction block; [0122] FIG. 79 shows the junction block of FIG. 78 in a fully assembled position; [0123] FIG. 80 is a rear, elevation view of a cable connector in accordance with the invention; [0124] FIG. 81 is a plan view of the cable connector shown in FIG. 80 ; [0125] FIG. 82 is a left-side end view of the cable connector shown in FIG. 80 ; [0126] FIG. 83 is a front, elevation view of the cable connector shown in FIG. 80 ; [0127] FIG. 84 is a right-side end view of the cable connector shown in FIG. 80 ; [0128] FIG. 85 is an underside view of the cable connector shown in FIG. 80 ; [0129] FIG. 86 is an exploded view of the cable connector shown in FIG. 80-85 , and showing the position of the cable and blade terminals as they are received within the housing of the cable connector; [0130] FIG. 87 is a view similar to FIG. 86 , but shows the cable and terminal blades connected to the housing of the cable connector; [0131] FIG. 88 is a perspective, exploded view of the cable connector shown in FIGS. 80-85 , and expressly showing the position of the screws or pop rivets as are utilized to assemble together the sides of the cable connector housing; [0132] FIG. 89 is a right-side perspective view of the fully assembled cable connector as shown in FIG. 88 ; [0133] FIG. 90 is an underside, perspective view of the cable connector as shown in FIG. 89 ; [0134] FIG. 91 is a rear, perspective view of a female cable connector in accordance with the invention; [0135] FIG. 92 is a plan view of the cable connector as shown in FIG. 91 ; [0136] FIG. 93 is a left-side end view of the cable connector as shown in FIG. 91 ; [0137] FIG. 94 is a front, elevation view of the female cable connector as shown in FIG. 91 ; [0138] FIG. 95 is a right-side end view of the female cable connector as shown in FIG. 91 ; [0139] FIG. 96 is an underside view in section of the cable connector as shown in FIG. 91 ; [0140] FIG. 97 is a perspective and exploded view of the female cable connector as shown in FIG. 91 , and showing the cable and female terminal blades as they are received within the housing of the cable connector; [0141] FIG. 98 shows the cable and female terminals as they are received within the cable connector housing; [0142] FIG. 99 is a perspective view of the female cable connector as shown in FIG. 91 , and showing the two halves of the housing being connected together through screws or pop rivets; [0143] FIG. 100 is a front, perspective view of the fully assembled female cable connector as shown in FIG. 99 ; [0144] FIG. 101 is an underside, perspective view of the female cable connector as shown in FIG. 100 ; [0145] FIG. 102 is a perspective view of a full connector cable with male and female ends in accordance with the invention; [0146] FIG. 103 is a perspective view similar to FIG. 102 , but in an opposing configuration, showing the connector cable in accordance with the invention; [0147] FIG. 104 is a perspective view of a junction block in accordance with the invention, having two receptacles and showing the junction block in an exploded format with cable connector ends positioned so as to be received by junction block end connectors; [0148] FIG. 105 is an exploded view of the portion of FIG. 104 identified within circle 105 ; [0149] FIG. 106 is a perspective view similar to FIG. 104 , but showing the junction block in a fully assembled position with respect to the connector cable ends; [0150] FIG. 107 is an exploded view of the portion of FIG. 106 identified by circle 107 ; [0151] FIG. 108 is an enlarged view showing the positioning of a junction block connector as it is about to receive a cable connector end; [0152] FIG. 109 is a view similar to FIG. 108 , but showing the junction block connector and the connector cable end in a fully assembled position; [0153] FIG. 110 is a perspective view similar to FIG. 109 ; [0154] FIG. 111 is a perspective view similar to FIG. 108 ; [0155] FIG. 112 is a sectional view showing an exploded view of a male cable connector end being received by a female cable connector end of another connector cable; [0156] FIG. 113 is an exploded view of a portion of FIG. 112 , identified by the circle 113 ; [0157] FIG. 114 is a sectional view similar to FIG. 112 , but showing the cable connector ends in a fully assembled position; [0158] FIG. 115 is an exploded view of the portion of FIG. 114 identified by circle 115 ; [0159] FIG. 116 is a sectional view similar to FIG. 112 ; [0160] FIG. 117 is an enlarged view showing the portion of FIG. 116 identified by circle 117 ; [0161] FIG. 118 is a sectional view similar to FIG. 116 , but showing the cable connector ends as being partially assembled together; [0162] FIG. 119 is an enlarged view of the portion of FIG. 118 identified by circle 119 ; [0163] FIG. 120 is a sectional view similar to FIG. 118 , but showing the cable connector ends in a fully assembled position; [0164] FIG. 121 is an enlarged view of a portion of FIG. 120 identified by circle 121 ; [0165] FIG. 122 is a rear, elevation view of a power entry connector in accordance with the invention; [0166] FIG. 123 is a plan view of the power entry connector as shown in FIG. 122 ; [0167] FIG. 124 is a left-side elevation view of the power entry connector as shown in FIG. 122 ; [0168] FIG. 125 is a front, elevation view of the power connector as shown in FIG. 122 ; [0169] FIG. 126 is a right-side elevation view of the power connector as shown in FIG. 122 ; [0170] FIG. 127 is an underside view of the power connector as shown in FIG. 122 ; [0171] FIG. 128 is an exploded view showing various elements of the power connector as shown in FIG. 122 ; [0172] FIG. 129 is a further, exploded view of the power connector as shown in FIG. 122 , and showing the relative positioning of fuses; [0173] FIG. 130 is a further, exploded view of the power connector as shown in FIG. 122 , and showing the positioning of the fuse cover for assembly; [0174] FIG. 131 is a perspective view of the power connector as shown in FIG. 122 , and showing the power entry wires in position to be received by the connectors of the power connector 122 ; [0175] FIG. 132 is a perspective view showing the incoming power wires as assembled to the power connector 122 ; [0176] FIG. 133 is an exploded view of the portion of FIG. 132 identified by circle 133 ; [0177] FIG. 134 is a perspective view of the fully assembled power entry connector as shown in FIG. 122 ; [0178] FIG. 135 is a perspective and exploded view of the power entry connector as shown in FIG. 122 , as a pair of connector cable ends are positioned so as to be received by the power entry connector; [0179] FIG. 136 is a perspective view similar to FIG. 135 , and showing one of the connector cable ends being received by the power entry connector; [0180] FIG. 137 is a perspective view similar to FIG. 135 , and showing the cable connector ends in a fully assembled position with the power entry connector; [0181] FIG. 138 is a rear, elevation view of a connector terminal assembly in accordance with the invention; [0182] FIG. 139 is a plan view of the connector terminal assembly as shown in FIG. 138 ; [0183] FIG. 140 is a left-side end view of the connector terminal as shown in FIG. 138 ; [0184] FIG. 141 is a front, elevation view of the connector terminal as shown in FIG. 138 ; [0185] FIG. 142 is a perspective view of the connector terminal as shown in FIG. 138 ; [0186] FIG. 143 is an underside view of the connector terminal as shown in FIG. 138 ; [0187] FIG. 144 is a rear, elevation view of a single connector terminal unit which may be used with the connector terminal assembly as shown in FIG. 138 ; [0188] FIG. 145 is a plan view of the connector terminal unit as shown in FIG. 144 ; [0189] FIG. 146 is a left-side end view of the connector terminal unit; [0190] FIG. 147 is a front, elevation view of the connector terminal unit; [0191] FIG. 148 is a right-side end view of the connector terminal unit; [0192] FIG. 149 is an underside view of the connector terminal unit; [0193] FIG. 150 is an exploded view showing a set of three connector terminal units as they would be initially positioned for assembly into the connector terminal assembly as shown in FIG. 138 ; [0194] FIG. 151 is a further, exploded view similar to FIG. 150 , and further showing the positioning of the connector terminal units for assembly with the connector terminal assembly; [0195] FIG. 152 is a perspective view of the connector terminal assembly as shown in FIG. 138 , in a fully assembled position; [0196] FIG. 153 is a further, perspective view of the connector terminal assembly as shown in FIG. 152 , but showing the terminal assembly in an opposing direction; [0197] FIG. 154 is an exploded view of a junction block with may be utilized in accordance with the invention, and further showing a cover plate which may be assembled with the junction block; [0198] FIG. 155 is a perspective view similar to FIG. 154 , but showing the cover plate assembled to the junction block, and showing side connectors which may be utilized for securing receptacles within the junction block and cover plate; [0199] FIG. 156 is a front, elevation view of the junction block and cover plate as shown in FIG. 155 ; [0200] FIG. 157 is a sectional view, taken along section lines 157 - 157 of FIG. 156 ; [0201] FIG. 158 is a perspective view of the cover plate and junction block, and side connectors in a fully assembled position; [0202] FIG. 159 is an exploded view of the portion of FIG. 158 identified by circle 159 ; [0203] FIG. 160 is a perspective, exploded view showing how a junction block and receptacles in accordance with the invention can be mounted to a side board through the use of connecting screws and the like; [0204] FIG. 161 is a perspective and exploded view similar to FIG. 160 , but showing the junction block with a cover plate and receptacles, and its positioning so as to be mounted within a rectangular slot within a face board or the like; [0205] FIG. 162 is a side view rotated 90 degrees of a junction block and cover plate in accordance with the invention, and showing the position thereof with a relatively thin face board having a dimension X; [0206] FIG. 163 is a side view similar to FIG. 162 , but showing the junction block and cover plate in use with a face board having a relatively thicker dimension Y; and [0207] FIG. 164 is a side view similar to FIGS. 162 and 163 , but showing use of the junction block cover plate with a face board of a still greater thickness Z. DETAILED DESCRIPTION OF THE INVENTION [0208] The principles of the invention are disclosed, by way of example, within international outlet systems which provide for various configurations of outlet receptacles. The international outlet systems in accordance with certain aspects of the invention utilize junction blocks and cable connectors, where various power and communication outlets can be selectively and electrically interconnected to the junction blocks. In this manner, a common junction block can be utilized for a variety of international outlets. These inventive principles will be described with respect to systems illustrated in FIGS. 1-164 . [0209] To provide for one example background of where international outlet systems in accordance with the invention may be utilized, FIG. 1 illustrates a work surface international outlet system 100 . As shown in FIG. 1 , the work surface international outlet system 100 is being used with a pair of work surfaces 102 . Positioned below the upper surface of each of the work surfaces 102 is a raceway 104 . Each of the raceways 104 can be positioned and include appropriate components so as to support various elements of the international outlet system 100 . [0210] With respect to the outlet system 100 itself, it includes an incoming power entry connector 106 which can be connected to a source of incoming external power (not shown). Connected to the power entry connector 106 are a pair of power entry cables 108 . The cables 108 are connected through power entry cable connectors 110 . The opposing ends of the power entry cables 108 are connected to opposing power entry cable connectors 112 . Each of the opposing power entry cable connectors 112 is electrically and releasably, physically connected to a junction block 114 . This connection occurs at one end of the junction blocks 114 . Connector cable assemblies 116 are connected at one end to the opposing end of each of the junction blocks 114 . The opposing end of the connector cable assemblies 116 is electrically connected to a further set of junction blocks 114 . This electrical interconnection can continue through a significant number of connector cable assemblies 116 at junction blocks 114 so as to provide for a distribution assembly for both power systems and communication systems. [0211] Each of the connector cable assemblies 116 include end connectors 118 . The end connector 118 include a first end connector 120 , and a second end connector 122 . Interconnecting together the first and second end connectors 120 , 122 is a cable 124 . It should be noted that if desired, and in accordance with certain embodiments of international outlet systems in accordance with the invention, one of the end connectors 118 can be a female end connector, while the opposing end connector 118 can be a male end connector. In this regard, it is also noted that each of the junction blocks 114 include a pair of end connectors 126 . The junction block end connectors 126 can include a first junction block end connector 128 , and a second and opposing junction block end connector 130 . As will be apparent from subsequent description herein, it is advantageous for one of the junction block end connectors 126 to be a female end connector, while the opposing junction block end connector 126 is a male end connector. [0212] As is also particularly shown in FIG. 2 , the junction blocks 114 can be utilized to selectively receive receptacle blocks 132 . With the junction block 114 as shown in FIG. 2 , a pair of outlet receptacle blocks 132 are shown as comprising a first outlet receptacle block 134 having a first particular outlet configuration, and a second electrical outlet receptacle block 136 , having a differing electrical outlet configuration. [0213] A further international outlet system in accordance with the invention is described herein as wall panel outlet system 140 as illustrated in FIGS. 3 and 4 . The wall panel international outlet system 140 is adapted for use with furniture such as the wall panels 142 and 144 illustrated in FIG. 3 . Although not shown in FIGS. 3 and 4 , the various components of the wall panel outlet system 140 can be received within raceways or the like (not shown) associated with the interiors of the wall panels 142 , 144 . In the particular configuration shown in FIGS. 3 and 4 , the system 140 includes an incoming power entry connector 106 , with a single power entry cable 108 . The power entry cable 108 includes a power entry cable connector 110 and an opposing power entry cable connector 112 . As further shown in FIG. 3 , the system 140 includes a set of five junction blocks 114 . Also included are a set of four connector cable assemblies 116 , with the connector cable assemblies 116 being capable of being of differing lengths. In addition, the power entry cable 108 can also be configured in a manner substantially identical to any of the connector cable assemblies 116 . One element which is illustrated in FIG. 3 , but was not shown in FIG. 1 or 2 is the connector terminal assembly 146 . As shown in FIG. 3 , and in an enlarged view in FIG. 4 , the connector terminal assembly 146 provides for the capability of receiving two connector cable end connectors, and connecting both to a junction block end connector 126 . Again, this is particularly shown in FIG. 4 . [0214] It will be apparent to those skilled in the pertinent arts that still other embodiments of electrical assemblies in accordance with the invention can be designed. That is the principles of an electrical assembly in accordance with the invention are not limited to the specific embodiments described herein. Accordingly, it will be apparent to those skilled in the art that modifications and other variations of the above-described illustrative embodiments of the invention may be effected without departing from the spirit and scope of the novel concepts of the invention.

A mechanical outlet system is connected to an incoming power source through power entry cables. The cables connect to cable connectors which, in turn, connect to junction blocks. The junction blocks receive outlet receptacle blocks. The receptacle blocks can be of varying types of sockets, without requiring electrical modifications to the junction blocks.

CROSS-REFERENCE TO THE RELATED APPLICATION [0001] This application claims priority to U.S. Provisional Application Ser. No. 62/366,150, filed on Jul. 25, 2016, the contents of which are hereby incorporated by reference in its entirety. FIELD OF INVENTION [0002] The field of invention relates to venue control and in particular relates to access controls to manage the entrances and exits of venues for temporary events such as festivals and fairs. BACKGROUND [0003] Festivals and fairs especially busy ones tend to have long line ups at entrances and exits as it takes time to process visitors and to validate their tickets or other entrance credentials. Thus visitors are required to wait, rain or shine, and waste valuable time that could have been spent actually enjoying the event. [0004] The festival industry is booming and is providing a fertile ground for vendors to showcase and offer sampling opportunities to their customer base. Such temporary events are proving to be attractive marketing campaigns for vendors looking to increase their customer base and introduce new consumers to their products by offering an opportunity to sample various items. [0005] A festival is an event ordinarily staged by a community, centering on and celebrating some unique aspect of that community and its traditions, often marked as a local or national holiday. Festivals often serve to meet specific purposes, especially in regard to commemoration and/or celebration. A festival provides an opportunity for people to come together and celebrate while also partaking in entertainment. [0006] A food festival is an event celebrating food or drink. A food festival usually highlights the output of producers from a certain region. Some food festivals are focused on a particular type of food item. There are also specific beverage festivals, such as the famous [0007] Oktoberfest in Germany for beer. Many cities hold festivals to celebrate wine or other produce from local producers. [0008] A fair is a gathering of people to display or trade produce or other goods, to parade or display animals and often to enjoy associated entertainment like a circus or midway attractions. Festivals and fairs are normally temporary in nature; some last only an afternoon while others may last a few days. [0009] Since the nature of festivals and fairs is temporary and the vendors participating in these events are generally small local vendors who have limited to no technology at their disposal; consumer information gathering at such events is not possible. [0010] Radio-frequency identification (RFID) is the wireless non-contact use of radio-frequency electromagnetic fields to transfer data for the purposes of automatically identifying and tracking tags attached to objects. The tags contain electronically stored information. Some RFID tags are powered by and read at short ranges (a few centimeters) via electromagnetic induction. Other types of RFID tags may use a local power source such as a battery, or else have no battery but collect energy from the interrogating electromagnetic field, and then act as a passive transponder to emit microwaves or UHF (ultra high frequency) radio waves. Unlike a bar code, the RFID tag does not necessarily need to be within line of sight of the reader, and may be embedded in an object. [0011] RFID tags can be passive or active or battery-assisted passive. A passive tag is cheaper and smaller because it has no battery. An active tag has an on-board battery and periodically transmits its ID signal. A battery-assisted passive (BAP) tag has a small battery on board and is activated when in the presence of an RFID reader. [0012] RFID tags may either be read-only, having a factory-assigned serial number that is used as a key into a database, or may be read/write, where object-specific data can be written into the RFID tag by the system. Field programmable RFID tags may be write-once, read-multiple; “blank” RFID tags may be written with an electronic product code by the user. [0013] Generally fixed RFID readers are set up to create a specific interrogation zone which can be tightly controlled. This allows a highly defined reading area for when tags go in and out of the interrogation zone. Mobile RFID readers may be hand-held or mounted on carts or vehicles. But all of the aforementioned prior art methods are manual and require a work force to scan the RFID tags. [0014] Despite advances in technology, prior art methods still have several shortcomings e.g. a lack of information gathering about consumer sampling at a festival or fair. Since the duration of a festival or fair is so brief, conventional methods for setting up and collecting consumer behaviour information are not suitable or may cost too much to provide a meaningful business benefit. Thus consumer information is neither collected nor compiled in real time to be useful due to the brevity of the event. Thus a wholesale change is needed in the way brands and/or vendors and/or manufacturers (distributors, event organizers, exhibitors, etc.) engage with their audience from basic entry all the way to post event communication and data mining. [0015] To compound this problem, consumers have steadily been moving away from cash based transactions as they don't want the hassle of carrying cash and coins, which can also be easily lost or stolen in the rush of a festival. One method to overcome this limitation is to use touchless and cashless transaction methods that provide convenience and save time. [0016] One method of achieving touchless and cashless transactions is through credit cards. Wristbands have also arisen that are embedded with RFID (Radio-frequency identification) tags and can be used as a touchless payment fob. RFID tags allow for a “tap and go” style of payment because the information is transmitted wirelessly. Two-way radio transmitter-receivers called readers send a signal to the tag and read its response. In such a transaction the user is not required to sign a piece of paper or to enter the PIN number, and neither there is any verification of signature. [0017] Prior art methods, such as paper tickets, used at fairs, festivals, and similar events to process visitors are manual and slow. Token systems using physical items to act as a medium for exchange for goods at the event have been used but require the exchange of real currency for another physical item that must be carried around. These do not improve the guests' experience and often hinder that experience by now requiring plastic tokens or another medium to be cared for. Further, such tokens do not allow for an automated way to capture the transaction data from the event. Tokens must be exchanged in a similar way as hard currency and thus are equally slow and “dumb”. [0018] Such methods are outdated and take away from the pleasure of attending events that are brief in nature. SUMMARY [0019] The present invention broadly relates to a system and method of venue control using near field communications (NFC and RFID) Portals to manage the entrances and exits of temporary venues where visitors have been issued temporary RFID tags for admittance. The system and method also contemplates the use of these RFID Portals for gathering visitor behaviour information. The present invention provides a system and method of electronic touchless visitor processing for events that are temporary, short term and transient in nature (for example a wine and cheese festival held over a long weekend). Other embodiments may be adapted for permanent locations. [0020] According to a first aspect of the invention, an RFID portal is provided for placing at an access point associated with a temporary event. The access point is controlled by a security control. The portal has a portal body erectable on at least one side of a user pathway at the access point; and an RFID reader in the portal body for reading an RFID tag issued to, and worn by, an individual user for the event that has an encoded unique UserID readable by the RFID reader. The RFID reader is located in the portal body, so as to be physically proximate to a location of the user's body where the RFID tag is worn. The RFID reader is in communication with a server which has stored a list of valid UserIDs for the event. The RFID portal also has an indicator system for receiving notification from the server that the read UserID is a valid UserID for the event and generating an indication to the security control, such that the security control permits the user to proceed along the pathway. [0021] For example, where the RFID tag is in a bracelet or wristband format, the RFID reader may be positioned proximate to natural wrist height of the user walking by. Or, where the RFID tag is in an anklet or shoe-mounted format, the RFID reader may be positioned proximate to the user's foot or ankle height. It is a goal of the invention to make the admission process as low-impact as possible. The process of verification of the user's “ticket” is done entirely through the RFID tag issued to the user. The user does not need to stand in place and present this to a security guard or event personnel for scanning with a scan gun, but the user simply walks very naturally through the portal area with the tag being scanned on the fly. [0022] In some embodiments the security control may be a security guard. In this case, the indicator system may include a light that visibly displays the indication to the security guard (e.g. green for go; red for stop). Alternatively, or in addition, the indicator system may include an emitter that audibly provides the indication to the security guard. In some embodiments, the security control is an automatically released barrier, gate, arm or turnstile, which is released with the indication. [0023] Preferably, the RFID reader is capable of reading an ICODE SLI2 16693 tag or an ICODE SLI2 15693 tag. [0024] The RFID portal may further include a portal head mounted on the portal body, which has: a first screen mounted generally away from the user; and a second screen mounted generally toward the user. The UserID may be associated with other data stored on the server. At least some of this other data may be retrieved and displayed on the first and/or second screen when the RFID tag is read. One or more messages related to the other data may also be displayed on the first and/or second screen when the RFID tag is read. For example, the other data may include: an age or date of birth credential, an access or privilege credential, and a stored funds balance. [0025] For example, the first screen may display an access permitted decision, while the second screen displays a welcome message. The welcome message may be personalized to the user (e.g. indicating the user's name, or an id number, or particulars of the user's account, such as VIP status, or buying credits or account balance). [0026] In some embodiments, the RFID portal may be gangable with other RFID portals at the access point, such that the user passes between two adjacent RFID portals. [0027] The access point may be an entry point to the event, or may for example, be an entry point to a subzone within the event. [0028] Preferably, the RFID reader is further programmed for sending a timestamp of the user's entry to the server. [0029] The RFID portal may also optionally include an RFID writer for writing data or updated data to the RFID tag (e.g. adding or changing a funds balance associated with the RFID tag, or cancelling a single-use entry credential, so that the user cannot re-enter the event). [0030] According to a second aspect of the invention, a self-contained RFID portal is provided for placing at an access point associated with a temporary event. The access point is controlled by a security control. The portal has a portal body erectable on at least one side of a user pathway at the access point; and an RFID reader in the portal body for reading an RFID tag issued to, and worn by, an individual user for the event that has an encoded unique UserID readable by the RFID reader. The RFID reader is located in the portal body, so as to be physically proximate to a location of the user's body where the RFID tag is worn. A processor and storage is contained within the portal body. The storage includes a locally-stored list of valid UserIDs for the event. The processor is programmed for comparing the read UserID to the list of valid UserIDs for the event. An indicator system indicates a match from the comparing step to the security control, such that the security control permits the user to proceed along the pathway. [0031] In one embodiment each visitor is given an RFID tag that may be embedded in a wearable item e.g. a wristband or a necklace at the start of the event. Each RFID tag has a unique UserID. In one embodiment each RFID tag has a unique UserID. Optionally the RFID tag may allow funds to be preloaded to it for later use at the venue. A visitor may also be able to add a balance in advance to attending the event e.g. at the time of registration a consumer may opt to add $100 that can then be used via the RFID tag to sample or purchase different products being show cased at the event. Thus when the visitor arrives at the fair or festival and is given the RFID wristband it includes a privilege to spend $100 at the different sales booths setup at the venue. [0032] A connected server stores the unique UserIDs of RFID tags for consumers. The connected server is preferably accessible over a network e.g. a LAN or a WAN or over the internet. [0033] The venue is equipped with one or more RFID Portals, such as at the entrance and exit of the venue. Each RFID Portal has an RFID reader embedded in it. Signaling between the RFID reader and the RFID tag can be done in several different ways, depending on the frequency band used by the RFID tag. [0034] The one or more RFID Portals are in communication with a connected server that stores the UserIDs of the RFID tags. The connected server may also optionally store any associated balances, age information, zone restriction/privileges information etc. The connected server is accessible over a network for example a local area network (LAN). [0035] The RFID Portal may have two main sections the RFID Portal Head and the RFID Portal Body. The RFID Portal Head preferably has two display screens embedded at the opposite ends, e.g. LCD screens. Of the two display screens, the first screen Screen 1 is used for displaying information to the visitor and the second screen Screen 2 is used for displaying the information to the security personnel. [0036] The RFID reader embedded in the Portal Body is used for reading the RFID tags worn by the visitors for controlling the access to the venue. [0037] The RFID Portal may also incorporate one or more indicator LED lights e.g. LED lights that are used for communicating certain status information with the visitors and the security personnel. The RFID Portal in addition may also use other sensory methods e.g. auditory beeps may also be used for conveying some or part of the information to the security personnel. [0038] The RFID Portal can be self-contained with the RFID reader, electronics for communicating with the connected server and the Portal Head with the two display screens. [0039] Through the RFID technology festival goers are able to engage with the vendors during and after the event. The RFID Portals provide a convenient and fast visitor processing system enabling visitors to spend more time enjoying the festivities and less time waiting in lines. [0040] The venue of a fair or a festival may be set up with one or more RFID Portals that embed RFID readers, a connected server that stores the UserIDs of the RFID tags, associated balances, age information, zone restriction/privileges information. The server is preferably accessible by the RFID Portals over a network for example a local area network (LAN). [0041] Preferably, the RFID tags are embedded in some kind of a wearable format, e.g. a wristband, an ankle-band, a shoe-mounted format, a pair of sunglasses, a necklace, a badge, etc. Each RFID tag has a unique UserID associated with it. [0042] Preferably, the system also allows for the collection and compilation of data using the RFID Portals. The information is gathered in real time to be useful via the RFID tags worn by visitors either in a wristband or other RFID wearable item. This entrance/exit data may also be combined with other user data collected through the RFID tags (e.g. through other transactional or sampling readers located throughout the venue), or through data provided by the user before or after the event. [0043] Unique IDs may also be issued to each of the vendors (VendorID) participating in the event, while also providing ProductIDs for each of the products that the vendor may be offering for sampling at the event. [0044] Real time information can then be gathered using RFID Portals, at an event level or subzone (e.g. booth). Each time a consumer enters a booth, samples or purchases one or more products and then leaves the booth, information may be gathered as to when consumer entered a booth, what products were sampled or purchased in what order they were sampled or purchased, and when the consumer left the booth. [0045] For example when the consumer visits a booth e.g. a wine tasting tooth of a winery at a wine and cheese festival that is being held over a weekend the RFID wristband UserID may be captured and saved to the server; while VendorID is saved to the RFID wristband of the consumer. The ProductIDs of the products sampled and purchased by the said consumer at this booth are also captured and saved to the RFID wristband and the server. When the consumer leaves the wine tasting booth RFID wristband UserID is captured and saved to the server; while VendorID is saved to the RFID wristband of the consumer. [0046] Similarly when the said consumer visits a second and a third booth the RFID UserID and timestamps are captured at arrival and departure of the consumer to these booths; and the ProductIDs of the products sampled and purchased at the second and third booth are also captured and saved to the RFID wristband and the server. [0047] The ProductIDs may be saved to the server or the RFID wristband of the consumer. In an alternate embodiment the ProductIDs and the VendorID are saved both to the server and the RFID wristband of the consumer. [0048] In one embodiment gathered information may be compiled about consumer's visits to different booths during an event and about the products purchased or sampled at each of the booths visited by the consumer. This information may be shared with a vendor (e.g. how many consumers visited the vendor's booth and what products were purchased and sampled). Similarly information may be shared with individual consumers about their visit to different booths and which products were purchased and sampled during the visit. BRIEF DESCRIPTION OF THE FIGURES [0049] FIG. 1 is a flow diagram of a basic flow for an RFID portal enabled event. [0050] FIG. 2 is a first side (user-facing) view of an RFID portal. [0051] FIG. 3 is a second side (security-facing) view of an RFID portal. [0052] FIG. 4 is a flow diagram of a sample processing flow for RFID portal. [0053] FIG. 5 is a flow diagram of credential verification (here, in an age restricted zone). [0054] FIG. 6 is a flow diagram of data compilation using a system of RFID portals. DETAILED DESCRIPTION [0055] Before embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of the examples set forth in the following descriptions or illustrated drawings. The invention is capable of other embodiments and of being practiced or carried out for a variety of applications and in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. [0056] Before embodiments of the software modules or flow charts are described in detail, it should be noted that the invention is not limited to any particular software language described or implied in the figures and that a variety of alternative software languages may be used for implementation of the invention. [0057] It should also be understood that many components and items are illustrated and described as if they were hardware elements, as is common practice within the art. However, one of ordinary skill in the art, and based on a reading of this detailed description, would understand that, in at least one embodiment, the components comprised in the method and tool are actually implemented in software. [0058] As will be appreciated by one skilled in the art, the present invention may be embodied as a system, method or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product embodied in any tangible medium of expression having computer usable program code embodied in the medium. In order to provide a context for the various aspects of the disclosed invention, as well as the following discussion are intended to provide a brief, general description of a suitable environment in which the various aspects of the disclosed invention may be implemented. While the invention has been described in the general context of computer-executable instructions of a program that runs on one or more computers, those skilled in the art will recognize that the invention also may be implemented in combination with other program modules. Generally, program modules include routines, programs, components, data structures, etc. that perform particular tasks and/or implement particular abstract data types. Moreover, it will be appreciated that the present system and method may be practiced with other computer system configurations, including single-processor, multiprocessor or multi-core processor computer systems, mini-computing devices, mainframe computers, as well as personal computers, hand-held computing devices (e.g., personal digital assistant (PDA), phone, watch or other electronic gadgets incorporating the capacity to compute), microprocessor-based or programmable consumer or industrial electronics, and the like. The illustrated aspects may also be practiced in distributed computing environments where tasks/routines/processes etc. are performed by remote processing devices that are linked through a communications network e.g. a local area network (LAN) or the Internet. However, some, if not all aspects of the invention may be practiced on stand-alone computer(s). In a distributed computing environment, program modules may be located in both local and remote memory storage devices. [0059] Computer program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. Computer code may also be written in dynamic programming languages that describe a class of high-level programming languages that execute at runtime many common behaviours that other programming languages might perform during compilation. JavaScript, PHP, Perl, Python and Ruby are examples of dynamic languages. Additionally computer code may also be written using a web programming stack of software, which may mainly be comprised of open source software, usually containing an operating system, Web server, database server, and programming language. Some embodiments may use well-known open-source Web development platforms using Linux, Apache, MySQL and PHP. Other examples of environments and frameworks using which computer code may also be generated are Ruby on Rails which is based on the Ruby programming language, or node.js which is an event-driven server-side JavaScript environment. In the present case, the code is specialized to execute functions described herein which enable a smoother and more efficient technological process. [0060] Computing devices e.g. terminals or readers that enable a user to engage with the invention in general may include a memory for storing a control program and data, and a processor (CPU) for executing the control program and for managing the data, which includes user data resident in the memory and includes buffered content. The computing device may be coupled to a video display such as a television, monitor, or other type of visual display while other devices may have it incorporated in them (iPad, iPhone etc.). An application or an app or other simulation may be stored on a storage media such as a USB memory key, flash memory, or other type of memory media all collectively referred to as “removable media” in this disclosure. The app may also be downloaded from the internet. The removable media can be inserted to the console of a computing device where it is read. The console can then read program instructions stored on the removable media and present a user interface to the user. The user interface may preferably be a graphical user interface (GUI). [0061] FIG. 1 shows a preferred embodiment of the basic flow of the invention 100 . A system and method is provided using RFID Portals for venue control and automatic processing of visitor admittance 101 . [0062] The present invention relates to a system and method of electronic touchless visitor processing for events that are temporary, short term and transient in nature. With or without adaptation, the system may also be suitable for permanent venues. [0063] Some embodiments of related systems have been described in the applicant's copending U.S. patent application Ser. Nos. 14/717,234 (filed May 20, 2015); Ser. No. 14/946,287 (filed Nov. 19, 2015); and Ser. No. 15/048,551 (filed Feb. 19, 2016), the disclosures of which are incorporated herein by reference. [0064] One or more visitors may attend an event 102 , for example a wine and cheese festival held over a long weekend. [0065] Each visitor is given an RFID tag at the start of the event 103 . The RFID tag may be embedded in a wearable item e.g. a wristband, anklet or a necklace. [0066] Each RFID tag has a unique UserID 104 . Optionally the RFID tag may allow for funds to be loaded to it for later use at the venue. A visitor may also be able to add a balance in advance to attending the event e.g. at the time of registration a consumer may opt to add $100 that can then be used via the RFID tag to sample or purchase different products being showcased at the event. Thus when the visitor arrives at the fair or festival and is given the RFID wristband it includes a privilege to spend $100 at the different sales booths setup at the venue. [0067] A connected server stores the unique UserIDs of RFID tags for consumers 105 . The connected server is preferably accessible over a network e.g. a LAN or a WAN or over the internet. [0068] The venue is preferably equipped with one or more RFID Portals 106 , such as at the entrance and exit of a venue. Each RFID Portal has an RFID reader embedded in it. Signaling between the RFID reader and the RFID tag can be done in several different ways, depending on the frequency band used by the RFID tag. Optionally, the RFID Portal also includes a writer (not shown) that allows data to be written (or rewritten) to the tag. [0069] The one or more RFID Portals are in communication with a connected server that stores the UserIDs of the RFID tags. The connected server may also optionally store any associated balances, age information, zone restriction/privileges information etc. The connected server is accessible over a network for example a local area network (LAN). [0070] The unique UserIDs of RFID tags may be stored on the server in various formats and configurations. In the preferred embodiment the list of unique UserIDs of RFID tags may be available in a CSV (Comma Separated Values) format from the supplier. This CSV file is then uploaded to the server. The system then automatically initializes the RFID tags by creating a unique encryption method for that specific tag and writes the offline information to the memory of the RFID tag when the RFID tag is first read by an RFID reader in the system. In an alternative embodiment, the function of the server is replaced by a self-contained system in the RFID portal, which includes at least a processor and local storage containing the list of valid UserIDs. [0071] In one embodiment of the invention the system may use standardized RFID tags (ICODE SLI2 15693 on 13.56 MHz (HF)), the most common tag type for inventory tracking. [0072] RFID tags contain at least two parts: an integrated circuit for storing and processing information, modulating and demodulating a radio-frequency (RF) signal, collecting DC power from the incident reader signal, and other specialized functions; and an antenna for receiving and transmitting the signal. The tag information is stored in a non-volatile memory. [0073] The RFID tag includes either a chip-wired logic or a programmed or programmable data processor for processing the transmission and sensor data, respectively. [0074] Such RFID tags have a memory which has two sectors: the ROM (read only memory) and the R/W (read/write) memory. The ROM stores the UserID (also known as UID) of the RFID tag. This information is burnt to the ROM at the time of manufacturing and cannot be changed later. The second sector of the memory is a R/W memory, where transactional information is stored e.g. information such as balance, one or more previous transactions, zone restrictions, age limit, etc. Such information may be preferably stored in an encrypted format. The preceding list of items stored on the RFID tag is exemplary and the invention is not limited to these examples. [0075] An RFID reader transmits an encoded radio signal to interrogate the RFID tag. The RFID tag receives the message and then responds with its identification and other information. This may be only a unique tag serial number, or may include product-related information such as a stock number, lot or batch number, production date, or other specific information. In case of the double tap payment method, the balance is written to the RFID tag in addition to some other information like balance, age limit and zone restrictions etc. [0076] When written into the RFID tag by an RFID printer, the tag contains a 96-bit string of data. The first eight bits are a header which identifies the version of the protocol. The next 28 bits identify the organization that manages the data for this tag; the organization number is assigned by the EPCGlobal consortium. The next 24 bits are an object class, identifying the kind of product; the last 36 bits are a unique serial number for a particular tag. These last two fields are set by the organization that issued the RFID tag. Similar to a URL, the total electronic product code number can be used as a key into a global database to uniquely identify a particular product. [0077] Generally, the read range of an RFID tag is limited to the distance from the reader over which the tag can draw enough energy from the RFID reader field to power the tag. RFID tags may be read at longer ranges than they are designed for by increasing reader power. [0078] In one embodiment the use of RFID Portals prevents visitors from fraudulently entering any areas that are restricted. [0079] FIG. 2 shows a preferred embodiment of the RFID Portal 200 . The RFID Portal has two main sections the RFID Portal Head 201 and the RFID Portal Body 202 . [0080] In the preferred embodiment the RFID Portal Head 201 preferably has two display screens embedded at the opposite ends. Each RFID Portal incorporates two or more display screens e.g. LCD screens. Of the two display screens, the first screen Screen 1 203 is used for displaying information to the visitor and the second screen Screen 2 204 is used for displaying the information to the security personnel. [0081] In the preferred embodiment the RFID Portal Body 202 has an RFID Reader 205 embedded in it. The RFID reader is used for reading the RFID tags worn by the visitors for controlling the access to the venue. The RFID reader is preferably located at a height so as to be near where the tag is worn on the user's body. In the example shown, the RFID tag might be contained in a wristband or bracelet, and the RFID reader is preferably at approximately natural wrist height for an average visitor. Because of this positioning of the RFID reader, the user/visitor does not need to adopt any specific physical position for the tag to be read (e.g. raise arm to “show” the tag to a security personnel or scanning gun), but can simply walk through the portal naturally. [0082] Each RFID Portal incorporates an RFID reader. Signaling between the RFID Reader 205 and the RFID tag can be done in several different ways, depending on the frequency band used by the RFID tag. RFID tags operating on LF (Low Frequency) and HF (High Frequency) bands are, in terms of radio wavelength, very close to the reader antenna because they are only a small percentage of a wavelength away. An RFID tag is electrically coupled with the transmitter in the reader. The RFID tag can modulate the field produced by the reader by changing the electrical loading the tag represents. By switching between lower and higher relative loads, the RFID tag produces a change that the RFID reader can detect. At UHF (Ultra High Frequency) and higher frequencies, the RFID tag is more than one radio wavelength away from the reader, requiring a different approach. [0083] The RFID Portal may also incorporate one or more indicator LED lights e.g. LED light 206 that is used for communicating certain status information with the visitors. The RFID Portal in addition may also preferably use other sensory methods e.g. auditory beeps may also be used for conveying some or part of the information to the visitors and the security personnel. [0084] The RFID Portal can be self-contained with the RFID reader, electronics for communicating with the connected server and the Portal Head with the two displays screens. Further, the UserIDs can be locally stored in the RFID Portal and compared locally using an onboard processor. Other functions may also be programmed locally and other kinds of data stored locally (e.g. timestamp collection of user visits). [0085] In one embodiment the RFID Portals control the entrance and the exit to a given venue by allowing entrance or denying entrance based on the validity of the RFID tags embedded in wearable items like a wristband. [0086] FIG. 3 shows a second embodiment (or at least a separate perspective) of the RFID portal 300 . The RFID Portal has two main sections the RFID Portal Head 201 and the RFID Portal Body 202 . In the preferred embodiment the RFID Portal Head 201 preferably has two display screens embedded at the opposite ends. Each RFID Portal incorporates two or more display screens e.g. LCD screens. Of the two display screens, the first screen Screen 1 203 is used for displaying information to the visitor and the second screen Screen 2 204 is used for displaying the information to the security personnel. [0087] An indicator LED light 207 may be used for communicating certain status information with the security personnel. Other embodiments may employ LED lights and other sensory methods for conveying information to the security personnel e.g. auditory beeps may also be used for conveying some or part of the information to the security personnel e.g. two short beeps could be used for valid access while a longer louder beep may be used for an invalid access. The auditory beeps may also preferably be accompanied with LEDs e.g. lighting one or more green LEDs implies a valid access while lighting one or more flashing red LEDs implies an invalid access. [0088] FIG. 4 shows one embodiment of the process 400 . The visitor taps the RFID tag on the RFID Portal or simply walks past the RFID Portal such that the RFID tag is read by the reader 401 . [0089] In popular events, at peak times, lines can be long, and having to show a card or other access control credential takes time. In the present system, by allowing the user to just walk past the RFID Portal, the RFID tag in the wearable item can be automatically read and the information displayed to the consumer and the security personnel in two different and separate screens. As the verification of the UserID is done substantially in real time, the user's progress (and progress of the line through the entrance) is not impeded. [0090] The RFID Portal reads the RFID tag 402 . [0091] The system checks the validity of the RFID tag 403 . The validity of the RFID tag can be checked by reading its UserID and passing this UserID to the server for validation. The server may preferably have a database or a list of all valid UserIDs for the RFIDs that are related to an event, the associated balances, a list of recent transactions, age and zone restrictions if any amongst other information about the bearer of the RFID tag. [0092] The system checks whether the RFID tag valid 404 . If the UserID of the RFID tag is not valid 404 a then the user/visitor is disallowed from entering the venue. A notification may be displayed on RFID Portal Screen 1 for the visitor as the visitor is disallowed from entering the venue 405 . Preferably information is also displayed for the visitor noting the reason that they are not allowed to enter e.g. access is denied due to an expired ticket, or due to an age restriction. [0093] The system may also display a notification on RFID Portal Screen 2 for the security personnel 406 . In certain embodiments a security person may also be manning the entrance or exit of a venue. In other embodiments the RFID Portal may be fully automated (e.g. with a turnstile gate) allowing or disallowing entrance to the venue. [0094] If the UserID of the RFID tag is valid 404 b, then the system allows the visitor to enter the venue. Thus only if the UserID of the RFID tag matches with a valid UserID in the list/database on the server then it is considered that the RFID tag is valid. Alternatively, in some embodiments, rather than a “white list” (valid UserIDs) approach, a “black list” approach may be used (i.e. checking for specific banned persons instead). [0095] On verification, a message may be displayed on the RFID Portal Screen 1 welcoming the visitor 407 . Further, a message may be displayed for the security personnel on RFID Portal Screen 2 408 . At this point, the visitor may be allowed to enter the venue 409 . Further information relevant to the visitor may also be provided 410 . [0096] FIG. 5 shows one embodiment of the process flow, specific to age verification 500 . The system preferably checks the age limit when granting access to an age restricted area that requires an age limit (e.g. an alcoholic beverage) 501 . Certain events e.g. a festival may be divided into one or more zones. The different zones in a festival may be required in order to segregate the visitors based on their age or their payment levels. For example a fair may have an area where alcoholic beverages can be sampled or purchased, that is only accessible to persons aged 19 or over and any products/services being vended in this zone may only be sampled/purchased by these people. [0097] For example an event like a fair may have products or services for sale or sampling that are age restricted e.g. alcohol or products aimed at an adult audience. Thus it is important to check the age of a visitor to such an area to ensure that age restricted products and services are only offered to the legal audience. [0098] The system checks whether the visitor is over the age limit, e.g. 19 years 502 . The RFID [0099] Portal reads the RFID UserID and communicates the RFID UserID with the connected server. [0100] The server may store this information so that when an RFID tag is read by an RFID Portal it can verify the age restrictions, zone restrictions/privileges by connecting to the server and querying the UserID of the RFID tag and checking its bearer's restrictions/privileges before allowing the visitor to enter such an area. Alternatively the RFID tag may preferably contain this information that defines the zone(s) where the RFID tag is valid. [0101] If the age of the person associated with the UserID is not valid for the age restricted area 502 a the system preferably displays a notification on RFID Portal Screen 1 and disallows the visitor from entering the age restricted venue 503 . [0102] The system also preferably displays a notification on the RFID Portal Screen 2 for the security personnel 504 . [0103] If the owner of the RFID UserID is valid for the age restricted area 502 b a message may be displayed on the RFID Portal Screen 1 welcoming the visitor 505 . [0104] A message may also be displayed for the security personnel on RFID Portal Screen 2 506 preferably indicating that the visitor is of appropriate age. The system allows the visitor to enter the age restricted area 507 e.g. [0105] Further information may be provided to the visitor that may be relevant 508 , and a sales person may be allowed to vend age-restricted products to the visitor. [0106] The server may preferably store the age or date of birth information about the consumer, so that when an RFID tag is read by the RFID Portal the age can be verified before allowing a visitor to enter the age restricted area. [0107] In another embodiment the RFID tag may preferably contain the age or date of birth information about the visitor. Alternatively the RFID tag and the server both may store the age and date of birth information about the visitor. [0108] FIG. 6 shows one embodiment of the flow, related to data compilation 600 . Real time information is preferably gathered from one or more RFID Portals in communication with a connected server 601 . The RFID Portals may be strategically placed in different areas of a venue and read the RFID tags worn by the visitors. For example the RFID Portals may read the RFID tag of a visitor each time said visitor enters an area or booth, samples or purchases one or more products and then leaves the booth. Information may be gathered as to when a particular visitor entered an area or booth, what products were sampled or purchased in what order they were sampled or purchased, and when did the visitor leave the booth. This may be done using the portals themselves, or the portals may be part of a broader network of RFID readers/terminals throughout an event area/venue. [0109] Preferably, the RFID Portal captures the visitor RFID UserID and timestamp at entry and then at the exit of a vendor booth. The captured visitor RFID UserID and timestamp are saved to the server or the RFID tag or both. In one embodiment this information may be first saved to the RFID tag in realtime, but may be uploaded to the server asynchronously. In an alternate embodiment this information is saved to both the RFID tag and the connected server in realtime. [0110] The system may compile information about visitor movement in the venue 602 . For example a consumer visits a wine and cheese festival and during the visit goes to a cheese outlet booth, then goes to the winery booth and then goes to the beer booth. [0111] The system may compile information about areas/booths visited by the visitor 603 . [0112] For example at a wine and cheese festival, a consumer visits a cheese outlet booth and tries a cream cheese and an aged cheddar cheese; then goes to a winery booth and tries a red wine and a white wine; and subsequently at lunch visits the beer booth and samples different types of beers. A full timestamped log of an individual consumer's activity during a festival may be gathered. [0113] The gathered information may then be compiled 604 . [0114] This compiled information may be shared with the venue organizer and one or more vendors in several ways. For example, basic history or log data for the user may displayed on Screen 2 of the RFID Portal 605 . [0115] The information about all visitors who visited the booth of a particular vendor may include but is not limited to the following: What was the peak time at the booth in terms of traffic What was the slow time at the booth in terms of traffic When most sales were conducted When least sales were conducted Average time consumers spent in the area or booth (by capturing entry time and departure time) Average visitor spending at the vendor In what sequence visitors visited (which area/booth was visited first, which area/booth was visited last etc.) Which products were sampled most Which products were purchased most Which products were sampled least Which products were purchased least [0127] The information about a particular visitor who visited the booth of a particular vendor may include but is not limited to the following: When did the visitor visit the area/booth Was the visit during peak time or during slow time How much time did this visitor spend and how it compares to the average time for all visitors who visited this area/booth How much did this visitor spend and how it compares with the average visitor spending at this vendor In what sequence did this visitor visit the vendor area/booth Which products were sampled Which products were purchased Ratio of sampled products to purchased products [0136] Alternatively compiled information may also be sent to the vendor via an attached file in an e-mail, mailing printed results, a link to the compiled information that is accessible over the internet, and other electronic methods conducive to sharing and sending information over the internet, e.g. after the event is over or at the end of the day for a multi-day event or at given intervals during an event. [0137] Optionally part or complete compiled information may be shared with the visitor. This may be displayed for example on Screen 1 of the RFID Portal 606 . [0138] Alternatively this information may be shared with the visitor after the visit is complete e.g. via an attached file in an e-mail, mailing printed results, a link to the compiled information that is accessible over the internet, and other electronic methods conducive to sharing and sending information over the internet. [0139] In one embodiment the information about a particular visitor who visited the event e.g. the festival or fair may include but is not limited to the following: How many booths did the visitor visit In what order did the visitor visit the area/booths Time spent at each of the area/booths Which products were sampled and or purchased at each area/booth visited How much did the visitor spend in total at the event How much did the visitor spend at each area/booth What products were purchased/sampled by the visitor What products were most popular at the event In what sequence products were sampled at a given area/booth Comparison of visitor time spent at the area/booth with the average time of all visitors at the same booth Comparison of visitor spending at the area/booth with the average spending of all visitors at the same booth [0151] In one embodiment the RFID Portal captures the RFID tag UserID and timestamp at arrival and departure of the visitor to a given vendor booth. [0152] In the preferred embodiment the RFID tag UserID and the VendorID may be captured and stored on the server at the time of entry and at the time of departure. In other alternate embodiments other combinations of VendorIDs and RFID UserIDs may be read at the RFID Portal as the visitor walks past it, and is stored on the RFID tag, the connected server, the sales terminal, the top-up terminal or other such storage device or mechanism. [0153] Thus by tracking the RFID tag UserID of a particular visitor over a period of time when attending a fair or a festival, along with the VendorIDs of the booths visited and the ProductIDs of the products purchased or sampled a complete visitor profile can be assembled that reflects the visitor's purchasing and sampling preferences during that visit. [0154] The above are exemplary and not limiting, in fact the intent is to cover all such information that may be relevant and gathered at an event and shared with the vendors or consumers attending the event. [0155] In one embodiment of the invention the RFID tags are customized before usage. In an alternate embodiment of the invention the system and method of the invention may use generic RFID tag for example RFID tags having an ICODE SLI2 15693. [0156] One embodiment of the invention may use Active Reader Passive Tag (ARPT) system that has an active reader, which transmits interrogator signals and also receives authentication replies from passive RFID tags. [0157] These descriptions exemplify only some of the several possible embodiments of the invention and are not meant to be exhaustive. The intent is to cover all practical possibilities and combinations. [0158] It should be understood that although the term application has been used as an example in this disclosure but in essence the term may also imply to any other piece of software code where the embodiments of the invention are incorporated. The software application can be implemented in a standalone configuration or in combination with other software programs and is not limited to any particular operating system or programming paradigm described here. [0159] The computer program comprises: a computer usable medium having computer usable program code, the computer usable program code comprises: computer usable program code for presenting graphically to the users options for scrolling via the touch-screen interface. [0160] The examples noted here are only for illustrative purposes and there may be further implementation embodiments possible with a different set of components. While several embodiments are described, there is no intent to limit the disclosure to the embodiment or embodiments disclosed herein. [0161] All aspects are illustrative and not restrictive and may be embodied in other forms without departing from their spirit and essential characteristics.

An RFID portal is provided for placing at an access point associated with a temporary event. The access point is controlled by a security control. The portal has a portal body erectable on at least one side of a user pathway at the access point; and an RFID reader in the portal body for reading an RFID tag issued to, and worn by, an individual user for the event that has an encoded unique UserID readable by the RFID reader. The RFID reader is located in the portal body, so as to be physically proximate to a location of the user's body where the RFID tag is worn. The RFID reader is in communication with a server which has stored a list of valid UserIDs for the event. The RFID portal also has an indicator system for receiving notification from the server that the read UserID is a valid UserID for the event and generating an indication to the security control, such that the security control permits the user to proceed along the pathway.

REFERENCE TO A RELATED APPLICATIONS This application is a division of our copending application Ser. No. 773,973 filed Sept. 9, 1985, now U.S. Pat. No. 4,664,907, which in turn is a continuation of copending application Ser. No. 641,812 filed Aug. 17, 1984, abandoned, which in turn is a continuation of copending application Ser. No. 510,452 filed July 1, 1983, abandoned, which in turn is a continuation of copending application Ser. No. 364,035 filed Mar. 31, 1982, abandoned, and all relied on. INTRODUCTION AND BACKGROUND It is known that amorphous synthetic silicas may be used as cleansing agents in toothpastes. Silicas, used as cleansing agents, have the vital advantage over the previously used calcium phosphates and chalks that they do not react with the fluoride ions frequently employed in the form of tin(II) fluoride and sodium fluoride as anti-caries agents, and thus do not block the effect of these additives. Accordingly, there is no need to replace the cleansing agents based on calcium phosphates and chalks by an inert substance. A first vital successful step in this direction was the introduction of amorphous highly porous silica xerogels (U.S. Pat. No. 3,538,230), the combination of which with thickening aerogels, for example Syloid 244®, finally allowed the commercial breakthrough of the use of silica gels in toothpastes. However, it must be pointed out that use had been made much earlier of the viscosity-regulating effect of certain silicas, for example pyrogenic and precipitated silicas having a high degree of structure (German Pat. No. 1,667,875) corresponding to U.S. Pat. No. 3,705,940 and British Pat. No. 1,241,877. In subsequent development, the combination of cleansing agents based on silica xerogels with pyrogenic silicas (German Published Application DAS No. 2,033,678) corresponding to U.S. Pat. No. 3,689,637 and British Pat. No. 1,298,130 and with thickening precipitated silicas having a medium to high degree of structure (British Pat. No. 1,433,743, German Published Application DAS No. 2,610,207 and U.S. Pat. No. 4,132,806) was, logically, also pursued. The next step with regard to the production of improved novel cleansing agents was the development of a specific aluminum silicate produced by precipitation, and the combination of this silicate with a thickening pyrogenic silica or with a thickening precipitated silica of medium to high degree of structure is described in German Pat. No. 2,154,376 corresponding to British Pat. No 1,400,793 and German Published Application DAS No. 2,206,285 corresponding to British Pat. No. 1.372,663. Subsequent development next led to cleansing agents based on precipitated silicas which produced no significant thickening action but had markedly lower abrasiveness than the calcium phosphate cleansing agents. Where these novel SiO 2 -based precipitated silicas are used, the rheology of the toothpastes is not regulated by means of thickening precipitated silicas, but by addition of special binders such as seaweed colloids or synthetic cellulose derivatives (carragheen and sodium carboxymethylcellulose) and by means of vegetable gums (German Laid-Open Application DOS No. 2,344,316; U.S. Pat. No. 4,105,757; German Laid-Open Application DOS No. 2,344,805; U.S. Pat. Nos. 4,122,160 and 4,144,321, and German Laid-Open Application DOS No. 2,522,486) corresponding to U.S. Pat. Nos. 4,067,746 and 4,191,742. Nowadays, a modern cleansing agent based on silicas and intended for use in toothpastes has to provide the following effects: reduced abrasiveness, in the sense of medium polishing activity (Cu abrasion in the finished toothpaste, between 8 and 14 mg), in order to protect the dental enamel, at filler contents in the range of 15-25% by weight, based on the amount of one and the same bifunctional cleansing agent (producing both abrasion and thickening), the viscosity, under conditions which give the above Cu abrasion range, should be between 2,500 and 4,500 mPa.s (determined by the Rotovisko-PK method), the ribbon of toothpaste leaving the tube should be smooth, glossy and free from specks and the dental-care composition containing the cleansing agent should have improved shelf life, in the sense of exhibiting constant abrasiveness and degree of thickening (no after-thickening) for a period of at least one year. It is an object of the invention to conform to the above requirements of a dental-care composition by choice and use of a suitable cleansing agent. SUMMARY OF THE INVENTION We have found that this object is achieved as follows: We resort to a process for the preparation of precipitated silicas which, depending on the manner in which they are milled, gives precipitated silicas having the following physico-chemical characteristics: ______________________________________ Pendulum roller mill Jet mill______________________________________BET surface area determined m.sup.2 /g 15-110 15-110according to DIN 66,131Tamped density determined g/l 150-750 90-650according to DIN 53,194Cu abrasion in 10% strength mg 5-30 5-30glycerol dispersionViscosity of a 30% strength mPa.s 30,000 to 60,000dispersion in a 1:1 glycerol/water mixture (BrookfieldRTV, Sp5)Lightness value A % 86-96 90-96according to DIN 55,921Secondary particle size according accordingdistribution curve according to FIG. 1 to FIG. 2to Coulter counter"ALPINE" screen retainings % by <1.5 <0.1>63 μm weight______________________________________ Such precipitated silicas are very particularly suitable for use in the novel dental-care compositions which are intended to exhibit the pattern properties referred to above. The process for the preparation of precipitated silicas having the above pattern of properties is characterized in that an original precipitated silica suspension, which is prepared by precipitating the silica in an initial charge of alkali metal silicate solution, having a concentration of about 5-25 g of SiO 2 per liter of solution, by means of an acid and alkali metal silicate solution of particular concentrations, at particular feed rates, while maintaining a precipitation temperature in the reaction medium between 80° and 90° C., the precipitation being carried out under such conditions that the viscosity of the reaction medium is kept, for at least 30% of the total precipitation time, at a uniform low value while the pH is kept between 10 and 12, and the addition of the reactants only being terminated when the viscosity, after passing through a maximum, has dropped to a value which is less than 100% above the initial value, is diluted with hot water to a precipitated silica content of 10-30 g/l and a sodium sulfate content of 6-20 g/l, and heated to 85°-95° C., the pH is brought to 7-9 with sulfuric acid and, while keeping this pH value constant, alkali metal silicate solution, sulfuric acid and hot water are added simultaneously over a precipitation period of 30-180 minutes so as to give a final concentration of precipitated silica of 40-80 g/l, the suspension is acidified with concentrated sulfuric acid to a pH below 7, and the precipitated silica is separated from the suspension by means of a filter press, washed out, dried and milled by means of a pendulum roller mill or jet mill. In a preferred embodiment, it is possible to use an original precipitated silica suspension which has been subjected to intensive shearing during its phase of preparation according to German Published Application DAS No. 1,467,019. This is of advantage whenever particularly high Cu abrasion values are to be achieved. In a particular embodiment of the invention, shearing can be effected according to German Pat. No. 1,767,332. The present invention provides a dental-care composition having improved shelf life in respect of rheology and abrasiveness, which contains, as a thickener and abrasive, a precipitated silica characterized by the following physico-chemical properties: ______________________________________BET surface area determined m.sup.2 g 15-110according to DIN 66,131Tamped density g/l 90-650Secondary particle sizedistribution curve accor-ding to Coulter counter according to FIG. 2"ALPINE" screen retainings % by <0.1>63 μm weightCu abrasion in 10% strength mg 5-30glycerol dispersionViscosity of a 30% strength mPa.s 30,000-60,000dispersion in a 1:1 water/glycerol mixture (BrookfieldRTV Sp 5)Lightness value A % 90-96according to DIN 55,921______________________________________ The dental-care composition according to the invention exhibits the following advantageous properties: it possesses mild abrasiveness, in the sense of medium polishing action on the surface of the teeth, without damaging the dental enamel, if 15-25% by weight of cleansing agent, based on a single silica, are used, mild abrasion (8-14 mg Cu abrasion) coupled with optimum rheology of the paste (viscosity between 2,500 and 4,500 mPa.s determined by the Rotovisko method) can be achieved, the ribbon of toothpaste is smooth, speck-free and glossy and the toothpaste exhibits improved shelf life in respect of constancy of abrasiveness and thickening (without after-thickening). The invention further provides a dental-care composition with improved shelf life in respect of rheology and abrasiveness, which contains, as the abrasive, a precipitated silica characterized by the following physico-chemical properties: ______________________________________BET surface area determined m.sup.2 /g 15-110according to DIN 66,131Tamped density g/l 150-750Secondary particle size dis-tribution according to FIG. 1"ALPINE" screen retainings % by <1.5>63 μm weightCu abrasion in 10% strength mg 5-30glycerol dispersionViscosity of a 30% strength mPa.s 30,000-60,000dispersion in a 1:1 glycerol/water mixture (BrookfieldRTV Sp5)Lightness value A % 86-96according to DIN 55,921______________________________________ The dental-care composition according to the invention can have a total precipitated silica content of 17 to 25% by weight, preferably of 17 to 22% by weight. If the abrasive silica is used as the sole silica component, its concentration is 20 to 25% by weight, preferably 20 to 22% by weight. If mixtures of abrasive precipitated silica and thickening precipitated silica are employed, the following concentrations result: 15 to 20% by weight of abrasive precipitated silica, 2 to 14% by weight, preferably 2 to 10% by weight, of thickening silica. This novel dental-care composition has the following advantageous properties: it possesses mild abrasiveness, in the sense of medium polishing action on the surface of the teeth, without damaging the dental enamel, improved shelf life in respect of constant abrasiveness and thickening (without after-thickening) for a period of at least one year. In a particular embodiment, 0.5-5% by weight of polyethylene glycol having a molecular weight in the range from 400 to 2,000 may be added, as a thickener, to the recipe of the dental-care composition. This measure has the effect of either reducing the amount of cleansing agent needed for a given final viscosity of the dental-care composition or of producing, at constant cleansing agent concentration, a higher viscosity of the toothpaste (for example, a different viscosity may be needed depending on whether the toothpaste is packed in a tube or a dispenser). In a further embodiment, there may also be added to the toothpaste recipe 2-14% by weight, preferably 2-10% by weight, of a precipitated silica, available, for example, under the trademarks FK 320 DS, Siperant 22 S®, FK 300 DS, ZeoSil 200 or Sident 11®, which in 15% strength dispersion in a 1:1 glycerol/water mixture has a viscosity of not less than 30,000 mPa.s., or 0.5-4% by weight, preferably 2-4% by weight, of a pyrogenic silica which is available, for example, under the tradenames Aerosil 200®, Cabosil M5®, Aerosil 200 V® or HDK N 20 E, together with cleansing agents, as thickener. In this way, the polishing action of the dental-care composition can be increased by using a silica cleansing agent which has a marked abrasive action but is in general a less effective thickener, if, at the same time, the reduction in thickening action is compensated by addition of precipitated silicas or pyrogenic silicas having an appropriate thickening action. This situation applies, for example, when formulating a smoker's toothpaste. By combination of the SiO 2 cleansing agents, used in the novel dental-care composition, with thickening additives such as polyethylene glycol or pyrogenic or precipitated silica, the dental cosmetician is provided with means which allow him a substantial extension of the usefulness of the novel dental-care compositions. At the same time it is to be borne in mind that these embodiments also have substantially improved properties in respect of shelf life of the composition. Of course, the dental-care compositions according to the invention can be prepared either in a transparent or in an opaque form. Principal constituents of transparent toothpastes: water, glycerol and cleansing agent, the latter being silicon dioxide (silica). Subsidary constituents: binders, eg. carboxymethylcellulose, preservatives (eg. sodium benzoate), sweetner (eg. saccharin), aromatic oils, foaming agents (eg. sulfonates), active ingredients, eg. fluorides, and dyes. Principal constituents of opaque pastes: cleansing agents, water and sorbitol. In opaque pastes, the cleansing agents may also include chalks, aluminum hydroxides and calcium phosphates in addition to silicas and amorphous silicates (sodium aluminosilicates). Subsidary constituents: binders (eg. carboxymethylcellulose), preservatives (eg. Na benzoate), sweetener (eg. saccharin), opacifiers (eg. TiO 2 ), active ingredients (eg. fluorides), foaming agents (eg. sulfonates) and, if desired, dyes. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be further understood with reference to the drawings, wherein: FIG. 1 is a graph of weight percent versus particle size for secondary particle size distribution produced by a pendulum roller mill; FIG. 2 is a graph of weight percent versus particle size for secondary particle size distribution produced by a jet mill; FIG. 3 is a graph of weight percent versus particle size for secondary particle size distribution for a xerogel, and FIG. 4 is a graph of weight percent versus particle size for secondary particle size distribution of another xerogel. DETAILED DESCRIPTION OF THE INVENTION The examples which follow illustrate and describe the novel dental-care compositions in comparison with prior art compositions. The precipitated silicas, pyrogenic silicas and silica xerogels used to prepare the dental-care compositions are summarized in Survey Table No. 1 on page 12 together with those of their physico-chemical data which are considered relevant to their use in toothpastes. In the examples section, the letters A-I are employed in connection with the recipe and the description of the results. The letters A-D designate the abrasive silicas used in the dental-care composition according to the invention. In addition to the silica-containing toothpaste fillers listed in the table, the following fillers are used for comparative experiments: chalk (CaCO 3 ), produced by Schafer, Diez/Lahn, West Germany. Dicalcium phosphate dihydrate, produced by Benckiser-Knapsack, West Germany. Titansium dioxide RN 56, produced by Kronos AG, West Germany. All other toothpaste raw materials contained in the recipes given are listed in alphabetical order, together with information on suppliers, in Survey Table No. 2. To demonstrate the technical effects, and for comparative investigations, essentially four basic recipes are used in the examples section, namely: An opaque sorbitol paste which contains 40% by weight of sorbitol as the main constituent. A transparent glycerol paste which contains 60% by weight of glycerol as the main constituent. A chalk paste containing glycerol. A phosphate paste containing sorbitol and glycerol. The exact composition of the pastes investigated is in each case given in detail in the corresponding example sections. As a rule, an increase in the content of cleansing agent is compensated by a decrease in the water content. To produce the pastes, the components are compounded in a RETSCH mill, homogenized three times on a triple-roll mill and then deaerated in a desiccator using a vacuum pump. TABLE No. 1__________________________________________________________________________Precipitated silicas, pyrogenic silicas and silica xerogels, the use ofwhich indental-care compositions is described in the examples. Commer- Commer- Commer- Commer- cial cial cial Commercial cial precipi- pyrogenic precipi- SiO.sub.2 SiO.sub.2 tated silica, tatedPhysico-chemical Abrasive Abrasive Abrasive Abrasive xerogel, xerogel, silica, Aerosil silicacharacteristics silica silica silica silica Syloid AL1 Syloid 63 FK 320DS 200 V FK 300 DSType: A B C D E F G H I__________________________________________________________________________Bet surface area, m.sup.2 /g 103 101 70 51 633 719 170 200 300Secondary particle FIG. 1 FIG. 2 FIG. 2 FIG. 2 FIG. 3 FIG. 4 FIG. 2 -- FIG. 2size distribution,according toCoulter Counter"ALPINE" screen 1.4 0.1 0.1 0.1 <0.1 <0.1 -- -- --retainings>66 μm (% by weight)Cu abrasion* (mg) 14 8 12 17 7-8 11-12 <1 mg <1 mg <1 mgViscosity** (mPa.s) 36,000** -- 38,400** 33,500** not not 52,200*** -- 54,000*** measurable, measurable, too mobile too mobileLightness 94.4 96.8 95.7 94.6 . . 94.1 . . . . . .value A (%)__________________________________________________________________________ *in 10% strength glycerol dispersion **in 30% dispersion in a 1:1 glycerol/water mixture ***in 15% strength dispersion in a 1:1 glycerol/water mixture TABLE No. 2______________________________________Toothpaste raw materials and source of supply (exceptingfillers) SupplierRaw material Chemical name company______________________________________aromatic oil peppermint oil, Haarmann and oil of wintergreen Reimer, DragocoDehydazol A 400 P carboxymethylcellulose Henkel0.5% strength dye foodstuff dyes Siegle-FarbensolutionGlycerol glycerol, German Merck Pharmacopeia 7Polyethylene glycol polyethylene glycol Merck400Polyethylene glycol polyethylene glycol Merck1500liquid paraffin paraffin Mercksaccharin benzoic acid sulfimide Bayersodium saccharin sodium salt of Bayer benzoic acid sulfimideSolbrol M methyl p-hydroxy- Bayer benzoateSolbrol M-Na sodium salt of methyl Bayer p-hydroxybenzoatesorbitol sorbitol Maizena Karion F (70% strength Merck aqueous sugar solution)Texapon K 12 sodium laurylsulfonate Henkel______________________________________ Description of test methods and methods of measurement: DETERMINATION OF Cu ABRASION IN 10% STRENGTH GLYCEROL DISPERSION (a) Preparation of the glycerol dispersion 153 g of anhydrous glycerol (German Pharmacopeia 7; density=1.126 g/ml) are weighed into a 250 ml polyethylene beaker. 17 g of cleansing agent are carefully mixed into it by means of a spatula. The mixture is then homogenized with a paddle stirrer (diameter 5.2 cm) for 12 minutes at 1,500 rpm. (b) Method of measurement of abrasion The abrasion is measured in an abrasion tester disclosed in the following publications: (1) Pfrengle: Fette, Seifen, Anstrichmettel, 63 (5) (1961), pages, 445 to 451 "Abrasion und Reinigungskraft von Putzkorpern in Zahnpasten" ("Abrasion and Cleansing Power of Polishing Agents in Toothpastes") (2) A. RENG and F. DANY, Parfumerie und Kosmetik 59 (2) (1978), pages 37 to 45; "Anwendungstechnische Prufung von Zahnpasten" ("Performance Testing of Toothpastes"). For this purpose, the 6 troughs of the test apparatus were each covered with 20 ml of the homogeneous dispersion. The abrasion produced by six plane-ground nylon brushes on six plane-ground Cu sheets (electrolytic copper) in five hours as a result of 50,000 reciprocating strokes is determined by differential weighing. In calculating the abrasiveness, the means of the values obtained are taken. The abrasion (abrasiveness) is quoted in mg of Cu. DETERMINATION OF Cu ABRASION OF OPAQUE AND TRANSPARENT TOOTHPASTES (a) Preparation of the toothpastes See above description (b) Method of measurement of abrasion 1. Principle An important piece of information concerning the quality of the toothpaste is the abrasiveness, which as a rule is determined by the RDA method and by the copper abrasion method. The values obtained give important information on the cleansing action and abrasive action on the dental enamel and the neck of the tooth. To carry out the test, a suspension is prepared from the toothpaste and glycerol, and the abrasiveness of this mixture is determined with the abrasion tester. 2. Apparatus and reagents Triple-roll mill (Optimat 1) Abrasion tester Analytical balance Oven Glycerol, anhydrous, German Pharmacopeia 7 (density=1.26 g/ml), Toothpastes 3. Method 3.1. Preparation of the paste suspension 75 g of glycerol are stirred into 100 g of the toothpaste, in a porcelain dish, by means of a spatula, and the mixture is then homogenized 4 times on a triple-roll mill. The paste suspension obtained is used for abrasion testing. 3.2. Measurement of abrasion The determination is carried out in the abrasion tester. Six cleaned, plane-ground, accurately weighed electrolytic copper sheets are placed in the six troughs of the test apparatus. 20 ml of the homogeneous dispersion are then introduced into each. Plane-ground nylon brushes are placed on the Cu sheets. The test is carried out with 50,000 double strokes (requiring about 5 hours). After completion of the determination, the copper sheets are rinsed first with water and then with acetone and are dried in a desiccator. The completely dry Cu sheets are accurately weighed and the weight difference is quoted as the abrasiveness, in mg of Cu. In the evaluation, any outliers are ignored, and the mean of the remaining values is taken. 4. Evaluation The abrasiveness is quoted in mg of Cu. Weight of Cu sheet before determination minus weight of Cu sheet after determination=loss of electrolytic copper in mg=abrasiveness. ______________________________________Test of rheological activity of abrasive silicas in a 30%strength dispersion in a l:l glycerol/water mixture______________________________________1. Sample mixes 60 g of silica 70 g of anhydrous glycerol, German Pharmacopeia 7, density 1.26 g/ml 70 g of distilled water 200 g = 30% strength silica dispersion______________________________________ 2. Method The abrasive silicas are stirred manually for 1 minute, using a glass rod, into the glycerol/water mixture in a 400 ml beaker (squat form), and the mixture is left to stand for 24 hours, after which the viscosity is measured. 3. Measurement The viscosity is measured in the same beaker, using the Brookfield RVT viscometer, spindle 5, at various speeds of revolution. 4. Calculation Scale reading×factor=viscosity in mPa.s. ______________________________________Test of rheological activity of thickening silicas in a 15%strength dispersion in a 1:1 glycerol/water mixture______________________________________1. Sample mix 30 g of silica 85 g of anhydrous glycerol, German Pharmacopeia 7, density 1.26 g/ml 85 g of distilled H.sub.2 O 200 g = 15% strength silica dispersion______________________________________ 2. Method The thickening silica is stirred manually for 1 minute, using a glass rod, into the glycerol/water mixture in a 400 ml beaker (squat form), and the mixture is left to stand for 24 hours, after which the viscosity was measured. 3. Measurement The viscosity is measured in the same beaker, using the Brookfield RVT viscometer, spindle 5, at various speeds of revolution. 4. Calculation Scale reading×factor=viscosity in mPa.s. DETERMINATION OF VISCOSITY OF TOOTHPASTES (a) Preparation of the toothpastes See above description (b) Method of measurement of viscosity Testing the toothpaste viscosity on a Rotoviscometer, plate and cone system 1. Apparatus Rotovisko from Haake, Karlsruhe, West Germany, with thermostat, measuring head 50, plate-and-cone No. 8012 and 1224. 2. Method The toothpaste is first brought to 20°-22° C. and a small amount is then applied with the end of a spatula to the plate. The measurement is carried out at speed level 27. After 30 seconds, the scale value is read off the indicator, since after this time an approximately constant value has been reached. 3. Evaluation From the speed, pointer reading and calibration constant of the plate-and-cone system used, the viscosity of the paste is found from the equation V=K.S.U[mPa.s] where V=viscosity in mPa.s U=speed level of the Rotovisko S=scale reading K=calibration constant of the cone used DETERMINATION OF THE PH OF TOOTHPASTES (a) Preparation of the toothpastes See above description (b) Method of pH measurement The pH of toothpastes is extremely important since it can greatly affect the stability of a paste. Extremely alkaline and extremely acid pastes are as a rule undesirable, since they may cause bulging and corrosion of the aluminum tubes. Moreover, in the case of medicated toothpastes, the active ingredient may be chemically attacked and decomposed. Pastes having a neutral pH are therefore preferred. 1. Apparatus Laboratory pH-meter type 26 from Knick, with glass electrode. 2. Method The glass electrode is dipped into the toothpaste and after about 3 minutes the pH is read directly from the indicator. VISUAL METHODS OF ASSESSMENT OF DENTAL-CARE COMPOSITIONS (a) Assessment of the ribbon stability of a toothpaste 1. Method The toothpaste is packed in an aluminum tube and a ribbon about 5 cm long is then squeezed out onto a glass plate. 2. Assessment The stability of the ribbon is assessed after 5 minutes. If the paste has inadequate consistency, the ribbon is seen to have spread. Depending on the width of the ribbon being assessed, the stability is rated 1-4. (b) Assessment of the transparency of a transparent toothpaste 1. Method (a) the paste is squeezed out between 2 glass plates or (b) the paste is applied to a white sheet with black lines. 2. Assessment re (a) The transparency of the paste may be judged very easily, since inadequate quality immediately manifests itself by clouding. Depending on the degree of clouding, the transparency is rated 1-4. re (b) If the paste has good transparency, the black line is very clearly discernible through the ribbon of toothpaste. If the transparency is less good, the line is more or less blurred. The transparency is rated 1-4. (c) Assessment of the separation of toothpastes 1. Method The paste is stored in aluminum tubes for 3 months at 45° C. and thereafter a ribbon about 5 cm long is pressed onto blotting paper. 2. Assessment If the toothpaste has a tendency to separate, a film of moisture extending from the ribbon is readily visible in the blotting paper. Depending on the width of this film, the separation is rated 1-4. Notes The method described should be used as a rule, since in a few cases the separation is so pronounced that a layer of liquid even forms at the tube nozzle. 1ST SERIES OF EXAMPLES This series of examples is intended to demonstrate that the novel dental-care composition containing the cleansing agents specified therein, which fulfils the double function of thickening and abrasiveness, meets today's market requirements in respect of abrasiveness and consistency of opaque toothpastes, without other additives. Commercial cleansing agents based on silica gels do not exhibit these properties, as demonstrated by the comparative experiments in the 1st series of examples. The composition of the investigated opaque pastes is described in more detail in Table No. 3 (recipes 1-12). Table No. 4 shows the results (pH, Cu abrasion, viscosity, ribbon stability and separation) of the measurements carried out on recipes 1-12. It follows from the results that: Recipes No. 3 and No. 6, according to the invention, containing 25% by weight of cleansing agent B and C respectively, give toothpastes with stable ribbons and with an abrasiveness in the range of 8-13 mg of Cu, which fully conforms to market requirements. Recipe No. 9 according to the invention, with 25% by weight of the harder cleansing agent D, forms a paste which, without additives, still retains a tendency to flow. However, its abrasiveness, namely 16-18 mg of Cu, conforms to what is generally expected from highly-cleansing toothpastes, for example smoker's toothpastes. Recipe No. 12, formulated with 25% by weight of commercial cleansing agents, gives a toothpaste which does not form a stable ribbon. Moreover, even at such a high filler content, the abrasiveness, namely 4-6 mg of Cu, is very low. TABLE No. 3__________________________________________________________________________Opaque dental-care compositions: Double function of cleansing agents.Recipes without additives. Consecutive No.Recipe 1 2 3 4 5 6 7 8 9 10 11 12__________________________________________________________________________Distilled water 40.35 35.35 30.35 40.35 35.35 30.35 40.35 35.35 30.35 40.35 35.35 30.35Dehydazol A 1.00 → → → → → → → → → → →400 PSolbrol M-Na 0.15 → → → → → → → → → → →Saccharin-Na 0.10 → → → → → → → → → → →Sorbitol 40.00 → → → → → → → → → → →TiO.sub.2 RN56 0.40 → → → → → → → → → → →Liquid paraffin 0.50 → → → → → → → → → → →Aromatic oil 0.50 → → → → → → → → → → →Texapon K 12 2.00 → → → → → → → → → → →Silica B 15.00 20.00 25.00 -- -- -- -- -- -- -- -- --Silica C -- -- -- 15.00 20.00 25.00 -- -- -- -- -- --Silica D -- -- -- -- -- -- 15.00 20.00 25.00 -- --Silica E -- -- -- -- -- -- -- -- -- 15.00 20.00 25.00Sum: 100.00 → → → → → → → → → → →__________________________________________________________________________ TABLE No. 4______________________________________Opaque dental-care compositions:Double function of cleansing agents.Results with additives.Recipe/Properties Abrasion Viscosity Ribbon Separa-Consecutive No. pH mg of Cu mPa.s stability tion______________________________________1 5.0 7-8 1,116 Rating 4 Rating 14 5.2 8-9 930 Rating 4 Rating 17 4.8 12-15 806 Rating 4 Rating 110 4.1 2-3 too Rating 4 Rating 3 mobile2 5.3 7-9 1,860 Rating 3 Rating 15 6.2 8-11 1,736 Rating 3 Rating 18 5.8 13-16 1,364 Rating 4 Rating 111 4.2 2-3 868 Rating 4 Rating 33 5.4 8-10 3,348 Rating 1 Rating 16 5.8 11-13 2,914 Rating 1 Rating 19 5.4 16-18 2,604 Rating 3 Rating 112 4.0 4-6 1,860 Rating 3 Rating 1______________________________________ 2ND SERIES OF EXAMPLES This series of examples is intended to show that the dental-care compositions according to the invention, containing the cleansing agents which are specified in more detail in the claims and have a pronounced double function of thickening and abrasiveness, when used together with additives based on polyethylene glycols conform, in the case of transparent toothpastes, to present-day market requirements in respect of abrasiveness, transparency and consistency. Commercial cleansing agents based on silica gel do not exhibit these properties, as demonstrated by the comparative tests in the 2nd series of examples. The composition of the transparent pastes investigated is described in more detail in Table No. 5 (recipes 1-12). TABLE No. 5__________________________________________________________________________Transparent dental-care compositions: Double function of cleansingagents.Recipes with additive Consecutive No.Recipe 1 2 3 4 5 6 7 8 9 10 11 12__________________________________________________________________________Distilled water 17.95 17.95 12.95 12.95 17.95 17.95 12.95 12.95 17.95 17.95 12.95 12.95Blue dye solution 0.50 → → → → → → → → → → →Dehydazol A 400 P 0.50 → → → → → → → → → → →Solbrol M-Na 0.15 → → → → → → → → → → →Saccharin-Na 0.10 → → → → → → → → → → →Glycerol 60.00 → → → → → → → → → → →Polyethylene glycol 400 3.50 -- 3.50 -- 3.50 -- 3.50 -- 3.50 -- 3.50 --Polyethylene glycol 1500 -- 3.50 -- 3.50 -- 3.50 -- 3.50 -- 3.50 -- 3.50Aromatic oil 1.00 → → → → → → → → → → →Texapon K 12 1.30 → → → → → → → → → → →Silica A 15.00 15.00 20.00 20.00 -- -- -- -- -- -- -- --Silica C -- -- -- -- 15.00 15.00 20.00 20.00 -- -- -- --Silica E -- -- -- -- -- -- -- -- 15.00 15.00 20.00 20.00Sum: 100.00 → → → → → → → → → → →__________________________________________________________________________ TABLE No. 6__________________________________________________________________________Transparent dental-care compositions: Double function of cleansing agentswith additiveResultsRecipe Abrasion ViscosityConsecutive No. pH mg of Cu mPa.s Ribbon stability Separation Transparency__________________________________________________________________________1 7.6 16 1,100 Rating 4 Rating 1 Rating 25 7.8 14 1,302 Rating 4 Rating 1 Rating 29 5.9 7 not measurable Rating 4 Rating 4 Rating 42 7.2 15 1,320 Rating 3 Rating 1 Rating 26 7.9 12 1,612 Rating 3 Rating 1 Rating 210 6.0 5 not measurable Rating 4 Rating 4 Rating 43 7.5 18 1,980 Rating 3 Rating 1 Rating 27 7.7 14 2,480 Rating 2 Rating 1 Rating 211 5.8 6 868 Rating 4 Rating 1 Rating 44 7.4 17 2,980 Rating 1 Rating 1 Rating 28 7.7 13 3,410 Rating 1 Rating 1 Rating 212 5.8 6 1,550 Rating 3 Rating 1 Rating 4__________________________________________________________________________ Table No. 6 shows the results (pH, Cu abrasion, viscosity, ribbon stability, separation and transparency) of the measurements carried out on recipes 1-12. It follows that: Recipes No. 4 and No. 8 according to the invention, containing 20% by weight of cleansing agents A and C respectively and 3.5% of polyethylene glycol 1,500, give toothpastes which produce stable ribbons and have an abrasiveness which fully conforms to market requirements. Recipes No. 11 and No. 12, formulated with 20% by weight of commercial cleansing agents, do not form stable-ribbon toothpastes either with 3.5% of polyethylene glycol 400 or with polyethylene glycol 1,500. The transparency of these pastes is also unsatisfactory. 3RD SERIES OF EXAMPLES This series of examples is intended to demonstrate that the dental-care composition according to the invention containing the cleansing agents which have the double function of thickening and abrasiveness, together with additives based on polyethylene glycols, conform to present-day market requirements in respect of abrasiveness and consistency and are even superior in respect of the amount of cleansing agent to be employed. Commercial cleansing agents based on silica gel do not exhibit this property even in the presence of 5% of polyethylene glycol 1,500, as is demonstrated by the comparative tests of the 3rd series of examples. The composition of the opaque pastes investigated is described in more detail in Table No. 7 (recipes 1-12). Table No. 8 gives the results (pH, Cu abrasion, viscosity, ribbon stability and separation) of the measurements carried out on recipes 1-12. It follows from these that: Recipes No. 4, No. 7 and No. 8 according to the invention, containing 20% by weight of cleansing agent A or C and 2% by weight or 5% by weight of polyethylene glycol 1,500, form stable-ribbon toothpastes whose abrasiveness fully conforms to market requirements. Recipes No. 9, No. 10, No. 11 and No. 12, formulated with 20% by weight of commercial cleansing agents, do not form stable-ribbon toothpastes either with 2% by weight or with 5% by weight of polyethylene glycol 400 or polyethylene glycol 1,500. TABLE No. 7__________________________________________________________________________Opaque dental-care compositions: Double function of cleansing agents.Recipes with additive Consecutive No.Recipe 1 2 3 4 5 6 7 8 9 10 11 12__________________________________________________________________________Distilled water 33.35 30.35 33.35 30.35 33.35 30.35 33.35 30.35 33.35 30.35 33.35 30.35Dehydazol A400P 1.00 → → → → → → → → → → →Solbrol M-Na 0.15 → → → → → → → → → → →Saccharin-Na 0.10 → → → → → → → → → → →Sorbitol 40.00 → → → → → → → → → → →Polyethylene glycol 400 2.00 5.00 -- -- 2.00 5.00 -- -- 2.00 5.00 -- --Polyethylene glycol 1500 -- -- 2.00 5.00 -- -- 2.00 5.00 -- -- 2.00 5.00TiO.sub.2 RN 56 0.40 → → → → → → → → → → →Liquid paraffin 0.50 → → → → → → → → → → →Aromatic oil 0.50 → → → → → → → → → → →Texapon K12 2.00 → → → → → → → → → → →Silica A 20.00 20.00 20.00 20.00 -- -- -- -- -- -- -- --Silica C -- -- -- -- 20.00 20.00 20.00 20.00 -- -- -- --Silica E -- -- -- -- -- -- -- -- 20.00 20.00 20.00 20.00Sum: 100.00 → → → → → → → → → → →__________________________________________________________________________ TABLE No. 8______________________________________Opaque dental-care compositions:Double function of cleansing agents with additive.ResultsRecipeConsecutive Abrasion Viscosity RibbonNo. pH mg of Cu mPa.s stability Separation______________________________________1 5.6 13 1,860 Rating 3 Rating 15 5.9 12 2,348 Rating 2 Rating 19 4.0 5 1,040 Rating 4 Rating 12 5.7 12 2,120 Rating 2 Rating 16 5.5 10 2,506 Rating 2 Rating 110 4.1 4 1,320 Rating 3 Rating 13 5.5 15 2,450 Rating 2 Rating 17 5.8 12 2,640 Rating 1 Rating 111 4.0 6 1,220 Rating 3 Rating 14 5.6 14 3,120 Rating 1 Rating 18 5.9 13 3,320 Rating 1 Rating 112 4.1 6 1,580 Rating 3 Rating 1______________________________________ 4TH SERIES OF EXAMPLES The series of examples which follows is intended to demonstrate the marked superiority of the cleansing agents used in the dental-care compositions according to the invention, in respect of their abrasion and also of their thickening action, compared to commercial cleansing agents based on silica gels. In order to highlight the differences more clearly, use is made of a thickening precipitated silica, for example FK 320 DS. The test results show that, at a constant degree of filling of 22% by weight, the abrasive action and thickening action in the dental-care compositions according to the invention can be varied by the choice of the ratio of abrasive component to thickening component. By comparison, this variability is very greatly restricted when using commercial cleansing agents. The composition of the opaque toothpastes investigated is described in more detail in Table No. 9 (recipes 1-20). Table No. 10 contains the results (pH, Cu abrasion and viscosity) of the measurements carried out on recipes 1-20. The conclusions for recipes 1-10 are as follows: Recipes No. 1-No. 5 according to the invention, having a total silica content of 22% by weight, in every case conform to what the market requires of a dental-care composition. This is also true of those formulations which contain either none, or only 2% by weight, of a thickening precipitated silica (type G). On increasing the content of thickening component while at the same time lowering the content of cleansing agent (type C), the toothpastes obtained give very stable ribbons and, because of their relatively high viscosity, permit savings of thickening silica. In contrast, recipes No. 8-No. 10, tested for comparison and having the same total silica content, but containing cleansing agent type E, are insufficiently viscous. Only with recipes No. 6 and No. 7, which contain 12 and 14% by weight of thickening silica (type G), are toothpastes with an acceptable consistency obtained. In recipes No. 1-No. 5 according to the invention, and also in comparative recipes No. 6-No. 10, the abrasiveness does not increase linearly with increasing content of cleansing agent type C or type E. However, the increase in abrasiveness, viewed in absolute terms, is greater in the recipes according to the invention, containing cleansing agent of type C, than in the comparative recipes, containing the commercial cleansing agent of type E. As regards the results, shown in Table No. 10, of the measurements on recipes No. 11-No. 20, the conclusions are: Recipes No. 11-No. 20 according to the invention, having a total silica content of 22% by weight, substantially conform to what the market requires of a dental-care composition. Formulations No. 14, No. 15, No. 19 and No. 20, which contain none, or only 2% by weight, of a thickening precipitated silica (type G), tend to flow. On increasing the content of thickener component, while at the same time lowering the content of cleansing agent component (types A and D), toothpastes are obtained which give very stable ribbons and whose recipes, because of their relatively high level of thickening, permit savings of thickening silica. In the cleansing agents according to the invention, of type A and type D, Cu abrasion values in the range of 11-18 mg of Cu can be obtained, made-to-measure, depending on the composition of the recipes in respect of abrasive component and thickening component. Even in the extreme case where only abrasive component is used, the ribbon stability remains good. However, it is found that the Cu abrasion values increase far from linearly with the concentration of the abrasive component while on the other hand the abrasiveness of the dental-care compositions according to the invention can be selected within relatively wide limits without having to sacrifice other important properties of the composition, such as ribbon stability and separation stability. This is not true when using the commercial cleansing agent (type E) based on silica gel. TABLE No. 9__________________________________________________________________________Opaque dental-care compositions: Double function of cleansing agents.Recipes contain precipitated silicas having a thickening__________________________________________________________________________action. Consecutive No.Recipe 1 2 3 4 5 6 7 8 9 10__________________________________________________________________________Distilled water 33.40 → → → → → → → → →Dehydazol A 400P 1.00 → → → → → → → → →Solbrol M 0.15 → → → → → → → → →Saccharin-Na 0.05 → → → → → → → → →Sorbitol 30.00 → → → → → → → → →Glycerol 10.00 → → → → → → → → →TiO.sub.2 RN 56 0.40 → → → → → → → → →Liquid paraffin 0.50 → → → → → → → → →Aromatic oil 0.50 → → → → → → → → →Texapon K 12 2.00 → → → → → → → → →Silica C 8.00 10.00 14.00 20.00 22.00 -- -- -- -- --Silica E -- -- -- -- -- 8.00 10.00 14.00 20.00 22.00Silica G 14.00 12.00 8.00 2.00 -- 14.00 12.00 8.00 2.00 --Sum: 100.00 → → → → → → → → →__________________________________________________________________________ Consecutive No.Recipe 11 12 13 14 15 16 17 18 19 20__________________________________________________________________________Distilled water 33.40 → → → → → → → → →Dehydazol A 400P 1.00 → → → → → → → → →Solbrol M 0.15 → → → → → → → → →Saccharin-Na 0.05 → → → → → → → → →Sorbitol 30.00 → → → → → → → → →Glycerol 10.00 → → → → → → → → →TiO.sub.2 RN 56 0.40 → → → → → → → → →Liquid paraffin 0.50 → → → → → → → → →Aromatic oil 0.50 → → → → → → → → →Texapon K 12 2.00 → → → → → → → → →Silica A 8.00 10.00 14.00 20.00 22.00 -- -- -- -- --Silica D -- -- -- -- -- 8.00 10.00 14.00 20.00 22.00Silica G 14.00 12.00 8.00 2.00 -- 14.00 12.00 8.00 2.00 --Sum: 100.00 → → → → → → → → →__________________________________________________________________________ TABLE No. 10______________________________________Opaque dental-care compositions:Double function of cleansing agents.Recipes contain precipitated silicas having athickening action.ResultsRecipe Abrasion Viscosity Assessment ofConsecutive No. pH mg of Cu mPa.s ribbon stability______________________________________1 4.9 8-9 6,000 Rating 12 5.2 9-11 5,270 Rating 13 5.3 10-12 4,650 Rating 14 5.5 13-14 3,800 Rating 15 5.4 13-15 3,100 Rating 16 4.4 2-3 5,200 Rating 17 4.2 2-3 3,400 Rating 18 4.2 3-4 2,700 Rating 29 4.1 5 1,800 Rating 310 4.2 5-6 1,300 Rating 411 5.0 11-13 5,952 Rating 112 5.2 10-12 5,230 Rating 113 5.5 12-14 4,430 Rating 114 5.0 13-15 3,100 Rating 215 5.5 16-18 2,840 Rating 216 5.0 12-14 5,890 Rating 117 5.0 14-16 4,960 Rating 118 5.1 15-17 4,340 Rating 119 5.4 16-18 2,914 Rating 220 5.0 16-18 2,790 Rating 2______________________________________ 5TH SERIES OF EXAMPLES The series of examples which follows is intended to provide experimental proof that the use of a few percent of thickening pyrogenic silica, eg. Aerosil®200V, in combination with the cleansing agents used in the dental-care compositions according to the invention gives toothpastes which in respect of abrasion and thickening characteristics are entirely comparable with commercial dental-care compositions now on the market. The series of examples also shows that by the use of pyrogenic silicas, as components which help determine the rheology, the total content of silica filler can be markedly reduced. The composition of the opaque toothpastes investigated is shown in more detail in Table No. 11 (recipes No. 1-No. 4). Table No. 12 contains the results (pH, Cu abrasion and viscosity) of the measurements on recipes No. 1-No. 4. It follows from these that: Using the pyrogenic silica Aerosil®200 V as a thickening silica, the total silica content in an opaque dental-care composition according to the invention can be reduced to 17% by weight if, at the same time, 14% by weight of cleansing agent C and 3% by weight of thickening silica of type H are employed. In that case, the characteristics of a commercial opaque toothpaste, in respect of abrasion and rheological properties, are obtained. TABLE No. 11______________________________________Opaque dental-care compositions: Double function ofcleansing agents. Recipes contain pyrogenic silica havinga thickening action. Consecutive No.Recipe 1 2 3 4______________________________________Distilled water 35.35 37.35 38.35 38.35Dehydazol A 400 P 1.00 → → →Solbrol M 0.15 → → →Saccharin 0.10 → → →Sorbitol 40.00 → → →TiO.sub.2 RN 56 0.40 → → →Liquid paraffin 0.50 → → →Aromatic oil 0.50 → → →Texapon K 12 2.00 → → →Silica C 18.00 16.00 15.00 14.00Silica H 2.00 2.00 2.00 3.00Sum 100.00 → → →______________________________________ TABLE No. 12______________________________________Opaque dental-care compositions: Double function ofcleansing agents. Recipes contain pyrogenic silicahaving a thickening action.ResultsRecipe Abrasion Viscosity Assessment ofConsecutive No. pH mg of Cu mPa.s ribbon stability______________________________________1 5.4 10-11 2,420 Rating 22 5.2 9-10 2,170 Rating 33 5.4 9-10 1,800 Rating 34 5.0 8-10 2,728 Rating 1______________________________________ 6TH SERIES OF EXAMPLES This series of examples serves to show the superiority of the novel dental-care composition, in respect of shelf life, in comparison with the commercial toothpastes wherein the cleansing agents are based on silica xerogels, chalk and phosphate derivatives. The examples are intended to demonstrate the very important property of shelf life in respect of the variation of rheological properties with time (after-thickening is a phenomenon to be feared) and also in respect of the dependence of abrasiveness on time. The opaque and transparent toothpastes prepared for the storage tests, as well as the chalk and phosphate toothpastes considered for comparative purposes are shown, in respect of their composition, in Tables No. 13-No. 16. The results of the shelf life test, which extended over 12 months, are summarized, for all the systems investigated, in Tables No. 17-No. 20. TABLE No. 13______________________________________Opaque dental-care compositions (containing silica).Recipes for testing the shelf life. Consecutive No.Recipe 1 2 3 4 5 6______________________________________Distilled water 35.35 → → → → →Dehydazol A 400 P 1.00 → → → → →Solbrol M 0.15 → → → → →Saccharin 0.10 → → → → →Sorbitol 40.00 → → → → →TiO.sub.2 RN 56 0.40 → → → → →Liquid paraffin 0.50 → → → → →Aromatic oil 0.50 → → → → →Texapon K 12 2.00 → → → → →Silica A 10.00 -- -- -- -- --Silica B -- 10.00 -- -- -- --Silica C -- -- 10.00 -- -- --Silica D -- -- -- 10.00 -- --Silica E -- -- -- -- 10.00 --Silica F -- -- -- -- -- 10.00Silica G 10.00 → → → → →Sum: 100.00 → → → → →______________________________________ TABLE No. 14______________________________________Transparent dental-care compositions (containing silica).Recipes for testing the shelf life. Consecutive No.Recipe 1 2 3 4 5______________________________________Distilled water 12.95 → → → →Dehydazol A 400 P 0.50 → → → →Solbrol M-Na 0.15 → → → →0.5% dye solution 0.50 → → → →Saccharin-Na 0.10 → → → →Glycerol 60.00 → → → →Polyethylene glycol 400 3.50 → → → →Aromatic oil 1.00 → → → →Texapon K 12 1.30 → → → →Silica A 10.00 -- -- -- --Silica C -- 10.00 -- -- --Silica D -- -- 10.00 -- --Silica E -- -- -- 10.00 --Silica F -- -- -- -- 10.00Silica G 10.00 → → → →Sum 100.00 → → → →______________________________________ TABLE No. 15______________________________________Dental-care composition based on chalk.Recipe for testing the shelf life.Recipe Consecutive No. 1______________________________________Distilled water 41.05Dehydazol A 400 P 1.00Solbrol M 0.15Saccharin 0.25Glycerol 20.00Aromatic oil 1.75Texapon K 12 4.00Chalk 29.80Silica H 2.00Sum: 100.00______________________________________ TABLE No. 16______________________________________Dental-care composition based on dicalcium phosphatedihydrate. Recipe for testing the shelf lifeRecipe Consecutive No. 1______________________________________Distilled water 29.00Dehydazol A 400 P 0.80Solbrol M-Na 0.15Saccharin-Na 0.05Sorbitol 20.00Glycerol 5.00Aromatic oil 0.50Texapon K 12 2.00Dicalcium phosphate dihydrate (Dentphos) 41.00Silica H 1.50Sum: 100.00______________________________________ TABLE No. 17__________________________________________________________________________Opaque silica-containing dental-care composition. Shelf life resultsRecipeConsecutive Storage time:No. Properties immediate 1 month 3 months 6 months 9 months 12 months__________________________________________________________________________1 Abrasion (mg of Cu) 13 12 12 12 12 13 Viscosity (mPa.s) 10,100 9,600 10,300 10,500 10,750 10,9002 Abrasion (mg of Cu) 5 6 7 Viscosity (mPa.s) 12,240 11,850 10,5003 Abrasion (mg of Cu) 11 10 9 Viscosity (mPa.s) 11,016 10,890 10,2404 Abrasion (mg of Cu) 13 14 12 Viscosity (mPa.s) 9,180 9,220 10,1005 Abrasion (mg of Cu) 3 4 5 5 7 8 Viscosity (mPa.s) 9,400 6,800 5,500 4,800 3,950 2,8006 Abrasion (mg of Cu) 6 7 8 8 9 11 Viscosity (mPa.s) 8,600 7,100 6,500 5,800 3,500 2,170__________________________________________________________________________ TABLE No. 18__________________________________________________________________________Transparent silica-containing dental-care composition. Shelf liferesultsRecipeConsecutive Storage time:No. Properties immediate 1 month 3 months 6 months 9 months 12 months__________________________________________________________________________1 Abrasion (mg of Cu) 12 13 13 14 12 14 Viscosity (mPa.s) 10,000 9,800 9,500 10,200 10,500 10,1002 Abrasion (mg of Cu) 12 11 13 Viscosity (mPa.s) 12,900 12,500 11,5003 Abrasion (mg of Cu) 14 13 12 Viscosity (mPa.s) 11,300 10,800 11,2004 Abrasion (mg of Cu) 6 6 6 10 11 12 Viscosity (mPa.s) 9,800 7,800 7,500 4,900 3,900 2,8005 Abrasion (mg of Cu) 12 16 17 17 19 20 Viscosity (mPa.s) 9,800 8,500 6,300 4,700 2,950 2,300__________________________________________________________________________ TABLE No. 19__________________________________________________________________________Dental-care composition based on chalk. Shelf life resultsRecipeConsecutive Storage time:No. Properties immediate 1 month 3 months 6 months 9 months 12 months__________________________________________________________________________1 Abrasion (mg of Cu) 8 9 10 10 9 8 Viscosity (mPa.s) 6,450 6,800 4,200 4,500 3,900 3,600__________________________________________________________________________ TABLE No. 20__________________________________________________________________________Dental-care composition based on dicalcium phosphate dihydrate.Shelf life resultsRecipeConsecutive Storage time:No. Properties immediate 1 month 3 months 6 months 9 months 12 months__________________________________________________________________________1 Abrasion (mg of Cu) 3 3 4 3 2 3 Viscosity (mPa.s) 9,350 9,100 8,150 6,350 4,050 3,000__________________________________________________________________________ The following relationships can be demonstrated: The dental-care compositions according to the invention (see Table No. 17, recipes No. 1-No. 4 and Table No. 18, recipes No. 1-No. 3), which contain, respectively, cleansing agents A, B, C and D and cleansing agents A, C and D, surprisingly show an exceptional shelf life. This is true both of the abrasiveness and the vicosity characteristics in opaque and in transparent toothpastes. In practical terms, this result means that the abrasiveness determined at the final quality control of the product also applies after the product has been stored by the consumer, and that neither does the greatly feared after-thickening occur, causing the toothpaste to be unusable by the consumer, nor does diminishing viscosity cause the requisite ribbon stability to disappear and bring about the disliked phenomenon of separation. The dental-care compositions which are employed for comparison and which contain the commercial cleansing agents E and F, based on silica gel (see Table No. 17, recipe No. 5 and No. 6, and Table No. 18, recipe No. 4 and No. 5) show after one year's storage, both in the case of opaque and of transparent systems, a great increase in abrasiveness (80-165%!) and a great decrease in initial viscosity (down to 23%), which markedly lower the quality of these dental-care compositions. Accordingly, such compositions are not storage-stable over the chosen period of investigation. The dental-care compositions, also employed for comparative purposes, which contain chalk or dicalcium phosphate dihydrate as commercial cleansing agents (cf. Tables No. 19 and No. 20) admittedly retain their abrasiveness over a period of one year's storage, but in these systems again, a marked decrease of the initial viscosity is observed, this being somewhat more pronounced (down to 32%) in phosphate-containing pastes than in chalk-containing pastes (down to 56%). Accordingly, these dental-care compositions can also not be regarded as storage-stable over the chosen period of investigation. The patents and patent applications identified above are relied on and incorporated herein by reference.

A dental-care composition having improved shelf life in respect of rheology and abrasiveness, which as a novel feature, contains, as a cleansing agent, a bifunctional (thickening and abrasive) precipitated silica characterized by the following physico-chemical properties: ______________________________________ Pendulum roller mill Jet mill______________________________________BET surface area m 2 /g 15-110 15-110Tamped density g/l 150-750 90-650Secondary particle size FIG. 1 FIG. 2distribution according toCoulter Counter"ALPINE" screen % by <1.5 <0.1retainings > 63 μm weightCu abrasion in 10% mg 5-30 5-30strength glycerol disper-sionLightness value A % 86-96 90-96Viscosity in a 30% 30,000-60,000 30,000-60,000strength dispersion in a1:1 glycerol/watermixture, Brookfield RTV,Sp5______________________________________ The dental-care composition may additionally contain 0.5-5% by weight of polyethylene glycol or 2-14% by weight of a precipitated silica which in 15% strength dispersion in a glycerol/water mixture has a viscosity of not less than 30,000 mPa.s. Pyrogenic silica can also be employed successfully to regulate the viscosity of the product.

FIELD OF THE INVENTION [0001] The present invention relates generally to master input device configurations for interacting with computers and computerized systems, and more particularly to tactile glove configurations designed to measure contact between and among the fingers of the hand, and use that information as control input for computer systems. BACKGROUND [0002] Interacting with a computer may be challenging when an operator is moving in natural environments (e.g. walking, driving, fishing, etc.) and there is a need for improved solutions to this and other computer interface challenges. It would be valuable to have a more fluid interaction with the computer through tactile interactions among and between a user's fingers than is available today. In some scenarios, a view of a computer display is not always available. It would be valuable to have master input functionality in scenarios wherein an operator's hands are out of view (in pockets for instance). It would also be valuable to provide speed and efficiency in the computer interaction. Given the range and variation of motions typically encountered at the hand, the hand is a challenging mounting location for interface devices. [0003] Research on conductive and “smart” fabrics for human-computer-interaction (or “HCI”) goes back over a decade. In recent years it has become relatively easy to develop and experiment with different uses of the technology. Beyond the basic medium of conductive threads and fabric, the glove draws on two main areas of work: glove-based interaction and the use of proprioception in input devices. [0004] Dipietro et al. extensively survey the literature of glove-based interaction, including glove characteristics, application areas, and advantages/disadvantages. None of the 32 gloves surveyed has the combination of interaction properties of our glove; we believe that low-resolution spatial input by open-loop gestures is unique in glove-based interaction. The most similar device in the literature is the chording glove, which includes fingertip sensors and three discrete switches along the index finger. The input device taxonomy of Card et al. shows a scale for the resolution of input information via linear devices (e.g., the mouse), but almost all linear devices (excepting menus) provide “infinite” resolution in multiple dimensions (i.e., input that matches the high resolution of a display device). Ordinarily we would not see reduced resolution as an advantage in an input device. In the case of our glove, research in this direction is driven by two factors. First, low resolution facilitates a relatively natural interaction technique by exploiting proprioception. Second, conventional technology for high-resolution touch devices does not lend itself to this style of interaction, whereas low-resolution fabric-based technology does. [0005] Proprioception can be an important factor in non-spatial input (e.g., in touch typing) and in targeted movement tasks, in both the directional component (e.g., movement of a joystick in one of the cardinal directions) and the distance component. Proprioception has been applied directly in the development of some input techniques, though to different ends than with our glove. Mine et al. describe a framework for virtual reality systems in which a number of proprioception-based interaction techniques are introduced. De Boeck et al., also working in virtual reality, describe techniques for analyzing the integration of proprioceptive cues into a multimodal interaction. These techniques apply at the arm and body-scale, and they are not associated with tactile or haptic feedback. [0006] A few projects described in the HCI literature are similar in spirit to our own, though they differ significantly in focus and scope. For example, Olwal et al. demonstrate the promise of rubbing and tapping gestures for precise selection tasks on mobile devices. Li et al.'s “SoundTouch” supports vibrotactile interaction in the form of taps and rubs, but for output rather than input. In addition to performance findings, Li et al. report that subjects find the sensations from the device to be similar to touches from other humans. Ni and Baudisch describe the evolution of mobile devices toward disappearance via miniaturization. They evaluate the use of touch and motion scanners for character entry and marking tasks. Some categories of user errors they observed, dealing with device alignment and detection range, may be reduced in our glove, though the glove may have other limitations. [0007] There is also a long history of gloves for automated recognition of sign language (Ong and Ranganath give a relatively recent partial survey). SUMMARY [0008] One embodiment is directed to a system for human-computer interface, comprising: an input device configured to provide two or more dimensions of operational input to a processor based at least in part upon a rubbing contact pattern between two or more digits of the same human hand that is interpreted by the input device. The input device may be configured to provide two orthogonal dimensions of operational input pertinent to a three-dimensional virtual environment presented, at least in part, by the processor. The input device may be configured to detect the rubbing between a specific digit in a pen-like function against one or more other digits. The input device further may be configured to detect the rubbing between the specific digit in a pen-like function and one or more other digits in a receiving panel function. The input device may be configured to detect the rubbing between a thumb of an operator in a pen-like function against one or more other digits. The input device may be configured to detect the rubbing between a thumb of an operator in a pen-like function against an index finger of the same hand of the operator. The input device may be configured to detect the rubbing between a thumb of an operator in a pen-like function against adjacently-positioned index and middle fingers of the same hand of the operator. The input device may comprise a tactile-sensitive glove. The tactile-sensitive glove may comprise two or more conductive portions that are operatively coupled to the processor. A displayed version of the three-dimensional virtual environment may be rendered by a video device operatively coupled to the processor. BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIGS. 1A-1D illustrate images of a glove master input device variation in four different command configurations. [0010] FIG. 2 illustrates robot views in a simulated or virtual 3-D environment. [0011] FIG. 3 illustrates various circuits actuated by a thumb on a variation of the subject glove. [0012] FIG. 4 illustrates a three-state model for a variation of the subject glove. [0013] FIG. 5 illustrates a target selection configuration in one and two dimensions. [0014] FIG. 6 illustrates a plot of task 1 a/b selection duration, per target size ratio. [0015] FIG. 7 illustrates a plot of task 1 a/b success frequency, per target size ratio. [0016] FIG. 8 illustrates a plot of task 3b tap interval, per finger. [0017] FIG. 9 illustrates a plot of task 3b success frequency, per finger. [0018] FIG. 10 illustrates a table of symbol rub gestures. [0019] FIG. 11 illustrates a plot of task 4 duration and success frequency, per participant in an experiment. [0020] FIG. 12 illustrates a sample view of head-mounted display in “flyer” view during “manual fly” mode. [0021] FIG. 13 illustrates an outline of an interaction scenario in accordance with one variation of the subject glove. [0022] FIG. 14 illustrates one glove data structure configuration. [0023] FIGS. 15A-15F illustrate, respectively: an original image of noisy glove data ( FIG. 15A ); an up-sampled image using bi-linear interpolation ( FIG. 15B ); proper close ( FIG. 15C ); local average smoothing ( FIG. 15D ); exponential lookup table ( FIG. 15E ); and energy centroid computed ( FIG. 15F ). [0024] FIG. 16 illustrates one variation of a basic command flow. [0025] FIG. 17 illustrates one variation of a “main augmented reality view”. [0026] FIG. 18 illustrates one variation of a crawler view showing a highlighted slider to the center left of the illustration. DETAILED DESCRIPTION [0027] What is presented herein are various glove-based master input device configurations, wherein, amongst other factors, the glove differs from prior gloves because it explicitly measures the tactile interaction amongst and between the fingers of the associated human hand. Associated design and evaluation has been conducted with a glove instrumented with conductive threads and fabric. The glove contains large individual sensors covering the tips of the thumb, third, and fourth fingers; grids of smaller sensors line the palmar sides of the first and second fingers. The sensors of the first through fourth fingers are activated by contact with the thumb. Two types of gestures are supported: a touch contact between the thumb and the other fingers, and is fibbing gesture of the thumb on the first or second linger, or both together. Conceptually, the glove may be thought of as a low-resolution trackpad plus four buttons, all used by the thumb. FIGS. 1A-1D illustrate one glove configuration and various gestures it supports. [0028] The glove shares some interaction properties with some other glove-based input techniques. No object is held in the hand, which facilitates switching to other kinds of tasks that require use of the hand, allowing for the physical dexterity constraints any glove imposes. Based on the taxonomic criteria of Dipietro et al., the glove can be described as follows: it relies on 1 cloth-supported discrete sensor on each of three fingers and >1 discrete sensors on two fingers, with 1-bit precision per sensor, and it is a tethered device (wireless is feasible but not currently implemented), communicating over a USB interface. The glove supports multiple-finger, surface-free input. [0029] The glove integrates different interaction techniques in a novel way. First, input methods, including those associated with most types of gloves, are typically categorized as being continuous or discrete, with continuous input being used for spatial information in one, two, or three dimensions and discrete input for symbolic commands or characters. This distinction is not driven by physical or logical properties of interaction, but there are few common examples of linear input devices with an explicitly limited resolution used in computing today (e.g., such as a ratcheted physical slider). The glove provides spatial input, but at a much lower resolution than is typically associated with continuous input devices, and the sensors it relies on am simple discrete switches. Second, the glove exploits this low resolution input by allowing users to take advantage of proprioception, their implicit knowledge of locations on the fingers that can be touched by the thumb. Third, these touching actions are open-loop gestures that can be used for spatial targeting, which in most other input devices is supported by closed-loop gestures (e.g., targeting actions associated with pointer movements). These three interaction properties are not unique in isolation, but to our knowledge they have not been combined in a single input device. [0030] The inventive glove consists of a set of digital and analog data channels in a combination of conductive thread and wire. The glove can be thought of as a set of switches, each of which completes a circuit through a variable resistor, which is an individual conductive thread. A switch is closed when the thumb makes contact with any thread. Current may be supplied by a model USB-6009 device supplied by National Instruments, Inc. [0031] The grid, divided into two even pans over the first and second fingers, provides 80 sensed locations in all: four threads running the length of each finger (the y threads), ten across the width (the x threads). The threads may be sewn in a crosshatch pattern on and below the surface of the glove fabric such that the threads do not touch each other, in particular at crossing points in the r and y dimensions. When the thumb touches the grid, it contacts at least one X and one p thread, closing those circuits. Each such event generates a bounding box (or a single point) on the grid, from which the center and the size of the box can he extracted, as shown in FIG. 3 . [0032] If the bounding box covers an odd number of grid lines in a given dimension, the center of the box corresponds to the center grid line in that dimension, if the bounding box covers an even number of grid lines, however, a point between the two center lines is used. This gives the grid an effective resolution of almost quadruple the number of its sensed locations with the qualifier being due to locations on the boundaries). This provides the intuition behind the glove's input processing. The actual implementation treats the grid as pixels of an image. Through multiple steps involving super resolution, look-up tables, and morphological reductions, the energy center of the touch “image” is extracted. These steps significantly reduce the noise inherent to the thumb/finger contact point, leverage the fact that the thumb contact area is usually quite large, and guarantee a single grid coordinate as the output value. This last point is notable as the grid intrinsically facilitates multi-touch interactions similar to those normally found in modern touch screens, but because the thumb is the only contact point with the grid, a single output is desirable. [0033] At an abstract level, the glove can be compared with other input devices in the form of a three-state model, as shown in FIG. 4 . The size of the bounding box can be treated as further input, but we have not explored the use of this extra information in our work to date. [0034] Implementation Example—Virtual Environment Simulation #1: [0035] One initial goal for the development of a suitable master input device glove was to support flexible one-handed interaction with a synthetic as might be provided in an augmented reality system ( FIG. 2 illustrates robot views in a simulated or virtual 3-D environment), while the user is walking and looking around through a head-mounted display (“HMD”). We have developed a simulation of such an application using a video game engine. The simulation comprises two semi-autonomous robots (a “crawler” and a “flyer”) that follow pre-programmed paths through a simulated rain forest environment. Each robot pipes its video feed and other status information to the user. The user can take control of either machine at any time to direct its actions using buttons, menus, and navigational controls. [0036] The simulation may be operated using the glove as a master input device via different types of gestures: Some global commands are mapped to taps on fingertips: a single tap on one or more fingers, or repeated taps on one or more fingers. The may be referred to as a “tap” Some local or context-sensitive commands may be mapped to directional rubbing gestures, single strokes on the first or second finger, or across both. These can act as shortcuts to execute a command or change state in the interface (a “symbol rub” gesture). Advancing down linear menus, a spatial command in one dimension may be mapped to a rubbing gesture on the first finger (a “scroll gesture”). This is distinguished from symbol rub gestures in that it involves targeting by distance as well as direction (scanning with the camera also may be implemented with this gesture in a different configuration) Continuous, dynamic directions in two dimensions, analogous to the output of a joystick, are supported by rubbing over the first two fingers (a “2D rub gesture”). An analogous use of this gesture in the application is for choosing from a pie menu. [0041] These gestures can be seen in a sample scenario in the simulation, in which the user responds to a call from the crawler that is stuck and needs assistance. The user executes the following steps, with the category of the relevant gesture that is bracketed. 1. Bring up a standard view on the HMD, including a diagnostic window. [Tap]. 2. Switch to the crawler's control interface. [Tap]. 3. Shift focus to the “Behaviors” menu. [2D rub]. 4. Enter the “Behaviors” menu. [Tap]. 5. Move through the items to highlight the “Manual” behavior. [Scroll]. 6. Select the behavior. [Tap]. 7. Switch focus to the “Drive” control. [2D rub]. 8. Start manual drive. [Tap]. 9. Drive the crawler until it is free. [2D rub]. [0051] Formative usability tests were conducted with six users. Each session began with a demonstration to show the different interaction options the glove supports. Within five minutes all users were reasonably competent in the interface, the only consistent challenge being the difficulty of remembering the mapping of different gestures to commands. Qualitative feedback was positive: Users found some kinds of gestures intuitive and enjoyable, in particular control of the movement of the robots by rubbing gestures. [0052] A few initial lessons came to light during the formative evaluation. One is the potential difficulty for novice users to learn the mapping of gestures to commands in cases where there is no intuitively obvious choice, such as changing modes by tapping all fingers at once, (This was gesture was used to avoid accidental mode changes.) Another is the value of designing the layout of the interface such that, in specific modes, interface components can be selected by a short directional rub. This raises the issue, however, of whether strongly modal interfaces would be appropriate in other task domains. [0053] The glove generally met our expectations in the application. It appears to show promise in offering an effective way to control a specific simulation, with some commands and continuous actions naturally mapping to the gestures supported by the device. [0054] We carried out an informal evaluation to test the performance characteristics of the glove in tasks for which we expect it to be well suited. Our interest is in the following: Target selection. Consider a scenario comparable to the one described in the previous section, in which the user would like to select a target region of a pre-specified size, perhaps indicated on a head-mourned display, using the glove. How accurately can the user perform such an action, either without visual feedback for the action or with adjustment based on feedback? Fingertip tapping gestures. The glove supports discrete, non-spatial actions in the form of tapping the thumb to different fingers. How quickly and accurately can users carry out such actions. Directional rubbing gestures for symbolic input. Directional rubbing gestures on the glove can interpreted as discrete symbols. How quickly and accurately can users cant' out sequences of such actions. [0058] The goal of our evaluation was to develop a set of quantitative performance benchmarks for the use of the glove under laboratory conditions, mainly in the form of descriptive statistics. [0059] Tasks were designed to answer the questions above, and a testing environment was created for each, with parameters selected based on a pilot study with the one of the authors acting as a participant. [0060] We discovered that we had underestimated the noisiness of the prototype as an input device, due to its physical construction, its sensor limitations, and our input processing techniques. For example, the glove must be positioned appropriately on the fingers to function properly, and it does not fit all hands. In use, the glove sometimes registers spurious contact/release events, and one or two threads on the glove occasionally miss input, due to bending strain on the connections. These issues play a role in limiting performance in all the tasks described below. [0061] We carried out an experiment involving four tasks, with 11 participants, all unpaid volunteers. Participants ranged in age from 21 to 33. Two were female, nine male. All were right-handed, with vision corrected to 20/20, and use computers daily. The total duration for a session was about 30 minutes per participant. Each participant first put on a non-latex insulating glove and then the haptic glove. Tasks were carried out in the same order for all participants. Between tasks, participants were allowed to rest for up to two minutes. [0062] Tasks 1a and 1b: Indicating spatial location (Part 1). Task 1 was a target selection task in one (Task 1a) or two (Task 1b) dimensions. Task 1a was performed before Task 1b. Participants were shown a box containing a colored target region, as in FIG. 5 . [0063] The spatial extent of the box is mapped in absolute terms to the layout of sensors on the first two fingers of the glove. In Task 1a, vertical movement is ignored. The box is divided into an array of n×1 elements for Task 1a or n×n elements for Task 1b (the resolution), and the target occupies adjacent elements for Task 1a, s×s elements for Task 1b (the relative target size). These divisions are not visible in the display. The specific values used for n and s are given in Table 1. based on our judgments about the difficulty of the task from the pilot study. [0064] Note that n=30 is an interesting challenge for the glove, which works at a resolution of at most 10 discrete sensor locations in one dimension. Unlike mouse interactions, the mapping from the input space to the output space is one-to-one and onto. That is, we are asking participants to control a space with a higher resolution than that of the input device. [0000] TABLE 1 Resolution (n), target size (s), and target size ratio. n s Ratio 9 2 1.22 9 4 0.44 30 2 0.06 30 4 0.13 30 8 0.26 [0065] For Task 1a and then for Task 1b, the participant carried out 24 trials in a training phase. Participants then carried out 10 trials for each of the conditions in Table 1, with target locations generated at random by the system. A trial began with the participant's thumb moving freely, not in contact with the sensors on the fingers. A target appeared in a random location, and the participant touched the thumb to the fingers, causing a cursor to appear. The participant's goal was for the cursor to overlap the target. If this did not happen on the initial touch, the participant slid the cursor by rubbing with the thumb until the target was reached. The participant released contact with the thumb to indicate completion of the trial, and the next trial began immediately. For each trial, the duration was recorded between the release event at the end of one trial and the release event of the next trial; the time for a new target to appear was considered negligible. A trial was considered successful if the release event occurred with the cursor over the target. [0066] Some data cleaning was performed to remove outliers with durations longer than 10 seconds (less than 1% of the data. Task 1a, less than 2% of the data for Task 1b). Qualitatively, the results were largely as expected. FIG. 6 shows the change in duration of target selection as the target size rain increases. FIG. 7 shows the frequency of successful completion of a trial. [0067] Over all the conditions in Task 1a, the mean duration for target selection was 1326 milliseconds. The fastest condition was a resolution of 9 and a target size of 4 (for a target size ratio of 0.444), with a mean duration of 953 milliseconds. The most successful condition was also 9/4, with a success frequency of 0.82, The lowest success frequency by an individual participant was 0.071, in condition 30 1 2: no participant reached a frequency higher than 0.50 for that condition. The highest success frequency by an individual participant was 1.0, reached by seven participants in various conditions (9/4, 30/8, and 30/4). [0068] Task 1b values are comparable: the overall mean was 1562 milliseconds, the best condition (9/4) at 934 milliseconds, with the success frequencies being 0.56 and 0.79, respectively. Eight participants were unable to score higher than 0 in the 30/2 condition; four participants reached a score of 1.0 in the 9/4 condition. [0069] For context, Parbi at al. give duration results for selection of targets on small touchscreens with the thumb, in one-handed use. For targets of average size on small touch screens, selection time is between 1100 and 1200 milliseconds; errors appear in almost 30% of selections. The tasks in their experiments are significantly different from Tasks 1a and 1b, but the comparable timing and error rates (e.g., for the midpoint in FIGS. 6 and 7 ) suggest that glove interaction is not unreasonably slow. The low success rate of 0.82 for even the best target size ratio, however, is more problematic. As mentioned above, this is attributable to two factors: a high level of noise in the sensing for the glove (ie., spurious release events detected), and the limitations the glove imposes on fine targeting actions. [0070] Task 2: indicating spatial location (Part 2). Task. 2 was designed to test whether Fitts Law applies to the selection of targets only using rubbing gestures, patterned after MacKenzie and Buxton's study of two-dimensional pointing tasks. The structure of the task was similar to that of Tasks 1a and 1b, with the display functioning as a slider widget. Participants first acquired the indicator of the slider and then, by a rubbing action, dragged in to a specified target location, again releasing the thumb at the end of each trial. Unfortunately, this proved unexpectedly difficult for two reasons. Some of the target locations were so close to the boundaries of the device that they could not be reached with a continuous rubbing action, and the initial acquisition of the slider indicator proved more difficult than we had anticipated. For more than half of the participants, the task quickly became so frustrating that they gave up. [0071] We do not report results for this task; however, its failure under experimental conditions suggests the limtations of the device. The current design, in which input and output are decoupled with respect to resolution and a confirmation action simply involves release of the thumb, is inadequate for interaction with. conventional graphical user interfaces. Obvious solutions include confirmation actions that are separate from movement, as in the simulation application of the previous section, but new in techniques may be needed. Qualitatively satisfactory results in the robot application, where pie menus and taps were used extensively, indicate those modes of interaction better leverage of the device's capability, as contrasted with the poor performance for other types of pointing operations. [0072] Tasks 3a, and 3b: Providing discrete input with finger taps, Task 3a involved participants “playing the scales” on their fingers. After a practice phase of 24 trials, participants executed 50 trials, tapping the first through fourth finger in order, then in reverse order. Only duration was measured for these trials, from one release event to the next. The mean duration per tap was 305 milliseconds. [0073] Task 3b required participants to watch the computer display and follow instructions for which finger to tap. Instructions were presented visually, in the form of four colored squares in a vertical column, each corresponding to a different finger. A trial consisted of one square turning a different color and the participant tapping the appropriate finger. The next trial began immediately thereafter. An error was counted if a participant touched a finger other than the one shown on the display; the participant would repeat the trial with the correct gesture. In a practice phase, participants executed 24 trials using the interface, and then carried out SO trials for the task, in which the finger to tap was determined randomly. Duration and success (correct taps) were recorded. [0074] Two outlier trials were removed before the analysis was carried out. FIGS. 8 and 9 show the duration and success frequency per finger. The mean over all fingers was 575 milliseconds, with a success frequency of 0.93. The higher duration and lower accuracy of tapping the first finger (The index finger) goes against expectations; we believe it should be attributed to the glove hardware and input processing. These durations are in the expected range for the glove, comparable to performance on the chording glove, though error rates appear to be higher. [0075] Task 4: Providing discrete input with directional rubbing. Task 4 is a gesture entry task, analogous to text entry tasks in which participants enter gestures using an input device, following a sequence provided on a computer display. All gestures in Task 4 are symbol rubs, as described above, single strokes in a diagonal direction. A sampling is shown in FIG. 10 . The direction of the line segment indicates the direction of the gesture, and the red dot indicates the starting point. The upper box indicates a symbol rub on the first finger, the lower box on the second finger; a tall vertical box indicates a symbol rub across across both fingers. (Note that in this task, participants are not asked to remember the mapping of gestures to symbols, which means that timing and errors are due to the text copying process rather than memory.) [0076] A set of trials begin when the participant tapped the thumb to the fourth finger; participants carried out the sequence of gestures displayed. A blue cursor advances through the displayed gestures as they are carried out. On reaching the end of a sequence, participants tapped the fourth finger to advance to the next sequence. [0077] Participants carried out 24 trials to practice the gestures. During the practice phase, a simple gesture recognition system provided visual guidance as to the accuracy of the executed gesture. Gesture recognition was turned off for the trials that followed, because we believed that this would provide for more realistic estimates of the speed at gesture entry in practice, and because of the unreliability of input processing. After the practice phase, participants, carried out 50 gestures, following a randomizer sequence,broken up into sets of 8, as shown in FIG. 10 . [0078] The mean duration of a gesture in Task 4 was 364 milliseconds, and the success frequency (i.e., recognition rate) was just 0.40. The relationship between duration and recognition rate is show in FIG. 11 . The lowest success frequencies per participant (0.02, 0.06. and 0.08) are associated with gesture durations of 200 milliseconds or less. The highest success frequency, 0.94 for one participant, was associated with a mean duration of 614 milliseconds per gesture. The mean 40% recognition rate is clearly far too low for practical use of the glove in this task. Based on our observations of the tests, it seems possible the low recognition rate may be partially due to the horizontal data lines that intermittently fail; noise in the form of spurious release events also played a role. A less noisy glove my improve results. [0079] Contrary to our expectations, performance for target selection (Tasks 1a and 1b) and symbol input (Task 4) was surprisingly low. Worse, a mouse-style pointing task had such low performance that the task could not be completed. We partly attribute this to the glove's noisy capture of the user input. [0080] Despite the disappointing overall results of our experiment, we find a few bright spots: a few participants, in a few tasks, achieved reasonable performance. The authors of this paper, with more experience using the glove, significantly outperform the best of the participants in the experiment: as in other glove-based work, training plays a factor in performance. [0081] The simulated robot application, in contrast, worked much better. Failed inputs had low cost-actions could be repeated- and and users found navigating to icons using a pie-menu interaction, action, menu selections with 1D scrolling, driving and flying the robots with joystick interactions, and shifting interface modes or confirming selection with taps, to all be highly effective, easy to learn, and not frustrating. This suggests that gloves that use a “touchpad on the finger” may have relevance for specific application domains and interaction styles, in particular those relevant to interaction when the user's hand might be out of view. We believe that with better hardware, the glove should offer an interesting new avenue for interaction in wearable computing. [0082] Other related variations may include the following: Alternative sensing technology for the glove, such as circuitry printed on the fabric of the glove or fabric-based rheostats. Refinements based upon Human performance experiments. For example, by estimating the number of distinct locations users can distinguish when tapping or rubbing along the length of their fingers, the system may be optimized. Task 1 offers no more than a rough approximation of the ability to select different targets. Expansion of the gesture set for symbol rubs, such as for text entry by glove gestures. In one variation the system is configured to carry out distinct, single-stroke gestures with the thumb on the surface of the first two fingers without wearing a glove. Such easy, natural movements may be brought to glove-based interaction. Enhanced expressiveness in HCI by virtue of the use of the hand in concert with the glove, such as in a variation wherein a glove master input device is utilized to generate music, such as by a hand-held harmonica instrument. [0087] Implementation Example—Virtual Environment Simulation #2: [0088] The goal of one implementation is the design and prototype of a human-centric user interface for a team of semiautonomous robots. The system uses the subject hand-worn, tactile-gesture input device, with feedback and system state provided to the user through a heads-mounted display (HMD). [0089] Data entry into electronic devices during walking or other activities is quite difficult with current interfaces (cell phones, laptops, and tablets). One primary motivation for the subject glove-based master input device configuration was to produce a one-handed device capable of interacting with a synthetic display while its user is walking, looking around, or otherwise engaged. For a multi-robot scenario, one logical choice of display device is a head mounted display (HMD). Many such devices exist, but none to the specifications suggested by the storyline described below, and for this reason, we simulate the graphics that would appear in a HMD using a video game engine and a custom software program implemented in LabView (RTM), available from National Instruments, Inc. [0090] One main input to this system is a hand-worn controller which enables tactile interaction with the system interface and is capable of capturing various user input gestures, which act as commands to our system's interface. The glove consists of 2D digital data channels connected by a combination of conductive threads and wires. A digital to analog converter (DAC) is then used to capture the digital input. The display consists of “live” video feeds from a set of robots—a “Crawler” and a “Flyer”, robot functions, and maps showing the location and sensor data of the robots in the three-dimensional virtual environment. [0091] We have fabricated the hand controller using a glove, with sewn-in electrical contacts using conductive wires to facilitate the capture of user gestures. Drivers written in LabVIEW (RTM) allow us to transform the hand motions into commands to the system. For this sample implementation, we chose to simulate the environment and robots using the Unity game engine. The display handles multiple video streams, and allow the user to manipulate/move them as well send commands to his/her robot swarm via hand controls parsed by LabVIEW. [0092] Due to reliability and communications issues associated with modern robots, multi-robot controllers currently available on the market are focused heavily on reporting of status and collection of data rather than the interaction between the user and his/her swarm of robots. This also requires them to be run primarily on large displays or laptops connected to large radios or other communication devices. For our design we have attempted to create an ideal interface for a user in the field to be able to control multiple robots while still moving freely and focusing on other tasks. [0093] The inventive glove differs from other known glove-interaction devices, none of which combine the range of interactions described below or incorporate a 2D touchpad as the subject glove system does. Using the subject glove-based interface, our multi-robot controller will differ from others on the market in its ability to be worn, its ability to be controlled via finger gestures, and its ability to utilize a HMD as its primary display. [0094] Current multi-robot controllers are laptop based and are focused on communication and status rather than user interaction. Hence, we emphasize on following goals: Allow a user to utilize multiple robots efficiently and effectively while still participating in other tasks. Design an interface that allows a user approximately 90% of his or her time for daily activities, with instant context shifting to “conduct” the activities of a collection of robots in the other approximately 10% of his or her time. [0097] To accomplish the above said goals, the subject interface is configured to be worn as eyeglasses and a glove. In one configuration, there are three components to the interface: a head mounted display (HMD), a glove that senses touch between multiple fingers, and a software package that displays information from robots. The robots are themselves simulated in a virtual computer game world. One is a “flyer” the other is a “crawler.” Both have simple behaviors common to commercial/military robots, though our main focus in this example is not the behavior of the robots but the interaction of the user controlling them. [0098] In practice, the user wears the HMD, which is functionally transparent to the user most of the time. When a robot needs help, the HMD may be configured to play the robot's voice calling for help. The glove may be configured to capture aspects of a user hand motion, and specific gestures bring up information on the HMD. The HMD can operate in “augmented reality mode” (overlaying transparent objects on the user's view of the world), or in “opaque mode”, where it shuts out the real world and displays computer generated data, video streams from the flyer and crawler, etc. The simulated display using Unity game engine and LabVIEW is the main interface of our system in this example. [0099] FIG. 12 illustrates a sample view of a head mounted display (“HMD”) in a “flyer” view during a manual “fly” mode. [0100] The glove is a unique part of the interface configuration. Other gloves designed for master input device functionality gather input from either bend sensors or discrete buttons, both of which are deficient for many real-world applications. The subject glove incorporates/improves the functionality of these devices, and has a 2D grid on the index and middle finger that acts as a touch pad. The grid may comprise conductive threads that connect to a data acquisition card. The thumb may be covered in conductive fabric which is grounded: when it touches the threads, a circuit is completed. As the threads do not touch each other, the two-dimensional extent of the thumb's touch may be captured by reading the horizontal and vertical threads, and composing them into a matrix. [0101] The glove uses various different gestures to capture user inputs, such as one-finger clicks—touch, single clicks, double clicks, triple clicks, etc. [0102] In one variation, solid patches of the glove may be made of conductive cloth, with the thumb attached to a ground. By touching a finger to the thumb, a circuit is closed and our system registers a touch by a specific finger. In addition to this functionality, the system also registers double/triple touches. [0103] In addition to single finger clicks, the subject system may be configured to detect multi-finger clicks. In addition to the 4-finger click shown in FIG. 1D , the system may be configured to detect any combination of the 4 fingers touching the thumb. [0104] The inventive glove features a 1-dimensional touchpad along the index and middle finger in one variation, and may be configured to function as a two-dimensional touchpad when the index and third fingers are held together, as shown in FIG. 1B . In such variation, the grid itself may comprise 10×8 threads, but as is described in further detail below, by utilizing techniques common in computer vision, we are able to greatly increase the accuracy and resolution. [0105] Given an established and acceptable variety of inputs, we have focused on how to use them to produce usable, intuitive interactions. Due to the vast number of possible interactions supported by the subject glove, it may be important to try and limit supported interactions to only the most intuitive/important for a chosen task domain. Such interactions may then be refined through various techniques such as paper prototyping and/or personas (discussed in more detail below). [0106] For the single and multi-finger touches, in one variation we may choose to interpret them as clicks of a button, allowing the user to select items or trigger transition switches. For consistency, in one variation we have attempted to use the ring finger to serve as the select/confirm input for all selections and dialogs, while the pinky finger serves as the cancel/back input. We also have mapped a 4 finger touch as the action to return an operator to a “home” configuration from any state in the system. [0107] A one-dimensional touchpad configuration lends itself naturally to actions in the user interface such as scrolling lists, adjusting sliders, and panning a camera one plane, and such implementations are utilized in one variation of the system. The two-dimensional touchpad configuration may require more careful design and consideration of what actions should be supported. One considered task was how to select content on the screen. In one variation, one option discarded after paper prototyping was to utilize the touchpad as it is used on laptop, and simply have users control a pointer to select items. While easily implementable with our architecture, such configuration may not improve on the existing laptop model of control, and may not provide the type of intuitive interaction that is a design objective. In one configuration it has been decided to model the HMD as a large pie/radial menu. Instead of controlling a cursor, the user must simply move his/her thumb toward the region of the screen that houses the desired item. To provide feedback and avoid unintended selections, the system may be configured to highlight the selected object, and the user may confirm the selection with a simple click of the ring finger. [0108] In one variation, another interaction objective is to utilize the 2D touchpad as a joystick. To accomplish this a small “deadzone” may be created around where the thumb contacts the grid, and modes may be created to allow the user to fly or drive the robots. In both cases, with experimental subjects operating the system, every user has adapted to this functionality immediately and had no problems driving/flying within seconds. [0109] A sample operational script utilizing such configuration is described below and featured in FIG. 13 : 1. Audio queue, “Crawler: I am stuck, please assist.” 2. User taps tips of all fingers together to bring up augmented reality view. 3. A diagnostic window appears, semi-transparent in upper corner of HMD (head mounted display), giving a brief status overview, 4. Three taps on ring finger transition HMD to opaque, and shows the crawlers control interface 5. A down-and-left stroke of the thumb on the index and middle finger focus the “Behaviors” box. 6. A tap of the thumb and ring finger enter the behaviors box. 7. Sliding the thumb across the index finger, the user scrolls to the “manual drive” behavior. 8. A tap of thumb and little finger pops out of the behaviors box, putting the robot in the just-selected behavior. 9. An up-and-left stroke of thumb against index and middle finger highlights the drive button. 10. A tap of thumb and ring finger starts manual drive. 11. The thumb's motion on the 2D touchpad formed by the index and middle fingers acts as a joystick, driving the robot. 12. When robot is “unstuck,” user performs repeats the above steps to put the crawler into a behavior, then taps all the tips of fingers together twice to return to augmented reality mode, and turn off the HMD. [0122] The above may seem like a large number of steps, but they can all be executed in mere seconds, because fingers are quite dexterous when interacting with each other, there are no manual pointing operations, and the user never has to look at his hands. [0123] In terms of software design and implementation in this second exemplary configuration, the 2D touch surface and the individual contacts on the ring and little finger are the only physical parameters brought into the computer, however in software several other data elements are derived. FIG. 14 shows a representation of the data structure the glove software populates. The boxes titled “(1)”-“(4)” are Boolean touch values for the index, middle, ring, and little finger respectively. Each can have a simple touch (“tch”), or single-tap (“st”), double-tap (“dt”), or triple-tap (“tp”). (A traditional mouse click is equivalent to this single tap.) The “1d” object holds 1D (i.e., one-dimensional) x-values indicating the thumb's position along either the index (“(1).x”) or middle (“(2).x”) finger. The “2d” object is the two-dimensional touchpad mentioned earlier. The “vec” object is a vector of thumb motion: when the thumb first contacts the 2D grid, its position is recorded. As long as the thumb remains in contact with the finger, the thumb's position is calculated as a vector (magnitude “r” and direction “theta”) relative to the initial point. This facilitates relative pointing operations. [0124] There are many gloves that implement a form of button presses and taps. One key unique feature of our glove is the 2D touchpad interface on the index and middle fingers. Although the implementation of this touchpad might seem to be error prone (because it is constructed of conductive threads that fray and can short on each other), in actual operation the touchpad is quite robust because of the processing the glove's raw data receives before being sent on. [0125] In one variation thumb position is extracted using an imaging algorithm configured to treat the 8×10 grid of conductive wires as image plane, where each intersection of row and column corresponds to a pixel. Creating the image is a matter of populating a 2D grid, where pixel(i,j)=row(i) AND column(j) (where row( )and column( )are Boolean arrays of raw input). The algorithm determines the location of thumb by first removing noise from this “touch image” with a set of filters, then finds the energy centroid of the resultant image. Because imaging filters tend to work best on source data that is smoothly varying, the original 8×10 image is up-sampled using bi-linear interpolation to a 32×32 image. An example of the process from binary image to final centroid is shown in FIGS. 15A-15F . [0126] The steps of the imaging algorithm may be chosen using a heuristics-based algorithm-development method. First, a set of representative images—including significant outliers—may be collected, then using a toolbox of image processing functions, the algorithm designer may select a sequence of functions based on his observations of their effect on the image. The choice of which functions to apply from the hundreds available may be based on designer's experience and intuition. National Instruments Vision Assistant software may be utilized to assist this process in a graphical manner. In one variation, the specific functional steps finalized for this project are given below with their reason for inclusion. 1. Create input image format from binary 10×8, 2D, Boolean array: enables processing using imaging tools. 2. Up-sample using bi-linear interpolation to 32×32 pixel image: puts smooth edges on all regions in the image. 3. Proper-close: removes small noise elements from image without destroying smoothed edges. 4. Local-average filter with a 7×7 kernel (all ones with a zero center element): ramps all gray-scale values in the image, leaving brightest regions in the center of large regions. 5. Exponential look-up table: changes the dynamic range of the image accentuating only the brightest regions. 6. Find the energy centroid of the whole image: this simple method captures the most likely point of user thump contact with the 2D array. [0133] There are dozens of alternate algorithms for establishing where a user's thumb contacts a surface; the above nonlimiting example simply is one that has been implemented with success. Note that the configuration is specifically designed for finding a single point of contact (others are filtered out, as we consider them to be noise). This is of course a software constraint, if the hardware is modified to remove potential short circuits, this algorithm's complexity may be reduced, and simultaneously support multi-touch interactions. [0134] The raw data from the glove may be interpreted into a data structure. An internal triggering structure may monitor the data structure for changes, and push any changes to an event queue. When an event is received, the system may then parse the relevant aspects of the data structure based on the mode of operation and perform the appropriate action. For example, in one variation, if the user is in the main view, the only acceptable commands are a 4 finger touch and a triple tap on either the ring or pinky finger. Although the 20 movement is captured, it does not affect the state of the interface since the command has no meaning in this context. [0135] FIG. 16 illustrates one variation of a basic command flow. [0136] In one variation, the system supports multiple modes of operation, with different gestures accepted as input: A base MAD view has 3 accepted commands. First, the user may toggle the basic “health monitor” plays with a 4 finger touch. A user may also transition to the crawler and flyer views with a triple touch of the ring finger for crawler view, and the little finger for flyer view. FIG. 17 illustrates one variation of a main augmented reality view. A crawler and flyer view overlay a significant amount of information on the screen. The user can select the various control widgets by gesturing with their thumb to the segment of the screen where the widget is located. The currently selected widget is highlighted in green, so that the user has feedback as to which widget they are highlighting. Once the appropriate one is highlighted, the ring and little finger allow the user to enter/exit the widget. FIG. 18 illustrates one variation of a crawler view showing a highlighted slider to the center left of the illustration. [0139] With such configuration, if the user selects the behavior menu or slider, they can scroll through the various values by moving their thumb along the length of their index finger. For driving the vehicles, the user utilizes their thumb on the 2D touchpad as a joystick. To return to the main HMD view, the user simply uses a 4-finger touch. [0140] To interface between a LabVIEW (RTM) controller and a Unity (RTM) game object, an instance of the Unity web player may be embedded into the LabVIEW interface. To communicate between the two, various inputs from the glove may be mapped to calls to a Windows mouse and keyboard API in a Microsoft Windows operating environment. This allows development of the Unity interface to use only mouse and keyboard inputs, and then control it with the glove by having the 2D touchpad control the mouse when in Manual Drive modes. In one variation, the mouse is overridden in differential mode due to compatibility issues with Unity, but also may be utilized to control it using absolute mode if it would improve the interaction for a given application. [0141] In one variation, upon settling on the concept of a glove and HMO interface, the design concept may be evaluated using a paper modeling session and a physical prototype. Simply sketching out the views the user would see (the first step in the paper prototyping method) may be highly informative, as it may be utilized to turn abstract notions of finger tactile motions into concrete realities, and assist with assessing which finger motions are best mapped to interface actions. Once in a paper prototyping session however, thoughts about the best finger gestures may turn out to be difficult for users to perform. As a direct result of our paper prototyping session, a vector interface may be developed to select various objects in the interface, rather than using a tap-based method to traverse the screen. [0142] In addition to the paper prototype, a physical prototype (a piece of cloth with a conductive thread sewn in a grid) may be created to test the concept of using conductive thread as a touch imager. This may be utilized as a foundation for developing code, and may be fundamental for developing the image-based finger position extraction. It additionally may serve as a prototype for stitching methods. [0143] In practice, usability tests have been conducted with a group of 6 users. Each session started with demonstrating the system, to show the users the different interaction options the glove supports, such as the touchpad on index and middle fingers to control the 2D-motion, the 1D slider to pick items from a list, and the vector input mode for choosing items in the interface, and the various touch-types. Within five minutes all users were reasonably competent in the interface, the only consistent challenge being that they struggled to remember the different fingers combinations for different robot commands. As this is a novel application and users had no familiarity with the command set (and we targeted the application for expert risers}, the level of performance we observed with five minutes of training is exceptional. Adding a one-touch option to display possible finger commands in the current context is a method that may be utilized to increase system learning efficiency. Users have been enamored with the glove's capabilities control robots in three dimensions. [0144] In another variation, wired leads may be converted to wireless communication bridges, as the wires inhibit user motion and therefore glove practicality. Second, the conductive threads (and the wires that attach to them) may be more fragile than is desired, and may be replaced in one variation with conductive ink, or a highly-robust conductive thread, to improve real-world robustness. Finally, for free-motion capture, or joystick-like interactions, gyros and/or accelerometers may be incorporated in the form of one or more inertial measurement units (“IMU” devices) coupled to a portion of the glove, such as the back of the glove. [0145] Various exemplary embodiments of the invention are described herein. Reference is made to these examples in a non-limiting sense. They are provided to illustrate more broadly applicable aspects of the invention. Various changes may be made to the invention described and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act(s) or step(s) to the objective(s), spirit or scope of the present invention. Further, as will be appreciated by those with skill in the art that each of the individual variations described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present inventions. All such modifications are intended to be within the scope of claims associated with this disclosure. [0146] The invention includes methods that may be performed using the subject devices. The methods may comprise the act of providing such a suitable device. Such provision may be performed by the end user. In other words, the “providing” act merely requires the end user obtain, access, approach, position, set-up, activate, power-up or otherwise act to provide the requisite device in the subject method. Methods recited herein may be carried out in any order of the recited events which is logically possible, as well as in the recited order of events. [0147] Exemplary aspects of the invention, together with details regarding material selection and manufacture have been set forth above. As for other details of the present invention, these may be appreciated in connection with the above-referenced patents and publications as well as generally known or appreciated by those with skill in the art. The same may hold true with respect to method-based aspects of the invention in terms of additional acts as commonly or logically employed. [0148] In addition, though the invention has been described in reference to several examples optionally incorporating various features, the invention is not to be limited to that which is described or indicated as contemplated with respect to each variation of the invention. Various changes may be made to the invention described and equivalents (whether recited herein or not included for the sake of some brevity) may be substituted without departing from the true spirit and scope of the invention. In addition, where a range of values is provided, it is understood that every intervening value, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. [0149] Also, it is contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with any one or more of the features described herein. Reference to a singular item, includes the possibility that there are plural of the same items present. More specifically, as used herein and in claims associated hereto, the singular forms “a,” “an,” “said,” and “the” include plural referents unless the specifically stated otherwise. In other words, use of the articles allow for “at least one” of the subject item in the description above as well as claims associated with this disclosure. It is further noted that such claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. [0150] Without the use of such exclusive terminology, the term “comprising” in claims associated with this disclosure shall allow for the inclusion of any additional element--irrespective of whether a given number of elements are enumerated in such claims, or the addition of a feature could be regarded as transforming the nature of an element set forth in such claims. Except as specifically defined herein, all technical and scientific terms used herein are to be given as broad a commonly understood meaning as possible while maintaining claim validity. [0151] The breadth of the present invention is not to be limited to the examples provided and/or the subject specification, but rather only by the scope of claim language associated with this disclosure. [0152] The invention described herein may be manufactured and used by or for the United States Government for United States Government purposes without payment of royalties thereon or therefore.

One embodiment is directed to a system for human-computer interface, comprising an input device configured to provide two or more dimensions of operational input to a processor based at least in part upon a rubbing contact pattern between two or more digits of the same human hand that is interpreted by the input device. The input device may be configured to provide two orthogonal dimensions of operational input pertinent to a three-dimensional virtual environment presented, at least in part, by the processor. The input device may be configured to detect the rubbing between a specific digit in a pen-like function against one or more other digits. The input device further may be configured to detect the rubbing between the specific digit in a pen-like function and one or more other digits in a receiving panel function.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority from Korean Patent Application No. 10-2015-0148989, filed on Oct. 26, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. FIELD [0002] The present disclosure relates to monomeric avidin-like proteins with a strong and stable biotin-binding ability, protein conjugates containing two or more of the monomeric avidin-like proteins and having a multivalent binding ability to biotin, nucleic acid molecules for encoding the monomeric avidin-like proteins, and methods for producing the monomeric avidin-like proteins. BACKGROUND [0003] Streptavidin (STA) and avidin proteins are homotetramers that have extraordinarily high binding affinities for the small molecule biotin (K d −10 −14 M)[1]. This remarkably strong and specific interaction between streptavidin or avidin and biotin has been exploited in a wide range of applications, such as bio-interfaces to nanostructure assembly and molecular labeling [2]. The tetrameric form of avidin proteins, however, may cause unwanted cross-linking of the biotin conjugates. For example, streptavidin-based labeling of biotinylated cell-surface receptors disrupted the normal function of the receptors through oligomerization [3]. However, the development of monomeric streptavidin or avidin without a dramatic decrease (K d ˜10 −7 -10 −9 M) in biotin affinity has not been successful because a tryptophan residue from an adjacent subunit is critical for strong biotin binding [4-7]. Instead, a tetrameric but monovalent streptavidin with a single biotin binding site was developed [3]. Although this monovalent streptavidin is very effective for biotin labeling without cross-linking [8], a truly monomeric streptavidin or avidin protein is still highly desired for minimal perturbation of biotin-labeled targets and even more diverse applications of avidin proteins. For example, monomeric avidin can be genetically fused with other target proteins without oligomerization, and this fusion will also allow a new form of creation having different spatial organization and valency of the biotin binding sites. [0004] Throughout the entire specification, many papers and patent documents are referenced and their citations are represented. The disclosure of the cited papers and patent documents are entirely incorporated by reference into the present specification and the level of the technical field within which the present invention falls, and the details of the present invention are explained more clearly. SUMMARY [0005] The present inventors researched and endeavored to develop monomeric avidin. As a result, the present inventors monomerized rhizavidin by introducing a mutation at the interface of monomers of dimeric rhizavidin, which is one of the avidin proteins, and further improved the binding stability with biotin by further introducing additional amino acid alterations to the obtained monomeric avidin, and thus have completed the present invention. [0006] An aspect of the present invention is to provide monomeric avidin-like proteins having a strong and stable biotin-binding ability. [0007] Another aspect of the present invention is to provide protein conjugates containing two or more of the monomeric avidin-like proteins and having a multivalent binding ability to biotin. [0008] Still another aspect of the present invention is to provide nucleic acid molecules for encoding the monomeric avidin-like proteins. [0009] Still another aspect of the present invention is to provide methods for producing the monomeric avidin-like proteins and the protein conjugates having a multivalent binding ability to biotin. [0010] Other purposes and advantages of the present disclosure will become more obvious with the following detailed description of the invention, claims, and drawings. [0011] In order to accomplish these objects, there is provided a monomeric avidin-like protein with a strong and stable biotin-binding ability, including an amino acid sequence in which the 67 th , 71 st , 82 nd , 84 th , 101 st , and 105 th amino acid residues of SEQ ID NO: 1 are substituted with charged and hydrophilic amino acids, wherein the charged and hydrophilic amino acids are selected from the group consisting of aspartic acid, lysine, asparagine, glutamine, and arginine. [0012] The present inventors researched and endeavored to develop monomeric avidin. As a result, the present inventors monomerized rhizavidin by introducing a mutation at the interface of monomers of dimeric rhizavidin, which is one of the avidin proteins, and further improved the binding stability with biotin by further introducing additional amino acid alterations to the obtained monomeric avidin. [0013] As used herein, the term “monomeric avidin-like protein” is used to underline having a monomeric form thereof that is differentiated from existing avidin proteins in view of the form, while it has a biotin-binding ability, like avidin proteins. In addition, herein, the term “monomeric avidin-like protein” is used together with the term “monodin” or “monomeric avidin”. [0014] The monomeric avidin-like protein of the present invention basically includes the amino acid sequence of SEQ ID NO: 1, wherein 67 th (alanine), 71 st (glycine), 82 nd (alanine), 84 th (glycine), 101 st (serine), and 105 th (alanine) amino acid residues are substituted with charged and hydrophilic amino acids. The substitution of amino acid residues at these sites is an important factor in producing monomeric avidin proteins having a biotin-binding ability. [0015] According to an embodiment of the present invention, SEQ ID NO: 1 is an amino acid sequence derived from a monomer constituting rhizavidin, which is a dimeric avidin protein. Rhizavidin is the first naturally occurring dimer in the avidin protein family with a high binding affinity for biotin. SEQ ID NO: 1 is a sequence in a truncated form in which some sequences at the N-termini and C-termini are removed from the full-length of a monomer constituting rhizavidin. [0016] According to an embodiment of the present invention, the monomeric avidin-like protein of the present invention includes the amino acid sequence of SEQ ID NO: 2. SEQ ID NO: 2 is a sequence in which the 67 th (alanine), 71 st (glycine), 82 nd (alanine), 84 th (glycine), 101 st (serine), and 105 th (alanine) amino acid residues of SEQ ID NO: 1 are substituted with aspartic acid, lysine, asparagine, glutamine, arginine, and lysine, respectively. [0017] The monomeric avidin-like protein of the protein may have an additional amino acid substitution in order to further improve the binding stability with biotin. [0018] According to an embodiment, the monomeric avidin-like protein of the present invention includes an amino acid sequence in which the 23 rd (serine), 46 th (glutamine), and 115 th (glutamic acid) amino acid residues of SEQ ID NO: 1 are further substituted with amino acids selected from the group consisting of histidine, glutamic acid, and tryptophan. [0019] According to a more specific embodiment of the present invention, the monomeric avidin-like protein of the present invention includes the amino acid sequence of SEQ ID NO: 3. SEQ ID NO: 3 is a sequence in which 23 rd (serine), 46 th (glutamine), and 115 th (glutamic acid) amino acid residues of SEQ ID NO: 2 are substituted with histidine, glutamic acid, and tryptophan, respectively. The monomeric avidin-like protein of SEQ ID NO: 3 is described under the name of monodin in examples below, and as confirmed in the examples, although it has a monomeric form, the biotin-binding stability thereof was almost as stable as tetrameric streptavidin. [0020] According to an embodiment, with respect to the binding affinity to a biotin conjugate, the monomeric avidin-like protein has an off-rate of 0.5×10 −5 s −1 to 7.0×10 −5 s −1 . In a specific embodiment, the off-rate is 0.6×10 −5 s −1 to 7.0×10 −5 s −1 , 0.7×10 −5 s −1 to 7.0×10 −5 s −1 , 0.8×10 −5 s 1 to 7.0×10 −5 s 1 , 0.9×10 −5 s −1 to 7.0×10 −5 s −1 , or 1.0×10 −5 s −1 to 7.0×10 −5 s −1 . [0021] The off-rate may be measured at a temperature of 23-45° C. [0022] According to a more specific embodiment, the off-rate 23° C. is 1.0×10 −5 s −1 or smaller (e.g., 0.5×10 −5 s −1 to 1.0×10 −5 s −1 , 0.6×10 −5 s −1 to 1.0×10 −5 s −1 , 0.7×10 −5 s −1 to 1.0×10 −5 s −1 , 0.8×10 −5 s −1 to 1.0×10 −5 s −1 , or 0.9×10 −5 s −1 to 1.0×10 −5 s −1 ) when measured at 23° C.; 6.0×10 −5 s −1 to 6.7×10 −5 s −1 at 45° C., and 2.0×10 −5 s −1 to 6.2×10 −5 s −1 at 37° C. [0023] According to an embodiment of the present invention, the biotin conjugate is a conjugate of biotin and a protein, a conjugate of biotin and a peptide, or a conjugate of biotin and a nucleic acid. [0024] The sequences of the monomeric avidin-like protein described herein and biological equivalents thereof, so long as they can bind to biotin, may be included in the scope of the present invention. For example, in order to further improve binding affinity and/or other biological characteristics of the avidin-like protein, the amino acid sequence thereof may be additionally altered. Such alterations include, for example, deletion, insertion, and/or substitution of amino acid residues in the amino acid sequence of the avidin-like protein. Such amino acid mutations are based on the relative similarity of the amino acid side-chain substituents, for example, their hydrophobicity, hydrophilicity, charge, size, or the like. An analysis of the size, shape, and type of the amino acid side-chain substituents may reveal that: arginine, lysine, and histidine are all positively charged residues; alanine, glycine, and serine are similar in size; and phenylalanine, tryptophan, and tyrosine are similar in shape. Therefore, on the basis of these considerations, arginine, lysine, and histidine; alanine, glycine, and serine; and phenylalanine, tryptophan, and tyrosine may be considered to be biologically functional equivalents. [0025] For introducing mutations, hydropathy indexes of amino acids may be considered. Each amino acid residue has been assigned a hydropathic index on the basis of its hydrophobicity and charge characteristics: isoleucine (+4.5); valine (+4.2); leucine (+3.8); phenylalanine (+2.8); cysteine/cystine (+2.5); methionine (+1.9); alanine (+1.8); glycine (−0.4); threonine (−0.7); serine (−0.8); tryptophan (−0.9); tyrosine (−1.3); proline (−1.6); histidine (−3.2); glutamic acid (−3.5); glutamine (−3.5); aspartic acid (−3.5); asparagine (−3.5); lysine (−3.9); and arginine (−4.5). [0026] Meanwhile, it is also well known that the substitution between amino acids with similar hydrophilicity values results in proteins having equivalent biological activity. As disclosed in U.S. Pat. No. 4,554,101, each amino acid residue has been assigned the following hydrophilicity values: arginine (+3.0); lysine (+3.0); aspartic acid (+3.0±1); glutamic acid (+3.0±1); serine (+0.3); asparagine (+0.2); glutamine (+0.2); glycine (0); threonine (−0.4); proline (−0.5±1); alanine (−0.5); histidine (−0.5); cysteine (−1.0); methionine (−1.3); valine (−1.5); leucine (−1.8); isoleucine (−1.8); tyrosine (−2.3); phenylalanine (−2.5); tryptophan (−3.4). [0027] Amino acid exchanges in the protein, which do not generally alter the molecular activity, are known in the art (H. Neurath, R. L. Hill, The Proteins, Academic Press, New York, 1979). The most commonly occurring exchanges are changes between amino acid residues Ala/Ser, Val/Ile, Asp/Glu, Thr/Ser, Ala/Gly, Ala/Thr, Ser/Asn, Ala/Val, Ser/Gly, Thy/Phe, Ala/Pro, Lys/Arg, Asp/Asn, Leu/Ile, Leu/Val, Ala/Glu, and Asp/Gly. [0028] Considering the foregoing mutations with the biological equivalent activity, the avidin-like protein of the present invention is construed to also include sequences having substantial identity to the sequences set forth in the sequence listings. The substantial identity means that, when the sequence of the present invention and another optional sequence are aligned to correspond to each other as much as possible and the aligned sequences are analyzed using an algorithm normally used in the art, the corresponding sequences have at least 61%, more preferably at least 70%, still more preferably at least 80%, and most preferably at least 90% sequence identity. Methods of alignment for sequence comparison are known in the art. Various methods and algorithms for alignment are disclosed in Smith and Waterman, Adv. Appl. Math . (1981) 2:482; Needleman and Wunsch, J. Mol. Bio . (1970) 48:443; Pearson and Lipman, Methods in Mol. Biol . (1988) 24: 307-31; Higgins and Sharp, Gene (1988) 73:237-44; Higgins and Sharp, CABIOS (1989) 5:151-3; Corpet et al., Nuc. Acids Res . (1988) 16:10881-90; Huang et al., Comp. Appl. BioSci . (1992) 8:155-65 and Pearson et al., Meth. Mol. Biol . (1994) 24:307-31. The NCBI Basic Local Alignment Search Tool (BLAST, Altschul et al., J. Mol. Biol . (1990) 215:403-10) is available from the NCBI, and on the Internet, for use in connection with the sequence analysis programs blastp, blasm, blastx, tblastn, and tblastx. BLAST can be accessed at http://www.ncbi.nlm.nih.gov/BLAST/. A description of how to determine sequence identity using this program is available at http://www.ncbi.nlm.nih.gov/BI-AST/blast help.html. [0029] In accordance with another aspect of the present invention, there is provided a protein conjugate including: a multimeric protein; and two or more of the monomeric avidin-like proteins, the protein conjugate having a multivalent binding ability to biotin. [0030] As used herein, the “multimeric protein” refers to a molecule protein of some monomers bound together or a molecule protein composed of two or more polypeptide chains. The monovalent monomeric avidin-like protein of the present invention is bound to each monomer or polypeptide sequence constituting the multimeric protein to obtain a protein conjugate having a multivalent binding ability to biotin. [0031] According to an embodiment, the multimeric protein is 24-meric ferritin. [0032] In accordance with still another aspect of the present invention, there is provided a nucleic acid molecule for encoding the monomeric avidin-like protein. [0033] As used herein, the term “nucleic acid molecule” refers to comprehensively including DNA (gDNA and cDNA) and RNA molecules, and the nucleotide as a basic component unit in the nucleic acid molecule includes naturally occurring nucleotides and analogues with modified sugars or bases (Scheit, Nucleotide Analogs, John Wiley, New York (1980); Uhlman, and Peyman, Chemical Reviews, 90:543-584(1990)). [0034] The sequence of the nucleic acid molecule for encoding the monomeric avidin-like protein of the present invention may be altered. The alteration includes addition, deletion, or non-conservative substitution or conservative substitution of nucleotides. [0035] In accordance with still another aspect of the present invention, there is provided a method for producing a monomeric avidin-like protein with a biotin binding ability, the method including: [0036] (a) transforming a host cell with a recombinant vector comprising the nucleic acid of claim 11 ; and [0037] (b) culturing the transformant to express a monomeric avidin-like protein having a biotin binding ability. [0038] As used herein, the term “vector” refers to any vehicle that is used to express a target gene in a host cell, and encompasses: plasmid vectors; cosmid vectors; and viral vectors, such as bacteriophage vectors, adenoviral vectors, retroviral vectors, and adeno-associated viral vectors. [0039] In the recombinant vector, the nucleic acid molecule for encoding the monomeric avidin-like protein is operatively linked to a promoter. The term “operatively linked” refers to a functional linkage between a nucleic acid expression regulatory sequence (e.g., a promoter, a signal sequence, or an array of transcriptional regulatory factor binding sites) and another nucleic acid sequence, and the regulatory sequence thus regulates the transcription and/or translation of the other nucleic acid sequence. [0040] The recombinant vector system may be constructed by various methods that are known in the art, and a specific method therefor is disclosed in Sambrook et al., Molecular Cloning, A Laboratory Manual , Cold Spring Harbor Laboratory Press (2001), which is incorporated herein by reference. [0041] The recombinant vector may be constructed by employing eukaryotic cells or prokaryotic cells as host cells. In cases where the recombinant vector is an expression vector and employs a prokaryotic cell as a host cell, it generally includes strong promoters to initiate transcription (e.g., tac promoter, lac promoter, lacUV5 promoter, lpp promoter, p L λ promoter, p R λ promoter, racy promoter, amp promoter, recA promoter, SP6 promoter, trp promoter, and T7 promoter), a ribosome binding site for translation initiation, and transcription/translation termination sequences. In cases where E. coli (e.g., HB101, BL21, DH5α etc.) is used as a host cell, the promoter and operator regions for the E. coli tryptophan biosynthesis pathway (Yanofsky, C., J. Bacteriol ., (1984) 158:1018-1024) and the leftward promoter from phage A (p L λ promoter, Herskowitz, I. and Hagen, D., Ann. Rev. Genet ., (1980) 14:399-445) may be used as a regulatory region. Bacillus as the host cell may use the promoter of a toxic protein gene of Bacillus thuringiensis ( Appl. Environ. Microbiol . (1998) 64:3932-3938 ; Mol. Gen. Genet . (1996) 250:734-741) or any promoter that can be expressed in Bacillus , as the regulatory region. [0042] The recombinant vector may be constructed by manipulating a plasmid (e.g.: pCL, pSC101, pGV1106, pACYC177, ColE1, pKT230, pME290, pBR322, pUC8/9, pUC6, pBD9, pHC79, pIJ61, pLAFR1, pHV14, pGEX series, pET series, pUC19, etc.), phages (e.g.: Agt4.λB, λ-Charon, λΔz1, M13, etc.) or a virus (e.g.: SV40, etc.) that is commonly used in the art. [0043] On the other hand, in cases where the recombinant vector is an expression vector, and employs an eukaryotic cell as a host cell, the recombinant may employ a promoter derived from the genome of mammalian cells (e.g., metallothionein promoter, β-actin promoter, human hemoglobin promoter, and human muscle creatine promoter) or a promoter derived from mammalian viruses (e.g., adenovirus late promoter, vaccinia virus 7.5K promoter, SV40 promoter, cytomegalovirus promoter, tk promoter of HSV, mouse mammary tumor virus (MMTV) promoter, LTR promoter of HIV, promoter of moloney virus, Epstein barr virus (EBV) promoter and Rous sarcoma virus (RSV) promoter), and may typically have a polyadenylated sequence as the transcription termination sequence. [0044] The recombinant vector may be fused with the other sequences to facilitate the purification of the proteins expressed therefrom. Examples of the fusion sequence include, for example, glutathione S-transferase (Pharmacia, USA), maltose binding protein (NEB, USA), FLAG (IBI, USA), and 6× His (hexahistidine; Quiagen, USA). [0045] Any host cell that is known in the art may be used as a host cell capable of stably and continuously cloning and expressing the recombinant vector, and examples thereof may include prokaryotic host cells, for example, Escherichia coli, Bacillus sp. strains, such as Bacillus subtilis and Bacillus thuringiensis, Streptomyces, Pseudomonas (e.g., Pseudomonas putida ), Proteus mirabilis or Staphylococcus (e.g., Staphylocus carnosus ). [0046] Suitable eukaryotic cells for the recombinant vector may include fungus (such as Aspergillus species), yeasts (such as Pichia pastoris, Saccharomyces cerevisiae, Schizosaccharomyces , and Neurospora crassa ), the other lower eukaryotic cells, cells of higher eukaryotes, such as insect-derived cells, and cells derived from plants or mammals. [0047] As used herein, the “transformation” into host cells include any method by which nucleic acids are introduced into organism, cells, tissues, or organs, and as known in the art, suitable standard techniques according to host cells may be selected and performed. Examples of the techniques may include electroporation, protoplast fusion, calcium phosphate (CaPO4) precipitation, calcium chloride (CaCl 2 ) precipitation, agitation using silicon carbide fibers, agrobacteria-mediated transformation, PEG, dextran sulfate, lipofectamine, and drying/inhibition-mediated transformation, but are not limited thereto. [0048] In step (b), the transformed host cells may be cultured in a suitable media known in the art according to culturing conditions. The culture procedure can be easily manipulated according to the selected strain by a person skilled in the art. Various culture methods are disclosed in various literatures (e.g., James M. Lee, Biochemical Engineering , Prentice-Hall International Editions, 138-176). Cell culture methods are divided into suspension and adhesion culture according to the cell growth manner; and batch culture, fed-batch culture, and continuous culture according to the culturing method. The media used in the culture need to appropriately satisfy requirements for particular strains. [0049] The proteins obtained by culturing transformed host cells may be used in an unpurified condition, and may be purified at high purity, before use, by various normal methods, for example, dialysis, salt precipitation, and chromatography. Of these, the purification using chromatography is most frequently employed, and the kind and order of columns may be selected from ion-exchange chromatography, size-exclusion chromatography, affinity chromatography, and the like, according to the characteristics of protein, culturing method, and so on. [0050] Features and advantages of the present invention are summarized as follows: [0051] (i) The present invention provides monomeric avidin-like proteins with a strong and stable biotin-binding ability, protein conjugates containing two or more of the monomeric avidin-like proteins and having a multivalent binding ability to biotin, nucleic acid molecules for encoding the monomeric avidin-like proteins, and methods for producing the monomeric avidin-like proteins. [0052] (ii) The present invention, due to the monomeric structure, is free from a problem of the disruption of receptor functions, caused by oligomerization occurring in existing tetrameric streptavidin or tetrameric but monovalent streptavidin variants. [0053] (iii) The present invention can be used to prepare a high-valent avidin probe, and this avidin probe can be used to diversify the avidin/biotin binding strategy for constructing novel bio-structures and nano-structures. BRIEF DESCRIPTION OF THE DRAWINGS [0054] The above and other objects, features, and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings. [0055] FIG. 1 illustrates the production of a monomeric avidin-like protein. (a) Schematic diagram for engineering monomeric rhizavidin (mRA) and monodin (MA) from dimeric rhizavidin (RA). (b) Native-gel analysis of complex formation between biotin-GFP and dimeric RA or monomeric MA. (c) Size exclusion chromatography (left) and representative TEM images (right) of MBP and MBP-fused avidin proteins. Scale bars: 5 nm [0056] FIG. 2 illustrates dissociation rates of avidin proteins from biotin conjugates. (a) Off-rates from biotin-GFP at 45° C. Biotin-GFP was mixed with streptavidin (STA), rhizavidin (RA), or monodin (MA). After various incubation times with excess biotin at 45° C., the dissociated biotin-GFP was separated and measured on a 15% native-polyacrylamide gel (right). (b) Off-rates from biotin-DNA-fluorescein at 37° C. (c) Dissociation rates of avidin proteins from biotin-GFP (left) and biotin-DNA-fluorescein (right) at 23° C. Error bars: 1 s.d. (n=3). [0057] FIG. 3 illustrates Novel mono- and high-valent MA probes. (a) Histograms of diffusion constants of single-dye-labeled lipids and MA-labeled lipids in supported lipid bi-layers. (b) Representative TEM images of 24-meric human ferritin (Ft) and MA-fused ferritin (MA-Ft). Scale bars: 10 nm. (c) Artificial clustering of cell-surface proteins by mono- (MA), tetra- (STA), and 24-meric (MA-Ft) avidin proteins. Cell-surface proteins were randomly biotinylated and treated with Cy5-labeled avidin proteins at 4° C. Cell-surface labeling and subsequent internalization of avidin proteins were monitored at various time points during incubation for 30 min at 37° C. [0058] FIG. 4 illustrates the construction of monomeric avidin-like proteins. Schematic diagram for engineering monomeric rhizavidin with (a) one mutation (1M: S69R) or (b) ten mutations (10M: A67K, G71K, S101R, A105K, A82N, G84Q, F345, F65R, Y88H, I114D) from dimeric rhizavidin (RA). Biotin (black) and mutated residues (red and blue) are indicated. [0059] FIG. 5 illustrates biotin binding of monomeric avidin-like proteins. (a) Native-gel analysis of biotin binding characteristics of monomerized rhizavidin proteins (1M, mRA, 10M). The proteins were reacted with a biotinylated green fluorescent protein (biotin-GFP), and protein complexes were analyzed by 15% native-PAGE. (b) Binding stability of monomerized rhizavidin variants (mRA, 10M) for biotin-GFP in excessive biotin conditions. mRA and 10 M were reacted with biotin-GFP. After incubation with excess biotin at 37° C. for 30 min, the mixtures were analyzed using 15% native-PGA. While small amount of biotin-GFP was dissociated from mRA, most biotin-GFP was released from 10 M. [0060] The monomeric protein with a single mutation (1M: S69R) was very unstable and readily aggregated in buffered solutions because many hydrophobic residues at the dimeric interface are exposed to the solution. On the other hand, more heavily mutated monomers (mRA and 10 M) were stable without any aggregation (up to 1 mg/ml). As shown in (b) of FIG. 5 , upon incubation with excess free biotin, the dissociation from biotin-GFP, of the monomeric variant (10 M) with ten mutation residues, was faster than that of the monomer (mRA) with six mutations. [0061] FIG. 6 illustrates biotin binding stability of streptavidin (STA), rhizavidin (RA), and monomeric rhizavidin (mRA). Tetrameric STA, dimeric RA, and monomeric mRA were mixed with biotin-GFP, and the dissociation of biotin-GFP from avidin proteins under excess free biotin conditions were checked by native-PAGE analysis (at 37° C. for 30 min). The degrees of biotin-GFP dissociated from avidin proteins before (black) and after (red) the biotin addition were measured from background-calibrated intensities of free biotin-GFP bands on a fluorescence image. Over 40% of biotin-GFP was dissociated from mRA, while less than 20% of biotin-GFP was dissociated from multimeric STA or RA. [0062] FIG. 7 illustrates biotin binding stability of monomeric rhizavidin (mRA) variants. (a) The degrees of biotin-GFP dissociated from mRA mutants at E115 before (black) and after (red) the biotin addition (at 37° C. for 30 min). (a) The degrees of biotin-GFP dissociated from mRA mutants at E115, Q46, and S23 before (black) and after (red) the biotin addition (at 45° C. for 30 min). Selected mutations with optimally slowed off-rates from biotin-GFP were indicated with arrows. Although mRA with two tryptophan mutations (E115W and S23W) showed the least dissociation of biotin-GFP, mRAWW was highly prone to aggregation. [0063] FIG. 8 illustrates size exclusion chromatography of MBP and MBP-fused monomeric rhizavidin (mRA), and MBP-fused monodin (MA). Monodin slightly delayed an elution time due to the mutated surface residues (E115W, S23H, and Q46E). [0064] FIG. 9 illustrates TEM images of (a) MBP as well as MBP fused with (b) dimeric rhizavidin (RA), (c) monomeric rhizavidin (mRA), or (d) monodin (MA). Scale bars: 100 nm [0065] FIG. 10 illustrates dissociation rates of monodin (MA) and rhizavidin (RA) from protein-based biotin conjugates. In addition to biotin-GFP, the site-specific biotinylation peptide (AP) was also fused to relatively small (˜12 kDa) protein G (biotin-protein G). The AP-peptide with a fluorescent dye (biotin-AP) was also synthesized. These protein (or peptide)-based biotin conjugates showed similar binding stability to MA and RA (off-rates: 2-5×10 −5 s −1 ). [0066] FIG. 11 illustrates native gel analysis to determine dissociation rates of (a) monodin (MA) and (b) rhizavidin (RA) from biotin-DNA at 37° C. [0067] FIG. 12 illustrates native gel analysis to determine dissociation rates of streptavidin (STA), neutravidin (NA), monodin (MA), and rhizavidin (RA) from (a) biotin-DNA or (b) biotin-GFP at 23° C. Off-rates (summarized in Table S1) were examined by monitoring increased band intensities of dissociated free biotin conjugates. Complex formation with avidin proteins altered fluorescence signals of biotin conjugates in native gels. For example, fluorescence band intensities of biotin-DNA-fluorescein were significantly quenched by complex formation with RA, and a lesser degree with NA or MA. [0068] FIG. 13 illustrates surface plasmon resonance (SPR) results of binding stability of avidin proteins to surface-bound (a) biotin and (b) biotin-GFP. [0069] FIG. 14 illustrates dissociation rates of streptavidin (STA), monodin (MA), and rhizavidin (RA) from free [ 3 H]biotin. Avidin proteins were reacted with [ 3 H]biotin, and excess biotin was added to the mixtures. For free biotin, rhizavidin showed non-linear dissociation with t 1/2 300 s, and the off-rate of monodin (1.2±0.3×10 −5 s −1 ) was considerably faster than that of streptavidin (7.7±0.6×10 −5 s −1 ). [0070] FIG. 15 illustrates relative binding affinities (K d ) of a rhizavidin variant (RAWH) and monodin (MA) to free [ 3 H]biotin. (a) The relative binding affinity of RAWH-His was first estimated by analyzing competition binding for [ 3 H]biotin against streptavidin (STA). (b) shows measurement results of K d of MA-His by analyzing competitive binding with RAWH. Increasing concentrations of RAWH-His (or MA-His) was incubated with 20 nM [ 3 H]biotin and 50 nM streptavidin (or RAWH). After 20 h, RAWH-His (or MA-His) was removed using Ni-NTA agarose, and the amount of [ 3 H]biotin remaining bound to streptavidin (or RAWH) in the supernatant was measured. The relative binding affinity of RAWH-His (6.9 pM) for [ 3 H]biotin was 170-fold weaker than that of streptavidin (40 fM). In addition, the relative binding affinity of monodin (31 pM) for [ 3 H]biotin was 4.4-fold weaker than that of RAWH. [0071] FIG. 16 illustrates native gel analysis of MA-Ft. [0072] FIG. 17 illustrates TEM images of ferritin and monodin-fused ferritin (MA-Ft). Scale bars: 100 nm. [0073] FIG. 18 illustrates binding titration of MA-Ft with a biotinylated DNA probe. 0.1 μM of MA-Ft was titrated with varying concentrations of biotin-DNA (0-4 μM). The fluorescent intensity of the MA-Ft/biotin-DNA complex was saturated between 2.4 μM and 3.0 μM of biotin-DNA (MA-Ft/biotin-DNA molar ratios 1:24-1:30), supporting 24 biotin binding sites of MA-Ft. Free biotin-DNA migrated similar to the loading dye that also shows a weak fluorescence signal in a native gel. Clear levels of free biotin-DNA were observed only with over 2.4 μM of biotin-DNA. [0074] FIG. 19 illustrates non-specific interactions of dye-labeled MA-Ft on non-biotinylated (a) HeLa, (b) U2OS or (c) SOAS2 cells. [0075] FIG. 20 illustrates artificial clustering surface proteins on (a) U2OS, (b) SOAS2 by mono-(MA), tetra-(STA), and 24-meric (MA-Ft) avidin proteins. [0076] FIG. 21 illustrates localization of internalized proteins by artificial clustering with avidin proteins. Membrane proteins of HeLa cells were randomly biotinylated with Sulfo-NHS-LC-Biotin, and treated with Cy5-conjugated avidin proteins (red). After avidin binding at 4° C. for 20 min, HeLa cells were incubated at 37° C. for 30 min for protein internalization. Cells were then fixed, permeabilized, and then incubated with an anti-Rab11 or anti-LAMP1 antibody for endosomal or lysosomal labeling, respectively. Cells were incubated with a fluorescent secondary antibody (goat anti-rabbit 555, green), and images were acquired with a confocal microscopy. DETAILED DESCRIPTION [0077] Hereinafter, the present invention will be described in detail with reference to examples. These examples are only for illustrating the present invention more specifically, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. Examples [0078] 1. Materials and Methods Materials [0079] The genomic DNA of Rhizobium etli was purchased from ATCC (51251). All synthetic DNA oligonucleotides were purchased from Bioneer. pfu polymerase (Thermos Scientific) was used for standard polymerase chain reaction (PCT). PCR products and cleaved products by restriction enzymes were purified using DNA purification kit (Biorogen Co.). The restriction enzymes were purchased from Thermo Scientific. Site-directed mutagenesis was performed using QuikChange (Stratagene). Streptavidin was purchased from Abcam. Biotin (Pierce) was dissolved in 100 mM DMSO. Neutravidin (Pierce) was dissolved to 1 mg/ml in PBS. Biotin-AP (SEQ ID NO: 4) was synthesized by Peptron. [0080] Plasmid Construction [0081] The full-length gene of rhizavidin (Gene bank accession number U800928, 34860-35400) was amplified from the genomic DNA of Rhizobium etli . Rhizavidin (1 st to 178 th amino acid residues) was truncated to core rhizavidin (44 th to 171 st amino acid residues, SEQ ID NO: 1), which allowed higher-level protein expression in Escherichia coli ( E. coli ). Mutants were introduced into the coding sequence of the core rhizavidin using oligonucleotide-directed in vitro mutagenesis. All coding sequences were cloned into the pET21a expression vector (Novagen). To construct biotinylated proteins (biotin-GFP and biotin-protein G), the biotinylation peptide sequence (SEQ ID NO: 4) was added to the N-termini of protein G and negative charged GFP [1]. The genes for these proteins were cloned into the pProExHTa (Invitrogen) expression vector. To construct maltose-binding protein (MBP) fused monomeric and dimeric rhizavidin, the genes of MBP and avidin (RA, mRA, or MA) were amplified using PCR. The PCR products of the MBP were cleaved with restriction enzymes EcoRI/BamHI, and avidin PCR products (RA, mRNA, or MA) were cleaved with restriction enzymes BamHI/XhoI. The MBP and avidin (RA, mRNA, or MA) fragments were ligated to pET21a vector previously cleaved with restriction enzymes ExoRI/XhoI. The human FTH1 (heavy chain ferritin) gene was amplified by PCR from HeLa cDNA. The PCR products of FTH1 were cleaved with BamHI and XhoI, and cloned into pET21a vector. To bind monodin to the N-termini of the human FTH1 via the linker of protein G (MA-Ft), the genes of monodin and protein G were amplified using PCR, and cleaved with restriction enzymes NdeI/EcoRI and EcoRI/BamHI, respectively. DNA fragments were ligated to pET21a/FtH1 vector previously cleaved with NdeI and BamHI. [0082] Protein Preparation [0083] All avidin proteins were expressed in E. coli BL21 (DE3) cells. The transformed cells were grown at 37° C. until OD 600 =0.9, and proteins expressions were induced using IPTG, followed by additional incubation at 37° C. for 4 h. The expression-induced cells were suspended in Buffer A containing 1% Triton X-100 in 1×PBS. After sonication-based breakage, inclusion bodies were isolated from these cell lysates. The inclusion body pellets were washed three times with Buffer A and then dissolved in 6 M guanidinium hydrochloride (GuHCl) with pH 1.5. Proteins in GuHCl were refolded by rapid dilution into PBS at 4° C., and the obtained solutions were stirred overnight. Ni-NTA resin (Qiagen), equilibrated in 250 mM NaCl, 50 mM Tris pH 8.0, and 10 mM imidazole, was added to the refolding solutions, which were further incubated for 4 h at 4° C. The resin was added to a poly-prep column (Bio-Rad), washed with NiNTA washing buffer (300 mM NaCl, 50 mM Tris pH 8.0, 30 mM imidazole), and then eluted with Ni-NTA elution buffer (300 mM NaCl, 50 mM Tris pH 8.0, 200 mM imidazole). Purified proteins were dialyzed three times against PBS, and concentrations were determined after dialysis from OD 280 using &280 [2]. [0084] Biotin-GFP (SEQ ID NO: 5) and biotin-protein G (SEQ ID NO: 6) were expressed in AVB101 (Avidity), an E. coli B strain (hsdR, lon11, SulA1) containing pACYC184 plasmid, which produces biotin ligase BirA upon IPTG induction. Transformed AVB101 cells were grown in the presence of 50 μM biotin, and protein expression was induced by adding IPTG at the final concentration of 1 mM. After sonication-based breakage of expression-induced cells, clarified cell lysates were purified using a Ni-NTA column. Purified proteins were dialyzed against PBS, and stored at −20° C. before use. [0085] MBP fused avidin proteins (SEQ ID NOS: 7-9) were expressed in E. coli BL21 (DE3) cells. The transformed cells were grown at 37° C. until OD 600 =0.6, and then protein expressions were induced by 1 mM IPTG, followed by additional incubation at 25° C. for 16 h. The expression-induced cells were suspended in guanidinium lysis buffer (6 M GuHCl, 250 mM NaCl, 50 mM Tris pH 8.0, 10 mM imidazole). After sonication, clarified cell lysates were purified by Ni-NTA columns under denatured conditions. Purified proteins were refolded by rapid dilution into PBS at 4° C., and the obtained solutions were stirred overnight. Ni-NTA resin (Qiagen), equilibrated in 250 mM NaCl, 50 mM Tris pH 8.0, 10 mM imidazole, was added to the refolding solutions, which were further incubated at 4° C. for 4 h. The resin was added to a poly-prep column (Bio-Rad), washed with Ni-NTA washing buffer, and then eluted with Ni-NTA elution buffer. Purified proteins were dialyzed against PBS, and further purified by an amylose column. The final eluates were dialyzed against PBS. [0086] MA-Ft (SEQ ID NO: 10) was expressed in E. coli BL21 (DE3) cells. The transformed cells were grown at 37° C. until OD 600 =0.8, and protein expressions were induced by 1 mM IPTG, followed by additional incubation at 37° C. for 4 h. The expression-induced cells were resuspended in Buffer A. After sonication, inclusion bodies were recovered from these cell lysates by centrifugation at 12,000 rpm (4° C., 15 min), washed three times with Buffer A, and then solubilized by incubating in Buffer B containing 8 M urea, 250 mM NaCl, 50 mM Tris pH 8.0 at 4° C. for overnight. Denatured proteins were purified by the Ni-NTA column under denatured conditions. The purified proteins were mixed with an equal volume of Buffer B additionally containing 20 mM DTT to disrupt disulfide bonds, followed by further incubation at room temperature for 4 h. The purified and denatured proteins were refolded by sequentially dialyzing at 4° C. against 4, 3, 2, and 0 M urea in Buffer C (50 mM Tris pH 8.0, 50 mM NaCl, 10% glycerol, 0.1% polyethylene glycol (PEG), 0.2 mM glutathione (reduced), 0.1 mM glutathione (oxidized)) and Buffer D (50 mM Tris pH 8.0, 50 mM NaCl, 10% glycerol). [0087] Avidin proteins were labeled with a 10-fold molar excess of NHS-Cy5 (Invitrogen, stock dissolved to 5 mg/mL in dry dimethylformamide). Following 4 h reaction at 25° C., free dyes were removed by a desalting PD-10 column. Fractions containing labeled proteins were pooled, and free dyes were further removed by three rounds of dialysis in PBS. For gel filtration analysis, protein samples were loaded onto a 10×300 mm superdex 200-size exclusion column, which had been pre-equilibrated with 50 mM Tris pH 7.0, 150 mM NaCl, and eluted with the same buffer at a rate of 0.5 mL/min. [0088] Gel-Based Off-Rate Measurement Against Biotin Conjugates (Biotin-GFP, Biotin-DNA-Fluorescein, Biotin-Protein G-atto532 and Biotin-AP-Fluorescein). [0089] Avidin proteins (1 μM) in 10 μL PBS were mixed with biotin conjugates (0.7 μM biotin-GFP, 0.7 μM biotin-protein G-atto532, 0.7 μM biotin-AP-fluorescein (Peptron), and 0.1 μM biotin-DNA-fluorescein) in 10 μL PBS, and the mixtures were incubated for 30 min at room temperature. Excess biotin (2 mM in 10 μL PBS) was then added to initiate dissociation by blocking biotin non-binding) sites (free biotin binding sites) of avidin proteins. After incubation at the indicated temperature (23° C., 37° C., or 45° C.) for varying time points (between 0 to 10 h), protein-conjugate mixtures were loaded onto a 15% native polyacrylamide gel. Native-PAGE was performed at 300 V for 15-25 min using a standard 2-D Electrophoresis System (Hoefer) with cooling water flowing through the plates to prevent dissociation of avidin proteins from biotin conjugates during electrophoresis. Fluorescence images of native gels were obtained using a laser gel-scanner (Typhoon, GE Healthcare), and the degrees of biotin conjugates dissociated from avidin proteins were measured by platting image quant 5.2. Data as ln(fraction bound) versus time and fitting the data to a straight line by linear regression. Dissociation rates were deduced from the slope of the line and the following equation: [0000] ln(fraction bound)=− k off ( t ) where fraction bound=(total biotin-conjugate−free biotin-conjugate at time point)/(total biotin conjugate−free biotin-conjugate before excess biotin addition). [0091] [ 3 H]Biotin Off-Rate Assay [0092] To determine off-rates of free biotin from MA or wild type streptavidin, 50 nM [ 3 H]biotin (Amersham) was pre-incubated with 1 μM MA or wild type streptavidin at 25° C. for 30 min. Dissociation was then initiated by addition of cold biotin at a final concentration of 500 μM. At time-points taken over 5 h at 37° C., 150 μL of aliquots were removed, and added to 600 μL of 0.2 M ZnSO 4 (chilled with ice), followed by addition of 600 μL of 0.2 M NaOH. The protein precipitate was pelleted by centrifugation at 13,500 rpm for 5 min, and [ 3 H]biotin in the supernatant was measured by a liquid scintillation counter (Beckman Coulter). Dissociation rates were deduced as discussed above. [0093] K d Measurements [0094] The relative binding affinities of rhizavidin (RA) and monodin (MA) to free biotin were estimated by analyzing competition with streptavidin (K d -40 fM) for [ 3 H]biotin at 37° C. A rhizavidin variant (RAWH) with an enhanced biotin binding affinity by introducing E115W and S23H mutations was prepared. Wild type streptavidin (50 nM biotin binding subunit) was mixed with 20 nM [ 3 H]biotin and 0-40 μM competing RAWH-His6 in PBS. To determine relative K d of MA, RAWH (50 nM biotin binding subunit) without a His tag was mixed with 20 nM [ 3 H]biotin and 0-1 μM competing MA-His6 in PBS. Mixtures were incubated at 37° C. for 20 h to reach equilibration. To separate the His6-tagged RAWH (or MA-His6) from wild type streptavidin (or from RAWH), an equal volume of 50% slurry of Ni-NTA beads (Qiagen) in PBS with 15 mM imidazole was added. After 1 h incubation at room temperature, the beads were cleared by centrifugation at 13,000 rpm for 1 min. Aliquots were taken from the supernatant containing the biotin-bound wild type streptavidin (or RAWH), and combined with an equal volume of 10% SDS in water. Samples were heated to 95° C. for 30 min, and then counted in a liquid scintillation counter. The K d ratios between competing avidin proteins were calculated with Matlab (Mathworks) using the foregoing formula (Qureshi, M. H. & Wong, S. L. Protein Expr. Purif. 25, 409-415 (2002)). [0095] Surface Plasmon Resonance (SPR) Analysis [0096] SPR tests were performed in a Biacore 3000 instrument using dextran CM5 gold chips (GE Healthcare) and a PBS buffer as a running solution. To introduce biotin on the chip surface, diamine (sigma) was first immobilized, and subsequently reacted with NHS-biotin on flow cells. Alternatively, biotin-GFP was directly immobilized on CM5 chips via a standard EDC/NHS conjugation procedure as described in the manufacturer's protocol. Avidin proteins (5 μM) were flown over immobilized biotin or biotin-GFP at a rate of 30 μL/min. [0097] Transmission Electron Microscopy (TEM) [0098] Various avidin-fusion proteins were adsorbed to carbon grids, and negatively stained with 0.75% uranyl formate. Electron micrographs were acquired with a 4 K×4 K Eagle HS CCD camera (FEI) on a Tecnai T120 microscope (FEI) at 120 kV. Images were taken at a magnification of ×67,000 and defocus settings ranging from −1.4 to −1 μm. [0099] Measurement of Diffusion Constants Via Fluorescence Single-Molecule Tracking [0100] For the study of diffusion of a single lipid labeled by MA, supported bilayer membranes were prepared on cover glasses via vesicle fusion [5]. The present inventors prepared a lipid mixture of 1 mol % biotinylated 1,2-di(9Z-octadecenoyl)-sn-glycero-3-phosphocholine (DOPC, Avanti Polar Lipids) and 99 mol % 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC, Avanti Polar Lipids) for dye-conjugated MA labeling. In the control experiment, a trace amount (˜10 −6 mol %) of dye-labeled lipids, atto532-1,2-dioleoyl-sn-glycer-3-phosphoethanolamine (atto532-DOPE, ATTO-TEC-GmbH), was added into the DOPC lipids. The detailed procedures of preparing supported lipid bilayers can be well known (Laitinen, O. H. et al. J. Biol. Chem. 278, 4010-4014 (2003)). Briefly, the lipid mixture was dried in a glass vial with a stream of nitrogen, and put in a desiccator overnight to remove the organic solvent completely. The dried lipids were hydrated in HEPES buffer (150 mM NaCl and 10 mM HEPES) for 1 h. The hydrated lipid solution was treated with ultrasound (Q700, Qsonica) for 20 min, during which the lipid vesicles were formed. The lipid solution was centrifuged at 16,000 g for 20 min at 4° C. to remove large lipid clusters. The vesicles in the supernatant were collected for preparation of supported lipid bilayers. Cover glasses were cleaned thoroughly by 2% Hellmanex, followed by treatment with 1 M KOH for 15 min and extensive rinsing with deionized water. The cover glass was then treated with oxygen-plasma for 5 min right before adding the lipid vesicle solution. Lipid bilayer membranes were formed on the cover glass spontaneously within 10 min. Excess vesicles were removed by buffer exchange. [0101] Individual biotin-cap-DOPE (labeled with dye-conjugated MA) and atto532-DOPE were directly observed under a home-built inverted epi-fluorescence microscope. The wide-field excitation of ˜1 kW/cm 2 on the sample was created by focusing a 532 nm laser beam at the back focal point of a microscope objective (100×, NA 1.4). The epi-fluorescence image was monitored by an EMCCD camera. Diffusive motion of single molecules on the membrane was recorded in fluorescence at 100 frames per second. From the recorded video, positions of single molecules were determined in every frame with a localization precision of −35 nm. Diffusion trajectories were obtained by connecting the corresponding localizations in the consecutive frames. Only diffusion trajectories that are longer than 50 steps were considered for further analysis. Time-averaged mean squared displacement (MSD) was then calculated from each diffusion trajectory. The diffusion constant of each trajectory was found from the first two data points of the MSD. [0102] Cell Culture and Imaging [0103] Cells (HeLa, U2OS, and SOAS2) at 70-80% confluency were washed three times with cold PBS-CM (PBS with 1 mM CaCl2, 0.1 mM MgCl2) and were incubated with 0.25 mM Sulfo-NHS-LC Biotin in PBS-CM for 30 min on ice. Following biotinylation, the cells were washed twice with cold PBS-CM, treated with 100 mM glycine in PBS-CM for blocking, and washed again twice with cold PBS. The biotinylated cells were treated with 1.5 μM Cy5-labeled avidin proteins in DMEM, which was pre-treated to remove biotin, on ice for 20 min. Unbound avidin proteins were removed, and media was replaced with pre-warmed DMEM (37° C.). Cells were incubated for 5, 10, or 30 m at 37° C. Cells were washed, and fixed with 4% formaldehyde in PBS for confocal imaging (ZEISS, LSM510 META). To visualize endosome or lysozome-specific proteins, cells were fixed, permeabilized, and incubated with a primary antibody: anti-Rab11 (a GTPase of recycling endosome, Abcham) or anti-LAM P1 (Lysosomal-associated membrane protein 1, Abcham). Afterward, cells were incubated with a fluorescent secondary antibody (goat anti-rabbit 555, Abcham), and images were acquired with a confocal microscopy (ZEISS, LSM510 META). [0104] 2. Results [0105] Rhizavidin (RA) from Rhizobium etli is the first natural dimer in the avidin protein family with a high binding affinity for biotin (Helppolainen, S. H. et al. Biochem. J. 405, 397-405 (2007)). Interestingly, the biotin-binding pocket of rhizavidin consists of residues from a single monomer subunit, without tryptophan that is essential for tetrameric avidin homologs (Meir, A. et al. J. Mol. Biol. 386, 379-390 (2009)). Dimeric rhizavidin, however, contains a characteristic disulfide bond in the biotin binding site, which restrains the protein and leads to a rigid and preformed binding pocket for tight biotin binding. Therefore, the present inventors envisioned that a monomeric avidin protein with a high binding affinity for biotin could be derived from rhizavidin by monomerizing the dimer while minimally altering its natural structure, especially the rigid binding pocket. To monomerize rhizavidin, the present inventors introduced various numbers (one, six, and ten) of charged and hydrophilic amino acids, which have long side chains, at the dimeric interface ( FIG. 1( a ) and FIG. 4 ). The biotin binding properties of the rhizavidin variants were investigated by a gel mobility shift assay with a biotinylated green fluorescent protein ( FIG. 1( b ) and FIG. 5 ). Divalent wild type rhizavidin formed two separated complexes, whereas all the rhizavidin mutants formed a single complex with biotin-GFP, thus indicating successful monomerization of the protein. Of the monomerized proteins, the monomeric rhizavidin with six interfacial mutations, which are termed mRA, contains optimal modifications to stabilize the exposed dimeric interfaces as well as to maintain the rigid structure of rhizavidin for tight biotin binding ( FIG. 5 ). [0106] The relative dissociation of mRA from biotin-GFP by excess free biotin was still, however, much faster than that of dimeric rhizavidin ( FIG. 6 ), likely due to the inevitable loss of the overall protein rigidity by monomerization. Two amino acids (E115 and S23) near the entrance of the biotin binding site were mutated into various large (often hydrophobic) amino acid residues for biotin shielding ( FIG. 1( a ) , Hyre, D. E. et al. Nat. Struct. Biol. 9, 582-585 (2002)). In addition, a residue Q46 near E115 and S23 was mutated to a charged residue to maintain protein solubility by compensating for the enhanced hydrophobicity. Among many constructed mRA variants, the E115W/S23H/Q46E mutants showed a highly slowed off-rate from biotin-GFP, where dissociation was even similar to that of the original dimeric rhizavidin ( FIG. 7 ). The present inventors termed the optimized monomeric rhizavidin as monodin (MA). The monomeric structures of mRA and MA were further confirmed by size-exclusion chromatography (SEC) and transmission electron microscopy (TEM) ( FIG. 1( c ) ). The relatively large maltose binding protein (MBP, ˜44 kDa) was fused to both monomeric and dimeric rhizavidin proteins to improve the differences in the size as well as the shape of these proteins. Monodisperse and size-dependent elution profiles of free MBP and MBP-fused proteins support the highly homogeneous monomeric structure of monomerized rhizavidin proteins ( FIG. 1( c ) and FIG. 8 ). A single MBP is linked to monomeric mRA as well as MA, whereas MBP is dimerized by genetic fusion to dimeric rhizavidin ( FIG. 1( c ) , and FIG. 9 ). [0107] The stability of MA binding to various biotin conjugates was evaluated by measuring off-rates under excess biotin at diverse temperatures. At 45° C., the dissociation rate constant of MA from biotin-GFP was 6.4±0.2×10 −5 S −1 , which is nearly equal to that of rhizavidin, and only 3.4-fold faster than that of tetrameric streptavidin ( FIG. 2( a ) and table 1). At 37° C., the off-rate for MA (2.3±0.1×10 −5 S −1 ) indicated a dissociation half-life of 8.3 h, which is even slower than that of rhizavidin (3.8 h). [0108] The similar biotin binding stability of MA was also observed against another biotinylated protein as well as a peptide ( FIG. 10 ). The present inventors also conducted tests on the binding of biotinylated DNA to the avidin proteins. Interestingly, the dissociation of wild-type rhizavidin from biotin-DNA (23±0.1×10 −5 S −1 ) was considerably faster than that of MA (2.7±0.3×10 −5 S −1 ) at 37° C. ( FIG. 2( b ) and FIG. 11 ). In the cases of tetrameric streptavidin and neutravidin, only about 20% of the avidins were dissociated from biotin-DNA, even after incubation at 37° C. for 10 h (table 1). Impressively, at 23° C., monodin also showed only 22% dissociation from biotin-DNA after incubation for 10 h ( FIGS. 2( c ) and 12 ). Moreover, MA dissociation from biotin-GFP at 23° C. was similar to those of neutravidin and streptavidin (less than 7% dissociation after 10 h). The above results indicate that MA of the present invention has high stability to bind to various biotin conjugates, such as having the off-rate compared to (or even improved than) the dimeric rhizavidin. Dissociation of MA from surface-bound biotin conjugates was not observed by surface plasmon resonance (SPR) analysis ( FIG. 13 ). Against free biotin, MA showed a faster off-rate (1.2±0.3×10 −3 s −1 ) with a relative K d value of 31±10 pM at 37° C., which was estimated by analyzing the competition with streptavidin (K d -40 fM) for [ 3 H]biotin ( FIGS. 14 and 15 ). [0000] TABLE 1 Biotin- conjugate Temperature Protein Dissociation rate (s −1 ) Biotin-GFP 45° C. Monodin (MA) 6.4 ± 0.2 × 10 −5 Biotin-GFP 45° C. Rhizavidin (RA) 6.0 ± 0.6 × 10 −5 Biotin-GFP 45° C. Streptavidin (STA) 1.9 ± 0.2 × 10 −5 Biotin-GFP 45° C. Neutravidin (NA)  32 ± 5.0% for 10 h* Biotin-GFP 37° C. Monodin (MA) 2.3 ± 0.1 × 10 −5 Biotin-GFP 37° C. Rhizavidin (RA) 5.0 ± 0.1 × 10 −5 Biotin-GFP 37° C. Streptavidin (STA)  22 ± 4.4% for 10 h* Biotin-GFP 37° C. Neutravidin (NA)  16 ± 3.8% for 10 h* Biotin-GFP 23° C. Monodin (MA) 6.7 ± 1.1% for 10 h* Biotin-GFP 23° C. Rhizavidin (RA)  18 ± 3.0% for 10 h* Biotin-GFP 23° C. Streptavidin (STA) 4.7 ± 0.3% for 10 h* Biotin-GFP 23° C. Neutravidin (NA) 6.8 ± 1.6% for 10 h* Biotin- 37° C. Monodin (MA) 4.6 ± 1.5 × 10 −5 protein G Biotin- 37° C. Rhizavidin (RA) 3.2 ± 0.8 × 10 −5 protein G Biotin-AP 37° C. Monodin (MA) 5.1 ± 0.7 × 10 −5 Biotin-AP 37° C. Rhizavidin (RA) 4.9 ± 0.7 × 10 −5 Biotin-DNA 37° C. Monodin (MA) 2.7 ± 0.3 × 10 −5 Biotin-DNA 37° C. Rhizavidin (RA)  23 ± 0.1 × 10 −5 Biotin-DNA 37° C. Streptavidin (STA)  17 ± 1% for 10 h* Biotin-DNA 37° C. Neutravidin (NA)  20 ± 0.2% for 10 h* Biotin-DNA 23° C. Monodin (MA)  22 ± 6.0% for 10 h* Biotin-DNA 23° C. Rhizavidin (RA)  48 ± 6.1% for 10 h* Biotin-DNA 23° C. Streptavidin (STA) 6.8 ± 1.8% for 10 h* Biotin-DNA 23° C. Neutravidin (NA)  11 ± 4.4% for 10 h* *Off-rates that are slower than 1.0 × 10 −1 s −1 cannot be reliably measured by the present gelbased method. Therefore, percentages of dissociated biotin conjugates were measured after 10 h incubation with excess biotin. Data were obtained from at least three independent experiments. [0109] To investigate the monovalent (and thereby nonperturbing) biotin labeling by MA, the lateral diffusion dynamics of head-group-biotinylated lipids were measured on supported bilayer membranes labeled with dye-conjugated MA ( FIG. 3( a ) ). Diffusion trajectories of single-dye-conjugated MA labeled on the biotinylated lipids were directly observed under a fluorescence microscope (see Video S1). The lipids labeled with dye-conjugated MA showed similar diffusion constants as the lipids labeled with small atto-dye molecules ( FIG. 3( a ) ), which indicates that the labeling of MA is monovalent and does not modify the mobility of single lipids in the bilayer membranes. Biotin-lipid diffusion constants were previously found to be significantly reduced (more than twice) by multivalent labeling with streptavidin-conjugated quantum dots (Farlow, J. et al. Nat. Methods 10, 1203-1205 (2013)). [0110] In addition to monovalent biotin labeling, monomeric MA can be fused with diverse multimeric proteins to create new multivalent avidin probes. Here, the present inventors fused MA to 24-meric human ferritin, which is a cage-like protein with a diameter of −12 nm (Crichton, R. R. & Declercq, J. P. Biochim. Biophys. Acta 1800, 706-718 (2010)). Monodin-fused ferritin (MA-Ft) may have 24 biotin binding sites displayed symmetrically on the protein cage surface ( FIG. 3( b ) ). Native gel analyses confirmed that the fabricated MA-Ft has a monodisperse protein structure with a high molecular weight as well as MA having biotin binding ability ( FIG. 16 ). In addition, TEM images clearly revealed that MA-Ft was assembled into the cage-like structure and MA proteins were well displayed on the exterior surface of the ferritin cage ( FIG. 3( b ) and FIG. 17 ). A binding titration of MA-Ft with a biotinylated DNA probe strongly indicated that all 24 MA subunits of MA-Ft are able to bind the biotin-conjugated ligand ( FIG. 18 ). [0111] Next, the present inventors applied MA and MA-Ft to examine how enhanced cross-linking of cell-surface proteins affects the internalization rates of these proteins in live cells. Asymmetric protein crowding on a lipid bilayer and subsequent membrane bending is one of the proposed mechanisms for the generation of biomembrane curvatures, which is also likely to contribute to membrane internalization (Kirchhausen, T. Nat. Cell Biol. 14, 906-908 (2012); Stachowiak, J. C. et al. Nat. Cell Biol. 14, 944-949 (2012); Derganc, J., Antonny, B. & Copic, A. Trends Biochem. Sci. 38, 576-584 (2013)). However, little is known regarding how cell-surface membranes react to the artificial clustering of membrane-bound proteins. To generate various protein clusters on a live cell surface, membrane proteins were randomly biotinylated using a cell-impermeable agent, and subsequently treated with dye-conjugated avidin proteins from monomeric MA, tetrameric STA, to 24-meric MA-Ft ( FIG. 3( c ) ). Following avidin binding at 4° C., plasma membrane activities were initiated by a temperature change to 37° C. Monodin proteins (and biotin-labeled membrane proteins) on HeLa cells were slowly internalized after 30 min, whereas streptavidin proteins were visibly internalized after only 10 min ( FIG. 3( c ) ). Interestingly, 24-valent MA-Ft was nearly immediately internalized, with the protein signals being full inside the cytosols after incubation for 5 min at 37° C. The fluorescence signals of avidin proteins are biotin-specific, with no signals being detected without biotinylation ( FIG. 19 ). Rapid internalization by MA-Ft clustering was also observed in other cell lines, such as U2OS and SOAS2 cells ( FIG. 20 ). Internalized proteins appeared to remain clustered inside cells during incubation for 30 min without specific targeting to certain organelles ( FIG. 21 ). Although more studies are needed to elucidate the physical or cellular mechanism of clustered protein internalization, the above results show that the tight and high-valent cross-linking of membrane proteins leads to unusually fast internalization of protein. [0112] In conclusion, the present inventors prepared a monomeric avidin-like protein that showed almost multimeric avidin-like binding stability against various biotin conjugates. Off-rates of MA are often slower than those of dimeric rhizavidin, and even comparable to those of tetrameric avidin proteins at room temperature. The MA of the present invention offers the first practically applicable monomeric avidin linker, which allows truly monomeric biotin labeling with minimal perturbation. In addition, the possibility of fabricating new high-valent avidin probes with designed orientations and valencies (such as 24-meric MAFt) will greatly diversify avidin/biotin linking strategies to build new bio-structures and nanostructures. [0113] Although the present invention has been described in detail with reference to the specific features, it will be apparent to those skilled in the art that this description is only for a preferred embodiment and does not limit the scope of the present invention. Thus, the substantial scope of the present invention will be defined by the appended claims and equivalents thereof.

Disclosed are monomeric avidin-like proteins with a strong and stable biotin-binding ability, protein conjugates containing two or more of the monomeric avidin-like proteins and having a multivalent binding ability to biotin, nucleic acid molecules for encoding the monomeric avidin-like proteins, and methods for producing the monomeric avidin-like proteins, so the monomeric avidin-like proteins, due to the monomeric structure, are free from a problem of the disruption of receptor functions, caused by oligomerization occurring in existing tetrameric streptavidin or tetrameric but monovalent streptavidin variants.

FIELD OF THE INVENTION [0001] The present invention relates to the field of product authentication, especially with regard to the determination whether a product bought by a customer is an authentic product or a fake, and with regard to secure methods of communication for product authentication and tracking. BACKGROUND OF THE INVENTION [0002] Many companies suffer from counterfeit products produced by pirate manufacturers and their distributors. These fake products are manufactured to look like the authentic original products, but are in fact not so. Counterfeiting is a major problem in many market segments—pharmaceutical drugs, cosmetics, cigarettes, jewelry, clothing & shoes, auto parts. Tens of billions of dollars of counterfeited products are sold every year, resulting in huge losses to the manufacturers of the genuine products. [0003] Currently, although a number of means are used to validate the authenticity of products, such methods are not always reliable or user friendly for the purchaser of the product. The most common method used currently for the authentication function, is by adding to the package a special component such as a Hologram, which is meant to be unique to the manufacturer. [0004] The problems with this approach are: a) The holograms themselves can be faked by the product pirates, such that they look like the original hologram. b) Many consumers cannot tell the difference even if the fake hologram is somewhat different than the original one. c) The cost of a hologram makes it unpractical for low-cost items such as cigarettes. [0008] There is therefore a need for a simple and reliable method to allow the consumer to validate the authenticity of the product that he has purchased, whether in a shop, via mail delivery, over the internet, or otherwise. [0009] The use of Radio Frequency Identity Tags (RFID tags) to prevent fakes and counterfeit products is growing, despite the fact that RFID has a number of disadvantages, such as: p 0 (a) Cost is comparatively high, and RFID thus only makes sense for high value products. (b) Most users do not have RFID readers, so they have no means to check the authenticity of the RFID and the product, in their homes or even at the point of purchase. (c) Low-cost RFID chips can be produced, but such types are often insecure and can easily be cloned. [0012] It is to be noted that although the term RFID is formally used for identity tags which RF communicate with the outside world by means of the IEEE 802.13 protocol, the term RFID is used in this application in its generic sense, to mean an identity tag which communicates its information by radio frequency, whether or not it strictly conforms with the conventional communication protocol, and the invention is not meant to be limited thereto. [0013] There is therefore also a need for a simple and reliable method to allow the consumer to interrogate an electronic tag on a product, to validate the authenticity of the product that he has purchased, yet without the need for special RFID reading equipment. [0014] If such access to an electronic tag could be enabled, the means of communication could then be used to tackle not only verification, but also other problems related to tracing and tracking of products. There exist in the prior art a number of such systems for dynamic product information exchange, such as U.S. Pat. No. 7,126,481, for “Methods, Systems, Devices and Computer Program Products for Providing Dynamic Product Information in Short Range Communication”, assigned to the Nokia Corporation, and other art cited therein. However, this method and system bases itself on the information stored on the tag, and utilized by means of applications based on a cellular phone having access to an outside server carrying supporting applications. No access to a full database of products is described. There therefore exists a need for an authentication, verification and tracking communication system which has access to a full database of products. Additionally, where such a full database of products is regarded as commercially sensitive data, there is need for a method of authentication using the database, but avoiding such a sensitive concentration of data. [0015] The disclosures of each of the publications mentioned in this section and in other sections of the specification, are hereby incorporated by reference, each in its entirety. SUMMARY OF THE INVENTION [0016] The present invention seeks to provide a new authentication system that overcomes some of the disadvantages of prior art systems, from a number of aspects. According to the various embodiments of the present invention, the system enables a customer to verify the authenticity of the product he has or is going to purchase, in a foolproof, secure and simple manner. [0017] According to a first preferred embodiment, the system operates by associating with each product to be authenticated, a unique number set, comprising one or more character sequences. The number sets are generated by the product supplier and preferably stored at a remote central register of number sets, which can be tele-accessed by the customer. This number set can preferably be printed on the product or its packaging in a hidden manner, such as under a scratch-off layer. Alternatively and preferably, it can be included as a packing slip inside the product packaging, After purchase, the customer reveals the number set, and accesses the supplier's remote central register of number sets, where its presence can be used to authenticate the product as an original and not a fake. The remote checking system then returns the corresponding response to the customer. However, if the response is simply an affirmation or denial as to the authenticity of the product, in the form of a simple AUTHENTIC or FAKE response, depending on whether or not the character sequence sent by the customer exists in the central register as corresponding to a genuine number associated with an authentic product, it would be simple for the counterfeiters to include a bogus communication address with the product, contact with which always returns an AUTHENTIC verification answer. [0018] Therefore, according to this first preferred embodiment of the present invention, the number set preferably comprises at least a pair of character sequences, one of which is a challenge sequence, which the customer sends to the supplier's remote central register of numbers, preferably stored on a remote server, and another is a response sequence, predetermined to be associated with that specific challenge sequence, and stored on the remote central register of numbers. The Remote Checking System then sends back the response sequence matching the challenge sequence. If the returned Response sequence matches the second sequence of the number set associated with the product in his hand, the customer knows with high level of probability that his product is authentic. If the response disagrees, the product is likely to be a fake. The Remote Checking System can also optionally apply checks to the Challenge—the most important one being that the response is only generated once—the first time that that particular Challenge is received, thus thwarting attempts to circumvent the system by the wholesale use of a single authentic number set on numerous counterfeit products. [0019] According to this embodiment, the present invention thus generally comprises: 1. Secret sets of individual numbers, where each set may preferably be divided into a Challenge and one or more Responses. 2. Association of a single different one of these secret sets to each item which it is desired to protect. 3. A remote checking system where the number set associated with the product can be authenticated. [0023] In a typical case, one (or more) secret sets are associated with a product preferably either by covert printing on the packaging or by placing inside the packaging. The secret set should preferably be accessible for viewing by the end user only after the purchasing is done, and by affecting the packaging or some element of it. Once the consumer has purchased the product and wishes to authenticate it, he exposes the secret set (e.g. by scratching off the layer used to render the printing unobservable, or by opening the product package) and sends the Challenge part of the secret set to the Remote Checking System. The Remote Checking System then applies some checks on the Challenge—the most important one being to ascertain that this is the first time that this particular challenge has been presented. This check is essential to ensure that each number set is used only once, to ensure that persons using stolen or used secret numbers cannot achieve repeated access to the system with a single number set. If the checks are correctly passed, the Remote Checking System then sends back the correct response associated with that Challenge, and disenables or deletes the set from its storage, to ensure that the set is not used a second time by secret number thieves. The consumer then compares the response received with the Respond numbers on his packaging and if they match, he knows with high level of probability that he has purchased an original product. [0024] This preferred embodiment is generally useful for application to real, physical products such as medicines, food, cloths, toys, luxury items, etc., but cannot be used in a simple manner on ‘digital’ products such as files of content or software utilities, which could be doctored to generate their own, always-correct responses. [0025] According to a second preferred embodiment of the present invention, an electronic tag is used for identifying the product being checked. In order to provide the communication link between the tag and the manufacturer's central register of numbers without the need for a dedicated RFID reader, the product is verified using a regular cellular phone. Attached to the product is a secure electronic tag having a secure signature and encryption scheme. The system differs from those of the prior art, in which the tag is powered by means of charging generated from its own short-range communication channel, in that in this invention, the comparatively strong cellular phone transmission signal is used to charge the tag. The tag then broadcasts its information in one of the standard cellular phone short range communication methods, such as Bluetooth, NFC, IR, or similar. The cellular phone transmits the information to a server, which can either have full duplex communication with the tag or it can perform the authentication itself. This method thus enables the powering of a communication device by means of the transmission from a different communication channel. According to further preferred embodiments, the strong cellular transmission can be used to power more than one short range communication channel, each having its own antenna for picking up the cellular transmission, such as Bluetooth and a conventional RFID channel. [0026] Besides its use for the communication of authentication data, this embodiment of the present invention can also be used for general purpose communication of product data. It is a method for enabling a short range communication device, such as Bluetooth (BT), to communicate with a cellular handset by utilizing the cellular long range transmission signal to produce power for the device operation. [0027] According to a third preferred embodiment of the present invention, there is provided a novel vendor tag verification system, in which electronic tags attached to the end user product, are used for track and trace purposes and for authentication anti-counterfeiting purposes, using a cellular telephone having the ability to enable the validation act. The phone communicates the tag ID information to an external server containing a database with details of all of the tagged products, and handles the transfer and display of any information returned from the server to the user. According to this embodiment, for the verification aspects, the user's activation of the validation application causes the server to send a challenge through the user's phone to the tag, which responds through the phone to the server, which in turn decides whether the response is correct or not, and returns a response to the enquirer. For the tracking aspects, the server generally stores the response received from the tag as part of the database of the location and details of products, which can then be re-accessed for providing information about the location or details of any particular product. According to a further preferred embodiment, the cellular phone can provide to the server its physical location, which is generally close to the product being verified, such that the server can use this information to update a stock list of the actual location of products being tracked. [0028] Tracking/verification systems of this kind generally involve access to a complete manufacturer or prime-vendor database of all of the products sold for the whole of the lifetime of the product line. Such a database will generally contain commercially sensitive product volume and status data, such as the total number of products sold, the number of products rejected, the serial numbers of products whose expiry date has been reached, the number of products stolen, and the like. The manufacturer or vendors may not wish such data to be accessible in any manner from outside their own in-house data base, such that use of an externally accessible database with this information may not be advisable. [0029] According to a further preferred embodiment of the present invention, a tracking/verification system is provided in which the tracking/verification process involves initial access to a main server which, unlike the previous embodiment, does not have the entire product database, and therefore cannot give the verification response itself. Instead, the main server contains only information as to where the data relating to that particular product is kept on a satellite or secondary server. Thus for instance, on receipt of a product number query, the main server sends out a response, preferably encrypted, which contains a secondary server location ID associated with that product number, and access is provided just to the data on that secondary server. If each secondary server is associated, for instance, with a specific vendor of those products, then each enquiry for authentication or tracking of a particular product is directed to the server of the vendor who supplied the particular product queried. Each vendor database could only contain a fraction of the total product database, such that the commercial secrecy of the total product database is maintained. The main server accessed does not need to contain any relevant data about the product queried, other than a preferably encrypted database of vendors, which provides the identity of the secondary server associated with the vendor of that particular product. That secondary vendor database then decides what limited information will be presented back to the end user or to the store making the enquiry, and returns the information for display on the enquirer's cellular telephone. This embodiment has been described with the product information being situated on a series of vendor servers, since this is a logical location for that information. However, it is to be understood that the invention is not meant to be limited to information being maintained on vendor servers, but that any remote collection of servers can equally well be used in order to disperse and thus to protect the integrity of the complete product database. [0030] Alternatively and preferably, the server location information for each product could be contained in the ID carried by the electronic tag, which would then have two parts, an ID for the product itself, and an ID for the identity or location of the secondary server on which that product data is kept. According to this embodiment, the main server does not keep data relating to the secondary server associated with any product ID, since this is provided by the electronic tag itself. Instead, the main server operates as a routing server, directing the preferably encrypted product server information to the appropriate secondary server. In order to enable the secondary server information on the tag to be amended if necessary, such as when stock is moved, or is handled by a different vendor, according to this embodiment, the secondary server ID or location is preferably carried on the tag in a rewritable or flash memory. [0031] The system of this fourth preferred embodiment can be used for track and trace applications, such that the organization logistics team can determine the exact size, location and status of any item of the stock, spread over numerous locations, yet without compromising the sum total of the organization's stock situation on any one central server. [0032] The system according to this fourth preferred embodiment is described generally in this application as suitable for use with methods of interrogation of electronic tags using cellular telephones, whereby the phone sends the tag information to the main server, which simply passes it on to the secondary vendor server after determining which vendor server contains the particular information requested. However, it is to be understood that the method is equally applicable, at least for verification use, to systems where the product information is not contained on an electronic tag, but rather on a packet enclosure, or a covertly printed serial number, as described for the first embodiment of the present invention. [0033] In general, the activation of the authentication process can be executed by any suitable method, whether by key strokes on the cellular phone that activate a routine on the phone, or by the consumer calling a number that reaches a response center, or by sending an SMS to a response center, by sending an Instant Message to a response center, or by any similar method of communication available. Furthermore, the data flow itself can be initiated either by the tag, meaning that the handset asks the tag for a verification code and then sends it to the server; or by the cellular phone handset, meaning that the handset generates a “Challenge”; or by the server, meaning that the handset first asks the server for a “Challenge”, and then sends it to the tag. [0034] There is thus provided in accordance with a preferred embodiment of the present invention, a system for authenticating a product selected from a group of products, the system comprising: (i) a tag associated with the product, the tag containing information relating to the identity of the product, (ii) a plurality of secondary servers, each containing a database of information relating to a different part of the total group of products, and (iii) a database carried on a central server, the database comprising data regarding the identity of the secondary server which contains information relating to at least some of the products of the group, wherein the information on the tag is transferred to the central server, which, on the basis of its database, transfers the information to the appropriate secondary server for activating authentication of the product. [0039] In the above described system, the database on the central server preferably associates the secondary server identity of the product with the information relating to the identity of the product. Additionally, the database on each of the secondary servers may contain information relating to a common commercial aspect of the part of the total group of products contained on that database, and the common commercial aspect may preferably be the vendor of all of the products in that part of the total group of products. [0040] The information relating to essentially all of the products of the group is preferably all contained on one of the secondary servers, but no single server should contain a database of information relating to the entire group of the products. [0041] There is further provided in accordance with yet another preferred embodiment of the present invention a system as described above, and wherein the information on the tag is transferred to and from the central server through a cellular phone. [0042] In accordance with still another preferred embodiment of the present invention, the secondary server preferably either activates authentication of the product by checking information regarding the product on its database, and confirming or denying authenticity based on the information, or it activates authentication of the product by checking information regarding the product on its database, and sending a challenge back to the tag on the product, such that the product tag can respond to the challenge. In the latter case, the secondary server preferably may determine the authenticity of the product according to the response received back from the product tag. In any of these cases, the tag may preferably either be an electronic tag, and the response is generated electronically by the tag, or it may be a physically visible tag, and the response is generated by a user reading the information on the tag. In the latter case, the information on the tag is preferably inaccessible to the user until the product is in the possession of the user, such as by virtue of covert printing. [0043] There is further provided in accordance with still another preferred embodiment of the present invention, a system for authenticating a product selected from a group of products, the system comprising: (i) a tag associated with the product, the tag containing information relating to the identity of the product and to the identity of a secondary server on which additional information regarding the product is contained, (ii) a plurality of secondary servers, each containing a database of information relating to a different part of the total group of products, and (iii) a central server, receiving the product identity information and the secondary server identity information, and routing at least the product identity information to the appropriate secondary server, wherein the appropriate secondary server utilizes the information on its database for activating authentication of the product. [0048] In such a system, the appropriate secondary server preferably either activates authentication of the product by checking information regarding the product on its database, and confirming or denying authenticity based on the information, or it activates authentication of the product by checking information regarding the product on its database, and sending a challenge back to the tag on the product, such that the product tag can respond to the challenge. In the latter case, the secondary server may determine the authenticity of the product according to the response received back from the product tag. In any of these cases, the information on the tag is preferably transferred to and from the central server through a cellular phone. Furthermore, the information transferred between the product tag and at least the central server may preferably be encrypted. [0049] In accordance with a further preferred embodiment of the present invention, there is also provided a method for determining the authenticity of an item comprising: (i) generating a plurality of secret sets of individual character sequences, each secret set comprising a challenge and a response, and associating a different one of these secret sets to each item, (ii) storage of the secret sets on a checking system, such that input of a challenge to the system generates the return of the response connected with the challenge, (iii) sending to the checking system, the challenge part of a secret set associated with the item whose authenticity it is desired to determine, and (iv) comparing the response returned from the checking system with the response associated with the item. [0054] According to this method, the response preferably comprises at least one sequence of characters, and may preferably comprise more than one sequence of characters, each sequence having its own label, and the challenge then preferably includes a request for the sequence of characters in the response associated with a selected label. [0055] In any of these methods, the checking system is preferably adapted to send back the response associated with a secret set only once. [0056] In accordance with yet a further preferred embodiment of the present invention, in any of the above-mentioned methods, the secret set is preferably associated with the item by any one of printing, embossing, engraving, imprinting and stamping on any one of the item itself, the packaging of the item, an insert within the packaging of the item, and a label attached to the item. The secret set should preferably not be visually accessible to a customer until the customer has physical access to the item. Preferably, the secret set may be covered by an opaque scratch-off layer. [0057] In accordance with still another preferred embodiment of the present invention, the secret set is associated with the item in such a manner that evidence is left after visual access to the secret set has been achieved. Finally, in any of the above-described methods, the challenge part may be sent to the checking system by any one of a phone, a computer connected to the Internet, a set-top box, and a bar-code reader connected to a network. [0058] There is further provided in accordance with yet another preferred embodiment of the present invention, a system for determining the authenticity of an item comprising: (i) a secret number set comprising a challenge and a response, the secret number set being attached to the item in a manner such that the secret number set can be viewed only after the item has been purchased, (ii) a first entity that possesses the secret number set and wishes to determine the authenticity of the item, and (iii) a second entity that has knowledge of the secret number set, wherein the first entity sends only the challenge to the second entity, the second entity, based on the challenge, uses the secret number set to send a response back to the first entity, and the first entity checks if the response sent is identical to the response known to the first entity. [0062] In the above-mentioned system, the response preferably comprises at least one sequence of characters, and may preferably comprise more than one sequence of characters, each sequence having its own label, and the challenge then preferably includes a request for the sequence of characters in the response associated with a selected label. [0063] In either of these systems, the checking system is preferably adapted to send back the response associated with a secret set only once. [0064] In accordance with yet a further preferred embodiment of the present invention, in any of the above-mentioned systems, the first entity is a purchaser of the item, and the secret set is preferably associated with the item by any one of printing, embossing, engraving, imprinting and stamping on any one of the item itself, the packaging of the item, an insert within the packaging of the item, and a label attached to the item. The secret set should preferably not be visually accessible to a purchaser of the item until the purchaser has physical access to the item. Preferably, the secret set may be covered by an opaque scratch-off layer. [0065] In accordance with still another preferred embodiment of the present invention, the secret set is associated with the item in such a manner that evidence is left after visual access to the secret set has been achieved. Finally, in any of the above-described systems, the first entity preferably sends the challenge to the second entity by any one of a phone, a computer connected to the Internet, a set-top box, and a bar-code reader connected to a network. Finally, in such a system, the second entity may preferably be a remote server which contains a plurality of secret number sets, each secret number set being associated with a different predetermined item. [0066] In accordance with still another preferred embodiment of the present invention, there is further provided a system for enabling short range communication between an electronic device and a cellular phone, comprising: (i) an antenna on the device adapted to receive cellular transmission from the phone, and (ii) a short range communication channel, other than the cellular transmission, between the electronic device and the phone, wherein the electronic device is powered by the cellular transmission received through the antenna. [0070] According to various preferred embodiments of the present invention, the short range communication channel may be any one of a Bluetooth link, Radio Frequency Identification (RFID) channel, Near Field Communication (NFC), an Infra-red optical link, and a WiFi, WiMax or WiBree network. The electronic device may preferably be a tag containing information relating to the authenticity of an item, and the information is transmitted to the phone over the short range communication channel. Alternatively and preferably, the electronic device may be any one of an earphone, a microphone, and a headset. [0071] In accordance with still more preferred embodiments of the present invention, in this system, the electronic device may comprise a processing circuit and a short range communication device, both of which are powered by the cellular transmission received through the antenna. The device may further comprise a separate Radio Frequency Identification RFID channel having its own RFID antenna, such that the device is also able to be powered and communicate by RFID transmission. In the latter case, the device may be a dual mode tag containing information relating to the authenticity of an item. In all of these last mentioned systems including a short range communication channel, the communication between the phone and the electronic device may preferably be executed using a communication application activated by the phone user. [0072] In accordance with a further preferred embodiment of the present invention, there is also provided a system for enabling short range communication between an electronic device and a cellular phone operating on a first communication channel, the system comprising: (i) an antenna on the device adapted to receive cellular transmission from the phone on the first communication channel, and (ii) a second, short range communication channel between the electronic device and the phone, wherein the electronic device is powered by reception of transmission through the antenna from a source other than its own communication channel. In this system, the communication between the phone and the electronic device is preferably executed using a communication application activated by the phone user. [0076] There is also provided, in accordance with yet a further preferred embodiment of the present invention, a system for determining the authenticity of an item, comprising: (i) an electronic tag containing information relating to the item, (ii) a cellular phone providing cellular transmission, the phone being adapted to communicate with the tag over a short range communication channel other than the cellular transmission, and (iii) an antenna tuned to receive the cellular transmission, wherein the electronic tag is powered by the cellular transmission received through the antenna. In this system, the communication between the phone and the electronic device is preferably executed using a communication application activated by the phone user. [0081] There is even further provided in accordance with a preferred embodiment of the present invention a system for determining the authenticity of a product selected from a group of products, the system comprising: (i) a product tag containing information relating to the identity of the product, (ii) a database carried on a server containing details on at least some of the products in the group, and (iii) a cellular telephone programmed to communicate data between the tag and the server, wherein the phone transfers the information on the tag to the server, which confirms to the phone the authenticity of the product according to the details of the product on the database. [0086] In this system, the “at least some of the products in the group” may preferably comprise essentially all of the products in the group. The data communicated between the tag and the server through the phone may preferably be encrypted, and the data may preferably be communicated between the tag and the phone through a short range communication channel. In the latter case, the short range communication channel may be any one of a Bluetooth link, Radio Frequency Identification (RFID) channel, Near Field Communication (NFC), an Infra-red optical link, and a WiFi, WiMax or WiBree network. On the other hand, the data between the phone and the server is preferably communicated through a cellular phone network, which could operate as either one of GPRS and 3G service. Finally, the information relating to the product authenticity may preferably be displayed on the screen of the cellular phone. [0087] Furthermore, in accordance with yet another preferred embodiment of the present invention, there is provided a system for determining the authenticity of a product selected from a group of products provided by a product supplier, the system comprising: (i) a product tag containing information relating to the identity of the product, (ii) a database carried on a remote server containing details on at least some of the products in the group, and (iii) a cellular telephone programmed to communicate data between the tag and the server, wherein the phone transfers the identity information on the tag to the server, which invokes a bidirectional interrogation session with the tag through the phone, the response of the tag being used by the server to verify the authenticity of the product. [0092] In this system, the server is preferably adapted to send a challenge via the phone to the tag, such that the tag can respond to the challenge on the basis of a predetermined response associated with the tag, the response being used by the server to determine the authenticity of the product. In such a case, the predetermined response can preferably either be contained on a visible record associated with the tag, such that the user can read the response from the record and return the response to the server through the phone, or it can be generated according to preprogrammed criteria by a logic program associated with the tag, and the generated response transferred to the server through the phone. [0093] In this system, the “at least some of the products in the group” may preferably comprise essentially all of the products in the group. The data communicated between the tag and the server through the phone may preferably be encrypted, and the data may preferably be communicated between the tag and the phone through a short range communication channel. In the latter case, the short range communication channel may be any one of a Bluetooth link, Radio Frequency Identification (RFID) channel, Near Field Communication (NFC), an Infra-red optical link, and a WiFi, WiMax or WiBree network. On the other hand, the data between the phone and the server is preferably communicated through a cellular phone network, which could operate as either one of GPRS and 3G service. Finally, the information relating to the product authenticity may preferably be displayed on the screen of the cellular phone. [0094] The various embodiments of the present invention have generally been described in this application in relation to authentication use, such as for anti-counterfeiting purposes. However, it is to be understood that the same systems and methods are equally applicable for use in track-and-trace applications, and the invention as described and claimed, is not intended to be limited to either one or the other. BRIEF DESCRIPTION OF THE DRAWINGS [0095] The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: [0096] FIG. 1 is a schematic view of a Secret Set generation system and procedure for use in product authentication, according to a first preferred embodiment of the present invention; [0097] FIG. 2 is a schematic view of a system and procedure for attaching a secret set generated by the system of FIG. 1 , to a product; [0098] FIG. 3 is a schematic view of the steps of a product authentication process, using the secret sets shown in FIGS. 1 and 2 ; [0099] FIG. 4 is a schematic view of a secure tag, according to a further preferred embodiment of the present invention; [0100] FIG. 5 illustrates schematically a tag used for the execution of product authentication according to a further preferred embodiment of the present invention, using a cellular phone transmission for powering the tag; [0101] FIG. 6 illustrates schematically a method by means of which the tag of FIG. 5 communicates with the external authentication system; [0102] FIG. 7 is a schematic view of a further preferred embodiment of the present invention, whereby a dual mode tag serves both as an electronic tag and as a cellular communication tag; [0103] FIG. 8 is a schematic view of a tag which communicates with the cellular phone using infrared (IR) signals; [0104] FIG. 9 illustrates schematically a tracking/verification system constructed and operative according to a further preferred embodiment of the present invention; [0105] FIG. 10 illustrates schematically a tracking/verification system constructed and operative according to a further preferred embodiment of the present invention; similar to that of FIG. 9 but with the additional use of secondary (vendor) servers; and [0106] FIGS. 11 , 12 and 13 are schematic flow charts of alternative and preferred methods of performing the verification process using the systems of FIGS. 9 and 10 , from the product tag to the decryption server via the phone terminal. DETAILED DESCRIPTION OF THE INVENTION [0107] Though the first preferred embodiment of this invention can be executed in its simplest form using a simple single string of digits and/or letters as the secret number set, there are a number of reasons for preferred use of a more complex secret number format, as will be used below in this detailed description of preferred embodiments of the invention, where a multiple selection response number system is described. Firstly, a more complex set decreases the likelihood of unauthorized access to the system using forged or stolen number sets. In addition, the preferred embodiment described involves the purchaser's active participation in the validation process, thus increasing customer confidence in the system Thirdly, using multiple sets of response numbers, it is possible to repeat each query for a specific product that number of times for additional safety, on condition that the checking system has been programmed to allow such multiple challenge. Finally, in the event that one of the response numbers becomes known, only part of the secret number is compromised, and the set can still be used as further verification. [0108] However, it is to be understood that the invention is equally operable with simpler number sets which require simpler validation responses, as explained hereinabove in the Summary Section of this application. [0109] Reference is now made to FIGS. 1 to 4 , which illustrate the use of a first preferred embodiment of the present invention, showing a “Challenge and Response” authentication system and its parts, and preferably comprising at least some of the following components: (1) A Secret Set, 10 , that has the form of {C, R[n]}, where: C, “the Challenge”, is a string of digits & letters, preferably between 6 and 8 characters, and R, “the Response” is a vector of n numbers, where n is typically 4, and each number has a few digits, preferably from 4 to 6 digits. It is to be understood that these numbers of digits and characters are chosen for ease of use, combined with a sufficient number of unique sets, but that the invention is not meant to be limited by these particular examples. (2) A Security Server 12 , that can produce millions of Secret Sets, 10 , either by means of a generating function or by creating a predetermined database of such sets (3) A Response Server 10 , that, on receipt of C and a user selected number i, which may typically be 1 to 4, preferably performs some checks on the past use of that particular C, and then responds with R[i]. (4) An associating device that attaches one or more of the Secret Sets to the end product. Typically it is a Printing Device or a mounting device 14 that prints or mounts the Secret Set on the given product or on its packaging, and then masks it with an easily removable opaque material, such as that used in scratch-off lottery cards, so that only after the consumer scratches off the covering layer does the secret set become visible. According to an alternative and preferred embodiment, the secret-set is printed on the inside of the packaging, or contained on a package insert, or on the product itself, such that only after opening the packaging, can the consumer view the set. (5) A Call-back utility 15 , which is a utility that is used to provide access to the Response server 13 to check the authenticity of the product. It can be a phone, a PC connected to the net, a set top box that is connected to a call-back server, a barcode reader network connected to the Response Server, or any other dedicated device for these purposes. (6) A Secret Database 16 for storage of the Secret Sets 10 produced in step (2); and (7) A Tag 17 printed on the final product 18 to be authenticated, or included within or on the packaging of the final product. [0120] There are preferably three phases to the authentication process: (i) Creation of Secret Sets ( FIG. 1 .) Referring now to FIG. 1 , the Security Server, 12 , which is typically a strong PC generating large numbers of Secret Sets, 10 . A secret set may preferably take the form of a challenge number, and a response set, for instance: {as13rt, {4357, 3489, 1245, 6538}} where as13rt is the Challenge, namely the string that the user sends to the Response Server 13 . In addition to this string the user preferably sends a number K, preferably from 1 to 4, which will be used by the Response Server to decide which answer to send back to the user In the preferred example shown in FIG. 4 , {4357, 3489, 1245, 6538} is the Response. These are the four potential answers that the user will get back from the Response Server 13 . The exact answer received will depend on the value of K entered by the user. [0125] There are Two General Methods for Deriving the Responses to Each Challenge: [0126] (a) A Secure Database 16 . In this method all the numbers are pre-generated randomly, and are stored in a huge database, 16 . [0127] (b) A one-way function. In this method, only the Challenge is random and the Responses are calculated by cryptographic means. One preferred method is to have a Secret S, and to perform a one-way function such as MD5 on C & S. In other words R=F (C,S), where F is a strong, known, one-way function. The advantages of this method are that there is no need to store huge databases, and any secure device that knows the secret S, can calculate the required response. The disadvantage is that this method is based on the secrecy of S, and if by some means, S becomes compromised, the production of Secret Sets, or the provision of the correct responses to a challenge then becomes public knowledge, and hence worthless. [0128] It is possible that in certain systems, both methods for deriving the Responses are used, whereby for sites with a high security rating, use is made of a database of secret numbers, while for sites with a lower security rating, the self-generated response method is sufficient. At the end of the process the Security Server 12 , will have listed all the Secret Sets 10 in a Secret Database 16 . (ii) Associating Secret Sets With the End-Product ( FIG. 2 ) (a) The Mounting Machine 14 , selects an unused set 11 of secret numbers from the Secret Database 16 , and marks it off in the Database as used, together with some product related information, such as the date, location, type of product, etc. (b) The Mounting Machine then preferably prints the selected set onto the packaging, or somewhere on the product itself 18 , or on an insert for inclusion within the product package, together with some additional user instructions as to how to perform the authentication process. This could preferably be in the form of a tag 17 . Reference is made to FIG. 4 which shows how a typical tag could look. The shaded area on the right of the tag is the covert area, which has to be scratched by the user to reveal the data beneath. (c) According to the preferred embodiment using a package insert, the Mounting Device 14 simply prints the Secret Set inside the packaging, either directly, such as on the inner side of a cigarette box, or on a separate slip of paper that is inserted into the box. This embodiment obviates the need for the covert and scratch process. The disadvantage of this method is that the user needs to open the package in order to authenticate the product. (iii) Consumer Authentication of the Product ( FIG. 3 ) [0135] Reference is now made to FIG. 3 , which illustrates schematically a preferred procedure by which the consumer 15 , having purchased the product and wishing to authenticate it, follows the instructions on the tag and sends the challenge, C, preferably with the user selected number from the tag (as13rt,3 in the example used herewithin) to the response server 13 by means of a utility method. [0136] The user 15 can preferably use one of several ways for contacting the Response Server: (a) An Interactive Voice Response (IVR) based phone system, where the user inserts the Challenge using the keypad (b) Phone system using Speech Recognition, so that the user can simply say the challenge (c) An SMS system (d) Use of the Internet from a PC or other device (e) A Set-top Box, whereby the user inserts the Challenge and number select information via Remote (f) Dedicated terminals, similar to barcode readers, with keypads and displays, located at the point of sale of the product. [0143] The Response Server 13 looks for the value C in the Secret Set Database 16 , and preferably performs one or more of the following checks: [0144] Is the challenge in the database? Does it make sense to accept such a challenge? For instance, if the product undergoing authentication was intended, according to the manufacturer's or distributor's records, to be sold in a specific region, and the request comes from another region, or if the product has already expired—the Server can notify the relevant systems about the anomaly, and refuse to supply the response. This is done to protect against an attacker, who, by sending random numbers to the system, causes it to deny service to bona fide consumers, since those transmitted numbers will be signaled as ‘used’. [0145] Is this the first time this number is being used? The Response Server 13 will preferably answer only once per challenge. This is done to ensure that used tags cannot be reused. If the tag being questioned had been ‘used’, the server preferably notifies the consumer about the possibility that this product is not original. [0146] The server then preferably writes in the database that this Challenge has been requested together with the specific selected index number. It can also write at this stage other information, such as the date, time, geographical origin of the challenge, etc. [0147] If the consumer is entitled to receive it, the server than preferably sends the correct response 19 back to the consumer preferably via one of the methods that the consumer used to send the Challenge. [0148] According to further preferred embodiments of the present invention, the system can also be designed to operate where the Response vector comprises only a single number. The Secret Set thus comprises only two numbers C and R. Such an embodiment is simpler to use but does not incorporate the conceptual step by which the user is actively operative in determining which of several responses he will be receiving from the response server. Such active participation by the customer also decreases the danger that pirates may set up their own response site and server, to service their own cloned product tags. In such an operation, the pirates may intercept a customer Challenge call and use the single Response intercepted, out of the set of 4 Responses possible, but this will severely limit the customer trust in the Response he receives from the supposedly authentic site he accessed. [0149] In order to encourage consumer participation in authenticating products, the method can also preferably be combined with remunerative options, such as the chance to win a prize. [0150] Although the above described embodiment is based on a remote, secure response server, a stand-alone response server can also be utilized if the necessary security requirements are deployed. One preferred example is use of a system that uses the function F to generate the secret sets, and a PC or Set-top Box with a Secure SmartCard incorporating the Secret and capable of generating the response without connection to the Remote Server [0151] According to further preferred embodiments, use can be made for the identity tag of materials, such as the base paper or the ink, that, after exposure to the atmospheric oxygen, or to some other chemical trigger, become unreadable after a predefined period of time, such as 24 hours. This prevents the use of ‘old but unused’ secret sets on fake products. [0152] The system can easily be enhanced to enable multiple authentications per product. This is done by associating multiple Secret Sets with the product. [0153] The scratch-off ink printing described hereinabove is a widely known technique. It is applied to a wide range of purposes: lottery tickets, game cards, scratch-off cards, magazine inserts, raffle postcards, and promotional novelties. The scratch-off ink printing process generally involves offset printing the overall design, including the concealed part, applying varnish, and then applying silver ink by screen-printing over the area to be concealed. This print method is not generally available for food products because of the ink residue generated when the surface is scratched off. For this reason, a new printing technique has been developed known as ‘adhesive tape peeling,’ in which gravure-printed adhesive tape is used to peel off the surface ink layer. A special ink that is applicable through screen-printing to produce adhesive tapes is available as TT164SS Silver from the Toyo Ink Company of Addison, Ill., USA, allowing flexibility in smaller lot processing. The DNP America Corporation of New York, N.Y., USA has also developed a new ink that produces a residue-free scratch. As this ink contains material that is harder than a coin, the coin edge is scraped while scratching and its particles stick to the ink-printed part to show the hidden design. This is the equivalent of the penciling (Decomatte) print method that uses coins instead of pencils. [0154] Reference is now made to FIG. 5 , which illustrates schematically a tag 20 used for the execution of product authentication, constructed and operative according to a further preferred embodiment of the present invention, using a cellular phone handset. The tag is intended to be attached to products whose authentication is desired. Each tag contains a unique key. The tag 20 comprises an antenna 21 , which is tuned for reception of cellular phone transmission and is connected to capacitor 22 which is charged with power received by the antenna 21 . The tag comprises a microprocessor 23 having a power input 24 , and a short range cellular communication module 25 for transmitting data to and from a cellular phone in the vicinity, by means of Bluetooth, WiMax, WiFi or a similar system. The communication unit 25 is powered through power input 26 . Both of the power inputs, 24 and 26 receive their inputs from the capacitor 22 , which is charged from cellular reception antenna 21 . [0155] Reference is now made to FIG. 6 , which illustrates schematically a preferred embodiment of a method by means of which the tag communicates with the external authentication system. The tag 20 which receives the cellular transmission shown in FIG. 5 , is connected via a short-range communication standard such as Bluetooth, to a cellular handset 27 , which is itself connected preferably through 3g/GPRS to the internet and server 28 . [0156] In order to operate the system, special software is loaded into the cellular handset of users wishing to use the authentication system. When the user wishes to authenticate a tagged product, the authentication application in the handset is activated. The activation of the authentication application causes the cellular handset to go into a transmission mode. This can be to an imaginary number, or to a real number, but the effect of the transmission is that the antenna 21 in the tag receives the cellular signal and thus charges the capacitor 22 . Charging of the capacitor also occurs whenever the cellular handset is active, and not only when the authentication application is running. The antenna 22 is tuned to receive signals at the cellular transmission range. The capacitor is connected to the power input 24 of the microprocessor 23 and to the power input 26 of the communication device 25 . To optimize the charging effect, it may be advantageous if the user holds the cellular phone close to the product to be verified. [0157] Once powered, the tag microprocessor 23 wakes up and sends the authentication information from the tag key through the short range communication link to the cellular handset 27 . Bluetooth is currently a preferred short range communication system, but it can also be RFID, Near Field Compensation (NFC), WiFi, Wibree, Infra-red (IR), or any other form of communication. The authentication process is then commenced, such as by one of the methods described hereinabove. The authentication can be done either locally at the cellular phone handset 27 , or remotely, by the server 28 . [0158] In the case of local authentication, the system may preferably be based on a Zero Knowledge Algorithm such as the Fiat-Shamir scheme, as described on pages 9-10 of the article by G. I. Simari entitled “A Primer on Zero Knowledge Protocols”, published by Universidad Nacional del Sur, Argentina. The phone 27 then acts as the Verifier and the Tag 20 as the Prover. Both devices need to have pseudo-random-bits generators. According to this embodiment, the phone will not need to carry any specific secrets, but it will need to carry a list of revoked devices. [0159] In the simpler case of remote authentication, the Prover in the tag 20 sends its certificate to the Server 28 , initially to the cellular phone handset 22 by the short range communication link, and then from the cellular phone handset 22 to the server 28 by long range communication, such as GPRS or 3G. From the transmitted certificate, the Server knows the Tag's secret, so it can return to it a random challenge that is encrypted under the Tag's secret. The authentic Tag will decrypt the challenge and send it back to the Server as proof of its identity, while the bogus tag will not be able to do so. [0160] Reference is now made to FIG. 7 , which illustrates schematically a further preferred embodiment of the present invention, in which the tag 30 is a dual mode tag, which serves both as an electronic tag and as a cellular communication tag. As in the tag of the embodiment of FIG. 5 , the tag includes an antenna 21 tuned for reception of cellular phone transmission, and a short range cellular communication module 25 for transmitting data to and from the cellular phone by means of Bluetooth, WiFi or a similar system. In addition, the tag of FIG. 7 also includes an RFID antenna 31 tuned for RFID signals which charge the capacitor 22 when present, and an RFID communication module 32 , powered by an input 33 from the capacitor 22 . The RFID communication module 32 enables connection of the microprocessor 23 with the external world by means of an RFID link, as shown. In use, the microprocessor is programmed to check if it has received a valid RFID communication, in which case it serves as an RFID device, or if it has received a Bluetooth signal, in which case it serves as a Bluetooth device, as described in FIGS. 5 and 6 hereinabove. [0161] According to a further preferred embodiment of the present invention, as shown in FIG. 8 , the tag 34 communicates with the cellular phone using infrared (IR) signals. The tag then needs to be an active device and to contain a battery 35 . The tag includes a photoelectric detector 36 , which converts the received light signals to electrical signals which wake up the processing elements, and an emitting element, such as a LED 37 , for transmission back to the phone 38 . According to yet further preferred embodiments, the communication can be established by image processing, whereby the camera in the phone images and deciphers information on the package or the product itself. [0162] According to a further preferred embodiment of the present invention, the cellular transmission signal can be utilized to provide power for any other element associated with the phone, such as an earphone, which can thus be powered to communicate with the phone by means of a short communication standard, such as Bluetooth. This arrangement thus saves the need to provide separate power for the external device communication link. [0163] Reference is now made to FIG. 9 , which illustrates schematically a tracking/verification system constructed and operative according to a further preferred embodiment of the present invention. The system comprises three component sub-systems—the product tag 41 , a cellular telephone 42 operating as the tag reader, and the decryption server 43 . [0164] The product tag 41 is associated with the product 45 , and also preferably includes a wireless communication device 46 for linking with the cellular phone 42 , such as an RFID link, an IR link, Bluetooth, or any other short range communication method, and optionally also an encryption system 47 . [0165] Communication with the product tag 41 is accomplished using communication device 48 , which is in contact with the wireless communication device 46 of the tag 41 . The phone 42 may also preferably include a decryption application 49 for secure communication with the encryption system 47 of the tag 41 . The phone may also include a notification application 51 . A communication device 52 such as GPRS or 3G is preferably used for communicating with the authentication server 43 . [0166] The authentication server 43 preferably includes a wireless communication device 55 of any suitable type for communicating with the cellular phone, a decryption application 56 and a product data base for responding to the request coming from the cellular phone. [0167] According to a preferred embodiment, the system may operate in the following manner. The user activates the cellular phone transmission by dialing to the number providing access to the verification/tracking service and begins communication with the authentication server 43 , which thus now expects to receive a request from the phone 42 . The phone also communicates with the product tag 41 , such as by means of Bluetooth, and requests the tag's identification (ID), preferably in an encrypted message. The tag will be powered and able to respond either because of the operation of the cellular phone in the vicinity of the tag, as per the previous embodiment of this invention, or simply because of the presence of a Bluetooth transmission. The tag then sends its preferably encrypted ID back to the phone, whose application is programmed to forward it on to the authentication server 43 . This server then responds, according to a preferred mode of operation, by checking whether the product ID appears on the list of genuine products in its database, and if so, sending its approval back to the phone. According to another preferred mode of operation, based on the first preferred embodiment of the present invention, as described hereinabove, the server responds by sending a challenge back to the phone, which forwards it to the tag. The tag responds in any predetermined manner that ensures that the response to the challenge is genuine. According to one preferred embodiment, the tag includes a logic program, which can generate the appropriate response to the specific challenge sent, according to preprogrammed criteria. The tag then sends its response back to the phone, which forwards it to the authentication server for decryption and verification. If the response is verified, the server then reports back to the phone, and hence the user, that the product is authentic. [0168] According to other preferred embodiments, the system can operate without the need for the tag to send an ID, but simply by means of a challenge sent from the server. In this embodiment, the phone initially sends its request straight to the server, without the need first to interrogate the tag. In such a case, when the tag receives the challenge from the server via the phone, it adds its own ID to the response, so that once its response is verified, the server knows which product to authenticate, based on the ID which it received from the tag. These preferred methods of operation are described more briefly in flow chart diagrams in FIGS. 11 , 12 and 13 below. [0169] Reference is now made to FIG. 10 , which illustrates schematically a tracking/verification system constructed and operative according to a further preferred embodiment of the present invention. This embodiment is similar to that shown in FIG. 9 , with the exception that by the use of secondary vendor databases for storing product information on secondary servers, the manufacturer's database of products is better protected. This system preferably comprises four component sub-systems—the product tag 41 , the tag reader 42 , the authentication server 43 and the satellite servers 44 (only one is shown in FIG. 10 ), which may preferably be configured as vendor servers, each holding part of the complete product database. [0170] As with the system of FIG. 9 , the product tag 41 is associated with the product 45 , and includes a wireless communication device 46 such as an RFID link, an IR link, Bluetooth, or any other short range method, and optionally also an encryption system 47 . [0171] The tag reader terminal 42 can preferably be either a dedicated tag reader such as a piece of store equipment, or a cash register, or a user cellular phone handset. Communication with the product tag 41 is accomplished using communication device 48 , which is in contact with the wireless communication device 46 of the tag 41 . The terminal may also preferably include a decryption application 49 for secure communication with the encryption system 47 of the tag 41 . The reader may also include a notification application 51 and a communication device 52 such as GPRS or 3G for communicating with the server 43 . [0172] The decryption Server 43 preferably includes a wireless communication device 55 of any suitable type for communicating with the tag reader terminal 42 , a decryption application 56 and a communication system 57 to the vendor data base, which is located on server 44 . [0173] Vendor server 44 preferably includes a communication device 58 to the decryption server 43 , this communication preferably being accomplished over the internet system, and the vendor data base 59 . [0174] Reference is now made to FIGS. 11 to 13 , which are schematic flow charts of the methods described above of performing the verification process. FIG. 11 relates to the system of FIG. 9 , FIG. 12 to that of FIG. 10 , and FIG. 13 is a simplified method of using the system of FIG. 9 . In FIGS. 11 and 13 , the verification process proceeds from the product tag 41 to the decryption server 43 via the terminal 42 . In these procedures, the verification process is initiated by the end user through the terminal tag reader 42 , which may preferably be a cellular phone or store tag-reading equipment. At the end of the verification sequence, either the decryption server 43 or the cell phone/tag reader 42 will have a verified product ID or a verification failure. In case of a failure, the user will be notified by a message on the cellular phone or tag reader. If the verification process has succeeded, for the 4-stage embodiment of FIG. 10 , the server detects the vendor, based on the vendor identity contained in the main server database. The product ID is then sent to the appropriate vendor server 44 , which returns the information it wants to display on the cell phone or tag reader 42 . This response can be programmed to be either identification and validity of the product, which is one object of the enquiry, or any other product information which it is desired to transfer to the enquirer, or a product offer or advertisement. According to further preferred embodiments, such additional product information could include such details as the expiry date of the item, if relevant; the nutritional value, if a foodstuff; a warning if tobacco or alcohol; and dosage or precautions if a medication. Additionally, besides a simple verification message, the enquirer can be provided with further instructions relating to authenticity, such as to inspect the packaging for expiry date, or for a special code relating to verification, etc. Furthermore, information relating to the vendor itself could be included in the response, such as a refusal to authenticate any product held by a vendor or a distributor whose credit status is deficient. [0175] Referring now to the details of FIG. 11 , in step 60 , the user activates the authentication application on his phone. In step 61 , an enquiry is sent from the cellular phone to the tag to retrieve the ID of the product. In step 62 , the tag returns to the phone the product ID. In step 63 , the phone then transfers the ID to the decryption server, which, based on the ID, in step 64 returns a crypto challenge to the phone, which then applies it back to the product tag in step 65 . The tag responds to the challenge in step 66 , with a response, which is forwarded to the decryption server in step 67 . If the product is authentic, the response is verified as correct by the server in step 68 , and the verification result is sent in step 69 directly back to the phone, for displaying the appropriate message on the screen. [0176] Reference is now made to FIG. 12 , which is applicable for the system of FIG. 10 , which includes the use of vendor servers. Steps 70 to 77 are essentially identical to steps 60 to 67 of the method of FIG. 11 . At step 78 , the main server checks the authenticity of the response, and if authentic, sends the ID to the appropriate secondary server, preferably with a message as to the status of the authentication. The secondary server, in step 79 , then verifies the product's details on its database, and sends a confirmation message back to the main server, which in step 80 , returns the message to the phone, for display in step 81 on the phone's screen, this completing the authentication process. [0177] Reference is now made to FIG. 13 , which is an alternative simpler procedure for performing the verification process from the product tag, for the embodiment of FIG. 9 . In step 82 , the phone begins by contacting the server to retrieve a challenge. The server returns the challenge to the phone in step 83 , from where it is directed to the tag in step 84 . In step 85 , the tag provides a response including its encrypted ID. The phone, in step 86 forwards this response to the decryption server, where, if the response is found to be correct for the challenge, the decrypted ID is verified as valid 87 , and the verification result is send directly back to the phone for display on the phone's screen. For the embodiment of FIG. 10 , using secondary servers, the correct vendor server would be questioned for verification details of the specific product. [0178] According to yet another preferred embodiment of the present invention, there is a further method of performing the verification process, but this method is performed by the cell phone itself, without need of an intermediary server. [0179] There is a pubic modulus N [1024 bits] which is a result of multiplication of 2 secret prime numbers P & Q. [0180] From the ID (typically 5 bytes), a value V [1024 bits] is computed, which is a result of hash function like MD5 operating on ID: V=Hash (ID). [0181] The system than computes S such that S*S mod N=V a) The Cell Phone asks for an ID from the Tag and computes V b) The Tag picks a random number R [1024 bits] and send to the phone Y=R̂2 mod N c) The phone picks 0 or 1 and sends it to the tag d1) If the phone sends 0—the Tag sends back R [1024 bits], and the phone checks if indeed R̂2=Y d2) If the phone sends 1—the tag sends back Z=R*S mod N [1024 bits], and the phone checks if indeed Ẑ2 mod N=Y*V mod [0187] According to further preferred embodiments of the present invention, product information may be contained electronically in the tag and sent to the cell phone, which can than display it. [0188] It is appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes subcombinations and combinations of various features described hereinabove as well as variations and modifications thereto which would occur to a person of skill in the art upon reading the above description and which are not in the prior art. It is also to be understood that the phraseology and terminology employed herein are for the purpose of describing the invention, and should not be regarded as limiting the invention.

An authentication system enabling a customer to verify the authenticity of a product in a foolproof, secure and simple manner. plurality of secret sets of numbers is generated, each set comprising a challenge portion and a response portion. These sets are stored on a remote server. Each set is associated with a different product. The customer sends a challenge portion to the server, and prompts the server to provide a response. If the response matches that of the product in hand, the product is known to be authentic. In another embodiment of the system, cellular transmission is used to power an electronic tag attached to the product and carrying authentication data. In a third embodiment, the full manufacturer database is divided into separate databases, possibly related to product vendor, such that an authentication process can be performed without the need to access the manufacturer's entire database of products.

This application is a continuation of application Ser. No. 08/111,160, filed Aug. 24, 1993, and now abandoned, which is a continuation of application Ser. No. 07/806,084, filed Dec. 11, 1991, and now U.S. Pat. No. 5,269,309. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of medical ultrasound imaging. More specifically, it involves an imaging system which incorporates techniques first developed in the geophysical sciences for analyzing seismic traces to create high resolution medical images. 2. Description of the Related Art Well known ultrasound imaging systems commonly provide medical images for a variety of uses. In general, ultrasound imaging utilizes a sound source to ensonify a target area and a detector to receive the echo. Ultrasound can often penetrate objects which are imperious to electromagnetic radiation. However, acoustical imaging systems have traditionally produced lower resolution images than electromagnetic radiation imaging systems. The introduction of synthetic aperture focusing into medical imaging systems has helped to improve the quality of ultrasound images over previous systems which used direct focusing. The synthetic aperture focusing technique (SAFT) was originally used in radar systems to image large areas on the ground from an aircraft. In SAFT, the transmitted beam is a broad band signal which is sent out in a wide cone of transmission. The broadband nature of the transmitted signal allows direct measurement of the time of return or the phase information of the signal, thereby allowing the determination of the range of any reflectors (i.e., changes in acoustical impedance) which cause returning echoes. Moreover, the wide cone transmission beam in SAFT allows recording on one receiver channel of echoes returning from all directions. This provides information about an entire area, eliminating the need to scan the area point by point. However, since the direction from which the echoes have come cannot be determined from one receiver channel, SAFT requires the use of many receiver channels. By comparing information across all of the channels, the direction of the returning signal can be determined. This process enables focusing on a point by analyzing the receiver traces, and is thus referred to as synthetic focusing. Another advantage of SAFT is that since it does not require beam steering, there is no need for expensive hardware to drive the array. Additionally, because the wavelength of the radiation used does not limit resolution, the resolution of the images produced can be increased by many orders of magnitude over that obtained with direct focusing. Examples of ultrasonic imaging systems that use SAFT are disclosed in U.S. Pat. Nos. 3,548,642, and 3,895,381. U.S. Pat. No. 4,325,257, to Kino, et al. discloses a more recent acoustic imaging system that exemplifies typical SAFT processing. The Kino patent describes using an array of transducer elements in which each element is multiplexed in sequence to emit an ultrasonic pulse into the sample. Each transmitting element then acts as a receiver which measures and records the returning echoes. Once all of the transducer elements have obtained a time history trace of the echoes (i.e., a record of the return beam for a selected period of time), the traces are transformed into a three-dimensional image of the target using a conventional reconstruction algorithm. Each point of the three-dimensional image represents a point in the sample and contains a value which represents the strength of the reflected signal at that represented point location in the sample. Strong reflectors, such as bone, have high values at the surface. Values are close to zero at locations where there are no reflecting surfaces or objects. Once a three-dimensional image is obtained, it can be collapsed to generate any two-dimensional view of the sample using conventional tomography techniques. Typical systems display the collapsed two-dimensional view on a CRT monitor. The reconstruction algorithm disclosed in the Kino patent is based on the travel time of the echo signals. In other words, for a reflecting object at a given location in a sample, the echo returning from that reflector appears at a different time in the time history trace of each receiver channel. The algorithm involves calculating, for a specified reflector location, the return time to each receiver from that specified reflector location, and then summing across the channels all of the echoes which came from that specified location in the sample. The summing reinforces any coherent information from a potential reflector at the specified location and cancels the noise from various other random locations in the sample, leaving only the signal information which originated from the specified location. If no reflector (i.e., no acoustical impedance change) is present at the specified location, no coherent information will exist and the signals tend to cancel each other when summed. Each point location in the three-dimensional map (also known as a focus map) of the sample is calculated using this procedure. This procedure is commonly termed "migration" in geophysics, and there is a great amount of literature published about it dating back to 1954, when J. L. Hagedoorn's thesis paper entitled "A Process of Seismic Reflection Interpretation," provided the graphical foundation on which migration procedures are based. This paper can be found in Geophysical Prospecting, Volume II, No. 2, June 1954. U.S. Pat. Nos. 5,005,418, and 4,817,434, to Anderson both disclose medical ultrasound imaging systems that incorporate SAFT using a single transmitted pulse. The systems described use a transducer array having a center transmitter element and a set of surrounding receiver elements. Instead of multiplexing the receiver channels to record a set of return signals in sequence, the transmitter sends out a single pulse, and the receivers record the returning echoes simultaneously. From the recorded time-history traces, a focus map of the sample is obtained using a reconstruction algorithm. Pat. No. 4,817,434, discloses a summing algorithm similar in principle to the one described by Kino, except that all of the time history traces originate from the same transmitter. This is similar to algorithms that are used in seismic exploration which are known as migration algorithms. Pat. No. 5,005,418, discloses a reconstruction algorithm known as ellipsoidal backprojection, which differs from the procedure described in Pat. No. 4,817,434. However, the backprojection algorithm also relies on the time-of-travel principle. Because the reconstruction methods described above rely on time-of-travel calculations, calculating the correct travel time between the array elements and the reflector locations in the sample for the purpose of reconstructing the three-dimensional map of the sample requires knowledge of the velocity of sound typically through the sample. A problem that arises with both ellipsoidal backprojection and migration, which both rely on time-of-travel calculations, is that the velocity of sound varies at different locations throughout the sample. Knowledge of these velocity variations provides information needed to correctly align the receiver traces for the summing process. However, because the velocity variations are not known in advance, the reconstruction algorithms disclosed in the conventional systems rely on an assumption that the velocity of sound does not vary throughout the sample. This assumption seriously limits obtaining accurate information about reflector locations. The sound may also refract as it travels through the sample, thereby increasing the time-of-travel as well as changing the receiver location (from that expected) of the first return signal from a reflector in the sample. In general, current techniques in medical imaging do not adequately account for either of these effects. These unaccounted for realities severely degrade the accuracy and quality of reconstructed images because the coherent reflector information from any selected channel will be skewed in time from coherent information from other channels. The skew in time is caused by the velocity variations within the sample. This results in a significant loss of information when the signals are summed together because coherent information which is skewed in time will be discarded as noise in the summing process, and noise signals may be summed as coherent information. Thus, a need exists for a more satisfactory reconstruction procedure which accounts for the changes in sound velocity throughout the sample. The geophysical sciences utilize reconstruction methods in seismic imaging to accurately obtain velocity information. Determining the location of reflecting surfaces beneath the ground and identifying the various geological materials of which the strata is composed are both important in geology. A technique commonly called common depth point (CDP) stacking in seismic imaging determines the velocity of sound for different travel paths and different locations throughout the sample. The velocities provide accurate information for calculating the correct time-of-travel in the migration procedure. The velocities can also be compared with a database of velocities to identify the nature of materials at various locations. W. Harry Mayne introduced CDP stacking in 1962 in the field of seismography. (see Geophysics, Vol. 27, no. 6, p. 927). More recent uses of this method are disclosed in U.S. Pat. No. 4,992,996, to Wang, et al. SUMMARY OF THE INVENTION The present invention involves an ultrasound imaging system, particularly adapted for use in generating images of anatomical structures. The present invention utilizes a CDP analysis technique similar to that used in seismic imaging to obtain velocity functions for the sample (i.e., a map of the velocity functions in time for many points across the array, hereinafter referred to as a "velocity volume"). After the velocity functions are generated, a focus volume is obtained with a CDP stacking technique similar to that used in seismic imaging. Finally, a migration algorithm is performed which relies on the information from the velocity functions to make accurate time-of-travel calculations to locate the coherent echo signals originating from common locations. Through migration, an image field (i.e., a reconstructed focus volume) of the sample is generated which is more accurate and provides significantly higher resolution than obtained by prior art medical imaging systems. The images extracted from the image field in the present invention are of correspondingly higher quality. The velocity volume itself may be used to identify various tissue materials within the body based on their characteristic velocity signatures. For instance, an image may be generated representing velocities throughout the sample. Because the velocities relate to the acoustical impedance of the points in the volume, this information itself may be useful. For instance, if human tissue is diseased, the diseased tissue often has an acoustical impedance which differs from the impedance of normal tissue. Accordingly, anomalies in the impedance may provide valuable diagnostic data. One aspect of the present invention involves a method of imaging an organism comprising transmitting acoustic energy into a selected portion of the organism from a first plurality of locations, receiving reflections of the acoustic energy at a second plurality of locations, and reconstructing a mapping of the velocity of the acoustic energy in the selected portion with a common depth point velocity analysis of the reflections of the acoustic energy. Another aspect of the present invention involves a method of imaging an organism. The method comprises a number of steps. A burst of acoustic energy is transmitted from a transmitter located proximal to the organism, the burst being of sufficient energy to propagate from the transmitter to a selected portion of the organism to be imaged and to reflect back to at least one receiver. The signals which reflect back are sampled to obtain a set of time history recordings of the signals reflected from the selected portion, each of the time history recordings being taken at a different receiver location. The transmission and reception are repeated for a plurality of different transmitter locations to obtain a set of time history recordings associated with each of the plurality of transmitter locations. A set of time history recordings is then selected, and each of the time history recordings in the selected set is associated with a different pair of receivers and transmitters, wherein the receiver and transmitter pairs are disposed substantially symmetrically about a common surface point. The selection then repeats for a plurality of common surface points to obtain a plurality of selected time history recording sets. A set of velocity functions are then assembled associated with the common surface points. The set of velocity functions are obtained from the plurality of selected time history recording sets. The velocity functions are organized to represent a three-dimensional field indicative of the actual velocity of the acoustic energy within the selected portion of the organism. A three-dimensional field representing the reflectors in the sample is generated. This three-dimensional representation can be displayed on a three-dimensional display. Finally, a two-dimensional image is generated and displayed utilizing the three-dimensional representation of the reflectors. In one embodiment of this method, the acoustic burst is a swept frequency signal varying in frequency between a first frequency and a second frequency. Further, the first frequency and the second frequency are within the range of 1 to 8 Megahertz in one embodiment. Advantageously, the first frequency and the second frequency are related by a ratio of 2 to 1 or higher, with improved resolution obtained with ratios of 2.5 to 1 and higher. Advantageously, the duration of the sweep is sufficient at the instantaneous transmission power to inject sufficient acoustic energy during the sweep to penetrate to the desired depth in the sample and to generate return reflections having an adequate signal-to-noise ratio, as further explained herein. The total effective power injected into the sample is advantageously adjustable from sample to sample to obtain the desired image. In one embodiment, this method may desirably be used where the selected portion comprises human tissue, bone, and organs within a human body, or tissue having diseased tissue. Another aspect of the present involves a method of mapping inhomogeneities in tissue. According to this aspect, acoustic energy is transmitted into the tissue from a plurality of transmitter locations, reflections of the acoustic energy are received at a plurality of locations, and a wavefield representation is reconstructed with a common depth point velocity analysis of the reflections of the acoustic energy in order to generate three-dimensional mappings of the inhomogeneities in tissue. Still another aspect of the invention involves a method of diagnosing anomalies in human tissue. This method comprises transmitting acoustic energy into human tissue from a plurality of locations, receiving reflections of the acoustic energy at a plurality of locations, reconstructing a three-dimensional mapping of the velocity of sound in the tissue with a common depth point velocity analysis of the reflections of the acoustic energy, and comparing the velocity in the tissue with the velocity of known anomalies in human tissue. Still another aspect of the present invention involves a signal receiving system for use in an acoustical imaging system, wherein the imaging system utilizes an array having multiple transducers. The signal receiving system has an array having a plurality of transducer elements capable of functioning as receivers, and a set of receiver channels which number fewer than the number of receivers in the array. Each receiver channel in the set is assigned to a selected portion of the plurality of transducers in the array such that for any predetermined set of transducers symmetrically located about a selected transducer, wherein the predetermined sampling set of transducers equals the number of channels in the set of receiver channels, each receiver channel in the set is only assigned to one transducer in the predetermined sampling set. A switching unit selectively connects the transducers to the assigned receiver channels for any predetermined sampling set. In one embodiment, the array is conformable to the sample surface. In another embodiment, the array is substantially planar. Yet another aspect of the present invention involves a method of switching signals from a selected sampling set of transducers in an acoustical imaging system, wherein the transducers form an array, to a set of receiver channels which are equal in number to the number of transducers in the selected sampling set of transducers. This method involves a number of steps. Each of the transducers in the array are assigned to a respective receiver channel in the set of receiver channels. For any predetermined sampling set of transducers symmetrically located about a selected transducer anywhere within the array, each receiver channel in the set of receivers is assigned to no more than one transducer in the predetermined sampling set. A first predetermined sampling set of transducers is selected equal in number to the number of receivers in the set of receiver channels. The first predetermined sampling set is symmetric about a selected transducer. The first predetermined sampling set of transducers is then electrically connected to the set of receiver channels with a switching circuit, and a second predetermined sampling set of transducers equal in number to the number of receivers in the set of receiver channels is selected, wherein the second predetermined sampling set of transducers comprises a portion of the same transducers in the first predetermined sampling set. The first predetermined sampling set of transducers is electrically disconnected from the set of receiver channels with the switching circuit. Finally, the second predetermined sampling set of transducers is electrically connected to the set of receiver channels with the switching circuit. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a generalized block diagram illustrating electronic components of the synthetic aperture imaging system according to one embodiment of the present invention. FIG. 2 is an exemplary view of a sensor array positioned above a sample to be imaged. FIG. 3a and FIG. 3b are symbolic representations of the sensor array and illustrate an example of different sets of array elements used in obtaining data. FIG. 4 is a symbolic representation of the sensor array illustrating the connections between the receiver channels and the array elements. FIG. 5 is a symbolic representation of the sensor array illustrating the transducers chosen for collecting data for a radial CDP gather on a common depth point. FIG. 6 is a symbolic representation of the sensor array illustrating the array elements used for a full radial CDP gather and the concentration of possible common ground points. FIG. 7 is a graph representing a simplified radial CDP gather and illustrating how a velocity analysis is performed for a single common depth point. FIG. 8 illustrates an exemplary formulation of a velocity function for a single common depth point. FIG. 9 is a representation of a set of CDP stacked traces and illustrates how a focus volume is obtained. FIG. 10, FIG. 11, and FIG. 12 are flowcharts representing the processing of the data according to one embodiment of the present invention. FIG. 13 is a representation of a projection of a femur. FIG. 14 is a representation of a cross-section of the femur taken along 14--14 in FIG. 13. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 depicts a block diagram of the imaging system 10 according to one embodiment of the present invention. The imaging system 10 comprises a sensor array 11, a CPU 12, a keyboard 13, a switching unit 14, a pulse generation unit 16, a set of receiver channels 18, a high speed logic controller 20, and a display unit 22. In the embodiment of FIG. 1, the pulse generation unit 16 comprises a signal generator memory 24, a digital-to-analog (D/A) converter 26, and a transmitter amplifier 28. Each receiver channel 18 has a protection circuit 30, a receiver amplifier 32, an analog-to-digital (A/D) converter 34, and a sample buffer 36. The display unit 22 comprises a display processor 38, a display controller 40, and a display monitor 42. In one embodiment, the sensor array 11 comprises a set of transducer elements arranged in a substantially planar two-dimensional grid. Two-dimensional arrays are known in the art. For instance, Forrest Anderson discloses a two-dimensional array in his patents (e.g., U.S. Pat. No. 4,817,434). Linear arrays are also known in the art as disclosed in Pat. No. 4,127,034, to Lederman, et al. The array 11 may also be somewhat conformable to the sample surface. If the array 11 is conformable, the return data can be compensated to be in reference to a plane by sensing the curvature or deformation of the array from a selected reference plane. The array elements may be made of a suitable piezoelectric material as used in the art. One class of materials which can be used are copolymers which are derived from polyvinylidene fluoride (PVDF). Some of these are disclosed in Pat. No. 4,917,097, to Proudian et al. Another common material used in ultrasound sensor arrays is PZT ceramics. Use of such a material is described in detail in Pat. No. 4,325,257, to Kino. Advantageously, each element is capable of either converting an electrical signal into an equivalent acoustical signal for transmission or converting a received acoustical signal into an electrical signal. Therefore, in one embodiment, each element is symmetrically positioned in the array and may both transmit and receive sound waves to and from a sample, respectively. Using transducers that perform both functions during operation provides high resolution. However, arrays with distinct transmitters and receivers are well known in the art. Thus, in another embodiment, the algorithms may compensate for irregular spacing between the transducers, and for interlacing transmitters and receivers symmetrically or asymmetrically. In yet another embodiment, the transducers are capable of transmitting or receiving, but a transducer acting as a transmitter at any given instance is not used to receive its own signal. Common algorithms are well known in the field of geophysical imaging which account for these different array configurations. Each of the elements in the sensor array is connected to the switching unit 14 by a separate electrical connection. The pulse generation unit 16 and the receiver channels 18 are also connected to the switching unit 14. Under control of the CPU 12, the switching unit 14 demultiplexes signals output from the pulse unit 16 to any of the elements in the sensor array 11. In one embodiment, the switching unit 14 also multiplexes received signals from the elements in the array to any of the receiver channels 18. In another embodiment which requires fewer receiver channels, the receivers in the array are each assigned to a particular receiver channel 18. By assigning the receivers to particular receiver channels 18, the switching unit 14 need not be as complex, and fewer receiver channels 18 can provide the necessary receiving capabilities. FIG. 4 depicts an example of this configuration and illustrates the receiver channel assignments in an exemplary 10 by 10 array; each block represents an element in the array. The subscript numerals indicate to which receiver channel the corresponding receiver element is assigned (i.e., the `x` in R x indicates the receiver channel assigned to the marked element). In this embodiment, the switching unit 14 multiplexes signals received from the set of elements active in the array during sampling to the assigned receivers. The switching sequence is controlled by the CPU 12. This configuration is explained in more detail below. The signal generator memory 24 may comprise a random access memory and contains a sequence of values which represent the shape of the signal to be transmitted into the sample. Advantageously, the values in the signal generator memory 24 when sequenced through the D/A converter 26 result in a swept frequency signal ("chirp signal") which has a center frequency in the megahertz range (e.g., 1 to 8 megahertz is advantageous). Advantageously, the ratio between the upper and lower frequencies in the sweep is at least 2 to 1, with improved resolution from ratios of 2.5 to 1 and higher (e.g., a sweep from 2 to 5, or 3 to 7.5 megahertz). Under the control of the CPU 12, the high speed logic controller 20 sequences the output of the signal generator memory 24 such that a digital representation of the chirp signal is sent to the D/A converter 26. The D/A converter 26 converts the digital signal to an analog signal and smoothes the signal with a low pass filter (not shown). The transmitter amplifier 28 amplifies the smoothed signal from the D/A converter 26. The signal output from the amplifier 28 is then routed through the switching unit 14 to an appropriate transducer element in the array 11 which is selected as a transmitter as further explained herein. Advantageously, the duration of the sweep is sufficient at the instantaneous transmission power to inject sufficient acoustic energy during the sweep to penetrate to the desired depth in the sample and to generate return reflections having an adequate signal-to-noise ratio, as further explained herein. Increasing the sweep duration at a selected transmission power increases the acoustic energy transmitted into the sample. The total effective power injected into the sample is advantageously adjustable from sample to sample to obtain the desired image. It should be noted that transmission power maximums are regulated for acoustic imaging in humans. The instantaneous transmission power does not exceed the regulated levels. Therefore, to increase the total acoustic energy, the sweep duration is increased. Alternatively, the reflections from multiple sweeps can be summed, as well known in seismic imaging. In the present embodiment, each receiver channel 18 is capable (via the switching unit 14) of receiving the return signal from a subset of transducer elements in the sensor array 11. In an embodiment where elements in the array both transmit and receive signals, the transducers in the sensor array 11 can be connected via the switching unit 14 to the signal generation unit 16 and to the input of the receiver channels 18. Therefore, direct electrical connection between the output of the signal generation unit 16 and the input to a receiver channel 18 can exist through the switching unit 14 for an element selected to transmit. Upon transmission of a signal by an element in the sensor array 11, the transmitted signal transfers directly to the associated receiver channel 18 for the same element. The transmitter signal is typically too intense for the receiver amplifier 32 to withstand. Therefore, the protection circuit 30 is connected between the array elements and the amplifier 32 in each receiver channel 18 to filter the raw transmission signals which would otherwise pass directly to the receiver amplifiers 32. The protection circuit 30 suppresses signals with a voltage which is above a value which may damage the receiver amplifier 32. The receiver amplifiers 32 amplify signals received on the associated receiver channel 18. The resultant signals pass to the A/D converters 34 where they are sampled. In one embodiment, the sample rate is selected as at least twice the upper frequency of the swept frequency signal (i.e., commonly known as the Nyquist rate). The resulting digitally sampled signal is stored in the sample data buffers 36. Advantageously, the sample buffers 36 comprise high speed random access memories (RAM) where data can be stored sequentially at the sample rate. In the present embodiment, the logic controller 20 manages the sample buffers 36 and the sampling by the A/D converters 34. With every sample, the high speed controller 20 increments an address counter (not shown) which directly addresses the sample buffers 36. Accordingly, during sampling, the data is loaded into the data buffers 36 sequentially at the sample rate. An appropriate size of the sample buffer 36 in the present embodiment is between 2-8 kilobytes. However, the amount of storage needed for the sample buffer 36 depends upon the desired sample thickness and the sampling frequency, as further explained herein. The high speed logic controller 20 interfaces with the CPU 12, which also has memory storage (not shown). In the present embodiment, after a selected number of samples are stored in the sample data buffers 36, the contents of the sample buffer 36 for each receiver channel 18 are transferred to the CPU memory or other system memory, as further explained in the discussion of the system operation below. The transfer of information between the sample buffer 36 for each receiver channel 18 in the system and the CPU memory takes place at a frequency dictated by the slowest of the CPU memory system or the sample buffer 36. Once sufficient data is obtained to be useful, the data can be processed and displayed in a variety of ways as further explained herein. One implementation of a display unit 22 is depicted in FIG. 1. In the present embodiment, the display unit 22 displays images on the monitor 42. In the display unit 22 depicted in FIG. 1, the data may be manipulated by a display processor 38 to generate displayable information through conventional methods such as thresholding (i.e., assigning a different color based upon various threshold levels deemed of significance within the data) or grey-scaling, as is well known in a variety of imaging contexts. In the display unit 22, once the data is manipulated to provide useful display information, the data can be transferred to the display controller 40 which outputs the image on the display monitor 42. In one embodiment, the display monitor 42 is a conventional display such as a CRT display. In an alternative embodiment, the display monitor 42 is a three-dimensional display. In an alternative embodiment, the display unit 22 may omit the display processor 38. The display processor 38 is simply a specialized processor dedicated to performing calculations to generate information which is useful for display. For instance, the display processor 38 may perform the thresholding or grey-scaling and utilize a three-dimensional representation of the measured characteristics of the sample to be imaged to obtain a two-dimensional slice within the three-dimensional representation. The display processor may also adjust the viewing angle from which to view the sample as selected by a user or as incorporated in the system software. If the display processor 38 is omitted, these functions may be executed by the CPU 12. Additionally, the display processor 38 may share control over these various data manipulations for display purposes with the CPU 12. Display units similar to that depicted in FIG. 1 are well known in the art. System Operation Given the description of the basic system hardware, the system operation is now disclosed for obtaining various useful images of selected tissue in an organism. For discussion purposes, a method utilizing the system to image human tissue (e.g., bone, organs, anomalies in the human, etc.) is disclosed. To obtain an image of selected tissue, the transmitter/sensor array 11 is placed on the surface of the skin proximal to the location of the internal tissue to be imaged. FIG. 2 depicts a side view of the transducer array 11 positioned over a portion of an organism 44 such as a human body. It depicts a transmitter 48 labelled `X` and a number of receivers labelled `R` surrounding the transmitter. FIG. 2 also depicts an example of the trajectory of a transmitted acoustic signal 49 (i.e., the acoustic wavefront) and some return signals 50 within the sample 44. The sample range (i.e., the desired depth into the sample) is labelled `D` and the desired thickness to be examined within the sample is labelled `T.` In other words, during sampling, the portion of the sample of interest is that portion labelled `T.` The signals returning from the portion of the sample labelled `D` are preferably ignored. It should be noted that the portions of the sample labelled T and D are merely exemplary and that all or any portion of the sample could be imaged depending on the values selected for D and T. An intervening medium 45 which closely matches the acoustic impedance of the human body (or which matches the impedance of other tissue to be imaged) is used in order to acoustically couple the transducer elements to the sample. The acoustical impedance of the human body is close to that of water. Therefore, an appropriate intervening medium 45 may be water, or a substance with an acoustical impedance which is close to water such as hema. Preferably, an air-free seal is created between the surface of the skin, the array 11, and the intervening medium 45. Alternatively, a vacuum seal is created. This intervening medium 45 which provides a coupling interface between the array 11 prevents the sound waves from scattering. If the area of skin is sensitive, as with burn patients, PVA-gel can be used as the intervening medium 45 because this gel provides a good seal and also closely matches the acoustic impedance of the human body. FIGS. 10-12 depict the general flow diagrams according to one embodiment of the present invention. The discussion relating to the system operation continues with reference to these flow diagrams. Once the sensor array 11 is positioned properly, the imaging system 10 begins data acquisition as represented in an action block 142 of a flow diagram 140 shown in FIG. 10. In general, the data acquisition involves transmitting an acoustical signal (e.g., the swept frequency chirp) and detecting the returning echoes. This process is generally referred to as a recording. The process of data acquisition is depicted in more detail in the flowchart of FIG. 11. As depicted, before a recording is taken, the CPU 12 under software control preconfigures the system 10, as represented in an action block 148 (FIG. 11). During preconfiguration, the CPU 12 provides the parameters to the logic controller 20 regarding the time delay from the sending of the chirp signal to the point in time at which the sampling of the echoes should begin and at which the sampling should cease. The time period from beginning of sampling by the receiver channels 18 to the end of the sampling is hereinafter referred to as the "sampling window" for the recording. The time delay from the transmission of the signal from a single transmitter to the beginning of sampling (hereinafter the "depth delay") determines the starting range (the depth into the sample from the transducer array) at which the sample is being imaged. For a desired starting range D (FIG. 2) into the sample at which sampling is desired, the general formula for the depth delay time to begin recording is (depth delay)=2 D/V, where V is the average velocity of sound in the sample. Similarly, the duration of the sample window for a given thickness T which is to be imaged from the desired starting range is 2 T/V. However, it should be understood the sample window duration equation is an approximation which assumes that the signal travels perpendicular to the array and returns to the same location. As depicted in FIG. 2, some of the transmitted signal 49 returns along a path other than the path of transmission (e.g., the signals 50) and is received at receiver locations spaced a distance from the transmitter 48. The transmitted signal 49 also often refracts as it traverses through the sample rather than travelling straight. Accordingly, if an image of a particular thickness T is desired, the sampling window should be slightly longer than 2 T/V to allow the signals from reflectors within the sample thickness T to return to receivers a distance from the transmitter 49. The size of the sample buffer 36 needed to store samples for a given thickness T is given by the following equation: (buffer size)=(sample window)×(sample rate) where: sample window=2 T/V T is measured in mm, V is measure in mm/sec, sample rate is measured in samples/sec (Hertz), and buffer size is measured in the number of samples. As explained above with respect to the sampling window, the buffer size should be slightly larger than indicated by the equation to allow for the return signals to reach the receivers a distance from the transmitter. The increase needed is dependent upon the spacing of the receiver in the set of active receivers that is the furthest from the active transmitter during the particular recording. In the present embodiment, one byte is used for each sample from the A/D converters 34 using 8-bit A/D converters, as is well known in the art. Higher or lower resolution A/D converters could also be used depending upon the system configuration and characteristics. Using the 8-bit A/D converter, the buffer size equals the number of bytes of memory required. The logic controller 20 uses the depth delay information it receives from the CPU 12 during preconfiguration to activate the A/D converters 34 and the sample buffers 36 at the appropriate time to start sampling at the desired depth D (FIG. 2). The logic controller 20 uses the sampling window to continue sampling the signals from the array 11 for the desired thickness T. Preconfiguring the system also involves selecting, through the switching unit 14, the particular transducer to function as a transmitter and the set of corresponding transducers to function as receivers for the particular recording. In other words, the switching unit 14, under the CPU's control, multiplexes the output of the pulse generation unit 16 to the transducer selected as the transmitter. Likewise, the switching unit 14 connects the transducers selected as receivers to the associated receiver channels 18. Accordingly, for each recording, a set of the transducer elements in the sensor array is selected for propagation of the received signals to the receiver channels 18. FIG. 3a depicts a symbolic representation of a 10 by 10 element sensor array 11. FIG. 3a does not represent the appearance of the physical array, but illustrates one embodiment of the positioning of the array elements. Each square represents one element for a total of 100 elements, each of which can advantageously transmit or receive signals. This representation is simplified for discussion purposes. One embodiment of the present invention uses a larger array which comprises, for instance, 1,024 elements arranged in a 32 by 32 square. However, the 10 by 10 array exemplifies the configuration which could be used in a 32 by 32 array. In one embodiment, the transducers in the array are spaced on the order of centimeters. The spacing depends upon the depth at which imaging is desired and the number of receivers used for sampling around any transmitter. However, the system is very flexible with respect to the spacing of the transducers depending upon the desired sample depth. Advantageously, the receiver channels 18 selected for a particular recording simultaneously sample the return signals from the respective receivers for a single transmission. In this manner, the receiver channels selected for a single recording receive return signals from the same transmission pulse. However, data acquisition for a recording need not be simultaneous from all the receivers selected for a recording. A single transmission element could be fired multiple times in order to obtain data from one or more receivers per firing until all receivers selected for a single recording have been sampled. In other words, the same transmitter could be fired multiple times, one firing for each of the receivers in the set selected as active for the recording. If all selected receivers for a recording do not sample in parallel, the array should remain motionless with respect to the subject, and the transmission coupling between the subject and the array should remain stable. Alternatively, the system could sample from two receivers in parallel for each firing from the same transmitter, collecting calibration data from the same receiver for each transmission and collecting raw data from different receivers for each transmission. In this manner, the calibration data for each firing for a single recording is compared to compensate for any motion between the array, the coupling and the subject between firings. Any change between firings from the same transmitter results in a change in the calibration reading for each transmission. By using this calibration data, the corresponding raw sample values from a receiver can be adjusted in relationship to the sample values from the other receivers selected for the recording in order to compensate for changes between firings of a transmitter. FIG. 3a also illustrates one possible set of elements (labelled "A x ") selected from the 10 by 10 array for a single recording which is hereinafter referred to as "recording A." In this example, for recording A, element A 13 52 is the transducer selected to operate as a transmitter and elements A 1 -A 25 are selected as receivers. Advantageously, transducer element A 13 52 functions as both a transmitter and a receiver for recording A. However, as previously discussed, other configurations where A 13 52 does not function as both a transmitter and a receiver for the same recording are also possible. During preconfiguration, the CPU 12 selects routing of the chirp signal generated by the pulse generation unit 16 through the switching unit 14 to the transducer element A 13 52, and routes the signals from transducer elements A 1 -A 25 through the switching unit 14 to 25 of the receiver channels 18. With this configuration of the switching unit 14 for recording A, a chirp signal generated by the generation unit 16 is transmitted from the element A 13 52 outlined in bold in the diagram. The return signals are recorded by the twenty-five selected receiver channels which are connected during preconfiguration to the elements denoted A 1 -A 25 in a 5 by 5 square of elements around the transmitter element A 13 52. However, the arrangement of the selected receiver elements for a given recording is not limited to a square. A substantially circular arrangement is often desirable because the cone of transmission of a broad-beam acoustic signal is likely to be substantially circular. The entire array of receivers is not generally used for each recording because the most acceptable reflection signals return to receivers located closest to the transmitter. Selecting the receivers from which to obtain samples of the return echo signals involves a number of considerations such as the signal-to-noise ratio and the angle between the incident and reflected signals with respect to the reflectors in the sample. With respect to the signal-to-noise ratio, at some distance from the transmitter, the signal-to-noise ratio is too small to obtain useful information from the return signal. For instance, assuming that two channels have coherent signals S 1 and S 2 , they can be summed in phase to produce a signal S 1 +S 2 which has the same shape as the original signals. Both signals, however, have incoherent noise levels N 1 and N 2 respectively. Assuming that the noise signals are not correlated, they tend to add orthogonally, so that the resulting noise level of the summed signal is (N 1 2 +N 2 2 ) 1/2 . Thus the signal-to-noise ratio of the two channels before summing are S 1 /N 1 and S 2 /N 2 and the signal-to-noise ratio after summing is (S.sub. +S 2 )/(N 1 2 +N 2 2 ) 1/2 . As channels are summed together, the total signal-to-noise ratio becomes the sum of the signals divided by the square root of the sum of the squares of the noise levels over all channels, assuming the desired signals are coherent. Channels with low signal-to-noise ratios tend to lower the overall signal-to-noise ratio of the summed signal, and should therefore not be used in the sum. Since the receiver channels around the transmitter generally have the highest signal-to-noise ratios, these are chosen for summing. The maximum distance from the transmitter for an acceptable signal-to-noise ratio increases with the power output of the transmitter and decreases with the attenuation constant of the medium through which the signal travels. The signal-to-noise ratios also decrease with the distance that the signal has travelled through the medium. Accordingly, the signal-to-noise ratio decreases at a single receiver as time progresses. The selection of receivers also depends upon the angle between the incident signal upon a reflector and the reflected signal from the same reflector in the sample. The intensity of the transmitted beam decreases with the increasing angle from the normal to the sensor array 11. Moreover, the reflection coefficient changes and mode conversions begin if the angle is too great. Generally, the angle between the incident signal and the reflected signal should be small enough to prevent significant changes to the reflection coefficient and to minimize any mode conversion in the signal, as well known in the geophysical sciences. The angle should also be small enough so it does not affect the strength of the signal significantly. A common guideline is for the angle between an incident broad-beam signal and the reflected signal from a single reflector not to exceed 30°-45°. Because of the number of factors affecting the signal-to-noise ratio and the selection of the receivers in general, determining which receiver channels are "good" channels is best done experimentally using reflectors at known locations. The signals can then be measured directly and a suitable set of receivers can be determined using the factors described above. FIG. 3b illustrates the element configuration for a separate recording, hereinafter referred to as recording B. The selection of elements for recording B as shown in FIG. 3b is similar to the configuration for recording A (i.e., a 5 by 5 square). However, the elements selected, labeled B 1 -B 25 are from positions in the array one element to the right of the elements denoted in FIG. 3a as elements A 1 -A 25 . As with recording A, one element is designated as a transmitter for the recording. For recording B, element B 13 53 is designated as the transmitter. Because not all of the receivers in the array are used at the same time, it is not necessary to have a separate receiver channel 18 for each element in the array. A system having a receiver channel for each receiver in the array would simply require more hardware. For a system which does not have a receiver channel for each receiver in the array, and which samples the receivers selected for a given recording simultaneously, the number of channels needed is the maximum number of receiver channels which are used in any single recording. For the array shown in FIGS. 3a and 3b, only twenty-five receiver channels are needed. For each recording, the receivers are selected by the switching unit 14 under the CPU's control as previously explained. In the present embodiment, each receiver channel 18 is assigned to a set of elements in the array. The switching unit 14 then routes the receivers selected for a recording to the appropriate assigned receiver channels. In this manner, for every possible recording, only one of the elements assigned to each receiver channel is being used. FIG. 4 represents one embodiment of the element/receiver-channel configuration according to this switching scheme for an imaging system with twenty-five receivers selected per recording. The elements are labelled with the symbols R 1 through R 25 . The subscript numerals indicate to which of the twenty-five receiver channels 18 the respective receiver elements are assigned. For this example, there are four array elements assigned to each receiver channel because there are twenty-five receiver channels to service 100 elements. For example, the four elements assigned to receiver channel R 12 are shaded in FIG. 4. With this assignment of receiver channels, for any 5 by 5 square matrix of elements, all twenty-five receiver channels are used, although the receiver channel assignments correspond to different positions in the 5 by 5 matrix. Furthermore, for any 5 by 5 square matrix of elements selected in the array depicted in FIG. 4, no receiver channel 18 will have more than one assigned receiver in that 5 by 5 matrix. A typical 5 by 5 matrix for a recording is outlined in bold in FIG. 4. In the embodiment depicted in FIG. 4, since only four elements are assigned to each receiver channel, the switching unit 14 requires only a 4 to 1 multiplexer for each receiver channel 18. This switching scheme reduces hardware costs over a more conventional methods such as multiplexing each receiver channel to every element in the array. The reduced channel switching scheme may also be generalized to an array with any number of elements and a system with any number of receiver channels, as long as the number of elements selected for any recording does not exceed the number of receiver channels in the system. Once preconfiguration (action block 148, FIG. 11) for a recording, such as recording A, is complete, the CPU 12 sends a message to the logic controller 20 to begin the recording. The high speed logic controller 20 sequences the signal generator memory 24 to generate the swept frequency signal at the output of the signal generation unit 16. The selected transmitter sends the chirp signal, as represented in an action block 149 (FIG. 11). Next, the system waits for the depth delay period before beginning sampling, as represented in an action block 150. The system then begins sampling, and continues for the duration of the sample window, as represented in an action block 151. During the sampling, the receiver channels 18 under the control of the high speed controller 20 continually sample the signals from the receiver elements which have been selected during preconfiguration of the system. As previously explained, this involves sequentially storing the samples from each A/D converter 34 into the respective sample buffers 36 for the duration of the sample window. The receiver channels 18 execute this operation under control of the high speed logic controller 20. The high speed logic controller 20 signals the A/D converter 34 to sample the amplifier 32 output signal at the sampling rate and also controls incrementing of the address counter and the write signals for the sample buffers 36 in order to store the digital value from the A/D converter 34 in the sample buffers 36, as previously explained. Once the samples are complete, the high speed logic controller 20 disables sampling for the recording. After a recording is taken, the recorded data is located in the sample buffers 36 of each of the receiver channels 18 which were selected for the recording. The data from the sample buffers 36 is then transferred to additional memory, for instance, the CPU memory, and maintained for further processing. This is represented in an action block 153 (FIG. 11). After a recording is completed, the CPU 12 reconfigures the switching unit 14 for the next recording (i.e., the CPU 12 sets the active transducer elements and then proceeds with the next recording, and so on). Ideally, a recording should be taken for every potential transmitter element in the array. However, even a recording for one transmitter provides some information. Therefore, the number of recordings may be reduced in order to increase processing speed. If recordings are not taken for all potential transmitters in the array, the recordings taken are preferably spread across the entire array. The reason for this will be apparent upon the further explanation below. Before an image for the sample is constructed, a series of recordings is generally taken in which each recording originates from a different transmitter and a different set of receivers surrounding the selected transmitter. Advantageously, each of the recordings is stored separately, at least temporarily, in system memory. However, mass storage devices (e.g., hard disk drives) may also be used at the expense of processing speed. Each recording comprises a set of time history traces of the returning echo signals, one trace for each receiver, and each recording corresponds to a different transmitter element. The relative position of each receiver with respect to the source element is maintained with each recording. Once some (as few as two) recordings have been taken, as represented by a decision block 154 in FIG. 11, data processing and analysis can begin, as represented in an action block 144 (FIG. 10). In one embodiment, all the recordings from the array 11 could be taken before processing. However, once more than one recording has been taken and transferred to system memory, further data processing can begin. The steps involved in data processing and analysis are further represented in the flow diagram of FIG. 12. First, a number of preprocessing steps are performed on the recordings. The first step is signal correlation (represented by an action block 156), a process well known in the art (also often referred to as deconvolution). As is apparent, each recording contains a number of time history receiver traces representative of the echoes received during the sampling window by the corresponding receivers. Each of the receiver traces in each recording is correlated with the original chirp signal that was transmitted. Since the autocorrelation function of a chirp signal is a narrow pulse, the correlation process collapses the chirp echoes into pulses, making the return time of the echoes easy to determine. The actual return time of a reflection can be located by finding a peak in the results of the correlation function; however, the summing algorithm, as explained further herein, eliminates the need to explicitly search for these peaks. After the correlation is performed on the traces, a number of other pre-processing steps may also be performed to remove effects which are associated with the sensor array. For example, the frequency response of the transmitter and receiver transducer elements, which may distort the chirp signal, may be deconvolved from the signal. This deconvolution is a conventional filtering process which is known in the art. Both the transmitters and receivers will also have variations in their responses which depend on the angle at which the acoustical signal was transmitted or received. These variations may be accounted for by varying the gain of each receiver amplifier in accordance with the computed angle between the reflected signal and the transmitted signal. In the present embodiment, this is done by the software program by multiplying the return signals by appropriate scaling factors. Corrections can also be made to compensate for the attenuation arising from the amount of time that the signal travelled through the sample. This would be done by multiplying the return signals by a scaling factor which increases as the time of return of the echoes increases. The outcome of the pre-processing is that the return data represents a substantially zero-phase, symmetric signal response to the sample. These pre-processing operations are represented in an action block 158. After pre-processing a velocity volume is generated in memory. The velocity volume comprises a set of velocity functions in time for each surface point on the sensor array. In geophysical applications, a surface point is commonly referred to as a common depth point CDP, and is hereinafter referred to as a surface CDP. These surface CDPs are also known as common ground points or CGPs. FIG. 5 shows a representation of the array with a selected surface CDP 58 marked by an `x`. The first step in obtaining a velocity volume is to perform a radial common depth point (CDP) gather for each surface CDP, as represented in an action block 160 (FIG. 12). To perform the CDP gather, the surface CDPs undergo the following analysis. From each recording, receiver traces are chosen which originate from receivers which are symmetrically located across selected surface CDPs from the transmitter element for that recording. For instance, FIG. 5 depicts the selected surface CDP 58. The location of the source transmitter 52 for recording A (shown in FIG. 3a) is marked `A s `. The receiver from recording A that is symmetrically located about the selected surface CDP from A s is the receiver 54 labelled `A 23 .` Similarly, the transmitter 53 source location for recording B is marked `B s ` and has a corresponding symmetrically disposed receiver 56 labelled `B 21 ` as shown in FIG. 5. The source-receiver pairs (e.g., A s :A 23 and B s :B 21 ) symmetrically located about each selected surface CDP are located for each recording that contains such a pair. A set of source-receiver pairs around the selected surface CDP 58 shown in FIG. 5 is illustrated in FIG. 6. The corresponding source and receiver pairs for the CDP 58 shown in FIG. 6 are referenced with the same letter. There are two of each letter because the source and receiver can be interchanged. In other words, for two letters that are the same, no designation is made as to which one functions as the transmitter and which functions as the receiver at any given time because they are interchangeable. Also, no letter is shown for the pair where the source and receiver both lie on the selected surface CDP. Thus, a total of 25 source-receiver pair combinations are illustrated in FIG. 6. However, it should be noted that using a 5 by 5 square of receivers for each recording with the transmitter located in the middle of the 5 by 5 square, only nine source receiver pair traces can be obtained around the surface CDP 58 shown in FIG. 6. The nine traces correspond to two traces from the source-receiver pairs labelled A, B, C, and D, and one trace for the source receiver pair at the surface CDP. Traces for the remainder of the source-receiver pairs (E through L) could be obtained from recordings having a wider range than a 5 by 5 square of receivers. For instance, if a recording was taken with the transmitter located at one of the H's, the 5 by 5 square of receivers around the transmitter would not encompass the other H. A 9 by 9 recording square would be required to obtain a recording which had the transmitter located at one H and a receiver within the 9 by 9 square located at the other H. Accordingly, the extra recordings E through L, which have been included for illustration purpose, would originate from recordings having a wider range than the 5 by 5 square (e.g., a 9 by 9 square or larger) of receivers. A representation of twenty-five exemplary receiver traces chosen for the particular surface CDP 58 shown in FIG. 5 are depicted in a graph 100 shown in FIG. 7. One axis 102 of the graph, denoted by t, represents the time at which the signal reached the receiver element. The other axis 104, denoted by x, represents the distance between the source and receiver in the recording from which the traces 106 originated. The traces 106 are represented in system memory and are advantageously identified and accessed according to the recording and receiver element from which they originated. The graph 100 is referred to as the radial CDP gather since the source-receiver pairs are located radially around the CDP. The letters A through L representing the source-receiver pairs in FIG. 6 are shown in FIG. 7 at the bottom of the graph 100. Traces originating from source-receiver pairs which are the same distance apart, i.e., have the same x-value, are summed together before they are entered into system memory for the radial CDP gather. The trace 103 for the coincident source-receiver pair at the location of the surface CDP is plotted at x=0, along the t axis 102. This is because the source and receiver are at the same location. The next step in creating the velocity volume is to perform a velocity analysis on the radial CDP gather 100, as represented in an action block 162. Theoretical models and experimental evidence have shown that echoes originating from a common reflector at a given location within the sample will lie approximately along a hyperbolic curve across the traces in the radial CDP gather. Additionally, the apex of the hyperbola lies at x=0, as depicted in FIG. 7. The path that a sound wave travels from a source to a reflector in the sample and back to a receiver is the same path that it would take if the source and receiver were interchanged, only in reverse. Therefore, the arrival time of the echo on the CDP gather is symmetric around x=0, or around the trace for the coincident source-receiver pair. The coincident source-receiver pair also corresponds to the least time path to and from the reflector for all of the radial pairs. It should be noted that the reflector may not necessarily be located directly below the surface CDP since it is possible that the first reflection to return may not have traveled along a straight path because of refractions within the sample, but the symmetry in the arrival time still holds. If an echo from a reflector reaches the first receiver at time T 0 on the x=0 trace 102, then the arrival time T x at which an echo from the same reflector appears on one of the other traces 106 is given by the equation: T.sub.x.sup.2 =T.sub.0.sup.2 +(X/V.sub.stacking).sup.2 where X is the source receiver separation and V stacking is the velocity along the path of travel of the sound signal from source to reflector to receiver. The stacking velocity defines the curvature of the hyperbolic curve represented by this equation. Those skilled in the art will understand that V stacking provides a velocity value through the sample. This velocity value is referred to as the stacking velocity in geophysical applications such as seismic imaging. In the example depicted in FIG. 7, the velocity analysis is performed by searching through the radial gather 100 along various hyperbolic curves (e.g., hyperbolic curves 108, 109, 110) with apexes at x=0. Many other hyperbolic curves in addition to hyperbolic curves 108, 109, 110 would also be searched. An arrival time T 0 is chosen, as shown in FIG. 7, and a hyperbola with a given curvature, or stacking velocity, is also chosen along which to search. The values on all the receiver traces along the chosen hyperbola are compared to other trajectories (e.g., cross-correlated or summed with other receiver traces to find the largest coherent values, as well known in the art). If the data along the hyperbola is highly coherent, the sum produces a high value. The curvature of the hyperbolic curve which results in the highest coherency is taken to represent the stacking velocity at arrival time T 0 for the surface CDP. The determination of velocities at all desired arrival times results in a velocity function with respect to time, depicted in the graph 112 of FIG. 8. In other words, the graph 112 depicts a velocity function 118 in time for a single surface point. Each point in the graph 112 represents a selected hyperbolic curve from the CDP gather. One axis 114 of the graph 112 represents the location of the apex of the hyperbola on the time axis 102 of the CDP gather 100 in FIG. 7. This can be thought of as the arrival time of a reflected signal from the coincident source-receiver pair at x=0. The other axis 116 represents the curvature of the hyperbola, or equivalently, the stacking velocity. The coherency of each summed hyperbolic curve is represented on the graph 112 by the peaks seen in the direction of increasing arrival time. The dotted curve 118 represents the velocity function, or the best velocity value at each arrival time, which is the peak of the coherency curve along the velocity axis 116. The velocity V 2 from FIG. 7 is chosen as the best velocity at time T 0 because it has the highest coherency. It should be noted that the three hyperbolic curves 108, 109, and 110 of FIG. 7 only provide the points on the T 0 trace indicated by dotted lines labelled V 1 , V 2 , and V 3 . Therefore, as previously explained, many additional hyperbolas are summed to obtain the remainder of the T 0 trace, as well as the other traces in the velocity function graph 112. Multiple coherency peaks may occur due to reverberations and multiple reflections from the sample, but these can be separated from the initial reflections using simple logical inferences about the sample. In other words, certain properties about the sample are generally known. Knowledge of these properties can be used to separate signals containing accurate information from signals representing propagation artifacts such as reverberations. For instance, if the sample is a part of the human body known to have a single bone and returning reflections indicate the presence of two bones, the extra signals can generally be separated as reverberations or propagation artifacts. Preferably, the CDP gather and velocity analysis are performed to obtain a velocity function (velocity with respect to time) for every surface CDP in the array. Therefore, each surface CDP in the array will have a corresponding velocity function similar to that represented in the graph 112 (FIG. 8). The combination of the velocity functions for each of the surface CDPs results in a velocity volume with each surface CDP location having a velocity function as a function of time. This velocity volume is represented in system memory as velocity functions in time for each surface CDP. The time functions are stored with reference to the position (X,Y) across the array 11 of each surface CDP. Moreover, because the functions are time functions, as seen in FIG. 8, the values in the velocity volume are accessed in reference to the spatial position (X,Y) and the time (t). Surface CDPs can be located not only at the center of a transducer element, but also halfway between elements and at the corners of four adjacent elements. An example of the surface CDPs for a portion of the array 11, are marked by a set of `x's 120 in FIG. 6. Radial source-receiver pairs can be found around all of these points. Since the stacking velocity is an average, it does not change dramatically across the velocity map. Thus, once the velocity volume is calculated for a preliminary set of surface CDPs, the values in the velocity volume may be interpolated to find the stacking velocity value beneath any location on the sensor array. The velocity volume gives general low resolution information about the reflectors in the sample, and therefore, can be interpreted. For instance, if the sample is a portion of the human body with known characteristics, and the velocity volume differs significantly from the known characteristics, the anomalies in the velocity map may provide valuable diagnostic information. In one embodiment, the velocity volume can be used in conjunction with a database to identify the particular types of tissue within the sample. The data base is created by performing the velocity analysis on known sample materials and recording the signatures of these materials within the velocity volume that is obtained. Statistical pattern matching may then be used to identify materials in an unknown sample. A two-dimensional slice through the velocity volume can also be displayed, using conventional methods such as grey-scaling or thresholding, as depicted in a decision block 163, and an action block 164. Alternatively, a two-dimensional projection through the velocity volume can be displayed, as well known in the geophysical sciences. Along with the velocity volume, the CDP gather 100 of FIG. 7 is used to create a CDP stacked trace for each surface CDP. A stacked trace is a single time history trace for a particular surface CDP and contains the maximum coherency value associated with the velocity chosen from the velocity map. For example, at time T 0 marked on the graph 100 in FIG. 7, the best velocity value was chosen to be V 2 because the sum across the traces 106 along the hyperbola 109 corresponding to V 2 yielded the highest value. This sum is plotted as the CDP stacked trace value at arrival time T 0 . It is called a "stacked" trace because all of the traces 106 from each of the source-receiver pairs are collapsed into a single trace located at x=0 (directly below the surface CDP) by summing or stacking them together. This step is represented by an action block 165 in FIG. 12. Advantageously, CDP stacked traces such as the representative traces 121 are obtained for each surface CDP spatial position on the sensor array 11. The stacked traces are stored in system memory with reference to the associated spacial position and time. The compilation of stacked traces in memory for each surface CDP is referred to as a focus volume. The graph 122 of FIG. 9, is an exemplary representation a number of stacked traces 121 stored in memory. The representation 122 a Y axis 124 and an X axis 126 representing the spatial surface position on the sensor array and a t axis 128 representing the arrival time of the signals in the CDP stacked traces 121. In one embodiment, the focus volume is stored in a three-dimensional array configured in computer memory and accessed with respect to X, Y, and t. Each cell in the array contains a value representing the amplitude of the stacked trace at that point in time. Therefore, in essence, the focus map has four dimensions-the x position, the y position, the point in time, and the amplitude of the trace at that point. CDP stacking is known in the geophysical sciences as disclosed by Wang, et al in U.S. Pat. No. 4,992,996. As in the CDP gather, the reflections returning from a point reflector at a given location in the sample appear on several adjacent CDP stacked traces in the focus volume along a hyperbolic curve 130. Since the sensor array 11 is substantially two-dimensional, the hyperbolic curves in the focus volume take the form of a three-dimensional hyperbolic surface, or hyperboloid of revolution. Only the traces 121 in a single slice of the focus volume are shown in FIG. 9. The density of the traces has also been reduced for clarity. In practice, there would be one trace for every surface CDP on the array 11. From the focus volume 122, a three-dimensional image field of values can be formed by summing along the hyperboloid curves 130 at every CDP stacked trace in the focus volume 122. This step, represented in an action block 166 (FIG. 12), is known in geophysics as migration and results in the reflections being more focussed and in more correct spacial positions. If depicted in graphical form, the results of the migration would have a similar representation to the representation depicted in FIG. 9, except that the values would be more accurate. Accordingly, the image field, in essence, also has four dimensions--the X and Y spacial position of the associated CDP for the traces, the time, and the amplitude at that time. To further illustrate the migration step, suppose a given point in the sample is given the coordinates (x,y,z) where x and y are the coordinates of the surface position on the sensor array beneath which the point is located, and z is the depth. The arrival time is calculated for a reflector at depth z using the information from the velocity map obtained previously. The apex of the hyperboloid curve is assumed to be directly beneath the surface location (x,y) and at the arrival time which corresponds to depth z. The location of the apex of the hyperboloid corresponding to the sample position (x,y,z) can then be represented by the coordinates (x,y,t) in the focus volume 122 where t is the arrival time on the CDP stacked trace below the surface point (x,y). During this phase of the image reconstruction algorithm, it is assumed that the least time path from a reflector to the surface is a straight path which is perpendicular to the sensor array at the surface. For most situations, this assumption does not significantly affect the image reconstruction. As previously explained, the value in the velocity volume are also accessible by reference to X, Y, and t. Therefore, once the apex of the hyperboloid (x,y,t) is located, the curvature is determined from the stacking velocity located at the corresponding point in the velocity volume in memory. The arrival time T R of the echo signal from a possible reflector on an adjacent CDP stacked trace 121 can be found by a similar equation to that used in the velocity analysis, namely: T.sub.R.sup.2 =T.sub.0.sup.2 +(R/V.sub.stacking).sup.2 where T 0 is the arrival time at the apex of the hyperboloid, R is the distance along the surface between the CDP stacked trace at the apex and the stacked trace at which the arrival time T R is being determined, and V stacking is the velocity from the velocity volume which corresponds to the location (in terms of x,y, and t) of the apex of the hyperboloid. If the apex point (x,y,t) is not directly below a surface CDP, the velocity is obtained by interpolation within the velocity volume. When the curvature is determined, the values along the hyperbola with the identified apex location and curvature are summed together in the same fashion as in the CDP gather. If a reflector is located at the chosen position (x,y,z), the summed values are coherent and result in a large overall value. If no reflector is located at the chosen position, the summed values represent incoherent noise and result in a small value. Stronger reflectors produce higher coherent values simply because more energy returns from strong reflectors. It should be understood that the representation 122 of the focus volume is significantly simplified from a focus volume stored in memory of a sample with a large reflector within the sample. The focus volume 122 essentially depicts two point reflectors in the sample. For instance, if the sample was a part of the human body with bone within the sample area, the interface between the bone and the surrounding tissue would cause coherent reflections from many (x,y) positions and at substantially the same point on the t axis 128 in the focus volume 122. Through interpolation within the focus volume 122 to find the apex of the hyperboloids in the volume, a very high resolution image can be obtained. For instance, in the example explained above with a human bone within the sample, the apexes of many of the hyperbolas combined indicate the reflecting surfaces. Moreover, the value obtained by summing along the hyperbola provides further information about the reflectors, as previously explained. Assuming that a sufficiently high sample rate is used for the initial recordings, the resolution is limited by the pulse width (i.e., duration), the pre-processing step mentioned above. Since two reflectors located closely together can only be distinguished if the pulses returning from each do not overlap, with a transmitted acoustic chirp in the megahertz range, it is possible to achieve a resolution on the order of microns by such wavefield reconstruction. Once a three-dimensional image field has been reconstructed through migration, it can be collapsed into a two-dimensional image (as represented in an action block 168) (FIG. 12) for display on the display monitor 42 (represented in an action block 169. One possible method to collapse the three-dimensional image field into a two-dimensional image is through tomography and is well known both in the art of seismic imaging and medical imaging. A representation of a tomographic view of a femur 200 is depicted in FIG. 13. A tomographic algorithm for a medical imaging system is disclosed in U.S. Pat. Nos. 4,817,434, and 5,005,418, to Anderson, which are incorporated herein by reference. In the present embodiment, the tomographic algorithm may be performed by the display processor 38. The three-dimensional volume is sent to the display processor 38 along with a desired viewing angle supplied by the software program or by the user. The display processor 38 computes the pixel values by summing the coherency values along the line of sight of the desired view and converting the summed values to corresponding grey-scale values or color values using thresholding techniques, as well known in the art. The grey-scaled or thresholded image is displayed on the monitor 42. The pixel values are then accessed by the display controller 40 and output to the monitor 42 for viewing. It is possible for the CPU 12 to execute the display processing in order to reduce hardware costs, but this would slow down the processing time. A slice through the image field can also be displayed through grey-scaling or thresholding the values in the slice, as well known in the art. Any slice can be imaged. For instance, a slice for a selected time value, or a slice for a particular X or Y value in the field could be taken. FIG. 14 depicts a representation of a slice of the femur 200, which could be obtained by taking a slice through the image field. Alternatively, with a three-dimensional display 42, the three-dimensional image field (or other three-dimensional representation) could be displayed directly. As explained above, the stacking velocity is an average. The velocity of the acoustic signals within the sample at different intervals (the "interval velocities") can also be calculated. Calculating interval velocities is well known in the geophysical sciences. One common method to estimate the interval velocities throughout a sample is through the "DIX" equation, as well known in the art. See, Dobrin, Introduction to Geophysical Prospecting, p. 244, Fourth Edition, McGraw Hill Book Co. 1988. According to the present invention, the interval velocities within an organism can be calculated, as represented in an alternative path in the flow chart 144 by a decision block 170 and an action block 171. The interval velocities are useful if the velocity at a particular point within a sample is desired. For instance, a velocity within particular tissue which differs from the expected velocity may be useful in diagnosing the character of the anomaly in the tissue. In the medical field, the two-dimensional images which are displayed would generally be examined by the attending physician. However, because certain properties are known about human tissue, the computer system could execute a variety of different analyses to aid in the interpretation of the images. For instance, in one embodiment, the attendant could select any given point in the sample for analysis by the computer. The computer could calculate the interval velocity at that point and compare the measured velocity to a data base of velocities associated with different anomalies. For instance, if the velocity of a given cancer is known, and the interval velocity for the portion selected by the operator matches the known velocity of the cancer, the computer could easily identify the particular cancer as one possible source for the anomaly. The interpretation of the images for diagnosis is depicted in an action block 172. There are various enhancements that can be incorporated into the present invention to increase the processing speed. Increasing the speed allows for a faster image frame generation, and therefore, allows a real-time image simulation. One enhancement that may be incorporated is a pipelined processing architecture. Such an architecture could advantageously utilize a set of CPU's, one for each pipeline stage, thus allowing the various stages of processing to be performed simultaneously. The stages that are easily separated are the data acquisition, signal correlation, signal pre-processing, the radial CDP gather, the velocity analysis and CDP stacked trace formation (done simultaneously), the migration algorithm, and the display image projection. Each of these stages transforms the data into a separate format. Therefore, pipelining each of these stages is possible. Another way to increase speed is to create dedicated hardware units which take the place of software steps used in the processing of the data. Processing steps which are relatively easy to develop as hardware units include the signal correlation, the signal pre-processing, the CDP stacked trace formation, and the image projection which has already been represented as the display processor 38 in FIG. 1. Another option that can be used to speed up the data acquisition step is to transmit more than one signal simultaneously and thereby take more than one recording at a time. In this option, a small set of transmitters is chosen and chirp signals with different signatures are transmitted from each. When the echoes are recorded, the information from each transmitter is separated during the correlation process by examining the different chirp signatures. This option would require more receiver channels as well as some additional hardware for the pulse generation unit to accommodate simultaneous transmission of signals. Although the preferred embodiment of the present invention has been described and illustrated above, those skilled in the art will appreciate that various changes and modifications can be made to the present invention without departing from its spirit. Accordingly, the scope of the present invention is deemed to be limited only by the scope of the following appended claims.

An acoustical imaging system for producing high resolution medical images provides a method and apparatus for obtaining accurate velocity characterizations of samples within the human body, and for obtaining high resolution images of the samples by utilizing the velocity characterizations of the samples within the human body. The acoustical imaging system also provides a method and apparatus for efficient use of switching channels whereby for a transducer array having a plurality of transducer elements, a set of receiver channels which number less than the number of transducer elements in the array are assigned to a selected portion of the plurality of transducers in the array, wherein for any predetermined set of transducers symmetrically located about a selected transducer, the predetermined set equal in number to the number of receiver channels in the system, each receiver channel in the set of receiver channels is only assigned to one transducer in said predetermined sampling set.

RELATED APPLICATIONS [0001] This Application is a Divisional Application of U.S. patent application Ser. No. 11/372,203 filed on Mar. 10, 2006. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a positioning apparatus and a positioning method. [0004] 2. Description of the Related Art [0005] A positioning apparatus for detecting (positioning) a position of itself (for example, [Latitude, Longitude], or a position on a map) is known. For example, Japanese Laid Open Patent Application (JP-P 2004-239803A) discloses a technique of a position detecting terminal and a position detecting system. This position detecting terminal has a map storing unit for storing map information, a map area specifying unit for inputting a displaying range of the map information, a position detector for obtaining position information of the terminal itself, and a display that can display the position information and the map information. This terminal has a positioning starter for activating the position detector when the displaying range of the map information is specified narrower than the displaying range indicated by a preset positioning operation start level. FIG. 8 is a block diagram showing this position detecting terminal T. [0006] This position detecting terminal executes the positioning by the procedure as described bellow. At first, the user uses an input unit and inputs a schematic position and a displaying range of a map to a map area specifying unit 102 . The specification of the schematic position is exemplified by the specification of a nearby station name or the like. The map area specifying unit 102 refers to a map storing unit 101 and displays the map and the schematic position on a display 104 . When the user requests the narrower range or requests the detailer map in the first range specification, a positioning starter 105 uses a position detector 103 and carries out the positioning. When there are a plurality of position detectors 103 , a positioning method (any of a GPS positioning unit 103 a and a wireless base station usage positioning unit 103 b ) corresponding to a specified positioning precision is selected to carry out the positioning. The detailer map is obtained correspondingly to the positioning result. [0007] In the example of Japanese Laid Open Patent Application (JP-P 2004-239803A), the positioning method is changed correspondingly to the specified displaying range. For example, if the specified displaying range is the displaying range stored in advance in the map storing unit 101 such as a wide area map, the positioning is not especially executed. When the displaying range becomes detailer, the positioning is executed. As the displaying range becomes detailer, the accuracy of the positioning is enhanced. As a result, the more accurate position information corresponds to the detailer map. [0008] However, after the positioning of the low precision is executed to obtain the position information, when there is the input of the user requesting the detailer position information, the repositioning of the high precision is required. In this case, in addition to the time necessary for the positioning of the low precision, the time necessary for the input operation of the user and the time necessary for the positioning of the high precision are required successively and excessively. Thus, the satisfaction of the user is decreased. SUMMARY OF THE INVENTION [0009] It is therefore an object of the present invention to provide a positioning apparatus and a positioning method that can effectively reduce the time necessary for the positioning in the high precision. [0010] Also, another object of the present invention is to provide a positioning apparatus and a positioning method that can reduce the wait time experienced by a user when the user requests the position information in the high precision. [0011] The positioning apparatus according to the present invention includes: a first positioning unit for obtaining a first position information which represents a position of the positioning apparatus itself measured by carrying out a first positioning in a low precision; a displaying unit configured to display the first position information; and a second positioning unit configured to obtain a second position information which represents the position of the positioning apparatus itself measured by carrying out a second positioning in a precision higher than the low precision in parallel with the first positioning and the display of the first position information by the displaying unit. The displaying unit updates a screen based on the second position information. [0012] The positioning apparatus of the present invention firstly measures the low precision first position information in a short time and displays it immediately, so that the waiting time until the earliest position display is short. Simultaneously to the measurement and display of the first position information, the measurement of the second position information which is more precise is executed, resulting that the sensory waiting time is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS [0013] FIG. 1 is a view showing a configuration of a first embodiment in a positioning apparatus of the present invention; [0014] FIG. 2 is a view showing a configuration of a controller 10 in the positioning apparatus of the present invention; [0015] FIG. 3 is a flowchart showing the first embodiment in a positioning method of the present invention; [0016] FIG. 4 is a schematic view explaining an obtained range of map information; [0017] FIG. 5 is a flowchart showing a second embodiment in the positioning method of the present invention; [0018] FIG. 6 is a flowchart showing a third embodiment in the positioning method of the present invention; [0019] FIG. 7 is a schematic view explaining a retrieval range of an information with regard to a food store; and [0020] FIG. 8 is a block diagram showing this position detecting terminal T. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0021] The preferred embodiments of a positioning apparatus and a positioning method of the present invention will be described below with reference to the attached drawings. In the embodiments, a mobile telephone is adopted as an example of the positioning apparatus. Namely, the positioning apparatus 1 is a mobile telephone. However, the present invention is not limited to the example and can be similarly applied to a different portable information terminal (for example, PDA (Personal Digital Assistant), a smart phone, a GPS dedicated terminal). First Embodiment [0022] The first embodiment of the positioning apparatus and positioning method in the present invention will be described below with reference to the attached drawings. At first, the configuration of the first embodiment of the positioning apparatus in the present invention is explained. FIG. 1 is a view showing the configuration of the first embodiment of the positioning apparatus in the present invention. A positioning apparatus 1 includes an interface unit 2 , a positioning communicating unit 3 and a controller 10 . [0023] The interface unit 2 is the user interface of the positioning apparatus 1 and has an input unit 5 and a display 6 . The input unit 5 is the unit through which a user can input the indication to the positioning apparatus 1 and is exemplified by a plurality of keys, touch panels or buttons. The display 6 displays the information on a screen with regard to the information processing operation such as the result by the positioning of the positioning apparatus 1 and the input of the user, and is exemplified by a liquid crystal display. [0024] The positioning communicating unit 3 carries out the positioning for measuring the position of itself and the information communication with the outside and includes a communicating unit 9 , a storing unit 4 , a low precision high speed positioning unit 7 and a high precision low speed positioning unit 8 . [0025] The communicating unit 9 is responsible for the communication between the outside and the positioning apparatus 1 through a network or public telephone line (hereafter, merely referred to as [Network 52 ]). Here, the communication unit 9 is able to communicate with a server 53 that delivers a map information, through a base station 51 (for example: a base station in the mobile telephone, a base station in a radio LAN) and the network 52 . [0026] The storing unit 4 stores the map information including information which represents a map and the information related to the map, and the information (including the map information) received from the server 53 in the communication through the communicating unit 9 . The storing unit 4 is realized by using, for example, the RAM or ROM. The map information is exemplified as the position information (the latitude, the longitude) with regard to the range of the map, the position information (the latitude, the longitude) with regard to the shop such as a food store and the public facility such as a city office, and the information with regard to the shop and public facility themselves. [0027] The low precision high speed positioning unit 7 is the positioning unit for carrying out the positioning whose precision is low and speed is high, and is exemplified by the positioning apparatus which executes the positioning by using a radio base station. For example, in the case that the positioning apparatus 1 is a mobile telephone, the approximate position information (the position information of the low precision) can be obtained from the position of the base station 51 with which the mobile telephone carries out the communication. [0028] The high precision low speed positioning unit 8 is the positioning apparatus for carrying out the positioning whose precision is high and speed is low, and is exemplified by a GPS positioning apparatus using a GPS (Global Positioning System) positioning method. After receiving a starting instruction, the high precision low speed positioning unit 8 can autonomously carry out the positioning and output the result, namely, the information of the position of itself. Thus, the positioning operation carried out by the high precision low speed positioning unit 8 has no influence on the operation speed of the other structure components (the input unit 5 , the display 6 , the low precision high speed positioning unit 7 , the communicating unit 9 , the controller 10 or the like). [0029] The low precision high speed positioning unit 7 and the high precision low speed positioning unit 8 are not required to be the units different from each other. They may be realized by a same apparatus which outputs the positioning result of the high precision low speed after outputting the positioning result of the low precision high speed sequentially. For example, the positioning apparatus having the GPS positioning function repeatedly executes the reception of an electric wave from GPS satellites and the calculation based on the received data, and finishes the positioning when the result which satisfy a predetermined precision is obtained. In the course of this positioning process, the positioning result of the low precision is calculated in the middle of the process. By setting the positioning result of this low precision being outputted, one positioning apparatus (the GPS positioning apparatus) can be used as the low precision high speed positioning unit 7 and the high precision low speed positioning unit 8 at the same time. [0030] The controller 10 controls the operations of the interface unit 2 and the positioning communicating unit 3 . The controller 10 is exemplified by MPU (Micro Processing Unit). [0031] FIG. 2 is a view showing the configuration of the controller 10 in the positioning apparatus of the present invention. The controller 10 stores computer-readable programs including a menu unit 11 , a data collecting unit 12 , a low precision high speed positioning executing unit 13 , a high precision low speed positioning executing unit 14 and a data generating unit 15 . These programs are stored in, for example, the storing unit 4 . Then, they are executed by the controller 10 when the positioning method carried out by the positioning apparatus is executed. [0032] The menu unit 11 displays (exhibits) a plurality of commands (instructions), which can be selected by a user, on the display 6 . The data collecting unit 12 collects the data required to display: the positioning results, which are obtained by the low precision high speed positioning executing unit 13 and the high precision low speed positioning executing unit 14 ; and the information required for the output on the screen of the display 6 . The low precision high speed positioning executing unit 13 instructs the low precision high speed positioning unit 7 to execute the positioning and stores the positioning result in the storing unit 4 . The high precision low speed positioning executing unit 14 instructs the high precision low speed positioning unit 8 to execute the positioning and stores the positioning result in the storing unit 4 . The data generating unit 15 synthesizes the positioning results, the map information and the other information and displays the synthesized information on the display 6 . [0033] FIG. 3 is a flowchart showing the first embodiment in the positioning method of the present invention. Referring to FIG. 3 , the case that the user tries to display a current position on the map is explained. (1) Step S 01 [0034] The user calls up the menu by operating the input unit 5 of the positioning apparatus 1 . The menu unit 11 displays a predetermined menu on the display 6 . The user selects from the displayed menu the item which represents the instruction to display the current position on the map (hereafter, this instruction is referred to as [Current Position Displaying Instruction]). Step S 02 [0035] The low precision high speed positioning executing unit 13 displays the information which shows that the positioning is being executed on the display 6 , in response to the current position displaying instruction. (3) Step S 03 [0036] The low precision high speed positioning executing unit 13 and the high precision low speed positioning executing unit 14 collect the information required to execute the positioning from the information processor, such as the server 53 , through the network 52 through the communicating unit 9 . (4) Step S 04 [0037] The low precision high speed positioning executing unit 13 instructs the low precision high speed positioning unit 7 to execute the positioning. The low precision high speed positioning unit 7 executes the low precision high speed positioning. (5) Step S 05 [0038] The low precision high speed positioning unit 7 finishes the low precision high speed positioning in a short time and obtains the low precision current position information showing the current position of the positioning apparatus 1 , which means the current position of the user. The low precision high speed positioning unit 7 outputs the low precision current position information to the low precision high speed positioning executing unit 13 . The low precision high speed positioning executing unit 13 stores the low precision current position information in the storing unit 4 with the time information representing the time when the positioning is executed. (6) Step S 06 [0039] The data generating unit 15 prepares for the map information corresponding to the low precision current position information. The map information is stored in the storing unit 4 . When the storing unit 4 does not have the corresponding proper map information, the data collecting unit 12 uses the communicating unit 9 , collects the map information from the information processor which is a node external to the positioning apparatus 1 , such as the server 53 , through the network 52 , and stores in the storing unit 4 . The range of the map included in this map information is set to be wider than the displaying range on the display 6 . This is because, since the low precision current position information is great in positioning error, as the result of the high precision low speed positioning, there is a possibility that the current position is to be shifted. The detail thereof will be described later. (7) Step S 07 [0040] The data generating unit 15 adds the low precision current position information to the map information and generates the displaying data so as to be within the displaying range on the display 6 . The data generating unit 15 displays the displaying data on the display 6 . Consequently, the user can view the map where the current position is centered, in the short wait time although the precision is low. (8) Step S 08 [0041] The high precision low speed positioning executing unit 14 instructs the high precision low speed positioning unit 8 to execute the positioning, at the time approximately equal to that of the step S 04 . The high precision low speed positioning unit 8 executes the high precision low speed positioning. Thus, the positioning apparatus 1 can carry out the high precision low speed positioning and result output (S 08 to S 09 ) simultaneously with and in parallel with the low precision high speed positioning and result output (S 04 to S 05 ), the preparation for the map information (S 06 ) and the generation and displaying of the displaying data (S 07 ). (9) Step S 09 [0042] The high precision low speed positioning unit 8 finishes the high precision low speed positioning in the longer time than that of the low precision high speed positioning unit 7 and obtains the high precision current position information indicating the current position of the positioning apparatus 1 as the current position of the user. The high precision current position information is the position information whose precision is higher than that of the low precision current position information. The high precision low speed positioning unit 8 outputs the high precision position information to the high precision low speed positioning executing unit 14 . The high precision low speed positioning executing unit 14 stores the high precision position information in the storing unit 4 with the time when the positioning is executed. (10) Step S 10 [0043] The data generating unit 15 obtains the map information prepared at the step S 06 from the storing unit 4 . The data generating unit 15 adds the high precision current position information to the map information and re-generates the displaying data so as to be within the displaying range on the display 6 . Then, the displaying data is used to update the displaying data on the screen of the display 6 . Thus, the user can view the map where the current position of the higher precision is centered. [0044] At the step S 06 , when the map information is collected from the information processor such as the server 53 , the required degree of the range of the map is determined by the positioning precision of the low precision high speed positioning unit 7 . FIG. 4 is a schematic view explaining the range of the obtained map information. The positioning result of the low precision high speed positioning is not correct so that the center of the obtained range is deviated from the correct real current position 20 , because of the possible positioning error. The deviation is included inside a circle of a positioning precision range 21 at a certain probability. Here a radius of the circle of the positioning precision range 21 corresponds to the maximum positioning error. Let us suppose that a displaying range 22 of the display 6 is square, a preparation range 24 of the map is also square, and the current position is displayed on the center of the displaying range 22 of the display 6 . In this case, as shown on the drawing, when the displaying range 22 is moved such that the centers of the displaying range 22 ( 22 a , 22 b , 22 c and 22 d ) pass on the circumference of the positioning precision range 21 , the preparation range 24 of the map may be set such that the outermost track among the tracks drawn by the displaying range 22 is included. [0045] The preparation range 24 for the map is set as mentioned above. Thus, even if the displaying data on the display 6 is updated in response to the result of the high precision low speed positioning being executed, the map information to be used is located within the preparation range 24 . Thus, when the high precision current position information is displayed, the map information is not required to be obtained again. [0046] The preparation range 24 for the map is wider than the displaying range 22 . Thus, this needs a slightly longer time than that of the obtainment of the map information in one displaying range 22 . However, that time is concealed in the time of the high precision low speed positioning, and the re-obtainment of the map is not required. Thus, until the high precision current position information is displayed, the processing is completed in a short time. [0047] When the communicating unit 9 is obtains the map information, a certain time is required for the communication. Thus, the concealing of the time of the low precision high speed positioning in that time is highly effective. [0048] In this embodiment, the positioning and the preparation of the map are the steps which require a certain time length. By using the positioning method of the high precision low speed, it is possible to start the preparation for the map in a short time. By continuing the positioning of the high precision meanwhile and parallel, it is possible to conceal the time required to make the positioning precision higher in the time required to prepare for the map. As a result, it is possible to reduce the waiting time from the viewpoint of the user. Also, the map to be prepared is the map of the wide range corresponding to the positioning precision of the low precision high speed positioning unit 7 . Thus, even if the map is displayed from the result when the positioning is carried out by the high precision low speed positioning unit 8 , the map which is already obtained can be used. [0049] The user can check the current position information on the map which is roughly correct in the short time. Thus, the frustration of the user caused by the waiting time can be reduced. In addition, it is possible to view the map where the current position of the higher precision is centered, at the slight delay from the current position information of the low precision. Hence, it is possible to reduce the waiting time, which is experienced by the user when the user obtains the position information of the high precision. Consequently, it is possible to effectively reduce the time necessary for the positioning of the high precision. Second Embodiment [0050] The second embodiment of the positioning apparatus and positioning method of the present invention will be described below with reference to the attached drawings. FIG. 1 is a view showing the configuration of the second embodiment of the positioning apparatus of the present invention. This embodiment differs from the first embodiment in that the high precision low speed positioning unit 8 is an AGPS positioning apparatus which uses an Assisted GPS positioning method (hereafter, referred to as [AGPS positioning method]). In this case, the high precision low speed positioning unit 8 uses the low precision current position information of the low precision high speed positioning unit 7 and carries out the GPS positioning. The other configurations are similar to those of the first embodiment, including the configuration shown in FIG. 2 . [0051] FIG. 5 is a flowchart showing the second embodiment of the positioning method of the present invention. In this embodiment, the case that a user tries to display the current position on the map is explained. The operations of each of the steps S 21 to S 27 is similar to the operations of each of the steps S 01 to S 07 in the first embodiment, respectively. The range of the map information at the step S 26 is also similar to the case of the step S 06 , including the correction processing explained above with reference to FIG. 4 . (8) Step S 28 [0052] The high precision low speed positioning executing unit 14 obtains the low precision current position information obtained at the step S 25 from the low precision high speed positioning unit 7 or the storing unit 4 . The high precision low speed positioning executing unit 14 outputs the low precision current position information to the high precision low speed positioning unit 8 and instructs it to execute the AGPS positioning method. The high precision low speed positioning unit 8 executes the high precision low speed positioning using the AGPS positioning method. Thus, the positioning apparatus 1 can execute the high precision low speed positioning and result output (S 28 to S 29 ) simultaneously with and in parallel with the preparation for the map information (S 26 ) and the generation and displaying of the displaying data (S 27 ). The operation of each of the steps S 29 to S 30 is similar to the operation of each of the steps S 09 to S 10 in the first embodiment, respectively. [0053] In the second embodiment, in a course of the operation for obtaining the high precision current position information, the low precision high speed positioning executing unit 13 is obtained. Also in this case, the effect similar to the first embodiment can be obtained. Third Embodiment [0054] The third embodiment of the positioning apparatus and positioning method of the present invention will be described below with reference to the attached drawings. The configuration of the third embodiment of the positioning apparatus of the present invention is similar to that of the first embodiment shown in FIGS. 1 , 2 . [0055] This embodiment differs from the first embodiment in that the high precision low speed positioning is executed in parallel while the information with regard to the vicinity of the current position of the user is obtained and displayed, in addition to the obtainment and displaying of the current position through the low precision high speed positioning. [0056] FIG. 6 is a flowchart showing the third embodiment of the positioning method of the present invention. Here, a case is exemplified in which as the information with regard to the vicinity of the current position, the user tries to display, for example, a position of a food store around the current position. (1) Step S 41 [0057] The user calls up a menu through the input unit 5 of the positioning apparatus 1 . The menu unit 11 displays a predetermined menu on the display 6 . The user selects from the displayed menu the item which represents the instruction to display the position of food stores in the vicinity of the current position on the map (hereafter, referred to as [Target Retrieving Instruction]). (2) Step S 42 [0058] The low precision high speed positioning executing unit 13 displays the information which shows that the positioning is being executed, on the display 6 , in response to the target retrieving instruction. (3) Step S 43 [0059] The low precision high speed positioning executing unit 13 and the high precision low speed positioning executing unit 14 collect the information required to execute the positioning from the information processor, such as the server 53 , through the network 52 through the communicating unit 9 . (4) Step S 44 [0060] The low precision high speed positioning executing unit 13 instructs the low precision high speed positioning unit 7 to execute the positioning of the current position. The low precision high speed positioning unit 7 executes the low precision high speed positioning. (5) Step S 45 [0061] The low precision high speed positioning unit 7 finishes the low precision high speed positioning in a short time and obtains the low precision current position information showing the current position of the positioning apparatus 1 , which means the current position of the user. The low precision high speed positioning unit 7 outputs the low precision current position information to the low precision high speed positioning executing unit 13 . The low precision high speed positioning executing unit 13 stores the low precision current position information in the storing unit 4 with the time when the positioning is executed. (6) Step S 46 [0062] The data generating unit 15 prepares for the map information corresponding to the low precision current position information. The map information is stored in the storing unit 4 . When the storing unit 4 does not have the corresponding proper map information, the data collecting unit 12 uses the communicating unit 9 , collects the map information from the information processor, such as the server 53 , through the network 52 , and stores in the storing unit 4 . The range of the map included in this map information is similar to that of the step S 06 (including the correction processing explained above with reference to FIG. 4 ) in the first embodiment. (7) Step S 47 [0063] The data collecting unit 12 prepares the information with regard to the food store in the map information corresponding to the low precision current position information. That is, the information with regard to the food store is retrieved from the map information stored in the storing unit 4 . Such information with regard to the food store is exemplified, for example, on a table where the position information indicating a store name and a store position is related to the content of the store. When the storing unit 4 does not have the proper information with regard to the food store, the data collecting unit 12 uses the communicating unit 9 and retrieves the information with regard to the food store from the information processor, such as the server 53 , through the network 52 and stores in the storing unit 4 . The retrieval range of the information with regard to this food store is defined to be wider than the range specified by the user (for example, within a radius 100 m from the current position). This is because, since the positioning deviation of the low precision current position information is large, the specification of the user (the displaying range on the display 6 ) may be shifted, as the result of the high precision low speed positioning. The detail thereof will be described later. If the information with regard to the food store can be obtained from the server 53 when the map information is obtained at the step S 46 , the step S 47 may be omitted. (8) Step S 48 [0064] The data generating unit 15 adds the low precision current position information, the store name of the food store and the position information on the map information and generates the displaying data so as to be within the displaying range on the display 6 . Then, the displaying data is displayed on the display 6 . Thus, the user can view on the map the information with regard to the current position and the vicinal (nearby) food store in the short waiting time although the precision is low. (9) Step S 49 [0065] On the other hand, the high precision low speed positioning executing unit 14 instructs the high precision low speed positioning unit 8 to execute the positioning, approximately simultaneous with the step S 44 . The high precision low speed positioning unit 8 executes the high precision low speed positioning. Thus, the positioning apparatus 1 can execute the high precision low speed positioning and result output (S 49 to S 50 ) simultaneously with and in parallel with the low precision high speed positioning and result output (S 44 to S 45 ), the preparation for the map information (S 46 ), the reception, retrieval and result output of the target retrieving instruction (S 47 ), and the generation and displaying of the displaying data (S 48 ). (10) Step S 50 [0066] The high precision low speed positioning unit 8 finishes the high precision low speed positioning in the longer time than that of the low precision high speed positioning unit 7 and obtains the high precision current position information showing the current position of the positioning apparatus 1 , which means the current position of the user. The high precision current position information is the position information whose precision is higher than that of the low precision current position information. The high precision low speed positioning unit 8 outputs the high precision position information to the high precision low speed positioning executing unit 14 . The high precision low speed positioning executing unit 14 stores the high precision position information in the storing unit 4 with the time when the positioning is executed. (11) Step S 51 [0067] The data generating unit 15 obtains the map information prepared at the steps S 46 , S 47 from the storing unit 4 . The data generating unit 15 adds the high precision current position information to the map information and re-generates the displaying data so as to be within the displaying range on the display 6 . Then, the displaying data is used to update the displaying data on the screen of the display 6 . Thus, the user can view on the map the information with regard to the current position and nearby food store, in which the precision is higher. [0068] At the step S 47 , when the information with regard to the food store is retrieved from the information processor such as the server 53 , the required degree of the range of the map is determined in response to the positioning precision of the low precision high speed positioning unit 7 . FIG. 7 is a schematic view explaining the retrieval range of the information with regard to the food store. The positioning result of the low precision high speed positioning is not correct so that the center of the obtained range is deviated from the correct real center position 20 . The deviation is included inside a circle of a positioning precision range 25 at a certain probability. Here, a radius of the circle of the positioning precision range 25 corresponds to the maximum positioning error. Let us suppose that a specified range 26 of the user is circular, a retrieval range 28 is also circular, and the current position is displayed on the center of the displaying range on the display 6 . In this case, as shown on the drawing, when the specified range 26 is moved such that the centers of the specified range 26 ( 26 a , 26 b , 26 c and 26 d ) pass on the circumference of the positioning precision range 25 , the retrieval range 28 may be set such that the outermost track among the tracks drawn by the specified range 26 is included. [0069] The retrieval range 28 is set as mentioned above. Thus, even if the displaying data on the display 6 is updated in response to the result of the high precision low speed positioning being executed, the information with regard to the food store to be used is located within the retrieval range 28 . Thus, when the high precision current position information is displayed, the map information (the information with regard to the food store) is not required to be obtained again. [0070] The third embodiment has been explained by exemplifying the operation for displaying the position of the food store around the current position on the map. However, the present invention is not restricted to this example. For example, the information of the vicinity of the current position can be similarly used even when another information service which is suitable for displaying on the map is executed. As such information of the vicinity of the current position, the information of various facilities such as a restaurant, a department store, a shop, a culture facility and a public facility, the information with regard to the action contents in the various facilities and the like are exemplified. [0071] The user can check the current position of him- or herself and the information with regard to the food store on the map which is roughly correct in the short time. Thus, the frustration of the user caused by the waiting time can be reduced. In addition, it is possible to view the map where the current position of the higher precision is centered, at the slight delay from the current position information of the low precision. Hence, it is possible to reduce the waiting time, which is experienced by the user when the user obtains the position information of the high precision. Consequently, it is possible to effectively reduce the time necessary for the positioning of the high precision. [0072] In the third embodiment, the process requiring relatively long time is the positioning, the preparation for the map, the instruction from the user and the information retrieval. The use of the positioning method of the high precision low speed enables the preparation for the map and the shift to the state at which the instruction is received from the user, in the short time. The positioning of the high precision is continued in parallel to the execution of the instruction of the user. Thus, the time to enhance the positioning accuracy can be concealed in the time to receive the instruction from the user. As a result, it is possible to reduce the waiting time from the user. Also, the prepared retrieval result is the result retrieved from the wide range corresponding to the positioning precision of the low precision high speed positioning unit 7 . Hence, the pre-obtained retrieval result can be used even if the retrieval result is displayed from the result after the positioning is carried out by the high precision low speed positioning unit 8 . [0073] It is possible to provide the user with the positioning result, such as the map or the like, although the precision is low, without waiting long time. While the user reads the result or carries out the instruction from the result, the apparatus can obtain the positioning result of the high precision and update (compensate) the displaying. The user can obtain the result of the high precision without waiting for a long time as the result.

A positioning method includes performing a first positioning by carrying out information communication with an external part of an positioning apparatus to obtain a first information indicating a position of an object to which the method is applied, displaying a first map representing the position of the object indicated by the first information, performing a second positioning by carrying out information communication with an external part of the positioning apparatus before displaying the first map to obtain a second information indicating the position of the object more precisely than the first information, and displaying a second map representing the position of the positioning apparatus indicated by the second information without responding to another instruction from the user of the positioning after the displaying the first map.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of, and claims priority to, co-pending U.S. application Ser. No. 13/754,443, filed Jan. 30, 2013, which claims priority to U.S. application Ser. No. 11/965,456, filed Dec. 27, 2007, now issued as U.S. Pat. No. 8,386,629, which are incorporated herein by reference in their entirety. FIELD [0002] The disclosed embodiments generally relates to the field of data transmission systems for digital communications and more particularly to the optimization and/or management of the distribution of non-live content using Internet Protocol (IP) multicast data transmissions combined with unicast and/or other parallel transmission means over a network. BACKGROUND [0003] Traditional internet distribution of non-live content generally employs a unicast delivery system. Also, when unicast is used, it is generally the exclusive method of transmitting content. Unicast communications send one copy of each data packet to each intended recipient. However, unicast presents scaling problems, when the group of recipients is large. In unicast, the network must carry one copy of the same content data for each destination client, thus requiring additional bandwidth for data transmission. Thus, the server and network resources required are directly proportional to the number of receiving clients. [0004] Non-live content, as referred to herein, is generally a download defined by a fixed length text, video, audio and/or data file. The entire content is preferably recorded and/or defined prior to initiating delivery. Examples of such content files include one or more software applications, movies, videos, music, news, periodicals, journals, magazines or electronic documents. Thus, non-live content can include non-time critical downloads, such as a new software release. The start time, end time or download speed for delivery of such non-time critical content is not necessarily significant to the end user. Also, non-live content can include more time critical downloads, such as a popular new movie release, which must be displayed to the end user in near real-time shortly after the download is initiated. However, both of these examples are distinguished from live content, whose entirety is not well defined at the start of delivery. A defining characteristic of non-live content delivery is the lack of synchronicity, in terms of both time and download bandwidth, amongst receiving clients. [0005] IP multicasting (also referred to as simply “multicasting” or “multicast”) provides a useful way for a source to transmit a stream of content data to a group of recipients. Multicasting transmits only one copy of the data packets from the content source server and allows multicast enabled routers to do the work required to optimally replicate and deliver that packet to each intended recipient. Like unicast, when multicast is used, it is generally the exclusive method of transmitting content. Multicast uses the concept of a group to route its data. A group of receivers subscribe to a particular multicast transmission. The individual receivers of the group need not physically or geographically be located near one another. Similarly, the data can be transmitted to the group from one or more sources located virtually anywhere, as long as they can communicate with the receivers through a common network of computers, such as the Internet. [0006] Rather than transmitting multiple copies of data packets, with one copy going to each receiver's IP address as in unicast, multicast transmits one copy of its data packets to a designated multicast group address. Each source in a multicast session transmits data which is assigned to that source's IP address and the designated multicast group's IP address. This address pair is generally represented by the notation (S, G), where S is a source IP address and G is the group IP address. [0007] Traditionally, no two sources would transmit to the same multicast group having the same (S, G) IP address pairing. However, for reliability, two or more sources can be assigned an identical IP address S transmitting the same content to the same group address G. This type of source addressing is referred to as an Anycast source address. With an Anycast source address each multicast-enabled router in the network can select and join the multicast tree of the nearest available source, which will result in two (or more) disjoint multicast trees when multiple Anycast the sources are in operation. When one of the Anycast sources fails, an automatic rerouting mechanism of the multicast-enabled routers previously on the tree of the failed source will select and join the tree of the nearest remaining source(s). Further information on multicasting is provided in U.S. Pat. No. 6,501,763, which is incorporated herein by reference. [0008] While multicast is very resource efficient, it is historically considered unsuited for delivery of non-live or non-simultaneous content due to the lack of synchronicity amongst the receiving clients and that a uniform delivery stream bandwidth (BW) cannot be assured. Delivering non-live content through multicast is further disfavored due to problems associated with data loss. Data loss has a potentially more significant impact in multicast than in unicast transmissions. The distribution of routers in a multicast session generally has a tree-like configuration with numerous branches. Thus, this multicast configuration means that when packets are lost in transit, all recipients on downstream branches from that point lose the same packet(s). Such data loss has various sources, such as congestion or irrecoverable errors in the network. [0009] In order to improve network and server resource efficiencies when using unicast, methods such as local network server caching and peer-to-peer (P2P) redistribution techniques have been used. Local caching uses multiple local servers to receive a content stream from the origin servers and deliver the content to individual receivers closest to them. While reducing the distribution burden to some network resources, local caching does not reduce the burden on content servers and their network-access links. While current P2P delivery can reduce the burden on the CP's content servers and access links, it is not network-optimized; it can actually worsen the burden on the long haul network by substituting long-haul network efficient delivery by local cache servers with inefficient delivery by distant P2P sources. P2P takes advantage of the computing power of individual user computers. Any user participating in a P2P-based delivery acts as a content host by downloading the content from the Content Provider (CP) server(s). In this way, each participating P2P host becomes a server for other receivers that are in the process of downloading or will in the future download the content. However, while being more server efficient, P2P burdens tend to increase network transmission distance and therefore network resource usage, thus further reducing network efficiency. Also, in the case where P2P hosts are connected via the internet, since many individual internet users have very limited upstream bandwidth, P2P becomes less viable as CP's start increasing BW requirements for particular content streams. [0010] Additionally, during the course of content delivery, there is generally a great deal of uncertainty and unpredictability regarding the level of demand for any particular content. High/low demand periods can fluctuate and the popularity of particular content can increase and decrease dramatically. This makes capacity planning difficult for a CP who generally pre-plans their network-access and server capacities, in order to ensure an adequate supply of servers and network access link resources devoted to each content stream. Once a distribution plan for content is decided, a CP does not typically change it during a delivery period, even though content demand in that period may be very different from what was predicted. SUMMARY [0011] One embodiment relates to a method of distributing a non-live content stream in a network. The method comprises transmitting an initial meta-file in response to receiving a request for a non-live content stream. The initial meta-file comprises information, and the information identifies a division of the content stream. The information also identifies a multicast source server and a unicast source server. The method also comprises transmitting at least a first portion of the non-live content stream using the multicast source server and at least a second portion of the non-live content stream using the unicast source server. [0012] Another embodiment relates to a computer-readable medium comprising instructions, wherein execution of the instructions by at least one computing device distributes a non-live content stream in a network. The non-live content stream is thereby distributed by transmitting an initial meta-file in response to receiving a request for a non-live content stream. Also, the initial meta-file comprises information, and the information identifies a division of the content stream, a multicast source server and a unicast source server. The non-live content stream is further distributed by transmitting at least a first portion of the non-live content stream using the multicast source server and at least a second portion of the non-live content stream using the unicast source server. [0013] Yet another embodiment relates to a system for distributing a non-live content stream in a network. The system comprises a multicast source server adapted to transmit at least a first portion of the non-live content stream in response to transmission of an initial meta-file. The initial meta-file is transmitted in response to receiving a request for a non-live content stream. Also, the initial meta-file comprises information, where the information identifies a division of the content stream and a unicast source server adapted to transmit at least a second portion of the non-live content stream. Further, the initial meta-file identifies the multicast source server and the unicast source server. [0014] Yet a further embodiment relates to a method of distributing a non-live content stream in a network, where the method includes dividing the non-live content stream into a plurality of blocks. The method also includes generating an initial meta-file associated with the blocks, where the meta-file for each of the blocks includes information associated with at least two content stream sources. Also, the sources include a multicast server and a non-multicast server. Further, the method includes transmitting the plurality of blocks and the meta-file data in the network. [0015] Additionally, the information above can represent the division of the content stream into a plurality of blocks, where the first and second portions comprise distinct blocks. The meta-file can comprise data identifying at least one of a plurality of blocks, a sequence number associated with each of the plurality of blocks, a size of the plurality of blocks, a checksum of the plurality of blocks and at least one source address. Further, the method, system and/or execution of instructions from the computer readable medium described above can further receive information representing a quantity of destinations to which the content stream is transmitted. Also, the method, system and/or execution of instructions from the computer readable medium described above can transmit a subsequent meta-file. The subsequent meta-file can comprise information identifying a source server different from at least one of the multicast source server and the unicast source server. Also, the subsequent meta-file can be transmitted subsequent to transmission of at least one of the first and second portions of non-live content stream. [0016] The disclosed embodiments also relate to a method of distributing a non-live content stream in a network, which includes transmitting an initial meta-file in response to receiving a request for a non-live content stream, the initial meta-file identifying a division of the content stream into a plurality of blocks, and a plurality of available sources for delivery of the plurality of blocks. The plurality of available sources include a first multicast source server and a second multicast source server, the initial meta-file assigning a first portion of the plurality of blocks for delivery using the first multicast source server, and assigning a second portion of the plurality of blocks for delivery using the second multicast source server. The method further includes transmitting the first portion of the plurality of blocks using the first multicast source server, and transmitting the second portion of the plurality of blocks using the second multicast source server. The first and second portions correspond to distinct non-overlapping portions of the non-live content stream. [0017] The disclosed embodiments also relate to a non-transitory computer-readable storage medium storing computer-readable instructions that, when executed by a computing device, causes the computing device to distribute a non-live content stream in a network by transmitting an initial meta-file in response to receiving a request for a non-live content stream. The initial meta-file identifies a division of the non-live content stream into a plurality of blocks, and a plurality of available sources for delivery of the plurality of blocks. The plurality of available sources include a first multicast source server and a second multicast source server, the initial meta-file assigning a first portion of the plurality of blocks for delivery using the first multicast source server, and assigning a second portion of the plurality of blocks for delivery using the second multicast source server. The instructions further cause the computing device to transmit the first portion of the plurality of blocks using the first multicast source server, and the second portion of the plurality of blocks using the second multicast source server. The first and second portions correspond to distinct non-overlapping portions of the non-live content stream. [0018] The disclosed embodiments additionally relate to an apparatus for distributing a non-live content stream in a network, which includes a meta-file server device, a first multicast server device and a second multicast server device. The meta-file server device transmits an initial meta-file, the initial meta-file being transmitted in response to receiving a request for a non-live content stream, the initial meta-file identifying a division of the non-live content stream into a plurality of blocks, and a plurality of available sources for delivery of the plurality of blocks. The available sources include the first multicast source server device and the second multicast source server device. The first multicast source server device transmits a first portion of the plurality of blocks in response to transmission of the initial meta-file, the initial meta-file assigning the first portion of the plurality of blocks for delivery using the first multicast source server device. The second multicast source server device transmits a second portion of the plurality of blocks, the initial meta-file assigning the second portion of the plurality of blocks for delivery using the second multicast source server device. The first and second portions correspond to distinct non-overlapping portions of the non-live content stream. [0019] Other aspects of the disclosed embodiments will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the disclosed embodiments. BRIEF DESCRIPTION OF THE DRAWINGS [0020] FIG. 1 is a schematic representation of a network configuration for content delivery. [0021] FIG. 2 is a flow chart showing a method for delivering high-demand non-live content in accordance with one embodiment. [0022] FIG. 3 illustrates distribution of data corresponding to content delivery in accordance with one embodiment. [0023] FIG. 4 illustrates distribution of data corresponding to content delivery in accordance with another embodiment. [0024] FIG. 5 illustrates distribution of data corresponding to content delivery in accordance with yet another embodiment. DETAILED DESCRIPTION [0025] The disclosed embodiments relate to a method and system that enables online distribution of a non-live content stream using IP multicast. The embodiments preferably use multicast to deliver the bulk of the content, while using an additional content delivery method for any portions needed to complete the content delivery. The additional content delivery method(s) can include unicast, anycast, local caching and/or network-optimized peer-to-peer networking. The embodiments also include a method whereby the lack of synchronicity from traditional multicast is overcome by using hybrid delivery methodologies, allowing non-live content delivery to benefit from the efficiencies in network, content server and access link resources derived from multicast delivery. This method and system can deliver content to clients requiring varied download bandwidths, and start and completion times by using parallel servers preferably using more than one delivery technique. [0026] The method and system of the disclosed embodiments are preferably suited for on-line delivery of large-size, high demand non-live content. The embodiments can reduce costs, increase efficiency in a network, including a CP's servers and local access link resources. Additionally, the method and system presented herein is less limited by local bandwidth restrictions/uniformity or lack of synchronicity. Also, it can reduce capacity planning uncertainty and/or make the accuracy of such planning less critical. [0027] There is, therefore, a need for a method of and system for delivering non-live content that reduces costs, is more efficient for the network, including the CP's servers, local access link resources, and less limited by local bandwidth restrictions or lack of synchronicity. Also, a distribution method and system is needed that reduces capacity planning uncertainty, minimizes the need to do such planning and/or makes the accuracy of such planning less critical. [0028] As shown in FIG. 1 , the CP preferably uses a Web/Meta-File Server 100 to interact with clients 140 requesting content. Preferably, the Web/Meta-File Server 100 acts as a traditional web server, providing information and receiving information from the clients 140 . The term “clients” is intended to mean any entity (individual or group) capable of requesting and receiving the subject content. Thus, a client 140 seeking to obtain a content-object file transmits a Content Request CR, which is in turn received by the Web/Meta-File Server 100 . Thereafter, the Web/Meta-File Server 100 can, if appropriate, transmit a content meta-file m or have one transmitted to the client 140 . The content meta-file m will then provide the client 140 with the necessary information to obtain the content. It should be understood that while the Web/Meta-File Server 100 is shown as a single piece of equipment, it can be a collection of servers working together to perform the necessary tasks. [0029] In one embodiment, a Content Transport Management Server (CTMS) 105 generates the provided meta-file and controls the contents therein (i.e., the information provided to the clients 140 ). The Web Server 100 can communicate with the CTMS 105 as needed. Additionally, the CTMS 105 can analyze content demand and manage the network servers and/or resources delivering the content. Alternatively, those functions and capabilities described for the CTMS 105 can be provided by more than one server or can be incorporated in part or in whole into the Web/Meta-File Server 100 . [0030] In order to ensure content delivery, the CP will preferably have available at least one Origin/Multicast Server 110 , which stores and maintains the non-live content to be delivered and additional related information. The Origin/Multicast Server 110 is responsible for distribution of the entire content-object file. The content-object file is transmitted to clients 140 through the network 120 preferably using a hybrid multicast delivery method. The hybrid multicast delivery method in accordance with the disclosed embodiments preferably uses one or more multicast M, supplemented or enhanced by one or more parallel or concurrent unicast(s) U. [0031] Using the provided meta-file m, the client 140 preferably joins one or more available multicast(s) M as needed to obtain the bulk of the requested content. It should be understood that while only a single multicast M session is illustrated; preferably more than one such session is available to each client 140 . Thus, the client can receive one or more simultaneous content streams using this method. Also, the client 140 may leave any individual source once it is no longer needed. [0032] The Origin/Multicast Server 110 preferably delivers content through each multicast M to one or more Network Edge Equipment (NEE) 130 , which each provides a substantially direct link to one or more clients 140 . FIG. 1 shows inactive clients 140 , indicated by boxes with phantom lines, as well as active clients 140 , indicated by boxes with solid lines. As shown, one or more active and/or inactive clients 140 can be connected to a particular NEE 130 . It should be noted that although this description makes use of DSL broadband access service network environment to illustrate the application of the disclosed embodiments, these embodiments are applicable for any wired or wireless access network-service environment that supports multicast transport (either in native or tunneled mode). The NEE 130 routes data between the clients 140 and the network 120 . Hence, the NEE in this description preferably represents any IP transport network-service (wired or wireless) access equipment that is multicast-capable. However, it should be understood that multicast tunneling or other configurations could be employed; in order to support a particular NEE that is not multicast-capable. [0033] Additionally, the Origin/Multicast Server 110 preferably delivers content or portions thereof through unicast U or multicast M to several designated and preferably local Unicast Servers 160 . While the illustration in FIG. 1 shows the Unicast Server 160 receiving its content stream through unicast, it should be understood that it can receive its content stream through either unicast or multicast. Each Unicast Server 160 is preferably selected by the CP for optimization, and can be located in close proximity to active clients 140 , or a more remote, perhaps central, location. Preferably, the Unicast Server 160 is a local cache server. Alternatively, the Origin/Multicast Server 100 can even act as a designated Unicast Server 160 . A function of the Unicast Server 160 is to maintain an entire single copy of the content file and make any portion thereof available for a client to download on request from clients. It should be understood that although only a single unicast server 160 is illustrated supplying the client 140 with the necessary portion(s) of the unicast U, more than one such unicast servers server can be made available to each client 140 in the form of multiple Unicast servers or Anycast servers, and potentially in combination with using other downloading clients operating in P2P mode as sources. [0034] The Unicast Servers 160 act as a unicast source for the clients 140 and can direct to the clients 140 , through the NEE 130 , any portion of the content that was lost, received in error or otherwise needed. Without access to a Unicast Server 160 , if a client 140 joined a multicast M after the start of a content transmission, they would either have to wait for a replay of the content transmission to catch the beginning or simply miss the beginning. Accordingly, the Unicast Servers 160 can be used to download those missing initial portions. Thus, the Unicast Servers 160 make fast start-up or start-of-play available, without making the client wait for the replay or do without the beginning of the content. Also, immediate access to start-of-play or initial portions allows delivery of time-critical or chronologically arranged content using the hybrid multicast of the disclosed embodiments. [0035] In an alternative embodiment, the CP may intentionally exclude selected, critical portions or blocks of data from the multicast streams, making these blocks available only through the unicast servers. This will render the content received from the multicast streams unusable unless it is supplemented by the excluded blocks. The need for each recipient to obtain these blocks directly from the Unicast Server 160 gives the CP an avenue to control access to the content stream for various purposes, e.g. to control access to subscriber only content, to enforce digital rights, etc. In this way, the Unicast Servers 160 can be designated as the sole sources for selected portions of the content that are only made available via unicast, for content access-control purpose. For example, a CP might select some portions of the content object to be embedded with target user-specific watermarks and/or encrypted with a target user/device specific key and delivered to target user/device via one or more Unicast Servers 160 . Thus, the Unicast Servers 160 can be used to obtain rich service extensibility and flexibility. [0036] While the network 120 is shown as a unified collection of communication devices, presumably controlled or accessible by a single CP, it should be understood that the network 120 and its resources are not necessarily provided or controlled by a single entity. The network 120 can be formed by multiple concatenated networks. Additionally, although this embodiment is discussed in the context of contemporary internet communication, it can apply equally to intranet, private or other networks. [0037] While the CP can plan, configure and reconfigure the appropriate network resources to ensure delivery of the content, it is the end users or clients that individually or as a group request it. Thus as mentioned above, it is the individual clients that initiate a request for a particular non-live content. As shown in the flowchart of FIG. 2 , a request for content is preferably received in 200 by the CP from a client via the network, as described above. [0038] Then in 210 , the CP preferably verifies and/or checks what resources the client has in order to ensure they can successfully receive the desired content. For example, do they require software in order to download and/or run the requested file; are they capable of receiving multicast; or other resource inquiries. As mentioned above, the interaction between the CP and the client can be performed by a web server, meta-file server, CTMS and/or other facility, through a query or interaction with the client. Alternatively, a client's ability to receive multicast can be determined through a multicast-reception test. In this way a client is instructed to fetch information from an always-on multicast channel that continuously transmits a small deterministically varied information object (such as a Universal Time Clock reading). If a particular client cannot successfully report the information object, that client will not be considered multicast capable. [0039] The CP in 220 preferably transmits or directs delivery of a content meta-file to the client. The content meta-file preferably contains information, such as a description about the content-object and a list of available sources for delivery of the content. The meta-file is preferably transmitted/delivered in 220 via unicast prior to and separately from the content. If a client is deemed multicast capable, then preferably the provided meta-file would contain one or more multicast addresses and at least one Unicast Server address. If there is more than one multicast source, the client can choose to join one source at a time or any number of sources simultaneously. The designated source or sources are preferably selected as a function of desired completion time and available download bandwidth. [0040] In one embodiment, the client is sent the same meta-file regardless of whether they are multicast capable or not. In the event they are not multicast capable, they can attempt to join the multicast and resort to using the unicast source after timing-out with the multicast source. Alternatively, if the client is not deemed able to receive multicast up front, then a different meta-file is chosen that contains only one or more unicast servers as the available source(s). Thus, the client would use the meta-file to obtain necessary source information, even though they could not benefit from a hybrid multicast delivery. Alternatively, the client could be provided with a different type of file or other data indicating that the desired content must be obtained through unicast only. As a further alternative, the non-multicast capable client's request could “time-out” after a period of not receiving a response from the CP, indicating they must use unicast. As yet a further alternative, if a client is determined to be non-multicast capable, they can be provided with software to enable multicast capabilities. [0041] Once received, the meta-file is preferably used by the client in 230 to choose or designate desired delivery source(s) or parameters. At this point, or perhaps prior to delivering the meta-file, the CP can provide the client or direct them to obtain any necessary software, such as a downloader file. If a multicast source is listed in the meta-file, the client can begin multicast content delivery in 240 , while also using the unicast content delivery in 245 . Alternatively, if no multicast source is listed or if the client is simply not able to use multicast, then the unicast content delivery in 245 would be exclusively used. [0042] In 240 multicast delivery can be implemented by the client joining one or more available multicast sessions. Preferably, the client can disconnect from any source at any time it is no longer needed or desirable. Additionally, the client preferably uses the unicast content delivery in 245 to obtain missing or otherwise needed content blocks. In this way, the client can obtain a significant portion of the content-object file from the multicast source(s) in 240 and obtain any blocks with errors, missing blocks or otherwise needed blocks from the unicast source in 245 . Additionally, the unicast source in 245 can be used to obtain needed start of file blocks to speed up or catch-up to the segments being delivered by the selected multicast source(s) in 240 . In 250 , the complete content is delivered to the client. [0043] It should be noted that both unicast and multicast sources may additionally use Anycast for network optimality, redundancy and/or load balancing. Anycast is a network addressing and routing method in which multiple servers are assigned the same identical IP address (referred to as an Anycast address) and communication traffic from clients directed at that Anycast address are routed by the network to the nearest available server from source network. Both unicast and multicast delivery may utilize Anycast technology so as to optimize the match between a source server and a recipient of the content in terms of delivery of the content from server to receiver. Anycast can be used in conjunction with multicast transport to provide source redundancy, in conjunction with unicast transport to provide server redundancy and load-sharing. In the case of Anycast with unicast transport, by providing the network with near real-time information on utilization of each unicast server (via the CTMS) the network can apply routing control technique to direct the client communication traffic to the nearest server that is not highly loaded rather than just the nearest server in operation. Such routing techniques are disclosed in as described in U.S. Published Patent Application No. 2006/0206606 to Iloglu et al., which is incorporated herein by reference. [0044] Alternatively, in addition to or in place of the unicast source, network optimized P2P networking can be used to obtain needed blocks from peer computers that already have that portion of the content. One criterion for P2P network optimality is locality. In other words, other clients that have already retrieved or are retrieving the same content-object file and are in the same local network zone as a given client (referred to as localized peers) can act as a source by supplementing or working in place of the Unicast server unicast source. For example, with reference to FIG. 1 , the two active clients 140 in the lower left portion could work as localized peers, with one retrieving needed data from the other. The network provider may choose other criterion for determining which P2P sources are best matches for particular receivers. [0045] FIG. 3 shows one embodiment where the content-object file is transmitted over the network as a content stream 300 for delivery to the client 340 . The entire stream 300 is divided into blocks 310 . The actual size of each block or each sequence of blocks is preferably decided by the CP. Generally, a balance is met between using too many blocks (a small block size), which demands greater overhead, versus too few blocks (a large block size), which translates into wasted resources when a large block contains an error. However, the CP can choose any block size appropriate to the content being delivered and the environment in which it is being delivered. [0046] FIG. 3 shows four multicast sources 320 (individually designated as mS 1, mS2, mS3 and mS4) are delivering non-overlapping ranges or segments of blocks 310 . It should be understood, however, that a single multicast source can be used or alternatively a greater number of multicast sources can be used. However, when multiple parallel sources are used as shown in FIG. 3 , it allows each receiving client to determine its own download rate by choosing to receive from one or more of the sources either simultaneously or sequentially. In FIG. 3 , the first three sources mS1, mS2, mS3 deliver a number of blocks 310 equal to the variable n. In this illustration, the variable “n” equals 4; however the actual number of blocks will depend on the length of the content file. The last source mS4 is shown delivering “n−x” blocks 310 , which represents the remaining blocks 310 needed to complete the content stream 300 . As shown in FIG. 3 , the variable “x” equals 1, however once again the actual number will depend on the content file. Thus, the total number of blocks 310 included in the illustrated content stream 300 is calculated by “4n−x”; where the “4” represents the number of sources 320 ; the “n” represents the number of blocks being delivered by each multicast source mS1, mS2, mS3, except the last mS4; and the “x” represents the difference between the number of blocks in the earlier segments and the number of blocks in the last segment, delivered by multicast source mS4. Preferably, using a hybrid multicast delivery method that employs both multicast and unicast, all the blocks B1 through B(4n−x) contained in the content stream 300 get delivered to each client 340 . [0047] FIG. 3 also shows that the content-object file or content stream 300 is divided into indexed blocks 310 , which can be optionally grouped into segments of contiguous blocks (B1-Bn). Preferably, substantially all the blocks 310 are divided into the same size. However, at least one block in the stream 300 may be smaller, containing any remaining data which does not fill an entire block, unless padding bits are used for the last block to fill it out to the size of the other blocks. [0048] The meta-file generated for the content-object file, preferably contains a content-object descriptor (COD) and a list of sources able to provide or transmit the content. The COD preferably contains the overall content-object file ID, size, checksum, total number of blocks and their individual checksums. Optionally, the file type, access control information and other information that is relevant to either the CP or the client are also included. [0049] The source list in the meta-file preferably identifies each source or group of sources available for downloading the content. The source list preferably includes for each source an address, assigned range of blocks, sequence number for the blocks, the length of the blocks and other control information the CP determined is needed for the download. Preferably the sources include one or more multicast sources and at least one unicast source. The CP can decide how many sources and whether or when a multicast, unicast, anycast or any other particular source is included in the source list, based on the projected and/or current demand for the content. The embodiments described below explain some alternatives for how the file data is distributed and delivered from the various sources. However, it is the source list that indicates to the client what current distribution scheme is available. The client can be supplied with software that includes instructions to periodically check for and download the latest meta-file and switch sources to the latest ones available. This gives the CP more control to dynamically switch currently downloading clients to other sources allowing the CP tremendous flexibility to manage the content delivery sources based on current demand. [0050] The CP can preferably collect real-time or periodic receiver statistics per content stream that can be used to decide when the number of interested receivers exceeds or falls below their threshold. Such statistics can be reported periodically by the clients, the NEE or other network resources. Alternatively, the CP can assume current demand follows the number of Content Requests, ignoring or estimating clients that drop-out of a session. Also, if network optimized P2P delivery is utilized, the above statistics can be used to keep current the list of available network optimized P2P sources for each group of receivers. As a further alternative, the CP can monitor actual demand for a particular content based on information provided by a network provider. [0051] Regardless of how the CP collects and analyzes its statistics, preferably it can dynamically determine how many, and what types of servers (unicast or multicast) are needed to be maintained, dropped or brought online to adequately serve the current demand. These changes can be reflected in the source lists in the content meta-file downloaded to new or currently downloading receivers. The CP can thus react dynamically to the demand for that content. The CP preferably has the ability to change the delivery source selections at any time during a delivery period. This is preferably done by changing the source list information contained in the meta-file. In this way, in response to a significant change in demand for a particular content-object file the CP can change distribution methods mid-stream. The decision to implement hybrid multicast is preferably driven by the actual or likely density of active download clients 140 within a particular timeframe. Also, if a content stream 300 exceeds or drops below a CP's download demand threshold, this too can drive the decision of whether to continue to use, stop using or switch over to hybrid multicast. If it is determined that demand for a particular content is not high enough to use hybrid multicast, the CP can switch over to a different distribution method, such as unicast only. Also, if content is currently being delivered exclusively by unicast and the demand gets high enough, the CP should be able to switch over to hybrid multicast. The higher the number of active clients 140 , the more beneficial hybrid multicast can benefit the CP. Also, other factors such as required download completion time, throughput requirements for the delivery or whether the download content is time critical or not can influence a CP's decision of which delivery technique to use. [0052] A change in network resources supplying content can impact downloading clients. Clients initiating Content Requests after a dynamic meta-file change would simply use the updated source list to obtain the content from the active sources. However, clients already downloading when a source server is dropped, will be forced to switch to another source or rely entirely on the sources (multicast and/or unicast) listed in the original meta-file they received. Alternatively, the client can request an updated meta-file. It is the CP's decision whether such source server drops are appropriate for the delivery of a particular content stream. For some content streams it may be more appropriate to let each server complete serving its current receivers before being brought offline for that stream. [0053] One embodiment demonstrating how to distribute the multicast portion of the delivery is shown in FIG. 3 . In particular, a group of four (4) designated sources 320 are each responsible for continuous, repeated replay of distinct, non-overlapping portions or segments of the content, in conjunction with a unicast source 360 responsible for supplying any needed blocks or portions from a complete copy of the content 300 . Using this distribution method, high bandwidth clients desiring fast download can join two or more of the multicast sources for the bulk of the content file and use the unicast source to obtain needed blocks. This particular distribution method is preferably suited for non-time critical downloads, such as the download of a new software release or other applications that do not need any part of the content for display or use until the entire content is successfully downloaded. The duration of the download is primarily a function of the length of the content and the speed of the user link available to support the download. FIG. 3 shows the client 340 receiving the content from various sources, particularly four multicast sources 320 and a unicast source 360 . However, several downloaded blocks S1B2, S2B3, S4B2 are missing or contain errors E 1 , E 2 , E 3 . The client 340 is then able to obtain the missing or replacement data R 1 , R 2 , R 3 from the unicast source 360 . Thus, each client 340 compiles a complete data-content file based on blocks received from more than one source. [0054] FIG. 4 shows another embodiment demonstrating an alternative method of distributing the multicast portion of the content. The CP establishes a group of multicast sources 420 mS1, mS2, mS3, mS4 that are each responsible for contiguous, repeated replay of the entire content stream 400 out-of-phase with each other. This multicast distribution is done in conjunction with a unicast source 460 responsible for supplying any needed blocks or portions. The client 440 can join one of the multicast source(s) for the bulk of the content file and use the unicast source to obtain missing blocks and/or blocks with errors. For non-time critical downloads almost any available multicast source can be chosen for downloading the bulk of the content. FIG. 4 shows the client 440 joining a multicast mS1 to download most of the blocks 410 , while obtaining a replacement block R 14 from the unicast source 460 . In this example, mS1 was chosen but due to the timing of when the client 440 joined the session, the client first receives block B5, rather than the first block B1. However, with a non-time critical download, the client can wait for multicast mS1 to replay and receive blocks B1-B4 at the end. [0055] The choice or selection of which multicast source to use can be left to client preferences. If the download is not time critical and the content is not needed until it has been downloaded in its entirety, then the selection of which source to use can be random. However, if the client desires to start using (e.g. displaying a movie) the content as soon as possible, before the content has been downloaded in its entirety, then the below embodiment can be implemented. [0056] In the case of multiple overlapping out-of-phase multicast sources, a client can join more than one source for faster download completion (at the expense of more download bandwidth consumption). If it chooses to subscribe to only one source (due to limited download bandwidth) it may “hunt” for the source which is currently transmitting closest to the beginning of the file if the client wishes to minimize content object play-out delay (e.g., in the case of audio or video file). [0057] FIG. 5 shows yet a further embodiment similar to that shown in FIG. 4 . The embodiment in FIG. 5 , as with FIG. 4 , uses four multicast sources 420 , each transmitting the entire content file, but time-shifted from one another. In this embodiment, the client 440 initially joins all of the multicast sources 420 in order to identify the source that is currently delivering content blocks closest to the start of the content file. The client 440 then chose to continue to download from multicast source mS4 and drop the other multicast sources mS1, mS2, mS3. The client simultaneously joined one or more unicast sources 460 to obtain the missing blocks or blocks with errors R 14 , as well as the missing start block B1. Once sufficient missing blocks have been received (particularly any missing start blocks) the client can start playing the content, while continuing to receive the remaining content file from its various sources. Thus, the bulk of the content file is downloaded from the chosen multicast source mS4. The client 440 also uses the unicast source 460 to fill-in any missing blocks. This particular distribution method is preferably suited for downloads that the client desires to play as soon as possible, before the entire content file download has been completed. For example, the download of a popular movie, television show or video, newly available on-line. In such instances, the start of the file must be available almost immediately at the start of the download and there should not be any interruption in playing the file once it starts. [0058] As shown, by using four multicast sources, each multicast source mS1, mS2, mS3, mS4 is time shifted by approximately a quarter of the length of the content file from the others. Thus, on average a client should be able to start a download from a single multicast server, recovering less than a quarter of the content file from an alternate source. It should be understood that a greater or smaller number of sources can be provided, if warranted by content demand. The greater the number of sources, the greater the likelihood that a client can join a source at or near the start of a replay cycle. [0059] Distribution in accordance with the disclosed embodiments can be performed over almost any network. Such networks include wired or wireless traditional or future telecommunications networks, data networks, corporate networks, the Internet, personal or private area networks or other means available to communicate information. The networks can be a single network or a concatenation of networks amongst two or more providers and private and public networks, and each of the network or components of the network may be either wired or wireless. Additionally, the method and system of the disclosed embodiments can use various forms of multicast techniques and/or protocols. In a preferred embodiment, Source Specific Multicast (SSM) is used since the source(s) of the multicast content is/are deterministic and known ahead of time. An SSM multicast channel (S, G) is dynamically assigned to a particular content stream (live) or content-object (non-live) that needs to be delivered. If source redundancy is needed for higher reliability, the Anycast sourcing technique as described above can be used. Choice of specific multicast technique and/or protocol is up to the network provider based on their own considerations. [0060] Although preferred embodiments have been described herein with reference to the accompanying drawings, it is to be understood that these embodiments are not limited to those precise embodiments and that various other changes and modifications may be effected herein by one skilled in the art without departing from the scope or spirit of these embodiments, and that it is intended to claim all such changes and modifications that fall within the scope of these embodiments.

A method, apparatus and computer-readable storage medium distribute a non-live content stream in a network. An initial meta-file is transmitted in response to a request for the content, which identifies a division of the content stream into blocks, and available sources for delivery of the blocks. The initial meta-file can identify a first multicast and a second multicast server, assigning a first and second portion of the blocks for delivery using the first and second multicast source server, respectively. The first and second portions are transmitted using the first and second multicast source servers, respectively. The first and second portions correspond to distinct non-overlapping portions of the non-live content stream. The initial meta-file can also identify a unicast source server, assigning a third portion of the blocks for delivery using the unicast source server, the third potion being transmitted by the unicast source server.

FIELD OF THE INVENTION The invention relates to an actuator with an electrically heatable thermostatic operating element heated by an electrical heating element and having a housing containing an expanding material and an operating piston that is extensible from the housing, the piston position being controlled by a proportional piston stroke regulator. BACKGROUND OF THE INVENTION An actuator of this type is known, for example, in German Patent Disclosure DE 41 38 523 A1. In that construction, the regulation of the position of the operating piston is based on the electrical resistance of the thermostatic operating element, which is assumed to vary as a function of the change in volume of the expanding material, so that the electrical resistance of the operating element corresponds to the position of the operating piston. This design is not totally reliable as changes in ambient temperatures, ambient pressures or combinations thereof potentially change the expansion for a given temperature as measured by the operating piston position since the electrical resistance measured is not truly proportional to the actual temperature. Furthermore, the starting ambient temperature surrounding the operating element would either have to be a constant, so the piston always started at the same position with the same corresponding measured electrical resistance, or the piston position would have to be re-calibrated before every use of the operating element. The operability of the exemplary embodiments with which an electrical resistance varying with the change in volume of the expanding material is to be detected is not always consistent with precise and accurate movement and regulation of the operating piston. OBJECT AND SUMMARY OF THE INVENTION It is the object of the present invention to provide an actuator with a way of precisely measuring and regulating the position of the operating piston. This object is attained by controlling the operating piston position with a proportional piston stroke regulator, which includes a piston travel detection device connected to a conventional closed-loop control circuit. The closed-loop control circuit compares the detected position of the operating piston with an entered pre-determined piston control position and regulates the electrical current supply to the electrical heating element accordingly. By the present invention, it is possible to provide very precise measurement and regulation of the operating piston position. In particular, very precise movement of the operating piston to pre-determined positions is possible. In a specific embodiment of the invention, the conventional closed-loop control circuit controls the supply of pulses of alternating current to the electrical heating element by the use of a relay, in particular a triac. By supplying the electrical heating element with an adjustable intermittent duration of pulses of electrical current, the electrically heatable thermostatic operating element behaves in the manner consistent with a proportional, integral, derivative (PID) controller, enabling very precise piston position regulation. Precision is enhanced if the operating temperature of the expanding material, that is, the temperature at which the expanding material begins to change from its original unheated state, is markedly above the ambient temperature, so that relatively rapid cooling and retraction of the operating piston occurs when the electrical heating element is not supplied with electrical current. In another specific embodiment of the invention, the maximum travel of an actuator element of a device to be actuated is determined and stored in the memory of the conventional closed-loop control circuit. It is thus possible within the closed-loop control circuit to detect the maximum travel of the device to be actuated, for example a tappet of a valve, and to evenly distribute the pre-determined piston control positions along the entire length of travel, for example between the opening position and the closing position of a tappet of a valve, thereby providing a number of adjustable positions available to the actuating element of the device to be actuated. In a specific structural embodiment of the invention, an outer housing encloses a stationary base body on which the electrically heatable thermostatic operating element, a motion transfer member moveable with the operating piston and the piston travel detection device are supported, the piston travel detection device being disposed between the motion transfer member and the outer housing or the base body. A preferred construction of the piston travel detection device includes a stationary element, mounted on the outer housing or the stationary base body, and a relative position element associated with the stationary element and moveable with the motion transfer device and the operating piston. In a specific feature of the structural embodiment of the invention, the relative position element moveable with the motion transfer device and the operating piston is disposed on a circuit board which is mounted on the motion transfer member. It is advantageous if the conventional closed-loop control circuit and the relay are disposed on the circuit board as well. Further characteristics and advantages of the invention will become apparent from the following description of the exemplary embodiment shown in the drawing. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of an actuator of the present invention; and FIG. 2 is a vertical sectional view of an actuator of the preferred structural embodiment of the present invention mounted on a flow valve, with the components in the position where the thermostatic operating element is unheated. DESCRIPTION OF THE PREFERRED EMBODIMENT The actuator shown in FIG. 1 includes an electrically heatable thermostatic operating element 10 having a metal housing 11 containing an expanding material, in particular a wax mixture, and a guide insert 12 secured to one end of the housing 11 through which an operating piston 13 extends outwardly from the housing. A flexible diaphragm internal to the housing 11 and sealingly attached to the upper edge of the housing 11 by the guide insert 12 , surrounds the operating piston 13 , isolating the operating piston 13 from the expanding material contained in the housing 11 . An electrical heating element 14 , such as a positive temperature coefficient (PTC) resistor, is located under the housing 11 of thermostatic operating element 10 . The electrical heating element 14 is connected to an electrical current source in the manner disclosed in U.S. Pat. No. 5,897,055 (German Patent Disclosure DE 197 05 721 A1). The electrical heating element 14 heats the thermostatic operating element 10 such that the expanding material increases its volume, thus in accordance with its increase in volume driving the operating piston 13 out of the housing 11 through the guide insert 12 . The operating temperature of the expanding material, in particular the temperature at which it changes from its unheated state, is defined as sufficiently high compared with the ambient temperature that rapid cooling occurs after the electrical current is removed from the electrical heating element 14 . For example, if the thermostatic operating element 10 is used in an area with the ambient temperature being room temperature (approximately 22° C.), then an operating temperature of 70.4° C. may be desired for the expanding material. The electrical heating element 14 is connected to a 24 V alternating current electrical source by an electrical supply line. A relay 15 , particularly a conventional triac, is integrated into the electrical supply line, enabling the electrical heating element 14 to be supplied with electrical power in pulses of adjustable intermittent duration. The relay 15 is operated by a conventional closed-loop controller 16 , which forms a closed-loop control circuit. Also connected to the closed-loop controller 16 is a piston travel detection device 17 moveable with the operating piston 13 . The piston travel detection device 17 transmits a signal to the closed-loop controller 16 corresponding to the detected position of the operating piston 13 . The detected position of the operating piston 13 is compared by the closed-loop controller 16 to a pre-determined piston control position entered into the closed-loop controller 16 . Any deviation between the detected position and the predetermined piston control position causes the closed-loop controller 16 to operate the relay 15 in such a way that pulses of electrical current are intermittently sent to or blocked from the electrical heating element 14 , sequentially energizing and de-energizing the electrical heating element 14 . The pre-determined piston control positions for the operating piston 13 are entered into the conventional closed-loop controller 16 as direct voltage values in a range between 0 V and 10 V. These direct voltage values are coordinated within the closed-loop controller 16 with the detected travel distance of the operating piston 13 , with the 10 V direct voltage value corresponding to the maximum travel of the operating piston 13 and the remaining predetermined piston control positions evenly distributed along the entire travel length of the operating piston 13 . This coordination of the direct voltage values and the travel of the operating piston 13 within the closed-loop controller 16 is achieved in the following manner. The conventional closed-loop controller 16 causes the electrical heating element 14 to be energized for a sufficient amount of time such that the expanding material of the thermostatic operating element 10 increases in volume, causing the operating piston 13 to engage and move the actuating element of the device to be actuated to its maximum point. For example, if the device to be actuated is a valve and the outward motion of the operating piston 13 acts to close the valve, then the travel of the valve and the operating piston 13 would be from the valve's open position to its closed position. On the other hand, if the device to be actuated is a valve tappet such that the outward motion of the operating piston 13 acts to open the valve tappet, then the travel of the device and the operating piston would be from the device's closed position to its open position. The maximum travel distance required of the operating piston 13 is registered when the actuating element of the device to be actuated reaches its maximum travel, and the corresponding maximum pre-determined piston control position is entered in the closed-loop controller 16 . The closed-loop controller 16 then causes the electrical heating element 14 to be de-energized, allowing the expanding material of the thermostatic operating element 10 to cool to ambient temperature, thereby decreasing in volume. The operating piston 13 is then forced back into the housing 11 by a compression spring, not shown in FIG. 1 . As the operating piston 13 withdraws into the housing 11 , the actuating element of the device to be actuated follows the operating piston 13 until the minimum position for the actuating element (open or closed) is reached. Thus the minimum distance required of the operating piston 13 is determined and the corresponding minimum pre-determined piston control position is entered in the closed-loop controller 16 . The remaining pre-determined piston control position direct voltages are distributed evenly along the travel length of the operating piston 13 . For example, if the maximum travel distance of the operating piston 13 was determined to be 2.5 mm and the minimum travel distance was 0 mm, then the maximum pre-determined control position entered would correspond to 2.5 mm, the minimum pre-determined control position entered would correspond to 0 mm, and the remaining pre-determined control positions would be entered to correspond to a travel distance of 0.25 mm for each voltage step (i.e., each 1 V is 0.25 mm). The maximum travel of the actuating element of the device to be actuated can be readjusted with little difficulty, making the actuator adaptable to any variations in the maximum travel distance of the actuating element. The pre-determined control positions for the operating piston 13 can be determined the first time electrical power is supplied to the electrical heating element 14 and readjusted after every power supply disruption. The piston travel detection device 17 can operate by a variety of conventional methods, including, but not limited to, the following: utilizing the Hall effect by using a magnetic field sensor; using the change in capacitance of a capacitor; by magnetoresistivity; as a system employing the Wiegand effect; and by an optical method using applied, detectable markings. The preferred method of the present invention employs a two-piece apparatus—a ferrite bar that penetrates into a electromagnetic coil to which an electrical voltage has been supplied. The distance in which the bar penetrates the coil creates a detectable change in inductance, corresponding to the change in the position of the operating piston 13 . The actuator shown in FIG. 2 corresponds generally to the actuator disclosed in U.S. Pat. No. 5,897,055 (German Patent Disclosure DE 197 05 721 A1), which is incorporated herein by reference. The actuator includes a base body member 24 , which can be secured by a union nut 23 to threads of a device to be actuated, such as a valve. As shown in FIG. 2, the actuator is mounted to a connection stub 22 integral to valve 19 by the union nut 23 , the actuator situated in a manner to engage and operate a valve tappet 20 which carries a valve plate 21 that is associated with a valve seat, not shown in detail, where the valve tappet 20 is biased by a compression spring 30 which opens the valve 19 when no external load is acting on the valve tappet 20 . A motion transfer member, assembled from two parts 26 , 27 is disposed on the base body member 24 for movement relative thereto, and the operating piston 13 of a thermostatic operating element 10 is in operable engagement therewith. The housing 11 of the thermostatic operating element 10 is supported in stationary fashion on the base body member 24 and is seated on an electrical heating element 14 , such as a positive temperature coefficient resistor (PTC), which is supported on the base body member 24 This PTC resistor is connected to an electric current source in the manner disclosed in U.S. Pat. No. 5,897,055 (German Patent Disclosure DE 197 05 721 A1). The thermostatic operating element 10 is oriented such that the operating piston 13 moves in a direction away from the union nut 23 when the operating element 10 is actuated. With this arrangement of the components, when the electrical heating element 14 is energized, it heats the operating element 10 to cause expansion of the wax mixture in the operating element 10 , thereby forcing the operating piston 13 outward, which in turn moves the motion transfer member, 26 , 27 against the bias of the compression spring 30 , which movement results in the motion transfer member 26 , 27 moving an actuating element of the device being actuated. The compression spring 30 is supported by an annular collar 35 disposed on one part 26 of the motion transfer member 26 , 27 and prestressed against an outer housing 31 . The outer housing 31 encloses the thermostatic operating element 10 including the operating piston 13 , heating element 14 , compression spring 30 , motion transfer member 26 , 27 and the base body member 24 . The outer housing 31 is secured to the base body member 24 . On its side toward the union nut 23 , the part 27 of the motion transfer member 26 , 27 penetrates the base body member 24 and includes a pressure plate 28 which forms a bearing face for the element to be actuated, in FIG. 2 a valve tappet 20 . A circuit board 29 is mounted on the face end of the part 26 of the motion transfer member 26 , 27 that is opposite the operating piston 13 . The piston travel detection device shown in FIG. 1 includes an electromagnetic coil 32 mounted on the surface of the circuit board 29 and a ferrite bar 33 secured to the inside surface of the top of the outer housing 31 . The ferrite bar 33 is positioned such that the ferrite bar 33 penetrates the electromagnetic coil 32 when the operating piston 13 moves outward, pushing the part 26 of the motion transfer member 26 , 27 toward the top of the outer housing 31 . The closed-loop controller and the relay are also disposed upon the circuit board 29 . A window 34 of transparent material is inserted into the outer housing 31 facing the annular collar 35 on the part 26 or the motion transfer member 26 , 27 such that it is possible to view the position and functioning of the actuator external of the outer housing 31 . It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof

An actuator for a device such as a tappet of a valve. The actuator having a thermostatic operating element electrically heated by an electrical heating element, and including an operating piston. A proportional piston stroke regulator detects and controls the position of the operating piston. The proportional piston stroke regulator includes a piston travel detection device, that detects the actual position of the operating piston, connected to a conventional closed-loop controller which compares the measured piston position to a predetermined piston control position entered into the closed-loop controller. Based on the comparison, the closed-loop controller regulates the electrical supply to the electrical heating element.

FIELD OF THE INVENTION [0001] The present invention relates to an apparatus for isolating oil from oilsand, oil shale, or contaminated soil, and for treating contaminated waste oil, and particularly relates to such an apparatus which is portable and the use of which is non-polluting. BACKGROUND OF THE INVENTION [0002] Vast amounts of hydrocarbon fuels are stored within geological structures known as oilsands and oilshale. As more easily extracted sources of hydrocarbon fuels are depleted, increasing attention is paid to methods for extraction of oil from oilsands and oilshale. [0003] Oilsand, also known as tarsand, is a naturally occurring mixture of sand or clay and bitumen, a dense hydrocarbon. The bitumen may be processed into usable oil. Worldwide reserves of oil from oilsand are estimated to exceed 3 trillion barrels. [0004] Oil shale is a fine-grain sedimentary rock containing a solid mixture of chemical compounds, known as kerogen, from which hydrocarbons may be extracted. Processing of oil shale can convert the kerogen into usable crude oil. Global deposits of oil from oil shale are estimated to be approximately 3 trillion barrels. [0005] Various systems and methods have been attempted to remove oil from soil, sand, or other earthen materials. One of these devices is shown in U.S. Pat. No. 5,193,291, which teaches a conventional “baghouse” system wherein the contaminated soil is heated directly by a gas furnace flame. The heated soil is then discharged into the baghouse for subsequent separation and discharge. U.S. Pat. No. 5,272,833 shows a similar apparatus and process for remediating contaminated soil. This system is also a baghouse-type system. [0006] U.S. Pat. No. 5,188,041 discloses a soil remediation process comprising passing non-oxidizing heated gases over the contaminated soil at a flow rate and temperature to prevent surface drying of the contaminated soil. This system is specifically a low-temperature system, and therefore is incapable of effectively isolating oil from oilsands or oilshale. [0007] U.S. Pat. No. 5,004,486 discloses a gas cleaning system that directs the exhaust gas from the combustion chamber through a heat exchanger for cooling the gas, and into a bubbling dust separator submerged under water in order to discharge the gas directly into the water for the prevention of air pollution. [0008] U.S. Pat. No. 5,273,355 discloses a rotary drum mechanism for incinerating soil and mixing the soil with heated and dried stone aggregate for the production of asphalt paving. The gas products of combustion from the incinerator are directed into the rotary drum to be further combusted prior to direct discharge into the atmosphere. [0009] U.S. Pat. No. 5,302,118 discloses a soil remediation system comprising a rotary drum having a burner flame directed into one end of the drum, as in U.S. Pat. No. 5,193,291. In addition, as in the '291 patent, the '118 patent includes the baghouse-type collection mechanism for collecting dust to prevent its release into the atmosphere. [0010] Much oil is used for non-fuel purposes as well. Once used, such oil is often contaminated with metals and other contaminants which may be harmful to and inefficient for machinery. In order to reuse such contaminated oil, it is necessary to isolate the oil from the contaminants. [0011] The prior art methods of oil isolation from oil-rich materials or oil decontamination may require use of water, require addition of harmful chemicals, or cause air pollution or accumulation of toxic waste. It would be desirable to have a method and apparatus for isolation of oil from oil sand and oil shale, and for decontamination of used oil, which does not require water or addition of chemicals, and which is environmentally benign. SUMMARY OF THE INVENTION [0012] According to one embodiment of the present invention, there is provided a portable oil isolation and decontamination system comprising a plurality of high heat energy generators that supply high heat energy to an oil isolation and decontamination unit. Each heat energy generator comprises a chamber for gasifying used rubber tires, waste oil, coal or other combustible materials for the production of volatile gases and high energy heat. The oil extractor unit comprises a pair of parallel, elongate rotating cylinders that each rotate within a common closed housing. Oil-rich material such as oilsands, oilshale, contaminated soil or used oil is introduced into one end of each rotating cylinder and is caused to migrate to the opposite end in cascading fashion as the cylinder rotates. High energy heat from the generators is directed at the rotating cylinders to indirectly heat the oil-rich material therein to vaporize the hydrocarbons as the rotating drum migrates the oil-rich material towards its collection end. Vacuum pressure withdraws the vaporized hydrocarbons from the cylinder, and the cleaned sand or other solid material exits the collection end of each rotating cylinder and housing. The vaporized hydrocarbons condense and are collected within a forced-air condenser for recycling. An optional second stage refrigeration unit condenses any residual vaporized hydrocarbons that may be missed by the forced-air condenser. [0013] In one of its aspects, the present invention comprises an oil isolation and decontamination apparatus for processing oil-rich material, comprising at least one heat energy generator, each heat energy generator comprising a vaporization chamber for receiving and holding waste materials to be vaporized; air supply means for supplying air under slight pressure into the vaporization chamber; fuel supply means for supplying fuel into the vaporization chamber; a volatile gas withdrawal manifold communicating with the vaporization chamber for withdrawing volatile gases from the vaporization chamber; a mixing chamber having a volatile gas inlet communicating with the volatile gas withdrawal manifold, air pressure means for introducing pressurized air thereinto, a fuel injector, and ignition means for igniting a gas fuel air mixture, and an outlet; and a combustion chamber that communicates with the mixing chamber outlet, the combustion chamber having an outlet; an oil extractor, comprising: a housing communicating with the combustion chamber outlet, whereby ignited gas/fuel/air mixture acts directly into the interior of the housing; a first rotary drum mounted for rotation about its longitudinal axis within the housing, the drum having an inlet and an outlet adjacent opposite ends thereof; a second rotary drum parallel to the first rotary drum mounted for rotation about its longitudinal axis within the housing, the drum having an inlet and an outlet adjacent opposite ends thereof; vane means within the rotary drum for migrating an introduced oil-rich material within the drum as the drum rotates; a discharge outlet formed in the housing adjacent the drum outlet for discharging the housing; and a vapor discharge outlet for withdrawing volatile vapors from the oil-rich material; and a hydrocarbon recovery system comprising: a housing having a hydrocarbon vapor inlet communicating with the vapor discharge outlet, and an exhaust gas outlet; and condensing means for condensing the hydrocarbon vapor from exhaust gases. [0014] The apparatus may be mounted on a wheeled vehicle for portability, and each heat energy generator and the hydrocarbon recovery system may be mounted on skids for portability. [0015] A dust collector may be intermediate the oil extractor and hydrocarbon recovery system for filtering the vaporized hydrocarbon and exhaust gases prior to condensation and separation of the hydrocarbons from the exhaust gases. It may also include a second-stage hydrocarbon recovery system comprising a water-cooled condensor and refrigeration heat exchanger. The apparatus may use four heat energy generators. [0016] The heat energy generator vaporization chamber and the oil extractor housing may have linings of a refractory material. The rotational longitudinal axis of each oil extractor rotary drum may be inclined relative to horizontal, with the drum inlet adjacent the higher end and the drum outlet adjacent the lower end. [0017] The vaporization chamber may have several openings in at least one wall. Each of the openings may have a diameter of between 2.5 and 3.5 inches. Ideally, there are 12 openings in the chamber. The volatile gas withdrawal manifold of each heat energy generator may be disposed at an elevation higher than the elevations of the air supply means and fuel supply means. The air supply means of each heat energy generator may be manually adjustable for controlling the amount of air being supplied into the vaporization chamber for combustion. [0018] According to another embodiment, the present invention provides use of the aforementioned apparatus to produce useable oil from an oil-rich material. The oil-rich material may be oilsand, oil shale, contaminated soil or waste oil products. BRIEF DESCRIPTION OF THE DRAWINGS [0019] A detailed description of the preferred embodiments is provided below by way of example only and with reference to the following drawings, in which: [0020] FIG. 1 is a schematic diagram of the oil isolation and decontamination apparatus of the present invention; [0021] FIG. 2 is a side elevation view of the first stage of the apparatus of the present invention; [0022] FIG. 3 is a top view of the first stage of the apparatus; [0023] FIG. 4 is a cross-sectional view of the first stage of the apparatus, through line 4 - 4 of FIG. 2 ; [0024] FIG. 5 is a cross-sectional view through the second stage of the apparatus; [0025] FIG. 5B is a cross-sectional view of another embodiment of the invention, through the second stage of the apparatus; [0026] FIG. 6 is a cross-sectional view through the rotating drum and housing; [0027] FIG. 7 is a cross-sectional view taken along lines 7 - 7 in FIG. 5 , illustrating the interior vanes for creating the migration of the soil to be processed through the rotating drum; [0028] FIG. 7B is an end view of the end plates of the parallel rotating drums of the apparatus; [0029] FIG. 8 is a side view of the third stage of the apparatus, specifically the condensor for condensing and reclaiming the hydrocarbon products from the volatile gases exhausted from the oil-rich material; [0030] FIG. 9 is an end view of the condensing unit of FIG. 8 , taken along lines 9 - 9 in FIG. 8 , and illustrating the flow of ambient temperature air through the condensing tubes; [0031] FIG. 10 is a cross-sectional view illustrating the flow of exhaust gases through the condenser, taken along line 10 - 10 in FIG. 8 ; [0032] FIG. 11 is a schematic diagram of the optional second stage of the condensing unit, illustrating the glycol and water condensing system, the heat exchanger, and the freon refrigeration unit; and [0033] FIG. 12 is a schematic of the cooling system of the invention. [0034] In the drawings, one embodiment of the invention is illustrated by way of example. It is to be expressly understood that the description and drawings are only for the purpose of illustration and as an aid to understanding, and are not intended as a definition of the limits of the invention. DETAILED DESCRIPTION OF THE INVENTION [0035] In the following detailed description of the invention, reference numerals are used to identify structural elements, portions of elements, or surfaces in the drawings, as such elements, portions or surfaces may be further described or explained by the entire written specification. For consistency, whenever the same numeral is used in different drawings, it indicates the same element, portion, surface and area as when first used. It should be understood that only those components having particular functional importance or that would not otherwise be identified have been assigned reference numerals. [0036] The oil isolation and decontamination apparatus of the present invention comprises a three-stage system. The first stage is a combustion chamber that combusts waste materials such as used vehicle rubber tires into high energy heat by gasification in a continuous-burn cycle. [0037] The heat energy from the first stage is fed into the second stage, which is a rotating drum that rotates within a closed chamber. The heat energy is directed into the chamber directly against the drum. The rotating drum contains the oilsand, oilshale or contaminated oil to be isolated and decontaminated by the high heat from the combustion chamber. This high heat is applied to the oilsand, oilshale or contaminated oil indirectly so that the hydrocarbons within the soil may be vaporized without burning the soil. [0038] The volatile hydrocarbon vapors are then drawn off and introduced into the third stage, which is an air-cooled condenser and hydrocarbon recovery system. This recovery system condenses the hydrocarbon vapors from the volatile exhaust gases to permit reclamation of the hydrocarbons and a clean exhaust gas to be emitted into the atmosphere. [0039] Referring now to the drawings, and initially to FIG. 1 , the system of the present invention is shown schematically. In the schematic of FIG. 1 , a control room 1 provides a central location for operation of the system. A horizontal trammel unit is shown at 10 . Each trammel unit includes a pair of internally rotating drums 12 for receiving the oilsand, oil shale, contaminated soil or contaminated oil (hereafter, collectively, the “oil-rich material”) to be processed into one end thereof, the material to migrate through the rotating drum during processing thereof, and be expelled from the opposite end of the trammel. Oil-rich material is placed into an auger 78 , from which it passes on a conveyor 79 to hopper 78 A a pair of adjacent augers 80 . The material exiting each auger passes into a corresponding rotating drum 12 within a common trammel unit housing 10 . [0040] Heat energy for treating the oil-rich material within the horizontal trammel unit 10 is provided by a plurality of high heat energy units 14 . Fuel for the heat energy units may be provided by used rubber tires, waste oil 11 or other fuel sources. Ignition of the fuel in the heat energy generators may be provided by a propane source 15 . These heat energy units inject heat directly into the horizontal trammel unit to act directly on the internal rotating drums 12 and, therefore, indirectly on the oil-rich material to be processed. Residual soil, sand or other solids remaining after removal of volatile hydrocarbons are deposited in a temporary storage location 17 for removal or return to their source. [0041] Volatile hydrocarbon vapors emitted from the oil-rich material as it is being processed are drawn from the horizontal trammel unit 10 , and passed using a blower 5 through a dust collector, an oil tank 7 and a water tank 9 prior to entering a forced-air condensor and recovery unit 18 . The volatile hydrocarbon vapors are condensed in the condensor and recovery unit 18 for subsequent storage in a holding tank 13 and removal, leaving the cleaned exhaust gas to be drawn through an optional second condensor unit for further condensing of any remaining hydrocarbon vapors within the exhaust gas. Each of the elements of the apparatus of the present invention will be described in detail hereinbelow in the order of progression through the system. [0042] With reference now to FIG. 2 , the high heat energy unit 14 is shown in side elevation. The heat energy unit 14 comprises a gasification furnace 22 for receiving therein waste materials, as in used vehicle tires, for incineration by dry distillation and gasification. The gasification furnace 22 is a closed system, incorporating a sealable lid 24 that seals the contents of the furnace from the atmosphere. With the furnace 22 filled with used vehicle tires, the lid 24 is sealed down thereagainst and the ignition process is begun. [0043] A blower 26 is mounted on one side of the furnace 22 and injects air from the atmosphere into a manifold 28 for distribution to three sides and the bottom of the furnace. The manifold 28 includes a plurality of conduits 30 that direct the pressurized air into the interior of the gasification furnace 22 . One of the conduits connects the manifold 28 with an opening in the bottom of the furnace to inject air into the furnace at the approximate geometric center thereof. Another conduit 32 may direct air into a plenum 34 that carries air around to opposite sides of the furnace and injects air from the manifold into the furnace at a plurality of openings along the plenum (not shown). Another conduit 36 may direct air from the manifold 28 into the side of the furnace shown in FIG. 2 and this conduit may include a controllable injector 38 for injecting propane directly to the interior of the furnace for initially igniting the tires therein. The propane injector 38 also includes an electric igniter for initially igniting the propane injected into the furnace. Air flow into the furnace is controlled by a plurality of valves 40 within the various conduits. [0044] The furnace also includes a plurality of openings on its sides to permit adequate oxygen flow to achieve the high temperatures desired. Ideally, at least 12 openings 41 of approximately 3 inches in diameter are provided in the sided of the furnace. The plurality of openings permits improved combustion and greater efficiency. The effect of this is to allow a wide variety of fuels to be burned. The fuels may include used rubber vehicle tires, coal, waste oil, or other materials. This increase in efficiency also permits use of smaller heat generators than in the prior art. [0045] In operation, with the gasification furnace 22 filled with used tires and sealed, the blower 26 introduces air (oxygen) into the furnace at a plurality of locations adjacent the lower portion of the furnace. Propane is injected into the furnace and ignited by the propane injector 38 , and, along with the inflow of air (oxygen) from the blower 26 , ignites the waste tires. When a sufficient operating temperature is reached, further propane is unnecessary to maintain combustion of the tires within the furnace. The inflow of air into the furnace is controlled to maintain sufficient oxygen to permit the tires and other waste material to maintain combustion in a continuous-burn mode, and gasify the waste material through dry distillation. Adequate oxygen supply is provided by a plurality of openings in the side of the furnace, as indicated in FIG. 2 . [0046] In order to efficiently maintain a temperature of up to 3700° F. to sustain combustion and dry distillation of the waste tires, the gasification furnace 22 includes a refractory lining approximately two inches thick to accommodate greater sustained heat generation. The sealable lid 24 includes a similar refractory lining. [0047] As the gasification furnace 22 is a closed system, as the used tires combust and vaporize, volatile gases are generated within the furnace. These volatile gases are permitted to exhaust from the furnace via a plurality of openings (not shown) from the interior of the furnace into a second manifold 42 , positioned slightly above the various inlets of atmospheric air into the furnace from the blower 26 . The manifold 42 collects these volatile gases and directs them into a mixing chamber 44 for mixing with additional air (oxygen) prior to further combustion. This mixing chamber is more clearly shown in FIGS. 3 and 4 . [0048] FIG. 3 is a top view of the first stage device of oil isolation and decontamination system, illustrating the relative positions of the furnace and the various manifolds and conduits associated therewith, and the mixing chamber and combustion chamber. As shown, the second manifold 42 directs volatile gases exhausting from the gasification furnace 22 directly into the mixing chamber 44 . The interior of the mixing chamber is best shown in FIG. 4 . The mixing chamber comprises an outer enclosure 46 , preferably circular, and having an intermediate conduit 48 therein in essentially axial concentricity. A short robe 50 provides communication between the interiors of the second manifold 42 and the intermediate conduit 48 , so that the volatile exhaust gases from the furnace 22 are directed into the interior of the intermediate conduit 48 . An inner conduit 52 is positioned concentrically within the intermediate conduit 48 , and is connected to a second blower 54 for introducing air from the atmosphere directly into the mixing chamber 44 . [0049] Volatile gases from the furnace 22 flow through the second manifold 42 , into the interior of the intermediate conduit 48 , and directly into a combustion chamber 56 , as shown in FIG. 4 . Pressurized air provided by the blower 54 is forced through the inner conduit 52 and exits at a location adjacent that of the volatile gases from the furnace exiting the intermediate conduit 48 . Air flow through the inner conduit 52 mixes with the volatile gases, and this gas-air mixture flows into the combustion chamber 56 . [0050] The outer enclosure 46 includes a second propane injector 58 and igniter 60 . When the system is initially started, propane is injected into the air-volatile gas mixture, and then ignited by the igniter to create combustion in the combustion chamber 56 . Once this mixture has been ignited, the propane is shut off, and the volatile gas and air mixture continues to combust in the combustion chamber. [0051] Referring again to FIGS. 2 and 3 , the furnace, its associated manifolds, air injectors, etc., and the mixing chamber 44 and combustion chamber 56 are shown mounted on a pair of skid rails 62 . In this manner, the first stage of the apparatus of the present invention can be readily transported, along with the remaining stages, to a desired site for direct on-site processing of oil-rich material. [0052] As shown in FIG. 1 , four high heat energy units 14 , as shown in detail in FIGS. 2-4 . The combustion chamber 56 of each unit is attached directly into the side of the second stage of the system, specifically the horizontal trammel unit 10 . [0053] Turning now to FIG. 5 , the horizontal trammel unit 10 is shown in vertical section. The trammel includes the internal rotating drum 12 that rotates on trunions 70 on the left and 72 on the right. The rotating drum 12 rotates concentrically about its longitudinal axis within a longitudinal insulated shell 74 into which the combustion chambers 56 from the heat energy units 14 direct their respective blasts of ignited volatile gas and air mixtures. [0054] The rotating drum 12 is essentially a closed drum, open only at one end (the right end as shown in FIG. 5 ) for the introduction of contaminated oil-rich material thereinto, and the withdrawal of hydrocarbon vapors therefrom. In addition, the drum includes two openings adjacent the opposite end (the left end as shown in FIG. 5 ), which permit the processed sand or other solids to drop out therefrom as the drum rotates. [0055] In operation, four respective combustion chambers 56 may be attached directly to the insulated shell 74 of the trammel unit as indicated in FIG. 1 . Specifically, each combustion chamber 56 attaches to the shell 74 at a respective inlet 76 for injecting heat from the high heat energy units 14 directly into the annular space within the insulated shell and around the rotating drums, in order to indirectly heat the oil-rich material as the material migrates through the drum. Oil-rich material is introduced into each rotating drum via a hopper 78 and a pair of augers 80 which transport the oil-rich material directly into the interior of each drum at the right end as shown at FIG. 5 . [0056] FIG. 6 is a vertical plan view taken on the right hand side in FIG. 5 , and more clearly illustrates how each auger 80 introduces the oil-rich material into each rotating drum 12 . Each rotating drum 12 is supported by, and rotates on, trunnions 72 along its outside diameter. Each drum includes an externally toothed ring 82 formed therewith, and by which the drum is rotated via a drive gear mechanism 84 . A stationary cylindrical section 86 (best shown in FIG. 5 ) is positioned within the toothed ring 82 such that the ring rotates around the cylindrical section 86 . [0057] The cylindrical section 86 is closed at one end (the right end as shown in FIG. 5 ) by an end plate 88 which has openings therein for the auger 80 and two hydrocarbon vapor suction conduits 90 . The stationary cylindrical section 86 is supported on the platform by brace 92 . [0058] Each rotating drum 12 is supported at its opposite end (the left end as shown in FIG. 5 ) by a hollow bushing 94 formed with the end plate 96 of the drum. The hollow bushing 94 is supported by and rotates on trunnion 70 in a customary manner. The hollow bushing provides communication between the interior of the rotating drum and a separate conduit 98 within the interior of the insulated shell. The conduit 98 is open to the interior of the shell at the upper end thereof (the right end as shown in FIG. 5 ) when the system is operating. The function of the open conduit 98 within the trammel unit insulated shell will be explained in greater detail hereinbelow. [0059] FIG. 7 illustrates the plurality of vanes 100 within the rotating drum that cause the oil-rich material to migrate along the inner diameter of each drum as the drum rotates. The direction of migration of the oil-rich material within the drum is from right to left as shown in FIG. 5 . As the drum rotates, these vanes function to lift individual portions of the oil-rich material and cause it to cascade and disburse as it slowly migrates from right to left within the drum. As each drum is inclined slightly downwardly at its left end, the tumbling effect of the oil-rich material within the drum caused by the vanes causes the oil-rich material to slowly migrate toward the left end of the drum, as it is being constantly rotated, heated, cascaded, agitated, and migrated by the tumbling effect of the drum. [0060] Each drum includes at least one exit opening (not clearly shown) adjacent the left end thereof that permits a certain amount of processed soil to drop therefrom with each revolution of the drum. In practice, this exit opening takes the form of a rectangular opening adjacent the drum end plate 96 . The longitudinal insulated shell 74 includes a similar opening in the bottom thereof aligned with the opening in the rotating drum so that the processed sand or other solid material may drop directly therethrough and onto a conveyor belt or similar for transportation if desired. [0061] One or more hydrocarbon vapor suction conduits 90 draw the vaporized hydrocarbons that are vaporized in the process from within the interior of each rotating drum to the third stage of the system, the hydrocarbon condensor. The vacuum pressure that draws the vaporized hydrocarbons from the oil-rich material within each rotating drum also draws a certain amount of high temperature exhaust generated by the high heat energy units 14 from the annulus around the rotating drums through the conduit 98 and hollow bushing 94 into the interior of each rotating drum in order to facilitate, by direct heat, further vaporization of the hydrocarbon contaminants within the oil-rich material. Specifically, the heat blasting from the combustion chambers 56 into the insulated shell 74 surrounds the rotating drums and directly heats the rotating drums to indirectly heat the oil-rich material therein. As this heat from the combustion chambers is under pressure, the pressure within the insulated shell 74 is permitted to escape through the separate conduit 98 and the hollow bushing 94 into the interior of the rotating drum facilitate the vaporization of the hydrocarbons from the oil-rich material. The vacuum applied at the hydrocarbon vapor suction conduits 90 draws the vaporized hydrocarbons from the interior of the rotating drums, through the dust collector 16 and into the forced-air condensor and recovery unit 18 , as shown in the schematic of FIG. 1 . [0062] FIG. 8 is a side view of the third stage of the oil isolation and decontamination system, comprising the forced-air condensor for condensing and reclaiming hydrocarbon products from the vaporized hydrocarbon gases exhausted from the oil-rich material within the rotating drum. The forced-air condensing and recovery unit 18 comprises a closed housing 110 having a plurality of conduits (pipes) 112 passing therethrough longitudinally. This is more clearly shown in FIGS. 9 and 10 . The housing 110 includes an inlet 114 for the introduction of the vaporized hydrocarbons and exhaust gases from the horizontal trammel unit 10 , and an outlet 116 for the exhaust gases remaining after the hydrocarbons have been condensed within the forced-air condensing unit. [0063] As best shown in FIG. 9 , the forced-air condensing and recovery unit includes the plurality of pipes 112 passing longitudinally therethrough. Cold air flows through these pipes under pressure from a fan and shroud 118 at the opposite end of the unit (at the left end as shown in FIGS. 8 and 10 ) to cause the vaporized hydrocarbons in the exhaust gases to condense on the outside of the pipes within the housing 110 . As shown in FIG. 8 , the bottom of the condensing and recovery unit 18 is slopped downwardly toward the left to permit the condensed hydrocarbons to be collected and periodically drained from the collecting pan. [0064] FIG. 10 illustrates the serpentine pattern that the vaporized hydrocarbons and exhaust gases follow as the exhaust gases flow through the forced-air condensing and recovery unit. This serpentine pattern is created by a plurality of baffles 120 within the housing 110 . As can be appreciated, these baffles are vertical, and span the entire height from top to bottom within the forced-air condensing and recovery unit housing 110 . In addition, as with the high heat energy units 14 , the forced-air condensing and recovery unit 18 includes skids 122 to enable the unit to be easily transported and attached to the conduits that interconnect the various elements of the system. [0065] It should be appreciated that the forced-air condensing and recovery unit uses air at ambient temperature for condensing the vaporized hydrocarbons from the exhaust gases. In most instances, this works quite well to recover essentially all of the vaporized hydrocarbons from the exhaust gases. In unusually warm climates, however, air at ambient temperature may not be adequate to fully condense all of the vaporized hydrocarbons from the exhaust gases. In these instances, a second stage in the condensing process may be utilized. This second stage is shown schematically in FIG. 11 , and can be referred to as a chiller. [0066] Exhaust gases from the forced-air condensing and recovery unit 18 that still contain trace amounts of vaporized hydrocarbons are drawn through a closed collection unit 130 at inlet 132 . The collection unit 130 includes a series of condensing coils, shown schematically at 134 . The vaporized hydrocarbons pass through the condensing coils 134 and are condensed on the coils and collect at the bottom of the collection unit 130 for periodic removal. The remaining clean exhaust gases exit the closed collection unit at the outlet 136 to be exhausted to atmosphere. [0067] The condensing coils 134 communicate directly with a heat exchanger 140 to transfer heat from the condensing hydrocarbons to the heat exchanger. These condensing coils 134 carry a mixture of 30% glycol and water, maintained at approximately 30° F. The heat exchanger 140 transfers heat from the glycol and water mixture to a conventional refrigeration circuit 142 that draws heat and distributes it to atmosphere in a conventional manner. [0068] Whether the oil isolation and decontamination system of the present invention utilizes only the forced-air condenser shown in FIGS. 8-10 , or both the forced-air condenser and the refrigeration unit chiller of FIG. 11 , exhaust gases are drawn through the system by an exhaust fan 144 located at the point of exhaust to the atmosphere. In either configuration, the exhaust fan provides the vacuum to draw the vaporized hydrocarbons through the system for condensation and reclamation, and exhausts the cleaned gases to atmosphere. [0069] It is to be noted that the apparatus of the present invention provides a means of isolation and decontamination of oil from oilsand, oil shale, or other oil-rich material without the use of water or the addition of chemicals which may be harmful to the environment. [0070] From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objectives herein set forth, together with other advantages which are obvious and which are inherent to the apparatus. It will be understood that certain features and sub-combinations are of utility and may be employed with reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims. As many possible embodiments may be made of the invention without departing from the scope of the claims. It is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. It will be appreciated by those skilled in the art that other variations of the preferred embodiment may also be practised without departing from the scope of the invention.

There is provided a portable oil isolation and decontamination system comprising a plurality of high heat energy generators that supply high heat energy to an oil isolation and decontamination unit. Each heat energy generator comprises a chamber for gasifying used rubber tires, waste oil, coal or other combustible materials for the production of volatile gases and high energy heat. The oil extractor unit comprises a pair of parallel, elongate rotating cylinders that each rotate within a common closed housing. Oil-rich material such as oilsands, oilshale, contaminated soil or used oil is introduced into one end of each rotating cylinder and is caused to migrate to the opposite end in cascading fashion as the cylinder rotates. High energy heat from the generators is directed at the rotating cylinders to indirectly heat the oil-rich material therein to vaporize the hydrocarbons as the rotating drum migrates the oil-rich material towards its collection end. Vacuum pressure withdraws the vaporized hydrocarbons from the cylinder, and the cleaned sand or other solid material exits the collection end of each rotating cylinder and housing. The vaporized hydrocarbons condense and are collected within a forced-air condenser for recycling. An optional second stage refrigeration unit condenses any residual vaporized hydrocarbons that may be missed by the forced-air condenser.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to digital imaging, and more specifically, creating high-quality S-parameter images in real-time. [0003] 2. Background [0004] Positrons are known for their sensitivity to vacancy type defects in solids. Using Doppler broadening spectroscopy, the shape of the 511 keV annihilation line, as represented through the S-parameter, provides a helpful measure of neutral and negatively charged vacancy defects. S-parameter imaging of a wafer surface by laterally scanning a point source of positrons across the wafer surface can provide useful information regarding the density of bulk defects in the wafer. Such scans have been made in the past by moving a radioactive source or a positron beam across a wafer. In this method, the beam or radioactive source is kept fixed and one point on the sample is exposed to that radiation for some fixed time and all annihilation events are then recorded for that point before moving on to the next point. The next point is then exposed to the positron radiation and so on until the whole sample surface has been scanned. The whole data set is finally processed off-line as per the requirement and is finally plotted in the form of an S-parameter graph using plotting software. BRIEF SUMMARY OF THE INVENTION [0005] There are at least four major draw backs of the standard imaging method. The first drawback is that the image can only be visualized after the completion of the entire surface scanning, which takes typically a few days for storing sufficient information to produce a good quality image. Using this method it is quite possible to collect data for a longer than necessary period if the S-parameter features of the sample turn out to have good S-parameter contrast. In some cases of prominent defect profile, even with less data at each pixel point it may still be possible to make a nice inference. [0006] The second drawback is that analyzing the image with any graphing software is always static. In such a system, one cannot dynamically interact with the visualization process. [0007] Third, there is no global monitoring of the image during the data taking process. For example, the right justification of the sample with respect to the scanning source/beam may be in error. Such an error can only be picked up after a completed sequential rectilinear scan had been made. Thus, much time can be wasted in improper positioning of the sample. [0008] Finally, even those research groups having a positron beam are restrained to moving the sample using a mechanical system. This means that there will always be a possibility of some mechanical backlash. [0009] In contrast, the present system works preferably by parallel rapid and continuous rastering of the whole sample surface, with information at each pixel location being built up at the same time. Alternatively, sequential point-by-point accumulation of data is used. The present system is supported by imaging software that allows the user to monitor the image build-up online in a dynamic and interactive mode that facilitates the formation of a good quality image of the sample in the shortest possible time. This system is useable with a 22 Na source as well as a sub-millimeter diameter positron beam. The imager system has many more features that will be discussed below. [0010] Disclosed is a real-time automated imaging system for solid state technologists that permits the location of subsurface defects on any material sample by reading its positron image. This S-parameter imaging technology employs a technique for scanning the sample surface in ‘parallel-rapid rastering’ mode. The electronic setup for signaling and data processing utilizes nuclear instrumentation modules in such a way so as to optimize the accuracy, precision and efficiency of data collection. Further, according to one embodiment, the data acquisition and image processing is performed in real time. This technology has been developed for two major categories of researchers, those that have a focused low energy positron beam and those that do not. With this S-parameter imager, all the drawbacks of the existing techniques discussed above have been overcome. [0011] The major advantages may briefly be listed as: (i) the rapid and repetitive scanning of different points of the sample one after another for the whole surface; (ii) the data is processing in real time with concurrent on-line image construction; (iii) image features can be seen quickly; (iv) electromagnetic deflection of the positron beam permits fast rastering for more advantageous configuration of a fixed sample; (v) electromagnetic deflection of the positron beam eliminates possible backlash of a moving sample stage; (vi) the imaging software permits the user to monitor various important hardware functions so as to check on the primary data fidelity and to permit necessary adjustments as required; (vii) the software is interactive and user friendly; (viii) the software gives the freedom to the user to monitor all setups and image quality; (ix) the user can continue to scan the sample until satisfied with the image quality; (x) optimal resolution which is a big factor in image analysis is also taken care of. BRIEF DESCRIPTION OF DRAWING [0012] FIG. 1A is a layout of a source and scanning setup together with wafer and detector: side view. [0013] FIG. 1B is a top view of the source and scanning setup together with wafer and detector showing motion of the source. [0014] FIG. 2 is a block diagram showing one embodiment of the Electronics setup of the Imager. [0015] FIG. 3 is a ‘virtual instrument diagram/program’ depicting the system software written in LabVIEW, a graphical programming language. [0016] FIG. 4 is a depiction of a Front Panel of the LabView given in FIG. 3 . [0017] FIG. 5 is a side view of the XY deflection coils. [0018] FIG. 6 is a cross-sectional view of the XY steering coils. [0019] FIG. 7 is a block diagram of one embodiment of the imager as applied to the low energy positron beam. [0020] FIG. 8A is a photograph of e + symbol made up of 0.5 mm thick kapton foil and pasted on the surface of silicon wafer. [0021] FIG. 8B is an S-parameter image of the kapton e + symbol depicted in FIG. 8A . [0022] FIG. 9A is a photograph of monocrystalline Ni sample. [0023] FIG. 9B is an S-parameter image of the sample described in FIG. 9A . [0024] FIG. 9C is a bar-chart plotting of the S-parameter value versus the pixel number with the data values taken along row 55 from FIG. 9B . [0025] FIG. 10A represents an X deflection signal for the beam application according to one embodiment of the disclosed device. [0026] FIG. 10B represents a Y deflection signal for the beam application according to one embodiment of the disclosed device. [0027] FIG. 11 represents one embodiment of a sample holder. [0028] FIG. 12 is a block diagram of the imager setup. [0029] FIG. 13A is a side view of the scanning apparatus. [0030] FIG. 13B is a top view of the scanning apparatus. [0031] FIG. 14A is a LabVIEW VI diagram for the library available sub-vi, DIO CONFIG.vi. [0032] FIG. 14B is a LabVIEW VI front panel for the VI given in FIG. 14A . [0033] FIG. 15A is a LabVIEW VI diagram for the library available sub-vi, DIO START.vi. [0034] FIG. 15B is a LabVIEW VI front panel for the VI given in FIG. 15A . [0035] FIG. 16A is a LabVIEW VI diagram for the library available sub-vi, DIO READ.vi. [0036] FIG. 16B is a LabVIEW VI front panel for the VI given in FIG. 16A . [0037] FIG. 17A is a LabVIEW VI diagram for high resolution (pixel) to low resolution image conversion sub-VI. [0038] FIG. 17B is a LabVIEW front panel for the VI given in FIG. 17A . [0039] FIG. 18 (A) is an S-parameter image of GaAs wafer size 3 cm×3 cm. [0000] The image resolution is 128×128 pixels taken with stepper motor step width 3.6 degrees. (B) S-parameter image of GaAs wafer of size 3 cm×3 cm. Image resolution is 64×64 pixels and image is taken with stepper motor step width 3.6 degrees. (C) S-parameter values plotted against the corresponding pixel number in row 29 of FIG. 18 b. [0040] FIG. 19A is the figure ‘C’ is a 0.4 μm Al thin film deposited upon a Cu substrate. [0041] FIG. 19B is an S-parameter image (of the figure C described in FIG. 23 ), imaged with a slow positron beam of spot diameter 1.5 mm. [0042] FIG. 20 is the flow chat of the complete system software. DETAILED DESCRIPTION [0043] A positron scanning setup shown in FIG. 1 comprises a positron source fixed to a holder arm that uses a rastering action across a sample. The resulting annihilation photons are detected by a detector. In one embodiment, the positron source comprises a 22 Na source encapsulated in a Kapton foil. The source has a strength of approximately 5 μCi and preferably a diameter of about 0.5 mm. In one embodiment, the source holder angle is approximately 60 degrees from the sample's normal so as to avoid any possible walling above the source where the positrons might be reflected back towards the sample or annihilate in other material other than that of the sample. [0044] In a first embodiment, the holder has a square hole, while in other embodiments the hole can be rectangular, oval, round, etc. There is a thin plastic film/self adhesive tape/cello-tape fixed across the bottom part of the hole in angle holder, as shown in FIG. 11 . Preferably, the self adhesive tape has a 1 cm diameter hole. [0045] As discussed above, the source is encapsulated in a kapton foil. The kapton piece is fixed below the self adhesive tape, on the paste side, so the source (black spot) is kept at approximately the center of the hole in the self adhesive tape. In one embodiment, the source is fixed around the center of the hole in the self adhesive tape and fixed to the holder such that its bottom part is free of any obstruction while not hindering the downward moving positrons. Also, the hole gives freedom to all upward moving positrons to disperse and annihilate at some distance from the detector, rather than being scattered/reflected towards the sample. Preferably, the source moves to about 0.5 mm above the sample surface to avoid spreading of the positrons. A high purity germanium (HP Ge) detector is attached at an adjustable distance (typically 5 cm) below the sample in accordance with required data rates. The distance is measured between the sample surface and the axis of the cylindrical detector head. In another embodiment, the sample and the detector are kept firmly fixed in their relative positions. [0046] Raster scanning of the source is accomplished by driving a dual stepper motor system controlled by software. While the software may be written in Visual Basic, other languages or other object oriented languages can be used. [0047] The system preferably has a resolution of 0.9 degrees in each step and 400 steps per second on a screw drive channel rail with diameter 1.24 cm. [pitch=1 mm, diameter=12 mm]. [0048] The electronics used for signal processing comprises a spectroscopy amplifier, Timing Single Channel Analyzer (TSCA), linear gates, and LVDTS. The spectroscopy amplifier is selected to filter the charge integrated pulse outputted from the detector's preamplifier. The TSCA provides a TTL logic pulses every time a peak amplitude voltage pulse from the spectroscopy amplifier falls within a narrow band of voltages (energy window) that signify a 511 keV (annihilation event) gamma ray energy event. In one embodiment, two linear gates are switched every time a TTL “hi” is supplied from the TSCA so as to produce the position coordinate signals x and y that have pulse heights proportional to the x and y displacements. This allows for efficient management of processing time and memory by providing x and y coordinate information when an annihilation event triggers the TSCA/detector system. When an annihilation event triggers the detection system, recalculation of the S-parameter occurs for the pixel that has received an event, since if there is no event, nothing is contributed towards the S-parameter value of that concerned coordinate. In one embodiment, the instrumentation setup includes linear variable differential transformers attached to the scanning instrument as shown in FIG. 13 , such that for the whole range of movement, they operates with a positive output as required to produce positive x and y pulses for the nuclear ADC. The LVDTs are preferably calibrated in the range, +5 volts with resolution 0.001V. The scanning apparatus shown in FIG. 13 comprises a rigid iron frame structure on which the stepper motors that drive the scanning in the xy plane through screw channel rails are mounted. While the system was discussed using TTL logic, the system can be implemented using CMOS logic, ECL logic, or the like. [0049] The scanning apparatus comprises two stepper motors which are controlled by a computer running the motion control software program. In one embodiment the program is written in Visual Basic. Other programs can be used including Delphi, C++, Java, etc. The motion control program is typically run in the environment of the motor control software that is provided by the manufacturer of the motor. [0050] FIG. 20 depicts the imaging software in flow chart form. FIG. 3 is a depiction of the system software program written in LabVIEW (LabView is a graphical programming language software. In LabVIEW terminology, such a graphical program is called as ‘virtual instrument diagram’) The instrumentation comprises data acquisition, data processing, computations, and real-time image visualization. The software algorithm accesses binary data from three different nuclear ADCs employed for x, y and energy channels and then converts the 14 bit data blocks (as the ADC output is 14 bit binary) into an integer decimal numbers. [0051] In one embodiment, the program is adapted to accommodate the x and y coordinate data in a 32×32, 64×64, 128×128, or 256×256 matrix. The matrix is transformed into coordinate pixels in the graphing plane. By default, the system stores data in a 128×128 matrix. But the user may also choose it to 256×256, 64×64 and 32×32 by adjusting the rotatable knob named “max resolution” on the front panel ( FIG. 4 ). An algorithm in sub-vi form in the imager checks lower pixel images converted from the higher pixel original image (pixels chosen by the user in “Max Resolution”) acquisition which is a state of continuing acquisition ( FIGS. 17 a and 17 b are the VI and front panel of this sub-vi). [0052] The program preferably includes a scaling algorithm using simple digital-offset. By dividing the remaining value with a fixed number, which is determined according to the maximum and minimum x and y channels present in the incoming numbers from the front panel shown in FIG. 4 , so that the input x and y coordinate values range from 0 to the user input resolution value for correct indexing to the corresponding data storage matrix. Included in the program is a provision to monitor the incoming energy value as shown in the front panel, Energy Channel window in FIG. 4 from which the user can select maximum energy value. [0053] The program also monitors the energy spectrum in a xy plot having y axis as the total sum of all energy values stored for a particular x and y index and the subsequent pixels, in Physics term, channel no, in the same row of the matrix. The energy spectrum is plotted giving a very efficient way to monitor the electronic drift during the period of image acquisition or a portion thereof. The program includes a provision for the user to input a numbered which will be deducted, a digital offset, from each of the incoming energy values. This deduction is to keep only 100 channels around the peak channel (the maximum energy value) for processing. This input number is inputted by monitoring the energy spectrum on the front panel as shown in FIG. 4 . [0054] Additionally, a half width value having a decimal value having 3 digits after the decimal point can be entered as shown in the front panel FIG. 4 . The number is selected to preferably keep the “Mean S” value very close to 0.500 (front panel, FIG. 4 ) which is the optimal for S-parameter sensitivity. The peak channel is measured using the energy spectrum graph as displayed on the front panel, as shown in FIG. 4 . This value is determined by an automatic peak finding method involving fitting a 2 nd order polynomial to the top 25% of the spectral height. The user inputs the half width value that is used to compute the S-parameter, and, after a few trials, achieves a value that produces an S-parameter of around 0.500. Once the half width value is fixed, the peak position is checked (by 2 nd order polynomial fitting) in a certain time interval (use optional between 1-10 minutes) to monitor the electronic drift and an automatic feedback loop ensures that the central region is kept locked on to the peak center. [0055] This minimizes computational time as well as the memory occupancy as there is no excessive real-time computational procedure. The S-parameter is computed in real time in optimal system time consumption and the optimal memory occupancy. The S-parameter is computed by taking the sum of all energy events coming in the range of the peak channel+half width and the peak channel—half width to the sum of all energy events coming in the window of 100 channels around the peak channel, i.e., peak channel −50 to peak channel +50. [0056] The optimization of the system is accomplished by keeping control over the image refreshment period (‘Image Refresh’ window, front panel, FIG. 4 ) so that the user can input the refreshment period by inputting an integer number which is taken as milliseconds. Refreshing 10 times in a second is almost like real time refreshment as the human eye cannot detect changes at a much faster rate. In other embodiments, the refresh rate is set automatically. The S-parameter image (S-parameter Image window, FIG. 4 ) is plotted in an intensity plot such that the length and breadth of the sample are plotted in x and y axis respectively and the S-parameter value is taken in the third dimension and such that a color scale corresponds to the S-parameter value. [0057] The real-time visualization of the S-parameter image, the resolution of which depends upon the matrix size (number of pixels) which is assigned for the data storage in order to get the various pixels of the image. Additionally, the real-time visualization of the S-parameter image with the resolution of this image depending upon the step width of the stepper motors employed for the x, y motion with less step width giving better resolution. [0058] In yet another embodiment, the real-time visualization of the S-parameter image where the time required to get a decent image depends upon the rate of annihilation events detected by the detector and then transferred to the imaging software with higher event/data rates providing faster image production. A diagnostic rate-meter tool ( FIG. 4 ) is provided which shows the average rate of incoming annihilation event data in the range of 100 channels around the peak channel. The monitoring of which gives an estimate of the efficiency by which events detected by the detector are being successfully transferred in to the imaging software. [0059] With use of the instrumentation technique, as depicted in FIG. 7 , the system can also take an image using a monoenergetic positron beam (it means a particular energy setting for positrons in case of variable energy beam) substituting the 22 Na source. As shown in FIG. 7 , the instrumentation technique comprises x and y deflection coils coupled to signal generators that provide suitable ramp voltages to the x and y deflection coils. The charged particle beam can be deflected electromagnetically so as to raster the positron beam across a specified area of the sample. [0060] The x and y coil pairs which are wound with 22 gauge wire are shown in FIG. 5 and FIG. 6 on a proper frame in the appropriate shape. It should be noted that shape and dimensions depend upon the beam design structure of the user with the coils being made firm with application of some glue and then being mounted to the beam structure with suitable support. [0061] The xy coils are calculated to meet the current supply capacity to produce the necessary deflection magnetic field strength, a calculation which can easily be done using Ampere's current law or the Biot-Savart's law. The x and y signals which are respectively a uniform triangular wave (frequency=50 Hz, Amplitude=5V) and a saw-tooth ramp voltage (frequency=1 Hz, Amplitude=5V). The x and y signals which are current amplified up to a suitable level as necessary for the deflection magnetic field necessities which can easily be calculated with help of Ampere's current law. [0062] A first embodiment of the disclosed S-parameter imaging system consists of three major sections, namely the 22 Na source scanning apparatus, the pulse processing electronic setup, and the dedicated system software. The imager system is developed using a radio active positron source which is a focused low energy positron beam. The basic imager is described as well as the positron beam application. [0063] The sources and scanning apparatus are shown in FIG 1 . In one embodiment, the source is comprised of a 0.5 mm diameter 5μCi 22 Na encapsulated in 8 μm thick Kapton foil. The source is supported by a thin plastic sheet attached to an aluminum support frame. The aluminum support frame is connected to an X-Y stepper motor drive. The source is suspended 0.5 mm above the wafer surface. Other types of source designs, such as ones involving collimation of positrons by Al or heavier materials that may allow some screening of annihilations coming directly from the source material itself or a source with no backing material and no collimation. Positrons ejected in the direction opposite that of the wafer traveled tens of cm in the air and the fraction of annihilations received from such positrons was thus minimized through the inverse square law. During the scanning motion the distance from the source to the center of the detector varies between 5 and 6 cm causing slight variations of count rate which have no significant effect on the detectors energy resolution. [0064] The source is moved in rectilinear motion (see FIG. 1 ) by stepper motors which operate linear screw drives. The stepper motor drives are controlled by an independent computer. Linear Variable Differential Transformers (LVDTs) are attached to the base of the support frame so as to provide voltages proportional to both x and y motions. [0065] Annihilation photons, predominantly from the wafer, are detected using an HP Ge detector. Preferably, the detector has a 20% efficiency. The data rate into the annihilation line is preferably limited to 1,500 positron annihilation events per second after optimizing the detector to source distance. Components for one embodiment are shown in Table 1 [0066] FIG. 2 depicts a block diagram of one embodiment of the electronic instrumentation. As the positron source rasters across the wafer surface, the x and y LVDTs provide DC voltages proportional to the displacement in these direction. These voltages are converted to pulses of 2 μs is width using two linear gates that are fed from a Timing Single Channel Analyzers (TSCA) output, which in turn is derived from annihilation photons that give energy signals in a narrow window around 511 keV. It should be noted that every energy event within the defined window there is an associated x and y pulse, the amplitude of which gives the position of the source at the time of the event. The annihilation photon energies E γ together with the x and y pulse signals are processed using a 14 bit nuclear ADC, a peak search and hold ADC. Here the use of the TSCA and the Spectroscopy Amplifier (S.Amp) are as per the standard nuclear instrumentation setup. [0067] Using event data triplets (x, y, E γ ) an S-parameter is computed in real time for each pixel region and is used it to refresh a color image display on the screen coordinates. The program is written using LabVIEW 6.1. FIG. 3 shows the virtual instrument (VI) diagram that depicts the block diagram program of the whole software part of the system. This VI consists also of some sub VIs that are available in the library of the LabVIEW software. DIO CONFIG.vi, DIO START.vi and DIO READ.vi are the library subVIs used here for digital input port configuration, timing of data sampling and data reading respectively. FIGS. 14 a & 14 b, 15 a & 15 b and 16 a & 16 b show the detailed virtual instrumentation diagrams and front panels with typical parameter sets respectively for the above said subVIs. Three identical modules are employed to read 14 bit binary data from the x, y & E (energy) channels. From the output of the subVI DIO READ, the 14 bit binary stream is then passed through further processing in order to convert it into numbers as shown in FIG. 3 . The x and y voltages pulses (spanning 0-5V) are digitized into a 8 k number while the E voltage (0-10V) is digitized into a 16 k number. The numbers from these three different ports are scaled, manipulated, processed and finally traced out into the S-parameter image. [0068] After scaling the three primary inputs (x, y, and E), the data is stored in two 2-dimensional arrays. The first is referred to as the C array and counts events that have fallen in the center region (defined by the control “half-width” in FIG. 4 ) of the annihilation peak. The second is the T array which counts all annihilation events irrespective of where in the annihilation peak they fall. Each event is indexed into the appropriate element of the array according to the value of x and y for the event. The final stage is computing the S parameter for each array element. With reference to the FIG. 3 , the computational strategy for real-time determination of S-parameter is preferably optimized in time and memory consumption. The scheme of S-parameter computation is made as practicable as possible by considering the empirical values, unlike the traditional method in which S is calculated in an extremely bulky data handling and computational procedures involving background reduction, peak fitting (i.e., spine or polynomial fitting) in real-time. In practical observation, these extremely heavy computational expenses do not give any noticeably improved sensitivity with regards to minute inference of defect characteristic in image analysis to make them warranted. In contrast, the S-parameter is simply obtained by dividing the sum of events in the central region “C” by the total sum of events “T” coming in the specified 100 channels, for all array elements (S=C/T by definition). This array of S-parameters is stored and forms the S-parameter image. [0069] The imaging software has an embedded important facility that allows variable lateral resolution of the image. There are 4 different resolution levels, namely 32×32, 64×64, 128×128 and 256×256. These are useful in that it takes time for S-parameter information to build up in the image. The accuracy of the S-parameter in each pixel depends on the square root of the number of events for the pixel (or the square root of the amount of accumulation time). For this reason, the user may choose to start the imager with a 32×32 resolution and increase this to 128×128 as time goes on. Indeed sufficiently good images may be achieved, according to user requirement, for example with 64 × 64 resolution. The number of pixels in the plot is a user defined option. FIG. 4 shows the control panel in which the rotatable knob “Max Resolution” serves the purpose of resolution variation. The changing of resolution is accomplished using an algorithm in sub-vi form to check the lower resolution image converted from the higher resolution image (128×128) acquisition which is continually accumulating ( FIGS. 17 a and 17 b are the VI and front panel of this sub-vi). In FIG. 3 , it is seen that x and y incoming values serve the x and y indices in order to accommodate the incoming parameter value in the 2D array mapping. Preferably, the minimum and maximum values of the incoming x and y values should range from about 0 to about 128. To achieve this, the x and y digitized voltage values from the LVDTs undergo both a digital offset and scaling. This may be seen from the front panel ( FIG. 4 ), where the maximum and minimum incoming values of the x and y ports are noted and the difference of the respective max and min values is divided so as to produce natural numbers up to about 128 after being rounded off. There is preferably no scaling for the energy values, but much of the data is discarded since it does not form part of the annihilation line. Thus only those digitized energy values that lie within about ±50 of the annihilation peak maximum or peak channel are used for the S-parameter calculation. The shape of the annihilation line ‘spectrum’ can be viewed from the front panel ( FIG. 4 ), a suitable number being manually entered by the user so as to keep only those 100 channels around the peak value which will give rise to the average S-parameter value approximately 0.500 in view. Also only the positive energy values are being chosen. The user has to enter the value of the ‘half width’ (of the 511 Kev event) in the specified field (6 digit decimal) of the front panel ( FIG. 4 ) so as to keep the average S-parameter around 0.500 (front panel, FIG. 4 ). [0070] Also as part of the major time management scheme, the image refreshing period for the image visualization on the screen is user defined. FIG. 4 shows a user input field, ‘Image Refresh’ whose value serves the time between the successive refreshments, preferably in milliseconds. The spectrum is also refreshed in a time interval of 1-10 minutes (user input in ‘Spectrum refresh’ field of the front panel FIG. 4 ). In fact the quicker spectrum refresh does not provide any noticeable change in its shape. [0071] For monitoring the system performance, there are several monitors on the front panel, FIG. 4 . The ‘rate’ meter is one of them. This shows the average rate of annihilation peak events “T” coming inside the ±50 channel range. It gives an indication of the number of successfully processed annihilation peak events from which the efficiency of the system can be worked out since the annihilation line event rate from the detector can be monitored separately by single channel analyzer (SCA) and a rate meter. In one embodiment, there are also ‘scan back log’ monitor windows on the front panel which shows an increasing trend (by number display) if all data coming to the data acquisition card buffer is not transferred into the imaging software. Preferably, this buffer should be kept constant with a small number for example, 2 digits. This may be achieved by setting the ‘buffer size’, which is another control window in the front panel. The settings of other parameters such as image refresh rate, matrix dimensions, and computational jobs influence this parameter. The spectrum plot, which can refresh about every 10 seconds, also helps in monitoring any electronic drift that occurs during long term accumulation. [0072] FIG. 8A shows photograph of the symbol “e + ” made up of 0.5 mm thick kapton (polyimide) foil pasted on the surface of silicon wafer. The S-parameter image taken by the invented imager with 128×128 pixel resolution is shown in FIG. 8B . [0073] FIG. 9A is the photograph of a monocrystalline Ni sample produced by high pressure torsion. The sample was produced by high pressure torsion. This means that the defect profile should be a radial distribution around the center of the sample. FIG. 9B is the S-parameter image of the sample where the parametric values are prominently distributed radially around the center making clear that that the defect profile is also distributed radially about the center. To draw a clearer inference from this S-parameter image data set, the user may take the S-parameter values along a row of pixels passing through the central region of the image. FIG. 9C is the bar-chart plot of the above mentioned taken along row 55 of FIG. 9B . The height distribution of the bars which stand for the S-parameter values of the corresponding pixels is gradually increasing from centre of the sample towards the periphery. This is a clear inference of the defect profile as was predicted by the sample supplier. The image in FIG. 9B is taken with stepper motor step width of 3.6 degrees in the y-direction which causes the observed vertical “striation”. The step width of the motors could be reduced (to 0.9 degrees minimum) in which case a smoother image of the sample would be formed. [0074] FIG. 18 shows two S-parameter scan images taken for n-type GaAs—Si doped—with carrier concentration of 10 17 cm 2 . FIG. 18A shows a 128×128 pixel resolution plot. There is a good deal of “granulation” in the image. Much of this comes from the poor statistical accuracy available on the S-parameter (stand. dev. ΔS=±0.004)—with only 15,000 events per pixel region. On the other hand in FIG. 18( b ) the spatial resolution is decreased to a 64×64 pixel resolution plot and there is an improvement in image visualization produced through the decreased statistical error on S (ΔS=±0.002). Because of the natural spread of positrons from the source (˜1 mm), it can be argued that this is an optimal resolution for scanning a 5×5 cm region—since the source spread does not permit any finer pixel region division. It is noted that FIG. 18B shows clearly the presence of some “hot” (white) regions that indicate the presence of regions with a higher concentration of defects. There are also some regions of the image where the image is darker than average and these may be interpreted as regions of low defect density. [0075] In order to show more clearly the presence of defects in the wafer the S-parameter data of a single row is plotted in FIG. 18C . This is row 29 of the FIG. 18B image. As may be seen, the peaks and valleys are far in excess of the statistical allowance. Using S-parameter alone it is difficult to tell the defect type being mapped. In n-type, GaAs both negatively charged As and Ga vacancies are known to trap positrons. However the difference between maximum and minimum S-parameters is ˜0.04, which is more than that expected for saturation trapping into monovacancies. In another embodiment of the system, the imager system uses an R-parameter in addition to the S-parameter. [0076] The imager system as described finds easy extension to use with a focused monoenergetic positron beam. Here the term “focused” means that the beam diameter at the target must be 1 mm or less. This focused beam spot essentially replaces the small diameter positron source. The xy scanning by the dual stepper motor system is replaced by a rastering motion of the positron beam, which in turn is achieved by the displacement of the charged particle beam by appropriate application of time-varying (saw-tooth on y and triangular on x) magnetic fields supplied by x and y deflection coils. FIG. 7 is the block diagram depicting this complete plan of the S-parameter imager as used with a positron beam system. FIG. 5 and FIG. 6 give the side and cross-sectional elevations of the xy steering coils. Due to the strong axial magnetic field normally used in low energy positron beams the most appropriate form of deflection is adiabatic deflection in which a small sideways magnetic field causes a small change in the direction of net magnetic field and the positron motion down the beam. The gauge value of the wire and number of turns for one of the pairs of steering coils can easily be calculated by applying Ampere's Law to the coil system of FIG. 6 , i.e., B={[6.928×10 -3 I]/r} Gauss, where B is the sideways deflecting magnetic field, I is the current and r is the radius of the xy tube. In one embodiment, for a beam, in which a deflection field of 1 Gauss is required, each coil winding of 100 turns of gauge-22 wire is used. Each pair of coils has a resistance of about 7Ω which are used in conjunction with current amplifiers that can supply up to 1A. FIG. 10 shows the xy signals. The X coils are being fed uniform triangular waves (Freq=50 Hz, Ampl=5V) from a signal generator. The y coil pairs were fed with ramp voltage (Freq=1 Hz, Amp=5V) from another signal generator. All the parameters of the signals can be varied/controlled as per the beam deflection needs of the user. Also the x and y signals are being fed to the data acquisition card and ANDed with the amplified output of the detector as in FIG. 7 so as to keep track of the position coordinates of each event. [0077] A positron beam is used with the x, y scanning system. The S-parameter image taken with this type of slow positron beam is useful for thin film samples. FIG. 19A and FIG. 19B show the photograph of the symbol ‘C’ (0.4 μm thick aluminum deposited on a copper substrate) and the S-parameter image respectively. The edges of the image are not too sharp and some portions of the image are blurred as the beam spot is 1.5 mm diameter. The image improves as the beam spot is 0.5 mm or less. Additionally, the presence of some fast positron contamination in the beam causes blurred images. The removal of the contamination yields clearer images. A sub-millimeter beam and removing the fast contamination yields better quality images. In one embodiment, a micron size beam spots of mono-energetic positrons is used. If applied in conjunction with such micron-sized beams the imaging system will give an extremely high resolution image of micron sized electronic device structures. Moreover such images could be produced within reasonable operation times with high beam intensity. [0078] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. Accordingly, the spirit and scope of the present invention is to be limited only by the following claims.

Disclosed is a fully automated system capable of producing high quality real-time S-parameter images. It is a useful and versatile tool in Material Science and Solid State Technology for determining the location of subsurface defect types and concentrations on bulk-materials as well as thin-films. The system is also useful in locating top surface metallizations and structures in solid state devices. This imaging system operates by scanning the sample surface with either a small positron source ( 22 Na) or a focused positron beam. The system also possesses another two major parts, namely electronic instrumentation and stand-alone imaging software. In the system, the processing time and use of system resources are constantly monitored and optimized for producing high resolution S-parameter image of the sample in real time with a general purpose personal computer. The system software possesses special features with its embedded specialized algorithms and techniques that provide the user with adequate freedom for analyzing various aspects of the image in order to obtain a clear inference of the defect profile while at the same time keeping automatic track on the instrumentation and hardware settings. The system is useful for semiconductor and metal samples, giving excellent quality images of the subsurface defect profile and has applications for biological samples.

CROSS-REFERENCE TO RELATED APPLICATION This is a divisional application of Ser. No. 07/878,554 abandoned. FIELD OF THE INVENTION This invention relates to a composite structure including a fibrous mat and a plurality of discrete ceramic elements or islands, a method for making such a composite structure, a screen useful in printing the discrete ceramic elements, and procedures to install (adhere, seam seal and field cut) and remove the same. The invention also relates to a composite structure in which a ceramic composition, preferably penetrates only a portion of the fibrous mat. BACKGROUND OF THE INVENTION Most ceramic architectural products are presently made from thick bodies which are fused at high temperatures. They impart wear/stain resistance through their inherent hardness, low porosity and chemical inertness. When properly installed, they exhibit long life and appearance retention. While existing for centuries, no substantial advancements have been made in the processes to either manufacture or install ceramic products. The manufacturing process involves high temperatures and relatively long fusion times; grouting often involves traditional cement or more recently rigid epoxy/cement systems. Substantial thickness has been required due to the brittleness and fragility of the ceramic. These products and their installed weight require special preparation of the substructure on which the ceramic product is installed both for on-grade and above-grade installations. To install current ceramic products, the support structure must be very flat. Removal of these products is tedious and difficult. SUMMARY OF THE INVENTION An object of the present invention is to provide a composite structure which has the appearance retention and wear resistance of ceramic while reducing the overall weight of the structure and permit easy installation without the necessity of preparing a very flat, strong, dimensionally stable substructure. The present inventors have produced product structures that combine the best characteristics of ceramic and resilient products. Through judicious selection of components, a structure has been fabricated that combines relatively thin ceramic elements, a fibrous mat, a non-ceramic composition between and/or below the ceramic elements as appropriate, and flexible, conformable or rigid support substrates. The ceramic elements have a thickness of about 5 to about 100 mils, preferably about 15 to about 75 mils, and more preferably about 20 to about 50 mils. The shape of the ceramic elements includes geometric and random, and may be of differing sizes. However, the maximum dimension of the discrete elements is preferably 11/2 inches, and more preferably less than 1 inch, and most preferably less than one-half inch. Further, the aspect ratio (the length divided by the thickness) should be at least 3. Prior art ceramic elements as thin as one-eighth inch (125 mils) are known. However, thinner elements have proven to be too brittle. By use of the fibrous mat and non-ceramic composition, this disadvantage of the prior art has been overcome. The fibrous mat may be woven or non-woven, but is preferably non-woven. In the preferred embodiment, the fibrous mat should have substantial thickness since the ceramic ink only partially penetrates into the fibrous mat, leaving the portion of the mat opposite the ceramic ink free of ceramic ink. The preferred thickness of the fibrous mat is from about 10 to about 30 mils, mere preferably about 12 to about 20 mils. However, fibrous mats of lesser and greater thicknesses can be used. The substantial thickness of the fibrous mat improves. adhesion of the ceramic elements to the non-ceramic composition and/or substrate. Since the ceramic ink penetrates into the fibrous mat, it adheres well to the mat. It is easier to adhere the ceramic-free fibrous mat to the non-ceramic composition and/or substrate than to directly adhere the ceramic elements to the non-ceramic composition and/or substrate, particularly if the non-ceramic composition and/or substrate is not rigid. The fibers mechanically bond the ceramic and non-ceramic composition. Also, since the ceramic ink does not penetrate to the continuous belt or other support structure during manufacture, the ink will not fuse to the belt and it is not necessary to prevent such fusion. Further, the shape of the ceramic elements is controlled by the fibrous mat. During the fusion step, without the fiber, the ceramic ink would soften, and tend to flow and lose its desired shape. However, the fibrous mat helps the softened droplet retain its shape above the surface of the mat as well as within the mat. In fact by controlling the penetration of the ceramic ink into the fibrous mat so that there is only partial penetration, a composite comprising a continuous layer of ceramic can be formed. The fibrous mat may reduce the brittleness of the ceramic and enhances adhesion of the composite to a non-ceramic composition and/or substrate. The properties of the composite are influenced by the type of material selected for the fibrous mat. Glass scrim is preferred. However, inorganic scrims, stainless steel fabric, organic/inorganic mixed scrims, and totally organic scrims have been used. Technology key to the fabrication of these hybrid ceramic organic structures involves a capability to generate thin ceramic layers and/or ceramic elements of controlled size, shape and pattern, preferably in a fast fire process. Typical fabrication steps include embedding the ceramic elements in a matrix and lamination of the composite to a resilient substrate. A fibrous woven or non-woven carrier is selected based on its capacity to retain thick ceramic deposits in preselected regions via printing or stenciling processes. The fibrous mat may be printed with a ceramic ink using a screen that has "wells" defined beneath the open areas that permit a "thick" deposit of ink, or the ceramic ink may be applied by a rotary screen printing process. The pattern's design is such that the ceramic regimes may form isolated "islands" of relatively small size in relation to the overall dimension of the product. The volatile components are removed, and the entire sheet is processed through a burnout and fusion furnace. The fused sheet is transferred to a layer of a non-ceramic composition to saturate the fibrous mat or web. Then appropriate cure and/or thermal treatment is done to solidify and develop the properties of the non-ceramic composition, which is preferably a polymer grout. If the fibrous mat is saturated from the bottom up (from the surface opposite the ceramic elements), the exposed surface of the ceramic elements do not need to be cleaned of the non-ceramic composition. However, the non-ceramic composition can be applied to the ceramic element side of the fibrous mat. Further, the non-ceramic composition may be applied as a dry powder which fills the voids between the ceramic elements, while the excess powder can be easily removed by brushing or blasts of air. The non-ceramic composition is preferably a polymer composition such as plastisol, urethane, polyester, epoxy, silicone, or phosphate cement. The non-ceramic composition may be a ceramic filler with a polymer binder. The result is a sheet consisting of a polymeric matrix surrounding relatively small regimes of ceramic; hence, ceramic veneer islands. The ceramic veneer island (CVI) sheet is laminated to a suitable substrate using common adhesives. The liquid polymer may be applied directly to the substrate so that it also serves as a bonding agent. The incorporation of ceramic components in the composite structure provides ceramic-like wear performance behavior while the grout system imparts flexibility and/or resilience to the composite. The composite structure is capable of passing the Mandrel Bend Test Method of ASTM D3111, being bent around a six inch mandrel. Preferably the composite structure can be bent around a two inch mandrel, and more preferably a one inch mandrel. Also if the composite were laid on a ledge with one end overhanging the edge, it may droop at least one-half inch over a foot distance. While the above tests measure flexibility which is an important property for ease of installation, it is important that the surface covering which includes the composite structure be able to conform to the subfloor or substructure on which it is laid. Reducing the amount of ceramic material in the composite layer is one way to improve conformability. Ceramics are not flexible or conformable. The thickness of the prior art ceramic makes it difficult to form a surface covering which is conformable and/or flexible. Further, the thinness of the elements permits the construction of a composite which supports the ceramic elements and is conformable and/or flexible. In fact the composite can be laid on the subfloor or substructure without being adhered to a substrate or a surface covering can be formed in which the volume defined by the exposed surface of the ceramic elements to a depth of 1/4 inch comprises no more than 50 percent of the ceramic elements, and preferably no more than 33 percent. To deposit the ceramic elements, present printing technology is modified to deposit thick ceramic compositions. To accomplish the controlled print deposition, the fabrication of print screens with special thick polymer layers is required to print apply the ceramic compositions onto or into the fibrous mats that support the deposited layers during drying and fusion processing. Subsequent lamination of the composite CVI matrix to a substrate which further supports the ceramic elements permits the formation of a tile component with flexibility and conformability of typical resilient tile. This simplifies installation and increases the ease of removal when compared to prior art ceramic tile. Alternatively, the ceramic elements and fibrous mat can be laminated onto substrate which has been covered with a non-ceramic composition such as plastisol or an adhesive. The substrate may be a rigid tile or a conventional tile base. If a rigid substrate is used, a conformable rubber layer may be disposed opposite the composite layer so that the structure can conform to the surface of the support structure on which the surface covering is laid. The surface covering or tile may be formed by printing different colored discrete ceramic elements or the individual elements printed with different colored ceramic slurries or inks to form a desired non-random pattern, which pattern may be repeating. The pattern may be formed by the various colors of the discrete elements or by the location of the elements themselves. Further, the non-ceramic composition or grout which is disposed between the discrete elements may be multi-colored to form a multi-colored pattern. The grout and/or discrete elements may be transparent or translucent. If such discrete elements and grout is disposed over a printed substrate a desired pattern may be obtained. Preferably, a multi-colored plastisol is disposed on a substrate and the discrete elements and fiber mat are laid over the plastisol so that the plastisol penetrates into the fibrous mat from the surface of the mat opposite the ceramic elements. Fast-fire fusion of the ceramic components, visual presentation from ceramic/grout combinations and design-control in the ceramic components are interwoven in this invention along with substrate selection to enhance performance and installation. Typical quarry tile might be fired one to three days and presently known fast fire ceramics require one hour of firing. Because of the thinness of the ceramic elements of the present invention, the composite of ceramic ink and fibrous mat may be fired in about 3 to 12 minutes. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of the emulsion screen of the present invention. FIG. 2 is a schematic representation of the composite layer and substrate. DETAILED DESCRIPTION OF THE INVENTION The print screens used prior to the present invention consist of a mesh material stretched taut over a frame with a thin emulsion attached to selected areas. The emulsion acts to direct deposition of inks through selected areas of the screen mesh as well as form a cell thickness which controls the amount of ink deposited. Ordinary emulsion thicknesses range from 1 to 2 mils up to about 5 mils. In the present invention, modified screens were used to control ceramic slurry or ink deposition thickness. The modified screens consist of a plastic sheet 1 that contains preformed passage ways 2. The plastic sheets are glued to a screen mesh 3. The thickness of the plastic sheet and the image formed by selecting passageway locations control the thickness of the deposited ink and the area over which the ink is deposited, and therefore, the penetration into the fibrous mat. Use of a fibrous mat as the material upon which ink is deposited serves to direct and restrict ink movement during penetration and subsequent drying/fusion steps. The deposited ceramic ink penetrates the fibrous matrix of the mat 4 and is supported as individual elements 5. The fibrous network also plays a role in manufacturing a desirable ceramic element configuration, especially to minimize rupturing or fissuring of the ceramic prior to or during fusion. The composite ceramic veneer island structure includes a grout 6 surrounding the distinct ceramic elements 5. The ceramic elements are about 40 mils thick and are of controlled shape and size. Fabrication procedures involve printing onto a fibrous mat (use of special print screens), handling during fusion and flooding a liquid or powder to grout the fused ceramic elements. The composite may be laminated to a substrate 7. EXAMPLE 1 A non-woven fiberglass scrim, designated AGF, was purchased from the Manville Corporation. The fibrous mat was approximately 15 mils thick with one smooth side suitable for achieving high quality printing. The fibrous mat was lightly attached to a thin aluminum plate with 3M spray adhesive #75. The aluminum plate created a nonporous surface capable of being held down by vacuum. The scrim/aluminum plate assembly was placed onto the bed of a conventional print table and the vacuum turned on. Special screens were fabricated to deposit thin ceramic ink layers. A 31.5 mil thick Acetal sheet purchased from Ain Plastics of Lancaster, Pa., was covered on one side with three layers of 5 mil adhesive film from 3M company. The adhesive film had the release carrier still attached to the outside of the last layer. This adhesive covered Acetal sheet was converted into a stencil with a 14"×14" pattern consisting of 3/8" squares on 7/16" centers by laser cutting. A 25 mesh polyester silk screen fabric was stretched over a nominal 30×40" frame. The laser cut stencil was then bonded to the silk screen fabric through the removal of the release carrier covering and using Epoxy 2216 from the 3M Company around the perimeter. The screen was mounted onto the print station and loaded with ink. The inks were either solvent or water-based systems. The viscosity of a water reducible ceramic ink was adjusted to 40,000 centipoise by the addition of conventional glycol based polymer medium. A conventional rubber squeegee was used to execute a flood stroke followed by a print stroke with a squeegee in a nearly vertical position. The off-contact distance was approximately one quarter of an inch. The ceramic slurry did not completely penetrate the fiberglass scrim. The printed fibrous mat still attached to the aluminum plate was loaded into a conventional convection air oven heated to approximately 200° F. After approximately 15 minutes of drying, the printed fibrous mat was stripped from the aluminum plate and returned to the oven for another hour of drying. The dried printed fibrous mat was placed onto a Cordierite setter approximately 15"×15" by 3/4" thick. The setter and fibrous mat assembly was processed through the Radiant Technology Corporation (RTC) furnace at 5" per minute. The four heating zones, 10", 20", 20" and 10" in length were set to 350° C., 500° C., 650° C. and 775° C., respectively to provide a desirable burnout and ramp up to the fusion temperature. A conventional PVC plastisol was prepared and reduced to a viscosity in the region of 4,000 centipoise. The plastisol was drawn down onto a release surface, specifically a release coated flooring felt with a 40 mil drawn down bar. The fused ceramic fiberglass sheet was slid onto a Teflon coated cookie sheet in a careful manner so as not to disrupt what has become a rather mechanically fragile sheet. The sheet was then lowered into the plastisol by sliding the sheet off one edge of the cookie sheet. Two minutes were allowed to elapse to permit uniform and adequate saturation of the plastisol into the fibrous network around the fused ceramic squares. The entire assembly, fused sheet, plastisol, and release felt was placed into an oven treated to 385° F. for 2 minutes. Upon removal, the assembly was placed onto a flat surface and allowed to cool. The sheet of fused plastisol/ceramic squares was stripped off the release felt and cut to final size. An overall resilient structure with regimes of hard inflexible ceramic was produced. EXAMPLE 2 Sheets as prepared in Example 1 were laminated to a variety of substrates. Among these were limestone filled, plasticized PVC ranging in thickness from 40-125 mils; gypsum board; plywood; and 1/4" aluminum plate. Adhesives used were either a pressure-sensitive one commonly used for the installation of "peel and stick" floor tiles or 3M 2216, a flexible epoxy. The lamination step was unnecessary when a nonrelease flooring felt was used on which to draw down the PVC plastisol. The felt remained as part of the final product upon removal from the plastisol fusion oven. EXAMPLE 3 Multi-colored samples were produced by two methods to generate either through color or surface color decoration of the ceramic islands. Method 1 involved forming a multicolor array of through-color elements by printing different colored islands in selected areas; Method 2 involved over printing of selected elements from Example 1 with different single colors. In Method 1, three full pattern deep-well screens were mounted, and each of the screens was coated with silk screen emulsion in such a way that the cells not to be printed by the color from that particular screen were blocked off. The screens were then used in order with careful registration such that the closed cells of the second and third printing accommodate the ink deposited by the previous printing or printings. Drying was carried out after each color was printed as described in Example 1. The subsequent processing steps were the same as those described in Example 1. In Method 2, the overprint method, a full single through-color pattern was printed with a first screen. Then three additional standard silk screens using 60 mesh fabric, each with an open pattern corresponding to the islands that were to be printed with the desired color were used in turn to overprint the dried ceramic ink deposited with the first screen. A drying step was again executed between each color print as described in Example 1. The subsequent processing steps were the same as those described in Example 1. An attractive four colored image in registration was produced. EXAMPLE 4 The final fused surface characteristics of the ceramic elements were modified by adding 200 mesh alumina at approximately a 30% level to a ceramic overprint ink or sprinkling a dusting of alumina over the top of the just-printed undried sample, and then firing the ink or alumina. Samples with coefficient of frictions ranging from 0.4 to 1.1 were produced in this manner. By applying the alumina to the surface, rather than adding it to the printed ceramic islands, less alumina is used. EXAMPLE 5 The PVC plastisol used in Example 1 was substituted with a variety of liquid polymers such as UV curable urethane (clear), polyester, molding urethane, epoxy and silicone. The procedures of Example 1 were followed and produce satisfactory composites. EXAMPLE 6 Powdered polymers were used to fill the regions between the ceramic elements. When the powdered polymers were applied to the liquid polymer already in place surrounding the ceramic islands and the liquid polymer heat cured such that the powder was not completely melted, a granular effect was produced in the grout. Therefore, powder controlled the topological features, mainly texture, in the region between the discrete ceramic elements. PVC, polyester, urethane, epoxy and nylon powders were used either alone or in combination with sticking aids. These materials can be brought into the product from the face by either masking the ceramic elements or removing the excess from the ceramic elements through blowing or brushing. When used alone, the back surface was free of polymer, leaving the ceramic elements exposed for bonding with a lamination adhesive. Alternatively, a powder layer was formed, and the fused sheet as discussed in Example 1 was laid into the powder. Fusion of each polymer was accomplished in an oven using time and temperature appropriate for each polymer. EXAMPLE 7 The discrete ceramic elements may be of various shapes and sizes. Designs incorporating 3/16" and 3/8" squares, a mixture of various size squares, random irregular shapes, and a combination of squares and rectangles were used. The size and shape of the islands are not limiting. EXAMPLE 8 Samples were made where the non-woven glass fibrous mat used in Example 1 was substituted with woven fabrics, inorganic scrims, and stainless steel fabric. Also used were organic/inorganic mixed scrims, and totally organic fibrous mat (cellulose). Each produced satisfactory composites. EXAMPLE 9 A layer of natural rubber approximately 20 mils thick was placed to the back of the composite samples employing the filled PVC substrate to provide increased conformability. EXAMPLE 10 Rigid tile were produced by using a high modulus epoxy material surrounding the ceramic elements. Alternatively, a sample as prepared in Example 1 was laminated to a conventional tile base with high modulus epoxy. EXAMPLE 11 Ease of installation/removal was achieved by using a conventional pressure sensitive adhesive which was tacky at room temperature or two-faced tape. Samples installed via two-faced tape survived severe trafficking and stair-tread environments. Removal was similar to resilient flooring systems. Epoxy adhesives similar to grout systems are acceptable. EXAMPLE 12 A larger structure was made by seam joining individual CVI composite structures using silicone or epoxy. Rotary screen printing also extended the length and width of the ceramic element array, which when grouted, generated large area CVI composites. EXAMPLE 13 Scrims composed of high temperature fibers were used as the substrate for the ceramic ink. Ceramic slurry 30 to 45 mils thick was printed onto Nextel-fiber fibrous mat and fused at 750° C. as described in Example 1. Break strength was increased to 6,400 PSI for the Nextel scrim/ceramic element composite compared to 2,500 PSI for the composites described in Example 1. EXAMPLE 14 A transparent material was used to grout the ceramic veneer elements to produce 3-D effects and/or permit visualization of the substrate beneath the grout. One sample was made using a transparent PVC plastisol incorporating metallic flakes. Other samples were made with a transparent PVC (fused with heat) and a urethane acrylate (cured with UV radiation) atop a substrate with color or decorative backgrounds. Perception of depth results in the grout regions. EXAMPLE 15 Cementitious grouts were substituted for the polymeric grouts of Examples 1 and 5. EXAMPLE 16 Ceramic elements described in Example 1 were made using stencils without screens. Stencils were made from plastic or metal sheets 30 to 45 mils thick. EXAMPLE 17 Samples were made as in Example 4 and the profile of the fused ceramic elements modified by rolling the partially dried ceramic slurry to level the upper surface of the ceramic islands. In this manner, the slightly concave upper surface of the ceramic islands were flattened, EXAMPLE 18 Samples were made as per Example 1 and the fused ceramic elements laid into a continuous grout. A wide/long CVI composite structure was formed from these smaller CVI element structures. EXAMPLE 19 A CVI sheet was prepared as in Example 1 except that the fused ceramic elements with the fibrous mat was saturated upside down in the PVC plastisol. The perpendicular pull out force was measured for this product and the Example 1 product. The results showed that only a nominal force of 0.1 to 0.2 lbs. was required to extract one ceramic chip from the Example 19 product, whereas an average force of 4.0 lbs. was required to remove a chip from the Example 1 product. Therefore, the presence of a fibrous mat enhanced adhesion of the plastisol to the ceramic elements without chemical bonding.

A print and fusion process is used to fabricate ceramic elements that are subsequently utilized to generate a composite including a fibrous mat and discrete ceramic elements. The composite may include a substrate and a flexible or rigid non-ceramic composition between the discrete ceramic elements and/or the substrate. A ceramic ink preferably partially penetrates the fibrous mat to form the discrete elements or a continuous layer.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from U.S. provisional patent application No. 60/314,600, filed Aug. 24, 2001, and from U.S. patent application Ser. No. 09/441,805, filed Nov. 17, 1999, which claims priority from U.S. provisional patent application No. 60/108,751, filed Nov. 17, 1998, now abandoned, all of which are incorporated herein by reference. STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT Not applicable. BACKGROUND OF THE INVENTION The present invention is directed generally to the transmission of signals in optical communications systems. More particularly, the invention relates to systems, devices, and methods for producing upconverted modulated optical signals. The development of digital technology provided the ability to store and process vast amounts of information. While this development greatly increased information processing capabilities, it was recognized that in order to make effective use of information resources it was necessary to interconnect and allow communication between information resources. Efficient access to information resources requires the continued development of information transmission systems to facilitate the sharing of information between resources. One effort to achieve higher transmission capacities has focused on the development of optical transmission systems. Optical transmission systems can provide high capacity, low cost, low error rate transmission of information over long distances. The transmission of information over optical systems is typically performed by imparting the information in some manner onto an optical carrier by varying characteristics of the optical carrier. In most optical transmission systems, the information is imparted by using an information data stream to either directly or externally modulate an optical carrier so that the information is imparted at the carrier frequency or on one or more sidebands, with the later technique sometimes called upconversion or sub-carrier modulation (“SCM”). SCM techniques, such as those described in U.S. Pat. Nos. 4,989,200, 5,432,632, and 5,596,436, generally produce a modulated optical signal in the form of two mirror image sidebands at wavelengths symmetrically disposed around the carrier wavelength. Generally, only one of the mirror images is required to carry the signal and the other image is a source of signal noise that also consumes wavelength bandwidth that would normally be available to carry information. Similarly, the carrier wavelength, which does not carry information in an SCM system, can be a source of noise that interferes with the subcarrier signal. Modified SCM techniques have been developed to eliminate one of the mirror images and the carrier wavelength. However, “traditional” SCM techniques do not work well at high bit rates (e.g., greater than 2.5 gigabits per second). For example, mixer linearity, frequency flatness, frequency bandwidth, and group delay tend to be problematic. It is also difficult to keep power levels balanced and well controlled. Such problems and difficulties can result in significant performance degradation and/or increased cost. Modified SCM techniques have also been disclosed to utilize Manchester encoding in place of electrical carriers, such as described in U.S. Pat. Nos. 5,101,450 and 5,301,058. Initially, single wavelength carriers were spatially separated by placing each carrier on a different fiber to provide space division multiplexing (“SDM”) of the information in optical systems. As the demand for capacity grew, increasing numbers of information data streams were spaced in time, or time division multiplexed (“TDM”), on the single wavelength carrier in the SDM system as a means to better use the available bandwidth. The continued growth in demand has spawned the use of multiple wavelength carriers on a single fiber using wavelength division multiplexing (“WDM”). In WDM systems, further increases in transmission capacity can be achieved not only by increasing the transmission rate of the information on each wavelength, but also by increasing the number of wavelengths, or channel count, in the system. However, conventional systems already have the capacity to transmit hundreds of channels on a single fiber, and that number will continue to increase. As such, the cost of transmitters, receivers, and other devices can constitute a large portion of a system's cost. Therefore, the size and cost of systems will increase significantly as the number of WDM channels increase. Accordingly, there is a need to reduce the cost and size of devices in optical systems while at the same time maintaining or increasing system performance. BRIEF SUMMARY OF THE INVENTION The systems, devices, and methods of the present invention address the above-stated need for lower cost, higher capacity, longer distance optical communications systems, devices, and methods. The present invention is directed to improved systems, devices, and methods for producing sub-carrier modulated optical signals. The present invention can be employed, for example, in multi-dimensional optical networks, point to point optical networks, or other devices or systems which can benefit from the improved performance afforded by the present invention. One embodiment of the present invention is a transmitter including an optical carrier source, an electrical to optical converter, a parser, and first and second Manchester encoders. The electrical to optical converter has an optical input connected to the optical carrier source, an optical output, and first and second electrical data inputs. The parser has a data input and first and second data outputs. The first Manchester encoder has a data input connected to the first data output of the parser and an encoded data output connected to the first electrical input of the electrical to optical converter. The second Manchester encoder has a data input connected to the second data output of the parser and an encoded data output connected to the second electrical input of the electrical to optical converter. Another embodiment of the present invention includes two or more optical carrier sources, and two or more corresponding electrical to optical converters. In some embodiments, the optical carrier sources produce optical carriers with the same optical wavelength, and in other embodiments the optical carrier sources produce optical carriers having different wavelengths. Other embodiments of the present invention utilize other variations and combinations of devices, such as forward error correction encoders, differential encoders, filters, interfaces, and multiplexers. In other embodiments, the data signal is separated into two or more lower bit rate signals for at least a portion of the transmitter. In other embodiments, the parser produces more than two parsed signals. Those and other embodiments of the present invention, as well as receivers, systems, and methods according to the present invention, will be described in the following detailed description. The present invention addresses the needs described above in the description of the background of the invention by providing improved systems, devices, and methods. These advantages and others will become apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: FIGS. 1 and 2 show examples optical communications systems; FIG. 3 shows an embodiment of a transmitter that can be used in the optical communications system; FIG. 4 shows timing diagrams illustrating one example of Manchester encoding; FIG. 5 shows one example of a frequency spectrum for a Manchester encoded signal; FIG. 6 shows one example of a frequency spectrum for an upconverted optical signal generated from the Manchester encoded signal of FIG. 5 ; FIG. 7 shows another embodiment of the transmitter including a filter; FIG. 8 shows one example of a frequency spectrum for a filtered Manchester encoded signal; FIG. 9 shows one example of a frequency spectrum for an upconverted optical signal generated from the Manchester encoded signal of FIG. 8 ; FIGS. 10 and 11 show additional embodiments of the transmitter; FIGS. 12 and 13 show other examples of frequency spectrums for upconverted optical signals FIGS. 14 and 15 show other embodiments of the transmitter; FIG. 16 shows a circuit schematic of one embodiment of the parser, Manchester encoders, and differential encoders; FIG. 17 shows another embodiment of the filter portion of the transmitter; FIG. 18 shows one embodiment of the transmitter interface; FIGS. 19-22 shows several embodiments of a receiver; FIG. 23 shows one embodiment of the receiver interface; and FIGS. 24 and 25 show several embodiments of filters which may be used with the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows an optical communications system 10 which includes optical paths 12 connecting network elements 14 . Advantages of the present invention can be realized with many system 10 configurations and architectures, such as an all optical network, one or more point to point links, one or more rings, a mesh, other architectures, or combinations of architectures. The system 10 illustrated in FIG. 1 is a multi-dimensional network, which can be implemented, for example, as an all optical mesh network, as a collection of point to point links, or as a combination of architectures. The system 10 can employ various transmission schemes, such as space, time, code, frequency, phase, polarization, and/or wavelength division multiplexing, and other types and combinations of multiplexing schemes. The system 10 can also include more or less features than those illustrated herein, such as by including a network management system (“NMS”) 16 and changing the number, location, content, configuration, and connection of network elements 14 . The optical paths 12 can include guided and unguided paths or waveguides, such as one or more optical fibers, ribbon fibers, and free space devices, and can interconnect the network elements 14 establishing links 18 and providing optical communication paths through the system 10 . The paths 12 can carry one or more uni- or bi-directionally propagating optical signal channels or wavelengths. The optical signal channels can be treated individually or as a single group, or they can be organized into two or more wavebands or spectral groups, each containing one or more optical signal channel. The network elements 14 can include one or more signal processing devices including one or more of various optical and/or electrical components. The network elements 14 can perform network functions or processes, such as switching, routing, amplifying, multiplexing, combining, demultiplexing, distributing, or otherwise processing optical signals. For example, network elements 14 can include one or more transmitters 20 , receivers 22 , switches 24 , add/drop multiplexers 26 , interfacial devices 28 , amplifiers 30 , multiplexers/combiners 34 , and demultiplexers/distributors 36 , as well as filters, dispersion compensating and shifting devices, monitors, couplers, splitters, and other devices. One embodiment of one network element 14 is illustrated in FIG. 1 , although many other variations and embodiments of network elements 14 are contemplated. Additional examples of network elements 14 are described in U.S. patent application Ser. Nos. 09/817,478, filed Mar. 26, 2001, and 09/253,819, filed Feb. 19, 1999, both of which are incorporated herein by reference. The optical transmitters 20 and receivers 22 are configured respectively to transmit and receive optical signals including one or more information carrying optical signal wavelengths, or channels, via the optical paths 12 . The transmitters 20 include an optical carrier source that provides an optical carrier and can utilize, for example, coherent or incoherent sources, and narrow band or broad band sources, such as sliced spectrum sources, fiber lasers, semiconductor lasers, light emitting diodes, and other optical sources. The transmitters 20 often include a narrow bandwidth laser as the optical carrier source. The optical transmitter 20 can impart information to the optical carrier by directly modulating the optical carrier source or by externally modulating the optical carrier. Alternatively, the information can be upconverted onto an optical wavelength to produce the optical signal, such as by utilizing Manchester encoding as described hereinbelow. Examples of optical transmitters 20 are described in U.S. Pat. No. 6,118,566, issued Sep. 12, 2000, which is incorporated herein by reference. Similarly, the optical receiver 22 can include various detection techniques, such as coherent detection, optical filtering, and direct detection. Tunable transmitters 20 and receivers 22 can be used to provide flexibility in the selection of wavelengths used in the system 10 . The switches 24 can take many forms and can have different levels of “granularity”. “Granularity” refers to the resolution or precision with which the switching is performed. For example, WDM switches 24 can switch groups of wavelengths, individual wavelengths, or portions of wavelengths. Before being switched, the signals can be demultiplexed into the appropriate level of granularity, and after being switched the signals can be multiplexed into the desired format, using the same or different modulation schemes, wavelengths, or other characteristics. Switches 24 can have electrical, optical, or electrical/optical switch “fabrics”. The switch “fabric” describes the domain and/or manner in which the signal switching occurs. Switches 24 having an electrical fabric convert incoming optical signals into electrical signals, the electrical signals are switched with electronic equipment, and the switched electrical signals are converted back into optical signals. Such switching is often referred to as “O-E-O” (“optical-electrical-optical”) switching. In contrast, switches 24 having an optical switch fabric perform the switching with the signals in the optical domain. However, switches 24 having an optical switch fabric can still perform O-E-O conversions, such as when demultiplexing or multiplexing optical signals, or in other related interface devices or operations. There are many optical switch fabrics, some of which use micro-electromechanical systems (“MEMS”), such as small, electrically-controlled mirrors, to selectively reflect an incoming optical signal to a desired output. Other optical switch fabrics use a variable index of refraction device to controllably change the index of refraction of an optical signal path, such as by forming a gas pocket in an optically transparent liquid medium, in order to change the direction of the optical signal. Yet another example of an optical switch fabric is the use of an optical path in which the optical gain and/or loss can be controlled so that an optical signal can be either passed or blocked. Some examples of switches 24 having an optical fabric are described in U.S. patent application Ser. No. 09/119,562, filed Jul. 21, 1998, and No. 60/150,218, filed Aug. 23, 1999, and PCT Patent Application PCT/US00/23051, filed Aug. 23, 2000, all of which are incorporated herein by reference. Switches 24 can be grouped into two categories: interfacial switches and integrated switches. Interfacial switches 24 , sometimes referred to as “dedicated” switches, perform one or more O-E-O conversions of the signals. The O-E-O conversions can be either in the switch 24 itself or in a related component, such as a multiplexer 34 or demultiplexer 36 . Interfacial switches 24 are located within or at the periphery of networks 10 and point to point links 18 , such as between two or more point to point links 18 , between two or more networks 10 , or between a network 10 and a point to point link 18 . Interfacial switches 24 optically separate the links 18 and/or networks 10 because optical signals are converted into electrical form before being passed to the next optical link 18 or network 10 . Interfacial switches 24 are a type of interfacial device 28 , which is discussed in more detail hereinbelow. In contrast, integrated switches 24 are optically integrated into the network 10 and allow optical signals to continue through the network 10 , via the integrated switch 24 , without an O-E-O conversion. Integrated switches 24 are sometimes called “all-optical switches”, “O-O ” switches, or “O-O-O” switches. A switch 24 can have both an integrated switch 24 portion and a interfacial switch 24 portion, such that some signals are switched without an O-E-O conversion, while other signals are subjected to an O-E-O conversion. Add/drop multiplexers 26 and other devices can function in a manner analogous to integrated switches 24 so that, in general, only optical signals which are being “dropped” from the network 10 are converted into electronic form. The remaining signals, which are continuing through the network 10 , remain in the optical domain. As a result, optical signals in an all-optical system 10 (e.g., systems 10 having integrated switches 24 and integrated add/drop multiplexers 26 ) are not converted into electrical form until they reach their destination, or until the signals degrade to the point they need to be regenerated before further transmission. Of course, add/drop multiplexers 26 can also be interfacial devices 28 which subject signals to an O-E-O conversion. Interfacial devices 28 optically separate and act as interfaces to and between optical networks 10 and/or point to point links 18 . Interfacial devices 28 perform at least one optical to electrical (“O-E”) or electrical to optical (“E-O”) conversion before passing signals into or out of the link 18 or network 10 . Interfacial device 28 can be located within or at the periphery of networks 10 , such as between two or more networks 10 , between two or more point to point links 18 , and between networks 10 and point to point links 18 . Interfacial devices 28 include, for example, cross-connect switches, IP routers, ATM switches, etc., and can have electrical, optical, or a combination of switch fabrics. Interfacial devices 28 can provide interface flexibility and can be configured to receive, convert, and provide information in one or more various protocols, encoding schemes, and bit rates to the transmitters 20 , receivers 22 , and other devices. The interfacial devices 28 also can be used to provide other functions, such as protection switching. The optical amplifiers 30 can be used to provide signal gain and can be deployed proximate to other optical components, such as in network elements 14 , as well as along the optical communications paths 12 . The optical amplifiers 30 can include concentrated/lumped amplification and/or distributed amplification, and can include one or more stages. The optical amplifier can include doped (e.g. erbium, neodymium, praseodymium, ytterbium, other rare earth elements, and mixtures thereof) and Raman fiber amplifiers, which can be locally or remotely pumped with optical energy. The optical amplifiers 30 can also include other types of amplifiers 30 , such as semiconductor amplifiers. Optical combiners 34 can be used to combine the multiple signal channels into WDM optical signals for the transmitters 20 . Likewise, optical distributors 36 can be provided to distribute the optical signal to the receivers 22 . The optical combiners 34 and distributors 36 can include various multi-port devices, such as wavelength selective and non-selective (“passive”) devices, fiber and free space devices, and polarization sensitive devices. Other examples of multi-port devices include circulators, passive, WDM, and polarization couplers/splitters, dichroic devices, prisms, diffraction gratings, arrayed waveguides, etc. The multi-port devices can be used alone or in various combinations with various tunable or fixed wavelength transmissive or reflective, narrow or broad band filters, such as Bragg gratings, Fabry-Perot and dichroic filters, etc. in the optical combiners 34 and distributors 36 . Furthermore, the combiners 34 and distributors 36 can include one or more stages incorporating various multi-port device and filter combinations to multiplex, demultiplex, and/or broadcast signal wavelengths λ i in the optical systems 10 . The NMS 16 can manage, configure, and control network elements 14 and can include multiple management layers that can be directly and indirectly connected to the network elements 14 . The NMS 16 can be directly connected to some network elements 14 via a data communication network (shown in broken lines) and indirectly connected to other network elements 14 via a directly connected network element and the optical system 10 . The data communication network can, for example, be a dedicated network, a shared network, or a combination thereof. A data communications network utilizing a shared network can include, for example, dial-up connections to the network elements 14 through a public telephone system. Examples of an NMS 16 are described in U.S. patent application Ser. No. 60/177,625, filed Jan. 24, 2000, and PCT Patent Application PCT/US01/02320, filed Jan. 24, 2001, both of which are incorporated herein by reference. FIG. 2 shows another embodiment of the system 10 including a link 18 of four network elements 14 . That system 10 can, for example, be all or part of a point to point system 10 , or it may be part of a multi-dimensional, mesh, or other system 10 . One or more of the network elements 14 can be connected directly to the network management system 16 (not shown). If the system 10 is part of a larger system, then as few as none of the network elements 14 can be connected to the network management system 16 and all of the network elements 14 can still be indirectly connected to the NMS 16 via another network element in the larger system 10 . FIG. 3 shows a transmitter 20 including an interface 50 , a Manchester encoder 52 , an optical carrier source 54 , and an E/O converter 56 having a data input 58 . The transmitter 20 can also include components other than those illustrated herein, such as amplifiers, phase shifters, isolators, filters, signal distorters, protocol processors, and other electrical, optical, and electro-optical components. The transmitter 20 can upconvert one or more data signals onto one or more sidebands of the optical carrier λ o , without requiring the data signals to be modulated onto an electrical carrier source. The upconverted optical signal Λo of the present invention does not require a Manchester decoder at the receiver 22 . Rather, the sideband signal can be received in a manner analogous to other upconverted data signals. The interface 50 provides an interface for data signals to be transmitted and can provide a connection to other systems, networks, or links. The interface 50 can be a simple connector or it can be a more sophisticated device, such as one which performs SONET section monitoring and termination functions or other functions, such as transforming the format of the signals entering the system 10 (e.g., an optical to electrical converter or changing a signal from RZ to NRZ format), transforming a single stream of data into plural lower bit rate streams, etc. The interface 50 can be, for example, the receiver end of an optical short reach interface which receives and converts a high bit rate optical signal into two or more lower bit rate electrical signals. The conversion of a single, high bit rate signal into two or more lower bit rate signals is advantageous, for example, when a high bit rate signal can be processed more efficiently in several lower bit rate streams. The Manchester encoder 52 encodes incoming data signals with a Manchester encoding scheme. The encoder 52 can be implemented, for example, as an integrated circuit, such as an application specific integrated circuit, a general purpose integrated circuit, a field programmable gate array, or other integrated circuits. The Manchester encoding scheme typically encodes each bit of data as a two part bit code, with the first part of the bit code being the complement of the data, and the second part being the actual data. Other variations of Manchester encoding, such as where the second part of the bit code is the complement of the data, can also be used with the present invention. Furthermore, although the present invention will be described in terms of Manchester encoding, the present invention is applicable to other encoding schemes, including the modulation of data onto an electrical carrier, which reduce or transform the DC component of data signals and, thereby, provide for signal upconversion in accordance with the present invention. In some embodiments, the transmitter 20 can upconvert data onto one or more sidebands, or it can transmit data at the optical carrier wavelength λ o . For example, the Manchester encoder 52 can be activated for upconversion and deactivated, so that data signals pass through unencoded, for transmission at the optical carrier wavelength λ o . In other embodiments, the transmitter 20 can include a bypass circuit around the Manchester encoder 52 for transmission at the optical carrier wavelength λ o . The optical carrier source 54 provides an optical carrier having a center carrier wavelength λ o , such as a continuous wave optical carrier, to the E/O converter 56 . The optical carrier source 54 can include control circuits (not shown), such as drive and thermal control circuits, to control the operation of the optical carrier source 54 . The E/O converter 56 receives the optical carrier λ o from the optical carrier source 54 and receives electrical data signals at data input 58 . The E/O converter 56 converts the electrical data signals into optical data signals Λ o . The E/O converter 56 can provide the data on one or more sidebands of the optical carrier λ 0 , which is sometimes referred to as “upconversion” or “subcarrier modulation”. The E/O converter 56 can include, for example, one or more Mach-Zehnder interferometers, other interferometers, or other E/O converters. FIG. 4 shows an example of Manchester encoded data, along with corresponding NRZ data and a clock signal. In that example the Manchester encoded data corresponds with data in NRZ format, although many forms of data can be Manchester encoded, including data in RZ format. In this example, the Manchester encoded data includes a two part bit code, with the first part of the bit code being the complement of the data, the second part being the actual data, and with a transition between the two parts. Other variations of Manchester encoding can also be used with the present invention. One form of Manchester encoding is specified in IEEE Standard 802.3. Other forms and variations of Manchester encoding also exist and are applicable to the present invention. FIG. 5 shows an example of Manchester encoded data in the frequency spectrum. Manchester encoded data typically has an asymmetrical frequency spectrum about data rate frequency f d . Furthermore, the data rate frequency f d of the data signal affects the frequency spectrum of the Manchester encoded data, so that the greater the data rate f d , the greater the spread of the frequency spectrum of the Manchester encoded signal. Because each bit of a Manchester encoded signal has a transition between states, Manchester encoded data has a frequency component equal to the bit rate. As a result, the electrical data signals are upconverted onto one or more sidebands of the optical carrier λ o at the electrical to optical converter 56 . Furthermore, the frequency spectrum of the Manchester encoded signal will affect the shape and offset of the sidebands. FIG. 6 shows a signal profile of the optical data signal Λ o when the Manchester encoded data signal of FIG. 5 is input to the E/O converter 56 . In that example, the Manchester encoded data signal is upconverted onto a single sideband of the optical carrier λ o and the optical carrier λ o is suppressed. The present invention can also be used with other upconversion formats. For example, the carrier does not have to be suppressed, and the Manchester encoded data signals can be upconverted in other formats, such as double sideband signals. FIG. 7 shows another embodiment of the transmitter 20 including a filter 60 for the Manchester encoded signal spectrum. The filtered Manchester encoded signal allows for better performance by, for example, providing a filtered Manchester encoded signal having a frequency spectrum which is more symmetrical about the data rate frequency f d and more narrow, thereby requiring less bandwidth to transmit the same information. In some embodiments, the filter 60 may be omitted, such as when using a narrow band E/O converter 56 (e.g., a resonantly-enhanced modulator). The filter 60 may also be used to narrow the frequency spectrum in conjunction with other devices, such as differential encoders 69 described hereinbelow, to facilitate other functions, such as to facilitate duobinary encoding. FIG. 8 shows a frequency spectrum for one example of the filtered Manchester encoded signal, with the unfiltered signal shown as a broken line. FIG. 9 shows a signal profile of the optical data signal Λ o when the Manchester encoded data signal of FIG. 8 is input to the E/O converter 56 . In that example, the sideband signal is more compact and, therefore, uses less bandwidth than the sideband generated from unfiltered Manchester encoded signals, thereby allowing for increased system performance. FIG. 10 shows another embodiment of the transmitter 20 which includes a forward error correction (“FEC”) encoder 62 . The FEC encoder 62 can utilize, for example, a G.975 compliant (255,239) Reed-Solomon code, or another FEC code or coding scheme. The FEC encoder 62 will add non-information carrying and/or redundant data, sometimes referred to as “overhead”, to the signal, thereby changing the bit rate and frequency spectrum of the Manchester encoded signal. A change in the bit rate and frequency spectrum of the Manchester encoded signals can change the location and frequency spectrum of the sidebands relative to the optical carrier λ o . The amount of overhead added by the FEC encoder 62 will vary depending on the amount of FEC encoding performed on the data signals. In other embodiments, the information can be parsed (or inverse multiplexed) into two or more streams that can be transmitted to the destination. The resulting parsed streams may be lower bit rate streams which can allow for signals to be transmitted over a greater distance without regeneration or with fewer regeneration sites. Alternatively, the signal may be parsed into two or more bit rate streams which are not lower bit rate signals than the received signal, such as when a signal is parsed into identical copies for redundant transport, or when additional information is added to the parsed signals so that the resultant bit rate is not lower. Parsing or inverse multiplexing, when applied to SONET signals constructed from lower bit rate SONET signals can be merely a demultiplexing of the high bit rate SONET signal into its low bit rate SONET components. The information being transmitted can be recovered from the lower bit rate signals without inverse demultiplexing the lower bit rate signals into the higher bit rate signal. Whereas, inverse multiplexing of concatenated SONET signals fragments the information, requiring the IM signals be inverse demultiplexed to recover the information. While inverse multiplexing is known in the art, there are difficulties with the schemes, particularly in concatenated data streams. A primary difficulty with inverse multiplexing is that the inverse multiplexed data streams will travel from the origin through the optical systems at different rates causing a misalignment, or skew, of the data at the destination. In parallel optical systems, transmission path lengths for the inverse multiplexed signals are equalized as much as possible to lessen the skew between the signals. In WDM systems, while a common fiber is used, chromatic dispersion of the different wavelengths carrying the inverse multiplexed signals, as well as the mux/demux structure of the WDM system can greatly increase the skew. Various methods can be applied to compensate for the skewing of inverse multiplexed signals. For example, U.S. Pat. No. 5,461,622 suggests using both framing and pointer bytes in SONET overhead to deskew the information. Unfortunately, the amount of skew introduced by the system 10 can vary with the system conditions, which can degrade the system performance, particularly in WDM systems. For example, variations in the wavelengths one or more of the transmitters used to transmit the inverse multiplexed signals can caused variations in the amount of skew in the system 10 . In one aspect of the present invention, the transmitters 20 are configured to upconvert two or more inverse multiplexed signals onto different subcarriers of a single optical carrier wavelength provide by a transmitter 20 . The frequency spacing between subcarrier can be substantially less than between adjacent carriers, so as to greatly decrease the dispersion and resultant skew between the inverse multiplexed signals during transmission in WDM systems. In addition, transmitting the inverse multiplexed signals on subcarriers of a common optical carrier essentially eliminates path length differences introduced by WDM multiplexing schemes. Various subcarrier modulation techniques can be employed to upconvert the inverse multiplexed data streams onto the subcarriers. Single sideband, suppressed carrier upconversion techniques can be used to minimize unwanted mirror image subcarrier and carrier wavelengths being transmitted along with the signal wavelengths. Although conventional double sideband, non-suppressed carrier, subcarrier modulation techniques also can be employed. An example of single sideband, suppressed carrier transmitters suitable for use in the present invention are described in commonly assigned copending U.S. application Ser. No. 09/185,820 filed Nov. 4, 1998, the disclosure of which is incorporated herein by reference. The number of inverse multiplexed signals may or may not coincide with the number of subcarriers being upconverted on a single transmitter. When the number of inverse multiplexed signals does not correspond to the number of subcarriers, the inverse multiplexed signals can be upconverted onto two or more transmitters transmitting information that provide adjacent signal wavelengths in a wavelength channel plan. For example, placing two subcarriers on each of two adjacent carriers can decrease the dispersion and resultant skew between the inverse multiplexed signals by a factor of 2-3 times compared to the skew using four carriers. Inverse multiplexing can be used to separate and transmit concatenated and unconcatentated higher bit rate information streams, e.g., OC-768c & OC-768, OC-192c & OC-192, etc. The inverse multiplexed signals can be framed with appropriate transmission overhead at lower bit rates to allow the inverse multiplexed signals to be deskewed and recombined into the higher bit rate signal at the end of the link. The deskewing can be performed using the framing A 1 and A 2 bytes in the transmission overhead or additional bytes, as previously discussed. In various embodiments, the receivers are configured to coherently detect two or more of the subcarriers carrying the inverse multiplexed signals. Coherent detection of the subcarriers eliminates much of the path variability introduced by demultiplexing and direct detection of the inverse multiplexed signals. Coherent detection can be performed using a remnant of the carrier wavelength with or without a local oscillator providing a heterodyne signal. In various embodiments, the local oscillator can be locked using the remnant carrier wavelength to ensure proper tracking of any drift in the carriers and subcarriers during operation. In fact, a tunable local oscillator can provide additional flexibility in configuring receivers 22 in the system 10 . In other embodiments, detection techniques other than coherent detection, such as direct detection, may be used. FIG. 11 shows another embodiment of the transmitter 20 including a parser 64 and a coupler 66 . In that embodiment the parser 64 separates the data signal into two signals which are coupled before entering the E/O converter 56 such that the signals are upconverted onto separate sidebands of the optical carrier λ o . The transmitter 20 can be used, for example, to transmit a high bit rate signal as two or more lower bit rate signals. Such a transmitter 20 is advantageous, for example, if a high bit rate signal is provided to a transmitter 20 but desired system performance, such as transmission distance, OSNR, etc., is not practical or cost effective with the higher bit rate signal. In that situation, the higher bit rate signal can be separated into two or more lower bit rate signals which can be recombined or assembled at the receiver 22 . The parser 64 in the illustrated embodiment separates the data signal into two data signals. In other embodiments of the transmitter 20 , the parser 64 can separate the data signal into more than two data signals. The parser 64 can also utilize other parsing schemes, such as separating the data signal into two or more data signals having the same or different bit rates. The parser 64 can also separate the data signal at every bit, at every byte, at every several bits or bytes, or in other intervals, whether uniform or non-uniform. For example, the number of bits or bytes can vary with time or with some other function, such as a parameter of the data signal. Furthermore, the parser 64 can utilize redundancy in the data streams, such that some data is provided on more than one data stream, or no redundancy at all can be used. The parser 64 can include those and other variations and combinations of parsing schemes. In one example, the parser 64 separates a data stream onto two, lower bit rate data streams, and parses the data stream at each bit, sending one bit on one data stream, sending the next bit on the other data stream, and then repeating. The coupler 66 in the illustrated embodiment is a two-by-two, ninety degree electrical coupler, such that the first output produces a signal similar to the signal at the second input plus a ninety degree phase shifted form of the signal at the first input, and the second output produces a signal similar to the signal at the first input plus a ninety degree phase shifted form of the signal at the second input. The coupler 66 couples and phase shifts the parsed data signals so that, for example, when each output of the coupler 66 is used to modulate an arm of a double parallel Mach-Zehnder interferometer or a similar device, each of the parsed signals will be upconverted onto a separate optical sideband, as shown in FIG. 12 . Other variations of the electrical coupler 66 are also possible. For example, the coupler 66 can have different numbers of inputs and outputs, can induce different phase shifts, and can equally or unequally split and couple the signals to produce different kinds of optical signals. Also in that embodiment, the interface 50 demultiplexes or “deserializes” the incoming data signal into several lower bit rate signals, which are provided by the interface 50 in parallel. Such deserializing of a signal can facilitate processing the signal, such as for FEC encoding and parsing. For example, in some circumstances it is more practical to perform parallel processing on two or more lower bit rate signals than it is to perform the same operation on a single, high bit rate signal. Some, none, or all of the data processing in the transmitter 20 can be performed with several parallel, lower bit rate signals. Multiplexers 68 , sometimes referred to as “serializers”, are also included in that embodiment to combine parallel data signals into a higher bit rate serial data signals. FIG. 12 shows a signal profile of the optical data signal Λ o when the parsed and coupled data signals of FIG. 11 are input to the E/O converter 56 . In that embodiment, one of the data signals is upconverted to a data signal at a longer wavelength than the optical carrier λ o , the other sideband is upconverted to a sideband at a shorter wavelength than the optical carrier λ o , and the optical carrier λ o is suppressed. FIG. 13 shows another signal profile of the optical data signal Λ o . That signal profile can be produced by an embodiment of the transmitter 20 in which the parser 64 separates the data signal into signals having different bit rates and, therefore, different frequencies. As a result, the different data signals will be offset differently from the optical carrier λ o . Typically, the lower bit rate signal will also have more narrow frequency and wavelength spectrums. In other embodiments, the optical data signals can be on opposite sides of the optical carrier λ o , and in other embodiments there can be more than two parsed data signals having more than two different bit rates. FIG. 14 shows another embodiment of the transmitter 20 including differential encoders 69 . The parser 64 , differential encoders 69 , and Manchester encoders 52 can be implemented, for example, as one or more field programmable gate arrays, application specific integrated circuits, general purpose integrated circuits, or other integrated circuits. Furthermore, the differential encoders 69 , as well as other devices, may be implemented in other embodiments of the invention, such as embodiments without the parser 64 . Furthermore, the differential encoder may be replaced with other encoders, such as duobinary encoders. FIG. 15 shows another embodiment of the transmitter 20 in which the parser 64 is used and the coupler 66 is eliminated. In that embodiment, an optical carrier source 54 and an E/O converter 56 are provided for each parsed signal. For example, both parsed data signals can be provided at the same bit rate, but optical carriers λ o having different wavelengths can be used so that the data signals are upconverted onto different frequencies. In other embodiments, the optical carrier sources 54 can produce optical carriers λ o having the same wavelength and, for example, one parsed data signal can be upconverted onto a sideband having a longer wavelength than the optical carrier λ o , and the other parsed data signal can be upconverted onto a sideband having a shorter wavelength than the optical carrier λ o . In other embodiments, the parser 64 can separate the data signal into more than two signals, and more than two optical carrier sources 54 and an E/O converters 56 can also be used. FIG. 16 shows a circuit schematic of one embodiment of the parser 64 , differential encoders 69 , and Manchester encoders 52 . That embodiment can be, for example, in the form of an integrated circuit, such as an application specific integrated circuit, a field programmable gate array, a general purpose integrated circuit, other integrated circuits, or discrete components. FIG. 17 shows another embodiment of a portion of the transmitter 20 around the filter 60 . That embodiment includes a first amplifier 70 in front of the filter 60 , a second amplifier 70 after the filter 60 , and a feedback loop including a-processor 72 . The first amplifier 70 and the feedback loop provide controlled signal gain to compensate for variations in the data signal. For example, one or more parameters (e.g., gain and gain profile) of the first amplifier 70 can be controlled through the feedback loop, which can include the processor 72 and/or other circuitry, such as an application specific integrated circuit, a general purpose integrated circuit, a field programmable gate array, and discrete components, to process the feedback signal and control the first amplifier 70 . The second amplifier 70 provides additional gain, and it can be eliminated if sufficient gain is provided by the first amplifier 70 . This embodiment can be modified, such as to utilize a feed-forward loop, to utilize more or less amplifiers 70 , to vary the location of the amplifiers 70 , etc. FIG. 24 illustrates one embodiment of the filter 60 . In that embodiment, the filter 60 includes a low pass stage and a high pass stage which collectively act as a band pass filter. The low pass stage is illustrated as an amplifier, such as a gain limiting amplifier, and the high pass stage is illustrated as a passive filter, such as a passive Bessel filter, although other types of amplifiers, filters, or other devices may be used, and the filter may include active or passive stages. In some embodiments, the order in which the stages are arranged and the number of stages may be changed. In other embodiments, one or more of the amplifiers 70 illustrated in FIG. 17 may operate as one or more of the filter stages, such as the gain limiting amplifier. In other embodiments, the filter 60 may be a filter other than a band pass filter. The filter 60 may be used, for example, to facilitate duobinary encoding by selecting filter characteristics which compliment the differential encoder 69 or other devices. FIG. 18 shows an embodiment of the transmitter interface 50 including a short reach interface (“SRI”) receiver 74 and a SONET performance monitor 76 . In the illustrated embodiment, the SRI 74 converts the incoming data signal into two or more parallel, lower bit rate signals. For example, the SRI can convert an optical OC-192 signal into sixteen parallel, 622 Mbps electrical signals. The SONET performance monitor 76 , for example, can perform section monitoring and termination functions. FIG. 19 shows a receiver 22 including a filter 80 , an optical to electrical (“O/E”) converter 82 , and an interface 84 . That receiver 22 can receive the optical data signals generated by the transmitters 20 of the present invention without the need for Manchester, differential, or duobinary decoders. The receiver 22 can also include other features, such as FEC decoding, assembling two or more data signals, automatic gain control (“AGC”), clock and data recovery (“CDR”), deserializing, etc. The filter 80 filters one or more signals from the incoming optical data signal Λ o . For example, in a WDM system 10 the filter can be used to select among the several signals and to reduce the noise in the optical data signal Λ o , while in a single channel system 10 the filter 80 can be used to filter noise. In some embodiments, such as single channel systems where noise is not of concern, the filter 80 can be eliminated. The filter 80 can be a single stage or multiple stage filter, can be a single pass or a multiple pass filter, and can utilize one or more types of filters. For example, the filter 80 can have one stage including one or more fiber Bragg gratings and another stage including one or more Mach-Zehnder interferometric filters. The filter 80 can also include other types of filters, such as a fiber Bragg Fabry-Perot filter, a notched filter, a phase shifted filter, a bulk grating, etc., and can, for example, provide one or more filtered signals to one or more receivers 22 . Many other types and combinations of filters 80 are also possible. The O/E converter 82 converts the optical data signal Λ o into one or more corresponding electrical signals. The interface 84 provides a connection for data being received and is analogous to the interface 50 in the transmitter 20 . FIG. 20 shows another embodiment of the receiver 22 including a FEC decoder 86 . That receiver 22 can be used to receive data signals which are FEC encoded, such as can be transmitted by the transmitter 20 illustrated in FIG. 10 . FIG. 21 shows another embodiment of the receiver 22 including an assembler 88 that can be used to receive separated data signals, such as those transmitted by the transmitter 20 illustrated in FIG. 11 . In that embodiment, the received optical signal is split between two filters 80 , each of which filters one of the signals to be received. In other embodiments, the separate filters 80 can be replaced by a single filter (e.g. a bulk grating or an arrayed waveguide) which can separate from the incoming signal Λ o the two or more data signals of interest. The filtered signals are converted to electrical form by the O/E converters 82 , and the electrical signals are combined by the assembler 88 . In other embodiments, more than two signals can be assembled. The illustrated embodiment also includes a FEC decoder 86 which decodes the forward error correction encoded signals. FIG. 22 shows another embodiment of the receiver 22 that includes automatic gain controllers (“AGC”) 90 , clock and data recovery (“CDR”) circuits 92 , and demultiplexers 94 , which are sometimes referred to as “deserializers”. The demultiplexers 94 separate a serial data signal into plural lower bit rate data signals, which are assembled by the assembler 88 . The assembler 88 produces the assembled data as several separate data signals which are FEC decoded and combined into a single signal by the interface 84 . The demultiplexing or deserializing of the data signal into several lower bit rate signals facilitates further processing of the signal, such as assembling and FEC decoding. For example, in some circumstances it is more practical to perform parallel processing on several lower bit rate signals than it is to perform the same operation on a single, high bit rate signal. Some or all of the data processing in the receiver 22 can be done with several parallel low bit rate signals. FIG. 23 shows an embodiment of the receiver interface 74 including a SONET performance monitor 96 and a short reach interface (“SRI”) transmitter 98 . The SONET performance monitor 96 , for example, can perform section monitoring and termination functions. The SRI 98 combines the parallel data signal into a higher bit rate, serial signal. The receiver interface 74 is analogous to the transmitter interface 50 . FIG. 25 illustrates one embodiment of a filter 80 which may be used, for example, in the receiver 22 . In that embodiment, the filter 80 includes one periodic filter stage, such as a Mach-Zehnder filter, and one band filter, such as a Bragg grating filter. Other types of periodic and band filters may be used in the filter 80 . In other embodiments, the order of the stages may be different, the filter 80 may include more or less stages, different types. of stages, and different types of filters. Many variations and modifications can be made to the present invention without departing from its scope. For example, advantages of the present invention can be realized with different numbers, configurations, and combinations of components in the transmitters 20 and receivers 22 . Similarly, different numbers and forms of electrical and optical data signals can also be utilized with the present invention. Many other variations, modifications, and combinations are taught and suggested by the present invention, and it is intended that the foregoing specification and the following claims cover such variations, modifications, and combinations.

A method of transmitting an optical communications signal, comprising receiving a first signal, encoding the signal with a differential or duobinary encoding scheme, encoding the signal with an oscillating signal component, and sub-carrier modulating the signal onto a sub-carrier of an optical carrier signal. The invention also relates to corresponding systems and apparatuses.

FIELD OF THE INVENTION This invention relates to improvements in interactive story books and methods using interactive story books to teach children, especially interactive story books having selectively positionable sticker-inserts. BACKGROUND OF THE INVENTION There are hundreds of story books on the market today for instructing and entertaining children. Of the children's books intended for instructing children, the most effective are those which rely on the actions of the child to interact physically with each lesson or story that he/she is being taught. These are collectively referred to as interactive or activity books and usually include pages of either pictures or text (or both) which are incomplete, hidden or shown in a scrambled arrangement. The child is encouraged to unscramble, complete or uncover (by, for example, lifting or sliding a panel) the arrangement of pictures and/or text which are designed to make up the particular lesson or story. It is through this physical interaction with the pictures and text that the child not only becomes engrossed in a particular lesson, or taught a particular story, but is entertained in the process and is more likely to continue with other lessons or stories. The child is attracted to each situation or exercise more as a game or a puzzle and is, therefore, more likely to become better engaged, with a better chance for satisfactory retention. As the child physically interacts with each lesson, he or she is more likely to retain the teachings of the lesson and to progress than if learning from less interactive story books such as simple picture or ABC books. The interactive story books of the present invention involve the provision of a) a first informative element that presents pieces of information in connection with each story, or a portion thereof, in the form of one or more (e.g., a related series of) words, pictures, symbols, colors, or other media of communication perceptible to a child; b) an empty space adjacent to such first informative element; and, c) a second informative element that is one of a number of stickers or the like supplied on a separate or remote sheet (either bound or inserted into the story book), each one of which includes a single exposed (front) face on which is presented additional information also in the form of one or more words, pictures, symbols, colors, or other media of communication perceptible to a child. The method of teaching of the present invention involves having the child compare the first informative element with the stickers to determine which sticker most closely relates to the first informative element. The child then positions, as the second informative element the chosen sticker and secures such second informative element in the empty space. Each interactive children's book functions as an important educational tool by using an entertaining activity to "lure" children away from other less educational, albeit entertaining, daily activities, such as watching television. Interactive children's books teach and encourage children to learn through direct physical involvement. Through this involvement the child becomes an important part of the teaching/learning process. The books teach children to learn by requiring the child to use his or her hands and think before doing it. The more "fun" the interactive books are, the more apt the child is to continue to read and learn from books rather than watch television. It is therefore an object of the invention to provide an interactive story book which overcomes the problems of the prior art by further engaging and entertaining a child during the instruction process. It is an object of the invention to provide an interactive story book which encourages at least two direct interactions by a child to further strengthen the teachings of a particular lesson. It is another object of the invention to provide such an interactive story book using selectively positionable stickers wherein each sticker offers a second opportunity for interaction by the child to reinforce the particular lesson further. SUMMARY OF THE INVENTION A method of instruction wherein a child first scans or studies a first element of information, then locates an empty space adjacent to first element. The empty space is intended to receive a second related element of information. After comparing a number of possible second informative elements provided to the child, he or she selects the appropriate second element from a remote source and puts it into the empty space. The second element is initially located on an exposed surface of a movable sticker. The movable sticker includes a hidden surface, on which a third element of information is disposed. The selected movable sticker is placed within the space so that the second element may be viewed together with the first element. The hidden surface is selectively exposed by the child so that the third element may be viewed. The third element is designed to relate to the second element and the second element is designed to relate to the first element. The child is taught and observes any designed relationship between the first element and the second element and any designed relationship between the second element and the third element and having taken an active part in constructing them is expected to learn from such observation and participation. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a story book showing informative elements in accordance with the invention; FIG. 2 is a partial enlarged perspective view of a sticker sheet showing stickers in accordance with one embodiment of the invention; FIG. 3 is a perspective view of a multi-hinged sticker in accordance with another embodiment of the invention; FIG. 4 is a perspective view of the multi-hinged sticker of FIG. 3 showing an unfolded orientation; FIGS. 5a is a perspective view of a story book showing "answer glasses" in accordance with another embodiment of the invention; FIG. 5b is a plan view of the "answer glasses" of FIG. 5a; FIG. 6 is a plan view of a sticker in accordance with another embodiment of the invention showing an unfolded orientation; FIG. 7a is a plan assembly view of a "slide-to-side" sticker in accordance with another embodiment of the invention; FIG. 7b is a plan view of an assembled "slide-to-side" sticker showing a slide panel in a pre-used position; FIG. 7c is a plan view of the assembled "slide-to-side" sticker of FIG. 7b showing the slide panel in a used position; FIG. 8 is a perspective assembly view of a story book and three sticker pages in accordance with another embodiment of the invention; FIG. 9 is a perspective view of a "pop-up" sticker positioned within a page of a story book in accordance with yet another embodiment of the invention; and FIG. 10 is a perspective view of a "rotating wheel" sticker in accordance with another embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a children's book 10 is illustrated having pages 12 and at least one group of informative elements 14. The children's book 10 may be either a bound collection of pages 12 or offered as individual, unbound pages (not shown). An "informative element" is a term used here to describe any picture, word, letter, color, shape, material, raised or embossed surface or sound which is to be viewed, felt, or heard by a child for the purpose of being instructed and/or entertained. The invention anticipates the use of one or more of such informative elements and a group of informative elements may indicate or imply part of a sequence, encouraging the child to think of which elements are missing. For example, the incomplete sentence: "A IS FOR (empty space)" is shown at the top of the page 12 of book 10 in FIG. 1. In this example, the words "A", "IS" and "FOR" represent informative elements 14. Here, three of the four informative elements 14 are provided and an empty space is provided for a fourth. The child must determine the appropriate fourth element 14 which relates to at least one of the other three, such as the word "APPLE". In accordance with a preferred embodiment of the invention, as shown in FIG. 2, the book 12 is provided with a sticker sheet 16 of various informative elements 14 from which the child may choose. The sticker sheet 16 includes an array of stickers 18. For present purposes, the term "sticker" means any of several devices, as described in greater detail below. In this first, preferred embodiment, each sticker 18 is made up of a folded sheet of a material, such as paper, folded along a hinging edge 20, and includes a first inside panel 22, a second inside panel 24, a front outer panel 26, and a rear securement surface 28. The securement surface 28 includes a layer of an appropriate pressure-sensitive adhesive 30. The adhesive 30 is preferably reusable. As an alternative to an adhesive, the securement surface 28 may include a velcro-type fastener, flexible magnet material, or any other appropriate removable fastener. Although paper is a preferred material for the stickers 18, other materials such as cloth or a plastic, such as vinyl may be used. The front outer panel 26 includes an outer informative element 32 such as a picture of an apple or the word "APPLE" or a sentence such as "APPLES ARE RED AND GOOD TO EAT". On at least one of the inside panels 22 and 24 is printed an inside informative element 34 which is different than the outer informative element located on the front outer panel 26, that relates in some manner to the outer informative element 32. For example, the incomplete sentence: "A IS FOR " is made up of a group or sequence of informative elements 14 and a blank space 36. The child uses the clues provided by the sequence of informative elements 14 and searches the sticker sheet 16 for, in this example, another informative element 14 that starts with the letter "A" shown on the front outer panel 26 of any sticker 18, or otherwise fits into the sequence. One correct sticker 18, in this example, would be the one with a picture of an apple on the front outer panel 32. Once chosen, the child may peel the "APPLE" sticker 18 from the sticker page 16, thereby exposing the adhesive 30, and adhere the sticker 18 in the space 36 provided at the end of the incomplete sentence: "A IS FOR ". Once the sentence is thus completed, the child can then open the sticker 18 and learn more about, in this case, apples, such as how to spell apple: "APPLE", what an apple looks like, or that "APPLES ARE RED AND GOOD TO EAT", etc. In the above exercise, the child is instructed in word/picture association, hand/eye coordination, the alphabet, word spelling, and information about apples. The child is also encouraged to become engaged in and be entertained by the "game-like" procedure of picking the correct sticker 18 from the sticker sheet 16 and correctly positioning it within the text. The hidden information that is printed on the inside panel 22, 24 of each sticker 18 will further excite the child's curiosity and thereby further advance the learning process. Depending on the application and the particular age group of the child's book, the blank space 36 may be provided with a symbol such as a number or letter which corresponds to a similar symbol located adjacent to or on the correct sticker 18 on the sticker sheet 16. The child may then use the symbols to help locate the correct sticker 18. In another embodiment the blank space 36 may offer additional clues as to the missing element 14 that are less obvious than the use of matching symbols, as described above. For example, the blank space 36 may be shaped and/or colored as an apple and shown very faintly as a "ghost image". Alternatively, the apple shape may be outlined or printed in multi-color pattern so that the image (the clue) is only visible using special "answer" glasses 38 which have a transparent single-color window 39. In one embodiment, the answer glasses 38 are formed integrally with a cover of the book as a "punch-out" item, as shown in FIGS. 5a-5b. Other variations of the blank space 36, in accordance with the invention include a "scratch and sniff" format, providing, in the above example, the smell of an apple. A scratch-off type format may also be used wherein the child uncovers the clue by removing (through scratching with the edge of a coin, for example) an opaque overlying layer. Although the stickers 18 preferably include a single hinge-line edge 20, i.e., one folded edge, they may include an additional hinge-line edge 40, as illustrated by FIGS. 3 and 4, or more hinge-lines depending on the intended application and degree of child interaction. In such a multi-folded sticker 18 as shown in FIGS. 3 and 4, a low-tack pressure-sensitive adhesive 42 may be provided between the individual panels to avoid premature opening of the stickers 18 prior to their removal from the sticker sheet 16. In another embodiment of the invention, shown in FIG. 6, each of the individual stickers 18 are shaped specifically to provide additional information, thereby effectively functioning as additional informative elements. For use in the above example, one such sticker 18 is formed in the shape of an APPLE, instead of being the picture of the APPLE located on the front outer panel 26 in FIG. 2. In yet another, more elaborate embodiment of the invention, each sticker 18 is provided in the form of a sliding panel assembly 44, as shown in FIGS. 7a-7c. In this embodiment, each panel assembly 44 includes an envelope portion 46, and a slide panel 50. The envelope portion 46 includes a window cutout 48, a rear panel 52, a front panel 54 and a hinge tab 56. In a preferred method of manufacture, the slide panel 50 is formed integrally with the hinge tab 56, connected only by uncut frangible points 58. The entire slide panel 50 including the hinge tab 56 is then folded along the hinge-line 60 to a position adjacent the rear panel 52. The front panel 54 is then folded along the hinge-line 62 to envelop the slide panel 50. The slide panel 50 is made slightly longer than the length of the envelope portion 46 so that a grasping tab 64 protrudes through an open edge 66 of the envelope portion 46 and is accessible to a child, as described below. The slide panel 50 includes stop tabs 67 which contact adhesive stop zones, described below, thereby preventing complete removal of the slide panel 50 from the envelope 46. An appropriate adhesive is mask-applied in zones to the envelope portion 46 prior to folding. The zones include an upper edge 68 of the front panel 54 and a side edge 70 (opposite the open edge 66). The adhesive along the side edge 70 aligns with and adheres to an exposed surface of the hinge tab 56. The adhesive along the upper edge 68 aligns with and adheres to the lower edge 72 of the rear panel 52. Stop zones 74 of adhesive are positioned within the folded envelope portion 46 to contact the stop tabs 67 of the slide panel 50. Additional support zones 76 may be formed with adhesive to ensure smooth and even sliding of the slide panel 50. Prior to applying the adhesive to the slide panel assembly 44 shown in FIG. 7a, appropriate informative elements 14 are zone-printed to a surface of the sliding panel 50 so that a first appearing informative element 32 and a subsequently viewed second informative element 34 may be selectively viewed through the window cutout 48. An appropriate low-tack adhesive is additionally applied to the rear surface of the rear panel 52 so that a child may remove the panel-type sticker and apply it within an appropriate blank space 36. The child may immediately view the first informative element 32 which is, in the example shown in FIG. 7b, a question "WHAT DOES A SAILBOAT LOOK LIKE?". The child may then operatively slide the slide panel 50 from its fully recessed position to a fully extended position and view the second (once hidden) informative element 34, which, in FIG. 7c shows a picture of a sailboat. When the child first draws the sliding panel 50 from the envelope portion 46, the frangible points 58 will break thereby allowing the panel 50 to slide freely. In another related embodiment, a printed and/or colored acetate film may be provided across the window cutout 48 so that the informative elements 32 and 34 which are located on the surface of the sliding panel 50 are altered as the slide panel 50 is drawn from the envelope 46 and the informative elements 32, 34 pass the window cutout 48. In another embodiment of the invention, the sticker 18 is made up of many small pages of informative elements. Each sticker 18, for example, may be offer an entire story, in itself. The child may read a story, for example, in the main story book 10. The story may introduce a certain character, such as Robin Hood and offer a blank space 36 showing a picture of Robin Hood. The child would then choose, from a separate source, one (mini story book) sticker 18 having a similar picture of Robin Hood on its front outer surface. The chosen (mini story book) sticker 18 would include additional information about, in this case, Robin Hood, such as a story of his background. In accordance with another embodiment of the invention, sticker pages 18a-18c may be provided. The sticker pages 18a-18c are stickers 18 which are the size of a full page 12 of the book 10. The sticker pages 18a-18c are made up of four separate pages of a story, for example, all sharing a common hinge-line edge 80. One or a number of these sticker pages 18a-18c, such as those shown in FIG. 8 may be attached to each other along a binding edge 82 to form the book 10. The sticker pages 18a-18c are preferably attached to each other using a bead of rubber-based, reusable glue 84 which is provided adjacent to the hinge-line edge 80 of each sticker page 18a-18c. Other appropriate adhesives may be used in place of the rubber-based glue 84. The order of the pages may be entirely up to the child, or in a preferred embodiment, the child may use a sequence of informative elements to help him choose a correct order. For example, in a twenty page story book, sixteen pages of the story may be provided to a child in a non-alterable order. The child may select the last four pages 12, or one sticker page 18a-18c, from a group of sticker pages (such as from the three shown in FIG. 8, and finish the book and the story. The ending of the story is up to the child depending on which sticker page 18a-18c he selects. Of course, any part or all of the story may be interchangeable. In accordance with another embodiment, each sticker 18 may be constructed from a single folded sheet of paper, such as shown in FIG. 9, and include a pop-up assembly 25 attached to the inside panels 22, 24, such as shown in FIG. 9. The pop-up assembly "pops-up" when the child opens the sticker 18. The stickers 18 may alternatively be provided in the form of wipe-off slates including, as before, a folded sheet of paper having a wipe-off slate assembly located between the inside panels 22, 24. The wipe-off assembly may be a conventional type having a supporting board coated with a wax and an overlying frosted sheet of thin plastic. Any impression formed in the plastic darken as it sticks to the wax of the supporting board. The impressions are easily erased by separating the thin plastic sheet from the supporting board. The child may use the sticker 18 to draw a picture of an apple, for example. The stickers 18 may also be in the form of a rotating wheel card 90 as shown in FIG. 10 which includes a base 92 having various informative elements 94 positioned about a center rotating point 96. A wheel 98 is attached to the base 92 of the card 90 preferably with a paper rivet (not shown in detail) so that the wheel 98 may be rotated about the center point 96. The wheel includes an opening 100 which is sized and shaped to show a single (or a select number) of informative elements 94, such as the picture of an apple in FIG. 10. The back of the rotating wheel card 90 includes an adhesive 102 so that the rotating wheel card 90 may be selected from a sheet of such cards, removed from the sheet and adhered in a page 12 of a book 10, as described above. Once in position in the book 10, the child may freely rotate the wheel 98 of the card 90 to uncover additional informative elements 94.

A story book assembly and a method of teaching wherein a child first studies a first element of information, then locates an empty space adjacent to first element. The empty space is intended to receive a second related element of information. After comparing what is available, the child selects an appropriate second element from a remote source. The second element is initially located on an exposed surface of a movable card. The movable card includes a hidden surface, on which a third element of information is disposed. The hidden surface is selectively exposed by the child so that the third element may be viewed. The selected movable card is then placed within the empty space so that the second element may be viewed together with the first element. The third element relates to the second element and the second element relates to the first element. The child is taught and observes the designed relationship between any first element and the second element and any relationship between the second element and the third element.

This application is a continuation of U.S. application Ser. No. 13/002,684, filed Jan. 5, 2011, now abandoned. FIELD OF THE INVENTION This invention relates to switched mode power converters and a method of operating the same. BACKGROUND OF THE INVENTION The current to drive light emitting diodes (LED) for lighting and other applications is commonly provided by a switched mode power supply or other switched mode power converter. Moreover, a single switched mode power converter may be able to provide the current required for multiple LEDs or LED strings. In some applications it is desirable to be able to separately control or dim such individual LEDs or LED strings. It is well known to provide bypass switches in order to provide this control function. In circumstances when all the bypass switches connected to a switched mode power converter operating as an LED current generator are conducting, such that all the LEDs are off, it is feasible to also turn off the current generator in order to save power. The power savings that can be obtained by switching off a current generator for multiple of strings of LEDs can be substantial. This is illustrated in FIG. 1 . FIG. 1 shows the variation of the driver efficiency with varying light level. Dashed line 1 indicates the driver efficiency where the current generator is always on. Contrastingly, dot-dashed line 2 indicates the efficiency obtainable by selectively switching off the current source, where solid line 3 indicates the on-off duty cycle of the current source so selectively switched. The system modelled in this figure has two bypass switches connected to a single current source. The LEDs connected in parallel with the two bypass switches, that is to say, the two LED channels, are both switched using pulse width modulated (PWM) signals. Both of the LED channels are 100% ON at the 100% light level, but are 50% out of phase. This represents a worst case situation. Thus, the solid curve 3 indicates the percentage of the PWM duty cycle for which the current generator is required to be on. The efficiency for a system which does not turn off the current source is shown in dashed line 1 , whereas dot-dashed line 2 shows the system efficiency when the current generator is turned off when not required. As shown in FIG. 1 a system efficiency improvement from approximately 12% to above 80% may be obtained for a 1% light level. For smaller or zero phase shift between the two bypass switches, and, or alternatively, for PWM duty cycle(s) smaller than 100%, even larger efficiency improvements are possible. The efficiency at partial load, that is to say less than 100%, of solid state LED lighting systems is becoming increasingly important from an integral energy efficiency point of view, or total cost of ownership. With the increasing cost of power, this trend is becoming visible in other areas such as mains-connected consumer systems like personal computers and televisions, professional infrastructure systems such as router stations and server banks, as well as automotive applications. Methods and systems which contribute to power saving for a current generator combined with LED bypassing is thus of significant commercial interest. Three basic methods of operating a switched mode power supply are illustrated in the current vs. time graphs of FIG. 2 . FIG. 2( a ) illustrates continuous conduction mode (CCM) operation. In this mode the current through the power supply inductor is always larger than zero. A second mode of operation is illustrated in FIG. 2( b ). This is the so called boundary conduction mode (BCM), which is also sometimes referred to as critical conduction mode. In this mode of operation the current through the inductor is allowed to fall to zero; however it immediately starts rising again, although in practice it is typically controlled such that it goes a bit negative to allow for power-efficient zero-voltage (or zero-current) turn-on of the control switch. A third mode of operation is illustrated in FIG. 2( c ). In this mode, termed discontinuous conduction mode (DCM), the current is pulsed; that is to say, the current rises to a maximum and then falls to zero, and there is a delay before the start of the next current pulse when the current starts to rise again. From the figure the origin for the term “boundary” conduction mode is apparent: this mode represents the boundary between continuous conduction mode and discontinuous conduction mode. Most current generators operate in continuous conduction mode. If they have been turned off in order to save power and one of the bypass switches stops conducting, the LED current generator needs to be turned on again. Unfortunately, a current converter operated in CCM requires some time for the current to ramp up again; thus the current generator needs to turn on prior to the time when the bypass switch stops conducting. Although it is possible to implement this, additional circuitry is required, which adds to the complexity and cost of the generator. This situation is illustrated in FIG. 3 . This figure shows the pulse width modulation (PWM) signals 301 and 302 for two LED strings. The logical signal NOT OR, 303 , corresponds to the time when the converter may be switched off since both LED strings are turned off and consequently no current is required. Thus current is not required when neither bypass switch 301 is conducting (during period 311 ), nor bypass switch 302 is conducting (during period 312 ). As shown, during part of the PWM cycle 305 , the converter-off signal 303 is high and the converter current 304 is allowed to fall to zero. However, as shown in trace 304 , there is a delay between the falling edge of the converter-off trace 303 , that is moment t 0 , and the availability of the full converter current 304 , that is moment t 1 . This delay, being the ramp up time 306 , depends heavily on the specific implementation and the application, and may be dependent upon such factors as the inductor, the switching frequency, the input or output voltages, and so forth. No fixed value can thus be determined a priori. The problem may be passed on from the current generator designer to an application engineer through offering a user-adjustable ramp-up lead time. Alternatively, the required lead time may be automatically detected as proposed in applicant's co-pending European patent application no. EPO 8102752.6. This, however, requires a relatively complex circuit, especially when the PWM inputs are not generated on chip. There thus remains an ongoing need to provide a switched mode power converter for LED applications which provides for high efficiency partial load operation. SUMMARY OF THE INVENTION It is an object of the present invention to provide a switched mode power converter and method of operating the same which allows for high efficiency partial load operation. According to a first aspect of the present invention, there is provided a method of controlling a switched mode power converter comprising an inductor and a switch and providing an output current for LED applications, the method including the sequential steps of: (a) decreasing the current through the inductor from a maximum value to zero, and (b) immediately thereafter increasing the current through the inductor from zero to the maximum value, and further including the steps of providing an interruption by forcing the switch to be open in response to a first change in a converter control signal, which first change is indicative of an absence of a requirement for every one of a plurality of LED loads, and ending the interruption by ending the forcing open of the switch in response to a second change in the converter control signal, which second change is indicative of a recommencement of the requirement for any one or a plurality of the plurality of LED loads. Thus, according to this aspect of the invention, the above object is met by providing a switched mode power converter which operates in the boundary conduction mode, in combination with cycle-by-cycle control: the method allows for partial load operation by interrupting the boundary conduction mode for a defined period in response to first and second control signals. For the avoidance of doubt, the phrase “absence of every one” when used in this document is synonymous with the phase “presence of none”, rather than merely that not all are present. Thus it is to be interpreted as having the same meaning as the “individual absence of each one”. The condition is only met when none are present, and is not met when some, but only some, are present. Correspondingly, “absence of a requirement for every one” is to be interpreted as indicating that each and every one is separately absent a requirement. Preferably the method further includes a further step of smoothing the output current by means of a smoothing capacitor. This is particularly convenient, in view of the large current ripple which results from boundary conduction mode absent such a smoothing means. Beneficially, the method may provide that the presence or absence of the requirement for the (i)th one of the plurality of LED loads is determined by a control signal PMW(i)_on, and the converter control signal corresponds to the logical combination AND of the PMW(i)_on control signals. Alternatively, the method may provide that the presence or absence of the requirement for the (i)th one of the plurality of LED loads is determined by a control signal PMW(i)_on, and the control signal corresponds to the logical combination NOT AND of the PMW(i)_on control signals. As further alternative, the method may provide that the presence or absence of the requirement for the (i)th one of the plurality of LED loads is determined by a control signal PMW(i)_off, and the converter control signal corresponds to the logical combination NOT OR of the PMW(i)_off control signals. As a yet further alternative, the method may provide that the presence or absence of the requirement for the (i)th one of the plurality of LED loads is determined by a control signal PMW(i)_off, and the control signal corresponds to the logical combination OR of the PMW(i)_off control signals. These four alternatives, in the first and third of which the converter control signal corresponds to a Conv_off signal, and in the second and fourth of which the converter control signal corresponds to a Conv_on signal, provide alternative, simple, methods of controlling the converter, without the requirement for complex circuitry. According to another aspect of the invention, there is provided an integrated circuit for controlling a boundary conduction mode switched mode power supply and adapted to operate according to the above method. Embodying the required circuitry in a single integrated circuit provides an advantageous reduction in the space requirement of a switched mode power supply. According to yet another aspect of the invention there is provided a switched mode power converter for LED application, adapted for operation in boundary conduction mode, and for interruption of operation in the absence of every one of a plurality of LED loads. That is to say, the interruption of operation occurs when none of the plurality of LED loads is present. This provides a particularly suitable means of achieving the above object. Preferably the switched mode power converter comprises a smoothing capacitor. Since the inductor currents in such a switched mode power converter typically varies between zero and twice the required output current, a smoothing capacitor is particularly convenient for reducing the output ripple. Preferably the switched mode power converter is configured to be a buck converter; alternatively, but not exclusively so, it may be configured to be a buck-boost converter. These converter configurations are particularly suited to be operable in boundary conduction mode when combined with PWM bypass switches. These and other aspects of the invention will be apparent from, and elucidated with reference to, the embodiments described hereinafter. BRIEF DESCRIPTION OF DRAWINGS Embodiments of the invention will be described, by way of example only, with reference to the drawings, in which: FIG. 1 illustrates the system efficiency difference which may be obtained by switching the current generator for a partial load LED application; FIG. 2 , (a), (b) and (c) pictorially show operation of a switched mode power converter in continuous conduction mode, boundary conduction mode, and discontinuous conduction mode respectively; FIG. 3 shows idealised traces of various control signals related to an power converter, together with the resulting converter current, when operating in continuous conduction mode; FIG. 4 shows the corresponding control signals and the converter current for an power converter operating in boundary conduction mode; FIG. 5 shows a plot of inductor currents, together with the filtered LED current, for an power converter operated in boundary conduction mode; FIG. 6 shows a schematic of a boundary conduction mode buck converter; FIG. 7 shows a schematic of a boundary conduction mode buck converter having two bypass switch gate drivers, and FIG. 8 shows a schematic circuit diagram showing a control circuit for a single string of LEDs. It should be noted that the Figures are diagrammatic and not drawn to scale. Relative dimensions and proportions of parts of these Figures have been shown exaggerated or reduced in size, for the sake of clarity and convenience in the drawings. The same reference signs are generally used to refer to corresponding or similar features in modified and different embodiments. DETAILED DESCRIPTION OF EMBODIMENTS In a method according to one aspect of the present invention, boundary conduction mode (BCM) is used to control the power converter. In this conduction mode the coil current reverts to zero during every conversion cycle. Thus this conduction mode may be characterised by the quasi continuous variation of the inductor current between zero and a maximum level. In order to provide a near constant output current, the maximum level of current through the inductor is thus twice the output current. This represents a large output ripple; thus a smoothing or filter capacitor on the output is generally required. On the other hand, soft switching is enabled since the switching may be performed at zero current or zero voltage. Consequently, for a non-synchronous implementation of the switch-mode power converter the freewheel diode turns off at zero current allowing for a cheap silicon diode instead of an expensive Schottky diode. Moreover, because the boundary conduction mode supports zero current and/or zero voltage switching, switching losses are significantly reduced yielding optimal power efficiency. Component configurations for typical switched mode power converters will be well-known to the skilled person and are thus not shown. In this aspect of the invention, the method of controlling the converter (which is, in this example, a buck converter) includes cycle-by-cycle current control. Cycle-by-cycle current control involves adjusting the duty cycle of the converter during and on the basis of each complete conversion cycle (during which the inductor or coil current rises from zero to its peak value and returns to zero again). This control principle reacts immediately (within the cycle) on changes in the output load (or input source), and thus allows for LED bypassing. The converter currents resulting from this aspect of the invention is shown in FIG. 4 . Analogous to FIG. 3 for continuous conduction mode, in FIG. 4 the controlled signal for the pulse width modulators for 2 LED strings are shown at traces 401 and 402 . The logical NOT OR trace 403 represents the control signal for the converter-off. Thus this control signal determines the part of the total pulse width modulator cycle time 405 during which current is not required from the converter. Bypass switches for the first and second LED channels are open during periods 411 and 412 respectively. The following four alternatives are possible to determine the converter-off control signal 403 : Conv_off=NOR(LED1_on,LED2on, . . . )  1) Conv_off=AND(LED1_off,LED2_off, . . . )  2) Conv_on=OR(LED1_on,LED2_on, . . . )  3) Conv_on=NAND(LED1_off,LED2_off, . . . )  4) where Conv_off, indicates that the converter-off control signal is high (ie the converter should be off), and Conv_on indicates that the converter-off signal should be low (that is, the converter should be on). The ellipsis ( . . . ), indicates that for in circumstances where there are more than two LED channels, each of the channels should be included in the expression. The four equations above are expressed in terms such as LED1_on, since this provides a convenient and intuitive way of thinking about the relationships; however, it will be immediately apparent that “LED1_on”, is directly equivalent to “PWM1_off” (where “PWM1” can be considered to represent the bypass switch), since it is in fact the bypass switches which control whether the LED channels are on or off. Thus the above four equations to control the Converter-off signal 403 may be equivalently written as: Conv_off=NOR(PWM1_off,PWM2off, . . . )  5) Conv_off=AND(PWM1_on,PWM2_on, . . . )  6) Conv_on=OR(PWM1_off,PWM2_off, . . . )  7) Conv_on=NAND(PWM1_on,PWM2_on, . . . )  8) The output from the converter current, before being smoothed with a smoothing capacitor, is shown in trace 404 . It should be emphasised that this trace is schematic only, since the converter cycles with a frequency which typically is in the range of hundreds of kilohertz, whilst the pulse width modulated LED strings typically cycle with a frequency of the order of 100 Hz to a few kHz. As can be seen at nodes 414 and 424 , the converter current starts to rise from zero immediately on the falling edge of the converter-off signal 403 . Since this represents the start of operation of the converter in boundary conduction mode, it is immediately operating at the appropriate current level for the load. Operation in boundary conduction mode continues throughout the period during which any of the bypass switches are open; that is, whilst converter-off signal 403 is low. Once the converter-off signal 403 goes high at the closing of all of the bypass switches, the power converter is interrupted. Thus the inductor current is allowed to fall to zero; at this moment, the converter switch is not opened thereby preventing the current through the inductor from starting to rise again. Thus the boundary conduction mode operation is interrupted. The interruption is maintained until the converter-off trace 403 returns to zero. This represents a second control signal, a first control signal corresponding to the moment at which the converter-off trace went high. At this moment, shown as node 424 in FIG. 4 , the PWM cycle 405 restarts. Put another way, when the converter-off signal 403 goes high, the power converter is switched off, by forcing its switch open: if the switch is already open at the moment of interruption, it is prevented from closing, whilst if the switch is closed at the moment of the interruption, its state is changed to “open”. At the end of the interruption, that is to say at the moment when the converter-off signal 403 goes low, the forcing function is removed, so the switch is allowed to close, in order to recommence the normal boundary-conduction mode operation. Note that FIG. 4 , shows an idealised form of the converter current, in that the slope of the converter current is shown as constant. In practice, this slope will vary according to the load; in particular, in general, the frequency will reduce when more LED channels are bypassed. Since BCM involves no ramp-up lead time, no complex circuitry is required to delay the timing of the (external) PWM signals; only a simple logical combination of the PWM signals driving the LED bypass switches is used to facilitate the switch-on and switch-off of the power converter. FIG. 5 shows the variation of the inductor or coil current in time, and the corresponding variation of the filtered or smoothed LED current. The inductor current takes the shape of a sawtooth 501 , which varies between a minimum zero value and a maximum value, 700 mA in this instance, which represents twice the average inductor current value. The smoothed or filtered LED current follows an approximately sinusoidal shape, with a phase lag behind the inductor current 501 . The variation in the filtered or smoothed current, is, as to be expected from the operation of the smoothing capacitor, significantly less than that of the inductor current. In this instance the variation is between approximately 280 mA and 380 mA. The function of this smoothing capacitor is thus apparent in avoiding unnecessarily high peak currents being passed to the LED strings. FIG. 6 shows a schematic of another controller according to one aspect of the invention, configured to operate in accordance with the above method. The figure includes drivers for 2 PWM circuits, and the associated diode strings. The system comprises driver 601 configured to drive the gate 612 of switch 602 , the drain current of which is sensed across Rsense 622 . Vbus 603 is connected to the drain 632 of switch 602 , via diode D1, 604 . The converter is completed by the inductor L1, 605 , which is connected between the drain 632 of switch 602 and the LED load circuit 606 . The LED load circuit comprises 2 LED strings: D2, D3 and D4, and D5, D6 and D7 respectively. The strings are switched via PWM switches 616 and 626 respectively; the gate and source of each of PWM switch 616 and 626 are under the control of controller 601 . The PWM switches 616 and 626 switch the respective diode strings D2, D3 and D4, and D5, D6 and D7. In parallel with string D2, D3 and D4 is placed a first smoothing capacitor C1, and equivalent smoothing capacitor C2 is placed in parallel with the other LED string D5, D6 and D7. In operation, the controller controls the operation of switch 602 in order to sequentially charge and discharge inductor L1 ( 605 ) through the LED load circuit 606 . Current control is provided through the sense resistor 622 . In addition the controller 601 controls the PWM switches 616 and 626 in accordance with the respective load requirement of the two LED strings, such that when the respective PWM switch 616 or 626 is closed the respective diode string D2 D3 and D4, or D5, D6 and D7, is bypassed. Capacitors C1 and C2 provide the smoothing function on a string-by-string basis. Inclusion of the parallel smoothing capacitor introduces some additional complexity when combined with LED bypassing, since it is necessary to disconnect the capacitor before the LED is short circuited, in order to prevent large current spikes. Means to achieve this are described in co-pending European patent application 07112960.5, the entire contents of which are hereby incorporated by reference. In particular, the switch-on of the dimmed segment takes longer compared to the case where there is not a parallel smoothing capacitor for each segment. This is because the segment capacitor C1 needs to charge from basically zero volts. This switch-on delay may be acceptable, as it is small compared to the drive period: typically, the delay may be about 40 μs compared with a drive period of 5 ms. When it is acceptable, the effect on the light output of the LED segment can be ignored. Alternatively, the switch-on delay may be compensated for in the duty cycle of the signals driving the bypass switches 616 , 626 . The dead time may be calibrated for the LED arrangement, or monitored and automatically compensated for. Active monitoring and correction has the advantage that temperature and ageing effects are automatically taken into account, at the cost of some additional circuitry to measure the switching time and comparing the measured time with the required duty cycle. As a further alternative, as will be seen in FIG. 7 , the segment driver may comprises a bypass switch 716 , 716 and a segmented capacitor C1, C2, and is also equipped with a second switch 717 , 727 in series with the segmented capacitor C1, C2. The series arrangement of the capacitor and corresponding second switch is connected electrically in parallel to the corresponding LED segment, as is the bypass switch. The second switch and the segmented capacitor are operated to hold the voltage across the LED for the next switch-on phase after the LED is switched off. We thus also refer to the second switch and segmented capacitor as sample-and-hold switch and hold capacitor. FIG. 7 shows a schematic of another controller according to one aspect of the invention, configured to operate in accordance with the above method. The figure includes drivers for 2 PWM circuits, and the associated diode strings. The system comprises driver 701 configured to drive the gate 712 of switch 702 , the drain current of which is sensed across Rsense 722 . Vbus 703 is connected to the drain 632 of switch 702 , via diode D1, 704 . The converter is completed by the inductor L1, 705 , which is connected between the drain 632 of switch 702 and the LED load circuit 706 . The LED load circuit comprises 2 LED strings: D2, D3 and D4, and D5, D6 and D7 respectively. The strings are switched via PWM switches 716 and 626 respectively; the gate and source of each of PWM switch 716 and 726 are under the control of controller 701 . The PWM switches 716 and 726 switch the respective diode strings D2, D3 and D4, and D5, D6 and D7. In parallel with string D2, D3 and D4 is placed a first smoothing capacitor C1, and equivalent smoothing capacitor C2 is placed in parallel with the other LED string D5, D6 and D7. In order to prevent current spikes from capacitors C1 and C2 through the first and second LED strings respectively, further switches 717 and 727 are placed in series with the respective capacitors C1 and C2 across the first and second LED strings. Switches 717 and 727 are also under the control of controller 701 . In operation, this controller controls the operation of switch 702 in order to sequentially charge and discharge inductor L1 ( 705 ) through the LED load circuit 706 . Current control is provided through the sense resistor 722 . In addition the controller 701 controls the PWM switches 716 and 726 in accordance with the respective load requirement of the two LED strings, such that when the respective PWM switch 716 or 726 is closed the respective diode string D2 D3 and D4, or D5, D6 and D7, is bypassed. Capacitors C1 and C2 provide the smoothing function on a string-by-string basis; switches 717 and 727 prevent deleterious high current discharge effects from respective capacitors C1 and C2. The controller in this aspect includes a standby pin (STDBY), although, since the standby function can by carried out by the combination of PWM controls, it is not necessary to include the pin. FIG. 8 shows a schematic circuit diagram, which implements an embodiment of the invention. In this figure, the switched current to an LED string 81 is provided by switch 82 , inductor 83 with inductance L and diode 84 . Only a single LED string 81 is shown in this figure. Switch 82 is connected to ground by means of sense resistor Rs. The switch 82 is driven by a driver drv, which in turn is enabled by flip-flop 85 . The “set” input to the flip-flop is determined by valley or zero detector 86 , and the “reset” input by peak detector 87 . As shown, the PWM is combined (via “AND” logic 88 ), with the peak detector; for multiple LED strings, the PWM signal is replaced by the logical combination described above. PWM produces an artificial peak signal, that is to say, it produces a signal which resets the flip-flop 85 . This reset signal overrides the zero or valley signal. Thus, during the time interval that the PWM signal is on, or high, the switch 82 is forced to remain in an open state. At the end of the interruption—that is, once the PWM signal switches off (or goes low), the normal operation of the driver circuit is resumed. It will be appreciated that due to the inherent delays in, for instance, detector circuits and the switching of transistors, there is usually a brief interval between detecting a zero current and bringing the switch back into conduction mode. Therefore, the inductor current will for a brief period, of a few tens of nanoseconds to around 100 ns or 150 ns perhaps, be zero before rising again. As used in this specification and claims, the term “immediately” will be understood by the skilled person to take on its practical meaning, and thus to encompass such a delay period, which is insignificant when considered relative to the period of the converter. From reading the present disclosure, other variations and modifications will be apparent to the skilled person. Such variations and modifications may involve equivalent and other features which are already known in the art of power converters for LED applications and which may be used instead of, or in addition to, features already described herein. Although the appended claims are directed to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel feature or any novel combination of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the present invention. Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. The applicant hereby gives notice that new claims may be formulated to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom. For the sake of completeness it is also stated that the term “comprising” does not exclude other elements or steps, the term “a” or “an” does not exclude a plurality, a single processor or other unit may fulfil the functions of several means recited in the claims and reference signs in the claims shall not be construed as limiting the scope of the claims.

A switched mode power converter is disclosed, together with a method for operating the same. The power converter is adapted to be operable in the boundary conduction mode, and operation is interruptible in the absence of any load requirement.

[0001] This application claims the benefit of U.S. provisional application No. 60/436,125, filed Dec. 23, 2002, which is incorporated by reference herein in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to assays capable of detecting and monitoring RNase H activity in real time. More specifically, the invention relates to assays for monitoring enzymatic degradation of an RNA-DNA duplex by fluorescence quenching. BACKGROUND OF THE INVENTION [0003] RNase H. RNase H is a known enzyme that degrades RNA hybridized to a DNA template. For example, the E. coli RNase H1 enzyme is responsible for the removal of RNA primers from the leading and lagging strands during DNA synthesis. RNase is also an important enzyme for the replication of bacterial, viral and human genomes. For example, the HIV reverse transcriptase holoenzyme has an RNase H activity located at the C-terminus of the p66 subunit (Hansen et al., EMBO J. 1998, 7:239-243), and inhibition of that enzyme activity affects at least three unique points within the virus's life cycle (Schatz et al., FEBS Lett. 1989, 257:311-314; Mizrahi et al., Nucl. Acids Res. 1990, 18:5359-5363; Furfine & Reardon, J. Biol. Chem. 1991, 266:406412). Moreover, mutations that affect HIV RNase H activity also abolish viral infectivity (Tisdale et al., J. Gen. Virol. 1991, 72:59-66), emphasizing the potential utility for that enzyme as an antiviral target. [0004] There is considerable interest in assays and methods that are capable of detecting and monitoring RNase H activity, and in identifying compounds that may affect or modulate that enzyme activity. Yet, existing assays for RNase H activity, as well as other methods to establish whether and to what extent nucleic acid cleavage has occurred, are typically time consuming and laborious. Moreover, existing assays are also discontinuous and cannot monitor the RNase reaction in real time. This is particularly disadvantageous in applications where a user wishes to establish precise kinetic information for the enzyme, such as to characterize the effect(s) of a new inhibitory compound. [0005] Fluorescence Resonance Energy Transfer (FRET). Sequence-specific hybridization of labeled oligonucleotide probes has been used as a means for detecting and identifying selected nucleotide sequences, and labeling of such probes with fluorescent labels has provided a relatively sensitive, nonradioactive means for facilitating the detection of probe hybridization. Recent detection methods employ the process of fluorescence energy transfer (FRET) rather than direct detection of fluorescence intensity for detection of probe hybridization. Fluorescence energy transfer occurs between a donor fluorophore and a quencher dye (which may or may not be a fluorophore) when the absorption spectrum of one (the quencher) overlaps the emission spectrum of the other (the donor) and the two dyes are in close proximity. Dyes with these properties are referred to as donor/quencher dye pairs or energy transfer dye pairs. [0006] The excited-state energy of the donor fluorophore is transferred by a resonance dipole-induced dipole interaction to the neighboring quencher. This results in quenching of donor fluorescence. In some cases, if the quencher is also a fluorophore, the intensity of its fluorescence may be enhanced. The efficiency of energy transfer is highly dependent on the distance between the donor and quencher, and equations predicting these relationships have been developed by Förster (Ann. Phys. 1948, 2:55-75). The distance between donor and quencher dyes at which energy transfer efficiency is 50% is referred to as the Förster distance (RO). Other mechanisms of fluorescence quenching are also known including, for example, charge transfer and collisional quenching. [0007] Energy transfer and other mechanisms which rely on the interaction of two dyes in close proximity to produce quenching are an attractive means for detecting or identifying nucleotide sequences, as such assays may be conducted in homogeneous formats. Homogeneous assay formats are simpler than conventional probe hybridization assays which rely on detection of the fluorescence of a single fluorophor label, as heterogeneous assays generally require additional steps to separate hybridized label from free label. Traditionally, FRET and related methods have relied upon monitoring a change in the fluorescence properties of one or both dye labels when they are brought together by the hybridization of two complementary oligonucleotides. In this format, the change in fluorescence properties may be measured as a change in the amount of energy transfer or as a change in the amount of fluorescence quenching, typically indicated as an increase in the fluorescence intensity of one of the dyes. In this way, the nucleotide sequence of interest may be detected without separation of unhybridized and hybridized oligonucleotides. The hybridization may occur between two separate complementary oligonucleotides, one of which is labeled with the donor fluorophore and one of which is labeled with the quencher. In double-stranded form there is decreased donor fluorescence (increased quenching) and/or increased energy transfer as compared to the single-stranded oligonucleotides. [0008] Several formats for FRET hybridization assays are reviewed in Nonisotopic DNA Probe Techniques (1992, Academic Press, Inc.; See, in particular, pages. 311-352). Alternatively, the donor and quencher may be linked to a single oligonucleotide such that there is a detectable difference in the fluorescence properties of one or both when the oligonucleotide is unhybridized vs. when it is hybridized to its complementary sequence. In this format, donor fluorescence is typically increased and energy transfer/quenching are decreased when the oligonucleotide is hybridized. For example, a self-complementary oligonucleotide labeled at each end may form a hairpin which brings the two fluorophores (i.e., the 5′ and 3′ ends) into close spatial proximity where energy transfer and quenching can occur. Hybridization of the self-complementary oligonucleotide to its complementary sequence in a second oligonucleotide disrupts the hairpin and increases the distance between the two dyes, thus reducing quenching. A disadvantage of the hairpin structure is that it is very stable and conversion to the unquenched, hybridized form is often slow and only moderately favored, resulting in generally poor performance. Tyagi & Kramer ( Nature Biotech. 1996, 14:303-308) describe a hairpin labeled as described above which comprises a detector sequence in the loop between the self-complementary arms of the hairpin which form the stem. The base-paired stem must melt in order for the detector sequence to hybridize to the target and cause a reduction in quenching. A “double hairpin” probe and methods of using it are described by Bagwell et al. ( Nucl. Acids Res. 1994, 22:2424-2425; See also, U.S. Pat. No. 5,607,834). These structures contain the target binding sequence within the hairpin and therefore involve competitive hybridization between the target and the self-complementary sequences of the hairpin. Bagwell solves the problem of unfavorable hybridization kinetics by destabilizing the hairpin with mismatches. [0009] Homogeneous methods employing energy transfer or other mechanisms of fluorescence quenching for detection of nucleic acid amplification have also been described. (Lee et al., Nuc. Acids Res. 1993, 21:3761-3766) disclose a real-time detection method in which a doubly-labeled detector probe is cleaved in a target amplification-specific manner during PCR. The detector probe is hybridized downstream of the amplification primer so that the 5′-3′ exonuclease activity of Taq polymerase digests the detector probe, separating two fluorescent dyes which form an energy transfer pair. Fluorescence intensity increases as the probe is cleaved. [0010] Signal primers (sometimes also referred to as detector probes) which hybridize to the target sequence downstream of the hybridization site of the amplification primers have been described for homogeneous detection of nucleic acid amplification (U.S. Pat. No. 5,547,861). The signal primer is extended by the polymerase in a manner similar to extension of the amplification primers. Extension of the amplification primer displaces the extension product of the signal primer in a target amplification-dependent manner, producing a double-stranded secondary amplification product which may be detected as an indication of target amplification. Examples of homogeneous detection methods for use with single-stranded signal primers are described in U.S. Pat. No. 5,550,025 (incorporation of lipophilic dyes and restriction sites) and U.S. Pat. No. 5,593,867 (fluorescence polarization detection). More recently signal primers have been adapted for detection of nucleic acid targets using FRET methods. U.S. Pat. No. 5,691,145 discloses G-quartet structures containing donor/quencher dye pairs appended 5′ to the target binding sequence of a single-stranded signal primer. Synthesis of the complementary strand during target amplification unfolds the G-quartet, increasing the distance between the donor and quencher dye and resulting in a detectable increase in donor fluorescence. Partially single-stranded, partially double-stranded signal primers labeled with donor/quencher dye pairs have also recently been described. For example, EP 0 878 554 discloses signal primers with donor/quencher dye pairs flanking a single-stranded restriction endonuclease recognition site. In the presence of the target, the restriction site becomes double-stranded and cleavable by the restriction endonuclease. Cleavage separates the dye pair and decreases donor quenching. EP 0 881 302 describes signal primers with an intramolecularly base-paired structure appended thereto. The donor dye of a donor/quencher dye pair linked to the intramolecularly base-paired structure is quenched when the structure is folded, but in the presence of a target a sequence complementary to the intramolecularly base-paired structure is synthesized. This unfolds the intramolecularly base-paired structure and separates the donor and quencher dyes, resulting in a decrease in donor quenching. Nazarenko, et al. (U.S. Pat. No. 5,866,336) describe a similar method wherein amplification primers are configured with hairpin structures which carry donor/quencher dye pairs. [0011] There exists, therefore, a continuing need for assays and methods that are capable of detecting and/or monitoring degradation of RNA and other nucleic acids, e.g., by enzymes such as RNase H. In particular, there is need for assays and methods that are capable of detecting and monitoring such activity in real time. [0012] The citation of any reference in this section or throughout the text of this application does not constitute an admission that such reference is available as “prior art” to the invention described and claimed herein. SUMMARY OF THE INVENTION [0013] The present invention overcomes disadvantages of the prior art by providing a method of detecting a nuclease-mediated cleavage of a target nucleic acid through (a) hybridizing a target nucleic acid to a fluorescently labeled oligonucleotide probe complementary to the target nucleic acid and containing a flourophor at one terminus and a quenching group at the other terminus, wherein (i) when the probe is unhybridized to the target nucleic acid, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor; (b) contacting the probe-target hybrid with an agent having nuclease activity in an amount sufficient to selectively cleave the target nucleic acid and thereby release the intact probe; and (c) detecting the release of the probe by measuring a decrease in the flourescent signal of the flourophor as compared to the signal of the probe-target hybrid. [0014] Another embodiment of the invention provides a method for measuring RNase H activity of an agent, by hybridizing a target RNA to a fluorescently labeled oligodesoxyribonucleotide probe complementary to the target RNA and containing a flourophor at one terminus and a quenching at the other terminus, wherein (i) when the probe is unhybridized to the target RNA, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor; contacting the probe-target hybrid with the agent in an amount sufficient to selectively cleave the target RNA and thereby release the intact probe; and measuring a decrease in the flourescent signal of the flourophor as compared to the signal of the probe-target hybrid. [0015] In one embodiment, the agent is selected from the group consisting of RNase H, reverse transcriptase, E. coli Rnase H1 and H2, Human RNase H1 and H2, hammerhead ribozymes, HBV reverse transcriptase, and integrase. In a preferred embodiment, the reverse transcriptase is HIV reverse transcriptase. In yet another embodiment, the reverse transcriptase contains a RNase domain. [0016] In an embodiment of the present invention, the probe is DNA, and the target is the DNA:RNA hybrid substrate. Also in an embodiment of the present invention, the probe is at least 18 nucleotides in length. [0017] In the present invention, the probe, when unhybridized to the target nucleic acid or RNA, adopts a hairpin secondary structure conformation that brings the fluorophor and quencher into proximity. In addition, where the RNase H-mediated or nuclease reaction is performed in the presence of a compound, wherein a difference in the rate of the decrease in the flourescent signal of the flourophor during the nuclease reaction, as compared to the decrease observed when the same reaction is conducted in the absence of the compound, the method is indicative of the ability of the compound to either inhibit or enhance the nuclease activity of the agent. [0018] In one embodiment of the invention, the method monitors the flourescent signal of the flourophor during the RNase H-mediated or nuclease reaction. [0019] The present invention also provides a method of screening for a modulator of the nuclease activity of an agent by hybridizing a target nucleic acid to a fluorescently labeled oligonucleotide probe complementary to the target nucleic acid and containing a flourophor at one terminus and a quenching group at the other terminus, wherein (i) when the probe is unhybridized to the target nucleic acid, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor; preparing two samples containing the probe-target hybrid; contacting the probe-target hybrid of a first sample with the agent in an amount sufficient to selectively cleave the target nucleic acid and thereby release the intact probe; contacting the probe-target hybrid of a second sample with the agent in an amount sufficient to selectively cleave the target nucleic acid and thereby release the intact probe in the presence of a candidate compound, which is being tested for its ability to modulate the nuclease activity of the agent; detecting the release of the probe in each sample by measuring a decrease in the flourescent signal of the flourophor as compared to the signal of the probe-target hybrid; and comparing the rate of the decrease in the flourescent signal of the flourophor in the two samples, wherein a difference in the rate of the decrease in the flourescent signal of the flourophor during the nuclease reaction in the two samples is indicative of the ability of the compound to either inhibit or enhance the nuclease activity of the agent. [0020] In a preferred embodiment, the a greater extent or relative rate of decrease of the flourescent signal of the flourophor in the second sample compared to the first sample indicates that the candidate compound is an agent agonist. In another embodiment, a lesser extent or relative rate of decrease of the flourescent signal of the flourophor in the second sample compared to the first sample indicates that the candidate compound is an agent antagonist. [0021] The present invention also provides for a kit for measuring a nuclease activity of an agent, comprising a target nucleic acid and a fluorescently labeled oligonucleotide probe complementary to the target nucleic acid and containing a flourophor at one terminus and a quencher at the other terminus, wherein (i) when the probe is unhybridized to the target nucleic acid, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor. [0022] In one embodiment of the kit, the probe is at least 18 nucleotides in length. In another embodiment of the kit, the probe, when unhybridized to the target nucleic acid, adopts a hairpin secondary structure conformation that brings the fluorophor and quencher into proximity. [0023] In a preferred embodiment of the kit, the probe is DNA, and the target nucleic acid is DNA:RNA hybrid substrate. [0024] In one embodiment of the kit, the invention also has an agent. In a preferred embodiment, the agent is selected from the group consisting of RNase H, reverse transcriptase, E. coli RNase H1 and H2, Human RNase H1 and H2, hammerhead ribozymes, HBV reverse transcriptase, and integrase. In yet another embodiment, the reverse transcriptase is HIV reverse transcriptase. [0025] The present invention also provides for an assay mixture for measuring a nuclease activity of an agent, comprising a target nucleic acid and a fluorescently labeled oligonucleotide probe complementary to the target nucleic acid and containing a flourophor at one terminus and a quenching group at the other terminus, wherein (i) when the probe is unhybridized to the target nucleic acid, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor. [0026] In a preferred embodiment of the assay, the probe is DNA, and the target nucleic acid is RNA. In yet another embodiment, the probe and the target nucleic acid are hybridized to each other to form a probe-target hybrid. [0027] In one embodiment of the assay mixture, there is also an agent. In a preferred embodiment, the agent is selected from the group consisting of RNase H, reverse transcriptase, E. coli RNase H1 and H2, Human RNase H1 and H2, hammerhead ribozymes, HBV reverse transcriptase, and integrase. In a further embodiment, the reverse transcriptase is HIV reverse transcriptase. BRIEF DESCRIPTION OF THE FIGURES [0028] [0028]FIGS. 1A-1B show PAGE analysis of substrate RNA synthesized by a T7 RNA polymerase reaction. FIG. 1A shows RNA product evaluated on a denaturing (7M Urea-15% polyacrylamide) gel, whereas FIG. 1B shows a non-denaturing (native 15% polyacrylamide) gel. Nucleic acids in both gels were detecting by ethidium bromide staining. The gels in both figures were loaded as follows: [0029] lane 1: 49-mer template DNA (SEQ ID NO:2); [0030] lane 2: control RNA 125-mer; [0031] lane 3-6: RNA derived from the T7 RNA polymerase reaction; and [0032] lane 7: 49-mer template DNA. [0033] [0033]FIGS. 2A-2D show radiolabeled RNA-DNA substrate evaluated by PAGE. FIG. 2A illustrates the substrate DNA nucleotide sequence (SEQ ID NO:2) annealed to the substrate RNA (SEQ ID NO: 1). FIG. 2B shows the image of a non-denaturing gel loaded with the unlabeled RNA annealed to 33 P-end labeled DNA. FIGS. 2C and 2D show denaturing and non-denaturing polyacrylamide gels, respectively, that have both been loaded with internally radiolabeled RNA and unlabeled DNA. The method of nucleic acid detection is by phosphoimagery. [0034] [0034]FIGS. 3A-3B show results from a PAGE-based assay for RNase H activity. FIG. 3A shows results from an embodiment of the assay in which an unlabeled RNA/end-labeled DNA substrate was used, whereas FIG. 3B shows results for an alternative embodiment that used a labeled RNA/unlabeled DNA substrate. [0035] [0035]FIG. 4 shows the image of a polyacrylamide gel loaded with unlabeled RNA/end-labeled DNA hybrid digested in an assay for HIV RT RNase H activity. [0036] [0036]FIGS. 5A-5B show plots of HIV RT RNase H activity ascertained from quantitative analysis of the PAGE gels illustrated in FIG. 3A and FIG. 4, respectively. [0037] [0037]FIGS. 6A-6C show PAGE gels run with ssRNA substrate that was incubated with (FIG. 6A) or without (FIG. 6B) 1 U (19 fmol≈2.2 ng) HIV RT RNase H enzyme, and a PAGE gel in which 2.5 pmol RNA-DNA hybrid substrate was incubated with the enzyme to verify RNase H activity (FIG. 6C). [0038] [0038]FIG. 7 is the PAGE gel from an RNase H assay that was run with polyA (lanes 2-3), polyU (lanes 4-5) and 18S RNA (SEQ ID NO:5; lanes 6-7) along with radiolabeled RNA-DNA hybrid substrate. [0039] [0039]FIG. 8 shows the PAGE gel from an RNase H assay that was run with “contaminating oligonucleotides referred to here as Oligo 1 (SEQ ID NO:6; lanes 3-5), Oligo 2 (SEQ ID NO:7, lanes 6-8) and Oligo 3 (SEQ ID NO:8; lanes 9-11). [0040] [0040]FIGS. 9A-9D show results from a PAGE-based RNase H assay using HIV RNase H (FIG. 9A), MMLV RNAse H (FIG. 9B) and mutant MMLV RNase H (FIG. 9C). A quantitative analysis of these data is plotted in FIG. 9D. [0041] [0041]FIGS. 10A-10C provide a schematic illustration of a preferred, real time RNase H assay of the invention. FIG. 10A illustrates an exemplary RNA substrate (SEQ ID NO: 10) annealed to an exemplary DNA probe (SEQ ID NO:9) that is labeled with a fluorophor moiety (F) and a quencher moiety (Q). The 5′- and 3′ regions of the DNA probe are capable of annealing to each other after the RNA substrate has been digested by RNase H, placing the fluorophor moiety and the quencher moiety in sufficient proximity so that the quencher moiety absorbs at least part of the detectable signal emitted by the fluorophor moiety (FIG. 10B). FIG. 10C illustrates a typical fluorescent signal that may be observed in real time as RNase H degrades the RNA substrate in this assay. [0042] [0042]FIGS. 11A-11B are plots of fluorescence intensity measurements from real time RNase H assays of the invention that used HIV RT RNase H (FIG. 11A) and E. coli RNase H1 (FIG. 11B). DETAILED DESCRIPTION [0043] The present invention is directed to a method of a fluorometric assay for real-time monitoring of RNase H activity. Specifically, the invention relates to the quantitative assessment of RNase H activity through a decrease in fluorescence. Definitions [0044] In accordance with the invention, there may be employed conventional molecular biology, microbiology and recombinant DNA techniques within the skill of the art. Such techniques are explained fully in the literature and the terms used here to describe such techniques will generally have the meaning normally used in the art. See, for example, Sambrook, Fitsch & Maniatis, Molecular Cloning: A Laboratory Manual , Second Edition (1989) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (referred to herein as “Sambrook et al., 1989”); DNA Cloning: A Practical Approach , Volumes I and II (D. N. Glover ed. 1985); Oligonucleotide Synthesis (M. J. Gait ed. 1984); Nucleic Acid Hybridization (B. D. Hames & S. J. Higgins, eds. 1984); Animal Cell Culture (R. I. Freshney, ed. 1986); Immobilized Cells and Enzymes (IRL Press, 1986); B. E. Perbal, A Practical Guide to Molecular Cloning (1984); F. M. Ausubel et al. (eds.), Current Protocols in Molecular Biology , John Wiley & Sons, Inc. (1994). [0045] The term “fluorescent label” or “fluorophore” as used herein refers to a substance or portion thereof that is capable of exhibiting fluorescence in the detectable range. Examples of fluorophores that can be used according to the invention include fluorescein isothiocyanate, fluorescein amine, eosin, rhodamine, dansyl, umbelliferone, texas red, Cy5, Cy3 and europium. Other fluorescent labels will be known to the skilled artisan. Some general guidance for designing sensitive fluorescent labelled polynucleotide probes can be found in Heller and Jablonski's U.S. Pat. No. 4,996,143. This patent discusses the parameters that should be considered when designing fluorescent probes, such as the spacing of the fluorescent moieties (i.e., when a pair of fluorescent labels is utilized in the present method), and the length of the linker arms connecting the fluorescent moieties to the base units of the oligonucleotide. The term “linker arm” as used herein is defined as the distance in Angstroms from the purine or pyrimidine base to which the inner end is connected to the fluorophore at its outer end. [0046] The term “cleavage that is enzyme-mediated” refers to cleavage of DNA or RNA that is catalyzed by such enzymes as DNases, RNases, helicases, exonucleases, restriction endonucleases, or retroviral integrases. Other enzymes that effect nucleic acid cleavage will be known to the skilled artisan and can be employed in the practice of the present invention. A general review of these enzymes can be found in Chapter 5 of Sambrook et al, supra. [0047] As used herein, the terms “nucleic acid”, “polynucleotide” and “oligonucleotide” refer to primers, probes, oligomer fragments to be detected, oligomer controls and unlabeled blocking oligomers and shall be generic to polydeoxyribonucleotides (containing 2-deoxy-D-ribose), to polyribonucleotides (containing D-ribose) as well as chimeric polynucleotides (containing 2-deoxy-D-ribose and D-ribose nucleotides), and to any other type of polynucleotide which is an N glycoside of a purine or pyrimidine base, or modified purine or pyrimidine bases. There is no conceived distinction in length between the term “nucleic acid”, “polynucleotide” and “oligonucleotide”, and these terms are used interchangeably. Thus, these terms include double-and single stranded DNA, as well as double- and single stranded RNA. Preferably, the oligonucleotides used in connection with assays of this invention will be at least 10 nucleotides in length, and more preferably between about 10 and 100 nucleotides in length, with oligonucleotides between about 25 and 50 nucleotides in length being even more preferred. [0048] The oligonucleotide is not necessarily limited to a physically derived species isolated from any existing or natural sequence but may be generated in any manner, including chemical synthesis, DNA replication, reverse transcription or a combination thereof. The terms “oligonucleotide” or “nucleic acid” refers to a polynucleotide of genomic DNA or RNA, cDNA, semisynthetic, or synthetic origin which, by virtue of its derivation or manipulation: (1) is not affiliated with all or a portion of the polynucleotide with which it is associated in nature; and/or (2) is connected to a polynucleotide other than that to which it is connected in nature; and (3) is unnatural (not found in nature). Oligonucleotides are composed of reacted mononucleotides to make oligonucleotides in a manner such that the 5′ phosphate of one mononucleotide pentose ring is attached to the 3′ oxygen of its neighbor in one direction via a phosphodiester linkage, and is referred to as the “5′end” end of an oligonucleotide if its 5′ phosphate is not linked to the 3′ oxygen of a mononucleotide pentose ring and subsequently referred to as the “3′end” if its 3′ oxygen is not linked to a 5′ phosphate of a subsequent mononucleotide pentose ring. A nucleic acid sequence, even if internalized to a larger oligonucleotide, also may be said to have 5′ and 3′ ends. Two distinct, non-overlapping oligonucleotides annealed to two different regions of the same linear complementary nucleic acid sequence, so the 3′ end of one oligonucleotide points toward the 5′ end of the other, will be termed the “upstream” oligonucleotide and the latter the “downstream” oligonucleotide. In general, “downstream” refers to a position located in the 3′ direction on a single stranded oligonucleotide, or in a double stranded oligonucleotide, refers to a position located in the 3′ direction of the reference nucleotide strand. [0049] The term “primer” may refer to more than one oligonucleotide, whether isolated naturally, as in a purified restriction digest, or produced synthetically. The primer must be capable of acting as a point of initiation of synthesis along a complementary strand (DNA or RNA) when placed under reaction conditions in which the primer extension product synthesized is complementary to the nucleic acid strand. These reaction conditions include the presence of the four different deoxyribonucleotide triphosphates and a polymerization-inducing agent such as DNA polymerase or reverse transcriptase. The reaction conditions incorporate the use of a compatible buffer (including components which are cofactors, or which affect pH, ionic strength, etc.), at an optimal temperature. The primer is preferably single-stranded for maximum efficiency in the amplification reaction. [0050] A complementary nucleic acid sequence refers to an oligonucleotide which, when aligned with the nucleic acid sequence such that the 5′ end of one sequence is paired with the 3′ end of the other. This association is termed as “antiparallel.” Modified base analogues not commonly found in natural nucleic acids may be incorporated (enzymatically or synthetically) in the nucleic acids including but not limited to primers, probes or extension products of the present invention and may include, for example, inosine and 7-deazaguanine. Complementarity of two nucleic acid strands may not be perfect; some stable duplexes may contain mismatched base pairs or unmatched bases and one skilled in the art of nucleic acid technology can determine their stability hypothetically by considering a number of variables including, the length of the oligonucleotide, the concentration of cytosine and guanine bases in the oligonucleotide, ionic strength, pH and the number, frequency and location of the mismatched base pairs. The stability of a nucleic acid duplex is measured by the melting or dissociation temperature, or “T m .” The T m of a particular nucleic acid duplex under specified reaction conditions. It is the temperature at which half of the base pairs have disassociated. [0051] As used herein, the term “target sequence” or “target nucleic acid sequence” refers to a region of the oligonucleotide which is to be either amplified, detected or both. The target sequence resides between the two primer sequences used for amplification or as a reverse transcribed single-stranded cDNA product. The target sequence may be either naturally derived from a sample or specimen or synthetically produced. [0052] As used herein, a “probe” comprises a ribo-oligonucleotide which forms a duplex structure with a sequence in the target nucleic acid, due to complementarity of at least one sequence of the ribo-oligonucleotide to a sequence in the target region. The probe, preferably, does not contain a sequence complementary to the sequence(s) used to prime the polymerase chain reaction (PCR) or the reverse transcription (RT) reaction. The probe may be chimeric, that is, composed in part of DNA. Where chimeric probes are used, the 3′ end of the probe is generally blocked if this end is composed of a DNA portion to prevent incorporation of the probe into primer extension product. The addition of chemical moieties such as biotin, fluorescein, rhodamine and even a phosphate group on the 3′ hydroxyl of the last deoxyribonucleotide base can serve as 3′ end blocking groups and under specific defined cases may simultaneously serve as detectable labels or as quenchers. Furthermore, the probe may incorporate modified bases or modified linkages to permit greater control of hybridization, polymerization or hydrolyzation. [0053] The term “label” refers to any atom or molecule which can be used to provide a detectable (preferably quantifiable) real time signal. The detectable label can be attached to a nucleic acid probe or protein. Labels provide signals detectable by either fluorescence, phosphorescence, chemiluminescence, radioactivity, colorimetric (ELISA), X-ray diffraction or absorption, magnetism, enzymatic activity, or a combination of these. [0054] The term “absorber/emitter moiety” refers to a compound that is capable of absorbing light energy of one wavelength while simultaneously emitting light energy of another wavelength. This includes phosphorescent and fluorescent moieties. The requirements for choosing absorber/emitter pairs are: (1) they should be easily functionalized and coupled to the probe; (2) the absorber/emitter pairs should in no way impede the hybridization of the functionalized probe to its complementary nucleic acid target sequence; (3) the final emission (fluorescence) should be maximally sufficient and last long enough to be detected and measured by one skilled in the art; and (4) the use of compatible quenchers should allow sufficient nullification of any further emissions. [0055] As used in this application, “real time” refers to detection of the kinetic production of signal, comprising taking a plurality of readings in order to characterize the signal over a period of time. For example, a real time measurement can comprise the determination of the rate of increase of detectable product. Alternatively, a real time measurement may comprise the determination of time required before the target sequence has been amplified to a detectable level. [0056] The term “chemiluminescent and bioluminescent” include moieties which participate in light emitting reactions. Chemiluminescent moieties (catalyst) include peroxidase, bacterial luciferase, firefly luciferase, functionlized iron-porphyrin derivatives and others. [0057] As defined herein, “nuclease activity” refers to that activity of a template-specific ribo-nucleic acid nuclease, RNase H. As used herein, the term “RNase H” refers to an enzyme which specifically degrades the RNA portion of DNA/RNA hybrids. The enzyme does not cleave single or double-stranded DNA or RNA and a thermostable hybrid is available which remains active at the temperatures typically encountered during PCR. Generally, the enzyme will initiate nuclease activity whereby ribo-nucleotides are removed or the ribo-oligonucleotide is cleaved in the RNA-DNA duplex formed when the probe anneals to the target DNA sequence. [0058] The term “hybridization or reaction conditions” refers to assay buffer conditions which allow selective hybridization of the labeled probe to its complementary target nucleic acid sequence. These conditions are such that specific hybridization of the probe to the target nucleic acid sequence is optimized while simultaneously allowing for but not limited to cleavage of the probe-target hybrid by a nuclease enzyme or by another agent having a nuclease activity. The reaction conditions are optimized for co-factors, ionic strength, pH and temperature. RNase H Molecular Beacon Assay [0059] In preferred embodiments, the assays and methods of the present invention detect RNase H activity and/or other nuclease-mediated cleavage of nucleic acids in an assay that is referred to here as a “molecular beacon” assay. An exemplary embodiment of such an assay is illustrated schematically in FIGS. 10A-10C. The assay detects degradation of a nucleic acid substrate which, preferably, is an RNA substrate that is annealed to at least one region or part of an oligonucleotide probe. In preferred embodiments, the oligonucleotide probe is a DNA probe (e.g., a deoxyoligonucleotide probe), which may also be referred to in the context of this invention as the DNA “substrate” moiety. Typically, both the oligonucleotide probe and the RNA substrate will be oligonucleotide molecules that are between about 10 and about 100 nucleotides in length and may be, e.g., between about 10-50 nucleotides in length, more preferably between 15-25 nucleotides length. In preferred embodiments, the oligonucleotide probe is at least 18 nucleotides in length. [0060] [0060]FIG. 10A shows an exemplary RNA substrate having the nucleotide sequence set forth in SEQ ID NO: 10 and annealed to an exemplary DNA probe having the nucleotide sequence set forth in SEQ ID NO:9. However, these sequences are only exemplary, for the purposes of illustrating and better explaining the present invention. The actual sequence of the RNA substrate and/or the oligonucleotide probe is not critical and those skilled in the art will be able to readily design other appropriate sequences without undue experimentation. [0061] Nevertheless, the substrate and probe sequences will preferably have certain properties. In particular, the oligonucleotide probe preferably comprises regions of sequences that are referred to here as the 5′-region and the 3′-region and are located at the 5′ and 3′-ends of the oligonucleotide, respectively. These 5′- and 3′-regions preferably comprise nucleotide sequences that are complementary to each other such that, when the oligonucleotide probe is not annealed to a RNA substrate, the two regions may hybridze to each other and thereby form a hairpin loop, such as the exemplary hairpin loop illustrated in FIG. 10B. [0062] The oligonucleotide probe also preferably comprises a third sequence region, which is preferably situated between the probe's 5′-region and its 3′-region, and is therefore referred to here as the “center region” of the oligonucleotide probe. The actual sequence of this center region also is not critical to practicing the present invention. It is sufficient that the center region of the oligonucleotide probe be sufficiently complementary to at least a part of the RNA substrate so that the two molecules are capable of hybridizing to each other under assay conditions. [0063] The oligonucleotide probe used in a molecular beacon assay of this invention may also comprise a detectable label which, in preferred embodiments, comprises a fluorescent or “fluorophor” moiety that emits a detectable fluorescent signal. More preferably, the oligonucleotide probe further comprises a “quencher” quencher moiety which, when positioned in sufficient proximity to the fluorophor moiety, is capable of absorbing at least a part of the fluorescent signal emitted by that fluorophor moiety. Suitable fluorescent labels and appropriate quencher for use therewith are well known in the art. For example, in one preferred embodiment the fluorophor moiety may be fluorescein and the quencher moiety may be dabcyl. Both of these labels are commercially available, e.g., from Stratagene (La Jolla, Calif.). However, a variety of other such moieties are generally available and/or otherwise known in the art, and the use of such other fluorophor and quencher moities is also contemplated in the present invention. Those skilled in the art will be able to readily identify other labels and quenchers that are suitable for and may be used in a molecular beacon or other assay of this invention. [0064] The fluorophor and quencher moities are preferably attached at opposite ends of the oligonucleotide probe. Thus, the exemplary oligonucleotide probe in FIG. 10A is illustrated as having the fluorophor moiety attached to the 3′-region (e.g., on the 3′-end) of the oligonucleotide probe while the quencher moiety is attached to the 5′-region (e.g., on the 5′-end) of the oligonucleotide probe. However, embodiments in which the quencher moiety is attached to the 3′-region and the fluorophor moiety is attached to the 5′-region are also contemplated and generally will be equally preferred. [0065] It therefore is not critical which particular fluorophor or quencher moiety is attached to which particular end of the oligonucleotide probe. However, the two moieties are preferably positioned such that, when the oligonucleotide probe is annealed to the RNA substrate, the fluorophor and quencher moities are sufficiently extraneous from each other that the quencher moiety does not absorb a detectable amount of signal from the fluorophor moiety. However, when the 5′- and 3′-regions of the oligonucleotide probe are hybridized to each other and/or the oligonucleotide probe forms a hairpin loop (as shown, e.g., in FIG. 10B), the fluorophor and quencher moieties should be sufficiently close together so that at least part of the fluorescent signal emitted by the fluorophor is absorbed by the quencher such that the intensity of fluorescent signal from the sample is detectably reduced. [0066] In preferred embodiments therefore, a molecular beacon of the assay will begin with a sample containing an oligonucleotide probe and a RNA substrate under conditions so that the oligonucleotide probe and RNA substrate are annealed to each other, as illustrated in FIG. 10A. An enzyme or other molecule having or suspected of degrading RNA (for example, an RNase H enzyme) may then be added to the sample and, optionally, a test compound suspected of modulating the enzymatic activity may also be added. The probe and substrate are then incubated in the presence of the enzyme and optional test compound, and the fluorescent signal intensity of the sample is measured. Without being limited to any particular theory or mechanism of action, it is understood that, as RNA substrate is digested in the sample, an increasing fraction of the oligonucleotide probes will self-hybridize, e.g., to form hairpin loops as illustrated in FIG. 10B. Thus, as the RNase reaction progresses, an increasing number of the oligonucleotide probes will adopt a conformation where the quencher moiety is brought into close proximity with the fluorophor moiety, so that its fluorescent signal effectively attenuated or “quenched”. This effect may be observed as the reaction progresses, by monitoring the fluorescence intensity of the sample. In particular, it is understood that as the RNA substrate is digested, the observed fluorescence intensity will decrease over time producing a profile such as the exemplary profile shown in FIG. 10C. Benefits and Uses [0067] A rate-based or kinetic assay has been developed to evaluate RNase H activity. The power of the assay is underscored by the ability utilize multiple fluorophors, the application of this assay to high-throughput screening for drug development, and for rapid evaluation of kinetic constants. In combination with assays performed in a radioactive format we have shown that this assay is specific for the degradation of RNA in an RNA/DNA hybrid substrate. This assay is superior to other RNase H assays in the literature by several (gel-based and radioactive non-TCA precipitable count, and IGEN capture assay) criteria. [0068] First, the assay is rapid and applicable to high throughput screening (HTS) in multiple well formats, including but not limited to 96-, 384- and 1536-well formats. Second, sensitivity of this assay is equal or better relative to polyacrylamide gel-based assays. This assay is orders of magnitude more sensitive than the traditional radioactivity release assay (see, e.g. Stavrianopoulos, Proc. Natl. Acad. Sci. U.S.A. 1976, 73:1087-1091; Papaphilis & Kamper, Anal. Biochem. 1985, 145:160-169; Krug & Berger, Proc. Natl. Acad. Sci. U.S.A. 1989, 86:3539-3543; Crouch et al., Methods Enzymol. 2001, 341:395413; Lima, Methods Enzymol. 2001, 341:430-440; Synder & Roth, Methods Enzymol. 2001, 341440452). Third, relative to the IGEN assay (96-well format) it is a direct determination of RNase H activity and does not rely on a capture of the product for detection of enzyme activity or inhibition of enzyme activity. Fourth, the assay is rate-based and allows for direct determination of inhibition constants. Combined, this assay provides the sensitivity of a radioactive gel-based assay with the greater speed than a radioactive release assay and does not require a second event for detection of enzyme activity as does the IGEN capture assay. [0069] The commercial value of this assay is drug development. Modifications of this assay will allow for the development of new assays such as HIV integrase or other RNA and DNA metabolizing enzymes. EXAMPLES [0070] The present invention is also described by means of the following examples. However, the use of these or other examples anywhere in the specification is illustrative only and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to any particular preferred embodiments described herein. Indeed, many modifications and variations of the invention may be apparent to those skilled in the art upon reading this specification and can be made without departing from its spirit and scope. The invention is therefore to be limited only by the terms of the appended claims along with the full scope of equivalents to which the claims are entitled Example 1 Measurement of RNase H Activity in an Endpoint Assay [0071] This example describes experiments which use an endpoint, PAGE analysis based assay to measure the activites of two exemplary RNase H enzymes: E. coli RNase H1 and HIV reverse transcriptase. In HIV, the p66/p51 reverse transcriptase (RT) holoenzyme has RNase activity which is located at the C-terminal end of the p66 subunit (Hansen et al., EMBO J. 1988, 7:239-243; Kohlstaedt et al., Science 1992, 256:1783-1790; and Sarafianos et al., EMBO J. 2001, 20:1449-1461). Mutations that effect that enzyme's RNase H activity also abolish virus infectivity (Id.), making the RNase H an attractive target for novel antiviral therapies. [0072] Materials and Methods: [0073] RNase H. Samples of HIV p66/p51 heterodimer were obtained from Enzyco, Inc. (Replidyne Inc., Louisville Colo.) Methods for the recombinant expression, purification and characterization of this enzyme have been previously described (Thimmig & McHenry, J. Biol. Chem. 1993, 268:16528-16536). Purity of the enzyme samples was verified on polyacrylamide gels. Its specific activity was also assayed and determined to be 27 dNTP inc/μg/60 min, which is comparable to the specific activity of other HIV RT enzymes. Samples of E. coli RNase H1 were purchased from EPICENTR (Madison, Wis.). [0074] RNA-DNA substrate. Initial reactions used a ssRNA molecule annealed to a complementary DNA sequence. Briefly, ssRNA molecules having the nucleotide sequenced set forth in SEQ ID NO: 1 (shown below) were produced by a T7 RNA polymerase reaction using a MEGAshortscript™ High Yield Transcription Kit (Ambion Inc., Austin Tex.). Briefly, annealed oligomers (SEQ ID NOS:A and B, shown below) were used as the DNA substrate for synthesis of the RNA sequence set forth in SEQ ID NO: 1 (shown below) with a T7 RNA polymerase. [0075] The RNA generated in this reaction was qualitatively analyzed on ethidium bromide (EtBr) stained denaturing (FIG. 1A) and non-denaturing (FIG. 1B) polyacrylamide gels. These gels resolve the desired 29mer RNA product, but also reveal significant amounts of a “snapback” RNA product estimated to be about 45 to 49 nucleotides in length. [0076] Radiolabled RNA was generated by incorporating 33 P-ATP in the T7 RNA polymerase reaction, and annealed to an unlabeled ssDNA 49mer having the nucleotide sequence set forth in SEQ ID NO:2 (shown below). In an alternative version of these experiments, the complementary DNA oligonucleotide (SEQ ID NO:2) was radiolabeled with 33 P at the 5′ end by T4 PNK, and annealed to the unlabeled 29mer ssRNA (SEQ ID NO: 1). 5′-GACTAATACGACTCACTATAGGAAGAAAATATCATCTTTGGTGTTAACA-3′ (SEQ ID NO:A) 3′-CTGATTATGCTGAGTGATATCCTTCTTTTATAGTAGAAACCACAATTGT-5′ (SEQ ID NO:B) 5′-GGAAGAAAAUAUCAUCUUUGGUGUUAACA-3′ (SEQ ID NO:1) 5′-TGTTAACACCAAAGATGATATTTTCTTCCTATAGTGAGTCGTATTAGTC-3′ (SEQ ID NO:2) [0077] The quality of these radiolabeled RNA-DNA hybrid substrates was quantitatively evaluated on polyacrylamide gels. FIG. 2B shows the image of a non-denaturing gel loaded with the unlabeled RNA (SEQ ID NO: 1) annealed to 33 P-end labeled DNA (SEQ ID NO:2), whereas FIGS. 2C-2D show images of denaturing (FIG. 2C) and non-denaturing (FIG. 2D) gels loaded with radiolabeled RNA (SEQ ID NO: 1) annealed to unlabeled DNA (SEQ ID NO:2). Quantitative phosporimagery of the labeled RNA in denaturing gels (FIG. 2C) indicates that the contaminant “snapback” RNA represents approximately 35 to 40% of the total RNA. As expected, the “snapback” RNA species is not seen in the native (i.e., non-denaturing) gel (FIG. 2D), since separation of the RNA molecules in that gel is dependent upon both conformation and size of the different RNA species, whereas separation in the denaturing gel of FIG. 2C is independent of the native molecule's conformation. [0078] Results: [0079] Time dependent RNA degradation by RNase H. Aliquots containing 0.5 pmol of the radio-labeled DNA-RNA substrate (25 nM concentration) and 0.1 U of HIV reverse transcriptase (1.9 fmol at 0.095 pM concentration) were incubated in Tris buffer (pH 8) with 10 mM MgCl 2 , KCl (between 0 and 30 mM), 3% glycerol, 0.2% NP-40, 50 μg/ml BSA and 1 mM DTT. In a parallel experiment, aliquots containing 0.5 pmol of the labeled DNA-RNA substrate (25 nM concetration) were also incubated with 0.01 U of E. coli RNase H1 enzyme in Tris buffer (pH 7.5), containing 100 mM NaCl, 10 mM MgCl 2 , 3% glycerol, 0.02% NP-40 and 50 μg/ml BSA. The various aliquots were incubated at 37° C. for 0 (i.e., <30 seconds), 5, 10, 20, 30 40 and 60 minutes to allow for RNA degradation by the RNase H enzymes, after which time the reactions were quenched by the addition of an equal volume of 100 mM EDTA. The reaction products were analyzed by PAGE. [0080] The results are presented in FIGS. 3A-3B. In particular, FIG. 3A shows the image of a polyacrylamide gel run for a substrate of unlabeled RNA/end-labeled DNA digested with HIV RT RNase H (lanes 1-7) and E. coli RNase H1 (lanes 9-14). Lane 8 shows results from a control experiment where no enzyme was present (NE). As expected, the intensity of bands corresponding to the RNA-DNA hybrid decreases as aliquots are incubated for longer times, while the intensity of bands corresponding to labeled DNA alone increases. [0081] [0081]FIG. 3B shows the image of an identical polyacrylamide gel run for a labeled RNA/unlabeled DNA hybrid substrate digested with the 3U HIV RT RNase (66 fmol in 6.6 nM) with 50 mM HEPES (pH 8), 10 mM MgOAc, 0.02% NP40, 5 μg/μl BSA, 3% glycerol and 2 mM DTT. The cleavage products of the RNase enzyme are visible and are degraded in a similar rate dependent manner as in FIG. 3A. [0082] To investigate the assay's ability to distinguish different levels of RNase activity, additional experiments were performed using different concentrations of the HIV-RT enzyme and/or substrate. 150 nM of unlabeled RNA/end-labeled DNA hybrid substrate was incubated with either 0.3 or 0.1 U of HIV-RT enzyme under the conditions described, supra. [0083] Quantitative results from those experiments are shown in FIGS. 4 A-B. In particular, FIG. 4A shows the image of a polyacrylamide gel loaded with substrate that was digested with 0.3 U of HIV-RT enzyme, whereas FIG. 4B shows the image of a polyacrylamide gele loaded with substrate digested by 0.1 U of the HIV-RT enzyme. Quantitative plots of these data, showing the % of ssDNA observed as digestion progressed with time, are provided in FIGS. 5 A-B, respectively. As expected, the assay detected lower levels of digestion over identical periods of time when lower RNase enzyme concentration was used. [0084] HIV RT RNase H does not degrade ssRNA. Experiments were also performed to determine whether there may be any non-specific RNA degradation by the RNase H enzyme which might have effected the above discussed results. Here, 0.1 μM aliquots of radiolabeled ssRNA substrate were incubated with 1 U HIV RT RNase H enzyme under the conditions described for the previous experiments, supra, and the reaction products were run on denaturing polyacrylamide gels (FIG. 6A). As a control, identical ssRNA aliquots were incubated under the same condition but without RNase H, and these control aliquots were also run on denaturing gels (FIG. 6B). The amount of radiolabled RNA substrate detected is similar for each reaction time and smaller degradation products are not observed, indicating that ssRNA is not degraded by the RNase H enzyme. The extent of RNase H activity was monitored in a parallel experiment with an RNA-DNA hybrid substrate (FIG. 7C) and confirms that the enzyme used in these experiments was functional. [0085] Single stranded DNA and RNA contaminants do not affect RNase H activity. Experiments were also performed to determine whether ssRNA and/or ssDNA contaminants or reaction products might affect measurements of RNase H activity, e.g., by inhibiting that enzyme. First, aliquots containing 0.1 nM (5 pmol) of the RNA-DNA hybrid substrate and 1 U (2.2 ng or 3 fmol) of the HIV RT enzyme were incubated with 5, 10 and 50 pmol of either homopolymeric polyA (SEQ ID NO:3) or polyU (SEQ ID NO:4) or heteropolymeric (18S) RNA (SEQ ID NO:5), so that the molar ratios to RNA-DNA hybrid substrate were 1:1, 2:1 and 10:1, respectively. homopolymeric polyA 5′-(A) n -3′ (n ≈ 500 to 1000) (SEQ ID NO:3) homopolymeric polyU 5′-(U) n -3′ (n ≈ 500 to 1000) (SEQ ID NO:4) 18S RNA 5′-CCCUCUCUCUCUCUUAAUGGGAGUGAUUUCCCUCCUCUU (SEQ ID NO:5) CGAAUAGGGUUCUAGGUUGAUGCUCGAAAAAUUGACGUCG UUGAAAUUAUAUGCGAUAACCUCGACCUUAAAGGCGCCGAC GACAAG-3′ [0086] Each aliquot was incubated at 37° C. and the reaction products were run on polyacrylamide gels (FIG. 7). Titration of the sample with 125-mer 18S RNA, which contains significant secondary structure, did inhibit HIV RT RNase H in a dose dependent manner, as determined by the measured amount of end-labeled ssDNA after each reaction. However, such contaminants are unlikely to be present in any “real” RNase H assay. The homopolymeric U and A, which do not exhibit any secondary structure, did not inhibit HIV RT RNase H activity. [0087] Similar experiments were also performed aliquots containing 0.1 μM (5 pmol) of the RNA-DNA hybrid substrate and 1 U (2.2 ng or 19 fmol) of HIV RT enzyme were incubated with one of single stranded DNA oligonucleotides set forth in Table I, below. These oligonucleotides, which are referred to here as Oligo 1, Oligo 2 and Oligo 3 are also identified by SEQ ID NOS:6-8, respecitvely. The molar ratio of each ssDNA oligomer to substrate in the different aliquots was 1:1, 2:1 and 10:1 (i.e., 5, 10 and 50 pmol). Again, the aliquots were incubated at 37° C. to permit RNA degradation by the RNase H, and then quenched after 30 minutes and analyzed by PAGE (FIG. 8) The results indicate the HIV RT RNase H activity is not inhibited by ssDNA. Thus, the presence of single-stranded RNA or ssDNA in the assay (generated, e.g., as a consequences of enzyme activity) will only minimally effect the assessment of RNase activity, if at all. TABLE I Deoxyoligonucleotide Sequences Titrated with RNase H Substrate Oligo 1 (SEQ ID NO:6) 5′-GTGAGGGTAATTCTCTCTCTCTCCCAAACCCCAAA-3′ Oligo 2 (SEQ ID NO:7) 5′-ATCTTGGGATAAGCTTCTCCTCCC-3′ Oligo 3 (SEQ ID NO:8) 5′-TTGCTGCAGTTAAAAAGCTCGTAG-3′ [0088] RNA degradation requires competent RNase H activity. To confirm that the RNA degradation observed in these experiments is actually due to RNase H and not some other activity of the RT holoenzyme, assays were performed using RT enzyme from different sources. Specifically 0.1 μM (5 pmol) of the RNA-DNA substrate was incubated with either 1 U of the HIV RT enzyme (2.2 ng or 19 fmol), 1 U of MMLV RT enzyme (10 ng or 15 fmol) obtained from Promega (Madison, Wis.). An identical experiment was also performed using an equivalent amount of a mutant MMLV RT enzyme that has been previously described and characterized as having no RNase H activity (Roth et al., J. Biol. Chem. 1985, 260:9326; Tanese et al., Proc. Natl. Acad. Sci. U.S.A. 1988, 85:1977). [0089] Aliquots of each sample were incubated at 37° C. for <30 seconds, 10, 20, 30 and 60 minutes, after which time the reaction was quenched and reaction products were analyzed by PAGE as described, supra, in the previous experiments. The results from the experiments are shown in FIG. 9A (HIV RNase H), FIG. 9B (MMLV RNase H) and FIG. 9C (MMLV RNase H-mutant). The amount of substrate remaining in each aliquot after the reaction was quantitatively determined by volume analysis following the phosphorimagry, using the formula: % substrate remaining=((substrate)/(substrate+product))×100% [0090] The results from this quantitative analysis are plotted in FIG. 9D, and confirm that the apparent degradation of RNA from RNA-DNA hybrids observed in these assays is the result of a functional RNase H activity. Example 2 Real Time Assay for RNase H Activity [0091] This example demonstrates particular embodiments of a preferred assay that is capable of detecting and monitoring RNase H activity in real time. The exemplary assay uses an RNA-DNA hybrid substrate that comprises a fluorophor moiety and a quencher moiety. The fluorophor moiety comprises a moiety that is capable of emitting a fluorescent or other detectable signal. The quencher moiety, by contrast, comprises a moiety that is capable of absorbing the signal generated by the fluorophor moiety. [0092] For instance, in the exemplary embodiment described here the fluorophor moiety is fluorescein and the quencher moiety is dabcyl, both of which are commercially available, e.g., from Stratagene (La Jolla, Calif.). However, the precise identity of the fluorescent and quencher moieties is not critical and a variety of such moieties which can be used for the present invention are commercially available and/or generally known in the art. Examples of other common fluorophors that can be used include but are not limited to Cy3, Cy3.5, Cy5 and Cy5.5 (available from Amersham Biosciences Corp., Piscataway N.J.) as well as Texas red, fluoroscein, 6-FAM, HEX, TET, TAMRA, Rhodamine Red, Rhodamine Green, Carboxyrhodamine, BODIPY, 6-SOE, Coumarin and Oregon Green, all of which are commercially available, e.g., from Molecular Probes (Eurgene, Oreg.) or Sigma-Aldrich Corp. (St. Louis, Mo.). Exemplary quencher moieties include DABCYL (available from Sigma-Aldrich Corp., St. Louis Mo. or from Molecular Probes, Eugene Oreg.) as well as Black Hole Quenchers (“BSQs”, available from Biosearch Technologies, Inc., Novato Calif.) such as BHQ-1, BHQ-2 and BHQ-3. [0093] An exemplary embodiment of a DNA-RNA hybrid substrate which may be used in such an assay is schematically illustrated in FIG. 10A. In this example, the DNA substrate comprises the nucleotide sequence set forth in SEQ ID NO:9, whereas the RNA substrate comprises the nucleotide sequence set forth in SEQ ID NO: 10. Those skilled in the art will appreciate that the exact sequence of the DNA-RNA substrate is not critical for practicing the invention. However, the sequences will preferably have certain properties. In particular, the sequence of the DNA substrate preferably comprises a 5′-region and a 3′-region, which are located at deoxyoligonucleotide's 5′- and 3′-ends, respectively. Preferably, the 5′-region and 3′-region are complementary and capable of hybridizing to each other under assay conditions. The DNA substrate also preferably comprises a center region that is complementary to at least a part of the RNA substrate so that the DNA substrate and RNA substrate are capable of hybridizing to each other under assay conditions, thereby forming the DNA-RNA hybrid substrate. For illustrative purposes, the exemplary DNA substrate is illustrated in FIG. 10A as having the fluorophor moiety attached to the 3′-region (e.g., on the 3′-end of the deoxyoligonucleotide) and having the quencher moiety attached to the 5′-region (e.g., on the 5′-end of the deoxyoligonucleotide). However, embodiments in which the quencher moiety is attached to the 3′-region (e.g., on the 3′-end of the deoxyoligonucleotide) and the fluorophor moiety is attached to the 5′-region (e.g., on the 5′-end of the deoxyoligonucleotide) are also contemplated and generally will be equally preferred. [0094] Without being limited to any particular theory or mechanism of action, it is believed that as RNase H degrades RNA in the RNA-DNA hybrid substrate, the 5′- and 3′-regions of the DNA anneal to each other so that the oligonucleotide probe adopts a conformation such as that illustrated in FIG. 10B, placing the fluorophor moiety and the quencher moiety in sufficient proximity so that the quencher moiety absorbs at least part of the detectable signal emitted by the fluorophor moiety. Consequently, RNase H activity may be detected and monitored by detecting an attenuation or decrease in fluorescence (FIG. 10C). [0095] To demonstrate its efficacy, both HIV RT RNase H and E. coli RNase H1 were examined using this assay format. RNase H enzymes and RNA substrate (SEQ ID NO: 10) were prepared as described in Example 1, above. A DNA oligonucleotide probe (SEQ ID NO:9) was also prepared according to routine methods and labeled on the 3′-end with fluorecein and with dabcyl on the 5′-end, both of which are available from Stratagene (La Jolla, Calif.). [0096] In a first set of experiments, an oligonucleotide probe (SEQ ID NO:9) labeled with the fluorophor Texas red and a DABCYL quencher moiety was annealed to RNA (SEQ ID NO: 10) at molar ratios of 1:1 and 1:2 (DNA:RNA). Each assay was carried out at 25° C. in a final volume of 25 μl of 50 mM Tris buffer (pH 8) with 10 mM MgCl 2 , optional KCl (0 to 30 mM), 3% glycerol, 1 mM DTT, 0.02% NP-40 and 50 μg/ml BSA containing substrate and inhibitor at the indicated quantities or concentrations. Substrate hydrolysis was monitored during the reaction as a function of time using a Wallac Victor fluorescence microplate reader (Perkin Elmer Life Sciences, Inc., Boston Mass.) with excitation and emission wavelengths set with filters at 585 and 615 nm, respectively, and with a 10 nm band pass. The substrate was added to the enzyme sample to initiate the reaction. Instrument data collection was monitored with a personal computer compatible with 32-bit Windows Workstation software, designed to utilize the full capabilities of Windows™ 95/98/NT. Fluorescent measurements were taken every 30 seconds and are plotted in FIG. 11A. A similar set of experiments were also performed in which 0.1 μM and 0.3 μM of the DNA-RNA substrate were incubated with 0.0003 and 0.001 U of E. coli RNase H1 in 50 mM Tris buffer (pH 7.5) containing 100 mM NaCl, 10 mM MgCl2, 3% glycerol, 0.02% NP40, 50 μg/ml BSA. The fluorescent signal measured in these samples is plotted as a function of real time in FIG. 11B. [0097] These data show that the above-described assay format is robust and effective. A decrease in the fluorescence signal is observed that is a function of both the incubation time and enzyme concentration, and is consistent with the rate of RNA degradation by the enzyme. REFERENCES CITED [0098] Numerous references, including patents, patent applications and various publications, are cited and discussed in the description of this invention. The citation and/or discussion of such references is provided merely to clarify the description of the present invention and is not an admission that any such reference is “prior art” to the invention described herein. All references cited and discussed in this specification are incorporated herein by reference in their entirety and to the same extent as if each reference was individually incorporated by reference. 1 8 1 29 RNA Artificial Sequence synthetic RNA 1 ggaagaaaau aucaucuuug guguuaaca 29 2 49 DNA Artificial Sequence synthetic DNA 2 tgttaacacc aaagatgata ttttcttcct atagtgagtc gtattagtc 49 3 126 RNA Artificial Sequence synthetic RNA 3 cccucucucu cucuuaaugg gagugauuuc ccuccucuuc gaauaggguu cuagguugau 60 gcucgaaaaa uugacgucgu ugaaauuaua ugcgauaacc ucgaccuuaa aggcgccgac 120 gacaag 126 4 35 DNA Artificial Sequence oligonucleotide 4 gtgagggtaa ttctctctct ctcccaaacc ccaaa 35 5 24 DNA Artificial Sequence oligonucleotide 5 atcttgggat aagcttctcc tccc 24 6 24 DNA Artificial Sequence oligonucleotide 6 ttgctgcagt taaaaagctc gtag 24 7 33 DNA Artificial Sequence oligonucleotide 7 acgagcaaca ccaaagatga tattttcgct cgc 33 8 49 DNA Artificial Sequence oligomer 8 gactaatacg actcactata ggaagaaaat atcatctttg gtgttaaca 49

The present invention provides a method of detecting a nuclease-mediated cleavage of a target nucleic acid through hybridizing a target nucleic acid to a fluorescently labeled oligonucleotide probe complementary to the target nucleic acid and containing a flourophor at one terminus and a quenching group at the other terminus. When the probe is unhybridized to the target nucleic acid, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor. Once hybrized, the method contacts the probe-target hybrid with an agent having nuclease activity in an amount sufficient to selectively cleave the target nucleic acid and thereby release the intact probe. Detecting the release of the probe is then measured by following a decrease in the flourescent signal of the flourophor as compared to the signal of the probe-target hybrid.

This Appln is a 371 of PCT/U.S. 97/06762 filed May 16, 1997 which claims benefit of Prov. No. 60/017,133 filed May 17, 1996. FIELD OF THE INVENTION The present invention relates to devices and methods for obtaining samples of blood and other fluids from the body for analysis or processing. BACKGROUND OF THE INVENTION Many medical procedures in use today require a relatively small sample of blood, in the range of 5-50 μL. It is more cost effective and less traumatic to the patient to obtain such a sample by lancing or piercing the skin at a selected location, such as the finger, to enable the collection of 1 or 2 drops of blood, than by using a phlebotomist to draw a tube of venous blood. With the advent of home use tests such as self monitoring of blood glucose, there is a requirement for a simple procedure which can be performed in any setting by a person needing to test. Lancets in conventional use generally have a rigid body and a sterile needle which protrudes from one end. The lancet may be used to pierce the skin, thereby enabling the collection of a blood sample from the opening created. The blood is transferred to a test device or collection device. Blood is most commonly taken from the fingertips, where the supply is generally excellent. However, the nerve density in this region causes significant pain in many patients. Sampling of alternate site, such as earlobes and limbs, is sometimes practiced to access sites which are less sensitive. These sites are also less likely to provide excellent blood samples and make blood transfer directly to test devices difficult. Repeated lancing in limited surface areas (such as fingertips) results in callous formation. This leads to increased difficulty in drawing blood and increased pain. To reduce the anxiety of piercing the skin and the associated pain, many spring loaded devices have been developed. The following two patents are representative of the devices which were developed in the 1980s for use with home diagnostic test products. U.S. Pat. No. 4,503,856, Cornell et al., describes a spring loaded lancet injector. The reusable device interfaces with a disposable lancet. The lancet holder may be latched in a retracted position. When the user contacts a release, a spring causes the lancet to pierce the skin at high speed and then retract. The speed is important to reduce the pain associated with the puncture. U.S. Pat. No. 4,517,978, Levin et al., describes a blood sampling instrument. This device, which is also spring loaded, uses a standard disposable lancet. The design enables easy and accurate positioning against a fingertip so the impact site can be readily determined. After the lancet pierces the skin, a bounce back spring retracts the lancet to a safe position within the device. In institutional settings, it is often desirable to collect the sample from the patient and then introduce the sample to a test device in a controlled fashion. Some blood glucose monitoring systems, for example, require that the blood sample be applied to a test device which is in contact with a test instrument. In such situations, bringing the finger of a patient directly to the test device poses some risk of contamination from blood of a previous patient. With such systems, particularly in hospital settings, it is common to lance a patient, collect a sample in a micropipette via capillary action and then deliver the sample from the pipette to the test device. U.S. Pat. No. 4,920,977, Haynes, describes a blood collection assembly with lancet and microcollection tube. This device incorporates a lancet and collection container in a single device. The lancing and collecting are two separate activities, but the device is a convenient single disposable unit for situations when sample collection prior to use is desirable. Similar devices are disclosed in Sarrine, U.S. Pat. No. 4,360,016, and O'Brien, U.S. Pat. No. 4,9249,879. U.S. Pat. Nos. 4,850,973 and 4,858,607, Jordan et al., disclose a combination device which may be alternatively used as a syringe-type injection device and a lancing device with disposable solid needle lancet, depending on configuration. U.S. Pat. No. 5,318,584, Lange et al., describes a blood lancet device for withdrawing blood for diagnostic purposes. This invention uses a rotary/sliding transmission system to reduce the pain of lancing. The puncture depth is easily and precisely adjustable by the user. Suzuki et al., U.S. Pat. No. 5,368,047, Dombrowski, U.S. Pat. No. 4,654,513 and Ishibashi et al., U.S. Pat. No. 5,320,607, all describe suction-type blood samplers. These devices develop suction between the lancing site and the end of the device when the lancet holding mechanism withdraws after piercing the skin. A flexible gasket around the end of the device helps seal the end around the puncture site until adequate sample is drawn from the puncture site or the user pulls back on the device. U.S. Pat. No. 4,637,403, Garcia et al. and U.S. Pat. No. 5,217,480, Haber et al, disclose combination lancing and blood collection devices which use a diaphragm to create a vacuum over the wound site. International Application Publication Number WO 95/10223, Erickson et al, describes a means of collecting and measuring body fluids. This system uses a disposable lancing and suction device with a spacer member which compresses the skin around the lance/needle. Single use devices have also been developed for single use tests, i.e. home cholesterol testing, and for institutional use to eliminate cross-patient contamination multi-patient use. Crossman et al, U.S. Pat. No. 4,869,249, and Swierczek, U.S. Pat. No. 5,402,798, also disclose disposable, single use lancing devices. Even with the many improvements which have been made, the pain associated with lancing remains a significant issue for many patients. The need for blood sampling and the fear of the associated pain is also a major obstacle for the millions of diagnosed diabetics, who do not adequately monitor their blood glucose due to the pain involved. Moreover, lancing to obtain a blood sample for other diagnostic applications is becoming more commonplace, and a less painful, minimally invasive device is needed to enhance those applications and make those technologies more acceptable. An object of the present invention is to provide a device and a method for obtaining a sample of bodily fluid through the skin which is virtually pain free and minimally invasive. Another object of this invention is to provide a method which can result in a sample of either blood or interstitial fluid, depending on the sample site and the penetration depth utilized. While there are no commercially available devices utilizing interstitial fluid (ISF) at this time, there are active efforts to establish the correlation of analytes, such as glucose, in ISF compared to whole blood. If ISF could be readily obtained and correlation is established, ISF may be preferable as a sample since there is no interference of red blood cells or hematocrit adjustment required. Another object of this invention is to provide a method which can draw a small but adjustable sample. i.e. 3 μL for one test device and 8 μL for another test device, as appropriate. Another object of this invention is to provide a method by which the drawn sample is collected and may be easily presented to a testing device, regardless of the location of the sample site on the body. This approach helps with infection control in that multiple patients are not brought in contact with a single test instrument; only the sampling device with a disposable patient-contact portion is brought to the test instrument. Alternatively, the disposable portion of a test device may be physically coupled with the sampler so the sample can be brought directly into the test device during sampling. The test device may then be read in a test instrument if appropriate or the testing system can be integrated into the sampler and the test device can provide direct results displayed for the patient. It is a further object of the invention is to provide a device for minimally invasive sampling comprising a reusable sampler and disposable sample collection. SUMMARY OF THE INVENTION In one aspect, the present invention relates to a device which uses mechanical motion to pierce the skin, and a mechanical kneading or oscillation to produce a sample of fluid from the body and may employ a back pressure or vacuum to collect a small fluid sample into the device. More specifically, the present invention comprises a reusable sampling device and a disposable piercing/collecting apparatus. The device may also employ a back pressure, capillary or vacuum to collect a small fluid sample into the piercing/collecting apparatus that may later be discharged to deliver the collected sample to a test device or other appropriate vessel. The system may alternately be used to deliver the sample to an integral disposable test device, without collecting and separately dispensing the body fluid sample. A method aspect of this invention involves piercing of the skin at a rapid rate (to minimize pain), with a needle (which minimizes the trauma and pressure-associated pain response which occurs with a traditional lancet). The skin is kept taut during the lancing to allow accurate and repeatable penetration of the needle into the skin. After piercing the skin, the needle is withdrawn from the wound and the surrounding area kneaded by ultrasonic action, piezoelectric or mechanical oscillation or squeegee motion to stimulate the blood flow into and from the wound. Additionally heat, electrical potential or friction can be used to stimulate additional flow of the body fluid. This fluid or blood flow can also be stimulated by ultrasonic vibration of the skin surrounding the wound. In an alternate embodiment to stimulate blood flow, the needle remains in the wound for a period of time, with either slow mechanical vibration or rotation of the needle, ultrasonic, or piezoelectric oscillation of the needle, to keep the wound open for blood to pool. After the area has been stimulated and the blood wells up in the wound, a capillary, syringe or pumping system is used to draw microliter samples from the patient. Suction is applied to the needle or the suction tube through either peristalsis, convection (application of heat to a capillary tube) or by the piston of a small microsyringe. The piston is pulled back into the sampler device with spring action, generating a vacuum in the barrel of the microsyringe and quickly drawing fluid from the body through the needle or the suction tube into the barrel to normalize the pressure differential. The piston or suction device then can be reversed to dispense the collected sample. The system can also use a capillary tube which is used to draw the sample after it has been collected on the skin surface. The capillary tube can then dispense the sample to a desired test or analysis device by applying pressure through the tube or simply contacting the end of the tube and the sample with a surface or material that has sufficient affinity for the fluid to pull the sample from the tube. The above method and system may be used on various parts of the body. It is particularly appropriate for use on sites other than the fingertips. Although fingertips provide good blood flow, the high density of pain receptors provide for easy access to blood but maximum pain in sampling. The method of this invention actively draws a sample from the body, enabling the use of sampling sites on the body which are inadequate for traditional lancing. Since the method can also provide a mechanism for the easy transfer of the sample, the difficulty of bringing the sample to a test device is eliminated. An important benefit of this system is that the use of alternate sites on the body reduces the accompanying pain sensation and encourages more frequent use as needed. While the method may be readily used to obtain a blood sample in a minimally invasive fashion, a sample of interstitial fluid may similarly be obtained, generally utilizing a less deep puncture in sites with lower blood flow. This will become more important as tests are developed which can utilize ISF samples, which may be preferred compared to blood. This invention provides a device and method for lancing a patient and virtually simultaneously producing and collecting the fluid sample, which may be transferred to a test device. A preferred device of the present invention comprises a blood collection system including a lancing needle, drive mechanism, kneading or vibration mechanism and optional suction system and sample ejection mechanism. The device is preferably sized to be hand-held in one hand and operable with one hand. The device can optionally contain integral testing or analysis component for receiving the sample and providing testing or analysis indication or readout for the user. The lancing needle and firing mechanism designed to create a wound which will both provide an adequate sample but which will still close and heal quickly Wound healing is an especially important consideration for diabetic patients who often have compromised circulatory systems and slow healing processes. The wound must have a geometry which allows for a momentary space in which blood can fill, taking into account the elastic nature of the skin tissues. Careful consideration must be given to these geometries or the dermis will seal around the lancing needle tip, precluding the drawing of a sample through the tip. In a preferred embodiment a needle is used in combination with a flexible collar and outer tube to spread the wound so blood can pool. Alternatively a multiple needle lancing device can be used to generate a wound which disrupts multiple capillary areas to quickly provide large sample size, but the smaller multiple wounds, can heal more easily. In an alternate embodiment, the needle/lance is withdrawn from the wound, and the area surrounding the wound is massaged or stimulated to prevent it from closing and to promote the flow of body fluids and or blood to the wound and to the surface of the skin. Devices according to this invention create a lancing motion which cuts into the small but plentiful capillaries in the superficial vascular plexus under the epidermis. This vascularized region starts at a depth of 0.3-0.6 mm from the surface of the skin in many accessible areas throughout the body (forearm, thigh, abdomen, palm. Blood is in plentiful supply in this region of the skin, and healing of small wounds is not problematic. However, bringing a sizable drop of blood to the surface is more problematic than with a finger stick. A finger stick is typically massaged to increase momentary blood flow. This invention provides a system for mechanically massaging a lance site at other body locations by several different approaches, including oscillating an annular ring surrounding the wound to pump the blood surrounding the wound into the wound for extraction by a needle or capillary tube or oscillating paddles or other members adjacent the wound to achieve the desired blood flow. Further, bringing a drop of blood from the skin in other regions of the body, e.a., the thigh, to a small area on a test device is very difficult. An alternate embodiment of the present invention works with the needle remaining in the wound and the needle being mechanically manipulated to promote the formation of a sample of body fluid in the wound. The needle may be vibrated in any desired and effective motion, including an up and down motion, a side to side motion, a circular motion, a rotation motion or any combination thereof. This creates a momentary opening in which the blood can fill while the device draws the blood through the needle into the disposable sample collection chamber. The vibration of the needle may occur across a broad range, from 30 cycles per minute up to 1000 cycles per minute or more. This slight vibration does not measurably increase the sensation felt by the patient, particularly when a short duration time is used, but does markedly increase the sample volume which may be easily withdrawn from a given wound and the rate at which the sample volume is produced from the wound. The oscillation can cause the needle to move up to 2-3 mm per cycle. The optimal needle oscillation is less than 1.5 mm, with about 0.5 mm preferred based on current investigations. Oscillating or rotating the needle from 30 cycles per minute up to 1000 cycles per minute or more holds the wound open and prevents it from closing and stopping sample collection and provides sample collection in a shorter amount of time. Lancing conventionally occurs at a 90 degree angle (perpendicular) to the skin surface. However, we have found that the lancing member may puncture significantly more capillaries if the lancing is performed on a angle. At a too shallow angle, no significant depth of penetration is achieved. Lancing at an incident angle of 15-90 degrees to the surface of the skin is effective, with shallower angles producing greater blood flow. The device and system of this invention can further enhance blood flow by massaging the site prior to lancing, as well as by massaging the area adjacent the lancing cite while the lancing member is in the wound and after it is removed from the wound, as well as during sample collection, as described above. Alternate methods can use a wiper to rub across or vibrate the skin or can apply heat to the skin to increase the blood flow to the sampling site. In another alternate configuration, the lancing needle may be withdrawn very slightly from the point of maximum penetration to create an opening in which blood can pool before being suctioned through the device. This can be accomplished with a double stop system which stops the needle at maximum penetration then stops the retraction of the needle at partial but not full retraction. The area surrounding the wound can be kneaded or massaged by optional movable members mechanical to stimulate blood flow to the wound and increase the sample size and the rate of production of the sample. The mechanical motion can displace the area around the wound from 0.05 to 8 mm, with 1-5 mm being preferred based on current investigations. A wiper device can be used in the aspect which rubs the skin to increase the blood flow to the wound by stimulating the capillaries. The mechanical stimulation of the wound can be accomplished by different methods or motions and members. An annular ring or other polygon or blade or paddle members may be oscillated around the wound by piezoelectric, ultrasonic, solenoid/coil, motor and cam or other methods apparent to one skilled in the art. Mechanical oscillation in the range of 2 to 1000 cycles per minute may be employed, with 10 to 400 cycles being preferred. Ultrasonic vibration has been effective at a frequency as high as 40 kHz. Alternately, the device may employ a blade or squeegee type of stimulator which kneads the site with horizontal or a combination of horizontal and vertical action and promotes blood flow to the wound. The squeegee may act on the wound area 2 to 200 times per minute, with 60 times per minute preferred based on current investigations. Additionally, the needle may be vibrated ultrasonically, with or without the kneading or massaging action adjacent the wound. The ultrasonic vibration can cover the range of ultrasonic frequencies depending on the sampling area and whether the needle or the stimulation device is being activated. In another aspect of this invention the lancing member is contained a multi-chambered or multi-channelled capillary disposable member wherein one chamber contains the lancing member and an adjacent chamber is adapted to receive the blood or fluid exiting the wound. The multi-chambered capillary disposable can be made from any suitable material, and installed in the sampler so that it is positioned in the appropriate position relative to the wound created to permit collection of the sample. The lancing device is driven into the skin and withdrawn by the secondary retraction springs after reaching the limit stops. After withdrawal of the lancing member, the stimulator ring or other polygon shape is oscillated by one of the various methods to pump blood from the capillaries adjacent to the wound. The sampling device of this aspect of the invention has stop mechanisms to limit the penetration of the lancing member and sample duration system which sets the time of the sample collection. The lancing guide chamber can be formed a variety of ways and one skilled in the art can reconfigure it to create alternate embodiments. In another aspect similar to the above, the lancing member can be contained within a single capillary tube and adapted to extend from the end of the tube to create the wound. The lancing member then retracts a sufficient distance inside the capillary to allow the desired sample to be collection in the end of the same capillary tube in the space below the retracted lancing member. In such an embodiment the lancing member can be vibrated in the wound before retraction, also as described above. To achieve the sample collection after withdrawing the needle, a stimulator ring can be used to pump the sample from the surrounding capillaries through the wound opening. The stimulator ring is designed to keep the skin taut to allow better penetration of the skin during lancing and help keep the wound open during pumping. It can be oscillated appropriately to insure that enough sample is pumped from the local capillaries. The time or number of cycles varies by individual and location being sampled. To achieve a variable sample time either of the following methods may be used. A sensor can be built into the sampler which senses the blood in the collection chamber or device. When an adequate sample level (which may be adjustable) is reached, the stimulation mechanism is turned off. A second method is to have a patient definable input which sets the time duration for the test or the number of cycles for the stimulation ring. Additional stimulator motions can be employed to promote the extraction of bodily fluids. These include sinusoidal motion, wobbling, kneading or peristaltic motion. An alternate stimulator device can be designed with an inner and outer ring which will alternate creating a peristaltic pumping motion on the capillaries surrounding the wound. Another alternate stimulator device uses a spiral spring that can be compressed flat to emulate multiple pumping rings. As will be apparent, various configurations of multiple stimulator rings, paddles, or other members, used in various rhythms and orders of movement can be employed in the present invention. The stimulator ring or member can be heated in order to heat the skin to increase the capillary volume flow to and out of the wound. In addition, the housing or case of the device or other components of the device can be heated to provide heating of the skin. In another aspect of the invention a diffused laser may be used to penetrated to the superficial vascular plexus and a capillary tube may be used to collect the sample. A lens may be used to diffuse the laser so that it does not create a large wound or damage large areas of skin and tissue. A minimum wound size is important to enable rapid healing. The capillary collection tube can use a suction generator to draw the sample up the tube and can also utilize an optional stimulator ring to pump the blood from the adjacent capillary beds. In another aspect of the invention the lancing can be accomplished by a pulse of a fluid under high pressure such as a liquid or a compressed gas. In addition the compressed gas can be directed, at lower pressure, to the skin surface to massage the skin before lancing, during lancing and/or during sample collection. Pulsing the compressed gas against the skin at desired pressures, patterns and intervals, including sequential pattern across the surface of the skin, can provide the desired stimulation of the blood flow into and from the wound. The pulse of compressed gas used to perform the lancing and opening of the wound can be a single pulse or multiple pulses, can be directed through a capillary sample collection tube, and/or can be applied vertically to the skin surface or at an angle, as described above for other lancing members, to achieve puncturing the maximum capillaries in the skin and provide the sample collection in a short period of time. In another aspect of the invention an off meter test device is used with a sampler of this invention to provide an integrated sampling and testing device. This device can be used by the patient to essentially simultaneously draw a sample and test for the presence or concentration of an analyte in a body fluid. The sample can be taken from an alternate location other than the fingertips with the device of this invention. To accomplish this it is critical to the test to provide a mechanism to stimulate the wound and or the surrounding area to provide an adequate sample for the test device. This stimulation can be accomplished by manipulating the needle or the area of skin surrounding the wound as described above. A combination of the two methods can be employed to increase the volume and/or decrease the sampling time. The sample is introduced directly into a test device or testing area rather than being collected and subsequently dispensed. In another aspect, this invention also provides a method of determining the correct sample size prior to transferring or testing. Different methods can be used to sense the volume and/or presence of the sample. One system uses two contacts to sense the presence and/or volume of a sample. The body fluid either is drawn up a tube or wells up on the surface of the skin where it creates a short between two contacts which signal that the proper sample has been drawn. An alternate system uses an LED and receiver. When the sample rises to the level where it blocks the LED from the receiver the proper sample has been drawn. Other optically activated or contact activated systems can be used in this aspect of the invention. In another aspect, this invention also provides a method of making a unit with a disposable section to limit biohazard cross contamination. In another aspect, this invention provides a bell shape capillary tube. The capillary tube wicks the sample up the tube until it reaches the transition of the bulb. The bulb is then depressed to expel the sample or a known volume of the sample to a desired location, such as a test strip or device for analysis. The bell shape can be designed as a cone and the sample is wicked up the cone and dispensed by reversing the cone and expelling the sample by capillary action onto the test device. In an alternate embodiment the device of this invention lances and stimulates the area, creating a drop of sample fluid, which is collected on or transferred directly to a test device by applying the test device to the drop. In another aspect, this invention can also include an auto-injection device. A preloaded tip may be placed into the barrel. The trigger and spring system can be designed to deliver the sample from the syringe rather than to collect a sample into the syringe. One who is skilled in the art could readily reconfigure the mechanism described to inject a sample. Moreover, the device may have dual function of collecting a sample while simultaneously or sequentially injecting a sample, which can be in response to a test performed in the device on the sample collected. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows a device of this invention having a double stop mechanism. FIG. 2 A and FIG. 2B are cross section views of a device of this invention in the cocked and the deployed position, respectively. FIG. 3 shows a longitudinal cross section of a device according to this invention having a stimulator member proximate to the lancet or needle. FIG. 4 shows the stimulator member positioned on the skin of the patient adjacent the wound and the lance. FIG. 4A provides a schematic layout of the skin illustrating where the superficial vascular plexus capillaries are relative to the skin's surface. FIG. 4B is a representation of a wound, shown in cross section, which will facilitate the formation of a small pool of blood yet ensure that the skin will fully contract around the wound following sampling to promote healing. The relationship of the wound, needle and the superficial vascular plexus capillaries is also illustrated. In the embodiment shown the capillary is offset in the needle. FIGS. 4C and 4D show alternative embodiments in which, to enhance sample collection and minimize the wound size required, the needle may be vibrated mechanically in either an up and down motion as shown in FIG. 4C or a side to side as shown in FIG. 4 D. FIG. 4E shows that the needle may be vibrated ultrasonically with or without the kneading or massaging action. FIGS. 4F and 4G show that the area surrounding the wound can be kneaded by optional mechanical motion to stimulate blood flow to the wound and increase the sample size and the rate of production of the sample. FIG. 4H shows that, alternately, the device may employ a squeegee type of stimulator which kneads the site with horizontal or a combination of horizontal and vertical action and promotes blood flow to the wound. FIG. 4I shows an alternate embodiment in which needle is oscillated or rotated. FIGS. 5A and 5B show front and side views of a replaceable needle with a spade tip design adapted for use in this invention, especially for a moving/rotating needle for holding a wound open during sample collection. FIGS. 6A and 6B illustrate a front and side view of a disposable needle that has an eccentric passageway for sample collection. The needle can have a luer lock type connection to the sample device of this invention. FIG. 7 shows a needle with a collar or sleeve to provide mechanical spreading of the wound during sample collection. FIGS. 8A and 8B are longitudinal cross section views of a device with a multi-chambered capillary members accommodating a lancet or needle in one chamber and providing another chamber or conduit for sample collection. FIGS. 8C, 8 D and 8 E are top view cross section views of two and three chamber capillary members. FIGS. 9A and 9B illustrate a longitudinal cross section of a device having a multi-chambered capillary disposable and peristaltic pump to collect a sample. FIG. 9C illustrates in cross section an alternate suction/standoff/lance disposable tip containing contacts for electrically sensing the presence and/or volume of body fluid. FIG. 10 illustrates in cross section a device with a laser positioned to radiate through the interior of the needle or capillary for piercing the skin. FIG. 11 illustrates in longitudinal cross section in cross section a device of this invention for use with a combined suction/standoff chamber as part of a disposable sample collection system. FIGS. 12A and 12B illustrate a longitudinal cross section and side view cross section of a device of this invention having and angled lancet or needle and employing an absorbent strip. FIGS. 13 and 14 show a longitudinal cross section and a side view cross section of a sampling device of the present invention with an integrated calorimetric instrument test. FIG. 15 shows a longitudinal cross section of an sampling device of the present invention with an integrated electrochemical test. FIGS. 16 and 17 show a longitudinal cross section and a side view cross section of a sampling device of the present invention with an integrated colorimetric visual test. FIG. 18 shows an alternate device which has a completely disposable lower section to minimize blood contamination between uses. FIG. 19A shows the combination of a dual alternating stimulation ring system. FIG. 19B shows the device with a telescoping stimulator ring. FIGS. 20A, 20 B and 20 C illustrate a bell shape capillary tube and 20 D shows a straight capillary tube with a test strip. FIG. 21 illustrates a device of this invention with a member to oscillate the needle to stimulate fluid flow from the wound. FIG. 22A shows a multiple needle lancing device. FIG. 22B shows a broader single lancet. FIGS. 22C and 22D show a die cut sheet which has small multiple barbs formed in the sheet for use as a lance in the present invention. DESCRIPTION OF THE INVENTION FIG. 1 illustrates a minimally invasive sampling device according to the invention. The device is comprised of numerous components which will be more fully described below. The main body 1 supports the various mechanical components housed within the device. The main body 1 comprises an elongated hollow cylindrical tube with openings at both ends. The sampling needle 16 which is part of the disposable 3 which is capable of being retracted or deployed so that it can protrude beyond the needle guard 17 is positioned at one end. The arming and dispensing plunger 22 protrudes from the other end. The device has a needle guard 17 which permits the loading of the disposable 3 . Disposable 3 is attached to the syringe 13 and plunder 14 is released by the suction cam 8 . The syringe 13 is captivated to the drive system by syringe clamp 12 which has the main tie rods 4 anchored to it. The main drive springs 11 are captivated between the syringe clamp 12 and cross support 10 and the tie rods 4 are threaded through them. The main tie rods 4 have the main cams 9 attached to them and are supported by the activation trigger 2 prior to release. The secondary springs 21 and secondary stops 20 provide a mechanism after activation to pull the needle back out of the wound to permit blood accumulation. When the skin is pierced the secondary springs 20 retract the needle from the wound triggering the suction cam 8 and plunger 14 is released. The arming and dispensing plunger 22 is a dual purpose device. When the patient pulls up, it preloads the drive springs 11 . It is latched by pushing in on the activation trigger 2 . The stop and adjustment tabs 19 control the depth of penetration of the needle 16 so that the optimal depth of penetration is reached for a particular sample site. The sample 15 is drawn from the patient when the device has been deployed by releasing the activation trigger 2 and the needle 16 has been retracted from the patient. The system shown in FIGS. 2A and 2B is comprised of a reusable barrel 1 and associated mechanisms and a sterile disposable 13 . The disposable 13 has an ultra fine gauge needle 16 which is imbedded in a cap until the device is readied for use. FIG. 2B shows the device in the deployed state with a sample in disposable 13 and FIG. 2A shows it undeployed. Main yoke 3 is held by activation triggers 2 which support the main tie rods 4 when the system is undeployed. The system is activated by releasing the activation triggers 2 . This releases the main cam 9 which causes the syringe to be deployed by the drive spring 11 which is captured between the cross support 10 and the syringe clamps 12 . The needle 16 pierces the skin as a result of these actions and the penetration depth is controlled by stop 27 . When the suction cams 8 is released by the secondary trigger 5 , the suction spring 6 is released. This drives the suction yoke 7 up slowly due to the damping action of the syringe plunger 14 so a back pressure or vacuum is created in the syringe body. Sample 15 is actively drawn into the syringe. The sample can be delivered easily and precisely to a test device or other container by pressing down on a button on the top of the sampler. The disposable syringe 13 and needle 16 may be imbedded in the cap in which it was shipped or placed into a Sharps container for safe disposal. To insure that adequate sample size is collected the needle 16 can be vibrated, oscillated or rotated to keep the wound from closing. The disclosure of FIGS. 3, 4 , 4 C, 4 D, 4 E, 4 I, 9 , 12 and 13 show and describe various alternative motions that can be used to accomplish this. Another version of this device is also capable of performing as an auto-injection device. A preloaded tip may be placed into the barrel. The trigger and spring system can be designed to deliver the sample from the syringe rather than to collect a sample. One who is skilled in the art could readily reconfigure the mechanism described to inject a sample. FIG. 3 illustrates a minimally invasive sampling device according to the invention. The device is comprised of numerous components which will be more fully described below. The main body 1 supports the various mechanical components housed within the device. The main body 1 comprises an elongated hollow cylindrical tube with openings at both ends. The sampling needle 16 which is part of the disposable 3 which is capable of being retracted or deployed so that it can protrude beyond the needle guard 17 is positioned at one end. The arming and dispensing plunger 22 protrudes from the other end. The device has a needle guard 17 which can be slid up and down main body 1 by the patient to permit the loading of the disposable 3 . Disposable 3 is attached to the syringe 13 by the tip adapter 18 . The internal parts of the syringe 13 are the plunger 14 which is activated by the suction spring 6 and the suction yoke 7 . The plunger is released when the suction cam 8 is released by the secondary trigger 5 . The syringe 13 is captivated to the drive system by syringe clamp 12 which has the main tie rods 4 anchored to it. The main drive springs 11 are captivated between the syringe clamp 12 and cross support 10 and the tie rods 4 are threaded through them. The main tie rods 4 have the main cams 9 attached to them and are supported by the activation trigger 2 A prior to release. The secondary springs 21 and secondary stops 20 provide a mechanism after activation to pull the needle back out of the wound to permit blood accumulation. When the skin is pierced the secondary springs retract the needle from the wound and initiate the stimulation ring 25 oscillation system 26 and 27 to force blood flow to the wound. The arming and dispensing plunger 22 is a dual purpose device. When the patient pulls up, it preloads the drive springs 11 . It is latched by pushing in on the activation trigger 2 A. The stop and adjustment tabs 19 control the depth of penetration of the needle 16 so that the optimal depth of penetration is reached for a particular sample site. The stimulator ring can be deployed during lancing to keep the skin taut, thus allowing more accurate and repeatable penetration of the skin. The sample 15 is drawn from the patient when the device has been deployed by releasing the activation trigger 2 and the needle 16 has been retracted from the patient. FIG. 4 illustrates the relationship of the needle 16 , wound 200 and stimulation ring 25 . The detail areas of the skin are shown for clarity. The stimulator ring 25 is used to pump the sample of body fluid 61 into wound area 200 . A singular stimulation ring 25 is shown in this illustration. However, multiple telescoping rings may be employed to enhance the blood transport. The stimulation ring can also be formed to with a series of notches to permit the resupply of body fluid to the capillaries when the stimulation ring 25 is retracted from the wound site 200 . In an alternate embodiments the stimulation ring is heated or a secondary motion added to act as a wiper to enhance the flow of body fluid to the wound 200 . Other members can be used instead of a ring to provide the stimulation desired. FIGS. 4C, 4 D and 4 E illustrate that the needle may be vibrated in the desired motion. This creates a momentary opening in which the blood can fill while the device draws the blood through the needle into the disposable sample collection chamber. The vibration of the needle may occur across a broad range, from 30 cycles per minute up to 1000 cycles per minute or more. This slight vibration does not measurably increase the sensation felt by the patient but does markedly increase the sample volume which may be easily withdrawn from a given wound and the rate at which the sample volume is produced from the wound. The oscillation can cause the needle to move up to 2-3 mm per cycle. The optimal needle oscillation is less than 1.5 mm, with about 0.5 mm preferred based on current investigations. Lancing generally occurs at a 90 degree angle (perpendicular) to the skin surface. However, the lancing member may puncture significantly more capillaries if the lancing is performed on a angle. At a very shallow angle, no significant depth of penetration is achieved. Lancing at an incident angle of 15-90 degrees to the surface of the skin is effective, with shallower angles producing greater blood flow. The ultrasonic vibration can cover the range of ultrasonic frequency depending on the sampling area and whether the needle or the stimulation device is being activated. FIGS. 4F and 4G show massaging or kneading the area surrounding the wound. The mechanical motion can displace the area around the wound from 0.05 to 8 mm, with 1-5 mm being preferred based on current investigations. FIG. 4G shows a wiper device which rubs the skin to increase the blood flow to the wound by stimulating the capillaries. This action can also be done by the patient by rubbing the area to increase the blood flow to the sampling site prior to taking a sample. The oscillation can be accomplished via piezoelectric, ultrasonic, or by using a solenoid/coil or a motor and cam. Mechanical oscillation in the range of 2 to 1000 cycles per minute may be employed, with 20 to 200 cycles being preferred. Ultrasonic vibration has been effective at a frequency as high as 40 kHz. FIG. 4F shows an alternate embodiment in which the wound is mechanically stimulated such as by an annular ring which may be oscillated. FIG. 4H shows massaging with a squeegee type of stimulator. Such a squeegee may act on the wound area 2 to 200 times per minute, with 60 times per minute being preferred. FIG. 4I shows rotating or oscillating the needle from 30 cycles per minute up to 1000 cycles per minute or more. This holds the wound open and prevents it from closing and stopping sample collection. This embodiment can employ the needles disclosed herein in FIGS. 4B, 5 A, 5 B, 6 A and 6 B, conventional needles or round or flat lancets. FIGS. 5A and 5B show a spade tip needle/lance profile which is used by the invention to create a void area in the wound. FIGS. 5A and 5B show one needle profile which is useful in implementing this embodiment. The spade end helps create a void area when it is rotated in the small wound. FIGS. 6A and 6B show an asymmetric needle design to create a wound which can enhance capillary blood collection. Needle 16 is molded to form disposable 3 . Another aspect of the invention is the provision of an easily replaceable lancing tip (FIGS. 6 A and 6 B). The tip must attach to the device simply to facilitate the availability of a fresh, sterile needle for each sample drawn. A wide range of lancet or needle gauges may be used for the tip. Current investigations show that 10 through 32 gauge is acceptable depending on the sampling location. The entire device may also be designed as a single use device. In this configuration, the device would be precocked and would only trigger and dispense once. A new device with a sterile tip would be thus used for each sample drawn. It will be apparent that an alternate disposable can be constructed from a needle and flexible tube. The tube acts as a reservoir for the sample as it is drawn by the applied vacuum. Another capillary type disposable is shown in FIG. 31 . The bell type disposable uses capillary action to wick the sample up the tube until it reaches the bulb or vacuum created by depressing the bulb. The sample is dispensed by collapsing the bulb. Anyone skilled in the art would be able to readily reconfigure the design presented herein to be a single use device. FIG. 7 illustrates the use of a needle 16 with a flexible collar 225 and stimulator ring 25 to hold the wound open during the extraction of the body fluid sample. The collar 225 is affixed to the needle and acts as a stop and as a means of spreading the wound. This provides a means of forcing the wound open during sampling. The collar 225 can be fashioned in various configurations to achieve the same results by one skilled in the art. FIG. 8A shows the lancing member is part of a multi-chambered capillary disposable. FIG. 8B provides an exploded view of the end of the device showing the relation ship of lancet 30 , disposable 33 and lancet guide tube 35 . The multi-chambered capillary disposable can be made from any suitable material. FIGS. 8C, 8 D and 8 E show various alternatives of this embodiment. One skilled in the art could readily reconfigure a disposable which would be equal to this invention. The lancet 30 creates the wound and is guided by guide tube 35 . The sample is drawn up the sample collection tube/disposable 33 . The complete device can either be fashioned as one single disposable or multiple components. FIGS. 9A illustrates a minimally invasive sampling device according to the invention using the alternate capillary disposable blood collection device FIG. 8A which is disposable 33 . The device is comprised of numerous components which will be more fully described below. The main body 1 supports the various mechanical components housed within the device. FIG. 9B shows the cutout to allow communication of blood to the sample collection tube. The main body 1 comprises of an elongated hollow cylindrical tube with openings at both ends. The capillary sampling disposable with lancing member 30 , which is part of disposable 33 and is capable of being retracted or deployed so that it can protrude beyond the end of the main body 1 , is positioned at one end. The arming plunger assembly 36 protrudes from the other end. The lancing member 30 is guarded by being withdrawn into the needle guide tube 35 which is part of the disposable 33 . The needle guide tube 35 acts as the lancing guide and lancet guard. The disposable 33 is attached to the main body 1 so that it is positioned at the appropriate location to guide the lancet and suction up the blood. The striker 39 is projected so as to drive the lancet into the patient 41 by the spring 43 and the arming plunger assembly 36 . The arming plunger is locked in place by a cam 45 and trigger 47 . A double stop return spring 49 is located and sized to return the lancet 30 back into the disposable 33 needle guide tube 35 . The needle guard 17 supports the main body 1 on patient 41 . The double stop return springs 49 provide a mechanism after activation to pull the needle back out of the wound to permit blood 61 accumulation. When the skin is pierced the secondary springs 49 retract the needle from the wound and initiate the stimulation ring 25 oscillation system to force blood flow to the wound. The stimulator ring can oscillate in the preferred range of 1 to 5 mm. The frequency can vary from 5 to 1000 cycles per minute in the preferred embodiment. The oscillation of the stimulator ring 25 is driven by the coils 51 which oscillate the stimulator ring 25 to pump the blood 61 from the surrounding capillaries in the skin into the wound. Each down stroke of the stimulator ring 25 provides this pumping action. This pumping action can be modified to include sinusoidal motion, wobbling, kneading or peristaltic motion which will enhance the blood flood to the wound. A linkage 53 drives a peristaltic roller system 55 and rollers 57 against the suction tube 59 causing blood 61 to be drawn up the suction tube 59 creating the sample 15 . The stop and adjustment tabs 19 control the depth of penetration of the lancet 30 so that the optimal depth of penetration is reached for a particular sample site. In another aspect of this invention, electric potential can be applied across the skin to also stimulate blood flow to the wound. This can be accomplished by having separate electrodes present in the device to contact the skin and deliver the electric current at locations desired. Or, the current can be delivered to the skin through components of the device, appropriately insulated internally of course, such as the stimulator ring 25 and sample tube 59 , or any other appropriate combination. In general, low voltage DC or AC current can aid in blood flow. The voltage, amperage and cycles (in the case of AC) can be determined by one skilled in the art, but DC voltage in the range of 1 millivolt to 12 volts will be useful. Likewise, the duration of the applied current or the pulsing thereof can be selected as desired. In a particular example tube 33 in FIG. 9A or needle 16 in FIG. 3 can be the negative electrode and ring 25 in FIG. 9 A and FIG. 3 or guard 17 can be the positive electrode. FIG. 9C illustrates a alternate suction/stand off chamber blood collection device 72 which comprises of lance 30 , suction tube 59 , secondary tube which guides the lance 30 , suction/standoff chamber 105 , and contacts 107 and 109 . The suction tube 59 is mounted in suction/standoff chamber 105 so as to permit the suction tube to be located off the wound to promote bleeding while the wound is stimulated. The contacts provide a means of determining if the sample size is adequate. Contacts 109 are made when adequate volume of blood is present in the cap 105 and these are in communication with contacts 107 which are in communication with the electronic package of the sampler. Once contacts 109 are made by the blood then the circuit is completed signaling the system to stop. FIG. 10 illustrates a minimally invasive sampling device according to the invention using the alternate capillary disposable blood collection device and laser 67 lancing mechanism. The device is comprised of numerous components which will be more fully described below. The main body 1 supports the various mechanical components housed within the device. The main body 1 is comprised of an elongated hollow cylindrical tube with openings at both ends. The capillary sampling disposable with diffusing lens member 60 which is part of disposable 63 is installed in one end of the main body 1 . The firing switch 65 protrudes from the other end. The capillary tube 59 acts as the laser guide and sample collection device. The disposable 33 is attached to the main body 1 so that it is positioned at the appropriate location to direct the laser and to suction up the blood. The laser 67 is diffused by going through the lens and creates the wound in the patient. When the skin is pierced, the laser shuts down. This initiates the stimulation ring 25 oscillation system to force blood flow to the wound. The oscillation of the stimulator ring 25 is driven by the coils 51 which oscillate the stimulator ring 25 so as to pump the blood 61 from the surrounding capillaries in the skin into the wound. Each down stroke of the stimulator ring 25 provides this pumping action. A linkage 53 drives a peristaltic roller system 55 and rollers 57 against the suction tube 59 causing blood 61 to be drawn up the suction tube 59 creating the sample 15 . The oscillation of the stimulator ring can have a range of 0 to 8 mm and preferably 1 to 5 mm. The frequency can also vary from 2 to 100 cycles per minute. In an alternative embodiment for the device of FIG. 10, the lancing means can be a liquid under high pressure or a compressed gas pulse instead of the laser. A pulse of compressed gas, or multiple pulses, can be directed at the skin. In addition, the liquid under pressure or compressed gas pulses can be applied in the annular space between ring 25 and housing 1 to massage and stimulate the skin to increase blood flow to the wound. It is to be understood that the vacuum employed in the various embodiments of this invention can be used with the capillary tubes, such as 59 in FIG. 10, as well as the needles of FIGS. 4B, 5 A and B, and 6 A and B. FIG. 11 illustrates a minimally invasive sampling device according to the invention using the alternate suction/stand off chamber blood collection device 72 which is more fully described in illustration 9 C. The device is comprised of numerous components which will be more fully described below. The main body is 1 which supports the various mechanical components housed within the device. The main body 1 comprises of an elongated hollow cylindrical tube with openings at both ends. The suction/stand off chamber sampling disposable with lancing member 30 which is part of disposable 72 and is capable of being retracted or deployed so that it can protrude beyond the end of the main body 1 positioned at one end. The arming tabs/trigger 37 protrude from the sides of main body 1 . The disposable 72 is attached to the main body 1 so that it is positioned at the appropriate location to guide the lancet and suction up the blood. The striker 39 is projected so as to drive the lancet into the patient 41 by the spring 43 and the arming plunger assembly 37 . The arming plunger is locked in place by a cam 45 and trigger 37 . A double stop return spring 49 is located and sized to return the lancet 30 . In another aspect, the capillary sample collection tubes used in the various embodiments of this invention, such as 33 in FIGS. 8A and 9A, 59 in FIGS. 9C and 10 and 150 in FIGS. 20A-20C, can be selected to have an affinity for the sample fluid greater than the skin so the fluid or blood will wick into the tube by capillary action. However, the capillary tube is also selected to have less affinity for the sample fluid or blood than a test strip or test device surface of receiving port so that the sample fluid or blood will wick out of the capillary tube into or onto the test strip or device. Such materials for the capillary tube can easily be determined and selected by one skilled in the art, but generally capillary tubes of nylon, PTFE, and the like generally fulfill this function. It will be recognized that the selection of such material for the capillary tube must be made relative to the materials present in and the physical construction the test strip or device, if this aspect of the present invention is to be utilized. The double stop return springs 49 provide a mechanism after activation to pull the needle back out of the wound to permit blood 61 accumulation. When the skin is pierced, the secondary springs 49 retract the needle from the wound and initiate the stimulation ring 25 oscillation system to force blood flow from the wound. The stimulator ring can oscillate in the preferred range of 1 to 5 mm. The frequency can vary from 5 to 1000 cycles per minute in the preferred embodiment. The oscillation of the stimulator ring 25 is driven by the motor 51 which oscillate the stimulator ring 25 to pump the blood 61 in the surrounding skin capillaries from the wound so the blood can flow to the surface of the skin, bead up, and contact the disposable 72 . Each down stroke of the stimulator ring 25 provides this pumping action. The disposable 72 is then lowered onto the blood bead using a secondary motion spring 74 that is released by a secondary motion trigger 75 , and suction of the blood initiated. The suction device 85 shown here is a mini syringe which is activated by spring 86 when secondary motion trigger 75 is released causing blood 61 to be drawn up the disposable 72 . The stop and adjustment cap 19 controls the depth of penetration of the lancet 30 so that the optimal depth of penetration is reached for a particular sample site. FIGS. 12A and 12B illustrate a minimally invasive sampling device according to the invention using a disposable piercing apparatus, a reusable sampling device and a disposable absorbent test strip 83 . FIG. 12A shows the device in a side view and FIG. 12B is a front view. The device is comprised of numerous components which will be more fully described below. The main body is 1 which supports the various mechanical components housed within the device. The main body 1 comprises of an elongated hollow cylindrical tube with openings at both ends. The lancing member 30 which is part of disposable 33 is capable of being retracted or deployed so that it can protrude beyond the end of the main body 1 is positioned at one end. The arming tabs 37 protrude from the sides of main body 1 . The lancing member 30 is guarded by being withdrawn into the tube 35 which is part of the disposable 33 . The tube 35 acts as the lancing guide and lancet guard. The disposable 33 is attached to the main body 1 so that it is positioned at the appropriate location to guide the lancet and is held in place by the disposable clamp 3 . The striker 39 is projected so as to drive the lancet into the patient 41 by the spring 43 and the arming plunger assembly 36 . The arming plunger is locked in place by a cam 45 and trigger 47 . A double stop return spring 49 is located and sized to return the lancet 30 back into the tube 35 . The double stop return springs 49 provide a mechanism after activation to pull the needle back out of the wound to permit blood 61 accumulation. When the skin is pierced the secondary springs 49 retract the needle from the wound and initiate the stimulation ring 25 oscillation system to force blood flow to the wound. The cam 55 oscillates the oscillator ring 57 which transmits the motion to stimulation ring 25 . The stimulator ring can oscillate in the preferred range of 1 to 5 mm. The frequency can vary from 5 to 1000 cycles per minute in the preferred embodiment. The oscillation of the stimulator ring is driven by the motor 51 . The battery 56 provides energy to run the motor 51 which oscillates the stimulator ring 25 to pump the blood 61 from the surrounding capillaries in the skin into the wound. Each down stroke of the stimulator ring 25 compresses the stimulator spring 53 which provides the return motion for the stimulator ring 25 . The disposable chemical strip 83 is then lowered onto the blood bead using a secondary motion spring 74 that is released by a secondary motion trigger 75 . The blood is absorbed by the disposable chemical strip 83 which fits into a slot in the main body 1 and the stimulator ring 25 . The stop and adjustment tabs 19 control the depth of penetration of the lancet 30 so that the optimal depth of penetration is reached for a particular sample site. FIGS. 13 and 14 illustrate an integration of the minimally invasive sampling device with a chemical test measurement, such as glucose, and electronic readout according to the invention using a disposable piercing apparatus 33 , a reusable sampling device 1 , a disposable absorbent test strip 83 , and a method of readout such as calorimetric test which is read electronically and has an electronic readout system. FIG. 13 shows the device in a side view and FIG. 14 is a front view. The device is comprised of numerous components which will be more fully described below. The main body is 1 which supports the various mechanical and electrical components housed within the device. The main body 1 comprises of an elongated hollow cylindrical tube with openings at both ends. The lancing member 30 which is part of disposable 33 is capable of being retracted or deployed so that it can protrude beyond the end of the main body 1 is positioned at one end. The arming tabs 37 protrude from the sides of main body 1 . The lancing member 30 is guarded by being withdrawn into the tube 35 which is part of the disposable 33 . The tube 35 acts as the lancing guide and lancet guard. The disposable 33 is attached to the main body 1 so that it is positioned at the appropriate location to guide the lancet and is held in place by the disposable clamp 3 . The striker 39 is projected so as to drive the lancet into the patient 41 by the spring 43 and the arming plunger assembly 36 . The arming plunger is locked in place by a cam 45 and trigger 47 . A double stop return spring 49 is located and sized to return the lancet 30 back into the tube 35 . The double stop return springs 49 provide a mechanism after activation to pull the needle back out of the wound to permit blood 61 accumulation. When the skin is pierced the secondary springs 49 retract the needle from the wound and initiate the stimulation ring 25 oscillation system to force blood flow to the wound. The cam 55 oscillates the oscillator ring 57 which transmits the motion to stimulation ring 25 . The stimulator ring can oscillate in the preferred range of 1 to 5 mm. The frequency can vary from 5 to 1000 cycles per minute in the preferred embodiment. The oscillation of the stimulator ring 25 is driven by the motor 51 . The battery 56 provides energy to run the motor 51 which oscillates the stimulator ring 25 to pump the blood 61 from the surrounding capillaries in the skin into the wound. Each down stroke of the stimulator ring 25 compresses the stimulator spring 53 which provides the return motion for the stimulator ring 25 . The disposable chemical strip 83 is then lowered onto the blood bead using a secondary motion spring 74 that is released by a secondary motion trigger 75 , and suction of the blood initiated. The blood is absorbed by the disposable chemical strip 83 which has been manufactured into the disposable 33 . The strip is then read in place by a LED 88 colorimetric system and analyzed by electronics which are part of the device and displayed on display 84 . The stop and adjustment tabs 19 control the depth of penetration of the lancet 30 so that the optimal depth of penetration is reached for a particular sample site. FIG. 15 illustrates an integration of the minimally invasive sampling device with a chemical test measurement, such as glucose, and electronic readout according to the invention using a disposable piercing apparatus 33 , a reusable sampling device 1 , a disposable absorbent test strip 83 , and a method of readout such as a electrochemical test which is read electronically and has an electronic readout system. The device is comprised of numerous components which will be more fully described below. The main body is 1 which supports the various mechanical and electrical components housed within the device. The main body 1 comprises of an elongated hollow cylindrical tube with openings at both ends. The lancing member 30 which is part of disposable 33 is capable of being retracted or deployed so that it can protrude beyond the end of the main body 1 is positioned at one end. The arming tabs 37 protrude from the sides of main body 1 . The lancing member 30 is guarded by being withdrawn into the tube 35 which is part of the disposable 33 . The tube 35 acts as the lancing guide and lancet guard. The disposable 33 is attached to the main body 1 so that it is positioned at the appropriate location to guide the lancet and is held in place by the disposable clamp 3 . The striker 39 is projected so as to drive the lancet into the patient 41 by the spring 43 and the arming plunger assembly 36 . The arming plunger is locked in place by a cam 45 and trigger 47 . A double stop return spring 49 is located and sized to return the lancet 30 back into the tube 35 . The double stop return springs 49 provide a mechanism after activation to pull the needle back out of the wound to permit blood 61 accumulation. When the skin is pierced the secondary springs 49 retract the needle from the wound and initiate the stimulation ring 25 oscillation system to force blood flow to the wound. The cam 55 oscillates the oscillator ring 57 which transmits the motion to stimulation ring 25 . The stimulator ring can oscillate in the preferred range of 1 to 5 mm. The frequency can vary from 5 to 1000 cycles per minute in the preferred embodiment. The oscillation of the stimulator ring 25 is driven by the motor 51 . The battery 56 provides energy to run the motor 51 which oscillates the stimulator ring 25 to pump the blood 61 from the surrounding capillaries in the skin into the wound. Each down stroke of the stimulator ring 25 compresses the stimulator spring 53 which provides the return motion for the stimulator ring 25 . The disposable test strip 83 is then lowered onto the blood bead using a secondary motion spring 74 that is released by a secondary motion trigger 75 . and suction of the blood initiated. The blood is absorbed by the disposable chemical strip 83 which has been manufactured into the disposable 33 . The strip is then read in place by a milliamp/or millivolt sensing electronics depending on the specific chemistry of the test strip. This reading is converted into a chemical concentration by the onboard electronics and displayed on the LCD on the side of the device. The stop and adjustment tabs 19 control the depth of penetration of the lancet 30 so that the optimal depth of penetration is reached for a particular sample site. FIGS. 16 and 17 illustrate an integration of the minimally invasive sampling device with a chemical test measurement, such as for glucose, using a disposable piercing apparatus 33 , a reusable sampling device 1 , a disposable absorbent test strip 83 capable of providing semiquantitative calorimetric results. The device is comprised of numerous components which will be more fully described below. The main body is 1 which supports the various mechanical and electrical components housed within the device. The main body 1 comprises of an elongated hollow cylindrical tube with openings at both ends. The lancing member 30 which is part of disposable 33 is capable of being retracted or deployed so that it can protrude beyond the end of the main body 1 is positioned at one end. The arming tabs 37 protrude from the sides of main body 1 . The lancing member 30 is guarded by being withdrawn into the tube 35 which is part of the disposable 33 . The tube 35 acts as the lancing guide and lancet guard. The disposable 33 is attached to the main body 1 so that it is positioned at the appropriate location to guide the lancet and is held in place by the disposable clamp 3 . The striker 39 is projected so as to drive the lancet into the patient 41 by the spring 43 and the arming plunger assembly 36 . The arming plunger is locked in place by a cam 45 and trigger 47 . A double stop return spring 49 is located and sized to return the lancet 30 back into the tube 35 . The double stop return springs 49 provide a mechanism after activation to pull the needle back out of the wound to permit blood 61 accumulation. When the skin is pierced the secondary springs 49 retract the needle from the wound and initiate the stimulation ring 25 oscillation system to force blood flow to the wound. The cam 55 oscillates the oscillator ring 57 which transmits the motion to stimulation ring 25 . The stimulator ring can oscillate in the preferred range of 1 to 5 mm. The frequency can vary from 20 to 200 cycles per minute in the preferred embodiment. The oscillation of the stimulator ring 25 is driven by the motor 51 . The battery 56 provides energy to run the motor 51 which oscillates the stimulator ring 25 to pump the blood 61 from the surrounding capillaries in the skin into the wound. Each down stroke of the stimulator ring 25 compresses the stimulator spring 53 which provides the return motion for the stimulator ring 25 . The disposable chemical strip 83 is then lowered onto the blood bead using a secondary motion spring 74 that is released by a secondary motion trigger 75 , and suction of the blood initiated. The blood is absorbed by the disposable chemical strip 83 . The strip is then removed and read by the patient. The stop and adjustment tabs 19 control the depth of penetration of the lancet 30 so that the optimal depth of penetration is reached for a particular sample site. FIG. 18 illustrates an integration of the minimally invasive sampling device using a disposable piercing, stimulating and puncture depth adjustment apparatus 92 . The device can assume any of the configurations described by this invention. This modification replaces items 19 , 30 , 72 , 25 , 3 on a typical reusable sampling device such as FIG. 11 . The disposable unit can incorporate a test strip, a sample container, an electrical sensing unit, or other testing or sampling component. FIG. 19A shows the concept of a dual alternating stimulation ring system. The secondary stimulation ring 120 alternates it's position 180 degrees out of phase of stimulation ring 25 . This creates a peristaltic pumping action on the capillaries adjacent to the wound. This device can be used with any embodiment to increase the blood flow. Link 121 connects the two rings with body 1 . The peristaltic pumping results in squeezing the body fluid to the wound by massaging the fluid inward towards the wound. FIG. 19B shows the concept of concentric collapsing stimulation ring. In this embodiment the inner ring 25 contacts the skin after the outer ring 120 . Spring 299 provides resistance and sequencing so that the outer ring 120 contacts the skin prior to inner ring 25 . This squeezes the body fluid to the wound by massaging the fluid inward towards the wound. In an alternate embodiment ring 25 can also function as the sample collection tube after lancing needle 16 is retracted. In another alternate embodiment compressed gas pulses can be applied in the annular spaces between housing 1 and ring 120 and/or between ring 120 and ring 25 to massage the skin and stimulate blood flow. Such action by compressed gas pulses can be used instead of or in combination with the movement of ring 120 or other stimulation members. FIG. 20A illustrates a bell shape capillary tube 150 which is used to capture a sample of body fluid. The bell shape capillary is shaped to fit around the drop and it is drawn up the tube until it reaches the bulb 151 . This assist in assuring that adequate sample 152 is drawn and the bulb 151 breaks the capillary action. The sample 152 is dispensed by compressing the bulb 151 . The capillary can be heated to increase the draw of the capillary tube and the speed of the sample collection. FIGS. 20B and 20C show an alternative method where the sample 152 is wicked up the tube 150 and the tube is inverted so that the sample can by transferred to a absorbent test pad 153 . FIG. 20D shows a strait capillary 310 where the sample 152 is wicked up the tube 310 and is transferred to the absorbent test pad 153 by capillary action of the pad. The tubes shown in 20 A, 20 B, 20 C, and 20 D can be modified with a surfactant to increase the ability to wick up the bodily fluid. FIG. 21 illustrates a device where the oscillation ring 130 is fixtured to disposable clamp 3 to oscillate the needle 33 to stimulate the wound and hold it open so that it does not close around the wound. In addition a heated ring 135 can be used to increase the capillary volume to stimulate blood flow. FIG. 22A shows a multiple needle lancing device which is used to cause multiple wounds to increase sample size. The multiple needles are of sufficient size and length to minimize the pain sensation and still generate adequate sample size. FIG. 22B shows a broader single lancet which is used to cause multiple wounds to increase sample size. FIGS. 22C and 22D shows a die cut sheet which has small multiple barbs formed in it which is used to cause multiple wounds to increase sample size. The multiple barbs are of sufficient size and length to minimize the pain sensation and still generate adequate sample size. The lancing device of FIGS. 22A through 22D can be used in the sampling devices disclosed herein.

A device and method for lancing a patient, virtually simultaneously producing and collecting a small fluid sample from a body. The device comprises a blood collection system including a lancing needle, drive mechanism, kneading or vibration mechanism, optional suction system, and sample ejection mechanism. The device is preferably sized to be hand-held in one hand and operable with one hand. The device can optionally contain integral testing or analysis component for receiving the sample and providing testing or analysis indication or readout for the user. A method involves piercing the skin at a rapid rate, kneading the surrounding area by ultrasonic action, piezoelectric or mechanical oscillation to stimulate the blood flow from the wound, drawing the fluid using a pumping system.

FIELD OF THE INVENTION The present invention relates to a stress-generating shallow trench isolation structure having a dual composition and methods of manufacturing the same. BACKGROUND OF THE INVENTION Manipulating stress is an effective way of improving charge carrier mobility in a metal oxide semiconductor field effect transistor (MOSFET) and increasing the transconductance (or reduced serial resistance) of the MOSFET that requires relatively small modifications to semiconductor processing while providing significant enhancement to MOSFET performance. When stress is applied to the channel of a semiconductor transistor, the mobility of carriers, and as a consequence, the transconductance and the on-current of the transistor are altered from their original values for an unstressed semiconductor. This is because the applied stress and the resulting strain on the semiconductor structure within the channel affects the band gap structure (i.e., breaks the degeneracy of the band structure) and changes the effective mass of carriers. The effect of the stress depends on the crystallographic orientation of the plane of the channel, the direction of the channel within the crystallographic orientation, and the direction of the applied stress. The effect of stress on the performance of semiconductor devices, especially on the performance of a MOSFET (or a “FET” for short) device built on a silicon substrate, has been extensively studied in the semiconductor industry. The response of the performance of the MOSFET depends on the direction and type of the stress. For example, in a PMOSFET (or a “PFET” in short) utilizing a silicon channel having current flow in a [110] orientation and formed in a (001) silicon substrate, the mobility of minority carriers in the channel (which are holes in this case) increases under a longitudinal compressive stress along the direction of the channel, i.e., the direction of the movement of holes or the direction connecting the drain to the source. Conversely, in an NMOSFET (or an “NFET” for short) utilizing a silicon channel having current flow in a [110] orientation and formed in a (001) silicon substrate, the mobility of minority carriers in the channel (which are electrons in this case) increases under longitudinal tensile stress along the direction of the channel, i.e., the direction of the movement of electrons or the direction connecting the drain to the source. The direction of a longitudinal stress for enhancing the carrier mobility is opposite between the PMOSFET and NMOSFET. In contrast, enhancement of carrier mobility by a transverse stress on a MOSFET utilizing a silicon channel having current flow in the [110] orientation and formed in the (001) silicon substrate requires a tensile transverse stress irrespective of the type of the MOSFET. In other words, tensile transverse stress enhances the carrier mobility of a PMOSFET and the carrier mobility of an NMOSFET. Thus, the direction of a compressive stress for enhancing the carrier mobility is the same between the PMOSFET and NMOSFET. Prior art stress-generating structures such as stress-generating liners formed above a semiconductor substrate and on a gate line is inefficient in transmission of a stress to a channel region of a transistor since the stress is transmitted through gate spacers, and the magnitude of the stress tends to decay rapidly with depth into the semiconductor substrate. Further, in the case of a PMOSFET, no mechanism is provided for reversing the direction of stress between the longitudinal stress and the transverse stress. In other words, if the longitudinal stress is compressive and beneficial to enhance of performance of the PMOSFET, the transverse stress is also compressive, which is disadvantageous to enhancement of performance of the PMOSFET. In view of the above, there exists a need to efficiently transmit stress from a stress-generating structure to a channel in a transistor. Further, there exists a need to decouple the direction of a longitudinal stress and the direction of a transverse stress applied to a channel of a transistor such that both the longitudinal stress and the transverse stress may induce advantageous effects to the mobility of charge carriers in the channel. SUMMARY OF THE INVENTION The present invention addresses the needs described above by providing a semiconductor structure including a shallow trench isolation structure having a dual composition in which a first shallow trench isolation structure portion and a second shallow trench isolation structure portion have different composition and have different stress-generating properties. Methods of manufacturing such a semiconductor structure are also provided. In the present invention, an etch stop layer having etch selectivity to a first shallow trench isolation material is formed on a top surface of a semiconductor substrate. A shallow trench surrounding at least one first active area for forming a first conductivity type transistor, which may be a p-type transistor or an n-type transistor, and at least one second active area for forming an opposite conductivity type transistor is formed. The shallow trench is filled with a first shallow trench isolation material which has a first composition and first stress generating properties. A photoresist is applied over the at least one first active area and the at least one second active area and patterned such that a portion of the first shallow trench isolation material is exposed from a middle portion of the at least one first active area and from edge portions of the at least one second active area. Exposed portions of the first shallow trench isolation material is removed by an anisotropic etch that is selective to the etch stop layer. Cavities, which are formed by removal of the first shallow trench isolation material, are filled with a second shallow trench isolation material which has a second composition and second stress-generating properties. The second shallow trench isolation material is then planarized. A shallow trench isolation structure containing a first shallow trench isolation portion comprising the first shallow trench material and a second shallow trench isolation portion comprising the second shallow trench material is thus formed. A first biaxial stress on the at least one first active area and a second bidirectional stress on the at least one second active area are manipulated separately to enhance charge carrier mobility in middle portions of the at least one first and second active areas by selection of the first and second shallow trench materials as well as adjusting the type of the shallow trench isolation material that each portion of the at least one first active area and the at least one second active area laterally abut. The etch stop layer is removed, and a channel and a gate stack are thereafter formed on each of the at least one first and second active areas that are subjected to different types of biaxial stress. The enhanced charge carrier mobility of the middle portion of the at least one first and second active areas is advantageously employed to provide enhanced performance of both types of field effect transistors. According to an aspect of the present invention, a semiconductor structure is provided, which comprises: an active area comprising a semiconductor material and located in a semiconductor substrate; a first shallow trench isolation portion laterally abutting lengthwise sidewalls of a middle portion of the active area; and a set of two second shallow trench isolation portions, each laterally abutting lengthwise sidewalls and widthwise sidewalls of end portions of the active area, wherein the first shallow trench isolation portion and the set of two second shallow trench isolation portions comprise different materials. In one embodiment, the first shallow trench isolation portion applies a first type of stress to the lengthwise sidewalls of the middle portion of the active area, and each of the second shallow trench isolation portion applies a second type of stress to the lengthwise sidewalls and the widthwise sidewalls of the end portions of the active area, and one of the first and second types is compressive and the other of the first and second types is tensile. In a further embodiment, one of the first shallow trench isolation portion and the set of two second shallow trench isolation portions comprises a stress-generating material that applies a stress to the active area to affect charge carrier mobility of the active area, and the other of the first shallow trench isolation portion and the set of the two second shallow trench isolation portions comprises a non-stress-generating material that does not generate a sufficient stress to affect charge carrier mobility. In an even further embodiment, the stress-generating material is one of a tensile-stress-generating silicon nitride and a compressive-stress-generating silicon nitride, and wherein the non-stress-generating material comprises one of undoped silicate glass (USG), borosilicate glass (BSG), phosphosilicate glass (PSG), fluorosilicate glass (FSG), and borophosphosilicate glass (BPSG). In another embodiment, one of the first shallow trench isolation portion and the set of the second shallow trench isolation portions applies a stress to the active area to affect charge carrier mobility of the active area, and the other of the first shallow trench isolation portion and the set of the second shallow trench isolation portions does not generate a stress that affects the charge carrier mobility. In yet another embodiment, the first shallow trench isolation portion comprises a tensile-stress-generating material and the two second shallow trench isolation portions comprise a compressive-stress-generating material. In still another embodiment, the tensile-stress-generating material is a tensile-stress-generating silicon nitride, and the compressive-stress-generating material is a compressive-stress-generating silicon nitride. In still yet another embodiment, the first shallow trench isolation portion comprises a compressive-stress-generating material and the second shallow trench isolation portions comprise a tensile-stress-generating material. In a further embodiment, the semiconductor structure further comprises: a gate dielectric and a gate electrode located on the active area; and a channel located in the active area and vertically abutting the gate dielectric, wherein the first shallow trench isolation portion and the set of the second shallow trench isolation portions apply a first longitudinal stress along a lengthwise direction in the channel and a second transverse stress along a widthwise direction of the channel, wherein one of the first longitudinal stress and the second transverse stress is compressive, and wherein the other of the first longitudinal stress and the second transverse stress is tensile. In an even further embodiment, the semiconductor structure further comprises: a gate dielectric and a gate electrode located on the active area; and a channel located in the active area and vertically abutting the gate dielectric, wherein the first shallow trench isolation portion and the set of the second shallow trench isolation portions apply a first compressive longitudinal stress along a lengthwise direction in the channel and a second compressive transverse stress along a widthwise direction of the channel. In a yet further embodiment, the semiconductor structure further comprises: a gate dielectric and a gate electrode located on the active area; and a channel located in the active area and vertically abutting the gate dielectric, wherein the first shallow trench isolation portion and the set of the second shallow trench isolation portions apply a first tensile longitudinal stress along a lengthwise direction in the channel and a second tensile transverse stress along a widthwise direction of the channel. In a still further embodiment, the active area is single crystalline. In a still yet further embodiment, the active area is a portion of a top semiconductor layer of a semiconductor-on-insulator (SOI) substrate. In further another embodiment, the active area is a portion of a bulk substrate. In even further another embodiment, the first shallow trench isolation portion and the second shallow trench isolation portions have substantially the same depth. In yet further another embodiment, each of the second shallow trench isolation portions laterally abut the first shallow trench isolation portion. According to another aspect of the present invention, another semiconductor structure is provided, which comprises: a first active area and a second active area, each comprising a semiconductor material and located in a semiconductor substrate and disjoined from each other; a first shallow trench isolation portion laterally abutting lengthwise sidewalls and widthwise sidewalls of end portions of the first active area and laterally abutting lengthwise sidewalls of a middle portion of the second active area; and a second shallow trench isolation portion laterally abutting lengthwise sidewalls and widthwise sidewalls of end portions of the second active area and laterally abutting lengthwise sidewalls of a middle portion of the first active area. In one embodiment, the first shallow trench isolation portion applies a first type of stress to the lengthwise sidewalls and the widthwise sidewalls of the end portions of the first active area and the lengthwise sidewalls of the middle portion of the second active area, and the second shallow trench isolation portion applies a second type of stress to the lengthwise sidewalls and the widthwise sidewalls of the end portions of the second active area and the lengthwise sidewalls of the middle portion of the first active area, and one of the first and second types is compressive and the other of the first and second types is tensile. In a further embodiment, one of the first shallow trench isolation portion and the second shallow trench isolation portion comprises a stress-generating material that applies a compressive stress or a tensile stress to an abutting portion of the first active area and the second active area, and the other of the first shallow trench isolation portion and the second shallow trench isolation portion comprises a non-stress-generating material that does not generate a sufficient stress to affect charge carrier mobility. In an even further embodiment, the stress-generating material is one of a tensile-stress-generating silicon nitride and a compressive-stress-generating silicon nitride, and wherein the non-stress-generating material comprises one of undoped silicate glass (USG), borosilicate glass (BSG), phosphosilicate glass (PSG), fluorosilicate glass (FSG), and borophosphosilicate glass (BPSG). In another embodiment, the first shallow trench isolation portion and the second shallow trench isolation portion collectively enhance electron mobility along a lengthwise direction of the first active area and a hole mobility along a lengthwise direction of the second active area. In even another embodiment, the first shallow trench isolation portion comprises a tensile-stress-generating material and the second shallow trench isolation portion comprises a compressive-stress-generating material. In yet another embodiment, the tensile-stress-generating material is a tensile-stress-generating silicon nitride, and the compressive-stress-generating material is a compressive-stress-generating silicon nitride. In still another embodiment, the first shallow trench isolation portion comprises a compressive-stress-generating material and the second shallow trench isolation portion comprises a tensile-stress-generating material. In a further embodiment, the semiconductor structure further comprises: a first gate dielectric and a first gate electrode located on the first active area; a second gate dielectric and a second gate electrode located on the second active area; a first channel located in the first active area and vertically abutting the first gate dielectric, wherein the first shallow trench isolation portion and the second shallow trench isolation portion apply a first longitudinal stress along a lengthwise direction in the first channel and a first transverse stress along a widthwise direction of the first channel; and a second channel located in the second active area and vertically abutting the second gate dielectric, wherein the first shallow trench isolation portion and the second shallow trench isolation portion apply a second longitudinal stress along a lengthwise direction in the second channel and a second transverse stress along a widthwise direction of the second channel. In an even further embodiment, one of the first longitudinal stress and the second longitudinal stress is compressive, and wherein the other of the first longitudinal stress and the second longitudinal stress is tensile, and the first transverse stress and the second transverse stress are both compressive or both tensile. In a yet further embodiment, the active area is single crystalline. In a still further embodiment, the active area is a portion of a top semiconductor layer of a semiconductor-on-insulator (SOI) substrate. In a still yet further embodiment, the active area is a portion of a bulk substrate. In further another embodiment, the first shallow trench isolation portion and the second shallow trench isolation portion have substantially the same depth. In even further another embodiment, the second shallow trench isolation portion comprises two disjoined second shallow trench isolation sub-portions, each of which laterally abuts the first shallow trench isolation portion. According to yet another aspect of the present invention, a method of fabricating a semiconductor structure is provided, which comprises: forming an etch stop layer on a semiconductor substrate; forming a shallow trench surrounding a first active area and a second active area in the semiconductor substrate; filling the shallow trench with a first shallow trench isolation material having a first composition and first stress-generating properties; forming first cavities laterally abutting lengthwise sidewalls and widthwise sidewalls of end portions of the second active area and second cavities laterally abutting lengthwise sidewalls of a middle portion of the first active area; and filling the first cavities and second cavities with a second shallow trench isolation material having a second composition and second stress-generating properties, wherein the first stress-generating properties and second stress-generating properties are different. In one embodiment, the method further comprises: planarizing the first shallow trench isolation material after the filling of the shallow trench; and planarizing the second shallow trench isolation material after the filling of the first cavities and the second cavities. In another embodiment, one of the first shallow trench isolation material and the second shallow trench isolation material applies a stress to the active area to affect charge carrier mobility of the active area, and the other of the first shallow trench isolation material and the second shallow trench isolation material does not generate a stress that affects the charge carrier mobility. In even another embodiment, the first shallow trench isolation material comprises a tensile-stress-generating material and the second shallow trench isolation material comprises a compressive-stress-generating material. In yet another embodiment, the tensile-stress-generating material is a tensile-stress-generating silicon nitride, and the compressive-stress-generating material is a compressive-stress-generating silicon nitride. In still another embodiment, the first shallow trench isolation material comprises a compressive-stress-generating material and the second shallow trench isolation material comprises a tensile-stress-generating material. In a further embodiment, the method further comprises: forming a first gate dielectric and a first gate electrode on the first active area; forming a second gate dielectric and a second gate electrode on the second active area; forming a first channel in the first active area, wherein the first shallow trench isolation material and the second shallow trench isolation material apply a first longitudinal stress along a lengthwise direction in the first channel and a first transverse stress along a widthwise direction of the first channel; and forming a second channel in the second active area, wherein the first shallow trench isolation material and the second shallow trench isolation material apply a second longitudinal stress along a lengthwise direction in the second channel and a second transverse stress along a widthwise direction of the second channel. In an even further embodiment, one of the first longitudinal stress and the second longitudinal stress is compressive, and the other of the first longitudinal stress and the second longitudinal stress is tensile, and wherein the first transverse stress and the second transverse stress are both compressive or both tensile. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1-6E show sequential views of a first exemplary semiconductor structure according to a first embodiment of the present invention. Figures with the same numeric label correspond to the same stage of manufacturing. FIG. 1 is a vertical cross-sectional view of the first exemplary semiconductor structure. Figures with the suffix “A” are top-down views. Figures with the suffix “B,” “C,” “D,” or “E” are vertical cross-sectional views along the plane B-B′, C-C′, D-D′, or E-E′ respectively, of the corresponding figure with the same numeric label and the suffix “A.” FIGS. 7A-7E are views of a second exemplary semiconductor structure according to a second embodiment of the present invention. FIG. 7A is a top-down view. FIGS. 7B-7E are vertical cross-sectional views along the plane B-B′, C-C′, D-D′, or E-E′ respectively. FIGS. 8A-8E are views of a second exemplary semiconductor structure according to a second embodiment of the present invention. FIG. 8A is a top-down view. FIGS. 8B-8E are vertical cross-sectional views along the plane B-B′, C-C′, D-D′, or E-E′ respectively. FIG. 9A is a result of a simulation for an n-type field effect transistor according to the third embodiment of the present invention. FIG. 9B is a result of a simulation for a p-type field effect transistor according to the third and fourth embodiments of the present invention. FIG. 9C is a result of a simulation for an n-type field effect transistor according to the fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION As stated above, the present invention relates to a stress-generating shallow trench isolation structure having a dual composition and methods of manufacturing the same, which are now described in detail with accompanying figures. It is noted that like and corresponding elements mentioned herein and illustrated in the drawings are referred to by like reference numerals. Referring to FIG. 1 , a first exemplary structure according to the present invention is shown, which comprises a semiconductor-on-insulator (SOI) substrate 8 and an etch stop layer 40 formed thereupon. The SOI substrate 8 containing a handle substrate 10 , a buried insulator layer 20 , and a top semiconductor layer 30 . The handle substrate 10 comprises a semiconductor material such as silicon. Preferably, the handle substrate 10 comprises a single crystalline semiconductor material. The handle substrate 10 may be undoped or have a p-type doping or an n-type doping. The handle substrate 10 may be doped at a dopant concentration from about 1.0×10 15 /cm 3 to about 3.0×10 17 /cm 3 . The buried insulator layer 20 comprises a dielectric material such as silicon oxide or silicon nitride. For example, the buried insulator layer 20 may comprise thermal silicon oxide. The thickness of the buried insulator layer 20 may be from about 20 nm to about 500 nm, and typically from about 100 nm to about 200 nm. The top semiconductor layer 30 comprises a semiconductor material. The thickness of the top semiconductor layer 30 may be from about 5 nm to about 300 nm, and preferably from about 20 nm to about 100 nm. Preferably, the top semiconductor layer 30 comprises a single crystalline semiconductor material. The semiconductor material of the top semiconductor layer 30 may be selected from, but is not limited to, silicon, germanium, silicon-germanium alloy, silicon carbon alloy, silicon-germanium-carbon alloy, gallium arsenide, indium arsenide, indium phosphide, III-V compound semiconductor materials, II-VI compound semiconductor materials, organic semiconductor materials, and other compound semiconductor materials. For example, the semiconductor material of the top semiconductor layer 30 comprises single crystalline silicon. An etch stop layer 40 is formed on the SOI substrate 8 , for example by chemical vapor deposition. The etch stop layer 40 comprises a material that has etch selectivity relative to a first shallow trench isolation material to be subsequently employed. The etch stop layer 40 may comprise a silicon germanium alloy or a silicate glass such as undoped silicate glass (USG), borosilicate glass (BSG), phosphosilicate glass (PSG), fluorosilicate glass (FSG), borophosphosilicate glass (BPSG). Alternately, the etch stop layer 40 may comprise a high-k material containing a metal and oxygen, known in the art as high-k gate dielectric materials. In this case, the etch stop layer 40 may comprise one of HfO 2 , ZrO 2 , La 2 O 3 , Al 2 O 3 , TiO 2 , SrTiO 3 , LaAlO 3 , Y 2 O 3 , HfO x N y , ZrO x N y , La 2 O x N y , Al 2 O x N y , TiO x N y , SrTiO x N y , LaAlO x N y , Y 2 O x N y , a silicate thereof, and an alloy thereof. Each value of x is independently from about 0.5 to about 3 and each value of y is independently from 0 to about 2. Non-stoichiometric variants are also contemplated herein. Yet alternately, the etch stop layer 40 may comprise a dielectric nitride such as TaN, TiN, and WN. The thickness of the etch stop layer 40 depends on the composition of the etch stop layer 40 , the composition of the first shallow trench isolation material, and the thickness of a shallow trench to be subsequently formed. For example, the thickness of the etch stop layer may be from about 10 nm to about 200 nm, and preferably from about 10 nm to about 100 nm, and more preferably from about 10 nm to about 50 nm. Referring to FIGS. 2A-2D , a first photoresist 47 is applied over the etch stop layer 40 and lithographically patterned. The pattern in the first photoresist 47 is transferred into the etch stop layer 40 , the top semiconductor layer 30 , and the buried insulator layer 20 . A first group of remaining portions of the top semiconductor layer 30 within a first device region 100 constitutes at least one first active area 30 A. A second group of the remaining portions of the top semiconductor layer 30 within a second device region 200 constitutes at least one second active area 30 B. The volume from which portions of the etch stop layer 40 , portions of the top semiconductor layer 30 , and portions of the buried insulator layer 20 are removed constitutes a shallow trench 67 . The bottom surface of the shallow trench 67 is located between a top surface of the buried insulator layer 20 and a bottom surface of the buried insulator layer, which is an interface between the buried insulator layer 20 and the handle substrate 10 . Each of the at least one first active area 30 A and the at least one second active area 30 B may have a polygonal or elliptical horizontal cross-sectional area. In case one of the active areas ( 30 A, 30 B) has a polygonal horizontal cross-sectional area, a pair of lengthwise sidewalls and a pair of widthwise sidewalls may be present in the active area. Preferably, each of the at least one first active area 30 A and the at least one second active area 30 B has a rectangular cross-sectional area. In this case, the lengthwise direction is the direction of a set of longer sidewalls and the widthwise direction is the direction of a set of shorter sidewalls. In general, the lengthwise direction refers to the direction of a set of longest sidewalls, and the widthwise direction refers to the horizontal direction that is perpendicular to the lengthwise direction. For the purposes of the present invention, rectangular cross-sectional areas are assumed for each of the at least one first active area 30 A and the at least one second active area 30 B. Embodiments in which the sidewalls are curved and/or the cross-sectional areas contain a polygon that is not a rectangle are also explicitly contemplated herein. Each of the at least one first active area 30 A and the at least one second active area 30 B contain a pair of lengthwise sidewalls and a pair of widthwise sidewalls. Each lengthwise sidewall may be directly adjoined to two widthwise sidewalls, and each widthwise sidewall may be directly adjoined to two lengthwise sidewalls. Each of the at least one first active area 30 A and the at least one second active area 30 B contains a top semiconductor surface 31 , which is also an interface between the etch stop layer 40 and one of the at least one first active area 30 A and the at least one second active area 30 B. The shallow trench 67 comprises the cavity below an etch stop layer top surface 41 , which is a top surface of the etch stop layer 40 . Referring to FIGS. 3A-3E , the first photoresist 47 is removed, for example, by ashing. The first exemplary semiconductor structure may be cleaned, for example, by a wet clean. A first shallow trench isolation material is deposited into the shallow trench 67 , and is then planarized. The first shallow trench isolation material may be a stress-generating material or a non-stress-generating material that does not apply a substantial amount of stress to surrounding regions including the at least one first active area 30 A and the at least one second active area 30 B. The measure of stress, as described in the present invention, is the impact on mobility of charge carriers, which are holes or electrons, in the at least one first active area 30 A or the at least one second active area 30 B. Thus, a stress-generating material applies a sufficient level of stress to the at least one first active area 30 A or the at least one second active area 30 B to alter the charge carrier mobility therein. A non-stress-generating material does not generate a stress that materially alters charge carrier mobility in the at least one first active area 30 A or the at least one second active area 30 B. The first shallow trench isolation material is a dielectric material. The first shallow trench isolation material may be deposited, for example, by low pressure chemical vapor deposition (LPCVD), high density plasma chemical vapor deposition (HDPCVD), plasma enhanced chemical vapor deposition (PECVD), or other deposition methods for dielectric materials. In case the first shallow trench isolation material comprises a stress-generating material, the first shallow trench isolation material may apply a compressive stress or a tensile stress to surrounding regions, i.e., may be a compressive-stress-generating material or a tensile-stress-generating material. An exemplary compressive-stress-generating material is a compressive-stress-generating silicon nitride. An exemplary tensile stress-generating material is a tensile stress-generating silicon nitride. Methods of forming the compressive-stress-generating silicon nitride or the tensile-stress-generating silicon nitride are known in the art. In case the first shallow trench isolation material comprises a non-stress-generating material, the first shallow trench isolation material does not apply a substantial level of stress to surrounding regions. For the purposes of the present invention, materials having an intrinsic stress less than 100 MPa are considered to be non-stress-generating. Exemplary non-stress-generating materials include, but are not limited to, undoped silicate glass (USG), borosilicate glass (BSG), phosphosilicate glass (PSG), fluorosilicate glass (FSG), and borophosphosilicate glass (BPSG). The first shallow trench isolation material is then planarized by chemical mechanical polishing (CMP), a recess etch, or a combination thereof. When chemical mechanical planarization is employed, the etch stop layer 40 may be used as a stopping layer. When a recess etch is employed, the etch stop layer 40 may be use as an endpoint layer so that the recess etch may stop upon detection of exposure of the etch stop layer 40 . At the end of planarization, the first shallow trench isolation material filling the shallow trench 67 constitutes a prototype shallow trench isolation structure 70 P, which is contiguous throughout the first exemplary semiconductor structure at this point. Preferably, a top surface of the prototype shallow trench isolation structure 70 P is coplanar with the etch stop layer top surface 41 , which is the top surface of the etch stop layer 40 . Referring to FIGS. 4A-4E , a second photoresist 77 is applied over the etch stop layer 40 and the prototype shallow trench isolation structure 70 P. The second photoresist is lithographically patterned to expose a middle sub-portion of each portion of the etch stop layer 40 overlying one of the at least one first active area 30 A. Further, two end sub-portions of each portion of the etch stop layer 40 overlying one of the at least one second active area 30 B are also exposed. Substantially vertical edges of the second photoresist 77 cross a vertical extension of lengthwise edges of each of the at least one first active area 30 A and the at least one second active area 30 B. The second photoresist 77 overlies widthwise edges of each of the at least one first active area 30 A. The second photoresist 77 does not overlie widthwise edges of the at least one second active area 30 B. The second photoresist 77 overlies end-portions of each of the at least one first active area 30 A. The second photoresist 77 also overlies a middle portion of each of the at least one second active area 30 B. The second photoresist 77 does not overlie a middle portion of the at least one first active area 30 A. The second photoresist 77 does not overlie end-portions of the at least one second active area 30 A. Thus, a middle portion of each of the at least one first active area 30 A herein denotes a portion of the at least one first active area 30 A that underlies an opening in the second photoresist 77 . Likewise, a middle portion of each of the at least one second active area 30 B herein denotes a portion of the at least one second active area 30 B that underlies the photoresist 77 . Each middle portion of the at least one first active area 30 A laterally abuts two end portions of the first active area 30 A that contains the middle portion. Each middle portion of the at least one second active area 30 B laterally abuts two end portions of the second active area 30 B that contains the middle portion. An anisotropic etch is performed to removed exposed portions of the prototype shallow trench isolation structure 70 P employing the second photoresist 77 and the etch stop layer 40 as etch masks. As described above, the etch stop layer 40 has etch selectivity relative to the first shallow trench isolation material, which is the material of the prototype shallow trench isolation structure 70 P. First cavities 68 A are formed in the second device region 200 and second cavities 68 B are formed in the first device region 100 A as the first shallow trench isolation material is removed. The remaining portions of the prototype shallow trench isolation structure 70 P constitute a first shallow trench isolation portion 70 , which may comprise a plurality of disjoined sub-portions, i.e., a plurality of first shallow trench isolation sub-portions. Not necessarily but preferably, the anisotropic etch is selective to the buried insulator layer 20 . In this case, a bottom surface of the first shallow trench isolation portion 70 , bottom surfaces of the first cavities 68 A, and bottom surfaces of the second cavities 68 B are substantially at the same level, i.e., are substantially at the same depth from the top semiconductor surface 31 . Lengthwise sidewalls, i.e., sidewalls in the lengthwise direction, of the middle portion of each of the at least one first active area 30 A are exposed, and laterally abut one of the second cavities 68 B in the first device region 100 . Lengthwise sidewalls and widthwise sidewalls, i.e., sidewalls in the widthwise direction, of the end portions of each of the at least one second active area 30 B are exposed, and laterally abut one of the first cavities 68 A in the second device region 200 . Referring to FIGS. 5A-5E , a second shallow trench isolation material is deposited into the first cavities 68 A and the second cavities 68 B, and is then planarized. The second shallow trench isolation material is then planarized by chemical mechanical polishing (CMP), a recess etch, or a combination thereof. When chemical mechanical planarization is employed, the etch stop layer 40 may be used as a stopping layer. When a recess etch is employed, the etch stop layer 40 may be use as an endpoint layer so that the recess etch may stop upon detection of exposure of the etch stop layer 40 . At the end of planarization, the second shallow trench isolation material filling the first cavities 68 A and the second cavities 68 B constitutes a second shallow trench isolation portion 80 . Preferably, a top surface of the second shallow trench isolation portion 80 is coplanar with the etch stop layer top surface 41 , which is the top surface of the etch stop layer 40 . The first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 collectively constitute a shallow trench isolation structure of the present invention. The first shallow trench isolation portion 70 may comprise a plurality of disjoined first shallow trench isolation sub-portions. The second shallow trench isolation portion 80 may comprise a plurality of disjoined second shallow trench isolation sub-portions. The second shallow trench isolation material is different from the first shallow trench isolation material. The second shallow trench isolation material may be a stress-generating material or a non-stress-generating material that does not apply a substantial amount of stress to surrounding regions including the middle portion of each of the at least one first active area 30 A and the end portions of each of the at least one second active area 30 B. The measure of stress is the impact on mobility of charge carriers as described above. At least one of the first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 comprises a stress-generating material. In one case, the first shallow trench isolation material applies a first type of stress to the lengthwise sidewalls and the widthwise sidewalls of the end portions of the at least one first active area 30 A and the lengthwise sidewalls of the middle portion of the at least one second active area 30 B. The second shallow trench isolation material applies a second type of stress to the lengthwise sidewalls and the widthwise sidewalls of the end portions of the at least one second active area 30 B and the widthwise sidewalls of the middle portions of the at least one first active area 30 A. In this case, one of the first and second types is compressive and the other of the first and second types is tensile. In another case, only one of the first shallow trench isolation material and the second shallow trench isolation material is a stress-generating material. The other of the first shallow trench isolation material and the second shallow trench isolation material is a non-stress-generating material, i.e., a material having an intrinsic stress less than 100 MPa such as undoped silicate glass (USG), borosilicate glass (BSG), phosphosilicate glass (PSG), fluorosilicate glass (FSG), and borophosphosilicate glass (BPSG). The stress-generating material may be a compress-stress-generating material such as a compress-stress-generating silicon nitride or a tensile-stress-generating material such as a tensile-stress-generating silicon nitride. In one example, the first shallow trench isolation portion 70 comprises a tensile-stress-generating material and the second shallow trench isolation portion 80 comprises a non-stress-generating material. Stress effects of the first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 in this example are shown schematically in arrows. A longitudinal tensile stress, i.e., a tensile stress along the lengthwise direction, is applied to each of the middle portion of the at least one first active area 30 A. A longitudinal compressive stress, i.e., a compressive stress along the lengthwise direction, is applied to each of the middle portion of the at least one second active area 30 B. A transverse tensile stress, i.e., a transverse stress along the widthwise direction, is applied to each of the middle portion of the at least one first active area 30 A and each of the middle portion of the at least one second active area 30 B. Embodiments in which the polarity of the longitudinal and transverse stresses is reversed are explicitly contemplated herein. Embodiments in which each of the first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 comprise a stress-generating material and the second shallow trench isolation portion 80 applies an opposite type of stress than the stress generated by the first shallow trench isolation portion 70 to amplify the stress effects of the example described above are explicitly contemplated herein. Referring to FIGS. 6A-6E , the etch stop layer 40 is removed by an etch. The etch may be a wet etch, a reactive ion etch, a chemical downstream etch, or an isotropic dry etch. A gate stack comprising a gate dielectric 90 and a gate electrode 92 is formed on each middle portion of the at least one first active area 30 A and each middle portion of the at least one second active area 30 B. Gate spacers 94 may be formed by a conformal deposition of a dielectric layer followed by a reactive ion etch on sidewalls of each of the gate stack ( 90 , 92 ). A first channel C 1 is formed in each of the middle portion of the at least one first active area 30 A that vertically abuts a gate dielectric 90 in the first device region 100 . The shallow trench isolation structure ( 70 , 80 ) comprising the first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 applies a first longitudinal stress along a lengthwise direction in the first channel C 1 and a first transverse stress along a widthwise direction of the first channel C 1 . A second channel C 2 is formed in each of the middle portion of the at least one second active area 30 B that vertically abuts a gate dielectric 90 in the second device region 100 . The shallow trench isolation structure ( 70 , 80 ) comprising the first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 applies a second longitudinal stress along a lengthwise direction in the second channel C 2 and a first transverse stress along a widthwise direction of the second channel C 2 . Preferably, one of the first longitudinal stress and the second longitudinal stress is compressive, and the other of the first longitudinal stress and the second longitudinal stress is tensile. Preferably, the first transverse stress and the second transverse stress are both compressive or both tensile. In one example, each of the at least one first active area 30 A may comprise silicon, the first device region 100 may comprise at least one p-type field effect transistor, the first longitudinal stress may be a compressive stress, and the first transverse stress may be tensile. Both the first longitudinal stress and the first transverse stress enhance hole mobility in each of the at least one first active area 30 A. At the same time, each of the at least one second active area 30 B may comprise silicon, the second device region 200 may comprise at least one n-type field effect transistor, the second longitudinal stress may be a tensile stress, and the second transverse stress may be tensile. Both the second longitudinal stress and the second transverse stress enhance electron mobility in each of the at least one second active area 30 B. Referring to FIGS. 7A-7E , a second exemplary semiconductor structure according to a second embodiment of the present invention is shown. In the second embodiment, the first shallow trench isolation structure 70 laterally encloses the entirety of each of the at least one first active area 30 A. The second exemplary semiconductor structure may be manufactured by employing identical processing steps as the first embodiment except that the entirety of the first device region 100 is covered by the second photoresist 77 after lithographic patterning of the second photoresist 77 at the step corresponding to FIGS. 4A-4E . Thus, only one group of active areas, i.e., the at least one second active areas 30 B, is surrounded by a patterned shallow trench isolation structure having a heterogeneous composition. As in the first embodiment, a first channel C 1 is formed in each of the middle portion of the at least one first active area 30 A that vertically abuts a gate dielectric 90 in the first device region 100 . The first shallow trench isolation portion 70 comprising the first shallow trench isolation material applies a first longitudinal stress along a lengthwise direction in the first channel C 1 and a first transverse stress along a widthwise direction of the first channel C 1 . A second channel C 2 is formed in each of the middle portion of the at least one second active area 30 B that vertically abuts a gate dielectric 90 in the second device region 100 . The shallow trench isolation structure ( 70 , 80 ) comprising the first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 applies a second longitudinal stress along a lengthwise direction in the second channel C 2 and a first transverse stress along a widthwise direction of the second channel C 2 . Preferably, one of the first longitudinal stress and the second longitudinal stress is compressive, and the other of the first longitudinal stress and the second longitudinal stress is tensile. Preferably, the first transverse stress and the second transverse stress are both compressive or both tensile. In one example, each of the at least one first active area 30 A may comprise silicon, the first device region 100 may comprise at least one p-type field effect transistor, the first longitudinal stress may be a compressive stress, and the first transverse stress may be tensile. Both the first longitudinal stress and the first transverse stress enhance hole mobility in each of the at least one first active area 30 A. At the same time, each of the at least one second active area 30 B may comprise silicon, the second device region 200 may comprise at least one n-type field effect transistor, the second longitudinal stress may be a tensile stress, and the second transverse stress may be tensile. Both the second longitudinal stress and the second transverse stress enhance electron mobility in each of the at least one second active area 30 B. Referring to FIGS. 8A-8E , a third exemplary semiconductor structure according to a third embodiment of the present invention is shown. The third exemplary semiconductor structure employs a bulk substrate 8 ′ in which at least one first active area 30 A′ is formed in the first device region 100 and at least one second active area 30 B′ is formed in the second device region 200 . Each of the at least one first active area 30 A′ and the at least one second active area 30 B′ denotes a portion of the bulk substrate 8 ′ above a bottom surface of the shallow trench isolation structure containing a first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 . The third exemplary semiconductor structure may be manufactured by employing the same manufacturing methods as the first embodiment except for the replacement of the SOI substrate 8 with the bulk substrate 8 ′. According to a fourth embodiment of the present invention, a fourth exemplary semiconductor structure (not shown) is derived from the second exemplary semiconductor structure by replacing the SOI substrate 8 with a bulk substrate as in the third embodiment and employing the same processing steps as in the second embodiment of the present invention. Referring to FIG. 9A , a result of a simulation for longitudinal stress and transverse stress distribution at the center of a channel of an n-type field effect transistor according to the third embodiment of the present invention is shown. The simulation assumes a nested array of first active areas comprising silicon and having a width of 100 nm and a depth of 400 nm, which is the same as the depth of the first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 . Each of the first active areas constitutes an instance of the n-type field effect transistor. The first shallow trench isolation portion 70 comprises a tensile-stress-generating silicon nitride, which applies a tensile stress of about 1.5 GPa to surrounding regions that abut the first shallow trench isolation portion 70 . The second shallow trench isolation portion 80 comprises a silicate glass and has an inherent stress level less than 100 MPa, and typically less than about 30 MPa. The third exemplary semiconductor structure generates a longitudinal tensile stress of about 400 MPa and a transverse tensile stress of about 1.3 GPa in the channel of the n-type field effect transistor. Both stress components enhance electron mobility in the channel of the n-type field effect transistor. Referring to FIG. 9B , a result of a simulation for a p-type field effect transistor according to the third and fourth embodiments of the present invention is shown. It is noted that the second device region 200 contains the same structure between the third exemplary semiconductor structure and the fourth exemplary semiconductor structure. The simulation assumes a nested array of second active areas comprising silicon and having a width of 100 nm and a depth of 400 nm, which is the same as the depth of the first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 . Each of the second active areas constitutes an instance of the p-type field effect transistor. The first shallow trench isolation portion 70 comprises a tensile-stress-generating silicon nitride, which applies a tensile stress of about 1.5 GPa to surrounding regions that abut the first shallow trench isolation portion 70 . The second shallow trench isolation portion 80 comprises a silicate glass and has an inherent stress level less than 100 MPa, and typically less than about 30 MPa. The third and fourth exemplary semiconductor structure generate a longitudinal compressive stress of about 400 MPa and a transverse tensile stress of about 950 MPa in the channel of the p-type field effect transistor. Both stress components enhance hole mobility in the channel of the p-type field effect transistor. Referring to FIG. 9C , a result of a simulation for an n-type field effect transistor according to the fourth embodiment of the present invention is shown. The simulation assumes a nested array of first active areas comprising silicon and having a width of 100 nm and a depth of 400 nm, which is the same as the depth of the first shallow trench isolation portion 70 and the second shallow trench isolation portion 80 . In this case, the first shallow trench isolation portion 70 completely surrounds each of the first active areas, which constitutes an instance of the n-type field effect transistor. The first shallow trench isolation portion 70 comprises a tensile-stress-generating silicon nitride, which applies a tensile stress of about 1.5 GPa to surrounding regions that abut the first shallow trench isolation portion 70 . The fourth exemplary semiconductor structure generates a longitudinal tensile stress from about 800 MPa to about 1,400 MPa and a transverse tensile stress from about 0 MPa to about 1 GPa in the channel of the n-type field effect transistor. Both stress components enhance electron mobility in the channel of the n-type field effect transistor. While the magnitude of an average longitudinal tensile stress increases over the equivalent magnitude of the third exemplary semiconductor structure, it is observed that the third exemplary semiconductor provides a more uniform longitudinal tensile stress distribution in the channel of the n-type field effect transistor. Further, an average transverse tensile stress on the n-type field effect transistor of the third exemplary semiconductor structure is greater than the average transverse tensile stress on the n-type field effect transistor of the fourth exemplary semiconductor structure. Further, the transverse tensile stress distribution is more uniform in the n-type field effect transistor of the third exemplary semiconductor structure than in the n-type field effect transistor of the fourth exemplary semiconductor structure. While the invention has been described in terms of specific embodiments, it is evident in view of the foregoing description that numerous alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the invention is intended to encompass all such alternatives, modifications and variations which fall within the scope and spirit of the invention and the following claims.

A shallow trench isolation structure containing a first shallow trench isolation portion comprising the first shallow trench material and a second shallow trench isolation portion comprising the second shallow trench material is provided. A first biaxial stress on at least one first active area and a second bidirectional stress on at least one second active area are manipulated separately to enhance charge carrier mobility in middle portions of the at least one first and second active areas by selection of the first and second shallow trench materials as well as adjusting the type of the shallow trench isolation material that each portion of the at least one first active area and the at least one second active area laterally abut.

BACKGROUND OF THE NEW VARIETY The present invention relates to a new, novel and distinct variety of nectarine tree, Prunus persica (subspecies nucipersica ), which has been denominated varietally as ‘Burnecteleven’. ORIGIN The present variety of nectarine tree resulted from an on-going program of fruit and nut tree breeding. The purpose of this program is to improve the commercial quality of deciduous fruit and nut varieties and rootstocks by creating and releasing promising selections of prunus, malus and regia species. To this end we make both controlled and hybrid cross pollinations each year in order to produce seedling populations from which improved progenies are evaluated and selected. The seedling ‘Burnecteleven’ was originated by us from a population of seedlings grown in our experimental orchards located near Fowler, Calif. The seedlings, grown on their own roots, were the result of a controlled cross of the yellow-fleshed ‘Summer Bright’ nectarine tree (U.S. Plant Pat. No. 7,049) which was used as the pollen parent; and the yellow fleshed, clingstone peach tree, ‘A40.005’, (unpatented) which was used as the seed parent. One seedling, which is the present variety, exhibited especially desirable characteristics and was designated as ‘C3.101’. This promising variety was marked for subsequent observation. After the 1996 growing season, this new nectarine variety was selected for advanced evaluation and repropagation. ASEXUAL REPRODUCTION Asexual reproduction of the new and distinct variety of nectarine tree was accomplished by budding the new variety to ‘Nemaguard’ Rootstock (non-patented). This was performed by us in our experimental orchard which is located near Fowler, Calif. Subsequent evaluations have shown those asexual reproductions run true to the original tree. All characteristics of the original tree and its fruit were established and appear to be transmitted through succeeding asexual propagations. SUMMARY OF THE VARIETY ‘Burnecteleven’ is a new and distinct variety of nectarine tree, which is of large size, and which has vigorous growth. The new variety is also a regular and productive bearer of relatively large, firm, yellow fleshed, clingstone fruit which have good flavor and eating quality. This new and novel tree has a medium chilling requirement of approximately 750 hours. The new tree also produces relatively uniformly sized fruit which are distributed throughout the tree, and which has a high degree of red skin coloration, and a firm flesh. The fruit of the new variety also appears to have good handling and shipping qualities. Still further, the ‘Burnecteleven’ Nectarine tree bears fruit that are ripe for commercial harvesting and shipment on approximately July 24 to August 8. In relative comparison with the ‘Summer Bright’ nectarine tree, which is the pollen parent, the new variety ripens about 10 days later than the variety ‘Summer Bright’ at the same geographical location. BRIEF DESCRIPTION OF THE DRAWING The accompanying drawing, which is provided, is a color photograph of the present variety. The photograph depicts two whole mature fruit, and one fruit dissected in substantially the suture plane to expose the flesh and the pit. Additionally the photograph displays a characteristic twig bearing typical leaves, and a pit with the flesh removed. The external coloration of the fruit is shown sufficiently matured for harvesting and shipment. The colors are as nearly true as is reasonably possible in a color representation of this type. Due to chemical development, processing and printing, the leaves and fruit depicted in these photographs may or may not be accurate when compared to the actual specimen. For this reason, future color references should be made to the color plates (Royal Horticultural Society) and descriptions provided hereinafter. DETAILED DESCRIPTION Referring more specifically to the pomological details of this new and distinct variety of nectarine tree, the following has been observed during the sixth fruiting season under the ecological conditions prevailing at orchards located near the town of Fowler, county of Fresno, state of California. All major color code designations are by reference to The R.H.S. Colour Chart (Fourth Edition) provided by The Royal Horticultural Society of Great Britain. Tree: Size.— Generally — Considered medium large as compared to other common commercial nectarine cultivars ripening in the middle to late season of maturity. The tree of the present variety was pruned to a height of approximately 290.0 cm to 320.0 cm at maturity. Vigor.— Moderately vigorous. The present variety grew from about 125.0 cm to 142.0 cm in height during the first growing season. The variety was pruned to a height of approximately 134.6 cm in the first dormant season and primary scaffolds were then selected for the desired tree structure. Productivity.— Productive. Fruit set varies from about twice to several times more than the desired crop load. Fruit set is spaced by thinning to develop the remaining fruit into the desired market size. The number of fruit set varies with climatic conditions and cultural practices during the bloom period and is therefore not distinctive of the variety. Bearer.— Regular. Fruit set has been heavy and thinning was necessary during the past 6 years. Form.— Upright, and pruned to a vase shape. Density.— Medium dense. It has been discovered that pruning the branches from the center of the tree to obtain a resulting vase shape allows for air movement and appropriate amounts of sunlight to enhance fruit color and renewal of fruiting wood throughout the tree. Hardiness.— The present tree was grown and evaluated in USDA Hardiness Zone 9. Winter chilling requirements are approximately 750 hours below 7.0 degrees C. The variety appears to be hardy under typical central San Joaquin Valley climatic conditions. Trunk: Diameter.— Approximately 17.8 cm in diameter when measured at a distance of approximately 15.24 cm above the soil level, at the end of the sixth growing season. Bark texture.— Considered moderately rough, with numerous folds of papery scarfskin being present. Lenticels.— Numerous flat, oval lenticels are present. The lenticels range in size from approximately 3.0 to about 5.0 millimeters in width, and from about 1.0 to about 2.0 millimeters in height. Lenticel color.— Considered an orange brown, (RHS Greyed Orange Group N167 C). Bark coloration.— Variable, but it is generally considered to be dark brown, (RHS Greyed Orange Group 177 A). Branches: Size.— Considered medium for the variety. Diameter.— Average as compared to other varieties. The branches have a diameter of about 8.9 centimeters when measured during the sixth year after grafting. Surface texture.— Average, and appearing furrowed on wood which is several years old. Crotch angles.— Primary branches are considered variable between about 44 to about 54 degrees from the horizontal axis. This characteristic is not considered distinctive of the variety, however. Current season shoots.— Surface texture — Substantially glabrous. Internode length.— Approximately 2.3 to about 2.7 cm. Color of mature branches.— Medium brown, (RHS Greyed Orange 176 A). Current seasons shoots.— Color — Light green, (RHS Yellow Green Group N144 D). The color of new shoot tips is considered a bright and shiny green (RHS Yellow Green Group 144 C). Leaves: Size.— Considered medium large for the species. Leaf measurements have been taken from vigorous, upright, current-season growth at approximately mid-shoot. Leaf length.— Approximately 157.0 to about 174.0 millimeters. Leaf width.— Approximately 32.0 to about 44.0 millimeters. Leaf base shape.— Slightly oblique relative to the leaf longitudinal axis. Leaf form.— Lancelolate. Leaf tip form.— Acuminate. Leaf color.— Dark green, (approximately RHS Green Group 141 B). Leaf texture.— Glabrous. Lower surface.— Medium green, (RHS Yellow Green Group 144 A). Leaf venation.— Pinnately veined. Mid - vein.— Color — Light yellow green, (RHS Yellow Green Group N144 C). Leaf margins.— Slightly undulating. Form — Considered crenate, occasionally doubly crenate. Uniformity — Considered generally uniform. Leaf petioles.— Size — Considered medium short. Length — About 7.0 to about 11.5 mm. Diameter — About 1.5 to about 2.5 mm. Color — Pale green, (RHS Yellow Green Group N144 A). Leaf glands.— Size — About 1.0 mm in height, and about 1.0 mm in width. Number — Generally one per side, occasionally two per side. Type — Globose, and considered reasonably unappressed relative to the petiole margin. Color — Grey brown, (RHS Grey Brown Group199 B). Leaf stipules.— Size — Medium for the variety. Number — Typically 2 per leaf bud, and up to 6 per shoot tip. Form — Lanceolate in form and having a serrated margin. Color — Green, (RHS Green Group N138 A) when young but graduating to a brown color, (RHS Greyed Orange group N167 A) with advancing senescence. The stipules are considered to be early deciduous. Flowers: Flower buds.— Generally — The floral buds, depending upon the stage of development are approximately 5.0 millimeters wide; and about 10.0 millimeters long; conic in form; and slightly appressed relative to the bearing shoot. Flower buds.— Color — The bud scales are reddish-brown, (approximately RHS Greyed Purple Group 183 A). The buds are considered hardy under typical central San Joaquin Valley climatic conditions. Hardiness.— No winter injury has been noted during the last several years of evaluation in the central San Joaquin Valley. The current variety has not been intentionally subjected to drought or heat stress, and therefore this information is not available. Date of first bloom.— Mar. 3, 2002. Blooming time.— Considered mid-season in comparison to other commercial nectarine cultivars grown in the central San Joaquin Valley. Date of full bloom was observed on Mar. 8, 2002. The date of first bloom varies slightly with climatic conditions and cultural practices. Duration of bloom.— Approximately 9 days. This characteristic varies slightly with climatic conditions. Flower type.— The variety is considered to have a non-showy type flower. Flower size.— Flower diameter at full bloom is approximately 33.0 to about 39.0 millimeters. Bloom quantity.— Considered abundant. Flower bud frequency.— Normally 1 to 2 appear per node. Petal size.— Generally — Considered small for the species. Length — Approximately 12.0 to about 17.0 millimeters. Width — Approximately 9.0 to about 11.0 millimeters. Petal form.— Broadly ovoid. Petal count.— Nearly always 5. Petal texture.— Glabrous. Petal color.— Light pink when young, (RHS Red Purple Group N57B) and darkening with advancing senescence and exposure to sunlight to a medium to dark pink, (RHS Red Purple Group 58 C). Fragrance.— Slight. Petal claw.— Form — The claw is considered truncate, and has a small size when compared to other varieties. Length — Approximately 5.0 to about 7.0 millimeters. Width — Approximately 4.0 to about 6.0 millimeters. Petal margins.— Generally considered variable, from nearly smooth, to moderately undulate and ruffled, especially apically. Petal apex.— Generally — The petal apices generally appear entire, and without an apical groove. Flower pedicel.— Length — Considered medium-long, and having an average length of approximately 2.0 to about 3.0 millimeters. Diameter — Considered average, approximately 2.0 millimeters. Color — A medium brown, (RHS Grey Brown Group N199 C). Floral nectaries.— Color — A Dull orange red, (RHS Greyed Orange Group N172 C). Calyx.— Surface Texture — Generally glabrous. Color — A dull purple, (approximately RHS Greyed Purple Group 187 A). Sepals.— Surface Texture — The surface has a short, fine pubescent texture. Size — Average, and ovate in form. Color — A dull red, (approximately RHS Greyed Purple Group 183 A). Anthers.— Generally — Average to below average in length. Color — Red to reddish-purple dorsally, (approximately RHS Greyed Purple Group 187 C). Pollen production.— Pollen is abundant, and has a yellow color, (approximately RHS Yellow Orange Group 17 B). Filaments.— Size — Variable in length, approximately 12.0 to about 16.0 millimeters. Color — Considered a very pale pink, (RHS Red Purple Group 62 D). Pistil.— Number — Usually 1, rarely 2. Generally — Average in size. Length — Approximately 17.0 to about 19.0 millimeters including the ovary. Color — Considered a very pale green, (approximately RHS Yellow Green Group 154 D). Surface Texture — The variety has a long glabrous pistil. Fruit: Maturity when described.— Firm ripe condition (shipping ripe); Date of first picking — Jul. 24, 2002; and date of last picking — Aug. 11, 2002. The date of harvest varies slightly with the prevailing climatic conditions. Size.— Generally — Considered large, and uniform. Average cheek diameter.— Approximately 79.0 to about 83.0 millimeters. Average axial diameter.— Approximately 73.0 to about 80.0 millimeters. Typical weight.— Approximately 260.0 grams. This is highly dependent upon cultural practices and therefore is not distinctive of the variety. Fruit form.— Generally — Moderately oblate. The fruit is generally uniform in symmetry. Fruit suture.— Shallow, and extending from the base to apex. No apparent callousing or stitching exists along the suture line. Suture.— Color — The background color appears to be a yellow to golden yellow, (approximately RHS Orange Group 24 A), and occasionally having some red coloration, (approximately RHS Red Group 46 A). Ventral surface.— Form — Slightly indented. Apex.— Rounded. Base.— Retuse. Stem cavity.— Rounded, and considered relatively deep. Average depth of the stem cavity is about 1.65 cm. Average width is about 2.45 cm. Fruit skin.— Thickness — Considered medium in thickness, and tenacious to the flesh. Texture — Substantially glabrous. Taste — Non-astringent. Tendency to crack — None observed. Color.— Blush Color — This red blush color is variable from a reddish orange, (approximately RHS Red Group 42 B) to a dark red, (approximately RHS Red Group 46 A). Blush color ranges from about 75% to about 95% of the fruit surface depending upon the sunlight exposure and the prevailing growing conditions. Ground Color — Yellow orange, (approximately RHS Orange Group 24 A). Fruit stem.— Relatively long in length, approximately 7.0 to about 9.0 millimeters. Diameter — Approximately 2.0 to about 3.0 millimeters. Color — Pale yellow-green, (approximately RHS Greyed Orange Group 163 C). Flesh.— Ripens — Evenly. Texture — Firm, and dense. Considered non-melting. Fibers — Few, small, and tender. Aroma — Very slight. Eating Quality — Very good. Flavor — Considered sweet and mildly acidic. The flavor is considered both pleasant and balanced. Juice — Moderate. Brix — About 14.0 degrees. This characteristic varies slightly with of number of fruit per tree; prevailing cultural practices, and the surrounding climatic conditions. Flesh Color — Pale yellow, (approximately RHS Yellow Orange Group 14 C). The flesh can also exhibit red flecks that increase in frequency and intensity closer to the pit, (approximately RHS Red Group 46A). Stone: Type.— Clingstone. Size.— Considered medium to large for the new variety. Length.— Average, about 29.5 to about 33.0 millimeters. Width.— Average, about 24.0 to about 27.0 millimeters. Diameter.— Average, about 18.0 to about 20.0 millimeters. Form.— Obovoid. Base.— The stone is usually rounded, but may vary from rounded to straight. Apex.— Shape — The stone apex is raised, and has an acute, short tip. Stone surface.— Surface Texture — Irregularly furrowed toward the apex, and pitted toward the base. The stone exhibits substantial pitting laterally. Substantial grooving over the apical shoulders is evident. Surface pitting is prominent generally, and more frequently, it is present basally. Ridges — The surface texture varies from sharp to rounded. Generally one ridge is located on the lateral sides and is positioned just below the mid-point, apically is slightly exaggerated in prominence, the ridge extends in a looping fashion from the dorsal to the ventral edge as seen in the drawing. Ventral edge — Width — Considered medium, and having a dimension of approximately 3.0 to about 5.0 millimeters at the mid-suture. The wings are most prominent over the suture line. Dorsal edge — Shape — Full, heavily grooved, and having jagged edges. The dorsal edge is moderately eroded over the apical shoulder. Stone color.— The color of the dry stone is a purple brown, (approximately RHS Greyed Orange Group 176A). Tendency to split.— Very few splits have been noted. Kernel.— Size — Kernel is considered medium to large. Form — Considered ovoid. Pellicle — Texture — Pubescence has not developed at fruit senescence. Color — (RHS Greyed Orange Group 165 B). Use.— The subject variety ‘Burnecteleven’ is considered to be a Nectarine tree of the middle to late season of maturity, and which produces fruit which are considered to be firm, attractively colored, and which are useful for both local and long distance shipping. Keeping quality.— Excellent. Fruit has stored well up to 25 days after harvest at 1.0 degree Celsius. Shipping quality.— Good. Fruit showed minimal bruising of the flesh or skin damage after being subjected to normal harvesting and packing procedures. Resistance to insects and disease.— No particular susceptibilities were noted. The present variety has not been tested to expose or detect any susceptibilities or resistances of the new variety to any known plant and/or fruit diseases. Although the new variety of nectarine tree possesses the described characteristics when grown under the ecological conditions prevailing near Fowler, Calif., in the central part of the San Joaquin Valley of California, it should be understood that variations of the usual magnitude and characteristics incident to changes in growing conditions, fertilization, pruning, pest control and horticultural management are to be expected.

A new and distinct variety of nectarine tree ( Prunus persica sub species nuciperisica ), denominated varietally as ‘Burnecteleven’, and which produces an attractively colored yellow-fleshed, clingstone nectarine which is mature for harvesting and shipment approximately July 24 to August 8 under ecological conditions prevailing in the San Joaquin Valley of Central California.

[0001] This application hereby incorporates by reference U.S. patent application Ser. No. 10/055,800, filed Oct. 26, 2001, titled Electronically Controlled Vehicle Lift And Vehicle Service System and U.S. Provisional Application Serial No. 60/243,827, filed Oct. 27, 2000, titled Lift With Controls, both of which are commonly owned herewith. BACKGROUND OF THE INVENTION [0002] This invention relates generally to vehicle lifts and their controls, and more particularly to a vehicle lift control adapted for maintaining multiple points of a lift system within the same horizontal plane during vertical movement of the lift superstructure by synchronizing the movement thereof. The invention is disclosed in conjunction with a hydraulic fluid control system, although equally applicable to an electrically actuated system. [0003] There are a variety of vehicle lift types which have more than one independent vertically movable superstructure. Examples of such lifts are those commonly referred to as two post and four post lifts. Other examples of such lifts include parallelogram lifts, scissors lifts and portable lifts. The movement of the superstructure may be linear or non-linear, and may have a horizontal motion component in addition to the vertical movement component. As defined by the Automotive Lift Institute ALI ALCTV-1998 standards, the types of vehicle lift superstructures include frame engaging type, axle engaging type, roll on/drive on type and fork type. As used herein, superstructure includes all vehicle lifting interfaces between the lifting apparatus and the vehicle, of any configuration now known or later developed. [0004] Such lifts include respective actuators for each independently moveable superstructure to effect the vertical movement. Although typically the actuators are hydraulic, electromechanical actuators, such as a screw type, are also used. [0005] Various factors affect the vertical movement of superstructures, such as unequal loading, wear, and inherent differences in the actuators, such as hydraulic components for hydraulically actuated lifts. Differences in the respective vertical positions of the independently superstructures can pose significant problems. Synchronizing the vertical movement of each superstructure in order to maintain them in the same horizontal plane requires precisely controlling each respective actuator relative to the others to match the vertical movements, despite the differences which exist between each respective actuator. BRIEF DESCRIPTION OF THE DRAWING [0006] The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings: [0007] [0007]FIG. 1 is a schematic diagram of an embodiment of a control in accordance with the present invention, embodied as a hydraulic fluid control system including the controller and hydraulic circuit. [0008] [0008]FIG. 2 is a control diagram showing the complete raise control including the raise circuit and the position synchronization circuit for a pair of superstructures. [0009] [0009]FIG. 3 is a control diagram showing the complete lower control including the lowering circuit and the position synchronization circuit for a pair of vertically superstructures [0010] [0010]FIG. 4 is a control diagram showing the lift position synchronization circuit for two pairs of superstructures. [0011] [0011]FIG. 5 is a control diagram illustrating the generation of movement control signals for raising each superstructure of each of two pairs. [0012] [0012]FIG. 6 is a schematic diagram of another embodiment of a control in accordance with the present invention showing the controller and a different hydraulic circuit different from that of FIG. 1. [0013] Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. DETAILED DESCRIPTION OF THE INVENTION [0014] Referring now to the drawings in detail, wherein like numerals indicate the same elements throughout the views, FIG. 1 illustrates a vehicle lift, generally indicated at 2 . Lift 2 is illustrated as a two post lift, including a pair of independently moveable actuators 4 and 6 which cause the respective superstructures (not shown) to move. In the depicted embodiment, first and second actuators 4 and 6 are illustrated as respective hydraulic cylinders, although they may be any actuator suitable for the control system. First and second actuators 4 and 6 are in fluid communication with a source of hydraulic fluid 8 . Pressurized hydraulic fluid is provided by pump 10 at discharge 10 a . Each actuator 4 and 6 has a respective proportional flow control valve 12 and 14 interposed between its actuator and source of hydraulic fluid 8 . [0015] The hydraulic fluid flow is divided at 16 , with a portion of the flow going to (from, when lowered) each respective actuator 4 and 6 as controlled by first and second proportional flow control valves 12 and 14 . As illustrated, isolation check valve 18 is located in the hydraulic line of either actuator 4 or 6 (shown in FIG. 1 in hydraulic line 20 of actuator 6 ), between 16 and second flow control valve 14 to prevent potential leakage from either actuator 4 or 6 through the respective flow control valve 12 and 14 from affecting the position of the other actuator. [0016] Isolation check valve 18 can be eliminated if significant leakage through first and second flow control valves 12 and 14 does not occur. In the embodiment depicted, equalizing the hydraulic losses between 16 and actuator 4 , and 16 and actuator 6 , makes it easier to set gain factors (described below). To achieve this, an additional restriction may be included in hydraulic line 20 a between 16 and actuator 4 to duplicate the hydraulic loss between 16 and actuator 6 , which includes isolation check valve 18 . This may be accomplished in many ways, such as through the addition of an orifice (not shown) or another isolation check valve (not shown) between 16 and actuator 4 . [0017] The hydraulic circuit includes lowering control valve 22 which is closed except when the superstructures are being lowered. [0018] Lift 2 includes position sensors 24 and 26 . Each position sensor 24 and 26 is operable to sense the vertical position of the respective superstructure. This may be done by directly sensing the moving component of the actuator, such as in the depicted embodiment a cylinder piston rod, sensing vertical position of the superstructure, or sensing any lift component whose position is related to the position of the superstructure. Recognizing that the position and movement of the superstructures may be determined without direct reference to the superstructures, as used herein, references to the position or movement of a superstructure are also references to the position or movement of any lift component whose position or movement is indicative of the position or movement of a superstructure, including for example the actuators. [0019] Position sensors 24 and 26 are illustrated as string potentiometers, which generate analog signals that are converted to digital signals for processing. Any position measuring sensor having adequate resolution may be used in the teachings of this invention, including by way of non-limiting examples, optical encoders, LVDT, displacement laser, photo sensor, sonar displacement, radar, etc. Additionally, position may be sensed by other methods, such as by integrating velocity over time. As used herein, position sensor includes any structure or algorithm capable of generating a signal indicative of position. [0020] Lift 2 includes controller 28 which includes an interface configured to receive position signals from position sensors 24 and 26 , and to generate movement control signals to control the movement of the superstructures. Movement control signals control the movement of the superstructures by controlling or directing the operation, directly or indirectly, of the lift components (in the depicted embodiment, the actuators) which effect the movement of the superstructure. Controller 28 is connected to first and second flow control valves 12 and 14 , isolation check valve 18 , lowering valve 22 and pump motor 30 , and includes the appropriate drivers on driver board 32 to actuate them. Controller 28 is illustrated as receiving input from other lift sensors (as detailed in copending application Ser. No. 10/055,800), controlling the entire lift operation. It is noted that controller 28 may be a stand alone controller (separate from the lift controller which controls the other lift functions) dedicated only to controlling the movement of the superstructures in response to a command from a lift controller. [0021] In the depicted embodiment, controller 28 includes a computer processor which is configured to execute the software implemented control algorithms every 10 milliseconds. Controller 28 generates movement control signals which control the operation of first and second flow control valves 12 and 14 to allow the required flow volume to the respective actuators 4 and 6 to synchronize the vertical actuation of the pair of superstructures. [0022] [0022]FIG. 2 is a control diagram showing the complete raise control, generally indicated at 34 , including raise circuit 36 and position synchronization circuit 38 for the pair of superstructures. When the lift is instructed to raise the superstructures, complete raise control 34 effects the controlled, synchronized movement of the superstructures based on input from position sensors 24 , 26 . Raise circuit 36 is a feed back control loop which is configured to command the pair of superstructures to an upward vertical trajectory. Raise circuit 36 compares the desired position of the superstructures indicated by vertical trajectory signal 40 (xd) to the actual positions indicated respectively by position signals 42 and 44 (x1 and x2) generated by position sensors 24 , 26 . The respective differences between each set of two signals, representing the error between the desired position and the actual position, is multiplied by a raise gain factor Kp, to generate first raise signal 46 for the first superstructure and second raise signal 48 for the second superstructure, respectively. Although in the depicted embodiment, Kp was the same for each superstructure, alternatively Kp could be unique for each. [0023] In the embodiment depicted, vertical trajectory signal 40 is a linear function of time, wherein the desired position xd is incremented a predetermined distance for each predetermined time interval. It is noted that the vertical trajectory may be any suitable trajectory establishing the desired position of the superstructures (directly or indirectly) based on any relevant criteria. By way of non-limiting example, it may be linear or non-linear, it may be based on prior movement or position, or the passage of time. Alternatively, first and second raise signals 46 and 48 could be fixed signals, independent of the positions of the superstructures. [0024] The vertical trajectory signal resets when the lift is stopped and restarted. Thus, if the upward motion of the lift is stopped at a time when the actual position of the lift lags behind the desired position as defined by the vertical trajectory signal 40 , upon restarting the upward motion, the vertical trajectory signal 40 starts from the actual position of the superstructures. [0025] There are various ways to establish the starting position from which the vertical trajectory signal is initiated. In the depicted embodiment, one of the posts is considered a master and the other is considered slave. When the lift is instructed to raise, the actual position of the superstructures of the master post is used as the starting position from which the vertical trajectory signal starts. Of course, there are other ways in which to establish the starting position of the vertical trajectory signal, such as the average of the actual positions of the two posts. [0026] In the embodiment depicted, vertical trajectory signal 40 is generated by controller 28 . Alternatively vertical trajectory signal 40 could be received as an input to controller 28 , being generated elsewhere. [0027] Position synchronization circuit 38 , a differential feedback control loop, is configured to synchronize the vertical actuation/movement of the pair of superstructures during raising. In the depicted embodiment, position synchronization circuit 38 is a cross coupled proportional-integral controller which generates a single proportional-integral error signal relative to the respective vertical positions of the superstructures. As shown, position synchronization circuit 38 includes proportional control 38 a and integral control 38 b , both of which start with the error between the two positions, x1 and x2, indicated by 50 . Output 52 of proportional control 38 a is the error 50 multiplied by a raise gain factor Kpc 1 . Output 54 of integral control 38 b is the error 50 multiplied by a raise gain factor Kic1, summed with the integral output 54 a of integral control 38 b from the preceding execution of integral control 38 b . Output 52 and output 54 are summed to generate proportional-integral error signal 56 . [0028] Controller 28 , in response to first raise signal 46 and proportional-integral error signal 56 , generates a first movement control signal 58 for the first superstructure. In the depicted embodiment, first movement control signal 58 is generated by subtracting proportional-integral error signal 56 from first raise signal 46 . First movement control signal 58 controls, in this embodiment, first flow control valve 12 so as to effect the volume of fluid flowing to and therefore the operation of first actuator 4 and, concomitantly, the first superstructure. [0029] Controller 28 , in response to second raise signal 48 and proportional-integral error signal 56 , generates a second movement control signal 60 for the second superstructure. In the depicted embodiment, second movement control signal 60 is generated by adding proportional-integral error signal 56 to second raise signal 48 . Second movement control signal 60 controls, in this embodiment, second flow control valve 14 so as to effect the volume of fluid flowing to and therefore the operation of second actuator 6 and, concomitantly, the second superstructure. [0030] [0030]FIG. 3 is a control diagram showing the complete lower control, generally indicated at 62 , including lowering circuit 64 , and position synchronization circuit 66 , a differential feedback control loop, for the pair of superstructures. When the lift is instructed to lower the superstructures, complete lower control 62 effects the controlled movement of the superstructures. [0031] Lowering circuit 64 is configured to generate first lowering signal 68 for the first superstructure and to generate second lowering signal 70 for the second superstructure. In the depicted embodiment, lowering signals are constant, not varying in dependence with the positions of the superstructures or time. Although in the depicted embodiment, lowering signals 68 and 70 are equal, they could be unique for each superstructure. Lowering signals 68 and 70 may alternatively be respectively generated in response to the positions of the superstructures, such as based on the differences between a vertical trajectory and the actual positions. [0032] Position synchronization circuit 66 is similar to position synchronization circuit 38 . Position synchronization circuit 66 is configured to synchronize the vertical actuation/movement of the pair of superstructures during lowering. In the depicted embodiment, position synchronization circuit 66 is a cross coupled proportional-integral controller which generates a single proportional-integral error signal relative to the respective vertical positions of the superstructures. As shown, position synchronization circuit 66 includes proportional control 66 a and integral control 66 b , both of which start with the error between the two positions, x1 and x2, indicated by 72 . Output 74 of proportional control 66 a is the error 72 multiplied by a lowering gain factor Kpc 2 . Output 76 of integral control 66 b is the error 72 multiplied by a lowering gain factor Kic2, summed with the integral output 76 a of integral control 66 b from the preceding execution of integral control 66 b . Output 74 and output 76 are summed to generate proportional-integral error signal 78 . [0033] Controller 28 , in response to first lowering signal 68 and proportional-integral error signal 78 , generates a first movement control signal 80 for the first superstructure. In the depicted embodiment, first movement control signal 80 is generated by adding proportional-integral error signal 78 to first lowering signal 68 . First movement control signal 80 controls, in this embodiment, first flow control valve 12 so as to effect the volume of fluid flowing from and therefore the operation of first actuator 4 and, concomitantly, the first superstructure. [0034] Controller 28 , in response to second lowering signal 70 and proportional-integral error signal 78 , generates a second movement control signal 82 for the second superstructure. In the depicted embodiment, second movement control signal 82 is generated by subtracting proportional-integral error signal 78 from second lowering signal 70 . Second movement control signal 82 controls, in this embodiment, second flow control valve 14 so as to effect the volume of fluid flowing from and therefore the operation of second actuator 6 and, concomitantly, the second superstructure. [0035] The present invention is also applicable to lifts having more than one pair of superstructures. For example, this invention may be used on a four post lift which has two pairs of superstructures, each pair comprising a left and right side of a respective end of the lift or each pair comprising the left side and the right side of the lift. The invention may used with an odd number of superstructures, such as by treating one of the superstructures as being a pair “locked” together. More than two pairs may be used, with one of the pairs being the control or target pair. [0036] For a four post lift, the controller includes an interface configured to receive first and second position signals of the first pair, and to receive third and fourth positions signals of the second pair. The complete up control and complete down control as described above are used for each pair (first and second superstructures; third and fourth superstructures). The respective gain factors between the pairs, or between any superstructures, may be different. Differences in the hydraulic circuits (such as due to different hydraulic hose lengths) can result in the need or use of different gain factors. [0037] The controller is further configured to synchronize the first and second pairs relative to each other through a lift position synchronization control which in the depicted embodiment reduces the difference between the average of the positions of the first pair and the mean of the positions of the second pair. [0038] [0038]FIG. 4 is a control diagram showing the lift position synchronization circuit, a differential feedback control loop, generally indicated at 84 , for synchronizing the two pairs during raising. As shown, lift position synchronization circuit 84 includes proportional control 84 a and integral control 84 b , both of which start with the error, indicated by 86 , between the first pair and the second pair by subtracting the positions of the second pair, x3 and x4, from the positions of the first pair, x1 and x2. Output 88 of proportional control 84 a is the error 86 multiplied by a raise gain factor Kpcc. Output 90 of integral control 84 b is the error 86 multiplied by a raise gain factor Kicc, summed with the integral output 90 a integral control 84 b from the preceding execution of integral control 84 b . Output 88 and output 90 are summed to generate lift proportional-integral error signal 92 . [0039] [0039]FIG. 5 is a control diagram illustrating the generation of movement control signals for raising each superstructure of each of the two pairs. The controller, in response to first raise signal 94 , first pair proportional-integral error signal 96 and lift proportional-integral error signal 92 , generates a first movement control signal 98 for the first superstructure. In the depicted embodiment, first movement control signal 98 is generated by subtracting lift proportional-integral error signal 92 and first pair proportional-integral error signal 96 from first raise signal 94 . First movement control signal 98 controls, in this embodiment, first flow control valve 12 so as to effect the volume of fluid flowing to and therefore the operation of first actuator 4 and, concomitantly, the first superstructure. [0040] The controller, in response to second raise signal 100 , first pair proportional-integral error signal 96 and lift proportional-integral error signal 92 , generates a second movement control signal 102 for the second superstructure. In the depicted embodiment, second movement control signal 102 is generated by adding subtracting lift proportional-integral error signal 92 from the sum of first pair proportional-integral error signal 96 and first raise signal 100 . Second movement control signal 102 controls, in this embodiment, second flow control valve 14 so as to effect the volume of fluid flowing to and therefore the operation of second actuator 6 and, concomitantly, the second superstructure. [0041] Still referring to FIG. 5, the controller, in response to third raise signal 104 , second pair proportional-integral error signal 106 and lift proportional-integral error signal 92 , generates a third movement control signal 108 for the third superstructure. In the depicted embodiment, third movement control signal 108 is generated by subtracting second pair proportional-integral error signal 106 from the sum of lift proportional-integral error signal 92 and third raise signal 104 . Third movement control signal 108 controls, in this embodiment, third flow control valve 110 so as to effect the volume of fluid flowing to and therefore the operation of the third actuator (not shown) and, concomitantly, the third superstructure. [0042] The controller, in response to fourth raise signal 112 , second pair proportional-integral error signal 106 lift proportional-integral error signal 92 , generates a fourth movement control signal 114 for the fourth superstructure. In the depicted embodiment, fourth movement control signal 114 is generated by summing fourth raise signal 112 , second pair proportional-integral error signal 106 and lift proportional-integral error signal 92 . Fourth movement control signal 114 controls, in this embodiment, fourth flow control valve 116 so as to effect the volume of fluid flowing to and therefore the operation of the fourth actuator (not shown) and, concomitantly, the fourth superstructure. [0043] During lowering, the controller executes the lift position synchronization algorithm as shown in FIG. 4, except that the lowering gain factors are not necessarily the same as the raise gain factors. In the depicted embodiment, the lowering gain factors were different from the raise gain factors. During lowering, in the depicted embodiment, the arithmetic operations are reversed for the lift proportional-integral error signal: The lift proportional-integral error signal is added to generate the first and second movement signals (instead of subtracted as shown in FIG. 5) and subtracted to generate the third and fourth movement signals (instead of added as shown in FIG. 5). [0044] The gain factors described above may be set using any appropriate method, such as the well known Zigler-Nichols tuning methods, or empirically. In determining the gain factors empirically, the integral control was disabled and multiple cycles of different loads were raised and lowered to find the optimum gain factor for the proportional control. The integral control was then enabled and those gain factors determined through multiple cycles of different loads. [0045] The following table sets forth two examples of the gain factors and up rate: Example 1 Example 2 Kp 1.0 6.0 Kpc1 0.5 6.0 Kic1 0.15 0.3 Kpc2 1.5 6.0 Kic2 0.25 0.25 Xdown1 65 50 Xdown2 175 175 up rate 2.0 in/sec 1.8 in/sec [0046] It is noted, as seen above, that gain factors may be 1. [0047] The controller preferably includes a calibration algorithm for the position sensors. In the depicted embodiment, whenever the lift is being commanded to move when it is near either end of its range of travel and the position sensors do not indicate movement for a predetermined period of time, the calibration algorithm is executed. In such a situation, it is assumed that the lift is at the end of its range of travel. The algorithm correlates the position sensor output as corresponding to the maximum or minimum position of the lift, as appropriate. The inclusion of a calibration algorithm allows a range of position sensor locations, reducing the manufacturing cost. [0048] The present invention may be used with a variety of actuators and hydraulic circuits. FIG. 6 illustrates an alternate embodiment of the hydraulic circuit. In this vehicle lift, generally indicated at 118 , the difference in comparison to FIG. 1 lies in that control of the flow of hydraulic fluid to actuators 4 and 6 is accomplished through the use of individual motors 120 and 128 and pumps 122 and 130 for each superstructure, with each motor/pump being controlled by a respective variable frequency drive (VFD) motor controller 124 and 132 to effect raising the lift and through the use of respective proportioning flow control valves 126 and 134 to effect lowering the lift. Alternatively, individual motors 120 , 128 could drive a screw type actuator. [0049] As illustrated, each motor/pump 120 / 122 and 128 / 130 has a respective associated source of hydraulic fluid 136 and 138 , although a single source could be associated with both motors and pumps. Each pump 122 and 130 has a respective discharge 122 a and 130 a which is in fluid communication with its respective actuator 4 and 6 . [0050] Controller 140 includes the appropriate drivers for the VFD motor controllers 124 and 132 , and executes the control algorithms as described above to synchronize the vertical actuation of the superstructures. By varying the speed of the respective motors 120 and 132 , the hydraulic fluid flow rate to the respective actuators 4 and 6 varies for raising. [0051] In summary, numerous benefits have been described which result from employing the concepts of the invention. The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described in order to best illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.

A vehicle lift control maintains multiple points of a lift system within the same horizontal plane during vertical movement of the lift engagement structure by synchronizing the movement thereof. A vertical trajectory is compared to actual positions to generate a raise signal. A position synchronization circuit synchronizes the vertical actuation of the moveable lift components by determining a proportional-integral error signal.

RELATED APPLICATIONS: This application claims priority from PCT Application No. PCT/IN2009/000263 filed on May 4, 2009, which in turn claims priority from Indian Provisional Application No. 2366/MUM/2008 filed on Nov. 7, 2008. TECHNICAL FIELD The present invention relates to the novel process for the synthesis of octreotide and derivatives thereof by solid phase peptide synthesis. In particular, the present invention relates to synthesis of protected linear peptides, cleavage from the resin, deprotection followed by cyclization process for the unprotected peptide wherein the preparation process is simple, easy, environment friendly, inexpensive with high yield and purity. BACKGROUND OF INVENTION Octreotide is a highly potent and pharmacologically selective analog of somatostatin. It inhibits growth hormone for long duration and is thereof indicated for acromegaly to control and reduce the plasma level of growth hormone. The presence of D-Phe at the N-terminal and an amino alcohol at the C-terminal, along with D-Tryptophan and a cyclic structure makes it very resistant to metabolic degradation. Octreotide comprises 8 amino acids which has the following structural formula: wherein sulphur atoms of the Cys at the position 2 and of the Cys at the position 7 are mono-cyclic to form an —S—S— bridge. A considerable number of known, naturally occurring small and medium-sized cyclic peptides as well as some of their artificial derivatives and analogs possessing desirable pharmacological properties have been synthesized. However, wider medical use is often hampered due to complexity of their synthesis and purification. Therefore, improved methods for making these compounds in simple, lesser steps and at lesser cost are desirable and this is the felt need of the industry and the mankind. Conventional synthesis of octreotide may be divided into two main approaches, direct solid-phase synthesis and liquid-phase synthesis. Solution phase synthesis has been described by Bauer et al., (Sandoz) (Eur. Pat. Appl. 29,579 and U.S. Pat. No. 4,395,403). The process comprises: removing protected group from peptide; linking together by an amide bond two peptide unit; converting a function group at the N- or C-terminal; oxidizing a straight chain polypeptide by boron tristrifluoroacetate. This process involves a time-consuming, multi-step synthesis, and it is difficult to separate octreotide from the reaction mixtures since all the synthesis steps are carried out in liquid phase. Another solution phase approach described by Chaturvedi, et al., (Wockhardt) in U.S. Pat. No. 6,987,167 and EP 1506219 A, claims the cyclization of partially deprotected octreotide in the solution phase using iodine under conditions and for a time sufficient to form the octreotide. Synthesis in solid phase have been described subsequently (Mergler et al., Alsina et al., Neugebauer). The above prior art for solid phase peptide synthesis cites the octapeptide formation, by starting the synthesis from the threoninol residue which makes it mandatory to protect this residue. Mergler et al., (Peptides: Chemistry and Biology. Proceedings of the 12 th American Peptide Symposium. Smith, J. A. And Rivier J. E. Eds ESCOM, Leiden, Poster 292 Presentation, (1991)) describes a synthetic process, using an aminoethyl resin upon which the Threoninol residue is incorporated with the two alcohol functions protected in acetal form The synthesis is carried out following an Fmoc/tBu protection scheme, forming the disulphide bridge on resin by oxidation of the thiol groups of the previously deprotected cysteine residues and releasing and deprotecting the peptide with a 20% mixture of TFA/DCM. In early 1997, Alsina J. et al. (Alsina J., Chiva C., Ortiz M., Rabanal F., Giralt E., and Albericio F., Tetrahedron Letters, 38, 883-886, 1997) described the incorporation, on active carbonate resins, of a Threoninol residue with the amino group protected by the Boc group and the side chain protected by a Bzl group. The synthesis was then continued by Boc/Bzl strategy. Formation of the disulfide bridge was carried out directly on resin using iodine and the peptide was cleaved from the resin and its side chain protecting groups were simultaneously removed with HF/anisole 9/1. At the final stage the formyl group was removed with a piperidine/DMF solution. Neugebauer (Neugebauer W., Lefevre M. R., Laprise R, Escher E., Peptides: Chemistry, Structure and Biology, p 1017, Marshal G. R. And Rivier J. E. Eds. ESCOM.Leiden (1990) described a linear synthesis with a yield of only 7%. Edwards et al., (Edwards B. W., Fields C. G., Anderson C. J., Pajeau T. S., Welch M. J., Fields G. B., J. Med. Chem. 37, 3749-3757 (1994) carried out another another solid-phase type approximation; they synthesized step-by-step on the resin, the peptide D-Phe-Cys(Acm)-Phe-D-Trp(Boc)-Lys(Boc)-Thr(tBu)-Cys(Acm)-HMP-Resin. Next they proceeded to form the disulfide on resin and then release the peptide from the resin by means of aminolysis with threoninol, with obtaining a total yield of only 14%. The solid phase synthesis described by Yao-Tsung Hsieh et. al., in U.S. Pat. No. 6,476,186 involves the synthesis of octreotide by using Thr(ol)(tBu)-2Cl-trityl resin as starting material followed by the cleavage of the straight chain peptide from the resin by using a strong acid and the formation of the intra-molecular disulfide bond on the completely deprotected octreotide by oxidation using charcoal catalyst and a higher yield of >70%. Another solid phase synthesis described by Berta Ponsati et.al (Lipotec) in U.S. Pat No. 6,346,601 and EP 0953577 B involve the coupling of threoninol on the protected heptapeptide in solution, after a selective acid cleavage from the chlorotrityl resin without affecting the peptide side-chain protecting groups. A hybrid solid phase-liquid phase method for synthesis of octreotide described by Iarov et al., (Dalton Chemical Laboratories) in WO 2005087794 wherein the method comprises liquid phase condensation of two or three peptide blocks in which at least one peptide block is synthesized by solid-phase method. EP 1511761 B1 involves cyclization on the semi-protected linear peptide wherein one of the cysteine residue is protected with an orthogonal protecting group. The radioactive isotope labeling of octreotide by the coupling of bifunctional chelating agents like DTPA or DOTA to the peptide was described by Te-Wei Lee et al., in U.S. Pat. No. 5,889,146 (Inst. of Nuclear Energy Research) The method for cyclization of linear vapreotide by means of intramolecular cysteine formation has been described by Quattrini et. al., (Lonza AG) in WO 2006048144, wherein the process involves the synthesis of linear vapreotide peptide on Sieber-resin (from Novabiochem) by Fmoc standard groups, wherein the side chain protecting groups are D or L-Trp(Boc), Cys(Trt), Lys(Boc), Tyr(tBu). The protected peptide is cleaved off in 5% TFA in dichloromethane and then globally deprotected by acidolysis in a cleavage mix of 300 equivalents of concentrated TFA, 12 equivalents of Dithiothreitol, 12 equivalents of Dichloromethane, 50 equivalents of water for 1 hour at room temperature. The Boc groups are removed. The product was subjected to charcoal method using trace amounts of activated, powdered charcoal wherein a concentration of the linear cysteinyl peptide of 50 mg/ml (1 eq.) in DMF in the presence of 1 eq. Diisopropyl-ethyl-amine and that additionally air was sparged at low pressure into the liquid under stirring. After 15-20 hrs, 100% conversion was achieved with 84% (w/w) analytical yield of 79% vapreotide. The formation of intramolecular disulphide formation in a polypeptide by reacting with hydrogen peroxide has been described by Mineo Niwa et al. (Fujisawa Pharmaceutical Co.) in U.S. Pat. No. 5,102,985 wherein the reaction is to be carried out at a pH of about 6 to 11, wherein the molar ratio of H 2 O 2 to polypeptide is within the range of 1:1 to 100:1. The above cited prior art mainly carries out the cyclization of the peptide on the resin or on partially protected or protected peptides. The use of partial or minimal protecting group strategies and improvement in the activation methods have considerable effect on limitations of poor solubility and possible danger of racemization due to the overactivation of carboxyl groups. However, these approaches do not overcome the problem of the poor coupling efficiency between large peptide segments, because of the intrinsic difficulty of obtaining effective molar concentrations for high molecular weight molecules. OBJECT OF INVENTION The main object of the present invention is to provide a novel process for synthesis of octreotide and derivatives thereof wherein the process uses mild reagents, isolates protected peptide by simple aqueous precipitation, avoids usage of hazardous thiol scavengers in the cleavage cocktail, achieves effective oxidation of deprotected peptide in the presence of hydrogen peroxde to yield a clean crude cyclic octapeptide at a purity of >70% with an overall yield of 95%. Another object of the present invention is to obtain pure octreotide with a purity of >99% with total impurity <1%. Still another object of the invention is an improved process for cyclization of octreotide wherein the cyclization is carried out in the presence of hydrogen peroxide on a completely deprotected heptapeptide or octapeptide. SUMMARY OF INVENTION One embodiment of the present invention is an improved process for preparing octreotide of formula comprising the following steps: i. using H-Cys (Trt)-2-chlorotrityl resin as the starting material, coupling of various selected amino acid residues using coupling agent in polar aprotic solvent to give the straight chain peptide resin compound of formula 2 Boc-D-Phe-Cys(Trt)-Phe-D-Trp-Lys(Boc)-Thr(OBut)-Cys(Trt)-2-Chlorotrityl resin; ii. cleaving the product of step i with a solution comprising of TFA in dichloromethane or acetic acid in dichloromethane to give straight chain peptide of formula 3 Boc-D-Phe-Cys(Trt)-Phe-D-Trp-Lys(Boc)-Thr(OBut)-Cys(Trt)-OH; iii. coupling of threoninol to the C-terminal in the presence of benzotriazole to give linear protected octapeptide of the formula 4 Boc-D-Phe-Cys(Trt)-Phe-D-Trp-Lys(Boc)-Thr(OBut)-Cys(Trt)-Thr-OL; iv. deprotecting the product of step iii with TFA, triisopropylsilane and water to give linear deprotected octapeptide of formula 5 v. oxidizing the deprotected octapeptide of step iv at an acidic pH in the range of 2.5 to 6.5 in the presence of hydrogen peroxide to yield octreotide of formula 1; vi. purifying the crude octreotide of step v by chromatography to a purity of ≧99%; vii. converting the pure octreotide of step vi to acetate salt; viii. concentrating the acetate salt of octreotide of step vii and lyophilizing the same. Second embodiment of the present invention is a process for preparing octreotide of formula comprising the following steps: i. using H-Cys (Trt)-2-chlorotrityl resin as the starting material, coupling of various selected amino acid residues using coupling agent in polar aprotic solvent to give the straight chain peptide resin compound of formula 2 Boc-D-Phe-Cys(Trt)-Phe-D-Trp-Lys(Boc)-Thr(OBut)-Cys(Trt)-2-Chlorotrityl resin; ii. cleaving the product of step i with a solution comprising of TFA in dichloromethane or acetic acid in dichloromethane to give straight chain peptide of formula 3 Boc-D-Phe-Cys(Trt)-Phe-D-Trp-Lys(Boc)-Thr(OBut)-Cys(Trt)-OH; iii. deprotecting the product of step ii with TFA, triisopropylsilane and water to give linear deprotected heptapeptide of formula 6 iv. oxidizing the deprotected heptapeptide of step iii at an acidic pH in the range of 2.5 to 6.5 in the presence of hydrogen peroxide to yield heptapeptide of formula 7 v. coupling of threoninol to the C-terminal in the presence of benzotriazole to yield octreotide of the formula 1; vi. purifying the crude octreotide of step v by chromatography to a purity of ≧99%; vii. converting the pure octreotide of step vi to acetate salt; viii. concentrating the acetate salt of octreotide of step vii and lyophilizing the same. Third embodiment of the present invention is Octreotide of formula 1 as claimed, wherein the purification of the crude cyclic octapeptide to a purity of ≧99% is carried by ion exchange chromatography followed by RP-HPLC in gradient mode. Fourth embodiment of the present invention is a pharmaceutical composition comprising octreotide of formula I as claimed and at least one pharmaceutically acceptable excipient. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS The manner in which the objects and advantages of the invention may be obtained will appear more fully from the detailed description and accompanying drawings, which are as follows: FIG. 1 : RP-HPLC profile of crude octreotide using DMSO for oxidation of S—H to S—S. FIG. 2 : RP-HPLC profile of crude octreotide using H2O2 for oxidation of S—H to S—S. FIG. 3 : RP-HPLC profile of linear protected heptapeptide at 210 nm wavelength. FIG. 4 : RP-HPLC profile of protected octapeptide. FIG. 5 : RP-HPLC purity profile of pure octreotide. FIG. 6 : MS spectrum of pure octreotide with a mass of 1019.9 Da. DETAILED DESCRIPTION OF THE INVENTION Synthesis of peptides on a solid support is a conventional method which has known advantages cited in the prior art. Impurities found with the desired peptide are derived from three sources: namely, coupling of amino acid derivatives to the growing peptide chain, cleavage of the peptide from the solid support, and deprotection of side-chains of the assembled sequence. Impurities often have small differences in structure such as the deletion of one amino acid residue resulting from a slow coupling reaction or a rearranged/derivatized side-chain group formed during the cleavage of the peptide from the solid support. However, in addition to maintaining the purity of the peptide, a major challenge also is to substantially increase the yield or recovery of the peptide synthesized. Complexity increases with the synthesis of cyclic peptides. The preparation of cyclic peptide disulfides from the corresponding SH-precursors and the direct conversion of the cysteine-protected derivatives into cyclic products (deprotection of the -SH groups with simultaneous cyclization) are most widely used among the diversity of methods known for the synthesis of disulfide containing peptides. As a rule, in both cases, the cyclization is carried out in very dilute solutions, with the peptide concentration being of 10 −4 -10 −5 M in order to avoid an intermolecular aggregation and side reactions. The directed formation of S—S bonds in the highly diluted solutions significantly depends on structural peculiarities of a peptide, in particular, on the nature of amino acid residues between Cys residues. The cyclization of free thiols by the air oxygen usually leads to low yields of target products (9-15%). In the air-oxidation process, the proceeding speed of the reaction progress itself is very slow, and especially, it hardly proceeds under denaturing condition, such as in a highly concentrated salt or urea-aqueous solution of polypeptide. The application of potassium ferricyanide or dimethyl sulfoxide usually result in homogeneous reaction mixtures and the yields of cyclic products are considerably higher (from 20 to 60%, and, in some cases, up to 80%, which depends on the peptide structure). However, a multistage purification of product is necessary for the removal of excess of these oxidative agents. Moreover it produces the problem of environmental pollution, since the resultant waste water contains CN − . A very attractive one-step formation of the disulfide bridges by the action of iodine is often accompanied by side reactions and has only a limited use in the case of Trp- and Met-containing peptides. In the iodine-oxidation process, tyrosine residues in a peptide may be disadvantageously iodinated. An inherent feature of the present invention is provision of sufficiently homogenous reaction mixture and a simple, preferably one step isolation of octapeptide of >70% purity which on subsequent chromatographic purification yields an octapeptide of >99% purity. More particularly the oxidation process is easily upscaled and is least cost intensive relatively lowering the manufacturing cost. Producing cyclized peptides with the correct structure can be achieved readily by either on-resin or post-cleavage techniques. On-resin techniques produce greater yields of the final products, but are more expensive to perform. However, post-cleavage techniques are less expensive and provide reasonable yields of the desired product. Another feature of the present invention is post-cleavage cyclization of the heptapeptide and subsequent coupling of threoninol or direct cyclization of the octapeptide to form cyclic octapeptide. The solid-phase synthesis of octreotide had several potential pitfalls that could reduce peptide assembly and cleavage efficiencies and/or resulted in deletereous side reactions. Potential problems included i) racemization of the C-terminal Cys residue, ii) inefficient disulfide bond formation on resin, iii) modification of Trp during disulfide bond formation, and iv) incomplete peptide-resin cleavage. Racemization during the esterification of the C-terminal amino acid or during the chain elongation is suppressed by several alternative techniques. One of the essential feature of the present invention wherein C-terminal Cys peptide is successfully synthesized without racemization by Fmoc based solid phase method using 2-chlorotrityl resin. The use of 2-Chlorotrityl resin circumvents the racemization at the C-terminal cysteine caused by the base treatment, probably due to its high steric hindrance. Another novel feature of the present invention is cyclization of the fully deprotected heptapeptide or octapeptide. Iodine, however, is not without drawbacks as a cyclization agent. For instance, tryptophan moieties present in peptide substrates are at risk of being modified, making the balance between full conversion of starting materials and minimizing side reactions a delicate one, which, in turn, impacts product purity. In the present invention this aspect has been rightfully tackled by not opting for Iodine route for oxidative cyclization. Therefore the process of the present invention has a product of enhanced purity and better yield. Another complicating factor in known synthesis routes is the possibility of interaction between the desired cyclic disulfide and inorganic sulfur compounds used for reducing excess iodine at the end of the reaction, such as sodium dithionite or sodium thiosulfate. Such reducing sulfur-containing compounds may interact with the disulfide linkage, which is sensitive to nucleophilic attack in general. As the process of the present invention does not use iodine, the resulting products have high purity and related impurities are undetectable. The solution phase route is more cumbersome as after each coupling the peptide has to be isolated, as compare to the solid phase route where the excess reagents and by-products are washed off by simple filtration. In both, the desired peptide compound is created by the step-wise addition of amino acid moieties to a growing peptide chain. As compared to Boc-chemistry, Fmoc-chemistry based synthesis is a mild procedure and because of the base liability of Fmoc group, acid-labile side-chain protecting groups are employed giving an orthogonal protection strategy. The rationale for use of protecting groups is that the energy of breaking a bond of a protecting group is lower than any other group in question. Where appropriate, these are based on the tert-butyl moiety: tert-butyl ethers for Ser, Thr, tert-butyl esters for Asp, Glu and Boc for Lys, His. The trt group has been extensively used for the protection of Cys. Also for Cys, the Acm group is extensively used when a protecting group on the sulfur needs to be maintained after the cleavage of the peptide. The guanidine group of Arg is protected by Mtr, Pmc or Pbf. Most Of the Fmoc-amino acids derivatives are commercially available. However, a problem exists in the art for the preparation of modified amino acid peptides as well as cyclic peptide compounds based on disulfide links because separate operations are required before purifying the end product, which increases expense and may effect final product quality and quantity. The purity of a peptide has several aspects. One is purity on the basis of an active-compound concentration scale. This is represented by the relative content of the pharmacologically active compound in the final product, which should be as high as possible. Another aspect is the degree of absence of pharmacologically active impurities, which though present in trace amounts only, may disturb or even render useless the beneficial action of the peptide when used as a therapeutic. In a pharmacological context both aspects have to be considered. As a rule, purification becomes increasingly difficult with larger peptide molecules. In homogeneous phase synthesis (which is the current method of choice for industrial production of larger amounts of peptides) repeated purification required between individual steps provides a purer product but low yield. Thus, improvements in yield and purification techniques at the terminal stages of synthesis are needed. The present invention is an industrially feasible solid phase synthesis and is a novel process to yield a high purity product with greater yields. A general outline for the synthesis of octreotide in the present invention is described as follows: The heptapeptide is synthesized as peptide acid by solid phase peptide synthesis technology on 2-Chloro Trityl chloride Resin using Fmoc chemistry. Instrument: CS936, CS BIO, California; Peptide synthesizer. Resin: H-Cys(Trt)-2Cl Trityl Resin. Activator: HBTU/NMM Solvent: Dimethyl Formamide Deprotection 20% Piperidine in DMF a) The resin H-Cys(Trt)-2Cl Trityl Resin, 10 mmole is transferred to the RV of the CS936 & the linear peptide assembled on it using 1.5-4 times mole excess amino acid derivatives, on the peptide synthesizer. Each coupling is carried out for a time range of 45-90 min. After the couplings are complete, resin is washed with DMF (60-100 ml three washings) followed by 0.2% DIPEA in DCM (60-100 ml six washings) & dried under vacuum. The details of the synthesis are described in the examples. b) cleavage of the peptide from the resin using the cocktail mixture consisting of TFA in DCM or Acetic acid in DCM c) coupling of peptide in formula 3, with Threoninol to give protected octa-peptide of formula 4. d) isolation of peptide post Threoninol coupling by precipitation with water. e) isolation of peptide in step C can also be done by chromatography. f) removal of protecting group by using TFA cocktail mixture from formula 4 followed by oxidation with H 2 O 2 , to give peptide of formula 1. The crude peptide is purified by chromatography. The abbreviations used in this description have the meanings set forth below: Glossary AA Amino Acid ACT Activator Arg Arginine Asp Aspartic Acid Boc Tert-butyloxycarbonyl Cys Cysteine DCM Dichloromethane DEP Deprotection reagent DMF Dimethyl Formamide DIPEA N,N-diisopropylethylamine DMSO Dimethyl slphoxide Fmoc 9-fluorenylmethyloxycarbonyl Glu Glutamic acid Gly Glycine HBTU 2-(1H-Benzotriazole1-yl)-1,1,3,3- tetramethyluronium hexafluorophosphate HF Hydrogen Fluoride HIC Hydrophobic Interaction Chromatography His Histidine IEC Ion Exchange Chromatography LC-MS Liquid Chromatography-Mass Spectroscopy Lys Lysine Mtr 4-methoxy-2,3,6-trimethylbenzenesulfonyl MeOH Methanol NMM N-methyl morpholine Obut O-t-butyl Pbf 2,2,4,6,7-pentamethyldihydrobenzofuran-5- sulfonyl Phe Phenyl alanine Pmc 2,2,5,7,8-pentamethylchroman-6-sulfonyl Pro Proline RP-HPLC Reverse Phase High Performance Liquid Chromatography. RV Reaction Vessel Ser Serine SOLV Solvent SP Synthetic Peptide TEA Triethylamine TFA Trifluoroacetic acid Thr Threonine TIS Triisopropylsilane Trp Tryptophan Trt Trityl EXAMPLES Example 1 Attachment of First Amino Acid Cys(Trt) to 2-Chlorotrityl Chloride Resin to give H-Cys(Trt)-2-Chlorotrityl resin: Fmoc-Cys(Trt)-OH (52.6 gm, 90 mmol) was suspended in 500 ml dichloromethane. DIPEA (47.12 ml, 270 mmole) was added to it. The mixture was stirred for 10 minutes. While under stirring, 2-ChloroTrityl chloride resin(1.13 mmoles/gm, 22.73 g; 30 mmole) was added. The resulting mixture was continuously stirred for one hour under nitrogen atmosphere. The resin was filtered and washed with DMF (80 ml×6 washings for 3 min) followed by 0.2% DIPEA in DCM (60 ml-100 ml×6 washing for 5 min). The resin was capped with MeOH:DCM:DIPEA 200 ml×3, for 5 min each after swelling in DCM. The resin was swelled again in DMF. 20% piperidine in DMF (100 ml×3) was used for deprotection (Fmoc removal) for 5 minutes each. The resin was washed with DMF (60 ml-100 ml×6) for 3 minutes each. The resin was washed with 0.2% DIPEA in DCM (100 ml×3 times) for 3 minutes each time. The resin was dried for 12-15 hours under high vacuum. Yield >90% Substitution: 0.6 mmoles/gm. Example 2 Chemical Synthesis of Protected (1-7) Fragment of Octreotide (heptapeptide): Boc-D-Phe-Cys(Trt)-Phe-(D)Trp-Lys(Boc)-Thr(OBut)-Cys(Trt)-2-ChloroTrityl resin   Formula 2 The peptide was synthesized as peptide acid by solid phase peptide synthesis technology on H-Cys(Trt)-2-chlorotrityl resin using Fmoc chemistry. Instrument CS-BIO-936, Resin Peptide synthesizer H-Cys(Trt)-2-ChloroTrityl resin (0.6 mmoles/gm). Side chain protecting groups Thr: OBut; Cys: Trt; Lys: Boc. Activator HBTU/NMM Solvent Dimethyl Formamide. The H-Cys(Trt)-2-Chlorotrityl resin (16.666 g, 10 mmole) was transferred into the RV of the CS 936. The assembly of the remaining amino acids was carried out using side chain protected Fmoc derivatives of Thr, Lys, (D)Trp, Phe, Cys, and BOC protected (D)Phe with HBTU (2 times excess; 20 mmole) on the peptide synthesizer. Each coupling was carried out for 60 minutes. The completion of coupling was monitored by Kaiser test, which indicated the completeness of coupling reaction (>99%), when negative. After the couplings were complete, resin was washed with 0.2% DIPEA in DCM (100 ml×6) and product was dried under high vacuum over drying agents like calcium chloride. Yield: >90%. Example 3 Cleavage of Protected Heptapeptide Fragment of Octreotide: Boc-(D)Phe-Cys(Trt)-Phe-(D)Trp-Lys(Boc)-Thr(OBut)-Cys(Trt))-OH.  Formula 3 The dried peptidyl-resin(40 gm) was treated with 500 ml of 0.1% TFA v/v in dichloromethane for 5 minutes and filtered. The process was repeated for six times. The filtrate was concentrated under vacuum on rotavap & cold ether was added (300 ml) to precipitate the protected heptapeptide. The precipitate was triturated with spatula and kept in cold followed by filteration through G-4 sintered funnel. The precipitate was washed with 100 ml of ether twice and dried under vacuum. The RP-HPLC profile of linear protected heptapeptide is depicted in FIG. 3 . Yield: >95% Purity by RP-HPLC=88.64% Example 4 Deprotection of Protected Heptapeptide, to get SH-heptapeptide: Cleavage cocktail mixture TFA:TIS:WATER (95:2.5:2.5) was prepared & kept at 4° C. 60 ml of cocktail was added to protected-heptapeptide (3 gm) slowly under stirring and nitrogen atmosphere. Stirring was continued for 2 hours and 45 minutes. The reaction mixture was concentrated. To the concentrate, cold DIPE (600 ml) was added to precipitate the crude ACM-heptapeptide & kept at −20° C. overnight. The precipitate was filtered, followed by DIPE wash and the precipitate dried under vacuum for 18 hours at room temperature. Oxidation of heptapeptide using H2O2: The heptapeptide was oxidised to form disulfide as in Example 7. Coupling of Threoninol to the deprotected disulfide heptapeptide: The deprotected disulfide heptapeptide (300 mg w/w, 0.259 mmole) was dissolved in hydroxy benzotriazole (159 mg, 1.036 mmole), in dimethylacetamide (1 ml) followed by addition of & threoninol (108 mg, 1.036 mmole).The reaction mixture was cooled to 15° C. DCC(60 mg, 0.285 mmole) solution (0.2 ml) was added to the reaction mixture and stirred at 15° C. for 1 hour. Additional stirring was carried out at room temperature for 60 hours. The reaction was monitrored by HPLC. After 20 hours, 70% of the reaction was completed. Further monitored coupling after 60 hours, 85 to 90% of the coupling was completed. The peptide was precipitated from reaction mixture by addition of 40 ml of ethyl acetate followed by stirring at room for 2 hours. The product was filtered on whatman filter paper and dried under vacuum for 20 hours. Purity: 50% Example 5 Coupling of Threoninol to Protected Heptapeptide to Give Protected Octapeptide: Boc-(D)Phe-Cys(Trt)-Phe-(D)Trp-Lys(Boc)-Thr(OBut)-Cys(Trt))-Thr-OL.  Formula 4 The protected heptapeptide (24 gm) and hydroxy benzotriazole (6.26 gm) was dissolved in dimethylacetamide (100 ml) followed by addition of threoninol (4.2 gm). The reaction mixture was cooled to 15° C.-20° C. DCC (3.069 gm) was added to the reaction mixture and stirred at 15° C. for 1 hour. Additional stirring was carried out at room temperature for 24 to 72 hours. After the reaction was completed, the urea was filtered on sinter funnel. The urea was washed with 5 ml of DMAC twice. The filtrate fractions were pooled and dropwise added to 0.5% solution of sodium bicarbonate in 1 L of water under stirring at 20° C., further after 15 minutes 500 ml of water was added at 20° C. The stirring was continued for another 1 hour. The precipitate was filtered and washed with 100 ml of water five times. The RP-HPLC profile of linear protected octapeptide is depicted in FIG. 4 . Dried under vacuum for 30 hours Yield: >95% Purity by RP-HPLC=81.38% Example 6 Deprotection of Protected Octapeptide to Give SH-Octapeptide: The protected octapeptide (23 gm) was treated with TFA/TIS/Water (1150 ml) for 2 hours and 45 minutes for the removal of side chain protecting groups. TFA was evaporated, and peptide precipitated by addition of cold DIPE(500 ml). The solution was filtered and washed with DIPE(100 ml×3) and the precipitate dried. Yield: >95% Example 7 Hydrogen Peroxide Oxidation of S—H Octapeptide: S—H Octapeptide(15 gm) was dissolved in water at a concentration of 2 mg/ml and pH adjusted to 6.5 to 7 with ammonium hydroxide solution. Hydrogen peroxide solution(450 ml) was added in three parts over a period of half hour and allowed to stir at RT over a period of one hour and then acidified to pH <3 with acetic acid. The crude disulfide looped peptide was filtered and solution was taken for IEC purification. The purity was estimated by RP-HPLC ( FIG. 2 ). Purity: 70.5% Example 8 Oxidation of S—H Peptide with DMSO-HCl to Get S—S Peptide: S—H peptide (9 g) was dissolved in 6.5 L DMSO and under ice-cooling 6.5 L 1M HCl was added slowly so that temperature is below 26° C. Stirring was continued for 6 hours. At room temperature after six hours reaction mixture was diluted with 13 L of water and filtered through Whatman no. 41 through Celite bed. The filtrate was loaded on C-18 column for concentration. The compound was eluted with 100% acetonitrile. The eluant was concentrated on rotavap and then the concentrated solution was centri-evaporated to dryness. The RP-HPLC profile of crude octreotide is depicted in FIG. 1 . Weight of crude peptide=3.9g.(45%) Purity: 44.25% Example 9 Purification of Crude Octreotide: The crude octreotide was loaded on to cation ion exchange column and eluted using a salt gradient using a Akta Purifier (by Amersham, Sweden) low pressure chromatography system. The IEX fractions of purity >70% were further loaded for RP-HPLC purification on Kromacil C-18 column of (250×50 mm, 100 A 0 .) The peptide was purified by using aqueous TFA(0-0.5%) and methanol/ethanol and/or Acetonitrile in a gradient program on a Shimadzu preparative HPLC System consisting of a controller, 2 LC8A pumps, and UV-Vis detector. The purified peptide was analysed by analytical RP-HPLC ( FIG. 5 ). Fractions of >99% purity were subjected either by RP-HPLC or IEX to salt exchange and concentrated to remove organic solvent either by rota or reverse osmosis and subsequently lyophilized to get final API with purification step yield of 70% or above.The MS spectrum of octreotide is depicted in FIG. 6 . The above discussed sequences disclosed throughout this specification have the following sequence listings: While the present invention is described above in connection with preferred or illustrative embodiments, these embodiments are not intended to be exhaustive or limiting of the invention. Rather, the invention is intended to cover all alternatives, modifications and equivalents included within its spirit and scope, as defined by the appended claims.

This invention relates a process for preparing octreotide and derivatives thereof. The starting material, Cys(Trt)-2-Chlorotrityl resin is coupled with various amino acids to obtain a protected heptapeptide of formula (2): Boc-D-Phe-Cys(Trt)-Phe-D-Trp-Lys(Boc)-Thr(OBut)-Cys(Trt)-2-Chlorotrityl resin. The linear protected peptide of formula (2) is cleaved from the support using TFA5TIS and water to yield linear protected peptide of formula (3) Boc-D-Phe-Cys(Trt)-Phe-D-Trp-Lys(Boc)-Thr(OBut)-Cys(Trt)-OH Linear protected heptapeptide of formula (3) is deprotected to yield heptapeptide of formula (6): D-Phe-Cys-Phe-D-Tip-Lys-Thr-Cys-OH; which is cyclized using hydrogen peroxide and to the cyclic peptide of formula (7) D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-OH; threoninol is coupled at C terminal to yield octreotide. Alternatively threoninol is coupled to the heptapeptide of formula (3) to yield protected octapeptide of formula (4) Boc-D-Phe-Cys(Trt)-Phe-D-Trp-Lys(Boc)-Thr(OBut)-Cys(Trt)-Thr-OL which is subsequently deprotected to yield linear octapeptide of formula (5) D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-OL and cyclized with hydrogen peroxide to yield cyclic octreotide with a yield of >95%.

TECHNICAL FIELD This invention relates to gene promoters and their use in directing transcription of structural transgenes. BACKGROUND OF THE INVENTION Recombinant DNA technology and genetic engineering have made it possible to introduce desired DNA sequences or genes into cells to allow for the expression of proteins of interest. This technology has been applied in plants to provide plants having unique characteristics. In order to obtain adequate expression of a gene inserted into a plant cell, a promoter sequence operable in plant cells is often required. Promoters are typically untranslated regions upstream from the coding region. They can have various features and regulatory functions but are generally involved in the binding of RNA polymerase to initiate transcription. Although a gene coding for a protein of interest may be available, frequently its promoter will not drive expression in the plant tissues as desired. Additionally, if the gene of interest has been obtained as cDNA, it will not have a promoter. For these reasons, structural genes or antisense sequences are often fused to a promoter isolated from some other gene which may originally have come from the same organism or an entirely different one. Such a promoter is chosen according to its pattern of expression. Often, a promoter which is constitutive in the plant to be transformed is required; that is, a promoter which is always driving the expression of the transgene is needed. The 35S promoter of cauliflower mosaic virus (CaMV35S) is one example of a well known promoter which is constitutive in most plant tissues. In other circumstances, an inducible promoter will be fused to the gene. Such a promoter directs very low levels of transcription or none at all until it is induced by a chemical inducing agent, a change in temperature or some other factor. At other times, a promoter which has a particular developmental pattern of expression is needed. In that case, a promoter capable of directing expression only in the desired tissue must be chosen, because while a gene or antisense sequence introduced into a plant may be of great benefit when expressed at an appropriate tissue location and time, the protein it encodes may be unneeded or even detrimental when present in other tissues or at different times. For example, if a gene was introduced to affect seed oils, a seed specific promoter would be required. Such tissue specific promoters may be constitutive or inducible. Some promoters have already been characterized, including promoters of genes coding for enzymes involved early in the phytoalexin biosynthetic pathway. Phytoalexins are low molecular weight antimicrobial compounds synthesized by plants in response to attempted infection by fungal pathogens or exposure to elicitor macromolecules. (Dixon, et al., "Phytoalexins: enzymology and molecular biology," Adv Enzymol Related Areas Mol Biol 55:1-135 (1983)). Genes encoding early enzymes in the phytoalexin biosynthetic pathway, such as phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS), have been cloned from several plant species, and their developmental and environmental expression patterns studied using promoter-reporter gene fusions. (Liang, et al., "Developmental and environmental regulation of a phenylalanine ammonia-lyase-α-glucuronidase gene fusion in transgenic tobacco plants," Proc Natl Acad Sci USA 86:9284-9288 (1989); Stermer, et al., "Infection and stress activation of bean chalcone synthase promoters in transgenic tobacco," Mol Plant-Microbe Interact 3:381-388 (1990); Ohl, et al., "Functional properties of a phenylalanine ammonia-lyase promoter from Arabidopsis," Plant Cell 2:837-848 (1990); Fritze, et al., "Developmental and UV light regulation of the snapdragon chalcone synthase promoter," Plant Cell 3:893-905 (1991)). The complex expression patterns of these genes are consistent with the involvement of the corresponding enzymes in the synthesis of a wide range of functionally distinct phenylpropanoid-derived secondary products. The promoters of several PAL and CHS genes share common regulatory cis-elements, consistent with the coordinated transcriptional activation of these genes at the onset of the isoflavonoid phytoalexin response. Enzymes specific to isoflavonoid phytoalexin biosynthesis have recently been characterized from several members of the leguminosae. In alfalfa, isoflavone reductase (IFR, E.C. 1.3.1.45) catalyzes the NADPH-dependent reduction of 2'-hydroxyformononetin to vestitone, the penultimate step in the synthesis of medicarpin. Subsequent reduction and ring closure convert vestitone to medicarpin. IFR has been purified and characterized from several legumes and IFR cDNA clones obtained from alfalfa (Paiva, et al., Plant Mol Biol 17:653-667 (1991)), chickpea (Tiemann, et al., "Pterocarpan phytoalexin biosynthesis in elicitor-challenged chickpea (Cicer arietinum L.) cell cultures: Purification, characterization and cDNA cloning of NADPH: isoflavone oxidoreductase" Eur J Biochem 200:751-757 (1991)) and pea (Paiva et al., Archives of Biochemistry & Biophysics 312:501-510 (1994)). In unstressed alfalfa plants, transcripts from the single alfalfa IFR gene are detected mainly in roots and root nodules, consistent with the accumulation of a medicarpin conjugate, medicarpin-3-O-glucoside-6"-O-malonate (MGM) only in these organs. (Paiva, et al., Plant Mol Biol 17:653-667 (1991)). IFR transcript accumulation is, however, strongly induced in infected leaves or elicited cell cultures at the onset of medicarpin accumulation. Thus, the levels of IFR transcript in these tissues are elevated. The IFR promoter has now been isolated and modified for use in driving the expression of genes or DNA sequences operably linked to it. The transcription of sequences which would be useful in plants can be controlled according to the patterns of expression displayed by the IFR promoter and portions thereof in a given transformed plant tissue or species. The IFR promoter helps meet the continuing need for promoters with characteristics which will provide more flexibility, specificity and uniqueness to expression of desired genes in order to advance the field of recombinant plant genetics and to provide increased utilities for introduced genes. SUMMARY OF THE INVENTION New promoters derived from the isoflavone reductase gene upstream activating region are provided. These promoters are capable of directing the transcription of structural genes other than an IFR gene in legumes and other plants. The characteristics of expression depend on which of the IFR-derived promoters are used, the plant tissue and the need or presence of an inducing agent. The invention is also directed to a vector nucleic acid comprising IFR-derived promoters in a transcriptionally functional relationship with a structural gene foreign to it. The invention further comprises plant cells transformed with the IFR-derived promoters in a transcriptionally functional relationship to a structural gene. The invention also comprises a method of expressing a structural gene under the control of an IFR-derived promoter. These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1a-FIG. 1c depict the nucleotide sequence of the alfalfa IFR gene. The sequence of the promoter, 5' and 3' untranslated regions, and exons are in uppercase letters. Introns are indicated in lowercase letters. The deduced amino acid sequence is shown in single-letter code below the exon sequences; the transcription initiation site as determined by primer extension is marked with an arrow (position 766); the possible TATA box (position 732 to 738) and polyadenylation signals (position 2481 to 2486 and 2494 to 2502) are underlined; the polyadenylation site is marked with an arrow (position 2518); and the restriction sites used in the generation of promoter-GUS fusions: EcoRI at position 330 to 335 and SpeI at positions 1 to 6 and 840 to 845 along with the EcoRI site at position 2725 to 2730 that span the 2.4 kb EcoRI fragment of pAOl-1, are underlined and respectively labeled underneath as either EcoRI or SpeI. FIG. 2a depicts restriction maps of the overlapping subclones pAOl-1 and pAO4-1 from which promoter sequences were isolated. The shaded area in both clones represent the promoter sequences that were excised by SpeI digestion. FIG. 2b depicts restriction maps of the relevant portions of the T-DNA portions of the binary vectors pAlf-ifrL-GUS and pAlf-ifrS-GUS. RB, right border; LB, left border; Nos term, nopaline synthase terminator sequence. FIG. 3a is a Northern blot of RNA from unelicited and elicited alfalfa cell suspension cultures probed with a labeled internal HindIII fragment (containing coding sequences for IFR) of pAO1-1. RNA was isolated from cell cultures that were exposed to yeast elicitor for 3 hours. FIG. 3b is a slot blot analysis performed with immobilized cDNA specific to IFR (pIFRalf1) of run-on transcription from nuclei isolated from alfalfa cell suspension cultures treated with yeast elicitor for the times indicated. FIG. 4 is a graph depicting expression of IFR promoter-GUS fusions in cell suspension cultures derived from the transgenic alfalfa plants harboring ifr-L and ifr-S promoter GUS fusions, 35S-GUS, or promoterless GUS (pBI101.1), treated either with yeast elicitor (shaded bars) or water (white bars), and incubated under standard growth conditions for 17 hours. FIG. 5 is a graph depicting expression of IFR promotor-GUS fusions in cell suspension cultures derived from transgenic tobacco plants harboring ifr-L and ifr-S promoter GUS fusions, 35S-GUS, bean CHS8-GUS, and promoterless GUS (pBI101.1), treated either with yeast elicitor (shaded bars) or water (white bars), and incubated under standard growth conditions for 17 hours. DETAILED DESCRIPTION The following description provides details of the manner in which the embodiments of the present invention may be made and used in order to control the expression of transgenes in plants in a way not previously known. The IFR promoter has now been isolated and characterized as to its developmental and elicitor/infection-induced expression in transgenic alfalfa, and in tobacco, a species which lacks the isoflavonoid pathway. As used herein, the term promoter includes all promoter elements, such as, but not limited to, TATA boxes, GC boxes and CCAAT boxes as well as transcriptional control elements including enhancers. Promoter is synonymous with upstream activating region. As IFR is specific for the synthesis of defense-related isoflavonoid compounds, the IFR gene promoter may respond to a more limited set of signals than do PAL and CHS gene promoters. Thus, an IFR-derived promoter will be useful for driving expression of antimicrobial proteins or biosynthetic enzymes in transgenic plants. The present invention involves the isolation, modification and characterization of the IFR promoter as well as its use to control expression of genes in transformed plants. The plants to which the invention can be applied include the commercially important forage legumes such as, but not limited to, alfalfa and large-seeded legumes (grain legumes) such as soybeans, beans and peas. IFR-derived promoters are also useful in plants which lack the isoflavonoid pathway as powerful constitutive promoters for the whole plant or to control expression in certain tissues. In line with the observed patterns of expression, the invention includes the use of IFR-derived promoters fused to a sequence of DNA to be expressed according to the developmental and stress-induced expression the specific promoter directs. In a preferred embodiment, both an approximately 765 base pair and shorter regions of the IFR promoter can be used to drive root-specific constitutive expression as well as elicitor-induced expression in other tissues of legumes. Both the 765 base pair and the shorter promoters have been found to confer stronger expression in elicitor-induced cell cultures of alfalfa than does the commonly used 35S promoter. In another preferred embodiment of the invention, the IFR-derived promoters can be used for constitutive expression of genes when used in heterologous species such as tobacco. The approximately 765 base pair promoter (approximately position 1 to 765 of SEQ ID NO:1) has been shown to confer strong expression in cell cultures of the genes to which it is fused. This promoter can be longer or shorter, but at least a portion of the 329 bp region on the 5' end is required for full constitutive control. Promoters which drive high levels of constitutive expression continue to be of benefit in the field of plant genetics. In another embodiment, at least a portion of an approximately 436 base pair region of the promoter (approximately position 330 to 765 of SEQ ID NO:1) can be used to drive constitutive expression of transgenes in pollen, fruits and seeds of heterologous species. This embodiment also allows inducible expression in the remaining tissues. In another embodiment, an IFR-derived promoter can be fused to a reporter type gene which can serve as an early indicator of plant infection. In yet another embodiment, the promoter can also be useful in screening for substances or conditions which induce defense reactions, and in still another embodiment, it may be possible to delete or alter portions of the IFR promoter to eliminate the constitutive root expression while retaining localized pathogen inducibility as was achieved for the tobacco TobRB7 promoter. (Opperman, et al., "Root-knot nematode--directed expression of a plant root-specific gene," Science 263:221-223 (1994)). Such a pathogen-specific promoter would be valuable for defense strategies which kill both the pathogen and a few host cells by the localized production of the highly toxic product. According to the present invention, there is provided the DNA insert as contained in vectors pAO4-1 and pAOl-1, and any variants that are the functional equivalents thereof. It is expected that additions or deletions can be made to either the 5' or 3' ends of both promoter fragments without altering their activity, which activity can be tested by the methodology of Examples 1-4. The source of the promoters of this invention can be the genomic DNA library of a plant which has the isoflavonoid pathway, according to the procedures taught in this Application or by polymerase chain reaction (PCR) using genomic DNA of such a plant as template. They can be synthesized from the appropriate bases using, for example, FIG. 1a-FIG. 1c or SEQ ID NO:1 as a guide, or arrived at by any of several other ways known in the art. The DNA can be then cloned into a vector, in a position upstream from the coding region of a gene of interest. The sequence to be expressed may be in the sense or antisense orientation. The construct in a suitable expression vector may then be used to transform plants as desired, to make the plants of this invention. Transformation may be accomplished by any known means including Agrobacterium, biolistic process or electroporation. Transformed plants may be regenerated by standard protocols well known to those with average skill in the art, such as organogenesis from leaf discs or somatic embryogenesis. The transformed plants may be propagated sexually, or by cell or tissue culture. EXAMPLE 1 Isolation and Characterization of the Alfalfa Isoflavone Reductase Gene A genomic library of Medicago sativa cv. Apollo (constructed by G. Gowri & B. Shorrosh, Noble Foundation) in the λFix II system (Stratagene, La Jolla, Calif.) was screened using as a probe the 0.75 kb internal HindIII fragment of pIFRalf1. (Paiva et al., Plant Mol Biol 17:653-667 (1991)). Hybridization and washing conditions were as recommended in the manual (Preferred Method) supplied with the Colony/Plaque Screen hybridization transfer membranes (DuPont, Boston, Mass.) except that 6×SSPE replaced 1M NaCl in the hybridizations and SSPE replaced SSC in the washes following hybridizations. Positive clones from the first round of screening were purified by two additional rounds of screening. Restriction mapping and Southern blot hybridization with four positive clones revealed strongly hybridizing 2.4 kb EcoRI and 1.4 kb HindIII fragments in each case, similar to the pattern observed in Southern blot analysis of total alfalfa genomic DNA. (Paiva et al., Plant Mol Biol 17:653-667 (1991)). The hybridizing 2.4 kb EcoRI fragment from one phage clone was subcloned into pBluescript II SK- and designated pAOl-1. Sequence analysis revealed that this clone contained the entire coding region of IFR, but only 528 bp 5' to the open reading frame (ORF). A 5' end-specific probe (XbaI/HindIII fragment of pIFRalf1) was used to identify an overlapping 4 kb HindIII fragment which was also subcloned into pBluescript II SK-. A 2 kb PstI fragment was removed from the 5' end to produce pAO4-1. The complete nucleotide sequence of pAO1-1 (EcoRI to EcoRI site) and additional 5' flanking promoter sequence from pAO4-1 (329 bp; SpeI to EcoRI) are shown in FIG. 1a-FIG. 1c. The positions of four introns were deduced by comparison with the cDNA sequence of pIFRalf1. The splice points conform to the "GT-AG" rule for donor and acceptor sites. (Breathnach, U. and Chambon, P. "Organization and expression of eukaryotic split genes coding for proteins," Annu Rev Biochem 50:349-383 (1981)). The deduced coding regions of pAO1-1 and the cDNA pIFRalf1 were 98.1% identical at the nucleotide level and 99.1% identical at the amino acid level, with only one functionally different amino acid substitution. The start of transcription was mapped by primer extension analysis to 92 nucleotides from the start of translation. A synthetic 22-mer oligonucleotide complementary to the N-terminal end of the IFR coding region (positions 858 to 879) was end-labeled with T4 polynucleotide kinase and γ- 32 P!ATP. Up to 5×10 4 cpm of labeled primer was annealed to 10 μg of total RNA in a 20 μl reaction containing 100 mM Tris-HCl, pH 8.3, 140 mM KCl, 10 mM MgCl2, 20 mM β-mercaptoethanol, 1 mM dNTPs, and 40 units of RNasin (Promega, Madison, Wis.). (Pfitzner, et al., "DNA sequence analysis of a PR-la gene from tobacco: Molecular relationship of heat shock and pathogen responses in plants," Mol Gen Genet 211:290-295 (1988)). The reaction was carried out in the presence of 200 units of reverse transcriptase (Superscript, BRL, Gaithersburg, Md.) at 42° C. for 45 min. The products of the primer extension reaction were analyzed on a 6% polyacrylamide gel containing 8M urea along with a sequencing reaction done on pAO1-1 with the same primer. Sequencing for the primer extension reaction was done using Sequenase (United States Biochemicals, Cleveland, Ohio) according to the instructions provided by the vendor. Transcripts from elicited and unelicited alfalfa suspension cells together with transcripts from alfalfa roots gave the same major primer extension product. In elicited cells, a minor reverse transcription product two nucleotides longer was also observed, probably indicating a second start of transcription from the next available site. A "TATA" box is located 34 nucleotides upstream from the transcription start site, and two possible "CAAT box" elements are located at positions 615 (GTCAATTT) and 653 (CAAT). The 765 bp of available IFR promoter sequence was searched for sequences similar to previously identified cis-elements functional in stress-induced or developmentally-regulated expression of plant defense genes. It was found that regions of IFR have some similarities to Box P; however, there are substantial differences as well. Best matches were for near complete (position 146) and partial (position 626) elements homologous to the Box P region identified as important for elicitor-responsiveness of a parsley PAL promoter. (Lois, et al., "A phenylalanine ammonia-lyase gene from parsley: structure, regulation and identification of elicitor and light responsive cis-acting elements," EMBO J 8:1641-1648 (1989)). Box P binds an elicitor-inducible B-ZIP transcription factor termed BPF-1 (da Costa e Silva, et al., "BPF-1, a pathogen-induced DNA-binding protein involved in the plant defense response," Plant J 4:125-135 (1993)). Related sequences are also present in bean PAL and CHS genes (Dixon, R. A. and Harrison, M. J., "Activation, structure and organization of genes involved in microbial defense in plants," Adv Genetics 28:165-234 (1990)) and in the alfalfa CHS2 gene (N. L. Paiva, H. Junghans, R. A. Gonzales and R. A. Dixon, unpublished results). Other important elements such as the H-box, G-box and SBF-1 binding sites which have been implicated in elicitor-mediated and developmental expression of bean CHS genes (Harrison, et al., "Characterization of a nuclear protein that binds to three elements within the silencer region of a bean chalcone synthase gene promoter," Proc Natl Acad Sci USA 88:2515-2519 (1991); Loake, et al., "Combination of H-box CCTACC(N) 7 CT! and G-box (CACGTG) cis elements is necessary for feedforward stimulation of a chalcone synthase promoter by the phenylpropanoid-pathway intermediate p-coumaric acid," Proc Natl Acad Sci USA 89:9230-9234 (1992); and Yu, et al., "Purification and biochemical characterization of proteins which bind to the H-box cis-element implicated in transcriptional activation of plant defense genes," Plant J 3:805-816 (1993)) were not present in the IFR upstream region. EXAMPLE 2 Alfalfa IFR Promoter-GUS Fusions in Transgenic Plants The following example describes the fusion of IFR-derived promoters to a reporter gene so that the characteristics of the promoters may be determined. To use the promoters to control the expression of other genes, a similar procedure should be followed with modifications which will occur to one skilled in the art depending on factors such as the restriction sites available in the sequence of the gene of interest. Promoter sequences derived from the alfalfa IFR gene were fused to the β-glucuronidase gene in the binary vector pBI101.1 (Jefferson, et al., "GUS fusions: β-Glucuronidase as a sensitive and versatile gene fusion marker in higher plants," EMBO J 6:3901-3907 (1987)) as outlined in FIG. 2. Plasmids pAO1-1 and pAO4-1 contain overlapping regions of the IFR genomic clone. Digestion of the plasmid pAO1-1 yielded a 540 bp SpeI fragment containing 436 bp of the promoter region and 80 bp of the 5' untranslated region (EcoRI to SpeI site), along with 24 bases of the vector's multiple cloning site. Digestion of pAO4-1 yielded a 845 bp SpeI fragment containing an additional 329 bp of upstream promoter sequence. These two SpeI fragments were ligated into the XbaI site of pBI101.1 (Jefferson, et al., EMBO J 6:3901-3907 (1987)) to generate pAlf-ifrS-GUS and pAlf-ifrL-GUS, respectively. The two binary vectors were maintained in the E. coli strain DH5α u and then transferred to Agrobacterium tumefaciens strain LBA4404 by direct DNA transfer. (An, G., "Binary Ti vectors for plant transformation and promoter analysis," Methods Enzymol 153:292-305 (1987)). Transgenic plants transformed with the construct pAlf-ifrL-GUS, containing the longer (765 bp) promoter fragment, are referred to as "ifrL-GUS" plants. Similarly, transgenic plants transformed with pAlf-ifrS-GUS, containing the shorter promoter fragment (a 329 bp deletion to the EcoRI site within the longer promoter), are referred to as "ifrS-GUS" plants. Both constructs are transcriptional fusions to the GUS gene in which 80 nucleotides of the 92 nucleotide untranslated leader sequence of the IFR transcript were maintained intact. These two constructs, along with pBI121 (CaMV 35S promoter-GUS for constitutive expression controls) and pBI101.1 (as a control for GUS with no promoter) were introduced into tobacco and alfalfa plants by Agrobacterium-mediated plant transformation. Regenerated plants were shown to be transformed by Southern analysis using both a GUS-specific probe (BamHI/SacI fragment of pBI101.1) and an IFR-promoter-specific probe (the 845 bp SpeI fragment from pAO4-1). Border analysis indicated a range of 1 to 6 transgene copies in tobacco and 1 to 4 copies in alfalfa. Of eight ifrL-GUS independent tobacco transformants with the same qualitative GUS staining pattern, four plants (T8, T9, T11 and T14) showed higher levels of staining with X-gluc and were used in all studies. All seven independent transgenic tobacco plants obtained by transformation with the short promoter construct showed the same staining pattern as described below. In the case of alfalfa, all transgenic plants obtained by transformation with the long or short promoter constructs showed the same staining pattern. Three independent transformants that showed strong staining were selected to represent each promoter construct (A3, A4 and A7 for the long promoter and A8, A9 and All for the short promoter). EXAMPLE 3 Plant Transformation and Regeneration Tobacco and alfalfa plants were transformed with A. tumefaciens strain LBA4404 harboring the gene construct of interest by leaf disc methods. Transgenic tobacco plants (Nicotiana tabacum cv. Xanthi NF) were generated as described before (Rogers, et al., "Gene transfer in plants: Production of transformed plants using Ti plasmid vectors," Methods Enzymol 118:627-640 (1986)), with regeneration under kanamycin selection. Transgenic alfalfa plants were generated from the transformation and regeneration of competent alfalfa cultivar Regen SY (Bingham, E. T., "Registration of alfalfa hybrid Regen-SY germplasm for tissue culture and transformation research," Crop Sci 31:1098 (1991)), following a modified version of published procedures (Bingham, et al., "Breeding alfalfa which regenerates from callus tissue in culture," Crop Sci 15:719-721 (1975)). Briefly, leaf discs from young trifoliate leaves were inoculated with a suspension of Agrobacterium harboring the binary construct and incubated on solid B5h plates (Brown, O. C. W. and Atanassov, A., "Role of genetic background in somatic embryogenesis in Medicago," Plant Cell Tiss Organ Cult 4:111-122 (1985)) for four days (16 hours light at 24° C.). The explants were then washed twice with water to remove bacteria and incubated for four more days on new B5h plates. Explants were then washed twice with water and transferred to selection plates (B5h plates with 100 mg/L timentin (Smith-Kline Beecham, Philadelphia, Pa.) and 25 mg/L kanamycin (Sigma, St. Louis, Mo.)). Calli and occasional embryos appeared after two weeks and were transferred to new selection plates, making sure the calli were spread out. Plants were incubated for another week to allow development of additional embryos. The calli and embryos were then transferred to B5 plates (no hormones, but with antibiotics as before). After two weeks, the calli and embryos were transferred to fresh B5 plates (with antibiotics). After one to two weeks, individual embryos were cultured on MS plates (Murashige, T., and Skoog, F., "A revised medium for rapid growth and bioassays with tobacco tissue culture," Physiol Plant 15:473-497 (1962)) with antibiotics (50 mg/L timentin and 25 mg/L kanamycin); plantlets were formed within one to three weeks, occasionally with roots. These were transferred to plastic boxes (Magenta Corp, Chicago, Ill.) with MS agar media and antibiotics. Plants were maintained on MS media with antibiotics and propagated by cutting. Plants were also transferred to soil in the greenhouse. EXAMPLE 4 Characterization of IFR Promoter Activity Plant Material Two cultivars of alfalfa were used in this study, Medicago sativa cv. Apollo (AgriPro, Mission, Kans.) and cv Regen SY. (Bingham, E. T., Crop Sci 31:1098 (1991)). For good vegetative growth and induction of flowering, alfalfa plants were maintained at 18h/25° C. day and 6h/19° C. night cycles at approximately 70% relative humidity in controlled environmental chambers (Conviron, Asheville, N.C.). Tobacco plants were maintained in the greenhouse at 16h/25° C. day and 8h/20° C. night cycles at approximately 50% relative humidity. Callus and cell suspension cultures of alfalfa and tobacco were generated and maintained on modified SH media as described previously (Kessmann, et al., "Stress responses in alfalfa (Medicago sativa L.) III. Induction of medicarpin and cytochrome P450 enzyme activities in elicitor-treated cell suspension cultures and protoplasts," Plant Cell Rep 9:38-41 (1990)). Yeast cell wall preparations were used to elicit cell cultures as described previously. (Paiva, et al., Plant Mol Biol 17:653-667 (1991)). Nodulation and Pathogen Infection of Alfalfa Multiple cuttings of transgenic plants were rooted in autoclaved perlite wetted with filter-sterilized nitrogen-free Hoagland's nutrient solution supplemented with trace elements. After roots form (10 days), 5 ml of a suspension of Rhizobium meliloti 102F51 (OD 600 =0.5) was added to each cutting. Sterile water or nutrient solution was added as necessary to prevent the perlite from drying out. Nodulated roots were examined nine days, three weeks, and five weeks after inoculation. Growth chamber (Conviron, Ashville, N.C.) grown transgenic plants were either sprayed with a spore suspension (approximately 10 5 cfu/ml) of Phoma medicaginis in 0.05% Tween-20 or with dilute Tween-20 alone. Inoculated and control plants were then enclosed in clear plastic bags and grown under high humidity. Trifoliate leaves were taken at intervals of two, four and seven days and stained with X-gluc to detect GUS activity. DNA and RNA Gel Blot Hybridization DNA was isolated from tobacco and alfalfa plants as described. (Junghans, H., and Metzlaff, M., "A simple and rapid method for the preparation of total plant DNA," BioTechniques 8:176 (1990)). RNA was isolated as described in Paiva et al., Plant Mol Biol 17:653-667 (1991). Up to 10 μg of total RNA or genomic DNA was used in Northern or Southern blot analysis, respectively. Transfer of DNA or RNA to nylon membranes and hybridizations to specific probes were carried out as recommended in the manual (Preferred Method) supplied with Gene Screen Plus hybridization transfer membranes (DuPont, Boston, Mass.); changes to the hybridization and washing conditions were as described above for library screening. Probes were labeled to high specific activity by random primer labeling. (Feinberg, A. P., and Vogelstein, B., "A technique for radiolabeling DNA restriction endonuclease fragments to a high specific activity," Anal Biochem 137:266-267 (1984)). DNA Sequence Analysis DNA was sequenced by the Sanger dideoxy sequencing method. (Sanger, et al., Proc Natl Acad Sci USA 74:5463-5467 (1977)). A Taq DyeDeoxy Terminator Cycle Sequencing Kit (Applied Biosystems Inc., Foster City, Calif.) was used according to the manufacturer's protocol. The products were separated on a 6% polyacrylamide gel and the data processed by an ABI 373A automated DNA sequencer. All manipulations of raw data generated from the automated system were done on the PC Gene DNA analysis software (Intelligenetics, Mountain View, Calif.). Histochemical Localization and Fluorometric Quantitation of GUS Activity GUS activity was localized histochemically by standard protocols. (Jefferson, R. A., "Assaying chimeric genes in plants: The GUS gene fusion system," Plant Mol Biol Rep 5:387-405 (1987); and Martin, et al., "Non-destructive assay systems for detection of β-glucuronidase activity in higher plants," Plant Mol Biol Rep 10:37-46 (1992)). Typically, sectioned tissues or whole plant parts were incubated in 75 mM sodium phosphate (pH 7.5), 1-2 mM X-gluc (5-bromo-4-chloroindolyl-β-D-glucuronic acid) in 10% dimethylformamide, and 0.5% Triton X-100 for 6 to 12 hours at 37° C. The fluorescence of 4-methylumbelliferone produced by cleavage of 4-methylumbelliferyl-β-D-glucuronic acid was measured to quantitate GUS activity (Jefferson, R. A., Plant Mol Biol Rep 5:387-405 (1987)), which was expressed as pmoles 4-methylumbelliferone produced per min per mg of protein. Protein concentration was measured by the Bradford assay (Bradford, M. M., "A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding," Anal Biochem 72:248-254 (1976)) using the Biorad protein assay reagent. Transcriptional Activation of Isoflavone Reductase in Response to Elicitation To ensure that the increase in IFR transcripts observed upon elicitation of alfalfa cell cultures (Paiva et al., Plant Mol Biol 17:653-667 (1991)) was a result of increased transcriptional activation, steady state transcript levels were determined by Northern analysis and changes in IFR transcription by run-on analysis using isolated nuclei. The nuclei were isolated from frozen elicited alfalfa cells, and run-on transcription and transcript isolation procedures carried out as described by Ni and Trelease. (Ni, W., and Trelease, R. N., "Post-transcriptional regulation of catalase isozyme expression in cotton seeds," Plant Cell 3:737-744 (1991)). Slot blots were prepared using Gene Screen Plus hybridization membranes with 1 μg DNA per lane; the probe consisted of the 0.75 kb HindIII fragment of pIFRalf1. The data in FIG. 3 indicate that the massive increase in IFR transcripts observed 3 hours after exposure of cells to elicitor from yeast cell walls is preceded by a striking increase in transcription rate from an undetectable initial level. Approximately equal transcription rates were observed at 3 hours and 6 hours post-elicitation, but transcription had ceased by 12 hours post-elicitation. Essentially similar transcription kinetics, with a maximum at 3 hours, were observed for PAL (data not shown). Nuclear transcription run-on analyses have confirmed transcriptional activation of several plant defense response genes, including genes encoding the phenylpropanoid pathway enzymes PAL, 4-coumarate:CoA ligase (4-CL), CHS and chalcone isomerase (CM), in elicited cells. (Dixon and Harrison, Adv Genet 28:165-234 (1990)). In parsley cells, the kinetics of transcriptional activity of a range of elicitor-induced genes exhibited considerable variation, suggesting multiple mechanisms for defense gene activation. (Somssich, et al., "Differential early activation of defense-related genes in elicitor-treated parsley cells," Plant Mol Biol 12:227-234 (1989)). In the study to develop the present invention, the transcription kinetics of PAL, the first enzyme in the phytoalexin pathway, and IFR, the penultimate enzyme, were broadly similar, indicating that activation of PAL is not a prerequisite for induction of downstream enzymes. A detailed analysis of the very early activation kinetics (0 to 60 min) of medicarpin pathway genes has revealed nearly identical patterns for several of the genes examined, including those encoding PAL, CHS and IFR (W. Ni and R. A. Dixon, unpublished results). Developmental Expression of IFR Promoter-GUS Fusions in Transgenic Alfalfa Transgenic alfalfa plants were screened for observable GUS histochemical staining in roots. Both the long and the short promoter fragments conferred identical GUS expression. A zone of intense staining was seen in the region immediately behind the root tip, proximal to the quiescent center. The root cap and distal root meristematic region showed no GUS staining. Initiating lateral roots also showed high levels of GUS staining. Transverse sections through roots from both ifrL-GUS and ifrS-GUS plants revealed that GUS activity was localized exclusively to the inner cortex. This pattern of GUS expression is clearly different from that of the CaMV35S promoter in alfalfa roots, which is characterized by strongest GUS activity in the central vasculature and strong staining throughout the cortex and root tip, including the root cap. Transverse sections through stems of transgenic ifrL-GUS and ifrS-GUS alfalfa plants showed no detectable GUS activity. In comparison, transgenic plants obtained by transformation with pBI121 (35S promoter-GUS) showed staining in the vascular bundle, particularly in the secondary phloem. There was no histochemically detectable GUS activity in any shoot parts (stems, leaves, or petioles), flower parts including pollen, or seeds from ifrL-GUS or ifrS-GUS alfalfa plants, whereas pBI121-transformed plants showed intense staining in all tissues analyzed. Transformed plants containing pBI101.1 (promoterless GUS) did not show any detectable GUS activity. Expression of IFR Promoter-GUS Fusions in Alfalfa Root Nodules The effective Rhizobium meliloti strain 102F51 readily formed nodules on rooted cuttings of transgenic alfalfa. Histochemical analysis revealed a similar pattern of GUS expression in both ifrL-GUS and ifrS-GUS plants. In mature nodules (three and five weeks post-inoculation), the majority of the staining was in the proximal nodule meristem. No staining was observed in the distal meristematic region, the nodule outer cortex, or the region containing the mature, nitrogen-fixing bacteroids. In immature nodules, intense staining was observed across much of the inner, meristematic region. No staining was observed in nodules from plants transformed with pBI101.1 or from untransformed control plants. Inducibility of IFR Promoter-GUS Fusions in Alfalfa Transgenic ifrL-GUS and ifrS-GUS plants were inoculated with the alfalfa fungal leaf spot pathogen, Phoma medicaginis. Only infected leaves showed staining with X-gluc. GUS expression was very intense in a narrow zone (1 to 3 mm) around the lesions. HPLC analysis of portions of leaves similarly infected with P. medicaginis revealed that medicarpin accumulation is also confined to this zone. The staining intensity and pattern were identical with pathogen-infected leaves from both ifrL-GUS and ifrS-GUS plants, and strong staining was observed at two, four and seven days. Trifoliates of plants transformed with pBI101.1 did not stain after infection with P. medicaginis, whereas 35S-GUS plants showed decreased levels of staining on the trifoliates after pathogen infection. Wounding did not induce any observable GUS activity. Transgenic cell suspension cultures (from callus derived from leaves of transgenic alfalfa plants) were treated with a yeast cell wall-derived elicitor which is known to induce strong accumulation of medicarpin, while matched cultures treated with water were used as controls. (Paiva et al., Plant Mol Biol 17:653-776 (1991)). The transgenic lines harbored the ifr-L and ifr-S promoter GUS fusions, 35S-GUS, or promoterless GUS (pBI101.1). After 17 hours of incubation under standard growth conditions, staining with X-gluc was detected only in elicitor-treated cells. Quantitative fluorescence-based GUS assay results are given in FIG. 4 as GUS activity measured as picomoles of 4-methylumbelliferone per minute per milligram of protein. The designation following the construct name indicates from which independent transgenic line the suspension was derived. T he value indicated by each bar is the average of two independent GUS enzyme assays (standard deviation≦±7%. for unelicited and≦±2% for elicited cultures). The experiment was repeated with these same cell lines and additional cell lines, and similar levels of expression were obtained. As indicated in FIG. 4 an 8- to 13-fold increase in GUS activity was observed in elicited cell cultures derived from ifrS-GUS plants and a similar 10- to 12-fold induction was observed in cultures derived from ifrL-GUS plants. GUS expression in cell cultures from 35S-GUS and pBI101 transformed plants was not detectably induced by yeast elicitors. GUS activity in unelicited ifrL- and ifrS-GUS cultures was similar to that in 35S-GUS cultures; constitutive expression of the IFR promoter is expected under these conditions, as newly initiated alfalfa cell cultures constitutively accumulate significant amounts of MGM. (Kessmann, et al., "Stress responses in alfalfa (Medicago sativa L.) V. Constitutive and elicitor-induced accumulation of isoflavonoid conjugates in cell suspension cultures," Plant Physiology 94:227-232 (1990b)). Developmental Expression of Alfalfa IFR Promoter-GUS Fusions in Transgenic Tobacco The roots of ifrL-GUS tobacco plants had a distinct pattern of X-gluc staining; the strongest staining occurred as a discrete band, excluding the distal end of the root tip. A longitudinal section through such a root showed intense staining in the proximal meristem, and high levels of expression throughout the cortex behind this zone. The root cap, the developed vascular tissue and pith together with the quiescent center and protoderm did not stain. In contrast, expression of GUS in tobacco roots controlled by the CaMV35S promoter included the root tip. Transverse sections through roots of ifrL-GUS tobacco plants showed GUS activity uniformly spanning the entire cortex, with no staining in the epidermis and the central vascular cylinder. GUS expression was not detected in the roots of tobacco plants transformed with the promotor-less GUS construct pBI101.1. In contrast to transgenic alfalfa, no GUS expression was observed in the roots of any ifrS-GUS tobacco plants. Transverse sections through the stems of ifrL-GUS transgenic tobacco plants unexpectedly revealed GUS activity localized to the inner vascular cylinder, with parenchyma cells associated with the xylem vessels and primary xylem cells specifically being stained. The heaviest staining with X-gluc is seen through the entire central vascular cylinder in xylem, phloem and cambial cells. This is similar to the results obtained previously with the 35S promoter-GUS fusions in tobacco (Jefferson, et al., EMBO J 6:3901-3907 (1987)), and strongly contrasts with the expression pattern of the IFR promoter. Strong X-gluc staining associated with the vascular system was observed in petioles of young leaves specifically in the xylem tissue that is sandwiched between two arrays of phloem. There was very little or no staining in petioles from the lower one third of the plant. Expanding leaves expressed little GUS activity; when present, most of the staining was at the leaf tips. The area close to lateral emergences such as leaves and branches showed high levels of GUS activity. The heaviest staining was seen at stem peripheries in the regions above the points of attachment of the petioles. The shoot apical meristem did not express any GUS activity, whereas the region below the meristem was expressing GUS. This contrasts with the CaMV35S promoter, which was functional throughout the entire shoot apex. Unlike the ifrL-GUS plants, GUS activity was not detected in any vegetative organ or cell of ifrS-GUS tobacco plants. Plants that were generated by transformation with pBI101.1 were also GUS-negative. GUS activity was observed in various parts of flowers from transgenic ifrL-GUS tobacco plants. In the gynoecium of young flowers GUS activity was detected in the stigma and the placental tissue together with the base of the ovary and the flower receptacle. The style of mature, open flowers did not stain with X-gluc, but GUS activity was present in the style of flowers from all earlier stages. Ovules from different stages of unopened flowers did not stain, but occasional staining was seen in mature flowers. Whether fertilization is necessary for staining is not known, but is a possibility as cross sections through maturing fruits (formed after fertilization) showed staining of newly formed seeds. This could be developmentally controlled as there was no staining in the placental region, which had stained intensely in the mature flower. In the androecium of tobacco flowers, staining was observed in the tapetal tissue and pollen grains. Tobacco flowers from all ifrS-GUS plants showed staining in pollen, and fruits and seeds. The staining pattern is similar to that of ifrL-GUS flowers. No GUS activity was observed in the corolla of flowers of ifrL-GUS or ifrS-GUS plants. In comparison, in tobacco plants harboring the 35S promoter-GUS fusion, the entire flower expressed high levels of GUS activity, including the corolla. Inducibility of Alfalfa IFR Promoter-GUS Fusions in Tobacco Cell Cultures Transgenic cell suspension cultures from transgenic tobacco plants were treated with a yeast cell wall-derived elicitor which is known to induce strong accumulation of medicarpin, while matched cultures treated with water were used as controls. (Paiva et al., Plant Mol Biol 17:653-667 (1991)). The transgenic lines harbored the ifr-L and ifr-S promoter GUS fusions, 35S-GUS, bean CHS8-GUS, or promoterless GUS (pBI101.1). Quantitative fluorescence-based GUS assay results obtained after 17 hours of incubation under standard growth conditions are given in FIG. 5 as GUS activity measured as picomoles of 4-methylumbelliferone per minute per milligram of protein. The designation following the construct name indicates from which independent transgenic line the suspension was derived. The value indicated by each bar is the average of two independent GUS enzyme assays (standard deviation≦±4%). The experiment was repeated with these same cell lines and additional cell lines, and similar levels of expression were obtained. Treatment of cell suspension cultures generated from transgenic tobacco plants with yeast elicitor resulted in only a 2- to 3-fold increase in GUS activity for ifrS-GUS cell lines and a 3- to 4-fold increase in activity over unelicited cells for ifrL-GUS cell lines (FIG. 5). This was modest compared to the 10- to 12-fold increase in activity seen upon elicitation of a tobacco cell line transformed with a bean CHS8-GUS promoter construct. No consistent increase in GUS activity was detected when transgenic ifrL-GUS and ifrS-GUS tobacco plants were wounded, treated with a variety of tobacco or alfalfa fungal pathogens, infiltrated with Pseudomonas syringae pv syringae (successfully used to induce the CHS8 promoter in tobacco; Stermer, et al., Mol Plant-Microbe Interact 3:381-388 (1990)), treated with salicylic, arachidonic, or jasmonic acids (potential components of defense gene signal transduction pathways (reviewed by Lindsay et al., "Microbial recognition and activation of plant defense systems," Trends Microbiol 1:181-187 (1993)), or inoculated with tobacco mosaic virus (TMV) which forms local lesions on this tobacco strain. Cis-Elements Downstream of Position 330 are Sufficient for Developmental and Elicitor-Induced Expression of the IFR Promoter in Alfalfa Northern blot analysis (Paiva et al., Plant Mol Biol 17:653-667 (1991)) and in situ hybridization studies have shown that IFR transcripts are constitutively expressed in nodules and root cortical cells of alfalfa plants. This correlates with the accumulation of medicarpin malonyl glycoside in root tissues, and the histochemical localization of isoflavonoid accumulation in the root cortex of legumes with similar medicarpin conjugate accumulation. (Wiermann, R., "Secondary plant products and cell and tissue differentiation," In The Biochemistry of Plants, P. K. Stumpf and E. E. Conn, ed. (New York: Academic Press) 7:85-116 (1981)). The absence of IFR transcripts in the aerial organs of uninfected plants likewise reflects the absence of isoflavonoid compounds in these organs. The expression patterns observed with the 765 bp and the 436 bp IFR promoter-GUS fusions in transgenic alfalfa indicate that the promoter confers correct developmental expression in the homologous species, and that root/nodule expression is determined by sequences downstream of position 330. It is not known whether the distinctive lack of GUS staining in the region distal to the root apical meristem and cell proliferation zone reflects differences in isoflavonoid metabolism in the meristematic and quiescent regions of the root tip. The bean PAL promoter exhibits strong expression in the cell proliferation zone immediately adjacent to the root apical meristem in transgenic tobacco. (Liang, et al., Proc Natl Acad Sci USA 86:9284-9288 (1989)). In addition, the bean CHS8 promoter (Schmid, et al., "Developmental and environmental regulation of a bean chalcone synthase promoter in transgenic tobacco," Plant Cell 2:619-631 (1990)) is also expressed in this zone, in the root apical meristem, and in emerging lateral roots in a manner similar to that observed for the IFR promoter. It has been suggested that phenylpropanoid/flavonoid synthesis at the root apex may produce morphogenetic signals affecting polar auxin transport or exhibiting cytokinin-like activity (Liang, et al., Proc Natl Acad Sci USA 86:9284-9288 (1989)) based on observations of biological activities of flavonoids (Jacobs, M., and Rubery, P. H., "Naturally occurring auxin transport regulators," Science 241:346-349 (1988)), and dehydrodiconiferyl glucosides (Binns, et al., "Cell division promoting activity of naturally occurring dehydrodiconiferyl glucosides: do cell wall components control cell division?" Proc Natl Acad Sci USA 84:980-984 (1987)), respectively. Whether isoflavonoids have morphogenetic activity, or whether their synthesis at the root tip is related to rhizosphere phenomena, remains to be determined. Alfalfa nodules are indeterminant and maintain an active meristematic region under normal conditions. (Hirsch, et al., "Bacterial-induced changes in plant form and function," Int J Plant Sci 153:S171-Sl81 (1992)). The location of strongest GUS expression in nodules is in a tissue analogous to the strongest staining tissue in root tips, namely the proximal nodule meristem. Unlike many other legumes, alfalfa constitutively accumulates significant amounts of phytoalexin conjugates in roots and effective nodules (Paiva et al., Plant Mol Biol 17:653-667 (1991)). It is thought that the Rhizobium meliloti symbiont is either not sensitive to medicarpin (Pankhurst, C. E. and Biggs, D. R., "Sensitivity of Rhizobium to selected isoflavonoids," Can J Microbiol 26:542-545 (1980)) or the conjugated form, or the conjugation keeps the phytoalexin sequestered in the plant cell vacuoles away from the symbiont. We observed no evidence of promoter activity in the cells which contain the bacteroids, the actual N 2 -fixing form of the symbiont, suggesting that phytoalexin biosynthesis is not occurring in these cells. In transgenic alfalfa suspension cultures, the IFR promoter is strongly activated (up to 13-fold increase in GUS activity) in response to treatment with yeast elicitor, with basal expression in unelicited cells being equivalent to that of the constitutive 35S promoter. This increase in GUS activity is similar to the increase in IFR activity (10 to 12-fold) observed in elicited alfalfa cells (Paiva et al., Plant Mol Biol 17:653-667 (1991)). As elicitor responsiveness is not lost on deletion to position 330, the putative Box P-like element between positions 146 and 157 cannot be required for reception of the elicitation stimulus. Other than an incomplete Box P core sequence (CCAACA) at position 626 and some scattered homology near position 556, there are no sequence elements common to other elicitor-induced phytoalexin biosynthetic genes in the IFR promoter downstream of position 330. This suggests that, although IFR transcription is activated simultaneously with that of other defense genes, separate signalling pathways may exist for the activation of early- and late-pathway genes in response to elicitors. The Major Developmental Expression Pattern of the IFR Promoter in Transgenic Tobacco is Controlled by Sequences Upstream of Position 330 Tobacco does not possess the isoflavonoid branch of phenylpropanoid biosynthesis. Most previous studies in which correct developmental expression of a transgene has been reported in a heterologous species have involved promoters of genes whose products are common to both source and recipient of the transgene. (Benfey, P. N., and Chua, N. H., "Regulated genes in transgenic plants," Science 244:174-181 (1989)). The alfalfa IFR promoter is expressed in stem and floral tissues of tobacco according to a different developmental program from that seen in alfalfa. This difference is particularly striking in terms of the strong expression in tobacco stem and floral tissue. Although some features of this expression are similar to those of bean PAL and CHS transgenes, and tobacco IFR-like TP7 transcripts, in tobacco (Liang, et al., Proc Natl Acad Sci USA 86:9284-9288 (1989); Schmid, et al., Plant Cell 2:619-631 (1990); Drews, et al., "Regional and cell-specific gene expression patterns during petal development," Plant Cell 4:1383-1404 (1992)), there is a notable absence of IFR promoter expression in petal tissue. Furthermore, the elicitor-responsiveness of the promoter in transgenic tobacco cell suspensions was very poor compared to that of the bean CHS8 promoter. It is therefore possible that the IFR promoter is responsive to signals regulating the developmental programs of more than one differentially expressed endogenous tobacco gene which may or may not have defensive roles. The high constitutive expression in the aboveground parts of tobacco may also be due in part to the lack of specific negative regulatory factors in tobacco, which might normally suppress expression in these parts of alfalfa plants. Although the 765 bp IFR promoter conferred similar patterns of GUS expression in cortical cells and root meristems of tobacco and alfalfa, the cis-elements conferring this expression are different in the two cases, as deletion to position 330 abolishes root expression in tobacco but not in alfalfa. Identification of the sequences conferring root specificity must await a detailed mutational and deletional analysis of the promoter. During the analysis of promoters from several non-solanaceous, "nontransformable" species, investigators have relied on the use of promoter-deletion/reporter gene fusions expressed in tobacco to identify putative regulatory cis-elements (e.g., Burnett, et al., "Expression of a 3-hydroxy-3-methylglutaryl coenzyme A reductase gene from Camptotheca acuminata is differentially regulated by wounding and methyl jasmonate," Plant Physiol 103:41-48 (1993); Fritze, et al., Plant Cell 3:893-905 (1991); Liang, et al., Proc Natl Acad Sci USA 86:9284-9288 (1989); Mason, et al., "Identification of a methyl jasmonate-responsive domain in the soybean vspB promoter," Plant Cell 5:241-251 (1993); and Schmid, et al., Plant Cell 2:619-631 (1990)). Results indicate that data from such heterologous transformation experiments may be misleading. Constructs which yield ectopic expression (such as ifrL-GUS construct in stems, flowers, and seeds of the present invention) or which appear inactive in tobacco (such as ifrS-GUS construct in roots of the present invention) may exhibit correct developmental and stress-induced expression in the homologous system. __________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 1(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 2730 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: both(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:ACTAGTTTTGTAAGAATTTTTTGAAACTTGTGTAATCCAATATTAAAAAATGTAAAAAAA60AATGTTATCTTTTATACAAAACTTACCTTTTATGTTTCTTTAACTAATGCCTTAAAGATA120CCGATTAACATCCAATAATTAAATACCACCTAACATCAACAATTACAAAGAAATAACAAC180CTATTGAAACTCATTGCAAACGCTCTAACTTGCAAACTTTCTTTTGAGAAAGTATTTTTT240ATTTAACTTTCTAGGTGTTGAAGAACAATTTATGTTGAGTGAATATTAAACACATTTTTT300TATAATAGTTGAATCTATCAAATGAAGACGAATTCAACATGCAGGTTGGGTTGTGTCATT360GTTAAAAAGTTGTGAAGTAAAGGTTTCAAGTTGAATATTTAAAAAATCCTTAAAAAAGTT420ATATGTATATATCATGTTAATAATAATAATTAGTATAAATCGGTGTATTCTTTTGTTCTC480TTTGCTAAGATATATTCTTGCTTCCGGCCAAGTTTTCAGCAGAATTGTTTGATAAGTAGA540GTTTTTTTATATATATTTTAACTGACTACTAATATGTTTTATACGGAGTTAATTAAGTAG600ACTTAAGAGAAGGCGTCAATTTTGACCAACAGGGCTGCTTCTATTTCAACAACAATGAAT660ATTAAATTTGGTCACTAAAACACACAGAGAGTAGTAGATGGATTGAAGTTGGTGGCAATC720CAAGTTTGTCCTATAAATATCAAACAAAGTATAGCTATTCATCACACACTCACTACTACT780TTGGTAACGTATTCAAAACAAGAAAAAACAGACAAAAACATAAACACACTTGTTTTTTTA840CTAGTTATTTTTTTCCAATGGCAACTGAAAACAAAATCCTGATCCTAGGACCAACAGGAG900CTATTGGAAGACACATAGTTTGGGCAAGTATTAAAGCAGGAAATCCAACATATGCTTTGG960TTAGAAAAACACCTGGCAATGTTAACAAGCCAAAGCTTATTACAGCTGCTAATCCTGAAA1020CCAAGGAAGAGCTTATTGATAATTACCAATCTTTAGGAGTTATTCTACTTGAAGTAAGTG1080ATTTCAATATGTGAAATAATTTTATATTCTATATATTTATTAAATTGACCTAATCAATAT1140GTCTTTGACTCTGCAGGGTGATATAAATGATCATGAAACTCTTGTTAAGGCAATCAAGCA1200AGTTGACATTGTGATCTGTGCTGCTGGTAGACTACTAATTGAAGATCAGGTCAAGATTAT1260TAAAGCAATTAAAGAAGCTGGAAACGTTAAGGTGAACAAATTTGTCACTACACCAGTAAA1320TAAGTCCAAATAAGTCAATTCATATAGAGTCTTAGTTAGTAATAACTCTTTGATGGTTAG1380ATTTGTACTCGTTATATTGAATAGTGGTACTAAATTTCTTGTGTCGACAGAAATTTTTCC1440CATCTGAATTTGGGCTAGACGTGGACCGTCATGAGGCCGTTGAGCCAGTTAGACAAGTTT1500TTGAAGAAAAAGCAAGTATCCGAAGAGTAATTGAAGCCGAAGGAGTTCCTTACACTTACC1560TTTGTTGCCACGCCTTTACCGGTTACTTCTTACGTAACTTGGCTCAACTCGACACAACTG1620ATCCTCCTCGGGACAAAGTTGTCATTCTTGGAGATGGAAATGTGAAAGGTAACAGACTTA1680GTCACAGAACAATTCAACAAACTAGTATTGAACAAAAGACACACAATTCAGTTGTTTCAA1740TAATTATACCTTACTCATTTCAGGAGCATATGTAACTGAGGCTGATGTGGGAACTTTTAC1800CATTAGAGCAGCAAATGATCCCAACACATTGAACAAAGCTGTCCATATTAGACTCCCCGA1860AAATTATTTGACCCAAAATGAGGTCATTGCCCTTTGGGAGAAAAAGATTGGGAAGACTCT1920TGAGAAAACTTATGTTTCAGAGGAACAAGTTCTCAAGGATATTCAAGGTCAGTAAAATAA1980ACGCTTTATAAATATTGTTAAGAATTTTTACACCGGTAATCAATCATAGTTGATAAATCG2040TTAAAAATATTTGATTTTAATTATATCTATTTTAATGACCGCACAAATATCTGACGGTGT2100ATCAAAATTAATCTCTTAGTGTTAAATTATGAGTGACATGTATGTCATTTTACAGCAATT2160TTGTAAAATTAATCATGAAATATGTTACTTGCTATGCAGAATCTTCATTCCCTCATAACT2220ATTTGTTGGCATTGTACCATTCACAACAAATAAAAGGAGATGCAGTGTATGAGATTGATC2280CAGCCAAAGATATTGAAGCTTCTGAAGCCTATCCAGATGTGACATACACCACTGCTGATG2340AATATTTGAATCAATTTGTCTAACGAATGCTAAGGAAATGTTCAATAAGACAATGAATTT2400AAAAAAAAAAAAGTTTCACATCTGTGTATGTTTCTTGTGTTTGTTTAGTTTTGTTCTCAG2460TAATCCCTCCCAATTGATGTAATAATTTACAAAAATAATAAATATTATATTCTGTTCCAC2520TGTTTGCACATCTTTGTCTCTTTGTTCAATATTTTACATTGTGGCTTCTCATTTTATGCG2580TCACTGTGAAGGGCCGACTCCAAAAATAATTAAACGCACGCCCAAAATGGACTGAAAAAT2640TCACTAATTAGACAAGTAGAAATATAATAAGAACTGAAATAATGACGAAAAAAAAATAAG2700AACTAAAAAAAATAGAAATATTAGGAATTC2730__________________________________________________________________________

The invention relates to a promoter and associated control elements derived from the isoflavone reductase gene. The upstream activating region and portions thereof have been characterized as to their ability to control the transcription of operably linked foreign structural genes in legumes as well as in plants which lack the isoflavonoid pathway.

[0001] The invention relates to the use of a family of new synthetic triamine compounds which can be used in pharmaceutical compositions such as antivirals. BACKGROUND OF THE INVENTION [0002] The number of biologically active compounds useful as antivirals is very limited. Particularly limited are anti-HIV agents. Currently approved anti-HIV drugs include nucleoside analogs such as AZT. Unfortunately, recent results of a European trial of AZT in asymptomatic HIV-infected persons showed that administration of the drug caused no difference in survival after three years. In the face of slow progress on the development of an effective AIDS vaccine, a National Task Force on AIDS Drug Development has been established to explore new approaches to AIDS chemotherapy. [0003] It is unlikely that a cure for AIDS will be discovered because HIV integrates itself into the host's genome and the main strategy to combat the disease is to keep the HIV virus from proliferating. At least 16 steps in the HIV life cycle have been identified as possible points for therapeutic intervention, yet all of the anti-HIV drugs licensed in the U.S. so far (AZT, ddI and dd) are nucleoside inhibitors of HIV reverse transcriptase (RT). Rapid mutation of the virus presents a key challenge to antiretroviral drug therapy and AZT-resistant strains of HIV appear in patients after prolonged treatment. Non-nucleoside RT inhibitors are currently under investigation, but it is expected that combinations of drugs operating by different mechanisms will combat viral resistance most successfully. Hence, there is an urgent search for new drugs acting at different stages in the HIV life cycle. More recently discovered anti-HIV agents include certain bicyclams and quinolines such as quinoline-4-amine. The mechanism of action of the quinoline compound is unknown, but the bicyclams are reported to be inhibitors of HIV uncoating. [0004] Another type of compound, the triaza macrocycles, have been used primarily for metal complexation. Previously, no biological activity has been suggested for these compounds. SUMMARY OF THE INVENTION [0005] The present invention provides a family of triaza compounds which show antiviral properties for use against a number of viruses including HIV-1 and HIV-2. [0006] The basic structure of the compounds is represented by formula I: [0007] wherein [0008] w represents a bridge carbon which is additionally bonded to at least one polar or non-polar side group substituent selected from the group consisting of double-bonded carbon, double bonded oxygen, hydroxyl, alkyl of about one to 10 carbons, alkoxy of about one to 10 carbons, aryl of about 7 to 10 carbons, a halogen, methyl halogen, methylene halide, epoxide (or oxirane), acyl, CH 2 OH and hydrogen; halogen is F, Cl, I or Br; halide is F 2 , Cl 2 , I 2 or Br 2 . [0009] X and Y independently represent an aromatic group, an alkyl group, a sulfonyl group or a carbonyl group said aromatic group selected from the group consisting of Ar, Ar sulfonyl, Ar carboxy and Ar alkyl where Ar is an aromatic cyclic or heterocyclic ring having from five to seven members. The alkyl group which may be present for X and Y or as a substituent on Ar has from one to ten carbons. X and Y are not both an alkyl group. Preferably at least one of X or Y is an aromatic group. [0010] Z represents a group listed for X and Y or a fused aryl moiety; said aryl moiety having from seven to ten carbons. Z may also represent hydrogen. [0011] a and d independently represent a number from zero to 10; b and c independently represent a number from one to 10; and e represents a number from zero to three; and preferably, a+d+e≧1. Formula I represents a cyclic or acyclic structure and contains sufficient hydrogens for a stable molecule. Moieties for C a and C d can include double bonds particularly when the structure for formula I is acyclic. [0012] In one preferred embodiment, W is ethene, X and Y are tosyl, Z is benzyl or —COR 2 , a, d, and e are one, and b and c are three. [0013] The compounds of formula I have antiinfective activity and have a range of uses including as a pharmaceutical agent for use in the prevention and chemoprophylaxis of viral illnesses. The compounds can also be used as an antiinfective or antiseptic as a coating or additive on articles such as medical devices, contraceptives, dressings, and in blood product preparations and similar biologicals. [0014] A method of inhibiting a virus comprises contacting the virus, a virus-containing milieu, a virus-infectable cell or a virus-infected cell with a virus-inhibiting amount of the compound of formula I. DETAILED DESCRIPTION [0015] The compounds are characterized as having at least three nitrogen atoms (amine sites) linked by at least two alkylene bridges or linking groups to form triamines. The alkylene bridge linking groups are preferably alkanes containing from one to ten carbons. [0016] The triamines may be formed into a triazamacrocycle by a third alkylene bridge which is preferably alkane having from one to ten carbons connecting the two end nitrogens of the triamine compound. [0017] The alkylene bridges linking the nitrogen atoms can additionally include aromatic or non-aromatic rings fused to the alkylene bridge. Bridges containing fused rings and linking two nitrogens of the triamine structure may be exemplified by the following: [0018] The alkylene bridges are preferably —(CH 2 ) 3 —. [0019] The bridge carbon (designated W) of the third alkylene bridge may be functionalized with (i.e., bonded to) a side substituent which is a polar group. [0020] Representative groups for W include [0021] (halo is F, Cl, Br or I). W may also be unfunctionalized, i.e., bonded to hydrogen. W is preferably [0022] X and Y are independently an aromatic, alkyl, sulfonyl or carbonyl group or hydrogen. Representative aromatic groups include five or six membered rings which may have heteroatoms of nitrogen, oxygen or sulfur. The rings include, for example, phenyl, pyrrolyl, furanyl, thiophenyl, pyridyl, thiazoyl, etc. The aromatic group (Ar) for X and Y may be substituted with a hydrophilic group. Preferably the Ar is substituted with NO, NO 2 , NH 2 , NHR, NHR 2 , OH, OR, SH, SR, SOR, SO 3 R, halo, C(halogen) [0023] where R is alkyl of one to 10 carbons; R is preferably alkyl of one to three carbons; R is more preferably methyl. The aromatic groups are more preferably further substituted with sulfonyl, carboxy, alkyl of one to 10 carbons or amino. Representative of groups for X and Y are [0024] where, e.g., R is alkyl of 1 to 10 carbons, and R 2 is amino, nitro, sulfhydryl, hydroxy, alkoxy of one to three carbons, acetamino or methyl. [0025] The alkyl groups for X and Y may be branched or unbranched and include up to ten carbons. Typical examples of alkyl groups for X and Y include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl. The alkyl groups may be in whole or in part in the form of rings such as cyclopentyl, cyclohexyl, cycloheptyl and cyclohexylmethyl. The cyclic groups may be further substituted with alkyl or aryl groups. [0026] Preferably, X and Y both contain aromatic groups. More preferably, X and Y are both tosyl: [0027] The groups for Z are the same as for X and Y or a fused aryl moiety. Fused rings for the Z position include naphthalene, phenanthrene, anthracene, indole, quinoline, isoquinoline, carbazole, benzimidazole and benzofuran. Z is preferably an unfused group, more preferably benzyl. [0028] All groups for W, X, Y and Z may be further substituted with polar substituents such as NH 2 , NO, NO 2 , SH, SO 3 H, OH, and CO 2 H. These polar groups are capable of aiding solubility of the compounds. [0029] Representative compounds include [0030] 3-Methylene-1,5-ditosyl-1,5,9-triazacyclododecane [0031] 5,9-Ditosyl-7-hydroxymethyl-1,5,9-triazabicyclo-[5,5,0] tridecane [0032] 5,9-Ditosyl-13-oxa-1,5,9-triazatricyclo[5,5,1 1.7 , 1 7,12 ]-tetradecane [0033] 9-Benzyl-3-hydroxymethyl-1,5-ditosyl-1,5,9-triazacylododecane [0034] 9-Benzyl-3-chloromethyl-1,5-ditosyl-1,5,9-triazacyclododecane [0035] 3-Chloromethyl-1,5-ditosyl-1,5,9-triazacyclododecane N,N-bis(3-toluenesulfonamidopropyl) toluenesulfonamide [0036] 1,5,9-Tritosyl-1,5,9-triazacyclododecane [0037] 3-Methylene-1,5,9-tritosyl-1,5,9-triazacyclododecane [0038] 3-Hydroxymethyl-1,5,9-tritosyl-1,5,9-triazacyclododecane [0039] 3-Chloromethyl-1,5,9-tritosyl-1,5,9-triazacylododecane [0040] 11-Methylene-1,5,9-triazabicyclo[7,3,3] pentadecane [0041] 1,5,9-Triazabicyclo[9,1,1]tridecane [0042] 9-Benzyl-3-keto-1,5-ditosyl-1,5,9-triazacyclododecane [0043] 9-Benzyl-3-methyl-1,5-ditosyl-1,5,9-triazacyclododecane [0044] 9-Benzyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane-9-oxide [0045] 9-Acyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane [0046] 9-Alkyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane [0047] 9-Acyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane epoxide [0048] 9-Benzyl-1-formyl-3-methylene-1,5,9-triazacyclododecane [0049] 9-Benzyl-1-formyl-3-methylene-5-tosyl-1,5,9-triazacyclododecane [0050] 9-Benzyl-3-methylene-1-tosyl-1,5,9-triazacyclododecane [0051] 9-Benzyl-3-methylene-1-acyl-5-tosyl-1,5,9-triazacyclododecane [0052] 9-(Ethoxycarbonyl)-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane [0053] N-Benzylbis(3-benzenesulfonamidopropyl)amine [0054] 9-Benzyl-3-methylene-1,5-dibenzenesulfonyl-1,5,9-triazacyclododecane [0055] N-Benzylbis[3-(N′-2-propenyltoluenesulfonamido) propyl]amine dihydrogen sulfate [0056] N-Benzyl-N-[3-(N′-2-methyl-2-propenyl-toluenesulfonamido)propyl]-N-(3-toluenesulfonamido-propyl)amine dihydrogen sulfate [0057] N-Benzylbis[3-(N′-2-methyl-2-propenyltoluene-sulfonamido)propyl]amine dihydrogen sulfate. [0058] The compounds of this invention possess valuable pharmacological properties for both human and veterinary medicine. The compounds display antiviral and antitumor effects and are useful particularly in the prevention and chemoprophylaxis of viral illnesses. [0059] The compounds can also be used in vitro and employed in admixture with carriers, germicides, fungicides, or soaps, etc., for use as antiseptics solutions and the like, particularly in conjunction with hospital housekeeping procedures to combat viruses such as herpes and HIV. They are also useful as intermediates in the production of other polyamine drugs by the method of U.S. Pat. No. 5,021,409 and in the synthesis of metal chelating compounds, e.g., by methods of Bradshaw et al., Aza-Crown Macrocycles , Wiley, New York, 1993. [0060] The pharmacologically active compounds of this invention can be processed in accordance with conventional methods of pharmacy to produce medicinal agents for administration to patients, e.g., mammals including humans. The pharmacological compounds of the invention are generally administered to animals, including but not limited to mammals and avians; more preferably to mammals including humans, primates and avians including poultry. [0061] The compounds of this invention can be employed in admixture with conventional pharmaceutically acceptable diluents, excipients, carriers and other components such as vitamins to form pharmaceutical compositions. [0062] Pharmaceutical compositions may be prepared by known principles for parenteral, enteral and topical application. Preferably, the administration is parenteral. [0063] Generally, the compounds of this invention are dispensed in unit dosage form comprising 10 to 1000 mg in a pharmaceutically acceptable carrier per unit dosage. The dosage of the compounds according to this invention generally is about 0.1 to 100 mg/kg body weight/day preferably 0.1 to 20 mg/kg/day when administered to patients, e.g., humans to treat viral infections such as HIV. [0064] Viruses share certain common characteristics; they consist of a nucleic acid genome which may be double-stranded DNA, single stranded DNA, single-strand positive RNA, single-strand negative RNA and double-stranded RNA. The nucleic acid is surrounded by protective protein shell (capsid) and the protein shell may be enclosed in an envelope which further includes a membrane. [0065] The treatment of viral disease has been approached by inhibiting absorption or penetration of virus into cells, inhibiting intracellular processes which lead to the synthesis of viral components, or inhibition of release of newly synthesized virus from the infected cell. The inhibition of one or more of these steps depends on the chemistry or mode of action of the virus. [0066] The compounds of the invention have been shown to have antiviral effect against various viruses including retroviruses, particularly HIV which researchers believe to be a positive strand RNA virus. Effectiveness has also been shown against other viruses which infect humans including cytomegalovirus and herpesvirus which are believed to be double strand DNA viruses, influenza virus which is believed to be a negative strand RNA virus, and also rous sarcoma virus which infects avians. The invention will be illustrated by the following non-limiting examples. I.A. Synthesis of Compounds 1 and 2 [0067] The synthesis of N-benzylbis(3-toluene-sulfonamidopropyl)amine (compound 2) and 9-benzyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclodecane (CADA) (compound 1) is shown in Scheme 1. [0068] a. Bis(2-cyanoethyl)amine [0069] Into a 1-L three-necked round-bottomed flask equipped with an addition funnel, a dry-ice/acetone-cooled Dewar condenser, thermometer, and nitrogen inlet, was added 354 g (6.7 mol) of acrylonitrile. The addition funnel was charged with 208 mL (3.2 mol) of concentrated ammonium hydroxide, the apparatus was flushed with nitrogen and the acrylonitrile was preheated to 70-75° C. by means of an 80° C. oil bath. The ammonium hydroxide was added dropwise to the vigorously stirred reaction mixture over a period of 2 h. Afterwards, the reaction mixture was stirred without external heating for 30 min., then heated to 70-75° C. by means of a 75° C. oil bath for an additional 30 min. The excess acrylonitrile and most of the water were removed by rotary evaporation and the residue was dried to constant weight under vacuum (0.5 mm Hg). The resulting yellow oil (387 g, 99%) was sufficiently pure to be used directly in the next step, but can be distilled under vacuum, bp 186-190° C. (15 mm). 1 H NMR (CDCl 3 ) δ 2.86 (t, J=6.6 Hz, 4 H), 2.44 (t, J=6.6 Hz, 4 H), 1.5 (br, 1 H). 13 C NMR (CDCl 3 ) δ 118.4, 44.4, 18.8. IR (film, cm −1 ) 3330 (s), 2920 (s), 2850 (s), 2240 (s), 1440 (s), 1415 (s) 1360 (m), 1130 (s), 750 (br). [0070] b. N-Benzylbis(2-cyanoethyl)amine [0071] A mixture of 50.0 g (0.406 mol) of bis(2-cyanoethyl)amine, 51.45 g (0.406 mol) of benzyl chloride, 1.0 g (6.7 mmol) of sodium iodide, 22.05 g (0.208 mol) of sodium carbonate and 150 mL of acetonitrile was stirred mechanically and heated at reflux under nitrogen for 5 h. The cooled reaction mixture was filtered and the solids were washed with acetonitrile (3×50 mL). The combined filtrates were concentrated by rotary evaporation. A solution of the residue in 100 mL of CH 2 Cl 2 was washed with saturated aqueous Na 2 S 2 O 3 (2×20 mL) and saturated aqueous NaCl (2×50 mL). The combined aqueous layers were extracted with CH 2 Cl 2 (3×30 mL). The combined CH 2 Cl 2 solutions were dried over MgSO 4 , filtered and concentrated by rotary evaporation. The residual solvent was removed under vacuum (0.5 mm), yielding 70.4 g (89%) of product as a light yellow oil. 1 H NMR (CDCl 3 /TMS) δ 7.34 (m, 5 H), 3.70 (s, 2 H), 2.88 (t, J=6.8 Hz, 4 H), 2.44 (t, J=6.8 Hz, 4 H). 13 C NMR (CDCl 3 ) δ 137.5, 128.3, 127.4, 118.4, 57.7, 49.1, 16.4. IR (film, cm −1 ) 3070 (w), 3050 (m), 3020 (s), 2930 (s), 2830 (s), 2240 (s), 1595 (m), 1575 (w), 1485 (s), 1445 (s), 1415 (s), 1360 (br), 1250 (br), 1125 (s), 1070 (s), 1020 (s), 960 (s), 730 (s), 690 (s). [0072] c. N-benzylbis(3-aminopropyl)amine [0073] A mixture of 43.3 g (0.203 mol) of N-benzylbis(2-cyanoethyl)amine, 7.8 g of a 50% aqueous slurry of Raney nickel and 90 mL of a 1.4 M solution of NaOH in 95% ethanol was hydrogenated in a Parr apparatus for 48 h. The catalyst was removed by filtration and washed with 80 mL of 95% ethanol. The combined filtrates were concentrated by rotary evaporation. A solution of the residue in 100 mL of hexane/chloroform (1:1, v/v) was dried over Na 2 SO 4 , filtered and concentrated by rotary evaporation. Removal of solvent residues under vacuum (0.5 mm) afforded 40.3 g (90%) of product as a yellow oil. 1 H NMR (CDCl 3 /TMS) δ 7.31 (m, 5 H), 3.52 (s, 2 H), 2.70 (t, J=6.8 Hz, 4 H), 2.45 (t, J=6.8 Hz, 4 H), 1.60 (quint., J=6.8 Hz, 4 H), 1.26 (s, 4 H). 13 C NMR (CDCl 3 ) δ 139.5, 128.3, 127.7, 126.3, 58.3, 50.9, 40.0, 30.6. IR (film, cm −1 ) 3360 (br), 3270 (br), 3070 (w), 3050 (w), 3020 (m), 2920 (br. s), 2850 (s), 2800 (s), 1600 (s), 1485 (s), 1450 (s), 1360 (m), 1110 (br), 1070 (m), 1020 (m) 730 (m), 690 (m). [0074] d. N-Benzylbis(3-toluenesulfonamidopropyl)amine (compound 2) [0075] A solution of p-toluenesulfonyl chloride (20 g, 105 mmol) in 50 mL of CH 2 Cl 2 was added dropwise with vigorous stirring over 2 h to a solution of N-benzylbis(3-aminopropyl)amine (11.07 g, 50 mmol) and NaOH (4.4 g, 110 mmol) in 30 mL of water. After stirring for an additional hour, the organic layer was separated, washed with equal volume of brine, dried over MgSO 4 , and concentrated by rotary evaporation. Attempts to crystallize the crude oily product were not successful. All remaining solvent was removed under high vacuum and the product (25.1 g, 95w) was used without further purification. 1 H NMR (CDCl 3 /TMS) δ 7.70 (d, J=8.2 Hz, 4 H, TsH 2,6 ), 7.28 (d, J=8.2 Hz, 4 H, TSH 3.5 ), 7.24 (m, 5 H, Ph), 5.80 (br, 2 H, NH, 3.43 (s, 2H, PhCH 2 ), 2.92 (t, J=6.2 Hz, 4 H, Ts-NCH 2 ), 2.45 (m, 4 H, Bn-N-CH 2 ), 2.42 (s, 6 H, TsCH 3 ), 1.64 (quint., J=6.3 Hz, 4 H, NCH 2 CH 2 ). 13 C NMR (CDCl 3 ) δ 143.1, 136.9, 129.6, 129.0, 128.4, 127.3, 127.0, 58.6, 51.8, 42.2, 25.9, 21.4. IR (film, cm −1 ) 3280, 3050, 3020, 2940, 2850, 2810, 1595, 1490, 1450, 1320, 1150, 1085, 810, 730, 690, 660. [0076] The compound 9-benzyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclodecane (CADA) (compound 1) was synthesized in the following manner. [0077] e. 9-Benzyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane (CADA) (Compound 1) [0078] Sodium hydride (3.6 g, 144 mmol, washed with hexane prior to use) was added under nitrogen to a solution of the product of procedure d., N-benzylbis(3-toluenesufonamidopropyl)amine (26.5 g, 50 mmol) in 500 mL of DMF. The mixture was held at 80-100° C. for 1 h then cannulated through a glass filter under N 2 into a 2-L three-necked round-bottomed flask equipped with a rubber septum, a thermometer, and an inlet for N 2 . An additional 500 mL of DMF was used to insure complete transfer. The solution was stirred at 100° C. as a separate solution of 3-chloro-2-chloromethyl-1-propene (6.25 g, 50 mmol) in 50 mL of DMF was added over 9 h by means of a syringe pump. Upon completion of the addition, stirring at 100° C. under N 2 was continued an additional 12 h. The solvent was removed completely on a rotary evaporator using a hot water bath. A solution of the residue in 150 mL of CHCl 3 was washed with water, dried over MgSO 4 and concentrated by rotary evaporation. A solution of the resulting sticky, yellow crude product in a minimum volume of hot toluene was mixed with hexane to precipitate side-products. The supernatant solution was decanted and the residue was triturated with hexane several times. The combined supernatants were concentrated by rotary evaporation. The resulting residue was dried in vacuo and recrystallized from chloroform/ethanol, yielding CADA (16 g, 55!k) as a white solid, mp 156-158° C. 1 H NMR (CDCl 3 /TMS) δ 7. 66 (d, J=8 Hz, 4 H, TSH 2,6 ), 7. 31 (d, J=8 Hz, 4 H, TSH 3,5 ), 7.20 (m, 5 H, Ph), 5.23 (s, 2 H, C═CH 2 ), 3 .84 (s, 4 H, allylic), 3.39 (s, 2 H, PhCH 2 ) , 3.12 (t, J=6.8 Hz, 4 H, Ts-NCH 2 ), 2.44 (s, 6 H, TsCH 3 ), 2.36 (t, J=6 Hz, 4 H, Bn-N-CH 2 ), 1.63 (quint., J=6 Hz, 4 H, NCH 2 CH 2 ). 13 C NMR (CDCl 3 ) δ 143.4, 139.3, 138.3, 135.5, 129.7, 128.7, 128.1, 127.2, 126.9, 116.2, 59.0, 51.0, 49.5, 44.0, 24.4, 21.5. IR (film, cm −1 ) 3020, 2940, 2920, 2850, 2800, 1600, 1490, 1450, 1330, 1150, 1080. Anal. calcd. for C 31 H 39 N 3 S 2 O 4 : C, 64.00; H, 6.76; N, 7.22; S, 11.02. Found: C, 63.91; H, 6.65; N, 7.13; S, 11.04. I.B. Synthesis of Compounds 210 and 211 [0079] 210 N-Benzylbis (3 -benzenesulfonamidopropyl) amine and 211 9-Benzyl-3-methylene-1,5-dibenzenesulfonyl-1,5,9-triazacyclododecane were synthesized as follows: [0080] a. N-Benzylbis (3 -benzenesulfonamidopropyl) amine (Compound 210) [0081] HCl Salt. [0082] Into a 1-L round-bottomed flask equipped with an addition funnel, a stirring bar and a nitrogen inlet, were added 40.2 g(0.23 mol) of benzenesulfonyl chloride, 150 mL of ether and 175 mL of a saturated aq. NaCl solution. The addition funnel was charged with a solution of 25.4g (0.12 mol) of N-benzylbis(3-aminopropyl)amine and 175 mL of 1.3 N aq. NaOH. The amine was added dropwise with vigorous stirring over 2 h. The mixture was poured into a separatory funnel and the aqueous portion (bottom layer) removed. The two organic layers were diluted with 100 mL of chloroform and the resulting solution concentrated by rotary evaporation to a pale yellow oil. The residue was dissolved in 150 mL of dichloromethane. A solution of 2 N aq. HCl (60 mL) and 60 mL of saturated aq. NaCl was added and the mixture was stirred vigourously for 1 h. The layers were separated and the organic (lower) layer was washed with a saturated aq. NaCl solution (3×50 mL) and concentrated by rotary evaporation. The residue was recrystallized by bringing an ethanol solution of the residue to a boil and adding ethyl acetate to induce precipitation. The mixture was cooled to room temperature then to −25° C. for 2 weeks. Vacuum filtration of the precipitate gave 55.9 g (90%) of N-benzylbis(3-benzenesulfonamidopropyl)amine hydrochloride as a white solid. An analytical sample was prepared by drying at 65° C. (1 mm) for 13 h, mp 135-136° C. 1 H NMR (DMSO-d 6 ) δ 11.0 (br, 1 H, BnNH), 7.89 (t, 2 H, J=5.7 Hz, SO 2 NH), 7.79 (d, 4 H, J=7.2 Hz,SO 2 ArH 2,6 ), 7.59(m, 8 H, SO 2 ArH 3,4,5 , BnArH 3,5 ), 7.41 (m, 3 H, BnArH 2,4,6 ), 4.23 (d, 2 H, J=4.2 Hz, PhCH 2 N), 2.93 (m, 4 H, ArSO 2 NCH 2 CH 2 ), 2.74 (m, 4 H, BnNCH 2 CH 2 ), 1.88 (m, 4 H, NCH 2 CH 2 CH 2 N). 13 C NMR (DMSO-d 6 ) δ 140.3, 132.6, 131.5, 129.8, 129.6, 129.4, 128.9, 126.6, 56.0, 49.4, 40.1, 23.3. IR (KBr, cm −1 ) 3242 (br), 3073 (s), 2976 (m), 2855 (m), 2609 (s), 1470 (m), 1446 (s), 1330 (s), 1163 (s), 1092 (s), 740 (s), 689 (s). Anal. calc. for C 25 H 31 N 3 S 2 O 4 HCl; C, 55.80; H, 5.99; N, 7.81; S, 11.92; Cl, 6.59. Found: C, 55.47; H, 6.13; N, 7.63; S, 11.63; Cl, 6.92%. [0083] Free Base. [0084] In a round-bottomed flask equipped with a magnetic stir bar, 6.51 g (12.1 mmol) of N-benzylbis(3-benzenesulfonamidopropyl)amine hydrochloride, 40 mL of CH 2 Cl 2 , 15 mL of a solution of 1 N aq. NaOH and 15 mL of saturated aq. NaCl were combined. After stirring vigorously for 30 min, the layers were separated and the organic portion dried (MgSO 4 ). Removal of the drying agent by filtration, concentration of the filtrate by rotary evaporation and further drying under vacuum (0.4 mm, 45° C.) for 24 h afforded 5.96 g (98%) of N-benzylbis (3-benzenesulfonamidopropyl)amine as a thick colorless oil. TLC (silica): R f =0.21, 1:1 (v/v) ethyl acetate:hexane. 1 H NMR (CDCl 3 /TMS) δ 7.82 (d, 4 H, J=7 Hz,SO 2 ArH 2,6 ), 7.51 (m, 6 H, SO 2 ArH 3,4,5 ), 7.22 (m, 3 H, BnArH 2,4,6 ), 7.16 (m, 2 H, BnArH 3,5 ), 5.9 (br, 2 H, SO 2 NH), 3.40 (s, 2 H, PhCH 2 N), 2.92 (t, 4 H, SO 2 NCH 2 CH 2 ), 2.38 (t, 4 H, BnCH 2 CH 2 ), 1.62 (quint, 4 H, NCH 2 CH 2 CH 2 N). 13 C NMR (CDCl 3 ) δ 139.9, 138.2, 132.4, 129.0, 128.4, 127.2, 126.9, 58.7, 51.8, 42.2, 26.1. IR (NaCl plate, cm −1 ) 3277 (br), 3061 (w), 1446 (s), 1325 (s), 1160 (s), 1093 (s). [0085] b. 9-Benzyl-3-methylene-1,5-dibenzenesulfonyl-1,5,9-triazacyclododecane (Compound 211). [0086] In a 500 mL three-necked round-bottomed flask equipped with a rubber septum and a gas inlet, 0.92 g of a 60% (w/w) dispersion of sodium hydride in mineral oil (0.55 g NaH, 23 mmol) was washed with hexane (3×15 mL) under N 2 . A solution of 5.78 g (11.5 mmol) of N-benzylbis(3-benzenesulfonamidopropyl)amine in 220 mL of DMF was added slowly with stirring. The resulting clear solution was stirred under N 2 while a solution of 1.44 g (11.5 mmol) of 3-chloro-2-chloromethyl-1-propene in 8 mL of DMF was added dropwise over 10 h. Stirring at room temperature under N 2 was continued for an additional 24 h. The solvent was removed by rotary evaporation evaporation using a hot water bath. A solution of the residue in 50 mL of CHCL 3 was washed with water (3×30 mL) and saturated aq. NaCl (2×30 mL) then dried (MgSO 4 ). Removal of the drying agent by filtration and concentration of the filtrate by rotary evaporation gave the crude product as a thick yellow oil. The oil was dissolved in 100 mL of 1:1 (v/v) ethyl acetate/hexane and filtered through a pad of 16 g of basic alumina (Act 1, 80-200 mesh) washing with an additional 50 mL of 1:1 ethyl acetate/hexane. Concentration of the combined filtrates under vacuum afforded 4.93 g (77 O) of 9-benzyl-3-methylene-1,5-dibenzenesulfonyl-1,5,9-triazacyclododecane as a bubbly film that was converted to the hydrochloride salt. [0087] HCL Salt. [0088] A solution of the crude product in 30 mL of CHCl 3 was stirred for 30 m with 10 mL of 2 N aq. HCl and 10 mL of a saturated aq. NaCl solution. The organic layer was separated, washed with 20 mL of saturated aq. NaCl and concentrated by rotary evaporation. The residue was recrystallized by bringing an ethanol solution to a boil and adding ethyl acetate slowly until cloudiness occurs. After cooling to room temperature, the mixture was cooled to −25° C. for a period of 8 h giving a white solid that was isolated by vacuum filtration and recrystallized in a similar manner from acetone/ethyl acetate yielding 3.03 g (45k) of pure compound 211 (hplc), mp 135-136° C. A sample submitted for elemental analysis was dried for 24 h at 78° C. (0.3 mm). 1 H NMR (DMSO-d 6 ) δ 11.6 (br, 1 H, BnNE), 7.79 (d, J=7.8 Hz, 4 H, SO 2 ArH 2,6 ), 7.68 (m, 8 H, SO 2 ArH 3,4,5 BnH 3,5 ), 7.43 (m, 3 H, BnH2,4,6), 5.37 (s, 2 H, C═CH 2 ), 4.30 (d, 2 H, PhCH 2 N), 3.69 (s, 4 H, allylic), 3.09 (m, 8 H, SO 2 NCH 2 CH 2 CH 2 NBn), 1.95 (m, 4 H, NCH 2 CH 2 CH 2 N). 13 C NMR (CDCl 3 ) δ 141.5, 136.9, 133.4, 131.1, 130.4, 129.7, 129.4, 128.8, 127.3, 118.8, 57.1, 51.8, 48.2, 46.3, 20.2. IR (KBr, cm − ) 3060 (w), 2928 (w), 2873 (w), 2445 (br), 1447 (s), 1335 (s), 1163 (s), 1090 (m), 931 (m), 737 (s), 696 (m). UV (CH 3 OH): λ max (logε), 224 (4.2). FABMS: m/z 554 (M+H + , 100). Anal. calc. for C 29 H 35 N 3 S 2 O 4 HCl: C, 59.02; H, 6.15; N, 7.12; S, 10.86; Cl, 6.01. Found: C, 59.39; H, 6.28; N, 7.21; S, 11.34% I.C. Synthesis of Compounds 214, 003 and 004 [0089] The synthesis of: [0090] 214 N-Benzyl-N- [3- (N′-2-methyl-2-propenyl-toluenesulfonamido)propyl]-N-(3-toluenesulfonamidopropyl)amine dihydrogen sulfate [0091] 003 N-Benzylbis[3-(N′-2-methyl-2-propenyltoluenesulfonamido)propyl]amine dihydrogen sulfate [0092] 004 N-Benzylbis[3-N′-2-propenyltoluenesulfonamido)propyl]amine dihydrogen sulfate is shown below: [0093] a. N-Benzylbis [3-N′-2-propenyltoluenesulfonamido) propyl]amine Dihydrogen Sulfate (Compound 004). [0094] In a 250 mL three-necked round bottom flask equipped with rubber septum, a thermometer, a condenser and a nitrogen inlet, a solution of 432 mg (0.79 mmol) of N-benzylbis(3-toluenesulfonamidopropyl)amine (compound 2) in 25 mL anhydrous DMF was added to 125 mg of 60% (w/w) of sodium hydride in mineral oil (75 mg NaH, 1.88 mmol) that was previously washed with hexane (3×15 mL). The mixture was stirred for an hour at room temperature while a solution of 0.30 mL (3.68 mmol) of 3-chloropropene in 4.0 mL of anhydrous DMF was added dropwise. Upon completion of addition, stirring at room temperature under N 2 was continued for an additional 19 h. Vacuum filtration of the reaction mixture and concentration of the filtrate in vacuo gave 0.5 g (100%) of the crude product as a yellow oil. Free base: Preparative TLC of 202 mg of the crude product using 40% EtOAc in hexane on silica gel GF plates (1000 μm) yeilded 166 mg (82%) of the free base as a viscous, colorless oil. 1 H-NMR (CDCl 3 ) δ 7.66 (d, J=8.1 Hz, 4H, TsH 2,6 ), 7.27 (d, 4H, TsH 3,5 ), 7.24 (m, 5H, PhH), 5.61 (ddt, 2H, HC═CH 2 ), 5.11 (ddd, 4H, CH 2 C═CHCH 2 ), 3.76 (d, J=6.3 Hz, 2H, NCH 2 CH═CH 2 ), 3.44 (s, 2H, PhCH 2 ), 3.09 (dd, 4H, TsNCH 2 CH), 2.40 (s, 6H, NSO 2 PhCH 3 ), 2.35 (t, J=6.9 Hz, 4H, BnNCH 2 ), 1.66 (quintet, J=7.2 Hz, 4H, NCH 2 CH 2 CH 2 ). 13 C-NMR (CDCl 3 ) δ 142.95, 139.36, 136.94, 133.27, 129.52, 128.65, 128.01, 127.00, 126.72, 118.43, 58.3, 51.03, 50.70, 45.82, 25.98, 21.34. FT-IR (NaCl plate, cm −1 ): 3064, 3027, 2924, 2802, 1920, 1643, 1598, 1494, 1453, 1418, 1337, 1159, 1091, 1020, 928, 815, 736, 700, 660. [0095] Compound 004: [0096] The purified free base (84 mg, 0.138 mmol) was dissolved in ether and stirred vigorously at 0° C. as a cold solution of 0.43 M H 2 SO 4 in ether (0.32 mL) was carefully added dropwise. The white solid that precipitated was isolated by vacuum-filtration, washed with cold ether and dried in vacuo to give 94 mg (96%) of [0097] Compound 004. [0098] [0098] 1 H-NMR (CDCl 3 ) δ 7.66 (d, J=8.1 Hz, 4H, TsH 2,6 ), 7.27-7.42, (m, 5H, PhH), 7.30 (d, 8.1Hz, 4H, TsH 3,5 ), 5.50 (ddd, 2H, HC═CH 2 ), 5.19 (dd, J=16.8 Hz, 2H, trans-HC═CH 2 ), 5.16 (dd, J=9.9 Hz, 2H, cis HC═CH 2 ), 4.32 (s, 2H, PhCH 2 ) 3.72 (d, J=6.6 Hz, 4H, NCH 2 CH═CH 2 ), 3.13 (m, 8H, BnCH 2 CH 2 ), 2.41 (s, 4H, TsNCH 2 CH 2 ), 2.16 (s, 4H, NCH 2 CH 2 CH 2 ). UV(MeOH):s( λ max) 24,000 (232). FABMS: m/z 610 (MH + , 100). [0099] b. N-Benzylbis[3-N-2-methyl-2-propenyltoluenesulfonamido)propyl]amine dihydrogen sulfate (Compound 003) and N-Benzyl-N-[3-(N′-2-methyl-2-propenyltoluenesulfonamido)propyl]-N-(3-toluenesulfonamidopropyl)]amine Dihydrogen Sulfate (Compound 214) [0100] A solution prepared from 50 mL of anhydrous DMF, 1.14 g (2.15 mmol) of N-benzylbis(3-toluenesulfonamidopropyl)amine and 92 mg of 60% (w/w) sodium hydride in mineral oil (55 mg NaH, 2.30 mmol), which was previously washed with hexane (2×10 mL), was added over 2 h to a cold (0° C.) solution of 290 mg (3.23 mmol) of 3-chloro-2-methylpropene in 20 mL anhydrous DMF. The reaction mixture was stirred at room temperature under N 2 for 22 h, then vacuum-filtered. The filtrate was concentrated in vacuo to give 1.49 of product mixture which was dissolved in CH 2 Cl 2 and separated by flash column chromatography using 230-400 mesh silica gel (Merck) and 45-50% EtOAc in hexane. The collected fractions were analyzed by TLC using 50% EtOAc in hexane. Compound 003 free base eluted first and was obtained as a colorless oil, 234 mg (19%). 1 H-NMR (CDCl 3 ) δ 7.65 (d, J=8.1 Hz, 4H, TsH 2,6 ), 7.26 (d, J=7.8 Hz, 4H, TsH 3,5 ), 7.22 (m, 5H, PhH), 4.84 (d, J=5.1 Hz, 4H, CH 2 =CHCH 2 ), 3.63 (s, 4H, NCH 2 CH═CH 2 ), 3.38 (s, 2H, PhCH 2 ), 3.04 (dd, J=7.8 Hz, 4H, TsNCH 2 CH 2 ) 2.40 (s, 6H, NSO 2 PhCH 3 ), 2.26 (t, J=6.6 Hz, 4H, BnNCH 2 ), 1.70 (s, 3H, CH 3 —CH═CH 2 ), 1.60 (quintet, J=7.8 Hz, 4H, NCH 2 CH 2 CH 2 ). 13 C-NMR (CDCl 3 ) δ 142.97, 140.94, 139.98, 136.98, 129.54, 128.70, 128.07, 127.10, 126.78, 114.22, 58.14, 54.77, 51.14, 46.50, 25.79, 2140, 19.75. FT-IR (NaCl plate, cm −1 ): 3028, 2944, 1813, 1658, 1598, 1494, 1454, 1336, 1160, 1005, 918, 817, 699, 655. Anal. calc. for C 33 H 47 N 3 O 4 S 2 : C, 65.90; H, 7.43; N, 6.59; S, 10.05%. Found: C, 65.81; H, 7.31; N, 6.59; S, 10.14%. Compound 214 free base eluted next and was obtained as a colorless oil, 422 mg (35%). 1 H-NMR (CDCl 3 ) δ 7.67 (d, J=8.3 Hz, 4H, TsH 2,6 ), 7.25 (m, 9H, PhH, TsH), 6.10 (br s, 1 H, TsNH), 4.87 (s, 2H, CH 2 ═CMeCH 2 ), 3.64 (s, 4H, NCH 2 CH═CH 2 ), 3.42 (s, 2H, PhCH 2 ), 3.06 (dd, 2H, TsRNCH 2 CH 2 ), 2.94 (br dd, 2H, NHTsCH 2 ), 2.42 (s, 6H, NSO 2 PhCH 3 ), 2.39 (t, 2H, BnNCH 2 CH 2 CH 2 NRTs), 2.33 (t, 2H, (BnNCH 2 CH 2 CH 2 NHTs), 1.69 (s, 3H, CH 3 —CH═CH 2 ), 1.69 (quintet, 2H, TsRNCH 2 CH 2 CH 2 ), 1.58 (quintet, 2H, TsHNCH 2 CH 2 CH 2 ). 13 C-NMR (CDCl 3 ) δ 143.15, 141.00, 138.61, 129.66, 129.56, 128.98, 128.43, 127.22, 127.07, 114.47, 58.68, 54.96, 52.55, 51.25, 46.61, 42.79, 25.76, 21.44, 19.18. [0101] Compound 214: [0102] A solution of the purified free base (366 mg, 0.627 mmol) in 40 mL of ether was stirred vigorously at 0° C. as a cold solution of 0.18 M H 2 SO 4 in ether (2.0 mL) was carefully added dropwise. The white solid that precipitated was isolated by vacuum-filtration, washed with cold ether and dried in vacuo to give 410 mg (96%) of Compound 214. 1 H-NMR (CDCl 3 δ 7.76 (d, J=8.4 Hz, 2H, TsH 2,6 ), 7.65 (d, J=8.4 Hz, 2H, TsH 2 , ), 7.39-7.48 (m, 5H, PhH), 7.28(d, J=8.3 Hz, 2H, TsH 3,5 ), 7.24 (d, J=7.8 Hz, 2H, TsH 3,5 ), 6.49 (br s, 2H, TsNH, HSO 4 ), 4.80 (dd, 2H, CH 2 ═CMeCH 2 ), 4.28 (dd, 2H, TsRNCH 2 CH 2 ), 3.52 (dd, 2H, PhCH 2 ), 3.21 (br dd, 2H, TsHNCH 2 CH 2 ), 3.01 (br dt, 6H, NCH 2 CH═CH 2 ), 2.39 (t, 3H, NSO 2 PhCH 3 ), 2.34 (s, 3H, NSO 2 PhCH 3 ), 2.08 (quintet, 4H, NCH 2 CH 2 CH 2 N), 1.54 (s, 3H, CH 3 —CH═CH 2 ). 13 C-NMR (CDCl 3 ) δ 143.57, 142.97, 140.06, 137.12, 135.79, 131.42, 130.03, 129.81, 129.68, 129.39, 128.11, 127.332, 127.15, 115.56, 57.042, 55.55, 51.122, 49.96, 45.80, 40.16, 24.08, 23.24, 21.41, 21.38, 19.79. UV(MeOH):s( λ max) 24,000 (232). [0103] c. Compound 003: [0104] A solution of the purified free base (210 mg, 0.329 mmol) in 15 mL of ether was stirred vigorously at 0° C. as a cold solution 0.43 M H 2 SO 4 in ether (0.76 mL) was carefully added dropwise. The white solid that precipitated was isolated by vacuum-filtration, washed with cold ether and dried in vacuo to give 238 mg (98k) of Compound 003. 1 H-NMR (CDCL 3 ) δ 7.68 (d, J=7.8 Hz, 4H, TsH 2,6 ), 7.53 (br d, J=4.2 Hz, 2H, PhH), 7.43 (d, J=3.3 Hz, 3H, PhH), 7.30 (d, J=7.8 Hz, 4H, TsH 3,5 ), 4.86 (d, J=4.2 Hz, 4H), 4.28 (s, 2H, PhCH 2 ), 3.58 (s, 4H, NCH 2 CH═CH 2 ), 3.09 (m, 8H, TsNCH 2 CH 2 ), 2.40 (s, 6H, NSO 2 PhCH 3 ), 2.13 (quintet, 4H, NCH 2 CH 2 CH 2 ), 1.61 (s, 3H, CH 3 —CH═CH 2 ). 13 C-NMR (CDCl 3 ) δ 142.97, 140.94, 139.98, 136.98, 129.54, 128.70, 128.07, 127.10, 126.78, 114.22, 58.14, 54.77, 51.14, 46.50, 25.79, 21.40, 19.75. UV(MeOH):s( λ max) 23,000 (232), Anal. calc. for C 35 H 47 N 3 O 4 S 2 .H 2 SO 4 : C, 57.12; H, 6.71; N, 5.71; S, 13.07%. Found: C, 57.97; H, 6.90; N, 5.77; S, 12.45%. FABMS: m/z 638 (MH + , 100). II. Synthesis of Compounds 12, 13, 14, 15, 16, 17 [0105] The synthesis of [0106] 12 3-Methylene-1,5-ditosyl-1,5,9-triazacyclododecane, [0107] 13 5,9-Ditosyl-7-hydroxymethyl-1,5,9-triazabicyclo-[5,5,0]tridecane, [0108] 14 5,9-Ditosyl-13-oxa-1,5,9-triazatricyclo[5,5,1 1,7 , 1 7,12 ] -tetradecane, [0109] 15 9-Benzyl-3-hydroxymethyl-1,5-ditosyl-1,5,9-triazacyclododecane, [0110] 16 9-Benzyl-3-chloromethyl-1,5-ditosyl-1,5,9-triazacyclododecane, and [0111] 17 3-Chloromethyl-1,5-ditosyl-1,5,9-triazacyclododecane is shown in Scheme 2. [0112] a. The benzyl group of Compound 1 (CADA) was removed by reaction with alpha-chloroethyl chloroformate (ACE-Cl) giving the secondary amine (compound 12). [0113] b. Intramolecular aminomercuration of 12 by reaction with mercuric acetate followed by alkaline reduction gave bicyclic alcohol 13 (53%) after separation of the product mixture by chromatography. [0114] c. Oxidation of 12 with m-chloroperoxybenzoic acid gave isoxazolidine 14 (20%), apparently via the nitrone produced by oxidation at nitrogen prior to epoxidation of the exocyclic double bond. [0115] d. Functionalization of the alkene moiety was carried out via hydroboration of 1 with thexylborane, yielding alcohol 15 after alkaline hydrogen peroxide workup. [0116] e. Chloro analogue 16 was then prepared by reaction of 15 with triphenylphosphine and CCl 4 , and debenzylation to 17 was performed by reaction of 16 with formic acid and 5% palladium-on-carbon. III. Synthesis of Compounds 18, 19, 21, 22, 23, 24, and 26 [0117] The synthesis of [0118] 18 N,N-bis(3-toluenesulfonamidopropyl)toluenesulfonamide, [0119] 19 1,5,9-Tritosyl-1,5,9-triazacyclododecane, [0120] 21 11-Methylene-1,5,9-triazabicyclo[7,3,3]pentadecane, [0121] 22 3-Methylene-1,5,9-tritosyl-1,5,9-triazacyclododecane, [0122] 23 3-Hydroxymethyl-1,5,9-tritosyl-1,5,9-triazacyclododecane, [0123] 24 3-Chloromethyl-1,5,9-tritosyl-1,5,9-triazacyclododecane, [0124] 26 1,5,9-Triazabicyclo[9,1,1]tridecane is shown in Scheme 3. [0125] a. The tritosylamide amide (compound 18) is prepared by tosylation of N,N-bis(3-aminopropyl)amine (commercially available) [0126] b. Cyclization of the disodium salt of 18 with propylene glycol ditosylate gave macrocycle 19 (50%). [0127] C. Macrocycle 19 was detosylated to 1,5,9-triazacyclododecane 20 (60%) by treatment with 98% sulfuric acid at 100° C. [0128] d. Macrocyclic triamine 20 is commercially available, but is readily prepared in multiple-gram quantities and the yield of 19 has been improved to 70%. [0129] e. Reaction of 20 with 3-iodo-2-iodomethyl-1-propene gave bicyclic analogue 21 in 60-70% yield. [0130] f. Alkene 22(59%) was prepared by Richman-Atkins cyclization of 18 with 3-chloro-2-chloromethyl-l-propene. [0131] g. Another series of analogues was prepared from alkene 22. [0132] By methods described previously for functionalization of compound 2 (Scheme 1), hydroboration/oxidation of 22 gave alcohol 23, which was then converted to chloride 24 in greater than 90% yield overall. The chloromethyl group of 25 survives the harsh conditions required for tosyl cleavage, yielding 25. Transannular cyclization was attempted by treating this compound with potassium carbonate in isopropanol, but a 59% yield of azetidine 26 was obtained along with a minor amount of elimination product (27). [0133] All of the analogues appearing in Schemes 1-3 can be synthesized in multiple-gram quantities by these methods. Most can be purified by recrystallization. Certain amines in these series occur as viscous oils or glasses, but in many cases crystalline HCl salts can be obtained. The HCl salts of 1 and 2 have also been prepared, with the expectation that enhanced water solubility improves the ease of administration of these drugs. IV. Synthesis of Compounds 41, 42, 43, 44, 45 and 46 [0134] Other symmetrical analogues [0135] 41 9-Benzyl-3-keto-1,5-ditosyl-1,5,9-triazacyclododecane [0136] 42 9-Benzyl-3-methyl-1,5-ditosyl-1,5,9-triazacyclododecane [0137] 43 9-Benzyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane-9-oxide [0138] 44 9-Acyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane [0139] 45 9-Alkyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane [0140] 46 9-Acyl-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane epoxide [0141] in the family of triaza compounds to be used in the invention are shown in Scheme 4. [0142] Compounds 41 to 46 are closely related to CADA. They are designed to have enhanced water solubility and to be capable of modification of biomolecules by electrostatic or hydrophobic interaction at the double bond position for reversible binding of proteins, such as HIV capsid proteins, integrase or proviral DNA by S N 2′ attack of an O, N or S at W. [0143] Compounds 41, 42 and 43 are prepared in one step by oxidation or reduction of 1. Ketone 41 is prepared by ozonolysis of 1-HCl in methanol, followed by reductive workup with dimethyl sulfide. The exocyclic double bond is reduced to give 42 by catalytic hydrogenation under conditions known for hydrogenation of disubstituted alkenes in the presence of benzylamine functionality. Compound 41 has improved water solubility and 42 has similar polarity to 1, but neither can undergo the S N 2′ covalent binding mechanism mentioned above. [0144] Ketone 41 is capable of Schiff-base condensation with an amino group (e.g. of a lysine side-chain). Amine N-oxide 43 is prepared by reaction of 1 with hydrogen peroxide in methanol. The water solubility of this compound should be similar to that of 1•HCl so it can be used to test whether the protonation equilibrium (1 1•H + ) is important to the mechanism of action. Compound 12, previously prepared according to Scheme 2, is an important analogue of 1 and an intermediate in the synthesis of 44-46. Acylation to 44 (R═H, alkyl or aryl) replaces the benzyl group with acyl groups of various sizes to test the steric and electronic requirements for this site. If protonation of the nitrogen atom is important, then alkylation of 12 to 45 (R=methyl, ethyl, β-hydroxyethyl, isopropyl, etc.) independently tests the effects of steric bulk and polarity at this site. A series of analogues of type 45 can be prepared in which R is a benzyl group bearing a polar substituent (OH, NO 2 , SO 3 H, CO 2 H, NH 2 or NMe 2 ) to solubilize the drug. Finally, epoxidation of 44 with m-CPBA or Oxone will give 46 with enhanced polarity and reactivity at the exocyclic site toward nucleophilic attack. [0145] Synthesis of compound 43 was as follows: [0146] 9-Benzyl-3-methylene-1,5-ditosyl-1,5,9-triaza-9-N-oxide-cyclododecane (ARB 95-212) (Compound 43). [0147] H 2 O 2 Method. [0148] In a 250 mL round-bottomed flask, 3.00 g (5.2 mmol) of CADA was diluted with 100 mL of ethanol and 30 g of 30% H 2 O 2 . A magnetic stir bar was added, condenser attached and the mixture was heated by means of an oil bath to reflux. After 5 h, the clear solution was allowed to cool and then concentrated by rotary evaporation. The residue was diluted with 50 mL of CHCl 3 and 30 mL of water and stirred briefly to dissolve the contents. The organic layer was separated, washed with water (2×25 mL) then with 25 mL of saturated aq. NaCl and dried (MgSO 4 ). Filtration of the drying agent and concentration of the filtrate afforded a bubbly film. Further purification was performed by gravity column chromatography with neutral alumina. (Act. 1, 60-325 mesh) using CHCl 3 followed by 20:1 (v/v) chloroform:ethanol to elute Compound 43. Concentration of the fractions to a bubbly film followed by trituration with acetone afforded 1.44 g (47%) of Compound 43 as a white solid, mp 129-130° C. [0149] Oxone Method. [0150] A mixture of 2.50 g (4.29 mmol) of CADA, 1.25 g (14.8 mmol) of sodium hydrogen carbonate, 2.71 g (4.4 mmol) of Oxone, 25 mL of water and 75 mL of ethanol was stirred with a magnetic stir bar and heated (oil bath) to 45-50° C. for 24 h. After cooling to room temperature, the solid was removed by suction filtration and washed with 40 mL of ethanol (CADA was recovered by washing the solid with CHCl 3 and concentration of the chloroform filtrate). The combined ethanol filtrates were concentrated and a CHCl 3 solution of the residue was dried over MgSO 4 . Removal of the drying agent by filtration and concentration of the filtrate afforded 1.20 g (46w) of Compound 43 ( 1 H NMR) as a bubbly film. Purification by gravity column chromatography with neutral alumina as described in the previous method afforded 0.35 g of Compound 43 as a white solid after trituration with acetone. A sample submitted for elemental analysis was dried at 40° C. (0.2 mm) for 4 h. TLC (alumina): R f =0.36, 20:1 (v/v) chloroform:ethanol. 1 H NMR (CDCl 3 /TMS) δ 7.65 (m, 2 H, BnArH 3,5 ), 7.62 (d, J=8.1 Hz, 4 H, TsH 2,6 ), 7.40 (m, 3 H, BnArH 2,4,6 ), 7.32 (d, J=8.1 Hz, 4 H, TsH 3,5 ), 5.33 (s, 2 H, C═CH 2 ), 4.29 (s, 2 H, PhCH 2 ), 3.70 (s, 4 H, allylic), 3.45 (t, 4 H, Bn—N(O)—CH 2 ), 3.10 (t, 4 H, Ts-NCH 2 ), 2.45 (s, 6 H, TsCH 3 ), 2.10 (m, 4 H, NCH 2 CH 2 ). 13 C NMR (CDCl 3 ) δ 144.0, 141.7, 133.7, 132.4, 130.0, 129.8, 129.3, 128.3, 127.5, 118.8, 71.9, 61.2, 52.7, 48.8, 22.0, 21.5. IR (KBr, cm −1 ) 3063 (w), 3032 (w), 2951 (w), 2925 (w), 2867 (w), 1598 (w), 1458 (m), 1339 (s), 1162 (s), 1090 (m), 1034 (w). UV (CH 3 OH): λ max (loge), 230 (4,4). FABMS: m/z 598 (M+H + , 41). Anal. calc. for C 31 H 39 N 3 S 2 O5: C,62.29; H, 6.58; N, 7.03; S, 10.73. Found: C, 61.92; H, 6,53; N, 7.24; S, 10.97%. IX Synthesis of Compound 211 [0151] An analogue of compound 44 is compound 213 9-(Ethyloxycarbonyl)-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane. [0152] Compound 213 was prepared as follows: [0153] 9-(Ethyloxycarbonyl)-3-methylene-1,5-ditosyl-1,5,9-triazacyclododecane (compound 213). In an oven dried 250 mL round-bottoned flask, 8.20 g (14.1 mmol) of CADA was diluted with 65 mL of freshly distilled (P 2 O 5 )1,2-dichloroethane. A magnetic stir bar, reflux condenser with a gas inlet and oil bath were added then the system purged with nitrogen. Ethyl chloroformate (1.70 mL; 17.8 mmol) was added by syringe and the solution heated at reflux for 5 h. The solvent was removed using a rotary evaporator with a 40° C. water bath. Dilution of the oily residue with 60 mL of a solution of 2:3 (v/v) ethyl acetate:hexane caused a white precipitate to form at room temperature after scratching the glass. The solid was filtered and washed with 3×30 mL of a solution of 2:3 (v/v) ethyl acetate:hexane giving 6.63 g (83%) of Compound 213, mp 125-126° C. (after drying at 78° C. and 0.9 mm for 19 h). TLC (silica): R f =0.24, 1:1 (v/v) ethyl acetate:hexane. 1 H NMR (CDCl 3 /TMS) δ 7.68 (d, J=8.3 Hz, 4 H, SO 2 ArH 2,6 ), 7.33 (d,J=8.3 Hz, 4 H, SO 2 ArH 3,5 ), 5.21 (s,2 H, C=) 4.07 (quart., J=7 Hz, 2 H, CO 2 CH 2 CH 3 ), 3.85 (s, 4 H, allylic), 3.33 (t, J=6.4 Hz, 4 H, EtO 2 CNCH 2 ), 3.11 (m, 4 H, SO 2 NCH 2 ), 2.44 (s, 6 H, PhCH 3 ), 1.85 (m, 4 H, NCH 2 CH 2 CH 2 N), 1.21 (t, J=7 Hz, 3 H, CO 2 CH 2 CH 3 ). 13 C NMR (CDCl 3 ) δ 157.0, 143.6, 139.4, 135.7, 129.8, 127.2, 116.9, 61.2, 51.4, 45.5, 45.2, 28.0, 21.4, 14.7 IR (KBr, cm −1 ) 2990 (w), 2990 (w), 2948 (w), 1688 (s), 1598 (w), 1485 (m), 1424 (m), 1343 (s), 1230 (s), 1154 (s), 1093 (s), 1027 (m), 903 (m), 818 (m), 788 (m). FABMS: m/z 564 (M+H+, 100). Anal. calc. for C 27 H 37 N 3 S 2 0 6 : C, 57.53; H, 6.62; N, 7.45; S, 11.37. Found: C, 57.36; H, 6.54; N, 7.73; S, 11.74%. V. Synthesis of Compounds 50, 51, 52 and 53 [0154] Another series of compounds is illustrated by formula II. These compounds include [0155] 50 9-Benzyl-1-formyl-3-methylene-1,5,9-triazacyclododecane [0156] 51 9-Benzyl-l-formyl-3-methylene-5-tosyl-1,5,9-triazacyclododecane [0157] 52 9-Benzyl-3-methylene-1-tosyl-1,5,9-triazacyclododecane [0158] 53 e.g. 9-Benzyl-3-methylene-1-acyl-5-tosyl-1,5,9-triazacyclododecane [0159] These compounds have three different substituents (X, Y and Z) on the three nitrogen atoms of a 12-membered ring. The synthetic plan utilizes a series of reactions reported for selective, unsymmetrical substitution of 1,5,9-triazacyclododecane. The intermediate is 3-methylene-1,5,9-triazacyclododecane (27), which can be obtained quantitatively by elimination of HCl from 25 Scheme 3. Reaction of 27 with neat DMF dimethyl acetal gives 47 in high yield as shown in Scheme 5. Monoalkylation with benzyl bromide will give 48 or 49 (or both). Both of these salts are synthetically useful, but the completion of the synthesis is illustrated with 48. [0160] Alkaline hydrolysis will yield formamide 50, which is an unsymmetrical example of formula 29, where X=H, Y=CHO and Z=benzyl. Tosylation of 50 and alkaline hydrolysis will give 51 and 52 respectively. Compound 52 is a mono-detosylated analogue of 1 and the missing tosyl group can be replaced with almost any alkyl, acyl, alkanesulfonyl or arenesulfonyl group of interest (53, Y=various ). For example, Y=benzyl shows the effect of two protonation sites, while Y=p-bromobenzensulfonate shows the effect of enhancing the sulfonamide leaving group ability. Candidates for improved water solubility include compounds of type 29 in which Z=benzyl and X and Y are benzenesulfonyl groups bearing polar substituents, such as NH 2 , OH or CO 2 H. VI. Synthesis of Macrocyclic Triamines of varying Ring Size: Compounds 55 and 60 [0161] Varied ring size and incorporation of amide functionality into the lare ring in macrocylic lactams are shown in Scheme 6. [0162] Almost any linear triamine of type 54 (m, n=2-6, R=alkyl, aryl or, acyl) is available by methods used for the synthesis of linear and macrocyclic polyamines. Cyclization of these triamines with methyl acrylate or chloroacetyl chloride gives the corresponding macrocycles (55; a=2 or 1, respectively). [0163] The acrylate cyclization is precedented by formation of the phenyl-substituted analogue of 55 (a=2, m=1, n=1, R=H) by reaction of the triamine with methyl cinnamate. Chloroacetyl chloride has been used in the syntheses of numerous polyazamacrocycles by the so-called crablike cyclization, which is usually carried out in refluxing acetonitrile without resort to high-dilution conditions. The low reactivity of the amide nitrogen atom of 55 enables selective functionialization of the third nitrogen, affording 56 (Y=alkyl, acyl, alkanesulfonyl or arenesulfonyl). Both series of macrocyclic lactams (55 and 56) can then be reduced to macrocyclic triamines under various conditions for the reduction of amides to amines. The resulting compounds are saturated analogues of type 29 bearing three different X, Y and Z groups, any of which could bear water-solubilizing substituents, and having ring sizes in the range of 9-18 carbon and nitrogen atoms. VII. Synthesis of Open-Chain or Non-Macrocyclic Analogues 58, 59, 60, 61, 61, 63 and 64 [0164] Open-chain and non-macrocyclic analogues are shown in Scheme 7. [0165] These analogues are synthesized from a series of 1,n-alkanediamines via the N-tosylphthalimide derivatives (57, n=2-7). Alkylation of the sodium, potassium or cesium salt of 57 with either 2-chloromethyl-3-chloro-1-propene or 2-iodomethyl-3-iodo-l-propene will give chain-extended intermediate 58 or 59. It is possible to control the product selectivity of the reaction by varying stoichiometry and order of addition of the reactants. Intermediates of type 5a bear a second leaving group (X), which will be displaced by various amine or sulfonamide nucleophiles, yielding 60 (Y=R′,SO 2 R′ or SO 2 Ar). Cleavage of the phthalimide protecting group by hydrazine will give primary amine 61, which can be acylated or sulfonated to analogue series 62. The same Gabriel synthesis approach can be applied to 59 (n=2-8); an unsymmetrical series of compounds, differing only chain length relative to 59, can be prepared by reaction of 58 with 57. The resulting series of compounds includes symmetrical and unsymmetrical open-chain analogues of 1 containing the allylic tosylamide functionality and a total of 3-4 nitrogen atoms. VIII. Synthesis of Bicyclic Compounds 66, 67 and 68 [0166] An additional series of analogues consists of the bicyclic compounds 34-36 shown below: [0167] Examples of these bicyclic compounds and their syntheses are shown in Scheme 8. [0168] In bridged pyridine compound 66, corresponding to 34, the tertiary amino basic site is replaced by a pyridine nitrogen atom and the aromatic benzyl group is replaced by the aromatic pyridine ring. The Richman-Atkins synthetic approach shown has been used successfully in the preparation of many bridged pyridine host compounds. By analogy with known cyclizations of 65 (n=1), reaction with 2-chloromethyl-3-chloropropene or 2-iodomethyl-3-iodopropene under high-dilution conditions gives analogue 66 (n=1). The entire series in which n=1-6 is preparable by this method. In 35 and 36 the second ring is fused to two carbon atoms of CADA, leaving the center nitrogen atom free for substituent Z. Two benzene fused examples of 35 and 36 are 67 and 68, which are shown in Scheme 8 with their syntheses. The five steps shown in each case parallel the 5-step synthesis of CADA (Scheme 1) and yields should be comparable. The fused benzene ring mimics the benzyl group of CADA, leaving substituent Z variable. In all three cases (66-68) the fused aromatic ring can bear polar substituents enhancing water solubility. [0169] Other analogs such as those functionalized with polar groups for increased solubility can be synthesized using the synthesis methods described above, coupled with various steps known in the art and described, e.g., by T. J. Richman et al., Macrocyclic Polyamines: 1,4,7,10,13,16 - Hexaazacyclooctadecane in Organic Synthesis. Coll. Vol. VI , Noland, W. E., Ed., Wiley, New York, 1988, pp. 652-662; Bradshaw et al. Aza-Crown Macrocycles , Wiley, New York, 1993, chpt. IV. [0170] Such polar groups include, for example, NO, NO 2 , NH 2 , OH, SH, OR, SR, COR, SO 2 R, SOR, halide (F, Cl, Br, I), NHR, NR 2 , HCO, COOH, COOR, C≡N, alkyl halide, etc. (R=alkyl of 1-10 carbons). [0171] Antiviral activity was tested as follows: EXAMPLE 1 [0172] In these tests, the IC 50 (50% inhibitory concentration) is the concentration resulting in 50% cellular toxicity. EC 50 (median effective concentration) is the compound concentration that reduces infection by 50%. The effectiveness of a compound against a virus is expressed as TI 50 (median therapeutic index) which is determined by the ratio IC 50 /EC 50 . [0173] Compounds of the invention were tested to assess the efficacy of the inhibitory effect of the compounds against HIV. The screen was carried out in a soluble formazan assay by the tetrazolium method according to Weislow et al., J. Natl. Cancer Inst. 81:577-586, 1989. [0174] The compound was dissolved in dimethyl sulfoxide (DMSO) (final conc. less than 0.25%) and then diluted 1:100 in cell culture medium. Because DMSO is toxic to cells at concentration above 1%, the concentration of the compound in DMSO should be at least 10 μM before dilution with aqueous solution. Various concentrations of the compound were tested against HIV-1 in CEM-IW cells. After six days incubation at 37° C. in a 5% carbon dioxide atmosphere, viable cells were analyzed through addition of tetrazolium salt XTT followed by incubation to allow formazan color development. Cell viability was viewed microscopically and detected spectrophotometrically to quantitate formazan production. [0175] In a test against HIV-1(6S)-AZT sensitive, the compound CADA (compound 1) was found active. The IC 50 index was greater than 5.00×10 −5 M; the EC 50 was 1.20×10 −6 M; and the TI 50 (IC/EC) was greater than 2.6×10 +1 . [0176] In a second test, the compound from another batch of CADA was confirmed active in a primary screen. The IC 50 index was greater than 6.00×10 −6 M; the EC 50 was 2.40×10 −6 M; and the TI 50 was greater than 2.50×100. EXAMPLE 2 [0177] Testing was carried out as described in Example 1 against additional HIV strains. The compound CADA was active against the following viruses using the indicated cell lines: [0178] IIIB strain of HIV-1/MT-4 cell line [0179] HIV-2/CEM cell line [0180] SIV/MT-4 cell line [0181] AZT—resistant HIV-1/MT-2 and MT-4 cell lines [0182] AZT—sensitive HIV-1/MT-4 cell line [0183] A17, a strain of HIV-1 resistant to most of the non-nucleoside reverse transcriptase inhibitors/MT-2 and MT-4 cell lines, [0184] Wejo, a clinical isolate of HIV-1/PBMCs (fresh human peripheral blood mononuclear cells). [0185] The compound was found to be active against these viruses with an EC 50 of 2 μM, a IC 50 greater than 3 μm and a TI 50 greater than 15. This means that good activity and low cell toxicity were observed in the micromolar range of concentration of the compound. EXAMPLE 3 [0186] Studies were carried out to determine the mechanism of action of the compounds in the HIV life cycle. At least 16 steps in the HIV life cycle have been identified as possible points for therapeutic intervention, yet all the anti-HIV drugs licensed in the U.S. so far (AZT, ddI and ddC) are nucleoside inhibitors of HIV reverse transcriptase (RT). Another group of antivirals, the bicyclams, are believed to act at an early stage in the retrovirus replicative cycle, apparently inhibiting viral uncoating. The action of other anti-HIVs such as the quinolines is unknown. [0187] The studies were based on activity of the compound against HIV-1 in peripheral blood lymphocytes. The results with different solutions and different batches of the compound confirm that the compound is active at submicromolar levels (EC 50 ) and has low cytotoxicity (IC 50 ). The results of the studies on the mechanism of reaction are summarized in the Table below: TABLE 1 Batch 1 A B Batch 2 PBL/HIV-1 Wejo Infection EC 50 (μM) 0.55 0.16 0.65 IC 50 (μM) >100 >100 >100 Attachment p 24 based No Inhibition RT activity (rA.dT) ID 50 (μM) No Inhibition Time of Action Time Course LTR/gag No Inhibition of proviral DNA synthesis Protease Activity ID 50 (μM) 40 (rp HPLC) Mo-MO/HIV-1 Ba-L Infection EC 50 (μM) 1.5 (fresh) IC 50 (μM) over 30 (high test) Latent Infection (Ul/TNF) No inhibition [0188] Preliminary mechanism of action studies showed that the compound CADA does not appear to inhibit HIV reverse transcriptase or HIV protease at the concentrations determined to be effective in the in vitro assays. It is believed that the CADA acts prior to the integration of virus into the cellular genome, but it does not appear to inhibit virus attachment or cell fusion. [0189] It was concluded that the mechanism of action of the new compounds is different than those of either of the two classes of AIDS drugs currently in use or in clinical trials (reverse transcriptase and protease inhibitors). EXAMPLE 4 [0190] Additional studies on stability, solubility, formulation and pharmokinetics were carried out. Plasma elimination and urinary recovery from mice following i.v. administeration were examined. Solubility of the compound in human, mouse, rat plasma and plasma ultrafiltrate were examined. Stability of the compound in human urine was determined. [0191] The conclusions of these studies are as follows: [0192] 1. The compound is stable in mouse and rat plasma (t ½ greater than 200 hrs) and is stable in pH 4.0 buffer (t ½ 139 hrs) and in human plasma (t ½ 126 hrs). [0193] 2. The compound is soluble in human plasma at 37° C. (1-2 ug/mL =2-3 uM). [0194] 3. The compound can be formulated for animal studies at a concentration of 1.2 uM in a 1:20 mixture of DMSO and normal saline (pH 2.7). [0195] 4. The compound is detectable in mouse plasma up to 2 hours after in vivo intravenous administration. EXAMPLE 5 [0196] Additional antiviral testing was carried out to assess the efficacy of the compounds of the invention against human cytomegalovirus (HCMV), herpes simplex virus (HSV), rous sarcoma virus (RSC) and influenza virus (FLU WSN). [0197] Compounds tested were the HCl salts of the products compounds (1), (2) and (12) and non-salt compound (1). The results are summarized in the table below TABLE 2 IC 50, ug/mL Virus 2.HCl CADA(1) 1.HCl 12.HCl HCMV 5 >30, >50 PDR 3 HSV 11   10, 30 PDR 1.5 RSV 4 >30, >50 PDR 4 PDR FLU WSN >50 >30, >50 >50 12 [0198] While not wishing to be bound by any one theory, one hypothesis is that in the mechanism of action of the invention, the drug inhibits retroviral uncoating by binding to a hydrophobic pocket on one of the HIV capsid proteins. A series of hydrophobic compounds, such as disoxaril or Win 51711 are known to inhibit picornavirus replication by this mechanism and various other drugs seem to neutralize rhinoviruses by binding to a specific hydrophobic pocket within the virion capsid protein. The major HIV capsid protein (p24) is a potential target, although it has not been shown that such compounds can be as effective against an enveloped virus as they are against simple icosahedral viruses. Anti-influenza A drugs amantadine and rhimantidine inhibit virus replication by blocking a proton channel associated with capsid protein M2, thereby interfering with virus uncoating. [0199] The bicyclams are the only reported inhibitors of HIV uncoating. CADA superficially resembles bicyclam as a macrocyclic polyamine. CADA's basic tertiary amino group should be protonated at physiologic pH and both compounds could function as metal chelating agents. These similarities with bicyclams are only superficial, however, because the toluenesulfonamide groups of 1 should render it a very weak metal chelator and 1 is much more lipophilic (hydrophobic) than bicyclams which should be polyprotonated a physiologic pH. Although a sulfonamide, CADA is cationic rather than anionic and does not belong to the polyanionic sulfate class of anti-HIV agents that inhibit binding of the virion to target cells. [0200] Inhibition of the HIV enzyme integrase is a second hypothetical mechanism of action consistent with the observation that CADA acts at an early stage of HIV replication. Integrase controls the incorporation of virally transcribed DNA into the host genome, a key step in HIV replication. Many drugs have been found to bind and inhibit HIV-1 integrase in enzymatic in vitro experiments, but none of these compounds prevents HIV replication in intact cells. It is possible that CADA is the first therapeutically active drug operating by integrase inhibition. [0201] Whether CADA is an uncoating inhibitor, an integrase inhibitor or operates by another mechanism, its discovery leads to a new class of drugs complementing inhibitors of reverse transcriptase and protease, used individually or in combination therapy. CADA has a unique activity profile and it operates at an early stage of HIV replication by a mechanism not involving adhesion, fusion or reverse transcriptase inhibition. The discovery shows the potential for a new approach to AIDS chemotherapy. It is likely that the synthesis of hundreds of analogues will produce potent anti-HIV agents with improved solubility and bioavailability. EXAMPLE 6 [0202] Additional antiviral testing was carried out to test the efficacy of compounds of the invention against human cytomegalovirus (HCMV) and another herpesvirus, Variecella Zoster Virus (VZV). The compounds tested were compound (1), the HCl salt of compound (1), Compounds 211, 43, 213 and 214. [0203] The results are summarized in the table below. TABLE 3 Antiviral Screening Results for Herpesviruses Human Cytomegalovirus 2 Varicella Zoster Virus 3 Compound EC 50 CC 50 SI EC 50 CC 50 SI CADA(1) >34 133 ’13.9 5.3 89 16.8 1.HCl >160 >160 0 3.4 >160 >47.1 211 >170 >170 0 91.7 >170 >1.8  43 >170 >170 0 24.3 >170 >7.0 213 3.0 167 55.6 170 >180 >1.0 214 2.2 >150 >68 25.2 68.5 2.7 (20.5) (147) (7.1) EXAMPLE 7 [0204] Testing was carried out as described in Example 1 against additional HIV strains MB48 and 2h. The results are summarized in the table below. TABLE 4 ED 50 (μM) 1 Compound MB48/MT-2 2 MB48/HeLa 3 2h/PBMC 4 CADA(1) 0.8 0.5 0.15 1 • HCl 0.2 0.1 0.15 211 1.9 1.5 0.5  43 1.8 3.5 0.5 004 2.6 3.5 0.5 [0205] These results show antiviral activity in the submicromolar range. EXAMPLE 8 [0206] The efficacy of intravenously administered CADA•HCl in rabbits during ocular Varicella Zaster Virus (VZV) infection was determined. Intravenous therapy with 5 mg/kg/day CADA•HCl for 11 days was compared with 20 mg/kg/day acyclovir (ACV) intravenous therapy. [0207] Rabbits were bilaterally inoculated with an intrastromal injection of 100 μL of McKrae strain VZV titer of 10 5 /ml. On day 2 to 3 post inoculation (PI) animals were evaluated and divided into equal groups. [0208] Intravenous therapy of CADA•HCl, acyclovir and placebo saline was initiated immediately after animal grouping and continued through day 11 PI. Two groups received CADA•HCL intravenous therapy for 9 days, one group at a “low-dose” of 5 mg/kg/day and another group at a “high-dose” of 10 mg/kg/day. Other groups received similar IV therapy with ACV at 20 mg/kg/day and with placebo. [0209] As a result, VZV-induced corneal stromal and iris disease demonstrated a positive response to therapy with CADA•HCL and with ACV. CADA•HCl at both concentrations was effective in reducing the development of stromal disease. By day 6 PI, acyclovir was intermediate between placebo and low dose CADA•HCl. [0210] Both CADA-HCL and ACV also showed a positive therapeutic response in reducing iris disease development. In efficacy against iris disease (uveitis) CADA•HCl and ACV both showed a positive effect. By day 5 PI, CADA•HCl was more effective than acyclovir therapy in reducing development of iritis and in speeding resolution of VZV disease.

A method of inhibiting viruses in which a virus is contacted with an antiviral amount of a compound of formula I. Activity is shown against HIV and other viruses. wherein W is a bridge carbon which has a polar or non-polar side group; X and Y independently are an aromatic group, an alkyl group, a sulfonyl group or a carbonyl group, said aromatic group is selected from the group consisting of Ar, Ar sulfonyl, Ar carboxy and Ar alkyl, where Ar is an aromatic cyclic or aromatic heterocyclic ring having from five to seven members; said alkyl group having from one to ten carbons; Z is a group listed for X and Y, a fused aryl moiety having from seven to ten carbons or hydrogen; a, d and e independently are a number from zero to 10; c and b independently are a number from one to 10; and the formula is cyclic or acyclic and includes sufficient hydrogens for a stable molecule.

This application is a continuation, of application Ser. No. 08/120,698, now abandoned, filed Sep. 10, 1993, which is a Continuation Application of 07/879,037 now abandoned, filed Apr. 30, 1992, which was a Continuation-In-Part Application of 07/708,267 filed Jun. 24, 1991, now abandoned, which was a Continuation Application of 07/327,214 filed Mar. 22, 1989, now abandoned. BACKGROUND OF THE INVENTION Traditional cancer chemotherapy relies on the ability of drugs to kill tumor cells in cancer patients. Unfortunately, these same drugs frequently kill normal cells as well as the tumor cells. The extent to which a cancer drug kills tumor cells rather than normal cells is an indication of the compound's degree of selectivity for tumor cells. One method of increasing the tumor cell selectivity of cancer drugs is to deliver drugs preferentially to the tumor cells while avoiding normal cell populations. Another term for the selective delivery of chemotherapeutic agents to specific cell populations is "targeting". Drug targeting to tumor cells can be accomplished in several ways. One method relies on the presence of specific receptor molecules found on the surface of tumor cells. Other molecules, referred to as "targeting agents", can recognize and bind to these cell surface receptors. These "targeting agents" include, e.g., antibodies, growth factors, or hormones. "Targeting agents" which recognize and bind to specific cell surface receptors are said to target the cells which possess those receptors. For example, many tumor cells possess a protein on their surfaces called the epidermal growth factor receptor. Several growth factors including epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) recognize and bind to the EGF receptor on tumor cells. EGF and TGF-alpha are therefore "targeting agents" for these tumor cells. "Targeting agents" by themselves do not kill tumor cells. Other molecules including cellular poisons or toxins can be linked to "targeting agents" to create hybrid molecules that possess both tumor cell targeting and cellular toxin domains. These hybrid molecules function as tumor cell selective poisons by virtue of their abilities to target tumor cells and then kill those cells via their toxin component. Some of the most potent cellular poisons used in constructing these hybrid molecules are bacterial toxins that inhibit protein synthesis in mammalian cells. Pseudomonas exotoxin A (PE-A) is one of these bacterial toxins, and has been used to construct hybrid "targeting - toxin" molecules (U.S. Pat. No. 4,545,985). PE-A is a 66 kD bacterial protein which is extremely toxic to mammalian cells. The PE-A molecule contains three functional domains: 1.) The amino-terminal binding domain, responsible for binding to a susceptible cell; 2.) The internally located "translocating" domain, responsible for delivery of the toxin to the cytosol; 3.) The carboxy-terminal enzymatic domain, responsible for cellular intoxication. PE-A has been used in the construction of "targeting-toxin" molecules, anti-cancer agents in which the 66 kD molecule is combined with the tumor-specific "targeting agent" (monoclonal antibody or growth factor). The "targeting-toxin" molecules produced in this manner have enhanced toxicity for cells possessing receptors for the "targeting agent". A problem with this approach is that the PE-A antibody or growth factor hybrid still has a reasonably high toxicity for normal cells. This toxicity is largely due to the binding of the hybrid protein to cells through the binding domain of the PE-A. In order to overcome this problem, a protein was recombinantly produced which contains only the enzymatic and "translocating" domains of Pseudomonas exotoxin A (Hwang et al., Cell, 48:129-137 1987). This protein was named PE 40 since it has a molecular weight of 40 kD. PE 40 lacks the binding domain of PE-A, and is unable to bind to mammalian cells. Thus, PE 40 is considerably less toxic than the intact 66 kD protein. As a result, hybrid "targeting-toxin" molecules produced with PE 40 were much more specific in their cellular toxicity (Chaudhary et al., Proc. Nat. Acad. Sci. USA, 84: 4583-4542 1987). While working with PE 40 , it was found that the cysteine residues at positions 265, 287, 372 and 379 (numbering from the native 66 kD PE-A molecules; Gray et al., Proc. Natl. Acad. Sci., USA, 81, 2645-2649 (1984)) interfered with the construction of "targeting-toxin" molecules using chemical conjugation methods. The reactive nature of the disulfide bonds that these residues form leads to ambiguity with regard to the chemical integrity of the product "targeting toxin". BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a map of plasmid pTACTGF57-PE 40 . DISCLOSURE STATEMENT 1. U.S. Pat. No. 4,545,985 teaches that pseudomonas exotoxin A can be conjugated to antibodies or to epidermal growth factor. U.S. Pat. No. 4,545,985 further teaches that these conjugates can be used to kill human tumor cells. 2. U.S. Pat. No. 4,664,911 teaches that antibodies can be conjugated to the A chain or the B chain of ricin which is a toxin obtained from plants. U.S. Pat. No. 4,664,911 further teaches, that these conjugates can be used to kill human tumor cells. 3. U.S. Pat. No. 4,675,382 teaches that hormones such as melanocyte stimulating hormone (MSH) can be linked to a portion of the diphtheria toxin protein via peptide bonds. U.S. Pat. No. 4,675,382 further teaches that the genes which encode these proteins can be joined together to direct the synthesis of a hybrid fusion protein using recombinant DNA techniques. This fusion protein has the ability to bind to cells that possess MSH receptors. 4. Murphy et al., PNAS USA 83:8258-8262 1986, Genetic construction, expression, and melanoma-selective cytotoxicity of a diphtheria toxin-related alpha-melanocyte-stimulating hormone fusion protein. This article teaches that a hybrid fusion protein produced in bacteria using recombinant DNA technology and consisting of a portion of the diphtheria toxin protein joined to alpha-melanocyte-stimulating hormone will bind to and kill human melanoma cells. 5. Kelley et al., PNAS USA 85:3980-3984 1988, Interleukin 2-diphtheria toxin fusion protein can abolish cell-mediated immunity in vivo. This article teaches that a hybrid fusion protein produced in bacteria using recombinant DNA technology and consisting of a portion of the diphtheria toxin protein joined to interleukin 2 functions in nude mice to suppress cell mediated immunity. 6. Allured et al., PNAS USA 83:1320-1324 1986, Structure of exotoxin A of Pseudomonas aeruginosa at 3.0 Angstrom. This article teaches the three dimensional structure of the pseudomonas exotoxin A protein. 7. Hwang et al., Cell 48:129-136 1987, Functional Domains of Pseudomonas Exotoxin Identified by Deletion Analysis of the Gene Expressed in E. Coli. This article teaches that the pseudomonas exotoxin A protein can be divided into three distinct functional domains responsible for: binding to mammalian cells, translocating the toxin protein across lysosomal membranes, and ADP ribosylating elongation factor 2 inside mammalian cells. This article further teaches that these functional domains correspond to distinct regions of the pseudomonas exotoxin A protein. 8. European patent application 0 261 671 published 30 Mar. 1988 teaches that a portion of the pseudomonas exotoxin A protein can be produced which lacks the cellular binding function of the whole pseudomonas exotoxin A protein but possesses the translocating and ADP ribosylating functions of the whole pseudomonas exotoxin A protein. The portion of the pseudomonas exotoxin A protein that retains the translocating and ADP ribosylating functions of the whole pseudomonas exotoxin A protein is called pseudomonas exotoxin - 40 or PE-40. PE-40 consists of amino acid residues 252-613 of the whole pseudomonas exotoxin A protein as defined in Gray et al., PNAS USA 81:2645-2649 1984. This patent application further teaches that PE-40 can be linked to transforming growth factor-alpha to form a hybrid fusion protein produced in bacteria using recombinant DNA techniques. 9. Chaudhary et al., PNAS USA 84:4538-4542 1987, Activity of a recombinant fusion protein between transforming growth factor type alpha and Pseudomonas exotoxin. This article teaches that hybrid fusion proteins formed between PE-40 and transforming growth factor-alpha and produced in bacteria using recombinant DNA techniques will bind to and kill human tumor cells possessing epidermal growth factor receptors. 10. Bailon et al., Biotechnology, pp. 1326-1329 Nov. 1988. Purification and Partial Characterization of an Interleukin 2-Pseudomonas Exotoxin Fusion Protein. This article teaches that hybrid fusion proteins formed between PE-40 and interleukin 2 and produced in bacteria using recombinant DNA techniques will bind to and kill human cell lines possessing interleukin 2 receptors. OBJECTS OF THE INVENTION It is an object of the present invention to provide modifications of PE 40 which provide improved chemical integrity and defined structure of conjugate molecules formed between "targeting agents" and modified PE 40 . It is another object of this invention to provide a method for preparing and recovering the modified PE 40 domain from fusion proteins formed between "targeting agents" and modified PE 40 . These and other objects of the present invention will be apparent from the following description. SUMMARY OF THE INVENTION The present invention provides modifications of the PE 40 domain which eliminate the chemical ambiguities caused by the cysteines in PE 40 . Substitution of other amino acids such as, e.g., alanine for the cysteine residues in PE 40 , or deletion of two or more of the cysteine residues improves the biological and chemical properties of the conjugates formed between modified PE 40 and a targeting agent. DETAILED DESCRIPTION OF THE INVENTION Hybrid molecules produced by conjugation of TGFα or EGF and PE 40 are characterized in three primary assay systems. These assays include: 1--ADP ribosylation of elongation factor 2 which measures the enzymatic activity of EGF-PE 40 or TGFα-PE 40 which inhibits mammalian protein synthesis, 2--inhibition of radiolabled EGF binding to the EGF receptor on membrane vesicles from A431 cells which measures the EGF receptor binding activity of EGF-PE 40 , or TGFα PE 40 and 3--cell viability as assessed by conversion of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) to formazan which is used to measure the survival of tumor cells following exposure to EGF-PE 40 or TGFα PE 40 . These assays are performed as previously described (Chung et al., Infection and Immunity, 16:832-841 1977, Cohen et al., J. Biol. Chem., 257:1523-1531 1982, Riemen et al., Peptides 8:877-885 1987, Mossman, J. Immunol. Methods, 65:55-63 1983). Briefly, to determine peptide binding to the EGF receptor, A431 membrane vesicles were incubated with radio-iodinated peptide; bound and unbound ligand were then separated by rapid filtration which retained the vesicles and associated radioligand. For most assays, the radioligand was 125 I-EGF obtained from New England Nuclear. For some assays, homogeneous (HPLC) EGF was radio-iodinated using Chloramine T. EGF binding assays were carried out in a total reaction volume of 100 μl in Dulbecco's phosphate-buffered saline (pH 7.4) containing 1% (w/v) Pentax Fraction V Bovine Serum Albumin, 1 nM 125 I-EGF (150 μCi/μg), and shed A431 plasma membrane vesicles (35 μ membrane protein). To assess non-specific binding, 100 nM unlabelled EGF or Peak IV was included in the assay. At time 0, the reaction was initiated by the addition of membrane vesicles. After 30 minutes at 37° C., the vesicles were collected on glass fiber filter mats and washed for 20 seconds with Dulbecco's phosphate-buffered saline, using a Skatron Cell Harvester, Model 7000. 125 I-EGF retained by the filters was then quantitated by gamma spectrometry. Assay points were performed in triplicate. Specifically, to determine cell killing activity, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide; Sigma catalog no. M2128) was dissolved in PBS at 5 mg/ml and filtered to sterilize and remove a small amount of insoluble residue present in some batches of MTT. At the times indicated below, stock MTT solution (10 μl per 100 μl medium) was added to all wells of an assay and plates were incubated at 37° C. for 4 h. Acid-isopropanol (100 μl of 0.04N NCl in isopropanol) was added to all wells and mixed thoroughly to dissolve the dark blue crystals. After a few minutes at room temperature to ensure that all crystals were dissolved, the plates were read on a Dynatech MR580 Microelisa reader, using a test wavelength of 570 nm, a reference wavelength of 630 nm, and a calibration setting of 1.99 (or 1.00 if the samples were strongly colored). Plates were normally read within 1 h of adding the isopropanol. We first produced a series of recombinant DNA molecules that encoded either TGF-alpha - PE 40 or specifically modified versions of TGF-alpha - PE 40 . The original or parental TGF-alpha - PE 40 gene was molecularly cloned in a bacterial TAC expression plasmid vector (pTAC TGF57-PE40) using distinct segments of cloned DNA as described in Example 1. The pTAC TGF57-PE40 DNA clone was used as the starting reagent for constructing specifically modified versions of TGF-alpha - PE 40 DNA. The specific modifications of the pTAC TGF57-PE 40 DNA involve site specific mutations in the DNA coding sequence required to replace two or four of the cysteine codons within the PE 40 domain of the pTAC TGF57-PE40 DNA with codons for other amino acids. Alternatively, the site specific mutations can be engineered to delete two or four of the cysteine codons within the PE40 domain of pTAC TGF57-PE40. The site specific mutations in the pTAC TGF57-PE40 DNA were constructed using the methods of Winter et al., Nature 299:756-758 1982. Specific examples of the mutated pTAC TGF57-PE40 DNAs are presented in Example 2. The amino acid sequence of the parent TGF-alpha - PE 40 is presented in Sequence ID No. 2. The four cysteine residues in the PE 40 domain of the parental TGF-alpha - PE 40 hybrid fusion protein are designated residues Cys 265 , Cys 287 , Cys 372 , and Cys 379 . Amino acid residues are numbered as defined for the native 66 kD PE-A molecule (Gray et al., Proc. Natl. Acad. Sci., USA, 81, 2645-2649 1984). The modified TGF-alpha - PE 40 fusion proteins used to generate the modified PE 40 molecules contain substitutions or deletions of residues [Cys 265 and Cys 287 ] or [Cys 372 and Cys 379 ], or [Cys 265 , Cys 287 , Cys 372 , and Cys 379 ]. To simplify the nomenclature for the modified PE 40 molecules generated from the modified fusion proteins, we have designated the amino acid residues at positions 265 and 287 as the "A" locus, and the residues at positions 372 and 379 the "B" locus. When cysteines are present at amino acid residues 265 and 287 as in the parental TGF-alpha - PE 40 fusion protein, the locus is capitalized (i.e. "A"). When the cysteines are substituted with other amino acids or deleted from residues 265 and 287, the locus is represented by a lower case "a". Similarly, when the amino acid residues at positions 372 and 379 are cysteines, the locus is represented by an upper case "B" while a lower case "b" represents this locus when the amino acid residues at positions 372 or 379 are substituted with other amino acids or deleted. Thus when all four cysteine residues in the PE 40 domain are substituted with alanines or deleted the modified PE 40 is designated PE 40 ab. In a similar fashion the parental PE 40 derived from the parental TGF-alpha - PE 40 fusion protein with cysteines at amino acid residue positions 265,287, 372, and 379 can be designated PE 40 AB. The source materials (i.e. the TGF-alpha - PE 40 AB hybrid protein, and the modified TGF-alpha - PE 40 Ab, aB and ab hybrid proteins), are produced in E. coli using the TAC expression vector system described by Linemeyer et al., Biotechnology 5:960-965 1987. The source proteins produced in these bacteria are harvested and purified by lysing the bacteria in guanidine hydrochloride followed by the addition of sodium sulfite and sodium tetrathionate. This reaction mixture is subsequently dialzyed and urea is added to solubilize proteins which have precipitated from solution. The mixture is centrifuged to remove insoluble material and the recombinant hybrid TGF-alpha - PE 40 source proteins are separated using ion exchange chromatography, followed by size exclusion chromatography, followed once again by ion exchange chromatography. Since the single methionine residue in the hybrid source proteins is located between the TGF-alpha and PE 40 domains, treatment with CNBr would cleave the source proteins, yielding the modified PE 40 proteins and TGF-alpha. The purified S-sulfonate derivatives of TGF-alpha - PE 40 are thus subjected to CNBr treatment to remove the TGF portion of the molecule. The desired modified PE 40 portion is purified by ion-exchange chromatography followed by size exclusion chromatography. The purified modified PE 40 is then derivatized with a suitable heterobifunctional reagent, e.g. SPDP, to allow conjugation of the desired targeting agent. Following conjugation, size exclusion chromatography is used to isolate the conjugate from non-conjugated materials. Once the purified conjugate is isolated, it is tested for biologic activity using the ADP-ribosylation assay and the relevant receptor binding and cell viability assays. The following examples illustrate the present invention without, however, limiting the same thereto. All of the enzymatic reactions required for molecular biology manipulations, unless otherwise specified, are carried out as described in Maniatis et al., (1982) In: Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Press. EXAMPLE 1 Construction of Recombinant DNA Clones Containing TGF-alpha - PE 40 DNA The TGF-alpha DNA segment was constructed using three sets of synthetic oligonucleotides as described by Defeo-Jones et al., Molecular and Cellular Biology 8:2999-3007 1988. This synthetic TGF-alpha gene was cloned into pUC-19. DNA from the pUC-19 clone containing recombinant human TGF-alpha was digested with Sph I and Eco RI. The digestion generated a 2.8 kb DNA fragment containing all of pUC-19 and the 5' portion of TGF-alpha. The 2.8 kb fragment was purified and isolated by gel electrophoresis. An Eco RI to Sph I oligonucleotide cassette was synthesized. This synthetic cassette had the sequence indicated in Sequence ID No. 3. For convenience, this oligonucleotide cassette was named 57. Cassette 57 was annealed and ligated to the TGF-alpha containing 2.8 kb fragment forming a circularized plasmid. Clones which contained the cassette were identified by hybridization to radiolabeled cassette 57 DNA. The presence of human TGF-alpha was confirmed by DNA sequencing. Sequencing also confirmed the presence of a newly introduced Fsp I site at the 3' end of the TGF-alpha sequence. This plasmid, named TGF-alpha-57/pUC-19, was digested with HinD III and Fsp I which generated a 168 bp fragment containing the TGF-alpha gene (TGF-alpha-57). A separate preparation of pUC-19 was digested with HinD III and Eco RI which generated a 2.68 kb pUC-19 vector DNA. The PE 40 DNA was isolated from plasmid pVC 8 (Chaudhary et al., PNAS USA 84:4538-4542 1987). pVC 8 was digested using Nde I. A flush end was then generated on this DNA by using the standard conditions of the Klenow reaction (Maniatis et al., supra, p.113). The flush-ended DNA was then subjected to a second digestion with Eco RI to generate a 1.3 kb Eco RI to Nde I (flush ended) fragment containing PE 40 . The TGF-alpha-57 HinD III to Fsp I fragment (168 bp) was ligated to the 2.68 kb pUC-19 vector. Following overnight incubation, the 1.3 kb EcoRI to Nde I (flush ended) PE 40 DNA fragment was added to the ligation mixture. This second ligation was allowed to proceed overnight. The ligation reaction product was then used to transform JM 109 cells. Clones containing TGF-alpha-57 PE 40 in pUC-19 were identified by hybridization to radiolabeled TGF-alpha-57 PE 40 DNA and the DNA from this clone was isolated. The TGF-alpha-57 PE 40 was removed from the pUC-19 vector and transferred to a TAC vector system described by Linemeyer et al., Bio-Technology 5:960-965 1987). The TGF-alpha-57 PE 40 in pUC-19 was digested with HinD III and Eco RI to generate a 1.5 kb fragment containing TGF-alpha-57 PE 40 . A flush end was generated on this DNA fragment using standard Klenow reaction conditions (Maniatis et al., op. cit.). The TAC vector was digested with HinD III and Eco RI. A flush end was generated on the digested TAC vector DNA using standard Klenow reaction conditions (Maniatis et al., op. cit. The 2.7 kb flush ended vector was isolated using gel electrophoresis. The flush ended TGF-alpha-57 PE 40 fragment was then ligated to the flush ended TAC vector. The plasmid generated by this ligation was used to transform JM 109 cells. Candidate clones containing TGF-alpha-57 PE 40 were identified by hybridization as indicated above and sequenced. The clone containing the desired construction was named pTAC TGF57-PE 40 . The plasmid generated by these manipulations is depicted in FIG. 1. The nucleotide sequence of the amino acid codons of the TGF-alpha - PE 40 fusion protein encoded in the pTAC TGF-57-PE40 DNA are depicted in Sequence ID No. 1. The amino acid sequence encoded by the TGF-57-PE40 gene is shown in Sequence ID No. 2. EXAMPLE 2 Construction of Modified Versions of Recombinant TGF-alpha - PE 40 Containing DNA Clones: Substitution of Alanines for Cysteines. TGF-alpha - PE 40 aB: The clone pTAC TGF57-PE40 was digested with SphI and BamHI and the 750 bp SphI-BamHI fragment (specifying the C-terminal 5 amino acids of TGF-alpha and the N-terminal 243 amino acids of PE 40 ) was isolated. M13 mp19 vector DNA was cut with SphI and BamHI and the vector DNA was isolated. The 750 bp SphI-BamHI TGF-alpha - PE 40 fragment was ligated into the M13 vector DNA overnight at 15° C. Bacterial host cells were transformed with this ligation mixture, candidate clones were isolated and their plasmid DNA was sequenced to insure that these clones contained the proper recombinant DNAs. Single stranded DNA was prepared for mutagenesis. An oligonucleotide (oligo #132) was synthesized and used in site directed mutagenesis to introduce a HpaI site into the TGF-alpha - PE 40 DNA at amino acid position 272 of PE 40 : 5' CTGGAGACGTTAACCCGTC 3' (See Sequence ID No. 4) One consequence of this site directed mutagenesis was the conversion of residue number 272 in PE 40 from phenylalanine to leucine. The mutagenesis was performed as described by Winter et al., Nature, 299:756-758 1982. A candidate clone containing the newly created HpaI site was isolated and sequenced to validate the presence of the mutated genetic sequence. This clone was then cut with SphI and SalI. A 210 bp fragment specifying the C-terminal 5 amino acids of TGF-alpha and the N-terminal 70 amino acids of PE 40 and containing the newly introduced HpaI site was isolated and subcloned back into the parent pTAC TGF57-PE40 plasmid at the SphI-SalI sites. Bacterial host cells were transformed, a candidate clone was isolated and its plasmid DNA was sequenced to insure that this clone contained the proper recombinant DNA. For convenience this clone was named pTAC TGF57-PE40-132. pTAC TGF57-PE40-132 was digested with SphI and HpaI and a 3.96 Kb DNA fragment was isolated. A synthetic oligonucleotide cassette (oligo #153 See Sequence ID No. 5) spanning the C-terminal 5 amino acids of TGF-alpha and the N-terminal 32 amino acids of PE 40 and containing SphI and HpaI compatible ends was synthesized and ligated to the digested pTAC TGF57-PE40-132. This oligonucleotide cassette incorporated a change in the TGF-alpha - PE 40 DNA so that the codon specifying cysteine at residue 265 now specified alanine. For convenience this plasmid DNA was called pTAC TGF57-PE40-132,153. Bacterial host cells were transformed with pTAC TGF57-PE40-132,153 DNA. Candidate clones were identified by hybridization, isolated and their plasmid DNA was sequenced to insure that it contained the proper recombinant DNA. pTAC TGF57-PE40-132,153 DNA was digested with HpaI and SalI and a 3.95 Kb vector DNA was isolated. A synthetic oligonucleotide cassette (oligo #142 see Sequence ID No. 6) spanning amino acid residues 272 to 309 of PE 40 and containing HpaI and SalI compatible ends was synthesized and ligated to the 3.95 Kb pTAC TGF/PE40 132,153 DNA. This oligonucleotide cassette changes the codon specifying cysteine at residue 287 so that this codon now specifies alanine. For convenience this mutated plasmid DNA was called pTAC TGF57-PE40-132,153,142. Bacterial host cells were transformed with this plasmid and candidate clones were identified by hybridization. These clones were isolated and their plasmid DNA was sequenced to insure that it contained the proper recombinant DNA. The pTAC TGF57-PE40-132,153,142 plasmid encodes the TGF-alpha - PE 40 variant with both cysteines at locus "A" replaced by alanines. Therefore, following the nomenclature described previously this modified version of TGF-alpha - PE 40 is called TGF-alpha - PE 40 aB. The amino acid sequence encoded by the TGF-alpha-PE 40 aB gene is shown in Sequence ID No. 7. TGF-alpha - PE 40 Ab: The clone pTAC TGF57-PE 40 was digested with SphI and BamHI and the 750 bp SphI-BamHI fragment (specifying the C-terminal 5 amino acids of TGF-alpha and the N-terminal 252 amino acids of PE40) was isolated. M13 mp19 vector DNA was cut with SphI and BamHI and the vector DNA was isolated. The 750 bp SphI-BamHI TGF-alpha - PE 40 fragment was ligated into the M13 vector DNA overnight at 15° C. Bacterial host cells were transformed with this ligation mixture, candidate clones were isolated and their plasmid DNA was sequenced to insure that these clones contained the proper recombinant DNAs. Single stranded DNA was prepared for mutagenesis. An oligonucleotide (oligo #133 Sequence ID No. 8) was synthesized and used in site directed mutagenesis to introduce a BsteII site into the TGF-alpha - PE 40 DNA at amino acid position 369 of PE 40 . One consequence of this mutagenesis was the conversion of the serine residue at position 369 of PE 40 to a threonine. A DNA clone containing the newly created BsteII site was identified, isolated and sequenced to ensure the presence of the proper recombinant DNA. This clone was next digested with ApaI and SalI restriction enzymes. A 120 bp insert DNA fragment containing the newly created BsteII site was isolated and ligated into pTAC TGF57-PE40 that had also been digested with ApaI and SalI. Bacterial host cells were transformed, and a candidate clone was isolated and sequenced to insure that the proper recombinant DNA was present. This newly created plasmid DNA was called pTAC TGF57-PE40-133. It was digested with BsteII and ApaI and 2.65 Kb vector DNA fragment was isolated. A BsteII to ApaI oligonucleotide cassette (oligo #155 Sequence ID No. 9) was synthesized which spanned the region of TGF-alpha - PE 40 deleted from the pTAC TGF57-PE40-133 clone digested with BsteII and ApaI restriction enzymes. This cassette also specified the nucleotide sequence for BsteII and ApaI compatible ends. This oligonucleotide cassette changed the codons for cysteines at residues 372 and 379 of PE 40 to codons specifying alanines. Oligonucleotide cassette #155 was ligated to the 2.65 Kb vector DNA fragment. Bacterial host cells were transformed and candidate clones were isolated and sequenced to insure that the proper recombinant DNA was present. This newly created DNA clone was called pTAC TGF57-PE40-133,155. It encodes the TGF-alpha - PE 40 variant with both cysteines at locus "B" replaced by alanines. Therefore, following the nomenclature described previously this modified version of TGF-alpha - PE 40 is called TGF-alpha - PE 40 Ab. The amino acid sequence encoded by the TGF-alpha-PE 40 Ab gene is shown in Sequence ID No. 10. TGF-alpha - PE 40 ab: The pTAC-TGF57-PE40-132,153,142 plasmid encoding TGF-alpha - PE 40 aB was digested with SalI and ApaI and the resultant 3.8 Kb vector DNA fragment was isolated. The pTAC TGF57-PE40-133,155 plasmid encoding TGF-alpha - PE 40 Ab was also digested with SalI and ApaI and the resultant 140 bp DNA fragment containing the cysteine to alanine changes at amino acid residues 372 and 379 of PE 40 was isolated. These two DNAs were ligated together and used to transform bacterial host cells. Candidate clones were identified by hybridization with a radiolabeled 140 bp DNA from pTAC TGF57-PE40-133,155. Plasmid DNA from the candidate clones was isolated and sequenced to insure the presence of the proper recombinant DNA. This newly created DNA clone was called pTAC TGF57-PE40-132,153,142,133,155. This plasmid encodes the TGF-alpha - PE 40 variant with all four cysteines at loci "A" and "B" replaced by alanines. Therefore, following the nomenclature described previously this modified version of TGF-alpha - PE 40 is called TGF-alpha - PE 40 ab. The amino acid sequence encoded by the TGF-alpha-PE 40 ab gene is shown in Sequence ID No. 11. EXAMPLE 3 Production and Isolation of Recombinant TGF-alpha - PE 40 Source Proteins Transformed E. coli JM-109 cells were cultured in 1 L shake flasks in 500 mL LB-Broth in the presence of 100 ug/mL ampicillin at 37° C. After the A 600 spectrophotometric absorbance value reached 0.6, isopropyl B-D-thiogalactopyranoside was added to a final concentration of 1 mM. After 2 hours the cells were harvested by centrifugation. The cells were lysed in 8M guanidine hydrochloride, 50 mM Tris, 1 mM EDTA, pH 8.0 by stirring at room temperature for 2 hours. The lysis mixture was brought to 0.4M sodium sulfite and 0.1M sodium tetrathionate by adding solid reagents and the pH was adjusted to 9.0 with 1M NaOH. The reaction was allowed to proceed at room temperature for 16 hours. The protein solution was dialysed against a 10,000 fold excess volume of 1 mM EDTA at 4° C. The mixture was then brought to 6M urea, 50 mM NaCl, 50 mM Tris, pH 8.0, at room temperature and stirred for 2 hours. Any undissolved material was removed by centrifugation at 32,000×g for 30 minutes. The cleared supernatant from the previous step was applied to a 26×40 cm DEAE Sepharose Fast-Flow column (Pharmacia LKB Biotechnology, Inc.) equilibrated with 6M urea, 50 mM Tris, 50 mM NaCl, pH 8.0, at a flow rate of 1 mL/minute. The column was washed with the equilibration buffer until all unadsorbed materials were removed as evidenced by a UV A 280 spectrophotometric absorbance below 0.1 in the equilibration buffer as it exits the column. The adsorbed fusion protein was eluted from the column with a 1000 mL 50-350 mM NaCl gradient and then concentrated in a stirred cell Amicon concentrator fitted with a YM-30 membrane. The concentrated fusion protein (8 mL) was applied to 2.6×100 cm Sephacryl S-300 column (Pharmacia LKB Biotechnology, Inc.) equilibrated with 6M urea, 50 mM Tris, 50 mM NaCl, pH 8.0, at a flow rate of 0.25 mL/minute. The column was eluted with additional equilibration buffer and 3 mL fractions collected. Fractions containing TGF-alpha - PE 40 activity were pooled. The pooled fractions from the S-300 column were applied to a 1.6×40 cm Q Sepharose Fast-Flow column (Pharmacia LKB Biotechnology, Inc.) equilibrated with 6M urea, 50 mM Tris, 50 mM NaCl, pH 8.0 at a flow rate of 0.7 mL/minute. The column was washed with the equilibration buffer and then eluted with a 600 mL 50-450 mM NaCl gradient. The fractions containing the TGF-alpha - PE 40 activity were pooled and then dialyzed against 50 mM glycine pH 9.0 and stored at -20° C. EXAMPLE 4 CNBR Cleavage of TGF-alpha - PE 40 Source Proteins and Isolation of Modified PE 40 s (PE 40 AB, PE 40 Ab, PE 40 aB, PE 40 ab). The desired fusion protein, still in the S-sulfonated form, is dialysed versus 10% (v/v) acetic acid in water, then lyophilized. The lyophilized protein is dissolved in a sufficient amount of deaerated 0.1M HCl to give a protein concentration of 1 mg/mL. The protein/HCl solution contains 5 moles tryptophan/mole fusion protein. CNBr (500 equivalents per equivalent of methionine) is added, and the reaction allowed to proceed for 18 hours, at room temperature in the dark. Large digestion fragments, including the desired modified PE 40 , are then separated from the reaction mixture by gel filtration (e.g., Sephadex G-25) in 25% acetic acid (v/v). Fractions containing the modified PE 40 are pooled and lyophilized. In the case of the modified proteins containing cysteine (i.e PE 40 AB, PE 40 aB, and PE 40 Ab) it is necessary to form the requisite disulfide bonds before proceeding with purification. The lyophilized protein is therefore dissolved in a sufficient amount of 50 mM glycine, pH 10.5 to give a UV A 280 =0.1. Beta-mercaptoethanol is added to give a 4:1 molar ratio over the theoretical number of S-sulfonate groups present in the protein sample. The reaction is allowed to proceed for 16 hours at 4° C., after which time the solution is dialysed against a 10,000 fold excess of a buffer containing 20 mM Tris, i mM EDTA, 100 mM NaCl, pH 8.0. Fractions from the anion exchange column containing the desired PE 40 are pooled based on ADP-ribosylation activity and protein content as determined by SDS-PAGE. The pooled fractions are concentrated using a 30,000 molecular weight cutoff membrane (YM-30, Amicon). The pooled fractions are applied to a 2.6×100 cm Sephacryl S-200 gel filtration column (Pharmacia LKB Biotechnology, Inc.), equilibrated in, and eluted with 20 mM Tris, 50 mM NaCl, 1 mM EDTA, pH 8.0 at a flow rate of 0.75 mL/minute. Fractions from the gel filtration chromatography are pooled based on ADP-ribosylation and SDS-PAGE. Though this procedure yields material sufficiently pure for most purposes, another chromatographic step is included in order to produce highly homogeneous material. This final chromatographic step is high resolution gel filtration, using a 0.75×60 cm Bio-Sil TSK-250 column (Bio-Rad). In preparation for chromatography on the TSK-250 column, samples are concentrated on Centriprep-30 devices (Amicon) and protein concentration adjusted to 5 mg/mL. The sample is dissolved in 6M urea, 100 mM sodium phosphate, 100 mM NaCl, pH 7.1. The column is eluted with 6M urea, 100 mM sodium phosphate, 100 mM NaCl, pH 7.1, at a flow rate of 0.5 mL/minute. Fractions from the high resolution gel filtration step are pooled based on ADP-ribosylation and SDS-PAGE. EXAMPLE 5 Conjugation of EGF to Modified PE 40 s and Isolation of Conjugates In order to conjugate EGF to modified PE 40 , it is necessary to derivatize both the EGF and PE40 with heterobifunctional agents, so that a covalent connection between the two molecules can be achieved. In preparation for the derivatization, samples of modified PE 40 are dialyzed against 0.1M NaCl, 0.1M sodium phosphate, pH 7.0. Following dialysis, the solution of modified PE 40 is adjusted to 4 mg/mL PE 40 using the dialysis buffer, giving a concentration of 100 uM. A sufficient amount of a 20 mM solution of N-succinimidyl 3-(3-pyridyldithio)propionate (SPDP, Pierce) in ethanol is added to the protein solution to give a final concentration of 300 uM SPDP. This concentration represents a 3:1 ratio of SPDP to PE 40 . The derivatization reaction is allowed to proceed at room temperature for 30 minutes, with occasional agitation of the mixture. The reaction is terminated by adding a large excess of glycine (approximately a 50-fold molar excess over the initial amount of SPDP). The resulting 3-(2-pyridyldithio)propionyl-derivative is called PDP-PE 40 . The non-protein reagents are removed from the product by extensive dialysis versus 6M urea, 0.1M NaCl, 0.1M sodium phosphate, pH 7.5. The number of PDP-groups introduced into the modified PE 40 is determined as described by Carlsson et al., Biochem. J., 173:723-737 1978. The PDP-EGF derivative is prepared by dissolving lyophilized EGF (Receptor grade, Collaborative Research) in a sufficient amount of 0.1M NaCl, 0.1M sodium phosphate, pH 7.0 to give a final concentration of 150 uM EGF. A sufficient amount of a 20 mM solution of SPDP in ethanol is added to the EGF solution to give a final concentration of 450 uM SPDP, representing a 3:1 ratio of SPDP to EGF. The derivatization reaction is allowed to proceed at room temperature for 30 minutes, with occasional agitation of the mixture. The reaction is terminated by adding a large excess of glycine (approximately a 50-fold molar excess over the initial amount of SPDP). The non-protein reagents are removed from the product by extensive dialysis versus 6M urea, 0.1M NaCl, 0.1M sodium phosphate, pH 7.5. The number of PDP-groups introduced into EGF is determined as described by Carlsson et al., Biochem. J., 173:723-737 1978. Using the derivatives described above, either PDP-PE 40 or PDP-EGF can be reduced at acidic pH, in order to generate the 3-thiopropionyl derivative, in the presence of the intact, native disulfides (Carlsson et al., supra). However, the preferred strategy is the generation of a free thiol on the modified PE 40 . PDP-PE 40 (0.4 ml of a 100 uM solution of PDP-PE 40 in 6M urea, 0.1M NaCl, 0.1M sodium phosphate, pH 7.5) is dialyzed against several 500 mL changes of a buffer containing 6M urea, 25 mM sodium acetate, pH 5.5, at 4° C. Following the dialysis, 20 uL of 100 mM dithiothreitol (final concentration 5 mM) is added to the PDP-PE 40 . The reduction is allowed to proceed for 10 minutes at room temperature, and is then terminated by dialysis of the reaction mixture against 6M urea, 25 mM sodium acetate, 1 mM EDTA, pH 5.5, at 4° C. Dialysis against this buffer is repeated, and then the sample is dialyzed against 0.1M NaCl, 0.1M sodium phosphate, pH 7.5. The material generated by these manipulations is called thiopropionyl-PE 40 . In preparation for conjugation, PDP-EGF (0.8 mL of a 150 uM solution in 6M urea, 0.1M NaCl, 0.1M sodium phosphate, pH 7.5) is dialyzed against several changes of 0.1M NaCl, 0.1M sodium phosphate, pH 7.5, at 4° C., to free the sample of urea. Following this dialysis, the PDP-EGF solution and the thiopropionyl-PE 40 solution are combined and the reaction mixture is incubated at room temperature for 1 hour. The progress of the reaction can be monitored by measuring the release of pyridine-2-thione as described (Carlsson et al., supra). The reaction is terminated by dialysis against several changes of 6M urea, 0.1M NaCl, 0.1M sodium phosphate, pH 7.5, at 4° C. The conjugates are purified by size exclusion chromatography, using a high resolution 0.75×60 cm Bio-Sil TSK-250 column (Bio-Rad). The column is eluted with 6M urea, 0.1M sodium phosphate, 0.1M NaCl, pH 7.1, at a flow rate of 0.5 mL/minute. Fractions from the high resolution gel filtration step are pooled based on ADP-ribosylation and SDS-PAGE. Biological Activities of TGF-alpha - PE 40 AB, TGF-alpha - PE 40 Ab, TGF-alpha - PE 40 aB, and TGF-alpha - PE 40 ab Proteins The hybrid fusion proteins TGF-alpha-PE 40 AB, TGF-alpha - PE 40 Ab, TGF-alpha - PE 40 aB, TGF-alpha - PE 40 ab were expressed in bacterial hosts and isolated as described above. Each protein was then characterized for its ability to inhibit the binding of radiolabeled epidermal growth factor to the epidermal growth factor receptor on A431 cell membrane vesicles and for its ability to kill A431 cells as measured in MTT cell proliferation assays. The following table summarizes the biological activities of these proteins: ______________________________________ EPIDERMAL GROWTH FACTOR A431 CELL RECEPTOR BINDING KILLING IC.sub.50 nM EC.sub.50 pM______________________________________TGF-alpha - PE.sub.40 AB 346 47TGF-alpha - PE.sub.40 -AB 588 25TGF-alpha - PE40 aB 27 151TGF-alpha - PE40 ab 60 392______________________________________ __________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 11(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1260 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:ATGGCTGCAGCAGTGGTGTCCCATTTTAATGACTGCCCAGATTCCCACACTCAGTTCTGC60TTCCATGGAACATGCAGGTTTTTGGTGCAGGAGGACAAGCCGGCATGTGTCTGCCATTCT120GGGTACGTTGGTGCGCGCTGTGAGCATGCGGACCTCCTGGCTGCTATGGCCGAAGAGGGC180GGCAGCCTGGCCGCGCTGACCGCGCACCAGGCTTGCCACCTGCCGCTGGAGACTTTCACC240CGTCATCGCCAGCCGCGCGGCTGGGAACAACTGGAGCAGTGCGGCTATCCGGTGCAGCGG300CTGGTCGCCCTCTACCTGGCGGCGCGGCTGTCGTGGAACCAGGTCGACCAGGTGATCCGC360AACGCCCTGGCCAGCCCCGGCAGCGGCGGCGACCTGGGCGAAGCGATCCGCGAGCAGCCG420GAGCAGGCCCTGGCCCTGACCCTGGCCGCCGCCGAGAGCGAGCGCTTCGTCCGGCAGGGC480ACCGGCAACGACGAGGCCGGCGCGGCCAACGCCGACGTGGTGAGCCTGACCTGCCCGGTC540GCCGCCGGTGAATGCGCGGGCCCGGCGGACAGCGGCGACGCCCTGCTGGAGCGCAACTAT600CCCACTGGCGCGGAGTTCCTCGGCGACGGCGGCGACGTCAGCTTCAGCACCCGCGGCACG660CAGAACTGGACGGTGGAGCGGCTGCTCCAGGCGCACCGCCAACTGGAGGAGCGCGGCTAT720GTGTTCGTCGGCTACCACGGCACCTTCCTCGAAGCGGCGCAAAGCATCGTCTTCGGCGGG780GTGCGCGCGCGCAGCCAGGACCTCGACGCGATCTGGCGCGGTTTCTATATCGCCGGCGAT840CCGGCGCTGGCCTACGGCTACGCCCAGGACCAGGAACCCGACGCACGCGGCCGGATCCGC900AACGGTGCCCTGCTGCGGGTCTATGTGCCGCGCTCGAGCCTGCCGGGCTTCTACCGCACC960AGCCTGACCCTGGCCGCGCCGGAGGCGGCGGGCGAGGTCGAACGGCTGATCGGCCATCCG1020CTGCCGCTGCGCCTGGACGCCATCACCGGCCCCGAGGAGGAAGGCGGGCGCCTGGAGACC1080ATTCTCGGCTGGCCGCTGGCCGAGCGCACCGTGGTGATTCCCTCGGCGATCCCCACCGAC1140CCGCGCAACGTCGGCGGCGACCTCGACCCGTCCAGCATCCCCGACAAGGAACAGGCGATC1200AGCGCCCTGCCGGACTACGCCAGCCAGCCCGGCAAACCGCCGCGCGAGGACCTGAAGTAA1260(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 420 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:MetAlaAlaAlaValValSerHisPheAsnAspCysProAspSerHis151015ThrGlnPheCysPheHisGlyThrCysArgPheLeuValGlnGluAsp202530LysProAlaCysValCysHisSerGlyTyrValGlyAlaArgCysGlu354045HisAlaAspLeuLeuAlaAlaMetAlaGluGluGlyGlySerLeuAla505560AlaLeuThrAlaHisGlnAlaCysHisLeuProLeuGluThrPheThr65707580ArgHisArgGlnProArgGlyTrpGluGlnLeuGluGlnCysGlyTyr859095ProValGlnArgLeuValAlaLeuTyrLeuAlaAlaArgLeuSerTrp100105110AsnGlnValAspGlnValIleArgAsnAlaLeuAlaSerProGlySer115120125GlyGlyAspLeuGlyGluAlaIleArgGluGlnProGluGlnAlaArg130135140LeuAlaLeuThrLeuAlaAlaAlaGluSerGluArgPheValArgGln145150155160GlyThrGlyAsnAspGluAlaGlyAlaAlaAsnAlaAspValValSer165170175LeuThrCysProValAlaAlaGlyGluCysAlaGlyProAlaAspSer180185190GlyAspAlaLeuLeuGluArgAsnTyrProThrGlyAlaGluPheLeu195200205GlyAspGlyGlyAspValSerPheSerThrArgGlyThrGlnAsnTrp210215220ThrValGluArgLeuLeuGlnAlaHisArgGlnLeuGluGluArgGly225230235240TyrValPheValGlyTyrHisGlyThrPheLeuGluAlaAlaGlnSer245250255IleValPheGlyGlyValArgAlaArgSerGlnAspLeuAspAlaIle260265270TrpArgGlyPheTyrIleAlaGlyAspProAlaLeuAlaTyrGlyTyr275280285AlaGlnAspGlnGluProAspAlaArgGlyArgIleArgAsnGlyAla290295300LeuLeuArgValTyrValProArgSerSerLeuProGlyPheTyrArg305310315320ThrSerLeuThrLeuAlaAlaProGluAlaAlaGlyGluValGluArg325330335LeuIleGlyHisProLeuProLeuArgLeuAspAlaIleThrGlyPro340345350GluGluGluGlyGlyArgLeuGluThrIleLeuGlyTrpProLeuAla355360365GluArgThrValValIleProSerAlaIleProThrAspProArgAsn370375380ValGlyGlyAspLeuAspProSerSerIleProAspLysGluGlnAla385390395400IleSerAlaLeuProAspTyrAlaSerGlnProGlyLysProProArg405410415GluAspLeuLys420(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 25 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:CGGACCTCCTGGCTGCGCATCTAGG25(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 19 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:CTGGAGACGTTAACCCGTC19(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 84 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:CGGACCTCCTGGCCATGGCCGAAGAGGGCGGCAGCCTGGCCGCGCTGACCGCGCACCAGC60TGCACACCTGCCGCTGGAGACGTT84(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 107 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:AACCCGTCATCGCCAGCCGCGCGGCTGGGAACAACTGGAGCAGGCTGGCTATCCGGTGCA60GCGGCTGGTCGCCCTCTACCTGGCGGCGCGGCTGTCGTGGAACCAGG107(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 420 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:MetAlaAlaAlaValValSerHisPheAsnAspCysProAspSerHis151015ThrGlnPheCysPheHisGlyThrCysArgPheLeuValGlnGluAsp202530LysProAlaCysValCysHisSerGlyTyrValGlyAlaArgCysGlu354045HisAlaAspLeuLeuAlaAlaMetAlaGluGluGlyGlySerLeuAla505560AlaLeuThrAlaHisGlnAlaAlaHisLeuProLeuGluThrLeuThr65707580ArgHisArgGlnProArgGlyTrpGluGlnLeuGluGlnAlaGlyTyr859095ProValGlnArgLeuValAlaLeuTyrLeuAlaAlaArgLeuSerTrp100105110AsnGlnValAspGlnValIleArgAsnAlaLeuAlaSerProGlySer115120125GlyGlyAspLeuGlyGluAlaIleArgGluGlnProGluGlnAlaArg130135140LeuAlaLeuThrLeuAlaAlaAlaGluSerGluArgPheValArgGln145150155160GlyThrGlyAsnAspGluAlaGlyAlaAlaAsnAlaAspValValSer165170175LeuThrCysProValAlaAlaGlyGluCysAlaGlyProAlaAspSer180185190GlyAspAlaLeuLeuGluArgAsnTyrProThrGluAlaGluPheLeu195200205GlyAspGlyGlyAspValSerPheSerThrArgGlyThrGlnAsnTrp210215220ThrValGluArgLeuLeuGlnAlaHisArgGlnLeuGluGluArgGly225230235240TyrValPheValGlyTyrHisGlyThrPheLeuGluAlaAlaGlnSer245250255IleValPheGlyGlyValArgAlaArgSerGlnAspLeuAspAlaIle260265270TrpArgGlyPheTyrIleAlaGlyAspProAlaLeuAlaTyrGlyTyr275280285AlaGlnAspGlnGluProAspAlaArgGlyArgIleArgAsnGlyAla290295300LeuLeuArgValTyrValProArgSerSerLeuProGlyPheTyrArg305310315320ThrSerLeuThrLeuAlaAlaProGluAlaAlaGlyGluValGluArg325330335LeuIleGlyHisProLeuProLeuArgLeuAspAlaIleThrGlyPro340345350GluGluGluGlyGlyArgLeuGluThrIleLeuGlyTrpProLeuAla355360365GluArgThrValValIleProSerAlaIleProThrAspProArgAsn370375380ValGlyGlyAspLeuAspProSerSerIleProAspLysGluGlnAla385390395400IleSerAlaLeuProAspTyrAlaSerGlnProGlyLysProProArg405410415GluAspLeuLys420(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 17 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:GACGTGGTGACCCTGAC17(2) INFORMATION FOR SEQ ID NO:9:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 43 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:GTGACCCTGACCGCGCCGGTCGCCGCCGGTGAAGCTGCGGGCC43(2) INFORMATION FOR SEQ ID NO:10:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 420 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:MetAlaAlaAlaValValSerHisPheAsnAspCysProAspSerHis151015ThrGlnPheCysPheHisGlyThrCysArgPheLeuValGlnGluAsp202530LysProAlaCysValCysHisSerGlyTyrValGlyAlaArgCysGlu354045HisAlaAspLeuLeuAlaAlaMetAlaGluGluGlyGlySerLeuAla505560AlaLeuThrAlaHisGlnAlaCysHisLeuProLeuGluThrPheThr65707580ArgHisArgGlnProArgGlyTrpGluGlnLeuGluGlnCysGlyTyr859095ProValGlnArgLeuValAlaLeuTyrLeuAlaAlaArgLeuSerTrp100105110AsnGlnValAspGlnValIleArgAsnAlaLeuAlaSerProGlySer115120125GlyGlyAspLeuGlyGluAlaIleArgGluGlnProGluGlnAlaArg130135140LeuAlaLeuThrLeuAlaAlaAlaGluSerGluArgPheValArgGln145150155160GlyThrGlyAsnAspGluAlaGlyAlaAlaAsnAlaAspValValThr165170175LeuThrAlaProValAlaAlaGlyGluAlaAlaGlyProAlaAspSer180185190GlyAspAlaLeuLeuGluArgAsnTyrProThrGlyAlaGluPheLeu195200205GlyAspGlyGlyAspValSerPheSerThrArgGlyThrGlnAsnTrp210215220ThrValGluArgLeuLeuGlnAlaHisArgGlnLeuGluGluArgGly225230235240TyrValPheValGlyTyrHisGlyThrPheLeuGluAlaAlaGlnSer245250255IleValPheGlyGlyValArgAlaArgSerGlnAspLeuAspAlaIle260265270TrpArgGlyPheTyrIleAlaGlyAspProAlaLeuAlaTyrGlyTyr275280285AlaGlnAspGlnGluProAspAlaArgGlyArgIleArgAsnGlyAla290295300LeuLeuArgValTyrValProArgSerSerLeuProGlyPheTyrArg305310315320ThrSerLeuThrLeuAlaAlaProGluAlaAlaGlyGluValGluArg325330335LeuIleGlyHisProLeuProLeuArgLeuAspAlaIleThrGlyPro340345350GluGluGluGlyGlyArgLeuGluThrIleLeuGlyTrpProLeuAla355360365GluArgThrValValIleProSerAlaIleProThrAspProArgAsn370375380ValGlyGlyAspLeuAspProSerSerIleProAspLysGluGlnAla385390395400IleSerAlaLeuProAspTyrAlaSerGlnProGlyLysProProArg405410415GluAspLeuLys420(2) INFORMATION FOR SEQ ID NO:11:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 420 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:MetAlaAlaAlaValValSerHisPheAsnAspCysProAspSerHis151015ThrGlnPheCysPheHisGlyThrCysArgPheLeuValGlnGluAsp202530LysProAlaCysValCysHisSerGlyTyrValGlyAlaArgCysGlu354045HisAlaAspLeuLeuAlaAlaMetAlaGluGluGlyGlySerLeuAla505560AlaLeuThrAlaHisGlnAlaAlaHisLeuProLeuGluThrLeuThr65707580ArgHisArgGlnProArgGlyTrpGluGlnLeuGluGlnAlaGlyTyr859095ProValGlnArgLeuValAlaLeuTyrLeuAlaAlaArgLeuSerTrp100105110AsnGlnValAspGlnValIleArgAsnAlaLeuAlaSerProGlySer115120125GlyGlyAspLeuGlyGluAlaIleArgGluGlnProGluGlnAlaArg130135140LeuAlaLeuThrLeuAlaAlaAlaGluSerGluArgPheValArgGln145150155160GlyThrGlyAsnAspGluAlaGlyAlaAlaAsnAlaAspValValThr165170175LeuThrAlaProValAlaAlaGlyGluAlaAlaGlyProAlaAspSer180185190GlyAspAlaLeuLeuGluArgAsnTyrProThrGlyAlaGluPheLeu195200205GlyAspGlyGlyAspValSerPheSerThrArgGlyThrGlnAsnTrp210215220ThrValGluArgLeuLeuGlnAlaHisArgGlnLeuGluGluArgGly225230235240TyrValPheValGlyTyrHisGlyThrPheLeuGluAlaAlaGlnSer245250255IleValPheGlyGlyValArgAlaArgSerGlnAspLeuAspAlaIle260265270TrpArgGlyPheTyrIleAlaGlyAspProAlaLeuAlaTyrGlyTyr275280285AlaGlnAspGlnGluProAspAlaArgGlyArgIleArgAsnGlyAla290295300LeuLeuArgValTyrValProArgSerSerLeuProGlyPheTyrArg305310315320ThrSerLeuThrLeuAlaAlaProGluAlaAlaGlyGluValGluArg325330335LeuIleGlyHisProLeuProLeuArgLeuAspAlaIleThrGlyPro340345350GluGluGluGlyGlyArgLeuGluThrIleLeuGlyTrpProLeuAla355360365GluArgThrValValIleProSerAlaIleProThrAspProArgAsn370375380ValGlyGlyAspLeuAspProSerSerIleProAspLysGluGlnAla385390395400IleSerAlaLeuProAspTyrAlaSerGlnProGlyLysProProArg405410415GluAspLeuLys420__________________________________________________________________________

Pseudomonas exotoxin 40 is modified by deleting or substituting one or more cysteine residues. Such a modified protein, when hybridized to TGFα, exhibits altered biological activities from unmodified TGFα PE 40 , including decreased cell killing activity and increased receptor-binding activity.

PRIORITY CLAIM [0001] This application claims the benefit of previously filed U.S. Provisional Patent Application entitled “HUB-BASED ELECTRONIC LOCK SYSTEMS AND DEVICES,” assigned U.S. Ser. No. 61/924,319, filed Jan. 7, 2014, and which is incorporated herein by reference for all purposes. FIELD OF THE SUBJECT MATTER [0002] The presently disclosed subject matter relates to locks. More particularly, the presently disclosed subject matter relates to electronic locks and related systems, and corresponding and/or related methodologies. BACKGROUND OF THE SUBJECT MATTER [0003] Generally speaking, the use of various lock structures is well known in a number of different environments, for a large variety of items for which various forms of protection (i.e., physical security) is desired. Locks of many different types have been in existence for hundreds of years. Unfortunately, for just as long a period of time, there have been individuals who have sought to illicitly gain access to the protected item or area for which or on which the lock was installed. Many occasions arise that require electronic access control of different types of cabinets, entryway doors, carts, tool boxes, and other types of boxes, hereafter regardless generally of their compositions, materials, or configurations collectively referred to as an enclosure or cabinet. Such enclosures or cabinets may be provided with doors and/or may also include drawers. [0004] The need for access control usually arises from the lack of sufficient security often provided by typical lock and key mechanisms. For example, a mechanical key may be lost or stolen. Once such a lost or stolen key has been surreptitiously obtained by an unauthorized individual, such individual in possession of such key may easily access the secured enclosure to either steal its contents or, as in the case of secured medical records or other confidential documents, view its contents. Further, when such enclosures or cabinets are accessed, there is typically no record that it has been accessed, let alone who accessed it or when such access took place. [0005] Such shortcomings of keyed mechanical locks have contributed to the creation of the specialized field of electronic access control. [0006] Typically, electronic access control may correspond to a three part system, including, for example: (1) a credential reader, (2) a microprocessor based control circuit, and (3) an electronic latch to mechanically open or unlock the enclosure being secured by the access control system. [0007] Credential readers may include, but are not limited to: keypads, magnetic stripe card readers, proximity card readers, “ibuttons,” smart card readers, and/or bar code card readers. More recently, there has been progress in the field of biometrics resulting in the ability to reliably read and discern an individual's fingerprints, handprints, and retina and/or facial features. [0008] Generally speaking, credential and/or biometric readers convert their applicable credential or biometric features, respectively, into a binary number or digital code. A microprocessor based system then reads and analyzes such binary number or digital code. Such systems are typically either standalone (attached to the reader) or networked (attached to many readers). Typically, they may read the binary number that corresponds to the potential entrant's credential or biometric features and compare it to a list of pre-approved binary numbers. In such fashion, the microprocessor based system determines if the potential entrant has the right to access the enclosure or cabinet being secured by the access control system. [0009] If the microprocessor based system determines that the subject credential or biometric feature under consideration is valid, access is granted to the enclosure. Typically, such is accomplished by the microprocessor turning on an electronic control circuit corresponding to solid state devices or relays which in turn provide a useable electrical voltage to open an electronic latch mechanism. [0010] There are generally speaking various types of electronic latch mechanisms, such as slam latches or dead bolt latches. Typically, dead bolt latches may utilize a fixed dead bolt without means of a spring return. Such types of latches instead make use of an electronic control circuit to actuate a motor or solenoid such as to alternately retract and/or extend a dead bolt in order to provide the locking (or unlocking) action. In other words, a locking action is typically not “automatic” when the enclosure door is closed. [0011] The prime mover in some types of latches may typically either be a solenoid or a motor/gear train combination. Solenoid based latches having equal strength to a given motor/gear train based latch are often significantly larger and heavier than such “equivalent” motor/gear train design. [0012] Latches constructed in accordance with the presently disclosed subject matter are in many instances preferably motor based. A representative example of such a latch is shown by the commonly owned U.S. Pat. No. 8,403,376 or a simple electronically controlled solenoid based latch may be used. [0013] U.S. Pat. No. 7,768,378 discloses apparatus and methodology for providing a retrofittable lock assembly. The retrofittable lock contains electronic circuitry that maintains a record of user identification, date, and time of access of users seeking access to items stored in the enclosure. [0014] U.S. Pat. No. 8,199,019 discloses apparatus and methodology for temperature monitoring and controlled access to refrigerated medications. An electronically controlled lock is installed on a refrigerator used for storage of temperature sensitive medications. Lock access is given to individuals having differing levels of access authorization so that user level authorization holders may have access to stored medications. [0015] U.S. Patent Application Publication No. 20110012709 discloses apparatus and methodology for data control in an electronic access control system. A plurality of electronic locks are connected to a central server over a network such as an 802.11 WiFi wireless network that may be used to provide data updates and management for the individual electronic locks. To address power management problems associated with electronic locks having the capability to communicate over an 802.11 WiFi network, method and apparatus are provided for selectively powering on and off an 802.11 WiFi communications module integrated into the electronic lock to conserve power resources. An electronic access control system allows efficient data exchange between a central server and a plurality of electronic locks using a database structure, and allows for multiple simultaneous database manipulations. [0016] U.S. Pat. No. 8,742,889 discloses apparatus and methodology for providing electronic access control, including use of a retrofittable electronic lock to provide secure storage to an enclosure. A user interface and LCD visual display permit adjustment of system operational parameters. In certain embodiments, the electronic access control system includes master-slave control capabilities and/or inventory management capability. Secure storage of the enclosure is provided when the enclosure is being moved or otherwise transported from one location to another location. Various alternative arrangements provide various alert features, as well as battery features which facilitate their rapid replacement and/or reconfiguration. [0017] The foregoing patent related publications, all commonly owned with the subject application, are hereby fully incorporated by reference herein for all purposes. [0018] Generally speaking, it would be desirable to have use of an electronic lock system which provided a number of hub-based electronic lock control features, for expanding the ability to electronically control electronic lock components. Further, it would be desirable to provide such a hub-based system with additional features, such as audit trail capabilities, where for each lock or latch, the hub-based system would be able to monitor, report, and log when each latch or lock opens/closes and when each associate door switch opens/closes. Still further, it would be desirable to provide a hub-based system which has the ability to independently control a number of latches though through use of a single user interface. With such an arrangement, a user would be able to operate/open a plurality of latches from the one interface, without needing to relocate and manipulate a plurality of respective displays. At the same time, it would be desirable with such an arrangement to still provide for selective programming of a single lock instead of having to identically program all locks at the same time. [0019] While various implementations of electronic lock mechanisms and systems have been developed, no design has emerged that generally encompasses all of the desired characteristics as hereafter presented in accordance with the subject technology. SUMMARY OF THE SUBJECT MATTER [0020] In view of the recognized features encountered in the prior art and addressed by the presently disclosed subject matter, improved apparatus and methodology are provided for expanding existing electronic lock control systems for operation in a hub-based environment. More particularly, improved apparatus and methodology are provided for operation in a hub-based environment but also providing additional control features, such as audit trail features. Other control features may for some embodiments relate to management of power resources such as battery resources. [0021] The presently disclosed subject matter generally relates to lock or access control systems, and more particularly to electronically controlled lock systems such as may be applied to various storage enclosures or cabinets to provide secure storage of various items, equipment, materials, and/or information within the enclosures or cabinets. More specifically, certain present aspects may relate to hub and/or daisy-chained control for a plurality of electronic locks used in an electronic access control system, for inventory management using electronic locks, and/or to electronic locks with various features including display screens, access controls and tracking, and alert capabilities. In other present aspects, the presently disclosed subject matter provides for the ability to use a single interface as opposed to many, to set up and operate either of a single or many locks. [0022] One such exemplary embodiment relates to a hub-based electronic lock access control system for use with a plurality of storage enclosures of the type having respectively at least an exterior portion and a securable interior portion for secure storage. Such a system preferably has a microprocessor based access control circuit having a hub output for providing control data for respective locks; a connection hub, having an input for receiving control data from such control circuit, and having a plurality of respective control outputs for providing respective control signals to respective associated electronic locks responsive thereto; a plurality of respective electronic locks associated with such connection hub and respective storage enclosures, such electronic locks configured to be unlocked by such access control circuit via such connection hub; and memory, associated with such access control circuit, for storage of data associated with access control circuit activity and with contents of an associated storage enclosure. [0023] In certain of such systems, the connection hub may include a hub output for providing control signals via such connection hub from such control circuit to another connection hub in a daisy-chained configuration therewith. In other of such arrangements, the exemplary system may further comprise a plurality of such connection hubs in a daisy-chained configuration, for controlling a plurality of electronic locks respectively associated therewith, all controlled by such access control circuit via such plurality of connection hubs. In yet other alternatives of the foregoing, each of such connection hubs may respectively include a hub identification switch for selection of an identification position of the respective hub in a daisy-chained configuration. [0024] In still other present variations, the foregoing exemplary control circuit may control operational power to such respective locks via such connection hub. [0025] Other present alternatives involve systems further comprising a user interface configured to provide a user access to such access control circuit through input data verified by such microprocessor, wherein such access control circuit is configured to unlock such locks based on input data verified by such microprocessor. In still others, such user interface may be further configured to provide a user access to such memory for selective input of preprogrammed codes reflecting either of removal or addition of securely stored contents of the storage enclosures for updating of data in such memory, for coded tracking of stored contents in an enclosure, whereby a user with verified input data can obtain both access control circuit activity data and updated stored contents data from such memory for reporting on a given associated enclosure. For some such systems, a user with verified input data may be able to access and name selected of such electronic locks. [0026] For other present variations, a hub-based electronic lock access control system may further include a plurality of communications modules respectively associated with each of such plurality of electronic locks and communicating over a network including connections which are one of hardwired and wireless connections. [0027] In others thereof, such microprocessor based access control circuit and such connection hub respectively may have power inputs for connection to respective battery power sources. In certain of those alternatives, the hub-based electronic lock access control system may further include respective battery power sources connected with such respective connection hubs, wherein such connection hubs are configured for sharing battery power from such battery power sources, for respectively providing operational power to selected electronic locks being controlled thereby. In yet other present alternatives, a present system may be further configured for controlling such respective battery power sources connected with such respective connection hubs, so that the level of operational power from such battery power sources to selected electronic locks is controlled. [0028] In others, such microprocessor based access control circuit may comprise a main control box having a hub-supporting circuit board in an expansion port thereof. [0029] In some of such alternatives, such microprocessor based access control circuit may be configured for determining operational characteristics of the electronic locks associated with the hub-based electronic lock access control system. [0030] Yet other present variations may further include at least one sensor associated with at least one of such electronic locks for providing feedback to the associated hub on operation of such associated at least one electronic lock. [0031] For others, such microprocessor based access control circuit may be configured for operation per a user-determined mode of operation for simultaneously operating all of the electronic locks associated with the hub-based electronic lock access control system or for individually operating such electronic locks. [0032] Yet another present exemplary embodiment may relate to a connection hub for use in a hub-based electronic lock access control system for control of a plurality of storage enclosures. Preferably, such an exemplary connection hub may comprise an input for receiving control data thereto from a control circuit; a plurality of respective control outputs for providing respective control signals to respective associated electronic locks responsive thereto; and a power input for alternative connection of such connection hub to a battery power source. [0033] In some such exemplary embodiments, such connection hub may further include a hub output for providing control signals via such connection hub from the control circuit to another connection hub in a daisy-chained configuration therewith. In yet others, the embodiment may further comprise a plurality of such connection hubs in a daisy-chained configuration, for controlling a plurality of electronic locks respectively associated therewith, all controlled by an access control circuit via such plurality of connection hubs. For others, each of such connection hubs may respectively include a hub identification switch for selection of an identification position of the respective hub in a daisy-chained configuration. [0034] Yet other present variations may relate to an exemplary such connection hub further including respective battery power sources connected with each of such respective connection hubs, wherein such connection hubs are configured for sharing battery power from such battery power sources, for respectively providing operational power to selected electronic locks being controlled thereby. [0035] In others thereof, such alternative connection hub embodiments may be configured for supplying operational power to respective associated locks. [0036] In still other variations, a present exemplary connection hub may further include at least one sensor input thereto, associated with at least one associated electronic lock for providing feedback to such connection hub on operation of such associated at least one electronic lock. [0037] In certain broader aspects, various presently disclosed exemplary embodiments relate to either of apparatus or to corresponding and/or associated methodology, as will be understood by those of ordinary skill in the art. [0038] One such present exemplary methodology relates to secured inventory management through use of an electronic access control system from a central system via the use of a hub-based control arrangement, for use with securable storage enclosures of the type having at least an exterior portion and a securable interior portion. Such exemplary methodology preferably may comprise providing a microprocessor based access control circuit having a hub output for providing control data for respective locks; interconnecting a connection hub with such hub output, so as to receive control data from the control circuit; providing a plurality of respective electronic locks associated with such connection hub and with respective storage enclosures, such electronic locks configured to be unlocked by such access control circuit via such connection hub; and providing respective control signals to respective associated electronic locks responsive thereto, via a plurality of respective control outputs from the connection hub. [0039] Variations of such methodology may further include providing memory, associated with the access control circuit, for storage of data associated with access control circuit activity and with contents of an associated storage enclosure for reporting on the access activity for an associated storage enclosure. [0040] Others may include providing a plurality of such connection hubs in a daisy-chained configuration, for controlling a plurality of electronic locks respectively associated therewith, all controlled by the access control circuit via such plurality of connection hubs. Still others may further include selectively identifying the position of each respective connection hub in a daisy-chained configuration. [0041] As will be understood from the complete disclosure herewith, other present alternative methodology may further include providing and controlling power to selected of the electronic locks from a plurality of respective battery power sources connected with the respective connection hubs. In some instances, alternative methodology may simply further include selectively providing operational power to the respective locks via the connection hub. [0042] Other exemplary present methodology may further include providing a plurality of communications modules respectively associated with each of the plurality of electronic locks and communicating over a network including connections which are one of hardwired and wireless connections. [0043] Still further variations may further include automatically determining operational characteristics of the electronic locks associated with the hub-based electronic lock access control system. For some such variations, such automatically determining may include automatically determining whether and what specific types of latches are associated with the hub-based electronic lock access control system. [0044] Yet other variations may further include sensing the operation of associated electronic locks; and selectively operating in user-determined modes of operation for simultaneously operating all of the electronic locks associated with the hub-based electronic lock access control system or for individually operating such electronic locks. [0045] Further, various presently disclosed embodiments may involve various combinations and mixtures of hardwired components and programmable components and associated software. [0046] Additional objects and advantages of the presently disclosed subject matter are set forth in, or will be apparent to, those of ordinary skill in the art from the detailed description herein. Also, it should be further appreciated that modifications and variations to the specifically illustrated, referred and discussed features, elements, and steps hereof may be practiced in various embodiments, uses, and practices of the presently disclosed subject matter without departing from the spirit and scope of the subject matter. Variations may include, but are not limited to, substitution of equivalent means, features, or steps for those illustrated, referenced, or discussed, and the functional, operational, or positional reversal of various parts, features, steps, or the like. [0047] Still further, it is to be understood that different embodiments, as well as different presently preferred embodiments, of the presently disclosed subject matter may include various combinations or configurations of presently disclosed features, steps, or elements, or their equivalents (including combinations of features, parts, or steps or configurations thereof not expressly shown in the figures or stated in the detailed description of such figures). Additional embodiments of the presently disclosed subject matter, not necessarily expressed in the summarized section, may include and incorporate various combinations of aspects of features, components, or steps referenced in the summarized objects above, and/or other features, components, or steps as otherwise discussed in this application. Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the remainder of the specification, and will appreciate that the presently disclosed subject matter applies equally to corresponding methodologies as associated with practice of any of the present exemplary devices, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS [0048] A full and enabling disclosure of the presently disclosed subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: [0049] FIG. 1 is a schematic overview of an existing (Prior Art) system which has the capabilities of controlling two separate electronic latches; [0050] FIG. 2 is a schematic overview of an exemplary embodiment of the presently disclosed hub-based electronic lock system operable in accordance with the presently disclosed subject matter; [0051] FIG. 3 is a schematic overview of a further exemplary embodiment of the presently disclosed hub-based electronic lock system operable in a daisy-chained configuration in accordance with the presently disclosed subject matter; [0052] FIG. 4 is an isometric, generally side and partial top view of an exemplary hub-based electronic lock embodiment, configured with an exemplary electronic latch and associated door switch embodiment, in accordance with the presently disclosed subject matter; [0053] FIGS. 5A and 5B are a generally top perspective view, and an enlarged isolated portion thereof, respectively, of an exemplary hub component for an electronic lock constructed in accordance with the presently disclosed subject matter; and [0054] FIGS. 6 through 16 are representative screenshots, respectively, of various functionalities which may be provided in accordance with exemplary embodiments of the presently disclosed subject matter. [0055] Repeat use of reference characters throughout the present specification and appended drawings is intended to represent same or analogous features, elements, or steps of the presently disclosed subject matter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0056] As discussed in the Summary of the Subject Matter section, the presently disclosed subject matter is particularly concerned with improved apparatus and methodology for electronic lock systems and related functionality. [0057] Further, presently disclosed subject matter relates to a programmable electronic lock system having the ability to control a plurality of electronic locks from a central system via the use of a hub-based control arrangement. In one such exemplary embodiment, up to eight electronic locks may be controlled through a single hub-based configuration. [0058] Yet further, a plurality of such hub-based configurations may be arranged in a daisy-chained embodiment for controlling either higher numbers of electronic locks, in accordance with presently disclosed subject matter. For example, per one presently disclosed exemplary embodiment, up to 32 electronic locks may be controlled, arranged in four latching hubs of eight each. [0059] Selected combinations of aspects of the disclosed technology correspond to a plurality of different embodiments of the presently disclosed subject matter. It should be noted that each of the exemplary embodiments presented and discussed herein should not insinuate limitations of the presently disclosed subject matter. Features or steps illustrated or described as part of one embodiment may be used in combination with aspects of another embodiment to yield yet further embodiments. Additionally, certain features may be interchanged with similar devices, features, or steps not expressly mentioned which perform the same or similar function. [0060] Reference will now be made in detail to the presently preferred embodiments of the subject electronic lock and related technology. [0061] A typical standard electronic lock product most frequently secures a single door or drawer. For example, a code may be entered or a validation access card may be presented, either of which once validated, may cause an electronic mechanism to allow the credential-presented (user) to access the secured door or drawer. It is also typical that if there multiple drawers or doors to be secured, there are respectively multiple lock systems. Such multiplicity can contribute to significant costs, complications, and difficulty, particularly when a supervisory level or similar user attempts to manage in such a multiple electronic lock environment. The presently disclosed subject matter enables such a higher level user to manage (control) multiple electronic locks/latches associated with multiple doors or drawers, through the use of a single, integrated electronic lock system. [0062] FIG. 1 herewith is a schematic overview of an existing (Prior Art) system having a main control box 10 which has the capability of respectively controlling two separate electronic latches 12 and 14 . As noted above, such electronic latches 12 and 14 may comprise devices as represented and disclosed in commonly owned U.S. Pat. No. 8,403,376 or a simple electronically controlled solenoid based latch may be used. As represented in present FIG. 1 , such main control box 10 has a port which serves in effect as an expansion port by receiving a circuit board 16 specially configured for handling the two respective latches 12 and 14 as illustrated through the one control box. As shown, each such latch has a representative wired connection 18 and 20 for which a wireless or other connection could be substituted, as well understood by those of ordinary skill in the art. Further, the prior existing control box may be accessed for validation and for control input such as through a display (generally 22 ) which has a keyboard 24 and/or other input capabilities, as well understood by those of ordinary skill in the art. Such communications may take place through a wired connection 26 or through alternative connections. Still further, as represented by FIG. 1 , a power supply 28 (such as a representative 9 Volt power supply) may be connected through wiring 30 for powering such main control box 10 , as well as for powering latches 12 and 14 through wiring 18 and 20 , respectively. [0063] As illustrated by FIG. 1 , prior existing technology permits validated inputs to a control box to be used in turn to respectively manipulate up to two separate electronic latches, using power from a battery source or other power input. [0064] The presently disclosed subject matter, in some embodiments thereof, permits validated control and related functionality (such as activity tracking) for up to 32 electronic locks, operated in groups of eight through a hub-based arrangement driven through a common control box. [0065] FIG. 2 provides a schematic overview of an exemplary embodiment of the presently disclosed hub-based electronic lock system operable in accordance with the presently disclosed subject matter. In this exemplary embodiment of presently disclosed subject matter, a main control box 110 includes a circuit board 116 in an expansion port thereof. Such circuit board 116 , as disclosed herein, amounts to a hub-supporting circuit board. Main control box 110 may have also an associated display 122 such as with keyboard 124 and other inputs as will be well understood by those of ordinary skill in the art. [0066] A representative hub 102 is illustrated as having a respective input 104 and output 106 . Output 106 constitutes an auxiliary output for use in a daisy-chained configuration, as further discussed herein with reference to application FIG. 3 . As illustrated by FIG. 2 , main control box 110 may communicate via wiring 108 with the input 104 of hub 102 . As represented, exemplary hub 102 in turn has eight electronic lock control outputs, such as respectively associated with representative electronic locks (latches) 112 and 114 , which conduct communications and power thereto via respective wirings 118 and 120 . Other numbers of associated electronic locks/latches may be practiced in particular embodiments. [0067] Similar to FIG. 1 , a power supply 128 (such as a 9 Volt power supply) may be provided and communicative with main control box 110 via wiring 130 . Unlike FIG. 1 , FIG. 2 represents that a further power source 132 , such as a further battery power supply, may be communicative with hub 102 via wiring 134 . As understood by those of ordinary skill in the art from the complete disclosure herewith, operation of the hub embodiment 102 as presently disclosed herewith results in distribution of power through hub 102 to the respective latches, configured as illustrated. Such power may be in part or in whole drawn from source 128 or source 132 , or other sources, as discussed herein. [0068] In addition to providing control signals and power to the respective electronic locks, it is to be understood that data such as condition or status data may be obtained from such electronic locks and/or from doors or drawers associated respectively therewith. [0069] FIG. 3 provides a schematic overview of a further exemplary embodiment of the presently disclosed hub-based electronic lock system operable in a daisy-chained configuration generally 200 in accordance with the presently disclosed subject matter. In the particular embodiment illustrated, each of four respective hubs can in turn drive up to eight latches, for a total of 32 latches. [0070] The illustrated daisy-chained arranged is specified as follows. A main control box generally 210 is fitted with a circuit board 216 which adapts control box 210 for operation in a successive hub (or daisy-chained) configuration. An output cable or wiring 208 from control box 210 is connected to a control input connection on hub 202 , similar to the arrangement of present FIG. 2 and input 104 of hub 102 . However, thereafter, via wiring or cable 248 , a control output from hub 202 is fed into the control input of the second hub, hub 236 . Still further in turn, the output control of second hub 236 is fed via wiring 250 into the control input of the third hub, hub 238 . Yet further, the control output of hub 238 is fed via wiring or cable 252 to the control input a fourth hub, hub 240 . [0071] Per such daisy-chained configuration, control inputs after validation are passed along from device 222 into main control box 210 , and from there are input to selected electronic locks via one of the four respective hubs. [0072] Those of ordinary skill in the art will understand from the complete disclosure herewith that fewer than four hubs may be practiced and/or fewer than eight latches per hub may be practiced, all within the scope of the presently disclosed subject matter. Similarly, different configurations or arrangements and different types of latches may be practiced in various combinations, all of which are intended as being represented by the multiple hub exemplary embodiment of present FIG. 3 . [0073] As will also be understood from the complete disclosure herewith, in addition to power supply 228 and optional power 232 , as earlier discussed with reference to the single hub embodiment of present FIG. 2 (see power supplies 128 and 132 and their related discussions), further optional power supplies 242 , 244 , and 246 may be respectively provided in direct association with the second, third, and fourth hubs 236 , 238 , and 240 , respectively. Such power supplies may be operated for selective sharing of power therefrom, as further discussed herein. [0074] FIG. 4 is an isometric, generally side and partial top view of an exemplary hub-based electronic lock embodiment, configured with an exemplary electronic latch and associated door switch embodiment, in accordance with the presently disclosed subject matter, as may be used with either a single hub or multiple (plural) hub embodiment of the presently disclosed subject matter. As represented, hub generally 302 may be associated with at least one electronic latch 312 , with hub 302 and latch 312 communicating via wiring or cable 318 . As will be understood, latch 312 is in turn associated with a physical structure to which access is either granted or denied by operation of latch 312 in response to control signals via wiring 318 . For example, the associated physical structure may have either of a door or drawer or other structure which may be either opened or closed, for access or denial of access, respectively. If a door, a switch such as representative switch 354 may provide feedback to hub 302 via wiring 356 and 358 regarding whether an associated door is either closed or open. Other forms of feedback or sensors may be implemented, so long as hub 302 obtains data regarding the actual condition (opened or closed) of the structure associated with electronic latch 312 . [0075] As will be understood, other such switches 354 or equivalents may be used with each structure associated with an electronic latch associated with hub 302 . In particular, as represented by FIG. 4 , each position (of representative positions 1 through 8 ) of hub 302 may provide a connector arrangement suitable for association with wiring or cable 318 , and may provide connector(s) arrangement features suitable for use with wiring for an associated switch 354 . With such embodiments, any number of the electronic latches associated with hub 302 may each have their own respective feedback switch, for indicating the status (closed or opened) of their respective associated structure (door, drawer, etc.). [0076] Thus, when considering such subject matter on a per hub component basis, while each hub component may control up to 8 latches, it can also monitor up to 8 door switches. Preferably, such door switches may be field installed by the end user to monitor the state (open/closed) of the door that the latch is locking. Such operation may be desired because the state of the latch (locked/unlocked) is not necessarily indicative of the state of the door (open/closed). Thus, such door position switch may be used for multiple purposes, each of which is optional and controllable by the operator. They may include alarming if the door is left ajar for a preset number of minutes, alarming if the door is broken into, as well as email/test/voice/fax if the cabinet is ajar or broken into. [0077] FIG. 5A illustrates a generally top perspective view of an exemplary hub component 402 for an electronic lock system constructed in accordance with the presently disclosed subject matter. FIG. 5B illustrates an enlarged, isolated portion of such exemplary FIG. 5A subject matter. [0078] More specifically, hub 402 may include a variety of connections, per indications 460 through 480 . As understood from other disclosure herewith, multiple positions are made available on hub 402 for providing control and power connections and other feedback as discussed herein, and as reflected in part by connection indications 460 through 474 , respectively. A power supply, either battery powered or otherwise, may be connected to hub 402 through connector indication 476 . As indicated, 9 to 12 Volts would be a nominal input for such connection, useful for powering any of the devices in the overall illustrated components and system. Connector indications 478 and 480 represent input and output portions, respectively, and as otherwise discussed herein. [0079] Further, as represented by present FIG. 5B , a hub identification switch generally 482 may be provided for selection of an identification position of the hub 402 , particularly useful in daisy-chained arrangements otherwise described herein. The enlarged, isolated view of FIG. 5B represents that such hub identification switch generally 482 may include a specific switch setting 484 for designating the associated hub as either of hubs 1 , 2 , 3 , or 4 in a given configuration. In other words, such functionality allows the user to configure the hub-based technology in any configuration they choose (for example, 1, 2, 3, 4 or 4, 3, 2, 1 or 1, 3, 2, 4 etc.). [0080] The functionality resulting from the presently disclosed subject matter, whether achieved through hardwired and/or programmed components, may include a number of features. A key point is that, particularly when using a fully implemented, 32 electronic lock daisy-chained configuration, the system collectively will allow full control over all 32 locks/latches from a single input 222 device. The system advantageously automatically determines which latches and what specific types of latches are attached to/associated with the subject electronic lock system. As noted above, each of these latches can either be an electronic latch of the type of commonly owned U.S. Pat. No. 8,403,376 or a simple solenoid based latch. The electronics will know if a latch is connected by the presence/absence, for example, of a resistor on each connector (which will be integral to the interconnect cable). In turn, the size of such resistor may indicate to the electronics whether such an electronic lock or instead a solenoid-based device, or whether nothing is connected. It is also possible to vary the PWM of the solenoid hold voltage to indicate whether larger or smaller solenoids. [0081] Another resulting feature is that once such identification is accomplished, a user will have the ability to assign a name to each respective electronic latch. [0082] Another advantageous feature of the presently disclosed subject matter is that once the electronic locks are configured in a desired system, the user (particularly at the supervisor level) has the ability to select which specific latch to open or whether to open all latches simultaneously. In such context, it may be further established that it is required to meet other conditions (including physical conditions) in order to be able to open all latches simultaneously. [0083] The subject centrally controlled electronic lock system has the ability for an operator or user to assign access rights between a particular user and lock and respectively to each of its sublatches (for example, treating all locks or latches associated with a given hub as being sublatches or sublocks of such hub). Each respective hub has a selectable address so that among the representative four hubs, they may be daisy-chained in any order, using the hub identification switch generally 482 and specific switch setting 484 in order to specify the position (order) of the hubs as desired. [0084] Each latch at each hub also has additional position inputs, as referenced in conjunction with switch 354 of FIG. 4 , for enabling position monitoring of the state of an associated door or drawer secured by the respective latch. Particularly where such configuration is practiced in accordance with presently disclosed subject matter, it is possible to store records on detailed audit trail data that the subject hub-based electronic latch system generates. Collectively, the system makes it possible to create and maintain a full audit trail of who opened which latch together with reporting of the optional switch state changes. For example, when reporting whenever each latch opens/closes and when each door switch opens/closes, an audit trail may be generated as represented by Table 1 herewith. [0000] TABLE 1 Lock User Type of Alarm Date of Time of Name Name Access Status Notes Entry Entry Hub admin N/A Audit trail Aug. 27, 2013 2:49:35 PM System viewed Aug. 27, 2013 2:49PM Hub N/A N/A 26th Latch Aug. 27, 2013 2:49:12 PM System Latch Closed Hub N/A N/A Latch1 Aug. 27, 2013 2:49:12 PM System closed. Hub N/A N/A 26th Latch Aug. 27, 2013 2:49:04 PM System Latch Opened Hub admin N/A Audit trail Aug. 27, 2013 2:49:19 PM System viewed Aug. 27, 2013 2:49PM Hub Mike Card PROXCARD Access Aug. 27, 2013 2:48:56 PM System New granted. Hub admin N/A Audit trail Aug. 27, 2013 2:48:28 PM System viewed Aug. 27, 2013 2:48PM Hub N/A N/A Ajar alarm Aug. 27, 2013 2:48:20 PM System cleared Hub N/A N/A Hub 2 latch Aug. 27, 2013 2:48:20 PM System five Door Closed Hub N/A N/A Door Alarm Aug. 27, 2013 2:48:06 PM System Alarm: Ajar; Ajar for 10 seconds [0085] One aspect of certain presently disclosed exemplary embodiments relates to control of associated power supplies, particularly battery-based power supplies. As will be understood by those of ordinary skill in the art, beyond the powering of electronics of the various electronic lock components disclosed herewith, there are “drive” electronics power needs, chiefly related to operation of the various latches/locks. For example, power is required to drive motors and/or solenoids of such electronic devices. [0086] Power for the overall system may come from the power supply (such as power supply 128 of present FIG. 2 ) associated with the main control box 110 , or from each hub component separately (per the referenced “optional power” devices, such as optional power supply 132 of present FIG. 2 ). [0087] Preferably, there is a selection behavior embedded in controlling software that allows an operator to choose the mode of operation, for example, all latches operated simultaneously or the selection of one. Per presently disclosed subject matter, if simultaneous action is chosen, each hub component must have its optional power supply connected to facilitate actuation of each latch/lock. Each electronic latch can draw one amp (or more) on start up, and such amount of current requires sufficient (that is, separate) power supplies if more than one latch needs to start simultaneously. The presently disclosed subject matter makes use of slow/staggered starting of associated latch motors if available power becomes limited (such as due to inadequately sized or charged power supplies). The resulting feature may be thought of as specific power management capabilities resulting in latch motor current control improvement. [0088] With reference to such latch motor current control improvement, to maximize the current available to start a latch motor when running from a weak battery or power-limited mains supply, a latch motor control circuit will monitor the input voltage while using pulse width modulation (PWM) to vary the relationship between motor current and supply current. For example, for supply voltages which are close to nominal value, the latch motor will be almost fully “on”. For supply voltages significantly below nominal, the PWM duty cycle will be reduced in such fashion to keep the current drawn from the supply from drawing the supply voltage below half its nominal value. For supply voltages above nominal, the duty cycle will be reduced so as to limit motor currents to approximately what they would be at nominal supply voltage, thus avoiding excess stress on the motor and preventing it from running excessively fast. [0089] As a result of such control methodology, the resulting approach allows good motor performance to be achieved when using a wide variety of power sources including batteries or wall supplies, with all adaptation occurring fully automatically. The latch will operate, slowly, with batteries that would be too weak to drive the latch if it were otherwise switched “full on”. While users of such electronic latch may not particularly like having latch operations under some conditions take as much as five seconds until such time as the battery is replaced, the ability to still operate is far preferable to having the electronic latch simply be unusable. [0090] For the specific exemplary embodiments illustrated herewith, having nominal voltage level inputs of 9 to 12 Volts DC, one example is to control the unit so that it tries to limit the effective latch voltage to about 9 volts. This means that input voltages higher than such selected limit will result in a reduction through desired manipulation of the PWM input control. Because of the maximum amount of power that can be drawn from a 9 volt battery, in order to allow for some operation (albeit at a greatly reduced), the PWM value is controlled to start ramping down, for example, at around 8 Volts but ramps to nearly zero, for example, just below about 5 Volts. It is to be understood that alternative specific operational points may be selected, in order to vary the activity as desired, and all such variations are intended as encompassed by the broader control disclosure herewith. [0091] The following disclosure makes reference to exemplary screenshots of a user's interface with an exemplary embodiment of software for control access to the electronic lock system presently disclosed. In particular, the exemplary screenshots indicate how a user is granted access on a per latch basis with the subject electronic system. It will be understood by those of ordinary skill in the art that appropriate software implementation (in other words, programming) may be undertaken based on the description herewith, which implies various flow chart and/or methodology aspects based on such description and the accompanying Figures. [0092] It is also to be understood that the exemplary embodiment herewith makes use of various identifiers and/or file names which are arbitrarily selected for purposes of this example, as opposed to forming any limitation on the presently disclosed subject matter. In other words, alternative designation names may be selected by those practicing the presently disclosed subject matter to satisfy their own preferences and/or needs, without departing from the spirit and scope of such presently disclosed subject matter. [0093] The exemplary screenshot represented by present FIG. 6 illustrates a user's interface with a standard lock editing task. In the particular example hereof, a user is creating a new electronic lock implementation identified as “StorageCabinet.” After selecting the icon “Latch Configuration” of the FIG. 6 screenshot, a user is presented with a screenshot such as represented by present FIG. 7 . As shown, selecting “Latch Configuration” enables the user to choose the number of latches. In the indicated example, such activity may involve selecting from single, dual, or multiple. [0094] The FIG. 8 exemplary screenshot illustrates that upon choosing the option “Dual Latch,” a user may then choose a mode of operation. In the illustrated example, it is intended that selection of the designation or mode of operation “open with latch 1 ” means that both latches (of the “dual” latches) will open simultaneously. Selecting the choice “open with dual credential” in the illustrated example (present FIG. 8 ) means that two respective credentials are required. For example, a designated first latch opens with a first shown credential while a designated second latch opens when a corresponding second credential is shown. Swiping of a debit card followed by entry of a PIN is an example of a dual credential arrangement. In the illustrated example, selection of the mode of operation listed as “independent control” means that reference to both of the dual latches appears in an access rights screen, which enables the operator to respectively grant access to them independently. [0095] Present FIG. 9 illustrates an exemplary screenshot of choices available to a user/operator of a presently disclosed electronic lock system if “Multiple Latch” is selected. In particular, such a selection then permits the operator to choose a mode of operation. As represented by such present FIG. 9 , one available selection referenced as “open all” means that all latches that a user has access to will open simultaneously after a valid credential is shown. If instead a mode of operation listed for purposes of present example as “single selectable” is selected, then the subject electronic lock system queries the user to identify which latch to open after a valid credential is shown. Based on control data otherwise loaded into the electronic lock system, the system will only offer as choices those latches for which the user is already cleared for access. [0096] The representative screenshot illustration of present FIG. 9 also shows default latch names, and shows that all latches are default to active. In comparison, present FIG. 10 illustrates in accordance with presently disclosed subject matter a representative screenshot of instances where the operator has changed the names of some of the latches that the designated “StorageCabinet” will control. Some designated names are general (for example, such as drawer one, drawer two, or office supplies) while other designated names are more specific (for example, such as gauze, bandages, tape, pens, paper). All such variations may be selected by the operator or user as desired for a particular implementation of the presently disclosed subject matter, and all such variations are intended as coming within the scope of such presently disclosed subject matter. [0097] The exemplary screenshot of present FIG. 11 illustrates an example by which an authorized operator or user has chosen certain electronic latches associated with a given hub component as being inactive (that is, not active). In the particular example illustrated, latches 6 , 7 , and 8 are flagged appropriately so as to not be active. [0098] It should also be noted with reference to present FIG. 11 that the operator or user has not selected the option “Show Active Only.” Were such feature activated, then such non-active electronic latches 6 , 7 , and 8 would not have been shown on the screenshot of present FIG. 11 . In fact, the exemplary screenshot of present FIG. 12 illustrates such removal of listings for electronic latches 6 , 7 , and 8 (based on the exemplary FIG. 11 selections) because the “Show Active Only” display option has been selected. In effect, the inactive latches have disappeared, at least from the screenshot visualizations. [0099] FIG. 13 illustrates a representative exemplary screenshot associated with a presently disclosed drop down feature referenced for example purposes as “Access Rights.” The nomenclature simply reflects that such functionality enables an authorized operator or user to assign access rights for the subject electronic lock system, as between users and the various electronic latches or locks associated with such system. [0100] The FIG. 13 exemplary illustration further represents that an operator or user has selected for viewing the access rights of a designated “sample user.” As shown, such “sample user” does not have access to the electronic lock which has per this example previously been made under the nomenclature “StorageCabinet”. Since there is no “XX/XX” designation next to “StorageCabinet,” it is signified that “sample user” does not have access to all latches controlled pursuant to the grouping “StorageCabinet.” [0101] Present FIG. 14 represents a screenshot in those instances where an operator or authorized user has pressed or actuated a designated “+” button next to “StorageCabinet.” In this representative embodiment, such selection results in visual indication of the electronic latches controlled by “StorageCabinet” as such were set up in the electronic lock editor. [0102] Present FIG. 15 representatively illustrates a screenshot whereupon an operator or authorized user has selected features designated as “drawer one” and “drawer two,” which results visually per the presently disclosed subject matter in their movement to the right side of the screen, as a reflection that “sample user” is now provided access to them. For example, note that there now is an indication in the format “(XX/XX)” next to “StorageCabinet” to indicate the number of active electronic locks selected for such user. [0103] Present FIG. 16 represents an exemplary screenshot as results from an operator or authorized user selecting the “+” button next to the “StorageCabinet” designation in the indicated green box. It may be observed per such exemplary screenshot that “drawer one” and “drawer two” indications are now shown. As a result, it may also be observed that the exemplary entry in the green box reads “StorageCabinet (2/5)”. Such nomenclature is intended to reflect that “sample user” now has access to two of the five latches controlled by “StorageCabinet”. [0104] Per the subject exemplary embodiment, it may also be observed in the middle box portion thereof that it indicates “StorageCabinet (3/5)”. Such nomenclature per the presently disclosed subject matter means that “sample user” does not have access to 3 out of 5 latches controlled by “StorageCabinet.” [0105] While the presently disclosed subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and/or additions to the presently disclosed subject matter as would be readily apparent to one of ordinary skill in the art.

Hub-based electronic lock systems and devices relate to lock or access control systems, and more particularly to electronically controlled lock systems such as may be applied to various storage enclosures or cabinets to provide secure storage of various items, equipment, materials, and/or information within the enclosures or cabinets. Certain present aspects may relate to hub and/or daisy-chained control for a plurality of electronic locks used in an electronic access control system, for inventory management using electronic locks, and/or to electronic locks with various features including display screens, access controls and tracking, and alert capabilities.

INCORPORATION BY REFERENCE This specification incorporates by reference the entire specification and drawings of U.S. patent application Ser. No. 07/816917 (PO9-90-030), filed Jan. 3, 1992, entitled "Asynchronous Co-processor Data Mover Method and Means", and assigned to the same assignee as the subject application. INTRODUCTION The invention provides automatic load balancing among plural queue processors, automatic recovery from any failing queue processor, and automatic reconfiguration for the subsystem containing the processors, while the subsystem continues to control data movement within or between electronic storage media without intervention from the operating system. BACKGROUND Prior computer systems have used plural input/output processors (IOPs) having dedicated work queues (WQs) to manage CPU requests for data movement between I/O devices and computer memory. Each IOP WQ operates with a subset of I/O devices using corresponding subchannel ID numbers. Each subchannel ID number is represented internally by a queue element (QE) in Protected System Storage and is assigned to use one or more of the IOP WQs depending on the paths associated with the device the subchannel represents. The I/O devices are accessed through various physical paths, in which some of the I/O devices may be accessed through more than one path. Each path to an I/O device is through an I/O channel and a control unit (CU), and may include I/O path switches. Each IOP and associated WQ have access to a subset of paths and as a result can only service QEs with certain paths. The IOPs manage the I/O workload requested by the CPUs in a system. Any CPU executes a start subchannel (SSCH) instruction to put a work request on an IOP WQ. Each CPU request on a WQ comprises a queue element (QE), which is a control block representing the I/O device to be started and specifying the data move information. An I/O request cannot be executed until the physical path to the requested I/O device becomes available, which includes different channel processors to control different physical paths. Thus, arequest waits if any component in its physical path is busy. If a control unit (CU) of the physical path to an I/O device is not available, the request (QE) is moved from its WQ to a Control Unit Queue (CUQ), on which the QE is parked until the CU becomes available; and then the request is moved back to its assigned WQ from which it is given to by the channel processor for its path and the channel processor controls the I/O operation. When any I/O operation is completed, the assigned IOP generates a pending I/O interruption by: moving that QE to an interruption queue (IQ) assigned to that subchannel, and sending an interruption signal to all CPUs in the system. The first CPU available for interruption looks at the Iqs and may handle one or more pending interruptions. Each QE is assigned to use one of eight IQs associated with an interruption subclass indicated in the subchannel. The IOP subsystem redistributes work among certain of its WQs, only when multiple paths have been defined in the subchannel to access a device, the path on one WQ is busy or becomes unavailable, and a path is available on another WQ. The prior IOP subsystems do not move QEs among different WQs for utilizing idle IOPs. The prior subsystems required the WQ and IOP assigned to a subchannel to handle the QE when it is a request on any WQ. A QE could not be moved to another WQ for continuing uninterrupted execution of the QE if the IOP dedicated to the assigned WQ is busy or is failing unless the I/O operation had not begun in the channel and an alternate path also exists on another IOP. The IOPs could only be reconfigured as a group (when an associated part of a computer system was reconfigured) by removing that entire group from the computer system. If alternate paths are not available, the operation is terminated. Thus, the prior art IOP WQs and their IOPs were not used for workload balancing, recovery, or reconfiguration. In prior computer systems, if only one path is provided for a subchannel, the QE associated with that subchannel ID must wait on its assigned WQ while its assigned path is busy, or wait in a Control Unit Queue (CUQ) while its I/O control unit is busy. Because different subchannels use different CUQs, the CUQs cannot serve as a central point for balancing IOP queue work. Accordingly in the prior art, a QE work request could only use the WQ permanently assigned to the subchannel. If a large number of Start Subchannel instructions (work requests) from one or more CPUs are directed to the subchannels assigned to a particular WQ, all of those work requests must use that WQ, even if one or more other WQs and their associated processors are empty and idle. Hence, the workload may become highly out-of-balance among the WQs in the prior IOP subsystems. Also in the prior art, if any IOP fails, a catastrophic condition exists, and the I/O requests on that IOPs WQ are put on a termination queue and terminated if alternate paths are not available or if the I/O operation had begun in the channel. Manual intervention may be required to enable new paths to allow the CPUs to bypass the failed WQ and its associated IOP, to reassign the subchannels to other operational WQs, and then to re-execute the CPU software from some prior point in an interrupted application program to repeat the CPU requests, in order to repeat the terminated I/O requests on newly-assigned operational WQs. SUMMARY OF THE INVENTION The primary objects of this invention are to provide workload balancing, recovery and reconfiguration internal to a subsystem performing processes offloading from the main processors of a computer system. An example of such is the ADM (Asynchronous Data Mover). This invention requires multiple processors in an offload subsystem of a computer system. The subject invention manages processes used by a plurality of processors to efficiently and continuously perform subunits of work (e.g. transferring pages of data) between a source location in an electronic memory and a destination location in the same or another electronic memory, utilizing the ADM processes and means disclosed in U.S. patent application Ser. No. 07/816917 (PO9-90-030), incorporated by reference. Application Ser. No. 07/816917 describes an ADM co-processor comprising a single processor for executing an ADM CCW program. The CPU interface to an ADM uses the S/390 start subchannel (SSCH) instruction. A special ADM subchannel is used to request an ADM operation. The CPU may perform other work while the ADM subsystem performs a CPU request to move any number of CPU requested pages from a source location in an electronic memory to a destination location in the same or in another electronic memory. The subsystem has multiple ADM processors, associated queues, a common queue, and control logic. The multiple ADM processors can simultaneously execute multiple CPU requests requested through multiple ADM subchannels. Any ADM subchannel and its associated QE can deliver an ADM request to the subsystem. Any of the ADM processors is capable of performing any received ADM subchannel request made by any CPU of a computer system (CEC). GR1 (general register 1) contains an implicit operand of the SSCH instruction which is a SCH ID (subchannel identifier) number that identifies a subchannel and its associated queue element (QE). A Queue Element is a microcoded control block which represents the Subchannel ID in internal microcode interfaces. This QE is used by a CPU as a "mail package" to carry a CPU request to a subsystem that executes the request. Another operand of the SSCH instruction locates the first ADM CCW (Channel Command Word) of an ADM program comprised of one or more ADM CCWs. Each ADM CCW specifies a list of MSBs (move specification blocks) in the memory of the computer. Each MSB specifies a source specification and a sink specification. The source specification specifies a starting address of a source location for any number (in a page count field) of contiguous pages of data(e.g. 4 KB/page) in memory. The sink specification contains the starting address of a destination location in memory for receiving the contiguous pages copied from the source location. The CPU can do other work while the ADM subsystem handles the CPU request information, and controls the transfer of a potentially vast number of data pages in or between the electronic memory(s). After all pages of a CPU request have been transferred by the ADM subsystem, it sends an I/O type of interruption to all CPUs to inform them of the completion of the CPU instruction. All CPUs receive the interruption signal and one of them will accept it under existing ES/390 Architecture rules. This invention enables an ADM subsystem to continuously handle a very large number of CPU requests utilizing automatic ADM load balancing, automatic recovery from any failing processor without interruption to the ADM processing, and automatic reconfiguration of one or more processors within an ADM subsystem. The ADM load balancing, recovery, and reconfiguration functions are each transparent to CPU processing and to operating system software. Furthermore, the invention allows a computer system to use the same CPU interface to the workload-balancing ADM subsystem as is currently used by the CPU's to interface the I/O subsystem having IOPs and WQs. The invention uses this interface compatibility characteristic to combine the ADM subsystem operations and the I/O subsystem operations into a single subsystem which performs both types of operations and may share the same set of work queues. Thus in the combined subsystem, the queues can hold both ADM and I/O requests, and each queue-offload processor (QOP) performs both ADM functions and IOP functions. However, a common queue (CQ) in a combined subsystem is used only for the ADM operations. In a combined subsystem, when a queue processor is processing an I/O request, it is operating as a conventional IOP, and when the queue processor is processing an ADM request, it is operating as a ADM processor. However, the ADM and I/O functions may be provided in separate subsystems (an ADM subsystem and an I/O subsystem) within the same computer system. But, in general, it has been found cost effective in current systems to provide a combined subsystem in which the processors and queues are shared by both the ADM and I/O requests. Also, in a combined system I/O requests are given higher processing priority than the ADM requests on each queue, because the I/O requests require very little processor time, since the I/O requests are not processed by queue-associated processors (I/O requests are processed by a different processor--a channel processor that controls the I/O data move operation). On the other hand, ADM requests are entirely controlled by the queue-associated processors, and no other processor is used. This extra use of the processors by the ADM requests causes the average ADM request to take much more processor time than any I/O request, so that more of the processor time may be consumed by ADM work--even when I/O traffic is high. However, I/O requests may be processed between ADM subunits of work. Accordingly, when ADM operations are described herein in the preferred embodiment as being processed by a QOP (a queue-associated processor), it is to be understood that the QOP need not be dedicated to only ADM operations, but the QOP also may be performing conventional I/O operations on the same queue. The invention provides novel processes for managing CPU requests for ADM service, which are managed differently from I/O requests handled by the same hardware processors. The same hardware processors execute different processes for ADM and I/O requests. Thus, the invention supports data control subsystems that may either use separate sets of queues and queue processors for ADM and I/O requests, respectively, or use the same set of queues and queue processors for both ADM and I/O requests. The ADM subchannels, unlike the I/O subchannels, do not have any path restrictions. Any ADM processor can access any path in or between the electronic storages to allow complete flexibility among all ADM queues and ADM processors to handle an ADM request from any CPU, allowing all of the electronic storage(s) to be accessible by any request through any ADM subchannel. On the other hand, I/O subchannel path controls require the I/O processors to pass the I/O request to an I/O processor that has one of the specified paths available. The request is then given to the path processors (channel processors) to complete the I/O operations. The elimination of path controls for ADM operations allows the ADM processors to complete ADM operations without requiring any path processors. Two levels of workload balancing are provided by this invention. The initial workload balancing effort has the ADM subsystem distributing the CPU requests evenly among the ADM processors. The ADM subsystem controls the assignment of a particular ADM request to a particular ADM processor. The final level of workload balancing is provided within the subsystem. The CPU requests may vary widely in their subsystem execution times, since any request can vary from a single data transfer to an extremely large number. As the workload execution proceeds within the subsystem, the actual workload variations are completely balanced by the work being continuously moved from busy ADM processors to idle ones to keep all ADM processors continuously busy as long as requests exist in the subsystem. With either separate or shared queues and processors, if a queue-associated processor is not busy when its queue receives an ADM request, the processor immediately performs the ADM request. If a queue-associated processor is busy when its queue receives an ADM request, this invention provides ADM workload balancing by having the busy processor transfer the waiting ADM request to the queue of any other processor which is not busy and that processor then immediately performs the ADM request. When all queue-associated processors are busy, and any queue receives an ADM request, the associated processor pauses between subunits of work to move the ADM request to a common queue (CQ). The CQ is serviced by all queue-associated processors when each processor completes a request and looks for a new work request to perform. The processor looks at the CQ header to find if the CQ is empty; if the CQ is not empty, that processor will immediately move a waiting ADM request from the CQ to that processor's queue, from which it may be executed. Accordingly, the invention continuously redistributes waiting ADM requests among its queues and processors to assure that all ADM requests are quickly executed by the queue-associated processors. Hence, an ADM request may have its execution completed long before its queue-associated processor would have become available for processing it, because an ADM request is immediately executed by any available processor, or it may have a minimal wait on the common queue while all processors are busy, until it is performed by the first processor to become available. This redistribution of work requests provides complete workload balancing for all ADM requests. There is almost no interference with I/O requests being handled by the same queues and processors, since an I/O request placed on a queue is handled by the queue-associated processor as soon as the current subunit of work is completed. Further, this invention provides an ADM recovery feature for each QE when it is used as an ADM request on a queue. The ADM recovery feature is provided by a checkpointing field in the QE and by a recovery process for using it. The checkpointing field retains information in the QE for locating the last page successfully moved by a failing processor while executing an ADM request. If a failure occurs to any processor while performing any page move operation, it signals its failing state and identifier to all other queue-associated processors. The first queue-associated processor to detect the failure signal becomes a recovery processor by accepting the failure signal. The recovery processor resets the failing processor, adds one to its associated queue header retry count, tests that count against the maximum allowable retry count, and if less, establishes conditions allowing the failed processor to retry the operation from its last successfully completed subunit of work. Otherwise, the failing processor is stopped, removed from the operational subsystem, and its work redistributed to other processors through the subsystem workload balancing process. In trying to recover, the recovering processor accesses the checkpointing field in the QE being handled by the failing processor and uses data in the checkpointing field to reestablish execution of the incomplete ADM request from its last successfully completed subunit of work until the request is successfully completed. If the failing processor cannot be recovered, the QE element is placed on the associated queue of the recovery processor which may subsequently complete the work request, or put it on the CQ to be completed by the first processor that finishes an ongoing request. In any case, the operation is begun from the checkpointed state. This differs from I/O handling since any ADM QE on any associated queue, or in execution, can be performed to successful completion by any processor in the subsystem. When a processor is removed by the recovery process, the QEs are searched to determine and change, where necessary, the queue assignment for new requests (made by a CPU) to the queues remaining after the recovery. The recovery feature enables full recovery of the ADM operations in a manner transparent to the rest of computer system outside of the subsystem, and without interruption to the work being done by the subsystem. A slight slowdown in the subsystem operations may occur during high request loads, since the subsystem may then be operating with fewer processors. This invention also provides an ADM dynamic reconfiguration feature available for use at any time to allow any processor to be removed, or a new processor to be added, to the subsystem, as long as there is at least one operational processor remaining in the subsystem. Reconfiguration involves a re-assignment of QEs to the queues and their processors remaining after the reconfiguration. This invention marks the header of each queue being removed (for a processor being removed) in a reconfiguration operation by setting an enabled field to a disabled state. Any pending requests (QEs) on the disabled queue are moved to other queues remaining operational (including the common queue). The QE move operation may be done by a processor assigned in a reconfiguration command as the reconfiguration processor for handling that command. Also, this invention marks the header of each queue being added (for a processor being added) in a reconfiguration operation by setting the enabled field to an enabled state. The reconfiguration process requires a queue-associated processor to search through all QEs to determine and change, where necessary, the queue assignment(s) to the queues remaining after the reconfiguration. In the case of a processor being logically removed from the subsystem (the deleted processor), its queue is also removed and the reconfiguration processor re-assigns QEs of the deleted processor to remaining processor queues. In the case of an added processor queue, the subsystem may re-assign some of the QEs from the prior existing queues to each new processor queue. The workload balancing feature that increments associated Q ID and the feature that assigns work to idle processors will assign pending QEs to the added processor. In this manner, ADM requests are redistributed to operational processor queues and to the common queue without any involvement being required by other parts of the computer system, or by any software in the computer system (including no required involvement by a software operating system), in performing the work load balancing, recovery and reconfiguration operations of this invention. DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a computer system structure containing an embodiment of the invention. FIG. 2 is a multiple queue subsystem representing a preferred embodiment of the invention within a computer system. FIG. 3 represents important fields in a queue element which is a microcoded control block associated with a subchannel. FIG. 4A shows fields used by the embodiment in a header of each processor queue. FIG. 4B shows fields used by the embodiment in a header of a common queue (CQ) . FIG. 5 is a flow chart of a CPU request process that chains a subchannel on an assigned processor queue as a requesting queue element. FIG. 6 is a flow chart of a workload balancing process used for each ADM queue element (a subchannel) on any processor queue or on the common queue. FIG. 7 is a flow chart of a "do execute" subprocess in the workload balancing process in FIG. 6. FIG. 7A is a flow chart of a "do checkqueue" subprocess in the workload balancing process in FIG. 7. FIG. 8 is a flow chart of a "do getwork" subprocess in the workload balancing process in FIG. 6. FIG. 9 is a flow chart of a reconfiguration process used by the ADM subsystem. FIG. 10 is a flow chart of a recovery process used by the ADM subsystem. FIG. 11 shows a bus connecting among queue processors in the subsystem. The bus is used for signalling in the workload process, in the recovery process, and in the reconfiguration process of the preferred embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS CPU Operations--FIG. 1: FIG. 1 shows a computer system containing a CPU offload subsystem 20, which offloads asynchronous data-move management operations from a plurality of CPUs 1 through N to a subsystem 20, which moves pages of data within and between electronic memories 21 and 23, and an I/O subsystem 22 that includes I/O channel paths, I/O control units and I/O devices. The memory 21 is a system main memory 21 (sometimes called MS), and memory 23 is an expanded storage (sometimes called ES). Each CPU uses the S/390 start subchannel (SSCH) instruction to put a queue element (QE) assigned to the subchannel on a subsystem queue. The SSCH instruction operates in the manner disclosed in IBM publication entitled "Enterprise System Architecture/390 Principles of Operation" having form no. SA22-7201 for I/O requests, and for ADM requests operates in the manner disclosed and claimed in patent application Ser. No. 07/816917 (PO9-90-030), previously cited. For both I/O and ADM requests, the CPU execution of the SSCH instruction accesses an ORB (Operation Request Block) specified by second operand. GR1 specifies the subchannel ID number. The SSCH instruction invokes microcode in its CPU that accesses the queue in subsystem 20 assigned to each identified subchannel, and chains subchannel-associated QE into the queue assigned to the QE using the priorities disclosed herein in the respective queue. Fields in the header of the queue are set to the address of the current bottom (last) QE in its queue, and the address of the current top (first) QE in the queue. Each QE in any queue represents a "unit of work" to subsystem 20, which is a request to the QOP associated with the queue containing the QE to transfer an indicated number of pages between source and destination addresses identified in the QE. The execution of the SSCH instruction is completed after the accessed QE is chained as the last QE in the identified queue, nd after the CPU sends a signal to the associated QOP that a new queue element (QE) has been chained into its queue. If the QOP is then not busy, it will immediately access the first QE on its associated queue (in the preferred embodiment) and begin executing it. If the new element is the only element on its queue, the signalled QOP accesses the new QE to obtain its next unit of work. If the QOP is busy, it will discover the new request by testing after completing each subunit of work. Subsystem Operations--FIGS. 1 & 2: Subsystem 20 in FIG. 1 includes a set of queue-offload processors (QOPs), QOP associated queues (hereafter called "QOP queues), and a common queue (CQ). The CPUs put requests on the QOP queues, and the QOPs take the requests off their respective QOP queues and execute them or move them to other queues. Each CPU request is put on a queue in the form of a queue element (called a QE) which is chained (addressed) into a queue. An ADM or I/O request from a CPU may chain a subchannel into a queue as a queue element (QE). Thus, the QOPs are offload subsystem processors which perform asynchronous data move processes in response to CPU requests put into the queues. A CPU request may be an I/O request, or an ADM request for moving N number of pages within or between electronic memories 21 and 22. That is, each QOP performs one or more processes required by each received CPU request, whether they are I/O processes or ADM processes. The ADM processes performed by the QOPs include ADM execution control, load balancing, recovery and reconfiguration. Subsystem 20 is shown in more detail in FIG. 2. Each queue element has a field set by initialization to indicate whether the requested subchannel operation represents an I/O or ADM request. The CPUs put the I/O and ADM requests at the bottom of each QOP queue. Each QOP finds its next work unit by accessing the QE located by the address in the "Top Q PTR" field in the header of its associated queue. A unit of work is represented by either an I/O or ADM QE chained in a queue. A queue is empty if its "Top Q PTR" field contains the address of its header. If not empty, the processor accesses the QE at the top of its queue, and changes content of the "Top Q PTR" field to the address the next QE in the queue. If there is no next element, the processor writes in the header address. The current work unit is unchained from any queue when it is to be performed. When the QOP completes an I/O request or a unit of ADM work (in other words completes an entire ADM request), the QOP looks at the CQ header to see if the CQ is empty. If the CQ is not empty, the QOP moves the top QE in the CQ to the top of the QOP's queue and returns to queue processing. If a QE is moved, or if no QE is on the CQ, the QOP looks at its queue header to see if it is empty. If the queue is not empty, the QOP executes the QE at the top of its queue. All new CPU requests are put at the bottom of the queue. This manner of putting and taking QEs on and from each queue maintains the priority of execution of the QEs in any queue, attempting to service them as close to arrival order as possible. The I/O processes performed by the QOPs are the conventional IOP (I/O processor) processes performed by conventional IOPs found in the IBM mainframes, such as in the IBM ES/9000 M900 system, and in prior S/3090 systems. The ADM processes performed by the QOPs are the primary subjects of this invention. The common queue (CQ) in subsystem 20 is used only for ADM processes and is usable by all QOPs. A QOP checks for pending ADM or I/O requests after it completes a work unit, and after it completes each work subunit while performing a work unit. It checks its queue by looking at its header to see if any new request(s) were put on its queue. If it has any new request, it checks if it is an I/O type or an ADM type. If an I/O type, it handles the CPU request by transferring it to a channel processor and returns to ADM work on the subsystem queues. If the new request is an ADM type, the QOP tries to pass the new request to an idle processor, if it can find one. It does this by checking the QOP busy pointers in the CQ header to determine if there is an idle QOP. Then, the checking QOP transfers the new ADM request (QE) from the top of its queue to the bottom of that idle QOP's queue, and signals the idle QOP. If the checking QOP does not find any idle queue, it enqueues its new ADM request on the CQ, and returns to its processing. The checking QOP then continues processing whatever it was processing when it paused. When any QOP becomes idle, it then checks the CQ header for an empty state. If the CQ is not empty, the QOP takes the top CQ request and moves it to the top of its queue where it will be taken as its next work unit. If the CQ is empty, it next checks its own queue for work. If there is none, the QOP goes into wait state. QOP operations: Normally, the QOP dequeues the top subchannel QE in its associated queue and executes the QE to perform a unit of work. The QE execution transfers a specified number of subunits of data between the two locations specified in the queue element, which may be addresses in the same electronic storage medium or in two different electronic storage media in the system. These operations follow the teachings in application Ser. No. 07/816917 (PO9-90-018). For example, a "unit of work" may be the transfer of 10,000 pages of data between MS and ES, or the transfer of 38 pages of data between two locations in MS. Each page transfer is an example of a "subunit of work". A unit of work is equal to a subunit of work only when the unit of work specifies a single subunit transfer. A QOP pauses after it completes each subunit of work. During the pause, the QOP looks at its top queue pointer in its queue header to see if it indicates any QE is waiting in its queue. If a waiting ADM QE is indicated, the paused QOP momentarily switches from its subunit transfer operations to find any non-busy QOP in the subsystem. If a non-busy QOP is found, the paused QOP moves the waiting QE to the non-busy QOP queue, and signals the non-busy QOP that it has a QE on its associated queue. If the paused QOP finds all QOPs are busy, it moves the waiting QE to the bottom of the common queue (CQ). In normal processing if no work exists in the CQ or associated queue, the QOP remains idle until it is signalled either that an I/O or ADM QE has been put on its queue. The load-balancing redistribution of ADM Qes among QOP queues and the common queue keeps all QOPs continuously busy as long as the CPUs are putting Qes on any queue in the subsystem. This manner of operation obtains the maximum processing speed for all work provided to the subsystem, when compared to a non-load balanced queued subsystem handling ADM requests. Queue Element (QE)--FIG. 3: FIG. 3 represents a QE which is a control block stored in protected electronic storage associated with a subchannel. The QE used by this invention may be a control block associated with a particular subchannel (pointing to a subchannel), or the QE may be the subchannel itself, which is a control block having pointer fields for being chained into various types of queues. Each QE contains the following fields in this embodiment: "lock", "subchannel ID", "type", "busy ID" (identifier), "Current Q ID" (queue identifier), "Current Q chain PTR", "assigned Q ID", "checkpt Subunit Data", "Channel Program Address", and "status". The "lock" field is set on to warn other QOPs and CPUs when the QE is being accessed to change one or more of its fields. The "subchannel ID" field contains the ID number of the associated subchannel. The "type" field indicates whether the QE is an I/O QE or an ADM QE. If neither, it is not a request that is processed by the QOP subsystem. The "busy ID" field identifies the QOP which is currently accessing this QE. The "current Q ID" field identifies the current queue containing the QE. The "current Q PTR" field addresses the queue header of the queue containing this QE; this field is cleared while this QE is not on any queue. The "Current Q chain PTR" field addresses the next QE in the queue which is to be executed. This field has a special value if this QE is the last QE in the queue. This field is cleared while this subchannel is not on any queue. The "assigned Q ID" field identifies the QOP queue to which a CPU assigns this QE. The "Checkpoint Subunit Data" field contains several subfields, including: 1. a valid bit (V) subfield which is set on when all subfields are valid in the "Checkpoint Subunit Data", 2. a CCW (channel control word) subfield containing an address to the current ADM CCW in the current ADM program, 3. an MSB subfield containing an address to a current move specification block (MSB) that specifies subunit move parameters for the current ADM CCW, and 4. a subunits moved subfield indicating the current number of successfully moved subunits for the current MSB. The ADM CCW, and MSB (move specification block) operations are described and claimed in the prior cited application Ser. No. 07/816917. The "Channel Program Address" field in the QE contains the address of the ADM channel program obtained from the ORB of the invoking SSCH instruction. For an I/O request, this field contains the address of the required I/O channel program. For an ADM request, this field contains the address of the required ADM program. The "ADM Program" is a list of ADM CCWs in memory. The "status" field contains status information for the ADM work unit to be reported to the requesting CPU when the work unit is completed and placed on the interruption queue. QOP Queue Header--FIG. 4A: FIG. 4A shows important fields used in each QOP associated queue header. Each queue has a header for anchoring the queue at an address known to all CPUs and QOPs, so that they can access the header whenever they need to access its associated queue. Each QOP queue header contains the following fields which are used in this embodiment: Lock field, enable field, retry count, top Q PTR field and bottom Q PTR field. The lock field is set whenever a field in this header is to be changed. The enable field may be a single bit field which is set on when the associated queue is enabled, and is set off when the associated queue is disabled. The retry count field contains the current number of errors that the associate QOP has encountered in a predefined window in time. The top Q PTR field contains the address of the QE at the top of the associated QOP queue (which is the QE currently having the highest priority in the queue) and is the next QE to be executed in this queue. The top Q PTR field contains its header address when its queue is empty (contains no QE). The bottom Q PTR field contains the address of the QE which is at the bottom of the queue, which has the lowest priority on the queue, and is the last QE to be executed of the Qes currently on the queue. The bottom Q PTR field is accessed for putting a next QE onto the queue. Common Queue Header--FIG. 4B: FIG. 4B shows fields in a header of the common queue (CQ) used by all QOPs in the subsystem. Only ADM QEs are put on the CQ. The CQ header (CQH) contains the following fields used in this embodiment: Lock field, QOPo busy PTR through QOPy busy PTR, top Q PTR and bottom Q PTR. The lock field is set whenever the CQH is to be changed. Each of the QOPo-QOPy busy PTRs fields respectively contains the address of the ADM QE currently being executed by (and last removed by) the respective QOP. A QE address in the field indicates a busy state for the respective QOP. The content of the respective QOP busy PTR field is cleared (empty) if no QE is being processed by the respective QOP. The top Q PTR field addresses the QE at the top of the CQ (which is the QE to be next executed in the queue), or it addresses the CQH when the CQ is empty. The bottom Q PTR addresses the QE at the bottom of the queue, which is the last QE to be executed of the QEs currently on the CQ; and it is the field accessed for putting a next QE onto the CQ. CPU Request for Subsystem Service--FIG. 5: FIG. 5 shows a process used by any CPU to put a unit of work on any of the QOP queues. In this process, a CPU chains a QE into the bottom of a QOP queue determined by the queue assignment in the QE's "current Q ID" field. The CPU request may request an I/O work unit or an ADM work unit. The first step 50 in FIG. 5 is the accessing by any CPU of an S/390 "start subchannel" (SSCH) instruction to make a request for a unit of work to the QOP subsystem. The first operand of the SSCH instruction specifies the subchannel ID number in general register 1 (GR1). The process in FIG. 5 is similar to the conventional process used in IBM mainframes to start I/O devices, for which a CPU issues an SSCH instruction which chains a specified subchannel as a queue element (QE) into an IOP queue specified in the QE, and signals an IOP (input/output processor) associated with the queue to process the new queue element. Then step 51 executes conventional SSCH instruction, including exception tests during the execution in the manner done in the prior art. The QE is tested by the microcode for validity and for being operational early in the execution process. If these tests indicate the QE is not valid or operational, the exception path is taken to the process end at step 52. If these tests indicate the QE is valid and operational, the process continues to step 53, in which the CPU chains the QE at the bottom of the queue specified in the "assigned Q ID" field in the QE. Then in step 54, CPU microcode provides a signal to the QOP associated with the assigned queue that a new QE has been put on its queue. This signal enables the QOP to immediately process this QE if the QOP is not busy doing other work. The subchannel operand of this SSCH instruction is now represented by a QE on the assigned QOP queue. The CPU execution of the SSCH instruction ends by setting a zero condition code (CC=0) to indicate to the CPU program that this instruction has successfully completed. The CPU program is now free to execute its next instruction which is not required to have any relationship to the SSCH instruction. Queue Element Processing--FIG. 6: The process in FIG. 6 is started for each QOP when it first receives a QE signal from a CPU indicating a work unit has been put on its queue. A QE signal sets on a bistable latch of the QOP that it has received a QE signal, (the latch remains in its on state until the QOP finds its queue empty, which is when the QOP sets the latch off). Step 61A is initially entered to access the queue header and test for the queue empty state by testing if the "top Q PTR" field contains the address of the header. If empty, step 61B resets the QE signal received latch to indicate a no-QE-signal-received state. The "Top Q PTR" field in the header of each queue contains the address of the QE currently at the top of the associated queue. If the content of the "Top Q PTR" field equals the address of its queue header, then the respective queue is empty (has no QE). If step 61A finds that the queue is not empty, its no path is taken to step 61, which removes the QE subchannel addressed by the "top Q PTR" field. When a QE subchannel is removed from a queue, its "Current Q Chain PTR" field (pointing to the next subchannel in the queue) is written into the "Top Q PTR" field in the queue header to overlay its prior content. The new "Top Q PTR" field points to any next subchannel in the queue which is now at the top of the queue. If there is no next subchannel in the queue, this field points to the queue header. Then, step 62 determines that the removed QE subchannel is an ADM QE or an I/O QE. If it is not an ADM QE, step 63 is entered to handle an I/O QE, and the conventional I/O process is performed. If step 62 determines the removed QE is an ADM QE, the yes path is taken to step 65 to set the QOP's Busy PTR field in CQH, and to set the Busy ID field in this QE subchannel to the identifier of this QOP. The QOP is now busy processing an ADM subchannel. Then, step 66 is executed, which is a branch to the "Do EXECUTE" process in FIG. 7, which executes the work unit a subunit at a time. After the execution of the unit of work is completed, box 67 is entered. Box 67 contains a set of housekeeping steps done at the completion of the work unit. These housekeeping steps include clearing (setting off) the "QOP's Busy PTR" field in the CQH. Also, the "Checkpoint Subunit Data" field in the subchannel is cleared and/or its V bit is set off, since no subunit checkpointing is needed after the unit of work has been completed. Box 67 also clears the QOP Busy ID in the subchannel. Also, the assigned Q ID is incremented to the next available QOP which, on the next SSCH, will cause the QE to be placed on a different QOP queue. Box 67 also has the subsystem generate and send an ADM interruption signal (which is presented to the CPUs as an I/O type of interruption indicating an ADM subchannel) to indicate to the CPUs that a requested ADM data move operation has been completed. Then, box 67 performs the step "Do Getwork" process shown in FIG. 8, which has the current QOP look at the common queue for its next unit of work, if the CQ has any waiting QE subchannel. Then the process in FIG. 6 is ended. Execute Process--FIG. 7: When the "Do Execute" step 66 is reached in FIG. 6, a branch is taken to the execute process in FIG. 7, which controls the execution of the current ADM unit of work (e.g. the movement of its pages of data) represented by the currently removed QE. The execute process also stores checkpointing data in that subchannel's "Checkpt Subunit Data" field and sets it valid for each successfully completed subunit of work. The "execute" process begins by entering step 70, which checks the state of the validity (V) bit in the "Checkpt Subunit Data". If the valid bit is set off, it indicates the current QE is a new request having no prior checkpointing data in its Checkpt Subunit Data, and the no path to step 72 is taken to initialize the content of that Data by setting it to represent the first subunit of work. If step 71 finds the valid bit is on, the next subunit to be done is not the first, and the yes path to step 73 is taken. Step 73 then performs to complete the next subunit of work (e.g. moving the next page required by the current QE request as defined in checkpt data). Then step 74 performs the checkpointing for that subunit after its execution is completed. This is done by storing in the "checkpt subunit data": 1) the total number of subunits of work performed thus far for the current MSB including the subunit completed by step 73, 2) the address of the MSB specifying the currently completed subunit, 3) the address of the ADM CCW specifying this MSB, and 4) the valid bit is set to its on state. The next step 75 tests if there are more subunits of work to be done in the current unit of work. If step 75 detects the last completed subunit is not the last subunit to be done for the current QE request, then more subunits remain to be done; and the yes path is taken back to step 75A to check for more QEs executing checkqueue process (FIG. 7A). Once the QOP queue has been checked and any QEs processed then the processing returns to step 73 to execute the next subunit of work for the current QE followed by step 74 storing its checkpointing data when it is successfully completed. The iteration back to step 73 involves having the ADM program fetch any next MSBs and any next ADM CCWs in the ADM program associated with the current QE, until all of its MSBs are executed for that QE subchannel (representing one CPU request to the ADM). When step 75 detects that the last subunit is completed for the work unit, the no path to step 76 is taken. Step 76 is entered to set the status in the currently executed ADM QE. This Status field of the current ADM QE is set to indicate the successful completion. Step 77 is entered to return to the process in FIG. 6 that called the "Do Execute" process in FIG. 7. The process in FIG. 6 then enters its box 67. CheckQueue Process--FIG. 7A: The "checkqueue" process in FIG. 7A is entered at point 78A from the "yes" path from step 75 in FIG. 7 to check for other work pending. Step 78K tests for a recovery signal pending and branches to step 78M to process the recovery action if this processor becomes the recovery processor. If no recovery signal is pending, the "no" branch is taken to step 78L, which tests for a pending reconfiguration signal. In step 78L, if a pending reconfiguration signal is active, and this processor becomes the reconfiguration processor, the "yes" branch is taken to step 78N to process the reconfiguration request. If no reconfiguration signal is active, the "no" branch is taken to step 78B. If either signal is taken by the processor, the signal is tested and set off as one operation so that no other processor will react to the signal. In step 78M, the recovery process (FIG. 10) is called and then the process returns to step 78B in FIG. 7A when complete. In step 78N, the reconfiguration process (FIG. 9) is called and then that process returns to step 78B in FIG. 7A when complete. The checkqueue process then tests whether the queue of this QOP is empty in step 78B. If it is empty, the "yes" path is taken to step 78H to end the checkqueue process. If it is not empty, the "no" path is taken to step 78C to dequeue (remove) the top QE from that queue. Then step 78D tests if the removed QE is an ADM QE. If not, it is an I/O QE, and the no path is taken to step 78P which performs the conventional I/O process. If this is an ADM QE, the "yes" path is taken to step 78E to look for another QOP which can perform the dequeued QE request. It is to be remembered that the current QOP is presently busy doing a unit of work which has not been completed when the QOP paused at the end of the last subunit to do the "Checkqueue" process within the execution of the unit of work. Accordingly, the current QOP cannot execute this dequeued QE at this time. If step 78E finds another QOP idle (because it is not doing any ADM work) and queue enabled, the "yes" path is taken to step 78F to enqueue this removed QE onto the QOP queue of that idle QOP. Then, step 78G has the current QOP send a QE signal to the idle QOP to indicate to the idle QOP that a QE has been put on its queue. A return is then taken back to the execute process in FIG. 7 where step 73 is entered. If step 78E did not find any idle and enabled QOP, then step 78J is entered which enqueues that QE onto the top of the CQ if it has valid checkpoint subunit data or on the bottom of the CQ if it does not have valid checkpoint data, and a return is then taken back to the execute process in FIG. 7 where step 73 is entered. Getwork from Common Queue Process--FIG. 8: When the "Do Getwork" step is reached in FIG. 6, a branch is taken to enter the "getwork" process in FIG. 8 at its step 80. The "getwork" process accesses the common queue header (CQH) and examines its "Top Q PTR" field to determine if the CQ is empty or not. If the CQ is empty (contains no QE), the content of the "Top Q PTR" field contains the address of the CQ header. If no valid address is contained therein, a return is taken in step 83 to step 67 in FIG. 6. But if a valid address is contained therein, step 82 is performed by using that address to dequeue the top QE from the CQ to get the next QE in the CQ, then enqueue that QE on top of the QOP queue. Step 83 is then performed to enter the process in FIG. 6 at its step 67. Reconfiguration Process--FIG. 9: An ADM subsystem may be reconfigured by a human system operator entering commands to the computer system to remove or add one or more QOPs, each having an associated queue. This may happen, for example, when a multiprocessing system is to be subdivided into two or more independent images or systems. Each QOP must remain part of the reconfigured system portion in which the QOP physically resides. Ongoing and already-queued requests must be handled by that part of the system on which the operating system which initiated them will reside after the reconfiguration. Requests which were in progress on QOP's leaving the system portion on which the currently executing operating system will continue executing must be reassigned to QOP's remaining in that portion. The CQ also remains as part of the remaining portion. If reconfiguration involves the adding of elements previously removed by reconfiguration, the additional QOP's become part of the operational QOP subsystem. The reconfiguration QOP will dequeue a QE from the CQ if available and signal the added QOP. If no QE's are available on CQ, the add QOP waits for a signal. Each reconfiguration command is provided to the ADM subsystem in the computer system either from a CPU, or from a service processor. The reconfiguration commands are herein called QOP vary off-line and vary-online commands, which may be entered by the operator to remove or add one or more QOPs in a subsystem, respectively. In this embodiment, a QOP vary on-line command adds one QOP to a QOP subsystem, and a QOP vary off-line command removes one QOP from a QOP subsystem. FIG. 11 represents a QE signalling, recovery and reconfiguration bus 110 which is connected to all QOPs in the subsystem. Bus 110 is also connected to a reconfiguration signalling means 111, through which an operator can provide reconfiguration command signals to all QOPs. The QOP vary off-line command and the QOP vary on-line command are dynamic commands, which may be issued and executed while the subsystem is in use, and the subsystem may be in any state of operation when a command is received by the QOPs. That is, a vary-offline command to remove a QOP may be executed while that QOP is executing a QE without any disruption of the QOP subsystem being apparent to the rest of the computer system. And that command will not adversely affect the results of the execution of any ADM QOP work unit. If a vary-offline command occurs to any QOP to delete it from the subsystem while it is executing a work unit, the "checkpointing subunit data" field in the QE is used to properly control the switching of the execution of that QE from the deleted QOP to one that will remain an operational QOP for the same operating system after execution of the reconfiguration command. When one QOP is added or deleted per reconfiguration command (as is done in this embodiment), an operator may use a sequence of commands in order to add or/and delete as many QOPs as desired. However, it is apparent that a specified number of QOPs may be removed or added by a single reconfiguration command by iterating the reconfiguration process for one QOP a pecified number of times to handle a multi QOP command. The command information signalled on bus 110 in FIG. 11 specifies: the add or delete operation to be performed, and an identifier for the QOP being added or deleted. The first QOP that finds a reconfiguration signal performs the reconfiguration process. It may be any of the QOP(s) that are to remain operational after the reconfiguration process is completed. The command information is detected from bus 110 and stored in the identified QOP being deleted (called the add QOP or delete QOP) and in the identified reconfiguration QOP. Thus, the QOP vary-offline command identifies and designates the QOP being removed as the "Delete QOP", and also involves a QOP remaining in the subsystem as the "reconfiguration QOP". Any QEs in the queue associated with the Delete QOP are moved from the queue associated with the Delete QOP to the queue associated with the reconfiguration QOP. If the Delete QOP queue is empty, no QEs are moved; but if it is not empty, the QEs of the Delete QOP are moved to the reconfiguration QOP queue. The QE move process is executed by the reconfiguration QOP in the preferred embodiment. The QOP vary on-line process adds a QOP to a subsystem. The added QOP is physically added to the subsystem before the process in FIG. 9 is executed. The add command identifies and designates the QOP being added, and a reconfiguration QOP executes the add process. The process sets up a header for a new queue associated with the added QOP, which has its ID written in the header by the reconfiguration QOP. The vary-on command does move a QE from the CQ to the added QOP queue if any QE(s) are pending in the CQ. Once the added QOP queue is enabled, FIG. 6, step 67 "increment assigned QID" will begin to automatically assign work to the added QOP queue. FIG. 9 describes the processing done by the QOP accepting the reconfiguration signal. Step 90 is entered after a QOP vary command is received for adding or deleting one QOP. Then, step 91 is performed to determine from the command operation signal if it is a vary-online command or a vary-offline command. The delete path to step 92 is taken for a vary-offline command. Step 92 sets the enable field in the Delete QOP queue header to the disable state. Then step 92 moves all subchannels on the Delete QOP queue to the reconfiguration QOP queue and signals the reconfiguration QOP in case it will return to an idle state. And finally step 92 stops the Delete QOP. Then step 93 accesses the "QOP Busy PTR" field of the Delete QOP in the CQ, and reads from that field the address of a "checkpointed subchannel", if any, which was in execution by the Delete QOP when it was stopped by step 92. The checkpointed QE had been dequeued from the Delete QOP queue to start its execution, and thus is not part of the Delete QOP queue. Therefore, in step 93 the reconfiguration QOP enqueues the checkpointed QE on the reconfiguration-QOP queue and signals the reconfiguration QOP so that the QE will have its execution continued later either by the reconfiguration-QOP or by another QOP on another queue to which the QE is later moved. Then, the reconfiguration-QOP clears the "QOP Busy PTR" field of the Delete QOP in the CQ, resets the QE Busy ID in the QE to remove any association with the Delete QOP, and enters step 97, which if step 90 was entered from the idle state, will return to the idle state. If not, step 91 was entered from FIG. 7A step 78N, and step 97 will return to FIG. 7A step 78B. In the checkpointed QE, the valid bit in the state of the "Checkpt Subunit Data" determines if reconfiguration occurred during the execution of the QE, which is indicated if the V bit indicates valid checkpointing information exists in that QE. Then, any operational QOP can later use this checkpointing data to complete the QE execution by continuing from the last successful subunit indicated in the checkpointing data until the QE execution is successfully completed. The Delete QOP may then have its power shut off, because its operation is no longer needed in the subsystem. It may then be replaced in the QOP subsystem, or maintenance may then be performed on it while it is either in or out of the subsyste or it may be a part of a different QOP subsystem associated with other portions of the system configured out of the original system. QEs assigned to the associated queue of the delete QOP are reassigned to the queues associated with QOPs remaining in the subsystem to route future work to them. And finally, step 93 enters step 97 so that the reconfiguration processor can continue its normal operations by returning to its prior state. The reconfiguration process is then ended for the deleted QOP. Any number of QOPs can be reconfigured off-line by successive vary-offline commands, as long as one QOP is left operational in the system. The add path from step 94 is taken for a QOP vary-online command for adding a QOP to the subsystem. The added QOP was physically added into the subsystem before the process in FIG. 9 is executed. Step 94 sets up a new QOP header for a new queue associated with the new QOP being added. Then, step 94 starts the added QOP by turning on power if necessary and enabling its QOP queue. The new QOP is put into an idle state, in which the QOP is waiting either for a signal from a CPU that a QE has been put on its associated queue, or for a signal from another QOP that has moved a QE onto its associated queue. In step 95, if the CQ contains QE's enter step 96. If the CQ is empty enter step 97. Step 96 will dequeue the top QE from the CQ and enqueue the QE on the added QOP queue and signal added QOP. In step 97, if entered from step 78N the return will resume processing at step 78B. If entered due to reconfiguration signal received when it was in idle state, the return will return to IDLE state waiting for another signal. The subsystem will automatically assign subchannels which will henceforth cause new QEs to be enqueued on the new queue now being added. Any number of QOPs can be reconfigured on-line by successive vary-online commands. An alternative way to vary off-line any QOP is by simulating a permanently failing condition for the QOP, and then using the recovery process described in the next section herein to remove the simulated failing QOP. Recovery Process--FIG. 10: The recovery process in FIG. 10 depends on each QOP internally having error detection capabilities equivalent to that found in state of the art processors currently in commercial use. The detection of an error condition in a QOP causes the QOP with the error condition to send a recovery signal to the other QOPs on bus 110 in FIG. 11. Sending this recovery signal initiates the recovery process in FIG. 10 at step 100. For example, an error condition may be detected if temporary errors exceed a predetermined threshold count, or if any permanent error is detected in a QOP. The first QOP in a state for receiving a recovery request signal on bus 110 detects the signal and responds with an acceptance signal on the bus 110 which indicates the accepting QOP will act as a "recovery QOP". The acceptance signal sent by the recovery QOP is recognized by the other QOPs as indicating they can continue with their normal processing operations having nothing to do with these recovery operations. In step 101, the recovery QOP resets the failing QOP (called the error QOP) and may increment a retry count in the QOP queue header of the error QOP to indicate the number of times an error has occurred to the error QOP. Step 102 is then entered by the recovery QOP to detect if the reset of the error QOP has failed or if the retry count (in the QOP queue header) has exceeded the predetermined maximum value (N). (The subsystem may use any method, including methods well-known in the prior art, to determine if the error QOP has a temporary or a permanent error condition, which is to repeat the process in which an error condition occurred for N retries. A temporary error is considered a permanent error condition if the error condition remains after its Nth retry of the process or if the reset fails. N is an empirical number set by experience in processor operation, (for example may be 20) and is reset periodically.) This retry operation is initiated by microcode in the recovery-QOP which re-starts the QE process in the error-QOP as shown in steps 103 to 104. After step 102, the recovery-QOP performs step 103 by accessing the header of the common queue and reading the "QOP Busy PTR" field of the error-QOP, which contains the address of the QE it was processing when the error condition occurred. Then step 103 sets the "busy ID" field in the QE to the error-QOP's identifier to indicate the QE is currently busy with the error-QOP. Then the recovery-QOP enqueues the QE into the error-QOP queue by setting the "Bottom Q PTR" field in the error-QOP queue header to the address of the QE, which chains that QE to the top of the error QOP queue. Then, the error-QOP is signaled so its processing enters step 61A in FIG. 6 to cause it to continue its normal processing. In step 104, the recovery-QOP returns to normal operation, either step 78B in FIG. 7A or to the idle state to wait for another signal. If a permanent error condition is determined in step 102, step 105 is entered by the recovery QOP, and it performs the remaining steps 105, 106 and 104 in the recovery process. Then step 105 is entered from step 102, and the recovery-QOP accesses the header of the error-QOP queue and sets its enable field to indicate the disabled state. The recovery-QOP then moves any QEs on the queue of the error-QOP to the recovery-QOP queue, and stops operation of the error-QOP so that maintenance can be performed on it. QEs assigned to the associated queue of the error-QOP are reassigned to queues associated with operational QOPs in the subsystem. Then in step 106, the recovery-QOP accesses the "QOP Busy PTR" field of the error-QOP in the common queue header to obtain the address of the QE that was being executed on the error-QOP at the time that it failed. This QE is enqueued at the top of the recovery QOP queue and the recovery QOP is signalled after the QE's "busy ID" field is reset, since it is not now being executed. Finally, step 104 is entered and the recovery-QOP, if it was idle when the recovery signal was received, returns to the idle state. Otherwise, the recovery was called from step 78M in FIG. 7A so it returns to step 78B in FIG. 7A to continue processing its active QE. The checkpoint information in the QE enqueued by step 106 is used by the recovery process. This QE will be executed in due course by either the recovery-QOP or by another QOP if the QE is moved to another QOP queue. The content of the "Checkpt Subunit Data" field in the QE enables its execution to be re-started at its next subunit after its last successfully completed subunit operation and to continue until the execution of the QE work unit is completed. Many variations and modifications are shown which do not depart from the scope and spirit of the invention and will now become apparent to those of skill in the art. Thus, it should be understood that the above described embodiments have been provided by way of example rather than as a limitation.

Provides load balancing, recovery and reconfiguration control for a data move subsystem comprised of a plurality of interconnected and cooperating data move processors (DMPs). Each DMP processor has an associated queue for receiving queue elements (QEs) from central processing units of a data processing system which specify data move requirements of the data processing system. QEs can be transferred between queues of other DMPs or a common queue to achieve load balancing, recovery and reconfiguration control.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an image recording apparatus, more particularly to an image recording apparatus that supplies adjustable driving current to a driven element by which an image is recorded, and to a method of recording an image using an apparatus of this type. [0003] 2. Description of the Related Art [0004] Referring to FIG. 1, in an electrophotographic apparatus, a photosensitive member such as a photosensitive drum 51 is charged by a charging unit (CH) 35 , then selectively illuminated by one or more light-emitting elements in, for example, a light-emitting-diode (LED) head 3 according to information to be printed, forming an electrostatic latent image on the photosensitive drum 51 . The electrostatic latent image is developed by selective application of toner in a developer 52 to form a toner image, which is transferred to recording medium such as recording paper 53 by a transfer unit (T) 36 , then fused to the paper. The elements shown in FIG. 1 form a type of printing mechanism 60 . [0005] One type of electrophotographic apparatus is an electrophotographic printer. A more detailed description of an electrophotographic printer will be given below with reference to FIG. 2, which is a block diagram of the control circuits of a conventional electrophotographic printer, and FIGS. 3 and 4, which are timing diagrams illustrating the operation of the conventional electrophotographic printer. [0006] The printing control unit 1 in FIG. 2 is a computing device comprising a microprocessor, read-only memory (ROM), random-access memory (RAM), input-output ports, timers, and other facilities. Receiving signals SG 1 , SG 2 , etc. from a higher-order controller 55 , the printing control unit 1 generates signals that control a sequence of operations for printing dot-mapped data given by signal SG 2 (sometimes referred to as a video signal because it supplies the dot-mapped data one-dimensionally). The printing sequence starts when the printing control unit 1 receives a printing command from the higher-order controller by means of control signal SG 1 . First, a temperature (Temp.) sensor 43 is checked to determine whether the fuser 44 is at the necessary temperature for printing. If it is not, current is fed to a heater 44 a to raise the temperature of the fuser 44 . [0007] When the fuser 44 is ready, the printing control unit 1 commands a motor driver 33 to drive a develop-transfer process motor (PM) 37 , activates a charge signal SGC to turn on a charging power source 32 , and thereby applies a voltage to the charging unit 35 to charge the surface of the photosensitive drum 51 . [0008] In addition, a paper sensor 41 is checked to confirm that paper is present in a cassette (not visible), and a size sensor 42 is checked to determine the size of the paper. If paper is present, a paper transport motor (PM) 38 is driven according to the size of the paper, first in one direction to transport the paper to a starting position sensed by a pick-up sensor 39 , then in the opposite direction to transport the paper into the printing mechanism 60 . [0009] When the paper is in position for printing, the printing control unit 1 sends the higher-order controller 55 a timing signal SG 3 (including a main scanning synchronization signal and a sub-scanning synchronization signal) as shown in FIG. 3. The higher-order controller 55 responds by sending the dot data for one page in the video signal SG 2 . The printing control unit 1 sends corresponding print data (HD-DATA) to the LED head 3 in synchronization with a clock signal (HD-CLK). The LED head 3 comprises a linear array of LEDs for printing respective dots (also referred to as picture elements or pixels). [0010] After receiving data for one line of dots in the video signal SG 2 , the printing control unit 1 sends the LED head 3 a latch signal (HD-LOAD), causing the LED head 3 to store the print data (HD-DATA), then sends the LED head 3 a strobe signal (HD-STB), causing the LED head 3 to output light according to the stored print data (HD-DATA), thereby forming one line of dots in the electrostatic latent image. Output of the strobe signal (HD-STB) may overlap the transfer of the next line of the video signal SG 2 and print data (HD-DATA), as illustrated in FIGS. 3 and 4. [0011] Subsequent lines of print data are sent and received in the video signal SG 2 in the same way. After each line has been stored, the LED head 3 is driven to emit light, selectively exposing the negatively charged surface of the photosensitive drum 51 to add another line of dots to the electrostatic latent image. When the printing control unit 1 activates control signal SG 5 , the developer power source 54 is switched on, applying a voltage to the developer 52 , and negatively charged toner particles are attracted to the parts of the electrostatic latent image that were exposed to light, forming a toner image comprising black pixels (dots). [0012] The photosensitive drum 51 continues to turn, carrying the toner image to the transfer unit 36 . The high-voltage transfer power source 32 is turned on by control signal SG 4 and supplies a positive voltage to the transfer unit 36 , whereby the toner image is transferred onto the paper 53 as it passes between the photosensitive drum 51 and the transfer unit. [0013] A temperature-humidity sensor 30 monitors the temperature and humidity inside the printer. The printing control unit 1 reads the temperature and humidity in the printer as necessary from the temperature-humidity sensor 30 , thereby obtaining information about environmental conditions. [0014] The printing control unit 1 has a table of transfer conditions corresponding to different ambient temperature and humidity conditions, and uses this table to select the optimum transfer conditions according to the environmental data read from the temperature-humidity sensor 30 . [0015] The paper 53 bearing the transferred toner image is transported to the fuser 44 . When the paper 53 meets the fuser 44 , the toner image is fused onto the paper 53 by heat generated by the heater 44 a. Finally, the printed sheet of paper passes an exit sensor 40 and is ejected from the printer. [0016] The printing control unit 1 controls the high-voltage transfer power source 32 according to the information detected by the size sensor 42 and pick-up sensor 39 so that voltage is applied to the transfer unit 36 only while paper 53 is passing between the transfer unit 36 and photosensitive drum 51 . When the paper 53 passes the exit sensor 40 , the printing control unit 1 turns off the high-voltage charging power source 31 and halts the developer-transfer process motor 37 . [0017] When a series of pages are printed, the above operations are repeated. [0018] [0018]FIG. 5 shows the conventional circuit structure of an LED head 3 . The print data signal HD-DATA and clock signal HD-CLK are received by a shift register 121 comprising, for example, two thousand four hundred ninety-six flip-flops FF 1 , FF 2 , . . . , FF 2496 (this number of flip-flops is suitable for printing three hundred dots per inch on A4-size paper). The latch signal HD-LOAD is received by a latch unit 122 comprising a corresponding number of latches LT 1 , LT 2 , . . . , LT 2496 , which latch the data output by the shift-register flip-flops. The strobe signal HD-STB is supplied to a circuit 123 comprising an inverter GO, NAND gates G 1 , G 2 , . . . , G 2496 , and switching elements (transistors) TR 1 , TR 2 , . . . , TR 2496 which are interconnected to drive a linear array of light-emitting elements (LEDs) LD 1 , LD 2 , . . . , LD 2496 when the latch and strobe signals are both low, provided the print data output from the corresponding latches are high (indicating black dots or, more generally, high-intensity pixels). The transistors TR 1 , TR 2 , . . . , TR 2496 operate as an array of driving elements, while the LEDs LD 1 , LD 2 , . . . , LD 2496 operate as an array of driven elements. The power source of the current that drives the light-emitting elements is denoted VDD. [0019] A problem encountered in this type of electrophotographic printer is that the size of a printed black dot depends on the number of other black dots nearby. Consequently, as the number of black dots in a given region varies, the blackness of the region (the total area occupied by the black dots) does not increase consistently. In particular, as the number of contiguous black dots in a rectangular region varies (this number is shown on the horizontal axis in FIG. 6), the area covered by the contiguous black dots (shown on the vertical axis) does not vary proportionally. As the number of black dots decreases, the size of the black area decreases more sharply (characteristic ‘a’) instead of decreasing proportionally (characteristic ‘b’). The reason for this phenomenon has to do with the characteristics of the transfer unit. [0020] A result of this problem is that when the printer prints very small letters, fine lines, and sparse (low-density) dither patterns, the printed lines and dots do not have the intended thickness (density) or size. Printing quality is degraded accordingly. [0021] Similar problems are encountered in color electrophotographic printers: the size of a printed high-intensity (i.e., non-white) pixel is affected by the number of other high-intensity pixels in its vicinity. This phenomenon is also seen in image recording apparatus other than electrophotographic apparatus. SUMMARY OF THE INVENTION [0022] An object of the present invention is to form an image in which the total area occupied by dots in an image area is proportional to the number of dots in the area, regardless of the dot density in the area. [0023] A further object of the invention is to form an image in which the total area occupied by dots in an image area is proportional to the number of dots in the area, regardless of ambient temperature and humidity variations. [0024] A first aspect of the invention provides a method of recording an image by supplying driving current to driven elements according to pixel data indicating pixel intensity. The method includes the step of adjusting the driving current supplied to form a high-intensity pixel according to intensities of other pixels nearby. Preferably, the driving current is increased as increasing numbers of low-intensity pixels are disposed near the high-intensity pixel, and greater weight is given to pixels in close proximity to the high-intensity pixel than to pixels that are farther away. The method may also include the steps of sensing ambient temperature and/or humidity conditions, and adjusting the driving current according to these conditions. [0025] The first aspect of the invention also provides an image recording apparatus that records an image by supplying driving current to driven elements according to pixel data indicating pixel intensity. The image recording apparatus includes an adjustment circuit that adjusts the driving current as described above, and may also include a sensor for sensing ambient temperature and/or humidity conditions, enabling the adjustment circuit to adjust the driving current according to those conditions as well. [0026] More specifically, the first aspect of the invention provides an image recording apparatus having an array of driven elements, an array of driving elements that record an image by supplying current to the driven elements according to pixel data, and a compensation circuit that adjusts the driving current supplied by each driving element. The compensation circuit includes an adjustment circuit that adjusts the driving current supplied to form a high-intensity pixel according to intensities of other pixels nearby, preferably according to the intensities of pixels in an M×N pixel block centered on the high-intensity pixel, where M and N are positive integers. The adjustment circuit may operate by comparing the M×N pixel block with a plurality of prestored patterns having prestored compensated data values. Each prestored pattern may have a plurality of compensated data values, which are selected according to ambient temperature and/or humidity conditions. [0027] The array of driven elements may comprise light-emitting elements for selectively illuminating a photosensitive member responsive to driving current, and the array of driving elements may be adopted to supply the driving current to respective light-emitting elements according to pixel data indicating pixel intensities, thereby forming an electrostatic latent image on the photosensitive member. [0028] A second aspect of the invention provides a method of recording an image by supplying driving current to driven elements according to pixel data indicating pixel intensity, including the step of altering the pixel data by changing a low-intensity pixel to a high-intensity pixel, thereby enlarging a contiguous group of high-intensity pixels, if the low-intensity pixel is surrounded by a predetermined pattern of high-intensity and low-intensity pixels. Preferably, this method also changes a high-intensity pixel to a low-intensity pixel, thereby enlarging a contiguous group of low-intensity pixels, if the high-intensity pixel is surrounded by another predetermined pattern of high-intensity and low-intensity pixels. The altered pixel data may vary over a range of intensity levels, depending on the surrounding pattern of pixels. The intensity level may also be selected according to ambient temperature and/or humidity conditions. [0029] The second aspect of the invention also provides an image recording apparatus that records an image by supplying driving current to driven elements according to pixel data indicating pixel intensity. The image recording apparatus includes an adjustment circuit that alters the pixel data by changing a low-intensity pixel to a high-intensity pixel as described above. [0030] More specifically, the second aspect of the invention provides an image recording apparatus having an array of driven elements, an array of driving elements that record an image by supplying current to the driven elements according to pixel data indicating pixel intensities, and a compensation circuit that adjusts the driving current supplied by each driving element. The compensation circuit includes an adjustment circuit that alters the pixel data by changing a low-intensity pixel to a high-intensity pixel as described above, preferably by changing the central pixel in an M×N pixel block according to the pattern of pixels in the block, preferably by comparing the M×N pixel block with a prestored plurality of M×N patterns, M and N being positive integers. The altered pixel data may vary over a range of intensity levels, depending on the surrounding pattern of pixels. [0031] The array of driven elements may comprise light-emitting elements for selectively illuminating a photosensitive member responsive to driving current, and the array of driving elements may be adopted to supply the driving current to respective light-emitting elements according to pixel data indicating pixel intensities, thereby forming an electrostatic latent image on the photosensitive member. BRIEF DESCRIPTION OF THE DRAWINGS [0032] In the attached drawings: [0033] [0033]FIG. 1 is a schematic sectional view of a conventional electrophotographic printer; [0034] [0034]FIG. 2 is a block diagram illustrating the control system of a conventional electrophotographic printer; [0035] [0035]FIG. 3 is a timing diagram illustrating the operation of a conventional electrophotographic printer; [0036] [0036]FIG. 4 is an enlarged timing diagram illustrating the signals supplied to an LED head; [0037] [0037]FIG. 5 is a circuit diagram of an LED head; [0038] [0038]FIG. 6 is a graph illustrating the dependence of dot area on dot density; [0039] [0039]FIG. 7 is a block diagram showing the relevant parts of an LED printer according to a first embodiment of the invention; [0040] [0040]FIG. 8 is a graph showing the relation between driving current and the amount of light emitted by an LED; [0041] [0041]FIG. 9 is a graph illustrating the surface-potential profiles of two dots in an electrostatic latent image; [0042] [0042]FIG. 10 is a more detailed block diagram of the print data compensation circuit in FIG. 7; [0043] [0043]FIGS. 11A, 11B, 11 C, 11 D, 11 E, 11 F, 11 G, and 11 H illustrate compensated print data output for various matching patterns in the first embodiment; [0044] [0044]FIG. 12A, 12B, 12 C, and 12 D illustrate dot sizes at various stages of the printing process in the first embodiment; [0045] [0045]FIG. 13 illustrates the dependence of dot area on dot density for normal conditions and high temperature and humidity conditions, and resulting overcompensation; [0046] [0046]FIG. 14 illustrates the dependence of dot area on dot density for normal conditions and low temperature and humidity conditions, and resulting undercompensation; [0047] [0047]FIG. 15 is a block diagram showing the relevant parts of an LED printer according to a second embodiment of the invention; [0048] [0048]FIG. 16 is a more detailed block diagram of the print data compensation circuit in FIG. 15; [0049] [0049]FIGS. 17A, 17B, 17 C, 17 D, 17 E, 17 F, 17 G, and 17 H illustrate compensated print data output for various matching patterns in the second embodiment; [0050] [0050]FIG. 18 illustrates the alteration of print data according to a first matching pattern in a third embodiment of the invention; [0051] [0051]FIG. 19 illustrates the alteration of print data according to a second matching pattern in the third embodiment; [0052] [0052]FIGS. 20A, 20B, and 20 C illustrate the effect of the alteration of print data according to the first matching pattern in the third embodiment; [0053] [0053]FIG. 21A, 21B, and 21 C illustrate the combined effect of the alteration of print data according to the first and second matching patterns in the third embodiment; [0054] [0054]FIG. 22 illustrates this combined effect of the third embodiment in a standardized form; [0055] [0055]FIGS. 23, 24, 25 , 26 , 27 , and 28 illustrate the enlargement of various groups of black pixels in the third embodiment; [0056] [0056]FIG. 29 illustrates the enlargement of a white pixel to a group of three white pixels in the third embodiment; [0057] [0057]FIGS. 30A, 30B, and 30 C illustrate an isolated black pixel and the resulting alteration of print data in a fourth embodiment of the invention; [0058] [0058]FIGS. 31A, 31B, 31 C, 32 A, 32 B, and 32 c illustrate isolated groups of two black pixels and the resulting alteration of print data in the fourth embodiment; [0059] [0059]FIGS. 33A, 33B, and 33 C illustrate an isolated white pixel and the resulting alteration of print data in the fourth embodiment; and [0060] [0060]FIG. 34 illustrates a variation of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION [0061] Embodiments of the invention will be described with reference to the attached drawings, in which like parts are indicated by like reference characters. The embodiments are electrophotographic apparatus including a photosensitive member such as a photosensitive drum 51 , developer 52 , and other elements shown in FIGS. 1 and 2. [0062] The first embodiment is an electrophotographic printer having the overall circuit structure shown in FIG. 7. The printer comprises a printing control unit 1 , a print data compensation circuit 2 , and an LED head 3 . The printing control unit 1 supplies a print data signal, also referred to below as a video signal S 4 , to the print data compensation circuit 2 , and receives a print timing signal S 5 from the print data compensation circuit 2 . The print data compensation circuit 2 supplies a compensated print data signal S 7 , a transfer clock signal S 8 , and a latch signal S 9 to the LED head 3 . The LED head 3 receives the compensated print data signal S 7 in synchronization with the transfer clock signal S 8 , and stores the compensated print data S 7 in synchronization with the latch signal S 9 . The LED head 3 also receives a print driving signal or strobe signal S 6 from the printing control unit 1 . [0063] The LED head 3 is of the gray-scale type that receives multiple bits of print data indicating the intensity or gray level of each pixel. In the following description, it will be assumed that there are four bits of print data per pixel. Depending on the input four-bit value, the LED head 3 generates varying amounts of driving current, yielding varying amounts of optical energy output. The relation between LED driving current and the amount of light emitted by the LED is substantially linear. FIG. 8 shows LED driving current on the horizontal axis and the amount of light emitted by the driven LED on the vertical axis. The optical energy output increases with the emitted amount of light. [0064] [0064]FIG. 9 illustrates the gray-scale operation in more detail by showing two toner dot images Da and Db and their potential profiles on the photosensitive drum 51 . The horizontal direction in FIG. 9 corresponds to the longitudinal (axial) direction of the photosensitive drum 51 . The vertical axis of the graph in the upper part of FIG. 9 indicates the surface potential of the photosensitive drum 51 , dotted line DSP indicating the surface potential of a roller in the developer 52 that carries toner to the photosensitive drum. [0065] When the input data value and thus the energy output are small, the emitted light forms an electrostatic latent image of a comparatively small dot, such as dot Da in FIG. 9, thereby creating a comparatively small dot in the toner image developed on the photosensitive drum 51 and the printed image transferred to the recording medium such as recording paper. When the input data value and thus the energy output are larger, the emitted light forms an electrostatic latent image of a comparatively larger dot, such as dot Db, thereby creating a comparatively larger dot in the toner image and printed image. [0066] Since the size of a printed dot varies with the optical energy output by the corresponding LED, the printed dot size can be varied within a set range, in steps equivalent to an increment of one in the four-bit pixel-intensity data value, as described, for example, in Japanese Unexamined Patent Publication No. H7-246730. [0067] The print data compensation circuit 2 modifies the print data received from the printing control unit 1 in order to drive the LEDs in the LED head 3 with the optimal driving current. If the compensated print data signal S 7 is a four-bit signal, the standard output value of the LED head corresponds to, for example, an S 7 value of ‘1000.’ No LED driving current is produced when the S 7 signal value is ‘0000.’ The driving current increases as the S 7 signal value increases from ‘0000’ to ‘0001,’ then to ‘0010,’ and so on, maximum current being supplied when the S 7 signal value is ‘1111.’ [0068] The LED head 3 may further modify the received print data S 7 in order to compensate for differences between individual LEDs, for example, or for differences among the LED array chips making up the linear array of LEDs, arising from manufacturing-process variations. [0069] Although the compensated print data signal S 7 in this embodiment is a gray-scale signal with multiple bits per pixel, the video signal S 4 need not be a gray-scale signal. In the following description, it will be assumed that the video signal S 4 is a binary signal with only one bit per pixel. The one-bit value indicates whether the pixel is a high-intensity pixel (i.e., a black or other-colored pixel) or a low-intensity pixel (i.e., a white pixel, for which no toner dot is printed). [0070] [0070]FIG. 10 shows an example of the internal structure of the print data compensation circuit 2 . The component elements are a one-line buffer (Buf.) 10 , a five-line buffer 11 , a selector 12 , a receiving address generator (Rx Addr.) 13 , a transmitting address generator (Tx Addr.) 14 , a timing generator 15 , a column buffer 16 , a latch unit 124 comprising five latch circuits (L) 17 - 21 , and an adjustment circuit 22 . The buffers 10 , 11 , 16 , selector 12 , address generators 13 , 14 , timing generator 15 , and latch unit 124 form an extraction circuit 125 for extracting five-by-five blocks of pixel data. The column buffer 16 functions as a readout circuit. [0071] The video signal S 4 from the printing control unit 1 is received by the column buffer 16 , input to the one-line buffer 10 one bit at a time, and transferred one entire line at a time to the five-line buffer 11 . The five-line buffer 11 stores the most recently received five lines of print data contained in the video signal. [0072] The five lines of print data stored in the five-line buffer 11 are transferred in parallel through the column buffer 16 into the latch circuits 17 - 21 , the data for five vertically aligned pixels being transferred at once. These five bits of data first enter latch circuit 17 , and are then shifted successively into latch circuits 18 , 19 , 20 , 21 . The latch circuits 17 - 21 collectively store data for a five-by-five block of pixels, disposed in five mutually adjacent rows and five mutually adjacent columns in the image. [0073] The data stored in the latch circuits 17 - 21 are also output to the adjustment circuit 22 . The adjustment circuit 22 thus receives data for a five-by-five block of pixels, on the basis of which the adjustment circuit 22 outputs compensated print data S 7 for the single pixel disposed at the center of the block. The adjustment circuit 22 generates the compensated print data by, for example, comparing each input five-by-five pixel block with a set of prestored combinatorial patterns, also referred to below as matching patterns; deciding which matching pattern is matched by the input block; and outputting a prestored four-bit compensated value, according to which the LED head 3 drives the LED corresponding to the horizontal position of the pixel at the center of the five-by-five pixel block. [0074] The receiving address generator 13 designates the locations in the five-line buffer 11 at which data input from the one-line buffer 10 are stored. The transmitting address generator 14 designates the locations in the five-line buffer 11 from which data are read out to the column buffer 16 . The selector 12 selects either the output of the receiving address generator 13 or the output of the transmitting address generator 14 , depending on whether the five-line buffer 11 is currently being written or read, and supplies the selected output address to the five-line buffer 11 . The timing generator 15 generates timing signals and clock signals for the other elements in the print data compensation circuit 2 . These signals include a receive clock signal S 25 supplied to the receiving address generator 13 , and the transfer clock signal S 8 mentioned above, which is supplied to the transmitting address generator 14 and the latch circuits 17 - 25 as well as the LED head 3 . The timing generator 15 also generates the latch signal S 9 supplied to the LED head 3 , and the timing signal S 5 supplied to the printing control unit 1 . [0075] The first embodiment operates as follows. [0076] When the printing mechanism 60 is ready, the printing control unit 1 sends the conventional timing signal SG 3 to the higher-order controller 55 , which responds by sending the printing control unit 1 a video signal SG 2 with print data for one page. The printing control unit 1 transfers the print data to the print data compensation circuit 2 in the video signal S 4 . [0077] In the print data compensation circuit 2 , the timing generator 15 activates the receive clock signal S 25 at the end of each received line of print data, causing the line to be transferred from the one-line buffer 10 to the five-line buffer 11 and stored in the five-line buffer at the addresses designated by the receiving address generator 13 . The transferred line replaces the oldest line of data stored in the five-line buffer 11 , so that the five-line buffer always stores the most recent five lines of data. [0078] In synchronization with the transfer clock signal S 8 , the transmitting address generator 14 generates successive read addresses in the five-line buffer 11 , each address enabling the column buffer 16 to read data for a column of five vertically aligned pixels. These data are shifted through the data latches 17 - 21 ; while residing in the data latches, the data are also supplied to the adjustment circuit 22 . The adjustment circuit 22 thus receives data for successive five-by-five blocks of pixels centered at image positions that shift horizontally by one pixel at a time. The adjustment circuit 22 outputs four-bit compensated print data S 7 for the center pixel in each block. These data are supplied to the LED head 3 . [0079] When the address generated by the transmitting address generator 14 reaches the end of a line, the reading of data from the five-line buffer 11 temporarily stops until the data for a new line have been transferred from the one-line buffer 10 to the five-line buffer 11 ; then the reading of data resumes, the transmitting address generator 14 starting over from the beginning of the line. [0080] Next, the operation of the adjustment circuit 22 will be described in more detail. FIGS. 11A to 11 H illustrate some of the matching patterns prestored in the adjustment circuit 22 , and indicate the compensated four-bit print data output for each pattern. In each pattern, high-intensity pixels are indicated by circles (O) and low-intensity pixels by crosses (X). For the sake of simplicity, high-intensity pixels will also be referred to as black pixels and low-intensity pixels as white pixels, although the high-intensity pixels may actually have various colors other than black. The four-bit data value is the value output for the pixel at the center of each pattern. [0081] If, for example, the data received from the data latches 17 - 21 match the pattern shown in FIG. 11A, the adjustment circuit 22 outputs ‘1110’ as a compensated print data value for the central pixel in this five-by-five pixel block. [0082] As can be seen from FIGS. 11A to 11 H, the compensated print data values have a general tendency to increase as the number of white pixels disposed around the central black pixel in the five-by-five block increases, but this tendency depends more on the values of the pixels relatively close to the central pixel than on the values of pixels farther from the central pixel. For example, the pattern in FIG. 11B yields a higher compensated print data value than the pattern in FIG. 11E, because although both patterns include twenty-three white pixels, in FIG. 11B all of the four pixels closest to (immediately above, below, right, and left of) the center position are all white, whereas in FIG. 11E only three of these four pixels are white. [0083] To complete the five-by-five blocks of pixels centered at the first two pixel positions and the last two pixel positions in each line, for which incomplete data are received from the data latches 17 - 21 , the adjustment circuit 22 assumes that the missing pixels are white. This assumption is made because the missing pixels correspond to positions in the left and right margins on the page, which are normally white. A similar assumption is made for missing pixels in the blocks centered on the first two and last two lines on each page, corresponding to positions in the top and bottom margins. [0084] All of the prestored patterns have black pixels at the center position. The corresponding compensated print data for these patterns may range from ‘0001’ to ‘1111.’ If the central pixel is white, the compensated print data value is ‘0000.’ [0085] The LED head 3 supplies sixteen levels of driving energy (current) to its component LEDs, corresponding to received data values from ‘0000’ to ‘1111.’ For comparatively high values such as ‘1111,’ the output optical energy and the resulting toner dot are larger than the standard energy and dot size. This compensates for the tendency of the size of the toner dots transferred to the paper by the transfer unit 36 to decrease with decreasing dot density, as illustrated in FIG. 6. If appropriate matching patterns and compensated print data are stored in the adjustment circuit 22 , the size of the transferred dots can be adjusted so that all transferred dots have substantially the intended uniform size, regardless of the dot density. [0086] The adjustment is illustrated one-dimensionally in FIGS. 12A to 12 D. FIG. 12A shows an example of a line of input print data including one isolated black pixel (X), two consecutive black pixels (Y), and three consecutive black pixels (Z). If vertically adjacent pixels are ignored, the adjustment circuit 22 adjusts the data for pixel X so that a comparatively large electrostatic latent dot image is formed on the photosensitive drum, as illustrated in FIG. 12B. The electrostatic latent images of the two consecutive dots Y are smaller, and the electrostatic latent images of the three consecutive dots Z are smaller still. When these electrostatic latent images are developed and transferred to paper, however, the toner dots formed on the paper are all of substantially identical size, as illustrated in FIG. 12C. FIG. 12D illustrates the similar adjustment for three vertically contiguous dots. [0087] As FIGS. 12B and 12C show, the toner dot transferred to the paper is always smaller than the corresponding electrostatic latent dot image formed on the photosensitive drum, but whereas the size of a transferred dot surrounded by neighboring dots is only slightly smaller than the latent image size, the size of an isolated transferred dot is much smaller than the latent image size. With a conventional LED head, which supplies uniform optical energy for all dots, fine lines and small print have a tendency to become faint when transferred to paper. By adjusting the print data to increase the size of comparatively isolated dots, the present embodiment corrects this tendency so that fine lines and small print are printed with the full intended size, improving the quality of the printed image. [0088] Although the first embodiment has been described as using five-by-five matching patterns, it is possible to use M×N matching patterns, where M and N are arbitrary positive integers (e.g., odd integers greater than one), by providing an N-line buffer and M data latches in the adjustment circuit 22 . [0089] Although the first embodiment compensates for the dependency of transferred dot size on dot density, the transferred dot size also depends on environmental conditions such as temperature and humidity inside the printer. Specifically, as the temperature and humidity increase, the paper tends to absorb more moisture, and its electrical resistance decreases correspondingly. Other factors (such as transfer voltage, driving current, and driving time) being equal, the reduced electrical resistance leads to more efficient toner transfer than under low-temperature, low-humidity conditions. [0090] [0090]FIG. 13 illustrates this environmental effect. The horizontal and vertical axes have the same meaning as in FIG. 6. Characteristic A, which is identical to characteristic ‘a’ in FIG. 6, shows the tendency of dot size (black area) to decrease with decreasing dot density under normal temperature and humidity conditions. Under high temperature and humidity conditions, the decrease in dot size is considerably less, as illustrated by characteristic B. Thus an adjustment that yields the correct dot size under normal conditions, by shifting characteristic A to characteristic D, will overcompensate under high temperature and humidity conditions by shifting characteristic B to characteristic C, so that the dots in low-density image areas are larger than intended. [0091] [0091]FIG. 14 illustrates the effect of abnormally low temperature and humidity. Characteristic A again indicates the density dependence of dot size (black area) under normal temperature and humidity conditions. Under low temperature and humidity conditions, the dependence becomes stronger; dot size decreases more sharply as the dot density is decreased. Thus an adjustment that corrects characteristic A to characteristic D under normal conditions undercompensates under low temperature and humidity conditions, so that characteristic B is only corrected to characteristic C, and low-density dots are still printed too small. [0092] Referring now to FIG. 15, a second embodiment of the invention adds a temperature-humidity sensor 30 to the structure shown in FIG. 7. The temperature-humidity sensor 30 sends an environmental data signal S 28 , indicating ambient temperature and humidity conditions, to the printing control unit 1 , as in the conventional electrophotographic printer shown in FIG. 1. On the basis of this information, the printing control unit 1 sends the print data compensation circuit 2 an environmental signal S 61 having three possible values, indicating whether the ambient temperature and humidity conditions are high, normal, or low. [0093] The print data compensation circuit 2 in this embodiment has, for example, the internal structure shown in FIG. 16, adding a selection circuit 29 to the structure shown in the first embodiment. The selection circuit 29 receives the environmental data signal S 61 . The adjustment circuit 22 now stores three compensated print data values for each matching pattern, the three values being suitable for low, normal, and high temperature and humidity conditions, respectively. Upon receiving a five-by-five block of pixel data from the latch circuits 17 - 21 , the adjustment circuit 22 sends all three data values for the corresponding matching pattern to the selection circuit 29 . The selection circuit 29 selects one of the three values according to the environmental data signal S 61 ; the selected value becomes the compensated print data signal S 7 supplied to the LED head 3 . [0094] Examples of the three values A, B, C stored for various matching patterns are shown in FIGS. 17A to 17 H. Value A is suitable for high temperature and humidity conditions, value B for normal temperature and humidity conditions, and value C for low temperature and humidity conditions. Taking the matching pattern in FIG. 17A as an example, the selected value is ‘1101’ (value A) under high temperature and humidity conditions, ‘1110’ (value B) under normal temperature and humidity conditions, and ‘1111’ (value C) under low temperature and humidity conditions. (Analogous descriptions of FIGS. 17B to 17 H will be omitted.) By providing a selection of compensated print data values for different environmental conditions, the second embodiment avoids the type of overcompensation illustrated in FIG. 13 and undercompensation illustrated in FIG. 14. The size of the transferred toner dots depends neither on the dot density nor on the ambient temperature and humidity, so a uniformly high printing quality is maintained under all environmental conditions. [0095] In a variation of the preceding embodiments, the adjustment circuit 22 calculates the compensated print data values as a weighted sum of the values of the pixels in the pixel block received from the data latches, instead of comparing the received pixel block with prestored matching patterns. In this variation, the adjustment circuit 22 need store only a comparatively small number of weighting coefficients, instead of a larger number of matching patterns, and can generate the compensated print data by a simple multiply-accumulate operation, instead of a pattern matching operation. [0096] Next, a third embodiment will be described. The third embodiment has a hardware structure similar to that of the first embodiment, shown in FIGS. 7 and 10, but differs in that the LED head 3 does not have a gray-scale capability, and the compensated print data are binary data, each pixel being represented by a one-bit value indicating whether the corresponding LED is to be driven or not. [0097] The adjustment circuit 22 in the print data compensation circuit 2 in the third embodiment adjusts the print data by adding additional dots to isolated groups of dots. For example, when the print data compensation circuit 2 recognizes an isolated group of one, two, or three black pixels, it adds two more black pixels to the group, by changing two adjacent pixels from white to black. Similarly, when the print data compensation circuit 2 recognizes an isolated group of one, two, or three white pixels, it adds two more white pixels to the group, by changing two adjacent pixels from black to white. [0098] Like the adjustment circuit 22 in the first embodiment, the adjustment circuit 22 in the third embodiment receives a five-by-five pixel block from the data latches 17 - 21 . Table 1 summarizes the operation of the adjustment circuit 22 by showing the number of black pixels in the block, the number of black pixels added or deducted by the adjustment circuit 22 , and the resulting number of black pixels in the output block. TABLE 1 Number of black pixels in five-by-five block Input Change Output  1 black pixel +2  3 black pixels  2 black pixels +2  4 black pixels  3 black pixels +2  5 black pixels  4 black pixels +1  5 black pixels  5 black pixels +1  6 black pixels  6 black pixels +1  7 black pixels  7 black pixels +1  8 black pixels  8 black pixels 0  8 black pixels  9 black pixels 0  9 black pixels 10 black pixels 0 10 black pixels . . . . . . . . . 15 black pixels 0 15 black pixels 16 black pixels 0 16 black pixels 17 black pixels 0 17 black pixels 18 black pixels −1 17 black pixels 19 black pixels −1 18 black pixels 20 black pixels −1 19 black pixels 21 black pixels −1 20 black pixels 22 black pixels −2 20 black pixels 23 black pixels −2 21 black pixels 24 black pixels −2 22 black pixels [0099] The changes in Table 1 are performed by adding one or two black pixels at positions adjacent to an isolated contiguous group of one to seven black pixels in a five-by-five block, or by deleting one or two black pixels at positions adjacent to an isolated contiguous group of one to seven white pixels, where contiguous means horizontally, vertically, or diagonally contiguous. No pixel values are changed when all the pixels in the five-by-five block are black, or all are white. [0100] In the description that follows, when the five-by-five pixel block stored in the latch circuits 17 - 21 matches one of the prestored matching patterns, the pixel at the center of the block is changed. The block stored in the latch circuits shifts in both the row and column directions. First, the block shifts horizontally from the first column to the last column, staying in the same five rows; then it moves down one row, returns to the first column position, and begins shifting horizontally again. As the block moves in this way, each pixel occupies the center of the block just once, at which time the pixel may be changed from black to white or from white to black if the surrounding pixels match one of the matching patterns. As this process is repeated, an isolated black or white pixel acquires a certain number of neighboring black or white pixels in predetermined relative positions. [0101] The process of adding two black pixel to a single isolated black pixel located in column M, row N+1, will be illustrated below as an example. [0102] One of the matching patterns stored in the adjustment circuit 22 (pattern a-1, illustrated in FIG. 18) changes the central pixel in a five-by-five pixel block from white to black if that pixel is disposed immediately above an isolated black pixel, all other pixels in the block being white. Another matching pattern stored in the adjustment circuit 22 (pattern a-2, illustrated in FIG. 19) changes the central pixel from white to black if that pixel is disposed immediately to the left of an isolated black pixel, all other pixels in the block being white. In these and the following drawings, an X indicates a white pixel, a white circle indicates a pixel that was originally black and remains black, and a black circle indicates a pixel that has been changed from white to black. [0103] As a result of matching pattern a-1, the pixel in column M, row N (the central pixel in FIG. 20A) is changed from white to black, as indicated in FIG. 20B. Accordingly, after the change in FIG. 20B, there are two black pixels in the five-by-five block, as shown in FIG. 20C. This change is reflected in the compensated print data output to the LED head 3 , but does not alter the data stored in the five-line buffer 11 or the latch circuits 17 - 21 . [0104] As a result of matching pattern a-2, the pixel in column M−1, row N+1 (the central pixel in FIG. 21A) is also changed from white to black, as indicated in FIG. 21B. As a result of this further change, the original isolated black pixel has become a group of three black pixels, as shown in FIG. 21C, in the compensated print data S 7 supplied to the LED head 3 . [0105] [0105]FIG. 22 illustrates the process of adding two black pixels to a single isolated black pixel in a standardized form, with the first pixel to be changed disposed at the center of the block. Using this standardized form, FIGS. 23, 24, 25 , and 26 illustrate patterns that result in the addition of two black pixels to a group of two or three black pixels. FIGS. 27 and 28 illustrate patterns that add one black pixel to a group of five or six black pixels. FIG. 29 illustrates a pattern that adds two white pixels to an isolated white pixel. [0106] Experiments performed by the inventors have shown that it is preferable to enlarge isolated groups of pixels by adding the numbers of pixels given in Table 1, even though the resulting pixel arrangements may be asymmetrical, as illustrated in FIGS. 22 to 29 . If, for example, a single isolated black pixel were to be enlarged to a group of five pixels by adding black pixels symmetrically above, below, and to the right and left of the isolated pixel, the resulting printed dot would be larger than intended. [0107] Although the third embodiment does not adjust the sizes of individual dots, by adjusting the number of black dots in a contiguous group according to the size of the group, and adjusting the number of white dots in a contiguous group according to the size of the group, it achieves substantially the same effect as the first embodiment. That is, despite the tendency of the transfer unit 36 to transfer less toner from the photosensitive drum 51 to the paper 53 when a black pixel has relatively few neighboring black pixels, the total size of the black area produced by the compensated print data in the third embodiment is approximately proportional to the number of black pixels in the original print data S 4 , generally following characteristic ‘b’ rather than characteristic ‘a’ in FIG. 6. [0108] The positions at which black and white pixels are added to isolated groups are not restricted to those shown in FIGS. 22 to 29 . The same effect can be obtained by adding pixels at different positions, provided the number of pixels added conforms to Table 1. [0109] Next, a fourth embodiment will be described. The fourth embodiment combines features of the first and third embodiments. [0110] Like the first embodiment, the fourth embodiment employs an LED head 3 with a gray-scale capability, and adjusts the sizes of individual black dots according to the number and proximity of neighboring black dots. Like the third embodiment, the fourth embodiment also increases the number of dots in a small isolated group of black or white dots. [0111] The fourth embodiment has the same hardware structure as the first embodiment, shown in FIGS. 7 and 10, but differs with regard to the operation of the adjustment circuit 22 . The operation will be described through several examples below. [0112] When the adjustment circuit 22 in the fourth embodiment recognizes a single isolated black pixel as in FIG. 30A, it adds four more black pixels at the vertically and horizontally adjacent positions, as shown in FIG. 30B. In the compensated print data for the resulting group of five black pixels, the original black pixel has the value ‘1110’ (value A in FIG. 30C), so more than the standard amount of driving current is supplied to the corresponding LED, as in the first embodiment. The compensated values of the four added pixels are ‘0100’ (value B in FIG. 30C), resulting in less than the standard amount of driving current. The notations +6 and −4 in FIG. 30C represent the algebraic difference between the supplied driving current and the standard amount, in units equivalent to the least significant bit of the compensated print data. [0113] Similarly, an isolated group of two vertically adjacent black pixels, as in FIG. 31A, is given two additional black pixels, as in FIG. 31B, the original black pixels having compensated data values of ‘1101’ (five units above the standard value) and the additional black pixels having compensated data values of ‘0101’ (three units below the standard value), as indicated in FIG. 31C. [0114] An isolated group of two diagonally adjacent black pixels, as shown in FIG. 32A, is also given two additional black pixels, as shown in FIG. 32B, the original black pixels again having compensated data values of ‘1101’ and the additional black pixels now having compensated data values of ‘0110’ (two units below the standard value), as indicated in FIG. 32C. [0115] An isolated white pixel, as shown in FIG. 33A, remains isolated, as shown in FIG. 33B, but the data values of the four horizontally and vertically adjacent black pixels are reduced by four units (from ‘1000’ to ‘0100’), as indicated by the letter A in FIG. 33C. That is, the size of the four adjacent black dots is reduced, to increase the visibility of the printed white dot. The white pixel itself (C) remains white (‘0000’), and the other surrounding black pixels (B) retain the standard black level (‘1000’) in the compensated print data. [0116] As these four patterns show, the fourth embodiment enables compensation to be applied more symmetrically than in the third embodiment. In the printed image, fine detail is faithfully aligned, and small fonts are printed with the appearance intended by the font designer. [0117] In addition, the amount of toner transferred from the photosensitive drum 51 to the paper can be adjusted more precisely than in any of the preceding embodiments, since the data values of both the pixel of interest and its adjoining pixels are adjusted. [0118] For example, in the third embodiment, isolated groups of both three and four black or white pixels were enlarged to groups of five black or white pixels, causing different input data to produce substantially the same compensated effect. In the fourth embodiment, the data values of the added pixels can be adjusted so that different input data always produce different compensated effects. [0119] The precision of the compensation applied in the first embodiment is directly limited by the coarseness of the gray scale of the LED head 3 (the difference between adjacent gray levels). This precision could be increased only by increasing the number of bits of data per pixel, a costly undertaking involving extensive circuit redesign of the LED head. In the fourth embodiment, however, the precision of the compensation is not directly limited by the coarseness of the gray scale, since additional precision can be obtained by adjusting the data values of adjoining pixels, and this additional precision is obtained by altering only the internal logic of the adjustment circuit 22 , which can be done relatively inexpensively. [0120] The fourth embodiment is thus capable of reproducing fine lines, small print, and other fine detail with very high quality and fidelity at a comparatively low cost. [0121] In a variation of the fourth embodiment, the added pixels are divided into sub-pixels and are vertically offset by being formed on sub-raster lines. Referring to FIG. 34, when a pixel 70 is added immediately above an isolated pixel 74 , instead of being centered on the normal raster line 71 , the added pixel is divided into two overlapping sub-pixels 72 , which are centered on two sub-raster lines 73 disposed below the normal raster line 71 . In this case, the isolated pixel 74 may also be subdivided into, for example, four sub-pixels 75 , which are centered on respective raster and sub-raster lines. The use of sub-raster lines provides a further capability for fine-tuning the size of dots, lines, and other fine detail in the printed image. [0122] In another variation of the fourth embodiment, a temperature and humidity sensor is added as in the second embodiment, and different print data are supplied to the LED head 3 , depending on ambient temperature and humidity conditions. [0123] In a variation of any of the preceding embodiments, the LEDs in the LED head are divided into a certain number ‘a’ of groups. If the LEDs are numbered in their order of position in the linear array, the first group, denoted group zero, includes the first LED (LED 0, equivalent to LD 1 in FIG. 5), and every a-th subsequent LED. Similarly, the second group (group one) includes the second LED (LED 1, equivalent to LD 2 in FIG. 5) and every a-th subsequent LED. The composition of the groups is summarized in Table 2. TABLE 2 Grouping of LEDs Group LEDs 0 0, a, 2a, 3a, . . . 1 1, a + 1, 2a + 1, 3a + 1, . . . 2 2, a + 2, 2a + 2, 3a + 2, . . . . . . . . . a − 1 (a − 1), a + (a − 1), 2a + (a − 1), 3a + (a − 1), . . . [0124] In this variation, the LED head 3 is first supplied with compensated print data for group zero, and the LEDs in group zero are driven according to the supplied data. Next, compensated print data for the LEDs in group one are supplied, and those LEDs are driven. Operation continues in this way until the LEDs in group (a−1) have been driven, completing the formation of one line of pixels in the electrostatic latent image; then the same operation repeats from group zero to form the next line of pixels. The output order of the compensated print data can be rearranged in this way by providing the print data compensation circuit 2 with extra buffer memory for the output values. The advantage of this scheme is that it avoids the excessive current flow associated with the simultaneous driving of a large number of LEDs. [0125] The invention has been described in relation to a monochrome printer, but can also be practiced in a color printer. In this case, the terms ‘black’ and ‘white’ in the foregoing description should be replaced by ‘high-intensity’ and ‘low-intensity,’ respectively. [0126] The invention is applicable not only to LED printers but to other types of electrophotographic apparatus as well, including facsimile machines and digital copiers. The light-emitting elements need not be LEDs; other types of light-emitting elements may be employed. [0127] The invention can also be practiced in non-electrophotographic types of image-recording apparatus, such as thermal printers, in which an image is formed by supplying various amounts of driving current to an array of resistive heat-emitting elements. [0128] The data received by the compensation circuit are not restricted to one bit per pixel. The compensation circuit may receive gray-scale data with multiple bits per pixel, so that a pixel can have a range of intensity levels. In this context, the term ‘low-intensity’ as used herein refers to the minimum intensity level, and ‘high-intensity’ refers to any other intensity level. [0129] Those skilled in the art will recognize that further variations are possible within the scope claimed below.

A dot-matrix image-forming device such as an electrophotographic printer alters the size of a dot according to the surrounding dot pattern, thereby compensating for the tendency of isolated dots or small groups of dots to be undersized due to characteristics of the image formation process. Alternatively, the device may add dots to or delete dots from a contiguous group of dots to achieve substantially the same effect. Preferably, the device both adds or deletes dots and alters the dot size. This compensation scheme enables the total area occupied by dots in a given image region to be proportional to the number of dots in the region, regardless of the dot density and arrangement in the region.

This application is a division of U.S. application Ser. No. 10/597,658, filed Aug. 2, 2006, which is a U.S. National Stage application of International Application No. PCT/JP2005/011456, filed Jun. 22, 2005, which application is incorporated herein by reference. TECHNICAL FIELD The present invention relates to an amalgam-enclosed fluorescent lamp, an illumination device including the fluorescent lamp, and a method for manufacturing the fluorescent lamp. BACKGROUND ART The amount of mercury required to be enclosed in the lamp desirably is as small as possible from the viewpoint of environmental protection. Therefore, it is required that a minimum amount of mercury should be enclosed in a glass bulb with high precision. However, mercury has a high surface tension, which makes it difficult to measure off a small amount of the same accurately. Besides, since it tends to adhere to a wall of a discharge thin tube or the like, the loss of mercury occurring during enclosure is considerable. Therefore, conventionally, an amalgam of mercury in a pellet form has been enclosed in place of pure mercury. For instance, the patent document 1 discloses a fluorescent lamp in which an amalgam containing mercury and zinc as principal components (hereinafter referred to as ZnHg) is enclosed. The patent document 2 discloses a fluorescent lamp in which an amalgam containing mercury and tin as principal components (hereinafter referred to as SnHg) is enclosed. Problems have arisen in the configurations with ZnHg and SnHg, respectively. The problem with the configuration with ZnHg is that in a manufacturing process, when an amalgam pellet is brought into a heated glass bulb, an amount of mercury vapor released from the amalgam pellet is small. It is known generally that upon the first lighting of the fluorescent lamp, mercury vapor is consumed rapidly due to physical adsorption onto an internal wall of the glass bulb or chemical reaction with a phosphor-film-forming material or an impurity gas, causing the mercury vapor level to tend to be insufficient. Further, recently, with a view to improving the lamp efficiency, the internal diameter of the glass bulb tends to decrease while the discharge path tends to increase, thereby making it difficult to cause mercury vapor to spread throughout the glass bulb, which makes the mercury vapor level more insufficient. If a fluorescent lamp is left to be on for a long time in such a state of insufficient mercury vapor, lighting defects such as non-lighting or flickering occur, or a circuit for lighting is overloaded. Therefore, problems of lighting defects, etc. tend to occur in a fluorescent lamp in which ZnHg is used. On the other hand, the problem lying in the configuration with SnHg is that an amalgam pellet is heavy. Since the mercury content of SnHg is smaller than that of ZnHg, when SnHg is used, the weight of an amalgam pellet has to be increased further so as to enclose the same amount of mercury as that in the case of ZnHg. If an amalgam pellet is heavy, the amalgam pellet tends to cause the phosphor film to peel off when it collides against a phosphor film due to vibration during transportation or the like, thereby impairing the appearance of the fluorescent lamp, etc. It should be noted that an amalgam pellet of SnHg is stable in the case where the mercury content therein is in a range of 15.8 wt % to 29.7 wt %, and in the case where the mercury content is set to be more than that, mercury leaks out of the amalgam pellet in some cases. Therefore, it is difficult to increase an amount of enclosed mercury by increasing the mercury content in the pellet. Patent document 1: JP 3027006 B Patent document 2: JP 2000-251836 A DISCLOSURE OF INVENTION In light of the foregoing problems, the present invention provides a fluorescent lamp that is characterized in that an amount of released mercury vapor that is necessary for the first lighting of a fluorescent lamp is secured, and that a phosphor film is less prone to peeling due to an amalgam, an illumination device that includes such a fluorescent lamp, and a method for manufacturing such a fluorescent lamp. A fluorescent lamp of the present invention is a fluorescent lamp including a glass bulb provided with a phosphor film on its internal face, in which a rare gas and an amalgam pellet are enclosed. This fluorescent lamp is characterized in that: the amalgam pellet contains zinc, tin, and mercury, one or a plurality of the amalgam pellets are enclosed in the glass bulb, and each of the amalgam pellets has a weight of not more than 20 mg; and the fluorescent lamp satisfies the relationship expressed as: 45×(1− A )≦ x≦ 55×(1− A ), 75A≦y≦85A, 45−30 A≦z≦ 55−30 A , and x+y+z≦ 100, where A represents a value whose lower limit is determined as: A≧ 0.3−( S/ 25) and A≧ 0.1 when 0 <L 2 /D≦ 1.5×10 4 , A≧ 0.4−( S/ 25) and A≧ 0.2 when 1.5×10 4 <L 2 /D≦ 5×10 4 , or A≧ 0.5−( S/ 25) and A≧ 0.3 when 5×10 4 <L 2 /D< 8.5×10 4 , where D represents an internal diameter of the glass bulb in millimeters, L represents a length of a discharge path in millimeters, S represents a surface area of the amalgam pellet in square millimeters, x represents a content of zinc in percent by weight, y represents a content of tin in percent by weight, and z represents a content of mercury in percent by weight. An illumination device of the present invention is characterized by including the foregoing fluorescent lamp. A fluorescent lamp manufacturing method of the present invention is a method for manufacturing the foregoing fluorescent lamp, and is characterized by including the steps of: forming the phosphor film on the internal face of the glass bulb; and enclosing the amalgam pellet in the glass bulb, wherein in the amalgam enclosing step, the glass bulb is kept at a temperature of not lower than 260° C. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a partially cut-away plan view illustrating a straight-shape fluorescent lamp according to Example 1 of the present invention. FIGS. 2A and 2B illustrate a mount assembling step according to an example of the present invention. FIG. 2A illustrates members composing a glass mount, and FIG. 2B illustrates the glass mount after the assembling. FIGS. 3A to 3C illustrate a phosphor film forming step and an electrode enclosing step according to an example of the present invention. FIG. 3A illustrates a state of application of a phosphor suspension in the phosphor film forming step, and FIGS. 3B and 3C illustrate states before and after the enclosure of the glass mounts in the electrode enclosing step, respectively. FIG. 4 illustrates an amalgam enclosing step according to an example of the present invention. FIG. 5 is a perspective view illustrating an illumination device according to an example of the present invention. FIG. 6 is a partially cut-away plan view illustrating a ring-shape fluorescent lamp of Example 2 of the present invention. FIGS. 7A and 7B illustrate a glass bulb bending step according to an example of the present invention. FIG. 7A illustrates a state prior to the bending, while FIG. 7B illustrates a state after the bending. FIG. 8 is a graph showing the result of a lamp lighting test with respect to fluorescent lamps with L 2 /D=1.5×10 4 according to an example of the present invention. FIG. 9 is a graph showing the result of a lamp lighting test with respect to fluorescent lamps with L 2 /D=5×10 4 according to an example of the present invention. FIG. 10 is a graph showing the result of a lamp lighting test with respect to fluorescent lamps with L 2 /D=8.5×10 4 according to an example of the present invention. FIG. 11 is a graph showing the result of a vibration test of an example of the present invention. FIG. 12 is a graph showing a composition range of Example 4 of the present invention. DESCRIPTION OF THE INVENTION According to the present invention, when an amalgam pellet is put in the heated glass bulb, the amount of mercury vapor released from the amalgam pellet is greater than the amount of mercury vapor released from an amalgam pellet made of ZnHg, and therefore, the fluorescent lamp is less prone to an insufficient level of mercury vapor upon the first lighting of the fluorescent lamp, and therefore, less prone to lighting defects. In other words, it is possible to prevent the occurrence of flickering. Further, it is possible to reduce the weight of an amalgam pellet as compared with the case where SnHg is used, thereby preventing the phosphor film from being damaged or peeled by the amalgam pellet moving therein. It should be noted that the lighting defects of a fluorescent lamp are more apt to occur with increasing difficulty in spreading of mercury vapor throughout the glass bulb. The difficulty in spreading of mercury vapor is influenced by the internal diameter D and the discharge path length L of the glass bulb. In other words, the difficulty in spreading of mercury vapor is proportional to the volumetric capacity V of the glass bulb, and is inversely proportional to the conductance C (C=D 3 /L) of the glass bulb. Therefore, based on the following formula, hereinafter L 2 /D is used as an index representing the difficulty in the spreading of mercury vapor. Note that the inside of the glass bulb is regarded as a molecular flow region. V/C =π×( D/ 2) 2 ×L /( D 3 /L )=(π/4)×( L 2 /D ) The fluorescent lamp satisfies the relationship expressed as: 45×(1− A )≦ x≦ 55×(1 −A ), 75A≦y≦85A, 45−30 A≦z≦ 55−30 A , and x+y+z< 100, where A represents a value whose lower limit is determined as: A≧ 0.3−( S/ 25) and A≧ 0.1 when 0 <L 2 /D≦ 1.5×10 4 , A≧ 0.4−( S/ 25) and A≧ 0.2 when 1.5×10 4 <L 2 /D≦ 5×10 4 , or A≧ 0.5−( S/ 25) and A≧ 0.3 when 5×10 4 <L 2 /D≦ 8.5×10 4 . For making the amalgam pellet, a mixture of ZnHg and SnHg is used. Here, the foregoing value A represents a ratio of SnHg in a mixture obtained by mixing ZnHg and SnHg. Further, the above-mentioned (L 2 /D) is indicative of the thinness of the glass bulb. As the glass bulb is thinner, the difficulty in spreading of mercury vapor increases. In such a case, the value A is increased so that mercury vapor should be generated at a greater rate. The diameter D of the glass bulb may vary within a range of 10 mm≦D≦32 mm. A plurality of the amalgam pellets may be enclosed in the glass bulb, and each of the amalgam pellets may have a weight of not more than 15 mg. Further, the value of A preferably satisfies A<0.9. This provides an effect of reducing excessive leakage of Hg, thereby preventing a pellet from adhering to a thin tube of the fluorescent lamp when the pellet is brought into the fluorescent lamp through the tube. The amalgam pellet preferably is in an approximately spherical shape and has an average spherical diameter of not less than 0.3 mm and less than 3.0 mm. This reduces the tendency of the amalgam to adhere to a wall face of the discharge thin tube due to static electricity or the like upon the enclosure of the amalgam, and generally, a discharge thin tube with an internal diameter of about 3 mm is less prone to catching an amalgam pellet. Therefore, this allows the work of enclosing an amalgam pellet to be carried out stably. In the foregoing configuration, the spherical shape satisfies: S= 4π(( r max +r min )/2) 2 where r max represents a maximum diameter of a pellet in an unused state prior to the enclosure in the lamp, and r min is a minimum diameter of the same. The amalgam pellet preferably is made of Zn a Sn b Hg c , where a, b, and c are values in percent by weight satisfying 10≦a≦30, 30≦b≦65, and 25≦c≦45. In these ranges, the flickering upon the lighting can be prevented further, and the damaging or peeling of the phosphor film can be prevented. The foregoing amalgam pellet preferably is set so that the release of mercury begins when the temperature is above 260° C. In this range, the flickering upon the lighting can be prevented further. The foregoing amalgam pellet further may contain less than 10 percent by weight of at least one element selected from bismuth, lead, indium, cadmium, strontium, calcium, and barium. The foregoing component may be an unavoidable impurity, or may be added on purpose. This is because the working effect of the present invention can be maintained by so doing. An illumination device including the fluorescent lamp of the present invention is less prone to breakdowns due to non-lighting, etc., of the fluorescent lamp. Further, since mercury vapor is allowed to spread throughout the glass bulb in the fluorescent manufacturing process, the manufacturing method of the present invention allows a fluorescent lamp to be less prone to lighting defects that tend to occur due to an insufficient level of mercury vapor upon the first lighting of the lamp. EXAMPLES The following describes the present invention more specifically by way of examples. The present invention, however, is not limited to the examples shown below. Example 1 (1) Configuration of Fluorescent Lamp FIG. 1 is a partially cut-away plan view of a straight-shape fluorescent lamp according to one example. As shown in FIG. 1 , a fluorescent lamp 1 is a straight-shape fluorescent lamp exclusively for high frequencies (power consumption: 32 W), and includes a glass bulb 2 made of soda-lime glass. The glass bulb 2 has a tube internal diameter D of 23.5 mm and a discharge path length L of 1178 mm, whereby L 2 /D is 59050. On an internal face thereof, a protective layer and a phosphor film (not shown) are laminated successively, while an amalgam pellet 3 for supplying mercury vapor and argon gas as rare gas are enclosed therein. Glass mounts 5 having electrodes 4 , respectively, are fixed in both ends of the glass bulb 2 so as to be enclosed in the bulb, and the ends of the glass bulb 2 are capped with bases 6 , respectively. The amalgam pellet 3 is in an approximately spherical shape, having an average spherical diameter of 1.2 mm, a weight of 11.5 mg (the mercury content of the same is 3 mg), and a surface area S of 4.5 mm 2 . One amalgam pellet 3 is enclosed in the glass bulb 2 . The amalgam pellet 3 is made of an amalgam containing zinc, tin, and mercury as principal components (this amalgam is hereinafter referred to as ZnSnHg), and the above described value A, value x (value a), value y (value b), and value z (value c) satisfy A=0.8, x=10 (a=10), y=64 (b=64), and z=26 (C=26), respectively. (2) Fluorescent Lamp Manufacturing Method Next, a method for manufacturing the fluorescent lamp according to the above-described Example 1 is described, with reference to FIGS. 2 to 5 . The method for manufacturing a fluorescent lamp includes a mount assembling step, a phosphor film forming step, an electrode enclosing step, an air discharging step, an amalgam enclosing step, and a rare gas enclosing step. First, the glass mounts 5 are assembled in the mount assembling step. FIGS. 2A and 2B illustrate the mount assembling step. FIG. 2A shows members composing the glass mount, and FIG. 2B shows the glass mount obtained after assembling. As shown in FIG. 2A , the glass mount 5 is composed of a discharge thin tube 7 , a flare 8 , a pair of lead lines 9 , and a coil 10 , and they are assembled integrally as shown in FIG. 2B . It should be noted that each of the foregoing electrodes 4 is composed of a pair of the lead lines 9 and the coil 10 . The phosphor film forming step is carried out in parallel with the mount assembling step. FIGS. 3A to 3C illustrate the phosphor film forming step and the electrode enclosing step. FIG. 3A illustrates a state of applying a phosphor suspension in the phosphor film forming step, and FIGS. 3B and 3C illustrate states before and after the enclosure of the glass mounts in the electrode enclosing step, respectively. In the phosphor film forming step, a protective film is formed on the internal face of the straight-shape glass bulb 2 preliminarily. Then, as shown in FIG. 3A , the phosphor suspension 11 containing a phosphor emitting three wavelengths is poured into the glass bulb 2 , and the internal face of the glass bulb is wetted by the phosphor suspension 11 . Next, the phosphor suspension 11 is dried, and baked in a furnace for approximately one minute at 550° C. to 660° C., whereby a phosphor film is formed. In the electrode enclosing step, after the phosphor film is removed partially in the vicinities of the both ends of the glass bulb 2 , as shown in FIG. 3B , glass mounts 5 a and 5 b are inserted to the both ends, respectively, and are fixed therein at positions as shown in FIG. 3C so as to be enclosed in the bulb. It should be noted that in the manufacturing method according to the present example, a method for discharging air from only one end of the glass bulb 2 is employed, and a tip of a discharge thin tube (not shown) of the glass mount 5 b on the other side has been cut by burning preliminarily so as to be sealed, whereby one side of the glass bulb 2 is in a sealed state. In the air discharging step, an impurity gas in the glass bulb 2 is discharged through the non-sealed discharge thin tube 7 . In the amalgam enclosing step, the amalgam pellet 3 is enclosed in the glass bulb 2 . FIG. 4 illustrates the amalgam enclosing step. The amalgam pellet 3 is dropped from an amalgam dropping device 12 through the non-sealed discharge thin tube 7 into the glass bulb 2 . Here, if an average spherical diameter of the amalgam pellet 3 is set to be not less than 0.3 mm, the amalgam 3 has less tendency to adhere to a wall of the discharge thin tube 7 . On the other hand, when the average spherical diameter of the amalgam pellet 3 is set to be less than 3.0 mm, the amalgam pellet 3 has less tendency to lodge in the discharge thin tube 7 . It should be noted that the manufacturing method of the present invention does not employ a costly method such as a method of fixing the amalgam pellet 3 onto a tube end portion of the glass bulb 2 or a method of sealing the amalgam pellet 3 inside the discharge thin tube 7 , but the amalgam pellet 3 is enclosed in the glass bulb 2 in a manner such that the amalgam pellet 3 is freely movable therein. In the amalgam enclosing step, it is desirable to maintain the temperature in the glass bulb 2 to 260° C. or above so as to accelerate the release of mercury vapor from the amalgam pellet 3 . This is because, as will be described later, the temperature at which the release of vapor of mercury contained in the amalgam pellet 3 starts is 260° C. In the rare gas enclosing step, argon gas is enclosed in the glass bulb 2 via the discharge thin tube 7 at a pressure of 280 Pa, and after the enclosure, the tip of the discharge thin tube 7 is burnt so as to be cut and sealed. Finally, the bases 6 are attached to the both ends of the glass bulb 2 , respectively, whereby the fluorescent lamp 1 is completed. (3) Configuration of Illumination Device The fluorescent lamp according to Example 1 can be used as a light source of an illumination device. FIG. 5 is a perspective view illustrating an illumination device. As shown in FIG. 5 , an illumination device 13 according to the present example includes the fluorescent lamp 1 according to Example 1 as the light source. The fluorescent lamp 1 is housed in a device main body 14 , and is controlled by a lighting means 15 attached to a top face of the device main body 14 . Example 2 (1) Configuration of Fluorescent Lamp FIG. 6 is a partially cut-away plan view illustrating a ring-shape fluorescent lamp of Example 2 of the present invention. As shown in FIG. 6 , a fluorescent lamp 21 is a ring-shape fluorescent lamp (power consumption: 40 W) including a glass bulb 22 made of soda-lime glass. The glass bulb 22 has a tube internal diameter D of 27 mm and a discharge path length L of 1026 mm, whereby L 2 /D is 38988. On an internal face thereof, a protective layer and a phosphor film (not shown) are laminated successively, while an amalgam pellet 23 for supplying mercury vapor and argon gas as rare gas are enclosed therein. Glass mounts 25 having electrodes 24 , respectively, are fixed in both ends of the glass bulb 22 so as to be enclosed in the bulb, and a base 26 is attached to the ends of the glass bulb 22 so as to cover the same. The amalgam pellet 23 is in an approximately spherical shape, having an average spherical diameter of 1.3 mm, a weight of 13.2 mg (the mercury content out of the same is 5 mg), and a surface area S of 5.3 mm 2 . One of the amalgam pellet 23 is enclosed in the glass bulb 22 . The amalgam pellet 23 is made of ZnSnHg, and the above described value A, value x (value a), value y (value b), and value z (value c) satisfy A=0.4, x=30 (a=30), y=32 (b=32), and z=38 (c=38), respectively. It should be noted that the fluorescent lamp 21 according to Example 2 could be used as a light source of an illumination device, as is the case with the fluorescent lamp 1 according to Example 1. (2) Fluorescent Lamp Manufacturing Method Next, a method for manufacturing the fluorescent lamp according to the above-described Example 2 is described. The method for manufacturing a fluorescent lamp includes a mount assembling step, a phosphor film forming step, an electrode enclosing step, a glass bulb bending step, an air discharging step, an amalgam enclosing step, and a rare gas enclosing step. These steps except for the glass bulb bending step are identical to the steps according to the above-described Example 1. It should be noted that in the manufacturing method according to Example 2 as well, as is the case with the manufacturing method according to Example 1, the temperature in the glass bulb 22 desirably is maintained at 260° C. or above in the amalgam enclosing step. The manufacturing method for manufacturing the fluorescent lamp according to Example 2 is different from the manufacturing method for manufacturing the fluorescent lamp according to Example 1 in that the former method includes the glass bulb bending step. The glass bulb bending step is carried out after the completion of the electrode enclosing step and prior to the air discharging step. In the glass bulb bending step, the straight-shape glass bulb 22 is subjected to bending so as to have a ring shape. FIGS. 7A and 7B illustrate the glass bulb bending step. FIG. 7A illustrates a state prior to the bending, while FIG. 7B illustrates a state after the bending. The straight-shape glass bulb 22 as shown in FIG. 7A is brought into a furnace in which the atmosphere temperature is controlled at around 700° C. to 900° C., and is formed into a ring-shape glass bulb 22 as shown in FIG. 7B . (3) Amount of Mercury Released from Amalgam Pellet ZnHg is an amalgam principally composed of Zn 3 Hg, and considering the phase diagram, the temperature at which mercury vapor starts to be released is 42.9° C. On the other hand, SnHg is an amalgam principally composed of Sn 20 Hg 3 , Sn 7 Hg, and Sn 6 Hg, and the temperature at which mercury vapor starts to be released is in the vicinity of 58° C. Therefore, at the temperature while the lamp is being turned on, it is presumed that an amount of released mercury from ZnHg is greater than that from SnHg. However, since the amalgam enclosing step is carried out after the electrode enclosing step or the glass bulb bending step as described above, the temperature inside the glass bulb is 200° C. to 300° C. at the time when the amalgam pellet is enclosed. Therefore, the time when mercury vapor is released from the amalgam pellet at the highest rate is the time when the amalgam pellet is enclosed, that is, the time when the amalgam pellet is subjected to the highest temperature. Therefore, it can be considered that the amount of mercury vapor released from the amalgam pellet in the foregoing temperature range of 200° C. to 300° C. has the greatest effect on the mercury vapor pressure upon the first lighting of the lamp. Then, respective amounts of released mercury vapor in the cases of ZnHg and SnHg in the foregoing temperature range were determined. More specifically, the amalgams were brought into chambers under atmospheric pressure, heated to 200° C. to 300° C. for about 10 minutes, and amounts of mercury having been released therefrom at predetermined temperatures in the foregoing temperature range were determined. Table 1 shows amounts of mercury released from amalgams. TABLE 1 Initial Mercury Composition Content Amount of Released Mercury (wt %) (mg) 240° C. 260° C. 280° C. 300° C. ZnHg (50:50) 5.0 0 mg (0%)   0 mg (0%) 0.1 mg (2%) 0.3 mg (6%)  SnHg (80:20) 3.0 0.1 mg (3%)   0.2 mg (7%)  0.4 mg (13%) 0.6 mg (20%) ZnSnHg (25:40:35) 4.6 0 mg (0%) 0.2 mg (4%) 0.3 mg (7%) 0.5 mg (11%) As shown in Table 1, the temperature at which ZnHg starts releasing mercury is in the vicinity of 280° C., while the temperature at which SnHg starts releasing mercury is in the vicinity of 240° C. Besides, when the temperature reaches 300° C., the amount of mercury having been released from ZnHg is 6%, while the amount of mercury having been released from SnHg is 20%. Therefore, in the foregoing temperature range, that is, the amount of mercury released in the temperature range, which has the greatest influence on the first lighting of the fluorescent lamp, is greater in the case of SnHg than in the case of ZnHg. It should be noted that an amount of mercury released from an amalgam obtained by mixing ZnHg and SnHg (hereinafter referred to as ZnSnHg) is greater than that of ZnHg and smaller than that of SnHg in the foregoing temperature range. (4) Experiments As described above, a fluorescent lamp in which ZnHg is enclosed has a drawback in that due to a small amount of released mercury, flickering tends to occur, whereas a fluorescent lamp in which SnHg is enclosed has a drawback in that due to an increased weight of the amalgam pellet, the phosphor film tends to peel off. Therefore, fluorescent lamps were manufactured by using various ZnSnHg compositions obtained by mixing ZnHg and SnHg, and the frequencies of occurrence of lighting defects and film peeling were determined with respect to the foregoing fluorescent lamps. By so doing, conditions for manufacturing a fluorescent lamp that has none of the foregoing problems were analyzed. 1. Lighting Defects A lighting test was carried out so as to determine the frequency of occurrence of lighting defects. In the lighting test, each fluorescent lamp was attached to a lighting device and was turned on, and whether or not a lighting defect such as non-lighting or flickering occurred was checked visually. It should be noted that the lighting defect of a fluorescent lamp is more apt to occur with increased difficulty in spreading of mercury vapor throughout the glass bulb. The difficulty in spreading of mercury vapor is influenced by the internal diameter D and the discharge path length L of the glass bulb. In other words, the difficulty in spreading of mercury vapor is proportional to the volumetric capacity V of the glass bulb, and is inversely proportional to the conductance C (C=D 3 /L) of the glass bulb. Therefore, based on the following formula, hereinafter L 2 /D is used as an index representing the difficulty in spreading of mercury vapor. Note that the inside of the glass bulb is regarded as a molecular flow region. V/C =π×( D/ 2) 2 ×L /( D 3 /L )=(π/4)×( L 2 /D ) Experiments were carried out with respect to three types of ring-shape fluorescent lamps having different internal diameters D and different discharge path lengths L of glass bulbs, respectively. FIG. 8 is a graph showing the result of a lamp lighting test with respect to fluorescent lamps (L=475, D=15) with L 2 /D=1.5×10 4 , FIG. 9 is a graph showing the result of a lamp lighting test with respect to fluorescent lamps (L=840, D=14) with L 2 /D=5×10 4 , and FIG. 10 is a graph showing the result of a lamp lighting test with respect to fluorescent lamps (L=1475, D=25.5) with L 2 /D=8.5×10 4 . In each graph, “o” indicates that a lighting defect occurred with none of 50 lamps subjected to the test, “Δ” indicates that lighting defects occurred with one or two of the same, and “x” indicates that lighting defects occurred with three or more of the same. Besides, in each graph, a hatched range indicates the range of conditions under which no lighting defect occurred. The result shown in FIG. 8 can be interpreted to indicate that a fluorescent lamp satisfying 0<L 2 /D≦1.5×10 4 is less prone to a lighting defect, provided that in the fluorescent lamp an amalgam pellet is enclosed that satisfies the following relationship: 45×(1− A )≦ x≦ 55×(1− A ), 75A≦y≦85A, 45−30 A≦z≦ 55−30 A , and x+y+z≦ 100, where the lower limit of the value A is determined as follows: A≧0.3 when 0.2<S<2.5, A≧0.2 when 2.5≧S<5.0, and A≧0.1 when 5.0≦S. It should be noted that a solid line in the graph of FIG. 8 is an approximate line (A=0.3−0.04×S) indicating the lower limit of the value A presumed from the experiment result. Further, the result shown in FIG. 9 indicates that in the case of a fluorescent lamp satisfying 1.5×10 4 <L 2 /D≦5×10 4 , the lower limit of the value A is determined as: A≧0.4 when 0.2≦S<2.5, A≧0.3 when 2.5≦S<5.0, and A≧0.2 when 5.0≦S. It should be noted that a solid line in the graph of FIG. 9 is an approximate line (A=0.4−0.04×S) indicating the lower limit of the value A presumed from the experiment result. Further, the result shown in FIG. 10 indicates that in the case of a fluorescent lamp satisfying 5×10 4 <L 2 /D≦8.5×10 4 , the lower limit of the value A is determined as: A≧0.5 when 0.2≦S<2.5, A≧0.4 when 2.5≦S<5.0, and A≧0.3 when 5.0≦S. It should be noted that a solid line in the graph of FIG. 10 is an approximate line (A=0.5−0.04×S) indicating the lower limit of the value A presumed from the experiment result. 2. Regarding Film Pealing A vibration test was carried out so as to analyze the influence of the weight of an amalgam on the peeling of a phosphor film. The vibration test was carried out by vibrating a fixed fluorescent lamp under predetermined conditions (vibration acceleration: ±1.0 G, frequency range: 5 Hz to 50 Hz, sweeping method: logarithmic sweeping at ½ octave/min, repetition cycle: 798 sec), and it was checked visually whether or not film peeling occurred in the phosphor film. It has been proved that if film peeling did not occur after 27 minutes of vibration in the foregoing vibration test, an inconvenience due to film peeling should not occur in actual transportation. FIG. 11 is a graph showing the result of a vibration test. In the graph of FIG. 11 , “o” indicates that no film peeling occurred, and “x” indicates that film peeling occurred. Further, in the graph shown in FIG. 11 , a hatched range is the range of conditions under which no film peeling occurred. In the case where the weight of the amalgam pellet was 20 mg, no film peeling occurred even with vibration being applied for 27 minutes in a predetermined vibration test. Therefore, it can be concluded that in the case where one amalgam pellet is enclosed, no film peeling will occur if the weight of the amalgam pellet is set to be not more than 20 mg. In the case where the weight of the amalgam pellet was 15 mg, no film peeling occurred even with vibration being applied for 54 minutes in a predetermined vibration test, and hence, it was determined that no film peeling would occur under approximate conditions such that two or more of 15-mg amalgam pellets are enclosed and vibration is applied for 27 minutes in the predetermined vibration test. Thus, it can be concluded that in the case where two or more amalgam pellets are enclosed, no film peeling will occur if the weight of each amalgam pellet is set to be not more than 15 mg. 3. Evaluation of Performances of Fluorescent Lamps Fluorescent lamps of Examples 1 and 2 were subjected to the lighting test and vibration test so that performances of lamps were evaluated. Flickering was checked visually, but it also can be determined by comparing the light start-up performances of the foregoing fluorescent lamps with that of a fluorescent lamp in which liquid mercury is enclosed. The fluorescent lamp in which liquid mercury is enclosed exhibits an excellent light start-up performance. Let a time it takes to reach 80% of the light stabilized after the lighting of the fluorescent lamp in which liquid mercury is enclosed be T 0 , and let a time it takes to do so in the case of the fluorescent lamp in which a mercury amalgam pellet is used be T 1 . Here, the relationship of T 1 >T 0 ×1.5 is satisfied when flickering occurs to the fluorescent lamp in which a mercury amalgam pellet is used. In other words, flickering occurs in the case where the light start-up time of the fluorescent lamp in which a mercury amalgam pellet is used exceeds 1.5 times the light start-up time of the fluorescent lamp in which liquid mercury is used. This flickering can be checked visually. Table 2 shows evaluation results regarding the fluorescent lamps according to Example 1. As a comparative example, fluorescent lamps in which ZnHg was enclosed were used. The fluorescent lamps of the comparative example were designed to the same specifications as those of the fluorescent lamps according to Example 1 except for the amalgam pellets being made of ZnHg, which was the only difference from the fluorescent lamps of Example 1. It should be noted that all the amalgam pellets enclosed in the fluorescent lamps were prepared so that the mercury amount contained in each was set to be 3 mg. TABLE 2 Number of flickering Number of lamps or defective lamps with film peeling Composition (among 50 lamps) (among 20 lamps) ZnSnHg (Example 1) 0 0 ZnHg (Comparative Example) 3 0 As shown in Table 2, while no lighting defect or film peeling occurred with the fluorescent lamps 1 in which ZnSnHg was enclosed, lighting defects occurred with three of the fluorescent lamps in which ZnHg was enclosed. Table 3 shows evaluation results regarding the fluorescent lamps according to Example 2. As a comparative example, fluorescent lamps in which ZnHg or SnHg was enclosed were used. The fluorescent lamps of the comparative example were designed to the same specifications as those of the fluorescent lamps according to Example 2 except for the amalgam pellets being made of ZnHg or SnHg, which was the only difference from the fluorescent lamps of Example 2. It should be noted that all the amalgam pellets enclosed in the fluorescent lamps were prepared so that the mercury amount contained in each was set to be 5 mg. TABLE 3 Number of Number of Enclosed flickering or lamps with amount defective lamps film peeling Composition (mg) (among 50 lamps) (among 20 lamps) ZnSnHg (Example 2) 14 0 0 ZnHg (Comparative 10 3 0 Example) SnHg (Comparative 25 0 6 Example) As shown in Table 3, while no lighting defect or film peeling occurred with the fluorescent lamps 21 in which ZnSnHg was enclosed, lighting defects occurred with three of the fluorescent lamps in which ZnHg was enclosed, and film peeling occurred to six of the fluorescent lamps in which SnHg was enclosed. The above-described results indicate that the fluorescent lamps 1 according to Example 1 and the fluorescent lamps 21 according to Example 2 were less prone to lighting defects and film peeling, as compared with the conventional fluorescent lamps. It should be noted that the same performance can be achieved from a fluorescent lamp other than the foregoing fluorescent lamps 1 and 21 as long as it is a fluorescent lamp according to the present invention. Example 3 Fluorescent lamps according to Example 1 were prepared, in which amalgam pellets shown in Table 4 were enclosed, respectively, and the number of fluorescent lamps in which mercury adhered to the thin tubes was determined. The result is shown in Table 4 below. TABLE 4 Number of lamps with mercury adhesion to Value A ZnHg mixture Hg amount thin tubes (SnHg mixture ratio) ratio (mg) (among 10 lamps) 0.5 0.5 5 0 0.8 0.2 5 0 0.9 0.1 5 1 1.0 0 5 4 Table 4 shows that regarding the adhesion of mercury to the thin tube, a preferable result was obtained when A<0.9. Example 4 Fluorescent lamps according to Example 1 were prepared, in which amalgam pellets shown in Table 5 were enclosed, respectively, and the number of flickering fluorescent lamps, the number of fluorescent lamps in which film peeling occurred, and the number of fluorescent lamps in which mercury adhered to the thin tubes, were determined. The result is shown in Table 5 below. It should be noted that the evaluation was made in the same manner as those described regarding Examples 1 to 3. The composition range of the present example is shown in the graph of FIG. 12 . A hatched region in FIG. 12 is a range of compositions regarded as excellent as a result of the overall evaluation shown in Table 5, and numerals in brackets shown in the graph correspond to the numerals of the notes for Table 5. TABLE 5 Result Condition Tackiness Weight Total (Adhesion Experiment Zn Sn Hg of Hg weight Film to thin Overall No. (wt %) (wt %) (wt %) (mg) (mg) Flickering peeling tube) evaluation 1 25 25 50 5 10.0 ∘ ∘ x (1) x 2 25 30 45 5 11.1 ∘ ∘ ∘ ∘ 3 25 40 35 5 14.3 ∘ ∘ ∘ ∘ 4 25 50 25 5 20.0 ∘ ∘ ∘ ∘ 5 25 55 20 5 25.0 x (2) ∘ ∘ x 6 10 40 50 5 10.0 ∘ ∘ x (3) x 7 15 40 45 5 11.1 ∘ ∘ ∘ ∘ 8 20 40 40 5 12.5 ∘ ∘ ∘ ∘ 9 30 40 30 5 16.7 ∘ ∘ ∘ ∘ 10 35 40 25 5 20.0 x (4) ∘ ∘ x 11 5 60 35 5 14.3 ∘ ∘ x (5) x 12 10 55 35 5 14.3 ∘ ∘ ∘ ∘ 13 20 45 35 5 14.3 ∘ ∘ ∘ ∘ 14 30 35 35 5 14.3 ∘ ∘ ∘ ∘ 15 35 30 35 5 14.3 x (6) ∘ ∘ x Note (1),(3) As the Hg content was in excess of the appropriate ratio, Hg leaked, thereby causing tackiness to occur. Note (2) As Sn was increased while Hg was decreased as compared with the appropriate ratio, an amount of Hg released in an initial stage was small, thereby causing flickering to occur. Note (4) As Zn was increased while Hg was decreased as compared with the appropriate ratio, an amount of Hg released in an initial stage was small, thereby causing flickering to occur. Note (5) As Zn was decreased while Sn was increased as compared with the appropriate ratio, Hg leaked, thereby causing tackiness to occur. Note (6) As Zn was increased while Sn was decreased as compared with the appropriate ratio, an amount of Hg released in an initial stage was small, thereby causing flickering to occur. As clear from Table 4, the compositions in the range of the present invention caused none of flickering, film peeling, and tackiness, and exhibited excellent overall evaluation results. INDUSTRIAL APPLICABILITY Fluorescent lamps according to the present invention are applicable as mercury discharge lamps in which mercury is used.

A fluorescent lamp is configured so that a glass bulb has a phosphor film formed on its internal face, and a rare gas and an amalgam pellet are enclosed therein. The amalgam pellet contains zinc, tin, and mercury as principal components, one amalgam pellet is enclosed in the glass bulb, and the amalgam pellet has a weight of not more than 20 mg. The fluorescent lamp satisfies the relationship expressed as: 45×(1−A)≦x≦55×(1−A), 75A≦y≦85A, 45−30A≦z≦55−30A, and x+y+z≦100, where x represents a content of zinc contained in the amalgam pellet in percent by weight, y represents a content of tin therein in percent by weight, and z represents a content of mercury therein in percent by weight. This configuration allows the fluorescent lamp to be characterized in that an amount of released mercury that is necessary for the first lighting of the fluorescent lamp is secured, and that the phosphor film is less prone to being peeled due to the amalgam.

This application claims the benefit of U.S. Provisional Application Ser. No. 60/467,456 filed May 2, 2003 and U.S. Provisional Application Ser. No. 60/497,300 filed Aug. 22, 2003, the teachings of all are incorporated herein by reference. FIELD OF INVENTION The present invention relates to devices, systems and methods for measuring bioimpedance, more specifically bioimpedance of the human cervix and the present invention also relates to methods that embody such measuring methods for diagnosis, examination and treatment of tissue and/or organs, more specifically the human cervix and tissue of the human cervix. BACKGROUND OF THE INVENTION Pre-term labor or pre-term birth is a significant problem that costs billions of health care dollars annually. An infant is considered pre-term if born before thirty-seven weeks of gestation. Of the estimated 6,250,000 pregnancies that occur in the U.S. each year, about 11% are pre-term births. Obstetrics - Normal and Problem Pregnancies, 4th ed., Copyright® 2002 Churchill Livingstone, Inc. p. 755-763; http://www.wvdhr.org/bph/hp2010/objective/16.htm, May 14, 2003. The use of reproductive technology, the increasing number of pregnancies for women over age of thirty-five, and the growing incidence of multiple births potentially can lead to future increases in this percentage. Furthermore, about 80% of the pre-term births occur spontaneously, while the remainder are induced in response to complications discovered with the fetus or mother. Mattison, D. R.; et al., Pre - term Delivery: a public health perspective , Paediatric and Perinatal Epidemology 2001, 15 (Supple. 2), 7-16. Infants born pre-term are considerably less physiologically developed than normal term infants. Consequently and as illustrated in FIGS. 1 A,B, especially high rates of acute newborn morbidity and mortality are associated with such infants, especially those born extremely pre-term (e.g., 23-27 weeks). These pre-term neonates also face greater risks for long term health problems than infants born full term. Such health problems include underdeveloped respiratory systems, complications to the nervous system, problems feeding, mental retardation, and intraventricular (brain) hemorrhage. Confronting Pre - term Delivery in the 21 st Century: From Molecular Intervention to Community Action http://www.medscape.com/viewaarticle/408935. About 60% of all serious prenatal complications or deaths that occur are due to pre-term delivery. Further, pre-term birth also has been associated with several maternal complications including infection due to pre-term rupture of the membrane (PROM) and postpartum depression. The most significant source of maternal risk is associated with the higher rates of caesarean delivery. Premature delivery complicates the level of surgery required which increases the possibility of hemorrhage, thromboembolism and infection. Pre-term births result not only in high medical risks but also result in higher medical costs, where the major medical costs are typically incurred after delivery. These pre-term newborn infants usually require a much longer hospital stay (e.g., the average hospital stay pf a pre-term infant is 21.7 days) and more expensive treatments than a normal term baby. Such treatments include incubation, respiratory assistance and dialysis. It has been reported that the cost for the care of premature infants is over six billion dollars annually, where about seventy five percent of this value is spent in the first year of life, mostly on the initial hospitalization. Studies to quantify such expenditures also show an inverse correlation between mean cost per surviving infant and the gestational age. As illustration, while a healthy pregnancy costs on average $6,400, the medical costs associated with a pre-term baby can cost $20,000 to $1 million, where the mean cost per infant for infants born between weeks 26-28 is about $49,000. There are many conditions that may result in pre-term delivery. These include: genetic predisposition, maternal or fetal stress or infection, premature rupture of the amniotic membrane, abnormal hormonal signals, and abnormal uterine properties. Regardless of cause, the softening, dilation, and effacement of the cervix during pregnancy and labor do not occur as a result of uterine contractions alone, but are also a result of an active remodeling of the structure of the cervix. Pre-term labor is often a result of improper timing of the normal signals that trigger cervical remodeling, and pre-term softening of the cervical tissue can result in spontaneous abortion, pre-term delivery, and sometimes impairs normal vaginal delivery. Regardless of the point during gestation that hormonal signals to remodel arrive, it is believed that they trigger similar changes in the cervix. In the transition to labor, the tissue of the human pregnant cervix undergoes significant remodeling, such that its predominantly collagen matrix is replaced by glycosaminoglycans. As a result of this “ripening,” the cervix softens, thereby preparing for the thinning and dilation that will ultimately be required to allow the fetus to exit the womb. If detected early enough, there are several treatments that may be very effective in delaying labor until an acceptable gestational age and level of fetal development occurs. These treatments vary from something as simple as bed rest to drugs that can be administered in an effort to postpone labor or arrest its progression. Such drugs include, but are not limited to beta-adrenergic receptor agonists, magnesium sulfate, calcium channel blockers, cyclooxygenase inhibitors, salbumatol, lidocaine and nitric oxide/nitric oxide donors. Corticosteriods also are frequently employed as a specific treatment to the premature fetus to enhance organ maturation as well as improving fetal lung function by speeding development of the lungs and respiratory enzymes necessary for oxygen transfer. These also may decrease the risk of intraventricualar hemorrhage and injury to the gastrointestinal tract. These treatments are more likely to be effective and safe if the onset of pre-term labor is caught early in the gestation period. Accurate and early diagnosis of pre-term labor is a major problem as up to about 50% of patients being diagnosed with pre-term labor do not actually have pre-term labor and yet as many as 20% of symptomatic patients diagnosed as not being in labor will deliver prematurely. Such misdiagnosis is problematic because, as indicated herein, intervention early in the gestation period is more advantageous to effectively prevent pre-term delivery. Currently, a physician weighs the importance of several parameters such as patient history, biochemical test results, and examination of the cervix, to predict the onset of pre-term labor. For example, a patient history significant for certain obstetrical conditions, such as cervical incompetence, infections of the amniotic fluid, previous abortion or prior pre-term delivery has been shown to increase the risk of pre-term labor in an index or subsequent pregnancy. The most reliable method of labor prediction involves the obstetrician to digitally palpitating (using his/her finger(s)) the cervix to evaluate its softness. Such examinations can be conducted in 1 to 2 hour intervals until the obstetrician is satisfied that progressive change in the consistency, position, dilation and effacement of the cervix is or is not occurring. This method, in addition to being dependent upon the experience of the obstetrician, is qualitative in nature and therefore large changes in cervical consistency must occur before a changes able to be felt. Obstetricians also can use ultrasound technology to determine the position of the fetus and the length of the cervix, but his data alone is not sufficient to predict whether delivery will occur. The current absence of diagnostic methods that have acceptable rates of sensitivity and specificity has prompted researchers and others to look for other ways to predict pre-term labor earlier. Many of these methods are based on qualitatively measuring the physical changes, as opposed to biochemical ones, that have been discovered to occur in a cervix of a pregnant woman. More advanced diagnostic methods including transabdominal electromyography (EMG) and transvaginal ultrasound (TVS) do exist and have been shown to slightly increase diagnostic accuracy. Cervical length and force of muscle contractions are examples of how TVS and transabdominal EMG measure physical changes. TVS measures the cervical length using ultrasound wave resonance, which may reflect cervical incompetence. Unfortunately this method does have a number of disadvantages including uncertainty related to the lack of a standard cervical measurement to judge against and variations in cervical length due to filing of the bladder. Another technology that has been used to detect pre-term labor is transabdominal EMG that essentially involves measuring the voltage produced by uterine contractions. The main disadvantage concerning the use of this technique is that childbirth specific uterine contractions tend to occur relatively close to the time of actual delivery (e.g., about 4 days in advance). This, as a practical matter, is much to short for any preventive treatment to have a significant effect on the mother. Despite the foregoing, it also should be recognized that despite about two decades of improvement in regards to neonatal care, the rate of pre-term birth over that time has not been reduced and has remained essentially at a annual rate of about 11%. Although many reasons for this abound, a significant issue as referred to herein is that by the time the onset of premature labor is recognized clinically, little is available to arrest the process. As such, it is desirous to be able to detect the onset of premature labor well it would become clinically apparent using conventional techniques. This would allow medical intervention to occur earlier in the gestation period than is possible presently and can increase the likelihood that such medical intervention can be more successful in delaying or preventing pre-term delivery as compared to what is possible using existing techniques. Recently, the focus of a number of studies has been on using biochemical markers as indicators or pre-term labor. Certain concentrations of compounds, such as fetal fibronectin, placental protein, prolactin and estriol found in the serum or vaginal fluid/secretions of the mother would indicate a risk of pre-term delivery. These methods, are still highly experimental and also do not indicate with any certainty whether or not a particular patient will actually deliver pre-term. In addition to early detection of pre-term labor, it also is desirous to assess the degree of cervical remodeling that can be used to determine the readiness or ripeness of the cervix for labor in general. This determination has important implications for choosing the method for inducing labor when indications to do so develop during the course of a complicated pregnancy. In addition, in the current age of cost containment, it also would be advantageous to have a mechanism by which one can more accurately predict the onset of labor even for pregnancies that go to normal term. This would allow for better planning and staffing of labor and delivery hospital units because anticipated volume of births could be more accurately predicted. As a non-obstetrical application, it has been suggested that electrical impedance spectra of tissues, more specifically cervical tissue, might be useable as a screening technique for the detection of cervical precancers and more specifically a screening technique whereby there is good separation between normal and precancerous tissues. Brown et al., Relation between tissue structure and imposed electrical current flow in certain neoplasia , Lancet 2000, 335: 892-895. In the described technique a pencil probe with four flush mounted gold electrodes (i.e., mounted flush to face of the probe) was used to measure electrical impedance spectra from eight points on the cervix. The method and apparatus reported, however, was developed to determine the efficacy of the concept and thus are generally experimental in nature. A comparative study of pregnant cervix and non-pregnant cervix using electrical impedance measurements also has been reported. O'Connel, M P; et al; An in vivo comparative study of the pregnant and non - pregnant cervix using bioelectrical impedance measurements , British Journal of Obstetrics and Gynecology, August 2000, Vol. 107, p. 1040-1041. The article postulates that the electrical impedance techniques could be used to characterize the changes in cervical hydration that precedes labor. The article also postulates that this may be of clinical value in the prediction of labor onset both term and pre-term. In the described technique a pencil probe with four flush mounted gold electrodes (i.e., mounted flush to face of the probe) was used to measure electrical impedance spectra of the cervix. The study observed a resistivity difference between the tissues of the cervix of women in the delivery suite at the time of induction of labor prior to any intervention and the tissues of the cervix of non-pregnant women. The method and apparatus reported, however, was developed to determine the efficacy of the general concept that there was a noticeable difference between the electrical impedance measured for cervical tissues of women in the later stages of pregnancy and women that are not pregnant As to other described postulated clinical uses, the article merely postulates or suggests that electrical impedance might be useable for such uses but does not include a demonstration or disclosure of the use of a bioimpedance measurement technique for the other suggested and described clinical uses. It thus would be desirable to provide non-invasive devices, apparatuses, systems and methods that allow a clinician or obstetrician to directly measure the electrical impedance of the cervical tissue of a patient so as to allow the clinician to assess the cervical tissue for obstetrical or non-obstetrical related diagnosis/examination. It would be particularly desirable to provide such a device apparatus, system and method that would allow a clinician to make a determination of the onset of pre term labor earlier in gestation as compared to prior art devices and/or techniques. It also would be desirable to provide systems embodying such devices and apparatuses whereby the measurements can be evaluated so further clinical information (e.g., an out of norm condition indication) is provided by the system to assist the clinician/diagnostician with the examination or diagnosis of a given patient. Such devices, apparatuses and systems preferably would be simple in construction and easy to use by the clinician, diagnostician, or obstetrician. Such devices, apparatuses and methods also preferably would have the beneficial effect of reducing the risk of neonatal mortality from pre-maturity, reducing the risk and/or amount of medical treatment needed for the pre-term infant, and reducing maternal risk. Such devices, apparatuses and methods also preferably would have the beneficial effect of reducing misdiagnosis particularly when compared with what occurs with the use of conventional obstetrical techniques for assessing cervical tissues and/or the risk for onset of pre-term delivery. Such devices, apparatuses, systems and methods also preferably are easily adaptable for use in combination with existing techniques and methods to assess the cervical tissues for non-obstetrical purposes so as to reduce the need to use invasive techniques for assessing cervical tissue (e.g., minimizing cervical bioposies). SUMMARY OF THE INVENTION The present invention features devices and apparatuses for measuring bioimpedance of tissues of the cervix, more specifically the mammalian cervix. Also featured are methods related thereto, more specifically methods for examining the tissues of the cervix for clinical or diagnostic purposes such as during routine gynecological examinations to determine early onset of labor in pregnant patients or to assess such tissues for the presence of abnormalities such as cancerous lesions in both pregnant and non-pregnant women. Also featured are methods for treating onset of early or pre-term labor or delivery, which methods embody such devices, apparatuses and methods of the present invention. Also featured are systems embodying such devices, apparatuses and/or methods of the present invention. Such systems preferably are configured and arranged so as to provide diagnostic and/or clinical information to further assist the diagnostician or clinician in diagnosing and/or examining pregnant or non-pregnant patients. Such diagnostic/clinical information is generated based on the bioimpedance measurements taken using such devices and apparatuses of the present invention and in more specific embodiments, is generated based on comparisons of the measured data with developed sets of data representing any one of a number of possible conditions of the cervical tissues being examined. Such devices, apparatus, systems and methods, including embodiments and aspects thereof, are discussed and described herein. In its broadest aspects, the bioimpedance measuring apparatus of the present invention includes a bioimpedance measuring device and a signal generating/sensing device being operably coupled to the bioimpedance measuring device. The bioimpedance measuring device includes a tip member that is configured and arranged so as to include a plurality or more of electrodes at least an end of each being exposed so as to contact and be put into electrical contact with the cervical tissues. The bioimepdance measuring device further includes a shaft member to which the tip member is operably secured to an end of the shaft member. The shaft member is configured and arranged so the user can insert the tip member into an opening, natural or artificial, in the mammalian body (e.g., the vagina) and so the user can localize the tip member proximal to the tissues to be examined and put the electrodes in contact with such tissues by manipulation of the shaft member manually or mechanically. In specific embodiments, the tip member includes a multiplicity of such electrodes that are arranged so portions of each electrode extend a predetermined distance outwardly from a surface of the tip member. In more specific embodiments, the tip member includes three or more electrodes, four or more electrodes, eight or more electrodes, or N×4 electrodes, where N is an integer. In further specific embodiments, the electrodes are arranged so as to form a plurality or more of radially arranged electrodes, so as to form one or more linear electrode arrays each linear array extending widthwise or radial across the tip member surface, or so as to form a non-linear array (e.g., a tetrahedral, rectilinear or circular) of electrodes on the tip surface. In one particular illustrative embodiment, the tip member includes four or more electrodes, more specifically four electrodes that are arranged to form a line of electrodes that are spaced from each other and that extend across a width or radial of the tip member surface. In further embodiments, N linear electrode arrays are arranged and presented on the tip member surface, where N is an integer ≧2. The N linear arrays are arranged so that one array is at an angle with respect to another of the arrays and more specifically so that a midpoint of each linear array is located and arranged so as to be in common (e.g., each linear array forms a radial about a common point of rotation). In a more specific embodiment, the tip member includes two linear arrays that are arranged on the tip member surface so the second array is orthogonal to the first array so as to essentially form a plurality of crossing linear electrodes. In further embodiments, the electrodes of each linear array are arranged electrically so as to form a tetrapolar electrode configuration, such that two of the four electrodes form an electrical circuit when in contact with the tissues so as to allow signals or current from the signal generating/sensing device to flow through the tissue and such that the other of the two electrodes can sense a voltage or other electrical characteristic of the tissue when such signals or current is flowing through the tissue. In yet further more specific embodiments, the predetermined distance for each of the four or more electrodes is controlled such that the electrodes are configured so as to extend from the top surface in a manner that generally mirrors the anatomical structure presented by the opposing cervical tissues. In more particular embodiments, the two electrodes innermost located in the linear array are configured and arranged so that each extend further from the tip surface than either of the two outboard electrodes of the linear array. In more specific embodiments, the pre-determined distance of the inner two electrodes is set such that the force applied on the tissues by the inner two electrodes is not substantially different than the force being applied on the tissues by the outer two electrodes. In another particular illustrative embodiment, the tip member includes four or more electrodes, more specifically four electrodes, that array arranged so the electrodes essentially form a tetrahedral or rectilinear shape across the tip member surface. In further embodiments, the electrodes are arranged so as to form a square and so the electrodes are arranged electrically so as to form a square tetrapolar electrode configuration, such that at any time two of the four electrodes form an electrical circuit when in contact with the tissues so as to allow signals or current from the signal generating/sensing device to flow through the tissue and such that the other of the two electrodes also are electrically coupled to the signal generating/sensing device and so that the other of the two electrodes can sense a voltage or other electrical characteristic of the tissue when such signals or current is flowing through the tissue. In yet another particular illustrative embodiment, the tip member includes three or more electrodes, more specifically three electrodes, that array arranged so the electrodes essentially form a circular electrode array. In more specific embodiments, the circular electrode array includes a centrally located circular electrode and a plurality of annular electrodes, more specifically two annular electrodes that extend about the circumference of the centrally located electrode. In further embodiments, the electrodes of the circular electrode array are arranged electrically so as to form a bipolar electrode configuration, such that two of the three electrodes form an electrical circuit when in contact with the tissues so as to allow signals or current from the signal generating/sensing device to flow through the tissue and such that two of the three electrodes can sense a voltage or other electrical characteristic of the tissue when such signals or current is flowing through the tissue. In more specific embodiments, the first, inner annular electrode disposed between the centrally located circular electrode and the second, outer annular electrode is configured and arranged such that the signals or current generally flow proximal to the surface of the tissues. The centrally located circular electrode also is further configured and arranged such that the signals or current generally flow through tissues in a region that extends substantially beneath the surface of the tissues. Other aspects and embodiments of the invention are discussed below. BRIEF DESCRIPTION OF THE DRAWING For a fuller understanding of the nature and desired objects of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawing figures wherein like reference character denote corresponding parts throughout the several views and wherein: FIG. 1A is a graphical view showing percentage neonatial mortiality as a function of gestational age; FIG. 1B is a graphical view showing the percent incidence of morbidities due to respiratory distress syndrome (RDS) as a function of gestational age; FIG. 2A is a block diagram illustrating a bioimpedance measuring apparatus or device according to the present invention with the cervix; FIG. 2B is a block diagram illustrating an embodiment of the bioimpedance measuring device of FIG. 2A and also illustrating the current path through the apparatus to the cervical tissue; FIG. 3A is a complete schematic view including another embodiment of an illustrative bioimpedance measuring device, a tissue impedance model and a linear tetrapolar measuring probe according to the present invention; FIG. 3B is a schematic view of the signal conversion circuitry of FIG. 3A ; FIG. 3C illustrates the phase measurement process of the signal conversion circuitry of FIG. 3B ; FIG. 4A is an illustrative showing insertion of a measuring probe according to any aspect or embodiment of the present into the vagina; FIG. 4B is an anatomical view illustrating the anatomy of female reproductive organs; FIG. 5 is a graphical view illustrating the variation of collagen in the cervix versus gestation and post gestation; FIG. 6A is a partial cross-sectional side view illustrating a bioimedpance measuring probe according to one aspect of the present invention and configured with one of a plurality of tip embodiments; FIGS. 6B-D are top, side and perspective views respectively of a square tetrapolar probe tip embodiment; FIGS. 7A-C are top, side and perspective views respectively of a linear tetrapolar probe tip embodiment; FIG. 7D is a side view of a linear tetrapolar probe tip according to another embodiment of the present invention. FIG. 7E-F are top views of further illustrative embodiments of a linear tetrapolar probe tip according to the present invention; FIG. 8A is an exploded perspective views of another linear tetrapolar probe tip embodiment illustrating a disposal tip member; FIG. 8B is a perspective view of the bottom of the disposal tip member of FIG. 8A ; FIGS. 9A-C are top, side and perspective views respectively of a bipolar fit probe tip embodiment; FIG. 9D is a schematic side view of the bipolar fit probe tip of FIG. 9B ; FIG. 10 is a schematic view illustrating the electrical coupling between the bipolar fit probe of FIGS. 9A-D with the signal generation and detection mechanism of the present invention; FIG. 11 is a perspective view of another bipolar probe tip according to the present invention; FIG. 12 is an exploded perspective view of a bioimpedance measuring apparatus or device according to another aspect of the present invention; FIG. 13 is a block diagram view illustrating one bioimpedance measuring and analysis system according to the present invention; and FIG. 14 illustrates the Van Der Pauw technique or method. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the various figures of the drawing wherein like reference characters refer to like parts, there is shown in FIG. 2A , a block diagram that illustrates a bioimpedance measuring apparatus 100 according to the present invention that includes a bioimpedance measuring device or bioimpedance measuring probe 120 and a signal generating and sensing device 150 . The signal generating and sensing device 150 includes a signal generator 160 and a sensing device 170 each of which comprises circuitry to carry out the signal generation and sensing functions. The signal generating and sensing device 150 is operably and electrically coupled to the bioimpedance measuring probe 120 and this probe also is electrically coupled to the tissue of the cervix 2 via electrodes 122 ( FIG. 3A ). In this way and as shown more specifically in FIG. 3A , an electrical circuit or pathway is in effect established between the signal generating and sensing device 150 and the cervical tissues when the bioimpedance measuring probe 120 is in electrical contact with the tissues 3 . As is known in the art, when such a pathway is established the signals (i.e., current/voltage) being generated by signal generating and sensing device 150 , more specifically the signal generator 160 thereof, can flow through the cervical tissues 3 . As is shown in FIGS. 2B , 3 A the signal generator 160 can include a function generator 162 , a step down transformer 164 and an external source load 166 . The magnitude and the frequency of the current being outputted is controlled so the outputted current passing through the sample can penetrate the cell membrane and effectively provide a measurement of the resistivity of the cervical tissue and the frequency is controlled so that the current disperses as is passes through the tissue thereby making it possible to measure an impedance (i.e., frequency is such that the current does not pass straight through the tissue without allowing sufficient dispersion of the current). In specific embodiments, the signal generator 160 is configured and arranged so the current passing through the tissue is limited so as not to be more than 0.5 mA, and the voltage being applied to be less than 3V. In further illustrative embodiments, the signal generator 160 is configured and arranged so that a sinusoidal current at 0.1 mA and 50 kHz is generated to pass through the cervical tissue 3 and the voltage being applied to the tissues is about 1.5V. As is more particularly shown in FIG. 3A , the function generator 162 is a circuit formed around a single XR 2206 waveform generator IC. The circuit generates sine, square or triangle waves from 1 Hz to 1 MHz in four switched ranges. There are both high and low level outputs that may be adjusted with the level control. This XR 2206 IC contains an internal square wave oscillator, the frequency of which is controlled by timing capacitors and a potentiometer. The square wave is differentiated to produce a triangular wave, which in turn is shaped to produce a sine wave. Also included are two preset resistors that are provided to adjust the purity of the sine wave. The wave shape switch is a single pole 3 way rotary switch, the wiper arm selects the wave shape and is connected to a potentiometer which controls the amplitude of all waveforms. At the high output, the maximum amplitude is about 3V peak to peak for the square wave and the maximum amplitude for the triangle and sine waves also is around 3V. In a preferred embodiment, the function generator is powered by a 9V DC source. Test have shown that for such a function generator, over the output range the distortion is less than 1%. A 9V battery or DC power source was chosen because it would not be necessary to maintain galvanic separation to ensure the safety of the patient, however it is within the scope of the present invention for the function generator to be powered using any of a number of power sources known to those skilled in that art and also for such power sources to provide appropriate galvanic separation for sources requires such actions. The signal generator 160 include a step down transformer 164 for purposes of further stepping down the voltage being applied to the cervical tissues 3 for purposes of further ensuring safety for the mother and fetus. As more particularly shown in FIG. 3A , in an illustrative exemplary embodiment, the step down transformer is a MET31 (3:1) encapsulated transformer that is operably coupled to the output of the function generator 162 . In more specific embodiments, the MET39 (3:1) encapsulated transformer is such that when the voltage inputted from the function generator 162 is 1.5V, the output voltage, which is the voltage being applied across the cervical tissue 3 is 0.5V. In addition to providing a step down transformer, the signal generator includes an external load source 166 , such as current limiting resistors, so as to thereby control the maximum current that can be generated and passed through the cervical tissues 3 thereby furthering safety of the patient and the medical personnel using the measuring apparatus 100 . As the bioimpedance of the cervix 2 is not expected to exceed hundreds of Ohms, the use of a smaller current is appropriate. In illustrative embodiments the external load source 166 is an external load of about 3.3 kΩ, hence the output of the signal generator 160 consists of an applied voltage of 0.5V, thereby producing a maximum current of 0.14 mA at 50 kHz. As is shown in more detail in FIG. 3A , the output current of the signal generator 160 is passed through the probe 120 , where it penetrates the cervical tissue 3 . The resultant voltage decrease is thus measured with the sensing device 170 . Under certain conditions of frequency, current and voltage, mammalian tissues can exhibit an electrical characteristic such as an impedance or resistance much like any electrical circuit element (e.g., resistor). Thus, the bioimpedance measuring probe 120 also is electrically coupled to the tissues 3 of the cervix 2 so as to be capable of electrically coupling the electrical parameters (e.g., voltage) being sensed to the sensing device 170 of the signal generating and sensing device 170 . The circuitry comprising the sensing device 170 determines or computes the electrical characteristic(s) being exhibited by the tissues based on the sensed information. In more specific embodiments, the sensing device also can provide an output (e.g., a visual display) of the observed or measured electrical characteristic(s). For example, the sensing device 170 can be any of a number of multimeter type of devices known to those skilled in the art that can be used to sense for example the resistance or impedance of ther tissues as well as phase angle. In an illustrative embodiment, the sensing device is an Extech MM560 True-RMS Multimeter, which is a true RMS multimeter, that exhibits good resolution, enabling measurements up to 1 μV, 0.0001 Hz, 0.01 μA and 0.1°. The Extech model also is highly portable (less than 400 g), hence it can be integrated with the signal generating and sensing device 160 . It also is battery powered, so an external source need not be provided to power the device. In addition, the Extech comes equipped with a software package that allows it to interface with a computer to enable easy data storage and analysis. In another illustrative embodiment, and as is shown in FIG. 3A , two of the electrodes 122 the bioimpedance measuring probe 120 measures the resulting voltages in the cervical tissues 3 and the resulting voltage is amplified by a differential amplifier 172 b , which also reduces the noise from the signals source, and the amplified signal is inputted to a signal conversion circuit 174 a . Also, the signal output from the step down transformer 164 is appropriately processed and amplified by a differential amplifier 172 a and inputted to a signal conversion circuit 174 b. With reference also to FIG. 3B , the signal conversion circuits 174 a,b are configured and arranged to convert the sinusoidal voltage signal being inputted into the respective signal conversion circuit to a square wave signal for example by a series of hex inverters. A sinusoidal wave is injected into the cervical tissues 3 because the properties of a square wave has an odd number of harmonics that would complicate the process of signal generation into the tissues 3 . The voltage signals are converted to square wave signals because the zero-crossing points are comparatively much more evident to detect. The two square signals outputted from respective signal conversion circuits 174 a,b are then algebraically processed in an algebraic adder 176 comprised of a series of logic gates that is operably coupled to a Programmable Interrupt Controller (PIC 16F877) microprocessor chip 178 . The PIC 178 measures the phase difference between the two signals. The phase measurement contains several parts. The input Ac current source passes through a reference resistor (wave A; pure resistance) and the actual cervical tissue (wave B: resistance+capacitance→Z=R+jX). The reference resistor value is chosen, for example, to be the average resistance value of non-pregnant women's cervical tissue. Wave B has a negative phase shift due to the capacitive effect of the cervical tissues 3 . Because wave B also has issues with noise, a Schmidt trigger and low pass filter can be added to clean up the signal before phase analysis. Subsequently, logic AND gates are used to algebraically subtract the two waves (waves A,B) and determine the difference between the two square waves (wave C), which provides information about the phase angle Using the sampling rate of the PIC, the timer of the PIC is used to measure and compute the width of wave C, which in turn, is the phase angle. The measured values of the magnitude and phase are displayed, for example on an LCD 190 that is programmed or updated by the PIC chip 178 . Since the refresh rate of the PIC 178 is rapid enough to seem continuous, a two line LCD display continuously shows the impedance measurements as being taken as in real time. In this way, the obstetrician-gynecologist, clinician or diagnostician using a look up chart can compare the measured impedance values to determine how the patient's reading(s) compare in terms of risk of labor induction. Preferably, in further embodiments, the LCD display is further controlled so as to automatically display additional information that relates to the risk of labor induction; in other words provide an indication that the reading is out of norm or providing an out of normal message instead of displaying the measured values. The use of the bioimpedance measuring apparatus 100 can be best understood from the following discussion with reference to FIGS. 4 A,B. Reference also should be made FIGS. 2-3 for further details of the bioimpedance measuring apparatus 100 not otherwise shown in FIG. 4A . Prior to use, the bioimpedance measuring probe 120 is disconnected from the signal generating and sensing device 150 and the measuring probe is sterilized using any of a number of techniques known to those skilled in the art and compatible with the construction of the measuring probe. In an illustrative embodiment, the probe is sterilized in a standard autoclaving unit, according to the established protocols and methods for such use. To minimize the potential for damage, the autoclave's flash or quicker sterilization protocol may be used as opposed to the full cycle mode. As hereinafter provided, the materials comprising the measuring probe preferably are selected so as to be compatible with typical autoclave temperatures (e.g. 160° F.). After sterilization, the measuring probe is allowed to cool before it is re-coupled with the signal generating and sensing device 160 . Another method of sterilization is to soak the probe in ethylene glycol solution after each use. In alternative embodiments, the measuring probe 120 is sterilized and provided by the manufacturer in the sterilized condition in a kit or package. In such, a case, the sterilized measuring probe 120 would be removed from the protective packaging and coupled to the signal generating and sensing device 160 . The clinician/diagnostician/medical personnel (i.e., user) turns the signal generating and sensing device 150 on so as to be capable of outputting the desired current and voltage from the probe electrodes 122 to the tissues as well as being capable of sensing the desired electrical parameters (e.g., voltage) of the tissues and determining and outputting the desired parameter(s). The clinician/diagnostician then inserts the measuring probe 120 into an opening provided in the mammalian body, which in the illustrated embodiment is a natural bodily opening (i.e., the vagina). The measuring probe is inserted so that the tip member 124 of the probe is within the bodily opening and so a portion of the shaft member 126 remains outside so as to be handled or manipulated by the user. While the use of natural body opening is contemplated, it also is contemplated that the measuring probe could be inserted into an opening formed for example by surgical intervention. The clinician/diagnostician or medical personnel further manipulates the measuring probe 120 such that the electrodes 122 are positioned proximal the tissues to be examined/evaluated and further manipulated such that all the electrodes contact these tissues. In more specific embodiments, the measuring probe 120 is manipulated so that the electrodes 122 are proximal to and in contact with tissues of the cervix. After inserting the measuring probe 120 and putting the probe electrodes 122 into contact with the cervical tissues 3 , the measuring process begins and measured parameters would be displayed to the user. As described herein, in further embodiments the bioimpedance measuring probe 120 is further configured and arranged so as to include a mechanism for manually controlling the application of the voltage and current to the probe electrodes 122 . In this way, the probe electrodes 122 that would supply the current to the tissues are not energized as the device is being manipulated. This provides a further measure of safety to the patient, fetus and user. Thus, after inserting the probe and putting the probe electrodes 122 into contact with the cervical tissues 3 , the clinician/diagnostician would actuate the control mechanism (e.g., switch) so the measuring process begins as described above. After acquiring or measuring the bioimpedance parameter(s) and/or other related diagnostic information, the user can reposition the probe electrodes so they are oriented differently with respect to the cervical tissues. This would be accomplished by the user disengaging the probe electrodes 122 from the cervical tissue and manipulating the measuring probe 120 so that the electrodes are in a different orientation (e.g., rotate the measuring probe). After completing the measuring process, the user would withdraw the measuring probe from the opening in the body. From the bioimpedance information obtained, the clinician/diagnostician can draw an inference about cervical tissue consistency, tensile strength and possible infiltration with neoplasm. Such information would assist and enhance important clinical management decision-making in a novel way, as “tissue-level” analysis will be made available in a non-invasive manner, as well as at an earlier time than when this information would otherwise have become evident or detectable clinically using conventional techniques. As indicated herein, there are many conditions that may result in pre-term delivery and that regardless of cause, the softening, dilation, and effacement of the cervix during pregnancy and labor do not occur as a result of uterine contractions alone, but are also a result of an active remodeling of the structure of the cervix. In the transition to labor, the tissue of the human pregnant cervix undergoes significant remodeling, such that its predominantly collagen matrix is replaced by glycosaminoglycans. This collagen matrix reduction can be seen from the graphical illustration provided in FIG. 5 . As a result of this “ripening,” the cervix softens, thereby preparing for the thinning and dilation that will ultimately be required to allow the fetus to exit the womb. As the ratio of collagen to glycosaminoglycan decreases, the substance of the cervix becomes more hydrophilic. This is a feature or characteristic that should be measurable as changes in electrical conductivity of the tissue. Such changes in bioimpedance should be detectable at a tissue level well before it would be detectable clinically by digital palpation. Since the methods of the present invention can provide earlier detection of the onset of labor as compared to conventional techniques, several treatments can be considered and implemented that can be very effective in delaying labor until an acceptable gestational age and level of fetal development occurs. As such, these treatments are expected to be more effective and safer to the pregnant women as detection is achieved or caught early in the gestation period. Also, because detection is likely to occur prior to rupture of the amniotic membrane, drugs that are otherwise not safe to use once the amniotic membrane has ruptured due to the increased medical risk of uterine and fetal infection, can be used for treatment. Thus, in further embodiments, the clinician/diagnostician based on the results of the bioimpedance measurements can determine an appropriate treatment that can vary from something as simple as bed rest to drugs that can be administered in an effort to postpone labor or arrest its progression. Such drugs include, but are not limited to beta-adrenergic receptor agonists, magnesium sulfate, calcium channel blockers, cyclooxygenase inhibitors, salbumatol, lidocaine and nitric oxide/nitric oxide donors. Corticosteriods also are frequently employed as a specific treatment to the premature fetus to enhance organ maturation as well as improving fetal lung function by speeding development of the lungs and respiratory enzymes necessary for oxygen transfer. These also may decrease the risk of intraventricualar hemorrhage and injury to the gastrointestinal tract. Referring now to FIGS. 6A-D , there is shown an embodiment of a bioimpedance-measuring probe 220 according to the present invention. The measuring probe 220 includes a top member 224 , a shaft member 226 , a plurality or more, more particularly four or more, more specifically four, electrodes 222 and interconnecting wires 228 . The shaft member 226 includes an axially extending lumen or through aperture 225 in which pass the interconnecting wires 228 . The shaft member 226 also is arranged so an end 227 thereof receives a portion of the top member 224 in the through aperture. In this way, the top member 224 is in mechanically engagement with the shaft member 226 so as the top member and shaft member form a unitary structure. In further embodiments, the top member 224 is in removable engagement with the shaft member 226 such that by application of a force, the top member can be removed from the shaft member for replacement or for other action. The top member 224 is configured and arranged so that the electrodes are disposed in and extend from a top surface 223 of the top member and extend axially. Each electrode also is configured and arranged so as to have a length sufficient so one end of each electrode is located a predetermined distance from the top member top surface 223 . Each of the electrodes 222 also are arranged so as to form or define a non-linear electrode array including a tetrahedral, rectilinear or circular array of electrodes. In a more specific and illustrative embodiment, the electrodes 222 are arranged in the top member 224 so as to form a square array that forms a square tetrapolar electrode array. The interconnecting wires 228 interconnect each of the electrodes to a signal generating and sensing device 150 that is particularly configured and arranged for use with a square tetrapolar electrode array. A tetrapolar electrode array when used with the Van der Pauw technique of resistance measurement that allows one to obtain an averaged reading of the bioimpedance measurements. According to this technique, and with reference also to FIG. 14 , the resistance reading is taken across 4 points on the sample area and the resistivity of the entire tissue is then computed by taking a geometrically corrected average of these readings. This technique is used in the present invention because the area of the tissue being samples is very small (˜2 mm 2 ). Moreover, because the bioimpedance values within the cervical tissue may fluctuate, an averaged value affords greater consistency. The Van der Pauw technique entails making a series of potential difference readings across four sample points defined on an arbitrary square sample or circular area. According to this technique a set of the probe electrodes 222 (i.e., any two of the four electrodes) are interconnected to the signal generator 160 and are supplied the current that is to flow through the cervical tissues. The other set of probe electrodes (i.e., the other two of the four electrodes) are coupled to the sensing device 167 so as to measure the potential difference. This setup is then rotated through all the possible probe electrode 222 combinations. Hence, two of the probe electrodes 222 are connected to the sensing device 170 tips for the potential difference measurement and two of the probe electrodes 222 are connected to the output from the signal generator 160 (after voltage and current have been stepped down by the transformer and external load respectively). Using the appropriate formulas for this technique, an averaged reading can be obtained. In an exemplary illustrative embodiment, the electrodes 222 are secured in the top member 224 . In an alternative embodiment, the electrodes 22 and top member 224 are configured and arranged using any of a number of techniques known to those in the art (e.g., spring loaded electrodes, sliding electrodes so that the electrodes are maintained in an essentially fixed relation laterally with respect to the top member top surface 223 and so that the electrodes can move axially or lengthwise so as to move inwardly or outwardly with respect to the top member top surface. The top member 224 and shaft member 226 preferably have a cross-sectional shape and size that is appropriate for the intended use. In illustrative embodiments, when the top and shaft members 224 , 226 are secured to each other they generally form a cylindrical member sized so as to be capable of being inserted into the vagina during routine obstetrical or gynecological examinations as well as presenting a device that can be manipulated by the user. The length of the shaft member 226 is set so that the user can manipulate the bioimpedance measuring probe 220 outside of the body opening (e.g., vagina) as is illustrated in FIG. 3A . Each of the top and shaft members 224 , 226 are constructed of materials that are appropriate for the intended use and are biocompatible. The materials also are preferably suitable for the sterilization protocols (e.g., heating) that are used for sterilize the bioimpedance measuring probe 220 prior to its use in a medical procedure/insertion into a bodily opening. The materials for the shaft member 226 also are appropriate for the expected loads and forces that are imposed thereon while the shaft member is being manipulated and while the electrodes 222 are being maintained in engagement with the cervical tissues The electrodes are appropriately dimensioned for the intended us and are constructed from materials that are biocompatible and appropriate for the intended use. Such materials include gold, silver and copper and alloys thereof and in a specific embodiment the electrodes are made from a silver-copper alloy. It should be recognized that the foregoing is illustrative and that other materials, such as stainless steel, can be used if the electrical and material characteristics for such other materials are otherwise satisfactory for the intended use. Referring now to FIGS. 7A-F there is shown various views of embodiments of a top member 324 that is configured and arranged so the electrodes 322 are arranged so as to form a one or more linear electrode arrays that extend widthwise or radially across the top surface 323 of the respective top member. Each of the one or more linear electrode arrays is comprised of a plurality or more of electrodes 322 , more particularly four or more electrodes and in an exemplary illustrative embodiment, comprised of four electrodes. The electrodes 322 also are arranged so as to be spaced from each other so as to minimize field distribution problems and electrode irregularities. Such a linear electrode also yields a design having negligible electrode polarization. It is contemplated that the top members illustrated in FIGS. 7A-F would be used in combination with a shaft member such as the shaft member 226 shown in FIG. 6 . As such, reference shall be made to the foregoing discussion for FIG. 6 for details of the shaft member. Each of the linear electrode arrays comprises a linear tetrapolar probe electrode array in which two of the electrodes are electrically coupled to the signal generator 160 and the other two electrodes are electrically coupled to the sensing device 170 . In an exemplary illustrative embodiment, the outer two electrodes of each linear array are electrically coupled to the signal generator 160 and the inner two electrodes of the array are electrically coupled to the sensing device 170 according to another embodiment of the present invention. In the embodiment shown in FIGS. 7A-C , the electrodes 322 are spaced from the top member top surface 323 so that the exposed electrode end, the end that would contact the cervical tissues, is spaced the same from the top surface for all electrodes (i.e., the electrode ends for all electrodes lie in the same plane). Referring now to FIG. 7D , there is shown a top member 324 a according ton another embodiment of the present invention. In this embodiment the lengths of the exposed portions of the electrodes are controlled so that the exposed electrode ends essentially mirror the opposing anatomical surface that they are to contact. In an illustrative embodiment, the lengths of exposed portions of the two inner electrodes extend further from the top surface 323 the exposed portions of the two outer electrodes. Referring now to FIGS. 7E-F there are shown are top views of further illustrative embodiments of top members 324 b,c that are configured with a plurality or more of linear electrode arrays. The top member 324 b embodiment that is shown in FIG. 7E , is configured with two linear arrays that are arranged so that each are at an angle with respect to each other. In more particularly embodiments, the arrays are arranged such that a midpoint for each array is in common. In a more specific embodiment, the two linear electrode arrays are arranged so as to be orthogonal to each other. The top member 324 c embodiment that is shown in FIG. 7F is configured so as to include a multiplicity or more of linear electrode arrays, more specifically eight linear electrode arrays, where the arrays are arranged so that each are at an angle with respect to adjacent linear array. It is within the scope of the present invention for the angle between adjacent arrays to be the same or different. As indicated above, for the top member embodiments, shown in FIGS. 7A-D , two of the electrodes are coupled to the signal generating device 160 and the other two electrodes are coupled to the sensing device 170 . In the embodiments shown in FIGS. 7E-F , it is within the scope of the present invention for the electrodes of each linear array to be selectively coupled to the signal generating device 160 and the sensing device so that the each linear array sequentially measures the bioimedance of the cervical tissues in the region bounded the linear array. In this way, the user can obtain a plurality or more of bioimedance measurements where the electrodes are in effect positioned at a different location from a prior arrangement and so the multiply acquired bioimedance values can be averaged so as to yield an average value. Such an arrangement also avoids the need for the user to manipulate the shaft member 226 ( FIG. 6A ) so as to reposition the electrodes for each data acquisition. This thereby would speed up data acquisition as well as reducing stress and discomfort that could arise when a measuring probe was being manipulated so as to reposition the electrodes for another data acquisition. Referring now to FIGS. 8 A,B there is shown a top member 424 according to another aspect of the present invention that is configured and arranged so as to include a base portion 430 and a removable cover portion 432 . It is contemplated that the top member illustrated in FIGS. 8A-B would be used in combination with a shaft member such as the shaft member 226 shown in FIG. 6 . As such, reference shall be made to the foregoing discussion for FIG. 6 for details of the shaft member. Also while the embodiment illustrated in FIGS. 8 A,B is that on a linear electrode array or a linear tetrapolar array, it is contemplated that any of the top member embodiments illustrated in any of FIGS. 6-7 can be configured so as to comprise a base portion and a removable cover portion. The base portion 430 is secured to the shaft member 226 in the same manner as for any of the top members 224 , 324 described in FIGS. 6-7 as such reference shall be made to the foregoing discussion. The base portion 430 also is configured and arranged so as to include a plurality of electrodes 434 extending outwardly from a top surface of the base portion. The base portion electrodes 434 also are arranged so as to mirror the arrangement for the electrodes 422 provided in the cover portion. In the illustrated embodiment, the base portion electrodes 434 are arranged to form a linear electrode array that mirrors the spacing and arrangement of the electrodes in the linear array formed in the cover portion 432 . In use, the cover portion is configured an arranged so as to include an open region 433 extending downwardly towards a bottom of the cover portion. The open region 433 and a mating surface of the base portion are preferably sized and configured so that cover portion removably, mechanically engage each other so the cover portion is retained on the base portion. In addition, the cover portion electrodes 422 are configured and arranged so as to form a pocket or axially extending aperture at a bottom edge thereof in which is received a corresponding portion one of the bottom portion electrodes 434 thereby forming a male-female type of electrical connection between these electrodes 422 , 434 . It is contemplated that the cover portion electrodes 422 and the base portion electrodes 4334 may be adapted using any other connecting techniques known to those skilled in the art so as to form an electrical connection between corresponding electrodes when the cover portion 432 is removable secured to the base portion 430 . Referring now to FIGS. 9-10 there is shown a top member 524 for a bipolar bioimpedance probe. It is contemplated that the top member illustrated in FIGS. 9A-D would be used in combination with a shaft member such as the shaft member 226 shown in FIG. 6 . As such, reference shall be made to the foregoing discussion for FIG. 6 for details of the shaft member. Such a top member includes a central electrode 522 a , an inner annular electrode 522 b that is arranged so as to extend about the circumference of the central electrode and an outer annular electrode 522 c that is arranged so as extend about the circumference of the inner annular electrode. As is more clearly appears in FIGS. 9B-D , the ends of each of the central and annular electrodes 522 a - c are each configured and arranged to mirror the contacting surfaces of the opposing cervical tissues. In addition, the central electrode 522 a is configured and arranged so as the current being injected into the cervical tissues by the central electrode will reach a desired depth within the cervical tissues. Also, the inner annular electrode 522 b is configured and arranged so as the current being injected into the cervical tissues by the central electrode will generally remain at the surface of the tissue. This further biases the current being injected from the central electrode 522 a so it reaches deeper within the cervical tissues. In use, and as illustrated in FIG. 10 , the central electrode and the inner annular electrode are coupled to the signal generating device 160 so that the same voltage is being applied to the cervical tissues by these two electrodes and the outer annular electrode 522 c forms or completes the electrical circuit. As also shown in FIG. 10 , the sensing device is arranged so as to extend between two of the electrodes so as to measure the voltage in the tissue. Reference shall be made to the foregoing discussion regarding FIGS. 6-7 as to the materials for the top member 524 and the electrodes, although it is contemplated that the electrodes can be made from other electrically conductive materials. Referring now to FIG. 11 , there is shown an exploded view of a bioimpedance measuring apparatus 600 according to another aspect of the present invention. Such an apparatus includes a bioimpedance measuring probe 610 , a spring 620 and a handle member 650 . The bioimpedance measuring probe 610 comprises any of the measuring probes described herein but wherein the shaft member 612 would be configured so as to further include a stop 614 upon which one end of the spring 620 would rest. The handle member 650 is configured an arranged so as to house the signal generating and sensing device 150 including the signal generator 160 and the sensing device 170 and an LCD display 190 . The handle member 650 also is configured with an axially extending aperture having a base or end, and in which aperture is received the spring 620 and a portion of the shaft member 612 . The other end of the spring 620 would rest upon the base or end of the handle aperture 652 when the measuring apparatus 600 is assembled. In use, the user would manipulate the handle member 650 to insert the top member 616 into the bodily opening and thereafter manipulate the handle so as to cause the electrodes 618 to be positioned proximal to and in contact with the cervical tissues 3 ( FIG. 4A ). The spring 620 is preferably configured and arranged such that the electrodes are generally maintained in continuous contact with the cervical tissues and without a an appreciable variance in the force being applied to the tissues by the electrodes regardless of any force variations that may be introduced by a movement of the handle. In this way, because the force being exerted by the electrodes on the tissues should not significantly vary, the bioimpedance being measured should not appreciably fluctuate even when the force being applied to the handle varies. Also, it is preferable that the spring is configured so as to limit the maximum force that can be applied by the axial movement of the handle so as to be less than a desired value. As also shown in FIG. 12 , and as described herein, the handle member 650 is arranged so as to include a mechanism, switch or button 660 that is used to control the activation of the signal generator 160 and/or the electrical interconnection of the signal generator to the one or more electrodes that inject the current into the cervical tissues. In such an embodiment, the circuitry and button 660 would be arranged such that current does not flow, nor is a voltage applied across the electrodes except and when the button 660 is actuated. Referring now to FIG. 13 , there is shown a bioimpedance measuring system 800 according to the present invention for use in combination with any of the bioimpedance measuring apparatuses 100 , 600 disclosed and taught herein as well as any of the bioimpedance measuring devices also disclosed and taught herein. For illustration purpose, the following discussion refers to the bioimpedance measuring apparatus 100 of FIG. 2A and a the bioimpedance measuring device 120 of FIG. 2A , 3 A. As such reference shall be made to the discussion for these figures as to further details of the features and elements of these apparatus and device not otherwise described below. The bioimpedance measuring system 800 also includes a communication interface 810 and a computer processing system 820 . The computer processing system 810 is any of a number of systems known to those skilled in the art and generally includes a microprocessor and random access memory in which are executed applications programs and operating systems that are for processing data, performance of calculations and controlling of I/O operations for example as well as permanent storage devices or memory systems (i.e., systems that retain information after power to computer systems is turned off) such as those embodying magnetic hard disks and/or optical disks, which storage systems also can comprise an external array of such magnetic hard disks and optical disks (e.g., RAID configuration). The communications interface 810 is any of a number of communications systems, devices or apparatuses known to those skilled in the art by which information can be selectively communicated from an external input device, such as a signal generating and sensing device 150 of the present invention to the computer processing system 820 . Such communication interfaces 810 can embody any of a number of communications techniques known to those skilled in the art, including wireless communication techniques (e.g., RF and IR), wired communication techniques (e.g., electrical signals and optical signals), and an interface device (e.g., docking station) as well as systems that embody a combination of such communication techniques. In addition, it shall be understood that a communication interface 810 according to the present invention also shall include wide array and local area networks as well as embodying communication systems where communication is effected via the Internet. It also shall be understood that the while communication with a single computer processing system 820 is shown, this shall not be construed as a limitation on the present invention as it is contemplated that such communications can be made with between the bioimpedance measuring apparatus and more that one computer system. For example, acquired bioimepdance measurement data could be transferred to a computer system that is for the specific user and to another computer systems that is tasked to acquire data for histological analysis purposes. Alternatively, the computer processing system 820 is connected via the communications interface 810 or via another communications system to the another computer system for transmission of the historical data to the another computer system. The signal generating and sensing device 150 a of the present invention further includes a communication interface device 155 that is configured and arranged so as to provide a mechanism for transferring the data acquired by the sensing device 170 to the communication system(s)s embodied in the communication interface 810 and to the computer processing system 820 . In further embodiments, the communication interface device 155 also is configured and arranged so as to receive an output from the computer processing system 820 and to input this to the display so that this information contained in the processing system output can be displayed on the display 190 . In this way, diagnostic and clinical information that is based on the measured information can be provided to the clinician or diagnostician without requiring them to specifically access the computer processing system for such information. In one exemplary embodiment, the communication interface device 155 is any of a number of wireless communication devices or a device for use with any of a number or wired communication techniques (e.g., Ethernet). It is contemplated that such the signal generating an sensing device 150 a and the communication interface device 155 also are configured and arranged so that such data communication of the measured bioimpedance data is processed and outputted to the computer processing system 820 essentially in real time. In other words, the data is processed and sent to the computer processing system 820 n as it is being acquired. In another embodiment, the bioimpedance measurement data is acquired and stored in the signal generating and sensing device 150 a as it is being acquired. Following acquisition of all of the data, the user would operably couple the communication interface device 155 to the communication interface 810 (e.g., connect a network cable or USB cable to the communication interface device 155 and to the network communication system/computer processing system) so that the acquired data is sent to the computer processing system for processing (e.g. batch mode processing). The communication interface device 155 also can comprise a device including the appropriate electrical connections for docking with a docking station when the communication interface 810 includes or comprises a docking station. Typically, a communications link would have already been established between the docking station and the computer processing system 820 . Thus, following acquisition of all data, the user would operably couple the communication interface device 155 to the docking station so that the acquired data is sent to the computer processing system for processing (e.g., batch mode processing) via the docking station. In particular embodiments, the computer processing system 810 further includes an applications program(s) 822 and a database 824 that is stored in the permanent storage system that are for use in combination with a bioimpedance measuring apparatus according to the present invention. In one exemplary embodiment, the applications program would include instructions and criteria for acquiring the data and storing it in a predetermined fashion in the database so it can be later retrieved by the clinician/diagnostician for analysis and evaluation. For example, the diagnostician/clinician can access all of the measurement data acquired over a period of time for a given patient (e.g., different visits by the patient) to determine if the measurement data is indicating that any trends or changes are occurring so that the clinician can determine if further action should be taken. In an obstetrical setting, this could be a determination that there is an indication of the onset of pre-term labor thereby allowing the obstetrician or gynecologist to determine if action should be taken to delay such delivery (e.g., diagnosis bed rest). In a non-obstetrical setting the clinician/diagnostician could use the information to determine if further tests should be undertaken to determine the cause for such changes. The information also could be used as further confirmation of the results of another type of test (e.g., pap smear) before proceeding with more invasive examination or diagnostic techniques (e.g., biopsy). In yet further embodiments, it is contemplated that the database also include histological information that relates bioimpedance measurements to more specific clinical or diagnostic information as simple as for example that a given bioimpedance measurement is out of normal for the patient in question (e.g., age, pregnant or not pregnant, gestation time, etc). As such, the applications program would further include information and criteria to compare the histological data or information with the acquired measurement data and other pertinent input data and determine the histological clinical/diagnostic information that relates to the measurement data. The applications program also further include instructions and criteria for outputting such clinical/diagnostic information to the user for example displaying the information on the display 190 . Although a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. INCORPORATION BY REFERENCE All patents, published patent applications and other references disclosed herein are hereby expressly incorporated by reference in their entireties by reference. EQUIVALENTS Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents of the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

Featured are apparatuses for measuring bioimpendence of tissues of the cervix, more specifically the mammalian cervix. Also featured are methods for examining the tissues of the cervix for clinical or diagnostic purposes such as during routine gynecological examinations to determine early onset of labor in pregnant patients or to assess such tissues for the presence of abnormalities such as cancerous lesions in both pregnant and non-pregnant women. Also featured are methods for treating onset of early or pre-term labor that embody such devices, apparatuses and methods of the present invention. Also featured are systems embodying such devices, apparatuses and/or methods, where such systems preferably are configured to provide diagnostic and/or clinical information to further assist the diagnostician or clinician in diagnosing and/or examining pregnant or non-pregnant patients.

This application is a divisional of U.S. application Ser. No. 08/878,006, filed Jun. 18, 1997 now U.S. Pat. No. 6,178,448. FIELD OF THE INVENTION The present invention relates to communications networks and more particularly to communications networks having multiple physical links, paths, connections or virtual circuits between two nodes. BACKGROUND OF THE INVENTION In recent years there has been a proliferation in the networking of computer systems. The recent expansion of the Internet is just one example of the trend toward distributed computing and information sharing. In most forms of computer or communication networking there are communication paths between the computers in the networks. These paths may include multiple links or hops between intermediate equipment in a path. Thus, a communication may be originated by a first computer and pass through several links before reaching the destination computer. The control over these communications is typically carried out under a networking architecture. Many networking architectures exist for defining communications between computers in a network. For example, System Network Architecture (SNA) and Transfer Control Protocol/Internet Protocol (TCP/IP) are two examples of existing network architectures. One existing network architecture for controlling communications between computers is known as Advanced Peer to Peer Networking (APPN). APPN, like many networking architectures, is based upon the transmission of data packets where a communication is broken into one or more “packets” of data which are then transmitted from the source to the destination over the communication path. Packet based communications allows for error recovery of less than an entire communication which improves communication reliability and allows for packets to take multiple paths to an end destination thus improving communicaton availability. One error condition which many networks attempt to correct for is packet loss. Packet loss in a network may be broadly characterized as resulting from congestion on the path from the source to the destination or from loss of data (bit error) by links in the path. Congestion may result from too high a data packet rate for a path. Bit error may, however, result from any number of failures in a communication link. For example, sun spots may adversely impact microwave transmissions and cause loss of data. However, bit error occurrences are generally highly correlated. As a result, a time averaged bit error rate (BER) alone may not accurately describe line quality. Line quality is, therefore, usually described using a combination of an average BER over some time period along with the number of seconds in the time period in which one or more bit errors occur. While APPN has proven to be a reliable networking architecture, as computer networking demands have increased these demands have created a demand for network architectures which utilize the higher performance communication systems and computer systems currently available. In part because of these demands, High Performance Routing, which is an enhancement to APPN, was developed. Processing capability has increased and become less expensive. This has driven the need for larger peer-to-peer networks. Link technology has advanced by several orders of magnitude over the past decade. Advances in wide area links have dramatically increased transmission rates and decreased error rates. Thus, to take advantage of these advances HPR provides high speed data routing which includes end-to-end recovery (i.e. error recovery is performed by the sending and receiving systems) and end-to-end flow and congestion control where the flow of data is controlled by the sending and receiving systems. HPR consists of two main components: the Rapid Transport Protocol (RTP) and automatic network routing (ANR). RTP is a connection-oriented, full-duplex transport protocol designed to support high speed networks. One feature of RTP is to provide end-to-end error recovery, with optional link level recovery. RTP also provides end-to-end flow/congestion control. Unlike TCP's reactive congestion control, RTP provides an adaptive rate based mechanism (ARB). ARB provides end-to-end flow control to prevent buffer overrun at the RTP endpoints, a rate based transmission mechanism that smooths input traffic and a preventive congestion control mechanism that detects the onset of congestion and reduces the RTP send rate until the congestion has cleared. The ARB preventive congestion control mechanism attempts to operate the network at a point below the “cliff” (shown in FIG. 1 ) and to prevent congestion. A reactive mechanism, on the other hand, detects when the network has entered the region of congestion and reacts by reducing the offered load. In RTP, the ARB mechanism is implemented at the endpoints of an RTP connection. Each endpoint has an ARB sender and an ARB receiver. The ARB sender periodically queries the receiver by sending a rate request to the ARB receiver who responds with a rate reply message. The sender adjusts its send rate based on information received in the rate reply message. The mechanism used to control the send_rate is as follows. A burst_size parameter sets the maximum number of bytes a sender can send in a given burst at a given send_rate. During each burst_time, defined by burst_size/send_rate, a sender is allowed to send a maximum of burst_size bytes. The receiver continuously monitors network queuing delay looking for the initial stages of congestion. Based on this assessment and also based on the current state of the receiver's buffers, the receiver sends a message to the sender instructing it to either increment the send_rate by a rate increment, keep the send_rate the same, decrement the send_rate by 12.5%, decrement the send_rate by 25%, or decrement the send_rate by 50%. The receiver initiates error recovery as soon as it detects an out of sequence packet by sending a gap detect message that identifies the packets that need to be resent. When the sender receives a gap detect message, it drops its send_rate by 50% and resends the packets at the next send opportunity. If the sender does not get a response to a rate request within a time-out period, the sender assumes the packet is lost and cuts the send_rate by half, increases the rate request time-out exponentially (exponential back off), and transmits a rate request at the next send opportunity. Thus, like many forms of networking, in RTP packet losses are assumed to result from congestion rather than bit errors. Such an assumption may often be valid for modern digital wide area links which exhibit low loss rates. However, these loss rates may not apply to all communication links around the world or even to high quality links all the time. Furthermore, as RTP provides end-to-end flow control, the send rate of packets on a path may be limited by the slowest link in the path (i.e., the bottle-neck link). Thus, despite a path having high-speed links in the path if a single low-speed link is present, the sender and receiver will pace the transmission of packets to accommodate the low speed link. Thus, a congestion problem or the presence of one low speed link in a path may degrade the throughput for the entire path. One way to improve congestion problems or to compensate for differing transmission rates on a communications path is to provide for multiple links between connection points that may be the bottle-neck in the path. HPR provides for such concurrent links through a Multilink Transmission Group (MLTG). Similarly, TCP/IP provides ofr multiple links with multi-link Point to Point Protocol (PPP). A transmission group is a logical group of one or more links between adjacent nodes that appears as a single path to the routing layer. A MLTG is a transmission group that includes more than one link. Links in a MLTG are referred to herein as sublinks. An MLTG can include any combination of link types (e.g., token-ring, SDLC, frame relay). MLTGs provide increased bandwidth which may be added or deleted incrementally on demand. Furthermore, the combined full bandwidth is available to a session since session traffic can flow over all sublinks in the group. MLTGs also provide increased availability. An individual sublink failure is transparent to sessions using the MLTG. One drawback of an MLTG is that packets flowing over an MLTG can arrive at the RTP endpoint out of sequence. Thus, RTP must know if an MLTG is in a path. At connection establishment, RTP learns if there is an MLTG in the path. If an MLTG is not in the path, any data received that is out of sequence causes error recovery (i.e., the receiver sends a gap detect message to the sender). If an MLTG is in the path, error recovery is delayed. When the receiver detects out of sequence packets, it initiates a time-out procedure before sending the gap detect message. The time-out procedure allows enough time for all packets to arrive before initiating recovery. The addition of an MLTG to a path also requires the endpoints of the MLTG to schedule packets to the sublinks of the MLTG. This distribution of packets among the concurrent links is presently accomplished in a number of ways, including round-robin, weighted round-robin and link metered pacing approaches. In a round-robin approach packets are distributed to sublinks in the MLTG by a simple sequential distribution to the links. This approach, however, does not take into account the possibility of differing link rates as well as possible congestion on a link or bit errors on a link in the MLTG. In the weighted round-robin scheme, the scheduler maintains a count field for each sublink. Going in a fixed (round robin) order, the scheduler assigns a first group of packets to a first sublink, then assigns a second group of packets to a second sublink and so on through all of the links. The count field for a sublink is incremented each time a packet has been assigned to it. Once the count field equals the weight of the sublink, the scheduler moves on to the next sublink in the list. The weight values determine the relative frequency of use of each sublink by the MLTG scheduler. For example, if an MLTG consists of 2 sublinks with weights of 1 and 2 respectively, then the sublink with weight 2 will be allocated twice as much data as the other sublink. However, if the right mixture of dynamics does not exist, it is possible that the flow distribution over the sublinks will deviate from the optimal flow specified by the weights. For example, if small packets flow over one link while large packets flow over another link, the result will be sub optimal RTP throughput (a similar effect occurs if the sublink weight values are incorrect). Furthermore, if loss occurs on one of the sublinks, there is no mechanism to account for the change in throughput of the sublink. For example, as seen in FIG. 2 , at a sustained BER of 10 −6 , an RTP connection over a single 1500000 BPS link would have an effective throughput of 100000 BPS. With a 2 link MLTG, if one 750,000 BPS link experienced a sustained BER of 10 −6 , the RTP throughput would be roughly 250000 BPS. The error free link would be significantly underutilized (less than 25%). The solid “O” curve in FIG. 2 illustrates the results of a simulation of RTP performance over an MLTG with two sublinks. The curve illustrates one of several problems associated with running RTP over MLTG. At some point, in this case at a BER of about 3*10 −7 , RTP performs worse than if there was just a single (well behaved) link. This inefficiency follows from each packet loss resulting in a send_rate reduction of 50% to both links in the MLTG. Furthermore, with any weight based MLTG scheduling system the algorithm is dependent on accurate weight values. A weighted round-robin algorithm requires static weights that must be as close to optimal as possible. The weight values typically are based on link speeds and provide a simple way to load balance the flow over the sublinks. Inaccuracy in weighting may be a significant problem given the number of multiprotocol link and subnet technologies (e.g., PPP, X.25, multiprotocol encapsulation over frame relay, multiprotocol encapsulation over ATM AAL5), it may be impossible to know the exact throughput available to a particular protocol over a multiprotocol link layer. Consequently, it may be impossible to know the correct weight values that should be assigned to each sublink. An incremental extension to weighted round-robin MLTG scheduling adds a simple check before the scheduler assigns a packet to a sublink. If the sublink is in error recovery, it will not be used until the link has recovered. To implement this, the MLTG scheduler must monitor when a sublink goes in and out of error recovery state. If the sublink is in error recovery, the packet is submitted to another available sublink. If all links are in recovery, the packet is queued in an MLTG queue until a sublink is available. However, such error recovery may provide minimal improvement over the simple weighted round-robin method. By the time it is learned that a sublink is in recovery, it is too late. The scheduler might have scheduled many packets to the sublink. Also, when operating over a lossy sublink, the link may toggle in and out of error recovery frequently. The next MLTG scheduling method, which is referred to as link metered pacing, is based on the SEND_MU signal defined by SNA architecture. The Data Link Control layer (DLC) issues a SEND_MU signal to Path Control when it is ready to accept additional frames for transmission. The mechanism allows component level pacing between the DLC and Path Control layers. An Error Recovery Protocol (ERP) DLC typically issues a SEND_MU after one or more frames have been successfully acknowledged. The SEND_MU signal provides the mechanism by which the MLTG scheduler sends a controlled amount of data to a sublink (call this amount the MAX_TOKENS) and then waits for a request for more data. The idea is to keep enough data queued in the DLC to keep the transmitter busy, but to have an upper bound so that the DLC queue level is controlled. If a link goes into error recovery (ER), the queue buildup occurs in the MLTG queue allowing RTP to quickly detect and react to the congestion. Therefore, link metered pacing avoids the queue explosion that can occur with the round-robin methods. In one manner of implementing link metered pacing, MLTG maintains a MAX_TOKENS variable for each sublink in the transmission group that represents the maximum number of packets that can be sent to a sublink DLC at any time. A PACING_TOKEN_COUNT variable tracks the number of available tokens at any time. The count is initially set to the MAX_TOKENS value. The MLTG scheduler decrements the count as it assigns packets to a sublink. To ensure even flow over all sublinks, the scheduler implements a simple round robin scheduling policy for sublinks that have not run out of tokens. Once a sublink's PACING_TOKEN_COUNT reaches 0, MLTG stops using the sublink. Once a sublink is out of tokens, any other sublink with tokens is used, even if this means violating the round robin sequence. The sublink DLC has a DLC_SEND_COUNT variable. Each time a frame is acknowledged, the count is incremented. Once the DLC_SEND_COUNT reaches a threshold (call-this the DLC_THRESHOLD), the DLC increments the PACING_TOKEN_COUNT by the DLC_THRESHOLD value. The DLC_SEND_COUNT is then reset to 0. As an alternative to a counting technique, a sublink DLC can implement its part of the link metered pacing mechanism by issuing the SEND_MU after each time it completes transmission of a packet from its transmit queue (rather than from a retransmit queue). If a sublink DLC goes into error recovery, it draws packets from its retransmit queue. Thus, there is a natural pacing mechanism that stops the flow of packets from MLTG to the sublink DLC when the sublink link experiences delays due to recovery. The dashed “+” curve in FIG. 3 illustrates simulation results for a link metered pacing method where bit error loss is present on one of the sublinks. As seen in FIG. 3 , RTP throughput collapses in the range of 10 −5 . The results show significant improvement over the round robin method (the solid “+” curve illustrates a reound robin scheduling method with error recovery enabled and the solid “0” illustrates a round robin scheduling method where error recovery is disabled). However, the throughput of the MLTG still falls below that of using a single sublink if the bit error rate is large enough. An optimized value of MAX_TOKENS may be utilized to improve performance, but this value still depends on statically configured link speed and propagation delay estimates. Obtaining accurate estimates may be difficult without a dynamic measurement. Also, as link quality deteriorates, the original MAX_TOKENS value is no longer optimal. SUMMARY OF THE INVENTION In view of the above discussion, it is an object of the present invention to provide improved flow control through multiple concurrent links in a network. A further object of the present invention is to account for non-congestion based losses in networks having concurrent multiple links between nodes. Yet another object of the present invention is to increase the efficiency of a group of multiple concurrent links in a network path when losses of packets on a link in the group of multiple concurrent links occurs. Still another object of the present invention is to provide a manner of scheduling packets to multiple concurrent links. Another object of the present invention is to reduce the impact on the efficiency of functional links in a group of multiple concurrent links resulting from packet losses on one of the links. These and other objects of the present invention are provided by distributing communication packets over multiple concurrent parallel links between a first node and a second node in a communication network based upon link quality information for the links. By utilizing link quality information from the links, the rate at which packets are provided to the links may be made proportional to the quality of the link, and thus, the link's ability to transmit the packet. In one embodiment, communication packets are provided to individual links of the multiple links at a packet transfer rate and link quality information for at least one link of the multiple links is obtained. The packet transfer rate to the link is reduced if the link quality information obtained for the link indicates that transmission quality of the link is below a first predefined threshold. In such a case link quality information may be bit error rate information and the transmission quality of the link is below a first predefined threshold if the link quality information indicates a bit error rate of greater than a predefined error rate. Furthermore, the quality information may be the number of errors occurring during a time interval. In this instance, the bit error rate may be estimated by dividing the number of errors occurring during a time interval by the total amount of data sent to the link during the time interval. In another embodiment, the packet transfers to a link are terminated if the link quality information received from the link indicates that transmission quality of the link is below a second predefined threshold. Where transmission quality if measured by bit error rates, the transmission quality of the a link may be below a second predefined threshold if the link quality information indicates a bit error rate of greater than a second predefined error rate. In particular embodiments of the present invention, communication packets are provided to the links by a weighted round-robin method of packet distribution. Alternatively, communication packets may be provided to individual links of the multiple links by a link metered pacing method of packet distribution. In these threshold embodiments of the present invention, the rate at which packets are provided to a link of the multiple links is based upon whether the transmission quality of the link is above or below a threshold. By decreasing the rate at which packets are provided to individual links as those links performance degrades, retry timeouts may be avoided and performance of the multiple links may be maintained. Furthermore, by providing no or only a few packets to a link if the link has too high an error rate the impact on the other links in the group of a links errors may be reduced. In an alternative embodiment fo the present invention, packets are distributed to concurrent links by obtaining link quality information for each of a plurality of the multiple links. A delay factor associated with each of the plurality of links is determined and communication packets are distributed among the plurality of links based upon the delay factor associated with each of the plurality of links. The communication packets may be distributed to the links by providing communication packets to a link of the plurality of links with the least delay. Furthermore, the delay factor may be the sum of an effective time to send and receive a packet for a link, a propagation delay for the link and an estimate of the queueing delay of the link. The effective time to send and receive a packet for a link may be determined from an estimated bit error rate for the link. Also, the bit error rate for the link may be estimated by dividing the number of errors occurring during a time interval by the total amount of data sent to the at least one link during the time interval. The estimate of the queuing delay of the link may be based upon the number of packets assigned to the link. In addition to the distribution of packets to links based upon a delay factor, communication packet transfers to a link may be terminated if the link quality information received from the a link indicates that transmission quality of a link is below a predefined threshold. By scheduling packets to links based upon the smallest delay factor the scheduler may reduce the impact of a link becoming a “lossy” link by reducing the rate at which packets are sent to that link. Furthermore, because the delay factors are calculated dynamically they automatically compensate for changes in loss rates for the links. Thus, a link which becomes lossy may recover and be useable at a later time. Also, by providing for a continuous compensation, rather than threshold oriented compensation, for loss in a link there is no need to set threshold values which may be incorrectly established. In another embodiment of the present invention, the multiple links are a High Performance Routing (HPR) Multi-Link Transmission Group (MLTG). In such an embodiment, packets may be distributed to links in the MLTG by obtaining link quality information from links in the MLTG and scheduling data packets to the links of the MLTG based on the link quality information obtained form the links. Link quality information may be obtained by obtaining a retransmit count for a specified period of time from a SEND_MU signal from a link of the MLTG. Scheduling packets to the links may be carried out by determining an estimated bit error rate for a link based upon the retransmit count of the link and a count of the total bytes sent the link over the specified period of time. The send rate to the link may then be reduced if the estimate bit error rate is above a first predefined threshold. Furthermore, the link may be disabled if the estimated bit error rate for the link is greater than a second predefined threshold. In another embodiment of the present invention, delay factors are determined for the links in the MLTG. Data packets are then scheduled to the links of the MLTG so as to schedule packets to the available link with the lowest delay factor. The delay factor may be calculated by calculating an estimated time delay for a link to transmit a packet. This time delay may be determined by solving: DELAY= PS /( LS*MLE )+ PD +( QL/ 2)/( LS*MLE ) wherein DELAY is an estimate of a delay (in seconds) that a packet experiences over the link, PS is a packet size measured in bits, LS is a link speed for the link, MLE is a measured link efficiency, PD is a propagation delay of the link and QL is an estimate of a current queue level of the link. As will further be appreciated by those of skill in the art, the present invention may be embodied as a method, apparatus or computer program product. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph of the performance of the throughput of a communication path versus the input rate to the path; FIG. 2 is a graph of efficiency of a two sublink MLTG versus bit error rate of one sublink in the MLTG utilizing a conventional round-robin scheduling method; FIG. 3 is a graph of efficiency of a two sublink MLTG utilizing a conventional link metered pacing scheduling method versus bit error rate of one sublink in the MLTG; FIG. 4 is a block diagram of a network utilizing the present invention; FIG. 5 is a flow chart illustrating one embodiment of the present invention; FIG. 6 is a flow chart illustrating a second embodiment of the present invention; FIG. 7 is a graph of efficiency versus bit error rate for a one sublink of a two sublink MLTG utilizing embodiments of the present invention; and FIG. 8 is a graph of efficiency versus bit error rate for a one sublink of a two sublink MLTG utilizing threshold and minimal delay embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. As will be appreciated by one of skill in the art, the present invention may be embodied as methods or devices. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. The present invention provides for scheduling of information packets to concurrent paths between two nodes in a communication path. The present invention is a form of “striping” where packets are “striped” across multiple links. Thus, the present invention may be thought of as intelligent striping which utilizes information about specific links to stripe data across the links. Furthermore, the present invention may be applicable to striping at higher levels such as across multiple paths or multiple connections. One example of higher level striping may be striping across multiple paths in a TCP/IP network. In such a case the packet distribution between the parallel paths or connections would be based on path or connection quality information corresponding to the link quality information dicussed herein. The present invention is described herein with respect to embodiments implementing HPR. However, as will be appreciated by those of skill in the art, the teachings of the present invention are not limited to HPR but may be applicable to any network which allows for concurrent paths between nodes. Thus, for example, in TCP/IP, multi-link PPP may benefit from scheduling packets based upon the present invention. FIG. 4 is a block diagram illustrating a network communication path utilizing the present invention. As seen in FIG. 4 , a first endpoint node 20 is connected to an intermediated node 22 . The intermediate node 22 is connected to a second intermediate node 24 by concurrent links 26 . For purposes of illustration, the concurrent links 26 are two links, however, as will be appreciated by those of skill in the art, the principles of the present invention may apply to scheduling information packets to any number of concurrent paths between two nodes. Intermediate node 24 is then connected to a second endpoint node 28 . Communications flow across the network from endpoint node to endpoint node in either direction. However, for purposes of illustration, communications will be described as originating with the first endpoint node 20 and being received by the second endpoint node 28 . Thus, an example of a communication flow would be for the first endpoint node 20 to send communication packets to the first intermediate node 22 . A scheduler 23 at the first intermediate node then distributes the communication packets among the links of the concurrent links 26 and transmits the packets to the second intermediate node 24 . The second intermediate node 24 receives the packets from the first intermediate node 22 and sends them on to the second endpoint 28 . The distribution of packets over multiple concurrent links 26 between the first node 22 and the second node 24 involves distributing communication packets to links of the multiple links based upon link quality information for the links. This distribution based upon a quality assessment of a link in the group of concurrent links 26 may be carried out in several ways. Two such ways are illustrated in FIG. 5 and FIG. 6 . The present invention will now be described with respect to FIG. 5 and FIG. 6 which are flowcharts illustrating exemplary embodiments of the present invention. It will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These program instructions may be provided to a processor to produce a machine, such that the instructions which execute on the processor create means for implementing the functions specified in the flowchart block or blocks. The computer program instructions may be executed by a processor to cause a series of operational steps to be performed by the processor to produce a computer implemented process such that the instructions which execute on the processor provide steps for implementing the functions specified in the flowchart block or blocks. Accordingly, blocks of the flowchart illustrations support combinations of means for performing the specified functions, combinations of steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by special purpose hardware-based systems which perform the specified functions or steps, or combinations of special purpose hardware and computer instructions. As seen in FIG. 5 a scheduler 23 at a first node 22 (the sending node) having multiple concurrent links 26 connecting the node to a second node 24 (the receiving node) may begin distribution of packets across the multiple links by obtaining the packets to be provided to the links (block 30 ). The scheduler 23 also obtains quality information about the links (block 32 ). The quality information may be a bit error rate for the link or it may be the number of retransmitted packets for the link or other information from which a link quality may be determined by the scheduler 23 . The quality information may be any information which allows the scheduler 23 to determine the relative efficiency of a link in comparison to the other links in the group. The scheduler 23 determines the next link to transmit information to (block 34 ) and then determines if the link quality of the link is below a first threshold (block 36 ). If the quality of the link is not below the first threshold value then the packets are transmitted to the link (block 38 ) and the scheduling of those packets is complete. If additional packets are to be transmitted (block 48 ) then the process is repeated from block 36 . If however, the link quality is below the first threshold, then the scheduler 23 determines if the link quality is below a second threshold, lower than the first threshold (block 40 ). If the link quality is not below the second threshold, then the send rate to the link is reduced (block 42 ) to the link. The scheduler 23 then determines if the link is still available at this reduced send rate (block 44 ) (i.e. at the reduced rate does the link already have a full queue of data packets). If the link is still available, then the packets are transmitted to the link at the reduced send rate (block 38 ). However, if the link is not available, then the next available link is determined (block 34 ) and the process repeated. Returning to block 40 , if the link quality of the link is below the second threshold, then the link is considered not functional and is disabled (block 46 ). Optionally, the link may be periodically monitored to determine if the link has regained functionality so that it may be reactivated and utilized in subsequent transmissions of packets. Thus, the embodiment of the present invention illustrated in FIG. 5 provides for varying the send rate to a link in a group of concurrent links by reducing the send rate to the link if the link quality, based on quality information received from the link, falls below a first threshold and disabling the link if the link quality falls below a second threshold. The specification of these threshold may vary from network to network but the first threshold will typically be established at a level such as the “cliff” illustrated in FIG. 1 . The second threshold value will typically be set at a value where degradation of one link in a group of concurrent links causes a reduction in efficiency of the other links in the group (i.e. where the throughput of the group of links is less than the sum of the normal throughput of the functioning links). In selecting available links, the scheduler 23 may utilize any method of link selection, such as round-robin, weighted round-robin, link metered pacing or other methods known to those of skill in the art. Furthermore, based upon the particular method of selection and the network architecture, the actual manner in which packets are provided to links or send rates are reduced for a link may vary. Thus, for example, the weights in a weighted round-robin approach could be revised based on link quality to alter the send rate to a link. Similarly, in a link metered pacing approach the maximum number of packets sent to a link could be reduced to reduce the send rate to the link. As these examples illustrate, there may be many ways to reduce send rates to a link and these may be architecture specific. Furthermore, while FIG. 5 illustrates the link quality assessment as integrated with the distribution of packets, as will be appreciated by those of skill in the art, the link quality assessment and establishing of send rates to a link may be separate from the distribution and simply modify the distribution parameters such that a convention distribution method is utilized with parameters optimized by a link quality assessment procedure. FIG. 6 illustrates an alternative embodiment of the present invention. As seen in FIG. 6 , a scheduler 23 at a first node 22 (the sending node) having multiple concurrent links 26 connecting the node to a second node 24 (the receiving node) may begin distribution of packets across the multiple links by obtaining the packets to be provided to the links (block 50 ). The scheduler 23 also obtains quality information about the links (block 52 ). As with the previous embodiment, the quality information may be a bit error rate for the link or it may be the number of retransmitted packets for the link or other information from which a link quality may be determined by the scheduler 23 . The scheduler 23 determines a delay factor for the links in the group (block 54 ) based on the quality information from the links. This delay factor may be determined utilizing the following equation: Delay Factor=effective time to send and receive a packet+propagation delay of the link+queuing delay of the link. The effective time to send and receive a packet may be determined from a link's bandwidth, the number of retransmitted packets for the link, the time period over which the packets were retransmitted and the number of packets sent to the link during that time period. The propagation delay for the link may be known and the queuing delay may be estimated by dividing the number of packets queued by the link by 2 and then multiplying that value by the effective time to send a packet. Other manners of determining a delay factor may be utilized, however, what should be determined is the relative rate at which the links in the group may transmit packets. The scheduler 23 then selects the link with the least delay (block 56 ) and transmits the packets over that selected link (block 58 ). If the scheduler 23 cannot transmit all of the packets over the link with the least delay the process is then repeated to select the next link for transmitting packets (block 60 ). Particular embodiments of the present invention utilized in an HPR network with a HPR MLTG will now be described as examples of the application of the principles of the present invention to a specific networking technology. Each of these embodiments modify conventional link meter pacing to improve efficiency of a MLTG. In each of these embodiments, MLTG monitors the sublink's line quality by periodically sampling the error rate. An estimate of the average error rate during a time interval can be found by dividing the number of errors that occurred during the time interval (which can be obtained from the DLC statistics) by the total amount of data sent during the interval. The correct frequency of the error measurements is primarily a function of the line speed and the bit error rate. The measurement period should be large enough to provide a statistically accurate error rate measurement. However, the measurements must be frequent enough to provide responsive feedback. For a scheduler to calculate an error rate, the scheduler should have access to a DLC's retransmission error count statistic (the scheduler for the MLTG can maintain its own count of total bytes sent over the sublink during each interval). One way to obtain link quality information such as the retransmission error count is to have the DLC send the count back to the scheduler of the MLTG with each SEND_MU signal. Therefore, each time period (called a MEASUREMENT_INTERVAL threshold), an observed error rate is computed (the MEASURED_ERROR_RATE). In a first threshold oriented embodiment, two error rate threshold values (MI_RTHR1 and MI_RTHR2) are defined and a state field (MLTG_STATE) that can be either STATE0, STATE1 or STATE2 is also defined. The values are defined as follows: STATE0: The normal operating mode of the sublink. STATE1: The sublink is lossy and should be given lower scheduling priority. STATE2: The sublink is nonfunctional. The non-functional state may either cause the link to be unused or may send a “trickle” of data to the sublink, continue to monitor statistics and once the measured error rate decreases, restore the sublink to its original scheduling priority. The link may also be temporarily stop using the sublink. However, in order to monitor the line, some sort of test data should be periodically sent over the link. For example, MLTG can send a packet with a bad destination address. The packet is dropped by the router at the other end of the link. However, the packet passes through the DLC layers allowing the DLC to update its statistics. Each MEASUREMENT_INTERVAL, the MLTG scheduler performs the Sublink_State_Transition( ) function shown below to update the NEW_MLTG_STATE and the SUBLINK_WEIGHT_CHANGE value for each sublink. Function Sublink_State_Transition  (Sublink_id) switch MLTG_STATE(Sublink_id) case (STATE0) if MEASURED_ERROR_RATE(Sublink_id) > MI_RTHR1 NEW_MLTG_STATE(Sublink_id) = STATE1 SUBLINK_WEIGHT_CHANGE(Sublink_id) = endif end case(STATE1) if MEASURED_ERROR_RATE(Sublink_id) <MI_RTHR1 NEW_MLTG_STATE(Sublink_id) = STATE0 SUBLINK_WEIGHT_CHANGE(Sublink_id) = 2 endif if MEASURE_ERROR_RATE(Sublink_id) > MI_RTHR1 and MEASURE_ERROR_RATE(sublink_id) < MI_RTHR2 do nothing else if MEASURE_ERROR_RATE(Sublink_id) > MI_RTHR2 NEW_MLTG_STATE(Sublink_id) = STATE2 SUBLINK_WEIGHT_CHANGE(Sublink_id) = 1 Set SUBLINK_WEIGHT(Sublink_id) = 0 to effectively stop using it endif end case(STATE2) if MEASURE_ERROR_RATE(Sublink_id) > MI_RTHR2 continue sending a trickle of data . . . endif if MEASURE_ERROR_RATE(Sublink_id) < MI_RTHR1 NEW_MLTG_STATE(Sublink_id) = STATE0 SUBLINK_WEIGHT_CHANGE(Sublink_id) = 0 restore SUBLINK_WEIGHT(Sublink_id) to the original relative weight end Based on the current weights (i.e., the SUBLINK_WEIGHT vector) and the SUBLINK_WEIGHT_CHANGE vector, the sublink weights can be adjusted. The function that performs the adjustment is very simple. Rather than a global assessment based on information from each sublink, a sublink weight is simply scaled based on its SUBLINK_WEIGHT_CHANGE value. Preferably, the sublink weight values have a minimum value of 2 and are factors of 2. This revision of the sublink weights results in changes in the scheduling priority of the links such that a reduction in the sublink weight causes a reduction in the number of packets sent to the link. Thus, modifying the sublink weights causes the scheduler to modify the distribution of packets to the links. In an alternative embodiment of the present invention utilizing thresholds, when the first error rate threshold is reached (MI_RTHR1), instead of modifying the weight values, the MAX_TOKENS value is reduced by ½. The DLC_THRESHOLD value does not have to be modified if the DLC issues SEND_MU signals after it receives an acknowledgment and if it has no more data to send. Reducing the MAX_TOKENS value reduces the maximum number of packets that can ever be queued in the sublink and reduces the MAX_OUT value of the DLC. Lowering the MAX_OUT value as a link experiences high packet loss may have minimal improvement on a full duplex DLC, however it can be a significant improvement for a half duplex DLC. Once the sublink moves from STATE1 back to STATE0, the MAX_TOKENS value is restored. Once the second error rate threshold is reached (MI_RTHR2), MAX_TOKENS is set to 1 allowing only a trickle of data to flow over the lossy link. As with the previous embodiment, once the error rate improves, the link's MAX_TOKENS value is restored. Alternatively, the MAX_TOKENS value could be set to 0 to completely remove the link. FIG. 7 illustrates the results of a simulation of the two threshold embodiments described above for a two link MLTG. In FIG. 7 the dashed “+” curve 72 of shows the improvement gained by dynamically updating the MAX_TOKENS value. The solid “+” line 70 is the unoptimized link metered pacing method (using a maximum token value of 7). The dashed “O” curve 74 is the result of dynamically updating the weight values. The solid “+” curve of FIG. 7 illustrates the result where once the measured error rate exceeds the MI_RTHR2_threshold, the link is removed (at least temporarily). The MI_RTHR2 error rate threshold is chosen such that MLTG stops using the full duplex link once its efficiency has been reduced to 0.1. This roughly corresponds to an increase in delay over the link by a factor of 10 which is large enough to trigger time-outs. In a delay oriented embodiment of the present invention, scheduling decisions are based on an estimate of the anticipated delay associated with sending a packet over each sublink. In such an embodiment the flow distribution of packets over the sublinks is adjusted based on a real-time link error rate measurement. The anticipated delay is based on the following definition of expected delay that is associated with sending a packet over a particular sublink (assuming fifo queuing): DELAY= PS /( LS*MLE )+ PD +( QL/ 2)/( LS*MLE ) where DELAY is an estimate of the delay (in seconds) that a packet experiences over a particular link, PS is the packet's size measured in bits, LS is the link speed measured in bits per second, MLE is the measured link efficiency which is a real number from 0 to 1, PD is the propagation delay of the link and QL is an estimate of the current queue level of a particular sublink. The measured link efficiency (MLE) can be found directly from the link statistics based on the total number of bytes sent and the total number of bytes retransmitted. Or the efficiency can be derived based on a measured error rate using an analytical model that expresses the DLC efficiency as a function of BER. The error rate is based on the number of errors divided by the total number of bytes sent. The propagation delay can be an estimate, or ideally it is measured by the link (or MLTG) at link startup time. Given that it is difficult to find sublink queue levels directly, QL can be estimated from the current queue length by assuming that the link has sent ½ the amount of data that has been assigned to it but not yet confirmed (i.e., QL is ½ the current value of the PACING_TOKEN_COUNT). The delay calculation is done by the MLTG scheduler for each packet (although the MLE is calculated each measurement interval). As the line quality deteriorates on a sublink, the delay value increases. As with the previously described embodiment, the present embodiment may dynamically adjust the MAX_TOKENS value. Such a scaling may modify a sublink's MAX_TOKENS value by scaling it each MEASUREMENT_INTERVAL by an amount proportional to the sublink's measured link efficiency (MLE). A procedure to dynamically modify the MAX_TOKENS value may be as follows: MLE = Calculate_the_MLE( ) if MAX_TOKENS * MLE < bandwidth-delay product if MLE < .35 MAX_TOKENS = MLE * ORIGINAL_MAX_TOKENS endif else MAX_TOKENS = MLE * ORIGINAL_MAX_TOKENS endif if MAX_TOKENS < 1 MAX_TOKENS = 1 endif Simulation results show that for more moderate BER levels, reducing the MAX_TOKENS value is advantageous as long as it does not effectively decrease the DLC's MAX_OUT value to less than the bandwidth delay product. Simulation results have also shown that once the MLE drops below 0.35, it is beneficial to reduce the DLC's MAX_OUT value. Utilizing the above scaling, a minimum delay link metered method would then include the following operations: (1) Set the MAX_TOKENS value to the bandwidth-delay product plus a little extra for internal delays. The DLC window size should be set to the same value, the DLC_THRESHOLD value should be set to 1. The DLC should issue a SEND_MU when any of the following conditions are true: (a) when a DLC_THRESHOLD number of packets have been acknowledged; or (b) when the DLC receives an acknowledgment, all other data has been acknowledged, and it has no more data to send. (2) Each MEASUREMENT_INTERVAL, based on DLC statistics, an estimate of current link efficiency is calculated for each sublink in the MLTG. The MAX_TOKENS value for a sublink is scaled based on the process shown above. Therefore, the MI_STATE of STATE1 of the previous embodiment no longer exists since the MAX_TOKENS is adjusted continuously. (3) Each time a packet is to be scheduled for transmission, MLTG: (a) Calculates the estimated delay to send this packet over each available link using the delay formula given above. Links that have run out of tokens are not considered available. If all links are unavailable, the packet is queued in the MLTG queue. (b) Transitions the link to the MI_STATE of STATE2 once a link's delay falls to {fraction (1/10)} the size of any other sublink delay. This either permanently or temporarily removes the sublink from the transmission group. (c) Assigns the packet to an available link which offers the minimal delay. FIG. 8 illustrates a comparison of simulation results for a two link MLTG utilizing the threshold embodiment and the delay embodiment of the present invention. The dashed “+” curve 80 represents the threshold embodiment. The solid “O” 82 curve represents the minimum delay embodiment of the present invention. FIG. 8 shows that the minimal delay embodiment is more tolerant of bit errors than the optimal link metered pacing algorithm. One advantage of the minimal delay embodiment is that it is not dependent on an optimized MAX_TOKENS value (that is based on the bandwidth-delay product). The minimal delay embodiment may dynamically optimize the MAX_TOKENS value as delay over a sublink changes. As packet loss due to bit errors occurs, the MAX_TOKENS value is dynamically reduced to the bandwidth-delay product. Once the link efficiency decreases beyond a threshold, the MAX_TOKENS is scaled to further reduce the flow over the link. The minimal delay embodiment also schedules each packet based on current conditions and availability of each sublink. Thus, the likelihood of timeouts resulting from differing delay times for a packet transmitted over differing links may be reduced. The present invention has been described with reference to links and link quality information. As used herein, the term links may refer to a single physical connection or multiple serial physical connections between two nodes which may be nonadjacent nodes in a network. Thus, hops, links, virtual circuits or paths are all encompassed by the term links as used herein. However, preferably the present invention is utilized to stripe across single hop links in a multilink transmission group. In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.

Methods, apparatus and computer program products are provided for distributing communication packets over multiple concurrent parallel links between a first node and a second node in a communication network based upon link quality information for the links. By utilizing link quality information from the links, the rate at which packets are provided to the links may be made proportional to the quality of the link, and thus, the link's ability to transmit the packet. The rate at which packets are provided to links may be reduced when error rates on a link exceed a specified threshold and eliminated when error rates exceed a higher threshold. Alternatively, timing delays from errors on a link may be used to determine a delay factor for a link and packets scheduled to the links based on the link with the lowest delay. The present invention is particularly useful in High Performance Routing Multilink Transmission Groups.

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation of U.S. patent application Ser. No. 14/056,885 filed Oct. 17, 2013, which is a continuation of U.S. patent application Ser. No. 13/930,863 filed Jun. 28, 2013, which is a continuation of U.S. patent application Ser. No. 13/619,851 filed Sep. 14, 2012, now U.S. Pat. No. 8,548,600, which is a continuation of U.S. patent application Ser. No. 12/777,892, filed May 11, 2010, which is a continuation of U.S. patent application Ser. No. 11/782,451, filed Jul. 24, 2007, now abandoned, which is a divisional of U.S. patent application Ser. No. 11/129,765, filed May 13, 2005, now U.S. Pat. No. 7,653,438, which claims the benefit of U.S. Provisional Patent Application No. 60/616,254, filed Oct. 5, 2004, and U.S. Provisional Patent Application No. 60/624,793, filed Nov. 2, 2004. U.S. patent application Ser. No. 11/129,765, filed May 13, 2005, now U.S. Pat. No. 7,653,438 is also a continuation-in-part of U.S. patent application Ser. No. 10/408,665, filed Apr. 8, 2003, now U.S. Pat. No. 7,162,303, which claims the benefit of U.S. Provisional Patent Application Nos. (a) 60/370,190, filed Apr. 8, 2002; (b) 60/415,575, filed Oct. 3, 2002; and (c) 60/442,970, filed Jan. 29, 2003. The disclosures of these applications are incorporated herein by reference in their entireties. INCORPORATION BY REFERENCE All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. TECHNICAL FIELD The present invention relates to methods and apparatus for renal neuromodulation. More particularly, the present invention relates to methods and apparatus for achieving renal neuromodulation via a pulsed electric field and/or electroporation or electrofusion. BACKGROUND Congestive Heart Failure (“CHF”) is a condition that occurs when the heart becomes damaged and reduces blood flow to the organs of the body. If blood flow decreases sufficiently, kidney function becomes impaired and results in fluid retention, abnormal hormone secretions and increased constriction of blood vessels. These results increase the workload of the heart and further decrease the capacity of the heart to pump blood through the kidney and circulatory system. This reduced capacity further reduces blood flow to the kidney, which in turn further reduces the capacity of the heart. It is believed that progressively decreasing perfusion of the kidney is a principal non-cardiac cause perpetuating the downward spiral of CHF. Moreover, the fluid overload and associated clinical symptoms resulting from these physiologic changes are predominant causes for excessive hospital admissions, terrible quality of life and overwhelming costs to the health care system due to CHF. While many different diseases may initially damage the heart, once present, CHF is split into two types: Chronic CHF and Acute (or Decompensated-Chronic) CHF. Chronic Congestive Heart Failure is a longer term, slowly progressive, degenerative disease. Over years, chronic congestive heart failure leads to cardiac insufficiency. Chronic CHF is clinically categorized by the patient's ability to exercise or perform normal activities of daily living (such as defined by the New York Heart Association Functional Class). Chronic CHF patients are usually managed on an outpatient basis, typically with drugs. Chronic CHF patients may experience an abrupt, severe deterioration in heart function, termed Acute Congestive Heart Failure, resulting in the inability of the heart to maintain sufficient blood flow and pressure to keep vital organs of the body alive. These Acute CHF deteriorations can occur when extra stress (such as an infection or excessive fluid overload) significantly increases the workload on the heart in a stable chronic CHF patient. In contrast to the stepwise downward progression of chronic CHF, a patient suffering acute CHF may deteriorate from even the earliest stages of CHF to severe hemodynamic collapse. In addition, Acute CHF can occur within hours or days following an Acute Myocardial Infarction (“AMI”), which is a sudden, irreversible injury to the heart muscle, commonly referred to as a heart attack. As mentioned, the kidneys play a significant role in the progression of CHF, as well as in Chronic Renal Failure (“CRF”), End-Stage Renal Disease (“ESRD”), hypertension (pathologically high blood pressure) and other cardio-renal diseases. The functions of the kidney can be summarized under three broad categories: filtering blood and excreting waste products generated by the body's metabolism; regulating salt, water, electrolyte and acid-base balance; and secreting hormones to maintain vital organ blood flow. Without properly functioning kidneys, a patient will suffer water retention, reduced urine flow and an accumulation of waste toxins in the blood and body. These conditions resulting from reduced renal function or renal failure (kidney failure) are believed to increase the workload of the heart. In a CHF patient, renal failure will cause the heart to further deteriorate as the water build-up and blood toxins accumulate due to the poorly functioning kidneys and, in turn, cause the heart further harm. The primary functional unit of the kidneys that is involved in urine formation is called the “nephron”. Each kidney consists of about one million nephrons. The nephron is made up of a glomerulus and its tubules, which can be separated into a number of sections: the proximal tubule, the medullary loop (loop of Henle), and the distal tubule. Each nephron is surrounded by different types of cells that have the ability to secrete several substances and hormones (such as renin and erythropoietin). Urine is formed as a result of a complex process starting with the filtration of plasma water from blood into the glomerulus. The walls of the glomerulus are freely permeable to water and small molecules but almost impermeable to proteins and large molecules. Thus, in a healthy kidney, the filtrate is virtually free of protein and has no cellular elements. The filtered fluid that eventually becomes urine flows through the tubules. The final chemical composition of the urine is determined by the secretion into, and re-absorption of substances from, the urine required to maintain homeostasis. Receiving about 20% of cardiac output, the two kidneys filter about 125 ml of plasma water per minute. Filtration occurs because of a pressure gradient across the glomerular membrane. The pressure in the arteries of the kidney pushes plasma water into the glomerulus causing filtration. To keep the Glomerulur Filtration Rate (“GFR”) relatively constant, pressure in the glomerulus is held constant by the constriction or dilatation of the afferent and efferent arterioles, the muscular walled vessels leading to and from each glomerulus. In a CHF patient, the heart will progressively fail, and blood flow and pressure will drop in the patient's circulatory system. During acute heart failure, short-term compensations serve to maintain perfusion to critical organs, notably the brain and the heart that cannot survive prolonged reduction in blood flow. However, these same responses that initially aid survival during acute heart failure become deleterious during chronic heart failure. A combination of complex mechanisms contribute to deleterious fluid overload in CHF. As the heart fails and blood pressure drops, the kidneys cannot function and become impaired due to insufficient blood pressure for perfusion. This impairment in renal function ultimately leads to the decrease in urine output. Without sufficient urine output, the body retains fluids, and the resulting fluid overload causes peripheral edema (swelling of the legs), shortness of breath (due to fluid in the lungs), and fluid retention in the abdomen, among other undesirable conditions in the patient. In addition, the decrease in cardiac output leads to reduced renal blood flow, increased neurohormonal stimulus, and release of the hormone renin from the juxtaglomerular apparatus of the kidney. This results in avid retention of sodium and, thus, volume expansion. Increased renin results in the formation of angiotensin, a potent vasoconstrictor. Heart failure and the resulting reduction in blood pressure also reduce the blood flow and perfusion pressure through organs in the body other than the kidneys. As they suffer reduced blood pressure, these organs may become hypoxic, resulting in a metabolic acidosis that reduces the effectiveness of pharmacological therapy and increases a risk of sudden death. This spiral of deterioration that physicians observe in heart failure patients is believed to be mediated, at least in part, by activation of a subtle interaction between heart function and kidney function, known as the renin-angiotensin system. Disturbances in the heart's pumping function results in decreased cardiac output and diminished blood flow. The kidneys respond to the diminished blood flow as though the total blood volume was decreased, when in fact the measured volume is normal or even increased. This leads to fluid retention by the kidneys and formation of edema, thereby causing the fluid overload and increased stress on the heart. Systemically, CHF is associated with an abnormally elevated peripheral vascular resistance and is dominated by alterations of the circulation resulting from an intense disturbance of sympathetic nervous system function. Increased activity of the sympathetic nervous system promotes a downward vicious cycle of increased arterial vasoconstriction (increased resistance of vessels to blood flow) followed by a further reduction of cardiac output, causing even more diminished blood flow to the vital organs. In CHF via the previously explained mechanism of vasoconstriction, the heart and circulatory system dramatically reduce blood flow to the kidneys. During CHF, the kidneys receive a command from higher neural centers via neural pathways and hormonal messengers to retain fluid and sodium in the body. In response to stress on the heart, the neural centers command the kidneys to reduce their filtering functions. While in the short term, these commands can be beneficial, if these commands continue over hours and days they can jeopardize the person's life or make the person dependent on artificial kidney for life by causing the kidneys to cease functioning. When the kidneys do not fully filter the blood, a huge amount of fluid is retained in the body, which results in bloating (fluid retention in tissues) and increases the workload of the heart. Fluid can penetrate into the lungs, and the patient becomes short of breath. This odd and self-destructive phenomenon is most likely explained by the effects of normal compensatory mechanisms of the body that improperly perceive the chronically low blood pressure of CHF as a sign of temporary disturbance, such as bleeding. In an acute situation, the body tries to protect its most vital organs, the brain and the heart, from the hazards of oxygen deprivation. Commands are issued via neural and hormonal pathways and messengers. These commands are directed toward the goal of maintaining blood pressure to the brain and heart, which are treated by the body as the most vital organs. The brain and heart cannot sustain low perfusion for any substantial period of time. A stroke or a cardiac arrest will result if the blood pressure to these organs is reduced to unacceptable levels. Other organs, such as the kidneys, can withstand somewhat longer periods of ischemia without suffering long-term damage. Accordingly, the body sacrifices blood supply to these other organs in favor of the brain and the heart. The hemodynamic impairment resulting from CHF activates several neurohormonal systems, such as the renin-angiotensin and aldosterone system, sympatho-adrenal system and vasopressin release. As the kidneys suffer from increased renal vasoconstriction, the GFR drops, and the sodium load in the circulatory system increases. Simultaneously, more renin is liberated from the juxtaglomerular of the kidney. The combined effects of reduced kidney functioning include reduced glomerular sodium load, an aldosterone-mediated increase in tubular reabsorption of sodium, and retention in the body of sodium and water. These effects lead to several signs and symptoms of the CHF condition, including an enlarged heart, increased systolic wall stress, an increased myocardial oxygen demand, and the formation of edema on the basis of fluid and sodium retention in the kidney. Accordingly, sustained reduction in renal blood flow and vasoconstriction is directly responsible for causing the fluid retention associated with CHF. CHF is progressive, and as of now, not curable. The limitations of drug therapy and its inability to reverse or even arrest the deterioration of CHF patients are clear. Surgical therapies are effective in some cases, but limited to the end-stage patient population because of the associated risk and cost. Furthermore, the dramatic role played by kidneys in the deterioration of CHF patients is not adequately addressed by current surgical therapies. The autonomic nervous system is recognized as an important pathway for control signals that are responsible for the regulation of body functions critical for maintaining vascular fluid balance and blood pressure. The autonomic nervous system conducts information in the form of signals from the body's biologic sensors such as baroreceptors (responding to pressure and volume of blood) and chemoreceptors (responding to chemical composition of blood) to the central nervous system via its sensory fibers. It also conducts command signals from the central nervous system that control the various innervated components of the vascular system via its motor fibers. Experience with human kidney transplantation provided early evidence of the role of the nervous system in kidney function. It was noted that after transplant, when all the kidney nerves were totally severed, the kidney increased the excretion of water and sodium. This phenomenon was also observed in animals when the renal nerves were cut or chemically destroyed. The phenomenon was called “denervation diuresis” since the denervation acted on a kidney similar to a diuretic medication. Later the “denervation diuresis” was found to be associated with vasodilatation of the renal arterial system that led to increased blood flow through the kidney. This observation was confirmed by the observation in animals that reducing blood pressure supplying the kidneys reversed the “denervation diuresis”. It was also observed that after several months passed after the transplant surgery in successful cases, the “denervation diuresis” in transplant recipients stopped and the kidney function returned to normal. Originally, it was believed that the “renal diuresis” was a transient phenomenon and that the nerves conducting signals from the central nervous system to the kidney were not essential to kidney function. Later discoveries suggested that the renal nerves had a profound ability to regenerate and that the reversal of “denervation diuresis” could be attributed to the growth of new nerve fibers supplying the kidneys with necessary stimuli. Another body of research focused on the role of the neural control of secretion of the hormone renin by the kidney. As was discussed previously, renin is a hormone responsible for the “vicious cycle” of vasoconstriction and water and sodium retention in heart failure patients. It was demonstrated that an increase or decrease in renal sympathetic nerve activity produced parallel increases and decreases in the renin secretion rate by the kidney, respectively. In summary, it is known from clinical experience and the large body of animal research that an increase in renal sympathetic nerve activity leads to vasoconstriction of blood vessels supplying the kidney, decreased renal blood flow, decreased removal of water and sodium from the body, and increased renin secretion. It is also known that reduction of sympathetic renal nerve activity, e.g., via denervation, may reverse these processes. It has been established in animal models that the heart failure condition results in abnormally high sympathetic stimulation of the kidney. This phenomenon was traced back to the sensory nerves conducting signals from baroreceptors to the central nervous system. Baroreceptors are present in the different locations of the vascular system. Powerful relationships exist between baroreceptors in the carotid arteries (supplying the brain with arterial blood) and sympathetic nervous stimulus to the kidneys. When arterial blood pressure was suddenly reduced in experimental animals with heart failure, sympathetic tone increased. Nevertheless, the normal baroreflex likely is not solely responsible for elevated renal nerve activity in chronic CHF patients. If exposed to a reduced level of arterial pressure for a prolonged time, baroreceptors normally “reset”, i.e., return to a baseline level of activity, until a new disturbance is introduced. Therefore, it is believed that in chronic CHF patients, the components of the autonomic-nervous system responsible for the control of blood pressure and the neural control of the kidney function become abnormal. The exact mechanisms that cause this abnormality are not fully understood, but its effects on the overall condition of the CHF patients are profoundly negative. End-Stage Renal Disease is another condition at least partially controlled by renal neural activity. There has been a dramatic increase in patients with ESRD due to diabetic nephropathy, chronic glomerulonephritis and uncontrolled hypertension. Chronic Renal Failure slowly progresses to ESRD. CRF represents a critical period in the evolution of ESRD. The signs and symptoms of CRF are initially minor, but over the course of 2-5 years, become progressive and irreversible. While some progress has been made in combating the progression to, and complications of, ESRD, the clinical benefits of existing interventions remain limited. It has been known for several decades that renal diseases of diverse etiology (hypotension, infection, trauma, autoimmune disease, etc.) can lead to the syndrome of CRF characterized by systemic hypertension, proteinuria (excess protein filtered from the blood into the urine) and a progressive decline in GFR ultimately resulting in ESRD. These observations suggest that CRF progresses via a common pathway of mechanisms and that therapeutic interventions inhibiting this common pathway may be successful in slowing the rate of progression of CRF irrespective of the initiating cause. To start the vicious cycle of CRF, an initial insult to the kidney causes loss of some nephrons. To maintain normal GFR, there is an activation of compensatory renal and systemic mechanisms resulting in a state of hyperfiltration in the remaining nephrons. Eventually, however, the increasing numbers of nephrons “overworked” and damaged by hyperfiltration are lost. At some point, a sufficient number of nephrons are lost so that normal GFR can no longer be maintained. These pathologic changes of CRF produce worsening systemic hypertension, thus high glomerular pressure and increased hyperfiltration. Increased glomerular hyperfiltration and permeability in CRF pushes an increased amount of protein from the blood, across the glomerulus and into the renal tubules. This protein is directly toxic to the tubules and leads to further loss of nephrons, increasing the rate of progression of CRF. This vicious cycle of CRF continues as the GFR drops with loss of additional nephrons leading to further hyperfiltration and eventually to ESRD requiring dialysis. Clinically, hypertension and excess protein filtration have been shown to be two major determining factors in the rate of progression of CRF to ESRD. Though previously clinically known, it was not until the 1980s that the physiologic link between hypertension, proteinuria, nephron loss and CRF was identified. In 1990s the role of sympathetic nervous system activity was elucidated. Afferent signals arising from the damaged kidneys due to the activation of mechanoreceptors and chemoreceptors stimulate areas of the brain responsible for blood pressure control. In response, the brain increases sympathetic stimulation on the systemic level, resulting in increased blood pressure primarily through vasoconstriction of blood vessels. When elevated sympathetic stimulation reaches the kidney via the efferent sympathetic nerve fibers, it produces major deleterious effects in two forms. The kidneys are damaged by direct renal toxicity from the release of sympathetic neurotransmitters (such as norepinephrine) in the kidneys independent of the hypertension. Furthermore, secretion of renin that activates Angiotensin II is increased, which increases systemic vasoconstriction and exacerbates hypertension. Over time, damage to the kidneys leads to a further increase of afferent sympathetic signals from the kidney to the brain. Elevated Angiotensin II further facilitates internal renal release of neurotransmitters. The feedback loop is therefore closed, which accelerates deterioration of the kidneys. In view of the foregoing, it would be desirable to provide methods and apparatus for the treatment of congestive heart failure, renal disease, hypertension and/or other cardio-renal diseases via renal neuromodulation and/or denervation. SUMMARY The present invention provides methods and apparatus for renal neuromodulation (e.g., denervation) using a pulsed electric field (PEF). Several aspects of the invention apply a pulsed electric field to effectuate electroporation and/or electrofusion in renal nerves, other neural fibers that contribute to renal neural function, or other neural features. Several embodiments of the invention are intravascular devices for inducing renal neuromodulation. The apparatus and methods described herein may utilize any suitable electrical signal or field parameters that achieve neuromodulation, including denervation, and/or otherwise create an electroporative and/or electrofusion effect. For example, the electrical signal may incorporate a nanosecond pulsed electric field (nsPEF) and/or a PEF for effectuating electroporation. One specific embodiment comprises applying a first course of PEF electroporation followed by a second course of nsPEF electroporation to induce apoptosis in any cells left intact after the PEF treatment, or vice versa. An alternative embodiment comprises fusing nerve cells by applying a PEF in a manner that is expected to reduce or eliminate the ability of the nerves to conduct electrical impulses. When the methods and apparatus are applied to renal nerves and/or other neural fibers that contribute to renal neural functions, this present inventors believe that urine output will increase and/or blood pressure will be controlled in a manner that will prevent or treat CHF, hypertension, renal system diseases, and other renal anomalies. Several aspects of particular embodiments can achieve such results by selecting suitable parameters for the PEFs and/or nsPEFs. Pulsed electric field parameters can include, but are not limited to, field strength, pulse width, the shape of the pulse, the number of pulses and/or the interval between pulses (e.g., duty cycle). Suitable field strengths include, for example, strengths of up to about 10,000 V/cm. Suitable pulse widths include, for example, widths of up to about 1 second. Suitable shapes of the pulse waveform include, for example, AC waveforms, sinusoidal waves, cosine waves, combinations of sine and cosine waves, DC waveforms, DC-shifted AC waveforms, RF waveforms, square waves, trapezoidal waves, exponentially-decaying waves, combinations thereof, etc. Suitable numbers of pulses include, for example, at least one pulse. Suitable pulse intervals include, for example, intervals less than about 10 seconds. Any combination of these parameters may be utilized as desired. These parameters are provided for the sake of illustration and should in no way be considered limiting. Additional and alternative waveform parameters will be apparent. Several embodiments are directed to percutaneous intravascular systems for providing long-lasting denervation to minimize acute myocardial infarct (“AMI”) expansion and for helping to prevent the onset of morphological changes that are affiliated with congestive heart failure. For example, one embodiment of the invention comprises treating a patient for an infarction, e.g., via coronary angioplasty and/or stenting, and performing an intra-arterial pulsed electric field renal denervation procedure under fluoroscopic guidance. Alternatively, PEF therapy could be delivered in a separate session soon after the AMI had been stabilized. Renal neuromodulation also may be used as an adjunctive therapy to renal surgical procedures. In these embodiments, the anticipated increase in urine output and/or control of blood pressure provided by the renal PEF therapy is expected to reduce the load on the heart to inhibit expansion of the infarct and prevent CHF. Several embodiments of intravascular pulsed electric field systems described herein may denervate or reduce the activity of the renal nervous supply immediately post-infarct, or at any time thereafter, without leaving behind a permanent implant in the patient. These embodiments are expected to increase urine output and/or control blood pressure for a period of several months during which the patient's heart can heal. If it is determined that repeat and/or chronic neuromodulation would be beneficial after this period of healing, renal PEF treatment can be repeated as needed. In addition to efficaciously treating AMI, several embodiments of systems described herein are also expected to treat CHF, hypertension, renal failure, and other renal or cardio-renal diseases influenced or affected by increased renal sympathetic nervous activity. For example, the systems may be used to treat CHF at any time by advancing the PEF system to a treatment site via a vascular structure and then delivering a PEF therapy to the treatment site. This may, for example, modify a level of fluid offload. Embodiments of intravascular PEF systems described herein may be used similarly to angioplasty or electrophysiology catheters which are well known in the art. For example, arterial access may be gained through a standard Seldinger Technique, and an arterial sheath optionally may be placed to provide catheter access. A guidewire may be advanced through the vasculature and into the renal artery of the patient, and then an intravascular PEF may be advanced over the guidewire and/or through the sheath into the renal artery. The sheath optionally may be placed before inserting the PEF catheter or advanced along with the PEF catheter such that the sheath partially or completely covers the catheter. Alternatively, the PEF catheter may be advanced directly through the vasculature without the use of a guide wire and/or introduced and advanced into the vasculature without a sheath. In addition to arterial placement, the PEF system may be placed within a vein. Venous access may, for example, be achieved via a jugular approach. PEF systems may be utilized, for example, within the renal artery, within the renal vein or within both the renal artery and the renal vein to facilitate more complete denervation. After the PEF catheter is positioned within the vessel at a desired location with respect to the target neurons, it is stabilized within the vessel (e.g., braced against the vessel wall) and energy is delivered to the target nerve or neurons. In one variation, pulsed RF energy is delivered to the target to create a non-thermal nerve block, reduce neural signaling, or otherwise modulate neural activity. Alternatively or additionally, cooling, cryogenic, thermal RF, thermal or non-thermal microwave, focused or unfocused ultrasound, thermal or non-thermal DC, as well as any combination thereof, may be employed to reduce or otherwise control neural signaling. In still other embodiments of the invention, other non-renal neural structures may be targeted from within arterial or venous conduits in addition to or in lieu of renal neural structures. For instance, a PEF catheter can be navigated through the aorta or the vena cava and brought into apposition with various neural structures to treat other conditions or augment the treatment of renal-cardiac conditions. For example, nerve bodies of the lumbar sympathetic chain may be accessed and modulated, blocked or ablated, etc., in this manner. Several embodiments of the PEF systems may completely block or denervate the target neural structures, or the PEF systems may otherwise modulate the renal nervous activity. As opposed to a full neural blockade such as denervation, other neuromodulation produces a less-than-complete change in the level of renal nervous activity between the kidney(s) and the rest of the body. Accordingly, varying the pulsed electric field parameters will produce different effects on the nervous activity. In one embodiment of an intravascular pulsed electric field system, the device includes one or more electrodes that are configured to physically contact a target region of a renal vasculature for delivery of a pulsed electric field. For example, the device can comprise a catheter having an expandable helical section and one or more electrodes at the helical section. The catheter may be positioned in the renal vasculature while in a low profile configuration. The expandable section can then be expanded to contact the inner surface of the vessel wall. Alternatively, the catheter can have one or more expandable helical electrodes. For example, first and second expandable electrodes may be positioned within the vessel at a desired distance from one another to provide an active electrode and a return electrode. The expandable electrodes may comprise shape-memory materials, inflatable balloons, expandable meshes, linkage systems and other types of devices that can expand in a controlled manner. Suitable expandable linkage systems include expandable baskets, having a plurality of shape-memory wires or slotted hypotubes, and/or expandable rings. Additionally, the expandable electrodes may be point contact electrodes arranged along a balloon portion of a catheter. Other embodiments of pulsed electric field systems include electrodes that do not physically contact the vessel wall. RF energy, both traditional thermal energy and relatively non-thermal pulsed RF, are examples of pulsed electric fields that can be conducted into tissue to be treated from a short distance away from the tissue itself. Other types of pulsed electric fields can also be used in situations in which the electrodes do not physically contact the vessel wall. As such, the pulsed electric fields can be applied directly to the nerve via physical contact between the electrode contacts and the vessel wall or other tissue, or the pulsed electric fields can be applied indirectly to the nerve without physically contacting the electrode contacts with the vessel wall. The term “nerve contact” accordingly includes physical contact of a system element with the nerve and/or tissue proximate to the nerve, and also electrical contact alone without physically contacting the nerve or tissue. To indirectly apply the pulsed electrical field, the device has a centering element configured to position the electrodes in a central region of the vessel or otherwise space the electrodes apart from the vessel wall. The centering element may comprise, for example, a balloon or an expandable basket. One or more electrodes may be positioned on a central shaft of the centering element—either longitudinally aligned with the element or positioned on either side of the element. When utilizing a balloon catheter, the inflated balloon may act as an insulator of increased impedance for orienting or directing a pulsed electric field along a desired electric flow path. As will be apparent, alternative insulators may be utilized. In another embodiment of the system, a combination apparatus includes an intravascular catheter having a first electrode configured to physically contact the vessel wall and a second electrode configured to be positioned within the vessel but spaced apart from the vessel wall. For example, an expandable helical electrode may be used in combination with a centrally-disposed electrode to provide such a bipolar electrode pair. In yet another embodiment, a radial position of one or more electrodes relative to a vessel wall may be altered dynamically to focus the pulsed electric field delivered by the electrode(s). In still another variation, the electrodes may be configured for partial or complete passage across the vessel wall. For example, the electrode(s) may be positioned within the renal vein, then passed across the wall of the renal vein into the perivascular space such that they at least partially encircle the renal artery and/or vein prior to delivery of a pulsed electric field. Bipolar embodiments of the present invention may be configured for dynamic movement or operation relative to a spacing between the active and ground electrodes to achieve treatment over a desired distance, volume or other dimension. For example, a plurality of electrodes may be arranged such that a bipolar pair of electrodes can move longitudinally relative to each other for adjusting the separation distance between the electrodes and/or for altering the location of treatment. One specific embodiment includes a first electrode coupled to a catheter and a moveable second electrode that can move through a lumen of the catheter. In alternative embodiments, a first electrode can be attached to a catheter and a second electrode can be attached to an endoluminally-delivered device such that the first and second electrodes may be repositioned relative to one another to alter a separation distance between the electrodes. Such embodiments may facilitate treatment of a variety of renal vasculature anatomies. Any of the embodiments of the present invention described herein optionally may be configured for infusing agents into the treatment area before, during or after energy application. The infused agents can be selected to enhance or modify the neuromodulatory effect of the energy application. The agents can also protect or temporarily displace non-target cells, and/or facilitate visualization. Several embodiments of the present invention may comprise detectors or other elements that facilitate identification of locations for treatment and/or that measure or confirm the success of treatment. For example, the system can be configured to also deliver stimulation waveforms and monitor physiological parameters known to respond to stimulation of the renal nerves. Based on the results of the monitored parameters, the system can determine the location of renal nerves and/or whether denervation has occurred. Detectors for monitoring of such physiological responses include, for example, Doppler elements, thermocouples, pressure sensors, and imaging modalities (e.g., fluoroscopy, intravascular ultrasound, etc.). Alternatively, electroporation may be monitored directly using, for example, Electrical Impedance Tomography (“EIT”) or other electrical impedance measurements. Additional monitoring techniques and elements will be apparent. Such detector(s) may be integrated with the PEF systems or they may be separate elements. Still other specific embodiments include electrodes configured to align the electric field with the longer dimension of the target cells. For instance, nerve cells tend to be elongate structures with lengths that greatly exceed their lateral dimensions (e.g., diameter). By aligning an electric field so that the directionality of field propagation preferentially affects the longitudinal aspect of the cell rather than the lateral aspect of the cell, it is expected that lower field strengths can to be used to kill or disable target cells. This is expected to conserve the battery life of implantable devices, reduce collateral effects on adjacent structures, and otherwise enhance the ability to modulate the neural activity of target cells. Other embodiments of the invention are directed to applications in which the longitudinal dimensions of cells in tissues overlying or underlying the nerve are transverse (e.g., orthogonal or otherwise at an angle) with respect to the longitudinal direction of the nerve cells. Another aspect of these embodiments is to align the directionality of the PEF such that the field aligns with the longer dimensions of the target cells and the shorter dimensions of the non-target cells. More specifically, arterial smooth muscle cells are typically elongate cells which surround the arterial circumference in a generally spiraling orientation so that their longer dimensions are circumferential rather than running longitudinally along the artery. Nerves of the renal plexus, on the other hand, run along the outside of the artery generally in the longitudinal direction of the artery. Therefore, applying a PEF which is generally aligned with the longitudinal direction of the artery is expected to preferentially cause electroporation in the target nerve cells without affecting at least some of the non-target arterial smooth muscle cells to the same degree. This may enable preferential denervation of nerve cells (target cells) in the adventitia or periarterial region from an intravascular device without affecting the smooth muscle cells of the vessel to an undesirable extent. BRIEF DESCRIPTION OF THE DRAWINGS Several embodiments of the present invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: FIG. 1 is a schematic view illustrating human renal anatomy. FIG. 2 is a schematic detail view showing the location of the renal nerves relative to the renal artery. FIGS. 3A and 3B are schematic side- and end-views, respectively, illustrating a direction of electrical current flow for selectively affecting renal nerves. FIG. 4 is a schematic side-view, partially in section, of an intravascular catheter having a plurality of electrodes in accordance with one embodiment of the invention. FIG. 5 is a schematic side-view, partially in section, of an intravascular device having a pair of expanding helical electrodes arranged at a desired distance from one another in accordance with another embodiment of the invention. FIG. 6 is a schematic side-view, partially in section, of an intravascular device having a first electrode on an expandable balloon, and a second electrode on a catheter shaft in accordance with another embodiment of the invention. FIG. 7 is a schematic side-view, partially in section, of an intravascular device having an expanding first electrode delivered through the lumen of a catheter and a complementary second electrode carried by the catheter in accordance with another embodiment of the invention. FIG. 8 is a schematic side-view, partially in section, of an intravascular device having an expandable basket and a plurality of electrodes at the basket in accordance with another embodiment of the invention. FIG. 9 is a schematic detail view of the apparatus of FIG. 8 illustrating one embodiment of the electrodes in accordance with another embodiment of the invention. FIG. 10 is a schematic side-view, partially in section, of an intravascular device having expandable ring electrodes for contacting the vessel wall and an optional insulation element in accordance with another embodiment of the invention. FIGS. 11A-11C are schematic detail views of embodiments of different windings for the ring electrodes of FIG. 10 . FIG. 12 is a schematic side-view, partially in section, of an intravascular device having ring electrodes of FIG. 10 with the windings shown in FIGS. 11A-11C . FIG. 13 is a schematic side-view, partially in section, of an intravascular device having a ring electrode and a luminally-delivered electrode in accordance with another embodiment of the invention. FIG. 14 is a schematic side-view, partially in section, of an intravascular device having a balloon catheter and expandable point contact electrodes arranged proximally and distally of the balloon in accordance with another embodiment of the invention. FIG. 15 is a schematic side-view of an intravascular device having a balloon catheter and electrodes arranged proximally and distally of the balloon in accordance with another embodiment of the invention. FIGS. 16A and 16B are schematic side-views, partially in section, illustrating stages of a method of using the apparatus of FIG. 15 in accordance with an embodiment of the invention. FIG. 17 is a schematic side-view of an intravascular device having a balloon catheter and a plurality of dynamically operable electrodes in accordance with another embodiment of the invention. FIG. 18 is a schematic side-view of an intravascular device having a distal electrode deployed through a lumen of the balloon catheter in accordance with another embodiment of the invention. FIGS. 19A and 19B are side-views, partially in section, illustrating methods of using the intravascular device shown in FIG. 18 to modulate renal neural activity in patients with various renal vasculatures. FIG. 20 is a side view, partially in section, illustrating an intravascular device having a plurality of electrodes arranged along the shaft of, and in line with, a centering element in accordance with another embodiment of the invention. FIG. 21 is a side-view, partially in section, illustrating an intravascular device having electrodes configured for dynamic radial repositioning to facilitate focusing of a pulsed electric field in accordance with another embodiment of the invention. FIG. 22 is a side-view, partially in section, of an intravascular device having an infusion/aspiration catheter in accordance with another embodiment of the invention. FIGS. 23A-23C are, respectively, a side-view, partially in section, and cross-sectional views along section line A-A of FIG. 23A , illustrating a method of using an intravascular device in accordance with an embodiment of the invention configured for passage of electrode(s) at least partially across the vessel wall. FIGS. 24A and 24B are side-views, partially in section, illustrating an intravascular device having detectors for measuring or monitoring treatment efficacy in accordance with another embodiment of the invention. DETAILED DESCRIPTION A. Overview The present invention relates to methods and apparatus for renal neuromodulation and/or other neuromodulation. More particularly, the present invention relates to methods and apparatus for renal neuromodulation using a pulsed electric field to effectuate electroporation or electrofusion. As used herein, electroporation and electropermeabilization are methods of manipulating the cell membrane or intracellular apparatus. For example, short high-energy pulses cause pores to open in cell membranes. The extent of porosity in the cell membrane (e.g., size and number of pores) and the duration of the pores (e.g., temporary or permanent) are a function of the field strength, pulse width, duty cycle, field orientation, cell type and other parameters. In general, pores will generally close spontaneously upon termination of lower strength fields or shorter pulse widths (herein defined as “reversible electroporation”). Each cell type has a critical threshold above which pores do not close such that pore formation is no longer reversible; this result is defined as “irreversible electroporation,” “irreversible breakdown” or “irreversible damage.” At this point, the cell membrane ruptures and/or irreversible chemical imbalances caused by the high porosity occur. Such high porosity can be the result of a single large hole and/or a plurality of smaller holes. Certain types of electroporation energy parameters also appropriate for use in renal neuromodulation are high voltage pulses with a duration in the sub-microsecond range (nanosecond pulsed electric fields, or nsPEF) which may leave the cellular membrane intact, but alter the intracellular apparatus or function of the cell in ways which cause cell death or disruption. Certain applications of nsPEF have been shown to cause cell death by inducing apoptosis, or programmed cell death, rather than acute cell death. Also, the term “comprising” is used throughout to mean including at least the recited feature such that any greater number of the same feature and/or additional types features are not precluded. Several embodiments of the present invention provide intravascular devices for inducing renal neuromodulation, such as a temporary change in target nerves that dissipates over time, continuous control over neural function, and/or denervation. The apparatus and methods described herein may utilize any suitable electrical signal or field parameters, e.g., any electric field, that will achieve the desired neuromodulation (e.g., electroporative effect). To better understand the structures of the intravascular devices and the methods of using these devices for neuromodulation, it is useful to understand the renal anatomy in humans. B. Selected Embodiments of Methods for Neuromodulation With reference now to FIG. 1 , the human renal anatomy includes kidneys K that are supplied with oxygenated blood by renal arteries RA, which are connected to the heart by the abdominal aorta AA. Deoxygenated blood flows from the kidneys to the heart via renal veins RV and the inferior vena cava IVC. FIG. 2 illustrates a portion of the renal anatomy in greater detail. More specifically, the renal anatomy also includes renal nerves RN extending longitudinally along the lengthwise dimension L of renal artery RA generally within the adventitia of the artery. The renal artery RA has smooth muscle cells SMC that surround the arterial circumference spiral around the angular axis θ of the artery, i.e., around the circumference of the artery. The smooth muscle cells of the renal artery accordingly have a lengthwise or longer dimension extending transverse (i.e., non-parallel) to the lengthwise dimension of the renal artery. The misalignment of the lengthwise dimensions of the renal nerves and the smooth muscle cells is defined as “cellular misalignment.” Referring to FIGS. 3A and 3B , the cellular misalignment of the renal nerves and the smooth muscle cells may be exploited to selectively affect renal nerve cells with reduced effect on smooth muscle cells. More specifically, because larger cells require less energy to exceed the irreversibility threshold of electroporation, several embodiments of electrodes of the present invention are configured to align at least a portion of an electric field generated by the electrodes with or near the longer dimensions of the cells to be affected. In specific embodiments, the intravascular device has electrodes configured to create an electrical field aligned with or near the lengthwise dimension of the renal artery RA to affect renal nerves RN. By aligning an electric field so that the field preferentially affects the lengthwise aspect of the cell rather than the diametric or radial aspect of the cell, lower field strengths may be used to necrose cells. As mentioned above, this is expected to reduce power consumption and mitigate effects on non-target cells in the electric field. Similarly, the lengthwise or longer dimensions of tissues overlying or underlying the target nerve are orthogonal or otherwise off-axis (e.g., transverse) with respect to the longer dimensions of the nerve cells. Thus, in addition to aligning the PEF with the lengthwise or longer dimensions of the target cells, the PEF may propagate along the lateral or shorter dimensions of the non-target cells (i.e. such that the PEF propagates at least partially out of alignment with non-target smooth muscle cells SMC). Therefore, as seen in FIGS. 3A and 3B , applying a PEF with propagation lines Li generally aligned with the longitudinal dimension L of the renal artery RA is expected to preferentially cause electroporation, electrofusion, denervation or other neuromodulation in cells of the target renal nerves RN without unduly affecting the non-target arterial smooth muscle cells SMC. The pulsed electric field may propagate in a single plane along the longitudinal axis of the renal artery, or may propagate in the longitudinal direction along any angular segment θ through a range of 0°-360°. Embodiments of the method shown in FIGS. 3A and 3B may have particular application with the intravascular methods and apparatus of the present invention. For instance, a PEF catheter placed within the renal artery may propagate an electric field having a longitudinal portion that is aligned to run with the longitudinal dimension of the artery in the region of the renal nerves RN and the smooth muscle cell SMC of the vessel wall so that the wall of the artery remains at least substantially intact while the outer nerve cells are destroyed. C. Embodiments of Systems and Additional Methods for Neuromodulation FIG. 4 shows one embodiment of an intravascular pulsed electric field apparatus 200 in accordance with the present invention that includes one or more electrodes configured to physically contact a target region within the renal vasculature and deliver a pulsed electric field across a wall of the vasculature. The apparatus 200 is shown within a patient's renal artery RA, but it can be positioned in other intravascular locations (e.g., the renal vein). This embodiment of the apparatus 200 comprises an intravascular catheter 210 having a proximal section 211 a , a distal section 211 b , and a plurality of distal electrodes 212 at the distal section 211 b . The proximal section 211 a generally has an electrical connector to couple the catheter 210 to a pulse generator, and the distal section 211 b in this embodiment has a helical configuration. The apparatus 200 is electrically coupled to a pulsed electric field generator 100 located proximal and external to the patient; the electrodes 212 are electrically coupled to the generator via catheter 210 . The generator 100 may be utilized with any embodiment of the present invention described hereinafter for delivery of a PEF with desired field parameters. It should be understood that electrodes of embodiments described hereinafter may be connected to the generator, even if the generator is not explicitly shown or described with each variation. The helical distal section 211 b of catheter 210 is configured to appose the vessel wall and bring electrodes 212 into close proximity to extra-vascular neural structures. The pitch of the helix can be varied to provide a longer treatment zone, or to minimize circumferential overlap of adjacent treatments zones in order to reduce a risk of stenosis formation. This pitch change can be achieved by combining a plurality of catheters of different pitches to form catheter 210 , or by adjusting the pitch of catheter 210 through the use of internal pull wires, adjusting mandrels inserted into the catheter, shaping sheaths placed over the catheter, or by any other suitable means for changing the pitch either in-situ or before introduction into the body. The electrodes 212 along the length of the pitch can be individual electrodes, a common but segmented electrode, or a common and continuous electrode. A common and continuous electrode may, for example, comprise a conductive coil formed into or placed over the helical portion of catheter 210 . A common but segmented electrode may, for example, be formed by providing a slotted tube fitted onto or into the helical portion of the catheter, or by electrically connecting a series of individual electrodes. Individual electrodes or groups of electrodes 212 may be configured to provide a bipolar signal, or all or a subset of the electrodes may be used together in conjunction with a separate external patient ground for monopolar use (the ground pad may, for example, be placed on the patient's leg). Electrodes 212 may be dynamically assignable to facilitate monopolar and/or bipolar energy delivery between any of the electrodes and/or between any of the electrodes and an external ground. Catheter 210 may be delivered to renal artery RA in a low profile delivery configuration within sheath 150 . Once positioned within the artery, the catheter may self-expand or may be expanded actively, e.g., via a pull wire or a balloon, into contact with an interior wall of the artery. A pulsed electric field then may be generated by the PEF generator 100 , transferred through catheter 210 to electrodes 212 , and delivered via the electrodes 212 across the wall of the artery. In many applications, the electrodes are arranged so that the pulsed electric field is aligned with the longitudinal dimension of the artery to modulate the neural activity along the renal nerves (e.g., denervation). This may be achieved, for example, via irreversible electroporation, electrofusion and/or inducement of apoptosis in the nerve cells. FIG. 5 illustrates an apparatus 220 for neural modulation in accordance with another embodiment of the invention. The apparatus 220 includes a pair of catheters 222 a and 222 b having expandable distal sections 223 a and 223 b with helical electrodes 224 a and 224 b , respectively. The helical electrodes 224 a and 224 b are spaced apart from each other by a desired distance within a patient's renal vasculature. Electrodes 224 a - b may be actuated in a bipolar fashion such that one electrode is an active electrode and the other is a return electrode. The distance between the electrodes may be altered as desired to change the field strength and/or the length of nerve segment modulated by the electrodes. The expandable helical electrodes may comprise shape-memory properties that facilitate self-expansion, e.g., after passage through sheath 150 , or the electrodes may be actively expanded into contact with the vessel wall, e.g., via an inflatable balloon or via pull wires, etc. The catheters 222 a - b preferably are electrically insulated in areas other than the distal helices of electrodes 224 a - b. FIG. 6 illustrates an apparatus 230 comprising a balloon catheter 232 having expandable balloon 234 , a helical electrode 236 arranged about the balloon 234 , and a shaft electrode 238 on the shaft of catheter 232 . The shaft electrode 238 can be located proximal of expandable balloon 234 as shown, or the shaft electrode 238 can be located distal of the expandable balloon 234 . When the apparatus 230 is delivered to a target vessel, e.g., within renal artery RA, the expandable balloon 234 and the helical electrode 236 are arranged in a low profile delivery configuration. As seen in FIG. 6 , once the apparatus has been positioned as desired, expandable balloon 234 may be inflated to drive the helical electrode 236 into physical contact with the wall of the vessel. In this embodiment, the shaft electrode 238 does not physically contact the vessel wall. It is well known in the art of both traditional thermal RF energy delivery and of relatively non-thermal pulsed RF energy delivery that energy may be conducted to tissue to be treated from a short distance away from the tissue itself. Thus, it may be appreciated that “nerve contact” comprises both physical contact of a system element with a nerve, as well as electrical contact alone without physical contact, or a combination of the two. A centering element optionally may be provided to place electrodes in a central region of the vessel. The centering element may comprise, for example, an expandable balloon, such as balloon 234 of apparatus 230 , or an expandable basket as described hereinafter. One or more electrodes may be positioned on a central shaft of the centering element—either longitudinally aligned with the element or positioned on one or both sides of the element—as is shaft electrode 238 of apparatus 230 . When utilizing a balloon catheter such as catheter 232 , the inflated balloon may act as an insulator of increased impedance for directing a pulsed electric field along a desired electric flow path. As will be apparent, alternative insulators may be utilized. As seen in FIG. 6 , when the helical electrode 236 physically contacts the wall of renal artery RA, the generator 100 may generate a PEF such that current passes between the helical electrode 236 and the shaft electrode 238 in a bipolar fashion. The PEF travels between the electrodes along lines Li that generally extend along the longitudinal dimension of the artery. The balloon 234 locally insulates and/or increases the impedance within the patient's vessel such that the PEF travels through the wall of the vessel between the helical and shaft electrodes. This focuses the energy to enhance denervation and/or other neuromodulation of the patient's renal nerves, e.g., via irreversible electroporation. FIG. 7 illustrates an apparatus 240 similar to those shown in FIGS. 4-6 in accordance with another embodiment of the invention. The apparatus 240 comprises a balloon catheter 242 having an expandable balloon 244 and a shaft electrode 246 located proximal of the expandable balloon 244 . The apparatus 240 further comprises an expandable helical electrode 248 configured for delivery through a guidewire lumen 243 of the catheter 242 . The helical electrode 248 shown in FIG. 7 is self-expanding. As seen in FIG. 7 , after positioning the catheter 242 in a target vessel (e.g. renal artery RA), the balloon 244 is inflated until it contacts the wall of the vessel to hold the shaft electrode 246 at a desired location within the vessel and to insulate or increase the impedance of the interior of the vessel. The balloon 244 is generally configured to also center the shaft electrode 246 within the vessel or otherwise space the shaft electrode apart from the vessel wall by a desired distance. After inflating the balloon 244 , the helical electrode 248 is pushed through lumen 243 until the helical electrode 248 extends beyond the catheter shaft; the electrode 248 then expands or otherwise moves into the helical configuration to physically contact the vessel wall. A bipolar pulsed electric field may then be delivered between the helical electrode 248 and the shaft electrode 246 along lines Li. For example, the helical electrode 248 may comprise the active electrode and the shaft electrode 246 may comprise the return electrode, or vice versa. With reference now to FIG. 8 , apparatus comprising an expandable basket having a plurality of electrodes that may be expanded into contact with the vessel wall is described. Apparatus 250 comprises catheter 252 having expandable distal basket 254 formed from a plurality of circumferential struts or members. A plurality of electrodes 256 are formed along the members of basket 254 . Each member of the basket illustratively comprises a bipolar electrode pair configured to contact a wall of renal artery RA or another desired blood vessel. Basket 254 may be fabricated, for example, from a plurality of shape-memory wires or ribbons, such as Nitinol, spring steel or elgiloy wires or ribbons, that form basket members 253 . When the basket members comprise ribbons, the ribbons may be moved such that a surface area contacting the vessel wall is increased. Basket members 253 are coupled to catheter 252 at proximal and distal connections 255 a and 255 b , respectively. In such a configuration, the basket may be collapsed for delivery within sheath 150 , and may self-expand into contact with the wall of the artery upon removal from the sheath. Proximal and/or distal connection 255 a and 255 b optionally may be configured to translate along the shaft of catheter 252 for a specified or unspecified distance in order to facilitate expansion and collapse of the basket. Basket 254 alternatively may be formed from a slotted and/or laser-cut hypotube. In such a configuration, catheter 252 may, for example, comprise inner and outer shafts that are moveable relative to one another. Distal connection 255 b of basket 254 may be coupled to the inner shaft and proximal connection 255 a of the basket may be coupled to the outer shaft. Basket 254 may be expanded from a collapsed delivery configuration to the deployed configuration of FIG. 8 by approximating the inner and outer shafts of catheter 252 , thereby approximating the proximal and distal connections 255 a and 255 b of the basket and expanding the basket. Likewise, the basket may be collapsed by separating the inner and outer shafts of the catheter. As seen in FIG. 9 , individual electrodes may be arranged along a basket strut or member 253 . In one embodiment, the strut is formed from a conductive material coated with a dielectric material, and the electrodes 256 may be formed by removing regions of the dielectric coating. The insulation optionally may be removed only along a radially outer surface of the member such that electrodes 256 remain insulated on their radially interior surfaces; it is expected that this will direct the current flow outward into the vessel wall. In addition, or as an alternative, to the fabrication technique of FIG. 9 , the electrodes may be affixed to the inside surface, outside surface or embedded within the struts or members of basket 254 . The electrodes placed along each strut or member may comprise individual electrodes, a common but segmented electrode, or a common and continuous electrode. Individual electrodes or groups of electrodes may be configured to provide a bipolar signal, or all or a subset of the electrodes may be actuated together in conjunction with an external patient ground for monopolar use. One advantage of having electrodes 256 contact the vessel wall as shown in the embodiment of FIG. 8 is that it may reduce the need for an insulating element, such as an expandable balloon, to achieve renal denervation or other neuromodulation. However, it should be understood that such an insulating element may be provided and, for example, expanded within the basket. Furthermore, having the electrodes contact the wall may provide improved field geometry, i.e., may provide an electric field more aligned with the longitudinal axis of the vessel. Such contacting electrodes also may facilitate stimulation of the renal nerves before, during or after neuromodulation to better position the catheter 252 before treatment or for monitoring the effectiveness of treatment. In a variation of apparatus 250 , electrodes 256 may be disposed along the central shaft of catheter 252 , and basket 254 may simply center the electrodes within the vessel to facilitate more precise delivery of energy across the vessel wall. This configuration may be well suited to precise targeting of vascular or extra-vascular tissue, such as the renal nerves surrounding the renal artery. Correctly sizing the basket or other centering element to the artery provides a known distance between the centered electrodes and the arterial wall that may be utilized to direct and/or focus the electric field as desired. This configuration may be utilized in high-intensity focused ultrasound or microwave applications, but also may be adapted for use with any other energy modality as desired. Referring now to FIG. 10 , it is expected that electrodes forming a circumferential contact with the wall of the renal artery may provide for more complete renal denervation or renal neuromodulation. In FIG. 10 , a variation of the present invention comprising ring electrodes is described. Apparatus 260 comprises catheter 262 having expandable ring electrodes 264 a and 264 b configured to contact the wall of the vessel. The electrodes may be attached to the shaft of catheter 262 via struts 266 , and catheter 262 may be configured for delivery to renal artery RA through sheath 150 in a low profile configuration. Struts 266 may be self-expanding or may be actively or mechanically expanded. Catheter 262 comprises guidewire lumen 263 for advancement over a guidewire. Catheter 262 also comprises optional inflatable balloon 268 that may act as an insulating element of increased impedance for preferentially directing current flow that is traveling between electrodes 264 a and 264 b across the wall of the artery. FIGS. 11A-11C illustrate various embodiments of windings for ring electrodes 264 . As shown, the ring electrodes may, for example, be wound in a coil ( FIG. 11A ), a zigzag ( FIG. 11B ) or a serpentine configuration ( FIG. 11C ). The periodicity of the winding may be specified, as desired. Furthermore, the type of winding, the periodicity, etc., may vary along the circumference of the electrodes. With reference to FIG. 12 , a variation of apparatus 260 is described comprising ring electrodes 264 a ′ and 264 b ′ having a sinusoidal winding in one embodiment of the serpentine winding shown in FIG. 11C . Struts 266 illustratively are attached to apexes of the sinusoid. The winding of electrodes 264 a ′ and 264 b ′ may provide for greater contact area along the vessel wall than do electrodes 264 a and 264 b , while still facilitating sheathing of apparatus 260 within sheath 150 for delivery and retrieval. FIG. 13 illustrates another variation of apparatus 260 comprising a proximal ring electrode 264 a , and further comprising a distal electrode 270 delivered through guidewire lumen 263 of catheter 262 . The distal electrode 270 is non-expanding and is centered within the vessel via catheter 262 . The distal electrode 270 may be a standard guide wire which is connected to the pulsed electric field generator and used as an electrode. However, it should be understood that electrode 270 alternatively may be configured for expansion into contact with the vessel wall, e.g., may comprise a ring or helical electrode. Delivering the distal electrode through the lumen of catheter 262 may reduce a delivery profile of apparatus 260 and/or may improve flexibility of the device. Furthermore, delivery of the distal electrode through the guidewire lumen may serve as a safety feature that ensures that the medical practitioner removes any guidewire disposed within lumen 263 prior to delivery of a PEF. It also allows for customization of treatment length, as well as for treatment in side branches, as described hereinafter. Ring electrodes 264 a and 264 b and 264 a ′ and 264 b ′ optionally may be electrically insulated along their radially inner surfaces, while their radially outer surfaces that contact the vessel wall are exposed. This may reduce a risk of thrombus formation and also may improve or enhance the directionality of the electric field along the longitudinal axis of the vessel. This also may facilitate a reduction of field voltage necessary to disrupt neural fibers. Materials utilized to at least partially insulate the ring electrodes may comprise, for example, PTFE, ePTFE, FEP, chronoprene, silicone, urethane, Pebax, etc. With reference to FIG. 14 , another variation of apparatus 260 is described, wherein the ring electrodes have been replaced with point electrodes 272 disposed at the ends of struts 266 . The point electrodes may be collapsed with struts 266 for delivery through sheath 150 and may self-expand with the struts into contact with the vessel wall. In FIG. 14 , catheter 262 illustratively comprises four point electrodes 272 on either side of balloon 268 . However, it should be understood that any desired number of struts and point electrodes may be provided around the circumference of catheter 262 . In FIG. 14 , apparatus 260 illustratively comprises four struts 266 and four point electrodes 272 on either side of balloon 268 . By utilizing all of the distally disposed electrodes 272 b as active electrodes and all proximal electrodes 272 a as return electrodes, or vice versa, lines Li along which the electric field propagates may be aligned with the longitudinal axis of a vessel. A degree of line Li overlap along the rotational axis of the vessel may be specified by specifying the angular placement and density of point electrodes 272 about the circumference of the catheter, as well as by specifying parameters of the PEF. With reference now to FIG. 15 , another variation of an intravascular PEF catheter is described. Apparatus 280 comprises catheter 282 having optional inflatable balloon or centering element 284 , shaft electrodes 286 a and 286 b disposed along the shaft of the catheter on either side of the balloon, as well as optional radiopaque markers 288 disposed along the shaft of the catheter, illustratively in line with the balloon. Balloon 284 serves as both a centering element for electrodes 286 and as an electrical insulator for directing the electric field, as described previously. Apparatus 280 may be particularly well-suited for achieving precise targeting of desired arterial or extra-arterial tissue, since properly sizing balloon 284 to the target artery sets a known distance between centered electrodes 286 and the arterial wall that may be utilized when specifying parameters of the PEF. Electrodes 286 alternatively may be attached to balloon 284 rather than to the central shaft of catheter 282 such that they contact the wall of the artery. In such a variation, the electrodes may be affixed to the inside surface, outside surface or embedded within the wall of the balloon. Electrodes 286 arranged along the length of catheter 282 can be individual electrodes, a common but segmented electrode, or a common and continuous electrode. Furthermore, electrodes 286 may be configured to provide a bipolar signal, or electrodes 286 may be used together or individually in conjunction with a separate patient ground for monopolar use. Referring now to FIGS. 16A and 16B , a method of using apparatus 280 to achieve renal denervation is described. As seen in FIG. 16A , catheter 282 may be disposed at a desired location within renal artery RA, balloon or centering element 284 may be expanded to center electrodes 286 a and 286 b and to optionally provide electrical insulation, and a PEF may be delivered, e.g., in a bipolar fashion between the proximal and distal electrodes 286 a and 286 b . It is expected that the PEF will achieve renal denervation and/or neuromodulation along treatment zone one T 1 . If it is desired to modulate neural activity in other parts of the renal artery, balloon 284 may be at least partially deflated, and the catheter may be positioned at a second desired treatment zone T 2 , as in FIG. 16B . The medical practitioner optionally may utilize fluoroscopic imaging of radiopaque markers 288 to orient catheter 282 at desired locations for treatment. For example, the medical practitioner may use the markers to ensure a region of overlap O between treatment zones T 1 and T 2 , as shown. With reference to FIG. 17 , a variation of apparatus 280 is described comprising a plurality of dynamically controllable electrodes 286 a and 286 b disposed on the proximal side of balloon 284 . In one variation, any one of proximal electrodes 286 a may be energized in a bipolar fashion with distal electrode 286 b to provide dynamic control of the longitudinal distance between the active and return electrodes. This alters the size and shape of the zone of treatment. In another variation, any subset of proximal electrodes 286 a may be energized together as the active or return electrodes of a bipolar electric field established between the proximal electrodes and distal electrode 286 b. Although the apparatus 280 shown in FIG. 17 has three proximal electrodes 286 a 1 , 286 a 2 and 286 a 3 , it should be understood that the apparatus 280 can have any alternative number of proximal electrodes. Furthermore, the apparatus 280 can have a plurality of distal electrodes 286 b in addition, or as an alternative, to multiple proximal electrodes. Additionally, one electrode of a pair may be coupled to the catheter 282 , and the other electrode may be delivered through a lumen of the catheter, e.g., through a guidewire lumen. The catheter and endoluminally-delivered electrode may be repositioned relative to one another to alter a separation distance between the electrodes. Such a variation also may facilitate treatment of a variety of renal vasculature anatomies. In the variations of apparatus 280 described thus far, distal electrode 286 b is coupled to the shaft of catheter 282 distal of balloon 284 . The distal electrode may utilize a lumen within catheter 282 , e.g., for routing of a lead wire that acts as ground. Additionally, the portion of catheter 282 distal of balloon 284 is long enough to accommodate the distal electrode. Catheters commonly are delivered over metallic and/or conductive guidewires. In many interventional therapies involving catheters, guidewires are not removed during treatment. As apparatus 280 is configured for delivery of a pulsed electric field, if the guidewire is not removed, there may be a risk of electric shock to anyone in contact with the guidewire during energy delivery. This risk may be reduced by using polymer-coated guidewires. With reference to FIG. 18 , another variation of apparatus 280 is described wherein distal electrode 286 b of FIGS. 16 and 17 has been replaced with a distal electrode 270 configured to be moved through a lumen of the catheter as described previously with respect to FIG. 13 . As will be apparent, proximal electrode 286 a alternatively may be replaced with the luminally-delivered electrode, such that electrodes 286 b and 270 form a bipolar electrode pair. Electrode 270 does not utilize an additional lumen within catheter 282 , which may reduce profile. Additionally, the length of the catheter distal of the balloon need not account for the length of the distal electrode, which may enhance flexibility. Furthermore, the guidewire must be exchanged for electrode 270 prior to treatment, which reduces a risk of inadvertent electrical shock. In one variation, electrode 270 optionally may be used as the guidewire over which catheter 282 is advanced into position prior to delivery of the PEF, thereby obviating a need for exchange of the guidewire for the electrode. Alternatively, a standard metallic guidewire may be used as the electrode 270 simply by connecting the standard guidewire to the pulsed electric field generator. The distal electrode 270 may be extended any desired distance beyond the distal end of catheter 282 . This may provide for dynamic alteration of the length of a treatment zone. Furthermore, this might facilitate treatment within distal vasculature of reduced diameter. With reference to FIGS. 19A and 19B , it might be desirable to perform treatments within one or more vascular branches that extend from a main vessel, for example, to perform treatments within the branches of the renal artery in the vicinity of the renal hilum. Furthermore, it might be desirable to perform treatments within abnormal or less common branchings of the renal vasculature, which are observed in a minority of patients. As seen in FIG. 19A , distal electrode 270 may be placed in such a branch of renal artery RA, while catheter 282 is positioned within the main branch of the artery. As seen in FIG. 19B , multiple distal electrodes 270 might be provided and placed in various common or uncommon branches of the renal artery, while the catheter remains in the main arterial branch. Referring to FIG. 20 , yet another variation of an intravascular PEF catheter is described. Apparatus 290 comprises catheter 292 having a plurality of shaft electrodes 294 disposed in line with centering element 296 . Centering element 296 illustratively comprises an expandable basket, such as previously described expandable basket 254 of FIG. 8 . However, it should be understood that the centering element alternatively may comprise a balloon or any other centering element. Electrodes 294 may be utilized in a bipolar or a monopolar fashion. Referring now to FIG. 21 , another variation of the invention is described comprising electrodes configured for dynamic radial repositioning of one or more of the electrodes relative to a vessel wall, thereby facilitating focusing of a pulsed electric field delivered by the electrodes. Apparatus 300 comprises catheter 302 having electrodes 304 disposed in line with nested expandable elements. The nested expandable elements comprise an inner expandable element 306 and an outer expandable centering element 308 . Electrodes 304 are disposed along the inner expandable element, while the outer expandable centering element is configured to center and stabilize catheter 302 within the vessel. Inner element 306 may be expanded to varying degrees, as desired by a medical practitioner, to dynamically alter the radial positions of electrodes 304 . This dynamic radial repositioning may be utilized to focus energy delivered by electrodes 304 such that it is delivered to target tissue. Nested elements 306 and 308 may comprise a balloon-in-balloon arrangement, a basket-in-basket arrangement, some combination of a balloon and a basket, or any other expandable nested structure. In FIG. 21 , inner expandable element 306 illustratively comprises an expandable basket, while outer expandable centering element 308 illustratively comprises an expandable balloon. Electrodes 302 are positioned along the surface of inner balloon 306 . Any of the variations of the present invention described herein optionally may be configured for infusion of agents into the treatment area before, during or after energy application, for example, to enhance or modify the neurodestructive or neuromodulatory effect of the energy, to protect or temporarily displace non-target cells, and/or to facilitate visualization. Additional applications for infused agents will be apparent. If desired, uptake of infused agents by cells may be enhanced via initiation of reversible electroporation in the cells in the presence of the infused agents. Infusion may be especially desirable when a balloon centering element is utilized. The infusate may comprise, for example, saline or heparinized saline, protective agents, such as Poloxamer-188, or anti-proliferative agents. Variations of the present invention additionally or alternatively may be configured for aspiration. For example, infusion ports or outlets may be provided on a catheter shaft adjacent a centering device, the centering device may be porous (for instance, a “weeping” balloon), or basket struts may be made of hollow hypotubes and slotted or perforated to allow infusion or aspiration. With reference to FIG. 22 , a variation of the present invention comprising an infusion/aspiration PEF catheter is described. Apparatus 310 comprises catheter 312 having proximal and distal inflatable balloons 314 a and 314 b , respectively. Proximal shaft electrode 316 a is disposed between the balloons along the shaft of catheter 312 , while distal electrode 316 b is disposed distal of the balloons along the catheter shaft. One or more infusion or aspiration holes 318 are disposed along the shaft of catheter 312 between the balloons in proximity to proximal electrode 316 a. Apparatus 310 may be used in a variety of ways. In a first method of use, catheter 312 is disposed within the target vessel, such as renal artery RA, at a desired location. One or both balloons 314 are inflated, and a protective agent or other infusate is infused through hole(s) 318 between the balloons in proximity to electrode 316 a . A PEF suitable for initiation of reversible electroporation is delivered across electrodes 316 to facilitate uptake of the infusate by non-target cells within the vessel wall. Delivery of the protective agent may be enhanced by first inflating distal balloon 314 b , then infusing the protective agent, which displaces blood, then inflating proximal balloon 314 a. Remaining infusate optionally may be aspirated such that it is unavailable during subsequent PEF application when irreversible electroporation of nerve cells is initiated. Aspiration may be achieved by at least partially deflating one balloon during aspiration. Alternatively, aspiration may be achieved with both balloons inflated, for example, by infusing saline in conjunction with the aspiration to flush out the vessel segment between the inflated balloons. Such blood flushing may reduce a risk of clot formation along proximal electrode 316 a during PEF application. Furthermore, flushing during energy application may cool the electrode and/or cells of the wall of the artery. Such cooling of the wall cells might protect the cells from irreversible electroporative damage, possibly reducing a need for infusion of a protective agent. After infusion and optional aspiration, a PEF suitable for initiation of irreversible electroporation in target nerve cells may be delivered across electrodes 316 to denervate or to modulate neural activity. In an alternative method, infusion of a protective agent may be performed during or after initiation of irreversible electroporation in order to protect non-target cells. The protective agent may, for example, plug or fill pores formed in the non-target cells via the irreversible electroporation. In another alternative method, a solution of chilled (i.e., less than body temperature) heparinized saline may be simultaneously infused and aspirated between the inflated balloons to flush the region between the balloons and decrease the sensitivity of vessel wall cells to electroporation. This is expected to further protect the cells during application of the PEF suitable for initiation of irreversible electroporation. Such flushing optionally may be continuous throughout application of the pulsed electric field. A thermocouple or other temperature sensor optionally may be positioned between the balloons such that a rate of chilled infusate infusion may be adjusted to maintain a desired temperature. The chilled infusate preferably does not cool the target tissue, e.g., the renal nerves. A protective agent, such as Poloxamer-188, optionally may be infused post-treatment as an added safety measure. Infusion alternatively may be achieved via a weeping balloon catheter. Further still, a cryoballoon catheter having at least one electrode may be utilized. The cryoballoon may be inflated within a vessel segment to locally reduce the temperature of the vessel segment, for example, to protect the segment and/or to induce thermal apoptosis of the vessel wall during delivery of an electric field. The electric field may, for example, comprise a PEF or a thermal, non-pulsed electric field, such as a thermal RF field. Referring now to FIGS. 23A , 23 B and 23 C, a variation of a PEF catheter configured for passage of electrode(s) at least partially across the vessel wall is described. For example, the electrode(s) may be positioned within the renal vein and then passed across the wall of the renal vein such that they are disposed in Gerota's or renal fascia and near or at least partially around the renal artery. In this manner, the electrode(s) may be positioned in close proximity to target renal nerve fibers prior to delivery of a pulsed electric field. As seen in FIG. 23A , apparatus 320 comprises catheter 322 having needle ports 324 and centering element 326 , illustratively an inflatable balloon. Catheter 322 also optionally may comprise radiopaque markers 328 . Needle ports 324 are configured for passage of needles 330 therethrough, while needles 330 are configured for passage of electrodes 340 . Renal vein RV runs parallel to renal artery RA. An imaging modality, such as intravascular ultrasound, may be used to identify the position of the renal artery relative to the renal vein. For example, intravascular ultrasound elements optionally may be integrated into catheter 322 . Catheter 322 may be positioned within renal vein RV using well-known percutaneous techniques, and centering element 326 may be expanded to stabilize the catheter within the vein. Needles 330 then may be passed through catheter 322 and out through needle ports 324 in a manner whereby the needles penetrate the wall of the renal vein and enter into Gerota's or renal fascia F. Radiopaque markers 328 may be visualized with fluoroscopy to properly orient needle ports 324 prior to deployment of needles 330 . Electrodes 340 are deployed through needles 330 to at least partially encircle renal artery RA, as in FIGS. 23A and 23B . Continued advancement of the electrodes may further encircle the artery, as in FIG. 23C . With the electrodes deployed, stimulation and/or PEF electroporation waveforms may be applied to denervate or modulate the renal nerves. Needles 330 optionally may be partially or completely retracted prior to treatment such that electrodes 340 encircle a greater portion of the renal artery. Additionally, a single electrode 340 may be provided and/or actuated in order to provide a monopolar PEF. Infusate optionally may be infused from needles 330 into fascia F to facilitate placement of electrodes 340 by creating a space for placement of the electrodes. The infusate may comprise, for example, fluids, heated or chilled fluids, air, CO 2 , saline, contrast agents, gels, conductive fluids or any other space-occupying material—be it gas, solid or liquid. Heparinized saline also may be injected. Saline or hypertonic saline may enhance conductivity between electrodes 340 . Additionally or alternatively, drugs and/or drug delivery elements may be infused or placed into the fascia through the needles. After treatment, electrodes 340 may be retracted within needles 330 , and needles 330 may be retracted within catheter 322 via needle ports 324 . Needles 330 preferably are small enough that minimal bleeding occurs and hemostasis is achieved fairly quickly. Balloon centering element 326 optionally may remain inflated for some time after retrieval of needles 330 in order to block blood flow and facilitate the clotting process. Alternatively, a balloon catheter may be advanced into the renal vein and inflated after removal of apparatus 320 . Referring to FIGS. 24A and 24B , variations of the invention comprising detectors or other elements for measuring or monitoring treatment efficacy are described. Variations of the invention may be configured to deliver stimulation electric fields, in addition to denervating or modulating PEFs. These stimulation fields may be utilized to properly position the apparatus for treatment and/or to monitor the effectiveness of treatment in modulating neural activity. This may be achieved by monitoring the responses of physiologic parameters known to be affected by stimulation of the renal nerves. Such parameters comprise, for example, renin levels, sodium levels, renal blood flow and blood pressure. Stimulation also may be used to challenge the denervation for monitoring of treatment efficacy: upon denervation of the renal nerves, the known physiologic responses to stimulation should no longer occur in response to such stimulation. Efferent nerve stimulation waveforms may, for example, comprise frequencies of about 1-10 Hz, while afferent nerve stimulation waveforms may, for example, comprise frequencies of up to about 50 Hz. Waveform amplitudes may, for example, range up to about 50V, while pulse durations may, for example, range up to about 20 milliseconds. When the nerve stimulation waveforms are delivered intravascularly, as in several embodiments of the present invention, field parameters such as frequency, amplitude and pulse duration may be modulated to facilitate passage of the waveforms through the wall of the vessel for delivery to target nerves. Furthermore, although exemplary parameters for stimulation waveforms have been described, it should be understood that any alternative parameters may be utilized as desired. The electrodes used to deliver PEFs in any of the previously described variations of the present invention also may be used to deliver stimulation waveforms to the renal vasculature. Alternatively, the variations may comprise independent electrodes configured for stimulation. As another alternative, a separate stimulation apparatus may be provided. One way to use stimulation to identify renal nerves is to stimulate the nerves such that renal blood flow is affected—or would be affected if the renal nerves had not been denervated or modulated. Stimulation acts to reduce renal blood flow, and this response may be attenuated or abolished with denervation. Thus, stimulation prior to neural modulation would be expected to reduce blood flow, while stimulation after neural modulation would not be expected to reduce blood flow to the same degree when utilizing similar stimulation parameters and location(s) as prior to neural modulation. This phenomenon may be utilized to quantify an extent of renal neuromodulation. Variations of the present invention may comprise elements for monitoring renal blood flow or for monitoring any of the other physiological parameters known to be affected by renal stimulation. In FIG. 24A , a variation of apparatus 280 of FIG. 16 is described having an element for monitoring of renal blood flow. Guidewire 350 having Doppler ultrasound sensor 352 has been advanced through the lumen of catheter 282 for monitoring blood flow within renal artery RA. Doppler ultrasound sensor 352 is configured to measure the velocity of flow through the artery. A flow rate then may be calculated according to the formula: Q=VA  (1) where Q equals flow rate, V equals flow velocity and A equals cross-sectional area. A baseline of renal blood flow may be determined via measurements from sensor 352 prior to delivery of a stimulation waveform, then stimulation may be delivered between electrodes 286 a and 286 b , preferably with balloon 284 deflated. Alteration of renal blood flow from the baseline, or lack thereof, may be monitored with sensor 352 to identify optimal locations for neuromodulation and/or denervation of the renal nerves. FIG. 24B illustrates a variation of the apparatus of FIG. 24A , wherein Doppler ultrasound sensor 352 is coupled to the shaft of catheter 282 . Sensor 352 illustratively is disposed proximal of balloon 284 , but it should be understood that the sensor alternatively may be disposed distal of the balloon. In addition or as an alternative to intravascular monitoring of renal blood flow via Doppler ultrasound, such monitoring optionally may be performed from external to the patient whereby renal blood flow is visualized through the skin (e.g., using an ultrasound transducer). In another variation, one or more intravascular pressure transducers may be used to sense local changes in pressure that may be indicative of renal blood flow. As yet another alternative, blood velocity may be determined, for example, via thermodilution by measuring the time lag for an intravascular temperature input to travel between points of known separation distance. For example, a thermocouple may be incorporated into, or provided in proximity to, each electrode 286 a and 286 b , and chilled (i.e., lower than body temperature) fluid or saline may be infused proximally of the thermocouple(s). A time lag for the temperature decrease to register between the thermocouple(s) may be used to quantify flow characteristic(s). A baseline estimate of the flow characteristic(s) of interest may be determined prior to stimulation of the renal nerves and may be compared with a second estimate of the characteristic(s) determined after stimulation. Commercially available devices optionally may be utilized to monitor treatment. Such devices include, for example, the SmartWire™, FloWire™ and WaveWire™ devices available from Volcano™ Therapeutics Inc., of Rancho Cordova, Calif., as well as the PressureWire® device available from RADI Medical Systems AB of Uppsala, Sweden. Additional commercially available devices will be apparent. An extent of electroporation additionally or alternatively may be monitored directly using Electrical Impedance Tomography (“EIT”) or other electrical impedance measurements, such as an electrical impedance index. Although preferred illustrative variations of the present invention are described above, it will be apparent to those skilled in the art that various changes and modifications may be made thereto without departing from the invention. For example, although the variations primarily have been described for use in combination with pulsed electric fields, it should be understood that any other electric field may be delivered as desired. It is intended in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the invention.

Methods and apparatus are provided for renal neuromodulation using a pulsed electric field to effectuate electroporation or electrofusion. It is expected that renal neuromodulation (e.g., denervation) may, among other things, reduce expansion of an acute myocardial infarction, reduce or prevent the onset of morphological changes that are affiliated with congestive heart failure, and/or be efficacious in the treatment of end stage renal disease. Embodiments of the present invention are configured for percutaneous intravascular delivery of pulsed electric fields to achieve such neuromodulation.

[0001] Under 35 U.S.C. § 119(e), this application claims the benefit of prior U.S. Provisional Application No. 60/472,034, filed May 19, 2003, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] The present disclosure relates to new solid-state forms of 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazole sodium aqua complexes, and to processes for their preparation. The disclosure is also directed to pharmaceutical compositions containing these solid-state forms, and to methods of treatment using the solid-state forms. BACKGROUND OF THE INVENTION [0003] Pantoprazole is an irreversible proton pump inhibitor which has the chemical structure: [0004] Pantoprazole is used, as an active pharmaceutical ingredient, in the treatment of gastric ulcers, usually in the form of its sodium salt. This was described in European Patent Application No. EP-A-0166287. [0005] It is known that pantoprazole sodium salt can exist as a monohydrate (European Patent No. 0533790) or as a sesquihydrate (European Patent No. 0589981). SUMMARY OF THE INVENTION [0006] The present disclosure is directed, in part, to new solid-state forms of 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazole sodium aqua complexes. [0007] In one embodiment, the solid-state form is an organic solvent free hexacoordinated octahedral sodium aqua complex of pantoprazole, solid-state Form N. [0008] In another embodiment, the solid-state form is an acetone solvate hexacoordinated octahedral sodium aqua complex of pantoprazole, solid-state Form A 1 . [0009] In another embodiment, the solid-state form is an acetone solvate pentacoordinated square pyramidal sodium aqua complex of pantoprazole, solid-state Form A 2 . [0010] In another embodiment, the solid-state form is an acetone solvate sodium aqua complex of pantoprazole, solid-state Form A 3 . [0011] In another embodiment, the solid-state form is an acetone solvate sodium aqua complex of pantoprazole, solid-state Form A 4 . [0012] In another embodiment, the solid-state form is a methyl acetate hexacoordinated octahedral sodium aqua complex of pantoprazole, solid-state Form B 1 . [0013] In another embodiment, the solid-state form is a methyl acetate sodium aqua complex of pantoprazole, solid-state Form B 2 . [0014] In another embodiment, the solid-state form is a methyl acetate sodium aqua complex of pantoprazole, solid-state Form B 3 . [0015] In another embodiment, the solid-state form is a methyl ethyl ketone solvate hexacoordinated octahedral sodium aqua complex of pantoprazole, solid-state Form C 1 . [0016] In another embodiment, the solid-state form is a methyl ethyl ketone solvate sodium aqua complex of pantoprazole, solid-state Form C 2 . [0017] In another embodiment, the solid-state form is a diethyl ketone solvate hexacoordinated octahedral sodium aqua complex of pantoprazole, solid-state Form D 1 . [0018] In another embodiment, the solid-state form is a desolvated sodium aqua complex of pantoprazole, solid-state Form E 1 . [0019] The present disclosure is also directed to processes for preparing the new solid-state Forms N, A 1 , A 2 , A 3 , A 4 , B 1 , B 2 , B 3 , C 1 , C 2 , D 1 , and E 1 . [0020] A further embodiment is the use of the solid-state octahedral sodium aqua complexes of pantoprazole of the present invention as raw materials for the preparation of (i) the monohydrate and sesquihydrate forms of pantoprazole sodium, (ii) the pantoprazole hexacoordinated octahedral sodium aqua complexes and pantoprazole pentacoordinated square pyramidal aqua complexes of the present invention, and (iii) other pharmaceutically acceptable pantoprazole salts, such as, but not limited to, the magnesium salt of pantoprazole. [0021] Yet another embodiment of this disclosure is directed to pharmaceutical compositions containing one or more of the solid-state forms of sodium aqua complexes of pantoprazole of the present invention. [0022] Further embodiments provide methods for inhibiting gastric acid secretion, protecting the stomach and intestines, and treating gastric ulcers by administering to a patient in need of such treatment a therapeutically effective amount of one or more of the solid-state forms of sodium aqua complexes of pantoprazole of the present invention, or a composition containing a therapeutically effective amount of one or more of these solid-state forms. BRIEF DESCRIPTION OF THE DRAWINGS [0023] FIG. 1 is a crystal packing diagram of the new solid-state solvent free pantoprazole hexacoordinated octahedral sodium aqua complex, Form N. [0024] FIG. 2 is a crystal packing diagram of the new solid-state acetone solvate form of pantoprazole hexacoordinated octahedral sodium aqua complex, Form A 1 . [0025] FIG. 3 is a crystal packing diagram of the new solid-state acetone solvate form of pantoprazole pentacoordinated square pyramidal sodium aqua complex, Form A 2 . [0026] FIG. 4 is a crystal packing diagram of the new solid-state methyl acetate solvate form of pantoprazole hexacoordinated octahedral sodium aqua complex, Form B 1 . [0027] FIG. 5 is a crystal packing diagram of the new solid-state methyl ethyl ketone solvate form of pantoprazole hexacoordinated octahedral sodium aqua complex, Form C 1 . [0028] FIG. 6 is a crystal packing diagram of the new solid-state diethyl ketone solvate form of pantoprazole hexacoordinated octahedral sodium aqua complex, Form D 1 . DETAILED DESCRIPTION OF THE INVENTION [0029] One object of this disclosure is to provide new solid-state forms of pantoprazole sodium aqua complexes. [heading-0030] Solid-State Form N [0031] The new solid-state Form N organic solvent free hexacoordinated octahedral sodium aqua complex of pantoprazole, prepared according to the process of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0032] Single crystals of the new solid-state Form N were prepared according to the process set forth herein, and single crystal x-ray diffraction data collected using a Bruker Nonius FR591/KappaCCD diffractometer using CuKα radiation. Basic crystallographic data for the new solid-state Form N are represented in Table 1. TABLE 1 Basic crystallographic data for the new solid-state Form N organic solvent free hexacoordinated octahedral sodium aqua complex of pantoprazole. Form N Empirical formula [Na 2 (C 16 H 14 F 2 N 3 O 4 S) 2 (OH 2 ) 3 ] Formula weight 863.74 Temperature 100(2) K Crystal size 0.05 × 0.15 × 0.70 mm Crystal system, space Orthorhombic, P bca group Unit cell dimensions a = 17.10(2) Å b = 13.49(1) Å c = 33.15(2) Å α = β = γ = 90° Volume 7647.5(1) Å 3 Z 8 Calculated density 1.50 gcm −3 [0033] The new solid-state Form N has a characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of the organic solvent free Form N. [0034] The new solid-state Form N has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees, as follows: 5.3±0.2°, 13.1±0.2°, 16.9±0.2°, 20.5±0.2°, 21.6±0.2° and 25.1±0.2°. X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0035] The new solid-state Form N can be obtained by crystallization from solutions of pantoprazole sodium salt in organic solvents and water. A process for the preparation of the new solid-state Form N organic solvent free hexacoordinated octahedral sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in an organic solvent or mixture of organic solvents; (ii) dissolving the pantoprazole sodium salt in the organic solvent or mixture of organic solvents; (iii) optionally filtering the solution of pantoprazole sodium salt and organic solvent or mixture of organic solvents; (iv) adding water; (v) crystallizing the new solid-state Form N solvent free hexacoordinated octahedral sodium aqua complex of pantoprazole; (vi) isolating the crystals thus obtained; and (vii) drying the crystals. [0043] Organic solvents suitable in the process include, but are not limited to, aliphatic esters, such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, sec-butyl acetate and tert-butyl acetate, and mixtures thereof. [0044] For example, for the preparation of the new solid-state Form N, the organic solvent used may be an aliphatic ester chosen from, but not limited to, ethyl acetate and butyl acetate, or mixtures thereof. [0045] In one embodiment of step (ii) of the process for the preparation of the new solid-state Form N, the suspension of pantoprazole sodium salt and organic solvent is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain clear solution. [0046] In one embodiment of step (iv) of the process for the preparation of the new solid-state Form N, water can be added in an amount of about 0.1% to about 5% by volume of the organic solvent or solvents, for example, in an amount of about 2.5% by volume of the organic solvent or solvents. [0047] In one embodiment of the step (v) of process for the preparation of the new solid-state Form N, the solution is cooled to from about 70° C. to about −10° C., for example, cooled to about room temperature. [0048] In another embodiment of the step (v) process for the preparation of the new solid-state Form N, the crystallization is induced over a time period of from about 15 minutes to about 24 hours. This may be performed with or without stirring the mixture. [0049] In one embodiment of step (vii) of the process for the preparation of the new solid-state Form N, the isolated crystals are dried at a pressure of from about atmospheric pressure to about 5 mbar and at a temperature of from about room temperature to about 100° C. for a time period of from about 1 hour to about 24 hours. [0050] It has been found that by use of the process of the present invention no transformation of the new solid-state Form N takes place and that the Form N product has solid-state purity of greater than about 95.0%, greater than about 99.0%, greater than about 99.9%, or is solid-state pure. [0051] It has also been found that by the use of the process of the present invention no decomposition of the new solid-state Form N takes place and that the Form N product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0052] It has also been found that the new solid-state Form N is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0053] The new solid-state Form N solvent free pantoprazole hexacoordinated octahedral sodium aqua complex of the present invention can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium, i.e., it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium. [0054] The new solid-state Form N can be also converted, by the use of the processes of the present invention, to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes, described herein [0055] The new solid-state Form N, prepared according to the process of the present invention, can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for preparation of the magnesium salt of pantoprazole. [heading-0056] Solid-State Form A 1 [0057] Another object of the present disclosure is to provide a new solid-state acetone solvate form of a hexacoordinated octahedral sodium aqua complex of pantoprazole, solid-state Form A 1 . [0058] The new solid-state acetone solvate Form A 1 , prepared according to the process of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0059] Single crystals of the new solid-state acetone solvate Form A 1 were prepared according to the process set forth herein, and single crystal x-ray diffraction data collected using a Bruker Nonius FR591/KappaCCD diffractometer using CuKα radiation. Basic crystallographic data for the new solid-state Form A 1 are represented in Table 2. TABLE 2 Basic crystallographic data for the new solid-state acetone solvent Form A1 hexacoordinated octahedral sodium aqua complex of pantoprazole. Form A1 Empirical formula [Na 2 (C 16 H 14 F 2 N 3 O 4 S) 2 (OH 2 ) 4 ]. (C 3 H 6 O) 2 Formula weight 998.92 Temperature 100 (2) K Crystal size 0.01 × 0.20 × 0.50 mm Crystal system, space Monoclinic, P 2 1 group Unit cell dimensions a = 13.58(2) Å b = 10.63(1) Å c = 15.72(2) Å β = 90.5(3)° α = γ = 90° Volume 2269.9(2) Å 3 Z 2 Calculated density 1.46 gcm −3 [0060] The new solid-state acetone solvate Form A 1 has a characteristic x-ray powder pattern, obtained by x-ray diffraction on a powder sample of Form A 1 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0061] The new solid-state acetone solvate Form A 1 hexacoordinated octahedral sodium aqua complex of pantoprazole has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.6±0.2°, 11.9±0.2°, 12.9±0.2°, 13.8±0.2°, 15.4±0.2°, 16.4±0.2° and 26.1±0.2°. [0062] The new solid-state acetone solvate Form A 1 can be obtained by crystallization from a solution of pantoprazole sodium salt and acetone. A process for preparation of the new solid-state acetone solvate Form A 1 hexacoordinated octahedral sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in acetone; (ii) dissolving the pantoprazole sodium salt in acetone; (iii) optionally filtering the solution of pantoprazole sodium salt and acetone; (iv) crystallizing the new solid-state acetone solvate Form A 1 hexacoordinated octahedral sodium aqua complex of pantoprazole; (v) isolating the crystals thus obtained; and (vi) drying the crystals. [0069] In one embodiment of step (ii) of the process for the preparation of the new solid-state acetone solvate Form A 1 , the suspension of pantoprazole sodium salt and acetone is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain clear solution. [0070] In one embodiment of step (iv) of the process for the preparation of the new solid-state acetone solvate Form A 1 , the solution is cooled to from about 70° C. to about −10° C., for example, cooled to about room temperature. [0071] In another embodiment of step (iv) of the process for the preparation of the new solid-state acetone solvate Form A 1 , crystallization is induced over a time period of from about 15 minutes to about 24 hours. In one embodiment, this is performed without stirring the mixture. [0072] In one embodiment of step (vi) of the process for the preparation of the new solid-state acetone solvate Form A 1 , the isolated crystals are dried at about atmospheric pressure and at about room temperature for a time period of from about 1 hour to about 24 hours, for example, for a time period of about 12 hours. [0073] It has been found that by the use of the process of the present invention, no decomposition of the new solid-state acetone solvate Form A 1 , takes place and that the Form A 1 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0074] It has also been found that the new solid-state Form A 1 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0075] The new solid-state acetone solvate Form A 1 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0076] The new solid-state acetone solvate Form A 1 can be also converted by the use of the processes of the present invention to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes described herein. [0077] The new solid-state acetone solvate Form A 1 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of magnesium salt of pantoprazole. [heading-0078] Solid-State Form A 2 [0079] Another object of this disclosure is to provide a new solid-state acetone solvate pentacoordinated square pyramidal sodium aqua complex of pantoprazole, solid-state Form A 2 . [0080] The new solid-state acetone solvate Form A 2 , prepared according to the process of the present invention has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0081] Single crystals of the new solid-state acetone solvate Form A 2 were prepared according to the process of the present invention, and single crystal x-ray diffraction data collected using a Bruker Nonius FR591/KappaCCD diffractometer using CuKα radiation. Basic crystallographic data for the new solid-state acetone solvate Form A 2 hexacoordinated octahedral sodium aqua complex of pantoprazole are represented in Table 3. TABLE 3 Basic crystallographic data for the new solid-state acetone solvate Form A2 pentacoordinated square pyramidal sodium aqua complex of pantoprazole. Form A2 Empirical formula [Na 2 (C 16 H 14 F 2 N 3 O 4 S)(OH 2 )].(C 3 H 6 O) Formula weight 481.45 Temperature 100 (2) K Crystal size 0.10 × 0.40 × 0.60 mm Crystal system, space Monoclinic, P 2 1 /a group Unit cell dimensions a = 13.18(1) Å b = 10.27(1) Å c = 17.28(2) Å β = 109.1(1)° α = γ = 90° Volume 2209.4(1) Å 3 Z 4 Calculated density 1.45 gcm −3 [0082] The new solid-state acetone solvate Form A 2 has a characteristic x-ray powder pattern, obtained by x-ray diffraction on a powder sample of Form A 2 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0083] The new solid-state acetone solvate Form A 2 has characteristic x-ray powder diffraction peaks, designated by “2Θ” and expressed in degrees, as follows: 5.4±0.2°, 11.3±, 13.8±0.2°, 17.1±0.2°, 23.3±0.2°and 27.1±0.2°. [0084] The new solid-state acetone solvate Form A 2 of the present invention can be obtained by crystallization from solutions of pantoprazole sodium salt and acetone. A process for preparation of the new solid-state acetone solvate Form A 2 pentacoordinated square pyramidal sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in acetone; (ii) dissolving the pantoprazole sodium salt in acetone; (iii) optionally filtering the solution of pantoprazole sodium salt and acetone; (iv) crystallizing the new solid-state acetone solvate Form A 2 pentacoordinated square pyramidal sodium aqua complex of pantoprazole; (v) isolating the crystals thus obtained; and (vi) drying the crystals. [0091] In one embodiment of stage (ii) of the process for the preparation of the new solid-state acetone solvate Form A 2 , the suspension of pantoprazole sodium salt and acetone is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain a clear solution. [0092] In one embodiment of stage (iv) of the process for the preparation of the new solid-state acetone solvate Form A 2 , the solution is cooled to from about 70° C. to about −10° C., for example, cooled to about room temperature. [0093] In another embodiment of stage (iv) of the process for the preparation of the new solid-state acetone solvate Form A 2 , the crystallization is induced over time period of about 15 minutes to about 24 hours. In one embodiment, this is performed without stirring the mixture. [0094] In one embodiment of stage (vi) of the process for the preparation of the new solid-state acetone solvate Form A 2 , the isolated crystals are dried at about atmospheric pressure and about room temperature for a time period of from about 1 hour to about 24 hours, for example, for a time period of about 12 hours. [0095] It has been found that by the use of the process of the present invention no decomposition of the new solid-state acetone solvate Form A 2 pentacoordinated square pyramidal sodium aqua complex of pantoprazole takes place and that it has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0096] It has also been found that the new solid-state Form A 2 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0097] The new solid-state acetone solvate Form A 2 pentacoordinated square pyramidal sodium aqua complex of pantoprazole can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state forms monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0098] The new solid-state acetone solvate Form A 2 pentacoordinated square pyramidal sodium aqua complex of pantoprazole can be also converted by the use of the processes of the present invention to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes described herein. [0099] The new solid-state acetone solvate Form A 2 pentacoordinated square pyramidal sodium aqua complex of pantoprazole can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [heading-0100] Solid-State Form A 3 [0101] Another object of this disclosure is to provide a new solid-state acetone solvate pantoprazole sodium aqua complex, solid-state Form A 3 . [0102] The new solid-state acetone solvate Form A 3 , prepared according to the process of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0103] The new solid-state acetone solvate Form A 3 has a characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of the new solid-state acetone solvate Form A 3 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0104] The new solid-state acetone solvate Form A 3 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.4±0.2°; 11.2±0.2°; 16.9±0.2°; 17.6±0.2°; 19.5±0.2°and 26.2±0.2°. [0105] The new solid-state acetone solvate Form A 3 of the present invention can be obtained by crystallization from solution of pantoprazole sodium salt and acetone. A process for the preparation of the new solid-state acetone Form A 3 sodium aqua complex pantoprazole comprises: (i) suspending pantoprazole sodium salt in acetone; (ii) dissolving the pantoprazole sodium salt in acetone; (iii) optionally filtering the solution of pantoprazole sodium salt and acetone; (iv) crystallizing the new solid-state acetone Form A 3 sodium aqua complex pantoprazole; (v) isolating the crystals thus obtained; and (vi) drying the crystals. [0112] In one embodiment of stage (ii) of the process for the preparation of the new solid-state acetone solvate Form A 3 , the suspension of pantoprazole sodium salt and acetone is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain a clear solution. [0113] In one embodiment of stage (iv) of the process for the preparation of the new solid-state acetone solvate Form A 3 , the solution is cooled to from about 70° C. to about −10° C., for example, cooled to room temperature. [0114] In another embodiment of stage (iv) of the process for the preparation of the new solid-state acetone solvate Form A 3 , the crystallization is induced over a time period of from about 15 minutes to about 10 hours, for example, over a time period of about 5 hours. In one embodiment, this is performed while stirring the mixture. [0115] In one embodiment of stage (vi) of the process for the preparation of the new solid-state acetone solvate Form A 3 , the isolated crystals are dried at about atmospheric pressure and about room temperature for a time period of from about 1 hour to about 24 hours, for example, for a time period of about 12 hours. [0116] It has been found that by the use of the process of the present invention no decomposition of the new solid-state acetone solvate Form A 3 takes place, and that the Form A 3 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5 or greater than about 99.9%. [0117] It has also been found that the new solid-state Form A 3 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0118] The new solid-state acetone solvate Form A 3 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0119] The new solid-state acetone solvate Form A 3 can be also converted, by the use of the processes of the present invention, to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes described herein. [0120] The new solid-state acetone solvate Form A 3 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [heading-0121] Solid-State Form A 4 [0122] Another object of this invention is to provide a new solid-state acetone solvate sodium aqua complex of pantoprazole, solid-state Form A 4 . [0123] The new solid-state acetone solvate Form A 4 , prepared according to the process of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0124] The new solid-state acetone solvate Form A 4 has characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of Form A 4 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0125] The new solid-state acetone solvate Form A 4 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.6±0.2°, 15.4±0.2°, 16.8±0.2°; 17.3±0.2°; 19.6±0.2°; 20.9±0.2°; 24.5±0.2°; 30.1±0.2° and 30.6±0.2°. [0126] The new solid-state acetone Form A 4 can be obtained by crystallization from solutions of pantoprazole sodium salt, acetone, and water. A process for the preparation of new solid-state acetone Form A 4 sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in acetone; (ii) dissolving the pantoprazole sodium salt in acetone; (iii) optionally filtering the solution of pantoprazole sodium salt and acetone; (iv) adding water; (v) crystallizing the new solid-state acetone solvate Form A 4 sodium aqua complex of pantoprazole; (vi) isolating the crystals thus obtained; and (vii) drying the crystals. [0134] According to stage (ii) of the process for the preparation of the new solid-state acetone solvate Form A 4 , the suspension of pantoprazole sodium salt and acetone is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain clear solution. [0135] In one embodiment of stage (iv) of the process for the preparation of the new solid-state acetone solvate Form A 4 , water can be added in an amount of about 0.1% to about 5% by volume of acetone, for example, in an amount of about 2.5% by volume of acetone. [0136] In one embodiment of stage (v) of the process for the preparation of the new solid-state acetone solvate Form A 4 , the solution is cooled to from about 70° C. to about −10° C., for example, cooled to about room temperature. [0137] In another embodiment of stage (v) of the process for the preparation of the new solid-state acetone solvate Form A 4 , the crystallization is induced over a time period of from about 15 minutes to about 10 hours, for example, over a timer period of about 5 hours. In one embodiment, this is performed while stirring the mixture. [0138] In one embodiment of stage (vii) of the process for the preparation of the new solid-state acetone solvate Form A 4 , the isolated crystals are dried at about atmospheric pressure and about room temperature for a time period of from about 1 hour to about 24 hours, for example, for a time period of about 12 hours. [0139] It has been found that by the use of the process of the present invention no decomposition of the new solid-state acetone solvate Form A 4 takes place and that the Form A 4 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0140] It has also been found that the new solid-state Form A 4 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0141] The new solid-state acetone solvate Form A 4 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0142] The new solid-state acetone solvate Form A 4 can also be converted by the use of the processes of the present invention to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes described herein. [0143] The new solid-state acetone solvate Form A 4 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [heading-0144] Solid-State Form B 1 [0145] Still another object of this disclosure is to provide a new solid-state methyl acetate solvate hexacoordinated octahedral sodium aqua complex of pantoprazole, solid-state Form B 1 . [0146] The new solid-state methyl acetate solvate Form B 1 , prepared according to the processes of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0147] Single crystals of the new solid-state methyl acetate solvate Form B 1 were prepared by the process of the present invention, and single crystal x-ray diffraction data collected using a Bruker Nonius FR591/KappaCCD diffractometer using CuKα radiation. Basic crystallographic data for the new solid-state methyl acetate solvate Form B 1 are represented in Table 4. TABLE 4 Basic crystallographic data for the new solid-state methyl acetate solvate Form B1 hexacoordinated octahedral sodium aqua complex of pantoprazole. Form B1 Empirical formula [Na(C 16 H 14 F 2 N 3 O 4 S)(OH 2 )].(C 3 H 6 O 2 ) Formula weight 497.45 Temperature 293 (2) K Crystal size 0.15 × 0.20 × 0.40 mm Crystal system, space Monoclinic, P 2 1 /a group Unit cell dimensions a = 13.31(1) Å b = 10.47(1) Å c = 17.68(2) Å β = 109.9(1)° α = γ = 90° Volume 2316.8(1) Å 3 Z 4 Calculated density 1.43 gcm −3 [0148] The new solid-state methyl acetate solvate Form B 1 has a characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of the new solid-state methyl acetate solvate Form B 1 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0149] The new solid-state methyl acetate solvate Form B 1 has characteristic x-ray powder diffraction peaks, designated by “2Θ” and expressed in degrees as follows: 5.3±0.2°, 9.9±0.2°, 11.1±0.2°, 13.3±0.2°, 15.8±0.2°, 19.8±0.2°, 21.4±0.2°, 26.1±0.2°, 26.5±0.2°, 28.90.2°and 30.5±0.2°. [0150] The new solid-state methyl acetate solvate Form B 1 of the present invention can be obtained by crystallization from solutions of pantoprazole sodium salt and methyl acetate. A process for the preparation of the new solid-state methyl acetate solvate Form B 1 hexacoordinated octahedral sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in methyl acetate; (ii) dissolving the pantoprazole sodium salt in methyl acetate; (iii) optionally filtering the solution of pantoprazole sodium salt and methyl acetate; (iv) crystallizing the new solid-state methyl acetate solvate Form B 1 hexacoordinated octahedral sodium aqua complex of pantoprazole; (v) isolating the crystals thus obtained; and (vi) drying the crystals. [0157] In one embodiment of stage (ii) of the process for the preparation of the new solid-state methyl acetate solvate Form B 1 , the suspension of pantoprazole sodium salt and methyl acetate is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain a clear solution. [0158] In one embodiment of stage (iv) of the process for the preparation of the new solid-state methyl acetate solvate Form B 1 , the solution is cooled to from about 70° C. to about −10° C., for example, cooled to about room temperature. [0159] In another embodiment of stage (iv) of the process for the preparation of the new solid-state methyl acetate solvate Form B 1 , the crystallization is induced over a period of time from about 15 minutes to about 24 hours. In one embodiment, this is performed without stirring the mixture. [0160] In one embodiment of stage (vi) of the process for the preparation of the new solid-state methyl acetate solvate Form B 1 , the isolated crystals are dried at about atmospheric pressure and about room temperature for a time period of from about 1 hour to about 24 hours, for example, for a time period of about 12 hours. [0161] It has been found that by the use of the process of the present invention, no decomposition of the new solid-state methyl acetate solvate Form B 1 takes place and that the Form B 1 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0162] It has also been found that the new solid-state Form B 1 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0163] The new solid-state methyl acetate solvate Form B 1 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e., it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0164] The new solid-state methyl acetate solvate Form B 1 can be also converted by the use of the processes of the present invention, to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes described herein. [0165] The new solid-state methyl acetate solvate Form B 1 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [heading-0166] Solid-State Form B 2 [0167] Another object of this disclosure is to provide a new solid-state methyl acetate solvate sodium aqua complex of pantoprazole, solid-state Form B 2 . [0168] The new solid-state methyl acetate solvate Form B 2 , prepared according to the processes of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0169] The new solid-state methyl acetate solvate Form B 2 has a characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of the new solid-state methyl acetate solvate Form B 2 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0170] The new solid-state methyl acetate solvate Form B 2 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.4±0.2°, 11.2±0.2°, 13.3±0.2°, 16.8±0.2°, 20.5±0.2°, 22.4±0.2°and 26.6±0.2°. [0171] The new solid-state methyl acetate solvate Form B 2 of the present invention can be obtained by crystallization from solutions of pantoprazole sodium salt and methyl acetate. A process for preparation of the new solid-state methyl acetate solvate Form B 2 sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in methyl acetate; (ii) dissolving the pantoprazole sodium salt in methyl acetate; (iii) optionally filtering the solution of pantoprazole sodium salt and methyl acetate; (iv) crystallizing the new solid-state methyl acetate solvate Form B 2 sodium aqua complex of pantoprazole; (v) isolating the crystals thus obtained; and (vi) drying the crystals. [0178] In one embodiment of stage (ii) of the process for the preparation of the new solid-state methyl acetate solvate Form B 2 , the suspension of pantoprazole sodium salt and methyl acetate is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain clear solution. [0179] In one embodiment of stage (iv) of the process for the preparation of the new solid-state methyl acetate solvate Form B 2 , the solution is cooled to from about 70° C. to about −10° C., for example, cooled to about room temperature. [0180] In one embodiment of stage (iv) of the process for the preparation of the new solid-state methyl acetate solvate Form B 2 , the crystallization is induced over a time period of from about 15 minutes to about 10 hours, preferably over a time period of about 5 hours. [0181] In another embodiment of stage (vi) of the process for the preparation of the new solid-state methyl acetate solvate Form B 2 , the isolated crystals, are dried at about atmospheric pressure and about room temperature for a time period of from about 1 hour to about 24 hours, for example, for a timer period of about 12 hours. In one embodiment, this is performed while stirring the mixture. [0182] It has been found that by the use of the process of the present invention no decomposition of the new solid-state methyl acetate solvate Form B 2 takes place and that the Form B 2 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0183] It has also been found that the new solid-state Form B 2 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0184] The new solid-state methyl acetate solvate Form B 2 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0185] The new solid-state methyl acetate solvate Form B 2 can also be also converted by the use of the processes of the present invention to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes described herein. [0186] The new solid-state methyl acetate solvate Form B 2 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [0187] Solid-state Form B 3 [0188] Another object of this disclosure is to provide a new solid-state methyl acetate solvate sodium aqua complex of pantoprazole, solid-state Form B 3 . [0189] The new solid-state methyl acetate solvate Form B 3 , prepared according to the process of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0190] The new solid-state methyl acetate solvate Form B 3 of the present invention has a characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of the new solid-state methyl acetate solvate Form B 3 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0191] The new solid-state methyl acetate solvate Form B 3 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.5±0.2°, 9.5±0.2°, 11.9±0.2°, 15.3±0.2°, 19.2±0.2°, 23.9±0.2°and 33.0±0.2°. [0192] The new solid-state methyl acetate solvate Form B 3 of present invention can be obtained by crystallization from solutions of pantoprazole sodium salt, methyl acetate and water. A process for the new solid-state methyl acetate solvate Form B 3 sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in methyl acetate; (ii) dissolving the pantoprazole sodium salt in methyl acetate; (iii) optionally filtering the solution of pantoprazole sodium salt and methyl acetate; (iv) adding water; (v) crystallizing the new solid-state methyl acetate Form B 3 sodium aqua complex of pantoprazole; (vi) isolating the crystals thus obtained; and (vii) drying the crystals. [0200] In one embodiment of stage (ii) of the process for the preparation of the new solid-state methyl acetate solvate Form B 3 , the suspension of pantoprazole sodium salt and methyl acetate is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain clear solution. [0201] In one embodiment of stage (iv) of the process for the preparation of the new solid-state methyl acetate solvate Form B 3 , water can be added in an amount of about 0.1% to about 5% by volume of methyl acetate, for example, in an amount of about 2.5% by volume of methyl acetate. [0202] In one embodiment of stage (v) of the process for the preparation of the new solid-state methyl acetate solvate Form B 3 , the solution is cooled to from about 70° C. to about −10° C., for example, cooled to room temperature. [0203] In another embodiment of stage (v) of the process for the preparation of the new solid-state methyl acetate solvate Form B 3 , the crystallization is induced over a time period of from about 15 minutes to about 10 hours, for example, over a time period of about 5 hours. In one embodiment, this is performed while stirring the mixture. [0204] In one embodiment of stage (vii) of the process for the preparation of the new solid-state methyl acetate solvate Form B 3 , the isolated crystals are dried at about atmospheric pressure and about room temperature for a time period of from about 1 hour to about 24 hours, for example for a time period of about 12 hours. [0205] It has been found that by the use of the process of the present invention no decomposition of the new solid-state methyl acetate solvate Form B 3 takes place and that the Form B 3 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0206] It has also been found that the new solid-state Form B 3 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0207] The new solid-state methyl acetate solvate Form B 3 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0208] The new solid-state methyl acetate solvate Form B 3 can also be converted by the use of the processes of the present invention to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes described herein. [0209] The new solid-state methyl acetate solvate Form B 3 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [heading-0210] Solid-State Form C 1 [0211] Still another object of this disclosure is to provide a new solid-state methyl ethyl ketone solvate hexacoordinated octahedral sodium aqua complex of pantoprazole, solid-state Form C 1 . [0212] The new solid-state methyl ethyl ketone solvate Form C 1 , prepared according to the process of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0213] Single crystals of the new solid-state methyl ethyl ketone solvate Form C 1 were prepared by the process of the present invention, and single crystal x-ray diffraction data collected using a Bruker Nonius FR591/KappaCCD diffractometer using CuKα radiation. Basic crystallographic data for the new solid-state methyl acetate solvate Form C 1 are represented in Table 5. TABLE 5 Basic crystallographic data for the new solid-state methyl ethyl ketone solvate Form C1 hexacoordinated octahedral sodium aqua complex of pantoprazole. Form C1 Empirical formula [Na(C 16 H 14 F 2 N 3 O 4 S)(OH 2 ) 2 ] × CH 3 CH 2 COCH 3 Formula weight 513.49 Temperature 293 (2) K Crystal size 0.05 × 0.1 × 0.20 mm Crystal system, space Monoclinic, P 2 1 /a group Unit cell dimensions a = 13.51(1) Å b = 10.66(1) Å c = 16.16(2) Å β = 92.3(1)° α = γ = 90° Volume 2324.8(10) Å 3 Z 4 Calculated density 1.47 gcm −3 [0214] The new solid-state methyl ethyl ketone Form C 1 has a characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of the new solid-state methyl ethyl ketone solvate Form C 1 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0215] The new solid-state methyl ethyl ketone solvate Form C 1 has characteristic x-ray powder diffraction peaks designated by “ 20 ” and expressed in degrees as follows: 5.5±0.2°, 10.4±0.2°, 10.9±0.2°, 19.2±0.2°, 20.5±0.2°, 21.4±0.2°, 24.6±0.2°, 29.7±0.2°, 33.0±0.2°and 33.9±0.2°. [0216] The new solid-state methyl ethyl ketone solvate Form C 1 of the present invention can be obtained by crystallization from solutions of pantoprazole sodium salt and methyl ethyl ketone. [0217] A process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 1 hexacoordinated octahedral sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in methyl ethyl ketone; (ii) dissolving the pantoprazole sodium salt in methyl ethyl ketone; (iii) optionally filtering the solution of pantoprazole sodium salt and methyl ethyl ketone; (iv) optionally adding water (v) crystallizing the new solid-state methyl ethyl ketone solvate Form C 1 hexacoordinated octahedral sodium aqua complex of pantoprazole; (vi) isolating the crystals thus obtained; and (vii) drying the crystals. [0225] In one embodiment of stage (ii) of the process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 1 , the suspension of pantoprazole sodium salt and methyl ethyl ketone is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain a clear solution. [0226] In one embodiment of step (iv) of the process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 1 , water can be added in an amount of about 0.1% to about 5% by volume of the methyl ethyl ketone, for example, in an amount of about 2.5% by volume of the methyl ethyl ketone. [0227] In one embodiment of stage (v) of the process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 1 , the solution is cooled to from about 70° C. to about −10° C., for example, cooled to about room temperature. [0228] In another embodiment of stage (v) of the process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 1 , the crystallization is induced over a period of time of from about 15 minutes to about 24 hours. In one embodiment, this is performed without stirring the mixture. [0229] In one embodiment of stage (vii) of the process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 1 , the isolated crystals are dried at about atmospheric pressure and about room temperature for a time period of from about 1 hour to about 24 hours, for example, for a time period of about 12 hours. [0230] It has been found that by the use of the process of the present invention, no decomposition of the new solid-state methyl ethyl ketone solvate Form C 1 , takes place and that the Form C 1 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0231] It has also been found that the new solid-state Form C 1 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0232] The new solid-state methyl ethyl ketone solvate Form C 1 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0233] The new solid-state methyl ethyl ketone solvate Form C 1 can also be converted by the use of the processes of the present invention, to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes describer herein. [0234] The new solid-state methyl ethyl ketone solvate Form C 1 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [heading-0235] Solid-State Form C 2 [0236] Another object of this disclosure is to provide a new solid-state methyl ethyl ketone solvate sodium aqua complex of pantoprazole, solid-state Form C 2 . [0237] The new solid-state methyl ethyl ketone solvate Form C 2 , prepared according to the process of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0238] The new solid-state methyl ethyl ketone solvate Form C 2 of the present invention has a characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of the new solid-state methyl ethyl ketone solvate Form C 2 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0239] The new solid-state methyl ethyl ketone solvate Form C 2 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.4±0.2°, 10.7±0.2°, 12.3±0.2°, 15.8±0.2°, 16.7±0.2°, 20.1±0.2° and 22.5±0.2°. [0240] The new solid-state methyl ethyl ketone solvate Form C 2 can be obtained by crystallization from solutions of pantoprazole sodium salt and methyl ethyl ketone. A process for the preparation of new solid-state methyl ethyl ketone solvate Form C 2 sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in methyl ethyl ketone; (ii) dissolving the pantoprazole sodium salt in methyl ethyl ketone; (iii) optionally filtering the solution of pantoprazole sodium salt and methyl ethyl ketone; (iv) crystallizing the new solid-state methyl ethyl ketone solvate Form C 2 sodium aqua complex of pantoprazole; (v) isolating the crystals thus obtained; and (vi) drying the crystals. [0247] In one embodiment of stage (ii) of the process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 2 , the suspension of pantoprazole sodium salt and methyl ethyl ketone is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain clear solution. [0248] In one embodiment of stage (iv) of the process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 2 , the solution is cooled to from about 70° C. to about −10° C., for example cooled to room temperature. [0249] In another embodiment of stage (iv) of the process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 2 , the crystallization is induced over a time period of from about 15 minutes to about 10 hours, for example, over a time period of about 5 hours. In one embodiment, this is performed while stirring the mixture. [0250] In one embodiment of stage (vi) of the process for the preparation of the new solid-state methyl ethyl ketone solvate Form C 2 , the isolated crystals are dried at about atmospheric pressure and about room temperature for a time period of from about 1 hour to about 24 hours, for example, for a time period of about 12 hours. [0251] It has been found that by the use of the process of the present invention no decomposition of the new solid-state methyl ethyl ketone solvate Form C 2 takes place and that the Form C 2 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0252] It has also been found that the new solid-state Form C 2 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0253] The new solid-state methyl ethyl ketone solvate Form C 2 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0254] The new solid-state methyl ethyl ketone solvate Form C 2 can be also converted by the use of the processes of the present invention, to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes describer herein. [0255] The new solid-state methyl ethyl ketone solvate Form C 2 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [heading-0256] Solid-State Form D 1 [0257] Still another object of this disclosure is to provide a new solid-state diethyl ketone solvate hexacoordinated octahedral sodium aqua complex of pantoprazole, solid-state Form Dl. [0258] The new solid-state diethyl ketone solvate Form D 1 , prepared according to the processes of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0259] Single crystals of a new solid-state diethyl ketone solvate Form D 1 were prepared and single crystal x-ray diffraction data collected using a Bruker Nonius FR591/KappaCCD diffractometer using CuKα radiation. [0260] Basic crystallographic data for the new solid-state diethyl ketone solvate Form D 1 are represented in Table 6. TABLE 6 Basic crystallographic data for the new solid-state diethyl ketone solvate Form D1 hexacoordinated octahedral sodium aqua complex of pantoprazole. Form D1 Empirical formula [Na(C 16 H 14 F 2 N 3 O 4 S)(OH 2 )] × (CH 3 CH 2 ) 2 CO Formula weight 527.51 Temperature 100 (2) K Crystal size 0.1 × 0.2 × 0.40 mm Crystal system, space Monoclinic, P 2 1 /a group Unit cell dimensions a = 13.42(1) Å b = 10.85(1) Å c = 17.36(2) Å β = 102.5(1)° α = γ = 90° Volume 2469.0(1) Å 3 Z 4 Calculated density 1.42 gcm −3 [0261] The new solid-state diethyl ketone solvate Form D 1 has a characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of the new solid-state diethyl ketone solvate Form D 1 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0262] The new solid-state diethyl ketone solvate Form D 1 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.2±0.2°, 10.4±0.2°, 12.3±0.2°, 13.1±0.2°, 15.1±0.2°, 15.8±0.2°, and 25.0±0.2°. [0263] The new solid-state diethyl ketone solvate Form D 1 of the present invention can be obtained by crystallization from solutions of pantoprazole sodium salt and diethyl ketone. A process for the preparation of the new solid-state diethyl ketone solvate Form D 1 hexacoordinated octahedral sodium aqua complex of pantoprazole comprises: (i) suspending pantoprazole sodium salt in diethyl ketone; (ii) dissolving the pantoprazole sodium salt in diethyl ketone; (iii) filtering the solution of pantoprazole sodium salt and diethyl ketone; (iv) crystallizing the new solid-state diethyl ketone solvate Form D 1 hexacoordinated octahedral sodium aqua complex of pantoprazole; (v) isolating the crystals thus obtained; and (vi) drying the crystals. [0270] In one embodiment of stage (ii) of the process for the preparation of the new solid-state diethyl ketone solvate Form D 1 , the suspension of pantoprazole sodium salt and diethyl ketone is heated to a temperature of from about 30° C. to about reflux for a time sufficient to obtain clear solution. [0271] In one embodiment of stage (iv) the process for the preparation of the new solid-state diethyl ketone solvate Form D 1 , the solution is cooled to from about 70° C. to about −10° C., for example, cooled to room temperature. [0272] In another embodiment of stage (iv) of the process for the preparation of the new solid-state diethyl ketone solvate Form D 1 , the crystallization is induced stirring over a time period of from about 15 minutes to about 24 hours. This may be performed with or without stirring. [0273] In one embodiment of stage (vi) of the process for the preparation of the new solid-state diethyl ketone solvate Form D 1 , the isolated crystals are dried at about atmospheric pressure and about room temperature for a time period of from about 1 hour to about 24 hours, for example, for a timer period of about 12 hours. [0274] It has been found that by the use of the process of the present invention no decomposition of the new solid-state diethyl ketone solvate Form D 1 takes place and that the Form D 1 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0275] It has also been found that the new solid-state Form D 1 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0276] The new solid-state diethyl ketone solvate Form D 1 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0277] The new solid-state diethyl ketone solvate Form D 1 can also be converted by the use of the processes of the present invention to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes describer herein. [0278] The new solid-state diethyl ketone solvate Form D 1 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [heading-0279] Solid-State Form E 1 [0280] Still another object of this disclosure is to provide a desolvated sodium aqua complex of pantoprazole, solid-state Form E 1 . [0281] The desolvated Form E 1 , prepared according to the processes of the present invention, has the form of a flowable crystalline powder having the property of flowability, i.e. it is obtained in a “free-flow” form which is not statically chargeable. [0282] The desolvated Form E 1 has a characteristic x-ray powder pattern obtained by x-ray diffraction on a powder sample of the desolvated Form E 1 . X-ray powder patterns were collected using a Philips X'PertPRO powder diffractometer using CuKα radiation. [0283] The desolvated Form E 1 has characteristic x-ray powder diffraction peaks designated by “ 20 )” and expressed in degrees as follows: 5.4±0.2°, 11.6±0.2, 12.4±0.2°, 13.6±0.2, 16.0±0.2°, 23.3±0.2° and 28.7±0.2°. [0284] The desolvated Form E 1 of the present invention can be obtained by drying solvates of pantoprazole sodium aqua complexes, including, but not limited to, the solvates described herein. [0285] A process for the preparation of the desolvated Form E 1 comprises drying solvates of pantoprazole sodium aqua complexes at temperatures of from about 20° C. to about 120° C., for example, at about 60° C., and at pressures of from about 1 mbar to about 10 mbar, for example, at about 5 mbar for a time period of from about 1 hour to about 6 hours, for example, for about 3 hours. [0286] The obtained crystals of Form E 1 have characteristic x-ray powder diffraction peaks, (2Θ) expressed in degrees, at: 5.4±0.2°, 11.6±0.2°, 12.4±0.2°, 13.6±0.2°, 16.0±0.2°, 23.3±0.2° and 28.7±0.2°. [0287] It has been found that by use of the process of the present invention no transformation of the desolvated Form E 1 takes place and the Form E 1 product that has a solid-state purity of greater than about 95.0%, greater than about 95.0%, greater than about 99.9%, or that it is solid-state pure. [0288] It has also been found that by the use of the process of the present invention no decomposition of the desolvated Form E 1 takes place and that the Form E 1 product has a chemical purity of greater than about 98.0%, greater than about 99.0%, greater than about 99.5%, or greater than about 99.9%. [0289] It has also been found that the new solid-state Form E 1 is stable under normal storage conditions (typically, but not limited to, temperatures of about 20° C. to about 30° C., and relative humidity of about 30% to about 60%), and does not convert into other known solid-state forms of pantoprazole sodium under crushing or compressing. [0290] The desolvated Form E 1 can be converted to the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt, i.e. it may be used as a raw material for the preparation of the solid-state monohydrate and sesquihydrate forms of pantoprazole sodium salt. [0291] The desolvated Form E 1 can be also converted by the use of the processes of the present invention to the new solid-state solvate forms of pantoprazole hexacoordinated octahedral sodium aqua complexes and to the new solid-state solvate forms of pantoprazole pentacoordinated square pyramidal sodium aqua complexes described herein. [0292] The desolvated Form E 1 can be converted into other pharmaceutically acceptable salts of pantoprazole by means of conventional processes, for example, it may be used as a raw material for the preparation of the magnesium salt of pantoprazole. [heading-0293] Compositions of the New Solid-State Forms of Pantoprazole [0294] The new solid-state Forms N, A 1 , A 2 , A 3 , A 4 , B 1 , B 2 , B 3 , C 1 , C 2 , D 1 , and E 1 of sodium aqua complexes of pantoprazole of the present invention can be utilized in the preparation of rapid, controlled and sustained release pharmaceutical compositions, suitable for oral, rectal, parenteral, transdermal, buccal, nasal, sublingual, subcutaneous or intravenous administration. For example, the compostitions may include one or more of solid-state Form N and solid-state Form E 1 . [0295] The compositions may be administered orally, in the form of rapid or controlled release tablets, microparticles, mini tablets, capsules, sachets, and oral solutions or suspensions, or powders for the preparation thereof. In addition to the new solid-state forms of pantoprazole of the present invention as the active substance, oral preparations may optionally include various standard pharmaceutical carriers and excipients, such as binders, fillers, buffers, lubricants, glidants, dyes, disintegrants, odorants, sweeteners, surfactants, mold release agents, antiadhesive agents and coatings. Some excipients may have multiple roles in the compositions, e.g., act as both binders and disintegrants. [0296] Examples of pharmaceutically acceptable disintegrants for oral compositions useful in the present invention include, but are not limited to, starch, pre-gelatinized starch, sodium starch glycolate, sodium carboxymethylcellulose, croscarmellose sodium, microcrystalline cellulose, alginates, resins, surfactants, effervescent compositions, aqueous aluminum silicates and crosslinked polyvinylpyrrolidone. [0297] Examples of pharmaceutically acceptable binders for oral compositions useful herein include, but are not limited to, acacia; cellulose derivatives, such as methylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose, hydroxypropylcellulose or hydroxyethylcellulose; gelatin, glucose, dextrose, xylitol, polymethacrylates, polyvinylpyrrolidone, sorbitol, starch, pre-gelatinized starch, tragacanth, xanthane resin, alginates, magnesium-aluminum silicate, polyethylene glycol or bentonite. [0298] Examples of pharmaceutically acceptable fillers for oral compositions include, but are not limited to, lactose, anhydrolactose, lactose monohydrate, sucrose, dextrose, mannitol, sorbitol, starch, cellulose (particularly microcrystalline cellulose), dihydro- or anhydro-calcium phosphate, calcium carbonate and calcium sulfate. [0299] Examples of pharmaceutically acceptable lubricants useful in the compositions of the invention include, but are not limited to, magnesium stearate, talc, polyethylene glycol, polymers of ethylene oxide, sodium lauryl sulfate, magnesium lauryl sulfate, sodium oleate, sodium stearyl fumarate, DL-leucine and colloidal silicon dioxide [0300] Examples of suitable pharmaceutically acceptable odorants for the oral compositions include, but are not limited to, synthetic aromas and natural aromatic oils such as extracts of oils, flowers, fruits and combinations thereof. Examples are vanilla and fruit aromas, including banana, apple, sour cherry, peach and similar aromas. Their use depends on many factors, the most important being the organoleptic acceptability for the population that will be taking the pharmaceutical compositions. [0301] Examples of suitable pharmaceutically acceptable dyes for the oral compositions include, but are not limited to, synthetic and natural dyes such as titanium dioxide, beta-carotene and extracts of grapefruit peel. [0302] Examples of useful pharmaceutically acceptable coatings for the oral compositions, typically used to facilitate swallowing, modify the release properties, improve the appearance, and/or mask the taste of the compositions include, but are not limited to, hydroxypropylmethylcellulose, hydroxypropylcellulose and acrylate-methacrylate copolymers. [0303] Suitable examples of pharmaceutically acceptable sweeteners for the oral compositions include, but are not limited to, aspartame, saccharin, saccharin sodium, sodium cyclamate, xylitol, mannitol, sorbitol, lactose and sucrose. [0304] Suitable examples of pharmaceutically acceptable buffers include, but are not limited to, citric acid, sodium citrate, sodium bicarbonate, dibasic sodium phosphate, magnesium oxide, calcium carbonate and magnesium hydroxide. [0305] Suitable examples of pharmaceutically acceptable surfactants include, but are not limited to, sodium lauryl sulfate and polysorbates. [0306] Compositions of the solid-state forms of pantoprazole of the present invention can also be administered intravenously or intraperitoneally, by infusion or injection. Dispersions can also be prepared in a liquid carrier or intermediate, such as glycerin, liquid polyethylene glycols, triacetin oils, and mixtures thereof. To improve storage stability, such preparations may also contain a preservative to prevent the growth of microorganisms. [0307] Pharmaceutical compositions suitable for injection or infusion may be in the form of a sterile aqueous solution, a dispersion or a sterile powder that contains the active ingredient, adjusted, if necessary, for preparation of such a sterile solution or dispersion suitable for infusion or injection. This may optionally be encapsulated into liposomes. In all cases, the final preparation must be sterile, liquid, and stable under production and storage conditions. [0308] The liquid carrier or intermediate can be a solvent or liquid dispersive medium that contains, for example, water, ethanol, a polyol (e.g. glycerol, propylene glycol or the like), vegetable oils, non-toxic glycerine esters and suitable mixtures thereof. Suitable flowability may be maintained, by generation of liposomes, administration of a suitable particle size in the case of dispersions, or by the addition of surfactants. Prevention of the action of micro-organisms can be achieved by the addition of various antibacterial and antifungal agents, e.g. paraben, chlorobutanol, or sorbic acid. In many cases isotonic substances are recommended, e.g. sugars, buffers and sodium chloride to assure osmotic pressure similar to those of body fluids, particularly blood. Prolonged absorption of such injectable mixtures can be achieved by introduction of absorption-delaying agents, such as aluminium monostearate or gelatin. [0309] Sterile injectable solutions can be prepared by mixing the solid-state Forms of pantoprazole with an appropriate solvent and one or more of the aforementioned excipients, followed by sterile filtering. In the case of sterile powders suitable for use in the preparation of sterile injectable solutions, preferable preparation methods include drying in vacuum and lyophilization, which provide powdery mixtures of the isostructural pseudopolymorphs and desired excipients for subsequent preparation of sterile solutions. [0310] The solid-state forms of pantoprazole of the present invention may also be used for the preparation of locally acting, topical compositions. Such compositions may also contain other pharmaceutically acceptable excipients, such as polymers, oils, liquid carriers, surfactants, buffers, preservatives, stabilizers, antioxidants, moisturizers, emollients, colorants and odorants. Examples of pharmaceutically acceptable polymers suitable for such topical compositions include, but are not limited to, acrylic polymers; cellulose derivatives, such as carboxymethylcellulose sodium, methylcellulose or hydroxypropylcellulose; natural polymers, such as alginates, tragacanth, pectin, xanthan and cytosan. [0311] Examples of suitable pharmaceutically acceptable oils which are so useful include but are not limited to, mineral oils, silicone oils, fatty acids, alcohols, and glycols. [0312] Examples of suitable pharmaceutically acceptable liquid carriers include, but are not limited to, water, alcohols or glycols such as ethanol, isopropanol, propylene glycol, hexylene glycol, glycerol and polyethylene glycol, or mixtures thereof in which the pseudopolymorph is dissolved or dispersed, optionally with the addition of non-toxic anionic, cationic or non-ionic surfactants, and inorganic or organic buffers. [0313] Suitable examples of pharmaceutically acceptable preservatives include, but are not limited to, various antibacterial and antifungal agents such as solvents, for example ethanol, propylene glycol, benzyl alcohol, chlorobutanol, quaternary ammonium salts, and parabens (such as methyl paraben, ethyl paraben, propyl paraben, etc.). [0314] Suitable examples of pharmaceutically acceptable stabilizers and antioxidants include, but are not limited to, ethylenediaminetetraacetic acid (EDTA), thiourea, tocopherol and butyl hydroxyanisole. [0315] Suitable examples of pharmaceutically acceptable moisturizers include, but are not limited to, glycerine, sorbitol, urea and polyethylene glycol. [0316] Suitable examples of pharmaceutically acceptable emollients include, but are not limited to, mineral oils, isopropyl myristate, and isopropyl palmitate. [0317] The use of dyes and odorants in topical compositions of the present invention depends on many factors of which the most important is organoleptic acceptability to the population that will be using the pharmaceutical compositions. [0318] The therapeutically acceptable quantity of the solid-state forms of pantoprazole of the present invention administered varies, dependent on the selected compound, the mode of administration, treatment conditions, age and status of the patient or animal species, and is subject to the final decision of the physician, clinician or veterinary doctor monitoring the course of treatment. For example, the solid-state forms of pantoprazole may be formulated in a dosage form that contains from about 5 to about 300 mg of the active substance per unit dose. [0319] The present invention also relates to methods for inhibiting gastric acid secretion, protecting the stomach and intestines, and treating gastric ulcers in a patient in need of such treatment by administering to the patient a therapeutically effective amount of one or more of the new solid-state sodium aqua complexes of pantoprazole Forms N, A 1 , A 2 , A 3 , A 4 , B 1 , B 2 , B 3 , C 1 , C 2 , D 1 , or E 1 or a pharmaceutical composition containing a therapeutically effective amount of one or more of the new solid-state sodium aqua complexes of pantoprazole Forms N, A 1 , A 2 , A 3 , A 4 , B 1 , B 2 , B 3 , C 1 , C 2 , D 1 , and E 1 . For example, the methods relate to administering one or more of solid-state Form N and solid-state Form E 1 . EXAMPLES [0320] The present invention is illustrated but in no way limited by the following examples. Example 1 [0321] Pantoprazole sodium (0.4 g) was dissolved in n-butylacetate (5 ml). After cooling to room temperature, the solution was filtered and 0.2 ml of demineralized water was added. The resulting mixture was left at the same temperature for 24 hours. The crystals obtained were separated by suction and dried to yield 0.29 g of Form N crystals. [0322] Basic crystallographic data for the new solid-state Form N complex are represented in Table 1. [0323] The new solid-state Form N complex has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.3±0.2°, 13.1±0.2°, 16.9±0.2°, 20.5±0.2°, 21.6±0.2°and 25.1±0.2°. Example 2 [0324] Pantoprazole sodium (5.0 g) was dissolved in n-butylacetate (190 ml) and 2.5 ml of water was added. After cooling to room temperature, the solution was filtered and then stirred for 5 hours at the same temperature. The obtained suspension was filtered, separated, and the separated crystals were washed with n-butylacetate and dried at 60° C. under a vacuum of 5 mbar for 3 hours. Yield: 4.6 g of Form N crystals. [0325] The x-ray powder pattern of the thus obtained sample corresponds to the x-ray powder pattern of the solid-state Form N product obtained in Example 1. Example 3 [0326] Crude pantoprazole sodium (10.0 g) was dissolved in ethylacetate (400 ml) and 2.0 ml of water was added. After cooling to room temperature, the solution was filtered and then stirred for 5 hours at the same temperature. The obtained suspension was filtered, and the separated crystals were washed with ethylacetate and dried at 80° C. under a vacuum of 5 mbar for 1 hour. Yield: 8.7 g of Form N crystals. [0327] The x-ray powder pattern of the thus obtained sample corresponds to the x-ray powder pattern of the solid-state Form N product obtained in Example 1. Example 4 [0328] Pantoprazole sodium (0.40 g) was dissolved in acetone (10 ml). After cooling to room temperature, the solution was left at the same temperature for 12 hours. The crystals obtained were separated by suction and dried at room temperature and atmospheric pressure for 12 hours, to yield 0.32 g of Form A 1 crystals. [0329] Basic crystallographic data for the new solid-state acetone solvate Form A 1 are represented in Table 2. [0330] The new solid-state acetone solvate Form A 1 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.6±0.2°, 11.9±0.2°, 12.9±0.2°, 13.8±0.2°, 15.4±0.2°, 16.4±0.2° and 26.1±0.2°. Example 5 [0331] Crude pantoprazole sodium (0.40 g) was dissolved in acetone (7.5 ml). After cooling to room temperature, the solution was left at the same temperature for 24 hours. The crystals obtained were separated by suction and dried at room temperature and atmospheric pressure for 6 hours to yield 0.36 g of Form A 2 crystals. [0332] Basic crystallographic data for the new solid-state acetone solvate Form A 2 are represented in Table 3. [0333] The new solid-state acetone solvate Form A 2 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.4±0.2°, 11.3±0.2°, 13.8±0.2°, 17.1±0.2°, 23.3±0.2° and 27.1±0.2°. Example 6 [0334] Crude pantoprazole sodium (5.0 g) was dissolved in acetone (50 ml). After cooling to room temperature, the solution was filtered and stirred for 5 hours at the same temperature. The obtained suspension was filtered. The crystals obtained were separated, washed with methyl acetate, and dried at room temperature and atmospheric pressure for 12 hours. Yield: 4.8 g of Form A 3 crystals. [0335] The new solid-state acetone solvate Form A 3 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.4±0.2°; 13.8±0.2°; 16.2±0.2° and 26.2±0.2°. Example 7 [0336] Crude pantoprazole sodium (5.0 g) was dissolved in acetone (50 ml) and 2.5 ml of water was added. After cooling to room temperature, the solution was filtered and stirred for 5 hours at the same temperature. The obtained suspension was filtered. The separated crystals were washed with acetone and dried at room temperature and atmospheric pressure for 24 hours. Yield: 4.9 g of Form A 4 crystals. [0337] The new solid-state acetone solvate Form A 4 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.6±0.2°, 15.4±0.2°, 16.8±0.2°; 17.3±0.2°; 19.6±0.2°; 20.9±0.2°; 24.5±0.2°; 30.1±0.2° and 30.6±0.2°. Example 8 [0338] Pantoprazole sodium (0.10 g) was dissolved in methyl acetate (5 ml). After cooling to room temperature, the solution was filtered and left at the same temperature for 24 hours. The crystals obtained were separated by suction and dried at room temperature and atmospheric pressure for 18 hours to yield 0.036 g of Form B 1 crystals. [0339] Basic crystallographic data for the new solid-state methyl acetate solvate Form B 1 are represented in Table 4. [0340] The new solid-state methyl acetate solvate Form B 1 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.3±0.2°, 9.9±0.2°, 11.1±0.2°, 13.3±0.2°, 15.8±0.2°, 19.8±0.2°, 21.4±0.2°, 26.1±0.2°, 26.5±0.2°, 28.9±0.2°and 30.5±0.2°. Example 9 [0341] Pantoprazole sodium (5.0 g) was dissolved in methyl acetate (50 ml). After cooling to room temperature, the solution was filtered and stirred for 5 hours at the same temperature. The obtained suspension was filtered. The separated crystals were washed with methyl acetate and dried at room temperature and atmospheric pressure for 10 hours. Yield: 4.7 g of Form B 2 crystals. [0342] The new solid-state methyl acetate solvate Form B 2 has values of characteristic x-ray powder diffraction peaks designated by “ 2 Θ” and expressed in degrees as follows: 5.4±0.2°, 11.2±0.2°, 13.3±0.2°, 16.8±0.2°, 20.5±0.2°, 22.4±0.2° and 26.6±0.2°. Example 10 [0343] Crude pantoprazole sodium (5.0 g) was dissolved in methyl acetate (50 ml). After cooling to room temperature, the solution was filtered and stirred for 5 hours at the same temperature. The obtained suspension was filtered. The separated crystals were washed with methyl acetate and dried at room temperature and atmospheric pressure for 5 hours. Yield: 4.4 g of Form B 2 crystals. [0344] The x-ray powder pattern of the thus obtained sample corresponds to the x-ray powder pattern of the new solid-state methyl acetate solvate Form B 2 product obtained in Example 9. Example 11 [0345] Pantoprazole sodium (5.0 g) was dissolved in methyl acetate (50 ml) and 2.5 ml of water was added. After cooling to room temperature, the solution was filtered and mixed for 5 hours at the same temperature. The obtained suspension was filtered, and the separated crystals were washed with methyl acetate and dried at room temperature and atmospheric pressure for 10 hours. Yield: 4.6 g of Form B 3 crystals. [0346] The new solid-state methyl acetate solvate Form B 3 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.5±0.2°, 9.5±0.2°, 11.9±0.2°, 15.3±0.2°, 19.2±0.2°, 23.9±0.2° and 33.0±0.2°. Example 12 [0347] Crude pantoprazole sodium (5.0 g) was dissolved in methyl acetate (50 ml) and 2.5 ml of water was added. After cooling to room temperature, the solution was filtered and mixed for 5 hours at the same temperature. The obtained suspension was filtered. The separated crystals were washed with methyl acetate and dried at room temperature and atmospheric pressure for 16 hour. Yield: 4.4 g of Form B 3 crystals. [0348] The x-ray powder pattern of the thus obtained sample corresponds to the x-ray powder pattern of the solid-state methyl acetate solvate Form B 3 product obtained in Example 11. Example 13 [0349] Pantoprazole sodium (0.50 g) was dissolved in methyl ethyl ketone (10 ml). After cooling to room temperature, the solution was filtered and left at the same temperature for 24 hours. The crystals obtained were separated by suction and dried at room temperature and atmospheric pressure for 20 hours to yield 0.43 g of Form C 1 crystals. [0350] Basic crystallographic data for the new solid-state methyl ethyl ketone solvate Form C 1 are represented in Table 5. [0351] The new solid-state methyl ethyl ketone solvate Form C 1 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.5±0.2°, 10.4±0.2°, 10.9±0.2°, 19.2±0.2°, 20.5±0.2°, 21.4±0.2°, 24.6±0.2°, 29.7±0.2°, 33.0±0.2°and 33.9±0.2°. Example 14 [0352] Pantoprazole sodium (5.0 g) was dissolved in methyl ethyl ketone (50 ml) and 2.5 ml of water was added. After cooling to room temperature, the solution was filtered and mixed for 5 hours at the same temperature. The obtained suspension was filtered, and the separated crystals were washed with methyl ethyl ketone and dried at room temperature and atmospheric pressure for 24 hours. Yield: 4.9 g of Form C 1 crystals. [0353] The x-ray powder pattern of the thus obtained sample corresponds to the x-ray powder pattern of the solid-state methyl ethyl ketone solvate Form C 1 product obtained in Example 13. Example 15 [0354] Pantoprazole sodium (5.0 g) was dissolved in methyl ethyl ketone (50 ml). After cooling to room temperature, solution was filtered and mixed for 5 hours at the same temperature. The obtained suspension was filtered. The separated crystals were washed with methyl ethyl ketone and dried at room temperature and atmospheric pressure for 6 hours. Yield: 4.7 g of Form C 2 crystals. [0355] The new solid-state methyl ethyl ketone solvate Form C 2 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.4±0.2°, 10.7±0.2°, 12.3±0.2°, 15.8±0.2°, 16.7±0.2°, 20.1±0.2° and 22.5±0.2°. Example 16 [0356] Pantoprazole sodium (0.5 g) was dissolved in diethyl ketone (15 ml). After cooling to room temperature the solution was filtered. The obtained solution was left at the same temperature for 24 hours. Thus obtained crystals were separated by suction and dried at room temperature and atmospheric pressure for 10 hours to yield 0.38 g of Form D 1 crystals. [0357] Basic crystallographic data for the new solid-state diethyl ketone solvate Form D 1 are represented in Table 6. [0358] The new solid-state diethyl ketone solvate Form D 1 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.2±0.2°, 10.4±0.2°, 12.3±0.2°, 13.1±0.2°, 15.1±0.2°, 15.8±0.2°, and 25.0±0.2°. Example 17 [0359] Crude pantoprazole sodium (5.0 g) was dissolved in diethyl ketone (50 ml). After cooling to room temperature, the solution was filtered and then stirred for 6 hours. The obtained suspension was filtered. The separated crystals were washed with diethyl ketone and dried at room temperature and atmospheric pressure for 8 hours. Yield: 2.8 g of Form D 1 crystals. [0360] The x-ray powder pattern of the thus obtained sample corresponds to the x-ray powder pattern of the new solid-state diethyl ketone solvate Form D 1 product obtained in Example 15. Example 18 [0361] 2.3 g of Form A 3 pantoprazole sodium aqua complex, prepared according to Example 6, was dried at 60° C. under a vacuum of 5 mbar for 3 hours to yield 2.0 g of Form E 1 . [0362] The desolvated Form E 1 has characteristic x-ray powder diffraction peaks designated by “2Θ” and expressed in degrees as follows: 5.4±0.2°, 11.6±0.2°, 12.4±0.2°, 13.6±0.2°, 16.0±0.2°, 23.3±0.2° and 28.7±0.2°. Example 19 [0363] 2.4 g of Form A 4 pantoprazole sodium aqua complex, prepared according to Example 7, was dried at 60° C. and under a vacuum of 10 mbar for 5 hours to yield 2.0 g of Form E 1 . [0364] The x-ray powder pattern of the thus obtained sample corresponds to the x-ray powder pattern of the new solid-state desolvated Form E 1 product obtained in Example 18. Example 20 [0365] 2.3 g of Form B 2 of pantoprazole sodium aqua complex, prepared according to Example 9 were dried at 80° C. and under vacuum of 5 mbar for 1 hour yielding 1.9 g of form E 1 . [0366] The x-ray powder pattern of the thus obtained sample corresponds to the x-ray powder pattern of the new solid-state desolvated Form E 1 product obtained in Example 18. Example 21 [0367] 2.8 g of Form B 3 of pantoprazole sodium aqua complex, prepared according to Example 11, was dried at 120° C. and under vacuum of 2 mbar for 2 hours yielding 2.4 g of Form E 1 . [0368] The x-ray powder pattern of the thus obtained sample corresponds to the x-ray powder pattern of the new solid-state desolvated Form E 1 product obtained in Example 18. Example 22 [0369] 2.8 g of Form B 3 pantoprazole sodium aqua complex, prepared according to Example 12, was dried at 60° C. and under vacuum of 5 mbar for 3 hours to yield 2.4 g of Form E 1 . [0370] The x-ray powder pattern of the thus obtained sample corresponded to the x-ray powder pattern of the new solid-state desolvated Form E 1 product obtained in Example 18. Example 23 [0371] 3.3 g of Form C 2 of pantoprazole sodium aqua complex, prepared according to Example 14, was dried at 50° C. and under vacuum of 5 mbar for 4 hours to yield 2.3 g of Form E 1 . [0372] The x-ray powder pattern of the thus obtained sample corresponded to the x-ray powder pattern of the new solid-state desolvated Form E 1 product obtained in Example 18. Example 24 [0373] 2.9 g of Form C 2 of pantoprazole sodium aqua complex, prepared according to Example 15, was dried at 25° C. and under vacuum of 1 mbar for 6 hours to yield 2.5 g of Form E 1 . [0374] The x-ray powder pattern of the thus obtained sample corresponded to the x-ray powder pattern of the new solid-state desolvated Form E 1 product obtained in Example 18. Example 25 [0375] 1.4 g of Form D 1 pantoprazole sodium aqua complex, prepared according to Example 16, was dried at 60° C. and under vacuum of 5 mbar for 5 hour to yield 1.2 g of Form E 1 . [0376] The x-ray powder pattern of the thus obtained sample corresponded to the x-ray powder pattern of the new solid-state desolvated Form E 1 obtained in Example 18.

The present disclosure relates to new solid-state forms of 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl]sulfinyl]-1H-benzimidazole sodium aqua complexes, and to processes for their preparation. The disclosure is also directed to pharmaceutical compositions containing the solid-state forms, and the methods of treatment using the solid-state forms.

The present application is a continuation under 37 C.F.R. § 1.53(b) of U.S. patent application Ser. No. 09/038,353, filed Mar. 10, 1998, now abandoned. FIELD OF THE INVENTION The present invention relates to the field of semiconductor memory, and more particularly to managing refresh and current control operations in a memory subsystem. BACKGROUND OF THE INVENTION The main operating memory of virtually all modern desktop and laptop computers is implemented using dynamic random access memory (DRAM) components. DRAM is relatively inexpensive and provides excellent storage density relative to other types of semiconductor memory. A defining characteristic of DRAM is that the individual storage cells in a DRAM component usually cannot hold their charge for more than about 70 milliseconds. Consequently, to prevent loss of data, each cell in the DRAM component is periodically sensed (read) and rewritten in a refresh operation. The fundamental aspects of DRAM refresh are the same for virtually every type of DRAM including Fast Page Mode (FPM) DRAM, Extended-DataOut (EDO) DRAM, Synchronous DRAM (SDRAM) and others. An activate operation is performed to enable the contents of a row of memory cells onto respective bitlines where they are sensed by an array of sense amplifiers. Because sensing the memory cells is destructive to the cells' contents, the outputs of the sense amplifer array are routed back to the respective bitlines to restore the appropriate charge levels to the memory cells. Thus, it is the activate operation that actually refreshes the contents of DRAM memory cells. After the activate operation is completed, a precharge operation is performed to close the sense amplifier array. In a precharge operation, memory cells in an activated row are decoupled from their respective bitlines and the sense amplifer array charges the bitlines to a voltage level that is approximately midway between the memory cell charge voltages for a “1” and a “0”. The memory cells and bitlines are now ready for subsequent activation. Because the sense amplifier array output is set to the precharge voltage to charge the bitlines, any data that had been captured in the sense amplifier array is lost in the precharge operation. For this reason, a precharge operation is said to “close” the bank associated with the sense amplifier array. After a sense amplifier array has been closed, it is ready for use in a subsequent activate operation. Because refresh operations consume DRAM bandwidth that could otherwise be used for data read and write transactions, it is desirable to reduce the time spent performing refresh operations. Unfortunately, core logic constraints and the limited command interface of most DRAM devices limits the extent to which refresh overhead can be reduced without sacrificing device operability. For example, in conventional DRAM devices there is often only one sense amplifier array. Because there is only one sense amplifier array, only one row of memory cells can be refreshed at a time and the total time to refresh all the rows in the device is simply the number of rows times the refresh time per row. In more modern devices, such as synchronous DRAM devices (SDRAM), two sense amplifier arrays are often included within a single component. The memory cells in the SDRAM are partitioned into banks with each bank being serviced by one of the two sense amplifier arrays. Using this arrangement it is possible to perform certain interleaved operations on the different banks. For reasons discussed below, however, it is usually not possible to perform interleaved refresh operations without sacrificing the ability to place the SDRAM in a reduced power state. SDRAM devices typically provide two modes for refresh. In one mode, called CBR refresh (Column Address Strobe Before Row Address Strobe), a CBR refresh command is issued to the SDRAM device to refresh a row and bank indicated by refresh logic within the SDRAM. The SDRAM's internal refresh logic typically includes a row counter that is incremented after each CBR refresh command to indicate the next row to be refreshed. When the SDRAM device enters a reduced power state, logic within the SDRAM continues to refresh the row indicated by the internal counter and to increment the row counter. As a result, no loss of continuity in the sequence of refreshed rows occurs when the device is transitioned between normal and reduced power states. A significant drawback to CBR refresh operation, however, is that both banks must typically be closed before a CBR refresh operation is initiated. Consequently, the potential for performing concurrent refresh operations in the respective SDRAM banks is usually not realized in CBR refresh mode and the total time to refresh a device is still the number of rows times the refresh time per row. Another mode of refreshing an SDRAM device is a controller-sequenced refresh mode. In the controller-sequenced refresh mode, the memory controller issues activate and deactivate (precharge) commands to each row in the SDRAM in a bank alternating sequence. Because an activate operation can be performed on a row in one bank while a deactivate is being performed on a row from another bank, the controller-sequenced refresh mode allows rows from respective banks to be concurrently refreshed, thus reducing the elapsed time required to refresh the entire SDRAM device. A significant disadvantage of the controller-sequenced mode is that it is usually difficult to place an SDRAM, operated in the controller-sequenced refresh mode, into a reduced power state without loss of data. So long as the SDRAM remains in normal (e.g., fully powered) operating state, the memory controller supplies the address of each row being refreshed and the memory controller is therefore aware, at any given time, which row is to be refreshed next. However, when the SDRAM is transitioned to a reduced power state, the SDRAM's internal row counter is used to supply the address of the row being refreshed and the row counter is periodically incremented so long as the SDRAM remains in the reduced power state. As a result, when the SDRAM is returned to the normal operating state, the address of the next row to be refreshed is typically unknown to the memory controller and a burst of refresh operations must therefore be issued to refresh each row in the SDRAM in whatever remaining time may be left in the refresh interval, tREF (tREF is the time interval within which each row in a DRAM device must be refreshed). In many SDRAM devices, it is not possible to refresh all of the rows in the SDRAM in such a remaining portion of the refresh interval so that the controller-sequenced refresh mode cannot be used with reduced power operation without the danger of some row failing to be refreshed within the proper interval. Thus, a designer using SDRAMs must usually make a choice: either use the slower CBR refresh mode so that reduced power operation can occur, or use the controller-sequenced refresh mode and disallow reduced power operation to prevent an improper refresh operation when transitioning between power states. In another multi-bank device called the Concurrent Rambus™ DRAM (Concurrent RDRAM®) developed by Rambus, Inc. of Mountain View, Calif., a command structure is provided that allows refresh commands directed to different banks to be interleaved. However, the underlying Concurrent RDRAM core logic does not permit concurrent activate and precharge operations to be performed on different banks. Consequently, though the refresh commands may be interleaved, concurrent refresh operations are not performed. SUMMARY OF THE INVENTION A method and apparatus for performing concurrent refresh operations in a memory device having a dynamic memory array with at least two banks, each bank including a plurality of rows of memory cells. The memory device receives an activate request identifying a bank in which a row is to be activated. The row to be activated is specified by a row register in the memory device. The memory device performs the activate operation on the row in the identified bank in response to the activate request. The memory device receives a precharge request that specifies the bank identified in the activate request, the precharge request being received concurrently with the activate operation on the row in the identified bank. The memory device performs the precharge operation on the identified bank in response to the precharge request. A method and apparatus for performing concurrent refresh and signal calibration operations in a DRAM component are also disclosed. Memory cells are refreshed within the DRAM component and a signaling circuit within the DRAM component is calibrated concurrently with refreshing the memory cells. These and other features and advantages of the invention will be apparent from the accompanying drawings and from the detailed description that follows below. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements and in which: FIG. 1 depicts a memory subsystem in which embodiments of the present invention may be used; FIG. 2 is a timing diagram that illustrates transmission of primitive row commands to effectuate a pipelined refresh command sequence according to one embodiment; FIG. 3 is a timing diagram that illustrates the elapsed time required to perform sixteen refresh operations according to one embodiment; FIG. 4 is a block diagram of a memory controller for issuing pipelined refresh command sequences according to one embodiment; FIG. 5 illustrates the arrangement of storage banks and sense amplifier arrays in an RDRAM device according to one embodiment; FIG. 6 is a flow diagram of memory controller sequencing logic according to one embodiment; FIG. 7 depicts a circuit that can be used to adjust the signaling strength of RSL signaling circuits in an RDRAM; FIG. 8 illustrates a number of the signal paths present on one embodiment of a channel; FIG. 9 is a diagram of a row command packet, RowR, according to one embodiment; FIG. 10 is a diagram of a column command packet, CoIX, according to one embodiment; and FIG. 11 is a timing diagram illustrating concurrent refresh and signal calibration operations according to one embodiment. DETAILED DESCRIPTION FIG. 1 depicts a memory subsystem 10 in which embodiments of the present invention may be used. The memory subsystem 10 includes three primary components: a memory controller 12 , a Rambus Channel 16 and one or more Rambus DRAMs 18 , 20 (RDRAMs). The Rambus Channel 16 and RDRAM devices 18 , 20 are named for their developer, Rambus, Inc. of Mountain View, Calif. Rambus and RDRAM are trademarks of Rambus, Inc. The memory subsystem 10 is intended to be a general purpose high performance memory and may be used in a broad range of applications. For example, the memory subsystem 10 may be used as a main memory or graphics memory in a computer system. The memory subsystem 10 may also be used as a memory in consumer electronics devices such as personal digital assistants or digital cameras, or in any other application where high performance data storage is required. The memory controller 12 manages the operation of the RDRAM devices 18 , 20 on the Rambus Channel 16 by transmitting various packetized commands on a command portion of the Rambus Channel 16 . As discussed below, these packetized commands include read and write commands that require data to be transported to and from the RDRAM devices via a data portion of the Rambus Channel 16 . The packetized commands also include commands for performing overhead operations such as refresh operations and signal calibration operations. Overhead operations usually render an RDRAM 18 , 20 at least partially unavailable for read/write access and therefore reduce the overall bandwidth of the memory subsystem 10 . Also, transfer of commands for performing overhead operations on the Rambus Channel 16 consumes channel bandwidth that could otherwise be used for transfer of read/write commands. Consequently, it is an intended advantage of the present invention to reduce the impact of overhead operations and associated commands on device and channel availability by concurrently transmitting overhead commands and by concurrently executing overhead operations. It is another intended advantage of the present invention to reduce the impact of overhead operations without constraining the use of other operational features of the RDRAM devices 18 , 20 such as power saving features. According to one embodiment, the Rambus Channel 16 (hereinafter “the channel”) is coupled at one end to a Rambus ASIC Cell 14 in the memory controller 12 (ASIC is an acronym for application-specific integrated circuit) and at the other end to a voltage Vterm through pull-up resistors Rterm 21 . Each of the RDRAM devices 18 , 20 is coupled to the channel 16 between the channel's ends. Transfer of data and commands on the channel 16 is accomplished using specialized signaling circuitry called “Rambus Signaling Logic” (RSL). RSL permits extremely high data transfer rates, with bits being present on the channel 16 in some cases for less than two nanoseconds. RSL signaling circuits within RDRAM devices 18 , 20 and the Rambus ASIC Cell 14 transmit binary data on the channel 16 by enabling or disabling current flow in respective signal paths. In one embodiment, a logical “1” is transmitted on the channel 16 by causing the signaling circuit to sink a controlled current, I OL , thus pulling the voltage of the signal path down to Von=Vterm−(I OL *Rterm). The signal swing between Von and Vterm is relatively small (e.g., 0.8 volts in one embodiment), making it possible to clock the signal paths on the channel 16 at frequencies upwards of 400 MHz. To avoid problems with clock skew, clock signals are transmitted on the channel 16 along with commands and data. Because RSL signaling circuits produce relatively low voltage swings, a relatively small misadjustment in the on-current, I OL , sunk by a RSL signaling circuit can result in lost or misinterpreted signals. It is important, therefore, that the on-current (I OL ) of a RSL signaling circuit be kept relatively constant across variations temperature and voltage. Consequently, in memory subsystems that include RDRAM devices it is usually necessary to periodically adjust the RSL signaling circuits to avoid drift in I OL due to changes in temperature and voltage. Methods for minimizing the reduction in RDRAM and channel availability due to these periodic signal calibration operations are discussed below. Each RDRAM 18 , 20 shown in FIG. 1 includes a plurality of storage banks 33 , a command interface 25 , Rambus Signaling Logic 31 (RSL), control logic 27 and an internal row refresh register 29 REFR and an internal bank refresh register 30 (REFB). Each RDRAM 18 , 20 may also include other components not shown in FIG. 1, including sense amplifier arrays and data steering logic. According to one embodiment, the command interface 25 within an RDRAM 18 , 20 is used to receive and decode command packets from the memory controller 12 and to issue the appropriate signals to the control logic 27 in response. The control logic manages read and write access to the storage banks as well as overhead operations such as refresh and signal calibration operations. The control logic 27 also manages the transitioning of the RDRAM 18 , 20 between one or more power consumption states. The row refresh register 29 REFR, which may alternately be considered part of the control logic 27 , is used to address a row within the RDRAM 18 , 20 that is to be refreshed during a refresh operation. According to one embodiment, refresh operations are initiated in response to either an internal state (e.g., automatic refresh during a power saving mode) or refresh commands received from the memory controller 12 . As discussed above, it is necessary to refresh each row in an RDRAM 18 , 20 once per refresh interval (tREF). According to one embodiment, the refresh register 29 REFR is used to supply the address of an RDRAM row to be refreshed regardless of whether the stimulus for the refresh operation is an internal state (e.g., auto-refresh) or a command from the memory controller 12 . With this design, the proper sequencing of refresh operations through the rows of the RDRAM 18 , 20 is maintained despite the transition of the RDRAM 18 , 20 into and out of a power saving mode in which auto-refresh is performed. This is a significant advantage over the above-described prior art techniques. The Rambus Signaling Logic 31 (RSL) includes signaling circuits for driving state information onto a data portion of the channel 16 . As discussed above, the voltage swings for these signals are relatively small and it is important that each of the signaling circuits be conditioned to enable an accurate, relatively constant drive current on the channel even through changes in temperature and voltage. In one embodiment, a biasing signal to the signaling circuits is adjusted in periodic signal calibration operations to increase or decrease the on-current, I OL , sunk by RSL signaling circuits. While techniques for reducing the overhead associated with adjustment to current sinking circuits are described herein, the techniques may be applied to reduce the overhead associated with other types of adjustment operations in the RDRAM or memory controller 12 without departing from the spirit and scope of the present invention. Reducing Refresh Overhead Through Concurrency in Refresh Commands and Refresh Operations According to one embodiment, the overhead associated with performing refresh operations in an RDRAM 18 , 20 is reduced by performing refresh operations on respective banks of the RDRAM 18 , 20 concurrently with one another. In one implementation this is achieved by combining a command interface 21 that supports receipt of pipelined refresh command sequences with an RDRAM core that includes logic for performing row operations (i.e., precharge and activate operations) on respective storage banks independently of one another. More specifically, by providing a plurality of row decoding circuits in the RDRAM device to allow word lines in respective banks to be asserted and deasserted independently of one another and also by providing logic to control the precharge voltages output by respective sense amplifier arrays independently of one another, it becomes possible to respond to the pipelined refresh commands by concurrently refreshing rows of memory cells in respective banks of an RDRAM 18 , 20 . FIG. 2 is a timing diagram that illustrates transmission of primitive row commands on a channel to effectuate a pipelined refresh command sequence. In one implementation, a refresh command sequence is composed of three primitive row commands each of which include a bank address to indicate the bank to be operated on. The primitive commands are PRER, a command to precharge the indicated bank; REFA, a command to activate a row in the indicated bank, the row being indicated by the RDRAM's internal refresh register (e.g., element 29 of FIG. 1 ); and REFP, a precharge-post-refresh command to precharge the addressed bank and, if the addressed bank is a predetermined bank number (e.g., the highest numbered bank in the RDRAM), to increment the row address in the RDRAM's internal refresh register. Starting at clock cycle zero in FIG. 2, a memory controller initially issues a PRER command 41 to precharge a bank within an RDRAM. The precharge operation requires a time, tRP, to complete (eight clock cycles in this example). Time tRP after issuing the PRER command 41 , the memory controller issues a REFA command 43 to activate a row within the RDRAM. As mentioned above, in one embodiment, the address of the bank to be refreshed is supplied in the REFA command 43 and the address of the row within the addressed bank is obtained from a row refresh register REFR in the RDRAM. The row activation operation requires a time, TRAS, which is relatively long (24 clock cycles in this example) because it involves sensing the relatively low level signals on the bitlines of the addressed bank. After a time tRAS has elapsed, the memory cells in the selected row have been refreshed and a precharge operation may be performed to close the bank. Thus, time tRAS after issuing the REFA command 43 , memory controller issues a REFP command 45 to perform the precharge operation. When the precharge operation is completed tRP after receipt of the REFP command, the refresh operation is completed. As described above, if the bank address included in the REFP command 45 matches a predetermined address, the row address in the RDRAM row refresh register REFR is incremented. Because the RDRAM includes logic for performing concurrent row operations in different banks and because the RDRAM command interface permits receipt of primitive row commands concurrently with performing a refresh operation in a first bank, a second refresh operation may be commanded and executed in a second bank concurrently with executing a previously commanded refresh operation in a first bank. Still referring to FIG. 2, a second PRER command 47 is transmitted on the channel just after the REFA command 43 . By formatting the second PRER command 47 to address a different bank than the bank addressed in the three primitive commands that constitute the first refresh command sequence (i.e., commands 41 , 43 , 45 ), a new refresh command sequence is begun. A time tRP after issuing the second PRER command 47 , a second REFA command 49 is issued to activate a row in the indicated bank. As shown in FIG. 2, the first and second refresh command sequences are issued concurrently and the resulting first and second refresh operations are performed concurrently. Because the PRER and REFA commands 47 , 49 of the second refresh command sequence are transmitted during the interval between the REFA and REFP commands 43 , 45 of the first refresh command sequence, there is no conflicting demand for channel access and therefore no additional delay incurred as a result of the command sequence transmissions. A time tRAS after the REFA command 49 is issued, a second REFP command 51 is issued to complete the second refresh operation. Still referring to FIG. 2, it is not always necessary for the memory controller to issue a PRER command 41 , 47 to start a refresh command sequence. As discussed above, the purpose of the PRER command is to close the indicated bank so that the bank is ready for the ensuing activate operation. In one embodiment, the memory controller tracks the state of each bank in the RDRAM device based on the sequence of commands that the memory controller issues. If the memory controller determines that the bank to be refreshed by a refresh command sequence (i.e., PRER, REFA, REFP) is already closed, the PRER command can be dropped, thus saving the tRP delay time and avoiding unnecessary channel utilization. Also, the RDRAM may be configured to automatically precharge a bank upon completion of a read/write operation on that bank. This is typically referred to as an auto-precharge mode. The memory controller may determine that an RDRAM or a bank within an RDRAM is configured for auto-precharge mode and therefore drop the PRER command from the refresh command sequence. FIG. 3 is a timing diagram that illustrates the reduction in elapsed time required to perform sixteen refresh operations according to one embodiment. In FIG. 3, it is assumed that the memory controller implements a closed page policy (i.e., an open bank is closed after each read/write transaction) so that the initial precharge command (PRER) can be dropped from each refresh command sequence. The first of 16 concurrently performed refresh operations is begun when an activate command ACT 1 (e.g., a REFA command) is transmitted. As shown, a time tPACKET is required to transmit this command across the channel. In one embodiment, the command is transmitted during 4 cycles of a 400 MHz clock so that the command is transferred on the channel over a 10 nS interval. Shortly after the activate command is received in the RDRAM device, an activate operation is performed in the RDRAM core. The time interval over which this activate operation is performed is shown in FIG. 3 as tRASmin 1 . A typical activate operation requires approximately 60 nS. After the activate command ACT 1 has been transmitted, a delay of approximately tPACKET occurs and then a second activate command ACT 2 is transmitted on the channel. In response to activate command ACT 2 , a second row activate operation is performed in the RDRAM core concurrently with the first activate operation, but on a different bank. This second activate operation occurs over the time interval tRASmin 2 . Activate commands ACT 3 and ACT 4 are likewise sent to initiate third and fourth activate operations on respective banks of the RDRAM as indicated by time intervals tRASmin 3 and tRASmin 4 . Just after the ACT 4 command is issued and before a subsequent activate command ACT 5 is issued, a precharge post-refresh command PCH 1 (e.g., a REFP command) is transmitted on the channel. PCH 1 is directed to the same bank as the ACT 1 command and initiates a precharge operation to complete the refresh operation on that bank. A precharge operation typically requires approximately 20 nS as shown by time tRP 1 in FIG. 3 . After the PCH 1 command is issued, activate commands ACT 5 , ACT 6 , . . . ACT 16 and precharge commands PCH 2 , PCH 3 , . . . PCH 13 are interleaved so that either an activate or a precharge command is being transmitted on the channel until during each cycle of channel availability until after PCH 13 is issued. As a result, each of the refresh command sequences is pipelined on the channel and each refresh operation is performed concurrently with at least one other refresh operation. After PCH 13 , the final precharge commands PCH 14 , PCH 15 and PCH 16 are issued to complete the fourteenth, fifteenth and sixteenth refresh operations, respectively. According to one embodiment, sixteen banks are provided in an RDRAM so that by issuing sixteen pipelined refresh command sequences as shown in FIG. 3, one row in each bank of the device is refreshed. By using the RDRAM's internal row refresh register REFR to indicate the row to be refreshed and by incrementing the internal row refresh register REFR in response to the final precharge post-refresh command PCH 16 , individual bursts of sixteen concurrent refresh operations can be used to update the RDRAM device on a row by row basis. As discussed above, by using the same internal row refresh register REFR to specify the address of the row to be refreshed whether in normal operating mode or in a reduced power mode, progression through the sequence of rows is maintained in proper order even through transitions into and out of a reduce power mode. As mentioned above, in at least one embodiment, the memory controller provides the address of the bank to be refreshed in the primitive row commands that make up a refresh command sequence. When a reduced power mode is entered, logic within the RDRAM device is used to increment the bank register REFB (e.g., element 30 of FIG. 1) that points to the bank to be refreshed after each internally initiated refresh operation. Because the memory controller may not be aware which bank was the last to be refreshed in a sequence, it may be necessary for the memory controller to repeat the refreshing of one or more banks by a burst of up to B bank refreshes, where B is the number of banks, when the RDRAM is transitioned from a power saving mode to a refresh mode. In an alternative embodiment of the present invention, the last bank to be refreshed may be read by the memory controller to determine the next bank to be refreshed. Still referring to FIG. 3, another aspect of pipelining the refresh command sequences is that efficient use of channel bandwidth is achieved. Also, because of the concurrent refreshing of the different banks of the RDRAM, the tRASmin and tRP time intervals of the refresh operations are effectively hidden by one another. For example, if the refresh operation for each row in each bank was performed serially, the elapsed time to completely refresh the RDRAM would be approximately B*R*(tRASmin+tRP), where B is the number of banks in the device and R is the number of rows per bank. By issuing pipelined command sequences to effectuate the sixteen concurrent refresh operations illustrated in FIG. 3, however, the elapsed time to completely refresh the RDRAM would be approximately (B*R)*(6*tRASmin+tRP+tPACKET)/16. It will be appreciated that the number of pipelined refreshes of a given refresh pipeline may be configured based on system design parameters. At one extreme, a burst of refresh command sequences may be issued without interruption to refresh each row in each bank of the RDRAM device. While this would reduce the time spent performing refresh operations as a proportion of device operating time, an increased read or write access latency would be incurred waiting for the long sequence of refresh operations to be completed. At the other extreme, only a small number of refresh command sequences (e.g., two) might be pipelined to reduce the read or write access latency, but with a less significant reduction in refresh overhead time. Any operation between these two extremes is considered to be within the scope of the present invention and a memory controller architecture that permits a variable number of pipelined refreshes is described below. Simplifying RDRAM Control Logic Through the Use of Primitive Row Commands in the Refresh Command Sequence A significant advantage of using multiple primitive commands to effectuate a refresh operation in an RDRAM is that control logic within the RDRAM device can be simplified. One reason for this is that the timing of the constituent precharge, activate and precharge post refresh operations can be enforced by the memory controller instead of logic within the RDRAM device. That is, instead of issuing a single refresh command to an RDRAM device and requiring logic in the RDRAM device to time the primitive operations of precharge, activation and precharge post refresh (i.e., logic to enforce the tRP and tRASmin delays), the RDRAM can be configured to simply perform the precharge, activation and precharge post refresh operations when the corresponding commands are received. The timing of the primitive operations within the RDRAM is then determined by when the memory controller issues the PRER, REFA and REFP commands. That is, the memory controller may be configured to issue the PRER command, issue the REFA command tRP later than the PRER command, and then issue the REFP command tRASmin later than the REFA command. Requiring the memory controller to time issuance of these commands is not particularly onerous because the memory controller will usually need to time the overall refresh operation anyway so that it will know when the refresh operation has been completed. Moreover, the savings obtained by removing refresh timing logic from the RDRAM device is multiplied by the potentially large number of RDRAM devices in a memory subsystem. This is a significant advantage achieved by decomposing a unitary refresh command into primitive commands that correspond to the elementary operations used to refresh a row of memory cells. Over view Of A Memory Controller According to One Embodiment FIG. 4 is a block diagram of a memory controller 156 for issuing pipelined refresh command sequences according to one embodiment. The memory controller 156 includes a configuration storage 157 , arbitration logic 165 , read/write request logic 163 , refresh logic 159 , calibration logic 161 and a channel command sequencer 167 . In one embodiment, the refresh logic 159 includes a refresh timer 160 and the calibration logic 161 includes a calibration timer 162 . In one implementation, memory configuration parameters are written to the configuration storage 157 during system initialization. The configuration parameters include, the number of RDRAM devices in the memory subsystem, the number of storage banks per RDRAM, the number of rows of memory cells per bank, the time interval within which each row of an RDRAM must be refreshed (tREF) and the interval within which each RSL signaling circuit must be calibrated (tCCTRL). The configuration storage 157 may also be programmed with policy control parameters that are used to prioritize requests received in the channel command sequencer 167 and in the arbitration logic 165 . In one embodiment, the arbitration logic 165 receives requests to issue commands to RDRAM devices from the read/write request logic 163 , the refresh logic 159 and the calibration logic 161 . The arbitration logic 165 selects from among these competing requests based on the policy control parameters received from the configuration storage 157 and forwards a prioritized stream of transaction requests to the channel command sequencer 167 . In one embodiment the channel command sequencer 167 is a state machine that generates and outputs command packets on the channel according to the stream of transaction requests from the arbitration logic and based on policy control parameters received from the configuration storage 157 . As discussed below, in one implementation the channel includes separate command ports for issuing different types of command packets. In one embodiment, the channel command sequencer 167 may reorder the transaction requests received from the arbitration logic 165 to increase the concurrency of command packets sent on the two command ports. In one implementation the refresh logic 159 issues a request to perform a multi-bank refresh each time the refresh timer 160 expires. Each multi-bank refresh request causes the channel command sequencer 167 to issue a pipelined set of N refresh command sequences, with each command sequence being broadcast to each RDRAM on the channel. The value N may be hard wired or it may be determined based on a parameter supplied to the refresh logic from the configuration storage. In one embodiment, for example, the parameter is equal to the number of banks per RDRAM so that each refresh request causes the channel command sequencer 167 to issue a pipelined set of refresh command sequences directed to each of the respective banks of each RDRAM. For example, in a sixteen bank device, a pipelined set of sixteen refresh command sequences as shown in FIG. 3 is issued when the refresh timer 160 times out. The refresh timer 160 is programmed to have a timeout interval equal to (tREF * N)/(number of banks * number of rows) so that each row in each RDRAM device is refreshed within the tREF interval. The calibration logic 161 issues a calibration request in response to timeout of the calibration timer. As discussed below, the RDRAM devices are calibrated independently of one another so that the calibration timer 162 is programmed to timeout after every time interval tCCTL/number of RDRAM devices. As discussed below, each calibration request typically results in multiple commands being issued by the channel command sequencer 167 . In one embodiment, the channel command sequencer may abort issuance of a sequence of calibration-related commands in response to a higher priority read or write request. This design reduces the read/write access latency caused by signal calibration operations. Performing Concurrent Refresh Operations In An RDRAM That Includes Dependent Banks FIG. 5 illustrates the arrangement of N storage banks 33 a , 33 b , 33 c , 33 d and N+1 sense amplifier arrays 34 a , 34 b , 34 c , 34 d in an RDRAM device 18 according to one embodiment. Using a design technique referred to as “bank doubling”, each of the N storage banks 33 a , 33 b , 33 c , 33 d shares at least one of the sense amplifier arrays 34 a , 34 b , 34 c , 34 d with another bank. The idea behind bank-doubling is to reduce the number of die-consuming sense amplifiers in the DRAM device to provide room for more storage banks. By halving the number of sense amplifiers in each sense amplifier array 34 a , 34 b , 34 c , 34 d and then coupling two such half-sized sense amplifiers arrays 34 a , 34 b , 34 c , 34 d to each storage bank 33 a , 33 b , 33 c , 33 d , it becomes possible to sense data in N storage banks using N+1 half-sized sense amplifier arrays. (This represents a nearly 2:1 increase in the ratio of storage banks to sense amplifiers—hence the expression, bank doubling.) Referring to bank 1 ( 33 b ) for example, when a row is activated in bank 1 ( 33 b ), sense amplifer array 0 / 1 ( 34 b ) and sense amplifer array 1 / 2 ( 34 c ) each sense the data from a respective half of the activated row so that, in combination, the half-sized sense amplifier arrays 0 / 1 and 1 / 2 ( 34 b , 34 c ) provide a full sense amplifier array for the activated row in bank 1 ( 33 b ). In one embodiment, banks at extreme die positions relative to other banks (e.g., bank zero 33 a and bank N−1 33 d in FIG. 5) each have one dedicated half-sized sense amplifier array (sense amplifier arrays zero 34 a and N 34 d , respectively). One consequence of the bank doubling design is that the availability of a given bank is dependent upon whether the bank's sense amplifier arrays are in use by another bank. Two banks which share a sense amplifier array are therefore said to be dependent banks and may not be open at the same time. From the viewpoint of RDRAM refresh operations, this means that concurrent refresh operations should be prevented from being initiated in dependent banks. In one embodiment this is accomplished by configuring the memory controller to address banks for concurrent refresh according to a bank selection sequence that prevents row operations from being concurrently performed on dependent banks. For example, in a device that contains 16 banks (numbered 1 - 16 ), the memory controller may be configured to increment the address of the bank selected for each successive refresh operation as follows: Next Bank=(Present Bank+5) modulo 16. This results in the following bank selection sequences: 1 , 6 , 11 , 16 , 5 , 10 , 15 , 4 , 9 , 14 , 3 , 8 , 13 , 2 , 7 , 12 , 1 , 6 , and so forth. In the embodiment of FIG. 5, this means that, after beginning refresh of a given bank, at least two non-dependent banks will be refreshed before a dependent bank is refreshed. It will be appreciated that other bank selection sequences may be used without departing from the spirit and scope of the present invention. FIG. 6 is a flow diagram of memory controller logic according to an embodiment that supports issuance of overlapping refresh command sequences even if the target RDRAM device includes dependent banks. Initially, in block 71 , a timer (e.g., element 160 of FIG. 4) within the memory controller times out to indicate that it is time to perform a refresh operation. At block 73 the address of the next bank to be refreshed, bank i , is generated. In one embodiment, the bank address is calculated by adding or subtracting a value from the previously calculated address using modulo arithmetic. In an alternate embodiment, the bank address may be obtained from a bank address lookup table in which a bank selection sequence has been stored, for example, during system initialization after a start-up procedure has determined the configuration of the RDRAM components in the memory subsystem. At decision block 75 the memory controller determines whether bank i is open and, if so, the memory controller issues a precharge command (e.g., PRER) to close bank i at block 77 . If bank i is not open, then block 77 is skipped and an activate command (e.g., REFA) is issued at block 79 . As discussed above, in one embodiment the activate command includes a bank address, but not a row address. Instead the row address is obtained from the row refresh register REFR within the RDRAM device being refreshed. Note that if bank i had been open, then after issuing the precharge command at block 77 the memory controller delays for a time tRP before issuing the activate command at block 79 . After issuing the refresh command at block 79 , the memory controller delays for a time tRASmin before issuing a precharge post refresh command (e.g., REFP) at block 81 . As mentioned above, the precharge post refresh command is similar to the precharge command except that it causes the row address within the RDRAM's internal row refresh register REFR to be incremented when the bank address is a predetermined value. Still referring to FIG. 6, a second refresh command sequence is issued by the memory controller concurrently with the first refresh command sequence. Beginning at block 83 , a new bank address, bank j , is generated. In one embodiment, the memory controller specifically selects bank j (either through calculation or table look-up) because it is not dependent on bank i . At block 85 , the memory controller determines whether bank j is open and, if so, issues a precharge command to close the bank at step 87 . At block 89 , an activate command is issued to bank j . As indicated by arrow 80 in FIG. 6, because the precharge and activate commands addressed to bank j are issued after the activate command addressed to bank i and before issuance of the precharge post refresh command addressed to bank i , the precharge and sense commands addressed to bank j are transmitted on the channel concurrently with the activation of bank i . As discussed above, because the command interface of the RDRAM device is designed to receive commands directed to one bank concurrently with an ongoing refresh operation in another bank, and because the RDRAM includes logic to allow concurrent row operations to be performed on respective banks, refresh operations can be concurrently performed on respective banks. Calibration of Rambus Signaling Logic FIG. 7 depicts a circuit 108 that can be used to adjust the signaling strength of RSL signaling circuits in an RDRAM device 18 . The circuit 108 consists of a pair of resistors 100 a , 100 b coupled via switches 120 and 121 to form a voltage divider between the outputs Dx, Dy of two RSL signaling circuits 111 , 112 . Switches 120 , 121 are used so that the resistors 100 a and 100 b can be disconnected connected from the RSL signaling circuits 111 and 112 during normal operation. The midpoint of the voltage divider, Vsamp 103 , is coupled to one input of a comparator 119 and the other input of the comparator 119 is coupled to the reference voltage, Vref 109 . In one embodiment, Vref 109 is supplied to the RDRAM device 18 from an external source and Von (discussed above) is set so that the output signal on either Dx or Dy swings symmetrically about Vref 109 . In an alternate embodiment, Vref 109 may be generated within the RDRAM device 18 . In yet another embodiment, Von may be set so that the output signal does not swing symmetrically about Vref. Still referring to FIG. 7, the comparator 119 output Vcomp 105 is coupled to latch circuitry 125 whose output is coupled to an up/down input of a counter 114 . The counter 114 samples its up/down input in response to a sample signal 135 and increments or decrements an internally stored count value accordingly. In one embodiment, the count value is output as an N-bit biasing signal 115 that is supplied to each of the RSL signal driving circuits on the RDRAM device. In one implementation, the respective bits of the biasing signal 115 (i.e., bits C 0 , C 1 , C 2 , C N−1 ) are gated by a data signal 101 at gates 125 a , 125 b , 125 c , 125 d and then applied to the respective control inputs of a set of transistors 127 a , 127 b , 127 c , 127 d . Each of the transistors 127 a , 127 b , 127 c , 127 d is weighted to sink approximately twice as much current as a less significant one of the transistors 127 a , 127 b , 127 c , 127 d . Using the count value to bias the transistor bank of an RSL signaling circuit in this way, up to 2 N −1 different values of on-current (I OL ) may be obtained in approximately equal steps. As the count value in the counter 114 is adjusted up or down, the impedance of the RSL signaling circuit 112 , is adjusted to enable a lower or higher on-current to flow on the signal path of the channel. In one embodiment, the biasing signal 115 output from the counter 114 is applied to each signal driving circuit on the RDRAM 18 so that all RSL signaling circuits are adjusted at the same time and by the same amount. In alternate embodiments, multiple counters may be used to allow adjustment of smaller groups of RSL signaling circuits or even to allow individual adjustment of each RSL signaling circuit. According to one embodiment, the biasing signal 115 (i.e., the count value) used to control the on-current of an RSL signaling circuit is adjusted by first turning off the signaling circuit 111 and turning on the signaling circuit 112 . Also, switches 120 and 121 are turned on to couple the voltage dividing resistors 100 a , 100 b across the two signaling circuits 111 and 112 . This causes current to flow from Vterm through resistor Rterm 21 a on the Dx signal path, through the voltage dividing resistors 100 a , 100 b and finally through the signaling circuit 112 . In one embodiment, the goal of a current calibration operation is to adjust the impedance presented by the signaling circuit 112 to the point at which the voltage Vsamp 103 is approximately equal to Vref 109 . Assuming for example that Vsamp 103 is initially above Vref 109 , the comparator will output a high Vcomp which, when the output of the comparator is latched in latch 125 by deassertion of the CCEVAL signal 130 and assertion of the SAMPLE signal 135 , will cause the counter 114 to increment its count value. The increased count value will be transmitted to the signaling circuit 112 via the biasing signal 115 . The increased biasing signal 115 will reduce the impedance of the signaling circuit 112 and thereby increase I OL . The reduced impedance of the signaling circuit 112 will also cause Vsamp 103 to be reduced. If Vsamp 103 drops below Vref 109 , the comparator 119 will output a low-valued Vcomp 105 . The low Vcomp 105 will cause the counter 114 to decrement the count value when the output of the comparator is latched in latch 125 by the deassertion of the CCEVAL signal 130 and assertion of the SAMPLE signal 135 . Decrementing the counter 114 will reduce the biasing signal 115 and therefore increase the impedance presented by signaling circuit 112 so that I OL is decreased and Vsamp 103 is increased. When calibrating RSL signaling circuits it is usually necessary to block other transactions on the Rambus Channel to prevent interference with calibration signals on the Dx and Dy signal paths. Although the time required to perform a signal calibration operation is usually short (e.g., a few dozen nanoseconds or less) it must still be accounted for in determining a worst case read or write latency. According to one embodiment, the impact on read/write latency caused by signal calibration operations is reduced by resolving the single calibrate-and-sample command that had been used in prior systems into two more primitive types of commands. A first command type, called a calibrate command, is issued to the RDRAM device 18 to cause the device to begin a current adjustment operation by engaging switches 120 , 121 , turning off the signaling circuit 111 and turning on the signaling circuit 112 , as described above. This is referred to as enabling the calibration circuitry and is associated with the on-state of the signal CCEVAL 130 . While the RDRAM device continues to receive calibrate commands from the memory controller, the calibration circuitry remains enabled and the calibration circuitry is disabled when a non-calibrate command is received. When the calibration circuitry is disabled, the states of the signaling circuits 111 , 112 are no longer forced so that normal data transport operations can take place on the channel. In effect, calibrate commands act as keep alive signals to maintain the calibration circuitry in the enabled condition. So long as calibrate commands continue to be received in the RDRAM device 18 , the calibration circuitry remains enabled. In one embodiment, after approximately three calibrate commands have been issued to enable the calibration circuitry and to allow the output Vcomp 105 of the comparator 119 to become stable, the memory controller issues a second type of primitive command called a calibrate/sample command. The calibrate/sample command causes two phases of operation to occur in the circuit 108 : a calibrate phase during which assertion of the CCEVAL signal 130 is maintained, and a sample phase during which the CCEVAL signal 130 is deasserted to latch the state of Vcomp 105 in latch 125 and the SAMPLE signal 135 is asserted to adjust the count value in counter 114 up or down based on the latched state of Vcomp output by latch 125 . According to one embodiment, a memory controller is configured at system initialization time to issue a predetermined number of calibrate commands in each signal calibration operation before issuing a sample command. The predetermined number of calibrate commands may be empirically determined based on, for example, the time required for I OL to settle and the time required for the comparator 119 to output a steady Vcomp 105 after I OL has settled. In one embodiment, after the predetermined number of calibrate commands have been issued, the memory controller issues the calibrate/sample command to disable the calibration signal and to assert the SAMPLE signal 135 so that the count value is incremented or decremented based on Vcomp 105 . After the sample command has been issued and the count value has been adjusted the calibration operation is completed. Because temperature change and steady-state voltage drift (e.g., drift in Vterm) are relatively slow phenomena, performing a calibration operation once every hundred milliseconds or so in each RDRAM device is usually sufficient to track any environmental changes. It will be appreciated that at system initialization, it may be necessary to issue several calibrate-calibrate/sample command sequences in succession to make a relatively large initial adjustment to the signaling circuit drive strength. As mentioned above, in prior RDRAM devices a single command was issued by the memory controller to perform a calibration operation. One advantage of resolving the single command into the more primitive calibration command types (i.e., calibrate commands and calibrate/sample commands), is that it becomes possible to interrupt a calibration operation during the sequence of calibrate commands to perform a higher priority operation such as a read or write. This reduces the worst case read/write latency because a requested read or write need not be delayed while a calibration operation is completed. For example, if a request to perform a high priority read operation is received after a calibrate command has been issued, the memory controller may issue the read request instead of continuing with the calibrate and calibrate/sample command sequence. As discussed below, the read request is issued on a dedicated command path and therefore may be issued directly after a calibrate command without any adverse effects. The calibration circuitry simply disables itself and no adjustment to the value in the up/down counter 114 is made. The RSL signaling circuits are then available to drive the data retrieved in response to the read command onto the data portion of the channel. Also, because no sample command is issued (it has been superseded by the read command), the biasing signal 115 remains unchanged. Thus, by resolving a single signal adjustment command into different primitive command types, a signal calibration operation may be interrupted to service higher priority requests without compromising the calibration setting of the RSL signaling circuits. RSL signaling circuits are also included in the Rambus ASIC Cell (e.g., FIG. 1, element 14 ) in memory controller. These RSL signaling circuits can be calibrated using the circuit shown in FIG. 7 . According to one embodiment, the signal paths across which the voltage dividing resistors (e.g., elements 100 a , 100 b of FIG. 7) are coupled are different for the Rambus ASIC Cell than for the RDRAM devices so that the RSL signaling circuits in the Rambus ASIC Cell may be calibrated concurrently with calibration of RSL signaling circuits in a RDRAM device without conflict. Increasing Channel And RDRAM Availability By Performing Concurrent Refresh And Signal Calibration Operations According to one embodiment, channel and RDRAM availability are increased by concurrently commanding and performing refresh and calibration operations. One way that this is accomplished is by providing distinct command ports on the channel to allow the primitive row commands used to perform refresh operations to be received on one command port at the same time that primitive calibration commands are received on another command port. FIG. 8 illustrates a number of the signal paths present on one embodiment of a channel. The DQA 0 -DQA 8 signals and the DQB 0 -DQB 8 signals are used to transfer data to and from the RDRAM devices coupled to the channel and are driven in the outgoing direction by the RSL signaling circuits described above. In one embodiment, the Row 0 -Row 2 and the Co 10 -Co 14 signal paths are used to carry command packets from the memory controller to the RDRAM devices. The CTM and CFM are the clock-to-master and clock-from-master signals, respectively, and are used to provide the bus cycle timing for transfer of command packets and data packets on the channel. According to one embodiment, the Row 0 -Row 2 and Co 10 -Co 14 signal paths are used to provide respective row and column command ports on the channel. A first category of command packets, called row command packets, are transmitted on the row command port and a second category of command packets, called column command packets, are transmitted on the column command port. As mentioned above, providing two discrete command ports makes it possible to issue refresh related commands on one command port concurrently with issuing calibration related commands on the other command port. Because refresh operations do not result in transfer of data via RSL signaling circuits in the RDRAM, and because current calibration operations do not require access to storage banks within the RDRAM, these operations may be performed concurrently to reduce the RDRAM unavailability due to refresh and current calibration. In effect, the time required to perform current calibration operations may be hidden in the refresh operations. FIG. 9 is a diagram of a row command packet, RowR, according to one embodiment. The RowR packet is used to issue various commands including the primitive row commands PRER, REFA and REFP used to perform refresh operations. As shown in FIG. 9, the packet is transmitted on the Row 0 -Row 2 signal paths of the channel, with a respective group of three bits being transferred in response to each of eight successive transitions of a clock signal (e.g., clock from master, CFM). Thus, the RowR packet includes twenty-four bits in all. According to one embodiment, the DR 4 T and DR 4 F bits of the RowR packet are used to indicate whether the command packet is being broadcast to all RDRAM devices on the Rambus channel (32, with five bits specifying the device), or only to those devices whose low order device ID bits match bits DR 0 -DR 3 of the RowR packet (further decoding of the DR 4 T and DR 4 F fields are used to provide an additional device ID bit). This permits row commands, including the primitive commands for performing refresh operations to be broadcast to all of the RDRAM devices on the channel at once or, alternatively, to a selected RDRAM. The BR 0 -BR 3 bits are the bank address and specify one of sixteen banks to which the RowR command is addressed. The bits marked RsvB are reserved for other purposes. The AV bit is used to indicate whether the command packet is to be interpreted by the RDRAM command interface as a RowR command packet or another type of row command packet. In this case AV is set to zero to indicate a RowR packet. The bits ROP 0 -ROP 10 constitute an eleven bit row opcode. According to one embodiment, respective row opcodes are used to indicate the precharge (PRER), activate (REFA) and precharge post refresh (REFP) commands, among others. FIG. 10 is a diagram of a column command packet according to one embodiment that can be used to issue calibrate and sample commands. The column command packet is transmitted on the Co 10 -Co 14 signal paths of the channel, with a respective group of five bits being transferred in response to each of eight successive transitions of a clock signal (e.g., clock from master, CFM). Thus, a column command packet includes forty bits in all. The S bit and the M bit are used to indicate the type of column command packet. In this case, the S bit and the M bit are both set to zero to indicate a column command packet referred to as a ColX packet. In the ColX packet, the blank bits are reserved and the bits marked DX 0 -DX 4 are used to provide a five bit device ID. According to one embodiment, at least thirty-two RDRAM devices may be coupled to the channel (or extensions thereof) and programmed with one of thirty-two different identifiers. The five bit device ID indicated by bits DX 0 -DX 4 is compared to the identifier stored in a given RDRAM to determine whether the packet is addressed to that RDRAM. If so, a five-bit opcode in the XOP 0 -XOP 4 bits is decoded to determine the command. The command may be a calibrate command (CAL) or a sample command (SAM), among others. The RsvB bits and the unmarked bit positions are reserved for other purposes and the BX 0 -BX 3 bits are used to provide a bank address. In one embodiment, the bank address is ignored in the calibrate and sample commands. FIG. 11 is a timing diagram illustrating concurrent refresh and signal calibration operations. A refresh command sequence including PRER, REFA and REFP commands 41 , 43 , 45 is transmitted in three RowR packets on the row command port of the channel. The timing of this command sequence and the resulting refresh operation is described in reference to FIG. 2 . An exemplary signal calibration command sequence including three back-to-back CAL commands 141 , 143 , 145 followed by a CAL/SAM command 147 is also shown. An initial CAL command is issued during the same four bus cycles as the REFA command. As discussed above, this is made possible by the partitioning of the channel command path into distinct row and column command ports. Thus, a REFA command 43 is transmitted in a RowR packet on the row command port during the same time that a CAL command 141 is transmitted in a ColX packet on the column command port. During the time tRASmin that an activate operation is performed on the row being refreshed within the RDRAM core, the RSL calibration circuitry in the RDRAM is enabled so that a time tCALSTART after receipt of the first CAL command, current I OL begins to ramp through the enabled signaling circuit (see element 112 of FIG. 7 ). A second CAL command 143 is received after the first CAL command 141 so that the RSL calibration circuitry remains enabled. I OL begins to stabilize at the time shown in FIG. 11. A third CAL command 145 is received after the second CAL command 143 so that the RSL calibration circuitry remains enabled until Vcomp becomes valid. Recall that Vcomp is the output of the comparator (element 119 of FIG. 5) and is used to control whether the biasing signal to the RSL signaling circuits is adjusted up or down by a CAL/SAM command. A CAL/SAM command 147 is issued after the third CAL command 145 to disable the calibration circuit, latch the comparator value and assert the SAMPLE signal to the counter (see FIG. 5, element 114 and signal 117 ) and to adjust the count value up or down according to the latched Vcomp value. Thus, a signal calibration operation is completed concurrently with the refresh operation. It will be appreciated that the signal calibration operation may also be performed concurrently with multiple refresh operations to respective RDRAM banks, the multiple refresh operations also being performed concurrently with one another. In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly to be regarded in an illustrative rather than a restrictive sense.

An apparatus and method for concurrently refreshing first and second rows of memory cells in a dynamic random access memory (DRAM) component that includes a plurality of banks of memory cells organized in rows. A command interface in the DRAM component receives activate requests and precharge requests. A row register in the DRAM component indicates a row in the DRAM component. Logic in the DRAM component activates the row indicated by the row register in response to an activate request and precharges the row in response to a precharge request, the row being in a bank indicated by the activate request and by the precharge request.

RELATED APPLICATION This application is a national stage application under 35 USC §371 of PCT Patent Application No. PCT/US2010/053619, filed Oct. 21, 2010, which claims the benefit of U.S. Provisional Application No. 61/253,816, filed Oct. 21, 2009, U.S. Provisional Application No. 61/262,040, filed Nov. 17, 2009, U.S. Provisional Application No. 61/262,045, filed Nov. 17, 2009, and U.S. Provisional Application No. 61/264,651, filed Nov. 25, 2009, and PCT Application PCT/US2010/41774, filed Jul. 13, 2010. TECHNICAL FIELD This invention relates to a bariatric device for weight loss, and ancillary items such as sizing, deployment, and removal apparatus. BACKGROUND Obesity has been steadily increasing worldwide and poses serious health risks, which if untreated, can become life threatening. There are various methods for reducing weight such as diet, exercise, and medications, but often the weight loss is not sustained. Significant advances have been made in the surgical treatment of obesity. Surgical procedures such as the gastric bypass and gastric banding have produced substantial and lasting weight loss for obese patients. These procedures and products have been shown to significantly reduce health risks over time, and are currently the gold standard for bariatric treatment. Although surgical intervention has been shown to be successful at managing weight loss, both procedures are invasive and carry the risks of surgery. Gastric bypass is a highly invasive procedure which creates a small pouch by segmenting and/or removing a large portion of the stomach and rerouting the intestines permanently. Gastric bypass and its variations have known complications. Gastric banding is an invasive procedure which creates a small pouch in the upper stomach by wrapping a band around the stomach to segment it from the lower stomach. Although the procedure is reversible, it also carries known complications. Less invasive or non-invasive devices that are removable and capable of significant weight loss are desirable. SUMMARY The bariatric device described herein induces weight loss by engaging the upper and lower regions of the stomach. One embodiment of the bariatric device disclosed herein is based on applying force or pressure on or around the cardiac opening or gastroesophogeal (GE) junction and upper stomach and the lower stomach. It may also include pressure in the lower esophagus. The device can be straightened or compressed to allow for introduction down the esophagus and then change into the desired shape inside the stomach. This device may not require any sutures or fixation and would orient inside the stomach based on the device's geometry. The device may be constructed of three main elements: 1) A cardiac element that engages the upper stomach around the GE junction including the cardiac region and adjacent fundus and may include the lower esophagus. 2) A pyloric element that engages the pyloric region which includes the pyloric antrum or lower stomach. 3) A connecting element that connects the cardiac and pyloric elements. One of the purposes of the cardiac element which contacts the upper stomach or cardiac region would be to apply at least intermittent pressure or force to engage a satiety response and/or cause a neurohormonal response to cause a reduction in weight. This element could take the form of many different shapes such as a ring, a disk, a cone, frusto-cone, a portion of a cone, portion of frusto-cone, a sphere, an oval, an ovoid, a tear drop, a pyramid, a square, a rectangle, a trapezoid, a wireform, a spiral, multiple protuberances, multiple spheres or multiples of any shape or other suitable shapes. It could also be an inflatable balloon or contain an inflatable balloon. This balloon could be spherical, or it could be a torus or a sphere with channels on the side to allow food to pass, or it could be a cone, a portion of a cone or other shapes. The cardiac element may be in constant or intermittent contact with the upper stomach based on the device moving in the stomach during peristalsis. For the purpose of the claims of this patent, the “upper stomach” includes the cardiac region (a band of tissue in the stomach that surrounds the gastroesophogeal (GE) junction), and the fundus adjacent to the cardiac region, and may be either of these two areas, or both. Some of the purposes of the pyloric element are to engage the pyloric region or lower stomach, and to act in conjunction with the connecting element to provide support for the cardiac element to apply constant, intermittent, or indirect pressure against the upper stomach and or GE junction and lower esophagus. It is also to prevent the device from migrating into the duodenum or small intestine. This pyloric element would be preferentially above the pyloric valve and could be in constant or intermittent contact with the pyloric region or lower stomach based on movement of the stomach. Depending on the size relative to the stomach, this element may apply radial force, or contact force or pressure to the lower stomach which may also cause a satiety or neurohormonal response. Due to peristalsis of the stomach, the bariatric device may toggle back and forth in the stomach which may cause intermittent contact with the upper and lower stomach regions. The device may also have features to accommodate for the motion to allow for constant contact with the upper and lower regions. Similar to the cardiac element, the pyloric element could take several different shapes such as a ring, a disk, a cone, frusto-cone, a portion of a cone, portion of frusto-cone, a sphere, an oval, an ovoid, a tear drop, a pyramid, a square, a rectangle, a trapezoid, a wireform, a spiral, multiple protuberances, multiple spheres or multiples of any shape or other suitable shapes. It could also be an inflatable balloon. This balloon could be spherical, or it could be a torus or a sphere with channels on the side to allow food to pass, or it could be a cone, a portion of a cone or other shape. This element may activate stretch receptors or a neurohormonal response to induce satiety or another mechanism of weight loss by contacting or stretching certain portions of the stomach, to induce satiety, delay gastric emptying or another mechanism of weight loss. The form and structure of the cardiac and pyloric elements may vary to adapt appropriately for their purpose. For example, the cardiac element may be a ring while the pyloric element may be a cone or frusto-cone or any combination disclosed herein. Some of the purposes of the connecting element are to connect the cardiac and pyloric elements, to provide structure for the device to maintain its relative placement location, and to provide tension, pressure, or an outwardly biasing force between the pyloric and cardiac elements. The connecting element could take several different forms such as a long curved wire, a curved cylinder of varying diameters, a spiral of a single diameter, a spiral of varying diameter, a ribbon, an I-beam, a tube, a woven structure, a taper, a loop, a curved loop or other. Similarly, the connecting element could comprise multiple members to improve its structural integrity and positioning within the stomach. The connecting element could be generally curved to match the greater curve, lesser curve or midline of the stomach, could be straight, or a combination of any of the above. The connecting element could also be an inflatable balloon or incorporate an inflatable balloon. The connecting element could also be self expanding or incorporate a portion that is self expanding. Self expansion would allow the element or a portion of the element to be compressible, but also allow it to expand back into its original shape to maintain its function and position within the stomach, as well as the function and position of the other element(s). Self expansion would allow the elements to compress for placement down the esophagus, and then expand its original shape in the stomach. This will also allow the element to accommodate peristalsis once the device is in the stomach. This self-expansion construction of the connecting element may impart an outwardly biasing force on the cardiac element, the pyloric element, or both. In any of the embodiments disclosed herein, the device may be straightened or collapsed for insertion down the esophagus, and then reformed to the desired shape in the stomach to apply pressure at the upper and lower stomach regions or other regions as described above. At least a portion of the device could be made of a shape memory alloys such as Nitinol (nickel titanium), low density polyethylene or polymers to allow for it to compress or flex and then rebound into shape in the stomach. For placement of the device into the stomach, a flexible polymer tube, such as a large diameter overtube or orogastric tube, could be placed down the esophagus to protect the esophagus and stomach. The device could then be straightened and placed into the tube for delivery into the stomach, and then would regain its proper shape in the stomach once it exits the tube. Another variation for placement would be a custom delivery catheter to compress the device during placement and then allow the device to deploy out of the catheter once in the stomach. The bariatric device could be made of many different materials. Elements of the device could be made with materials with spring properties that have adequate strength to hold their shape after reforming, and/or impart an outwardly biasing force. The materials would also need to be acid resistant to withstand the acidic environment of the stomach. Elements of the device could be made of Nitinol, shape memory plastics, shape memory gels, stainless steel, super alloys, titanium, silicone, elastomers, teflons, polyurethanes, polynorborenes, styrene butadiene co-polymers, cross-linked polyethylenes, cross-linked polycyclooctenes, polyethers, polyacrylates, polyamides, polysiloxanes, polyether amides, polyether esters, and urethane-butadiene co-polymers, other polymers, or combinations of the above, or other suitable materials. For good distribution of stress to the stomach wall or to reduce contact friction, the device could be coated with another material or could be placed into a sleeve of acid resistant materials such as teflons, PTFE, ePTFE, FEP, silicone, elastomers or other polymers. This would allow for a small wire to be cased in a thicker sleeve of acid resistant materials to allow for a better distribution of force across a larger surface area. The device could take many forms after it reshapes. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 depicts a side view of a single wire embodiment the bariatric device of the present invention located within a cross-section of a stomach. FIG. 2 depicts a side view of an alternative single wire embodiment the bariatric device of the present invention located within a cross-section of a stomach. FIG. 3 depicts a side view of an embodiment of the bariatric device of the present invention located within a cross-section of a stomach. FIG. 4 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 5 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 6 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 7 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 8 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 9 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 10 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 11 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 12 depicts a side cross-section view of an embodiment of the bariatric device with an inflatable balloon, located within a cross-section of a stomach FIG. 13A depicts a side view of a cross-section of a stomach, identifying anatomical features. FIG. 13B depicts a side view of a cross-section of a stomach showing its approximate shape when undergoing contractions due to peristalsis. FIG. 14 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 15 depicts a side view of the embodiment of the present invention shown in FIG. 14 , located within a cross-section of a stomach that is undergoing contraction due to peristalsis. FIG. 16A depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 16B depicts an internal end view of a pyloric element of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach shown in FIG. 16A . FIG. 17A depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 17B depicts an internal end view of a pyloric element of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach shown in FIG. 17A . FIG. 18A depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 18B depicts an internal end view of a pyloric element of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach shown in FIG. 18A . FIG. 19 depicts a side view of the embodiment of the present invention shown in FIG. 18A , located within a cross-section of a stomach that is undergoing contraction due to peristalsis. FIG. 20A depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 20B depicts a side view of the embodiment of the present invention shown in FIG. 20A , located within a cross-section of a stomach that is undergoing contraction due to peristalsis. FIG. 21A depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 21B depicts a side view of the embodiment of the present invention shown in FIG. 21A , located within a cross-section of a stomach that is undergoing contraction due to peristalsis. FIG. 22 depicts a side cross-section view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 23A depicts an underside perspective view of an embodiment of the bariatric device of the present invention. FIG. 23B depicts a front view of an embodiment of the bariatric device of the present invention. FIG. 24A depicts an underside perspective view of an embodiment of the bariatric device of the present invention. FIG. 24B depicts a front view of an embodiment of the bariatric device of the present invention. FIG. 25A depicts an underside perspective view of an embodiment of the bariatric device of the present invention. FIG. 25B depicts a front view of an embodiment of the bariatric device of the present invention. FIG. 26 depicts a side cross-section view of an embodiment of the present invention, having an adjustment mechanism in the cardiac element in an inflated state, located within a cross-section of a stomach. FIG. 27 depicts a side cross-section view of an embodiment of the present invention, having an adjustment mechanism in the cardiac element in an inflated state, located within a cross-section of a stomach. FIG. 28A depicts an underside perspective view of an embodiment of the bariatric device of the present invention, having an adjustment mechanism in the cardiac element in an inflated state. FIG. 28B depicts a front view of an embodiment of the bariatric device of the present invention, having an adjustment mechanism in the cardiac element in an inflated state. FIG. 29 depicts a side cross-section view of an embodiment of the present invention, having an adjustment mechanism in the cardiac element in an inflated state, located within a cross-section of a stomach. FIG. 30A depicts an underside perspective view of an embodiment of the bariatric device of the present invention. FIG. 30B depicts a front view of an embodiment of the bariatric device of the present invention. FIG. 31A depicts an underside perspective view of an embodiment of the bariatric device of the present invention. FIG. 31B depicts a front view of an embodiment of the bariatric device of the present invention. FIG. 32 depicts a side cross-section view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 33A depicts an underside perspective view of an embodiment of the bariatric device of the present invention. FIG. 33B depicts a front view of an embodiment of the bariatric device of the present invention. FIG. 34A depicts an underside perspective view of an embodiment of the bariatric device of the present invention. FIG. 34B depicts a front view of an embodiment of the bariatric device of the present invention. FIG. 34C depicts an underside perspective view of an embodiment of the bariatric device of the present invention with one of the elements in a folded state. FIG. 34D depicts a front view of an embodiment of the bariatric device of the present invention with one of the elements in a folded state. FIG. 35 depicts a side view of an embodiment of the bariatric device of the FIG. 34A in a folded state, located within a cross-section of a stomach. FIG. 36 depicts a side view of an embodiment of the bariatric device of the present embodiment, located within a cross-section of a stomach. FIG. 37A depicts a side view of an embodiment of the bariatric device of the present embodiment, located within a cross-section of a stomach. FIG. 37B depicts an internal end view of the pyloric element of the embodiment shown in FIG. 37 A., located within a cross-section of a stomach shown in FIG. 37A . FIG. 37C depicts a side cross-section view of another embodiment for the pyloric element of FIG. 37A . FIG. 37D depicts an end view of the pyloric element of the embodiment shown in FIG. 37C . FIG. 37E depicts a side cross-section view of another embodiment for the pyloric element of FIG. 37A . FIG. 37F depicts an end view of the pyloric element of the embodiment shown in FIG. 37E . FIG. 38A depicts an underside perspective view of an embodiment of the bariatric device of the present invention. FIG. 38B depicts a front view of an embodiment of the bariatric device of the present invention. FIG. 38C depicts an underside perspective view of an embodiment of the bariatric device of the present invention with one of the elements in a folded state. FIG. 38D depicts a front view of an embodiment of the bariatric device of the present invention with one of the elements in a folded state. FIG. 39A depicts a side view of a pyloric element of an embodiment of the present invention. FIG. 39B depicts a side view of a pyloric element of an embodiment of the present invention. FIG. 40A depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 40B depicts a side view of a retainer strap and clip adjustment mechanism of an embodiment of the present invention. FIG. 40C depicts a side view of a retainer strap and clip adjustment mechanism of an embodiment of the present invention. FIG. 40D depicts a side view of a retainer strap and clip adjustment mechanism of an embodiment of the present invention. FIG. 41 depicts a side cross-section view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 42 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 43 depicts a side view of an embodiment of the present invention, equipped with adjustment mechanism shown in cross section, located within a cross-section of a stomach. FIG. 44 depicts a remote controller of an embodiment of the present invention, worn next to the user's body. FIG. 45 depicts a remote controller of an embodiment of the present invention, used without wearing or placing adjacent to the body. FIG. 46 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach. FIG. 47 depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach and a duodenum. FIG. 48 depicts a side view of a modular clip mechanism of an embodiment of the present invention. FIG. 49A depicts a side cross-section view of a modular clip in a closed position of the embodiment of FIG. 48 . FIG. 49B depicts a side cross-section view of a modular clip in an open position of the embodiment of FIG. 48 . FIG. 50A depicts an underside perspective view of an embodiment of the bariatric device of the present invention with modular clips. FIG. 50B depicts a front view of an embodiment of the bariatric device of the present invention with modular clips. DETAILED DESCRIPTION OF THE INVENTION The detailed description set forth below in connection with the appended drawings is intended as a description of presently-preferred embodiments of the invention and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the functions and the sequence of steps for constructing and operating the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. The most basic embodiment of the bariatric device 10 may have a single piece of Nitinol wire 11 which is shape set into a shape, but can be pulled under tension into a generally narrow and straight form, to allow for insertion of the device 10 through the esophagus. In such an embodiment, the elements may all be seamlessly integrated as one wire structure. See FIGS. 1 and 2 . Depending on the size of the stomach, the shape set wire may impart an outwardly biasing force to the proximal and distal elements of the bariatric device 10 , which may vary during peristalsis. In any of the embodiments discussed herein, the connecting elements 25 may be constructed of materials, or in such a manner, that may impart an outwardly biasing force, to push on the cardiac and/or pyloric elements. Such outwardly biasing force may impart constant or intermittent pressure to various parts of the stomach, through the cardiac element 12 , the pyloric element 26 , the connecting elements 25 , or any combination thereof. In the three-element embodiment (cardiac, pyloric, and connecting elements 12 , 26 , 25 ), the three elements may all be seamlessly integrated as one wire structure. When tension to flex, compress or stretch the device 10 is released, it may coil into a ring or loop near the cardia 40 , and coil into a ring or loop near the pyloric region 42 , with a curved member to connect the two elements that is shaped to relatively match the greater curve 17 of the stomach. The curve could also match the lesser curve 16 of the stomach or both. See FIGS. 3 and 4 . The connecting element 25 could curve into a single ring, or it could curve into a spiral. See FIG. 5 . As in other embodiments, the rings at each end could lock or not lock after forming, the rings may be closed, locked or continuous prior to placement down the esophagus, and could be compressed enough to fit within a placement tube for placement through the esophagus. See FIGS. 3 and 4 . As with other embodiments, the elements of the bariatric device 10 may have a variety of shapes to add pressure points that continuously move to stimulate the cardiac region 40 during peristalsis. See FIGS. 6 , 7 , and 8 . The device 10 need not be fixed into place but may be moveable, and generally self-seating. The device 10 may have a bias to fit the nonsymmetrical stomach shape and ensure that it seats into the cardiac region 40 and pyloric region 42 . Similarly, the action of peristalsis could create additional satiety signals as the device 10 moved in the stomach varying the pressure placed on the cardiac region 40 and/or the pyloric region 42 over time. In the three-element design shown in FIG. 3 , the connecting element 25 connecting the two rings could follow the natural curve of the stomach to match the greater or lesser curve of the stomach 17 , 16 , or could have both. This would aid in the seating of the device 10 in the stomach after placement. The connecting element 25 could have one or more connecting members 30 connecting the cardiac and pyloric elements 12 , 26 . See FIG. 4 . However, these members 30 should be flexible enough to allow for natural peristalsis to occur, natural sphincter function to occur and to not cause erosion or irritation of the stomach wall or significant migration into the esophagus or duodenum 19 . There could also be struts or supports that help to support the geometric shape of the rings to the connecting element 25 . The connecting element 25 could also be a spiral 28 or multiple spirals to create a flexible structure. See FIG. 5 . The connecting element 25 could also be bisected into two members that stack, telescope or articulate. The connecting element 25 could also have a joint such as a ball and socket type joint 29 or may be connected by magnets. See FIG. 9 . In another variation of the embodiments, there could be several rings 31 at each end of the device 10 to create an area of pressure at the upper stomach or cardia 40 . See FIG. 10 . The rings 31 should be sized appropriately to ensure that they do not protrude or slip into the esophagus 32 or into the duodenum 19 , unless a variation of this embodiment is designed to have some portion of the device 10 enter those regions. This will allow the device 10 to apply pressure to the upper stomach or cardia 40 without fixation or sutures. The force against the pyloric region 42 and/or lower stomach will provide the counterforce against the upper stomach or cardia 40 . At the same time, the force or contact against the pyloric region 42 and/or lower stomach may signal the body to stop eating. This force would mimic having a meal in the stomach with subsequent peristalsis, and sending the signal to stop eating. The multiple rings 31 could take the form of a spiral or could be separate rings 31 connected together. After reforming in the stomach, the rings 31 could lock, not lock, or be continuous. There are several ways that these elements could lock to form a ring. Another option for the cardiac element 12 would be to have a surface that contacts the upper stomach or cardia 40 such as a hemispherical or conical shaped shell 33 or balloon. The shape could also be asymmetrical but similar to a cone or hemisphere. This could be a thin walled element and could contain a lumen, no lumen, or a valve through which food could pass. FIG. 11 shows a valve 35 created by punching multiple crossing slits in an angular pattern through a thin walled membrane. In the case where there is no opening, the food would have to pass over the hemisphere or cone 33 which would have adequate flexibility to allow the food to pass into the stomach. These restriction elements may require the esophagus 32 to work harder to pass the food over the element and could better stimulate the stretch receptors in the stomach and indirectly in the esophagus. In another alternative, the hemispherical shell 33 could have multiple grooves or channels to aid in allowing food to pass. In the case where there is a lumen in the cardiac element 12 , it could be open or it could have a valve 35 that requires some force to allow food to pass through. An option could also be to have an esophageal member 36 that extends into the esophagus 32 for additional esophageal stimulation. This esophageal member 36 could be tethered by a thin structural member to support the esophageal member 36 , but not prevent the esophageal sphincter from closing. As mentioned above, this may require the esophagus 32 to work harder to pass the food and may better stimulate the stretch receptors in the stomach and indirectly in the esophagus. This esophageal member 36 could be a large tube, a small tube, a ring, a small sphere, multiple small spheres, or other suitable shapes. The pyloric element 26 could contain a restriction element, such as a lumen or a valve similar to the valve 35 shown in FIG. 11 for the cardiac element 12 . This restriction element could reduce the speed of food passing through the pyloric element 26 if desired. This valve 35 could be a thin membrane of silicone with a single or multiple slits punch through the center, or other types of valves could be used. See FIG. 12 . The membrane could also be the shape of funnel with a slit or circular opening, and made from elastomeric material to allow the funnel to expand open as food passes through. This drawing shows a pyloric element 26 with a valve 35 passing across the midsection of the pyloric element to slow down the passage of food. This drawing also describes a connecting element that could be comprised of an inflatable balloon 104 . This inflatable body could be compressed for placement and then inflated with a fluid or expandable foam or both to provide structure and adjustability after placement in the stomach. There is an inflation element 74 attached to the balloon where an instrument could be used to add or remove fluid to the inflatable balloon. Another alternative embodiment for the pyloric element 26 would be to change the orientation to allow the axis of the loop or ring in FIG. 11 to be perpendicular to the axis of the pyloric valve 18 as shown in FIGS. 14 and 15 . This may simplify manufacturing construction yet perform the same function. In such an embodiment, the pyloric element 26 could have the loop in a single plane, two crossed planes, or multiple planes. As mentioned above, the stomach experiences peristaltic waves when something is swallowed. FIG. 13A depicts a stomach cross-section showing the Z line and gastroesophageal (“GE”) junction 38 , the cardia or cardiac region 40 , the fundus 41 , the pyloric region which includes the pyloric antrum 42 , the pyloric valve 18 , and the duodenum 19 . FIG. 13B depicts the stomach's lesser curve 16 and greater curve 17 . FIGS. 13A and 13B respectively show a representation of the stomach profile when the stomach is at rest and when the stomach is fully contracted during peristalsis and the change in stomach diameter and length. Due to the change in stomach profile, it may be advantageous to have a design that can flex to change with the stomach profile to allow the design to slide or translate along the greater curve 17 or flex as needed, but maintain the relative position of the cardiac element 12 . FIGS. 14 and 15 show an alternate embodiment of the design to adapt to stomach profile changes. In FIG. 14 , it shows the cardiac element 12 engaging the upper stomach region while the connecting element 25 is a spring with two closed loops 44 at each end which can compress and flex to accommodate peristalsis within the stomach. FIG. 15 shows these loops 44 compressing during peristalsis to allow the device 10 to maintain its relative position in the stomach and preventing it from migrating past the pyloric valve 18 . Another variation of this embodiment would be to leave the loops open and allowed to flex until closed. Another variation would be to keep the loops closed, but include a mechanical stop inside the loop next to where the loop is closed to set a maximum amount that the device can flex. In yet another embodiment, the connecting element 25 may be made up of two or more members 30 . See FIGS. 16A and 16B . As shown in the drawing, the cardiac element 12 would contact the upper stomach or cardiac region 40 , while pyloric element 26 contacts the lower stomach or pyloric region 42 . The connecting element 25 has three members 30 , which are shown as curved wires or ribbons. One member 30 curves to match the lesser curve 16 (LC), while two other members 30 curve to match a median line between the lesser and greater curve 17 (GC), and curve to contact the anterior and proximal surfaces of the stomach to maintain its position even during peristalsis. FIG. 16A shows an optional location for the pyloric element 26 in the pyloric region 42 . FIGS. 17A and 17B shows a similar embodiment with another optional location for the pyloric element 26 closer to the pyloric valve 18 . In this embodiment, the pyloric element is not intended to contact or block the opening of the pyloric valve. In another embodiment, peristaltic motion may cause the device 10 to move inside the stomach and could cause the pyloric element 26 to slide from the relative locations such as those shown in FIGS. 18A , 18 B and 19 . These drawings show a three-element embodiment where the connecting element 25 may have four members 30 . FIGS. 18A , 18 B and 19 depict a similar embodiment to FIGS. 17A and 17B , but with an additional element to match the greater curve 17 . During peristalsis, the greater curve 17 will shorten, and the member 30 that matches the greater curve could flex inward to a convex form. After the peristaltic action is complete, the member 30 may spring back to its original concave form. Using these concepts, additional members 30 for the connecting element 25 may be used beyond the three and four members 30 described here, and could be located in a variety of locations along the midline, lesser curve 16 or greater curve 17 or any combination. FIGS. 20A and 20B depict an embodiment where the cardiac element 12 may be allowed to intermittently contact the upper stomach during peristalsis. The pyloric element may be a rigid or semi-rigid ring 49 and the connecting element 25 may be a spring to connect to the cardiac element 12 . Ideally, this ring is curved and smoothed to reduce the potential for irritation. In this embodiment, the ring 49 could engage the lower stomach at a fixed diameter when the stomach is at rest. Compression of the stomach during peristalsis would push the ring 49 towards the upper stomach to allow the cardiac element 12 to intermittently contact the upper stomach and/or cardiac area 40 . This may be advantageous to prevent overstimulation of the upper stomach or for other purposes. In yet another set of embodiments, the bariatric device 10 may be self expanding. FIGS. 21A and 21B depict an alternative embodiment where the cardiac and pyloric elements 12 , 26 are self expanding. These elements could be self expanding or have a portion that is self expanding to allow the device 10 to flex with peristalsis, but maintain tension to spring open to apply pressure or contact and position within the stomach. The self expanding portion could be made of Nitinol, silicone, polyurethane, Teflons, stainless steel, super alloys, or other suitable materials or combinations of suitable materials. FIGS. 21A and 21B shows a Nitinol wire mesh pattern 50 applied to a frusto-conical shape to create a shell. The Nitinol wire may act as a stiffening member within the cardiac and pyloric elements 12 , 26 . The Nitinol wire could be arranged in many different patterns to allow for the appropriate amount of self expansion while allowing the element to compress during peristalsis. The array pattern could include circular arrays, angular arrays, linear arrays, or other suitable arrays. The pattern could be woven or a continuous spiral. The self expanding function may also assist in deployment by allowing the device 10 to compress and then regain its shape. A preferred method of deployment is to compress the bariatric device 10 into a long narrow shape, which is then placed in a deployment tube, sheath or catheter. The collapsed and encased device 10 is then guided down the patient's esophagus 32 and into the stomach, where the bariatric device 10 is released from the deployment tube or catheter. Once released, the device 10 would expand to its original operational shape. The stiffening member, such as Nitinol wire, may provide adequate stiffness to expand the elements into their operational shape, and maintain that general shape during operation, while allowing flexibility to accommodate peristalsis. The embodiment depicted in FIGS. 21A and 21B show the cardiac and pyloric elements 12 , 26 connected by a connecting element 25 with multiple curved members, which are shown to be a Nitinol wire mesh array 50 , but could be made of Nitinol wire, silicone, teflon, another suitable material, or a combination of these materials. The four members of the connecting element 25 have different lengths to allow for proper alignment and seating within the stomach. FIG. 21B depicts how during peristalsis, the stomach will contract and its profile will reduce. The bariatric device 10 may shift and flex within the stomach, but the self expansion feature allows it to spring open and maintain its general position correctly. The connecting element 25 could have a pre-curved bend to form a living hinge to direct where the element should flex during peristalsis as shown in 21 B. As shown in FIG. 22 an embodiment of the cardiac element 12 may comprise a portion of a substantially flattened frusto-conical shape which is adapted to fit the cardia proximal to the esophageal/cardiac opening of a stomach. The cardiac element could also be a portion of a tube or it could be a flat panel, portion of an ovoid, ellipsoid, sphere or other shape. FIG. 22 also shows that a preferred embodiment of the pyloric element 26 may be a steep frusto-conical shape, or a tapered cylinder, which is adapted to fit the pyloric region 42 of the stomach, and preferably sized so that it does not migrate past the pyloric valve 18 . As discussed above, these elements may have a wide variety of shapes or may be inflatable, and these are only examples. The four connecting members may be constructed from 2 full loops or 2 loops connected together to create a “FIG. 8 ” structure. The loops could be contoured to generally follow the curves of the stomach, and could be connected to the pyloric and cardiac elements 26 , 12 in a variety of locations. The loops could be oriented to intersect at a variety of locations to provide different configurations with varying structural resistance and flexure points. For example, FIGS. 23A and 23B depict a bariatric device 10 where there are 2 separate closed loops 51 and the loops 51 are crossed in the pyloric element 26 so that the wires do not obstruct the distal opening of the element. The loops 51 are then aligned in a parallel pattern where they are attached to the cardiac element 12 . This allows the cardiac element 12 to follow the contours of the loops 51 even when the device 10 is laid flat and the loops 51 are compressed together as could be the case inside the stomach. This could allow for more uniform curved contact of the cardiac element 12 with the cardia 40 and adjacent fundus 41 . The parallel orientation of the loops 51 along the cardiac element 12 would provide less resistance of the device 10 just below the GE junction for a more gentle response. In another embodiment, the 2 loops 52 are connected in a “FIG. 8 ” pattern where the loops are 52 crossed in the pyloric element 26 and do not obstruct the distal opening of the pyloric element 26 . See FIGS. 24A and 24B The loops 52 cross again just below the opening of the cardiac element 12 , which allows the cardiac element 12 to flare more when the device 10 is laid flat and the loops 52 are compressed together such as would be the case inside the stomach. This could allow for more focused, linear contact of the cardiac element 12 with the cardia 40 and adjacent fundus 41 in the stomach. The cross of the loops 52 below the cardiac element 12 would provide more structural strength of the device 10 just below the GE junction 38 for more acute response. Where the connecting element loops cross, they may be joined together by a means of fixation to hold them together. These could be held together by adhesive or a separate joint connection 105 . The shape of the joint connection could follow the shape of the connecting element or it could be a portion of a frusto-cone or other. To increase the acute response, a stiffening member such as a wire loop or other could be added cardiac element 12 to direct stiffness in a desired area. FIGS. 25A and 25B show one possible orientation for a stiffening member, but other orientations, shapes and additional members could be added to generate a specific response. FIGS. 25A and 25B also show a cardiac element with 2 members, the first member being proximal and the second member being distal to apply pressure in these focused areas. These members are shown as portions of a frusto-cone, but could be different shapes. Similarly, these members of the cardiac element could also be oriented in different locations. Another variation of this embodiment could include an inflatable member 76 placed on top of the cardiac member to allow for adjustability of the device once it is in place. FIG. 26 shows a side view of an embodiment with the inflatable member 76 . This member could have an inflation element, which could be a self sealing septum, valve or self sealing membrane on the surface of the inflatable member itself. In FIG. 26 , the inflation element is not shown, but could be located near the pyloric element for ease of access, but could also be located at different sites. FIG. 27 , shows a variation of the inflation element where the valve 74 is attached to the cardiac element by a retractable inflation tube 106 . The retractable inflation tube 106 may be constructed of a coiled tube, which may be may be contained in a housing. Alternatively, the retractable inflation tube 106 may be attached to a separate leash or tether. The valve 74 can be grasped inside the stomach using a standard grasper or snare, and then pulled up the esophagus for access outside the body while maintaining the device inside the stomach. The inflation element may be a slit valve that can be accessed by a blunt needle or small diameter instrument to push through the valve to allow fluid to be added or removed. After the appropriate volume of fluid has been added, the retractable inflation tube 106 can then be placed back into the stomach. Preferably, the retractable inflation tube 106 would be designed so that it would not pass through the pylorus. FIGS. 28A and 28B show a front and back side view of the inflatable member 76 in an inflated state. In another embodiment, FIGS. 29 , 30 A, and 30 B show a configuration where the connecting loop elements form a FIG. 8 , and the cardiac element 12 is constructed from a wireform similar to the stiffening member. The stiffening member could be in a variety of other orientations, shapes or patterns, and additional members could be added to engage specific areas of the stomach to generate a specific response. This element could also be adjustable in length, width, curvature or shape to generate a specific response. In another embodiment, FIGS. 31A and 31B show an embodiment where connecting loop elements form a FIG. 8 , and the pyloric element is constructed by the 2 connecting loops crossing with connecting element joints 105 . The crossed connecting elements would engage the lower stomach to provide adequate resistance from passing the pylorus while maintaining pressure against the upper stomach. Additional loops could be added to the pyloric element or cardiac element to create a variety of profiles. In another embodiment, FIGS. 32 , 33 A, and 33 B show a cardiac element that is focused on the distal cardia. Similar to the other embodiments, this cardiac element may also contain a balloon to inflate to change the width of the device. In another embodiment, the cardiac and pyloric element may have substantially the same shape. See FIGS. 34A , 34 B, 34 C, 34 D and 35 . These figures show a device where the both elements are self-expanding flattened frusto-cones. Since the proximal and distal portions are the same, the device is symmetrically arranged on the connecting element and can be placed in either orientation. In another variation, the device may not be symmetrically arranged. In the symmetrical embodiment, the device can migrate out of position and/or rotate, and then re-seat with peristalsis without concern of regaining the proper orientation. As shown in FIGS. 34C , 34 D, and 35 when the flattened frustocone is placed or migrated into the antrum or lower stomach it may fold to create a wavy structure. Because the structure is wide, the device may sit higher in the lower stomach, above and adjacent to the proximal antrum and the incisura angularis. It may also sit at the proximal antrum. During peristalsis, the device 10 may move in the stomach, but may come to rest near the proximal antrum when the stomach is at rest or it may sit lower. Similarly, the connecting elements used in this embodiment have the same profile for the proximal and distal portions which have a wide profile and may prevent the distal portion from seating low near the pyloric valve or contacting the pyloric valve. This folded structure may act as a restriction element, creating a tortuous path or a valve for chyme to pass through prior to passing through to the area adjacent to the pylorus and through the pyloric valve. The restriction element may aid in slowing gastric emptying and increase a feeling of satiety. Although the figures show a device with a flattened frusto-cone, many other shapes may be used. These shapes could be could be a ring, a disk, a portion of a cone, portion of frusto-cone, a sphere, a portion of a sphere, an oval, an ovoid, a tear drop, a pyramid, a square, a rectangle, a trapezoid, a wireform, a spiral, a preformed wavy shape, multiple protuberances, multiple spheres or multiples of any shape or other suitable shapes. It could also be any other shapes previously described. These shapes could fold and change form once placed into the stomach to perform a different function such as slowing gastric emptying by creating a tortuous path. Similarly, the element could be preformed with folds or waves. Given that the cardiac and pyloric elements may have the same shape in certain embodiments, and/or may be interchangeable in position within the stomach, the claims may refer to them as a first element and a second element. These cardiac and pyloric elements may also contain a restriction element to slow gastric emptying. Such restriction element could comprise an additional membrane or valve. FIG. 36 shows a device with a proximal and distal element that are hemispherical thin walled shells 33 . These restriction elements may comprise a valve 35 with multiple slits to reduce the flow of food through either element. As a variation, a restriction element could also comprise a hole to allow for food to pass through or no lumen to allow food to pass around the elements as they flex or fold. Another variation of the restriction element to slow gastric emptying would be to have a thin walled flexible membrane, small protrusions, wire loops, or fingers that extend from the inner surface of the cardiac or pyloric elements. FIGS. 37A and 37B shows the example of a device with a conical pyloric element with a thin walled flexible membrane 35 crossing through the center of the element. This membrane shows an oval opening, but the opening could be a slit, a hole or other shape. In this embodiment, the pyloric element has a wide profile and may maintain its position near the proximal antrum and the incisura angularis. In this embodiment, the device is not intended to directly contact the pyloric valve or pyloric opening. In other embodiments, however, the pyloric element may be sized to contact those areas. FIGS. 37B , 37 C, 37 D, and 37 F show other examples of a restriction element, which may include a reduced lumen, valve or tortuous path to reduce the flow of food through the pyloric element 26 . FIGS. 37C and 37D show multiple flexible members 107 that extend from the internal surface of the pyloric element 26 to reduce the flow of food. Similarly, FIGS. 37E and 37F show multiple flexible members 107 that cross the internal surface at different heights to slow gastric emptying. In another embodiment, the same structure as described above for the foldable pyloric element 26 may be combined with a different cardiac element 12 such as the wireform structure shown in FIGS. 38A , 38 B, 38 C, and 38 D This could combine unique features of the wireform to apply pressure at the cardia, while also using the folded design as a restriction element for slowing gastric emptying through the proximal antrum. As described above, any combination of cardiac and pyloric elements disclosed herein can be used. Where the connecting element 25 is formed from loops, the loops could be formed from Nitinol wire. The Nitinol wire used for the connecting elements or any elements in the device could be passivated to improve acid resistance. They could also be coated in an acid-resistant coating 53 such as silicone or silicone covering, PTFE, or other suitable coating, or not coated. These loops could also be made of spring steel, stainless steel, super alloys, teflons or other suitable materials or combinations of materials. The loops could be closed or connected in a variety of ways. For the example of Nitinol, the loops could be closed by a glue joint where the wire loop ends are glued inside of another tube. They could also be closed by a crimping, swaging, welding or joined by a mechanical mechanism. The loops could also be left open, if a feature is added for adjustability and it is preferred to have the loops open with both ends fixed to the elements as needed. The contact members of the elements may be comprised of a variety of materials. For example, the Nitinol wire pattern of the cardiac, pyloric, and or connecting elements 12 , 26 , 25 , may be exposed for direct contact with the stomach or the wire could be covered or sealed in another material, such as silicone, PTFE, polyurethane or other suitable materials. For example, FIG. 39A depicts a pyloric element 26 where the wire mesh 50 is covered in another material to create a smooth surface for the contact member 54 to facilitate sliding within the stomach. Alternatively, FIG. 39B shows the wire exposed to the stomach mucosa surface. This shows how the wire array 50 could be arranged and formed to add a wavy pattern to increase to profile of the wire above the element's nominal surface, which in this case is shown as a cone with the wire protruding above the cones surface. This would allow the wire to act as a macro texture surface for the contact member 54 to grip the stomach surface to reduce sliding or it could provide a macro texture for tissue ingrowths. The Nitinol may be treated with a surface finish, passivation or coating to improve its acid resistance within the stomach. The contact and stiffening members of the elements may be separate, entirely integrated, or both. For example, if a cardiac element 12 is made entirely of Nitinol wire, the wire acts as both a contact member and a stiffening member. The same would apply if an element were made entirely of silicone; the silicone would act as both a stiffening and contact member. In another embodiment, where Nitinol wire is embedded in another material such as silicone, the Nitinol wire acts as a stiffening member and the silicone acts as a contact member. In another embodiment, the Nitinol wire may be partially exposed and partially covered by the silicone (and/or on the interior of the element), in which case the Nitinol wire acts as both a stiffening and contact member. In certain embodiments, the combination of materials may act as a stiffening member. For example, an embodiment where the contact member is silicone with Nitinol wire embedded, the silicone may act in conjunction with the Nitinol to provide more stiffness than the Nitinol could achieve alone. Various combinations of stiffening and contact members may be apparent to those skilled in the art. As mentioned above, a preferred device 10 has adjustability or adaptability to match any changes in the patient over time. A variation of the above embodiments would be to allow the device 10 to be adjustable via an adjustment element 60 . This adjustability could be in the length, shape, angle or stiffness of the cardiac, pyloric, and/or connecting elements 12 , 26 , 25 . Similarly, different sized devices could be manufactured and the device replaced with a different size. The bariatric device 10 could be adjustable to allow for adjustment at the time of placement or could be adjusted at a later time. This adjustability could be achieved by having a variable spring tension in one of the elements to allow the device 10 to extend, contract, or distort as needed. It could also be achieved by adding an expansion joint 75 in a member to elongate or compress as needed. This expansion could be a manual adjustment performed by the physician in the office through a gastroscopic procedure. This expansion could be achieved by various mechanisms, including but not limited to those operated by: rotating a threaded member, ratcheting backwards or forwards, a hydraulic mechanism, a pneumatic mechanism, a cam, a tension mechanism, a telescoping mechanism or other elongation or contraction mechanisms. The outer surface of the connecting element 25 is preferably smooth with rounded or gently angled edges to prevent irritation of the stomach during peristalsis, although sharp angles may be preferred in some applications. To create a smooth interface, these elements could be encased in a sleeve or sheath that could be removed or remained fixed during the expansion. A sheath may not be required if the expansion joint 75 is designed with smooth contours on its own. Manual Actuation The device 10 could also be adjusted by manual means inside the stomach by using a gastroscopic instrument to come into direct contact with the device 10 . The instrument could also act as a pusher or puller to activate a pulley mechanism or a clipping mechanism. For example, the connecting element 25 could be a ratchet or strut with multiple positional features such as holes, grooves, teeth or wedging action. The device 10 could have a feature to engage the ratchet teeth or positional features such as a pin or clip or other. The instrument could retract the pin or compress the clip and then reposition this feature in the next available location. In another embodiment, the members of the connecting element 25 could have multiple beads or spheres 62 that are captured by a cuff or ring retainer on the cardiac element 12 . An instrument could be used to expand the cuff to pull the bead through for positioning. Similarly, the cuff could have a keyway retainer feature that allows the bead to only fit through a specific location and then lock into position where the beads connect to the wire or ribbon or tube. FIGS. 40A , 40 B, 40 C and 40 D shows several examples of compressible clips 65 acting as a “bead” or positional feature that could be used for adjustability. For example a retainer strap 63 of silicone could be bonded on both sides to create a narrow passageway 66 where the clip 65 could be placed in the compressed position, and then expand open after passing through the strap 63 to maintain its position. Several straps 63 could be bonded in a row to create several positional locations. FIGS. 40B and 40D shows the clip 65 in is open, relaxed state, where 47 C shows the clip 65 in a compressed state where it can pass through the retainer strap 63 . Another option for adjustability would be to use a locking ring to fix the location of the connecting elements 25 into the pyloric element 26 . The pyloric element 26 could have several positional features connected to it. The connecting element 25 could also have several positional features attached to it. When the positional features of the pyloric element and connecting loop are aligned, a locking ring could be placed inside to hold the position of the elements together and to alter the length of the whole device 10 to be longer or shorter. In another embodiment, the ring could be fixed to the pyloric element 26 and compressed to capture the positional features located along the connecting element 25 . In another embodiment, an instrument could act as a screw driver to rotate a member to thread the two elements closer or farther apart. The instrument could also have a needle to inject fluid into an inflation element 74 . Such an element may be a self sealing membrane to increase or decrease the length, diameter or stiffness through positive displacement of an expandable body. The self sealing membrane could be an injection port or it could be a self sealing surface on the expandable body, or the entire expandable body could be comprised of a self sealing surface. In all descriptions below, the term inflation element 74 can also refer to an injection port or to an area on the expandable body with a self sealing membrane. The self sealing membrane could also be a self sealing valve which can be accessed by a blunt needle or tube to allow access to add or remove fluid. The valve could be attached directly to the expandable member or it could be attached by a tube. FIG. 41 shows an inflation element 74 fixed to the pyloric element 26 or the connecting element 25 . This valve or port could be connected by a fluidic path to an expandable body such as a sealed inflatable body inside of an expansion joint 75 such as a piston and cylinder. The valve could be accessed by an endoscopic instrument with a blunt end, while an injection port could be accessed by an endoscopic instrument with a non-coring needle where saline or other suitable fluid could be injected or removed from the port which would allow the inflatable body to expand or contract to control the length of expansion. Although this figure shows one expansion joint 75 , the device 10 could contain one or more with a manifold set up to deliver fluid from the port to all of the expansion joints. In an alternative embodiment, the system could also have an expandable body such as a syringe type joint which would not require a sealed internal inflatable body. FIGS. 26 , 27 , 28 A, and 28 B show an embodiment, where an inflatable body could be located on the cardiac member. An inflatable body could also be placed on the pyloric element(s) to increase the length or diameter. An inflatable body could also be placed along the connecting element to change the profile of the device. An embodiment could contain one or more inflatable bodies at the cardiac, pyloric, or connecting elements or any combination of the above. Inflating fluid, which could be saline, water, air, or other suitable substances, may be inserted or removed through the inflation element 74 to increase or decrease the size of the inflatable body 76 . In such manner, the amount of contact and/or pressure imparted by the cardiac element 12 on the cardiac region 40 and/or the upper region of the stomach may be adjusted, either while the device 10 is in the stomach, or prior to placement. This balloon could cover the entire cardiac surface or could only cover portions of the cardiac surface to direct the inflation for a specific response. There may be one or more inflatable portions on the cardiac element 12 . The device 10 could contain linear and radial inflatable bodies. A gastroscopic instrument could also deliver heat directly to an expandable body such as a heat expanding mechanism (such as one made of Nitinol) for expansion of a wax or wax-like expansion member. For example, a Nitinol clip could clip into a positional location on a strut. The instrument could heat the clip to release and then reposition it into a different location, remove the heat and allow the clip to re-engage the positional feature to lock it into place. The instrument could also have an inflatable body or a balloon to allow for physical contact with the device 10 to disengage a feature for repositioning into another location. Magnetic actuation. Another adjustment mechanism could use magnets. See FIG. 42 . For example, the connecting element 25 could contain a thread with a magnetic nut 79 placed over it. Another strong magnet, the controller magnet 80 , could be placed in close proximity to the implanted magnet to cause it to rotate. The rotation of the controller magnet 80 could create a magnetic field which would cause the internal magnet 79 to turn allowing it to advance and retreat along the threaded member 81 . The controller magnet 80 could either be external to the body or it could be placed on the end of a gastroscopic instrument for close proximity. The controller magnet could be a magnet or an electromagnet to increase the intensity of the field and to improve magnetic coupling to ensure actuation. The controller magnet 80 could also be multiple magnets to improve magnetic coupling. Another means of manually adjusting the length of the device 10 would be to have modular pieces that could attach or adhere to the cardiac or pyloric elements 12 , 26 . For example, an additional frusto-cone could be placed over the pyloric element 26 to increase the length of the overall design. Several could be stacked together to create a variety of lengths. Stacking frusto-cones could also be distanced from one another with a balloon on either frusto-cone to increase the distance between the two. A variation of this embodiment would be to have an additional member that could be collapsible or compressible and inserted down the center of the pyloric element 26 . Once it passes the pyloric element distal surface, the modular element would expand and attach to the outer surface. Several modular elements could be stacked together to create a variety of lengths. An alternative embodiment could have an additional element that could also pass down the center of the pyloric element 26 and expand past the distal surface, but with a clip that would allow it to remain clipped to the inside surface. The attachment mechanism could be positionally based so that the element could be repositioned to several locations for a variety of lengths. There could be several other means for manually actuating the design for repositioning. As another variation of the above embodiments, the manual expansion mechanism could be adjusted remotely by an apparatus outside the body, and/or automated. The expansion could be achieved by a small motor that could be driven by an implanted power source or driven by a remote power source such as induction. Energy could also be supplied by an RF signal, kinetic energy, ultrasound, microwave, cryogenic temperatures, laser, light, or thermal power. Power could also be supplied by a battery or implantable power cells that utilize glucose or other means for fuel. The automated expansion could also be achieved by a pump, a syringe type plunger, a piezoelectric crystal, a bellows, a Nitinol motor, a pH responsive material that changes shape, thermal expansion of a gas, fluid or solid (example wax) expansion, magnet forces or any other type automated expansion or compression mechanism. The control for activating this mechanism could be a remote control using a radiofrequency signal which can pass through tissue. The remote control could also be achieved by magnetic fields, time varying magnetic fields, radio waves, temperature variation, external pressure, pressure during swallowing, pH of any frequency or any other type of remote control mechanism. Actuation Mechanisms Stepper Motor: To adjust the length of the connecting element, 25 to increase the direct force onto the upper stomach or cardia 40 , the adjusting element could be connecting element, 25 entirely or partially comprised of a flexible, semi-flexible or rigid screw. A stepper motor 85 could be placed onto the flexible thread and could drive forward or back to allow the connecting element, 25 to draw together or push apart the elements. See FIG. 43 . These figures represent a threaded element that can be drawn together or apart. The adjusting element may require power to drive the motor 85 . The power could be supplied by an implanted power source such as a battery or it could be powered externally by induction through the coupling of an external antenna and an internal antenna. An option would be to embed the internal antenna into any or all of the elements. This would allow for fewer structures in the design by encasing the antenna inside of one or more of the existing elements. The antenna could be a simple ring at the top or bottom or obliquely on either element or it could be placed in the wall of the device 10 . The internal antenna could also be attached by a tether, free floating inside the esophagus, stomach or intestine. These could be made from materials to make them MRI compatible and/or MRI safe. This feature could be applied towards any actuation method where it is powered by induction. For induction, an external hand held controller 86 may be required to transmit power for coupling. See FIGS. 44 and 45 . The controller 86 could be set up to auto detect the internal antenna's presence and identify when coupling between the two antennas was adequate to allow for transmission and powering to take place, and to inform the user of function. This external controller 86 could then be used to display the distance that the stepper motor 85 had been advanced or retracted to allow the physician to control the adjustment. Similarly, the external controller 86 could be used for communication and control signals as an interface between the physician and the placed device 10 . This feature could be applied towards any actuation method powered by induction. An external antenna would be required for induction and could be placed into an external handheld controller 86 . This could be placed directly against or close to the patient's body at the height of the internal bariatric device 10 . The antenna could be housed with the other controller electronics in a single unit. This feature could be applied towards any actuation method powered by induction. Another alternative would be to have the external antenna in the form of a belt 87 that would wrap around the patients abdomen at the height of the device 10 to better align the antennas for improved coupling. This feature could be applied towards any actuation method powered by induction. The location of the actuation mechanism could also be inside any of the elements, or above or below any of them, or another location as would be best suited for the anatomy and function of the device 10 . This feature could be applied towards any actuation method. Actuation could be accomplished by allowing the screw to be pushed or pulled inside any of the elements to embed the adjustment mechanism internally to one of the other elements. Other actuations mechanisms such as those listed above or others could also be used for this adjustment. Induction could also be powered by an intragastric instrument. The instrument could have a flexible shaft that could fit through the mouth and down the esophagus or down the working channel of a gastroscope. Once the instrument was placed within or near the esophagus or stomach, it would allow the instrument to be in close proximity with the actuation mechanism in the device 10 . The end of the instrument could have antenna(e) to allow for inductive powering and/or communication with the actuation mechanism for adjustment. This feature could be applied towards any actuation method. Piezoelectric Motor The adjustment could also be achieved by a piezoelectric element or motor 85 . See FIGS. 43 . These figures represent a threaded element that can be drawn together or apart. There are several types of piezomotors that could be used for linear actuation. For example, a motor from NewScale Technologies (www.newscaletech.com) called the Squiggle Motor could be used which is very low profile and can be actuated when powered. Other motors or actuation mechanisms could also be used, and the Squiggle motor is just used as an example. In this example, there is a rigid screw that passes through the center of a threaded piezoelectric “tube” or element. When powered the piezoelectric element flexes side to side along the central axis to create an oscillating “hula hoop” action which causes it to translate axially along the rigid screw. The Squiggle motor could be attached to the connecting element, 25 to advance or retract the cardiac and/or the pyloric element 12 , 26 . Alternatively, the Squiggle motor could be placed in between any of the elements. Alternatively, more than one Squiggle motor could be placed at these locations. One of the advantages of a piezoelectric motor 85 is that it would allow the device 10 to be MRI compatible and safe. As mentioned with the stepper motor 85 above, the piezoelectric motor 85 could be powered by an internal power source such as a battery or it could be powered by remote induction. The remote induction could be by a handheld external controller or it could be by a gastroscopic instrument placed down the esophagus. This motor could be encased in other materials to keep it dry and protected from the stomach environment. Another embodiment of a piezoelectric actuated motor 85 would be to have a rotating piezoelectric member that could thread along one or two threaded members similar to a worm gear. Another embodiment of a piezoelectric actuated motor 85 would be to have a piezoelectric crystal that elongates or flexes to actuate another member. All of the piezoelectric motors 85 may contain a sealed housing such as an expandable metal or plastic bellows to prevent moisture of fluid from contacting the piezoelectric elements. Magnetic Actuation As mentioned above in the manual adjustment section, another adjustment mechanism could use magnets. See FIG. 42 . For example, at least a portion of the connecting element could be a semi-flexible thread or rigid thread with a magnetic nut placed over it. Another strong magnet, named a controller magnet 80 , could be placed in close proximity to the implanted magnet to cause it to rotate. The rotation of the controller magnet 80 could create a magnetic field which would cause the internal magnet to turn allowing it to advance and retract along the threaded member. The controller magnet 80 could either be external to the body or it could be placed on the end of a gastroscopic instrument for close proximity. The controller magnet 80 could be a magnet or an electromagnet to increase the intensity of the field and to improve magnetic coupling to ensure actuation. The controller magnet 80 could also be multiple magnets to improve magnetic coupling. Nitinol Actuation The adjustment element could also be actuated by Nitinol or a substance with similar properties. When a current is passed through Nitinol, it heats and causes the Nitinol to change its shape. Nitinol can expand into a variety of different shapes. A linear actuator could be made from Nitinol to advance or retract along an actuation member. Heat could be generated from an implanted battery or it could be delivered by induction. The connecting element could have multiple positional features such as holes, grooves, teeth or a wedging feature. A Nitinol clip could have a feature to engage these positional features. The Nitinol clip could be heated to change shape to allow it to advance or retract into different positional features to increase or decrease the length. There are other Nitinol actuations that could be provided as well. Ultrasound Motor Another adjustment mechanism could be by use of an ultrasound motor or one powered by external ultrasound. This could use external ultrasound equipment to send sonic waves into the body to actuate the motor. This would also provide an MRI compatible option without requiring an internal power source or induction. Hydraulic Actuation The adjustment element 60 in FIG. 46 could also be actuated through hydraulic means for radial expansion or linear actuation as previously described. The cardiac or pyloric element 12 , 26 could be inflated with a fluid to increase the diameter or length of the device 10 to increase pressures against the upper stomach or cardia 40 , and pyloric region 42 . It could increase in volume by accessing a self sealing membrane such as a self sealing drug delivery port, self sealing membrane on the expandable body, or a self sealing valve attached to the device 10 . The inflation could be achieved by a piezoelectric pump, a peristaltic pump, a positive displacement pump or a syringe pump. Piezoelectric pump: The pump could be comprised of a piezoelectric element which can flex to propel fluid directly or a member that could propel fluid. For example, a piezoelectric disk could be captured in a housing with an incoming channel and an outgoing channel. The disk could be powered to cause it to flex into a dome shape to push fluid into the outgoing channel. A valve would be required to close the incoming channel to ensure directional flow to the outgoing channel. Similarly, the piezoelectric Squiggle motor as described above could be used to linearly actuate a fluid up or down a tube to hydraulically actuate position. Stepper motor pump: Actuation could be achieved by a stepper motor where the motor linearly actuates to compress a reservoir or syringe to move fluid within a tube or constrained volume. Wax expansion pump: Fluid could also be propelled by a wax expansion mechanism. When wax is heated to melting it expands by approximately 30%. A solid plug of wax could be heated to expand and drive fluid through a valve to hydraulically actuate lengthening. The lengthening structure could be made to move only in one direction, so that when the wax cools it will not contract. The wax expansion could also be used to actuate other adjustment mechanisms. Peristaltic pump: The members could also be driven by a peristaltic pump. In this mechanism, the external diameter of a cylindrical actuator could be used to compress a length of tubing to create an occlusion. The cylindrical actuator could be rotated along the tube to drive fluid forward or backwards inside the tube. The peristaltic pump could also be actuated by a stepper motor or by a piezoelectric element or other. Gas expansion/propellant pump: The length could also be actuated by a gas expansion pump where a gas like Freon or others could be used to expand when exposed to a higher temperature. Similar principles to the devices like the Codman pump could be used. This change in volume could drive the pump forward. Similarly, there could be compressed gas constrained in a pressure vessel with a valve. The valve could be remotely activated to allow gas to propel a syringe, fluid or to compress a constrained volume. Positive displacement pump: There are implant grade positive displacement pumps that are available on the market for drug delivery that could be used to displace a specific amount of fluid for hydraulic inflation of the adjustment element 60 . Syringe pump: A syringe pump could be made by advancing fluid through a syringe. The syringe could be actuated by a stepper motor, a piezoelectric actuator, a magnet or by a Nitinol actuator as described above. Hydrogel: the adjustment element could also be inflated by use of a hydrogel to absorb fluids and could be actuated by changes in temperature, pH or tonicity to change shape or volume Hypertonic fluid: the adjustment element 60 could also be inflated by using a hypertonic fluid in the inflation area and allowing it to absorb fluid across a semi permeable membrane. Mechanical means for diametrical changes. Similar to the inflation, elongation, and shortening embodiments described above, the device 10 could change diameter by various actuation mechanisms. All of the above-described mechanisms could also be adapted for use for a diametric change instead of a linear change. As a variation of the embodiments discussed above, the device 10 could have a sensor 88 that could sense a parameter such as pressure, motion, peristalsis, tension, pH, temperature, chemical or other appropriate parameters, or various parameter combinations. The sensor 88 could output a signal to be used by an actuation element to actuate an adjustment element, to a memory element such as a microchip, or be read by a remote reader or remote controller. Sensors 88 could be used to gather important patient data to understand performance, patient status or whether an adjustment needs to be performed. For ease of use and compatibility with the body, wireless sensors would be preferred. The sensors 88 could be direct tissue contact, intermittent patient contact or could monitor the intraluminal pressure inside GI tract. The data could be used for no other reason than to just monitor patient status. FIG. 46 depicts sensors 88 , which could be embedded in any of the elements or it could be tethered to any of the elements to allow it to be suspended inside the GI tract. Based on the sensed parameter, the device 10 could be adjusted. The adjustment could have an open or closed loop system increasing or decreasing the applied force, pressure or sensed parameter. The sensed parameter could detect whether the device 10 was not at an ideal condition, and could then send a signal to a control mechanism for automatically adjusting the system. This mechanism could be under physician control (open system) or without physician control (closed system). The adjustment could also be a manual adjustment where the parameters are being monitored to guide the adjustment. It could also control the shape of the cardiac, pyloric, and/or connecting elements 12 , 26 , 25 to vary stiffness, size, length, form or shape. In general, the sensor 88 could sense a parameter and then adjust the device 10 as needed to bring the sensed parameter into the ideal range. There could be an algorithm that controls the ideal parameter or it could be based on a parameter range. The device 10 would be adjustable to meet the needs of the patient. In an open loop system, the physician would have control of when the device 10 would adjust. The device could have it owns internal power source or the device 10 could be passive and only inductively powered when in close proximity to an external controller under the supervision of a physician. For example, in the clinic the physician could have a remote controller with the ability of powering the device 10 inductively, and then begin to monitor the sensors feedback signals to see physical parameters of the patient at baseline such as pressure of the device 10 against the cardia. The sensor monitoring could also be performed while the patient is eating or drinking, or not eating or drinking. As the patient consumes, the esophageal and stomach peristaltic waves will increase in intensity as they propel the food or drink from the mouth to the stomach. A sensor 88 could detect when these waves increase in amplitude, frequency, and pressure. The parameter could read on the external controller by the physician, and then the physician could send a signal to the automated expansion mechanism in the device 10 to adjust the device. The physician could then query the sensor 88 again to determine whether the device 10 was in the ideal settings and whether the pressure against the cardia or sensed parameter was optimized. The physician could iteratively control the amount of adjustment and monitor the parameters until the ideal condition was met. Where the device has its own power source, the physician may still have the control to wake up the device, query the sensors and then adjust the device as described above. The only difference would be that the device was powered by the power source and not require inductive power from outside. Alternatively, the physician could read the parameter signals while under his supervision, but have the sensors 88 send a signal directly to the automated expansion mechanism to adjust until the device 10 was within the ideal parameters. The data collected could be analyzed by the controller for averages, minimums, maximums and standard deviations over time and use an algorithm to determine the ideal settings. The controller could then monitor and adjust on its own until the ideal conditions were met, but while the physician was present to verify all conditions and verify patient acceptance. In a closed loop system, the device 10 would be active with its own integrated power source. The device 10 could wake up at routine intervals to monitor or could monitor all the time. The data collected could be analyzed for averages, minimums, maximums and standard deviations over time and use an algorithm to determine the ideal settings. As the patient begins to consume food or drink, the device sensors 88 would detect the sensed parameter and signal the automated expansion/contraction mechanism to adjust the device 10 as needed. In this embodiment, the device 10 could be fully automated and would not require intervention from an outside individual. In either the open or closed loop system, there could be multiple sensors 88 on the device 10 to determine the pressure or force areas, or other sensed parameters on the device 10 and where it needs to be varied to meet the ideal conditions for the stomach. In the case where the connecting element 25 has multiple components, this could be used to align the device 10 in the stomach to provide a custom fit for each person. There could also be a mechanism to adjust the alignment of the cardiac and/or pyloric elements 12 , 26 relative to the connecting element 25 . The sensor(s) 88 could have a built in power source or it could have a remote power source such as induction so that it would only wake up and activate when an external controller was brought near. The device 10 could have integrated memory to allow storage of patient and device 10 data. This could include but is not limited to the serial number, the patient's information such as name, patient number, height, weight; the physician's name, the adjustment history including the date and time, the amount adjustment and the sensed parameters. For the active device, there could be 24 hour data recording of key parameters or there could be data collected at key intervals throughout the day to detect when the patient is eating and whether they are being compliant with their eating. It could record weight tracking, BMI or other data as needed which could be queried by an external controller. This data could also be downloaded into a physician's patient tracking database for ease of patient tracking. Similarly, this data could be downloaded and tracked on an internet tracking website, where the patient could log on and see their history and progress. The patient could add information to the website such as weight or an eating log, adverse events or other conditions that the physician or patient would like to track. In the open system, the physician could choose to collect and record data as needed at the time of the adjustment such as weight, date, time, and adjustment amount or other. For an open loop system, the device 10 could be adapted to allow for remote adjustments over the phone. This would be especially advantageous for patients living in rural areas where they are far from their physician's office. It could also be for convenience of having an adjustment without having to travel to the physician's office. This would allow a physician to discuss the patient's progress with the patient directly and then query the device sensor 88 to see how the device performance is. Based on the feedback of the device 10 , the physician could then adjust the patient. In yet another embodiment, the device 10 could have an emitter element for dispensing a drug, hormone or bioactive agent to further induce satiety, weight management or other disease management such as diabetes. The drug could be a weight management drug currently on the market or one to be developed. Similarly, it could be a satiety hormone or other bioactive agent. In the published literature, there is a growing mass of information on satiety hormones. The bioactive agent could be applied by the emitter element through a drug eluting coating, a reservoir with a pump, or a permeable membrane placed on the device 10 where the drugs could pass from the device 10 into the gut. The emitter element could release such substances in response to a signal from a sensor 88 , a timed basis, or other release criteria. The device 10 could have a tube that trails into the intestines to allow the drug to be delivered downstream where the pH is higher and would not destroy the bioactive agent. The device 10 could have a surface finish or macrotexture for gripping the stomach. If the device 10 could grip the inner mucosa of the stomach, it could elongate or expand to further stretch the stomach in key areas to induce further satiety as needed. For example, the cardiac element 12 could be a conical spiral with a surface texture that lightly grips the mucosa and or stomach musculature. If the spiral were made of Nitinol or other temperature-sensitive substance, the device 10 could expand the spiral by a variation of temperature. By applying a temperature variation, such as by drinking a hot liquid or otherwise, the device 10 could expand and cause a satiety response. The surface could be multiple protuberances, barbs, a rough bead blast, or other finishes suitable for gripping the stomach wall. The device 10 could have a thin flexible tube 89 attached to the pyloric element 26 that could trail into the duodenum 19 to act as a barrier to food absorption. See FIG. 47 . This tube 89 would be of similar diameter to the duodenum 19 and all food passing through the pyloric element 26 would pass directly into this sleeve. Similar to the rerouting performed in a gastric bypass or Roux en Y bypass, the sleeve 89 would be approximately 100 cm long, but could be longer or shorter depending on the amount of malabsorption required. This tube 89 may be made of an acid resistant material such as Teflon, PTFE, ePTFE, FEP, silicone, elastomers or other acid resistant materials. As a variation of the device 10 , it could incorporate electrical stimulation to the stomach musculature, stomach nerves or the vagus to further improve satiety stimulation and weight loss. Energy used for this stimulation could be RF, ultrasound, microwave cryogenic, laser, light, electrical, mechanical or thermal. The device 10 could have leads incorporated that could embed into the stomach wall or be surgically placed around a nerve, or the stimulation could be applied directly through surface contact of the device 10 to the stomach mucosa. In yet another embodiment, the bariatric device 10 may have an adjustment element 60 that is equipped with a temporary expansion/contraction element that may allow for temporary adjustment based on activation of a material property, sensor 88 or mechanism of the device 10 . This could be applied to any of the above-discussed embodiments. It may be desirable for the temporary expansion/contraction element to adjust only upon eating, and then retract after eating. It may be desirable for the device 10 to adjust with the pH cycle of the patient where pH will be higher prior to eating and then lower after eating. This would allow for intermittent stimulation of the stretch receptors to avoid receptor fatigue over time. For example, the material could be heat sensitive using materials such as Nitinol, which could expand after consuming a hot liquid. Similarly, the device 10 could have a sensor 88 or material that is pH or glucose sensitive or detect the presence of food, which could activate the temporary expansion/contraction element to expand when a certain threshold for pH has been reached or glucose or fat is present after eating. Similarly, this temporary expansion/contraction element could be activated by a magnetic field such as swallowing a magnetic pill that could temporarily expand the device 10 . In this example, the magnetic pill would be small enough and shaped appropriately for passage through the gastrointestinal tract, and biocompatible. The patient could consume the electromagnetic oil when a satiety signal was desired. It may also be desirable for the device 10 to adjust based on time or sleep cycle such that the device 10 adjusts at specific times of the day or when the patient lays horizontal. Other parameters or mechanisms to trigger the temporary expansion could be used. Placement As mentioned above, a tube, catheter, or sheath may be required to protect the anatomy during placement of the device 10 down the esophagus and into the stomach. It could be a simple flexible tube such as silicone or urethane tube to aid in straightening and compressing the device 10 while it is being introduced. Insertion of the device 10 into the tube would require compression of the device 10 into a narrow, insertable shape. A standard gastroscopic tool could be used to push or pull the device 10 down the tube. Similarly, a custom gastroscopic tool or sheath could be used to introduce the device 10 into the stomach through the esophagus or other narrow opening. Removal For removal, a flexible tube such as a standard overtube could be used with a standard or custom endoscopic tool. The tube may be placed down the esophagus and the tool then placed down the lumen of the overtube. A standard tool such as a grasper or snare could grasp the device 10 and pull it up the tube. The device 10 would be straightened by the overtube for removal from the stomach and esophagus. In another embodiment, the elements may incorporate a collapsing mechanism designed to collapse the element into a compact shape for removal. For example, a constriction member comprising a wire or thread sewn spirally around, through, or inside the length of the element. When the constriction member is pulled, it tightens the circumference of the pyloric element like a drawstring, which collapses the element down to a narrow profile that can be safely removed through the esophagus or other narrow opening, or ease its placement into a tube for removal. Similar collapsing mechanisms can be installed in the cardiac, and/or connecting elements 12 , 25 . The constriction member could be made from Nitinol, stainless steel wire, ptfe thread, eptfe thread or ptfe coated threads or other suitable materials. The constriction member could be integrated into the elements in a variety of patterns such as a continuous spiral, two spirals of reversing orientation, or other. In another embodiment, the connection of the cardiac, pyloric and connecting element may be equipped with a release element, which would allow the cardiac, pyloric and/or connecting elements to be releasable, cut-able or modular, as to allow the device to be disassembled into components for ease of removal. FIGS. 48 , 49 A and 49 B show a release element in the form of a releasable clip 108 in the closed and open positions. The clip could be made of an elastomer or polymer or other, but would need adequate flexibility to allow the clip to close and then re-open. The clip has a locking tooth 109 which compresses when pulled through a narrow channel 110 , and then expands into an opening to lock the clip into position. To release the clip, the release tab 111 is pulled upward which allows the narrow channel to flex open, and the locking tooth 109 is released. FIG. 48 shows as side view of the releasable clip in the locked position in a suggested location to attach a connecting element to another element. A release element like this could be bonded or incorporated into the cardiac and pyloric elements and then could be locked around the connecting element to secure the assembly. When the device is ready for removal, standard instruments could be used as a releasing tool under the visualization of a gastroscope to release the tabs to disassemble the pyloric 26 and/or cardiac element 12 from the connecting elements 25 . Then each element or combination of elements could then be removed up the esophagus or through an over tube. As described above, the pyloric or cardiac elements could still contain a collapsing member to further collapse the element for removal. The connections could be placed over a single section of the connecting element or it could be placed over a joint to join two connecting elements. The connection length could be a short distance or it could be a relatively long distance. With a short distance, several clips could be used to join a connecting element to a cardiac or pyloric element such as shown in FIG. 50A . With a long element, one clip could feasibly connect the two elements such as shown in FIG. 50B . FIGS. 50A and 50B show an example of release elements where the modular clips could be used to connect the cardiac, pyloric and connecting elements, 12 , 25 , 26 . These are only examples of where a connection could be located, but other locations could be used. Similarly, this modular clip only shows one type of clip, but several other options could be used. The modular connection of the components could be equipped with release elements comprising many different mechanisms such as other clip designs, ties and could also provide an area where the connection is to be cut by a releasing tool, such as endoscopic scissors or electro-cauterizer, or other custom tools. In another embodiment the connecting elements could be sewn into the pyloric and cardiac elements with acid resistant thread such as ePTFE thread and/or cloth. The thread or cloth could be cut by a releasing tool such as surgical scissors or an electro-cauterizer for removal. The connection could be made of many different materials such as silicone, nitinol, polymers, super alloys, or other suitable materials that can withstand the acidic environment of the stomach. Likewise, the releasing tool could be many different endoscopic instruments. The foregoing description of the preferred embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention not be limited by this detailed description, but by the claims and the equivalents to the claims appended hereto. INDUSTRIAL APPLICABILITY This invention may be industrially applied to the development, manufacture, and use of bariatric devices for weight loss purposes.

A bariatric device for use in inducing weight loss, comprising a cardiac element, a pyloric element, and a connecting element between the two other elements, wherein the connecting element provides structure between the cardiac and pyloric elements, keeping them largely in place and at least intermittently touching and applying pressure to the stomach's cardiac, adjacent fundic and pyloric regions, respectively, which produces a satiety signal to the user, giving the recipient a feeling of fullness and reducing his or her hunger feelings. Alternatively, the cardiac and pyloric elements may be symmetrical, so that the device can orient itself either way in the stomach and still achieve the weight loss function.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional patent application of prior U.S. patent application Ser. No. 11/153,305, entitled “INSURANCE PRODUCT, RATING SYSTEM AND METHOD,” filed on Jun. 15, 2005. STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] N/A REFERENCE TO A MICROFICHE APPENDIX [0003] N/A BACKGROUND OF THE INVENTION Field of the Invention [0004] Pricing and rating methods for property and property-related asset performance insurance products can be classified into two categories: Value-based (VB) rating and Frequency-Severity (FS) rating. In both cases insurance costs are directly related to the financial loss potentials, but the computational methods reflect the characteristics of the property or assets being insured. [0005] VB rating generally is applied to situations where risk or loss potential can be characterized by a series of variables. For example, the loss potential and pricing for a new car may be determined by the car type, the type of loss (e.g., collision, liability, glass windshield) the amount and type of miles driven, the driving record of the insured, the geographical location and perhaps other variables. Given these variables, loss potentials have been analyzed and tables produced enabling the underwriter to look up the rates, expressed in dollars of premium/dollar of coverage, in tables. The underwriter typically multiplies the client-specific variables by the corresponding rates then adds in company-specific administrative costs to compute the overall policy premium. [0006] For property VB insurance, some common underwriting variables are business type, building activity (e.g., hospitals, office buildings, laboratories, etc.), square footage or other attributes of size, construction attributes, fire sprinkler coverage, number of stories, location, and age. Premium rates expressed are generally categorized by these variables and together produce a premium rate. This value multiplied by the building value produces the policy premium. Actual premium values may vary by historical precedent of pricing, market demands, policy terms and conditions, contents type and property replacement values. [0007] FS pricing is a rating and pricing method for situations where there can be large differences between insureds in the same type of industry and geographical area. In this method the probability or failure frequency (events/year) of an insurance claim or failure may be modeled or directly obtained from available data. [0008] Engineering and underwriting risk modifiers are factors applied to the loss cost computed premium that adjust for specific customer attributes present in the current situation. For example, an engineering risk modification factor to increase the loss cost 10% could be applied for clients who have poor procedures for record-keeping and plant cleanliness. Engineering inspectors have identified a high correlation with these behaviors and customers who will have insurance claims. An underwriting risk modification factor of 10% could decrease the policy premium if high deductibles and restricted coverages are negotiated with the client. These engineering and underwriting risk modification factors make detailed premium changes based on the specific attributes of the client and the policy terms and conditions. [0009] An example of the FS pricing method for a client is applied to an equipment breakdown premium development for a power generation station 100 shown in FIG. 1 . The station has two (2) simple cycle GE 7FA turbine generators 102 , 104 with two (2) transformers 106 , 108 and various types of electrical switchgear and equipment (only switch 110 is shown). The first part of the premium calculation contains the frequency and severity calculation which determines the loss cost component of the premium. There are risk modification factors that customize the loss cost component for the specific client being analyzed. These factors can increase or decrease the credit and debit percentage that allows underwriting to modify the loss cost to reflect the subjective attributes (e.g., engineering factors) of the client, for example, housekeeping, recordkeeping, reliability planning, the number of equipment spares available and underwriting factors such as the deductible value selected. [0010] The next part of the premium calculation determines the client-specific expenses, costs and profit. Another component of the premium calculation, the Excess Loss Potential refers to a loss cost premium component that accounts for the very low frequency, but very high severity loss events that are appropriate for the client. Examples of such loss events include five hundred (500) year recurrence period earthquakes, tsunamis and hurricanes. The loss event severities may be determined by specialized catastrophic modeling software. A portion of the insurance company's total loss potential may be allocated to each client as the Excess Loss Potential component of the premium. [0011] The client may also be subjected to engineering inspections associated with jurisdictional requirements of the state or other governmental bodies. The underwriting process also includes certain client-specific costs associated with meetings, travel and the like. [0012] Expenses considered in the underwriting process can also include costs for re-insurance and are usually added when the underwriter buys facultative re-insurance—re-insurance on a specific account. Although other expenses that involve a pro-ration of portfolio, line of business, department, or division expenses to the account level may also be added. Other premium costs are typically taxes, commissions to brokers, profit margin and other specified premium cost adders in the company's underwriting guidelines. [0013] The FS pricing for the example above is shown below for constructing an equipment breakdown insurance price for a simple cycle gas turbine generation facility: [0000] Annual Failure Premium Equipment Frequency Severity (Loss Costs) 2 GE 7FA turbines 0.025 $80,000,000  $2,000,000 2 Transformers 0.015 $4,000,000 $60,000 Switchgear + Electrical 0.030 $1,000,000 $30,000 Total Loss Costs: $2,090,000 Engineering/Underwriting Modifier (+20% − 15%) [−10%] $1,881,000 Excess Loss Potential: $100,000 Engineering Expenses $25,000 Underwriting Expenses $10,000 Allocated Expenses $300,000 Taxes, Commissions $30,000 Profit (5%) $115,000 Total Policy Premium: $2,461,000 [0014] Policy rating and pricing applied to property-related insurance pricing generally is a combination of applying the VB and FS methods. The insured's (client) property often contains a mix of highly specific equipment and other activities that are common to many similar types of locations. A client's power generation company may own a small number of highly specialized power generation locations that are rated and priced using FS but also has several branch offices where the premium may be computed by the VB method. BRIEF SUMMARY OF THE INVENTION [0015] The present invention referred to herein as the insurance product, rating system and method generally relates to a rating and pricing system for quantifying the risk that the annual savings will not fall below specified levels associated with implementing and maintaining economic improvements. The invention typically involves a unique combination of qualitative and quantitative functions and factors combined in a novel fashion to develop premium costs for risk transfer associated with insuring a minimum savings amount annually or in aggregate over a multi-year policy term. [0016] Insurance pricing systems where there may be a large amount of exposure and loss data available use standard statistical and probabilistic methods. Policies are often standardized in format and simplified to the point where underwriters construct premiums from tables where the risk attributes such as insured's age, car type, location, or building values are the key elements used to lookup the appropriate rates. Other insurance policies, such as for property insurance, may include a premium component developed from catastrophe models which estimate losses from earthquakes, for example. [0017] Insurance pricing systems are normally designed for products which are marketed to a large number of customers usually on an annual basis, each with a relatively small loss potential. The present invention comprises an insurance product rating and pricing system designed for a relatively small number of insureds annually or over a multi-year term with each insured having a relatively large exposure. This situation cannot rely on the Law of Large Numbers principle of statistics but applies as much knowledge and actual performance data as possible into the development of the risk analysis and subsequently the premium development. [0018] The insurance policy rating and pricing system according to the present invention may generally be based on a risk analysis where actual performance data, technical uncertainties, and other factors are combined to form input information for the pricing system. The input files, called annual aggregate risk distributions, quantify the net performance risk of all initiatives for achieving the net annual savings for each year of the policy period. For example, an improvement program may consist of work force reassignments, process re-designs, installation of advanced process controls, and energy efficiency capital projects. However, this invention is not so limited. As a further example, it also applies to other methods capable of quantifying the total net annual savings risk of potentially several hundred initiatives. These risk distributions quantify the probability of exceeding a given net annual savings value and serve as the fundamental input files, data, or equations according to the present invention. The present invention enables underwriters to apply similar procedures they would perform in standard insurance situations even though the nature of the insured risk is unique. [0019] According to the present invention, “Savings” can be tangible or intangible and include but are not limited to increased revenue; reduced operational expenses maintenance expenses and capital expenditures; increased production through-put; reduced energy consumption; reduced emissions; increased emission credits; etc. These savings will produce additional benefits to the client in the form of enhanced creditworthiness and resulting increased availability of financing and reduced cost of financing. One skilled in the art will recognize that the present invention can generate other savings and benefits not articulated in the lists above. [0020] The aggregate risk distributions are defined for each location on a similar basis as that applied to develop property insurance. Underwriting may be first performed at a location level and then viewed at the client level. One novel part of this invention is to enable the underwriter to develop pricing at either level. At the location level, the aggregate risk distributions are formed for the subset of all initiatives designed to be implemented at the location. At the client level, the aggregation produces only one aggregate risk distribution per year or other time periods. [0021] If location level pricing is desired, then according to the present invention, aggregate risk distributions are applied at each location and the client level premium may be equal to the summation of the location level premiums. Some premium components may appear only at the client level, such as profit, tax, and commissions, but the system and method according to the present invention contains the flexibility to include all pricing elements in either version of the application of this insurance pricing system. [0022] While the invention is generally discussed from the perspective of either pricing a single location or pricing at a single client level, a multi-client pricing system is also within the scope of the present invention. Multi-client as used herein includes but is not limited to an investor(s) in one or more facilities, for example power, refining, chemical, manufacturing facilities, etc. in any permutation or combination of ownership and/or geography. BRIEF DESCRIPTION OF THE DRAWINGS [0023] A better understanding of the present invention can be obtained when the following detailed description of the preferred embodiment is considered in conjunction with the following drawings, in which: [0024] FIG. 1 is a block diagram of a power generation station. [0025] FIG. 2 is a flowchart of an embodiment of the claimed product, system and method. [0026] FIG. 3 is a flowchart of an embodiment of the claimed product, system and method. [0027] FIG. 4 is a flowchart of an embodiment of the claimed product, system and method. [0028] FIG. 5A is a flowchart of an embodiment of the claimed product, system and method. [0029] FIG. 5B is a flowchart of an embodiment of the claimed product, system and method. [0030] FIG. 6A is a flowchart of an embodiment of the claimed product, system and method. [0031] FIG. 6B is a flowchart of an embodiment of the claimed product, system and method. [0032] FIG. 7A is a spreadsheet of an embodiment of the claimed product, system and method. [0033] FIG. 7B is a spreadsheet of an embodiment of the claimed product, system and method. [0034] FIG. 8 is a flowchart of an embodiment of the claimed product, system and method. [0035] FIG. 8A is a table of an embodiment of the claimed product, system and method. [0036] FIG. 8B is a chart of an embodiment of the claimed product, system and method. [0037] FIG. 8C is a chart of an embodiment of the claimed product, system and method. [0038] FIG. 9 is a chart of an embodiment of the claimed product, system and method. [0039] FIG. 10 is a system block diagram of one embodiment of the claimed product, system and method. [0040] FIG. 11 is a block diagram of an insurance policy according to the claimed product, system and method. [0041] FIGS. 12A-12D are tables of an embodiment of the claimed product, system and method. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0042] The underwriter first determines the insured floor dollar values for each year as shown in step 200 in FIG. 2 . This may be performed by specifying a confidence level that is used to return the indicated or computed minimum insured savings values for all years or confidence levels and can be applied on a year by year basis. Selecting insured floors by first specifying an explicit confidence level is one unique characteristic of this invention. For this invention, “confidence level” is defined as the probability that the annual savings will exceed the insured floor value. Performing this function is called risk acceptance. For each policy year, the underwriters select the risk acceptance level they believe represent insurable positions under the terms and conditions of the policy at step 202 . The insured floors are also called risk acceptance thresholds in that if the insured's annual Savings results are below these values and the insured is in compliance with the terms and conditions of the policy, the insurer would pay the insured the difference between the actual achieved results and the insured floor value at steps 204 and 206 , respectively. Under the insurance policy, the insurer is accepting the risk of paying up to the risk acceptance threshold dollar amount each year. [0043] These risk acceptance values are also related to claim frequency as depicted in FIG. 3 . The method starts at step 300 where a confidence level percentage is determined at step 302 . The difference between 100 percent and the confidence level percentage constitutes the probability that the Savings may be less than the risk acceptance value at step 304 . For example, a 90% confidence level indicates that 10% of the time, the Savings is expected to be less than the indicated acceptance value. While additional claim frequency mitigation elements are applied in this invention, the 100 minus confidence level may be an upper limit on the expected annual claim frequency. [0044] Another unique characteristic of this invention is to use the confidence level approach to enable underwriters to apply different risk acceptance judgments for different policy years. This may be but one major advantage of setting deductibles by confidence level rather than directly in terms of absolute dollar values. However, underwriters can choose a risk acceptance value directly and apply the input annual aggregate risk distributions to determine the corresponding risk acceptance confidence level. Both methods are included in this invention. Also the application of input annual aggregate risk distributions to help specify multi-year deductibles is a unique part of this invention. [0045] The flexibility of specifying yearly or overall confidence values enable underwriters to set risk acceptance values higher for years they believe there is higher risk and lower amounts when the risk is within normal tolerances. This can occur if the underwriters believe that the insured's implementation and scheduling plan will not either meet the expected Savings targets or that the project schedule is too aggressive implying that the insured's Savings will be achieved but not in the policy year indicated in the implementation and scheduling plan. This feature gives underwriters the flexibility to adapt their risk acceptance analysis to consider in addition to the insured's engineering performance, the available personnel, project management, and several other key factors. [0046] As an example of how this process can be performed, suppose a potential insured's cumulative Savings engineering project plan forecasts $20M in year 1 , $30M in year 2 , and $35M in year 3 as depicted in step 400 of FIG. 4 . After a detailed review of the implementation and scheduling plan by underwriting, the completion schedule for the year 1 is judged to be too optimistic. Underwriters believe that the Savings as forecast by year 1 will be obtained but some of the initiatives will extend into year 2 . For the remaining initiatives, it is further concluded that the Savings targets will be achieved on the time schedule indicated in the implementation and scheduling plan for years 2 and 3 . [0047] For this situation underwriters may apply a higher confidence level for year 1 than for years 2 and 3 at step 402 . A 95% confidence level could be applied to year 1 with a 90% confidence applied to years 2 and 3 . The resulting risk acceptance values may be $10M for year 1 , $22M for year 2 , and $25M for year 3 . It may be expected that the risk acceptance values will be less than the stated engineering forecasts as a matter of proper underwriting, for example, to reduce the potential for moral hazard. [0048] With the risk acceptance values selected, the next underwriting decision is to choose the confidence level associated with the loss cost analysis at step 404 . For example if an underwriter chooses a 95% confidence level, the corresponding loss costs actually experienced should be less than this value 95% of the time. A unique characteristic of this invention is the capability of the underwriter to select a loss cost confidence level by year or, by default, use the same value for all years. [0049] Another unique characteristic of this invention is the ability to apply different savings measurement criteria as claim triggers. One embodiment of the invention contains two types of savings measurement criteria although a combination or other methods could be applied. [0050] The underwriter selects the measurement method and for this example of the invention, the methods are Escrow or No Escrow. The Escrow approach accumulates the excess above the risk acceptance values, if any, in the Savings over the policy years. If there is a shortfall in a policy year, the Escrow account may be debited first. A claim occurs when the Escrow account is zero and a yearly savings target is not achieved. The No Escrow method simple compares the actually achieved value, A, to insured Savings value, B, and a claim for the dollar difference $B−A occurs if A<B. [0051] While the underwriter selects the measurement method in the system, it is not necessarily an input that is determined by the underwriting function. The claim measurement method may be identified as part of the policy and may be agreed to by the insured, insurer, and other interested parties such as investment firms, banks, or rating agencies (e.g., Standards & Poor). [0052] At this point, FIGS. 5A and 5B illustrate the system for computing loss costs using a stochastic model that utilized the input annual aggregate risk distributions, risk acceptance values, the claims measurement method, and the required loss cost confidence level shown at steps 500 and 502 . This is a dynamic system where at any one of these inputs change, the stochastic model is re-run at step 504 . This combination of these policy-specific attributes and risk data to produce loss costs is a unique characteristic of this invention. [0053] At the completion of the stochastic analysis which may require several thousands of different samples to accumulate the sufficient loss cost distributions, the loss costs at the underwriter specified levels is automatically placed into the pricing worksheet at step 506 . The values are summed over the years of the policy term (e.g., over a range of one to seven years) at step 508 and compared with a company-specific requirement of a minimum rate-on-line at step 510 . Rate-on-line is defined as the loss costs (or premium) divided by the total dollar exposure to the insurer. For example, a 5% rate-on-line requirement for a $1M total exposure produced a premium result of $50,000. The maximum of these two numbers: the sum of the loss cost values from the stochastic model and the rate-on-line estimated premium, is entered as the loss cost component of the multi-year policy premium at step 512 . [0054] With the loss costs determined, the underwriter adds premium charges that are due to the engineering and underwriting fees that will be required to administrate the policy over the policy term at step 514 . These expenses include for example, on-site engineering review of work practices, initiative implementation progress, and the Savings measurement and verification procedures. These activities will generally vary according to the type of industry, facility location, policy term, policy conditions, and with several other factors. It is noted that the premium reflects the true costs of policy administration as well as the potential costs involved with actual losses. These costs are entered individually for each policy year, inflated using a supplied annual inflation rate, and summed to produce the overall engineering and underwriting (insurance) components at step 516 . These costs are mostly well defined expenses and are not typically risk-based nor do they possess a significant stochastic component. At this point in the premium development, these charges are placed into the year and category (Underwriting or Engineering). Additional analysis of factors that influence the loss cost premium component is generally required before the expense items can be used further. [0055] Along with the quantitative aspects of underwriting and premium development, there are subjective factors that are designed to utilize the underwriter's intuition and experience to modify, if desired, the computed loss cost premium at step 518 . These factors can increase or decrease the loss cost component within prescribed percentage ranges. To facilitate the underwriter's use of these subjective factors, they are divided into engineering and underwriting categories. The actual list of risk modification factors and ranges will vary between industries and clients but they may include some of the items listed below. [0056] A credit is interpreted as enhancing risk quality which then translates into a decrease the loss costs. A debit is configured as a decrease in risk quality which increases the loss cost component of the policy premium. Engineering Quality Underwriting: [Debits, Credits] [0057] 1) Organization/Culture: [+15%, −10%] Risk exposures, hazards, and human behaviors are inter-connected. A company's safety, environmental, reliability policies and basic cultural risk acceptance attitudes are important attributes for inferring how the corporation and its employees will routinely mitigate risk and also respond to accidents [0058] 2) New Technology Applications: [+10%, −10%] Depending on the robustness of the new technology design, the operational and short term financial advantages can be offset by a decrease on reliability and availability in the long term. These factors need to be considered by the underwriter in this multiyear type of insurance policy which is intended to insure a minimum performance or Savings level. [0059] 3) Management Motivation: [+15%, −10%]. The underwriter needs to understand how the company's management intends to leverage the financial applications of the overall implementation and scheduling plan. The multi-year program will require the long term commitment of management and the financial applications of the program will provide the underwriter valuable insights to judge the Savings sustainability. [0060] 4) Supervisor Motivation: [+15%, −10%] The underwriting risk assessment for facility supervisors may be similar to what may be required for management. At the employee-level, supervisors need to be committed to the implementation and scheduling plan's success and to its sustainability over the multi-year policy term. One way for the underwriter to assess supervisor (and management) commitment may be to determine how the execution of the Savings implementation and scheduling plan is connected to the employee bonus program. [0061] 5) Complexity: [+10%, −10%] Complexity refers to the difficulty of program execution. Some of the issues to be considered in this evaluation are initiative technical difficulty, volumetric inter-dependence, and schedule inter-dependence. [0062] 6) Housekeeping and Recordkeeping: [+5, −5%] The cleanliness, arrangement, and organization of the insured's assets are valuable, observable indicators to infer employee reliability and safety awareness. Many studies have shown a strong productivity and reliability correlations to facility and asset cleanliness and organization. This characteristic may be easy to observe and inference to improved reliability may be a factor in the engineering aspects of policy underwriting. Also the level and accuracy of production and operational recordkeeping may be another visible indication of employees' and management's commitment to procedure compliance and attention to detail that also reflects the engineering risk quality of the insured's facilities. [0063] Overall the summation of the debits and credits of one embodiment is generally limited to a total of a 20% credit (premium decrease) or a 25% debit (premium increase.) [0064] Underwriting quality refers to the terms and conditions of the insurance policy that are negotiated given the operational and engineering conditions of the implementation and scheduling plan. These risk modification factors measure risk quality from a written contractual, rather than technical, perspective. [0065] The credit and debit assignments follow the same convention as with the engineering risk modification factors. A credit is interpreted as enhancing risk quality which then translates into a loss cost reduction. A debit is configured as a decrease in risk quality which is expressed as an increase the loss cost component of the policy premium. Underwriting Quality Underwriting: [Debits, Credits] [0066] 1) Exclusions: [+10%, −10%] These policy terms refer to events for which the insurance policy would not respond to Savings achievement levels below the insured minimum. These events include, war, worker strikes, weather events, events covered under other insurances, failure of the insured to comply with policy conditions, and contractor performance errors. [0067] 2) Self insured retention/Deductibles: (+10%, −10%] The self insured retention or deductibles determine the insured's total financial risk exposure. If the insured is willing to assume higher annual Savings levels, then the risk quality from an underwriting perspective can be increased since the insured accepts a larger annual Savings shortfall before the insurance policy would respond. [0068] 3) Savings Measurement & Verification: [+15%, −10%] The type of Savings and the procedures for measurement verification are fundamental to insurance underwriting. These factors are essential to determine initiative implementation quality both in time and volumetric savings achievement. There are, however, different ways these functions can be accomplished. For example, the measurement and verification can be performed by the insured and audited by the insurer, or a third party can be charged with these tasks. Involving the insured in these actions can be problematic and provide a moral hazard if insufficient oversight is not maintained. Savings measurement and verification can also provide a proactive indication of initiatives which are behind implementation targets. The underwriter needs to assess the type of measurements being taken to measure the Savings, the frequency of measurement, the ability to access this data trending, and the propensity to obfuscate actual initiative performance. [0069] Overall the summation of the debits and credits are limited to a total of a 20% credit (premium decrease) or a 25% debit (premium increase.) [0070] The aforementioned factors are routinely applied in policy underwriting and premium development depending on the type of insurance, life, casualty, property, etc. and also on the nature of the insured's business. The actual number and type of Engineering and Underwriting risk modification factors will vary depending on the type and nature of asset performance under policy consideration. [0071] The “Adjusted Premium” is now computed at step 520 . This term is defined as the aggregate policy term loss costs multiplied by the Engineering and Underwriting risk modification factors. If E=the aggregate engineering risk modification factor, U=the aggregate underwriting risk modification factor, and L the loss costs, then the adjusted premium, P adj is determined by [0000] P adj =(1+ E+U )* L [0072] The final stage of the premium development is to add premium components associated with insurance pricing elements at step 522 . These items typically include engineering & administrative expenses, profit, reinsurance costs, taxes and commissions. [0073] There are several variations and combinations of these factors that can be applied to the insurance product, rating system and method. The most notable variation may be the decision on how to account for the engineering expenses. Some insurance policies of the present invention may include all engineering fees in the policy premium and some may exclude the charges from the policy premium and charge these fees as consulting expenses independent of the insurance policy. [0074] As an example of how the insurance policy pricing according to the present invention is performed, the following example shows premium development according to the present invention for a three year policy where engineering fees are incorporated into the premium calculation and is used to develop the loss costs. [0075] An embodiment of the overall claimed subject matter follows in FIGS. 6A and 6B . [0076] 600 Input Basic Client data into system. At step 600 , the user enters: Insured Name, Lending Institution, Country & Region, Addresses of Covered Locations, Occupancy, Location Size in Production Output Metrics, and Application of Insured Savings. This basic data can be integrated with a client database so that other key variables required by the system can be automatically identified from this basic data. [0077] 610 Develop the numerical or analytical distributions of Savings by year. At this step an overall annual probability distributions are compiled and placed in a format so they can be accessed dynamically. The distributions describe the probability of exceeding annual Savings vs. the savings values. The distributions can be taken by analytical methods designed to compute aggregate Savings exceedance probabilities. There is a separate distribution for each location, plant, unit, or other segment under analysis for each year. These distributions are composed of Savings values and the corresponding probability of exceeding these values. [0078] 620 Enter Market and Company Pricing Criteria Data. At this step, the inflation rate that is representative for the policy period and the minimum and maximum rate-on-line company-specified criteria are entered into the system. [0079] 630 Choose the probability of exceedance thresholds to be used to set the insured floors: the insured savings levels by year, by location, or by other groupings. At this step the amount of risk that the insurer is willing to accept is determined by setting the exceedance probability threshold for coverage. There are two ways this can be done, the user can choose a probability of exceedance for all years or a different value for each year depending on the underwriting information. The probabilities are matched in the probability distributions compiled on step 610 and the corresponding Savings values are identified. For example, suppose the insurer is willing to accept an exceedance probability (measured in percentage) of 90% for a given location for a given year. This value is matched to the appropriate probability distribution discussed in step 610 and the corresponding Savings value is found to be $15M. This means there is a 90% chance that the location's annual savings that year will be greater than $15M. An insurance claim may be triggered if the annual savings achieved is less than the $15M value. [0080] 640 Record the Savings levels by year, location, or other grouping in the loss cost component of the pricing development system. At this step, the resulting Savings values that are calculated or accessed from the probability distributions compiled in step 610 , are entered into the loss cost component of the pricing system. These values are the resulting insured levels that correspond to the probability of exceedance values entered into the system in step 630 . [0081] 650 Develop logic to test annual Savings results selected from the annual probability distributions compiled in step 610 to measure loss and excess event frequency and severity. At this step for each year or other grouping, the logic is developed to compare a sampled distribution Savings value from the probability distributions compiled in step 610 to the recorded values savings floor Savings values. If the sampled Savings value is greater than the inured floor, then an excess is produced for that year. If the value is less than the insured level as given in step 640 , then a loss event is produced for that year. [0082] 660 Develop escrow account and claim trigger logic. At this step, the comparison logic developed to accumulate the total or a fraction of the Savings results that are in excess of the insured savings values. For example, in one year if the computed Savings is $50 and the insured floor is $40, $10 would be credited to the escrow account. On the other hand, if the computed Savings was $35, then first the Escrow account would be debited $5 to obtain the insured level. If the escrow account contained insufficient funds then an insurance claim would be triggered for the difference between the insured level and the sum of the actual Savings results and any funds able to be drawn from the escrow account. [0083] 670 Develop claim count, claim amount and claim risk distribution logic. At this step, logic is developed to accumulate the number and financial amount of claims for both the escrow and no escrow accounting methods. The financial amount of the claims is called the loss costs. This information is used to compute numerical distributions for the cumulative probability of loss as a function of the loss amount. These distributions are called claim risk distributions. [0084] 680 Run stochastic model to develop claim risk distributions. At the step, a numerical procedure is applied using commercial software or specialized programming that applies steps 640 , 650 , and 660 to accumulate sufficient loss data to develop a numerical distribution of the probability of loss as a function of the loss amount for both the escrow and no escrow accounting approaches. [0085] 690 Determine Rate-on-Line premium. At this step, the prescribed rate-on-line criteria selected in step 620 is applied to each annual exceedance threshold selected in step 640 . The rate-on-line premium calculation may be performed by multiplying the exceedance threshold, the insured Savings minimum, or floor by the decimal value of the rate-on-line. For example, if the insured floor is $10,000 and the rate-on-line is 10%, then the premium requirement is $10,000*0.10 or $1,000. These calculations are applied to each insured annual savings floor as computed in step 640 . The results are summed and placed in a Term of Loss Cost Summary Section of the system. [0086] 700 Determine loss cost confidence level and loss cost values. At this step the underwriter enters the likelihood requirement, in percent, that the loss costs obtained from the system will be actually less than the identified values. These percentages are then applied to the claim risk cumulative distributions for each year to determine corresponding value for the yearly loss costs contribution to the total multi-year premium. The resultant values are placed in the yearly loss cost fields. This is performed for the claim risk distributions with and without escrow accounting. [0087] 710 Compute Loss Cost Policy Premium Component. At this step, the rate-on-line premium values for each year are summed to compute the total policy premium via the rate-on-line method. Next, the annual loss costs determined in step 680 are summed over the policy years for the Escrow and No Escrow pricing methods. The system user then selects which Escrow pricing method may be required for the client. The system subsequently computes the policy loss cost premium component as the maximum of (1) prescribed rate-on-line, and (2) the summed loss costs via the Escrow method selected. [0088] 720 Determine Underwriting Expenses. At this step, the company expenses, required to perform the underwriting analysis and risk surveillance are entered. These costs are incurred in reviewing monthly, quarterly, and yearly Savings reports and periodically meeting with client management at the client sites. The underwriters' responsibility is to ensure the client is meeting their contractual responsibilities and the Savings targets. If the client is in compliance then coverage continues as defined in the policy. If the client is not in compliance, then it is the underwriters' responsibility to notify company engineering and notify client management, in writing. If compliance with engineering recommendations and other policy conditions are not met in the time constraints as specified in the policy, then the underwriters have the responsibility and the authority to terminate insurance coverage. The expenses incurred performing these activities are entered into the system for each policy year. [0089] 730 Determine Engineering Expenses. At this step the technical engineering, project management, and Savings oversight activities are reviewed for compiling their associated policy expense costs. Engineering activities provides technical data to support underwriting activities, provides periodic loss prevention and Savings reporting, provides technical directions for initiative implementation, and serves as the on-site liaison between the insurer and the insured. The expenses incurred performing these activities are entered into the system for each policy year. [0090] 740 Determine Engineering Related Underwriting Credits and Debits. At this step, pricing modification factors are determined that increase or decrease the premium based on engineering related attributes of the Savings implementation insured values as selected in step 620 . These factors include, but are not limited to, the insured's organization and business culture, new technology applications, management motivation to achieve the Savings targets, supervisor motivation, and plant complexity. The range of the modifiers will vary with application but generally are 10% for each factor with an aggregate factor of no less than −20% and no greater than +25%. The engineering risk modification factors are entered into the system for each policy year and an aggregate modification factor is computed. [0091] 750 Determine Underwriting related Credits and Debits. At this step, the pricing modification factors are determined that increase or decrease the premium based on the underwriting related attributes of the Savings insured values as selected in step 620 . These risk modification factors include, but are not limited to, policy exclusions that are in place, the insured self insured retention, deductibles, limits, and the Savings measurement and verification program quality. The range of the modifiers will vary with application but generally are 10% for each factor with an aggregate factor of no less than −20% and no greater than +25%. The underwriting premium modification factors are entered into the system for each policy year and an aggregate modification factor is computed. [0092] 760 Compute Adjusted Policy Premium. At this step, the numerical results determined in previous steps are combined to produce the basic policy premium. There are several versions or combinations of the steps outlined in this procedure that are claims. An example of one such embodiment is: [0093] Adjusted Policy Premium=Step 710 (Loss Cost Policy Premium)*[1+Step 740 Engineering Modification Factors)+Step 750 Underwriting Modification Factors)]. This result is stored in the Premium: Insurance Adjusted Premium Section of the system. [0094] 770 Compute Policy Underwriting and Engineering Expenses. At this step the underwriting expenses determined in step 720 and the engineering expenses determined in step 730 are inflated using the inflation rate entered into the system in step 620 over the policy term and summed to compute the total policy level underwriting and engineering expenses. These results are stored in the Premium: Insurance and Engineering Expense Sections of the system. [0095] 780 Compute Engineering and Underwriting Profit. At this step, company-specific guidelines are applied to compute insurance and engineering profit based on the expenses computed in steps 760 and 770 . These results are stored in the Premium: Profit-Insurance and Engineering Sections. [0096] 790 Compute Allocated Reinsurance Costs. At this step, reinsurance costs, whether facultative or treaty related, are entered into the Reinsurance section of the system. [0097] 800 Compute Taxes. At this step, taxes are computed on the pertinent sections of the Premium Section of the system and entered in the system in the Premium-Insurance and Premium and Engineering: Taxes Section. [0098] 810 Compute Commissions. At this step insurance related commissions are computed on the pertinent sections of the Premium Section of the system and entered in the system in the Premium-Insurance: Commissions Section. [0099] 820 Compute Total Policy Engineering Costs. At this step, all premium costs entered into the Premium-Engineering related sections are summed to compute the total policy engineering costs. [0100] 830 Compute Total Policy Premium. At this step, all premium costs entered into the Premium-Insurance related sections are summed to compute the total policy premium. Also, based on the policy requirements and the pertinent accounting procedures, the total policy premium can also include the total engineering costs. In this scenario, all risk transfer and direct engineering costs required to support the policy are included in the total policy premium which is divided by the policy term to determine the annual premium. Depending on the insurance conditions, the insured may pay the whole premium at the beginning of the policy term or pay on an annualized basis. [0101] FIGS. 7A and 7B depicts a spreadsheet encompassing the steps disclosed in FIG. 6 . [0102] The methods disclosed above can be used to ascertain a securitization rating VB and FS ratings can be based on benchmark data for a particular asset, e.g. the power generation station of FIG. 1 . [0103] For example, FIG. 8 illustrates such method. Engineering data such as improving yields 940 or other initiatives 950 , both depicted in FIG. 8A is collected for each required asset at step 900 . The engineering data is compared with benchmark data to create an action plan and financial goals at steps 910 and 920 . FIG. 8B illustrates an exemplary action plan while FIG. 8C illustrates the financial goals. [0104] For example, FIG. 8B includes various actions to be initiated by employees 960 , such as detailed process evaluation 970 and train operators 980 . FIG. 8C shows how the risk curves can be used to select annual insurance levels and also provide information to select financial goals for the improvement program overall. For example, following general insurance company guidelines, a company chooses the 90% exceedance probability and moves horizontally over until we cross the Year # 1 risk curve at 990 where at 90% risk acceptance value for insurance purposes is $20M at 995 . This typically means there is a 90% chance that the actual result will be greater than $20M. The company can also use these risk curves to set their internal financial goals at more aggressive risk acceptance values. For example, company management may target the 60 or 70% levels for the business unit targets which for year # 1 would be a goal between approximately $22-$25M. The same procedure is applied for Year # 2 . The insurance risk acceptance percentile intersects the risk acceptance curve at 1000 which corresponds to $26.7M NCM annual savings at 1005 . This amount would be selected as the insured floor. For the company's internal financial goals, using the 60-70% guidelines as in Year # 1 , Year # 2 company financial goals would be between $28-29$M. A securitization rating can be ascertained based on the action plan and financial goals at step 930 ( FIG. 8 ). [0105] Implementation of the present invention may also improve an insured's bond rating. FIG. 9 illustrates cost savings as a result of a reduction of credit risk. For example, suppose improving the operations utilizing the present method can increase the Savings by $700 million of an insured over a ten (10) year period. In the course of developing this company's credit risk for the purpose of developing a bond issue, the lending institution and or credit agency involved may give the company credit for the enhanced operational and financial status by applying the margin benefit to the reduction of the principal at risk. This may be a subjective decision. However, the method applied to this situation offers a risk transfer of principal from the client to the insurer thereby securitizing at least a portion of the principal. Suppose the client has a credit rating of BB- by S & P. A policy utilizing the present invention for this client can have effect to reduce the principal at risk thereby also reducing the transaction's credit risk. Through the risk transfer of this principal to the insurance company, the initial transaction (now at effectively a lower principal) can have an equivalent credit risk of the full bond amount at a higher quality credit rating. [0106] For example, if a client has an $600M policy according to the present invention for over the ten (10) years of a $800M bond, the reduced effective principal at risk ($200) make the transaction appears, from a credit risk perspective as slightly above investment grade, BBB-. This means mathematically the credit risk of a $200 BB- bond may be roughly equivalent to the credit risk of an $800M bond rated at BBB-. This situation illustrated at 1010 in FIG. 9 . This example assumes the insurance company's credit rating is at least BBB-. [0107] Referring to FIG. 10 , a computer system used to implement some or all of the method and system is illustrated. The computer system consists of a microprocessor-based system 1100 that contains system memory 1110 to perform the numerical computations. Video and storage controllers 1120 enable the operation of the display 1130 , floppy disk units 1140 , internal/external disk drives 1150 , internal CD/DVDs 1160 , tape units 1170 , and other types of electronic storage media 1180 . These storage media 1180 are used to enter the risk distributions to the system, store the numerical risk results, store the calculation reports, and store the system-produced pricing worksheets. The risk distributions can be entered in spreadsheet formats using, e.g., Microsoft Excel. The risk calculations are generally performed using Monte Carlo simulations either by custom-made programs designed for company-specific system implementations or using commercially available software that is compatible with Excel. The system can also interface with proprietary external storage media 1210 to link with other insurance databases to automatically enter specified fields to the pricing worksheet, such as client name, location address, location size, location occupancy, and risk quality attributes applied in the “Credits and Debits” section. The output devices include telecommunication devices 1190 (e.g., a modem) to transmit pricing worksheets and other system produced reports via an intranet or the Internet to management or other underwriting personnel, printers 1200 , and electronic storage media similar to those mentioned as input device 1180 which can be used to store pricing results on proprietary insurance databases or other files and formats. [0108] FIG. 11 is a block diagram that depicts the terms and conditions of an insurance policy 1300 according to the present invention. The insurance policy 1300 includes insured information 1310 such as a name of the insured, geographic or physical location(s) of the insured to be covered by the policy. Also included in the policy 1300 is a policy period 1320 . The policy period 1320 can be over a single year, multi-year or some other defined period of time. Policy terms 1330 , such as savings criteria is included. The savings criteria are generally crafted by a third party company (e.g., HSB Solomon Associates) that uses benchmark information in creating the savings criteria based on the particulars of the insured's business. The savings criteria include processes that if implemented by the insured establishes a sum certain savings to the insured. The third party company can serve as a facilitator in process execution enabling the insured to improve operating performance (resulting in a savings). If the process is implemented and the sum certain savings is not realized by the insured over the policy term (with certain exceptions outlined in the policy), the insurer will pay the insured the difference (referred to as a shortfall). The certain exceptions include, but are not limited to, hostile or warlike action, insurrection, rebellion, civil war, nuclear reaction or radiation, default or insolvency of the insured, vandalism, riot, failure of contractors to implement the processes, modification or alteration to the processes that were not approved by the insurer or other terms outlined in the policy. Other policy terms 1330 include duties of the insurer and duties of the insured such as execution of the processes in a timely manner, cooperation with the third party company, preparation of status reports, permission by others to audit the insured's accounts, performance records and data logs and other matters. Furthermore, if the savings are determined on a yearly basis and the policy is a multi-year policy, and as a result of the insured implantation of the processes, a shortfall occurs, such shortfall could be kept in an escrow account (herein referred to as a surplus account). The escrow could increase or decrease over the multi-year policy. Any surplus at the end of the policy term can be paid to the insured. Other terms can include cancellation terms, representations and warranty, assignment obligations and effects due to the sale or transfer of a covered location. [0109] The policy 1300 also includes monetary policy limits (i.e. limit of liability) 1340 over the time period 1320 and premiums 1350 to be paid by the insured and endorsements 1360 . Such endorsements can include market price indexing and operational baselines unique to the insured's industry, the implementation plan and schedule, agreed metric plan, savings calculation procedures and baseline values, debt obligations and additional exclusions, definitions and conditions. [0110] FIGS. 12A-12D illustrate an agreed metric plan. The agreed metric plan provides top level task lists of an implementation plan and schedule. For illustrative purposes, the plan is divided into four sections, namely, initiative 1400 , benefits and measurements 1402 , implementation 1404 , and savings 1406 . [0111] For example, in FIGS. 12A , 12 B, 12 C and 12 D, the agreed metric plan pertains to a chemical industry policy. From the implementation plan and schedule, various top level initiatives 1400 are listed in FIG. 12A . For example, some of the initiatives from a chemical industry policy may include movement of an analyzer to trays and modification of regulatory controls on final product columns 1408 for a particular plant 1410 (Initiative # 1 ). The column titled “area” refers to geographical or functional location the initiative, e.g., Plant 1 . Another initiative for an insured's site may include the reduction of pressure in a stripper to save energy 1412 (Initiative # 2 ). Furthermore, another initiative for another plant may include the reduction of time to dry catalyst after regeneration 1414 (Initiative # 3 ). Documents or other deliverables 1418 are provided to document the results of the implantation of the initiatives. An example of such a document 1420 may include a report describing the savings achievement as a result of the implantation of initiative # 3 . [0112] One embodiment of the benefits and measurement section of the agreed metric plan is provided in FIG. 12B . Implementation of the initiative may result in certain benefits that are described in this section. For example, for initiative # 1 , one benefit 1422 may be a production efficiency improvement. The plan includes various measurement values and methodologies that are directed to the results of the initiative. The values and methodologies may relate to engineering units (e.g., t/h) and time periods (e.g., measurements are done daily and then averaged over a period). Furthermore, the plan includes dates (target and actual) for the commencement of the initiatives and completion dates of the initiatives. The agreed metric plan typically requires the agreement and sign off (e.g., initials of the insured and insurer) 1424 of each initiative and initiative results (i.e., the agreement section). [0113] The plan also includes target and actual dates as shown in FIG. 12C . Each initiative may have a target date of completion 1426 , actual date of completion 1428 and the number of days for completion 1430 . [0114] The plan also include information regarding the economic Savings 1432 as a result of the implantation of the initiatives. Such information may include target Savings 1434 and actual Savings 1436 achieved as a result of the initiative. [0115] The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the details of the illustrated method may be made without departing from the spirit of the invention.

In the present invention, an insurance product, rating system and method generally relates to a rating and pricing system for quantifying the risk that the annual savings will not fall below specified levels associated with implementing and maintaining economic improvements. The product, system and method can be applied to various industries, including, power generation, petro-chemical, manufacturing and refining facilities. Various embodiments disclosed herein relate to a method for pricing an insurance policy for insuring a minimum level of return on investment.

RELATED APPLICATIONS This application is a continuation-in-part of co-pending application Ser. No. 11/469,654 filed Sep. 1, 2006. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a cable arrangement and more particularly to a three-way cable arrangement for connecting a music/video source to a karaoke system and a television. 2. Description of the Related Art Cable arrangements are well known in the industry. Most cable arrangements are point-to-point, connecting two devices. Some cable arrangements are three-way, often called a Y-connector. These arrangements connect one or more input connectors from a source to the same output connectors for multiple sink devices. For example, a stereo audio Y-cable arrangement can connect the audio outputs of a DVD player to both the inputs of an amplifier and the inputs of a VCR, simultaneously. Likewise, karaoke devices are well known in the industry. Generally, these devices include a source of music and lyrics that are played/displayed while the user(s) sing along. Early karaoke devices included a magnetic tape or compact disc with music recorded thereon. The music recorded is without vocal sound track or the vocal track is significantly muted so that the user can sing along with the music. A professional karaoke system includes a source of music and lyrics, one or more microphones, a sound processing/amplification system for enhancing the user's voice and a display system for displaying lyrics and cues for the user(s). Some sound processing and amplification systems includes circuitry for adding echo to the user's voice and possibly additional circuitry to enhance the user's voice. It may also include a mixer for mixing the sound track with the user's voice. The display system is for displaying video information about the music, lyrics and a cue (e.g., color changes of lyrics) to help keep the user's singing on track with the music. Home karaoke players have become popular in recent years. These systems include a player that accepts a microphone input and a karaoke disc or tape and mixes the user's voice with music from the disc, amplifies the sound and reproduces the sound with a speaker. One such system is described in U.S. Pat. No. 5,951,302 to Decker. There are several drawbacks to karaoke systems as described. The first drawback relates to having a separate device that duplicates many of the functions that are already performed by other components often found in homes and business. Many users already have a device that is capable of playing karaoke tapes or disks; for example, a CD player or DVD player. These users often have another device for amplifying and reproducing the music; for example, a stereo system or television. These users often have a device for displaying the lyrics and cues; for example, a television. Therefore, having another device that replicates many of these functions is wasteful and increases clutter. Another drawback to these types of systems is that the controls are often on the device, not the microphone. Being such, the user must approach the device with the microphone to adjust the volume, echo, etc, often causing undesirable feedback and noise. A third drawback is the requirement for a wire from the microphone to the karaoke device. Recently, music players and music/video players have reached the market, often called MP3 players or “iPods.” One such player is the SanDisk Sansa® View Pocket Video Player. This player has audio and video outputs on a single, 4-conductor 3.5 mm headphone jack. Another such player is the iPod from Apple, Inc. The iPod also has audio and video outputs on a single, 4-conductor 3.5 mm headphone jack. Such music players are capable of storing and playing karaoke content. In example of a cable assembly is shown in U.S. Pat. No. 7,070,445 to Shah, et al. The described cable assembly is designed for connecting high-speed Serial Advanced Technology Attachment devices and does not have facilities for analog audio and video signals. Another example of a cable assembly is shown in U.S. Pat. No. 7,134,908 to Wu. The described cable assembly is designed to provide communications between electronic equipment and does not have facilities for analog audio and video signals. Another example of a cable assembly is shown in U.S. Pat. No. 6,583,360 to Yudashkin. The described cable assembly is designed to conduct audio signals but does not have facilities for video signals nor does it have three-way cababilities. What is needed is a three-way cable assembly that interfaces with music/video sources, karaoke devices and display devices. SUMMARY OF THE INVENTION In one embodiment, a three-way cable assembly is disclose with a first connector for connecting to an audio/video source and an input cable with audio input conductors and video input conductors connected to the first connector. An intermediate audio cable has a first set and a second set of audio conductors, the first set of audio conductors are connected to the audio conductors of the input cable. An output cable has output audio conductors; the output audio conductors are connected to the second set of audio conductors of the intermediate connector. The output cable also has video output conductors that connect to the video input conductors. In another embodiment, three-way cable assembly is disclose including a 3.5 mm phone plug for connecting to an audio/video source and having contacts for left-audio, right-audio, video and ground. An input cable interfaces at one end to the 3.5 mm phone plug and has left audio input conductors connected to the 3.5 mm phone plug left-audio, right audio input conductors connected to the 3.5 mm phone plug right-audio, video input conductors connected to the 3.5 mm phone plug video and a ground conductor connected to the 3.5 mm phone plug ground. An intermediate audio cable has first left and right audio conductor and second left and right audio conductor and an intermediate ground, the first left audio conductors connected to the left audio conductors of the input cable and the first right audio conductors connected to the right audio conductors of the input cable. The intermediate ground is connected to the ground conductor of the input cable. An output cable with an output left audio conductor, an output right audio conductors, an output video conductor and an output ground has its output left audio conductors connected to the second left audio conductor of the intermediate connector, the output right audio conductors connected to the second right audio conductor of the intermediate connector, the video output conductor connected to the video input conductor, and the output ground connected to the input ground and the intermediate ground. In another embodiment, a three-way cable assembly is disclosed with a device for connecting to an audio/video source. An input cable with audio input conductors and video input conductors is connected to the device for connecting. An intermediate audio cable with a first set and a second set of audio conductors is provided, the first set of audio conductors are connected to the audio conductors of the input cable. An output cable with output audio conductors is also provided; the output audio conductors are connected to the second set of audio conductors of the intermediate connector. The output cable also has video output conductors connected to the video input conductors and there is a way to physically join the input cable, the output cable and the intermediate cable. BRIEF DESCRIPTION OF THE DRAWINGS The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: FIG. 1 illustrates a block diagram of the present invention used with a first karaoke system. FIG. 2 illustrates a block diagram of the present invention used with a second karaoke system. FIG. 3 illustrates a block diagram of the present invention used with a third karaoke system. DETAILED DESCRIPTION OF THE INVENTION Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. In the following description, a music/video player is used as an example of a source of karaoke content (e.g., music with suppressed vocal tracks, lyrics and video) and a television or TV is used as an example of an output device that includes sound amplification and reproduction as well as video display. There are many other sources of karaoke content that can utilize the cable arrangement of the present invention such as personal computers, CD players, tape players, laser disc players, video cameras and MP3 players. The present invention is not limited in any way to its source of audio/video content. There are many other output devices that include sound amplification and reproduction as well as a display, either in an integrated package or in individual components. Examples of such are stereo systems, monitors, personal computers, etc. For simplicity, the block diagrams exclude a source of operating power. Power supplies including batteries and transformers are well known in the industry. Referring to FIG. 1 , a block diagram of the present invention is shown connected to a portable music/video player 10 , a television 20 and a karaoke device 30 . In this example, a music/video player 10 has an output connector 8 , such as the 3.5 mm audio/video phone jack connector used in several audio/video players. A mating 3.5 mm phone plug 9 is inserted into the output connector 8 making contact with the video signal conductor 13 , the left 12 and right 14 audio signal conductors and a ground conductor 5 , which are routed in input cable 1 to a cable head 4 . The ground conductor is connected to a ground conductor 25 that passes out of the cable head 4 in the output cable 3 to the television 20 . The ground conductor is also connected to a ground conductor 15 that passes out of the cable head 4 in the intermediate cable 2 , and is connected to the karaoke device 30 with a connector 19 . The video signal 13 passes through the input cable 1 , through the cable head 4 and through the output cable 3 to the video input of a television 20 . The left 12 and right 14 audio outputs from the music/video player 10 passes through the input cable 1 , through the cable head 4 and out through an intermediate cable 2 and is connected to the karaoke device 30 with a connector 19 . The left 22 and right 24 audio outputs from the karaoke device pass through the connector 19 , through the intermediate cable 2 , through the cable head 4 and through the output cable 3 to the television 20 . The wires of the output cable 3 are preferably terminated with RCA phono plugs being that most standard televisions accept audio and video signals using RCA phono jacks. Although the cable assembly of the present invention is preferably used in conjunction with a karaoke device 30 that is hand-held and preferably shaped similar to a standard microphone, the intermediate cable works equally well with other karaoke devices or other audio processing devices. In the embodiment where the cable arrangement of the present invention interfaces to a hand-held karaoke device, the hand-held karaoke device 30 has a voice pick-up element 32 situated on an outer surface in a location where it can receive sound waves corresponding to the user's voice. The voice pick-up element converts the sound waves into an electrical signal that is connected to an amplifier 38 that adjustably 39 amplifies the user's voice to a level compatible with the audio outputs 12 / 14 from the music/video player 10 . In the preferred embodiment, the amplifier's output is adjusted by a multi-position switch connected to a resistor ladder. In other embodiments, the amplifier's output is adjusted with a potentiometer or a digital potentiometer having a volume-up and a volume-down push button switch. For most music/video player, the audio output level is usually around 1 volt, peak-to-peak. The audio output signal from the adjustable amplifier 38 interfaces to a selector switch 46 and a sound processor 40 . The sound processor 40 enhances the user's voice by adding, for example, echo. The selector switch 46 lets the user select either audio from the voice pick-up element 32 or from the sound processor 40 . In some embodiments, the selector switch is integrated into an on/off power switch (not shown) having three positions such as off, on and on/echo. The audio output from the selector switch is mixed with the left input 12 by amplifier 36 producing a mixed left audio signal and with the right input 14 by amplifier 34 producing a mixed right audio signal. The outputs of the amplifiers 34 / 36 pass to another selector switch 42 that selects to either pass the left 12 and right 14 audio from the music/video player 10 directly to the outputs 22 / 24 or pass the mixed audio to the outputs 22 / 24 . Referring to FIG. 2 a block diagram of the present invention is shown connected to a portable music/video player 10 , a television 20 and a wireless karaoke device 30 / 30 . As in the prior example, a music/video player 10 has an output connector 8 , such as the 3.5 mm audio/video phone jack connector used in several audio/video players. A mating 3.5 mm phone plug 9 is inserted into the output connector 8 making contact with the video signal 13 and the left 12 and right 14 audio signals, which are routed in input cable 1 to a cable head 4 . The video signal 13 passes through the input cable 1 , through the cable head 4 and through the output cable 3 to the video input of a television 20 . The left 12 and right 14 audio outputs from the music/video player 10 passes through the input cable 1 , through the cable head 4 and out through an intermediate cable 2 and is connected to the karaoke device 60 with a connector 21 A/ 21 B (one single connector shown split for clarity purposes). The left 22 and right 24 audio outputs from the karaoke device pass through the connector 19 , through the intermediate cable 2 , through the cable head 4 and through the output cable 3 to the television 20 . The wires of the output cable 3 are preferably terminated with RCA phono plugs being that most standard televisions accept audio and video signals using RCA phono jacks. In this example, the cable assembly of the present invention is used in conjunction with a wireless transmitter 60 that is wirelessly interfaced to a hand-held karaoke device 30 . The audio transceiver 60 has a modulator 62 (either analog or digital modulation) that modulates the left and right audio onto a wireless carrier such as a radio frequency or an infrared light frequency. Many methods of modulation such as Amplitude Modulation (AM), Frequency Modulation (FM) and Quadrature Modulation (QAM) are known in the industry and any can be used without veering from the present invention. In the example shown, the audio signals are modulated onto an RF signal that passes through an antenna mixer 66 to an antenna 68 where the modulated RF signal radiates and is picked up by an antenna 47 on the karaoke device 30 . The karaoke device 30 is hand-held and preferably shaped similar to a standard microphone. The modulated audio signal from the antenna 47 passes through an antenna mixer 45 and is demodulated by a demodulator 41 into left and right audio signals representative of the left and right audio signals from the music/video player 10 . A voice pick-up element 32 is situated on an outer surface of the karaoke device 30 in a location where it can receive sound waves corresponding to the user's voice. The voice pick-up element is connected to an amplifier 38 that adjustably 39 amplifies the user's voice to a level compatible with the audio outputs 12 / 14 from the demodulator 41 . In the preferred embodiment, the amplifier's output is adjusted by a multi-position switch connected to a resistor ladder. In other embodiments, the amplifier's output is adjusted with a potentiometer or a digital potentiometer having a volume-up and a volume-down push button switch. For most music/video players, the audio output level is usually around 1 volt, peak-to-peak. The audio output signal from the adjustable amplifier 38 interfaces to a selector switch 46 and a sound processor 40 . The sound processor 40 enhances the user's voice by adding, for example, echo. The selector switch 46 lets the user select either audio directly from the voice pick-up element 32 or from the sound processor 40 . In some embodiments, the selector switch is integrated into an on/off power switch (not shown) having three positions such as off, on and on/echo. The audio output from the selector switch is mixed with the left input by amplifier 36 and with the right input by amplifier 34 . The outputs of the amplifiers 34 / 36 pass to another selector switch 42 that selects to either pass the left and right audio from the music/video player 10 to the outputs or pass the mixed audio to the outputs. The outputs of the karaoke device 30 are modulated in a similar way to the modulator in the audio transceiver 60 modulator 62 by another modulator 43 . The modulated signal passes through the antenna mixer 45 and is radiated by the antenna 47 . The radiated modulated audio signals are received by the audio transceiver's 60 antenna 68 and pass through the antenna mixer 66 and are demodulated by a demodulator 64 . The audio output 22 / 24 of the demodulator 64 passes in the intermediate cable 2 through the cable head 4 and through the output cable 3 to the television 20 . Again, it is preferred to have RCA phono jacks on the end of the wires of output cable 3 for compatibility with most televisions. Referring to FIG. 3 , a block diagram of the present invention is shown connected to a portable music/video player 10 , a television 20 and a different karaoke device 70 . In this example, a music/video player 10 has an output connector 8 , such as the 3.5 mm audio/video phone jack connector used in several audio/video players. A mating 3.5 mm phone plug 9 is inserted into the output connector 8 making contact with the video signal 13 and the left 12 and right 14 audio signals, which are routed in input cable 1 to a cable head 4 . The video signal 13 passes through the input cable 1 , through the cable head 4 and through the output cable 3 to the video input of a television 20 . The left 12 and right 14 audio outputs from the music/video player 10 passes through the input cable 1 , through the cable head 4 and out through an intermediate cable 2 and is connected to the karaoke device 70 with a connector 19 . The left 22 and right 24 audio outputs from the karaoke device 70 pass through the connector 19 , through the intermediate cable 2 , through the cable head 4 and through the output cable 3 to the television 20 . The wires of the output cable 3 are preferably terminated with RCA phono plugs being that most standard televisions accept audio and video signals using RCA phono jacks. Although the cable assembly of the present invention is preferably used in conjunction with a karaoke device 70 that includes a wireless microphone, the intermediate cable works equally well with other karaoke devices or other audio processing devices. In this embodiment, the cable arrangement of the present invention interfaces to a karaoke device 70 that has a wireless microphone 47 . A voice pick-up element 32 is situated on an outer surface of a wireless microphone 47 in a location where it can receive sound waves corresponding to the user's voice. The voice pick-up element converts the sound waves into an electrical signal that is connected to an amplifier and modulator 11 that amplifies the user's voice and modulates the audio signal onto a wireless signal (e.g., Radio Frequency or Infrared), emitting the wireless signal on an external antenna 49 or IR transducer (not shown). As discussed previously, any known method of modulation can be used to wirelessly send the user's voice (audio) to the base station karaoke device 70 . The wireless signal is picked up by a matching antenna (or IR transducer) 51 at the base station karaoke device 70 and demodulated by a demodulator 55 producing an electrical audio signal similar to the user's voice. This electrical signal is amplified by an amplifier 38 with volume control 39 to a level compatible with the audio outputs 12 / 14 from the music/video player 10 . In the preferred embodiment, the amplifier's output (volume) is adjusted by a multi-position switch connected to a resistor ladder. In other embodiments, the amplifier's output is adjusted with a potentiometer or a digital potentiometer having a volume-up and a volume-down push button switch. For most DVD players, the audio output level is usually around 1 volt, peak-to-peak. The audio output signal from the adjustable amplifier 38 interfaces to a selector switch 46 and a sound processor 40 . The sound processor 40 enhances the user's voice by adding, for example, echo. The selector switch 46 lets the user select either audio from the voice pick-up element 32 or from the sound processor 40 . In some embodiments, the selector switch is integrated into an on/off power switch (not shown) having three positions such as off, on and on/echo. The audio output from the selector switch is mixed with the left input 12 by an amplifier 36 and with the right input 14 by amplifier 34 . The outputs of the amplifiers 34 / 36 pass to another selector switch 42 that selects to either pass the left 12 and right 14 audio from the music/video player 10 directly to the outputs or pass the mixed audio to the outputs. The outputs of the base station karaoke device 70 passes in the intermediate cable 2 through the cable head 4 and through the output cable 3 to the television 20 . Again, it is preferred to have RCA phono jacks on the end of the wires of output cable 3 for compatibility with most televisions. Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. It is believed that the system and method of the present invention and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.

A karaoke device is included within an enclosure and having a voice pickup element integrated into the enclosure for converting sound waves into an electrical signal. An audio input signal from a DVD player passes into the enclosure and into an electronic circuit for amplifying the electrical signal, for controlling the amplitude of the electrical signal and for mixing the electrical signal and the audio input signal into a mixed audio signal. The resulting audio output signal is delivered to an output device such as a television.

TECHNICAL FIELD OF THE INVENTION [0001] The present invention pertains in general to the collection and analysis of marketing information and in particularly to the identification of a market for a specific product and participants for that market. BACKGROUND OF THE INVENTION [0002] The selling and reselling of automobiles in the United States is a very large industry both in terms of numbers of transactions and dollar volume. New vehicles are sold by franchised automobile dealers who purchase the vehicles directly from the manufacturers. These dealers also sell used vehicles and the purchase and sale of used vehicles is a large product market. There is no single source of supply for used vehicles like that of new vehicles, so the dealers must obtain their inventory of used vehicles from various sources. One source of such used vehicles is the trade-in of vehicles for purchases of new automobiles. However, such vehicles are not necessarily the types of vehicles that the dealer wishes to have in its used car inventory. Therefore, the dealer must obtain a major part of its inventory of used vehicles from other sources. These other sources include large volume wholesale markets and direct purchases from other dealers. [0003] An automobile dealer generally has a desired inventory for its used vehicle supply. The dealer wants to have the vehicles that can be most readily sold and which have the greatest profit margin. One restriction on the purchase and sale of used vehicles is that the dealing most often must be done in a particular geographic region because the transportation of vehicles is expensive and many dealers are hesitant to travel frequently to auctions at distant locations. [0004] Wholesale auctions are a primary means for the marketing of used vehicles. Such auctions can involve thousands of vehicles, but a dealer is often only interested in purchasing a very small percentage of the vehicles that are being offered for sale, thus substantial time can be wasted. Dealers can also use the wholesale auctions to dispose of vehicle inventory which has not been sold within an expected period of time. Thus, a dealer typically both buys and sells at a wholesale market to maintain its desired inventory of used vehicles. [0005] The existing system for the distribution of used vehicles is primarily supply driven. The suppliers of used vehicles “push” their inventory of vehicles to the buyers. This means that information about available used vehicles is broadcast or distributed to potential purchasers with little regard to the actual products needed at that time by each potential purchaser. As a result, the purchasers must each sort through the mass of received information to locate the specific products which are of interest to the particular purchaser. This supply driven system is expensive, inefficient and time consuming for both the suppliers and purchasers of used vehicles. [0006] There are many inefficiencies in the working of the existing market for used vehicles. Due to the wide range in the makes, models and options available for vehicles, it is often challenging for a dealer to obtain the exact types of vehicles in the quantities required for its inventory. Large wholesale markets can increase the chance that a buyer can obtain the desired vehicles, but the larger markets consume greater amounts of time and are thus counterproductive to efficiency in the marketplace. Thus, there exists a need for an improved market system for use in particular with used automobiles, but which is also applicable to other products which are inventoried and sold in a similar manner. SUMMARY OF THE INVENTION [0007] A selected embodiment of the present invention is a method for creating a market for a particular type of product. The products are purchased and sold by dealers and are also provided by suppliers. A dealer may also be a supplier. The process includes a first step of collecting inventory information on a recurring basis for each of a plurality of product classes from each of a plurality of the dealers. A current demand for one or more of the products classes is determined for each dealer based on the dealer inventory information or a sales history of the dealer where the sales history is derived from the dealer sales information. The demands for each of the dealers are aggregated for all of the product classes. A determination is made from the suppliers of the products as to a supply of units available for sale for each of a plurality of the product classes. For each of the product classes a reference is made to predetermined supply and demand volumes for determining the ones of the product classes which have sufficient supply and demand to constitute a viable market. A market is designated for each of the product classes determined to have the sufficient supply and demand volume. For each market, the units of the supply of the product classes are offered to the dealers who have demand for the product class in the market. The market can be conducted in person, through electronic communication such as the Internet, or through a combination of electronic and in-person interaction. [0008] A multi-product type market can be created by combining a plurality of individual product class markets which have at least a minimum number of potential buyers. BRIEF DESCRIPTION OF THE DRAWINGS [0009] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which: [0010] FIG. 1 is a schematic illustration of a communication system for interconnecting a group of dealers and a group of lease companies with a market maker system, [0011] FIGS. 2A and 2B are a flow diagram representing a sequence of steps in accordance with the present invention for collecting demand and supply information and identifying specific markets related to specific product types, [0012] FIGS. 3A and 3B are a flow diagram representing an alternate series of steps in accordance with the present invention for collecting supply and demand information for various product types and identifying specific markets of these product types, [0013] FIGS. 4-7 are dealer inventory and sales data for multiple product types, [0014] FIGS. 8-11 are charts illustrating inventories of product types available for sale from lease companies, [0015] FIG. 12 is a chart of aggregated dealer demand, [0016] FIG. 13 is a chart of aggregated supply, and [0017] FIG. 14 is a chart of identified markets with corresponding dealers and suppliers, and [0018] FIG. 15 is an illustration of a multi-product market. DETAILED DESCRIPTION [0019] The present invention is directed to a system for creating markets for products to be purchased by a group of dealers, which are typically within a given geographical area. The present invention is described in reference to the purchase and sale of used vehicles, but it is also applicable to other products and services which are traded in a similar manner. Referring to FIG. 1 , there is shown a market maker system 4 in accordance with the present invention which works through a network 6 for intercommunication with multiple entities. The network 6 can be, for example, the public telephone system or the Internet In this illustration a plurality of automobile dealers 8 , 10 , 12 and 14 are connected for communication through the network 6 with the market maker system 4 . In addition, a plurality of automobile lease companies 16 and 18 are also connected for communication with the market maker system 4 . [0020] Service marks for representing the market maker system 4 are “Network Market Maker” and “NM 2 .” [0021] Each of the dealers shown in FIG. 1 has a computerized management system, which is often termed a dealer management system (DMS) in the automotive industry. This system tracks the dealer's purchase and sale of vehicles and maintains an inventory listing of all vehicles in the dealer's stock. The inventory information identifies each specific vehicle with associated information such as purchase price, purchase date, and the length of time the vehicle has been in inventory. The lease companies 16 and 18 lease vehicles, and at the end of the lease period many of the vehicles are returned to the lease companies which then make them available for sale at wholesale to dealers. The lease companies may be “captives” of vehicle manufacturers, and therefore sell only specific makes, or a lease company may be independent and offer vehicles from multiple manufacturers. Each of these lease companies has a computer system that maintains an inventory listing of the vehicles that it has for sale. This inventory listing has essential information related to the vehicle. [0022] An inventory data base of each dealer is a listing of the used vehicles in the dealer's inventory together with specific information identifying each vehicle and having information about each vehicle. The information collected about each vehicle in the inventory data base, in a representative environment, is as follows: [0023] 1. Make of vehicle [0024] 2. Model of vehicle [0025] 3. Manufacturer of vehicle [0026] 4. Year of manufacture [0027] 5. Vehicle Identification Number (VIN) [0028] 6. List of options [0029] 7. Purchase price [0030] 8. Date entered into inventory [0031] 9. Mileage [0032] 10. Condition [0033] 11. Repair, service and make-ready costs [0034] Each dealer has a set of formal and/or informal business rules which define the way in which the dealer manages his inventory of used vehicles. This is referred to herein as a “dealer profile.” A dealer develops the profile in order to optimize the profitability of his used car transactions. Dealers typically design the profile based upon their experience in the industry. Such profiles may vary from season to season due to the fluctuation in demand for certain types of vehicles. One aspect of the dealer profile is the number of vehicles that are maintained in stock. This could be limited by the space available to the dealer, financing available to maintain the inventory or by the size of inventory needed to attract customers and close immediate sales. The makeup of the vehicle stock is an important aspect in defining the type of inventory maintained by the dealer. The dealer must maintain a sufficient stock of vehicles that are different to meet the varying requirements of consumers. However, the dealer cannot be so specialized as to maintain vehicles in inventory which may have limited appeal and may remain in inventory for an extended period of time. Thus, the dealers are very careful to maintain what they consider to be an optimum composition of the inventory. This includes quickly restoring inventory after sales and disposing of hard to sell vehicles from the inventory. [0035] A still further aspect of inventory management is the length of time that a vehicle is held in inventory for retail sale. When a vehicle remains in inventory for an extended time, the value of the vehicle is reduced due to depreciation and the expense of the vehicle to the dealer increases due to interest cost. A dealer must have a rapid turnover of inventory in order to sell as many vehicles as possible. The dealer's objective is to sell each vehicle in a retail transaction, but if the vehicle remains in inventory for an extended period of time, it becomes a liability and it is in the dealer's best interest to remove it from inventory as soon as possible. After a vehicle has been in the inventory for more than a predetermined period of time, the dealer generally prefers to dispose of the vehicle at a wholesale price, rather than retaining it for expected sale in the future at retail. [0036] A vehicle category (also referred to as a product class) is defined as a related group of vehicle types, rather than a specific vehicle. One vehicle category can be, for example, F-150 Ford pickup trucks which are less than 3 years old (late model). Although there may be variations within this vehicle category (product class), the vehicles are sufficiently similar for the purpose of marketing and inventory management. The principal factors for defining a category of vehicles are the (1) make, (2) model, and (3) age bracket (either late model, which is the last three years, or intermediate model, which is three to five years old). For example, a Honda Prelude which is one year old is in a different category from a Honda Prelude which is four years old. [0037] For purposes of describing an example for the present invention, the following vehicle categories (classes) are used: Category Year Make Model A. 1998-2001 Mazda 626 B. 1997-2000 Toyota Corolla C. 1996-1999 GMC Jimmy D. 1998-2001 Ford Taurus E. 1996-1999 Oldsmobile Aurora F. 1998-2001 Chevrolet Corsica G. 1997-2000 Pontiac Grand Prix H. 1996-1999 Honda Prelude I. 1996-1999 Isuzu Rodeo J. 1998-2001 Isuzu Trooper K. 1998-2001 Toyota Avalon L. 1998-2001 Honda Civic M. 1998-2001 Nissan Sentra N. 1998-2001 Pontiac Grand Am O. 1997-2000 Jeep Grand Cherokee P. 1997-2000 Nissan Maxima [0038] Briefly, in accordance with the present invention, market maker system 4 collects sales and inventory information periodically from each of the dealers and, based on an analysis of this information, it estimates the demand for each vehicle category for each of the dealers. Market maker system 4 also collects inventory information from each of the lease companies to determine the supply of each category of vehicle from these companies. In certain cases, the dealers may also have vehicles for sale at wholesale, and in these cases the dealers can also be suppliers. Market maker system 4 aggregates the demand for vehicles from the dealers and also aggregates the supply of vehicles from the lease companies and also those dealers who have vehicles for sale. The quantity of each category of vehicle for both supply and demand is compared to a pre-set threshold number of units to determine if a viable market exists for that particular vehicle category. Such a comparison is made for each category for which information is collected. For those vehicle categories which have both substantive supply and demand, a market is identified for that vehicle category. The dealers who have demand for that vehicle category are identified and then invited to participate in a market for the vehicles of that category. A supply of vehicles from the lease companies, and perhaps some dealers, is established such that the vehicles can be sold through the market maker system 4 to the dealers. For greater efficiency, a group of such markets can be combined so that a market of several hundred vehicles can be held at one time. A more detailed description of the present invention is provided in the flow diagrams shown in FIGS. 2A, 2B and FIGS. 3A, 3B , the other figures, and in the accompanying text. [0039] The present invention creates a demand driven market in which the demand for vehicles leads to the consummation of product sales, wherein the demand driven market is in contrast to conventional supply driven markets. [0040] FIGS. 2A-2B represent a first embodiment of the present invention wherein supply information is collected based on previously determined demand. FIGS. 3A-3B represent an embodiment in which comprehensive data is collected for both demand and supply. [0041] Referring now to FIG. 2A for process 20 , following the start, in block 22 a dealer is selected from among a group of dealers who have agreed to participate in the marketing arrangement organized and directed by the market maker system 4 . After selection of a dealer, at step 24 , inventory and sales data is collected from the selected dealer. The collected information is for each vehicle in the dealer's inventory. This is, for example, the inventory and sales data for dealer # 1 shown generally in FIG. 4 . Continuing to step 26 , an inquiry is made to determine if all dealers have been inventoried. If not, a next dealer is selected at step 22 and the process of collecting inventory and sales data is continued until all dealers have been inventoried. Sales information for dealers # 2 , 3 and 4 are shown respectively in FIGS. 5, 6 and 7 . A preferred cycle has a weekly collection of information. This information includes both inventory and sales. As shown in FIG. 4 , dealer # 1 , for a particular week, has the inventory of cars shown for product categories A, B, C, E, F, G, H, J, K and M. A history is maintained of weekly sales with information being obtained each week. As shown in FIG. 4 , a history of sales for the last 18 weeks is maintained. However, weekly sales information for a long period of time may also be maintained and analyzed. [0042] When the inventory and sales information has been collected from all dealers, entry is made to block 28 in which the data for each product unit is “exploded.” This means that the full information about each product unit (vehicle) is collected, and if necessary corrected. The dealer inventory identifies each vehicle by at least the vehicle identification number, but often the dealer information is incomplete or inaccurate. Other sources of data, such as product data from block 30 , can be referenced to provide the additional information to fully characterize each particular vehicle. Complete information of this type is necessary for marketing of the vehicle. Such product data is available from publicly accessible data bases. [0043] At step 36 a comparison is made between a dealer profile and/or the sales history of the dealer for each particular vehicle category in comparison to the current inventory of the dealer to determine the particular dealer's demand for each category of vehicle. This analysis is supported by dealer profiles 38 which have been previously collected or disclosed for each dealer, as well as the sales histories 40 for each dealer which are compiled based on the sales history data that is collected from each dealer. [0044] A particular analytical process for determining such a projected demand based on the collected information is as follows. A dealer may define his desired used vehicle profile as a listing of vehicle categories and a number of days supply for each category. Therefore, the number of vehicles needed to be in inventory for each category is a function of the rate of sale and the number of days supply. For example, if a dealer wants to have a three week supply of vehicles in a particular category and he sells an average of four of these vehicles per week, he would need an inventory of twelve of the vehicles. [0045] An example of a dealer profile is: Vehicle Category Days Supply Sales Rate (per week) No. of Vehicles A 21 3 9 B 28 1 4 C 14 2 4 E 21 4 12 F 28 3 12 G 14 4 8 H 14 2 4 J 28 6 24 K 14 5 10 M 35 3 21 [0046] To determine demand, the dealers preferred inventory for a vehicle category is compared to the actual inventory. If the preferred number of vehicles exceeds the actual inventory, the dealer demand is the difference. Other algorithms may also be used to determine a dealer's demand. The dealer profile above may be defined by the dealer or it may be determined by analyzing the sales history of the dealer. [0047] After the projected demand of each dealer has been determined at block 36 , the dealer demands are aggregated in block 46 for the relevant market, typically for a specific geographical region. See FIG. 12 for an example of aggregated demand. This figure lists all of the product categories and the projected demand for each dealer for each product type. The demands for each product type are summed in the Total Demand column. To the right of the Total Demand there is a listing of the threshold (T/H) values for each product type which must be met in the aggregate demand in order to establish a market based on the supply of units for that product category. [0048] The next step in the process 20 is to determine the vehicle categories which have substantive demand, that is, sufficiently large to justify holding a market. This is performed in step 48 based on pre-set demand values received from block 50 . There must be at least a minimum number of units in demand for a particular vehicle category before it is worthwhile to organize a market for the product in that category. The minimum number of units may vary by vehicle category. For example, a minimum volume for the vehicle category representing late model Ford F-150 pickup trucks may be 5 units. [0049] A market for a vehicle category (product class) also requires a minimum number of buyers, for example, at least two buyers. [0050] Continuing the process 20 description at FIG. 2B , for each vehicle category which has been determined to have substantive demand, at block 52 the available supply for each of these vehicle categories is determined by reference to the suppliers' inventory from block 54 . The suppliers' inventory from block 54 is determined by accessing each of the lease companies such as 16 and 18 shown in FIG. 1 , to determine the supply of the vehicles for each category of interest. The inventories of the dealers are also checked for vehicles which are offered for sale at wholesale. This is a data pull operation for obtaining the supply information. The information concerning the supply of vehicles is pulled from suppliers as shown in FIGS. 8, 9 , 10 and 11 . The market maker system 4 extracts this information from a computer system that has a data storage of this information for each lease company. The aggregated supply is shown in FIG. 13 for each product category. The supply of each product category for each supplier is shown and the total supply (aggregation) is the sum of the supply from each of the suppliers. To the right of the Total Supply column there is a threshold (T/H) listing of minimum units required to establish a market on the supply side. [0051] In block 56 , reference is made to a set of pre-set market values in block 58 to determine if the demand and the supply for each product type is adequate to support a market for that particular product type. Continuing with the above example for a specific product type, a reasonable market for late model Ford pickup trucks should have a supply of at least the number of units of demand. The minimum product units for supply and demand may not be the same for a particular vehicle category. For the vehicle categories which have a number of units in both supply and demand which exceed the minimum threshold values, a vehicle category market is identified. [0052] FIG. 14 illustrates a chart of identified markets with corresponding dealers and suppliers for multiple vehicle categories. [0053] Continuing to block 60 , an identification is made for each of the dealers which have a substantive demand for the products in each of the identified category markets. This is done with respect to a minimum reference number. [0054] The identification of specific markets is shown in FIG. 14 . An “X” is shown in each column for the product type where there is demand by the dealers and supply available from the lease companies. However, a market is not established for each product for which there is both demand and supply. The threshold values must be met for both supply and demand before a market is established. Referring to FIG. 14 , as well as to FIGS. 12 and 13 , it can be seen that the minimum thresholds are met and markets are established for product types A, F, J and O. Even though there is both supply and demand for other product types, the others fail for not meeting at least one of the threshold requirements. There is also a requirement that there be at least two buyers in order for any market to be established. This requirement is also met for the four identified product type categories for which markets have been determined. [0055] Next, in block 66 , a market is scheduled for each vehicle category which has an identified market. At block 68 , each dealer having demand for the products in a market vehicle category is identified and provided with specific information about the market of that product. This identification includes the specific units of product to be sold at the market and the associated product information. [0056] At the selected time, the market is held for the product in a selected vehicle category. This can be either through an online auction sale, a physical meeting at a selected location or a combination of both. At the market, the market maker system 4 can offer the supply of product units for sale with minimum sales prices (reserves) set in advance by the suppliers of the products. The dealers can then purchase the products based on an auction or other sales procedure. [0057] A group of selected vehicle categories can be combined into a multi-category market, such as shown in FIG. 15 . A larger market, beyond one category, can have greater efficiency and productivity for the dealers and suppliers and can be held at a lower cost per category. The data shown in FIG. 15 is a new data set from that previously described in reference to the earlier figures. In this example, a market “ 1 ” is established for vehicle categories A, C and G which involve the identified dealers and suppliers. This market will be held at one time with the product offerings in these three categories. Likewise, the markets “ 2 ” and “ 3 ” will be held at separate times with the vehicle categories, dealers and suppliers as shown in this figure. [0058] An alternative process 80 in accordance with the present invention is described in a flow diagram shown in FIGS. 3A and 3B . This process is much like process 20 shown in reference to FIGS. 2A and 2B , but with certain variations. Following start, entry is made to block 82 to select a first dealer. Continuing to block 84 , inventory and sales data is collected from the selected dealer, in the same manner as described above. At question block 86 , a determination is made if all the dealers have been inventoried. If not, return is made to block 82 . [0059] When the inventories and sales histories of used vehicles have been collected from all of the dealers, entry is made to block 88 for expansion of the data for all the identified product units based upon information received from product data in block 90 . The dealer information is collected as shown in FIGS. 4, 5 , 6 and 7 . The supply information is collected from the lease companies, and any possible dealers, such as shown in FIGS. 8, 9 , 10 and 11 . [0060] In block 96 , a dealer demand is determined by analysis of dealer profiles from block 98 and dealer sales histories from block 100 as described previously in reference to FIGS. 2A and 2B . This demand analysis can be performed as described above in reference to FIGS. 2A and 2B . After the demands for each vehicle category have been calculated for each dealer, these demands are aggregated in block 108 for a selected marketing region. [0061] At step 110 , a first of the suppliers, such as the lease companies 16 and 18 shown in FIG. 1 , is identified. At block 112 the inventory of products is collected from the selected supplier. At block 114 an inquiry is made to determine if the inventories have been collected from all suppliers. If not, return is made to block 110 to select a new supplier and repeat the process. When inventories have been collected from all suppliers, the yes exist is taken from block 114 to block 115 in which the supply for each vehicle category is aggregated for all of the suppliers. This produces a listing of the total supply within the given market region for each vehicle category. See FIG. 13 for a chart of aggregated supply. [0062] Following block 115 , entry is made to block 116 , which is shown in FIG. 3B . In this block the demand for each vehicle category is compared to a minimum demand value received from block 118 . Each vehicle category which has a demand that exceeds a corresponding minimum demand value is selected. Continuing to block 120 , the supply for each vehicle category is compared to a respective set of minimum supply values which are provided from block 122 . The vehicle categories which have at least a number of units greater than the minimum supply values are selected. As an example, a minimum demand and supply may be ten units for a particular vehicle category. [0063] In block 130 the vehicle categories which have unit quantities that meets both the minimum supply and demand values are identified. Next, at block 132 , a market is identified for each of the vehicle categories which have been identified in block 130 . [0064] At block 134 , for each identified vehicle category market, the dealers are selected which have substantive demand for the products of that vehicle category market. Continuing to block 136 , a vehicle category market is scheduled for each of the identified vehicle category markets. At block 138 each selected dealer who has substantive demand for the products of a vehicle category market is notified of the existence and the scheduling of the market for that vehicle category. The process is completed at the end block and then repeated as needed. As described above, multiple vehicle categories may be offered in one market meeting. [0065] Dealers other than those having specific demand may also be notified so that they may attend the vehicle market if interested. [0066] Although several embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications.

A market for used vehicles is identified for a particular vehicle category. A group of dealers are selected who have a high likelihood of buying units of the products. To identify a market, inventory data is collected from each of a group of dealers within a region on a recurring basis. A dealer profile specifying the business rules for managing the inventory is obtained or produced for each dealer. A supply of products is determined by collecting inventory data from suppliers, such as automobile leasing companies and dealers with surplus inventory. The demand for products is determined by comparison of the dealer profile for each vehicle category to the actual inventory for the corresponding vehicle category and/or to the sales history for the product. The data for each product unit is expanded by reference to third party data bases by use of the vehicle identification number. The data thus collected and produced is aggregated for all of the dealers such that there is a composite representation of the demand for each vehicle category. For each vehicle category having a substantive supply and demand, a market is identified. Participants for this market are those dealers who have a significant demand for the products in the market category. The dealers are invited to a market which is called for the particular vehicle category. Multiple vehicle categories may be combined in one market. As a result, a highly efficient market is organized that is directed to one or more specific vehicle categories that are of high interest to a specified group of dealers and suppliers.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of and claims priority from co-pending U.S. Application having Ser. No. 11/728,461, filed Mar. 26, 2007, the full disclosure of which is hereby incorporated by reference herein. BACKGROUND OF THE INVENTION 1. Field of the Invention The disclosure herein relates generally to the field of severing a tubular member. More specifically, the present disclosure relates to an apparatus for cutting downhole tubulars. Yet more specifically, described herein is a method and apparatus for optimizing cutting tubulars wherein lubrication is maintained between the cutting member and the tubular. 2. Description of Related Art Tubular members, such as production tubing, coiled tubing, drill pipe, casing for wellbores, pipelines, structural supports, fluids handling apparatus, and other items having a hollow space can be severed from the inside by inserting a cutting device within the hollow space. As is well known, hydrocarbon producing wellbores are lined with tubular members, such as casing, that are cemented into place within the wellbore. Additional members such as packers and other similarly shaped well completion devices are also used in a wellbore environment and thus secured within a wellbore. From time to time, portions of such tubular devices may become unusable and require replacement. On the other hand, some tubular segments have a pre-determined lifetime and their removal may be anticipated during completion of the wellbore. Thus when it is determined that a tubular needs to be severed, either for repair, replacement, demolishment, or some other reason, a cutting tool can be inserted within the tubular, positioned for cutting at the desired location, and activated to make the cut. These cutters are typically outfitted with a blade or other cutting member for severing the tubular. In the case of a wellbore, where at least a portion of the casing is in a vertical orientation, the cutting tool is lowered into the casing to accomplish the cutting procedure. BRIEF SUMMARY OF THE INVENTION Disclosed herein is a cutting tool and method wherein lubrication is delivered during cutting. The system employs a rotating blade and a lubrication system for dispensing lubrication between the blade's cutting surface and the tubular to be cut. Optionally an isolation material may be included for retaining the lubrication in the cutting region. An example of a cutting tool includes a housing, a cutting member having a stowed position within the housing and a cutting position in cutting contact with the tubular, lubricant stored in a reservoir in the housing, a lubricant dispensing system having an inlet in fluid communication with the reservoir, an exit on the lubricant dispensing system that is sealed when the cutting member is in the stowed position, and open when the cutting member is in the cutting position, so that when the cutting member is in the cutting position lubricant can flow from the reservoir, through the lubricant dispensing system, and from the exit into the space between the cutting member and the downhole tubular. The cutting tool may optionally have a pressure source in pressure communication with the lubricant in the reservoir, so that when the exit on the lubricant dispensing system is open the lubricant is urged from the reservoir and out the exit. The cutting tool can also further include isolation material in a reservoir in the housing, a selectively openable passage between the reservoir and annulus between the cutting tool and the tubular, so that when the passage is opened the isolation material flows from the reservoir into the annulus to form a barrier hindering the lubricant from flowing away from the area where the cutting member contacts the tubular. A conduit may be in the cutting tool between the inlet and exit; also included can be a fastener coaxially coupled with the cutting member, wherein the exit mates with the fastener when the cutting member is in the stowed position to form a seal at the exit, and when the cutting member is in the cutting position the fastener is moved away from the exit thereby removing the seal from the exit allowing lubricant to flow through the conduit and out of the exit. A sealing plug may be slidingly disposed within the conduit that forms a seal in the conduit along its length and is pushed from the conduit by the lubricant when the seal is removed. The lubricant dispensing system can be a frangible conduit having an inlet in fluid communication with the reservoir, wherein the conduit is positioned so that when the cutting member moves from its stowed position to its cutting position it cutting contacts the frangible conduit to form an opening for lubricant to exit. Alternatively, the lubricant dispensing system includes a conduit depending from the exit, a sealing surface in the conduit, a seal element in the conduit in selective sealing engagement with the sealing surface, a portion of the seal element protruding past the exit and in the cutting member path as it moves from its stowed to cutting position, so that when the cutting member moves into its cutting position it contacts the seal element to push it away from the sealing surface to provide a fluid communication path between the reservoir and the exit. The cutting tool can be suspended from the surface on a conveyance member attached to the housing; a motor may be included in the housing coupled to the cutting member, and an anchor can be coupled with the housing having a deployed position in anchoring contact with the tubular. An electrical power supply can be provided at the surface connected to the conveyance member and a conducting member included between the conveyance member and the motor, so that power from the electrical power supply powers the motor. Also disclosed herein is a method of cutting a downhole tubular that includes providing a tubular cutting device that includes a body, a cutting member moveable along a path from a stowed position within the body to a cutting position outside of the body, a supply of lubricant in the body, a lubricant dispensing system in fluid communication with the lubricant having a selectively openable exit, deploying the cutting device within the tubular; contacting the portion of the dispensing system with the cutting member by moving the cutting member from the stowed position to the cutting position, selectively opening the dispensing system exit with the cutting member so that lubricant flows from the exit and in the space adjacent the portion of the tubular to be cut, rotating the cutting member, and contacting the tubular with the rotating cutting member with the lubricant between the cutting member and the tubular. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 . is a side view of an embodiment of a cutting tool in a tubular. FIG. 2 is a side view of an alternative embodiment of a cutting tool in a tubular. FIG. 3 is a side view of an alternative embodiment of a cutting tool in a tubular. FIG. 4 a is a side view of a cutting tool having a lubrication system. FIG. 4 b is a magnified side view of a cutting tool with a lubrication system. FIG. 5 is an overhead view of a cutting blade having lubrication delivery ducts. FIG. 6 is a partial cut away view of a cutting tool disposed in a cased wellbore. FIG. 7 depicts in a perspective view a cutting tool with a lubricant sub. FIGS. 8A , 8 B, 9 A, and 9 B depict in side schematic view a cutting member extending towards a cutting position and opening a discharge port for a lubricant. FIG. 10 illustrates a side schematic view of an example of a cutting member moving into contact with a frangible conduit. FIGS. 11 and 11A provide side schematic depictions of a cutting member moving into activating contact with a lubricant dispensing system. FIGS. 12A and 12B depict in side sectional views an example of a lubricant dispensing system for use with a cutting tool. FIG. 13 provides a perspective view of an example of a cutting tool with a cover. FIGS. 14A-14C and 15 A- 15 B depict in perspective and sectional views an example of a lubricant dispensing system for use with a cutting tool. DETAILED DESCRIPTION OF THE INVENTION The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be through and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. Accordingly, the improvements herein described are therefore to be limited only by the scope of the appended claims. Described herein is a method and apparatus for cutting and severing a tubular. While the apparatus and method described herein may be used to cut any type and length of tubular, one example of use involves severing tubing disposed within a wellbore, drill pipe, wellbore tubular devices, as well as wellbore casing. One embodiment of a cutting tool 10 as described herein is shown in side partial cut away view in FIG. 1 . In this embodiment, the cutting tool 10 comprises a body 11 disposed within a tubular 5 . As noted, the tubular 5 may be disposed within a hydrocarbon producing wellbore, thus in the cutting tool 10 may be vertically disposed within the wellbore tubular. Means for conveying the cutting tool 10 in and out of the wellbore include wireline, coiled tubing, slick line, among others. Other means may be used for disposing the cutting tool 10 within a particular tubular. Examples of these include drill pipe, line pigs, and tractor devices for locating the cutting tool 10 within the tubular 5 . Included within the body 11 of the cutting tool 10 is a cutting member 12 shown pivotingly extending out from within the body 11 . A lubricant 18 is shown (in cross hatch symbology) disposed in the cutting zone 22 formed between the outer surface of the tool 10 and the inner surface 6 of the tubular 5 . For the purposes of discussion herein, the cutting zone 22 is designed as the region on the inner circumference of the tubular, as well as the annular space between the tool and the tubular proximate to the portion of the tubular that is being cut by the cutting tool. Examples of lubricants include hydrogenated polyolefins, esters, silicone, fluorocarbons, grease, graphite, molybdenum disulfide, molybdenum sulfide, polytetrafluoroethylene, animal oils, vegetable oils, mineral oils, and petroleum based oils. Lubricant 18 inserted between the cutting member 12 and the inner surface 6 enhances tubular machining and cutting. The lubricant 18 may be injected through ports or nozzles 20 into the annular space between the tool 10 and the tubular 5 . These ports 20 are shown circumferentially arranged on the outer surface of the tool housing 11 . The size and spacing of these nozzles 20 need not be arranged as shown, but instead can be fashioned into other designs depending upon the conditions within the tubular as well as the type of lubricant used. As discussed in more detail below, a lubricant delivery system may be included with this device for storing and delivering the lubricant into the area between the cutting member and the tubular inner surface 6 . In many situations when disposing a cutting tool within a tubular, especially a vertically oriented tubular, lubricants may be quickly drawn away from where they are deposited by gravitational forces. Accordingly, proper lubrication during a cutting sequence is optimized when lubrication is maintained within the confines of the cutting zone 22 . Additional ports 16 are shown disposed on the outer surface of the housing 11 for dispensing an isolation material 14 into the space between the tubular 5 and the tool 10 . The lubricant port 20 location with respect to the isolation port 16 location enables isolation material 14 to be injected on opposing sides of the lubricant 18 . Isolation material 14 being proximate to and/or surrounding the lubricant 18 retains it within or proximate to the cutting zone 22 . Referring again to FIG. 1 , isolation material 14 is disposed in the annular space between the tool 10 and the tubular 5 and on opposing ends of the lubricant 18 . Thus the isolation material should possess sufficient shear strength and viscosity to retain its shape between the tool 10 and the tubular and provide a retention support for the lubricant 18 . Examples of isolation materials include a gel, a colloidal suspension, a polysaccharide gum, xanthan gum, and guar gum. One characteristic of suitable isolation material may include materials that are thixotropic, i.e. they may change their properties when external stresses are supplied to them. As such, the isolation material should have a certain amount of inherent shear strength, high viscosity, and surface tension in order retain its form within the annular space and provide a retaining force to maintain the lubricant in a selected area. Thus, as shown in FIG. 1 , the presence of the isolating material on opposite sides of the lubricant helps retain the lubricant within the cutting zone. An alternative embodiment of a cutting tool 10 A within a tubular 5 is provided in side partial cross sectional area in FIG. 2 . In this embodiment, nozzles 16 are shown circumscribing the body 11 A outer surface along a single axial location on the tool 10 A. Optionally, in this situation, the nozzles 16 could be disposed on a side of the lubrication nozzles 20 opposite the cutting member 12 . Shown in a side partial sectional view in FIG. 3 is another embodiment of a cutting tool 10 B coaxially deployed within a tubular 5 . In this embodiment the cutting member 12 B is a straight blade affixed to a portion of the body 11 B. Although in this embodiment a single set of nozzles 16 is shown for disposing isolation material 14 into the annular space between the cutting tool 10 B and the inner surface 6 of the tubular 5 , multiple sets of nozzles can be included with this embodiment along the length of the cutting tool 10 B. As shown, the lubricant 18 has been injected into the tubular 5 between the tool 10 B and the tubular inner surface 6 . Thus, the cutting zone 22 includes lubrication for enhancing any machining or cutting by the tool 10 B. Isolation material 14 is also injected into the annular space between the tool 10 B and the tubular thereby providing a retaining support for the lubricant 18 . Another embodiment for delivering lubrication to a cutting surface is provided in FIGS. 4A and 4B . Here an example is provided of delivering a lubricant 18 to the cutting surface of a cutting blade by installing conduits within the blade itself. Shown in side partial sectional view in FIG. 4A is a cutting tool 10 C within a tubular 5 having a blade like cutting member 12 C radially extending from the body 11 C. Rotating the cutting tool 10 C while urging the cutting member 12 C into contact with the inner surface 6 cuts into the tubular 5 , and eventually severs the tubular 5 . Lubricant 18 is provided within a lubricant reservoir (not shown) disposed in the body 11 C. The reservoir is in fluid communication with the cutting member 12 C via supply line 24 shown extending into the cutting member 12 C. Lubricant 18 flows from the reservoir through the supply line 24 and exits the cutting member 12 C through a nozzle exit 26 formed at the supply line 24 terminal end. When discharged from the supply line 24 , the lubricant 18 enters the annular space between the cutting member 12 C and the inner surface 6 . This places the lubricant 18 on the cutting surface 27 of the cutting member 12 C reducing cutting friction thereby enhancing cutting operations. Lubricant 18 may be constantly supplied out into the nozzle exit 26 during a tubular 5 cutting procedure. FIG. 5 provides an overhead view of one example of a cutting member 12 C that includes a blade 29 having conduits formed within its surface for delivering lubricant 18 to a cutting surface. In this embodiment, the cutting member 12 C includes inlays 28 on the blade 29 . Rotating the blade 29 about its axis A X and contacting a tubular with the moving inlays 28 can cut and sever a tubular. Lubricant supply lines 30 , shown in dashed outline, extend linearly along the blade 29 in opposite directions from the blade axis A X . The supply lines 30 terminate at exit nozzles 31 proximate each inlay 28 . Optimization of machining or cutting a tubular can occur by injecting lubricant from the exit nozzles 31 so lubricant is on the cutting surface during cutting. Optionally a nozzle could be formed on an inlay 28 so that lubricant 18 is added during the entire cutting sequence and is present between the cutting blade 29 and the cutting surface. For the purposes of discussion herein, cutting surface can be a surface in cutting contact, this includes the tubular inner surface 6 where it is being contacted by a cutting member as well as any portion of a cutting member or blade contacting a tubular during cutting. FIG. 6 provides a partial side cut away view of an embodiment of a cutting system used in cutting a tubular 7 . In this embodiment a cutting tool 10 D is shown deployed from a conveyance member 8 into a cased wellbore 4 that intersects a subterranean formation 2 . The tubular 7 is coaxially disposed within the wellbore casing. Optionally, the cutting tool 10 D may be employed for cutting the wellbore casing and used in the same fashion it is used for cutting the tubular 7 . Examples of means used in deploying the tool 10 D in and out of the wellbore 4 by the conveyance member 8 include wireline, slick line, coil tubing, and any other known manner for disposing a tool within a wellbore. Shown included with the cutting tool 10 D is a controller 38 , a lubricant delivery system 40 , an isolation material delivery system 46 , and a cutting member 12 . The controller 38 , which may include an information handling system, is shown integral with the cutting tool 10 D and may be used for its control. The controller 38 may be configured to have preset commands stored therein, or can receive commands offsite or from another location via the conveyance member 8 . An optional anchoring system 32 is shown having anchor legs extending outward from the cutting tool 10 D into anchoring contact with the tubular 7 inner surface. The lubricant delivery system 40 can be employed to deliver lubricant 18 within the space between the cutting member 12 and tubular 7 . The delivery system 40 shown includes a lubricant pressure system 42 in communication with a lubricant reservoir 44 . The pressure system 42 is adapted for conveying lubricant 18 from within the reservoir 44 through the tool 10 D and into the annular space between the cutting tool 10 D and the tubular 7 and adjacent the cutting member 12 . The pressure system 42 may be spring loaded, a motor driven pump, or include pressurized gas. Further depicted with the cutting tool 10 D of FIG. 6 is an isolation material pressure supply 48 and an isolation material reservoir 50 that are included with the isolation material delivery system 46 . The isolation material pressure supply 48 , which can have a pump, spring loaded device, or compressed gas, may be used in urging isolation material 14 from within the isolation material reservoir 50 and out into the annular space between the tool 10 D and the tubular 7 . It should be pointed out that the isolation material 14 and lubricant 18 can be simultaneously ejected from the cutting tool 10 D. Optionally either the isolation material 14 or lubricant 18 may be delivered into the annular space before the other in sequential or time step fashion. As far as the amount of lubricant 18 or isolation material 14 delivered, it depends on the cutting tool 10 D and/or tubular 7 dimensions; it is believed it is well within the capabilities of those skilled in the art to design a system for delivering a proper amount of lubricant 18 as well as isolation material 14 . As shown with the embodiment of FIG. 6 , the cutting member is in a cutting sequence for cutting the tubular 7 and isolation material 14 is shown retaining a quantity of lubricant 18 adjacent the cutting member 12 thereby maintaining the lubricant 18 in the space between the cutting member and the tubular 7 . A controller 34 disposed at surface may be employed for relaying commands to or otherwise controlling the cutting tool 10 D. The controller 34 may be a surface truck (not shown) disposed at the surface as well as any other currently known or later developed manner of controlling a wellbore tool from the surface. Included optionally is an information handling system 36 that may be coupled with the controller 34 either in the same location or via some communication either wireless or hardwire. Also illustrated schematically is a power supply 35 shown disposed on the surface above the wellbore 4 and in communication with the conveyance member 8 . The power supply 35 can selectively provide power to the cutting tool 10 D via the conveyance member 8 that can be used for controls and/or motors within the tool 10 D. It should be pointed out that the exit nozzles can have the same cross sectional area as the supply lines leading up to these nozzles, similarly other types of nozzles can be employed, such as a spray nozzle having multiple orifices, as well as an orifice type arrangement where the cross sectional area at the exit is substantially reduced to either create a high velocity stream or to atomize the lubricant for more dispersed application of a lubricant. Referring now to FIG. 7 , provided therein is a side perspective and partial sectional view of an embodiment of a cutting tool 52 . The cutting tool 52 shown is a generally elongated member having a cylindrical outer body or housing 54 . Within the housing 54 is a motor 56 coupled to a circular cutting member 58 on its lower end. A fastener 60 couples on the cutting member 58 lower surface coaxial with the cutting tool 52 . The fastener 60 may be a nut that is screwed onto a shaft (not shown) extending from the motor 56 . Optionally, a gearing system (not shown) may mechanically connect the motor 56 and cutting member 58 . Below the cutting member 56 the housing 54 tapers into a frusto-conical section to define a nose portion 62 . A bore 64 is shown axially formed through the nose portion 62 and in alignment with the fastener 60 . A cylindrically shaped nozzle 66 is disposed in the bore 64 having an upper end in contact with the fastener 60 lower surface. The nozzle 66 lower most end juts into a cylindrically shaped lubricant sub 70 that is attached along the conically contoured nose portion 62 outer surface. The lubricant sub 70 is shown in sectional view as a generally hollow member having on its upper end a cylindrically shaped plug 72 that abuts the nose portion 62 lower end. A ferrule 74 shown coaxially within the plug 72 registers with a passage 68 coaxially formed through the nozzle 66 . A reservoir 76 is defined within an open space in the sub 70 that is below the plug 72 . Lubricant may be stored in the reservoir 76 for injection between the cutting member 58 and a tubular inner surface. As noted above, injection of the lubricant onto a cutting surface enhances the cutting deficiency of a cutting tool. In the embodiment of FIG. 7 a pressure source is provided within the lubricant sub 70 depicted as a combination of a piston 78 and spring 80 . The piston 78 illustrated is a cylindrical element defining the reservoir 76 lower periphery. The spring 80 , which coils helically along the inner circumference of the sub 70 , has a lower end in contact with the lower most surface of a sub 70 in an upper end in contact with the piston 78 . Thus as lubricant is expelled from the reservoir 76 the spring 80 expands to urge the piston 76 upwards in the direction of the plug 72 . Other pressure means may be employed, such as compressed gas, an expandable bladder, and selectively openable ports adapted to receive wellbore fluid therein. FIGS. 8A and 8B provide an enlarged view of a portion of the cutting tool 52 where it couples with the lubricant sub 70 . In these views shown is the passage 68 coaxially formed within the nozzle 66 and how it registers with a dispensing line 75 coaxially formed through the ferrule 74 . The combination of the dispensing lines 75 and passage 68 form a conduit adapted for flowing lubricant within the reservoir 76 out into the cutting space between the cutting member 58 in the tubular. More specifically, in FIG. 8A the nozzle 66 upper end is depicted in sealing contact with the fastener 60 bottom blocking the passage 68 exit. Shown in FIG. 8B the cutting member 58 is moving into a cutting position by pivoting radially outward breaching sealing contact between the fastener 60 and nozzle 66 exit. Therefore lubricant within the reservoir 76 now has a clear path from the nozzle 66 exit and can flow from the reservoir, through the conduit, and out of the nozzle 66 exit. Once past the nozzle 66 exit the lubricant can make its way to between the cutting member 58 and tubular. A resilient member 69 is shown in the space between the nozzle 66 and ferrule 74 that provides an outwardly urging force maintaining the sealing contact between the nozzle 66 exit and fastener 60 . In an example the resilient member may be a spring. FIGS. 9A and 9B respectively represent side schematic depictions of a cutting member 58 in a stowed position within the housing 54 and in a cutting position in cutting contact with a tubular. The cutting tool 52 embodiments shown in FIGS. 9A and 9B includes a dispensing line 75 representing a conduit for communicating fluid between the reservoir 76 and lubricant exit. The dispensing line 75 exit is shown in sealing contact with the fastener 60 lower surface. Further provided in the embodiments of FIGS. 9A and 9B is a sealing plug 77 slidingly disposed within the dispensing line 75 . The presence of the sealing plug 77 enhances the pressure seal between the lubricant within the reservoir 76 and ambient the dispensing line 75 . Referring now to FIG. 9B , the cutting member 58 and fastener 60 have moved radially outward from the tool 52 axis A X thereby removing contact between the exit from the dispensing line 75 and fastener 60 . This opens the dispensing line exit 75 allowing the flow of lubricant from the reservoir 76 , represented by arrows, through the dispensing line 75 and into the ambient space, where it can make its way or be directed into the space between the cutting element and tubular. A schematic of an alternate cutting tool 52 A is provided in a side sectional view in FIG. 10 . In this embodiment, a lubricant reservoir 76 within the housing 54 is shown containing lubricant L providing a lubricant supply. A dispensing line 75 A provides fluid communication between the lubricant reservoir 76 and a frangible tube 82 shown disposed in the path between the cutting member 58 stowed position and its cutting position. The frangible tube 82 is formed from a material that can be ruptured or otherwise severed by cutting contact with the cutting member 58 . Moreover, the frangible tube 82 has a sealed terminal end. In the embodiment of FIG. 10 , the end is attached to a solid portion of the body 54 . Optionally, the frangible tube 82 can stand freely in the cutting member 58 path and have a closed end rather than attached to the body 54 . In the embodiment of FIG. 10 , the cutting member 58 which is in cutting rotation, cuts the frangible tube 82 to form an opening. The opening cut into the frangible tube 82 provides an exit for lubricant L within the reservoir 76 to be dispensed into the space outside of the housing 54 and onto the surface of the tubular to be cut by the cutting member 58 . Shown in a side schematic partial sectional view in FIG. 11 is an alternate example of a cutting tool 52 B in accordance with the present disclosure. In the embodiment of FIG. 11 a dispensing unit 86 is shown in fluid communication with a dispensing line 75 B connected on an upstream end to the lubricant reservoir 76 . Contact between the cutting member 58 and a protruding portion of the dispensing unit 86 opens a fluid path between the lubricant reservoir 76 and the area outside the housing 54 . FIG. 11A shows in a side sectional view, an enlarged view of the dispensing unit 86 and its interaction with the cutting member 58 . The dispensing unit 86 includes a cylindrical hollow outer housing 88 , a spherical seal plug member 90 within the housing 88 , an annular lip 91 on the exit portion of the housing 88 , and a spring 92 in urging contact against the seal plug member 90 on the side opposite the annular lip 91 . Referring back to FIG. 11 , a portion of the seal plug member 90 protrudes past the remaining elements in the dispensing unit 86 . In this configuration, the seal plug member 90 contacts the inner radius of the annular lip 91 urged upward by the spring 92 to create a sealing surface between the seal plug member and annular lip 91 . The dispensing unit 86 shown is configured so that a portion of the seal plug member 90 protrudes into the cutting member 58 path. Thus, as the cutting member 58 moves into its cutting position from its stowed position, it contacts the seal plug member 90 pushing it further inside the housing 88 and depressing the spring 92 . This unseats the seal plug member 90 from the annular lip 91 allowing lubricant from within the reservoir 76 to exit from within the housing 54 . Shown in a side sectional view in FIGS. 12A and 12B is another embodiment of a lubricant to cutting surface delivery system. With reference to FIG. 12A , a bore 64 C extends through the nose portion 62 between the reservoir 76 and cavity 63 within the cutting tool 52 C. A threaded plug 65 is fastened within an end of the bore 64 C adjacent the reservoir 76 . An elongated piston like sealing plug 77 C is slidingly provided within the bore 64 C having a portion shown extending outside the bore 64 C and into the cavity 63 . The sealing plug 77 C outer surface is scored on its outer circumference to form a notch 79 and its upper end terminates at the fastener 60 lower surface. An extension 61 is shown depending downward from the fastener 60 lower surface to below the sealing plug 77 C upper end. Both the bore 64 C and sealing plug 77 C diameters transition from a larger to a smaller diameter. In the configuration of FIG. 12A , the respective diameter transitions are at different locations to form an annular space 73 around a portion of the smaller diameter section of the sealing plug 77 C. Also in the bore 64 C is a spring 67 shown between the threaded plug 65 and sealing plug 77 C that forces the sealing plug 77 C upper end against the fastener 60 . Also included in this embodiment is a passage 71 bored through the nose portion 64 C with an end in fluid communication with the reservoir 76 and an opposite end connecting to the dispensing line 75 C. The dispensing line 75 C has an exit proximate the cutting member 58 . The passage 71 intersects the bore 64 C along a portion in which the plug 77 C is disposed. In the embodiment of FIG. 12A , a seal is formed along the area where the sealing plug 77 C contacts the passage 71 that blocks fluid communication between the reservoir 76 and dispensing line 75 C. As the blade 58 is rotated and pivoted radially outward from the cavity 63 , the attached extension 61 collides with the sealing plug 77 C and applies a sufficient moment arm to fracture the sealing plug 77 C along the notch 79 . Referring now to FIG. 12B , removing the portion of the sealing plug 77 C above the notch 79 , allows the spring 67 to expand and upwardly urge the remaining section of sealing plug 77 C. This unseats the seal between the sealing plug 77 C and passage 71 thereby allowing lubricating fluid within the reservoir 76 to be communicated through the passage 71 , to the dispensing line 75 C, and then delivered to a cutting surface. The sealing plug 77 C is prevented from being ejected from the bore 64 C by contact between the diameter transitions on the bore 64 and sealing plug 77 C, thus eliminating the annular space 73 . The present disclosure further includes using a cutting tool with a lubricant to cut tubulars with increased chrome amounts, as well as alloying elements such as nickel, vanadium, molybdenum, titanium, silicium. This method is also applicable to cutting in environments with water, salt water, and drilling fluids. A cover 55 may be provided with an embodiment of the cutting tool 52 D for retaining grease within the tool 52 D. Shown in perspective view in FIG. 13 , the cover 55 envelops a portion of the cavity 63 where the blade 58 is deployed. The cavity 63 can be packed with grease prior to being deployed and the cover 55 put in place thereby retaining the grease in the cavity 63 and on the blade 58 while the tool 52 D is being lowered downhole. The cover 55 is shown hinged on an end to the housing 54 D so that it can swing open and not impede the blade 58 as it is pivoted radially outward. Selectively opening the cover 55 during cutting enables grease to also migrate to the cutting surface. The cover 55 may be biased, such as with a spring or like member, so that it follows the blade 58 and closes over the cavity 63 as the blade 58 is re-stowed within the housing 54 D). In an optional embodiment shown in FIGS. 14A-15B , grease and/or lubricant from a reservoir on one side of the cutting blade 58 can be dispensed to an opposite side of the blade 58 . Shown in a partial sectional perspective in FIG. 14A , a section of the nose portion 62 E of the cutting tool 52 E projects past the cutting blade 58 having an end terminating at a blade mount 93 . The blade mount 93 shown houses a portion of a shaft 94 for rotating the cutting blade 58 and gears for driving the shaft 94 . A pivot shaft 95 couples within the blade mount 93 , that when rotated pivots the blade mount 93 and blade 58 . In the cutting tool 52 E example of FIGS. 14A-14C , when the tool 52 E is being deployed and the cutting blade 58 is stowed, the sealing plug 77 E end opposite the spring 73 is urged against the fastener 60 by the spring 73 . Grease and/or lubricant may be introduced into the reservoir 76 E via an inlet port 83 disposed in a lateral bore 85 formed radially inward into the nose portion 62 E. An axial bore 87 intersects the lateral bore 85 to communicate grease and/or lubricant injected into the port 83 to the reservoir 76 E. The lateral bore 85 as shown intersects the passage 71 E. A channel 81 is provided on the blade mount 93 on a side of the cutting blade 58 opposite the reservoir 76 E ( FIG. 14B ). The channel 81 registers with the passage 71 E discharge side and extends along the blade mount 93 . The other end of the channel 81 terminates between the blade 58 outer periphery and mid section in communication with the side of the blade 58 opposite the reservoir 76 E. Thus lubricant and/or grease can be dispensed onto the cutting blade 58 by flowing it from reservoir 76 E, into the passage 71 E, and through the channel 81 . FIG. 14C provides a sectional view of the cutting tool 52 E taken along its axis on the reservoir 76 C side of the cutting blade 58 . The section of the nose portion 62 E extending past the blade 58 has a width that tapers along its circumference thereby forming a crescent shape. The wider section of the nose portion 62 E is disposed proximate and perpendicular to the pivot shaft 95 . The wider section also includes the passage 71 E discharge; thus as shown, the passage 71 E discharge is proximate to the pivot shaft 95 . FIGS. 15A and 15B provide side and axial sectional views of the cutting tool 52 E in a cutting position. The section of the nose portion 62 E extending past the blade 58 encircles less than half the blade 58 ; this leaves an open space allowing the blade 58 to pivot radially outward into cutting contact with a tubular. Because the passage 71 E discharge is aligned with the pivot shaft 95 , the passage 71 E remains registered with the channel 81 while the blade mount 93 and blade 58 are being pivoted into cutting contact. Thus as the blade 58 spins during a cutting procedure, grease and/or lubricant can be deposited on its side and delivered to the cutting surfaces such as by the centrifugal force of the blade 58 . The improvements described herein, therefore, are well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While presently preferred embodiments have been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present disclosure and the scope of the appended claims.

The tubular cutting tool for severing downhole tubulars, the tool having a drive system, a pivoting system, a cutting head, a cutting member, and a lubricant delivery system. Cutting may be accomplished by rotatingly actuating the cutting head with an associated motor and extending the cutting member away from the cutting head. The lubricant delivery system lubricates the respective contacting surfaces of the cutting member and the tubular and is actuated when the cutting member extends from the cutting head.

ORIGIN OF THE INVENTION The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 USC 2457). BACKGROUND OF THE INVENTION This invention relates to an active retrodirective array (ARA) antenna, and more particularly to a phase conjugation circuit which eliminates squint in a large ARA. Systems employing retrodirective antennas receive and transmit (retrodirect) signals at different frequencies in order to provide input-output isolation. Such retrodirective antenna systems have been disclosed in repeaters for satellite communications systems. Representative of this prior art are patents to Margerum U.S. Pat. Nos. (3,300,782), Stahler (3,350,642), Preikschat et al (3,611,381), Raabe (3,757,334) and Albert (3,898,663). The problem with this prior art is that the phase conjugation circuits are not "exact" resulting in a pointing error known as "squint." The term "exact" as applied to phase conjugation is defined below. In some applications it is necessary to retrodirect a narrow beam from a large antenna array on a satellite, and to continually steer the retrodirected beam to the center of a receiving antenna on the ground. Though not yet in practical use, ARA's are expected to become an important part of phased array technology. They have been proposed for such applications as satellite communication networks, aircraft transponders, and even for microwave powder transmission from an orbiting solar power station. The ARA steers a beam towards the apparent source of an illuminating signal called the pilot signal. In the case of communication satellites, for example, the pilot signal would be transmitted from a ground station with which the satellite communicates. Much of the current interest in ARA's is centered about its possible application to a solar power satellite (SPS). The SPS would be placed in a geosynchronous orbit. Several gigawatts of microwave power, generated by and converted from the dc output of huge solar cell panels, would be transmitted to a rectifying antenna ("rectenna") on the Earth's surface. The SPS-rectenna range would be 36,000 km, the rectenna diameter 7.4 km, and the frequency S-band (λ≈12.5 cm). These parameters plus stringent sidelobe requirements imply a transmitting antenna on the SPS about 1.0 km in diameter. The pointing loss becomes unacceptable if the miss radius exceeds 200 m, which, in angular terms, corresponds to 5.6×10 -6 radians=1.1 arc seconds. Because of the obvious difficulty in mechanically pointing a 1.0 km diameter antenna to this accuracy, the proponent of the SPS suggest using an ARA for the spacecraft antenna with the pilot source located at the center of the rectenna. An equally important reason for using an ARA for the SPS is safety, specifically, the need to protect the public from exposure to the high power beam. Although no beam pointing system is infallible, the ARA would seem to be the most inherently reliable system for this application since its retrodirectivity is inseparable from the beam forming process itself. Such pointing errors that are known to exist produce only slight (compared to rectenna diameter) mispointing. Moreover, the response time of an ARA is determined by its own dimensions, not by the ground to spacecraft round trip delay as it would be for a conventional closed loop control system. It would, therefore, be of the order of microseconds, not 2×36×10 6 /(3×10 8 )=0.24 seconds, the round trip delay for an SPS in geosynchronous orbit. The applicability of ARA's to communication satellites has also been noted. Large antennas on communication satellites will be required not only to serve ground receivers with small apertures (as in direct TV transmissions), but also to provide the directivity needed for spectrum conservation. A communication satellite ARA could use either frequency or time division multiplexing. In a frequency multiplexed version designed to communicate with each of N ground station, each element of the array is equipped with N phase conjugation circuits, and each circuit responds only to the carrier frequency of the pilot signal transmitted by one of the N stations. Information modulated on the carrier of the pilot signal from one of the stations, call it Station A, is demodulated and remodulated onto the carriers of downlink signals retrodirected to one or more of the other ground stations. Similarly, information from any of these other stations can be simultaneously modulated onto the downlink to A. The average power available for each downlink must, of course, decrease with N, but the full gain of the array is available to each downlink independently of N. If time division instead of frequency multiplexing is used, only one phase conjugation circuit and one receiver is required for each element. However, the bandwidth of that receiver must be N times greater than that of each of the N receivers required in the frequency multiplex case. Depending on the dimensions of the array, the required bandwidth, and the scan angles required to point beams at different ground stations, time delay compensation may be required in order to properly synchronize the data streams transmitted by the various elements. ARA's may also be useful as deep space probe antennas. As the distance times data rate product increases, it will eventually become necessary to use spacecraft apertures too large to be mechanically pointed. Here, however, certain errors proportional to the velocity of the spacecraft relative to the ground station may become important. They are unimportant in geosynchronous satellites, such as the SPS and most communication satellites, because of their small relative velocities, but deep space probes may experience much higher velocities in the course of a mission, and this factor may limit the size of the ARA which can be used on such spacecraft. It has been noted above that an ARA can function as a receiving array. Such arrays may be useful for receiving weak signals from very distant deep space probes or as radio astronomy arrays. Since low noise front ends are fairly expensive, such an array would probably consist of a modest number of fairly large antennas rather than a very large number of small elements. Each of the large elements would be mechanically steered to keep the source within its beamwidth. As in communication satellite ARA's, data processing may be required to remove time delay distortion. An improved method and apparatus for an active retrodirective antenna which uses "central phasing" is disclosed in a copending application Ser. No. 777,983 filed Mar. 16, 1977. Before briefly summarizing the concept of "central phasing," a definition of terms and important principles will first be introduced. An active retrodirective array (ARA) transmits a beam towards the apparent source of an illuminating signalcalled the pilot. "Active" implies that the array produces, not merely reflects, RF power. Retrodirectivity is achieved by retransmitting from each element of the array a signal whose phase is the "conjugate" of that received by the element. Assuming that the phase of the pilot signal of angular frequency ω received by the kth element of the array at time t is φ.sub.k (t)=ω(t-r.sub.k /c) (1) where r k is the distance from the kth element to the source of the pilot signal, we define the conjugate of φ k to be φ.sub.k * (t)=ω'(t+r.sub.k /c)+θ.sub.o ( 2) where ω' is the angular frequency of the conjugate signal, which in general is not the same as that of the pilot signal, and θ o is an arbitrary phase offset which must, however, be constant over the entire array. In order to do this, each element of the array must be equipped with a phase conjugation circuit (PCC). The phase of the signal received from the kth element by a receiver located at the pilot source (4=o) is, at time t, φ.sub.k * (t,o)=ω'(t+r.sub.k /c-r.sub.k /c)+θ.sub.o =ω't+θ.sub.o ( 3) Thus the contributions to the field at r=o from the various elements of the array are all in phase at that point, which means that the beam points toward the pilot source. Previous definitions of phase conjugation included only the case ω'=ω. Here the definition is generalized in order to emphasize that ω'=ω is neither necessary nor desirable; retrodirectivity holds in either case provided only that the propagation medium is non-dispersive, and ω'=ω is usually to be avoided because of input-output isolation problems. The term "exact conjugation" means that Equation (2) is satisifed exactly, rather than approximately. In a planar array (the most common geometry for antenna arrays) the effect of inexact conjugation is to misdirect (squint) the beam by an angle proportional to both the scan angle (the angle of incidence of the pilot signal) and the ratio ω'/ω. Thus, in applications requiring very precise beam pointing, phase conjugation for each array element must be exact to avoid squint. It is also evident that the phase conjugation circuit (PCC) design must avoid any "mixer degeneracy" which may cause large unpredictable phase errors. Prior art phase conjugators which shift the received signal frequency in generating a conjugate signal do so in a manner which results in inexact phase conjugation. "Mixer degeneracy" refers to either of two cases: a down-converter in which the frequency of one of the inputs is twice that of the other, or an up-converter with equal input frequencies. In either case the output signal contains two components with distinct phases. Only one of these components has, in general, the correct phase, but due to their common frequency, the two components are indistinguishable. Hence a phase error is produced of a magnitude that depends upon the vector sum of the two components. An ARA can also function as a receiving (i.e., tracking) array. It is easy to show how a single PCC at each element can be used for both functions, receiving as well as transmitting, simultaneously, with little additional equipment. From Equations (1) and (2) it is seen that phase conjugation amounts to advancing the phase of an input signal by an amount equal to its delay. The phase conjugation circuit (PCC) must, therefore, be provided with a phase reference against which to measure that delay. If each PCC is located at its associated ARA element, then it is clear that the phase reference must be transmitted to each PCC from some central source via transmission lines of equal phase delay modulo 2π. But it may be difficult to do this if the transmission lines are very long. For example, consider the 1.0 km diameter SPS ARA described above operating at S-band (λ=12.5 cm). If the master phase reference is located at the center of the disk, the transmission lines to elements at the periphery will be 500 m long. In order to keep the phase delay in this line constant to within π/10 radians, its length must not vary by more than ±λ/20 cm, or a relative change no greater than ±1.2×10.sup. -5. But this length change would be produced in an aluminum line by a temperature change of only 0.5 degrees C, or by a mechanical stress of only 120 psi. The results for other good conductors are similar. Since it is reasonable to expect temperature and stress changes far greater than these in this huge structure, it is clear that the required dimensional stability cannot be met with materials commonly used for transmission lines. While it might be possible to solve this problem with uncommon materials, it is possible to avoid it altogether by locating all PCC's at the reference source rather than at their respective elements. This method of providing the phase reference is referred to above as "central phasing" and will be described more fully hereinafter. The phase reference for this ARA is the pilot signal received by the 0-th, or reference, element. The pilot signal received by the kth element is transmitted to its associated PCC located at the reference element via a transmission line and diplexer. The PCC conjugates the entire phase delay, i.e. the sum of the space delay, ωr k /c, and the transmission line delay, ωl ko /c L , where c L is the phase velocity of the line, and transmits that conjugate signal back down the same transmission line to the kth element, which retransmits it. Its phase at that point is ω'(t+r k /c)+θ o which is exactly what it would be were the PCC located at the kth element rather than at the reference element. Thus the length of the transmission line is immaterial provided only that: first the line is dispersionless, and second its length is constant with time. The importance of central phasing lies in the fact that it liberates the ARA from the rigid structure which would otherwise be needed in order to realize accurate retrodirectivity. The elements need not be arranged in any particular geometrical pattern, and may, in fact, move about with respect to one another provided the movement is not too rapid. This applies, of course, only to pointing accuracy, not to side lobe levels or other characteristics of the antenna array. Locating all the PCC's in one small volume very near the reference element may be difficult if the array contains thousands of elements. A modification of the central phasing concept using a tree topology (in which the phase reference is regenerated at each node and which will be required in such large arrays) is disclosed in the aforesaid application. Each branch of the tree consists of a PCC, located near the node, and an element of the ARA at the end of a transmission line. A phase reference supplies all the PCC's connected to a node. At the initial node, this is the reference element of the array. At subsequent nodes, it is a phase reference regenerator (PRR). The PRR combines samples of the pilot and conjugate signals at an element to reproduce the original reference. Since the signal paths within these nodes assemblies are unilateral, their phase delays must be carefully balanced in order to avoid phase error buildup at successive nodes. In order to assure the stability of the phase delay balance, these assemblies must be uniform and compact. Critical applications may require temperature stabilization of some active elements. The number of nodes in a tree is relatively small even for an ARA of several thousand elements. For example, with six branches at each node, a tree of only five nodes suffices for an array of 9331 elements. PRRs are required only at the first through fourth order nodes of this tree. A PRR at a fourth order node is the last in a chain of four PRRs connecting the PCCs at that fourth order node to the reference elements of the ARA. The error in the value of the phase reference produced by this last PRR is the sum of the errors arising in all the PRR's in the chain. If these errors arise from independent and identical random processes in each PRR, then the probable error of the output of the last PRR is √4 (PE) 2 =2 (PE) where PE is the probable error of each PRR. Thus the error buildup due to repeated regeneration of the phase reference is moderate even for large arrays. SUMMARY OF THE INVENTION An active retrodirective antenna array has central phasing from a reference antenna element through "tree" structured network of transmission lines to electronically point a microwave beam to the apparent source of a incident beam using a new phase conjugation circuit (PCC) and a new phase reference regeneration circuit (PRR) in each branch. Each PCC is connected at a node which, in the case of the node located at the reference element, receives the reference phase, φ o , from the reference element directly, and in the case of other nodes located at other antenna elements, from a PRR in a node assembly at the element. The PRR extracts the reference phase from the conjugate phase at the node of another plurality of PCCs, each of which is connected to antenna elements by a transmission line. The PCC generates the conjugate phase φ 1 * of an incident signal φ 1 in accordance with the relation R(2φ o -φ 1 ) where R is equal to the reciprocal of 1-2/n, and n≧4, using a phase locked loop. The VCO of the loop is controlled by a phase detector whose phase inputs are 1/2 (φ 1 *+φ 1 )-φ o and φ 1 */n respectively, where phase φ 1 * is the phase of the VCO output. That phase φ 1 * is also the phase conjugate of phase φ 1 can be seen by equating the phase detector inputs and solving for φ 1 *. A PRR regenerates the phase φ o from a conjugate φ 1 * by first mixing φ 1 */2 and φ 1 */n in a down-converter to obtain φ o -φ 1 /2, and mixing an up-converter with φ 1 /4. The phase sum of that up-converter is then mixed with φ 1 /4 in an up-converter to regenerate the phase φ o . BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a tree structure for a centrally phased ARA as shown in the aforesaid patent application. FIG. 2 illustrates an improved PCC for the ARA of FIG. 1. FIG. 3 illustrates an exemplary embodiment of a PRR for the ARA of FIG. 1. DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. 1, there is disclosed an active retrodirective array (ARA) of the centrally phased type using a tree structure to distribute a reference phase φ o from one of many antenna elements 0, 1, . . . k . . . to phase conjugation circuits (PCCs) for all elements of the array. Retrodirectivity is achieved by retransmitting from each element of the array a signal whose phase is the conjugate φ k * of the phase φ k received by the kth element, as described generally with reference to Equations (1), (2) and (3). From that general description it is seen that the phase of a pilot signal received at time t by the kth element of the array may be expressed as ω(t- r k/c) where ω is the radian frequency of the pilot signal, r k is the distance from the pilot source 10 to the kth element, and c is the phase velocity in the intervening medium. Phase conjugation may be expressed as the operation: ω(t-r.sub.k /c)→ω'(t+r.sub.k /c)+θ.sub.o (4) where θ o is the constant phase offset determined by φ o . A phase conjugation circuit (PCC) 11 is associated with each element of the array to perform this operation with the same phase reference φ o for all elements 1 . . . k . . . . Thus, in accordance with the central phasing concept of the aforesaid application, the pilot signal received by one of the elements, 0, called the reference element, is used to generate the phase reference φ o . The phase conjugation circuit PCC-1 associated with the first antenna element 1 is located at, i.e. is electrically close to, this reference element 0. The phase conjugation circuit PCC-2 for the element 2 is located at the first element 1, and so forth to the kth element and beyond to the end of the array. Each phase conjugation circuit is connected to its associated element by a non-dispersive transmission line. The box 11 labeled NODE ASSY 1 is an assembly that contains all the circuits located close to antenna element 1 including the phase conjugation circuit for antenna element 2 (not shown). Each node assembly contains such diplexing apparatus DIPLX as is necessary to couple signals into and out of the transmission lines and a phase reference regenerator (PRR) to provide the reference φ o to each of a plurality of PCCs each of which is connected to a NODE 1 and is labeled PCC-2 because it is connected to an array element in a second level of the tree structure. From this it is apparent that the reference element 0 is connected to a plurality of PCCs (each labeled PCC-1) at a NODE 0, each PCC-1 being connected to an element 1 through a node assembly which in turn has a plurality of PCCs (each labeled PCC-2) connected to a NODE 1. Each PCC-2 at this level is connected to an element 2 (not shown) at the next level through a node assembly. The tree structure is extended until each element of the array is connected to a node assembly. This tree structure thus references all PCCs to the element 0 either directly (as for a PCC-1 shown) or indirectly (as for a PCC-2 shown). By locating the phase conjugation circuit PCC-1 for the first element 1 at the node 0, the phase of the conjugated signal transmitted from the first element 1 is independent of the phase delay of the transmission line between the node assembly for the first element 1 (i.e., NODE ASSY 1) and its phase conjugation circuit PCC-1. If the transmission line phase delay is ωt 10 , then the phase of the input to PCC-1 is ω(t-t 1 -t 10 ). Therefore, by our definition of phase conjugation above, the phase of the output of PCC-1 is ω'(t+t 1 +t 10 )+θ o . This signal is retransmitted down the same transmission line to element 1. Since the line is non-dispersive, the retransmission phase delay exactly cancels the +ω't 10 term in the conjugated signal. Thus, the phase of the signal transmitted by the first element 1 is φ'(t+t 1 )+θ o , which is exactly what it would be if the first phase conjugation circuit PCC-1 were located at the first element 1 instead of the zeroth element and supplied with the correct phase reference. Moving on to an element 2 (not shown) at the next level, in order for the phase conjugation circuit PCC-2 to conjugate the phase of the pilot signal received by the second element via its node assembly, that phase conjugation circuit PCC-2 must be supplied with exactly the same phase reference as was the first element's phase conjugation circuit PCC-1. That phase reference is contained in the conjugate signal returned to the first element as the phase offset θ o . In order to extract this reference φ o , the conjugate signal is combined with the pilot signal in a phase reference regenerator which supplies the phase reference to the phase conjugation circuits for the second level of elements. In the same way, the phase reference regenerator at each second level element supplies the phase reference to the third level phase conjugation circuit PCC-3 and so on. Since each phase conjugation circuit receives the correct phase reference, φ o , it can conjugate the pilot signal received by its associated element correctly. Moreover, as in the case of the first level elements, the accuracy of phase conjugation at any element is independent of the phase delay of the transmission line between that element and its associated phase conjugation circuit. What has been described is a two-dimensional array of antenna elements connected in a tree configuration. In the "tree" analogy, the zeroth element is at the trunk (NODE 0) with several branches issuing from it. The two-dimensional arrangement is indicated in FIG. 1 by the arrows pointing to other PCCs fed in parallel by the NODE 0, and by each phase reference regenerator (PRR) in subsequent node assemblies. For a reasonable number of branches, the number of successive node assemblies required to connect all the elements of a large array is not large. As noted hereinbefore, if there are six branches at each node, then a tree with six levels of nodes connects 9,331 elements. The path from the reference element to any other element k in such an array intersects at most four phase reference regenerators. Thus, assuming each PCC independently contributes a uniform RMS phase error σ(φ), then the RMS cumulative phase error is a modest 4σ(φ). At the pilot source 10, a pilot transmitter 13 transmits a signal of angular frequency ω via a diplexer 14 and antenna 15, and a receiver 16 receives a signal of angular frequency ω' via the antenna and diplexer, where ω' is the angular frequency of the conjugate signal retrodirected from the antenna array. The received phase θ o is an arbitrary phase offset which must, however, be constant over the entire array, as noted hereinbefore. That is assured by the PCC associated with each array element. Before describing the organization and operation of each PCC with reference to FIG. 2, attention is again directed to the fact that the reference element 0 is connected at NODE 0 to each of the first level of PCCs designated PCC-1. A typical PCC of the first level receives the pilot signal of phase φ 1 and transmits the conjugate signal of phase φ 1 * through diplexers 17 and 18 of the node assembly to which the PCC is connected. Other PCCs at the same level will receive the pilot signal with a phase dependent upon its own position in the array. The two diplexers also feed a phase reference regenerator 19 which in turn feeds the phase reference φ o to the next level of PCCs. It should be noted that each PCC is associated with (belongs to) a separate node assembly. A diplexer is a reciprocal 3-port frequency electronic device which, in this application, works as follows. The signal of one frequency incident on port 1 is coupled to port 2, but not to port 3. Simultaneously, a signal at a different frequency incident on port 3 is coupled to port 1, but not to port 2. The purpose of the diplexer 17 is to allow a single antenna element to be used both for receiving the pilot signal from, and transmitting its conjugate to, the station from which the pilot signal emanated. The purpose of the diplexer 18 is to allow a single transmission line to be used to receive the phase conjugate φ 1 * from a remote PCC and to transmit the signal received from the array element to the PCC for that remote array element. The phase reference regenerator (PRR) 19 receives both the signal φ 1 and its phase conjugate φ 1 * to regenerate from the two signals the reference signal φ o which is fed to all PCCs of the next level connected to that node assembly. A preferred PRR will be described with reference to FIG. 3. Referring now to FIG. 2, the phase conjugation circuit (PCC) shown is assumed to be a PCC-1 located at the NODE 0 of the tree structure shown in FIG. 1, but it could be a PCC at any level of the tree structure. It is connected to its associated antenna array element by the transmission line connected to port 1 of a diplexer 20. It receives the pilot signal, whose phase is φ 1 , from that remote array element via that transmission line, and transmits the conjugate of that pilot signal (phase=φ 1 *) via that same transmission line back to that array element. It receives the phase reference signal (phase=φ o ) either directly or indirectly from the reference array element (labeled 0 in FIG. 1) of the array; directly if the PCC is located at NODE 0 connected to the reference element (e.g. PCC-1 in FIG. 1), indirectly (via a phase reference regenerator) if located at any of the lower echelon node assemblies (e.g. PCC-2). The pilot signal coupled out of port 2 of the diplexer is mixed in up-converter 21 comprised of a mixer M2 and bandpass filter BPF2, with a sample of voltage controlled oscillator (VCO) 22 output. The output of a mixer consists mainly of two components whose frequency and phase are equal to the sum and difference respectively of that of the inputs. The term "up-converter" implies the presence of a bandpass filter at the output of mixer M2 to pass the sum frequency while blocking the difference. This sum component, whose phase equals φ 1 +φ 1 * as indicated at 1 in the Phase Table, is fed to a "divide-by-2" circuit 23 whose phase is half that of its input, as indicated by 2 in the Phase Table in FIG. 2. The Phase Table indicates only the phase at designated points in the PCC because: the invention concerns the operation of a phase conjugator; and the frequency f of each signal is given by the same expression with f instead of φ; e.g. the frequency at 2 is (f 1 +f 1 *)/2. For this reason there is no need to use the "f∠φ" notation frequency seen in the literature. The divide-by-2 circuit is usually a flip-flop. Its output is mixed with the phase reference signal in a down-converter 24 comprised of a mixer M1 and bandpass filter BPF1. The output of mixer M1 is the difference frequency and phase of the two inputs. (See 3 in the Phase Table of FIG. 2). A sample of the VCO output is also fed to a "divide-by-n" circuit 25 where n is an integer≧4. This circuit is commonly made up of several flip-flops appropriately interconnected. As its name indicates, this circuit divides both the frequency and phase of its input by n. The outputs of the divide-by-n circuit and down-converter 24 are then fed to a phase detector 26 whose output is passed through a loop filter 27 (a low pass filter which may include a dc amplifier to increase loop gain) to provide the feedback control signal for the VCO. In steady state operation of the phase locked loop, the two input signals to the phase detector must have the same frequency and phase, i.e. 3 and 4 of the Phase Table must be equal. Solving that equation for φ 1 * gives ##EQU1## Since φ o is the same for all the elements of the array, so is the phase offset θ o =2Rφ o . Hence φ 1 * is the exact phase conjugate of φ 1 according to the definition given by Eq. (2) above. R is the frequency translation ratio. Since n≧4, it follows that 1<R≦2. The n≧4 condition is necessary to avoid "degenerate" operation of mixer M1; if n=3 the frequency at the 2 input to M1 is twice that of the reference signal, so that M1's lower sideband (difference frequency) output is equal to that of its reference signal input. This condition is to be avoided. For n=1 or 2 the circuit does not conjugate at all. This new PCC lends itself very well for use in a receiving array. All that would be needed is a clean-up loop between the reference element and the PCC-1s at NODE 0, so that the reference signal applied to these PCCs contains only the carrier phase, ω(t-r o /c), and no modulation. The phase detector 26 then serves as a demodulator whose output is fed to the data summer (through a delay distortion correcting processor if required) along with the data from the other PCC's. The new phase conjugate circuit thus receives a pilot signal at one frequency, f, and retrodirects a signal at a different frequency, f * , in order to provide input-output isolation. The different frequency is in exact phase conjugation, thus avoiding any "squint", and without mixer "degeneracy", which may cause large unpredictable phase errors. This advantage of avoiding mixer degeneracy distinguishes this new phase conjugate circuit from one of the PCCs disclosed in the aforesaid patent application in FIG. 4. In FIG. 2 of this application, both mixers, M1 and M2, are non-degenerate. The phase reference regenerator 19 of FIG. 1 may be implemented as shown in FIG. 3. This circuit avoids the mixer degeneracy problem which afflict the analogous circuits in the aforesaid application. It employs a most straight forward approach in recovering the phase reference φ o by the proper combination of the conjugate, φ 1 *=R(2φ o -φ 1 ), and the pilot signal, φ 1 , using three mixers M11, M12 and M13, instead of two because two signals of the same frequency can not be added in a single mixer without incurring degeneracy. The upper sideband would have the same frequency as the second harmonic of the strong signal if a single mixer were used. Instead the pilot signal is added to the output of mixer M11 in two stages, M12, and M13, in order to remove this "degeneracy." The first mixer M11 is part of a down-converter which includes a bandpass filter BPF11 for the difference between the reference φ o and φ 1 divided by two using a "divide-by-2" circuit 31 and a " divide-by-n" circuit 32 to obtain the two inputs to the mixer M11. The bandpass filter BPF11 is tuned to the difference φ o -1/2φ 1 . The pilot signal φ 1 divided by 4 in a circuit 33 is applied as a second input to the mixers M12 and M13 which are part of up-converters that include bandpass filters BPF12 and BPF13. One half of the phase 1/2φ 1 is added to the input of the mixer M12 and one half of the phase 1/2φ 1 is added in the second mixer, thus adding 1/2φ 1 to the output of the bandpass filter BPF11 to produce the exact reference φ o . While this phase reference regeneration circuit is described for extracting the phase reference to be used in the next PCC at the second level, it should be apparent that the circuit may be used for any level of PCCs. The PCC circuit disclosed may also be used at any level of the tree structure for centrally phased active retrodirective arrays. Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art and consequently, it is intended that the claims be interpreted to cover such modifications and equivalents.

An active retrodirective antenna array having central phasing from a reference antenna element through a "tree" structured network of transmission lines utilizes a plurality of phase conjugate circuits (PCCs) at each node and a phase reference regeneration circuit (PRR) at each node except the initial node. Each node virtually coincides with an element of the array. A PCC generates the exact conjugate phase φ* 1 of an incident signal φ 1 in accordance with the relation R (2φ 0 -φ 1 ) where R is equal to the reciprocal of 1-2/n, and n≧4, using a phase locked loop which combines the phases φ 1 and φ* 1 in an up-converter, divides the sum by 2 and mixes the result with the phase φ 0 in a down-converter for phase detection by the phase φ* 1 from the loop oscillator divided by n. The PRR extracts the phase φ 0 from the conjugate phase φ* 1 by mixing φ* 1 divided by 2 and divided by n in a down-converter and then mixing the phase φ 1 divided by 4 with the result of the down-converter in two cascaded up-converters. Both the PCC and the PRR are not only exact but also free from mixer degeneracy.

This application is a continuation of application Ser. No. 09/364,039, filed Jul. 30, 1999 (now U.S. Pat. No. 6,416,757), which is a continuation of application Ser. No. 08/823,893, filed Mar. 17, 1997 (now U.S. Pat. No. 5,959,087), which is a continuation of application Ser. No. 08/344,133, filed Nov. 23, 1994 (now U.S. Pat. No. 5,644,034), which is a continuation-in-part of application Ser. No. 07/828,956, filed Feb. 18, 1992 (now abandoned), which is a national phase filing of PCT/AU90/00337, filed Aug. 7, 1990, and published, in English, as International Publication No. WO 91/02078 on Feb. 21, 1991, designating the United States, which claims the benefit of Australian applications AU PJ5662, filed Aug. 7, 1989, and AU PJ7576, filed Nov. 24, 1989, the disclosures of which are incorporated herein by reference in their entirety. FIELD OF THE INVENTION The present invention relates to ligands which bind to human tumour necrosis factor alpha (TNF) in a manner such that upon binding the biological activity of TNF is modified. The type of modification shown here is distinct from previous descriptions of antibodies which bind to TNF alpha and inhibit all TNF alpha activity. The new discovery shows how the different activities of TNF alpha can be selectively inhibited or enhanced. In addition, the present invention relates to a composition comprising a molecule bound to TNF and to methods of therapy utilising TNF and molecules active against TNF. BACKGROUND OF THE INVENTION Tumor necrosis factor alpha (TNF) is a product of activated macrophages first observed in the serum of experimental animals presensitized with Bacillus Calmette - Guerin or Corynebacterium parvum and challenged with endotoxin (LPS). Following the systematic administration of TNF haemorrhagic necrosis was observed in some transplantable tumours of mice while in vitro TNF caused cytolytic or cytostatic effects on tumour cell lines. In addition to its host-protective effect, TNF has been implicated as the causative agent of pathological changes in septicemia, cachexia and cerebral malaria. Passive immunization of mice with a polyclonal rabbit serum against TNF has been shown to protect mice against the lethal effects of LPS endotoxin, the initiating agent of toxic shock, when administered prior to infection. The gene encoding TNF has been cloned allowing the usefulness of this monokine as a potential cancer therapy agent to be assessed. While TNF infusion into cancer patients in stage 1 clinical trials has resulted in tumour regression, side-effects such as thrombocytopaenia, lymphocytopaenia, hepatotoxicity, renal impairment and hypertension have also been reported. These quite significant side-effects associated with the clinical use of TNF are predictable in view of the many known effects of TNF, some of which are listed in Table 1. TABLE 1 BIOLOGICAL ACTIVITIES OF TNF -ANTI-TUMOUR -ANTI-VIRAL -ANTI-PARASITE FUNCTION cytotoxic action on tumour cells pyrogenic activity angiogenic activity inhibition of lipoprotein lipase activation of neutrophils osteoclast activation induction of endothelial, monocyte and tumour cell procoagulant activity induction of surface antigens on endothelial cells induction of IL-6 induction of c-myc and c-fos induction of EGF receptor induction of IL-1 induction of TNF synthesis induction of GM-CSF synthesis increased prostaglandin and collagenase synthesis induction of acute phase protein C3 Of particular importance is the activation of coagulation which occurs as a consequence of TNF activation of endothelium and also peripheral blood monocytes. Disseminated intravascular coagulation is associated with toxic shock and many cancers including gastro-intestinal cancer, cancer of the pancreas, prostate, lung, breast and ovary, melanoma, acute leukaemia, myeloma, myeloproliferative syndrome and myeloblastic leukaemia. Clearly modifications of TNF activity such that tumour regression activity remains intact but other undesirable effects such as activation of coagulation are removed or masked would lead to a more advantageous cancer therapy, while complete abrogation of TNF activity is sought for successful treatment of toxic shock. Segregation of hormonal activity through the use of site-specific antibodies (both polyclonal and monoclonal) can result in enhanced hormonal activity (Aston et al, 1989, Mol. Immunol. 26, 435). To date few attempts have been made to assign antigenicity or function to particular regions of the TNF molecule for which the three-dimensional structure is now known. Assignment of function to such regions would permit the development of MAbs and other ligands of therapeutic use. Polyclonal antibodies to amino acids 1 to 15 have been reported to block Hela R19 cell receptor binding by TNF (Socher et al, 1987, PNAS 84, 6829) whilst monoclonal antibodies recognising undefined conformational epitopes on TNF have been-shown to inhibit TNF cytotoxicity in vitro (Bringman and Aggarwal, 1987, Hybridoma 6, 489). However, the effects of these antibodies on other TNF activities is unknown. SUMMARY OF THE PRESENT INVENTION The present inventors have produced panels of monoclonal antibodies active against human TNF and have characterised them with respect to their effects on the anti-tumour effect of TNF (both in vitro and in vivo), TNF receptor binding, activation of coagulation (both in vitro and in vivo) and defined their topographic specificities. This approach has led the inventors to show that different topographic regions of TNF alpha are associated with different activities. Therefore the inventors enable the identification of antibodies or ligands which selectively enhance or inhibit TNF alpha activity, thereby providing for improved therapeutic agents and regimes including TNF alpha. In a first aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the following biological activities of the TNF are inhibited: 1. Tumour regression; 2. Induction of endothelial procoagulant; 3. Induction of tumour fibrin deposition; 4. Cytotoxicity; and 5. Receptor binding. In a preferred embodiment of all aspects the present invention the ligand is selected from the group consisting of antibodies, F(ab) fragments, restructured antibodies (CDR grafted humanised antibodies) single domain antibodies (dAbs), single chain antibodies, serum binding proteins, receptors and natural inhibitors. The ligand may also be a protein or peptide which has been synthesised and which is analogous to one of the foregoing fragments. However, it is presently preferred that the ligand is a monoclonal antibody or F(ab) fragment thereof. In a second aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterized in that when it binds to TNF the induction of endothelial procoagulant, tumour regression, induction of tumour fibrin deposition, cytotoxicity and receptor binding activities of the TNF are inhibited, the ligand binding to the TNF such that the epitope of the TNF defined by the topographic regions of residues 1-18, 58-65, 115-125 and 138-149, or the topographic region of residues 1-18, 108-128, or the topographic region of residues 56-79, 110-127 and 135-155 is substantially prevented from binding to naturally occurring biologically active ligands. In a third aspect the present invention consists in a ligand which binds to human TNF in at least two regions selected from the group consisting predominantly of the topographic region of residues 1-20, the topographic region of residues 56-77, the topographic region of residues 108-127 and the topographic region of residues 138-149. In a preferred embodiment of the third aspect of the present invention the ligand binds to human TNF in the topographic regions of residues 1-18, 58-65, 115-125 and 138-149. Such sequence regions are topographically represented in FIG. 23 . In a further preferred embodiment of the third aspect of the present invention the ligand binds to human TNF in the topographic regions of residues 1-18 and 108-128. Such sequence regions are topographically represented in FIG. 24 . In a further preferred embodiment of the second aspect of the present invention the ligand binds to human TNF in the topographic regions of residues 56-79, 110-127 and 136-155. Such sequence regions are topographically represented in FIG. 25 . In a particularly preferred embodiment of the first, second and third aspects of the present invention the ligand is a monoclonal antibody selected from the group consisting of the monoclonal antibodies designated MAb 1, MAb, 47 and MAb 54. Samples of the hybridoma cell lines which produce MAb 1, MAb 54 and MAb 47 have been deposited with the European Collection of Animal Cell Cultures (ECACC), Vaccine Research and Production Laboratory, Public Health Laboratory Service, Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wiltshire SP4 OJG, United Kingdom. MAb 1 was deposited on Aug. 3, 1989 and accorded accession No. 89080301; MAb 54 was deposited on Aug. 31, 1989 and accorded accession No. 89083103; MAb 47 was deposited on Dec. 14, 1989 and accorded accession No. 89121402. In a fourth aspect the present invention consists in a composition comprising TNF in combination with the ligand of the first, second or third aspect of the present invention, characterised in that the ligand is bound to the TNF. In a fifth aspect the present invention consists in a method of treating toxic shock comprising administering either the ligand of the first, second or third aspect of the present invention or the composition of the fourth aspect of the present invention. In a sixth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the induction of endothelial procoagulant activity of the TNF is inhibited; binding of TNF to receptors on endothelial cells is inhibited; the induction of tumour fibrin deposition and tumour regression activities of the TNF are enhanced; the cytotoxicity is unaffected and tumour receptor binding activities of the TNF are unaffected or enhanced. In a seventh aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterized in that when it binds to TNF the induction of endothelial procoagulant activity of the TNF is inhibited; the binding of the TNF to receptors on endothelial cells is inhibited, the induction of tumour fibrin deposition and tumour regression activities of the TNF are enhanced; and the cytotoxicity and receptor binding activities of the TNF are unaffected; the ligand binding to the TNF such that the epitope of the TNF defined by the topographic regions of residues 1-30, 117-128 and 141-153 is substantially prevented from binding to naturally occurring biologically active ligands. In an eighth aspect the present invention consists of a ligand which binds to human TNF in the topographic regions of residues 1-30, 117-128 and 141-153. In a preferred embodiment of the eighth aspect of the present invention the ligand binds to human TNF in the topographic regions of residues 1-26, 117-128 and 141-153. Such sequence regions are topographically represented in FIG. 26 . In a preferred embodiment of the sixth, seventh and eighth aspects of the present invention the ligand is the monoclonal antibody designated MAb 32. A sample of the hybridoma producing MAb 32 was deposited with The European Collection of Animal Cell Cultures (ECACC), Vaccine Research and Production Laboratory, Public Health Laboratory Service, Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wiltshire SP4 OJG, United Kingdom on Aug. 3, 1989 and was accorded accession No. 89080302 under the terms and conditions of the Budapest Treaty for the Deposit of Microorganisms for Patent process. In a ninth aspect the present invention consists in a composition comprising TNF in combination with a ligand of the sixth, seventh or eighth aspects of the present invention characterised in that the ligand is bound to TNF. No previous documentation of administering MAbs with TNF in order to modify activity of the administered cytokine exists. In a tenth aspect the present invention consists in a method of treating tumours the growth of which is inhibited by TNF, comprising administering either the ligand of the sixth, seventh or eighth aspects of the present invention or the composition of the ninth aspect of the present invention. In an eleventh aspect the present invention consists in a ligand which binds to residues 1-18 of human TNF (peptide 301). In a twelfth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterized in that when it binds to TNF the induction of endothelial procoagulant activity of the TNF is inhibited; the binding of TNF to receptors on endothelial cells is inhibited; the induction of tumour fibrin deposition and tumour regression activities of the TNF are enhanced; the cytotoxicity of the TNF are unaffected and tumour receptor binding activities of the TNF are unaffected or enhanced, the ligand binding to TNF such that the epitope of the TNF defined by the topographic region of residues 1-18 is substantially prevented from binding to naturally occurring biologically active ligands. In a thirteenth aspect the present invention consists in a composition comprising TNF in combination with a ligand of the eleventh or twelfth aspects of the present invention characterized in that the ligand is bound to the TNF. In a fourteenth aspect the present invention consists in a method of treating tumours the growth of which is inhibited by TNF, comprising administering either the ligand of the eleventh or twelfth aspect of the present invention or the composition of the thirteenth aspect of the present invention. In a fifteenth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the cytotoxicity and tumour regression activities of the TNF are unaffected; the induction of endothelial procoagulant and induction of tumour fibrin deposition activities of the TNF are inhibited and receptor binding activities of the TNF are unaffected. In a sixteenth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterized in that when it binds to TNF the cytotoxicity and tumour regression activities of the TNF are unaffected; the induction of endothelial procoagulant and induction of tumour fibrin deposition activities of the TNF are inhibited and the tumour receptor binding activities of the TNF are unaffected, the ligand binding to TNF such that the epitope of the TNF defined by the topographic regions of residues 22-40, 49-97, 110-127 and 136-153 is substantially prevented from binding to naturally occurring biologically active ligands. In a seventeenth aspect the present invention consists in a ligand which binds to human TNF in the topagraphic regions of residues 22-40, 49-97, 110-127 and 136-153. Such sequence regions are topographically represented in FIG. 27 . In a preferred embodiment of the seventeenth aspect of the present invention the ligand binds to human TNF in the topographic regions of residues 22-40, 49-96, 110-127 and 136-153. These regions being proximate in the 3D structure of TNF alpha. In a preferred embodiment of the fifteenth, sixteenth and seventeenth aspects of the present invention the ligand is the monoclonal antibody designated MAb 42. A sample of the hybridoma cell line producing MAb 42 was deposited with The European Collection of Animal Cell Cultures (ECACC), Vaccine Research and Production Laboratory, Public Health Laboratory Service, Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wiltshire SP4 OJG, United Kingdom on Aug. 3, 1989 and was accorded accession No. 89080304. In an eighteenth aspect the present invention consists in a composition comprising TNF in combination with the ligand of the fifteenth, sixteenth or seventeenth aspects of the present invention, characterised in that the ligand is bound to the TNF. In a nineteenth aspect the present invention consists in a method of treating tumours inhibited by the action of TNF comprising administering the ligand of the fifteenth, sixteenth or seventeenth aspects of the present invention or the composition of the eighteenth aspect of the present invention. In a twentieth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the tumour fibrin deposition activity of the TNF is enhanced; the induction of endothelial procoagulant activity of the TNF is unaffected and the cytotoxicity, tumour regression and receptor binding activities of the TNF are inhibited. In a twenty-first aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterized in that when it binds to TNF the tumour fibrin deposition activity of the TNF is enhanced; the induction of endothelial procoagulant activity of the TNF is unaffected and the cytotoxicity, tumour regression and tumour receptor binding activities of the TNF are inhibited, the ligand binding to TNF such that the epitope of the TNF defined by the topographic regions of residues 12-22, 36-45, 96-105 and 132-157 is substantially prevented from binding to naturally occurring biologically active ligands. In a twenty-second aspect the present invention consists in a ligand which binds to human TNF in the topographic regions of residues 12-22, 36-45, 96-105 and 132-157. These regions are proximate in the 3D structure of TNF and are topographically represented in FIG. 28 . In a preferred embodiment of the twentieth, twenty-first and twenty-second aspects of the present invention the ligand is the monoclonal antibody designated MAb 25. A sample of the hybridoma cell line producing MAb 25 was deposited with the European Collection of Animal Cell Cultures (ECACC), Vaccine Research and Production Laboratory, Public Health Laboratory Service, Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wiltshire SP4 OJG, United Kingdom on Dec. 14, 1989 and was accorded accession No. 89121401. In a twenty-third aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the tumour fibrin deposition activity of the TNF is enhanced and the cytotoxicity, tumour regression, induction of endothelial procoagulant and receptor binding activities of the TNF are inhibited. In a twenty-fourth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterized in that when it binds to TNF the tumour fibrin deposition activity of the TNF is enhanced and the cytotoxicity, tumour regression, induction of endothelial procoagulant and tumour receptor binding activities of the TNF are inhibited, the ligand binding to the TNF such that the epitope of the TNF defined by the topographic regions of residues 1-20 and 76-90 is substantially prevented from binding to naturally occurring biologically active ligands. In a twenty-fifth aspect the present invention consists in a ligand which binds to human TNF in the topographic regions of residues 1-20 and 76-90. These regions are proximate in the 3D structure of TNF and are topographically represented in FIG. 29 . In a preferred embodiment of the twenty-fifth aspect of the present invention the ligand binds to TNF in the topographic regions of residues 1-18 and 76-90. In a preferred embodiment of the twenty-third, twenty-fourth and twenty-fifth aspects of the present invention the ligand is the monoclonal antibody designated MAb 21. A sample of the hybridoma cell line producing MAb 21 was deposited with the European Collection of Animal Cell Cultures (ECACC), Vaccine Research and Production Laboratory, Public Health Laboratory Service, Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wiltshire SP4 OJG, United Kingdom on Jan. 25, 1990 and was accorded accession No. 90012432. In a twenty-sixth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the fibrin deposition activity of the TNF is unaffected and the cytotoxicity, tumour regression, induction of endothelial procoagulant and tumour receptor binding activities of the TNF are inhibited. In a twenty-seventh aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterized in that when it binds to TNF the tumour fibrin deposition activity of the TNF is unaffected and the cytotoxicity, tumour regression, induction of endothelial procoagulant and receptor binding activities of the TNF are inhibited, the ligand binding to the TNF such that the epitope of the TNF defined by the topographic regions of residues 22-40, 69-97, 105-128 and 135-155 is substantially prevented from binding to naturally occurring biologically active ligands. In a twenty-eighth aspect the present invention consists in a ligand which binds to human TNF in the topographic regions of residues 22-40, 69-97, 105-128 and 135-155. These regions are proximate in the 3D structure of TNF and are topographically represented in FIG. 30 . In a preferred embodiment of the twenty-sixth, twenty-seventh and twenty-eighth aspects of the present invention the ligand is the monoclonal antibody designated MAb 53. A sample of the hybridoma cell line producing MAb 53 was deposited with the European Collection of Animal Cell Cultures (ECACC), Vaccine Research and Production Laboratory, Public Health Laboratory Service, Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wiltshire SP4 OJG, United Kingdom on Jan. 25, 1990 and was accorded accession No. 90012433. In a twenty-ninth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to the TNF tumour fibrin deposition, induction of endothelial procoagulant, cytotoxicity, tumour regression and receptor binding activities of the TNF are unaffected. In a thirtieth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the tumour fibrin deposition, induction of endothelial procoagulant, cytotoxicity, tumour regression and receptor binding activities of the TNF are unaffected, the ligand binding to TNF such that the epitope of the TNF defined by the topographic regions of residues 22-31 and 146-157 is substantially prevented from binding to naturally occurring biologically active ligands. In a thirty-first aspect the present invention consists in a ligand which binds to human TNF in the topographic regions of residues 22-31 and 146-157. These regions are proximate in the 3D structure of TNF and are typographically represented in FIG. 31 . In a preferred embodiment of the twenty-ninth, thirtieth and thirty-first aspects of the present invention the ligand is the monoclonal antibody designated MAb 37. A sample of the hybridoma cell line producing MAb 37 was deposited with the European Collection of Animal Call Cultures (ECACC), Vaccine Research and Production Laboratory, Public Health Laboratory Service, Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wiltshire SP4 OJG, United Kingdom on Aug. 3, 1989 and was accorded accession No. 89080303. In a thirty-second aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the induction of endothelial procoagulant activity of the TNF is unaffected and the cytotoxicity, tumour regression, tumour fibrin deposition, and receptor binding activities of the TNF are inhibited. In a thirty-third aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the induction of endothelial procoagulant activity of the TNF is unaffected and the cytotoxicity, tumour regression, tumour fibrin deposition and receptor binding activities of the TNF are inhibited, the ligand binding to the TNF such that the epitope of the TNF defined by the topographic regions of residues 22-40 and 49-98 is substantially prevented from binding to naturally occurring biologically active ligands. In a thirty-fourth aspect the present invention consists in a ligand which binds to human TNF in at least one of the regions selected from the group consisting of the topographic region of residues 22-40, the topographic region of residues 49-98 and the topographic region of residues 69-97. In a preferred embodiment of the thirty-fourth aspect of the present invention the ligand binds to human TNF in the topographical region of residues 49-98. This region is topographically represented in FIG. 32 . In a further preferred embodiment of the thirty-fourth aspect of the present invention the ligand binds to human TNF in the topographic regions of residues 22-40 and 70-87. These regions are proximate in the 3D structure of TNF and are topographically represented in FIG. 33 . In a preferred embodiment of the thirty-second, thirty-third and thirty-fourth aspects of the present invention the ligand is monoclonal antibody MAb 11 or MAb 12. In a thirty-fifth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the induction of endothelial procoagulant activity of the TNF is inhibited. In a thirty-sixth aspect the present invention consists in a ligand capable of binding to human TNF, the ligand being characterised in that when it binds to TNF the induction of endothelial procoagulant activity of the TNF is inhibited, the ligand binding to TNF such that the epitope of the TNF defined by the topographical region of residues 108-128 is prevented from binding to naturally occurring biologically active ligands. In a thirty-seventh aspect the present invention consists in a ligand which binds to human TNF in the topographical region of residues 108-128. In a preferred embodiment of the thirty-fifth, thirty-sixth and thirty-seventh aspects of the present invention the ligand is selected from the group consisting of monoclonal antibodies designated MAb 1, MAb 32, MAb 42, MAb 47, MAb 53 and MAb 54. The biological activities of TNF referred to herein by the terms “Tumour Regression”, “Induction of Endothelial Procoagulant”, “Induction of Tumour Fibrin Deposition”, “Cytotoxicity” and “Receptor Binding” are to be determined by the methods described below. The term “single domain antibodies” as used herein is used to denote those antibody fragments such as described in Ward et al (Nature, Vol. 341, 1989, 544-546) as suggested by these authors. In order that the nature of the present invention may be more clearly understood, preferred forms thereof will now be described with reference to the following example and accompanying figures in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the results of a titration assay with MAb 1 against TNF; FIG. 2 shows TNF MAb 1 scatchard plot and affinity determination; FIG. 3 shows the effect of anti-TNF monoclonal antibodies 1 and 32 on TNF cytotoxicity in WEHI-164 cells; FIG. 4 shows the effect of MAb 1 on TNF-induced regression of a Meth A solid tumour; FIG. 5 shows the effect of MAbs 1 and 25 on TNF-induced Meth A Ascites tumour regression; FIG. 6 shows the effect of anti-TNF MAbs on induction of endothelial cell procoagulant activity by TNF; FIGS. 7 a , 7 b and 7 c shows incorporation of labelled fibrinogen into tumours of tumour-bearing mice and the effect of anti-TNF MAbs; FIG. 8 is a schematic representation of epitopes on TNF; FIG. 9 shows the effect of anti-TNF MAbs on TNF-induced regression of WEHI-164 tumours; FIGS. 10 a and 10 b shows the enhancement of TNF regression activity by MAb 32 in two experiments; FIGS. 11 a and 11 b shows the enhancement of TNF-induced tumour regression by MAb 32—dose response at day 1 and day 2; FIG. 12 shows binding of radio labelled TNF to receptors on bovine aortic endothelial cells; FIG. 13 shows receptor binding studies of TNF complexed with MAb 32 () control antibody () and MAb 47 () on melanoma cell line MM418E; FIG. 14 shows receptor binding studies of TNF complexed with MAb 32 () control antibody () and MAb 47 () on melanoma cell line IGR3; FIG. 15 shows receptor binding studies of TNF complexed with MAb 32 () control antibody () and MAb 47 () on bladder carcinoma cell line 5637; FIG. 16 shows receptor binding studies of TNF complexed with MAb 32 (), control antibody () and MAb 47 () on breast carcinoma cell line MCF7; FIG. 17 shows receptor binding studies of TNF complexed with MAb 32 () control antibody () and MAb47 () on colon carcinoma cell line B10; FIG. 18 shows the effect on TNF-mediated tumour regression in vivo by MAb 32 () control MAb () and MAb 47 (*); FIG. 19 shows the effect on TNF-mediated tumour regression in vivo by control MAb, MAb 32 and univalent FAb′ fragments of MAb 32; FIG. 20 shows the effect on TNF induced tumour regression by control MAb (), MAb 32 () and peptide 301 antiserum (); FIGS. 21 a , 21 b and 21 c show MAb 32 reactivity with overlapping peptides of 10 AA length; and FIG. 22 shows a schematic three dimensional representation of the TNF molecule. FIG. 23 shows topographically the region of residues 1-20, 56-77, 108-127 and 138-149; FIG. 24 shows topographically the region of residues 1-18 and 108 -128; FIG. 25 shows topographically the region of residues 56-79, 110-127 and 136-155; FIG. 26 shows topographically the region of residues 1-26, 117-128 and 141-153; FIG. 27 shows topographically the region of residues 22-40, 49-97, 110-127 and 136-153; FIG. 28 shows topographically the region of residues 12-22, 36-45, 96-105 and 132-157; FIG. 29 shows topographically the region of residues 1-20 and 76-90; FIG. 30 shows topographically the region of residues 22-40, 69-97, 105-128 and 135-155; FIG. 31 shows topographically the region of residues 2-31 and 146-157; FIG. 32 shows topographically the region of residues 49-98; FIG. 33 shows topographically the region of residues 22-40 and 70-87; FIG. 34 shows results of an ELISA using samples containing varying levels of TNF; and FIG. 35 shows the effect of VHP3-VλA2 on anti-tumour activity of TNF. DESCRIPTION OF THE PREFERRED EMBODIMENTS Animals and Tumour Cell Lines In all experiments BALB/C female mice aged 10-12 weeks obtained from the CSIRO animal facility were used. Meth A solid tumour and Meth A ascites tumour cell lines were obtained from the laboratory of Dr. Lloyd J. Old (Sloan Kettering Cancer Centre) and the WEHI-164 fibrosarcoma line was obtained from Dr. Geeta Chauhdri (John Curtin School of Medical Research, Australian National University). Fusions and Production of Hybridomas Mice were immunised with 10 ug human recombinant TNF intra-peritoneally in Freund's complete adjuvant. One month later 10 ug TNF in Freund's incomplete adjuvant was administered. Six weeks later and four days prior to fusion selected mice were boosted with 10 ug TNF in PBS. Spleen cells from immune mice were fused with the myeloma Sp2/0 according to the procedure of Rathjen and Underwood (1986, Mol. Immunol. 23, 441). Cell lines found to secrete anti-TNF antibodies by radioimmunoassay were subcloned by limiting dilution on a feeder layer of mouse peritoneal macrophages. Antibody subclasses were determined by ELISA (Misotest, Commonwealth Serum Laboratories). Radioimmunoassay TNF was iodinated using lactoperoxidase according to standard procedures. Culture supernatants from hybridomas (50 ul) were incubated with 125I TNF (20,000 cpm in 50 ul) overnight at 4° C. before the addition of 100 ul Sac-Cel (donkey anti-mouse/rat immunoglobulins coated cellulose, Wellcome Diagnostics) and incubated for a further 20 minutes at room temperature (20° C.). Following this incubation 1 ml of PBS was added and the tubes centrifuged at 2,500 rpm for 5 minutes. The supernatant was decanted and the pellet counted for bound radioactivity. Antibody-Antibody Competition Assays The comparative specificites of the monoclonal antibodies were determined in competition assays using either immobilized antigen (LACT) or antibody (PACT) (Aston and Ivanyi, 1985, Pharmac. Therapeut. 27, 403). PACT Flexible microtitre trays were coated with monoclonal antibody (sodium sulphate precipitated globulins from mouse ascites fluid, 100 micrograms per ml in sodium bicarbonate buffer, 0.05M, pH 9.6) overnight at 4° C. prior to blocking non-specific binding sites with 1% bovine serum albumin in PBS (BSA/PBS). The binding of 125I TNF to immobilised antibody was determined in the presence of varying concentrations of a second anti-TNF monoclonal antibody. Antibody and TNF were added simultaneously and incubated for 24 hours prior to washing with PBS (4 times) and counting wells for bound radioactivity. 100% binding was determined in the absence of heterologous monoclonal antibody while 100% competition was determined in the presence of excess homologous monoclonal antibody. All dilutions were prepared in BSA/PBS. LACT The binding of protein A purified, radiolabelled monoclonal antibodies to TNF coated microtitre wells was determined in the presence of varying concentrations of a second monoclonal antibody. Microtitre plates were coated with TNF (50 micrograms per ml) as described above. Quantities of competing antibodies (50 microliters) were pre-incubated on plates for 4 hour at 4° C. prior to addition of 125I monoclonal antibody (30,000 cpm) for a further 24 hours. Binding of counts to wells was determined after four washes with PBS. 100% binding was determined in the absence of competing antibody while 100% competition was determined in the presence of excess unlabelled monoclonal antibody. WEHI-164 Cytotoxicity Assay Bioassay of recombinant TNF activity was performed according to Espevik and Nissen-Meyer (1986, J. Immunol. Methods 95, 99). The effect of the monoclonal antibody on TNF activity was determined by the addition of the monoclonal antibody to cell cultures at ABT90. Tumour Regression Experiments Modulation of TNF-induced tumour regression activity by monoclonal antibodies was assessed in three tumour models: the subcutaneous tumours WEHI-164 and Meth A sarcoma and the ascitic Meth A tumour. Subcutaneous tumours were induced by the injection of approximately 5×10 5 cells. This produced tumours of between 10-15 mm approximately 14 days later. Mice were injected intra-peritoneally with human recombinant TNF (10 micrograms) plus monoclonal antibody (200 microliters ascites globulin) for four consecutive days. Control groups received injections of PBS alone or TNF plus monoclonal antibody against bovine growth hormone. At the commencement of each experiment tumour size was measured with calipers in the case of solid tumours or tumour-bearing animals weighed in the case of ascites mice. These measurements were taken daily throughout the course of the experiment. Radio-Receptor Assays WEHI-164 cells grown to confluency were scrape harvested and washed once with 1% BSA in Hank's balanced salt solution (HBSS, Gibco). 100 ul of unlabelled TNF (1-10,000 ng/tube) or monoclonal antibody (10 fold dilutions commencing 1 in 10 to 1 in 100,000 of ascitic globulin) wasadded to 50 ul 125I TNF (50,000 cpm). WEHI cells were then added (200 microliters containing 2×10 6 cells). This mixture was incubated in a shaking water bath at 37° C. for 3 hours. At the completion of this incubation 1 ml of HBSS was added and the cells spun at 16,000 rpm for 30 seconds. The supernatant was discarded s and bound 125I TNF in the cell pellet counted. All dilutions were prepared in HBSS containing 1% BSA. Procoagulant Induction by TNF on Endothelial Cells Bovine aortic endothelial cells (passage 10) were grown in RPMI-1640 containing 10% foetal calf serum (FCS), penicillin, streptomycin, and 2-mercaptoethanol at 37° C. in 5% CO 2 . For induction of procoagulant activity by TNF the cells were trypsinised and plated into 24-well Costar trays according to the protocol of Bevilacqua et al., 1986 (PNAS 83, 4533). TNF (0-500 units/culture) and monoclonal antibody (1 in 250 dilution of ascitic globulin) was added after washing of the confluent cell monolayer with HBSS. After 4 hours the cells were scrape harvested, frozen and sonicated. Total cellular procoagulant activity was determined by the recalcification time of normal donor platelet-poor plasma performed at 37° C., 100 microliters of citrated platelet-poor plasma was added to 100 ul of cell lysate and 100 ul of calcium chloride (30 mM) and the time taken for clot formation recorded. In some experiments tumour cell culture supernatant was added to endothelial cells treated with TNF and/or monoclonal antibody (final concentration of 1 in 2). Incorporation of 1251 Fibrinogen into Tumours of Mice Treated with TNF and Monoclonal Antibody In order to examine the effect of TNF and monoclonal antibodies on fibrin formation in vivo, BALB/c mice were injected subcutaneously with WEHI-164 cells (10 5 cells/animal). After 7-14 days, when tumours reached a size of approximately 1 cm in diameter, animals were injected intra-peritoneally with TNF (10 ug/animal) and 125I human fibrinogen (7.5 ug/animal, 122 uCi/mg Amersham) either alone or in the presence of monoclonal antibody to human TNF (200 ul/animal ascitic globulin). Monoclonal antibody against bovine growth hormone,was used as control monoclonal antibody. Two hours after TNF infusion incorporation of 125I fibrinogen into mouse tissue was determined by removing a piece of tissue, weighing it and counting the sample in a gamma counter. In all 13 monoclonal antibodies reacting with human TNF were isolated. These monoclonal antibodies were designated MAb 1, MAb 11, MAb 12, MAb 20, MAb 21, MAb 25, MAb 31, MAb 32, MAb 37, MAb 42, MAb 47, MAb 53 and MAb 54. The effect of these monoclonal antibodies on the bioactivity of human TNF is set out in Table 2. As can be seen from Table 2, whilst some monoclonal antibodies inhibit both anti-tumour activity and activation of coagulation by human TNF (MAb 1, 47 and 54) not all antibodies which inhibit the anti-tumour activity inhibit activation of coagulation either in vitro or in viva (MAb 11, 12, 25 and 53). Indeed MAb 21 which inhibited tumour regression enhanced the activation of coagulation in vivo. TABLE 2 EFFECT OF MONOCLONAL ANTIBODIES ON TNF BIOACTIVITY MONOCLONAL ANTIBODY TNF BIOACTIVITY 1 11 12 20 21 25 31 32 37 42 47 53 54 Cytotoxicity − − − 0 − − 0 0 0 0 − − − Tumour Regression − − − 0 − − 0 + 0 0 − − − Induction of − 0 0 − − 0 0 − 0 − − − − Procoagulant (Endothelial Fibrin Deposition − − − + + + + + 0 − − 0 − (tumour) Receptor Binding − − − 0 − − 0 +/ 0 0 − − − (WEHI - 164) 0* + Enhancement 0 No effect − Inhibition *Depending on MAb concentration in the case of WEHI-164 tumour cells and tumour type (see FIGS. 3, 13-17). MAbs 1, 47 and 54, which have been shown in competition binding studies to share an epitope on TNF, can be seen to have highly desirable characteristics in treatment of toxic shock and other conditions of bacterial, viral and parasitic infection where TNF levels are high requiring complete neutralisation of TNF. Other monoclonal antibodies such as MAb 32 are more appropriate as agents for coadministration with TNF during cancer therapy since they do not inhibit tumour regression but do inhibit activation of coagulation. This form of therapy is particularly indicated in conjunction with cytotoxic drugs used in cancer therapy which may potentiate activation of coagulation by TNF (e.g. vinblastin, acyclovir, IFN alpha, IL-2, actinomycin D, AZT, radiotherapy, adriamycin, mytomycin C, cytosine arabinoside, dounorubicin, cis-platin, vincristine, 5-flurouracil, bleomycin, (Watanabe N et al 1988 Immunopharmacol. Immunotoxicol. 10 117-127) or in diseases where at certain stages TNF levels are low (e.g. AIDS) and where individuals may have AIDS associated cancer e.g. Kaposi sarcoma, non-Hodgkins lymphoma and squamous cell carcinoma. Monoclonal antibody MAb 1 has been found to have the following characteristics: 1. Binds human recombinant TNF alpha, butnohua lymphotoxin (TNF beta) or human interferon. Similarly MAb 1 does not cross-react with recombinant murine TNF (FIG. 1 ). 2. MAb 1 is of the immunoglobulin type IgG1, K with an apparent affinity of 4.4×10 9 moles/liter (FIG. 2 ). 3. MAb neutralises the cytotoxic effect of recombinant human TNF on WEHI-164 mouse fibrosarcoma cells in culture. One microgram of MAb 1 neutralizes approximately 156.25 units of TNF In vitro (FIG. 3 ). 4. MAb 1 neutralises the tumour regression activity of TNF in the following mouse tumour models in vivo; WEHI-164 subcutaneous solid, tumour, the Meth A subcutaneous solid tumour and the Meth A ascites tumour (FIGS. 4, 5 and 9 ). 5. Mab1 prevents cerebral damage caused by human TNF in mice infected with malarial parasites. 6. In radioreceptor assays MAb 1 prevents binding of TNF to receptors on WEHI-164 cells (Table 3). 7. MAb 1 inhibits the induction of procoagulant activity (tissue factor) on cultured bovine aortic endothelial cells (FIG. 6 ). 8. MAb 1 reduces the uptake of 125I fibrinogen into tumours of mice treated with TNF (FIGS. 7 a-c ). 9. MAb 1 competes for binding of 125I TNF and thus shares an overlapping epitope with the following monoclonal antibodies: 21, 25, 32, 47, 54 and 37. 10. MAb 1 does not compete for binding of 125I TNF with the following monoclonal antibodies: 11, 12, 42, 53, 31 and 20 (FIG. 8 ). TABLE 3 RADIORECEPTOR ASSAY: INHIBITION OF TNF BINDING TO WEHI-164 CELLS BY MAb 1 TREATMENT % SPECIFIC BINDING MAb 1 1/10 0 1/100 21 1/1,000 49 1/10,000 73 1/100,000 105 cold TNF (ng/tube) 10,000 0 5,000 0 1,000 0 500 10 100 11 10 64 1 108 0 100 MAb 32 is an IgG2b, K antibody with an affinity for human TNF alpha of 8.77×10 9 moles/liter as determined by Scatchard analysis. This monoclonal antibody does not react with either human TNF beta (lymphotoxin) or mouse TNF alpha. As shown in FIG. 3 MAb 32 does not inhibit TNF cytotoxicity in vitro as determined in the WEHI-164 assay. Monoclonal antibody 32 variably enhances TNF-induced tumour regression activity against WEHI-164 fibrosarcoma tumours implanted subcutaneously into BALB/c mice at a TNF dose of 10 ug/day (see FIGS. 10 a and 11 a-b ). This feature is not common to all monoclonal antibodies directed against TNF (FIG. 9) but resides within the binding site specificity of MAb 32 (FIG. 8) which may allow greater receptor mediated uptake of TNF into tumour cells (see Table 4). TABLE 4 BINDING OF TNF TO RECEPTORS ON WEHI-164 CELLS IN THE PRESENCE OF MAb 32 % BINDING 125 I-TNF MAB DILUTION CONTROL MAB MAB 32 1/10 36 141 1/100 74 88 1/1000 101 83 1/10,000 92 82 1/100,000 97 93 Enhancement of TNF activity by MAb 32 at lower doses of TNF is such that at least tenfold less TNF is required to achieve the same degree of tumour regression (see FIGS. 11 and 18 ). The results for day 1, 2.5 ug and 1 ug TNF and day 2, 5 ug, 2.5 ug and lug are statistically significant in a t-test at p<0.01 level. This level of enhancement also increases the survival rate of recipients since the lower dose of TNF used is not toxic. FIG. 19 shows that univalent Fab fragments of MAb 32 also cause enhancement of TNF-induced tumour regression in the same manner as whole MAb 32 (see below). MAb 32 inhibits the expression of clotting factors on endothelial cells normally induced by incubation of the cultured cells with TNF (see FIG. 6 ). This response may be mediated by a previously unidentified TNF receptor which is distinct to the receptor found on other cells. Conversely, MAb 32 enhances the in vivo activation of coagulation within the tumour bed as shown by the incorporation of radiolabelled fibrinogen (FIGS. 7 a-c ). This may be due to activation of monocytes/macrophage procoagulant and may provide further insight into the mechanism of TNF-induced tumour regression. The results obtained with MAb 32 are shown in comparison to other anti-TNF MAbs in Table 2. The ability of MAb 32 and MAb 47 to inhibit the binding of TNF to endothelial cells was also assessed. Bovine aortic endothelial (BAE) cells (passage 11) were plated in 24-well culture dishes (Corning) which had been pre-coated with gelatin (0.2%) and grown to confluence in McCoys 5A (modified) medium supplemented with 20% foetal calf serum. For the radio-receptor assay all dilutions (of cold TNF and MAbs) were made in this medium. The BAE cells were incubated for one hour in the presence of either cold TNF (0 to 100 ng) or MAb (ascites globulins diluted 1/100 to 1/100,000) and iodinated TNF (50,000 cpm). At the end of this time the medium was withdrawn and the cells washed before being lysed with 1M sodium hydroxide. The cell lysate was then counted for bound radioactive TNF. Specific binding of labelled TNF to the cells was then determined. The results obtained in this assay with MAb 32, MAb 47 and a control MAb are set out in FIG. 12 . The results obtained in the clotting assay using BAE cells cultured in the presence of TNF and anti-TNF MAb correlate with the results obtained in the BAE radioreceptor assay i.e. MAbs which inhibit the induction of clotting factors on the surface of endothelial cells (as shown by the increase in clotting time compared to TNF alone) also inhibit the binding of TNF to its receptor. This is exemplified by MAbs 32 and 47. MAb 32, which does not inhibit TNF binding to WEHI-164 cells, does inhibit binding of TNF to endothelial cells. This result provides support for the hypothesis that distinct functional sites exist on the TNF molecule and that these sites interact with distinct receptor subpopulations on different cell types. Thus ligands which bind to defined regions of TNF are able to modify the biological effects of TNF by limiting its binding to particular receptor subtypes. As shown in FIG. 12 MAb 47 is a particularly potent inhibitor of TNF interaction with endothelial cells, the percentage specific binding at a dilution of 1/100 to 1/10,000 being effectively zero. Receptor Binding Studies of Human TNF Complexed with MAB 32 on Human Carcinoma Cell Lines In Vitro MAb 32 has been shown to enhance the anti-tumour activity of human TNF. The mechanisms behind the enhancement may include restriction of TNF binding to particular (tumour) receptor subtypes but not others (endothelial) with subsequent decrease in TNF toxicity to non-tumour cells. This mechanism does not require enhanced uptake of TNF by tumour cells in in vitro assays. In addition, MAb 32 also potentiates the binding of human TNF directly to TNF receptors on certain human carcinoma cell lines. Materials and Methods The following human carcinoma cell lines have been assayed for enhanced receptor-mediated uptake of TNF in the presence of MAb 32: B10, CaCo, HT 29, SKC01 (all colon carcinomas), 5637 (Bladder carcinoma), MM418E (melanoma), IGR3 (melanoma), MCF 7 (breast carcinoma). The cells were propagated in either RPMI-1640 (MM418E) DMEM (CaCo and IGR 3) or Iscoves modified DMEM (B10, HT 29, SK01, S637, MCF 7) supplemented with 10% foetal calf serum, penecillin/streptomycin and L-glutamine. Receptor assays were performed as previously described for endothelial cells except that the incubation time with iodinated TNF was extended to 3 hours for all but the B10 cells for which the radiolabel was incubated for 1 hour. Results Enhanced TNF uptake was observed in the presence of MAb32 by the melanoma cell lines tested MM418E and IGR 3 (FIGS. 13 and 14 ), the bladder carcinoma 5637 (FIG. 15 ), and the breast carcinoma MCF 7 (FIG. 16 ). MAb 32 did not affect TNF-receptor interaction in any ofthe other cell lines as shown by B 10 (FIG. 17) MAb 47, which has been shown to inhibit TNF binding to WEHI-164 cells and endothelial cells, and which also inhibits TNF-mediated tumour regression was found to markedly inhibit TNF binding to all the cell lines tested (FIGS. 13 - 17 ). Conclusions Receptor binding analyses have indicated a second mechanism whereby MAb 32 may potentiate the anti-tumour activity of TNF. This second pathway for enhancement of TNF results from increased uptake of TNF by tumour all receptors in the presence of MAb 32. Enhancement of TNF-Mediated Tumour Regression In Vivo by MAB 32 or Univalent FAB′ Fragments of MAB 32 Tumour regression studies were carried out as described above in mice carrying WEHI-164 subcutaneous tumours (N=5 animals/group). Tumour size was determined daily during the course of the experiment. The results obtained using MAb 32 are set out in FIG. 22 and show the mean +/−SD % change in tumour area at the completion of treatment (day 2) ( MAb 32: control MAb: *MAb 47). Differences observed between control MAb-TNF and MAb 32-TNF treated groups are statistically significant in a T-test at the p-<0.01 level. The results using the univalent FAb′ fragments of MAb 32 are shown in FIG. 19 . Tumour size was determined daily during the course of the experiment. The results show the mean SD% change in tumour area at the completion of treatment (day 2). Differences between the control MAb-10F and MAb 32-TNF treated groups are statistically significant in a T-test at the P-<0.01 level. TNF Induced Tumour Regression: Effect of Anti-Peptide 301 SERA FIG. 20 shows the percent change in tumour area in tumour-bearing mice treated for three days with TNF plus control MAb (antibody against bovine growth hormone), TNF plus MAb 32 or TNF plus antiserum (globulin fraction) against peptide 301. In an unpaired T-test the control group is significantly different from both of the test groups (MAb 32, antiserum 301) while the MAb 32 and peptide antiserum 301 groups are not significantly different from each other. (control vs MAb 32, p<0.002; control vs antipeptide 301, p<0.025). Thus antisera raised using a peptide which comprises part of the MAb 32 specificity, also causes TNF enhancement of tumour regression. As shown in FIG. 9 competition binding studies has shown that the thirteen monoclonal antibodies can be sub-divided into two main groups, namely MAbs 1, 21, 47, 54, 37, 32 and 25 and MAbs 11, 12, 53 and 42. Experiments were then conducted to identify-the regions on human TNF recognised by these monoclonal antibodies. Identification of Regions On Human TNF Recognised By Monoclonal Antibodies Methods 1. Overlapping peptides of 7 and 10 amino acid residues long were synthesized on polypropylene pins according to the method of Geysen et al., 1984, PNAS 81, 3998-4002. The overlap was of 6 and 9 residues respectively and collectively the peptides covered the entire TNF amino acid sequence. The peptides were tested for reactivity with the MAbs by ELISA. MAbs which had TNF reactivity absorbed from them by prior incubation with whole TNF were also tested for reactivity with the peptides and acted as a negative control. 2. Longer peptides of TNF were synthesized as described below. These peptides were used to raise antisera in sheep using the following protocol. Merino sheep were primed with TNF peptide conjugated to ovalbumin and emulsified in Freunds Complete adjuvant and boosted at 4 weekly intervals with peptide-ovalbumin and sera assayed for the presence of anti-TNF antibody by radioimmunoassay. Of the peptides shown only peptides 275, 301, 305, 306 and 307 elicited sera reacting with whole TNF. The positive sera were then used in competitive binding assays (PACT assays) with the MAbs. The following peptides were synthesised and are described using the conventional three letter code for each amino acid with the TNF sequence region indicated in brackets. Peptide 275 H-Ala-Lys-Pro-Trp-Tyr-Glu-Pro-Ile-Tyr-Leu-OH (111-120) Peptide 301 H-Val-Arg-Ser-Ser-Ser-Arg-Thr-Pro-Ser-Asp-Lys-Pro-Val-Ala-His-Val-Val-Ala-OH (1-18) Peptide 302 H-Leu-Arg-Asp-Asn-Gln-Leu-Val-Val-Pro-Ser-Glu-Gly-Leu-Tyr-Leu-Ile-OH (43-58) Peptide 304 H-Leu-Phe-Lys-Gly-Gln-Gly-Cys-Pro-Ser-Thr-His-Val-Leu-Leu-Thr-His-Thr-Ile-Ser-Arg-Ile-OH (63-83) Peptide 305 H-Leu-Ser-Ala-Glu-Ile-Asn-Arg-Pro-Asp-Tyr-Leu-Asp-Phe-Ala-Glu-Ser-Gly-Gln-Val-OH (132-150) Peptide 306 H-Val-Ala-His-Val-Val-Ala-Asn-Pro-Gln-Ala-Glu-Gly-Gln-Leu-OH (13-26) Peptide 307 H-Ala-Glu-Gly-Gln-Leu-Gln-Trp-Leu-Asn-Arg-Arg-Ala-Asn-Ala-Leu-Leu-Ala-Asn-Gly-OH (22-40) Peptide 308 H-Gly-Leu-Tyr-Leu-Ile-Tyr-Ser-Gln-Val-Leu-Phe-Lys-Gly-Gln-Gly-OH (54-68) Peptide 309 H-His-Val-Leu-Leu-Thr-His-Ile-Ser-Arg-Ile-Ala-Val-Ser-Tyr-Gln-Thr-Lys-Val-Asn-Leu-Leu-COOH (73-94) Peptide 323 H-Thr-Ile-Ser-Arg-Ile-Ala-Val-Ser-Tyr-Gln-Thr-COOH (79-89) These peptides were synthesised using the following general protocol. All peptide were synthesised using the Fmoc-polyamide method of solid phase peptide synthesis (Atherton et al, 1978, J.Chem.Soc.Chem.Commun., 13, 537-539). The solid resin used was PepSyn KA which is a polydimethylacrylamide gel on Kieselguhr support with 4-hydroxymethylphenoxy-acetic acid as the functionalised linker (Atherton et al., 1975, J.Am.Chem. Soc. 97, 6584-6585). The carboxy terminal amino acid was attached to the solid support by a DCC/DMAP-mediated symmetrical-anhydride esterificatidn. All Fmoc-groups were removed by piperidine/DMF wash and peptide bonds wereformed either via pentafluorophenyl active esters or directly by BOP/NMM/HOBt (Castro's reagent) (Fournier et al, 1989, Int.J.Peptide Protein Res., 33, 133-139) except for certain amino acids as specified in Table 5. Side chain protection chosen for the amino acids was removed concomittantly during cleavage with the exception of Acm on cysteine which was left on after synthesis. TABLE 5 Amino Acid Protecting Group Coupling Method Arg Mtr or Pmc Either Asp OBut Either Cys Acm (permanent) Either Glu OBut Either His Boc OPfp only Lys Boc Either Ser But BOP only Thr But BOP only Tyr But Either Trp none Either Asn none OPfp only Gln none OPfp only Cleavage and Purification Peptide 301, 302, 305 are cleaved from the resin with 95% TFA and 5% thioanisole (1.5 h) and purified on reverse phase C4 column, (Buffer A—0.1% aqueous TFA, Buffer B—80% ACN 20% A). Peptide 303, 304 are cleaved from the resin with 95% TFA and 5% phenol (5-6 h) and purified on reverse phase C4 column. (Buffers as above). Peptide 306, 308 are cleaved from the resin with 95% TFA and 5% water (1.5 h) and purified on reverse phase C4 column. (Buffers as above). Peptide 309 Peptide was cleaved from the resin with 95% TFA and 5% thioanisole and purified on reverse phase C4 column. (Buffers as above). Peptide 307 Peptide was cleaved from the resin with a mixture of 93% TFA, 3.1% Anisole, 2.97% Ethylmethylsulfide and 0.95% Ethanedithiol (3 h) and purified on reverse phase C4 column. (Buffers as above). Results Typical,results of MAb ELISA using the 7 and 10 mers are shown in FIGS. 21 a-c . Together with the results of PACT assats using the sheep anti-peptide sera (shown in Table 6) the following regions of TNF contain the binding sites of the anti-TNF MAbs. Mab 1: residues 1-18, 58-65, 115-125, 138-149 Mab 11: residues 49-98 Mab 12: residues 22-40, 70-87 Mab 21: residues 1-18, 76-90 Mab 25: residues 12-22, 36-45, 96-105, 132-157 Mab 32: residues 1-26, 117-128, 141-153 Mab 37; residues 22-31, 146-157 Mab 42: residues 22-40, 49-96, 110-127, 136-153 Mab 47: residues 1-18, 108-128 Mab 53: residues 22-40, 69-97, 105-128, 135-155 Mab 54: residues 56-79, 110-127, 136-155 TABLE 6 COMPETITIVE BINDING OF TNF BY ANTI-TNF MONO- CLONES IN THE PRESENCE OF ANTI PEPTIDE SERA MAB/PEPTIDE SERA 275 301 305 306 307 1 − + − − − 11 − +/− − − − 12 − + − − ++ 21 − ++ − − − 25 − + − − − 32 − ++++ + + − 37 − + +/− − + 47 − + − − − 53 − + − − + 54 − + − − − 42 − + + − + Note 1: − indicates no competition, + indicates slight competition at high concentration of anti-peptide antisera (1/50), ++++ indicates strong competition by anti-peptide sera equal to that of the homologous MAb. Note 2: Only peptide which elicited sera recognising whole TNF were used in this assay. As will be understood by persons skilled in this field the ligands of the present invention can be used in assays of biological fluids for detecting the presence of and quantifying the concentration of TNF in a sample. One means by which this may be achieved is by using the ligands of the present invention in conventional ELISAs. Set out below is an example of such an assay. TNF ELISA REAGENTS CARBONATE COATING BUFFER, pH 9.6 Na 2 CO 3 1.6 g Add 800 mL dH 2 O, pH to 9.6 NaHCO 3 2.9 g then make to 1 L with dH 2 O BLOCKING BUFFER BSA 1 g Add BSA to PBS and allow PBS 100 mL to dissolve fully before using. Store at 4° C. WASH BUFFER (0.05% Tween/PBS) Tween 20 0.5 g Add Tween to PBS and mix PBS 1 L thoroughly before use CITRATE BUFFER Citric Acid.  2.1 g in 50 mL Add solutions together 1H 2 O dH 2 O and adjust TriSodium 1.47 g in 50 mL pH to 4.0-4.2 Citrate 2H 2 O dH 2 O NB: All incubations can be carried out at 4° C. overnight OR at room temperature for 2 hrs OR at 37° C. for 1 hr. Method Coat ELISA plates with equal proportions of MAb1, MAb32 and MAb54 to human TNF in carbonate coating buffer. The total immunoglobulin concentration should be 20 μg/mL and 100 μL is added to each well. Cover plates and incubate. Wash plates 3× with PBS/Tween. Incubate plates with 250 μL/well blocking buffer Wash plates 3× with PBS/Tween. Add 100 μL sample or TNF standards, diluted in blocking buffer where required, to plates, then cover and incubate. Wash plates 3 × with PBS/Tween. Add 100 μL biotinylated antibody mix (equal proportions of biotinylated monoclonal antibodies 11 & 42 to human TNF) at a final concentration of 10 μg/mL in blocking buffer to each well, cover and incubate. Wash plates 3× with PBS/Tween. Add 100 μL/well streptavidin-peroxidase (Amersham product no. RPN 1231) at 1/2,000 in blocking buffer, then cover and incubate. Wash plates 3 × with PBS/Tween. Add 100 μL/well biotinylated anti-stretpavidin monoclonal antibody (Jackson Immunoresearch) at 1/40,000 in blocking buffer, cover and incubate. Wash plates 3 × with PBS/Tween. Add 100 μL/well streptavidin-peroxidase at 1/2,000 in blocking buffer, cover and incubate. Wash plates 3 × with PBS/Tween. Add 100 μL/well peroxidase substrate (ABTS) at 1 mg/mL in citrate buffer containing 0.3 μL/ml H 2 O 2 and leave to incubate at room temperature for up to 1 hour. NB: Substrate solution should be prepared immediately prior to use. Read absorbance at 405 nm, and compare sample readings with TNF standard curve to determine TNF levels. BIOTINYLATION OF IgG 50 mM BICARBONATE BUFFER, pH 8.5 Na 2 CO 3 1.6 g NaHCO 3 2.9 g In 1 L dH 2 O, adjust pH with HCl 0.1 PHOSPHATE BUFFER, pH 7.0 Method Prepare immunoglobulins by purifying on a protein A column, then freeze-drying. Reconstitute the immunoglobulins with 50 mM bicarbonate buffer to a concentration of 20 mg/mL in a clean glass test tube. Add 0.4 mg biotin per 20 mg Ig directly to the tube. Place the test tube on ice and incubate for 2 hours. Remove the unreacted biotin by centrifuging at 1000 g for 15-30 minutes in a Centricon-30 microconcentrator. Dilute the sample in 0.1 M phosphate buffer and repeat the centrifugration twice. Make the sample up to the original volume with phosphate buffer, add 0.1% NaN 3 and store at 4° C. until used. The results obtained in such an assay using samples containing known amounts of TNF is shown in FIG. 34 . As mentioned above the specific mouse monoclonal antibodies disclosed in this application can be humanised if required. A number of methods of obtaining humanised antibodies are set out in PCT/GB92/01755 (WO93/06213). A humanised version of MAb32 designated VHP3-VλA2 was produced by the method disclosed in PCT/GB92/01755. Briefly, this antibody was produced as follows: 1 Cloning and Display of the V Genes of MAb 32 on Phage The genes of the mouse MAb32 antibody (IgG2b, Kappa) were rescued by PCR essentially as described (Clackson et al., 1991, in “PCR: A Practical Approach” eds. M. J. McPherson et al., IRL Press, Oxford, pp 187-214) using the primers VH1BACk and VH1FOR2 for the VH gene and Vk2BACK and VK4FOR for the VL gene and the polymerase chain reaction (PCR, R. K. Saiki et al., 1985, Science 230, p1350). The mouse VH and Vk genes were assembled for expression as scFv fragments by PCR assembly (Clackson et al., supra) amplified with VH1BACKSfi and VFFOR4NOT and ligated into phagemid pHEN1 (H. R. Hoogenboom et al., 1991 Nucl. Acids. Res. 19 pp4133-4137) as a SfiI-NotI cut restriction fragment, and electroporated into E.coli HB2151 cells. Of 96 clones analysed by ELISA (see below), 9 secreted TNF-binding soluble scFv fragments. Sequencing revealed in all clones a mouse VH of family IIB and a mouse Vk of family VI (E. A. Kabat et al., 1991 Sequences of Proteins of Immunological Interest, US Public Health Services). Nucleotide mutations which were probably introduced by the PCR were detected by comparing the 9 sequences, and a clone with consensus sequence and binding activity (scFv-MAb32) chosen for further cloning experiments. Recloning of the MAb32 V-genes for soluble expression: The murine V-genes were recloned for soluble expression of heavy (Fd, VHCH1) or light chain, by linking the mouse V-genes to the human CH1 (of the mu-isotype) or human Ck gene respectively by splice overlap extension. The mouse Vk gene was amplified from scFv-MAb32 DNA with oligonucleotides MOJK1FORNX (binds in joining region of V-gene and MVKBASFI (binds in 5′ region and adds Sfil restriction site); the human Ck was obtained by PCR from a mouse-human chimaeric light chain gene (of NQ10.12.5, described in Hoogenboom et al., 1991 supra), with oligonucleotides MOVK-HUCK-BACK (binds in 5′ of human Ck and is partially complementary with mouse Jk 1 region) and HUCKNOT16NOMYC (sits in 3′ end of human Ck, retains the terminal cysteine, and tags on a NotI restriction site) as in Clackson et al., 1991 using a two fragment assembly. For linkage of the DNA fragments, the two PCR fragments were mixed and amplified with MVKBASFI and HUCKNOT16NOMYC. The chimaeric VkCk gene was subsequently cloned asa SfiI-NotI fragment in pUC19 derivative containing the pe1B signal peptide sequence and appropriate cloning sites for soluble expression of the light chain (pUC19-pe1B-myc). Similarly, the mouse VH gene (amplified from scFv-MAb32 with LMB3 and VH1FOR-2) was combined by splicing by overlap extension PCR with the human u-CH1 domain (amplified from human IgM-derived cDNA (Marks et al., 1991, supra; WO 92/01047) with Mo-VH-Ku-CH1 and HCM1FONO, and cloned as SfiI-NotI fragment into a pUC19-pe1B-myc for soluble expression of a tagged chain. Display of the MAb32 Antibody on Phage The chimaeric light chain was displayed on phage fd by reamplification of the mouse/human chimaeric chain with HUCKCYSNOT and MVKBAAPA and cloning into fd-tet-DOG1 as an ApaLI-NotI fragment. Cells harbouring a plasmid with the heavy Fd chain gene were grown in 2×TY containing AMP-GLU (1%) to logarithmic phase (OD600 of 0.5) and infected with a 20-fold excess of light-chain displaying phage. After 45 min at 37° C. without shaking and 45 min at 37° C. with shaking in the 2×TY, ampicillin (100 μg/ml). Glucose 1% medium, a sample was diluted into 50-fold volume of prewarmed (37° C.) 2×TY, ampicillin (100 μg/ml) and tetracyclin (15 μg/ml), grown for 1 hr at 37° C. and then overnight at 30° C. (shaking). Phage particles collected from the supernatant of such culture displayed TNF-binding Fab fragments anchored through the light chain on their surface. Similarly, the reversed configuration was made. The heavy chain VHCH1 fragment was cloned into fd-tet-DOG1 (after amplification of the Fd chain gene from the mouse/human chimeric construct with VH1BACKAPA and HCM1FONO), and phage used to infect cells capable of producing soluble light chain. Phage particles collected from the supernatant of such culture displayed TNF-binding Fab fragments anchored through the heavy chain VHCH1 fragment on their surface. Properties of MAb 32 fragments displayed on phage: The V-genes of the murine antibody MAb32 were cloned by amplifying the hybridoma V-genes, cloning the VH and Vk genes as scFv fragments in phagemid pHENl as above. Antibody scFv fragments which bind to TNF were identified by ELISA. The mouse VH gene was recloned in pUC19-pe1B-myc for soluble expression as a mouse VH linked to human mu-CH1, while the light chain was recloned with the human Ck domain in vector fd-tet-DOG1 as a fusion with g3p. When cells harbouring the heavy chain construct were infected with the fd-phage carrying the light chain, phage particles emerged which carried light chain-g3p associated with the fd heavy chain. Indeed, binding to TNF and the 301 peptide was retained, as judged by ELISA with phage displaying the mouse-human chimaeric Fab fragment. In the phage ELISA, the background signal of phage carrying the light chain only was a lightly higher than wild-type fd-tet-DOG1 phage, but always lower than the signal obtained with Fab-displaying phage. Similarly, TNF binding phage was made with the heavy chain VHCH1 fragment anchored on phage, and the light chain provided as a soluble fragment. Hence, MAb32 is functional in the dual combihatorial format in both display orientations. 2 Chain Shuffling by Epitope Imprinted Selection (EIS) Construction of One Chain-Libraries Kappa, lambda light chain and Mu-specific CDNA was made from the mRNA prepared from the peripheral blood lymphocytes from two healthy donors essentially as in Marks et al., 1991, supra. The first-strand CDNA synthesis was performed with oligonucleotides HCM1F0, HUCLCYS and HUCKCYS for Mu-specific, lambda and kappa libraries respectively. The VH-CH 1 repertoire was amplified from this cDNA with oligonucleotides HCM1OF and six family specific VHBACK primers (as in Marks et al., 1991, supra), reamplified with a NotI-tagged forward primer (HCM1FONO) and ApaLI tagged VHBACK primers (6 primers HuVH1BAAPA to HuVH6BAAPA). Similarly, the light chain repertoires were amplified with HUCLCYS or HUCKCYS forward primers and HUVλ1BACK to HuVλ6BACK or HuVk1BACK to HuVk6BACK back primers described in Marks et al., 1991, supra and PCT/GB91/01134 (WO 92/01047). In each case described in this section the lambda and kappa chain variable repertoires were amplified separately. The amplified repertoires were reamplified with ApaLI and NotI tagged versions of these oligonucleotides (13 back primers HuVλ1BAAPA to Huλ6BAAPA or HuVk1BAAPA to HuVkBAAPA and two forward primers HUCLCYSNOT and HuCKCYSNOT, respectively). All three repertoires were cloned into vector fd-tet-DOG1 as ApaLI-NotI fragments, and electroporated into E.coli MC1061 cells, to obtain libraries of 1.0×10 7 clones for VλCA, 1.4×10 6 clones for VkCk, and 5×10 6 clones for IgM-derived VHCH1. The presence of insert was checked and the frequency of inserts in the library found to be higher than 95% inall three cases. Selecting a Human VL using the Mouse VH Domain as Docking Chain In a first chain shuffling experiment, the mouse VH (linked to the human CH1 domain), expressed from pUC19-pe1B-myc, was paired as Fab fragment with a library of 10 7 different human VλCλ domains. Phage displaying the antibody fragments were subjected to rounds of panning on TNF-coated tubes. By following the titre of the eluted phage, the extent of selection was monitored. After 4 rounds (with a 100-fold increase in the titre of eluted phage), 24 out of 28 individual clones were found to be binding to TNF in an ELISA with phage expressing Fab fragments (all with the mouse VH-human CH1). Phage only displaying the selected human VλCλ domains gave a background similar to phage displaying only the chimaeric mouse Vk-human Ck. Sixteen clones taken after the first round of selection were found to be negative. Only three different BstNl fingerprints were found amongst the 24 binders, with one pattern-dominating (21/24). Light chains VλA2, VλC4 and VλD1 were found with frequencies of 21/24, 2/24 and 1/24 respectively. Sequencing revealed that all three light chains are derived from the same germline gene, a human Vλ1-1-1. Clone VλC4 has 1, clone VλD1 has 2 and clone VλA2 7 amino-acid residue differences from the germline. However, clone VλA2 uses a framework-1 region which more closely resembled the germline sequence ofa related Vλ1, humv1117, and therefore may be the result of a cross-over. The germline character of the clones was also noted in the CDR3 sequence, with minimal variation in sequence and no length variation between the three clones. Apparently, only a very limited number of genes with very similar sequences fix the stringent requirements (being compatible with the mouse VH and forming an antigen-binding pair). Selecting a Human VH Using the Selected Human VL Domains as Docking Chains Three selected Vλ genes were recloned in pUC19-pe1B-myc for soluble expression VλCλ chains. E.coli cells harbouring the three light chain plasmids were mixed, infected with a phage library of human VHCH1 genes, expressed from the fd-tet-DOC1 library described earlier and the library subjected to rounds of panning on TNF-coated Immuno tubes. Clones were picked after 5 rounds, when the titre of eluted phage increased 100-fold. Fifteen out of 20 clones analysed by BstNI fingerprint of the DNA insert used one of two patterns (with approximately the same frequency). The 15 clones when combining their heavy chain VHCH1 fragments with the VλA2 light chain gave stronger phase ELISA signals than when combined with the VλC4 or VλD1 light chain. Background signals obtained with phage displaying the heavy chain VHCH1 fragment only were similar to the signal of the murine VH-human CH1. Sequencing revealed that the two patterns could be assigned to three unique human VH sequences (clones VHP1/2/3, with clone VHP1 having a BstNI fingerprint which is nearly identical to that of clone VHP2). Like the selected light chain genes, the selected heavy chain genes are derived from the same germline VH gene (germline DP-51 from the VH3 family, Tomlinson et al., J. Mol. Biol. 227, pp776-798 1992), with minimal residue differences. The selected human V-genes were aligned to their closest germline homologue; identical residues in the selected genes are represented by hyphens. Framework 4 of the V H genes was truncated at 4th residue. Clone VHP1 was most likely a cross-over between DP-51 and a related germline, DP-47. All three selected VH-genes had relatively short CDR3 loops (8, 9 and 10 residues), but shared little homology in this sequence. Specificity of Binding of the Selected V-gene Pairs A specificity ELISA with MAb32 and soluble ScFv fragments on a number of antigens showed that MAb32, its ScFv-derivative and three of the humanised TNF-binders (as ScFv-fragments) bind specifically to TNF. No significant binding was obtained to ELISA plates coated with keyhole limpet haemocyanin, ovalbumin, cytochrome c. bovine serum albumin, human thyroglobulin, or 2-phenyloxazol-5-one-BSA or to plastic only. Fully humanized clones were obtained which bound to both peptide 301 and TNF. In addition, to show that the human scFv fragments compete with the original antibody for binding to TNF, the binding of the scFv constructs in a competition ELISA with the Fab fragment derived by proteolytic cleavage of MAb32 was analysed. Single chain Fv fragments were incubated on a TNF-coated surface with increasing amounts of the Fab fragment and the amount of bound scFv detected in ELISA. Each of the scFv fragments competed with the FabMAb32 for binding to TNF, including both the original scFv-MAb32 and the humanised scFv fragments. Thus the fine specificity of MAb32 for peptide 301 of TNF was retained through the humanisation process. Affinity of Binding of the Selected V Gene Pairs MAb32 and purified, monomeric forms of the recombinant mouse scFv-MAb32 and the human scFv antibodies VHP1-VλA2. VHP2-VλA2 and VHP3-VλA2, were subjected to competition ELISA for the determination of the relative affinity for TNF. Antibodies were incubated on a TNF-coated surface in the presence of increasing amounts of soluble TNF. All the clones showed a roughly similar decrease in the ELISA signal over the same range of increasing TNF concentrations (with an IC50 in the 10 nM to 100 nM range). MAb32 and VHP3VλA2 fragments were also analysed for binding properties using the Pharmacia BIAcore. TNF was indirectly immobilised on the surface, and the binding of antibody monitored. On the TNF surface, the Fab fragment from MAb32 by proteolytic cleavage and the scFv MAb32 showed very similar fast off rates (approximately 10 −2 s −1 ). The human VHP3-VλA2 antibody has an off rate in the same range as the original scFv-MAb32. On rates for antibody protein interactions were in the range seen for the interaction between other proteins and their receptors, and cover a 100 fold range between 10 4 and 10 6 M −1 S −1 (Mason D. W. and Williams, A. F., 1986, Kinetics of Antibody Reactions and the Analysis of Cell Surface Antigens, Blackwell, Oxford; Pecht, I., 1992 in Sela, M. (ed), Dynamic Aspects of Antibody Function, Academic Press Inc., New York, Vol. 6 pp 1-68). Assuming the on rates of the antibody TNF interactions are typical of antibody protein interactions, the off rate derived by the BIACore analysis is consistent with the affinity indicated by the competition ELISA (Kd≅10 −7 to 10 −8 M). Thus, these determinations are consistent with scFvMAb32 and the humanised scFv clone VHP3-VλA2 having a similar affinity and thus with the retention of affinity, as well as specificity, through epitope imprinted selection. Conclusion We have shown that a mouse antibody can be rebuilt into a human antibody with the same specificity by the process of epitope imprinted selection (EIS). A library of human light chains were shuffled with a mouse VH domain, binding combinations selected and then used in a second shuffle as “docking domains” for a library of human VH genes. Completely human antibodies were isolated from such “genuine” human library. The antibodies were shown to bind retain binding specificity. Alternatively, the mouse VL was used as docking chain for selecting human VH partners. Such VH domains can be used to find human VL genes, or alternatively, can be combined with human VL domains selected with the mouse VH domain. Indeed, binding activity was obtained by combining two independently selected V-genes, pointing towards potential additivity of the EIS procedure. The EIS approach may serve to humanise antibodies more rapidly than by CDR-grafting (Riechmann et al., 1988, supra), as this method requires very often a detailed knowledge of the 3-D structure of the antibody. However, the EIS method can be extended to for example antibody repertoires obtained by phage selection from immunised rodents. Following immunisation with antigen, a repertoire of V-genes with high affinity and specificity may be selected and then used in an epitope imprinted selection (see example 4) to generate a range of human antibodies of high affinity and enriched for the desired specificity. Enhancement of TNF-Induced Tumour Regression by Antibody VHP3-VλA2, the Human Equivalent of MAB 32 BALB/c mice wer e inoculated with WEHI-164 tumour cells as described above. After development of subcutaneous tumours the micewere treated daily with TNF (1 or 10 μg) alone or in combination with purified P3A2 (50μ) by intraperitoneal injection. Tumour size was measured throughout the course of the treatment period. Results are shown in FIG. 35 . VHP3-VλA2 enhanced the anti-tumour activity of TNF at both the 1 and 10 μg levels. Conclusions Mapping of the regions recognised by each of the MAbs has indicated that tAbs in group I (MAbs 1, 21, 47, 54, 37, 32 and 25 as show n on the schematic diagram bind TNF in theuregion of residues 1-18 with the exception of MAbs 37 and 54, while MAbs in group II of the schematic diagram (MAbs 11, 12, 53 and 42) bind TNF in the region of residues 70-96 which encompasses a so-called pallendromic loop on the TNF 3-D structure. MAbs which inhibit the induction of endothelial cell procoagulant activity (MAbs 1, 32, 42, 47, 54 and 53) all bind in the region of residues 108-128 which again contains a loop structure in the 3-D model and may indicate that this region interacts with TNF receptors which are found on endothelial cells but not tumour cells. MAb 32 which potentiates the in viva tumour regression andanti-viral activity of TNF is the only antibody which binds all the loop regions associated with residues 1-26, 117-128, and 141-153 and hence binding of these regions is crucial for enhanced TNF bioactivity with concommittant reduction of toxicity for normal cells. As is apparent from Table 2 MAb 1, 47 and 54 have the same effect on the bioactivity of TNF. From the results presented above it is noted that these three monoclonals bind to similar regions of the TNF molecule. Accordingly, it is believed that a ligand which binds to TNF in at least two regions selected from the group consisting predominately of the region of residues 1-20, the region of residues 56-77, the region of residues 108-128 and the region of residues 138-149 will effect the bioactivity of TNF in a manner similar to that of MAbs 1, 47 and 54. Similarly, it is believed that a ligand which binds to TNF predominately in the regions of residues 1-20 and 76-90 will have the same effect on the bioactivity of TNF as MAb 21. A ligand which binds to TNF predominately in the regions of residues 22-40 and 69-97 will have the same effect on bioactivity of TNF as MAb 12. A ligand which binds to TNF predominately in the regions of residues 1-30, 117-128, and 141-153 would be expected to have the same effect on the bioactivity of TNF as MAb 32 and a ligand which binds to TNF predominately in the regions of residues 22-40, 49-97, 110-127 and 136-153 would be expected to have the same effect on the bioactivity of TNF as MAb 42. A ligand which binds to TNF predominately in the regions of residues 22-31 and 146-157 would be expected to have the same effect on the bioactivity of TNF as MAb 37 and a ligand which binds to TNF predominately in the regions of residues 22-40, 69-97, 105-128 and 135-155 would be expected to have the same effect on the bioactivity of TNF as MAb 53. The present inventors have quite clearly shown that the bioactivity of TNF can be altered by the binding of a ligand to the TNF, and that the effect on the bioactivity is a function of the specificity of the ligand. For example, the binding of MAb 32 to TNF in the regions of residues 1-26, 117-128 and 141-153 results in the induction of endothelial procoagulant activity of the TNF and binding of TNF to receptors on endothelial cells being inhibited; the induction of tumour fibrin deposition and tumour regression activities of the TNF being enhanced; the cytotoxicity being unaffected and the tumour receptor binding activities of the TNF being unaffected or enhanced. It is believed that this effect on the bioactivity of the TNF may be due to the prevention of the binding of the epitope of the TNF recognised by MAb 32 to naturally occurring biologically active ligands. Accordingly, it is believed that a similar effect to that produced by MAb 32 could also be produced by a ligand which binds to a region of TNF in a manner such that the epitope recognised by MAb 32 is prevented from binding to naturally occurring biologically active ligands. This prevention of binding may be due to steric hindrance or other mechanisms. Accordingly, it is intended that the prevention of the binding of epitopes recognised by the various monoclonal antibodies described herein to naturally occurring biologically active ligands is within the scope of the present invention.

Provided are isolated antibodies or fragments thereof which bind a peptide consisting of residues Leu 63 -Phe 64 -Lys 65 -Gly 66 -Gln 67 -Gly 68 -Cys 69 -Pro 70 -Ser 71 -Thr 72 -His 73 -Val 74 -Leu 75 -Leu 76 -Thr 77 -His 78 -Thr 79 -Ile 80 -Ser 81 -Arg 82 -Ile 83 (peptide 304) of mature human TNF-α. The antibodies and fragments thereof may be used to identify antibodies capable of binding in the region of mature human TNF-α of amino acid resides 63-83. Antibodies or fragments thereof which bind particular regions of mature human TNF-α are shown to elicit particular biological activities dependent upon the particular region wherein binding occurs.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This is a Continuation-in-part application of U.S. Ser. No. 14/622,978 filed Feb. 16, 2015, which claims priority under 35 U.S.C. §119 to provisional application U.S. Ser. No. 62/065,850 filed Oct. 20, 2014, all of which are herein incorporated by reference in their entirety. FIELD OF THE INVENTION [0002] The present invention relates to technology for obtaining and retaining records of informed consent. BACKGROUND OF THE ART [0003] Although the present invention has uses in various areas, the background of the invention is discussed with respect to particular problems in the medical profession. The invention is not, however, necessarily limited to these particular medical applications. [0004] In medicine, informed consent is important. Generally informed consent involves health care providers providing complete information about the nature of a medical procedure or other event. This information can include information about possible complications, who is performing the procedure, and other relevant information which may vary depending on the circumstances. The patient needs to understand what is being conveyed and be competent to make a decision in view of the information provided by the health care provider. This process is consistent with medical ethics. [0005] Informed consent is generally obtained by having the patient sign a document indicating that they have provided their informed consent after they have had a discussion with their health care provider and/or reviewed appropriate written materials. This step is helpful for legal reasons as the patient contractually agrees that they have given their informed consent. Failure to obtain consent can result in claims of battery, negligence, or other legal claims against a health care provider regardless of whether medical procedures were performed competently. Despite written consent, problems remain. [0006] For example, patients may fail to recall conversations with the health care provider and informed consent documents may not always capture all information discussed between patients and health care providers or establish that patients had the opportunity to have all of their questions and concerns addressed. What is needed is a technological solution which improves the informed consent process. SUMMARY [0007] Therefore, it is a primary object, feature, or advantage of the present invention to improve over the art. [0008] It is a further object, feature, or advantage of the present invention to obtain informed consent from patients in a manner consistent with the highest order of medical ethics. [0009] It is a still further object, feature, or advantage of the present invention to improve the communications between health care provider and patient in situations where informed consent is needed. [0010] Another object, feature, or advantage of the present invention is to improve upon the documentation of informed consent. [0011] Yet another object, feature, or advantage of the present invention is to eliminate or defend against frivolous claims for failure to obtain informed consent. [0012] Another object, feature, or advantage is to provide a method of obtaining informed consent which can be used in different industries. [0013] Yet another object, feature, or advantage is to provide a software application with the ornamental design as shown. [0014] A further object, feature, or advantage is to provide the ability for health care providers to choose videos from a library of videos for use in providing their patients with informed consent. [0015] A further object, feature, or advantage is to provide the ability for patients and health care providers to be in separated locations, including remote from one another, and obtain informed consent from patients. [0016] A further object, feature, or advantage is to provide an integrated system for informed consent or analogous consent including health care related events as well as others. [0017] A further object, feature, or advantage is to provide verification of understanding of instructional and educational content used in the informed consent process with high level of competence and documenting the same. [0018] A further object, feature, or advantage is to provide informed consent, techniques across the range of times, events, or milestones in a process in need of informed consent. In one example, it could be at a pre-event time (in a medical context pre-operation counseling session), it could be prior to an event (in the medical context prior to surgery or a medical procedure), and/or at a subsequent event (in a medical context, a post-operative counseling event). Ancillary features such as communication via text messages and emails, providing links to a web based set of content, and use of other automatic documenting, milestone data (e.g., time stamps, GPS location), are possible in an integrated system. [0019] One or more of these and/or other objects, features, or advantages of the present invention will become apparent from the specification and claims that follow. No single embodiment need exhibit each and every object, feature, or advantage and different embodiments may have different objects, features, or advantages. [0020] According to one aspect, a method for documenting informed consent is provided. The method includes obtaining a video recording of a patient indicative of informed consent, communicating the video recording across a network for data storage, and storing the video recording in a computer readable data storage medium. The method may further include positioning at least one video camera in a room associated with a health care provider in which the patient provides the informed consent. The method may further include retrieving the video recording of the patient indicative of informed consent over the network and from the computer readable storage medium. The method may further include providing a user interface to the health care provider for accessing the video recording. The method may further include combining data from a health care information system with the video recording. The video recording may further include at least a portion of a patient encounter. The method may further include making the video recording available to the patient through a portal. The method may further include making the video available to the patient by placing the video on a USB drive. [0021] According to another aspect, a method for obtaining and documenting informed consent is provided. The method includes providing a software application to a computing device for executing on the computing device, receiving a selection of an individual into the software application executing on the computing device. The method may further include receiving a selection of a procedure for which informed consent is desired into the software application executing on the computing device. The method may further include displaying an educational video to the individual using the software application executing on the computing device, the educational video containing educational content about the procedure for which the informed consent is desired. The method may further include the patient and health care provider and/or agent of the health care provider (being in different and even remote locations, each having a computing device with application and video capture device, for example a web cam), and communicating, recording, and storing activities related to obtaining patient informed consent. The video telephony, including but not limited to using peer-to-peer, N2N encrypted, video chat technology. The method may further include capturing video evidencing informed consent for the procedure using the software application executing on the computing device and making available a quiz for the individual using the software application executing on the computing device, the quiz including a plurality of questions about the procedure for assessing informed consent. The method may further include documenting administration of the quiz to the individual using the software application executing on the computing device, presenting a document for signature to the individual using the software application executing on the computing device, the documenting indicative of informed consent for the procedure. The method may further include receiving a signature on the document from the individual using the software application executing on the computing device, and sending to a server from the computing device the video, the document with the signature, and storing the video in a non-transitory computer readable data storage medium associated with the server to thereby provide for documenting the informed consent of the individual for the procedure. [0022] The capturing of video may be performed using a camera integrated into the computing device. The method may further include receiving a selection of an option to bypass the quiz and documenting a reason for bypassing the quiz by sending the reason to the server. The procedure may be a medical procedure and the individual may be a patient. The video may include video of the patient acknowledging that they are providing informed consent. The method may further include making the video available to the individual through a portal associated with the server. The method also may further include making the video available to a service provider of the individual through a portal associated with the server. The video may include video of the individual and a service provider interacting with the individual. The method may further include receiving through the software application setting information identifying a plurality of procedures and one or more procedure types. The method may further include receiving through the software application the document associated with the procedure. The method may further include receiving through the software application the plurality of questions about the procedure. The software application may be a mobile app and the computing device may be a mobile computing device. [0023] According to another aspect, a method for obtaining and documenting informed consent for a procedure from an individual is provided. The method includes providing a software application to a computing device for executing on the computing device wherein the software application provides a user interface for obtaining video evidencing informed consent for the procedure, administering a quiz to the individual, presenting a document for signature to the individual, receiving a signature for the document from the individual. The method further includes receiving a selection of a procedure for which informed consent is desired into the software application executing on the computing device. The method may further include displaying an educational video to the individual using the software application executing on the computing device, the educational video containing educational content about the procedure for which the informed consent is desired. The method may further include capturing the video evidencing informed consent for the procedure using the software application executing on the computing device, and presenting the document for signature to the individual using the software application executing on the computing device, the documenting indicative of informed consent for the procedure. The method may further include receiving the signature on the document from the individual using the software application executing on the computing device and sending to a server from the computing device the video, the document with the signature, and storing the video in a non-transitory computer readable data storage medium associated with the server to thereby provide for documenting the informed consent of the individual for the procedure. The method may further include administering the quiz for the individual using the software application executing on the computing device, the quiz including a plurality of questions about the procedure for assessing informed consent. The method may further include documenting administration of the quiz to the individual using the software application executing on the computing device and sending a record of the administration of the quiz to the server from the computing device. [0024] According to another aspect, a system is provided for obtaining and documenting informed consent. The system may include a software application for executing on a computing device wherein the software application provides a user interface for obtaining video evidencing informed consent for the procedure, administering a quiz to the individual, presenting a document for signature to the individual, receiving a signature for the document from the individual. BRIEF DESCRIPTION OF THE DRAWINGS [0025] FIG. 1A is a diagram illustrating one example of a system for obtaining informed consent using video. [0026] FIG. 1B is another diagram illustrating another example of a system for obtaining informed consent using video. [0027] FIG. 1C is another diagram illustrating another example of this system through obtaining informed consent using video telephony. [0028] FIG. 2 is a diagram of a screen display of a user interface for a patient to review informed consent documentation. [0029] FIG. 3 is a screen display of a user interface for a health care provider to review informed consent videos. [0030] FIG. 4 is a screen display of a user interface for a patient to review informed consent videos. [0031] FIG. 5 is a screen display from a mobile app for obtaining informed consent. [0032] FIG. 6 is a screen display for a mobile app allowing a user to select a patient, add a patient, or select a procedure. [0033] FIG. 7 is a screen display for a mobile app for obtaining informed consent where a user is permitted to select a patient. [0034] FIG. 8 is a screen display for a mobile app for obtaining informed consent where a user is permitted to select a procedure. [0035] FIG. 9 is another screen display for a mobile app for obtaining informed consent where a user is permitted to select a procedure. [0036] FIG. 10 is a screen display for a mobile app which includes a consultation menu. [0037] FIG. 11 is a screen display for a mobile app which displays video of a patient. [0038] FIG. 12 is another screen display for a mobile app which displays video of a patient. [0039] FIG. 13 is a screen display for a mobile app which presents a quiz. [0040] FIG. 14 is a screen display for a mobile app after a patient has selected an answer to a question of a quiz. [0041] FIG. 15 is a screen display for a mobile app showing another example of a quiz question and an answer has been selected by a patient. [0042] FIG. 16 is a screen display for a mobile app showing yet another example of a quiz question and an answer which has been selected by a patient. [0043] FIG. 17 is a screen display for a mobile app showing an example of a true/false question and answer to a quiz question. [0044] FIG. 18 is a screen display for a mobile app showing an example of a quiz question, a user's answer to the quiz question and a correct answer to the question. [0045] FIG. 19 is a screen display for a mobile app showing an example of quiz results. [0046] FIG. 20 is a screen display showing a mobile app with a consultation app where a user has selected to bypass the quiz. [0047] FIG. 21 is a screen display showing a mobile app with a consent for surgery or procedure document. [0048] FIG. 22 is a screen display showing a mobile app which allows a patient to sign a consent document. [0049] FIG. 23 is a screen display showing a mobile app with a signed consent document. [0050] FIG. 24 is a screen display for a mobile app showing a patient, a procedure, and indicating that video has been captured, a quiz has been completed, and a signature has been provided. [0051] FIG. 25 is a screen display for a mobile app showing a manage procedure screen. [0052] FIG. 26 is a screen display for a mobile app showing a settings screen. [0053] FIG. 27 is a screen display for a mobile app showing a settings screen where a profile is selected. [0054] FIG. 28 is another example of a screen display for a mobile app showing a settings screen. [0055] FIG. 29 is a screen display to manage procedures. [0056] FIG. 30 is a schematic diagram of an integrated system such as could be used for informed consent at different times and for different events in a patient, health care provider context. [0057] FIG. 31 is a block diagram of one example of a flow process in the context of a patient/health care provider informed consent process. [0058] FIG. 32 is one example of a verification technique for confirming understanding of content to a high level of competence such as could be used with the present system. DETAILED DESCRIPTION [0059] The present invention provides for a comprehensive system and related methods for obtaining informed consent including video records of informed consent. Primarily, the invention will be described with respect to a software application suitable for use on a mobile computing device which may be referred to as a “mobile app.” It is to be understood, however, that the software application described may execute on any number of different types of computing devices including desktop computers, notebook computers, tablets, wearable computers, phones, or other types of computing devices. The computing device may use any number of different types of operating systems including iOS, Android, Blackberry, Windows, or other operating systems. The software may be written in any number of different types of languages using any number of different types of platforms or tools. As shown herein the mobile app is executing on an Apple iPAD with an iOS operating system which provides a touch screen interface. The Apple iPAD also includes multiple video cameras. [0060] FIG. 1A illustrates a system 10 . A patient 12 and health care provider 14 are shown. A video device 16 is shown which may be used to acquire audio and video of the patient 12 and/or interactions between the patient 12 and the health care provider 14 . The video device 12 may include one or more cameras or other imaging devices located in a patient examination room, office, or other location in a physician's office or other health care facility. [0061] One or more video devices 16 may be operatively connected to a gateway 18 . The gateway 18 may be operatively connected to the internet 20 . The internet may be operatively connected to or include a distributed server network 22 . The distributed server network 22 may be operatively connected to data storage 24 . [0062] In addition, it is also contemplated that one or more health care information systems 25 associated with the practice of the health care provider may also be operatively connected to the gateway 18 . It is contemplated that information from the health care information system 25 may be combined with the video either automatically or manually to identify the video such as with a unique patient identifier, type of procedure for which informed consent is given, or other information. In addition, stored videos may be made available to the health care information system 25 . [0063] In operation, a health care provider 14 may discuss with a patient 12 an upcoming medical procedure, the attendant risks, who will be performing the procedure, possible complications, and other relevant information. The patient 12 may ask questions that they have about the procedure, confirm that they have read appropriate literature and verify that they are giving consent. The patient may then sign a written document confirming that they have provided informed consent or electronically sign a document confirming that they are providing informed consent. During this, or any other interaction, the video device 16 may record relevant audio and video. Thus, a record of all or a part of the interaction may be recorded. For example, the portion of the interaction where the client signs the informed consent may be recorded. The patient may be asked to read a statement confirming their consent on the video. The video may then be communicated through the gateway 18 and the internet 20 , over a distributed server network 22 and to data storage 24 . The video may then be made available to a computing device 26 for playback by the health care provider 14 . In some embodiments, the video may also be made available to the patient 12 . The video may be made available to the patient 12 through a web site portal, mobile app, or other portal 28 . Alternatively, the video may be available to the patient by storing the video for the patient on a computer readable storage medium such as a USB drive. The communication and storage of the video are performed securely in a manner consistent with all applicable health privacy laws and regulations. [0064] As described, the method and system provides for a number of different advantages. First, there is a more complete record of the informed consent. Patients are more apt to remember the interaction leading up to the informed consent when acknowledgement of the informed consent is made for video archive purposes. Patients are also more likely to appreciate the importance of the informed consent when (in their view) the process involves more than merely a form to sign but a video recorded confirmation of their consent. In addition, the video would provide additional evidence in legal proceedings which would be highly relevant to the legal determination of whether informed consent was provided or not. [0065] In situations where all or a portion of the interaction between the health care provider and patient is recorded an additional record of the complete interaction between health care provider and patient is made. Another potential benefit is that this may potentially be shared with the patient for their records in case they want to review information conveyed to them before their procedure. This information may be shared through a web site portal, through a mobile app, or may be stored on a computer readable storage medium such as a USB drive. [0066] Where all or a portion of the interaction between the health care provider and the patient is recorded this may also be advantageous in showing the patient that the health care provider is being very transparent in their communications and that informed consent is being provided in an appropriate manner. [0067] As previously discussed, in one embodiment the video camera may be mounted or otherwise positioned in a patient examination room or other room. Alternatively, a video camera associated with a mobile device or other computing device such as a tablet computer may be used to record the informed consent. Where used, the video may be wirelessly communicated to the gateway 18 shown in FIG. 1A . [0068] Where a mobile device is used, any documents pertaining to informed consent may be signed in addition to video being recorded. FIG. 1B illustrates an embodiment with a computing device 26 which includes a non-transitory computer readable memory for storing an app 27 . One or more cameras or other imaging devices 16 may be a part of the computing device 26 . The computing device 26 may, for example, be a mobile device such as a tablet computer. [0069] Although a health care provider 14 and a patient 12 are shown it is to be understood that the health care provider is one example of a service provider and the patient may be a customer or client. In addition, the health care information system 25 may be another type of information system associated with a different type of business. [0070] FIG. 1C illustrates another example of a system that can use at least some aspects of the present invention. Patient 12 and health care provider 14 (or a representative of the same) can be in separate or geographically remote locations. Each would have a computing device (for patient 12 computing device 26 ; for health care provider 14 computing device 26 ′). Utilizing video telephony, patient 12 and health care provider personnel 14 can communicate via both sight and sound (video and audio). In one example, a Skype® Brand application can be installed on each computing device 26 and 26 prime. Such applications are available for any computing device that is internet-enabled, including mobile devices and smart phones. Such applications can include security features such as user authentication and N2N encryption. Instead of the health care provider 14 and the patient 12 being in the same room and being able to have face to face view and communication, this would allow remote video and audio teleconferencing type communication. By appropriate technology, at least a portion of any captured video and audio from video device 16 or 16 ′ can be captured and stored to document events involved in obtaining informed consent from patient 12 . For examples of utilizing video telephony, such as Skype®, reference can be taken to U.S. Pat. No. 8,533,611 and published in U.S. Publication 2013/0117395, both incorporated by reference herein. Essentially it is the same process as in the doctor's or health care provider's office, as discussed elsewhere herein, but the doctor communicates to the patient through video conference. The system allows recording, encrypting, compressing, and/or storing on a server at least a part of the video conference. The application enabling the same can be to a stand-alone website, or using an existing telemedicine interface. [0071] Additional applications may have to be used to allow recording of the teleconference. For example, Skype® does not natively support call recording. However, its website lists applications that can be used in both Windows and Mac devices that allow recording of Skype® calls. Examples are listed at http://support.skype.com/ EN/fax/FA12395/how-can-I-record-my-skype-calls. Software of the computing device can then capture link, and transmit any of the recorded teleconference in correlation to the informed consent process to a remote server. See for example U.S. Pat. No. 8,909,811 and US 2013/0019149 for examples of recording such things as peer-to-peer telephony recording, both incorporated by reference herein. [0072] FIG. 2 illustrates an example of a mobile device 16 with a display 30 and a camera 32 . In one embodiment, the patient may be asked to read a statement re-affirming their informed consent while on camera. [0073] Once the informed consent videos are stored they may be accessed as needed. FIG. 3 is an example of a screen display 40 illustrating that for each patient there may be one or more examples of informed consent they have given on different occasions and corresponding video is also made available. Thus as shown, for a first patient there are multiple procedures and videos 42 listed and also for a second patient there are multiple procedures and videos 44 listed. Thus, the health care provider has a record of the informed consent. [0074] FIG. 4 illustrates one example of a portal 46 where a patient may view examples of informed consent 48 which they have previously given. Thus, after a visit with a health care provider, a patient can go back and review informed consent videos if they would like. Alternatively, the informed consent video may be stored on a computer readable storage media such as USB drives and given to the patient at the time of the visit. [0075] FIG. 5 is a screen display 50 from a mobile app for obtaining informed consent. As shown on a “Main Menu”, there is a “Start” button 52 , a “Procedures” button 54 , and a “Settings” button 56 . The mobile app may be operated by a health care provider in order to obtain informed consent from patients. [0076] FIG. 6 is a screen display 60 for a mobile app allowing a user to select a patient using a “Select Patient” button 66 , add a patient using an “Add Patient” button, or select a procedure using a “Select Procedure” button. The screen is identified as a “Patient and Procedure Selection” screen 64 . A user can navigate back to the “Main Menu” 62 . Once appropriate patient and procedure selections have been made a user can advance by selecting the “Next” button 72 . The “Next” button 72 may be disabled unless and until the patient and procedure selections have been made. [0077] FIG. 7 is a screen display 74 for a mobile app for obtaining informed consent where a user is permitted to select a patient. A “Select Patient” window 76 is shown which allows a user to select a patient from a list of patients 78 and confirm this selection by using the “Select” button 80 . [0078] FIG. 8 is a screen display 82 for a mobile app for obtaining informed consent where a user is permitted to select a procedure. Note that the user has already selected a patient. A “Select Procedure” window 84 is shown which allows a user to select a procedure from a list of procedures 86 and confirm this selection by using the “Select” button 88 . [0079] FIG. 9 is another screen display 90 for a mobile app for obtaining informed consent where a user is permitted to select a procedure. FIG. 9 is similar to FIG. 8 , however a different procedure within the list of procedures 92 is selected, in this case a Radical Retropubic Prostatectomy with Pelvic Lymph Node Dissection. [0080] FIG. 10 is a screen display 100 for a mobile app which includes a consultation menu 102 . The user may select to return to the Procedure Selection 104 . As shown in FIG. 10 , there are buttons for “Capture Video” 106 , “Quiz” 108 , “Sign”, 110 , and “Bypass Quiz” 112 . There is also a “Save” button 114 . [0081] FIG. 11 is a screen display 120 for a mobile app which displays video of a health care provider 128 . A timer 126 may be present as well as a record/stop button 122 and an option to “Cancel” 124 . Thus, video of the health care provider may be recorded to assist in documenting the informed consent of the patient. [0082] FIG. 12 is another screen display 130 for a mobile app which displays a video. The screen display 130 may be displayed after video has been recorded. User options are shown along the bottom of the screen display 130 . The user may select “Retake” to retake the video if they are unsatisfied for any reason. A “play” button 137 is shown to play the video. If the user is content with the video then they may select to “Use Video” 138 . [0083] It is also contemplated that the mobile app may allow a video to be selected from a library of videos. The videos may be videos of the health care provider, colleagues of the health care provider, or others. Thus, for example, instead of the health care provider recording a video each time, the health care provider can select to display to the patient a pre-recorded video. It is contemplated that when a video is pre-recorded and will be used more than once that even greater thought can go into the presentation of the information to present information in the easiest to follow manner and a higher production quality may go into the video. It is also contemplated that particular videos may become accepted within the medical community as appropriate in particular instances. Alternatively, different videos may become accepted within particular hospital systems or physician groups as best practices. Similarly different videos may be endorsed by particular insurance companies, medical organizations, or others. It is contemplated that the videos may be included within the app, may be provided by the health care provider, or may be purchased through an in-app purchase or otherwise. [0084] FIG. 13 is a screen display 140 for a mobile app which presents a quiz. A menu bar 142 is provided that allows the “Consultation Menu” to be selected to return the user to a previous screen. The quiz includes a question 146 . Multiple choice answers 148 are also shown. One example of a representative question is “What operation did Dr. Fialkov discuss with you today?” The answers include various examples of operations one of which was actually discussed. The user is also given the option of selecting a “Play Video” button 150 . A “Next” button is also shown. The “Next” button may be disabled unless and until an answer is selected. [0085] FIG. 14 is a screen display 154 for a mobile app after a patient has selected an answer to a question of a quiz, in this instance “Radical Prostatectomy with Lymph Node Dissection (removal of prostate and lymph nodes for prostate cancer)” 156 . Here, the patient has selected the correct answer to the question. [0086] FIG. 15 is a screen display 160 for a mobile app showing another example of a quiz question and an answer has been selected by a patient. Here the question 162 is “What is NOT a potential problem that can arise from this operation?” Various answers 164 are provided. Here a patient has selected “Weight gain” 166 which is also a correct answer. [0087] FIG. 16 is a screen display 170 for a mobile app showing yet another example of a quiz question and an answer which has been selected by a patient. Here, the question 172 is “What is the approximate cancer cure rate for this operation given your pathology report from the recent biopsy Dr. Fialkov performed?” Various answers 174 are shown. A patient may select an incorrect answer 176 after which a correct answer 178 may be highlighted or emphasized in a different color. Thus, if the patient responds incorrectly, the patient is immediately informed of the correct answer. If the patient desires they can review the video again by selecting the “Play Video” button 150 . Note that the patient may select the “Play Video” button before or after they answer. [0088] FIG. 17 is a screen display 180 for a mobile app showing an example of a true/false question 182 and answers 184 to the quiz question 182 . Here, the correct answer “True” 186 is selected by the patient. [0089] FIG. 18 is a screen display 140 for a mobile app showing an example of a quiz question 192 and multiple choice answers 194 . A user's answer 196 to the quiz question 192 is shown as well as the correct or best answer 198 . Instead of a next button, a “Summary” button 152 is shown upon completion of the quiz. [0090] FIG. 19 is a screen display 208 for a mobile app showing an example of quiz results 202 . A user can return to the quiz by selecting “Quiz” 204 . Each of the questions are shown again as well as the correct answer if the correct answer was selected by the patient. Where the patient did not select the correct answer the patient's selection is also shown. Thus, the patient is able to review all of the quiz questions and answers. [0091] FIG. 20 is a screen display 210 showing a mobile app with a consultation app where a user has selected to bypass the quiz. A quiz bypass area 224 is shown which allows a user to select a reason why the quiz is being bypassed. There may be various reasons why it may not be necessary or appropriate to implement the quiz such as the patient being unable to answer questions due to a temporary or permanent incapacity 228 or because consent will be obtained from another individual with power of attorney 230 , it is an emergency situation, or other reason. Once the reason to bypass the quiz has been given the user may choose the “Select” button 232 . [0092] FIG. 21 is a screen display 240 showing a mobile app with a consent for surgery or procedure document 242 . At the top of the screen display a user may select the Consultation Menu 246 to return to the previous screen or choose “Save” 244 to save the document after it has been signed. [0093] FIG. 22 is a screen display 250 showing a mobile app which allows a patient to sign a consent document. A signature area 252 is shown allowing a patient or other authorized individual to sign above the signature line 256 . An option for saving the signature 258 is presented as well as an option to “Save Appearance”. An option to “Cancel” 262 is also provided. Thus, after a patient has been informed about a procedure they can sign to indicate their consent. [0094] FIG. 23 illustrates the screen display 250 of FIG. 22 showing a mobile app with a signed consent document after a patient has provided their signature 256 . [0095] FIG. 24 illustrates the screen display 200 for a mobile app showing a patient and a consultation menu 212 . As shown in FIG. 24 , there are checkmarks to indicate that different steps have been performed. In particular, it is clear that video has been captured, the quiz has been completed, and a signature has been provided. The “Save” button 270 can be selected to save the information associated with the procedure. [0096] FIG. 25 is a screen display 300 for a mobile app showing a manage procedure screen. This allows a health care provider using the mobile app to setup different types of procedures by selecting to “Edit” 306 procedure types and “Edit” 308 different procedure types. There is a “Manage Quiz” button 310 and a “Manage PDF” button 312 . A “Done” button 314 is also shown. [0097] FIG. 26 is a screen display 320 for a mobile app showing a settings 322 screen. A user may select “Main Menu” 324 to return to the main menu if the user chooses to do so. [0098] The user is allowed to enter a profile name 326 and a client type 328 . The user can select to “Add Profile” 330 or “Select Profile” 332 . [0099] FIG. 27 is a screen display 340 for a mobile app showing a settings screen where a profile is selected. Here an area 342 is shown with a set of profiles 344 from which the user can select. Thus, the app can be configured for different uses such as financial, medical, legal, etc. There are numerous examples of situations where informed consent is important and/or where one party has a duty or obligation to obtain informed consent from another party. [0100] FIG. 28 is another example of a screen display 350 for a mobile app showing a settings screen. Note that in FIG. 28 the profile name shown is “Financial” 352 . [0101] FIG. 29 is a screen display 360 for managing procedures. Here the type of procedure is “Finance” and the procedure is “Annuity.” Thus, there are many possible uses for the informed consent applications which may be used in financial, legal, medical, or other situations. [0102] It should be understood that a number of features may be incorporated into the mobile app to ensure privacy and security. For example, it is contemplated that a patient using a computing device with the app to take the quiz, for example, would not be able to see the screen which would allow them to see the names of other patients. This can be accomplished by requiring the health care provider's password to view such a screen or otherwise locking the patient out from those portions of the app which they are not permitted to view. [0103] It should also be understood that video is preferably not stored on the computing device at all or if so, only temporarily. Instead, video is streamed to a server for storage or alternatively video may be temporarily saved on the computing device for purposes of uploading to the server and then deleted or wiped from the computing device so that no version of the video remains on the computing device. Other patient data may be similarly treated including consent documents and quiz results. [0104] Although discussed primarily with respect to informed consent, it is noted that the use of the video cameras in the examination rooms can be used for other purposes related to documenting patient encounters. For example, health care providers are often subjected to false accusations. Accusations of any sort are taken very seriously and investigated thoroughly which can be time consuming for investigators as well as the health care provider involved. Moreover, even unsubstantiated allegations and the mere fact that an investigation took place can have a negative effect on the careers of health care providers. Such accusations can include accusations of sexual assault. One way such accusations can be guarded against is to have a female nurse or other staff member present during a male physician's examination of a female patient. However, this unnecessarily uses resources. Having a video camera present makes a record of the encounter which could be used not only to address false accusations of assault or other wrongdoing but to conclusively prove it unfounded and to use as evidence against the false accuser in criminal or civil litigation. Mere knowledge of the use of the video cameras may provide a significant deterrent to false accusations. [0105] This documentation could be used for other purposes including addressing insurance disputes regarding whether procedures occurred and/or the level of care provided (e.g. the diagnosis codes used to support a particular intervention). Thus, it is to be understood that the video system described may be used for purposes other than informed consent. [0106] Although various methods and systems have been described herein, it is to be understood that the present invention is not to be limited to the specific embodiments described. Moreover, the present invention contemplates numerous variations, additions, modifications, options, and alternatives. [0107] A few examples of options and alternatives for the aspects of an informed consent system such as above described will follow. [0108] With reference to FIG. 30 , the ability to have an integrated, wide-ranging system is illustrated. Both direct patient/health care provider interactions and/or remote patient/health care provider interactions are possible, including utilization of the techniques and aspects described above. This can include automatically providing content to assist in the “informed” side of “informed consent”. Examples are through informational videos or other content. Further examples are the presentation of quizzes or testing for understanding of that content. [0109] FIG. 30 also shows how documentation can occur, an important aspect to many informed consent scenarios. [0110] FIG. 30 also illustrates how an overall system could be implemented. Use of servers or computers in different capacities and locations, as well as web application, mobile applications and the like are shown. [0111] FIG. 31 shows one example of a process flow for a patient/health care provider informed consent implementation. The flow process includes the initial entering of information regarding the visit. There can be a match of existing or entered information relative a care plan established for the patient. The flow chart includes the presentation (in some form) to the patient of in this example an informational video regarding proposed procedure or treatment. In this example, a recording (audio, video, audio and video, as examples) can be taken of the health care provider/patient conversation after the informational video. The patient then takes a quiz until verification of a passing level. The patient reviews and signs a consent form. That captured and stored form consent is then made available to relevant parties via access to the patient portal. This can be the patient, the health care provider, or another authorized person. [0112] As can be appreciated by those skilled in the art, the platform in which the invention and its aspects can be delivered can vary according to need or desire. Below is one example for a web application version. C no. ASP.NET web API with Azure SQL backend and data storage; encrypted Azure datastore for the video consultations and pdfs (or similar) for transmitting documents and content; Angular JS and Bootstrap UI for a website interface; and Microsoft Azure for the hosting (a HIPAA compliant platform). As can be appreciated, variations obvious to those skilled in the art are possible. [0113] A further optional feature would be to add additional techniques for gaining a high level of confidence of understanding by the patient or other person from which informed consent is sought of the educational content provided before requesting consent. One example is as follows. A PEMAT-A/V (Patient Education Materials Assessment Tool for Audio Visual materials) is an example of a scoring system that gives a high level of competence of understandability and actionability for content (such as the educational videos) contemplated with the present embodiments. FIG. 32 is an example of such a technique. The PEMAT-A/V assessment tool is defined as a systematic method to evaluate and compare the understandability and actionability of patient education materials. See http://www.ahrq.gov/professionals/prevention-chronic-care/improve/self-mgmt/pemat/pemat1.html (accessed online Aug. 19, 2015) which is incorporated by reference herein. Understandability is defined as patient education materials “when consumers of diverse backgrounds in varying levels of health literacy can process and explain key messages”; actionability is defined “when consumers of diverse backgrounds and varying levels of health literacy can identify what they can do based on the information presented.” Each of the educational videos contemplated in some of the embodiments could be reviewed by such a procedure for higher level of competence of understandability and actionability. Of course, other techniques are possible. FIG. 32 gives an idea of some of the techniques used in PEMAT-A/V for the indicated medical procedure in FIG. 32 . [0114] As will be appreciated in the art, an integrated system can have a variety of ancillary features. Below are examples. [0115] The informed consent methodologies described above can be applied at various time points, milestones, or events in a context using informed consent. For example, some of the above examples relate to pre-operation counseling. Using the same infrastructure, including the stored video collection and patient registration through the web portal, the system could send text messages and emails to patients with links to post-operative education videos and pdf documents. The current development in health care is the use of patient satisfaction surveys by groups such as Press Ganey. Links could be added to the web-based patient satisfaction survey in the same text or email, or at a later date. A comprehensive system for educating patients, obtaining informed consent preoperatively, documenting the informed consent using time stamps, video and the GPS capability of a digital device (e.g., iPad) and providing post-op care instructions and patient satisfaction feedback are possible from the single platform. [0116] As can be further appreciated by those skilled in the art, the informed consent can be applied in contexts beyond medical operations treatments. Some examples are with OSHA (Occupational Safety and Health Administration)-related contexts. For example, some safety workers need to be documented as understanding certain content. In an analogous way, embodiments could be configured to take worker information, present educational content regarding topic related to safety or an OSHA regulation, get high level confidence of understanding and actionability, and then get a signed form documenting the same. [0117] In another example, workers in jobs with known risks could be required to give informed consent. Documenting the same with these techniques could then be put in the worker's file or the company's file. They would then be available for access if, for example, a workman's compensation claim was filed.

A method for documenting informed consent includes obtaining a video recording of a patient indicative of informed consent, communicating the video recording across a network for data storage, and storing the video recording in a computer readable data storage medium. The video may include additional portions of a patient encounter. A software application for executing on a computing device may provide a user interface for displaying an educational video to the individual using the software application executing on the computing device, the educational video containing educational content about the procedure for which the informed consent is desired, obtaining video evidencing informed consent for the procedure, administering a quiz to the individual, presenting a document for signature to the individual, receiving a signature for the document from the individual.

BACKGROUND OF THE INVENTION This invention relates generally to an arithmetic logic unit (ALU), and more particularly, to an arithmetic logic unit utilizing strobed gates. Arithmetic logic units for performing both arithmetic and logical functions are well known. Such devices, however, are usually comprised of complex random logic which presents, in the case of an integrated circuit, certain layout difficulties which in turn results in the occupation of a significant amount of silicon area. Therefore, a need exists for an ALU which occupies less area without sacrificing functionality or versatility. SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved arithmetic logic unit. It is a further object of the present invention to provide an integrable arithmetic logic unit which utilizes strobed gates in order to reduce complexity and minimize silicon area. According to a broad aspect of the invention there is provided an arithmetic logic unit capable of performing AND, OR, exclusive-OR, and add functions, comprising an input portion for receiving a plurality of inputs each capable of assuming first and second states and for generating first and second outputs, the first output indicating that at least one of the plurality of inputs is in the first state, and the second output indicating that all of the inputs are in the first state. A first portion includes a first input coupled to the first output and has additional inputs coupled to receive a plurality of control signals and is responsive to the states thereof, for generating a third output when at least one of the plurality of inputs is in the first state. A second portion has a first input coupled to the second output and is responsive to the states of the control signals for generating a fourth output when all of the inputs are in the first state. A third portion has first and second inputs coupled to the first and second outputs respectively and is responsive to the control signals for generating a fifth output when only one of the plurality of inputs is in the first state. A fourth portion is provided for receiving a carry-in signal and the second, third, fourth, and fifth output signals for generating a carry-out signal. The ALU includes an output portion for receiving the third, fourth, and fifth output signals and the carry-in signal for generating an output corresponding to one of the functions. BRIEF DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawing which is a schematic diagram of the inventive arithmetic logic unit. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing which is a schematic diagram of the inventive arithmetic logic unit, all inputs and outputs are considered to be capable of assuming logical high voltage ("1") and logical low voltage ("0") states. Furthermore, the clock signal (CL) applied to the circuit for controlling the timing thereof is of the type wherein each cycle includes a high portion and a low portion. The signals to be operated on by the ALU are designated as A and B. These signals are applied to the input portion of the ALU which consists of N-channel field effect transistors 30, 32, 34, 36, 38, 40, and 42. Input signal A is applied to the gate electrodes of field effect transistors 30 and 32, and input signal B is applied to the gate electrodes of field-effect-transistors 34 and 40. A control signal ALB is applied to the gate electrodes of transistors 36 and 42. This control signal serves a special function and, when low makes the B input "0". For the time being, it is assumed that ALB is maintained at a high logic level. The source of transistor 30 is coupled to ground, and its drain is coupled to node 10. The source of transistor 32 is coupled to ground, and its drain is coupled to the source of transistor 34. The drain of transistor 34 is coupled to the source of transistor 36, the drain of which is coupled to node 16. A clock signal (CL) is coupled to the gate electrode of transistor 38 which has a source coupled to ground. The drain of transistor 38 is coupled to the source of transistor 40. The drain of transistor 40 is coupled to the source of transistor 42 which has a drain coupled to node 10. The input section above described is coupled to three series strings of field-effect-transistors which, under the control of control signals S1, S1, S2 and S2 select the function which the ALU is to perform. The first string includes N-channel field-effect-transistors 44 and 46 which have their gate electrodes coupled respectively to S1 and S2. The source of transistor 44 is coupled to node 16, and its drain is coupled to the source of transistor 46. The drain of transistor 46 is coupled to node 12. The second string consists of N-channel field-effect-transistors 52, 54 and 56. The gate electrode of transistor 52 is coupled to node 16, and the gate electrodes of transistors 54 and 56 are coupled respectively to S1 and S2. The source of transistor 52 is coupled to node 10, and its drain is coupled to the source of transistor 54. The drain of transistor 54 is coupled to the source of transistor 56 which has a drain coupled to node 12. The third string consists of N-channel field effect transistors 48 and 50 which have gate electrodes coupled respectively to S1 and S2. The source of transistor 48 is coupled to node 10, and its drain is coupled to the source of transistor 50. The drain of transistor 50 is coupled to node 12. It should thus be apparent that each of the first, second and third strings of transistors feed node 12. The ALU includes a carry-out portion which consists of P-channel field-effect-transistors 79, 81, 89 and 91, N-channel field-effect-transistors 84, 86, 88, and 90, and inverters 80, 82 and 92. The drains of P-channel field-effect-transistors 79 and 81 along with the gate electrode of transistor 84 and the input of inverter 80 are coupled to node 16. The gate of transistor 81 is coupled to receive the clock signal (CL), and the gate of transistor 79 is coupled to the output of inverter 80 and to the gate of transistor 86. The source of transistor 86 is coupled to ground and its drain is coupled to node 20. The source of transistor 84 is coupled to the output of inverter 82, and the drain of transistor 84 is coupled to the source of transistor 88. The gate of transistor 88 is coupled to receive a carry-in signal (C in ), and the drain of transistor 88 is coupled to node 20. Transistor 90 has a source coupled to node 20, a gate coupled to control signal ALUL and a drain coupled to node 93. P-Channel field-effect-transistors 89 and 91 each have a source coupled to V D and a drain coupled to node 93. The gate of transistor 91 is coupled to receive the clock signal (CL), while the gate of transistor 89 is coupled to the output of inverter 92 which has an input coupled to node 93. The carry-out signal (C out ) appears at the output of inverter 92. The inventive ALU includes an output section comprising P-channel field-effect-transistors 57, 59, 61 and 63 N-channel field-effect-transistors 60, 62, 66, 68, 70 and 72, and inverters 58, 64, 76, and 78. The output of inverter 78 is coupled to output node 28 and to the input of inverter 76 while the output of inverter 76 is coupled to node 26 and to the input of inverter 78. Thus, inverters 76 and 78 form a latch 74. Transistors 57 and 59 each have a source coupled to a source of supply voltage V D and a drain coupled to node 12 (the input of inverter 58). The gate of transistor 59 is coupled to receive the clock signal (CL). The output of inverter 58 is coupled to the gate of transistor 57, to the input of inverter 82 and to node 14. Transistor 61 has a source coupled to V D , a drain coupled to the source of transistor 63, and a gate coupled to node 16. The drain of transistor 63 is coupled to node 12, and its gate is coupled to receive (S1 . S2). The input of inverter 64 receives the carry-in signal (C in ) and has an output coupled to the gate of transistor 62 and to the source of transistor 60. The source of transistor 62, the gate electrodes of transistors 60 and 70, and the source electrode of transistor 68 are coupled to node 14. The source of transistor 70 and the gate of transistor 68 are coupled to receive the carry-in (C in ) signal. The drain electrodes of transistors 60 and 62 are coupled to node 22, and the drain electrodes of transistors 68 and 70 are coupled to node 24. Both transistors 66 and 72 have gate electrodes coupled to receive a clock signal (CL). The source of transistor 66 is coupled to node 22, and the source of transistor 72 is coupled to node 24. The drain of transistor 66 is coupled to node 28, while the drain of transistor 72 is coupled to node 26. As stated previously, the circuit will perform AND, OR, exclusive OR, and add functions. The particular function to be performed is selected by properly selecting the states of control signals S1, S2 and ALUL. Table 1 indicates the respective states of control signals S1, S2 and ALUL in order to achieve a particular function each of which will be described separately below. In addition to the conditions specified in TABLE 1, for the AND, OR and exclusive OR functions, the carry-in signal (C in ) will be assumed to be low. If an add function is selected, C in may vary between logical low and logical high states. Finally, for each of the functions described in TABLE 1, special signal ALB is assumed to be high. Thus, transistors 36 and 42 will, for the time being, be assumed to be on. TABLE 1______________________________________ S1 S2 ALUL______________________________________AND 0 1 0OR 1 0 0Exclusive OR 1 1 0Add 1 1 1______________________________________ AND An AND function requires that a high output be generated when both inputs A and B are in logical high states. If both A and B are high, transistors 30, 32, 34 and 40 are on. The OR and exclusive OR functions of the circuit are disabled since transistors 48, 50, and 54 are off. The AND function is enabled by S1 and S2 turning transistors 44 and 46 on. When the clock signal CL goes low, transistor 59 turns on causing node 12 (the input of inverter 58) to be precharged to V D (a logical high). Input A is always low while clock signal CL is low to allow precharging of nodes 12 and 16. However, when transistors 32, 34 and 36 turn on, as clock signal CL goes high node 12 is discharged causing a high to appear at the output of inverter 58 (node 14) under this condition and since C in is low (the output of the inverter 64 is high), transistors 60, 62 and 70 turn on and transistor 68 turns off. Transistors 66 and 72 are turned on causing latch 74 to be set. That is, a logical high appears at the output of inverter 78 while the logical low appears at the output of inverter 76. Thus, the desired logical high output at node 28 has been achieved. That portion of the circuit dealing with the generation of a carry-out signal is disabled since transistor 90 remains off. The input of inverter 92 (node 93) was precharged when the clock signal was low by causing transistor 91 to turn on. Thus, the output of inverter 92 remains low. If input A were to equal a logical low after clock signal CL went high, transistor 32 would remain off. Since no path is established to discharge node 12, the input of inverter 58 would remain high causing a low voltage to appear at node 14. With a low voltage at node 14 and C in equal to a logical low, transistor 62 is turned on causing a low voltage to be applied to the source of transistor 66. When the clock signal goes high turning transistor 66 on, a low voltage is applied to node 28 resetting latch 74 and producing the required low output. Similarly, if input B goes low, transistor 34 turns off causing node 14 to remain low as previously described. OR Since control signals S1 and S2 are high and low respectively, transistors 48 and 50 are turned on. The AND and exclusive OR functions are disabled because transistors 44, 46 and 56 are off. When A is high and B is low, transistor 30 will turn on and transistor 40 will turn off causing a low voltage to be applied to node 10 and, via transistors 48 and 50, to node 12. Thus, a high voltage will appear at node 14 causing latch 74 to be set as previously described. Should A equal "0" and B equal "1", transistors 30 and 32 turn off and transistor 40 turns on. With transistors 40 and 42 on, a low voltage will be applied to node 10 when the clock signal (CL) turns transistor 38 on. This low voltage will again be applied to node 12 via transistors 48 and 50 causing node 14 to go high. Again, latch 74 is set as previously discussed. Therefore, when either A or B is high, a high output is produced as is consistent with a typical OR function. On the other hand, should both A and B be low, transistors 30, 32, 34 and 40 remain off. Thus, there is no path for discharging the high voltage set up at node 12 by transistor 59. This will cause a low voltage to appear at node 14 resetting latch 74 as previously described. Exclusive-OR An exclusive-OR function requires that the output go high when either of the inputs (A or B) is high and low when both inputs are either high or low. Beginning with the input condition A=1 and B=0, transistor 30 turns on and transistor 34 turns off. Since both S1 and S2 are high, transistor 44 is off, transistor 50 is off and transistors 54 and 56 are on. Thus, the AND path (transistor 44 and 46) and the OR path (transistors 48 and 50) are disabled. With transistors 52, 54 and 56 on, the low voltage appearing at node 10 is transmitted to node 12 causing a high to appear at node 14. (Transistor 52 is on since transistor 34 is off.) This results in latch 74 being set causing a high output as desired. When A=0 and B=1, transistors 30 and 32 turn off and transistor 40 turns on. When transistor 38 turns on as a result of the clock signal CL going high, a low voltage is applied to node 10 and transmitted to node 12 via transistors 52, 54 and 56. (Transistor 52 is on since transistor 32 is off). The low voltage at node 12 causes a high voltage to appear at node 14 setting latch 74 as desired. Should both A and B be in their logical high states, transistors 32 and 34 are on and transistor 52 turns off. With transistor 52 off, there is no discharge path for node 12. The two P channel transistors (61 and 63) connected in series between V D and node 12 re-instate the high level on node 12 causing node 14 to remain low. This will cause latch 74 to be reset as previously described. Similarly, should both A and B be in their logical low states, transistors 30, 32, 34 and 40 are off. Again, there is no discharge path for node 12 and latch 74 remains reset as desired. ADDITION In the addition mode, the ALU operates on three inputs; i.e. input A, input B and the carry-in signal (C in ). As is well known, if only one of the input signals is high, the output of the circuit should go high with no carry-out. If two of the three inputs are high, the output of the circuit should go low and a carry-out generated. If all three inputs are high, both the circuit output and the carry-out should go high. To enter the addition mode, control signals S1 and S2 along with ALUL are set high. Thus, node 10 is coupled to node 12 via transistors 54 and 56 since transistors 44 and 50 are maintained in an off condition. Assuming at first that all input signals are low (i.e. A=B=C in =0), transistors 30, 32, 34 and 40 remain off. With no discharge path between the ground supply and node 12, node 14 remains low causing the output of latch 74 to be low as previously described. Furthermore, node 16 has been precharged by transistor 81 to a high voltage causing a low voltage to appear at the output of inverter 80. This low voltage is further enhanced by field-effect-transistor 79 since when the output of inverter 80 is low, transistor 79 turns on oausing the voltage at the input of inverter 80 to remain high. A similar function is performed by P-channel field-effect-transistors 57 and 89. A low voltage at the output of inverter 80 causes transistor 86 to remain off. Furthermore, since the carry-in signal is low, transistor 88 remains off. Thus, there is no discharge path for node 93 which has been precharged to a high state by transistor 91. As a result, the output of inverter 92 (C out ) remains low. If only input A goes high, transistor 30 will turn on causing a low voltage to appear at node 10. Transistor 52 is on due to the precharge at node 16, and transistors 54 and 56 are on due to the state of control signals S1 and S2. Therefore, the low voltage appearing at node 10 is transmitted to node 12 causing the output of inverter 58 to go high. The high voltage at node 14 will cause the output of latch 74 to go high as previously described. The state of the carry-out signal however remains unchanged. If only input B goes high, transistors 34 and 40 turn on. When the clock goes high, transistor 38 will turn on and since transistor 42 is on, a low voltage will be transmitted to node 10. This low voltage will cause the voltage at node 14 to go high via transistors 52, 54, 56 and inverter 58 as previously described. The high voltage at node 14 will cause the output of latch 74 (or node 28) to go high. The state of the carry-out signal remains low. If both the A and B input signals are low and the carry-in signal is high, node 12 will remain in the high state since no discharge path has been completed. Thus, a low voltage will appear at node 14. However, due to the fact that the carry-in signal is high, transistor 62 turns off and transistor 68 turns on. With transistor 68 on, the low voltage appearing at node 14 is transmitted to the source of transistor 72. When transistor 72 is turned on by the clock pulse CL, node 26 goes low causing the output of the latch 74 (node 28) to go high. While the presence of a high carry-in signal causes transistor 88 to turn on, no discharge path for node 93 has been established and therefore the output of inverter 92 (C out ) remains low. The next situation to be described is that wherein either input A or input B is high and the carry-in signal C in is high. With either A or B high, a high will appear at node 14 (the output of inverter 58) as has been previously described. In the previous situations with C in low, the high voltage at node 14 would result in a high voltage at node 28 (the output). In this case however (i.e. C in high and node 14 high), transistor 60 turns on thus coupling the low voltage at the output of inverter 64 to node 22. When transistor 66 turns on (when the clock signal CL goes high) node 28 goes low and the latch is reset. Thus, the output signal is low. Because node 14 is high, a low voltage appears at the output of inverter 82. Since node 16 is high, transistor 84 turns on, and C in turns transistor 88 on thus causing a low voltage to appear at node 20. Since control signal ALUL is high, transistor 90 is turned on thus discharging node 93 (the input of inverter 92). As a result, the output of inverter 92 goes high producing a high carry-out signal (C out ). In the case where both inputs A and B are high and the carry-in signal (C in ) is low, transistors 32, 34 and 36 are on discharging node 16 and causing transistor 52 to turn off. The two series connected P-channel transistors (61 and 63) between V D and node 12 are turned on to re-instate the high level on node 12. Thus, node 12 remains high and node 14 remains low. With node 14 low and C in low, latch 74 is reset producing a low voltage at output node 28. Since node 16 has been discharged, a high voltage appears at the output of inverter 80 causing transistor 86 to turn on thereby grounding node 20. Since transistor 90 is on (ALUL is high) node 93 is discharged producing a high signal at the output of inverter 92. Thus, the carry-out signal C out is high. If all inputs (i.e. A, B and C in ) are high, it is necessary that latch 74 be set and a carry-out signal generated. This is accomplished as follows. With transistors 32, 34 and 36 on, transistor 52 remains off thus preventing node 12 from being discharged. Thus a low voltage appears at node 14. With node 14 low and the carry-in signal high, both transistors 60 and 62 remain off. However, transistor 68 turns on causing a low voltage at node 14 to be applied to node 24. When transistor 72 turns on as a result of the occurrence of clock signal CL, node 26 goes low causing output node 28 to go high. Since node 16 has been discharged through transistors 32, 34 and 36, the high voltage is applied to the gate of transistor 86 turning it on. Since transistor 90 is on, node 93 is discharged placing a low voltage at the input of inverter 92. The output of inverter 92 (C out ) will go high. Transistor 84 is turned off to prevent a conflict between transistor 86 and inverter 82. The above description is given by way of example only. Changes in form and details may be made by one skilled in the art without departing from the scope of the invention as defined by the appended claims. DISABLING INPUT B The ALB control signal may go to a low level to turn off transistors 36 and 42. In this case, the ALU functions as if input B were a low level, but otherwise the ALU functions as described previously.

An arithmetic logic unit capable of performing AND, OR, exclusive-OR, and add functions is implemented utilizing strobed gates. An input section receives first and second inputs, each capable of assuming first and second states, and generates a first output indicating that at least one of the inputs is in a first state and a second output indicating that both inputs are in the first state. First, second and third strings of field-effect-transistors controlled by a plurality of control signals are selectively enabled respectively when at least one of the inputs is in the first state, all of the inputs are in the first state, or when only one of the inputs is in the first state. The circuit includes an output section and a circuit for generating a carry-out signal when the inputs so require.

BACKGROUND [0001] Inductive devices, such as transformers and inductors provided by coils are often included in small scale, medium scale, or very large scale integration (VLSI) circuits. Typically, inductive devices integrated in these circuits use large coil diameters to obtain a good quality factor (i.e., Q-factor). A good Q-factor is especially important for radio frequency (RF) technology applications. Large diameter coils, however, typically use a large percentage of the available substrate area of an integrated circuit and therefore increase production costs. [0002] Concentric coils are typically located in parallel to a substrate surface. The coils are fabricated in back end of line (BEOL) processing during a metallization process using suitable metallization material. Typically, the coils may consume 50% or more of the total chip area. In addition, the inductivities achieved from the coils are usually not suitable for applications in which the coils will be used not only for signal transmission but also for power transmission. [0003] For these and other reasons, there is a need for the present invention. SUMMARY [0004] One embodiment provides an integrated circuit. The integrated circuit includes a substrate and an inductive device on a first side of the substrate. The integrated circuit includes a first ferromagnetic material on a second side of the substrate opposite the first side. BRIEF DESCRIPTION OF THE DRAWINGS [0005] The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present invention and together with the description serve to explain the principles of the invention. Other embodiments of the present invention and many of the intended advantages of the present invention will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. [0006] FIG. 1 illustrates a cross-sectional view of one embodiment of an integrated circuit including an inductive device encased in ferromagnetic material. [0007] FIG. 2 illustrates a cross-sectional view of another embodiment of an integrated circuit including an inductive device encased in ferromagnetic material. [0008] FIG. 3 illustrates a cross-sectional view of another embodiment of an integrated circuit including an inductive device encased in ferromagnetic material. [0009] FIG. 4 illustrates a cross-sectional view of another embodiment of an integrated circuit including an inductive device encased in ferromagnetic material. [0010] FIG. 5 illustrates a cross-sectional view of another embodiment of an integrated circuit including an inductive device encased in ferromagnetic material. DETAILED DESCRIPTION [0011] In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. [0012] FIG. 1 illustrates a cross-sectional view of one embodiment of an integrated circuit 100 a . Integrated circuit 100 a includes a substrate 102 , inductive devices 104 a and 104 b , dielectric material 106 , first ferromagnetic material 108 , and second ferromagnetic material 110 . In other embodiments, integrated circuit 100 a includes any suitable number of inductive devices. [0013] First ferromagnetic material 108 and second ferromagnetic material 110 partially or fully encase or enclose inductive devices 104 a and 104 b . The ferromagnetic material can be applied using suitable semiconductor processing techniques during front end of line (FEOL) processing and/or back end of line (BEOL) processing. The ferromagnetic material can be positioned above inductive devices 104 a and 104 b , below inductive devices 104 a and 104 b , and/or on the sides (inner and outer) of inductive devices 104 a and 104 b. [0014] First ferromagnetic material 108 and second ferromagnetic material 110 confine the magnetic flux inside inductive devices 104 a and 104 b . The confining of the magnetic flux inside inductive devices 104 a and 104 b reduces energy dissipation from inductive devices 104 a and 104 b due to leakage fields and magnetic coupling to silicon substrate 102 . By reducing the energy dissipation in this way, the quality factor (i.e., Q-factor) of inductive devices 104 a and 104 b is increased. By increasing the Q-factor of inductive devices 104 a and 104 b , inductive devices 104 a and 104 b can be used for both signal transmission and power transmission. [0015] Inductive devices 104 a and 104 b are formed in metallization layers on substrate 102 using suitable metallization materials. In one embodiment, inductive devices 104 a and 104 b are concentric coils providing inductors, transformers, or other suitable devices. Dielectric material 106 surrounds the metal material forming inductive devices 104 a and 104 b . In one embodiment, substrate 102 is a silicon substrate. The thickness of substrate 102 is less than the diameter of inductive devices 104 a and 104 b . In one embodiment, grinding is used to reduce the thickness of substrate 102 to between approximately 60-100 μm. [0016] Ferromagnetic material, such as Co, Fe, Ni, or other suitable ferromagnetic material is deposited on the backside of substrate 102 . The ferromagnetic material is structured using suitable lithography processes to provide gaps 116 between portions of first ferromagnetic material 108 . Gaps 116 between portions of first ferromagnetic material 108 are provided to prevent eddy currents. Because silicon substrate 102 has a low electrical conductivity, magnetic coupling of the magnetic field of inductive devices 104 a and 104 b into substrate 102 is low. Therefore, first ferromagnetic material 108 shields the magnetic field of inductive devices 104 a and 104 b. [0017] Ferromagnetic material, such as Co, Fe, Ni, or other suitable ferromagnetic material is deposited on the top and sides of inductive devices 104 a and 104 b . In one embodiment, the ferromagnetic material is structured using suitable lithography processes to provide second ferromagnetic material 110 . Second ferromagnetic material 110 includes first portions 112 and second portions 114 . First portions 112 are provided on top of inductive devices 104 a and 104 b . Second portions 114 are provided on the outer sidewalls of dielectric material 106 surrounding inductive devices 104 a and 104 b . In one embodiment, second portions 114 are also provided on the inner sidewalls of dielectric material 106 surrounding inductive devices 104 a and 104 b . In one embodiment, the sidewalls of dielectric material 106 surrounding inductive devices 104 a and 104 b are perpendicular to first portions 112 . In another embodiment, the sidewalls of dielectric material 106 surrounding inductive devices 104 a and 104 b are sloped. [0018] FIG. 2 illustrates a cross-sectional view of another embodiment of an integrated circuit 100 b . Integrated circuit 100 b includes substrate 102 , first ferromagnetic material 120 , inductive devices 104 a and 104 b , dielectric material 106 , and second ferromagnetic material 122 and 124 . In this embodiment, first ferromagnetic material 120 is provided between inductive devices 104 a and 104 b and substrate 102 . First ferromagnetic material 120 is formed in a metallization layer on substrate 102 . Since first ferromagnetic material 120 is between inductive devices 104 a and 104 b and substrate 102 , in this embodiment the thickness of substrate 102 can be greater than the diameter of inductive devices 104 a and 104 b. [0019] Second ferromagnetic material 122 is printed over inductive devices 104 a and 104 b . In one embodiment, second ferromagnetic material 122 is printed using an inkjet printer or other suitable printer. Next, a galvanic process is used to optimize or enhance the printed ferromagnetic material 122 and to provide ferromagnetic material 124 . The galvanic process is selected to provide a combination of ferromagnetic material 122 and 124 providing desired ferromagnetic properties. Ferromagnetic materials 122 and 124 include first portions 126 and second portions 128 . First portions 126 are provided on top of inductive devices 104 a and 104 b . Second portions 128 are provided on the outer sidewalls of dielectric material 106 surrounding inductive devices 104 a and 104 b . In one embodiment, second portions 128 are also provided on the inner sidewalls of dielectric material 106 surrounding inductive devices 104 a and 104 b . In this embodiment, the sidewalls of dielectric material 106 surrounding inductive devices 104 a and 104 b are sloped such that a printer can print ferromagnetic material 122 on the sidewalls. First ferromagnetic material 120 and second ferromagnetic material 122 and 124 provide a similar function as first ferromagnetic material 108 and second ferromagnetic material 110 previously described and illustrated with reference to FIG. 1 . [0020] FIG. 3 illustrates a cross-sectional view of another embodiment of an integrated circuit 100 c . Integrated circuit 100 c is similar to integrated circuit 100 b previously described and illustrated with reference to FIG. 2 , except that in integrated circuit 100 c first ferromagnetic material 120 is replaced with first ferromagnetic material 108 . First ferromagnetic material 108 is deposited and structured on the backside of wafer 102 as previously described and illustrated with reference to FIG. 1 . First ferromagnetic material 108 and second ferromagnetic material 122 and 124 provide a similar function as first ferromagnetic material 108 and second ferromagnetic material 110 previously described and illustrated with reference to FIG. 1 . [0021] FIG. 4 illustrates a cross-sectional view of another embodiment of an integrated circuit 100 d . Integrated circuit 100 d includes substrate 102 , first ferromagnetic material 120 , inductive devices 104 a and 104 b , a ferromagnetic mold material 130 , and an encapsulating mold material 132 . In this embodiment, first ferromagnetic material 120 is provided between inductive devices 104 a and 104 b and substrate 102 . First ferromagnetic material 120 is formed in a metallization layer on substrate 102 . Since first ferromagnetic material 120 is between inductive devices 104 a and 104 b and substrate 102 , in this embodiment the thickness of substrate 102 can be greater than the diameter of inductive devices 104 a and 104 b. [0022] In addition, inductive devices 104 a and 104 b are encased or enclosed with ferromagnetic mold material 130 . In one embodiment, ferromagnetic mold material 130 includes a suitable molding compound mixed with ferrite or other suitable material to provide a ferromagnetic mold material. The ferromagnetic mold material is applied over the top and sidewalls of dielectric material 106 and inductive devices 104 a and 104 b using a suitable molding process. A suitable non-ferromagnetic encapsulation mold material 132 encapsulates ferromagnetic mold material 130 and substrate 102 . First ferromagnetic material 120 and ferromagnetic mold material 130 provide a similar function as first ferromagnetic material 108 and second ferromagnetic material 110 previously described and illustrated with reference to FIG. 1 . [0023] FIG. 5 illustrates a cross-sectional view of another embodiment of an integrated circuit 100 e . Integrated circuit e is similar to integrated circuit 100 d previously described and illustrated with reference to FIG. 4 , except that in integrated circuit e first ferromagnetic material 120 is replaced with first ferromagnetic material 108 . First ferromagnetic material 108 is deposited and structured on the backside of wafer 102 as previously described and illustrated with reference to FIG. 1 . First ferromagnetic material 108 and ferromagnetic mold material 130 provide a similar function as first ferromagnetic material 108 and second ferromagnetic material 110 previously described and illustrated with reference to FIG. 1 . [0024] Embodiments provide inductive devices embedded in ferromagnetic material. The ferromagnetic material shields the inductive devices thereby increasing the inductivities and Q-factors of the inductive devices. By increasing the Q-factors of the inductive devices, the inductive devices can be used for both signal transmission and power transmission in small scale, medium scale, or very large scale integration circuits. [0025] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.

An integrated circuit includes a substrate and an inductive device on a first side of the substrate. The integrated circuit includes a first ferromagnetic material on a second side of the substrate opposite the first side.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. application Ser. No. 10/382,648, filed Mar. 7, 2003. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates generally to methods and apparatus for mixing and dispensing caulking compounds and more particularly to tinting caulking compound that has been dispensed into prepackaged containers to match a selected color of paint. [0004] 2. Related Art [0005] Caulking compounds are used to join, for example, wood or synthetic trim to painted surfaces; laminates at their seams or to walls; sinks to counters; flooring to painted, laminated or wood surfaces; and so on. Caulking compounds are generally used to caulk joints where a waterproof seal is needed in the joint and which can be subsequently painted if necessary. Most caulking compounds are generally white or off-white tending toward a gray color which is the natural color of most caulking compounds, although some limited quantities of black or special order quantities of colors are available. The colored compounds, i.e. those other than white, cannot generally be commercially obtained except in very large quantities upon special order from the manufacturer. The reasons for this is that there is not a great deal of a demand for large quantities of particular colors of colored caulking compounds and it is therefore impractical for a caulking compound manufacturer to produce large quantities of tinted caulking compounds having various colors and shades. [0006] Therefore, such tinted caulking compounds are generally not available for small users such as home owners and smaller commercial construction companies whose volume of use is not sufficient to warrant special orders of a particular tinted color of caulking compound. There is a desire, however, on the part of the purchasing public to have caulking compounds of various colors. [0007] In the use of certain materials such as caulking or other sealing materials which are sold in plastic dispensing tubes such as LIFETIME® Adhesive Sealant, it is often desirable to color the material to match, e.g., the wall color being applied to a room. For example, in the use of conventional white caulking material, as soon as the material sets up sufficiently, usually about two hours or longer, the material can be painted the same color as the room. Where the paint is of a light shade in particular, it may be difficult to cover the material completely without multiple paint coats. Also, it is often necessary to do some additional caulking after the final coat of paint is applied. In that event, the white caulking is painted over as the final step. The advantage of having color matched caulk is that a great saving of time is possible. The user does not have to apply the paint itself with precision at joining edges or, alternatively, does not have to paint over white caulk previously applied. The user may first paint next to, but not exactly on, the joint and then afterwards fill in the unpainted surface with caulk. [0008] Consequently, some paint dealers have undertaken to mix colorant into the caulking material by hand for certain customers, but considerable time and effort is involved and often results in inferior mixing and considerable clean up time. The problem is that, unlike paint, caulk is very viscous. Therefore, there are problems in mixing the tinting agent with the caulk and in dispensing the caulk into the tubes which are used in caulk guns, since it cannot readily be poured. There is presently no economical means available of supplying this needed product since manufacturers of the caulking compounds cannot maintain sufficient variety of inventory or small quantities of caulking compound to suit the consumer needs. [0009] Thus, there is a need for an apparatus and method which allows the contractor or the home hobbyist to purchase tubes of caulk and add colorant to the caulk to duplicate the color of their paint, tile, laminate, or the like. There is also a need for a quick, effective, convenient and cleaner method and apparatus for substantially automatically performing the mixing operation. BRIEF SUMMARY OF THE INVENTION [0010] A method for tinting caulk is provided. In an exemplary embodiment of the invention, the method comprises: providing an amount of caulk, wherein the caulk is white in color prior to curing and clear after curing; providing a cylindrical cartridge to contain the caulk, wherein the cartridge comprises a substantially cylindrical body, having a dispensing end and a fill end, a removable and replaceable end-cap adapted to be received in the fill end, a dispensing tip coupled to the dispensing end, and a breakable seal located between the tip and the body, and wherein the body is sufficiently clear throughout its length so as to allow the color of caulk contained within the cartridge to be viewed; providing a mixing tool having a mixer head means having seal means adapted to be brought into static engagement with wall portions of the body adjacent the fill end to lock the head means to the body and to prevent leakage of the caulk from the body during a mixing operation, bore means formed thru the seal means substantially on a longitudinal axis of the body, elongated shaft means mounted thru the bore means for both rotational and axial motion relative to the seal means and the body, the shaft means having a proximal end lying axially outwardly of the seal means and having a distal end lying within the body, mixer impeller means mounted on the distal end and having peripheral portions adapted to lie closely adjacent to an inner surface of the body, power means for rotating the shaft means and impeller means relative to the cartridge; filling the cartridge with the caulk to a level sufficient to allow room for the shaft of the mixing tool to be inserted into the cartridge without causing caulk to overflow from the cartridge; adding coloration for the caulk comprising an amount of paint having the desired color of the caulk, or in the alternative, where paint of the desired color is unavailable, adding color tint corresponding to the desired color of caulk, along with an amount of white paint; affixing the mixing tool to the fill end of the body, when the end-cap is not in place, such that the shaft of the mixing tool is disposed within the cartridge and such that the seal means of the tool sealingly engages the fill end of the body; applying force to the shaft of the mixing tool such that the colorant and caulk in the cartridge is mixed; breaking the seal between the tip and the body of the cartridge; sealingly engaging the end-cap to the fill end of the cartridge; and applying the tinted caulk to an intended substrate. [0011] In another embodiment of the invention, a caulk product is provided. The product comprises an amount of caulk that is formulated so as to be white in color prior to curing and clear after curing. A cylindrical cartridge contains the amount of caulk, wherein the cartridge comprises a dispensing tip, a substantially cylindrical body, a removable and replaceable end-cap, and a breakable seal located between the tip and the body. A transparent area is disposed within a wall of the cartridge so as to allow the color of the caulk to be viewed, wherein the area defined by the cartridge body is adapted to accommodate the insertion of colorant and a mixing tool without overflow. [0012] In a further embodiment, the amount of caulk contained in the cartridge is selected so that the caulk occupies no more than 95% of the total volume capacity of the area defined by the cartridge body, seal, and end-cap when the end-cap is in place. [0013] In a further embodiment, the transparent area extends the length throughout the length of the cartridge. [0014] Further objectives and advantages, as well as the structure and function of preferred embodiments will become apparent from a consideration of the description, drawings, and examples. BRIEF DESCRIPTION OF THE DRAWINGS [0015] The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. [0016] FIG. 1 depicts a perspective view of a materials container in cartridge form according to an exemplary embodiment of the present invention; [0017] FIG. 2 depicts a side view in elevation, in partial cross-section and broken away, of the cartridge of FIG. 1 ; [0018] FIG. 3 depicts a longitudinal cross-section view of a mixer apparatus according to an exemplary embodiment of the present invention; [0019] FIG. 4 depicts a cross-section view of the proximal end of the cartridge and a mixing head including a cartridge holder; and [0020] FIG. 5 depicts a cross-section view of a mixer apparatus according to another embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION [0021] Embodiments of the invention are discussed in detail below. In describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. While specific exemplary embodiments are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations can be used without parting from the spirit and scope of the invention. All references cited herein are incorporated by reference as if each had been individually incorporated. [0022] Embodiments of the present invention concern a method and apparatus for mixing any of a wide variety of liquid or particulate materials such as colorant, e.g., pigment or organic dye, sand, grout, catalyst for two-part caulking, or the like, preferably in solution or suspension form, into viscous work material, particularly caulking compound, wherein the structural mixing components are of unique but simple design and are adapted to accomplish the mixing very rapidly and directly within the work material retail container, i.e., in-situ. [0023] In FIG. 1 , an embodiment of the present invention is shown as a caulking tube or container 10 in the form of an elongated tubular housing 12 which is preferably cylindrical in shape, but which could take a variety of cross-section geometric shapes, if desired. Tubular housing 12 has a generally hollow interior 14 that is closed at one end, a dispensing end, by an end wall 16 including a nozzle assembly 18 , as is known in the art. Nozzle assembly 18 includes an elongated dispensing tip 20 . Housing 12 is enclosed at an end opposite end wall 16 , a fill end, by a end cap 22 which is slideably received in interior 14 so that it has a peripheral edge surface 24 that abuts the interior surface 48 of surrounding side wall 26 that forms tubular housing 12 . As described more thoroughly below, at least a portion of side wall 26 is transparent. [0024] The construction of container 10 is shown in greater detail in FIG. 2 . As is shown in FIG. 2 , container 10 receives a caulking compound 32 which is preferably opaque and, in one embodiment, consists of an acrylic terpolymer including ethylacryate, acrylonitrile, and acrylic acid which physically vulcanizes by immobilization into a clear substance. The caulking compound is also preferably greater than 60% solids. The caulking compound is tintable such that the caulk is colored by the addition of a colorant. Housing 12 is enclosed at the dispensing end by end wall 16 which, in one embodiment, is in the form of a metal cap having a lip 34 that is secured onto the edge of housing 12 as is known in the art. End wall 16 has a central port 36 , shown in phantom, and is provided with nozzle assembly 18 that includes elongated tip 20 . Tip 20 has a passageway 38 extending longitudinally therethrough with tip 20 being somewhat conical in shape so that side wall 40 of tip 20 diminishes in cross-section from end wall 16 to free end 42 of tip 20 . Passageway 38 is in fluid communication with the interior 14 of housing 12 , but a seal 21 interrupts this fluid communication. Prior to use, however, seal 21 is broken to establish the outlet path for the compound 32 . The provision of seal 21 allows for more complete mixing of the caulk in the container, as described below. [0025] In the illustrated embodiment, an end cap 22 seals the caulking material in the interior 14 of the housing 12 . The end cap 22 is removable so that colorant can be mixed with the caulk in the housing 12 . As mentioned above, at least a portion of the housing 12 is sufficiently clear so that the color of the caulk contained within the interior 14 can be viewed. The housing 12 may be clear along its entire length. A label including product information may be applied to the side wall 26 . The label may include a window 28 extending along the length of the housing 12 , through which the color of the caulk can be viewed. The user can also observe through the window or through the clear housing if the colorant is uniformly mixed and distributed throughout the caulk. [0026] The end cap 22 can be replaced on the housing after the colorant is added and can act as a piston member slideably received in the open interior 14 of housing 12 . As is shown in FIG. 2 , end cap 22 is cup-shaped in configuration so that it has a flat base plate 44 which bears against caulking material 32 . To this end, end cap 22 has a side wall 46 which slideably engages interior surface 48 of side wall 26 . Accordingly, the outer surface of side wall 46 defines peripheral surface 24 which slideably engages surface 48 . [0027] It should thus be appreciated that, when tip 30 is severed at a selected location along its length, a circular or oval outlet is formed for caulking material 32 since passageway 38 is in fluid communication with hollow interior 14 through port 36 in end wall 16 . Accordingly, when end cap 22 is forcibly moved from the upstream location shown in FIG. 2 to the downstream location shown in phantom in FIG. 2 , caulking material 32 is expelled as a rope-like bead from the outlet formed in tip 20 . This rope-like bead has dimensions which correspond to the dimensions of the outlet. Since surrounding side wall 26 is transparent, the material which remains in cartridge 10 is defined by the position of base plate 44 . [0028] A mixing apparatus that may be used to mix the colorant with the caulk is described in co-pending U.S. patent application Ser. No. 10/293,850, which is incorporated herein by reference. With reference to the embodiments shown in FIGS. 3 and 4 , the mixing apparatus in its generic sense comprises mixer head means of metal or plastic material and generally designated 50 having a housing end seal means generally designated 52 adapted to be brought into static engagement by pressure cap means generally designated 54 with wall portions such as the top rim 56 of the interior or outer surfaces of the fill end of the housing 12 to prevent leakage of the caulking material from the housing 12 during the mixing operation. Bore means 58 is formed thru the seal means 52 substantially on a longitudinal axis 60 of the housing, and an elongated mixer shaft means 62 is mounted thru 58 for both rotational and axial motion with respect to the seal means 52 and housing 12 . This shaft means 62 has a proximal end 64 lying axially outwardly of the seal means and has a distal end 66 lying within the interior 14 . Mixer impeller means 68 is mounted on the distal end 66 and has a periphery 70 adapted to lie closely adjacent to or in sliding contact with cylindrical inner surface 48 of the tube. The above seal means 52 , bore means 58 , shaft means 62 , impeller means 58 and pressure cap means 54 constitute the basic structure of the head means 50 . Power means may also be provided for rotating the shaft 62 and impeller 68 as they are being moved axially thru the caulking material. [0029] In the embodiment shown in FIGS. 3 and 4 the pressure cap means 54 includes a pressure cap section 70 . In the embodiment of FIG. 4 , when pressure cap section 70 is forced down onto the seal means 52 , the seal means 52 will seal the housing 12 . [0030] Shaft means 62 is rotatably mounted through seal body 72 in the embodiment shown, which body is preferably provided with a mixer shaft seal 74 such as an O-ring or other annular ring type seal of composition and configuration which affords an axially sliding seal as well as one which wipes the viscous material from the shaft while reciprocating in the caulking tube. [0031] The upper or proximal end 64 of the shaft preferably is mounted through a rotative power means which can rotate the shaft 64 selectively and substantially instantly in either direction and at any desired rpm, e.g. 600-800 rpm, such that maximum mixing turbulence can be imparted to the work material. Alternatively, the shaft can be reciprocated through the housing by hand, as is described in more detail below. [0032] In FIG. 4 the seal means 52 comprises an elastomeric gripping body 160 having a circular periphery 162 which is dimensioned in diameter to slide down into the end of the housing 12 . A bushing 164 having threads 165 is axially mounted thru bore 58 in body 160 and has its inner end 161 non-rotatably fixed to a plate 166 as by welding at 167 . Shaft 62 is rotatably, slidably mounted thru a bore 168 in the bushing. [0033] In use, shaft 62 is mounted thru bore 168 with the mixer impeller lying adjacent plate 166 . With the mixer impeller then inserted into a tube through the fill end thereof, body 160 is slid into the fill end to a desired position therein. Bushing 164 may be provided with a flat 174 over which a pressure cap 176 of special configuration is mounted. This cap is dimensioned and shaped to slide down over bushing 164 and the open neck 163 of a tube and be held by hand from rotating while nut 172 is tightened against the upper surface 169 of the cap to bulge seal body 160 . The outer cylindrical wall 178 of the cap prevents excessive outward bulging of the tube neck wherein such bulging might be a problem for some tubes having thin or weak walls. Torque arms 180 on nut 172 allow hand tightening thereof. Nut 172 is tightened sufficiently to bulge the body 160 radially outwardly to seal and grip against inner surface 48 of the housing 12 . The elastomeric material of body 160 is selected to allow it to sealingly bulge under just a few pounds of pressure from the tightening nut 172 . [0034] With the seal means 52 and mixer impeller means thus positioned in the tube, and with the colorant injected, e.g., deposited in the tube, on or into the work material by drop bottles, syringe, spatula, gel capsules, color packets, mechanical dispenser, or the like, the tube can be hand held or placed within a holder or carriage, and the shaft 62 rotated either by a power means such as an electric drill having its chuck fixed to 62 . Reciprocation of the mixer head through the work material relative to the caulking tube can be done by power means or by hand to thoroughly mix the colorant and the caulk. [0035] In another embodiment of the invention illustrated in FIG. 5 , shaft 62 is provided with a handle 147 by which a user can reciprocate shaft 62 and impeller 68 without having to rotate the shaft 62 to mix the colorant and the caulk. [0036] Accordingly, the caulking tubes and mixing apparatus described above may be using in a method for tinting caulk. The general procedure for tinting the caulking compound in the preprepared packages of caulking tubes is to first remove the end-cap 22 and add the colorant to the caulk in the housing. It is preferred that the size of the interior of the housing and the amount of caulk provided in the housing are selected to allow the colorant to be added without overflow from the housing. Typically, a standard size housing is filled with about 9.4 ounces of caulk. If there is not sufficient volume in the housing to permit the addition of tinting material, some caulk is removed before adding the colorant. However, care must be taken not to remove too much caulk from the housing. If the total volume of the caulk applied to the substrate is more than about 5% colorant, the quality of the caulk is degraded to a commercially meaningful extent. Preferably, the caulk is about 3% to about 4% colorant. The colorant and the caulk are then mixed, for example with the use of the above-described mixing apparatus. The end cap is replaced and the tinted caulk is dispensed from the tube. [0037] In an exemplary method of the invention, an amount of caulk is provided in a container, for example a caulking tube as described above. The caulking tube should include a transparent portion through which the color of the caulk can be observed. In one embodiment, the tube is substantially opaque as to allow brand information, manufacturer information, and product information to be displayed thereon, except for a transparent window that extends throughout the length of the tube. Also, a seal is provided between the interior of the housing and the dispensing tip. The seal prevents caulk from entering the dispensing tip during mixing, such that the colorant can be evenly mixed through all of the caulk. The caulk may be of a type that is initially opaque or white in color prior to curing and clear after curing. When color is added to the caulk, the caulk takes on the color of the colorant after curing. [0038] The end cap 22 is removed from the container, allowing the colorant to be added to the caulk. Typically a tube contains about 9.4 ounces of caulk. About 7.5 to 10 ml of colorant is used to color this amount of caulk. The cartridge is filled with the caulk to a level sufficient to allow room for colorant and the shaft of the mixing tool to be inserted into the cartridge without causing caulk to overflow the cartridge. The colorant for the caulk may comprise an amount of paint having the desired color of the caulk, or in the alternative, where paint of the desired color is unavailable, a color tint corresponding to the desired color of the caulk. If necessary, an amount of white paint may be added to the caulk to fine tune its color. Of course, any other kind of colorant that is compatible with the caulk may be used to color the caulk. [0039] A mixing tool having a shaft, such as the mixing apparatus described above, is also provided. The mixing tool is affixed to the end of the cartridge with the end-cap removed, such that the shaft of the mixing tool is disposed within the cartridge and such that the circumference of the base of the tool sealingly engages the end of the cartridge. A rotational force is applied to the shaft of the mixing tool such that the colorant and caulk in the cartridge are mixed together. The rotational force may be generated by an electric drill having its chuck affixed to the shaft, by hand, or by other motive force. The shaft may also be reciprocated through the housing. In a hand-operated embodiment, the shaft is rotated as it is reciprocated through the housing, for example, in a screw-like manner. [0040] If a hand-operated mixer is used, the following method may be used to tint the caulk. The shaft 62 and impeller 68 are inserted all the way down into the housing 12 through the caulk such that impeller 68 is proximate end 18 . The shaft 62 and impeller 68 are withdrawn to fill end of the housing, whereby air that was originally entrained in the caulk escapes. The shaft 62 and impeller 68 are reciprocated within the housing between the fill end and the dispensing end about 10-50 times, whereby the colorant is mixed into the caulk. [0041] After mixing, the mixing apparatus is removed from the housing 12 and the end-cap 22 is sealingly engaged to the end of the housing. The seal between the dispensing tip and the interior of the housing is broken, allowing the caulk to pass out of the housing. The tinted caulk can then be dispensed from the container in a manner know in the art and applied to an intended substrate. [0042] Accordingly, an apparatus and method which allows the contractor or the home hobbyist to purchase tubes of caulk and add colorant to the caulk to duplicate the color of their paint, tile, laminate, or the like is provided. There is also provided a quick, effective, convenient and cleaner method and apparatus for substantially automatically performing the mixing operation. [0043] The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. All examples presented are representative and non-limiting. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, with the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.

A caulk product is provided. The product comprises an amount of caulk that is formulated so as to be white in color prior to curing and clear after curing. A cylindrical cartridge contains the amount of caulk, wherein the cartridges comprises a dispensing tip, a substantially cylindrical body, a removable and replaceable endcap, and a breakable seal located between the tip and the body. A transparent area is disposed within a wall of the cartridge so as to allow the color of the caulk to be viewed, wherein the area defined by the cartridge body is adapted to accommodate the insertion of colorant and a mixing tool without overflow. A related method for coloring caulk is also provided.

CROSS REFERENCE TO OTHER APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application, Serial No. 60/181,295, filed Feb. 9, 2000. BACKGROUND OF THE INVENTION [0002] Today encryption is under-used and privacy issues often become relegated to the hope that no one may intercept otherwise confidential information on the internet all for the sake of convenience. [0003] To be addressed in this invention are electronic communication confidentiality issues that traditionally to a fault and currently exist wherein privacy or semi-private usage of Internet sites and digital communications such as electronic mail and voice mail systems are concerned. Highly secure encryption platforms have been cumbersome to apply broadly and inexpensively without having all parties using the same software. Virtual private networks currently attempt to approach some of these issues but to date have been inaccessible from outside hard wired facilities without installing special software on specific hardware having Internet capabilities. This results in difficult access from outside by privileged parties. To a fault virtual private networks have relied on firewalls creating a closed architecture. Secure digitally based communications, i.e. electronic voice communications and mail have relied upon all parties having the same software installed on their hardware for encryption processing. A goal of the current invention is to overcome these problems. [0004] The major potential benefit of encryption is that it allows users the ability to store or transfer digital information in a form that does not allow that information to be revealed to third parties. Encryption technology allows digital information to be combined with a known series of digits (a key) and then operated upon with a mathematical function in a bit-wise manner, to render the information unintelligible. However, the inverse mathematical function may be applied, in combination with the encryption key, to return the information to its original, readable state. The security of encryption typically depends only upon the secrecy of the key, and not upon the secrecy of the mathematical algorithm. When the same key is used for both encryption and decryption, this is known as a symmetric encryption algorithm. [0005] Public Key encryption differs significantly from symmetric encryption. In Public Key encryption, users maintain two separate but related keys, known as the public key and the private key. Various algorithms are used to derive the two related keys for any given user. To encrypt digital information, the user's public key is combined with a mathematical algorithm and the information, to render the information unintelligible. [0006] Once encrypted with a public key, data may not be decrypted except with the related private key. In this way, a user may distribute one's public key to the general public, and allow them to encrypt data for user purposes. Upon receipt of said data, the user may use a private key, along with a decryption algorithm, to return the encrypted data to its original, readable state. [0007] One problem with Public Key encryption is that, while any person may encrypt data with a user's public key, only the user's private key may be used to decrypt data. If a user wishes to securely share information with another user who does not possess a public key, the first user must encrypt that data with her or his own public key, then allow the second user access to that private key in order to decrypt the data. The major problem with this is that once the second user possesses the first user's private key, the second user may decrypt any data that is ever encrypted with the first user's public key. This does not easily facilitate the exchange of data with users who do not possess their own key pairs. Thus, if many people wish to share data, they must all possess public/private key pairs, and they must exchange public keys among themselves. Only then may each user encrypt data for any other user. Broad-scale public key cryptography is difficult to implement, mainly due to the large infrastructure required to distribute and maintain these keys securely. To date, public key architectures have centered around specific hardware and/or significant memory requiring software dependent applications, meaning that all persons within an information exchange group must all possess the same hardware and/or software on their systems. [0008] A second goal of the present invention through newly described herein unique software, hardware and methods of doing business is based on enabling digital electronic and physical distribution methods for confidential mail, documents, receipts, warranties and goods. These may be used to enable deliveries the same day or some time thereafter of confidential documents and securely protected goods across substantial distances. The systems are to be prompted, organized and enabled through unique electronic software and hardware systems that will address improving the competency and efficiency of electronic and physical mailing systems. [0009] Needs which the systems described in this invention refer to are the need for more efficient flow of physical confidential mail. Also is the need for technology to enable more people to have electronic mail and goods routing conveniences with minimal knowledge of electronic device usage and no or minimal personal hardware. Critical location of and the security of such systems will be essential and would require unique hardware and software to be enabled. SUMMARY OF THE INVENTION [0010] Newly described clueing, encryption and other newly described mechanisms and systems will address the problems associated with gating and controlling authorized access to wired or wireless secure, partially secure and non-secure public, private and semi-private electronic systems. User access to internet sites, semi-private, private or public network systems and all forms of digital electronic communication systems such as voice or tone, telephone networks, telegraphic, fax or electronic mail networks and Internet based sites and servers having confidential protected data would be improved by these systems. [0011] A specific goal of the invention is to describe novel clueing and encryption mechanisms. These are to be applied each solely or in combinations to include non-clued and non-encrypted combinations, and servers for gating and controlling public, semi-private or private access to certain or all confidential data to be accessible through the internet without specific software other than modem browser capabilities. Internet sites, electronic mail systems and sites, (virtual through the Internet or real hardwired) public, semi-private, private network systems will be enabled with selectively penetrable authorized public, private and semi-private portals. Applications of the systems described herein allow an encrypted or non-encrypted non-traceable or traceable environment between a secure or non-secure server and an otherwise secured or unsecured client. This may allow client access to electronic mail whether by Internet or other wireless means of communication including telephone, radio, telegraphy, and other privileges to utilize the capabilities of selected resident server or remote client based programs. This should be able to occur seamlessly and independently of additional client user software beyond standard Internet browser capabilities from any computer anywhere. [0012] Applications of such technology using highly encrypted processes as part of the application compared to today's relatively cumbersome encrypted transmissions would better allay anxiety over security threats for multiple party and business uses. Today's encrypted transmissions generally require expensive, large user memory requirements for specialized software installations by at least two parties. These parties must actively exchange encryption keys or at least have specialized software on each client, which multiplied by several parties who wish to have secure transmissions adds further to the costs and inefficiencies of such systems. [0013] Server-client systems are to be described in the current invention that would allow desirable seamless encryption for electronic mail would also become more functional for those concerned with maintaining privacy yet increasing the utility of their virtual private networks. The current invention calls for having authorized Internet portals through firewalls to enable invited parties to have limited selective penetration. Such a system could allow privileging of multiple users over time to have determinable differentially functional accesses to partial or complete sets of data that might be stored or uploaded to those servers during specified time frames. It would be desirable to enable such encrypted servers to seamlessly allow: access control capabilities for specific complete or partial upload and download privileges and access controlled capabilities for single, dual or multiple party-edit privileges for data transfer and storage via the internet. For larger systems this may require matrix capabilities which would allow prescribed securely encrypted network embodiments with certain components being unencrypted, mixed with possibly otherwise secure and, or unsecured modalities for indelible or transient data storage, transmission and manipulation capabilities. It would further be desirable to have users of such networks enabled by server based systems to allow remote access from any of today's internet browser capable computers independent of any other specific client software or hardware capabilities by simply using authorized portals. [0014] The current problems of privacy and security also have implications in limiting the use of network systems that can be resolved with highly authenticated efficient “digital signatures”. Seamless hardware and software as described in the invention have the capabilities for signature, hashing authentication, and notarization in an encrypted environment. These will become applicable in day to day transactions that would lead to significant improvements concerning rapidity of delivery for confidential commercial and legal applications and for completing such transactions more efficiently and completely. Such benefits become apparent when applied alone or as part of a larger system of authentication of such hashed and authenticated materials potentially requiring or allowing digital signatures and notarizations. This may be exemplified, as is the case when confidential legal documents such as patent applications are to be electronically transmitted electronically to the patent office or any other such document to any other such chosen legal or confidential entity. That may occur directly through pre-arranged hardware and software resident service. Or it may go to a secured intermediary in geographic proximity to the entity that may confidentially print and package such items for immediate delivery to highly trafficked entities that may require printed applications and documents to be provided. [0015] The invention disclosed herein allows users to efficiently at less expense than is associated with biometrics authentication or in conjunction with that technology, to take advantage of public-key encryption and digital signature technologies to encrypt and digitally sign their private information. That information may be stored in encrypted form on internet-resident servers, so that the information is available at all times and from any computer capable hardware that is Internet-enabled. [0016] The invention provides the capability to confidentially and seamlessly integrate upload, download, encryption, and storage functions through a familiar web-browser interface, thus eliminating the need for users to install special hardware and/or software on their computer system. Given this specific hardware and software independence, coupled with a unique method for the distribution and storage of encryption keys, users are freed from dependence upon any single machine from which to access their stored data. Additionally, the unique semi-private key technology, which is an integral component of the invention, allows users to freely distribute subsets of their private, encrypted data to other parties, without being forced to surrender their own private keys to perform decryption of that data. [0017] A part of the present invention addresses these Public Key encryption problems. First, users may freely exchange information by utilizing a new technology, semi-private keys. Semi-private keys are simply secondary public/private key pairs implemented in such a way as to appear to the user to be unique new key types which allow for distribution of information to users who do not possess their own public key, without having to reveal one's own private key. Semi-private keys allow users to share limited numbers of encrypted documents with other parties, while still ensuring that any data encrypted with their own public key remains secure. [0018] For purposes of this invention the main information bank (server) has high availability via standard Internet connectivity protocols. In one particular configuration, this server is responsible for storing all encrypted data files for each user, and also stores the user's public key and private key, in a secure form. [0019] Clueing may to be used to allow the proprietor or sender of confidential data to give access to another individual to that confidential data. The data may be transmitted by any wired or wireless electronic means including telephonically. In an embodiment instant or non-instant messaging of such devices may use clueing to allow such messages or access to electronic networks to be accomplished. The proprietor or sender through electronic mail or file transfer protocols, or telephonic to digital, or telephonic to person to digital means, may compose whatever material they wish encrypted. A proprietor or a sender may through single or combination applications establish a clue to allow the recipient to decrypt the material. A clue may be an answer requiring a question, completion of a map or drawing, a puzzle, a series of questions, known or partially revealed musical tunes or tones which may or may not require a musical response, trivia questions, an account number, mathematical or logical questions. Other possibly pre-arranged identifying information or clues that would be known to both parties and in fact may appear false or illogical but which are unlikely to be answered by an eavesdropping party may be applied. The degree of confidentiality desirable for the proprietor or sender to set is determinable in their own mind or from a myriad of clues that this mechanism can generate for them. One embodiment of the invention provides for election of clues and responses from a computerized generator to include statistical weights to the clue and response solution process. Once the clue is set and the data is encrypted, a message may be electronically sent to the recipient party or parties. They simply may receive a message with or without a direct link back to the client server, or an Internet server, a virtual private network or other similar networks or electronic mail or messaging systems holding the encrypted data or unencrypted data that an individual wishes to become encrypted. Once they successfully answer the apparent clues they are given access to only the data which the proprietor or have designated. Certain privileges for handling the data by the recipient may have been authorized or be authorized upon a request. The system may lead the recipient(s) directly to the proprietor or sender or may lead the recipient through a clued maze to get authority electronically determinable authority to download, edit, print or forward or otherwise enhance, alter or manipulate that data. The recipient may receive and respond to the electronic message using the same server electronic messaging system or any other non-identical electronic mail or access system. These may include, wired and or wireless systems, voice or digital system, or any other not yet described communication means, with or without other keying or identifying information. [0020] Encryption and decryption may be accommodated in one of many ways. One encryption methodology may entail the utilization of Java code running in the client browser to make use of the client processor to handle the encryption processing. In this example, the server returns the requested encrypted document to the client computer, along with the user's encrypted private key. Once the user has entered the correct key-phrase, a client-side Java engine decrypts the user's private key, then uses this private key to decrypt the data file. Likewise, an example implementation of the decryption process includes the server returning the users' public key to the client browser. This key is then used to encrypt the user-selected data file, and finally, the data file is uploaded to the server for indelible storage. [0021] To ensure data integrity and indelibility, a verification process may be used to indicate that the file was received correctly after upload/download. A one-way hash of the encrypted file may be passed along with the file at upload or download. This hash is then compared to a re-hash of the received file. If the two hash values match, there is a high probability that there were no file transmission errors. [0022] Once a user has downloaded and decrypted a file on any computer, that individual should ensure that information's security by erasing the file from any local disks. Most modern operating systems do not actually eliminate the file from the disk when the user requests that the file be deleted. Instead, the location of that file is simply removed from the disk's allocation table. This means that the file still exists on the disk in a decrypted form. With the proper software, virtually any user may easily recover file that has physical access to the computer. For this reason, the present invention includes facilities to ensure that files are actually destroyed when the user is finished using them, by overwriting the files with useless data. [0023] Normally, it is very difficult to positively and definitely identify a remote computer user. Without absolutely reliable identification, a digital signature provides little legal weight; anyone may claim another person's identity, establish a digital signature with that identify, and attempt to sign documents under this alias. Further, establishing positive user identification requires that trusted administrators actually meet the user and examine some form of government-issued identification. Clearly, digital signatures must be associated only to users who are known to the certificate authority, however, the requirement that the certificate authority actually visually confirm the user's identity is very burdensome. A more efficient solution is required for this problem. [0024] A fundamental part of the present invention involves the establishment of user trust levels to establish confirmed user identity, and to associate a digital signature with that trusted user. The user authentication system described herein allows for specific methods of establishing user trust and identification. These methods allow trusted institutions and information-provider partners to submit identity-verifying information to a user's personal vault. Once received, system administrators may examine this information and, if appropriate, increment the user's trust level. Once enough “trust points” are established, the user is established as “trusted” and her or his server-issued digital signature is considered valid and binding as it pertains and is associated with a rating system which provides concerned parties potential thresholds for rejection or acceptance of such authenticated transactions. In this way, for example, a user's identity may be remotely determined for the purpose of assigning a digital signature to that identity. [0025] A variety of information exchange and storage systems may be implemented using elements of the present invention. These systems will enable secure exchange and storage of information for a single user, groups of users, businesses, business partners, governments, and other institutions. Additionally, implementation of the present invention (in one of many possible forms) provides for the indelibility, availability and validity of information exchanged/stored. [0026] A second goal of the present invention through newly described herein unique software, hardware and methods of doing business is based on enabling digital electronic and physical distribution methods for mail, documents and goods. These methods, hardware and software may be used to enable deliveries the same day or some time thereafter of confidential documents and securely protected goods across substantial distances. The systems are to be prompted, organized and enabled through unique electronic software and hardware systems that will address improving the competency and efficiency of electronic and physical mailing systems. [0027] An embodiment of the invention is integrally dependent on the above disclosed inventions and is to enable confidential physical distribution of packages, mail or other goods and the messaging and communication means to further enhance it breadth and facility of application. Described are the electronic software, hardware, appliances and physical means to implement a hybrid of electronic and physical or solely electronic delivery of documents and goods or vouchers to goods, mailing and delivery systems. These systems are comprehensive in their capability and far reaching in their effect on daily business and personal life at local, national and international levels of application [0028] Described are functional physical hardware and remotely (including global international sites) both electronically and physically accessible specific hardware and software-enabled semi-private, private or public mail depots, kiosks and physical mailboxes. Their presence in key physical locations determines the impact of the distribution system in this invention. Described are depots having the most comprehensive capabilities for receiving and processing electronic media mail, messages, documents and goods for pickup or delivery. [0029] Depot functions may include contact of a recipient by phone or other electronic means indicated by the sender. Delivery of messages by personnel or electronic means, mail, or documents in the form of electronic disks, fax or physical imprinting upon printable surfaces may be personalized on a provided stationery and indelibly sealed when that is required. Hardware that perform these tasks are constructed as to be secure and highly efficient in confidential printing and sealing functions. So as not to create the need for physically handling non-sealed secure information included are means for shredding or otherwise destroying by over writing or chemically treating any jammed or poorly produced document packages prior to resetting or physically handling such physical systems and items therein. [0030] An embodiment of the invention uses secure systems of delivering disks with encrypted or non-encrypted messages. If encrypted messages are sent in electronic format they may be transferred to the addressee in automatically printed and confidentially sealed envelopes as disks or in other electronic formats or if required in their decrypted forms. If encrypted material is delivered a sender has the capability as described herein to deliver intelligible instructions to a recipient as to the means by which to decrypt such material. Couriers can do certification of receipt of the disk or physically printed mail. Disks may have written instructions or a message on the disk or in the envelope as to have to electronically handle the disk. [0031] Another embodiment of such an application would be to have a sender electronically forward material or physically report to a depot and there electronically by voice or other electronic mean compose an application. A disk-deposit or scan-in or use another electronically formatted deposit mechanism will allow such compositions. The application may be delivered to another Internet site with receipt capabilities or to a locale having another depot or related kiosk or public or private electronic mailbox. From said devices notification to a recipient would be made as per senders instructions possibly including fax, pager, telephone, electronic mail, or courier delivery of said notification or such good or package. The recipient may chose to receive the mail in any electronic form or physically by pick-up or delivery. [0032] Another function of the depot and the depot like devices may be electronic signature by any type of identity verification or by means described in this invention or by any other identification means that may exist. If required notarization may be facilitated by these same means. Recipient accessible electronic capabilities for return communication to the depot or kiosk, mailbox or vendor or sender may be applied to enhance further these above described applications, methods, hardware, appliances and software. [0033] Kiosks enabled by the systems described herein within publicly accessible areas for businesses and the public can serve some or all of the functions of the depots. Depots and kiosks may house the necessary software and hardware including Internet connectivity, printer-packager units, and uniquely designed electronic disk processing units. The depots and kiosks may serve as pick-up points for packages of goods there deposited or electronically created mail to be delivered to addresses in the area in confidentially printed and packaged physical form. Once notified individuals may pick-up their own packages or await delivery by proprietary agents or agencies contracted to perform those duties depending upon sender or vendor or recipient instructions or requests. [0034] Another embodiment is to have a kiosk placed physically in a distribution like mail deposit boxes on a street comers or other public areas for delivery of goods or documents. A kiosk could accept a package an electronic disk or a request for a fax or email to be sent to someone's electronic mail. It may o scan documents, faxes, emails, voice mails or other electronic content to physically create and seal the documents in an envelope for remote or local depot or kiosk for package pick-up or courier delivery. A depot may electronically forward them to a recipient with or without return of the original documents or electronic disks by physical means to the sender. [0035] In one embodiment the invention may also be used for remote from sender to a nearby to recipient vendor a request for a good or service package for a specified remote recipient. Depots and kiosks may serve as pick-up points for items brought there from surrounding vendors by physical means electronically coordinated by described herein electronic means. Pick-up of such goods can be arranged by a recipient through persons or businesses they may delegate to do so. Either a depot or kiosk may serve as a secure decryptor, printer, collator, packager and dispenser for packaged documents or goods. Vendors or their couriers may deposit goods for packaging and dispensing at a 24 hour, 7 day a week secure depot or kiosk. Messaging to and from a recipient, a vendor and a sender may be electronically accomplished by the secure communication means described on the invention. [0036] Electronic public or private mailbox hardware embodiments are described and enabled by the software disclosed in this invention may also perform certain or all functions of a depot in embodiments which are configured to emulate these functions. [0037] Another embodiment is of a physical electronic mailbox at a business office or home, which is capable of securely receiving, printing and enveloping or packaging electronically mailed documents or electronically forwarding them to another electronic or physical address documents. These may or may not be sent through described depot and kiosk systems. [0038] For addressing, transferring or distributing, electronically or physically, files such as legal documents, receipts, warranties, insurance policies, benefits packages, tax returns or other highly confidential information which are to be protected from alteration and are authenticated or packages to the likes of government agencies, professional experts, businesses, clients, or persons alone, through the encryption, hashing and clueing techniques described in this invention are secure the implement digital electronic, physical printing, packaging and distribution means to ensure confidential transfers and indelible documentation's of such transactions. Enabled are secure electronic and physical messaging, transfer, electronic and physical storage processes that may be controlled through voice mail systems, pagers, telephones and any electronic or physical communication means. These processes are to enable people or businesses or governmental entities to contact others through initially electronically composed requests by electronic voice transmissions, electronic or physically created document programs. Electronic messaging to electronic or to physical messaging means or through fax, scanner, telephone or any other electronic means may be applied. These processes can be downloaded and printed at a personal or business physical site or electronically accessible Internet or intranet type-sites designated to be or not to be handled by personnel or electronic mailbox printers, kiosks or depots. Non-secure communications may also take place within the described systems. [0039] Documents are enabled to be opened securely from any browser or can have relayed notification to a recipient by telegram or notification to contact Internet based services by voicemail to message machine, pager or telephone or by fax or by combinations of messaging techniques. [0040] Encrypted document files may be put onto a disposable or non-disposable digital disk or printed and delivered on the encrypted disk or in printed form. If on a disk the individual may go to an Internet site or other physical repository site to obtain or apply the authorized key to decipher the encryption. This process may use a clueing system. [0041] An embodiment of any of the transactions newly enabled by this invention includes the transmission electronically of authenticated indelible electronic receipts or warranties or other legal documentation pertinent to the transaction. These may include electronic payment, receipt, warranty and full transaction authentication and return though electronic and or physical means indelible recordings of such transactions. Business or personal receipts from the likes of hotels, train, cabs, restaurants and from merchandise vendors may be electronically relayed indelibly to what ever email or internet site chosen by the users of these and other purchase of goods or services by whatever payment means. Hardware or appliances that are physically mobile or fixed may facilitate these transactions. [0042] Another embodiment application of the invention is the aggregation of local merchants' in-stock items that can be made readily available at specified times for delivery or pick up. The software can obtain a vendor price or an asking price, which may or may not be countered with a buyer bid price. The distance from an individual buyer or recipient of goods and comparative pricing of identical or similar items in the vicinity or remotely located can be obtained. This is supported by software that informs the client where in the immediate vicinity that item is in stock and at what price. The client could enter a request and be linked to content and nearby inventory selections. Securely a sender to a vendor request for a good or service package for a specified recipient remote or nearby a sender can be made securely. A vendor is notified of a request for purchase and electronically responds with pick-up or delivery readiness information and payment mechanisms including electronic payment or cash on pick up or delivery. [0043] In another embodiment a remote sender may electronically go to an Internet site enabled by the invention remote from sender but nearby recipient vendor of good or services. There can be sent a message by a sender or vendor to a recipient to accept or reject a service, pick up a package located at a vendor or one to be delivered to a local depot or kiosk or personal physical or electronically capable physical mailbox. A message or physical package accessible by a clued encryption or other means of electronic verification may be used to enhance the confidentiality and security of the process. [0044] To facilitate the above descriptions depots in public traffic areas or kiosks placed strategically for instance as comer kiosks like conventional mail boxes could be pickup sites for deliveries in that immediate geography by the public themselves or couriers. Packages or documents can to be taken to a depot or in the latter case electronically scanned, transferred or faxed. Payment could be by electronic cash transfer means such as cash credit cards or smart cards directly to the vending apparatus or to authorized personnel. People could electronically shop who do not have computers from depots in malls at kiosks or from a remote home or office based physical electronic mail box devices, computers or Internet capable appliances. [0045] In all embodiments of the invention the software and where applicable hardware and combinations thereof may reside on client and server computer hardware or solely on client computer hardware or solely on server computer hardware. Appliances that function in limited ways like computers may be substituted for client or server hardware. Combination networks of servers or servers and clients or client networks may carry or relate to one another wherein software may reside in any combination of physical hardware and appliances. BRIEF DESCRIPTION OF THE DRAWINGS [0046] [0046]FIG. 1( a ) is an overall system architecture of one embodiment of client side elements of the present invention. [0047] [0047]FIG. 1( b ) is an overall system architecture of one embodiment of server side elements of the present invention. [0048] [0048]FIG. 2 is a flow chart illustrating one embodiment of a registration process of the present invention. [0049] [0049]FIG. 3 is a flow chart illustrating one embodiment of an authentication process of the present invention. [0050] [0050]FIG. 4( a ) is a flow chart illustrating one embodiment of a private key encryption process of the present invention. [0051] [0051]FIG. 4( b ) is a flow chart illustrating one embodiment of a private key decryption process of the present invention. [0052] [0052]FIG. 4( c ) is a flow chart illustrating one embodiment of a file encryption and upload process. [0053] [0053]FIG. 5 is a flow chart illustrating one embodiment of a client to recipient confidential mailing and transaction process. DETAILED DESCRIPTION [0054] It is often necessary to transfer or store documents in such a way that they are physically safe (archived), indelible, and readable only by authorized third parties. Further, a computer system enabling these capabilities should be easy to use, and should be based upon technologies already well understood by the user community to allow for widespread use. The present invention addresses this problem by describing a computing system which enables users to indelibly and reliably store and retrieve files in an encrypted state on a remote storage media using a web browser to perform the encryption, decryption, and transfer operations. The web browser-based application may appear to the user to be a web-based file archiving tool, or may appear to be a web-based email tool. Futher, the encryption/decryption functionality may be enabled using either symmetric or asymmetric algorithms. The implementation described herein utilizes mainly asymmetric cryptographic algorithms. However, symmetric cryptographic algorithms may be substituted for much of the asymmetric algorithms, although implementation of only symmetric algorithms results in a loss of capability for the invention. This is because asymmetric algorithms are required to enable digital signatures, which form a fundamental part of the fully functional system. Thus, those skilled in the art may readily determine where either asymmetric or symmetric algorithms will suffice, and where asymmetric-only algorithms are required. [0055] Referring to FIG. 1, a file 30 is located on a client computer 11 . It is desired to place the file 30 , in an encrypted state on a data server 13 . The client 11 and the server 13 may be physically separated by any distance, and need infrastructure in place such as a dialup connection 21 or an Internet protocol connection 22 , such that they may establish a communication channel 20 . The client 11 initiates communication with the web server 15 using a web browser 5 . The web server 15 communicates with the data storage unit 12 and the data server 13 , as well as the key server 14 . The data server 13 , key server 14 , and web server 15 are software server applications that may run on one or more computing platforms. They needn't run on separate computer platforms, although in the preferred embodiment system performance and security may be enhanced if they are run on separate computer platforms. The web server 15 may communicate directly with the data storage unit 12 , or indirectly with the data storage unit 12 via the data server 13 . The only required server module is the web server; key server and data server functionality may be integrated directly with the web server, or may be implemented as stand-alone server modules. Similarly, the logical structure for data, key, and other information storage on the servers may be take on any number of forms well known to those skilled in the art. [0056] To establish an account with the system, a user is required to follow the registration process 100 as illustrated in FIG. 2. The client 11 establishes a connection to the web server 15 using standard HTTP, and requests 102 the registration page from the server. The web server responds 104 in the standard fashion, sending the web registration form back to the client 11 , which then displays the form to the user. The user then enters at least the minimum required information, and uses the client 11 to submit 106 that information to the web server 15 , utilizing a Secure Socket Layer (SSL) to ensure confidentiality of the submitted information. The minimum required information varies with different embodiments of the system, and with different uses of the same embodiment of the system. It is expected that, with most embodiments, the user will be required to submit (or will be assigned) at least a username 41 , password 42 , and keyphrase 43 . [0057] Referring to FIG. 3, the username 41 , password 42 , and keyphrase 43 may, depending upon the embodiment of the system, be selected by the user or by one of the servers. The utility of the username 41 and password 42 is to allow the user access to the system. By sending 140 a username 41 and password 42 to the system via a web form, or by any number of authentication protocols that are commonly known to those skilled in the art, the system may determine a user's rights to utilize the system and to access various system functions. In the preferred embodiment, the client 11 sends the username and password to the web server 15 via a web form 142 . The web server performs a database lookup against the submitted username and password 144 (Note that to provide higher security, the database may actually store a cleartext username and an encrypted password; thus to perform a database lookup the username and encrypted password would be used). If a match is found the web server uses the database to determine the client's access privileges, and dynamically builds the user's home page which allows these privileges 147 . If no match exists in the database, a web page is returned to the client indicating that logon failed 148 . To prevent unauthorized logon to the system by hackers submitting a large number of usernames and passwords, the web server may include in process 140 a script which blocks, for a specified time period, logon attempts for usernames which have submitted incorrect passwords several times in a row. [0058] As part of the registration process, a code component will generate a public-private keypair. This code component may reside on the server or on the client, depending upon the specific embodiment. The public key will be transferred for storage in the Key Storage Unit 16 . The private key will be encrypted using the keyphrase (as described below) and then transferred for storage in the Key Storage Unit 16 . Depending upon the implementation, the keyphrase may or may not be stored on one of the servers. Storing the keyphrase may be useful in case a user forgets his keyphrase; without it, any data encrypted is useless and unrecoverable. However, storage of the keyphrase anywhere (except in the user's mind) may enable a third party to decrypt the user's data. [0059] Referring to FIGS. 4 ( a ) and 4 ( b ), a keyphrase 43 is used to convert 150 a private key 10 into an encrypted private key 9 , and to convert 160 an encrypted private key 9 into a private key 10 . [0060] The private key may be converted into an encrypted private key in any number of ways commonly known to those skilled in the art. In the preferred embodiment, the keyphrase is used as input to a fixed-length hash algorithm 154 . The output of the hash algorithm is always a sequence of bits of a predetermined length, the contents of which vary depending upon the keyphrase that was used as input to the algorithm. The hash of the keyphrase may then be used as the key for a symmetric encrypt-decrypt algorithm 156 . There are many symmetric algorithms that are suitable for this function. In this way, the cleartext private key is converted into an encrypted private key 158 , with the hash of the keyphrase serving as the key to the encrypt-decrypt process. [0061] The encrypted private key may be converted into a cleartext private key in any number of ways commonly known to those skilled in the art. In the preferred embodiment, the keyphrase is used as input to a fixed-length hash algorithm 164 . The output of the hash algorithm is always a sequence of bits of a predetermined length, the contents of which vary depending upon the keyphrase that was used as input to the algorithm. The hash of the keyphrase may then be used as the key for a symmetric encrypt-decrypt algorithm 166 . In this way, the encrypted private key is converted into a cleartext private key 168 , with the hash of the keyphrase serving as the key to the encrypt-decrypt process. [0062] Once the user is authenticated he is presented with a variety of tasks he can accomplish using the system. Most of these tasks utilize code components. The main component is the User Application 19 . This application displays a Graphical User Interface (GUI) which provides point-and-click functionality within the web browser 5 . Other components include: the Public Key Crypto Engine 7 , the Symmetric Key Crypto Engine 4 , and the Hash Engine 3 . These engines may exist as physically distinct components, or may be embedded within the same code module. These engines may be implemented in a wide variety of ways. The most important aspects of these applications are not the particular implementation, but the contained functionality. For instance, the Crypto Engines may use one or more of many possible encryption algorithms; the key feature is the crytography that is enabled, not the particular algorithm used. Likewise, the Graphical User Interface of the User Application may be designed to look significantly different between two implementations; the key feature is that this component allows graphical access to the functionality contained in that and in other engines. [0063] As illustrated in FIG. 4( c ), after authentication 140 , files may be identified, encrypted, and uploaded to the dataserver via process 170 . The user first indicates his desire to upload a document by clicking a link on his user home page. components are then downloaded to a browser to enable file selection, encryption, and uploading. Using the User Application 19 , the user may “browse” his local directory structure to identify the file of interest. Once the user has selected a file, the succeeding steps of the process may be accomplished automatically, or they may be accomplished under the user's direct command. In the preferred embodiment, all processes occur automatically once the user has selected the file of interest. Next, the user's Public Key 8 and the cleartext Document 30 are input to the Public Key Crypto Engine 7 ; the result of this operation is the Encrypted Document 32 . The Encrypted Document 32 is then passed through the Hash Engine to produce a Hash of the Document 34 . Both the Document Hash 34 and the Encrypted Document 32 are then stored to the user's private data area on the Data Server 13 . [0064] Once authenticated 140 , the user may choose to view the contents of his private storage area on the data storage unit 12 by selecting the appropriate link on his user home page. If the user selects an encrypted file for downloading to his local system, his encrypted private key 9 , the Hash 34 of the encrypted document, and the encrypted document 32 are downloaded to his local machine. The user inputs 51 his keyphrase 43 into the User Application 19 , which completes the remaining steps automatically and without further user intervention (note that the User Application may be implemented in such a way to allow the user to control various intermediate steps of the decryption process). The keyphrase 43 is input to the Hash Engine 3 , which produces a Hashed Keyphrase 40 . The Hashed Keyphrase 40 is input into the Symmetric Crypto Engine 4 , along with the Encrypted Private Key 9 . If the keyphrase was correctly input, the result of this operation is the Cleartext Private Key 10 . The Encrypted Document 32 is then passed through the Hash Engine to produce a Hash of the Retrieved Encrypted Document 35 . The Public Key Crypto Engine compares the Hash of the Retrieved Encrypted Document 35 to the Hash of the Original Encrypted Document 34 . If these are identical, it can be assumed that a third party has not altered the Encrypted Document 32 either accidentally through the uploading/downloading process or intentionally. The Cleartext Private Key 10 and the Retrieved Encrypted Document are finally passed through the Public Key Crypto Engine 7 to produce the Decrypted Document 39 . [0065] Possible failure modes of the above process include incorrect input of the keyphrase and non-matching Hashes 34 and 35 . If the user incorrectly input the keyphrase, the process will continue to completion, however the result will not be the Decrypted Document 39 , but instead will result in unintelligible characters. If the Hashes 34 and 35 are found to not match, the Public Key Crypto Engine will alert the user, via the User Application, that an error has occurred. [0066] Once authenticated 140 , the user may then choose to create a semiprivate key to associate with any particular document. The association of a semiprivate key to a document is fundamental to allowing the file to be shared with others while remaining encrypted on the server. Note that there are a tremendous number of ways to design the process of semiprivate key generation and assignment. Once again, the ability to generate the semiprivate key and assign it to a document is at the fundamental essence of the invention. In the preferred embodiment, the Public Key Crypto Engine 7 will generate the semiprivate keys and pass them to the Web server 15 for placement into the Key Storage Unit 16 . Note that it is possible to implement key generation on the servers rather than on the clients. [0067] Once the user, has selected a link on his home page to create a semiprivate key, the User Application Engine 19 and Public Key Crypto Engine 7 are downloaded to his machine and User Application Engine 19 is displayed within his browser. The user then instructs the Public Key Crypto Engine 7 to generate a new semi-private key. Depending upon the implementation, the creation and management of semi-private keys may be more or less automatic. At one extreme, the semi-private keys may be treated as one-time-use keys. In this case, the key would be automatically generated for use with a particular document. The public and private keys are produced, the document is encrypted with the public key, and then the public key is discarded. The private key is encrypted with a chosen keyphrase, then the keyphrase is discarded and the encrypted private key is placed into the key storage unit. At the other extreme, the semi-private keys may be treated as “just another set of keys.” In this case, the user would request that a new keypair is generated, then a user may name that key, and to distinguish it from other semi-private keys he has created. Depending upon the implementation, the user may be allowed to select key characteristics, such as key type and key length, or the user may have no choice regarding these key characteristics. After encryption of the private key using the keyphrase, the keyphrase is discarded, and the public and private keys are stored in the key storage unit for later use. [0068] In many implementations, it may be desirable to allow sophisticated users to manage their own semiprivate keys, in which case, the semiprivate keys are just considered additional keypairs to manage. In other cases, it may be desirable to “hide” the real implementation of semiprivate keys to make them appear to the user to be a new kind of key. In this implementation, the user may simply select a document for shared distribution to a third party, and let the engine automatically create the keys, encrypt the document, and discard the public key automatically. The utility of this invention is that the users may simply and easily create new keys at any time, and may use those keys to encrypt data for individuals who do not have access to encryption technology. In this way, users of the invention may implement unilateral encryption, and make secure sharing of important documents simple “for the masses.” Today, to use encryption for document sharing two parties are forced to agree in advance on an encryption software package, buy and install the package, generate and exchange keys, then encrypt and exchange documents. This is a serious impediment to the widespread use of encryption technology. Using the elements of the invention, a user may generate a semiprivate key, encrypt a document, and place that document on a Web site, along with the encrypted private key required to decrypt the document. The only remaining difficulty is to pass the keyphrase to the third party to allow the decryption process to occur. That difficulty is addressed in the next section. [0069] In some circumstances, it may be cumbersome to call or email the third party to tell him what the keyphrase is for a particular encrypted document. Further, these key exchange techniques may prove insecure, revealing the keyphrase to interested parties capable of monitoring standard communications channels. Further, to enable “encryption for the masses,” the technology must be simple to use, and must not require specialized knowledge on the part of the user. To facilitate this, the invention utilizes “clueing” to enable the “silent” and automatic exchange of keyphrases. [0070] Once the user is required to enter a keyphrase for a new private key, the user may also be prompted to enter a cluephrase, the answer to the cluephrase being the keyphrase. For instance, the user may enter “ginger” for a keyphrase, and the cluephrase “what is my dog's name?” The security of the key exchange then depends upon the user choosing a keyphrase and cluephrase such that it is unreasonable that any other party might guess the keyphrase by knowing the cluephrase. [0071] To continue, we assume that the user has selected to produce a semiprivate key for the encryption of a particular document. The user has entered a keyphrase and cluephrase for the semiprivate key. The public component of the semiprivate key is used to encrypt the document, and the encrypted document is then stored in the user's private data area. The user has also entered the email addresses of all users who should be allowed to view the encrypted document. Once the process is complete, emails may be sent to all the receiving parties, informing them to go to a particular Web site to retrieve an encrypted document. Thus, in the simplest user implementation, the user simply selects a document to share, selects a keyphrase and cluephrase, and enters the receiving parties' email addresses to allow secure document exchange with those parties. The process for these receiving parties to view the document is described in the next section. [0072] Once a receiving party is notified via email that there is an encrypted document waiting for him at a particular Web site, the receiving party uses his web browser 5 to view that Web site. Code components (user application, crypto engines, etc) may, depending upon the implementation, be downloaded to the receiving party's browser. The receiving party then selects the option to view a document, and enters the sending party's username, and his own email address. A database lookup then finds any documents stored on the server which are to be made available for viewing by the owner of the input email address, from the username input. The user may then select to view the document that is shown. The receiving party then is shown the cluephrase, and is asked to respond with the keyphrase (the answer to the cluephrase). Since the keyphrase may not have been stored upon the servers (depending upon the implementation), it may not be possible to verify that the correct keyphrase has been entered. Instead the encrypted private component of the semiprivate key is downloaded to the browser, along with the encrypted document 32 , and the hash of the encrypted document 34 . The keyphrase entered by the receiving party is passed to the one-way fixed-length hash engine 3 , which produces a hash of the keyphrase 40 . The hash of the keyphrase 40 is then passed to the Symmetric Crypto Engine 4 , along with the encrypted private key 9 . If the correct keyphrase was originally entered, then the result of this operation is the correct decrypted cleartext private key 10 . If the incorrect keyphrase was entered, the result is a bit string of the correct key length, but not corresponding to the key that will properly decrypt the document. The encrypted document 32 is passed through the hash engine 3 to produce a new hash 35 of the encrypted document. The Public Key Crypto Engine compares the new hash 35 and the downloaded hash 34 of the encrypted document. If the hashes do not match, an error occurred, most likely in transmission, and the user is alerted of the error condition. If the hashes match, the decryption process continues. The encrypted document 32 and the cleartext private key 10 are passed to the Public Key Crypto Engine, which uses the key to produce the decrypted document 39 , which is then placed on the receiving party's local data storage unit 17 . If the incorrect keyphrase was originally entered by the receiving party, the cleartext key 10 used by the Public Key Crypto Engine will be incorrect, and will result in a “decrypted document” which will be unreadable gibberish. [0073] The invention described above has obvious benefits over standard encryption processes, in terms of ease of use and no requirements for user-to-user “handshaking” before exchange of documents. Because all software, keys, and documents are stored and retrieved from internet/intranet servers, the only thing a user needs is a computer with a modern browser and a connection to the internet or his own intranet. The remainder of the system is downloaded dynamically and seamlessly from the servers. While it is possible for a user of the system to distribute encrypted documents to persons who have never used the system, it is also possible for persons who have never used the system to send encrypted documents to particular system users. This process is described in the following section. [0074] Suppose a user would like to receive an encrypted financial analysis from his accountant, but doesn't want to deal with cumbersome encryption packages. Further, the accountant doesn't want to install several encryption packages on his machine to accommodate all his clients who use different packages. Instead, the user may simply tell his accountant to send go to a particular Web site and upload the encrypted document to him. The accountant then uses his browser 5 to view the Web site. He selects an option to upload a document to a system user. Code components are downloaded to his browser, which enable subsequent action. He enters his client's username (or email address) and selects the document to be uploaded. A database lookup on the username (or email address) is used to locate the client's primary Public Key 8 , which is stored on the key server 14 . The public key 8 is downloaded to the accountant's computer, along with the Public Key Crypto Engine 7 . The Public Key Crypto Engine 7 uses the Public Key 8 to encrypt the cleartext document 30 , to produce an encrypted document 32 . Additionally, the encrypted document 32 is passed to the hash engine 3 to produce a hash 34 of the encrypted document. The hash 34 of the encrypted document and the encrypted document 32 are then uploaded to the user's private data area on the servers. Additionally, the user may be automatically notified via email that a new encrypted document is waiting to be viewed. In this way, users who do not have their own public/private keys, and have no knowledge of other users' public and private keys, may simply send encrypted documents. [0075] Once a user is notified via email that there is an encrypted document waiting for him, he uses his web browser 5 to go to the Web site. Code components (user application, crypto engines, etc) may, depending upon the implementation, be downloaded to the user's browser. The user may then select to view uploaded documents, and may be shown all documents waiting to be viewed. The users may select an encrypted document 32 to view. The private key is downloaded to the browser, along with the encrypted document 32 , and the hash of the encrypted document 34 . The user enters his keyphrase, which is passed to the one-way fixed-length hash engine 3 , which produces a hash of the keyphrase 40 . The hash of the keyphrase 40 is then passed to the Symmetric Crypto Engine 4 , along with the encrypted private key 9 . If the correct keyphrase was originally entered, then the result of this operation is the correct decrypted cleartext private key 10 . If the incorrect keyphrase was entered, the result is a bit string of the correct key length, but not corresponding to the key that will properly decrypt the document. The encrypted document 32 is passed through the hash engine 3 to produce a new hash 35 of the encrypted document. The [0076] Public Key Crypto Engine compares the new hash 35 and the downloaded hash 34 of the encrypted document. If the hashes do not match, an error occurred, most likely in transmission, and the user is alerted of the error condition. If the hashes match, the decryption process continues. The encrypted document 32 and the cleartext private key 10 are passed to the Public Key Crypto Engine, which uses the key to produce the decrypted document 39 , which is then placed on the user's local data storage unit 17 . If the incorrect keyphrase was originally entered by the receiving party, the cleartext key 10 used by the Public Key Crypto Engine will be incorrect, and will result in a “decrypted document” which will be unreadable gibberish. In this way, the user may directly download encrypted documents sent to him by persons who are not bona fide system users. [0077] [0077]FIG. 5 depicts the systems for creation of documents that are to be securely distributed and a parallel system which goes then into a final common pathway series distribution system similar to the document distribution system. FIG. 5 depicts creation of documents or files using standard software like linux, html, and xml. FIG. 5 then uses the above described processes to encrypt, authenticate, hash, electronically sign and electronically pay for services or goods that may be requested electronically. That information is passed to an intranet server 503 to be relayed to an Internet server 504 or it may go directly from the client to the Internet 504 . The software that allows steps 500 and 501 may reside on a client computer or the client may obtain these capabilities from an intranet server 503 or an Internet server 504 . If document or other mailings are requested the transfer electronically be relayed in its secure form to the secure kiosk computer 506 . Similarly the client may be requesting a purchase order as shown in step 502 . The request may then be relayed through the internet as above shown sequentially as steps 502 to 501 to 503 to 504 or directly to 504 leading to step 505 . The requester may obtain information about nearby or remote vendors that may have an item or a similar item immediately available or at some determinable time available. In step 505 options are available for communication between a requester and a vendor. Payment, pick-up or delivery times along with transaction related secure documents might be securely relayed between steps 502 and 505 . A requester may direct a delivery to a secure kiosk by entering that system at any point but here depicted as entering at steps 506 or 512 . [0078] The secure kiosk functions for decryption of documents are depicted in step 507 . Materials are further protected in step 508 where printing or document overwriting or shredding or chemical destruction may occur if the printer jams and repairs are needed or a request from the originator of the document is relayed. The documents may then be collated at 509 and packaged at 510 . Mailed documents or packages may enter the system then at 512 . A recipient may pick-up the package at 513 or is informed that it is ready through the mechanisms depicted in 514 . Communication from the kiosk or any other computer or through voice mail instructions may return to a sender or vendor if another request or return message is desired. The recipient may though the mechanism in 514 also indicate what pick-up options are desired as for courier delivery in 516 or to be sent on from the kiosk or depot by governmental (United States or any other country public or private physical mail carrier services). Personal pick-up and alternative delayed delivery options are depicted in steps 518 and 519 . [0079] The entirety of the system depicted has multiple capabilities for reversing the messages or requests through open but secure messaging process as shown in the flow chart. [0080] The invention described above enables a variety of encryption-enabled resources. For instance, remotely-stored, encrypted files are enabled, along with encrypted messaging. One potential drawback to the encryption-enabled email described above is that the email recipient is required to access the email via a website. The invention includes an additional feature that allows encrypted email to be sent directly to the intended recipient, so that the recipient is not required to go to a website to retrieve the email document. This addition to the invention is described below. [0081] Email sent directly (in an encrypted state) to a user may be implemented in a platform independent manner by making use of the Java Virtual Machine which is included with every modem web browser, and will be available on the recipient's machine. The sender may directly send encrypted email by selecting that option from his user home page. Components are then downloaded to the sender's browser which enable the sender to enter the email address, text message, attachments, keyphrase, and cluephrase. Since the email will be sent directly to the recipient, the public key infrastructure on the servers will not play a role in the encryption/decryption process. Instead, the Symmetric Crypto Engine, which contains symmetric crypto algorithms, will be used to encrypt the message and attachments. The encryption process begins when the Hash Engine produces a fixed-length hash of the keyphrase to be used as a symmetric encryption key. The text message and attachments are individually encrypted using the hashed keyphrase and the Symmetric Crypto Engine. The encrypted message and documents are then concatenated to form a byte-stream data message. At the beginning of this byte-stream data message, values reflecting characteristics of the encrypted text message and the encrypted documents are concatenated. Java code is then concatenated to the front of the byte-stream data message, to form the complete message. This Java Code implements a self-contained decryption engine which is capable of extracting the byte-stream data message, receiving a keyphrase, and carrying out all steps required to decrypt and display the message. The step of concatenating the Java Code to the byte-stream data message may occur either on the sender's machine, or on one of the servers after the byte-stream data message is uploaded. In the end, one of the servers will possess a complete message (consisting of Java Code, message characteristics, encrypted text message, and the encrypted documents), a recipient's email address, and a cluephrase. This is packaged into a standard email, which contains standardized text indicating that this is an encrypted message, along with the text of the cluephrase. The complete message is sent as an attachment to the email to the recipient. Once received, the recipient “opens” the attachment. This results in the recipient's Java Virtual Machine being loaded, which begins to read the complete message. A user interface is displayed which allows the recipient to enter the keyphrase. The Java Code (which contains the decryption engine as well as the hash engine) then hashes the keyphrase and uses that hash to decrypt the accompanying byte-stream data message. Finally, the user interface allows the recipient to save/display the decrypted message text, and save the decrypted attached documents.

The present invention relates to methods for secure distribution of documents over electronic networks. The method may be implemented over public private and/or semi-private electronic networks, including computer networks, intranets, the Internet or combinations thereof. The method includes novel clueing and encryption mechanisms for secure transmission of documents and other electronic data. The method may further include steps for recording the transmitted document in a tangible medium and secure delivery of the document to an intended recipient.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a United States National Phase Application of International Application PCT/EP2015/080013 filed Dec. 16, 2015, and claims the benefit of priority under 35 U.S.C. §119 of European Application 14199695.9 filed Dec. 22, 2014 the entire contents of which are incorporated herein by reference. FIELD OF THE INVENTION [0002] The invention relates to a hydraulic system. BACKGROUND OF THE INVENTION [0003] Hydraulic systems, in particular hydraulic circulation systems are known for example in the form of heating installations and/or air-conditioning installations, in which a fluid heat transfer medium, for example water, is delivered in a circuit. The hydraulic systems for this, as a rule comprise at least one circulation pump assembly which circulates the fluid in the system. [0004] It is also known, to be able to arrange switch devices such as valves for example, in such hydraulic systems. Switch-over valves which permit the switch-over between two hydraulic circuits or two heating circuits are often to be found in heating installations for example. Thus, for example in a heating installation, a heated heat transfer medium can either be delivered through a room heating circuit or a heat exchanger for heating service water, depending on the switch position of such a valve. The switch-over valves which are necessary for this as a rule are electrically driven and activated. This means that electrical drives with necessary electrical connections are required. SUMMARY OF THE INVENTION [0005] It is an object of the present invention, to simplify a hydraulic system in a manner such that the number of necessary electrically actuated switch devices in the system can be reduced. [0006] The hydraulic system according to the invention comprises at least one circulation pump assembly and at least one hydraulic circuit which is connected to this circulation pump assembly. Thereby, the hydraulic circuit is connected to the circulation pump assembly such that the circulation pump assembly circulates a fluid, such as water for example, in the hydraulic circuit. The hydraulic circuit thereby for example can be a heating installation or cooling installation, in which a fluid heat transfer medium, for example water, is delivered in the circuit. With regard to the circulation pump assembly, it is preferably the case of an electromotorically driven circulation pump assembly, e.g. a centrifugal pump assembly, in particular with a wet-running electric drive motor. [0007] The circulation pump assembly according to the invention comprises a speed controller which permits the circulation pump assembly to be operated with at least two different speeds. Preferably, the circulation pump assembly can be set in its speed over a large range via the speed controller, i.e. the speed can be changed over a larger speed range in several steps or in an infinite manner. [0008] Apart from the circulation pump assembly, according to the invention, at least one mechanical switch device is arranged in the hydraulic circuit and this switch device is subjected to the pressure of the fluid located in the hydraulic circuit or of the liquid located in the hydraulic circuit. The mechanical switch device can be moved into at least two different switch positions, i.e. at least into a first and into a second switch position. [0009] According to the invention, one envisages making do without a separate, for example electric drive for the mechanical switch device, and instead, effecting the switch-over between the switch positions solely by way of the liquid or fluid which is located in the hydraulic circuit. This means that according to the invention, a force transmission is effected from the circulation pump assembly onto the mechanical switch device via the fluid located in the hydraulic circuit. This means that the at least one mechanical switch device is hydraulically coupled, preferably exclusively hydraulically coupled, to the circulation pump assembly via the fluid in the hydraulic circuit. Thereby, preferably no further mechanical coupling is provided between the circulation pump assembly and the switch device. In particular, no coupling is provided between the rotor or the impeller of the circulation pump assembly and the switch device via a mechanical engagement of these components. This means that preferably an exclusively hydraulic coupling via the fluid is envisaged. [0010] The hydraulic coupling, via the speed controller, permits the adaption of the speed of the circulation pump assembly, i.e. permits the change of the speed given the same rotation direction, and moreover the actuation of the switch device, via the speed controller. For this, a suitable hydraulic force is produced via the speed adaptation of the circulation pump assembly via the at least one hydraulic circuit, and this force via the hydraulic circuit acts upon the switch device and causes the movement of the switch device. This one can make do without a separate drive of the switch device. The switch device in contrast can be moved preferably solely by hydraulic forces which are transmitted via the hydraulic circuit. These hydraulic forces can be produced in a targeted manner by way of speed adaptation or by way of the control of the speed of the circulation pump assembly by the speed controller. Here, the rotation direction of the circulation pump assembly is retained. Preferably, these are speed changes or speed adaptations which do not occur on normal operation of the hydraulic system, for example of a heating installation, or do not compromise this normal operation. The normal operation of the hydraulic system is thus not compromised by the switching of the mechanical switch device. [0011] The mechanical switch device is preferably designed in a manner such that it reacts to pressure changes due to a speed change of the circulation pump assembly, in a manner such that the mechanical switch device is movable in dependence on the pressure or a change of the pressure, selectively into one of the switch positions. Thus for example it is possible for the switch device to be designed such that it moves into one of the two switch positions only on reaching a certain limit pressure. Thus one can succeed in the switch device e.g. being moved into a second switch position by way of increasing the pressure in the hydraulic system to or beyond this limit pressure. Thereby, the hydraulic system is preferably designed such that this limit pressure is not reached in the first switch position with normal operation, so that this first switch position can be safely retained in this operating condition. In a heating system for example, it is possible for service water heating to produce a higher pressure than is necessary for normal operation of the heating installation for heating a building. Thus the switch device, by way of increasing the pressure beyond a predefined limit value, can be moved into the second switch position which for example can be used to heat service water via the installation, as it is described hereinafter. [0012] Alternatively, it is also possible not to design the switch device with regard to its switching function in a manner dependent on the absolute value of the pressure, but to design it such that it reacts to certain changes of the pressure, so that a switch-over from one switch position into the other can be achieved by way of targeted pressure changes. Thus in particular the switch device with regard to its switch function can be dependent on the speed of the pressure change so that it is designed for example such that with a rapid pressure change, it moves into a first switch position and with a slow pressure change into a second switch position. [0013] According to the invention, one preferably envisages designing the switch device in a manner such that it reacts to differences in the course of a pressure build-up or pressure reduction of the fluid, given a speed change of the circulation pump assembly, in order to initiate a movement between the two different switch positions. This means that according to the invention, a combination of a circulation pump assembly and a mechanical switch device is provided, which utilizes a variability of the circulation pump assembly which has not been used until now, for moving the switch device. Whereas the speed of the circulation pump assembly which is to be reached on operation as a rule is determined and set by the desired flow or differential pressure in the hydraulic circuit, the running-up behavior and the braking behavior of the circulation pump assembly in previous hydraulic systems, such as heating systems, as a rule has no influence on the actual operation of the system. Inasmuch as this is concerned, one preferably envisages the starting-up behavior or braking behavior or the type or the course of a speed change of the circulation pump assembly, by way of variation, being used to move the switch device into a desired switch position via the hydraulic coupling. This means that the circulation pump assembly and the switch device are preferably designed such that the switch device is not moved into a desired switch position in dependence on the absolute pressure or end pressure which is to be achieved and/or on the end flow which is to be achieved, in the hydraulic circuit, but solely in dependence on the course of a pressure build-up or of a pressure reduction in the hydraulic circuit in dependence of a course of a speed change of the circulation pump assembly. For this, the switch device is preferably designed such that with a speed change (i.e. a speed increase or speed reduction) of the circulation pump assembly with a first course of the pressure build-up, it moves into a first switch position, and with a speed change of the circulation pump assembly with a second course of the pressure build-up which is different to this first course it moves into a second switch position. The drive of the circulation pump assembly is preferably activated via the speed controller in a different manner, in order to achieve the different courses of the pressure build-up. This means that no separate electric drive device for the switch device is necessary, and the single electrical component to be electrically activated is preferably the drive motor of the at least one circulation pump assembly. This drive motor, by way of a suitable setting of the course of a speed change via the speed controller, from which a different course of the pressure build-up or pressure reduction results, can simultaneously be used to actuate the switch device which is designed in a correspondingly matching manner. [0014] Particularly preferably, the mechanical switch device is designed in a self-holding manner, such that it remains in the assumed switch position, up to a predefined speed or speed change of the circulation pump assembly. Thus the circulation pump assembly after reaching the desired switch position in particular can be controlled or regulated in the conventional manner, e.g. in order to set a desired differential pressure via the circulation pump assembly and/or the desired flow in the hydraulic circuit. This regulation (closed-loop control) then has no influence at all on the selected switch position. This means that the pump assembly on operation is self-holding up to a defined speed or speed change which is to effect a change of the switch position of the switch device. This speed change is preferably a speed change in the form of an acceleration, which is to say an increase of the speed from standstill of the pump assembly or departing from a basis speed. Alternatively, the speed change however can also be a speed reduction. The circulation pump assembly and the switch device are particularly preferably designed such that the speed of the circulation pump assembly is firstly reduced to such a basis speed or until standstill and then departing from the standstill or the basis speed a desired course of the speed increase and thus a correspondingly desired course of the pressure build-up is selected which is suitable for moving the switch device into a desired one of the possible switch positions or holding it in a desired switch position, for switching between the first and the second switch position of the switch device. [0015] The speed controller is preferably designed in a manner such that with the help of this or by way of it, at least two different speed courses of the circulation pump assembly can be set, wherein the speed controller is further preferably designed in a manner such that the circulation pump assembly permits speed changes with at least two different acceleration courses. Thus the circulation pump assembly for example can be a circulation pump assembly with a drive motor which is closed-loop controlled in its speed, in particular with the help of a frequency converter. The speed controller thus can preferably be designed such that it can infinitely vary the speed. Alternatively, the speed controller however can also be designed such that it can set at least two different predefined speeds or several predefined speeds. The speed courses in particular can be ramps on starting up or braking the circulation pump assembly, which are preferably set differently steeply by the speed controller, wherein the switch device is then preferably designed such that with a slow speed change, it assumes a first switch position and with a rapid speed change with a steeper ramp, it assumes a second switch position. The slow speed change effects a slow pressure build-up or pressure reduction in the hydraulic circuit, and in contrast the rapid speed change effects a rapid pressure build-up or pressure reduction in the hydraulic circuit. The differently quick pressure build-up or pressure reduction is transferred onto the switch device which is designed such that it can react to the speed of the pressure build-up or reduction. The pressure build-up thereby can be effected in a continuous or constant manner, in particular with a speed increase. Alternatively, a stepwise speed change and thus a stepwise change, in particular increase of the pressure is possible as a speed course. Thereby, a slow pressure increase or pressure reduction for example can be designed such that it is effected in several steps or several stages, whereas the rapid pressure increase or reduction is effected in a direct manner. Pauses which are longer than with the rapid pressure increase or reduction could also be taken between the stages or steps for the slower pressure increase. It is to be understood that preferably the same end pressure as an operating pressure in the hydraulic circuit is always achieved with the different courses of the pressure build-up or pressure reduction, so that after actuating the switch device, the operation subsequent to this can be effected in the conventional manner without interference. [0016] The speed controller can be part of a super-ordinate control device or one comprising further functions, which for example carries out a pressure and/or flow closed-loop control of the circulation pump assembly. This control device can additionally control the switching-over of the mechanical switch device. Alternatively, a separate control device coupled to the speed controller can also be provided for this. [0017] The switch device is preferably designed such that the movements into the at least two different switch positions are effected with different temporal delays, wherein preferably the movements are effected along differently long paths and/or against differently great damping, inertia forces and/or biasing forces. The movements into the different switch positions are thus preferably effected with different dynamics. The temporal delays by way of the differently rapid pressure build-up or pressure reduction in the hydraulic system permit the switch device to be initiated into assuming or retaining a desired one of the possible switch positions. If the pressure for example is rapidly increased, the switch device can carry out a movement into a switch position which is subjected to a lesser delay or damping. A second, more greatly delayed movement, by way of the rapid pressure build-up due to the delay or damping is prevented or slowed down such that that switch position which requires a less delayed movement to be assumed, is reached more quickly. If however the pressure for example is increased more slowly, the delay can be compensated by the slow pressure increase, so that the switch device for example can be held in a switch position or moved into a switch position, in which the greater delay or damping acts. The differently rapid pressure build-up or pressure reduction for example can be effected in a continuous manner with a different gradient or however also in a stepwise manner, e.g. with differently long pauses between the steps or stages. [0018] A desired delay can be achieved in different manner, for example by way of differently long paths of the switch device having to be covered for the individual switch positions. Alternatively or additionally, damping elements can be applied and/or friction forces, inertia forces or biasing forces can counteract the movement for its delay. The switch device can also be designed such that the gravity counteracts a movement into the different switch positions, to a differently great extent. The switch device can be designed in a targeted manner such that a higher damping or delay occurs in at least one movement direction into a first of the switch positions, than in a movement direction into a second switch position. Thereby, it is to be understood that a movement into one of the switch positions in the context of the invention can also mean that the switch device remains in this switch position if it was already previously located in this switch position. [0019] According to a further preferred embodiment of the hydraulic system, the circulation pump assembly is connected to at least two hydraulic circuits, and the mechanical switch device is subjected to fluid pressure via at least one of the hydraulic circuits, in a manner such that the switch device can be moved by way of the forces produced by the fluid pressure. This means that the switch device is preferably subjected to the hydraulic pressure which is produced by the circulation pump assembly, wherein the switch device is designed such that it reacts to the different course of the pressure build-up resulting with a speed change of the circulation pump assembly, in particular with a speed increase as has been described previously, so that it can be moved into a desired switch position in dependence on the type of the course of the pressure build-up. The switch device for example can be arranged such that it is subjected to pressure via the first hydraulic circuit and effects a switching function in the second hydraulic circuit. However, with this function too, the switching-over or the movement of the switch device into the desired switch position is preferably not dependent on the absolute head of a reached pressure, but dependent on the type of pressure course in the hydraulic circuit connecting the circulation pump assembly to the switch device. Particularly preferably, both hydraulic circuits can be connected to the switch device and further preferably also both hydraulic circuits can be connected to the circulation pump assembly, wherein the pump assembly simultaneously causes a fluid flow in both hydraulic circuits, or causes a fluid flow in each case in one of the hydraulic circuits in a selective manner, which is to say in a preferably switchable manner. [0020] Particularly preferably, the circulation pump assembly is connected to at least two hydraulic circuits, and the at least one mechanical switch device is designed as at least one valve with at least one movable valve element for changing the ratio of the flows through the at least two hydraulic circuits and in particular for switching-over a flow path between the at least two hydraulic circuits. Thus the two hydraulic circuits for example can be two circuits of a heating installation, for example a first circuit through a heat exchanger for heating service water, and a second circuit as a heating circuit in a building. The switch device can accordingly be designed as a valve, in particular a switch-over valve, in order to selectively lead the flow produced by the circulation pump assembly, into one of the hydraulic circuits. Thus preferably at least two switch positions of the mechanical switch device are provided, wherein the fluid flow through the first hydraulic circuit is effected in a first switch position, and through the second hydraulic circuit in a second switch position. The switching-over is preferably effected in dependence on the course of the pressure build up or pressure reduction with a speed change, in particular on accelerating or starting up the circulation pump assembly from standstill or departing from a basis speed. [0021] Further preferably, the at least one valve comprises at least one first and a second control surface, upon which a fluid pressure produced by the circulation pump assembly acts, wherein the control surfaces are connected to the at least one valve element in a manner such that the valve element is movable by way of the forces acting on the first and the second control surface. The two control surfaces on the valve element for example can be arranged in opposite directions, which for example means arranged away from one another, so that the valve element can be moved in opposite directions depending upon which of the control surfaces a greater pressure acts. A relocation of the valve element in a desired direction can be achieved by way of a differently rapid pressure build-up, if a suitable delay is then effected in one of the movement directions. The flow path to one of the control surfaces can be designed such that a delayed pressure build-up occurs on the control surface, instead of delaying or braking the valve element in its movement in one direction. This, for example, can be achieved by way of suitable throttle locations, flow resistances and/or for example by way of different lengths of the flow paths which lead to the two control surfaces. [0022] Particularly preferably, the at least one valve comprises at least two valve elements, wherein the first control surface is connected to the first valve element and the second control surface is connected to the second valve element. The control surfaces can thereby be arranged on the valve elements for example such that a fluid pressure acting on the control surfaces produces a pressure force acting in the opening direction of the valve elements, so that the valve elements can be pressed into an opened position by way of a suitably high fluid pressure. A reverse arrangement is alternatively possible, with which fluid pressure acting upon the control surfaces produces a pressure force acting in the closure direction of the valve elements, so that the valve elements can be pressed into a closed position by way of a suitably high fluid pressure. The two valve elements preferably have different dynamic characteristics, which for example can be achieved for example by a different damping, delay or inertia forces directed counter to the movement, as has been described beforehand. The valve elements react differently to different dynamics of the pressure build-up or pressure reduction, in particular to differently rapid pressure changes in the system, on account of the different dynamic characteristics. As described beforehand, the two valve elements are therebypreferably designed such that they move with a differently large delay and/or move counter to differently large biasing forces. Thus one can succeed in one of the valve elements being selectively moved first of all, by way of the different speed of a pressure change. [0023] The control surfaces can be formed directly on an associated valve element, in particular formed on the valve element as one piece, said valve element causing the closure of a flow path. However, it is also possible for the control surfaces to be designed on a separate component which is connected in a suitable manner to an associated valve element or is coupled to this, for movement and force transmission. [0024] The switch device according to a further preferred embodiment is situated at the entry side of the hydraulic circuits. Thus the switch device for example at the entry side of the hydraulic circuits can serve for selectively guiding a flow into one of the hydraulic circuits. The arrangement at the entry side of the hydraulic circuits has the advantage that a higher fluid pressure, namely the entry-side fluid pressure which is not yet reduced due to pressure losses in the hydraulic circuits, acts upon the switch device at this location. Thus, preferably a greater fluid pressure is available for moving the switch device into a desired switch position. [0025] Further preferably, the switch device is arranged at the delivery side of the circulation pump assembly. This means that the switch device in the flow path between the delivery side and the suction side of the circulation pump assembly is situated closer to the delivery side of the circulation pump assembly than to the suction side. This means that a pressure loss between the switch device and the circulation pump assembly situated downstream is greater than the pressure loss between the exit side of the circulation pump assembly and the switch device. The mechanical switch device is particularly preferably arranged directly on or behind the delivery side of the circulation pump assembly, so that essentially no pressure loss occurs between the delivery side of the circulation pump assembly and the switch device. This means that here only a negligible pressure loss occurs in comparison to the pressure loss occurring in the remaining hydraulic circuit. Particularly preferably, the switch device can be integrated into a pump casing, directly at the delivery side of the circulation pump assembly. [0026] Alternatively, it is also possible to arrange the mechanical switch device at the suction side of the circulation pump assembly. This means that with this embodiment, the mechanical switch device is situated closer to the suction side of the circulation pump assembly than to the delivery side. This means that preferably a pressure loss between the delivery side of the circulation pump assembly and the mechanical switch device, in a hydraulic circuit between the delivery side and the suction side of the circulation pump assembly, is greater than between the mechanical switch device and the suction side of the circulation pump assembly. The arrangement of the switch device at the suction side has the advantage that different hydraulic characteristics of the hydraulic circuits connecting the delivery side of the circulation pump assembly to the switch device can be utilized for the movement of the switch device. Thus for example one of the hydraulic circuits can be longer and/or have a greater flow resistance, so that a delayed pressure build-up at the switch device occurs via this hydraulic circuit. The arrangement at the suction side of the circulation pump assembly, which is to say preferably at the exit side of the mentioned hydraulic circuits also permits a switch-over between the hydraulic circuits, depending on which of the hydraulic circuits is opened to the suction side of the circulation pump assembly by the switch device. [0027] The arrangement of the switch device at the suction side or delivery side of the circulation pump assembly can moreover be dependent on spatial or geometric designs of the hydraulic system or of the pipe conduits forming the hydraulic system. [0028] According to a further preferred embodiment, the mechanical switch device is situated downstream of a first heat exchanger in the hydraulic system. Such a first heat exchanger in the hydraulic system leads to a pressure loss between the circulation pump assembly and the mechanical switch device. Such a first heat exchanger, which is to say a primary heat exchanger, in a heating or cooling system for example can serve for the temperature control of a heat transfer medium which circulates in the hydraulic system. Thus the first heat exchanger can be situated in a boiler or in a heat storage means or for example be formed by a solar collector or cooling assembly. [0029] The switch device is moreover preferably additionally affected by gravity, at least one magnet force and/or at least one spring force, which acts in the direction of at least one movement axis, i.e. a movement direction of the switch device. The valve elements for example in one movement direction can be subjected to a biasing force which can be formed by gravity and/or by a magnet force and/or by a spring force, in the case that the switch device is designed as a valve with one or more valve elements. In the case of a valve, the valve element for example can be impinged by such a biasing force in the closure direction. However, a reverse design is also possible, in which the biasing force impinges the valve element in the opening direction. Such a biasing force can serve for holding the switch device and in particular a valve element of the switch device in a desired idle position when the circulation pump assembly is not in operation or for example runs with a basis speed which is reduced with respect to normal operation. It is thus ensured that the switch device or its valve elements always assume a defined starting position or a defined idle position. The switch device can then be moved out of this idle position into a desired switch position by way of the selection of the course of the pressure build-up, by way of a suitable speed control of the circulation pump assembly. The switch device for example with a first course of the pressure build-up can remain in its first switch position which corresponds to the idle position and with a second course of the pressure build-up which is different can be moved into a second switch position. [0030] The described biasing force which is to say e.g. the gravity force and/or the at least one magnet force and/or spring force is preferably directed opposite to a hydraulic force which acts on the switch device and is produced by the circulation pump assembly. Thus the switch device, in particular a valve element of the switch device, can be held in a defined starting or idle position for example by way of gravitational force, magnet force and/or spring force and be moved counter to the biasing force by way of a suitable pressure build-up which creates a hydraulic force on a control surface of the switch device. The hydraulic force is thereby produced by the circulation pump assembly via the delivered fluid. [0031] According to a particularly preferred embodiment, the switch device comprises at least two valve elements as has been described beforehand, wherein in the idle position each valve element is held in a first switch position by way of a biasing force, such as gravitational force, and/or magnet force and/or spring force, and the valve elements as well as the gravity force, magnet force and/or spring force are designed such that one of the valve elements is firstly moved into a second switch position by way of the fluid pressure, in dependence on the course of the speed change of the circulation pump assembly. The first switch position can be a closed or an opened switch position, depending on the design. Accordingly, the second position is an opened or closed switch position. The idle position is then preferably assumed by the valve element when the circulation pump assembly is switched off and or rotates with a basis speed which is lower than the normal operational speed. This idle position is then defined and held by the occurring mentioned biasing force. The closed switch position of the valve element is thereby achieved by way of the valve element bearing on a corresponding valve seat. Thereby, a sealed contact can be envisaged, by way of which the valve is completely closed. However, a contact with a predefined minimal opening can also be provided, so that the flow path through the valve element is not completely closed in the closed switch position, but is only reduced to a minimum. The valve element is moved via the fluid pressure in dependence on the speed set by the speed controller or on the course of the speed change which is set by the speed controller. The valve element is thereby moved into an opened or into a closed switch position, depending on the design of the switch device, so that the cross section of the flow path between the valve element and the associated valve seat is enlarged or reduced. Differently high rotation speeds or differently rapid courses of the speed changes can be selected for example, in order to be able to move one of the valve elements into one of the switch positions in a targeted manner. Thus for example a first valve element can be moved into a first switch position given a slower course of the speed change, whereas a second valve element can be moved into the first switch position given a quicker course of the speed change, wherein the respective other valve element remains in its second switch position. [0032] Further preferably, the first and the second valve element in their movement direction between the switch positions have a differently large travels, are damped to a different extent and/or have differently large inertia forces, friction forces and/or biasing forces which are opposite to this movement direction. A differently large travel of the valve elements in particular means the travel which the valve element must cover between its closed and its opened position or vice versa. Further preferably, this travel is that path which the valve element must cover, until, as described further below, the other valve element is blocked. One can succeed in one of the valve elements reacting, i.e. opening or closing, more quickly to pressure changes than the other, due to the differently large travels and/or differently large damping or braking forces such as inertia forces, friction forces and/or biasing forces which are counter to the movement. Thus one of the valve elements can be moved in a targeted manner into a first switch position in dependence on the speed of the pressure build-up or pressure reduction. The first switch position can be an opened or a closed switch position of the valve element, depending on the design. It is also possible to delay the pressure build-up or pressure reduction on the control surface of the respective valve element instead of damping the valve element itself or of delaying it in its movement into its first switch position. This can be achieved for example by way of throttle elements in the flow path or by way of differently long or differently designed flow paths between the circulation pump assembly and the valve elements. This one can succeed in a pressure departing from the circulation pump assembly propagating differently rapidly to the valve elements by way of the targeted different design of the flow paths between the circulation pump assembly and the valve elements. [0033] According to a particular embodiment of the invention, at least one of the valve elements can be provided with a delay device, wherein the delay device is designed in a manner such that fluid which flows through the valve along this valve element effects the delay. This means that the valve element is designed such that it is delayed in its movement into the opened switch position by way of hydraulic forces which are caused by the fluid itself, which flows through the valve. This has the advantage that one can make do without additional delay and damping means which could be prone to error. Hydraulic forces acting in a delaying manner can be achieved by way of a suitable leading of the flow paths. There exits the advantage that the fluid itself flushes the respective flow paths, since the fluid flowing through the valve produces these forces, so that a dirtying with the malfunctioning entailed by this can be avoided. [0034] The delay device for example can thus have a valve gap which extends transversely to the movement axis of the valve element, between the valve element and a corresponding valve seat and which can preferably be changed in its gap width by way of a movement of the valve element along the movement axis. Forces acting upon the valve element can occur in such a valve gap when being subjected to through-flow and these forces counteract hydraulic forces acting upon a control surface of the valve element in a first movement direction. These forces can change, in particular reduce with a movement of the valve element due to a change of the gap width, so that they do not essentially counter the movement of the valve elements but only delay this. This means that the delay or damping forces preferably reduce with the movement of the valve element, and this can be effected for example by way of an enlargement of the valve gap extending transversely to the movement axis. The first movement direction can thereby preferably be the opening direction of the valve. [0035] According to a particular embodiment of the invention, the valve can be designed such that the valve gap is closed in one switch position. This does not need to be the closed switch position of the valve or valve element, but rather the valve gap can close during the movement and then also open again at a later stage as the case may be. Targeted delay or damping forces can therefore be generated. [0036] A valve with one of the valve elements for example can be designed such that the valve element departing from a first switch position firstly closes by a certain amount and subsequently opens further, with the movement of this valve element along its movement axis. The first switch position thereby can be the closed switch position, whereas the second switch position is the opened switch position. A valve gap can be formed in the valve element, as has been previously described. Increasing damping or delay forces on movement of the valve element can thus be produced if this valve gap firstly closes by a certain amount on movement of the valve element. However, if these forces are lower than the hydraulic forces which are produced by the fluid pressure on the control surface of the valve element, the valve element is moved further and opens further, wherein the valve gap for example can enlarge again, so that the damping or delay forces then reduce, so that these no longer counteract a reaching of the second switch position, i.e. for example a complete opening of the valve or the valve element. [0037] According to a particularly preferred embodiment of the invention, the first and the second valve element are coupled in a manner such that always only one valve element can be located in its opened switch position or always only one valve element can be located in its closed position. This means that the valve elements are preferably arranged and designed such that they mutually block one another in their movement. The valve elements preferably comprise guide pins, whose movement paths intersect one another, so that when a guide pin of one valve element is located in the movement path of the guide pin of the other valve element, this other valve element is prevented from moving. The guide pins further preferably serve for the linear guiding of the valve elements along the predefined movement paths. If a valve element firstly moves into a second switch position for example by way of a rapid pressure build-up, one succeeds in a second valve element which is delayed in its movement subsequently likewise still being able to move into its second switch position, on account of the coupling or the mutual blocking. The first switch position can be an opened switch position and the second switch position can be a closed switch position or however the first switch position can be a closed switch position and the second switch position can be an opened switch position, depending on the design. A delay of the movement of a valve element can be effected for example also by way of a longer path which this valve element must cover, until it blocks the other valve element in its movement. [0038] Particularly preferably, a first valve element is biased with a lower biasing force in its first movement direction than the second valve element. The first valve element is simultaneously preferably designed such that it is moved in a delayed manner compared to the second valve element, with a pressure build-up. With a slow pressure build-up, one succeeds in this delay being able to be compensated and the first valve element firstly moving counter to the biasing force into a second e.g. opened switch position on account of the weaker biasing force, with this design. If the fluid pressure then increases further, in particular increases to the extent that the biasing force of the second valve element is also overcome, then this can no longer move into its second switch position due to the coupling or block by the first valve element. If conversely however a rapid pressure build-up, up to a fluid pressure overcoming the biasing force of the second valve element, is effected, then one can prevent the first element moving so far that it blocks the second valve element before the second valve element is in its second switch position, due to the delay of the movement of the first valve element. This means that the second valve element moves so rapidly into its second position, that it is quicker in the second switch position than the first valve element. If the second valve element however is in its second switch position, then via the coupling it preferably blocks the first valve element in a manner such that this can no longer move into its second switch position. [0039] At least one of the two valve elements is preferably designed such that it can move by a certain amount in the direction of its movement axis, without changing the switch condition of the valve, i.e. without opening the valve. According to a first preferred embodiment, the valve element biased to a greater extent is designed in this manner. However, the valve element which is biased to a lesser extent can alternatively or additionally also be designed in this manner. The more greatly biased valve is thereby preferably that valve which is situated in that hydraulic circuit of a heating installation, in which a secondary heat exchanger for heating service water is arranged. The more weakly biased valve in the case of a hydraulic circuit of a heating installation is preferably that valve which is situated in the hydraulic circuit forming a heating circuit for a building. The possibility of the movement of the valve element without opening the valve has the advantage that on coupling the valve elements, the valve element can move by an amount which is sufficient to block the other valve element in its movement, before the first, i.e. the valve element moving first of all, reaches its second switch position. [0040] According to a further preferred embodiment, the hydraulic system is designed such that the flow of the circulation pump assembly is detected at least in certain operating conditions. The flow can be detected by a flow sensor or preferably by way of electrical variables of the circulation pump assembly by a suitable control device. The flow is preferably detected during the speed change and thus the pressure change for actuating the switch device. If no flow is ascertained for example in a first switch position, in which the heating circuit of a building is supplied with heating medium in a heating system, then this is an indication that there is no thermal demand in the heating circuit. This can be the case for example if all thermostat valves are closed in the heating circuit. The control device is preferably designed such that it does not increase the speed via the speed controller any further when no flow is detected. Such a further speed increase would unnecessarily increase the energy consumption. The control device can preferably also be designed such that it detects the valve position of the switch device by way of the flow. [0041] Further preferably, the movement axes or movement directions of the first and second valve element are angled to one another, particularly preferably at right angles to one another, wherein the movement axes preferably intersect. A very simple blocking or coupling of the two valve elements in the previously described manner can be achieved by way of this. A blocking for example can be effected by way of a valve element moving into the movement path along the movement axis of the other valve element and thus blocking the further movement of the other valve element. Particularly preferably, as previously described, guide pins of the two valve elements can extend along movement paths which are angled to one another or intersect each other, in order to achieve a mutual blocking of the valve elements, so that it is always only one valve element which can be in a second switch position. Thereby, the second switch position can be an opened or a closed switch position, depending on the design. [0042] The hydraulic system according to the invention is particularly preferably designed as a hydraulic heating system and/or cooling system, wherein preferably of the at least two hydraulic circuits, a first hydraulic circuit runs through the object to be temperature-controlled and a second hydraulic circuit runs through a secondary heat exchanger for the temperature control of the service water. [0043] The object to be temperature-controlled for example can be a building, and the first hydraulic circuit runs through one or more radiators or floor heating circuits of the building. A primary heat exchanger, through which the fluid is first delivered, in order to control it with regard to temperature, which is to say heat it or cool it, can be situated upstream of both hydraulic circuits. The described mechanical switch device is preferably switched such that the fluid is delivered from the circulation pump assembly through the second hydraulic circuit running through the described secondary heat exchanger, if service water is to be heated or cooled. If a temperature control of service water is not desired, then the mechanical switch device is brought into its other switch position, in which the fluid is delivered by the circulation pump assembly through the first hydraulic circuit which runs through the object to be temperature controlled. [0044] Such a design in particular is suitable with compact heating installations as are used for apartments and smaller buildings. With this installations, it is advantageous that one can make do without an additional drive for the switch device due to the switch device according to the invention which is actuated exclusively by way of variation of the speed or the speed course of the pump assembly, by which means the manufacturing costs for such a heating installation are reduced, and the failure risk is reduced. [0045] Particularly preferably, the switch device comprises a first valve element in the mentioned first hydraulic circuit running through the object/building to be temperature-controlled, and a second valve element in the second hydraulic circuit running through the secondary heat exchanger, wherein the first valve element in the first movement direction is biased with a lesser force than the second valve element, and the first valve element in the second opposite movement direction in its movement is damped or delayed to a greater extent than the second valve element. The first movement direction can be the closure direction or the opening direction of the valve element, depending on the design. The second movement direction is then always the opposite movement direction. One can succeed in the second valve element being firstly moved into its second switch position with a slower speed change of the circulation pump assembly and a slower course of the pressure build-up or pressure reduction which is entailed by this, whereas the first valve element is firstly moved into its second switch position by way of a quicker course of the speed change or a quicker course of the pressure build-up or pressure reduction, with this design. Preferably, the two valve elements, as previously described, are thereby coupled to one another such that if one of the valve elements is in its second switch position, the other valve element can no longer move into its second switch position. The speed change can thereby be effected linearly or in a constant manner or also in steps or stages, as the case may be with differently long pauses between the steps, as has been described previously. [0046] Further preferably, the circulation pump assembly and the at least one switch device are arranged in a common construction unit, in particular an integrated hydraulic construction unit for a compact heating installation. The subject matter of this invention is therefore also such a construction unit, in particular a construction unit for a compact heating installation, which comprises a circulation pump assembly and the at least one switch device. Thereby, the circulation pump assembly and the switch device preferably comprise at least one common housing part. It is to be understood that this construction unit can be realized together with one or more of the previously described features, in particular with features of the switch device. [0047] The arrangement in a construction unit means that the switch device and the circulation pump assembly are arranged in the constructional vicinity of one another. The integrated hydraulic construction unit for a compact heating installation usually comprises the circulation pump assembly as well as the necessary valves and sensors and is further preferably connected directly to a secondary heat exchanger. Thus in a heating installation it only needs to be connected via external pipework to a primary heat exchanger, a service water feed, a service water discharge and the connections of an external heating circuit. It thus forms the central hydraulic constituent of the heating installation. The integrated hydraulic construction unit is preferably formed from one or more components, in which the necessary flow paths between the switch device, the circulation pump assembly and the mentioned secondary heat exchanger are situated. Preferably, the components of the integrated hydraulic construction unit are manufactured as injection molded parts of plastic. [0048] The switch device particularly preferably lies directly on the circulation pump assembly and is preferably integrated into a pump casing of the circulation pump assembly. Thus, the switch device can for example be arranged in the suction chamber of the pump casing, preferably behind or directly adjacently at a partition wall separating the suction chamber from the pressure chamber of the pump casing. A particularly compact construction is therefore achieved. The switch device can alternatively also be integrated into the pump casing at the delivery side. [0049] The switch device preferably comprises three hydraulic connections, wherein a first hydraulic connection is connected directly to the suction side or the delivery side of the circulation pump assembly, a second hydraulic connection is connected to a hydraulic circuit running through a secondary heat exchanger and a third connection is connected to a hydraulic circuit which runs through an object to be temperature-controlled. It is particularly with an integrated, hydraulic construction unit that the connections are thereby preferably situated such that the second hydraulic connection is arranged at an angle, in particular at right angles, to the third hydraulic connection. The third hydraulic connection thereby further preferably extends vertically downwards in the installed condition of the construction unit, whereas the second hydraulic connection extends horizontally. This is advantageous, since a secondary heat exchanger which for example can be designed as a plate heat exchanger, as a rule is situated at the rear side of the hydraulic construction unit in heating installations, whereas the external connections for connection of the hydraulic circuit running to an object to be temperature-controlled, as well as the further external connections, for example service water feed and service water discharge, as a rule extend vertically downwards. Thus the connections of the switch device can be connected directly to the necessary connections of the hydraulic construction unit or form these. The angled arrangement of the connections moreover favors the angled arrangement of the valve elements situated on the connections, in the manner described above, by way of which valve elements the coupling or the mutual movement blocking can be achieved. [0050] According to a further particular embodiment of the invention, a valve element of the switch device in the first hydraulic circuit has a perpendicular movement axis, and a valve element in the second hydraulic circuit has a horizontal movement axis, wherein the horizontal movement axis preferably extends parallel to a rotation axis of the circulation pump assembly. This arrangement favors the integration into an integrated hydraulic construction unit of a compact heating installation, since the special arrangement of the connections as has been described previously and which corresponds to the common arrangement of the connections on such a construction unit, results by way of this arrangement. The rotation axis of the pump assembly with such construction units as a rule is directed such that it extends normally to the extension of a secondary heat exchanger, in particular parallel to the entries and exits of such a secondary heat exchanger. [0051] The invention is hereinafter described by way of example and by way of the attached figures. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated. BRIEF DESCRIPTION OF THE DRAWINGS [0052] In the drawings: [0053] FIG. 1 is a schematic view of a hydraulic system according to the invention; [0054] FIG. 2 is a sectioned view of a switch device for a hydraulic system according to the invention, according to a third embodiment; [0055] FIG. 3 is a sectioned view of the switch device according to FIG. 2 , in a first switch position; [0056] FIG. 4 is a sectioned view of the switch device according to FIG. 2 , in a second switch position; [0057] FIG. 5 is a sectioned view of a switch device for a hydraulic system according to the invention, according to a fourth embodiment; [0058] FIG. 6 is a sectioned view of the switch device according to FIG. 5 , in a first switch position; [0059] FIG. 7 is a sectioned view of the switch device according to FIG. 5 , in a second switch position; [0060] FIG. 8 is a sectioned view of a pump assembly with an integrated switch device according to a fifth embodiment of the invention; [0061] FIG. 9 is an exploded view of a circulation pump assembly with an integrated switch device according to a sixth embodiment of the invention; [0062] FIG. 10 is a sectioned view of the pump casing according to FIG. 9 ; [0063] FIG. 11 is a sectioned view of a valve with a delay device; [0064] FIG. 12 is a sectioned view of a valve block with the valve according to FIG. 11 , in a first switch position; [0065] FIG. 13 is a sectioned view of the valve block according to FIG. 12 in a second switch position; [0066] FIG. 14 is a diagram schematically showing the two different spring characteristics of two valves according to FIG. 2-8 as well as 12 and 13 ; and [0067] FIG. 15 is a sectioned view of an alternative design to the design according to FIG. 10 . DESCRIPTION OF THE PREFERRED EMBODIMENTS [0068] Referring to the drawings, FIG. 1 shows a heating installation as an example for a hydraulic system according to the invention. This heating installation uses a fluid heat transfer medium, in particular water, which is delivered in the circuit through the hydraulic system. The hydraulic system for this comprises a circulation pump assembly 2 . The circulation pump assembly can be designed in a conventional manner, which is to say can comprise at least one impeller driven by an electric motor which is preferably designed as a canned motor, which is to say as a wet-running electrical drive motor. Further preferably, an electronic control is arranged directly on the circulation pump assembly or is integrated into the circulation pump assembly, by way of which control the pump assembly can be closed-loop controlled in its speed. The electronic control for this, in particular can comprise a frequency converter. The electronic control is particularly preferably arranged in an electronics housing or terminal box 4 which forms part of the circulation pump assembly 2 which means in particular is arranged directly on the motor housing or stator housing. [0069] The hydraulic system moreover comprises a primary heat exchanger 6 which is arranged downstream of the circulation pump assembly 2 . Here, the primary heat exchanger 6 is shown as a heating boiler. However, it is to be understood that the primary heat exchanger 6 for example can also be a cooling assembly or another heat source or cold source. The hydraulic system moreover comprises a secondary heat exchanger 8 which serves for the temperature control (here for heating) of service water. The secondary heat exchanger 8 for this comprises two flow paths, wherein the heating circuit running through the circulation pump assembly 2 and the primary heat exchanger 6 runs through a first flow path, and a service water conduit 10 for the service water to be heated runs through a second flow path. This flow path of the heating circuit through the secondary heat exchanger 8 forms a second hydraulic circuit B, whereas a first hydraulic circuit A as a room heating circuit leads through one or more radiators 10 of a building to be heated or temperature-controlled. It is to be understood that also other suitable heat exchangers, for example also one or more circuits of a floor heating could be applied as a heating body or radiator 10 . The first hydraulic circuit A and the second hydraulic circuit B via the circulation pump assembly 2 and the primary heat exchanger 6 in each case form closed hydraulic circuits, in which the heat-transfer medium is circulated. [0070] At the entry side, the hydraulic circuits A and B branch way from one another at a branching point 12 and at the exit side are connected to one another again at the second branching point 14 . A switch device in the form of a switch-over valve which selectively opens one of the flow paths through one of the hydraulic circuits A and B and closes the flow path through the respective other hydraulic circuit is arranged at the branching point 12 or the branching point 14 , in order to lead the flow of the heat transfer medium which is produced by the circulation pump assembly 2 , through the hydraulic circuit at the exit side of the primary heat exchanger 6 selectively through the first hydraulic circuit A or the second hydraulic circuit B. [0071] The part of the hydraulic system which is outlined in a dashed manner in FIG. 1 can be integrated into a heating installation, preferably into a compact heating installation 16 , wherein all components with the exception of the primary heat exchanger 6 and the secondary heat exchanger 8 can be integrated into a construction unit such as a hydraulic block. Such a heating installation 16 then essentially comprises four hydraulic connections, specifically firstly a service water entry 18 and a service water exit 20 as well as for the first hydraulic circuit A, a feed connection 22 and a return connection 24 . The heating installation 16 is connected in the known manner to external pipework via these four hydraulic connections 18 , 20 , 22 and 24 . [0072] A switch-over valve which is electrically driven, in order, activated by a control device when heated service water is delivered, to lead the heat transfer medium flow through the secondary heat exchanger 8 and then, when heat is demanded in the room heating circuit, which is to say at the radiator 10 , to lead heat transfer medium flow through the first hydraulic circuit A and thus through the radiator or radiators 10 , is arranged in known heating installations 16 at the branching point 12 or the branching point 14 . According to the invention, one now envisages making do without such a separate electrical drive of a switch-over device or a switch-over valve and effecting the switching-over solely by way of a suitable activation of the circulation pump assembly 2 . A control device 26 is provided for this, which for example can be a central control device 26 which also controls the primary heat exchanger 6 in the form of a burner and detects the service water demand via at least one suitable sensor. The control device 26 can be designed as a separate component or for example also be integrated with the control device of the circulation pump assembly 2 into a control device, in particular also completely arranged in the electronics housing 4 of the circulation pump assembly 2 . The control device 26 provides the control of the circulation pump assembly 2 with a signal, as to whether a service water heating or a supply of the room heating circuit with the heat-transfer medium is desired. The electronic control of the circulation pump assembly 2 which forms a speed controller then controls the circulation pump assembly 2 such that the flow is selectively led through one of the hydraulic circuits A and/or B via a mechanical switch device in the branching point 12 or the branching point 14 . Thereby, the mechanical switch device is coupled to the circulation pump assembly 2 in a purely hydraulic manner via the fluid, which is to say the heat transfer medium which is delivered by the circulation pump assembly 2 . [0073] Examples for such switch devices are described hereinafter. [0074] With the described embodiments of the invention, the switch device is designed as a valve with two valve elements, wherein embodiments for the arrangement at the branching point 12 or for the arrangement at the branching point 14 are described. [0075] The embodiment of a switch device which is described by way of FIGS. 2-4 is envisaged for the arrangement on the delivery side of the circulation pump assembly 2 , which is to say at the branching point 12 . Only the pressure loss of the primary heat exchanger 6 acts at this branching point 12 , the more significant pressure loss in the hydraulic circuits A and B is however effected between the branching points 12 and 14 through the secondary heat exchanger 8 and the radiators 10 . [0076] The switch device comprises a housing in the form of a valve block 78 which comprises a pressure-side connection 80 for connection to the branch P of the hydraulic circuits, which is to say to the exit side of the primary heat exchanger 6 . The valve block 78 moreover comprises two exit-side connections 82 and 84 , of which the connection 82 is connected to the first hydraulic circuit A which is to say via the feed connection 22 to the radiators 10 , and the connection 84 is connected to the second hydraulic circuit B which is to say to the secondary heat exchanger 8 . [0077] Two valves 86 and 88 are arranged in the valve block 78 . The valves 86 and 88 together form a switch device and are each designed in the manner of check valves. Thereby, the valve 86 lies in the flow path between the connection 80 and the connection 82 for the first hydraulic circuit A and the valve 88 lies in the flow path between the connection 80 and the exit-side connection 84 for the second hydraulic circuit B. Both valves 86 , 88 are closed in a first switch position, in the idle position shown in FIG. 2 , which is to say that the valve element 90 of the valve 86 bears on the valve seat 94 and the valve element 92 of the valve 88 bears on a corresponding valve seat 96 . The valve 86 comprises a compression spring 98 and the valve 88 a compressing spring 100 , which produce a biasing force and press the respective valve element 90 , 92 into the closed idle position shown in FIG. 2 . The compression springs 98 and 100 are differently dimensioned. The first valve 86 has a weaker compression spring 98 than the compression spring 100 of the second valve 88 . [0078] The different dimensioning of the compression springs 98 and 100 is represented in FIG. 14 . FIG. 14 schematically shows a characteristic S 1 of the compression spring 100 and the characteristics S 2 of the compression spring 98 . The force F is plotted over distance S in the diagram according to FIG. 14 , wherein the force F in this diagram is not the spring force, but the produced pressure or the produced delivery head of the circulation pump assembly 2 at its delivery side. It is to be recognized that the weaker compression spring 98 produces a lower biasing force than the stronger compression spring 100 . In the closed idle position, in which the associated valve element has not yet moved in the opening direction, a delivery head of 2 m is necessary in this example, in order to open the first valve 86 , whereas a delivery head of 4 m is necessary, in order to effect an opening procedure of the valve 88 which comprises the stronger compression spring 100 . It is simultaneously to be recognized that in this embodiment, the weaker compression spring 98 has a somewhat steeper spring characteristic S 2 , by which means the delayed movement of the valve 86 or its valve element 90 is encouraged. One can recognize from the diagram according to FIG. 14 that with a slow pressure build-up for example between 2 m and 4 m delivery head, the valve 86 with the weaker compression spring 98 can be opened by way of a movement of the associated valve element 90 into the second switch position, before the valve element 92 of the second valve 88 moves. Thus, the valve element 90 can be firstly moved into a position, in which the opening of the valve element 92 is blocked, before the pressure is increased to such an extent that also the valve element 92 is moved into its opened position, as described below. [0079] The valve 86 is additionally provided with a damping or delay device 102 . The delay device 102 has a closed fluid-filled space, into which a cylindrical piston 104 of the valve element 90 immerses with its movement into the opened position. Fluid can escape out delayed of the closed volume of the delay device 102 via an opening 106 functioning as a throttle location, when the piston 104 immerses into the volume. Thus a damping or delay of the movement of the valve element 90 in the opening direction v occurs. [0080] In turn, it is possible by way of variation of the pressure build-up on accelerating the pump assembly 2 , to open one of the valves 86 and 88 in a targeted manner by way of the combination of the weaker compression spring 98 with this delay device 102 . The valve element 92 , since it is not delayed in its movement, will move more quickly into in its opening direction w than the valve element 90 which is delayed in its movement by the delay device 102 , if a rapid pressure build-up, for example with a steep ramp for the acceleration or an abrupt increase to a high operating pressure is selected. A pressure which is only sufficient to overcome the spring force of the compression spring 98 which is designed more weakly, but is not yet sufficient to move the valve element 92 against the pressure force of the compression spring 100 , is firstly reached in the connection 80 , if a slower pressure build-up with several steps or with a shallower ramp is selected for the acceleration and the pressure build-up. This means that the valve element 90 will the firstly move in the opening direction v into its opened switch position. The second valve element 92 only then moves against the compression spring 100 , if the pressure acting upon the valve element 92 at its face side hydraulically facing the connection 80 is sufficiently large to overcome the counteracting spring force. [0081] The valve elements 90 and 92 are moreover designed such that they are mechanically coupled or mutually block one another. The movement axes or opening directions v and w of the two valve elements 90 and 92 are angled at an angle of 90 to one another and intersect one another. Moreover, the valve element 90 at its axial end which is away from the valve seat 94 comprises a pin-like extension 108 which forms a guide pin. Accordingly, the second valve element 92 at its end which is away from the valve seat 96 comprises a pin-like extension 110 which forms a guide pin. The pin-like extension 108 extends in the direction of the movement axis or opening direction v of the valve element 90 . The pin-like extension 110 extends along the longitudinal axis or movement axis or opening direction w of the second valve element 92 . The pin-like extensions 108 and 110 are dimensioned such that if the valve element 90 is located in its opened position, its pin-like extension 108 projects into the movement path of the valve element 92 , so that its pin-like extension 110 comes to bear on the outer periphery of the pin-like extension 108 . This condition is shown in FIG. 4 . This prevents the second valve element 92 from also being able to move into its opened position or switch position with a further pressure increase, when the first valve element opens firstly with a slow pressure build-up. This means that even if the pressure in the connection 80 , which acts upon the valve element 92 increases to such an extent that the hydraulic force exceeds the force of the compression spring 100 , the valve element 92 can no longer move into its opened position. If conversely, the second valve element 92 is opened first of all, then its pin-like extension 110 moves into the movement path of the pin-like extension 108 of the first valve element 90 , so that given an opening movement, the pin-like extension 108 of the valve element 90 abuts on the outer periphery of the pin-like extension 110 , as is shown in FIG. 3 . This means that the first valve element 90 can subsequently no longer move into its opened position or switch position, and a second switch position of the complete valve arrangement is achieved, when the valve element 92 firstly moves into its opened position with a rapid pressure build-up. [0082] Thus with this embodiment too, the switch device can be switched solely by the hydraulic force which acts from the circulation pump assembly 2 onto the delivered fluid or the heat transfer medium. This hydraulic force acts in the form of a pressure upon the control surfaces of the valve elements 90 and 92 . The delay of the pressure build-up from the circulation pump assembly 2 up to the valve elements 90 and 92 is equal since the valve elements 90 and 92 both lie at the branching point 12 . Despite this, both valves 86 and 88 do not react equally rapidly, since the valve element 90 of the valve 86 is braked in its movement by way of the delay element 102 , and thus the valves 86 and 88 have different dynamics. [0083] FIGS. 5-7 show a further embodiment example for a switch device similarly to the switch device which has been described by way of FIGS. 3 and 4 , with the difference that the switch device according to FIGS. 5-7 is provided for arrangement at the branching point 14 , which is to say is provided at the suction side of the circulation pump assembly 2 . [0084] With this embodiment, the valve block 112 comprises an outlet 114 which is provided for connection to the suction side of the circulation pump assembly 2 . Moreover, two inlets 116 and 118 are present in the valve block, wherein the inlet 116 is connected to the exit side of the hydraulic circuit A and the inlet 118 is connected to the exit side of the hydraulic circuit B. This means that the inlet 116 has a connection to the return connection 24 , and the inlet 118 has a connection to the secondary heat exchanger 8 , inasmuch as the valve block 112 is applied with the embodiment example according to FIG. 1 . A first valve 120 is arranged in the inlet 116 and a second valve 122 is arranged in the inlet 118 . FIG. 5 shows the first switch position of the two valves 120 , 122 which forms the idle position, wherein with regard to the valve 120 , the valve element 124 bears on a valve seat 126 . In the second valve 122 , a valve element 128 bears on a valve seat 130 . Each of the valves comprises a compression spring 132 , 134 which press the valve elements 124 and 128 into the closed position shown in FIG. 5 . With this embodiment too, the compression spring 134 is designed more weakly than the compression spring 136 . I.e. the compression spring 136 has a greater spring constant and/or a greater biasing than the compression spring 134 , as explained by way of the previous embodiment. The valve 120 moreover is provided with a delay device 102 , as has been described by way of FIGS. 2-4 . This description is referred to at this location. The valve elements 124 and 128 also comprise pin-like extensions 108 and 110 as have been described by way of FIGS. 2-4 . A uniform pressure force does not act upon the valves 120 and 122 according to FIGS. 5-8 , upon the control surfaces on the sides of the valve elements 124 and 128 which face the inlets 116 and 118 , in contrast to the embodiment example according to FIGS. 2-4 . Instead, a uniform suction force acts via the outlet 114 onto the opposite side of the valve elements 124 and 128 . However, with this embodiment example too, a switching of the valves 120 and 122 can be achieved solely via the type of the course of the pressure increase on acceleration of the circulation pump assembly 2 , due to the different valve dynamics. [0085] An adequately strong vacuum will quickly build up at the outlet 114 and via the hydraulic circuit B a pressure will build up at the inlet 118 which displaces the valve element 128 against the compression spring 136 in the opening direction w and thus opens the valve 122 , if a rapid acceleration with a rapid pressure build-up to a predefined pressure sufficient to overcome the stronger compression spring 136 is selected. The pin-like extension 110 of the valve element 128 simultaneously displaces into the movement path of the valve element 124 and its associated pin-like extension 108 . Given an opened valve 122 , thus an opening of the valve 120 delayed in its movement is therefore prevented by way of the pin-like extension 108 of the valve element 124 abutting on the pin-like extension 110 . Thus a first switch position of the complete valve arrangement is achieved. The delayed movement of the valve element 124 is effected via the delay device 102 . The pressure build-up to the inlet 116 via the first hydraulic circuit A can additionally be effected in a delayed manner, as described above by way of the first embodiment example. With a suitable design, this delay could also be sufficient to the extent that one could make do without the delay device 102 in this embodiment example. [0086] Due to the lower spring force of the compression spring 134 , firstly only the valve element 124 will move in the opening direction v as is shown in FIG. 7 , if the pressure build-up is effected more slowly or in a stepwise manner, firstly to a pressure which is lower than the pressure which is necessary to displace the valve element 128 against the compression spring 136 . I.e. the valve 120 opens first of all. The second valve 122 is then blocked via the pin-like extension 108 , so that this valve can no longer open. Thus a second switch position of the valve arrangement formed by the valves 120 and 122 is achieved. The valve elements 124 and 128 are moved via their compression springs 134 and 136 respectively back into the initial position shown in FIG. 5 , with the stoppage of the circulation pump assembly and the pressure reduction. [0087] The arrangement of two valves 120 and 122 as has been described by way of FIGS. 5-7 can also be integrated directly into a pump casing 138 of a circulation pump assembly 2 . With this arrangement shown in FIG. 8 , the exit sides of the two valves 120 and 122 do not run out into a common outlet 114 , as shown in FIGS. 5-7 , but directly into the suction chamber 140 in the inside of the pump casing 138 . The receiver for the valves 120 and 122 can thus be designed as one piece with the pump casing 138 . Such a design in particular is suitable for being integrated directly into a compact heating installation, in particular into the hydraulic block of such a compact heating installation. Thus the inlet 116 can directly form the return connection 24 for the room heating circuit, and the inlet 118 can be directly connected to the secondary heat exchanger 8 . [0088] FIGS. 9 and 10 show an alternative design to the arrangement according to FIG. 8 , and this differs from the arrangement shown in FIG. 8 only in that the inlet 118 is not directed to the rear side in a direction parallel to the rotation axis X of the circulation pump assembly, but laterally at an angle of 90 to the inlet 116 , so that both inlets 116 and 118 are directed at right angles to one another and at right angles to the rotation axis X of the circulation pump assembly. Such an arrangement, compared to the arrangement shown in FIG. 8 can be for example advantageous if a secondary heat exchanger 8 is not to be applied onto the pump casing 138 ′ at the rear side, but laterally. [0089] The preceding description with regard to FIGS. 2-7 is referred to with regard to the manner of functioning of the valves 120 and 122 which form the switch device, with the embodiments according to FIGS. 8-10 . [0090] In the previous embodiment examples, the valves 86 , 88 , 120 , 120 ′ and 122 are designed such that they are closed in their first switch position forming the idle position, and are moved in a targeted manner into an opened second switch position by way of the occurring hydraulic forces. However, it is to be understood that the valves can also be designed in the reverse manner and be opened in their first switch position forming the idle position. The valves can then be moved in a targeted manner into a second closed switch position by the occurring hydraulic forces which are created by the circulation pump assembly. Such an embodiment example is shown in FIG. 15 , which represents an alternative embodiment to the embodiment shown in FIG. 10 . With the embodiment according to FIG. 15 , valves 120 ″ and 122 ″ with valve elements 124 ″ and 128 ″ are shown, instead of the valves 120 and 122 , and these elements are held in their first switch position which in this case is an opened switch position, in each case by way of compression springs 134 and 136 , in the previously described manner. The valve elements 122 ″ and 124 ″, according to the previously description, can be brought in a targeted manner into a second switch position, in which they are closed, by way of a suitable activation of the circulation pump assembly 2 , on account of the different biasing forces and different dynamic characteristics. Thereby, the pin-like extensions 108 and 110 as previously described effect a mutual blocking of the valves 120 ″ and 122 ″. The functioning manner of the valves 120 ″ and 122 ″ thereby corresponds to the previously described manner of functioning of the valves 120 and 122 . The single difference lies in the fact that the valve elements 124 ″ and 128 ″ in the example shown in FIG. 15 are moved from an opened into a closed position instead of from a closed into an opened position. [0091] FIGS. 12 and 13 show an alternative arrangement of two valves corresponding to the valves 120 and 122 as have been described by way of FIGS. 5-10 . The valve 122 which releases or closes the flow path to the second hydraulic circuit B thereby corresponds to that of the preceding description. The valve 120 ′ which releases or closes the flow path to the first hydraulic circuit A, with regard to its damping function or delay function is designed differently than in the embodiment examples according to FIGS. 5-10 . [0092] The construction of the valve 120 ′ is shown in an enlarged manner in a sectioned view in FIG. 11 . The valve 120 ′ differs from the valve 120 in the construction of the valve element 124 ′ and of the valve seat 126 ′. FIG. 11 shows the closed switch position of the valve 120 ′. In this switch position, the valve element 124 ′ bears via a projection 142 on an inner side of the valve seat 126 ′. The inner side 144 is away from the inlet 116 . The projection 142 is situated on a radially outwardly projecting shoulder 146 of the valve element 124 ′. The projection 142 has the effect that the valve 120 ′ is not completely closed in this first position, but rather a radially outwardly directed annular gap 148 is formed between the shoulder 146 and the inner side 144 of the valve seat 126 ′. A radially outwardly directed flow is effected through this annular gap 148 , and this flow according to Bernoulli's law effects a force opposite to the opening direction v, onto the valve element 124 ′ at the shoulder 46 . This force is thus directed in the same direction as the spring force of the compression spring 134 . The fluid pressure acts upon the face side 150 of the valve element 124 ′, wherein the face side 150 represents a control surface. The hydraulic force which acts upon the control surface 150 is greater than the force of the compression spring 134 and the axial force arising in the annular gap 148 if the fluid pressure is large enough, so that the valve element 124 ′ is moved in the opening direction. Thereby, the gap width of the annular gap 148 enlarges so that the hydraulic force which is on the shoulder 146 and which is directed oppositely to the opening force is reduced. [0093] An annular surface 152 on the outer periphery of the valve element 124 ′ close to its face side 150 moves into the region of the inner periphery 154 of the valve seat 126 ′ during the continued movement of the valve element 124 ′ in the opening direction v. The annular surface 152 has a diameter which is the same or slightly smaller than the inner diameter of the inner periphery 154 . The valve 120 ′ is essentially closed when the annular surface 152 lies opposite the inner periphery 154 of the valve seat 126 ′. This closed position is shown in FIG. 13 . The valve 122 in this position is already opened due to the rapid pressure build-up, as described above, and then via its pin-like extension 110 blocks a further opening of the valve 120 ′ as described above. This is the first switch position of the switch device. The valve element 124 ′ moves further in the opening direction v if the continued movement is not blocked by the pin-like extension 110 of the valve element 128 , wherein the annular surface 152 passes the inner periphery 154 of the valve seat 126 ′, so that a gap is formed between the inner side 144 and the face side 150 of the valve element 124 ′, as is shown in FIG. 12 , and thus the valve 120 ′ is in its opened second position. As described above, in this position, the pin-like extension 108 of the valve element 124 ′ blocks the valve element 128 in its movement, so that this cannot move into its opened position. Via the valve 120 ′, the first hydraulic circuit A is then opened in this second switch position, whereas the second hydraulic circuit B is closed. [0094] Although the switching of the valves is effected by way of different speed increases concerning the previously described examples, it is to be understood that the valves can also be designed in a corresponding manner such that they are switched by way of differently rapid speed reductions. [0095] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

A hydraulic system includes at least one circulation pump assembly ( 2 ) provided with a speed controller ( 4, 26 ), at least one hydraulic circuit (A, B) connected to the circulation pump assembly ( 2 ) as well as at least one mechanical switch device ( 86, 88; 120, 122 ) which is mechanically subjected to pressure by a fluid in the hydraulic circuit (A, B) and which can be moved into at least two different switch positions. The mechanical switch device ( 86, 88; 120, 122 ) moves by the circulation pump assembly ( 2 ) hydraulic coupling via the fluid. The speed controller is configured to initiate a movement of the switch device ( 86, 88; 120, 122 ), by at least one hydraulic force acting upon the switch device ( 86, 88; 120, 122 ) and causing a movement of the switch device ( 86, 88; 120; 122 ) via the hydraulic circuit, via a speed adaptation of the circulation pump assembly ( 2 ).

RELATED APPLICATIONS This application claims priority under 35 U.S.C. sec. 119(e)(2) to U.S. Provisional Application No. 60/218,602, filed Jul. 17, 2000. This application is a continuation-in-part of the following application that is assigned to the common assignee of this application: “Method and System for Providing Dynamic Host Service Management Across Disparate Accounts/Sites”, Ser. No. 09/710,095, filed Nov. 10, 2000, now U.S. Pat. No. 6,816,905. This application is related to the following applications that are assigned to the common assignee of this application: “Scalable Internet Engine”, Ser. No. 09/709,820, filed Nov. 10, 2000, now U.S. Pat. No. 6,452,809; and “System for Distributing Requests Across Multiple Servers Using Dynamic Metrics”, Ser. No. 09/765,766, filed Jan. 18, 2001, now U.S. Pat. No. 6,938,256. FIELD OF THE INVENTION The present invention relates generally to the field of data processing business practices. More specifically, the present invention relates to a method and system for operating a commissioned e-commerce service provider that provides services to businesses on a computerized network such as the Internet in exchange for a small commission on the commercial transactions generated using those services. BACKGROUND OF THE INVENTION The explosive growth of the Internet as a computerized network has been driven to large extent by the emergence of commercial Internet Service Providers (ISPs). Commercial ISPs provide users with access to the Internet in the same way that telephone companies provide customers with access to the international telephone network. The vast majority of commercial ISPs charge for this access in ways similar to the ways in which telephone companies charge their customers. Originally, it was customary for an ISP to charge its users based on the time they were connected, just as telephone companies charge for long distance services. Now, most ISPs have adopted a flat monthly access rate that is similar to the way in which telephone companies charge for local telephone service. All of these charges are essentially metered charges where a fee is charged for access for a given period of time, i.e. so many cents per minute or so many dollars per month. There are many reasons for the similarities between the metered billing practices of ISPs and telephone companies. Both the computerized Internet network and international telephone network utilize the same backbone of high-speed, high bandwidth communication channels to carry voice and data traffic over long distances. A significant portion of the data traffic between users and ISPs also occurs over local telephone networks using dial-up modems. Many of the larger ISPs are divisions of, or affiliates of, telephone companies. Like telephone companies, ISPs may be subject to governmental regulation as common carriers or utilities. Perhaps most importantly, there are only a handful of firms that provide the backbone network connections required by an ISP and all of these firms utilize metered billing practices in charging for these carriage costs. Backbone network connection costs constitute a significant portion of the typical cost profile of an ISP, and, in the case of the non-North American ISP can constitute the vast majority of the cost profile of that provider. The details of how such metered billing arrangements for telephonic and network connections are accomplished have been the subject, for example, of U.S. Pat. Nos. 3,764,747, 5,187,710, 5,303,297, 5,351,286, 5,745,884, 5,828,737, 5,946,670, 5,956,391 and 5,956,697. For ISPs, numerous software billing packages are available to account and bill for these metered charges, such as XaCCT from rens.com and ISP Power from inovaware.com. Other software programs have been developed to aid in the management of ISP networks, such as IP Magic from lightspeedsystems.com, Internet Services Management from resonate.com and MAMBA from luminate.com. The management and operation of an ISP also has been the subject of numerous articles and seminars, such as Hursti, Jani, “Management of the Access Network and Service Provisioning,” Seminar in Internetworking , Apr. 19, 1999. An example of the offerings of a typical ISP at a given monthly rate in terms of available configurations of hardware, software, maintenance and support for providing commercial levels of Internet access and website hosting can be found at rackspace.com. The various factors involved in establishing pricing strategies for ISPs are discussed in detail by Geoff Huston in ISP Survival Guide: Strategies For Running A Competitive ISP , Chap. 13, pp. 497-535 (1999). He identifies five major attributes of the access service of an ISP that are folded into the retail tariff to be charged by that ISP, including access, time, volume, distance and quality. Where cost of service operations are greater than the carriage costs, it is typical to use a monthly flat rate access pricing because of the ease of implementation, simplicity, scalability and competitive environment for these providers. Where the carriage costs dominate, a monthly flat rate tariff may present an unacceptable business risk, and some form of incremental tariff structure based on more closely monitored metered usage may be preferred. Although Mr. Huston expects the ISP industry to stabilize and consolidate as larger players begin to dominate the industry, he notes that predictions of market stability within the Internet continue to be confounded by the experience of constant robust growth and evolution in service models. One such point of evolution has been the emergence of a small number of ISPs, such as netzero.com and freeInet.com which are providing their service for free to individual end users. Instead of charging an access fee or tariff, the business model for these ISPs relies on advertising revenue generated by banner ads that are constantly displayed on a user's screen during the time when the user is connected to the service. In many ways, this business model is similar to the business model of commercial broadcast television where the revenue generated by advertisements underwrites the costs of providing the service. Another offshoot from the services provided by conventional ISPs has been the growth of Application Systems Providers (ASPs) such as applicast.com and usi.net, as well as Enhanced or Enterprise Solution Providers (ESPs) such as cwusa.com and hostpro.net. Although there is no clear definition of the precise set of services provided by ASPs and ESPs, the business model is similar to the mainframe service bureau model practiced by Electronic Data Systems and others in which a defined portion of a companies computer processing needs are outsourced to a third party. ASPs and ESPs provide services tailored to meet some, most or all of a customer's needs with respect to application hosting, site development, e-commerce management and server deployment in exchange for a periodic fee. In the context of server deployment, the fees are customarily based on the particular hardware and software configurations that a customer will specify for hosting the customer's applications or web site. As with conventional ISPs, the more powerful the hardware and software and the more support services that are provided, the higher the monthly fee. Most of the patents to date related to Internet billing and ISPs have focused on providing a secure way of conducting transactions over the Internet by involving the ISP in the payment chain between an e-commerce merchant and a purchaser that is a user of the ISP. Examples of these secured payment systems involving an ISP are shown in U.S. Pat. Nos. 5,794,221, 5,845,267 and 5,899,980. While these kinds of payment systems may be used in a limited capacity, the widespread acceptance of transacting purchases over the Internet using credit card information provided over a secured server link has surpassed most of the need for these kind of systems. U.S. Pat. No. 5,819,092 describes an online development software tool with fee setting capabilities that allows the developer of a web site, for example, to develop a fee structure for an online service where fees can be levied against both users and third parties in response to logging onto an online service, performing searches or downloading information. U.S. Pat. No. 6,035,281 describes a system for multiparty billing for Internet access where participating parties are allocated a share of the billing based on a predetermined function of the content accessed and the bandwidth used during the access. While there continues to be a subset of Internet access that operates on a “pay-per-view” basis, much of the need for these kind of accounting tools has diminished as the trend is to make the vast majority of information accessed over the Internet available free of such pay-per-view charges. European Patent Appl. No. 0 844 577 A3 describes a multi-level marketing computer network server where upon the completion of a transaction at the server, the server generates multi-level marketing commission payments due to “participants” in the multi-level marketing program as a result of the sale. While this application describes the use of a network server, the focus of this application is not on the way in which an ISP would be operated, but rather represents the automation of a conventional multi-level marketing arrangement where commissions are paid to a series of individuals within the multi-level marketing organization for each sale. Although numerous enhancements and improvements have been made in terms of the way that ISPs are managed and many programs and tools have been developed to aid in the operation of ISP networks, the basic way in which ISPs charge for their services has not changed since the Internet become a predominantly commercial network. SUMMARY OF THE INVENTION The present invention is a method for operating a commissioned e-commerce service provider that provides services to businesses on a computerized network such as the Internet in exchange for a small commission on the commercial transactions generated using those services. Unlike most ISPs that provide services to individuals and businesses, the commissioned e-commerce service provider preferably provides Internet services for businesses operating web sites or other application that generate e-commerce transactions for the business. Instead of paying a monthly fee for the Internet services required to host a web site or operate and e-commerce site, the business contracts with the commissioned e-commerce service provider to provide these services based on receiving a percentage commission of the commercial transactions generated using these services. The commission percentage is tiered in accordance with the amount of traffic at the site to provide a nominal level of service at a lower commission rate, yet allow for an exceptional volume of traffic to be accommodated by the site at a higher commission rate without having the site fail or the service become overwhelmed. In this way, a business is not locked into a given capacity of service based the specific amount of hardware, for example, that was purchased by their agreement with the ISP. Instead, the commissioned e-commerce service provider allocates servers and resources on an as-needed basis to the web sites and applications of the business in response to the immediate demand for Internet access to those web sites and applications. In addition, it is not necessary for the business to waste scarce financial resources by scaling its service capacity in order to handle a small number of peak access times. In a preferred embodiment, the base tier of the commission percentage is established in relation to the anticipated or actual average usage of services as measured against the volume of commercial transactions during this average usage. A second tier of the commission percentage is defined at a predetermined increase above the base tier in the event that immediate usage exceeds a first predefined level above the average usage. A third tier of the commission percentage is defined at a predetermined increase above the second tier in the event that immediate usage exceeds a second predefined level above the average usage. Preferably, average usage is a combined measure of the number of simultaneous access requests and the amount of access bandwidth required to satisfy those requests prior to a timeout of the request by a user. In a preferred embodiment, the CESP is hosted by an Internet engine that is operably connected to the Internet to provide a data center and other related host server management services to Internet account or site customers, who in turn pay a fee for these services that is at least partially based on at least one attribute related to host server services use. A customer benefits from the business method because the commission part of the fee is based on at least one attribute related to host server services usage rather than being a fixed fee charged “by the box” (by the server unit), bandwidth, or square footage of space used. This flexibility allows host server management services to be offered to customers in a manner more analogous to other like services to which the customers are accustomed, or in a manner that can nearly approximate billing methods already used by the host server management services provider or an affiliate. If desirable, for example, a service agreement can be structured according to a customer's unique requirements and billing structure, such as invoicing based on the number of hits, number of connections, number of transactions, revenue from transactions, or a combination of these models. Under this business method, the host server management services provider carries the risk of the services so that the customer can focus on marketing its content. Preferrably, the host server management services provider guarantees a certain maximum user level or capability to customers, which the host server management services provider is responsible for meeting regardless of the resources required. This guarantee, incorporated into a service agreement, significantly assists customers such as .coms, B2B emporiums, and service bureaus, among others, in running massive advertising campaigns and to offer advanced services without fearing that they will run out of compute capacity. MP3 sites can offer the latest titles, and DVD sites, for example, can stream titles knowing that sufficient resources will be available to handle peak demands without the need for the customer to oversubscribe to a given number of server boxes as would otherwise be necessary under conventional pricing arrangements for hosted services. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified block diagram of a prior art arrangement of a server farm for a hosted service provider. FIG. 2 is a graphic representation of Internet traffic in relation to server capacity for a prior art server farm hosting multiple customer accounts. FIG. 3 is a simplified block diagram of the arrangement of a server farm in accordance with the present invention. FIG. 4 is a simplified block diagram similar to FIG. 3 showing the dynamic reallocation of servers from a first customer account to a second customer account to address a hardware failure. FIG. 5 is a simplified block diagram similar to FIG. 3 showing the dynamic reallocation of servers from a first customer account to a second customer account to address an increased usage demand. FIG. 6 is a block diagram of a preferred embodiment of the components of a server farm in accordance with the present invention. FIG. 7 is an exploded perspective view of a preferred embodiment of the hardware for the server farm in accordance with the present invention. FIG. 8 is a block diagram showing the hierarchical relation of the various software layers utilized by the present invention for a given customer account. FIG. 9 is a block diagram of an embodiment of the present invention implemented across geographically disparate sites. FIG. 10 is a graphic representation of Internet traffic in relation to server capacity for the server farm of the present invention when hosting multiple customer accounts. FIG. 11 is a block diagram showing a preferred embodiment of the master decision software program of the present invention. FIG. 12 is a graphic representation of three different service level agreement arrangements for a given customer account. FIG. 13 is a graphic representation of Internet traffic in relation to server capacity for a multi-site embodiment of the present invention. FIG. 14 is a block diagram showing the master decision software program controlling the network switch and storage unit connections. FIG. 15 is a block diagram of the preferred embodiment of the local decision software program. FIG. 16 is a graphic representation of the workload measurements from the various measurement modules of the local decision software program under varying load conditions. FIG. 17 is a graphic representation of a decision surface generated by the local decision software program to request or remove a server from an administrative group. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 , a simplified functional view of an existing server farm 20 for a hosted service provider is shown. Such server farms are normally constructed using off-the-shelf hardware and software components statically configured to support the hosted service requirements of a given customer account. In this embodiment, the server farm 20 for the hosted server provider is supporting hosted services for four different customer accounts. The server farm 20 is connected to the Internet 22 by network switches/routers 24 . The network switches 24 are in turn connected to internal network switches/routers 26 that form an intranet among the front-end/content servers 28 and back-end/compute servers 30 for a given customer account. All front-end/content servers 28 and back-end/compute servers 30 are connected to disk systems 32 containing data and software unique to that customer account. Depending upon the physical nature of the hardware for the servers 28 , 30 , the disk systems 32 may be included within the server housing, or the disk systems 32 may be housed in physically separate units directly connected to each of the servers 28 , 30 or attached to more than one server 28 , 30 as a storage attached network (SAN) or network attached storage (NAS) configuration. While this arrangement makes good use of off-the-shelf hardware to construct a server farm 20 that can provide hosted services for multiple independent customer accounts, there are several significant issues exposed in this type of an arrangement. The most significant of these is the generally static nature of the allocation and deployment of system resources among different customer accounts. In order to configure and manage a single customer account within this complex, an administrator for the HSP needs to dedicate some fixed level of system resources (e.g., servers, disks, network links) to the particular customer account based on projected requirements of that customer's needs. For example, assume a relatively simple website has been designed for any given customer account such that under a projected peak load the customer account may require three front-end servers 28 to handle user requests and a quad processor back-end server 30 to handle database queries/updates generated by these requests. For this type of website, it is likely that hardware-based technology such as F5 Big-IP, Cisco Local Director, or Foundry ServerIron, or a software-based solution such as Windows Load Balance Service (WLBS) or equivalent will be used to distribute the user requests evenly across the front-end/content servers 28 . In addition, the back-end database/compute server 30 will commonly be clustered to provide some level of fault tolerance. There are a number of software products available, such as Microsoft Cluster Server, Oracle Parallel Server, etc., that allow websites with multiple servers to ride through hardware failures that might occur during normal operation. In addition, system monitoring tools such as Tivoli Enterprise, HP OpenView, etc. allow administrators to be notified when failures are detected within the server farm 20 . Although these tools can be adequate for managing the hosted services within a single customer account at a given site, none of these tools allow for the management of hosted services across disparate customer accounts. In the context of this example, assume that the website for this customer account is an e-commerce site designed to handle a peak load of 5000 transactions per minute. Further, assume that the websites for the remaining customer accounts in the server farm 20 have been designed to handle peak loads of 10,000, 15,000 and 5000 transactions per minute, respectively. As shown in FIG. 2 , having to design and configure each customer account to handle an anticipated peak load likely results in significant wasted capacity within the overall server farm 20 . Even though the server farm 20 handling multiple customer accounts may have excess aggregate capacity, this extra capacity cannot be used to respond to hardware failures or unexpected increases in peak load from one account to the next. Resources configured for a particular customer account are dedicated to that account and to that account only. In the event that one of the front-end servers 28 for a first customer account experiences a hardware failure, Web traffic will be routed to the remaining front-end servers 28 . If the customer account was busy before the hardware failure and Web traffic remains constant or increases after the failure, the remaining front-end servers 28 will quickly become overloaded by servicing their previous workload as well as the additional traffic redirected from the failed server. In a best case scenario, the system management software for the server farm 20 would notice that a server had failed and send a message to a site manager (via pager and/or e-mail) indicating the server failure. If the site manager receives the message in a timely manner and is located on site, the site manager can physically remove the failed hardware component, install a spare hardware component that has hopefully been stockpiled for this purpose, recable the new hardware component, configure and install the appropriate software for that customer account, and allow the new hardware component to rejoin the remaining front-end servers 28 . Hopefully, this process could be accomplished in less than an hour. If the message is not received in a timely manner, if the site manager is not located at the site where the server farm is located, or if there is no stockpiled spare hardware available to replace the failed unit, this process will take even longer. In the meantime, response times for users accessing the customer account are degraded and the customer account becomes increasingly vulnerable to another hardware failure during this period. In the event that the customer account experiences an increase in demand above the anticipated peak demand for which that customer account has been configured, there are no resources available to the load balancing facilities for redistributing this increased Web traffic. All of the servers 28 , 30 would be operating at peak capacity. The result is significantly degraded response times for the customer account and a possibility of “service unavailable” responses for requests that cannot be handled in a timely manner. While the inability to provide services to consumers in a timely manner is an undesirable, but perhaps manageable, problem for a business in other contexts, the additional problem of generating “service unavailable” messages for a website is that, if such messages continue to persist for whatever reason, the Internet may begin to propagate this information to numerous intermediary nodes in the network. As a result, these intermediary nodes will divert subsequent requests to the website due to their understanding that the website is “unavailable”. Not only are the consumers who receive the “service unavailable” message not serviced, but many other consumers may never even get to the website once the customer account becomes saturated or overloaded. Referring now to FIG. 3 , a server farm 40 for providing dynamic management of hosted services to multiple customer accounts will be described. As with existing server farms 20 , the server farm 40 includes network switches 44 to establish interconnection between the server farm 40 and the Internet 22 . Unlike existing server farm 20 , however, a population of servers 46 are managed under control of an engine group manager 48 . Each of the servers 46 is a stateless computing device that is programatically connected to the Internet via the network switches 44 and to a disk storage system 50 . In one embodiment, the servers 46 are connected to the disk storage system 50 via a Fibre Channel storage area network (SAN). Alternatively, the servers 46 may be connected to the disk storage system 50 via a network attached storage (NAS) arrangement, a switchable crossbar arrangement or any similar interconnection technique. As shown in FIGS. 4 and 5 , the engine group manager 48 is responsible for automatically allocating the stateless servers 46 among multiple customer accounts and then configuring those servers for the allocated account. This is done by allocating the servers for a given customer account to a common administrative group 52 defined for that customer account and configured to access software and data unique to that customer account. As will be described, the engine group manager 48 automatically monitors each administrative group and automatically and dynamically reallocates servers 46 ′ from a first administrative group 52 - a to a second administrative group 52 - b in response to the automatic monitoring. This is accomplished by using the engine group manager 48 to set initialization pointers for the reallocated servers 46 ′ from the first administrative group 52 - a to access software and data unique to the customer account for the second administrative group 52 - b , and then reinitializing the reallocated servers 46 ′ such that reallocated servers 46 ′ join the second administrative group 52 - b . Unlike the existing process for adding are removing hardware resources to a server farm 20 , the present invention can make a reallocated server 46 ′ available to a new administrative group 52 in as little as a few minutes. Basically, the only significant time required to bring the reallocated server 46 ′ online will be the time required to reboot the server 46 ′ and any time required for the load-balancing and/or clustering software to recognize this rebooted server. It will be understood that load-balancing software is more typically found in connection with front-end/content servers, whereas clustering software or a combination of clustering software and load-balancing software are more typically used in connection with back-end/compute servers. The term load-balancing software will be used to refer to any of these possible combinations. In one embodiment, the reallocated servers 46 ′ automatically join the second administrative group because the software for the second administrative group 52 - b includes load-balancing software that will automatically add or remove a server from that administrative group in response to the server being brought online (i.e. reset and powered on) or brought offline (i.e., reset and powered off). As previously described, this kind of load-balancing software is widely known and available today; however, existing load-balancing software is only capable of adding or removing servers from a single administrative group. In this embodiment, the engine group manager 48 takes advantage of capabilities of currently available commercial load-balancing application software to allow for the dynamic reallocation servers 46 ′ across different administrative groups 52 . Alternatively, agents or subroutines within the operating system software for the single administrative group could be responsible for integrating a reallocated server 46 ′ into the second administrative group 52 - b once the reallocated server 46 ′ is brought online. In still another embodiment, the engine group manager 48 could publish updates to a listing of available servers for each administrative group 52 . Preferably, the engine group manager 48 will set pointers in each of the servers 46 for an administrative group 52 to an appropriate copy of the boot image software and configuration files, including operating system an application programs, that had been established for that administrative group 52 . When a reallocated server 46 ′ is rebooted, its pointers have been reset by the engine group manager 48 to point to the boot image software and configuration files for the second administrative group 52 - b , instead of the boot image software and configuration files for the first administrative group 52 - a. In general, each administrative group 52 represents the website or similar hosted services being provided by the server farm 40 for a unique customer account. Although different customer accounts could be paid for by the same business or by a related commercial entity, it will be understood that the data and software associated with a given customer account, and therefore with a given administrative group 52 , will be unique to that customer account. Unlike service providers which utilize large mainframe computer installations to provide hosted services to multiple customers by using a single common operating system to implement timesharing of the resources of the large mainframe computer system, each administrative group 52 consists of unique software, including conventional operating system software, that does not extend outside servers 46 which have been assigned to the administrative group 52 . This distributed approach of the present invention allows for the use of simpler, conventional software applications and operating systems that can be installed on relatively inexpensive, individual servers. In this way, the individual elements that make up an administrative group 52 can be comprised of relatively inexpensive commercially available hardware servers and standard software programs. FIGS. 6 and 7 show a preferred embodiment of the components and hardware for the server farm 40 in accordance with the present invention. Although the preferred embodiment of the present invention is described with respect to this hardware, it will be understood that the concept of the present invention is equally applicable to a server farm implemented using all conventional servers, including the currently available 1U or 2U packaged servers, if those servers are provided with the host management circuitry or its equivalent as will be described. Preferably, the hardware for the server farm 40 is a scalable engine 100 comprised of a large number of commercially available server boards 102 each arranged as an engine blade 132 in a power and space efficient cabinet 110 . The engine blades 132 are removably positioned in a front side 112 of the cabinet 110 in a vertical orientation. A through plane 130 in the middle of the cabinet 110 provides common power and controls peripheral signals to all engine blades 132 . I/O signals for each engine blade 132 are routed through apertures in the through plane 130 to interface cards 134 positioned in the rear of the cabinet 110 . The I/O signals will be routed through an appropriate interface card 134 either to the Internet 22 via the network switch 44 , or to the disk storage 50 . Preferably, separate interface cards 134 are used for these different communication paths. The scalable engine can accommodate different types of server boards 102 in the same cabinet 110 because of a common blade carrier structure 103 . Different types of commercially available motherboards 102 are mounted in the common blade carrier structure 103 that provides a uniform mechanical interface to the cabinet 110 . A specially designed PCI host board 104 that can plug into various types of motherboards 102 has connections routed through the through plane 130 for connecting to the interface cards 134 . Redundant hot-swappable high-efficiency power supplies 144 are connected to the common power signals on the through plane 130 . The host board 104 includes management circuitry that distributes the power signals to the server board 102 for that engine blade 132 by emulating the ATX power management protocol. Replaceable fan trays 140 are mounted below the engine blades 132 to cool the engine 100 . Preferably, the cabinet 110 accommodates multiple rows of engine blades 132 in a chassis assembly 128 that includes a pair of sub-chassis 129 stacked on top of each other and positioned on top of a power frame 146 that holds the power supplies 144 . Preferably, the cabinet 110 will also include rack mounted Ethernet networks switches 44 and 147 and storage switches 149 attached to disk drives 50 over a Fibre Channel network. For a more detailed description of the scalable engine 100 of the preferred embodiment of the present invention, reference is made to the previously-identified, co-pending application entitled “Scalable Internet Engine,” the disclosure of which is hereby incorporated by reference. It will also be understood that while the present invention is described with respect to single cabinet 110 housing engine blades 132 with server boards 102 that together with the appropriate application software constitute the various servers 46 that are assigned to a first administrative group 52 - a , and a second administrative group 52 - b each having at least two engine blades 132 , the server farm 40 can accommodate administrative groups 52 for any number of customers depending upon the total number of servers 46 in the server farm 40 . Preferably, multiple cabinets 110 can be integrated together to scale the total number of servers 46 at a given location. As will be discussed, it is also possible to link multiple cabinets 110 in geographically disparate locations together as part of a single server farm 40 operating under control of the engine group manager 48 . In the preferred embodiment, the server boards 102 of each engine blade 132 can be populated with the most recent processors for Intel, SPARC or PowerPC designs, each of which can support standard operating system environments such as Windows NT, Windows 2000, Linux or Solaris. Each engine blade 132 can accommodate one or more server boards 102 , and each server board may be either a single or multiprocessor design in accordance with the current ATX form factor or a new form factor that may be embraced by the industry in the future. Preferably, the communication channel 106 is implemented a Controller Area Network (CAN) bus that is separate from the communication paths for the network switch 44 or storage switches 149 . Optionally, a second fault backup communication channel 106 ′ could be provided to allow for fault tolerance and redundant communication paths for the group manager software 48 . In a conventional server, the pointers and startup configuration information would be set by manual switches on the server board or hardcoded into PROM chipsets on the server board or stored at fixed locations on a local hard drive accessible by the server board. The management circuitry on the host board 104 is designed to have appropriate hooks into the server board 102 such that the pointers and other startup configuration information are actually supplied by the host management circuitry. Optionally, an engine blade 132 can include a local hard drive 107 that is accessed through the host board 104 such that information stored on that local hard drive 107 can be configured by the host board via the communication channel 106 . Additionally, the host board 104 preferably includes power management circuitry 108 that enables the use of common power supplies for the cabinet 110 by emulating the ATX power management sequence to control the application of power to the server board 102 . Preferably, a back channel Ethernet switch 147 also allows for communication of application and data information among the various server boards 102 within the server farm 40 without the need to route those communications out over the Internet 22 . In a preferred embodiment, each cabinet 110 can house up to 32 engine blades 132 . In this configuration, the networks switches 44 and 147 could comprise two 32 circuit switched Ethernet network routers from Foundry. Preferably, the networks switches 44 and 147 allow a reconfiguration of the connection between a server 46 and the networks switch 44 and 147 to be dynamically adjusted by changing the IP address for the server. With respect to the disk storage units 50 , two options are available. First, unique hardware and software can be inserted in the form of a crossbar switch 149 between the engine blades 132 and the disk storage units 50 which would abstract way the details of the underlying SAN storage hardware configuration. In this case, the link between the disk storage units 50 and each blade 132 would be communicated to the crossbar switch 149 through set of software APIs. Alternatively, commercially available Fibre Channel switches or RAID storage boxes could be used to build connectivity dynamically between the blades 132 and disk storage units 50 . In both alternatives, a layer of software inside the engine group manager 48 performs the necessary configuration adjustments to the connections between the server blades 132 and networks switches 147 and disk storage units 50 are accomplished. In another embodiment, a portion of the servers 46 could be permanently cabled to the network switches or disk storage units to decrease switch costs if, for example, the set of customer accounts supported by a given portion of the server farm 40 will always include a base number of servers 46 that cannot be reallocated. In this case, the base number of servers 46 for each administrative group 52 could be permanently cabled to the associated network switch 149 and disk storage unit 50 for that administrative group 52 . Referring again to FIGS. 4 and 5 , it will be seen that the server farm system 40 of the present invention can dynamically manage hosted services provided to multiple customer accounts. It will be seen that there are at least five servers 46 operably connected to an intranet 54 . Preferably, the intranet is formed over the same network switches 44 that interconnect the servers 46 with the Internet 22 or over similar network switches such as network switches 147 that interconnect the servers 46 to each other. Each server 46 has management circuitry on the host board 104 that provides a communication channel 106 with at least one of the other servers 46 that is separate from the intranet 54 created by the network switches 44 and/or 147 . At least four of the servers 46 are configured to execute a local decision software program 70 that monitors the server 46 and communicate status information across the communication channel 106 . At least two of these servers 46 are allocated to a first administrative group 52 - a for a first customer account and configured to access software and data unique to the first customer account to provide hosted services to the Internet for that customer account. At least another two of the servers 46 are allocated to a second administrative group 52 - b for a second customer account and configured to access software and data unique to the second customer account to provide hosted services to the Internet for that customer account. At least one of the servers 46 executes a master decision software program 72 that collects status information from the local decision software programs 70 executing on the other servers 46 . In one embodiment, a pair of servers 46 are slaved together using fault tolerant coordination software to form a fault tolerant/redundant processing platform for the master decision software program. As will be described, the master decision software program 72 dynamically reallocates at least one server 46 ′ from the first administrative group 52 - a to the second administrative group 52 - b in response to at least the status information collected from the local decision software programs 70 . The servers 46 for both administrative groups 52 can be arranged in any configuration specified for a given customer account. As shown in FIG. 3 , three of the servers 46 for administrative group 52 - b are configured as front-end servers with a single server 46 being configured as the back-end/compute server for this customer account. In response to a significant increase in the peak usage activity for the customer account for the second administrative group 52 - b , the master decision software program 72 determines that is necessary to reallocate server 46 ′ from its current usage as a server for the first administrative group 52 - a to being used as a back-end/compute server for the second administrative group 52 - b . The preferred embodiment for how this decision is arrived will be described in connection with the description of the operation of the local decision software program 72 . Following the procedure just described, the master decision software program 72 directs the dynamic reallocation of reallocated server 46 ′ to the second administrative group 52 - b as shown in FIG. 4 . Although the preferred embodiment of present invention is described in terms of reallocation of a server 46 ′ from a first administrative group 52 - a to a second administrative group 52 - b , it should be understood that the present invention can also be implemented to provide for a common pool of available servers 46 ′ that are not currently assigned to a given administrative group 52 and may be reallocated without necessarily requiring that they be withdrawn from a working administrative group 52 . For example, a server farm 40 having thirty-two servers 46 could be set up to allocate six servers to each of four different customer accounts, with one server 46 executing the master decision software program 72 and a remaining pool 56 of seven servers 46 that are initially unassigned and can be allocated to any of the four administrative groups 52 defined for that server farm. Because the assignment of servers to administrative groups is dynamic during the ongoing operation of the server farm 40 in accordance with the present invention, the preferred embodiment of the present invention uses this pool 56 as a buffer to further reduce the time required to bring a reallocated server 46 ′ into an administrative group 52 by eliminating the need to first remove the reallocated server 46 ′ from its existing administrative group 52 . In one embodiment, the pool 56 can have both warm servers and cold servers. A warm server would be a server 46 that has already been configured for a particular administrative group 52 and therefore it is not necessary to reboot that warm server to allow it to join the administrative group. A cold server would be a server that is not configured to a particular administrative group 52 and therefore it will be necessary to reboot that cold server in order for it to join the administrative group. It should also be understood that reallocated servers 46 ′ can be allocated to a new administrative group singly or as a group with more than one reallocated server 46 ′ being simultaneously reallocated from a first administrative group 52 - a to a second administrative group 52 - b . In the context of how the network switches 44 , 147 and storage switches 149 are configured to accommodate such dynamic reallocation, it should also be understood that multiple servers 46 may be reallocated together as a group if it is necessary or desirable to reduce the number of dynamically configurable ports on the network 44 , 147 and/or storage switches 149 . One of the significant advantages of the present invention is that the process of reconfiguring servers from one administrative group 52 - a to a second administrative group 52 - b will wipe clean all of the state associated with a particular customer account for the first administrative group from the reallocated server 46 ′ before that server is brought into service as part of the second administrative group 52 - b . This provides a natural and very efficient security mechanism for precluding intentional or unintentional access to data between different customer accounts. Unless a server 46 or 46 ′ is a member of a given administrative group 52 - a , there is no way for that server to have access to the data or information for a different administrative group 52 - b . Instead of the complex and potentially problematic software security features that must be implemented in a mainframe server or other larger server system that utilizes a shard memory space and/or common operating system to provide hosted services across different customer accounts, the present invention keeps the advantages of the simple physical separation between customer accounts that is found in conventional server farm arrangements, but does this while still allowing hardware to be automatically and dynamically reconfigured in the event of a need or opportunity to make better usage of that hardware. The only point of access for authorization and control of this reconfiguration is via the master decision software program 72 over the out-of-band communication channel 106 . As shown in FIG. 14 , preferably each server 46 is programmatically connected to the Internet 22 under control of the master decision software program 72 . The master decision software program 72 also switches the reallocated server 46 ′ to be operably connected to a portion of the disk storage unit storing software and data unique to the customer account of the second administrative group. The use of an out-of-band communication channel 106 separate from the intranet 54 over the network switches 44 for communicating at least a portion of the status information utilized by the master decision software program 72 is preferably done for reasons of security, fault isolation and bandwidth isolation. In a preferred embodiment, the communication channel 106 is a serial Controller Area Network (CAN) bus operating at a bandwidth of 1 Mb/s within the cabinet 106 , with a secondary backbone also operating at a bandwidth 1 Mb/s between different cabinets 106 . It will be understood that a separate intranet with communications using Internet Protocol (IP) protocol could be used for the communication channel 106 instead of a serial management interface such as the CAN bus, although such an embodiment would effectively be over designed for the level and complexity of communications that are required of the communication channel 106 connected to the host boards 104 . While it would be possible to implement the communication channel 106 as part of the intranet 54 , such an implementation is not preferred because of reasons of security, fault isolation and bandwidth isolation. FIG. 8 shows a block diagram of the hierarchical relation of one embodiment of the various data and software layers utilized by the present invention for a given customer account. Customer data and databases 60 form the base layer of this hierarchy. Optionally, a web data management software layer 62 may be incorporated to manage the customer data 60 across multiple instances of storage units that comprise the storage system 50 . Cluster and/or load-balancing aware application software 64 comprises the top layer of what is conventionally thought of as the software and data for the customer's website. Load-balancing software 66 groups multiple servers 46 together as part of the common administrative group 52 . Multiple instances of conventional operating system software 68 are present, one for each server 46 . Alternatively, the load-balancing software 66 and operating system software 68 may be integrated as part of a common software package within a single administrative group 52 . For a more detailed description of one embodiment of a load balancing system that may be utilized, reference is made to the previously-identified, co-pending application entitled “System for Distributing Requests Across Multiple Servers Using Dynamic Metrics,” the disclosure of which is hereby incorporated by reference. Above the conventional operating system software 68 is the engine operating software 48 of the present invention that manages resources across multiple customer accounts 52 - a and 52 - b. In one embodiment of the present invention as shown in FIG. 9 the servers 46 assigned to the first administrative group 52 - a are located at a first site 80 and the servers 46 assigned to the second administrative group 52 - b are located at a second site 82 geographically remote from the first site 80 . In this embodiment, the system further includes an arrangement for automatically replicating at least data for the first administrative group 52 - a to the second site 82 . In a preferred embodiment, a communication channel 84 separate from the network switches 44 is used to replicate data from the disk storage units 50 - a at the first site 80 to the disk storage units 50 - b at the second site 82 . The purpose of this arrangement is twofold. First, replication of the data provides redundancy and backup protection that allows for disaster recovery in the event of a disaster at the first site 80 . Second, replication of the data at the second site 82 allows the present invention to include the servers 46 located in the second site 82 in the pool of available servers which the master decision software program 72 may use to satisfy increased demand for the hosted services of the first customer by dynamically reallocating these servers to the first administrative group 52 - a. The coordination between master decision software programs 72 at the first site 80 and second site 82 is preferably accomplished by the use of a global decision software routine 86 that communicates with the master decision software program 72 at each site. This modular arrangement allows the master decision software programs 72 to focus on managing the server resources at a given site and extends the concept of having each site 80 , 82 request additional off-site services from the global decision software routine 86 or offer to make available off-site services in much the same way that the local decision software programs 70 make requests for additional servers or make servers available for reallocation to the master decision software program 70 at a given site. Preferably, the multi-site embodiment of the present invention utilizes commercially available SAN or NAS storage networking software to implement a two-tiered data redundancy and replication hierarchy. As shown in FIG. 9 , the working version 74 of the customer data for the first customer account customer is maintained on the disk storage unit 50 at the first site 80 . Redundancy data protection, such as data mirroring, data shadowing or RAID data protection is used to establish a backup version 76 of the customer data for the first customer account at the first site 80 . The networking software utilizes the communication channel 84 to generate a second backup version 78 of the customer data for the first customer account located at the second site 82 . The use of a communication channel 84 that is separate from the connection of the networks switches 44 to the Internet 22 preferably allows for redundant communication paths and minimizes the impact of the background communication activity necessary to generate the second backup version 78 . Alternatively, the backup version 78 of the customer data for the first customer account located at the second site 82 could be routed through the network switches 44 and the Internet 22 . In another embodiment, additional backup versions of the customer data could be replicated at additional site locations to further expand the capability of the system to dynamically reallocate servers from customer accounts that are underutilizing these resources to customer accounts in need of these resources. As shown in FIG. 10 , the ability of the present invention to dynamically reallocate servers from customer accounts that are underutilizing these resources to customer accounts in need of these resources allows for the resources of the server farm 40 to be used more efficiently in providing hosted services to multiple customer accounts. For each of the customer accounts 91 , 92 , 93 , 94 and 95 , the overall allocation of servers 46 to each customer account is accomplished such that a relatively constant marginal overcapacity bandwidth is maintained for each customer account. Unlike existing server farms, where changes in hardware resources allocated to a given customer account happen in terms of hours, days or weeks, the present invention allows for up-to-the-minute changes in server resources that are dynamically allocated on an as needed basis. FIG. 10 also shows the advantages of utilizing multiple geographically distinct sites for locating portions of the server farm 40 . It can be seen that the peak usages for customer accounts 94 and 95 are time shifted from those of the other customer accounts 91 , 92 and 93 due to the difference in time zones between site location 80 and site location 82 . The present invention can take advantage of these time shifted differences in peak usages to allocate rolling server capacity to site locations during a time period of peak usage from other site locations which are experiencing a lull in activity. In one embodiment of the multi-site configuration of the present invention as shown in FIG. 13 , at least three separate three separate site locations 80 , 82 and 84 are preferably situated geographically at least 24 divided by N+1 hours apart from each other, where N represents the number of distinct site locations in the multi-site configuration. In the embodiment having three separate site locations 80 , 82 and 84 , the site locations are preferably eight hours apart from each other. The time difference realized by this geographic separation allows for the usage patterns of customer accounts located at all three sites to be aggregated and serviced by a combined number of servers that is significantly less than would otherwise be required if each of the servers at a given location were not able to utilize servers dynamically reallocated from one or more of the other locations. The advantage of this can be seen when site location 80 is experiencing nighttime usage levels, servers from this site location 80 can be dynamically reallocated to site location 82 that is experiencing daytime usage levels. At the same time, site location 84 experiences evening usage levels and may or may not be suited to have servers reallocated from this location to another location or vice versa. Generally, a site location is arranged so as to look to borrow capacity first from a site location that is at a later time zone (i.e., to the east of that site) and will look to make extra capacity available to site locations that are at an earlier time zone (i.e., to the west of that site). Other preferences can also be established depending upon past usage and predicted patterns of use. Referring now to FIG. 11 , a preferred embodiment of the master decision software program 72 will be described. The master decision software program 72 includes a resource database 150 , a service level agreement database 152 , a master decision logic module 154 and a dispatch module 156 . The master decision logic module 154 has access to the resource database 150 and the service level agreement database 152 and compares the status information to information in the resource database 150 and the service level agreement database 152 to determine whether to dynamically reallocate servers from the first customer account to the second customer account. The dispatch module 156 is operably linked to the master decision logic module 154 to dynamically reallocate servers when directed by the master decision logic module 154 by using the communication channel 106 to set initialization pointers for the reallocated servers 46 ′ to access software and data unique to the customer account for the second administrative group 52 - b and reinitializing the reallocated server 46 ′ such that at least one server joins the second administrative group 52 - b . Preferably, the dispatch module 156 includes a set of connectivity rules 160 and a set of personality modules 162 for each server 46 . The connectivity rules 160 providing instructions for connecting a particular server 46 to a given network switch 44 or data storage unit 50 . The personality module 162 describes the details of the particular software configuration of the server board 102 to be added to an administrative work group for a customer account. Once the dispatch module 146 has determined the need to reallocate a server, it will evaluate the set of connectivity rules 160 and a set of personality modules 162 to determine how to construct a server 46 that will be dispatched to that particular administrative group 52 . Another way of looking at how the present invention can dynamically provide hosted service across disparate accounts is to view a portion of the servers 46 as being assigned to a pool of a plurality of virtual servers that may be selectively configured to access software and data for a particular administrative group 52 . When the dispatch module 146 has determined a need to add a server 46 to a particular administrative group 52 , it automatically allocates one of the servers from the pool of virtual servers to that administrative group. Conversely, if the dispatch module determines that an administrative group can relinquish one of its servers 46 , that relinquished server would be added to the pool of virtual servers that are available for reallocation to a different administrative group. When the present invention is viewed from this perspective, it will be seen that the group manager software 48 operates to “manufacture” or create one or more virtual servers out of this pool of the plurality of virtual servers on a just-in-time or as-needed basis. As previously described, the pool of virtual servers can either be a warm pool or a cold pool, or any combination thereof. The virtual server is manufactured or constructed to be utilized by the desired administrative group in accordance with the set of connectivity rules 160 and personality modules 162 . In this embodiment, the master decision logic module 152 is operably connected to a management console 158 that can display information about the master decision software program and accept account maintenance and update information to processes into the various databases. A billing software module 160 is integrated into the engine group manager 48 in order to keep track of the billing based on the allocation of servers to a given customer account. Preferably, a customer account is billed a higher rate at a higher rate for the hosted services when servers are dynamically reallocated to that customer account based on the customer's service level agreement. FIG. 12 shows a representation of three different service level agreement arrangements for a given customer account. In this embodiment, the service level agreements are made for providing hosted services for a given period of time, such as a month. In a first level shown at 170 , the customer account is provided with the capacity to support hosted services for 640,000 simultaneous connections. If the customer account did not need a reallocation of servers to support capacity greater than the committed capacity for the first level 170 , the customer would be charged to establish rate for that level of committed capacity. In a second level shown at 172 , customer account can be dynamically expanded to support capacity of double the capacity at the first level 172 . In a preferred embodiment, once the engine group manager 48 has dynamically reallocated servers to the customer account in order to support the second level 172 of capacity to meet a higher than anticipated peak usage, the customer account would be charged a higher rate for the period of time that the additional usage was required. In addition, the customer account could be charged a one-time fee for initiating the higher level of service represented by the second level 172 . In one embodiment, charges for the second level 172 of service would be incurred at a rate that is some additional multiple of the rate charged for the first level 170 . The second level 172 represents a guaranteed expansion level available to the customer for the given period of time. Finally, a third level 174 provides an optional extended additional level of service that may be able to be brought to bare to provide hosted services for the customer account. In this embodiment, the third level 174 provides up to a higher multiple times the level of service as the first level 170 . In one embodiment in order to provide this extended additional level of service, the host system makes use of the multi-site arrangement as previously described in order to bring in the required number of servers to meet this level of service. Preferably, the customer account is charged a second higher rate for the period of time that the extended additional service is reallocated to this customer account. In one embodiment, charges for the third level 174 of service would be incurred at a rate that is an even larger multiple of the first level 170 for the given period of time that the extended additional third level 174 of service is provided for this customer account. Again, the customer account may be charged a one-time fee for initiating this third level 174 of service at any time during the given period. At the end of a given period, the customer may alter the level of service contracted for the given customer account. As shown in FIG. 12 , the service level agreement is increased by 50 percent from a first period to a second period in response to a higher anticipated peak usage for the given customer account. Preferably, the period for a service level agreement for a given customer account would be a monthly basis, with suggestions been presented to the customer for recommended changes to the service level agreement for the upcoming billing period. Although this example is demonstrated in terms of simultaneous connections, it should be understood that the service level agreement for given customer account can be generated in terms of a variety of performance measurements, such as simultaneous connections, hits, amount of data transferred, number of transactions, connect time, resources utilized by different application software programs, the revenue generated, or any combination thereof. It will also be understood that the service level agreement may provide for different levels of commitment for different types of resources, such as front-end servers, back-end servers, network connections or disk storage units. Referring now to FIG. 15 , a block diagram of the preferred embodiment of the local decision software program 70 will be described. A series of measurement modules 180 , 181 , 182 , 183 and 184 each performed independent evaluations of the operation of the particular server on which the local decision software program 70 is executing. Outputs from these measurement modules are provided to an aggregator module 190 of the local decision software program 70 . A predictor module 192 generates expected response times and probabilities for various requests. With priority inputs 194 supplied by the master decision software program 72 from the service level agreement database 152 , a fuzzy inference system 196 determines whether a request to add an engine blade 104 for the administrative group 52 will be made, or whether an offer to give up or remove an engine blade from the administrative group 52 will be made. The request to add or remove a blade is then communicated over communication channel 106 to the master decision software program 72 . In one embodiment, the aggregator module 190 is executed on each server 46 within a given administrative group 52 , and the predictor module 192 and fuzzy inference module 196 are executed on only a single server 46 within the given administrative group 52 with the outputs of the various measurement modules 180 - 184 been communicated to the designated server 46 across the communication channel 106 . In another embodiment, the aggregator module 190 , predictor module 192 and fuzzy inference module 196 may be executed on more than one server within a given administrative group for purposes of redundancy or distributed processing of the information necessary to generate the request add or remove a blade. Preferably, the aggregator module 190 accomplishes a balancing across the various measurement modules 180 - 184 in accordance with the formula: B k =[(Σ T ki /w k )−min k ]*100/(max k −min k )−50 i=1 to w k Where T ki is the time take it for the ith request of measurement type k, w k is the window size for measurement type k, min k is the minimum time expected for measurement type k, and max k is the maximum time to be tolerated for a measurement type k. The balanced request rate B k is then passed to the predictor module 192 and the fuzzy inference module 196 of the local decision software program 70 . The window size for the measurement type k would be set to minimize any unnecessary intrusion by the measurement modules 180 - 184 , while at the same time allowing for a timely and adequate response to increases in usage demand for the administrative group 52 . FIG. 16 shows a sample of the workload measurements from the various measurement modules 180 - 184 under varying load conditions. It can be seen that no single workload measurements provides a constantly predictable estimate of the expected response time and probability for that response time. As such, the fuzzy inference module 196 must consider three fundamental parameters: the predicted response times for various requests, the priority these requests, and probability of their occurrence. The fuzzy inference module 196 blends all three of these considerations to make a determination as to whether to request a blade to be added or remove from the administrative group 52 . An example of a fuzzy inference rule would be: if (priority is urgent) and (probability is abundant) and (expected response time is too high) then (make request for additional blade). Preferably, the end results of the fuzzy inference module 196 is to generate a decision surface contouring the need to request an additional server over the grid of the expected response time vs. the probability of that response time for this administrative group 52 . An example of such a decision surface is shown in FIG. 17 . A portion of the disclosure of this invention is subject to copyright protection. The copyright owner permits the facsimile reproduction of the disclosure of this invention as it appears in the Patent and Trademark Office files or records, but otherwise reserves all copyright rights. Although the preferred embodiment of the automated system of the present invention has been described, it will be recognized that numerous changes and variations can be made and that the scope of the present invention is to be defined by the claims.

A method for operating a commissioned e-commerce service provider provides services to businesses on a computerized network such as the Internet in exchange for a small commission on the commercial transactions generated using those services. Unlike most ISPs that provide services to individuals and businesses, the commissioned e-commerce service provider preferably provides Internet services for businesses operating web sites or other application that generate e-commerce transactions for the business. Instead of paying a monthly fee for the Internet services required to host a web site or operate and e-commerce site, the business contracts with the commissioned e-commerce service provider to provide these services based on receiving a percentage commission of the commercial transactions generated using these services. Preferably, the commission percentage is tiered in accordance with the amount of traffic at the site to provide a nominal level of service at a lower commission rate, yet allow for an exceptional volume of traffic to be accommodated by the site at a higher commission rate without having the site fail or the service become overwhelmed.

FIELD OF THE INVENTION The present invention generally relates to electric heating devices based on heating resistance metal ribbons with increased plasticity intended for wide range of applications: industry, agriculture, medical equipment, radiant heating of premises, under floors and ceiling heating, etc. The electrical heating devices are designed for large range of application: flexible and rigid, with voltage range from 3V up to 400V, with specific power from 50 W per square meter up to 100 kW per square meter (for water heating). BACKGROUND OF THE INVENTION patent U.S. Pat. No. 6,353,707 discloses an electric heating device on base of the ribbon. The ribbon extends along the device and is bent in a plurality of locations, where the ribbon has an electro-conductive coating for mechanically strengthening and electrically shunting it in these locations. U.S. Pat. No. 6,353,707 describes also heating devices comprising an insulating rigid or flexible shell and a flat continuous heating resistance foil ribbon disposed inside the shell. PCT patent Application WO 03/017721 A2 and U.S. patent application Ser. No. 10/367,742 on its base “Electrical Heating Device” disclose an electric heating device including a flexible resistance ribbon of special alloy composition with close limits of components, fastened to fiberglass or plastics net by glued tapes or spots, forming insert, which is incorporated in different plastics shells. It is described different structures of plastics heaters based on this inserts. SUMMARY OF THE INVENTION An electric heating device in accordance with the present invention is based on a heating resistance ribbon of crystalline cold rolled metal foil with thickness less than 100 microns. Preferably, the heating resistance ribbons are formed from wide range of alloys compositions with high specific resistance, particularly from combinations of Fe—Cr—Al—Ni as the cheapest. For one of examples, alloy with electrical resistance 0.98*10 −6 -1.05*10 −6 Ω*m consists of: Cr content is (19-21)%, Ni content is (19.5-21.5)% and Al content is (1-1.5)%. For large range of applications the main requirements to the high resistance ribbon are: electrical resistance stability, mechanical strength and plasticity for bending of the ribbon. The ribbon is arranged in required pattern in different dimensions and shapes, and in many cases the ribbon is used being bent at any angle with radius of ribbon bending equal zero. Therefore, the ribbon must meet the requirements of very high plasticity providing ability to be bent and arranged by any pattern. In some applications bending places exist under conditions of pressure. Such conditions arise, for example, in hermetically closed electrical heating devices for water heating. However standards ribbons from Fe—Cr—Al—Ni alloys don't provide such level of plasticity. In accordance with standards, minimum bending diameter equals triple thickness of the ribbon. For achievement of this purpose U.S. Pat. No. 6,353,707 proposes using of electro-conductive coating (for example, copper coating) in a plurality of ribbon locations, where the ribbon will be bent. This coating is plotted by electroplating method. This method provides performing of pointed task, but it is enough complicated in industry realization. U.S. patent application Ser. No. 10/367,742 describes one of alloy compositions of Fe—Cr—Al type with components content in very close limits, which possesses by most plasticity from alloys of this family. However, even this alloy needs in additional treatment, especially for pressed bent places. It is known a method of plasticity improving of the foil ribbon. This property may be reached by additional thermal treatment (coil annealing): heating up to temperature 740-760° C. and quick cooling. Using of this process before latest cold rolling is unacceptable for rolling plant because the alloy will be covered by solid oxide, which provokes rolls destroy. Using of described coil annealing method after latest cold rolling is also unacceptable, because it reduces mechanical strength of the ribbon. The present invention proposes solution of the alloy plasticity problem. In accordance with this invention, the electrical heating device contains the heating resistance ribbon of crystalline cold rolled metal foil with thickness 100 microns and less formed from wide range of alloys with high specific resistance, particularly from combination of Fe—Cr—Al—Ni. The heating resistance ribbon contains along its length short sections subjected to additional local plasticizing processing. These sections have increased plasticity, allowing to bend the ribbon at the angle within 0-180°, and the heating resistance ribbon is capable of reusable bending and further pressing with radius of ribbon bending equal zero. Length of these sections equals approximately to the length of bended ribbon parts. Method of manufacturing of metal foil ribbon with improved plasticity includes additional local plasticizing processing after traditional cold-rolling process. The plasticizing processing includes local non-contact inductive high frequency thermo-treatment of the above mentioned short sections. Such treatment allows to avoid ribbon strength reducing and to reach required local plasticity level. The additional plasticizing processing comprises passing of the ribbon through high frequency electromagnetic field formed by an inductor. Electromagnetic field is impressed to the above mentioned ribbon sections only. This is reached by forming of high frequency pulses bursts. Power and duration of the pulses bursts are adjusted by control system. Specific power of the electromagnetic field impressed to the ribbon is within 2.0-6.0 W/cm 2 . Duration of said thermo-treatment is not less 0.1 sec. per cm of the section length. The inductive high frequency current provides quick local heating of the ribbon sections up to temperature 740-760° C. The method of manufacturing of metal foil ribbon with improved plasticity including additional local plasticizing processing after traditional cold-rolling process is realized by the following steps: setting of the ribbon such that the ribbon will cross electromagnetic field generated by a high frequency current inductor during ribbon rewinding; setting of adjusted line speed of the ribbon; forming of high frequency pulses bursts by the inductor control system; frequency of the bursts F burst is regulated according with formula: F burst <=1/(t burst +t pause ), where t burst —duration of high frequency pulses burst equal to relation of the length of the section and the ribbon line speed upon rewinding, t pause —time interval between high frequency pulses bursts equal to relation of the length of ribbon between said sections and the ribbon line speed; rewinding of the ribbon from the first bobbin (bobbin-source) to the second bobbin (bobbin-receiver); a line speed of the ribbon is adjusted preliminary. Performed tests show that after additional plasticizing processing the ribbon stand to bending even under conditions of compression. The ribbon also meets the requirements of reusable bending on the same bending place. Such property is very important for heaters production. The present invention proposes also one yet method of local ribbon treatment, which allows to reduce specific power of electromagnetic field and duration of high frequency impulses burst, i.e. to increase line speed of the ribbon. In accordance with this method, before additional local plasticizing processing the ribbon is heated up to initial temperature not exceeding 300° C.-350° C. and only after heating the ribbon is treated by high frequency electromagnetic field. In this case specific power of the electromagnetic field is in limits 1.0-3.0 W/cm 2 , and impulses burst duration is not less 0.05 sec. per cm of the section length. Increasing of initial temperature higher then 370° C. may provoke into structural changes of Fe—Cr—Al—Ni alloy. This invention presents also the electrical heating device, which contains the electrical heating resistance ribbon made of a crystalline cold rolled metal foil with thickness 100 microns and less formed from high resistive alloy particularly containing combination of Fe—Cr—Al—Ni. The electrical heating resistance ribbon is coated by liquid or spray substance selected of group of fluoropolymer mold releases. This coating is separating layer between the ribbon and molding mass, which simultaneously increases radius of the ribbon bending. A further aspect of the present invention is a heating device, which consists of above mentioned electrical heating resistance ribbon subjected to additional local plasticizing processing, arranged in any required pattern and being bent at any angle with radius of ribbon bending equal zero. The bending places are disposed on the sections subjected to additional processing. The ribbon is provided by connectors on its ends for connecting with power source. In another design the heating device consists of the electrical heating resistance ribbon, wherein the electrical heating resistance ribbon is coated by liquid or spray substance selected of group of fluoropolymer mold releases. This coated ribbon is arranged in any required pattern and being bent at any angle. The arranged foil ribbon is provided by connectors on its ends for connecting with power source, and this arranged ribbon with connectors is adapted for molding by melting inorganic (as gypsum, concrete, cement) or polymer mass. As distinct from known heaters, firstly, these heating devices are made of the above mentioned electrical heating resistance ribbon with high level of plasticity and, secondly, free of any adhesive materials fastening the ribbon to any base. Different adhesive materials, including glued tape, glue spot, etc. used for the fastening of the electrical heating resistance ribbon to any base cause of some swellings on device surface. These swellings arise from gas nascent at hot pressing, laminating or other processes. Forming of heating devices, which don't contain any adhesives, allows to avoid pointed swellings. Described heating devices are realized owing to using of manufacturing method, wherein the electrical heating resistance ribbon (both coated and not coated) is arranged in any required pattern without fastening to any support material on an electromagnetic table. Assembling of the structures is realized by the following steps: laying of packaging materials (for example, paper sheet, film) on electro-magnetic table; laying of support materials (for example, mesh, plastic sheet, etc.) on packaging materials; switching on the electromagnetic table; laying of said electrical heating resistance ribbon in required pattern on support material or packaging materials, if the support material is absent; laying of the second layer of support materials; switching off of the electromagnetic table; transportation of the support and packaging materials for subsequent processing (coating, molding, impregnation, pressing, vulcanization) and laying of the following materials. The present invention further proposes the electrical heating device, wherein the electrical heating resistance ribbon is arranged in desired pattern and is placed between two additional layers of mesh as support material. This sandwich is coated by two coatings. The first of them is non sealing liquid or spray substance selected of group of fluoropolymer mold releases. The second of them is non sealing liquid or spray substance of rubber group. The coatings carry out simultaneously three functions: preserves against conglutination of the heating resistance ribbon with any molding mass, fastens mesh layers without adhesive materials and provides keeping of mesh holes, which are necessary for further impregnation by molding mass. The electrical heating resistance ribbon and coated mesh forms the heating device with reinforcing base, which is ready for impregnating by inorganic and organic materials in large range of temperatures. Described structures are effective for silicone or rubber heating devices. In this case electric insulating layers of the heating device are formed of silicone or rubber raw materials, and the electrical heating resistance ribbon, both with mesh and without it, is placed between these layers for further pressing and polymerization (vulcanization). One of preferred variants is a structure, wherein the electrical heating resistance ribbon is arranged in desired pattern and is placed between two additional layers of flexible rubber magnet sheets. Using of flexible rubber magnet sheets as envelops of the hating device allows to fasten easily and tightly the heating device to iron based metal heated surface (for example, pipes, tanks, balloons, containers, etc.). In such applications providing of maximum heat transfer between the heating device and heated surface is one of the main requirements. Therefore, tight fastening is very important. Besides, the flexible rubber magnet sheet serves for facilitation of the heating ribbon arranging process. In another structure the electrical heating resistance ribbon, both with mesh and without it, is molded by different polymer mass. For example, epoxy or polyester resins are used as molding materials. One of preferred variants is a structure, containing the electrical heating resistance ribbon and a fiber reinforced polymer for molding and subsequent pressing. For example, the heating plates obtained after pressing of fiber glass reinforced polyester resin with the electrical heating resistance ribbon show very high quality and long life span. Other design of the described heating device contains the electrical heating resistance ribbon arranged in desired pattern and additional two layers of thermoplastic polymer sheets (for example, PVC). This electrical heating resistance ribbon is placed between them. Thermoplastic layers are fastened between them by gluing and pressing. The present invention disclosures the electrical heating device containing the electrical heating resistance ribbon coated by liquid or spray substance selected of group of fluoropolymer mold releases, which is covered by thermoplastic polymer (for example, PVC, polyethylene) forming a long linear heating strip. This covering is realized during laminating process. The present invention disclosures also the electrical heating device containing the electrical heating resistance ribbon coated by liquid or spray substance selected of group of fluoropolymer mold releases, which is placed inside thermoplastic jacket (for example, PVC, polyethylene) forming a long linear heating strip. This electrical heating device is realized during extrusion process. The thermoplastic jacket consists of one or more extruded layers. In the case of multilayered jacket, the thermoplastic layers are bound between them, and the heating resistance ribbon is tightly covered, but not bound with the thermoplastic jacket. The present invention contains description of different structures of rigid radiant heaters. One of preferred variants is the electrical heating device, containing the electrical heating resistance ribbon arranged in desired pattern and a rigid sheet as a base (for example, ceramic tiles, gypsum panels, rigid plastic panels, natural and synthetic marble, metal sheet, etc.). This electrical heating resistance ribbon is placed on this base and is fastened to the base by resin (for example, epoxy or polyester). The layer of the resin forms simultaneously the electrical insulating layer. Another structure of the electrical heating device contains two rigid sheets (for example, gypsum panels, rigid plastic panels, natural and synthetic marble, metal sheet, etc.) and the electrical heating resistance ribbon between them. These rigid sheets and the electrical heating resistance ribbon are fastened between them by insulating resin (for example, epoxy or polyester). Described rigid electrical heating devices may be built also as the following structure: rigid sheet as a base (for example, ceramic tiles, gypsum panels, rigid plastic panels, natural and synthetic marble, metal sheets, etc.), the electrical heating resistance ribbon placed between two additional layers of mesh, and a layer of resin (for example, epoxy or polyester), which fastens the structure and serves as electrical insulation. In the present invention it is proposed the electrical heating device, wherein the electrical heating resistance ribbon is placed between two additional metal plates with powder or enamel coating, and these plates are tight fastened between them and sealed by a gasket. This electrical heating device is waterproof heater, which may be used in large range of voltage (6-400 V) and specific power. The electrical heating device is designed also for water heating in tanks (boilers). Application of such heating devices with large area allows avoid salts precipitation on the heating devices surface and provides improved circulation of water. The present invention aims to obtain heating devices with wide range of applications, dimensions, forms and specific power, with high reliability and long life span. All these goals can be attained using the proposed electrical heating resistance ribbon with proposed thermo-treatment and coating and different structures on its base. The present invention provides technical solutions, which are innovative and capable of meeting the requirements for their application. The technical solutions are fit for industrial production, and as formulated in the present patent application, constitute a coherent invention. BRIEF DESCRIPTION OF THE DRAWINGS Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: FIG. 1 is schematic view of one embodiment of an electrical heating resistance ribbon arranged in one desired pattern in accordance with the present invention; FIG. 2 is schematic view of one of suitable technological plants for plasticizing processing in accordance with the present invention; FIG. 3 is schematic view of high-frequency inductor for plasticizing processing with additional warming chamber in accordance with the present invention; FIG. 4 is photocopy of one example of a silicone heater, made of a heating ribbon fastened to mesh by adhesive ribbon and bound with silicone layers FIG. 5 is photocopy of the second example of a silicone heater made of a heating ribbon fastened to mesh by adhesive ribbon; FIG. 6 is photocopy of the third example of a silicone heater where metal heating ribbon bound with silicone and burned out; FIG. 7 is photocopy of silicone heater made according the methods described in the present inventions FIG. 8 is schematic top view of a metal plate with powder insulating coating and the electrical heating resistance ribbon arranged in wishful pattern. DETAILED DESCRIPTION OF THE INVENTION The invention shows different variants of using electrical heating devices based on the electrical heating resistance ribbon from crystalline cold rolled metal foil with thickness 100 microns and less. One of the most important characteristics is ability to be bent with any angle and bending diameter decreased up to zero. Using of low alloyed cheap foil from Fe—Cr—Al—Ni family requires additional steps for reliable bend-ability providing. Therefore presented invention proposes using of electrical heating resistance ribbon from crystalline cold rolled metal foil treated by additional local plasticizing processing. This ribbon contains along its length short treated sections. These sections have increased plasticity, allowing to bend the ribbon at the angle within 0-180° with diameter of ribbon bending less than triple thickness of the ribbon and even practically equal zero with subsequent pressing. FIG. 1 shows the ribbon with above mentioned sections. In FIG. 1 the ribbon 1 contains treated sections 2 in bending places 3 . Length of these sections is about the length of a bent places. In presented invention it is described method of manufacturing of the metal ribbon with increased plasticity. After traditional cold-rolling process the ribbon undergoes to the additional local plasticizing processing. FIG. 2 shows one of suitable technological plants. This plant 10 contains rewinding unit of the ribbon and high-frequency inductor. The ribbon 11 is wound from a bobbin-source 12 to a bobbin-receiver 13 . Rolls 14 maintain the ribbon in strained state. Adjusting rolls 15 set the line speed of ribbon. The ribbon 11 crosses electromagnetic field generated by the high-frequency inductor 16 . Control system of the inductor 16 forms bursts of high-frequency pulses. Power and duration of the pulses bursts is forming in dependence on thickness and wide of foil, line speed of the ribbon and length of the sections of bending. Specific power of the electromagnetic field impressed to the ribbon is within 2.0-6.0 W/cm 2 . Duration of the bursts for warming of bending places up to temperature 740-760° C. is not less 0.1 sec. per cm of the section length. The method includes the following steps: setting of the ribbon 11 such that the ribbon will cross the electromagnetic field generated by high frequency inductor 16 during the ribbon rewinding; setting of required speed of rotation of adjusting rolls (rolls 15 ) and accordingly of line speed of the ribbon 11 V ribbon ( FIG. 3 ) forming and turning on the high-frequency pulses bursts such that frequency of the pulses bursts F burst is regulated in accordance with formula: F burst =1/(t burst +t pause ), where t burst is impulse burst duration equal to relation of the length of the section L 0 ( FIG. 3 ) and the ribbon line speed upon rewinding V ribbon , t pause —time interval between pulses burst equal to relation of the length of ribbon between said sections L 1 ( FIG. 3 ) and the ribbon line speed V ribbon ; rewinding of the ribbon 11 from the first bobbin (bobbin-source 12 ) to the second bobbin (bobbin-receiver 13 ) with adjusted line speed of the ribbon. FIG. 2 shows also technological plant 10 with additional chamber 17 for the ribbon preliminary warming. In this case the ribbon is preliminary warmed up to temperature 300-350° C. After stage of preliminary warming, the ribbon crosses electromagnetic field. In this case specific power of electromagnetic field is reduced and it is within 1.0-4.0 W/cm 2 , and bursts duration is not less 0.05 sec. per cm of the section length. FIG. 3 illustrates this process. The ribbon 11 passes high frequency electro-magnetic field generated by inductor 16 . The ribbon has the treated sections 18 . After described plasticizing processing, the electrical heating resistance ribbon is ready to using. The heating ribbon of Fe—Cr—Al—Ni foil may be covered by additional coating of liquid or spray substance selected of group of fluoropolymer mold releases, which is separating layer between the ribbon and molding mass and simultaneously increases diameter of the ribbon bending. On base of described electrical heating resistance ribbons the heating devices may be formed. As it is illustrated by FIG. 1 , the heating device consists of the electrical heating resistance ribbon 1 subjected to additional processing and arranged in any required pattern, and of connectors 4 on ends of the ribbon. As FIG. 1 shows, the ribbon 1 is bent at the angle 120°. Diameter of ribbon bending equals practically zero. Bending places 3 are disposed on the ribbon sections 2 subjected to additional processing. The present invention depicts also structures, which do not contain adhesive materials for fastening of the electrical heating resistance ribbon to any support material, because the adhesive materials provoke different swellings during molding, impregnation, pressing, vulcanization and other processing. Besides, in the present invention the electrical heating resistance ribbon is coated by liquid or spray separating layer selected of group of fluoropolymer mold releases, and this ribbon with connectors forms a heating device adapted for molding by melting inorganic (as gypsum, concrete, cement) and polymer (as resins, silicone or rubber) mass. FIG. 4 , FIG. 5 , FIG. 6 and FIG. 7 illustrate and confirm above-mentioned conclusions. FIG. 4 shows one example of silicone heater 20 , which is made very incorrectly. As distinct from the present invention, in this silicone heater the heating ribbon 21 is fastened by glued tapes 22 and bound with silicone layer during hot pressing process (the upper layer of silicone is transparent). FIG. 5 shows the other sample of silicone heater 23 made with using of adhesive materials. Along these glued tapes plurality of swellings 24 were formed. Such swellings are very dangerous: in these places probability of the heating ribbon destroying is very high. FIG. 6 shows the heating ribbon burned out after several hours of heater operating because the heating ribbon was bound with silicone mass. FIG. 7 shows silicone heater 25 made according the methods of presented invention. After thousands hours of operating swellings did not arise, and the electrical heating resistance ribbon did not destroyed. Thus, the present invention proposes the heating devices on base of the electrical heating resistance ribbon, which do not contain adhesive tapes as a fastening material. Possibility to produce the heating devices, wherein the electrical heating resistance ribbons are not fastened by any adhesive materials, is reached due to proposed method of the heating devices manufacturing. In accordance with this method, the electrical heating resistance ribbon, coated or not coated, is arranged in any required pattern without fastening to any support material by the following steps: laying of packaging materials (for example, paper sheet) or/and support materials (for example, mesh, plastic sheet, etc) on electromagnetic table; switching on of the electromagnetic table; laying of the heating ribbon on packaging or/and support material in required pattern; laying of the second layer of support materials; switching off of the electro-magnetic table; transportation of the packaging or/and support materials for subsequent processing (coating, molding, impregnation, pressing, vulcanization) and laying of the materials for following element. The mesh may be used as a support material. In this case the mesh may be coated by fluoropolymer mold releases and by liquid or spray selected of rubber group. These coatings fasten mesh layers, but do not fill mesh holes and do not prevent to further forming of heating devices. Described heating element with the electrical heating resistance ribbon, coated or not coated, with mesh or without it, may be placed in different structures, forming different flexible heating devices: silicone, rubber raw material, flexible rubber magnet sheets, thermoplastic polymer. In the case of using of flexible rubber magnet sheets as support material, these flexible rubber magnet sheets may be used for mounting of the electrical heating resistance ribbon instead magnet table. The heating devices on base of the electrical heating resistance ribbon, both with mesh and without it, may be built also by molding with different polymer mass (for example, epoxy or polyester resins). This resin with reinforced materials (for example, fiber glass mat) or with filler (for example, sand) forms also electrical insulating layer. High quality heating device containing the electrical heating resistance ribbon and a fiber reinforced polymer may be obtained by molding and subsequent pressing. The electrical heating resistance ribbon coated by liquid or spray substance selected of group of fluoropolymer mold releases, may be covered by thermoplastic polymer (for example, PVC, polyethylene) forming a long linear heating strip. This covering is realized during laminating process. The thermoplastic jacket may be made also of one or more extruded layers. The described heating element on base of the electrical heating resistance ribbon, coated or not coated, with mesh or without it, may be placed also on rigid base (for example, ceramics, gypsum panels, rigid plastic panels, natural and synthetic marble, metal sheets etc.) and fastened by resin. Such heaters may contain also two rigid sheets fastened by any resin (for example, epoxy or polyester). FIG. 8 shows a metal plate 30 with powder coating 31 and the electrical heating resistance ribbon arranged in wishful pattern 32 . The electrical heating device contains two such metal plates. The plates are fastened between them and sealed by a gasket 33 , forming electrical heating devices for warming of air in thermo-ventilator, water heating in tanks, warming of food, etc. The invention has been described in an illustrative manner, and it is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. Clearly, many modifications and variations of the present invention are possible in light of the above teachings. Accordingly, it is to be understood that the invention can practiced otherwise than specifically described.

An electric heating device based on a ribbon of crystalline metal foil with high specific resistance, which is additionally treated to increase its plasticity and/or additionally coated with a mold release agent to enhance compatibility of the ribbon and insulating envelope. The ribbon combines high electrical resistance, high stability, sufficient mechanical strength and relative cheapness with very important properties including significant plasticity and compatibility with insulating polymers, including rubber and silicone. The above compatibility provides high reliability and life span. Different structures for flexible and rigid heaters on the basis of this ribbon are described, as are different applications.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation application of prior divisional application Ser. No. 13/396,974, filed Feb. 15, 2012, which claims the benefit of U.S. application Ser. No. 12/547,934 filed Aug. 26, 2009, now issued U.S. Pat. No. 8,130,753, which is a continuation application of U.S. application Ser. No. 11/025,077 filed Dec. 30, 2004, now issued U.S. Pat. No. 7,602,771, which claims the benefit of prior U.S. application Ser. No. 10/780,557 filed Feb. 19, 2004, now issued U.S. Pat. No. 7,567,556; each of the applications are being incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to multi-service switches and, more particularly, to the architecture and control of a two-dimensional switch that employs temporal cyclic rotators. BACKGROUND [0003] Switch design has received a significant attention and a large variety of switch architecture alternatives has been developed over several decades. Most structures reported in the literature, or used in practice, fall under one of two categories. The first is the multi-stage family of switches and the second is the time-multiplexed space-switch-based family of switches. [0004] Several switch elements may be interconnected to create a modular switch having a capacity that is higher than the capacity of any of the constituent switch elements. A switch element may qualify as a building unit of a modular switch if it is internally contention free. A common-memory switch is an example of a contention-free switch. The ratio of the access capacity of the modular switch to the access capacity of the largest constituent switch element may be called the capacity gain. By necessity, the capacity of each constituent switch element may be considered to be divided into an access capacity and an inner capacity, where the access capacity (also called throughput) is the capacity available to users of the modular switch and the inner capacity is the capacity used for interconnection to other switch elements. A measure of the efficiency of a modular switch may be derived as the ratio of the aggregate access capacity of all constituent switch elements to the total capacity of all constituent switch elements. By these definitions, the efficiency of a single switch element is 1.0 and the capacity gain, G, of a single switch element is 1.0. [0005] One of the popular modular structures is the multi-stage structure known as the Clos network, which comprises an odd number of stages (3, 5, 7, etc.), where a path from any ingress port to any egress port traverses a switch element in each stage. The ultimate capacity of a multi-stage Clos structure is determined by the number of stages and the sizes of its switch elements. The multi-stage Clos-type structure is usually limited to three stages. To reduce or eliminate internal blocking in a three-stage Clos switch, the inner side of each of the first and third switch elements is required to have a higher capacity than the corresponding outer side. With k denoting the number of ingress ports of a first-stage switch element or the number of egress ports of a third-stage switch element, switch elements of dimension N×N each would be used in the middle stage, where N is selected to be larger than k in order to provide an internal expansion to reduce internal blocking caused by misalignment of free channels; all ports in all switch elements are considered to be of equal capacity, e.g., 10 Gigabits per second (Gb/s) each. Switch elements of dimension k×N each would be used in the first stage, and switch elements of dimension N×k each would be used in the third stage. The dimension of the three-stage Clos switch is then (k×N)×(k×N), its capacity is k×N×R, where R is the rated capacity, in bits per second, of each ingress port or egress port. The capacity gain equals k and the efficiency E equals k/(k+2×N). In a data Clos switch, each of the switch elements may have a common-memory structure. [0006] In order to realize a multi-stage switch of large dimension, switch elements of a relatively large dimension would be required. For example, to realize a switch of 8192×8192 using a three-stage structure, non-blocking switch elements of dimension 128×128 would be required. [0007] A high-capacity switch that may use switch elements of relatively smaller dimensions can be realized using a space switch to interconnect the switch elements. A conventional time-multiplexed space switch using input buffers, and usually output buffers, may provide high scalability. Each input buffer may be paired with an output buffer and each paired input and output buffers may be included in an input/output module. The scalability of a conventional time-multiplexed space switch is determined by two factors. The first factor, and the more severe of the two, is the scheduling effort, which is traditionally based on arbitration among input ports vying for the same output port. The second factor is the quadratic fabric complexity of the space switch where structural complexity increases with the square of the number of ports. The capacity gain is determined by the dimension of the space switch and the dimension of an input/output module. Input/output modules each having multiple ports may connect to multiple space switches operating in parallel. [0008] The capability and efficiency of a switching network are determined primarily by its switches and, because of this pivotal role of the switches, switch design continues to attract significant attention. It is desirable to construct modular large-scale switches using switch modules of a relatively small dimension in order to suit a variety of deployment conditions. Modular switches that scale from a moderate capacity, of 160 gigabits per second (Gb/s) having a dimension of 16×16 with 10 Gb/s input or output channels, to a high capacity of hundreds of terabits per second (Tb/s) having a dimension exceeding 16384×16384, using non-blocking switch elements each of a relatively small dimension (not exceeding 8×8, for example) would significantly facilitate the construction of efficient high-capacity networks of global coverage. SUMMARY [0009] A one-dimensional circulating switch may be defined by connection between several switch modules and one or more temporal cyclic rotators. Where a switch module that is part of a first one-dimensional circulating switch is also connected to one or more temporal cyclic rotators that define a second one-dimensional circulating switch, a two-dimensional circulating switch is formed. [0010] Advantageously, the two-dimensional circulating switch may be considered scalable up to multiple Petabits per second, using medium-capacity switch modules. Additionally, the two-dimensional circulating switch may be considered robust in that it continues to function under partial component failure. Further advantageously, the capacity of the two-dimensional circulating switch may be expanded without service interruption. Still further, the two-dimensional circulating switch may be adapted to handle many different services, including those services characterized by packets, bursts, Time Division Multiplexed (TDM) frames, Synchronous Optical Network (SONET) frames, channels, etc. [0011] In accordance with an aspect of the present invention there is provided a two-dimensional circulating switch. The two-dimensional circulating switch includes a plurality of switch modules, a first plurality of rotors and a second plurality of rotors. Each switch module of the plurality of switch modules is: connected to a first rotor from among the first plurality of rotors by a first link and connected to a second rotor from among the second plurality of rotors by a second link. Any two switch modules among the plurality of switch modules connected to a common rotor in the first plurality of rotors connect to different rotors in the second plurality of rotors. Each rotor in the first plurality of rotors is connected to at least as many switch modules in the plurality of switch modules as there are rotors in the second plurality of rotors. [0012] In accordance with another aspect of the present invention there is provided a two-dimensional circulating switch. The two-dimensional circulating switch includes a plurality of primary one-dimensional circulating switches, each primary one-dimensional circulating switch of the plurality of primary one-dimensional circulating switches including at least two switch modules, selected from among a plurality of switch modules, interconnected by a rotor selected from among a plurality of rotors and a plurality of secondary one-dimensional circulating switches, each secondary one-dimensional circulating switch of the plurality of secondary one-dimensional circulating switches including at least two switch modules, selected from among the plurality of switch modules, interconnected by a rotor selected from among the plurality of rotors. Each primary one-dimensional circulating switch includes a switch module included in each secondary one-dimensional circulating switch. [0013] In accordance with a further aspect of the present invention there is provided a method of scheduling a connection from a source switch module to a destination switch module, in a two-dimensional circulating switch having a plurality of rotators and a plurality of switch modules arranged into a first number of primary one-dimensional circulating switches and a second number of secondary one-dimensional circulating switches, where each primary one-dimensional circulating switch includes a switch module from each secondary one-dimensional circulating switch. Where said source switch module and said destination switch module belong to different primary one-dimensional circulating switches and different secondary one-dimension circulating switches, the method includes designating a set of routes from the source switch module to the destination switch module, each route in the set of routes traversing at least two paths, each path traversing one rotator from among the plurality of rotators, and performing a vacancy-matching process for successive paths in at least one route in the set of routes. [0014] Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS [0015] In the figures which illustrate example embodiments of this invention: [0016] FIG. 1 illustrates the architecture of a one-dimensional circulating switch using a single rotator and four switch modules; [0017] FIG. 2 illustrates the architecture of a one-dimensional circulating switch using two rotators and five switch modules; [0018] FIG. 3 illustrates, in a concise representation, the one-dimensional circulating switch of FIG. 2 ; [0019] FIG. 4 illustrates a configuration of a two-dimensional circulating switch comprising ten rotors and twenty-five switch modules, where the rotors are arranged in a first group of five rotors and a second group of five rotors, and each switch module connects to a rotor in the first group of rotors and a rotor in the second group of rotors, in accordance with an embodiment of the present invention; [0020] FIG. 5 illustrates a two-dimensional circulating switch wherein switch modules are arranged in five primary, concisely represented, one-dimensional circulating switches and five secondary, concisely represented, one-dimensional circulating switches and wherein each switch module is part of one of the primary one-dimensional circulating switches and one of the secondary one-dimensional circulating switches according to an embodiment of the present invention; [0021] FIG. 6 illustrates a simplified view of the two-dimensional circulating switch of FIG. 5 , wherein connectivity between a selected switch module and corresponding rotators is illustrated; [0022] FIG. 7 illustrates a simplified view of the two-dimensional circulating switch of FIG. 5 , indicating a representative path set and actual paths between two switch modules; [0023] FIG. 8 illustrates a simplified view of the two-dimensional circulating switch of FIG. 5 , showing two routes between two switch modules, where each of the two routes traverses two paths according to an embodiment of the present invention; [0024] FIG. 9 illustrates a simplified view of the two-dimensional circulating switch of FIG. 5 , wherein three routes between two switch modules are shown, where each of the three routes traverses three paths according to an embodiment of the present invention, and a first path in each route is made through a primary one-dimensional circulating switch; [0025] FIG. 10 illustrates a simplified view of the two-dimensional circulating switch of FIG. 5 , wherein three routes between two switch modules are shown, where each of the three routes traverses three paths according to an embodiment of the present invention, and a first path in each route is made through a secondary one-dimensional circulating switch; [0026] FIG. 11 illustrates the organization of a shared memory in a switch module in the two-dimensional circulating switch of FIG. 5 ; [0027] FIG. 12 illustrates a connection traversing two rotators, hence two paths, in a two-dimensional circulating switch where the two paths are decoupled (temporally-independent); [0028] FIG. 13 illustrates a connection traversing three rotators, hence three paths, in a two-dimensional circulating switch where the three paths are decoupled (temporally independent); [0029] FIG. 14 illustrates a connection traversing two rotators, hence two paths, in the two-dimensional circulating switch of FIG. 5 where each switch module includes a shared memory of the type illustrated in FIG. 11 and the two paths are temporally coupled, in accordance with an embodiment of the present invention; [0030] FIG. 15 illustrates a connection traversing three rotators, hence three paths, in the two-dimensional circulating switch of FIG. 5 where each switch module includes a shared memory of the type illustrated in FIG. 11 and the paths are temporally coupled, in accordance with an embodiment of the present invention; [0031] FIG. 16 illustrates exemplary connectivity tables of rotators for use in defining paths between switch modules in the two-dimensional circulating switch of FIG. 5 ; [0032] FIG. 17 illustrates exemplary connectivity tables for two rotators in the two-dimensional circulating switch of FIG. 5 ; [0033] FIG. 18 illustrates further exemplary connectivity tables for two rotators in the two-dimensional circulating switch of FIG. 5 ; [0034] FIG. 19 illustrates even further exemplary connectivity tables for two rotators in the two-dimensional circulating switch of FIG. 5 ; [0035] FIG. 20 illustrates still further exemplary connectivity tables for two rotators in the two-dimensional circulating switch of FIG. 5 ; [0036] FIG. 21 illustrates exemplary connectivity tables for three rotators in the two-dimensional circulating switch of FIG. 5 ; [0037] FIG. 22 illustrates further exemplary connectivity tables for three rotators in the two-dimensional circulating switch of FIG. 5 ; [0038] FIG. 23 illustrates an exemplary master controller for the two-dimensional circulating switch of FIG. 5 ; [0039] FIG. 24 illustrates exemplary rotator connectivity matrices for two rotators of opposite rotation directions in the two-dimensional circulating switch of FIG. 5 ; [0040] FIG. 25 illustrates an exemplary availability matrix for a rotator in the two-dimensional circulating switch of FIG. 5 ; [0041] FIG. 26 illustrates steps in an exemplary method of scheduling a connection of a specified flow rate in a two-dimensional circulating switch of the type illustrated in FIG. 5 , according to an embodiment of the present invention; [0042] FIG. 27 illustrates steps in a first-order vacancy-matching process as part of the method of FIG. 26 , according to an embodiment of the present invention; and [0043] FIG. 28 illustrates steps in a second-order vacancy-matching process as part of the method of FIG. 26 , according to an embodiment of the present invention. DETAILED DESCRIPTION [0044] FIG. 1 illustrates a one-dimensional circulating switch 100 having plurality of switch modules including a first switch module 122 A, a second switch module 122 B, a third switch module 122 C and a fourth switch module 122 D (collectively or individually 122 ). Each switch module 122 incorporates an ingress switch module and an egress switch module (not individually illustrated). Each switch module 122 cyclically accesses each other switch module 122 during an access phase of a predefined duration in a rotation cycle. A rotator 120 may be used to cyclically interconnect switch modules 122 . The inlet ports of the rotator 120 are labeled a, b, c, and d and the outlet ports are labeled A, B, C, and D. The rotation cycle of a rotator is defined herein as a period of time during which the rotator connects each of its inlet ports to each of its outlet ports according to a predetermined inlet-outlet connectivity pattern. A rotation cycle includes an integer number of access phases. An access phase is also called a rotation phase. Hereinafter, an inlet port of a rotator is referenced as an inlet and an outlet port is referenced as an outlet for brevity. [0045] The first switch module 122 A is electronic-based and receives data from data traffic sources through an ingress link 112 A, delivers data to subtending data traffic sinks through an egress link 114 A, and connects to the rotator 120 through an inbound channel 116 A and an outbound channel 118 A. Similarly, each of the other switch modules 122 B, 122 C, 122 D is also electronic-based and receives data from data traffic sources through a corresponding ingress link 112 B, 112 C, 112 D, delivers data to subtending data traffic sinks through a corresponding egress link 114 B, 114 C, 114 D and connects to the rotator 120 through a corresponding inbound channel 116 B, 116 C, 116 D and a corresponding outbound channel 118 B, 118 C, 118 D. [0046] The rotator 120 may have either an electronic fabric or a photonic fabric. A rotator having a photonic fabric requires Electrical-to-Optical (O-E) and Optical-to-Electrical (E-O) interfaces (not illustrated) to interface with links 116 and 118 . Such interfaces may be placed at respective switch-module ports or at ports of the photonic fabric. The rotator 120 , which functions as a temporal cyclic connector is also referenced hereinafter as a temporal cyclical rotator. The rotator 120 is a passive, memoryless device that provides cyclic interconnection from an inlet (a, b, c, d) to an outlet (A, B, C, D), according to a predefined inlet-outlet connectivity pattern over a predefined rotation cycle. Although FIG. 1 illustrates only four switch modules 122 , it is understood that the number of switch modules 122 is physically limited by the number of dual ports on the rotator 120 (a dual port comprising an inlet port and an outlet port) and operationally limited by a systematic transit delay which increases with the number of switch modules 122 as will be described below. The systematic transit delay in the one-dimensional circulating switch 100 is determined by the connectivity of a source switch module and destination switch module to a rotator and is independent of the path taken. [0047] Although FIG. 1 illustrates a single rotator 120 , a circulating switch 100 may include an array of rotators operating in parallel, with each inbound link 116 A having multiple channels each connecting to an inbound port of switch module 122 A, and each outbound links 118 A having multiple channels each connecting to an outbound port of switch module 122 A. Likewise, each of inbound links 116 B, 116 C, and 116 D has multiple channels each connecting to inbounds ports of switch modules 122 B, 122 C, and 122 D, respectively, and each of outbound links 118 B, 118 C, and 118 D may have multiple channels, each channel connecting to outbound ports of switch modules 122 B, 122 C, and 122 D, respectively. An array of rotators operating in parallel is herein synonymously referenced as a “rotator assembly” or simply a rotor. [0048] An electronic rotator can be constructed to have a relatively large number of dual rotator ports, 16,364, for example. However, delay constraints would limit the number of dual ports to a number of the order of 2,048. The need for a high-capacity rotator to construct a high-capacity switch is eliminated by providing parallel paths for each switch-module pair using a rotor comprising parallel rotators. The parallel rotators preferably have different rotation-phase offsets in order to reduce the mean value of the systematic transit delay as described in the above referenced U.S. patent application Ser. No. 10/780,557. In the two-dimensional circulating switch of the present invention, which will be described hereinafter with reference to FIG. 5 , numerous multiple paths are provided through a lattice structure as will be described with reference to FIGS. 6 to 10 . [0049] As described above, the inlet-outlet connectivity of a rotator is maintained during each rotation phase of the rotation cycle, where a rotation phase is a period of time during which a rotator maintains a particular inlet-outlet connectivity. For example, a particular rotation cycle may include: a first rotation phase in which inlet ‘a’ is connected to outlet ‘A’, inlet ‘b’ is connected to outlet ‘B’, inlet ‘c’ is connected to outlet ‘C’ and inlet ‘d’ is connected to outlet D′; a second rotation phase in which inlet ‘a’ is connected to outlet ‘B’, inlet ‘b’ is connected to outlet ‘C’, inlet ‘c’ is connected to outlet ‘ID’ and inlet ‘d’ is connected to outlet ‘A’; a third rotation phase in which inlet ‘a’ is connected to outlet ‘C’, inlet ‘b’ is connected to outlet D′, inlet ‘c’ is connected to outlet ‘A’ and inlet ‘d’ is connected to outlet ‘B’; and a fourth rotation phase in which inlet ‘a’ is connected to outlet D′, inlet ‘b’ is connected to outlet ‘A’, inlet ‘c’ is connected to outlet ‘B’ and inlet ‘d’ is connected to outlet ‘C’. [0050] FIG. 2 illustrates, in a simplified representation, a one-dimensional circulating switch 200 having a rotor including a first rotator 220 X and a second rotator 220 Y. Advantageously, the second rotator 220 Y may be arranged to have a direction of rotation (i.e., a direction of stepping through the phases of a rotation cycle) opposite to the direction of rotation of the first rotator 220 X. In such a case, the second rotator 220 Y is described as being “complementary” to the first rotator 220 X, and vice versa. Where the first rotator 220 X is called a clockwise rotator 220 X, the second (complementary) rotator 220 Y may be called a counterclockwise rotator 220 Y. The extended one-dimensional circulating switch 200 includes a first switch module 222 A, a second switch module 222 B, a third switch module 222 C, a fourth switch module 222 D and a fifth switch module 222 E (collectively or individually 222 ). [0051] The channels to a switch module 222 from subtending data sources and to subtending data sinks from the switch module 222 are represented as combined into an external dual channel 216 A, 216 B, 216 C, 216 D, 216 E corresponding to each of the switch modules 222 . The inbound channels from the clockwise rotator 220 X to the switch modules 222 and outbound channels from the switch modules 222 to clockwise rotator 220 X are represented as combined into a first internal dual channel 226 A, 226 B, 226 C, 226 D, 226 E corresponding to each of the switch modules 222 . Likewise, the inbound channels from the counterclockwise rotator 220 Y to the switch modules 222 and the outbound channels from the switch modules 222 to the clockwise rotator 220 Y are represented as combined into a second internal dual channel 236 A, 236 B, 236 C, 236 D, 236 E corresponding to each of the switch modules 222 . [0052] As will become clear in the following, in a common memory device provided in each switch module 222 , there may be a transit section corresponding to each of the two rotators 220 X, 220 Y. Data received at the first switch module 222 A for transfer to the second switch module 222 B through the first rotator 220 X may be written to a corresponding first transit section in the common memory of the first switch module 222 A. Likewise, data to be transferred through the second rotator 220 Y may be written in a corresponding second transit section in the common memory of the first switch module 222 A. However, data read out from the first transit section may be transferred through the second rotator 220 Y, and vice versa. It can be shown that the connection of the first switch module 222 A to the second switch module 222 B through an intermediate switch module (say, the third switch module 222 C) and traversing the complementary rotators 220 X, 220 Y results in a desirable fixed delay that is specific to each directed switch module pair (a source switch module and a destination switch module) independent of the intermediate switch module. [0053] Control of the one-dimensional switch module 200 is provided by a master controller 240 communicatively connected to a predetermined switch module 222 E dedicated for the purpose of transferring control instructions to the other switch modules 222 , via the rotators 220 . Each switch module 222 is provided with a module controller (not illustrated) which is communicatively coupled to the master controller 240 and maintains a connectivity-pattern matrix for each of rotators 220 . [0054] In particular, the clockwise rotator 220 X and the counterclockwise rotator 220 Y are illustrated at the left and right ends, respectively, of an array of the switch modules 222 . The first internal dual channels 226 connect each of the switch modules 222 to the clockwise rotator 220 X and the second internal dual channels 236 connect each of the switch modules 222 to the counterclockwise rotator 220 Y. [0055] The external dual channels 216 A, 216 B, 216 C, 216 D, 216 E corresponding to each of the switch modules 222 , connect the switch modules 222 to subtending data sources and to subtending data sinks. Furthermore, the master controller 240 is communicatively connected to the predetermined switch module 222 E. [0056] The arrayed representation of the one-dimensional circulating switch 200 in FIG. 2 is concisely represented in FIG. 3 to remove the explicit connections between the switch modules 222 and the rotators 220 X, 220 Y. It is understood that each of the switch modules 222 A, 222 B, 222 C, 222 D, and 222 E has a channel to an inlet of rotator 220 X, a channel from an outlet of rotator 220 X, a channel to an inlet of rotator 220 Y, and a channel from an outlet of rotator 220 Y. [0057] FIG. 4 illustrates a two-dimensional circulating switch 400 comprising ten rotors 430 - 0 to 430 - 9 (collectively or individually 430 ) and 25 switch modules 422 . Each rotor 430 may include an array of rotators such as the rotators 220 X, 220 Y of FIG. 2 (not individually illustrated in FIG. 4 ). As illustrated, each rotor 430 has a dual link to each of a subset of switch modules 422 . A rotor comprises at least one rotator each rotator having a number of input ports and an equal number of output ports and the input-output connectivity may follow either of two directions; clockwise or counterclockwise. When a rotor 430 has two or more rotators, the rotator may have different rotation shifts and different rotation directions. Each rotor 430 is associated with a subset of switch modules 430 and has a dual link to each switch module 430 in the associated subset of switch modules; the dual link includes a dual channel from each rotator in the rotor. [0058] The rotors 430 are arranged in the two-dimensional circulating switch 400 of FIG. 4 such that they are divided among two groups: a first rotor group 434 - 1 ; and a second rotor group 434 - 2 . The first rotor group 434 - 1 includes five rotors 430 - 0 , 430 - 1 , 430 - 2 , 430 - 3 , 430 - 4 and the second rotor group 434 - 2 includes the other five rotors 430 - 5 , 430 - 6 , 430 - 7 , 430 - 8 , 430 - 9 . There are 25 switch modules 422 in the example of FIG. 4 . Each switch module 422 has a dual link 452 to a rotor 430 in the first rotor group 434 - 1 and a dual link 454 to a rotor 430 in the second rotor group 434 - 2 . So that a dual link need not be illustrated for each of the 25 switch modules, a switch module 422 connecting to a rotor 430 - x in the first rotor group 434 - 1 and a rotor 430 - y in the second rotor group 434 - 2 is identified in FIG. 4 as 430 - xy. [0059] The switch of FIG. 4 is arranged such that any two switch modules 422 that connect to a common rotor 430 in the first rotor group 434 - 1 connect to different rotors in the second rotor group 434 - 2 and vice versa. Each rotor 430 in the first rotor group 434 - 1 connects to five switch modules 422 and each rotor 430 in the second rotor group 434 - 2 connects to five switch modules 422 . A rotor 430 in the second rotor group 434 - 2 and its five associated switch modules 422 form a one-dimensional circulating switch as described in the aforementioned U.S. patent application Ser. No. 10/780,557. Likewise, a rotor 430 in the first rotor group 434 - 1 and its five associated switch modules 422 form a one-dimensional circulating switch. Thus, each switch module is a member of two one-dimensional circulating switches. [0060] FIG. 5 illustrates a two-dimensional circulating switch 500 of FIG. 5 having a uniform arrangement, but otherwise having the same structure of the two-dimensional circulating switch 400 of FIG. 4 . In the two-dimensional circulating switch 500 of FIG. 5 , a plurality of switch modules 522 is arranged in five “primary”, concisely represented, one-dimensional circulating switches 532 and five “secondary”, concisely represented, one-dimensional circulating switches 534 , wherein each switch module 522 is part of one of the primary one-dimensional circulating switches 532 and one of the secondary one-dimensional circulating switches 534 . [0061] A first primary, concisely represented, one-dimensional circulating switch 532 - 0 includes a set of similarly indexed switch modules 522 A 0 , 522 B 0 , 522 C 0 , 522 D 0 , 522 E 0 , a corresponding primary clockwise rotator 520 X 0 and a corresponding primary counterclockwise rotator 520 Y 0 . [0062] A second primary, concisely represented, one-dimensional circulating switch 532 - 1 includes a set of similarly indexed switch modules 522 A 1 , 522 B 1 , 522 C 1 , 522 D 1 , 522 E 1 , a corresponding primary clockwise rotator 520 X 1 and a corresponding primary counterclockwise rotator 520 Y 1 . [0063] A third primary, concisely represented, one-dimensional circulating switch 532 - 2 includes a set of similarly indexed switch modules 522 A 2 , 522 B 2 , 522 C 2 , 522 D 2 , 522 E 2 , a corresponding primary clockwise rotator 520 X 2 and a corresponding primary counterclockwise rotator 520 Y 2 . [0064] A fourth primary, concisely represented, one-dimensional circulating switch 532 - 3 includes a set of similarly indexed switch modules 522 A 3 , 522 B 3 , 522 C 3 , 522 D 3 , 522 E 3 , a corresponding primary clockwise rotator 520 X 3 and a corresponding primary counterclockwise rotator 520 Y 3 . [0065] A fifth primary, concisely represented, one-dimensional circulating switch 532 - 4 includes a set of similarly indexed switch modules 522 A 4 , 522 B 4 , 522 C 4 , 522 D 4 , 522 E 4 , a corresponding primary clockwise rotator 520 X 4 and a corresponding primary counterclockwise rotator 520 Y 4 . [0066] A first secondary, concisely represented, one-dimensional circulating switch 534 A includes a set of similarly indexed switch modules 522 A 0 , 522 A 1 , 522 A 2 , 522 A 3 , 522 A 4 , a corresponding secondary clockwise rotator 520 XA and a corresponding secondary counterclockwise rotator 520 YA. [0067] A second secondary, concisely represented, one-dimensional circulating switch 534 B includes a set of similarly indexed switch modules 522 B 0 , 522 B 1 , 522 B 2 , 522 B 3 , 522 B 4 , a corresponding secondary clockwise rotator 520 XB and a corresponding secondary counterclockwise rotator 520 YB. [0068] A third secondary, concisely represented, one-dimensional circulating switch 534 C includes a set of similarly indexed switch modules 522 C 0 , 522 C 1 , 522 C 2 , 522 C 3 , 522 C 4 , a corresponding secondary clockwise rotator 520 XC and a corresponding secondary counterclockwise rotator 520 YC. [0069] A fourth secondary, concisely represented, one-dimensional circulating switch 534 D includes a set of similarly indexed switch modules 522 D 0 , 522 D 1 , 522 D 2 , 522 D 3 , 522 D 4 , a corresponding secondary clockwise rotator 520 XD and a corresponding secondary counterclockwise rotator 520 YD. [0070] A fifth secondary, concisely represented, one-dimensional circulating switch 534 E includes a set of similarly indexed switch modules 522 E 0 , 522 E 1 , 522 E 2 , 522 E 3 , 522 E 4 , a corresponding secondary clockwise rotator 520 XE and a corresponding secondary counterclockwise rotator 520 YE. [0071] Control of the two-dimensional circulating switch 500 is provided by a master controller 540 communicatively connected to a predetermined switch module 522 E 4 dedicated for the purpose of transferring control instructions to the other switch modules 522 , via the rotators 520 . As will be apparent, master controller 540 may be associated with any other switch module 522 . Each switch module 522 has a module controller (not illustrated) which stores a rotator-connectivity matrix, to be described with reference to FIG. 24 , corresponding to each rotator 520 with which the switch module is associated. Each module controller is communicatively coupled to the master controller 540 . [0072] An example of the connections maintained by each of the switch modules 522 in the two-dimensional circulating switch 500 is illustrated in FIG. 6 to include a first internal dual channel 626 D 1 connecting the switch module 522 D 1 to the corresponding horizontal clockwise rotator 520 X 1 and a second internal dual channel 636 D 1 connecting the switch module 522 D 1 to the corresponding primary counterclockwise rotator 520 Y 1 . Similarly, a first internal dual channel 626 DD connects the switch module 522 D 1 to the corresponding secondary clockwise rotator 520 XD and a second internal dual channel 636 DD connects the switch module 522 D 1 to the corresponding secondary counterclockwise rotator 520 YD. [0073] FIG. 7 illustrates a connection within a primary one-dimensional circulating switch 532 - 1 . A source switch module, 522 A 1 for example, receives data streams from subtending data traffic sources and organizes the received data streams into data segments. A destination switch module, 522 C 1 for example, may be determined based on a data traffic sink associated with one or more of the data segments formed from the received data streams. [0074] Since the destination switch module 522 C 1 and the source switch module 522 A 1 are part of a common, primary, one-dimensional circulating switch 532 - 1 , the transfer of data takes place either directly or through intermediate switch modules 522 within the one-dimensional circulating switch 532 - 1 as detailed in the aforementioned U.S. patent application Ser. No. 10/780,557. Direct transfer may take place in two rotation phases of the rotation cycle. A direct transfer of data segments from the source switch module 522 A 1 to the destination switch module 522 C 1 is represented by direct zero-order path-set 705 , between the source switch module 522 A 1 and the destination switch module 522 C 1 . Direct path-set 705 includes a path through the clockwise rotator 522 X 1 and a path through the counterclockwise rotator 522 Y 1 . [0075] In one rotation phase of the rotation cycle associated with a rotator 520 X 1 of the common, primary, one-dimensional circulating switch 532 - 1 , a data segment destined for a data traffic sink associated with the destination switch module 522 C 1 may be transmitted, by the source switch module 522 A 1 , to the selected rotator 520 X 1 (on path 701 ) through which the data segment passes directly on the way to the destination switch module 522 C 1 (on path 702 ). [0076] Similarly, in one rotation phase of the rotation cycle associated with a rotator 520 Y 1 of the common, primary, one-dimensional circulating switch 532 - 1 , a data segment destined for a data traffic sink associated with the destination switch module 522 C 1 may be transmitted, by the source switch module 522 A 1 , to the selected rotator 520 Y 1 (on path 703 ) through which the data segment passes directly on the way to the destination switch module 522 C 1 (on path 704 ). [0077] As described, there are two zero-order routes from switch module 522 A 1 to switch module 522 C 1 , one route traversing paths 701 and 702 and the other route traversing paths 703 and 704 . The number of zero-order routes, each traversing one rotator 520 , from a first switch module 522 to a second switch module 522 where the first and second switch modules belong to a common one-dimensional circulating switch (primary or secondary) equals the number of rotators associated with the common one-dimensional circulating switch. The zero-order routes for each directed switch-module pair having a common one-dimensional circulating switch ( 532 or 534 ) may be sorted according to their systematic transit delay. [0078] FIG. 8 illustrates a case where the source switch module (say, switch module 522 B 2 ) and the destination switch module (say, switch module 522 E 4 ) are not part of a common one-dimensional circulating switch (either secondary or primary). In a specific rotation phase of the rotation cycle associated with a selected rotator of the primary, one-dimensional circulating switch 532 - 2 to which the source switch module 522 B 2 belongs, a data segment destined for a data traffic sink associated with the destination switch module 522 E 4 may be transmitted, by the source switch module 522 B 2 , directly through a selected rotator to an intermediate switch module 522 E 2 belonging to the one-dimensional circulating switch 532 - 2 using one of two paths in path-set 801 ; one of the two paths traverses rotator 420 X 2 and the other traverses rotator 520 Y 2 . [0079] Intermediate switch module 522 E 2 and destination switch module 522 E 4 belong to secondary one-dimensional circulating switch 534 E which includes rotators 520 XE and 520 YE. In a rotation phase, following the above specific rotation phase, intermediate switch module 522 E 2 may directly transmit to destination switch module 522 E 4 the data segment destined for a data traffic sink associated with switch module 522 E 4 through either a path traversing rotator 520 XE or a path traversing rotator 520 YE (i.e., path-set 802 ). [0080] Alternatively, in a particular rotation phase of the rotation cycle associated with a selected rotator of the secondary, one-dimensional circulating switch 534 B of which the source switch module 522 B 2 is a part, a data segment destined for a data traffic sink associated with the destination switch module 522 E 4 may be transmitted, by the source switch module 522 B 2 , directly through the selected rotator to an alternative intermediate switch module 522 B 4 (path-set 803 ). [0081] Intermediate switch module 522 B 4 and destination switch module 522 E 4 belong to primary one-dimensional circulating switch 532 - 4 which includes rotators 520 X 4 and 520 Y 4 . In a rotation phase, following the above particular rotation phase, intermediate switch module 522 B 4 may directly transmit to destination switch module 522 E 4 the data segment destined for a data traffic sink associated with switch module 522 E 4 through either rotator 520 X 4 or rotator 520 Y 4 (path-set 804 ). [0082] Each of path-sets 801 , 802 , 803 , and 804 includes two paths, one through each of the two rotators of a one-dimensional circulating switch 532 or 534 . Thus, the total number of intersecting first-order routes between the source switch module 522 B 2 and the destination switch module 522 E 4 is eight and the number of non-intersecting first-order routes is four. The number of first-order routes in a first-order route set for a directed switch-module pair (a directed switch-module pair is defined by a source switch module and a destination switch module) is determined by the number of rotators in the rotors traversed by the first-order route set. For example, if each rotor has four rotators, the number of intersecting first-order routes in a first-order route set for a directed switch-module pair belonging to different primary circulating switches 532 and different secondary switch modules 534 would be 32 and the number of non-intersecting first-order routes would be eight. The first-order routes for each directed switch-module pair may be sorted according to their associated systematic transit delay to facilitate connection scheduling. [0083] The number of non-intersecting first-order routes from a source switch module 522 to a destination switch module 522 belonging to a common one-dimensional circulating switch (primary or secondary) having ν>2 switch modules 522 and χ rotators is χ×(ν−2). In the configuration of FIG. 5 , χ=2 and ν=5, yielding six non-intersecting first-order routes. [0084] When data segments are transferred in a two-dimensional circulating switch 500 using a single intermediate switch module, a “first-order temporal matching” process, also called a first-order vacancy-matching process, may be used to determine available rotation phases along a path from the source switch module to an intermediate switch module and a path from the intermediate switch module to the destination switch module. In the example of FIG. 8 , a first-order temporal matching process allocates a free rotation phase (access phase) along a path in path set 801 and a corresponding rotation phase along a path in path set 802 . Alternatively, the first-order temporal matching process may allocate a free rotation phase along a path in path set 803 and a corresponding rotation phase along path 804 . It is noted that path set 801 comprises a path from switch module 522 B 2 to switch module 522 E 2 traversing rotator 520 X 2 and a path from switch module 522 B 2 to switch module 522 E 2 traversing rotator 520 Y 2 . Likewise, path set 802 comprises two paths from switch module 522 E 2 to switch module 522 E 4 one path traversing rotator 520 XE and the other path traversing switch module 520 YE. Similarly, path set 803 includes paths traversing rotators 520 XB and 520 YB and path set 804 includes paths traversing rotators 520 X 4 and 520 Y 4 . [0085] FIG. 9 illustrates a simplified view of the two-dimensional circulating switch 500 of FIG. 5 , wherein data segments are transferred in the two-dimensional circulating switch 500 using two intermediate switch modules. FIG. 10 illustrates another simplified view of the two-dimensional circulating switch 500 of FIG. 5 , wherein data segments are transferred in the two-dimensional circulating switch 500 using two intermediate switch modules. In the examples of FIG. 9 and FIG. 10 , the source switch module is 522 B 2 and the sink (destination) switch module is 522 E 4 . [0086] When data segments are transferred in a two-dimensional circulating switch 500 using two intermediate switch modules, a “second-order temporal matching” (a second-order vacancy matching) process may be used to determine available rotation phases along a path from the source switch module to a first intermediate switch module, a path from the first intermediate switch module to a second intermediate switch module, and a path from the second intermediate switch module to the destination switch module. In the example of FIG. 9 , a second-order temporal matching process may allocate a free rotation phase (access phase) along a path in path set 901 to switch module 522 D 2 , a corresponding rotation phase along a path in path set 902 from switch module 522 D 2 to switch module 522 D 4 , and a corresponding rotation phase along a path in path set 903 from switch module 522 D 4 to destination switch module 522 E 4 . Several other routes from source switch module 522 B 2 to destination switch module 522 E 4 , each traversing two intermediate switch modules, may be considered. In a two-dimensional structure 500 having m>2 rows and n>2 columns (i.e., m primary one-dimensional circulating switches 532 and n secondary two-dimensional circulating switches 534 ), there are, between a source switch module and a destination switch module belonging to different rows and columns, two first-order route sets each traversing a single intermediate switch module and (m+n−4) second order route sets each traversing two intermediate switch modules. There are eight second-order routes for each of the (m+n−4) second order route sets. Thus, in the example of FIG. 5 , where m=n=5, there are six second-order route sets each including eight intersecting routes to a total of 48 routes per switch-module pair. Each path in a route is present during a respective rotation phase in the rotation cycle. The number of non-intersecting second-order routes is 12. [0087] It is important to note that a first-order temporal-matching process (a first-order vacancy-matching process) requires comparing two occupancy states while a second-order vacancy-matching process requires comparing three occupancy states. First-order matching and second-order matching will be discussed in further detail below. [0088] A rotation cycle preferably includes a number of rotation phases equal to the number of switch modules 522 minus one. There is no need to have any switch module 522 connect to itself through a rotator because each switch module 522 is considered to have a common memory shared by all inputs and all outputs of the switch module. [0089] FIG. 11 illustrates the organization of a shared data memory in a switch module 522 ( FIG. 5 ). The data memory is logically divided into three sections. A first section 1102 , called a shipping section, is used for storing data received directly from data sources. A second section 1104 , called a transit section, is used for storing data in transit for switching to other switch modules from among the plurality of switch modules. The second section 1104 is logically divided into a number of sub-sections 1116 , each sub-section 1116 corresponding to a particular switch module and a particular rotator. A third section 1106 , called a receiving section, is used for storing data segments directly destined for data sinks. [0090] FIG. 12 illustrates a route from source switch module 522 B 2 to destination switch module 522 E 4 traversing an intermediate switch module 522 E 2 and two rotators 520 X 2 and 520 YE in the two-dimensional circulating switch 500 of FIG. 5 . Each switch module has a shared memory logically organized in a common shipping section 1202 and a common receiving section 1206 : 1202 B 2 , 1206 B 2 in switch module 522 B 2 ; 1202 E 2 , 1226 E 2 in switch module 522 E 2 ; and 1202 E 4 , 1206 E 4 in switch module 522 E 4 . Transit data received at intermediate switch module 522 E 2 , from source switch module 522 B 2 through the first rotator 520 X 2 , is placed in the common shipping section 1202 E 2 of the intermediate switch module 522 E 2 . The transit data is sent by the intermediate switch module 522 E 2 to the destination switch module 522 E 4 whenever a path through the second rotator 520 YE becomes available. Thus, a connection along the route uses two decoupled temporally-independent paths because the transit data can wait in the intermediate switch module 522 E 2 for an arbitrary period of time. The use of decoupled paths significantly simplifies connection scheduling. However, this results in unpredictable queueing delay variation which may require buffering data at the destination switch module for a large period of time to collate data units belonging to a common data stream. [0091] FIG. 13 illustrates a route from a source switch module 522 B 2 to a destination switch module 522 E 4 traversing two intermediate switch modules 522 D 2 , 522 D 4 and three rotators 520 X 2 , 520 YD, and 520 X 4 in a two-dimensional circulating switch 500 . Each switch module has a shared memory logically organized in a common shipping section 1302 and a common receiving section 1306 : 1302 B 2 , 1306 B 2 in switch module 522 B 2 ; 1302 D 2 , 1326 D 2 in switch module 522 D 2 ; 1302 D 4 , 1306 D 4 in switch module 522 D 4 ; and 1302 E 4 , 1306 E 4 in switch module 522 E 4 . Data sent along the route is held at the shipping sections 1302 D 2 and 1302 D 4 of the first and second intermediate switch modules, respectively, and forwarded whenever paths through the second and third rotators 520 YD and 520 X 4 are available. Thus, a connection from a source switch module 522 B 2 to a destination switch module 522 E 4 uses three decoupled temporally-independent paths. [0092] FIG. 14 illustrates a route from source switch module 522 B 2 to destination switch module 522 E 4 traversing an intermediate switch module 522 E 2 and two rotators 520 X 2 and 520 YE in a two-dimensional circulating switch 500 . Unlike the example of FIG. 12 , each switch module 522 is organized into three sections, as illustrated in FIG. 11 , including a shipping section 1402 , a transit section 1404 , and a receiving section 1406 , with corresponding indices B 2 , E 2 , and E 4 and each transit section 1404 is divided into sections 1416 . The paths between successive switch modules 522 are temporally coupled, thus requiring a first-order vacancy-matching process. A data segment in transit at an intermediate switch module 522 E 2 is held in a corresponding sub-section 1416 in the transit section 1404 E 2 . When a sub-section 1416 is reserved, a subsequent data segment of the same data stream (directed to destination switch module 522 E 4 ) may wait at its source switch module. Thus, successive data segments of the same data stream experience the same systematic transit delay which is determined solely by the route selected and is independent of traffic conditions. [0093] FIG. 15 illustrates a route from a source switch module 522 B 2 to a destination switch module 522 E 4 traversing two intermediate switch modules, 522 D 2 , 522 D 4 and three rotators 520 X 2 , 520 YD, and 520 X 4 , in a two-dimensional circulating switch 500 ( FIG. 5 ), where each switch module is of the type illustrated in FIG. 11 . Each switch module 522 is organized into three sections including a shipping section 1502 , a transit section 1504 , and a receiving section 1506 , with corresponding indices B 2 , D 2 , D 4 , and E 4 and each transit section 1504 is divided into sections each for holding at least one data segment. The traversed paths are temporally coupled. A data segment transmitted along the route is read from the shipping section 1502 B 2 of switch module 522 B 2 , written in a transit section in switch module 522 D 2 , then in a transit section in switch module 522 D 4 , then in the receiving section 1506 E 4 of destination switch module 522 E 4 . A data segment written in a transit section of a switch module is read within a rotation cycle and, hence, the two paths traversing rotators 520 X 2 and 520 YD are temporally coupled. [0094] A reference phase of a rotator may be defined by the output port to which input port 0 is connected at the start of a rotation cycle. The rotators 520 in the two-dimensional circulating switch 500 may have different rotation reference phases. However, hereinafter, all clockwise rotators 520 Xj, j=0, 1, 2, 3, and 4, are considered to have the same reference phase, i.e., they all rotate in step connecting likewise numbered inlets to likewise numbered outlets during a given rotation phase of the rotation cycle. Similarly, all counterclockwise rotators 520 Yj, j=0, 1, 2, 3, and 4, have the same reference phase, all clockwise rotators 520 XA, 520 XB, 520 XC, 520 XD, and 520 XE rotate in step and all counterclockwise rotators 520 YA, 520 YB, 520 YC, 520 YD, and 520 YE rotate in step. With identical switch modules 522 , all primary one-dimensional circulating switches 532 are identical and all “secondary” one-dimensional circulating switches 534 are identical. Thus, it suffices to use only four spatial-temporal patterns for the entire two-dimensional switch 500 . It is noted that the number of spatial-temporal patterns depends on the number of rotators per rotor. For example, if all rotors are identical and each rotor uses four rotators where any two rotators have either different rotation directions or different reference phases, the number of rotation patterns would be sixteen. [0095] FIG. 16 illustrates four connectivity tables 1610 , 1611 , 1620 , and 1621 used in defining paths between switch modules in the two-dimensional circulating switch 500 of FIG. 5 which uses two rotators of opposite rotation direction for each one-dimensional circulating switch 532 or 534 . Each connectivity table indicates a switch module to which each switch module 522 connects through a selected rotator 520 during a particular rotation phase. A cyclic-time row 1612 indicates a cyclic time, t, 0≦t<4, over three rotation cycles and an absolute time row 1614 indicates an absolute time, T. A first source switch module-identity column 1630 references five switch modules ( 522 Aj, 522 Bj, 522 Cj, 522 Dj, 522 Ej) as Aj to Ej associated with rotators 520 Xj and 520 Yj (that is, belonging to one-dimensional primary circulating switch 532 - j ), where j=0, 1, 2, 3, or 4. Likewise, a second source switch module-identity column 1640 references five switch modules ( 522 k 0 , 522 k 1 , 522 k 2 , 522 k 3 , 522 k 4 ) as k 0 to k 4 for rotator 520 Xk and 520 Yk (that is, belonging to one-dimensional secondary circulating switch 534 - k ), where k is any of indices {A, B, C, D, E}. [0096] The four connectivity tables 1610 , 1611 , 1620 , 1621 , respectively indicate the connectivity of each switch-module pair within: a primary one-dimension circulating switch 532 through a clockwise rotator; a primary one-dimension circulating switch 532 through a counterclockwise rotator; a secondary one-dimension circulating switch 534 through a clockwise rotator; and a secondary one-dimension circulating switch 534 through a counterclockwise rotator. [0097] A source switch module 522 belonging to primary one-dimensional circulating switch 532 - j and listed in the module-identity column 1630 connects to destination switch modules, in one-dimensional circulating switch 532 - j , identified in the first connectivity table 1610 during successive rotation phases through rotator 520 Xj, and to destination switch modules, in one-dimensional circulating switch 532 j , identified in the second connectivity table 1611 during successive rotation phases through rotator 520 Yj, where the index j, 0≦j<4, identifies a primary one-dimensional circulating switch 532 . [0098] A source switch module 522 belonging to secondary one-dimensional circulating switch 534 - k and listed in the module-identity column 1640 connects to destination switch modules, in one-dimensional circulating switch 534 - k , identified in the third connectivity table 1620 during successive rotation phases through rotator 520 Xk, and to destination switch modules, in one-dimensional circulating switch 534 - k , identified in the fourth connectivity table 1621 during successive rotation phases through rotator 520 Yk, where the index k denotes any of the indices {A, B, C, D, E} identifying the secondary one-dimensional circulating switches in FIG. 5 . [0099] Consider that it is desired to transfer data segments from source switch module 522 B 2 to destination switch module 522 E 4 through a path traversing clockwise rotator 520 X 2 then clockwise rotator 520 XE for the two-dimensional circulating switch 500 of FIG. 5 . FIG. 17 illustrates the use of the first connectivity table 1610 and the third connectivity table 1620 . Tables 1610 and 1620 are used when rotators 520 X 2 and 520 XE are selected to connect a switch module 522 A 2 , 522 B 2 , 522 C 2 , or 522 D 2 of primary one dimensional circulating switch 532 - 2 to any of switch modules 522 E 0 , 522 E 1 , 522 E 3 , or 522 E 4 of secondary one dimensional circulating switch 534 -E. A route from source switch module 522 B 2 to destination switch module 522 E 4 through intermediate switch module 522 E 2 is illustrated. [0100] In such a case, the first connectivity table 1610 may be used to determine that source switch module 522 B 2 connects to intermediate switch module 522 E 2 through rotator 520 X 2 during rotation phase t=2 (T=2) and the third connectivity table 1620 may be used to determine that intermediate switch module 522 E 2 connects to destination switch module 522 E 4 through rotator 520 XE during rotation phase t=1 (T =1, 5, 9, 13, etc.). A systematic transit delay along the indirect route has a value of three rotation phases (5−2). FIG. 17 also illustrates a reverse route from switch module 522 E 4 to switch module 522 B 2 with a systematic transit delay of one rotation phase. The sum of the systematic transit delays of the forward and reverse routes equals the duration of the rotation cycle (four rotation phases). [0102] Transfer of data segments from source switch module 522 B 2 to destination switch module 522 E 4 through a path traversing clockwise rotator 520 X 2 then counterclockwise rotator 520 YE is illustrated in FIG. 18 using the first connectivity table 1610 and the fourth connectivity table 1621 . Tables 1610 and 1621 are used when rotators 520 X 2 and 520 YE are selected to connect a switch module 522 A 2 , 522 B 2 , 522 C 2 , or 522 D 2 of primary circulating switch 532 - 2 to any of switch modules 522 E 0 , 522 E 1 , 522 E 3 , or 522 E 4 of secondary circulating switch 534 E. A route from source switch module 522 B 2 to destination switch module 522 E 4 through intermediate switch module 522 E 2 is illustrated. [0103] In such a case, the first connectivity table 1610 may be used to determine that source switch module 522 B 2 connects to intermediate switch module 522 E 2 through rotator 520 X 2 during rotation phase t=2 (T=2) and the fourth connectivity table 1621 may be used to determine that intermediate switch module 522 E 2 connects to destination switch module 522 E 4 through rotator 520 YE during rotation phase t=2 (T=2, 6, 10, 14, etc.). A systematic transit delay along the indirect route has a value of four rotation phases (6−2). FIG. 18 also illustrates a reverse route from switch module 522 E 4 to switch module 522 B 2 where switching occurs within the same rotation phase (the systematic transit delays illustrated are based on a discipline of writing then reading within a rotation phase). The sum of the systematic transit delays of the forward and reverse routes equals the duration of the rotation cycle (four rotation phases). [0104] FIG. 19 illustrates transfer data segments from source switch module 522 B 2 to destination switch module 522 E 4 through a path traversing counterclockwise rotator 520 Y 2 then clockwise rotator 520 XE where the systematic transit delay equals 4 rotation phases. FIG. 19 also illustrates a reverse route from switch module 522 E 4 to switch module 522 B 2 with systematic transit delays similar to those of FIG. 18 . [0105] FIG. 20 illustrates transfer data segments from source switch module 522 B 2 to destination switch module 522 E 4 through a path traversing counterclockwise rotator 520 Y 2 then counterclockwise rotator 520 YE where the systematic transit delay equals one rotation phase. FIG. 20 also illustrates a reverse route from switch module 522 E 4 to switch module 522 B 2 with a systematic transit delay of three rotation phases. [0106] There are eight intersecting first-order routes from source switch module 522 B 2 to destination switch module 522 E 4 that employ one intermediate switch module each, and each of the routes has an associated switching delay: 522 B 2 - 520 X 2 - 522 E 2 - 520 XE- 522 E 4 ; 522 B 2 - 520 X 2 - 522 E 2 - 520 YE- 522 E 4 ; 522 B 2 - 520 Y 2 - 522 E 2 - 520 XE- 522 E 4 , 522 B 2 - 520 Y 2 - 522 E 2 - 520 YE- 522 E 4 ; 522 B 2 - 520 XB- 522 B 4 - 520 X 4 - 522 E 4 ; 522 B 2 - 520 XB- 522 B 4 - 520 Y 4 - 522 E 4 ; 522 B 2 - 520 YB- 522 B 4 - 520 X 4 - 522 E 4 ; and 522 B 2 - 520 YB- 522 B 4 - 520 Y 4 - 522 E 4 . [0115] There are also eight intersecting first-order routes from source switch module 522 B 2 to each of the other 15 switch modules that do not have a one-dimensional circulating switch (either primary or secondary) in common with source switch module 522 B 2 . That is, there are 128 routes from source switch module 522 B 2 that use one intermediate switch module each to reach a destination switch module. As there are 25 potential source switch modules, 3200 routes that use one intermediate switch module each to reach a destination switch module may be generated for the two-dimensional circulating switch 500 of FIG. 5 . Each of the routes is characterized by a corresponding systematic transit delay. A route that uses one intermediate switch module requires a first-order vacancy-matching process and is referenced as a first-order route. [0116] The first-order routes from a source switch module to a sink switch module may be sorted according to the systematic transit delay to facilitate route-selection. [0117] As discussed, there are 48 second-order routes, from each source switch module 522 to each other switch module 522 in the configuration of FIG. 5 , each traversing two intermediate switch modules. FIG. 21 illustrates a route from source switch module 522 B 2 to destination switch module 522 E 4 traversing clockwise rotator 520 X 2 , any of counterclockwise rotators 520 Yj, where the index j is any of indices {A, B, C, D, and E}, then clockwise rotator 520 X 4 . A first connectivity table 1610 - 1 ( FIG. 16 ), a fourth connectivity table 1621 , and a first connectivity table 1610 - 2 are used to determined the systematic transit delay associated with the route. [0118] A source switch module listed in the first module-identity column 1630 connects to destination switch modules identified in connectivity table 1610 - 1 during successive rotation phases through the rotator 520 X 2 . Using switch module 522 A 2 as the first intermediate switch module, a source switch module listed in the source switch module-identity column 1640 connects to switch modules identified in connectivity table 1621 during successive rotation phases through the rotator 520 YA. The second intermediate switch module is now determined as 522 A 4 and a source switch module listed in the source switch module-identity column 1630 in table 1610 - 2 connects to destination switch modules identified in connectivity table 1610 - 2 during successive rotation phases through the rotator 520 X 4 . [0119] Consider that it is desired to transfer data segments from source switch module 522 B 2 to destination switch module 522 E 4 along the route traversing rotators 520 X 2 , 520 YA, and 520 X 4 . In such a case, connectivity table 1610 - 1 may be used to determine that source switch module 522 B 2 connects to the first intermediate switch module 522 A 2 through rotator 520 X 2 during rotation phase t=3. Connectivity table 1621 may be used to determine that the first intermediate switch module 522 A 2 connects to the second intermediate switch module 522 A 4 through rotator 520 YA during rotation phase t=2 (T=2, 6, 10, 14, etc.). Connectivity table 1610 - 2 may be used to determine that the second intermediate switch module 522 A 4 connects to the destination switch module 522 E 4 through rotator 520 X 4 during rotation phase t=3 (T=3, 7, 11, 15, etc.). The transfer of any data segment from source switch module 522 B 2 to destination switch module 522 E 4 along the route takes place at T=3 from source switch module 522 B 2 to intermediate switch module 522 A 2 , at T=6 from intermediate switch module 522 A 2 to intermediate switch module 522 A 4 , and at T=7 from intermediate switch module 522 A 4 to destination switch module 522 E 4 , resulting in a systematic transit delay of four rotation phases (7−3). [0120] FIG. 22 illustrates another second-order route from source switch module 522 B 2 to destination switch module 522 E 4 traversing counterclockwise rotator 520 YB, any of clockwise rotators 520 Xj, and counterclockwise rotator 520 YE, where the index j is any of indices 0 to 4. A connectivity table 1621 - 1 ( FIG. 16 ), a connectivity table 1610 , and a connectivity table 1621 - 2 may be used to determine the systematic transit delay of the route. Using switch module 522 B 0 as the first intermediate switch module, a source switch module listed in the source switch module-identity column 1640 connects to switch modules identified in the connectivity matrix 1621 during successive rotation phases through the rotator 520 YB. The second intermediate switch module is now determined as 522 E 0 and a source switch module listed in the source switch module-identity column 1640 in connectivity table 1621 - 2 connects to destination switch modules identified in the connectivity table 1621 - 2 during successive rotation phases through the rotator 520 YE. The systematic transit delay along this route is illustrated to equal three rotation phases as indicated in FIG. 22 . [0121] The switching delay along seven additional indirect routes that use the same two intermediate switch modules each between source switch module 522 B 2 and destination switch module 522 E 4 may be determined. Additionally, there exist 40 more routes that use two intermediate switch modules between source switch module 522 B 2 and destination switch module 522 E 4 , each characterized by a systematic transit delay. [0122] Likewise, there are also 48 routes from source switch module 522 B 2 to each of the other 15 switch modules that do not have a one-dimensional circulating switch (either primary or secondary) in common with source switch module 522 B 2 . That is, there are 768 routes from source switch module 522 B 2 that use two intermediate switch modules each to reach a destination switch module. As there are 25 potential source switch modules, there are 19200 routes that use two intermediate switch modules each to reach a destination switch module for the two-dimensional circulating switch 500 of FIG. 5 . Each of the routes has a corresponding systematic transit delay. [0123] As was the case with first-order routes that use a single intermediate switch module each to reach a destination switch module, the second-order routes in each second-order route set from a source switch module to a destination switch module may be sorted according to the systematic transit delay in order to facilitate route selection and scheduling. [0124] FIG. 24 illustrates exemplary rotator connectivity matrices 2410 - 1 and 2410 - 2 for a clockwise rotator 520 Xν and a counterclockwise rotator 520 Yν, respectively, where 0≦ν≦4 for a rotator (clockwise or counterclockwise) associated with a primary one-dimensional circulating switch 532 -ν and ν is any of indices {A,B,C,D,E} for a rotator (clockwise or counterclockwise) associated with a secondary one-dimensional circulating switch 534 -ν. An entry 2412 in connectivity matrix 2410 - 1 contains an identifier of a rotation phase, of a rotation cycle, during which a corresponding source switch module 522 Aν, 522 Bν, 522 Cν, 522 Dν, or 522 Eν is connected to a destination switch module 522 Aν, 522 Bν, 522 Cν, 522 Dν, or 522 Eν through a clockwise rotator 520 Xν. The rotation cycle in the configuration of FIG. 5 has four rotation phases labeled 0, 1, 2, and 3. Likewise, an entry 2410 - 2 contains an identifier of a rotation phase, within the rotation cycle, during which a corresponding source switch module connects to a corresponding destination switch module through a counterclockwise rotator 520 Yv. An entry 2412 or 2422 marked “x” corresponds to a non-existent path; a switch module does not connect to itself through any rotator. [0125] If all clockwise rotators have the same reference phase and all counterclockwise rotators have the same reference phase, then only the two connectivity matrices 2410 - 1 and 2410 - 2 would be needed. The clockwise rotators or counterclockwise rotators may, however, be phase-shifted thus requiring additional connectivity matrices 2410 . [0126] The master controller 540 is provided with a scheduler 2308 , as illustrated in FIG. 23 . The scheduler 2308 includes a processor 2306 that may be loaded with computer executable instructions for executing methods exemplary of the present invention from a computer readable medium 2310 , which could be a disk, a tape, a chip or a random access memory containing a file downloaded from a remote source. The scheduler 2308 connects to a transmitter 2302 and a receiver 2304 for sending and receiving from switch module 522 E 4 . The master controller 540 may store in a memory (not shown) a connectivity pattern of each rotator of each rotor 520 . [0127] In operation, the source switch module 522 B 2 receives data streams from subtending data traffic sources and organizes the received data streams into data segments. The destination switch module 522 E 4 may be determined based on a data traffic sink identifier associated with one or more of the data segments formed from the received data streams. [0128] The source switch module 522 B 2 transmits to the master controller 540 an indication of a requirement to transfer data segments to the destination switch module 522 E 4 , the indication may be called a “connection request” specifying switch module 522 B 2 as a source switch module and switch module 522 E 4 as a destination switch module. At the master controller 540 , the scheduler 2308 receives the connection request and consults a table containing a route set of routes requiring first-order vacancy-matching to select a route from the source switch module 522 B 2 to the destination switch module 522 E 4 . The scheduler 2308 may first, for instance, consult the route set of routes having the least systematic transit delay. [0129] Having selected a candidate route, for example, 522 B 2 - 520 X 2 - 522 E 2 - 520 XE- 522 E 4 , from the consulted route set, the scheduler 2308 may then determine whether the path between source switch module 522 B 2 and intermediate switch module 522 E 2 traversing rotator 520 X 2 is available. Subsequently, the scheduler 2308 may determine whether the path between intermediate switch module 522 E 2 and destination switch module 522 E 4 traversing rotator 520 XE is available. Such a determination may be made by consulting availability matrices 2510 (to be described below) of paths traversing each of the rotators 520 X 2 , 520 XE. [0130] The process of determining availability of paths traversing rotators 520 X 2 , 520 XE in the rotation phases that correspond to the rotation phases required by the candidate route is termed “first-order temporal matching” or “first-order vacancy matching”. [0131] Where either one of the paths traversing rotators 520 X 2 , 520 XE is unavailable, the scheduler 2308 may consult the route set of routes requiring first-order matching to select another candidate route. Having selected another candidate route, for example, 522 B 2 - 520 XB- 522 B 4 - 520 Y 4 - 522 E 4 , from the consulted route set, the scheduler 2308 may then determine the availability of the paths traversing rotators 520 XB, 520 Y 4 . [0132] Where either one of the paths traversing rotators 520 XB, 520 Y 4 is unavailable, the scheduler 2308 may consult a route set of routes requiring second-order matching to select a second-order route from the source switch module 522 B 2 to the destination switch module 522 E 4 . The scheduler 2308 may select the second-order route of least systematic transit delay. [0133] Having selected 522 B 2 - 520 X 2 - 522 A 2 - 520 YA- 522 A 4 - 520 X 4 - 522 E 4 from the consulted route set as the candidate route, the scheduler 2308 may then determine the availability of paths traversing rotators 520 X 2 , 520 XA, 520 X 4 . The process of determining availability of paths traversing rotators 520 X 2 , 520 XA, 520 X 4 may be termed “second-order temporal matching” or “second-order vacancy matching”. [0134] Where all three paths traversing rotators 520 X 2 , 520 YA, 520 X 4 are available, the scheduler 2308 may: instruct the source switch module 522 B 2 to transmit the data segments associated with a data sink connected to the destination switch module 522 E 4 through rotator 522 X 2 to intermediate switch module 522 A 2 ; instruct the first intermediate switch module 522 A 2 to transmit data segments received from the source switch module 522 B 2 through rotator 520 YA to the second intermediate switch module 522 A 4 ; and instruct the second intermediate switch module 522 A 4 to transmit data segments received from the first intermediate switch module 522 A 2 through rotator 520 X 4 to destination switch module 522 E 4 . [0135] Additionally, the scheduler 2308 may mark each of the availability matrices associated with the rotators 520 X 2 , 520 YA, 520 X 4 so that the planned usage of the rotators 520 X 2 , 520 YA, and rotator 520 X 4 is recorded. [0136] Exemplary availability matrix 2510 - 1 for inter-switch-module paths traversing a rotator 520 Xj, or 520 Yj, 0≦j<4, associated with a primary one-dimensional circulating switch, is illustrated in FIG. 25 . The availability matrix 2510 - 1 provides an indication of availability (“0”) and non-availability (“1”) for paths traversing rotator 520 X 2 for example. Exemplary availability matrix 2510 - 2 for inter-switch-module paths traversing rotator 520 Xk or 520 Yk, where k is any of indices {A, B, C, D, E} is illustrated in FIG. 25 . The availability matrix 2510 - 2 provides an indication of availability (“0”) and non-availability (“1”) for paths traversing rotator 520 XB, for example. An availability matrix 2510 is needed for each rotator 520 in the two-dimensional circulating switch 500 of FIG. 5 . [0137] In an embodiment of an aspect of the present invention, to successfully find a first-order vacancy match, the scheduler 2308 finds a “0” in the entry corresponding to the desired source switch module and the desired intermediate switch module in the matrix 2510 corresponding to the first desired rotator and also finds a “0” in the entry corresponding to the desired intermediate switch module and the desired destination switch module in the availability matrix 2510 corresponding to the second desired rotator. [0138] In an embodiment of an aspect of the present invention, to successfully find a second-order vacancy match, the scheduler 2308 finds a “0” in the entry corresponding to the desired source switch module and the desired first intermediate switch module in the availability matrix 2510 corresponding to the first desired rotator, finds a “0” in the entry corresponding to the desired first intermediate switch module and the desired second intermediate switch module in the availability matrix 2510 corresponding to the second desired rotator and also finds a “0” in the entry corresponding to the desired second intermediate switch module and the desired destination switch module in the availability matrix 2510 corresponding to the third desired rotator. Fine Granularity [0139] Each rotation phase may be divided into an integer number of time slots each time slot having a sufficient duration to accommodate a data segment. Thus, during a rotation phase, multiple data segments which may have different destination switch modules may be transferred from a switch module to another. [0140] It may be desirable to use a scheduling cycle that covers an integer number of rotation cycles. As such, a scheduling time frame may be defined with a duration equivalent to an integer multiple of the time taken for one rotation cycle. [0141] The scheduling time frame may be used in a method of scheduling a connection of a specified flow rate in a two-dimensional circulating switch, steps of which are illustrated in FIG. 26 . FIG. 26 illustrates a route-selection and scheduling process for a connection from a source switch module 522 to a destination switch module 522 where the source and destination switch modules belong to different primary circulating switches 532 and different secondary circulating switches 534 . When the source switch module and the destination switch module belong to a common one-dimensional circulating switch (primary or secondary), the connection is preferably established within the common one-dimensional circulating switch according to a process described in the aforementioned U.S. patent application Ser. No. 10/780,557. [0142] In particular, the scheduler 2308 may receive a connection request (step 2602 ) from a switch module, where the connection request specifies a source switch module, a destination switch module and a requested flow rate. A flow-rate unit may be defined as the size of one data segment divided by the period of a rotation cycle. Recall that a rotation cycle includes a number of rotation phases equal to the number of switch modules minus one, and a rotation phase may include multiple time slots. By dividing the requested flow rate by the flow-rate unit, the scheduler 2308 may determine (step 2604 ) a required number of time slots (Γ) in a scheduling time frame necessary to accommodate the connection request. [0143] The scheduler 2308 , as a first step in determining a total number of allocable time slots (Q), may initialize Q to zero (step 2606 ). The scheduler 2308 may then determine a first allocable number (q1) of time slots by performing first-order vacancy matching (step 2610 ). First-order vacancy matching is expanded upon in FIG. 27 . The scheduler 2308 may then add the first allocable number of time slots to the total number of allocable time slots (step 2612 ). [0144] The total number of allocable time slots may then be compared (step 2614 ), by the scheduler 2308 , to the required number of time slots. Where the required number of time slots exceeds the total number of allocable time slots, the scheduler 2308 may determine a second allocable number (q2) of time slots by performing second-order vacancy matching (step 2616 ). Second-order vacancy matching is expanded upon in FIG. 28 . The scheduler 2308 may then add the second allocable number of time slots to the total number of allocable time slots (step 2618 ). [0145] The total number of allocable time slots may again be compared (step 2614 ), by the scheduler 2308 , to the required number Γ of time slots. Where the total number Q of allocable time slots reaches the required number Γ of time slots, the scheduler 2308 may allocate the required number of allocable time slots to satisfy the connection request (step 2620 ). According to the allocation, the scheduler 2308 may update the availability matrices of each of the rotators affected by the allocation (step 2622 ) and send instructions to the affected source switch module and intermediate switch modules (step 2624 ), where the instructions indicate an identifier of a subsequent switch module. As described earlier, each switch module 522 has a module controller (not illustrated) which stores a rotator-connectivity matrix 2410 corresponding to each rotator 520 with which the switch module is associated. The instructions, perhaps combined with instructions related to satisfying other connection requests, may be considered to form a “schedule” of operation for each switch module 522 . [0146] In the configuration illustrated in FIG. 5 , the scheduler 2308 may send a schedule to each of the affected source switch modules and intermediate switch modules (e.g., source switch module 522 B 2 , first intermediate switch module 522 A 2 and second intermediate switch module 522 A 4 ) via the switch module 522 E 4 to which the master controller 540 is connected. From the perspective of the switch module 522 E 4 to which the master controller 540 is connected, the master controller 540 may appear to be a data source and the schedules may appear to be data segments with specific destinations (e.g., source switch module 522 B 2 , first intermediate switch module 522 A 2 and second intermediate switch module 522 A 4 ). [0147] FIG. 27 illustrates steps in a first-order vacancy matching process (step 2610 ). The scheduler 2308 begins the process by initializing the first number of allocable time slots (step 2702 ). The scheduler 2308 may then select a first-order route from the first-order route set (step 2704 ), perhaps according to a pre-determined policy based on the systematic transit delay value associated with each first-order route in the first-order route set. A first-order vacancy match is then sought (step 2707 ) by the scheduler 2308 for the first rotator and the second rotator specified in the selected route. Where it is determined (step 2708 ) that a first-order vacancy match has been found, the first number of allocable time slots is increased (step 2710 ) and it is determined (step 2712 ) whether all routes in the selected route set have been considered. Where it is determined (step 2708 ) that a first-order vacancy match has not been found, the determination (step 2712 ) of whether all routes in the selected route set have been considered is made without increasing the first number of allocable time slots. [0148] Where it is determined that all routes in the first-order route set have been considered, the process is considered complete and the first number of allocable time slots is returned to the scheduling method of FIG. 26 . However, where it is determined that all routes in the first-order route set have not been considered, another route is selected (step 2704 ) and a first-order vacancy match is once again sought (step 2707 ). [0149] FIG. 28 illustrates steps in a second-order vacancy matching process (step 2616 ). The scheduler 2308 begins the process by initializing the second number of allocable time slots (step 2802 ). The scheduler 2308 may then select a second-order route from the second-order route set (step 2804 ), perhaps according to a pre-determined policy based on the systematic transit delay value associated with each second-order route in the second-order route set. A second-order vacancy match is then sought (step 2807 ) by the scheduler 2308 for the first rotator, the second rotator and the third rotator specified in the selected route. Where it is determined (step 2808 ) that a second-order vacancy match has been found, the second number of allocable time slots is increased (step 2810 ) and it is determined (step 2812 ) whether all routes in the selected route set have been considered. Where it is determined (step 2808 ) that a second-order vacancy match has not been found, the determination (step 2812 ) of whether all routes in the second-order route set have been considered is made without increasing the second number of allocable time slots. [0150] Where it is determined that all routes in the second-order route set have been considered, the process is considered complete and the second number of allocable time slots is returned to the scheduling process of FIG. 26 . However, where it is determined that all routes in the selected route set have not been considered, another second-order route is selected from the second-order route set (step 2804 ) and a second-order vacancy match is once again sought (step 2807 ). If the total number of allocable time slots is greater than zero but less than the required number of time slots (F) per scheduling time frame, the scheduler 2308 may admit or reject the connection request according to a preset criterion. [0151] Advantageously, the two-dimensional circulating switch 500 of FIG. 5 may be considered robust in that the two-dimensional circulating switch 500 may continue to function under partial component failure. For instance, where the route from source switch module 522 B 2 to destination switch module 522 E 4 over the route that includes path-set 801 and path-set 802 ( FIG. 8 ) is in use by the source switch module 522 B 2 and the intermediate switch module 522 E 2 fails, an alternate first-order matching route may be available over path 803 and path 804 . Additionally, as many as 48 alternate second-order matching routes may be available to connect the source switch module 522 B 2 to the destination switch module 522 E 4 . [0152] Further advantageously, the capacity of the two-dimensional circulating switch may be expanded without service interruption. Entire new one-dimensional circulating switches may be added to expand the capacity of a given two-dimensional circulating switch. [0153] Still further, the two-dimensional circulating switch may be adapted to handle many different services, including those services characterized by packets, bursts, Time Division Multiplexed (TDM) frames, Synchronous Optical Network (SONET) frames, channels, etc. Such adaptation may be accomplished by appropriately configuring the switch modules 522 . [0154] It should be noted that a one-dimensional circulating switch may be defined by only a single rotator, but that the number of rotators defining a one-dimensional circulating switch is limited only by the capacity of each switch module as described in Applicant's U.S. patent application Ser. No. 10/780,557 referenced above. [0155] The capacity of a two-dimensional circulating switch may be expanded to several Petabits per second. For example, using one-dimensional circulating switches each having 512 switch modules, and with each one dimensional circulating switch, primary or secondary, using four rotators of dimension 512×512 each, the total number of switch modules would be 262144. With switch module having 11 dual ports, including three access dual ports (a dual port includes an input port and an output port) interfacing with traffic sources and sinks, four inner dual ports interfacing with four rotators of a primary one-dimensional circulating switch, and four inner ports interfacing with four rotators of a secondary one-dimensional circulating switch, the total number of dual access ports would be 786432. With a port capacity of 10 Gb/s in each direction (10 Gb/s input and 10 Gb/s output), the total access capacity (the throughput) of the two-dimensional circulating switch would be 7.86 Petabits per second. [0156] Other modifications will be apparent to those skilled in the art and, therefore, the invention is defined in the claims.

A one-dimensional circulating switch may be defined by connections between several switch modules and one or more temporal cyclic rotators. Where a switch module that is part of a first one-dimensional circulating switch is also connected one or more temporal cyclic rotators that define a second one-dimensional circulating switch, a two-dimensional circulating switch is formed. A two-dimensional circulating switch is flexible and may scale to capacities ranging from a few gigabits per second to multiple Petabits per second.

BACKGROUND OF THE INVENTION [0001] High energy x-ray tubes are used in medical device applications to provide an x-ray source. The materials in the x-ray tube are subject to high temperatures during the operation of the x-ray tube. The x-rays generated by the x-ray tube are directed out of a window toward a target such as portion of a patient. The x-ray tube is subject to high temperatures when the x-ray tube is generating x-rays and then cools. A heat shield may be secured to a portion of the x-ray tube to shield the window from backscattered electrons. SUMMARY OF THE INVENTION [0002] A fastening assembly includes a fastener having a head with an underside and an elongated shaft extending therefrom. The fastener constructed of at least one of a refractory metal and a superalloy. A washer includes a body with an upper surface and an opposing lower surface which defines opening portion for receiving the elongated shaft of the fastener therethrough. The upper surface of the washer forms diffusion bonds with the underside of the head of the fastener when the washer and the fastener are held in contact at temperatures in excess of 500° C. [0003] In another embodiment, an assembled structure suitable for use at high temperatures includes at least two bolts. Each bolt includes a head with an underside and an elongated shaft extending from the underside. Each bolt is constructed of at least one of a refractory metal and a superalloy. A washer includes a body with an upper surface and an opposing lower surface defining at least a first aperture and a second aperture respectively receiving the shaft of at least the first bolt and the shaft of the second bolt. The assembled structure also includes a first high temperature material into which the at least two bolts have been threaded and a second high temperature material which has been secured to the first high temperature material by the at least two bolts. The underside of the head of each bolt has mechanically measurably diffusion bonded to the upper surface of the washer. [0004] In yet another embodiment a process for securing a heat shield for the insert window of a high energy X-ray tube to a collector for back scattered electrons includes providing a fastener having a head with a member extending therefrom, the member comprising at least one of a refractory metal and a superalloy. The process also includes providing a washer having a body with an upper surface and an opposing lower surface which defines at least a first opening for receiving the member of the fastener therethrough. The process further includes passing the fastener through the first opening of the washer and securing the member to a threading the fastener into a first member. The process also includes subjecting the assembled structure to a high temperature to cause the fastener to diffusion bond to the washer to a mechanically detectable degree. BRIEF DESCRIPTION OF THE DRAWINGS [0005] FIG. 1 is a schematic of the internal structure of the insert of a high energy X-ray tube with a rotating anode target. [0006] FIG. 2 is a perspective view of a backscatter electron collector with a heat shield bolted to it across the X-ray exit path. [0007] FIG. 3 is a front elevation view of a backscatter electron collector with a heat shield bolted to it. [0008] FIG. 4 is a cross section of a backscatter electron collector with a heat shield bolted to it. [0009] FIG. 5 is a cross section of the portion of a backscatter electron collector where a heat shield has been bolted to it. [0010] FIG. 6 is a front elevation of a heat shield in position to be bolted to a collector. [0011] FIG. 7 is a photomicrograph of a cross section of the joint between the underside of a bolt head and a washer after diffusion bonding. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0012] Referring to FIG. 1 , the internal structure 10 of the insert of a high energy X-ray tube has a rotating anode target 40 mounted on a bearing 30 that is supported by a frame 20 . A cathode 100 in a housing 90 supplies electrons which are accelerated by a high electrical potential and strike a focus area on the target 40 causing the generation of X-rays. These X-rays are directed out of a window 60 constructed of a material translucent to X-rays such as beryllium. However, not all of the accelerated electrons are absorbed by the target 40 and a collector 80 is provided to absorb many of these backscattered electrons. Some of these backscattered electrons follow the path of the exiting X-rays and strike the window 60 . This subjects the window 60 to thermal stresses that can reduce the operating life of the insert. The window 60 is sealed to the envelope of the insert to maintain an effective vacuum inside the insert. However, the heating and cooling of the window 60 , as the X-ray tube is cycled through a duty cycle of generating X-rays and then being off until the next exposure is called for, causes the window to expand and contract. This expansion and contraction is not precisely matched to that of the wall of the envelope for various reasons and the mismatch causes stress upon the seal that over time can cause it to fail. The heating of the window 60 is ameliorated by interposing a heat shield 50 in the path of backscattered electrons to absorb some of them that would otherwise strike the window 60 . The heat shield is constructed of a material, such as graphite, beryllium, or titanium, which can absorb these backscattered electrons without unduly interfering with the transmission of X-rays. This material, for instance graphite, may lack the ability to undergo much elastic compression and, in fact, may be subject to crushing upon tightening of the bolts 70 , 72 . Heat shield 50 is constructed of a material that is capable of operating in a high temperature environment such as over 500° C. and has high heat conduction. Heat shield 50 absorbs heat and radiates it out. Heat shield 50 is made with graphite or another material that permits x-rays to be transmitted therethrough minimizing effects on image quality as compared to a heat shield made of metals that deflect and/or absorb x-rays compromising image quality. The heat shield is secured in place by bolts 70 and 72 that are threaded in to the collector 80 . The bolts 70 and 72 and the collector 80 are constructed of a material, such as a molybdenum alloy like TZM (A well known and commonly used alloy of titanium, zirconium and molybdenum), or other refractory metals that are used at operating temperatures in excess of about 500° C. and in a temperature region between 500° C. and 1500° C. Other materials for the bolts that have similar operating characteristics to the refractory metals as noted herein are also contemplated. For example, austenitic nickel-chromium based superalloys or other high temperature superalloys are contemplated as well. Superalloys may include certain nickel alloys. Of course other temperature ranges are also contemplated. In one embodiment the operating temperatures will be excess of about 400° C., and in another embodiment the operating temperatures will be in excess of about 300° C. In a further embodiment the operating temperature will be between 300° C. and 1500° C. and in another embodiment the operating temperature will be between 400° C. and 1500° C. In still another embodiment, the operating temperature range will be between 600° C. and 1200° C. In another embodiment the operating temperature range will include the range of 700° C. and 900° C. All of the temperature notations used herein are in degrees Celsius. [0013] Referring to FIG. 2 , the heat shield 50 has been bolted to an appropriate place on the collector 80 with bolts 70 and 72 . The bolts 70 and 72 have been passed through a common washer 110 that has an aperture for the elongated shaft of each bolt. However other types of washer designs are also contemplated, such as a washer that has a region with a first opening and a second opening, where the openings are connected to one another, separated from one another and/or are completely surrounded by the washer body or only partially surrounded by the washer body. The head of each bolt has been snugged against the washer 110 by threading the bolt into the collector 80 such that the underside of the head is in firm contact with the top surface of the washer 110 . The bottom surface of the washer 110 then abuts the top surface of the heat shield 50 . The bottom surface of the heat shield 50 in turn abuts the collector 80 . The washer 110 is constructed of a material, such as nickel, cobalt or iron or alloys thereof, that provide diffusion bonds to the underside of the heads of the bolts 70 and 72 under appropriate conditions of time and temperature such as temperatures in excess of about 500° C. and times in excess of thirty minutes. Of course other temperature and time combinations that provide diffusion bonds are contemplated. In one embodiment the washer material is different than the bolt material. However, the washer material may be the same as the bolt material if diffusion bonds are created as described herein. In an alternative embodiment an intermediate material may be placed between the washer and the bolt to assist in the creation of a diffusion bond. In yet another embodiment, a material may be provided on the threaded portion of the bolts and/or within the threaded region of the collector to provide a diffusion bond between the threaded region of the bolts and the threaded region of the collector. In one embodiment nickel is the intermediate material applied to the threads of the bolts and/or the collector. Other materials that would provide for diffusion bonds between the bolts and collector are contemplated in this alternative embodiment. The inclusion of diffusion bonds between the bolt threads and the threads of the collector provide for additional torque retention between the bolts and collector and make removing the bolts from the collector more difficult if there is a need to repair the x-ray tube structure that requires removal of the bolts. In another embodiment described herein no diffusion bonds are created between the threaded portion of the bolt and the threaded portion of the collector to make removal of the bolts from the collector easier. [0014] Referring to FIG. 3 , the heat shield 50 is bolted to the collector 80 by bolts 70 and 72 whose elongated shafts pass through apertures in washer 110 that has an area of weakness 112 in the region between the two apertures. When the undersides of the heads of the two bolts 70 and 72 have become bonded to the upper surface of the washer 110 , this allows one of the bolts to be retracted by fracturing the washer 110 through this area of weakness 112 . The area of weakness 110 is shown as the mere elimination of some of the web of the washer 110 but other means of enhancing frangibility such as scoring could also be used. In the absence of this area of weakness 112 , the retraction of either bolt 70 or 72 is only possible if that bolt's diffusion bond with the washer 110 is broken. It is mechanically not possible to rotate a single bolt so as to retract it so long as both bolts are attached to the washer 110 and washer is unfractured. The washer is not free to rotate with the bolt being retracted because the other bolt has been passed through it and is still engaged in the threads of the collector 80 . [0015] Referring to FIG. 4 , the heat shield 50 is held in position across the channel 120 through which X-rays pass after being generated by the collision of accelerated electrons with the rotating anode target 40 shown in FIG. 1 . It is held in position by bolt 70 that is threaded into the collector 80 . Neither the washer 110 nor the other bolt 72 is shown in this view. [0016] Referring to FIG. 5 , the elongated shaft 73 of the bolt 70 passes through an aperture in the washer 110 and through the heat shield 50 . The threads 77 of the bolt 70 engage the threads 82 of the collector 80 . The bolt 70 is tightened by threading its threads 77 into the threads 82 of the collector 80 until the underside 75 of its head 71 come in contact with the top surface 111 of the washer 110 . If the heat shield 50 is constructed of a material, like graphite, that does not undergo much elastic compression, it is difficult to secure the bolt 70 against loosening by tightening it so far as to cause elastic compression on the washer. Heat shield 50 may be formed of other materials that provide similar x-ray transmission, electron absorption and high surface temperature to graphite. In other environments washers are adjacent to rigid materials that resist compression and so tightening of the bolt causes elastic compression forces that press against the head of the bolt and providing resistance to its retraction. The bolts 70 and 72 are subject to being loosened by vibration and thermal stresses such as not seeing precisely the same temperature profile as the portion of the collector into which they are threaded and not experiencing the same expansion and contraction as the heat shield 50 through which they are passed. However, at the service temperatures typically seen by the collector 80 and the bolts 70 and 72 , the typical materials of construction, such as molybdenum or molybdenum alloys, do not appreciably diffusion bond across their respective threads 82 and 77 . To address this situation special steps are taken so that the undersides of the heads of theses bolts, such as the underside 75 of the head 71 of bolt 70 , become diffusion bonded to the upper surface 111 of the washer 110 . In particular, the material of the washer 110 is selected so that it will readily diffusion bond to the underside of the bolt head and temperatures are used in manufacture to cause such diffusion bonding. As is readily apparent from FIG. 2 and FIG. 3 , this means that these bolts can only be loosened by fracture of the washer 110 through its region of weakness 112 or fracture of the diffusion bonds to one of the bolts 70 and 72 . In one embodiment the region of weakness 112 will break before the diffusion bonds break between the bolts and washer. [0017] Referring to FIG. 6 , the washer 110 has a region of weakness 112 between its two apertures 113 for bolts that secure the heat shield 50 to the collector 80 . A substantial amount of the material of the washer has been removed to facilitate its fracture upon the application of a reverse torque to a bolt which has diffusion bonded to the washer 110 . [0018] Referring to FIG. 7 , diffusion bonding has occurred between the top surface 111 of the washer 110 and the underside 75 of the head 71 of a bolt after they were placed adjacent to each other and subjected to 1100° C. for 30 minutes. [0019] Diffusion bonding of the bolts to the washer may be done as an independent operation or as a part of the manufacturing of the overall structure. In either case the bolts are passed through apertures in the same washer and threaded into a first high temperature material in such a way as to secure a second high temperature material to the first. One embodiment is when bolts are threaded into the collector of an X-ray tube constructed of a first high temperature material to secure a heat shield constructed of a second high temperature material to the collector. Typically the bolts pass through the second high temperature material after first passing through the washer and before being threaded into the first high temperature material. The bolts are threaded into the first high temperature material until the undersides of their heads contact the top surface of the washers. Then the bolts and washer are subjected to an elevated temperature for a sufficient time to cause mechanically detectable diffusion bonding between the bolts and the washer, i.e. diffusion bonding which can sustain a measurable mechanical load. The mechanically detectable diffusion can be detected and measured with a torque wrench. A typical bonding process for a nickel washer and molybdenum alloy bolts is about 1100° C. for about 30 minutes. This bonding process may be done as part of the procedure for the manufacture of an X-ray tube. The insert portion of an X-ray tube is built up. As part of this build up a collector is installed which has tapped holes. A heat shield is attached using bolts which pass through a common washer which has a separate through aperture for each bolt. The bolts are passed through the heat shield and into the tapped holes in the collector. The bolts are then drawn at least snug-tight against the washer. The vacuum envelope which is typically the outer boundary of the insert is then completed. Processing of the insert results in the collector being exposed to elevated temperatures, resulting in the diffusion bonding between the washer and bolt. The diffusion bonding provides a structure that is suitable for use in a vacuum environment and will not be the source of outgassing which would contaminate the vacuum. The diffusion bonding provides both adequate torque retention to ensure the bolts remain secured within the structure at the high temperature environment as well as ensuring that the means used to provide a secondary torque retention over the use of the threads do not contaminate the vacuum environment when the structure is at temperatures at or above 500° C. or as otherwise noted above herein. The diffusion bonding of the bolts and washer as described herein does not introduce chemicals into the vacuum environment at operating temperature above 500° C. or as otherwise noted above herein. [0020] The diffusion bonding may be weak enough to allow the removal of the bolts by fracture of these bonds but alternatively the washer may be provided with a region of weakness between adjacent apertures that allows the removal of a bolt by applying a reverse torque to the bolt head which causes a fracture of the of the washer through this region. This alternative provides fairly reproducible control of the force necessary to remove a bolt, particularly if the weakness is provided by eliminating some of the material of the washer. [0021] It may be of value to be able to readily remove bolts that have diffusion bonded to a washer. This facilitates to ability to do rework in the construction of an X-ray tube. If needed rework were to require the removal of the heat shield from the collector the ability to remove its securing bolts by fracturing the retaining washer through its area of weakness would be of value. It would allow one to remove the heat shield with less chance of damage. The bolts as described herein at the operating temperature retain their structural integrity in such a manner that the shape of the bolts are not compromised to the extent that the torque between the bolts and collector is not completely degraded. The bolt material provides for resistance to creep at temperatures over 500° C.; good surface stability; and/or corrosion and oxidation resistance. The materials of the bolts being selected to maintain sufficient pretension of the bolt and collector of a predetermined value. [0022] Although the present disclosure has been described with reference to example embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the claimed subject matter. For example, although different example embodiments may have been described as including one or more features providing one or more benefits, it is contemplated that the described features may be interchanged with one another or alternatively be combined with one another in the described example embodiments or in other alternative embodiments. The term metal or metals as used herein with contemplates and includes alloys of the same metal. In another embodiment washer may include a member extending therefrom that is prohibits rotation of the washer by engaging a feature of a surface of the member that the washer is adjacent to. In this manner, the washer may only be removed by fracturing the washer body and or completely removing the bolt or other fastener from the opening of the washer. Because the technology of the present disclosure is relatively complex, not all changes in the technology are foreseeable. The present disclosure described with reference to the example embodiments and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements.

A fastening assembly includes a fastener having a head with an underside and an elongated shaft extending therefrom. The fastener constructed of at least one of a refractory metal and a superalloy. A washer includes a body with an upper surface and an opposing lower surface which defines opening portion for receiving the elongated shaft of the fastener therethrough. The upper surface of the washer forms diffusion bonds with the underside of the head of the fastener when the washer and the fastener are held in contact at temperatures in excess of 500° C.

BACKGROUND OF THE INVENTION 1. Field or the Invention The present invention relates to a semiconductor device and a method or producing the same and, more particularly, to a semiconductor having a plastic package and a method of producing it. 2. Description or the Related Art FIG. 30 shows a configuration of the semiconductor device having a plastic package according to the prior art. A semiconductor chip 32 is carried on the die-pad 31, and a plurality of inner leads 34 are disposed on the peripheral area of the die-pad 31. As shown in FIG. 31, the inner leads 34 and corresponding electrodes pads 33 are connected by wire-bonding by means of respective metallic fine-wires 35. Each inner lead 34 is integrally connected with a corresponding outer lead 37. The die-pad 31, the semiconductor chip 32, the inner leads 34, and the metallic fine-wires 34 are sealed in a body 36 of the package made or an epoxy resin and the like in a manner such that the outer leads 37 extend to the outside of the body 36. Each outer lead 37 is bent along the shape of the body 36 of the package. A description of the method of wire-bonding is given below. Commonly, a gold wire having a diameter from 25 to 30 μm is employed as the metallic fine-wire 35. An end portion of the metallic fine-wire 35 being run through a capillary chip (not shown in FIGS. 30 and 31) is heated and melted to form a round ball. A metallic-diffusion bonding between the ball and the electrode pad 33 is executed by applying load, heat, and ultrasonic energy to the ball, and then pressing it onto the electrode pad 33 of the semiconductor chip 32 by means of the capillary chip. Subsequently, the extra amount or the metallic fine-wire 35 is fed out from the capillary chip, and then the metallic fine-wire 35 is pressed onto the inner lead 34, thus enabling metallic-diffusion bonding between each metallic fine-wire 35 and inner lead 34. The wire bonding is achieved by the above mentioned method; however, the following conditions must be satisfied for accomplishing completely reliable bonding: 1. The electrode pads 33 must be disposed on a peripheral area of the surface of the semiconductor chip 32 to prevent contact between the metallic fine-wire 35 and the edge portion of the semiconductor chip 32. 2. The distance between each electrode pad 33 and the semiconductor chip 32 must be 0.5 mm or more. 3. The clearance between each inner lead 34 and the die-pad must be 0.2 mm or more to insulate them from each other. 4. Each inner lead must have a length of at least 0.2 mm for bonding of the metallic fine-wire 35. In order to fulfill all of the above requirements, the thickness of the body 36 of the package surrounding the semiconductor chip 32 must be at least 0.5 mm. In accordance with the contemporary trend of high density integration and advanced functions of an IC device, the size of the semiconductor chip is becoming larger than before, whereas downsizing is required with respect to the package size of a semiconductor device in order to comply with demands for downsizing and miniaturizing of electronic equipment. As described above, it is required of the semiconductor device having the conventional configuration to have a thickness of 0.5 mm or more in a body of the package surrounding the semiconductor chip to ensure the reliability of the device; however, there is a drawback that a large semiconductor chip cannot be accommodated in a downsized package-body. SUMMARY OF THE INVENTION In order to overcome the above described problems, the present invention is aimed at providing a semiconductor device which can accommodate a large semiconductor chip in a downsized package-body without impairing its reliability. Another object of the present invention is to provide a method of manufacturing the above described semiconductor device. According to one aspect of the invention, there is provided a semiconductor device which comprises: a semiconductor chip having a first surface and a second surface at opposite sides, and also having a plurality of electrode pads linearly disposed substantially on a longitudinal center line of the first surface or the semiconductor chip: a die-pad bonded to the second surface of the semiconductor chip to support the chip, and having a smaller area than has the semiconductor chip; at least one common inner-lead situated above the first surface of the semiconductor chip, and disposed substantially parallel to the longitudinal center line of the semiconductor chip; a plurality of inner leads disposed in an area adjacent to the corresponding electrode pad of and above the first surface of the semiconductor chip; a plurality of metallic fine-wires electrically connecting the plurality or electrode pads with a common inner-lead and a corresponding inner lead; a body of a resin package sealing the semiconductor chip, the die-pad, the common inner-lead, the plurality or inner-leads, and the plurality of metallic fine-wires; common outer-leads each integrally connected with the common inner-lead, and each exposed outside of the body of the resin package; and a plurality of outer leads each integrally connected to the common inner-lead, and each exposed to the outside of the body or the resin package wherein .[.,.]. a gap between the first surface of the semiconductor chip and a geometric plane determined by the bottom surfaces of the common inner-lead and of the plurality or inner leads is .[.0.1 mm or more and 0.4 mm or less, and the gap is.]. filled with the resin which forms part of the body of the resin package. According to another aspect of the invention, there is provided a method of producing a semiconductor device comprising the steps of: preparing a semiconductor chip which has a first surface and a second surface at opposite sides, and also has a plurality of electrode pads linearly disposed on substantially longitudinal center line of the first surface of the semiconductor chip; placing the semiconductor chip on a first lead frame where a die-pad having a smaller area than the semiconductor chip is formed; bonding the die-pad of the first lead frame and a second surface of the semiconductor chip; positioning a second lead frame, formed by at least one common inner-lead and a plurality of inner leads disposed adjacent to the common inner-lead, above the first surface of the semiconductor chip so as to maintain a gap between the first surface of the semiconductor and a geometric plane determined by the bottom surfaces of the common inner-leads of the plurality of inner leads .[.to be 0.1 mm or more and 0.4 mm or less.].; wire bonding the plurality of electrode pads of the semiconductor chip to corresponding inner leads; and sealing the semiconductor chip, the die-pad, the common inner-leads, and the plurality of inner-leads by filling a resin between the first surface of the semiconductor chip and the second lead frame formed by the common inner-lead and the plurality of inner leads. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view illustrating a semiconductor device relating to a tint embodiment of the present invention. FIG 2 is a sectional view generally taken along the line .[.A--A.]. .Iadd.2--2 of FIG. 1. FIG. 3 is a schematic illustration showing a wire-bonding process. FIG. 4 is a schematic illustration showing a wire-bonding process. FIG. 5 is a schematic illustration showing a wire-bonding process. FIG. 6 is a chart showing a relationship between gap d, which represents a clearance between a first surface of a semiconductor chip and an inner lead, and the pull-strength of the inner lead. FIG. 7 is a chart showing a relationship between a gap, which represents a clearance between the first surface of the semiconductor chip and the inner lead, and damage which occurred to the semiconductor chip. FIG. 8 is a chart showing a relationship between an area-ratio of an insulator to an area of the chip and an occurrence ratio of package cracking. FIG. 9 is a plan view of a first lead frame employed for manufacturing the semiconductor device of the first embodiment. FIG. 10 is a plan view of a second lead frame employed for manufacturing the semiconductor device of the first embodiment. FIG. 11 is a plan view showing the aligned layout of the first lead frame of the FIG. 9 and the second lead frame of the FIG. 10. FIG. 12 is a plan view of a modification of the first embodiment. FIG. 13 is a plan view of a modification of the first embodiment. FIG. 14 is a sectional view of a further modification of the first embodiment. FIG. 15 is a plan view of a semiconductor device which relates to the second embodiment. FIG. 16 is a sectional view generally taken along the line .[.B--B.]. .Iadd.2--2 of the FIG. 15. FIG. 17 is a plan view of a semiconductor device which relates to the third embodiment. FIG. 18 is a sectional view generally taken along the line .[.C--C.]. .Iadd.18--18 of FIG. 17. FIG. 19 is a sectional view of a semiconductor which relates to the fourth embodiment. FIG. 20 is a plan view of a semiconductor which relates to the fourth embodiment. FIG. 21 is a chart showing the relationship between a bonding-possibility and the shape of the inner lead of a semiconductor device of the prior art. FIG. 22 is a chart showing the relationship between bonding-possibility and the shape of the inner lead of a semiconductor device of the present invention. FIG. 23 is a sectional view of a semiconductor which relates to a fifth embodiment. FIG. 24 is a sectional view of a modification of the fifth embodiment. FIG. 25 is a sectional view of a portion of a semiconductor device which relates to a sixth embodiment. FIG. 26 is a perspective view of a portion of a semiconductor device which relates to a seventh embodiment. FIG. 27 is a sectional view of a portion of a semiconductor device which relates to a eighth embodiment. FIG. 28 is a perspective view of a portion of a ninth embodiment. FIG. 29 is a perspective view of a modification of the ninth embodiment. FIG. 30 is a partially cut-away perspective view of a semiconductor of the prior art. FIG. 31 is an enlarged view of a portion of the semiconductor device of the prior art. DESCRIPTION OF THE PREFERRED EMBODIMENTS A description of the preferred embodiments of the present invention will now be given in conjunction with the accompanying drawings. First Embodiment FIG. 1 and FIG. 2 are a plan view and a sectional view, respectively, showing a first embodiment of a semiconductor device according to the present invention. A semiconductor chip 2 is formed in a substantially rectangular shape, and has a first surface 2a on which a circuit is formed and also has a second surface 2b opposite the first surface 2a. On the first surface 2a of the semiconductor chip 2, a plurality of electrode pads 3 are linearly disposed adjacent the longitudinal center line of the semiconductor chip 2. The second surface 2b of the semiconductor chip 2 is bonded on a die-pad 1. The die-pad 1 has an area smaller than that of the semiconductor chip 2, and more particularly, is bonded to the chip 2 in a manner such that lateral sides of the die-pad do not outwardly extend from the longitudinal lateral sides of the semiconductor chip 2. Above the first surface 2a of the semiconductor chip 2, two common inner-leads 8 and 9 are disposed substantially parallel to the longitudinal center-line of the surface 2a and lie between the plurality of the electrode pads 3, and, at the same time, a plurality of inner leads 4 is disposed at a right angle to these corn/non inner-leads leads 8 and 9 outside of the respective common inner-leads adjacent corresponding electrode pads 3. The common inner-leads 8 and 9 are inner leads for supplying supply voltage and for grounding, respectively. Of the plurality of the electrode pads 3, those which are connected for performing the functions of the semiconductor device are selectively connected electrically to either one of the common inner-leads 8 or 9 or to one of the plurality of the inner leads 4 via respective metallic fine-wires 5. Common outer leads 10 and 11 are integrally connected to the common inner-leads 8 and 9, respectively. The other outer leads 7 are connected with corresponding inner leads 4. Consequently, the die-pad 1, the semiconductor chip 2, the con%mon inner leads 8 and 9, the plurality of inner leads 4, and the plurality of metallic fine-wires 5 are sealed in a body 6 of a resin package made of an epoxy resin or the like, in which the common outer-leads 10 and 11 and the plurality of the outer leads 7 are partially exposed to the outside. A gap d between the first surface 2a of the semiconductor chip 2 and a geometric plane formed by the bottom surface of the common inner-leads 8 and 9 and the plurality of the inner leads 4 is 0.1 mm to 0.4 min. As shown in FIG. 2, the body 6 of the resin package even fills this gap. Therefore, no insulation tape or the like is inserted in this gap. A description of a wire-bonding process for a connection between each electrode pad 3 on the semiconductor chip 2 and each of the plurality of inner leads 4 by means of the metallic fine-wire will be given below in conjunction with FIGS. 3 through 5. Commonly, gold wire having a diameter ranging from 25 μm to 30 μm is used as the metallic fine-wire 5. A point of the metallic fine-wire 5 disposed so as to pass through a capillary chip 42 is heated and melted to form a round ball 43 (shown in FIG. 3). Then, the ball 43, to which a load, heat, and ultrasonic energy are applied, is pressed on to the electrode pad 3 of the semiconductor chip 2 by means of the capillary chip 42. Accordingly, the metallic junction between the metallic ball 43 and the electrode pad 3 is accomplished. In the next step, the metallic fine-wire is fed out from the capillary chip 42 (shown in FIG. 4), and load, heat. and ultrasonic energy are applied to press the metallic fine-wire 5 on the inner lead 4 (shown in FIG. 5) for forming a metallic diffusion junction between the metallic fine-wire 5 and the inner lead 4. An experiment for measuring the pull strength of the metallic fine-wire is executed by disposing the inner lead above a circuit-carrying surface of a 4M-DRAM semiconductor chip of the SOJ-type (small outline J-Bend-type) by providing the gap d therebetween, and then bonding the metallic fine-wire onto the inner lead. The result of the experiment is shown in a chart of FIG. 6, wherein the greater the gap d between the semiconductor chip and the inner lead, the lower the pull strength, and eventually the metallic fine-wire cannot be bonded when the gap d exceeds 0.6 mm or more. In this case, so-called stitch peeling occurs. Meanwhile, in the above experiment. the frequency of an indentation or damage, on the first surface of the chip and caused by the point of the inner lead during a bonding operation, was measured. The result of this experiment is shown in FIG. 7. The measurement of the frequency of the damage is determined by etching the bonded area of the chip with phosphoric acid and observing the area with an optical microscope to count the number of etch pits, indicating the damage per unit area. As a result, at least one example of damage was observed when the gap between the semiconductor chip and the inner lead was 0.1 mm or less and 0.4 mm or more, and no damage was observed when the gap ranged between 0.1 mm and 0.4 min. Accordingly, it is desirable for the inner lead to maintain the gap d between the circuit-carrying surface and the inner lead in a range between 0.1 mm and 0.4 mm in order to achieve stable stitch-bonding without damaging the semiconductor chip. In the first embodiment of the semiconductor device, a ratio of an area S 2 of the semiconductor chip 2 to an area S 1 of a plane section of the body 6 of the resin package S 2 /S 1 was successfully raised to approximately 80%, although the ratio S 2 /S 1 of the conventional semiconductor chip was approximately 60%. Accordingly, in the embodiment of the present invention, the ratio S 2 /S 1 is markedly increased such that a large semiconductor chip can be accommodated in a small package. Meanwhile, for the SOJ package used in the 4M-DRAM, another experiment was executed to observe packing cracking in the semiconductor device. This SOJ package has the same configuration as that of the first embodiment of the device shown in FIGS. 1 and 2, except for a tape-shaped electrical insulator inserted between this circuit-carrying surface of the semiconductor chip and a geometric plane formed by the common inner-leads and the plurality of the inner leads. This semiconductor is subject to preliminary treatment and, then a solder dip to observe any packing cracking. As the preliminary treatment, moisture was applied to the semiconductor device at 85° C. and 85% R. H. By varying the ratio of the area of the tape-shaped insulator to that of the semiconductor, the occurrence of the package cracking was observed. The results are shown in FIG. 8 wherein the ratio of the occurrence of package cracking with insulating tape present to the occurrence of package cracking without insulating tape present is indicated by a value standardized to an area-ratio of zero, i.e., without any tape-shaped insulator between the chip and the leads. As is shown in FIG. 8, the higher the occupancy ratio of the insulator, the higher the occurrence of package cracking. Package cracking causes deterioration of moisture-resistance. When the occupancy ratio of the insulator increases, the moisture-resistant character of the semiconductor device deteriorates. In the present invention, however, the tape-shaped insulator is not placed between the semiconductor chip and the inner leads; hence, a packaged semiconductor device having a superior moisture-resistant character is obtained. The semiconductor device of the first embodiment of the present invention can be manufactured by the following method, for instance. First, the semiconductor chip 2 is carried on a first lead frame 12 where the die-pad 1 is formed as shown in FIG. 9 to bond the second surface 2b of the semiconductor chip 2. Then, a second lead frame 13 shown in FIG. 10 is positioned above the first surface 2a of the semiconductor chip 2 as shown in FIG. 11. The plurality of the inner leads 4, the common inner-leads 8 and 9, the plurality of the outerleads 7, and the common outer-leads 10 and 11 are present in the second lead frame 13. The second lead frame is positioned such that a gap between the first surface 2a of the semiconductor chip 2 and the second lead frame 13, in which the common inner-leads 8 and 9 and the plurality of the inner leads 4 are formed, is 0.1 mm to 0.4 mm. Under the above circumstance while maintaining the gap, the wire-bonding process is executed and, in addition, the resin molding is accomplished, thus the manufacturing of the semiconductor device which is shown in FIG. 1 and FIG. 2 is accomplished. As is shown in FIG. 12, the common inner-leads 14 and 15 can be disconnected at their respective centers. Due to this configuration, for instance, exclusive common inner-leads can be provided at each circuit block of the semiconductor chip 2, wherein the length of each common inner-lead is shorter; therefore, the response of the signal passing through the common inner-leads 14 and 15 improves and, at the same time, the floating capacitance of these common inner-leads 14 and 15 is reduced. As shown in FIG. 13, at least one pair of supporting inner-leads 18 and 19 can be connected to each tie-bar 20 from the center of the common inner-leads 16 and 17, which increases the mechanical strength of the common inner-leads 16 and 17 to provide easy bonding and molding. Also, the common inner-leads 21 and 22 can be disposed in a position lower than the plurality of the inner-leads 4 to make smaller the gap between the first surface 2a of the semiconductor chip 2 and the common inner-leads 21 and 22 as shown in FIG. 14, in which, however, the gap between the common inner-leads 21 and 22 and the first surface 2a of the semiconductor chip 2 must be within the range between 0.1 mm and 0.4 mm. Due to this configuration, a short-circuit between the metallic fine-wire 5 connected to each inner lead 4 and the common inner-leads 21 and 22 can be effectively prevented. Second Embodiment FIGS. 15 and 16 show a second embodiment of the semiconductor device according to the present invention. On a first surface 23a of the semiconductor chip 23, a first pads-group 24 including a plurality of electrode pads 3 are linearly disposed adjacent to the longitudinal center line. Second and third pads-groups 25 and 26 are each linearly disposed along opposite sides of the first pads-group 24. First and second common-inner leads 27 and 28 are disposed above the first surface 23a of the semiconductor chip 23 and, at the same time, between the first pads-group 24 and the second pads-group 25 and also between the first pads-group 24 and the third pad-group 26. In addition, the plurality of the inner leads 4 are disposed above the first surface 23a of the semiconductor chip 23 and, at the same time, beyond the second pads-group 25 or the third pads-group 26 relative to the center of the first pads-group 24. Of the plurality of the electrode pads 3 of the first pads-group 24, pads are selectively connected electrically to the common inner-lead 27 or 28 by means of the metallic fine-wires 5. Likewise, of the plurality of the electrode pads 3 of the second and third pads-groups 25 and 26, pads are selectively connected electrically to the plurality of the inner-leads 4, which are adjacently located, by means of the metallic fine-wires 5. Accordingly, the metallic fine-wires connected to the plurality of the inner leads 4 do not pass over the common inner-leads 27 or 28 as shown in FIG. 16, thus surely preventing the occurrence of a short-circuit. Third Embodiment FIGS. 17 and 18 show a third embodiment of the semiconductor device according to the present invention. A pair of die-pads 29 is disposed beneath the longitudinal ends of the semiconductor chip 2. The chip 2 is supported by the pair of the die-pads 29. Also, each die-pad 29 has a planar projections located between the common inner-leads 8 and 9. Due to this configuration of the third embodiment, manufacturing of the semiconductor device is made possible by using one lead frame 55 which comprises the die-pads 29, the common inner-leads 8 and 9, and the plurality of the inner-leads 4. Fourth Embodiment FIGS. 19 and 20 show a fourth embodiment of the semiconductor device according to the present invention. In the fourth embodiment, the second surface 2b of the semiconductor chip 2 is fixedly bonded to the die-pad 1. The electrode pads 3 on the first surface 2a of the semiconductor chip 2 and the inner leads 4 are connected by respective metallic fine-wires which pass over one of the common inner-leads 8 or 9. The end portion 4A of each inner lead 4 is bent to ground the first surface 2a of the semiconductor chip 2. The die-pads 1, the semiconductor chip 2, the common inner-leads 8 and 9, and the plurality of the metallic fine-wires 5 are sealed in the body 6 of the package made of the epoxy resin and the like such that the plurality of the outer leads 7 are exposed outside of the body 6. Although the area of the die-pad 1 is smaller than that of the second surface 2b of the semiconductor chip 1 as shown in FIG. 19, it is acceptable if the area of the die-pad 1 is larger than that of the second surface 2b. The relationship between acceptable and unacceptable shapes of the inner lead 4 for bonding, if the gap d (designated as hollow distance) between the inner lead 4 and the first surface 2a of the semiconductor chip 2 shown in FIG. 19 is 0.4 mm, is illustrated in FIGS. 21 and 22 of the prior art and the present invention respectively. In these FIGS. 21 and 22, the abscissa and the ordinates represent the length and the width of the inner leads respectively, and the mark 0 or circle indicates an acceptable region for bonding and the other mark X indicates an unacceptable region for bonding. In this case, the thickness of the inner lead was 0.2 mm, and conditions for bonding were ordinary ones. It can be found from FIG. 21 of the configuration of the prior art that an unacceptable region for bonding exists near the center of the lead length ranging between 0.3 mm and 6.0 mm applied in the experiment. Therefore, a restriction must be made when designing the shape of the inner lead. On the contrary, it can be found from FIG. 22 of the present invention that all the region of the length (0.3 to 6.0 mm) and of the width (0.1 to 0.6 mm), where the experimentation was executed, was acceptable for bonding. Furthermore, it has been also recognized from the result of the measurement that the value of the strength of the bonded area is satisfactory in the overall region where the experimentation was executed. When there is a hollow portion under the inner lead 4, there is a defect such that a resonance of the inner lead 4 will occur in response to ultrasonic energy and, thus, some ultrasonic energy is not effectively used for the bonding due to the resonance. Therefore, the metallic fine-wire 5 cannot be bonded because of the shape of the inner lead 4, thus deteriorating the bonding characteristic. This problem can be overcome by the method introduced in the fourth embodiment. Fifth Embodiment In the above mentioned fourth embodiment, the end portion of the inner lead is bent into the shape (gull-wing shape) indicated in FIG. 19 to form a tip-end portion 4A which grounds the first surface 2a of the semiconductor chip 2. However, the same effect can be obtained when the end portion of the inner lead 4 is bent into the shape (the letter-J shape) illustrated in FIG. 23 to form a spoon-end portion 4B which grounds the first surface 2a of the semiconductor chip 2. In addition, as shown in FIG. 24, the end portion of the inner lead 4 can be bent into a multi-step shape to form a tip-end portion 4C. Sixth Embodiment In the foregoing first embodiment of the semiconductor device shown in FIG. 14, the common inner-leads 21 and 22 are disposed in a lower position than the plurality of the inner leads 4 to prevent a short-circuit from occurring between the metallic fine-wires 5 and the common inner-leads 21 or 22. However, thinner common inner-leads 21A and 22A also can be employed as shown in FIG. 25. For example, when the thickness of the inner lead 4 is 0.2 mm, that of the common inner-leads 21A and 22A can be preferably 0.08 mm or more and 0.15 mm or less, most preferably 0.125 mm. In addition, the common inner-leads 21A and 22A can be disposed in a position much closer to the inner leads 4. Seventh Embodiment In the sixth embodiment, thinner common inner-leads 21A and 22A were used; however, as shown in FIG. 26, an insulating film 50 such as polyimide insulating-tape can be adhered to the surface of the common inner-leads 21 and 22, thus providing a configuration in which the metallic fine-wires S can contact the common inner-leads 21 or 22. In the above configuration, the height or the gap between the common inner-leads 21 and 22 and the semiconductor chip 2 can be freely set in a wide range. To enable bonding the metallic fine-wires 5 to the common inner-leads 21 or 22, an opening 51 is provided by locally removing the insulating film where the bonding is to be done. Eighth Embodiment In the sixth embodiment, the thinner common inner-leads 21A and 22A are employed: however, as shown in FIG. 27, a block 52 or the like can be provided on each end portion of the inner leads 4 so as to increase the substantial height or gap of each inner leads 4 to the common inner-leads 21 and 22. Accordingly, a short-circuit between the metallic fine-wires S and the common inner-leads 21 or 22 can be effectively prevented due to this configuration. Ninth Embodiment FIGS. 28 and 29 illustrate a ninth embodiment of the present invention in which a modification is applied to the common inner-leads. In FIG. 28, each corner portion of the common inner-leads 21 and 22, the corner being closer to the adjacent inner lead, is chamfered to form a chamfered portion 53. The chamfered portion 53 can also be provided on the opposite side of the above mentioned corner of the common inner-leads 21 and 22. In addition, in FIG. 29, an area where each metallic fine-wire S gets closer to the common inner-leads 21 or 22, when they are crossing each other, is locally cut out by etching or the like to make thinner a cut-off portion 53. In this configuration, the short-circuit between the common inner-leads 21 or 22 and the metallic fine-wires 5 can be as effectively prevented as in the foregoing eighth embodiment.

A semiconductor device of the present invention accommodates a large semiconductor chip in a downsized package without impairing its reliability. The semiconductor chip is bonded on a relatively small die pad. Common inner leads and a plurality of inner leads are disposed opposite and spaced from the semiconductor chip by a gap ranging from 0.1 mm to 0.4 mm and the gap between the semiconductor chip and the common inner leads and the plurality of inner leads is filled with a resin which forms pan of a resin package.

FIELD OF THE INVENTION This invention pertains to a decorative object for the yard or driveway which converts to a table and seating. BACKGROUND OF THE INVENTION This invention pertains to a convertible ranch wagon which can be turned into a picnic table and bench set. Many people like the idea of having a picnic table available for use not only as a place for eating out of doors, but also as a place where students of the family and others can sit and work or read as the case may be. In the west, from the Rocky Mountains to the Pacific Ocean, people enjoy having wagon wheels as well as an entire covered wagon such as a ranch wagon, as a decorative lawn item. It is an object of this invention to accommodate the desires of people to have a dual function item, by providing a ranch wagon which can be converted for use to a picnic table with benches and then back to a ranch wagon configuration for lawn decoration, all with little or no effort. It is another object of this invention to provide a decorative ranch wagon which can be used as a play area for children, and which is convertible to a picnic bench and seats. It is yet another object to provide a picnic table and bench seating that is easy to set up from a decorative ranch wagon. It is yet another object to provide a covered ranch wagon, which will permit children to play, shielded from the direct sun or rain. It is a still further object to provide a picnic table and bench seats with a covering there over, to protect the users from sun and rain. Other objects of the invention will in part be obvious and will in part appear hereinafter. The invention accordingly comprises the device possessing the features properties and the relation of components which are exemplified in the following detailed disclosure and the scope of the application of which will be indicated in the appended claims. For a fuller understanding of the nature and objects of the invention reference should be made to the following detailed description, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a left front perspective view of the ranch wagon to table and seats apparatus of this invention. FIG. 2 is a left side perspective view thereof. FIG. 3 is a left rear perspective view thereof. FIG. 4 is a view thereof in the open position with the canopy portion missing. FIG. 5 is a right rear perspective view with the canopy portion in place. FIG. 6 is a left side diagrammatic elevational view of this invention without the canopy. FIG. 7 is a left side diagrammatic elevational view of this invention with the canopy. FIG. 8 is a rear elevational diagrammatic view of the apparatus in this invention in the closed position. FIG. 9 is a diagrammatic rear view with the table in open position. FIG. 10 is a diagrammatic end view taken moments subsequent to FIG. 8 with the seats in position. FIG. 11 is a partial diagrammatic view of a wheel assembly 22 and the parts forming same. FIG. 12 is a perspective view of a right side wall and the cleats attached thereto for mounting. FIG. 13 is a bottom plan view of the device of this invention. FIG. 14 is a perspective view illustrating a variant of the canopy portion of this invention. FIG. 15 is a view similar to FIG. 13 taken a few moments later in time with the canopy portion in a raised position. SUMMARY OF THE INVENTION A preferably scaled down version of a preferably canopied ranch wagon, which can easily be converted to a picnic table and opposed bench seating is the basis for this invention. The unit is easy to convert from a decorative object to a functional table and seating, and is easy to convert back to a decorative item again. The first conversion involves removing the side walls and orienting the front and rear walls 180 degrees thereby raising the "wheels", followed by moving the wheels outwardly from a first position to a second position. To return the table and setting to a decorative ranch wagon the steps are reversed. DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, the decorative ranch wagon of this invention is seen from the front. This wagon differs from a real such wagon, in that it is scaled down, and does not differentiate between the front and the rear ends of the wagon. That is, there is no special seat provided, adjacent where the hind ends of the team of horses would be. This first view is arbitrarily set as a front left perspective view. A right rear perspective view is seen in FIG. 3. The second figure, FIG. 2 is a left side elevational view, the right side being a mirror image thereof. Details of the wagon are more easily seen in other figures and will be appropriately discussed. In this view, the decorative item or apparatus 10 is seen. Apparatus 10 includes a wagon portion 11 and a canopy portion 12. The canopy portion 12, and the variant thereof, will be discussed subsequent to the discussion on the wagon portion. Wagon portion 11 includes a main body 13 of a generally rectangular cross section and is formed from four individual interlocking sections and a table portion to be described more fully below. The main body section include a left side wall, 15, and a right side wall 17 and front and rear panels 19, and 21. All of these are releasably connected to each other at 90 degree intervals as will be recited, and the front and rear panels 19, 21 are pivotally connected, preferably hingedly connected, to the table portion, 32. The four sections rest on a table surface of the table portion 32. Thus the table portion includes a table surface 33 which table surface is supported by right and left table sides 39, 41 per FIGS. 6 and 7 and spaced opposed end sills 34 seen in FIGS. 4, 9 and 10. Disposed beneath the table surface 33 are two trios of spaced and aligned axle holders 24. Again reference is made to FIGS. 6, 7 and 13. These axle holders are aligned with the left side and right side walls of the apparatus such that the axles can pass through them in a disposition normal to the end panels as is seen in FIG. 13. The axle holders are also spaced in an equal distance from the front and rear end panels. Each wheel 25 is formed of several components. As seen in FIG. 2, each wheel 25 has a hub 29 from which emanates a plurality of spokes, 31,--here 8 spokes disposed 12.5 degrees apart. Each spoke 31, extends an equal distance to a felloe or rim 27. While no tread or overlay is depicted on the felloe, the use of such is contemplated. Each hub receives the end of an axle 23, which axle is retained by one or more conventional pins, not seen. Reference is made to FIG. 7. Further discussion infra concerning the axles employed with this invention. The attachment of axles to hubs of wagons is deemed conventional in this day and age. If the felloe contained a tread, as it could, it would be termed a "wheel". The discussion now turns to FIG. 6 for a more detailed dissertation about the side walls and the front and rear panels. Thus each side wall 15, 17 is seen to be formed from a plurality of butt-edged boards, such as 2×6 boards, which abut along their length. This plurality is held together by a series of spaced cleats, 35 disposed normal to the abutted boards 37. Preferably the cleats are mounted externally of the space 60 found between the side walls and the end panels, i.e., the area of the table surface 33. The side wall 17 of FIG. 7 is constructed in the exact same manner as side wall 15 found in FIG. 6, and consists of abutted boards or planks 37 and a plurality of cleats 35, all of which terminate vertically prior to table side 39. Each of the two side walls, 15, 17 includes the hasp portion 51 of a chest latch 50. The strike portion is mounted on the end grain of the respective front and rear panels. These chest latches secure the end panels to the side walls. FIGS. 2 and 7 depict what is seen of the side walls 15, 17 external of the wagon per se. In FIG. 12, side wall 17's vertically disposed spaced cleats 35 are seen. These cleats, usually range from 6 to 12 inches in elevation, are screwed to the panel, and serve to retain the generally vertical side walls upon the table surface 33, by being inserted into spaced cleat slots 57 (per FIG. 13) in the table surface 33 of table 32. Reference is now made to FIG. 8, a view of the rear end panel when the panel is in the upward position. The rear panel 21, and its mirror image companion front panel 19, not seen, are each formed from a plurality of abutted varying sized planks which are joined together by attaching each, as by nailing or screwing to a pair or more of spaced straps 49. Typically the straps are flat metal strips, perhaps 1/4 inch thick and predrilled for the passage of nails therethrough. Other materials may be used however. While shown attached to the exterior surface of the planks as seen in the first position, no reason is seen why the straps could not be attached either on the first position interior surface of these planks or on both sides of the planks. Such straps are readily available in the marketplace. Each of the panels 19, 21 when in the decorative or first position, have each of their individual planks lower extremity aligned horizontally. The elevation of each of the outer planks 43, is the greatest. The next inner plank, 45, from both the left and right sides of the panel is preferably of a lesser elevation. These planks 45 may be made shorter than the plank 43 by using a straight cut or they may be made tapered as shown in the figure. The middle planks 45 are also preferably of an even lesser elevation for several reasons. First, the aesthetics of the panel will more closely resemble historic wagons if so constructed. And second, by having the inner planks of shorter elevation, when the panel is inverted and in its second or eating position, as will be seen in FIG. 9, persons sitting at the end of the table will not kick the respective end panel and it will be easier for the owner to grasp the panel for return to the first position, 180 degrees opposed. Preferably as seen in FIGS. 8 and 9, the interior planks 45 are disposed spaced up from the lower extremity of the outer planks 43 and from the next inner planks 45. The cross slot 53 is used also as a hand grasp for turning the respective end panels 19, 21 from decorative position to the eating position. The cross slot 53 is preferably about 2 to 3 inches in elevation. Boards sized 2×6 inches may be utilized for all of the planks. Note also the presence of the chest latch strike 52 on the end grain of the panels for the reason previously mentioned. In this view the table 32's surface 33 and its supports are not recognized. This is because if one inserts his/her fingers into slot 53, the fingers will impact the table 32 on the end grain. The trio of axle holders 24, linearly spaced apart are seen to be mounted to the underside of the table 32. Each axle holder has a throughbore 28 for receipt of an axle 23. Each axle terminates within a hub 29 and extends slightly beyond the hub as is conventional. Each hub is retained in place by a cross pin 30 that fits through each hub retainer 40 attached to the rear of each hub, and which pin 30 passes through both the hub retainer 40 and the axle 23. See FIG. 11. Any other conventional retaining means can also be employed as these wheels 25, while about 2 inches thick for stability, are not meant to rotate. The construction of each of the end panels is the same as these elements 19 and 21, are basically mirror image panels. In FIG. 9, the end panel 19 is shown in the down or eating position. A pair of horizontally spaced door hinges 55 connect the end panel 19 to the end sill 34, which sill is typically a 2×6-inch board such that the end panel can pivot from a stowed upward to a lowered downward position. The hinges or other pivoting member are attached to the respective end panel at a location such that when the end panels are moved to the down position, the elevation of each such end panel as measured from the pivot point, i.e., the hinges to the ground, is greater than the distance of the axle to the ground, such that the "wheels"--actually felloes without treads, will rise off the ground. This positioning makes it easier to move the axles outwardly away from the wagon body 13, to the seating position as depicted in FIG. 10 as is seen in this figure, the two "wheels" become spaced up from the ground 69. FIG. 13 is a bottom plan view of the wagon portion 11 of this invention. This view depicts the moveability of the two axles to move the axles from the inner or wagon position as seen in FIG. 8 to the eating or outer position seen in FIG. 10. While the axles have generally been denoted as 23, for the sake of full clarity, each of the 4 axles has been designated by its location. Thus, in FIG. 13, the four axles have been designated as 23LF for left front, 23RF for right front, 23LR for left rear and 23RR for the right rear axle. Unlike FIGS. 8 and 10, the bottom plan view shows all 6 of the axles holders 24, each of which has a pair of side by side bores 28 therethrough designated 28A and 28B, with the "A" designated holes being the exterior positioned bores and the "B" designated bores being the interior positioned bores. These 3 sets of 2 bores are aligned in such a manner that the axles when in the inner or stowed position can pass through 3 of the designated pairs of aligned bores 28. Each axle has a pin strategically inserted normal to the length of the axle, along the length of the axle at a location 72 which is somewhat critical in that the placement is chosen for pin 36 such that the axles can be moved from a stowed position 72, passed through 3 axle holders as per the right part of the FIG. 13 drawing and FIG. 8; to a deployed position, 73, per the left part of the view being retained by 2 such axle holders. Thus the lateral movement is from the respective arrowed line positions, which match the positioning of the front axles, 72, to the extended location as shown in FIG. 10 and position 73. A typical pin may be a heavy duty, #14 size, headed wood screw not fully inserted into the axle, such that the axle cannot pass through the center axle holder when the axle is pulled out, and can pass through the opposite side axle holder, when the axle is stowed. See also FIGS. 8 and 10. Alternatively a cotter pin may be used for pin 36 as well as for cross pin 30 which holds the hub retainer in place. As seen in FIGS. 1, 2, and others the side walls 15, 17 are shown disposed in place in the table surface 33. When these are removed, the side walls serve as the seating for users of the apparatus 10 who desire to eat. One of the two side walls 17 is shown in FIG. 12. Side walls 15, 17 are each formed from a pair of 2×6 planks, designated 37 to which a plurality of cleats 35 have been attached at 90 degrees on the rear side thereof. Each cleat is of a greater elevation than the pair of abutted planks such that the lower portion of the cleat can be inserted into cleat slots 57, which penetrate table surface 33 and are seen in the bottom plan view FIG. 13. Notice the presence of table sides 39, seen from their underside in FIG. 12, as well as in FIG. 7. In FIG. 1, the standard canopy portion 12 is seen disposed on the wagon portion 11. The canopy portion is best seen in FIGS. 1, 2, 5 and 7. Canopy portion 12 comprises a flexible fabric generally rectangular section 14 having rolled tubular seams 18 on the forward and rear edges. These rolled seams 18 serve as support receivers, for flexible bendable rods 16--per FIG. 7, which are fed therethrough, and extend beneath each of the support receivers 18, for insertion into support mounts, 65, which are slots at each of the four corners of the table surface 33. These slots are similar to the cleat slots 57 also seen in FIG. 13. Attached to each rolled seam is an end portion preferably configured as a horseshoe and having a semicircular cutout therein as per FIG. 1. A Y-shaped tie string 82 (optional) may be retained in the air or optionally tied to an eyelet 84 at the respective end of table surface 33. See FIGS. 3 and 4. As seen in FIGS. 14 and 15, each canopy portion 12 may also include an optional flap 22 which can be raised to serve as a sun or rain shield for persons dining at the table surface 33. In FIG. 14, such flap 22 is shown in its downward position. The flap 22 is secured to a tubular rod receiver 75 which has a pair of opposed flaps 75F, attached thereto, one of which flaps is sewn to the fabric 14 and other of which flaps 75F is sewn to the flap 22. A rod 74 is disposed within the rod receiver to aid in the pivoting open and closed of the flap and to lend shape credence. Each flap 22 also includes a nipple shaped pole holder 26 disposed at each lower corner. This can be a small plastic member 1-inch long such as schedule 40 PVC. The pole holder 26 may be glued, sewn or otherwise retained, in the corners of the canopy fabric 14. A preferably telescopic pole 56 having an end 58 which may be a rubber boot or a spike as may be desired, at its distal end has its proximal end inserted into the pole holder 26, per FIG. 15. Two sets of two pole clips 59 can be mounted to the underside of the table surface 33 to retain the four poles 56 when not employed. See FIG. 13. While not shown the optional tie 82 could also be employed in this variant of the canopy. It is seen that I have created a unique convertible wagon which can be changed from a decorative apparatus to a useable eating table by carrying out a series of steps. These steps include, the removal of the side walls, 15, 17, the orientation of the end walls from a stowed up to a usable down position. The lowering of the front and rear panels, automatically raises the apparatus off of the wheels such that the weight is born by the front and rear panels. The result is that the wheels will be raised a few inches off of the ground. (This is the same effect that arises upon using a jack to change a tire.) This enables the axles having the wheels thereon to be moved outwardly such that the previously removed side walls can be placed across the now extended axles to provide seating at the table surface 33. The cleats serve as lateral movement inhibitors for the thus located side walls. The apparatus of this invention can be made any size to accommodate strictly children or full-size adults. The materials mentioned, mostly 2×6 inch boards will easily accommodate the weight of several adult males along the length thereof. In case of rain or sun, the optional flaps can be raised to provide shade or relief from the rain as may be desired at any point in time. The raising constitutes the removal of the poles from their clip mounting on the under side of the table surface, and the insertion of the poles, which are made of a cross section just slightly less than that of the pole holders, into the pole holders of the flaps. In case of a wind the drawn string a tree string 82 can be secured to its eyelet 84. Since certain changes may be made in the above described apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description and in the accompanying drawings, if present, shall be interpreted as illustrative only and not in a limiting sense.

A ranch wagon, which can easily be converted to a picnic table and opposed bench seating. The unit conversion involves removing the side walls, laying them aside, and relocating the front and rear panels from an upward stowed to a lower eating position, and moving the axles from a first inner position to a second outer position. The two side walls are then disposed across the spaced outwardly extended axles. The optional canopy which can include a flap at each end, can be left in place to protect items on the table surface from sun, or removed as is desired.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to anti-aggregatory agents for platelets, specifically oligopeptides which inhibit fibrinogen-platelet binding. 2. Background of the Related Art The control and selective prevention of uncontrolled clotting is an important medicinal and clinical goal. The production of a blood clot in response to an injury can often become life-threatening when occurring at inopportune times and locations in the circulatory system. Human blood platelets function to prevent bleeding by adhering to the surface of damaged blood vessels and then aggregating with one another. In pathological conditions, platelet aggregation and thrombus formation can be inappropriate, leading to occlusion of blood vessels, as occurs in heart attacks and strokes. These thrombotic diseases are some of the most common cause of death each year throughout the world. In addition, this same process is responsible for venous thrombosis, pulmonary embolism, and failure of vascular graft surgery, which are all serious medical problems affecting millions of patients; See, Green et al., "Anticoagulant Biotherapeutics for Heart Disease and Stroke" Anticoagulant, Spectrum Biotechnology Applications, Decision Resources, Inc. (Aug. 8, 1991). A blood clot can obstruct a vessel, stop the supply of blood to the heart, limb or to an essential organ. Clots which become detached, called embolisms can flow through the circulatory system causing blockages at sites which are remote from the point of original injury and clot. If processes for blood clotting could be controlled, sufficient clotting can be obtained to allow healing of an injury without creating uncontrolled thrombi. Control of the clotting mechanism may be useful in preventing heart attacks due to reocclusion at the site of a clot, strokes, injuries due to embolisms and other clotting related injuries. There are three related mechanisms involved in blood coagulation. The coagulation cascade leads to the generation of thrombin resulting in the conversion of fibrinogen to fibrin, a mesh-like structure that makes up a clot. The thrombolytic mechanism leads to clot dissolution by converting plasminogen into the clot-digesting enzyme plasmin. Platelet adhesion and aggregation, the third mechanism, contribute to clot formation by forming a cellular plug and by enhancing thrombin formation. Platelets may be activated by several different agonists such as adenosine diphosphate (ADP), epinephrine, collagen and thrombin that are released in the circulatory system in response to injury. These agonists have the ability to alter the surface glycoprotein GPIIb/IIIa receptors of platelets so that they can bind fibrinogen and other adhesive glycoproteins. Fibrinogen, a dimeric molecule binds to two platelets simultaneously and acts as a bridging molecule, producing an extensive lattice formation. The GPIIb/IIIa receptors are present at a very high density on the surface of platelets, each platelet containing approximately 40,000-50,000 such receptors. The importance of the GPIIb/IIIa receptors in platelet aggregation is demonstrated by the failure of platelets to aggregate when taken from patients suffering from Glanzmann thrombasthenia, who lack the GPIIb/IIIa receptor, and the ability of monoclonal antibodies to the GPIIb/IIIa receptor to abolish platelet aggregation. Accordingly, non-immunogenic peptide-based inhibitors with high specificities would have tremendous therapeutic potential. These type of inhibitors could offer the prospect of rapid inhibition of platelet aggregation. In addition, they could be given repeatedly since they are small enough to be non-immunogenic. This is a substantial advantage over monoclonal antibodies which may be immunogenic. The GPIIb/IIIa receptor is part of a superfamily of adhesion receptors, many of which share a common recognition site for peptides containing the short hydrophilic amino acid sequence arginine-glycine-aspartic acid (RGD). In fact, all proteins that bind to the platelets GPIIb/IIIa receptor, for example fibrinogen, yon Willebrand factor, fibronectin and vitronectin have RGD sequence in their cell binding domains. Synthetic peptides containing this sequence act as competitive, reversible inhibitors in assays of cellular adhesion. They compete directly for fibrinogen binding sites on platelets in a noncytotoxic manner. Various linear RGD peptides have been synthesized for the purpose of preventing platelet aggregation, for example see, Samanen et. al., J. Med. Chem., 34, 3114-3125 (1991). Many of those synthetic linear RGD peptides are described in U.S. Pat. Nos. 5,047,380; 4,683,291; 4,578,079; 4,614,517; 4,792,525; 4,992,463; and in European Patent Publication EP 298 820 A1. U.S. Pat. No. 4,683,291 in addition to disclosing linear RGD peptides also discloses linear RGD polypeptides and branched RGD containing peptides. Various cyclic peptides containing the RGD sequence have also been synthesized, as described in U.S. Pat. No. 5,023,233 and in foreign patent publications EP 425 212 A2; EP 410 537 A1; JP 2-174797 and GP 3,41915 A2, and PCT publication WO 90/02751. Therefore, a purpose of the present invention is to control the blood coagulation process by providing peptide based agents which competitively inhibit fibrinogen-platelet binding. Another purpose of this invention is to provide oligopeptides that cannot easily be degraded by hydrolytic enzymes, i.e. proteases and peptidases, in the circulatory system, and allow these oligopeptides to inhibit fibrinogenplatelet binding. A further purpose of the present invention is the production of peptide based agents which are non-immunogenic and highly efficient in preventing fibrinogen-platelet binding so that these agents can serve as therapeutic drugs. SUMMARY OF THE INVENTION These purposes and goals are satisfied by the present invention which provides synthetic anti-aggregatory agents for preventing inhibition of fibrinogen-platelet binding. These anti-aggregatory agents have the general formulas (1)-(5). H--[--(AA.sub.i).sub.i --R--G--D--(AA.sub.j).sub.j --].sub.n --Cx (1) [R.sub.1 --C(O)--R--G--D--(AA.sub.j).sub.j --].sub.n --Cx (2) Cy--[--(AA.sub.i).sub.i --R--G--D--(AA.sub.j).sub.j --].sub.n --Z (3) H--[--(AA.sub.i).sub.i --R--G--D--(AA.sub.j).sub.j --].sub.n --Cz--[--(AA.sub.k).sub.k --R--G--D--(AA.sub.l).sub.l --].sub.m --Z (4) [R.sub.1 --C(O)--R--G--D--(AA.sub.i).sub.i --].sub.n --CZ[--(AA.sub.j).sub.j --R--G--D--(AA.sub.k).sub.k --].sub.m --Z (5) in which: R=Arg; G=Gly; D=Asp; AA i , AA j , AA k and AA l =alpha-, beta- and omega-amino acid residues; (AA i ) i =peptide chains having the same or different amino acid residues; (AA j ) j =peptide chains having the same or different amino acid residues; (AA k ) k =peptide chains having the same or different amino acid residues; and (AA l ) l =peptide chains having the same or different amino acid residues; i and j=integers 0-20; m=an integer 1-10; n=an integer 2-10; Cx=a conjugator bearing at least two amine residues in a molecule having 1-30 carbon atoms, i.e, diamines, triamines, tetramines, and polyamines, which can have other functional groups in the molecule; Cy=a conjugator bearing at least two carboxyl residues in a molecule having 1-30 carbon atoms, i.e., aliphatic, aromatic, heteroaromatic cycloalkyl dicarboxylic acid, tricarboxylic acid, and polycarboxylic acid residues, which can have other functional groups in the molecule; Cz=a conjugator bearing at least one amine residue and one carboxyl residue in an aromatic or a cycloalkyl skeleton, having 1-30 carbon atoms, i.e., aromatic, heteroaromatic and cycloalkyl amino carboxylic acid, diamino carboxylic acid, diamino dicarboxylic acid, and ployamino polycarboxylic acid residues; R 1 =an alkyl, aromatic, heteroaromatic, or cycloalkyl group having 1-30 carbons, which can have other functional groups in the molecule; Z=carboxyl, amide, N-substituted amide, hydrazide, N-substituted hydrazide, or ester group. For a better understanding of the present invention, reference is made to the following description and the accompanying tables, the scope of which is pointed out in the claims. DETAILED DESCRIPTION OF THE INVENTION In accordance with the preferred embodiments of the present invention, the inventors have synthesized new peptides bearing more than one RGD sequences in a branched manner to obtain better binding to the GPIIb/IIIa receptor than that shown by single RGD peptides of the prior art. Linear peptides containing non-natural protein amino acid residues or non-amino acid residues have also been synthesized to determine their effect on the inhibition of platelet aggregation. Increasing the number of RGD sequence in a molecule which interacts with the receptor should enhance its overall inhibitory activity, i.e., higher local concentrations of the RGD sequence should provide better inhibitory activity because the probability that they would interact with the receptor should be increased. This is the concept upon which the RGD peptide based anti-aggregatory agents of the present invention were developed. In addition to naturally occurring protein amino acid residues, synthetic, non-naturally occurring protein amino acid residues as well as non-amino acid residues have been introduced to prevent degradation by proteases and peptidases in the circulatory system. More than one, and up to a maximum of three (3) RGD units combined with a conjugator, forms the basic structure of the RDG peptide based anti-aggregatory agents of the present invention. The conjugator can be a diamino acid, a dicarboxylic acid, tricarboxylic acid, diamine and so on. Modification of the conjugator is sometimes critical to obtain high inhibitory activity because the structure of the conjugator influences the conformation of the RGD sequence. Also, the length of the conjugator is crucial. It should not be too long to avoid the promotion of platelet aggregation, which may be caused by accommodation of two platelets by two RGD units. Furthermore, when branching is increased to a much higher level, the poly-RGD peptide loses its inhibitory activity. For example, a highly branched RGD peptide, [(GRGDF) 2 K] 2 K--NH 2 that has four (4) RGD sequences does not show any inhibitory activity even at a concentration of 1×10 -3 M. The preferred anti-aggregatory agents for inhibiting fibrinogen-platelet binding, according to the present invention have the general formula (1)-(5): H--[--(AA.sub.i).sub.i --R--G--D--(AA.sub.j).sub.j --].sub.n --Cx (1) preferably, (RGDFPG).sub.2 Dab--G--OH (RGDFPG).sub.2 Dab--NH.sub.2 (RGDF).sub.2 Lys--NH.sub.2 (GRGDF).sub.2 Lys--NH.sub.2 (GRGDF).sub.2 Orn--NH.sub.2 (RGDF).sub.2 Dac--NH.sub.2 [R.sub.1 --C(O)--R--G--D--(AA.sub.j).sub.j --].sub.n --Cx (2) preferably, (BzRGDF).sub.2 Lys--NH.sub.2 (HexRGDF).sub.2 Lys--NH.sub.2 (BzRGDFP).sub.2 Lys--NH.sub.2 (HexRGDFP).sub.2 Lys--NH.sub.2 Cy--[--(AA.sub.i).sub.i --R--G--D--(AA.sub.j).sub.j --].sub.n --Z (3) preferably, (p)Pht(RGDF--OH).sub.2 Suc(RGDF--OH).sub.2 Pda(RGDF--OH).sub.2 Bda(RGDF--OH).sub.2 H--[--(AA.sub.i).sub.i --R--G--D--(AA.sub.j).sub.j --].sub.n --Cz--[--(AA.sub.k).sub.k --R--G--D--(AA.sub.l).sub.l --].sub.m --Z (4) preferably, (GRGDFG).sub.2 Dab--GRGDF--NH.sub.2 (RGDF).sub.2 Dac--RGDF--OH (GRGDSG).sub.2 Dab--GRGDS--OH (RGDV).sub.2 Lys--GRGDV--NH.sub.2 (GRGDF).sub.2 Lys--GRGDF--NH.sub.2 (GRGDF).sub.2 Orn--GRGDF--NH.sub.2 GRGDFG--(o) Abz--GRGDF--OH GRGDFG--(m) Abz--GRGDF--OH GRGDFG--(p) Abz--GRGDF--OH GRGDFG--(o) Abz--GRGDF--NH.sub.2 GRGDFG--(m) Abz--GRGDF--NH.sub.2 GRGDFG--(p) Abz--GRGDF--NH.sub.2 GRGDSG--(o) Abz--GRGDF--NH.sub.2 GRGDSG--(m) Abz--GRGDF--NH.sub.2 GRGDSG--(p) Abz--GRGDF--NH.sub.2 GRGDVG--(o) Abz--GRGDF--NH.sub.2 GRGDVG--(m) Abz--GRGDF--NH.sub.2 GRGDVG--(p) Abz--GRGDF--NH.sub.2 R.sub.1 --C(O)--R--G--D--(AA.sub.i).sub.i --].sub.n --CZ[--(AA.sub.j).sub.j --R--G--D--(AA.sub.k).sub.k --].sub.m --Z (5) preferably, (BzRGDF).sub.2 Dac--RGDF--OH, in which: R=Arg; G=Gly; D=Asp; (AA i ) i =peptide chains having the same or different amino acid residues; (AA j ) j = peptide chains having the same or different amino acid residues; (AA k ) k =peptide chains having the same or different amino acid residues; and (AA l ) l =peptide chains having the same or different amino acid residues; i and j = integers 0-20; m=an integer 1-10; n=an integer 2-10; Cx=a conjugator bearing at least two amine residues in a molecule having 1-30 carbon atoms, i.e, diamines, triamines, tetramines, and polyamines, which can have other functional groups in the molecule; Cy=a conjugator bearing at least two carboxyl residues in a molecule having 1-30 carbon atoms, i.e., aliphatic, aromatic, heteroaromatic, cycloalkyl dicarboxylic acid, tricarboxylic acid, and polycarboxylic acid residues, which can have other functional groups in the molecule; Cz=a conjugator bearing at least one amine residue and one carboxyl residue in an aromatic or a cycloalkyl skeleton, having 1-30 carbon atoms, i.e., aromatic, heteroaromatic and cycloalkyl amino carboxylic acid, diamino carboxylic acid, diamino dicarboxylic acid, and ployamino polycarboxylic acid residues; R 1 =an alkyl, aromatic, heteroaromatic, or cycloalkyl group having 1-30 carbons, which can have other functional groups in the molecule; Z=carboxyl, amide, N-substituted amide, hydrazide, N-substituted hydrazide or ester group. The non-naturally occurring protein amino acid residues and non-amino acid residues include: Dab=3,5-Diaminobenzoic acid residue; Abz=Aminobenzoic acid residue; Dac=3,5-Diaminocyclohexanecarboxylic acid residue; Pht=Phthalic acid residue; Suc=Succinic acid residue; Pda =Propanedicarboxylic acid residue; Bda=Butanedicarboxylic acid residue; (o)=ortho; (m)=meta; and (p)=para. The common naturally-occurring protein amino acids are: ______________________________________NATURAL AMINO ACIDS 1-LetterName 3-Letter Abbreviation Abbreviation______________________________________(+)-Alanine Ala A(+)-Arginine Arg R(-)-Asparagine Asn N(+)-Aspartic acid Asp D(-)-Cysteine Cys C(+)-Glutamic acid Glu E(+)-Glutamine Gln Q Glycine Gly G(-)-Histidine His H(+)-Isoleucine Ile I(-)-Leucine Leu L(+)-Lysine Lys K(-)-Methionine Met M(-)-Phenylalanine Phe F(-)-Proline Pro P(-)-Serine Ser S(-)-Threonine Thr T(-)-Tryptophane Trp W(-)-Tyrosine Tyr Y(-)-Valine Val V______________________________________ Theraputic Dosage Formulations In the management of thromboembolic disorders the compounds of this invention may be utilized in compositions such as tablets, capsules or elixers for oral administration, suppositories for rectal administration, sterile solutions or suspensions for injectable administration, and the like. Animals in need of treatment using compounds of this invention can be administered dosages that will provide optimal efficacy. The dose and method of administration will vary from animal to animal and be dependent upon such factors as weight, diet, concurrent medication and other factors which those skilled in the medical arts will recognize. Dosage formulations of the anti-aggregatory agents of the present invention are prepared for storage or administration by mixing the anti-aggregatory agents having the desired degree of purity with physiologically acceptable carriers, excipients, or stabilizers. Such materials are non-toxic to the recipients at the dosages and concentrations employed, and include buffers such as phosphate, citrate, acetate and other organic acid salts; antioxidents such as ascorbic acid; low molecular weight (less than about ten residues) peptides such as polyarginine, proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidinone; amino acids such as glycine, glutamic acid, aspattic acid, or arginine; monosaccharides, disaccharides, and other carbohydrates including cellulose or its derivatives, glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sobitol; counterions such as sodium and/or nonionic surfactants such as Tween, Pluronics or polyethyleneglycol. Dosage formulations of the anti-aggregatory agents of the present invention to be used for therapeutic administration must be sterile. Sterility is readily accomplished by filtration through sterile filtration membranes such as 0.2 micron membranes. Anti-aggregatory formulations ordinarily will be stored in lyophilized form or as an aqueous solution. The pH of the anti-aggregatory preparations typically will be between 3 and 11, more preferably from 5 to 9 and most preferably 7 and 8. It will be understood that use of certain of the foregoing excipients, carriers, or stabilizers will result in the formation of salts of the anti-aggregatory peptides. While the preferred route of administration is by hypodermic injection needle, other methods of administration are also anticipated such as suppositories, aerosols, oral dosage formulations and topical formulations such as ointments, drops and dermal patches. Therapeutic anti-aggregatory formulations generally are placed into a container having a sterile access port, for example, an intravenous solution bag or vial having a stopper pierceable by hypodermic injection needle. Therapeutically effective dosages may be determined by either in vitro or in vivo methods. One method of evaluating therapeutically effective dosages is the in vitro platelet aggregation inhibitory assay described below. Based upon such in vitro assay techniques, a therapeutically effective dosage range may be determined. For each particular anti-aggregatory peptide formulation of the present invention, individual determinations may be made to ascertain the optimal dosage required. The range of therapeutically effective dosages will naturally be influenced by the route of administration. For injection by hypodermic needle it may be assumed the dosage is delivered into the body's fluid. For other routes of administration, the absorption efficiency must be individually determined for each anti-aggregatory peptide formulation by methods well known in pharmacology. The range of therapeutic dosages may range from about 0.01 nM to about 1.0 mM, more preferably from 0.1 nM to about 100 μM, and most preferably from about 1.0 nM to 50 μM. A typical formulation of compounds of Formulae (1)-(5) as pharmaceutical compositions contain from about 0.5 to 500 mg of a compound or mixture of compounds as either the free acid or base form or as a pharmaceutically acceptable salt. These compounds or mixtures are then compounded with a physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilzer, or flavor, etc., as called for by accepted pharmaceutical practice. The amount of active ingredient in these compositions is such that a suitable dosage in the range indicated is obtained. Typical adjuvants which may incorporated into tablets, capsules and the like are a binder such as acacia, corn starch or gelatin; an excipient such as microcrystalline cellulose; a disintegrating agent like corn starch or alginic acid; a lubricant such as magnesium stearate; a sweetening agent such as sucrose or lactose; a flavoring agent such as peppermint, wintergreen or cherry. When the dosage form is a capsule, in addition to the above materials it may also contain a liquid carrier such as a fatty oil. Other materials of various types may be used as coatings or as modifiers of the physical form of the dosage unit. A syrup or elixer may contain the active compound, a sweetener such as sucrose, preservatives like propylparaben, a coloring agent and a flavoring agent such as cherry. Sterile compositions for injection can be formulated according to conventional pharmaceutical practice. For example, dissolution or suspension of the active compound in a vehicle such as water or naturally occuring vegatable oil like sesame, peanut, or cottonseed oil or a synthetic fatty vehicle like ethyl oleate or the like may be desired. Buffers, preservatives, antioxidants and the like can be incorporated according to accepted pharmaceutical practice. Experimental Procedures 1. In vitro Inhibition of Aggregation of Human Platelet-Rich Plasma Whole blood (10 ml) was collected from human volunteers and anticoagulated by addition of 100 ml of 40% sodium citrate. Platelet-rich plasma (PRP) was prepared by low speed centrifugation (700 G for 3.5 min at 22° C.). The PRP was removed and the remaining blood was centrifuged at 2000 G for 10 min at 22 ° C. to obtain platelet poor plasma (PPP). The PRP was diluted with PPP to give a final platelet count of 300 000μL with a Coulter Acounter Model ZM (Coulter, Hialeah, Fla.). This diluted PRP (400μL) was placed in a siliconized glass cuvette equipped with a magnetic stirrer and stirred at 1200 rpm at 37° C. Various concentrations of the peptides (36μL) in TRIS buffer (0.01 M TRIS, 0.15 M NaCl, and 0.05% sodium azide, pH 7.4) was added and incubated for 3 rain before platelet aggregation was induced by addition of 54μL of 100μM ADP in HEPES buffer (0.01 M HEPES and 0.15 M NaCl, pH 7.5). The platelet aggregation was determined by a change in light transmission through the PRP on a Lumi Aggregometer 400rS (ChronoLog, Hayertown, PA). The ability of the peptides to inhibit platelet aggregation was evaluated and the IC 50 was determined as the concentration of peptide required to produce 50% inhibition of the response to ADP in the presence of the TRIS buffer. 2. Comparison of Different Assay Methods The assay system developed by Coller, which is used throughout the experiment, is different from conventional assay systems in certain aspects. First, the platelets used by Plow et al., Blood, 70, 110 (1987); and Garsky et al., Proc. Natl. Acad. Sci. U.S.A., 86, 4022 (1989) are gel-filtered to remove plasma proteins. Since the gel-filtration treatment may decrease the reactivity of the platelets, our assay avoids this step. The platelet count is adjusted by simply mixing PRP and PPP, which minimizes alterations of the platelets. Second, fibrinogen concentration in the Coller system is different from that of others. As shown in the experimental description of the assay, PRP was obtained from fresh blood and used immediately without further manipulation except for count adjustment. According to measurements obtained using this assay, such plasma contains ca. 3 mg of fibrinogen per 1 mL of plasma. On the other hand, fibrinogen concentration used in the Garsky and Plow assay system is 0.1 mg/mL. The concentration of fibrinogen affects the amount of RGD peptide required to inhibit platelet aggregation, with higher fibrinogen concentrations resulting in higher IC 50 values. If there is a linear relationship between these two parameters, the IC 50 values obtained from the Coller assay should be ca. 30 times larger than those obtained from the Plow et al. assay or the Garsky et al. assay. The adjusted IC 50 values are presented in column 4 of Table showing the inhibitory activities of RGD peptides. 3. Materials for the Synthesis of Peptides N-9-Fluorenylmethoxycarbonylamino acids (Fmoc amino acids) were purchased from E. I. du Pont de Nemours & Co.(Boston, Mass.), Sigma Chemical Co.(St. Louis, Miss.), Peptides International Inc.(Louisville, Ken.), and AminoTech Inc. RAPID AMIDE™ resin and WANG™ resin were purchased from E. I. du Pont de Nemours & Co. All solvents were purchased from Aldrich Chemical Co. (Milwaukee, Wis.), J. T. Baker Inc. (Phillipsburg, N.J.) and, Fisher Scientific Co.(Pittsburgh, Pa.) 1-Hydroxybenzotriazole (HOBt), thioanisol, 1,2-ethanedithiol, and diisopropylcarbodiimide (DIC) were purchased from E. I. du Pont de Nemours & Co. Liquified phenol was purchased from Fisher Scientific Co. All other reagents were purchased from Aldrich Chemical Co.(Milwaukee, Wis.). 4. General Procedure for the Synthesis of Peptides Solid phase peptide synthesis was carried out on a Du Pont RAMPS® Multiple Peptide Synthesis System. High performance liquid chromatography (HPLC, preparative and analytical) was carried out by using a Waters μBondaPak C-18 column on a HPLC assembly consisting of a Waters 600E Multisolvent Delivery System, a Waters 484 tunable absorbance detector and a NEC Powermate workstation a with Microsoft Baseline 810 program (Waters, Milford, Mass.). A cycle of the peptide coupling procedure included one of the following operations: (A) The procedure for peptides having an amide terminus (the entire procedure was operated at ambient temperature). The RAPID AMIDE™ resin (0.1 mmol) was prepared for coupling by neutralization using 50% piperidine in dimethylformamide (DMF) (2 mL). The resin was washed with DMF (3×2 mL), methanol (3×2 mL) and again with DMF (4×2 mL). The Fmoc amino acid was then activated via the pentafluorophenyl (Pfp) ester (vide infra) or HOBt ester (vide infra) methods followed by addition of the activated Fmoc amino acid to the RAPID AMIDE™ resin. The resulting mixture was rocked for 2 h periods for coupling reaction. Coupling was followed by rinsing with DMF (3×2 mL), MeOH (3×2 mL), then with DMF (4×2 mL). The Fmoc group of the last coupled amino acid was removed using 50% piperidine in DMF (2 mL). The resin was washed alternately with DMF (3×2 mL) and methanol (3×2 mL) and again with DMF (4×2 mL) for the next coupling process. When the last amino acid had been coupled, the peptide was cleaved from the resin using TFA (2.85 mL), liquified phenol (185 μL), and 1,2-ethanedithiol (15 μL). The peptide thus obtained was washed with ether (4×20 mL), dissolved in water (1 mL) and lyophilized to give a white solid. All peptides were purified by preparative reversed-phase HPLC using a Waters μBondaPak C-18 (19 mm×15 cm) column. (B) The procedure for peptides having a carboxyl acid terminus (the entire procedure was operated at ambient temperature). The WANG™ resin (0.1 mmol) was prepared for coupling by the deprotection of Fmoc group of the amino acid which was already attached to the resin using 50% piperidine in DMF (2 mL) and washing with DMF (3×2 mL), methanol (3 ×2 mL) and again with DMF (4×2 mL). The Fmoc amino acid was then activated via the pentafluorophenyl (Pfp) ester (vide infra) or HOBt ester (vide infra) methods followed by addition of the activated Fmoc amino acid to the WANG™ resin. The resulting mixture was rocked for 2 h periods for coupling reaction. Coupling was followed by rinsing with DMF (3×2 mL), MeOH (3×2 mL), then with DMF (4×2 mL). The Fmoc group of the last coupled amino acid was removed using 50% piperidine in DMF (2 mL). The resin was washed alternately with DMF (3×2 mL) and methanol (3×2 mL) and again with DMF (4×2 mL) for the next coupling process. When the last amino acid had been coupled, the peptide was cleaved from the resin using TFA (2.85 mL), thioanisol (185 μL), and 1,2-ethanedithiol (15 μL). The peptide thus obtained was washed with ether (4×20 mL), dissolved in water (1 mL) and lyophilized to give a white solid. All peptides were purified by preparative reversed-phase HPLC using a Waters μBondaPak C-18 (19 mm×15 cm) column. 5. Activation of Fmoc-amino acids by Pfp ester method A suspension of the Fmoc-amino acid (0.25 mmol) in dichloromethane (1 mL) was stirred at 0 ° C. for 5 min. To this suspension was added pentafluorophenol (0.25 retool) in DMF (46 mL of a 5.4 M solution) and DIC (39 mL) at 0 ° C. The mixture was stirred for 5 rain at room temperature. A solution of HOBt in DMF (0.2 mL of a 0.5 M solution) was added directly to the resin, followed by the activated amino acid solution. The vial was rinsed with DMF (2 mL) and the washings were added to the resin. 6. Activation of Fmoc-amino acids by HOBt ester method A suspension of the Fmoc-amino acid (0.25 mmol) in dichloromethane (1 mL) was stirred at 0° C. for 5 min. To this suspension was added HOBt (0.5 mL of a 0.5 M solution) and DIC (39 mL) at 0° C. The mixture was stirred for 5 rain at room temperature. The activated amino acid solution was added directly to the resin. The vial was rinsed with DMF (2 mL) and the washings were added to the resin. 7. Amino Acid Analysis of Peptides The analyses were carried out through the Waters PICO.TAG™ procedure. The peptides were hydrolyzed with PICO.TAG™ 1% liquified phenol in 6 N HC1 at 100 ° C. for 24 hours. The resulting mixture of amino acids were derivatized with 20 mL of phenyl isothiocyanate. The derivatized amino acids were analyzed on a Waters PICO.TAG™ column by using a gradient of 6% acetonitrile (triethylamine-sodium acetateacetic acid buffer pH 6.4) to 30% acetonitrile over a period of 10 min at a flow rate of 1.0 mL/min. The following peptides were synthesized, and their amino acid contents were analyzed as described in procedures 3-7, above. In addition, their ability to inhibit aggregation of human platelet rich plasma was assessed as described in procedures 1 and 2, above. Their respective IC 50 values, as well as their estimated IC 50 adjusted to the values according the method of Plow et al., (vide supra) are listed in Table 1. TABLE 1__________________________________________________________________________ FormulaExamplePeptide (1)-(5) IC.sub.50 (M) IC.sub.50 (M)*__________________________________________________________________________1 (RGDFPG).sub.2 Dab--G--OH 1 2.0 × 10.sup.-5 6.7 × 10.sup.-72 (RGDFPG).sub.2 Dab--NH.sub.2 " 1.3 × 10.sup.-5 4.2 × 10.sup.-73 (RGDF).sub.2 Lys--NH.sub.2 " 3.5 × 10.sup.-5 1.2 × 10.sup.-64 (GRGDF).sub.2 Lys--NH.sub.2 " 1.1 × 10.sup.-4 3.5 × 10.sup.-65 (GRGDF).sub.2 Orn--NH.sub.2 " 1.3 × 10.sup.-4 4.4 × 10.sup.-66 (RGDF).sub.2 Dac--NH.sub.2 " 5.0 × 10.sup.-5 1.7 × 10.sup.-67 (BzRGDF).sub.2 Lys--NH.sub.2 2 8.8 × 10.sup.-6 2.9 × 10.sup.-78 (HexRGDF).sub.2 Lys--NH.sub.2 " 2.3 × 10.sup.-6 7.6 × 10.sup.-89 (BzRGDFP).sub.2 Lys--NH.sub.2 " 3.7 × 10.sup.-6 1.2 × 10.sup.-710 (HexRGDFP).sub.2 Lys--NH.sub.2 " 2.7 × 10.sup.-6 9.0 × 10.sup.-811 (p)Pht(RGDF--OH).sub.2 3 1.3 × 10.sup.-5 4.2 × 10.sup.-712 Suc(RGDF--OH).sub.2 " 1.5 × 10.sup.-5 5.0 × 10.sup.-713 Pda(RGDF--OH).sub.2 " 1.5 × 10.sup.-5 5.0 × 10.sup.-714 Bda(RGDF--OH).sub.2 " 1.4 × 10.sup.-5 4.7 × 10.sup.-715 (GRGDFG).sub.2 Dab--GRGDF--NH.sub.2 4 3.3 × 10.sup.-5 1.1 × 10.sup.-616 (GRGDFG).sub.2 Dac--RGDF--OH " 2.2 × 10.sup.-5 7.2 × 10.sup.-717 (GRGDFG).sub.2 Lys--GRGDF--NH.sub.2 " 5.1 × 10.sup.-5 1.7 × 10.sup.-618 (GRGDFG).sub.2 Orn--GRGDF--NH.sub.2 " 6.2 × 10.sup.-5 2.1 × 10.sup.-619 GRGDFG-(o)Abz--GRGDF--OH " 6.3 × 10.sup.-5 2.1 × 10.sup.-620 GRGDFG-(m)Abz--GRGDF--OH " 1.9 × 10.sup.-5 6.2 × 10.sup.-721 GRGDFG-(p)Abz--GRGDF--OH " 3.5 × 10.sup.-5 1.2 × 10.sup.-622 GRGDFG-(o)Abz--GRGDF--NH.sub.2 " 9.3 × 10.sup.-5 3.1 × 10.sup.-623 GRGDFG-(m)Abz--GRGDF--NH.sub.2 " 5.2 × 10.sup.-5 1.7 × 10.sup.-624 GRGDFG-(p)Abz--GRGDF--NH.sub.2 " 5.9 × 10.sup.-5 2.1 × 10.sup.-625 GRGDSG-(o)Abz--GRGDF--NH.sub.2 " 6.3 × 10.sup.-5 2.1 × 10.sup.-626 GRGDSG-(m)Abz--GRGDF--NH.sub.2 " 9.1 × 10.sup.-5 3.0 × 10.sup.-627 GRGDSG-(p)Abz--GRGDF--NH.sub.2 " 5.2 × 10.sup.-5 1.7 × 10.sup.-628 GRGDVG-(o)Abz--GRGDF--NH.sub.2 " 9.2 × 10.sup.-5 3.1 × 10.sup.-629 GRGDVG-(m)Abz--GRGDF--NH.sub.2 " 4.6 × 10.sup.-5 1.5 × 10.sup.-630 GRGDVG-(p)Abz--GRGDF--NH.sub.2 " 2.6 × 10.sup.- 5 8.5 × 10.sup.-731 (BzRGDF).sub.2 Dac--RGDF--OH " 7.4 × 10.sup.-6 2.5 × 10.sup.-7__________________________________________________________________________ Dab = 3,5Diaminobenzoic acid residue, Abz = Aminobenzoic acid residue, Da = 3,5Diaminocyclohexanecarboxylic acid residue; Pht = Phthalic acid residue, Suc = Succinyl residue, Pda = Propanedicarboxylic acid residue, Bda = Butanedicarboxylic acid residue, Bz = Benzoyl, Hex = Hexanoyl. *Estimated IC.sub.50 adjusted to the values by the method of Plow et al. (vide supra). EXAMPLE 1 (RGDFPG) 2 Dab--G--OH The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (138 rag, 87 % yield). A portion (78 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 27% CH 3 CN-0.1% TFA over a period of 30 rain and an isocratic of 27% CH 3 CN-0.1% TFA over a period of 10 rain at a flow rate of 8 mL/min. The fractions containing the desired peptides were collected, lyophilized, dissolved in water, and salt-exchanged on a Sephadex column using a 20% acetic acid as the eluent. The elutes were lyophilized to give the pure peptide as the acetic acid salt (33.3 rag, white feather-like powder). Amino acid analysis: Asp 2.00, Gly 5.20, Arg 2.20, Pro 2.04, Phe 1,84. FAB-MS:1468.1 (M+i) + . EXAMPLE 2 (RGDFPG) 2 Dab--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (141 rag, 91% yield). A portion (51 mg) of the product was purified on a μBondaPak C-18 column using a gradient of 0% CH 3 CN-0.1% TFA to 27% CH 3 CN-0.1% TFA over a period of 30 min and an isocratic of 27% CH 3 CN-0.1% TFA in 10 min at a flow rate of 8 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-G-OH to give the pure peptide as the acetic acid salt (23.9 mg, white feather-like powder). Amino acid analysis: Asp 1.78, Gly 4.00, Arg 2.20, Pro 2.08, Phe 2.00. FAB-MS:1410.6 (M+1) + . EXAMPLE 3 (RGDF) 2 Lys--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (162 rag, 100% yield). A portion (80 rag) of the .product was purified on a BondaPak C-18 column by using a gradient of 6% CH 3 CN-0.1% TFA to 24% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 7 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-G-OH to give the pure peptide as the acetic acid salt (43 mg, white feather-like powder). Amino acid analysis: Asp 1.98, Gly 2.00, Arg 2.20, Phe 1.98, Lys 0.90. FAB-MS:1097.3 (M+i) + . EXAMPLE 4 (GRGDF) 2 Lys--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (182 mg, 100 % yield). A portion (80 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 40% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 3 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-G-OH to give the pure peptide as the acetic acid salt (43 mg, white feather-like powder). Amino acid analysis: Asp 1.92, Gly 4.38, Arg 2.24, Phe 2.00, Lys 0.62. FAB-MS:1210.1 (M+1) + . EXAMPLE 5 (GRGDF) 2 Orn--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (172 mg, 100 % yield). A portion (80 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 40% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 3 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-G-OH to give the pure peptide as the acetic acid salt (52 mg, white feather-like powder). Amino acid analysis: Asp 1.88, Gly 4.38, Arg 2.26, Phe 2.00, Orn 0.78. FAB-MS:1197.2 (M+1) + . EXAMPLE 6 (RGDF) 2 Dac--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (80 mg, 70 % yield). A portion (20 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 10% CH 3 CN-0.1% TFA to 60% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 8 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-G-OH to give the pure peptide as the acetic acid salt (7 mg, white feather-like powder). Amino acid analysis: Asp 0.94, Gly 1.00, Arg 1.06, Phe 1.05. FAB-MS:1108.1 (M+1) + . EXAMPLE 7 (BzRGDF) 2 Lys--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (80 rag, 62% yield). A portion of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 60% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 7 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-G-OH to give the pure peptide as the acetic acid salt (17 mg, white feather-like powder). Amino acid analysis: Asp 1.98, Gly 2.08, Arg 2.00, Phe 2.04, Lys 0.92. FAB-MS:1293.1 (M+i) + . EXAMPLE 8 (HexRGDF) 2 Lys--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (83 rag, 64% yield). A portion of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 60% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 7 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG)2Dab-G-OH to give the pure peptide as the acetic acid salt (16 mg, white feather-like powder). Amino acid analysis: Asp 1.96, Gly 2.07, Arg 2.10, Phe 2.00, Lys 0.92. FAB-MS: 1304.6 (M+1) + . EXAMPLE 9 (BzRGDFP) 2 Lys--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (111 rag, 74% yield). A portion of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 60% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 7 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-G-OH to give the pure peptide as the acetic acid salt (24 mg, white feather-like powder). Amino acid analysis: Asp 1.88, Gly 1.93, Arg 2.00, Pro 2.14, Phe 1.99, Lys 0.80. FAB-MS: 1499.2 (M+1) + . EXAMPLE 10 (HexRGDFP) 2 Lys--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (123 rag, 83% yield). A portion of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 60% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 7 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-G-OH to give the pure peptide as the acetic acid salt (36 mg, white feather-like powder). Amino acid Analysis: Asp 1.9, Pro 2.30, Phe 1.90, Lys 1.02. FAB-MS:1488.1 (M+1) + . EXAMPLE 11 (p)Pht(RGDF--OH) 2 To the solution of TFA.R(Mtr)GDF-OH (40 rag, 0.048 mmol) in DMF (0.8 mL), diisopropylethylamine (45 mL) and the solution of terephthaloyl chloride (4.6 rag, 0.023 retool) in THF (0.5 mL) was added at 0 ° C. The reaction mixture was stirred for 1 hr at 0° C., then for 40 rain at room temperature. The reaction mixture was concentrated under vacuum to give oily residue. The residue was dissolved in a mixture of TFA (0.96 mL), thioanisol (46 μL), and EDT (5 μL), and stirred for 7 hr at room temperature. The solvent was removed by gentle stream of N 2 gas to give an oily residue which was precipitated by the addition of ether. The precipitate was washed with ether (3×15 mL) and purified on a SEPHADEX column (water). The peptide fractions were lyophilized to give a mixture of (p) Pht-RGDF-OH and (p)Pht(RGDF-OH) 2 as white feather-like powder. Two peptides were separated by HPLC: (p)Pht-RGDF-OH [3.5 mg, 23% yield, FABMS: 642.8 (M+1)+]; (p)Pht(RGDF-OH) 2 [9.6 rag, 37% yield, Amino acid analysis: Asp 0.94, Gly 1.00, Arg 1.05, Phe 1.00. FABMS:1117.1 (M+1) + ]. EXAMPLE 12 Suc(RGDF--OH) 2 To the solution of TFA.R(Mtr)GDF-OH (40 rag, 0 048 mmol) in 0.7 N Na 2 CO.sub. 3 (0.7 mL), the solution of succinyl chloride (3.7 mg, 0.024 mmol) in dioxane (0.2 mL) was added at 0 ° C. The reaction mixture was stirred for 1 hr at 0 ° C, then for 40 min at room temperature. The reaction mixture was lyophilized to give white solid. The solid was dissolved in the mixture of TFA (0.96 mL), thioanisol (46 μL), and EDT (5 μL), and stirred for 7 hr at room temperature. The solvent was removed by gentle stream of N 2 gas to give an oily residue which was precipitated by the addition of ether. The precipitate was washed with ether (3×15 mL) and purified on SEPHADEX column (water). The peptide fractions were lyophilized to give a mixture of SucRGDF-OH and Suc(RGDF-OH) 2 as white powder. Two peptides were separated by HPLC Suc-RGDF-OH [ 6.0 mg, 42% yield, FAB-MS: 594.6 (M+1)+]; Suc(RGDF-OH) 2 [3.5 rag, 14% yield, Amino acid analysis: Asp 1.00, Gly 0.96, Arg 1.08, Phe 0.98. FAB-MS:1069.1 (M+1) + ]. EXAMPLE 13 Pda (RGDF--OH) 2 This peptide was prepared as described above for Suc(RGDF-OH) 2 using glutaryl dichloride (4.1 mg, 0.024 mmol) to give two peptides as a white feather-like powder: Pda-RGDF-OH [4.9 rag, 34% yield,FAB-MS: 608.5 (M+1) + ]; Pda(RGDF-OH) 2 [11 mg, 42% yield, Amino acid analysis: Asp 0.91, Gly 1.05, Arg 1.06, Phe 1.00. FAB-MS:1083.3 (M+1) + ]. EXAMPLE 14 Bda(RGDF--OH) 2 This peptide was prepared as described above for Suc(RGDF-OH) 2 using Adipoyl chloride (4.4 mg, 0.024 mmol) to give two peptides as white feather-like powder: Bda-RGDF-OH [8.9 rag, 60% yield,FAB-MS: 622.4 (M+1) + ]; Bda(RGDF-OH) 2 [18 mg, 68% yield, Amino acid analysis: Asp 0.90, Gly 1.01, Arg 1.04, Phe 1.00. FAB-MS: 1097.4 (M+1) + ]. EXAMPLE 15 (GRGDFG) 2 Dab--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (160 mg, 86% yield). A portion (25 mg) of the peptide was purified on a μBondapak C-18 column by using a gradient of 0% CH 3 CN - 0.1% TFA to 66% CH 3 CN - 0.1% TFA over a period of 50 min at a flow rate of 3 mL/min. The fractions containing the desired peptide were collected, lyophilized, dissolved in water, and salt-exchanged on a Sephadex column using 20% acetic acid as the eluent. The elutes were lyophilized to give the pure peptide as the acetic acid salt (10 mg, white feather-like powder). Amino acid analysis: Asp 3.00, Gly 7.83, Arg 3.15, Phe 2.82. FAB-MS:1863.4 (M+1) + . EXAMPLE 16 (RGDF) 2 Dac--RGDF--OH The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (148 mg, 91% yield). A portion (20 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 10% CH 3 CN-0.1% TFA to 60% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 8 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (6 mg, white feather-like powder). Amino acid analysis: Asp 0.94, Gly 1.00, Arg 1.05, Phe 1.00. FAB-MS:1585.4 (M+1) + . EXAMPLE 17 (GRGDF) 2 Lys--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (221 mg, 100 % yield). A portion 30 (30 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 26% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 3 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (10 mg, white feather-like powder). Amino acid analysis: Asp 3.00, Gly 7.17, Arg 3.42, Phe 3.09, Lys 0.66. FAB-MS: 1743.7 (M+1) + . EXAMPLE 18 (GRGDF) 2 Orn--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (232 mg, 100 % yield). A portion (30 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 26% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 3 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab--GRGDF--NH 2 to give the pure peptide as the acetic acid salt (10 mg, white feather-like powder). Amino acid analysis: Asp 3.00, Gly 7.17, Arg 3.42, Phe 3.09, Lys 0.66. FAB-MS:1729.7 (M+1) + . EXAMPLES 19 GRGDFG--(o)Abz--GRGDF--OH The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (105 rag, 80 % yield). The product contained two isolable isomers of the peptide. These isomers (38 mg) were separated on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 40% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 3 mL/min. The fractions containing each of the pure peptides were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the acetic acid salt of pure peptides (17 mg, white feather-like powder). Amino acid analysis: Asp 2.91, Gly 6.69, Arg 3.36, Phe 3.00. FAB-MS:1259.8 (M+1) + . EXAMPLE 20 GRGDFG--(m)Abz--GRGDF--OH The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (114 rag, 88 % yield). A portion (15 mg) of the product was separated on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 40% CH 3 CN-0.1% TFA over a period of 40 min at a flow rate of 3 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (10 mg, white feather-like powder). Amino acid analysis: Asp 2.00, Gly 4.82, Arg 2.30, Phe 2.04. FAB-MS:1259.3 (M+1) + . EXAMPLE 21 GRGDFG--(p)Abz--GRGDF--OH The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (98 mg, 74 % yield). A portion (15 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 40% CH 3 CN-0.1% TFA over a period of 40 rain at a flow rate of 3 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (10 mg, white feather-like powder). Amino acid analysis: Asp 1.96, Gly 4.80, Arg 2.28, Phe 2.00. FABMS: 1259.3 (M+1) + . EXAMPLE 2 GRGDFG--(o)Abz--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (135 rag, 100 % yield). The product contained two isolable isomers of the peptide. These isomers (30 rag) were separated on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 15% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 10 mL/min. The fractions containing the each of the pure peptides were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the acetic acid salt of pure peptides (9 mg, white feather-like powder). Amino acid analysis: Asp 1.07, Gly 5.39, Arg 2.37, o-Abz 0.84, Phe 2.00. FAB-MS: 1258.3 (M+1) + . EXAMPLE 23 GRGDFG--(m)Abz--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (107 rag, 79 % yield). A portion (63 rag) of the product was purified on a μBondaPak C-18 column by using a gradient of 10% CH 3 CN-0.1% TFA to 15% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 10 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (37 mg, white feather-like powder). Amino acid analysis: Asp 1.09, Gly 5.04, Arg 2.19, m-Abz 1.22, Phe 2.00. FAB-MS:1258.9 (M+1) + . EXAMPLE 24 GRGDFG--(p)Abz--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (114 rag, 84 % yield). A portion (41 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 10% CH 3 CN-0.1% TFA to 15% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 10 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (35 mg, white feather-like powder). Amino acid analysis: Asp 1.40, Gly 5.13, Arg 2.59, p-Abz 1.98, Phe 2.00. FAB-MS: 1258.3 (M+1) + . EXAMPLES 25 GRGDSG--(o)Abz--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (118 rag, 86 % yield). The product contained two isolable isomers of the peptide. These isomers (45 rag) were separated on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 16% CH 3 CN-0.1% TFA over a period of 30 min at a flow rate of 10 mL/min. The fractions containing the each pure peptides were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the acetic acid salt of pure peptides (11 mg, white feather-like powder). Amino acid analysis: Asp 1.85, Ser 1.01, Gly 4.55, Arg 2.17, o-Abz 0.58, Phe 1.00. FAB-MS: 1198.9 (M+1) + . EXAMPLE 26 GRGDSG--(m)Abz--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (134 rag, 97 % yield). A portion (62 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 10% CH 3 CN-0.1% TFA to 16% CH 3 CN-0.1% TFA over a period of 30 Bin at a flow rate of 10 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (40 mg, white feather-like powder). Amino acid analysis: Asp 1.36, Ser 0.83, Gly 5.08, Arg 2.09, m-Abz 1.22, Phe 1.00. FAB-MS: 1198.5 (M+1) + . EXAMPLE 27 GRGDBG--(p)Abz--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of peptide as a white solid (137 mg, 100 % yield). A portion (61 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 10% CH 3 CN-0.1% TFA to 16% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 10 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the acetic acid salt of pure peptides (Isomer I, 16 mg, isomer II, 10 mg, white feather-like powder). Amino acid analysis: Asp 1.03, Set 0.84, Gly 5.02, Arg 2.02, p-Abz 1.64, Phe 1.00 FAB-MS: 1198.5 (M+1) + . EXAMPLE 28 GRGDVG--(o)Abz--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (139 mg, 100 % yield). The product contained two isolable isomers of the peptide. These isomers (49 mg) were separated on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 20% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 10 mL/min. The fractions containing the each pure peptides were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the acetic acid salt of pure peptides (16 rag, white feather-like powder). Amino acid analysis: Asp 1.67, Gly 5.67, Arg 2.11, m-Abz 1.04, Val 1.00, Phe 1.00. FAB-MS:1211.2 (M+1) + . EXAMPLE 29 GRGDVG--(m)Abz--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (127 mg, 93 % yield). A portion (59 mg) of the product was purified on a μBondaPak C-18 column by using a gradient of 10% CH 3 CN-0.1% TFA to 20% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 10 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (39 rag, white feather-like powder). Amino acid analysis: Asp 1.67, Gly 5.67, Arg 2.11, m-Abz 1.04, Val 1.00, Phe 1.00. FAB-MS: 1211.2 (M+1) + . EXAMPLE 30 GRGDVG--(p)Abz--GRGDF--NH 2 The synthesis with 0.1 mmol scale gave the TFA salt of the peptide as a white solid (126 mg, 91% yield). A portion (50 mg) of the product was purified on a μBondaPak C-18 column h by using a gradient of 10% CH 3 CN-0.1% TFA to 20% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 10 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (27 mg, white feather-like powder). Amino acid analysis: Asp 1.81, Gly 5.27, Arg 1.96, p-Abz 1.19, Val 1.00, Phe 0.94. FAB-MS: 12 11.0 (M+1) + . EXAMPLE 31 (BzRGDF) 2 Dac--RGDF-OH The synthesis with 0.05 mmol scale gave the TFA salt of peptide as a white solid (72 mg, 80% yield). A portion (10 rag) of the product was purified on a μBondaPak C-18 column by using a gradient of 0% CH 3 CN-0.1% TFA to 55% CH 3 CN-0.1% TFA over a period of 30 rain at a flow rate of 8 mL/min. The fractions containing the pure peptide were treated as described above for (GRGDFG) 2 Dab-GRGDF-NH 2 to give the pure peptide as the acetic acid salt (3.0 mg, white feather-like powder). Amino acid analysis: Asp 1.00, Gly 0.95, Arg 1.01, Phe 0.93. FAB-MS:1793.4 (M+1) + . Thus, while we have described what are presently the preferred embodiments of the present invention, other and further changes and modifications could be made without departing from the scope of the invention, and it is intended by the inventors to claim all such changes and modifications.

The present invention provides synthetic antiaggregatory agents for preventing inhibition of fibrinogen-platelet binding. These anti-aggregatory agents have the general formulas (1)-(5). H--[--(AA.sub.i).sub.i --R--G--D--(AA.sub.j).sub.j --].sub.n --Cx (1) [Ri--C(O)--R--G--D--(AA.sub.j).sub.j --].sub.n --CX (2) Cy--[--AA.sub.i).sub.i --R--G--D--(AA.sub.j).sub.i --].sub.n --Z (3) H--[--(AA.sub.i).sub.i --R--G--D--(AA.sub.j).sub.j --].sub.n --CZ--[--(AA k ) k --R--G--D--(AA l ) l --] m --Z (4) [R.sub.1 --C(O)--R--G--D--(AA.sub.i).sub.i --].sub.n --CZ[--(AA j ) j ]--R--G--D--(AA k ) k --] m --Z (5) in which: R=Arg; G=Gly; D=Asp; AA i , AA j , AA k and AA l = alpha-, beta- and omega-amino acid residues; (AA i ) i (AA j ) j =peptide chains having the same or different amino acid residues; (AA k ) k =peptide chains having the same or different amino acid residues; (AA l ) l =peptide chains having the same or different amino acid residues; i and j =integers 0-20; m =an integer 1-10; n=an integer 2-10; Cx =a conjugator bearing at least two amine residues in a molecule having 1-30 carbon atoms, i.e, diamines, triamines, tetramines, and polyamines, which can have other functional groups in the molecule; Cy =a conjugator bearing at least two carboxyl residues in a molecule having 1-30 carbon atoms, i.e., aliphatic, aromatic, heteroaromatic, cycloalkyl dicarboxylic acid, tricarboxylic acid, and polycarboxylic acid residues, which can have other functional groups in the molecule; Cz = a conjugator bearing at least one amine residue and one carboxyl residue in an aromatic or a cycloalkyl skeleton, having 1-30 carbon atoms, i.e., aromatic, heteroaromatic and cycloalkyl amino carboxylic acid, diamino carboxylic acid, diamino dicarboxylic acid, and ployamino polycarboxylic acid residues; R 1 =an alkyl, aromatic, heteroaromatic, or cycloalkyl group having 1-30 carbons, which can have other functional groups in the molecule; and Z=carboxyl, amide, N-substituted amide, hydrazide, N-substituted hydrazide, or ester group.

BACKGROUND OF THE INVENTION This invention relates to multilamp photoflash devices having circuit means for sequentially igniting the flashlamps and, more particularly, to improved means for permitting reliable flashing of an array of photoflash lamps, particularly arrays operated by comparatively long duration, low voltage firing pulses. Numerous multilamp photoflash arrangements with various types of sequencing circuits have been described in the prior art, particularly in the past few years. Series and parallel-connected lamp arrays have been shown which are sequentially fired by mechanical switching means, simple electrical circuits, switching circuits using the randomly varied resistance characteristics of the lamps, arc gap arrangements, complex digital electronic switchin circuits, light-sensitive switching means and heat-sensitive switching devices which involve melting, fusing or chemical reaction in response to the radiant energy output of an adjacently located flashlamp. The present invention is concerned with an improved radiant-energy-activated switching means useful in a relatively inexpensive photoflash unit of the disposable type. In particular, the present switching means is particularly advantageous in photoflash arrays emloying lamps adapted to be ignited sequentially by successively applied firing pulses from a low voltage source. A currently marketed eight-lamp photoflash unit employing radiation switches is described in U.S. Pat. Nos. 3,894,226 and 4,017,728 and referred to as a flip flash. A ten lamp version is described in U.S. Pat. Nos. 4,156,269 and 4,164,007. The unit comprises a planar array of high voltage flashlamps mounted on a printed circuit board with an array of respectively associated reflectors disposed therebetween. The circuit board comprises an insulating sheet of plastic having a pattern of conductive circuit traces, including terminal contacts, on one side. The flashlamp leads are electrically connected to the circuit traces, such as by means of eyelets, and the circuitry on the board includes a plurality of solid state switches that chemically change (convert) from a high to low resistance so as to become electrically conducting after exposure to the radiant heat energy from an ignited flashlamp operatively associated therewith. The purpose of the switches is to promote lamp sequencing and one-at-a-time flashing. One type of solid state switch which operates in this manner is described in U.S. Pat. No. 3,458,270 of Ganser et al, in which the use of silver oxide in a polyvinyl binder is taught as a normally open radiant energy switch. Upon radiant heating, the silver oxide decomposes to give a metallic silver residue which is electrically conductive. Silver carbonate has also been used in lieu of or together with silver oxide. For example, U.S. Pat. No. 3,990,833, Holub et al, describes a mass of a composition comprising silver oxide, a carbon-containing silver salt and a humidity resistant organic polymer binder, the switch mass being deposited on a circuit board so as to interconnect a pair of spaced apart electrical terminals formed by the printed circuitry thereof. A similar type radiation switch exhibiting an even greater humidity resistance at above normal ambient temperatures is described and claimed in U.S. Pat. No. 3,990,832, Smialek et al, which describes the use of a particular stabilizer additive, such as an organic acid, to preclude or reduce the tendancy of the silver source in the switch material from premature conversion to a low electrical resistance when exposed to ambient humidity conditions. U.S. Pat. No. 3,951,582, Holub et al, describes a similar type switch with a colored coating, and U.S. Pat. No. 4,087,233, Shaffer, describes a switch composition comprising silver carbonate, a binder, and an oxidizer such as barium chromate, which is particularly resistant to high relative humidity and above normal ambient temperatures. U.S. Pat. No. 3,969,065, Smialek, describes a solid state switch comprising a mixture of solid copper salt with a humidity resistant organic polymer binder and a finely divided metal reducing agent, and a U.S. Pat. No. 3,969,066, Smialek et al, describes a switch comprising a mixture of finely divided cupric oxide with a humidity resistant organic polymer binder. The use of a glass bead filler in a solid state switch is described in U.S. Pat. No. 4,080,155 of Sterling for preventing the switch material from being burned off or blown off the circuit board. An improved switch composition which avoids these problems is described in copending application Ser. No. 021,398, filed Mar. 19, 1979, and assigned to the present assignee. The improved burn-off prevention and reduced heat absorption are attained by replacing part of the silver carbonate and/or silver oxide in the switch composition with a proportion of electrically nonconductive inert particulate solids which comprise as much as 25-65% by weight of the total dried composition. All of the aforementioned switch compositions have been described with respect to use in photoflash arrays employing high voltage type lamps adapted to be ignited sequentially by successively applied high voltage firing pulses from a source such as a camera-shutter-actuated piezoelectric element. Accordingly, none of these prior patents or applications mention a specific switch closure interval, i.e., the time of conversion from a high electrical resistance to a low electrical resistance upon exposure to radiation emitted from an adjacent flashlamp. Consideration of such switch closure, or conversion, time has not been necessary in a high voltage piezo-fired array since the electrical firing pulse duration is less than 10 microseconds, whereas the normally open radiation switch is not activated until 5-10 milliseconds; i.e., the conversion time is 5 to 10 milliseconds. If it is desired to use such normally open radiation switches in a low voltage photoflash array intended for operation with a typical camera actuated, battery powered pulse source, the reliability of proper lamp sequencing can be adversely affected. In a low voltage array, the electrical pulse duration can extend to a period longer than the conversion time of the normally open radiation switch. If the pulse duration is long enough, a second lamp will inadvertently flash, thereby causing the loss of that lamp in the intended useful sequence of lamp operation. Accordingly, it is desirable to have a normally open radiation switch that will activate (be converted) after the camera pulse has ended. By way of specific example, consider a low voltage camera having a pulse duration which varies from 4 to 10 milliseconds. In such an application, a switch conversion time of greater than about 12 milliseconds would be required. For these purposes, switch conversion time is defined as the elapsed time between the start of the firing pulse, and thus the high electrical resistance (open circuit) state of the switch mass, and the time at which the switch resistance reaches a predetermined low resistance state, which functions as a closed circuit in the operating application. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a photoflash unit having improved switching means for permitting reliable flashing of an array of photoflash lamps. A principle object of the invention is to provide an improved, normally open radiation-actuated electrical switch for use in devices such as photoflash arrays and in which the switch composition is formulated to provide a predetermined conversion time of about 12 milliseconds or greater. A further object is to provide an improved solid-state switch composition which more readily facilitates control of switch conversion time. These and other objects, advantages and features are attained, in accordance with the invention, by appropriate selection of the composition of the switch admixture to provide a predetermined conversion time of about 12 milliseconds or greater. A preferred conversion time is from about 12 to 19 milliseconds. Typically the switch admixture comprises silver carbonate and/or silver oxide, silver-coated glass beads, and a binder. The use of a selected proportion of silver-coated glass beads as a conductivity-enhancing filler in a silver compound switch is described in copending application Ser. No. 148,358 filed concurrently herewith and assigned to the present assignee. According to one embodiment of the invention, the proportion of binder in the dried composition by weight of the admixture is in the range of 10% to 15%, and the conversion time and resistance of the switch after conversion are directly related to the proportion of binder. In another embodiment, the proportion of silver carbonate in the dried composition by weight of the admixture is in the range of 45% to 0%, and the proportion of silver oxide in the dried composition by weight of the admixture is in the range of 0% to 45%; in this case, the conversion time and resistance of the switch after conversion are directly related to the proportion of silver carbonate replacing silver oxide in the mixture. In yet another embodiment, the switch admixture further includes 11% to 40% of electrically non-conductive inert particulate solids comprising one or more members selected from the group consisting of titanium dioxide, aluminum dioxide, aluminum phosphate, barium sulfate, and silicon dioxide. In this instance, the conversion time and the resistance of the switch after conversion are directly related to the proportion of the inert particulate replacing silver carbonate and/or silver oxide in the mixture; accordingly, this approach is not suitable for applications when the maintenance of a very low post-conversion resistance is critical. In yet another embodiment, the composition of the switch admixture further includes 50% to 60% silver-coated metal beads, and the conversion time of the switch is directly related to the proportion of silver-coated metal beads replacing silver-coated glass beads in the mixture. The resistance of such a switch after conversion, however, is inversely related to the proportion of silver-coated metal beads replacing silver-coated glass beads in the mixture. BRIEF DESCRIPTION OF THE DRAWINGS This invention will be more fully described hereinafter in conjunction with the accompanying drawings in which: FIG. 1 is a front elevation of a multilamp photoflash unit in which the present invention is employed; FIG. 2 is a front elevation of a circuit board used in the unit of FIG. 1, the circuit board including radiation connect switches in accordance with the invention; FIG. 3 is an enlarged fragmentary detal view of a proportion of the circuit board of FIG. 2 showing the switching arrangement associated with one of the lamps; and FIG. 4 is an enlarged fragmentary schematic cross-sectional view taken along 4--4 of FIG. 1. DESCRIPTION OF PREFERRED EMBODIMENT FIG. 1 illustrates a multilamp photoflash unit of the general type described in the aforementioned U.S. Pat. No. 4,164,007. This unit is similar in general operation to that described in the aforementioned U.S. Pat. No. 4,017,728, except that the construction has been modified to include additional lamps in a housing having the same outer dimensions. Whereas the unit described in U.S. Pat. No. 4,017,728 included a planar array of eight flashlamps (two groups of four) with associated reflector cavities provided in a single reflector member, the present unit comprises a planar array of ten flashlamps 11-15 and 21-25 mounted on a printed circuit board 43 (see FIG. 2) with an array of respectively associated reflector cavities 11'-15' and 21'-25' disposed therebetween. For low voltage pulse operation, the lamps can be of the filament type. Lamp 24 is omitted in FIG. 1 to show reflector cavity 24', which is typical of all the reflector cavities. The lamps are horizontally disposed and mounted in two parallel columns, with the lamps of one column staggered relative to the lamps of the other column. Each of the lamps has a pair of lead-in wires (not shown) connected to the printed circuitry on board 43 by respective eyelets 11a and 11b, etc., or solder joints. The column of lamps 15, 13, 11, 22 and 24 are positioned with their respective bases interdigitated with the bases of the adjacent column comprising 14, 12, 21, 23 and 25, the bases of one column thereby facing the bases of the adjacent column. The reflector cavities are provided on a pair of strip-like panels 40 and 41 which are conveniently separable for assembly purposes. The array is provided with a plug-in connector tab 16 at the lower end thereof which is adapted to fit into a camera or flash adaptor. A second plug-in connector tab 16' is provided at the top end of the unit, whereby the array is adapted to be attached to the camera socket in either of two orientations, i.e., with either the tab 16 or the tab 16' plugged into the socket. The lamps are arranged in two groups of five disposed on the upper and lower halves, respectively, of the elongated, rectangular-shaped array. Upper group 17 comprises lamps 11-15 and lower group 18 includes lamps 21-25; the reflector cavities 11', etc., are disposed behind the respective lamps so that as each lamp is flashed, light is projected forwardly of the array. The lamps are arranged and connected so that when the array is connected to a camera by the connector tab 16 only the upper group 17 of lamps will be flashed. By this arrangement, only lamps relatively far from the camera lens axis are flashable, thus reducing the undesirable " red-eye" effect. The construction of the array comprises front and back housing members 36 and 37 (only the outer periphery of the back housing member is visible in FIG. 1), which preferably are made of plastic and are provided with interlocking members (not shown) which can be molded integrally with the housing members and which lock the housing members together in final assembly to form a unitary flash array structure. The front housing member 36 is a rectangular concavity and the back housing member 37 is substantially flat and includes integral extensions 39 and 39' at the ends thereof which partly surround and protect the connector tabs 16 and 16' and also function to facilitate mechanical attachment to the camera socket. Sandwiched between the front and back housing members 36 and 37, in the order named, are the flashlamps 11, etc., the pair of adjacent strip-like reflector panels 40 and 41 (preferably each being aluminum-coated plastic molding) shaped to provide the individual reflector cavities 11' etc., a transparent electrically insulating sheet 42 (shown only in FIG. 4), the printed circuit board 43 provided with integral connector tabs 16 and 16', and an indicia sheet (not shown) which may be provided with information and trademarks, and other indicia such as flash indicators located behind the respective lamps and which change color due to heat and/or light radiation from a flashing lamp, thus indicating at a glance which of the lamps have been flashed and not flashed. Window means, such as openings 67, are provided in each of the reflector cavities 11', etc., behind the lamp aligned therewith. The circuit board 43 is provided with corresponding openings 30 to facilitate radiation from the flashlamps reaching the flash indicators. The rear housing member 37 is transparent (either of clear material or provided with window openings) to permit viewing of the indicia on the indicia sheet. The front housing member 36 is transparent, at least in front of the lamps 11, etc., to permit light from the flashing lamps to emerge forwardly of the array, and may be tinted to alter the color of the light from the flashlamps. The height and width of the rectangular array are substantially greater than its thickness, and the height and width of the reflector panels 40, 41, the insulating sheet 42, and the circuit board 43 are substantially the same as the interior height and width of the housing member 36 to facilitate holding the parts in place. Referring to both FIGS. 1 and 2, the tab 16, which is integral with the circuit board 43, is provided with a pair of electrical terminals 31 and 32, and similarly the tab 16' is provided with a pair of terminals 31' and 32', for contacting terminals of a camera socket for applying firing voltage pulses to the array. The circuit board 43 has a "printed circuit" thereon, as shown in FIG. 2, for causing sequential flashing of the lamps by firing voltage pulses applied to the terminals 31, 32, 31' and 32'. The top and bottom halves of the printed circuitry preferably are reverse mirror images of each other. The lead wires (not shown) of the lamps 11 etc., (FIG. 1) may be attached to the circuit board 43 in various ways such as by means of crimped metal eyelets 11a, 11b, etc., placed through openings in the board or, as preferred for low voltage circuits, by solder joints to conductive pads forming part of the circuit pattern. The circuit located on the upper half of the circuit board of FIG. 2 and activated by the pair of input terminals 31 and 32 includes five lamps 11-15 arranged in parallel across the input terminals and four normally closed (N/C) radiant-energy-activated disconnect switches 71, 72, 73 and 74 each connected in series with a respective one of the lamps 11-14. Each N/C disconnect switch is responsive to the flashing of the lamp with which it is series-connected to form an open circuit. The circuit also includes four normally open (N/O) radiant-energy-activated connect switches 61 62, 63 and 64 for providing sequential flashing of the lamps 11-15 in response to firing pulses successively applied to the input terminals 31 and 32. Each N/O connect switch is responsive to the flashing of an associated lamp to form a closed circuit condition. One terminal (lead-in wire) of each of the lamps 11-15 is connected in common by means of an electrical "ground" circuit run 50 to input terminal 31. The "ground" circuit run 50 includes the terminals 31 and 31' and makes contact with one of the connector junctions for each of the lamps. As described in the previously referenced U.S. Pat. No. 4,017,728, Audesse et al, each of the N/C disconnect switches 71-74 comprises a length of electrically conductive, heat shrinkable, polymeric material which is attached to the circuit board at both ends, with its midportion spatially suspended over an aperture 30 to avoid contact with the heat absorbing surfaces of the circuit board. This arrangement maximizes the speed with which the shrinking and separation of the midportion of the switch element occurs upon its bein heated by the radiant output of an ignited flashlamp. The first lamp to be fired, namely, lamp 11, is connected directly across the input terminals 31 and 32 via the N/C disconnect switch 71. The second through fourth N/O connect switches, namely, 62, 63 and 64 are series connected in that order with lamp 15, which is the fifth and last lamp to be fired, across the input terminals 31 and 32. Further, the third lamp to be fired (lamp 13) is series connected with N/O switch 62, and the fourth lamp to be fired (lamp 14) is connected in series with N/O switch 63. In order to limit the resistance build-up caused by additional series N/O switches, and any possible circuit discontinuity caused by misplacement of the first N/C switch 71, the first N/O switch to be activated (switch 61) is series-connected with the second lamp to be fired (lamp 12) across the input terminals 31 and 32 but parallel-connected with the above-mentioned series combination of N/O switches 62-64 and lamp 15. Terminal 32 is part of a conductor run 51 that terminates at three different switches, namely, the N/C disconnect switch 71, the N/O connect switch 61, and the N/O connect switch 62. The other side of switch 71 is connected to lamp 11 via circuit run 52 and eyelet (or solder junction) 11a. Circuit run 53 connects switches 61 and 72, and circuit run 54 connects the other side of switch 72 to lamp 12 via eyelet (or solder junction) 12a. A circuit run 55 interconnects switches 62, 73 and 63 while the other side of switch 73 is connected to lamp 13 via circuit run 56, and eyelet (or solder junction) 13b. Switches 63, 74 and 64 are interconnected by a circuit run 58 and eyelet (or solder junction) 14a. Finally, a circuit run 59 connects the other side of switch 64 to lamp 15 via eyelet (or solder junction) 15b. For high voltage pulse source applications, the aforementioned circuit runs have typically comprised a silk-screened pattern of silver-containing conductive material. The compositions of the N/O connect switch material according to the present invention and copending application Ser. No. 148,358 however, permit use of a circuit board 43 having circuit runs formed of die-stamped aluminum, thereby providing significant cost advantages. For example, U.S. Pat. No. 3,990,142 describes a die-stamped printed circuit board, and copending applications Ser. Nos. 131,614 and 131,711 both filed Mar. 19, 1980 and assigned to the present assignee, describe die-stamped circuit boards for photoflash devices. If operation from a low voltage pulse source is intended, the circuit runs of FIG. 2 are typically formed of copper, either etched or die-stamped. The radiant-energy-activated N/O connect switches 61-64 are in contact with and bridge across the circuit runs that are connected to them. More specifically, each N/O switch comprises a mass of material interconnected to a pair of spaced apart electrical terminals in the circuits. FIGS. 3 and 4 illustrate this for switch 61. The material for the connect switch is selected to be of the type initially having an open circuit or high resistance, the resistance thereof becoming converted to a lower value when the material receives radiation in the form of heat and/or light from a respective adjacent lamp, upon the lamp being flashed. For this purpose, each of the connect switches is respectively positioned behind and near to an associated flashlamp 11-14. To facilitate radiation transfer from the flashlamp to its corresponding N/O connect switch, each of the reflectors includes a window means, such as an opening 67, in alignment with the respective radiation connect switch. Each of these connect switches has a composition according to the invention, as will be described hereinafter, and upon receiving heat and/or light radiation from the adjacent lamp when it is flashed, converts from an open circuit (high resistance) to a closed circuit (lower resistance) between its switch terminals on the circuit board. As described in U.S. Pat. No. 4,130,857, Brower, the high resistance material employed in providing the N/O connect switches 61-64 is also disposed on and about each of the ends of the N/O disconnect switches. For example, as illustrated in FIG. 3, the disconnect switch 71 is attached to circuit board 43 so as to extend laterally across aperture 30 with respect to the lamp. Conductive trace 53 extends to provide one electrical terminal for a connect switch 61 while a trace 51 provides the other connect switch terminal. In addition, trace 51 is carried over one end of strip 71, and trace 52 contacts the other end of strip 71. In this instance, patches 78 and 79 of high resistance material cover each end of the conductive strip 71 to shield the circuit run carry-over regions from abrasion during the manufacturing process and further secure the strip to the circuit board. In addition to this mechanical protection, the high resistance patches 78 and 79 provide insulation to prevent shorting or spark-over between the strip ends and the nearby circuit traces 53 and 50 (also see FIG. 2). In this position, the patches 78 and 79 are masked by the reflector during flashing. Although there are other methods of insulating the disconnect switch ends, such as by a coat of insulating resin, use of connect switch paste eliminates a production process by combining the switch-depositing step and the insulating step. As has been explained, the lower portion of the circuit board contains a substantially reverse mirror image of the same circuitry shown in the upper part of the circuit board, and therefore will not be described in detail. It will be noted that the circuit runs from the plugged in terminals 31 and 32 at the lower part of the circuit board extend upwardly so as to activate the circuitry in the upper half of the circuit board. Similarly when the unit is turned around and tab 16' is plugged into a socket, the circuit board terminals 31' and 32' will be connected to activate the lamps which then will be in the upper half of the circuit board, and hence in the upper half of the flash unit. This accomplishes the desirable characteristic whereby only the group of lamps relatively farthest away from the lens axis will be flashed, thereby reducing the possibility of the phenomenon known as "red-eye". The circuit on the circuit board 43 functions as follows. Assuming that none of the five lamps in the upper half of the unit have been flashed, upon occurrence of the first firing pulse applied across terminals 31 and 32, this pulse will be directly applied to the lead-in wires of the first connected flashlamp 11, whereupon the lamp 11 flashes and becomes an open circuit between its lead-in wires. Heat and/or light radiation from the flashing first lamp 11 is operative via its respective reflector aperture to activate the N/C disconnect switch 71 and the N/O connect switch 61. As a result, the normally closed disconnect switch 71 is operative in response to the radiation from the lamp to rapidly provide a reliable open circuit to high voltages and thus electrically remove lamp 11 from the circuit, whereby the subsequent lamps 12-15 are unaffected by short circuiting or residual conductivity in lamp 11. The radiation causes the normally open connect switch 61 to become a closed circuit (or a low value of resistance), thereby connecting the circuit board terminal 32 electrically to the second lamp 12 via the normally closed disconnect switch 72. By the time this occurs, the firing pulse should have diminished to a value insufficient to cause the second lamp 12 to flash. Accordingly, to assure reliable operation in this respect, the composition of the normally open connect switch mass is selected to provide a predetermined minimum conversion time, as shall be described hereinafter. When the next firing pulse occurs, it is applied to the lead-in wires of the second lamp 12 via the now closed connect switch 61 and disconnect switch 72, whereupon the second lamp 12 flashes, thereby causing disconnect switch 72 to rapidly provide an open circuit and causing connect switch 62 to assume a low resistance. Once switch 62 has been activated the resistance of the N/O connect switch 61 is bypassed along with any potential discontinuity caused by the N/C disconnect switch 71. When the next firing pulse occurs, it is applied via now closed connect switch 62 and disconnect switch 73 to the third lamp 13, thereby firing that lamp, whereupon the radiation from lamp 13 activates disconnect switch 73 to rapidly provide an open circuit and causes connect switch 63 to become essentially a closed circuit across its terminals. The next firing pulse applied, via now closed connect switch 63 and disconnect switch 74 to the lead-in wires of the fourth flashlamps 14, thereupon causing the lamp to flash. The radiation from lamp 14 activates the disconnect switch 74 to rapidly provide an open circuit and causes connect switch 64 to become essentially a closed circuit across its terminals. Thus, the next firing pulse will be applied, via now closed connect switch 64 to the lead-in wires of the fifth flashlamp 15, thereupon causing the lamp to flash. Since this lamp is the last lamp in the active circuit, it does not matter whether its lead-in wires are an open or closed circuit after flashing. When the flash unit is turned around and the other connector tab 16' attached to the camera socket, the group 18 of the lamps that then becomes uppermost and farthest away from the lens axis will be in the active circuit and will be flashed in the same manner as has been described. In a low voltage embodiment, the lamps 11, etc., are of the filament type and the firing pulses are provided from a camera-actuated battery supply of a few volts, e.g., 3 to 45 volts having a pulse duration of up to ten milliseconds. In accordance with the present invention, each of the solid-state radiation connect switches 61-64 is a dried mass of material having a selected composition comprising an admixture of silver-carbonate and/or silver oxide, silver-coated glass beads and a binder, such as polystyrene resin. The coated glass beads can be selected to have a silver content of from about 4% to 12% as a dried weight proportion of the beads. Such glass beads are commercially available, e.g., from Potters Industries Incorporated, Hasbrouck, N.J., in the form of spheres, spheroids, or oblong spheroids having an average diameter of 6-125 microns and preferably 10-50 microns average diameter. The composition may further include fillers and stabilizers. For example, a proportion of barium chromate may be included to enhance environmental stability as described in U.S. Pat. No. 4,087,233. Further, for high voltage circuit applications, the switch composition may include a high proportion of non-conductive inert particulate solids by use of a filler, such as titanium dioxide, as described in copending application Ser. No. 021,398 filed Mar. 19, 1979 and assigned to the present assignee. Other inert fillers that can be used are aluminum oxide, aluminum phosphate, barium sulfate, and silicon dioxide. In accordance with yet another aspect of the invention, the switch composition may further include a selected proportion of silver-coated metal beads. Such metal beads are commercially available, e.g., from Boronite, Bloomfield, N.J.; we prefer substrate metals of copper or nickel coated with about 6% silver and having a bead size of 200 mesh or finer. As described hereinbefore, the firing pulse duration from a camera-actuated low voltage (e.g., 3 to 45 volts) battery source, according to one application embodiment, varies from 4 to 10 milliseconds. We have found that for reliable operation of a photoflash array from such a low voltage pulse source, the conversion time for the normally open radiation switch should be greater than about 12 milliseconds, and preferably lie in the range from 12 to 19 milliseconds. As previously stated, conversion time may be defined as the elapsed time between the start of a firing pulse, when the switch mass has a sufficiently high electrical resistance to present an open circuit, and the time at which the switch resistance reaches a sufficiently low value to present a closed circuit, e.g, about 0.5 ohms or less in a low voltage operated circuit. According to the present invention, the desired switch conversion time can be predetermined by appropriate selection of the constituents and proportions of the switch composition. For example, an increase in the percentage of binder increases the conversion time and increases the final resistance of the switch. Although a range of 12% to 14% binder is optimum, the binder can be varied from 10% to 15%, according to the requirements of timing and resistance of the flash system. A specific example of the aforementioned effects is illustrated in Table 1 below, wherein the binder employed is polystyrene resin. TABLE I______________________________________ Post Conversion% % Ag-Coated % Binder Timing ResistanceAg.sub.2 CO.sub.3 beads Dry Wgt. msec. Ohm______________________________________50 40 10 9.8 0.0750 35* 15 15.7 0.15______________________________________ *Note that a change in the percentage of silvercoated glass beads did not significantly change the timing characteristics of the switch, in a test designed to check that possibility. Replacing silver oxide with silver carbonate slows the switch conversion time and increases the switch resistance. A mixture of the two silver compounds results in timing and resistance characteristics somewhere between the two extremes. The change in timing in this instance is believed to result from the silver carbonate having to breakdown into silver oxide and then into metallic silver, rather than breaking down directly into metallic silver as does the silver oxide. The change in resistance results from the higher percentage of metallic silver per given weight of silver oxide, as compared to the percent of metallic silver in silver carbonate. A specific example of the aforementioned effects is illustrated in Table 2 below. TABLE 2______________________________________ Post Conversion % % Ag-Coated % Timing Resistance% Ag.sub.2 CO.sub.3 Ag.sub.2 O Beads Binder msec. Ohm______________________________________45.0 0.0 40 15.0 16.9 0.6422.5 22.5 40 15.0 16.2 0.530.0 45.0 40 15.0 12.2 0.29______________________________________ The addition of an inert filler slows the switch conversion time and increases switch resistance. Hence, this can be used only where the need for a very low post conversion resistance is not critical. As a specific example, titanium dioxide was used as a filler and the results are illustrated in Table 3 below. TABLE 3______________________________________ % Post Conversion% Ag-Coated % % Timing ResistanceAg.sub.2 CO.sub.3 Beads TiO.sub.2 Binder msec. Ohm______________________________________50.0 40.0 0.0 10.0 9.8 0.0740.0 40.0 10.0 10.0 10.9 0.1030.0 40.0 20.0 10.0 16.3 0.45______________________________________ Replacing the silver-coated glass beads with silver-coated metal beads was discovered to slow the switch conversion time but to decrease switch resistance. The increase in switch conversion time can be attributed to the heat-sinking effect of the metal beads as compared to the glass beads. The decrease in resistance results from the metal being a conductor, while the glass beads are an insulator without the silver coating. Note that Table 4 below shows a higher percentage of silver-coated metal beads when measured by weight, but the silver-coated metal beads and the silver-coated glass beads are of equal volume. This factor also affects the weight percentage of binder, which is indicated as much lower in the metal bead composition even though approximately equivalent in volume to the binder employed in the glass bead composition (50-40-10). In this particular instance, the silver coated metal beads are 200 mesh or finer copper beads covered with 6% silver (Boronite #53-15). TABLE 4______________________________________ % Post Ag-Coated % Conversion% Glass % Ag-Coated Bin- Timing ResistanceAg.sub.2 CO.sub.3 Beads Metal Beads der msec. Ohm______________________________________50.0 40.0 0.0 10.0 9.8 0.0734.0 0.0 59.0 6.8 12.2 0.02______________________________________ In each of the above cases, the switch mixture was made into a paste by ball milling in a suitable solvent such as butyl cellosolve acetate. The solids content may be adjusted to suit the method of switch application. For silk screening over circuit boards, we prefer to adjust the solids content to about 74%. This mixture is deposited as a mass of material across respective conductor run terminations, as represented by patches 61-64. For example, FIGS. 3 and 4 illustrate switch 61 wherein such a mixture is deposited as a mass bridging conductor runs 53 and 51. Switches 61-64 having this patch composition consistently provided with desired conversion times and post-conversion resistance values across the respective conductor run terminations. Although only polystyrene resin was mentioned herinbefore for use as a binder material, other useful binders include cellulose esters, cellulose ethers, polyalkylacrylates, polyalkylemethacrylates, styrene copolymers, vinyl polymers, and polycarbonate. Accordingly, although the invention has been described with respect to specific embodiments it will be appreciated that modifications and changes may be made by those skilled in the art without departing from the true spirit and scope of the invention. For example, the described radiation switches are not limited to use in a planar photoflash array of the type illustrated but are equally suitable for use in photoflash units having linear arrays of lamps, whether of vertical or horizontal arrangement, powered by a connector having two or more terminals.

A photoflash unit having a plurality of flashlamps mounted on a printed circuit board containing circuitry for sequentially igniting the flashlamps in response to successive firing pulses applied thereto. The circuitry includes a plurality of solid-state switches capable of being activated by radiant energy generated during flashing of lamps located adjacent to respective switches. Initially, each of the switches has a resistance sufficiently high to provide an open circuit to the applied firing pulses, and after being activated by radiation, the switch undergoes chemical conversion to a conductive state over a finite time interval. The switches are prepared from compositions comprising admixtures of silver carbonate and/or silver oxide, silver-coated glass beads and a binder; the admixtures may also include electrically non-conductive particulate solids, such as titanium dioxide, and/or silver-coated metal beads. The constituents and proportions of the switch compositions are selected to provide a predetermined conversion time of twelve milliseconds or greater, thereby permitting reliable functioning with comparatively long duration, low voltage firing pulses.

RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 13/732,265 (now U.S. Pat. No. 8,629,552), filed Dec. 31, 2012, which is a continuation of U.S. patent application Ser. No. 13/286,558 (now U.S. Pat. No. 8,358,004), filed Nov. 1, 2011, which is a continuation of U.S. patent application Ser. No. 13/111,537 (now U.S. Pat. No. 8,121,331), filed May 19, 2011, which is a continuation of U.S. patent application Ser. No. 11/741,881 (now U.S. Pat. No. 8,018,049), filed Apr. 30, 2007, which is a divisional of U.S. patent application Ser. No. 10/921,747 (now U.S. Pat. No. 7,434,305), filed Aug. 19, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 09/886,854 (now U.S. Pat. No. 7,166,910), filed Jun. 21, 2001, which claims the benefit of U.S. Provisional Patent Application No. 60/253,543, filed Nov. 28, 2000. U.S. patent application Ser. No. 13/668,035, filed Nov. 2, 2012, U.S. patent application Ser. No. 13/668,103, filed Nov. 2, 2012, U.S. patent application Ser. No. 13/732,120, filed Dec. 31, 2012, U.S. patent application Ser. No. 13/732,179, filed Dec. 31, 2012, U.S. patent application Ser. No. 13/732,205, filed Dec. 31, 2012, and U.S. patent application Ser. No. 13/732,232, filed Dec. 31, 2012, are also continuations of U.S. patent application Ser. No. 13/286,558 (now U.S. Pat. No. 8,358,004). These applications are hereby incorporated by reference herein in their entireties for all purposes. TECHNICAL FIELD This patent relates generally to a housing for a transducer. More particularly, this patent relates to a silicon condenser microphone including a housing for shielding a transducer. BACKGROUND OF THE INVENTION There have been a number of disclosures related to building microphone elements on the surface of a silicon die. Certain of these disclosures have come in connection with the hearing aid field for the purpose of reducing the size of the hearing aid unit. While these disclosures have reduced the size of the hearing aid, they have not disclosed how to protect the transducer from outside interferences. For instance, transducers of this type are fragile and susceptible to physical damage. Furthermore, they must be protected from light and electromagnetic interferences. Moreover, they require an acoustic pressure reference to function properly. For these reasons, the silicon die must be shielded. Some shielding practices have been used to house these devices. For instance, insulated metal cans or discs have been provided. Additionally, DIPs and small outline integrated circuit (SOIC) packages have been utilized. However, the drawbacks associated with manufacturing these housings, such as lead time, cost, and tooling, make these options undesirable. SUMMARY OF THE INVENTION The present invention is directed to a silicon condenser microphone package that allows acoustic energy to contact a transducer disposed within a housing. The housing provides the necessary pressure reference while at the same time protects the transducer from light, electromagnetic interference, and physical damage. In accordance with an embodiment of the invention a silicon condenser microphone includes a transducer and a substrate and a cover forming the housing. The substrate may have an upper surface with a recess formed therein allowing the transducer to be attached to the upper surface and to overlap at least a portion of the recess thus forming a back volume. The cover is placed over the transducer and includes an aperture adapted for allowing sound waves to reach the transducer. Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a first embodiment of a silicon condenser microphone of the present invention; FIG. 2 is a cross-sectional view of a second embodiment of a silicon condenser microphone of the present invention; FIG. 3 is a cross-sectional view of a third embodiment of a silicon condenser microphone of the present invention; FIG. 4 is a cross-sectional view of the third embodiment of the present invention affixed to an end user circuit board; FIG. 5 is a cross-sectional view of the third embodiment of the present invention affixed to an end user circuit board in an alternate fashion; FIG. 6 is a plan view of a substrate to which a silicon condenser microphone is fixed; FIG. 7 is a longitudinal cross-sectional view of a microphone package of the present invention; FIG. 8 is a lateral cross-sectional view of a microphone package of the present invention; FIG. 9 is a longitudinal cross-sectional view of a microphone package of the present invention; FIG. 10 is a lateral cross-sectional view of a microphone package of the present invention; FIG. 11 is a cross-sectional view of a top portion for a microphone package of the present invention; FIG. 12 is a cross-sectional view of a top portion for a microphone package of the present invention; FIG. 13 is a cross-sectional view of a top portion for a microphone package of the present invention; FIG. 14 a is a cross-sectional view of a laminated bottom portion of a housing for a microphone package of the present invention; FIG. 14 b is a plan view of a layer of the laminated bottom portion of FIG. 14 a; FIG. 14 c is a plan view of a layer of the laminated bottom portion of FIG. 14 a; FIG. 14 d is a plan view of a layer of the laminated bottom portion of FIG. 14 a; FIG. 15 is a cross-sectional view of a bottom portion for a microphone package of the present invention; FIG. 16 is a cross-sectional view of a bottom portion for a microphone package of the present invention; FIG. 17 is a cross-sectional view of a bottom portion for a microphone package of the present invention; FIG. 18 is a cross-sectional view of a bottom portion for a microphone package of the present invention; FIG. 19 is a plan view of a side portion for a microphone package of the present invention; FIG. 20 is a cross-sectional view of a side portion for a microphone package of the present invention; FIG. 21 is a cross-sectional view of a side portion for a microphone package of the present invention; FIG. 22 is a cross-sectional view of a side portion for a microphone package of the present invention; FIG. 23 is a cross-sectional view of a microphone package of the present invention; FIG. 24 is a cross-sectional view of a microphone package of the present invention; FIG. 25 is a cross-sectional view of a microphone package of the present invention; FIG. 26 is a cross-sectional view of a microphone package of the present invention; FIG. 27 is a cross-sectional view of a microphone package of the present invention with a retaining ring; FIG. 28 is a cross-sectional view of a microphone package of the present invention with a retaining wing; FIG. 29 is a cross-sectional view of a microphone package of the present invention with a retaining ring; FIG. 30 is a plan view of a panel of a plurality of microphone packages; and FIG. 31 is a plan view of a microphone pair. DETAILED DESCRIPTION While the invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail several possible embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. The present invention is directed to microphone packages. The benefits of the microphone packages disclosed herein over microphone packaging utilizing plastic body/lead frames include the ability to process packages in panel form allowing more units to be formed per operation and at much lower cost. The typical lead frame for a similarly functioning package would contain between 40 and 100 devices connected together. The present disclosure would have approximately 14,000 devices connected together (as a panel). Also, the embodiments disclosed herein require minimal “hard-tooling” This allows the process to adjust to custom layout requirements without having to redesign mold, lead frame, and trim/form tooling. Moreover, many of the described embodiments have a better match of thermal coefficients of expansion with the end user's PCB, typically made of FR-4, since the microphone package is also made primarily of FR-4. These embodiments of the invention may also eliminate the need for wire bonding that is required in plastic body/lead frame packages. The footprint is typically smaller than that would be required for a plastic body/lead frame design since the leads may be formed by plating a through-hole in a circuit board to form the pathway to the solder pad. In a typical plastic body/lead frame design, a (gull wing configuration would be used in which the leads widen the overall foot print. Now, referring to FIGS. 1-3 , three embodiments of a silicon condenser microphone package 10 of the present invention are illustrated. Included within silicon microphone package 10 is a transducer 12 , e.g. a silicon condenser microphone as disclosed in U.S. Pat. No. 5,870,482 which is hereby incorporated by reference and an amplifier 16 . The package itself includes a substrate 14 , a back volume or air cavity 18 , which provides a pressure reference for the transducer 12 , and a cover 20 . The substrate 14 may be formed of FR-4 material allowing processing in circuit board panel form, thus taking advantage of economies of scale in manufacturing. FIG. 6 is a plan view of the substrate 14 showing the back volume 18 surrounded a plurality of terminal pads. The back volume 18 may be formed by a number of methods, including controlled depth drilling of an upper surface 19 of the substrate 14 to form a recess over which the transducer 12 is mounted ( FIG. 1 ); drilling and routing of several individual sheets of FR-4 and laminating the individual sheets to form the back volume 18 , which may or may not have internal support posts ( FIG. 2 ); or drilling completely through the substrate 14 and providing a sealing ring 22 on the bottom of the device that will seal the back volume 18 during surface mounting to a user's “board” 28 ( FIGS. 3-5 ). In this example, the combination of the substrate and the user's board 28 creates the back volume 18 . The back volume 18 is covered by the transducer 12 (e.g., a MEMS device) which may be “bumpbonded” and mounted face down. The boundary is sealed such that the back volume 18 is operably “air-tight.” The cover 20 is attached for protection and processability. The cover 20 contains an aperture 24 which may contain a sintered metal insert 26 to prevent water, particles and/or light from entering the package and damaging the internal components inside; i.e. semiconductor chips. The aperture 24 is adapted for allowing sound waves to reach the transducer 12 . The sintered metal insert 26 will also have certain acoustic properties, e.g. acoustic damping or resistance. The sintered metal insert 26 may therefore be selected such that its acoustic properties enhance the functional capability of the transducer 12 and/or the overall performance of the silicon microphone 10 . Referring to FIGS. 4 and 5 the final form of the product is a silicon condenser microphone package 10 which would most likely be attached to an end user's PCB 28 via a solder reflow process. FIG. 5 illustrates a method of enlarging the back volume 18 by including a chamber 32 within the end user's circuit board 28 . Another embodiment of a silicon condenser microphone package 40 of the present invention is illustrated in FIGS. 7-10 . In this embodiment, a housing 42 is formed from layers of materials, such as those used in providing circuit boards. Accordingly, the housing 42 generally comprises alternating layers of conductive and non-conductive materials 44 , 46 . The non-conductive layers 46 are typically FR-4 board. The conductive layers 44 are typically copper. This multi-layer housing construction advantageously permits the inclusion of circuitry, power and ground planes, solder pads, ground pads, capacitance layers and plated through holes pads within the structure of the housing itself. The conductive layers provide EMI shielding while also allowing configuration as capacitors and/or inductors to filter input/output signals and/or the input power supply. In the embodiment illustrated, the housing 42 includes a top portion 48 and a bottom portion 50 spaced by a side portion 52 . The housing 42 further includes an aperture or acoustic port 54 for receiving an acoustic signal and an inner chamber 56 which is adapted for housing a transducer unit 58 , typically a silicon die microphone or a ball grid array package (BGA). The top, bottom, and side portions 48 , 50 , 52 are electrically connected, for example with a conductive adhesive 60 . The conductive adhesive may be provided conveniently in the form of suitably configured sheets of dry adhesive disposed between the top, bottom and side portions 48 , 50 and 52 . The sheet of dry adhesive may be activated by pressure, heat or other suitable means after the portions are brought together during assembly. Each portion may comprise alternating conductive and non-conductive layers of 44 , 46 . The chamber 56 may include an inner lining 61 . The inner lining 61 is primarily formed by conductive material. It should be understood that the inner lining may include portions of non-conductive material, as the conductive material may not fully cover the non-conductive material. The inner lining 61 protects the transducer 58 against electromagnetic interference and the like, much like a faraday cage. The inner lining 61 may also be provided by suitable electrically coupling together of the various conductive layers within the top, bottom and side portions 48 , 50 and 52 of the housing. In the various embodiments illustrated in FIGS. 7-10 and 23 - 26 , the portions of the housing 42 that include the aperture or acoustic port 54 further include a layer of material that forms an environmental barrier 62 over or within the aperture 54 . This environmental barrier 62 is typically a polymeric material formed to a film, such as a polytetrafluoroethylene (PTFE) or a sintered metal. The environmental barrier 62 is supplied for protecting the chamber 56 of the housing 42 , and, consequently, the transducer unit 58 within the housing 42 , from environmental elements such as sunlight, moisture, oil, dirt, and/or dust. The environmental barrier 62 will also have inherent acoustic properties, e.g. acoustic damping/resistance. Therefore the environmental barrier 62 is chosen such that its acoustic properties cooperate with the transducer unit 58 to enhance the performance of the microphone. This is particularly true in connection with the embodiments illustrated in FIGS. 24 and 25 , which may be configured to operate as directional microphones. The environmental barrier layer 62 is generally sealed between layers of the portion, top 48 or bottom 50 in which the acoustic port 54 is formed. For example, the environmental barrier may be secured between layers of conductive material 44 thereby permitting the layers of conductive material 44 to act as a capacitor (with electrodes defined by the metal) that can be used to filter input and output signals or the input power. The environmental barrier layer 62 may further serve as a dielectric protective layer when in contact with the conductive layers 44 in the event that the conductive layers also contain thin film passive devices such as resistors and capacitors. In addition to protecting the chamber 56 from environmental elements, the barrier layer 62 allows subsequent wet processing, board washing of the external portions of the housing 42 , and electrical connection to ground from the walls via thru hole plating. The environmental barrier layer 62 also allows the order of manufacturing steps in the fabrication of the printed circuit board-based package to be modified. This advantage can be used to accommodate different termination styles. For example, a double sided package can be fabricated having a pair of apertures 54 (see FIG. 25 ), both including an environmental barrier layer 62 . The package would look and act the same whether it is mounted face up or face down, or the package could be mounted to provide directional microphone characteristics. Moreover, the environmental barrier layer 62 may also be selected so that its acoustic properties enhance the directional performance of the microphone. Referring to FIGS. 7 , 8 , and 11 - 13 the transducer unit 58 is generally not mounted to the top portion 48 of the housing. This definition is independent of the final mounting orientation to an end user's circuit board. It is possible for the top portion 48 to be mounted face down depending on the orientation of the transducer 58 as well as the choice for the bottom portion 50 . The conductive layers 44 of the top portion 48 may be patterned to form circuitry, ground planes, solder pads, ground pads, capacitors and plated through hole pads. Referring to FIGS. 1-13 there may be additional alternating conductive layers 44 , non-conductive layers 46 , and environmental protective membranes 62 as the package requires. Alternatively, some layers may be deliberately excluded as well. The first non-conductive layer 46 may be patterned so as to selectively expose certain features on the first conductive layer 44 . FIG. 11 illustrates an alternative top portion 48 for a microphone package. In this embodiment, a connection between the layers can be formed to provide a conduit to ground. The top portion of FIG. 11 includes ground planes and/or pattern circuitry 64 and the environmental barrier 62 . The ground planes and or pattern circuitry 64 are connected by pins 65 . FIG. 12 illustrates another embodiment of a top portion 48 . In addition to the connection between layers, ground planes/pattern circuitry 64 , and the environmental barrier 62 , this embodiment includes conductive bumps 66 (e.g. Pb/Sn or Ni/Au) patterned on the bottom side to allow secondary electrical contact to the transducer 58 . Here, conductive circuitry would be patterned such that electrical connection between the bumps 66 and a plated through hole termination is made. FIG. 13 illustrates yet another embodiment of the top portion 48 . In this embodiment, the top portion 48 does not include an aperture or acoustic port 54 . Referring to FIGS. 7 , 8 and 14 - 18 , the bottom portion 50 is the component of the package to which the transducer 58 is primarily mounted. This definition is independent of the final mounting orientation to the end user's circuit board. It is possible for the bottom portion 50 to be mounted facing upwardly depending on the mounting orientation of the transducer 58 as well as the choice for the top portion 48 construction. Like the top portion 48 , the conductive layers 44 of the bottom portion 50 may be patterned to form circuitry, ground planes, solder pads, ground pads, capacitors and plated through hole pads. As shown in FIGS. 14-18 , there may be additional alternating conductive layers 44 , non-conductive layers 46 , and environmental protective membranes 62 as the package requires. Alternatively, some layers may be deliberately excluded as well. The first non-conductive layer 46 may be patterned so as to selectively expose certain features on the first conductive layer 44 . Referring to FIGS. 14 a through 14 d , the bottom portion 50 comprises a laminated, multi-layered board including layers of conductive material 44 deposited on layers of non-conductive material 46 . Referring to FIG. 14 b , the first layer of conductive material is used to attach wire bonds or flip chip bonds. This layer includes etched portions to define lead pads, bond pads, and ground pads. The pads would have holes drilled through them to allow the formation of plated through-holes. As shown in FIG. 14 c , a dry film 68 of non-conductive material covers the conductive material. This illustration shows the exposed bonding pads as well as an exposed ground pad. The exposed ground pad would come in electrical contact with the conductive epoxy and form the connection to ground of the side portion 52 and the base portion 50 . Referring to FIG. 14 d , ground layers can be embedded within the base portion 50 . The hatched area represents a typical ground plane 64 . The ground planes do not overlap the power or output pads, but will overlap the transducer 58 . Referring to FIG. 15 , an embodiment of the bottom portion 50 is illustrated. The bottom portion 50 of this embodiment includes a solder mask layer 68 and alternating layers of conductive and non-conductive material 44 , 46 . The bottom portion further comprises solder pads 70 for electrical connection to an end user's board. FIGS. 16 and 17 illustrate embodiments of the bottom portion 50 with enlarged back volumes 18 . These embodiments illustrate formation of the back volume 18 using the conductive/non-conductive layering. FIG. 18 shows yet another embodiment of the bottom portion 50 . In this embodiment, the back portion 50 includes the acoustic port 54 and the environmental barrier 62 . Referring to FIGS. 7-10 and 19 - 22 , the side portion 52 is the component of the package that joins the bottom portion 50 and the top portion 48 . The side portion 52 may include a single layer of a non-conductive material 46 sandwiched between two layers of conductive material 44 . The side portion 52 forms the internal height of the chamber 56 that houses the transducer 58 . The side portion 52 is generally formed by one or more layers of circuit board material, each having a routed window 72 (see FIG. 19 ). Referring to FIGS. 19-22 , the side portion 52 includes inner sidewalls 74 . The inner sidewalls 74 are generally plated with a conductive material, typically copper, as shown in FIGS. 20 and 21 . The sidewalls 74 are formed by the outer perimeter of the routed window 72 and coated/metallized with a conductive material. Alternatively, the sidewalls 74 may be formed by may alternating layers of non-conductive material 46 and conductive material 44 , each having a routed window 72 (see FIG. 19 ). In this case, the outer perimeter of the window 72 may not require coverage with a conductive material because the layers of conductive material 44 would provide effective shielding. FIGS. 23-26 illustrate various embodiments of the microphone package 40 . These embodiments utilize top, bottom, and side portions 48 , 50 , and 52 which are described above. It is contemplated that each of the top, bottom, and side portion 48 , 50 , 52 embodiments described above can be utilized in any combination without departing from the invention disclosed and described herein. In FIG. 23 , connection to an end user's board is made through the bottom portion 50 . The package mounting orientation is bottom portion 50 down. Connection from the transducer 58 to the plated through holes is be made by wire bonding. The transducer back volume 18 is formed by the back hole (mounted down) of the silicon microphone only. Bond pads, wire bonds and traces to the terminals are not shown. A person of ordinary skilled in the art of PCB design will understand that the traces reside on the first conductor layer 44 . The wire bonds from the transducer 58 are be connected to exposed pads. The pads are connected to the solder pads via plated through holes and traces on the surface. In FIG. 24 , connection to the end user's board is also made through the bottom portion 50 . Again, the package mounting orientation is bottom portion 50 . Connection from the transducer 58 to the plated through holes are made by wire bonding. The back volume is formed by a combination of the back hole of the transducer 58 (mounted down) and the bottom portion 50 . In FIG. 25 , connection to the end user's board is also made through the bottom portion 50 . Again, the package mounting orientation is bottom portion 50 . Connection from the transducer 58 to the plated through holes are made by wire bonding. With acoustic ports 54 on both sides of the package, there is no back volume. This method is suitable to a directional microphone. In FIG. 26 , connection to the end user's board is made through the top portion 48 or the bottom portion 53 . The package mounting orientation is either top portion 48 down or bottom portion 50 down. Connection from the transducer 58 to the plated through holes is made by flip chipping or wire bonding and trace routing. The back volume 18 is formed by using the air cavity created by laminating the bottom portion 50 and the top portion 48 together. Some portion of the package fabrication is performed after the transducer 58 has been attached. In particular, the through hole formation, plating, and solder pad definition would be done after the transducer 58 is attached. The protective membrane 62 is hydrophobic and prevents corrosive plating chemistry from entering the chamber 56 . Referring to FIGS. 27-29 , the portion to which the transducer unit 58 is mounted may include a retaining ring 84 . The retaining ring 84 prevents wicking of an epoxy 86 into the transducer 58 and from flowing into the acoustic port or aperture 54 . Accordingly, the shape of the retaining ring 84 will typically match the shape of the transducer 58 foot print. The retaining ring 84 comprises a conductive material (e.g., 3 mil. thick copper) imaged on a non-conductive layer material. Referring to FIG. 27 , the retaining ring 84 is imaged onto a nonconductive layer. An epoxy is applied outside the perimeter of the retaining ring 84 , and the transducer 58 is added so that it overlaps the epoxy 86 and the retaining ring 84 . This reduces epoxy 86 wicking up the sides of the transducer's 58 etched port (in the case of a silicon die microphone). Alternatively, referring to FIG. 28 , the retaining ring 84 can be located so that the transducer 58 does not contact the retaining ring 84 . In this embodiment, the retaining ring 84 is slightly smaller than the foot print of the transducer 58 so that the epoxy 86 has a restricted path and is, thus, less likely to wick. In FIG. 29 , the retaining ring 84 is fabricated so that it contacts the etched port of the transducer 58 . The following tables provide an illustrative example of a typical circuit board processing technique for fabrication of the housing of this embodiment. TABLE 1 Materials Material Type Component Note 1 0.5/0.5 oz. DST Bottom Portion Cu 5 core FR-4 (Conductive Layers Non- Conductive Layer 1) 2 0.5/0.5 oz. DST Bottom Portion (Conductive Cu 5 core FR-4 Layers 3 and 4; Non- Conductive Layer 2) 3 106 pre-preg For Laminating Material 1 and Material 2 4 0.5/0.5 oz. DST Side Portion Metallized Cu 40 Core FR-4 Afterward 5 Bare/0.5 oz. Cu 2 Top Portion (Each Piece core FR-4 (2 Includes 1 Conductive and 1 pieces) Non-Conductive Layer) 6 Expanded PTFE Environmental Barrier TABLE 2 Processing of Materials (Base Portion Material 1) Step Type Description Note 1 Dry Film Conductive Layers 2 Expose Mask Material 1 (Upper Forms Ground Conductive Layer) Plane on Lower Conductive Layer 3 Develop 4 Etch Cu No Etching on Upper Conductive Layer 5 Strip Dry Film TABLE 3 Processing of Materials (Bottom Portion Material 2) Step Type Description Note 1 Dry Film Conductive Layers 2 Expose Mask Material 2 (Upper Forms Ground Conductive Layer) Plane on Upper Conductive Layer 3 Develop 4 Etch Cu No Etching on Upper Conductive Layer 5 Strip Dry Film TABLE 4 Processing of Materials 1, 2, and 3 (Form Bottom Portion) Step Type Description Note 1 Laminate Materials 1 and 2 Laminated Using Material 3 2 Drill Thru Holes Drill Bit = 0.025 in. 3 Direct Plates Thru Holes Metallization/Flash Copper 4 Dry Film (L1 and L4) 5 Expose Mask Laminated Forms Traces and Materials 1 and 2 Solder Pads (Upper and Lower Conductive Layers) 6 Develop 7 Electrolytic Cu 1.0 mil 8 Electrolytic Sn As Required 9 Strip Dry Film 10 Etch Cu 11 Etch Cu 12 Insert Finishing NG Option (See NG Option for Proof Option Here Table Below) of Principle 13 Dry Film (cover 2.5 mil Minimum Thickness lay) on Upper on Upper Conductive Conductive Layer Layer Only 14 Expose Mask Laminated This mask defines an Materials 1 and 2 area on the upper (upper and lower) conductive layer that will receive a dry film solder mask (cover lay). The bottom layer will not have dry film applied to it. The plated through holes will be bridged over by the coating on the top. 15 Develop 16 Cure Full Cure 17 Route Panels Route Bit = As Forms 4″ × 4″ pieces. Required Conforms to finished dims Table 5 describes the formation of the side portion 52 . This process involves routing a matrix of openings in FR-4 board. However, punching is thought to be the cost effective method for manufacturing. The punching may done by punching through the entire core, or, alternatively, punching several layers of no-flow pre-preg and thin core c-stage which are then laminated to form the wall of proper thickness. After routing the matrix, the board will have to be electroless or DM plated. Finally, the boards will have to be routed to match the bottom portion. This step can be done first or last. It may make the piece more workable to perform the final routing as a first step. TABLE 5 Processing of Material 4 (Side Portion) Step Type Description Note 1 Route/Punch Route Bit = 0.031 in. Forms Side Portion Matrix of Openings 2 Direct 0.25 mil minimum Forms Sidewalls Metallization/ on Side Portion Flash Cu 3 Route Panels Table 6 describes the processing of the top portion. The formation of the top portion 48 involves imaging a dry film cover lay or liquid solder mask on the bottom (i.e. conductive layer forming the inner layer. The exposed layer of the top portion 48 will not have a copper coating. It can be processed this way through etching or purchased this way as a one sided laminate. A matrix of holes is drilled into the lid board. Drilling may occur after the imaging step. If so, then a suitable solder mask must be chosen that can survive the drilling process. TABLE 6 Processing of Top Portion Step Type Description Note 1 Dry Film Conductive Layer 2 Expose Mask Bare Layer Form Conduction Ring 3 Develop 4 Cure 5 Drill Matrix of Drill Bit 0.025 in. Acoustic Ports Holes 6 Laminate PTFE (Environmental Forms Top Portion Barrier) Between 2 Pieces of Material 5 TABLE 7 Processing of Laminated Materials 1 and 2 with Material 4 Step Type Description Note 1 Screen Conductive Adhesive on Material 4 2 Laminate Bottom Portion with Side Forms Bottom Portion Portion with Side Portion (spacer) 3 Add Transducer Silicon Die Microphone Assembly and Integrated Circuit TABLE 8 Processing of Laminated Materials 1, 2, and 4 with Material 5 Step Type Description Note 1 Screen Conductive Adhesive on Top Portion 2 Laminate Bottom Portion and Side Forms Housing Portion with Top Portion 3 Dice TABLE 9 Finishing Option NG (Nickel/Gold) Step Type Description Note 1 Immersion Ni (40-50 μ-in) 2 Immersion Au (25-30 μ-in) TABLE 10 Finishing Option NGT (Nickel/Gold/Tin) Step Type 1 Mask L2 (using thick dry film or high tack dicing tape) 2 Immersion Ni (40-50 μ-in) 3 Immersion Au (25-30 μ-in) 4 Remove Mask on L2 5 Mask L1 (using thick dry film or high tack dicing tape) bridge over cavity created by wall 6 Immersion Sn (100-250 μ-in) 7 Remove Mask on L1 TABLE 11 Finishing Option ST (Silver/Tin) Step Type 1 Mask L2 (using thick dry film or high tack dicing tape) 2 Immersion Ag (40-50 μ-in) 3 Remove Mask on L2 4 Mask L1 (using thick dry film or high tack dicing tape) bridge over cavity created by wall 5 Immersion Sn (100-250 μ-in) 6 Remove Mask on L1 FIG. 30 is a plan view illustrating a panel 90 for forming a plurality of microphone packages 92 . The microphone packages 92 are distributed on the panel 90 in a 14×24 array, or 336 microphone packages total. Fewer or more microphone packages may be disposed on the panel 90 , or on smaller or larger panels. As described herein in connection with the various embodiments of the invention, the microphone packages include a number of layers, such as top, bottom and side portions of the housing, environmental barriers, adhesive layers for joining the portions, and the like. To assure alignment of the portions as they are brought together, each portion may be formed to include a plurality of alignment apertures 94 . To simultaneously manufacture several hundred or even several thousand microphones, a bottom layer, such as described herein, is provided. A transducer, amplifier and components are secured at appropriate locations on the bottom layer corresponding to each of the microphones to be manufactured. An adhesive layer, such as a sheet of dry adhesive is positioned over the bottom layer, and a sidewall portion layer is positioned over the adhesive layer. An additional dry adhesive layer is positioned, followed by an environmental barrier layer, another dry adhesive layer and the top layer. The dry adhesive layers are activated, such as by the application of heat and/or pressure. The panel is then separated into individual microphone assemblies using known panel cutting and separating techniques. The microphone, microphone package and method of assembly herein described further allow the manufacture of multiple microphone assembly, such as microphone pairs. In the simplest form, during separation two microphones may be left joined together, such as the microphone pair 96 shown in FIG. 31 . Each microphone 98 and 100 of the microphone pair 96 is thus a separate, individually operable microphone in a single package sharing a common sidewall 102 . Alternatively, as described herein, conductive traces may be formed in the various layers of either the top or bottom portion thus allowing multiple microphones to be electrically coupled. While specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying Claims.

The present invention relates to a surface mount package for a micro-electro-mechanical system (MEMS) microphone die and methods for manufacturing the surface mount package. The surface mount package uses a limited number of components that simplifies manufacturing and lowers costs. The surface mount package features a substrate that performs functions for which multiple components were traditionally required, including providing an interior surface on which the MEMS microphone die is mechanically attached, providing an interior surface for making electrical connections between the MEMS microphone die and the package, and providing an exterior surface for surface mounting the microphone package to a device's printed circuit board and for making electrical connections between the microphone package and the device's circuit board. The microphone package has a substrate with metal pads on its top and bottom surfaces, a sidewall spacer, and a lid. A MEMS microphone die is mounted on the substrate, and the substrate, the sidewall spacer, and the lid are joined together to form the MEMS microphone.

RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 10/732,438,filed Dec. 10, 2003 (now U.S. Pat. No. 7,314,868), which is a continuation of U.S. patent application Ser. No. 09/070,630, filed Apr. 30, 1998 (now U.S. Pat. No. 6,750,206, which is a continuation of International Patent Application No. PCT/GB98/00710, filed Mar. 10, 1998, which claims benefit of U.S. Provisional Patent Application Ser. No. 60/045,164, filed Apr. 30, 1997 and U.K. Patent Application Serial No. 9705007.4, filed Mar. 11, 1997. This application claims benefit to U.S. patent application Ser. No. 10,732,438,filed Dec. 10, 2003 (now U.S. Pat. No. 7,314,868), U.S. patent application Ser. No. 09/070,630, filed Apr. 30, 1998, International Patent Application No. PCT/GB98/00710, filed Mar. 10, 1998, U.S. Provisional Patent Application Ser. No. 60/045,164, filed Apr. 30, 1997, and U.K. Patent Application Serial No. 9705007.4, filed Mar. 11, 1997. FIELD OF THE INVENTION This invention relates to genes encoding fusogenic viral membrane glycoproteins and cells expressing such genes. BACKGROUND OF THE INVENTION Prior art methods of treating cell proliferative disorders such as cancer have involved introduction into a patient of genes or vehicles containing genes encoding, for example, proteins that enhance the immunogenicity of tumor cells. These include pro-inflammatory cytokines, T cell co-stimulators and foreign MHC proteins which produce a local bystander effect due to local inflammatory response. The local inflammatory response is said to create a cytokine-rich environment which favors the generation of a systemic bystander effect by recruitment and activation of tumor-specific T cells. Alternatively, it has been suggested to deliver to a tumor genes encoding enzymes that render tumor cells susceptible to a “pro-drug”. For thymidine kinase gene transfer, there is some evidence for a local bystander effect due to transfer of ganciclovir triphosphate (the activated drug) through tight junctions to adjacent tumor cells. However, many tumors lack the requisite tight junctions and the observed local and systemic bystander effects are therefore presumed to arise because of a local inflammatory response to cells that are killed by the pro-drug with associated activation of tumor-reactive T cells. Replicating viruses have been used extensively as oncolytic agents for experimental cancer therapy (Russell, 1994, Semin. Cancer Biol. 5, 437-443). For example, a tissue culture suspension of mumps virus was used to treat 90 patients with terminal malignancies by local application to the tumor surface, by intratumoral, oral, rectal or intravenous inoculation, or by inhalation (Asada, 1974, Cancer, 34, 1907-1928). Toxicity was minimal and in 37 of the 90 patients the tumor disappeared or decreased to less than half of its initial size. Minor responses were observed in a further 42 patients. Tumor destruction was maximal several days after virus administration and was often followed by long-term suppression of tumor growth, perhaps due to stimulation of antitumor immunity. Other viruses that have been used for cancer therapy in human subjects or experimental mouse models include West Nile virus, herpes simplex virus, Russian Far East encephalitis, Newcastle disease virus, Venezuelan equine encephalomyelitis, rabies, vaccinia and varicella (Russell, 1994, Eur. J. Cancer, 30A, 1165-1171). The rationale for these studies has been that many viruses replicate and spread more rapidly in neoplastic tissues than in nontransformed tissues and might therefore be expected to cause more damage to the tumor than to the host. It is an object of the invention to provide compositions and methods for selective elimination of unwanted cells. Another object of the invention is to selectively eliminate target cells by achieving a bystander effect. Another object of the invention is to selectively induce syncytium formation of target cells, thereby eliminating the target cells. SUMMARY OF THE INVENTION The invention encompasses compositions comprising pharmaceutical formulations comprising a recombinant nucleic acid vector comprising a nucleotide sequence encoding a syncytium-inducing polypeptide expressible on a eukaryotic cell surface in admixture with a pharmaceutically acceptable carrier. The invention also encompasses compositions comprising pharmaceutical formulations comprising a eukaryotic host cell containing a recombinant nucleic acid vector comprising a nucleotide sequence encoding a syncytium-inducing polypeptide and expressing the polypeptide on its surface, in admixture with a pharmaceutically acceptable carrier. Preferably, in a composition according to the invention the sequence encodes at least a fusogenic portion of a viral fusogenic membrane glycoprotein. Preferably, the sequence encodes a non-naturally occurring polypeptide. “Non-naturally occurring polypeptide refers to a recombinant polypeptide; for example, a chimeric polypeptide. Preferably, the sequence encodes a fusogenic membrane glycoprotein having an artificially introduced protease-cleavage site. Preferably, the sequence encodes a fusogenic membrane glycoprotein having an altered binding specificity. Preferably, the sequence encodes a fusogenic membrane glycoprotein having enhanced fusogenicity, for example, as results from truncation of the carboxy terminal portion of a fusogenic membrane glycoprotein. The eukaryotic host cell may be a human cell, such as a host cell selected from the group consisting of: neoplastic cells, migratory cells, T lymohocytes, B lymphocytes or other haemopoietic cells. The invention also features a method of eliminating unwanted cells of a cell proliferative disease in a human patient, comprising administering to the patient a pharmaceutical formulation according to the invention in an amount sufficient to cause fusion of those cells which cause the cell proliferative disease. The invention also encompasses kits comprising a pharmaceutical formulation described herein, and packaging means therefore. Nucleic acid vectors and host cells of the invention are useful in gene therapy of diseases involving cell proliferative disorders, where it is desired that cells which proliferate undesirably or uncontrollably are selectively eliminated. Such diseases include but are not limited to malignant diseases. The vector encoding the syncytium-inducing polypeptide or a host cell expressing on its surface a syncytium-inducing polypeptide is administered to an affected individual so as to cause cell-cell fusion of unwanted cells. Preferably, the syncytium-inducing polypeptide comprises at least a fusogenic portion of a viral fusogenic membrane glycoprotein (which may be abbreviated as FMG). In some embodiments, it is preferred that the syncytium-inducing polypeptide is capable of inducing syncytium formation at substantially neutral pH (i.e. pH 6-8). Many suitable FMGs will be known to those skilled in the art and several are provided hereinbelow. Typically the vector will be adapted so as to express the syncytium-inducing polypeptide on the surface of a human cell, such that, when properly expressed, the polypeptide may cause the cell to fuse with other human cells which do not express the syncytium-inducing polypeptide. It is preferred that, where the polypeptide comprises a viral FMG, the FMG is expressed in substantial isolation from other viral components and thus consists essentially of those viral components which are essential for fusogenic activity on target cells (e.g. where two viral glycoproteins are required for syncytium formation, such as the ‘F’ and ‘H’ glycoproteins of Paramyxoviridae both being required for syncytium-formation). In addition, it will frequently be desirable to “engineer” the syncytium-inducing polypeptide to optimize its characteristics for therapeutic use, such that the vector directs the expression of a “non-naturally occurring” polypeptide. Preferred modifications include truncation of the cytoplasmic domain of a glycoprotein so as to increase its fusiongenic activity; introduction of novel binding specificities or protease-dependencies into fusogenic viral membrane glycoproteins and thereby to target their fusogenic activities to specific cell types that express the targeted receptors or to specific microenvironments that are rich in the appropriate activating proteases. The invention provides a method of treating a cell proliferative disease such as a malignant disease in a human patient, comprising administering to the patient a recombinant nucleic acid directing the expression of a syncytium inducing polypeptide in a human cell, such that cells (“index” cells) of the patient which take up the recombinant nucleic acid will fuse with the proliferating cells, e.g., cancerous cells (“target” cells) causing the disease. In a particular embodiment, the nucleic acid is introduced in vitro into suitable human index cells (by any one of various known standard techniques, such as transfection, transduction or transformation), and the index cells are then introduced into the patient, where they can exert a syncytium-inducing effect on target cells. The invention also provides for use of a recombinant nucleic acid vector in the gene therapy of a cell proliferative disorder such as a malignant disease, the vector comprising a sequence directing the expression on a eukaryotic cell surface of a syncytium-inducing polypeptide. The invention also provides a recombinant nucleic acid vector for use in the preparation of a medicament to treat a cell proliferative disease such as a malignant disease in a human patient, the vector comprising a sequence directing the expression on a eukaryotic cell surface of a syncytium-inducing polypeptide. The invention also provides a host cell comprising a recombinant nucleic acid vector in accordance with the invention defined above. The cell will typically be a eukaryotic cell (especially a human cell) and desirably will express on its surface a syncytium-inducing polypeptide. As used herein, the term “syncytium inducing polypeptide” refers to a polypeptide or a portion thereof that induces cell-cell fusion resulting in formation of a syncytium. The term “syncytium” refers to a cell-cell fusion which appears in a tissue biopsy or tissue culture sample as a large acellular area with multiple nucleii, i.e., a multinucleate region of cytoplasm. “Enhanced induction of syncytium formation” refers to the biological activity of a syncytium inducing polypeptide in which the enhancement is an increase in the number of cells that are induced to form a syncytium above (at least 10-20%) the level of that observed without the syncytium inducing polypeptide or, if the syncytium inducing polypeptide is engineered to achieve the enhanced activity, then above the level of that observed using the non-engineered polypeptide. “Enhanced fusogenic activity” is also used herein to refer to enhanced syncytium inducing activity. “Nonviable syncytium” refers to syncytium that do not survive for longer than 48-72 hours in tissue culture (i.e., in vitro), or a syncytium which is immunogenic (recognized by the immune system) in vivo and are nonviable in an immunocompetent host. As used herein, the term “substantial isolation” of a viral polypeptide or gene encoding a viral polypeptide, with respect to other viral components, means that most of the other components of the virus (those not necessary for fusogenic activity of the virus polypeptide) are absent, and thus the DNA or viral polypeptide consists essentially of those viral components which are essential for fusogenic activity on target cells. A “fusogenic effect” refers to the natural biological activity of a fusogenic polypeptide in inducing cell fusions via the presence of a virus encoding and expressing the fusogenic polypeptide. Virus-cell fusion and cell-cell fusion are distinct processes. “Fusogenic” refers to the biological activity of a viral membrane glycoprotein to promote virus-cell fusion when in its natural virus context. In contrast, “syncytium-induction” refers to the biological activity of a syncytium-inducin polypeptide, which may be a viral membrane glycoprotein substantially isolated from its natural virus context, to induce cell-cell fusion without the virus. To be useful according to the invention, a viral glycoprotein which has a fusogenic effect when carried in the virus must be capable of inducing syncytium formation when in substantial isolation from the virus. A “fusogenic portion” refers to a portion of a fusogenic virus membrane polypeptide which possesses fusogenic activity and thus promotes virus-cell fusion. “Altered receptor specificity” refers to a modification in a ligand such that the receptor recognized by the modified ligand is altered from a first receptor to a second receptor; that is, the unmodified ligand recognizes a first receptor and the modified ligand recognizes a second receptor. “Novel protease-dependency” of a polypeptide according to the invention refers to the presence of a new protease sensitive site that is susceptible to cleavage where a site of proteolysis is artificially introduced into a given protein, and the protein containing the new sensitivity is dependent for becoming biologically active upon a protease that specifically cleaves the protein at the site of proteolysis; without cleavage by the protease at the new protease sensitive site, the protease-dependent polypeptide will not become biologically active. A “vector system” refers to one vector or several vectors which together encode specified components. The invention will now be further described by way of illustrative example and with reference to the accompanying drawing, FIG. 1 , which is a schematic representation of a recombinant nucleic acid vector in accordance with the invention. DRAWINGS The invention will now be further described by way of illustrative example and with reference to the accompanying drawings in which: FIGS. 1-3 are schematic representations of recombinant nucleic acid vectors: in FIG. 2 CMV is the CMV promoter; in FIGS. 1 and 3 LTR is the long terminal repeat; in FIG. 3 phleo r is the phleomycin resistance gene; in FIGS. 2 and 3 the IEGR (SEQ ID NO:14) linker sequence is the protease cleavage signal for FXa protease and * denotes stop codons (pCG-H EGF R− and pFBH EGF R− are SEQ ID NO:8; pCG-H XEGF R− and pFBH XEGF R− are SEQ ID NO:9; pCG-H IGF and pFBH IGF are SEQ ID NO:10; pCG-H XIGF and pFBH XIGF are SEQ ID NO:11); FIG. 4 is an immunoblot of cell lysates prepared from TELCeB6 transfectants, pFBH, pFBH EGF R− , pFBH XEGF R− , pFBH IGF, pFBH XIGF and the control, untransfected TELCeB6, probed with an anti-MV H antiserum; FIG. 5 shows a magnified view showing large C170 syncytia in a cell-cell fusion assay after X-gal staining: chimeric MV H proteins show syncytia formation, although at a lower level to that of the unmodified H protein; FIG. 6 shows the DNA and amino acid sequence of a truncated hyperfusogenic GaLV envelope protein (SEQ ID NOS:12 and 13, respectively); and FIG. 7 is a schematic representation of further recombinant nucleic acid vectors: in FIG. 7 , the striped box is the FXa cleavage signal, the lightly shaded box is the mature (residues 43-653 only) GaLV envelope, and the heavily shaded box is residues 633-674 of the moloney MLV envelope, poly A is a polyadenylation signal, L is a leader sequence. DESCRIPTION OF PREFERRED EMBODIMENTS The invention finds its basis in the use of a syncytium-inducing polypeptide which, when expressed on the surface of a mammalian cell, is capable of causing that cell to fuse with neighboring cells that do not express the syncytium-inducing polypeptide, to form a nonviable syncytium and thereby to selectively eliminate unwanted cells. If desired, the syncytium-inducing polypeptide can be engineered for enhanced fusogenic activity, altered cell receptor specificity, or novel protease-dependency, as described herein. The ideal syncytium-inducing polypeptide useful according to the invention is a protein that has the following properties: 1. Gives rise to a local bystander effect: i.e., the protein will lead to cell death of not only the transduced tumor cell, but also its nontransduced neighbors. 2. Gives rise to a systemic bystander effect. Usually, this means that the treatment has the effect of enhancing the immune response against tumor antigens on distant tumor cells. 3. Provides selectivity. It is important that the treatment does not cause undue damage to normal (noncancerous) host tissues, especially the vital organs. Selectivity can be an intrinsic property of the protein and/or arise from its mode of action. Alternatively, or additionally, selectivity can be achieved by vector targeting to ensure that a therapeutic gene encoding the protein is not delivered to nontarget cells, or by the use of gene regulatory elements (promoters/enhancers/silencers/locus control sequences) that do not give rise to gene expression in nontarget cells. According to the invention, engineered/targeted fusogenic viral membrane glycoproteins satisfy all three criteria of local bystander effect, systemic bystander effect (by promoting a local inflammatory response which helps to amplify systemic immunity), and specificity. They have the capacity for generating a potent local bystander effect because they induce the fusion of gene-modified cells with surrounding nontransduced cells, resulting in the death of all the cells that have fused together. They can also be engineered to enhance their potential for triggering cell-cell fusion, and hence their therapeutic potency. Also, it is possible to engineer the specificity of the cell-cell fusion process by engineering the fusogenic proteins to ensure, for example, that circulating tumor cells that express the fusogenic proteins can fuse only with other tumor cells and do not therefore damage normal host tissues. Characteristics of viral FMGs which may be susceptible to improvement by protein engineering include: (1) pH at which fusion is mediated (as explained herein, many viral FMGs mediate fusion only at acid pH, whereas fusion at neutral pH may frequently be preferred); (2) activation of the fusion function upon exposure to certain proteases (this can lead to localized activation at the surface of, or in the vicinity of, tumor cells, many of which secrete or express tumor-associated proteases, as explained hereinbelow in the section entitled “Protease targets”—accordingly the FMG can be targeted to tumor cells); (3) modification of natural FMGs (e.g. amino acid substitutions, truncations or production of chimeric FMGS)—chimeric FMGs could comprise novel binding specificities to target the FMGs to particular cell surface markers, or combine other desirable characteristics from different proteins. Syncytium-inducing polypeptides useful according to the invention may be selected from the following viral membrane glycoproteins. Viral Membrane Glycoproteins Mediating Cell-cell Fusion The invention contemplates the use of a gene encoding a polypeptide for the selective induction of syncytium formation in target cells, and the selective elimination of these target cells via the induction of a syncytium. Syncytium-inducing polypeptides useful according to the invention include fusogenic membrane glycoproteins which include but are not limited to the following. 1) Membrane Glycoproteins of Enveloped Viruses. Enveloped viruses have membrane spike glycoproteins for attachment to mammalian cell surfaces and for subsequent triggering of membrane fusion, allowing for viral entry into the cell. In some viruses attachment and fusion triggering are mediated by a single viral membrane glycoprotein, but in other viruses these functions are provided by two or more separate glycoproteins. Sometimes (e.g. Myxoviridae, Togaviridae, Rhabdoviridae) the fusion triggering mechanism is activated only after the virus has entered into the target cell by endocytosis, at acid pH (i.e., below about pH 6.0). Examples of such membrane glycoproteins in Rhabdoviruses are the those of type G in rabies (Genbank Acc. No. U11736), Mokola (Genbank Acc. No. U17064) and vesicular stomatitis (Genbank Acc. Nos. M21417 and J04326) viruses, and in Togaviruses, Other viruses (e.g. Paramyxoviridae, Retroviridae, Herpesviridae, Coronaviridae) can fuse directly with the target cell membrane at substantially neutral pH (about 6.0-8.0) and have an associated tendency to trigger membrane fusion between infected target cells and neighboring noninfected cells. The visible outcome of this latter tendency for triggering of cell-cell fusion is the formation of cell syncytia containing up to 100 nuclei (also known as polykaryocytes or multinucleated giant cells). Syncytium-formation results in the death of the cells which make up the syncytium. Viral membrane proteins of these latter groups of viruses are of particular interest in the present invention. In addition to those proteins from Paramyxoviruses, Retroviruses and Herpesviruses discussed below, examples of Coronavirus membrane glycoprotein genes include those encoding the murine hepatitis virus JHM surface projection protein (Genbank Acc. Nos. X04797, D00093 and M34437), porcine respiratory coronavirus spike- and membrane glycoproteins (Genbank Acc. No. Z24675) avian infectious bronchitis spike glycoprotein (Genbank Acc. No. X64737) and its precursor (Genbank Acc. No. X02342) and bovine enteric coronavirus spike protein (Genbank Acc. No. D00731). 2) Viral Membrane Glycoproteins of The Paramyxoviridae Viruses. Viruses of the Family Paramyxoviridae have a strong tendency for syncytium induction which is dependent in most cases on the co-expression of two homo-oligomeric viral membrane glycoproteins, the fusion protein (F) and the viral attachment protein (H, HN or G). Co-expression of these paired membrane glycoproteins in cultured cell lines is required for syncytium induction although there are exceptions to this rule such as SV5 whose F protein alone is sufficient for syncytium induction. F proteins are synthesized initially as polyprotein precursors (F 0 ) which cannot trigger membrane fusion until they have undergone a cleavage activation. The activating protease cleaves the F 0 precursor into an extraviral F 1 domain and a membrane anchored F 2 domain which remain covalently associated through disulphide linkage. The activating protease is usually a serine protease and cleavage activation is usually mediated by an intracellular protease in the Golgi compartment during protein transport to the cell surface. Alternatively, where the cleavage signal is not recognized by a Golgi protease, the cleavage activation can be mediated after virus budding has occurred, by a secreted protease (e.g. trypsin or plasmin) in an extracellular location (Ward et al. Virology, 1995, 209, p 242-249; Paterson et al., J. Virol., 1989, 63, 1293-1301). Examples of Paramyxovirus F genes include those of Measles virus (Genbank Acc. Nos. X05597 or D00090), canine distemper virus (Genbank Acc. No. M21849), Newcastle disease virus (Genbank Acc. No. M21881), human parainfluenza virus 3 (Genbank Acc. Nos. X05303 and D00125), simian virus 41 (Genbank Acc. Nos. X64275 and S46730), Sendai virus (Genbank Acc. No. D11446) and human respiratory syncytial virus (Genbank Acc. No M11486, which also includes glycoprotein G). Also of interest of Measles virus hemagluttinin (Genbank Acc. No. M81895) and the hemagluttinin neuraminidase genes of simian virus 41 (Genbank Acc. Nos. X64275 or S46730), human parainfluenza virus type 3 (M17641) and Newcastle disease virus (Genbank Acc. No. J03911). 3) Membrane Glycoproteins of the Herpesvirus Family. Certain members of the Herpesvirdae family are renowned for their potent syncytium-inducing activity. Indeed, Varicella-Zoster Virus has no natural cell-free state in tissue culture and spreads almost exclusively by inducing cell fusion, forming large syncytia which eventually encompass the entire monolayer. gH is a strongly fusogenic glycoprotein which is highly conserved among the herpesvirus; two such proteins are gH of human herpesvirus 1 (Genbank Acc. No. X03896) and simian varicella virus (Genbank Acc. No. U25866). Maturation and membrane expression of gH are dependent on coexpression of the virally encoded chaperone protein gL (Duus et al., Virology, 1995, 210, 429-440). Although gH is not the only fusogenic membrane glycoprotein encoded in the herpesvirus genome (gB has also been shown to induce syncytium formation), it is required for the expression of virus infectivity (Forrester et al., J. Virol., 1992, 66, 341-348). Representative genes encoding gB are found in human (Genbank Acc. No. M14923), bovine (Genbank Acc. No. Z15044) and cercopithecine (Genbank Acc. No. U12388) herpesviruses. 4) Membrane Glycoproteins of Retroviruses. Retroviruses use a single homo-oligomeric membrane glycoprotein for attachment and fusion triggering. Each subunit in the oligomeric complex is synthesized as a polyprotein precursor which is proteolytically cleaved into membrane-anchored (TM) and extraviral (SU) components which remain associated through covalent or noncovalent interactions. Cleavage activation of the retroviral envelope precursor polypeptide is usually mediated by a Golgi protease during protein transport to the cell surface. There are inhibitory (R) peptides on the cytoplasmic tails of the TM subunits of the envelope glycoproteins of Friend murine leukemia virus (FMLV, EMBL accession number X02794) and Mason Pfizer monkey virus (WMV; Genbank Acc. No. M12349) which are cleaved by the virally encoded protease after virus budding has occurred. Cleavage of the R peptide is required to activate fully the fusogenic potential of these envelope glycoproteins and mutants lacking the R peptide show greatly enhanced activity in cell fusion assays (Rein et al, J. Virol ., 1994, 68, 1773-1781; Ragheb & Anderson, J. Virol., 1994, 68, 3220-3231;-Brody el al, J. Virol. 1994, 68, 4620-4627). 5) MLV Membrane Glycoproteins' with Altered Specificity. Naturally occurring MLV strains can also differ greatly in their propensity for syncytium induction in specific cell types or tissues. One MLV variant shows a strong tendency to induce the formation of endothelial cell syncytia in cerebral blood vessels, leading to intracerebral hemorrhages and neurologic disease. The altered behavior of this MLV variant can be reproduced by introducing a single point mutation in the env gene of a non-neurovirulent strain of Friend MLV, resulting in a tryptophan-to-glycine substitution at amino acid position 120 in the variable region of the SU glycoprotein (Park et al, J. Virol., 1994, 68, 7516-7524). 6) HIV Membrane Glycoproteins. HIV strains are also known to differ greatly in their ability to induce the formation of T cell syncytia and these differences are known to be determined in large part by variability between the envelope glycoproteins of different strains. Typical examples are provided by Genbank accessions L15085 (V1 and V2 regions) and U29433 (V3 region). 7) Acid-triggered Fusogenic Glycoproteins having an Altered pH Optimum. The membrane glycoproteins of viruses that normally trigger fusion at acid pH do not usually promote syncytium formation. However, they can trigger cell-cell fusion under certain circumstances. For example, syncytia have been observed when cells expressing influenza haemagglutinin (Genbank Acc. No. U44483) or the G protein of Vesicular Stomatitis Virus (Genbank Acc. Nos. M21417 and J04326) are exposed to acid (Steinhauer et al, Proc. Natl. Acad. Sci. USA 1996, 93, 12873-12878) or when the fusogenic glycoproteins are expressed at a very high density (Yang et al, Hum. Gene Ther. 1995, 6, 1203-1213). In addition, acid-triggered fusogenic viral membrane glycoproteins can be mutated to shift their pH optimum for fusion triggering (Steinhauer et al, Proc. Natl. Acad. Sci. USA 1996, 93, 12873-12878). 8) Membrane Glycoproteins from Poxviruses. The ability of poxviruses to cause cell fusion at neutral pH correlates strongly with a lack of HA production. (Ichihashi & Dales, Virology, 1971, 46, 533-543). Wild type vaccinia virus, an HA-positive orthopoxvirus, does not cause cell fusion at neutral pH, but can be induced to do so by acid pH treatment of infected cells (Gong et al, Virology, 1990, 178, 81-91). In contrast, wild type rabbitpox virus, which lacks a HA gene, causes cell fusion at neutral pH. However, inactivation of the HA or SPI-3 (serpin) genes in HA-positive orthopoxviruses leads to the formation of syncytia by fusion of infected cells at neutral pH (Turner & Moyer, J. Virol. 1992, 66, 2076-2085). Current evidence indicates that the SPI-3 and HA gene products act through a common pathway to control the activity of the orthopoxvirus fusion-triggering viral glycoproteins, thereby preventing fusion of cells infected with wild type virus. 9) Membrane Glycoproteins of Other Replicating Viruses. Replicating viruses are known to encode fusogenic viral membrane glycoproteins, which viruses include but are not limited to mumps virus (hemagglutinin neuraminidase, SwissProt P33480; glycoproteins F1 and F2, SwissProt P334,81), West Nile virus (Genbank Acc. Nos. M12294 and M10103), herpes simplex virus (see above), Russian Far East encephalitis, Newcastle disease virus (see above), Venezuelan equine encephalomyelitis (Genbank Acc. No. L044599), rabies (Genbank Acc. No. U11736 and others), vaccinia (EMBL accession X91135) and varicella (GenPept U25806; Russell, 1994, Eur. J. Cancer, 30A, 1165-1171). Modifications to Membrane Glycoproteins to Obtain Enhanced Induction of Syncytium Formation Certain modifications can be introduced into viral membrane glycoproteins to enhance profoundly their ability to induce the formation of syncytia. 1) Truncation of the cytoplasmic domains of a number of retroviral and herpesvirus glycoproteins has been shown to increase their fusion activity, sometimes with a simultaneous reduction in the efficiency with which they are incorporated into virions (Rein et al, J. Virol. 1994, 68 1773-1781; Brody et al, J. Virol. 1994, 68, 4620-4627; Mulligan et al, J. Virol. 1992, 66, 3971-3975; Pique et al, J. Virol. 1993, 67, 557-561; Baghian et al, J. Virol. 1993, 67, 2396-2401; Gage et al, J. Virol. 1993, 67, 2191-2201). 2) Transmembrane domain swapping. Transmembrane domain swapping experiments between MLV and HTLV-1 have shown that envelopes which are readily fusogenic in cell-to-cell assays and also efficiently incorporated into virions may not necessarily confer virus-to-cell fusogenicity (Denesvre et al., J. Virol. 1996, 70, 4380-4386). Modifications to Membrane Glycoproteins to Obtain Enhanced Selectivity of Syncytium Induction 1) Introduction of novel binding specificities into the fusogenic membrane glycoprotein such that the glycoprotein may recognize a selected receptor on a target cell, and thereby to target their fusogenic activities to specific cell types that express the targeted receptors. The fusogenic membrane glycoprotein may be modified so as to be capable of binding to a selected cell surface antigen. The altered glycoprotein may be tissue selective, as any tissue may give rise to a malignancy. Possible target antigens are preferentially expressed on breast, prostate, colon, ovary, testis, lung, stomach, pancreas, liver, thyroid, haemopoietic progenitor, T cells, B cells, muscle, nerve, etc. Additional possible target antigens include true tumor-specific antigens and oncofetal antigens. For example, B lymphocytes are known to give rise to at least 20 different types of haematological malignancy, with potential target molecules including CS10, CD19, CD20, CD21, CD22, CD38, CD40, CD52, surface IgM, surface IgD, idiotypic determinants on the surface of Ig, MHC class II, receptors for IL2, IL4, IL5, IL6, etc. Fusogenic membrane glycoproteins may be modified so as to contain receptor binding components of any ligand, for example, including monoclonal antibodies, naturally occurring growth factors such as interleukins, cytokines, chemokines, adhesins, integrins, neuropeptides, and non-natural peptides selected from phage libraries, and peptide toxins such as conotoxins, agatoxins. 2) Introduction of protease-dependencies into fusogenic viral membrane glycoproteins and thereby to localize the fusogenic activity to specific microenvironments that are rich in the appropriate activating proteases (See “Protease targets” below; see also, Cosset & Russell, Gene Therapy, 1996, 3, 946-956.) Protease Targets There appear to be a large number of membrane proteases which are preferentially expressed on the surfaces of tumor cells. They have been implicated in a variety of processes that contribute to disease progression and treatment resistance such as invasion, metastasis, complement resistance. A) Membrane proteases involved in complement resistance. The human melanoma cell line SK-MEL-170 is resistant to complement-mediated lysis. The molecular basis for this complement resistance has been defined as a membrane protease p65 which rapidly and specifically cleaves C3b deposited on the SK-MEL-170 cell surface (Ollert et al, Cancer Res. 1993, 53, 592-599). B) Prostate-specific antigen. The proteases present in ejaculated semen are evident in that ejaculated semen is immediately turned into a viscous gel which liquifies within 20 minutes. PSA is a prostatic kallikrein-like serine protease which cleaves the amino acid sequence Tyr-Xaa and participates in this-liquefaction process by cleaving semenogelin, the predominant protein in the coagulated part of the ejaculate (Lilja et al, J. Clin. Invest, 1987, 80, 281-285). PSA is produced exclusively by prostatic epithelial cells and is a useful marker for prostatic cancer. PSA has also been shown to cleave IGFBP-3, greatly reducing its affinity for insulin-like growth factor (IGF-1) (Cohen et al., 3. Endocrinol. 1994, 142, 407-415). PSA circulating in plasma is inactive because it is bound to serpins but it has been postulated that local release of PSA in metastatic foci of prostatic cancer might lead to the release of IGF1 by cleaving IGFBP binding protein 3 thereby enhancing tumor growth (Cohen et al J. Endocrinol. 1994 Vol. 142 p 407-415). C) Procoagulant proteases: deposition of fibrin on cancer cells may protect them from the immune system and participation of coagulation enzymes in metastasis has been suggested (Dvorak, Hum. Pathol, 1987, 18, 275-284). Membrane-associated procoagluants which may be of significance in this respect include tissue factor (Edwards et al. Thromb. Haemostasis, 1993, 6, 205-213), an enzyme that directly activates factor X (Gordon & Cross, J. Clin. Invest. 1981, 67, 1665-1671), and the activated product of that reaction, factor Xa, which directly converts prothrombin to active thrombin (Seklya et al, J. Biol. Chem. 1994, 269, 32441-32445) by cleaving C-terminal to the sequence Ile-Glu-Gly-Arg (SEQ ID NO:14) after amino acids 327 and 363 of the prothrombin molecule. The protease-sensitive cleavage site PLGLWA (SEQ ID NO:15) is cleaved by GLA and by MT1-MMP, a membrane associated MMP on human tumor cells (Ye et al., 1995, Biochem. 34:4702; and Will et al., 1996, Jour. Biol. Chem. 271). D) Plasminogen activation system: plasmin is a broad spectrum trypsin-like protease that degrades fibrin and ECM proteins including laminin, thrombospondin and collagens and that activates other latent matrix-degrading proteases such as collagenases. The expression of protease activity by tumor cells is proposed to facilitate their penetration of basement membranes, capillary walls, and interstitial connective tissues, allowing them to spread to other sites and establish metastases (Dano et al, Adv. Cancer Res. 1985, 44, 139-266). Plasminogen is an abundant plasma protein (Mr=90,000) normally present at a concentration of about 2 gM. Most cell types analyzed, except erythrocytes, have a high density of low affinity (0, 1-2.0 μM) plasminogen binding sites which recognize the lysine binding sites associated with the kringle domains of plasminogen (Redlitz & Plow, Clin. Haem. 1995, 8, 313-327). Cell-bound plasminogen is activated by a single peptide bond cleavage to form plasmin which is composed of a disulfide-linked heavy chain (Mr=60,000, containing five kringle motifs) and light chain (Mr=24,000 containing the seine proteinase catalytic triad). Activation of plasminogen to plasmin is mediated primarily by cell-bound u-PA or t-PA (see below). Cell bound plasmin is more active than soluble plasmin and is resistant to inactivation by the alpha-2-antiplasmin present in serum, but is rapidly inactivated after dissociation from the cell (Stephens et al, J, Cell Biol, 1989, 108, 1987-1995). The protease-sensitive cleavage site in plasminogen is Arg-Val at positions 580 and 581; cleavage occurs between the two residues. E) Plasminogen Activators. Urokinase plasminogen activator (u-PA) is involved in cell-mediated proteolysis during wound healing, macrophage invasion, embryo implantation, signal transduction, invasion and metastasis. Pro-uPA is usually released by cells as a single-chain of 55 kDa (scuPA), and binds to its GPI-anchored cellular receptor (uPAR-Kd 0.05-3.0 nM) where it is efficiently converted to its active (two-chain) form by plasmin or other protease. Thrombin inactivates the active form of u-PA (Ichinose et al, J. Biol. Chem. 1986, 261, 3486-3489). The activity of cell-bound u-PA is regulated by three inhibitors, PAI-1, PAI-2 and protease nexin (PN) which can bind to the cell-bound enzyme resulting in its endocytic sequestration from the cell surface (Conese and Blasi, Clin. Haematol. 1995, 8, 365-389). In cancer invasion there appears to be a complex interplay between the various components of the plasmin-plasminogen activator system. uPAR clustering on the cell surface serves to focus the process of plasmin-mediated pericellular proteolysis at the invading front of the tumor. pro-u-PA, uPAR, PAI-1 and PAI-2 can be produced in varying amounts by the cancer cells, or by nontransformed stromal cells at the site of tumor invasion and their production by these different cell types can be regulated by a variety of stimuli (Laug et al, Int. J. Cancer, 1992, 52, 298-304; Ciambrone & Mckeown-Longo, J. Biol. Chem. 1992, 267, 13617-13622; Kessler & Markus, Semin, Thromb. Haemostasis, 1991, 17, 217-224; Lund et al, EMBO J., 1991, 10, 3399-3407). Thus, various different cell types can contribute to the assembly on the tumor cells of all the components of the proteolytic machinery that is required for matrix destruction. F) Trypsin-like proteases: tumor-associated trypsin inhibitor (TATI) is a 6-kDa protease inhibitor whose levels are elevated in patients with advanced cancer (Stenman et al, Int. J. Cancer, 1982, 30, 53-57). In search of the target protease for the TATI, two trypsin-like proteases have been purified from the cyst fluid of mucinous ovarian tumors (Koivunen et al, J. Biol. Chem. 1989, 264, 14095-14099). Their substrate specificities were found to be very similar to those of pancreatic trypsins 1 and 2 and they were found to be efficient activators of pro-urokinase but could not activate plasminogen directly. Trypsin cleaves C-terminal to Lys or Arg residues. G) Cathepsin D. this is a pepstatin-sensitive, lysosomal aspartyl protease which is secreted in large amounts by breast cancer cells and by a variety of other cancer cell types. Purified cathepsin D and conditioned medium from cathepsin D-secreting cells have been shown to degrade extracellular matrix at pH 4.5, but not at neutral pH (Briozzo et al, Cancer Res. 1988, 48, 3688-3692). It has therefore been proposed that the enzyme may be an important facilitator of tumor invasion when it is released into an acidic (pH <5.5) microenvironment. One factor distinguishing it from other protease classes is that it can act at a distance from the cancer cell after it has been secreted. H) Cathepsin B, L: leupeptin-sensitive lysosomal cysteinyl proteases which act at acidic pH. These and other cathepsins, such as cathepsin D (above), are dipeptidylpeptide hydrolases, which cleave adjacent to certain dipeptides. For example, cathepsin B is a dihistidyl carboxypeptidase. Methods of Treating a Cell Proliferative Disorder According to the Invention The invention contemplates treatment of cell proliferative disorders using a syncytium-inducing polypeptide to induce syncytium formation of unwanted cells. Cell proliferative disorders include treatment of malignant diseases, as in cancer gene therapy, as well as diseases involving immunosuppression wherein unwanted lymphocytes proliferate, as in rheumatoid arthritis, or wherein unwanted keratinocytes (skin cells) proliferate, as in psoriasis. The primary target cells in which the syncytium-inducing polypeptide is expressed (index cells) can be stationary cells (e.g. the neoplastic cells or stromal elements in a solid tumor) or migratory cells (e.g. T lymphocytes, B lymphocytes and other haemopoietic cells or migratory neoplastic cells in haematological malignancies). The secondary target cells (with which the syncytium-inducing polypeptide-expressing target cells will fuse) may likewise be stationary or migratory. The target cells can be transduced ex vivo or in vivo by the syncytium-inducing polypeptide-encoding vectors. Any vector system, whether viral or nonviral can be used to deliver a gene or genes encoding a syncytium-inducing polypeptide to the target cells. Targeting elements may be included in the vector formulation to enhance the accuracy of gene delivery to the target cells and tissue/tumor-selective regulatory elements can be included in the vector genome to ensure that the expression of a gene or genes encoding a syncytium-inducing polypeptide is restricted to the chosen target cells. Genes encoding syncytium-inducing polypeptides could therefore be used in various ways for therapeutic benefit. The aim in all cases is to destroy unwanted target cells by causing them to fuse with syncytium-inducing polypeptide-expressing index cells. The initial targets for gene transfer are therefore the index cells, but the ultimate targets of the therapeutic strategy are the cells with which they fuse. Many different therapeutic strategies can be envisaged. For example, where the aim of the protocol is to destroy nepoplastic cells in the patient, the index cells need not be neoplastic. Migratory T lymphocytes expressing tumor-selective syncytium-inducing polypeptides might form syncytia exclusively with neoplastic cells. Local expression of tumor-selective (or, less optimally, nonselective) syncytium-inducing polypeptides in the stromal, vascular endothelial or neoplastic cells in solid tumors might lead to recruitment of neighboring neoplastic cells into syncytia. For leukemias and other haematogenous malignancies, expression of leukemia-selective syncytium-inducing polypeptides in vascular endothelium or stromal bone marrow cells might lead to recruitment of circulating leukaemic cells into stationary syncytia. Alternatively, expression of leukaemia-selective syncytium-inducing polypeptides in circulating T cells or in the leukaemic cells themselves might allow these cells to nucleate the formation of leukaemic cell syncytia in heavily infiltrated tissues, or lead to recruitment of leukaemic cells into recirculating syncytia. Another method of determining whether the inventive treatment methods are successful is to perform a biopsy of tissue that is targeted for syncytium formation, and to observe cells of the tissue in a microscope for formation of syncytia. How to Determine Induction of Syncytium Formation According to the Invention Induction of syncytium formation may be determined in vitro as described herein. Syncytium formation in vivo is determined via tissue biopsy from a candidate patient treated according to the invention, wherein under direct visualization large multinucleate areas are observed in a tissue section. Dosage, Pharmaceutical Formulation and Administration A vector containing a gene encoding a syncytium-inducing polypeptide according to the invention may be administered directly to a patient or may be administered utilizing an ex vivo approach whereby cells are removed from a patient or donor, transduced with the vector containing a therapeutic nucleic acid sequence encoding a syncytium inducing polypeptide and reimplanted into the patient. A vector or host cells containing a particular therapeutic nucleic acid sequence encoding a syncytium-inducing polypeptide according to the invention can be administered prophylactically, or to patients having a cell proliferative disease or condition treatable by supplying and expressing the gene encoding the syncytium-inducing polypeptide by means of an appropriate delivery vehicle, e.g., a liposome, by use of iontophoresis, electroporation and other pharmacologically approved methods of delivery. Routes of administration may include intramuscular, intravenous, aerosol, oral (tablet or pill form), topical, systemic, ocular, as a suppository, intraperitoneal and/or intrathecal. Some methods of delivery that may be used include: viral or non-viral vector delivery of a DNA, encapsulation in liposomes, transfection of cells ex vivo with subsequent reimplantation or administration of the transfected cells. Viral vectors that can be used to deliver foreign nucleic acid into cells include but are not limited to retroviral vectors, adenoviral vectors, adeno-associateclviral vectors, herpesvirual vectors, and Semliki forest viral (alphaviral) vectors. Defective retroviruse are well characterized for use in gene transfer for gene therapy purposes (for a review see Miller, A.D. (1990) Blood 76:271). Protocols for producing recombinant retroviruses and for infecting cells in vitro or in vivo with such viruses can be found in Current Protocols in Molecular Biology , Ausubel, F. M. et al. (eds.) Greene Publishing Associates, (1989), Sections 9.10-9.14 and other standard laboratory manuals. Adenovirus can be manipulated such that it encodes and expresses a gene product of interest but is inactivated in terms of its ability to replicate in a normal lytic viral life cycle. See for example Berkner et al. (1988) BioTechniques 6:616; Rosenfeld et al. (1991) Science 252:431-434; and Rosenfeld et al. (1992) Cell 68:143-155. Suitable adenoviral vectors derived from the adenovirus strain Ad type 5 d1324 or other strains of adenovirus (e.g., Ad2, Ad3, Ad7 etc.) are well known to those skilled in the art. Adeno-associated virus (AAV) is a naturally occurring defective virus that requires another virus, such as an adenovirus or a herpes virus, as a helper virus for efficient replication and a productive life cycle. (For a review see Muzyczka et al. Curr. Topics in Micro. and Immunol. ( 1992) 158:97-129). An AAV vector such as that described in Tratschin et al. (1985) Mol. Cell. Biol. 5:3251-3260 can be used to introduce nucleic acid into cells. A variety of nucleic acids have been introduced into different cell types using AAV vectors (see for example Hermonat et al. (1984) Proc. Natl. Acad. Sci. USA 81:6466-6470; and Tratschin et al. (1985) Mol. Cell. Biol. 4:2072-2081). Other types of delivery strategies useful in the present invention, include: injection of naked DNA, injection of charge modified DNA, or particle carrier drug delivery vehicles. Unmodified nucleic acid sequences, like most small molecules, are taken up by cells, albeit slowly. To enhance cellular uptake, the vector containing a sequence encoding a syncytium-inducing polypeptide may be modified in ways which reduce its charge but will maintain the expression of specific functional groups in the final translation product. This results in a molecule which is able to diffuse across the cell membrane, thus removing the permeability barrier. Chemical modifications of the phosphate backbone will reduce the negative charge allowing free diffusion across the membrane. This principle has been successfully demonstrated for antisense DNA technology which shows that this is a feasible approach. In the body, maintenance of an external concentration will be necessary to drive the diffusion of the modified nucleic acid sequence into the cells of the tissue. Administration routes which allow the tissue to be exposed to a transient high concentration of the nucleic acid sequence encoding a syncytium-inducing polypeptide, which is slowly dissipated by systematic adsorption are preferred. Intravenous administration with a carrier designed to increase the circulation half-life of the nucleic acid sequence can be used. The size and composition of the carrier restricts rapid clearance from the blood stream. The carrier, made to accumulate at the desired site of transfer, can protect the nucleic acid sequence from degradative processes. Delivery vehicles are effective for both systematic and topical administration. They can be designed to serve as a slow release reservoir, or to deliver their contents directly to the target cell. An advantage of using direct delivery vehicles is that multiple molecules are delivered per uptake. Such vehicles have been shown to increase the circulation half-life of drugs which would otherwise be rapidly cleared from the blood stream. Some examples of such specialized drug delivery vehicles which fall into this category are liposomes, hydrogels, cyclodextrins, biodegradable nanocapsules, and bioadhesive microspheres. From this category of delivery systems, liposomes are preferred. Liposomes increase intracellular stability, increase uptake efficiency and improve biological activity. Liposomes are hollow spherical vesicles composed of lipids arranged in a similar fashion as those lipids which make up the cell membrane. They have an internal aqueous space for entrapping water soluble compounds and range in size from 0.05 to several microns in diameter. Several studies have shown that liposomes can deliver nucleic acids to cells and that the nucleic acid remains biologically active. For example, a liposome delivery vehicle originally designed as a research tool, Lipofectin, has been shown to deliver intact mRNA molecules to cells yielding production of the corresponding protein. Liposomes offer several advantages: They are non-toxic and biodegradable in composition; they display long circulation half-lives; and recognition molecules can be readily attached to their surface for targeting to tissues. Finally, cost effective manufacture of liposome-based pharmaceuticals, either in a liquid suspension or lyophilized product, has demonstrated the viability of this technology as an acceptable drug delivery system. Other controlled release drug delivery systems, such as nanoparticles and hydrogels, may be potential delivery vehicles for a nucleic acid sequence encoding an episomal vector containing a therapeutic nucleic acid sequence or sequences. These carriers have been developed for chemotherapeutic agents and protein-based pharmaceuticals, and consequently, can be adapted for nucleic acid delivery. DNA, cells or proteins according to the invention may also be systematically administered. Systemic absorption refers to the accumulation of drugs in the blood stream followed by distribution throughout the entire body. Administration routes which lead to systemic absorption include: intravenous, intramuscular, subcutaneous, intraperitoneal, intranasal, intrathecal and ophthalmic. Each of these administration routes exposes the nucleic acid sequence encoding a syncytium inducing polypeptide to an accessible targeted tissue. Subcutaneous administration drains into a localized lymph node which proceeds through the lymphatic network into the circulation. The rate of entry into the circulation has been shown to be a function of molecular weight or size. Liposomes injected intravenously show accumulation in the liver, lung and spleen. The composition and size can be adjusted so that this accumulation represents 30% to 40% of the injected dose. The remaining dose circulates in the blood stream for up to 24 hours. The dosage will depend upon the disease indication and the route of administration but should be between 1-1000 μg of DNA or protein/kg of body weight/day or 10,000-100,000 transfected cells/day. The duration of treatment will extend through the course of the disease symptoms, possibly continuously. The number of doses will depend upon disease delivery vehicle and efficacy data from clinical trials. Where a syncytium-inducing polypeptide is administered, via DNA encoding the polypeptide or via a host cell containing the DNA or via the protein itself, in a pharmaceutical formulation, the formulation may be mixed in a physiologically acceptable diluent such as water, phosphate buffered saline, or saline, and will exclude cell culture medium, particularly culture serum such as bovine serum or fetal calf serum, <0.5%. The following examples are offered by way of illustration and are not intended to limit the invention in any manner. EXEMPLIFICATION The following examples demonstrate the preparation and testing of therapeutic uses of genes encoding (targeted) fusogenic membrane glycoproteins for gene therapy of cancer. The examples specifically describe the preparation of a retroviral vector and retroviral vector stock containing genes encoding measles virus F and H glycoproteins, the use of these vectors to induce syncytium formation between HF-transduced murine fibroblasts and nontransduced human tumor cells, and administration of the transduced fibroblasts to tumor-bearing mice to reduce tumor growth. When expressed concurrently in the same cell, measles virus F and H glycoproteins can mediate cell-cell fusion with neighboring cells, provided the neighboring cells express the measles virus receptor (CD46). Human cells express the CD46 measles virus receptor, whereas murine cells do not. In the experiments described below, a retroviral vector capable of transferring the measles virus F and H genes is used to demonstrate the therapeutic potential of gene therapy vectors encoding targeted or nontargeted fusogenic viral membrane glycoproteins for cancer therapy. The vectors can be used for direct gene transfer to tumor cells or for transduction of nontumor cells which are then employed for their selective antitumor effect. Example 1 1.1 Construction of Retroviral Vector Plasmid Coding for Measles Virus F and H Glycoproteins. The plasmid shown schematically in FIG. 1 (not to scale) is constructed using standard cloning methods. In relation to FIG. 1 , LTR=Moloney murine leukaemia virus long terminal repeat; ?=Moloney murine leukaemia virus packaging signal; IRES poliovirus internal ribosome entry site; H=measles virus H glycoprotein coding sequence; F=measles virus F glycoprotein coding sequence; PHLEO=phleomycin resistance marker; the dotted line represents the vector backbone (either pUC or pBR322-based). In brief, the coding sequence of the measles virus H gene is cloned from pCGH5 (Cathomen et al, 1995, Virology, 214, 628-632), into the NotI site of the retroviral vector plasmid pGCP (which contains the poliovirus internal ribosome entry site flanked by NotI and ClaI cloning sites). The measles virus F gene is then cloned from pCGF (Cathomen et al, 1995, Virology, 214, 628-632) into the ClaI site of the same vector, 5′ of the internal ribosome entry site to produce the vector named pHF. A phleomycin selectable marker gene is then introduced into the vector 5′ of the 5′ LTR. 1.2 Preparation of Retroviral Vector Stocks. The plasmid pBF is transfected into amphotropic retroviral packaging cell lines which were derived from murine fibroblasts. Suitable packaging cell lines are widely available and include the NIH3T3-derived cell lines PA317 and GP+env AM12. Stably transfected packaging cells are selected in phleomycin 50 ug/ml and used as a source of HF retroviral vectors capable of efficiently transferring the measles virus F and H genes to human and murine target cells. 1.3 Transduction of Transplantable Human Tumor Cell Lines Leading to Formation of Multinucleated Syncytia Through the Induction of Cell-cell Fusion. The HF retroviral vector stocks are used to transduce a panel of human tumor cell lines which are subsequently observed for the formation of multinucleated syncytia, expected to be maximal 24 to 72 hours after retroviral transduction of the cells. The tumor cell lines are grown to near-confluency before transduction. Examples of tumor cell lines that can be used for this assay are A431 (epidernoid carcinoma), HT1080 (fibrosarcoma), EJ (bladder carcinoma), C175 (colon carcinoma), MCF7 (breast carcinoma), HeLa (cervical carcinoma), K422 (follicular lymphoma), U266 (myeloma). Most, if not all, of the human tumor cell lines tested undergo extensive cell-cell fusion shortly after transduction with the HF retroviral vector. 1.4 Inoculation of Nude Mice with Transplantable Human Tumor Cell Lines and Subsequent in vivo Transfer of H and F Genes to the Tumor Deposits: Demonstration that Fusogenic Membrane Glycoproteins Mediate Tumor Destruction in the Absence of a Functional Immune System. Mice are challenged by subcutaneous inoculation into the flank with 10 7 human tumor cells. Suitable cell lines for use in these experiments are listed above in Section 3. Between one and fourteen days after subcutaneous inoculation with tumor cells, the growing tumor xenografts are inoculated with concentrated HF retroviral vector stocks or by control vector stocks encoding either measles F or measles H glycoproteins. Tumor growth is slowed or completely inhibited by HF retroviral vector inoculation but not by inoculation of control (H or F alone) vectors. 1.5 Transduction of Murine Fibroblasts; Lack of Cell-cell Fusion and Absence of Multinucleated Syncytia. The HF retroviral vector stocks are used to transduce murine NM3T3 fibroblasts which are subsequently observed for the formation of multinucleated syncytia. No cell-cell fusion occurs and no multinucleated syncytia are observed. 1.6 Mixing of HF-transduced Murine Fibroblasts with Nontransduced Human Tumor Cells Leading to the Formation of Multinucleated Syncytia Through the Induction of Cell-cell Fusion Between HF-transduced Murine Fibroblasts and Nontransduced Human Tumor Cells. The HF retroviral vector stocks are used to transduce murine N1H3T3 fibroblasts which are subsequently mixed, at various ratios from 1:1 to 1:10,000, with nontransduced human tumor cell lines. The mixed cell populations are then plated at high density and observed for the formation of multinucleated syncytia. Cell-cell fusion occurs between HF-transduced N1H3T3 fibroblasts and nontransduced human tumor cells leading to the formation of multiple hybrid syncytia, each one nucleating on a transduced NIH3T3 cell. Syncytia are not observed in control cultures in which nontransduced N1H3T3 cells are mixed with nontransduced human tumor cells. 1.7 Inoculation of Nude Mice with Mixtures of HF-transduced Murine Fibroblasts and Nontransduced Human Tumor Cells: Demonstration that Fusogenic Membrane Glycoproteinexpressing Cells Mediate Tumor Destruction By Recruitment into Syncytia of Nontransduced Human Tumor Cells. The HF retroviral vector stocks are used to transduce murine NIH3T3 fibroblasts which are subsequently mixed, at varying ratios from 1:1 to 1:10,000, with nontransduced human tumor cell lines. Mixed cell populations containing 10 7 tumor cells admixed with from 10 3 to 10 7 HF-transduced NIH3T3 cells are then inoculated subcutaneously into the flanks of nude (BALBC nu/nu) mice and the mice are monitored for the growth of subcutaneous tumors whose diameters are recorded daily. Control mice are challenged with 10 7 nontransduced human tumor cells. Tumor growth is slowed or completely inhibited by admixed HF-transduced NIH3T3 fibroblasts which express the measles virus F and H glycoproteins, but not by admixed nontransduced NIH3T3 fibroblasts. A composition according to the invention is determined to be useful according to treatment methods of the invention wherein tumor growth (e.g., malignant tumor growth) is reduced to the extent that the tumor remains the same size (i.e., does not increase by weight or measurement) or the tumor is reduced in weight or size by at least 25% in an animal model of the cancer (e.g., the nude mouse model described above) or in a patient. Those compositions which are particularly useful according to the invention will confer tumor reduction of at least 50%. Alternatively, a tissue biopsy is performed in order to observe syncytium formation via direct visualization. A composition according to the invention also is determined to be useful according to treatment methods of the invention wherein syncytium formation is observed to the extent that multinucleate areas of cytoplasm are observed in a tumor tissue biopsy during the course of treatment. Example 2 Display of EGF and IGF on Measles H Glycoprotein Materials and Methods Plasmid Construction Unmodified Measles Virus (MV) F and MV H protein were encoded by the expression plasmids pCG-F and pCG-H, respectively (Catomen et al, Virology 214 p628, 1995). To make the chimeric MV H expression constructs, first the SfiI site in pCG-H was deleted, so that we could introduce our displayed ligands as SfiI/NotI fragments. This was done by digesting pCG-H with SfiI, endfilling the cohesive ends using Klenow fragment of E. coli DNA polymerase and dNTPs, then re-ligating the purified product. This construct was tested to check that it was still functional in cell fusion assays (see later). We could now make constructs which would enable us to insert ligands as SfiI/NotI fragments. To make the construct pCG-H SfiI/NotI, which introduces the SfiI/NotI cloning site at the C-terminus of the MV H sequence, oligonucleotides HXmabak (5′-CCG GGA AGA TGG AAC CAA TGC GGC CCA GCC GGC CTC AGG TTC AGC GGC CGC ATA GTA GA-3′, Seq ID No. 1) and HSpefor (5′-CTA GTC TAC TAT GCG GCC GCT GAA CCT GAG GCC GGC TGG GCC GCA TTG GTT CCA TCT TC-3′, Seq ID No. 2) were made. When annealed together these two oligonucleotides form a DNA fragment with XmaI and SpeI cohesive ends. This fragment was ligated to the XmaI/SpeI digested pCG-H(Sfi-) backbone. The correct sequence of the construct was verified by DNA sequencing. To make the construct pCG-H FXSfiI/NotI, where there is a FXa protease cleavage signal before the SfiI/NotI cloning sites at the C-terminus of the MV H sequence, oligonucleotides HXmaFXbak (5′-CCG GGA AGA TGG AAC CAA TAT CGA GGG AAG GGC GGC CCA GCC GGC CTC AGG TTC AGC-3′, Seq ID No. 3) and HNotFXfor (5′-GGC CGC TGA ACC TGA GGC CGG CTG GGC CGC CCT TCC CTC GAT ATT GGT TCC ATC TTC-3′, Seq ID No. 4) were made. When annealed together these two oligonucleotides form a DNA fragment with XmaI and NotI cohesive ends. This fragment was ligated to the XmaI/NotI digested pCG-H SfiI/NotI backbone. The correct sequence of the constructs was verified by DNA sequencing. Constructs pCG-H EGF R− , pCG-H XEGF R− , pCG-H IGF and pCG-H XIGF were made by transferring the SfiI/NotI EGF and IGF fragments from pEGF R− -GS1A1 (Peng, PhD Thesis) and pIGFA1 (IA) (WO97/03357, Russell et al.) respectively into SfiI/NotI digested pCG-H SfiI/NotI and pCG-H FXSfiI/NotI. FIG. 2 shows a diagrammatic representation of the four constructs. To enable us stably to express the chimeric H proteins in mammalian cells, we need to have a selectable marker in the expression construct. This, was achieved by transferring the whole MV H gene with the SfiI/NotI cloning site at its C-terminus into the envelope expression construct, EMol (Cosset et al, J. Virol. 69 p6314, 1995). So, to make pFBH SfiI/Not, pCG-H SfiI/Not was cut with ClaI and SpeI to release the H gene with the SfiI/NotI cloning site and EMol was cut with XbaI and ClaI to remove EGF and the Mo envelope sequence giving us the backbone. The cohesive ends of both fragments were endfilled using Klenow fragment of E. coli DNA polymerase and dNTPs. The backbone was phosphatased and the purified fragments were ligated together. The construct was checked by diagnostic digests for the correct orientation. To make the construct pFBH FXSfiI/Not, pCG-H FXSfiI/Not was cut with NsiI and NotI to release part of the H sequence with a FXa protease cleavage signal and the SfiI/NotI cloning site at its C-terminus. pFBH SfiI/Not was also cut with NsiI and NotI to give us the backbone, and the two fragments were ligated together. The construct was checked by sequencing for correctness. Constructs pFBH EGF R− , pFBH XEGF R− , pFBH IGF and pFBH )IGF were made by transferring the SfiI/NotI EGF and IGF fragments from pEGF R− GS1A1 and pIGFA1 respectively into SfiI/NotI digested pFBH SfiI/Not and pFBH FXSfiI/NotI. FIG. 3 shows a diagrammatic representation of the four constructs. To make the construct pFBH, where there is no C-terminal extension, pCG-H was cut with ClaI and SpeI to release the H gene and EMo1 was cut with XbaI and ClaI to remove EGF and the Mo envelope sequence giving us the backbone. The cohesive ends of both fragments were endfilled using Klenow fragment of E. coli DNA polymerase and dNTPs. The backbone was phosphatased and the purified fragments were ligated together. The construct was checked by diagnostic digests for the correct orientation. Cell Lines C170 cells, a human colon cancer cell line (Durrant et al, Br. J. Cancer 53 p37, 1986), and Human A431 cells (ATCC CRL1555) were grown in DMEM supplemented with 10% fetal calf serum. To enable easy detection of cell-cell fusion the C170 and A431 cells were infected with A viral supernatant, harvested from TELCeB6 producer cells (Cosset et al, J. Virol. 69 p6314, 1995), which transfers a gene coding for β-galactosidase tagged with a nuclear localisation signal. Single colonies of cells were grown up and clones that stained blue were picked. These blue staining C170 and A431 cells were used in cell fusion assays. The different MV H expression constructs pFBH, pFBH EGF R− , pFBH XEGF R− , pFBH IGF and pFBH )UGF (5 mg DNA) were transfected into TELCeB6 cells (Cosset et al, J. Virol. 69 p7430, 1995) using 30 ml Superfect (Qiagen). Stable phleomycin (50 mg/ml) resistant colonies were expanded and pooled. Cells were grown in DMEM supplemented with 10% fetal calf serum. Immunoblots To obtain cell lysates, TELCeB6 cells stably transfected with the MV H constructs were lysed in a 20 mM Tris-HCl buffer (pH 7.5) containing 1% Triton X-100, 0.05% SDS, 5 mg/ml sodium deoxycholate, 150 mM NaCl and 1 mM phenylmethylsulfonylfluoride. Lysates were incubated for 10 mins at 4° C. and then centrifuged for 10 mins at 10,000×g to pellet the unwanted nuclei. Aliquots of the cell lysates (50 μl) were then separated on a 10% polyacrylamide gel under reducing conditions followed by transfer of the proteins onto nitrocellulose paper (NC) (Amersham). The NC was blocked with 5% skimmed milk powder (Marvel) in PBS-0.1% Tween 20 (PBST) for 30 mins at room temperature. The MV H proteins were detected by incubating the NC for 3 hours with a MV H specific rabbit serum (1 in 3000) which was raised against a peptide derived from the amino terminus of the H protein (kind gift from Roberto Cattaneo, University of Zurich). After extensive washing with PBST the NC was incubated with horseradish peroxidase-conjugated swine anti-rabbit antibodies (1 in 3000) (DAKO, Denmark) for 1 hour at room temperature. Proteins were visualised using the enhanced chemiluminescence kit. (Amersham Life Science, UK). Cell-cell Fusion Assays Blue staining C170 and A431 cells were seeded at 5×10 5 cells/well in six-well plates and incubated at 37° C. overnight. MV H expression constructs, pCG-H, pCG-H EGF R− , pCG-H XEGF R− , pCG-H IGF and pCG-H XMGF, were co-transfected into the C170 and A431 cells along with the MV F expression construct, pCG-F. Transfections were carried out using 2.5 mg of the relevant plasmids and 15 ml Superfect. After transfection the cells were incubated with regular medium for 48-72 hrs, until syncytia could be clearly seen. X-Gal staining for detection of β-galactosidase activity was performed as previously described (Takeuchi et al., 1994). Fusion efficiency was scored (−no syncytia, +definite syncytia, ++abundant syncytia). Results Construction of Chimeric MV H Expression Constructs A series of expression constructs were made which code for chimeric MV H proteins in which the ligands EGF and IGF are fused at the C-terminus of the H protein with or without a Factor Xa-cleavable linker ( FIGS. 2 and 3 ). FIG. 2 shows constructs which are driven by the CMV promoter, but these constructs contain no selectable marker for selection in mammalian cells. Expression of the constructs in FIG. 3 is driven by a retroviral LTR and these constructs contain the selectable marker, phleomycin, for selection in mammalian cells. Expression of the Chimeric MV H Proteins The different MV H expression constructs, pFBH, pFBH EGF R− , pFBH XEGF R− , pFBH IGF and pFBH XIGF were stably transfected into TELCeB6 cells. Immunoblots were performed on cell lysates prepared from these stable TELCeB6 transfectants. FIG. 4 shows that all chimeric MV H proteins are expressed to a comparable level to that of the wild type MV H protein. Moreover, the blot shows that the displayed domains are not spontaneously cleaved from the chimeric MV H glycoproteins. Cell-cell Fusion Assays MV H expression constructs, pCG-H, pCG-H EGF R− , pCG-H XEGF R− , pCG-H IGF and pCG-H XIGF, were co-transfected into the β-galactosidase expressing C170 and A431 cells along with the MV F expression construct, pCG-F. The cells were stained with X-gal substrate 72 hrs after transfection to allow ease of cell-cell fusion detection. Results of the assays are shown in Tables 1 and 2 and in FIG. 5 . The chimeric MV H proteins were potent inducers of cell-cell fusion in C170 cells although their potency was slightly reduced compared to the unmodified H protein (Table 1, FIG. 5 ). Cell-cell fusion in A431 was abolished for the chimeric H proteins compared to the unmodified MV H protein which was a potent inducer of cell-cell fusion (Table 2). The results show that: 1) Foreign polypeptides can be displayed as fusions to the extreme C-terminus of the MV H protein. 2) The chimeric H glycoproteins are efficiently expressed and are functional in cell-cell fusion assays. 3) The displayed ligand can target the specificity of cell-cell fusion. TABLE 1 −pCG-F +pCG-F pCG-H − ++ pCG-H EGF − ++ pCG-H XEGF − ++ This table shows the results of cell-cell fusion on β-galactosidase expressing C170 cells. Chimeric MV H proteins are potent inducers of cell-cell fusion when co-expressed with unmodified F glycoproteins. − = no syncytia, + = definite syncytia, ++ = abundant syncytia. TABLE 2 −pCG-F +pCG-F pCG-H − ++ pCG-H EGF − − pCG-H XEGF − − This table shows the results of cell-cell fusion assay on β-galactosidase expressing A431 cells. The unmodified MV H protein is a potent inducer of cell-cell fusion when co-expressed with unmodified F glycoproteins. However, chimeric MV H proteins show no syncytia formation. − = no syncytia, + = definite syncytia, ++ = abundant syncytia. Example 3 Demonstration that GALV Envelope with Truncated Cytoplasmic Tail is Hyperfusogenic on Human Tumour Cell Lines Materials and Methods Plasmids Used The expression constructs of Measles Virus (MV) F and MV H protein were encoded by the expression plasmids pCG-F and pCG-H, respectively (Catomen et al, Virology 214 p628, 1995). FBdelPGASAF encodes the wildtype GALV envelope and FBdelPGASAF-fus encodes a C-terminally truncated GALV envelope lacking the cytoplasmic tail (see attached sequence, FIG. 6 ). Cell Lines Human C170 (Durrant et al, Br. J. Cancer 53 p37, 1986), Human A431 cells (ATCC CRL1555), Human TE671 (ATCC CRL8805), Human Hela (ATCC CCL2), and the murine cell line NIH3T3 were grown in DMEM supplemented with 10% fetal calf serum. All of these cell lines, except NIH3T3 have receptors for the GALV envelope and for the MV H glycoprotein. Cell-cell Fusion Assays Cells were seeded at 5×10 5 cells/well in six-well plates and incubated at 37° C. overnight. The fusogenic and non-fusogenic plasmids, FBdelPGASAF and FBdelPGASAF-fus, were transfected and the MV H and F expression constructs, pCG-H and pCG-F, were co-transfected into the panel of cell lines. Transfections were carried out using 2.5 mg of the relevant plasmids and 15 ml Superfect (Qiagen). After transfection the cells were incubated with regular medium for 48-72 hrs, until syncytia could be clearly seen, when fusion efficiency was scored (−no syncytia, +definite syncytia, ++abundant syncytia). Results Cell-cell Fusion Assays The fusogenic and non-fusogenic plasmids and the MV H and F expression constructs were transfected into the panel of cell lines. The cells were left for 72 hours before cell-cell fusion was scored. Results of the assays are shown in Table 3. The fusogenic GALV construct shows the same pattern of fusion ability as the MV F and H proteins show. TABLE 3 FBdelPGASAF FBdelPGASAF-fus CG-F/CG-H C170 − ++ ++ A431 − ++ ++ TE671 − ++ ++ HeLa − ++ ++ NIH3T3 − − − This table shows the results of cell-cell fusion assays on a panel of cell lines. − = no syncytia, + = definite syncytia, ++ = abundant syncytia. Example 4 Display of EGF on GALV Envelope Materials and Methods Construction of Envelope Expression Plasmids Envelope expression plasmid GALVMoT was constructed by PCR amplification of the cDNA encoding GALV env from the plasmid pMOVGaLVSEATO env (Wilson et al., J. Virol. 63, 2374-2378, 1989) using primers GalvrevXba and Galvforcla2 which were tailed with XbaI and Cla 1 restriction sites. The PCR products were then ligated into the plasmid FBMoSALF after Xbal and Cla 1 digestion. The chimeric envelope expression plasmid EXGaLVMoT was constructed by PCR amplification of the cDNA encoding GALV env from plasmid PMOVGaLVSEATO env using primers galvs 1 q and galvforcla2. Primer “galvslq” was tailed with a Not1 restriction site and contained the coding sequence for a factor Xa cleavage signal (IEGR; SEQ ID NO:14). The PCR products were ligated into the plasmid Emo after Not1 and Cla1 digestion. The sequences of the primers are shown below. The restriction enzyme sites are underlined. The coding sequence for the factor Xa cleavage signal is shown in bold. (SEQ ID NO: 5) galvslq 5′gcaaatct gcggccgca atcgaggga aggagtctgc aaaataagaacccccaccag 3′ (SEQ ID NO: 6) galvforcla2 5′cc atcgatt gatgcatggcccgag 3′ (SEQ ID NO: 7) galvrevxba 5′ctagc tctaga atggtattgctgcctgggtcc 3′ The correct sequence of both constructs was confirmed by didexoysequencing. A diagrammatic representation of the constructs is shown in FIG. 7 . Vector Production The envelope expression plasmids were transfected into the TELCeB6 complementing cell line which contains gag-pol expression plasmid and an nls LacZ retroviral vector. Stable transfectants were selected in 50 μg/ml phleomycin and pooled. Infection of Target Cells Supernatant from the transfected TELCeB6 complementing cell lines was harvested after the cells had been allowed to grow to confluency at 37° C. then placed at 32° C. for 1-3 days. The medium was changed and, after overnight incubation, the supernatant was harvested and filtered through a 0.45 μm filter. The filtered supernatants were then used to infect target cells. Adherent target cells were plated into six-well plates at approximately 10 5 cells per well on the evening prior to infection and incubated overnight at 37° C. and suspension cells were plated into six well plates at approximately 10 6 cells per well one hour before infection. Filtered viral supernatant in serum free medium was added to the target cells and incubated for 2-4 hours in the presence of 8 mg/ml polybrene. For infections involving factor Xa cleavage, the virus was incubated with 4 mg/ml of factor Xa protease in the presence of 2.5 mM CaCl 2 for 90 mins prior to infection. The retroviral supernatant was then removed from the target cells, the medium was replaced with the usual medium and the cells were placed at 37° C. for a further 48-72 hours. X gal staining for detection of β-galactosidase activity was then carried out. Results Titration of GaLVMoT and EXGaLVMoT on HT1080 Cells When these vectors were titrated on HT1080 cells, a human EGF receptor positive cell line, the titre of GaLVMoT was 10 6 efu/ml whereas that of EXGaLVMoT was 3.6×10 3 efu/ml. However, when the vector supernatant was incubated with factor Xa protease prior to infection, in order to cleave the displayed domain, the titre of GaLVMoT remained at 10 6 efu/ml whereas the titre of EXGaLVMoT was increased to 3.6×10 4 /ml (table 4). Titration of GaLVMoT and EXGaLVMoTon MDBK Cells When these vectors were titrated on MDBK cells, a bovine EGF-R positive cell line, there was a similar finding. The titre of EXGaLVMoT was reduced compared to GaLVMoT but increased ten fold upon protease cleavage (table 4). Infection of Haemopoietic Cells with EXGaLVMoT Two EGF-R negative haemopoietic suspension cell lines, HMC-1 and Meg-O1 were infected with EXGaLVMoT and gave titres (expressed a percentage blue cells) of 28.8% and 31.65% respectively. These results are similar to those previously published with the vector EXA (Fielding et al., Blood 91, 1-10, 1998). Taken in conjunction with the above data on the EGF-R positive cells, this suggests the EXGaLVMoT exhibits similar characteristics to the EXA vector where the displayed domain causes a reduction in infectivity in a receptor dependent manner. TABLE 4 Titre of GaLV vectors on EGF-R positive cells HT1080 MDBK −Xa +Xa −Xa +Xa GaLVMoT   1 × 10 6   1 × 10 6 3.5 × 10 4 2.9 × 104 EXGaLVMoT 3.6 × 10 3 3.6 × 10 4 <1 12 Conclusions 1. Wild type (GaLVMoT) and chimeric Gibbon Ape Leukaemia virus envelope expression constructs have been constructed and incorporated into retroviral vector particles which contain MLV gag-pol core particles and a Moloney MLV nlsLacZ retroviral vector, 2. Both the wild type and EGF-chimeric vectors are capable of infecting human cell lines. 3. The titre of the EGF-chimaera is considerably reduced on EGF receptor positive cell lines and can be increased by factor Xa cleavage of the displayed domain. The largest reduction in titre is seen on cell lines with the highest density of EGF receptors. 4. Thus, display of EGF as an N terminal extension of the Gibbon Ape Leukaemia virus SU glycoprotein results in altered viral tropism which is similar to that seen with display of EGF on the murine leukaemia virus envelopes (Nilson et al., Gene Ther. 3, 280, 1996) and is likely to be EGF-receptor mediated. Other Embodiments Other embodiments are within the following claims.

Disclosed are compositions comprising a recombinant nucleic acid vector including a nucleotide sequence encoding a syncytium-inducing polypeptide expressible on a eukaryotic cell surface, and a host cell containing the recombinant vector and expressing the syncytium inducing polypeptide on its cell surface, the vectors and resultant host cells expressing the syncytium inducing polypeptide being useful for selective elimination of unwanted cells.

RELATED APPLICATION [0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60/539,860, filed Jan. 27, 2004 and entitled “IDENTIFICATION OF ABERRANT MYC/TIP60 INTERACTIONS AS AN ESSENTIAL MEDIATOR OF NEOPLASTIC TRANSFORMATION: A NOVEL TARGET FOR ANTI-CANCER THERAPEUTICS.” TECHNICAL FIELD [0002] The invention relates generally to methods and compositions for the treatment of cancer. The invention also relates to methods and compositions of screening candidate molecules for anticancer activity. BACKGROUND OF THE INVENTION [0003] The Myc transcription factor promotes S-phase cell-cycle entry, induces apoptosis or programmed cell-death, and causes neoplastic cellular transformation. Expression of the c-Myc oncogene is deregulated in many solid tumors and hematological malignancies, including Adult T-cell Leukemia/Lymphoma, Diffuse Large-Cell Lymphomas (DLCL), Anaplastic CD30+ Large-Cell Lymphomas, and Burkitt's B-cell Lymphomas (a prominent AIDS-related malignancy). Myc is also deregulated in certain solid tumors containing the Myc gene locus mutations. The transforming viruses, human T-cell lymphotropic virus type-1 (HTLV-1) and Epstein Barr virus (EBV), deregulate Myc functions associated with development of ATLL and Burkitt's lymphomas, respectively. [0004] HTLV-1 infects CD4 + T-cells and causes Adult T-cell Leukemia/Lymphoma (ATLL), an aggressive lymphoproliferative disease that is often fatal. HTLV-1-infected leukemic lymphocytes exhibit deregulated cell-cycle progression and characteristic multi-nucleation or polyploidy (evidenced by the appearance of ‘flower-shaped’ or lobulated nuclei). A conserved sequence, known as pX, located within the 3′ terminus of the HTLV-1 genome encodes at least five non-structural regulatory factors, including the viral trans-activator, Tax, and an alternative splice-variant, p30 II (or Tax-ORF II, Tof), which possesses a functional trans-activation domain. The pX sequence is generally retained in the majority of ATLL patient isolates -even those containing partially-deleted proviruses, indicative of its importance for pathogenesis. [0005] The viral Tax protein transcriptionally activates numerous lymphoproliferative pathways (NF-κB, CREB/ATF, and p67 SRF ) and has been shown to inhibit transcription functions associated with the tumor suppressor p53 which likely contributes to a loss of G1/S-phase checkpoint control in HTLV-1-infected T-cells. Many of the pleiotropic effects of Tax upon cellular-signaling may derive from its aberrant recruitment of the transcriptional coactivators, p300/CREB-binding protein (p300/CBP) and p300/CBP-associated factor (P/CAF). Further, Tax interacts with cell-cycle modulators, including D-type cylin-cdk4/6 complexes, retinoblastoma (Rb) protein, and the human mitotic arrest-deficiency-1 (hMAD-1) protein. Although HTLV-1 Tax expression markedly promotes G1/S transition, Tax inhibits Myc-dependent trans-activation and prevents Myc-associated anchorage-independent cell-growth. Since ATLL patient-derived lymphocytes and tumors from HTLV-1 pX transgenic mice are known to possess deregulated Myc functions, other pX-encoded factors may influence Myc to promote cellular transformation by HTLV-1. [0006] Preliminary studies indicate that the HTLV-1 accessory protein p30 II markedly increases S-phase cell-cycle progression and induces significant polyploidy. As relatively little is known with respect to the roles of pX-encoded accessory factors (e.g., p30 II , p13 II , p12 I , Rex p27 ) in HTLV-1-associated pathogenesis, the molecular mechanism by which p30 II promotes Myc-dependent S-phase progression and multi-nucleation was sought. While others have proposed that HTLV-1 p30 II 's functions are targeted against the viral LTR to repress HTLV-1 gene expression, it remains unclear whether these observations reflect the physiological role of p30 II . Nicot et al. (2004, Nat. Med. 10:197-201) and Younis et al. (2004, J. Virol. 78:11077-11083) have shown that p30 II , binds and inhibits nuclear export of the doubly-spliced Tax/Rex HTLV-1 mRNA, and it is intriguing that p30 II , might perform diverse functions to regulate viral gene expression and promote altered cellular growth—as noted for Tax which drives LTR trans-activation and deregulates host lymphoproliferative-signaling pathways. Robek et al. (1998, J. Virol. 72:4458-4462) have previously demonstrated that p30 II is dispensable for immortalization and transformation of human PBMCs by an infectious HTLV-1 molecular clone, ACH.p30 II , defective for p30 II production. However, the ACH.p30 II mutant exhibited an approx 20-50% reduction in transformation-efficiency compared to the wild-type ACH.wt suggesting that p30 II is required for the full transforming-potential of HTLV-1. SUMMARY OF THE INVENTION [0007] The present invention demonstrates that aberrant interactions between Myc (Accession No. 0907235A) and the histone acetyl transferase Tat interactive protein 60 kD (TIP60) (Accession No. U74667.1) drastically enhance the transforming potential of Myc. In some embodiments of the invention, interaction of Myc and TIP60 may be stabilized through interactions with factors associated with oncogenic viruses such as the HTLV-1 p30 II protein (Accession No. AAB23361.1). For example, without being limited to any particular mechanism of action, HTLV-1 p30 II may (a) recruit the transcriptional coactivator TIP60 to Myc-containing chromatin remodeling complexes assembled on conserved E-box (CACGAG) enhancer elements within promoters of Myc-responsive genes, (b) transcriptionally activate the human cyclin D2 promoter, (c) increase S-phase cell-cycle progression and polyploidy (multi-nucleation), and (d) markedly induce colony formation in transformation assays using immortalized human fibroblasts. [0008] A trans-dominant negative TIP60MAT mutant which contains an inactivating-deletion within the histone acetyltransferase (HAT) domain, abrogated foci-formation by HTLV-1 p30 II /Myc and significantly inhibited trans-activation from the human cyclin D2 promoter. These data indicate that aberrant Myc-TIP60 protein interactions prominently contribute to Myc-dependent neoplastic transformation and transcriptional activity, and further suggest that disruption of Myc-TIP60 complexes and inhibition of Myc-TIP60 complex formation are plausible approaches to impede malignancy in anti-cancer therapies. [0009] Thus, the present invention provides aberrant Myc-TIP60 interactions as a molecular target for the development of anti-cancer therapies. These therapies may impede malignancy or slow tumor progression. The present invention also provides screening methods for the identification of anti-cancer therapeutics that block, inhibit, weaken, or otherwise interfere with interactions between Myc and TIP60. [0010] Without being limited to any particular mode of action, factors encoded by transforming viruses (e.g. EBV, HPV, KSHV) or mutations of Myc may facilitate stabilization of Myc-TIP60 interactions to promote neoplastic cellular transformation. [0011] The present invention also relates to cells that may be used to detect Myc-TIP60 interaction. In some embodiments, these cells comprise: a first nucleic acid including an expression control sequence having at least one E-box enhancer element and a reporter gene, wherein the expression control sequence is operatively linked to the reporter gene; a second nucleic acid including an expression control sequence and a nucleotide sequence encoding human T-cell lymphotropic virus type-1 (HTLV-1) p30 II , wherein the expression control sequence is operatively linked to the nucleotide sequence encoding HTLV-1 p30 II ; and a third nucleic acid including an expression control sequence and a nucleotide sequence encoding human TIP60, wherein the expression control sequence is operatively linked to the nucleotide sequence encoding human TIP60. [0015] In some embodiments, the expression control sequence of the first nucleic acid is selected from the group consisting of a human cyclin D2 promoter and a minimal thymidine kinase promoter. In some embodiments of the invention, the expression control sequence of the second nucleic acid and/or third nucleic acid may be a cytomegalovirus promoter. In some embodiments of the invention, the reporter gene may encode a protein selected from the group consisting of β-galactosidase, β-glucuronidase, autofluorescent proteins, including blue fluorescent protein (BFP) and green fluorescent protein (GFP), glutathione-S-transferase (GST), luciferase, horseradish peroxidase (HRP), and chloramphenicol acetyltransferase (CAT). [0016] The present invention also provides methods of blocking, impeding, or otherwise interfering with the interaction of Myc and TIP60. For example, the invention provides a method of interfering with Myc and TIP60 interaction in a cell, comprising: contacting the cell with a nucleic acid, polypeptide, or organic molecule, wherein the nucleic acid, polypeptide, or organic molecule inhibits Myc-TIP60 interaction. In some embodiments of the invention, the organic molecule is a small molecule drug. The polypeptide may be a protein that comprises a TIP60 ΔHAT protein. Similarly, the nucleic acid may be a nucleic acid that encodes a polypeptide comprising a TIP60 ΔHAT protein. [0017] The invention further provides screening assays to identify one or more molecules that block, impede, or otherwise interfere with neoplastic transformation. For example, the invention provides a method of identifying a molecule that inhibits neoplastic transformation of a cell, comprising: contacting a test cell with a test molecule; measuring the cellular foci formed in the presence of the test molecule; and comparing the number of foci formed in the presence of the test molecule with the number of foci formed by test cell in the absence of the test molecule, wherein formation of fewer foci in the presence of the test molecule than in the absence of the test molecule indicates inhibition of neoplastic transformation, and wherein the test cell comprises: a first nucleic acid comprising an expression control sequence and a nucleotide sequence encoding the Myc transcription factor, wherein the expression control sequence is operatively linked to the reporter gene; a second nucleic acid comprising an expression control sequence and a nucleotide sequence encoding human T-cell lymphotropic virus type-1 (HTLV-1) p30 II , wherein the expression control sequence is operatively linked to the nucleotide sequence encoding HTLV-1 p30 II ; and a third nucleic acid comprising an expression control sequence and a nucleotide sequence encoding human TIP60, wherein the expression control sequence is operatively linked to the nucleotide sequence encoding human TIP60. According to the invention, the expression control sequence of the second nucleic acid and/or third nucleic acid may be a cytomegalovirus promoter. [0024] The invention also provides methods for identifying one or more molecules that block, impede, or otherwise interfere with Myc-TIP60 interactions. The invention provides, for example, a method of identifying a molecule that interferes with Myc-TIP60 interaction, comprising: contacting a test cell with a test molecule wherein the test cell comprises: a first nucleic acid comprising an expression control sequence comprising at least one E-box enhancer element and a reporter gene, wherein the expression control sequence is operatively linked to the reporter gene; a second nucleic acid comprising an expression control sequence and a nucleotide sequence encoding human T-cell lymphotropic virus type-1 (HTLV-1) p30 II wherein the expression control sequence is operatively linked to the nucleotide sequence encoding HTLV-1 p30 II ; and a third nucleic acid comprising an expression control sequence and a nucleotide sequence encoding human TIP60, wherein the expression control sequence is operatively linked to the nucleotide sequence encoding human TIP60; detecting the reporter gene expression in the presence of the test molecule; and comparing the reporter gene expression in the presence of the test molecule with reporter gene expression in the absence of the test molecule, wherein reduced reporter gene expression in the presence of the test molecule relative to reporter gene expression in the absence of the test molecule indicates inhibition of Myc-TIP60 interaction. [0031] According to the invention, the expression control sequence of the first nucleic acid may be selected from the group consisting of a human cyclin D2 promoter and a minimal thymidine kinase promoter. In addition, the expression control sequence of the second nucleic acid and/or third nucleic acid may be a cytomegalovirus promoter. In some embodiments of the invention, the reporter gene may encode a protein selected from the group consisting of β-galactosidase, β-glucuronidase, autofluorescent proteins, including blue fluorescent protein (BFP) and green fluorescent protein (GFP), glutathione-S-transferase (GST), luciferase, horseradish peroxidase (HRP), and chloramphenicol acetyltransferase (CAT). [0032] In some embodiments the invention provides a method of detecting cancer in a test tissue sample, comprising: detecting Myc-TIP60 complexes in the test tissue sample; and comparing the Myc-TIP60 complexes in the tissue sample with Myc-TIP60 complexes in a corresponding non-cancerous tissue, wherein an elevated level of Myc-TIP60 complexes in the test tissue sample relative to the non-cancerous tissue indicates the presence of cancer. The method of detecting complex formation may be accomplished by any means of detection protein-protein interactions known in the art. For example, detection may be achieved by lysing cells of the test tissue sample, forming a clear extract, and immunoprecipitating Myc-interacting complexes with an anti-HA tag antibody. The test tissue sample may be derived from any source including, without limitation, tissue biopsies. BRIEF DESCRIPTION OF THE DRAWINGS [0035] The patent application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the United States Patent and Trademark Office upon request and payment of the necessary fee. [0036] A more complete and thorough understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein: [0037] FIG. 1A is a diagram of the HTLV-1 proviral genome and its translation products with the the viral transcription factors, Tax and p30 II , are in bold; [0038] FIG. 1B illustrates a RasMol structural prediction of the HTLV-1 p30 II protein in which sub-domains (4 alpha-helices; 19 beta-sheets) are represented by different colors and Connelly/Richards (1.2 Å) radii are indicated in white; [0039] FIG. 1C , left panel illustrates a plot of DNA content (assayed by 7-AAD) versus DNA synthesis (S-phase; assayed by BrdU content) for Molt-4 lymphocytes that were transfected with an empty CβS vector control (3.0 μg); [0040] FIG. 1C , right panel illustrates a fluorescent activated cell sorting (FACS) analysis of the percentages of apoptotic cells in cultures of CβS-transfected Molt-4 lymphocytes stained with annexin-V-(FITC)/propidium iodide; [0041] FIG. 1D illustrates flow cytometry results using Molt-4 lymphocytes that were transfected with an empty CβS vector control (3.0 μg) [0042] Table 1 shows the relative percentages of CβS-transfected Molt-4 lymphocytes in various stages of the cell-cycle as quantified using aneuploid analysis software (ModFit LT 3.0); [0043] FIG. 1E , left panel illustrates a plot of DNA content (assayed by 7-AAD) versus DNA synthesis (S-phase; assayed by BrdU content) for Molt-4 lymphocytes that were transfected with CMV-HTLV-1 p30 II (HA) (3.0 μg); [0044] FIG. 1E , right panel illustrates a fluorescent activated cell sorting (FACS) analysis of the percentages of apoptotic cells in cultures of CMV-HTLV-1 p30 II -transfected Molt-4 lymphocytes stained with annexin-V-(FITC)/propidium iodide; [0045] FIG. 1F illustrates flow cytometry results using Molt-4 lymphocytes that were transfected with CMV-HTLV-1 p30 II (HA) (3.0 μg); [0046] Table 2 shows the relative percentages of CMV-HTLV-1 p30 II -transfected Molt-4 lymphocytes in various stages of the cell-cycle as quantified using aneuploid analysis software (ModFit LT 3.0); [0047] FIG. 2A illustrates the results of immunofluorescence-laser confocal microscopy performed on HTLV-1-infected ATLL patient-derived T-cells (ATL-1, ATL-2, ATL-3) or Jurkat E6.1 lymphocytes as a negative control, using a monoclonal anti-Myc antibody (blue, left panels) or a rabbit polyclonal anti-HTLV-1 p30 II antibody (green, left-middle panels), merged images of the Myc and HTLV-1 p30 II localization (right-middle panels), and merged images with viewed with phase contrast optics; [0048] FIG. 2B illustrates a three-dimensional Z-stack composite for ATL-3 with three rotational views of merged images (demonstrating nuclear co-localization of HTLV-1 p30 II (green)/Myc (blue) in all focal planes) and a graphical representation of relative fluorescence-intensities for HTLV-1 p30 II /Myc-specific signals and DAPI nuclear-staining for reference; [0049] FIG. 2C illustrates a co-immunoprecipitations performed using extracts prepared from HTLV-1-infected ATLL patient-derived lymphocytes and anti-Myc or anti-HTLV-1 p30 II antibodies; [0050] FIG. 2D , upper panel illustrates the results of co-immunoprecipitation assays of Jurkat E6.1, HuT-102, and MJ[G11] lymphocytes transfected with an empty CβS vector control or CMV-HTLV-1 p30 II (HA) using a monoclonal anti-HA tag antibody (CA5, Roche Molecular Biochemicals); [0051] FIG. 2D , lower panel illustrates the results of co-immunoprecipitation assays of Jurkat E6.1 whole-cell extracts using antibodies against known. RNA Polymerase II and TIP48 binding partners (anti-p300; anti-Myc) with an anti-HTLV-1 Tax monoclonal antibody (20) was used as a negative control; [0052] FIG. 2E illustrates the results of co-immunoprecipitation assays of Jurkat E6.1, HuT-102, and MJ[G11] lymphocytes transfected with an empty CβS vector control or CMV-HTLV-1 p30 II (HA) using a monoclonal anti-HA tag antibody (CA5, Roche Molecular Biochemicals) in which HTLV-1 p30 II -interacting proteins were detected by immunoblotting; [0053] FIG. 3A shows a bar graph with the results of luciferase assays of HeLa cells co-transfected with a human cyclin D2 promoter-luciferase reporter plasmid and increasing amounts of CMV-HTLV-1 p30 II (HA) and, in the lower panel, the expression of HTLV-1 p30 II (HA), Myc, and Actin in transfected cells; [0054] FIG. 3B shows a bar graph with the results of luciferase assays of HeLa cells co-transfected as in FIG. 3A , lacking conserved Myc-responsive E-box enhancer elements, and increasing amounts of CMV-HTLV-1 p30 II (HA); [0055] FIG. 3C shows a bar graph with the results of luciferase assays of 293A Fibroblasts co-transfected as in FIG. 3A with a human cyclin D2 promoter-luciferase reporter plasmid and increasing amounts of CMV-HTLV-1 p30 II (HA) and, in the lower panel, the expression of HTLV-1 p30 II (HA), Myc, and Actin in transfected cells detected by immunoblotting; [0056] FIG. 3D shows a bar graph with the results of luciferase assays of 293A Fibroblasts co-transfected as in FIG. 3A with a synthetic, E-box-containing minimal tk promoter-luciferase reporter construct (M4-tk-luc) and increasing amounts of CMV-HTLV-1 p30 II (HA) (error bars representing standard deviations are provided); [0057] FIG. 4A shows a bar graph with the results of luciferase assays of HeLa cells were co-transfected with a human cyclin D2 promoter-luciferase reporter plasmid (0.5 kg) and CMV-HTLV-1 p30 II (HA) (0.15 kg) in the presence of increasing amounts of CMV-wild-type TIP60, CMV-TIP60 ΔHAT , or CMV-TIP60 L497A and, in the lower panel, the expression of HTLV-1 p30 II (HA) and Actin detected by immunoblotting (lower panels); [0058] FIG. 4B shows a bar graph with the results of luciferase assays of HeLa cells co-transfected as in FIG. 4A with a human cyclin D2 promoter-luciferase plasmid and CMV-HTLV-1 p30 II (HA) in the presence of increasing amounts of CβS-TRRAP anti-sense or CβF-TRRAP 1261-1579 and, in the lower panel, the expression of the trans-dominant negative TRRAP 12611-1579 -(FLAG) mutant, HTLV-1 p30 II (HA), Myc, and Actin proteins detected by immunoblotting using an anti-FLAG M2 monoclonal antibody (SIGMA Chemical Corp.), anti-HA (CA5) or anti-Myc monoclonal antibodies, or anti-Actin goat polyclonal antibody (error bars representing standard deviations are provided).; [0059] FIG. 4C illustrates over-expression of the (FLAG)-TIP60 (wild-type) and (FLAG)-TIP60 ΔHAT proteins (23) relative to endogenous TIP60 as visualized by immunofluorescence-microscopy using a rabbit polyclonal anti-TIP60 antibody (top panels) and an anti-FLAG M2 monoclonal antibody (bottom panels) with the CβS empty vector transfected as a negative control; [0060] FIG. 5A illustrates the results of chromatin-immunoprecipitation assays performed on uninfected Molt-4 lymphocytes using antibodies that recognize various Myc-interacting factors (TIP60, TRRAP, TIP48, TIP49, hGCN5; upper panel) or acetylated forms of histone H3 (Acetyl-K9, Acetyl-K14; lower panel); [0061] FIG. 5B illustrates the results of chromatin-immunoprecipitation assays performed on HTLV-1-infected MJ[G11] lymphocytes using antibodies that recognize various Myc-interacting factors (TIP60, TRRAP, TIP48, TIP49, hGCN5; upper panel) or acetylated forms of histone H3 (Acetyl-K9, Acetyl-K14; lower panel); [0062] FIG. 5C illustrates the results of chromatin-immunoprecipitation assays performed on HTLV-1-infected HuT-102 lymphocytes using antibodies that recognize various Myc-interacting factors (TIP60, TRRAP, TIP48, TIP49, hGCN5; upper panel) or acetylated forms of histone H3 (Acetyl-K9, Acetyl-K14; lower panel); [0063] FIG. 5D shows a diagram of GST-HTLV-1 p30 II fusion proteins and relative input levels of GST-HTLV-1 p30 II and GST-p30 II truncation mutants, Myc, and TIP60 proteins; [0064] FIG. 5E shows the input for GST-pull-down experiments using HeLa extracts and purified recombinant GST-HTLV-1 p30 II or GST-p30 II (1-98), GST-p30 II (99-154), and GST-p30 II (155-241) truncated mutant proteins; [0065] FIG. 5F shows the results from GST-pull-down experiments using HeLa extracts and purified recombinant GST-HTLV-1 p30 II or GST-p30 II (1-98), GST-p30 II (99-154), and GST-p30 II (155-241) truncated mutant proteins; [0066] FIG. 5G illustrates the results of ChIP analyses of HTLV-1 p30 II -Myc/TIP60 transcription complexes recruited to Myc-responsive E-box elements within the genomic cyclin D2 promoter in cultured HTLV-1-infected ATLL patient (ATL-1) lymphocytes in which PCR analyses of ChIP products were carried-out using PRM and UTR oligonucleotide primer pairs; [0067] FIG. 6A illustrates expression of HTLV-1 p30 II -GFP in transfected 293A fibroblasts visualized by fluorescence-microscopy; [0068] FIG. 6B shows the results of ChIP analyses performed on 293A fibroblasts transfected with HTLV-1 p30 II -GFP using various antibodies against specific Myc-interacting proteins; [0069] FIG. 6C illustrates expression of GFP in 293A fibroblasts transfected with a pcDNA3.1-GFP control and visualized by fluorescence-microscopy; [0070] FIG. 6D shows the results of ChIP analyses performed on 293A fibroblasts transfected with a pcDNA3.1-GFP control using various antibodies against specific Myc-interacting proteins; [0071] FIG. 6E shows the results of luciferase assays in which 293A Fibroblasts were co-transfected with a human cyclin D2 promoter-luciferase reporter construct, CMV-HTLV-1 HTLV-1 p30 II -GFP, and increasing amounts of CMV-TIP60 (wild-type) or CMV-TIP60 ΔHAT (error bars represent of standard deviations from duplicate experiments); [0072] FIG. 6F shows the results of luciferase assays in which 293A Fibroblasts were co-transfected with a tk-promoter-renilla-luciferase reporter construct, CMV-HTLV-1 HTLV-1 p30 II -GFP, and increasing amounts of CMV-TIP60 (wild-type) or CMV-TIP60 ΔHAT (error bars represent of standard deviations from duplicate experiments); [0073] FIG. 7A shows a graphical illustration of microarray gene expression analyses performed on 293A fibroblasts transfected with a CβS empty vector control or CMV-HTLV-1 p30 II (HA) using Affymetrix Human U133Plus 2.0 full-genomic chips in which transcriptional activation of cellular genes by HTLV-1 p30 II is expressed as Fold Activation relative to the empty CβS vector control; [0074] FIG. 7B shows a graphical illustration of microarray gene expression analyses performed on 293A fibroblasts transfected with a CβS empty vector control, CMV-HTLV-1 p30 II (HA), or CMV-HTLV-1 p30 II (HA) +CMV-TIP60 ΔHAT using Affymetrix Human U133Plus 2.0 full-genomic chips in which transcriptional activation of cellular genes by HTLV-1 p30 II is expressed as Fold Activation relative to the empty CβS vector control and TIP60-dependent genes are identified based upon their transcriptional repression in the presence of the trans-dominant-negative TIP60 ΔHAT mutant; [0075] FIG. 7C shows a graphical illustration of microarray gene expression analyses performed on 293A fibroblasts transfected with a CβS empty vector control or CMV-HTLV-1 p30 II (HA) using Affymetrix Human U133Plus 2.0 full-genomic chips in which transcriptional repression of cellular genes by HTLV-1 p30 II is expressed as Fold Repression relative to the empty CβS vector control; [0076] FIG. 7D shows a graphical illustration of microarray gene expression analyses performed on 293A fibroblasts transfected with a CβS empty vector control, CMV-HTLV-1 p30 II (HA), or CMV-HTLV-1 p30 II (HA) +CMV-TIP60 ΔHAT using Affymetrix Human U133Plus 2.0 full-genomic chips in which transcriptional repression of cellular genes by HTLV-1 p30 II is expressed as Fold Repression relative to the empty CβS vector control and TIP60-dependent or TIP60-independent genes are identified based upon their transcriptional repression in the presence of the trans-dominant-negative TIP60 ΔHAT mutant; [0077] FIG. 8A illustrates representative results from triplicate foci-formation assays using immortalized human WR −/− fibroblasts transfected with CβS empty vector (3.0 μg), CMV-HTLV-1 p30 II (HA) (3.0 μg), CβF-FLAG-Myc (3.0 μg), and combinations of CβS (1.5 μg)/CβF-FLAG-Myc (3.0 μg) or CMV-HTLV-1 p30 II (HA) (1.5 μg)/CβF-FLAG-Myc (3.0 μg); [0078] FIG. 8B is a bar graph of the results shown in FIG. 8A ; [0079] FIG. 8C shows micrographs of CβS/CβF-FLAG-Myc-transfected (upper panels) or CMV-HTLV-1 p30 II (HA)/CβF-FLAG-Myc-transfected (lower panels) immortalized human WRN −/− fibroblasts viewed with phase contrast optics (left panels) or after staining with DAPI (middle panels) or a monoclonal anti-HA tag antibody and a rhodamine red-conjugated anti-mouse secondary antibody (right panels) [0080] FIG. 8D shows HTLV-1 p30 II (HA)/Myc-transformed fibroblasts stained with DAPI (left panel) and a monoclonal anti-HA tag antibody and a rhodamine red-conjugated anti-mouse secondary antibody viewed in the blue channel (left panel), red channel (center panel), and both the blue and red channels (right panel); [0081] FIG. 8E shows an increased number of multi-nucleated giant cells observed in isolated HTLV-1 p30 II (HA)/Myc-transformed WRN −/− fibroblasts expanded in culture (arrows, micrograph) and expression of HTLV-1 p30 II (HA) detected by immunoblotting using a monoclonal anti-HA antibody (lower panel); [0082] FIG. 9A shows the results of a first foci-formation/transformation assay using immortalized human WRN −/− fibroblasts transfected with CβF-FLAG-Myc (3.0 μg) and either CMV-HTLV-1 p30 II (HA) or empty CβS vector control (1.5 μg) in the presence of CMV-TIP60, CMV-TIP60 ΔHAT , or CMV-TIP60 L497A (3.0 μg) [0083] FIG. 9B shows the results of a second foci-formation/transformation assay using immortalized human WRN −/− fibroblasts transfected with CβF-FLAG-Myc (3.0 μg) and either CMV-HTLV-1 p30 II (HA) or empty CβS vector control (1.5 μg) in the presence of CMV-TIP60, CMV-TIP60 ΔHAT , or CMV-TIP60 L497A (3.0 μg); [0084] FIG. 9C shows that over-expression of wild-type TIP60 results in increased foci-formation in WRN −/− fibroblasts co-transfected with CMV-HTLV-1 p30 II (HA), CβF-FLAG-Myc, and CMV-TIP60; [0085] FIG. 9D shows that co-expression of the trans-dominant-negative TIP60 ΔHAT mutant in the cells of FIG. 9 C inhibits cellular transformation by HTLV-1 p30 II (HA)/Myc; [0086] FIG. 9E shows representative results from duplicate foci-formation/transformation assays using immortalized human WRN −/− fibroblasts transfected as in FIGS. 9A and 9B in the presence of increasing amounts of CβS-TRRAP anti-sense or CβS empty vector (0.5, 1.5, 3.0 μg) with an asterisk denoting HTLV-1 p30 II (HA)/Myc foci-formation; and [0087] FIG. 10 illustrates a model of HTLV-1 p30 II modulatory interactions with Myc-TIP60 transcription complexes assembled on E-box enhancer elements within promoters of Myc-responsive genes (nucleosomal acetylation associated with transcriptional activation indicated). DETAILED DESCRIPTION OF THE INVENTION [0088] HTLV-1 p30 II increases S-phase progression and promotes polyploidy. The conserved pX domain of HTLV-1 encodes at least five non-structural regulatory factors, including the viral trans-activator, Tax, and an alternative splice-variant, p30 II ( FIG. 1A ). The HTLV-1 p30 II protein is comprised of 241 amino acid residues and contains Arg- and Ser/Thr-rich domains. RasMol structural prediction analyses (Brookhaven protein databank) indicate that p30 II possesses four alpha-helices and nineteen beta-sheet regions ( FIG. 1B ). The alpha-helices likely serve as interacting or docking sites for cellular factors, whereas the Ser/Thr-rich domains may provide targets for phosphorylation by kinases that modulate p30 II 's functions or interactions. As relatively little is known with respect to the functions of HTLV-1 pX accessory factors, such as p30 II , the issue of whether the p30 II protein contributes to lymphoproliferation in HTLV-1-infected T-cells by altering cell-cycle regulation was investigated. [0089] To determine whether HTLV-1 p30 II influences cell-cycle progression and/or apoptosis, Molt-4 and Jurkat E6.1 lymphocytes were transfected with a CMV-HTLV-1 p30 II (HA) expression construct or an empty CβS vector control. Transfected cultures were assayed for bromodeoxyuridine (BrdU)-incorporation/cell-cycle progression or programmed cell-death using flow-cytometric analyses ( FIGS. 1C to 1 F and Tables 1-2). HTLV-1 p30 II -expressing cells exhibited markedly increased S-phase progression and significant polyploidy, as determined by BrdU-incorporation and 7-AAD-staining of total genomic DNA ( FIGS. 1C and 1E , left panels, FIGS. 1D and 1F and Tables 1-2). However, p30 II did not induce apoptosis in transfected cells as determined by annexin-V-FITC/propidium iodide-staining and FACS ( FIGS. 1C and 1E , right panels). These results suggest that p30 II may contribute to lymphoproliferation and genomic instability in HTLV-1-infected cells during ATLL by affecting S-phase regulatory factors, such as Myc and/or E2F. TABLE 1 Diploid: 99.68% Dip G1: 60.50% at 58.18 Dip G2:  2.85% at 116.37 Dip S: 36.65% G2/G1: 2.00 % CV:   9.72 Aneuploid 1:  0.32% An1 G1: 66.73% at 67.97 An1 G2:  0.00% at 147.34 An1 S: 32.27% G2/G1: 2.17 % CV: 1.32 DI: 1.17 Total Aneuploid S-Phase: 33.27% Total S-Phase: 36.64% Total B.A.D.: 23.45% Debris: 29.64% Aggregates:  7.68% Modeled events: 23210 All cycle events: 14547 Cycle events per channel:  161 RCS:   3.365 [0090] TABLE 2 Diploid: 65.58% Dip G1: 98.05% at 85.10 Dip G2:  0.17% at 170.20 Dip S:  1.79% G2/G1: 2.00 % CV:   8.05 Aneuploid 1: 34.42% An1 G1: 11.34% at 99.15 An1 G2: 11.09% at 174.33 An1 S: 77.57% G2/G1: 1.76 % CV: 4.05 DI: 1.17 Total Aneuploid S-Phase: 77.57% Total S-Phase: 27.87% Total B.A.D.: 28.92% Debris: 41.67% Aggregates:  6.66% Modeled events: 22920 All cycle events: 11843 Cycle events per channel:  131 RCS:   3.211 [0091] The HTLV-1 p30 II protein interacts in Myc-TIP60 immune-complexes in ATLL patient lymphocytes. The p30 II protein was detected in cultured HTLV-1-infected lymphocytes, derived from three different ATLL patients (ATL-1, ATL-2, ATL-3) diagnosed with clinical acute-stage leukemias, by immunofluorescence-laser confocal microscopy ( FIGS. 2A and 2B ) and immuno-blotting ( FIG. 2C ). Three-dimensional Z-stack composite images of ATL-3 demonstrate that p30 II /Myc proteins co-localize in the nucleus in all focal planes in HTLV-1-infected cells ( FIG. 2A ). Relative fluorescence-intensities for p30 II /Myc-specific signals and DAPI nuclear-staining are shown for reference ( FIG. 2B ). HTLV-1 p30 II is present in Myc-containing immunoprecipitated complexes in ATLL patient lymphocytes ( FIG. 2C ). Intriguingly, immunoprecipitation of Myc revealed that TIP49 (RUVBL1), TIP48 (RUVBL2), and Max are present bound to Myc, but the TIP60 histone acetyltransferase (HAT) was not detected in Myc-containing co-immune complexes in uninfected Jurkat E6.1 lymphocytes ( FIG. 2C ). The NH 2 -terminus of Myc is essential for Myc-dependent transformation and apoptosis-inducing functions and contains two conserved Myc homology domains (Myc boxes I and II, MBI and MBII, respectively) that interact with cellular factors. The transcriptional coactivator, TRRAP/p434, and the ATPases/helicases, TIP 49 (RUVBL1) and TIP 48 (RUVBL2), interact with amino acids within MBII. To determine if HTLV-1 p30 II interacts with known Myc-binding partners, Jurkat E6.1 lymphocytes or HTLV-1-infected Hut-102 and MJ[G11] lymphocytes were transfected with CMV-HTLV-1 p30 II (HA) or an empty CβS vector control and co-immunoprecipitations using a monoclonal anti-HA antibody were performed (CA5, Roche Molecular Diagnostics). As shown in FIGS. 2D and 2E , HTLV-1 p30 II (HA) immunoprecipitates with Myc, TRRAP, TIP60, and TIP49 (RUVBL1). However, TIP48 (RUVBL2) and RNA Pol II were not detected in anti-HA immunoprecipitates, although both proteins were detected in control immunoprecipitations using antibodies against known interacting proteins ( FIG. 2D , lower panels). These data suggest that HTLV-1 p30 II may modulate Myc functions through interactions with Myc-associated transcriptional coactivators on promoters of responsive genes. [0092] HTLV-1 p30 II trans-activates Myc-responsive E-box elements within the human cyclin D2 promoter. To investigate the possibility that HTLV-1 p30 II might affect Myc-dependent transcription, HeLa cells were co-transfected with a human cyclin D2 promoter-luciferase reporter construct, containing two conserved Myc-responsive E-box enhancer elements (CACGTG), in the presence of increasing amounts of CMV-HTLV-1 p30 II (HA). Results shown in FIG. 3A demonstrate that HTLV-1 p30 II significantly trans-activates the human cyclin D2 promoter in a dose-dependent manner. A mutant cyclin D2 promoter, lacking Myc-responsive E-box elements, was not transcriptionally activated by p30 II indicating that p30 II -mediated trans-activation from the human cyclin D2 promoter requires the conserved Myc-responsive E-box enhancer elements ( FIGS. 3A and 3B ). The HTLV-1 p30 II (HA)-tagged protein was detected in transfected cells by immunoblotting using a monoclonal anti-HA antibody (CA5. Roche Molecular Biochemicals) ( FIG. 3A ). Intracellular levels of Myc were not altered by HTLV-1 p30 II expression ( FIG. 3A , lower panels). HTLV-1 p30 II also transcriptionally activates the human cyclin D2 promoter in transfected 293A fibroblasts in a dose-dependent manner ( FIG. 3C ). To confirm that HTLV-1 p30 II promotes Myc-dependent transcription from E-box enhancer elements, 293A fibroblasts and HeLa cells were co-transfected with a synthetic tk minimal promoter-luciferase reporter construct (M4-tk-luc) that contains four tandem E-boxes. As shown in FIG. 3D , HTLV-1 p30 II trans-activates E-box enhancer elements within M4-tk-luc suggesting that p30 II promotes S-phase progression through Myc-dependent transcriptional interactions. [0093] Interestingly, p30 II , at the lowest concentration used, induced approx 13-fold trans-activation from the synthetic M4-tk-luc promoter, whereas higher concentrations induced lower (5 to 7-fold) levels of transcriptional activation ( FIG. 3D ). These observations are consistent with findings by Zhang et al. (2000, J. Virol. 74:11270-11277) demonstrating that p30 II -dependent trans-activation from the HTLV-1 promoter (Tax-responsive elements, TREs) maximally occurs at low p30 II concentrations and diminishes with increased p30 II expression. [0094] Transcriptional activation by HTLV-1 p30 II is dependent upon the TIP60 and TRRAP/p434 coactivators. Since Myc may interact with the transcriptional coactivator/HAT, TIP60, c-Myc may be a substrate for lysine-acetylation by TIP60, and Myc may interact in chromatin-remodeling complexes with the ATM-related TRRAP/p434 protein, tests were performed to determine whether HTLV-1 p30 II -mediated trans-activation requires TIP60 and TRRAP/p434 functions. HeLa cells were co-transfected with a human cyclin D2 promoter-luciferase reporter construct and CMV-HTLV-1 p30 II (HA) in the presence of increasing amounts of CMV-TIP60, CMV-TIP60 ΔHAT (a trans-dominant negative HAT-inactive mutant), or CMV-TIP 60 L497A —a carboxyl-terminal mutant impaired for interactions with cellular factors, including the androgen receptor. Ectopic expression of TIP60 alone did not significantly trans-activate the human cyclin D2 promoter, however, TIP60 over-expression enhanced HTLV-1 p30 II -mediated trans-activation in a dose-dependent manner ( FIG. 4A ). The trans-dominant negative TIP60 ΔHAT mutant potently inhibited p30 II -mediated transcriptional activation ( FIG. 4A ), suggesting that HTLV-1 p30 II trans-activation requires TIP60-associated HAT activity. The TIP60 L497A mutant also weakly enhanced p30 II -mediated trans-activation ( FIG. 4A ). Over-expression of wild-type TIP60 or the trans-dominant-negative TIP 60 ΔHAT mutant did not alter expression of the HTLV-1 p30 II (HA) protein in transfected HeLa cells ( FIG. 4A , lower panels). Inhibition of TRRAP/p434, as a result of co-expressing either TRRAP anti-sense RNA or a trans-dominant negative TRRAP mutant, TRRAP 1261-1579 (FLAG-epitope-tagged), prevented HTLV-1 p30 II -mediated transcriptional activation from the human cyclin D2 promoter ( FIG. 4B ). The trans-dominant-negative, FLAG-tagged TRRAP 1261-1579 protein did not alter the expression of HTLV-1 p30 II (HA) ( FIG. 4B , lower panels). Immunofluorescence-microscopy was then performed, using a monoclonal anti-FLAG M2 antibody (Sigma Chemical Corp.) and a rabbit polyclonal anti-TIP60 antibody (Upstate Biotechnology), to visualize expression of the FLAG-tagged wild-type TIP60 or TIP60 ΔHAT proteins relative to endogenous TIP60. Results in shown FIG. 4C demonstrate that the FLAG-tagged TIP60 proteins were drastically over-expressed relative to endogenous TIP60 in transfected cells. These data collectively indicate that HTLV-1 p30 II synergizes with the TIP60 HAT to trans-activate Myc-responsive E-box elements within the human cyclin D2 promoter, requiring the transcriptional coactivator TRRAP/p434. [0095] HTLV-1 p30 II stabilizes Myc/TIP60 chromatin-remodeling transcription complexes in HTLV-1-infected lymphocytes. Since HTLV-1 p30 II transcriptionally activates the conserved Myc-responsive E-box enhancer elements within the human cyclin D2 promoter ( FIGS. 3A and 3C ), a chromatin-immunoprecipitation (ChIP) procedure (described in Vervoorts et al., 2003, EMBO Rep. 4:484-490) was used to determine whether p30 II is present in Myc-containing chromatin-remodeling complexes. Formaldehyde-cross-linked genomic DNA complexes in uninfected Molt-4 lymphocytes or HTLV-1-infected MJ[G11] and HuT-102 lymphocytes were fragmented by sonication and oligonucleosomal-protein complexes were precipitated using antibodies against candidate Myc-binding factors. Cross-links were reversed and specific oligonucleotide DNA primer pairs were used in PCR reactions to amplify immunoprecipitated DNA regions spanning conserved E-box elements (PRM) or an untranslated sequence (UTR) as negative control. Results shown in FIGS. 5A to 5 C (top panels) demonstrate that HTLV-1 p30 II was only detected bound to E-box enhancer elements in HTLV-1-infected lymphocytes. Myc, TRRAP, TIP49 (RUVBL1), TIP48 (RUVBL2), and the acetyltransferase hGCN5 were present in chromatin-remodeling complexes in uninfected Molt-4 cells and in HTLV-1-infected MJ[G11] and HuT-102 lymphocytes ( FIGS. 5A to 5 C, top panels). Surprisingly, TIP60 was only detected in Myc-containing transcription complexes that contained p30 II in HTLV-1-infected T-cells ( FIGS. 5A to 5 C, top panels), consistent with co-immunoprecipitation results and observed effects of ectopic TIP60 in trans-activation assays (see FIGS. 2B , 4 A). The diminished recruitment of TIP49 to Myc-containing transcription complexes on the cyclin D2 promoter in HTLV-1-infected MJ[G11] cells was not attributable to apparent differences in p30 II /Myc/TIP60 interactions ( FIG. 5A ). Histone H3-acetylation surrounding the E-box enhancer elements within the human cyclin D2 promoter, consistent with transcriptional activation, was detected in all cell-types, with the exception that H3 appeared to be differentially-acetylated on Lys-9 and Lys-14 residues in HTLV-1-infected MJ[G11] and HuT-102 cells, respectively ( FIG. 5A , lower panels). Differences in histone H3-acetylation, however, did not correlate with the stabilization of p30 II /Myc/TIP60 transcriptional interactions in HTLV-1-infected T-cell-lines. [0096] To identify residues within HTLV-1 p30 II that interact with Myc/TIP60 complexes in vivo, a panel of pGEX 4T.1-glutathione S-transferase (GST)-HTLV-1 p30 II constructs, expressing full-length GST-HTLV-1 p30 II or various truncation mutants, GST-p30 II (residues 1-98), GST-p30 II (residues 99-154), GST-p30 II (residues 155-241) spanning the entire coding region of HTLV-1 p30 II were generated ( FIG. 5D , see diagram). These proteins were expressed in E. coli, BL21, bacteria and purified recombinant GST-HTLV-1 p30 II fusion proteins were used in GST-pull-down experiments as described in Harrod et al. (1998, Mol. Cell Biol. 18:5052-5061). GST-proteins were incubated with HeLa nuclear extracts at 4° C. overnight and complexes were precipitated with glutathione-Sepharose 4B (Amersham-Pharmacia Biotech). The matrices were washed and bound factors were eluted using 10 mM reduced glutathione buffer. Input levels of purified recombinant GST or GST-HTLV-1 p30 II proteins, Myc, and TIP60 are shown in FIGS. 5E and 5F . Results in FIG. 5F demonstrate that full-length GST-HTLV-1 p30 II interacts with both Myc and TIP60 in HeLa nuclear extracts. Deletion of amino acid residues from either the NH 2 -terminus or COOH-terminus of p30 II , disrupts Myc-binding, however, the TIP60-interacting region of HTLV-1 p30 II was mapped to residues between positions 99-154 ( FIG. 5B ). [0097] Recruitment of HTLV-1 p30 II /Myc/TIP60 chromatin-remodeling complexes to conserved, Myc-responsive E-box enhancer elements within the cyclin D2 promoter in cultured HTLV-1-infected ATLL patient lymphocytes (ATL-1) was examined next. Chromatin-immunoprecipitations were performed using antibodies that recognize endogenous HTLV-1 p30 II , Myc, and known Myc-interacting factors as described. Polymerase chain-reaction amplification of ChIP products was performed using the PRM and UTR oligonucleotide DNA primer pairs. Results shown in FIG. 5G demonstrate that p30 II is present in Myc/TIP60 transcription complexes assembled on E-box enhancer elements within the cyclin D2 promoter in HTLV-1 ATLL patient lymphocytes. The transcriptional coactivators, TRRAP/p434, TIP48, TIP49, and hGCN5 were also detected in p30 II /Myc/TIP60/cyclin D2 promoter complexes ( FIG. 5G ). [0098] HTLV-1 p30 II -GFP stabilizes Myc/TIP60 interactions and trans-activates the cyclin D2 promoter in a TIP60 HAT-dependent manner. An HTLV-1 p30 II -green fluorescent protein (GFP) that is functionally identical to HTLV-1 p30 II (HA) was used to determine whether HTLV-1 p30 II similarly interacts in Myc/TIP60 transcription complexes in 293A fibroblasts. These cells were co-transfected 293A with CMV-HTLV-1 p30 II -GFP or a pcDNA3.1-GFP vector control and ChIP analyses were performed. Nucleoprotein complexes were cross-linked by treatment with formaldehyde and oligonucleosomal fragments were generated by brief sonication of extracted genomic DNA. Chromatin-immunoprecipitations were performed as described and ChIP products were amplified by PCR using the PRM and UTR oligonucleotide DNA primer pairs. Similar expression of HTLV-1 p30 II -GFP and GFP proteins was visualized in transfected 293A fibroblasts by fluorescence-microscopy ( FIGS. 6A and 6C ). The HTLV-1 p30 II -GFP protein was immunoprecipitated, bound to Myc-containing transcription complexes on conserved E-box elements within the cyclin D2 promoter in transfected 293A fibroblasts, using an anti-GFP antibody ( FIG. 6B ). No ChIP product was detected for the anti-GFP immunoprecipitation in 293A cells transfected with the pcDNA3.1-GFP control ( FIG. 6D ). While the transcriptional coactivators TRRAP/p434, TIP48, TIP49, and hGCN5 were present in Myc-containing complexes in both HTLV-1 p30 II -GFP and GFP-expressing cells, the TIP60 HAT was predominantly detected in HTLV-1 p30 II -GFP/Myc/TIP60 complexes (compare FIGS. 6B and 6D ). However, TIP60 was weakly present in Myc-containing ChIP complexes in GFP-expressing cells consistent with the demonstration of pre-existing Myc-TIP60 interactions by Frank et al. (2003, EMBO Rep. 4:575-580) and Patel et al. (2004, Mol. Cell Biol. 24:10826-10834) ( FIGS. 6C and 6D ). [0099] To determine whether the HTLV-1 p30 II -GFP protein also transcriptionally activates the human cyclin D2 promoter in a TIP60-dependent manner, 293A fibroblasts were co-transfected with a tk promoter-renilla-luciferase plasmid, a human dyclin D2 promoter-luciferase reporter plasmid and CMV-HTLV-1 p30 II -GFP in the presence of increasing amounts of either CMV-TIP60 (wild-type) or CMV-TIP60 ΔHAT , which expresses a trans-dominant-negative TIP60 mutant. Results shown in FIG. 6E demonstrate that HTLV-1 p30 II -GFP transcriptionally activates the human cyclin D2 promoter approximately 14-fold in transfected 293A fibroblasts compared to an empty pcDNA3.1-GFP control. Over-expression of wild-type TIP60, in the presence of HTLV-1 p30 II -GFP, significantly increased p30 II -GFP-dependent transcriptional activity in a dose-dependent manner ( FIG. 6E ). Co-expression of the trans-dominant-negative TIP60 ΔHAT mutant repressed p30 II -GFP-dependent trans-activation from the human cyclin D2 promoter ( FIG. 6E ), consistent with results in FIG. 4A and an essential role for the TIP60 HAT in HTLV-1 p30 II transcriptional activation. Relative renilla-luciferase activities for each sample are shown in FIG. 6F for comparison of similar transfection efficiencies. [0100] HTLV-1 p30 II transcriptionally activates numerous cellular genes in a TIP60-dependent or TIP60-independent manner. To comprehensively identify cellular gene sequences whose expression is altered by HTLV-1 p30 II -TIP60 transcriptional interactions, 293A fibroblasts were co-transfected with a COS empty vector control, CMV-HTLV-1 p30 II (HA), or CMV-HTLV-1 p30 II (HA) +TIP60 ΔHAT which expresses a trans-dominant-negative mutant that interferes with endogenous TIP60 functions. Total cellular RNAs were extracted and microarray gene expression analyses were performed using Affymetrix Human U133Plus 2.0 full-genomic chips. Transcriptional activation of cellular target genes is expressed as Fold-Activation relative to the empty CβS vector control and the lower-limit for trans-activation was set at 2.5-fold. FIG. 7A shows a graphical representation of cellular target genes transcriptionally activated by HTLV-1 p30 II (HA) (red lines). TIP60-dependent gene sequences were identified based upon their transcriptional repression in the presence of the TIP60 ΔHAT mutant and are indicated by green lines ( FIG. 7A ). In general, the fold trans-activation by HTLV-1 p30 II (HA) ranged between 2.5-fold to 393-fold for specific target genes ( FIG. 7A ). Numerous cellular genes are also transcriptionally repressed as a result of HTLV-1 p30 II expression. Results in FIG. 7B are a graphical representation of cellular target genes transcriptionally repressed (with levels ranging between 2.5-fold to 125-fold trans-repression) by HTLV-1 p30 II (HA) (red lines). Effects of the trans-dominant-negative TIP60 HT mutant upon transcriptional repression by HTLV-1 p30 II (HA) are indicated by green lines ( FIG. 7B ) Table 3 is a representative list of the major target gene sequences that are transcriptionally activated by HTLV-1 p30 II (HA) as determined by Affymetrix microarray gene expression analyses. TIP60-dependent gene sequences are indicated. Numerous cellular genes were transcriptionally induced by HTLV-1 p30 II (HA) in a TIP60-dependent or TIP60-independent manner, suggesting that p30 II may participate in multiple, distinct transcription complexes (Table 3). TABLE 3 Target sequences transcriptionally-activated by HTLV-1 p30″ (HA) in a TIP60-dependent or TIP60-independent manner HTLV-1 TIP60- HTLV-1 p30 II / Depen- p30 II TIP60 ΔHAT Gene or Sequence Identity dent 393.8725 396.7248 TITLE = zinc finger protein 236 /DEF = Homo sapiens cDNA FLJ20840 fis, clone ADKA02336. 69.33333 2.666667 Homo sapiens , clone Yes IMAGE: 4813412, mRNA 65.5 7 Hs.42369 /UG_TITLE = ESTs Yes 56 46.4 UG = Hs.66114 /UG_TITLE = ESTs 52.75 1 CPX chromosome region, Yes candidate 1 /DEF = Homo sapiens cDNA FLJ25780 fis, clone TST06618. 49.09091 0.909091 Hs.131856 /UG_TITLE = ESTs Yes 48 43 Hs.23196 /UG_TITLE = ESTs 45.4 43.06667 Hs.116301 /UG_TITLE = ESTs 40.44444 18.22222 Hs.200286 /UG_TITLE = ESTs Yes 40.16667 22 Homo sapiens , clone Yes IMAGE: 4812574, mRNA. 34.625 49.375 Homo sapiens , clone IMAGE: 5172609, mRNA. 34.44444 3.444444 Hs.122442 /UG_TITLE = ESTs Yes 31.85714 3.857143 Homo sapiens cystic Yes fibrosis transmembrane conductance regulator isoform 36 (CFTR) mRNA, partial cds. 31.1875 1 Homo sapiens myeloid cell Yes nuclear differentiation antigen (MNDA), mRNA 31 2.75 Hs.145611 /UG_TITLE = ESTs Yes 30.88889 3.555556 Hs.120414 /UG_TITLE = ESTs Yes 28.06667 10.66667 Hs.125291 /UG_TITLE = ESTs Yes 27.72222 1.722222 H. sapiens mRNA HTPCRX06 for Yes olfactory receptor. 27.625 28 Homo sapiens , clone IMAGE: 5223057, mRNA. 26.65217 7.73913 TESTI2017113. Yes 26.1875 1.5625 protocadherin 15 /DEF = Homo Yes sapiens mRNA; cDNA DKFZp667A1711 (from clone DKFZp667A1711). 25.5 1.333333 Hs.279616 /UG_TITLE = ESTs, Yes Highly similar to KIAA1387 protein ( H. sapiens ) 25.16667 11.55556 Homo sapiens full length Yes insert cDNA clone YW25E05 24.83333 29.83333 Hs.208486 /UG_TITLE = ESTs 24.7619 11.90476 Homo sapiens mRNA; cDNA DKFZp313L0839 (from clone DKFZp313L0839). 24.71429 14.92857 Homo sapiens synaptonemal complex protein 1 (SYCP1), mRNA. /PROD = synaptonemal complex protein 1 /FL = gb: NM_003176.1 gb: D67 24.64286 2.785714 Homo sapiens cDNA FLJ14020 fis, clone HEMBA1002508. 24.09091 27.18182 Homo sapiens , clone IMAGE: 5269594, mRNA. 23.73333 1.933333 Hs.99578 /UG_TITLE = ESTs, Yes Highly similar to PTPD_HUMAN PROTEIN- TYROSINE PHOSPHATASE DELTA PRECURSOR ( H. sapiens ) 23.58065 22.03226 H. sapiens mRNA for gonadotropin-releasing hormone receptor, splice variant. /PROD = gonadotropin- releasing hormone receptor 23.3913 4.913043 Homo sapiens cDNA FLJ12548 Yes fis, clone NT2RM4000657, weakly similar to 1- PHOSPHATIDYLINOSITO 23 2.833333 Homo sapiens cDNA FLJ37910 Yes fis, clone CTONG1000040. 22.65 17.15 Homo sapiens mRNA for pH- sensing regulatory factor of peptide transporter, complete cds. 22.35714 2 Homo sapiens , clone Yes IMAGE: 4398590, mRNA. 22.125 0.625 Homo sapiens cDNA: FLJ20870 Yes fis, clone ADKA02524. 21.83333 13.58333 Homo sapiens cDNA FLJ11096 fis, clone PLACE1005480. 21.8 7.1 Hs.60556 /UG_TITLE = ESTs Yes 21.47059 1.058824 Homo sapiens , clone Yes IMAGE: 5742085, mRNA. 21.4 1.2 Hs.130544 /UG_TITLE = ESTs Yes 21 7.208333 Hs.222222 /UG_TITLE = ESTs Yes 20.85714 7.214286 Homo sapiens osteoglycin Yes (osteoinductive factor, mimecan) (OGN), mRNA 20.73913 17.82609 Hs.222120 /UG_TITLE = ESTs 20.71429 19.78571 Homo sapiens cDNA FLJ25595 fis, clone JTH13269. 20.7 4.3 Homo sapiens cDNA FLJ13003 Yes fis, clone NT2RP3000418. 20.42857 7.035714 Human DNA sequence from Yes clone 733D15 on chromosome Xp11.3. Contains a Zinc- finger (pseudo?) gene and G 20.42857 6.714286 Hs.132649 /UG_TITLE = ESTs Yes 20.28235 10.15294 Homo sapiens cDNA FLJ11475 Yes fis, clone HEMBA1001734, moderately similar to CADHERIN-11 PRECURSOR 20.25 4.75 Homo sapiens epiregulin Yes (EREG), mRNA 20.2381 15.52381 Homo sapiens cDNA FLJ39700 fis, clone SMINT2011588, weakly similar to Kruppe 20.04545 9.136364 Homo sapiens mRNA; cDNA Yes DKFZp434P2450 (from clone DKFZp434P2450). 19.95238 1 paraneoplastic Yes encephalomyelitis antigen {5 region, alternatively spliced} (human, lung cancer cell line, mRNA Partial, 10 19.78261 15.65217 Homo sapiens aldehyde oxidase 1 (AOX1), mRNA 19.77778 13.77778 Hs.293582 /UG_TITLE = ESTs 19.75 6.833333 Homo sapiens cDNA: FLJ21221 Yes fis, clone COL00570. 19.71795 15.89744 Homo sapiens cDNA FLJ40624 fis, clone THYMU2013981. 19.69565 23.95652 colony stimulating factor 2 receptor, beta, low- affinity (granulocyte- macrophage) 19.6 12.46667 Human deleted in azoospermia protein (DAZ) mRNA, complete cds 19.57143 19.85714 glutamate receptor, ionotropic, kainate 2 /DEF = Homo sapiens mRNA for GluR6 kainate receptor (GRIK2 gene), isoform-b 19.55556 2.111111 hypothetical protein Yes LOC285419 /DEF = Homo sapiens , clone IMAGE: 4839001, mRNA 19.52941 1.235294 Homo sapiens sperm Yes associated antigen 11 (SPAG11), transcript variant B, mRNA. 19.25926 9.185185 Homo sapiens mRNA; cDNA Yes DKFZp434L1717 (from clone DKFZp434L1717); complete cds 19.24138 20.31034 Homo sapiens cDNA FLJ35054 fis, clone OCBBF2018380. 19.16667 14.11111 Hs.36683 /UG_TITLE = ESTs 19.07143 8 Hs.106645 /UG_TITLE = ESTs Yes 18.93333 37.53333 Homo sapiens cDNA FLJ11602 fis, clone HEMBA1003908 18.90476 15.38095 Homo sapiens , clone IMAGE: 5164933, mRNA 18.71429 40.71429 Hs.176420 /UG_TITLE = ESTs 18.7037 2.222222 Homo sapiens , Similar to Yes BCL2-associated athanogene, clone IMAGE: 4310445, mRNA 18.66667 20.06667 DNA segment on chromosome X (unique) 9928 expressed sequence 18.5 5.958333 Homo sapiens PIAS-NY Yes protein mRNA, complete cds 18.47368 4.368421 Homo sapiens full length Yes insert cDNA clone YI41H11 18.46154 4.615385 Homo sapiens pre-TNK cell Yes associated protein (1D12A), mRNA 18.45455 17.24242 Homo sapiens mRNA differentially expressed in malignant melanoma, clone F MM K2 18.23529 3.529412 Homo sapiens cDNA FLJ32062 Yes fis, clone OCBBF1000042. 18.14286 6 Hs.204562 /UG_TITLE = ESTs Yes 18.03226 7.451613 Hs.269931 /UG_TITLE = ESTs Yes 18 13.58333 Homo sapiens , clone IMAGE: 4393885, rnRNA, partial cds 17.76471 24.88235 Hs.23187 /UG_TITLE = ESTs 17.71429 23.07143 Hs.42993 /UG_TITLE = ESTs 17.625 1.5 Homo sapiens glypican 5 Yes (GPC5), mRNA 17.6129 12.12903 Homo sapiens mRNA; cDNA DKFZp686C1636 (from clone DKFZp686C1636) 17.5 21.53125 Hs.213386 /UG_TITLE = ESTs 17.48276 2 Hs.99200 /UG_TITLE = ESTs Yes 17.47826 2.913043 Hs.17388 /UG_TITLE = ESTs Yes 17.47368 6.710526 MCF.2 cell line derived Yes transforming sequence-like /DEF = Homo sapiens , clone IMAGE: 5185971, mRNA 17.40541 3.486486 Hs.6656 /UG_TITLE = ESTs Yes 17.36842 15.73684 Hs.22249 /UG_TITLE = ESTs 17.31169 16.42857 Hs.20103 /UG_TITLE = ESTs 17.09091 17.09091 Human (clone CTG-A4) mRNA sequence 17.09091 22.36364 Homo sapiens cDNA FLJ36285 fis, clone THYMU2003470. 17 16.44444 Homo sapiens SAM domain, SH3 domain and nuclear localisation signals, 1 (SAMSN1), mRNA. /PROD = SAM domain, SH3 domain and nuclear 16.83333 17.69444 Homo sapiens , clone MGC: 34025 IMAGE: 4828588, mRNA, complete cds. /PROD = Unknown (protein for MGC: 34025) 16.83333 15.58333 Homo sapiens , clone IMAGE: 4838843, mRNA 16.81818 0.727273 Hs.97977 /UG_TITLE = ESTs Yes 16.75556 4.377778 Homo sapiens mRNA; cDNA Yes DKFZp586O2023 (from clone DKFZp586O2023) 16.66667 17.75 Hs.36409.0 /TIER = ConsEnd /STK = 4 /UG = Hs.36409 /UG_TITLE = ESTs 16.65789 11.65789 Human hepatocyte nuclear factor-6 alpha (HNF6) mRNA, complete cds 16.625 3.5 Hs.188950 /UG_TITLE = ESTs Yes 16.625 11.0625 Hs.277419 /UG_TITLE = ESTs 16.61111 12.77778 pancreatic ribonuclease (human, mRNA Recombinant Partial, 491 nt) 16.54545 15.09091 Homo sapiens , clone IMAGE: 5277680, mRNA, partial cds. 16.53488 3.860465 Homo sapiens glutamate Yes receptor, ionotrophic, AMPA 4 (GRIA4), mRNA. /PROD = glutamate receptor, ionotrophic /FL = gb: U16129.1 gb: NM_0 16.46575 11.61644 endothelin receptor type A /FL = gb: NM_001957.1 gb: L06622.1 16.42857 4.761905 Hs.99472 /UG_TITLE = ESTs Yes 16.42105 5.631579 Homo sapiens mRNA for type Yes I keratin. /PROD = HHa5 hair keratin type I intermediate filament 16.40909 3.227273 Homo sapiens protein Yes tyrosine phosphatase, receptor-type, Z polypeptide 1 (PTPRZ1), mRNA 16.36 22.4 Homo sapiens neuropeptide Y receptor Y5 (NPY5R), mRNA 16.2 48.8 Homo sapiens cDNA: FLJ20890 fis, clone ADKA03323. 16.05882 3.882353 syntaphilin Yes 16 13.5 Human DNA sequence from clone RP4-545L17 on chromosome 20p12.2-13. Contains the 5 end of the gene for a novel protein similar to RAD21 (S. pom 15.95522 8.552239 Homo sapiens cDNA FLJ36177 Yes fis, clone TESTI2026515. 15.91667 0.5 Hs.40840 /UG_TITLE = ESTs Yes 15.89474 25.12281 Homo sapiens cDNA FLJ13602 fis, clone PLACE1010089, highly similar to Homo sapiens mRNA for 15.88235 1.156863 Human CB-4 transcript of Yes unrearranged immunoglobulin V(H)5 gene /DEF = Human CLL- 12 transcript of unrearranged immuno 15.875 18.5 Homo sapiens , clone IMAGE: 4823434, mRNA 15.85185 1.888889 Hs.173596 /UG_TITLE = ESTs Yes 15.83333 3.944444 Homo sapiens GPBP- Yes interacting protein 90 mRNA, complete cds 15.81481 0.888889 Homo sapiens , Similar to Yes recombination activating gene 1, clone MGC: 43321 IMAGE: 5265661, mRNA, complete cds 15.72414 2.241379 Homo sapiens cDNA FLJ37001 Yes fis, clone BRACE2008172. 15.71429 11.42857 Homo sapiens , Similar to RIKEN cDNA 4833427G06 gene, clone IMAGE: 5561932, mRNA 15.6875 9.0625 Homo sapiens , clone IMAGE: 4831108, mRNA 15.6875 0.78125 Homo sapiens , clone Yes IMAGE: 5295305, mRNA 15.63636 5.681818 Hs.98388 /UG_TITLE = ESTs Yes 15.61538 11.11538 methyl-CpG binding domain protein 2 15.59677 267.7419 Hs.154993 /UG_TITLE = ESTs 15.54545 9.181818 Homo sapiens transmembrane phosphatase with tensin homology (TPTE), mRNA. 15.52632 10.31579 Hs.105620 /UG_TITLE = ESTs 15.42857 23.28571 Homo sapiens acetyl LDL receptor; SREC = scavenger receptor expressed by endothelial cells (SREC), mRNA. /PROD = acetyl LDL receptor; SR 15.36842 0.684211 Homo sapiens cDNA: FLJ21351 Yes fis, clone COL02762 15.36364 1.454545 Homo sapiens cDNA FLJ30168 Yes fis, clone BRACE2000750. 15.3 12.83333 Homo sapiens clone 148022 iduronate-2-sulfatase (IDS2) pseudogene, mRNA sequence 15.27027 3.324324 Homo sapiens microtubule- Yes associated protein tau (MAPT), transcript variant 1, mRNA. 15.23077 12.15385 Homo sapiens , clone IMAGE: 4830182, mRNA. 15.21429 2.642857 Homo sapiens mRNA; cDNA Yes DKFZp434H0872 (from clone DKFZp434H0872). 15.21053 1.684211 Homo sapiens cDNA: FLJ22630 Yes fis, clone HSI06250. 15.19231 11.76923 Homo sapiens H2B histone family, member N (H2BFN), mRNA 15.19048 1.47619 Homo sapiens cDNA FLJ11921 Yes fis, clone HEMBB1000318. 15.16667 1.233333 Hs.168268 /UG_TITLE = ESTs, Yes Moderately similar to A35969 heparin-binding growth factor receptor K- sam precursor ( H. sapiens ) 15.125 1.1875 Human EST clone 53125 Yes mariner transposon Hsmar1 sequence 15.09375 4 Homo sapiens , clone Yes MGC: 47837 IMAGE: 6046539, mRNA, complete cds. /PROD = Unknown (protein for MGC: 47837) 15.07407 4.277778 Homo sapiens cDNA: FLJ21710 Yes fis, clone COL10087. 15.06667 15.96667 Hs.143834 /UG_TITLE = ESTs 15.05128 5.512821 hypothetical protein Yes FLJ20271 /FL = gb: NM_017734.1 15.02564 5.974359 Homo sapiens full length Yes insert cDNA clone YP60H04 15.02326 11.44186 Homo sapiens calsyntenin-2 (CS2), mRNA. /PROD = calsyntenin-2 15 1.5 Hs.104572 /UG_TITLE = ESTs Yes 14.9403 12.67164 Homo sapiens inhibin, beta C (INHBC), mRNA. /PROD = inhibin beta C subunit precursor 14.88462 11.82692 Homo sapiens cDNA FLJ10146 fis, clone HEMBA1003327 14.80851 15.65957 gb: AW451826 /DB_XREF = gi: 6992602 /DB_XREF = UI-H-BI3-alk-e-07- 0-UI.s1 /CLONE = IMAGE: 2737236 /FEA = EST /CNT = 8 /TID = Hs.258791.0 /TIER = ConsEnd /STK = 4 /UG = Hs.258791 /UG_TITLE = ESTs 14.78788 5.348485 gb: BF590323 Yes /DB_XREF = gi: 11682647 /DB_XREF = nab22h10.x1 /CLONE = IMAGE: 3266922 /FEA = EST /CNT = 33 /TID = Hs.55256.0 /TIER = Stack /STK = 30 /UG = Hs.55256 /UG_TITLE = ESTs 14.71154 0.442308 Homo sapiens , clone Yes IMAGE: 4815474, mRNA 14.69565 12.67391 Homo sapiens RAGE mRNA for advanced glycation endproducts receptor, complete cds. 14.65217 22.82609 Homo sapiens , clone MGC: 10724, mRNA, complete cds. /PROD = Unknown (protein for MGC: 10724) 14.64286 2.571429 Homo sapiens mRNA; cDNA Yes DKFZp761D191 (from clone DKFZp761D191) 14.61538 1.307692 Hs.313876 /UG_TITLE = ESTs Yes 14.53488 8.348837 CGI-67 protein 14.5 9.772727 Hs.132650 /UG_TITLE = ESTs 14.42857 1.619048 Hs.293685 /UG_TITLE = ESTs Yes 14.41667 4.708333 Hs.143789 /UG_TITLE = ESTs Yes 14.40909 5.181818 Homo sapiens cDNA FLJ13755 Yes fis, clone PLACE3000363. 14.33333 2.888889 Hs.327117 /UG_TITLE = ESTs Yes 14.29032 1.903226 Hs.161566 /UG_TITLE = ESTs Yes 14.27778 1.055556 Homo sapiens , clone Yes IMAGE: 4778480, mRNA. 14.23077 15.84615 Homo sapiens , Similar to hypothetical protein FLJ22792, clone MGC: 22933 IMAGE: 4905554, mRNA, complete cds 14.20513 1 Hs.162565 /UG_TITLE = ESTs Yes 14.14815 21.37037 Homo sapiens , Similar to sex comb on midleg-like 3 ( Drosophila ), clone MGC: 25118 IMAGE: 4509724, mRNA, complete cds. 14.14286 11.57143 Homo sapiens olfactory-like receptor JCG8 (JCG8) mRNA, complete cds. /PROD = olfactory-like receptor JCG8 14.1 1 5.3 Homo sapiens , clone IMAGE: 5267701, mRNA 14.06667 5.15 Homo sapiens cDNA FLJ34667 Yes fis, clone LIVER2000769. /DEF = Homo sapiens cDNA FLJ34667 fis, clone LIVER2000769. 14.05882 7.588235 major histocompatibility Yes complex, class II, DR beta 3 14.05882 3.176471 Hs.125962 /UG_TITLE = ESTs Yes 14.05833 6.35 Hs.293118 /UG_TITLE = ESTs Yes 14.03896 13.66234 Hs.20726 /UG_TITLE = ESTs 14.02778 9.555556 Homo sapiens , clone MGC: 14510, mRNA, complete cds. /PROD = Unknown (protein for MGC: 14510) 14.02632 17.39474 Homo sapiens CD84 antigen (leukocyte antigen) (CD84), mRNA. /PROD = CD84 antigen (leukocyte antigen) 14 11.90909 Hs.296235 /UG_TITLE = ESTs 14 38.29412 prostate specific G-protein coupled receptor /DEF = Homo sapiens prostate specific G-protein coupled receptor gene, comple 14 22.2 Homo sapiens cystic fibrosis transmembrane conductance regulator isoform 36 (CFTR) mRNA, partial cds 13.97826 12.54348 Homo sapiens testis transcript Y 9 (TTY9) mRNA, complete cds 13.90625 0.9375 Hs.88450 /UG_TITLE = ESTs Yes 13.9 1.1 Hs.20468 /UG_TITLE = ESTs Yes 13.89474 3.421053 Homo sapiens cDNA: FLJ21618 Yes fis, clone COL07487. 13.85294 2.352941 Homo sapiens fibroblast Yes growth factor 20 (FGF20), mRNA 13.81818 3.136364 Homo sapiens mRNA; cDNA Yes DKFZp761J1323 (from clone DKFZp761J1323). 13.80769 2.307692 Hs.407438 Yes /UG_TITLE = neurogenic differentiation 1 13.78788 12.45455 Homo sapiens hypothetical protein FLJ12983 (FLJ12983), mRNA 13.7549 9.77451 Human DNA sequence from clone RP5-1184F4 on chromosome 20q11.1-11.23. Contains the 3 end of gene KIAA0978, two genes for novel proteins similar 13.73333 8.8 Hs.201420 /UG_TITLE = ESTs 13.71429 12.17857 Homo sapiens cDNA FLJ12573 fis, clone NT2RM4000979 13.7 23.3 Hs.244710 /UG_TITLE = ESTs 13.68293 5.585366 Homo sapiens tenascin R Yes (restrictin, janusin) (TNR), mRNA. /PROD = tenascin R (restrictin, janusin) 13.66667 1.606061 Hs.99336 /UG_TITLE = ESTs Yes 13.64045 9.280899 Homo sapiens testis- specific ankyrin motif containing protein (LOC56311), mRNA. 13.61538 1.846154 Hs.130922 /UG_TITLE = Homo Yes sapiens , Similar to likely ortholog of yeast ARV1, clone IMAGE: 5265646, mRNA 13.59259 0.814815 olfactory receptor, family Yes 2, subfamily M, member 4 /DEF = H. sapiens mRNA for TPCR100 protein. 13.57143 3.142857 Homo sapiens , clone Yes IMAGE: 4694422, mRNA. 13.55882 3.661765 Homo sapiens small Yes intestine aquaporin mRNA, complete cds 13.55172 3.689655 Homo sapiens mRNA; cDNA Yes DKFZp564I083 (from clone DKFZp564I083) 13.55172 1.448276 gb: H47594 Yes /DB_XREF = gi: 923646 /DB_XREF = yp75c01.s1 /CLONE = IMAGE: 193248 /TID = Hs2.407314.1 /CNT = 3 /FEA = mRNA /TER = ConsEnd /STK = 1 /UG = Hs.407314 /UG_TITLE = Homo sapiens full length insert cDNA clone YP75C01 13.53846 7.807692 Homo sapiens cDNA FLJ39005 fis, clone NT2RI2024496 13.52941 11.2549 gb: H46217 /DB_XREF = gi: 922269 /DB_XREF = yo14h12.s1 /CLONE = IMAGE: 177959 /FEA = EST /CNT = 4 /TID = Hs.268805.0 /TIER = ConsEnd /STK = 4 /UG = Hs.268805 /UG_TITLE = ESTs 13.5 8.535714 Hs.250113 /UG_TITLE = ESTs, Moderately similar to thyroid hormone receptor- associated protein complex component TRAP150 (H. sap 13.40909 9.863636 Homo sapiens , clone IMAGE: 3933453, mRNA 13.36842 0.842105 Hs.28714 /UG_TITLE = ESTs Yes 13.35714 1.357143 Homo sapiens , clone Yes IMAGE: 5266862, mRNA. 13.35135 12.81081 Hs.158937 /UG_TITLE = ESTs 13.35 1.65 Homo sapiens cDNA FLJ13136 Yes fis, clone NT2RP3003139 13.33333 6.6 Homo sapiens non-coding RNA Yes HANC 13.30769 7.410256 Hs.25046 /UG_TITLE = ESTs 13.29384 8.21327 Homo sapiens protein kinase C, alpha binding protein (PRKCABP), mRNA 13.2807 4.017544 Homo sapiens hypothetical Yes protein FLJ10979 (FLJ10979), mRNA. /PROD = hypothetical protein FLJ10979 13.25 7.15 Homo sapiens full length insert cDNA clone YI41B09 13.24138 0.896552 Homo sapiens , clone Yes IMAGE: 4818264, mRNA 13.2381 10.2619 Homo sapiens , clone IMAGE: 4824978, mRNA 13.23333 15.1 gb: AA776626 /DB_XREF = gi: 2835960 /DB_XREF = ae86f02.s1 /CLONE = IMAGE: 971067 /FEA = EST /CNT = 12 /TID = Hs.62183.0 /TIER = ConsEnd /STK = 1 /UG = Hs.62183 /UG_TITLE = ESTs 13.2 8 myelin oligodendrocyte glycoprotein /DEF = Human DNA sequence from clone RP11- 145L22 on chromosome 6p21.32-22.2 13.18182 0.818182 Homo sapiens regulator of Yes G-protein signaling 1 (RGS1), mRNA. /PROD = regulator of G- protein signaling 1 13.11111 12.11111 Homo sapiens clone HQ0202 PRO0202 mRNA, partial cds 13.09091 17.30303 cytoplasmic linker associated protein 2 13.09091 17.63636 H. sapiens AA1 mRNA 13.04762 1.380952 Homo sapiens , clone Yes IMAGE: 4825614, mRNA. 13 1.75 Human clone 23909 mRNA, Yes partial cds. /PROD = unknown 13 1.657143 Homo sapiens cDNA FLJ12289 Yes fis, clone MAMMA1001788 12.93333 11.66667 Homo sapiens mRNA for keratin associated protein 4.7 (KRTAP4.7 gene) 12.93103 0.413793 Hs.43052 /UG_TITLE = ESTs Yes 12.92308 4.846154 Homo sapiens cDNA FLJ14152 Yes fis, clone MAMMA1003089. 12.88 1.52 Hs.118342 /UG_TITLE = ESTs Yes 12.86207 6.965517 Homo sapiens , clone IMAGE: 4042783, mRNA. 12.84 11.68 Homo sapiens POU domain, class 4, transcription factor 2 (POU4F2), mRNA. /PROD = POU domain, class 4, transcription factor 2 12.83333 8.111111 Hs.190319 /UG_TITLE = ESTs 12.8 3.72 Hs.231951 /UG_TITLE = ESTs Yes 12.8 9.766667 Homo sapiens olfactory receptor-like protein JCG3 (JCG3), mRNA 12.78947 1.263158 Homo sapiens , clone Yes IMAGE: 4413783, mRNA. 12.78788 1.181818 Homo sapiens , clone Yes IMAGE: 4800001, mRNA. 12.76923 2 Homo sapiens , clone Yes IMAGE: 4828930, mRNA. 12.76471 1.705882 Homo sapiens mRNA expressed Yes only in placental villi, clone SMAP41 12.75 7.08333 Hs.259168 /UG_TITLE = ESTs 12.69565 17.47826 Homo sapiens hypothetical protein FLJ21272 (FLJ21272), mRNA 12.6875 7.333333 Hs.92955 /UG_TITLE = ESTs 12.67857 4.071429 hypothetical protein Yes FLJ10024 /DEF = Homo sapiens cDNA FLJ13978 fis, clone Y79AA1001665. 12.66102 9.050847 Homo sapiens RNA binding motif protein, Y chromosome, family 2, member B (RBMY2B) mRNA. /PROD = RNA binding motif protein, Y chromos 12.61538 1.384615 Hs.127556 /UG_TITLE = ESTs Yes 12.57576 9.636364 Hs.44736 /UG_TITLE = ESTs 12.55172 0.724138 hypothetical protein Yes LOC285965 /DEF = Homo sapiens mRNA; cDNA DKFZp686O0656 (from clone DKFZp686O0656). 12.54839 7.709677 Hs.276363 /UG_TITLE = hypothetical protein LOC283112 12.53333 14.86667 REPL1S /UG_TITLE = ret finger protein-like 1 antisense 12.50847 1.559322 Hs.98945 /UG_TITLE = ESTs Yes 12.5 6.136364 Hs.213371 /UG_TITLE = ESTs Yes 12.45946 7.297297 Homo sapiens , similar to hypothetical protein, clone MGC: 27103 IMAGE: 4831323, mRNA, complete cds. 12.42424 16.54545 Homo sapiens GLB2 gene, upstream regulatory region [0101] With respect to the potential role of HTLV-1 p30 II in adult T-cell leukemogenesis, transcriptional activation of the following genes is of significant interest: myeloid cell nuclear differentiation 1 antigen (31.1-fold; TIP60-dependent), protocadherin 15 (26.1-fold; TIP60-dependent), human protein tyrosine-phosphatase delta precursor (23.3-fold; TIP60-dependent), cadherin 11-like precursor (20.2-fold; TIP60-dependent), colony stimulating factor 2 receptor, beta (19.6-fold; TIP60-independent), human protein tyrosine-phosphatase receptor-type Z polypeptide (16.4-fold; TIP60-dependent), S. pombe RAD21-like protein (16-fold; TIP60-independent), human transmembrane phosphatase with tensin homology (15.5-fold; TIP60-independent), H2B histone family member N (15.1-fold; TIP60-independent), major histocompatibility complex class II DR beta 3 (14.0-fold; TIP60-dependent), human CD84 leukocyte antigen (14.0-fold; TIP60-independent), prostate-specific G-protein coupled receptor (14.0-fold; TIP60-independent), fibroblast growth factor 20 (13.8-fold; TIP60-dependent), protein kinase C alpha-binding protein (13.2-fold; TIP60-independent), regulator of G-protein-signaling 1 (13.1-fold; TIP60-dependent), cytoplasmic linker associated protein 2 (13.0-fold; TIP60-independent), POU domain 4 transcription factor 2 (12.8-fold; TIP60-independent), and RNA-binding motif protein (RBMY2B) (12.6-fold; TIP60-independent). Infectious HTLV-1 molecular clone, ACH.p30 II , exhibits an approx 20-50% reduction in transformation-efficiency compared to the wild-type ACH.wt suggesting that p30 II is required for the full-transforming potential of HTLV-1. Microarray analyses indicates that numerous cellular genes are transcriptionally activated by p30 II , and proteins encoded by these genes may contribute to HTLV-1 leukemic transformation and development of ATLL. [0102] HTLV-1 p30 II enhances Myc transforming potential and requires the TIP60 HAT and TRRAP/p434. Since the c-Myc oncogene is known to cause cellular transformation, foci-formation assays using immortalized human WRN −/− fibroblasts, which lack Werner's Syndrome helicase functions were used to determine whether HTLV-1 p30 II might influence Myc-associated transforming activity. This cellular background was chosen because ATLL is an aging-related malignancy requiring clinical latency periods of 25-40 years prior to disease onset, which suggests that genetic mutations linked to the aging process likely contribute to leukemogenesis. Werner's Syndrome is a premature-aging disorder that mimics or recapitulates many of the clinical and cellular features of normal aging; and WRN locus (8p11-12) mutations have been found in HTLV-1-infected ATLL patient lymphocytes and in HTLV-1-infected mycosis fungoides/Sezary syndrome cells. Neither Myc nor HTLV-1 p30 II (HA) alone significantly induces foci-formation in immortalized human WRN −/− fibroblasts ( FIG. 8A ). Surprisingly, in combination, HTLV-1 p30 II (HA)-Myc co-expression reproducibly induces between 35-58 foci in different assays ( FIGS. 8A and 8B ). HTLV-1 p30 II (HA) expression was detected in transformed colonies by immunofluorescence-microscopy ( FIG. 8C ); and the p30 II protein appeared to be distributed throughout the nucleoplasm ( FIG. 8D ). A high-incidence of multi-nucleated giant cells were also observed in isolated HTLV-1 p30 II (HA)-Myc-transformed fibroblasts that were expanded in culture, consistent with HTLV-1 p30 II -induced polyploidy observed during BrdU-FACS analyses ( FIG. 8E ; compare to control cells in FIG. 8C ). Expression of HTLV-1 p30 II (HA) in transformed fibroblasts was confirmed by immunoblotting using a monoclonal anti-HA antibody ( FIG. 8E ). Indeed, these findings indicate that HTLV-1 p30 II markedly enhances the transforming potential of Myc and may promote genomic instability resulting in polyploidy. [0103] The foregoing transcriptional activation data suggested that enhancement of Myc functions by HTLV-1 p30 II requires the coactivators TIP60 and TRRAP/p434. Therefore, tests were performed to determine whether foci-formation induced by co-expressing HTLV-1 p30 II (HA)-Myc might be affected by over-expressing wild-type TIP60 or TIP60 ΔHAT and TIP60 L497A mutant proteins. Results from two independent experiments shown in FIG. 9A indicate that none of the TIP60 expression constructs, either alone or in combination with Myc, significantly induces foci-formation in immortalized human WRN −/− fibroblasts. However, ectopic TIP60 markedly increases foci-formation induced by HTLV-1 p30 II (HA)-Myc co-expression ( FIG. 9A ). The trans-dominant negative TIP60 ΔHAT mutant completely abrogated colony formation by HTLV-1 p30 II (HA)-Myc, and the TIP60 L497A mutant partially inhibited foci-formation ( FIG. 9A ). Increased colony formation by HTLV-1 p30 II (HA)/Myc/TIP60, compared to inhibition of foci-formation by the trans-dominant-negative TIP60 ΔHAT mutant, is shown in FIGS. 9C and 9D . Finally, inhibition of TRRAP/p434, as a result of co-expressing increasing amounts of TRRAP anti-sense RNA, also significantly decreased foci-formation by HTLV-1 p30 II (HA)-Myc ( FIG. 9E ). These findings collectively agree with the transcriptional activation data, and suggest that HTLV-1 p30 II enhances Myc transcriptional and transforming activities in a TIP60 HAT-and TRRAP-dependent manner ( FIG. 10 ). [0104] The HTLV-1 infects CD4 + T-cells and promotes deregulated cell-growth and lymphoproliferation associated with development of ATLL. While numerous studies have demonstrated that the viral Tax protein transcriptionally-activates growth/proliferative-signaling pathways, it has become increasingly evident that other pX-encoded regulatory factors (p12 I , p13 II , p30 II , Rex) are likely to perform essential functions during adult T-cell leukemogenesis. Indeed, the majority of partially-deleted HTLV-1 proviruses in ATLL patient isolates contain intact pX sequences; and alternatively-spliced ORF I and ORF II mRNAs have been detected in HTLV-1-infected transformed T-cell-lines and ATLL patient samples. Cytotoxic T-lymphocytes (CTLs) specifically targeted against ORF I and ORF II peptides have been obtained from ATLL patients suggestive that these proteins are present during in vivo HTLV-1 infections. Zhang et al. (2001) reported that p30 II interacts with p300/CREB-binding protein and represses Tax-mediated trans-activation from the HTLV-1 LTR (83) and differentially modulates CREB-dependent transcription (84). Nicot et al. (2004. ref. 46) and Younis et al. (2004. ref. 82) have demonstrated that p30 II prevents nuclear export of the doubly-spliced Tax/Rex mRNA and others have shown that p30 II is required for maintenance of high viral titers in a rabbit model of ATLL using an infectious HTLV-1 molecular clone, ACH.30 II , defective for p30 II production (4, 68). Interestingly, Robek et al. (1998) have previously demonstrated that p30 II is dispensable for immortalization and transformation of human PBMCs by ACH.p30 II , however, this mutant exhibited an approx 20-50% reduction in transformation-efficiency compared to the wild-type ACH.wt (60) suggesting that p30 II is required for the full transforming-potential of HTLV-1. The physiological role of p30 II in HTLV-1 pathogenesis remains unclear and it is intriguing that, similar to Tax, p30 II , may perform multiple functions to control viral gene expression and promote deregulation of CD4 + T-cell growth/proliferative pathways. [0105] Therefore, the data presented herein demonstrates that HTLV-1 p30 II drastically enhances Myc-associated transcriptional and transforming activities and markedly increases S-phase progression-and polyploidy through interactions with the coactivator/HAT, TIP60 ( FIG. 10 ). HTLV-1 p30 II significantly trans-activates conserved E-box enhancer elements within promoters of Myc-responsive genes, requiring TIP60 HAT activity and the transcriptional coactivator TRRAP/p434. The data presented herein indicate that, in the absence of HTLV-1 p30 II -interactions, ectopic TIP60 over-expression does not significantly alter Myc transcriptional and transforming activities in functional assays (see FIGS. 4A and 9A ). Further, TIP60 is not detectably present in Myc-containing chromatin-remodeling complexes on the human cyclin D2 promoter, in absence of HTLV-1 p30 II , in Molt-4 lymphocytes ( FIG. 5C ). Aberrant Myc-TIP60 interactions, as a result of HTLV-1 p30 II or other stabilizing factors, may prominently contribute to neoplastic transformation in hematological malignancies and solid tumors where Myc functions are deregulated or that contain Myc locus mutations. Indeed, disruption of Myc-TIP60 complexes is a plausible approach for anti-cancer therapies designed to impede malignancy. [0106] The present invention provides the first evidence, based upon biological-functional assays, that HTLV-1 p30 II is a novel retroviral enhancer of Myc-TIP60 transcriptional and transforming activities that likely plays an important role during adult T-cell leukemogenesis. EXAMPLES Example 1 Plasmids, Transfections, and Cell-Culture [0107] HeLa cells (ATCC, CCL-2) were grown in Dulbecco's Modified Eagle's Medium (D-MEM, ATCC) supplemented with 10% fetal bovine serum (FBS, Atlanta Biologicals), 100U/ml penicillin and 100 μg/ml streptomycin sulfate (Invitrogen-Life Technologies) and cultured at 37° C. under 5% CO 2 . 293A Fibroblasts (Quantum Biotechnology) were cultured in ATCC 46-X medium supplemented with sodium bicarbonate (Invitrogen-Life Technologies), 10% FBS, and 100U/ml penicillin and 100 g/ml streptomycin-sulfate. Molt-4 (ATCC, CRL-1582), Jurkat E6.1 (ATCC, TIB-152) and HTLV-1-infected MJ[G11] (ATCC, CRL-8294) and HuT-102 lymphocytes (ATCC, TIB-162) were grown in RPMI medium (ATCC) supplemented with 20% FBS, 100U/ml penicillin, 100 μg/ml streptomycin-sulfate, and 20 μg/ml gentamicin-sulfate (SIGMA Chemical Corp.) and cultured under 10% CO 2 . Primary HTLV-1-infected lymphocytes were obtained, after informed consent from three ATLL patients (ATL-1, ATL-2, ATL-3), and were cultured in RPMI medium supplemented with 20% FBS, 50U/ml hIL-2 (Invitrogen-Life Technologies), 100U/ml penicillin, 100 μg/ml streptomycin-sulfate, and 20 μg/ml gentamicin-sulfate. The CMV-HTLV-1 p30 II (HA) expression construct was kindly provided by Dr. G. Franchini (NCI, NIH) and has been reported in Koralnik et al. (1993, J. Virol. 67:2360-2366). In order to generate the human cyclin D2 promoter-luciferase reporter construct, sequences encompassing the human cyclin D2 promoter were located in GeneBank accession number U47284 clone; according to these sequences a PCR product was generated that contains 1622 nucleotides upstream of the ATG start codon. Two closely-spaced E-boxes (5′-CACGTG) are localized within the promoter region which bind Myc/Max/Mad network components (2001, Genes Dev. 15:2042-2047). This fragment was cloned into the pGL3-luciferase vector. Both E-box sequences were mutated to 5′-CTCGAG using the quick change method. The M4-tk-luciferase reporter plasmid was reported (2001, Genes Dev. 15:2042-2047; 1998, Cell 93:81-91). The CβF-FLAG-Myc, CβF-FLAG-TRRAP 1261-1579 , CβS-TRRAP anti-sense , and CβS constructs were described in McMahon et al. (1998, Cell 94:363-374). The pOZ-wildtype-TIP60 and pOZ-TIP60sAT expression constructs were reported in Ikura et al. (2000, Cell 102:463-473); and the CMV-TIP60 L497A expression plasmid was reported in Gaughan et al. (2001, J. Biol. Chem. 276:46841-46848). All transfections were performed using Lipofectamine (Invitrogen-Life Technologies) or Superfect (Qiagen) reagents as recommended. Example 2 Cell-Cycle and FACS Analyses [0108] Molt4 and Jurkat E6.1 lymphocytes were seeded in 100 mm 2 tissue-culture dishes and transfected with CMV-HTLV-1 p30 II (HA) or an empty CβS vector. Following 48 hr, cultures were split and either labeled for 4 hr by adding BrdU (BD-Pharmingen) to the medium or immediately stained using annexin-V-(FITC)/propidium iodide (BD-Pharmingen). For cell-cycle analyses, transfected BrdU-labeled cells were permeabilized and stained with a FITC-conjugated anti-BrdU antibody; and total genomic DNA was stained using 7-AAD (BD-Pharmingen). Flow cytometry was performed and data were analyzed using ModFit LT 3.0 software. Example 3 Foci-Formation/Transformation Assays [0109] Immortalized Werner's Syndrome (WRN −/− ) fibroblasts (2000, Nucleic Acids Res. 28:648-654) were seeded at 6×10 5 cells in 60 mm 2 tissue-culture dishes in D-MEM supplemented with 10% FBS and cultured at 37° C. under 5% CO 2 . Cells were transfected with an empty CβS vector, CMV-HTLV-1 p30 II (HA), CβF-FLAG-Myc, and combinations of CMV-HTLV-1 p30 II (HA)/CβF-FLAG-Myc or CβS/CβF-FLAG-Myc using Superfect reagent. Foci were observed within 2 weeks and quantified by direct counting. Expression of HTLV-1 p30 II (HA) was detected by fixing plates with 0.2% gluteraldehyde, 1% formaldehyde in PBS and immuno-staining using a monoclonal antibody against the HA-epitope tag (CA5, Roche Molecular Biochemicals), diluted 1:1000 in BLOTTO buffer (50 mM Tris-HCl, pH 8.0, 2 mM CaCl 2 , 80 mM NaCl, 0.2% v/v NP-40, 0.02% w/v sodium azide, 5% w/v non-fat dry milk). HTLV-1 p30 II (HA) was visualized by immunofluorescence-microscopy. Six p30 II -expressing fibroblast colonies were isolated and expanded in 6-well tissue-culture plates in D-MEM supplemented with 10% FBS, 100U penicillin, and 100 mg/ml streptomycin-sulfate. Example 4 Immunoprecipitations and ChIPs [0110] Myc-interacting complexes were immunoprecipitated from transfected Jurkat E6.1 or HTLV-1-infected MJ[G11] and HuT-102 lymphocytes expressing HTLV-1 p30 II (HA) using a monoclonal anti-HA tag antibody. Immunoprecipitation of endogenous p30 II , from cultured HTLV-1-infected ATLL patient-derived lymphocytes was performed using a rabbit polyclonal antibody against the COOH-terminus of p30 II (anti-HTLV-1 p30 II antibody was generously provided by Dr. G. Franchini, NCI, NIH):(J. Virol. 67:2360-2366). Briefly, 3×10 6 cells were harvested by centrifugation and lysed in RIPA buffer (1× PBS, 1% (v/v) IGEPAL CA-630, 0.5% sodium deoxycholate, 0.1% SDS) containing protease inhibitors: bestatin, pepstatin, antipain-dihydrochloride, chymostatin, leupeptin (50 ng/ml each. Roche Molecular Biochemicals) followed by passage through a 27.5-gauge tuberculin syringe. Immunoprecipitations were carried-out by incubating pre-cleared extracts with primary antibodies. Ten microliters of recombinant protein G-agarose (Invitrogen-Life Technologies) were added and reactions were incubated with agitation at 4° C. overnight. Matrices were pelleted by centrifugation at 6500 rpm for 5 min and washed twice with RIPA buffer. Samples were resuspended in 40 μl 2× SDS-PAGE loading buffer and bound proteins were resolved by electrophoresis through 4-15% gradient or 12.5% Tris-glycine SDS-polyacrylamide gels. Chromatin-immunoprecipitations were performed using a kit from Upstate Biotechnology. Nucleoprotein complexes were cross-linked in vivo by adding 270 μl formaldehyde to approximately 3×10 6 Molt-4 or HTLV-1-infected MJ[G11] and HuT-102 lymphocytes in 100 mm 2 tissue-culture dishes for 10 min. Cells were pelleted by centrifugation and resuspended in 200 μl SDS lysis buffer. Chromatin DNA was fragmented by sonication and oligonucleosomal-protein complexes were immuno-precipitated using primary antibodies and 60 μl salmon sperm DNA/protein A agarose. Precipitated oligonucleosomal-protein complexes were washed, cross-links were reversed, and bound DNA fragments were amplified by PCR using specific oligonucleotide primer pairs: PRM, 5′ -CCCCTTCCTCCTGGAGTGAAATAC-3′; (SEQ ID NO:1) and 5′ -CGTGCTCTAACGCATCCTTGAGTC-3′ (SEQ ID NO:2) that flank conserved E-box elements within the human cyclin D2 gene promoter or anneal within an untranslated region, UTR, 5′-ATCAGACCCTATTCTCGGCTCAGG-3′ (SEQ ID NO:3) and 5′-CAGTCAGTAAGGCACTTTATTTCCCC-3′ (SEQ ID NO:4) as described in Vervoorts et al. (2003, EMBO Rep. 4:484-490). [0111] PCR products were electrophoresed through a 2% TAE agarose gel and visualized by ethidium bromide-staining. [0000] Documents Cited [0112] All sequences, patents, patent applications or other published documents cited anywhere in this specification are herein incorporated in their entirety by reference to the same extent as if each individual sequence, publication, patent, patent application or other published document was specifically and individually indicated to be incorporated by reference.

Human T-cell lymphotropic virus type-1 (HTLV-1) infects and transforms CD4 + lymphocytes and causes Adult T-cell Leukemia/Lymphoma (ATLL), an aggressive, often fatal, lymphoproliferative disease. A conserved HTLV-1 3+ regulatory domain, pX, encodes at least five non-structural proteins, including the alternative splice-variant p30 II . HTLV-1 p30 II may enhance the transforming activity of Myc and transcriptionally activate the human cyclin D2 promoter, dependent upon its conserved Myc-responsive enhancer elements, associated with markedly increased S-phase entry and multi-nucleation. Enhancement of Myc transforming activity by HTLV-1 p30 II may be dependent upon the transcriptional coactivators, TRRAP/p434 6-8 and TIP60, require TIP60 histone acetyltransferase activity, and strongly correlate with interactions between HTLV-1 p30 II and Myc-TIP60 complexes in HTLV-1-infected ATLL patient-derived lymphocytes. Thus, p30 II may function as a novel retroviral modulator of Myc-transforming interactions that may prominently contribute to adult T-cell leukemogenesis. Thus, the present invention provides methods and compositions for screening and identifying agents that interfere with transformation.

This application is a continuation of PCT/JP2005/009649, filed May 26, 2005, which claims priority to Japanese Application No. 2004-171883, filed Jun. 9, 2004. The entire contents of these applications are incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to a plug-socket assembly including a plug and a socket that receives and secures the plug. More particularly, the present invention relates to a plug-socket assembly suitable for use as a device for fastening an article. BACKGROUND OF THE INVENTION There is known a fastening device in which a socket is fixed to a wall, for example, and a plug is inserted into the socket and locked therein, thereby attaching to the wall a desired article such as a cover of lighting equipment previously attached to the plug. In order that the plug and the socket shall be surely connected together without play, the rear surface of the forward end head portion of the plug is formed into a slant surface that is sloped or extends radially inward toward the rear end thereof. A locking element fitted to the socket is resiliently pressed against the slant surface radially inward, thereby displacing the plug forward (i.e. drawing the plug into the socket; for example, see Japanese Patent Application Publication No. 2001-182726). In this type of fastening device, however, if an excessive pulling force is applied to the plug, the slant surface of the plug acts to displace the locking element radially outward, which may lead to a situation that the plug undesirably comes out of the socket. SUMMARY OF THE INVENTION An object of the present invention is to provide a plug-socket assembly in which the plug cannot come out of the socket even if an excessive external pulling force is applied to the plug. A plug-socket assembly according to the present invention comprises a socket body having a plug insertion hole, a locking element fitted to the socket body so as to be displaceable in the radial direction of the plug insertion hole, a locking element-actuating member fitted to the outside of the socket body so as to be displaceable in the axial direction of the plug insertion hole, and a resilient member that urges the locking element-actuating member in the axial direction. The plug has a forward end head portion that is slidably inserted into the plug insertion hole of the socket. The forward end head portion has a slant rear surface that is sloped or extends radially inward toward the rear end thereof as viewed in the plug insertion direction. The locking element-actuating member of the socket has a locking element sliding surface provided on the inner side thereof. The locking element sliding surface is sloped or extends radially outward in an urging direction in which the locking element-actuating member is urged by the resilient member. The locking element sliding surface presses and engages the locking element by being urged in the axial direction by the resilient member. The locking element sliding surface of the socket has a first portion that engages the locking element to allow it to project as far as a first position in the plug insertion hole when the plug is not inserted in the plug insertion hole, and a second portion that is spaced apart from the first portion by a predetermined distance in the urging direction of the resilient member. When engaging the second portion, the locking element is displaced to a second position that is radially outward of the first position to allow the forward end head portion of the plug to be inserted into the plug insertion hole beyond the locking element. The locking element sliding surface further has a third portion that is closer to the first portion than the second portion. The third portion presses and engages the locking element that engages the slant rear surface of the forward end head portion of the plug when the forward end head portion of the plug is inserted beyond the locking element. Further, the locking element sliding surface has a fourth portion that engages the locking element at an intermediate position between the second portion and the third portion and that is configured so that even if the locking element applies a radially outward force to the locking element sliding surface, the locking element-actuating member will not be forced to move in a direction opposite to the urging direction. In the plug-socket assembly according to the present invention, if an excessive force is applied to the plug so as to pull it out of the socket, the locking element is moved radially outward by the slant rear surface of the forward end head portion of the plug, causing the locking element-actuating member to move against the urging force of the resilient member. Even if such occurs, when the locking element reaches a position where it engages the fourth portion of the locking element sliding surface, there is no longer any force from the locking element that causes the locking element-actuating member to move in the axial direction. Accordingly, the radially outward movement of the locking element is blocked, and thus the plug is prevented from being undesirably pulled out. To pull the plug out of the socket, the locking element-actuating member is moved against the urging force of the resilient member. By doing so, the plug and the socket can be disengaged from each other. Preferably, the slope between the first portion and the fourth portion is less steep than the slope between the fourth portion and the second portion. The reason for this is as follows. The slope between the first portion and the fourth portion is preferably minimized in order to maximize the radially inward force transmitted from the resilient member to the locking element through the locking element-actuating member to thereby increase the force for drawing the plug into the plug insertion hole. On the other hand, the slope between the fourth portion and the second portion is preferably made steep in order that a small axial displacement of the locking element-actuating member shall allow the locking element to be displaced radially outward to a considerable extent (i.e. in order to minimize the axial length of the locking element-actuating member). In order to allow the plug to be inserted into the plug insertion hole without moving the locking element-actuating member in the axial direction, balls that are displaceable radially outward by the forward end head portion of the plug may be used to be pressed against the slant surface between the fourth portion and the second portion to move the locking element-actuating member in the axial direction, as will be described later. In this regard also, the slope between the fourth portion and the second portion should be made steep to minimize the force required to insert the plug. Specifically, the fourth portion may be formed to extend parallel to the axial direction of the plug insertion hole of the socket. The fourth portion may have a surface configuration facing opposite to the urging direction of the resilient member. The fourth portion may be a recess curved radially outward. As has been stated above, in order to allow the plug to be inserted into the plug insertion hole without moving the locking element-actuating member, the plug-socket assembly may be arranged such that the forward end head portion of the plug is provided with a slant front surface extending radially inward in the plug insertion direction, and radially displaceable balls are provided at a position of the socket body closer to the inlet of the plug insertion hole than the locking element. The slant front surface of the plug engages the balls when the plug is inserted into the plug insertion hole, and displaces the balls radially outward so that the balls engage and press against the locking element sliding surface between the fourth portion and the second portion, thereby displacing the locking element-actuating member in the direction opposite to the urging direction to move the locking element to a position between the fourth portion and the second portion. The slant front surface of the forward end head portion of the plug as inserted presses and engages the locking element in the above-described position, thereby displacing the locking element-actuating member in the axial direction. Specifically, the balls may include first balls provided closer to the inlet of the plug insertion hole than the locking element, and second balls provided closer to the inlet of the plug insertion hole than the first balls. The slant front surface of the plug first engages the second balls when the plug is inserted into the plug insertion hole, and displaces the second balls radially outward so that the second balls engage and press against the locking element sliding surface between the fourth portion and the second portion, thereby displacing the locking element-actuating member in the direction opposite to the urging direction. Subsequently, the slant front surface engages the first balls and displaces them radially outward so that the first balls engage and press against the locking element sliding surface between the fourth portion and the second portion, thereby displacing the locking element-actuating member in the direction opposite to the urging direction. Finally, the slant front surface engages the locking element and displaces it radially outward so that the locking element engages and presses against the locking element sliding surface between the fourth portion and the second portion, thereby displacing the locking element-actuating member in the direction opposite to the urging direction, and thus allowing the locking element to engage the second portion. The plug may have at the rear end thereof a flange extending in the radial direction. The flange can clamp and secure a desired member between itself and the rear end of the socket body in a state where the locking element is pressed and engaged with the slant rear surface of the forward end head portion of the plug as inserted into the plug insertion hole. The desired member may be connected and secured to the plug so as to be attached by inserting and connecting the plug into the socket. Preferably, the socket body is provided with a flange extending radially outward so that the forward end of the locking element-actuating member, as viewed in the urging direction in which it is urged by the resilient member, engages the flange when the plug is not inserted. The reason for this arrangement is to prevent the locking element-actuating member from hitting the first balls or the second balls when the locking element-actuating member is released after it has been pulled back by a manual operation and then pushed back by the resilient member. In the plug-socket assembly according to the present invention, when the plug is inserted into the socket, the locking element engages the slant rear surface of the forward end head portion of the plug, and at this time, the slanted locking element sliding surface of the locking element-actuating member is engaged with the locking element, and the pressing force of a resilient member, e.g. a spring, is applied to the locking element, thereby applying drawing force to the plug in the plug insertion direction. By so doing, the plug is locked to the socket without play. In addition, even if an excessive pulling force is applied to the plug, the locking element sliding surface will not be displaced to such an extent as to release the locking element, which might otherwise occur in the prior art, but allows the locking element to remain in the engaging position with the forward end head portion of the plug, whereby the plug can be prevented from being pulled out of the socket. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of the plug-socket assembly according to the first embodiment of the present invention. FIG. 2A is a view for explaining the operation of the plug-socket assembly according to the first embodiment, which shows the way in which the sleeve is retracted by a manual operation to insert the plug, thereby allowing the balls serving as the locking element to be displaced radially outward, so that the forward end head portion of the plug inserted pushes the balls aside and is inserted further inside the plug insertion hole. FIG. 2B is a view for explaining the operation of the plug-socket assembly according to the first embodiment, which shows the way in which the plug is further inserted from the position shown in FIG. 2A , and when the forward end head portion has passed the balls serving as the locking element, the sleeve is released, so that the sleeve is returned rightward by the compression spring, and the slant inner surface (sliding surface) of the socket engages the balls and displaces them radially inward, causing the balls to engage the slant rear surface of the forward end head portion of the plug. FIG. 2C is a view for explaining the operation of the plug-socket assembly according to the first embodiment, which shows the way in which a rightward pulling force acts on the plug that is in the position shown in FIG. 2B , and the force is transmitted to the sleeve through the balls, causing the sleeve to move leftward, so that the horizontal fourth portion at an intermediate part of the slant inner surface (sliding surface) engages the balls to prevent transmission of leftward force to the sleeve. FIG. 3 is a schematic cross-sectional view as seen from the line III-III in FIG. 1 , showing an example of arrangement of the balls. FIG. 4A is a fragmentary longitudinal sectional view of the sleeve in the first embodiment of the plug-socket assembly. FIG. 4B is a fragmentary longitudinal sectional view of a sleeve having a sliding surface similar to that shown in FIG. 4A but modified. FIG. 4C is a fragmentary longitudinal sectional view of a sleeve having another modified sliding surface. FIG. 5 is a longitudinal sectional view of the plug-socket assembly according to the second embodiment of the present invention. FIG. 6 is a schematic cross-sectional view as seen from the line VI-VI in FIG. 5 , showing an example of ball arrangement. FIG. 7 is a schematic cross-sectional view as seen from the line VII-VII in FIG. 5 , showing an example of ball arrangement. FIG. 8 is a schematic cross-sectional view as seen from the line VIII-VIII in FIG. 5 , showing an example of ball arrangement. FIG. 9A is a view for explaining the operation of the plug-socket assembly according to the second embodiment, which shows a state before the plug is inserted. FIG. 9B shows a state where the insertion of the plug has been started, so that the forward end head portion of the plug has engaged the second balls and begun to move the sleeve leftward. FIG. 9C shows a state where the insertion of the plug has proceeded, so that the forward end head portion of the plug has begun to engage the first balls. FIG. 9D shows a state where the first balls have engaged the sliding surface of the sleeve by being pushed radially outward by the forward end head portion of the plug, and thus have begun to displace the sleeve leftward. FIG. 9E shows a state where the balls serving as the locking element have begun to engage the sliding surface of the sleeve by being pushed radially outward. FIG. 9F shows a state where the balls serving as the locking element have been engaged with the forward end head portion of the plug to engage the second portion of the sliding surface of the sleeve, thereby allowing the forward end head portion of the plug to be further inserted. FIG. 9G shows a state where the forward end head portion of the plug has been inserted beyond the balls serving as the locking element, and the compression spring has displaced the balls radially inward through the sleeve, causing the ball to engage the slant rear surface of the forward end head portion of the plug. DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the plug-socket assembly according to the present invention will be explained with reference to FIGS. 1 to 4A . In the following description, the term “axial direction” means a “direction along the longitudinal axis of the plug insertion hole” or a direction parallel thereto, and the term “radial direction” means a “direction extending radially” from the “axial direction”. FIG. 1 is a longitudinal sectional view of a first embodiment of a plug-socket assembly 10 . FIGS. 2A to 2C are views for explaining the operation of the plug-socket assembly 10 . FIG. 3 is a schematic cross-sectional view as seen from the line III-III in FIG. 1 . FIG. 4A is a fragmentary longitudinal sectional view of a sleeve. As shown in FIG. 1 , the plug-socket assembly 10 includes a plug 20 and a socket 30 that receives and secures the plug 20 . The socket 30 has a socket body 31 having a plug insertion hole 311 , and a locking element (assuming the form of balls in the illustrated example; hereinafter referred to simply as “balls”) 32 fitted to the socket body 31 so as to be displaceable in the radial direction of the plug insertion hole 311 . The socket 30 further has a locking element-actuating member (assuming the form of a sleeve in the illustrated example; hereinafter referred to simply as “sleeve”) 33 fitted to the outside of the socket body 31 so as to be displaceable in the axial direction of the plug insertion hole 311 , and a resilient member (assuming the form of a compression coil spring in the illustrated example; hereinafter referred to simply as “compression spring”) 34 that urges the sleeve 33 toward an inlet 313 of the plug insertion hole 311 . The socket 30 is fixed to a desired place, e.g. a wall W, with a bolt B or the like. An annular space 341 is formed between the inner periphery of the sleeve 33 and the outer periphery of the socket body 31 , and the compression spring 34 is installed in the space 341 and compressed by a stop ring 35 secured to the socket body 31 . The compression spring 34 urges the sleeve 33 to abut against a stopper flange 314 provided at the end of the plug insertion hole 311 closer to the inlet 313 . The socket body 31 is provided with ball receiving holes 315 radially extending through the socket body 31 . The balls 32 are received in the ball receiving holes 315 so as to be displaceable in the radial direction. As shown in FIG. 3 , the ball receiving holes 315 are provided at a plurality of equally spaced positions (4 positions in this embodiment) along the circumferential direction. The ball receiving holes 315 are tapered radially inward of the socket body 31 to prevent the balls 32 from falling off. The balls 32 are substantially in contact with a sliding surface 332 of the sleeve 33 (described later) and project radially inward of the socket body 31 when the plug 20 is not inserted in the socket 30 (see FIG. 1 ). The plug 20 has a forward end head portion 21 that is slidably inserted into the plug insertion hole 311 of the socket 30 . The plug 20 further has a rear end flange 22 and a reduced-diameter portion 23 located between the forward end head portion 21 and the rear end flange 22 . The forward end head portion 21 has a slant front surface 211 and a slant rear surface 212 , which extend radially inward toward the front and rear ends, respectively, of the forward end head portion 21 , and a flat surface 213 located between the slant front surface 211 and the slant rear surface 212 . As shown in FIGS. 1 and 4A , the sleeve 33 of the socket 30 is provided on the inner side thereof with a locking element sliding surface (i.e. a sliding surface that is in sliding contact with the balls 32 ; hereinafter referred to simply as “sliding surface”) 332 . The sliding surface 332 is sloped or extends radially outward in the urging direction in which the sleeve 33 is urged by the compression spring 34 . The sliding surface 332 of the sleeve 33 of the socket 30 is located at a position where it is substantially in contact with the balls 32 when the plug 20 is not inserted in the plug insertion hole 311 ( FIG. 1 ). The sliding surface 332 engages the balls 32 at a first portion P 1 ( FIGS. 4A and 1 ), thereby causing the balls 32 to project into the plug insertion hole 311 by a predetermined amount. To insert the plug 20 into the plug insertion hole 311 , an operator displaces the sleeve 33 leftward ( FIG. 2A ), as viewed in FIGS. 1 and 2 , so that the balls 32 are displaced radially outward by the slant front surface 211 of the forward end head portion 21 of the plug 20 inserted into the plug insertion hole 311 , and the flat surface 213 of the forward end head portion 21 is inserted beyond the balls 32 . That is, in the illustrated example, the sliding surface 332 has a second portion P 2 ( FIGS. 4A and 2A ) for allowing the balls 32 to be displaced radially outward as stated above. The operator releases the sleeve 33 when the forward end head portion 21 of the plug 20 has been inserted beyond the balls 32 . Consequently, the sleeve 33 is displaced rightward by the compression spring 34 , and the sliding surface 332 presses and engages the balls 32 at a third portion P 3 located between the first portion P 1 and the second portion P 2 ( FIGS. 4A and 2B ), thus causing the balls 32 to press and engage the slant rear surface 212 of the forward end head portion 21 of the plug 20 . In this state, the plug 20 is drawn into the plug insertion hole 311 by the urging force of the compression spring 34 applied thereto through the balls 32 and the slant rear surface 212 . In the illustrated example, a plate-shaped article 40 is clamped between the flange 22 at the plug rear end and the stopper flange 314 of the socket 30 and firmly held without play by the drawing force acting on the plug 20 . The sliding surface 332 has a fourth portion P 4 extending horizontally between the second portion P 2 and the third portion P 3 ( FIG. 4A ). The fourth portion P 4 is intended to act as follows. When an external pulling force is applied to the plug 20 , the sleeve 33 is displaced leftward by the balls 32 pressed radially outward by the slant rear surface 212 of the plug forward end head portion 21 . At this time, when the balls 32 come in engagement with the fourth portion P 4 ( FIG. 2C ), there is no longer leftward force applied to the sleeve 33 from the balls 32 through the sliding surface 332 . Thus, the sleeve 33 is prevented from being further displaced leftward. That is, the fourth portion P 4 prevents the pulling out of the plug 20 . FIGS. 4B and 4C show modifications of the fourth portion P 4 of the sliding surface 332 . That is, the fourth portion P 4 in FIG. 4B is a recess that is curved radially outward. The fourth portion P 4 in FIG. 4C is a slant surface facing opposite to the urging direction of the compression spring 34 . These fourth portions P 4 are adapted so that when the balls 32 engage either of the fourth portions P 4 , force acting in the direction opposite to the urging direction of the compression spring 34 will not be transmitted to the sleeve 33 from the balls 32 . Thus, the fourth portions P 4 have an action similar to the above-described action of preventing the plug 20 from being pulled out undesirably, which is performed by the fourth portion P 4 shown in FIG. 4A . To unlock the plug 20 from the socket 30 , the sleeve 33 is forced to move leftward against the urging force of the compression spring 34 by a manual operation, for example. By doing so, the plug 20 can be readily disengaged from the socket 30 . A second embodiment of the plug-socket according to the present invention will be explained with reference to FIGS. 5 to 9 . FIG. 5 is a longitudinal sectional view of the second embodiment of the plug-socket assembly 10 . FIG. 6 is a schematic cross-sectional view as seen from the line VI-VI in FIG. 5 . FIG. 7 is a schematic cross-sectional view as seen from the line VII-VII in FIG. 5 . FIG. 8 is a schematic cross-sectional view as seen from the line VIII-VIII in FIG. 5 . FIG. 9 is a view for explaining the operation of the plug-socket assembly 10 according to the second embodiment. The basic arrangement of the plug-socket assembly 10 is substantially the same as that of the foregoing first embodiment. Therefore, only the points in which the second embodiment differs from the first embodiment will be explained below. In the plug-socket assembly 10 according to the second embodiment, the socket body 31 has, as shown in FIGS. 5 to 7 and 9 , first and second sleeve-actuating balls 32 a and 32 b (see FIGS. 5 and 7 ) for displacing the sleeve 33 in addition to the above-described balls 32 serving as the locking element. The first and second sleeve-actuating balls 32 a and 32 b are provided closer to the inlet 313 of the plug insertion hole 311 than the balls 32 . More specifically, the first sleeve-actuating balls 32 a are located closer to the plug insertion hole inlet than the balls 32 . The second sleeve-actuating balls 32 b are located even more closer to the plug insertion hole inlet than the balls 32 . The first sleeve-actuating balls 32 a are circumferentially spaced from the balls 32 by a required angle, as shown in FIGS. 6 and 7 , so as not to interfere with the balls 32 . When the plug 20 is inserted into the plug insertion hole 311 ( FIG. 9A ), the slant front surface 211 of the plug 20 first engages the second sleeve-actuating balls 32 b and displaces them radially outward ( FIG. 9B ) so that the second sleeve-actuating balls 32 b engage and press against the sliding surface 332 at a position between the fourth portion P 4 and the second portion P 2 , thereby displacing the sleeve 33 in the direction opposite to the urging direction of the compression spring 34 ( FIG. 9C ). Subsequently, the slant front surface 211 of the plug 20 engages the first sleeve-actuating balls 32 a ( FIG. 9D ) and displaces them radially outward ( FIG. 9E ) so that the first sleeve-actuating balls 32 a engage and press against the sliding surface 332 at a position between the fourth portion P 4 and the second portion P 2 , thereby displacing the sleeve 33 in the direction opposite to the urging direction of the compression spring 34 . Finally, the slant front surface 211 of the plug 20 engages the balls 32 serving as the locking element and displaces them radially outward ( FIG. 9F ) so that the balls 32 engage and press against the sliding surface 332 at a position between the fourth portion P 4 and the second portion P 2 , thereby displacing the sleeve 33 in the direction opposite to the urging direction. Consequently, the balls 32 engage the second portion P 2 to allow the flat surface 213 of the forward end head portion 21 of the plug 20 to be inserted into the plug insertion hole 311 beyond the balls 32 . When the flat surface 213 of the forward end head portion 21 of the plug 20 has been inserted beyond the balls 32 , the sleeve 33 is pressed and displaced rightward by the urging force of the compression spring 34 , causing the balls 32 to press and engage the slant rear surface 212 of the forward end head portion 21 of the plug 20 . Thus, the plug 20 is forced to be drawn into the plug insertion hole 311 , thereby being connected and locked. In the plug-socket assembly according to this embodiment, the plug can be inserted without moving the sleeve leftward in advance. That is, by simply inserting the plug, the sleeve is moved to allow the plug to be inserted so as to be connected ( FIG. 9G ). Although some embodiments of the plug-socket assembly according to the present invention have been described above, the present invention is not necessarily limited to these embodiments but can be modified in a variety of ways without departing from the scope of the invention set forth in the appended claims. For example, the plug-socket assembly according to the second embodiment has the first and second sleeve-actuating balls for moving the sleeve 33 leftward. In other words, these sleeve-actuating balls are provided to move the sleeve as far as a position where the portion of the sliding surface between the second portion and the fourth portion radially is aligned with the balls 32 serving as the locking element. Therefore, only either the first or second sleeve-actuating balls may be used to move the sleeve so that the sliding surface and the balls 32 are radially aligned with each other as stated above. Further, in the foregoing embodiments, a plate-shaped article is arranged to be clamped between the flange provided at the rear end of the socket and the flange provided at the rear end of the plug. The arrangement may, however, be such that the article is attached directly to the plug by some means instead of being clamped as stated above. In such a case, the flange at the rear end of the plug is arranged to abut against the rear end of the socket, whereby the flanges at the plug rear end and the socket rear end can be firmly secured to each other without play by the force applied by the compression spring to the plug to draw it into the plug insertion hole. Accordingly, the article can be attached even more surely. Although in the foregoing embodiments, the socket is fixed to a wall, for example, the arrangement may be such that the plug is fixed to the wall and an article to be attached is secured to the socket, thereby attaching the article to the wall. The plug-socket assembly according to the present invention is usable not only to attach a desired article to a wall or the like but also to serve in a plug-socket assembly type connector to prevent disconnection of the plug and the socket that might otherwise be caused by an excessive external force unexpectedly applied to the connected plug and socket.

An object of the present invention is to provide a plug/socket assembly in which the plug will never pull out of the socket even if an excessive pull-out force is applied to the plug. A plug/socket assembly ( 10 ) comprises a plug ( 20 ) and a socket ( 30 ) for receiving and fixing the plug ( 20 ) therein. The socket ( 30 ) includes a socket main body ( 31 ) having a plug insertion hole ( 311 ), balls ( 32 ) which are provided with the socket main body ( 31 ) in a radially displaceable manner with respect to the plug insertion hole ( 311 ), a sleeve ( 33 ) which is mounted over the outer surface of the socket main body ( 31 ) and is displaceable along the axial direction of the plug insertion hole ( 311 ), and a compression spring ( 34 ) for urging the sleeve ( 33 ) along the axial direction toward the inlet port ( 313 ) of the plug insertion hole. The inner surface of the sleeve is provided with a slide surface ( 332 ). The slide surface has first to fourth regions (P 1 -P 4 ). The fourth region (P 4 ) is shaped such that with an external pull-out force being applied to the plug, even if the balls apply a radially outward force to the slide surface, no leftward force to push back the sleeve will be produced.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a National Phase Entry of International Patent Application PCT/CA2007/000194 filed Feb. 9, 2007 and claims the benefit of U.S. provisional patent application U.S. Ser. No. 60/771,455 filed Feb. 9, 2006. FIELD OF THE INVENTION The present invention relates to medicinal compositions, particularly to combinations of botanical extracts for promoting cardiovascular health. BACKGROUND OF THE INVENTION Cardiovascular disease (CVD), including coronary heart disease, atherosclerosis, stroke, myocardial infarction, sudden death syndrome, is the number one cause of death in most developed countries all over the world. Also, in developing countries, the prevalence of CVD is on the increase and appears to be linked to people adopting a more Westernized (North American) diet (high fat) and lifestyle (sedentary). Elevated circulating cholesterol levels, in particular low-density-lipoprotein cholesterol (LDL-cholesterol) levels, have been well established as one of the major risk factors for the development and progression of CVD. A high level of circulating triglycerides is also a critical risk factor in the increased incidence of CVD. Accordingly, reducing total cholesterol and/or triglyceride levels is advised to high risk patients to reduce cardiovascular-related risk factors that are known and demonstrated to be associated with a higher incidence of morbidity and mortality. Subjects with obesity, diabetes and hyperlipidemia are three major subgroups of the population that are adversely affected by high cholesterol and triglyceride levels. To date, it is known that plant sterols/stanols and their various analogues can reduce circulating blood cholesterol concentration by inhibiting dietary and biliary cholesterol absorption in the intestine. Red Yeast Rice supplements lower blood cholesterol through inhibiting the activity of the rate-limiting enzyme, HMG-CoA reductase that essentially governs cholesterol biosynthesis in mammals. Berberine was most recently reported to be able to lower blood cholesterol through enhancing cholesterol clearance by increasing LDL-receptor mediated cholesterol clearance. These three types of bioactive compounds (berberine, plant sterols/stanols, and Red Yeast Rice) work through distinct mechanisms. Presently available products have been demonstrated to work via different mechanisms and achieve the expected results to certain degree; however, the efficacy of presently available products is limited and/or is accompanied by side effects. Statin drugs reduce blood cholesterol through suppressing the activity of HMG-CoA reductase, the rate-limiting enzyme in cholesterol synthesis, but this class of compounds has little or no effect on lowering triglycerides. The major drawback of statin or statin-like compounds is that the synthesis of an important mitochondrial enzyme called Q10 is inhibited, depending on HMG-CoA reductase to be intact and functional. Blockage of HMG-CoA reductase by statins causes reduced coenzyme Q10 levels and this is thought to underlie the cause of a number of statin-associated muscle-related myopathies reported, such as muscle soreness, muscle weakness, muscle tenderness, intense muscle pain, peripheral neuropathy and muscle protein breakdown called rhabdomylosis and may underlie other side effects that are dependent on the presence of normal physiological levels of coenzyme Q10. In particular, rhabdomylosis can be both a serious and a life threatening side effect clearly associated with the use of statin drugs where the muscle breakdown causes major organ damage to both the liver and kidney that has resulted in many reported deaths. The all-cause discontinuation rate of statin use was about 10% and discontinuation because of adverse events was about 4%. Plant sterols and their different analogues inhibit cholesterol absorption and thus reduce cholesterol concentration in the plasma. However, when blood cholesterol concentration is reduced through the inhibition of cholesterol absorption, cholesterol synthesis increases simultaneously as a compensation mechanism to counteract the reduced absorption of dietary and biliary cholesterol. Plant sterols and their different analogues have not previously been shown to have any significant effect in reducing serum triglyceride levels. A recent discovery of a botanical bioactive alkaloid compound berberine, contained in Chinese Huanglian, goldenseal, or goldthread, lowers cholesterol levels through increasing LDL-receptor mediated cholesterol clearance. SUMMARY OF THE INVENTION It has now been found that a blood lipid lowering agent that functions through a same mechanism as berberine and a blood lipid lowering agent that functions through a different mechanism than berberine act synergistically to improve blood lipid profiles. Such improvements may be manifested, for example, in lowering blood lipids such as total cholesterol (T-C), low-density-lipoprotein cholesterol (LDL-C) or non-high-density-lipoprotein cholesterol (nonHDL-C), and/or triglycerides (TG), and/or in increasing the ratio of high-density-lipoprotein cholesterol (HDL-C) to LDL-C or nonHDL-C. Blood lipid modulations (e.g. the lowering effects) of the two administered in combination are more than the sum of the two administered separately. Thus, in one aspect of the invention, there is provided a blood lipid level lowering composition comprising a blood lipid lowering agent that functions through a same mechanism as berberine, and a blood lipid lowering agent that functions through a different mechanism than berberine. In a second aspect of the invention, there is provided a use of a blood lipid lowering agent that functions through a same mechanism as berberine and a blood lipid lowering agent that functions through a different mechanism than berberine for lowering blood lipid levels in a mammal. In a third aspect of the invention, there is provided a use of a blood lipid lowering agent that functions through a same mechanism as berberine and a blood lipid lowering agent that functions through a different mechanism than berberine for manufacturing a medicament for lowering blood lipid levels in a mammal. In a fourth aspect of the invention, there is provided a commercial package comprising a blood lipid lowering agent that functions through a same mechanism as berberine and a blood lipid lowering agent that functions through a different mechanism than berberine together with instructions for use in lowering blood lipid levels in a mammal. In a fifth aspect of the invention, there is provided a method comprising administering a blood lipid lowering agent that functions through a same mechanism as berberine and a blood lipid lowering agent that functions through a different mechanism than berberine to a mammal to result in the lowering of blood lipid levels. In a sixth aspect of the invention, there is provided a use of a blood lipid lowering agent that functions through a same mechanism as berberine for controlling weight of a mammal. The blood lipid lowering agent that functions through a same mechanism as berberine (hereinafter referred to as “BBR”) may be from a naturally occurring source or from a synthetic or semi-synthetic source. BBR in a naturally occurring source may be used “as is”, for example, plant material containing the BBR may be used directly. BBR from any source may be subject to one or more isolation or concentration steps (e.g. extraction, crystallization, filtration) to provide a purer and/or more concentrated form of the BBR. Preferably, BBR is used as a crude extract from a natural source, as a concentrated extract from a natural source, as a partially purified extract from a natural source, or in a substantially pure form from a natural, synthetic or semi-synthetic source. BBR may be available commercially from a number of suppliers. BBR may comprise, for example, berberine, one or more berberine derivatives or analogs, one or more pharmacologically acceptable salts thereof, or a mixture thereof. Berberine is an isoquinoline alkaloid of formula (I): Berberine, berberine derivatives or analogs, salts thereof or mixtures thereof may be found in a variety plants, for example Coptis chinensis rhizomes (huanglian, coptis , goldthread), goldenseal, goldthread, Phellodendron amurense bark, Berberis sargentiana, Berberis thunbergii, Berberis vulgaris (Barberry), Berberis aquifolium (Oregon grape), Hydrastis Canadensis (goldenseal), and Berberis aristata (tree turmeric). A recent paper demonstrated that a berberine mixture from goldenseal is more effective than pure berberine chloride alone. Berberine, berberine derivatives or analogs, and salts thereof may be prepared synthetically or semi-synthetically by a variety of chemical and/or enzymatic methods known in the art, for example, as described in United States patent publication 2006/0223838 published Oct. 5, 2006, the disclosure of which is herein incorporated by reference. In one embodiment, the BBR comprises berberine, one or more pharmacologically acceptable salts of berberine or a mixture thereof. Preferred pharmacologically acceptable salts of berberine include, for example, acid addition salts, e.g. chlorides, sulfates, carbonates, phosphates, citrates and acetates. Acid addition salts may be produced by reacting berberine with an appropriate acid. The blood lipid lowering agent that functions through a different mechanism than berberine (hereinafter referred to as “BLLA”) may be, for example, a plant sterol (phytosterol), a plant stanol (phytostanol), a statin, an isoflavone, a natural product containing one or more of the above and/or other blood lipid lowering agents, a derivative thereof or a mixture thereof. In particular, a plant sterol, a plant stanol, an ester of a plant sterol, an ester of a plant stanol or a mixture thereof provide surprisingly synergistic effects when used in conjunction with BBR. Plant sterols comprise alcoholic derivatives of cyclopentanoperhydrophenanthrenes. Plant stanols are saturated forms of the sterols. Some representative examples of plant sterols are beta-sitosterol, campesterol and stigmasterol. Some representative examples of plant stanols are sitostanol and campestanol. Particularly preferred esters of plant sterols or plant stanols are esters with unsaturated fatty acids, for example omega-3 fatty acids (e.g. docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), eicosapentaenoic acid (EPA) and alpha-linolenic acid (ALA)), and esters with any other acids that are suitable for consumption and/or that benefit health (e.g. ascorbic acid). Plant sterols and plant stanols are found in legumes, fruits, vegetables, trees and other plants as well as in fungi and other microorganisms. Plant material containing plant sterols and/or stanols may be used directly, or the plant sterols and/or stanols may be extracted from the plant material and used in a more purified and/or concentrated form. Preferably, plant sterols and plant stanols are extracted from plant or other phytosterol/phytostanol-containing materials. Some examples of plant materials include, for example, soybean oil, tall (pine tree) oil, wood pulp, leaves, nuts, vegetable oils, corn and rice. Plant sterols and plant stanols are available commercially from a number of suppliers. Some natural products contain a variety of BLLAs. For example, Red Yeast Rice contains several different naturally-occurring statins, including lovastatin, which are naturally produced during the fermentation process involved with producing Red Yeast Rice. However, the active lipid lowering components in Red Yeast Rice are not solely statins since the amount of statins obtained from Red Yeast Rice consumption is much lower than the dose of statin drug. The lipid lowering effect of Red Yeast Rice is more likely a result of the combination of lovastatin with other different statins and isoflavones found in Red Yeast Rice extracts. In addition, Red Yeast Rice is a fermented rice product that has been used in Chinese cuisine and as a medicinal food to promote blood circulation for centuries, without significant side effects that occurs after statin drug supplementation. Blood lipid levels may include, for example, triglyceride (TG) levels, total cholesterol (T-C) levels and non-high-density-lipoprotein cholesterol (nonHDL-C) levels (e.g. very low-density lipoprotein cholesterol (VLDL-C) levels, intermediate-density lipoprotein cholesterol (IDL-C) levels and/or low-density-lipoprotein cholesterol (LDL-C) levels). Compositions, uses and methods of the present invention may lower one or more of these levels in the blood. The lowering of blood lipid levels may be measured in whole blood, blood plasma and/or blood serum. BBR and BLLA are used in amounts effective to provide a daily dose of the combination of ingredients that lowers blood lipid levels. For example, the daily dose of each ingredient may in some cases be 5 mg or more per kg of body weight of a subject. In other cases, doses of each ingredient of 10 mg or more per kg of body weight may be appropriate. In yet other cases, doses of each ingredient of 50 mg or more per kg of body weight may be appropriate. For an 80 kg subject, a dose of each ingredient of 10 mg or more per kg of body weight is about 0.8 grams or more of each ingredient per day. Daily dosages can be given all at once in a single dose or can be given incrementally in several smaller dosages. Thus, the composition of the present invention can be formulated such that the recommended daily dose is achieved by the administration of a single dose or by the administration of several smaller doses. BBR and BLLA may be used for any suitable length of time to reduce blood lipid levels in the subject. Preferably, BBR and BLLA are used for at least two weeks. Longer periods of usage can provide greater reduction in blood lipid levels and are envisaged as continued use of all known lipid control therapeutic approaches is required to effectively control or maintain lower lipid levels in the long term. For example, discontinuation of statin therapy results in blood lipid profiles returning to pre-intervention levels. BBR and BLLA may be formulated in a dosage form. Dosage forms include powders, tablets, capsules, softgels, solutions, suspensions, emulsions and other forms that are readily appreciated by one skilled in the art. The compositions may be administered orally, parenterally, intravenously or by any other convenient method. Oral administration is preferred. BBR and BLLA may be administered simultaneously or within a short period of time of one another. Preferably, BBR and BLLA are administered simultaneously. If they are administered within a short period of time of one another, the period time should not be so long that the synergistic effect of BBR and BLLA is not realized. BBR and BLLA may be formulated together with other pharmacologically acceptable ingredients typically used in the nutraceutical and/or pharmaceutical compositions, for example antiadherents, binders (e.g. starches, sugars, cellulose, hydroxypropyl cellulose, ethyl cellulose, lactose, xylitol, sorbitol and maltitol), coatings (e.g. cellulose, synthetic polymers, corn protein zein and other polysaccharides), disintegrants (e.g. starch, cellulose, cross-linked polyvinyl pyrrolidone, sodium starch glycolate and sodium carboxymethyl cellulose), fillers/diluents (e.g. water, plant cellulose, dibasic calcium phosphate, vegetable fats and oils, lactose, sucrose, glucose, mannitol, sorbitol and calcium carbonate), flavors and colors, glidants, lubricants (e.g. talc, silica, vegetable stearin, magnesium stearate and stearic acid), preservatives (e.g. vitamin A, vitamin E, vitamin C, selenium, cysteine, methionine, citric acid, sodium citrate, methyl paraben and propyl paraben), antioxidants, sorbents, sweeteners, and mixtures thereof. BBR and BLLA may also be admixed with a food or beverage and taken orally in such a manner. Fortified foods and beverages may be made by adding BBR and BLLA during the manufacturing of the food or beverage. Alternatively, the consumer may add BBR and BLLA to the food or beverage near the time of consumption. Each ingredient may be added to the food or beverage together with the other ingredients or separately from the other ingredients. Examples of foods and beverages are, but not limited to, cereals, snack bars, dairy products, fruit juices, powdered food and dry powder beverage mixes. BBR and BLLA may be packaged together in a commercial package together with instructions for their use. Such packages are known to one skilled in the art and include, for example, bottles, jars, blister packs, boxes, etc. BBR and BLLA may be used to treat or reduce the chance of contracting or the progression of a number of diseases or conditions in a subject. Diseases or conditions include, for example, cardiovascular disease, hyperlipidemia, atherosclerosis, coronary heart disease, angina, cerebrovascular disease, stroke, overweight or obesity, diabetes, insulin resistance, hyperglycemia, hypertension, arrhythmia, diseases of the central nervous system, diseases of the peripheral nervous system and inflammation. BBR and BLLA are particularly effective at preventing cardiovascular diseases, for example, coronary heart disease, atherosclerosis, stroke, arrhythmia, myocardial infarction and sudden death syndrome. BBR and BLLA may also be used to control weight in a subject. Subjects are humans and animals with blood circulatory systems, particularly mammals, for example, humans, dogs, cats, horses and rodents (e.g. hamsters, mice and rats). Without being held to any particular mechanism of action, synergy between BBR and BLLA is thought to arise by affecting two or more blood lipid control mechanisms to achieve a blood lipid-lowering efficacy greater than the additive effect. BBR and BLLA also provide an anti-inflammatory effect that provides additional health benefits and protection, especially to the cardiovascular system. In addition to the synergistic effect, there is a reduction in side effect profile compared to targeting a single mechanism. For example, BBR and BLLA may simultaneously affect three independent pathways to synergistically lower serum cholesterol levels, lower triglycerides and reduce or down-regulate chronic inflammatory mechanism. Circulating cholesterol concentration is a function of input from absorption (dietary and biliary cholesterol) and de novo synthesis relative to clearance through hepatic and non-hepatic removal mechanisms as well as cholesterol elimination through excretion. There are three major pathways involved in controlling cholesterol homeostasis in the human body. Many of the available natural products that lower body cholesterol target a single distinct pathway and either show limited efficacy or require a high dose level to control cholesterol. Currently there is a high consumer demand for a novel product that can significantly reduce cholesterol levels at a reasonable daily dose and without causing significant side effects. Embodiments of the present invention can meet this demand. Further features of the invention will be described or will become apparent in the course of the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more clearly understood, embodiments thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which: FIG. 1 is a graph depicting effect of berberine chloride and plant stanols on circulating cholesterol levels in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks (for each lipid parameter, values with different superscripts (a, b, c or d) are significantly different); FIG. 2 is a graph depicting effect of berberine chloride and plant stanols on plasma triglyceride concentration in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks (values with different superscripts (a or b) are significantly different); FIG. 3 is a graph depicting percent changes of plasma cholesterol and triglyceride concentration in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols; FIG. 4 is a graph depicting effect of berberine chloride and plant stanols on liver cholesterol concentration in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks (values with different superscripts (a, b or c) are significantly different); FIG. 5 is a graph depicting effect of berberine chloride and plant stanols on the weekly body weight in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks; FIG. 6 is a graph depicting effect of berberine chloride and plant stanols on average daily feed intake in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks; FIG. 7 a is a graph depicting effect of berberine chloride and plant stanols on intestinal ABCG5 mRNA expression in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks (values with different superscripts (a or b) are significantly different); FIG. 7 b is a graph depicting effect of berberine chloride and plant stanols on intestinal ABCG8 mRNA expression in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks (values with different superscripts (a or b) are significantly different); FIG. 8 a is a graph depicting effect of berberine chloride and plant stanols on liver HMG-CoA reductase mRNA expression in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks (values with different superscripts (a or b) are significantly different); FIG. 8 b is a graph depicting effect of berberine chloride and plant stanols on liver CYP7A1 mRNA expression in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks; and, FIG. 8 c is a graph depicting effect of berberine chloride and plant stanols on liver CYP27A1 mRNA expression in hamsters fed an atherogenic control diet and the atherogenic control diet supplemented with berberine chloride and/or plant stanols for 4 weeks. DESCRIPTION OF PREFERRED EMBODIMENTS An objective of the following examples was to show that a combination of BBR and BLLA results in a synergistic improvement in blood lipid profile than each intervention on its own, toward positive health benefits to the cardiovascular system, cerebrovascular vasculature, liver, and body weight. Materials: Table 1 lists materials used in the following examples. TABLE 1 Material Source Berberine chloride (BBRCl) Sigma-Aldrich Co., purity >98% Plant stanols (PS) Forbes-Medi Tech Inc., purity >92%* Casein MP Biomedicals Corn starch MP Biomedicals Sucrose MP Biomedicals Cholesterol MP Biomedicals Male Golden Syrian Hamsters Charles River Co. Male Sprague-Dawley rats Charles River Co. *Plant stanols (PS) consist of 10% campestanols and 82% sitostanols, with overall 92% of plant stanols. Example 1 This example provides data for the combination of berberine chloride (BBRCI) with plant stanols (PS) to improve blood lipid profiles toward positive health benefits to the cardiovascular system, cerebrovascular system, vasculature, liver, and body weight. A controlled, four week animal study was performed to compare and contrast the effects of three interventional strategies on blood cholesterol and triglyceride levels. Four randomized groups of 15 male Golden Syrian hamsters were fed isocaloric diets as follows: Control a semi-synthetic casein-corn starch-sucrose diet that contained 0.15% (w/w) cholesterol and 5% (w/w) fat BBRCI control diet containing 100 mg/kg·d of BBRCI PS control diet containing 1% (w/w) PS BBRCI+PS control diet containing 100 mg/kg·d BBRCI and 1% (w/w) PS BBRCI and PS were introduced into the diet by blending. The primary endpoint at the end of the study was to determine the effects of each intervention on circulating blood lipids including total cholesterol (T-C), high-density-lipoprotein cholesterol (HDL-C), nonHDL-C (which is indicative of LDL-C levels) and triglyceride (TG) profiles. All lipids were measured by the standard enzymatic method. The hamster has been established as a good model for studying human cholesterol metabolism and was used to examine the effects of BBRCI and plant stanols each alone and in combination on circulating blood lipid levels. As well, tissues were collected to determine the associated biochemical and molecular mechanisms that are activated, induced or augmented by the experimental interventions tested. Male Golden Syrian Hamsters were purchased from Charles River Co. housed individually in cages for two weeks prior to the commencement of the study. During this adjustment period, animals were fed with regular rodent chow diet with free access to both food and water. A total of 60 hamsters were weighed and randomly assigned to one of four groups of 15 animals each. Animals are subjected to a temperature-controlled environment with a 12:12 h light/dark cycle. Each group was fed with one of the four isocaloric experimental diets for a 4 week period. A preliminary study demonstrated that the addition of BBRCI to the chow does not induce a taste aversion effect as a food switch from the control diet to one containing 100 mg/kg BBRCI did not change the food intake. During the course of the experiment, animals were weighed weekly and food consumption was determined on a daily basis over the course of the experiment. At the conclusion of the study all animals were anaesthetized with isoflurane and killed by decapitation. Blood samples were collected into tubes containing ethylenediaminetetraacetic acid (EDTA). Red blood cells and plasma were separated and stored at −80° C. until further analysis. Plasma was analyzed for total cholesterol, HDL-C and TG concentrations, for which results are reported below. NonHDL-C was calculated by subtracting HDL-C from total cholesterol. FIGS. 1-3 and Table 2 represent the effects of BBRCI and PS alone or in combination on blood cholesterol and triglyceride levels. Values are means±SD, n=15. Data were analyzed by one-way ANOVA followed by Tukey test if significance was detected. A significant difference was indicated by a p<0.05. The results obtained strongly support that BBRCI and the combination of BBRCI with plant stanols (for this example) induces a beneficial effect on blood lipid profiles (see FIGS. 1-3 and Table 2). The results showed a novel and very important finding that dietary supplementation of BBRCI and plant stanols acted synergistically to lower circulating TG levels (see FIG. 2 ), whereas neither BBRCI (100 mg/kg·d) alone nor plant stanols (1% (w/w)) alone showed any significant reduction of TG levels (BBRCI reduced TG by only 4% and PS reduced TG by 11%). When BBRCI and PS were combined together, plasma TG levels in this group of 15 animals decreased by an average of 36%. Moreover, both materials showed significant effects in lowering T-C and nonHDL-C levels (see FIG. 1 ). TABLE 2 T-C HDL-C nonHDL-C HDL-C/nonHDL-C TG Concentration (mg/dl) Control 217 ± 21 a 119 ± 26 a 92 ± 17 a 1.35 ± 0.46 b 339 ± 137 a BBRCI 169 ± 20 b 100 ± 17 b 66 ± 14 b 1.60 ± 0.58 b 326 ± 111 a PS 152 ± 14 c  99 ± 18 b 51 ± 21 c 2.21 ± 1.34 ab 297 ± 58 a BBRCI + PS 125 ± 11 d  89 ± 15 b 34 ± 11 d 3.10 ± 1.82 a 215 ± 68 b % difference from Control Control   0   0   0  0   0 BBRCI −21.9 −16.2 −28.2  19  −3.9 PS −29.8 −17.2 −45.0  64 −10.6 BBRCI + PS −42.5 −25.4 −63.2 130 −36.6 In terms of converting the data to a more conventional reporting format where the % change of blood total and sub-fraction of cholesterol levels relative to control is calculated and presented, it was found that BBRCI reduced T-C by 22% and nonHDL-C by 28% while plant stanols reduced T-C and nonHDL-C by 30% and 45%, respectively. The combination of both materials lowered T-C by 42% and nonHDL-C by 63% (see FIG. 3 ). BBRCI and PS tended to improve the ratio of HDL-C to nonHDL-C. When BBRCI and PS were supplemented simultaneously in the diet, the ratio of HDL-C to nonHDL-C was improved significantly through a synergistic action mode. Histopathological testing and examination of gross and microscopic examination of thin sections of the various organs were conducted by a certified pathologist. There were no significant changes in the appearance or weight of brain, lung, heart, spleen and kidney. However, the livers of control animals were observably yellowish and heavier than those of animals treated with BBRCI or plant stanols, or the combination of either. Table 3 summarizes the effect of BBRCI and plant stanols on the percent tissue weight relative to body weight. For each tissue weight to body weight parameter in Table 3, values with different superscripts (a or b) are significantly different. The results suggest beneficial effects to the liver and liver function as BBRCI and PS alone and especially BBRCI and PS in combination markedly reduced the appearance of fatty liver, and significantly lowered organ weight compared to the livers of the control animals. TABLE 3 Brain Heart Lung Liver Spleen Right kidney Control 0.81 ± 0.05 0.38 ± 0.04 0.52 ± 0.08 5.0 ± 0.04 a 0.12 ± 0.02 0.34 ± 0.02 BBRCI 0.83 ± 0.06 0.36 ± 0.03 0.54 ± 0.06 4.4 ± 0.4 b 0.11 ± 0.01 0.32 ± 0.03 PS 0.79 ± 0.06 0.37 ± 0.04 0.51 ± 0.07 4.6 ± 0.4 a 0.12 ± 0.01 0.33 ± 0.02 BBRCI + PS 0.81 ± 0.07 0.36 ± 0.03 0.54 ± 0.06 3.9 ± 0.3 b 0.11 ± 0.02 0.33 ± 0.02 FIG. 4 shows the effect of BBRCI and PS alone and in combination the cholesterol content in the liver. Dietary supplementation of BBRCI and PS either alone or combined together dramatically reduced cholesterol concentration in the liver of hamsters. This observation, together with lower liver weight, implies that either BBRCI or PS or combination of either can be used to treat fatty liver. During the course of the experiment, data were obtained with regard to food consumption and bodyweight so that the dose of BBRCI was maintained on a mg/kg basis as the animals grew over the 4 weeks experimental period. Data showed that the body weight and food intake were not immediately affected by the switch from the control diet to any of the three test diets used (BBRCI alone, PS alone, or BBRCI/PS combination, see FIGS. 5-6 ). Analysis of the data showed an unexpected trend toward reduced body weights after two weeks of feeding with BBRCI alone and after 3 weeks of feeding with BBRCI+PS combination (see FIG. 5 ). These results indicate that BBRCI and the combination of BBRCI and PS may be useful in weight control in addition to the beneficial effects of lipid lowering. This may have important implications on weight control, healthy weight management strategies, and body composition (increase lean body mass) in humans and animals. Similarly, during the early segments of the experiment the daily food intake was not affected by BBRCI until after 3 weeks (see FIG. 6 ). Thereafter, significant differences in food intake was observed from days 22-25 but this effect disappeared during days 25-28 as a small surgical intervention was performed on each animal on day 25 on the neck area of the animal, which reduced food consumption in each treatment. Surgical intervention was performed to permit intravenous injection of a stable isotope cholesterol tracer. The experimental results described above show that a powerful synergistic effect of BBRCI and PS on TG reduction exists. Dramatic reductions in serum T-C and nonHDL-C occurred when BBRCI and PS were combined at the levels used in these experiments. Experiments were also conducted to determine the effect on the expression of genes associated with cholesterol in the liver and intestine. Total RNA was extracted and mRNA was converted to cDNA. The mRNA expression was measured by real-time PCR with four repeats and calculated as relative expression in reference to internal control of a housekeeping gene for each sample. Table 4 and FIGS. 7 a - 7 b summarize the effect of BBCI and PS alone or in combination on intestinal ABCG5 ( FIG. 7 a ) and ABCG8 ( FIG. 7 b ) mRNA expression. BBRCI and PS alone did not affect ABCG5 and ABCG8 mRNA expression. However, when they were administered simultaneously, the mRNA expression of both genes was significantly reduced in a synergistic mode. The function of ABCG5 and ABCG8 in the intestine is to transport cholesterol out of enterocytes and back to the intestine for elimination via the feces. Recent observations have demonstrated that the mRNA expression of ABCG5 and ABCG8 is closely and positively associated with blood cholesterol levels. When a strong action occurs on cholesterol reduction, the expressions of these two genes are down-regulated. The observation of our study (Example 1) has provided a strong support to the synergistic action of BBRCI and PS on cholesterol reduction. TABLE 4 ABCG5 ABCG8 Control 2.36 ± 0.72 a 1.30 ± 0.25 a BBRCl 2.37 ± 0.70 a 1.33 ± 0.45 a PS 1.97 ± 0.72 ab 0.99 ± 0.32 ab BBRCl + PS 1.55 ± 0.29 b 0.69 ± 0.17 b Table 5 and FIG. 8 a summarize the effect of BBRCI and PS alone or in combination on liver HMG-CoA reductase. BBRCI and PS alone did not affect HMG-CoA reductase mRNA expression. However, when they were combined, the mRNA expression of HMG-CoA reductase was increased by 7-fold. HMG-CoA reductase is a rate-limiting enzyme in cholesterol biosynthesis. A large body of evidence has indicated that cholesterol synthesis is altered reciprocally with cholesterol absorption. When a strong action occurs on cholesterol reduction through inhibiting cholesterol absorption, cholesterol biosynthesis is increased as compensatory response to the cholesterol loss due to the reduced absorption. The powerful synergistic action of BBRCI and PS on HMG-CoA reductase mRNA expression implies that the combination of these materials may act synergistically to reduce blood cholesterol, possibly by inhibiting cholesterol absorption. Table 5, FIG. 8 b and FIG. 8 c summarize the effect of BBRCI and PS on the mRNA expression of CYP7A1 and CYP27A1 in the liver. BBRCI and PS alone tended to increase mRNA expression of both genes. CYP7A1 and CYP27A1 are two rate-limiting enzymes controlling bile acid synthesis, which is one mechanism through which the body removes cholesterol by converting it into bile acids. When BBRCI and PS were combined, a synergistic action appeared to happen. This result implies that BBRCI and PS reduce blood cholesterol by affecting cholesterol catabolism in the liver through a synergistic action mode. TABLE 5 HMG-CoA reductase CYP7A1 CYP27A1 Control 1.01 ± 0.19 b 1.03 ± 0.44 1.06 ± 0.27 BBRCl 0.98 ± 0.10 b 1.30 ± 0.66 1.27 ± 0.31 PS 1.34 ± 0.48 b 1.32 ± 0.67 1.40 ± 0.37 BBRCl + PS 7.52 ± 2.60 a 1.83 ± 1.05 1.60 ± 0.75 There is a balance between synthesis and clearance of cholesterol in the body. Despite efficient clearance of cholesterol, the body will compensate to try to maintain a certain baseline cholesterol level. In Example 1, the strong action of the combination of BBRCI and PS may have reduced cholesterol levels to a near minimum or base level. In such a case, no observable synergistic effect is expected even though a synergistic action was implied by the gene expressions. For this reason, a synergistic action on cholesterol reduction was not detected in Example 1 as a maximum or near maximum reduction in blood lipids was achieved. Accordingly, if a sufficiently higher blood cholesterol level is achieved by increasing dietary cholesterol intake and/or if sufficiently less BBRCI and/or PS are used in the diet, a synergistic action of cholesterol reduction should be observable. Examples 2 and 3 below describe such studies. Example 2 In this example, a controlled, five week animal study was performed. A total of 48 male Golden Syrian hamsters were randomized into 4 groups of 12 and fed isocaloric diets as follows. Hamster husbandry, living and feeding conditions were similar to that used for Example 1. Control a semi-synthetic casein-corn starch-sucrose diet that contained 0.25% (w/w) cholesterol BBRCI control diet containing 100 mg/kg·d of BBRCI PS control diet containing 1% (w/w) PS BBRCI+PS control diet containing 100 mg/kg·d BBRCI and 1% (w/w) PS One objective of this example was to determine the effects of each intervention on circulating blood lipids including total cholesterol (T-C), high-density-lipoprotein cholesterol (HDL-C), nonHDL-C (which is indicative of LDL-C levels) and triglyceride (TG) profiles when hamsters were fed a diet containing a higher concentration of cholesterol, for example, 0.25% by weight in the diet. Table 6 summarizes the effect on blood lipid levels (values are means±SD, n=12). Data were analyzed by one-way ANOVA followed by Tukey test if significance was detected. A significant difference was indicated by a p<0.05. Values with different superscripts (a, b or c) within a specific lipid group are significantly different. Results of this study indicate that BBRCI and PS synergistically decrease blood TG levels. BBRCI and PS did not show a synergistic action on cholesterol reduction. However, as discussed in Example 1, the reason for this may still be that the very strong cholesterol lowering action of combined BBRCI and PS was maximized under the experimental conductions (i.e. baseline levels of cholesterol were reached). Animals in Example 2 were heavier and supplemented with a higher level of dietary cholesterol in a longer feeding period than those in Example 1. As can be seen in Example 3 below, a synergistic effect on cholesterol lowering is observed when the level of cholesterol is sufficiently high and the amount of PS supplemented in the diet is reduced by 50%. The ratio of HDL-C to nonHDL-C tended to increase by BBRCI or PS alone. The combination of BBRCI and PS significantly increased the ratio of HDL-C to nonHDL-C. TABLE 6 HDL-C/ T-C HDL-C nonHDL-C nonHDL-C TG Concentration (mg/dl) Control 287.2 ± 39.3 a 91.5 ± 20.1 ab 195.2 ± 46.1 a 0.51 ± 0.20 b 550.3 ± 224.9 a BBRCI 264.7 ± 49.8 a 93.1 ± 27.1 ab 173.5 ± 66.5 a 0.66 ± 0.41 ab 549.1 ± 225.3 a PS 180.2 ± 28.2 bc 77.2 ± 13.7 b 103.4 ± 27.2 b 0.84 ± 0.44 ab 369.6 ± 137.3 ab BBRCI + PS 160.9 ± 23.8 c 76.3 ± 15.7 b  84.6 ± 25.3 b 1.00 ± 0.49 a 310.3 ± 127.3 b % difference from Control Control   0   0   0  0   0 BBRCI  −7.8  1.7 −11.1 29  −0.2 PS −37.3 −15.6 −47.0 65 −32.8 BBRCI + PS −44.0 −15.6-16.6 −56.7 96 −43.6 Table 7 summarizes the effect on tissue weight to body weight ratio (values are means±SD). Data were analyzed by one-way ANOVA followed by Tukey test when a significant treatment effect was detected. A significant difference was indicated by a p<0.05. Values with different superscripts (a, b or c) for each tissue weight to body weight parameter within a tissue group are significantly different. The average liver weight was statistically lower in the PS group compared to the Control group but was not significantly lower when comparing the BBRCI group with Control. The combination of BBRCI and PS (BBRCI+PS), however, reduced the average liver weight in a strong, statistically significant, and synergistic manner compared to liver weights in the BBRCI and PS groups. The BBRCI+PS induced effect on the average liver weight was also significantly lower than in Control. TABLE 7 Heart Liver Right kidney Control (n = 12) 0.37 ± 0.05 5.03 ± 0.29 a 0.35 ± 0.04 BBRCl (n = 12) 0.37 ± 0.03 4.67 ± 0.38 ab 0.35 ± 0.03 PS (n = 12) 0.37 ± 0.03 4.56 ± 0.37 b 0.36 ± 0.03 BBRCl + PS (n = 12) 0.35 ± 0.04 3.94 ± 0.33 c 0.35 ± 0.03 Example 3 In this example, a controlled, five week animal study was performed. Four randomized groups of 12 or 6 male Golden Syrian hamsters were fed isocaloric diets as follows. The dosage of PS was reduced from 1% to 0.5% (w/w) in the diet. Hamster husbandry, living and feeding conditions were similar to that in Example 1. Control a semi-synthetic casein-corn starch-sucrose diet that contained 0.25% (w/w) cholesterol BBRCI control diet containing 100 mg/kg·d of BBRCI PS control diet containing 0.5% (w/w) PS BBRCI+PS control diet containing 100 mg/kg·d BBRCI and 0.5% (w/w) PS One objective of this example was to determine the effects of each intervention on circulating blood lipids including total cholesterol (T-C), high-density-lipoprotein cholesterol (HDL-C), nonHDL-C (which is indicative of LDL-C levels) and triglyceride (TG) profiles. Table 8 summarizes the effect on blood lipid levels (values are means±SD, n=12). Data were analyzed by one-way ANOVA followed by Tukey test if significance was detected. A significant difference was indicated by a p<0.05. Values with different superscripts (a, b or c) within a specific lipid group are significantly different. When BBRCI and PS were given to hamsters simultaneously, significant synergistic actions were observed on T-C, nonHDL-C and TG levels. A synergistic action of BBRCI and PS was also observed on the ratio of HDL-C and nonHDL-C. It has been demonstrated by the results of this study that BBRCI and PS act synergistically to reduce blood total cholesterol, nonHDL-C and triglyceride levels. TABLE 8 HDL-C/ T-C HDL-C nonHDL-C nonHDL-C TG Concentration (mg/dl) Control 287.2 ± 39.3 a  91.5 ± 20.1 195.2 ± 46.1 a 0.51 ± 0.20 b 550.3 ± 224.9 a BBRCI 264.7 ± 49.8 a  93.1 ± 27.1 173.5 ± 66.5 ab 0.66 ± 0.41 b 549.1 ± 225.3 a PS 212.1 ± 20.3 b 108.2 ± 19.1 111.2 ± 19.0 bc 1.02 ± 0.37 ab 341.4 ± 121.7 ab BBRCI + PS 164.3 ± 17.5 b  98.5 ± 12.7  65.9 ± 12.3 c 1.56 ± 0.47 a 278.2 ± 89.9 b % difference from Control Control   0  0   0  0   0 BBRCI  −7.8  1.7 −11.1  29  −0.2 PS −26.2 18.3 −43.0 100 −37.9 BBRCI + PS −42.8  7.7 −66.2 206 −49.5 Example 4 In this example, a controlled, six week animal study was performed in a different animal model. Six randomized groups of 10 male Sprague-Dawley rats were fed isocaloric diets as follows. The PS was introduced into the diet by blending and BBRCI was introduced by gavage feeding twice a day. Control a semi-synthetic casein-corn starch-sucrose diet that contained 2% (w/w) cholesterol and 28% (w/w) fat BBRCI-1 control diet containing 100 mg/kg·d of BBRCI PS control diet containing 1% (w/w) PS BBRCI-1+PS control diet containing 100 mg/kg·d BBRCI and 1% (w/w) PS BBRCI-2 control diet containing 200 mg/kg·d of BBRCI BBRCI-2+PS control diet containing 200 mg/kg·d BBRCI and 1% (w/w) PS One objective of this example was to determine the effects of each intervention on plasma cholesterol levels in a different animal model. Table 9 summarizes the effect on blood total cholesterol levels (values are means±SD, n=10). A significant synergistic total cholesterol reduction was seen for the combination of either of two doses of BBRCI and PS. Results of this study demonstrate in a different animal model that BBRCI and PS synergistically reduce blood total cholesterol levels. TABLE 9 T-C (mg/dl) Control 109.4 ± 22.8  BBRCl-1 102.1 ± 30.6  PS 90.0 ± 29.0 BBRCl-1 + PS 67.2 ± 14.8 BBRCl-2 109.1 ± 26.7  BBRCl-2 + PS 83.1 ± 18.1 % difference from Control Control 0 BBRCl-1 −6.7 PS −17.8 BBRCl-1 + PS −38.6 BBRCl-2 −0.3 BBRCl-2 + PS −24.0 Other advantages that are inherent to the structure are obvious to one skilled in the art. The embodiments are described herein illustratively and are not meant to limit the scope of the invention as claimed. Variations of the foregoing embodiments will be evident to a person of ordinary skill and are intended by the inventor to be encompassed by the following claims.

A blood lipid lowering agent that functions through a same mechanism as berberine (e.g. berberine, one or more pharmacologically acceptable salts of berberine or a mixture thereof) and a blood lipid lowering agent that functions through a different mechanism than berberine (e.g. phytosterols, phytostanols, esters thereof or mixtures thereof) act synergistically to improve blood lipid profiles, for example, lowering total cholesterol, LDL-C or nonHDL-C, and triglyceride, and increasing the ratio of HDL-C to nonHDL-C. The two may be used in combination to treat or reduce the chance of contracting cardiovascular disease, hyperlipidemia, atherosclerosis, coronary heart disease, angina, cerebrovascular disease, stroke, overweight or obesity, diabetes, insulin resistance, hyperglycemia, hypertension, arrhythmia, diseases of the central nervous system, diseases of the peripheral nervous system and/or inflammation. The blood lipid lowering agent that functions through a same mechanism as berberine, with or without the blood lipid lowering agent that functions through a different mechanism than berberine, may also be used to control weight.

FIELD OF THE INVENTION [0001] The present invention relates to a method for capturing carbon dioxide from a gaseous mixture containing carbon dioxide, e.g., from the atmosphere, and subsequently using this carbon dioxide for the production of fuel. BACKGROUND OF THE INVENTION [0002] Greenhouse gases include carbon dioxide, methane, nitrous oxide and water vapor. While greenhouse gases occur naturally in the atmosphere, human activities also produce greenhouse gas emissions and are responsible for creating new ones. Carbon dioxide (CO 2 ) is the most common greenhouse gas released by human activities, resulting from the extensive use of fossil fuel (coal, petroleum, natural gas). One of the main challenges modern civilization is facing is the increase of carbon dioxide in the atmosphere, affecting the greenhouse effect and global warming. Another problem arises from the extensive use of fossil fuel thus diminishing the global fuel reserves. [0003] Renewable energy sources, that capture their energy from existing flows of energy, from on-going natural processes, such as sunshine, wind, flowing water, biological processes and geothermal heat flows, can be used for generating electricity, and there is a growing demand for methods of producing fuel using electricity. [0004] Numerous attempts for extracting CO 2 directly from car exhausts or power plants have been made, most of them involving reactions of exhausted gases with organic amine compounds or strong bases like calcium hydroxide or sodium hydroxide. In processes using organic amines, a solution of amine and water is contacted with the gas, whereby the amine and the CO 2 undergo a chemical reaction forming a rich amine that is soluble in the water. The rich amine solution is pumped to a desorber where it is heated, reversing the reaction and releasing pure CO 2 gas. The disadvantage of this method is the fact that organic amine bases are expensive and unstable. [0005] Carbon dioxide and mixtures containing it have been proposed for production of combustible fuels. For example, U.S. Pat. No. 4,140,602 discloses a chemical method for combustible fuel production by converting carbon dioxide in the atmosphere to a carbonate such as an alkali carbonate, following which the recovered carbonate is combined with hydrogen gas to produce combustible fuels e.g. methane and methanol. The method includes the additional step of reacting the alkali carbonate with calcium hydroxide to form calcium carbonate. The disadvantages of this method resides in the use of the strong base compound Ca(OH) 2 , forming CaCO 3 , that requires considerable amount of energy for the thermal release of CO 2 . SUMMARY OF THE INVENTION [0006] The present invention relates to a method for producing combustible fuels from a gaseous mixture containing carbon dioxide, which comprises: (i) capturing CO 2 from said gaseous mixture by means of K 2 CO 3 , thus forming KHCO 3 ; (ii) releasing the CO 2 from said KHCO 3 ; and (iii) subsequently producing fuel from the released CO 2 by reaction with hydrogen. DETAILED DESCRIPTION OF THE INVENTION [0010] The method of the present invention enables the production of combustible fuels, using as preferred starting material the highly available atmospheric carbon dioxide, and returning the CO 2 produced by fuel combustion to the atmosphere, thus maintaining the equilibrium of the CO 2 in the atmosphere. The method is based on well known in the art reactions such as thermal catalytic and electrochemical reactions, utilizing the reversibility of these reactions and carrying out the reverse reaction by modifying the operating pressure and/or the electrical voltage supplied to the process. [0011] The reaction between the CO 2 and K 2 CO 3 in step (i) may be performed by bubbling air in water through an aqueous solution of K 2 CO 3 or by spraying droplets of K 2 CO 3 in aqueous solution into a stream of air. In both methods, the atmospheric CO 2 reacts with the K 2 CO 3 to form KHCO 3 according to the following reaction: K 2 CO 3 +H 2 O+CO 2 →2KHCO 3 [0012] In the next step, CO 2 is released from the KHCO 3 . [0013] In one embodiment of the invention, the CO 2 is released by heating the KHCO 3 to a temperature sufficient to liberate the CO 2 , according to the following reaction, thus recycling the K 2 CO 3 : 2KHCO 3 +Heat→K 2 CO 3 +H 2 O+CO 2 [0014] In another embodiment, the CO 2 is released from the KHCO 3 obtained by an electrochemical process, according to the following reaction: HCO 3 − −e →.OH+CO 2 4(.OH)→2H 2 O+O 2 [0015] The CO 2 obtained in step (ii) is then reacted with hydrogen to produce combustible fuels, such as methane and methanol. [0016] In one embodiment, in which heat source producing very high temperatures is available, the reaction of CO 2 and hydrogen is conducted as a thermal catalytic reaction. One possible thermal catalytic reaction is a reverse operation of methane reforming. In steam methane reforming, methane is brought into contact with (excess) steam at high temperature and pressure, typically 800-1000° C. and 30-40 bar, over a catalyst, to produce a mixture of H 2 , CO and CO 2 . In the industry, the process is usually carried out in fixed bed or fluidized bed membrane reactors, using a Ni as the preferred catalyst, because of its low cost, or a noble metal catalyst such as Ru, Rh, Pd, Ir or Pt. The reverse methane reforming according to the invention is carried in the same type of reactors and using the same catalysts as in steam methane reforming, but using pressures varying according to the characteristics of the specific process, said pressure being always higher than the pressure used for the methane reforming. [0017] In another embodiment, the reaction of CO 2 and hydrogen according to the invention is an electrochemical process, such as a reverse operation of a fuel cell. [0018] A fuel cell is an electrochemical energy conversion device that converts the chemical energy of a fuel, e.g. hydrogen, and an oxidant, e.g. oxygen, to electrical energy and heat, without combustion. The device is similar to a battery but, unlike a battery, the fuel cell is designed for continuous replenishment of the reactants consumed, i.e., the fuel and the oxidant are typically stored outside of the fuel cell and transferred into the fuel cell as the reactants are consumed. In a typical fuel cell, the fuel is consumed at the anode and the oxidizer is consumed at the cathode. There are several types of fuel cells, each using a different chemistry. Fuel cells are usually classified by the type of electrolyte they use, and include phosphoric acid-based, proton exchange membrane, solid polymer, molten carbonate, solid oxide, alkaline, direct methanol, regenerative, zinc-air and protonic ceramic fuel cells. [0019] In a fuel cell, if a hydrocarbon, such as methane, is the fuel, said hydrocarbon is reacted with oxygen obtained by electrolysis of water within the cell, thus forming CO 2 and hydrogen and generating electricity. [0020] According to the present invention, a reverse operation of a fuel cell is carried out whereby electricity is supplied to a fuel cell containing CO 2 , that reacts with hydrogen formed in situ by electrolysis of water, thus producing the desired hydrocarbon, e.g. methane fuel. The electrical voltage supplied to the process is determined based on the characteristics of the specific process performed but it is always higher than the electrical voltage generated in the opposite process, namely, the regular operation of the fuel cell. [0021] In one preferred embodiment, the electrochemical process corresponds to an inverted direct methanol fuel cell (DMFC) and the fuel obtained is methanol. [0022] DMFCs are low-temperature fuel cells operating at temperatures of 30-130° C. and using liquid methanol as the electrolyte, according to the reaction: CH 3 OH+ 3/2O 2 →CO 2 +2H 2 O [0023] The central component of DMFCs is the membrane electrode assembly, composed of membrane, catalyst and diffusion layers. The membrane may be a polymer with acid groups that are capable of splitting off protons and has them migrate through the membrane. The diffusion layer passes the fuels to the catalyst layer and removes the combustion products. In the catalyst layers, the electrochemical reaction takes place, in which chemical energy is converted into electric energy. The catalyst is provided with additives to apply it as a paste on a substrate, and it is usually based on a noble metal, such as platinum and platinum/ruthenium. [0024] According to the present invention, the catalysts used for the reverse operation of the DMFC are the same used in the regular operation mode of the methanol fuel cell, and other parameters such as temperature and electrical voltage supplied to the process are determined based on the characteristics of the specific process performed. [0025] In another preferred embodiment, the electrochemical process corresponds to an inverted molten carbonate fuel cell (MCFC) and the fuel obtained is a hydrocarbon, such as methane. [0026] MCFCs are high-temperature fuel cell operating at temperatures of 600-650° C., and thus can achieve higher fuel-to-electricity and overall energy use efficiencies than low temperature fuel cells. The electrolyte used in MCFCs is an alkali carbonate such as Na 2 CO 3 , K 2 CO 3 , Li 2 CO 3 or combinations thereof, that may be retained in a ceramic matrix, e.g. of LiAlO 2 . In the fuel cell, the alkali carbonates melt into a highly conductive molten salt with carbonate ions providing ionic conduction through the electrolyte matrix. Nickel and nickel oxide are adequate to promote reaction on the anode and cathode, respectively, and expensive catalysts (noble metals) are not required. [0027] The fuel consumed in MCFCs is usually a natural gas, mainly methane, and in this case methane and steam are converted into a hydrogen-rich gas inside the fuel cell stack (a process called “internal reforming”). The overall reaction performed within the cell is: CH 4 +O 2 →CO 2 +2H 2 [0028] According to the present invention, the operating conditions for the reverse operation of the MCFC (temperature and pressure) are similar to these in the regular operation mode of this cell. The exact conditions, as well as the voltage supplied to the process, are determined based on the characteristics of the specific process performed. [0029] The methane or methanol obtained by the method of the invention may later be converted into longer hydrocarbons, using known chemical reactions.

The invention provides a method for producing combustible fuels from a gaseous mixture containing carbon dioxide, which comprises: (i) capturing CO2 from said gaseous mixture by means of K2CO3, thus forming KHCO3; (ii) releasing the CO2 from said KHCO3; and (iii) subsequently producing fuel from the released CO2 by reaction with hydrogen.

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation-in-part of copending application Ser. No. 09/096,867, filed Jun. 11, 1998, and claims the priority of provisional application Ser. No. 60/049,428, filed Jun. 12, 1997. The contents of both applications are incorporated herein by reference. BACKGROUND OF THE INVENTION Xanthan gum is an acidic exopolysaccharide (EPS) normally secreted by X. campestris (Jeanes, A., et al., 1961, J Appl Polymer Sci 5: 519-526), and is useful as an aqueous rheological control agent because it exhibits high viscosity at low concentration, pseudoplasticity, and insensitivity to a wide range of temperature, pH, and electrolyte conditions (see U.S. Pat. Nos. 5,194,386, 5,472,870, 5,279,961, 5,338,841, and 5,340,743, the contents of each of which are incorporated herein by reference). The genes that code for its synthesis are gumB through M(Capage, M. A., et al., 1987, WO87/05938; Vanderslice, R. W., et al., 1989, the contents of which are incorporated by reference; Genetic engineering of polysaccharide structure in Xanthomonas campestris. In: Biomedical and biotechnological advances in industrial polysaccharides, V. Crescenzi, I. C. M. Dea, S. Paoletti, S. S. Stivala, and I. W. Sutherland, eds, pp 145-156, Gordon and Breach Science Publishers, New York). A different source of commercially significant and functionally diverse biopolymers is the genus Sphingomonas (Pollock, T. J., 1993, J Gen Microbiol 139: 1939-1945). Different organisms of this genus secrete a variety of different strain-specific exopolysaccharides For example, one species secretes Gellan®, while others secrete welan, rhamsan, S-88 or other polysaccharides (Moorhouse, R., 1987, Structure/property relationships of a family of microbial polysaccharides. In: Industrial polysaccharides: genetic engineering, structure/property relations and applications. M Yalpani, ed, pp 187-206, Elsevier Science Publishers B.V. Amsterdam). We refer to this group of polymers as "sphingans," after the common genus, because they also have common carbohydrate backbone structures (-x-glucose-glucuronic acid-glucose-; where x is either L-rhamnose or L-mannose) with distinct side chains. (See U.S. patent application Ser. Nos. 08/592,874, filed Jan. 24, 1996, and 08/377,440, filed Jan. 24, 1995, the contents of each of which are hereby incorporated by reference). The structure for sphingan S-88 is shown in FIG. 1. The organization and DNA sequence of 23 genes (FIG. 2) that direct the synthesis of sphingan S-88 have been described (Yamazaki, M, et al., 1996, J Bacteriol 178: 2676-2687). The commercial production of highly viscous xanthan gum and other bacterial polysaccharides is a complex biosynthetic and process-engineering problem (Kennedy, J. F. et al., 1984, Prog Industrial Microbiol 19: 319-371). The sugar substrate is important primarily because the sugar affects productivity, but the cost of the sugar can also be significant. Currently, xanthan gum is produced by supplying X campestris with corn syrup, sucrose or starch. Yet, three to four typical cheese factories can provide enough low-value lactose-containing waste whey to satisfy all of the existing worldwide demand for xanthan production. A recombinant strain that can stably convert lactose into xanthan gum in amounts equal to the conversion of glucose is disclosed in U.S. Pat. Nos. 5,434,078, and 5,279,961, the contents of each of which are incorporated herein by reference. It is desired to improve the methods of the production of xanthan gum to achieve more cost-effectiveness, convenience, more desired product qualities and greater production efficiency. A problem encountered with xanthan gum produced by conventional methods, is that it is contaminated with a cellulase which can be very disadvantageous in commercial applications where xanthan is mixed with or contacts cellulosic polymers. The result is deterioration of the cellulosic polymers. Methods are known for the treatment of xanthan gum which has been separated from fermentation broths to remove the cellulase contaminant. However, these treatments require processing of the xanthan gum and add to the expense and overall complexity of the process. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the repeating subunit structures of xanthan gum and sphingan S-88. FIG. 2 is a schematic map of the X campestris gum and Sphingomonas S88 sps genes. SUMMARY OF THE INVENTION We have discovered new recombinant bacteria for the production of exopolysaccharides. In addition, we have discovered a method for making the recombinant bacteria and making an exopolysaccharide from the bacteria by submerged aerobic fermentation of the bacteria utilizing a sugar substrate. The recombinant bacteria of the present invention are able to produce exopolysaccharides and utilize sugar substrates which are utilizable by the bacteria from which the recombinant bacteria were derived. In addition, the exopolysaccharide obtained from the inventive bacteria exhibit improved, more desirable or different properties from the exopolysaccharide produced by the non-recombinant bacteria from which the recombinant bacteria was derived. In addition, we have discovered a novel xanthan gum product which as obtained in the broth exhibits reduced cellulase contamination. It is an object of the invention to provide a method of producing bacterial exopolysaccharides by fermentation from sugar substrates that the bacteria which the exopolysaccharides are native to cannot utilize. It is a further object of the invention to provide a method of increasing the yield of a non-native bacterial exopolysaccharide produced in a recombinant bacterial host. It is another object of the invention to produce xanthan gum by fermentation from whey waste, a byproduct of cheese production. Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned from practice of the invention. The objects and advantages may be realized and attained by means of the methods particularly pointed out in the appended claims. To achieve the objects and in accordance with the purposes of the present invention, methods for the production of non-native bacterial exopolysaccharides in recombinant bacterial hosts are set forth. Specifically, we have discovered that the yield of a non-native bacterial exopolysaccharide produced in a recombinant bacterial host can be increased by inactivating the native polysaccharide production in the bacterial host. DEFINITIONS As used herein: "Non-recombinant bacterial host strain" means a bacterial strain which does not contain foreign genetic material. "Recombinant bacterial host strain" means the non-recombinant bacterial host strain into which foreign genetic material has been introduced and retained. This strain is sometimes referred to herein as the "recipient" or "recipient strain." "Foreign genetic material" means segments of the genome of a strain of bacteria which are different from those in the recombinant bacterial host strain into which the segment(s) is or is to be introduced. "Glycosyl transferase" means any one of a group of related enzymes which either catalyze the attachment of a sugar-phosphate molecule to the isoprenyl phosphate carrier involved in exopolysaccharide biosynthesis or the attachment of a sugar to sugars previously attached to the isoprenyl phosphate carrier. An "sps gene" means one of several genes which are present in the genomes of species of Sphingomonas bacteria or can be isolated from the Sphingomonas bacteria and which are involved in the biosynthesis of a sphingan exopolysaccharide because they code for enzymes that catalyze chemical reactions in the biosynthetic pathway or because they code for proteins or DNA control sites that modulate the amount of sphingan exopolysaccharide present in the bacterial growth medium. "Non-native exopolysaccharide" means a bacterial exopolysaccharide which is not produced and excreted by a non-recombinant bacterial host strain, but is produced and excreted by a recombinant bacterial host strain obtained from the non-recombinant bacterial host strain.; "Native bacterial producer" means a non-recombinant bacterial strain which produces the desired bacterial exopolysaccharide. A "gum gene" means one of several genes which are present in the genomes of species of Xanthomonas bacteria or can be isolated from the Xanthomonas bacterial and which are involved in the biosynthesis of a xanthan exopolysaccharide because they code for enzymes that catalyze chemical reactions in the biosynthetic pathway or because they code for proteins or DNA control sites that modulate the amount of xanthan exopolysaccharide present in the bacterial growth medium. Examples of two exopolysaccharides , xanthan gum and sphingan S-88 (Jansson, P. E., et al., 1975, Carbohydr Res 45: 275-282, Jansson, P. E., et al., 1986, Carbohydr Res 156: 165-172), are shown by their repeating sugar subunit structures in FIG. 1. The arrows point toward the reducing end of each repeat. For xanthan gum the IP carrier is attached at the reducing end through a phosphodiester linkage to the glucose residue which is lacking the side chain (Ielpi, L., et al., 1993, J Bacteriol 175: 2490-2500). Abbreviations: Glc, glucose; Man, mannose; GlcA, glucuronic acid; Rha, rhamnose; Ac, acetyl ester; and Pyr, acetal-linked pyruvic acid. The position and linkage of the Ac in S-88 is unknown. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a method of producing a bacterial exopolysaccharide from a sugar source which the native bacterial producer of that exopolysaccharide cannot utilize by transforming a bacterial host strain which can utilize the sugar source but does not produce the exopolysaccharide with genes from the native bacterial producer which are necessary for establishing the production of the exopolysaccharide in the bacterial host strain. The bacterial exopolysaccharide can then be produced by fermenting the recombinant bacterial host with the sugar source. For example, the genes gumBCDEFGHIJKL and M from X. campestris strain B1459 were transformed into a specifically mutated Sphingomonas recipient, fermentation of which in the presence of inexpensive waste whey lactose obtained large amounts of secreted xanthan gum which was comparable to that produced by X. campestris strain B 1459. For production of xanthan gum lacking acetyl side groups, the gumF and gumG genes of Xanthomonas can be omitted from the foreign genetic material obtained from Xanthomonas. Similarly, for production of xanthan gum lacking pyruvyl side groups, the gumL gene can be omitted. In the case where the "recombinant bacterial host strain" already expresses a gene function that is necessary for production of the "non-native exopolysaccharide", then that function need not be included in the "foreign genetic material". For example, when foreign genetic material is introduced into Sphingomonas bacteria and the initial step in assembly of the repeat subunit structure of the non-native polysaccharide on the isoprenoid lipid carrier is the transfer of glucose-P to the carrier, then any of several gene functions that carry out the same specific enzymatic reaction can be substituted. For example, in place of the gumD gene of Xanthomonas species on could substitute the spsB gene from Sphingomonas species or the pssA gene from Rhizobium species, or analogous genes from other bacteria. The present invention further provides a method for increasing the yield of a non-native exopolysaccharide produced in a recombinant bacterial host strain by inactivating the exopolysaccharide production native to the bacterial host strain. Preferably, the inactivation is achieved by deletions or mutations in the genome of the bacterial host strain. Most preferably, the deletion or mutation inactivates the activity of a glycosyl transferase. Most preferably, the deletion or mutation inactivates the activity of a glycosyl transferase, a polysaccharide polymerase, a secretory apparatus, or enzymes required for the synthesis of essential nucleotide-sugar precursors. For example, in Sphingomonas, inactivation of one or more of the essential substrate-specific glycosyl transferase enzymes, such as, spsB, Q, K or L, which are required for synthesis of the subunit sugar repeat structure which is attached to the carrier C55-isoprenyl phosphate eliminates synthesis of the polysaccharide produced by Sphingomonas. Likewise, mutations in a polysaccharide polymerase or in a secretion apparatus also eliminate exopolysaccharide production by a native polysaccharide producer. Production of the native polysaccharide can also be eliminated by mutations which inactivate enzymes that are essential for the synthesis of precursor nucleotide-sugars, such as the four enzymes required to synthesize the precursor dTDT-L-rhamnose:RhsA, RhsB, RhsC, or RhsD. The mutations or deletions which eliminate these enzyme or protein activities can either directly inactivate these enzymes by altering the structures and activities of the enzymes or indirectly inactivate the enzymes by blocking or modulating the expression of the genes that code for these enzymes or proteins. The present invention also provides a method for minimizing contaminating cellulase activity in xanthan gum produced by fermentation by fermenting a recombinant Sphingomonas species strain transformed with genes from the genome of X. campestris, which are necessary for establishing the production of xanthan gum in the Sphingomonas species. All of the embodiments use the following bacterial strains, recombinant DNA procedures, and growth media: Strain X59 (ATCC 55298--see U.S. Pat. No. 5,194,386, col. 8-9) is a spontaneous rifampicin-resistant mutant derived from wild type X. campestris B1459 (Thome, L., et al., 1987, J Bacteriol 169: 3593-3600). Cloned DNA segments and site-specific chromosomal deletions are diagramed in FIG. 2. Plasmid XCc8 is a member of a cosmid library (Thorne, L, et al., 1987, J Bacteriol 169: 3593-3600) and was obtained by inserting a segment of about 24 kilobase pairs kbp) of chromosomal DNA from strain X59 into the mobilizable broad-host-range plasmid vector pRK311 (Ditta, G., et al., 1985, Plasmid 13: 149-153). The DNA segment carried by plasmid XC600(gumB-M) was derived from plasmid XCc8 by standard methods of DNA isolation, digestion with restriction endonucleases, and ligation (Maniatis, T., et al., 1982, Molecular cloning: a laboratory manual. Cold Spring Harbor Laboratory, Cold Spring Harbor). The insert in plasmid XC600 spans the NdeI-SalI segment of XCc8 corresponds to nucleotide 919-15400 of the gum sequence in GenBank accession number U22511, shown in Sec. ID No.1 hereof. (GenBank, National Center for Biotechnology Information, National Library of Medicine, Bethesda, Md. 20894, www.ncbi.nlm.gov/web/genbank). Plasmid XC 1483 includes nucleotide 3460 (BamHI) through 7959 (BamHI) (Pollock, T. J., et al., 1994, J Bacteriol 176: 6229-6237). Plasmids S88c1, and S88c3 are members of a cosmid library (Yamazaki, M, et al., 1996, J Bacteriol 178: 2676-2687) that were derived from a partial digestion with SalI enzyme of S88 chromosomal DNA, followed by ligation to the vector pRK311. The nucleotides deleted in strain S88ATn358 include 4485 (BamHI) through 24646 (EcoRI) in the S88 sequence (GenBank accession U51197 Sec. ID No. 2 hereof). Strain S88m265 is defective in spsB (Yamazaki, M., et al., 1996, J Bacteriol 178: 2676-2687). DNA transformation into E. coli, tri-parental conjugal mating of broad-host-range plasmids into Sphingomonas or X. campestris, and selection methods were described (Yamazaki, M, et al., 1996, J Bacteriol 178: 2676-2687). Luria-Bertani and M9 salts are standard media (Pollock, T. J., et al., 1994, J Bacteriol 176: 6229-6237). M9+YE is M9 salts supplemented with 0.05% w/v yeast extract. YM medium contains 3 g Bacto yeast extract, 3 g malt extract, 5 g Bacto peptone, and 10 g D-glucose per liter of deionized water. 1/4 YM-G medium is YM diluted with 3 volumes of water and with no added glucose. The amounts of antibiotics used were as follows: rifampicin, 50 mg L -1 ; streptomycin, 50 mg L -1 ; kanamycin, 50 mg L -1 ; and tetracycline, 6-15 mg L -1 (Sigma Chemical Co.). Low viscosity carboxymethylcellulose (1% w/v final, Sigma Chemical Co.) was mixed with TSA blood agar base (Difco), and then cultures were spotted onto the surface of the medium and grown for 4-7 days at 30° C. Zones of hydrolysis of carboxymethylcellulose were observed by gently flooding the plate with 0.1% (w/v) Congo red dye for 30 min followed by destaining with 1M NaCl for 30 min. The diameters of the zones were then measured to compare the relative cellulase activity of the various cultures. The following chemical and physical analyses of exopolysaccharides were used in the examples: Extracellular xanthan gum or sphingan S-88 was precipitated from liquid culture medium with 2-3 volumes of isopropyl alcohol, and then dried at 80° C. before weighing. Hydrolysis mixtures contained 0.5-5 mg of polysaccharide and 130-260 μM (v/v) trifluoroacetic acid in high performance liquid chromatography (HPLC) water, and were incubated for 16 h at 95° C. The samples were dried under vacuum, resuspended in 100 μl HPLC water, dried again, and finally resuspended in 100 μl of HPLC water. Samples and sugar standards were separated on a CarboPac PA-1 anion-exchange column and the sugar compositions were quantitated with a Dionex DX500 HPLC system as described previously (Clarke, A. J., et al., 1991, Anal Biochem 199: 68-74). Assays for acetyl (Hestrin, S. 1949, J Biol Chem 180: 249-261) and pyruvyl (Duckworth, M, et al., 1970, Chem Ind 23: 747-748) groups have been described. Samples of polysaccharides (10 mg, powdered) were dissolved in 2 ml deionized water at 80° C. for 60 min in glass test tubes with an equal weight of locust bean gum and bromphenol blue dye (100 μg ml -1 ). After cooling for 2 h the tubes were rotated to horizontal for photography. Failure to gel resulted in horizontal movement of the mixed slurry. A sample of commercial xanthan gum (Keltrol, Kelco Company) was used for physical and chemical comparisons. For xanthan-guar mixtures each polysaccharide was dissolved in 100 mM KCl at 0.1% w/v, and solution viscosities were measured at 20-25 ° C. at several rpm with a Brookfield LVTDV-II viscometer and spindle 18. DEPOSITS The following deposits have been made in connection with the present invention: 1. Sphingomonas paucimobilis (ATCC 29837) containing plasmid XCc8 ATCC Designation No. 98479; 2. Sphingomonas strain S88ATn358 containing plasmid XCc8 ATCC Designation 98480. The above deposits were made with the American Type Culture Collection located at 10801 University Blvd., Manassas, Va. 20110-2209m pursuant to the Budapest Treaty for the International Recognition of the Deposit of Microorganisms for the Purposed of Patent Procedure. All restrictions on the availability of the materials deposited will be irrevocably removed upon the issuance of a patent thereon. All other microorganisms and/or DNA segments, plasmids, and the like referred to herein are publicly available from the American Type culture collection in Manassas, Va. EXAMPLE 1 Inter-generic expression of genes coding for polysaccharide biosynthesis Referring to FIG. 2, maps of X. campestris gum and Sphingomonas S88 sps genes, boundaries of specific segments cloned in plasmids, and deletions in bacterial chromosomes are shown. The arrows above the genes indicate the direction of transcription. The horizontal lines indicate the extent of the cloned DNA included in each plasmid with the included genes within parentheses. The dashed lines indicate the regions deleted from mutant chromosomes . The gumB through M genes (GenBank accession U22511) span about 14 kbp and the spsG through urf34 genes (GenBank accession U51197) include about 29 kbp. The original cosmid clones and specific subcloned segments (diagramed in FIG. 2) were transferred by conjugal mating into X. campestris and Sphingomonas recipients. The type of EPS secreted into the medium was determined from the appearance of colonies and liquid cultures, and from the physical properties and carbohydrate compositions of the recovered polysaccharides. As described in Table 1 and the legend, X. campestris X59 (Gum + ), Sphingomonas S88 (Sps + ) and the polysaccharide-negative mutant S88m265 (Sps - ), have readily distinguished colony morphologies and characteristics in liquid culture. From a visual inspection, one can not only determine if any EPS is being secreted, but also whether the EPS is sphingan S-88 or xanthan gum. EPS samples were acid hydrolyzed, and the identity and amounts of monosaccharide(s) were determined. The xanthan gum secreted from X. campestris contained two neutral sugars, with glucose representing about 67% and mannose about 33% of the sum of the peak areas for the neutral sugars on the HPLC chromatograms. By contrast, sphingan S-88 contained about 18% rhamnose, 59% glucose, and 23% mannose. The sugar components distinguished xanthan gum from sphingan S-88. The colonial appearance (Sps + ) and composition of neutral sugars from the polysaccharides secreted by the recipient S88m265 carrying plasmid S88c1 indicated that the plasmid, which carries a normal spsB gene, restored sphingan S-88 synthesis to the mutant. Plasmid XC1483 with the X. campestris gumD gene also restored sphingan S-88 synthesis to S88m265. Of particular interest is that a mixture of neutral sugars composed of about one-fourth sphingan S-88 and three-fourths xanthan gum was obtained when plasmid XCc8, which carries gum genes, was introduced into S88m265. This recombinant strain has all of the genes needed to make both exopolysaccharides in strain S-88. Thus, with the present invention, it is possible to obtain two different exopolysaccharides from the same organism at the same time. TABLE 1______________________________________Sugar compositions of bacterial exopolysaccharides Percent of total Donor Bacterial recipient Recombinant neutral sugarsplasmids and phenotype phenotype.sup.a Rha Glc Man______________________________________-- X. campestries X59 0 67 33 Gum.sup.+ -- Sphingomonas S88 Sps.sup.+ 18 59 23 S88c1 S88m265 (SpsB.sup.-) Sps.sup.+ 19 62 19 XC1483 " Sps.sup.+ 22 61 17 XCc8 " Sps/Gum.sup.+ 7 64 29 S88c3 S88ΛTn358 (Sps.sup.-) Sps.sup.+ 19 63 19 XCc8 " Gum.sup.+ 0 64 36 XC600 " Gum.sup.+ 0 62 37 XC566 S88ΔTm372 (Sps.sup.-) Gum.sup.- XCc8 S88m134 (SpsB.sup.- RhsD.sup.-) Gum.sup.+ XCc8 S. paucimobilis Gum.sup.+ ATCC 29837______________________________________ .sup.a Gum.sup.+ indicates a wildtype X. campestris-like appearance caused by the secretion of viscous xanthan gum, with large (3-5 mm in fou days at 30° C.), shiny, mucoid, lightyellow-colored colonies on solid YM medium and a viscous culture broth in liquid YM medium with nonaggregated cells. Sps.sup.+ indicates a wildtype appearance typical of Sphingomonas strain secreting a capsular sphingan polymer: colonies are opaque to transmitted light, shiny but not viscous, and produce viscous liquid culture broths containing aggregates of cells. By deleting certain sps genes from the S88 chromosome we obtained synthesis in Sphingomonas of xanthan gum alone. Although plasmid S88c3 (sps genes) restored synthesis of sphingan S-88 to the deletion mutant S88ΔTn358, plasmids XCc8 and XC600 (gum genes) caused the synthesis of a polysaccharide that matched the neutral sugar percentages of xanthan, and lacked rhamnose. Plasmid XCc8 caused the synthesis of only xanthan gum in a double mutant of Sphingomonas (S88m134) which has defects in glucosyl-IP transferase (SpsB - ) and in synthesis of the essential dTDP-rhamnose substrate (RfbD - ). We also observed xanthan gum synthesis in the type strain for the S. paucimobilis genus, ATCC 29837, which otherwise does not secrete any polysaccharide. Physical studies on this polysaccharide detailed in Example 3 confirmed that it was xanthan gum. EXAMPLE 2 Detection of gene function in recombinants In order to determine if the acetylase (gumF and G) and pyruvylase (gumL) genes of X. campestris were functioning in Sphingomonas we measured the amounts of each component for samples of the recombinant and commercial xanthan gums. The degree of acetylation for the recombinant sample (S88ΔTn358 with plasmid XCc8) exceeded that for the commercial xanthan gum by a few percent and was similar to the degree of acetylation for xanthan gum made by X. campestris X59 while growing under the same conditions as the recombinant Sphingomonas. The recombinant samples were 4-6% by weight as pyruvate compared to 5-6% for commercial xanthan (Keltrol) and xanthan made by X. campestris X59. EXAMPLE 3 Physical analyses of recombinant xanthan gum Three physical properties of recombinant and commercial xanthan gum were compared. First, the viscosity synergism expected for mixtures of xanthan and guar gums was observed for the recombinant samples (Table 2). Solution viscosities were measured for samples with and without added guar gum. The viscosities of the mixtures of guar gum with either commercial xanthan gum or the recombinant samples were higher than the sum of the viscosities of the unmixed polysaccharides. Second, xanthan gum is unique in forming a rigid gel in the presence of locust bean gum. Rigid gels were formed by mixing locust bean gum with commercial xanthan gum or with any one of three recombinant samples: plasmid XCc8 in either S88m265, S88ΔTn358, or S. paucimobilis ATCC 29837. Third, the viscosity of each recombinant xanthan sample was shear thinning like commercial xanthan gum. These three physical tests confirmed that the EPS secreted by the recombinant Sphingomonas strains was comparable to xanthan gum. TABLE 2______________________________________Viscosity synergism for mixtures of exopolysaccharides and guar gum Viscosity (cp).sup.aEPS EPS alone EPS with guar______________________________________None -- 4 xanthan gum 22 49 X59 27 63 S88m265/XCc8 7 18 S88ΛTn358/XCc8 9 27 ATCC29837/XCc8 7 29______________________________________ .sup.a Centipoise (cp) for spindle 18 at 12 rmp for final concentrations of each polymer at 0.1% in 100 mM KCl at room temperature EXAMPLE 4 Alternative culture conditions The results in Table 3 indicate that the recombinant Sphingomonas strains, in contrast to X. campestris, converted either lactose or glucose to xanthan gum to a similar extent. TABLE 3______________________________________Cell densities and xanthan gum yields for shake flask cultures. Growth medium, temperature, S88ΔTn358 ATCC 29837 and X59 with XCc8 with XCc8sugar substrate A600 mg A600 mg A600 mg______________________________________1/4 YM-G 30° C. glucose 1.1 43 6.0 62 2.9 37 33° C. glucose 0.8 34 4.8 49 2.6 33 30° C. lactose 0.4 16 5.4 67 3.4 39 M9+YE 30° C. glucose 2.4 84 2.1 30 4.9 55 30° C. lactose 0.2 9 2.3 30 6.3 53______________________________________ 1/4 YMG and M9+YE were supplemented with either glucose or lactose to 2% w/v. Culture density was measured as the absorbance at 600 nm. The yield of xanthan gum (mg) is the average for samples of 10 ml taken from two separately inoculated flasks after 48 h (1/4YMG) or 42 h (M9+YE). The cultures were centrifuged to remove cells before precipitation of the polysaccharides with alcohol. Production rates and yields for large scale xanthan gum fermentations are sensitive to temperature and aeration. The highly viscous broth requires considerable stirring and cooling to achieve maximum productivity. Although X. campestris produces xanthan gum optimally at about 28° C., Sphingomonas strains are known to grow at temperatures up to about 37° C. As shown in Table 3, the recombinant Sphingomonas strains grew at 30° C. and 33° C. In the case of recombinant ATCC 29833 with XcC8, the yields of gum were about equivalent to the native gum producer X-59 at both 30° C. and 33° C. in 1/4YM-G media. However, the case of the recombinant S88ΔTn358 with XCc8 in 1/4YM-G media, the yields of gum were significantly above those of the native gum producer X59 at both temperatures. This is an important aspect of the present invention since, as the fermentation is exothermic, a major energy requirement is cooling of the fermentation broth. With the present invention, the fermentation can be carried out at a higher temperature, in the range from about 30 to 33 ° C. This means that less cooling is required and a substantial energy cost savings can be realized with the present invention as compared with the conventional fermentation conditions used for xanthan gum production. EXAMPLE 5 Reduction of cellulase contamination in xanthan gum The presence of contaminating cellulase in xanthan gum is disadvantageous in commercial applications where xanthan is mixed with or contacts cellulosic polymers. As judged by measuring the zones of hydrolysis surrounding cultures spotted onto agar plates containing carboxymethylcellulose, we found that the inventive Sphingomonas recombinants showed less than one-eighth of the cellulase activity observed for X. campestris strain X59. This means that xanthan gum as produced from the inventive strains contains significantly decreased amounts of contaminating cellulase as compared with xanthan gum obtained from X59. As used herein, "as produced" means the xanthan product as obtained directly from the broth without any steps, after-treatments or procedures taken to remove cellulase therefrom. Accordingly, the as produced xanthan gum obtained with the present invention is advantageous since it avoids the increased costs and steps normally required with conventional xanthan product to remove or decrease the cellulase content. EXAMPLE 6 Prophetic Example To Show How to Construct and Use Subsets of the Larger Segment Construction and use of foreign genetic material from the genome of Xanthomonas lacking the acetylase (gumF and gumG), pyruvylase (gumL), or glycosyl transferase (gumD) genes. Three segments of DNA containing the gumBCDE, gumHIJK, and gumM genes can be isolated from the recominant plasmid carrying the XC6000 portion of the Xanthomonas genome. Similarly, two segments containing the gumBC and gumEFGHIJKLM genes can be isolated. The genes can be prepared by cleavage of the XC600 segment with specific restriction endonucleases or by amplification using the polymerase chain reaction, and then purified by electrophoresis through an agarose gel. When the polymerase chain reaction is used the primer segments will contain specific sequences for restriction endonucleases. The three segments will be assembled by DNA ligation as a contiguous set of genes as in a genetic operon and inserted by DNA ligation into a plasmid vector that can be introduced into Sphingomonas. The DNA sequence of the gum region (Genbank number U22511, seq. ID No. 1) provides the positions of the individual gum genes, the available restriction endonuclease sites, and the sequences required to synthesize specific primers for polymerase chain reaction. All of the above-described recombinant DNA methods are routine for one of average skill in this art. The plasmid can be one of several broad host range mobilizable vectors, such as pRK311. Alternatively, the foreign genes can be inserted into the Sphingomonas chromosome by using a vector plasmid which cannot replicate autonomously with Sphingomonas. Alternative DNA sequences can be inserted into the assembled segment to modify or stimulate gene expression, such as, gene regulation sequences, promoter sequences for RNA polymerase, or ribosome binding sequences. By using modifications of these methods, one can assemble different segments lacking any one of or a combination of the gumF, gumG, gumL, or gumD genes, and thereby produce xanthan gum lacking acetyl and/or pyruvyl side groups, or lacking the glycosyl transferase GumD, where a foreign glycosyl transferase gene substitutes for the GumD function. Alternatively, one can inactivate any one of or any combination of the gumF, gumG, gumL or gumD genes by site-specific mutagenesis to alter the specific amino acid sequence fo the proteins. Available methods for this mutagenesis include chemical changes to the DNA sequence or insertions of foreign DNA such as insertion sequences or transposons. It is to be understood that the foregoing examples are exemplary and explanatory only and are not restrictive of the invention. Various changes may be made to the embodiments described above by one of skill in the art without departing from the scope of the invention, as defined by the following claims. __________________________________________________________________________# SEQUENCE LISTING - - - - <160> NUMBER OF SEQ ID NOS: 2 - - <210> SEQ ID NO 1 <211> LENGTH: 16075 <212> TYPE: DNA <213> ORGANISM: Xanthomonas campestris <300> PUBLICATION INFORMATION: - - <400> SEQUENCE: 1 - - ggatccggtt gaggcggtaa caggggattg gcatggcatt gacgaaagcg ga -#gatggccg 60 - - agcgtctgtt cgacgaagtc ggcctgaaca agcgtgaggc gaaggaattc gt -#cgacgcgt 120 - - ttttcgatgt gctgcgcgat gcactggagc agggccgtca ggtgaagttg tc -#gggcttcg 180 - - gcaacttcga tctgcggcgc aagaaccaac ggcccggtcg caatcccaag ac -#cggtgagg 240 - - aaattccgat ctcggccagg acggtggtga ccttccgccc cggccagaaa ct -#caaggaac 300 - - gggtggaggc ttatgctgga tccgggcagt aatcgcgagc taccgccgat tc -#cggccaag 360 - - cgctacttca ccatcggtga ggtgagcgag ctgtgcgacg tcaagccgca cg -#tgctgcgc 420 - - tattgggaaa ccgaatttcc gagcctggag gccagtcaag cggcgcgcaa cc -#gacgctac 480 - - taccagcggc acgatgtcgt gatggtgcgg cagattcgtg gcctgctgta cg -#agcagggt 540 - - tacaccatcg ggggcgcgcg tctgcgtctt gaaggggatg gggccaagag cg -#agtcagcg 600 - - ctgagcaatc agatcatcaa gcaggtgcgc atggagcttg aagaagtcct gc -#agctgctg 660 - - cgacgctagg aaagcgccgc ataaagccgc tataatcgca ggccgcctca gg -#gcgggacg 720 - - caacatcttc ggggtatagc gcagcctggt agcgcactag tctgggggac ta -#gtggtcgt 780 - - cggttcgaat ccggctaccc cgaccaaaca acaggcctac gtcgcaagac gt -#gggccttt 840 - - ttgttgcgtc gcaacatgtc agttcgatgg cattccaggc tatgccacta tg -#cgcaacgg 900 - - catattgcaa ggcggcatat gcaagtcctg tacgcaatta tttcgcggtt ca -#ggctgcta 960 - - caagtcggga tcagcaggcg tccgtaagtg cccggaaacg ctagagttcg ta -#tgctgaga 1020 - - atgacgaccc aggtcacgtt ctcttaacgt cgaggcgacg aacttgaatc aa -#taggccaa 1080 - - cgccgtcaaa aaaatggcgt gttgtgcctt gcgatgtgtt cgttctatgc ca -#tagtgcac 1140 - - tgcaacacgc gattcaacgt tggtcccggc acgcgtcggg atgcaacttc ct -#gtcgtacg 1200 - - ttcgtgctgg cgcctgagcc ggttgaatgc tgcgcgaggt cctgtcccac cc -#aacagagg 1260 - - cagccagcta cacgcatgaa gaaactgatc ggacgactcg tcgcaaggcc tc -#agcctggc 1320 - - tctgctctgc tcgatgtcgc tgggcgcttg cagcaccggc ccggagatgg cg -#tcttcgct 1380 - - gccgcatccg gacccgctgg caatgtccac ggtgcagccc gaataccgtc tt -#gcgccggg 1440 - - cgatctgttg ctggtgaagg tgtttcagat cgacgatctg gagcggcagg tc -#cgcatcga 1500 - - ccagaacggt cacatctcac tgccgttgat tggcgacgtc aaggccgccg gt -#ctgggcgt 1560 - - tggcgaactg gaaaagctgg tcgccgatcg gtatcgcgca ggctacctgc ag -#cagccgca 1620 - - gatttcggta ttcgtgcagg agtccaacgg gcgtcgcgtc acggtcactg gt -#gcggtaga 1680 - - cgagccgggc atctacccgg tgatcggcgc caacctcacc ttgcagcagg cg -#atcgcgca 1740 - - ggccaagggt gtcagcacgg tggcaagccg cggcaacgtg atcgtgttcc gc -#atggtcaa 1800 - - cgggcaaaaa atgattgcgc ggttcgacct gaccgagatc gagaaggggg cc -#aatccgga 1860 - - tcctgagatt tatggcggcg acattgtcgt ggtgtatcgc tcggatgcgc gc -#gtgtggtt 1920 - - gcgcaccatg ctggaactga cccccttggt gatggtgtgg cgcgcttacc ga -#tgagtatg 1980 - - aattcagaca atcgttcctc ttcgtcgcag cggtcatggt catctggaac tg -#gcagatgt 2040 - - cgacttgatg gactactggc gcgccctggt ctcgcagctc tggctgatca tc -#ctgatcgc 2100 - - cgtcggcgcg ctgttgctgg cattcggcat cacgatgttg atgcccgaga ag -#taccgcgc 2160 - - caccagcacc ctgcagatcg aacgtgactc gctcaatgtg gtgaacgtcg ac -#aacctgat 2220 - - gccggtggaa tcgccgcagg atcgcgattt ctaccagacc cagtaccagt tg -#ctgcagag 2280 - - ccgttcgctg gcgcgtgcgg tgatccggga agccaagctc gatcaggagc cg -#gcgttcaa 2340 - - ggagcaggtg gaggaggcgc tggccaaagc cgccgaaaag aatcccgagg cg -#ggtaagtc 2400 - - gctcgattcg cggcaggcga tcgtcgagcg cagcctcacc gatacgttgc tc -#gccgggct 2460 - - ggtggtcgag ccgatcctca actcgcgcct ggtgtacgtc aattacgatt cg -#ccagaccc 2520 - - ggtgctggcc gccaagatcg ccaatacgta cccgaaggtg ttcatcgtca gc -#acccagga 2580 - - acgccgcatg aaggcgtctt cgtttgcgac acagtttctg gctgagcgcc tg -#aagcagtt 2640 - - gcgcgagaag gtcgaagact ctgaaaagga tctggtctcg tattcgaccg aa -#gagcagat 2700 - - cgtgtcggtt ggcgatgaca agccctcgct gcctgcgcag aatctgaccg at -#ctcaatgc 2760 - - gttgctggca tccgcacagg acgcccggat caaggccgag tcagcttggc gg -#caggcttc 2820 - - cagtggcgat ggcatgtcat tgccgcaggt gttgagcagc ccgctgattc aa -#agcctgcg 2880 - - cagcgagcag gtgcgtctga ccagcgagta ccagcagaaa ctgtcgacct tc -#aagccgga 2940 - - ttacccggag atgcagcgcc tcaaggcgca gatcgaagag tcgcgtcgtc ag -#atcaatgg 3000 - - cgaagtcatc aatatccgtc agtcgctgaa ggcgacctac gacgcctccg tg -#catcagga 3060 - - gcagctgctc aacgaccgca tcgccggtct gcggtccaac gagctggatc tg -#cagagccg 3120 - - cagcatccgc tacaacatgc tcaagcgcga cgtcgacacc aaccgccagc tc -#tacgatgc 3180 - - gctcctgcag cgctacaagg aaatcggcgt ggcgagcaac gtgggcgcca ac -#aacgtgac 3240 - - catcgtcgat accgcagacg tgcctacgtc taagacttcg ccgaaactca aa -#ttgaacct 3300 - - cgcgttgggc ctgatctttg gcgtattcct gggcgtggct gtggctctgg tt -#cgctactt 3360 - - cctgcgtggg ccttctccga ggtcgcggtt gaactgacat cgtgatgttg ca -#aaacgatg 3420 - - gttaattgaa gtgacaactg attcagcgtg gaaaaggtgg gatcccgtaa gg -#tgcgggct 3480 - - ccctcgtttg aaggtttgtc tctgttgaaa caaagggctg tcgtgcgatc tg -#gggtcggt 3540 - - aggtattacc gcggtgatcg gacgacagga tgattgaaag ctcgcgtgcg at -#tcgtatgt 3600 - - tcccccgcat gcgccgtatc gagtttggag gacatcccca tgcttttggc ag -#acttgagt 3660 - - agcgcgactt acacgacatc ctcgccgcga ttgttgtcca aatattcggc ag -#ccgccgac 3720 - - ctggtcctgc gcgtgttcga cctgaccatg gtcgttgcgt ccggactgat cg -#cataccgc 3780 - - atcgttttcg gtacctgggt acccgcagcg ccttatcggg tcgcgattgc ga -#caacgttg 3840 - - ttgtactcgg tgatctgctt tgcgttgttc ccgctgtatc gcagctggcg cg -#gccgtgga 3900 - - ttgctgagtg agctggtggt gctgggtggc gcattcggcg gtgtgtttgc gc -#tgttcgcg 3960 - - gtgcatgccc tgatcgtgca ggtgggtgag caggtgtcgc gtggttgggt cg -#gcctgtgg 4020 - - ttcgtcggcg gcctggtgtc gctggtggcc gcacgcacct tgctgcgtgg ct -#tcctcaat 4080 - - cacctgcgca cgcagggcgt ggatgtccag cgtgtggtgg tagtgggcct gc -#gtcatccg 4140 - - gtgatgaaga tcagtcatta cctgagccgt aatccctggg tcggcatgaa ca -#tggttggc 4200 - - tatttccgca cgccgtacga tctggcggtg gccgaacagc gccagggtct gc -#cgtgcctg 4260 - - ggtgatcccg atgagctgat cgagtacctg aagaacaacc aggtggagca gg -#tgtggatc 4320 - - tcgctgccgc ttggcgagcg cgaccacatc aagcagctgc tgcagcgcct gg -#atcgctac 4380 - - ccgatcaacg tgaagctggt gcccgacctg ttcgacttcg gcctgttgaa cc -#agtctgcc 4440 - - gagcagatcg gcagcgtgcc ggtgatcaac ctgcgtcagg gtggcgtgga tc -#gtgacaac 4500 - - tacttcgtgg tcgccaaggc gctgcaggac aagatcctgg cggtgattgc gc -#tgatgggc 4560 - - ctgtggccgc tgatgctggc cattgcggta ggcgtgaaga tgagctcgcc cg -#gcccggtg 4620 - - ttcttccgtc agcgccgcca cggcctgggt ggccgcgagt tctacatgtt ca -#agttccgc 4680 - - tcgatgcggg tgcatgacga tcatggcacc acgattcagc aggcgaccaa ga -#acgacacg 4740 - - cggattacgc gcttcggcag tttcctgcgc cgcagcagcc tggacgagct gc -#cgcagatc 4800 - - ttcaatgtct tgggtggcag catgtcgatc gtgggcccgc gcccgcacgc cg -#cgcagcac 4860 - - aacacgcact atgaaaagct gatcaaccat tacatgcagc gtcactacgt ca -#agccgggg 4920 - - attaccggtt gggcgcaggt caacggtttc cgcggtgaga ccccggagct gc -#ggacgatg 4980 - - aagaagcgca tccagtacga ccttgactac atccgtcgtt ggtcgctgtg gc -#tggatatc 5040 - - cgcatcatcg tgctgacggc cgtgcgcgtg ctcggacaga agaccgcgta ct -#gatgacgg 5100 - - tggggagtgt gcgacctggc gcaccttgcg ccgcgggcgg ctgcatcgca gc -#cgcctttc 5160 - - tctcgcgggc gctgacatgc tgattcaaat gagcgagcag gcgcgggtgc gt -#tggcacaa 5220 - - cgcgctgatc gagctgaccc tgctgaccgg cgtgggctac aacctgctgc tg -#gcgttgat 5280 - - caacgccaac gtgttcaccg tacgtccggt gatcacatat gcagtggaat tt -#ctggtcta 5340 - - cgcagcctgt ttcctgctcg ggctgggctc gatgagccga cagcgcatcg cg -#atgatctt 5400 - - cggcgggcta ggcttgatcg tgacgctgat gttcgtgcgt ttcctggtca ac -#tggcagat 5460 - - cgaccccaag ttcttccgcg atgccctggt ggtctttgca tttgtcgtgc tg -#gggtctgc 5520 - - ttacaccggc tcgttgccca agctgttcat acgcatgacg atcatcgtgt ca -#ttggtcgc 5580 - - tgcgttcgag ctggcgatgc cctcggctta tggcgatctg gtcaacccga ag -#agcttctt 5640 - - cgtcaatgcg cgcggcatga gtgcagaagg gttctggaac gaggacagca at -#ctgttcgt 5700 - - cagtgccaca cgacccggtg agcgcaactt cctcccaggc tcgaacctgc ca -#cgcgcctc 5760 - - ttcctggttc atcgagccgg tgacgatggg caattacatc tgcttcttca cc -#gcgatcgt 5820 - - attgacgttc tggcgctgga tgcggccgtc gatgctgatt ctgtctattg ga -#ttgatcgg 5880 - - cttcatgatt gtggcatccg acggccgact ggctgccggc acctgtgtgc tg -#atggtgct 5940 - - gctgtcgccg ttattgaaac ggatggatca gcggttggcg ttcctgttgt tc -#ctgtttgt 6000 - - gatcgcctct gcctggctgc tggtgtggat gaccgggatt acggcctacc ag -#gacaccac 6060 - - gatggggcgc atcttcttca ctgtgaattc gatgaacaat ctatcgttcg ag -#tcgtggat 6120 - - gggcctggat tttgcgcagg cctaccggta tttcgacagc ggtatttctt ac -#tttattgc 6180 - - ttcgcagtcg attgtcggcg tgctggcgtt cctgctgtct tattcgttcc tg -#ctgctgat 6240 - - gccgagcaag gaagggcagt tgttcaaaaa ccaggcgatg tttgcctttg ca -#ctgagcct 6300 - - gttggtgtct aacggctatt tctcgatcaa gacatcggcg ctgtggtggt tt -#gtctgcgg 6360 - - ctgcatgtgg cacctgatgc cagcagcgtc agccgtgccg gtgcgcgacg aa -#agcaagga 6420 - - agatccaacg gacaacggcg tgcatgtgcc gttgcccgca ggagcgccgc gg -#tgaatacg 6480 - - gtgacagggg catcggggac gtcggcgcct gtgcaggctg ccggcgcgcg tg -#ccttcgcg 6540 - - agcggccgta gccgcgatcc acgtatcgat gcgaccaagg cgatcgcgat at -#tgctggtg 6600 - - gtgttctgcc acgcaaaagg cgtgccgcac ggaatgaccc tgtttgccta ca -#gctttcac 6660 - - gttccgcttt tcttcctcgt gtcgggttgg ctggctgccg gttatgcctc gc -#gcacaacc 6720 - - agcctgctgc agacaatcac caagcaggca cgtggtctgt tgctgcccta tg -#tcgtgttc 6780 - - tatctgcttg gatatgtgta ttggctgttg acgcgcaaca tcggcgagaa ag -#ctgcacgt 6840 - - tgggggagcc acccgtggtg ggagccgatc gtgtcgatgt ttaccggcgt cg -#gcccggat 6900 - - ctgtatgtgc agccgccgct gtggttcctg ccggtgatgc tggtcaccgt ga -#ttggctac 6960 - - gttctgttgc ggcgctggat gccgccactg gtcattgcgg ctgtcgcagt tg -#ttctcgcc 7020 - - tggttctgga tgaactggtt tccgctccag cacatgcgat tgttctgggg cc -#tggatgtg 7080 - - ctaccggtgt cgctgtgctt ctacgcactg ggcgcgctgc tgatccacgt gt -#cgccgtat 7140 - - cttccaacct ccttgcctgg tagcgcgttg gtcaccgtag tgctggcagc at -#tggttgcc 7200 - - tggctggccg gggtcaacgg ccgcatcgat gtcaacatgc tggaattcgg aa -#ggcagcat 7260 - - gccgtattcc tgttgagtgc agtggcgggt tcgttgatgg tgatctgcgc gg -#cgcgcatg 7320 - - gtgcaggaat ggacatggct gcagtggatc gggcgcaaca ccttgctgat cc -#tgtgcacg 7380 - - cacatgctgg tcttctttgt actgtctggt gttgcggcct tggcgggtgg gt -#ttggtggg 7440 - - gcgcgcccag gccttggttg ggccatcttc gtgacgctct ttgcgctggt cg -#ccagcgtt 7500 - - ccgctgcgct ggtttctgat gcgttttgcc ccctggacct tgggtgcacg tc -#cggtgtcg 7560 - - gcatgacgac ggctgcgatc actgccggtc gcgtcgacac aatcgcctca ac -#tgtcgcgg 7620 - - agcgcgactg gcagatcgac gtggccaagg ctcttgcgat cattctggtc gc -#gctggggc 7680 - - acgccagtgg catgccgcct gcctacaagc tgtttgccta cagcttccat gt -#gcctctgt 7740 - - ttttcgttct ttccggctgg gtcggtgaac gcttcgggcg tcgtgcattt gg -#ccggaaga 7800 - - cggtgggaaa gcttgcgcgc acgctgctga ttccctacgt cagctttttt ct -#ggtggctt 7860 - - acggctactg gatactgagc gcagtgctca acggcacatc ccagtcctgg gc -#tggccacc 7920 - - cctggtggca tccgtttgtt ggattgctgt gggccaatgg atccagcttg ta -#tgtgctcc 7980 - - cggccttgtg gtttctcccc gcactgtttg tcgccaccgt tgtctacctg gc -#actgcgcg 8040 - - aagacctgag cgccgcagtg ctcgcggtct gcagtttgct ggttgtgtgg gc -#gtggacgc 8100 - - gttggttccc agggctgcgg ctgcgccttc cgtttgcact ggatgtgctg cc -#ggtcgcgc 8160 - - tgttcttcat tgcagtcggc gcatggctgt cacgcttcgc agagagagtg cg -#cgcgcttc 8220 - - ctgcggtcgt ttgggtcgtc gcgttcccgg tcctggcatt cgcctggggg gg -#cgttgcag 8280 - - ccatgaacgg gcaggtggat gtcaataatc ttcagttcgg aaaatcgtcg ct -#cctgttcc 8340 - - tgatcgcaag cctgctgggt acagcaatga cgttgtgcat tgcctacttc at -#gcaagggt 8400 - - ggcgctggct gcgttggatc ggcgccaata cgctgctgat ccttggcacg ca -#cacgttgg 8460 - - tgtttctggt cgtgaccagt gtcgtggtgc gaaccggggt gatcgatcgc aa -#actcatcg 8520 - - gtacacctgt ctgggcgctg gctctctgcg cctttgccat cgctgcctgc at -#tcccatgc 8580 - - gtgccgtgct ggtgcgccgc gccctggatg ttgggattga aacgcaagtg ag -#acattttc 8640 - - agaatcatca gtcgatgtgg cgtgttcgtg tgagtcaccg gcaaaggaga tc -#ggcgcaat 8700 - - gaaagtcgtg catgtggtcc gccagttcca tccgtcgatc ggggggatgg ag -#gaagtcgt 8760 - - gctgaacgtg gcacgtcagc atcaggccaa cagtgccgac acggttgaga tc -#gtgacgtt 8820 - - ggatcgtgtg ttcaccgatc cctctgcgca actggcgcag cacgagctcc at -#caggggtt 8880 - - gtcgatcact cgcatcggct atcgtggttc atcgcggtac ccgatcgcgc cg -#tcggtgct 8940 - - gggggcgatc cgttcggcgg acgtggtgca tctgcatggc attgattttt tc -#tacgacta 9000 - - cctggcgttg accaagccgc tgcacggcaa gccgatggtg gtctcgacgc at -#ggcgggtt 9060 - - tttccacact gcctatgcgt cgcgcatgaa gcagatctgg ttccagacgc tg -#acgcgtac 9120 - - ttctgcgctg gcctatgcgc gtgtgatcgc cactagcgag aatgacggcg at -#ctgttcgc 9180 - - caaggtggtc gcgccgtcgc gcttgcgggt gatcgagaac ggtgtcgacg tg -#gagaagta 9240 - - tgcagggcag ggcgctcgag cgccgggacg gaccatgctg tatttcgggc gt -#tggtcggt 9300 - - caacaagggc ctgatcgaaa cgcttgaatt gctgcaggct gcgctcacgc gt -#gatccgca 9360 - - gtggcggttg atcatcgccg ggcgcgagta cgatttgaat gaggcggatc tg -#cgcaaggc 9420 - - catcgccgaa cgcggtttgc aggacaaggt gcagctgagc atgtcgccat cg -#cagcagca 9480 - - gttgtgcgcg ttgatgcagc aggcgcagtt cttcgtgtgc ctgtcgcggc at -#gaggggtt 9540 - - tgggattgcg gcggtggaag cgatgagcgc ggggttgatc ccgattctca gc -#gacattcc 9600 - - tccgttcgtg cggcttgcca ccgagtccgg acagggtgtg atcgtcaatc gc -#gacaggat 9660 - - tcaggccgcg gccgacagcg tgcaagcatt ggcgctgcag gccaatgcgg at -#ttcgatgc 9720 - - gcgccgcacg gcgaccatgg cgtatgtggc gcgctacgac tggcggcacg tg -#gtggggcg 9780 - - ttatatcgac gagtaccacg ctgcgctggg aacaccacgt acgcaggagg cc -#gtgcgatg 9840 - - agcgcgtctg cttcgctgcc agtgacgcgt gctgctgcgg cgccccggat ca -#cggtgctg 9900 - - ttctccaccg aaaagccgaa cgccaacacc aacccgtatc tcacccagct ct -#acgatgcg 9960 - - ctgccggacg cggtgcagcc gcgcttcttt tcgatgcgcg aggcgttgtt gt -#cgcgctac 10020 - - gacgtgctgc atctgcactg gccggaatat ctgctgcgcc atcccagcaa ga -#tgggcacg 10080 - - ctggccaagc aggcctgcgc tgccttgctg ctgatgaagt tgcagctgac cg -#gcacgccg 10140 - - gtggtacgca ccttgcacaa cctggcgccg catgaagacc gcggctggcg gg -#agcgcgcg 10200 - - ctgctgcgct ggatcgatca gctcacgcgg cgctggatcc gcatcaacgc ca -#ctacaccg 10260 - - gtgcggccgc cgttcaccga caccatcctg cacggccatt accgcgactg gt -#tcgcgacg 10320 - - atggagcaga gcaccacgtt gcctggtcgg ctgctgcatt ttggattgat cc -#ggccgtac 10380 - - aagggcgttg aggtgttgct cgacgtcatg cgcggatgtg caggacccgc gc -#ctgagcct 10440 - - gcgcatcgtc ggcaacccgg cgacgccagg atgcgcacgc tggtcgaaac cg -#cctgcgcg 10500 - - caggatgcac gtatcagtgc actgctggcc tatgtcgagg agccggtgct cg -#cgcgcgaa 10560 - - gtcagtgcct gcgaactggt ggtactgcca tacaagcaga tgcacaactc cg -#gcaccttg 10620 - - ctgctggcgt tgtcgttggc gcggcccgtg cttgcgccgt ggagcgaatc ga -#acgccgcg 10680 - - atcgccgacg aagtcgggcc gggttgggtg ttcctgtacg aaggcgagtt cg -#atgcggcg 10740 - - ttgttgagcg gcatgctcga tcaggtgcgc gccgcgccgc gtggcccggc gc -#ccgatctt 10800 - - tcacaacgtg attggccacg gatcgggcaa ttgcactatc gcacctactt gg -#aagcgctc 10860 - - ggcaaggatg gagacgccgc gctgtgaccg cagagacatc gaccatgact tc -#cccaacac 10920 - - cgccgccgcg cagcctcggg tcgcgtgccg ctggcgccgc cgtgaccatg at -#cgggcagt 10980 - - cggccaagat gatcgtgcag ttcggcggca tcgtgctgct ggcacgcttg tt -#gacgccgt 11040 - - acgactacgg cttgatggcc atggtgaccg ccatcgtggg ggccgccgaa at -#cctgcgcg 11100 - - acttcggtct ctccgcagcc gccgtccagg cgaaacatgt cagccgcgag ca -#acgcgaca 11160 - - acctgttctg gatcaatagc ggcatcggtc tgatgctgtc ggtggtggtg tt -#cgccagcg 11220 - - cgcactggat tgcggacttt tatcacgagc ccgcattggt gacgatttcg ca -#ggcattgg 11280 - - cggtgacctt cctgctcaac gggatgacca cccaataccg cgcacacctc ag -#tcgggggc 11340 - - tgcgcttcgg tcaggtagcg ctgagcgatg tgggttcgca ggtgttgggg tt -#gggtgctg 11400 - - cagttgcggc cgccttggcc ggctggggct actgggcgtt gatcgtgcag ca -#ggtggtgc 11460 - - aggccatcgt gaacctgatt atcgctggcg catgtgcacg ctggttgccg cg -#cgggtacg 11520 - - cgcggcaggc gccgatgcgc gatttcatga gctttggctg gaacctgatg gc -#ggcgcagc 11580 - - tgctcggcta tgcgagccgc aacgttggcc aggtgatcat cggctggagg ac -#cgggcccg 11640 - - acgcgctggg tctgtacaac cgtgccttcc agttgttgat gatgccgttg aa -#tcagatca 11700 - - atgcgcctgc gactagtgtg gcgctgccgg tgttgtcgca attgcaggat ga -#gcgcgagc 11760 - - gctacagcgc ttttctgttg cgcggccaga cggtcatggt gcatttgatc tt -#tgcgctgt 11820 - - tcgcgtttgc ctgtgcactg gccatgccgc tcatcgtcct ggtgctgggt ga -#gcagtggc 11880 - - gggaagcggt gccgctgttt caggtgttga cgctgggcgg tatcttccag ac -#ggcgtcgt 11940 - - acgcaaccta ctgggtgttc ctgtcgaagg ggttgatgcg cgagcagttg gt -#gtattcgt 12000 - - tggtcggtcg catcctgctc atcgcctgca tttttgttgg ctcccgctgg gg -#ggccatgg 12060 - - gcgtggcgat cggctactca ttcggcctgc tgttgatctg gccgctgtcg ct -#ggtctgga 12120 - - tcggcaagat cacggacgca ccggtcggtg cgttgttcgt caatgccatg cg -#tgcgctgg 12180 - - tggcctacgg tatcgccggc ggctgcgctt attacgcatc ggtcactgtc gg -#tggtccat 12240 - - tgtggcagca gctgctggtc ggcgccggcg cgatggcgct ggtctgtctg ct -#cgcattgg 12300 - - catggccggg attccggcgt gacgtggtcg ctatcgtcaa tatccgcaag ct -#gctcacgc 12360 - - aggcgaaggc gcgccgatga cactgcactg cggtactgga atgttggact tc -#gaaacttc 12420 - - ccactcttgc aaaggacacg gcctatgagc gtctctcccg cagctccagc tt -#ccggcatt 12480 - - cgccgtccct gctatctggt cttgtctgct cacgatttcc gcacgccacg tc -#gggctaac 12540 - - atccatttca tcaccgatca gttggctttg cgtggcacga cgcgtttttt tt -#cgttgcga 12600 - - tacagcagac tctcccgcat gaagggagat atgcgcctgc cgctggatga ca -#ccgcaaat 12660 - - accgttgtct cgcacaacgg tgtggactgt tacctgtggc gcacgacggt gc -#atccattc 12720 - - aatacacgcc ggagctggct acgtcctgtg gaagacgcca tgttccgctg gt -#atgccgcg 12780 - - catccgccaa agcagttgct ggactggatg cgcgagtccg atgtcatcgt gt -#ttgaaagc 12840 - - gggatcgcag tcgcattcat cgagcttgcc aagcgggtca atccggctgc ca -#aactggtc 12900 - - tatcgcgcgt cggacgggct gagcaccatc aacgtggcgt cttacatcga gc -#gcgagttc 12960 - - gaccgcgtgg ctccgacgct ggacgtcatt gccttggtgt cgcccgcgat gg -#ccgcagaa 13020 - - gtagcaagcc gcgacaacgt cttccatgta ggtcacggcg tggaccacaa cc -#tcgatcag 13080 - - ctcggcgacc cgtcgccgta tgccgaaggc atccatgcag ttgcggtcgg gt -#cgatgctg 13140 - - tttgatcctg aatttttcgt cgttgccagc aaggcctttc cgcaagtgac ct -#tccacgtg 13200 - - atcggctccg ggatgggccg ccatccgggc tacggcgaca atgtcattgt ct -#atggcgaa 13260 - - atgaagcacg cgcagacgat tggctatatc aagcacgcac gtttcggcat tg -#cgccttac 13320 - - gcgtccgagc aggtgccggt gtatctggca gacagctcaa tgaaattgct gc -#aatacgac 13380 - - tttttcggct tgccggcggt gtgcccgaat gctgtggtgg ggccgtacaa at -#cgcgcttc 13440 - - gggtacacgc caggcaatgc cgattcggtg attgccgcca ttacccaggc ac -#tggaagca 13500 - - ccgcgtgtac gttaccgcca gtgtctcaac tggtccgaca ccaccgaccg cg -#tgctcgac 13560 - - ccacgggcgt acccggaaac ccgtctttat ccgcaccccc ccaccgccgc gc -#cgcagctc 13620 - - tcttcggagg cagcgctctc acattgagga ggcgcttttt tgatcacgtt tg -#aaggagga 13680 - - tccctgtcat ggccaacgct ttactgcaga aatgggtgga acgggcggaa cg -#tcgcgcat 13740 - - tgttctggtg gcagcccaaa aacggtggcg tgaacatggg ggatcacctg tc -#gaaggtga 13800 - - tcgtgtcgtg cgtgttggcg ttgcaggaca agacacttct ggaaaaacgc ga -#tttgcgcc 13860 - - agaagctgat cgcaaccggg tcggtgctgc atttcgccaa agatggcgac ac -#cgtgtggg 13920 - - gaagcggtat caacggcaag attccggccg agcgcaatac gttcagcacg ct -#ggacgtac 13980 - - gcgcggtacg cggtcccaag acccgcgcat ttttgctgga acgtggcatc gc -#agtgcctg 14040 - - aggtctacgg agacccggga ttgctgaccc cgatgttttt ccccgccgac gc -#cctcggcc 14100 - - cggtcaccaa gcgcccgttc gcgatcgtgc cgcacttcaa cgagccggtt ga -#gaagtaca 14160 - - gcgcctacgc cgagcatctg gtgtttccca acgtcaagcc ggccaccttc at -#gagtgcgc 14220 - - tgctgggtgc ggaatttgtc atcagcagtt cgctgcatgg cctgatcctg gc -#cgaagcct 14280 - - atggcatccc ggcggtgtat ctggactggg gcaacggcga agaccgtttc aa -#gtacgacg 14340 - - actactacca cggcaccggg cgcatgcaat ggcatgccgg ccacagcgtg ga -#agaatgca 14400 - - tggaactggg cggcaacggc agtttcgatc ttgaacgctt gcaggcagga tt -#gctggctg 14460 - - cgttccctta cgatttgtgg tgaaacgaca atgcatggcc agccagcagg tg -#tggagacg 14520 - - gcaacggtga gtgcagcgac acctgcgcaa ggggtggtga ttccgctggg cg -#gcttcccg 14580 - - gtgttgtcga ccacgcagga agccttcgcg ctggatctgt tccatgcgct gg -#ccgcgcat 14640 - - cagccgcgcc gggtgttttt cgcgaacacc aacttcatcg tgcagtgcca gg -#cgctgcgc 14700 - - gcgcgcatgc aggcgccggc agtgcgcatc gtcaacgatg ggatcggcat gg -#atctggcg 14760 - - gcgcgcctga tccatggccg ccggttcgcc ggcaacctca acggcaccga cc -#tgattccg 14820 - - tacctttgcc gcgaggccgc gcagccgctc aagttcttcc tgctcggcgg cc -#gcccgggc 14880 - - gtgggcaaga ccgccgcggc gaccttgacc ggaacgctgg gccagcaggt cg -#tgggcatg 14940 - - tgcgatgggt atggcgaatt tgcggcggcg ggcgagggcc tggccgagcg ca -#tcaatcgc 15000 - - tccggcgccg atgtgctgtt ggtggccttc ggcaacccgc tgcaggagcg gt -#ggatcctg 15060 - - gaccacagcg aggccttgca ggtgccgctg gtgttcggcg tgggcgcctt gc -#tggatttt 15120 - - ctctccggca ctgccaagcg cgcgcccaac tgggtgcgcc gtttgcatat gg -#aatggatg 15180 - - taccggctgc tcaacgagcc gcgccggttg ctcaagcgct acagctggga tc -#tgctggtg 15240 - - ttcttccgca cctgcctgcg tgcgggcaaa cagctggcgt gatgcacggc gg -#cggtgtgt 15300 - - ggcctagcat gcgtgcatgc atccaaccgc cgccgcgctg attcgaacat tg -#ggccttgc 15360 - - cccccatccg gagggcggcc actaccggcg cgtgtacgcg tcgacgcgcc ag -#gtgctgga 15420 - - tgacagcggt gcgccgccgc gtccggcgct gaccgccatc cgcttcctgt tg -#tgcgcagg 15480 - - cgaagccagt cgctggcatc gggtggatgc cgaggagtgc tggcactggc ag -#caaggtgc 15540 - - gccgctggag ttgctgatct tcgacgaagc gagcgggcag ttgcggcgcg aa -#gtgctgga 15600 - - cgccgcagag cgcggcgacg ccatgcacgt ggtgccggcc ggctgctggc ag -#gcggcgcg 15660 - - ctcgctgggg gacttcaccc tggtgggctg cacggtttcg ccagggtttg tc -#tgggaagg 15720 - - tttcgcgctg ctcgaagacg gctcgccgct ggcggcacag ctggccgcgt tg -#gttgccga 15780 - - aggcgccgcg ccggagccgc caacgcttcc ctaacgcgtg cgggcccgcg tt -#cgcgtagt 15840 - - gtccgcgttc caaccgggag gcggtacgtg atgcagcgca ggggggcggt gt -#ggcgggca 15900 - - ggaatcgcgt tggtgtcgtt gttggcaccg atgctggcgt gtgccgtcga gg -#tggccgta 15960 - - caggcgccgg cagcgccgcc aacggtggtc gatctggaag ccatggtggt gc -#gcgggcag 16020 - - caacccggcc ccggcctgtg gaaggtcagc aagggcgacc acgtgctgtg ga - #tcc 16075 - - - - <210> SEQ ID NO 2 <211> LENGTH: 28804 <212> TYPE: DNA <213> ORGANISM: Sphingomonas sp. S88 - - <400> SEQUENCE: 2 - - ggatccactg gccgggaatt gccgagaatc ctccgatgaa gcgctcgtcg gg -#taccagcg 60 - - tgccccgggg cgcatcgctt tgcgccggcg catcgccgcc gctgccgggc cg -#gccattcc 120 - - agcggggtcc gggctgcaaa atccccgggc ctgcctttac gccatgcccg gc -#agccgagc 180 - - tgccgggcgc cgagcatgcg agcggcgtaa ccgatagggc gaggcccccg cc -#cagaaggg 240 - - tgcgacgtgt ggtatcgatc atgcggcgcg ctccaaaccg tgcgcgccgt ga -#ctacaacc 300 - - aaaaatgctg cgctgcgagc gggatcaggc gccccgtgcc tgcttcgagc gg -#tacagcag 360 - - cgcgaacgtc agccccacca gcatgaagaa gacttggtcg ttgtcggtct gc -#gacagcac 420 - - gagcctggta ttgagcagca cgaccatcgt cgtcgcgacc gccagatgca gc -#ggatagcc 480 - - ttgggagggg tccgtcaacc cggcgcggat caacagcccg gcacccagca cc -#atcgtacc 540 - - gtagaatgcg atgaagccga gcaccccgta atcgacggcc gtcgaaagga ag -#ccggagtc 600 - - gatcgacagg aacccgctct gggaacgcca tccgacgacc tccgcggact gg -#aacggccc 660 - - gtagccgaat accgggcgca tcgcgagctt gggcaagccc atgcggatct gc -#tcgtggcg 720 - - cccgtcgttg ctcgcctggg tcgcgccgcc gccaagaacg cgattgtgta cc -#gcaggcac 780 - - taccatgatc atcaccgcga gaaccacggc gaaggccgga tacatcatcg tc -#gtggaaat 840 - - cccgacgagc ccgccacgct ccttgatcca gcgccgcagg ccccagagca ac -#agataggt 900 - - ggcatgcgcc acgaccatgc cgaccatgct caggcgcgcg ccgctccaat ag -#gcggacaa 960 - - taccatggcg agatcgaaca ggatcgtgag tgccagcgcc gacaccgacc gg -#ctgttcac 1020 - - catcaggtgg atcgcgaagg gaatcgtcat cgccacgagt tcgccccaca cc -#agcgggtt 1080 - - cccgaacacg ttcatcacgc gatacgtgcc gcgcacctgc gaggtgagat gc -#aggatgac 1140 - - gctcggatcg ttgatctgca gccagctggg aatgtggccg acccacagaa cg -#tgctcggc 1200 - - ccggaactcg aagaagccga tcaccatcag cacggacacg cagcccagca tg -#ttccgcac 1260 - - ccaccattcg ggtgtgcgcg tgttcgatcc caggcaccac agcgtcgcga ag -#aagaacgg 1320 - - cgtgaccgtc agcgagatat tcaccaggcg cccgatcgaa acggatggct gg -#ctggaaat 1380 - - gagcgacgcg atgatctgga tgatcaggaa gcccagcatg aagcgggcaa gc -#cagggcga 1440 - - cgccgacagc gtcaccgcca tgtcgcgccg aaacttcggc gaaatcgaat ag -#cacaccag 1500 - - cagaagaagc gtcgtcagca cgccgaacag gcggcggaag gagatccagg gc -#aggcccgc 1560 - - caccgacagc gacagatagt tcggccacac gatcgcgagg atcatgaaca gg -#acgtagca 1620 - - gcgcagcagc aacttggtgg gcgccttgtc ggcctccggg agcgcccaga tg -#acgaacag 1680 - - cgcgaggatc gccagcggcg cggcggcccc gaggagcatg ctgggcggca gg -#atcgccga 1740 - - aagcagcccg tagaccatcg acacgaacac gatcacggcg agcccgatga ag -#cgccgccc 1800 - - gagcgtgacg agaccagagc gttgcgggtg atagagcggg agcaccgctc tg -#gcggggaa 1860 - - gaacacgatg tcgcgcgccc ggcgcagggg ctgcaccacc cgcgccaagc cg -#ccgctccc 1920 - - ccgaactcgc gccgatgtcg ccatgaccaa ccccttagat aatcggtatg cc -#gatcagcc 1980 - - gcaccgcgac catcgacacg aagcgcagga agaccgacgg caccgcgatc gc -#aatcgccg 2040 - - cgcctagtgc accatagggc ggaatcagga ccagcgcgag tattgcggca ag -#gataaccg 2100 - - acgacatggt cagcaccacg gccagacgct cgcgattggc catgacgagg ac -#gccgccgc 2160 - - tcgacgcgaa gaccatcccg aacacctgcc caagcaccag cacctgcatc gc -#ggcggcgc 2220 - - ccgcggtgaa ctgtttgccg aacaggccca tgatccaatg cggagcgacc ag -#caccgcca 2280 - - gggcgatggg cgaggcggcg accagcagcg cgagaatggt gatccggatg at -#gcgggcga 2340 - - tccgcttgac gtcgccctgt tcgtaggagg cggcaaagac cggatgcagg at -#cgtctcgg 2400 - - aggtggccga cagcaacttg agcgaggatg cgatctgata gcccacccgg aa -#cagaccgg 2460 - - cttcggcggg gccgtgcgtc gcggcaagga tcacggtggc aaaccagtcg ac -#gaagaagt 2520 - - tgttgacgtt ggtgatcagc accatgaagc cggggcgaag catcggccgg tc -#caacggct 2580 - - cggccggcgc ccaatcacgc gtcatgcggc ggacgatgat cgtcgcggca aa -#catcgtca 2640 - - ccagccagcc gaccaggtac agcaccgacg gcagcagcgg attatgggca ac -#gccgatca 2700 - - gcagcgcgcc ggccagcatc gccccaccca ggaaggtgcc gagcggccca tc -#gaccatct 2760 - - gcgacttgcc gatatccccc atgccgcgca gcgtcgtcga agcgagacgg ca -#ataggcgc 2820 - - tgaccggaat gagaaacccc atgatcagaa ggtccggcgc catggcgggg ct -#gcccagca 2880 - - ggttggtggc aatctgttgg tgaaacagca ggatcatcac catcaggacc ag -#gccaccac 2940 - - ccaccgcgac ccgcgtggca tgccgcactg cggtacgcgc cacacccgtc cg -#attttgcg 3000 - - acacgcagac ggccacggtg cgcaccagga tggtatcgag gccgatcagc ga -#cagaatga 3060 - - ccagcatctg cgcagtcgtg agcgccgtac cgaaggcacc gacgccggcg gg -#gccaaagg 3120 - - cgcgggcgac cagccaggtg aaagcgaaac tggtgacggc gccgaagccc tt -#gacgccga 3180 - - agccgaccac catctgcccc cgcagccccc gcaggtgcaa cttgctacgt gt -#cacgttga 3240 - - atgcttgccc cacaggagat cccgtctgtg ccttatggca gggccctccc gg -#gggcaagc 3300 - - ctgaggacgt catcagacgt gatagaagtc ctgcaccaac ttcttggtgg cg -#aacaggct 3360 - - attcgccacg gacaggctgc ccgtcgccga gacggccgca gtgccggccg ca -#ttcatggc 3420 - - gatcgcctgg gcgagcgaca cttgcgcgac ggacgccgtc gatgccgatc cc -#cccagcgt 3480 - - cagcgtgccg gtggtcgccg ccggcagcgc cgtcgacgtg accggggtgc cg -#agaatggt 3540 - - tacggcgctg gcggccaagc tgctggtgag gctgggcttc acggtggtgg tc -#ggctggct 3600 - - ggcggcggtc gccgcggcat tcagcgcaag gatctgggac gcactgaggg ca -#gcgtcgcg 3660 - - catctcgatc tcgcccacgc tgccgctgaa gacagcgttg aacgggctgc cg -#atgtacag 3720 - - tccggcatat tcgaccgccc gcgtgctgcc gacgatcgtt cccgatccct tc -#accacgcc 3780 - - atcgacatag atgatcgcct tgcccttcgc gctgtcatag gtcagcgcga tc -#ttgtgggt 3840 - - ggccgtgtcg gtcatcttgg cgccgctcgt cgcgacggta tagctctgcc cg -#gcggcatt 3900 - - cttgacggtg aagaccagtt cgccgtccgc ccggagcgag attccccagc tc -#tggttgac 3960 - - gcccatgatc tggccgaccg cgcccgtcgc ggtggcacgc ttcatgtcga ag -#ttgagcgt 4020 - - gaaggcgggc agcgcgaaga gttgacgtga attgtcccgc gtaagctcga ag -#ccggtgcc 4080 - - ggtcttcacc tggaacatgc cgttgctgat ggcggtgaga tccagcgcct tc -#gtggtctc 4140 - - gtccgtgctc cagcgcgtct ggtccacgat tccggtcgca gtgaactgca ga -#tccagcag 4200 - - caggttggcg ccggtcgagg tctgtgctgc cgcctgctcc ttggcgacct gc -#gcggcaaa 4260 - - cgcgctgcct gcaggcggct gatacccgac accactgacg atcaggttcg cc -#agttgcgc 4320 - - cttcgatccg gccatgagat cgccgatctt gcgaagagtg accgcgtccg tt -#gcaagcac 4380 - - ggcgttgttc gattgagtaa tgccgctcga cgttgcggtg atgacaacct gg -#tccacgac 4440 - - attgttggtg accttgccgc cggtcacgcc gtccaggcgg atccaatcgg cg -#atcgcatc 4500 - - catcttcgag atgatggtat tggagtccac ggtgacgttc ttgcccagaa cg -#acattgat 4560 - - gccgtgcgtg aaaccattct ggtacacgag attgtttttg atcgtgatgt tt -#tcgtaggg 4620 - - aatgctggat tcattgccca tgaatacgcc ctggaaggcc aggccgtccc cc -#tgcatcat 4680 - - cacgttattg gtgatcgtga tgttcgtgtt gcccttggtc ttgccgttcg tc -#atgaactg 4740 - - gatggcgtcg ggatgctcac cattcaccgg atagaggttg gtgaacatgt tg -#ttgtcgat 4800 - - gacgacgttc gacgcttcgg cgaaattggt gtgatcgcgg cgattgtcgt gg -#aagttgtt 4860 - - gccctgcagg gtgacaccgt cgacggtgag gacgttcatc cccagggcga aa -#tgatcgac 4920 - - cgaggaattc ttgatcgtca cccccttgct ttctcgcagc agaagccccc ag -#cccatcga 4980 - - cttcgtcaca tcgcccgtac ccccgctcag ggtcacgccg tcgatcacga ca -#ttgctgga 5040 - - gccgatgatc cggttcgcgt aattatagtc ctgtgccggc tggaagtttt gt -#gcggccgt 5100 - - gacgttcttc accaccaggt tgctgctgtt gatgatctgc agggtcgtca ca -#ttcaccgg 5160 - - cttgctcgca tcgagcgagg tgatcgtgac gggcgtggtg aaggtcgtgg tg -#tgcacggt 5220 - - gatggacgta taggtccccg ccgcaagctt gatcgtctcg ccccctttcg ca -#gccttgat 5280 - - ggcggcgtcc agttcgctct gattcctcac gatgatgtcc ggcatgtact ct -#accctcgt 5340 - - tacgcgtcga ccccaatcga cctgcgatcc ctcggaccgt cttgtacctg cc -#aagccctg 5400 - - aaacggtggc taagaggcag ggttaatgcc ctgtttttca agccgataac tg -#gcagccct 5460 - - caaggcactg ccagcgtgcg ggcaacactc tcgacgccgc agtgcagcac gg -#gtaagaac 5520 - - gaggcatgga agcctcgccc acacccgacg tcagcatcct ggtggttgcc ta -#ccactcgg 5580 - - ctccgttcat cggacaatgc atccggggca tcgccgcggc ggcacaaggc ac -#agcccacg 5640 - - aaatcctgct gatcgacaat ggcggcggcg acaccgaggc ggtggttcgt gc -#cgagttcc 5700 - - cgcacgtgcg gatcgtgccg agcgagggca atatcggctt cggggcgggg aa -#taaccggt 5760 - - gtgcggccca tgcccgcgcg ccgcggctgc tgctcgtcaa ccccgacgcc at -#tccccgcc 5820 - - ccggcgcgat cgacctgctg gtcgccttcg ccaaggcgca cccggacgcg gc -#agcctggg 5880 - - gcgggcgttc ctattttccg aacggccagc tggaccatgc caacttcctc cc -#gctgccca 5940 - - cggtgcgcga tttcgtcgtg tcgatcttca gcagcagccc gatgcggcgc gg -#cggccttc 6000 - - ctgccgacgc caccgcgccc gggccggtcg aggtgctcaa cggcggcttc at -#gatggtcg 6060 - - atgcccgcgt gtggcgggag atcgacggct tcgacgaagg cttcttcctc ta -#ttcggagg 6120 - - aaatcgatct gttccagcgg atccgcgcgc ggggctattc cgtgctggtc ga -#tccggctg 6180 - - tgggcgtggt gcacgacacc ggtggcgggc attcgctctc gcccactcgc gt -#gctgtttc 6240 - - tcaccaccgg ccgcatgcat tatgcccgca agcatttcgg ccacgtcggt gc -#cgtcgtga 6300 - - cgggctgggc actgtgggcc aatgccgcca aatatgtcgt tatcggcggc ct -#gctcgggc 6360 - - gcctctcacc ccgccgcgcg gcgcgctgga acgcgctgcg cgatgcctgg ag -#catcgtgt 6420 - - tcggccagcc gcggcgctgg tggcacggct ggcgcgacca cgttcgtact tg -#aggatagc 6480 - - gccgcgccag acggcccgaa atggcaaccc gacgcaaggc ggaaggcttg cc -#gacggcaa 6540 - - gccccccgac ttgtcgctca ctgcgcggcg ttgggcgccg gagcaggggc cg -#cagcaggc 6600 - - gcggcggcag cgccgccctg cagttgcggc ggcgggctgt agcccggctg at -#atttcacc 6660 - - gactcgcgcg ccttcttcag acgatcgttc agctgcgcgt ccgccgcctt gc -#tgaaccgc 6720 - - tcggtgcgca gcgtattgag cgcgagttcg cgcgcctgat cgcccgccag cg -#gctggatc 6780 - - gtcgtgccgg tgatgacatt ggcggtgacg ccctgctgcg tcggcaggat ga -#acagctcc 6840 - - tgcgccggca gcgccgcaat cttggcggcg atctccggcg gcaacgcggc gg -#tgtccagc 6900 - - tgggtcggcg cgcggcggaa ctgcacgccg tcggcggtca gcttggcggc aa -#gctggtcc 6960 - - aacgtcttga gcggcgcgaa ttccttgaac ttcgccgccg agccgggcgg cg -#ggaagacg 7020 - - atctgttcga tgctgtagat cttgcgctgc gcgaagcgat cgggatgcgc cg -#cttcatat 7080 - - tgcgcgatct cggcatcggt cggctgggcg atgccgccgg caatcttgtc gc -#gcagcagc 7140 - - gtggtgagga tcaactcgtc ggcgcggcgc tgctggatca ggaagacggg gg -#tcttgtcc 7200 - - agcttctgct cgcgggcgta cttcgcgaga atcttgcgct cgatgatgcg ct -#gcagcgcc 7260 - - atctgctcgg caagcttgcg gtcggtcccc tgcggcacct gcgtggcctg ca -#cttcggca 7320 - - ttcagttcga agatggtgat ctcgtcgccg tccacgctgg cgacgacctg cc -#ccttatcg 7380 - - agcttgcctt ccttgctgcc acatccggag acggccagcg cggccgcagc ca -#ccgccgtt 7440 - - accaggtaca atttcttcat gaagacctcc cagccggcac ggaattgcgc ac -#ggcacaaa 7500 - - cttctacttg aacctattcg ggcgggcggg catccgcaat agcgttggca gt -#gcagcatg 7560 - - cctcccggcg ggaggcaggc gggatcaatg ggggacggca tggcagaagc ga -#cggtgacc 7620 - - gaagcgaagg cgggcaaacc gctgaaaatg tgtctcgcag cttccggcgg cg -#gccatctg 7680 - - cggcagatcc tcgatctgga atcggtctgg aaggaacatg actatttctt cg -#tgaccgaa 7740 - - gacaccgcgc tgggccgcag ccttgccgaa aaacactcgg tcgcgcttgt cg -#atcactat 7800 - - gccctcggcc aggccaagct cggccacccg ctgcgcatgc tgggaggcgc ct -#ggcggaac 7860 - - ctgcggcaga gcctgtcgat catccgcaag cacaagcccg atgtggtgat ct -#ccaccggt 7920 - - gcgggcgcgg tctatttcac ggcgctgctc gccaagctct cgggcgcaaa gt -#tcgtccac 7980 - - atcgaaagct tcgcccggtt cgatcatcct tccgccttcg gcaagatggt ca -#agggcatc 8040 - - gcgaccgtga ccatcgtcca gtccgccgcg ctcaagcaga cctggccgga tg -#cggagctg 8100 - - ttcgatccct tccgcctgct cgacaccccc cgccctccca agcaggcact ca -#ccttcgcc 8160 - - accgtcggtg ccaccctgcc ctttccgcgg ctcgtgcagg ccgtgctcga tc -#tcaagcgg 8220 - - gccggcgggc tgccgggcaa gctggtgctg caatatggcg accaggacct gg -#ccgacccc 8280 - - ggcatccccg acgtggagat ccgccggacc attcccttcg acgacctcca gc -#tgctgctg 8340 - - cgcgacgcgg acatggtgat ctgccacggc ggcaccggat cgctggtcac cg -#cgctgcgc 8400 - - gccggctgcc gcgtcgtcgc cttcccgcgc cgccacgatc tgggcgagca tt -#atgacgat 8460 - - caccaggaag agatcgcgca gaccttcgcc gatcgcggcc tgctccacgc cg -#tgcgcgac 8520 - - gagcgcgaac tgggcgcggc agtggaggcc gccaaggcga ccgagccgca gc -#tcgccacc 8580 - - accgatcaca cggcgctcgc cggccgcctg cgcgagttgc tggcacagtg ga -#gtgccaag 8640 - - cgatgagcgc gccgcggatc agcgtcgtca tcccgcacta caatgatccg ga -#ctcgctgc 8700 - - gacaatgtct cgatgcactg cagcatcaga cgatcgggcg agaggccttc ga -#gatcatcg 8760 - - tcggagacaa caactccccc tgcggcctgg cggcagtgga agccgccgta gc -#cgggcgcg 8820 - - cgcggatcgt cacgatcctg gagaagggcg ccggaccggc gcggaacggc gc -#cgcggcgg 8880 - - aagcgcaggg cgagattctc gccttcaccg acagcgactg cgtcgtcgag cc -#cggctggc 8940 - - tggccggggg cgtcgcccat gtcgccccgg gccgcttcgt cggcggccac at -#gtatgtgc 9000 - - tcaagccgga agggcgactg accggcgcgg aagcactcga gatggcgctg gc -#cttcgaca 9060 - - atgaaggcta tgttcgccgt gcgaagttca ccgtcactgc caatctgttc gt -#catgcggg 9120 - - ccgatttcga gcgcgtcggc ggatttcgta ccggagtctc ggaagatctg ga -#atggtgcc 9180 - - accgcgccat cgccacgggt ctcgcgatcg actacgcccc cgaggcctcg gt -#aggccacc 9240 - - cgccccggcc ggactgggca acgctactgg tcaagacgcg gcgcatccag cg -#cgagctgt 9300 - - tcctgttcaa tatcgagcgc ccgcgcggcc ggctgcgctg gcttgcgcgc tc -#gacgctgc 9360 - - agcctgcgct gattccggcg gataccgcca agatcctgcg cacgcccggc ac -#ccgcgggt 9420 - - cccgtatagc tgccgtcggc acgcttgtcc gcctgcgctt ctggcgcgct gg -#cgccggcc 9480 - - tcctgcaact gctcggcaga ccaatctgat gaaggcgggg cggccatggt gc -#ggcgcccc 9540 - - gtctcctgtc ctcacaccgc cgcgagcgcc tcttccagcg tcccgctgtc ga -#tccgcagg 9600 - - cgtcccacca tcagccagag atagacgggc agcgaatcgt cgttgaagcg ga -#agcggcgc 9660 - - tccccgtcct gcgcatcgct ctccaggccg agctggcggc tcagcgcgtc ga -#gttcctgc 9720 - - tcgacctgcg ccgcagtgat cgtgctcccc ggcagcagct cgacgactgc ct -#ggccggtg 9780 - - aaccaaccat cggtcgaacg cgacgcctcg cccagcgcgg cgaccagcgg at -#cgtagcga 9840 - - ccgccgacga acttgcgcat ctccagcacg gcgcgcggcg acatccggcc tt -#ctatttcc 9900 - - aggatggcct ggtcgagcgc gcggcgcaga tggcccagat cgacggtcag cc -#gcccctgg 9960 - - tcgagcgcct cgagcgccgc atggtggcac agcagccgcg cgaaataggg cg -#accccagc 10020 - - gccagcaggt ggatgatccg ggtgaggttc ggatcgaagc gcaggcccga gg -#cggtctcg 10080 - - ccgagcgcga tcatctcctg tacctcggtt tcctcgagcc gcggcatcgg ca -#ggccgatg 10140 - - atgttgcggc ggatcgaggg tacgtagccg acgagttcct gcaggttcga cg -#agacgccg 10200 - - gcgatcacca gctgtacgcg cgcggagcgg tccgagaggt tcttgatcag tt -#cggcgacc 10260 - - tgctggcgga accgggtatc cgtcacgcgg tcatattcgt cgaggatgat ca -#gaacgcgg 10320 - - gtgccggtga tgtcggcgca cagatcggcg agttcgcccg aatcgaacga tc -#cggtcggc 10380 - - aggcgatcgg cgaggcttcc gcccgattcc gcctcgcccg cattgggcga ga -#cgccgcga 10440 - - tggaacagca gcggcacatc ctctagcacc gcgcggaaca ggtcggcgaa gt -#tggcattg 10500 - - gcgccgcagg tcgcgtagct gacgatgtag ctggattcac gcgccacgtc gg -#tcagcaca 10560 - - tggagcagcg aggtcttgcc gatgccgcgc tcgccataga gcacgacatg gc -#tgcgctgg 10620 - - ctctcgatcg ccgagatcag ccgcgccagc acctcgaggc gaccggcaaa gc -#tcgagcgg 10680 - - tccgccaccg gctgggtggg cgtgaagaag gtggcgagcg caaaccgcgc gc -#gggtgatc 10740 - - tcgcgacgct cttcccggcg ccggtcgagc gggcgatcga gcgcggaagc gc -#gaaaggtc 10800 - - ggaaagtcgg gtcgcccgcg gcccgcatgc gcgtcgcgat ggggaacgac gg -#tggcggcc 10860 - - agcgggaaat atccgtcctc ctccggtacg tcccgacgcc caaagggcca ca -#agaacttc 10920 - - agcgcggatc ctacagccac tcgaacacct cttaatttcg gacgccgcca cg -#ctcggcag 10980 - - cgaacccctg gttcgcgcct tctggcgcct cccccaaacg atccggcccc gc -#ctgtatca 11040 - - gcggcgcttg aaaaactcgt acggtttgat cacgaacgca atgtacgcca gc -#accaatac 11100 - - aatcgtgagg attgcgaaaa catgatagtt ttcgttcccg agataattgg cg -#acggcaca 11160 - - tccgaccgcg ggaggcaaat agctgatcat cgtgtcgcgc actaccgaat cc -#gcctggga 11220 - - tcgttgcaag aagatcacga tcaggccggc gaatatcgcg atggtcaccc aa -#tcataggg 11280 - - cgtctgcatg catgtccttt cttttcggcg ccggaatcga aggacttccg ac -#gtcgcccg 11340 - - aaccgcacta gcagcggacg gtgcaactcg ctagataccg cggtgcagga ta -#aaagctcg 11400 - - ttaaaacgcg accctaggaa tagcgcggta gcgccggcat gcgagaggtc gg -#gcatgcgg 11460 - - aaggccgaag cggccgggac agcaccggat gggaggatat tcccgtagtg gg -#agtggcga 11520 - - ggccatggca tcctcagatc cggttgcttg tactggaggc cattgataat ga -#agccagga 11580 - - cccgggggaa cattcgtgcc agtaaaagac gttcagcaag cggtagaagt gc -#gcctcggc 11640 - - gatcgtgtct cgcgatcgtg ccgcgtgctc gcgctgcttg cgacggcaac gg -#cgatccag 11700 - - cccgcgctcg cgcagcgaca ggcgttcacg ccacgcccga gcggcagcga gc -#gccagatc 11760 - - agcgtgcatg caacgggaca gctcgagtac aacgacaatg tcgtgctcaa cg -#acccgcgc 11820 - - atcaccagcg gcgcgcgcgg cgacgtgatc gcctccccct ccctcgatct ga -#gcattgtc 11880 - - ctgccgcgcg cgaccggaca gctctatctc gcgggcacgg tgggctatcg ct -#tctatcgt 11940 - - cgctacacga acttcaatcg cgagaatatc tcgctcaccg gcggcggcga cc -#agcggatc 12000 - - gcgtcctgcg tggtgcatgg cgaagtcggc tatcagcgcc acctgacgga cc -#tgtccagc 12060 - - gtcctcgtcc aggatactgc gcccgcgctc aacaacacgg aagaagcgcg cg -#cctattcc 12120 - - gcggacatcg gctgcgggtc cgcctacggc ctgcgccctg cacttgccta tt -#cgcgcaac 12180 - - gaggttcgca acagcctcgc ccagcgcaag ttcgccgatt ccgacaccaa ca -#cggtcact 12240 - - gcccagttgg gcctgacgtc gccggcgctg ggcaccgtgt cggtgtttgg ac -#gcatgtcc 12300 - - gacagcagct acatccatcg cacggtaccg ggggtcagtg gccgcgacgg ca -#tgaagagc 12360 - - tatgcggccg gcgtccagct cgagcgggcg gtctccagcc ggctgaattt cc -#gcggctcc 12420 - - gtcaattatt cggaggtcga ccccaagctc gcctcgacgc cgggcttcag cg -#ggatcgga 12480 - - ttcgatctgt cggcggtata ttcgggcgat caatatggcg tgcagctcct tg -#cgtcgcgc 12540 - - aacccgcagc cctccacgct gctgttcgta ggctatgaaa ttgtgacgac cg -#tgtcggca 12600 - - acggcaaccc gtaagctgag cgatcggacc caactctcgc tacaggccac ca -#agacctgg 12660 - - cgcgagcttg cctcttcgcg gttgttcact cttgcgccga cgacgggcaa cg -#acaacacg 12720 - - ctgacgctgt tcggcaccgt gaacttccga cccaatcctc ggctgaactt ct -#cgctgggt 12780 - - gcgggctata acaagcgcac cagcaatatt gggctgtatc aataccgctc ca -#aacgtatc 12840 - - aatctcacga cgtcgctgtc gctctgacaa gggccgtatt catgcatgac aa -#acaccgtt 12900 - - tcgtgatcct ttcggcgctc accggaattg ccgtactcgc cgcgcccgcg gc -#agcgcaga 12960 - - ttcccacccg gtccgttccg acgccggcgc gggcgcgccc ggcgaccccg cc -#agcggccc 13020 - - cgcagcagca gacgacggca gtgccgacaa cggcagccac cgccaccccg cc -#ggctgcgg 13080 - - gtgcggcgcc ggccggctac aagatcggcg tcgacgacgt gatcgaggcg ga -#cgttctgg 13140 - - gccagtcgga cttcaagacc cgcgcgcgcg tgcaagcgga cggtaccgtc ac -#ccttccct 13200 - - atctcggcgc cgtgcaggta cggggcgaga ccgccgtcac gctggccgag aa -#gctcgccg 13260 - - gcctgctgcg cgcgggtggc tattacgcga agccgatcgt cagcgtcgaa gt -#cgtcagct 13320 - - tcgtcagcaa ctatgtgacg gtgctgggcc aggtgaccac ggccggcctg ca -#gccggtgg 13380 - - atcgcggcta tcacgtctcg gagatcatcg cgcgcgccgg cggccttcgc gc -#cgatgcgg 13440 - - ccgatttcgt ggtgctcacc cgcgccgacg gcaccagtgc caagctgaac ta -#caagcagc 13500 - - tggcccaggg cggcccggag caggatccgg tggtcacgcc tggcgacaag ct -#gttcgtgc 13560 - - cggaagtcga gcacttctac atttatggcc aagttaacgc gcctggggta ta -#cgcgattc 13620 - - gaacggacat gacgctccgt cgcgcgctgg cacaaggcgg cggccttacc cc -#cgccggct 13680 - - cgtcgaagcg agtgaaggtc tcgcgcgacg gccaggaaat caagttgaag at -#ggacgatc 13740 - - cgatcaagcc tggcgacacg atcgtcatcg gcgagcggtt gttctgatct ag -#gcaatgtt 13800 - - gacagcggac gaggcccacc agtgaatatc attcagttct tccgcattct ct -#gggtgcgc 13860 - - cggtggatca tcctcccggc gtttctcgtc tgcgtcacca ccgcggcgct gg -#tggtccag 13920 - - ttcctgcccg aacgctaccg cgcgaccacg cggctggtgc tcgacacctt ca -#agcccgat 13980 - - cccgtcaccg gccaggtgat gaactcgcag ttcatgcgcg cctatgtcca ga -#cgcagacc 14040 - - gagctgatcg aggactatgc gacctccggc cgcgtggtcg acgaactggg ct -#gggccaac 14100 - - gatcctgcca acatcgctgc cttcaacgcc tcgtcctcgg cggcgaccgg cg -#acattcgc 14160 - - cgctggctcg caaagcagat ctcggacaac accaaggcgg atgtgatcga gg -#gcagcaac 14220 - - atcctcgaaa tctcctactc ggacagctcg cccgagcgtg ccgagcgtat cg -#ccaacctg 14280 - - atccgcaccg cattcctcgc ccagtcgctc gccgccaagc gccaggcggc gg -#cgaagtcg 14340 - - gccgactggt acacccagca agcggaagcg gcacgccagt cgctgctcgc gg -#cggtgcag 14400 - - gcgcgcaccg acttcgtgaa gaagtccggc atcgtgctga ccgagaccgg tt -#cggatctc 14460 - - gatacgcaga agctcgcaca gctccagggc gcgagcgcga taccgtcggc ac -#cggtcgtc 14520 - - gcggccgcca gcggcatggg cccggcgcag ctccagcttg cccagatcga cc -#agcagatc 14580 - - cagcaggcgg ccaccaatct cggcccgaac cacccggcct tccaggccct gc -#agcgccag 14640 - - cgcgaggtgc tcgcccgcgc agcggcggcg gaacgcagcc aggcaagcgc ca -#gcggcccc 14700 - - ggccgcggcg cgctggaaag cgaagccaat gcccagcgcg cccgcgtgct cg -#gcaaccgc 14760 - - caggatgtcg acaaggtcat gcagctccag cgggacgtca cgctgaagca gg -#accagtat 14820 - - atgaaggcgg cccagcgcgt cgccgatctg cgcctggaag caagcagcaa cg -#acacgggc 14880 - - atgagcacgc tgagcgaagc cagcgcgccg gaaacgccct attaccccaa gg -#tgccgatg 14940 - - atcatcggcg gcgcggccgg cttcggcctc ggcctcggcg tgctggtcgc gc -#tgctcgtc 15000 - - gaactgctcg gtcgccgcgt gcgcagcgcc gaggatctcg aagtggcggt cg -#atgcgccg 15060 - - gtgctgggcg tgatccagag ccgtgcctcg ctcgccgcac gcctgcgccg cg -#cccaagaa 15120 - - accctcggcg accgcgccga aacgcacgga gcttcagtaa actgatggac gc -#gatgacca 15180 - - gcgaaccgct gcccgaaggc gagcgcccga gcgccgttcc gacgacgccc ga -#caccaccg 15240 - - gcgtcctgga atatcagctc gtcctgtccg acccgaacgg catcgaagcg ga -#agccattc 15300 - - gcgcgctgcg cacccgcatc atggcgcagc acctgcgcga gggccgccgc gc -#cctggcga 15360 - - tctgcggcgc ctcggccggc gtcggctgca gcttcaccgc cgccaacctc gc -#gacggcgc 15420 - - tggcgcagat cggcatcaag accgcgctgg tcgatgccaa tctgcgcgac cc -#gagcatcg 15480 - - gcagcgcctt caacatcgcc gccgacaagc cgggcctcgc cgactatctc gc -#ctcgggcg 15540 - - atatcgacct cgcctcgatc atccacccga ccaagctgga ccagctgtcg gt -#gatccatg 15600 - - ccgggcatgt cgagcacagc ccgcaggaac tgctgtcctc cgagcagttc ca -#cgacctcg 15660 - - tgacgcagct gctgcgcgag ttcgacatca cgatcttcga caccacggcc gc -#gaacacct 15720 - - gcgccgatgc gcagcgcgtc gcacatgtcg ccggctatgc gatcatcgtg gg -#gcggaagg 15780 - - attcgagcta catccgcgac gtcaacacgc tcacccgcac gctgcggtcg ga -#ccgcacca 15840 - - acgtcatcgg ctgcgtcctg aacggctatt gaattggatt ccatgaccgc ga -#ctgcgctg 15900 - - gagcggcagc aaggacggcg acaggggggc tattggctcg cggtcgccgg cc -#ttgcggca 15960 - - ctcgccattc ccactttcgt cacgctcggc cgcgaaacct ggagcgccga ag -#gtggcgtg 16020 - - caggggccga tcgtgctggc gaccggcgcc tggatgctgg cgcggcaacg cg -#acagcctc 16080 - - gtggcgctcc ggcgccccgg caatctggcg ctgggcgcat tgtgcctgtt gc -#tggcgctg 16140 - - ggcatctaca ccgtcggtcg cgtgttcgac ttcatcagca tcgagacgtt cg -#ggctggtc 16200 - - gcgaccttcg tggcggctgc gttcctctat ttcggcggcc gggcgctgcg cg -#ctgcgtgg 16260 - - ttcccgacct tgtggctgtt cttcctcgtg ccgccgccgg gctggatcgt cg -#atcgcgtc 16320 - - accgcgccgc tcaaggagtt cgtctcctat gccgccaccg gcttcctgtc ct -#ggctggac 16380 - - tatccgatcc tgcgccaggg cgtgacgctg ttcgtcggcc cctatcagct gc -#tggtcgag 16440 - - gatgcctgtt cggggctgcg ctcgctctcc agcctcgtcg tcgtcacgct gc -#tgtacatc 16500 - - tacatcaaga acaagccgtc ctggcgctac gcgctgttca tcgccgcgct gg -#tgatcccg 16560 - - gtcgcggtga tcaccaacat cctgcgcatc gtcatcctcg tgctgatcac ct -#atcatatg 16620 - - ggcgacgagg ccgcgcagag cttcctccac gtctccaccg gcatggtgat gt -#tcgtggtc 16680 - - gcgctgctct gcatcttcgc catcgactgg gtggtcgaac agctcttcac ac -#ggcgccgg 16740 - - aggccccatg ttcaaccggc gtgacctgct gatcggcgcg ggctgcttcg cc -#gccgccgg 16800 - - cgcctcgctc ggcctcaagc cgcaccgtcg catggacctg ctcggtgcga cc -#aagctcga 16860 - - tgcgctgatg cccaaggcat ttggcggctg gaaggccgag gataccggtg cg -#ctgatcgc 16920 - - ccccgcgcgc gaaggcagcc tggaagacaa gctgtacaac caggtggtcg cc -#cgtgcctt 16980 - - ttcgcgcgcc gacggcaccc aggtgatgct gctgatcgcc tatggcaacg cc -#cagacgga 17040 - - tctgctgcag ctccaccgac cggaagtctg ctacccgttc ttcggcttca cc -#gtggtcga 17100 - - gagccacgag cagatcatcc cggtgacgcc gcaggtgacg attcccggac gg -#gcgctgac 17160 - - cgcgaccaac ttcaaccgca ccgagcagat cctctactgg acccgcgtgg gc -#gaatatct 17220 - - gccgcagaac ggcaacgagc agctgttcgc ccgcctcaag agccagctcc ag -#ggctggat 17280 - - cgtcgacggg gtgctggtcc gcatctcgac tgtgacggcg gaagccaagg ac -#ggcctcaa 17340 - - cgccaatctc gatttcgcgc gcgagctggt gaagacgctc gatccgcgcg tg -#ctgcgccc 17400 - - gttgctcggc acgcaggtaa cgcgcgacct ggcgccgcgc gcctgaacga aa -#aaggggcg 17460 - - gcgcagaccg ccgcccctcc ctctccttct cgtcgcgtac ccgcgctcag cg -#ctcgtgca 17520 - - gcgcgtcgct gccggtttcg agcatcgggc cgacgagata gctcagcaat gt -#ccgcttgc 17580 - - cggtgacgat gtcggcactg gcgatcatgc ccggccgcag cggcacgtgc cc -#gccattgg 17640 - - cgatgacata gccgcggtcc agtgcgatcc gcgccttgta gaccggcggc tg -#gccctcct 17700 - - tcacctgcac cgcctcgggc gcgatgccca ccaccgtgcc ggggatcatg cc -#atagcggg 17760 - - tgtgcgggaa cgcctgcagc ttcaccttta ccggcatgcc ggtgcgcacg aa -#gccgatat 17820 - - cgctgttgtc caccatcacc tcggcctcga gccgggcatt gtccggcacc ag -#cgacagca 17880 - - gcggcttggc gccctccacc acgccgcctt cggtgtggac ctgcagctgc ga -#gaccgtgc 17940 - - cgctgaccgg cgcgcgcagt tcgcggaacg aactgcgcag attcgccttg gc -#gacttcct 18000 - - cgctgcgcgc ccgcacgtcg tcctgcgcct tcaccagatc ctgcaacacc tg -#cgcgcgcg 18060 - - cctcctcgcg cgtcctgatc gacatgctgc tggcactgcg cgactgctga cc -#aagcttgg 18120 - - ccaccgtcgc ccgcgccgcg gtgaggtcct gccgttcgga aatgagctgg cg -#gcgcatct 18180 - - cgaccacgcg cagcttcgag acatagccct tggcggccat cgcctcgttc gc -#ggcgatct 18240 - - gctgctcgag cagcggcagc gattgttcca gcttgcgaac ctgcgcctgt gc -#ctcggccg 18300 - - aggcggaagc ggcggcaccg ctgtccgatc ggccgccggc aagcatcgcc tc -#gatctggc 18360 - - cgagccgcgc gcgtgcgagg ccgcgatgcg tctcgacctc cgcggcgcct gc -#ggcggcgg 18420 - - gcgcggcgaa gcggaagccc tttccgtcca gcgcgtcgat gatcgcctgg tt -#gcgcgcgg 18480 - - catcgagctg ggcgctgagc agcgccacgc gcgcctgcgc ggcttcggct gc -#cgacatgg 18540 - - tgggatcgag cgtgatcagc acctggccct tctgaacctt ctgcccctcg cc -#caccagaa 18600 - - tgcgccggac gataccgctt tcgggggact gcacgatctt ggtctcgccg at -#cggggcga 18660 - - tgcggccctg cgtcggcgcc accacttcca cgcggccgat tgccagccag gc -#ggtggtga 18720 - - tcgccagccc cgccaccatc acccggccgg tgaggcgcgc ggtgggcgac ac -#cggacgtt 18780 - - cgatgatctc gagcgcggcc ggcaggaatt cggtatcata ggcatcggcg cg -#agcgggca 18840 - - gcacggtgcc gcgcatgcgg gcgatcgggc cgccgcggcc gatcggaaca ac -#ggcgttca 18900 - - tgcggcaatc tccccatatc cgctttggcg gcggtgcagg tcggcatagc gg -#ccgcccaa 18960 - - gcgtagcagt tcgtcatgcc ggccgctctc gacgatgcgg ccctgctcca gc -#gtgatgat 19020 - - ccgatcgcag gcgcgtaccg cggacaggcg gtgggcgatg atcaccagcg tg -#cggcccgc 19080 - - cgagatggcg cgcagattgt tctggatcag ctcctcgctc tcggcatcca gc -#gcggaggt 19140 - - cgcctcgtcg aacaccagga tgcgcggatt gccgaccagc gcgcgggcga ta -#gcgagccg 19200 - - ctggcgctgg ccgcccgaca ggttgacgcc gcgctcgacg atctcggtgt ca -#tagccgcg 19260 - - cggctgacgc aggatgaagt catgcgcacc cgccagcgtc gccgccgcca cg -#acatgctc 19320 - - gaacggcatc gccgggttgg acagcgcaat gttctcgcgg atcgagcggc tg -#aacagcag 19380 - - attttcctgc agcacgacgc cgatctgccg gcgcagccag gcgggatcga gc -#tgggccac 19440 - - atccacctcg tcgaccagca cgcggcccag atcgggggtg ttgaggcgct gc -#agcagctt 19500 - - ggccagcgtc gacttgcccg accccgagga gccgacgatg ccgagcgacg tg -#ccggcggg 19560 - - gatgtcgagc gtgatgtcgc tcagcaccgg cggctggtcc tcggcatagc gg -#aaggtcac 19620 - - gttttcgaag cggatcgcgc cgcgcagcac cggcagcgtc gcggcggagg cc -#ggccgcgg 19680 - - ctccaccgga tggttgagca cgtcgccgag gcgctcgatc gcgatgcgga cc -#tgctggaa 19740 - - gtcctgccac agctgggcca tgcggatcac ggggccggaa acgcgctggg cg -#aacatgtt 19800 - - gaacgccacg agcgcgccga cgctcatcgc gccaccgatc acggccttgg cg -#ccgaagaa 19860 - - caggatcgcc gcgaagctca gcttggagat cagctcgatc gcctggctgc cg -#gtgttggc 19920 - - gacgttgatc agccgctgcg acgaggcggt ataggcggcg agctgacgtt cc -#cagcgatt 19980 - - ctgccagtgc ggttcgactg cggtcgcctt gatggtgtgg atgccggaga cg -#ctctcgac 20040 - - gagcagcgcg ttgctggcgg agctcttctc gaacttgtcc tcgacacgcg tg -#cgcagcgg 20100 - - gcccgcgacg ccgaacgaga ccatcgcata ggcgaccagc gacacgatca cg -#acgccgaa 20160 - - cagcatcggc gagtagaaca gcatcgcgcc gaggaacacg accgtgaaca gc -#ggatcgac 20220 - - catcaccgtc agcgacgcat tggtgaggaa ttcccggatg gtctcgagct gg -#cggacccg 20280 - - ggtgacggtg tcgcccaccc gccgcttttc gaaatagccg agcggcagcg cc -#agcagatg 20340 - - gtggaacagc cgcgcgccca gctcgacgtc gatcttctgc gtcgtctcgg tg -#aacaggcg 20400 - - cgtgcggatc cagcccagcg ccacctccca gaccgacacg gccaggaagg cg -#aaggcgag 20460 - - cacgctcagc gtgctcatgc tgttgtggac cagcaccttg tcgatcacgc tc -#tggaagag 20520 - - cagcggcgcc gcgaggccga gcaggttgag cgccagggtg atgcccagca cc -#tcgagaaa 20580 - - cagcctgcga taccgctgga actgtgcggc gaaccaggag aaaccgaatc gc -#agcgcctg 20640 - - gccggccacg gcgcgcgtcg tcagcagcac gagcgtgccg gaccacagcg ca -#tccagccc 20700 - - ctcgcggtcg acctgttcgg gggcgtggcc gggacgctgg atgatcacgc ca -#tgctcggt 20760 - - caggccaccg atcacgaacc agccctccgg gccgtcggcg atggccggca gc -#ggctggcg 20820 - - ggccagaccg ccgcgcggca cgtccaccgc cttggcgcgc acgccctgct gg -#cgcttggc 20880 - - gagcaggatc aggtcgtcga cgctggcacc ctcggcatgg cccagcatgt gc -#cgcagctg 20940 - - ttcgggggtg acggcgatgt tgtggacgcc gagcagcagc gacagcgcca ca -#agcccgga 21000 - - ttcgcgcaat tcgccctcgc gctcggcggc agcctgggcg gcgaacgcgc cc -#tggagctg 21060 - - tgcctgcatc tcgtcgcgtg tcattccggt actctgcctc catggcgcta ct -#gatcgcag 21120 - - ccatgatgaa cgagctcggt aaagactcgc ttaagccaga tttttctgtg gt -#ttatacct 21180 - - attgccgggg atgccggacc ggaccggatc ggcagacggc agcctgcgtt ag -#tcgggcct 21240 - - taaagcgttg ccgctagcac aaggacaaga attttatcgg agagggtcgg ga -#accatgcc 21300 - - cacgcatgaa ggttgcagcg cagcaatatc gacggatcgc ctcggagccc ga -#atgctgca 21360 - - tccgcgaagt gactttcgcc aaagcagcta taggatggcc cggggcttga tt -#gccgccgt 21420 - - gcgatcagca taagcgatcc atggtcgcca aaatctgtca tccttggtaa ca -#atcatgca 21480 - - gccgctaagg aagatgtgca cgtctgacga tgctttcttc cgcaccccat gc -#gccgctga 21540 - - ctctggtaga ttgaccgtgg cctccattgc tcatcgtctc gaaaaaggac cc -#tctggtcg 21600 - - ccgcgcggac ttccgggaat cgatttgtcc cgttatagtg caatgcaaca gg -#ccgaatcg 21660 - - gccgctgtca gcgtgcacaa tccgttgagg gagcccgacg aggcaatgaa cg -#cttttgaa 21720 - - gcacagcgcg cctttgagga gcagctccgg gcccatgccc gttctgcccc ca -#gcgccgca 21780 - - cccatgctgc gacgttccac gatccgcatg atcctctaca ccgaattgct gt -#tgctcgac 21840 - - agcatcgcaa ttctactggg gttctacatc gcggcctgct cgcgcgacgg ca -#actggctg 21900 - - tcccttgcgg gcgtcaatgt cggcatcttc ctcctgccga tcacgctcgg ca -#ccgcgctc 21960 - - gccagcggca cctattcgct gagctgcctg cgctacccgg tcagcggggt ga -#agagcatc 22020 - - ttctcggcgt tcttcttctc ggtgttcatc gtgctgctgg gcagctacct gc -#tcaccgcg 22080 - - gagctgccgc tgtcgcgcct gcagctcggc gagggcgtgc tcctggcgct ca -#gcctggtg 22140 - - acgatctgcc gccttggctt ccgctggcac gttcgtgcgc tgacacgcgg ca -#cgctgctc 22200 - - gacgagctgg tgatcgtcga cggcgttgcc ctggaggtcg cgagcggcgc gg -#tcgcgctc 22260 - - gatgcgcgca tcatcaacct cacgcccaac ccgcgcgatc cgcagatgct gc -#atcgcctc 22320 - - ggcaccaccg tggtgggctt cgaccgggtc gtcgtcgcct gcaccgagga gc -#accgggca 22380 - - gtatgggcgc tgctgctcaa gggcatgaac atcaagggcg agatcctcgt cc -#cccagttc 22440 - - aacgcgctgg gcgcgatcgg cgtcgactcc tatgagggca aggacacgct gg -#tcgtgtcc 22500 - - cagggcccgc tcaacatgcc gaaccgcgca aagaagcggg cgctcgatct gc -#tcatcacc 22560 - - gtccccgcgc tggtcgcgct ggcgccgctg atgatcgtgg tcgcgatcct ga -#tcaagctg 22620 - - gagagccccg gccccgtctt cttcgcacag gaccgcgtcg gccgcggcaa cc -#gactgttc 22680 - - aagatcctca agttccgctc gatgcgcgtt gcgctctgcg atgcgaacgg ca -#acgtctcg 22740 - - gccagccgcg atgacgatcg catcaccaag gtaggccgga tcatccgcaa ga -#ccagcatc 22800 - - gacgagctgc cgcagctgct caacgtgctg cgcggcgaca tgagcgtcgt cg -#gcccgcgc 22860 - - ccgcacgcac tcgggtcgcg cgccgccaac catctcttct gggaaatcga cg -#agcgctac 22920 - - tggcaccgcc acacgctcaa gccgggcatg acgggcctcg cgcagatccg cg -#gcttccgc 22980 - - ggcgcgaccg atcgccgcgt cgatctcacc aatcgcctgc aggcggacat gg -#agtatatc 23040 - - gacggctggg acatctggcg ggacgtcacc atcctgttca agacgctgcg cg -#tgatcgtg 23100 - - cactccaacg ccttctgatc gcggagggga gcaacgcgag caccgcttgg tg -#caagagca 23160 - - ttgacatccg ccctgcttct gcatttgtca ttttatcatt gtcgttgcgg gc -#ccgcccgc 23220 - - gccatggggg attttgaatg aagggtatca tccttgcggg gggcagcggc ac -#gcgcctct 23280 - - accccgcaac gctgtcgatc tcgaagcagc tgcttcccgt ctatgacaag cc -#gatgatct 23340 - - tctaccccct gtcggtgctg atgctcacgg gtatccggga catcctgatc at -#ctccaccc 23400 - - cgcgcgacct gccgatgttc caggcgctgc tcggcgacgg ttcggcattc gg -#catcaacc 23460 - - tgagctatgc cgaacagcct tcgcccaacg gccttgcgga agccttcatc at -#cggcgccg 23520 - - atttcgtcgg caacgatccc agcgcgctga tcctcggcga caacatctat ca -#cggtgaaa 23580 - - agatgggcga gcgctgccag gcagctgcgg cccaggcatc gcagggcggc gc -#gaacgtgt 23640 - - tcgcctatca tgtcgacgat cccgagcgct acggcgtggt cgcgttcgat cc -#ggagacgg 23700 - - gcgtcgctac cagcgtcgag gaaaagccgg ccaaccccaa gtccaattgg gc -#gatcaccg 23760 - - ggctttattt ctacgacaag gacgtggtcg acatcgccaa gtcgatccag cc -#ctcggcgc 23820 - - gcggcgaact cgagatcacc gacgtcaacc gcatctacat ggagcgcggc ga -#cctccaca 23880 - - tcacccggct cggtcgcggc tatgcctggc tcgacaccgg cacgcatgac ag -#cctgcacg 23940 - - aggccggctc gttcgtccgc acgctggagc accgcaccgg cgtgaagatc gc -#ctgcccgg 24000 - - aggaaatcgc cttcgagagc ggctggctgg gcgccgacga tctgctcaag cg -#cgccgccg 24060 - - gcctcggcaa gacggggtat gccgcctatc tgcgcaagct ggtagccgcg gc -#atgaccca 24120 - - ggtgcatcac cacgcgctat cgggcgtcat cgagttcacc ccgcccaagt ac -#ggcgatca 24180 - - ccgcggcttc ttctccgagg tgttcaagca gtccacgctc gacgccgaag gc -#gtcgaggc 24240 - - gcggtgggtg caggacaatc agagcttctc ggccgcaccg ggcacgatcc gc -#ggactgca 24300 - - cctgcaggcg ccgcccttcg cccaggccaa gctggtgcgc gtgctgcgcg gc -#gcgatcta 24360 - - cgacgtcgcg gtcgacattc gccgcggctc gcccacatac ggccagtggg tc -#ggcgtcga 24420 - - gctttcggcg gacaagtgga accagctgct ggtgccggcc ggctatgcgc at -#ggcttcat 24480 - - gacgctcgtc ccggattgcg agatcctcta caaggtcagc gccaaatatt cg -#aaggaatc 24540 - - ggagatggcg atccgctggg atgatcccga tctcgccatc acctggccgg ac -#atcggcgt 24600 - - cgagccggtg ctctccgaaa aggacgcggt cgctaccccg ttcgccgaat tc -#aacacccc 24660 - - cttcttctat cagggctgat ccatgcagca gaccttcctc gttaccggcg gc -#gccggctt 24720 - - catcggctcg gcagtggtac gccacctcgt tcgccagggc gcgcgcgtca tc -#aatctcga 24780 - - caagctcacc tatgcgggca acccggcctc gctgaccgcg atcgagaacg cc -#cccaacta 24840 - - ccgcttcgtc cacgccgata tcgccgacac cgcgacgatc ctgccgctgc tg -#cgcgaaga 24900 - - gcaggtcgac gtggtgatgc acctcgccgc cgagagccat gtcgatcgct cg -#atcgacgg 24960 - - cccgggcgag ttcatcgaga ccaacgtcgt cggcaccttc aagctgctcc ag -#gcggcgct 25020 - - gcaatattgg cgcgagctgg aaggggagaa gcgcgaggct ttccgcttcc ac -#cacatttc 25080 - - caccgacgag gtgttcggcg acctgccgtt cgacagcggc atcttcaccg aa -#gagacgcc 25140 - - ctatgatccc tcctcgccct attcggcgtc gaaggcggcc agcgaccatc tg -#gtccgcgc 25200 - - ctggggtcac acctatggcc tgcccgtggt gctgtcgaac tgctcgaaca at -#tacgggcc 25260 - - gttccacttc cccgagaagc tgatcccgct gaccatcctc aacgcgctgg aa -#ggcaagcc 25320 - - cctgcccgtc tacggcaagg gcgagaatat ccgcgactgg ctgtacgtcg ac -#gatcacgc 25380 - - caaggcgctg gcgacgatcg ccacgaccgg caaggtcggc cagagctaca at -#gtcggcgg 25440 - - ccgcaacgag cgcaccaacc tgcaggtcgt cgagacgatc tgcgacctgc tc -#gatcagcg 25500 - - cattccgctg aaggatggca agaagcgccg cgagctgatc accttcgtca cc -#gatcgccc 25560 - - cggccatgac cgccgctacg cgatcgacgc gaccaagctc gagaccgaac tg -#ggctggaa 25620 - - ggccgaggag aatttcgaca ccggcatcgc cgcgacgatc gactggtatc tc -#gagaatga 25680 - - atggtggtgg ggtccgatcc gctccggcaa atatgccggc gagcggttgg gg -#cagaccgc 25740 - - ctgatgcgca tcctcgtcac cgggcatgac ggccaggtcg cccaggcgct gg -#gcgaacag 25800 - - gcggagggcc atgagctgat cttcaccagc tatcccgagt tcgatctctc ca -#agccggag 25860 - - acgatcgagg cggcggtggc gaagatccag cccgagctga tcgtgtcggc gg -#ctgcgtat 25920 - - acggcggtcg acaagtccga gagcgagccc gagctcgcca tggcgatcaa cg -#gcgacggc 25980 - - cccggcgtac tggcgcgcgc gggcgcgaag atcggcgcgc cgatcatcca tc -#tgtcgacc 26040 - - gactatgtgt tcgacggcag cctggaccgc ccgtggcgcg aagacgaccc ca -#ccggtccg 26100 - - ctcggcgtct atggcgccac caagctggcc ggcgagcaag cggtgcaggc ct -#cgggcgcg 26160 - - accaacgcgg tgatccggct cgcctgggtc tacagcccgt tcggcaacaa ct -#tcgtcaag 26220 - - acgatgctgc gcctcgccga gacgcgggac acgctgaacg tggtcgagga cc -#agcagggc 26280 - - tgcccgagct cggcgctgga catcgccacg gcgatcctca aggtcgtcgg cc -#actggcag 26340 - - cagaacggcg ccaccagcgg cctgtatcac ttcaccggat cgggcgagac ca -#actgggcc 26400 - - gacttcgcgc gcgcgatctt cgcggaaagc gccaagcacg gcggtccgac cg -#ccgaggtg 26460 - - accggcattc cgacctccgg ctaccccacc ccggcgaagc gcccggccaa tt -#cgcggctc 26520 - - aattgcgaca agttcgccga aaccttcggc tatcgtgcac ccgcctggca gg -#actcggtg 26580 - - gcggaagtgg taggccgcct cctggcataa aatgcccggc ccgaccctgt gc -#gcggcggg 26640 - - gtggctgcgc actccggtcg ggtttcatcg acatcgccgg ctgcggggag ca -#tcaccgat 26700 - - gctccccgat cagcgccagg ccgtcacttc ctgaacggcg cgaccagggg ct -#tgatcgtc 26760 - - ttgaacacgg cctcacgcag cgtccgcacg ggcgcggcga cgaggtgatc ga -#acgcgagc 26820 - - gtcatcccgc tcacccgctg gggtgcgacg tcgctgcgga tcttgaacga tt -#cgaccacc 26880 - - tcgatatcgg aaaccagccg ccccttgatg cggttgatga cattctcgcc at -#gcaccacc 26940 - - tgcagccata ccggccgccc ggcgacctgg gtgatcttcc acttctggcc ca -#gctcatga 27000 - - tggggcttgg cccagatcgt ctcgacgctg gcgagatcgc gctcgaccag cg -#aggtgaac 27060 - - ggattgctgt ggtccgcagc ggtgtagagc cggccctggc gcatcgcgat gc -#cctgggtg 27120 - - aagttcagca ccgtctgtgc cggcgcatcc ttcgccgcgg cctgcacccg tg -#ccacgaag 27180 - - tcgttcgaaa gcgcgtcgtc attgtccagc cgcgtggtga cgatcagctg ct -#cgccgggc 27240 - - gtcgccagcg ccttcacgtc gtccgcgatc atcgccttgt cgaacatcgc ga -#cgtagcgc 27300 - - ggcgtgaagt tgtagatctg ccgatcgcgc tcgatccgct cgcggaactc gg -#cgggggtg 27360 - - tccttgtcga agtagatgag ccagtggaag ttgcgctcgg tctggcccgc ga -#tgctcggc 27420 - - aggcagaact gctcgaacag cccgaaacgg cggtcgagcc aacccggcga at -#tgcggatc 27480 - - gccacctcgc ggcccgggct ggcgatgttg aagcgcgtca ggatcacgtg aa -#gcatcggt 27540 - - tcgatcagcc ccggtctagc aaaacgaaga aagcccggcc gctacaacgg cc -#ttgttcga 27600 - - acaacgcgca agaaacaggg tacacgcgaa cggcacgttc gtcttcgccc ac -#cccgctgg 27660 - - ttgccgccat tcccacgaac ggttacggga tattccggaa ctgggcaacc gg -#ggattgct 27720 - - gcactgcgca atgacacgcg gccggaatga caaacggctt gccgcccgcg cc -#ccccgcgc 27780 - - ctaaccctcc gcccgtgccc gacgcccgtc ccgatcgcat tgccaccggc ct -#ggcgcttc 27840 - - gcctgttcgc cattgcctgc ctgtcgacca tgtcggcgct catcaagatg tc -#ggaactgc 27900 - - gcggcgcctc gctgatcgag acgatgttcc accgccagct ctgggcggtg cc -#gctggtca 27960 - - ccttgtgggt ggtgatgggc ccggggctca agtcgctcaa gacgcagcgc tt -#cggcgcgc 28020 - - atgtctggcg caccgcggtg ggcctcaccg gcatgatctt caccttcggc gc -#ggtgatcc 28080 - - tgctgcccct ggccgaggcg cagaccttcc agttcaccgt gcccatcttc gc -#cacgctgc 28140 - - tcggcgcgct gatcctcggc gagccgaccg gccggcatcg ctggggcgca gt -#gatcgtcg 28200 - - gcttcctcgg cgtgctgatc gtcgtccagc cgggccggga agccattccg at -#cttcggcg 28260 - - ccttcgtcgg gctgatggcg gcgttgttcg tcgccatcgt cgcgatcacg ct -#gcggcaga 28320 - - tcacccgcac cgaaagcgcc ggcaccaccg tcttctggtt ctcgctgctc tc -#ggtgcccg 28380 - - tgctcggcgc catctacgcg ttcaacttcc gtccgcacga tgccgagacc tg -#ggcgatcc 28440 - - tcatcgccac aggactggtg ggcggcgtcg gccagctggc gctgaccggt gc -#gatgcgct 28500 - - tcgcccccgt ctcggcggtg gtaccgatgg actattcggg gctgatctgg gc -#gacgctct 28560 - - acggctggct gctgttcgac gtgttcccga ccttctcgac ctggctcggt gc -#gccggtga 28620 - - tcatcgccag cgggctctac atcgtctatc gcgagcagaa gctggcccgc gg -#ccaggcta 28680 - - gctacgccga aacgccacta tgaggttgtt ggcgggcatc gccacccgcc ga -#tcgaacac 28740 - - caggccttgc gcccccgccg ccgcgatcac ctcgtccagc aagcgcagcc cc -#caggcagg 28800 - - atcc - # - # - # 28804__________________________________________________________________________

A recombinant bacteria for the production of exopolysaccharides is disclosed as well as a method for making the recombinant bacteria and making an exopolysaccharide from the bacteria by submerged aerobic fermentation of the bacteria utilizing a sugar substrate. In addition, the present invention provides a method of producing bacterial exopolysaccharides by fermentation from sugar substrates that the wild-type bacteria for producing the exopolysaccharide cannot utilize.

BACKGROUND OF THE INVENTION This is a divisional application of application Ser. No. 09/986,299, filed Nov. 8, 2001 now U.S. Pat. No. 7,133,550. The present invention relates to a method and apparatus for fabricating substrates having circuit patterns, such as semiconductor devices and liquid crystal display devices, and, more particularly, to a technique for inspecting substrate patterns in a fabrication process. Conventional optical or electron-beam pattern inspection apparatuses have been proposed in JP-A Nos. H5(1993)-258703, H11(1999)-160247, S61(1986)-278706, H7(1995)-5116, H2(1990)-146682, H9(1997)-312318, and H3 (1991)-85742, for example. FIG. 1 shows an example of an electron-beam pattern inspection apparatus of the type disclosed in JP-A No. H5(1993)-258703. In this conventional electron-beam pattern inspection apparatus, an electron beam 2 emitted from an electron source 1 is deflected in the X direction by a deflector 3 , and the electron beam 2 thus deflected impinges on an object substrate 5 under test after passing through an objective lens 4 . Simultaneously, while a stage 6 is moved continuously in the Y direction, secondary electrons 7 or the like produced from the object substrate 5 are detected by a detector 8 . Thus, a detected analog signal is output from the detector 8 . Then, through an A/D converter 9 , the detected analog signal is converted into a digital image. In an image processor circuit 10 , the digital image thus produced is compared with a reference digital image which is expected to be identical thereto. If any difference is found, the difference is judged to be a pattern defect 11 , and the location thereof is determined. FIG. 2 shows an example of an optical pattern inspection apparatus of the type in JP-A No. H11 (1999)-160247. In this conventional optical inspection apparatus, a light beam emitted from a light source 21 is applied to an object substrate 5 under test through an objective lens 22 , and light reflected from the object substrate 5 is detected by an image sensor 23 . While a stage 6 is moved at a constant speed, detection of reflected light is repeated to produce a detected image 24 . The detected image 24 thus produced is stored into a memory 25 . In an image processing circuit 10 , the detected image 24 is compared with a previously memorized reference image 27 , which is expected to have a pattern identical to that of the detected image 24 . If the pattern of the detected image is identical to that of the reference image 27 , it is judged that there is no defect, on the object substrate 5 . If these patterns are not identical to each other, a pattern defect 11 is recognized, and the location thereof is determined. As an example, FIG. 3 shows a layout of a wafer 31 corresponding to the object substrate 5 . On the wafer 31 , there are formed dies 32 which are to be separated eventually as individual identical products. The stage 6 is moved along a scanning line 33 to detect images in a stripe region 34 . In a situation where a detection position A 35 is currently taken, a pattern image attained at the detection position A 35 is compared with a pattern image attained at a detection position B 36 (reference pattern image 27 ), which has been stored in the memory 25 . Thus, each pattern image is compared with a reference pattern image which is expected to be identical thereto. In this arrangement, the memory 25 has a storage capacity sufficient for retaining reference pattern image data to be used for comparison, and the circuit structure of the memory 25 is designed to perform a circular-shift memory operation. In the following two examples, a defect check is conducted using a binary image of an object under test. In synchronization with pattern detection, a judgment is formed on whether a pattern of the object is defective or not while ignoring a possible defect in a particular mask region. In JP-A No. S61(1986)-278706, there is disclosed an example of a technique for inspecting through-holes on a printed circuit board. In this inspection technique, a printed circuit board having through-holes only in a non-inspection region thereof is prepared beforehand, and an image of the printed circuit board is taken prior to inspection. A binary image indicating the presence/absence of through-holes is thus attained for masking, and it is stored as image data in a masking data storage. At the time of inspection, if a difference found in binary image comparison is located at a position included in a mask region stored in the masking data storage, the difference is ignored for non-inspection. In JP-A No. H7(1995)-5116, there is disclosed an example of a technique for printed circuit board inspection. In this inspection technique, a pattern is detected to provide binary image data, and using the binary image data, a judgment is formed on whether the detected pattern is normal or not; more specifically, it is checked to determine whether the detected pattern meets any specified regular pattern or not. If not, the detected pattern is judged to be defective. In the following two examples, using pattern data, a dead zone is provided for the purpose of allowing an error at a pattern boundary in inspection. In JP-A No. H2(1990)-146682, there is disclosed an example of an inspection technique in which a mask pattern is compared with design data. Through calculation of design data, a pattern is reduced by a predetermined width to attain a reduced image, and also the pattern, is enlarged by a predetermined width to attain an enlarged image. Then, a part common to the reduced image and the enlarged image is extracted to provide a dead zone having a certain width. Thus, using the design data, a mask region is provided so that an error at a pattern boundary having a certain width will be ignored during inspection. In JP-A No. H9(1997)-312318, there is disclosed an example of a technique for inspecting patterns using a scanning electron microscope (hereinafter referred to just as a “SEM”). Using a reference image acquired in advance, a vicinal area of a pattern edge is set up as a region where no critical defect occurs, since a minuscule deviation of a pattern edge is not regarded as a defect. Thus, an image of the region where no critical defect occurs is ignored. If any difference is found between the reference image and an image of a pattern under test, excluding the region where no critical defect occurs, the difference is judged to be a pattern defect. In JP-A. No. H3(1991)-85742, there is disclosed an example of a system for carrying out comparative inspection of printed circuit patterns. An image of a candidate defect attained in comparative inspection, is stored in memory. Then, not simultaneously with the comparative inspection, the memorized image is examined to judge whether a difference is actually a defect or not. On an object under test, there is an area where a considerable difference is found in comparative inspection of patterns, even if the difference is not actually a defect. For example, on an ion-implanted region for formation of a transistor, a non-defective difference may be found in comparative inspection of patterns. Although a difference between a part where ions have been implanted and a part where ions have not been implanted is important at a location of a transistor element, the characteristics of wiring areas, other than transistor element locations, are not affected by the presence/absence of implanted ions. Therefore, in an ion implantation process, rough masking is used to determine where ions are to be implanted. However, in electron-beam inspection of wiring areas, a considerable difference attributable to whether implanted ions are present or not may be detected, resulting in a wrong judgment indicating that the difference represents a defect. Further, for example, in a power line layer where redundant wiring is provided, even if a part of the wiring is not connected, circuit normality can be ensured by providing a connection at another point. Therefore, in some cases, rough patterning is provided for a power wiring arrangement, so that no-connection on pattern elements are left. In comparative inspection of detected images, a difference attributable to whether a connection is provided or not nay be found, resulting in a wrong judgment indicating that the difference represents a defect. Still further, for example, on a pattern edge, a detected signal level varies depending on the thickness/inclination of a film thereof. Although up to a certain degree of variation in detected signal output may be ignored, a considerable difference in detected signal output is likely to be taken as a defect mistakenly. A degree of false defect detection is however applicable as an index representing product quality. It is desirable to examine the degree of false defect detection and preclude false defects before carrying out defect inspection. In the conventional optical/electron-beam pattern inspection apparatuses disclosed in JP-A Nos. H5(1993)-258703 and H11 (1999)-160247, it is not allowed to set up a non-inspection region. In the inspection techniques disclosed in JP-A Nos. S61 (1986)-278706 and H7 (1995)-5116, there is provided a non-inspection region. However, according to an example presented in JP-A No. S61(1986)-278706, it is required to specify a non-inspection region covering a very large area by using a bit pattern. In application to wafer inspection, a wafer surface area 300 mm in diameter has to be inspected using pixels each having a size of 0.1 μm. This requires an impractically large number of pixels, i.e., seven tera-pixels (seven terabits). According to the inspection technique disclosed in JP-A No. H7 (1995)-5116, any areas other than regular pattern areas are treated as non-inspection regions. Since very complex patterns are formed on a wafer, a non-inspection region cannot be set up just by means of simple pattern regularity. In the inspection techniques disclosed in JP-A Nos. H2 (1990)-146682 and H9 (1997)-312318, the use of a non-inspection region is limited to a pattern edge, and therefore it is not allowed to set up a non-inspection region at an arbitrary desired location. In the inspection system disclosed in JP-A No. H3 (1991)-85742, image data of a candidate defect is stored, and then detail inspection is carried out using the stored image data to check whether a difference is actually a defect or not. This approach is applicable to inspection of complex pattern geometries. However, based on predetermined criteria, a judgment is formed on whether a difference is actually a defect or not. Any part may be judged to be normal if requirements based on predetermined criteria are satisfied. That is to say, once a part is judged to be normal, data regarding the part will be lost. As described above, in the conventional pattern inspection techniques, it is not allowed for a user to set up a non-inspection region effective for a device having a complex, large pattern area to be inspected, such as a wafer. Further, in cases where a considerable difference is found in comparative inspection of detected images even if the difference is not actually a defect, it is likely to be misjudged that the difference represents a defect. In addition to these disadvantages, the conventional pattern inspection techniques are also unsatisfactory as regards stability in detection of minuscule defects. SUMMARY OF THE INVENTION It is therefore an object of the present invention to overcome the above-mentioned disadvantages of the prior art by providing a pattern inspection method and apparatus for enabling a user to easily set up a non-inspection region effective for a device having a complex, large pattern area to be inspected. In accomplishing this object of the present invention, and according to one aspect thereof, there is provided a pattern inspection apparatus such as shown in FIG. 4 . While an exemplary configuration of an electron-beam pattern inspection apparatus is presented here, an optical pattern inspection apparatus can be configured in the same fashion in principle. The electron-beam pattern inspection apparatus shown in FIG. 4 comprises an electron source 1 for emitting an electron beam 2 , a deflector 3 for deflecting the electron beam 2 , an objective lens 4 for converging the electron beam 2 onto an object substrate 5 under test, a stage 6 for holding the object substrate 5 and for scanning/positioning the object substrate 5 , and a detector 8 for detecting secondary electrons 7 or the like produced from the object substrate 5 to output a detected analog signal. An A/D converter 9 converts the detected analog signal into a digital image, and an image processor circuit 10 compares the converted digital image with a reference digital image expected to be identical thereto and identifies a difference found in comparison as a candidate defect 40 . A candidate defect memory part 41 is provided for storing feature quantity data of each candidate defect 40 , such as coordinate data, projection length data and shape data, and a mask setting part 44 examines pattern defects 11 stored in the candidate defect memory part 41 and flags a candidate defect located in a mask region 42 (shown in FIG. 5 ), prespecified with coordinates, as a masked defect 43 (shown in FIG. 5 ). An operation display 45 is provided on which data of pattern defects 11 received from the mask setting part 44 is displayed, an image of a selected pattern defect 11 is displayed, and the mask region 42 is displayed or edited. The operations in the electron-beam pattern inspection apparatus, configured as mentioned above, will be described. Referring now to FIG. 5 , the mask region 42 will be described first. On the object, substrate 5 , there is an area where a considerable difference is found in comparative inspection of patterns, even if the difference is not actually a defect, such as a region 50 where ions have been implanted. In actual practice, during ion implantation, ions are likely to be implanted in a deviated fashion, i.e., a deviated ion-implanted part 52 is formed in addition to normal ion-implanted pattern parts 51 . The deviated ion-implanted part 52 has no adverse effect on device characteristics, i.e., the deviated ion-implanted pan 52 should be judged to be non-defective. However, the deviated ion-implanted part 52 is detected as a pattern defect 11 . Therefore, an area including the ion-implanted region 50 is set up as a mask region 42 , and a possible defect in the mask region 42 is treated as a masked defect 43 . Since the same die pattern is formed repetitively on the wafer 31 shown in FIG. 3 , on-die coordinates are used in region recognition. Parts, having the sane coordinates on different dies are regarded as identical, and if in-die coordinates of a part are included in a specified region, it is regarded that the part is included in the specified region. For the wafer 31 , beam shots are also characterized by repetitiveness besides dies. Each shot is a unit of beam exposure in a pattern exposure system used for semiconductor device fabrication. For identifying some kinds of false defects to be precluded in pattern inspection, the use of shots may be more suitable than that of dies with respect to pattern repetitiveness. Although the following description handles dies, it will be obvious to those skilled in the art that shots are applicable in lieu of dies and that an arrangement may be provided for allowing a changeover between shots and dies. Operations in the electron-beam pattern inspection apparatus according to the present invention include a conditioning operation in which the mask region 42 is defined and an inspection operation in which any candidate defect 40 detected in other than the mask region 42 is judged to be a pattern defect. In the conditioning operation, the mask region 42 is cleared, the electron beam 2 emitted from the electron source 1 is deflected in the X direction by the deflector 3 , and the electron beam 2 thus deflected is applied to the object substrate 5 through the objective lens 4 . Simultaneously, while the stage 6 is moved continuously in the Y direction, secondary electrons 7 or the like produced from the object substrate 5 are detected by the detector 8 . Thus, a detected analog signal is output from the detector 8 . Then, through the A/D converter 9 , the detected analog signal is converted into a digital image. In the image processor circuit 10 , the digital image thus produced is compared with a reference digital image which is expected to be identical thereto. If any difference is found in comparison, the difference is indicated as a candidate defect 40 . Feature quantity data of each candidate defect 40 , such as coordinate data, projection length data and shape data (image data), is stored into the candidate defect memory part 41 . In the mask setting part 44 , pattern defects 11 are set using feature quantity data of respective candidate defects 40 . The pattern defects 11 are superimposed on an image of the object substrate 5 , and the resultant image is presented on a map display part 55 of an operation display 45 (screen), as shown in FIG. 6 . The user can select any one of the pattern defects 11 (including true defects 57 and, false defects 58 not to be detected, in FIG. 6 ) on the map display part 55 of the operation display 45 . An image of a pattern defect 11 selected on the map display part 55 is presented on an image display part 56 of the operation display 45 . By checking the image of each of the pattern defects 11 on the image display part 56 , the user classifies the pattern defects 11 into true defects 57 and false defects 58 not to be detected. The results of this classification are indicated as particular symbols on the map display part 55 . After completion of the defect classification mentioned above, the user selects an operation display screen shown in FIG. 7 , which comprises a map display part 55 for presenting an enlarged map including true defects 57 , false defects 58 not to be detected and a current position indicator 59 , and an image display part 56 for presenting an image corresponding to the current position indicator 59 . On the map display part 55 , the user can specify a mask region 42 and check a position of each pattern defect 11 . With reference to classification information on each pattern defect 11 and the image corresponding to the current position indicator 59 , the user sets up coordinates of a mask region 42 so that the false defects 58 will not be detected. As required, the user carries out the conditioning operation again to set up the coordinates of the mask region 42 more accurately. In the inspection operation, the electron beam 2 emitted from the electron source 1 is deflected in the X direction by the deflector 3 , and the electron beam 2 thus deflected is applied to the object substrate 5 through the objective lens 4 . Simultaneously, while the stage 6 is moved continuously in the Y direction, secondary electrons 7 or the like produced from the object substrate 5 are detected by the detector 8 . Thus, a detected analog signal is output from the detector 8 . Then, through the A/D converter 9 , the detected analog signal is converted into a digital image. In the image processor circuit 10 , the digital image thus produced is compared with a reference digital image which is expected to be identical thereto. If any difference is found in comparison, the difference is indicated as a candidate defect 40 . Feature quantity data of each candidate defect 40 , such as coordinate data, projection length data and shape data (image data), is stored into the candidate defect memory part 41 . The feature quantity data of each candidate defect 40 is examined to judge whether the candidate defect 40 is located in the specified mask region 42 or not. If it is determined that the candidate defect 40 is not located in the specified mask region 42 , the candidate defect 40 is defined as a pattern defect 11 . Then, the pattern defect 11 is superimposed on an image of the object substrate 5 , and the resultant image is presented on the map display part 55 . Even if the candidate defect 40 is not defined as a pattern defect 11 , the feature quantity data thereof is retained so that it can be displayed again. This makes it possible for the user to avoid forming a wrong judgment that a considerable non-defective difference is a defect. In the above-mentioned arrangement of the present invention, the mask setting part 44 is used for determining a false defect not to be detected. While coordinates are used in the mask setting part 44 as exemplified above, any other pattern data or feature quantity data of each candidate defect image is also applicable for identification. On a pattern edge, a degree of variation in detected signal out put dues not depend on, coordinates, and therefore pattern-edge feature quantity data is used for identification instead of coordinate data. Further, while masking is made for non-inspection of candidate defects, as exemplified above, another inspection means, or a method of inspection based on another criterion is also applicable to examination of an area corresponding to a mask region. In this case, according to conditions specified by the user after inspection, a defect judgment can be formed again regarding candidate defects 40 stored in the candidate defect memory part 41 . As described above, and according to the present invention, the user can set up a non-inspection region which is effective for a device having a complex, large pattern area to be inspected, such as a wafer. Further, in cases where a considerable difference is found in comparative inspection of detected images, even if the difference is not actually a defect, the present invention makes it possible to avoid false defect detection while carrying out detection of minuscule defects. These and other objects, features and advantages of the invention will be apparent from the following mere particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a conventional electron-beam pattern inspection apparatus; FIG. 2 is a schematic diagram of a conventional optical pattern inspection apparatus; FIG. 3 is a plan view showing a layout of a wafer; FIG. 4 is a schematic diagram of an electron-beam pattern inspection apparatus, showing an arrangement of first problem-solving means according to the present invention; FIG. 5 is a diagrammatic plan view illustrating operation of the first problem-solving means according to the present invention; FIG. 6 is a diagram showing the layout of a defect check screen; FIG. 7 is a diagram showing the layout of a mask region setting screen; FIG. 8 is a schematic diagram showing the configuration of an electron-beam pattern inspection apparatus in a first preferred embodiment of the present invention; FIG. 9 is a diagram showing a startup screen in the first preferred embodiment of the present invention; FIG. 10 is a diagram showing a contrast adjustment screen for recipe creation in the first preferred embodiment of the present invention; FIG. 11 is a diagram showing a trial inspection initial screen for recipe creation in the first preferred embodiment of the present invention; FIG. 12 is a plan view of a wafer, showing a scanning sequence in the first preferred embodiment of the present invention; FIG. 13 is a diagram showing a trial inspection defect check screen for recipe creation in the first preferred embodiment of the present invention; FIG. 14 is a diagram showing a mask region setting screen for recipe creation in the first preferred embodiment of the present invention; FIG. 15 is a diagram showing an inspection defect check screen in the first preferred embodiment of the present invention; FIG. 16 is a schematic diagram showing the configuration of an electron-beam pattern inspection apparatus in a second preferred embodiment of the present invention; FIG. 17 is a diagram showing an image processing region setting screen for recipe creation in the second preferred embodiment of the present invention; FIG. 18 is a schematic diagram showing the configuration of an electron-beam pattern inspection apparatus in a third preferred embodiment of the present invention; FIG. 19 is a diagram showing a defect check screen for recipe creation in the third preferred embodiment of the present invention; and FIG. 20 is a diagram showing an image processing feature quantity data setup screen for recipe creation in the third preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail by way of example with reference to the accompanying drawings. Embodiment 1 A first preferred embodiment of the present invention will be described. FIG. 8 shows the configuration of an electron-beam pattern inspection apparatus according to the first preferred embodiment of the present invention. The electron-beam pattern inspection apparatus comprises an electron optical system 106 , including: an electron source 1 for emitting an electron beam 2 from an electron gun in which the electron beam 2 from the electron source 1 is extracted and accelerated by an electrode to produce a virtual electron source at a predetermined point through an electrostatic or magnetic field superimposing lens; a condenser lens 60 for converging the electron beam 2 from the virtual electron source at a predetermined convergence point; a blanking plate 63 which is equipped in the vicinity of the convergence point of the electron beam 2 for turning on/off the electron beam 2 ; a deflector 105 for deflecting the electron beam 2 in the X and Y directions; and an objective lens 4 for converging the electron beam 2 onto an object substrate (wafer 31 ). Further, the electron-beam pattern inspection apparatus comprises a specimen chamber 107 in which the object substrate (wafer 31 ) is held in a vacuum; a stage 6 where the wafer 31 is mounted and to which a retarding voltage 108 is applied for enabling detection of an image at an arbitrary position; and a detector 8 for detecting secondary electrons 7 or the like produced from the object substrate to output a detected analog signal. An A/D converter 9 is provided for converting the detected analog signal into a digital image, which is stored in a memory 109 for storing digital image data, and an image processor circuit 10 compares the converted digital image with a reference digital image stored in the memory 109 and identifies a difference found in comparison as a candidate defect 40 . A candidate defect memory part 41 , which stores feature quantity data of each candidate defect 40 , such as coordinate data, projection length data and shape data, is provided in a general control part 110 , in which the overall apparatus control is conducted, with feature quantity data of each pattern defect 11 being received from the candidate defect memory part 41 . A mask region 42 (shown in FIG. 5 ) is set as region data, and a candidate defect located in the mask region 42 is flagged as a masked defect 43 (shown. in FIG. 5 ) (control lines from the general control part 110 are not shown in FIG. 8 ). An operation display 45 is provided on which data of pattern defects 11 is displayed, an image of a selected pattern defect 11 is displayed, and the mask region 42 is displayed or edited. Still further, the electron-beam pattern inspection apparatus comprises a keyboard, a mouse and a knob (not shown) for operation and control; a Z sensor for measuring the height level of each wafer 31 to maintain a focal point of a detected digital image through control of a current applied to the objective lens by adding an offset 112 ; a loader (not shown) for loading the wafer 31 from its cassette 114 to the specimen chamber 107 and for unloading the wafer 31 from the specimen chamber 107 to the cassette 114 ; an orientation flat detector (not shown) for positioning the wafer 31 according to the circumferential shape of the wafer 31 ; an optical microscope 118 for allowing observation of a pattern on the wafer 31 ; and a standard specimen 119 , which is set on the stage 6 . Operations in the first preferred embodiment include a conditioning operation, in which a mask region 42 is set up, and an inspection operation, in which any candidate defect 40 detected in other than the mask region 42 is examined as a pattern defect. In the conditioning operation, a user opens a startup screen shown in FIG. 9 on the operation display 45 . On a slot selection part 130 of the startup screen, the user selects a code number of a slot where the wafer 31 to be inspected is contained. Then, on a recipe selection part 131 , the user specifies a product type of the wafer 31 and a process step thereof, and the user presses a recipe creation start button 132 for starting the conditioning operation. The conditioning operation includes contrast setting for the electron optical system, pattern layout setting for the wafer 31 , pattern positioning alignment for the wafer 31 , calibration in which a signal level of the wafer 31 is checked at a position where the signal level is indicated accurately, inspection condition setting, mask region setting, and a setup condition check in trial inspection. The contrast setting, mask region setting, and trial inspection, which form essential parts of the present invention, will be described. The general control part 110 provides operational instructions to each part in the following manner. First, the general control part 110 issues an operational instruction to the loader (not shown) so that the loader takes the wafer 31 out of the cassette 114 . Then, through the use of the orientation flat detector (not shown), the circumferential shape of the wafer 31 is checked, and the wafer 31 is positioned according to the result of this check. The wafer 31 is then mounted on the stage 6 , and the specimen chamber 107 is evacuated. Simultaneously, the electron optical system and the retarding voltage 108 are conditioned. A voltage is applied to the blanking plate 63 to turn off the electron beam 2 . The stage 6 is moved so that the standard specimen 119 can be imaged, and an output of the Z sensor 113 is made effective. While a focal point of the electron beam 2 from the electron optical system is maintained at a position corresponding to “a value detected by the Z sensor 113 +an offset 112 ”, raster scanning is performed by the deflector 105 . In synchronization with this raster scanning, the voltage applied to the blanking plate 63 is turned off so that the wafer 31 is irradiated with the electron beam 2 as required. Backscattered electrons or secondary electrons produced from the wafer 31 are detected by the detector 8 , which then outputs a detected analog signal. Through the A/D converter 9 , the detected analog signal is converted into a digital image. By changing the offset 112 , a plurality of digital images are detected, and in the general control part 110 , an optimum offset for maximizing the sun of image differential values is determined. The optimum offset thus determined is set up as the current offset value. After the optimum off set is established, the output of the Z sensor 113 is made ineffective, and a screen transition is made to the contrast adjustment screen shown in FIG. 10 . The contrast adjustment screen comprises: a map display part 55 having a map display area, a button for controlling display of the entire wafer or die map, and a mouse operation command button 140 for controlling position movement or item selection by the use of the mouse (not shown); an image display part 56 , having an image display area and an image changeover button 141 for setting an image magnification, for selecting an optical micrograph image attained through the optical microscope 118 or a SEM image attained through the electron optical system, and for specifying a kind of image; a recipe creation item selection button 142 ; a recipe creation end button 133 ; and a recipe save button 134 . On the contrast adjustment screen, the user sets the mouse operation command button 140 to a movement mode, and performs movement on the map by clicking the mouse to view an image at the current position on the image display part. Then, the user assigns an adjustment item of the electron optical system to the knob, and adjusts each part of the electron optical system to attain proper contrast. The recipe creation end button 133 is used for terminating recipe creation; the recipe save button 134 is used for saving recipe condition data; and the recipe creation item selection button 142 is used for setting another condition and issuing an instruction for screen transition. These buttons are available on all of the screens. To open a trial inspection initial screen, as shown in FIG. 11 , the user sets the recipe creation item selection button 142 to a trial inspection item. The trial inspection initial screen comprises a map display part 55 , a recipe creation end button 133 , a recipe save button 134 , a recipe creation item selection button 142 , an inspection start button 143 , and an inspection end bit ton 144 . The user sets the mouse operation command button 140 to a selection mode. Then, by clicking a die on the map display part 55 , the user can select/deselect the die for trial inspection. Each die can thus be selected for trial inspection. After selecting any die for trial inspection, the user presses the inspection start button 143 to start trial inspection. When trial inspection is started, the stage 6 is driven for movement to a scanning start position of the region to be inspected on the wafer 31 mounted thereon. A pre-measured offset value inherent in the wafer 31 is added to the offset 112 , and the Z sensor 113 is made effective. Then, along the scanning line 33 shown in FIG. 3 , the stage 6 is scanned in the Y direction. In synchronization with this stage scanning, the deflector 105 is scanned in the X direction. During a period of effective scanning, a voltage to the blanking plate 63 is turned off to let the electron beam 2 fall on the wafer 31 for scanning the surface thereof. Backscattered electrons or secondary electrons produced from the wafer 31 are detected by the detector 8 , and through the A/D converter 9 , a digital image of the stripe region 34 is attained. The digital image thus attained is stored into the memory 109 . After completion of the scanning operation of the stage 6 , the Z sensor 113 is made ineffective. The entire region of interest can be inspected by repeating stage scanning. In cases were the entire surface of the wafer 31 is inspected, the scanning sequence shown in FIG. 12 is adopted. When the detection position A 35 is selected in the image processor circuit 10 , an image attained at the detection position A 35 is compared with an image attained at the detection position B 36 , which has been stored in the memory 109 . If any difference is found in the comparison, the difference is extracted as a candidate defect 40 to prepare a list of pattern defects 11 . The list of pattern defects 11 thus prepared is sent to the general control part 110 . In the general control part 110 , feature quantity data of each pattern defect 11 is taken out of the candidate defect memory part 41 . A pattern defect 11 located in the mask region 42 , which has been registered in a recipe, is flagged as a masked defect 43 (feature quantity data thereof is flagged). After completion of inspection of the entire region of interest, the user opens a trial inspection defect check screen shown in FIG. 13 . The trial inspection defect check screen comprises a defect display editing part 150 for displaying feature quantity data of defects and editing classification thereof, a map display part 55 in which a current position indicator 59 indicating the current position and class code symbols of pattern defects 11 are displayed on a layout of the wafer 31 , an image display part 56 in which an image taken at the current position is displayed, a display changeover button 151 for turning on/off masked defects 43 , and other buttons which have already been described. The user sets the mouse operation command button 140 to the selection mode, and then clicks any pattern defect 11 indicated on the nap display part 55 . Thus, an image of the pattern defect 11 is presented on the image display part 56 , and feature quantity data thereof is presented on the defect display editing part 150 . On the defect display editing part 150 , the pattern defect 11 is subjected to classification according to the image and feature quantity data thereof, i.e., a class code is assigned to the feature quantity data of the pattern defect 11 . At this step, if it is desired to treat the pattern defect 11 as a masked defect, a particular class code is assigned thereto. Thus, it can be identified as a masked defect on the map display part 55 . After completion of the defect classification, the user makes a transition to a mask region setting screen, as shown in FIG. 14 , by using the recipe creation item selection button, or the user returns to the trial inspection initial screen by pressing the inspection end button. The mask region setting screen comprises a map display part 55 in which a current position indicator 59 indicating the current position, class code symbols of pattern, defects 11 and a mask region 42 are displayed on a layout of the wafer 31 ; an image display part 56 in which an image taken at the current position is displayed; a display changeover button 151 for turning on/off masked defects 43 , a new region button 160 for creating a new mask region; a completion button 161 for indicating the end of creation of a new mask region; and other buttons which have already described. Note that the map display part 55 presents the entire die region. The current position indicator 59 and pattern defects 11 in the entire die region are indicated in representation of on-die coordinates. The user sets the mouse operation command button 140 to the movement mode, and then clicks in the vicinity of a class code of any defect to be masked for making movement thereto. Thus, an image of the defect to be masked is presented on the image display part 56 . If the user judges that a mask region should be formed, the user presses the new creation button 160 to select a region creation mode. In this mode, the user defines a mask region by clicking at the upper left corner and the lower right corner thereof on the image display part. The mask region thus defined (mask region 42 ) is indicated on the map display part 55 . After creating the mask region, as mentioned above, the user can turn on/off masked defects 43 by pressing the display changeover button 151 to confirm the location of the defect to be masked. When the mask region 42 is set tp as required, the user presses the recipe save button 134 for saving data of the mask region 42 in a recipe. After saving the data of the mask region 42 , the user presses the completion button 161 to return to the trial inspection defect check screen. Further, on the trial inspection defect check screen, the user presses the inspection end button 144 to return to the trial inspection initial screen. Then, it is also possible for the user to select another die for trial inspection. For confirming and terminating the above-mentioned recipe creation session, the user presses the recipe creation end button 133 . Upon completion of the recipe creation, the wafer 31 is unloaded back to the cassette 114 . The following description is directed to the inspection operation in which any candidate defect detected in other than the mask region is examined as a pattern defect. In the inspection operation, the user opens the startup screen shown in FIG. 9 on the operation display 45 . On the slot selection part 130 of the start tp screen, the user selects a code number of a slot were the wafer 31 to be inspected is contained. Then, on the recipe selection part 131 , the user specifies a product type of the wafer 31 and a process step thereof, and the user presses the inspection start button 330 for starting the inspection operation. After wafer loading, alignment and calibration are performed, inspection processing is carried out. Then, defect check and defect data output are performed, and wafer unloading is carried out at the end of inspection. The inspection processing and defect check, which form essential parts of the present invention, will now be described. When the user presses the inspection start button 330 to indicate the start of inspection, the stage 6 is driven for movement to a scanning start position of the region to be inspected on the wafer 31 mounted thereon. A pre-measured offset value inherent in the wafer 31 is added to the offset 112 , and the Z sensor 113 is made effective. Then, along the scanning line 33 shown in FIG. 3 , the stage 6 is scanned in the Y direction. In synchronization with this stage scanning, the deflector 105 is scanned in the X direction. During a period of effective scanning, a voltage to the blanking plate 63 is turned off to let the electron beam 2 fall on the wafer 31 for scanning the surface thereof. Backscattered electrons or secondary electrons produced from the wafer 31 are detected by the detector 8 , and through the A/D converter 9 , a digital image of the stripe region 34 is attained. The digital image thus attained is stored into the memory 109 . After completion of the scanning operation of the stage 6 , the Z sensor 113 is made ineffective. The entire region of interest can be inspected by repeating stage scanning. In cases where the entire surface of the wafer 31 is inspected, the scanning sequence shown in FIG. 12 is adopted. When the detection position A 35 is selected in the image processor circuit 10 , an image attained at the detection position A 35 is compared with an image attained at the detection position B 36 , which has been stored in the memory 109 . If any difference is formed in comparison, the difference is extracted as a candidate defect 40 to prepare a list of pattern defects 11 . The list of pattern defects 11 thus prepared is sent to the general control part 110 . In the general control part 110 , feature quantity data of each pattern defect 11 is taken out of the candidate defect memory part 41 . A pattern defect 11 located in the mask region 42 , which has been registered in a recipe, is flagged as a masked defect 43 (feature quantity data thereof is flagged). After completion of inspection of the entire region of interest, the inspection defect check screen shown in FIG. 15 is opened. The inspection defect check screen comprises a defect display editing part 150 for displaying feature quantity data of defects and editing classification thereof, a map display part 55 in which a current position indicator 59 indicating the current position and class code symbols of pattern defects 11 are displayed on a layout of the wafer 31 , an image display part 56 in which an image taken at the current position is displayed, a display changeover button 151 for turning on/off masked defects 43 , and an inspection end button 144 for indicating the end of inspection. The user sets the mouse operation command button 140 to the selection mode, and then clicks any pattern defect 11 indicated on the map display part 55 . Thus, an image of the pattern defect 11 is presented on the image display part 56 , and feature quantity data thereof is presented on the defect display editing part 150 . On the defect display editing part 150 , the pattern defect 11 is subjected to classification according to the image and feature quantity data thereof, i.e., a class code is assigned to the feature quantity data of the pattern defect 11 . Using the display changeover button 151 , the user can turn on/off masked defects 43 to check for any pattern defect in the mask region 41 . To terminate the inspection defect check session mentioned above, the user presses the inspection end button 144 . Each classified pattern defect 11 and feature quantity data thereof are stored into memory means (not shown) in the general control part 110 , and also delivered to external memory means (not shown) through a communication line (not shown) or to other inspection/observation means (not shown). Then, control is returned to the initial screen. According to one aspect of the first preferred embodiment, the entire surface of each wafer can be inspected using a SEM image thereof without regard to pattern defects in the mask region 42 , i.e., true pattern defects 57 alone can be indicated to the user for easy identification thereof. Further, according to another aspect of the first preferred embodiment, it is also possible to display masked defects in the mask region 42 . Therefore, in cases where rough patterning is used to form a redundant power wiring layer, the degree of roughness in patterning can be examined by turning on/off the masked defects. Still further, according to another aspect of the first preferred embodiment, the mask region 42 can be set so as to mask false defects which have been identified under actual inspection conditions. It is therefore possible for the user to define proper masking. Furthermore, according to another aspect of the first preferred embodiment, a different mask region 42 can be created additionally. Therefore, in cases where masking has been defined using an object containing a small degree of random variation, the user can set up a new mask region additionally for providing proper masking as required. In a first modified form of the first preferred embodiment, mask region management may be implemented in a part of image processing function hardware, instead of using the general control part that is a computer system. In this modified arrangement, essentially the same functionality is provided. Since the number of detectable defects is limited in terms of output capacity, this limitation can be removed by using image processing function hardware for mask region management. In a second modified form of the first preferred embodiment, plural kinds of mask regions may be set up while only one kind of mask region has been treated in the forgoing description. In this modified arrangement, false defects due to plural kinds of causes can be classified for defect data management. By turning on/off indications of false defects according to each kind of cause, the user can check the conditions thereof. Thus, it is possible for the user to preclude only minimum false defects for carrying out proper inspection. In a third modified form of the first preferred embodiment, a mask region on the mask region setting screen may be automatically defined as a rectangular region having a size approximately two times as large as the projection length of any false defect not to be detected. By merging neighboring mask regions, a mask region is determined using data of pattern defects classified without intervention of the user. In this modified arrangement, a flask region can be generated precisely through automatic operation. For example, masking at hundreds of points can be provided automatically so as to allow for easy identification. As a further modified form of this modification, there may be provided an arrangement in which an automatically determined mask region can be redefined or edited. In a fourth modified form of the first preferred embodiment, a mask region may be determined using design data in inspection of rough patterning for power wiring, ion implantation, or the like. In this modified arrangement, the user can set up a mask region for each kind of false defect while saving the time of input. In a fifth modified form of the first preferred embodiment, pattern defects are indicated on layout information at a networked CAD display terminal instead of being indicated on layout information stored in the inspection apparatus. In this modified arrangement, possible defects on each layer in rough patterning and fine patterning can be identified with ease. Embodiment 2 A second preferred embodiment of the present invention will be described. FIG. 16 shows an example of the configuration of an electron-beam pattern inspection apparatus according to the second preferred embodiment of the present invention. The electron-beam pattern inspection apparatus comprises an electron optical system including: an electron source 1 , for emitting an electron beam 2 from an electron gun in which the electron beam 2 from the electron source 1 is extracted and accelerated by an electrode to produce a virtual electron source at a predetermined point through an electrostatic or magnetic field superimposing lens; a condenser lens 60 for converging the electron beam 2 from the virtual electron source at a predetermined convergence point; a blanking plate 63 which is equipped in the vicinity of the convergence point of the electron beam 2 for turning on/off the electron beam 2 ; a deflector 105 for deflecting the electron beam 2 in the X and Y directions; and an objective lens 4 for converging the electron beam 2 onto an object substrate. Further, the electron-beam pattern inspection apparatus comprises a specimen chamber 107 in which the object substrate (wafer 31 ) is held in a vacuum; a stage 6 where the wafer 31 is mounted and to which a retarding voltage 108 is applied for enabling detection of an image at an arbitrary position; and a detector 8 for detecting secondary electrons 7 or the like produced from the object substrate to output a detected analog signal. An A/D converter 9 is provided for converting the detected analog signal into a digital image, which is stored in a memory 109 for storing digital image data, and an image processor circuit 202 compares the converted digital image with a reference digital image stored in the memory 109 and identifies a difference, found in the comparison by changing an image processing condition 201 for each image processing region 200 , as a pattern defect 11 . A general control part 110 is provided, in which feature quantity data of each pattern defect 11 , such as coordinate data, projection length data and shape data, is handled (control lines from the general control part 110 are not shown in FIG. 16 ); and an operation display 45 is provided on which data of pattern defects 11 is displayed, an image of a selected pattern defect 11 is displayed, and each image processing region 200 is displayed or edited. Still further, the electron-beam pattern inspection apparatus comprises a keyboard, a mouse and a knob (not shown) for operation and control; a Z sensor 113 for measuring the height level of each wafer 31 to maintain a focal point of a detected digital image through control of a current applied to the objective lens by adding an offset 112 ; a loader (not shown) for loading the wafer 31 from its cassette 114 to the specimen chamber 107 and unloading the wafer 31 from the specimen chamber 107 to the cassette 114 ; an orientation flat detector (not shown) for positioning the wafer 31 according to the circumferential shape of the wafer 31 ; an optical microscope 118 for allowing observation of a pattern on the wafer 31 ; and a standard specimen 119 which is set on the stage 6 . Operations in the second preferred embodiment include a conditioning operation, in which an image processing region 200 and an image processing condition 201 thereof are set up, and an inspection operation, in which pattern defects 11 are detected. In the conditioning operation, the user opens the startup screen shown in FIG. 9 on the operation display 45 . On a slot selection part 130 of the startup screen, the user selects a code number of a slot where the wafer 31 to be inspected is contained. Then, on a recipe selection part 131 , the user specifies a product type of the wafer 31 and a process step thereof, and the user presses a recipe creation start button 132 for starting the conditioning operation. The conditioning operation includes contrast setting for the electron optical system, pattern layout setting for the wafer 31 , pattern positioning alignment for the wafer 31 , calibration in which a signal level of the wafer 31 is checked at a position were the signal level is indicated accurately, inspection condition setting image processing region setting for specifying an image processing region 200 and an image processing condition 201 thereof, and setup condition check in trial inspection. The contrast setting, image processing region setting, and trial inspection, which form essential parts of the present invention, will now be described. The general control part 110 provides operational instructions to each part in the following manner. First, the general control part 110 issues an operational instruction to the loader (not shown) so that the loader takes the wafer 31 out of the cassette 114 . Then, through the use of the orientation flat detector (not shown), the circumferential shape of the wafer 31 is checked, and the wafer 31 is positioned according to the result of this check. The wafer 31 is then mounted on the stage 6 , and the specimen chamber 107 is evacuated. Simultaneously, the electron optical system and the retarding voltage 108 are conditioned. A voltage is applied to the blanking plate 63 to turn off the electron beam 2 . The stage 6 is moved so that the standard specimen 119 can be imaged, and an output of the Z sensor 113 is made effective. While a focal point of the electron beam 2 is maintained at a position corresponding to “a value detected by the Z sensor 113 +an offset 112 ”, raster scanning is performed by the deflector 105 . In synchronization with this raster scanning, the voltage applied to the blanking plate 63 is turned off so that the wafer 31 is irradiated with the electron beam 2 as required. Backscattered, electrons or secondary electrons produced from the wafer 31 are detected by the detector 8 , which then outputs a detected analog signal. Through the A/D converter 9 , the detected analog signal is converted into a digital image. By changing the offset 112 , a plurality of digital images are detected, and in the general control part 110 , an optimum offset for maximizing the sum of image differential values is determined. The optimum offset 111 thus determined is set up as the current offset value. After the optimum offset is established, the output of the Z sensor 113 is made ineffective and a screen transition is made to a contrast adjustment screen, such as shown in FIG. 10 . The contrast adjustment screen comprises: a map display part 55 having a map display area, a button for controlling display of the entire wafer or die map, and a mouse operation command button 140 for controlling position movement or item selection by the use of the mouse 121 (not shown); an image display part 56 having an image display area and an image changeover button 141 for setting an image magnification, selecting an optical micrograph image attained through the optical microscope 118 or a SEM image attained through the electron optical system, and specifying a kind of image; a recipe creation item selection button 142 ; a recipe creation end button 133 ; and a recipe save button 134 . On the contrast adjustment screen, the user sets the mouse operation command button 140 to a movement mode, and performs movement on the map by clicking the mouse to view an image at the current position on the image display part. Then, the user assigns an adjustment item of the electron optical system to the knob, and adjusts each part of the electron optical system to attain proper contrast. The recipe creation end button 133 is used for terminating recipe creation; the recipe save button 134 is used for saving recipe condition data; and the recipe creation item selection button 142 is used for setting another condition and issuing an instruction for screen transition. These buttons are available on all the screens. To open a trial inspection initial screen, such as shown in FIG. 11 , the user sets the recipe creation item selection button 142 to a trial inspection item. The trial inspection initial screen comprises a map display part 55 , a recipe creation end button 133 , a recipe save button 134 , a recipe creation item selection button 142 , an inspection start button 143 , and an inspection end button 144 . The user sets the mouse operation command bitten 140 to a selection mode. Then, by clicking a die on the map display part 55 , the user can select/deselect a die for trial inspection. Each die can thus be selected for trial inspection. After selecting any die for trail inspection, the user presses the inspection start button 143 to start trial inspection. When trial inspection is started, the stage 6 is driven for movement to a scanning start position of the region to be inspected on the wafer 31 mounted thereon. A pre-measured offset value inherent in the wafer 31 is added to the offset 112 , and the Z sensor 113 is made effective. Then, along the scanning line 33 shown in FIG. 3 , the stage 6 is scanned in the Y direction. In synchronization with this stage scanning, the deflector 105 is scanned in the X direction. During a period of effective scanning, a voltage to the blanking plate 63 is turned off to let the electron beam 2 fall on the wafer 31 , for scanning the surface thereof. Backscattered electrons or secondary electrons produced from the wafer 31 are detected by the detector 8 , and through the A/D converter 9 , a digital image of the stripe region 34 is attained. The digital image thus attained is stored into the memory 109 . After completion of the scanning operation of the stage 6 , the Z sensor 113 is made ineffective. The entire region of interest can be inspected by repeating stage scanning. In cases where the entire surface of the wafer 31 is inspected, the scanning sequence shown in FIG. 12 is adopted. When the detection position A 35 is selected in the image processor circuit 202 , an image attained at the detection position A 35 is compared with an image attained at the detection position B 36 , which has been stored in the memory 109 . If any difference is found in comparison, the difference is extracted as a pattern defect 11 to prepare a list of pattern defects 11 . The list of pattern defects 11 thus prepared is sent to the general control part 110 . After completion of inspection of the entire region of interest, the user opens a trial inspection defect check screen, such as shown in FIG. 13 . The trial inspection defect check screen comprises a defect display editing part 150 for displaying feature quantity data of defects and editing classification thereof, a map display part 55 in which a current position indicator 59 indicating the current position and class code symbols of pattern defects 11 are displayed on a layout of the wafer 31 , an image display part 56 in which an image taken at the current position is displayed, a display changeover button 151 for turning on/off masked defects 43 , and other buttons which have already been described. The user sets the mouse operation command button 140 to the selection mode, and then clicks any pattern defect 11 indicated on the map display part 55 . Thus, an image of the pattern defect 11 is presented on the image display part 56 , and feature quantity data thereof is presented on the defect display editing part 150 . On the defect display editing part 150 , the pattern defect 11 is subjected to classification according to the image and feature quantity data thereof, i.e., a class code is assigned to the feature quantity data of the pattern defect 11 . At this step, if it is desired to treat the pattern defect 11 as a masked defect, a particular class code is assigned thereto. Thus, it can be identified as a masked defect on the map display part 55 . After completion of the defect classification, the user makes a transition to an image processing region setting screen shown in FIG. 17 by using the recipe creation item selection button, or the user returns to the trial inspection initial screen by pressing the inspection end button. The image processing region setting screen comprises a map display part 55 in which a current position indicator 59 indicating the current position, class code symbols of pattern defects 11 , and an image processing region 200 are displayed on a layout of the wafer 31 ; an image display part 56 in which an image taken at the current position is displayed; a defect redisplay button 207 for defect indication based on feature quantity image data of each pattern defect 11 ; a new region button 160 for creating a new region; a completion button 161 for indicating the end of creation of a new region, and other buttons which have already described. Note that the map display part 55 presents the entire die region. The current position indicator 59 and pattern defects 11 in the entire die region are indicated in representation of on-die coordinates. The user sets the mouse operation command button 140 to the movement mode, and then clicks in the vicinity of a class code of any defect corresponding to the image processing condition 201 to be changed for making movement thereto. Thus, an image of the defect of interest is presented on the image display part 56 . If the user judges that the image processing condition 201 should be changed, the user presses the new creation button 160 to select a region creation mode. In this mode, the user defines a region by clicking at the upper left corner and the lower right corner thereof on the image display part, and the user provides a correspondence between an image processing condition number 206 of the region and a class code. Reference is made to the feature quantity image data 203 of a pattern defect 11 having the class code which corresponds to the image processing condition number, and the image processing condition 201 is set up for the image processing condition number so that all-defects detection will not be made by the image processor circuit or software in the general control part (computer). As required, the user adjusts the image processing condition 201 manually. Using a special condition on/off button 208 , the user specifies whether or not the image processing condition 201 is to be applied at the time of inspection. On the map display part 55 , the defined region is indicated as an image processing region 200 together with the image processing condition number. After creating the image processing region 200 as mentioned above, the user presses the defect redisplay button 207 to confirm that each pattern defect 11 belonging to the image processing region 200 is not indicated. When the image processing region 200 is set up as required, the user presses the recipe save bitten 134 . Thus, data regarding the image processing region 200 , the image processing condition number corresponding thereto, and the image processing condition 201 for each image processing number are saved in a recipe. After saving the above data, the user presses the completion button 161 to return to the trial inspection defect check screen. Further, on the trial inspection defect check screen, the user presses the inspection end button 144 to return to the trial inspection initial screen. Then, it is possible for the user to select another die for trial inspection. For confirming and terminating the above-mentioned recipe creation session, the user presses the recipe creation end button 133 . Upon completion of the recipe creation, the wafer 31 is unloaded back to the cassette 114 . The following describes the inspection operation. In the inspection operation, the user opens the startup screen shown in FIG. 9 on the operation display 45 . On the slot selection part 130 of the startup screen, the user selects a code number of a slot where the wafer 31 to be inspected is contained. Then, on the recipe selection part 131 , the user specifies a product type of the wafer 31 and a process step thereof, and the user presses an inspection start button 330 for starting the inspection operation. After wafer loading, alignment and calibration are performed, inspection processing is carried out. Then, defect check and defect data output are performed, and wafer unloading is carried out at the end of inspection. The inspection processing and defect check, which form essential parts of the present invention, will now be described. When the user presses the inspection start button 330 to indicate the start of inspection, the stage 6 is driven for movement to a scanning start position of the region to be inspected on the wafer 31 mounted thereon. A pre-measured offset value inherent in the wafer 31 is added to the offset 112 , and the Z sensor 113 is made effective. Then, along the scanning line 33 shown in FIG. 3 , the stage 6 is scanned in the Y direction. In synchronization of this stage scanning, the deflector 105 is scanned in the X direction. During a period of effective scanning, a voltage to the blanking plate 63 is tuned off to let the electron beam 2 fall en the wafer 31 for scanning the surface thereof. Backscattered electrons or secondary electrons produced from the wafer 31 are detected by the detector 8 , and through the A/D converter 9 , a digital image of the stripe region 34 is attained. The digital image thus attained is stored into the memory 109 . After completion of the scanning operation of the stage 6 , the Z sensor 113 is made ineffective. The entire region of interest can be inspected by repeating stage scanning. In cases where the entire surface of the wafer 31 is to be inspected, the scanning sequence shown in FIG. 12 is adopted. When the detection position A 35 is selected in the image processor circuit 202 , an image attained at the detection position A 35 is compared with an image attained at the detection position B 36 , which has been stored in the memory 109 . If any difference is found in comparison, the difference is extracted as a pattern defect 11 to prepare a list of pattern defects 11 . The list of pattern defects 11 thus prepared is sent to the general control part 110 . After completion of inspection of the entire region of interest, an inspection defect check screen, such as shown in FIG. 15 , is opened. The inspection defect check screen comprises a defect display editing part 150 for displaying feature quantity data of defects and editing classification thereof, a map display part 55 in which a current position indicator 59 indicating the current position and class code symbols of pattern defects 11 are displayed on a layout of the wafer 31 , an image display part 56 in which an image taken at the current position is displayed, a display changeover button 151 for turning on/off masked defects 43 , and an inspection end button 144 for indicating the end of inspection. The user sets the mouse operation command button 140 to the selection mode, and then clicks any pattern defect 11 indicated on the map display part 55 . Thus, an image of the pattern defect 11 is presented on the image display part 56 , and feature quantity data thereof is presented on the defect display editing part 150 . On the defect display editing part 150 , the pattern defect 11 is subjected to classification according to the image and feature quantity data thereof, i.e., a class code is assigned to the feature quantity data of the pattern defect 11 . A display changeover button 209 is provided for turning on/off the display for the image processing condition 201 in the image processing region 200 . With this button, the user can perform a display changeover according to whether or not the image processing condition 201 is applied to each pattern defect 11 in the image processing region 200 . If, by using the special condition on/off button 208 , the user has specified that the image processing condition 201 is to be applied at the time of inspection, a display changeover with the image display changeover button 209 is not available since the image processing condition 201 is already applied. To terminate the inspection defect check session mentioned above, the user presses the inspection end button 144 . Each classified pattern defect 11 and feature quantity data thereof are stored into memory means (not shown) in the general control part 110 , and they are also delivered to external memory means (not shown) through a communication line (not shown) or to other inspection/observation means (not shown). Then, control is returned to the initial screen. According to one aspect of the second preferred embodiment, the entire surface of each wafer can be inspected using a SEM image thereof without regard to pattern defects in the image processing region 200 , i.e., true pattern defects 57 only can be indicated to the user for easy identification thereof. Further, according to another aspect of the second preferred embodiment, it is possible to display defects in the image processing region 200 . Therefore, in cases where rough patterning is used to form a redundant power wiring layer, the degree of roughness in patterning can be examined by means of display changeover. Still further, according to another aspect of the second preferred embodiment, an image processing condition can be set so that false defects identified under actual inspection conditions will not be detected. It is therefore possible for the user to specify a threshold properly just as required. Furthermore, according to another aspect of the second preferred embodiment, a different image processing region 200 can be created additionally. Therefore, in cases where the image processing condition 201 has been defined using an object containing a small degree of random variation, the user can set up a new image processing region additionally to provide proper conditioning for image processing as required. Moreover, according to another aspect of the second preferred embodiment, the image processing condition 201 is adjustable without completely deleting data of pattern defects 11 an the image processing region 200 . Therefore, the user can adjust the image processing condition 201 so that false defect detection will be prevented as required while possible defects remain inspectable. Still further, according to another aspect of the second preferred embodiment, in cases where, by using the special condition on/off button 208 , the user has specified that the image processing condition 201 is not to be applied at the time of inspection, it is possible to alter the image processing region 200 and the image processing condition 201 . Therefore, even if it becomes necessary to provide a different image processing condition due to variation in a fabrication process, the user has only to adjust the image processing condition 201 . Thus, inspection can be carried out using feature quantity data acquired already. Embodiment 3 A third preferred embodiment of the present invention will now be described. FIG. 18 shows an example of the configuration of an electron-beam pattern inspection apparatus according to the third preferred embodiment of the present invention. The electron-beam pattern inspection apparatus comprises an electron optical system including: an electron source 1 for emitting an electron beam 2 in the form of an electron gun in which the electron beam 2 from the electron source 1 is extracted and accelerated by an electrode to produce a virtual electron source at a predetermined point through an electrostatic or magnetic field superimposing lens; a condenser lens 60 for converging the electron beam 2 from the virtual electron source at a predetermined convergence point; a blanking plate 63 which is equipped in the vicinity of the convergence point of the electron beam 2 for turning on/off the electron beam 2 ; a deflector 105 for deflecting the electron beam 2 in the X and Y directions; and an objective lens 4 for converging the electron beam 2 onto an object substrate 5 . Further, the electron-beam pattern inspection apparatus comprises: a specimen chamber 107 in which the object substrate (wafer 31 ) is held in a vacuum; a stage 6 where the wafer 31 is mounted and to which a retarding voltage 108 is applied for enabling detection of an image at an arbitrary position; and a detector 8 for detecting secondary electrons 7 or the like produced from the object substrate to output a detected analog signal. An A/D converter 9 is provided for converting the detected analog signal into a digital image, which is stored in a memory 109 for storing digital image data, and an image processor circuit 10 compares the converted digital image with a reference digital image stored in the memory 109 and identifies a difference found in the comparison as a candidate defect 40 . A candidate defect memory part 41 is provided for storing feature quantity data 203 of each candidate defect 40 , such as coordinate data, projection length data and shape data. A feature quantity check part 251 is provided in which feature quantity data 203 of each candidate defect 40 is received from the candidate defect memory part 41 and it is checked to see whether the candidate defect 40 meets prespecified feature quantity data 250 . A detail image processing part 252 is provided in which, under an image processing condition 201 specified for each feature quantity data, a judgment for determining each pattern defect 11 is formed on the candidate defect 40 that has proved to meet the prespecified, feature quantity data 250 as determined by the feature quantity data check part 251 , and a general control part 110 receives data of each pattern defect 11 from the detail image processing part 252 (control lines from the general control part 110 are not shown in FIG. 18 ). An operation display 45 is provided on which data of pattern defects 11 is displayed, an image of a selected pattern defect 11 is displayed, and the image processing region 200 is displayed or edited. Still further, the electron-beam pattern inspection apparatus comprises a keyboard, a mouse and a knob (not shown) for operation and control; a Z sensor 113 for measuring the height level of each wafer 31 to maintain a focal point of a detected digital image through control of a current applied to the objective lens by adding an offset 112 ; a loader (not shown) for loading the wafer 31 from its cassette 114 to the specimen chatter 107 and unloading the wafer 31 from the specimen chamber 107 to the cassette 114 ; an orientation flat detector (not shown) for positioning the wafer 31 according to the circumferential shape of the wafer 31 ; an optical microscope 118 for providing for observation of a pattern on the wafer 31 ; and a standard specimen 119 which is set en the stage 6 . Operations in the third preferred embodiment include a conditioning question, in which feature quantity data 250 and an image processing condition 201 thereof are set up, and an inspection operation, in which pattern defects 11 are detected. In the conditioning operation, the user opens the startup seen shown in FIG. 9 on the operation display 45 . On a slot selection part 130 of the startup screen, the user selects a code number of a slot where the wafer 31 to be inspected is contained. Then, on a recipe selection part 131 , the user specifies a product type of the wafer 31 and a process step thereof, and the user presses a recipe creation start button 132 for starting the conditioning operation. Conditioning operation includes contrast setting for the electron optical system, pattern layout setting for the wafer 31 , pattern positioning alignment for the wafer 31 , calibration in which a signal level of the wafer 31 is checked at a position where the signal level is indicated accurately, inspection condition setting, image processing feature quantity data setting for specifying feature quantity data 250 and an image processing condition 201 thereof, and setup condition check in trial inspection. The contrast setting, image processing feature quantity data setting, and trial inspection, which form essential parts of the present invention, will now be described. The general control part 110 provides operational instructions to each part in the following manner. First, the general control part 110 issues an operational instruction to the loader (not shown) so that the loader takes the wafer 31 out of the cassette 114 . Then, through the use of the orientation flat detector (not shown), the circumferential shape of the wafer 31 is checked, and the wafer 31 is positioned according to the result of this check. The wafer 31 is then mounted on the stage 6 , and the specimen chamber 107 is evacuated. Simultaneously, the electron optical system 106 and the retarding voltage 108 are conditioned. A voltage is applied to the blanking plate 63 to turn off the electron beam 2 . The stage 6 is moved so that the standard specimen 119 can be imaged, and an output of the Z sensor 113 is made effective. While a focal point of the electron beam 2 is maintained at a position corresponding to “a value detected by the Z sensor 113 +an offset 112 ”, raster scanning is performed by the deflector 105 . In synchronization with this raster scanning, the voltage applied to the blanking plate 63 is turned off so that the wafer 31 is irradiated with the electron beam 2 as required. Backscattered electrons or secondary electrons produced from the wafer 31 are detected by the detector 8 , which then outputs a detected analog signal. Through the A/D converter 9 , the detected analog signal is converted into a digital image. By changing the offset 112 , a plurality of digital images are detected, and in the general control part 110 , an optimum offset for maximizing the sun of image differential values is determined. The optimum offset thus determined is set up as the current offset value. After the optimum offset is established, the output of the Z sensor 113 is made ineffective, and a screen transition is made to a contrast adjustment screen, such as shown in FIG. 10 . The contrast adjustment screen comprises: a map display part 55 having a map display area, a button for controlling display of the entire wafer or die, map, and a mouse operation command button 140 for controlling position movement or item selection by the use of the mouse (not shown); an image display part 56 having an image display area and an image changeover button 141 for setting an image magnification, selecting an optical micrograph image obtained through the optical microscope 118 or a SEM image obtained through the electron optical system, and specifying a kind of image; a recipe creation item selection button 142 ; a recipe creation end button 133 ; and a recipe save button 134 . On the contrast adjustment screen, the user sets the mouse operation command button 140 to a movement mode, and performs movement on the map by clicking the mouse to view an image at the current position on the image display part. Then, the user assigns an adjustment item of the electron optical system, to the knob, and adjusts each part of the electron optical system to attain proper contrast. The recipe creation end button 133 is used for terminating recipe creation; the recipe save button 134 is used for saving recipe condition data; and the recipe creation item selection button 142 is used for setting another condition and issuing an instruction for screen transition. These buttons are available on all the screens. To open a trial inspection initial screen, such as shown in FIG. 11 , the user sets the recipe creation item selection button 142 to a trial inspection item. The trial inspection initial screen comprises a map display part 55 , a recipe creation end button 133 , a recipe save button 134 , a recipe creation item selection button 142 , an inspection start button 143 , and an inspection end bit ton 144 . The user sets the mouse operation command button 140 to a selection mode. Then, by clicking a die on the map display part 55 , the user can select/deselect the die for trial inspection. Each die can thus be selected for trial inspection. After selecting any die for trial inspection, the user presses the inspection start button 143 to start trial inspection. When trial inspection is started, the stage 6 is driven for movement to a scanning start position of the region to be inspected on the wafer 31 mounted thereon. A pre-measured offset value inherent in the wafer 31 is abed to the offset 112 , and the Z sensor 113 is made effective. Then, along the scanning line 33 shown in FIG. 3 , the stage 6 is scanned in the Y direction. In synchronization with this stage scanning, the deflector 105 is scanned in the X direction. During a period of effective scanning, a voltage to the blanking plate 63 is turned off to let the electron beam 2 fail on the wafer 31 for scanning the surface thereof. Backscattered electrons or secondary electrons produced from the wafer 31 are detected by the detector 8 , and through the A/D converter 9 , a digital image of the stripe region 34 is obtained. The digital image thus obtained is stored into the memory 109 . After completion of the scanning operation of the stage 6 , the Z sensor 113 is made ineffective. The entire region of interest can be inspected by repeating stage scanning. In cases where the entire surface, of the wafer 31 is inspected, a scanning sequence shown in FIG. 12 is carried out. When the detection position A 35 is selected in the image processor circuit 10 , an image obtained at the detection position A 35 is compared with an image obtained at the detection position B 36 , which has been stored in the memory 109 . If any difference is found in comparison, the difference is extracted as a candidate defect 40 and feature quantity data of the candidate defect 40 is stored into the candidate defect memory part 41 . Simultaneously at the feature quantity data check part 251 , it is checked to see whether the candidate defect 40 meets prespecified feature quantity data 250 or not. If the candidate defect 40 meets the prespecified feature quantity data 250 , data of the candidate defect 40 is sent to the detail image processing part 252 . Then, in the detail image processing part 252 , image processing is carried out under an image processing condition 201 determined for each prespecified feature quantity data to check whether the candidate defect 40 is a pattern defect 11 or not. If the candidate defect 40 is recognized as a pattern defect 11 , an identification, code thereof stored in the candidate defect memory part 41 is sent to the general control part 110 . After completion of inspection of the entire region of interest, a defect check screen, such as shown in FIG. 19 , is opened. The defect check screen comprises a defect display editing part 150 for displaying feature quantity data of defects and editing classification thereof; a map display part 55 , in which a current position indicator 59 indicating the current position and class code symbols of pattern defects 11 are displayed on a layout of the wafer 31 ; an image display part 56 , in which an image taken at the current position is displayed; a real/memory image display changeover button 255 for effecting a changeover between a real, image display and a memory image display, and other buttons which have already been described. The user sets the mouse operation command button 140 to the selection mode, and then clicks any pattern defect 11 indicated on the map display part 55 . Then, if a real image selection has been made with the real/memory image changeover button 255 , a coordinate location of the pattern defect 11 is taken for image acquisition. If a memory image selection has been made with the real/memory image changeover button 255 , an image of the pattern defect 11 is presented on the image display part 56 , and feature quantity data thereof is presented on the defect display editing part 150 . On the defect display editing part 150 , the pattern defect 11 is subjected to classification according to the image and feature quantity data thereof, i.e., a class code is assigned to the feature quantity data of the pattern defect 11 . At this step, if it is desired to treat the pattern defect 11 as a defect not to be detected 58 , a particular class code is assigned thereto. Thus, it can be identified as a defect not to be detected on the map display part 55 . After completion of the defect classification, the user makes a transition to an image processing feature quantity data setting screen, as shown in FIG. 20 , using the recipe creation item selection button, or the user returns to the trial inspection initial screen by pressing the inspection end button. The image processing feature quantity data setting screen comprises a class code specifying part 262 for specifying a class code of interest 261 ; a defect selection part 263 for selecting defects having the class code of interest in succession; a feature quantity data specifying part 264 for specifying feature quantity data of each selected defect and feature quantity data 250 used as a selection criterion; a map display part 55 ; an image display part 56 , in which an image of each defect 11 is displayed; an image processing condition setting part 265 for setting up an image processing condition number corresponding to an image processing condition 201 to be applied to an image selected by the feature quantity data specifying part 264 ; a defect redisplay button 207 for indicating on the map display part 55 the result of judgment attained after an evaluation image processing part 252 checks to see whether or not an image in the candidate defect memory part 41 is a pattern defect 11 ; a new feature quantity data creation button 266 for creating a new image processing condition number corresponding to prespecified feature quantity data 250 ; a completion button 161 for indicating the end of creation of new feature quantity data; and other buttons which have already described. The recipe save button 134 is provided for saving data in a recipe. After saving the data, the user presses the completion button 161 to return to the trial inspection defect check screen. Further, en the trial inspection defect check screen, the user presses the inspection end button 144 to return to the trial inspection initial screen. Then, it is possible for the user to select another die for trial inspection. For confirming and terminating the above-mentioned session, the user presses the recipe creation end button 133 . Upon completion of the recipe creation, the wafer 31 is unloaded back to the cassette 114 . The inspection operation will now be described. In the inspection operation, the user opens the startup screen shown in FIG. 9 on the operation display 45 . On the slot selection part 130 of the startup screen, the user selects a code number of a slot where the wafer 31 to be inspected is contained. Then, on the recipe selection part 131 , the user specifies a product type of the wafer 31 and a process step thereof, and the user presses an inspection start button 330 for starting the inspection operation. After wafer loading, alignment and calibration are performed, inspection processing is carried out. Then, defect check and defect data output are performed, and wafer unloading is carried out at the end of inspection. The inspection processing and defect check, which form essential parts of the present invention, will now be described. When the user presses the inspection start button 330 to indicate the start of inspection, the stage 6 is driven for movement to a scanning start position of the region to be inspected on the wafer 31 mounted thereon. A pre-measured offset value inherent in the wafer 31 is added to the offset 112 , and the Z sensor 113 is made effective. Then, along the scanning line 33 shown in FIG. 3 , the stage 6 is scanned in the Y direction. In synchronization of this stage scanning, the deflector 105 is scanned in the X direction. During, a period of effective scanning, a voltage to the blanking plate 63 is turned off to let the electron beam 2 fall on the wafer 31 for scanning the surface thereof. Backscattered electrons or secondary electrons produced from the wafer 31 are detected by the detector 8 , and through the A/D converter 9 , a digital image of the stripe region 34 is obtained. The digital image thus attained is stored into the memory 109 . After completion of the scanning operation of the stage 6 , the Z sensor 113 is made ineffective. The entire region of interest can be inspected by repeating stage scanning. In cases where the entire surface of the wafer 31 is inspected, the scanning sequence shown in FIG. 12 is employed. When the detection position A 35 is selected in the image processor circuit 202 , an image obtained at the detection position A 35 is compared with an image obtained at the detection position B 36 , which has been stored in the memory 109 . If any difference is found in comparison, the difference is extracted as a candidate defect 40 and stored in the candidate defect memory part 41 . Further, the feature quantity data check part 251 selects a candidate defect meeting the prespecified feature quantity data, and using an image processing condition 201 determined by an image processing condition number corresponding to the prespecified feature quantity data, the detail image processing part 252 formed a judgment on whether or not the candidate defect 40 is a pattern defect 11 so as to prepare a list of pattern defects 11 . The list of pattern defects 11 thus prepared is sent to the general control part 110 . After completion of inspection of the entire region of interest, a defect check screen such as shown in FIG. 15 is opened. The defect check screen comprises a defect display editing part 150 for displaying feature quantity, data of defects and editing classification thereof; a map display part 55 , in which a current position indicator 59 indicating the current position and class code symbols of pattern defects 11 are displayed on a layout of the wafer 31 ; an image display part 56 in which an image taken at the current position is displayed; a display changeover button 151 for turning on/off candidate defects 41 with pattern defects 11 indicated; and an inspection end bit ten 144 for indicating the end of inspection. The user sets the mouse operation command button 140 to the selection mode, and then clicks any pattern defect 11 indicated on the map display part 55 . Thus, an image of the pattern defect 11 is presented on the image display part 56 , and feature quantity data thereof is presented on the defect display editing part 150 . On the defect display editing part 150 , the pattern defect 11 is subjected to classification according to the image and feature quantity data thereof, i.e., a class code is assigned to the feature quantity data of the pattern defect 11 . A display changeover button 209 is provided for turning on/off the display for the image processing condition 201 in the image processing region 200 . With this button, the user can perform a display changeover according to whether or not the image processing condition 201 is applied to each pattern defect 11 in the image processing region 200 . If, by using the special condition on/off button 208 , the user has specified that the image processing condition 201 is to be applied at the time of inspection, a display changeover with the image display changeover button 209 , is not available, since the image processing condition 201 is already applied. To term mate the inspection defect check session mentioned above, the user presses the inspection end button 144 . Each classified pattern defect 11 and feature quantity data thereof are stored into memory means (not shown) in the general control part 110 , and they are also delivered to external memory means (not shown) through a communication line (not shown) or to other inspection/observation means (not shown). Then, control is returned to the initial screen. According to one aspect of the third preferred embodiment, the entire surface of each wafer can be inspected using a SEM image thereof to detect true pattern defects 57 only. Thus, the user can identify the true pattern defects 57 with ease. Further, according to another aspect of the third preferred embodiment, in cases where rough patterning is used to form a redundant power wiring layer or a pattern edge, the degree of roughness in patterning can be examined by means of display changeover. Still further, according to another aspect of the third preferred embodiment, an image processing condition can be set so that false defects identified under actual inspection conditions will not be detected. It is therefore possible for the user to specify a threshold properly just as required. Furthermore, according to another aspect of the third preferred embodiment, the image processing condition 201 is adjustable without completely deleting data of pattern defects 11 in the image processing region 200 . Therefore, the user can adjust the image processing condition 201 so that false defect detection will be prevented as require d while possible defects remain inspectable. As set forth hereinabove, and according to the present invention, the user can set up a non-inspection region that is effective for a device having a complex, large pattern area to be inspected, such as a wafer. Further, in cases where a considerable difference is found in comparative inspection of detected images, even if the difference is not actually a defect, the present invention makes it possible to avoid false defect detection while carrying out detection of minuscule defects. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which care within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

A pattern inspection method in which an image can be detected without an image detection error caused by an adverse effect to be given by such factors as ions implanted in a wafer, pattern connection/non-connection, and pattern edge formation. A digital image of an object substrate is attained through microscopic observation thereof, the attained digital image is examined to detect defects, while masking a region pre-registered in terms of coordinates, or while masking a pattern meeting a pre-registered pattern, and an image of each of the defects thus detected is displayed. Further, each of the defects detected using the digital image attained through microscopic observation is checked to determine whether its feature meets a pre-registered feature or not. Defects having a feature that meets the pre-registered feature are so displayed that they can be turned on/off, or they are so displayed as to be distinguishable from the other defects.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. Ser. No. 09/846,826, filed May 1, 2001; which is a continuation of U.S. Ser. No. 09/021,892, filed Feb. 11, 1998, now U.S. Pat. No. 6,287,764, issued Sep. 11, 2001; which claims the benefit of U.S. Provisional application Serial No. 60/037,054, filed Feb. 11, 1997. FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] This invention was developed through assistance with the National Marrow Donor Program (NMDP, contract number 7105) and the Department of Defense, Office of Naval Research (grant number N00014-95-9974). BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention relates in general to a method for direct DNA sequencing of HLA-A, -B, and -C alleles and more particularly the invention entails the sequence based typing of exons 2 and 3 for the HLA allele gene under study. [0005] 2. Brief Description of the Related Art [0006] MHC has the highest genetic polymorphism of the mammalian DNA molecules. Questions are raised by this polymorphism, such as its molecular basis, degree, and functional significance. For analysis of MHC polymorphism and its relationship to immune responses and disease susceptibilities, the human species has considerable scientific advantages, as well as direct relevance to clinical medicine. Only in human populations is there likely to be extensive analysis of MHC polymorphism from many geographically separated populations. The crystal structure of the human class I molecule has also been previously disclosed, making accurate insights into other HLA class I molecules possible as well as the allelic polymorphism of the HLA-A, B and C genes. [0007] The HLA class I genes are a component of the human major histocompatibility complex (MHC). The class I genes consist of the three classical genes encoding the major transplantation antigens HLA-A, HLA-B and HLA-C and seven non-classical class I genes, HLA-E, HLA-F, HLA-G, HLA-H, HLA-J, HLA-K, and HLA-L. [0008] The classical HLA class I genes encode polymorphic cell surface proteins expressed on most nucleated cells. The natural function of these proteins is to bind and present diverse sets of peptide fragments from intracellularly processed antigens to the T cell antigen receptors (TCRs). Thus, the peptide-binding capacity of the MHC molecule facilitates immune recognition of intracellular pathogens and altered self proteins. Therefore, by increasing the peptide repertoire for TCRs, the polymorphism of MHC molecules plays a critical role in the immune response potential of a host. On the other hand, MHC polymorphism exerts an immunological burden on the host transplanted with allogeneic tissues. As a result, mismatches in HLA class I molecules are one of the main causes of allograft rejection and graft versus host disease, and the level of HLA matching between tissue donor and recipient is a major factor in the success of allogeneic tissue and marrow transplants. It is therefore a matter of considerable medical significance to be able to determine the “type” of the HLA class I genes of candidate organ donors and recipients. [0009] HLA class I histocompatibility antigens for patient-donor matching are conventionally determined by serological typing. Biochemical and molecular techniques have revealed that HLA class I polymorphism is far greater than previously recognized by conventional methods. To date, over 59 HLA-A, 127 HLA-B, and 36 HLA-C different allelic sequences have been identified. This high level of allelic diversity complicates the typing of the HLA class I genes. [0010] Another complicating factor is the large number of homologous genes and alleles. Each of the HLA class I genes is composed of eight exons and seven introns and the sequences of these exons and introns are highly conserved across the HLA class I genes. Allelic variations mostly occur in exons 2 and 3 which are flanked by noncoding introns 1, 2, and 3. These two exons encode the functional domains of the molecules. [0011] Taken together, these two complications make HLA class I typing at the nucleic acid level a formidable task. Allelic diversity within any one gene means that a great many probes need to be developed if hybridization-based tests are used in the typing. Further, the general applicability of DNA typing methods to HLA class I genes depends on the design of primers which provide effective locus-specific amplification of exons 2 and/or 3 of one HLA class I gene. [0012] One method for performing HLA class I typing is disclosed in U.S. Pat. No. 5,424,184 which is incorporated herein by reference. This patent utilizes primers which are located within exons 2 and 3 of the HLA class I genes to achieve what is described as group-specific amplification of a portion of the HLA-A, HLA-B, and HLA-C genes. This approach is not ideal, however, since the primers hybridize with portions of the coding strand, and thus may mask significant allelic variations. In addition, this method requires a grouping of alleles by means of another method in order to select group-specific primers for amplification. [0013] Prior to inclusion of polymerase chain reaction (PCR) into the cloning and sequencing of HLA class I alleles the accumulation of class I sequences was a cumbersome act. The advent of the PCR greatly accelerated the accumulation of class I HLA sequences. Since then, research has been undertaken to bring molecularly-based HLA class I and class II typing techniques to the point where they would be clinically useful and cost-beneficial for the many applications such as bone marrow donor registry and disease association studies. [0014] Using the bone marrow donor registry as an example, the impetuses driving the development of new semi-automated and automated molecular techniques for high-resolution class I and class II typing could be characterized as: (1) the pool of available donors in the registry were poorly HLA typed: many HLA class I types are of low resolution and many clinically deleterious class I types were missed; (2) questions pertaining to discriminatory power of serology had to be addressed: serological HLA typing does not correlate with a high degree of accuracy with the molecular typing of HLA alleles; (3) it is recognized that continual HLA typing will be required to establish and maintain a donor registry of sufficient size; and (4) typing methods based on DNA sequence have many advantages over conventional serologic typing techniques including the elimination of typing complications due to different tissue distributions of MHC antigens, the use of defined reagents available in unlimited quantities (in contrast to alloantisera which are chemically ill-defined, limited in amount, and frequently monopolized), and the ability to provide an absolute HLA type. [0015] For HLA class II molecules, high resolution clinical typing using the polymerase chain reaction (PCR) with sequence specific primers (SSP) and/or sequence specific oligonucleotide probes (SSOP) is now a routine procedure. This advance in class II typing was essential because alloantisera, traditionally used for class I typing, proved especially inadequate for typing class II antigens. An additional advantage of DNA based HLA typing is that viable cells are not required. [0016] An increasing appreciation of the complexity and the extent of HLA class I polymorphism has consequently developed. The shortcomings of current class I serological typing procedures became more apparent, as did the need for a high resolution molecular typing technique. As a logical extension of methods successfully employed for class II typing several groups have applied PCR/SSP and/or PCR/SSOP methodologies to molecularly type HLA class I alleles. At first these applications were most successful for the subtyping of class I antigens for which there are multiple variants (e.g. A2, B27). These techniques subsequently began to prosper for the typing of all alleles at the HLA-A, and C loci, with the HLA-B locus providing the most resistance to these typing methodologies. [0017] The nucleic acid sequencing of class I HLA molecules has revealed numerous serological typing inadequacies, and the availability of cell lines containing sequenced class I alleles has been instrumental for the development of PCR primer and probe based typing techniques. Well characterized cell lines serve as important developmental standards and controls for these arriving class I molecular typing techniques. It is anticipated that this will hold true for emerging HLA-B typing protocols. [0018] Attempts to eliminate cloning from the determination of HLA class I sequences has been undertaken. To obviate cloning for direct sequence based class I typing three difficulties arise. The first difficulty is that sequence based typing must frequently resolve two nucleotides at one rung of the sequencing ladder; heterozygosity is the norm, and two alleles at one locus may differ by as many as 85 nucleotides. We therefore sought a DNA sequencer designed to utilize a single fluorophore, eliminating complications which might arise from different fluorophores simultaneously fluorescing in the same lane at heterozygous positions. The second difficulty is the occurrence of band compressions in the sequencing ladder due to the high G/C content of class I molecules. Past experience dictates that optimal resolution of G/C band compressions is obtained with a T7 sequencing chemistry utilizing 7-deaza dGTP. A third difficulty encountered by all who type class I HLA molecules is their polymorphic nature; once the class I DNA sequence is obtained, it is often difficult to assign a class I type to the data generated. [0019] The problem addressed is that for the successful transplantation of organs and bone marrow, for the proper diagnosis of autoimmune disorders such as arthritis, and for research studies trying to establish a link between a particular disease and immune response genes, an accurate class I HLA type must be established. However, clinical HLA class I typing laboratories (which now use antibodies for typing) cannot accurately discriminate among the many different class I genes found in the population. Therefore, molecular DNA based methods are being tested to facilitate more precise HLA class I typing. [0020] Others are testing molecular DNA class I HLA typing methodologies. Some rely on the failure or ability to PCR amplify a gene, with several hundred PCR reactions needed to call a class I type. This is termed SSP (sequence specific PCR). Other techniques utilize one HLA-A, -B, and -C locus specific PCR reaction followed by hybridization with a complex series of oligonucleotide probes. This technique is referred to as SSOP. These techniques utilize a similar first step—an HLA-A, -B, and -C locus specific PCR reaction—followed by divergent methods for typing the HLA-A, -B, or -C specific PCR product. [0021] A comparison of SSP, SSOP, and the present invention which we will term “sequence based typing” (SBT) shows that SBT gives a precise class I HLA type, while SSP and SSOP give only a partial type, i.e. they probe portions of the genes being typed while SBT reads all of the gene being typed. The reason others have been reluctant to adopt a sequence based typing approach is because the technology is complex and developing. [0022] Due to the fact that SBT gives the most precise class I type, several other groups have tried to develop a class I HLA SBT method. What individuates the techniques described herein is: (1) amplification of HLA-A, -B, or -C class I alleles such that exons 2 and 3 are produced in a locus specific way to facilitate (2) production of a secondary HLA-A, -B, or -C locus specific polymerase chain reaction by separately amplifying exons 2 and 3 using the primary polymerase chain reaction product as a template and nested or heminested polymerase chain reaction primers and (3) preparing the secondary polymerase chain reaction product such that it has an anchoring moiety at one terminus and a DNA sequencing primer site at the opposing terminus and (4) following attachment to a solid support the secondary polymerase chain reaction products are then DNA sequenced. [0023] Thus, the novel aspect of our approach is that HLA-A, -B, or -C locus specific nested polymerase chain reaction products are produced at a level of purity sufficient for DNA sequence based typing. Furthermore, these secondary polymerase chain reaction products can be anchored to a solid support prior to DNA sequencing with a universal DNA sequencing primer. SUMMARY OF THE INVENTION [0024] We have developed a method for typing HLA class I alleles in order to determine the HLA-A, -B, or -C type of a sample. Our method comprises two amplification steps to amplify, purify, and separate exons 2 and 3 in a locus specific manner. In particular, the method comprises the steps of: (a) amplifying HLA-A, -B, or -C alleles so as to provide a primary amplicon, wherein the primary amplicon comprises amplified exons 2 and 3 of the HLA-A, -B, or -C alleles in a locus specific manner; (b) producing at least two secondary HLA-A, -B, or -C locus specific amplicons corresponding to each of the exons 2 and 3 of the primary amplicon, wherein the at least two secondary amplicons are produced by amplifying the primary amplicon by means of using the primary amplicon as a template and nested polymerase chain reaction primers, thereby independently framing each of exon 2 and exon 3; (c) preparing the at least two secondary amplicons for sequencing, wherein the at least two secondary amplicons are provided with an anchoring moiety attached to a first terminus of each of the at least two secondary amplicons and a sequencing primer site attached to a second terminus of each of the at least two secondary amplicons; (d) attaching the anchoring moiety of each of the at least two secondary amplicons to solid supports; and (d) DNA sequencing each of the at least two secondary amplicons. [0025] In a preferred embodiment, the method further comprises the step of analyzing the DNA sequence of the at least two secondary amplicons so as to provide an HLA class I type for the at least two secondary amplicons. It is also contemplated that in the step of preparing the at least two secondary amplicons, the anchoring moiety comprises a biotin molecule and that the DNA sequencing primer comprises a M13 universal primer, such as primer GTA AAA CGA CGG CCA. [0026] The invention also comprises a method for determining tissue compatibility. In particular this method is comprised of the steps of: (a) obtaining a sample of tissue, wherein the sample of tissue contains an amount of DNA encoding the HLA-A, -B, or -C alleles; (b) amplifying the HLA-A, -B, or -C alleles so as to provide a primary amplicon, wherein the primary amplicon comprises amplified exons 2 and 3 of the HLA-A, -B, or -C alleles in a locus specific manner; (c) producing at least two secondary HLA-A, -B, or -C locus specific amplicons corresponding to each of the exons 2 and 3 of the primary amplicons, wherein the at least two secondary amplicons are produced by amplifying the primary amplicon by means of using the primary amplicon as a template and nested polymerase chain reaction primers located in introns 1, 2, and 3, thereby independently framing each of exon 2 and exon 3; (d) preparing the at least two secondary amplicons for sequencing, wherein the at least two secondary amplicons are provided with an anchoring moiety attached to a first terminus of each of the at least two secondary amplicons and a sequencing primer site attached to a second terminus of each of the at least two secondary amplicons; (e) attaching the anchoring moiety of each of the at least two secondary amplicons to solid supports; (f) DNA sequencing each of the at least two secondary amplicons; and (g) comparing the DNA sequence of the at least two secondary amplicons with at least one predetermined tissue sample. BRIEF DESCRIPTION OF THE DRAWINGS [0027] [0027]FIG. 1 is a flow diagram showing in particular the steps for determining a class I HLA sequence-based type with the direct DNA sequence analysis of the present invention. [0028] [0028]FIG. 2 is a diagram indicating the primers and introns/exons used in determining a class I HLA sequence-based type with direct DNA sequence analysis, showing in particular the primers listed in Table 1 and their relative positioning during the amplification steps. [0029] [0029]FIG. 3 is a chromatogram showing a heterozygous position (arrow) on a Pharmacia ALF automated DNA sequencer in accordance with the method for determining a class I HLA sequence-based type with direct DNA sequence analysis of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0030] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. [0031] The invention encompasses a method for determining HLA type via HLA-A, -B, -C locus specific amplification of exons 2 and 3 (as shown diagrammatically in FIG. 1). In particular, the method includes performing two nested PCR's on exon 2 and two hemi-nested PCR's on exon 3. The purpose of these nested PCR reactions is to generate PCR products which are approximately 350 nucleotides in length and to produce PCR products containing anchoring moieties for binding to a solid phase medium such as a Streptavidin coated support, wherein the Streptavidin coated support may be a comb or bead or any other structure capable of binding the PCR product. For sequence based typing of HLA class I alleles the claimed invention utilizes two DNA sequencing reactions per exon, with the sequencing primers built onto the PCR primer which opposes the biotinylated primer so that universal sequencing primers flank the exons being sequenced (FIG. 2). In this way, bidirectional sequences throughout exons 2 and 3 can be obtained. Read lengths in which class I HLA heterozygous positions are resolved generally range from 300-350 nucleotides from either direction, with heterozygous positions proximal to the sequencing primers best resolved. Following this scheme, positions of heterozygosity immediately adjacent to each primer are most clearly resolved, while it becomes more difficult to resolve heterozygous positions as reads progress beyond 350 bases from each sequencing primer. Before determining a class I type the invention requires that the positions of heterozygosity be clearly resolved beyond 200 nucleotides for both sequencing reads in each exon. [0032] Once it is clear that heterozygous positions 200 or more nucleotides from each primer can be resolved, the two sequencing reads at each exon are assembled and then combined with the assembled sequence from the other exon for that sample. It is at the assembly of the two sequencing reads for each exon that the typing software is required. With a software package capable of assembling the exon 2 and the exon 3 DNA sequences, opposing reads for each exon are automatically reversed complemented, aligned, and linked together, after which the software combines the sequence of exons 2 and 3 for each sample. The software then compares all possible combinations of HLA-A, -B, or -C alleles in an existing HLA class I database to the assembled sequencing data. The software then sequentially ranks the pairs of HLA class I alleles which best fit the sequence data and lists the number of positions not consistent with the best fit pair of alleles in the class I database. [0033] The software is arranged so that ambiguities and questioned calls are flagged, and flagged calls are readily viewed in the chromatograms which are present in the software window. The technique described herein is not foolproof in that <1% of the HLA-A and HLA-B heterozygous combinations of alleles are non-unique through exons 2 and 3 and cannot be resolved with this SBT technique. For example, the current method cannot distinguish a B*1501/B*4008 DNA sequence combination from a B*1508/B*4002 individual, such that a second class I HLA typing step (i.e. PCR-SSP) or a third sequencing reaction through exons 4-8 will sometimes be required. However, this is true of any technique that types only exons 2 and 3. One of ordinary skill in the art would appreciate that the level of resolution obtained is beyond that of other methodologies. [0034] In the present invention, primers utilized in the primary PCR are different to previously published HLA locus-specific amplification primers Cereb et al., Tissue Antigens 47:498-511 (1996). However, most important is that the PCR product generated in the primary PCR is not directly evaluated to determine an HLA type. Rather it is used as an intermediate template for a secondary nested PCR which amplifies exons 2 and 3 separately. In the secondary PCR either the 5′ or 3′ primer is labeled with a generic, M13 universal, primer site to facilitate annealing of a DNA sequencing primer and the opposing 5′ or 3′ primer is labeled with an anchor, biotin, to promote solid phase DNA sequencing. Also of significance is that one of the two nested secondary PCR primers used to amplify each exon contains locus specificity to avoid evaluation of undesired amplicons obtained in the primary PCR. Those nested PCR primers are located in the introns flanking exons 2 and 3. This technique therefore requires two rounds of locus-specific amplification prior to HLA class I evaluation. The secondary PCR product is then evaluated to determine an allelic HLA class I type. [0035] The inventor is aware that these primers may be modified by introducing degenerate bases where alternative bases may occur as new alleles are detected. These primers may also be made somewhat longer or shorter. Other modifications may include the introduction of various generic sequencing primer sites other than the M 13 universal sequencing primer site used here and the use of alternative moieties other than Biotin for the adherence of the sequencing product to a solid-phase medium such as, but not limited to, combs, magnetic beads, or plates which are coated with a complementary substance possessing an affinity for the generated sequencing product. EXAMPLE I [0036] Once a sample is obtained, the first step is to treat the tissue sample so as to obtain nucleic acids for amplification. The method herein described can be performed on whole blood, tumor cells, sperm, hair follicles, or any other nucleated tissue sample. [0037] A. Locus Specific Amplification of HLA-A, -B, -C Alleles and of Exons 2 and 3 [0038] Genomic DNA was extracted from 200 μL of whole blood using the Qiagen DNA extraction kit otherwise known as a “QIAamp blood kit” according to the supplied protocol. Exons 2 and 3 of HLA class 1-A, -B, and -C loci were PCR amplified from 500 ng of genomic DNA using 20 picomoles of HLA class I locus specific primers located within introns 1 and 3 (Table 1). [0039] The primers listed in Table 1 correspond to the bases which are the same across the introns and are indicated as a single base (A, C, G, T), while bases which are variable across the introns are indicated by a code for alternative bases. In general, it will be advantageous to select the primer that will avoid the variable bases. [0040] Specific buffers and reagents used for this PCR have been previously described in the literature and one of ordinary skill in the art would appreciate that any PCR buffer is contemplated for use provided that it functions to amplify exons 2 and 3. [0041] Once the sample has been treated, it is combined with two amplification primers and amplified, for example using PCR amplification. The basic process of PCR amplification is known, for example from U.S. Pat. Nos. 4,683,202 and 4,683,195, which are incorporated herein by reference. In PCR amplification, two amplification primers are used, each of which hybridizes to a different one of the two strands of a DNA duplex. Multiple cycles of primer extension, and denaturation are used to produce additional copies of DNA extending from the position of one primer to the position of the other. In this way, the number of copies of the genetic material positioned between the two primer binding sites is increased. [0042] In the present invention, amplification of exons 2 and 3 is preferably performed using at least one locus-specific primer which specifically hybridizes to a portion of intron 1 or intron 3. As used in the specification and claims hereof, the primers which “specifically hybridize” to the introns are primers which permit locus-specific amplification by having a sequence which is exactly complementary to the expected sequence of a portion of the intron so that binding and amplification can occur, but which is not complementary to a region on any of the other HLA class I genes. It will be understood that locus-specific primers within the scope of this invention need not be complementary to a totally unique sequence within the human genome, provided that both members of the primer pair used in amplification do not bind to the same gene outside the gene of interest. [0043] Amplification primers useful in the present invention are generally from 10 to 40 bases in length, more preferably from 17 to 35 bases in length. Within this size range, we have identified suitable locus-specific, group-specific and allele-specific primers for each of the classical HLA class I genes. [0044] Degenerate bases can be introduced in the primer sequences where alternative bases occur among alleles. These primers are complementary to the region of the non-coding strand spanning nucleotides 26-46 and 21-45, respectively of the intron 1 sequence shown in FIG. 2 (Seq. ID No.: 1). It will be appreciated that this primer could be made longer by adding additional complementary bases to the 5′-end. The primer might also be made somewhat shorter, for example spanning nucleotides 26-44, since nucleotides 23, 24, and 25 are identical across the various HLA-locuses in sequences of which the inventors are aware. In addition to primers binding to the non-coding strand, it will be appreciated that complementary primers which bind to the corresponding portions of the coding strand could be used with a compatible second primer. The use of longer or shorter locus-specific primers, and of complementary locus-specific primers are within the scope of the present invention. [0045] While PCR amplification is the preferred approach to amplification of the treated sample, other techniques which use oligonucleotide primers to define a region of DNA to be amplified can be used as well. Such techniques include ligase chain reaction amplification (Wiedmann et al., PCR Primer, Laboratory Manual, Cold Spring Harbor (1991)). [0046] The first amplification procedure results in the production of an amplified product, in which the region of the HLA-A, -B, or -C gene between the two primers is significantly increased in concentration relative to other genetic material in the treated sample. [0047] The first PCR amplification was accomplished on a thermocycler programmed for an initial denaturation cycle of 960, 2:00; then 39 cycles of 940, 0:30; 560, 0:50+1s/cycle; 720, 0:30+2s/cycle. Individual exons obtained from the first locus specific PCR amplification were then amplified a second time individually by (5 μL of a 1:200 dilution) using 10 picomoles of HLA class I locus and exon specific primers listed in Table 1. Reagents contained within this 60 μL PCR were as follows: 10 mM Tris-HCl, (pH 8.3) 50 mM KCl, 1.5 mM MgCl 2 , 0.001% (w/v) gelatin, 0.2 mM dNTPs and 2.5U of Taq DNA polymerase. Cycling conditions for this PCR were 30 cycles of 950, 1:00; 540, 1:00; 720, 1:00. [0048] B. Direct DNA Sequencing Approach [0049] Once exons 2 and 3 have been amplified a first time together and a second time separately, they may be sequenced directly and as generally described in Santamaria et al., Hum. Immunology 37:39-50 (1993). The twice amplified product can be sequenced using the well-known dideoxy chain termination method. Briefly, in this method a sequencing primer complementary to one strand of the amplified product is combined with the amplified product, a template-dependent polymerase enzyme, a mixture of the four standard nucleotide bases (A, G, T, and C) and one type of dideoxy nucleotide base. The bases are added to the end of the amplification primer to form a new oligonucleotide complementary to the amplification product. When a dideoxy base is added, however, no additional bases can be added. This results in the formations of a family of oligonucleotides whose lengths reflect the positions of the nucleotide base provided in dideoxy form within the complementary oligonucleotide. By evaluating the fragments formed in four reactions mixtures, one for each type of dideoxy nucleotide base, by gel electrophoresis, the sequence of the complementary strand can be deduced. [0050] Basic procedures for performing nucleic acid sequencing in this manner are well known in the art, and commercial instruments are available for this purpose. Thus, sequencing is a routine procedure provided that amplified DNA and suitable primers are available. In this case, the same primers used to amplify the DNA can be used as sequencing primers. [0051] Nested intron primers can also be used as sequencing primers. These primers are complementary to the sequences of the amplified products located in intron 1, intron 2, or intron 3 (SEQ ID Nos.:1-9). It is particularly advantageous to have “universal” sequencing primers which could be used in the sequencing of any of the major transplantation antigen genes after locus-specific amplification, and such primers are an aspect of the present invention, such as universal primer M13. [0052] Use of the AutoLoad Solid Phase Sequencing Kit from Amersham Pharmacia Biotech was used for this portion of the DNA sequencing, however, one of ordinary skill in the art would appreciate that any sequencing kit or sequencing method capable of solid phase sequencing is contemplated for use. The AutoLoad Solid Phase Sequencing Kit is designed for the direct sequencing of PCR products on the ALF” family of automated DNA sequences from Amersham Pharmacia Biotech. The Amersham Pharmacia sequencing comb efficiently captures PCR products up to 800 base-pairs in length for use as single-stranded sequencing templates. The sequencing comb enhances sample throughput by eliminating the tedious pipetting normally required when manually loading sequencing gels. The optimized mixtures of ultrapure deoxy- and dideoxynucleotides contain 7-deaza dGTP (c 7 dGTP) in place of dGTP to minimize problems associated with band compressions and resolutions of heterozygous positions. Components Reagent Kit Reagents: A Mix ddATP 11.9 μM dATP 2.38 mM dCTP 2.38 mM c7dGTP 1.0 mM dTTP 2.38 mM Tris-HCl, pH 7.6 95.2 mM NaCl 119 mM C Mix ddCTP 11.9 μM dATP 2.38 mM dCTP 2.38 mM C7dGTP 1.0 mM dTTP 2.38 mM Tris-HCl, pH 7.6 95.2 mM NaCl 119 mM G Mix ddGTP 5.0 μM dATP 2.38 mM dCTP 2.38 mM c7dGTP 1.0 mM dTTP 2.38 mM Tris-HCl, pH 7.6 95.2 mM NaCl 119 mM T Mix ddTTP 11.9 μM dATP 2.38 mM dCTP 2.38 mM c7dGTP 1.0 mM dTTP 2.38 mM Tris-HCl, pH 7.6 95.2 mM NaCl 119 mM [0053] For best results, removal of the stock T7DNA polymerase from storage at −20° C. is minimized except for momentarily to remove an aliquot. During use, all other reagents are kept on ice until required. TABLE 1 First Round PCR Amplification Primers: Bases Amplicon Primer Primer Sequence 5′ to 3′ Exon from Exon Position Length 5′AI-1 SGC CTC TGY GGG GAG AAG CAA 2-3 105 26-46 (I1) 938 5′BI-1 GAG GAG MRA GGG GAG CGC AG 2-3 92 38-58 (I1) 940 5′CI-1 CGA GGK GCC CGC CCG GCG A 2-3 87 44-61 (I1) 911 3′AI-3 GGG AGA YCT AYA GGC GAT GAG G 2-3 46 26-57 (I3) 938 3′BI-3 AGS CCA TCC CCG SCG ACC TAT 2-3 56 38-58 (I3) 940 3′BCI-3 AGA TCC GGA AGG CTC CCC ACT 2-3 32 12-33 (I3) 911 [0054] [0054] Sense or Bases Amplicon Primer Primer Sequence 5′ to 3′ Exon Antisense from Exon Position Length 5′I1E2A G CGC CKG GAS GAG GGT C 2 Sense 47  84-100 (I1) 351 5′I1E2B G CGC CGG GAG GAG GGT C 2 Sense 47  84-100 (I1) 351 5′I1E2C T CGG GCG GGT CTC AGC C 2 Sense 32  99-115 (I1) 336 3′I2E2ABC G TCS TGA CCT SCG CCC C 2 Antisense 34 18-34 (I2) 351 3′I2E2ABC G TCS TGA CCT SCG CCC C 2 Antisense 34 18-34 (I2) 351 3′I2E2ABC G TCS TGA CCT SCG CCC C 2 Antisense 34 18-34 (I2) 336 5′I2E3A G GGG GAG YGG GCT GAG C 3 Sense 33 234-251 (I2) 355 5′12E3B A CKG GGC TGA CCG CGG G 3 Sense 28 240-256 (I2) 360 5′12E3C T GAG CRC GGG GGC GGG G 3 Sense 21 247-263 (I2) 329 3′AI-3 G GGA GAY CTA RAG GCG ATC AGG 3 Antisense 46 26-57 (I3) 355 3′BI-3 A GSC CAT CCC CGS CGA CCT AT 3 Antisense 56 38-58 (I3) 360 3′BCI-3 A GAT GGG GAA GGC TCC CCA CT 3 Antisense 32 12-33 (I3) 329 [0055] D. Overview of DNA Sequencing Methodology [0056] Although one method of sequencing is hereinbelow provided, one of ordinary skill in the art would appreciate that any method of sequencing could be chosen—i.e. cycle sequencing with TAQ polymerase—yet within the scope contemplated by the present invention. The AutoLoad Solid Phase Sequencing Kit is designed for the direct sequencing of PCR products on the ALF family of automated DNA Sequencers from Pharmacia Biotech. Sequencing is performed using one M13 universal primer tailed primer and one biotinylated primer. The PCR product is captured on a specially designed sequencing comb containing immobilized streptavidin, and the non-biotinylated strand of the PCR product is removed by alkaline denaturation. The immobilized single-stranded product which remains bound to the sequencing comb is then used as a template in dideoxy sequencing reactions using a fluorescently labelled M13 universal primer. The products of the sequencing reaction remain bound to the immobilized template strand until the comb is loaded on the sequencing gel. The wells of the sequencing gel are filled with stop solution, which releases the fluorescently labelled sequencing fragments from the combs. The combs are removed from the sequencing gel and the sequence is started through the computer using a sequence analysis algorithm, one of which could be used is ALF Manager™. [0057] The secondary PCR amplicons (exon 2 and exon 3) may also be sequenced without being bound to a solid support structure—i.e. sequencing may take place in solution or in any other manner compatible with sequencing. [0058] We use the AutoLoad Solid Phase Sequencing Kit to sequence 10 PCR products simultaneously. The Kit provides sufficient combs, reaction plates and reagents to sequence 100 PCR products using T7 DNA Polymerase. One 8-tooth sequencing comb is capable of capturing two templates; four teeth are required per template. The sequencing comb efficiently captures our PCR products of 350 base-pairs and works best with 0.5 mm sequencing gels. The specially designed sequencing combs eliminate the tedious pipetting required when manually loading sequencing gels. [0059] E. Immobilization of the Biotinylated PCR Product [0060] This example describes the simultaneous sequencing of 10 PCR products using the AutoLoad Solid Phase Sequencing Kit. It should be noted, however, that many solid supports would suffice for immobilizing the nested PCR products. Using the AutoLoad Solid Phase Sequencing Kit, a total of five, 8-tooth sequencing combs are required for 10 PCR templates. The sequencing combs can be attached together via the plastic pegs located on each comb and processed as a single unit. The reagent volumes stated in the following instructions are the volumes required to sequence 10 templates. The number of sequencing combs and some reagent volumes must be adjusted if sequencing fewer than 10 templates, one of ordinary skill in the art would be aware of the means to adjust said volumes. [0061] Initially, confirmation must be taken that the PCR product is of the correct size and that the quality and quantity are good (i.e. one sharp band of the expected length and quantity) by agarose electrophoresis. Typically, 40-50 μl of a PCR reaction contains at least 2 pmol of product. This can also be expressed as 1.4 μg/kb PCR product, i.e. to sequence a 350 bp PCR fragment, 700 ng of the product is needed. [0062] Second, addition of 80 μl of 0.5× Binding/Washing buffer (1× binding buffer=2M NaCl+10 mM Tris pH 7.5+1 mM EDTA) to each well of a 10-well plate and then addition of 40-50 μl of PCR reaction mixtures to each of the wells. In order to achieve proper comb orientation when loading sequencing gels the pegs on the sequencing combs should point away from the user when placed on the plate wells. [0063] Third, PCR products are bound to a solid phase support; placing the five, 8-tooth sequencing combs (attached together) in the plate wells and mix gently by moving the combs up and down 2-3 times; incubating the 10-well plate at 65° C. for 30 minutes or at room temperature for at least one hour to ensure complete immobilization of the PCR products on the combs; washing the combs by dipping them in TE buffer in a clean petri dish or allow them to stand for 2 minutes. Immobilization of the PCR product on the sequencing comb is confirmed after incubation by analyzing 4-6 μl of the supernatant from the wells by agarose gel electrophoresis. In this case, the supernatant is simply the solution which remains in the well after the comb is removed. [0064] F. Template Denaturation [0065] Removal of the non-biotinylated strands of the PCR products by alkaline denaturation must be undertaken by placing 120 μl of 0.1 M NaOH solution in each well of a fresh 10-well plate. Place the combs in the wells of the plate and incubate at room temperature for 5 minutes. Remove the combs from the plate and wash the combs by dipping them first in 0.1 M NaOH followed by washes with TE and sterile water. [0066] G. Primer Annealing [0067] The Cy5 μm-labelled M13 sequencing primer is used in all DNA sequencing reactions. Add the following to each well of a fresh 10-well plate: (1) Annealing buffer—12 μl; (2) Labelled primer—4 μl (4 pmol); and (3) Sterile water—104 pG. Place the file sequencing combs containing the immobilized DNA in the wells of the plate. Heat the plate to 65° C. for 5-10 minutes. Allow the plate to cool at room temperature for 1-10 minutes before proceeding. [0068] H. Sequencing Reactions [0069] Using cold Enzyme Dilution Buffer, dilute the T7 DNA Polymerase to a concentration of 6-8 units/μ. Forty μl of diluted polymerase is required when sequencing 10 templates. Dilute only enough of the stock of T7 DNA Polymerase for immediate use. The diluted polymerase may be stored at 40° C. for up to one week. Mix by gentle pipetting and keep on ice until needed. For maximum stability, do not remove the stock of T7 DNA Polymerase from storage at −20° C. except momentarily to remove an aliquot for dilution. [0070] In order to minimize the pipetting steps required to fill the 40-well plates used for the sequencing reactions, it is necessary to prepare four master mixes, one for each of the four nucleotides. The instructions given for mixtures in Table 2 provide sufficient master mix for the sequencing of 10 PCR templates (one full sequencing gel). TABLE 2 Reagent Volume Nucleotide Mix (A, C, G or T) 30 μl Annealing Buffer 20 μl Extension Buffer 10 μl Sterile Water 190 μl Diluted T7DNA Polymerase 10 μl DMSO 20 μl [0071] Dispense 19 μl of the A ™master mix™to each of the 10 ™A™wells of a fresh 40-well sequencing reaction plate. Repeat for the other three nucleotide master mixes, placing 19 μl of each mix in the appropriate wells (in the order: A, C, G, T). Prewarm the plate to 370 for 1 minute. Add the combs to the plate, mix (make sure that no air bubbles are trapped in the wells) and incubate at 37° C. for 5 minutes. Place the plate on ice until ready to load on the sequencer. [0072] I. Loading on the ALF DNA Sequencer [0073] Prepare a 6% polyacrylamide gel. Set the water temperature for the thermo plate to 55° C. using the control panel of ALF Manager waiting at least 15 minutes after the gel has reached the set temperature, which is confirmed using ALF Manager, before inserting the sequencing combs in the ALF gel. Add 10 μl of Stop solution to each well of the sequencing gel using a multi-dispensing pipette. Add the same volume of Stop solution to each well for optimal performance. Separate the combs and wash them in the upper buffer reservoir of the sequencer. Place the sequencing combs in the wells, being careful not to push too much of the Stop solution out of the wells. Push the combs down to within approximately 1 mm of the bottom of the gel-wells. Let stand for 10 minutes. Carefully remove the combs, close the lid, set the ALFred thermoplate at 55° C. and start software sequencing. [0074] Loading samples via a combination of pipette and sequencing combs on the same gel can cause lane wandering due to salt concentration differences between the two sample types. For this reason, it is important to specifically commit the DNA sequencers to class I typing as described in this example solely. [0075] In this manner, the HLA-A, -B, or -C alleles can be specifically typed by means of sequence based typing of exons 2 and 3. After receiving sequences for exons 2 and 3, the sequences are combined and compared to an HLA sequence database in order to obtain allele typing. EXAMPLE 2 [0076] We first obtained cells for category two typing. The cells we received required HLA-A, -B, and -C nucleotide sequence analysis. After thawing and resuspending the cells in RPMI 1640 supplemented with 15% fetal calf serum, 10 U/ml penicillin, 10 mg/ml streptomycin, and 2 mM L-glutamine, the cells were counted and cell viability was determined using trypan exclusion. Each sample contained approximately 5×10 6 total cells, however, viability varied significantly between the three samples. A summary of the cells received and their work-up is shown in Table 3. TABLE 3 # of Cells Alleles Pre-Test Sample # Category Received Viability Sequenced 0121-3981-2 HLA-A 5 × 10 6 <10% N.D. 0121-2817-9 HLA-B 5 × 10 6 <10% N.D. 0121-5337-5 HLA-C 5 × 10 6 >90% Cw*0802, *02022 0104-8698-3 2a; HLA-A 5 × 10 6 >90% N.D. 0104-9545-5 2b; HLA-B 5 × 10 6 >90% B*1510, *5001 [0077] As can be seen from Table 3, samples 3981-2 and 2817-9 were not viable. [0078] Sample 0121-5337-5 was sequenced according to the method hereinabove described and it was determined that Cw*0802 and Cw*02022 were the HLA-C alleles encoded by sample 5337-5. As HLA-B locus is the most polymorphic of the classical HLA class I loci and it is for the HLA-B locus where molecular class I typing techniques have struggled the most, we proceeded typing samples 8698-3 and 9545-5. We sequenced the HLA-B alleles from sample 0104-9545-5 and determined the HLA-B type of this cell line to be B*1510, B*5001. EXAMPLE 3 [0079] Samples 1548 through 1579 (as shown in Table 4) were received as frozen transformed lymphocytes excepting samples 1551, 1552 and 1553 which were delivered as granulocytes. Once these samples were assigned their respective run numbers processing began. DNA extraction using the QIAMP 96 Spin Blood kit was carried out yielding sufficiently good quality DNA at a suitable concentration for primary PCR amplification. 25 μl primary PCR reactions were set up and were checked by loading 5 μl of the amplicon on a 2% agarose gel run at 200 volts for twenty minutes. [0080] Once it was established that the primary PCR had produced a suitable product this was then diluted 1:200 with distilled water ready for the secondary PCR reactions. Each dilution was then used in the four secondary PCR reactions with the resulting amplicons again being checked on a 2% agarose gel. The secondary PCR products then underwent solid phase sequencing reactions using the Amersham Pharmacia Autoload SPS kit and the samples were then loaded onto 6% Page Plus gel and run on a Pharmacia Alfexpress automated DNA sequencer. [0081] The data produced was then analyzed using the Pharmacia HLA Sequityper software (version 2.0) by two independent operators with the results being compared. The HLA type was thereafter reported. TABLE 4 NMDP # Run # HLA Type 506-927-512-4 1548 CW*0701, 0701 524-926-495-3 1549 CW*0401, 0602 508-926-702-2 1550 CW*0401, 0401 524-927-299-8 1551 CW*0304, 0501 025-0057-0571-0 1552 CW*0602, 0701 539-926-509-1 1553 CW*1601, 1601 087-0093-3019-2 1554 CW*0303, 1601 583-931-288-5 1555 CW*0102, 0501 045-0075-2598-3 1556 CW*0602, 0701 087-0092-5150-5 1557 CW*0304, 0702 030-0161-1687-3 1558 CW*02022, 0702 592-932-151-4 1559 CW*0702, 0802 506-922-242-3 1560 CW*0304, 0701 557-924-917-8 1561 CW*02024, 1701/02 030-0075-9305-6 1562 CW*0304, 1601 060-0076-8680-1 1563 CW*0303, 0304 087-0093-9732-4 1564 CW*0702, 1601 501-932-447-6 1565 CW*0701, 0802 506-907-189-5 1566 CW*02022, 0304 530-932-412-0 1567 CW*0501, 0702 024-0089-5886-0 1568 CW*0602, 0701 060-0080-9292-6 1569 CW*0702, 0702 590-928-963-8 1570 CW*0401, 0501 087-5002-7421-2 1571 CW*0303, 0602 063-0033-4666-5 1572 CW*0702, 0702 087-0141-0955-7 1573 CW*0304, 1602 530-932-168-8 1574 CW*0602, 0704 533-932-432-8 1575 CW*0501, 0702 501-932-620-8 1576 CW*0702, 0802 039-0157-1178-1 1577 CW*0304, 0501 506-928-758-2 1578 CW*0401, 0701 524-931-139-0 1579 CW*0303, 0602 EXAMPLE 4 [0082] As shown in Table 5, during the year of 1997, the invention was used to complete the typing of 1,452 HLA-A, 104 HLA-B, and 2,7776 HLA-C samples. All HLA-C typings were done in duplicate by the American Red Cross in Maryland and all HLA-A typings were duplicated at Oakland Childrens Hospital. Both the Oakland and Maryland facilities are accredited HLA typing laboratories performing PCR-SSOP. Our discrepancy rate with these laboratories was less than 3%, demonstrating a high concordance with other laboratories and typing methodologies in this field using the invention as described herein. TABLE 5 Discrepancy Sister Typings Number Rate Laboratory HLA -A 1,452 2.95% Oakland HLA -B 104 Not Determined None HLA -C 2,776 2.84% Maryland Red Cross [0083] Thus, it should be apparent that there has been provided in accordance with the present invention a method of typing a sample for its HLA-A, -B, or -C type which satisfies the objectives and advantages set forth above. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims. 1 1 1 15 DNA artificial sequence completely synthesized 1 gtaaaacgac ggcca 15

There is provided a method for directly typing or sequencing HLA-A, -B, or -C alleles from a tissue sample wherein exons 2 and 3 of the HLA-A, -B, or -C alleles from the sample are amplified together in a locus specific manner and then separated out and individually amplified in a locus specific manner. After the two amplifications, the amplified exons are directly sequenced, the sequences are recombined, and a comparison is made between the derived HLA allele sequence and an HLA allele database, thereby giving an exact HLA-A, -B, or -C type for the sample being tested.

BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to ophthalmic or dermatological compositions for external use, and more specifically, to such external medicines when used for the purpose of mediating healing of injured ocular tissue or treating ophthalmic diseases with ophthalmic compositions containing vitamin D (ergocalciferol or cholecalciferol), or for the purpose of protecting ocular tissue or skin from harmful ultraviolet rays with ophthalmic or dermatological compositions containing vitamin D or vitamin K. 2. Description of the Related Art Vitamin D2, which is refined from vitamin D1 containing other isomers and is highly antirachitic, and vitamin D3, which was researched after vitamin D2, are often used today for the treatment of patients suffering from rickets, osteomalacia, osteoporosis, osteatis fibrosa, osteosclerosis and other bone diseases, malignant tumors such as breast and colon cancers, and skin diseases such as psoriasis. In general, the term "vitamin D" by itself is used to refer to highly antirachitic vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). In general, the ultraviolet (UV) light absorption spectra of vitamin D and active vitamin D have absorption maxima near 265 nm, with molar absorption coefficients of about 18,000. Their UV light absorption bands are in the 240-290 nm range. For example, ergocalciferol, 25-monohydroxyvitamin D2, 1alpha,25-dihydroxyvitamin D2, 24,25-dihydroxyvitamin D2 and others have UV light absorption spectra with maxima near 265 nm, and molar absorption coefficients of about 18,900. In addition to these vitamins, provitamin D and previtamin D also have similar UV light absorption spectra. The provitamins D ergosterol and 7-dehydrocholesterol have respective molar absorption coefficients of 11,000 and 10,920, and UV light absorption spectra with maxima at 271, 281 and 293 nm. The previtamins D pre-ergocalciferol and pre-cholecalciferol both have molar absorption coefficients of 9,000 and UV light absorption spectra with absorption maxima at 260 nm. Therapeutic vitamin D is administered orally or by injection, and is applied to the skin as an active vitamin D ointment in the case of skin conditions. It is known that the molecular structure of vitamin D is altered in the liver and kidneys, converting it into biologically active vitamin D. Hitherto it has been thought that the topical human use of the vitamins D ergocalciferol or cholecalciferol was useless for the treatment of local tissue, as for the treatment of psoriasis, for example. Since the discovery of calcitriol (1alpha,25-dihydroxycholecalciferol), an active form of vitamin D which is derived from cholecalciferol, it has come to be understood that vitamin D has physiological actions other than calcium regulation. Active vitamins D formed by hydroxylation of the C1 position of the A-ring of the sterol nucleus, side-chain C25 or both C1 and C25 include calcitriol (1alpha,25-dihydroxyvitamin D), 1alpha,24-dihydroxyvitamin D, alfacalcidol (1alpha-monohydroxyvitamin D), calcifediol (25-monohydroxyvitamin D), 1alpha,24,25-trihydroxyvitamin D, 1beta,25-dihydroxyvitamin D, oxacalcitriol, calcipotriol and KH1060. Analogues include dihydrotachysterol. It is now known that there are active vitamin D receptors in the cells, and the inhibition of cell activity is being studied since active vitamin D inhibits the production of a variety of cytokines. The known ophthalmic symptoms of vitamin deficiency include nyctalopia, Bitot's spots of the conjunctiva and xerosis of the conjunctiva and cornea resulting from vitamin A deficiency, beriberi amblyopia resulting from vitamin B1 deficiency, and diffuse superficial keratitis, retrobulbar neuritis and optic atrophy occurring in cases of vitamin B2 deficiency, as well as hemorrhaging of the eyelid, conjunctiva and retina which are seen in cases of scurvy resulting from vitamin C deficiency. Hyperplasia occurs in the cells of the keratitis site during the process of wound recovery in postoperative corneal surgery patients, and in some cases the metabolites of hyperplastic cells may also cause corneal opacity and changes in corneal refraction. Although there are normally 5 layers of epithelial cells in the cornea, the corneal epithelium which covers the stroma may grow to about 10 layers of cells if trauma is complex and reaches into the keratocytes. When trauma reaches into the stroma, the activated keratocytes form hyperplasia and produce excess metabolites to speed healing. Although the stratified epithelial cells eventually return to normal, corneal refraction and transparency are affected by transient epithelial stratification and the metabolites of the stratified cells and activated keratocytes. Although corticosteroids are administered following corneal surgery, steroid-induced glaucoma and steroid-induced cataracts are known to occur as side-effects. Surgeries to repair an injured cornea and ophthalmic surgeries which traumatize the cornea include surgery to correct corneal refraction, cataract surgery, intraocular-lens implant surgery, pterygium surgery, surgery to remove a corneal foreign body, corneal transplantation and corneoplasty. Corneal dystrophy occurs when metabolic abnormalities of the epithelium, keratocytes or endothelium result in the accumulation mainly of isomeric proteins in the keratocytes, causing corneal opacity. Types of corneal dystrophy include granular corneal dystrophy, macular corneal dystrophy, lattice corneal dystrophy, gelatinous drop-like dystrophy, Schnyder's corneal dystrophy and Francois's corneal dystrophy. In corneal ulceration, on the other hand, ulcers are caused by the product of excessive collagenase in the corneal epithelium. Consequently, corneal dystrophy and corneal ulceration differ in their causes and clinical signs. It is well known that UV light is injurious to the eyes. In particular, wavelengths of 200 to 315 nm can potentially cause actinic keratitis, and in general radiation of 260 nm is known as a cause of teratogenesis and carcinogenesis in the cells. It is also well known that UV light is injurious to the skin. In particular, wavelengths of 200 to 315 nm can potentially lead to sunburn, spots and freckles. UV light at a wavelength of 260 nm is thought to be a cause of skin cancer. Moreover, existing UV blocker should not be used in or around the eyes. The stratospheric ozone layer prevents UV at wavelengths below 286 nm from reaching the surface of the earth. However, the ozone layer is said to be 2-4 mm in thickness under 1 atmosphere, it is reported that fluorine compounds and methyl bromide are destabilizing the ozone layer, and increased rates of skin cancer are being reported from South America and Australia. In general, the peak wavelength of conventional UV sterilizers is 254 nm. On the first page of the Ocular Surgery News, Vol. 9, No. 11, published in U.S.A. on Jun. 1, 1991, it was reported that patients being treated after excimer laser keratectomy can experience impaired vision and edema caused by UV light. In corneal disease patients, there is hyperplasia of the cells at the keratitis site, and corneal transparency and refraction may also be adversely affected by the metabolites of such cells. Inflammed keratocytes produce excessive metabolites. Apart from inflammation, there are also corneal diseases in which collagenase and isomeric proteins are seen as metabolites of the corneal epithelial cells and activated keratocytes. The metabolites of stratified cells affect corneal refraction and transparency. It is known that corticosteroids are not effective for treating corneal diseases in which collagenase and isomeric proteins are present. In general, corneal diseases include keratitis, corneal ulceration and corneal dystrophy. In cataract surgery, generally extracapsular cataract extraction is performed, leaving behind the posterior capsule and the periphery of the anterior capsule. However, cells of the epithelium lentis remain inside the capsule. These residual cells gradually proliferate and spread, and they and their metabolites such as collagen may cause secondary cataracts in which there is opacity of the lenticular capsule and the patient's vision is adversely affected. A two-line drop in test types resulting from such secondary cataracts occurs among approximately 10% of cataract patients within 1 year after surgery, and among approximately 20% of patients within 2 years after surgery. Keratoconjunctival dryness, also known as "dry eye," is a focus of dispute among ophthalmologists. In the Japanese medical journal Ganka New Insight 5, published by Medical Review, there is mention of the corneal epithelium, vitamin A deficiency and keratoconjunctivitis sicca, and vitamin D is also mentioned in connection with the epidermis. Keratoconjunctival dryness is discussed extensively in the Japanese journal Dry Eye, published by Nihon Hyoronsha. These sources state that there is a profound connection between vitamin A deficiency and diseases of the corneal and conjunctival epithelium, but they also conclude that abnormalities of the corneal and conjunctival epithelium do not occur clinically in vitamin D deficiency, and that vitamin D is not involved in the eye. The journal Dry Eye classifies "dry eye" into two separate conditions, decreased lacrimation and keratoconjunctivitis sicca, which are caused respectively by reduced lacrimation and damage to the cornea and conjunctiva. It is thought that keratoconjunctival dryness is caused partly by environmental factors including decreased nictation while watching a computer or television screen, windy days, dusty environments, ozone and nitrogen oxides. It is said that keratoconjunctival dryness occurs when some factor causes keratinization of the corneal epithelial cells, the conjunctival goblet cells and the nongoblet epithelial cells. As a result, either tears are not retained in the cornea and conjunctiva, or else an abnormal decrease in one of the three layers that form the tears (the mucin layer, lacrimal layer and oil layer) occurs as a result of inflammation of the cornea or conjunctiva, resulting in keratoconjunctival dryness. Conventional treatments for keratoconjunctival dryness include artificial tears, dry eye glasses, Chinese medicine and lacrimal punctal plugs. Among its other effects, vitamin K acts as a blood coagulation factor. Recently the association between vitamin K and bone metabolism action is being studied. Also, it has been reported that vitamin K amplifies the bone metabolism action of vitamin D3. Vitamin K has a UV absorption band in the 240-270 nm range and is fat soluble. Vitamins K2 are the menaquinones, which have repeating side chains. More specifically, vitamin K1 has a molecular weight of 450.7 and UV absorption maxima at 242-269 and 325 nm, while vitamin K2 (menaquinone 7) has a molecular weight of 649.2 and absorption maxima at 243-270 and 325-328 nm. SUMMARY OF THE INVENTION The first purpose of this invention is to provide ophthalmic compositions for preventing corneal opacity and corneal refractive error following corneal trauma. The second purpose of this invention is to provide ophthalmic compositions for treating corneal disease and preventing corneal opacity and corneal refractive error. The third purpose of this invention is to provide ophthalmic compositions for preventing and treating keratoconjunctival dryness. The fourth purpose of this invention is to provide ophthalmic compositions for preventing secondary cataracts after cataract surgery. The fifth purpose of this invention is to provide ophthalmic compositions for protecting ocular tissue against harmful UV light. The sixth purpose of this invention is to provide dermatological compositions for protecting skin against harmful UV light. Firstly, the inventor arrived at this invention by considering that when a form of vitamin D which is not yet active, that is, ergocalciferol or cholecalciferol, is applied topically to the eye, it enters cells that need to be regulated, is converted to an active form, and either induces the differentiation of those cells, or else regulates the various proteins which are produced by the cell in the cytoplasm. Consequently, in this invention the vitamin D ergocalciferol or cholecalciferol as an effective ingredient is administered directly to the eye to regulate wound healing of ocular tissue and prevent or treat corneal dystrophy or keratoconjunctival dryness. This invention provides an ophthalmic composition which regulates healing of traumatized ocular tissue after ophthalmological surgery including surgery to repair an injured cornea, surgery to correct corneal refraction, cataract surgery, intraocular-lens implant surgery, pterygium surgery, surgery to remove a corneal foreign body, corneal transplantation and corneoplasty, and which also cures granular corneal dystrophy, macular corneal dystrophy, lattice corneal dystrophy, gelatinous drop-like corneal dystrophy, Schnyder's corneal dystrophy and Francois's corneal dystrophy and other forms of corneal dystrophy, and prevents corneal opacity and corneal refractive error. Secondly, the inventor arrived at this invention by considering that all K vitamins or vitamins D including provitamins D and vitamin D metabolites would be safe for human use if used externally to absorb the UV light which is thought to be harmful to the human body. Keratoconjunctival dryness, also called "dry eye," is caused partly by environmental factors including decreased nictation, windy days, dusty environments, ozone and nitrogen oxides. As a result, there is keratinization of the corneal epithelial cells, the conjunctival goblet cells and the nongoblet epithelial cells. Such keratoconjunctivitis sicca reduces tears, resulting in keratoconjunctival dryness. Therefore, these are the ophthalmic compositions for preventing or treating keratoconjunctival dryness, having either vitamin D, active vitamin D or one of their analogs as its effective ingredient. Effective forms of vitamin D include ergocalciferol or cholecalciferol as well as active forms of vitamin D formed by hydroxylation of the C1 position of the A-ring of the sterol nucleus, side-chain C25 or both C1 and C25. The active vitamin D analog dihydrotachysterol also falls in the category of ophthalmic compositions for preventing or treating keratoconjunctival dryness. In the vitamin D medicine of this invention, vitamin D is applied not for its antirachitic activity, but in order to induce differentiation of conjunctival goblet cells, conjunctival nongoblet epithelial cells and corneal epithelial cells which have keratinized or are about to keratinize in cases of keratoconjunctival dryness. In other words, the administered vitamin D has no effect on intact cells, but it induces the differentiation of conjunctival goblet cells, conjunctival nongoblet epithelial cells and corneal epithelial cells which are affected by keratoconjunctivitis sicca. The induction of differentiation of these cells by active vitamin D is thought to occur when active vitamin D attaches directly to vitamin D receptors within the cells, forming a complex which enters the nucleus and affects the DNA, so that the cells' activities are regulated. DESCRIPTION OF THE PREFERRED EMBODIMENTS The regulation of cell activity and the induction of cell differentiation by topical ophthalmic administration of the vitamin D ergocalciferol or cholecalciferol having been confirmed in animal experiments, this invention is aimed at maintaining eye transparency and normal refraction and preventing decreased visual function by direct topical ophthalmic administration to patients suffering from ocular trauma and eye disease. The ocular cells which are regulated by vitamin D, especially in the anterior segment of the eye, include corneal epithelial cells, keratocytes and fibroblasts, endothelial cells, conjunctival goblet cells, conjunctival nongoblet epithelial cells, epithelium lentis cells and intraocular phagocytes. Topical administration of even inactive vitamins D ergocalciferol or cholecalciferol is recognized as being effective in healing inflammation and metabolic abnormalities of these cells. In order to prevent optical transparency impairment and refraction error caused by cell hyperplasia and cell metabolites while the eye is recovering from ocular tissue damage extending below the corneal epithelium and corneal metabolic abnormalities, the vitamin D ergocalciferol or cholecalciferol is used as the effective ingredient in an ophthalmic composition. Normally, orally ingested vitamin D is converted to active vitamin D in the liver or kidneys, but the vitamin D composition of this invention acts locally in the eye. The cells which are activated, keratinized or metabolically abnormal use their own vitamin D hydroxylase to convert the vitamin D which enters the cell into active vitamin D, which either affects DNA in the nucleus and induces cell differentiation, or else affects cellular RNA and influences protein synthesis, thus regulating cell hyperplasia, excess metabolite production and keratinization in these cells. For example, in this invention the fact that epithelium and fibroblasts which were differentiated from keratocytes have enzymes which convert the administered vitamin D to active vitamin D is considered and used as a means of resolving the issues described above as the first, second and third purposes of the invention. Namely, carbon C1 or C25 of the administered vitamin D is hydroxylated by the mitochondria or microsome enzymes of the fibroblasts, producing the active vitamin D which is necessary for the regulation of those cells. The amount of vitamin D which is activated depends on the activated keratocytes and the number of their differentiated fibroblasts. In other words, the keratocytes convert vitamin D to active vitamin D, but it was discovered that when the corneal stroma is traumatized, the activated keratocytes begin to differentiate and produce fibroblasts, and the rate of conversion of vitamin D into active vitamin D increases. In patients who have undergone corneal surgery, there is an obvious increase in fibroblasts in the corneal stroma. In order to prevent postsurgical changes in corneal refraction and corneal opacity, which are caused by such an increase, an eyedrop medication for example is administered to the eye after surgery to regulate the activity of the corneal epithelial and stromal cells, with the aim of inhibiting hyperplasia and excess metabolite production in the activated corneal epithelial and stromal cells and preventing a decrease in visual acuity because of corneal opacity and changes in corneal refraction. In the area of surgeries to correct corneal refraction, the ophthalmic compositions of this invention would probably not be appropriate in cases of refractive correction aimed at changing refraction by scar hyperplasia of the keratotomy incision site. In the area of cataract surgery, the administration of the ophthalmic compositions of this invention to postsurgical patients would mitigate the opacity caused by epithelial lens cells of the lenticular capsule. This invention provides an ophthalmic composition, containing the vitamin D ergocalciferol or cholecalciferol or one of their analogs as its effective ingredient, for preventing opacity of the lenticular capsule after cataract surgery. Moreover, vitamin D is used in this ophthalmic composition to protect ocular tissue against UV light, taking advantage of the fact that vitamin D has a maximum UV light absorption spectrum in the neighborhood of 260 nm. Effective forms of vitamin D include ergocalciferol and cholecalciferol or their analogs, and active forms of vitamin D formed by hydroxylation of the C1 position of the A-ring of the sterol nucleus, side-chain C25 or both C1 and C25 or their analogs. The active vitamin D analog dihydrotachysterol also falls in this category. The fifth purpose of this invention is achieved in this way. As an ophthalmic composition having fat-soluble vitamin D as its effective ingredient, one characteristic of this invention is that it improves optical refraction and transparency of the patient's cornea when administered topically to the eye. The ophthalmic composition can also be formed by diluting vitamin D in an ophthalmic physiological buffer solution in which the solvent medium is ethanol, ether or a surfactant such as lecithin or polysorbate. Since vitamin D is fat-soluble, the ophthalmic composition may contain vitamin D dissolved in a plant oil such as sesame oil or fat. The concentration of vitamin D in the prophylactic or therapeutic ophthalmic composition of this invention, since it is intended for topical administration, may be about 100 micrograms/ml or less, or at least about 0.001 micrograms/ml. The volume of one eyedrop is normally about 20-40 microliters. The concentration of active vitamin D in the ophthalmic composition should be 1 microgram/ml or less. In other words, the inventor considered that the topical administration of more than the optimum dose of active vitamin D would naturally result in a greater than optimum dose of active vitamin D for the cells. The cells themselves would then produce more hydroxylase to metabolize the active vitamin D, and the result might be a reduction in the intended therapeutic effect. When the ophthalmic composition of this invention is administered to the eyes of ophthalmological patients, the enzymes inside the activated keratocytes convert the vitamin D ergocalciferol or cholecalciferol into the necessary dose of active vitamin D. This active vitamin D then attaches to the receptors of the activated keratocytes and epithelial cells themselves or neighboring cells and influences the DNA and RNA of those cells, inducing the differentiation of the cells and regulating various cytokines, proteins and other exudates. Since the vitamins D ergocalciferol and cholecalciferol are not cytotoxic, it is thought that they will not affect normal cells unless administered at abnormal concentrations. Even when the ophthalmic composition of this invention is administered to the eyes of ophthalmological patients, the vitamins D ergocalciferol and cholecalciferol are unlikely to reach the posterior segment of the eye. If treatment of the posterior segment of the eye with vitamin D is considered in the future, it will probably be effective to use it in combination with oral administration. Vitamin D easily permeates the cornea, which is known to be permeable to pharmaceuticals which is hydrophobic and have a smaller molecular size. For example, the molecular size of cholecalciferol is 384.6 daltons. Vitamin D in tears on the cornea and conjunctiva or vitamin D which has penetrated into the cornea or conjunctiva significantly absorbs harmful UV radiation. The vitamins D ergocalciferol and cholecalciferol and their analogs are effective in preventing actinic keratitis and pterygium. Moreover, since UV light may be especially harmful to the eyes after excision of the human corneal Bowman's layer, as happens in refractive excimer laser keratectomy, for example, the ophthalmic composition of this invention containing vitamin D which absorbs harmful UV light will be effective. Ocular Surgery News reported that patients being treated after excimer laser keratectomy can experience impaired vision and edema caused by UV light. The vitamin D in the ophthalmic composition of this invention can be attached to or encapsulated in an ophthalmological drug delivery system. Such systems include liposomes, microspheres, protein gels, collagen or therapeutic soft contact lenses. The vitamin D in this invention can be mixed with at least one of the viscous materials polyvinyl alcohol, methylcellulose, hyaluronate, chondroitin sulfate, collagen, fatty acid, plant oil or fat, and used as a viscous ophthalmic solution. Appropriate formulations include eyedrops, ointment and contact lenses in particular. In patients who have undergone keratectomy or keratotomy, the corneal epithelial cells spread on the corneal stroma after surgery, and the deficient epithelial cells on the stroma are regenerated within a few days. Although epithelial cell regeneration occurs, however, hyperplasia and increased cell activity also occur in the epithelial and keratocytes on the periphery of a corneal excision or at the site of a complex excision. Scar formation caused by the metabolites of such corneal epithelial and activated keratocytes exerts traction, resulting in corneal refractive error and opacity leading to reduced visual acuity. Corticosteroids are mainly used to prevent this, but there is a tendency to avoid the use of steroids because of fears that they will cause steroid-induced glaucoma and steroid-induced cataracts as side effects. By regulating hyperplasia and cell activity in the activated corneal epithelial and keratocytes by administration of the vitamin D of this invention to patients after keratotomy or keratectomy, decreased vision due to corneal refractive error and opacity is prevented. Ocular administration of the vitamin D of this invention does not have any obvious accelerating effect at least on the speed of corneal epithelial cell regeneration. The ophthalmic composition containing vitamin D of this invention is administered to patients in order to prevent loss of transparency in human ocular tissue as a result of hyperplasia and excess metabolite production in traumatized tissue, and maintains the transparency of the eye by regulating cell activity in the traumatized tissue. Drugs such as antibiotics, antimicrobials, antiphlogistics and glaucoma drugs are used in combination after ophthalmic surgery and for treating eye disease, and it is thought that no toxicity occurs as a result of combined use with the vitamins D ergocalciferol and cholecalciferol. Japanese Patent Publication No. 4-43887 applies the calcium metabolism action of active vitamin D, and states that active vitamin D is effective in preventing and treating cataracts. The present invention uses not active vitamin D but the vitamin D ergocalciferol or cholecalciferol for the purpose of reducing opacity of the lenticular capsule due to hyperplasia and metabolites of the lens epithelium after cataract surgery. The vitamin D, active vitamin D, vitamin K etc. of this invention may be either natural or artificially synthesized compositions or their analogs. Analogs of the vitamin D cholecalciferol include cholecalciferol sulfate (molecular weight 486.7 daltons), while artificially synthesized active vitamin D analogs include alphacalcidol (1alpha-monohydroxyvitamin D), 22-oxacalcitriol (OCT), calcipotriol (MC903), KH1060 and dihydrotachysterol. Tears are amphipathic and viscous. If the vitamin D ophthalmic solution of this invention is mixed in a solution of polysorbate, polyvinyl alcohol, methylcellulose, hyaluronate, chondroitin sulfate, vegetable oil or fat to form viscous eyedrops, the vitamin D will remain on the surface of the eye for a long time, and will be highly effective in preventing and treating eye injuries, dry eye syndrome and ocular diseases. Taking advantage of the fact that D vitamins have a maximum UV absorption curve for harmful UV radiation in the neighborhood of 260 nm, one or more of provitamin D, previtamin D, vitamin D, active vitamin D, vitamin K or an analog of any of these is used as the effective ingredient in the ophthalmic composition or dermatological composition. Effective forms of vitamin D include ergocalciferol or cholecalciferol as well as active forms of vitamin D formed by hydroxylation of the C1 position of the A-ring of the sterol nucleus, side-chain C25 or both C1 and C25. Considering that active vitamin D medicines have been used to treat psoriasis in the past, it is anticipated that the dermatological composition of this invention will be good for the skin. Vitamin K also has a maximum UV absorption spectrum for UV radiation in the neighborhood of 260 nm, and this fact can be exploited in making a dermatological or ophthalmic composition for protecting the eyes and skin from harmful UV radiation. The tissues in the eye which are protected from harmful UV radiation by the use of the ophthalmic composition of this invention are the cornea, conjunctiva, lens or retina. The ophthalmic composition which protects against this harmful UV radiation should preferably be in the form of an eyedrop medication, ointment or contact lenses. The dermatological composition of this invention can also be used on the hair and scalp, and it can be applied as a hair and scalp treatment conditioner or as a hair treatment conditioner. This invention comprises at least one of the fat-soluble vitamins provitamin D, previtamin D, vitamin D, active vitamin D, vitamin K or an analog of one of these mixed in a cosmetic or sunscreen, and applied topically to the skin in order to prevent exposure of the skin to harmful UV in the neighborhood of 260 nm. This invention is a dermatological composition which takes the form of the solution, ointments, creams, lotions, sprays and treatment conditioners which have conventionally been used in cosmetics and sunscreens. Since the use of cosmetics on the skin inhibits the skin's synthesis of vitamin D by UV light, it is also possible to supplement vitamin D through the skin using the dermatological composition containing vitamin D adapted to a cosmetic. When used on the scalp, it also protects the cuticula pili from UV light, regulates the cuticula pili activity, and prevents hair loss. In other words, the use of conventional dermatological compositions interferes with the synthesis of vitamin D in the skin. One way of supplying vitamin D to the skin is through the topical use of the dermatological composition containing the vitamins D ergocalciferol and cholecalciferol of this invention on the skin and hair. The concentration of provitamin D, previtamin D, vitamin D, active vitamin D or vitamin K in the ophthalmic or dermatological composition for protecting against harmful UV radiation of this invention, since it is intended for topical administration, may be about 100 micrograms/ml(g) or less, or at least about 0.01 micrograms/ml(g). Since provitamin D, previtamin D, vitamin D, active vitamin D and vitamin K are not cytotoxic, they should not affect the ocular tissue or epidermal cells if used in a normal mixture. When the ophthalmic composition or dermatological composition of this invention is used, the provitamin D, previtamin D, vitamin D, active vitamin D or vitamin K which covers the eyes or skin absorbs a significant amount of harmful UV radiation, and protects ocular and skin tissue from harmful UV radiation. If conventional vitamin D and active vitamin D preparations are taken orally in large doses, symptoms of vitamin D excess occur. Calcium and phosphates rise in the blood, and there is calcification of the kidneys, arteries, smooth muscles, lungs and other soft tissues. The provitamin D, previtamin D, vitamin D, active vitamin D and vitamin K of the ophthalmic or dermatological compositions of this invention have always been effective in smaller doses, and though some of the vitamin D or vitamin K may be absorbed into the blood through the eyes or skin, the side-effects seen with conventional preparations are unthinkable. The provitamin D, previtamin D, vitamin D, active vitamin D or vitamin K of this invention may be either a natural or artificially synthesized composition, or it may be an analog. Vitamin K analogs which have been developed include the artificially synthesized, water-soluble menadiol diphosphate and menadione hydrogen sulphite salt, and these vitamin K analogs may also be used. In U.S. Pat. No. 4,335,120, Holick et al disclose a way of introducing active vitamin D into the bloodstream through the skin for therapeutic purposes. By contrast, the present invention is a cosmetic or other dermatological composition which uses vitamin D to protect the skin against UV radiation. In U.S. Pat. No. 4,610,978, Dikstein et al disclose active vitamin D as a skin cream for treating the skin. By contrast, the present invention is a cosmetic or other dermatological composition which uses vitamin D to protect the skin against UV radiation. In U.S. Pat. No. 5,254,538, Holick et al disclose a method of treating periodontal disease and ulcerative keratitis and corneal abrasion in ophthalmology with active vitamin D. The present invention contains an ophthalmic or dermatological composition which uses vitamin D to protect the eyes and skin against UV radiation. Based on the discovery that the vitamins D ergocalciferol and cholecalciferol, rather than active vitamin D, are effective in regulating wound healing as it relates to optical transparency and refraction locally in the eye, the inventor arrived at the invention of an ophthalmic composition of the vitamin D ergocalciferol or cholecalciferol. The present invention involves an ophthalmic composition of the vitamin D ergocalciferol or cholecalciferol for purposes such as preventing and treating keratoconjunctival dryness and corneal disease or preventing opacity of the posterior capsule. Without further elaboration, it is believed that one skilled in the art, using the preceding description, can utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative in any way whatsoever, of the remainder of the disclosure. This invention is explained in more detail below using examples of preparations and experiments. PREPARATION 1 One milligram of vitamin D (cholecalciferol, molecular weight 384.6 daltons) was diluted with 10 ml of ethanol (purity 99.9%), and 0.1 ml of the diluted solution was again diluted 100-fold with a polysorbate80 ophthalmic solution (0.5%-Tween80 ophthalmic physiological buffer solution) as the vehicle, to prepare an ophthalmic composition with a vitamin D concentration of 1 microgram/ml. PREPARATION 2 Five milligrams of vitamin D (cholecalciferol) was diluted with 10 ml of ethanol (purity 99.9%), and 0.1 ml of the diluted solution was again diluted 100-fold with an ophthalmic oil base consisting of refined sesame oil, to prepare an ophthalmic composition with a vitamin D concentration of 5 micrograms/ml. PREPARATION 3 Five milligrams of vitamin K2 (menaquinone 4, molecular weight 444.7 daltons) was diluted with 10 ml of ethanol (purity 99.9%), and this diluted solution was again diluted 100-fold with an ophthalmic oil base consisting of refined sesame oil, to prepare an ophthalmic composition with a vitamin K concentration of 5 micrograms/ml for blocking UV radiation. PREPARATION 4 0.5 milligrams of active vitamin D (calcitriol, 1alpha,25-dihydroxyvitamin D) was diluted with 10 ml of ethanol (purity 99.9%), and 0.1 ml of this diluted solution was again diluted 100-fold with polysorbate80 ophthalmic solution (0.5%-Tween80 ophthalmic physiological buffer solution), to prepare an ophthalmic composition with an active vitamin D concentration of 0.5 micrograms/ml which would be a prophylactic and treatment for keratoconjunctival dryness. PREPARATION 5 One hundred milligrams of vitamin D (cholecalciferol) was diluted with 10 ml of ethanol (purity 99.9%), and 1 ml of the diluted solution was again diluted 100-fold with simple hydrophilic petrolatum (3%-cholesterol, 3%-stearyl alcohol, 8%-white wax, 86%-white petrolatum), to prepare a dermatological composition with a vitamin D concentration of 100 micrograms/ml which protects the skin against UV radiation. PREPARATION 6 Ten milligrams of vitamin D (cholecalciferol) was diluted with 10 ml of ethanol (purity 99.9%), and 0.1 ml of the diluted solution was again diluted 100-fold with polysorbate80 ophthalmic solution (0.5%-Tween80 ophthalmic physiological buffer solution) as the vehicle, to prepare an ophthalmic composition with a vitamin D concentration of 10 micrograms/ml. PREPARATION 7 Ten milligrams of vitamin D (cholecalciferol) was diluted with 10 ml of ethanol (purity 99.9%), and 0.1 ml of the diluted solution was again diluted 100-fold with medium-chain fatty acid triglyceride, to prepare an ophthalmic composition with a vitamin D concentration of 10 micrograms/ml. EXPERIMENT 1 The effectiveness and safety of the vitamin D cholecalciferol in the wound healing process following corneal trauma were investigated. Four albino rabbits weighing 2 kg each were used. After instillation anesthesia and injection of an analgesic and anesthetic to the tensor muscle, a trephine 5 mm in diameter was used to make a circular scar in about half a layer of the surface of the right cornea of each rabbit. The corneal epithelium and superficial stroma within the circle were then abraded with a spatula, and the epithelial cells removed. The left eyes were not treated. After surgery, an ophthalmic solution and ointment containing the antibiotic ofloxacin were administered to the right eyes. Two rabbits were put in group A, and the remaining two were put in group B. An ophthalmic composition prepared as in Preparation 1 was administered to group A three times a day at 4-hour intervals beginning on the following day of surgery. About 20 microliters (1-2 drops) was administered each time. An ophthalmic physiological buffer solution without vitamin D was administered to group B in the same way, three times a day at 4-hour intervals. The degree of corneal opacity in all treated eyes was observed after 1 week, 2 weeks and 1 month, using a slitlamp microscope, and evaluated at 6 levels on a scale of 0 (no corneal opacity) to 5 (serious corneal opacity). After one week, the evaluation was 0 for groups A and B. After 2 weeks, a very slight opacity was seen subepithelially in two eyes in group B. In particular, a very slight cloudiness was seen here and there in the area traumatized by the trephine, and this was graded as 1. A very slight subepithelial opacity was seen in one eye in the A group and graded as 1, but there was no opacity in the other eye and it was graded as 0. After one month there was moderate subepithelial opacity in one eye in the B group, which was graded as 3. There was slight cloudiness in the other eye in the B group, which was graded as one. There was slight subepithelial opacity in 1 eye in the A group which was graded as 1, but there was no opacity in the other eye, which was graded as 0. After one month, opacity was visible to the naked eye in the one eye in the B group which was graded as 3, and the area inside the circle was slightly cloudy. EXPERIMENT 2 The effectiveness and safety of the vitamin D cholecalciferol in the wound healing following corneal trauma were investigated. Four Japanese albino rabbits weighing 2 kg each were used. Under anesthesia, an excimer laser (Summit Technology, Inc., U.S.A.) was used to irradiate the central portion of the right corneas. Irradiation was done in phototherapeutic keratectomy (PTK) mode, at energy density 165 mj/cm2, ablation rate 0.25 microns/pulse, 300 shots, ablation zone diameter 4.5 mm. The four irradiated rabbits were divided into 2 groups of 2 rabbits each, which were designated the treatment group and the control group. Antibiotics were administered to the eyes of all rabbits on the day of surgery and the following day. A vitamin D solution (cholecalciferol 10 micrograms/ml) as described under Preparation 7 was administered to the surgically treated eyes of each rabbit in the treatment group, while a base (medium-chain fatty acid triglyceride) without vitamin D was administered to the control group. Twenty microliters each time were administered three times a day for 14 days, beginning 24 hours after laser irradiation. The degree of corneal opacity was evaluated based on corneal findings in the four eyes, which were observed by slitlamp microscopy after dilation with a mydriatic 7 and 15 days after laser irradiation of the corneas. Evaluation was done by scoring the periphery and central area of the irradiated region at five levels on a scale of 0 (no corneal opacity) to 4 (complete opacity). After 7 and 15 days, opacity was observed throughout the irradiated regions of the corneas of the control group. The degree of opacity was high at the periphery of irradiation and low in the central area. Although a circular opacity about 1 mm in width was observed at the periphery of irradiation in the treatment group, the central area was mostly clear. The average scores for the entire irradiated region were 3 in the control group and 1 in the treatment group after 7 days, and 3 in the control group and 1 in the treatment group after 15 days. Therefore, the scores of the treatment group were significantly lower than those of the control group. For purposes of regulating corneal wound healing, the effects of the viscous ophthalmic composition of this invention were better than those obtained using a less viscous, watery base in similar tests. The effects of the vitamin D cholecalciferol in regulating corneal wound healing have also been confirmed by this Experiment 2. In Experiment 2, the rabbits were sacrificed and their eyeballs extracted. A comparative histological study of the corneas revealed that there was less hyperplasia of the epithelial cells on the periphery of irradiation in the treatment group than in the control group. These findings matched those of the slitlamp microscope examination. This shows that administration of the ophthalmic composition of vitamin D of this invention offers the advantages of reducing corneal opacity and corneal refractive error, and making it possible to avoid repeated surgery due to inadequate refractive correction after surgery in laser keratectomy patients. EXPERIMENT 3 The effects of active vitamin D on eyes afflicted with dry eye syndrome was investigated. Six Sprague-Dawley strain rats were used three weeks after birth. All rats were fed vitamin A-deficient diet for four weeks in order to induce a dry eye condition. Beginning in the 5th week, three rats were put in group D and given vitamin A-deficient diet, and the active vitamin D of Preparation 4 for prevention and treatment of keratoconjunctival dryness was administered. The remaining three rats were put in group C (the control group) and given vitamin A-deficient diet, and an ophthalmic composition consisting of 0.5%-polysorbate80 (Tween80) ophthalmic physiological buffer solution without active vitamin D was administered. Administration was done in both eyes three times a day by taking about 20 microliters in a pipette and administering it as 1-2 drops each time. Two weeks after the beginning of instillation, slitlamp microscopy observation with fluorescein sodium staining revealed no superficial punctate keratitis in group D, while in the eyes in group C there were faint stained spots within a circle about 2 mm in diameter in the central portion of the cornea. In this slitlamp microscopy examination, it was found that the inflammation of superficial keratitis was greater in the C group than in the D group. The C group rats were less lively and had less excrement than the D group rats. The experiment was concluded in the fifth week. The results showed that protection and treatment of keratoconjunctival dryness was slightly better in the D group than in the C group, and the cornea and conjunctiva were better protected. EXPERIMENT 4 The effects of UV light on the corneas, eyelids and ocular mucous membranes were investigated. Six Sprague-Dawley strain rats were used. The two rats in the D group were given vitamin D, the two in the Group K were given vitamin K2, and the two in Group C were the control. The vitamin D ophthalmic composition of Preparation 2 was administered to Group D. Group C (the control) received ophthalmic refined sesame oil. Administration was done in both eyes three times a day by taking about 10 microliters in a pipette and administering it as 1 drop each time, beginning one week before UV irradiation. UV irradiation was done using a convention UV light sterilizer (15W discharge tube, peak UV wavelength 254 nm), and the rats were kept in this sterilizer. On the second day in the sterilizer, slitlamp microscopy examination revealed mild superficial punctate keratitis in all eyes in Group C. Extremely mild superficial punctate keratitis was seen in all eyes in Groups D and K. On the third day in the sterilizer, there was serious eyelid and conjunctival edema and superficial punctate keratitis in all eyes in Group C, while mild conjunctival edema and superficial punctate keratitis were seen in all eyes in Groups D and K. The experiment was terminated open observation of serious eyelid and conjunctival edema and superficial punctate keratitis in the C group, and slitlamp microscopic observation with fluorescein staining was not performed. The results showed that there was clearly much better protection against UV radiation in the D and K groups than in the C group, with ocular tissues such as the eyelids, conjunctiva and cornea being protected. EXPERIMENT 5 The degree of lenticular capsule opacity after cataract surgery was investigated using rabbits. Four Japanese albino rabbits weighing 2 kg each were used. The right eyes of the rabbits were dilated with a mydriatic in preparation for surgery. After instillation anesthesia and injection of an analgesic and anesthetic to the tensor muscle, the corneas of the rabbits' right eyes were punctured, the anterior chamber was filled with a viscoelastic material, and anterior capsulotomy was performed to ablate a capsule about 5 mm in diameter and as round as possible. Next, an incision 3.5 mm in width was made at an angle of about 45 degrees to the corneal tangent to create a flap in the cornea about 2 mm from the corneoscleral border. Phacoemulsification was performed, the lens nucleus and cortex were removed by aspiration, the anterior chamber and the inside of the capsule were irrigated with perfusate, and surgery was terminated without suturing of the corneal incision. In an effort to prevent fibrin precipitation and a transitory rise in intraocular pressure immediately after surgery, antithrombin III was mixed to be 50 IU/ml with the viscoelastic material and perfusate used during surgery. Antibacterial ointment and eyedrops were administered to the conjunctivas and corneas of the surgically treated eyes after surgery. The ophthalmic composition of Preparation 6 was administered to the eyes of 2 rabbits which were assigned at random to the treatment group, while the other 2 rabbits were assigned to the control group and received ophthalmic composition consisting of 0.5%-polysorbate80 (Tween80) ophthalmic physiological buffer solution without vitamin D. Administration was done by taking about 20 microliters in a pipette and administering it in one dose three times a day to the surgically treated eyes. The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples. Antibiotics were administered three times a day and mydriatics once a day to the surgically treated eyes, each for a period of three days after surgery. Slitlamp microscopy of surgically treated eyes dilated with mydriatics two weeks after surgery revealed bands of cloudiness in all eyes on the periphery of the torn anterior capsule. The degree of cloudiness in the treatment group was about half that in the control group, and the bands were significantly narrower in the treatment group. The lenticular capsule in the pupillary zone was also more transparent in the treatment group. Strong cloudiness of the unattached areas of the anterior and posterior capsule was observed especially in the control group. In one of the rabbits in the control group, the incised posterior surface of the cornea adhered to the anterior surface of the iris, and the pupil was deformed. The corneal wounds were more transparent in all animals in the treatment group than in the control group, and there was less scarring. When the rabbits were anesthetized and scarring was investigated by measuring astigmatism within an area 3 mm in diameter from the center of the cornea using a keratoscope, astigmatism was an average of 1.5 diopters in the treatment group and 2.5 diopters in the control group. These corneal and capsular findings indicate that the vitamin D cholecalciferol prevents cloudiness of the cornea and lenticular capsule and refraction error of the cornea when used topically in the eye. In Experiments 1-5, the inventor observed no side-effects such as corneal opacity caused by calcium adsorption on the cornea, conjunctival congestion, fibrin precipitation in the interior chamber or endophthalmitis which might have been caused by vitamin D or vitamin K. It has been confirmed that topical ophthalmic administration of vitamin D according to this invention regulates the activity and metabolism of activated corneal epithelium, keratocytes and epithelium lentis cells during the process of wound healing, and suppresses excess metabolite production by such cells. Moreover, it was suggested that by application of the ophthalmic composition of this invention, vitamin D on the eyelids, conjunctiva and cornea and in corneal tissue significantly protects these tissues against harmful UV radiation. In addition, the fact that it protects eyelids and conjunctiva against UV confirms that it can be a dermatological composition. The test results described above suggest that the ophthalmic or dermatological compositions of this invention would also be both safe and effective for humans. Protection and treatment of keratoconjunctival dryness of the eye can be achieved by topical ophthalmic use of either the vitamin D or active vitamin D of this invention. Moreover, better results are achieved with the ophthalmic composition if it is mixed with a solution similar to tears, such as a viscous solution. Topical ophthalmic administration of the vitamin D composition of this invention can be applied to wound healing after ocular surgery. It is possible to prevent opacity and refractive error of the cornea and protect against harmful UV radiation by application of the vitamin D composition of this invention after keratotomy or keratectomy, thus preventing decreased visual acuity. It is also possible to avoid the side effects that have been a problem in the past with corticosteroid eyedrops administered after corneal surgery or in cases of corneal disease. The topical ophthalmic application of the vitamin D of this invention is highly effective for ophthalmic patients whose vitamin D intake is insufficient, or who suffer from impaired kidney or liver function. Since the effects of topical application of the vitamin D of this invention to the cornea are dependent on the activity of the keratocytes and differentiated fibroblasts, there will be little change in the invention's effectiveness in regulating wound healing of ocular tissue even if it contains an excessive concentration of the vitamin D ergocalciferol or cholecalciferol. In other words, in contrast to active vitamin D, the effectiveness of the vitamin D cholecalciferol in regulating corneal cell hyperplasia and metabolite production in injured corneas was not reduced even at relatively high concentrations. In contrast to active vitamin D, it is known that the vitamins D ergocalciferol and cholecalciferol are safe and do not cause the well known side-effect hypercalcemia. Moreover, topical administration of the vitamin D of this invention to the anterior segment does not pose the risk of vitamin D excess, which can occur as a result of excess vitamin D intake. The vitamin D of this invention can be administered safely to the anterior segment because vitamin D has no cytotoxicity. The vitamins D ergocalciferol and cholecalciferol should not exhibit vitamin D toxicity even when used with other medicines. By protecting the eyes against harmful UV radiation, the ophthalmic composition of vitamin D of this invention can prevent corneal diseases such as photokeratitis, corneal ulceration and corneal dystrophy which are caused by UV radiation. Moreover, it is possible to reduce opacity of the lenticular capsule after cataract surgery by using an ophthalmic composition of the vitamin D ergocalciferol or cholecalciferol of this invention. Topical use of either provitamin D, previtamin D, vitamin D, active vitamin D, vitamin K or an analog of one of these in this invention on the skin can protect the skin from harmful UV light. Moreover, since it can also be applied as an ophthalmic composition, the provitamin D, previtamin D, vitamin D, active vitamin D, vitamin K and analogs of these should cause no side-effects even if they enter the eyes.

An ophthalmic composition, containing ergocalciferol or cholecalciferol, i.e., an inactive vitamin D, as the active ingredient, for treating and conditioning damaged tissue of the region of the eye. An ophthalmic composition for preventing and treating disturbed metabolism in eye tissues, such as "dry eye", including a vitamin D or an active vitamin D as the active ingredient. An ophthalmic composition or a dermatological composition for protecting the skin or eyes from harmful ultraviolet radiation including a vitamin D or a vitamin K as the active ingredient. The ophthalmic composition normalizes the transparency or refraction of the eyeballs when administered to the region of the eye, and contributes to the amendment, healing or prevention of symptoms due to disturbed metabolism in eye tissue. The dermatological composition protects the skin and scalp from harmful ultraviolet radiation. It is possible to supply vitamin D to the skin by applying the vitamin D-containing dermatological composition via a cosmetic.

This application is a Continuation-In-Part Application of PCT International Application No. PCT/JP03/016960 filed on Dec. 26, 2003, which designated the United States. FIELD OF THE INVENTION The present invention relates to a substrate supporting structure and a plasma processing device. The term “semiconductor processing” used herein implies various processes to manufacture a semiconductor device and/or a structure including wiring, electrodes, and the like connected to the semiconductor device on a substrate to be processed, by forming a semiconductor layer, an insulating layer, a conductor layer, and the like, after a predetermined pattern, on the substrate to be processed, e.g., a semiconductor wafer, an LCD (Liquid Crystal Display) or an FPD (Flat Panel Display). BACKGROUND OF THE INVENTION With the recent trend of highly integrated and high-performance semiconductor device, improvement in productivity of manufacturing the semiconductor is very essential to realize cost reduction. As for a method for improving the productivity, increasing a diameter of a semiconductor substrate may be enumerated. Conventionally, a 200 mm substrate has been used as a semiconductor substrate (wafer), but, now, a 300 mm substrate is mainly used. If a semiconductor device is fabricated by using a 300 mm substrate of a large diameter, the number of semiconductor devices, which can be produced by using one sheet of substrate, is increased, thereby improving the productivity. In case of using a 300 mm substrate, the conventional semiconductor device for processing a 200 mm substrate should be replaced with a device capable of processing a 300 mm substrate. In this case, a substrate supporting structure for supporting the substrate becomes scaled up, so that the semiconductor processing device such as plasma processing device or the like has to be also large-scaled. Thus, the footprint of the semiconductor processing device is increased, and the number of devices, which can be disposed in a semiconductor production factory, is accordingly decreased to thereby lower the productivity of the semiconductor device. Further, if components for a 200 mm substrate are scaled up to be used for a 300 mm substrate while employing the conventional substrate supporting structure as it is, a substantial cost increase is incurred. SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a substrate supporting structure and a plasma processing device for semiconductor processing capable of realizing a scaling-down for miniaturization and reducing cost. It is another object of the present invention to provide a plasma processing device capable of increasing at least inter-surface uniformity of a film formed on a substrate to be processed. In accordance with the one aspect of the present invention, there is provided a substrate supporting structure for semiconductor processing including: a mounting table for mounting thereon a substrate to be processed; and a support part, disposed to be downwardly extended below the mounting table, for supporting the mounting table, wherein the mounting table contains an electrode part; a first insulating layer for covering a periphery of the electrode part; a second insulating layer for covering a bottom surface of the electrode part; and a first conducting layer covering the first and second insulating layers, wherein the support part contains a conductive transmission path for supplying a power to the electrode part; a third insulating layer for covering a periphery of the transmission path; and a second conducting layer for covering a periphery of the third insulating layer, and wherein the electrode part of the mounting table, the first and the second insulating layers and the first conducting layer are coaxially configured; the conductive transmission path of the support part, the third insulating layer and the second conducting layer are coaxially configured; the electrode part and the conductive transmission path are integrally formed; and the first and the second conducting layers are electrically connected to each other, and wherein a first channel for supplying a heat exchange medium into the electrode part is formed; and a second channel communicated with the first channel is formed in the conductive transmission path. In accordance with another aspect of the present invention, there is provided a plasma processing device, including: an airtight processing chamber for accommodating therein a substrate to be processed; a gas supply unit for supplying a processing gas into the processing chamber; a gas pumping unit for exhausting the processing chamber; a mounting table, disposed in the processing chamber, for mounting thereon the substrate; and a support part, disposed to be downwardly extended below the mounting table, for supporting the mounting table, wherein the mounting table contains an electrode part; a first insulating layer for covering a periphery of the electrode part; a second insulating layer for covering a bottom surface of the electrode part; and a first conducting layer covering the first and second insulating layers, wherein the support part contains a conductive transmission path for supplying a power to the electrode part; a third insulating layer for covering a periphery of the transmission path; and a second conducting layer for covering a periphery of the third insulating layer, and wherein the electrode part of the mounting table, the first and the second insulating layers and the first conducting layer are coaxially configured; the conductive transmission path of the support part, the third insulating layer and the second conducting layer are coaxially configured; the electrode part and the conductive transmission path are integrally formed; and the first and the second conducting layers are electrically connected to each other, and wherein a first channel for supplying a heat exchange medium into the electrode part is formed, and a second channel communicated with the first channel is formed in the conductive transmission path. In accordance with still another aspect of the present invention, there is provided a plasma processing device, including: an airtight processing chamber for accommodating therein a substrate to be processed; a gas supply unit for supplying a processing gas into the processing chamber; a gas pumping unit for exhausting the processing chamber; a mounting table, disposed in the processing chamber, for mounting thereon the substrate; and a conductive extension member for surrounding the substrate mounted on the mounting table, the extension member having a surface in parallel with that of the substrate, wherein the mounting table contains an electrode part to which a power is applied; a pedestal insulation layer for covering a bottom surface and a side of the electrode part; and a pedestal conduction layer, electrically connected to the support conduction layer, for covering at least a part of the bottom surface and the side of the pedestal insulation layer; and the electrode part, the pedestal insulation layer and the pedestal conduction layer are coaxially configured, and wherein the extension member is disposed on the pedestal insulation layer while being electrically insulated from the electrode part and the pedestal conduction layer; in the side of the pedestal insulation layer, a top end of the pedestal conduction layer is disposed to be placed below a bottom portion of the electrode part; and impedance between the extension member and the pedestal conduction layer is set to be greater than impedance between the electrode part and the pedestal conduction layer. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which: FIG. 1 offers a configuration view showing a plasma processing device containing a substrate supporting structure for semiconductor processing in accordance with a first embodiment of the present invention; FIG. 2 describes a cross sectional view showing a magnified substrate supporting structure shown in FIG. 1 ; FIG. 3 sets forth a cross sectional view showing a part of the substrate supporting structure shown in FIG. 1 ; FIG. 4 presents a cross sectional view showing a magnified X part shown in FIG. 3 ; FIG. 5 provides a cross sectional view showing a magnified Z part shown in FIG. 4 ; FIG. 6 describes a transversal cross sectional view taken along Y-Y line shown in FIG. 2 ; FIGS. 7A and 7B present partial cross sectional views showing a substrate supporting structure in accordance with a modified example of the first embodiment; FIG. 8 is a graph showing a measurement result of self-bias potential in case of applying a high frequency power to a mounting table; FIG. 9 presents a table showing process conditions; FIG. 10 describes a schematic configuration cross sectional view showing a schematic configuration of a plasma processing device; FIG. 11 offers a schematic configuration view showing a configuration of a main part of the plasma processing device shown in FIG. 10 ; FIG. 12 presents a magnified partial cross sectional view schematically showing a configuration of an outer periphery of the mounting table; FIGS. 13A and 13B are circuit diagrams showing equivalent circuits for a plasma in the plasma processing device and a lower electrode; and FIG. 14 shows a magnified partial cross sectional view of the plasma processing device in accordance with a modified example of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following discussion, identical reference numerals will be assigned for corresponding parts having substantially same functions and configurations, and redundant explanations will be omitted unless necessary. First Embodiment FIG. 1 is a configuration view showing a plasma processing device including a substrate supporting structure for semiconductor processing in accordance with a first embodiment of the present invention. A plasma processing device 10 is configured to perform a sputter etching or a reactive etching on a silicon oxide film, a metal oxide film or the like, which is formed on a semiconductor wafer as a substrate to be processed. As shown in FIG. 1 , the plasma processing device 10 includes a processing chamber 20 for receiving thereinto a substrate W to be processed. To the processing chamber 20 , a gas supply unit 30 for supplying a processing gas thereinto is coupled. An excitation mechanism 40 for converting the processing gas into a plasma is disposed at an outer upper side of the processing chamber 20 . A mounting table 51 of a substrate supporting structure 50 for supporting the substrate W to be processed is disposed at an inner lower side of the processing chamber 20 . The processing chamber 20 is formed by combining a conductive cylindrical lower side vessel 201 with an insulating cylindrical upper vessel or bell jar 401 . In a center of a bottom portion of the lower side vessel 201 , there is formed an opening, to which a downwardly protruded cylindrical exhaust chamber 202 is airtightly coupled. The exhaust chamber 202 has a planar outline, which is sufficiently small, compared to the processing chamber 20 ; and it is concentrically placed with the processing chamber 20 . At a bottom portion of the exhaust chamber 202 , a support part 52 of the substrate supporting structure 50 is attached. The support part 52 of the substrate supporting structure 50 is fixed to the bottom portion of the exhaust chamber 202 by using an attachment ring 221 , screw reception rings 220 and 222 , clamping screws 219 and the like. Detailed descriptions thereof will be explained later with reference to FIG. 2 . The support part 52 is vertically elevated at a center of the exhaust chamber 202 , to thereby be coupled to the mounting table 51 through the opening of the bottom portion of the lower side vessel 201 . An opening 218 is formed in a sidewall of the exhaust chamber 202 , and a gas pumping unit 204 , e.g., a turbo molecular pump or the like, is connected thereto through a gas exhaust line 203 . In case when performing an etching, particularly, a sputter etching, a space needs to be kept under a low pressure. For example, the processing space needs to be maintained at a low pressure in the range of 0.0133˜1.33 Pa, and preferably, 0.0133˜0.133 Pa, by using the gas pumping unit 204 such as a turbo molecular pump or the like. An airtight processing space 402 in the processing chamber 20 is vacuum-exhausted by the gas pumping unit 204 through an exhaust space 202 A of the exhaust chamber 202 , which surrounds the support part 52 . Since the processing space 402 is exhausted through the exhaust space 202 A concentrically disposed therebelow, the processing space 402 can be uniformly exhausted compared to the case where the processing space 402 is exhausted through the side of the processing chamber 20 . Namely, the processing gas can be uniformly exhausted with respect to the substrate W as a center. Thus, the pressure in the processing space 402 becomes uniform, thereby producing the plasma uniformly. Hence, uniformity in etching rate while performing an etching on the substrate to be processed is enhanced. At the bottom portion of the exhaust chamber 202 , there is disposed a shielding member or a shield cover 205 made of metal, e.g., aluminum, alloy thereof, that is grounded. An RF introducing component 206 for introducing an RF power into the mounting table 51 of the substrate supporting structure 50 is disposed in the shield cover 205 . The RF introducing component 206 is connected to a high frequency (RF) power supply 210 for a bias-applied through a matching unit 209 . The mounting table 51 of the substrate supporting structure 50 has an electrode part 501 of a circular plate shape; and at the same time, the support part 52 of a columnar shape has a conductive RF transmission path 502 . The electrode part 501 and the transmission path 502 are formed as a unit by using a conductive material such as Al, alloy of Al, or the like, which are electrically connected to each other. A lower portion of the transmission path 502 is electrically connected to the RF introducing component 206 . Thus, the RF power is supplied to the electrode part 501 of the mounting table 51 from the RF power supply 210 though the transmission path 502 , and therefore, a bias voltage is applied to the substrate W to be processed. The shield cover 205 shields the RF to prevent any leakage thereof to the outside. In the electrode part 501 of the mounting table 51 , there is formed a heat exchange medium chamber 507 (herein, a temperature control space, formed as a flow path) for accommodating therein a heat exchange medium, e.g., an insulating coolant fluid, for controlling temperature of the mounting table 51 . Meanwhile, in the transmission path 502 of the support part 52 , an introduction channel 215 and a discharge channel 216 are formed to supply the heat exchange medium into the temperature control space 507 and discharge it therefrom. At a lower portion of the support part 52 , an insulation component 207 made of an insulating material such as ceramic, e.g., Al 2 O 3 , resin or the like, is disposed. The introduction channel 215 and the discharge channel 216 pass through the insulation component 207 to be coupled to metallic connection tubes 213 and 214 , respectively, that are attached to the insulation component 207 . Thus, the connection tubes 213 and 214 are electrically insulated from the RF transmission path 502 by the insulate component 207 . Peripheries of the insulation component 207 and the lower portion of the transmission path 502 are covered by a thermal insulator 217 . The connection tubes 213 and 214 are coupled to a circulation unit (CU), e.g., a chiller, which functions to control the temperature. The heat exchange medium is circulated from the circulation unit (CU) to the temperature control space 507 through the introduction channel 215 and the discharge channel 216 , so that the temperature of the mounting table 51 is maintained at a predetermined temperature. In a side of the lower side vessel 201 , there is formed a transfer port for substrate W, in which a gate valve 208 is disposed. While the gate valve 208 is opened, the substrate W to be processed can be loaded into the processing chamber 20 and unloaded therefrom. At that time, lift pins (e.g., three) of an elevation mechanism 211 are operated to assist transportation of the substrate W from the mounting table 51 . A gas supply unit 30 includes an Ar gas supply source 305 connected to the gas supply line 311 through an Ar gas line 301 , and an H 2 gas supply source 310 connected thereto through an H 2 gas line 306 . Valves 302 and 304 and a mass flow controller 303 are disposed in the Ar gas line 301 . If the valves 302 and 304 are opened, Ar gas is supplied to the gas supply line 311 , wherein the flow rate of the gas to be supplied is controlled by the mass flow controller 303 . In the same manner, valves 307 and 309 and a mass flow controller 308 are disposed in the H 2 gas line 306 . If the valves 307 and 309 are opened, H 2 gas is supplied to the gas supply line 311 , wherein the flow rate of the gas to be supplied is controlled by the mass flow controller 308 . The gas supply line 311 , through which Ar gas and H 2 gas are supplied, is connected to a gas supply ring 212 , which is annularly disposed on the lower side vessel 201 along the edge thereof. A gas supply groove 212 B is annularly formed in the gas supply ring 212 to discharge Ar gas or H 2 gas over the entire periphery of the gas supply ring 212 . Ar gas or H 2 gas is supplied towards the center of the processing space 402 through gas holes 212 A communicating with the gas supply groove 212 B. Ar gas or H 2 gas supplied to the processing space 402 turns into a plasma by an excitation mechanism 40 explained hereinafter. An upper vessel, i.e., a bell jar 401 , is made of a dome shaped insulating material, e.g., quartz, ceramic (Al 2 O 3 , AlN) or the like. An antenna coil 404 of the excitation mechanism 40 is wound around the periphery of the bell jar 401 . The coil 404 is coupled to an RF power supply 403 through a matching unit 405 . The RF power supply 403 generates an RF power having a frequency in the range of, e.g., 450 kHz˜60 MHz (preferably, 450 kHz˜13.56 MHz). If the RF power is supplied to the coil 404 from the RF power supply 403 , an induced magnetic field is formed in the processing space 402 . By the induced magnetic field, gas such as Ar, H 2 or the like, supplied into the processing space 402 , turns into a plasma. Such plasma is referred to as an inductively coupled plasma (ICP). With the plasma excited as above, a plasma processing, e.g., an etching, is performed on the substrate disposed on the mounting table 51 . In the plasma processing device 10 , a diameter Da of the columnar support part 52 of the substrate supporting structure 50 can be made small. Thus, a diameter Db of the exhaust chamber 202 can be made small and the total plasma processing device 10 becomes small, to thereby reduce foot print (occupation area). Further, members such as the gas pumping unit 204 , e.g., turbo molecular pump, a pressure control valve (not shown) and the like are coupled through the gas exhaust line 203 to a gas exhaust port 218 formed on the sidewall of the exhaust chamber 202 (by using the space efficiently). Therefore, the gas exhaust line 203 or the gas pumping unit 204 can be disposed within the outline of the lower side vessel 201 or the excitation mechanism 40 (inside the range shown as the diameter Dc in FIG. 1 ). FIG. 2 is a cross sectional view showing a magnified substrate supporting structure 50 shown in FIG. 1 . Hereinafter, the substrate supporting structure 50 will be discussed with reference to FIG. 2 . As described above, the substrate supporting structure 50 includes the circular plate shaped mounting table 51 and the columnar support part 52 concentrically disposed therebelow. The mounting table 51 contains the aforementioned electrode part 501 to which the RF power is applied. The side of the electrode part 501 is covered with a ring block 508 made of a dielectric material such as quartz or the like. A bottom surface of the electrode part 501 is covered with a plate block 509 made of a dielectric material, e.g., quartz, and having in the center thereof holes, through which the transmission path 502 passes. A pedestal insulation layer is formed of the ring block 508 and the plate block 509 . The bottom surfaces and sides of the insulation layers 508 and 509 are also coated with a pedestal cover (pedestal conduction layer) 514 made of a conductive material such as Al, Ti or the like. The electrode part 501 , the insulation layers 508 and 509 and the conduction layer 514 are coaxially configured. Meanwhile, the support part 52 includes the aforementioned conductive transmission path 502 for introducing the RF power. The transmission path 502 is coated with an insulator (support insulation layer) 513 made of a dielectric material such as PTFE (polytetrafluoroethylene) or the like. The insulator 513 is also coated with a support cover (support conduction layer) 515 made of a conductive material such as Al, Ti or the like, which is grounded. The transmission path 502 , the support insulation layer 513 and the support conduction layer 514 are coaxially configured. The electrode part 501 and the transmission path 502 are molded as a unit by using a conductive material such as Al, alloy thereof or the like, so that these are electrically connected to each other. The ring block and the plate block (pedestal insulation layers) 508 and 509 and the insulator (support insulation layer) 513 are formed individually. The pedestal cover (pedestal conduction layer) 514 and the support cover (support conduction layer) 515 are molded individually. However, they are unified by welding, and at the same time, electrically connected to each other. As described above, the temperature control space 507 accommodating therein the heat exchange medium (fluid) for uniformly maintaining the substrate to be processed at a predetermined temperature is formed in the electrode part 501 . In the temperature control space 507 , the introduction channel 505 and the discharge channel 506 , which are formed in the transmission path 502 , are connected to each other; and a flow path, through which the heat exchange medium flows between the introduction channel 505 and the discharge channel 506 , is formed. FIG. 3 is a cross sectional view showing a part of the substrate supporting structure shown in FIG. 1 , which describes a cross section substantially normal to the cross section shown in FIG. 2 . A dielectric layer 503 made of a dielectric material, e.g., alumina (Al 2 O 3 ) or the like, is disposed on a top surface (and a side) of the electrode part 501 , with which the substrate W makes a contact. An electrode 504 is inserted into the dielectric layer 503 , disposed on the top surface, to form an electrostatic chuck together with the dielectric layer 503 . The electrode 504 is connected to a DC power supply (not shown) disposed at the outside of the processing chamber 20 through a wiring 516 , which extends through the transmission path 502 while being insulated. If a voltage is applied to the electrode 504 , an electrostatic polarization is generated at the dielectric layer 502 below the substrate W such that the substrate W is electrostatically adsorbed. The dielectric layer 503 is formed by, e.g., ceramic spraying or the like. Alternatively, the dielectric layer 503 may be formed by using a method wherein a ceramic of sintered body is formed in a thin film to be jointed. Further, the dielectric layer 503 may be formed as a dielectric film such as aluminum nitride (AlN), SiC, BN or the like, without using alumina. As described above, the substrate supporting structure 50 is coaxially configured so that mushroom shaped (T-shaped) conductive cores 501 and 502 connected to the RF power supply 210 for a bias are coated with the insulation layers (dielectric layers) 508 , 509 and 513 , and also, coated with conduction layers 514 and 515 that are grounded. By such a configuration, loss of the RF power is reduced; efficiency is improved; and the bias can be stably applied to the substrate to be processed. In the first embodiment, PTFE is used as the support insulation layer (insulator) 513 . The reason is that PTFE has a low permittivity of about 2 and the loss of the RF power is reduced. That is, it is preferable that a low dielectric constant material is used for the support insulation layer 513 , taking the efficiency of RF power into consideration. In the same manner, it is preferable that pedestal insulation layers (ring block and plate block) 508 and 509 are formed by using a low dielectric constant material to reduce the loss in the RF power. However, followings should be noted. In a region where the insulation layers (dielectric layers) 508 , 509 and 513 of the substrate supporting structure 50 are disposed, sealing members 511 and 512 are disposed in the plated block 509 to airtightly separate the mounting table 51 side from the support part 52 side. Namely, the pedestal insulation layers 508 and 509 are placed in a space communicating with the processing space 402 where the plasma is generated in the depressurized state. For the same reason, it is not preferable to use as a material for the pedestal insulation layers 508 and 509 a medium which releases lots of gas. Further, the insulation layers 508 and 509 are greatly influenced by any temperature variation such as a rise or a fall in the temperature due to the generation of plasma. PTFE is porous microscopically compared to a dense material such as quartz or the like, and releases lots of gas in the depressurized state. Thus, it is not preferable to use PTFE in a vacuum vessel. Further, it is problematic that PTFE deforms or has no plasma resistance, to thereby tend to be etched. Accordingly, as for the pedestal insulation layers 508 and 509 , it is preferable to employ such a material that hardly releases any gas in a depressurized vessel and is resistant to a temperature hysteresis, and more preferably, to employ a low dielectric constant material as possible. As for a material satisfying these requirements mentioned above, quartz may be enumerated, and alternatively, e.g., a resin material or the like may be used. Namely, it is preferable to use quartz for the insulation layers 508 and 509 , and PTFE for the support insulation layer 513 . A focus ring 510 made of quartz or the like is disposed on the ring block 508 and the top surface (on which the substrate W is mounted) of the peripheral portion of the electrode part 501 . The focus ring 510 focuses the plasma on a wafer side in the processing chamber, to thereby make the plasma uniform. Further, the focus ring 510 prevents the ring block 508 and the insulating layer 503 from being damaged due to the plasma. As mentioned above, the introduction channel 505 and the discharge channel 506 for supplying the heat exchange medium to the electrode 501 and discharging it therefrom, respectively, are formed in the transmission path 502 . Hence, as described below, the configuration of the substrate supporting structure 50 is simplified, so that the number of components is reduced, and at the same time, scale-down can be realized. In the conventional substrate supporting structure, the RF introduction path for applying a bias to the mounting table, and the channel for introducing the heat exchange medium into the mounting table or discharging it therefrom are formed individually. Therefore, there is required a space below the mounting table, where respective components are to be disposed. Further, components of the RF introduction path and the heat exchange medium path are needed, respectively, and the number of components is large to thereby make the configuration complicated. Still further, since the size of the entire mounting table should be large, a volume to be cooled is increased, and thus, resulting in deterioration of the cooling efficiency. In the substrate supporting structure 50 in accordance with the first embodiment, the introduction channel 505 and the discharging channel 506 are formed in the transmission path 502 , so that the space for disposing the RF introduction path can be commonly shared for the heat exchange medium path. Accordingly, it is possible to reduce the number of components thereof to thereby simplify the configuration and make the space small, which in turn makes it possible to realize the scaling-down of the substrate supporting structure. For example, as shown in FIG. 2 , it is possible to make the diameter Da of the support part 52 small, wherein the support part 52 contains the transmission path 502 , the introduction channel 505 and the discharging channel 506 . As a result, it is possible to make the diameter Db of the exhaust chamber 202 small, wherein the exhaust chamber 202 contains the support cover 515 , and thus, realizing the scaling-down of the substrate supporting structure 50 . As for the heat exchange medium, an insulating fluid, e.g., fluorine based fluid (galden) or the like, may be used, since an RF current is applied to the electrode part 501 . Thus, the substrate to be processed is cooled through the mounting table 51 while securing insulation, so that the temperature of the substrate W to be processed can be maintained constant. The substrate supporting structure 50 is fixed to the exhaust chamber 202 by using an attachment ring 221 , ring shaped screw reception rings 220 and 222 , and clamping screws 219 . The attachment ring 221 is of a substantially circular plate shape having in the center thereof a hole, through which the transmission path 502 passes. The attachment ring 221 is fixed to the transmission path 502 by a screw (not shown). The insulating screw reception ring 220 and metallic screw reception ring 222 are disposed between the attachment ring 221 and the support cover 515 such that they apply upward pressure to the support cover 515 by using the clamping screws 219 , which are screwed into screw holes formed in the attachment ring 221 . By clamping power of the clamping screws 219 , the transmission path 502 of the substrate supporting structure 50 is extended downward, i.e., towards the shield cover 205 . Therefore, the transmission path 502 and the electrode part 501 , as a unit, are pressurized to be adhered closely to the plate block 509 , and the plate block 509 is pressurized to be adhered closely to the cover 514 . As a result, the processing space 402 can be kept airtightly by the sealing ring 511 inserted between the electrode part 501 and the plate block 509 and the sealing ring 512 inserted between the plate block 509 and the pedestal cover 514 . As mentioned above, it is possible to apply weight load needed for airtight sealing to the sealing rings 511 and 512 without using a metal screw. Hence, the processing space 402 can be assured to be airtightly kept in a state where there is no metal contamination source present in the processing space 402 where the plasma is excited. Back to FIG. 3 again, it describes a cross section substantially normal to the cross section shown in FIG. 2 . As illustrated in FIG. 3 , in the transmission path 502 , there is formed a gas flow passage 517 for introducing a gas, that transfers heat at a high rate between the surface of the dielectric layer 503 and the substrate W to be processed. During the plasma processing, the heat transfer gas is supplied to improve the thermal conductivity between the mounting table 51 and the substrate W to be processed, thereby efficiently cooling the substrate W to be processed. Further, as described above, the wiring 516 is disposed in the transmission path 502 to be extended therein while being insulated and is connected to a DC power supply (not shown) disposed outside the processing chamber 20 . The substrate W is electrostatically adsorbed by applying a voltage to the electrode 504 of the electrostatic chuck disposed on the mounting table 51 through the wiring 516 . FIG. 4 is a cross sectional view showing a magnified X part shown in FIG. 3 . As shown in FIG. 4 , the gas flow passage 517 communicates with a plurality of grooves 517 A formed on the surface of the mounting table 51 . The heat transfer gas, e.g., Ar, He or the like, is introduced into the grooves 517 A through the gas flow passage 517 . The electrode 504 of the electrostatic chuck is made of metal, e.g., W or the like. The electrode 504 is embedded between the upper and lower dielectric layers 503 and 518 made of, e.g., a thermally sprayed film of Al 2 O 3 or the like. FIG. 5 is a cross sectional view showing a magnified Z part shown in FIG. 4 . As illustrated in FIG. 5 , the wiring 516 is made of a metal, e.g., Ti or the like. The wiring 516 is introduced into an insertion hole 501 a of a diameter La which is formed on the electrode part 501 . A ring 501 b made of Al is disposed in the insertion hole 501 a by, e.g., beam welding, and the wiring 516 is attached to a hole formed in the ring 501 b. The wiring 516 has a bar-shaped wiring portion 516 a . On the bar-shaped wiring portion 516 a , there is formed a block-shaped step portion 516 b having a diameter larger than that of the wiring portion 516 a . On the step portion 516 b , there is formed a block-shaped step portion 516 c having a diameter smaller than that of the step portion 516 b . Further, on the step portion 516 c , there is formed a block-shaped step portion 516 d having a diameter smaller than that of the step portion 516 c . At sidewalls of the step portions 516 b , 516 c and 516 d , and parts of the step portions 516 b and 516 c which face the electrode 504 , an insulating film 516 i of thickness of 500 μm is formed by, e.g., Al 2 O 3 thermal spraying. In case of applying a DC voltage to the electrode 504 , the DC voltage introduced to the wiring 516 is applied through the step portion 516 d that is making a contact with the electrode 504 . The space of the insertion hole 501 a between the wiring 516 and the electrode part 501 is filled with insulating layers 516 f and 516 e made of, e.g., an insulating resin, so that the wiring 516 is isolated from the electrode part 501 . The insulating layers 516 f and 516 e and the wiring 516 are fixed to the electrode part 501 by using, e.g., an epoxy-based adhesive. FIG. 6 is a transversal cross sectional view taken along Y-Y line indicated in FIG. 2 . As illustrated in FIG. 6 , the introduction channel 505 and the discharging channel 506 are formed in the transmission path 502 . The introduction channel 505 and the discharging channel 506 are surrounded by thermal insulators 505 A and 506 A, e.g., a thermally insulating tube, to increase thermal insulating effect between the heat exchange medium and the transmission path 502 . Preferably, the thermal insulators 505 A and 506 A may be made of a material having low thermal conductivity, e.g., a fluorine based resin such as Teflon, Vespel or the like. The reason is as follows. If the plasma processing is performed on the substrate to be processed in the processing chamber, heat is generated from the plasma. Hence, the heat exchange medium of low temperature, which is supplied into the temperature control space 507 through the introduction channel 505 , is heated to a high temperature and will be discharged through the discharge channel 506 . At this time, if heat is exchanged between the introduction channel 505 and the discharge channel 506 in the transmission path 502 , cooling efficiency of the electrode part 501 will be deteriorated. If the introduction channel 505 and the discharge channel 506 are surrounded by the thermal insulators 505 A and 506 A, the heat from the discharge channel 506 is prevented from being transferred to the introduction channel 505 , thereby efficiently cooling the substrate W to be processed. As described above, the introduction channel 505 , the discharge channel 506 , the gas flow passage 517 and the DC voltage introduction wiring 506 are all disposed within the transmission path 502 . Therefore, the substrate supporting structure becomes small and the number of components is reduced, thereby simplifying the structure and realizing the production cost reduction. The outline of a method for processing the substrate W is as follows. First, the substrate W is supported by the substrate supporting structure 50 . Subsequently, a processing gas is supplied into the processing space formed in the processing chamber 20 from the gas supply unit 30 . Further, the processing gas turns into a plasma by the excitation mechanism 40 to perform a plasma processing on the substrate W. Specifically, first, the gate valve for transfer 208 , which is formed in the processing chamber 20 , is opened to load the substrate W to be processed which will mounted on the electrode part 501 . Thereafter, the gate valve 208 is closed and the processing space 402 is exhausted through the gas exhaust port 218 to be depressurized to be kept at a predetermined pressure. Subsequently, the valves 304 and 302 are opened, and Ar gas is supplied form the Ar gas supply source 305 into the processing space 402 while the flow rate thereof is controlled by the mass flow controller 303 . In the same manner, the valves 309 and 307 are opened, and H 2 gas is supplied form the H 2 gas supply source 310 into the processing space 402 while the flow rate thereof is controlled by the mass flow controller 308 . Thereafter, an RF power from the RF power supply 403 through the matching unit 405 , e.g., RF matching network, is supplied to the coil 404 to excite an inductively coupled plasma in the bell jar 401 . For example, in the manufacturing process of the semiconductor device, the plasma processing device 10 may be used in a processing for removing an impurity layer containing an oxide film formed on a metal film formed on the substrate to be processed, or an oxide film such as a native oxide film formed on a silicon. By removing such an impurity layer, adhesivity between a film to be formed thereafter and an underlayer may be improved, or sheet resistance of a film to be formed may be lowered. Specific conditions under which the impurity layer is removed are given as follows. For example, the pressure is in the range of 0.1˜13.3 Pa, and preferably, 0.1˜2.7 Pa. The temperature of the wafer is 100˜500° C. As for the flow rate of gas, that for Ar gas is 0.001˜0.03 L/mim; and that for H 2 gas is 0˜0.06 L/min, and preferably, 0˜0.03 L/min. The frequency of the RF power supply 403 is in the range of 450 kHz˜60 MHz, and preferably, 450 kHz˜13.56 MHz. The power of the bias RF power supply is within the range of 0˜500 W, and bias potential is in the range of −20˜−200 V. By performing the plasma processing for about 30 seconds under such conditions, e.g., a silicon oxide film (SiO 2 ) is removed by about 10 nm. Further, in case of removing a metal oxide film, e.g., Cu 2 O, specific conditions therefore are as follows. The pressure is within the range of 3.99×10 −2 ˜1.33×10 −1 Pa. The temperature of the wafer is in the range of 0˜200° C. As for the flow rate of gas, that for Ar gas is in the range of 0.001˜0.02 L/min, and preferably, 0.001˜0.03 L/min; and that for H 2 gas is in the range of 0˜0.03 L/min, and preferably, 0˜0.02 L/min. The frequency of the RF power supply 403 is in the range of 450 kHz˜60 MHz, and preferably, 45 kHz˜13.56 MHz. The power of the bias RF power supply is in the range of 50˜300 W, and the bias potential is in the range of −150˜−25 V. By performing the plasma processing for about 30 seconds under such conditions, e.g., a Cu 2 O film is removed by about 20˜60 nm. Still further, FIG. 9 shows the ranges of the frequencies of the plasma excitation RF and the bias RF and respective powers thereof, in the aforementioned process. Still further, in case of the bias RF, the range of the bias potential is also shown. The substrate supporting structure 50 is not limited to those shown in FIGS. 2˜6 , and it may be variously modified and changed. FIGS. 7A and 7B are partial cross sectional views of the substrate supporting structure in accordance with a modified example of the first embodiment. In a substrate supporting structure 62 shown in FIG. 7A , the dielectric layer 503 is formed only in a region that is not covered with the focus ring 510 on the top surface (to which the substrate W is contacted) of the electrode part 501 . As mentioned above, the part, in which the dielectric layer is formed, becomes simplified, so that the number of processings of, e.g., ceramic spraying, is reduced, and thus, lowering the production cost. Namely, the dielectric layer can be easily formed by such a method that ceramic powders are supplied into the plasma of an atmospheric pressure or vacuum to perform a plasma spraying coating on an object. Further, as described above, it is possible to variously change an area or a shape of the electrode part 501 to be coated with the dielectric layer, if necessary. In a substrate supporting structure 64 shown in FIG. 7B , a focus ring 510 A is thinner than the focus ring 510 of the substrate supporting structure 50 . The height of the top surface (to which plasma is exposed) of the focus ring 510 A coincides with that of the dielectric layer 503 . In this case, specifically, non-uniformity in the bias potential in the vicinity of edge of the substrate W is improved. As a result, an improvement in the uniformity in a sputter etching rate of in-surface of the substrate W can be realized. Further, a material of the focus ring may be changed to change permittivity thereof. In this case, since the bias potential in the vicinity of the wafer edge is changed, the in-surface uniformity in a sputter etching rate may be improved. FIG. 8 is a graph showing measurement results of the self-bias potential, in case where a high frequency power is applied to the mounting table. Herein, in the plasma processing device 10 having the substrate supporting structure 50 mounted thereon in accordance with the first embodiment, an RF power was applied to the substrate supporting structure 50 , and a self-bias voltage Vdc was measured at the substrate supporting table. Further, for comparison, the voltage Vdc for the conventional substrate supporting structure was measured. In the conventional substrate supporting structure, the RF transmission path was thin compared to the substrate supporting structure 50 , and a coaxial structure as described above was not formed. As for conditions of Vdc measurement, the flow rate of Ar gas was 2.9 sccm. The pressure in the processing chamber was 0.5 mTorr. The temperature of the mounting table was room temperature (about 20˜30° C.) in case of using the substrate supporting structure 50 ; and it was 200° C. in the conventional case. The plasma density was set at 2.5×10 10 atoms/cm 3 . For this, the RF power for plasma excitation was 1000 W in case of using the substrate supporting structure 50 ; and it was 800 W in the conventional case. As illustrated in FIG. 8 , Vdc of the substrate supporting structure 50 in accordance with the first embodiment was higher, compared to the conventional case. For example, if the RF power applied to the mounting table was 300 W, Vdc was 126 V in the conventional case, and 162 V in case of using the substrate supporting structure 50 , corresponding to a potential of about 1.3 times. The reason may be conjectured that, in the substrate supporting structure 50 in accordance with the first embodiment, the RF power is efficiently transferred by the coaxial structure using the transmission path 502 as a central conductor. Another reason may be considered that the introduction channel, the discharge channel, the DC wiring, the heat transfer gas path and the like are all disposed within the RF transmission path 502 , to thereby, lower impedance of the RF. That is, in the latter case, while the entire substrate supporting structure becomes small, the surface area of the transmission path 502 increases, and thus, lowering impedance of the RF. Second Embodiment In the aforementioned plasma processing device 10 , if the metal oxide formed on the surface of metal, e.g., copper, aluminum or the like, is etched, metal removed from the substrate W to be processed is scattered. Scattered metal is deposited onto the top surface of the insulating focus ring 510 around the substrate W to be processed, and thus, forming a metal film. If the metal film is grown, a discharge path may be formed between the substrate to be processed (semiconductor wafer) W and the conductive cover (pedestal conduction layer) 514 , which is grounded, through the metal film. In this case, since charged particles on the metal film flow on the cover 514 as a current, there may be incurred a loss of the RF power supplied to the electrode part 501 . For the same reason, the processing efficiency is lowered and the processing uniformity is deteriorated due to a decrease in the self-bias or abnormal discharge in the discharge path. Further, an electromagnetic configuration on the surface of the mounting table 51 may be seriously changed due to the formation of a metal film. In this case, the change due to the aging of the plasma state on the mounting table 51 may occur, and reproducibility of processing will be deteriorated. Further, if a conductive metal film is formed in the focus ring 510 , the situation becomes practically same as the case where a lower electrode has an area larger than the substrate W to be processed. In this case, the self-bias is lowered; the etching rate is lowered; and hence, the processing uniformity (inter-surface uniformity) between plural substrates to be processed is deteriorated. A second embodiment relates to a plasma processing device for resolving the aforementioned problems. Thus, a device in accordance with the second embodiment has an effective configuration for a case when processing a substrate having a conductive film. As for such a processing, there may be enumerated a processing for removing an oxide film formed on a surface of, e.g., Cu, Si, Ti, TiN, TiSi, W, Ta, TaN, WSi, poly-Si or the like. FIG. 10 is a configuration diagram showing a plasma processing device including a substrate supporting structure for semiconductor processing in accordance with the second embodiment of the present invention. As shown in FIG. 10 , a plasma processing device 70 has a cylindrical processing chamber 710 in which a mounting table 720 is disposed. The processing chamber 710 is connected to a gas supply unit 740 for supplying a processing gas thereinto. To a gas exhaust port 711 c formed in the center of bottom portion of the processing chamber 710 , there is airtightly connected a substantially cylindrical exhaust chamber 711 B, which is downwardly protruded. In the same manner as in the first embodiment, a support 730 for supporting the mounting table 720 is concentrically disposed in the exhaust chamber 711 B. An exhaust unit (not shown) having a vacuum pump and the like is coupled to a sidewall of the exhaust chamber 711 B through a gas exhaust line 716 . By the exhaust unit, an inside of the processing chamber 710 is exhausted, and at the same time, it is set to be kept at a predetermined vacuum pressure, e.g., in the range of 0.1 mTorr˜1.0 Torr. The processing chamber 710 is formed by combining a conductive cylindrical lower vessel 711 with an insulating cylindrical upper vessel or a bell jar 712 . The lower vessel 711 is made of a metal (conductor), e.g., aluminum, alloy thereof or the like. The bell jar 712 is made of an insulator, e.g., glass, ceramic (Al 2 O 3 , AlN) or the like. Around the bell jar 712 , an induction coil 713 is wound. The induction coil 713 is connected to an RF power supply 751 through a matching unit 752 . From the RF power supply 751 , an RF power of, e.g., 450 kHz is supplied to the coil 713 , so that an induced electromagnetic field is formed in the bell jar 712 . Further, the lower vessel 711 and the coil 713 are grounded. Between the lower vessel 711 and the bell jar 712 , a gas supply ring 714 is airtightly formed with a sealing material such as O-ring or the like. The gas supply ring 714 is connected to a gas source 741 (e.g., Ar gas) and a gas source 742 (e.g., H 2 gas) of the gas supply unit 740 , through valves and flow meters. The gas supply ring 714 has plural gas inlet openings disposed equi-spacedly around the processing chamber 710 . The gas inlet openings uniformly discharge a processing gas (plasma generation gas) supplied from the gas supply unit 740 towards the center of the bell jar 712 . At a sidewall of the lower vessel 711 , there is formed an opening 711 a , in which a gate valve 715 is disposed. While the gate valve 715 is opened, the substrate W to be processed can be loaded into the processing chamber 710 and unloaded therefrom. On a top portion of the bell jar 712 , an upper electrode 717 , which is grounded, is disposed to face in the direction toward the mounting table 720 . The upper electrode 717 is made of a conductive material such as aluminum, which is alumite processed. The upper electrode 717 serves as an electrode facing toward a lower electrode disposed on the mounting table 720 , and functions to prevent any failure of plasma ignition and to facilitate easy ignition. The upper electrode 717 fixes and assists the bell jar 712 through buffer members (plural pads, which are equi-spacedly disposed) 717 a made of, e.g. a resin and the like. An electrode part (lower electrode) 721 is disposed on the mounting table 720 . The lower electrode 721 is coupled to an RF power supply 753 through an RF transmission path 731 in the support 730 , a matching unit 754 and the like. From the RF power supply 753 , an RF power of, e.g., 13.56 MHz is supplied to the lower electrode 721 , and a bias potential is applied to the substrate W to be processed. Further, the lower electrode 721 and the transmission path 731 are molded as a unit in the same manner as in the first embodiment. In the lower electrode 721 , there is formed a heat exchange medium channel (temperature control space) 721 a as a flow path for flowing a heat exchange medium, e.g., an insulating cooling fluid, for adjusting the temperature of the mounting table 720 . Meanwhile, in the transmission path 731 of the support 730 , there are formed introduction channel 735 and discharge channel 736 for supplying the heat exchange medium in the temperature control space 721 a and discharging it therefrom. The introduction channel 735 and the discharge channel 736 are coupled to a circulation unit CU, e.g., a chiller or the like, which functions to control temperature. The heat exchange medium is circulated from the circulation unit CU to the temperature control space 721 a of the mounting table 720 through the introduction channel 735 and the discharge channel 736 , so that the temperature of the mounting table 720 is maintained at a predetermined temperature. For example, the substrate W to be processed is controlled to be kept at a predetermined temperature in the range of −20˜10° C. Instead of the temperature control space 721 a , any temperature control means may be provided in the mounting table 720 . For example, a resistance heater may be built in the mounting table 720 . The lower electrode 721 is covered with a dielectric layer (insulating layer) 722 such as alumina or the like, to be insulated from surroundings. The dielectric layer 722 forms a mounting surface of the mounting table 720 for mounting thereon the substrate W to be processed. An electrode 723 is inserted in the dielectric layer 722 of the mounting surface to form an electrostatic chuck therewith. The electrode 723 is connected to a DC power supply 755 disposed outside the processing chamber 720 through a wiring 737 , which extends through the transmission path 731 while being insulated. By applying a voltage to the electrode 723 , the substrate W to be processed is electrostatically adsorbed on the mounting table 720 . Side and bottom surfaces of the lower electrode 721 are covered with an insulating layer 725 made of an insulating material such as quartz and the like. A part of the lower and side surfaces of the insulating layer 725 is also covered with a cover 726 made of a conductive material such as Al and the like. The lower electrode 721 , the insulating layer 725 and the conductive cover 726 are coaxially configured. Meanwhile, the transmission path 731 of the support 730 is coated with an insulating layer 732 . The insulating layer 732 is also made of a conductive material such as Al and the like; electrically connected to the conductive cover 726 ; and coated with a cover 733 that is grounded. The transmission path 731 , the insulating layer 732 and the conductive cover 733 are coaxially configured. Namely, the substrate supporting structure in accordance with the second embodiment also is coaxially configured such that the mushroom shaped conductive cores 721 and 731 connected to the RF power supply for the bias 753 are covered with the insulating layers (dielectric layers) 725 and 732 , and also, covered with the conductive covers 726 and 733 that are grounded. Since the conductive covers 726 and 733 are grounded, charges flow to the ground even though an induced electromagnetic field is formed in the covers 726 and 733 . For the same reason, a plasma is not produced in an exhaust space below the mounting table 720 when the RF power is applied to the lower electrode 721 . By such a configuration, the loss of the RF power is reduced, and the bias can be applied efficiently and stably to the substrate to be processed. At an upper outer periphery of the mounting table 720 , there is disposed a conductive ring-shaped extension member 727 surrounding the substrate W to be processed. The extension member 727 has an exposed top surface in parallel with that of the substrate W to be processed (preferably, heights thereof are equal to each other) when the substrate W to be processed is mounted on the mounting table 720 . The extension member 727 is insulated from the electrode 721 by the dielectric layer 722 . Further, the extension member 727 is insulated from the conductive cover 726 by the insulating layer 725 or by having a sufficiently wide gap. In the second embodiment, the extension member 727 is insulated from all neighboring members, to which a potential is supplied. In other words, the extension member 727 is in a floating state where no potential is supplied. It is preferable that the conductive extension member 727 is configured to totally surround the periphery of the substrate W to be processed. The extension member 727 is formed of various conductive materials such as metal, e.g., titanium, aluminum, stainless steel or the like, or low resistance silicon. Preferably, the extension member 727 is formed of titanium or alloy thereof that hardly produces particles and the like due to the peeling of conductor. Alternatively, the surface of the extension member 727 may be coated with titanium or alloy thereof. Outside the processing chamber 720 , a driving source 761 formed of an electric motor, a fluid pressure cylinder and the like is disposed. The driving source 761 raises and lowers a plurality of lift pins 763 through a driving member 762 . By elevation of the lift pins 763 , the substrate W to be processed is elevated from the mounting surface of the mounting table 720 . By this, the lift pins 763 assists the substrate W to be transported to the mounting table 720 . FIG. 11 is a schematic configuration view showing a configuration of a main part of the plasma processing device shown in FIG. 10 . The plasma processing device 70 includes a conductive sealing box 719 coupled to the lower vessel 711 to cover the upper side thereof. The bell jar 712 and the induction coil 713 are accommodated in the sealing box 719 . The sealing box 719 is grounded, which functions to shut off any plasma emission (Ultra Violet or the like) or electromagnetic field. Further, the upper electrode 717 is supported by a member 718 in an upper part of the sealing box 719 . In the aforementioned plasma processing device 70 , a processing gas (e.g., gaseous mixture of Ar gas and H 2 gas) from the gas supply unit 740 is introduced into the processing chamber 710 through the gas supply ring 714 . At this time, the processing chamber 710 is exhausted through the exhaust chamber 711 B and the gas exhaust line 716 ; and it is set to be maintained at a predetermined pressure (vacuum), e.g., in the range of 0.1 mTorr˜1.0 Torr. In such a state, an RF power, e.g., in the range of 100˜1000 W, is applied to the induction coil 713 . By this, the processing gas turns into a plasma in the bell jar 712 , and a plasma region (P) is formed above the substrate W to be processed (see FIG. 10 ). If an RF power is supplied to the electrode 721 of the mounting table 720 , a self-bias voltage is generated. By such a self-bias voltage, ions in the plasma are accelerated to collide with the surface of the substrate W to be processed, and etching is carried out. In the plasma processing device 70 , a metal or an metal oxide on the surface of the substrate W to be processed, e.g., an oxide film on the surface of Cu, Si, Ti, TiN, TiSi, W, Ta, TaN, WSi, poly-Si or the like, is etched. In this case, as mentioned above, the metal is scattered from the substrate W to surroundings, so that a metal film may be formed in the surroundings. However, in the second embodiment, the aforementioned metal film is formed mainly on the exposed surface of the extension member 727 . FIG. 12 is a magnified partial cross sectional view showing that a metal film M is formed on the extension member 727 , in the plasma processing device shown in FIG. 10 . As illustrated in FIG. 12 , a gap 728 for sufficiently insulating the discharge path is formed between the extension member 727 and the conductive cover 726 . For the same reason, even though the metal film M is formed on the extension member 727 , an electromagnetic environment at the outer periphery of the mounting table 720 is hardly changed. Namely, even though the metal film M is formed on the extension member 727 , currents does not flow to the ground, and an electrode area is not changed. Moreover, there is no problem that the discharge path is formed at the outer periphery of the mounting table 720 , or abnormal discharge occurs. Further, since the conductive extension member 727 is sufficiently insulated from periphery members by the insulating layer 725 , there will be no current flow generated by the RF power supplied to the electrode 721 through the extension member 727 . Therefore, waste of processing power of the device resulting from a drift of the self-bias becomes reduced. Namely, in the second embodiment, the conductive extension member 727 is disposed from the beginning, expecting the formation of the metal film M, so that electromagnetic situation around the substrate W is hardly changed although the metal film M is formed. Accordingly, the uniformity (inter-surface uniformity) in a processing performed on plurality of substrates can be improved, since the plasma is uniformly produced on the substrate. One of the electromagnetic considerations is related with the insulation between the extension member 727 and the conductive cover 726 . If the upper portion of the cover 726 of the mounting table is close to the extension member 727 , a leakage in the power applied to the electrode 721 is increased and the processing cannot be performed efficiently and stably. In the configuration shown in FIG. 12 , a sufficiently long distance S through the gap 728 between the cover 726 and the extension member 727 is secured. Specifically, in the second embodiment, it can be configured that impedance Z 2 (a distance S between the extension member 727 and the cover 726 ) between the extension member 727 and the cover 726 is greater than impedance Z 1 (a thickness of the insulating layer 725 ) between the lower electrode 721 and the cover 726 . These impedance values are obtained by using as a reference frequency the RF applied to the lower electrode 721 . By such a configuration, it is possible to reduce (substantially suppress) the current due to the RF power applied to the electrode 721 that flows through the extension member 727 . In other words, an impedance change between the electrode 721 and the cover 726 due to the extension member 727 is hardly generated, and the discharge path is hardly formed. Further, as for a method for securing a sufficiently high insulation resistance (impedance) between the conductive cover 726 and the extension member 727 , an insulator (dielectric material) is disposed in the gap 728 such that it can be used to obtain a desired resistance by making a change in permittivity or shape thereof by design. For example, a dielectric material is disposed in the gap 728 indicated by the dotted line in FIG. 12 , so that substantial permittivity of the insulating material, disposed between the cover 726 and the extension member 727 , is changed. That is, impedance therebetween can be changed by disposing the insulator in the gap 728 , so that Z 2 may be designed to be greater than Z 1 . By doing this, the discharge path is not formed while the processing may be performed stably. Further, in the second embodiment, an exposed surface of the conductive extension member 727 is configured in parallel with the surface of the substrate W to be processed (preferably, heights thereof are equal to each other), so that the surface area of the electrode 721 of the mounting table 720 is substantially increased. Namely, same electromagnetic environment is provided in case where a surface area of the electrode 721 becomes π·(D 2 )2 due to the extension member 727 , compared to the case where the surface area of the electrode 721 is π·(D 1 )2. Herein, D 1 is a radius of the electrode 721 (a radius of simulated circle having the same area as an object); and D 2 is a radius corresponding to an outer peripheral shape of the extension member 727 . FIGS. 13A and 13B show simplified equivalent circuits of the mounting table 720 , for the cases when the electrode area of the mounting table 720 is assumed to be A 1 and A 2 and respective self-bias voltages are assumed to be V 1 and V 2 . Herein, the electrode areas A 1 and A 2 are π·(D 1 )2 and π·(D 2 )2, respectively, wherein A 1 <A 2 . In this case, following relationship is formed between the electrode area and the self-bias voltage. ( V 2/ V 1)=( A 1/ A 2) 4   (Relational equation 1) Namely, as described above, in case when A 1 <A 2 , and hence, V>V 2 , as the electrode area is increased, the self-bias voltage is rapidly decreased. Therefore, if the extension member 727 is not disposed, the processing will proceed and the metal film M will be deposited, so that an effective electrode area of the mounting table will get increased. Accordingly, the self-bias voltage is gradually decreased, and the processing state will be changed. Contrary to this, in the second embodiment, there exists the extension member 727 from the beginning of the substrate processing, as shown in FIG. 13B . Moreover, although the processing proceeds and the metal film M is adhered, the effective electrode area is hardly changed. Therefore, the self-bias voltage is hardly changed, and the processing can be performed stably. Further, the extension member 727 is configured to be attached to the mounting table 720 and detached therefrom freely, the extension member 727 can be readily replaced. In this case, maintenance of the device may be simply carried out. FIG. 14 is a magnified partial cross sectional view of the plasma processing device in accordance with the modified example of the second embodiment. This modified example has a configuration such that, compared to the configuration shown in FIG. 12 , the power leakage of the lower electrode 721 is reduced, and at the same time, it is unlikely to make the conductive cover 726 and the extension member 727 have a short circuit due to the metal film of by-product. Specifically, as illustrated in FIG. 14 , in the relationship between a thickness of the insulating layer 725 and a position of top end of the conductive cover 726 , it is configured to satisfy the relationship of L<T. Here, L means a level difference between the bottom portion of the insulating layer 725 in the side thereof and the top end of the cover 726 . Further, T means the thickness of the insulating layer 725 between the lower electrode 721 and the cover 726 . In other words, in the side of the insulating layer 725 , the top end of the conductive cover 726 is configured to be placed below the bottom portion of the lower electrode 721 . By this, it is possible to control impedances of Z 1 and Z 2 , thereby, improving uniformity of plasma. While the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. For example, in the first and second embodiments, the plasma etching device has been explained, but the present invention may be applicable to a plasma film forming device, a plasma ashing device or the like, in the same manner. The substrate to be processed is not limited to a semiconductor wafer, and a glass substrate, an LCD substrate or the like may be employed. In accordance with the present invention, it is possible to provide a substrate supporting structure and a plasma processing device for semiconductor processing capable of realizing a scaling-down to reduce the overall size and reducing cost. Further, in accordance with the present invention, it is possible to provide a plasma processing device capable of increasing at least inter-surface uniformity in a film formed on the substrate to be processed.

A substrate supportingstructure ( 50 ) for semiconductor processing, comprising a mounting table ( 51 ) for placing a processed substrate (W) disposed in a processing chamber ( 20 ), wherein temperature control spaces ( 507 ) for storing the fluid used as a heat exchange medium are formed in the mounting table ( 51 ), a conductive transmission path ( 502 ) is disposed to lead a high frequency power to the mounting table ( 51 ), and flow channels ( 505, 506 ) feeding or discharging the heat exchange medium fluid to or from the temperature control spaces ( 507 ) are formed in the transmission path ( 502 ).

FIELD OF THE INVENTION This invention relates to a method for generating molecular iodine, in situ, in the stomach of a preferably mammal for use as an effective therapeutic such as in the treatment of fibrocystic breast syndrome as well as other diseases that require either chronic or acute dosing of therapeutic iodine at a controlled ratio of molecular iodine to total iodine of above at least 0.65 and preferably between 0.80 and 1.0 and most preferably between 0.9 and 1.0. The present invention also relates to a non aqueous pharmaceutical composition which can be orally administered to a mammal to produce an effective iodine therapeutic that has a ratio of molecular iodine to total iodine of at least 0.65 upon contact with the gastric juices in the stomach of a mammal. The method and oral pharmaceutical compositions of the present invention generate molecular iodine internally only upon contact with the gastric juices in the stomach of a mammal and at a pharmaceutically acceptable dosage in a ratio of molecular iodine to total iodine above at least 0.65. BACKGROUND Iodine, including organically bound iodine, inorganic iodine and molecular iodine, i.e. I 2 , has been used to treat human diseases. Iodine-containing compounds have been employed extensively as expectorants. U.S. Pat. Nos. 4,187,294; 4,338,304 and 4,394,376 disclose compositions containing protein-bound iodine for the treatment of hypercholesteremia, diabetes and hyperlipemia. U.S. Pat. No. 4,259,322 discloses tuberculosis medication containing sodium iodide. Most recently, U.S. Pat. Nos. 4,816,255; 5,171,582; 5,250,304 and 5,389,385 disclose compositions of "elemental iodine" (I 2 ) in water for oral administration in humans to treat a variety of human diseases. U.S. Pat. No. 5,589,198 discloses the benefits of using elemental iodine or "iodine metal" with pharmaceutically acceptable carriers in the treatment of fibrocystic breast syndrome. Much of the prior art literature refers to "iodine" in an imprecise manner. The word iodine has been used in the literature to refer to several distinct chemical species that contain iodine atoms. Many different compounds with distinct and materially different properties contain iodine. For example, the literature on iodine disinfection clearly shows that the biocidal efficacy of diverse iodine species is profoundly different; molecular iodine (I 2 ) is an active biocide while iodide (I - ) has no biocidal activity. Traditional beliefs in the field of toxicology (R. C. Haynes Jr and F. Murad, "Thyroid and Antithyroid Drugs" in Goodman and Gilman's the Pharmacological Basis of Therapeutics, Eds. A. G. Gilman et al., 7 th ed., pp. 682-815, 1985, W. B. Saunders, Philadelphia) have held that molecular iodine and iodide have identical toxicity profiles; however, no direct experimental data was used to support this assumption. In fact, the toxicity and therapeutic efficacy of these different species of iodine could vary dramatically just as their biocidal activity does. Unfortunately, the pharmaceutical literature on iodine has not drawn distinctions between the properties of the many different chemical species that contain iodine atoms. The most serious concern for administration of an iodine pharmaceutical relates to the potential for toxic reactions. In this regard, it is believed that iodide is the form of iodine responsible for "iodide poisoning" or "iodism." There is no way of predicting which patient will react unfavorably to iodide, and an individual may vary in their sensitivity to iodide from time to time. A series of symptoms can result from iodism. Symptoms can include burning in the mouth and throat; soreness of the teeth and gum; increased salivation; coryza, irritation of the respiratory tract; cough; headache; enlarged glands; inflammation of the pharynx, larynx and tonsils; skin lesions; gastric irritation; diarrhea; fever; anorexia and depression; and severe and sometimes fatal eruptions (ioderma) may occur. In essence, human consumption of iodide at levels in excess of the range (0.150 to 1.0 mg/day) established by FDA researchers (J. A. Pennington, "A review of iodine toxicity reports", J. Am. Dietetic Assoc., Vol. 90, pp. 1571-1581) presents a health risk. The only scientific studies on the relative oral toxicity of molecular iodine and iodide was performed during the early 1990s (Karla Thrall, Ph.D. Thesis, "Formation of Organic By-Products Following Consumption of Iodine Disinfected Drinking Water", Summary and Conclusion Section, Oregon State University, Department of Chemistry, 1992). The weight of a mammals thyroid is one key diagnostic measure used to evaluate the toxicity of an iodine composition. Subchronic administration of iodide to male rats increased their thyroid weight at an iodide concentration of 10 mg/kg; molecular iodine did not effect thyroid weight even at concentrations of 100 mg/kg (Sherer et al., Journal of Toxicology and Environmental Health, Vol. 32, pp. 89-101, 1991). This study by Sherer did not measure an increase in the steady state levels of thyroid hormones until animals were exposed to repeated daily doses of molecular iodine at 10 mg per kilogram of body weight. It can be concluded from these studies that iodide can effect thyroid weight in mammals at concentrations that are 10 fold less than a comparable effect from molecular iodine. Another way to state this is that it required ten time more molecular iodine than iodide to effect animal thyroid function with an orally administered iodine composition. The human body contains approximately 18 to 20 mg of iodine. Iodine is an essential component of thyroxine and tri-iodothyronine. These hormones are essential for the maintenance of normal metabolic activity and they have an effect on almost every mammalian tissue. Excess iodine can lead to an imbalance in thyroid hormones. The reduced toxicity on the thyroid gland exhibited by molecular iodine as compared to iodide in the studies by Sherer et al. has important implications for design of an oral iodine pharmaceutical. These studies indicate that, all other factors being equal, molecular iodine is a preferred form of iodine for an oral drug. This would be especially true for disease states that require chronic administrations of said iodine pharmaceutical. An early observation of the association of thyroid/iodine with the human female breast was made in 1896, by Dr. Beatson, who treated metastatic breast cancer using desiccated thyroid in large doses. Desiccated thyroid contains an abundance of protein-bound iodine. An early association of an iodine deficiency state and benign breast dysplasia was reported in 1966 by a clinician who reported a 71% improvement rate in women with dysplastic mastodynia treated with iodine (Vishnyakova V. V. et al., "On the Treatment of Dyshormonal Hyperplasia of Mammary Glands", Vestin. Sakad. Med. Mauk. S.S.S.R., Vol. 21:p. 19, 1966). Treatment of mammary dysplasia using traditional Chinese medicines like Sargassum, which contains a high iodide concentration, has provided cure rates of 65.4 percent. Ghent (U.S. Pat. Nos. 5,389,385 and 5,589,198) explored the use of elemental iodine treat a variety of human diseases. The scientific literature provides clear evidence that iodine in several different forms is an effective therapeutic against many different mammalian diseases. Animal models of fibrocystic breast syndrome have been studies for over 40 years. Several studies provide evidence that indicates iodine can reverse this condition. Studies in humans have shown improvement or complete elimination of fibrocystic breast syndrome after several months of iodine therapy. Other mammalian disease states that have been treated with iodine include ovarian cysts, premenstrual syndrome, breast cancer and endometriosis. For convenience, certain terms employed in the specification, examples, and appended claims are defined below. The term "molecular iodine" as used herein, refers to diatomic iodine, which is represented by the chemical symbol I 2 , which exists in a liquid. The term "elemental iodine" as used herein, refers to solid diatomic iodine, which is represented by the chemical symbol I 2 . The term "iodide" or "iodide anion" refers to the species which is represented by the chemical symbol I 31 . Suitable counter-ions for the iodide anion include sodium, potassium, calcium, and the like. The term "triiodide" refers to the species which is represented by the chemical symbol I 3 - . It is recognized by one skilled in the art that triiodide is formed from the interaction of one iodide anion and one molecule of molecular iodine under the laws of mass action and that triiodide rapidly dissociates into one iodide anion and one molecule of molecular iodine. The term "total iodine" as used herein, refers to the following iodine species: molecular iodine, iodide, organically complexed forms of iodine, covalently bound forms of iodine, iodite, triiodide, polyiodides containing more than 5 atoms of iodine and elemental iodine. The term "rate of iodine generation" as used herein, refers to the rate at which molecular iodine is formed in a liquid environment. The term "ratio of molecular iodine" as used herein, refers to the ratio of molecular iodine (I 2 ) to all other iodine species such as iodide, triiodide and polyiodides containing more than 5 atoms of iodine or total iodine. Elemental iodine is sold commercially as blue-black crystals with a high metallic luster. The major difficulty with the preparation of a suitable oral composition of molecular iodine is related to the basic physical chemistry of this element. All solid forms of elemental iodine sublime readily to generate a violet-colored vapor. In fact, atmospheric iodine is a major component of global iodine cycling. Unfortunately, the facile sublimation of elemental iodine introduces an inherent instability which precludes its use, per se, as the active ingredients in a pharmaceutical preparation. Other chemicals are combined in some form with elemental iodine in order to provide stable preparations that contain molecular iodine. There are three different types or categories of oral iodine compositions that have been used to treat disease states in mammals: (1) organically bound iodine including both covalent binding and hydrophobic/ionic complexes, (2) inorganic iodine and (3) aqueous molecular iodine. Organic iodine compounds, which have been used "off-label" as nutritional iodine supplements, are designed for use in the area of radiographic contrast mediums (radiopaque compounds). For instance, lymphography is used to detect and evaluate abnormalities of the lymphatic system and as a guide to surgical dissection of lymph nodes. Iodine-based radiopaque compounds are likewise employed in several different diagnostic procedures, i.e. cholecystography, myelography, urography, angiographycholangiography. A number of different organic iodine compounds have been used for this purpose including β-(4-hydroxy-3,5-diiodophenyl)-α-phenylpropionic acid, β-(3-amino-2,4,6-triiodophenyl)-α-ethylpropionic acid, iodophenylundecylate, 3,5-diacetamido-2,4,6-triiodo-benzoate, 3,5-diacetamido-2,4,6-triiodo-benzoic acid, and ethiodized oil. The iodine atoms in these compounds are covalently bound to organic molecules. Other forms of organic iodine have been used as therapeutics including protein-bound iodine, desiccated thyroid and iodine metabolically incorporated into chicken eggs. Inorganic iodine compositions that have been used as oral therapeutics include sodium or potassium iodide; tincture of iodine or Lugol's solution; and organic iodides that yield iodide. Aqueous compositions of these species inherently contain a very low and/or unpredictable ratio of molecular iodine to total iodine. In fact, these compositions usually contain less molecular iodine on a molar basis than other forms of iodine. For instance, Lugol's solution contains approximately 129,000 ppm of total iodine but only 170 ppm of molecular iodine or a ratio of 0.0013. Pure aqueous solutions of molecular iodine do not exist in commerce. Molecular iodine is known to be unstable in water and this instability is a function of pH. Molecular iodine is hydrated by water and, in an aqueous system, undergoes the series of reactions shown below in equations 1 to 3. I.sub.2 +H.sub.2 O=HOI+I.sup.- +H.sup.+ ( 1) 3HOI=IO.sub.3.sup.- +2I.sup.- +3H.sup.+ ( 2) I.sub.2 +I.sup.- =I.sub.3.sup.- ( 3) It is not possible to make and bottle a stable aqueous solution that contains at least a molecular iodine ratio of 0.65. For clinical applications, this limitation has previously been addressed by preparing aqueous solutions of iodine immediately prior to use and then consuming them. Elemental iodine dissolves very slowly in water. The long time necessary to dissolve elemental iodine causes the loss of some nascently formed molecular iodine due to its reaction with water as shown in equation 1 above. As a result, there are problems of consistency and ease of use with this method. Compositions that contain several different pharmacologically active agents with diverse toxicity profiles are not preferred as pharmaceutical agents. An ideal drug produces its desired effect in all patients without causing toxic effects. The relationship between the desired and undesired effects of a drug is termed its therapeutic index or selectivity. The therapeutic index for a drug is frequently represented as the ratio of the median toxic dose to the median effective dose. In clinical studies, drug selectivity is often expressed indirectly by summarizing the pattern and nature of adverse effects produced by therapeutic doses of the drug and by indicating the proportion of patients with adverse side effects. Each separate iodine species should be considered to be a unique drug entity since they have been shown to have different oral toxicity and therapeutic index profiles. Therefore, a preferred "iodine" therapeutic is a composition wherein the all or an overwhelming majority of the total iodine atoms present are in the desired form. The prior art demonstrates that molecular iodine is an effective therapeutic agent in a number of disease states. For instance, Eskin et al. (Biological Trace Element Research, Vol. 49, pp. 9-18, 1995) demonstrated that molecular iodine is "distinctly more effective in diminishing ductal hyperplasia and perilobular fibrosis in the mammary glands than iodide". The scientific literature also indicates that the oral toxicity of iodide is greater than that for molecular iodine. Another way to state this is to say that the prior art in animals and humans demonstrates that the most therapeutic form of iodine, when administered orally, is molecular iodine; also, the least toxic form of iodine when administered orally is molecular iodine. Therefore, the prior art indicates that all of the iodine in a preferred oral iodine pharmaceutical should be molecular iodine. This distinction in toxicity is especially important for a treatment regime that requires chronic dosing. As a practical matter it is acceptable to limit the potential for toxicity due to iodide to a safe range. In order to accomplish this latter objective it is necessary to limit the concentration of iodide by weight to no more than 1,000 ug/day of iodide when administered chronically and preferably it should provide no more than 150 ug/day and most preferably it should provide no more than 50 ug/day. Since the toxicity of an oral pharmaceutical iodine drug is directly related to the ratio and concentration of the different iodine species present; the known instability of the I 2 species presents a challenge to the development of an oral iodine pharmaceutical composition with a preferred therapeutic index. This application describes methods to overcome the problems that exist with the prior art in the delivery of molecular iodine in an acceptable stable oral pharmaceutical. SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows the relationship between Molecular Iodine, Iodate and Iodine. This application teaches a novel pharmaceutical composition for oral administration to a mammal which will convert into an effective iodine therapeutic upon contact with the stomach juices of the mammal and at a ratio of molecular iodine to total iodine of 0.65 to 1.0. This application also teaches a method for generating an effective iodine therapeutic, in situ, in the stomach of a mammal for the treatment of fibrocystic breast syndrome and other diseases that require chronic or acute dosing of therapeutic iodine. The oral pharmaceutical compositions of the present invention generate molecular iodine only upon contact with the gastric juices in the stomach of a mammal and at a pharmaceutically acceptable dosage in a ratio of molecular iodine to total iodine above at least 0.65. It should be understood that it is not presently possible to make and/or bottle a stable aqueous solution containing molecular iodine at a molecular iodine ratio relative to total iodine at or above 0.65. Iodine sublimes at room temperature and reacts with water as previously described. These two properties make it very difficult to formulate molecular iodine; it is especially difficult to prepare compositions wherein most of the iodine exists as molecular iodine. The pharmaceutical composition of the present invention does not incorporate elemental iodine or molecular iodine in situ. The present invention provides for dramatically improved stability relative to composition that incorporate molecular iodine. Control of molecular iodine is provided by the present invention which results in generating molecular iodine at ratios of molecular iodine to total iodine between 0.65 and 1.0 and more preferably between 0.80 and 1.0 and most preferably between 0.9 and 1.0 upon contact with the gastric juices. In accordance with the method of the present invention therapeutic iodine is administered to a mammal by feeding the mammal an effective amount of an oxidant and reductant for an iodine species which will cause oxidation-reduction reactions upon contact with the gastric juices present in the stomach of the mammal such that molecular iodine is generated, in situ, at a ratio of molecular iodine to total iodine above at least about 0.65. The pharmaceutical composition of the present invention does not incorporate any elemental iodine or aqueous molecular iodine; the compositions described herein rely upon the environment provided by gastric fluid to initiate the formation of molecular iodine. The composition of the present invention may be provided in the form of a kit of unreacted components that react with stomach fluids to generate molecular iodine in situ. The pharmaceutical composition of the present invention can be incorporated into a single powder, capsule, tablet, caplet or liquid; in addition, combinations of these physical formats can be utilized. Oxidation and reduction reactions of different iodine species can be used to achieve this end. The principal oxidation states of iodine are -1, +1, +3, +5 and +7. Stable species in one of these oxidation states can be admixed in stomach fluids in either an oxidative or reductive environment to yield the desired iodine species which is molecular iodine. The advantages of generating molecular iodine in situ within the stomach upon contact with the stomach fluids are: (1) production of stable, pharmaceutically acceptable composition; (2) production of a controlled dosage of molecular iodine in situ; and (3) the ratio of molecular iodine is controllable at levels above 0.65. The methods described above allow an accurate dosage regime to be achieved and the reduction of unwanted toxic side-effects associated with iodide, triiodide and polyiodides. In addition, the therapeutic efficacy for certain disease states like fibrocystic breast syndrome is increased. DETAILED DESCRIPTION OF THE INVENTION The method described in this application describes a system for the in situ generation of molecular iodine in the stomach. It is necessary to account for the composition of gastric fluid when designing such a composition. The low pH of gastric fluids influences this type of chemistry. The principal oxidation states of iodine are -1, +1, +3, +5, and +7. Compounds that are representative of these states include KI, ICl, ICl 3 , IF 5 , and Na 5 IO 6 , respectively. The oxide IO 2 is known and appears to be the sole representative of +4 oxidation state. Molecular iodine (I 2 ) can be formed by either reducing an iodine species with a positive oxidation state or oxidizing the iodide anion (I - ). Alternatively, it is possible to use an oxidant and reducing agent which both contain iodine. The oxidation potentials for the different oxidation states of iodine in an acidic solution are represented below: ##STR1## There exists a variety of iodine species in different oxidation states. The positive oxidative states are usually found in inorganic species such as acids, salts, oxides, or halides. The negative oxidative states appear in iodine species that are in the form of iodide salts or organic iodo-compounds. The oxidation states of iodine and some iodine species that are representative of those states are shown below: +7: periodic acid (H 5 IO 6 ), potassium periodate (KIO 4 ), sodium periodate (NaIO 4 ). +5: iodic acid (HIO 3 ), potassium iodate (KIO 3 ), potassium hydrogen iodate (KHI 2 O 6 ), sodium iodate (NaIO 3 ), iodine oxide (I 2 O 5 ). +3: iodine trichloride (ICl 3 ), +1: iodine monobromide (IBr), iodine monochloride (ICl). -1: hydriodic acid (HI), sodium iodide, potassium iodide, ammonium iodide, aluminum iodide (AlI 3 ), boron triiodide (BI 3 ), calcium iodide (CaI 2 ), magnesium iodide (MgI 2 ), iodoform (CHI 3 ), tetaiodoethylene (C 2 I 4 ), iodoacetic acid, iodoethanol, iodoacetic anhydride. Molecular iodine can be formed from oxidation-reduction reactions according to the above indicated oxidation-reduction potentials of the half-reaction for an iodine species. Another way of stating this is as follows: substances with lower oxidation potentials can reduce an iodine species to molecular iodine and substances with a higher oxidation potential than iodide can oxidize iodide into molecular iodine. There are many chemicals known to one skilled in the art that will function in this fashion. One desired feature of the in situ generation method is to provide a composition that is non-toxic once it has contacted gastric fluids contained in the stomach. Another parameter of this method is the speed at which molecular iodine is generated once the composition contacts gastric fluids. Another important feature of this method is to provide a reproducible quantity of molecular iodine. Suitable oxidants for the in situ generation method include hydrogen peroxide, iodate, monopersulfate, other alkalai salts of peroxide like calcium hydroxide, peroxidases that are capable of oxidizing iodide, ascorbic acid and/or other organic acids that are generally regarded as safe. A preferred oxidant for this invention is hydrogen peroxide. Any material that acts as a source of an oxidizing peroxy functionality when ingested is suitable for the present invention. The term "source of hydrogen peroxide" for purposes of the present invention and as used herein shall mean any material alone or in combination which is pharmaceutically acceptable to serve as a precursor for an oxidizing peroxy functionality including percarbonates, perphosphates, urea peroxide, peroxy acids, alkylperoxides, peroxyacids and perborates. Mixtures of two or more of these substances can be used. The preferred oxidant for this invention for use in combination with the iodide anion is iodate. The iodate anion consists of one atom of iodine and three atoms of oxygen and has a negative charge associated with it at a pH of 7.0. Preferred sources of iodate include sodium iodate and potassium iodate. The term "source of iodate" for purposes of the present invention and as used herein shall mean any material alone or in combination which is pharmaceutically acceptable to serve as a precursor for the liberation or delivery of iodate upon contact with stomach fluids. Suitable reductants for the in situ generation method include iodide, sodium thiosulfate, ascorbate, simple reducing sugars such as lactose, imidazole and other reductants well known to one skilled in the art. The oxidant and reductant used to generate molecular iodine can be combined in a dry state with other well known pharmaceutical excipients to facilitate the manufacture of capsules, tablets and pills. Examples of such well known non-toxic excipients include: various phosphates, sucrose, lactose, maltodextrins, mannitol dextrates, dextrose, glucose, citric acid, sorbitol microcrystalline cellulose, starches, calcium carbonate, carboxymethylcellulose, polyethylene glycol boric acid, leucine, sodium chloride, benzoate, acetate, oleate, magnesium stearate, stearic acid, talc and hydrogenated vegetable oils. Other excipients will occur to one skilled in the art and are incorporated for the purposes of this application. Preferred excipients should have the following characteristics: (1) not effect the stability of the oxidant and reductant; (2) not interfere with the interaction between the oxidant and reductant; (3) not effect the yield of molecular iodine; (4) not materially react with molecular iodine in a fashion that effects the absolute concentration of molecular iodine, and (5) not effect the ratio of molecular iodine to total iodine after it is formed in the stomach and during the time which molecular iodine is processed by the mammal in the stomach or intestines. Alternatively, it is possible to incorporate the components of the in situ generation method into a liquid that is swallowed prior to, after or contemporaneous with a powder, capsule or tablet. A variety of liquid compositions familiar to one skilled in the art are acceptable provided that the stability of the reactants to yield iodine is maintained. An example of one such liquid composition would be a suspension of powders in a viscous hydrophobic liquid such as mineral oil. Two dosage ranges for molecular iodine are contemplated in this application; a range for chronic dosing and a range for acute dosing. Treatment of stomach ulcers which are caused by the presence of Helicobacter pylori in the stomach lining would be an example of a disease state that requires acute dosing. Treatment of breast displasia is an example of a disease that requires chronic dosing. The amount of molecular iodine to be provided per day for treatment of breast displasia is between 0.5 and 7.5 mg per day for a 100 pound female mammal with a preferred range of iodine for consumption between 1.0 and 5.0 mg per day. The amount of molecular iodine to be provided per day for prevention of breast displasia is between 125 ug and 0.5 mg per day for a 100 pound female mammal with a preferred range of iodine for consumption between 125 ug and 250 ug per day. The amount of molecular iodine delivered per day for acute dosing can be between 5 and 35 mg with a preferred range of iodine for consumption between 7.5 and 15 mg per day. An important parameter of any iodine pharmaceutical is its therapeutic index. The therapeutic index for an iodine pharmaceutical is proportional to the ratio of molecular iodine to total iodine provided by said pharmaceutical. The higher the ratio of molecular iodine to total iodine, the higher the therapeutic index for the iodine composition. The ratio of molecular iodine to total iodine that is generated by iodine pharmaceuticals described in this application is between 0.65 and 1.0 with a preferred ratio of between 0.80 and 1.0 and a most preferred ratio of 0.95 and 1.0. For treatment of disease states that require chronic administration of iodine, such as fibrocystic breast syndrome, it is especially preferred to provide a composition that provides a ratio of 0.95 to 1.0. Since molecular iodine is the least toxic form of iodine, chronic administration of an oral iodine therapeutic should be based upon molecular iodine. In order to limit toxicity from unwanted iodide it is necessary to limit the concentration of iodide (that remains after in situ generation of molecular iodine). In no event should the amount of iodide in such a composition provide more than 1,000 ug/day of iodide when administered acutely and preferably it should provide no more than 150 ug/day when administered chronically and most preferably is should provide no more than 50 ug/day. Therefore, as described in this application, the concentration of iodide in an iodine pharmaceutical for acute dosing that contains 20 mg of total iodine, should be less than 1 mg or 5% and preferably the iodide concentration should be 150 ug (or 0.75%) or less of the total weight of iodine present. The ratio of molecular iodine to total iodine can be between 0.65 and 1.0 with a preferred ratio of between 0.80 and 1.0 and a most preferred ratio between 0.95 and 1.0. The higher the ratio of molecular iodine to total iodine, the higher the therapeutic index for the iodine composition. The rate of iodine generation should be rapid with at least 75% of the equilibrium concentration of molecular iodine being generated within the first 10 minutes of contact between the specific iodine generating chemical agents and the stomach fluids. The stability of the composition should be such that at least 90% of the molecular iodine generating capability remains after storage in appropriate packaging at 25° C. in relative humidity of 75% for at least 3 months and preferably 6 months. It is very important that the ratio of molecular iodine generated to total iodine does not materially change during storage. The variability of the ratio of molecular iodine to total iodine is one of the problems with some of the compositions described in the prior art. EXAMPLES Example 1 Total iodine was measured by thiosulfate titration as described in the United States Pharmacopeia (USP). Molecular iodine was measured by the method of Gottardi (Gottardi, W., Fresenius Z. Anal. Chem. Vol. 314, pp. 582-585, 1983) which relies upon measurement of the redox potential, iodide concentration and pH. Two Corning Model 345 pH meters were used in combination with a platinum reference electrode (Fisher Cat. No. 13-620-115), a Calomel electrode (Fisher Cat. No. 13-620-51) and iodide ion selective electrode (Corning Model 476127); a saturated solution of elemental iodine at 25° C. was used to calibrate the system. Horseradish peroxidase is known to catalyze the formation of iodine in the presence of hydrogen peroxide via the oxidation of iodide. Simulated gastric fluid (SGF), as described in the USP, was prepared as follows: 2.0 grams of sodium chloride was dissolved in 750 mL of distilled water and then 7.0 mL of hydrochloric acid containing 3.2 grams of pepsin was added along with enough distilled water to bring the total volume to 1000 mL. Horseradish peroxidase (HRP) was dissolved in SGF at a concentration of 1.0 mg/mL. The activity of the horseradish peroxidase and its absorbance at 406 nm was monitored over the course of an hour. There was only a 20% decrease in the absorbance at 406 nm indicating that the tertiary structure of HRP is relatively stable in the presence of SGF. The rate at which horseradish peroxidase catalyzed the formation of iodine was correspondingly reduced at the end of the hour by approximately 33%. Five grams of citric acid and 1 gram of sodium citrate were combined in one liter of water to yield a buffer with a pH of 3.0. A second identical buffer was prepared that contained 10% pig mucin. A mixture of two powders, sodium iodide (1 gram) and HRP (5 mg) was made, and used subsequently as a single reagent. The following reaction was initiated. Five hundred mL of buffer or five hundred mL of 10% mucin was mixed with 1.0 grams of the iodide/HRP mixture and 1.0 mL of 30% hydrogen peroxide. The concentration of molecular iodine was monitored as a function of time by the method of Gottardi. At eight minutes the buffer control had a molecular iodine concentration of 30.1 ppm; the same reaction in 10% pig mucin had a concentration of molecular iodine of 38.1 ppm. This experiment demonstrates that a HRP can be used to catalyze the oxidation of iodide by hydrogen peroxide in the stomach and can generate molecular iodine in gastric fluid and in the presence of mucin. Additional experiments using Lugol's solution diluted in simulated gastric fluid at various ratios in the presence of 10% mucin did not yield any measurable molecular iodine. This experiments suggests that it may be advantageous to generate molecular iodine in situ in the stomach as opposed to delivering molecular iodine to the stomach. Example 2 The effect of SGF with 10% pig mucin on three different types of iodine compositions was determined. The three different types of iodine solutions were (1) Lugol's solution diluted to deliver approximately 150 ppm of titratable iodine; (2) 10% polyvinylpyrrolidone iodine diluted to deliver approximately 150 ppm of titratable iodine; and (3) a mixture of HRP (1.5 mg/liter), sodium iodide (2 grams/liter) and hydrogen peroxide (0.08% w/v) that generates approximately 150 ppm of titratable iodine. The concentration of molecular iodine was determined potentiometrically for these three different iodine compositions in the absence and presence of 10% pig mucin and the results are shown below. ______________________________________Iodine Compositions in Simulated Gastric Fluid Molecular IodineIodine Composition SGF SGF + 10% mucin______________________________________10% polyvinylpyrrolidone 9 0Lugol's solution 59 0HRP/iodide/peroxide mixture 15 40______________________________________ This experiment demonstrates that it is possible to generate significant concentrations of molecular iodine in the environment found in the stomach and that it may be preferable to generate said iodine in situ as compared to delivering iodine to the stomach in an aqueous composition. Example 3 SGF was prepared as described in the USP and sodium iodate was dissolved in the SGF to a final concentration of 0.375 millimolar. A sequential addition of sodium iodide was made to the iodate solution. Sodium iodide was added to the iodate solution in different aliquots such that the concentration of added iodide ranged between 0.25 and 3.0 millimolar. After each addition of iodide the analytical chemistry of the resulting composition was determined. The concentration of molecular iodine increased in a nearly linear fashion between an iodide concentration of 0.0 and 1.75 mM and then flattened out. The most obvious explanation for this observation is that once the majority of iodate had been reduced, further addition of iodide did not produce any material formation of molecular iodine. Instead of an increase in molecular iodine, the concentration of iodide increased. The concentration of sodium iodide increased in a nearly linear fashion between a sodium iodide concentration of 1.75 and 3.0 mM, while, under the identical conditions, the concentration of molecular iodine increased by less than 5%. FIG. 1 shows the results of these test. At an iodide input of 1.75 mM the concentration of molecular iodine was 1.01 mM; this is equal to about 96% of theoretical maximum yield of molecular iodine. This experiment was repeated using 2.5 mM sodium iodate and a concentration of sodium iodide that ranged between 0 and 25 mM. The results were qualitatively identical. As iodide was added the concentration of molecular iodine increased in a linear fashion between an iodide concentration of 0 and 12.5 mM. Once the majority of iodate had been reduced, further addition of iodide did not produce any material increase in the concentration of molecular iodine. The concentration of sodium iodide increased in a nearly linear fashion between a sodium iodide concentration of 12.5 and 25.0 mM without a corresponding increase in molecular iodine. At an iodide input of 12.5 mM the concentration of molecular iodine was 7.17 mM; this is equal to 95% of theoretical maximum yield of molecular iodine. These results indicate that it is possible to generate molecular iodine in the environment found in a human stomach in a fashion such that a material concentration of iodide does not result from the supplied chemicals. For example, when using 0.375 mM iodate and 1.75 mM sodium iodide, there was no detectable concentration of iodide while the concentration of molecular iodine was about 1.1 mM. Correspondingly, with 2.5 mM iodate and 12.5 mM iodide there was no detectable concentration of iodide while the concentration of molecular iodine was about 7.3 mM. This experiment identifies the preferred molar ratio of iodide to iodate in order to provide a composition that provides principally molecular iodine and which thereby limits the concentration of iodide. Limiting the concentration of iodide is important for disease states that require chronic dosing. Example 4 A powder blend containing magnesium stearate, sorbitol, sodium iodide and sodium iodate was prepared. The following amounts of each material was weighed on an analytical scale (AND Company Ltd.; Model FX-3000); 25 grams of magnesium stearate; 1,000 grams of sorbitol; 55 grams of sodium iodide; and 15.75 grams of sodium iodate. Standard gelatin capsules were filled with 1 grams of the blended material and placed in screw-top wide-mouthed polyethylene bottles containing a single disposable desiccant cartridge (Fisher Cat. No. 08-594-14A). The polyethylene bottles were placed in a constant temperature environmental chamber at 40° C. in 75% relative humidity. Once a week for a three month time period, three capsules were removed, allowed to come to room temperature, and dissolved in simulated gastric fluid. The concentration of molecular iodine was determined immediately after dissolution by a potentiometric measurement. The concentration of molecular iodine did not change over a three month time period. The percentage of the concentration measured on day 1 was plotted versus time. No trend could be detected in a graph of the concentration of molecular iodine versus time. Example 5 Soybean peroxidase (E.C. 1.11.1.7) was used in conjunction with hydrogen peroxide and iodide to generate molecular iodine in situ. The ratio of molecular iodine to total iodine was calculated. Several different reaction conditions in a citrate/carbonate buffer were established at pH values of 1.7, 4.5 and 5.0. The concentrations of the different reactants at a pH of 5.0 are shown below in tabular form. ______________________________________Reaction Conditions for Soybean peroxidase at pH 5.0 Volume Used (ml) Reaction 1 Reaction 2 Reaction 3______________________________________0.05 molar citric acid 16 16 160.1 gram/ml sodium carbonate 8.22 8.2 8.1230 mg/ml sodium percarbonate 0.41 0.50 1.5630 mg/ml sodium iodide 0.33 0.40 1.33water QS to 200 ml______________________________________ The reactions at pH 5.0 were initiated adding 0.2 ml of soybean peroxidase (5 mg/ml) and gently mixing. The concentration of molecular iodine was measured at 20 minutes by the potentiometric method of Gottardi. The concentration of molecular iodine for the three conditions at pH 5.0 was as follows: reaction 1 was 43 ppm; reaction 2 was 51 ppm and reaction 3 was 159 ppm. The ratio of molecular iodine to total iodine for the three reactions was 1.02, 1.0 and 0.94 respectively. Another reaction was initiated at pH 4.5 using the following experimental conditions. The following chemicals were added to 1200 ml of water: 4.65 grams of citric acid, 2.0 grams of sodium carbonate, 0.252 grams of sodium iodide, 6 milligrams of lactoperoxidase (E.C. 1.11.1.7) and 80 mg of urea hydrogen peroxide. After 20 minutes the concentration of molecular iodine was determined to be 172 ppm by the potentiometric method of Gottardi. The ratio of molecular iodine to total iodine was 0.97. Example 6 An iodine pharmaceutical must be absorbed to provide a therapeutic benefit. Ghent (U.S. Pat. Nos. 4,816,255; 5,171,582) has shown that Lugol's solution is an effective therapeutic for the treatment of fibrocystic breast syndrome. This experiment was designed to demonstrate that the bioavailability of molecular iodine generated in situ is at least equal to that of Lugol's solution. Female Sprague-Dawley rats weighing 150-250 grams that were 6-7 weeks old were purchased from Charles River Canada, Inc. (Quebec, Canada). Rats were housed individually in stainless steel wire mesh-bottomed rodent cages equipped with an automatic watering system. Following randomization, all cages will be clearly labeled with a color-coded cage card indicating study number, group, animal number, sex and treatment. Each animal was uniquely identified by an individual ear tag following arrival. The environment was controlled at 21°±3° C., 50±20% relative humidity, 12 hours light, 12 hours dark and 10-15 air changes were made per hour. Animals were provided with Teklad (Madison, Wis.) Certified Rodent Diet (W) #8728 ad libitum. Municipal tap water that was purified by reverse osmosis and treated by ultraviolet light was provided ad libitum. The animals were allowed to acclimate to their environment for at least two weeks prior to the start of the experiment. Rats were dosed with 1.0 ml per 250 grams for each treatment group. The concentration of iodine-based drug was either 0.1 mg/kg (the low dose "L") or 1.0 mg/kg (the high dose "H"). Different types of iodine-based drugs were dosed. Lugol's is known to be an effective treatment against fibrocystic breast syndrome and it was used as the positive control. Compositions that contained sodium iodide and sodium iodate alone, or in combination with other agents, were used as the experimental treatments. The ratio of iodide to iodate was controlled so that essentially all of the iodide was converted into molecular iodine. The experimental treatments included (1) NaI/NaIO 3 - mixed prior to gavage; (2) NaI/NaIO 3 - in 0.7% HCl gavaged separately; (3) NaI/NaIO 3 - in 1% starch; and (4) NaI/NaIO 3 - in 1% sorbitol. Blood was drawn from animals prior to treatment. Animals were gavaged and blood was taken 2 hours later when the animals were sacrificed. The blood was processed to yield serum samples and these samples were frozen. The frozen samples were analyzed by utilizing the reduction-oxidation reaction between ceric and arsenite catalyzed by iodide. This method provides a measure of the total iodine that is absorbed in serum. The results of the these measurements are shown below in tabular form. ______________________________________Bioavailability of Iodine (ug I.sup.- /dl) in Serum Conc. 2 hr.Treatment Group (mg/kg) pre-dosing post-dosing______________________________________Lugol's H 9.79 130.6 L 9.50 20.9NaI/NaIO.sub.3 .sup.- mixed prior to gavage H 9.08 148.5 L 12.11 24.1NaI/NaIO.sub.3 .sup.- in 0.7% HCl separately H 9.60 167.3gavaged L 10.8 30.7NaI/NaIO.sub.3 .sup.- in 1% starch H 9.42 169.8NaI/NaIO.sub.3 .sup.- in 1% sorbitol H 9.60 165.0______________________________________ The NaI/NaIO 3 - compositions were absorbed by the rats to a degree that was equivalent with or greater than Lugol's solution. This indicates that the iodine in these treatments is available to mammalian tissue. Example 7 A seven day dosing study was conducted at different concentrations of iodine to determine the acute oral toxicity of a NaI/NaIO 3 - composition. Twenty Sprague-Dawley female rats were divided into 4 groups with five animals in each group. Animals were selected and treated as described above in Example 6. Rats were dosed once each day with a NaI/NaIO 3 - composition or water (control groups). The NaI/NaIO 3 - composition was formulated so that essentially all of the iodine atoms were converted into molecular iodine upon use. The dose level used in the three treatment groups was (1) 0.1 mg/kg; (2) 1.0 mg/kg and (3)10 mg/kg. Each animal was dosed with approximately 2 ml per 250 grams. During the treatment period, clinical signs (ill health, behavioral changes etc.) were evaluated at cage-side twice a day. Funduscopic and biomicroscopic examinations were performed for all animals during the pretreatment period and at the end of the treatment period. Animals were euthanized upon completion of the treatment with methoxyflurane. Necropsy examination of the carcasses was performed immediately after sacrifice. None of the animals exhibited any clinically abnormal signs. There were no abnormal signs observed during necropsy. High doses of an iodide/iodate drug do not cause acute toxicity. Example 8 Female Sprague-Dawley rats (a total of 44) weighing 200-250 grams were purchased from Charles River Canada, Inc. (Quebec, Canada). Rats were housed individually in stainless steel wire mesh-bottomed rodent cages equipped with an automatic watering system. The environment was controlled at 21°±3° C., 50±20% relative humidity, 12 hours light, 12 hours dark and 10-15 air changes were made per hour. Animals were fed Remington iodine-deficient diet #170360 (Teklad, Madison, Wis.) ad libitum. Perchlorate-treated (400 mg/dL NaClO 4 ) municipal tap water was provided ad libitum for the first five days of captivity. One group of rats received a normal diet (Teklad Certified Rodent Diet (W) #8728) and municipal tap water. All animals were then allowed to acclimate to their environment for two weeks prior to the start of the experiment. Each day for the five days preceding the initiation of testing, animals received estrogen (25 ug of 17-βestradiol) suspended in 100 ul of sesame oil injected IM. During the 2 week experiment estrogen (2.5 ug 17-βestradiol) suspended in 100 ul of sesame oil was injected daily. Vaginal smears were taken every other day to insure that rats achieved constant estrus throughout the experiment. Molecular iodine was generated in situ in the rats by gavage of an aqueous solution that contained sodium iodide and sodium iodate (5/1 molar ratio I - /IO 3 - ) such that essentially 100% of the administered iodide was converted into molecular iodine. Rats were dosed with molecular iodine once daily. Food was removed from the rats each morning and ten hours later, each rat was dosed with 80 ug/kg of molecular iodine. An equivalent dose of iodide (80 ug/kg) was given to a control group of rats. The negative control consisted of rats which were dosed with tap water. Rats were weighed daily. At the end of the 2 week study rats were sacrificed and microscopic sections of the mammary gland tissues were stained with hematoxylin and eosin prior to being read by a pathologist. Mammary tissue was scored according to the methods described by Eskin et al. (Biological Trace Element Research, 1995, Volume 49, pages 9-18). Four groups of animals were examined: (1) normal diet without perchlorate treatment; (2) iodine deficient with water gavage; (3) iodine deficient with iodide gavage; and (4) iodine deficient with iodine gavage. Each group contained 10 animals. There were small but statistically significant differences in the body weights of the different groups at the start and end of the experimental treatments. However, all of the body weights were within the normal range. The average weight for the four Groups were as follows (1) 208±5.6 at start, 237±7.4 at end; (2) 212±6.3 at start, 239±6.8 at end; (3) 214±6.5 at start, 235±7.1 at end; and (4) 216±6.6 at start, 241±6.9 at end. The mammary tissue was graded for lobular hyperplasia, secretions, periductal fibrosis, and fibroadenomatous changes. The scoring system for lobular hyperplasia, secretions, periductal fibrosis graded as positive only those animals showing moderate to severe conditions. Microscopic fibroadenomata were identified in some samples and quantified. The results of this histological grading are shown below in tabular form. ______________________________________Histologic Grading of Mammary Tissue Lobular Periductal Fibro-Treatment Group hyperplasia Secretion fibrosis adenomata______________________________________Normal Diet 0/10 0/10 0/10 0/10Iodine deficient 4/10 2/10 10/10 3/10(water gavage)Iodine deficient 4/10 4/10 6/10 4/10(iodide gavage)Iodine deficient 2/10 3/10 4/10 1/10(iodine gavage)______________________________________ Iodine deficiency has been shown to alter the structure and function of the mammary glands of rats, especially the alveolar cells. When stimulated by estrogen, either physiologically or externally, the mammary glands appear to be highly sensitive to iodine deprivation. The dysplasia and atypia caused by iodine deficiency in the mammary glands has been shown in extensive trials on humans to be reversible by iodine treatment. The rat model has been used by several researchers as a model of fibrocystic breast syndrome in humans. The group of rats that received the normal diet did not present any abnormal indications. The mammary tissue of the rats on the iodine deficient diet who received a water gavage showed atypical mammary tissue indicative of fibrocystic breast syndrome caused by an iodine deficiency. The iodine deficient rats who received an iodide gavage displayed increased secretion and fibroadenomata. This increase in mammary tissue secretion and mammary tissue fibroadenomata associated with iodide treatment has been previously observed in experiments by Eskin et al. (Biological Trace Element Research, 1995, Volume 49, pages 9-18). In contrast to iodide, gavage with the iodide/iodate mixture (i.e., iodine gavage) reduced the incidence of hyperplasia, secretion, periductal fibrosis and fibroadenoiata. This indicates that in situ generation of molecular iodine can reverse fibrocystic breast syndrome. The results of this experiment confirm that the in situ generation of molecular iodine is an effective modality for treatment of fibrocystic breast syndrome and other iodine deficiency disease states. Example 9 A granulation incorporating iodide anion and iodate anion was prepared and its stability was evaluated at 40° C. In a Kitchen Aid mixer the following chemicals were added: 100 ml deionized water; 1.0 gram of sodium iodate; 3.63 grams of sodium iodide; 5.0 grams of tribasic sodium phosphate; and a drop of sodium hydroxide. The materials were mixed well until they were blended. Twenty five grams of hydroxypropylmethyl cellulose was added and the material was blended until it was uniform. An additional 450 grams of microcrystalline cellulose was slowly added while mixing. This granulation was passed through a number 5 sieve and then dried in a vacuum over at 50° C. After drying the material for 12 hours it was passed through a number 20 sieve. Forty five samples of one gram of the dried granulation were weighed into glass vials and then placed in an oven at 40° C. Three samples was withdrawn approximately each week for three months and the amount of thiosulfate titratable iodine was determined after dissolution in 1 liter of simulated gastric fluid. The results of these measurements are shown below in tabular form. __________________________________________________________________________Thiosulfate Titratable Iodine Generated by Iodide/Iodate Granulationversus Time at 40° C.__________________________________________________________________________Day Number 1 7 14 21 30 37 44 51 60 67 74 81 88 95mg per sample 8.7 8.6 8.7 8.7 8.8 8.8 8.7 8.6 8.7 8.7 8.6 8.8 8.7 8.6__________________________________________________________________________ Example 10 A solution of sodium iodate was prepared at a concentration of 5 millimolar in 200 ml of SGF (without pepsin) in a Teflon-lined screw-top glass bottle. A concentrated solution of ascorbic acid was added dropwise to this solution through a tube. The concentration of iodide (determined by ISE) and free molecular iodine (determined potentiometrically) was determined after each addition of ascorbic acid. The electrodes used for the iodide and free molecular iodine measurements were contacted through air-tight hole fabricated in the top of the Teflon-lined container. The concentration of molecular iodine increased in a nearly linear fashion as a function of the amount of ascorbic acid added until its concentration reached a maximum of 2.38 millimolar. After the molecular iodine reached a maximum, its concentration decreased as the concentration of ascorbic acid increased. No iodide was detected until the concentration of molecular iodine reached 2.38 millimolar. The concentration of iodide increased with increasing ascorbic acid until it reached a maximum of 4.82 millimolar at which it remained constant regardless of any increase in ascorbic acid. The experiment was repeated using another oxidant-reductant pair. Iodate and sodium thiosulfate were substituted for iodate and ascorbic acid. The exact same experiment was repeated except that concentrated sodium thiosulfate was added dropwise to the sealed container. Once again the concentration of molecular iodine reached a maximum value of 2.26 millimolar and then decreased. As the concentration of molecular iodine decreased from its maximum value, the concentration of iodide increased from 0 to 4.7 millimolar. Example 11 The ratio of molecular iodine to total iodine was determined as a function of the ratio of iodide anion to iodate anion in SGF (without pepsin). The following measurements were made to determine the presence of different iodine species: thiosulfate titratable iodine, potentiometric analysis of molecular iodine and ion selective electrode determination of iodide anion. It was found that essentially all of the input mass of iodine atoms was accounted for by measuring these three species. Triiodide and other polyiodides were calculated from the thiosulfate values and molecular iodine values. The ratio of molecular iodine to total iodine was determined by dividing the mass of molecular iodine by the sum of the mass of iodide, molecular iodine and triiodide. The ratio by weight of iodide anion to iodate anion was varied from 0.5 to 8. It was observed that the ratio of molecular iodine to total iodine varied as shown in tabular form below. __________________________________________________________________________Ratio of Molecular Iodine to Total Iodine as a Function of theIodide/Iodate Ratio (wt)__________________________________________________________________________Ratio iodide/iodate (wt) 0.5 1 2 3 4 5 6 7 8Ratio molecular iodine 0.52 0.72 0.89 0.97 0.92 0.76 0.65 0.56 0.50__________________________________________________________________________ Additional experimentation indicated that a weight ratio for the reactants, iodide and iodate, of about 0.78 (I - /IO 3 - ) yielded a ratio of molecular iodine to total iodine of 0.65. Example 12 Female Sprague-Dawley rats weighing 200-250 grams were purchased from Charles River Canada, Inc. (Quebec, Canada). Rats were treated exactly as described in Example 8 and were subjected to identical procedures with respect to perchlorate and estrogen dosing. Each rat was dosed by gavage of an aqueous solution that contained sodium iodide and sodium iodate (5/1 molar ratio I - /IO 3 - ) such that essentially 100% of the administered iodide and iodate was converted into molecular iodine upon contact with the stomach fluids. Rats were dosed with molecular iodine once daily. Food was removed from the rats each morning and ten hours later, each rat was dosed with one of three concentrations 0.0010, 0.010 or 0.10 mg/kg of molecular iodine. A dose of iodide (100 ug/kg) was given to a control group of rats. The negative control consisted of rats which were dosed with tap water. At the end of 4 weeks rats were sacrificed and microscopic sections of the mammary gland tissues were stained with hematoxylin and eosin prior to being read by a pathologist. Mammary tissue was scored as described in Example 8. Six groups of animals were examined: groups 1-3 received daily doses of one of three concentrations of molecular iodine; (4) received the normal diet without perchlorate treatment; (5) received the iodine deficient diet with a water gavage; and (6) received an iodine deficient diet and were dosed with iodide (100 ug/kg). All of the rats body weights were within the normal range throughout the study. The mammary tissue was graded for lobular hyperplasia, secretions, periductal fibrosis, and fibroadenomatous changes as described in Example 8. Microscopic fibroadenomata were identified in some samples and quantified. The results of this histological grading are shown below in tabular form. ______________________________________Histologic Grading of Mammary Tissue Lobular hyper- Periductal Fibro-Treatment Group plasia Secretion fibrosis adenomata______________________________________Molecular Iodine 1 ug/kg 4.10 6/10 6/10 4/10Molecular Iodine 10 ug/kg 2/10 4/10 4/10 1/10Molecular Iodine 100 ug/kg 2/10 3/10 2/10 1/10Normal Diet 0/10 0/10 0/10 0/10Water Gavage 4/10 1/10 10/10 5/10Iodide Gavage 4/10 5/10 5/10 3/10______________________________________ Rats maintained on a normal diet did not exhibit clinically abnormal signs. As expected, rats on an iodine deficient diet that did not receive treatment (water gavage) presented mammary tissue whose histology is consistent with FBS. Daily treatment with iodide (100 ug/kg) did not substantially alleviate the formation of fibroadenomata. Daily treatment with molecular iodine at a concentration of 1 ug/kg did not substantially alleviate the formation of fibroadenomata and periductal fibrosis. Daily treatment with molecular iodine at a concentration of 10 and 100 ug/kg substantially reduced the formation of fibroadenomata and periductal fibrosis. The invention is not to be construed as limited to the above examples. Other embodiments are within the scope of the following claims.

The invention is a method of administering therapeutic iodine for treating a disorder in a mammal. The invention comprises a step of feeding said mammal an effective amount of an oxidant for an iodine species and an iodine reductant which will cause oxidation-reduction reactions upon contact with the gastric juices present in the stomach of the mammal. This is done such that molecular iodine is generated in vivo at a ratio of molecular iodine to total iodine of above at least about 0.65. The invention also discloses a non-aqueous pharmaceutically acceptable carrier with said oxidant and reductant having the ability to cause oxidation-reduction reactions upon contact with the gastric juices present in the stomach of said mammal and in an amount sufficient to generate molecular iodine, in vivo, at a ratio of molecular iodine to total iodine of above at least about 0.65.

BACKGROUND [0001] (1) Field [0002] The present invention relates generally to electrical components and, more particularly, to low leakage electrical joints and wire harnesses for simplifying the electrical infrastructure associated with solar energy utilities. The low leakage electrical joints include fused wires that have been sealed, encased and configured to plug into other joints to form wire harnesses. [0003] (2) Related Art [0004] The problems associated with the world's dependence on non-renewable resources have resulted in increased attention to so-called alternative energy, such as solar and wind power. As a result, small-scale production of alternative energy, for example by installing residential solar heaters or wind turbines, has become more popular. While these actions may provide psychological and possible long-term financial benefits, their actual effect on society's consumption of non-renewable resources is minimal. In short, permanent and significant changes necessitate the implementation of alternative energy generation on a large-scale utility basis. [0005] Utility scale production of solar energy, however, is often considered financially imprudent given the high cost of materials, know-how, and labor. For example, conventionally wiring solar panels typically requires a qualified electrician to measure, cut, connect and crimp wires on site, by hand, between each individual solar panel's junction box and the combiner box, and the combiner box and master fuse box. In addition, this extensive wiring often further requires the labor and expense of troubleshooting and repairing. [0006] In addition, conventional solar utility infrastructures often have technical shortcomings that further drive up the price. For example, conventional wire connections leak precious energy, thereby decreasing the efficiency, and increasing the price, of the system. [0007] Accordingly, the interests of being environmentally responsible often conflict with the financial realities of building and maintaining a solar energy plant. [0008] Thus, there remains a need for components for use in solar plants that decrease the materials, know-how and/or labor associated with building and maintaining the electrical infrastructure. [0009] There also remains a need for components for use in solar plants that decrease the cost associated with the materials, know-how and/or labor in building and maintaining the electrical infrastructure of a solar plant. [0010] A need also exists for components that decrease electrical leakage. Ideally, these low leakage components are relatively simple, safe and inexpensive to manufacture, transport and use. [0011] A method of making the aforementioned components is also needed. SUMMARY OF THE INVENTIONS [0012] The present inventions are directed to low leakage electrical joints and wire harnesses for simplifying the electrical infrastructure associated with solar energy utilities. The low leakage electrical joints include insulated photovoltaic wire which has been partially stripped, with the portion of exposed wire welded to a portion of exposed wire on another, separate photovoltaic wire. The section encompassing the exposed wire and weld is coated in a synthetic rubber sealant and allowed to cure. After curing, the section of exposed/fused/sealed wire is encased in a molded polypropylene material including a UV stabilizing agent. These resulting joints can be shaped as T's, crosses or Y's, and be fitted with various lengths of insulated wire, female connectors and/or male connectors for attachment to at least one other joint. Wire harnesses can be assembled using a plurality of these joints, usually with lengths of insulated wire there between. [0013] The nature of the present inventions will become apparent to those skilled in the art after reading the following description of the preferred embodiment when considered with the drawings. BRIEF DESCRIPTION OF THE DRAWING [0014] FIG. 1 schematically represents the electrical infrastructure of a solar energy system; [0015] FIG. 2 illustrates a wire harness, including enlarged male and female connectors; [0016] FIG. 3 is a front view of a tee joint; [0017] FIG. 4 is a front view of a cross joint; [0018] FIG. 5 is a front view of a y joint; [0019] FIG. 6 is a perspective view of a tee joint encasement; [0020] FIG. 7 is a perspective view of a cross joint encasement; [0021] FIG. 8 is a perspective view of a y joint encasement; and [0022] FIG. 9 depicts some steps in constructing a tee joint. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] In the following description, like reference characters designate like or corresponding parts throughout the several views. It should be understood that the illustrations are for the purpose of describing a preferred embodiment of the inventions and are not intended to limit the inventions thereto. [0024] FIG. 1 provides the general scheme of the electrical infrastructure of the present inventions. Each solar collector has junction box, with each junction box wired to a central combiner box via wire harness 10 . The central combiner box bundles the output into trunk 15 , which goes into the master fuse box. Electricity from the master fuse box travels to the inverter, then transformer, then power line. [0025] Referring to FIG. 2 , wire harness 10 is constructed of a plurality of joints, potentially including tee joint 20 , cross joint 22 and/or y joint 24 (not shown in FIG. 2 ). The joints are connected one to another via insulated wire 30 , and include female connector 26 or male connector 28 at various junctions. It should be understood that a multitude of electrical configurations may be achieved by varying the number and choice of connectors and joint types, and that FIG. 2 merely represents the preferred configuration for coupling a plurality of junction boxes to a combiner box. [0026] Tee, cross and y joints of FIGS. 3 , 4 , and 5 respectively are constructed similarly with respect to each other, but vary according to shape and function. Using tee joint 20 as an example, joints comprise spokes 58 protruding from central hub 56 , terminating in female connector 26 or male connector 28 . Length of spokes 58 may be elongated by including longer lengths of insulated wire 30 . Central hub 56 includes external tee encasement 60 , which defines channels 54 (best shown in FIG. 6 ) through which insulated wire 30 protrudes outwardly (best shown in FIG. 2 ). Outwardly protruding insulated wire 30 may not be visible if connector 26 , 28 , which is attached to insulated wire 30 , abuts channel, as shown in FIG. 3 . External tee encasement 60 preferably defines securing apertures 52 through which zip ties or other fasteners may be employed to secure tee joint 20 or wire harness 10 to prevent unwanted movement during or subsequent to installation. Also, informational window 45 is preferred for displaying manufacturer, part number, technical specifications and the like. [0027] Beneath tee encasement 60 lies sealed wire 38 , which collectively includes segments of exposed wire 34 , portions of which are welded wire 36 , covered in sealant 40 . This construction is best exemplified in the scheme set forth in FIG. 9 wherein it should be understood that encasement 50 is depicted, but similar construction applies employing tee encasement 60 , cross encasement 62 or y encasement 64 . [0028] Referring specifically to FIG. 9A , tee joint 20 is constructed by taking two separate insulated wires 30 , and stripping off a portion of insulation 32 to reveal exposed wire 34 , as shown in FIG. 9B . Preferably, the trunk wire would be window stripped to expose an internal section of wire, whereas a branch wire would be end stripped. Preferably insulated wire 30 includes copper, and most preferably is a 8, 10 or 12 AWG photovoltaic wire which is certified by UL and/or TUV for use with solar applications to carry DC current up to 1000V. A branch wire may be the next smaller size of wire as it will not carry as much current. Preferably insulation 32 is constructed of crosslinked polyolefin copolymer and is 1.7 mm thick. One preferred example of a commercially available and suitable insulated wire 30 is Betaflam Solar from Leoni Studer AG of CH-4658 Daniken, Switzerland. As shown in FIG. 9C , exposed wires are resistance welded to form welded wire 36 , with the end of the branch wire preferably welded to the center of the trunk wire. Resistance welding is preferably accomplished by using two copper electrodes which pass a high current through the joint causing the wires to be fused to form a solid material at the joint. [0029] Fused wires 36 and any remaining exposed wires 34 are completely coated with sealant 40 , as shown in FIG. 9D . Preferably sealant 40 is a synthetic rubber, more preferably a silicone-based rubber sealant, with Plasti Dip® multi-purpose rubber coating from Plasti Dip International of Blaine, Minn. being the most preferred. Preferably sealant 40 is applied with a small brush, in a volume adequate to cure at a thickness of approximately 20 mils. Sealant 40 is permitted to completely cure, preferably at room temperature for approximately 4 hours. Once cured, the assembly is placed in a mold according to methods known in the art, and overmolded to form encasement 50 , as shown in FIG. 9E . Encasement 50 is preferably formed using a polypropylene material, most preferably including a UV stabilization agent. The preferred polypropylene material is RTP 199 from RTP Imagineering Plastics of Winona, Minn. [0030] Slight modifications would be necessary to form cross or y joints 22 and 24 , particularly with respect to stripping and fusing wire. Moreover, additional steps would be required to secure female and male connectors 26 and 28 to segments of insulated wire 30 . Namely, the wire will be cut, stripped and terminated with the applicable terminal, then a rubber boot will be installed to insulate the terminal. As assembled, all electrically live components of wire harness 10 , including insulated wire 30 , exposed wire 34 , sealed wire 38 and connectors 26 , 28 are all in electrical communication one with another. [0031] In use, an installer would simply select the proper wire harness 10 , preferably based on labeling or packaging, and connect the appropriate parts (ie female connectors 26 to junction boxes of solar collectors, and male connector 28 to combiner box). Wire harnesses of popular specifications can be manufactured in bulk, or specially assembled in advance if lesser quantities are required, or constructed on site as required by employing pre-assembled joints 20 , 22 , 24 , connectors 26 , 29 and insulated wire 30 . [0032] In addition to the novel construction and substantial savings with respect to materials, know-how and labor, the present inventions provide exceptionally low leakage compared to conventional solar connectors. Specifically, both the MC Solarline 1 connector from Multi-Contact AG of Stockbrunnenrain, Switzerland, and the Solarlok connector of Tyco Electronics in Speyer, Germany, leak 1 mA (milliamp). In contrast, tee, cross and y joints 20 , 21 and 24 of the present inventions leak less than 50 nA (nanoamps). This is well below the maximum industry standard of 50 mA, as set forth by the solar industry leader. [0033] Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.

Low leakage electrical joints and wire harnesses for simplifying the electrical infrastructure associated with solar energy utilities are disclosed. The low leakage electrical joints include fused wires that have been sealed, encased and configured to plug into other joints to form wire harnesses. The wire harnesses are particularly well suited for coupling a plurality of solar collector junction boxes to a combiner box.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to German Patent Application No. DE 10 2010 016 918.8, filed on May 12, 2010 and European Patent Application No. EP 10 401 128.3, filed on Aug. 3, 2010, both of which are hereby incorporated by reference herein in their entireties. FIELD [0002] The present invention relates to an automatic warewashing machine with a door that can be held in the closed position by a force-locking or force- and form-locking latching mechanism. BACKGROUND [0003] In automatic warewashing machines having a force-locking or force- and form-locking door lock which is disposed on the washing chamber side and may also be referred to as “pull-type release lock”, it is desirable to provide a unit which allows the door to be automatically opened by a few centimeters, either by the automatic warewashing machine in a cycle-dependent manner or by the user. Cycle-dependent opening is generally performed shortly before the end of the cycle to assist in the drying process. An automatic door opening system should always be made available to the user when there is no handle that would allow the user to pull the door open. This is the case, for example, in handle-free, fully integratable appliances. [0004] A dishwasher having an automatic door-opening system is described, for example, in DE 10 2005 028 449 A1. In this appliance, the latching mechanism is mounted on the door and adapted to engage with a latch keeper secured on the washing chamber. In order to allow the door to be automatically opened to an ajar position in a program-controlled manner, the latch keeper is mounted to a closing plate which is movable by a motor. Upon receipt of a signal from the appliance controller, the motor extends the closing plate, and thus the latch keeper. In this manner, the door is opened to an ajar position, but kept in a latched state. In order to open the door, a handle is pulled up, thereby rotating a latching member to a position where it is no longer held by the latch keeper. [0005] In document WO 2009/146 874 A1, too, the latch keeper mounted on the washing chamber is moved by a driving mechanism to open the door to an ajar position. Here, the driving mechanism is implemented as a spring which is tensioned as the door is opened further. [0006] The aforementioned automatic door opening devices can only be used in automatic warewashing machines where the latching mechanism is mounted in the door and the latch keeper is disposed on the washing chamber or housing of the machine. This results in disadvantages. [0007] For example, displays or controls cannot be mounted in the middle of the door, and the space actually available for such components is limited. It is necessary to use printed circuit boards which have cutouts for the latching mechanism and, therefore, are expensive to manufacture. In addition, in the case of door-mounted latching mechanisms, the door must have a cutout, which may lead to ingress of moisture and damage to the electronics. [0008] U.S. Pat. No. 4,951,693 also describes a dishwasher having an automatic opening system. Here, a spring mechanism becomes loaded as the door is closed, and the door is latched in the closed position. Upon release of the latch by a solenoid, the spring mechanism automatically opens the door. Additional springs hold the door in a partially open position. [0009] A spring mechanism for opening the door to an ajar position is also used in a dishwasher as described in EP 2 210 547 A1, where a pull-type release lock is used as the latching mechanism. [0010] During operation, the washing chamber of automatic warewashing machines should be closed liquid-tight. To this end, the access opening of the washing chamber is surrounded by a seal against which the door presses. The latching mechanism must be capable of counteracting the force with which the seal presses against the door in the opening direction. If the latching mechanism is suddenly released, such as in U.S. Pat. No. 4,951,693 A, or is overcome by spring force (see EP 2 210 547 A1), then a sudden acceleration occurs. Door springs are provided to counteract this acceleration. However, such door springs may be misadjusted or may even break. In such case, the door drops down from the closed position to the horizontal and may injure persons as it drops. Small children present in the pivoting range of the door might even be struck dead. [0011] German Patent Application No. DE 10 2008 058 257 A1 describes an automatic washing machine where the latching mechanism is mounted in the door. This automatic washing machine is also provided with a system for automatically opening the door to an ajar position. In this system, part of the latching mechanism is moved out of the body of the machine by a motor. The door remains latched until a release device is actuated. [0012] DE 20 2007 006 818 U1, WO 2009/106 292 A1, EP 1 935 313 A1, which are incorporated by reference herein in their entireties, describe appliance doors openable by knocking on a decorative front panel of the door. SUMMARY [0013] In an embodiment, the present invention provides an automatic warewashing machine including a washing chamber, a hinged door configured to close the washing chamber, and a force-locking latching mechanism configured to hold the door in a closed position and release the door in response to a pulling force. The force-locking latching mechanism is disposed on the washing chamber or on a body enclosing the washing chamber. A door opening system is also included and has a push-open unit configured to automatically open the door to at least an ajar position. The push-open unit includes a motor-driven push-type opening bar. BRIEF DESCRIPTION OF THE DRAWINGS [0014] Exemplary embodiments of the present invention are described in more detail below and are schematically shown in the drawings, in which: [0015] FIG. 1 is a perspective view of a dishwasher, shown with the appliance door in an ajar position; [0016] FIG. 2 is an enlarged view showing a detail of FIG. 1 ; [0017] FIG. 3 is a detailed top view of a push-open unit, shown with a housing cover removed; [0018] FIG. 4 is an exploded view showing structural details of the push-open unit; [0019] FIG. 5 is a perspective view showing the underside of a push-type opening bar; [0020] FIG. 6 is a plan view showing the underside of the push-type opening bar; [0021] FIG. 7 is a view of the underside of the push-type opening bar, showing various points along the guide track which are indicative of discrete states; [0022] FIG. 8 is a view of an alternative embodiment of a freewheel; and [0023] FIG. 9 is a detail view of the inner sleeve of the freewheel shown in FIG. 8 . DETAILED DESCRIPTION [0024] In an embodiment, the present invention provides an automatic warewashing machine which overcomes the aforedescribed disadvantages and has an opening system that is simple in design and easy and safe to operate. [0025] Automatic slow opening is made possible by mounting the latching mechanism on the washing chamber or on the body and providing the push-open unit with a motor-driven push-type opening bar. In this manner, the acceleration of the door during opening is kept low. [0026] In order to provide even greater protection against excessively rapid opening of the door, the door may be retainable on the push-type opening bar by a magnetic coupling. [0027] Furthermore, in an embodiment, the push-open unit of the present invention allows the appliance door opening to be opened at different speeds. This is advantageous in particular in the variant of a handle-free, fully integrated dishwasher. The appliance door should be opened quickly, for example, when a request for opening the door is made by knocking on the decorative front panel of the appliance door. In contrast, at the end of a cycle, the door may be opened relatively slowly. In this manner, the drying of the items washed is significantly improved (see U.S. Pat. No. 5,901,746 A, which is incorporated by reference herein in its entirety). This variation in the opening speed is made possible by the motor drive of the push-type opening bar, for which different motor variants can be used. Conveniently, a double-coil synchronous motor is used in the case of conventional dishwashers, while in the case of fully integratable dishwashers, an extra low voltage DC motor is used. As for the positioning of the motor, it is advantageous if the axis of rotation of the motor shaft extends parallel to the direction of movement of the push-type opening bar. In automatic warewashing machines of conventional design, sufficient space for accommodating a motor is available only laterally between the washing tub and the housing wall. Therefore, in particular elongated motors are preferably only be mounted in the aforesaid position. [0028] Another advantage of embodiments of the present invention resides in the space gained on the door, which allows a deeper handle recess to be formed thereon. Besides, one locks design can be used both for appliances having an exposed control panel and for fully integrated variants. Moreover, there is no need to modify the structure of the latching mechanism for automatic warewashing machines that are not equipped with an automatic opening system. A latching mechanism having a simple design includes a resiliently mounted roller which engages with a lock catch 22 provided on the door. Further structural advantages result from the fact that the latching mechanism and the push-open unit are two independent assemblies which, therefore, can be installed and inspected independently of each other. It is also advantageous if the latching mechanism is arranged in a corner formed by the push-type opening bar and a driving shaft acting upon the push-type opening bar. In this manner, a space-saving design is achieved. The push-type opening bar and the driving shaft may be disposed in an angled housing. [0029] FIG. 1 shows, in a perspective view, a dishwasher 1 with an appliance door 2 in an ajar position, while FIG. 2 shows an enlarged portion of FIG. 1 . In these figures, the cover of dishwasher 1 is removed to show the components of the present invention located therebelow. Door 2 closes front opening 12 of a washing chamber 10 . A latching mechanism centrally disposed on the washing chamber side and hereinafter referred to as door lock 3 holds door 2 in the closed position. Dishwasher 1 further has an automatic opening system, hereinafter referred to as push-open unit 5 . Door lock 3 is equipped with a resiliently supported roller 30 which engages behind a lock catch which is located opposite on the door and takes the form of a projection 22 . Push-open unit 5 is disposed adjacent and to the left of door lock 3 on the washing chamber side in an angular space defined by housing parts 500 and 502 , which are described elsewhere herein. The push-open unit may also be mounted on the right-hand side. Mounting push-open unit 5 on the right-hand side is advantageous in the case of narrow dishwashers 1 . [0030] Advantageously, door lock 3 is disposed centrally in a U-shaped strengthening channel 14 of washing chamber 10 of dishwasher 1 . Push-open unit 5 and door lock 3 are not connected to each other and, therefore, constitute two independent assemblies, which also simplifies the development of design variants. For example, push-open unit 5 can also be used in dishwashers 1 having a force-locking door lock 3 provided on the door. Further, door lock 3 may also be used without a push-open unit 5 if required, for example, in inexpensive dishwashers 1 . If the aforementioned advantages provided by the separate design of door lock 3 and push-open unit 5 are not considered essential, these two assemblies may also be combined into one unit. [0031] FIG. 2 illustrates further structural details of embodiments of the present invention. For example, push-open unit 5 includes a push-type opening bar 504 which is mainly moved by motor 506 , which is mounted laterally between dishwasher side wall 16 and the radial transition from the cover to the side wall of the washing chamber. Preferably, the axis of rotation of the shaft (indicated in FIG. 3 by a dot-dash line 508 ) of motor 506 extends parallel to the direction of movement of push-type opening bar 504 . This advantageously allows different types of driving mechanisms (synchronous motor, DC motor) to be used in push-open unit 5 . DC motors, in particular, are relatively long compared to their diameter. Here, it is only the above-described parallel mounting position within dishwasher 1 that provides a sufficient degree of freedom for installation. Moreover, this mounting position makes it possible to develop design variants. It is primarily the above-described design variant of a handle-free, fully integrated dishwasher 1 that takes advantage of a DC motor to achieve a rapid opening movement. Normally; i.e., when the purpose is to automatically open appliance door 2 in order to assist in the drying process, motor 506 is designed as a double-coil synchronous motor. Since such a motor operates at a low speed of about 250 or 500 rpm, appliance door 2 is opened relatively slowly in about 15 to 20 seconds, provided the transmission is suitably designed for this purpose. The advantages of such synchronous motors are that they feature very low operating noise levels, are inexpensive, and allow AC mains powered operation, which permits relatively easy control by the electronic cycle control. If there is a requirement for a higher door opening speed, such as, for example, to open the door of a handle-free, fully integrated dishwasher 1 toward a user, it is preferred to use an extra low voltage DC motor in place of the double-coil synchronous motor. At typical speeds of 2500 to 5000 rpm, the dishwasher door is then opened in 1.5 to 2 seconds. Preferably, the driving mechanism is designed such that push-open unit 5 can be operated with both a double-coil synchronous motor and an extra low voltage DC motor using the same transmission stages 510 (shown in FIG. 3 ) and without requiring any modifications. [0032] Further details of push-open unit 5 are shown in the top view of FIG. 3 , in which housing cover 502 is removed. [0033] The torque of motor 506 is transmitted to push-type opening bar 504 by transmission stages 510 and a shaft 512 disposed at a right angle relative to motor shaft 508 and to the direction of movement of push-type opening bar 504 . Transmission stages 510 , on the one hand, perform a gear reduction function; i.e., a speed-reducing function, and, on the other hand, they deflect the axis of rotation at an angle of 90° by means of a bevel gear or worm gear stage. At its left end; i.e., at its motor end, shaft 512 is supported directly in lower housing part 500 . At its right end; i.e., at the opening bar end, shaft 512 is supported in lower housing part 500 via end shield 514 . In FIG. 4 , reference numeral 516 denotes the end of shaft 512 that is rotatably received in end shield 514 . Push-type opening bar 504 and shaft 512 form two right angles 518 and 520 , which are also present in housing parts 500 and 502 . This is where door lock 3 is located. [0034] FIG. 4 illustrates further structural details of embodiments of the present invention in an exploded view. [0035] Shaft 512 has mounted thereon a freewheel 522 ( FIG. 3 ), which is formed by an inner sleeve 524 , an outer sleeve 526 , and a movable slide member 528 ( FIG. 4 ). Inner sleeve 524 is non-rotatably connected to shaft 512 and has a helical groove 530 on its surface, which moves slide member 528 during relative motion (rotation) between shaft 512 and outer sleeve 526 . Helical groove 530 is bounded by a left stop 532 and a right stop 534 (as seen from a position in front of the appliance). Outer sleeve 526 concentrically surrounds shaft 512 and, consequently, is rotatably supported thereon. The outer sleeve has two guide grooves 536 arranged parallel to the shaft and adapted to receive guide ribs 538 of slide member 528 . Due to the aforedescribed arrangement, slide member 528 reciprocates between the two stops 532 and 534 depending on the direction of rotation of shaft 512 and outer sleeve 526 . In this manner, a freewheel 522 is created between shaft 512 and outer sleeve 526 , since the rotation of shaft 512 , respectively of inner sleeve 524 , is not transmitted to outer sleeve 526 while the slide member moves. The number of freewheeling revolutions can be varied by the length of helical groove 530 . Transmission of rotational movement from shaft 512 to outer sleeve 526 does not take place until slide member 528 reaches left stop 532 or right stop 534 (depending on the direction of rotation). [0036] A double pinion 542 is mounted on an extension 540 of outer sleeve 526 ( FIG. 4 ) and meshes with lateral toothed tracks 544 formed on the underside of push-type opening bar 504 (see FIGS. 5 through 7 ). Double pinion 542 is driven by outer sleeve 526 of freewheel 522 via meshing facial toothings 546 . Facial toothings 546 are pressed together by a compression spring 548 via a drive dog 550 and double pinion 542 . In this manner, a mechanical safety coupling; i.e., a slip coupling, is created. The torque transmittable by the slip coupling can be adjusted via the helix angle of facial toothings 546 and the force of compression spring 548 . A torsion spring 552 is mounted on a spring sleeve 554 concentrically around compression spring 548 between end shield 514 and drive dog 550 . The function of this torsion spring will be explained later herein. [0037] Double pinion 542 drives push-type opening bar 504 which, in order to open appliance door 2 , presses into the rabbet of inner door panel 20 , releasing roller 30 of door lock 3 from lock catch 22 . The underside of push-type opening bar 504 has a guide track 556 formed between lateral toothed tracks 544 . Guide track 556 is engaged by a locking pin 558 formed on an anchor member 560 (see FIG. 4 in conjunction with FIG. 5 ). Anchor member 560 is pivotally mounted in a receiving formation 562 in lower housing part 500 and has two functions. First, it retains push-type opening bar 504 in particular positions via locking pin 558 (in this regard, see the description of FIG. 7 in section “Sequence of Operation”). Second, it actuates a microswitch 570 via an arm 564 when push-type opening bar 504 has moved to its end position in housing ( 500 , 502 ). Microswitch 570 is polled by a controller of dishwasher 1 . Preferably, if motor 506 is a synchronous motor or a double-coil synchronous motor, all further positions of push-type opening bar 504 that are different from its rear end position are approached in a time-controlled manner. Alternatively, in particular if motor 506 is an extra low voltage DC motor, all further positions of push-type opening bar 504 that are different from its rear end position can be sensed by one or more additional microswitches. [0038] All other functions provided by the interaction of locking pin 558 with guide track 556 on the underside of push-type opening bar 504 are also described below. [0039] Appliance door 2 is opened by about 100 mm as push-type opening bar 504 is moved out. Door 2 is magnetically held in this state. To this end, a ferromagnetic metal insert 566 is attached to push-type opening bar 504 , and a magnet 24 is disposed at a corresponding position behind the inner door panel so as to cooperate with one another. During automatic opening of appliance door 2 , the magnetic holding means ensure that the door is retained in the event it has a tendency to open by itself. This may be necessary, for example, if the door springs are set too weak or are broken. Once the ajar position is reached during automatic opening, the user can fully open the door for unloading and loading of dishware. After the magnetic holding means are separated, push-type opening bar 504 should in any case be returned to the retracted position, even if the user has already turned off dishwasher 1 , disconnecting it from the mains power supply. Otherwise there would be a risk of getting injured by the extended push-type opening bar 504 or of damaging the same. In addition, the extended push-type opening bar would hinder the unloading and unloading of dishware. [0040] In order to achieve this, torsion spring 552 located on spring sleeve 554 is tensioned as push-type opening bar 504 is moved out; i.e., during the automatic opening of the door. To this end, spring 552 is secured at its two ends in receptacles on drive dog 550 and end shield 514 . As appliance door 2 is fully opened by the user, the aforedescribed magnetic holding means cause push-type opening bar 504 to be pulled out up to a front limit stop. Then, push-type opening bar 504 detaches from door 2 and is retracted by torsion spring 552 . This also works when dishwasher 1 is off, which makes it possible to avoid standby consumption, which would be required in alternative, electric motor based approaches for the then required control electronics. Spring sleeve 554 allows compression spring 548 and torsion spring 552 to be arranged on shaft 512 in a space-saving manner and concentrically within one another; i.e., concentrically one over the other. End shield 514 , which is rotatably disposed in lower housing part 500 , serves to support shaft 512 and to adjust the bias of torsion spring 552 . [0041] Push-type opening bar 504 is provided with a resilient stop to allow easy opening of the door by the user during periods when no washing operation takes place, such as in a situation where the washed dishes have been unloaded and new items to be washed need to be loaded. This is achieved by means of a stop spring 572 . The two legs 574 and 576 of stop spring 572 are biasingly clamped between two bearing blocks 578 and 580 . Front leg 574 can be pressed by about 15 mm rearward by stop 582 of push-type opening bar 504 . When the user closes the door, stop 582 of push-type opening bar 504 first contacts front leg 574 , and the lock is at the changeover point. In the further sequence of movements, the user pushes the door by about another 5 mm rearward, and roller 30 of door lock 3 drops behind lock catch 22 . When appliance door 2 is closed, the so-biased push-type opening bar 504 presses with a force of, for example, 25 N from behind against the door, so that the spring force of push-type opening bar 504 counteracts the closure force of door lock 3 , which is 40 N, for example. In this example, the resulting reduced closure force of door lock 3 would be 15 N. Thus, the user can open appliance door 2 particularly easily. When the wash cycle is initiated, the driving mechanism presses push-type opening bar 504 by another 10 mm to the rear end position against the force of stop spring 572 , so that it no longer contacts the door. Now, the full closure force of 40 N is exerted by door lock 3 on door 2 , which is the force required to ensure tightness of the door seal, so that now the washing operation can be started. [0042] A description of the automatic opening sequence and the subsequent closing operation will be given with reference to FIG. 7 . Table 1 below gives a brief overview of this sequence of operation. FIG. 7 is a view of the underside of push-type opening bar 504 , showing the positions of locking pin 558 within guide track 556 . The points denoted by position characters indicate states, while the arrows denoted by position characters indicate transitions between two states. Locking pin 558 is guided in upper guide slot 584 , middle guide slot 586 or in lower guide slot 590 . [0043] During the washing operation, door 2 is closed; push-type opening bar 504 has been retracted to its end position by the driving mechanism formed by motor 506 and transmission stage 510 . There is no contact between door 2 and bar 504 . The driving mechanism is at rest; freewheel 522 is located at left stop 532 . Locking pin 558 is in position A, and arm 564 of anchor member 560 actuates microswitch 570 . To initiate the automatic opening, the driving mechanism is activated, causing push-type opening bar 504 to be released. In this process, stop spring 572 pushes push-type opening bar 504 out of housing 500 and 502 . Arm 564 clears microswitch 570 , and locking pin 558 moves via B to C. In position C, push-type opening bar 504 has moved out 15 mm, which corresponds to the travel of spring 572 . Opening bar 504 initially remains in this position, while freewheel 522 is traversed from left stop 532 to right stop 534 . Once right stop 534 is reached, double pinion 542 moves opening bar 504 further in the forward direction; locking pin 558 moves via position D to position E, changing from upper guide slot 584 to middle guide slot 586 in the process. When arrived there, the driving mechanism is reversed and freewheel 522 is traversed from right stop 534 back to left stop 532 . Once the entire path through freewheel 522 is traversed, the driving mechanism is stopped. Depending on the adjustment of the door springs, door 2 remains in its position, is slightly pulled back by tensioned torsion spring 552 via opening bar 504 , or opens a little further by itself. Accordingly, locking pin 558 either remains in position E, moves to position E.1 (if door 2 is pulled back), or moves to position E.2 (if door 2 opens a little further by itself). Middle guide slot 586 has a bevel 588 at point E.1. When the user presses door 2 closed when in the automatically opened position with push-type opening bar 504 in the extended position, locking pin 558 moves up this bevel as push-type opening bar 504 is pushed in, and then moves through path F. 1 to position G. Because anchor member 560 is freely supported in the region of locking pin 558 , it allows for the lifting of locking pin 558 on the higher, middle guide slot. As path F. 1 is traversed, the torsion spring relaxes, and freewheel 522 is traversed from left stop 532 to right stop 534 . Normally, the user will pull the door further open after the automatic opening operation is completed. In this process, push-type opening bar 504 is initially pulled further out by the magnetic coupling until the locking pin reaches point E.2. Then, the magnetic coupling is disconnected. Tensioned torsion spring 552 then pulls opening bar 504 back into housing 5 , in which process the locking pin moves, via F, from middle guide slot 586 to lower guide slot 590 and to G, where it is held. As opening bar 504 retracts, freewheel 522 is traversed from left stop 532 to right stop 534 . Position G in the middle guide slot is configured as a receptacle in which locking pin 558 is held. Because of this, upon manual opening of the closed door, push-type opening bar 504 is held in this position and prevented from also moving out. Once a new wash cycle is initiated, opening bar 504 is fully retracted again, and locking pin 558 moves via H onto upper guide slot 584 and back to position A. In this process, the freewheel is traversed from right stop 534 to left stop 532 . [0044] FIGS. 8 and 9 show an alternative embodiment of a freewheel 622 . In contrast to the aforedescribed variant, this variant provides protection against the following failure: [0045] Door 2 is pulled down to the horizontal position by its own weight already when in a slightly open state. The weight of door 2 is counteracted by conventional door springs. However, when one or even both door springs are broken, the weight is not or not sufficiently balanced anymore. In this case, door 2 is initially held by torsion spring 552 as push-type opening bar 504 moves out. When at a certain opening angle, the weight of door 2 exceeds the retaining force of spring 552 , the door accelerates its dropping motion. In the first variant of freewheel 522 , the freewheel is traversed from right stop 534 to left stop 532 in this process, and push-type opening bar 504 is fully pulled out up to the stop. The acceleration occurring in this process, and the subsequent sudden deceleration occurring when push-type opening bar 504 reaches the end of its path, may disconnect the coupling between metal insert 566 and magnet 24 . In that case, door 2 continues to drop unbraked to the horizontal position and may injure persons or destroy objects on its way. [0046] To avoid this, the variant of freewheel 622 shown in FIGS. 8 and 9 is latched in its position at right stop 634 . To this end, unlike the first variant, an outer sleeve 626 is non-rotatably fixed to shaft 512 at the drive end. An inner sleeve 624 is partially received within outer sleeve 626 and is rotatably supported on shaft 512 . Inner sleeve 624 merges into an extension 640 having double pinion 542 , compression spring 548 , torsion spring 552 and spring sleeve 554 slidably supported thereon. The drive dog for attachment of torsion spring 552 is here in the form of a hook 650 integrally formed on double pinion 542 . End shield 514 and slide member 528 are not shown here, but function in the same way as in the first variant. Besides the laterally reversed arrangement of inner sleeve 624 and outer sleeve 626 , a main difference of the second freewheel variant is the separation of right stop 634 from the remainder (left stop 632 and helical groove 630 ) of inner sleeve 624 , and the provision of left stop 632 with a latch bevel 692 , which is engageable with slide member 528 . Right stop 634 has a pin 694 , which engages in a hole 696 . In this manner, stop 634 and the remainder of inner sleeve 624 are indeed non-rotatably connected to each other, but remain axially movable relative to each other. If slide member 528 now moves through freewheel 622 up to right stop 634 in response to activation of the driving mechanism, it moves up the latch bevel 692 . In this process, the slide member presses right stop 634 toward the right against the compression spring and moves beyond the falling portion of latch bevel 692 . In this manner, slide member 528 is fixed in position and locks freewheel 622 . Then, door 2 can only be moved by the driving mechanism, and automatic opening and the acceleration involved are prevented. When outer sleeve 626 is rotated in the opposite direction by the driving mechanism, and freewheel 622 is traversed from the right to the left, freewheel 622 is released from the locked state. [0047] While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. [0000] TABLE 1 Positions of locking pin (558) and sequence of operation Force exerted Total Posi- Appliance Driving by Opening Force exerted Locking Retaining Micro- tion Status Mechanism Freewheel Opening Bar Bar on Lock by Lock Force Pin switch A washing at rest at left stop in rear  0 N −40 N −40 N special 1 position position for micro- switch B start of rotates ″ moves out → 0 N to 20 N −40 N −40 N to −20 N no 0 door counter- function opening clockwise operation C) continued rotates is traversed extends 15 mm 20 N ″ −20 N no 0 opening counter- from left out function clockwise to right D continued rotates at right stop moves out → 20 N to 0 N  −40 N to 15 N  −20 N to 15 N  no 0 opening counter- function clockwise E, end of rotates is traversed extends 90 mm  0 N  0 N  0 N holds 0 E.1 door clockwise from out opening, or opening right to left bar in E.2 operation locked position “Hold/ Door Open” F regular at rest is traversed moves in ← 0 N to 20 N 15 N to −40 N  15 N to −20 N moves 0 opening/ from assisted by to stop closing of left to right spring force position door F0.1 user at rest is traversed moves in ← 0 N to 20 N 15 N to −40 N  15 N to −20 N is pushed 0 presses from assisted by over door left to right spring force the ramp closed G assisted ″ is traversed extends 15 mm 20 N −40 N −20 N holds 0 door- bi- out opening opening directionally bar in force locked position “Hold” H goes to rotates is traversed moves ← 20 N to 0 N  −40 N −20 N to −40 N no 0 washing clockwise from completely in function position right to left Definition of forces: Force vectors having a positive sign in front point out of the washing chamber; force vectors having a negative sign in front point into the washing chamber. LIST OF REFERENCE NUMERALS [0000] 1 dishwasher 10 washing chamber 12 access opening of the washing chamber 14 strengthening channel 16 dishwasher side wall 2 door 20 inner door panel 22 lock catch 24 door magnet 3 door lock (latching mechanism) 30 roller 5 push-open unit 500 lower housing part 502 housing cover 504 push-type opening bar 506 motor 508 motor shaft 510 transmission stages 512 shaft 514 end shield 516 shaft end 518 right angle between the shaft and to the push-type opening bar 520 right angle between the shaft and to the push-type opening bar 522 freewheel 524 inner sleeve 526 outer sleeve 528 slide member 530 helical groove 532 left stop 534 right stop 536 guide grooves for the slide member 538 guide ribs of the slide member 540 extension of the outer sleeve 542 double pinion 544 lateral toothed tracks of the push-type opening bar 546 facial toothing 548 compression spring 550 drive dog 552 torsion spring 554 spring sleeve 556 guide track 558 locking pin 560 anchor member 562 receiving formation for the anchor member 564 arm of the anchor member 566 ferromagnetic metal insert 570 microswitch 572 stop spring 574 front leg 576 rear leg 578 front bearing block 580 rear bearing block 582 stop of the push-type opening bar 584 upper guide slot 586 middle guide slot 588 bevel 590 lower guide slot 622 second freewheel variant 624 inner sleeve 626 outer sleeve 630 helical groove 632 left stop 634 right stop 640 extension 650 hook 692 latch bevel 694 pin of the anti-rotation feature 696 hole of the anti-rotation feature

An automatic warewashing machine includes a washing chamber, a hinged door configured to close the washing chamber, and a force-locking latching mechanism configured to hold the door in a closed position and release the door in response to a pulling force. The force-locking latching mechanism is disposed on the washing chamber or on a body enclosing the washing chamber. A door opening system is also included and has a push-open unit configured to automatically open the door to at least an ajar position. The push-open unit includes a motor-driven push-type opening bar.

BACKGROUND OF THE INVENTION This invention relates to aquarium tanks, and more particularly to a clamping apparatus for connecting an aquarium accessory to the upper edge of an aquarium tank. In using aquarium tanks, it is quite frequent to connect an aquarium accessory to the upper edge of the aquarium tank. By way of example, it is typical to connect a heater at the upper edge of the aquarium tank and have it depend downward into the aquarium tank water to provide controlled heat of the aquarium tank water. Other accessories that are frequently connected to the top of the aquarium tank include valves, such as a gang valve, platforms for holding air pumps, aquarium filters, thermometers, and other aquarium appliances. Occasionally, it may even be desirable to connect aesthetic accessories from the top of the aquarium tank and depend them into the aquarium water. Connecting these aquarium accessories to the aquarium is made difficult by the fact that it is typical to have a rim placed on the upper edge of the aquarium tank. In most cases, aquarium tanks are substantially rectangular in shape. The walls being made of glass or plastic typically have upper edges that may be sharp. To protect the user from harming himself at the sharp upper edge of the aquarium tank, a rim is typically placed over that edge. The rim covers the edge with a substantially inverted U-shaped configuration that saddles the upper edge of the tank walls. However, the rim generally also includes an inwardly directed ledge or lip which projects inwardly towards the center of the aquarium tank. Rims are provided by various manufacturers. While almost all of these are of the same general configuration, the dimensions with respect to the height or depth of the rim varies. Likewise, the dimensions of the ledge or lip vary from rim to rim. The rims not only differ based upon their manufacturing origin but also differ based upon the size of the rim and the size of the aquarium tank on which the rim is to fit. Because of the wide variety of dimensions of the rim on the aquarium tank, it is difficult to design a particular aquarium accessory to universally fit on all aquarium tank rims. In most cases, the coupling arrangement for the aquarium accessory may simply be an inverted U-shaped hook that fits on the upper rim. However, because the width of the rim may vary, the mouth of the hook must be wide enough to accommodate the largest rim. This would then cause difficulties when the accessory is utilized with a narrower rim. The accessory then loosely held, it angles downwardly at an awkward and unaesthetic position, and is easily knocked off the rim. The fact that the accessory can fall into the water by falling off the upper rim may even provide a serious hazard where the accessory is an electrical appliance such as a heater, a pump, or a motor. Other types of clamping arrangements use a screw type coupler. However, again because of the wide variation in rim dimensions, it winds up that on many rims there is inadequate height or thickness dimension for the screw to adequately grasp and provide secure connection to avoid tilting or bending of the aquarium accessory as it depends downward from the rim. Accordingly, there is need for a coupling arrangement for interconnecting accessories to aquarium tanks which can be utilized with all types of aquarium rims and still provide secure, safe, and fixed attachment to the aquarium rim SUMMARY OF THE INVENTION It is accordingly an object of the present invention to provide a clamping arrangement for aquarium accessories which avoids the aforementioned problems of prior art devices. Another object of the present invention is to provide a universal clamp which can be securely connected to the upper rim of an aquarium tank and from which can be connected an aquarium accessory for use with the aquarium tank. Yet another object of the present invention is to provide a coupling arrangement which secures onto the upper rim of an aquarium tank by biting into the rim as the clamp is tightened to the rim. Yet a further object of the present invention is to provide an aquarium accessory which can couple onto the upper rim of the aquarium tank and can be connected regardless of the dimensions of the rim. Briefly, in accordance with the present invention, there is provided an aquarium accessory for removable attachment to the top rim of an aquarium tank. The accessory includes an instrument portion which provides functional or aesthetic use with the aquarium tank. The coupling arrangement for the instrument connects onto the top rim. The coupling arrangement includes a clamping device for securing to the rim. Also included is a portion which bites into the rim upon securement by the clamping device. In an embodiment of the invention, the portion that bites into the rim includes a sharp protrusion which projects substantially perpendicular to the rim and slightly penetrates as the clamping device is tightened onto the rim. In one embodiment of the invention, the accessory can be in the form of an aquarium heater connected to the upper rim of the aquarium tank and depending downwardly into the tank. In another embodiment of the invention, the accessory can be a gang valve which is connected to the rim and fits onto the top of the aquarium tank. Other types of accessories can also be utilized with the accessories serving either a functional or an aesthetic purpose in connection with the aquarium tank. The portion that bites into the rim can be a variety of items including a single sharp projection such as a pin, or an entire broad surface such as a grater surface. The aforementioned objects, features and advantages of the invention, will, in part, be pointed out with particularity, and will, in part, become obvious from the following more detailed description of the invention, taken in conjunction with the accompanying drawings, which forms an integral part thereof. BRIEF DESCRIPTION OF THE DRAWING In the drawing: FIG. 1 is a perspective view showing an aquarium accessory in the form of a heater coupled to the upper rim of an aquarium tank and depending into the aquarium water; FIG. 2 is a schematic view showing the dimensions of a rim typically placed at the upper edge of the aquarium tank; FIG. 3 is a cross-sectional view taken along lines 3--3 of FIG. 1; FIG. 4 is an exploded perspective view of the coupling arrangement in accordance with one embodiment of the present invention; FIG. 5 is an assembled view of the embodiment shown in FIG. 4; FIG. 6 is a perspective view similar to that shown in FIG. 5 and showing another type of a coupling arrangement in accordance with the present invention; FIG. 7 is a perspective exploded view of a gang valve accessory for connection to the upper rim of an aquarium tank and showing another type of coupling arrangement in accordance with the present invention; FIG. 8 is an assembled perspective view of the device shown in FIG. 7, and FIG. 9 is a cross-sectional view of the aquarium tank showing the gang valve of FIGS. 7 and 8 positioned on the aquarium tank. In the various figures of the drawing like reference characters designate like parts. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown an aquarium tank 10 of substantially rectangular configuration including side walls 12 and containing water 14. At the upper edge of the walls is provided a safety protection rim 16 which sits on the upper edge of the walls of the aquarium tank. Typically, various types of aquarium accessories will be connected at the top of the aquarium tank. Some of these will depend into the aquarium water while others will sit on top of the tank and yet others may be connected to the upper edge of the aquarium tank and hang outside of the aquarium tank. By way of example, one such an aquarium accessory is shown as the heater 18 which is connected to the top of the tank. Although various types of heater devices are well known, the heater as shown includes an upper head portion 20 having a covering ring from which depends a heater element 22. Any such type of heater as is well known in the art can be utilized. The problem of connecting the aquarium accessory, such as the heater 18, can best be understood by viewing a cross section of the upper rim 16 of the aquarium tank as is shown in FIG. 2. The typical aquarium rim is of substantially inverted U-shape configuration including a first longer leg 24 which is positioned typically on the outside of the aquarium tank. A second shorter leg 26 is positioned on the inside of the aquarium tank. These two legs are interconnected by a bridge wall 28 which sits at the top of the edge of the aquarium tank. Typically, an inwardly turned lip or ledge 30 terminates the shorter wall 26. The various sections of the rim have different dimensions based upon the type of manufacturer as well as the size of the aquarium tank on which it is being utilized. The various dimensions are shown indicated by letters. A study of substantially all of the available rims indicate the following variational dimensions of these given sections. Specifically, the bridge wall 28 is identified by the dimension A and it has been found that such dimension varies for a typical rectangular aquarium tank between 0.261" and 0.815". For non-rectangular aquarium tanks, such dimensions have been found to vary between 0.319" and 0.712". The extent of the ledge 30 is given by the dimension B and for rectangular aquarium tanks has been found to vary between 0.120" until 0.395". For non-rectangular aquarium tanks such dimension has been found to vary between 0.161" and 0.340". The height of the wall 26 above the ledge 30 is designated by C and for rectangular aquarium tanks, such dimension has been found to vary between 0.128" and 0.790". For non-rectangular aquarium tanks the variation has been found to be a low of 0.188" and a high of 0.650". The thickness of the ledge 30 is shown by the dimension D and for rectangular aquarium tanks such thickness has been found on rims to be between a dimension of 0.060" and 0.160". For non-rectangular aquarium tanks, the variation has been found between 0.069" and 0.127". The height of the outer wall 24 is given by the dimension E. The smallest height found for rectangular aquarium tanks has been found to be 0.500" and the largest has been found to be 2.010". For non-rectangular tanks the variation has been between 0.765" and 1.617". It is accordingly seen that the rims vary greatly in their size. Any coupling device which simply overhangs the top of the rim may not have enough clearance for the variations in the length of the ledge 30, which varies considerably from rim to rim. If enough clearance is provided for the largest ledge, then for thin ledges the accessory will bend inwardly at an angle. If the overhang is provided just enough for the shortest legs, then it will bend outwardly trying to over reach the wider ledge. Should a sample clamping arrangement be utilized, then since the dimension C is very shallow on some rims, there would be insufficient room to grab such shallow portion and the appliance would fall off the rim. When falling off the rim, it may fall into the aquarium water causing a hazard, especially where electrical appliances are utilized. Likewise, the variation in the dimension A causes difficulty in providing sufficient clearance for both thin as well as wide rims. As can best be seen in FIGS. 1 and 3, in the present invention, there is provided a coupling device, shown generally at 32 which serves to hold the particular type of accessory, in this case the heater 18. The coupling device 32 is shown to be a substantially U-shaped configuration having an outer wall 34, an inner wall 36, and interconnected by a top or bridge wall 38. An aperture 40 provided in the outer wall 34 is threaded and through which extends a clamping screw 42. A knurled head 44 at the outer end of the clamping screw facilitates threading of the screw. Likewise, a pointed stud 46 at the inner end provides a secure clamping onto the outer wall 24 of the rim 16. In order to secure the clamp in place, there is provided a biting member 50. As can best be seen in FIGS. 3, 4 and 5, the biting member 50 includes a flat surface 52 from which projects a-plurality of sharp projections 54 simulating a grating surface. The biting member 50 is held in place by providing a channeled lower edge 56 which seats around the bottom of the wall 36. A flange extension 58 from the top end of the surface 52 includes a plurality of spring fingers 60 defining central aperture 62. A stud 64 downwardly depending from the bridge wall 38 of the coupling device 32 is seated into the aperture 62 and the spring fingers 60 grasp onto the stud 64 preventing downward pulling of he biting member 50. The assembled biting member 50 positioned in place is shown in FIG. 5. As can best be seen in FIG. 3, the clamp is connected so that the biting portion, and specifically the protrusions 54 are placed on the inner wall 26 of the rim. The clamping screw 42 is threaded onto the outer wall 24 of the rim. As the clamping screw is tightened, the protrusions bite further into the rim thereby securing the clamp in place. It should be appreciated, that even if the ledge 30 were to vary in dimension, the clamp would still be retained regardless of the length B of the ledge. Likewise, the height of the wall 24 shown by the dimension E does not come into play since the clamp will clamp at the upper edge regardless of how much the wall depends therefrom. Likewise, so long as the top wall 38 of the clamp is made sufficiently wide to accommodate the widest dimension A, it will automatically serve any smaller dimensions. Concerning the dimension C, the only requirement is that the sharp projections 54 are present at the bottom of the surface wall 52 to penetrate into whatever height C is provided. In that way, regardless of what the dimension C is, it will bite into a portion of the rim and hold the clamp in place. It is thus noted, that the clamping device will always manage to secure the accessory in place regardless of the rim dimension. Furthermore, with an accessory of the type shown in FIG. 1 which depends downwardly, the accessory will always be held away from the ledge 30 and will depend substantially vertically downward into the water without being angularly bent. As shown in FIG. 6, the biting projection need not be a grating surface. Specifically, in FIG. 6 there is shown a aquarium accessory holder 70 of the type shown in FIGS. 4 and 5. In this case, however, the biting portion is shown by a single pin 72 projecting from the clamping screw 74. Additionally, there is shown a second pin 76 projecting from the inner wall 78 of the inverted U-shaped arrangement of the clamp portion 80. While two pins 72, 76 are both shown, it should be appreciated that only one of these is necessary. Specifically, the pin 76 can be used alone and the clamping screw 74 utilized without its pin 72. Likewise, the pin 72 can be used at the end of the clamping screw without any pin 76 used on the inside wall. Where both pins are utilized, the pins are preferably coaxial with each other. Likewise, the pins are positioned such that they are preferably perpendicular to the rim. However, they can also be at oblique angles so long as they are able to bite into or penetrate into the wall of the rim. It should be appreciated, that in a similar manner in FIGS. 4 and 5, the clamping screw should preferably be coaxial with the grating surface or a least with some of the sharp projections on the grating surface. This will provide a good arrangement whereby the clamp will exert a force coaxially with the presence of the sharp projections thereby assuring that the projections will bite into the rim. Although the accessory shown in FIGS. 1-6 is of a depending heater, it should be appreciated that other types of aquarium accessories could likewise be secured in place by means of the same type of clamping arrangement. Specifically, referring to FIGS. 7, 8 and 9, there is shown a gang valve 90 having an instrument portion 92 sitting on top of the clamping portion 94. The clamping portion 94 again includes a substantially inverted U-shaped arrangement having opposing walls 96 on the outside and 98 on the inside interconnected by a bridge or top wall 100. The clamping screw 102 passes through a threaded aperture 104 in the outer wall 96 and is terminated by means of an enlarged head 106 on the outside and the stud 108 at the inner edge of the screw. Positioned on the inside of the inner wall 98 is a biting member 110. The biting member includes a grating surface 112 which contains a plurality of individual sharp projections 114. The biting member 110 is secured in place by means of a pair of laterally directed wings 116, 118 on which are included upwardly bent tab portions 120. A pair of opposing channels 122, 124 terminating in an undercut slice 126 is provided in the wall 98. The biting member 110 can then be forced fitted into place with the wings sliding into the slit 126 and the tabs 120 locking the grating surface in place by means of a friction type engagement. In connecting an accessory secured to the coupling means, the coupling means is placed over the rim 130. The clamping screw is tightened on to the outer wall 132 of the rim and the grating surface bites into the inner rim wall 134 to secure the coupling means in place. The particular accessory shown is a gang valve having an inlet 140 and two outlets 142, 144. The outlets are controlled by means of the valves having knobs 146, 148. A tubing, 150 shown in dotted lines, would be connected to at least one if not both of the outlets. A removable cap member 152 is connected across another outlet 154 to further connect an additional gang valve in tandem with the first gang valve 90 shown. Air enters the inlet 140 and passes through a plenum chamber 160. From the plenum 160 the air can pass through any of the various outlets depending upon which are uncovered and which are opened by means of the valve controls. It should be appreciated, that in addition to the particular type of accessory shown, other types of aquarium accessories could be secured in place by means of the same type of clamping arrangement. Likewise, other types of biting means could be utilized to penetrate or bite into the aquarium rim. The particular pins that have been shown, need not extend very far out of the device. In fact, a pin of the size of only one thousandth of an inch would be sufficient to provide adequate penetration and biting. Likewise, the individual projections need not be more than one thousandth of an inch above the grating surface. As long as there is some projection into the rim, it would be sufficient. Typically, the rims are formed of plastic or rubber material and even minimal projections would be sufficient to bite in and grasp the rim to secure the clamp in place. There has been disclosed heretofore the best embodiment of the invention presently contemplated. However, it is to be understood that various changes and modifications may be made thereto without departing from the spirit of the invention.

An aquarium accessory for removable attachment to the top rim of an aquarium tank. The accessory includes an instrument useful for the functional or aesthetic benefit of the aquarium tank. A coupling arrangement is connected to the instrument. The coupling arrangement includes a clamping screw for securing to the rim. Coaxillay arranged with the claimping screw is a biting device positioned on the coupling means for biting into the rim upon securement by the clamping screw.

REFERENCE TO PENDING APPLICATIONS [0001] This application is a continuation-in-part application claiming priority to U.S. patent application Ser. No. 11/731,538 filed Mar. 30, 2007, entitled Ventilator to Tracheotomy Tube Coupling which is a continuation-in-part application claiming priority to U.S. patent application Ser. No. 11/348,199, filed Feb. 6, 2006, entitled Ventilator to Tracheotomy Tube Coupling. REFERENCE TO MICROFICHE APPENDIX [0002] This application is not referenced in any microfiche appendix. BACKGROUND OF THE INVENTION [0003] This invention relates generally to medical equipment and more particularly concerns devices used to connect ventilators to tracheotomy tubes. [0004] For adult patients, two-piece tracheotomy tubes having inner and outer cannulas are presently in common use. The outer cannula is inserted into the patient's windpipe and the inner cannula is inserted into or removed from the outer cannula for use or for replacement, cleaning or disinfecting, respectively. The outer cannula of these two-piece devices has a collar on its trailing end which is configured to be positively engaged with a collar on the leading end of the inner cannula. The cannulas cannot be disengaged from each other affirmative release of their positive engagement. The trailing end of the combined cannulas has a tapered tubular extension which plugs into or into which is plugged, depending on the diameter of the tubular extension of the particular tracheotomy tube, the leading end of a flexible connector. The trailing end of the flexible connector is connected to a tube extending from the ventilator or other external equipment. The present tapered tubular extension connection to the ventilator is dependent on mere insertion of a tapered tube into a constant diameter tube in the hope of achieving a snug fit. To assist in making this connection, the flexible connectors have annular flanges with significantly wider diameters than the tubular portions of the connectors so as to facilitate manipulation of the connectors with the thumb and forefinger. [0005] For children, a smaller, one piece tracheotomy tube is made from a very soft, pliant material. The entire tracheotomy tube must be frequently removed, at least once a week, from the child's trachea, cleaned and disinfected and reinserted into the trachea. The same flanged flexible connector used with the adult devices is also used with the children's devices. The tapered tubular extension of the children's tracheotomy tube is integral with the pliant tracheotomy tube and has a hard plastic outer sleeve which is inserted directly into the flexible connector. An annular flange on the trailing end of the tubular extension of the child's tracheotomy tube holds the hard plastic sleeve in place on the extension. [0006] Because of their structural configuration and operational steps, there are some problems inherent in the known one or two piece tracheotomy tubes, in the known flexible connectors and in their combination. [0007] One set of problems is related to the comfort of the patient. The profile of the flanged flexible connectors, falling generally between the underside of the patient's chin and the patient's chest, fosters a breakdown of skin and tissue on the chin or chest, depending on the head movements of the patient. This is especially true for children, their chin-to-chest cavity being comparatively small. This concern is sometimes addressed by after-market removal of all or a portion of the flange, but this solution generally results in a damaged connector, increasing the likelihood of infection-causing secretions and also becomes less secure due to removal of the firm portion of the connector. Also, the manipulation of the flange to connect or disconnect the connector to or from the tubular extension can cause considerable discomfort to the patient, since this often requires the application of manual pressure to the patient's neck, chin or chest. It is common practice to extend rubber bands from one side of a neck plate on the tracheotomy tube collar to the flexible connector and back to the other side of the neck plate in an effort to hold the flexible connector in place, but the rubber bands are likely either too elastic or too inelastic to properly accomplish this purpose. While a child's tracheotomy tube is smaller than an adult's, the available space between the chin and chest is significantly smaller and the flexible connector flange is the same size as used for adults, so the smaller device affords no relief for the connector flange related comfort problems. And, since the child's tracheotomy tubes are of one piece construction, the force necessary to disconnect the flexible connector may be directly applied to the patient's neck or windpipe. [0008] A second set of problems is related directly to the ability, or inability, of the system to accomplish its primary purpose of keeping the patient's trachea connected to the ventilator. To begin with, tapered connections tend to easily separate in the best of circumstances, there being minimal surface contact between the tapered and constant diameter components. Moreover, the connector and tracheotomy tube parts are always wet and slippery due to the very nature of their application and are not very tightly mated because of the neck pressure problems. The end result is a connection so tenuous that a mere sneeze, cough or turn or tip of the head can cause the connector and the tapered tubular extension to separate, defeating the operation of the system. Even without a sneeze, cough, turn or tip, the flange itself functions as a lever against the chin or chest in response to the patient's head movements, and the reciprocal levering by the flange will eventually cause the connector and the tubular extension to disconnect. [0009] A third set of problems concerns the performance of the medical staff as a result of these other problems. The inherent comfort issues result in more pains-taking, time-consuming effort by the staff in an effort to reduce the impact of these discomforts on the patient. And, because of the ease of inadvertent disconnection of the system, the staff unnecessarily spends valuable time monitoring and reconnecting the connectors to the tubular extensions of the tracheotomy tubes. [0010] It is, therefore, a primary object of this invention to provide an improved tracheotomy tube coupling. Another object of this invention is to provide a tracheotomy tube coupling which reduces a likelihood of associated patient discomfort. It is also an object of this invention to provide a tracheotomy tube coupling which is more suitably profiled for positioning between a patient's chin and chest. Still another object of this invention is to provide a tracheotomy tube coupling which is profiled to reduce a likelihood of skin or tissue breakdown on a patient's chin and chest. A further object of this invention is to provide a tracheotomy tube coupling which simplifies manipulation of the coupling in relation to the patient. Yet another object of this invention to provide a tracheotomy tube coupling which reduces a likelihood of exertion of discomforting pressure on the chin, neck, chest or windpipe of a patient during connection or disconnection of the coupling from the tracheotomy tube. An additional object of this invention is to provide a tracheotomy tube coupling which makes inadvertent disconnection of the tracheotomy tube from the connected medical equipment less likely. Another object of this invention is to provide a tracheotomy tube coupling which does not rely on tapered to constant diameter connections to maintain connection between the tracheotomy tube and its related equipment. It is also an object of this invention to provide a tracheotomy tube coupling which is profiled to reduce a likelihood that the coupling will operate as a self-disconnecting lever. Still another object of this invention to provide a tracheotomy tube coupling which can be easily connected and disconnected from the tracheotomy tube by the medical staff. A further object of this invention is to provide a tracheotomy tube coupling which can reduce the time expended by the medical staff to monitor and maintain the coupling connections. Yet another object of this invention is to provide a tracheotomy tube coupling which facilitates more rapid disassembly and reassembly of associated components from the tracheotomy tube for cleaning and disinfecting purposes. SUMMARY OF THE INVENTION [0011] In accordance with the invention, a coupling is provided for connecting a ventilator tube to a tracheotomy tube. The ventilator tube has a connector at its leading end and the tracheotomy tube has a tapered tubular extension on its trailing end. The coupling is a preferably expandable, flexible tubular member with a first adapter on its trailing end for connecting its trailing end in a pneumatic flow path to the ventilator tube leading end connector and a second adapter on its leading end for mating its leading end in a pneumatic flow path with the trailing end of the tracheotomy tube. The second adapter has a latching mechanism for engaging the leading end of the coupling to the tracheotomy tube to prevent the leading end of the tubular member from axially displacing from the trailing end of the tracheotomy tube after they have been mated in the pneumatic flow path. An unlatching mechanism is provided for disengaging the latching mechanism from the tracheotomy tube so as to permit the leading end of the tubular member to axially displace from the trailing end of the tracheotomy tube. The unlatching mechanism is operated by non-axial forces so that the coupling can be disengaged from the tracheotomy tube without exertion of excessive axial force on the patient's neck. [0012] Some known adult tracheotomy tubes have an inner cannula inserted into a trailing end of an outer cannula with the tubular extension on the trailing end of the inner cannula. For such tracheotomy tubes, the coupling tubular member has a first means on its leading end for mating the tubular member in the pneumatic flow path with the tubular extension of the inner cannula which is operable by motion of the mating means in a generally axial direction relative to the tubular extension. A second means is provided on the mating means for engaging with the outer cannula during mating to prevent the leading end of the tubular member from axially displacing from the tubular extension after mating. A third means is provided on the inner cannula for disengaging the engaging means from the outer cannula by application of force to the mating means in other than the generally axial direction to permit the leading end of the tubular member to axially displace from the tubular extension of the inner cannula. Typically, the trailing end of the outer cannula has opposed annular flanges and the engaging means consists of opposed means for resiliently snapping over the flanges. The disengaging means consists of means on the inner cannula for spreading the opposed flanges during rotational motion of the mating means about a longitudinal axis of the tubular member. [0013] Other known adult tracheotomy tubes have an inner cannula inserted into a trailing end of an outer cannula with the tubular extension on the trailing end of the inner cannula. For such tracheotomy tubes, the coupling tubular member has a first means on a leading end of the tubular member for mating the tubular member in the pneumatic flow path with the tubular extension of the outer cannula by motion of the mating means in a generally axial direction relative to the tubular extension. A second means is provided on the mating means for engaging with the outer cannula during mating to prevent the tubular member from axially displacing from the tubular extension after mating. A third means is provided on the outer cannula which is operable by application of force on the mating means in a direction other than the generally axial direction for disengaging the engaging means from the outer cannula to permit the tubular member to axially displace from the tubular extension of the outer cannula. Typically, the trailing end of the outer cannula has annularly opposed flat notches. The disengaging means consists of means on the outer cannula for spreading the opposed flanges during rotational motion of the mating means about a longitudinal axis of the tubular member. [0014] Known child tracheotomy tubes have a tubular extension on their trailing end. For such tracheotomy tubes, the coupling tubular member has a first means for mating the leading end of the tubular member in the pneumatic flow path with the tubular extension of the tracheotomy tube by motion of the mating means in a generally axial direction relative to the tubular extension. A second means is provided on the mating means for engaging with the tracheotomy tube to prevent the leading end of the tubular member from axially displacing from the tubular extension after mating. A third means is provided on the mating means which is operable by application of force on the mating means in other than the generally axial direction for disengaging the engaging means from the tracheotomy tube to permit the tubular member to axially displace from the tubular extension of the tracheotomy tube. The mating means consists of a nozzle insertable into the tubular extension. The engaging means consists of a clamshell, the clamshell and the tubular extension having complementary three-dimensional surfaces which prevent axial displacement of the clamshell from the tubular extension gripped therein. Half of the clamshell has diametrically opposite lugs and another half of the clamshell has diametrically opposite fingers which resiliently snap over the lugs when the clamshell is closed. The disengaging means consists of means on the fingers for spreading the fingers in response to inward radial pressure on the spreading means to release the lugs. [0015] An improved child's tracheotomy tube has an arcuate soft tube cannula with a neck plate on its trailing end. The neck plate has a passageway aligned with the cannula passageway and an annular ring on its trailing side which extends the passageway. A tubular extension trails from the annular ring to further extend the passageway. Preferably, the tubular extension is formed using a soft inner tube and a hard outer sleeve permanently fused to the soft inner tube. The annular ring has at least one, and preferably three, circumferential sets of at least two displaced serrations in its outer wall. Preferably, the serrations are equally displaced on the circumference, for example two diametrically opposed serrations, with corresponding serrations of each circumferential set being aligned on parallel diameters of the annular ring with the diameters being horizontal in relation to a vertical plane bisecting the arcuate cannula. [0016] To connect the improved child's tracheotomy tube to a ventilator tube, the coupling provided has a tubular member adapted at its trailing end for connection in a pneumatic flow path to the ventilator tube leading end connector. The leading end of tubular member is adapted for mating the tubular member in the pneumatic flow path with the tubular extension of the tracheotomy tube by motion of the mating means in a generally axial direction relative to the tubular extension. The leading end of the tubular member is further adapted for engaging with one of the circumferential sets of serrations to prevent the leading end of the tubular member from axially displacing from the tubular extension after mating. The leading end of the tubular member is further adapted to be operable by application of force in other than the generally axial direction for disengaging the leading end of the tubular member from the engaged circumferential set of serrations to permit the leading end of the tubular member to be axially displaced from the tubular extension of the tracheotomy tube. Preferably, the trailing end adaptation of the tubular member is a hard annular ring on its trailing end, the ring having a tubular concentric rearward extension, a sleeve mounted for rotation on the extension and a stop mechanism on the extension for preventing the sleeve from axially displacing from the extension. This sleeve-on-extension configuration of the of the coupling allows rotational forces exerted on the tracheotomy system to be more likely dissipated at the ventilator end rather than the tracheotomy tube end of the system. Preferably, the leading end mating adaptation is a hard sleeve of inner diameter sized to axially receive the tracheotomy tube tubular extension with the trailing face of the tracheotomy tube extension abutting the trailing interior annular wall of the sleeve. Thus, axial motion is required only for initiation of abutting contact, reducing the likelihood of exertion of such axial force as might be required to create a frictionally tight locking fit. Preferably, the leading end engaging adaptation is a circumferential set of at least two fingers resiliently mounted on and oriented forward of the sleeve for seating in one of the circumferential sets of displaced serrations on the tracheotomy tube annular ring when the trailing face of the tracheotomy tube tubular extension abuts the trailing interior annular wall of the sleeve. Thus, the force exerted to engage the components is primarily radial rather than axial or rotational, reducing the likelihood of exertion of excessive axial force on the system. It is also preferred that disengaging adaptation be squeeze plates on the fingers for radially displacing the fingers to release them from the engaged set of serrations in response to radially inward pressure on the squeeze plates. Thus, the force exerted to disengage the components is also primarily radial rather than axial or rotational, reducing the likelihood of exertion of excessive axial force on the system. [0017] A different embodiment of the coupling could be used to connect an air supply to any of a variety of respiratory support devices which are provided with radially outwardly extending flanges proximate their trailing end. The coupling would include the longitudinally flexing tubular member with a first adapter on its trailing end for connecting its trailing end in a pneumatic flow path to the air supply and a second adapter on its leading end for mating its leading end in the pneumatic flow path with the respiratory support device by motion of the second adapter in a generally axial direction toward the respiratory support device bringing a leading face of the flexing tubular member into abutment with a trailing face of a trailing end of the respiratory support device. A mechanism on the second adapter engages with the flanges of the respiratory support device when the flexing tubular member and the trailing face of the respiratory support device are in abutment, thus preventing the flexing tubular member from axially displacing from the respiratory support device. The engaging mechanism includes a mechanism co-operable with the respiratory support device flanges to disengage the engaging mechanism from the respiratory support device flanges by rotational movement of the second adapter relative to the respiratory support device, permitting the flexing tubular member to axially displace from the respiratory support device. Preferably, if an outer longitudinal wall of the respiratory support device is tapered, an inner longitudinal wall of the second adapter will be tapered so as to come into abutment with the tapered wall of the respiratory support device during mating of the coupling with the respiratory support device. Such a respiratory support device could, for example, be a tracheotomy tube outer cannula with radially outwardly extending flanges proximate its trailing end. In this application, the coupling would further include an inner cannula with a tubular extension on its trailing end with fingers resiliently pivoted on the perimeter of the tubular extension which will snap over the outer cannula flanges when a leading face of said tubular extension comes into abutment with a trailing face of the outer cannula. A pair of radially outwardly extending flanges angularly oriented between and trailing behind the fingers would be co-operable with the engaging mechanism of the second adapter of the coupling. The fingers prevent axial displacement of the inner cannula from the outer cannula and the engaging mechanism prevents the coupling from axially displacing from the inner cannula. The engaging mechanism includes a mechanism co-operable with the inner cannula flanges to disengage the engaging mechanism from the inner cannula flanges by rotational movement of the second adapter relative to the inner cannula tubular extension so as to permit the flexing tubular member to axially displace from the inner cannula tubular extension. The outer longitudinal wall of the inner cannula tubular extension and the inner longitudinal wall of the second adapter are preferably tapered so that they come into abutment during mating of the coupling with the inner cannula. BRIEF DESCRIPTION OF THE DRAWINGS [0018] Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which: [0019] FIG. 1 is a perspective view of a first type of known tracheotomy tube outer cannula; [0020] FIG. 2 is a perspective view of a first embodiment of an inner cannula for use with the outer cannula of FIG. 1 ; [0021] FIG. 3 is a perspective view of a first embodiment of a coupling connected to the inner cannula of FIG. 2 ; [0022] FIG. 4 is a side elevation assembly view of the coupling and cannulas of FIGS. 1-3 ; [0023] FIG. 5 is a top plan assembly view from the line 5 - 5 of FIG. 4 ; [0024] FIG. 6 is a side elevation view of the assembled coupling and cannulas of FIGS. 1-3 ; [0025] FIG. 7 is a perspective assembly view of the leading end adapter of the coupling of FIG. 3 and the outer cannula of FIG. 1 ; [0026] FIG. 8 is a side elevation view of the assembled leading end adapter of the coupling of FIG. 3 and inner cannula of FIG. 2 ; [0027] FIG. 9 is a trailing end elevation view of the assembly of FIG. 8 ; [0028] FIG. 10 is a top plan view of the assembly of FIG. 8 ; [0029] FIG. 11 is a leading end elevation view of the assembly of FIG. 8 ; [0030] FIG. 12 is a leading end perspective view of the leading end adapter of the coupling of FIG. 3 ; [0031] FIG. 13 is a trailing end perspective view of the leading end adapter of the coupling of FIG. 3 ; [0032] FIG. 14 is a side elevation view of the leading end adapter of the coupling of FIG. 3 ; [0033] FIG. 15 is a trailing end elevation view of the trailing end adapter of the coupling of FIG. 3 ; [0034] FIG. 16 is a top plan view of the leading end adapter of the coupling of FIG. 1 ; [0035] FIG. 17 is a leading end perspective view of the inner cannula of FIG. 2 and leading end adapter of the coupling of FIG. 3 in an operatively assembled condition; [0036] FIG. 18 is a leading end perspective view of the inner cannula of FIG. 2 and leading end adapter of the coupling of FIG. 3 in a ready-to-disconnect condition; [0037] FIG. 19 is a perspective assembly view of a second embodiment of the coupling and inner cannula in relationship to a second type of known tracheotomy tube outer cannula; [0038] FIG. 20 is a top plan assembly view of the coupling and cannulas of FIG. 19 ; [0039] FIG. 21 is a trailing end view of the leading end of the coupling of FIG. 19 ; [0040] FIG. 22 is a leading end view of the leading end of the coupling of FIG. 19 ; [0041] FIG. 23 is a side elevation view of the leading end of the coupling of FIG. 19 ; [0042] FIG. 24 is a top plan view of the leading end of the coupling of FIG. 19 ; [0043] FIG. 25 is a side elevation assembly view of the cannulas and coupling of FIG. 19 ; [0044] FIG. 26 is a side elevation view of the assembled cannulas and coupling of FIG. 19 ; [0045] FIG. 27 is a perspective assembly view of a third embodiment of the coupling in relationship to a third type of known tracheotomy tube; [0046] FIG. 28 is a top plan assembly view of the coupling and tracheotomy tube of FIG. 27 ; [0047] FIG. 29 is a leading end perspective view of the coupling of FIG. 27 in an open condition; [0048] FIG. 30 is a leading end elevation view of the coupling of FIG. 27 in the open condition; [0049] FIG. 31 is a top plan view of the leading end of the coupling of FIG. 27 in the open condition; [0050] FIG. 32 is a side elevation view of the leading end of the coupling of FIG. 27 in the open condition; [0051] FIG. 33 is a side elevation assembly view of the coupling and tracheotomy tube of FIG. 27 ; [0052] FIG. 34 is a side elevation view of the coupling and tracheotomy tube of FIG. 27 with the leading end of the coupling in the open condition; [0053] FIG. 35 is a side elevation view of the assembled coupling and tracheotomy tube of FIG. 27 ; [0054] FIG. 36 is a perspective assembly view of an improved child's tracheotomy tube and associated coupling; [0055] FIG. 37 is a perspective assembly view of a fourth embodiment of the coupling and an associated tracheotomy tube inner cannula; [0056] FIG. 38 is a perspective assembly view of the assembled coupling and inner cannula of FIG. 37 in association with a corresponding known tracheotomy tube outer cannula; [0057] FIG. 39 is a side elevation assembly view of the coupling of FIG. 37 and the assembled inner and outer cannulae of FIGS. 37 and 38 ; [0058] FIG. 40 is a top plane assembly view of the coupling and inner cannula of FIG. 37 ; [0059] FIG. 41 is a side elevation view of the assembled coupling and inner and outer cannula of FIGS. 37 and 38 ; [0060] FIG. 42 is a top plane view of the assembled coupling and inner and outer cannulae of FIGS. 37 and 38 ; [0061] FIG. 43 is a cross-sectional view taken along the line 43 - 43 of FIG. 39 ; [0062] FIG. 44 is a cross-sectional view taken along the line 44 - 44 of FIG. 39 ; and [0063] FIG. 45 is a cross-sectional view taken along the line 45 - 45 of FIG. 37 . [0064] While the invention will be described in connection with preferred embodiments thereof, it will be understood that it is not intended to limit the invention to those embodiments or to the details of the construction or arrangement of parts illustrated in the accompanying drawings. DETAILED DESCRIPTION Tracheal Inserts [0065] Adult tracheotomy tubes are illustrated in FIGS. 1-18 , showing a tracheotomy tube with outer and inner cannulas 100 and 130 and a tapered tubular extension 139 on the trailing end of the inner cannula 130 and FIGS. 19-26 , showing a tracheotomy tube with outer and inner cannulas 200 and 230 and a tapered tubular extension 223 on the trailing end of the outer cannula 200 . A child's tracheotomy tube is illustrated in FIGS. 27-35 . A child's tracheotomy tube has only one cannula which, for purposes of explanation of the invention is identified as an outer cannula 300 . [0066] All three known outer cannulas 100 , 200 and 300 are, in some respects, substantially similar, being arced tubes 101 , 201 or 301 of approximately a quarter circle extending from a leading end 103 , 203 or 303 to a collar 105 , 205 or 305 at the trailing end 107 , 207 or 307 of the arced tube 101 , 201 or 301 . A cuff 109 , 209 or 309 on the leading half of the arced tube 101 , 201 or 301 is inflatable via an air supply line 111 , 211 or 311 . The arced tube 101 , 201 or 301 is the tracheal insert portion of the tracheotomy tube and, once inserted, the cuff 109 , 209 or 309 is inflated to hold and seal the tube 101 , 201 or 301 in position in the trachea. Each of the outer cannulas 100 , 200 or 300 has a neck plate 115 , 215 or 315 which positions the outer cannulas 100 , 200 or 300 against the patient's neck and is adapted to maximize its manipulability relative to the collar 105 , 205 or 305 by connecting hinges 117 or by openings 217 or contours 317 in its body. Each of the neck plates 115 , 215 or 315 also has openings 119 , 219 or 319 for connection of an adjustable strap to pass around and secure the neck plates 115 , 215 or 315 against the patient's neck. The adult outer cannulas 100 and 200 are comparatively hard and the child's outer cannula 300 is very soft. From the collars 105 , 205 and 305 on the trailing ends of the arced tubes 101 , 201 and 301 toward the trailing ends of the outer cannulas 100 , 200 and 300 , the configurations of the outer cannulas 100 , 200 and 300 are quite different. [0067] Both inner cannulas 130 and 230 are also, in some respects, substantially similar, being arced tubes 131 or 231 of approximately a quarter circle extending from a leading end 133 or 233 to a collar 135 or 235 on a trailing end 137 or 237 of the arced tube 131 or 231 . The inner cannulas 130 and 230 are inserted at their leading ends 131 and 231 into the trailing ends of their outer cannulas 100 and 200 until their trailing ends mate. From the collars 135 and 235 toward the trailing ends of the inner cannulas 130 and 230 , the inner cannulas 130 and 230 are quite different. [0068] The outer cannulas 100 , 200 and 300 and their associated known inner cannulas have mechanisms which positively engage them against separation in their mated condition. They all present tapered tubular extensions for connection with known flexible connectors. The connection to known flexible connectors is universally accomplished by mere insertion of a tapered end of a tube into a constant diameter tube. The following illustrated embodiments of the outer cannulas 100 , 200 and 300 are substantially the same as the known outer cannulas. The illustrated embodiments of the inner cannulas 130 and 230 and the flexible connectors or couplings 160 , 260 and 360 are substantially different from the known inner cannulas and connectors so as to permit a positive engagement of the outer cannulas with their flexible connectors. However, they have been configured to work with the known outer cannulas 100 , 200 and 300 . The principles of the invention, however, are fully applicable to the connection of flexible connectors to outer cannulas other than those herein illustrated. First Adult Tracheotomy Tube Embodiment [0069] Looking now at FIGS. 1-18 , the first type of adult tracheotomy tube is illustrated. As best seen in FIG. 1 , the collar 105 on the outer cannula 100 has an annular ring 121 which is concentric about the trailing end 107 of the outer cannula tube 101 and has top and bottom quarter arcs 123 which extend concentrically on and in a trailing direction from the ring 121 . A concentric groove 125 is also provided in the face of the trailing end 107 of the outer cannula tube 101 . [0070] Looking at FIGS. 1-3 and 8 - 11 , the inner cannula 130 applies the principles of the invention to the outer cannula 100 . A soft arced tube 131 extends upwardly and rearwardly from its leading end 133 to a hard collar 135 on its trailing end 137 . The collar 135 tapers outwardly to a wider, concentric, hard, tapered tubular extension 139 which extends in a trailing direction from the collar 135 . The extension 139 tapers toward its trailing end face 141 . The collar 135 has a pair of diametrically opposed latches 143 , as shown appearing at approximately the 2 and 8 o'clock orientations when looking at the trailing end face 141 of the inner cannula 130 . The latches 143 have fingers 145 which extend radially inwardly therefrom for engagement against the trailing face of the annular ring 121 on the trailing end 103 of the outer cannula 100 . The fingers 145 extend in the leading end direction from resiliently flexible supports 147 on the collar 135 . Squeeze plates 149 extend in the trailing end direction from the fingers 145 . The leading faces 151 of the fingers 145 are beveled so that, as the inner cannula 130 is inserted into the outer cannula 100 and the beveled faces contact the annular ring 121 , the supports 147 flex to widen the distance between the fingers 145 . Once the fingers 145 pass over the annular ring 121 , the supports return to their unbiased condition in which the trailing faces of the fingers 145 engage the leading face of the ring 121 , thus locking the inner cannula 130 in place on the outer cannula 100 . The squeeze plates 149 provide suitable surfaces and leverage for the thumb and forefinger to apply pressure to flex the support 147 and spread the fingers 145 so that the fingers 145 can be disengaged from the annular ring 121 . The squeeze plates 149 have alignment indicia such as arrows 153 , as shown diametrically opposed and pointing in the trailing end direction. As best seen in FIGS. 6, 8 , 9 , 11 , 17 and 18 , the collar 135 also has diametrically opposed rotational and longitudinal ramps 155 and 157 and longitudinal beads 159 for reasons hereinafter explained. [0071] Looking at FIGS. 1-16 , the flexible connector 160 for use with the above outer and inner cannulas 100 and 130 has a leading end adapter 161 , best seen in FIGS. 5, 7 and 12 - 15 . The leading end adapter 161 has a hard outer sleeve 167 with a soft tube liner 169 . The trailing end 171 of the sleeve 167 is of narrower diameter so as to provide a connecting ring 173 for reasons hereinafter explained. The outer sleeve 167 has diametrically opposed posts 175 on its wide circumference at the leading end of the connecting ring 173 . A pair of diametrically opposed resiliently flexible arms 177 extend longitudinally from the sleeve 167 to radially inwardly extending fingers 179 . The sleeve 167 also has alignment indicia such as arrows 181 pointing in the leading end direction. The flexible connector 160 is in proper rotational orientation for connection to the outer and inner cannulas 100 and 130 when the arrows 153 on the inner cannula 130 are aligned with the arrows 181 on the connector sleeve 167 . As best seen in FIG. 6 , when the arrows 153 and 181 are aligned, the connector arms 177 can pass under the squeeze plates 149 of the inner cannula latches 143 with the flexible connector fingers 179 at approximately the 4 and 10 o'clock orientations. This positions the connector fingers 179 on the clockwise side of the rotational and longitudinal ramps 155 and 157 when the connector 160 is connected to the outer and inner cannulas 100 and 130 . The leading faces 183 of the connector fingers 179 are beveled so that, as the flexible connector 160 is moved longitudinally into the tapered tubular extension 139 of the inner cannula 130 , the fingers 179 will be spread apart by and slide across the ring 121 , on the outer cannula 100 . Once the fingers 179 pass the ring 121 they resiliently close to secure the flexible connector 160 to the outer cannula 100 . The inner cannula collar 135 is sandwiched between them. [0072] As best seen in FIG. 12 , the interior surfaces of the connector arms 177 are provided with longitudinal grooves 185 and the counterclockwise inside edges of the connector arms 177 are provided with longitudinal bevels 187 . To remove the flexible connector 160 from the outer and inner cannulas 100 and 130 , the connector 160 is rotated counterclockwise, as indicated by the rotational arrows 189 , using the thumb and forefinger on the posts 175 . As the connector 160 rotates, the longitudinal bevels 187 on the connector arms 177 ride on the rotational ramps 155 on the inner cannula collar 135 to unlatch the connector fingers 179 from the collar 135 . The rotation is limited to the point of abutment of the inner cannula and connector fingers 145 and 179 , whereupon longitudinal beads 159 on the inner cannula collar 135 and grooves 185 on the connector arms 177 engage to provide an audible click indicating that the connector 160 can be longitudinally displaced and disconnected from the outer and inner cannulas 100 and 130 . As the connector 160 is withdrawn in the trailing direction, the connector fingers 179 ride on the longitudinal ramp 157 of the inner cannula collar 135 to assure that the connector fingers 179 cannot relatch during the process. Second Adult Tracheotomy Tube Embodiment [0073] Turning to FIGS. 19-26 , the other type of adult tracheotomy tube is illustrated. The collar 205 of the outer cannula 200 has a hard annular ring 221 which is concentric about the trailing end 207 of the outer cannula tube 201 . The hard tapered tubular extension 223 of the ring 221 narrows toward the trailing end 225 . Top and bottom approximately quarter notches 227 are provided in the outer circumference of the tapered tubular extension 223 at the trailing end of the ring 221 . [0074] The inner cannula 230 applies the principles of the invention to the outer cannula 200 . A soft arced tube 231 extends upwardly and rearwardly from its leading end 223 to a concentric collar 235 on its trailing end 237 . A tapered tubular extension 239 extends in a trailing direction from the collar 235 to a trailing end face 241 of an annular ring 243 on the extension 239 . The outside wall of the extension 239 has annular ridges 245 which complement the annular grooves 229 in the inside wall of the outer cannula tapered extension 223 to secure the inner cannula 230 in place in the outer cannula 200 . A pair of vertically aligned studs 247 are provided on the trailing end face 241 of the inner cannula extension 239 for reasons hereinafter explained. A concentric pull ring 249 is hinged 251 to the bottom of the end face 241 of the extensions 239 to facilitate removal of the inner cannula 230 from the outer cannula 200 . An annular outer flange 253 on the midportion of the inner cannula arced tube 231 helps to hold the inner cannula tube 231 concentrically within the outer cannula tube 201 . [0075] The flexible connector 260 for use with the above outer and inner cannulas 200 and 230 has a leading end adapter 261 , best seen in FIGS. 21-24 . The leading end adapter 261 has a hard outer sleeve 267 with a soft tube liner 269 . The trailing end 271 of the sleeve 267 is of narrower diameter so as to provide a connecting ring 273 for reasons hereinafter explained. The outer sleeve 267 has a corrugated surface 275 to facilitate manipulation of the flexible connector 260 . Diametrically vertically opposed arms 277 with radially inwardly extending fingers 279 at their leading ends are defined by longitudinal slots 281 in the sleeve 267 . The fingers 279 are contoured to engage in the opposed notches 227 in the outer cannula tapered tubular extension 223 . As best seen in FIG. 23 , valleys 283 in the inner and outer surfaces of the arms 277 at their trailing ends permit the arms 277 to flex easily. As best seen in FIGS. 21 and 22 , the leading face of the connecting ring 273 of the leading end adapter 261 has notches 285 which receive the studs 247 on the trailing end face 241 of the inner cannula 230 . The notches 285 extend clockwise from the point of longitudinal insertion of the studs 247 to stops 287 . Counterclockwise rotation of the leading end adapter 261 of the connector 260 , indicated by the rotational arrows 289 on the sleeve 267 , is terminated by the studs 247 striking the stops 287 . At this point, the connector arms 277 will have flexed sufficiently to disengage the connector fingers 279 from the notches 227 in the outer cannula extension 223 so that the connector 260 can be longitudinally withdrawn from the outer and inner cannulas 200 and 230 . Child Tracheotomy Tube Embodiment [0076] Turning to FIGS. 27-35 , the child's tracheotomy tube is illustrated. As best seen in FIG. 27 , the collar 305 on the soft tube 301 has a concentric annular ring 321 extending in a trailing direction with a soft tapered extension 323 extending in a trailing direction from the ring 321 . The extension 323 has annular ridges 325 in its circumference and a beveled flange 327 with an annular groove 329 in its trailing end face. A hard sleeve 331 is tapered to concentrically cover the tapered extension 323 . The hard sleeve 331 has a pair of annular flanges 333 at its leading end defining an annular groove 335 therebetween. When the sleeve 331 is mounted on the soft tapered extension 323 , the leading face 337 of the sleeve 331 abuts the trailing end face of the ring 321 on the collar 305 and the trailing end face 341 of the sleeve 331 abuts the leading end face of the beveled flange 327 on the tapered extension 323 , locking the hard sleeve 331 in place on the soft extension 323 . [0077] Looking at FIGS. 27-35 , the flexible connector 360 for use with the cannula 300 has a leading end adapter 361 , best seen in FIGS. 29-32 . The leading end adapter 361 is a clamshell-type grip with bottom and top shells 367 and 369 . The shells 367 and 369 extend from a trailing end face 371 on a trailing connecting ring 373 to a leading connecting ring 375 separated by a narrower body 377 . As best seen in FIG. 35 , the shells 367 and 369 are defined by a radial cut 379 splitting the top half of the trailing connecting ring 373 and a horizontal diametric cut 381 extending from the radial cut 379 through the leading connecting ring 375 . The shells 367 and 369 are hinged 383 at the top of the radial cut 379 . The leading connecting ring 375 has grooves 385 defining a ridge 387 which will engage in the groove 335 on the leading end of the hard sleeve 331 mounted on the soft tapered tubular extension 323 of the cannula 300 . A tapered nozzle 397 extends in a leading direction from the leading face of the trailing connecting ring 373 . The nozzle 397 has an annular bead 399 on the perimeter of its leading face. A concentric bead 401 is provided on the leading face of the trailing connecting ring 373 around the nozzle 397 . The annular bead 399 on the nozzle 397 abuts the inside wall of the soft tapered tubular extension 323 of the cannula 300 and the concentric bead 401 on the leading connecting ring 375 seats in the groove 329 on the leading face on the beaded flange 327 of the soft tapered tubular extension 323 of the cannula 300 when the soft extension 323 with the hard sleeve 331 are longitudinally inserted into the clamshell of the connector 360 . As best seen in FIGS. 29-32 , flexibly resilient supports 403 extend radially outwardly from the top shell portion of the body 377 at the diametric cut 381 . Arms 405 extend downwardly, considering the clamshell in the closed condition of FIG. 35 , from each of the supports 403 to fingers 407 which extend diametrically inwardly from the arms 405 . The fingers 47 have beads 409 on their upper inside edges. The arms 405 also extend upwardly from the supports 403 to corrugated squeeze plates 411 which aid in manually flexing the arms 405 between the thumb and forefinger. To cooperate with the fingers 407 , L-shaped lugs 413 extend upwardly, again considering the clamshell in the closed condition of FIG. 35 , from the bottom shell portion of the body 377 at the diametric cut 381 . When the top shell 369 is closed on the bottom shell 367 , the fingers 407 snap under the lugs 413 and the beads 409 engage the inside edges of the lugs 413 to assure a stable engagement. [0078] The above described flexible connector 360 with the clamshell-type leading end adapter 361 accomplishes the objects, aims and advantages of the present invention when used with known outer cannula only or child tracheotomy tubes 300 . Such single cannula tracheotomy tubes 300 , however, have hereinbefore noted deficiencies of their own. In particular, looking at FIG. 27 , the hard sleeve 331 replaces the manufacturer's original hard sleeve (not shown) which rotates on the soft extension 323 to allow some freedom of motion of the patient. This configuration focuses the dissipation of rotational forces at the patient end of the tracheotomy system. Moreover, the original and the replacement hard sleeve 331 are locked on the soft extension 323 by the beveled flange 337 and cannot be removed, for cleaning or other reason, without use of a tool and application of force to the tracheotomy tube and, consequently, the patient. Therefore, turning to FIG. 36 , an improved child's tracheotomy tube 500 and connector 560 are illustrated which transfer the rotational capability to the connector 560 , so that freedom of motion is maintained and the connector 560 can be disconnected from the tracheotomy tube 500 without applying rotational or longitudinal forces to the tracheotomy tube. [0079] As seen in FIG. 36 , the tracheotomy tube 500 is a unitary arrangement of a soft tube 501 formed by a silicone case on a coil of titanium or other non-iron based wire so that the improved tracheotomy tube 500 is compatible with MRI procedures. The soft tube 501 trails to a neck plate 515 with an annular ring 521 on its trailing side. A soft extension 523 trails concentrically from the annular ring 521 to a trailing annular flange 525 having the same diameter as the annular ring 521 . Preferably, the soft extension 523 is covered up to the soft flange 525 by a hard sleeve 531 which is permanently fused to the soft extension 523 . The annular ring 521 has a plurality of circumferential sets of diametrically opposed serrations 543 , preferably and as shown transverse to and straddling the 3 and 9 o'clock diametric plane of the annular ring 521 . [0080] Continuing to look at FIG. 36 , the flexible connector 560 has a leading end adapter 561 and a trailing end adapter 563 on the ends of an intermediate tube 565 . The leading end adapter 561 is a hard sleeve with a trailing end annular wall 567 . A pair of diametrically opposed latches 571 have flexible supports 573 which extend radially outwardly from the leading end adapter 561 to forwardly extending arms 575 with inwardly radially extending fingers 577 . As shown, the latch fingers 577 straddle the 3 to 9 o'clock plane so as to be co-operable with the serrations 543 on the tracheotomy tube annular ring 521 . This orientation is preferred so as to reduce the likelihood of the application of pressure by the chin and chest of the patient to the latches 571 . The fingers 577 are engagable in the serrations 543 on the tracheotomy tube annular ring 521 to secure the connector 560 to the tracheotomy tube 500 when the soft flange 525 of the tracheotomy tube extension 523 is in abutment with the trailing end annular wall 567 of the leading end adapter 561 . The walls 545 formed by the annular ring 521 at the ends of the serrations 543 prevent any significant rotation of the leading end adapter 561 in relation to the tracheotomy tube 500 . The plurality of circumferential sets of serrations 543 allows tolerance for the lengths of the leading end adapter 561 and the tracheotomy tube extension 523 . The latches 571 also have rearwardly extending squeeze plates 579 which provide suitable surfaces and leverage for the thumb and forefinger to apply pressure to flex the supports 573 and spread the latch fingers 577 so that the connector 560 can be disengaged from the tracheotomy tube 500 without need for exertion of excessive rotational or axial force on the tracheotomy tube 500 . [0081] The trailing end adapter 563 has a hard annular ring 581 on its leading end with a tubular concentric rearward extension 583 . The extension 583 has an outer annular groove 585 on its mid-portion, an annular flange 587 on its outer trailing end and a plurality of slots 589 extending axially in its wall from its trailing end toward the groove 585 to provide a plurality of flexible fingers 591 with beveled tips 593 . An O-ring 595 is seated in the groove 585 . A sleeve 597 has a diameter suitable for sliding over the beveled tips 593 of the fingers 591 to radially depress the fingers 591 toward each other and receive the sleeve 597 fully on the extension 583 . The sleeve 597 has an inner annular groove 599 , preferably of cross-section which complements the cross-section of the beveled tips 593 on the trailing end of the sleeve 597 . When the sleeve 597 is fully on the extension 583 , the fingers 591 spread outwardly and the beveled tips 593 engage in the complemental groove 599 to prevent the sleeve 597 from sliding off the extension 583 . The sleeve 597 is free to rotate on the extension 583 , rotation being facilitated by the O-ring 595 . The outer diameter of the sleeve 597 is tapered toward its trailing end to facilitate connection to the ventilator tube (not shown). Third Adult Tracheotomy Tube Embodiment [0082] Turning to FIGS. 37-45 , an adult tracheotomy tube embodiment is illustrated which includes an inner cannula 630 and a flex connector 660 for use with an outer cannula 600 which is a modification of the outer cannula 100 of the first adult tracheotomy tube of FIGS. 1-18 . Looking at FIG. 38 , this modified outer cannula 600 , similar in many respects to the outer cannula 100 , has an arced tube 601 which extends from its leading end 603 to a collar 605 , seen in FIG. 39 , at its trailing end 607 . On the collar 605 is an outer annular flange 609 with a trailing portion 611 and a leading portion 613 . As best seen FIGS. 41 and 42 , the leading portion 613 of the flange 609 has recessed upper and lower seats 615 and the flange 609 is divided into upper and lower portions defined by leaves 617 which extend outwardly from the flange 609 above and below the seats 615 . Between the leaves 617 , the flange 609 provides side seats 619 . [0083] The known inner cannula (not shown) presently used with the above-described known outer cannula 600 functions similarly to other known inner cannulae in that it is intended to be securely latched to the outer cannula 600 and to be and slip connected to the leading end of its ventilator tube connector. The slip connection is the result of longitudinal insertion of the trailing end of the inner cannula (not shown) into the leading end of the ventilator tube connector, the ventilator tube connector and the inner cannula being frictionally held in this relationship. Thus, the known combination of these inner and outer cannulae requires the exertion of longitudinal forces to create or terminate the frictional condition necessary to slip connect the inner cannula to the ventilator tube connector of the assembly and to separate them after they have been connected. Furthermore, this slip connection achieved by friction does not reduce the likelihood of inadvertent separation of the ventilator tube connector from the tracheotomy tube. [0084] Turning to FIG. 37 , an improved inner cannula 630 for use with the outer cannula 600 is illustrated. The inner cannula 630 has an arced tube 631 extending from its leading end 632 to a collar 633 , best seen in FIG. 40 , at its trailing end 634 . As seen in FIG. 37 , the inner cannula 630 also has a tubular extension 635 at its trailing end 634 . The extension 635 includes an inner soft sleeve 636 trailing from the collar 633 . The soft sleeve 636 is contained within a hard outer sleeve 637 , the outer surface of which is preferably narrowingly tapered from the collar 633 to its trailing end face 638 . As best seen in FIG. 44 , the inside wall of the hard outer sleeve 637 and the outside wall of the soft inner sleeve 636 have alternating splines and grooves 639 to prevent rotation of the hard outer sleeve 637 about the soft inner sleeve 636 . Looking again at FIG. 37 , the leading end of the hard outer sleeve 637 has a pair of opposed latches 641 for coupling the inner cannula 630 to the outer cannula 600 . Each of the latches 641 has a base 642 on the outer wall of the hard sleeve 637 with a resiliently flexible post 643 which acts as a fulcrum for operation of the latch 641 . Squeeze plates 644 extending rearwardly of the fulcrum 643 are used to manipulate fingers 645 which are contoured to engage with the side seats 619 on the outer cannula flange 609 , as seen in FIG. 42 . The leading faces 646 of the fingers 645 are beveled and the width of the squeeze plates 644 and fingers 645 is such that the latches 641 can be inserted between the opposed leaves 617 of the outer cannula flange 609 , as seen in FIG. 38 . The bases 642 of the latches 641 have outwardly extending posts 647 which are cooperable with strikers 648 which extend inwardly from the squeeze plates 644 to limit the stroke of the squeeze plates 644 . When the cannulae 600 and 630 are connected, the leaves 617 on the outer cannula flange 609 limit rotation of the inner cannula 630 within the outer cannula 600 so that the inner and outer cannulae 600 and 630 cannot be separated inadvertently, but only by intentional operation of the latches 641 to release the outer cannula 600 . [0085] As best seen in FIGS. 40, 41 and 45 , the outer surface of the hard sleeve 637 of the inner cannula 630 has a pair of radially extending flanges 651 , as shown angularly aligned between the latches 641 and positioned axially rearwardly thereof. Each of the inner cannula flanges 651 has side ramps 652 and a rear ramp 653 defining a U-shaped retaining seat 654 . As best seen in FIG. 45 , the side ramps 652 are tapered away from each other on the inside of the seat 654 and, as best seen in FIG. 39 , the rear ramp 653 is tapered toward the leading end of the hard sleeve 637 . Looking at FIG. 44 , directional arrows 655 on the rear ramps 653 point axially to the rear centers of the rear ramps 653 . [0086] In FIGS. 37, 39 and 40 , the flex connector 660 for use with the inner cannula 630 is shown disconnected from the inner cannula 630 . As with the previously described connectors 160 , 260 , 360 and 560 , the flexible connector 660 has a leading adapter 661 , a trailing end adapter 663 and a tubular member 665 extending between the adapters 661 and 663 . [0087] The flex connector 660 has a leading end tubular portion 669 and a trailing end tubular portion 671 on opposite ends of the accordion-type flexing tubular member 665 . The end portions 669 and 671 of the flexing tubular member 665 line the inside walls of the hard adapters 661 and 663 . The leading end tubular portion 669 has an outer flange 672 on its leading rim and a wider outer diameter 673 proximate its trailing end. The trailing end tubular portion 671 has a trailing end portion 666 with an outer flange 668 . The flexing tubular member 665 allows the connector 660 to expand and contract in accordion fashion and to bend up to approximately 90 degrees or more. [0088] The leading end adapter 661 of the connector 660 is a hard sleeve 667 with annular seats 662 and 664 in its leading and trailing faces. The softer leading end tubular portion 669 is force fitted into the hard sleeve 667 and the outer annular flange 672 and wider diameter 673 on the end portion 669 engage in the annular seats 662 and 664 on the hard sleeve 667 to prevent the leading end adapter 661 from sliding off the leading end tubular portion 669 of the flex connector 660 . [0089] The trailing end adapter 663 of the connector 660 is a hard sleeve 692 with a leading outer annular flange 693 and a larger inner diameter 694 on its trailing portion 695 . The trailing end adapter 663 is manipulable by use of the annular flange 693 on its hard sleeve 692 to press the hard sleeve 692 into the leading end of the ventilator tube. The flexing tubular member 665 allows this to be accomplished without exertion of undue axial force on the cannulae 600 and 630 or the patient. The softer trailing end tubular portion 671 is force fitted into the hard sleeve 692 and the annular flange 668 impinges upon the change in inner diameter 694 to prevent the trailing end adapter 693 from sliding off the trailing end tubular portion 671 of the flex connector 660 . [0090] The outer surface of the hard outer sleeve 667 of the leading end adapter 661 has a plurality of longitudinal ridges 675 to facilitate manipulation and rotation of the leading end adapter 661 . A pair of resiliently flexible arms 677 extend forwardly of the leading end adapter 661 and are angularly positioned for alignment with the retaining seats 654 formed in the flanges 651 on the outer surface of the hard sleeve 637 of the inner cannula tubular extension 635 . The arms 677 are fixed at one end on the hard outer sleeve 667 of the flex connector 660 , extend longitudinally to posts 682 which space the arms 677 radially outwardly from the hard outer sleeve 667 and extend forwardly from the posts 682 . As best seen in FIG. 39 , the arms 677 have beveled leading faces 679 which are cooperable with the rear ramp 653 on the inner cannula tubular extension 635 to spread the arms 677 when the leading end adapter 661 is slipped onto the inner cannula tubular extension 635 . The sidewalls 684 of the fingers 678 are also beveled, as best seen in FIG. 43 . When the fingers 678 are engaged in the retaining seats 654 of the inner cannula flange 651 , the beveled finger sidewalls 684 cooperate with the beveled interior side ramps 652 of the retaining seats 654 in the inner cannula flanges 651 and spread the arms 677 during rotation of the leading end adapter 661 . Thus, disengagement of the flex connector leading end adaptor 661 from the inner cannula 630 is accomplished by use of rotational motion of the adapter 661 . [0091] As shown, the leading end adapter 661 has axial directional arrows 685 on its arms 677 which will align with the axial arrows 655 on the rear ramps 653 of the inner cannula flanges 651 when the fingers 678 are aligned to engage in the retaining seats 654 . The leading end adapter 661 is also provided with rotational arrows 687 as a reminder that disengagement of the flex connector 660 from the inner cannula 630 is accomplished by exertion of rotational rather than axial forces on the leading end adapter 661 . [0092] The improved coupling 660 and its leading end adaptor 661 have been described in relation to connecting an inner cannula 630 to a ventilator tube. However, the coupling 660 could be used to connect any air supply to any of a variety of respiratory support devices if they are provided with radially outwardly extending flanges. Such devices include, but are not limited to, tracheotomy tube cannulae, endotracheal tubes, laryngeal mask apparatus, combitubes, airway pressure masks, resuscitation bags, and ventilator connectors such as elbows and step-up and step-down connectors and heat-moisture exchangers. Common Connector Components [0093] Each of the flexible connectors 160 , 260 , 360 , 560 and 660 has its own unique leading end adapter 161 , 261 , 361 , 561 and 661 as above described. The trailing end adapters 163 , 263 , 363 and 663 and intermediate tubes 165 , 265 , 365 and 665 for the flexible connectors 160 , 260 , 360 and 660 , used with existing adult tracheotomy tubes 100 , 200 300 and 600 are substantially the same. The trailing end adapters 163 , 263 , 363 and 663 have hard tubular extensions 193 , 293 , 393 and 693 with annular flanges 195 , 295 , 395 and 695 to facilitate manipulation of the connectors 160 , 260 , 360 and 660 during attachment to the ventilator. The trailing end adapters 161 , 261 , 361 and 661 are fixed to the trailing ends of their intermediate tubes 165 , 265 , 365 and 665 , also as by ultrasonic welding. [0094] The intermediate tube 565 used with the improved child's tracheotomy tube 500 is substantially the same as the intermediate tubes 165 , 265 , 365 and 665 of the other flexible connectors 160 , 260 , 360 and 660 . The leading and trailing end adapters 561 and 563 are different. Common Operational Features of the Embodiments [0095] For each of the different tracheotomy tube outer cannulas 100 , 200 and 300 , the corresponding coupling 160 , 260 and 360 has a leading end adapter 161 , 261 and 361 which interlocks with its respective tracheotomy tube outer cannulas 100 , 200 and 300 preventing them from inadvertently axially displacing from each other. However, non-axial force applied to the unlatching mechanism disengages the associated adapter 161 , 261 or 361 from its tracheotomy tube outer cannula 100 , 200 or 300 so that the coupling 160 , 260 or 360 can be axially displaced without exertion of excessive axial force on the system and the patient. [0096] Similarly, for the improved tracheotomy tube 500 , its corresponding coupling 560 has a leading end adapter 561 which interlocks with its tracheotomy tube 500 to prevent them from inadvertently axially displacing from each other. However, non-axial force applied to the unlatching mechanism disengages them so that the coupling 560 can be axially displaced without exertion of excessive axial force on the system and the patient. While the improved tracheotomy tube 500 has been described as being intended for children, this designation is based on the heretofore accepted view that an adult tracheotomy tube has inner and outer cannulas and that a child's tracheotomy tube has a single cannula. However, the improved cannula 500 can be sized for use by children or adults. [0097] For the third adult tracheotomy tube outer cannula 600 , the corresponding coupling 660 has a leading end adapter 661 which interlocks with its tracheotomy tube inner cannula 630 , preventing them from inadvertently axially displacing from each other. However, non-axial force applied to the unlatching mechanism disengages the adapter 661 from its tracheotomy tube inner cannula 630 so that the coupling 660 can be axially displaced without exertion of excessive axial force on the system and the patient. [0098] Thus, it is apparent that there has been provided, in accordance with the invention, a ventilator to tracheotomy tube coupling that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art and in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit of the appended claims.

A coupling for connecting an air supply to a respiratory support device has a latching mechanism which prevents the coupling from inadvertently axially displacing from the respiratory support device after they have been mated in a pneumatically discrete path. Non-axial forces are used to disengage the coupling from the respiratory support device. The coupling may include a trailing end adapter which permits rotation of the coupling relative to the air supply rather than to the respiratory support device.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority from U.S. Provisional Patent Application No. 60/550,415, filed Mar. 5, 2004. The contents of these applications are incorporated herein by reference. STATEMENT ON FEDERALLY SPONSORED RESEARCH N/A FIELD OF THE INVENTION The present invention relates to fluid movement systems and in particular to improved operation and maintenance of such systems utilizing a pressure monitor. BACKGROUND OF THE INVENTION In one form of liquid chromatography sample injection, the fluid path for handling the sample is pressurized. Such pressurization improves the sample movement speed by limiting the risk of vaporization of the sample. In order to control the degree of pressurization in such a system, a pressure gauge is typically installed in line with the pressure source. This pressure gauge is typically used in a feedback mode to control the generated pressure. The increased pressure increases the likelihood of leakage at each of the multiple connection points that comprise the fluid path(s). Leaks may occur due to wear internal to a component, when a component is replaced due to faulty installation and also due to failures in joints at unexpected areas. For fluid movement systems that have small diameters, the volume of fluid leaking may be large enough to distort performance and yet small enough that it evaporates or is in some other way rendered invisible to inspection. A system controller can use the output of the pressure gauge to tell that there is fluid leakage in the system when there is a greater than normal pressure drop in the system. However, this technique does not help to isolate the source of the leak. Certain techniques may limit the search area for the leak rather than eliminate leak target areas. Previous systems have been able to determine that there is a leak in the system, but have not been able to identify the location of the leak nor identify points without leaks. Therefore, repair operations have typically involved disconnecting all connections, replacing many active components and essentially rebuilding the fluid movement system when a leak became too severe. Because of the extent of the repair activities, lesser leaks were allowed to remain until the system could be brought down for the major replacement operation. Many pressurized injection systems require a cleaning cycle between successive usage cycles. In order to assure adequate cleaning, a set volume of cleaning fluid must pass through the system. In order to lessen the need for user interaction, the systems are set up for the extremes of operation. Since viscous liquids will take longer to flow through the system in a cleaning cycle, sufficient time is allocated for the most viscous fluid anticipated to execute the cleaning cycle. For all other fluids, some part of this time is wasted. If the viscosity of the fluid were known, the operation of the cleaning cycle could be tailored to optimize the fluid path cleaning cycle. Diagnostics for fluid systems would allow inefficient and/or failing components to be identified. One set of information available is the expected pressure and pressure decay within a fluid system. If the actual pressures experienced by the system can be measured, comparisons can be conducted against the expected values. Repairing a leak involves first finding it. Identifying the leakage point is beneficial because the repair time is minimized. Another time when checking for leaks is important is when a component is replaced and reconnected with the fluid system. SUMMARY OF THE INVENTION A device for monitoring pressure in a fluid system comprises a pressure monitor for placement in communication with a fluid in the fluid system and a control means for receiving a signal representative of the measured pressure and comparing that measured pressure to a reference. The pressure monitor generates the signal representative of the measured pressure and the control means generates an error message or performs an action if a difference between the measured pressure and the reference exceeds a predetermined value. One fluid system well adapted to this monitoring is an autosampler for a liquid chromatography system. In one embodiment, a fluid system is comprised of a controllable pressure source, at least one fluid path section having first and second ends and at least one fluid connection means. The fluid system is filled with fluid and monitored by the device for monitoring pressure. The controllable pressure source creates a source pressure on the fluid in response to a pressure command signal from the control means. The fluid connection means has a plurality of ports for interconnection with the system and is capable of assuming a first position where fluid flows between at least a first port and the second port and a second position in which fluid does not flow between any of the first ports and the second port. The system is interconnected with one port of the fluid connection means connected to an end of the fluid path section and the controllable pressure sources connected to the second end of the fluid path section. The fluid connection means is responsive to a connect command signal to assume the first position and a disconnect command signal to assume the second position. The monitoring device is placed in communication with the fluid in the fluid path section. The monitoring device sends the signal representing the measured pressure to the control device for comparison with the known source pressure. The control means generates an error message if a difference between the measured pressure and the source pressure exceeds a predetermined value. In a preferred embodiment, the control means is further for sending a connect command signal and a disconnect command signal to the at least one fluid connection means for controlling the connection means to assume the first and second positions. In addition, the control means is further for sending a pressure command signal to the controllable pressure source to cause the controllable pressure source to generate a source pressure. Preferably, the fluid system has one of the fluid connection means in the second position, creating a closed fluid system. Then the control means monitors the measured pressure in the closed fluid system over time to detect a degradation of the measured pressure, which is indicative of a lack of fluid sealing integrity. Preferably, the controllable pressure source is a syringe, preferably a metering syringe, positionable by the pressure command signals to create the source pressure on the fluid. Further, at least one fluid connection means is preferably a multiport valve having at least a first port and a second port. In the first position, fluid flows between the first port and the second port. In a preferred embodiment, the fluid system is a liquid chromatography system and more particularly, a liquid chromatography sample injector system. In operation, the control means sends a pressure command signal to the controllable pressure source to create a predetermined source pressure and reports an error if the measured pressure does not reach a predetermined value within a specified period of time. In a preferred embodiment, the control means has a library of entries that comprise command signals to be sent, time between sending the command signals and taking readings and normal measured pressure values. The control means transmits the command signals for one entry and compares a set of received measured pressures to the normal measured pressure values. Differences that exceed a preset threshold cause a report to be sent. In one embodiment, a fluid system that is to be monitored for errors is comprised of a monitored fluid path section having a first end and a second end and first and second fluid subsystems connected to the first and second ends respectively. Each fluid subsystem comprises at least one fluid path section, at least one fluid connection means and at least one controllable pressure source. The fluid path sections in the fluid subsystems have a section first end and a section second end. The fluid connection means have a plurality of ports for interconnection. At least one of the ports is connected to a fluid path section end for forming the fluid subsystem. The fluid connection means are responsive to a connect command signal to assume a first position wherein fluid flows between at least two of the ports and responsive to a disconnect command signal to assume a second position in which fluid does not flow between any of the plurality of ports. The controllable pressure source is connectable to the at least one section second end. The controllable pressure source is responsive to a pressure command signal to create a source pressure on fluid in the fluid subsystem. The first fluid subsystem is connected to the first end of the monitored fluid path section and the second fluid subsystem is connected to the second end of the monitored fluid path section. The pressure monitor is in communication with the monitored fluid path section. The control means looks for leakage in the system by monitoring the measured pressure over time, looking for a degradation that would be indicative of a leak. The control means controls the pressure and configuration of the fluid system while monitoring the measured pressure. The control means executes a set of instructions that specify connect and disconnect command signals that define a configuration and pressure command signals for setting the source pressure. The instructions further specify the normal measured pressure for each entry so that actual measured pressure can be compared to the normal pressure. Degradations in the monitored measured pressure are indicative of reduced fluid integrity of the fluid system configuration. When trying to find leaks, the control means issues at least one connect command signal and at least one disconnect command signal to form a first closed fluid circuit in the fluid system. The control means then pressurizes the first closed fluid circuit using the controllable pressure source and monitors the pressure. If the pressure becomes established in the circuit and remains stable, the control means concludes that the components and interconnections making up the first closed fluid circuit likely are not leaking. The control means can then expand the length of subsequent closed fluid circuits and incrementally add to the list of non-leaking components and interconnections. It should be understood that each of the fluid connection means can be composed of an interconnection of fluid connection means. When the monitoring device can control the configuration of the fluid system by selectively isolating parts of the fluid system from the rest using the fluid connection means, successive fluidic integrity tests on different parts of the fluid system lead to isolation of a leaking component. By starting with a subsystem of the fluid system with few components, and verifying that there are no leaks in that part, the control means has a basis for comparison as further components are added. Each successive subsystem incorporates some previously tested components and some untested parts, allowing the control means to identify likely leaking components. The device is preferably used to determine a parameter of a fluid in the fluid system. The control means that has been provided with reference information based on the diameters of the fluid path components, the length of a reference flow path and the friction factor of the reference flow path, can use that information with the measured pressure of the fluid moving past the monitor point at a known flow rate to determine the viscosity of the fluid. The viscosity can further be used to calculate the flow rate that can be used in the wash cycle without exceeding a predetermined parameter of the system. Preferably, the device is used with fluid system to optimize a fluid path wash cycle. In an embodiment of a fluid path wash cycle using the device, one controllable pressure source comprises a first wash syringe containing a first wash fluid. A first fluid connection means is used to connect the first wash syringe to the fluid path to be flushed. After sending connect and disconnect command signals to the necessary fluid connection means for configuring the system for flushing, including creating the fluid path to be flushed, the control means connects the first wash syringe through the appropriate connection means. The control means monitors the measured pressure as the first wash syringe starts delivering wash fluid. When the measured pressure equals a first wash pressure that was calculated based on the viscosity of the fluid, the control means stabilizes the flow rate of fluid being delivered. Thereafter, the control means allows the precise volume of wash fluid needed to effect a complete wash to flow through the system in a timely manner. This washing mechanism saves time over systems that flow wash fluid based on a worst case viscosity. For systems that require two levels of washing, the controllable pressure source comprises a first and a second wash syringe filled respectively with a first wash fluid and a second wash fluid. Further the connection means is able to select between the first and second wash syringes. After washing with the first fluid, the control means repeats the process with the second wash syringe until a predetermined volume of second wash fluid has been pushed through the fluid system to be cleaned. Methods of performing operations on a fluid system are built around the device for measuring pressure. In a method of monitoring pressure, the fluid system is comprised of at least one fluid path section having a first end and a second end and at least one controllable pressure source connected to the first end of the at least one fluid path section. Each controllable pressure source is responsive to a pressure command signal to create a source pressure in the at least one fluid path section. The fluid system is connected so that it forms a fluid path filled with a fluid. The method comprises providing the device comprising a pressure monitor for placement in communication with the fluid in a first path section and a control means. The pressure monitor generates a signal representative of a measured pressure that is received by the control means. The control means sends signals to the fluid system. The pressure monitor is placed in communication with the fluid in the fluid path. The control means issues a pressure command signal to the controllable pressure source to cause it to generate the source pressure in one fluid path section. The control means compares the measured pressure to the source pressure, and generates an error message if the difference between the measured pressure and the source pressure exceeds a predetermined value. Preferably, the method determines whether the pressure in a pressurized system is established within a specified time after a source pressure is applied. In addition, a method to determines whether a decay in the pressure falls within prescribed limits. The fluid system further comprises at least one fluid connection means having a plurality of ports for interconnecting with the at least one controllable pressure source and the at least one fluid path section. The fluid connection means is capable of assuming at least a first position wherein fluid flows between at least two of the plurality of ports in response to a connect command signal and a second position in which no fluid flows in response to a disconnect command signal. A preferred fluid connection means is a multiport valve. A preferred system comprises a first fluid connection means having at least a first port and a second port, a second fluid connection means having at least a first port and a second port, a first fluid path section and at least one controllable pressure source. A controllable pressure source is connected to the first port of the first fluid connection means and the second port of the first fluid connection means is connected to a first end of the first fluid path section. The second end of the first fluid path section is connected to the first port of a second connection means. The method further comprises sending at least one connect command signal to the first fluid connection means to place the first connection means in the first, open position. And sending at least one disconnect command signal to the second fluid connection means to place the second fluid connection means in the second, closed, position. This arrangement of fluid connection means creates a closed system that should maintain an applied pressure. The control means sends a pressure command signal to the controllable pressure source to generate a predetermined source pressure. The control means compares the measured pressure to the predetermined source pressure and reports an establishment error if the difference is greater than a first allowed amount. If no establishment error occurs, the method preferably further waits a predetermined length of time and compares the current measured pressure to the predetermined source pressure. If the decay in pressure is greater than a second allowed amount, a leak error is reported. The method above is preferably extended to deal with more complex fluid systems. The control means is provided with a library of entries comprising sets of command signals for controlling connection means and pressure sources and sets of normal pressure values and allowable pressure decay rates. The control means selects one entry, issues the command signals from that entry and compares the measured pressures to the normal pressure values. The control means reports significant differences. Preferably, the method has the control means issue connect, disconnect and pressure command signals to the fluid system and identify degradations in the measured pressure indicative of reduced fluid integrity. The method is adaptable to other configurations. For instance, when a second controllable pressure source is connected to the second port of the second fluid connection means, the method has further steps. The control means sends at least one connect command signal and disconnect command signal to the first and second fluid connection means to place the first fluid connection means in the second position and the second fluid connection means in a different first position where fluid flows between the first fluid path and the second controllable pressure source. The control means sends at least one pressure command signal to the second controllable pressure source to set the source pressure. The control means monitors the signal from the pressure monitor and identifies additional non-leaking components based on the stability of the measured pressure over time. When a third controllable pressure source is connected to a third port of the second fluid connection means, the method is extended similarly to identify further non-leaking components. The method is applicable and provides additional information when an additional controllable pressure source is located at a different fluid connection means in the fluid circuit. In particular, when a second controllable pressure source is connected to a second port of the first fluid connection means, the control means interconnects the fluid circuit by sending connect command signals to the first fluid connection means to assume a first position in which fluid flows between the first fluid path and the second controllable pressure source. In addition, the control means sends disconnect command signals to the second fluid connection means to assume a second position blocking the fluid path. Then the control means sends a pressure command signal to the second controllable pressure source to pressurize the fluid path. By monitoring the signal from the pressure monitor, the control means identifies additional non-leaking components based on the stability of the measured pressure over time. Preferably, the first fluid connection means comprises an interconnection of a plurality of fluid connection means and the second fluid connection means comprises an interconnection of a plurality of fluid connection means. BRIEF DESCRIPTION OF THE DRAWINGS The above noted and other features of the invention will be better understood from the following detailed description, when considered in connection with the accompanying drawings, in which: FIG. 1 is a schematic of an implementation of the inventive device; FIG. 2A is a schematic of the device of FIG. 1 in a fluid system; FIG. 2B is an illustration of the fluid system of FIG. 2A with command signals connected to components of the fluid system; FIG. 3 is an illustration of a fluid system comprising two connected fluid subsystems being monitored by the device of FIG. 1 ; FIG. 4 is an illustration of the device of FIG. 1 being used to optimize a fluid system wash cycle; FIGS. 5A and 5B illustrate a sequence of tests based on the fluid system of FIG. 3 , wherein FIG. 5A illustrates a first configuration and FIG. 5B illustrates a second configuration; FIG. 6A illustrates a first test configuration of an example; FIG. 6B illustrates a second test configuration of an example; FIG. 6C illustrates a third test configuration of an example; FIG. 6D illustrates a fourth test configuration of an example; and FIG. 6E illustrates the failures identified by the tests of FIGS. 6A-6D . DETAILED DESCRIPTION As used herein, the term “leak” refers to a hole, crack or opening through which fluid escapes in a manner not intended by the user. The leak may be totally internal. That is, the fluid escapes from an area of high pressure to an area of low pressure within the apparatus. Or, such leak may be external, allowing fluid to escape from the confines of the hydraulic circuit. Leaking fluids could represent a safety concern, the detection of which would be very useful. As used herein, “pressure monitor” comprises any device for measuring pressure, including strain gauges and pressure transducers. The output of the pressure monitor, representing a measured pressure, may be an analog signal that is digitized before being input to a control means or may be a digitized representation of the measured pressure. Fluid connection means are devices for closing, opening or directing fluid flow. In many cases a fluid connection means is a valve. Typical valves include mechanical check valves and active valves. Mechanical check valves are responsive to pressure. Active valves receive a signal that directs power means, such as motors, solenoids and the like, to open or close the valve. Cycling valves are capable of selectively opening and closing the flow of fluid from one or more sources or directing the flow to one or more destinations. As used herein, the term “control means” means any processing entity that can receive information signals and send command signals. An embedded microprocessor with memory and an associated input/output section for signal handling is one implementation. Alternately, one of the central processors embedded in an instrument may act as the control means with the memory and input/output sections handling the instrument as well as the device functions. Other central processors, as are known to those skilled in the art, can serve as the control means. A controllable pressure source is a device that can be commanded to exert a defined pressure on a fluid. Such a pressure source may establish a pressure in a closed fluid system. Alternately, the applied pressure will cause a flow rate in an open fluid system. One example of a controllable pressure source is a metering syringe wherein a motor is used to drive the syringe precisely. As illustrated in FIG. 1 , a device 10 for monitoring pressure in a fluid system 18 comprises a pressure monitor 12 for placement in communication with a fluid 16 in the fluid system 18 and a control means 14 for receiving a signal 20 representative of the measured pressure and comparing that measured pressure to a reference. The pressure monitor 12 generates the signal 20 representative of the measured pressure and the control means 14 generates an error message, and/or other signals 22 if a difference between the measured pressure and the reference exceeds a predetermined value. One fluid system well adapted to this monitoring is a an auto sampler for a liquid chromatography system. Turning now to FIG. 2A , a fluid system 18 is comprised of a controllable pressure source 30 , at least one fluid path section 32 having first and second ends 34 , 36 and at least one fluid connection means 40 . The fluid system is filled with fluid 16 and monitored by the device 10 for monitoring pressure. The controllable pressure source 30 creates a source pressure on the fluid 16 in response to a pressure command signal 38 from the control means 14 . The fluid connection means 40 has a plurality of ports 42 , 44 , 46 , 48 for interconnection with the system and is capable of assuming a first position (represented by the dotted line 50 ) where fluid flows between a first port 44 , 46 48 and the second port 42 and a second position (not illustrated) in which fluid does not flow between any of the first ports 44 , 46 , 48 and the second port 42 . The system 18 is interconnected with one port 42 of the fluid connection means 40 connected to an end 34 of the fluid path section 32 and the controllable pressure source 30 connected to the second end 36 of the fluid path section 32 . The fluid connection means 40 is responsive to a connect command signal 52 to assume the first position and a disconnect command signal 54 to assume the second position. These signals may be implemented as separate levels on one signal line, encodings on a line, distinct signals or other means including a combination of the above implementations as is known to one skilled in the relevant art. The monitoring device 12 is placed in communication with the fluid 16 in the fluid path section 32 and sends the measured pressure signal 20 for comparing the measured pressure to the source pressure. The control means 14 does the comparison and generates an error message 22 if a difference between the measured pressure and the source pressure exceeds a predetermined value. As illustrated in FIG. 2B , the control means 14 is further for sending the connect command signal 52 and disconnect command signal 54 to the at least one fluid connection means 40 for controlling the connection means 40 to assume the first and second positions. In addition, the control means 14 is further for sending the pressure command signal 38 to the controllable pressure source 30 to cause the controllable pressure source 30 to generate the source pressure. In an embodiment for testing for leakage, the fluid system has one of the at least one fluid connection means 40 in the second position, blocking fluid passage and creating a closed fluid system. Then, the control means 14 can monitor the measured pressure in the closed fluid system over time to detect a degradation of the measured pressure, which is indicative of a lack of fluid integrity. Preferably, the controllable pressure source 30 is a syringe, preferably a metering syringe, positionable by the pressure command signal 38 to create the source pressure on the fluid 16 . Further, the at least one fluid connection means 40 is preferably a multiport valve having at least a first port and a second port. In the first position, fluid flows between the ports, and in the second position fluid does not flow between any of the ports. When the multiport valve has more than two ports, there may be more than one first position in that in a first first position fluid flows between ports A and B, while in a second first position fluid may flow between ports A and C (or C and D). In a preferred embodiment, the fluid system is a liquid chromatography system and more particularly, a liquid chromatography sample injector system. In operation, the control means 14 sends a pressure command signal 38 to the controllable pressure source 30 to create a predetermined source pressure and reports an error if the measured pressure does not reach a predetermined value within a specified period of time. In a preferred embodiment, the control means 14 has a library of entries that comprise command signals 38 , 52 , 54 to be sent, time and normal measured pressure values. The control means 14 transmits the command signals 38 , 52 , 54 to specified fluid connection means and controllable pressure sources for one entry and compares received measured pressures to the normal measured pressure values. Differences that exceed a preset threshold cause a report to be sent. In one embodiment illustrated in FIG. 3 , a fluid system that is to be monitored for errors is comprised of a monitored fluid path section 60 having a first end 62 and a second end 64 and first and second fluid subsystems 70 , 72 connected to the first and second ends 62 , 64 respectively. Each fluid subsystem 70 , 72 comprises at least one fluid path section 32 , 32 ′, at least one fluid connection means 40 , 40 ′, 40 ″, 40 ′″ and at least one controllable pressure source 30 , 30 ′, 30 ″, 30 ′″. The fluid path sections 32 , 32 ′ have a section first end 34 , 34 ′ and a section second end 36 , 36 ′. The fluid connection means 40 , 40 ′, 40 ″, 40 ′″ have a plurality of ports, for instance ports 41 ′, 43 ′ and 45 ′ of fluid connection means 40 ′. These ports are for interconnecting the system. At least one of the ports 41 ′ is connected to a fluid path section end 36 for forming the fluid subsystem. The fluid connection means 40 , 40 ′, 40 ″, 40 ′″ are responsive to connect command signals 52 , 52 ′, 52 ″, 52 ′″ respectively to assume a first position wherein fluid flows between at least two of the ports and responsive to disconnect command signals 54 , 54 ′, 54 ″, 54 ′″ respectively to assume a second position in which fluid does not flow between any of the plurality of ports. As illustrated in FIG. 3 , each illustrated fluid connection means has three possible first positions—using fluid connection means 40 for example, connecting ports 41 and 43 , 41 and 45 or 43 and 45 —as well the single second position wherein no fluid flows. A controllable pressure source 30 , 30 ′, 30 ″, 30 ″ may be connected to the at least one section second end 34 directly (not shown) or through a fluid connection means. The controllable pressure sources 30 , 30 ′, 30 ″, 30 ′″ are responsive to pressure command signals 38 , 38 ′, 38 ″, 38 ′″ respectively to create a source pressure on fluid in the fluid subsystem. In the figure, each of the controllable pressure sources in connected to an end of the fluid path section 32 , 32 ′ and/or to the monitored fluid path 60 through at least one connection means. The first fluid subsystem 70 is connected to the first end 62 of the monitored fluid path section 60 and the second fluid subsystem 72 connected to the second end 64 of the monitored fluid path section 60 . The pressure monitor 14 is in communication with the monitored fluid path section 60 . The control means 14 controls the pressure and configuration of the fluid system while monitoring the measured pressure. The control means executes a set of instructions that specify connect and disconnect command signals to be sent to define a configuration and pressure command signals for setting the source pressure. The instructions further specify the normal measured pressure for each entry, so that the actual measured pressure can be compared to the normal pressure. Degradations in the monitored measured pressure are indicative of reduced fluid integrity of the fluid system configuration. As an illustration, the control means 14 sends connect and disconnect command signals to the subsystems to create a configuration with one connection means 40 ′ in one subsystem 70 in the second position (closed) and a second connection means 40 ″ in the other subsystem 72 , in the first position (open) so that the fluid is in a closed system comprised of the controllable pressure source 30 ″, connection means 40 , and monitored fluid path 60 and the termination at fluid connection means 40 ′. Then the control means 14 sends a pressure command signal 38 ″ to set the source pressure to a value. By monitoring the signal 20 from the pressure monitor 12 and noting whether the measured pressure remains stable over time, the control means 14 is able to identify non-leaking components. When the monitoring device 10 can control the configuration of the fluid system by selectively isolating parts of the fluid system from the rest using the fluid connection means, successive fluidic integrity tests on different parts of the fluid system lead to isolation of the leaking component. By starting with a subsystem of the fluid system with few components, and verifying that there are no leaks in that part, the control means 14 has a basis for comparison as further components are added. Each successive subsystem incorporates some previously tested components and some untested parts, allowing the control means to identify likely leaking components. The device is further preferably used to determine the viscosity of the fluid currently in the fluid system. Prior to this operation, the fluid system is calibrated to yield a viscosity calibration factor. Thereafter, when a fluid is flowed through the calibrated fluid path at a predetermined flow rate, the viscosity of the current fluid can be determined by multiplying the measured pressure by the viscosity calibration factor. In calibrating the fluid system, using equation (1) is used. η= VΔPD Ref 6 /64 CL ref Q 2   (1) In equation (1), ΔP is the difference from source pressure at the measurement point, and, V, D ref , C, L ref and Q are incorporated in a the viscosity calibration factor from the calibration run. (V is velocity, D ref is the average diameter of the reference fluid path, C is a unit correcting factor, L ref is the length of the reference fluid path, and Q is the flow rate used in the calibration run and measurement run). Preferably, the device 10 is further used with a fluid system to optimize a fluid path wash cycle. Using the configuration of components in FIG. 4 , the fluid path to be washed 62 extends from fluid path section 84 to the fluid connection means 40 ″ that connects the controllable pressure source 30 ″, wherein here, the controllable pressure source 30 ″ is a first wash syringe containing a first wash fluid. The control means 14 executes a series of instructions that cause the control means 14 to send connect command signals 52 , 52 ′, 52 ″ to fluid connection means 40 , 40 ′, 40 ″ to interconnect the fluid path 62 as illustrated for flushing. The control means 14 may send disconnect command signals 54 to other fluid connections means (not shown) to eliminate fluid path sections that are not be washed. The control means 14 , having already determined the viscosity of the wash fluid, sets a first wash pressure. It then sends a first pressure command signal 38 ″ to the first wash syringe 30 ″ to push wash fluid into the fluid path 62 . The control means 14 monitors the measured pressure in fluid path section 60 , and increases the source pressure, until the measured pressure equals the first wash pressure. This pressure assures that the wash fluid is flowing at the correct rate and assures that the predetermined volume of first wash fluid is delivered in a timely manner. For systems that require two levels of washing, a second controllable pressure source (not shown) functioning as a second wash syringe is filled with a second wash fluid and connected to port 43 ″. The first connection means 40 ″ selects between the first and second wash syringes. After washing with the first fluid, the control means 14 uses the first connection means 40 ″ to select the second wash syringe and sends a second pressure command signal to the second wash syringe until the measured pressure equals a predetermined second wash pressure. The control means 14 causes the second wash fluid to flow at the second wash pressure until a predetermined volume of second wash fluid has been provided. The device is used in a method of monitoring pressure in a fluid system. In FIG. 2 , the fluid system 24 is comprised of at least one fluid path section 32 having a first end 36 and a second end 34 and at least one controllable pressure source 30 connected to the first end 36 of the at least one fluid path section 32 . Although FIG. 2 , does not illustrate this, the connection between the at least one fluid path section 32 and the at least one controllable pressure source 30 may be through further components of the fluid system 24 . Each controllable pressure source 30 is responsive to a pressure command signal 38 to create a source pressure in the at least one fluid path section 32 . The fluid system 24 is connected so that it forms a fluid path filled with a fluid 16 . The method comprises providing a device 10 comprising a pressure monitor 12 for placement in communication with the fluid 16 in a first path section 32 and a control means 14 . The pressure monitor 12 generates a signal representative 20 of a measured pressure that is received by the control means 14 . The control means 14 sends signals 22 to the fluid system 24 . The pressure monitor 12 is placed in communication with the fluid 16 in the fluid path 32 . The control means 14 issues a pressure command signal 38 to the controllable pressure source 30 to cause it to generate the source pressure in one fluid path section 32 . The control means 14 compares the measured pressure to the source pressure, and generates an error message if the difference between the measured pressure and the source pressure exceeds a predetermined value. Preferably, the method determines whether a pressurized system is established within a specified time after a source pressure is applied. The fluid system 24 further comprises at least one fluid connection means 40 having a plurality of ports 42 , 44 , 46 , 48 for interconnecting with the at least one controllable pressure source 30 and the at least one fluid path section 32 . The fluid connection means 40 is capable of assuming at least a first position wherein fluid flows between at least two of the plurality of ports in response to a connect command signal 52 and a second position in which no fluid flows in response to a disconnect command signal 54 . A preferred fluid connection means is a multiport valve. A preferred system, as shown in FIG. 5A , comprises a first fluid connection means 140 having at least a first port 144 and a second port 142 , a second fluid connection means 140 ′ having at least a first port 144 ′ and a second port 142 ′, a first fluid path section 132 and a controllable pressure source 130 . The controllable pressure source 130 is connected to the first port 144 of the first fluid connection means 140 and the second port 142 of the first fluid connection means 140 is connected to a first end 134 of the first fluid path section 132 . The second end 136 of the first fluid path section 132 is connected to the first port 144 ′ of the second connection means 140 ′. The method further comprises sending at least one connect command signal 152 to the first fluid connection means 140 to place the first connection means 140 in the first, open position wherein fluid can flow between the first and second ports 144 , 142 . And sending at least one disconnect command signal 154 ′ to the second fluid connection means 140 ′ to place the second fluid connection means 140 ′ in the second, closed, position. This arrangement of the fluid connection means 140 , 140 ′ creates a closed system that, in the absence of leaks, should maintain an applied pressure. The control means 14 sends a pressure command signal 138 to the controllable pressure source 130 to generate a predetermined source pressure. The control means 14 compares the measured pressure to the predetermined source pressure and reports an establishment error if the difference is greater than a first allowed amount. If no establishment error occurs, the method preferably further waits a predetermined length of time and compares the current measured pressure to the predetermined source pressure again. If the decay in pressure is greater than a second allowed amount, a leak error is reported. Further, as fluid systems with more components and potential paths are monitored, the method above is preferably extended to provide the control means 14 with a library of entries comprising sets of command signals, times and sets of normal pressure values. Each set of commands is sufficient to configure the fluid system. The times are for specifying the interval between sending the set of commands and comparing pressures. The control means 14 selects one entry, issues the command signals for that entry and compares the measured pressures to the normal pressure values after the time interval. The control means 14 reports significant differences. Preferably, the method has the control means 14 issue connect 152 , disconnect 154 and pressure command 138 signals to the fluid system and identify degradations in the measured pressure indicative of reduced fluid integrity. In particular, after testing the fluid system as depicted in FIG. 5A , the method is preferably applied to a fluid system, shown in FIG. 5B , that is a variation on the tested system. The system comprises a first fluid path section 132 connected between a second port 144 of a first fluid connection means and a first port 142 of a second fluid connection 140 ′ means. The device 10 for monitoring measured pressure measures at the first fluid path 132 . A first controllable pressure source 130 ′ is connected to the second port 142 ′ of the second fluid connection means 140 ′. The sequence of steps in the method comprise sending disconnect command signals 154 from the control means 14 to the first fluid connection means 140 to cause it to assume the second position and connect command signals 152 to the second fluid connection means 140 ′ to assume a first position in which fluid flows between the first fluid path 132 and the first controllable pressure source 130 ′. The control means 14 then sends a pressure command signal 138 ′ to set the source pressure. Finally, the control means monitors the signal from the pressure monitor and identifies non-leaking components based on a stability of the measured pressure over time. If the second method indicates a leaking component, while the first method did not, the control means 14 can suggest that the components common to the two methods (port 142 of the first fluid connection means 140 , the fluid path section 132 and port 144 ′ of the second fluid connect ion means) are non-leaking. The method is adaptable to other configurations. For instance, when a second controllable pressure source (not shown) is connected to the second port of the second fluid connection means, the method has further steps. The control means sends at least one connect command signal and disconnect command signal to the first and second fluid connection means to place the first fluid connection means 140 in the second position and the second fluid connection 140 ′ means in an alternate first position. Now, fluid flows between the first fluid path 132 and the second controllable pressure source (not shown). The control means sends at least one pressure command signal to the second controllable pressure source to set the source pressure. The control means monitors the signal from the pressure monitor and identifies additional non-leaking components based on the stability of the measured pressure over time. When further controllable pressure sources are connected to a further ports of the first and second fluid connection means 140 , 140 ′, the method is extended similarly to identify further non-leaking components. Preferably, the first fluid connection means comprises an interconnection of more than one fluid connection means and the second fluid connection means comprises an interconnection of more than one fluid connection means. The method is applicable and provides additional information when the controllable pressure source providing pressure is located at a different fluid connection point in the fluid circuit. In particular, when an additional controllable pressure source is connected to a previously unused port of a fluid connection means, the control means connects the fluid circuit by sending connection command signals to the that fluid connection means to assume a first position in which fluid flows between the monitored fluid path and the additional controllable pressure source. In addition, the control means sends disconnect command signals to some fluid connection means to assume a second position blocking the fluid path. Then the control means sends a pressure command signal to the additional controllable pressure source to pressurize the fluid path. By monitoring the signal from the pressure monitor, the control means identifies additional non-leaking components based on the stability of the measured pressure over time. EXAMPLE A sample injector for a liquid chromatography system is illustrated in FIG. 6A . It comprises an injection mechanism comprised of a needle assembly 278 connected to a multiport valve and a metering syringe 210 and a wash mechanism comprising a pair of wash syringes 246 , 264 , a washing manifold and switching mechanisms 240 , 234 , 256 , 226 , and 208 to wash the fluid path between injections. A pressure monitor 212 that feeds readings to a control means (not shown) monitors the pressure between the metering syringe 210 and the multiport valve 200 . In testing the system to identify possible sources source of leaks, a sequence of four tests are performed. FIG. 6A illustrates the first test. Fluid path 201 , from the metering syringe 210 , through valve means 208 along fluid path section 204 , to multiport valve 200 , that is in the disconnect state, is pressurized by the metering syringe. Because multiport valve 200 is in the disconnect state, the fluid path 201 s closed and should hold a pressure. If the fluid path 201 does not maintain pressure the failure is likely one of: the metering syringe, pathway 203 through the valve 208 between the metering syringe 210 and the fluid path 204 , the fitting 206 at the interconnection of valve 208 and fluid path 204 , the fluid path 204 , the fittings 202 between the fluid path 204 or the multiport valve 200 in a disconnect state. If the fluid path 201 maintains pressure, the above components are likely sealing well and can be used as a basis for further tests. FIG. 6B illustrates a second test path 225 utilizing one of the wash syringes 246 to establish the pressure. This path uses the multiport valve 200 in the disconnect state, fluid path 204 and the fittings above as the known part of the fluid path. The switching mechanisms (valve means) 240 , 234 , 224 and 208 , fluid paths 235 , 230 , 22 , and the wash syringe 246 comprise the newly tested parts of the fluid path 225 . If this test reveals a leak, the likely leaking components or joints are along fluid path 225 after the fitting at junction 206 between the fluid path 204 and the valve 208 . FIGS. 6C and 6D illustrate two further tests that are performed on the system illustrated as part of the test sequence. Each of these tests incorporates further components in the fluid path. The test illustrated in FIG. 6C adds the untested components and connections between switching mechanism 226 port 224 and the second washing syringe 264 . In the test illustrated in FIG. 6D , the needle assembly 278 is inserted in a wash block manifold 276 to allow the fluid path 275 to pass through the needle assembly 278 . This test requires that valve means 208 at the end of the measured fluid path section 204 seal the fluid path 275 when in the disconnect position. Further, the valve means 200 is utilized in one of the open positions, with fluid flowing between the ports as shown by connection 286 . A further test, would change the position of the injection valve means 200 , so that the seal on the sample loop 294 and the internal paths 290 , 292 to the sample loop 294 were test. The results of the four tests illustrated in FIGS. 6A-6D are summarized in FIG. 6E , where most likely failure points are highlighted. A similar sequence of tests can be constructed for a known fluid system to minimize the uncertainty of leakage sources. The numerous teachings of the present application will be described with particular reference to the presently preferred embodiments. However, it should be understood that these embodiments provide only a few examples of the advantageous uses of the teachings herein. In general, statements made in the specification of the present application do not necessarily delimit any of the various claimed inventions. It will be obvious to those skilled in the art that various modifications can be made without departing from the spirit and scope of this invention.

A device comprising a pressure monitor and a control means that receives a signal representing measured pressure at the pressure monitor and controls the controllable elements of a fluid system is utilized to monitor a fluid system for error conditions, to optimize operations and to diagnose the fluid system. By following a testing protocol that selectively enables parts of the system, the control means narrows the list of possible failing components. Comparing the measured pressure against normal pressures allows the device to identify error conditions. Determining the volume of fluid being transported and controlling the duration of the flow optimizes operation of the fluid system.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation application of co-pending application Ser. No. 11/817,651, which is a national stage of and claims the benefit of priority of International Patent Application No. PCT/EP2006/010985, filed on Nov. 16, 2006, which claims priority to European Patent Application No. 05028290.4, filed Dec. 23, 2005, and European Patent Application No. 06010835.4, filed May 26, 2006, all of which are relied on and incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] The invention concerns a bone plate. [0003] Bone plates are known, for example, from CH 462375, WO 2000/53111, WO 2001/54601 or EP 0760632 B1. [0004] The configuration of the holes in this prior art is such that they consist of a combination of two intersecting holes with different diameters and are combined into a continuous hole, and each side of the continuous hole with its fixed diameter has its own functionality and also needs to be considered separate from each other. [0005] Thus, for example, it is not possible to use a standard cortical screw at the thread side of the continuous hole, but instead only a screw with headed thread. [0006] The other side of the continuous hole, not having a threaded part, is only suitable for insertion of a standard cortical screw, which can also be applied with compression and angle variability. [0007] Thus, one could also separate the holes entirely from each other, since they have no functional interfaces. [0008] This drawback then runs as well throughout the entire application, for when inserting a standard cortical screw one must also make sure that it is located on the proper side of the continuous hole. [0009] From U.S. 2004/0087951 there is known a bone screw having a threaded segment and smooth-wall segments arranged one on top of the other on its screw head, looking in the direction of the longitudinal axis of the screw. These smooth-wall segments serve for a flexible receiving of the screw in corresponding guideways. BRIEF SUMMARY OF THE INVENTION [0010] Based on the above, the problem of the invention is to improve the usage possibilities of a bone plate and enhance its flexibility of manipulation. [0011] This problem is solved by one embodiment of a bone plate comprising a bottom side that is to rest against the bone and an upper side opposite to the bone as well as a plurality of holes located preferably along the longitudinal axis of the plate, through which bone screws can be inserted to be anchored to a bone, wherein at least one of these holes is a continuous oblong hole comprising a longitudinal axis running in the direction of the longitudinal axis of the plate, wherein thread flights are provided in a partial area of the lateral side of the oblong hole, said thread flights, when seen in a direction transversal to the plane of the upper side, are arranged only over a part of the depth of the oblong hole, characterized in that, in the direction transversal to the plane of the upper side, above and/or below the thread flights, a support structure with smooth walls for the positive fit with a correspondingly configured negative structure at a screw head or screw neck of a bone screw is provided. Advantageous modifications are indicated in further embodiments. Finally, in another embodiment, a system is indicated, comprising of a bone plate according to the invention and at least one bone screw suitable for it, which can be regarded as a fixation system on the whole. [0012] The essence of the invention for the new bone plate is that both a thread and a smooth-wall support structure are arranged in a partial segment, uniformly one on top of the other, looking in a direction transverse to the plane of its upper side. Thanks to the interplay of thread and smooth-wall support structure, a bone screw with correspondingly configured negative structures can be held in the bone plate especially effectively, locked in position and protected against tilting. Thanks to the interplay of the thread in the oblong hole with a correspondingly fashioned counterthread on the head or neck of the bone screw, the bone screw is pressed firmly into the support structure with a negative structure or bearing structure corresponding in shape to the support structure and thus fixed securely. [0013] In one preferred embodiment, the thread flights in the bone plate of the invention extend along a shorter segment of the oblong hole than the smooth-wall support structure. This technical measure allows in practical use an easy and secure sliding of a bone screw provided with a thread at its neck and/or head and with the negative structure into the structures (thread, support structure) arranged at the oblong hole with a continuous movement of the bone screw along the oblong hole. A sliding transition to a smooth-wall support structure is easier to realize than a sideways sliding into a thread. Thus, the guiding for a secure and accurate transition of the thread at the head and/or neck of the bone screw can be accomplished by the initially occurring interaction between support structure and negative structure, dictating the direction. [0014] Preferred angle ranges for the wrap of the thread arranged on the head and/or neck of the bone screw and engaging with the thread of the oblong hole are 60°≦α≦190°, preferably 60°≦α≦180°, and for the corresponding wrap of the negative structure, 185°≦β≦300°. These values were best suited in tests for a preferably continuous movement of the screw along the oblong hole, while still ensuring firm support for a bone screw secured in the thread/support structure of the oblong hole. A free mobility of a bone screw along the longitudinal axis of the oblong hole makes it possible to use this both to apply a pressing force directed onto the point of fracture and to lock the plate angle-fixed. [0015] Especially in a preferred modification the thread looking in the plane of the upper surface engages at most 180 degrees of a circular circumference of a screw head or neck of a bone screw, to be brought into engagement with the latter. This configuration has the effect that a bone screw can move freely along the longitudinal axis of the oblong hole, and thus it can be used both to apply a pressing force directed onto the point of fracture and to lock the plate angle-fixed. [0016] At present, a conical surface is preferred as the support structure. In such a structure, a correspondingly conically shaped surface (negative structure) of the head or neck of the bone screw can be secured. In theory, it is also possible to use other shapes for the surfaces of the support structures, for example, hemispherical surfaces. [0017] It basically makes no difference to the bone plate of the invention whether the supporting structure is arranged first, seen from the upper side of the plate, and the thread is arranged in the lower region of the bone plate, or vice versa. One just as well have several thread segments in the bone plate, each of them alternating with and interrupted by at least one segment with a support structure. Preferred is a sample embodiment in which the threaded segment lies near the upper side of the bone plate and a support structure lies near the lower side of the bone plate. [0018] A recess in the transitional region between thread and support structure facilitates the passage of the screw head or neck, more precisely, the region provided with the thread, into the segment of the oblong hole provided with the thread, especially when pushing the bone screw along the oblong hole. [0019] In one embodiment, the oblong hole has a first guide structure at the upper side of the bone plate. This serves to guide the head or neck of a bone screw. This guide structure can be, for example, a circumferential margin with cross section in the form of a semicircle, in which a correspondingly spherical or hemispherical negative structure on the head or neck of a bone screw can slide. The guide structure defines a guideway. This guideway is a path, lying preferably in a plane, along which an imaginary point on the screw head slides when the screw is shoved along the guide structure. Moreover, this guideway is intersected by a longitudinal axis of the thread, which in the sense of the invention is the axis about which a counterthread rotates when being screwed into the thread, at an angle different from 90 degrees. This kind of tilting between thread and guide plane has the effect that, even for a maximum wrap of 180 degrees situated in the plane of the surface, the thread or the support structure provides a rather firm support to the screw head or neck, since the tilting leads to an effectively greater wrap, at least in a partial region of the thread. This effect is achieved by a “clamping” or “wedging” effect, produced by the tilting. [0020] Furthermore, it is preferable that the guideway be inclined by an angle between 0 and 90 degrees relative to the plane of the plate. Here, moreover, an embodiment is preferred in which the thread and the support structure are arranged in a segment of the oblong hole in which the guide plane lies deepest, i.e., furthest away from the upper side of the bone plate. [0021] The segment of the oblong hole provided with thread and support structure, according to the invention, is limited to a partial segment of the oblong hole, which lies preferably on a narrow side of the oblong hole. [0022] Advantageously, the oblong hole of the invented bone plate has a second guide structure, besides the first guide structure described above, serving to guide bone screws with threadless head and neck (standard cortical screws). This separation of the guide structures allows for a more clean separation in the action of the two bone screws which can possibly be employed with the invented bone plate. [0023] By oblong hole in the sense of this invention is meant not only a hole pattern produced by displacing a circle along a linear axis, but basically any shape of an opening which is longer in a first dimensional direction than in a second dimensional direction. Thus, an oblong hole in the sense of the invention can also have a “triangularly tapering”, oval, or “keyhole-shaped” configuration. Preferably, this oblong hole is continuous, i.e., with no “barriers” protruding into the hole. [0024] Finally, the invention specifies a system comprising of a bone plate as described above and a bone screw. The bone screw of this system has, according to the invention, a screw head or screw neck, on which it has a thread structure and a bearing structure configured complementary to the support structure of the oblong hole, being arranged one on top of the other and matching up with the corresponding negative structures in the bone plate. [0025] The bone plate can be stable-angle fixed and tightened at the same time with a bone screw, configured specially with a thread and a negative structure on the screw head and/or neck. However, it should be emphasized here that the bone plate of the invention can also be fixed with standard bone screws or bone screws derived from such standard bone screws, in particular, ones having neither a thread nor a negative structure at their screw head or neck. [0026] The bone plate of the invention—also together with the invented bone screw—offers a great variety of possible applications, which makes it suited for the fixation of the most diverse fractures. [0027] For this, it is especially preferred that all openings in the bone plate be configured as oblong holes with the properties of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0028] Additional benefits and features of the invention will emerge from the following description of a sample embodiment by means of the enclosed drawings. These show: [0029] FIG. 1 , a first sample embodiment of the invented bone plate in a three-dimensional view, [0030] FIG. 2 , the bone plate of FIG. 1 in a view from above, [0031] FIG. 3 , the bottom side of the bone plate from FIG. 1 , in an enlarged cutout, [0032] FIG. 4 , the bottom side of an alternative embodiment of the invented bone plate, in an enlarged view, [0033] FIG. 5 , a cross section through a bone plate from FIG. 1 along its central longitudinal plane, [0034] FIG. 6 , a cross section according to FIG. 5 , in enlarged view, with only one oblong hole depicted, [0035] FIG. 7 , a view as in FIG. 6 with the course of the guide structure drawn for clarity, [0036] FIG. 8 , a sample embodiment of a bone plate according to the invention, in a top view, [0037] FIG. 9 , in an enlarged cutout, the top view of an oblong hole of a sample embodiment of the invented bone plate, [0038] FIG. 10 , in an enlarged view, a longitudinal section through the oblong hole of FIG. 2 , [0039] FIG. 11( a ) a front view of a bone screw with thread and negative structure formed on its screw head to interact with the thread and the support structure in the invented bone plate, and FIG. 11( b ) a front view of a standard bone screw, [0040] FIG. 12( a ) a front view, comparable to FIG. 4 , of a bone screw for interworking with the thread and the support structure in the invented bone plate and FIG. 12( b ) a front view of a standard bone screw in one possible position in the oblong hole for fixation of the bone plate, [0041] FIGS. 13( a ), ( b ) and ( c ) provide a sequence consisting of three individual views to illustrate the sliding of the bone screw, provided with thread and negative structure on its screw head, into the segment of the oblong hole with thread and support structure, [0042] FIGS. 14( a ) and 14 ( b ) illustrate a sequence in two individual views, similar to FIG. 6 , to illustrate the sliding of a standard bone screw into the segment of the oblong hole with thread and support structure, [0043] FIG. 15 , the firm seating of a bone screw provided with thread and negative structure in the thread and the support structure of the oblong hole in a section view transverse to the lengthwise dimension of the bone plate, [0044] FIG. 16( a ), FIG. 16( b ), and FIG. 16( c ) illustrate three different possible additional shapes of an oblong hole of an invented bone plate. [0045] FIG. 17 , a front view of the invented bone plate with drill jig sleeve mounted to drill a screw hole in a bone, and [0046] FIG. 18 , a front view similar to FIG. 14 , but with an alternative variant of a drill jig sleeve. [0047] The figures show schematically sample embodiments of a bone plate according to the invention and all of them are generally designated with 1 . The sample embodiments shown are in no way true to scale, but serve merely as a basic illustration. DETAILED DESCRIPTION OF THE INVENTION [0048] The invented bone plate 1 has an upper side and a lower side 3 , serving to bear against the bone being fixated. Continuous openings in the form of oblong holes 4 are introduced into the bone plate between upper side and lower side. The oblong holes 4 are continuous in these sample embodiments, i.e., configured without any projections or similar obstructions reaching into the interior. The invented bone plate 1 has eight oblong holes 4 overall in these sample embodiments, yet without being limited to this number. The oblong holes 4 are configured as narrowing toward one of the lengthwise sides in the preferred sample embodiments. However, as is shown for example in an alternative embodiment per FIG. 4 , they can also have a straight course and correspond to the shape produced by displacing a circle along a predetermined distance. Of course, all other conceivable shapes of oblong holes are also possible, as long as they are continuous in form, i.e., free of obstruction in their interior. Corresponding examples are presented in FIGS. 16 a ) to c ). [0049] At one end face of each oblong hole are formed a thread or thread flights 5 , as well as a support structure 6 . The thread 5 and the support structure 6 lie one above the other in a direction transversely to the plane of the plate, while in these sample embodiments the thread 5 is arrange on top (toward the upper side 2 of the bone plate 1 ) and the support structure 6 underneath (toward the lower side 3 of the bone plate 1 ). In the transitional region between thread 5 and support structure 6 , a recess 7 can be introduced (see FIG. 6 ). However, this recess is not absolutely essential, and it is not present in the variant embodiments shown in FIGS. 8 through 13 , for example. The support structure 6 is formed by a smooth-walled segment of the oblong hole, being hemispherical in the sample embodiment shown in FIGS. 1 to 7 , or conical in the sample embodiment shown in FIGS. 8 to 13 . [0050] As is especially evident in FIGS. 1 , 2 , 3 , 8 , 9 and 16 , the thread 5 and support structures 6 of the oblong holes 4 in the sample embodiments shown there are arranged at the narrow sides of the latter, usually at the tapered narrow sides, being oriented in the direction of the middle of the plate. The longer lengthwise axes of the oblong holes 4 run along a lengthwise axis of the plate. [0051] The oblong hole 4 contains a circumferential guide structure 8 at its opening facing the upper side 2 of the bone plate 1 . This is formed by a margin with semicircular cross section, which is introduced in the oblong hole 4 , for example, by a chip-removal machining step (such as milling). As an illustration of this, FIG. 7 shows a “bathtub” shaped trend of this margin, i.e., the guide structure 8 . One also notices here that the guide structure 8 is inclined at an angle δ to the course of the plane of the plate Eρ, dictated by the trend of the upper side 2 of the bone plate 1 . Likewise, the guideway or guide plane E L is also inclined relative to a lengthwise axis A G of the thread, and this by an angle 6 . [0052] In particular, it is evident from FIG. 9 that the thread flights 5 in the sample embodiments shown in FIGS. 8 to 10 and also 16 run in a shorter circumferential segment of the oblong hole 4 than the support structure 6 . While the former extend over an angle α of preferably between 60 and 190 degrees, the latter extends over an angle range β of preferably between 185 and 300 degrees. This choice of different wrap regions allows for a smooth sliding of the bone screw into this region with a reliable fixation at the end, as shall be further explained below. [0053] FIGS. 11 a ) and 11 b ) show a bone screw 11 with a screw head 12 specially designed for interworking with the invented bone plate 1 and a standard bone screw 9 with a screw head 10 shaped smooth and spherical at the bottom side. The screw head 12 contains at an upper segment a thread 13 which is spherically configured in this sample embodiment and, underneath this, looking in the direction of the lengthwise axis of the screw, a segment with a bearing or negative structure 14 . This bearing structure 14 is smooth walled in this sample embodiment with partly spherical or conical trend, tapering in the direction of the screw tip and matched to the support structure 6 of the particular sample embodiment, and it is complementary to the shape of the support structure 6 of the bone plate 1 . [0054] The oblong hole 4 in the sample embodiment shown in FIGS. 8 to 10 contains two guide structures 8 and 8 a at its opening facing the upper side 2 of the bone plate 1 . While the first guide structure 8 is a guide structure for the guiding of a bone screw 11 with thread 13 and bearing structure 14 at the screw head 12 , the guide structure 8 a serves to guide the screw head 10 of a standard bone screw 9 . The two guide structures 8 , 8 a are arranged one on top of the other, formed by a margin with semicircular cross section, which is made in the oblong hole 4 , for example, by a chip-removal machining step (such as milling). The two guide structures 8 , 8 a each define a guideway, running at an inclination to the surface of the bone plate 1 . In particular, the first guide structure 8 (or the guideway defined by it), as in the previously described sample embodiment, intersects the plane of the plate, determined by the trend of the upper side 2 of the bone plate 1 , at a first angle other than 0 and 90 degrees. Likewise, the guideway is also inclined relative to a lengthwise axis of the thread, and this likewise at an angle other than 0 and 90 degrees. [0055] FIGS. 12 a ) to 14 show the interworking between a bone screw 9 of the traditional kind and a bone screw 11 of the adapted kind in the invention and the bone plate 1 of the invention. Thus, the functioning of the bone plate 1 of the invention and its elements shall now also be explained by means of these figures. [0056] FIG. 12 b ) and 14 show a traditional bone screw 9 inserted into the oblong hole 4 of the bone plate 1 , in two different positions. This bone screw 9 lies with the smooth, spherically formed underside of the screw head 10 against the complementary formed guide structure 8 (in the first sample embodiment) or 8 a (in the second sample embodiment) of the oblong hole 4 and can thus be shoved along the lengthwise axis of the oblong hole 4 , following the guideway dictated by this guide structure. Due to the slanted position of the guideway, a compression effect is achieved when screwing in the bone screw 9 , such that the bone plate 1 is pressed in a direction or a bone being fixed therewith is pulled in the other direction. In particular, the outer contour of the thread segment formed by the thread flights 5 in the oblong hole 4 is formed such that it also forms a guide surface shaped complementary to the conically shaped underside of the screw head 10 . This outer contour thus forms part of the guide structure 8 and 8 a. At this guide surface, the traditional bone screw 9 can become tilted relative to the vertical (corresponding to the direction of the thread axis). This gives a multitude of possibilities for securing the bone screw 9 in the bone. This tilting is possible not only in a direction along the lengthwise axis of the oblong hole, but also in directions transverse to it, so that ultimately one has a region of basically 360 degrees in which the screw can be tilted relative to the thread axis. [0057] Such a traditional bone screw 9 can be used with the bone plate 1 of the invention to achieve a compression effect. However, this bone screw is not suitable to achieving an angle-stable securing in bone plate 1 and bone. For this, one can use the bone screw 11 adapted to the bone plate according to the invention, as shall now be described with the help of FIGS. 12 a ) and 13 to 14 . [0058] The segment of the screw head 12 provided with the thread 13 has an outer contour (an envelope of the thread flights), which is likewise spherical and complementary to the contour of the guide structure 8 . In this way, the bone screw 11 can be led into the guide structure 8 . Thus, the bone screw 11 can also be used initially to accomplish a compression effect. But the peculiarity of the bone screw 11 is that it can be secured in stable position in the oblong hole 4 of the bone plate 1 . This situation is shown, e.g., in FIG. 5 a ). In this position, the thread 13 of the screw head 12 engages with the thread flights 5 in the oblong hole 4 , and the bearing structure (negative structure) 14 lies with positive fit against the support structure 6 . Thanks to the interworking of the thread flights 5 with the thread 13 , the bearing structure 14 is pressed firmly against the support structure 6 , while it should be noted that the support structure 6 and the thread flights 5 are coaxially configured, just like the thread 13 and the bearing structure 14 on the screw head 12 . The transition from the screw head 12 , more precisely, the thread 13 on the screw head 12 , to the thread flights 5 in the oblong hole 4 is facilitated and guided by the initially occurring contact between the negative structure 14 and the support structure 6 , which contact dictates a definitely guided movement. Thus, the start of the thread flight of the thread 13 can be taken securely into the thread flights 5 , so that the thread 13 ultimately engages with the thread flights 5 , without tilting. [0059] In a position as shown by FIG. 12 a ), the thread flights 5 enclose the screw head 12 and the thread 13 , looking in a plane of the surface 2 of the bone plate 1 , preferably by not more than 180 degrees. The screw 11 is held in its position by a clamping effect, achieved by the tilting of the guideway dictated by the guide structure 8 relative to the lengthwise axis of the thread, and by the interworking of the support structure 6 (continuing to enclose it in the second sample embodiment of the bone plate 1 ) with the negative structure 14 , while the negative structure 14 is pressed axially into the support structure 6 by the interworking of thread flights 5 and thread 13 . [0060] Only thanks to this fact is it possible to configure the oblong hole 4 as continuous and serviceably over its full length for either compression or for angle-stable fixation. [0061] FIGS. 17 and 18 show how the sleeves of drill jigs are connected to the bone plate for the operation to install the bone plate. The situation shown in FIG. 17 shows a simple drill sleeve 15 , which is screwed by a spherical thread 16 and bearing structure formed at its lower end (corresponding to the structures on the screw head 12 of the bone screw 11 ) into the thread 5 and the support structure 6 on the inside of the oblong hole 4 . The drill sleeve 15 affords a drilling channel 17 on its inside, which thanks to the proper fitting of the thread 16 and the bearing structure of the drilling sleeve 15 runs along the axis AG. The drilling sleeve 15 serves as an aid when drilling a hole in the bone being provided with the bone plate 1 to make sure that the drilled hole is perpendicular to the bone plate 1 and therefore a bone screw 11 can be screwed into the bone with stable angle, so that its screw head 12 with the thread 13 and the bearing structure 14 easily engages in the thread 5 and the support structure 15 . [0062] FIG. 18 shows a variant, in which an additional drilling sleeve 18 is placed onto a drilling sleeve 18 so that the drilling channel 19 of this drilling sleeve 18 lies exactly parallel to the axis A G . With this drilling sleeve 18 , one can drill screw holes in the bone, permitting the above-described dual function of a bone screw 11 . The bone screw 11 is screwed into the bone at such a perpendicular angle as allows it to slide initially along the inclined plane E L of the guide structure 8 for a compression and then to engage by the thread 13 and the bearing structure 14 on its screw head 12 securely and without tilting in the thread 5 and the support structure 6 on the inside of the oblong hole 4 , so as to become fixed in its angle at the end of the process. Thus, this enables a simultaneous compression and angle fixation in a single step with only a single screw. [0063] The drilling sleeves shown are purely for example, and there are various ways of achieving the same results with drilling sleeves of different design. [0064] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principals and applications of the present invention. Accordingly, while the invention has been described with reference to the structures and processes disclosed, it is not confined to the details set forth, but is intended to cover such modifications or changes as may fall within the scope of the following claims. LIST OF REFERENCE NUMBERS [0065] 1 bone plate [0066] 2 upper side [0067] 3 lower side [0068] 4 oblong hole [0069] 5 thread/thread flights [0070] 6 support structure [0071] 7 recess [0072] 8 guide structure [0073] 8 a guide structure [0074] 9 bone screw [0075] 10 screw head [0076] 11 bone screw [0077] 12 screw head [0078] 13 thread [0079] 14 negative structure/bearing structure [0080] 15 drill jig sleeve [0081] 16 thread [0082] 17 drill channel [0083] 18 drill jig sleeve [0084] 19 drill channel [0085] A G lengthwise axis of thread [0086] E L guide plane/guideway [0087] Eρ plane of the plate [0088] α angle [0089] β angle [0090] δ angle

The aim of the invention is to enlarge the possibilities of use of conventional bone plates and increase their flexibility of manipulation. To this end, the invention proposes a bone plate comprising a bottom side that is to rest against the bone and an upper side opposite to the bone as well as a plurality of holes located preferably along the longitudinal axis of the plate, through which bone screws can be inserted to be anchored to a bone. At least one of these holes is a continuous oblong hole comprising a longitudinal axis running in the direction of the longitudinal axis of the plate. A retaining structure, such as thread flights, is provided in a partial area of the lateral side of the oblong hole, said thread flights, when see in a direction transversal to the plane of the upper side, are arranged only over a part of the depth of the oblong hole. In the direction transversal to the plane of the upper side, above and/or below the thread flights, a support structure with smooth walls for the positive fit with a correspondingly configured negative structure at a screw head or screw neck of a bone screw is provided.

PRIORITY CLAIM [0001] This application is a continuation of PCT patent application No. PCT/DE2004/002022, filed Sep. 10, 2004, which claims the benefit of priority to German Patent Application No. DE 10344567.6, filed Sep. 25, 2003, both of which are incorporated herein by reference. TECHNICAL FIELD [0002] The invention relates to an immersion lithography method and a device for the exposure of a substrate. BACKGROUND [0003] In the production of large scale integrated semiconductor chips, ever more stringent requirements made of the fabrication installations and production processes used for the production of the semiconductor chips occur in particular by virtue of the ever advancing miniaturization of the structures on the semiconductor chip. One problem which occurs with the rising miniaturization of the large scale integrated semiconductor chips is the limitation of the miniaturization by the resolution capability of the lithography technology used which is employed for patterning the semiconductor chips of a wafer. [0004] As an introduction, a lithography device 600 that can be used for patterning a wafer 601 is illustrated schematically in a simplified manner in FIG. FIG. 6 . The lithography device 600 has an illumination unit 602 and a lens 603 . The wafer 601 is patterned by being exposed using a mask 604 or reticle. For this purpose, a structure formed on the mask is imaged by means of laser light 605 and the illumination unit through the lens 603 onto the wafer 601 , that is to say that the wafer 601 is exposed and a patterning of the wafer is thus possible. [0005] Various methods for carrying out the lithography are known in the prior art. One is the use of a so-called “stepper”. When using such a stepper, an entire mask used is transferred all at once within a single exposure step onto a first exposure field of the wafer. Afterward, the wafer is moved on and the next exposure field of the wafer is exposed. [0006] Another method which is used in lithography is one which is carried out by means of a so-called “scanner”. In the case of a scanner, the entire structure of a mask is not imaged onto a first exposure field of the wafer in one step, rather only a narrow strip of the mask is ever imaged all at once onto an exposure field of the wafer. For this purpose, a so-called exposure slot is used, which only ever illuminates a narrow strip of the mask and through which the mask is moved. During the exposure of an exposure field, the entire field gradually moves through the exposure slot. The mask is clearly scanned by means of this exposure slot. During the imaging of the mask onto a field of the wafer, both the mask and the wafer are moved. In this case, the movement of the wafer and of the mask generally takes place in opposite directions. To put it clearly, the mask is scanned by means of the exposure slot. In this case, every point on the mask is exposed during the movement through the movement slot with a plurality of laser flashes (pulses) onto the wafer. [0007] The resolution of a lithography technology is given by equation (1): R = k 1 · λ n · sin ⁡ ( θ ) [0008] where: R is the resolution, [0009] k 1 is a process-dependent factor, [0010] λ is the vacuum wavelength of the beam used for the lithography, and [0011] n·sin(θ) is the so-called numerical aperture, where n is the refractive index of the medium in which the lithography is carried out, and θ is the aperture angle of the lens. [0012] The process-dependent factor k 1 has a value of greater than 0.25 for physical reasons. Clearly, k 1 is greater than 0.25 in order to ensure that a uniform pattern of lines and interspaces, that is to say an alternation of bright and dark, can be imaged and is still discernible as such a pattern. In lithography, the wavelength is currently still limited to wavelengths of more than approximately 150 nm, since no materials which are transparent to light having a shorter wavelength are known to date. [0013] It emerges from these boundary conditions that in order to increase the resolution capability, which increase is necessary for a lithography for the patterning of small structures, it is scarcely possible to make a change to k 1 or to λ. Consequently, the only factor that remains is n·sin(θ), the so-called numerical aperture of the device, which is also designated as NA. In this case, it must be taken into consideration that sin(θ)≦1 holds true for mathematical reasons. Clearly, θ specifies the aperture angle at which light can enter into an imaging element (lens) in order that it also leaves the imaging element again without being subjected to total reflection, and is therefore a measure of the light intensity entering into the imaging element and the resolution capability of the lithography device. [0014] Lithographic methods in semiconductor production have usually been carried out by means of air as the immersion medium, that is to say as the medium situated between the imaging element and the substrate. A refractive index of n≈1 thus results. If the lithographic method is carried out with a medium different than air, that is to say if a so-called immersion lithography is carried out, then the resolution capability can be improved by a factor which is equal to the refractive index of the immersion medium. In the case of such an immersion method, a liquid having a refractive index of n>1 is introduced into an interspace between an imaging element, that is to say e.g. a lens, and a lithography device. [0015] The use of an immersion medium makes it possible to have the effect that additional light contributes to the light intensity of the imaging element. Light which is incident in the imaging element at an angle which is too large to still contribute to the light intensity of the imaging element given an immersion medium of air, that is to say would be subjected to total reflection, can still contribute to the light intensity given the use of an immersion medium with a higher refractive index than n=1. As a result of this, it is possible to obtain a better resolution, or the depth of focus of the imaging can be increased for the same resolution. [0016] One disadvantage of immersion lithography, however, is that the immersion medium absorbs part of the light which is used for the exposure of the wafer. The immersion medium is heated as a result of the absorption. The heating of the immersion medium in turn leads to a change in the refractive index of the immersion medium. For water, there are estimations for the change in the refractive index with the temperature T which amount to approximately dn/dT=10 −4 K −1 for a wavelength of λ=193 nm. [0017] This in turn leads to a slight change in the distance between the imaging element and the wafer, at which distance the best focusing can be obtained, that is to say that the imaging is sharpest or, to put it another way, the resolution takes up the smallest value. The change in the temperature and hence in the refractive index of the liquid also leads to a reduction of the depth of focus (DoF) of the imaging. In a lithography method, the depth of focus of the projected image, that is to say the image of the mask, is thereby reduced, thus resulting in a reduction of a processing window for the lithography method, that is to say which fluctuation range the lithography parameters are permitted to have. [0018] One approach to solving this problem lies in controlling the temperature of the immersion liquid. That is to say that it is attempted to keep the temperature as far as possible constant and to stabilize it within a small temperature interval. However, this has to be effected very exactly. Such exact temperature control is costly and can only be achieved with difficulty. Focal changes that remain furthermore have an adverse influence on the depth of focus of the imaging and on the resolution of the lithography method. [0019] In order approximately to specify the order of magnitude of how exactly the temperature is to be complied with and how great the influence is of a change in temperature that remains, this will be estimated on the basis of an example. For a wavelength of λ=193 nm, a refractive index of n=1.47 (deionized water), a sin(θ)=0.75 and a working distance, that is to say a distance between the imaging element and the wafer surface to be patterned, of D=1 mm, δn<6·10 −7 has to be complied with if a change in the distance of sharp imaging of ΔD<1 nm is intended to be complied with, where δn is the change in the refractive index. From δn<6·10 −7 and the estimation of dn/dT=10 −4 K −1 already discussed above, it is possible to calculate on the basis of equation (2) Δ ⁢   ⁢ D = D · δ ⁢   ⁢ n n · cos 2 ⁢ θ [0020] how exactly the temperature must be controlled and regulated. A required accuracy of 6 mK results. This accuracy of the temperature control can be complied with only with difficulty, as a result of which the use of immersion lithography in the patterning of semiconductor elements is greatly impeded and made greatly difficult. [0021] U.S. Pat. No. 6,191,429 to Suwa discloses a focusing device which has an objective system for optically producing a workpiece, for forming a desired pattern on a surface of a workpiece or for inspecting a pattern on a workpiece, and which is used to set the focus state between the surface of the workpiece and the objective system. [0022] U.S. Pat. No. 6,586,160 to Ho, et al. discloses a scanning exposure system which provides light which comprises items of pattern information which are intended to be transferred onto a wafer, and thus patterns a photoresist layer on the semiconductor wafer. [0023] Japanese Patent No. JP10303114 discloses an immersion lithography device, a working distance between the device and a workpiece satisfying a relation which takes account of the temperature coefficient of the refractive index of the immersion fluid and the temperature. [0024] U.S. Pat. No.6,509,952 to Govil, et al. discloses that linewidth control parameters vary within a pattern as a consequence of properties of a lithography device, and that these variations can be compensated for by means of linewidth offset coefficients. SUMMARY [0025] The invention is based on the problem of solving the abovementioned disadvantages of the prior art and of providing an immersion lithography method for the exposure of a substrate and a device for such a method which reduce the problem of the accurate temperature control during the immersion lithography. [0026] The problem is solved by means of an immersion lithography method for the exposure of a substrate and a device for carrying out such a method comprising the features in accordance with the independent patent claims. [0027] An immersion lithography method for the exposure of a substrate is carried out by means of a scanning exposure device having a beam source, which generates a beam, a holder, which accommodates a reticle, a carrier, on which a substrate is arranged, and an imaging element, which is arranged between the reticle and the substrate, in which case, during the exposure of the substrate, an immersion fluid is introduced between the imaging element and the substrate, and in which case, during the method, the beam passes from the radiation source through the reticle, through the imaging element and through the immersion fluid onto a substrate surface to be exposed, the beam scans the reticle in a first direction, the carrier is moved in a second direction during the exposure of the substrate and the depth of focus and/or resolution of the exposure, or, to put it another way, the position of best focus during the exposure, of the surface of the substrate is set by varying during the exposure with the reticle a distance in the beam direction between the reticle and the surface of the substrate along the direction of movement of the carrier. [0028] A device for carrying out an immersion lithography for the exposure of a substrate has a beam source for emitting a beam, a carrier, on which a substrate can be arranged, a holder for accommodating a reticle, and an imaging element, which is arranged between the holder and the carrier. In the device, the carrier and the holder are set up in such a way that they can be moved in relation to one another, and the arrangement is set up in such a way that an immersion fluid can be introduced between the imaging element and the carrier. Furthermore, the arrangement is set up in such a way that a reticle arranged in the holder and a surface to be exposed of a substrate arranged on the carrier are tilted in relation to one another during the exposure of the surface of the substrate. [0029] The invention can clearly be seen in the fact that a reduction of the depth of focus and/or an increase in the resolution which as a result of the heating of an immersion liquid, which heating is brought about by a beam, e.g. laser beam, and leads to a shift of the best focus position, is not prevented solely by a control of the temperature of the immersion liquid, but rather by means of a tilted arrangement of the reticle and the carrier, on which a substrate to be patterned is arranged, that is to say a substrate having a surface to be exposed. Clearly, the distance between the reticle and the substrate surface to be exposed increases or decreases in the direction of movement of the carrier. To put it another way, the reticle in the holder and the substrate surface to be exposed are not oriented parallel to one another, but rather are at a relative angle with respect to one another. The arrangement is configured such that it enables the change in the position of the best focus to be compensated for by means of the varying distance between the reticle and the substrate surface to be exposed which results from said relative angle. That is to say that the ΔD from equation (2) which results for a given rise in temperature is not prevented by controlling the temperature, but rather is compensated for by means of an additional ΔD which results from the relative angle between the reticle and the substrate surface to be exposed. [0030] To put it another way, the normal vector of the substrate surface to be exposed, which to a good approximation represents a plane area, and the normal vector of the reticle, which to a good approximation represents a plane area, are not oriented parallel or antiparallel, but rather are at the relative angle. The position of the best focus can be understood to be the position in which the depth of focus and/or resolution in the position is best, that is to say the depth of focus is greatest and/or the resolution is smallest. [0031] The arrangement according to the invention and the method according to the invention have the advantage that they make it significantly simpler to prevent the adverse influences of the heating of the immersion fluid on the depth of focus and/or resolution. The relative angle and thus the distance between the reticle and the substrate surface to be exposed can be measured and regulated significantly more easily than a temperature which, as described above, is to be regulated accurately to a few mK. [0032] The setting of the depth of focus and/or the resolution involves, in particular, keeping constant the depth of focus and/or resolution during the exposure of an individual electronic component to be patterned on the substrate. [0033] Preferred developments of the invention emerge from the dependent claims. In this case, preferred developments of the immersion lithography method for the exposure of a substrate also apply to the device, and vice versa. Preferably, the distance is varied in such a way that the change in depth of focus and/or resolution caused during the exposure by a change in temperature of the immersion fluid during the exposure is compensated for. [0034] In one development, the immersion fluid is a fluid having a high transparency at a given exposure wavelength and/or having a small dn/dT. [0035] A high transparency of the immersion fluid, e.g. a liquid, at the exposure wavelength used during the method leads to a low absorption during the exposure, thus to a lower input of energy into the immersion fluid and thus also to less heating. A small dn/dT in turn leads to an only small change in the refractive index for a given change in temperature and thus to an only small change in the position of the best focus. The transparency is preferably more than 0.9, particularly preferably more than 0.95. The dn/dT is preferably less than 10 −3 , particularly preferably less than approximately 10 −4 . [0036] The immersion fluid may be water or a perfluoropolyether. [0037] Water and perfluoropolyether have a high refractive index in conjunction with good transmission properties, that is to say good beam transmissivity. Consequently, it is possible to effectively prevent the total reflection when the beam emerges from the imaging element, and to increase the numerical aperture. This in turn leads to an improved resolution or to an improved depth of focus for the same resolution. The water used is preferably high-purity deionized water, because gases, such as oxygen for example, and solids, such as impurity atoms for example, dissolved in the water influence the optical properties of the water. In particular, it is possible to use water as the immersion medium at a wavelength of 193 nm used for the lithography, and to use perfluoropolyethers, such as, for example, that known by the trade name Krytox®, for the lithography at a wavelength of 157 nm. [0038] Preferably, the carrier is moved obliquely with respect to the reticle. That is to say that the carrier is not moved parallel to a main direction of the reticle, which to a good approximation represents a plane area, rather it is moved obliquely, that is to say at a relative angle with respect to the main direction of the reticle. The oblique movement of the carrier makes it possible to achieve in a simple manner the variation of the distance between the reticle and the substrate surface to be exposed, which substrate is arranged onto the carrier, along the direction of movement. As a result of this, a AD which is caused by the change in the refractive index of the immersion fluid as a result of the rise in temperature during the scanning of the reticle can be compensated for easily and the resolution of the exposure can be improved and/or the depth of focus of the exposure can be increased. [0039] Particularly preferably, the reticle is tilted relative to the substrate surface to be exposed. [0040] The tilting of the reticle relative to the substrate also makes it possible to achieve in a simple manner the variation of the distance between the reticle and the substrate surface to be exposed, which substrate is arranged onto the carrier, along the direction of movement. As a result of this, a ΔD which is caused by the change in the refractive index of the immersion fluid as a result of the rise in temperature during the scanning of the reticle can once again be compensated for easily and the resolution of the exposure can be improved and/or the depth of focus of the exposure can be increased. [0041] The tilting of the reticle is particularly advantageous since a demagnifying imaging element is usually used in a scanning exposure device. As a result of this, the structure used to expose the substrate can be represented in enlarged fashion on the reticle. Assuming that the structure on the reticle has an extent of 100 nm×100 nm in the X-Y plane of the reticle, then it is imaged onto an area in the X-Y plane of 25 nm×25 nm in the case of an imaging element which effects 4:1 demagnification. However, the imaging element acts not only in the X-Y plane but also in the Z direction, to be precise in such a way that a change in the z position of the reticle by 16 mm brings about a shift in the focus, that is to say the X-Y plane of the sharpest image downstream of the imaging element, by only 1 mm. This corresponds to a “stepping-down” of the shift in the z position. The distance between the reticle and the substrate can thereby be regulated in a simple manner since possible inaccuracies in the regulation of the tilting of the reticle are reduced by a factor of 16. [0042] In one development, the variation of the distance between the reticle and the substrate surface to be exposed proceeds linearly along the direction of movement of the carrier. [0043] To consider it clearly, this means that as the movement of the substrate increases within an exposure field, that is to say a field on the substrate which is exposed by means of a reticle and which represents an individual electronic component after the processing has ended, the variation of the distance between the substrate surface to be exposed has a linear portion, that is to say that the distance becomes linearly larger or smaller. A linear decrease in the distance is advantageous since it can easily be obtained. On the other hand, both the change in the refractive index as a function of the change in the temperature and the change in the z position of the focus as a function of the change in the refractive index are linear to a first approximation. That is to say that dn/dT ≈constant and dz/dn ≈constant. It is apparent from this that in the case of an exposure device which is not a stepper but rather has a scanning mode of operation, Δz, that is to say the change in the focus position in the z direction, is proportional to the exposure energy that a point to be exposed has already experienced, and thus also proportional to the position within an illumination slot with the aid of which the reticle is scanned, which in turn has the effect that for compensating for the focal change it is advantageous to linearly vary the distance between the reticle and the substrate surface to be exposed. [0044] The second direction may be opposite to the first direction. [0045] The temperature of the immersion fluid is preferably regulated. [0046] In the case of an additional temperature regulation of the immersion fluid, the temperature regulation can be used to carry out a coarse control of the depth of focus and/or the resolution of the exposure, while the fine control of the depth of focus and/or the resolution of the exposure is carried out by means of varying the distance between the reticle and the substrate surface to be exposed. That is to say that possible changes in the focus which occur as a result of inaccurate temperature regulation can be compensated for by means of the distance variation. [0047] The imaging element may be a lens or a lens system. [0048] In one development, the immersion fluid is introduced between the imaging element and the substrate during the exposure. [0049] This clearly means that the immersion fluid is injected, during the exposure of a substrate, for example into the interspace between the imaging element and the substrate. Injection represents a method that can be carried out in a simple manner for providing the immersion fluid. [0050] In one development, the distance variations are determined as offsets prior to the exposure of the substrate in a calibration step for the substrate and, during the exposure of the substrate, the offsets that have been determined and stored are used in order to carry out, that is to say set, the distance variations. [0051] In general, the substrate is calibrated prior to the exposure within a lithography in order to correctly orient it later for the exposure. Calibration values are obtained in this case. The offsets which are produced for the compensation for the variations of the best focus position as a result of the change in temperature of the immersion fluid can then be added to said calibration values. Said offsets can be determined by calculating them, for example, or else measuring them in the calibration measurement. The calculation is explained in more detail below. [0052] The calibration, the determination and addition of the offsets can also be carried out by the so-called “on-fly” method. For this purpose, a CCD camera that is generally present in a lithography device may be used for the calibration. In this case, “on-fly” means that the calibration is carried out directly before a directly subsequent exposure step, that is to say within a method that is not subject to any temporal interruption. [0053] To summarize, the invention can be seen in the fact that in an immersion lithography technology, it is not attempted to prevent the effects of a change in temperature of the immersion medium primarily by regulating the temperature, but rather to compensate for this by means of varying the distance between a reticle used and a substrate surface to be exposed. To put it clearly, a relative angle between the reticle used and the substrate to be exposed is set which has a magnitude such that, by means of this relative angle, the distance between the reticle and the substrate surface to be exposed changes during the exposure of the substrate, to be precise to the extent necessary to compensate for the change in the z position of the best focus, which change is caused by the change in temperature of the immersion medium. [0054] The relative angle must be calculated prior to the exposure in order to be able to take it into account during the exposure. In order to calculate it, it is necessary to determine the energy dose which the immersion medium takes up during the exposure, in order to determine therefrom the change in the z position of the best focus. This can be carried out during a calibration step which is already customary anyway and which is carried out for each exposure field of a substrate or per substrate once or at predetermined time intervals. Clearly, each exposure field of a substrate is scanned prior to the actual exposure by means of a calibration device in order to obtain the items of information required for the exposure. In this case, inter alia, a height profile of the substrate surface to be exposed is created in order to carry out an exact lithography. An offset is then also added to said height profile, said offset corresponding to the linearly increasing offset which is caused by the increase in temperature of the immersion medium. It should be taken into consideration that the offset does not have to be measured for every field, rather it generally suffices for the offset to be measured at predetermined time intervals. One criterion for the time intervals is, for example, that it is ensured that no alterations that affect the position of the best focus have arisen between two measurements. [0055] The effects of the change in temperature of the immersion medium primarily reside in the fact that the refractive index of the immersion medium changes. It follows from this that the z position, that is to say the distance at which a sharp image arises downstream of an imaging element, changes with the temperature of the immersion medium. The change in the z position of the focus in turn leads, if it is not compensated for, to a deterioration in the resolution and/or a smaller depth of focus during the exposure of the substrate. The change in the z position is approximately linear over the exposure slot and can therefore be compensated for by tilting the reticle and/or substrate. BRIEF DESCRIPTION OF THE DRAWING [0056] Exemplary embodiments of the invention are illustrated in the FIG.s and are explained in more detail below. [0057] FIG. FIG. 1 shows a schematic illustration of a scanning exposure device in accordance with one exemplary embodiment of the invention, [0058] FIG. FIG. 2 shows a schematic illustration illustrating the introduction of an immersion fluid, [0059] FIG. FIG. 3 shows a schematic illustration of the temperature of an immersion fluid during an exposure and the position of the focus in relation to the position within the exposure slot, [0060] FIG. FIG. 4 shows a schematic side view of a scanning exposure device in accordance with a first exemplary embodiment of the invention, [0061] FIG. FIG. 5 shows a schematic side view of a scanning exposure device in accordance with a second exemplary embodiment of the invention, and [0062] FIG. FIG. 6 shows a schematic simplified illustration of a lithography device in accordance with the prior art. DETAILED DESCRIPTION [0063] shows a schematic representation of a scanning exposure device 100 for an immersion lithography. The scanning illumination device is also called a “scanner exposure tool” or scanner for short. For the purpose of improved clarity, no immersion fluid is illustrated in FIG. FIG. 1 . [0064] A scanner 100 has a holder 101 , which accommodates a reticle 102 , an imaging element 103 , e.g. a lens or a lens system, and a carrier 104 , on which a substrate 105 is arranged. The reticle 102 is illuminated from above by a beam source (not illustrated), e.g. a laser, in FIG. FIG. 1 . The beam from the beam source passes through the reticle 102 and passes further downward in the direction of the substrate in FIG. 1 . A so-called exposure slot 106 has the effect that only a small region of the reticle 102 is exposed, that is to say only a small partial region of the reticle 102 is illuminated and the relevant beams can pass into the lens system 103 . The exposure slot 106 is indicated as a hatched region within the reticle 102 in FIG. 1 . Furthermore, in order to make it clear that only beams from a small partial region pass into the lens system 103 , this partial region is illustrated in bright fashion in FIG. 1 on the top side of the lens system 103 . The lens system 103 is formed in such a way that it generates a sharp image of structures that are present on the reticle 102 on the substrate 105 . The region of the substrate 105 which is currently being exposed is in turn illustrated as a bright strip in FIG. 1 . In general, the beam is emitted in pulsed fashion, so that a large number of short beam pulses are used to expose the substrate 105 . [0065] In order to image all the structures of the reticle 102 on the substrate 105 , the reticle 102 moves relative to the exposure slot 106 . In FIG. 1 , this movement and the direction thereof are indicated by a first arrow 107 toward the right. Through the movement of the reticle 102 relative to the stationary exposure slot 106 , the entire reticle is scanned by the beam from the beam source and imaged on the substrate 105 . In order to attain a sharp imaging on the substrate 105 , however, the substrate 105 must also be moved. In general, the movement of the substrate 105 will be opposite to the movement of the reticle 102 since a simple lens system generates an image which is inverted. In other words, in FIG. 1 , the carrier 104 , on which the substrate 105 is arranged, moves toward the left, which is indicated by a second arrow 108 . [0066] In the case of the movement of the reticle 102 and the carrier 104 , it must be taken into consideration that in general a lens system is used which does not image the structures arranged on the reticle 102 onto the substrate on a scale of 1:1. In FIG. 1 , the “4×” on the lens system schematically indicates that the structures are imaged onto the substrate on a scale of 4:1. In this case, the speeds of the movements of the reticle 102 and of the carrier 104 have to be adapted to the imaging scale. In general, a lens system which demagnifies the structures is used. If a lens system which demagnifies the structures e.g. by the factor four is used, then the speed at which the reticle is moved must be greater by the factor four than the speed at which the carrier 104 and hence the substrate 105 are moved. [0067] FIG. 2 then schematically shows how an immersion fluid can be introduced between the lens system 103 and the substrate 105 . [0068] FIG. 2 shows a side view of a detail from the arrangement for an immersion lithography method according to the invention. [0069] FIG. 2 illustrates the lens system 103 , the carrier 105 and the substrate 105 . The holder 101 , the reticle 102 and the exposure slot 107 are not illustrated in FIG. 2 for the sake of clarity. The movement of the carrier 104 is illustrated by the double arrow 209 . The latter is intended to indicate that the carrier 104 can move in two directions depending on how the reticle 102 (not illustrated) moves. In addition, FIG. 2 symbolically illustrates a supply line 210 , by means of which an immersion fluid 211 can be introduced between the lens system 103 and the substrate 106 . In the exemplary embodiment, the immersion fluid is high-purity water, that is to say water which is low in impurities such as, for example oxygen or impurities, or a perfluoropolyether, such as, for example, the perfluoropolyether known by the trade name Krytox®. [0070] FIG. 3 schematically shows the profile of the temperature of the immersion fluid and the z position of the focus, along the position of the exposure slot. [0071] In FIG. 3 a , the ordinate (Y axis) represents the temperature of the immersion fluid in arbitrary units and the abscissa (X axis) represents the x position on the substrate. FIG. 3 a clearly illustrates a snapshot of the temperature over the position on the substrate. In addition, the dashed lines 312 and 313 specify the region into which the exposure slot is imaged. The two dashed lines 312 and 313 clearly represent the first and second edge boundaries of the exposure slot. In FIG. 3 a , the substrate moves toward the right, which is indicated by the arrow 316 . The movement of the substrate toward the right has the consequence that the temperature of the immersion fluid continuously increases from the region of the substrate which, through the movement of the carrier, is currently penetrating into the region into which the exposure slot is imaged ( 312 ) to the region of the substrate which is currently leaving the region into which the exposure slot is imaged ( 313 ). This continuous increase in the temperature is associated with the fact that the immersion fluid, which is introduced into the interspace between the lens system and the substrate, practically adheres to the substrate surface and thus moves concomitantly with the substrate. Consequently, the immersion fluid, which, in FIG. 3 , at the dashed line 313 , is currently leaving the region into which the exposure slot is imaged, has been subjected longest to the exposure and has thus been subjected the most greatly to a temperature increase through the partial absorption of the laser beam. After the substrate has left the region into which the exposure slot is imaged, the temperature of the immersion fluid decreases again. [0072] In FIG. 3 b , the ordinate (Y axis) represents the z position of the best focus and the abscissa (X axis) represents the x position on the substrate. FIG. 3 b clearly illustrates a snapshot of the z position of the plane in which a sharp image is generated over the position on the substrate. In addition, the dashed lines 312 and 313 again specify the region into which the exposure slot is imaged. In FIG. 3 b , the substrate moves toward the right, which is indicated by the arrow 317 . This can be seen analogously to FIG. 3 a . The movement toward the right of the substrate has the consequence that, as shown in FIG. 3 a , the temperature, with the latter the refractive index and thus also the z position of the best focus illustrated in FIG. 3 b changes continuously in the region of the substrate which, through the movement of the carrier, is currently penetrating into the region into which the exposure slot is imaged ( 312 ) to the region of the substrate which is currently leaving the region into which the exposure slot is imaged ( 313 ). The z position of the best focus moves closer and closer to the lens system. This continuous variation of the z position is associated with the continuous rise in the temperature of the immersion fluid, since the refractive index is to a first approximation proportional to the temperature and the z position is in turn to a first approximation proportional to the refractive index. Consequently, the profile of the z position of the best focus illustrated in FIG. 3 b follows the profile of the temperature illustrated in FIG. 3 a. [0073] FIG. 4 illustrates a schematic side view of a scanning exposure device in accordance with a first exemplary embodiment of the invention. The scanning exposure device of FIG. 4 has a reticle 402 an imaging element 403 , which is schematically illustrated as an individual lens in FIG. 4 , and a carrier 404 , on which a substrate 405 is arranged. An immersion fluid, which is not illustrated in FIG. 4 for the sake of clarity, is introduced between the substrate 405 and the lens 403 during the exposure of the substrate. [0074] In the first exemplary embodiment, the distance between the reticle 402 and the surface to be exposed of the substrate 405 is varied in the direction of movement, or to put it another way during the movement, by means of the carrier 404 being moved obliquely with respect to the reticle 402 . The direction of movement of the reticle 402 is indicated by a first arrow 407 and is toward the left in FIG. 4 , while the direction of movement of the holder 404 and thus of the substrate 405 , which runs toward the right in FIG. 4 , is indicated by a second arrow 408 . [0075] In order to illustrate the invention, the obliquity of the movement of the carrier 404 relative to the orientation of the reticle 402 , that is to say the relative angle formed by the reticle 402 and the carrier 404 , has been represented in a greatly exaggerated manner in FIG. 4 . On a correct scale, the relative angle that would have to be set in order to compensate for the focus position change produced by the heating of the immersion fluid would not be discernible in the FIG. [0076] A brief explanation is given below of how it is possible to determine the size of the variation of the distance between the reticle and the substrate. [0077] In a conventional lithography exposure device, also called an “exposure tool”, a calibration is carried out prior to the actual exposure at each field of the substrate, a so-called exposure field, which contains individual electronic components after completed processing. Said calibration is generally necessary since, for a correct exposure, that is to say an exposure with a small resolution, the individual substrate has to be measured accurately, for example in terms of its height profile. The calibration measurement then yields, inter alia, a height profile of an individual exposure field within the substrate. An offset, which as a result of the z position shift of the best focus that follows from the change in temperature of the immersion fluid can then also simply be added to said height profile. The value of the offset rises, as illustrated in FIG. 3 b , to a first approximation, linearly in the region of the exposure field which is currently just being exposed through the exposure slot. The offset, which arises as a result of the change in temperature of the immersion fluid, can be determined in a manner corresponding to the calibration measurement and be stored. Two calibrations are preferably carried out, in which case, in a first calibration, each exposure field is measured prior to the exposure and, in a second calibration, the offset is measured once for a given installation. The offset can then be corrected as required, that is to say according to the conditions at the start of the exposure of each substrate or wafer, or hourly, daily or at other given time intervals. Once the offset has been stored, e.g. in the form of a table, a so-called “look-up table”, it can then be taken into account in a subsequent exposure of the exposure field by being added to the height profile of the exposure field. The storage may take place for example in a memory of a computer, which computer can also be used in carrying out and evaluating the calibration measurement and/or in determining the offset. The storage affords the advantage that the same offsets can be used repeatedly if identical exposures, that is to say an exposure process having identical parameters, such as, for example, exposure time, photoresist, reticle, etc., are carried out. This obviates new calculations and/or new measurements of the offsets. [0078] In order to determine the offset, it is necessary to determine the rise δT in temperature of the immersion fluid along the movement of the carrier. From this rise δT in temperature of the immersion fluid along the movement direction, it is possible to calculate the change in the refractive index δn given known dn/dT. To a first approximation, dn/dT can be assumed as a material constant of the immersion fluid for this purpose. δT can be determined by means of equation (3): δT=(1−τ)γ/cD [0079] Where: δT is the rise in temperature, [0080] τ is the transmission coefficient of the immersion fluid, [0081] γ is the energy dose required to expose the photoresist used during the exposure, [0082] c is the specific heat of the immersion fluid, and [0083] D is the distance between the imaging element and the substrate, that is to say the working distance. [0084] Consequently, for the defocusing, that is to say the shift in the z position of the best focus, as a result of the change in temperature of the immersion fluid, to a first approximation, this results in equation (2) already specified above Δ ⁢   ⁢ D = D · δ ⁢   ⁢ n n · cos 2 ⁢ θ [0085] From this it is then possible to calculate the required variation of the distance along the entire region on the substrate onto which the exposure slot is imaged, that is to say the region in FIG.s 3 a and 3 b between the lines 312 and 313 . For the linear approximation of the speed of the variation of the z position of the best focus, that is to say the necessary speed of the substrate in the direction of the z coordinate, equation (2), equation (3) and δ ⁢   ⁢ n = ⅆ n ⅆ T . δT give rise to the following equation (4) Δ ⁢   ⁢ D Δ ⁢   ⁢ t = ⅆ n ⅆ T · ( 1 - τ ) · γ c · n · cos 2 ⁢ θ · 1 Δ ⁢   ⁢ t [0086] where Δt is the time for which a point on the substrate is exposed, that is to say the time required by a point in order, once it has penetrated into the region of the exposure slot, to leave this region again, to put it another way the time required by a point on the substrate in order to cover the distance from the dashed line 312 as far as the dashed line 313 in FIGS. 3 a and 3 b. [0087] From equation (4) it is possible, as explained above, to calculate a speed in the z direction which the substrate surface to be exposed has in order to compensate for the change in the refractive index of the immersion fluid as a result of the increase in temperature of the immersion fluid during the exposure. In this case, the direction of the speed in the z direction depends on the sign of dn/dT; generally this is such that the distance between the substrate surface to be exposed and the imaging element decreases along the direction of movement in order to compensate for the changes caused by the temperature changes, as also emerges from FIG. 3 b. [0088] The speed in the z direction can also be converted in a simple manner into a relative angle which the substrate surface to be exposed must have with respect to the reticle. [0089] In addition to the above-described calculation of the shift in the best focus in the z direction, the shift in the best focus can also be determined experimentally. The experimental determination is simpler to carry out, under certain circumstances, than the analytical method described. By way of example, the parameters required for the calculation need not necessarily be known in this case. The z position shift of the best focus is simply measured for a given exposure device. [0090] FIG. 5 illustrates a schematic side view of a scanning exposure device in accordance with a second exemplary embodiment of the invention. The scanning exposure device of FIG. 5 has a reticle 502 , an imaging element 503 , which is illustrated schematically as an individual lens in FIG. 5 , and a carrier 504 , on which a substrate 505 is arranged. An immersion fluid introduced between the substrate 505 and the lens 503 is not illustrated in FIG. 5 for the sake of clarity. [0091] The illustration does, however, also show two planes that are intended to help to explain the functioning of the second exemplary embodiment. In the second exemplary embodiment, the carrier 504 with the substrate 505 is not moved obliquely, rather the reticle 502 is moved obliquely. By this means, too, it is possible to compensate for the shift in the z position of the sharpest image that is caused by the temperature increase and the change in refractive index correlated therewith. It must be taken into consideration in this case that an imaging element that effects a demagnification is usually used. This is illustrated symbolically in FIG. 5 by the “4×” depicted in the symbolic lens 403 . A demagnification on the scale of 4:1 has an effect at the distance of the best focus and thus in the z direction with a factor of 16, that is to say the demagnification factor squared (4: 1) 2 . This means that the reticle 502 has to be tilted to a significantly greater extent during the movement than the substrate 405 in the first exemplary embodiment illustrated in FIG. 4 . The speed in the z direction that results from equation (4) or the resulting relative angle must be increased by said factor of 16. [0092] In order to illustrate these facts, FIG. 5 , as already stated, also depicts two planes. The first plane 514 shows the “tilting” of the image of the reticle 502 generated by the lens 503 . For the reason mentioned above, this first plane 514 has a weaker degree of tilting than the reticle 502 itself. The first plane 514 specifies the position, or the tilting, which the surface to be exposed of the substrate 505 would have to have in a lithography device which would have no effects of the change in refractive index as a result of an irradiation of a medium between the lens 503 and the substrate 505 . Since, however, the invention involves the use of an immersion lithography device in which an immersion fluid is introduced between lens 503 and substrate 505 , a tilting of the image, or to put it another way a variation of the z position (distance) of the best focus, arises as a result of the change in the refractive index with the temperature. This tilting is illustrated by means of a second plane 515 in FIG. 5 . The second plane specifies the variation of the best focus as a result of the change in temperature. In order to obtain the plane of the best focus after the effects of the change in refractive index as a result of the change in temperature in the immersion fluid and the tilting of the reticle, the tilting of the first plane 514 and of the second plane 515 is “added together”. This yields the resulting imaging plane on which the image of the reticle is imaged the most sharply. In FIG. 5 , the inclinations of the first plane 514 and of the second plane 515 are illustrated such that they are equal in magnitude but have opposite signs, so that the resulting imaging plane in FIG. 5 is horizontal. [0093] Consequently, in the second exemplary embodiment illustrated in FIG. 5 , a sharp image of the reticle 502 arises on the surface to be exposed of the substrate 505 if the surface to be exposed of the substrate 505 is moved in the horizontal direction below the lens system 503 in FIG. 5 . [0094] To summarize, the invention can be seen in the fact that in an immersion lithography technology which is carried out by means of scanning exposure device, the variations in the position of the best focus, that is to say the sharpest imaging, which as a result of the change in the refractive index of the immersion medium with the change in the temperature of the immersion medium as a result of absorption in the immersion medium, in contrast to the prior art are not prevented solely by regulating the temperature of the immersion medium, rather a compensation of these focus variations is carried out by varying a distance between the reticle and a substrate surface to be exposed along the direction of movement of the substrate. The change in the distance corresponds to an offset, which is added to the normal movement of the substrate and/or reticle, that is to say the movement such as is performed by a substrate and/or reticle in an immersion lithography device in accordance with the prior art. The value of said offset can be calculated by means of equation (4) specified above. Said offset can be understood as a linear movement in the z direction, that is to say the direction of an optical axis of the scanning exposure device. In the scanning exposure device, the optical axis corresponds to the axis along which a beam, e.g. a laser beam, which is used for the exposure propagates.

The invention relates to an immersion lithography method which illuminates a substrate positioned on a carrier. When a substrate is illuminated, an immersion fluid is introduced between a reproducing element and the substrate and the field depth or the resolution, or both, are adjusted by varying the distance in the direction of the beam between an illuminating reticule and the surface of the substrate along a direction of movement of the carrier.

TECHNICAL FIELD [0001] The present invention relates to a thermal air flow sensor, a measurement device used for air flow meters, that measures air flow with a heating resistor and a resistance temperature detector. BACKGROUND ART [0002] The thermal air flow meter that can directly detect air volume has become the mainstream air flow meter. In particular, a thermal air flow meter provided with a measurement device produced by semiconductor micromachining has attracted interest as a low-cost, low-power-consumption air flow meter. For example, PTL 1 proposes a measurement device (thermal air flow sensor) for use in such thermal air flow meters. The thermal air flow sensor proposed by this publication includes an electrically insulating film formed on a semiconductor substrate, heating resistors and resistance temperature detectors formed on the electrically insulating film, and an electrical insulator formed on the heating resistors and the resistance temperature detectors. The heating resistor and resistance temperature detector region has a diaphragm structure formed by removing a portion of the semiconductor substrate from the back side by anisotropic etching. CITATION LIST Patent Document [0000] PTL 1: JP-A-2010-133897 SUMMARY OF INVENTION Technical Problem [0004] In the thermal air flow sensor proposed by PTL 1, the heating resistor and resistance temperature detector region has a diaphragm structure, and a silicon oxide film, a silicon nitride film, and a silicon oxide film are laminated on the surfaces of these resistors by using a plasma CVD (chemical vapor deposition) method. Films formed by CVD are typically coarse (low atom density), and are subjected to a high-temperature (1,000° C.) heat treatment to densify the films. The silicon nitride film generates a particularly high stress during this heat treatment. [0005] The heating resistor and the resistance temperature detector are formed by deposition and patterning of a metal film such as a molybdenum film, and the surfaces of the silicon oxide film and the silicon nitride film deposited on these surfaces have steps conforming to the thickness of the metal film. The high stress in the silicon nitride film concentrates in these step portions, and may cause cracking in the film. The cracks allow entry of oxygen and moisture from the surface, and cause the resistors to oxidize. The oxidation varies the resistance of the resistors as it progresses, and produces measurement errors in the air flow meter. [0006] It is an object of the invention to provide a thermal air flow sensor that produces less measurement error. Solution to Problem [0007] In order to achieve the foregoing object, a thermal air flow sensor of the invention includes a semiconductor substrate; a heating resistor, resistance temperature detectors, and an electrical insulator that includes a silicon oxide film, wherein the heating resistor, the resistance temperature detectors, and the electrical insulator are formed on the semiconductor substrate; and a diaphragm portion formed by removing a portion of the semiconductor substrate, the heating resistor and the resistance temperature detectors being formed on the diaphragm portion, and the thermal air flow sensor further comprising a silicon nitride film formed as the electrical insulator above the heating resistor and the resistance temperature detectors, wherein the silicon nitride film has steps conforming to the patterns of the heating resistor and the resistance temperature detectors, and wherein the silicon nitride film has a multilayer structure. Advantage Effects of Invention [0008] With the invention, a thermal air flow sensor can be provided that produces less measurement error. BRIEF DESCRIPTION OF DRAWINGS [0009] FIG. 1 is a schematic plan view of a measurement device of First Embodiment of the present application. [0010] FIG. 2 is a cross sectional view of First Embodiment according to the present application. [0011] FIG. 3 is a diagram representing a distribution of the generated stress in a silicon nitride film. [0012] FIG. 4 is a diagram showing that the generated stress in a silicon nitride film is dependent on silicon nitride film thickness. [0013] FIG. 5 is a photographic representation of interface formation after the deposition of a second silicon nitride film on a first silicon nitride film. [0014] FIG. 6 is a cross sectional view of Second Embodiment of the present application. [0015] FIG. 7 is a diagram representing the dependence of steps on the generated stress in a silicon nitride film. [0016] FIG. 8 is a diagram representing how the steps of a silicon oxide film are reduced by mechanical polishing and etch back. [0017] FIG. 9 is a diagram representing hillock formation on heating resistors and resistance temperature detectors. DESCRIPTION OF EMBODIMENTS [0018] Embodiments of the invention are described below. Embodiment 1 [0019] A thermal air flow sensor as First Embodiment of the invention is described below with reference to FIGS. 1 and 2 . FIG. 1 is a schematic plan view of the thermal air flow sensor. FIG. 2 is a cross sectional view taken at A-A′ of FIG. 1 . [0020] As illustrated in FIG. 1 , the thermal air flow sensor (a measurement device used for a thermal air flow meter) of the present embodiment is configured to include a silicon substrate 1 , heating resistors 10 , resistance temperature detectors 9 and 11 for measuring air temperature, terminal electrodes 12 , and a diaphragm portion 6 . The diaphragm portion 6 has an end portion 8 . [0021] A producing method of the present embodiment is described below with reference to FIG. 2 . [0022] The silicon substrate 1 is thermally oxidized to form a thermally oxidized film 2 that becomes a lower electrically insulating film. A molybdenum (Mo) film is then deposited on the thermally oxidized film 2 in a thickness of about 150 nm, and the heating resistors 10 and the resistance temperature detectors 9 and 11 are formed by patterning. The lower electrically insulating film may be formed solely by the thermally oxidized film 2 , or may be formed as a laminate with a silicon nitride (SiN) film or a silicon oxide film (SiO 2 ). The structure heating resistors 10 , and the resistance temperature detectors 9 and 11 may be formed by using a metal film, such as platinum, instead of using the molybdenum film. Thereafter, a silicon oxide film 3 (upper electrically insulating film) is deposited on the heating resistors 10 and the resistance temperature detectors 9 and 11 in a thickness of about 500 nm by using a plasma CVD method. This is followed by a heat treatment at a temperature of 800° C. or more to densify the film. The heat treatment forms steps 13 corresponding to the thickness of the deposited molybdenum. A silicon nitride film 4 is then formed in a thickness of about 200 nm by a two-step deposition procedure. Here, a heat treatment is always performed after each deposition, specifically after the first deposition and the second deposition of the silicon nitride film. The heat treatments are performed at 800° C. or more, a temperature that allows the silicon nitride film to be densified. Because the silicon nitride film 4 is deposited on the steps 13 of the silicon oxide film 3 , the silicon nitride film 4 formed has steps 14 . Thereafter, a silicon oxide film 5 is deposited in a thickness of 300 to 500 nm by using a plasma CVD method, and a heat treatment is performed at 800° C. or more. This is followed by deposition and patterning of a polyimide-based resin film to form a PIQ film 15 . Referring to FIG. 1 , the terminal electrodes 12 are formed by depositing aluminum, gold, or the like through contact holes formed through the upper electrically insulating film after forming the silicon oxide film 5 (not illustrated). Finally, the diaphragm portion 6 is formed from the back surface, using a silicon oxide film or the like as masking material, and an etchant such as KOH (not illustrated). The diaphragm portion 6 may be formed by using a dry etching method. Referring to FIG. 2 , the etching mask (masking material) has an end portion 7 . The masking material covers the area outside the etching mask end portion 7 , and etching removes the silicon substrate material in the region of the diaphragm portion 6 . [0023] In the present embodiment, the upper electrically insulating film has a three-layer structure configured from the silicon oxide film 3 , the silicon nitride film 4 , and the silicon oxide film 5 . However, the upper electrically insulating film may be configured from more than three layers. [0024] Advantages of the present embodiment are described below. [0025] The present inventors conducted studies to find the cause of the cracking the occurs when the silicon nitride film 4 is formed as a monolayer film, and found that cracks are caused by a high tensile stress, as high as 1,000 MPa, that generates inside the film, and concentrates on the surfaces of the steps 14 as a result of the silicon nitride film 4 being densified by the high-temperature heat treatment performed after the deposition of the silicon nitride film 4 . [0026] In the thermal air flow sensor, the heating resistors 10 generate heat of about 200 to 300° C. at all times, and the sensitivity of the air flow sensor increases as the heating temperature increases. The heat of the heating resistors 10 heats the thermally oxidized film 2 , the silicon oxide film 3 , the silicon nitride film 4 , and the silicon oxide film 5 disposed in the vicinity. The film stress of these films varies with the temperature of heat treatment. Thus, absent a high-temperature heat treatment, the heat of the heating resistors 10 varies the film stress, and deforms the diaphragm. This causes air flow detection errors as the resistance values of the heating resistors 10 and the resistance temperature detectors 9 and 11 vary because of the piezoresistive effect. In the present embodiment, this is prevented by the heat treatment of 800° C. or more, which is always performed after the deposition of the upper and lower electrically insulating films. [0027] In common LSIs, aluminum is used for the wiring material, and electrically insulating films such as a silicon oxide film and a silicon nitride film are formed after the deposition of the aluminum film. Because the melting point of aluminum is about 550° C., the deposition of the silicon oxide film and the silicon nitride film on the aluminum is not followed by high-temperature annealing of 500° C. or more, and the silicon nitride film does not generate high tensile stress. Further, the heat-induced film stress changes hardly occur because of the low heat generation, at most 125° C., of the LSI. Further, because the LSI does not have a diaphragm structure, there is hardly any substrate bending due to film stress changes, and the electrical properties of the LSI remain unaffected. The cracking problem of the silicon nitride film 4 is indeed specific to thermal air flow sensors. [0028] FIG. 3 represents the result of the analysis of the generated stress in the silicon nitride film 4 . It can be seen that the stress is concentrated in the surface of the silicon nitride film 4 . FIG. 4 shows that the stress is dependent on the thickness of the silicon nitride film 4 . The stress decreases with decrease in thickness. It is tempting to think from this result that the stress can be effectively reduced by making the silicon nitride film 4 thinner. However, reducing the thickness of the silicon nitride film 4 lowers the diaphragm strength against dust collisions, and it is not desirable to reduce the thickness of the silicon nitride film 4 . [0029] The stress concentrated in surface portions of the silicon nitride film 4 , as shown in FIG. 3 . The cause of the generated stress in the silicon nitride film 4 was the film contraction due to heat treatment. Less stress generated when the silicon nitride film 4 was made thinner. Reducing the film thickness lowers stress because the thinner thickness involves less film contraction. It is therefore considered possible to lower the surface stress by providing the silicon nitride film 4 as a multilayer film, and reducing the film thickness of the last layer. Specifically, a heat treatment is performed after the deposition of the first layer to contract the film, and a heat treatment is also performed after the second deposition. In this way, the surface stress generated in the silicon nitride film 4 only comes from the contraction of the second layer film, and the generated stress can be reduced without varying the film thickness. [0030] This method involves interface formation between the first layer and the second layer, as shown in FIG. 5 . As to the thickness ratio of the first and second layers in the two-layer structure, the effect remains even when the second layer is thicker than the first layer, because the second layer will still be thinner than the total thickness. However, the stress can be reduced more effectively when the second layer is thinner than the first layer. [0031] The silicon nitride film 4 , described as having a two-layer structure in the foregoing First Embodiment, may have a three- or four-layer structure. [0032] In any case, the surface stress generated in the silicon nitride film 4 can be effectively reduced when the films in the multilayer structure have the same thickness, or when the film formed last is the thinnest of the other films in the multilayer structure. Embodiment 2 [0033] Second Embodiment differs from First Embodiment only in the producing method, and will be described with respect to the producing method, with reference to FIG. 6( a ) to ( c ). [0034] As shown in FIG. 6( a ), the silicon substrate 1 is thermally oxidized to form a thermally oxidized film 2 that becomes a lower electrically insulating film. A molybdenum (Mo) film is then deposited on the thermally oxidized film 2 in a thickness of 150 nm, and the heating resistors 10 and the resistance temperature detectors 9 and 11 are formed by patterning. The lower electrically insulating film may be formed solely by the thermally oxidized film 2 , or may be formed as a laminate with a silicon nitride (SiN) film or a silicon oxide film (SiO 2 ). The heating resistors 10 , and the resistance temperature detectors 9 and 11 may be formed by using a metal film, such as platinum, instead of using the molybdenum film. Thereafter, a silicon oxide film 3 (upper electrically insulating film) is deposited on the heating resistors 10 and the resistance temperature detectors 9 and 11 in a thickness of about 600 nm to 700 nm by using a plasma CVD method. This is followed by a heat treatment at a temperature of 800° C. or more to densify the film. The heat treatment forms steps 13 corresponding to the thickness. The steps 14 are then planarized by mechanical polishing (CMP) to make the thickness of the silicon oxide film 3 about 500 nm, as shown in FIG. 6( b ). As used herein, “planarize” means eliminating steps that conform to the patterns of the heating resistors 10 and the resistance temperature detectors 9 and 11 . A silicon nitride film 4 is then deposited in a thickness of about 200 nm, and a heat treatment is performed at 800° C. or more to densify the silicon nitride film 4 , as shown in FIG. 6( c ). Thereafter, a silicon oxide film 5 is deposited in a thickness of 300 to 500 nm by using a plasma CVD method, and a heat treatment is performed at 800° C. or more. The terminal electrodes 12 , and the diaphragm portion 6 are then formed in the same manner as in Embodiment 1. [0035] Advantages of the present embodiment are described below. [0036] The cause of the cracking that occurs in the silicon nitride film 4 is the high film stress, and the stress concentration due to the step formation. In Embodiment 1, this is counteracted by reducing the film stress. In Embodiment 2, the steps 14 are removed by mechanical polishing to suppress stress concentration and the stress-induced crack generation. [0037] The common planarization procedures used in LSI wiring layer formation is intended to eliminate the contact failure of the contact wires connecting the lower layer wiring and the upper layer wiring. This is in contrast to the present embodiment in which the planarization prevents the crack generation in the electrically insulating film. That is, the purpose of the planarization is different. [0038] The stress can be reduced by reducing the steps as shown in FIG. 7 , instead of completely planarizing the silicon oxide film 3 in the manner as shown in FIG. 6( b ). Because the steps can be reduced by using mechanical polishing or etch back, the generated stress can be reduced to suppress crack generation. Needless to say, the amount of etching is less than the thickness of the heating resistors 10 and the resistance temperature detectors 9 and 11 . Further, as shown in FIG. 8 , the thickness of the silicon oxide film 3 after the mechanical polishing satisfies the relation B>A, where A is the thickness of the region where the heating resistors 10 and the resistance temperature detectors 9 and 11 are deposited, and B is the thickness of the region where these members are not deposited. The steps 14 conforming to the patterns of the heating resistors 10 and the resistance temperature detectors 9 and 11 are retained. [0039] The step reduction may be accompanied by the multilayer structure of the silicon nitride 4 described in Embodiment 1. In this way, the stress can be reduced further, and cracks can be effectively suppressed. [0040] High-temperature annealing of the heating resistors 10 and the resistance temperature detectors 9 and 11 with metallic materials may produce hillocks 16 (local protuberances), as shown in FIG. 9 . Such hillocks 16 add to the steps 13 , and increase the stress. The methods described in Embodiments 1 and 2 are thus particularly effective against such hillocks 16 . REFERENCE SIGNS LIST [0000] 1 Silicon substrate 2 Thermally oxidized film 3 , 5 Silicon oxide film 4 Silicon nitride film 6 Diaphragm portion 7 End portion of etching mask 8 End portion of diaphragm portion 9 , 11 Resistance temperature detectors 10 Heating resistors 12 Terminal electrodes 13 , 14 Steps 15 PIQ film 16 Hillocks

A thermal air flow sensor that produces less measurement error is provided. The thermal air flow sensor includes: a semiconductor substrate; a heating resistor, resistance temperature detectors, and an electrical insulator that includes a silicon oxide film, wherein the heating resistor, the resistance temperature detectors, and the electrical insulator are formed on the semiconductor substrate; and a diaphragm portion formed by removing a portion of the semiconductor substrate. The heating resistor and the resistance temperature detectors are formed on the diaphragm portion. The thermal air flow sensor further includes a silicon nitride film formed as the electrical insulator above the heating resistor and the resistance temperature detectors. The silicon nitride film has steps conforming to the patterns of the heating resistor and the resistance temperature detectors. The silicon nitride film has a multilayer structure.

CLAIM FOR PRIORITY This application is a continuation of U.S. patent application Ser. No. 11/090,246, filed on Mar. 25, 2005 now U.S. Pat. No. 7,112,929 and entitled “Full-Bridge and Half-Bridge Compatitle Driver Timing Schedule for Direct Drive Backlight System,” which claims the benefit of priority under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 60/558,512, filed on Apr. 1, 2004 and entitled “Full-Bridge and Half-Bridge Compatible Driver Timing Schedule for Direct Drive Backlight System,” each of which is hereby incorporated by reference herein in their entirety. BACKGROUND 1. Field of the Invention The invention generally relates to a driver circuit in a backlight system for powering fluorescent lamps, and more particularly, relates to a driver circuit with a power efficient timing schedule that can flexibly drive either a half-bridge or a full-bridge switching network in the backlight system. 2. Description of the Related Art Fluorescent lamps are used in a number of applications where light is required but the power required to generate the light is limited. One particular type of fluorescent lamp is a cold cathode fluorescent lamp (CCFL). CCFLs are used for back or edge lighting of liquid crystal displays (LCDs) which are typically found in notebook computers, web browsers, automotive and industrial instrumentation, and entertainment systems. A power converter (e.g., an inverter) is typically used to power a fluorescent lamp. The inverter includes a controller and a switching network to convert a direct current (DC) source into an alternating current (AC) source to power the fluorescent lamp. In a half-bridge switching network, a pair of transistors is coupled to the DC source and the transistors alternately conduct to generate the AC source. In a full-bridge switching network, an arrangement of four transistors is coupled to the DC source and the transistors conduct in pairs to generate the AC source. The controller controls transistors in the switching network. Controllers designed for half-bridge switching networks typically cannot operate full-bridge switching networks, and controllers designed for full-bridge switching networks typically do not have outputs compatible for operating half-bridge networks. SUMMARY Embodiments advantageously include driver circuits (or controllers) that can switch between half-bridge and full-bridge operations without modification, redundant circuitry or additional components. In one embodiment, a controller for flexibly driving a half-bridge or a full-bridge switching network in a backlight inverter includes four outputs. A first output of the controller provides a first driving signal with periodic active and inactive states. A second output of the controller provides a second driving signal with active states that are phase shifted by approximately 180° with respect to the active states of the first driving signal. The first and the second driving signals have variable and substantially identical duty cycles that determine relative durations of the active and the inactive states. A third output of the controller provides a third driving signal that substantially follows the first driving signal with opposite states and transition overlaps. For example, the first driving signal and the third driving signal are alternately active with overlapping inactive states during state transitions. The third driving signal transitions from an active state to an inactive state before the first driving signal transitions from an inactive state to an active state. The third driving signal also transitions from an inactive state to an active state after the first driving signal transitions from an active state to an inactive state. A fourth output of the controller provides a fourth driving signal that substantially follows the second driving signal with opposite states and transitions overlaps. For example, the second driving signal and the fourth driving signal are alternately active with overlapping inactive states during state transitions. The fourth driving signal transitions from an active state to an inactive state before the second driving signal transitions from an inactive state to an active state. The fourth driving signal also transitions from an inactive state to an active state after the second driving signal transitions from an active state to an inactive state. In one embodiment, a first semiconductor switch (or power transistor) and a second semiconductor switch are arranged in a half-bridge switching network of a direct-drive inverter. For example, the semiconductor switches are coupled between ground and respective opposite terminals of a primary winding of a transformer. A power source (e.g., a supply voltage or a current source) is coupled to a center tap of the primary winding of the transformer. A lamp load (e.g., one or more fluorescent lamps or cold cathode fluorescent lamps) is coupled across a secondary winding of the transformer. The semiconductor switches (e.g., N-type transistors) in the half-bridge switching network can be advantageously controlled by the first driving signal and the second driving signal to generate an AC signal for powering the lamp load. For example, the first driving signal and the second driving signal cause the first semiconductor switch and the second semiconductor switch to alternately conduct. Power flows from the power source to the lamp load in a first polarity when the first semiconductor switch is on and the second semiconductor switch is off. Power flows from the power source to the lamp load in a second polarity when the second semiconductor switch is on and the first semiconductor switch is off. Substantially no power flows from the power source to the lamp load when both semiconductor switches are on or off. In one embodiment, four semiconductor switches are coupled to a primary winding of a transformer in a full-bridge configuration. The four driving signals respectively control the four semiconductor switches to generate an AC lamp signal for powering a lamp load coupled across a secondary winding of the transformer. For example, the first driving signal controls the first semiconductor switch coupled between a first terminal of the primary winding and ground. The second driving signal controls the second semiconductor switch coupled between a second terminal of the primary winding and ground. The third driving signal controls the third semiconductor switch coupled between a power source and the first terminal of the primary winding. Finally, the fourth driving signal controls the fourth semiconductor switch coupled between the power source and the second terminal of the primary winding. The four driving signals establish a periodic timing sequence that advantageously improves power efficiency. For example, the transition overlaps between the first and the third driving signals and the transitions overlaps between the second and the fourth driving signals facilitate reduced-voltage (or zero-voltage) switching to improve power efficiency. Conduction states and idles states are interposed between the different transition overlaps in the periodic timing sequence. For example, a first conduction state allows power to flow from the power source to the lamp load in a first polarity when the first and the fourth semiconductor switches are on while the second and the third semiconductor switches are off. A second conduction state allows power to flow from the power source to the lamp load in an opposite polarity when the first and the fourth semiconductor switches are off while the second and the third semiconductor switches are on. Substantially no power is provided by the power source during the idle states in which the first and the second semiconductor switches are on or the third and the fourth semiconductor switches are on. In one embodiment, the first and the second semiconductor switches are N-type field-effect-transistors (NFETs) while the third and the fourth semiconductor switches are P-type FETs (PFETs). Thus, the active states of the first and the second driving signals correspond to logic high while the active states of the third and the fourth driving signals correspond to logic low. The third and the fourth driving signals have rising edges that precede respective rising edges of the first and the second driving signals by a first duration. The third and the fourth driving signals have falling edges that trail respective falling edges of the first and the second driving signals by a second duration. In one embodiment, the four driving signals are generated from a pair of input signals and four delay circuits. For example, a first input signal is provided to a first delay circuit that is coupled in series with a second delay circuit. A second input signal is provided to a third delay circuit that is coupled in series with a fourth delay circuit. In one application in which the first and the second driving signals have overlapping inactive states, the first delay circuit outputs the first driving signal. An output of the second delay circuit is ORed with the first input signal to generate the third driving signal. The third delay circuit outputs the second driving signal. An output of the fourth delay circuit is ORed with the second input signal to generate the fourth driving signal. In another application in which the first and the second driving signals have overlapping inactive states, the first delay circuit outputs the first driving signal. The output of the second delay circuit is provided to a first edge-triggered one-shot circuit that has an output coupled to a reset terminal of a first SR latch. The first input signal is provided to a set terminal of the first SR latch. The first SR latch outputs the third driving signal. The third delay circuit outputs the second driving signal. The output of the fourth delay circuit is provided to a second edge-triggered one-shot circuit that has an output coupled to a reset terminal of a second SR latch. The second input signal is provided to a set terminal of the second SR latch. The second SR latch outputs the fourth driving signal. In one application in which the first and the second driving signals have overlapping active states, the output of the first delay circuit is inverted to generate the fourth driving signal. The output of the second delay circuit is NORed with the first input signal to generate the second driving signal. The output of the third delay circuit is inverted to generate the third driving signal. The output of the fourth delay circuit is NORed with the second input signal to generate the first driving signal. In another application in which the first and the second driving signals have overlapping active states, the output of the first delay circuit is inverted to generate the fourth driving signal. The output of the second delay circuit is provided to a first one-shot circuit that has an output coupled to a reset terminal of a first latch. The first input signal is coupled to a set terminal of the first latch. The first latch generates the second driving signal. The output of the third delay circuit is inverted to generate the third driving signal. The output of the fourth delay circuit is provided to a second one-shot circuit that has an output coupled to a reset terminal of a second latch. The second input signal is provided to a set terminal of the second latch. The second latch generates the first driving signal. For purposes of summarizing the invention, certain aspects, advantages and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. BRIEF DESCRIPTION OF THE DRAWINGS These drawings and the associated description herein are provided to illustrate embodiments and are not intended to be limiting. FIG. 1 illustrates one embodiment of a direct drive backlight system implemented with a half-bridge switching network. FIG. 2 illustrates one timing scheme for driving power transistors in the half-bridge switching network of FIG. 1 . FIG. 3 illustrates one embodiment of a direct drive backlight system implemented with a full-bridge switching network. FIG. 4 illustrates one timing scheme for controlling power transistors in the full-bridge switching network of FIG. 3 . FIGS. 5( a )- 5 ( h ) illustrate one embodiment of a periodic timing sequence for a full-bridge switching network employing a zero-voltage switching technique to improve power efficiency. FIG. 6 illustrates one embodiment of driving waveforms to control transistors in a full-bridge switching network in accordance with the periodic timing sequence depicted in FIGS. 5( a )- 5 ( h ). FIG. 7 illustrates one embodiment of a controller circuit for generating the driving waveforms shown in FIG. 6 . FIG. 8 is a timing diagram for some signals in the controller circuit of FIG. 7 . FIG. 9 illustrates another embodiment of a controller circuit for generating the driving waveforms shown in FIG. 6 . FIG. 10 is a timing diagram for some signals in the controller circuit of FIG. 9 . FIGS. 11( a )- 11 ( h ) illustrates another embodiment of a periodic timing sequence for a full-bridge switching network that further improves power efficiency. FIG. 12 illustrates one embodiment of driving waveforms to control transistors in a full-bridge switching network in accordance with the periodic timing sequence depicted in FIGS. 11( a )- 11 ( h ). FIG. 13 illustrates one embodiment of a controller circuit for generating the driving waveforms shown in FIG. 12 . FIG. 14 illustrates another embodiment of a controller circuit for generating the driving waveforms shown in FIG. 12 . DETAILED DESCRIPTION OF EMBODIMENTS Although particular embodiments are described herein, other embodiments, including embodiments that do not provide all of the benefits and features set forth herein, will be apparent to those of ordinary skill in the art. FIG. 1 illustrates one embodiment of a direct drive backlight system implemented with a half-bridge switching network. Two power transistors (or semiconductor switches) 100 , 102 are coupled between circuit ground and respective opposite terminals of a primary winding of a transformer 104 . A power source (VP) is coupled to a center tap of the primary winding of the transformer 104 . The power source can be a supply voltage or a current source. A lamp load 106 is coupled across a secondary winding of the transformer 104 . The lamp load 106 can include one or more lamps, such as fluorescent lamps or CCFLs. Other half-bridge network configurations including two power transistors are also possible and may exclude a transformer for coupling to a lamp load. A controller (not shown) outputs two driving signals to control the semiconductor switches 100 , 102 . For example, the first driving signal (Aout) controls the first semiconductor switch (QA) 100 and the second driving signal (Bout) controls the second semiconductor switch (QB) 102 . The driving signals configured the semiconductor switches 100 , 102 to alternately conduct to establish an AC current in the primary winding and the second winding of the transformer 104 . In a first conduction state, power flows from the power source (or supply source) to the lamp load 106 in a first polarity when the first semiconductor switch 100 is on and the second semiconductor switch 102 is off. In a second conduction state, power flows from the power source to the lamp load 106 in a second (or opposite) polarity when the second semiconductor switch 102 is on and the first semiconductor switch 100 is off. Idle (or power-off) states can be inserted in between the conduction states. During the idle states, the semiconductor switches 100 , 102 are both on (e.g., if the power source is a current source) or both off (e.g., if the power source is a voltage source) and substantially no power flows from the power source to the lamp load 106 . FIG. 2 illustrates one timing scheme for driving (or controlling conduction states of) the power transistors 100 , 102 in the half-bridge switching network of FIG. 1 . In the embodiment shown in FIG. 1 , the power transistors 100 , 102 are NFETs with driving signals coupled to respective gate terminals of the power transistors 100 , 102 . Logic high in the driving signals corresponds to turning on the power transistors 100 , 102 (or an active state) while logic low in the driving signals corresponds to turning off the power transistors 100 , 102 (or an inactive state). A graph 200 illustrates a first driving signal (Aout) with respect to time for driving the first power transistor 100 . A graph 202 illustrates a second driving signal (Bout) with respect to time for driving the second power transistor 102 . The driving signals are periodically and alternately active (or logic high) for a first predetermined duration (Ta). For example, the first driving signal is active for the first predetermined duration during times T 1 -T 2 and T 5 -T 6 . The second driving signal is active for the first predetermined duration during times T 3 -T 4 and T 7 -T 8 . Rest periods of a second predetermined duration (Tb) are inserted in between the alternate active states of the driving signals (e.g., during times T 2 -T 3 , T 4 -T 5 and T 6 -T 7 ). The driving signals are both inactive (or logic low) during the rest periods. Alternately, the driving signals can be both active during the rest periods. Thus, the power transistors 100 , 102 alternately switch on (or conduct) between periods of rest using the timing scheme illustrated in FIG. 2 . Power flows from the power source to the lamp load 106 in a first polarity when the first driving signal is active. Power flows from the power source to the lamp load 106 in a second polarity when the second driving signal is active. Substantially no power flows from the power source to the lamp load 106 when the first and the second driving signals are both active or both inactive. The alternating conduction by the power transistors 100 , 102 between the rest periods results in a substantially AC waveform for powering the lamp load 106 . An AC current (or lamp current) flows through a lamp in the lamp load 106 to illuminate the lamp. The brightness or effective power delivered to the lamp is dependent on the power source and switching duty-cycle (i.e., Ta/Tb). FIG. 3 illustrates one embodiment of a direct drive backlight system implemented with a full-bridge (or H-bridge) switching network. Four power transistors 300 , 302 , 304 , 306 are coupled to a primary winding of a transformer 308 . For example, a first pair of power transistors (QA, QB) 300 , 302 is coupled between respective opposite terminals of the primary winding and circuit ground. A second pair of power transistors (QC, QD) 304 , 306 is coupled between the respective opposite terminals of the primary winding and a power source (VP) to complete the H-bridge switching network. A lamp load (e.g., a fluorescent lamp) 310 is coupled across a secondary winding of the transformer 308 . Four driving signals (Aout, Bout, Cout, Dout) respectively control the four power transistors 300 , 302 , 304 , 306 to generate an AC lamp signal for powering the lamp load 310 coupled across the secondary winding of the transformer 308 . For example, the first driving signal (Aout) controls the first power transistors (QA) 300 coupled between a first terminal of the primary winding and ground. The second driving signal (Bout) controls the second power transistor (QB) 302 coupled between a second terminal of the primary winding and ground. The third driving signal (Cout) controls the third power transistor (QC) 304 coupled between the power source and the first terminal of the primary winding. Finally, the fourth driving signal (Dout) controls the fourth power transistor (QD) 306 coupled between the power source and the second terminal of the primary winding. A full-bridge switching network has some advantages over a half-bridge switching network. For example, the transformer 308 of FIG. 3 generally costs less than the transformer 104 of FIG. 1 due to reduced primary-to-secondary turns ratio and lack of a center tap. Power transistors used in the full-bridge switching network generally cost less than power transistors used in the half-bridge switching network due to reduced breakdown voltage requirement. The power transistors in the half-bridge switching network have a breakdown voltage that is comparable to at least twice a supply voltage while the power transistors in the full-bridge switching network have a breakdown voltage that is comparable to at least the supply voltage. FIG. 4 illustrates one timing scheme for controlling the power transistors 300 , 302 , 304 , 306 in the full-bridge switching network of FIG. 3 . In the embodiment shown in FIG. 3 , the first pair of power transistors 300 , 302 are NFETs and the second pair of power transistors 304 , 306 are PFETs. The driving signals (Aout, Bout, Cout, Dout) are coupled to respective gate terminals of the power transistors 300 , 302 , 304 , 306 . Logic high in the first two driving signals (Aout, Bout) corresponds to turning on the first pair of power transistors 300 , 302 (or an active state). Logic low in the last two driving signals (Cout, Dout) corresponds to turning on the second pair of power transistors 304 , 306 (or an active state). A graph 400 illustrates the first driving signal (Aout) with respect to time for driving the first power transistor 300 . A graph 402 illustrates the second driving signal (Bout) with respect to time for driving the second power transistor 302 . A graph 404 illustrates the fourth driving signal (Dout) with respect to time for driving the fourth power transistor 306 . A graph 406 illustrates the third driving signal (Cout) with respect to time for driving the third power transistor 304 . The first and the second driving signals illustrated in FIG. 4 is substantially similar to the driving signals illustrated in FIG. 2 for the half-bridge switching network. The fourth driving signal is an inverted form of the first driving signal, and the third driving signal is an inverted form of the second driving signal. Thus, the first and the fourth power transistors 300 , 306 are switched on and off at approximately the same times while the second and the third power transistors 302 , 304 are switched on and off at approximately the same times. Referring to FIG. 3 , current flows from the second terminal to the first terminal of the primary winding of the transformer 308 and power transfers from the power source to the lamp load 310 in a first polarity during first conduction states when the first driving signal is logic high (or active) and the fourth driving signal is logic low (or active). Current flows from the first terminal to the second terminal of the primary winding of the transformer 308 and power transfers from the power source to the lamp load 310 in a second polarity during second conduction states when the second driving signal is logic high (or active) and the third driving signal is logic low (or active). Substantially no power transfers from the power source to the lamp load 310 during idle states when the first and the second driving signals are both inactive (or logic low) as shown in FIG. 4 . FIGS. 5( a )- 5 ( h ) illustrate one embodiment of a periodic timing sequence for the full-bridge switching network of FIG. 3 that employs a zero-voltage switching technique to generate an AC lamp signal for powering the lamp load 310 with improved power efficiency. The power transistors 300 , 302 , 304 , 306 are represented by schematically equivalent single-pole-single-throw switches. The lamp load 310 coupled across the transformer 308 is not shown for clarity of illustration. FIG. 5( a ) illustrates a first conduction state (or step) in which the first power transistor (QA) 300 and the fourth power transistor (QD) 306 are on while the second power transistor (QB) 302 and the third power transistor (QC) 304 are off to allow power to flow from the power source (VP) to the lamp load 310 in a first polarity. For example, current flows from the power source through the fourth power transistor 306 , through the primary winding of the transformer 308 and through the first power transistor 300 to ground during the first conduction state. FIGS. 5( b )- 5 ( d ) illustrate intermediate steps to transition from the first conduction state to a second conduction state illustrated in FIG. 5( e ). FIG. 5( b ) shows a first transition state (or first intermediate step), following the first conduction state, in which the first power transistor 300 turns off. Because of leakage inductance associated with the transformer 308 , the current through the primary winding of the transformer 308 does not stop instantaneously. The current flowing through the primary winding of the transformer 308 finds a path through a body diode 500 of the third power transistor 304 and back to the power source. The body diode 500 has an anode coupled to the first terminal of the primary winding and a cathode coupled to the power source. With the body diode 500 conducting, the drain-to-source voltage of the third power transistor 304 is relatively low (e.g., approximately 0.7 volt or one diode voltage drop). FIG. 5( c ) shows a first idle state (or second intermediate step), following the first transition state, in which the third power transistor 304 turns on. Turning on the third power transistor 304 after its body diode 500 starts conducting takes advantage of close to zero (or reduced) voltage switching to thereby reduce switching loss. It should be noted that although current continues to flow through the primary winding of the transformer 308 during the idle state, no power is drawn from the power source. FIG. 5( d ) shows a second transition state (or third intermediate step), following the first idle state, in which the fourth power transistor 306 turns off. Similar to the first transition step, the current flowing through the primary winding of the transformer 308 does not stop abruptly. The current flowing through the primary winding of the transformer 308 finds a path from ground through a body diode 502 of the second power transistor 302 . The body diode 502 has an anode coupled to ground and a cathode coupled to the second terminal of the primary winding. FIG. 5( e ) shows the second conduction state, following the second transition state, in which the second power transistor 302 turns on to allow power to flow from the power source to the lamp load 310 in a second polarity. The second power transistor 302 turns on after its body diode 502 starts conducting to take advantage of reduced-voltage (or zero-voltage) switching. In the second conductions state, current flows from the power source through the third power transistor 304 , through the primary winding of the transformer 308 and through the second power transistor 302 to ground. The current flows in opposite (or reverse) directions through the primary winding of the transformer 308 between the first and the second conduction states. FIGS. 5( f )- 5 ( h ) illustrate another set of intermediate steps, following the same principles shown in FIGS. 5( b )- 5 ( d ), to transition from the second conduction state back to the first conduction state. For example, FIG. 5( f ) shows a third transition state, following the second conduction state, in which the second power transistor 302 turns off and the current flowing the primary winding of the transformer 308 finds a path to the power source through a body diode 504 of the fourth power transistor 306 . The body diode 504 has an anode coupled to the second terminal of the primary winding and a cathode coupled to the power source. FIG. 5( g ) shows a second idle state, following the third transition state, in which the fourth power transistor 306 turns on using zero-voltage switching. FIG. 5( h ) shows a fourth transition state, following the second idle state, in which the third power transistor 304 turns off and the current flowing through the primary winding of the transformer 308 finds a path to ground through a body diode 506 of the first power transistor 300 . The body diode 506 has an anode coupled to ground and a cathode coupled to the first terminal of the primary winding. The first power transistor 300 turns on using zero-voltage switching in the next step of the periodic timing sequence to return to the first conduction state. The zero-voltage switching technique turns on (or closes) a power transistor (or switch) when the voltage across the power transistor (or source-to-drain voltage of a FET) is at a minimum (or reduced) voltage (e.g., 0.7 volt or substantially zero volt). The zero-voltage switching technique reduces switching power loss due to discharging of the drain-to-source capacitance associated with turning on the power transistor. FIG. 6 illustrates one embodiment of driving waveforms to control transistors in a full-bridge switching network in accordance with the periodic timing sequence depicted in FIGS. 5( a )- 5 ( h ). For example, a controller includes four outputs to drive the full-bridge switching network in a backlight inverter. The controller can also flexibly drive a half-bridge switching network with two of the four outputs. The first output of the controller provides a first driving signal (Aout) with periodic active and inactive states. The first driving signal has a variable duty-cycle that determines relative durations of the active and the inactive states, which is one way to control backlight intensity (or amount of power provided to the lamp load 310 ). A graph 600 illustrates the first driving signal with respect to time. In one embodiment, the first driving signal controls the first power transistor 300 which is shown as an NFET with logic high corresponding to active states. The graph 600 shows the first driving signal with periodic active states of a first duration (Ta) (e.g, from times T 1 -T 2 and T 9 -T 10 ). The second output of the controller provides a second driving signal (Bout) that has a substantially identical duty-cycle as the first driving signal and is substantially an 180° phase-shifted version of the first driving signal. In other words, the active states of the second driving signal are phased shifted by approximately 180° with respect to the active states of the first driving signal to provided complementary switching. A graph 602 illustrates the second driving signal with respect to time. In one embodiment, the second driving signal controls the second power transistor 302 which is shown as an NFET with logic high corresponding to active states. The graph 602 shows the second driving signal with periodic active states of the first duration (Ta) (e.g., from times T 5 -T 6 and T 13 -T 14 ). The active states of the second driving signal is phase shifted by 180° from (or occurs in between) the active states of the first driving signal. The first and the second driving signals can advantageously be used to control alternating conduction by switches in a half-bridge switching network. The third output of the controller provides a third driving signal (Cout) that substantially follows (or tracks) the first driving signal with opposite (or opposing) states and transition overlaps. A graph 606 shows the third driving signal. In one embodiment, the third driving signal controls the third power transistor 304 which is shown as a PFET with logic low corresponding to active states. With opposing states, the first power transistor 300 and the third power transistor 304 are alternately on. With transition overlaps, the third power transistor 304 turns off before the first power transistor 300 turns on and the third power transistor 304 turns on after the first power transistor 300 turns off. The graph 606 shows the third driving signal with periodic inactive states that exceed the first duration (e.g., from times T 0 -T 3 and T 8 -T 11 ). Thus, the third driving signal is substantially similar to the first driving signal except the leading (or rising) edge of the third driving signal precedes the leading edge of the first driving signal by a first overlapping duration and the trailing (or falling) edge of the third driving signal succeeds the trailing edge of the first driving signal after a second overlapping duration. In other words, the third driving signal transitions from an active state (i.e., logic low) to an inactive state (i.e., logic high) before the first driving signal transitions from an inactive state. (i.e., logic low) to an active state (i.e., logic high). The third driving signal also transitions from an inactive state to an active state after the first driving signal transitions from an active state to an inactive state. During the first and the second overlapping durations, the first and the third driving signals are both in inactive states. The fourth output of the controller provides a fourth driving signal (Dout) that substantially follows the second driving signal with opposite states and transition overlaps. A graph 604 shows the fourth driving signal. In one embodiment, the fourth driving signal controls the fourth power transistor 306 which is shown as a PFET with logic low corresponding to active states. With opposite states, the second power transistor 302 and the fourth power transistor 306 are alternately on. With transition overlaps, the fourth power transistor 306 turns off before the second power transistor 302 turns on and the fourth power transistor 306 turns on after the second power transistor 302 turns off. The graph 604 shows the fourth driving signal with periodic inactive states that exceed the first duration (e.g., from times T 4 -T 7 and T 12 -T 15 ). Thus, the fourth driving signal is substantially similar to the second driving signal except the leading edge of the fourth driving signal precedes the leading edge of the second driving signal by a third overlapping duration and the trailing edge of the fourth driving signal succeeds the trailing edge of the second driving signal after a fourth overlapping duration. In other words, the fourth driving signal transitions from an active state (i.e., logic low) to an inactive state (i.e., logic high) before the second driving signal transitions from an inactive state (i.e., logic low) to an active state (i.e., logic high). The fourth driving signal also transitions from an inactive state to an active state after the second driving signal transitions from an active state to an inactive state. During the third and the fourth overlapping durations, the second and the fourth driving signals are both in inactive states. FIG. 6 shows the four overlapping durations to have substantially identical time lengths (i.e., To). However, each of the overlapping durations can be a different time length. Referring to FIG. 6 in conjunction with FIGS. 5( a )- 5 ( h ), the period of overlapping active states between the first and the fourth driving signals (e.g., from time T 1 -T 2 or T 9 -T 10 ) corresponds to the first conduction state shown in FIG. 5( a ). The trailing edge transition overlaps between the first and the third driving signals (e.g., from times T 2 -T 3 and T 10 -T 11 ) correspond to the first transition state shown in FIG. 5( b ). The first period of overlapping inactive states (or first rest period) between the first and the second driving signals (e.g., from time T 3 -T 4 or T 11 -T 12 ) corresponds to the first idle state shown in FIG. 5( c ). The leading edge transition overlaps between the second and the fourth driving signals (e.g., from times T 4 -T 5 and T 12 -T 13 ) correspond to the second transition state shown in FIG. 5( d ). The period of overlapping active states between the second and the third driving signals (e.g., from time T 5 -T 6 or T 13 -T 14 ) corresponds to the second conduction state shown in FIG. 5( e ). The trailing edge transition overlaps between the second and the fourth driving signals (e.g., from times T 6 -T 7 and T 14 -T 15 ) correspond to the third transition state shown in FIG. 5( f ). The second period of overlapping inactive states (or second rest period) between the first and the second driving signals (e.g., from time T 7 -T 8 ) corresponds to the second idle state shown in FIG. 5( g ). Finally, the leading edge transition overlaps between the first and the third driving signals (e.g., from times T 0 -T 1 and T 8 -T 9 ) correspond to the fourth transition state shown in FIG. 5( h ). As discussed above, power is drawn from the power source and delivered to the lamp load 310 through the transformer 308 during the first and the second conduction states (or power-on states). No net current flows out of the power source during the first and the second idle states (or power-off states). In addition to facilitating power efficiency by reduced-voltage switching, the four transition states help avoid shoot-through current associated with the first power transistor 300 and the third power transistor 304 (or the second power transistor 302 and the fourth power transistor 306 ) being on at substantially the same time. The duration of the transition states (or transition overlaps) are chosen to guarantee that one of the power transistors is turned off before the other power transistor is turned on. FIG. 7 illustrates one embodiment of a controller circuit for generating the driving waveforms shown in FIG. 6 . The controller circuit of FIG. 7 accepts two input signals (A, B) with overlapping logic low levels (or inactive states) and generates four driving signals (Aout, Bout, Cout, Dout). For example, the two input signals are substantially similar to the driving signals shown in FIG. 2 for driving a half-bridge switching network. The first and the second driving signals (Aout, Bout) also have overlapping logic low levels (or inactive states). In one embodiment, a first delay circuit 700 and a second delay circuit 702 are coupled in series to the first input signal (A) to generate the first driving signal (Aout) and the third driving signal (Cout). For example, the first delay circuit 700 receives the first input signal and delays the first input signal by a first time delay (To( 1 )) to generate the first driving signal. The second delay circuit 702 receives the first driving signal and adds a second time delay (To( 2 )) to generate a first twice-delayed signal (A_delay). The first twice-delayed signal and the first input signal are provided to a first logic OR circuit (or gate) 708 to generate the third driving signal. In a similar configuration, a third delay circuit 704 and a fourth delay circuit 706 are coupled in series to the second input signal (B) to generate the second driving signal (Bout) and the fourth driving signal (Dout). For example, the third delay circuit 704 receives the second input signal and delays the second input signal by a third time delay (To( 3 )) to generate the second driving signal. The fourth delay circuit 706 receives the second driving signal and adds a fourth time delay (To( 4 )) to generate a second twice-delayed signal (B_delay). The second twice-delayed signal and the second input signal are provided to a second logic OR circuit 710 to generate the fourth driving signal. The time delays for the respective delay circuits 700 , 702 , 704 , 706 can be substantially identical or different. FIG. 8 is a timing diagram for some signals in the controller circuit of FIG. 7 . A graph 800 shows the first input signal (A) with respect to time. A graph 802 shows the first driving signal (Aout) with respect to time. A graph 804 shows the first twice-delayed signal (A_delay) with respect to time. Finally, a graph 806 shows the third driving signal (Cout) with respect to time. The first input signal has periodic active states or periods of logic high levels (e.g., from times T 0 -T 3 and T 6 -T 9 ). The first driving signal substantially follows the first input signal with leading and trailing edge transitions delayed by the first time delay (To( 1 )). The first twice-delayed signal substantially follows the first driving signal with leading and trailing edge transitions further delayed by the second time delay (To( 2 )). The third driving signal has leading edge transitions follow the leading edge transitions of the first input signal and trailing edge transitions follow the trailing edge transitions of the first twice-delayed signal. Thus, the third driving signal has leading edge transitions that precede the leading edge transitions of the first driving signal by the first time delay and trailing edge transitions that succeed the trailing edge transitions of the first driving signal by the second time delay. One possible disadvantage of the controller circuit shown in FIG. 7 is limited duty cycle for the driving signals. The pulse width of the input signals cannot be shorter than any of the time delays. In other words, duration of conduction states (e.g., logic high periods for the first driving signal) cannot be shorter than duration of transition states (e.g., delay in edge transitions between the first and the third driving signals or time delays of the delay circuits 700 , 702 , 704 , 706 ). FIG. 9 illustrates another embodiment of a controller circuit for generating the driving waveforms shown in FIG. 6 . The circuit implementation of FIG. 9 advantageously allows the duration of the conduction states to be shorter than the durations of the transition states. A first delay circuit 900 and a second delay circuit 902 are coupled in series to a first input signal (A) to generate a first driving signal (Aout) and a third driving signal (Cout). For example, the first delay circuit 900 receives the first input signal and adds a first time delay (To( 1 )) to generate the first driving signal. The second delay circuit 902 receives an output of the first delay circuit 900 and adds a second time delay (To( 2 )) to generate a first twice-delayed signal (A_delay). The first twice-delayed signal is provided to a first one-shot circuit (e.g., a falling edge-triggered monostable circuit) 908 . An output of the first one-short circuit 908 is provided to a reset terminal of a first SR latch 912 . The first input signal is provided to a set terminal of the first SR latch 912 . The first SR latch 912 outputs the third driving signal (e.g., at its Q output). In a similar configuration, a third delay circuit 904 and a fourth delay circuit 906 are coupled in series to a second input signal (B) to generate a second driving signal (Bout) and a fourth driving signal (Dout). For example, the third delay circuit 904 receives the second input signal and adds a third time delay (To( 3 )) to generate the second driving signal. The fourth delay circuit 906 receives an output of the third delay circuit 904 and adds a fourth time delay (To( 4 )) to generate a second twice-delayed signal (B_delay). The second twice-delayed signal is provided to a second one-shot circuit 910 . An output of the second one-shot circuit 910 is provided to a reset terminal of a second SR latch 914 . The second input signal is provided to a set terminal of the second SR latch 914 . The second SR latch 914 outputs the fourth driving signal. FIG. 10 is a timing diagram for some signals in the controller circuit of FIG. 9 . A graph 1000 shows the first input signal (A) with respect to time. A graph 1002 shows the first driving signal (Aout) with respect to time. A graph 1004 shows the first twice-delayed signal with respect to time. Finally, a graph 1006 shows the third driving signal (Cout) with respect to time. The first input signal has periodic durations of logic high levels (e.g., from times T 0 -T 1 and T 6 -T 7 ). The first driving signal substantially follows the first input signal with rising and falling edge transitions delayed by the first time delay (To(l)). The first twice-delayed signal substantially follows the first driving signal with rising and falling edge transitions further delayed by the second time delay (To( 2 )). In the timing diagrams shown in FIG. 10 , the logic high duration of the first input signal is less than the duration of the first time delay or the second time delay. The rising edge of the first input signal sets the rising edge of the third driving signal and the first SR latch 912 holds the logic high level of the third driving signal until the falling edge of the first twice-delayed signal resets the first SR latch 912 using the first one-shot circuit 908 . Thus, similar to the circuit implementation of FIG. 7 , the third driving signal has rising edge transitions that precede the rising edge transitions of the first driving signal by the first time delay and falling edge transitions that succeed the falling edge transitions of the first driving signal by the second time delay. However, unlike the circuit implementation of FIG. 7 , the circuit implementation of FIG. 9 does not have a duty cycle limitation. FIGS. 11( a )- 11 ( h ) illustrate another embodiment of a periodic timing sequence for a full-bridge switching network that further improves power efficiency. FIGS. 11( a )- 11 ( h ) are substantially similar to FIGS. 5( a )- 5 ( h ) with exception of the idle states shown in FIGS. 5( c ) and 5 ( g ). As described above, no net current flows out of the power source during the idle (or power-off) states. However, current is flowing through the primary winding of the transformer 308 and power continues to be delivered to the lamp load 310 . The power delivered to the lamp load 310 during the power-off states comes from energy stored in the leakage inductance of the transformer 308 . During the power-off states, power efficiency is limited by the on-resistance of conducting transistors. The conducting transistors in FIGS. 5( c ) and 5 ( g ) are the third and the fourth power transistors 304 , 306 , which are PFETs. It is often easier and cheaper to find NFETs with lower on-resistance than PFETs. FIGS. 11( a )- 11 ( h ) shows the periodic timing sequence in which the first and the second power transistors (e.g., NFETs) 300 , 302 are on during the power-off states to further improve power efficiency. For example, FIG. 11( a ) illustrates a first conduction state in which the first transistor (QA) 300 and the fourth power transistor (QD) 306 are on while the second transistor (QB) 302 and the third power transistor (QC) 304 are off to allow power to flow from the power source (VP) to the lamp load 310 in a first polarity. For example, current flows from the power source through the fourth power transistor 306 , through the primary winding of the transformer 308 and through the first power transistor 300 to ground during the first conduction state. FIGS. 11( b )- 11 ( d ) illustrate intermediate steps to transition from the first conduction state to a second conduction state illustrated in FIG. 11( e ). FIG. 11( b ) shows a first transition state, following the first conduction state, in which the fourth power transistor 306 turns off. Because of leakage inductance associated with the transformer 308 , the current through the primary winding of the transformer 308 does not stop instantaneously. The current flowing through the primary winding of the transformer 308 finds a path to ground through a body diode 502 of the second power transistor 302 . The body diode 502 has a cathode coupled to the second terminal of the primary winding and an anode coupled to ground. With the body diode 502 conducting, the source-to-drain voltage of the second power transistor 302 is relatively low (e.g., approximately 0.7 volt or one diode voltage drop). FIG. 11( c ) shows a first idle state, following the first transition state, in which the second power transistor 302 turns on. FIG. 11( d ) shows a second transition state, following the first idle state, in which the first power transistor 300 turns off. Similar to the first transition step, the current flowing through the primary winding of the transformer 308 does not stop abruptly. The current flowing through the primary winding of the transformer 308 finds a path through a body diode 500 of the third power transistor 304 back to the power source. The body diode 500 has a cathode coupled to the power source and an anode coupled to the first terminal of the primary winding. FIG. 11( e ) shows the second conduction state, following the second transition state, in which the third power transistor 304 turns on to allow power to flow from the power source to the lamp load 310 in a second polarity. The third power transistor 302 turns on after its body diode 500 starts conducting to take advantage of reduced-voltage switching. In the second conductions state, current flows from the power source through the third power transistor 304 , through the primary winding of the transformer 308 and through the second power transistor 302 to ground. The current flows in opposite directions through the primary winding of the transformer 308 between the first and the second conduction states. FIGS. 11( f )- 11 ( h ) illustrate another set of intermediate steps, following the same principles shown in FIGS. 11( b )- 11 ( d ), to transition from the second conduction state back to the first conduction state. For example, FIG. 11( f ) shows a third transition state, following the second conduction state, in which the third power transistor 304 turns off and the current flowing the primary winding of the transformer 308 finds a path to ground through a body diode 506 of the first power transistor 300 . The body diode 506 has a cathode coupled to the first terminal of the primary winding and an anode coupled to ground. FIG. 11( g ) shows a second idle state, following the third transition state, in which the first power transistor 300 turns on using zero-voltage switching. Thus, NFETs with relatively lower on-resistance are conducting during the first and the second idle states. FIG. 11( h ) shows a fourth transition state, following the second idle state, in which the second power transistor 302 turns off and the current flowing through the primary winding of the transformer 308 finds a path to the power source through a body diode 504 of the fourth power transistor 306 . The body diode 504 has a cathode coupled to the power source and an anode coupled to the second terminal of the primary winding. The fourth power transistor 306 turns on using zero-voltage switching in the next step of the periodic timing sequence to return to the first conduction state. FIG. 12 illustrates one embodiment of driving waveforms to control transistors in a full-bridge switching network in accordance with the periodic timing sequence depicted in FIGS. 11( a )- 11 ( h ). For example, a controller outputs four driving signals to flexibly drive either a half-bridge or a full-bridge switching network using a reduced-voltage (or zero-voltage) switching technique. A graph 1200 shows a first driving signal (Aout) with respect to time. A graph 1202 shows a second driving signal (Bout) with respect to time. A graph 1204 shows a fourth driving signal (Dout) with respect to time. Finally a graph 1206 shows a third driving signal (Cout) with respect to time. The driving signals shown in FIG. 12 are substantially similar to the driving signals shown in FIG. 6 except the first and the second driving signals have overlapping active states (e.g., from times T 3 -T 4 , T 7 -T 8 and T 11 -T 12 ) while the third and the fourth driving signals have overlapping inactive states to allow the first and the second power transistors (NFETs) 300 , 302 to conduct during the idle states. The first and the second driving signals have substantially identical active and inactive durations phase-shifted by approximately 180°. The third and the first driving signals have tracking logic levels (or opposite states) and transition overlaps. That is, the leading edges of the third driving signal precedes the respective leading edges of the first driving signal by a first overlap duration (e.g., from time T 6 -T 7 or T 14 -T 15 ) and the trailing edges of the third driving signal succeeds the respective trailing edges of the first driving signal by a second overlap duration (e.g., from time T 4 -T 5 or T 12 -T 13 ). The second and the fourth driving signals also have tracking logic levels and transition overlaps. That is, the leading edges of the fourth driving signal precedes the respective leading edges of the second driving signal by a third overlap duration (e.g., from time T 2 -T 3 or T 10 -T 11 ) and the trailing edges of the fourth driving signal succeeds the respective trailing edges of the second driving signal by a fourth overlap duration (e.g., from time T 0 -T 1 or T 8 -T 9 ). FIG. 13 illustrates one embodiment of a controller circuit for generating the driving waveforms shown in FIG. 12 . The controller circuit of FIG. 13 accepts two input signals (A, B) with overlapping logic low levels and generates four driving signals (Aout, Bout, Cout, Dout). In one embodiment, the two input signals are substantially similar to driving signals for driving a half-bridge switching network. The first and the second driving signals (Aout, Bout) have overlapping logic high levels (or active states) in the controller circuit of FIG. 13 . In one embodiment, a first delay circuit 1300 and a second delay circuit 1302 are coupled in series to the first input signal (A) to generate the second driving signal (Bout) and the fourth driving signal (Dout). For example, the first delay circuit 1300 receives the first input signal and delays the first input signal by a first time delay. A first inverter 1308 is coupled to an output of the first delay circuit 1300 to generate the fourth driving signal. The second delay circuit 1302 is coupled to the output of first delay circuit 1300 and adds a second time delay to generate a first twice-delayed signal. The first twice-delayed signal and the first input signal are provided to a first logic NOR circuit (or gate) 1310 to generate the second driving signal. In a similar configuration, a third delay circuit 1304 and a fourth delay circuit 1306 are coupled in series to the second input signal (B) to generate the first driving signal (Aout) and the third driving signal (Cout). For example, the third delay circuit 1304 receives the second input signal and delays the second input signal by a third time delay. A second inverter 1312 is coupled to an output of the third delay circuit 1304 to generate the third driving signal. The fourth delay circuit 1306 is coupled to the output of the third delay circuit 1304 and adds a fourth time delay to generate a second twice-delayed signal. The second twice-delayed signal and the second input signal are provided to a second logic NOR circuit 1314 to generate the first driving signal. The time delays for the respective delay circuits 1300 , 1302 , 1304 , 1306 can be substantially identical (e.g., To) or different. FIG. 14 illustrates another embodiment of a controller circuit for generating the driving waveforms shown in FIG. 12 . A first delay circuit 1400 and a second delay circuit 1402 are coupled in series to a first input signal (A) to generate a second driving signal (Bout) and a fourth driving signal (Dout). For example, the first delay circuit 1400 receives the first input signal and adds a first time delay. A first inverter is coupled to an output of the first delay circuit 1400 to generate the fourth driving signal. The second delay circuit 1402 receives the output of the first delay circuit 1400 and adds a second time delay to generate a first twice-delayed signal. The first twice-delayed signal is provided to a first one-shot circuit 1410 . An output of the first one-short circuit 1410 is provided to a reset terminal of a first latch 1412 . The first input signal is provided to a set terminal of the first latch 1412 . The first latch 1412 outputs the second driving signal (e.g., at its QB output). In a similar configuration, a third delay circuit 1404 and a fourth delay circuit 1406 are coupled in series to a second input signal (B) to generate a first driving signal (Aout) and a third driving signal (Cout). For example, the third delay circuit 1404 receives the second input signal and adds a third time delay. A second inverter 1414 is coupled to an output of the third delay circuit 1404 to generate the third driving signal. The fourth delay circuit 1406 receives the output of the third delay circuit 1404 and adds a fourth time delay to generate a second twice-delayed signal. The second twice-delayed signal is provided to a second one-shot circuit 1416 . An output of the second one-shot circuit 1416 is provided to a reset terminal of a second latch 1418 . The second input signal is provided to a set terminal of the second latch 1418 . The second latch 1418 outputs the first driving signal. The circuit implementation of FIG. 14 advantageously has no limitation on the duty cycle of the driving signals. Various embodiments have been described above. Although described with reference to these specific embodiments, the descriptions are intended to be illustrative and are not intended to be limiting. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.

A driver circuit or controller flexibly drives either a half-bridge or a full-bridge switching network in a backlight inverter without modification, redundant circuitry or additional components. The driver circuit includes four outputs to provide four respective driving signals that establish a periodic timing sequence using a zero-voltage switching technique for semiconductor switches in the switching network.

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation of U.S. patent application Ser. No. 09/778,265, filed Feb. 7, 2001, now U.S. Pat. No. 6,506,252 the disclosure of which is incorporated herein by reference in its entirety, and U.S. patent application Ser. No. 10/268,464 filed on Oct. 10, 2002, now U.S. Pat. No. 6,685,774 the disclosure of which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION The present invention relates to making semiconductor components and more particularly relates to devices for growing epitaxial layers on substrates, such as wafers. BACKGROUND OF THE INVENTION Various industries employ processes to form thin layers on solid substrates. The substrates having deposited thin layers are widely used in microprocessors, electro-optical devices, communication devices and others. The processes for the deposition of the thin layers on solid substrates are especially important for the semiconductor industry. In the manufacturing of semiconductors, the coated solid substrates, such as substantially planar wafers made of silicon and silicon carbide, are used to produce semiconductor devices. After the deposition, the coated wafers are subjected to well-known further processes to form semiconductor devices such as lasers, transistors, light emitting diodes, and a variety of other devices. For example, in the production of the light-emitting diodes, the layers deposited on the wafer form the active elements of the diodes. The materials deposited on the solid substrates include silicon carbide, gallium arsenide, complex metal oxides (e.g., YBa 2 Cu 3 O 7 ) and many others. The thin films of inorganic materials are typically deposited by the processes collectively known as chemical vapor deposition (CVD). It is known that the CVD processes, if properly controlled, produce thin films having organized crystal lattices. Especially important are the deposited thin films having the same crystal lattice structures as the underlying solid substrates. The layers by which such thin films grow are called the epitaxial layers. In a typical chemical vapor deposition process, the substrate, usually a wafer, is exposed to gases inside a CVD reactor. Reactant chemicals carried by the gases are introduced over the wafer in controlled quantities and at controlled rates while the wafer is heated and usually rotated. The reactant chemicals, commonly referred to as precursors, are introduced into the CVD reactor by placing the reactant chemicals in a device known as a bubbler and then passing a carrier gas through the bubbler. The carrier gas picks up the molecules of the precursors to provide a reactant gas that is then fed into a reaction chamber of the CVD reactor. The precursors typically consist of inorganic components, which later form the epitaxial layers on the surface of the wafer (e.g., Si, Y, Nb, etc.), and organic components. Usually, the organic components are used to allow the volatilization of the precursors in the bubbler. While the inorganic components are stable to the high temperatures inside the CVD reactor, the organic components readily decompose upon heating to a sufficiently high temperature. When the reactant gas reaches the vicinity of a heated wafer, the organic components decompose, depositing the inorganic components on the surface of the wafer in the form of the epitaxial layers. CVD reactors have various designs, including horizontal reactors in which wafers are mounted at an angle to the inflowing reactant gases; horizontal reactors with planetary rotation in which the reactant gases pass across the wafers; barrel reactors; and vertical reactors in which wafers are rotated at a relatively high speed within the reaction chamber as reactant gases are injected downwardly onto the wafers. The vertical reactors with high-speed rotation are among the most commercially important CVD reactors. Among the desirable characteristics for any CVD reactor are heating uniformity, low reactor cycle time, good performance characteristics, longevity of the internal parts that are heated and/or rotated inside the reaction chamber, ease of temperature control and high temperature tolerance for component parts. Also important are the cost of the required component parts, ease of maintenance, energy efficiency and minimization of the heating assembly's thermal inertia. For example, if the heated components of a CVD reactor have high thermal inertia, certain reactor operations may be delayed until the heated components reach the desired temperatures. Therefore, lower thermal inertia of the heated components of the reactor increases the productivity since the throughput depends upon the reactor cycle time. Similarly, if the internal parts of the reactor that are rotated during the deposition undergo even a small degree of deformation, the reactor may exhibit excessive vibration during use, resulting in heightened maintenance requirements. A typical prior art vertical CVD reactor is illustrated in FIG. 1 . As seen from FIG. 1, a wafer 10 is placed on a wafer carrier 12 , which is placed on a susceptor 14 . The wafer carrier 12 is usually made from a material that is relatively inexpensive and allows good manufacturing reproducibility. The wafer carrier may have to be replaced after a certain commercially suitable number of reactor cycles. The susceptor 14 is permanently mounted and supported by a rotatable spindle 16 , which enables rotation of the susceptor 14 , the wafer carrier 12 and the wafer 10 . The susceptor 14 , the wafer carrier 12 and the wafer 10 are located in an enclosed reactor chamber 18 . A heating assembly 20 , which may include one or more heating filaments 22 , is arranged below the susceptor 14 , and heated by passing an electric current through electrodes 25 . The heating assembly 20 heats the susceptor 14 , the wafer carrier 12 and, ultimately, the wafer 10 . The rotation of the wafer carrier 12 is intended to enhance the temperature uniformity across the deposition area, as well as the uniformity of the reactant gas introduced over the wafer 10 during the deposition. As the wafer-supporting assembly (spindle/susceptor/wafer carrier) rotates the heated wafer 10 , the reactant gas is introduced into the reaction chamber 18 , depositing a film on the surface of the wafer 10 . The vertical CVD reactors having both the susceptor and the wafer carrier, similar to the reactor shown in FIG. 1, enjoy a widespread and successful use for a variety of CVD applications. For example, the Enterprise and Discovery reactors, made by Emcore Corporation of Somerset, N.J., are some of the most successful CVD reactors in the commercial marketplace. However, as discovered by the inventors of the present invention, the performance of such CVD reactors may be further improved for certain CVD applications. First, the CVD reactor having both a susceptor and a wafer carrier contains at least two thermal interfaces. Referring to FIG. 1, these are the interfaces between the heating assembly 20 and the susceptor 14 , and between the susceptor 14 and the wafer carrier 12 . Research by the inventors of the present invention has shown that a substantial temperature gradient exists at these interfaces. For example, the temperature of the heating assembly 20 is higher than the temperature of the susceptor 14 , which, in turn, is higher than the temperature of the wafer carrier 12 . Consequently, the heating assembly 20 must be heated to a substantially higher temperature than the temperature desired for the wafer 10 during the deposition. The required higher temperatures of the heating assembly lead to higher energy consumption and faster deterioration of the heating assembly's components. In addition, the typical susceptor possesses a significant heat capacity, and thus a large thermal inertia, substantially increasing the time required to heat and cool down the wafer carrier 12 . This results in a longer reactor cycle and consequent reduction in the productivity of the reactor. Also, the inventors have determined that the longer reactor cycle time tends to result in a less precise and less flexible control of the wafer carrier's temperature, increasing the time necessary to stabilize the temperature of the wafer carrier prior to the deposition. Second, in the CVD reactors similar to the reactor of FIG. 1, the susceptor 14 must withstand a large number of reactor cycles since it is permanently mounted in the reaction chamber, and typically may not be easily replaced without interrupting the reactor cycle, opening up the reactor and removing the parts that permanently attach the susceptor to the spindle, such as screws, bolts and the like. Therefore, the susceptors are usually made from highly temperature- and deformation-resistant materials, typically molybdenum. Such materials are very expensive and often exhibit a high thermal inertia. Third, every additional interface in the wafer-supporting assembly increases the manufacturing tolerance requirements. For example, again with reference to FIG. 1, the spacing between the susceptor 14 and the wafer carrier 12 must be precise and uniform to produce the required uniform heating of the wafer. However, notwithstanding the high precision machining used in the manufacturing of the susceptors, the susceptor/wafer carrier spacing is likely to exhibit some non-uniformity due to both the over-the-time deformation of the susceptor and a certain unavoidable degree of deviation in the susceptor-to-susceptor manufacturing reproducibility. Further, a small degree of deformation of the susceptor is essentially unavoidable in the CVD reactors having both the susceptor and the wafer carrier due to the required non-uniform heating of the susceptor to produce the uniform heating of the wafer carrier. The accumulated deformation of the susceptor eventually may lead to an excessive vibration of the wafer-supporting assembly during rotation in the deposition process, and the resulting loss and destruction of coated wafers. Fourth, in the CVD reactors with permanently mounted susceptors, the susceptor is typically rigidly attached to the spindle to minimize the vibration during the operation of the reactor. The spindle/susceptor connection is heated during the repeated operation of the reactor and sometimes becomes difficult to disassemble, complicating the maintenance and the replacement procedures. Finally, the heavier is the wafer-supporting assembly, the larger is the mechanical inertia of the spindle. In turn, the high mechanical inertia increases the strain on the spindle-supporting assembly, reducing its lifetime. Notwithstanding these limitations, the existing prior art CVD reactors having both a susceptor and a wafer carrier continue enjoying a successful and widespread use in the semiconductor industry. Nevertheless, there exists a need for a CVD reactor that minimizes these limitations of the presently available CVD reactors while maintaining a high level of performance. SUMMARY OF THE INVENTION The present invention addresses this need by providing a novel CVD reactor in which the wafer carrier is placed on the rotatable spindle without a susceptor, and a related method of growing epitaxial layers in a CVD reactor. These novel reactors are likely to be used along with the presently available successful CVD reactors, such as the reactor shown in FIG. 1 . It has been determined by the inventors that, in the prior art CVD reactors, for example, the prior art reactor shown in FIG. 1, substantial thermal losses occur at thermal interfaces in the wafer-supporting assembly. The research by the inventors also has shown that the increase in the temperature of the heating filament required to achieve the desired wafer temperature significantly reduces the lifetime of the heating filaments. It has also been determined by the inventors that the presence of a permanently mounted susceptor in the prior art CVD reactors makes a significant contribution to the overall thermal and mechanical inertia of the wafer-supporting assembly. The inventors have also determined that the rotatable spindle is a source of a substantial heat drain from the wafer-supporting assembly during the deposition. This heat drain may negatively affect the heating uniformity, the energy efficiency and the lifetime of the heating filaments. Therefore, the present invention provides a novel CVD reactor, use of which minimizes these limitations of the presently available CVD reactors, as well as the limitations described in the Background section herein. According to one aspect of the invention, an apparatus for growing epitaxial layers on one or more wafers by chemical wafer deposition is provided, and includes a reaction chamber, a rotatable spindle, a heating means for heating the wafers and a wafer carrier for supporting and transporting the wafers between a deposition position and a loading position. In the loading position, the wafer carrier is separated from the rotatable spindle and the wafers may be placed on the wafer carrier for subsequent transfer to the deposition position. The loading position may be located inside the reaction chamber or outside the reaction chamber. Preferably, the loading position is located outside the reaction chamber. There may be one or more of such loading positions. In the deposition position, the wafer carrier is detachably mounted on the rotatable spindle inside the reaction chamber, permitting chemical vapor deposition of the wafers placed on the wafer carrier. Preferably, in the deposition position, the wafer carrier is in direct contact with the spindle. Also, preferably, when in the deposition position, the wafer carrier is centrally mounted onto the spindle and supported only by the spindle. Most preferably, the wafer carrier is retained on the spindle by the force of friction, meaning that there exist no separate retaining means for retaining the wafer carrier on the spindle in the deposition position. However, the apparatus of the present invention may also include a separate retaining means for retaining the wafer carrier in the deposition position. The separate retaining means may be integral with the rotatable spindle or separate from both the spindle and the wafer carrier. The wafer carrier of the invention may include a top surface and a bottom surface. The top surface of the wafer carrier may include one or more cavities for placing the wafers. The bottom surface may include a central recess for detachably mounting the wafer carrier onto the spindle. The central recess extends from the bottom surface of the wafer carrier toward the top surface of the wafer carrier to a recess end point. Preferably, the central recess does not reach the top surface of the wafer carrier and therefore the recess end point lies at a lower elevation than the top surface of the wafer carrier. The rotatable spindle includes an upper end for mounting the wafer carrier inside the reaction chamber. In the deposition position, the upper end of the spindle is inserted into the central recess of the bottom surface of the wafer carrier. Preferably, to improve the rotational stability of the wafer carrier, the spindle supports the wafer carrier above the wafer carrier's center of gravity. The apparatus of the invention may also include a mechanical means for transporting the wafer carrier between the deposition position and the loading position. The heating means of the apparatus of the invention may include one or more radiant heating elements. The apparatus of the invention may be used to process a single wafer or a plurality of wafers. According to another aspect of the present invention, an apparatus for growing epitaxial layers on one or more wafers by chemical vapor deposition is provided; the apparatus including a reaction chamber, a rotatable spindle having an upper end located inside the reaction chamber, a wafer carrier and a radiant heating element disposed under the wafer carrier. The wafer carrier provides a support and transports the wafers. During the deposition, the wafer carrier is centrally and detachably mounted on the upper end of the spindle, where it is in a contact with the spindle. The wafer carrier is mounted in a manner that allows it to be readily removed from the upper end of the spindle. After the deposition is complete or at any other time, the wafer carrier may be removed from the upper end of the spindle and transported to a position for loading or unloading wafers. There may be one or a plurality of such loading positions. The loading position may be located inside the reaction chamber or outside the reaction chamber. Preferably, the wafer carrier is in a direct contact with the upper end of the spindle and has a top surface that includes one or a plurality of cavities for supporting a plurality of wafers. Therefore, either a single wafer or a plurality of wafers may be deposited in the reactor of the invention at the same time. The wafer carrier is transported between the position mounted onto the upper end of the spindle and the loading position by mechanical means, typically a robotic arm. In a preferred embodiment of this aspect of the invention, the bottom surface of the wafer carrier includes a central recess, which extends upward from the bottom surface in a direction of the top surface of the wafer carrier, terminating in a recess end point. The central recess does not reach the top surface of the wafer carrier. Therefore, the recess end point is located at a lower elevation than the top surface of the wafer carrier. When the wafer carrier is mounted onto the upper end of the spindle, the upper end of the spindle is inserted into the central recess in the bottom surface of the wafer carrier. The insertion provides a point of conduct between the spindle and the wafer carrier, allowing the wafer carrier to be supported by the spindle. To improve the rotational stability of the wafer carrier, the point of contact between the spindle and the wafer carrier having the highest elevation is located above the center of gravity of the wafer carrier. In the most preferred embodiment of this aspect of the invention, the wafer carrier has a substantially round shape. In this embodiment, the top surface and the bottom surface of the wafer carrier are substantially parallel to each other. Of course, the top surface of the wafer carrier may include cavities for placing the wafers, and the bottom surface of the wafer carrier includes a recess for mounting the wafer carrier onto the upper end of the spindle, and other indentations or raised features are not excluded on either the top surface or the bottom surface of the wafer carrier. The spindle according to this embodiment of the invention has a substantially cylindrical shape and an axis of rotation. The bottom surface of the wafer carrier, when mounted on the spindle, is substantially perpendicular to the axis of rotation of the spindle. The upper end of the spindle preferably terminates in a substantially flat top surface, which is also substantially perpendicular to the axis of rotation of the spindle. Preferably, the upper end of the spindle narrows toward the substantially flat top surface of the spindle. Therefore, the narrow portion of the upper end of the spindle is located near the substantially flat top surface of the spindle, and the wide portion of the spindle is located distal from the substantially flat top surface of the spindle. As has been stated, the spindle is a source of a significant heat drain from the wafer-supporting assembly. The present invention provides the novel way of reducing this heat drain. To this end, in a preferred embodiment, the spindle has a cavity extending vertically downward from the substantially flat top surface of the upper end of the spindle to a cavity end point, which is disposed at a predetermined depth. The cavity in the spindle has a substantially cylindrical shape and is substantially coaxial with the spindle. The predetermined depth of the cavity in the spindle is preferably from about 3 to about 4 spindle diameters. This hollow construction of the upper end of the spindle allows the reduction of the heat drain from the wafer-supporting assembly. To further reduce the heat drain, a specific arrangement of the radiant heating elements is provided. In this arrangement, the radiant heating element includes a first radiant heating element that is substantially coaxial with the rotatable spindle and has a top surface proximal to the bottom surface of the wafer carrier, an internal circumference and an external circumference. The internal circumference of the first radiant heating element defines a round opening around the spindle. This arrangement of the radiant heating elements of the invention may also include a second radiant heating element substantially coaxial with the first radiant heating element and the spindle, and located between the first radiant heating element and the spindle. The second radiant heating element defines an external circumference, the radius of which is smaller than the radius of the internal circumference of the first radiant heating element. Most preferably, the top surface of the second radiant heating element is located at substantially the same elevation as the top surface of the first radiant heating element, and the bottom surface of the second radiant heating element is located at the same elevation as the cavity end point of the rotatable spindle. The second radiant heating element allows heating of the upper end of the spindle, which along with the hollow construction of the upper end of the spindle reduces the heat drain from the wafer-supporting assembly. The reactor of the invention may also include a radiant heating shield. According to yet another aspect of the invention, a method of growing epitaxial layers on one or more wafers by chemical wafer deposition is provided. According to the method of the invention, the chemical wafer deposition is carried out in a reactor chamber that includes a rotatable spindle having an upper end disposed inside the reaction chamber. To carry out the deposition, the method includes a) providing a wafer carrier having a surface for retaining one or more wafers; b) placing one or more wafers on the surface of the wafer carrier in a loading position, in which the wafer carrier is separated from the spindle; c) transporting the wafer carrier towards the spindle; d) detachably mounting the wafer carrier on the upper end of the spindle for rotation therewith; and e) rotating the spindle and the wafer carrier located thereon while introducing one or more reactants to the reaction chamber and heating the wafer carrier. Preferably, the method of the invention further includes removing the wafer carrier from the upper end of the spindle to unload the wafers. The step of detachably mounting the wafer carrier may include directly mounting the wafer carrier, and/or centrally mounting the wafer carrier on the upper end of the spindle. Preferably, the wafer carrier is mounted on the upper end of the spindle above the wafer carrier's center of gravity and retained therein only by a force of friction. Preferably, the loading position is located outside the reaction chamber. DESCRIPTION OF THE DRAWINGS A more accurate appreciation of the subject matter of the present invention and the various advantages thereof can be realized by reference to the following detailed description, which makes reference to the accompanying drawings in which: FIG. 1 is a highly schematic front cross-sectional view of a CVD reactor of the prior art; FIG. 2 is a highly schematic front cross-sectional view of a wafer-supporting assembly of the present invention, showing that the wafer carrier may be transported between the loading position and the deposition position, where it is placed on the spindle without a susceptor; FIGS. 3A and 3B are highly schematic views of an apparatus of the present invention, showing that the wafer carrier may be transferred between a loading position and a deposition position through a gate valve; FIG. 4 is a highly schematic diagram of the wafer-supporting assembly of the prior art, showing a susceptor permanently attached to the upper end of the spindle, the wafer carrier, the heating element and the radiant heating shield; FIG. 5A is a highly schematic front cross-sectional view of the wafer-supporting assembly of the present invention, showing the wafer carrier mounted on the upper end of the spindle in the deposition position; FIG. 5B is a top perspective view of the wafer carrier of the variant of the invention shown in FIG. 5A; FIG. 5C is a top perspective view of the wafer-supporting assembly of the variant of invention shown in FIGS. 5A and 5B, with the wafer carrier being in the loading position, in which the wafer carrier is removed from the spindle, showing the upper end of the spindle and the primary heating element; FIG. 5D is an elevated bottom view of the wafer carrier of the variant of the invention shown in FIGS. 5A-5C; FIG. 6A is a highly schematic front cross-sectional view of another variant of the invention; FIG. 6B is a top perspective top view of the spindle of the variant of the invention shown in FIG. 6A; FIG. 7A is a highly schematic cross-sectional view of the wafer-supporting assembly of another variant of the invention, showing a cavity in the upper end of the spindle for reducing the heat drain from the wafer-supporting assembly through the spindle; FIG. 7B is a top perspective view of an upper end of the spindle according to the variant shown in FIG. 7A; FIG. 7C is a highly schematic front cross-sectional view of the spindle of the variant of the invention shown in FIGS. 7A and 7B; FIG. 7D is a highly schematic front cross-sectional view of the relationship between the spindle and the wafer carrier of the variant of the invention shown in FIGS. 7A-7C; FIG. 8A is a highly schematic front cross-sectional view of the wafer-supporting assembly of the invention showing a novel arrangement of the spindle and the radiant heating elements, use of produces a decrease in the heat drain from the wafer-supporting assembly through the spindle; FIG. 8B is a top perspective top view of the wafer-supporting assembly of the invention, with the wafer carrier being in the loading position, showing the spindle/heating element arrangement for a variant of the invention shown in FIGS. 7A-7C; FIGS. 9A, 9 B and 9 C show possible variants of the retaining means of the invention for retaining the wafer carrier on the upper end of the spindle in the deposition position. DETAILED DESCRIPTION OF THE INVENTION The general concept of the invention is shown in FIG. 2 . The reactor of the invention includes a reaction chamber 100 , a wafer carrier 110 , a rotatable spindle 120 and heating means 170 . The wafer carrier 110 is transported between a loading position L and a deposition position D. In the position L, the wafer carrier 110 is separated from the spindle 120 . In the position D, the wafer carrier 110 is mounted on the rotatable spindle 120 . Preferably, the wafer carrier 110 is mounted on an upper end 180 of the spindle 120 . According to the invention, in position D, the wafer carrier is mounted in any manner that would allow it to be readily separated from the spindle 120 in the normal course of operating the reactor of the invention during the reactor cycle. Such manner of mounting the wafer carrier 110 excludes such means of attaching the wafer carrier 110 to the spindle 120 as screws, bolts and the like, the use of which would necessitate the opening of the reactor and the removal of such parts or pieces that would permanently attach the wafer carrier 110 to the spindle 120 . Preferably, in position D, the wafer carrier 110 is retained on the spindle 120 only by a force of friction, with no separate retaining means. In contrast to the prior art CVD reactor shown in FIG. 1, the reactor of the present invention does not include a susceptor. Preferably, the wafer carrier 110 is directly mounted onto the spindle 120 , i.e., in the position D, a direct contact is established between the wafer carrier 110 and the spindle 120 . The invention does not exclude the possibility that intermediate elements may be present between the spindle 120 and the wafer carrier 110 , for example the elements that would facilitate retaining the wafer carrier 110 on the spindle 120 , such as rings, retainers and the like, as long as these intermediate elements do not interfere with the removal or detachment of the wafer carrier from the position D in the normal course of the operation of the reactor. In the position L, wafers 130 are loaded onto the wafer carrier 110 prior to the transfer of the wafer carrier 110 and the wafer 130 to the reaction chamber 100 . The loading position L may be located inside or outside of the reaction chamber 100 . Although only one position L is shown in FIG. 2, there may be one or more such positions. The wafer carrier 110 may include a top surface 111 for placing wafers. The reactor of the invention may be used for coating a single wafer or a plurality of wafers. Accordingly, the top surface 111 of the wafer carrier 110 may be adopted either for a single wafer or a plurality of wafers in any manner known in the art. Preferably, the top surface 111 has a plurality of cavities for placing a plurality of wafers 130 . FIGS. 3A and 3B show an example of the transporting operation for the wafer carrier 110 . As can be seen with reference to FIG. 3A, the loading position L for the wafer carrier 110 is located in a separate loading chamber 150 that is connected to reaction chamber 100 by a gate valve 160 . The loading chamber 150 has an exhaust opening 108 that allows for separate ventilation of the loading chamber 150 without interrupting the reactor cycle. In position L, the wafer carrier 110 is loaded with uncoated wafers 130 . Thereafter, the wafer carrier 110 is transported through the gate valve 160 to the reaction chamber 100 . The reaction chamber 100 may include a top flange 104 and a bottom plate 102 . The spindle 120 is inserted through an opening in the base plate 102 so that the upper end 180 of the spindle 120 is inside the reaction chamber 100 . The spindle 120 may be connected to rotating means 109 , such as an electric motor. The reaction chamber 100 may also include an exhaust opening 106 and other elements known in the art. As shown in FIG. 3B, in the deposition position D, the wafer carrier 110 with uncoated wafers 130 is mounted on the upper end 180 of the spindle 120 , and may be rotated together with the spindle 120 during the operation of the reactor. The precursor chemicals then may be supplied to the reaction chamber 100 through the top flange 104 , while the wafer carrier 110 and the wafers 130 are rotated by the spindle 120 and heated by the heating means 140 . Preferably, only the spindle 120 supports the wafer carrier 110 in the position D. After the deposition is complete, the wafer carrier 110 is transported back to the position L to unload the coated wafers and to load new uncoated wafers for subsequent transfer to the position D in the reaction chamber 100 . This reactor cycle may be repeated to process a larger quantity of wafers. The wafer carrier 110 may be transported between the positions D and L in any manner known in the art. For example, the reactor of the invention may include a mechanical means for the transfer, for example, a robotic arm or an autoloader. For example, the suitable mechanical means for transferring the wafer carrier of the present invention is described in co-assigned U.S. Pat. No. 6,001,183, which is incorporated herein by reference in its entirety. Preferably, the wafer carrier 110 has a round or a rectangular shape; most preferably the wafer carrier 110 has a round shape. The wafer carrier may be made from any suitable material capable of withstanding the high temperatures inside the reaction chamber of the CVD reactor, such as graphite or molybdenum. Of course, cost considerations may affect the choice of the suitable material. The absence of the susceptor/wafer carrier interface, as explained above, broadens the choice of the suitable materials to include less expensive alternatives. The heating means 140 preferably include one or more radiant heating elements. Use of a plurality of radiant heating elements permits multi-zone heating of the wafer carrier 110 , better temperature control and coating uniformity. The radiant heating elements may be arranged in any manner known to those skilled in the art. The preferred arrangement will be shown with reference to the specific embodiments of he invention. The CVD reactor of the present invention has a number of important advantages. The absence of a permanently mounted susceptor reduces the thermal inertia of the wafer-supporting assembly, resulting in a reduction of the reactor cycle time and a better control over the wafer temperatures. Also, the elimination of one of the thermal interfaces present in the prior art reactors (i.e., heating element/susceptor interface) reduces the temperature gradient between the heating element or elements and the wafer, increasing the energy efficiency of the reactor and the lifetime of the heating elements. Further, the lower weight of the wafer-supporting assembly reduces its mechanical inertia and therefore the strain on the spindle. The elimination of the contact between the susceptor and the wafer carrier that requires high precision machining and still may exhibit some non-uniformity results in lower manufacturing tolerance requirements and better wafer-to-wafer temperature uniformity. For the same reasons, the wafer carrier of the present invention may be made of less expensive materials, reducing the overall cost of the reactor. Also, the possibility of the vibration of the wafer-supporting assembly is minimized due to the good rotational stability of the wafer carrier of the invention. For the same reasons, the lower vibration leads to lower losses of the coated wafers. These and other advantages of the invention will be explained with reference to the specific embodiments and variants of the invention. For the purpose of illustration, the present invention will be described with reference to the specific embodiments. It should be understood that these embodiments are not limiting and the present invention encompasses any subject matter that is within the scope of the appended claims. FIG. 4 shows a wafer-supporting assembly of the prior art. The susceptor 14 is permanently mounted onto the spindle 16 by screws 70 . During the deposition, the wafer carrier 12 is placed onto the susceptor 14 . The heating arrangement may include a primary heating element 25 and secondary heating elements 26 and 27 . As described above, the inventors have discovered that the presence of the susceptor 14 and the resulting heating element/susceptor and susceptor wafer carrier interfaces effect the performance of the reactor. Therefore, all embodiments of the reactor of the invention do not include a permanently mounted susceptor. FIGS. 5A, 5 B, 5 C and 5 D show a variant of the wafer-supporting assembly for an embodiment of the reactor of the invention. As seen from FIG. 5A, the reactor includes the reaction chamber 100 , a spindle 250 having an upper end 280 located inside the reaction chamber 100 , a wafer carrier 200 and a radiant heating element 140 . FIG. 5A shows the wafer carrier 200 in the deposition position. The wafer carrier 200 has a top surface 201 and a bottom surface 202 . The top surface 201 includes cavities 220 for placing wafers. As shown in FIG. 5B, the wafer carrier 200 has a round shape. The bottom surface 202 is parallel to the top surface 201 , except in the regions defined by the cavities 220 . As seen from FIG. 5D, the bottom surface 202 of the wafer carrier 200 includes a central recess 290 . The central recess 290 extends upwards from the bottom surface 202 and terminates in a flat surface 291 surrounded by recess walls 292 . The spindle 250 has a cylindrical shape and an axis of rotation 255 . FIG. 5C shows the upper end 280 of the spindle 250 and the radiant heating element 140 when the wafer carrier 200 is separated from the spindle, such as when the wafer carrier is in the loading position L. As seen from FIG. 5C, the upper end 280 of the spindle 250 has spindle walls 282 that terminate in a top surface 281 . FIG. 5C also shows the radiant heating element 140 having a top surface 141 . The radiant heating element 140 is positioned in such a manner that, during the deposition, the top surface 141 is capable of heating the wafer carrier 200 , which is mounted on the upper end 280 of the spindle 250 above the radiant heating element 140 . In the deposition position D, the upper end 280 of the spindle 250 is inserted in the central recess 290 of the wafer carrier 200 . The flat surface 281 of the spindle 250 lies adjacent to the flat surface 291 of the recess 290 , while the spindle wall 282 is in a direct contact with the recess wall 292 . Upon a complete insertion, the flat surface 281 of the upper end 280 of the spindle 250 is placed in a direct contact with the flat surface 291 of the central recess 290 . Preferably, the highest point or points of contact between the wafer carrier 200 and spindle 250 (in this variant of the invention, the area of contact between the surfaces 291 and 281 ) lies above the center of gravity of the wafer carrier 200 , contributing to the rotational stability of the wafer carrier. The insertion of the upper end 280 of the spindle 250 into the recess 290 creates a friction fit between the spindle wall 282 and the recess wall 292 that allows the rotation of the wafer carrier 200 by the spindle 250 without separate retaining means. During the deposition, the spindle is rotated thereby rotating the wafer carrier 200 and the wafers placed in the cavities 220 . Retaining the wafer carrier on the spindle only by friction allow the minimization of the mechanical inertia of the carrier-spindle assembly and the resulting decrease of the strain on the spindle. If the spindle 250 have to be suddenly stopped and the force of inertia exerted upon the wafer carrier exceeds the force of friction between the upper end 280 of the spindle 250 , the wafer carrier 200 may rotate independently from the spindle, reducing the strain on the spindle. However, the present invention also contemplates the use of a separate retaining means in the wafer-supporting assembly. Examples of such separate retaining means are shown in FIGS. 9A, 9 B and 9 C. As shown in FIG. 9A, the upper end 280 of the spindle 250 may include indentations 289 , extending vertically downward from the flat surface 281 . The wafer carrier 200 may have matching indentations 299 in the flat surface 291 of the recess 290 . The indentations 299 extend vertically upwards from the flat surface 291 . Fingers 800 may then be inserted in the indentations 289 and 299 , tying the wafer carrier 200 and the spindle 250 together. Alternatively, as seen in FIG. 9B, the flat surface 281 of the upper end 280 of the spindle 250 may include raised features 900 , which are integral with the upper end of the spindle. In the deposition position of the wafer carrier 200 , the features 900 are inserted into matching indentations 299 in the flat surface 291 of the recess 290 . Preferably, as seen from FIG. 9C, the retaining means include two fingers 800 or two raised features 900 , and the corresponding number of matching indentations. Another variant of the wafer-supporting assembly is shown in FIGS. 6A and 6B. This variant is similar to the variant shown in FIGS. 5A-5D, with the exception of the wafer carrier/spindle relationship in the deposition position off the wafer carrier. According to this variant of the invention, a bottom surface 302 of wafer carrier 300 also having a top surface 301 has a central recess 390 . The recess 390 includes a narrow portion 392 and a broad portion 391 . The narrow portion 392 terminates in a flat surface 395 . As seen in FIG. 6B, an upper end 480 of the spindle 400 includes a narrow portion 485 and a broad portion 486 . The narrow portion 485 , that includes the spindle wall 482 , terminates in a top surface 481 . In the deposition position, the top surface 481 of the upper end 480 of the spindle 400 is inserted into the central recess 390 of the wafer carrier 300 . The difference between this variant of the wafer-supporting assembly and the previously described variant shown in FIGS. 5A-5D is principally in the shape of the central recess 390 and the upper end 480 of the spindle 400 . Similarly to the variant of the invention shown in FIGS. 5A-5D, the wafer carrier 300 is retained on the upper end 480 of the spindle 400 by the force of friction. In mounting the wafer carrier 300 in the deposition position, the upper end 480 of the spindle 400 is inserted into the central recess 390 until there is a tight fit between the spindle wall 482 and the walls of the recess 390 , which creates a force of friction for retaining the wafer carrier 300 in the deposition position. It also should be noted that the top surface 481 of the spindle 400 may or may be in a direct contact with the surface 395 of the central recess 390 , as will be shown below with reference to FIG. 7A describing another, but similar variant of the wafer-supporting assembly. As explained above, the spindle itself is often a source of a heat drain from the wafer-supporting assembly. Where a wafer carrier for processing a single wafer is mounted on a rotatable spindle, the presence of the spindle has an effect on the temperature of the wafers. The wafer carrier is centrally mounted on the spindle so that the central region of the single wafer cavity on the top surface of the wafer carrier overlies the rotatable spindle. As the spindle draws heat away from the region of the wafer carrier in the central region, the temperature gradient created in the wafer carrier is transferred to the overlying single wafer cavity, resulting in a non-uniform temperature distribution across the surface of the wafer being processed. It is a lesser problem where a plurality of wafers are processed simultaneously using a single wafer carrier since, as can be seen from FIG. 5B, such wafer carrier includes a plurality of wafer cavities arranged symmetrically around the center of the wafer carrier, and no one wafer cavity overlies the axial center of the wafer carrier where the spindle is connected. Hence, the fact that the spindle draws heat away from the center portion of the wafer carrier interferes with the temperature of the wafers positioned in the wafer cavities to a lesser degree than with a single wafer processing. However, even with wafer carriers such as shown in FIG. 5B, the heat drain may create some heating non-uniformity across the wafer carrier's surface. This non-uniformity may be increased for the reactors of the present invention since the wafer carrier is placed on the upper end of the spindle without an intermediate susceptor that is present in the prior art reactors. Therefore, the present invention provides a variant of the wafer-supporting assembly that minimizes the heat drain through the rotatable spindle. This variant is shown in FIGS. 7A, 7 B, 7 C and 7 D. The upper end 580 of the spindle 500 includes a cavity 550 , extending downwards from the top surface 581 . The cavity 550 is substantially coaxial with the spindle 500 . FIG. 7B shows the upper end 580 of the spindle 500 without the wafer carrier 300 . The cavity 550 extends to a cavity end point 570 , which may constitute a flat surface 560 or otherwise. The depth h of the cavity 550 is preferably equal to from about 3 to about 4 of the spindle cavity diameters d (FIG. 7 C). As seen from FIGS. 7B and 7C, the upper end 580 of the spindle 500 has a hollow construction, and the contact area between the top surface 581 and the surfaces of the recess 390 is minimized. This reduces the heat drain from the wafer carrier 300 through the spindle 500 . Further reduction to the heat drain is obtained if the flat surface 395 of the recess 390 is not in contact with the top surface 581 of the spindle 500 , as shown in FIG. 7 A. FIG. 7D shows a preferred relationship between the spindle and the wafer carrier for this variant of the invention. As stated earlier, the point of contact between the wafer carrier and the spindle is preferably above the center of gravity of the wafer carrier. As seen from FIG. 7D, this arrangement may be achieved via an adjustment in the manufacturing tolerances for the upper end of the spindle and the central recess of the wafer carrier. In general, it is difficult to avoid the presence of a small degree of deviation from the intended angle α (FIG. 7 D). However, the bias of the manufacturing tolerance A may be manipulated. Thus, preferably, in the manufacturing process, the angle α for the central recess of the wafer carrier and for the upper end of the spindle is set identically. However, for the central recess of the wafer carrier, the manufacturing tolerance A is given a positive bias, whereas for the upper end of the spindle, the manufacturing tolerance A is given a negative bias. Together with the appropriate choice of the depth for the central recess of the wafer carrier, this minimizes the contact between the wafer carrier and the spindle, and allows the point of contact between the wafer carrier and the spindle to be above the center of gravity of the wafer carrier. To yet further reduce the heat drain through the spindle, the reactors of the invention may be equipped with a novel arrangement of radiant heating elements shown in FIGS. 8A and 8B. FIG. 8A shows a primary radiant heating element 140 and a secondary heating element 700 . The secondary heating element 700 has a top surface 701 and a bottom surface 702 , and is shaped around the hollow upper end 680 of the spindle 600 . The bottom surface 702 of the secondary heating element 700 is located at the same elevation as the endpoint 570 of the cavity 550 , thereby, upon heating, creating a heat barrier against the heat drain from the wafer-supporting assembly. Thus, the hollow upper end 680 of spindle 600 is heated by the secondary heating element 700 , further reducing the heat drain through the spindle. The top surface 701 of the secondary heating element 700 is located at the same elevation as the top surface 141 of the primary radiant heating element 140 . As seen from FIG. 8B, the upper end 680 of the spindle 600 may be the same as the upper end of the spindle in the variant of the invention shown in FIGS. 6A and 6B. Although the present invention has been described herein with reference to the particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

The invention describes a CVD reactor on solid substrates and a related method of deposition of epitaxial layers on the wafers. In the reactor of the invention, the wafer carrier is transported between a loading position and a deposition position. In the deposition position, the wafer carrier is detachably mounted on an upper end of a rotatable spindle without an intermediate susceptor. The reactor of the invention may process a single wafer or a plurality of wafers at the same time. The invention also described several embodiments and variants of the invention. One of the variants of the invention provides a decrease in a heat drain from the wafer-supporting assembly through the spindle and a novel heating arrangement therefore. The advantages of the invention include lower reactor cycle, the lower cost and longer lifetime of the component parts, and better temperature control, among others.

FIELD OF THE INVENTION This invention relates to a system for securing a climbing skin to the bottom of a ski. In particular, the invention relates to a system for securing a climbing skin to one end of the ski, particularly the tail end of the ski, for tensioning a climbing skin. BACKGROUND OF THE INVENTION Climbing skins have been used on skis for many, many years to assist skiers in ascending slopes. Original climbing skins were made from the skins of animals. More recently, climbing skins have been made from synthetic fabrics which have a nap of stiff, rearwardly angled fibers projecting from their bottom surfaces. When the skins are attached to the skis, the skis can be slid in a forward direction relatively easily. When the skis are moved in a rearward direction then the fibers bite into the snow. By attaching climbing skins to both skis, a skier can up even a reasonably steep snow slope by sliding one ski forward and then the other. Attaching a climbing skin securely to the bottom of a ski in such a way that the climbing skin will not be easily dislodged during use and snow will not build up between the base of the ski and the climbing skin can be difficult. The problem of securely attaching climbing skins to skis is exacerbated by the fact that a skier my repeatedly put climbing skins onto skis and take them off during the course of a days skiing. Early climbing skins simply had straps which were used to attach the climbing skin to the ski. Typically straps were provided to stretch the climbing skin between the tip and tail of the ski and additional straps were provided along the edges of the climbing skin. The additional straps could be used to tie the climbing skin to the ski itself. Such climbing skins tended not to work very well because it is generally not possible to tie the skin to a ski tightly enough to prevent snow from building up underneath the climbing skin. Furthermore, the numerous straps were time consuming to attach and keep properly adjusted. More recently, adhesive climbing skins have been developed. Some adhesive climbing skins have a hook or the like which hooks over the tip of the ski. The skin is simply pressed against the ski base and is detachably held in place by a tacky adhesive. Such climbing skins provided acceptable performance when the base of the ski was dry. However, if the adhesive on the climbing skins becomes covered with snow or if the base of the ski becomes wet and has snow adhering to it then the adhesive may not properly hold the climbing skin to the base of the ski. In such cases, the climbing skin can become unstuck from the ski especially at the tail. Climbing skins which use an adhesive as well as tail and tip straps to hold it in place have also become popular. This common tail fixation method is problematic in that it is usually necessary to modify the ski to provide a way to attach a strap to the tail end of the ski. Some current climbing skin systems have a fixture, such as a pin which is screwed into the top surface of the ski near the tail. A strap from the rear end of a climbing skin can then be stretched around the tail of the ski and attached to the pin. This is not desirable because it requires modification of the ski itself. In another common tail fixation method, the skin is riveted to a pair of sandwiching metal plates that include an integral hook for engaging the tail end of the ski. Because the metal hook is relatively rigid, the strap must be moved to the tip end of the ski. Two rectangular metal wire looks (clips) are typically connected by a short (about 4 inches long) elastic, rubbery strip. The skin is fed through a portion of one of these separate clips and is looped back to adhere onto itself. The clip on the other end of the elastic strip is hooked over the tip of the ski to hold the skin in place. Having the elastic strip located at the tip can be a problem when the skier accidentally hits the wire loop with the opposite ski thereby knocking the clip completely off the tip of the ski. Once the skin is free from the tip of the ski, it can drag through the snow and the skin adhesive can become contaminated and eventually fail. There is a need for an attachment system for climbing skins which allows climbing skins to be securely affixed by straps at both tip and tail ends of the ski and yet which is easy to use and does not require modification of the ski itself. SUMMARY OF THE INVENTION In one of its aspects, the present invention comprises a retention system for retaining a climbing skin to the tail end of a ski. The system includes an elongated resilient tensioning member, such as a strap, secured to one end of the skin. A separate, generally C-shaped clip is provided. The clip is adapted to removably hook about the tail end of the ski. Means are provided on an upper portion of the clip for releasably retaining and tensioning a portion of the strap on the clip. The clip provides a securement point for the strap and skin combination and is held by the tensioning effect of the strap. The arrangement is easily field serviceable and no permanent modification to the ski is required. In another aspect of the invention, the clip has a flat base portion adapted to underlie the tail end of the ski, a vertical section adapted to extend behind the tail end, an angled portion extending from the vertical section at an acute angle in relation to the base portion and an upper portion extending from the angled portion and adapted to extend over the tail end. The upper portion includes an aperture sized to receive one end of the tensioning member therethrough. In another aspect of the invention, there are provided a plurality of eyelets longitudinally spaced on the tensioning member, and a projection on the upper portion. The projection is sized to fit within the eyelets to retain the tensioning member on the clip. In a particular aspect of the invention, the upper portion comprises a portion having a generally apical shape having at least one downwardly extending leg and the aperture is located in the downwardly extending leg. In yet another aspect, the invention comprises the method of attaching a climbing skin to the tail end of a ski, comprising providing a climbing skin attached to one end of a resilient tensioning member, hooking a generally C-shaped clip about said tail end of said ski such that a base portion of said clip underlies said tail end of said ski and an upper portion of said clip extends over said tail end of said ski and releasably securing a portion of said tensioning member to said upper portion of said clip so as to tension said clip in engagement about said tail end of said ski. In a more particular aspect of the invention, the step of releasably securing the tensioning member to the upper portion of the clip involves threading that portion of the tensioning member through an aperture in the upper portion of the clip and engaging a projection on the upper portion into one of a plurality of eyelets longitudinally spaced on the tensioning member. In yet a further aspect, the invention comprises a kit for a retention system for retaining a climbing skin on the tail end of a ski, comprising an elongated resilient tensioning member secured to one end of the skin, a generally C-shaped clip adapted to hook about said tail end, said clip having a flat base portion adapted to underlie said tail end, an angled portion extending at an acute angle in relation to the base portion and an upper portion extending from said angled portion and adapted to extend over the tail end, the upper portion being adapted to releasably retain one end of the member. Other aspects of the invention will be appreciated by reference to the detailed description and to the claims. BRIEF DESCRIPTION OF THE DRAWINGS In drawings which illustrate various non-limiting embodiments of the invention: FIG. 1 is a section through a climbing skin mounting system on the rear of a ski; FIG. 2 is a top view thereof; FIG. 3 is a section through an alternative embodiment of a clip which includes a jam nut; FIG. 4 is a partially sectioned top plan view of a clip according to an alternative embodiment of the invention in which a cord lock device holds a cord under tension; FIG. 5 is a schematic, partially cut-away top view of a mounting system according to an alternative embodiment of the invention which has a pair of cords held in a dual-cord cord lock; FIG. 6 is a side elevation of a clip having a pin projecting from a location on its rear side; FIG. 7 is a top view of a further alternative embodiment of the invention wherein a cord is held between a pair of spring-loaded cams; FIG. 8 is a section through a further alternative embodiment of the invention wherein a strap is held by a tension lock; and FIG. 9 is a side elevation of a clip according to an alternative embodiment of the invention wherein a strap passes through an upright flange on the clip. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 show a ski 10 to which is attached a climbing skin 12 . Elongated climbing skin 12 has a nap 13 made of rearwardly angled bristles and is attached to the base 10 A of ski 10 with a suitable removable adhesive 14 . An elongated tensioning strap 16 is affixed to the rear end of skin 12 as discussed in greater detail below. Strap 16 is affixed at the tail 10 B of ski 10 with a mounting clip 18 . Mounting clip 18 is very generally C-shaped in cross-section and hooks around the tail 10 B of ski 10 . Clip 18 has a low rigid flat portion 15 which extends underneath the base 10 A of ski 10 . Clip 18 is rigid so that it can slide onto tail 10 B of ski 10 but cannot rotate when it is on ski 10 . Clip 18 may be made from any suitable material such as steel or a rigid plastic. Strap 16 has a number of longitudinally spaced apertures 17 in its distal portions. A user can apply tension to strap 16 , pull strap 16 around the rear end of clip 18 and then hold strap 16 in place on clip 18 by hooking one of apertures 17 around a projecting pin 20 on clip 18 . In the preferred embodiment shown in FIG. 1, clip 18 has a raised portion 21 in which is an aperture 22 . Strap 16 passes through aperture 22 . Thus, clip 18 remains on strap 16 even when skin 12 and strap 16 are removed from the ski 10 . The shape of clip 18 tends to prevent clip 18 from rotating relative to tail 10 B of ski 10 under the tension forces exerted on strap 16 . The strap 16 exerts a net forward pulling force on clip 18 , i.e. it exerts a net force inward from the tail end 10 B of the ski. This net force acts to retain clip 18 in engagement about the tail end of the ski. Preferably the rear portion 26 of clip 18 has a short vertical surface adapted to extend upward behind the tail end of the ski, and a surface 26 A extending from the top of the vertical surface and which is disposed at an acute angle relative to base portion 15 . Thus, when clip 18 is installed and strap 16 is under tension, the tail end 10 B of ski 10 is wedged into the rear end of clip 18 between surface 26 A and lower portion 15 of clip 18 . This tends to prevent clip 18 from sliding sideways in either direction on the tail 10 B of ski 10 . Unintentional rotation of the clip 18 about the tail end 10 B of the ski is prevented by the bracing effect of the base portion 15 of the clip 18 that underlies the ski and by the angled surface 26 A abutting against the corner of the tail end. It will be appreciated that the length of the base portion 15 and the angle of the surface 26 A can be chosen to nonetheless allow intentional removal of the clip by the user pulling the strap rearward of the ski. Preferably strap 16 and/or skin 12 are slightly resilient so that skin 12 and strap 16 remain under tension while in use. Strap 16 may be made from a strip of fabric-reinforced rubber, or the like. Most preferably, the rearmost end 19 of strap 16 is broadened. This both prevents the accidental removal of clip 18 from strap 16 and provides a convenient hand grip for applying tension to strap 16 when attaching skin 12 to a ski. In the embodiment shown in FIGS. 1 and 2, the strap 16 is releasably affixed to clip 18 by means of a pin 20 on clip 18 which is received through an aperture 17 in strap 16 . Other suitable means for holding the strap 16 is a tensioned manner to clip 18 may also be used. For example, as shown in FIG. 3, clip 18 A may include a jam lever 30 which can be pressed down so as to hold strap 16 in place on clip 18 by compressing a strap between a cam 31 and a surface 32 on clip 18 A. Jam levers are known in the art and can be readily purchased from various sources. Preferably the jam lever 30 is installed so that tension on strap 16 tends to tighten the cam, and thereby prevent strap 16 from becoming loose during use. As shown in FIG. 4, strap 16 could comprise a cord instead of a flat strap or could comprise a flexible flat member having a cord attached to its end. In the embodiment of FIG. 4, a cord 32 attached to a climbing skin passes around the rear end of clip 18 B to be held in place on clip 18 B by a cord lock device 34 . Cord lock devices 34 of various types are well known in the art. The type of cord lock device shown in FIG. 4 has a plug 35 slidably mounted within a housing 36 . Plug 35 is biased toward one side of the housing 36 by a spring 37 . Cord 32 passes through apertures 38 in the housing and the plug and is jammed between the plug and the housing. A release button 39 allows a user to displace the plug 35 against the bias force exerted by the spring 37 to release the cord 32 . Cord lock device 34 is preferably of a type which is designed in such a manner that tension on cord 32 tends to tighten the cord lock device 34 . FIG. 5 shows a clip 18 C in which a skin 12 is tensioned on a ski 10 with a dual-cord cord lock 40 . Cords 32 pass between a wedge 42 and inclined walls 43 . Tension on cords 32 tends to pull wedge 43 rearwardly, thereby tightly gripping cords 32 . The angles of walls 43 relative to the longitudinal center of clip 18 C are exaggerated in FIG. 5 . In the FIG. 5 embodiment cords 32 pass around locating grooves in the rear end of clip 18 C. Locating grooves 44 guide cords 32 . When a strap is affixed to a clip 16 by a way of a tab which projects through a hole in the strap, it is not necessary that the tab be located in the same position shown in FIGS. 1 and 2. FIG. 6 shows a clip 18 D according to an alternative embodiment wherein a tab 20 A projects generally rearwardly from clip 18 . This embodiment is not preferable because of the enhanced likelihood that strap 16 may become accidentally dislodged from tab 20 A in the FIG. 6 embodiment during use. FIG. 7 shows a further alternative embodiment wherein a cord 32 which is attached to the rear end of a climbing skin passes around clip 18 E and is held in place while tensioned between a pair spring-loaded cams 46 . Larger versions of such cams are used, for example, to secure ropes on sailing boats. FIG. 8 shows a clip 18 F according to a further alternative embodiment wherein a strap 16 is held in place by a tension lock assembly 50 . Tension locks are well known and are commonly used to adjust the lengths of straps on backpacks. In a tension lock, a strap is doubled back on itself around a number of surfaces tending to resist slippage. As described above, in preferred embodiments the clip 18 is slidably disposed on the strap or cord which is attached to skin 12 . This prevents clip 18 from becoming lost when skin 12 is detached from ski 10 . The embodiment of FIGS. 1 and 2 shows the strap 16 passing through a pair slots on either side of a bend in the upper portion of clip 18 . Clip 18 could be configured in any of various alternative ways which also cause clip 18 to be slidably disposed on a strap or cord when the skin is detached from a ski. For example, FIG. 9 shows a clip 18 G wherein a strap or cord passes through an aperture 55 in a flange 56 which projects upwardly from a top surface of clip 18 G. A strap or cord could also pass through a loop of cord or elastic attached to a clip 18 . While it is not preferred, a strap 16 could also be held to the top of clip 18 by a section of hook and loop fastener material such VELCRO™, having one part on the clip and another part on the strap. A strap or cord could also be retained on a clip 18 by a snap fastener, mechanical clamp, or the like. Where a mechanical clamp is used a user could pull a strap or cord tight and then secure the strap or cord in place by turning a screw or the like. It will be appreciated that while the embodiments of the invention have been described in some detail, modifications and alterations thereto may be practiced without departing from the scope of the invention.

A retention system for retaining a climbing skin to the tail end of a ski comprises an elongated resilient tensioning member secured to one end of the skin, a generally C-shaped clip adapted to removably hook about the tail end, and means on an upper portion of said clip for releasably retaining a portion of said tensioning member thereon. In the preferred embodiment the upper portion of the clip includes an aperture for receiving the tensioning member therethrough and a projection for engaging in one of several eyelets provided on the tensioning member.

FIELD OF THE INVENTION This invention relates to vanadium oxide crystalline compositions and more particularly to such compositions in which the vanadium oxide forms two dimensional layers between which are intercalated guest cations. BACKGROUND OF THE INVENTION There has been growing interest in vanadium compounds of various types for use as catalysts in a variety of chemical procedures. There also has been particular interest in vanadium oxides for use in electronic devices for heat sensing. There has also been growing interest in layered structures, typically for use as hosts to support guest cations intercalated between the layers. In particular, layered inorganic oxides constitute a diverse class of materials most of which share the common structural feature of a cationic guest which lies between the anionic oxide layers. The largest number of examples known are layered materials composed largely of main group cations like clays, but solids with transition or post-transition elements like the layered double hydroxides and certain alkali metal titanates are also known. Layered oxides hosting both transition and main group cations, such as the Zr, V and Mo phosphates and phosphonates, have also been studied. While many of these solids are noted for their unique characteristic of allowing a wide variety of organic or inorganic chemistries to be performed in the interlamellar region, the closed shell diamagnetic layers serve mainly as an inert nanoscale scaffolding. In contrast to these diamagnetic layers, several lamellar vanadium oxide solids have been prepared by the intercalation of both alkali metal cations and conductive organic polymers between layers of V 2 O 5 . The present invention represents novel forms of such layered structures involving vanadium oxides. SUMMARY OF THE INVENTION The present invention provides compositions of the generic formula (M.sub.1).sub.a (M.sub.2).sub.b (M.sub.3).sub.c [V.sub.x O.sub.y ]·zH.sub.2 O in which the layered mixed-valence vanadium oxide forms host layers between which are intercalated either a) cationic transition or post-transition metal coordination complexes, b) monomeric ammonium or diammonium cations, or c) a mixture of alkali metal cations and monomeric ammonium or diammonium cations. In the generic formula, M 1 is a metal-coordination complex [L n A] +w , where L is a bidentate amine ligand, A is a transition or post-transition metal, n is equal to 1, 2 or 3, and w is 1, 2, 3 or 4. When a is other than zero, b and c are zero. When b has a non-zero value, a is equal to zero and c may or may not have a non-zero value. When c has a value, M 3 is an alkali metal cation. More complete descriptions of M 1 , M 2 and M 3 and particular examples of each will be provided in the more detailed description. DETAILED DESCRIPTION OF THE INVENTION As set forth above, the generic formula of compositions provided by the invention is (M.sub.1).sub.a (M.sub.2).sub.b (M.sub.3).sub.c [V.sub.x O.sub.y ]zH.sub.2 O. As mentioned above, M 1 is a metal coordination complex given by [L n A] +w , where the bidentate ligand L is a diamine of the form R 2 N(C m H 2m )NR 2 , or an aromatic diamine. R, as is familiar to the art, corresponds to C p H 2p+1 where 1≦m≦4, 0≦p≦4, the metal A is a transition or post-transition metal, preferably either Ni, Cu, or Zn, and w is an integer from 1 to 4. The group in which the guest cations are solely interlayer transition or post-transition metal coordination complexes M 1 will be described as the first group of the generic formula. The compositions of this first group of the generic formula, corresponding to b and c equal to zero in the generic formula, have been prepared, for example, in a single step by the reaction of a transition or post-transition element source, a bidentate amine and V 2 O 5 in water sealed in a 23-ml poly(tetrafluoroethylene) lined acid digestion bomb and heated in the 170°-200° C. range and are isolated as highly crystalline, typically thin black plates. Since no external reducing agent is employed, the amine presumably serves as the reducing agent. The materials, (L 2 M) y [VO x ] with L=bidentate amine, M═Cu, Ni or Zn, 0.16≦y≦0.33 and 2.33≦x≦2.83, share common structural features of a mixed valence V 4+ /V 5+ oxide layer as well as a six coordinate interlayer cation with four of the six co-ordination sites occupied by N atoms from two bidentate amine ligands and two sites from O atoms of the VO layer. The layers are built up in all cases from VO 5 square pyramids and VO 4 tetrahedra connected by edge and corner sharing interactions. As an example of the preparation of a compound of the first group, there was heated together at a temperature of 170° C. for 44 hours and then at 200° C. for 112 hours a mixture of 0.312 gram of V 2 O 5 , 0.049 gram of ZnO, 10 milliliters of H 2 O and 0.325 gram of 2,2'-dipyridyl. After such treatment, there was filtered a mixture of brown chunks of [(bipy) 2 Zn] 2 [V 6 O 17 ] and black rod-shaped crystals of VO(VO 3 ) 6 [VO(bipy) 2 ], where (bipy)=2,2'-dipyridyl, and a small amount of unidentified green powder. The structure of the compound [(bipy) 2 Zn] 2 [V 6 O 17 ], which is to be designated as Compound 1, consists of VO layers, which, when viewed parallel to [100], display a very pronounced sinusoidal ruffling with an amplitude of ca. 13 Å and a period of ca. 15 Å. These layers are composed solely of V 5+ O 4 tetrahedra, each of which has a terminal vanadyl (V═O) group and shares three corners with three neighboring VO 4 units. Within each VO layer there are very large, roughly circular rings, which alternately lie in planes approximately parallel to (011) and (011), defined by fourteen VO 4 tetrahedra with a transannular V-V distances near 13 Å. There are two Zn atoms per ring, on either side of the 1 site in the center of the ring, each bonded in a cis fashion to two oxygen atoms from two second nearest neighbor VO 4 groups on opposite sides of the ring. The two Zn atoms have bipy ligands that protrude above and below the mean plane of the V 14 ring and fill the troughs created from the ruffling of the layers with the organic ligands. The use of ethylenediamine (en) as a bidentate ligand has allowed not only the isolation of several new one dimensional (1-D) Cu-en-VO materials but several layered solids as well. Two layered examples from the en system are the isotypic, mixed valence V 4+ /V 5+ vanadium oxides (en) 2 Zn[V 6 O 14 ] and (en) 2 Cu[V 6 O 14 ] to be designated Compounds 2 and 3, respectively. Compound 2 was prepared by mixing 0.192 (g) of V 2 O 5 , 0.042 (g) of ZnO, 10 (ml) of H 2 O and 0.2 (ml) of en and heating to 170° C. for 66 hours. Compound 3 was prepared by heating 170° C. for 65 hours a mixture of 0.17 (g) of copper chloride dihydrate, 0.181 (g) of V 2 O 5 , 0.28 (ml) of en and 8 (ml) of water. Both materials contain Cu or Zn in a distorted MO 2 N 4 octahedral environment coordinated to four N donor atoms, which lie approximately in a plane parallel to the VO layers, and two trans O atoms from two adjacent layers, coordinated via very long M--O interactions. While this nearly square planar coordination is not atypical for the Cu in Compound 3 (four N at ≈2.07 Å; two O at 2.53 Å), it is unusual for the Zn found in Compound 2 (two N at 2.12 Åand two at 2.07 Å; two O at 2.45 Å). The VO layers in Compounds 2 and 3 contain infinite zig-zag chains of edge-sharing V 4+ O 5 square pyramids running parallel to [010], with their terminal vanadyl groups oriented in pairs toward opposite sides of the layer, connected together by V 5+ O 4 tetrahedra giving a layer composition of [(V 5+ ) 2 (V 4+ ) 4 O 14 ] 2- according to valence sum calculations. Surprisingly, in spite of the fact that 2/3 of the V atoms are in the 4+ oxidation state (d 1 ), Compound 2 does not give an ESR signal and is nearly diamagnetic according to preliminary magnetization measurements that show that χ=M/H actually decreases in the range 150<T<300K. Compound 3 also appears to have layers with suppressed magnetic moments with μ eff (300K)≈2.2 BM (μ eff =[8χT] 1/2 ) only slightly greater than that expected (˜1.8 BM) for the Cu 2+ (S=1/2). Below room temperature, the moment slowly decreases and reaches the value expected for only the Cu 2+ by ˜70K and below this temperature χ -1 (T) is linear (unlike T>70K) with a θ near zero indicative of a paramagnet. The magnetic data for Compounds 2 and 3 imply that either the layers have already undergone an antiferromagnetic phase above room temperature or the spins are paired within states that are delocalized within the layers. Changing the reaction conditions in the en/Cu 2+ V 2 O 5 system gives rise to other vanadium oxides with ligated Cu bound to the layers, such as [(en) 2 Cu] 2 [V 10 O 25 ], to be designated as Compound 4. This was prepared by heating at 170° C. for 42 hours a mixture of 0.51 (g) of copper chloride dihydrate, 0.181 (g) of V 2 O 5 , 0.45 (ml) of en and 8.0 (ml) of water. Like Compounds 2 and 3, Compound 4 has a nearly square planar (en) 2 M 2+ (M═Cu) cation bonded to two trans oxygen atoms from two adjacent layers which are formulated as [(V 5+ ) 6 (V 4+ ) 4 O 25 ] 4- according to valence sum calculations. The layers are built up from double strands of infinite corner sharing strings of edge-sharing trimeric VO 5 square pyramids, which run parallel to [001] and are connected together by VO 4 tetrahedra. The double strands are in turn bridged together by additional VO 4 tetrahedra to create a layer containing ordered voids with O--O diameters of 6 Å. Magnetization data shows that μ(300K)≈5.5 BM which is well below that expected for the six unpaired spins from 2 Cu 2+ and 4 V 4+ . The moment decreases nearly linearly over the entire range 20K<T<300K and reaches a value of ca. 2.8 BM near 10K which is the moment expected for two Cu 2+ (S=1/2) centers. Below ca. 15K, χ -1 (T) is linear with a θ near zero consistent with paramagnetism. Thus the magnetic behavior of Compound 4 resembles that of Compound 3 in that the layers have magnetic moments that slowly decrease over large temperature intervals, with no characteristic anomalies indicative of a phase transition, and appear essentially diamagnetic at very low temperatures. As mentioned previously, another major group of the generic formula corresponding to a and c equal to zero in the generic formula, to be designated group 2, consists of organically templated mixed-valence vanadium oxides. In this second group, M 2 is an organic cation taken from the group consisting of R 4 N + , cyclic ammonium or polyammonium cations [Q 4-p N(C n H 2n ) p NQ 4-p ] +f where 1≦p≦3 and Q═R, C 6 H 5 or (C n H 2n ) N + R 3 with 1≦n≦4, and R is C m H 2m+1 or C 6 H 5 , where m=0≦m≦4 and f is the number of N atoms in the cyclic ammonium or polyammonium cation. An example of this group 2 is (H 3 N(CH 2 ) 3 NH 3 )[V 4 O 10 ] to be designated Compound 5. Black plate-like crystals of Compound 5 were prepared from the hydrothermal reaction of 0.296 (g) of V 2 O 5 , 2.0 (ml) of 1.0M HCl, 0.2 (ml) of (dap) and 10 (ml) of H 2 O at 170° C. for 66 hours, where (dap) is 1,3-diaminopropane. A single crystal X-ray diffraction study of Compound 5 revealed the novel vanadium oxide layers with propanediammonium dications occupying the interlamellar space. The layers are constructed from equal number of VO 4 tetrahedra and VO 5 square pyramids. While VO 4 tetrahedra are isolated from each other, the VO 5 square pyramids exist in pairs sharing one edge. Within a pair of square pyramids, the two apical oxygen atoms are oriented toward opposite sides of the plane of the layer. Each pair of the pyramids is linked to six VO 4 tetrahedra via corner-sharing, forming two dimensional layers. There are four independent V sites in this structure. While the atoms V(1) and V(4) have a distorted square pyramidal configuration, the atoms V(2) and V(3) are in a fairly regular tetrahedral coordination environment. The V-O bond distances of V(2)O 4 tetrahedron are in the range of 1.648 (4)-1.826 (4) Å, and bond angles in the range of 106.0(2)-113.2(2)°. The V(3)O 4 tetrahedron has bond distances in the range of 1.643 (5)-1.834 (4) Å, and bond angles in the range of 107.6(2)-111.3(2)°. The V(1)O 5 square pyramid has the shortest bond distance of 1.612 (4) Å formed with the vanadyl oxygen O(9), and the rest of the four V-O bond distances in the range of 1.912 (4)-1.967 (4) Å. The V(4)O 5 square pyramid has its vanadyl oxygen O(7) at a distance of 1.603 (4) Å, and the other four oxygen atoms at distances in the range of 1.924 (4)-1.974 (4) Å. While the square pyramidal vanadium has an oxidation state of +4, the tetrahedral vanadium is indicative of an oxidation state of +5. This assignment of oxidation state is consistent with the overall charge balance of the compound and confirmed by the valence sum calculation which gave a value of 4.1 for V(1) and V(4), and 4.8 for V(2) and V(3). There is an extensive hydrogen bonding network formed among the --NH 3 + groups of the propanediammonium cations and the terminal oxygen atoms (O(6), O(7), O(9), O(10)) from the oxide layers above and below. This extensive hydrogen bonding motif causes the organic components to be released only at elevated temperatures. Thermogravimetric analysis (TGA) at a heating rate of 10° C./min. under N 2 showed no weight loss until ca. 300° C. where the release of the organic component commences. There has been a great deal of interest in vanadium bronzes M x V 2 O 5 , especially lithium vanadium bronzes Li x V 2 O 5 , because of their interesting electronic properties and potential applications in high energy batteries. The oxide layers in the structures of Compound 5 are similar to those in the structure of CsV 2 O 5 , described in Acta Cryst 1977, B33, 789 by K. Walterson et al, where the Cs + cations lie between the vanadium oxide layers. Compound 5 is believed to represent the first example of a new class of materials: organically based vanadium bronzes. One would expect that new vanadium oxide structure types can be made by introduction of organic templates of different sizes and charges. In fact, we have isolated several new layered vanadium oxides containing different organic cations including α- and β-(H 3 N(CH 2 ) 2 NH 3 )[V 4 O 10 ], (HN(C 2 H 4 ) 3 NH)[V 6 O 14 ]. H 2 O, α- and β-(H 2 N(C 2 H 4 ) 2 NH 2 )[V 4 O 10 ]. The third group corresponds to the situation where a=0, and both b and c have real values in the generic formula, so that both M 2 and M 3 are included. An example of this group is Cs 0 .29 (DABCO) 0 .34 V 2 O 5 where DABCO is diprotonated 1,4-Diazabicyclo[2.2.2] octane N(C 2 H 4 ) 3 N. Samples of this were prepared by heating at 170° C. for 112 hours a mixture of 0.202 (g) CsVO 3 , 0.312 (g) H 2 O 3 PCH 3 , 10 (ml) H 2 O and 0.310 (g) DABCO. Other members of this group can be formed by including cations from the others of the alkali metal group, K + or Rb + . The following are additional examples of the preparation of further representatives of the general class. A mixture of 0.277 grams of V 2 O 5 , 0.049 gram of Cu0, 10 milliliters of water and 0.3 milliliter of H 2 N--CH 2 --CH 2 --CH 2 --NH 2 (dap) was heated at 170° C. and after 44 hours 0.118 grams of a solid was recovered after filtering, washing and air-drying. The solid was found to be of the following composition: (dap) 2 Cu[V 6 O 14 ], a member of the first group. A mixture of 0.130 gram of V 2 O 3 , 0.197 gram of piperazine and 10 (ml) water was heated at 170° C. After 67 hours, and after filtering, water washing and air drying there was recovered 0.122 gram of a solid whose composition was found to be (H 2 N(CH 2 CH 2 ) 2 NH 2 )[V 4 O 9 ], a member of the second group. A mixture of 0.218 gram of V 2 O 5 , 0.181 gram of piperazine and 10 milliliters of water was heated at 170° C. and after 115 hours there was recovered 0.152 gram of a solid whose composition was found to be a mixture of α- and β-phase of (H 2 N(CH 2 CH 2 ) 2 NH 2 )[V 4 O 10 ], a member of the second group. A mixture of 0.173 gram of V 2 O 5 , 0.1 milliliter of en and 10 milliliters of water was heated at 170° C. and after 121 hours there was recovered 0.10 gram of a solid whose composition was found to be a mixture of α- and β-phase of (H 3 NCH 2 CH 2 NH 3 )[V 4 O 10 ], also a member of the second group. A mixture of 0.257 gram of CsVO 3 , 0.186 gram of H 2 O 3 PCH 3 , 0.1 milliliter of en and 8 milliliters of water was heated at 170° C. and after 69 hours there was recovered 0.075 gram of a solid whose composition was found to be a mixture of α- and β-phase of (H 3 NCH 2 CH 2 NH 3 )[V 4 O 10 ], a member of the second group. A mixture of 0.225 gram of V 2 O 5 , 0.201 gram of DABCO and 10 milliliters of water was heated at 170° C. and after 45 hours there was recovered 0.127 gram of a solid whose composition was found to be (HN(C 2 H 4 ) 3 NH)[V 6 O 14 ]. H 2 O, another member of the second group. A mixture of 0.192 gram of V 2 O 5 , 0.042 gram of ZnO, 10 milliliters of water and 0.2 milliliter of en was heated at 170° C. and after 66 hours there was recovered 0.187 gram of a solid whose composition was found to be (en) 2 Zn[V 6 O 14 ], a member of the first group. A mixture of 0.5 gram of nickel acetate, 0.181 gram of V 2 O 5 , 0.45 milliliter of ethylenediamine and 8.0 milliliters of water was heated to 200° C. After 74 hours, there was recovered a cluster of black crystals of (en) 2 Ni[V 6 O 14 ], another member of the first group. A mixture of 0.51 gram of copper chloride dehydrate, 0.181 gram of V 2 O 5 , 0.45 milliliter of ethylenediamine and 8.0 milliliters of water was heated at 170° C. After 42 hours, there was recovered crystals of [(en) 2 Cu] 2 [V 10 O 25 ], also a member of the first group. A mixture of 0.17 gram of copper chloride dihydrate, 0.181 gram of V 2 O 5 , 0.28 milliliter of ethylenediamine was heated to 170° C. After 65 hours, there was recovered 0.1743 gram of (en) 2 Cu[V 6 O 14 ], also of the first group. A mixture of 0.34 gram of copper chloride dihydrate, 0.181 gram of V 2 O 5 , 0.8 milliliter of ethylenediamine and 8.0 milliliters of water was heated to 125° C. After 68 hours there was recovered 0.215 gram of a solid of which most was (en) 2 Cu[V 6 O 16 ] and some was (en)Cu[V 2 O 6 ], members of the first group.

A number of layered vanadium oxide crystalline compositions are prepared by simple hydrothermal reactions. Generally, the compositions comprise parallel layers of mixed valence vanadium oxides with guest cations intercalated between the layers. The guest cations may comprise metal coordination complexes with bidentate ligands, monomeric ammonium or diammonium cations, or mixtures of alkali metal cations with monomeric ammonium cation or diammonium cations.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims benefit of provisional patent 61/398,414 filed Jun. 25, 2010 STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC [0003] Not Applicable APPENDIX [0004] Not Applicable BACKGROUND OF THE INVENTION [0005] This invention addresses the desire of shooters to observe target hits as soon as they occur. Many targets incorporate materials that react when struck by a projectile, but many of these require metal projectiles traveling at high velocities. Inherent to the mass and speed of metal projectiles, is the risk of serious injury. Therefore, Airsoft bbs have become prevalent in order to afford restrictive societies with the enjoyment of shooting without the high risk associated with metal projectiles. In order to achieve the delicate balance between reactivity and durability, design considerations have been guided toward greater technical proficiency on the part of the user. More is required than simply pointing and shooting at a target. The user is to be educated by detailed instructions as to the proper employment and interpretation of this technology. This invention eclipses earlier attempts at creating a re-useable reactive target in that it is designed to work well within the limited velocities and ranges found with Airsoft bb launchers. This invention differs from earlier attempts by the fact that the target faces can be machine-washed and dried, and hand-ironed for re-use. BRIEF SUMMARY OF THE INVENTION [0006] Although this invention may be used for firearms and metal-projectile bb/pellet guns, it is recommended that it be used for what is known as “Airsoft” bb/pellet guns. Prior art makes its claims based on firearms and that prior art requires the energy and mass produced by firearm/metal-projectile launchers (hereafter referred to as “bb guns”). In order for the safer sport of Airsofting to enjoy the same visually appealing effects generated by the aforementioned firearms and bb guns, it is necessary to construct a product that: (1) Falls into the same cost-ratio percentile as firearms and bb guns, and (2) Is durable to a substantial degree. The genius of this invention is that it allows the user to hit a point and that point will exhibit a noticeable coloring from the puffing agent. If the same exact point is struck again, the area will generate an even bolder coloring. Successive hits, at that same point, will continue to produce coloring until the area becomes saturated, and then the puffing agent will become airborne in a noticeable manner. The ability to design and manufacture a target that should be used primarily with plastic airsoft bbs is one to be respected and applied vigorously to the growing Airsoft-gaming trend. A key feature of this invention is the fact that the target faces can be machine-washed and dried, and hand-ironed for re-use. BRIEF DESCRIPTIONS OF THE SEVERAL VIEWS OF THE DRAWINGS [0007] FIG. 1 is a not-to-scale CAD image two dimensional isometric view of an assembled Ruff Puff 5×5 Reactive Airsoft Target System (R.A.T.S.), and the image depicts the external view of both versions 1 and 1a. [0008] FIG. 2 shows an exploded isometric view of the components of the target. Numeral 1 is a 1.4 inch circle of white polyester fabric of a loft height of 0.25 inches. Numeral 2 is a 0.125 inch colored border which delineates numeral 1 's area. Numeral 3 is edge art designed to make the target more visually appealing and consists of the same marking medium as the center circle labeled “Numeral 2 .” Numeral 4 depicts Numerals 1 , 2 , and 3 together in order to provide a complete visual representation of the face of the target. Numeral 5 is the first polyester layer of 5 inch by 5 inch by 0.25 inch loft on which the face art will be affixed. Numeral 6 is a second polyester layer of 5 inch by 5 inch by 0.25 inch loft. Numeral 7 is the third polyester layer of 5 inch by 5 inch by 0.25 loft, and it is between the the polyester layers labeled 6 and 7 that the puffing agent will be sequestered. Numerals 5 , 6 , and 7 will be affixed to one another by either: glue, sewing stitches, or heat welding. Numeral 8 depicts the 5 inch by 5.4 inch plastic canvas mesh of either: 5, 7, or 9 openings per inch; drilled wood panel with circular holes comparable to the aforementioned plastic mesh; or metal mesh like dimensioned as the above materials. Numeral 8 affords the target with structural integrity, an anchor point for a fastening device in order to attach the target to a fixed object, a mounting point for the puffing agent packets (PAP) that sequester the puffing agent, and provides a medium to absorb impact energy and reflect that energy back into the puffing agent in order to cause the agent to exit the target and become airborne. Numerals 1 a , 2 a , 3 a , 4 a , 5 a , 6 a , 7 a , and 8 a all depict the reverse side of the target. [0009] FIG. 3 is another exploded isometric view which differs from FIG. 2 only in that there are only two 5 inch by 5 inch by 0.25 inch polyester layers. It is important to note that the number of polyester layers is important to the extent that kinematic energy is absorbed and reflected in order force the puffing agent to become airborne in a visually stimulating manner. [0010] FIG. 4 depicts an enlarged view of the three-layer Puffing Agent Packet which is version 1 . [0011] FIG. 5 is an enlarged view of the two-layer Puffing Agent Packet which is version 1a. [0012] FIG. 6 is a not-to-scale isometric view of an assembled Ruff Puff Boxer Reactive Airsoft Target System (R.A.T.S.) which is a 4-sided target utilizing the above-mentioned Ruff Puff Puffing Agent Packet technology. [0013] FIG. 7 is an exploded isometric view of the target described in FIG. 6 above. Item 8 has been omitted for clarity in offering numeral 9 which is an “X” type mounting to affix the one-sided 5 inch by 5 inch by 0.25 inch polyester target without a reverse side. The dimensions of numeral 9 are: 7.071 inches (the hypotenuse of the 5 by 5 targets) by 5.4 inches and serves as a spreader for geometric symmetry, an anchor point in which to attach a fastener, and to provide structural integrity. [0014] FIG. 8 is a not-to-scale CAD image of a Ruff Puff Concentric Circle (CC) Reactive Airsoft Target System (R.A.T.S.). Numeral 10 depicts the 3 inch diameter center ring. This ring is constructed of two 2.625 inch diameter circles of polyester material 0.25 inch loft height. They are hinged by a 0.500 inch piece of the same material which shape is cut out of a single piece of material and folded at the hinge point. Numerals 14 , 16 , and 18 all depict the target rings that are the objective of the launched projectile and share in common their use of the puffing agent packets illustrated in FIG. 9 . These puffing agent packets are bracketed in front and back by 13.125 inch by 13.125 inch by 0.25 inch layers of polyester material as presented in FIG. 10 . Numeral 24 shows a 0.25 inch wide glue, stitch, or heat-weld ring used to separate the 3 inch diameter center ring from the 6 inch number two ring and provide an anchor point for the two 13.125 inch by 13.125 inch by 0.25 inch polyester layer. Numeral 25 shows another glue, stitch, or heat-weld ring used to separate the 6 inch number 2 ring from the 9 inch number 3 ring and also serves as an attachment point for the polyester layers. Numeral 26 depicts the glue, stitch, or heat-weld ring for separation of the 9 inch number 3 ring and the 12 inch number 4 ring as well as providing an attachment point. Numeral 27 shows the glue, stitch, or heat-weld ring which provides containment for the 12 inch number 4 ring and an attachment point. Numeral 28 shows a 2 inch by 2 inch by 2.828 inch glue, stitch, or heat-weld area. There are four of these areas on the target and they provide structural integrity and durability as an attachment point. Numeral 29 depicts a 0.25 inch wide glue, stitch, or heat-weld border that serves to attach the polyester layers to one another and to provide structural integrity while reducing fraying at the border. Numeral 30 depicts the energy absorbing/reflecting surface, which consists of plastic canvas mesh, pre-drilled wood, or metal mesh, that redirects the kinematic energy imparted by the impacting mass for transference into the puffing agent. (Numerals 22 and 23 are for manufacturing purposes.) [0015] FIG. 9 is a not-to-scale, blown-up, cut-out, front view of Puffing Agent Packet version 2 which is rendered in order to better illustrate the puffing agent packet technology. Puffing agent is sequestered between two layers of porous material. Variable arc lengths allow for interchangeability between ring sizes. These puffing agent packets are bracketed by larger polyester sheets as described in FIG. 8 and FIG. 10 . [0016] FIG. 10 shows an exploded isometric view of a Ruff Puff CC (Concentric Circle) Reactive Airsoft Target System (R.A.T.S.). Numeral 10 is the 3 inch center circle target area. Numeral 11 is a border material made up of rope, plastic, nylon, or other flexible material used to prevent bleed-over by the puffing agent caused by gravitational and atmospheric forces. Numeral 14 is the 6 inch number 2 ring target impact area which contains the puffing agent packets of FIG. 9 under the face layer of 13.125 inch by 13.125 inch by 0.25 inch polyester that is border on the exterior by the flexible barrier material that remains in place due to being fixed by attaching agents. Numeral 13 is the flexible barrier/border made of rope, plastic, nylon, or other malleable material. Numeral 16 is the 9 inch number 3 ring that utilizes the same construction as the 6 inch number 2 ring. Numeral 15 is the flexible material border as used in numeral 11 . Numeral 18 is the 12 inch number 4 ring that utilizes the same construction as rings 2 and 3 . Numeral 17 is the same flexible material border as in numeral 11 . Numerals 28 and 29 depict the triangular glue, stitch, or heat-weld areas as mentioned in FIG. 8 . Numeral 31 shows the 13.125 by 13.125 by 0.25 polyester layer that comprises the innermost layer of the polyester material. A 13.125 inch by 13.125 inch by 0.25 inch polyester sheet is laid as base. The tubular puffing agent packets and circular center packet are attached to this base sheet. Another 13.125 inch by 13.125 inch by 0.25 inch polyester layer is placed over the base layer and the puffing agent packets and attached. The flexible border material is placed along the perimeters of the rings desired impact area. Numeral 32 is the assembled target with the rigid energy reflecting back. DETAILED DESCRIPTION OF THE INVENTION [0017] Having described the invention in detail, those skilled in the art will appreciate that other embodiments may be made of the invention without departing from the spirit of the invention described herein. For instance, many different target shapes may be used. Therefore, it is not intended that the scope of the invention be limited to the specific and preferred embodiments illustrated and described herein. Rather, it is intended that the scope of the invention be determined by the appended claims and their equivalents [0018] The invention is produced by cutting five pieces of 0.25 loft polyester batting to approximately 10 inches wide by 10 inches long. Also cut to a 10×10 dimension is clear plastic ten-mesh sheet. Two 10×10 polyester sheets are designated for the core and three sheets will become 3 separate target faces. The core sheets are place one on top of the other, edges lined up square, and the top core sheet is marked with sew-lines. [0019] The sew-lines are achieved by placing a pre-made template (which has slots of equal and preset distances (approximately 2 inch squares) through which a marking medium may inserted) over the top core sheet and a marking medium is used to place registration lines. The two core sheets are then sewn along three border registration line sets; leaving one side open in which to insert the puffing agent. At this point, the interior registration lines and one border remain unsewn. [0020] A pre-measured amount of puffing agent is then placed between the two core sheets. The puffing agent is then manipulated to completely cover the bottom-most core sheet in a level and equal manner. Once the puffing agent is equally distributed between the polyester core sheets, the remaining side is sewn to close the core. [0021] The core is then gently placed on the clear plastic 10-mesh canvas and the corners squared. The core sheets and plastic mesh are then sewn together on an X-and Y-axes equal distances from the center point. Once center point has been identified, the Y-axis sewing begins one registration line above the center point and ends one registration line below the center point (approximately 4 inches in each axis). The X-axis sewing begins one registration line to the left and ends one registration line to the right of the center point. This sewn crosshair provides stability during the sewing process and adds to the functioning and durability of the target core. [0022] The target core is then sewn along the remaining registration lines and this process has now created another configuration of the all-important “Puffing Agent Packet.” The core is set aside and will be trimmed later. [0023] The target faces are produced by stenciling borders, graphics, and text onto the target face and attaching hook side of hook-n-loop fasteners to the reverse. The target graphics consist of any non-proprietary image or design and a 0.300 inch (approximately) colored border that effectively frames the target and also acts as a guide for, and obscures the view of, the hook fastener on the reverse side. [0024] The graphics, border, and text are currently inked onto the polyester batting surface by use of stencils, but ideally, inkjet production inking technology will replace this process. [0025] On the reverse side (non-graphics side), strips of hook fastener (approximately 0.250 inches wide) run the length and width of the target face basically mirroring the inked border on the obverse side and are tacked into place with glue which forestalls the flexing and elastic deformation of the target face. The hook fastener is then sewn into place by sewing machine. Loop-side fasteners are then attached to the hook fasteners for when the face is not in use. [0026] The target faces are trimmed by placing a ruled edge on the inked border and cutting off flush with the inked surface on the left and right sides. The top of the target face is cut approximately 0.500 inches above the inked border and the bottom of the target face is cut approximately 0.500 inches below the inked border. [0027] The target core is trimmed by using a template that trims the core to slightly larger than the target face in order to maximize hook fastener attachment (the hook fastener attaches very well to the polyester core surface). The over-sized core also compensates for individual user tastes and attachment techniques while also taking into account the variations in size of the target faces when the target faces are washed, dried, and ironed back into original configuration. After the core is trimmed, two 4-inch long zip-tie type fasteners are threaded into the top of the plastic canvas mesh. One is inserted two inches from the left border of the core, and the other is inserted two inches from the right border of the core. These ties are inserted 2 full mesh squares down from the top of the core. The core is now placed into a vacuum bag, placed into a vacuum packing machine, the air removed, and the package sealed. This is done to minimize shifting of the puffing agent during handling and transport. The core is now in shipping configuration. [0028] Three target faces, each with different graphics, are placed in a shipping bag with the vacuum-packed core and instructions for use. The target is ready for shipping. [0029] This description of this evolution of the invention should not be seen as limiting the patentable aspect of the invention. Due to the nature of the malleability of the plastic canvas mesh, the polyester batting, the puffing agent, and the sewing, a military-type man-size silhouette comprised of multiple cores attached to one another and trimmed to the desired form, would be but a normal advancement of the “Puffing Agent Packet” technology. It is the Puffing Agent Packet (PAP) that is the concept of interest for patenting this invention. [0030] The same Puffing Agent Packet technology is utilized in the Ruff Puff Grenade Rap. This construction is comprised of two 8 inch by 3.75 inch sheets of 0.25 inch loft (low loft) white polyester and one 8 inch by 3.75 inch sheet of porous black nylon fabric. The bottom sheet of white polyester has a 1.0 inch by 1.0 inch hook fastener sewn approximately 1.75 inches in from the left side approximately 1.5 inches down from the top edge. This process is repeated for the right side. Adhesive-backed loop fasteners of dimensions of 1.0 inches by 1.0 inches are mated to the hook fasteners and allow for the grenade wrap to be securely fastened to the CO2 airsoft grenade. The three sheets are then sewn together 1.875 inches down from the top and along the 8 inches of their longest axis (down the middle long-ways). A pre-measured amount of Puffing agent is placed between the white polyester sheets of the upper half and evenly spread to cover the bottom sheet of polyester. This half is then sewn 0.25 inches down from the top edge of this upper half in order to contain the puffing agent. This process is repeated for the lower half. A containment sew line is made 0.25 inches in from the left side and the right side. The left side is defined as the side where the loop fastener is sewn. The right side is defined as where the hook fastener is sewn. The left side is sewn top to bottom 1.5 inches in from the left 0.25 inch sew-line and the right side is sewn top to bottom 1.5 inches from the right side 0.25 sew-line. Another top to bottom sew-line is sewn 3 inches from the right side 0.25 inch sew-line. These sew-lines result in 8 individual puffing agent packets: six each of 1.5 inch by 1.75 inch packets and two each of 1.75 inch by 3.5 inch packets. A three-inch long by 0.75 inch wide loop fastener is sewn 0.375 inches down from the top-left edge flush with the left edge and is located on outside plane of the bottom sheet which is the same plane as the 1.0 inch by 1.0 inch hook-n-loop fasteners. A mating hook fastener, 3.0 inches by 0.75 inches, is sewn 0.375 inches down from the right side and is flush with the right side; it is located on the black-nylon-mesh side of the grenade wrap, which is opposite of the mating loop fastener and creates a hook-n-loop fastening system which provides for closing the of the Ruff Puff Grenade Rap around the CO2 airsoft grenade.

This invention is a target that uses the kinetic energy stored in a plastic bb after it has been launched and transfers that energy into the target mass in order to cause a colored particulate matter to be expelled in such a manner as to make a mark on the target surface and to expel the same particulate matter into the surrounding area. This target reacts to the energy in order to visually inform the user that the target has been hit and, in the preferred embodiment, the point at which the impact occurred. Again, in the preferred embodiment, the colored particulate matter will be expelled both in front and back of the target. Additionally, the target faces can be machine-washed, dried, and hand-ironed for re-use.

BACKGROUND OF THE INVENTION This invention relates to methods for diffusion bonding surfaces together and, more particularly, to a method for thermo-compression diffusion bonding separate structured copper strain buffers directly to each side of a substrateless semiconductor device wafer. DESCRIPTION OF THE PRIOR ART When attaching a heat sink to a semiconductor device wafer, it is often desirable that this attachment occur as close to the semiconductor device wafer as possible in order to provide optimum heat removal from the wafer. Such is the case when a heat sink is attached via a structured copper strain buffer (a bundle of substantially parallel, closely packed filamentary strands of copper of substantially equal length, one common end thereof being thermo-compression diffusion bonded to a metallic sheet) to a semiconductor device wafer. Prior high power semiconductor devices include a metallic support plate or substrate, typically comprised of tungsten or molybdenum, attached to one surface of a semiconductor device wafer to provide it with structural strength. Heat sinks are attached with thermo-compression diffusion bonds via structured copper strain buffers to one or both sides of such wafer-support plate structures. A bonding press capable of producing such thermocompression diffusion bonds is described in Douglas Houston U.S. patent application Ser. No. 927,344, filed July 24, 1978, now abandoned in favor of divisional application Ser. No. 139,177, filed Apr. 11, 1980 and assigned to the instant assignee. A method for thermo-compression diffusion bonding a structured copper strain buffer to a semiconductor device wafer supported by a tungsten or molybdenum support plate is described and claimed in Glascock et al. U.S. patent application Ser. No. 958,100, filed Nov. 6, 1978 and assigned to the instant assignee. It is desirable, however, to diffusion bond respective heat sinks via structured copper strain buffers "directly" to each surface of the semiconductor device wafer thereby eliminating the rather expensive support plate. The term "directly" as used herein signifies that actually such bonds are made to metalized layers situated on the major opposed surfaces of the wafer, and not to the wafer itself. Several high power semiconductor devices including heat sinks attached via structured copper strain buffers thermo-compression diffusion bonded "directly" to a silicon device wafer without use of a tungsten or molybdenum support plate are described and claimed in the aforementioned Glascock et al. patent application. In accordance with the present invention, one method for accomplishing such thermo-compression diffusion bonds "directly" to each side of a semiconductor device wafer unsupported by a support plate is provided. It will be apparent to those skilled in the art that improved electrical and thermal performance are to be gained by the elimination of the tungsten or molybdenum support plate which results from the "direct" diffusion bonding of heat sinks via structured copper strain buffers to both sides of a semiconductor device wafer. My copending patent application, Ser. No. 19,224, filed Mar. 9, 1979 and assigned to the instant assignee, describes and claims a method for "direct" diffusion bonding a heat sink via a structured copper strain buffer to one side of a semiconductor device wafer. My copending patent application, Ser. No. 18,653, filed Mar. 8, 1979 assigned to the instant assignee, describes and claims an improved apparatus and method for "direct" diffusion bonding heat sinks via structured copper strain buffers to both sides of a semiconductor device wafer. It is one object of the present invention to provide a method for thermo-compression diffusion bonding separate structured copper strain buffers "directly" to each of the two opposed surfaces of a semiconductor device wafer without requiring an intermediate support plate to strengthen the wafer. It is a further object of the invention to provide a method for more efficiently removing heat from a semiconductor device wafer. It is another object of the invention to provide a method for thermo-compression diffusion bonding separate structured copper strain buffers to each side of a semiconductor device wafer without causing wafer fracture. BRIEF SUMMARY OF THE INVENTION The present invention is directed to increasing the conduction of heat away from a semiconductor device wafer having structured copper strain buffers respectively bonded to each of the two major opposed surfaces thereof. By "directly" diffusion bonding strain buffers to the wafer, need for the support plate attached to the semiconductor device is eliminated. Briefly, in accordance with one preferred embodiment of the invention, a method for thermo-compression diffusion bonding first and second structured copper strain buffers to a substrateless semiconductor device wafer having two major opposed surfaces and an outer edge surface is provided. A substrateless semiconductor device wafer is defined to be one which has no support plate attached thereto. Each of these major surfaces is smoothened and then coated with respective separate metallic layers. Each metallic layer is coated with a metallization. The first and second structured copper strain buffers each include a bundle of substantially parallel, closely packed strands of copper of substantially equal length having one common end thereof thermo-compression diffusion bonded to a metallic sheet while one common end of the copper strands opposite the metallic sheet of each of the first and second structured copper strain buffers is to be thermo-compression diffusion bonded to each of the two metallized major surfaces of the semiconductor device wafer, respectively. The semiconductor device wafer is sandwiched between the first and second structured copper strain buffers. The surface of each strain buffer opposite its respective metallic sheet is positioned facing each major surface of the wafer, respectively. The first and second structured copper strain buffers extend laterally beyond the lateral extent of the semiconductor device wafer and are positioned so as to overhang the entire outer edge surface of the wafer. The so positioned semiconductor device wafer and structured copper strain buffers are surrounded with an inert atmosphere and squeezed together at high pressure. The semiconductor device wafer and structured copper strain buffers are heated at a temperature within the range of 300° C. to 400° C. while the same are squeezed together. In an alternative embodiment of the invention, first and second structured copper strain buffers are thermocompression diffusion bonded to each of the two metallized major surfaces of a semiconductor device wafer. The outer edge surface of the semiconductor device wafer is beveled preferably prior to sandwiching the semiconductor device wafer between the first and second structured copper strain buffers. The separate metallic layers and metallizations are applied to each of the opposed surfaces of the semiconductor device wafer as previously set forth, but with the metallic layers and metallizations having a lateral extent sufficiently small to avoid overlapping the beveled surface. The metallic layer and metallization on the surface of the wafer which is beveled are axially aligned with each other and with the metallic layer and metallization on the opposite surface of the wafer, which likewise are axially aligned with each other. All metallic layers and metallizations are formed with an equal lateral extent. The semiconductor device wafer is then sandwiched between the first and second strain buffers and the semiconductor device wafer and first and second structured copper strain buffers are squeezed together while being heated in an inert atmosphere, as described above. The metallic sheet of the first structured copper strain buffer is thereafter cut, preferably with a laser beam to remove the portion of the first strain buffer not bonded to the semiconductor device wafer. The beveled edge surface of the wafer is cleaned, typically by sputter etching, and is then passivated. Thermo-compression diffusion bonds are thus formed between the two major opposed surfaces of the beveled semiconductor device wafer and respective first and second structured copper strain buffers without wafer fracture. The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings. DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a thermocompression diffusion bonding press showing materials situated in the press to be bonded together in practicing the invention. FIG. 2 illustrates laser cutting of a portion of a structured copper strain buffer in preparation for passivating the semiconductor device wafer diffusion bonded thereto. FIG. 3 is a top view of the bonded semiconductor device wafer-strain buffer structure shown in FIG. 2 after removal of the portions of the strain buffer cut away by the laser. FIG. 4 is a cross-sectional side view of the wafer-strain buffer structure shown in FIG. 3, after passivation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a diffusion bonding press 10 suitable for thermo-compression diffusion bonding a first structured copper strain buffer 12 and a second structured copper strain buffer 14, respectively, to the opposed major surfaces 16a and 16b of substrateless semiconductor device wafer 16. The outer edge surface 16c of semiconductor device wafer 16 is preferably beveled, as shown in FIG. 1, although the invention encompasses wafers both with and without a beveled outer edge surface. A diffusion bonding press such as press 10 is described in the aforementioned Houston patent application Ser. No. 139,177, the disclosure thereof being incorporated herein by reference. Press 10 is comprised of an upper metallic plate 22 oriented parallel to a lower metallic plate 24 with a space provided therebetween. A metallic pressing block 26 is positioned at the center of the side of upper plate 22 facing lower plate 24. Metallic bolts 28 and 30 pass through respective holes in upper plate 22 and lower plate 24 and are threaded into lower plate 24 to connect the two plates together as illustrated in FIG. 1. Metallic bolts 28 and 30 are comprised of a steel other than stainless steel, while upper plate 22, lower plate 24 and metallic pressing block 26 are comprised of stainless steel. Metallic pressing block 26 may alternatively be comprised of Dural, an aluminum alloy, and other metals having a coefficient of thermal expansion greater than that of steel. To achieve the respective thermo-compression diffusion bonds between strain buffers 12 and 14 and wafer 16, surfaces 16a and 16b are smoothened to remove surface damage therefrom. Such surface damage would otherwise cause nonuniform distribution of pressures within wafer 16 and thus wafer breakage when wafer 16 is subjected to the high pressures employed in the thermo-compression diffusion bonding process of the invention. This step of smoothing may be accomplished, for example, by polishing or etching surfaces 16a and 16b. Metallic layers 31 and 32 are applied to wafer surfaces 16a and 16b, respectively. Each of metallic layers 31 and 32 is comprised of one of such metals as titanium, chromium and nickel. Metallizations 34 and 36 are respectively applied over metallic layers 31 and 32. Each of metallizations 34 and 36 are respectively comprised of one of such metals as copper, gold and silver. These metallic layers and metallizations may be applied to wafer 16 by sputtering or evaporation, for example. The wafer-metallic layer-metallization structure thus formed is sandwiched between structured copper strain buffers 12 and 14. Structured copper strain buffer 12 is comprised of a bundle of substantially parallel, closely packed strands of copper 40 of substantially equal length with one common end thereof thermo-compression diffusion bonded to a metallic sheet 42, typically comprised of copper. The opposite common end of copper strands 40 is positioned in abutment with metallization 34. Structured copper strain buffer 14 is essentially identical to structured copper strain buffer 12 and is comprised of copper strands 50 and metallic sheet 52. The common end of copper strands 50 opposite metallic sheet 52 is positioned in abutment with metallization 36. A layer 54 of nonreactive compactible material is situated in abutment with metallic sheet 42 of structured copper strain buffer 12. Layer 54 may be comprised of glass wool or Glass Fiber Filter paper available from Fisher Scientific Company, Clifton, N.J., or other similarly compactible material. A layer of compactible material 56 preferably comprised of the same material as layer 54 is positioned in abutment with metallic sheet 52 of structured copper strain buffer 14. The combined structure formed by semiconductor device wafer 16, structured copper strain buffers 12 and 14, and metallic layers 31 and 32 and metallizations 34 and 36 disposed therebetween and compactible layers 54 and 56 is positioned in press 10 between pressing block 26 and lower plate 24. A conventional press (not shown) is used to squeeze upper plate 22 and lower plate 24 together and while such pressure is applied to these plates, bolts 28 and 30 are tightened. The thermo-compression diffusion bonds between structured copper strain buffer 12 and wafer 16, and between structured copper strain buffer 14 and wafer 16 are actually formed when press 10 containing the abovedescribed combined structure, illustrated in FIG. 1, is surrounded by an inert atmosphere and heated at a temperature within the range of 300° C. to 400° C., typically 325° C., for approximately 15 minutes to 5 hours. When press 10 is heated in this manner, upper plate 22, lower plate 24 and metallic pressing block 26 expand to a greater total extent than do metallic bolts 28 and 30. Therefore, a force is exerted between pressing block 26 and lower plate 24, resulting in the squeezing of structured copper strain buffers 12 and 14 and semiconductor device wafer 16 together and the thermo-compression diffusion bonding of buffers 12 and 14 to wafer 16. The now-formed strain buffer-wafer assembly 60 is removed from press 10 by loosening bolts 28 and 30. Although reference is made herein to the thermo-compression diffusion bonding of strain buffer 12 to wafer 16 and strain buffer 14 to wafer 16 for simplicity of description, those skilled in the art will appreciate that the actual thermo-compression diffusion bonds are formed at the interface between the common end of copper strands 40 and metallization 34, and at the interface between the common end of copper strands 50 and metallization 36. During thermo-compression diffusion bonding, substrateless semiconductor device wafer 18 is subjected to high pressures, specifically, 20,000 psi to 50,000 psi. If this force is not purely compressive, that is, if semiconductor device wafer 16 is subjected to bowing or tensile forces, wafer 16 will likely fracture, resulting in a damaged semiconductor device. It is thus extremely important that uniform high pressure be applied over the entire wafer 16. Prior methods of thermo-compression diffusion bonding used a support plate attached to the semiconductor device wafer to enable the wafer to withstand some degree of bowing forces and nonuniform pressure without fracture. When attempting thermo-compression diffusion bonding of members to a "substrateless" semiconductor device wafer, it is important that the surfaces of the members to be bonded together be flat and parallel to each other and to the opposed facing surfaces of lower plate 24 and metallic pressing block 26. To solve the problem of bowing forces being generated near the edge surface of wafer 16 during thermo-compression diffusion bonding as would occur if strain buffers 12 and 14 did not extend over the entire lateral extent of wafer 16, the lateral extent of structured copper strain buffers 12 and 14 is made greater than the lateral extent of wafer 16 such that buffers 12 and 14 overhang wafer 16 around the entirety of its edge surface. Layers of compactible material 54 and 56 are positioned as described above to assure that during thermocompression diffusion bonding, structured copper strain buffer 12 does not adhere undesirably to pressing block 26 and to assure that structured copper strain buffer 14 similarly does not bond to lower plate 24. Use of such layers of compactible material helps assure the creation of uniform, substantially void-free diffusion bonds. Voids in diffusion bonds may result when a thermo-compression diffusion bond between a compliant metallic member (such as a structured copper strain buffer) and another member having some degree of surface irregularity is attempted. When compressed, the layers of compactible material fill in the irregularities in the surface of the respective structured copper strain buffers allowing the diffusion bonding press 10 to apply a more evenly distributed pressure to the members which are to be bonded together. Use of layers of compactible material 54 and 56 is preferable but not essential to practice of the method of the invention. A method employing such layers of compactible material to substantially prevent the creation of voids in materials thermo-compression diffusion bonded together is described and claimed in Houston et al., Ser. No. 927,346, filed July 24, 1978 and assigned to the instant assignee, the disclosure thereof being incorporated herein by reference. If semiconductor device wafer 16 is of the nonbeveled variety, no further processing in accordance with the invention is required. However, if wafer 16 includes a beveled outer edge surface 16c, as illustrated, it is desirable that surface 16c be cleaned and passivated to protect it from external contamination. As shown in FIG. 2, beveled edge surface 16c lies recessed under structured copper strain buffer 12 and is thus inaccessible for cleaning and passivation purposes. It would be undesirable to passivate beveled surface 16c prior to thermo-compression diffusion bonding since the additional thickness of the passivant, which would likely become affixed to the outer edge of wafer surfaces 16a and 16b would cause uneven pressure on the wafer during such diffusion bonding and likely result in fracturing the wafer. Therefore, passivation of beveled surface 16c is achieved in the following manner. Prior to sandwiching wafer 16 between structured copper strain buffers 12 and 14, metallic layers 31 and 32, applied to major surfaces 16a and 16b, respectively, of wafer 16, are formed with a lateral extent sufficiently small so as to avoid overlapping beveled surface 16c. That is, the lateral extent of layers 31 and 32 may be equal to or less than the lateral extent of surface 16a. Metallizations 34 and 36 are thereafter applied over metallic layers 31 and 32, respectively, with lateral extents equal to those of metallic layers 31 and 32, all of the above-mentioned lateral extents being equal and axially aligned with each other, as shown in FIG. 2. When the thermo-compression diffusion bonding process is carried out upon the metallized wafer structure 16, the common end of copper strands 40 opposite metallic sheet 42 of strain buffer 12 becomes thermo-compression diffusion bonded only to the metallized portions of surface 16a. Similarly, the common end of copper strands 50 opposite metallic sheet 52 of strain buffer 14 diffusion bonds only to metallized portions of surface 16b. A laser device 62 such as a pulsed laser, typically having a peak pulsed power of 16 KW although not limited thereto, generates a beam of coherent light which is directed along a selected path on metallic sheet 42 of strain buffer wafer assembly 60, fabricated as previously described, so as to form an incision 64 in sheet 42 and thus allow the removal of most of the portion of strain buffer 12 not bonded to wafer metallization 34. The portion of structured copper strain buffer 12 outside incision 64 is removed to form wafer-buffer structure 70 shown in FIG. 3. The remaining portion of strain buffer 12 is designated strain buffer 12'. Beveled edge surface 16c is thus made accessible for cleaning and passivation. Chemically etching the surface of a beveled semiconductor device wafer is a method for wafer cleaning well known in the art. However, such an etching step, if applied to wafer-buffer structure 70 would result in the undesirable chemical attack of the structured copper strain buffers 12 and 14 by the etchant. Rather, beveled surface 16 is subjected to sputter etching to remove contaminants therefrom prior to passivation. Subsequently, beveled surface 16c is coated with a passivation layer 82 comprised of one of the many passivation materials known in the art, polyimide siloxane, for example, as illustrated in FIG. 4. To complete the device thus formed, heat sinks (not shown) are respectively attached to metallic layers 42 and 52 of strain buffers 12' and 14. This is preferably accomplished by thermo-compression diffusion bonding during the course of attachment of strain buffers 12 and 14 to wafer 16 or at a later time. Although heat sink attachment may be accomplished by other means of joining metals together, soldering, for example, thermocompression diffusion bonding is preferred because it inherently achieves superior thermal conductivity between the joined metallic members. Practice of the invention is not limited to the particular circular geometries shown for the wafers, strain buffers, and various other layers depicted in the drawings for purposes of example. Rather, other geometric forms of these members such as squares, rectangles, polygons, etc., may alternatively be used in practicing of the invention. The foregoing describes a method for thermo-compression diffusion bonding separate structured copper strain buffers directly to each of the two major opposed surfaces, respectively, of substrateless semiconductor device wafer. Such bonding is achieved without wafer fracture. The method accommodates both beveled and nonbeveled semiconductor device wafers. While only certain preferred features of the invention have been shown by way of illustration, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

A method is provided for thermo-compression diffusion bonding first and second structured copper strain buffers, respectively, directly to the two opposed surfaces of a substrateless semiconductor device wafer. The expensive tungsten or molybdenum support plate conventionally used to provide structural integrity to the relatively fragile semiconductor device wafer is thus eliminated. The method includes sandwiching the semiconductor device wafer between copper strand type strain buffers each having a lateral extent greater than the lateral extent of the wafer, diffusion bonding the strain buffers to the semiconductor device via first and second metallic coating layers, and removing most of the overhanging portions of the buffer which are not bonded to the wafer. A step of etching and passivating the edges of the wafer is also disclosed.

BACKGROUND OF THE INVENTION Diborane (B 2 H 6 ) is a versatile reagent with broad applications in organic and inorganic syntheses. Because diborane is a pyrophoric gas having a flash point of about −90° C. and an autoignition temperature of about 38° C. to 51° C., borane complexes with Lewis bases are typically used instead, as they are more convenient to handle. Numerous examples of these borane complexes for use in the synthesis of pharmaceuticals and other industrial applications are well known in the art. Borane-tetrahydrofuran complex (sometimes referred to as (“BTHF” or “BTHF complex”) is one of the more widely used borane-Lewis base complexes for synthetic applications, such as hydroboration of carbon-carbon double and triple bonds, and reduction of various functional groups. Problematically, BTHF solutions having a concentration in excess of about 2.0 moles per liter readily release diborane. In part because of instability issues, therefore, BTHF complex has been commercially available only as low concentration solutions for a number of years. Under the United States Department of Transportation (“DOT”) regulations, transportation of a package containing a material which is likely to decompose with a self-accelerated decomposition temperature (SADT) of 50° C. or less with an evolution of a dangerous quantity of heat or gas when decomposing is prohibited unless the material is stabilized or inhibited in a manner to preclude such evolution Because of the intrinsic instability and low autoignition temperature, BTHF solutions known in the art having a BTHF concentration in excess of about 1 mole per liter generally cannot meet the SADT mandated by the DOT. Aside from resulting in unacceptable SADT temperatures, diborane exhibits high vapor pressure at room temperature resulting in overpressurization of storage containers. Moreover, diborane can attack the tetrahydrofuran (“THF”) cyclic ether linkage causing ring opening thereby resulting in less pure BTHF and concomitant heat generation and container pressurization. Another problem associated with BTHF complexes is short shelf life, especially at temperatures at or above normal room temperature of about 25° C. BTHF complexes can decompose during shipping or in storage if they are not stabilized properly, or are shipped at elevated temperature. For instance, as described in U.S. Pat. No. 6,048,985 to Burkhardt et al., the assay of a 2 molar solution of BTHF stored at room temperature (i.e., 20° C. to 25° C.) dropped from about 98% to about 16% over a period of 110 days. In U.S. Pat. No. 3,634,277, Brown disclosed stabilizing BTHF from ring-opening ether cleavage of the tetrahydrofuran (“THF”), to some extent, with borohydride. In each of Brown's examples, however, BTHF solutions having concentrations of 1.5 to 2.0 M BTHF experienced significant decomposition of the BTHF in shelf-life/stability experiments conducted at ambient temperature for eight weeks. In addition, stabilization of BTHF with sodium borohydride does not significantly increase the SADT temperature to 50° C. or above. Also, NaB 2 H 7 , a possible by product from such stabilized solutions formed by the reaction of NaBH 4 with borane, is relatively insoluble in THF and may drop out of solution as a solid precipitate thereby causing storage and material transfer problems. This is true for BTHF prepared by in situ methods or by passing highly pure diborane gas into the THF. In the interest of conservation of resources and efficient use of reactor vessels, one would like to conduct reactions at the highest concentration possible for a particular reaction. In that regard, the low concentration of the BTHF leads to low reactor loading and inefficient use of equipment. There are several reports in the literature, however, that solutions of BTHF of greater than 1 mole per liter are unavailable as a result of the instability of such solutions. See, for example, H. C. Brown, P. Heim, N. M. Yoon JACS, 92, 1637-1646 (1970); C. F. Lane Chem. Rev., 76, 773-799 (1976); H. C. Brown, M. C. Desai, P. K. Jadhav JOC, 47, 5065-5069 (1982); M. Follet Chem. And Industry., 123-128; and K. Smith, Chem. and Industry 1987, 603-611 (1986). Borane reagents other than BTHF complex are available in more concentrated form, but each has inherent disadvantages. For example, sulfide boranes are highly concentrated but suffer from noxious odors and amine-boranes known in the art are less reactive than BTHF. In addition, such complexing agents (amine or sulfide) are often difficult to remove from the desired product. SUMMARY OF THE INVENTION Among the various aspects of the present invention are stabilized borane-tetrahydrofuran complex solutions, processes for their preparation, and methods of storing and transporting those solutions. Briefly, therefore, the present invention is directed to a solution containing a borane-tetrahydrofuran complex, tetrahydrofuran and a stabilizer. The stabilizer is selected from the group consisting of amines, sulfides, phosphines, aminoborohydrides, borates, and combinations thereof. The concentration of the borane-tetrahydrofuran complex in the solution is at least about 0.5 moles per liter, and the molar ratio of the borane-tetrahydrofuran complex to the stabilizer is at least 10:1. The present invention is further directed to a process for the preparation of a stabilized borane-tetrahydrofuran complex in a solution containing tetrahydrofuran. The process comprises forming a solution containing borane-tetrahydrofuran complex and a solvent system comprising tetrahydrofuran, the concentration of the borane-tetrahydrofuran complex in the solution being at least about 0.5 moles per liter. A stabilizer is combined with the solvent system in a molar ratio of the borane-tetrahydrofuran complex to the stabilizer in the solution of at least 10:1, the stabilizer being selected from the group consisting of amines, sulfides, phosphines, aminoborohydrides, borates, and combinations thereof. The process steps can be carried out in any order. The present invention is further directed to a method of storing and transporting a solution containing at least about 0.5 moles per liter of a borane-tetrahydrofuran complex in solution in a solvent system comprising tetrahydrofuran. The solution further comprises a stabilizer selected from the group consisting of amines, sulfides, phosphines, aminoborohydrides, borates, and combinations thereof wherein the molar ratio of the borane-tetrahydrofuran complex to the stabilizer is at least 10:1. The method comprises sealing the liquid borane-tetrhydrofuran complex solution in a container having a storage volume of at least 0.10 liters and transporting the sealed container to another location. In one embodiment, the ratio of the surface area at the gas-liquid interface within the container to the volume of liquid in the container is at least about 2 cm 2 per liter. The present invention is further directed to a method of storing and transporting a solution containing at least about 0.5 moles per liter of a borane-tetrahydrofuran complex in a solvent system containing tetrahydrofuran. The solution is sealed in a container having a free space occupied by a gas. The ratio of the surface area of the gas-solution interface to the volume of the solution in the sealed container is about 2 cm 2 per liter to about 200 cm 2 per liter. The sealed container can then be transported. Other objects and features of this invention will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph of the mole percent borane-THF remaining (by 11 B NMR) in solution versus time in hours for unstabilized and stabilized 1 mole per liter borane-THF solutions held at a temperature of 50° C. FIG. 2 is a graph of the mole percent borane-THF remaining (by 11 B NMR) in solution versus time in days for unstabilized and stabilized 1 mole per liter borane-THF solutions held at a temperature of 22° C. FIG. 3 is a graph of heat generation/loss versus temperature for various sized containers containing a 1M borane-THF solution stabilized with 1,2,2,6,6-Pentamethylpiperidine or NaBH 4 (comparative). The tangential lines represent the heat loss pattern for the containers, with the intersection of those lines with the X-axis representing the critical ambient temperature of the containers. FIG. 4 is a graph of heat generation/loss versus temperature for various sized containers containing a 1M borane-THF solution stabilized with N-isopropyl-N-methyl-t-butylamine or NaBH 4 (comparative). The tangential lines represent the heat loss pattern for the containers, with the intersection of those lines with the X-axis representing the critical ambient temperature of the containers. DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, stabilized BTHF solutions having a THF concentration of at least about 0.5 molar are provided. As compared to BTHF solutions known in the art, such stabilized solutions have an increased shelf life at temperatures of at least about 5° C., an elevated SADT temperature of at least about 50° C., or both. In general, temperature stability or SADT temperature elevation is achieved by including in the THF solution, a stabilizer selected from the group consisting of amines, sulfides, phosphines, aminoborohydrides, borates, and combinations thereof. Preferred amines include non-cyclic and cyclic secondary and tertiary amines, amine oxides, and metal amides. Preferred phosphines include the non-cyclic and cyclic secondary and tertiary forms, and phosphine oxides. Preferred sulfides include the secondary non-cyclic and cyclic forms, and sulfoxides. Preferred borates include boric acid esters and tetralkoxyborate salts. In particular, such stabilizers offer particular utility in stabilizing THF solutions containing at least 0.5 moles per liter of dissolved BTHF. Typically, the stabilized THF solution has a dissolved BTHF concentration not in excess of 2.5M. In one preferred embodiment, the stabilized solution has a dissolved BTHF concentration of about 1M to about 2.5M; in another preferred embodiment, the stabilized solution has a dissolved BTHF concentration of about 1M to about 2M; in another preferred embodiment, the stabilized solution has a dissolved BTHF concentration of about 1M to about 1.5M; in another preferred embodiment, the stabilized solution has a dissolved BTHF concentration of about 1.5M to about 2.5M; in yet another preferred embodiment, the stabilized solution has a dissolved BTHF concentration of about 1.5M to about 2M; and in yet another preferred embodiment, the stabilized solution has a dissolved BTHF concentration of about 2M to about 2.5M. Without being bound to any particular theory, it has been proposed that the stabilizers scavenge diborane through the formation of a stabilizer-diborane complex having a dynamic equilibrium in THF solution sufficient to deliver borane back to THF and reform BTHF. Stabilization can be represented by the following reaction scheme: Regardless of mechanism, the stabilizers of the present invention yield BTHF complex solutions having a greater SADT temperature, longer shelf life at ambient temperature, or both, than stabilized BTHF solutions previously known in the art. In general, a molar ratio excess of BTHF to stabilizer(s) in the THF solution is preferred. Preferably, the molar ratio of BTHF to stabilizer(s) is greater than about 10:1, respectively. More preferably, the molar ratio of BTHF to stabilizer(s) in the THF solution is between 10:1 and 10,000:1, respectively. In one preferred embodiment, the molar ratio of BTHF to stabilizer(s) in the THF solution is about 50:1 to about 1000:1, respectively. In another preferred embodiment, the molar ratio of BTHF to stabilizer(s) in the THF solution is between 100:1 and 500:1, respectively. The stabilizer(s) of the present invention may be fully dissolved in the THF solution or, alternatively, immobilized onto a polymeric or other solid support, or be present within the matrix of a polymeric or other solid support. Thus, for example, when a secondary or tertiary amine is used as a stabilizer, it may be dissolved in the THF solution; alternatively, it may be immobilized onto or in a resin particle or other solid combined with the THF solution. For example, the stabilizer may be immobilized on a resin particle added to the THF solution or immobilized to the inner wall of a container holding the THF solution. Furthermore, combinations of stabilizers may be used in each of these permutations. Thus, for example, an immobilized secondary or tertiary amine may be used in combination with one or more dissolved stabilizers selected from the group consisting of secondary or tertiary amines, sulfides, phosphines, borates and aminoborohydrides. Regardless, it is generally preferred that the molar ratio of BTHF to all such stabilizer(s) in the THF solution (regardless of whether they are immobilized or dissolved) be between 10:1 and 10,000:1, respectively. In one embodiment, the stabilizer consists of only the secondary or tertiary amine; that is, the stabilizer does not additionally comprise an aminoborohydride, metal amide, sulfide, phosphine, borate, or borohydride. In another embodiment, a combination of two or more of these stabilizers is used. In one preferred embodiment, the THF solution contains an amine BTHF stabilizer such as a non-cyclic secondary amine, tertiary-amine, amine-N-oxide, aminoborane or metal amide. Preferred non-cyclic secondary and tertiary amines are represented by chemical formula (Ia): preferred amine-N-oxides are represented by chemical formula (Ib): preferred aminoboranes are represented by chemical formula (Ic): and preferred metal amides are represented by chemical formula (Id): R 1 R 2 N − M +   (Id) wherein, for tertiary amines and amine oxides, R 1 , R 2 and R 3 are independently selected from aryl, heteroaryl, straight or branched chain alkyl, alkene or alkoxy having 1 to 8 carbon atoms, cycloalkyl having 3 to 8 carbon atoms, and tri-substituted silyl. For secondary amines and amine oxides, one of R 1 , R 2 or R 3 as defined above is hydrogen. For metal amides, R 1 and R 2 are independently selected from aryl, heteroaryl, straight or branched chain alkyl, alkene or alkoxy having 1 to 8 carbon atoms, cycloalkyl having 3 to 8 carbon atoms, and tri-substituted silyl. M + is any suitable counterion with metals such as sodium, potassium or lithium being preferred. A preferred aryl is phenyl (C 6 H 5 ). The silyl may be substituted with the groups independently selected from hydrogen, phenyl, straight or branched chain alkyl, alkene or alkoxy having 1 to 8 carbon atoms, and cycloalkyl having 3 to 8 carbon atoms. A preferred silyl is trimethylsilyl. Secondary and tertiary amines of formula (Ia) are known in the art. See for example U.S. Pat. Nos. 5,481,038, 5,543,569 and 6,248,885 to Brown, all of which are incorporated by reference. Representative non-cyclic tertiary amine stabilizers are indicated in Table 1. Representative amine oxides can be derived from Table 1 where R 1 , R 2 and R 3 can be any one of the listed moieties. Representative metal amides can be derived from Table 1 where R 1 and R 2 can be any one of the listed moieties. Representative non-cyclic secondary amine stabilizers can be derived from the compounds of Table 1 where any one of R 1 , R 2 and R 3 is hydrogen instead of the listed moiety. TABLE 1 Stabilizer R 1 R 2 R 3 1 C 6 H 5 i-butyl methyl 2 C 6 H 5 i-butyl ethyl 3 C 6 H 5 i-butyl i-butyl 4 C 6 H 5 i-butyl n-propyl 5 C 6 H 5 i-propyl methyl 6 C 6 H 5 i-propyl ethyl 7 C 6 H 5 i-propyl n-propyl 8 C 6 H 5 i-propyl i-propyl 9 t-butyl —CH 2 CH 2 OCH 2 CH 2 —CH 2 CH 2 OCH 2 CH 2 10 t-butyl ethyl ethyl 11 t-butyl n-propyl n-propyl 12 t-butyl —CH 2 CH 2 OCH 3 —CH 2 CH 2 OCH 3 13 t-butyl i-butyl i-butyl 14 t-butyl methyl i-butyl 15 t-butyl methyl i-propyl 16 t-butyl ethyl i-butyl 17 t-butyl n-propyl i-butyl 18 t-butyl ethyl i-propyl 19 t-octal methyl methyl 20 t-octal ethyl methyl 21 t-octyl —CH 2 CH 2 OCH 2 CH 2 —CH 2 CH 2 OCH 2 CH 2 22 t-octal ethyl ethyl 23 t-octal i-butyl methyl 24 t-octal n-propyl -propyl 25 i-propyl i-propyl i-butyl 26 i-propyl i-propyl methallyl 27 t-octyl n-propyl n-propyl 28 i-propyl i-propyl i-propyl 29 n-butyl ethyl ethyl 30 i-propyl i-propyl sec-butyl In another preferred embodiment, the secondary or tertiary amine is a six or five membered cyclic amine of chemical formulae (II) and (III), respectively: wherein, for the six-membered ring of formula (II), at least one atom and no more than three atoms at positions 1-6 are nitrogen, the ring can include an oxygen, phosphorous or sulfur heteroatom, and the remaining ring atoms are carbon. For the five-membered ring of formula (III), at least one atom and no more than three atoms at any one of positions 1-5 are nitrogen, the ring can contain an oxygen, phosphorous or sulfur heteroatom, and the remaining ring atoms are carbon. The rings of formulae (II) or (III) can be unsaturated, partially unsaturated, or completely saturated. In the case of nitrogen ring atoms, only R xa (where x is any one of 1-6 for rings of formula (II) and 1-5 for rings of formula (III)) is present at that atom, and where the ring is partially unsaturated or completely saturated, the nitrogen atom R xa substituent can represent a shared electron or electron pair. For carbon ring atoms, in the case of unsaturated rings, both R xa and R xb are present at that atom, and where the ring is partially unsaturated or completely saturated one of the carbon atom R xa or R xb substituent can represent a shared electron or electron pair. Preferred six-membered rings include substituted or unsubstituted piperidine, piperazine, pyridine, pyrazine, pyridazine and pyrimidine. Preferred five-membered rings include substituted or unsubstituted 1H-Pyrrole, pyrrolidine, 3-pyrroline, imidazole, pyrazole, 2-pyrazoline and triazole. For rings of formula (II), R 1a through R 6b are independently selected from a shared electron, electron pair, hydrogen, straight or branched chain alkyl, alkene or alkoxy having 1 to 8 carbon atoms, and cycloalkyl having 3 to 8 carbon atoms. For rings of formula (III), R 1a through R 5b are independently selected from a shared electron, electron pair, hydrogen, straight or branched chain alkyl, alkene or alkoxy having 1 to 8 carbon atoms, and cycloalkyl having 3 to 8 carbon atoms. An example of a cyclic stabilizer is 1,2,2,6,6-pentamethylpiperidine (stabilizer compound 31). Secondary and tertiary amines can also be cyclic amines represented by the three and four membered rings chemical formulae (IV) and (V), respectively: wherein, for the three-membered ring of formula (IV), at least one atom and no more than two atoms at positions 1-3 are nitrogen, the ring can contain an oxygen, phosphorous or sulfur heteroatom, and the remaining ring atoms are carbon. For the four-membered ring of formula (V), at least one atom and no more than two atoms at any one of positions 1-4 are nitrogen, the ring can contain an oxygen, phosphorous or sulfur heteroatom, and the remaining ring atoms are carbon. The rings of formulae (IV) or (V) can be unsaturated, partially unsaturated, or completely saturated. In the case of nitrogen ring atoms, only R xa (where x is any one of 1-3 for rings of formula (IV) and 1-4 for rings of formula (V)) is present at that atom, and where the ring is partially unsaturated or completely saturated, the nitrogen atom R xa substituent can represent a shared electron or electron pair. For carbon ring atoms, in the case of unsaturated rings, both R xa and R xb are present at that atom, and where the ring is partially unsaturated or completely saturated one of the carbon atom R xa or R xb substituent can represent a shared electron or electron pair. The rings of formulae (IV) and (V) can be substituted or unsubstituted. A preferred three-membered rings is ethyleneimine. For rings of formula (IV), R 1a through R 3b are independently selected from a shared electron, electron pair, hydrogen, straight or branched chain alkyl, alkene or alkoxy having 1 to 8 carbon atoms, and cycloalkyl having 3 to 8 carbon atoms. For rings of formula (V), R 1a through R 4b are independently selected from a shared electron, electron pair, hydrogen, straight or branched chain alkyl, alkene or alkoxy having 1 to 8 carbon atoms, and cycloalkyl having 3 to 8 carbon atoms. In an alternative embodiment, formulae (II) to (IV) may include ring atoms other than carbon and nitrogen. Thus, for example, formulae (II) to (IV) may include an oxygen, phosphorous or sulfur heteroatom. In one embodiment, therefore, the heterocycle may be thiazole or oxazole. In another embodiment, aminoborohydrides suitable for use as BTHF stabilizers are represented by formula (VI): R 1 R 2 R 3 NH 4 B − M +   (VI) where R 1 , R 2 and R 3 are independently selected from straight or branched chain alkyl, alkene or alkoxy having 1 to 8 carbon atoms, and cycloalkyl having 3 to 8 carbon atoms and M is a metal cation. Suitable metal cations include, for example, lithium, sodium and potassium. Aminoborohydrides of formula (VI) are known in the art. See for example U.S. Pat. No. 5,466,798 to Singaram, et al. In another preferred embodiment, sulfides suitable for use as BTHF stabilizers are represented by sulfides of formula (VIIa) and sulfoxides of formula (VIIb): SR 4 R 5 (VIIa); S(O)R 4 R 5   (VIIb) wherein R 4 and R 5 are independently straight or branched chain alkyl, alkene or alkoxy having from 1 to 8 carbon atoms. In one embodiment the alkoxy is of the formula (CH 2 CH 2 O) n where n is 1 to 3. Sulfides of formula (VIIa) are known in the art. See, for example, U.S. Pat. Nos. 5,504,240 and 5,567,849 to Brown, both of which are incorporated by reference. Sulfoxides of formula (VIIb) are known in the art. See, for example, U.S. Pat. No. 4,029,712 to Tsuchihashi et al., which is incorporated by reference. Alternatively, R 4 and R 5 and the sulfur atom can form a substituted or unsubstituted heterocyclic ring structure containing from 3 to 8 atoms. One such preferred ring is thiophene. The heterocyclic ring can be substituted with one or more groups defined for R 1 above. Representative sulfide stabilizers of formula (VIIa) are indicated in Table 2 below. Representative sulfoxide stabilizers of formula (VIIb) also have the substituents as indicated in Table 2. TABLE 2 Stabilizer R 4 R 5 32 i-amyl ethyl 33 i-amyl methyl 34 i-amyl t-butyl 35 i-amyl i-amyl 36 2-methoxyethyl 2-methoxyethyl 37 2-methoxyethyl ethyl 38 t-butyl ethyl 39 methyl methyl 40 (CH 2 CH 2 O) 2 ethyl 41 (CH 2 CH 2 O) 2 t-butyl 42 (CH 2 CH 2 O) 2 i-amyl 43 (CH 2 CH 2 O) 3 ethyl 44 (CH 2 CH 2 O) 3 t-butyl 45 (CH 2 CH 2 O) 3 i-amyl In still another preferred embodiment, phosphines suitable for use as BTHF stabilizers are represented by formulae (VIII), (IX) and (X): For the phosphine of formula (VII), R 6 , R 7 and R 8 are independently selected from hydrogen, straight or branched chain alkyl or alkyne having from 1 to 14 carbon atoms, substituted or unsubstituted cycloalklyl having from 3 to 8 carbon atoms, and substituted or unsubstituted phenyl, provided, however, only one of R 6 , R 7 and R 8 is hydrogen. Preferred cycloalkyls are cyclopentyl and cyclohexyl. Preferred substituted phenyls are xylyl (dimethylbenzene) and tolyl(methylbenzene). Representative phosphine stabilizers of formula (VIII) are indicated in Table 3 below. TABLE 3 Stabilizer R 6 R 7 R 8 46 H i-butyl i-butyl 47 H phenyl phenyl 48 tetradecene-1 phenyl phenyl 49 H ethyl ethyl 50 tetradecene-1 ethyl ethyl 51 n-butyl n-butyl n-butyl 52 H n-butyl n-butyl 53 phenyl phenyl phenyl 54 xylyl xylyl xylyl 55 tolyl tolyl tolyl 56 allyl allyl i-butyl 57 allyl allyl cyclohexyl 58 allyl allyl sec-butyl 59 allyl allyl hexyl 60 allyl allyl cyclopentyl For the phosphine of formula (IX), R 9 , R 10 , R 11 , R 12 and R 13 are independently selected from hydrogen, straight or branched chain alkyl or alkyne having from 1 to 14 carbon atoms, substituted or unsubstituted cycloalklyl having from 3 to 8 carbon atoms, and substituted or unsubstituted phenyl. Only one or two of R 9 , R 10 , R 11 , R 12 and R 13 can be hydrogen. Preferred cycloalkyls are cyclopentyl and cyclohexyl. Preferred substituted phenyls are xylyl and tolyl. A representative phosphine stabilizer of formula (IX) is 1,1,3,3-tetramethylbutylphosphine (stabilizer compound 61). For the phosphine oxides of formula (X), R 14 , R 15 and R 16 are independently selected from hydrogen, straight or branched chain alkyl or alkyne having from 1 to 14 carbon atoms, substituted or unsubstituted cycloalklyl having from 3 to 8 carbon atoms, and substituted or unsubstituted phenyl. Only one of R 6 , R 7 and R 8 can be hydrogen. Preferred cycloalkyls are cyclopentyl and cyclohexyl. Preferred substituted phenyls are xylyl and tolyl. Representative phosphine oxide stabilizers of formula (X) have the substituents as indicated in Table 3 above except where R 6 , R 7 and R 8 as indicated in that table are instead R 14 , R 15 and R 16 , respectively. Alternatively, any two of R 6 -R 8 , R 9 -R 13 or R 14 -R 16 and the phosphorus atom can form a substituted or unsubstituted heterocyclic phosphine ring structure containing from 3 to 8 atoms. Phosphine rings are known in the art. See, for example, U.S. Pat. Nos. 4,503,178 to Green and 6,545,183 B1 to Berens, both of which are incorporated by reference. The phosphine ring can be substituted with any of the groups defined for R 1 above. Phosphines of formulae (VIII), (IX) and (X) are known in the art. See, for example, U.S. Pat. Nos. 4,008,282 to Townsend et al., 4,390,729 to Oswald, 5,100,854 to Maeda et al., 5,250,736 to Micklethwaite et al., 5,260,485 to Calbick et al. and 5,663,419 to Sugiya et al., all of which are incorporated by reference. In yet another embodiment, the stabilizer is a borate. Without being bound to any particular, it has been proposed that these stabilizers react/exchange with borane according to the following reaction scheme: wherein free borane (BH 3 ) is scavenged thereby stabilizing BTHF assay and increasing the SADT temperature. The borate stabilizer, for example, may be represented by formulae (XI) or (XII): wherein R 17 , R 18 , R 19 and R 20 are independently selected from an straight or branched chain alkyl or alkenyl having from 1 to 8 carbon atoms. A sodium counterion is indicated for formula (XII), but any suitable metallic counterion, such as potassium, is suitable for use. A representative borate-based stabilizer of formula (XI) is B(OCH 2 CH 2 CH 2 CH 3 ) 3 (stabilizer compound 62). As previously noted, the stabilizers of the present invention may optionally be supported on or in a polymer matrix, or on or in an inert carrier such as titanium dioxide, silicone dioxide, alumina, carbon or zeolite. Advantageously, a polymer matrix possesses both barrier properties and structural integrity. Suitable polymers include, for example, polyolefin, polyvinyl chloride, nitrile, polyethylene terephthalate (e.g., Mylar® or “PET”), polyurethane, polystyrene, polytetrafluoroethylene (e.g., Teflon® or “PTFE”), silicone rubber and polyvinylidene chloride. The stabilizer can bound to the polymer or carrier at any one of the positions indicated by R 1 through R 20 and R 1a through R 6b , or at a substituted group designated by any of R 1 through R 20 and R 1a through R 6b . Alternatively, any of the stabilizers of the present invention can be included, such as by adsorption or absorption, within the matrix of a porous polymer or inert carrier. The stabilizer is useful for the storage and transportation of BTHF solutions, as well as for the return of substantially empty BTHF containers for refilling. The stabilizer can be included in the BTHF solution in a variety of ways. For instance, first, a stabilizer that is essentially soluble in or miscible with THF can be added to the BTHF solution. Second, a substantially insoluble stabilizer or stabilizer matrix can be used. In the second case, the stabilizer can be isolated within the BTHF storage container to prevent the stabilizer from settling out of solution. Suitable isolation methods include, for example: coating the inside of the storage container or a container insert with the stabilizer; placing the stabilizer within a storage container insert barrier device that is permeable to gas and liquid, but is essentially impermeable to the insoluble stabilizer, such as, for example a perforated sphere or pipe, shaped or formed screen, or micro-perforated sealed bag. Third, stabilizers can be isolated from the storage container as described above to enable a time-release addition to the BTHF solution. Advantageously, container stabilizer inserts facilitate ease of introduction and removal of the stabilizer to and from the storage container. It is noted that the container stabilizer isolation methods are not limited to substantially insoluble and sparingly soluble stabilizers, but can also be used to contain essentially soluble or miscible stabilizers thereby achieving the benefits of time release and ease of introduction to the BTHF solution. Storage vessel geometry can affect the rate of decomposition of both stabilized and unstabilized BTHF solutions. In particular, BTHF decomposition rate has been found to vary positively, and linearly, with the surface area of the BTHF solution exposed to the container vessel void volume. For containers of similar volume, tall vertical vessels having reduced diameter are preferred over shorter vessels having a greater diameter. Therefore, a storage vessel having dimensions selected to minimize the contained BTHF solution surface area to volume ratio are preferred over vessels of similar volume but having dimensions that yield a higher surface area to volume ratio. Moreover, it is preferred to store both stabilized and unstabilized BTHF solutions in vertical vessels rather than horizontal vessels because the surface area interface between the BTHF solution and the vessel gaseous void volume is minimized. EXAMPLES The following examples will illustrate the various features of the present invention. Example 1 A stock solution of BTHF was prepared and stored in a cooler. An aliquot was diluted to a 1.0 molar solution for an individual study (except where other concentrations are indicated). Selected stabilizers at the indicated concentrations were added and the resulting test solutions were sealed in NMR tubes. The tubes were heated to 50° C. and maintained at that temperature during the course of the experiment. BTHF assay was determined and reported at 24, 48 and 72 hours by 11 B NMR. Where indicated, a 1.5 molar solution of BTHF obtained by diluting a stock solution aliquot, was evaluated for stability. The results, reported as percent BTHF-complex remaining in solution, are indicated in Table 4 below. FIG. 1 is a graph of the mole percent borane-THF remaining in solution versus time in hours for an unstabilized 1 mole per liter borane-THF solution and 1 mole per liter BTHF solutions stabilized with 0.005 moles per liter of NaBH 4 and stabilizer 15, respectively, held at a temperature of 50° C. FIG. 2 is a graph of the mole percent borane-THF remaining in solution versus time in days for an unstabilized 1 mole per liter borane-THF solution and 1 mole per liter BTHF solutions stabilized with 0.005 moles per liter of NaBH 4 and stabilizer 15, respectively, held at a temperature of 22° C. TABLE 4 24 48 72 Description hours hours hours unstabilized 1.0M BTHF a 82% b 59% 39% unstabilized 1.5M BTHF 71% 38% 19% <0.005M NaBH 4 in 1.0M BTHF 81% 55% 36% 0.005M NaBH 4 in 1.0M BTHF a 90% 66% 45% 0.01M NaBH 4 in 1.0M BTHF 91% 69% 47% 0.005M LiBH 4 in 1.0M BTHF 89% 64% 43% 0.005M KBH 4 in 1.0M BTHF 84% 59% 40% 0.005M Stabilizer 6 in 1.0M BTHF 83% 65% 48% 0.005M Stabilizer 8 in 1.0M BTHF 85% 65% 49% 0.01M Stabilizer 8 in 1.0M BTHF 86% b 70% 52% 0.005M Stabilizer 15 in 1.0M BTHF a 89% 79% 67% 0.01M Stabilizer 15 in 1.0M BTHF 92% 77% 72% 0.025M Stabilizer 15 in 1.0M BTHF a 87% 74% 61% 0.01M Stabilizer 15 in 1.5M BTHF 87% 68% 49% 0.005M Stabilizer 16 in 1.0M BTHF 83% 59% 43% 0.005M Stabilizer 22 in 1.0M BTHF 88% 73% 59% 0.005M Stabilizer 25 in 1.0M BTHF 85% 65% 49% 0.005M Stabilizer 29 in 1.0M BTHF 81% b 55% 36% 0.01M Stabilizer 29 in 1.0M BTHF 83% 58% 39% 0.005M Stabilizer 31 in 1.0M BTHF a 92% 78% 64% 0.01M Stabilizer 31 in 1.5M BTHF 85% 63% 45% 0.005M Stabilizer 39 in 1.0M BTHF 83% 57% 37% 0.005M Stabilizer 62 in 1.0M BTHF 82% 57% 39% 0.005M pyridine-SiO 2 in 1.0M BTHF 81% 58% 39% a Results are an average of multiple experiments b Results are an estimation from 20 hours Stabilizers 6, 8, 15, 22, 25 and 31 showed increased stabilization of BTHF solution when compared to unstabilized BTHF. Stabilizers 6, 8 and 25 showed approximately equivalent stabilization as BTHF solution stabilized with NaBH 4 . Stabilizers 15, 22 and 31 showed increased stabilization of BTHF solution when compared to BTHF solution stabilized with NaBH 4 . Using larger sample sizes of the stabilized solutions of Example 1, final active hydride content was determined by hydrolyzing the solution and measuring the hydrogen evolved according to the method of H. C. Brown, Organic Synthesis via Boranes Vol. 1 page 214 (1975), incorporated herein by reference. BTHF assay as measured by 11 B NMR directly correlated to the active hydride content as measured by the method of H. C. Brown. Example 2 To further quantify the stabilization effect, selected samples were subjected to thermal decomposition tests. Those tests were performed on representative samples of prepared solutions using Accelerating Rate Calorimetry. The testing apparatus comprised a nitrogen flushed Hastelloy C sphere that was charged with 5 grams of the solution. The solution was heated to 350° C. in a procedure wherein heating was done in 5° C. increments with a 15 minute wait after each heating increment. After the desired reaction time was reached, the apparatus was cooled to room temperature. The thermal and pressure data was then evaluated. The results are reported in Table 5 with the stabilizer concentration in each test being 0.005 moles per liter; [BTHF] being the concentration of the THF-borane complex in moles per liter (M); the reaction onset temperature (Onset) and reaction final temperature (Final) reported in ° C.; and the heat of reaction (ΔH) reported in Joules per gram (J/g). TABLE 5 Stabilizer [BTHF] Onset Final ΔH none 1.0 66.2 184.5 358.7 none 1.5 55.8 180.3 379.0 NaBH 4 1.0 71.2 199.5 379.9 NaBH 4 2.0 50.8 216.6 470.5 Stabilizer 15 1.0 71.7 182.1 334.4 Stabilizer 15 1.5 61.5 337.6 818.3 Stabilizer 31 1.0 76.8 141.0 192.8 Stabilizer 31 1.5 66.3 313.7 734.4 This experiment indicates that stabilized BTHF solutions show higher onset temperature than do unstabilized solutions. Example 3 The effect of surface area (“SA”) and the SA to volume ratio on the thermal decomposition of a 1 mole per liter solution of BTHF in THF containing 0.005 moles per liter of a stabilizer was evaluated. A given volume of the stabilized solution was charged to a glass vessel in a high-pressure glass 1 L autoclave or high pressure NMR tube. The sample was heated for 72 hours and then cooled to room temperature. Using both gas evolution measurement and 11 B NMR, material from the cooled sample was analyzed for BTHF concentration with the results reported in moles per liter. The results are reported in Table 6 below with “Temp” indicating the reaction temperature and “Rate” indicating the BTHF molar decomposition rate in moles per hour. TABLE 6 Stabilizer SA SA/volume Temp [BTHF] Rate None 13 mm 2 25.0 mm 2 /mL 50° C. 0.39 0.85 NaBH 4 13 mm 2 25.0 mm 2 /mL 50° C. 0.45 0.76 15 13 mm 2 25.0 mm 2 /mL 50° C. 0.67 0.46 15 800 mm 2 32.2 mm 2 /mL 50° C. 0.53 0.62 15 1900 mm 2 75.4 mm 2 /mL 51° C. 0.40 0.79 The data indicate that there is a linear correlation between BTHF surface area and stability effect expressed as moles of BTHF complex decomposed per hour. In particular, when a sample having a SA of 13 mm 2 was heated at 50° C., the 1M BTHF stabilized with 0.005M stabilizer 15 showed 67% of the active product remaining in solution after 72 hours, where as the unstabilized and 0.005M NaBH 4 stabilized 1M BTHF showed only 39% and 45%, respectively. However, when the solution surface area was increased to 1900 mm 2 , 1M BTHF stabilized with 0.005M stabilizer 15 showed 40% of BTHF remaining in solution after heating for 72 hours at 50° C. Example 4 Stabilized BTHF complex solutions were subjected to testing to determine if those solutions were acceptable for shipping under the UN Recommendations on the Transportation of Dangerous Goods H.2 Test (i.e., Adiabatic Storage Test). That test quantifies the magnitude of any exothermic activity and gas generation in a chemical system under the adiabatic conditions typically encountered during the manufacture or shipping of dangerous goods. A low heat loss 1 dm 3 stainless steel Dewar flask, fitted with a flanged lid and equipped with an agitator, a temperature probe, thermo coaxial heater, reagent addition port, and having connections to a pressure sensor or gas measurement equipment, was used. The heat capacity of such a vessel is typically about 10% of that of the reaction mass, and the rate of heat loss is similar to that exhibited by a 5 m 3 vessel having natural cooling. In order to provide a heat loss environment more closely related to large vessels (about 20 m 3 ), the calorimeter was placed in an adiabatic shield in which the temperature of the vessel surroundings is controlled to ensure that there is no heat flow through the calorimeter walls. In the test, 750 mL of a prepared 1 mole per liter BTHF complex solution containing 0.005 moles per liter of the indicated stabilizer was charged to the nitrogen-purged Dewar flask which was then placed in a fan-assisted oven installed in a blast enclosure. The flask was then heated to a fixed temperature and held for a period of time to monitor exothermic activity. Temperature changes of less than about 0.1 K·hr −1 per hour correspond to a power change of greater than 0.1 W·dm −3 and can therefore be measured. Normally, detection limits of 1 K·hr −1 are employed for onset determination studies to account for the heat input due to, for example, agitation. The procedure was repeated until self-heating (i.e., an exotherm) was observed. The critical ambient temperature and SADT for a given container volume was calculated according to the UN test protocol as follows: (1) For each container size, the calculated rates of heat generation per unit mass (plotted on the ordinate, or y-axis) as a function of temperature (plotted on the abscissa, or x-axis) were plotted on a graph having linear scales. A heat generation curve for each container size having the best fit was drawn through the plotted points; (2) A straight line was drawn tangential to the each generation curve; and (3) The intersection of that straight line and the abscissa is the critical ambient temperature, i.e., the highest temperature at which the packaged material does not show self-accelerating decomposition. SADT is the critical ambient temperature rounded up to the next higher multiple of 5° C. Material having a SADT of 50° C. or higher (a critical ambient temperature of 45° C. or higher) is acceptable for shipping under UN Recommendations on the Transportation of Dangerous Goods test. The critical ambient temperature and SADT data was collected and analyzed and is reported FIGS. 3 and 4 , and in Table 7 below for various container sizes. TABLE 7 Stabilizer 100 mL 800 mL 18 L 200 L 1136 L Critical Ambient Temperature (° C.) NaBH 4 46.4 43.0 42.7 42.0 41.3 15 54.4 48.1 47.7 45.8 43.3 31 55.0 49.0 48.7 46.9 44.5 SADT (° C.) NaBH 4 50 45 45 45 45 15 55 50 50 50 45 31 55 50 50 50 45 The data show that a 1 M amine-stabilized BTHF solution has a higher SADT temperature than does a 1 M NaBH 4 -stabilized BTHF solution king it acceptable for shipping under the UN recommendations.

A stabilized borane-tetrahydrofuran complex is disclosed. Also disclosed are processes for the preparation of the borane-tetrahydrofuran complex and methods of storing and transporting the prepared complex. The borane-tetrahydrofuran complexes exhibit enhanced shelf life and increased self-accelerated decomposition temperatures.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to brushless DC motors and, more specifically, to a drive circuit for a brushless DC motor. 2. Background Description Brushless DC motors generally consist of two major stages: a pre-driver stage and an actual driver stage. The actual driver stage may be bipolar or unipolar. A bipolar driver stage consists of four switching devices, e.g., field effect transistors (FETs) or bipolar junction transistors (BJTs), arranged in a full-bridge configuration. The switching devices are driven by complementary pulses generated by the pre-driver stage such that the switching devices that are located diagonally with respect to one another are turned on at the same time. A unipolar driver stage consists of two switching devices arranged in a half-bridge configuration, only one of which is turned on at one time. The pre-driver stage consists of a discrete integrated circuit (IC) that generates the complementary pulses for the driver stage in response to the output from a Hall sensor. In a fan, the Hall sensor is switched by a magnet included in the turning impeller of the fan. Whenever the impeller of the fan or the motor has made a full revolution, the magnetic field of the impeller magnet changes relative to the position of the Hall sensor so that the output of the Hall sensor switches from one logic state (e.g., a logic low or a logic high) to the complementary logic state. Thus, there is effectively a closed loop from the output of the driver stage back to the pre-driver stage. The closed loop from the output of the driver stage to the pre-driver stage enables the fan to run essentially self-sufficiently. However, there are some conditions where the fan requires assistance to operate correctly and, very importantly, safely. For example, in a “locked rotor” condition, where the fan impeller is stopped for any reason, the fan has to turn itself off in order not to burn out the switching devices in the driver stage. After a predetermined time period of t seconds the fan must determine whether the fan impeller is free to resume rotating. The fan does this by turning on one output of the pre-driver stage and waiting for the impeller to turn. If the impeller does not begin to turn within a predetermined time period, the output of the pre-driver is turned off again. The fan repeats this cycle every t seconds. The timing for the restart cycles is provided by a resistor-capacitor network that is external of the pre-driver IC. Other features have been implemented to ensure the proper operation of the fan. For example, an alarm can be generated whenever the fan is in a locked rotor condition for greater than a predetermined amount of time. Alternatively, an alarm can be generated whenever the fan is running at speed that is below a certain RPM threshold level. Again, external circuitry is required to generate the alarm under either of these conditions. Another feature of the fan concerns the tendency of the fan to draw a high inrush current during its startup mode of operation. To counteract this tendency, an external circuit generates a pulse-width modulated (PWM) signal to enable and disable the pre-driver and driver stages in a so-called “chopping mode” of operation during the startup period. The effect of chopping the inrush current is to inhibit the rate of current flow during the startup period to provide the fan or motor with just enough current to start the fan or motor until the fan or motor is ramped up to full speed. It is known in the art to provide a discrete IC in conjunction with external circuitry for controlling brushless DC motors including fan motors. U.S. Pat. No. 5,583,404 entitled “Driver Circuit for Brushless DC Motors” and issued to Karwath et al. teaches the general concept of checking for a “locked rotor” condition, interrupting the supply of current to the motor for a limited period of time, and activating the alarm function in such circumstances and attempting a re-start after the passage of a predetermined time. Furthermore, it also teaches the use of stepped-up current during a start-up mode of a brushless motor in order to prevent power-on current surges. U.S. Pat. No. 5,838,127 entitled “Single Phase Motor for Laundering Apparatus” and issued to Young et al. discloses the general concept of utilizing a position sensor for sensing the angular position of the rotatable assembly of a motor relative to the stationary assembly of the motor and generating a control signal as a function of the sensed position to reverse the direction of rotation. U.S. Pat. No. 4,656,533 entitled “Electronically Programmable Universal Brushless DC Fan with Integral Tracking and Locked Rotor Protection” and issued to Brown discloses the concept of using a commutation sensing device such as a voltage regulator to determine fan speed and to limit the current to a fan during a start-up condition or in a locked rotor condition. U.S. Pat. No. 5,258,696 entitled “IC Controller for Brushless DC Motors” and issued to Le discloses the concept of using a single IC chip driver for brushless DC fan motors, where the input to the IC driver consists of a signal which represents the rotor's position with respect to the stator's windings and which is used by the IC driver to generate commutation commands and commutate power to the motor's stator windings to drive the motor. Similarly, U.S. Pat. No. 5,350,988 entitled “Digital Motor Controller” and also issued to Le discloses the same concept, wherein the analog position signal of the rotor with respect to the stator is converted to digital data to be processed by the digital controller. U.S. Pat. No. 5,013,985 entitled “Microcomputer with Motor Controller Circuit” and issued to Itoh et al. (“the '985 Patent”) suggests use of a microcomputer with CPU, read only memory (ROM) and random access memory RAM in a single chip with a motor controller circuit. However, the '985 Patent does not suggest use of a microcomputer as the driver circuit for the motor. Instead, the microcomputer provides signals to the motor controller circuit for generating three-phase inverter waveforms. Neither does it suggest any of the previously mentioned features that are used to ensure the proper operation of a brushless DC fan. U.S. Pat. No. 5,317,244 entitled “Motor Control Unit Provided with Anti-Burning Device” and issued to Ishikura describes a motor controller with the capability to prevent the burning out of the circuits by limiting the time in which current is supplied to the motor if the rotational speed of the motor falls below a predetermined level or if a “locked rotor” condition occurs. Similarly, U.S. Pat. No. 5,327,052 entitled “Method and Apparatus for Controlling Brushless DC Motor” and issued to Sakurai et al. describes a method for providing stepped-up current during the start-up mode of a brushless DC motor by reading and evaluating the rotor position and increasing the drive current to the DC motor at a predetermined rate until the rotor is rotated. Likewise, “chopping mode” operation of a brushless and sensorless DC motor is described in U.S. Pat. No. 5,350,984 entitled “Method and Apparatus for Starting a Brushless DC Motor” and issued to Carobolante et al. There are significant disadvantages associated with implementing these features using a discrete IC in conjunction with external circuitry. In using a discrete IC, the designer is constrained by the parameters of the particular discrete IC and, to the extent that the discrete IC provides the capability to change the restart timing interval for the locked rotor condition, there exists a limited range of flexibility in changing this restart timing interval. A customer may desire the fan to generate data relating to temperature conditions, speed, and current consumption. The signals generated by the fan may need to change to communicate with the customer's interface, but a discrete IC used with external circuitry cannot accommodate changes in the data signals generated by the fan. The customer may also want to be able to upgrade his fan to include subsequently developed features and improvements. With a discrete IC driver, the customer is limited to the features provided with the purchased configuration of the fan, and the customer must purchase a new fan to obtain the benefit of any subsequently developed features or improvements. Another significant drawback associated with implementing these features using a discrete IC in conjunction with external circuitry is the complication and inefficiency involved in manufacturing fans and motors according to a variety of different customer requirements. A manufacturer of fans and motors may need to be able to support a multitude of different driver configurations. For example, not all discrete IC drivers offer similar features, and external circuitry is needed to provide the features that are not provided by the discrete IC. Furthermore, each customer may not need all of the features provided by a particular discrete IC, and even if each customer does need all of the features provided by a particular discrete IC, the parameters of those features may vary from customer to customer. As a result, a multiplicity of physical configurations for the driver stage are inevitable when a discrete IC is used. Accordingly, there is a need in the art to replace the multitude of different discrete driver configurations for a brushless DC motor with a single driver configuration that is adaptable to provide a customer with a customized combination of features for a brushless DC motor. SUMMARY The present invention is directed to a system and method that satisfies the need for a single driver configuration that is adaptable to provide a customer with a customized combination of features for a brushless DC motor. According to an embodiment of the present invention, a drive circuit for a brushless DC motor that controls at least one operation feature of said motor, the at least one feature utilizing at least one parameter that defines the desired operation of the feature, comprises: a driver stage for providing a current to a stator coil; and means coupled to said driver stage for varying said at least one parameter. The means for varying may vary the parameter or parameters without changing the physical configuration of the brushless DC motor. The means for varying may include input means for inputting said at least one parameter. The means for varying said parameters may comprise a microcontroller that executes software program instructions to control the operation features. One operation feature may comprise limiting the inrush current drawn by said brushless DC motor upon start-up of said motor, and the parameters may comprise a threshold reference value for said inrush current, or a compare value from which a voltage representing said inrush current is subtracted. Another operation feature may comprise speed control of said brushless DC motor using an analog voltage, and the parameter may comprise a threshold reference value for the speed of said motor. Yet another operation feature may comprise generating an alarm signal, and the parameters may comprise a threshold level for the speed of said DC motor, a value stored in a counter, or a value indicating a time for generating said alarm. A further operation feature may comprise determining a locked rotor condition, and the parameter may comprise a value stored in a counter. An even further operation feature may comprise generating an alarm in response to the detection of a locked rotor condition, and the parameter may comprise a value stored in a counter. Another operation feature may comprise restarting said motor following the detection of a locked rotor condition, and the parameter may comprise a value stored in a counter. According to another embodiment of the present invention, a drive circuit for a brushless DC motor that controls at least one of a number of possible operation features of said motor comprises: a driver stage for providing a current for a stator coil; and means for varying which of said number of possible operation features of said motor are controlled. The possible operation features of said motor may comprise: speed control of said motor using a pulse-width modulated signal; speed control of said motor using an analog voltage; limiting inrush current drawn by said motor upon start-up of said motor; generating an alarm signal if the speed of said motor is below a threshold level; detecting a locked rotor condition; generating an alarm in response to the detection of a locked rotor condition; and restarting said motor following the detection of a locked rotor condition. The above, and other features, aspects, and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 shows a simplified block diagram of a brushless DC motor according to an embodiment of the present invention; FIG. 2 shows a schematic diagram of the brushless DC motor shown in FIG. 1; FIG. 3 shows a flowchart describing the commutation of the brushless DC motor shown in FIGS. 1 and 2; FIG. 4 shows a flowchart describing the operation of the inrush current limiting and analog speed control in the brushless DC motor shown in FIGS. 1 and 2; FIG. 5 shows a flowchart describing the operation of pulse-width modulated speed control in the brushless DC motor shown in FIGS. 1 and 2; FIG. 6 shows a flowchart describing the operation of a low speed alarm in the brushless DC motor shown in FIGS. 1 and 2; FIG. 7 shows a flowchart describing the operation of the brushless DC motor shown in FIGS. 1 and 2 in response to a locked rotor condition; and FIG. 8 shows another flowchart describing the operation of the brushless DC motor shown in FIGS. 1 and 2 in response to a locked rotor condition. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show a simplified block diagram and a schematic diagram respectively of a brushless DC motor, generally designated 100 , according to an embodiment of the present invention. The motor 100 includes a Hall sensor 10 having an output 12 ; a microcontroller 20 having complementary outputs 30 and 40 ; stator coil 50 ; and switches SW 1 and SW 2 . In the block diagram shown in FIG. 1, the switches SW 1 and SW 2 comprise the two switches that are on at the same time in a full-bridge driver stage. In the schematic diagram shown in FIG. 2, the switches SW 1 and SW 2 of FIG. 1 are represented by switches 60 and 70 or switches 80 and 90 . In a preferred embodiment according to the present invention, the Hall sensor 10 comprises an industry part number UA3175 device and the microcontroller 20 comprises an industry part number 12C671 device. One application for the brushless DC motor shown in FIGS. 1 and 2 is in a fan of the type used for cooling electronic circuits. Such a brushless DC fan, which is to say a fan driven by a brushless DC motor, further includes an impeller mounted in an impeller housing (not shown). The impeller of the fan is caused to rotate when current flows through the switch SW 1 , the stator coil 50 , and the switch SW 2 . The direction of impeller rotation, i.e., clockwise or counter-clockwise, is determined by the direction of current flow through the switch SW 1 , the stator coil 50 , and the switch SW 2 . The impeller housing contains a permanent magnet which produces a magnetic field for the brushless DC fan. The Hall sensor 10 detects a change in the state of the magnetic field that is produced as the impeller of the brushless DC fan rotates in relation to the permanent magnet. As the impeller reaches a rotational extreme in either the clockwise or the counter-clockwise direction, the Hall sensor 10 detects the change in the state of the magnetic field of the brushless DC fan, and the output 12 of the Hall sensor changes its logic state. The output 12 of the Hall sensor 10 is provided to the microcontroller 20 , and the state of the outputs 30 and 40 of the microcontroller 20 is a function of the output 12 of the Hall sensor 10 . Thus, according to an embodiment of the present invention, whenever the microcontroller 20 senses a change in the output 12 of the Hall sensor 10 , the microcontroller 20 changes its outputs 30 and 40 in a complementary manner. For example, if the output 12 of the Hall sensor 10 is a logic high, the microcontroller 20 causes the output 30 to transition from a logic low to a logic high and simultaneously causes the output 40 to transition from a logic high to a logic low. It will be appreciated by those having skill in the art that the particular relationship between the state of the outputs 30 and 40 of the microcontroller 20 and the output 12 of the Hall sensor 10 can be varied to conform to the requirements of a particular brushless DC motor or fan. According to an embodiment of the present invention, the microcontroller 20 changes the state of its outputs 30 and 40 in accordance with software program instructions that it executes according to techniques that are well-known in the art and which will not be described further herein. In an embodiment of the present invention, the microcontroller 20 effects commutation of the brushless DC motor by executing software program instructions in accordance with the flowchart shown in FIG. 3. A “locked rotor” condition is able to be detected simultaneously with the steps of FIG. 3 . FIG. 3 shows a flowchart describing the commutation of the brushless DC motor shown in FIGS. 1 and 2. Referring to FIGS. 1 and 3, in accordance with Steps 201 - 212 the output signal 12 of the Hall sensor 10 of FIG. 1 is used by the microcontroller 20 to provide the outputs 30 and 40 that drive the switches SW 1 and SW 2 of the brushless DC motor. In Step 201 , the microcontroller 20 checks the state of the output 12 of the Hall sensor 10 . In Step 202 , the microcontroller 20 determines whether the output 12 of the Hall sensor 10 is in a logic high state. If so, the microcontroller 20 causes the logic state of output 30 to go high in Step 203 . In Steps 204 and 205 the microcontroller 204 continues to check the logic state of the output 12 of the Hall sensor 10 . While the microcontroller 20 executes Steps 204 and 205 , a delay counter corresponding to the output 30 is decremented. Once the output 12 of the Hall sensor 10 changes its logic state from high to low, the microcontroller 20 clears its output 30 in Step 206 and reloads the delay counter for output 30 . The magnitude of the value stored in the delay counter, and hence the duration of the delay in Step 207 , is a parameter that can be varied simply by editing the software program instructions that are executed by the microcontroller 20 . If, for any reason, the logic state of the output 12 of the Hall sensor 10 does not change from a high to a low before the delay counter is decremented to zero, the delay counter will “roll over” and the microcontroller 20 will execute software program instructions for a “locked rotor” condition, as described further herein. As is well-known to these having skill in the art, a counter “rolls over” when the contents of the counter are decremented from 00h to FFh. Once the output 12 of the Hall sensor 10 changes its logic state from a high to a low, the microcontroller 20 causes the logic state of output 40 to go high in Step 208 . In Steps 209 and 210 the microcontroller 20 continues to check the logic state of the output 12 of the Hall sensor 10 . While the microcontroller 20 executes Steps 209 and 210 a delay counter corresponding to the output 40 is decremented. Once the output 12 of the Hall sensor 10 changes its logic state from low to high, the microcontroller 20 clears its output 40 in Step 211 and reloads the delay counter for output 40 . The magnitude of the value stored in the delay counter, and hence the duration of the delay in Step 212 , is a parameter that can be varied simply by editing the software program instructions that are executed by the microcontroller 20 . If, for any reason, the logic state of the output 12 of the Hall sensor 10 does not change from a low to a high before the delay counter is decremented to zero, the delay counter will roll over and the microcontroller 20 will execute software program instructions for a “locked rotor” condition, as described further herein. According to another embodiment of the present invention, an analog source such as a variable resistor, a current sense resistor, a thermistor, or any other voltage source can be coupled to an analog-to-digital (A/D) input 14 of the microcontroller 20 to effect inrush current limiting or analog speed control. Whenever an analog voltage greater than zero Volts is captured on the A/D input 14 of the microcontroller 20 , the software program instructions that are being executed by the microcontroller 20 call a program subroutine in which the outputs 30 and 40 are turned off. A delay value is generated according to the magnitude of the captured analog voltage and is loaded into a delay register. After the delay register has rolled over, the microcontroller 20 turns on outputs 30 and 40 and the software program instructions return control of the microcontroller 20 to the main commutation program. This effects analog speed control. To provide inrush current limiting for the brushless DC motor, a current sense resistor R 1 can be coupled to the A/D input 14 at general purpose input/output (GPIO) port 5 (pin 2 ) of the microcontroller 20 . When a predetermined threshold for the inrush current is exceeded, the microcontroller 20 executes the same program subroutine described above in connection with analog speed control. A binary value corresponding to the magnitude of the inrush current is loaded into the delay register to delay turning on outputs 30 and 40 , thereby providing the current limiting function. FIG. 4 shows a flowchart describing the operation of the inrush current limiting and analog speed control in the brushless DC motor shown in FIGS. 1 and 2. In accordance with software program instructions that are described by the flowchart shown in FIG. 4, the microcontroller 20 loads a value into a threshold reference register and another value into a “compare” register in Step 301 . In Step 302 the microcontroller 20 performs an A/D conversion of the analog voltage provided by the analog source at the A/D input 14 of the microcontroller 20 . In Step 303 the microcontroller 20 determines whether the analog voltage captured at it's a/D input 14 exceeds the predetermined threshold value in the threshold reference register. If not, the microcontroller 20 continues to perform an A/D conversion of the captured analog voltage at it's a/D input. If the captured voltage exceeds the threshold value, in Step 304 the microcontroller 20 turns off the outputs 30 and 40 . In Step 305 , the microcontroller 20 subtracts the captured value at it's a/D input from the value stored in the compare register. The difference is complemented and the result is loaded into a delay register. In Steps 306 and 307 , the delay register is decremented and the outputs 30 and 40 are turned on in Step 308 when the delay register is decremented to zero. Once the outputs 30 and 40 are turned on in Step 308 , the microcontroller resumes the A/D conversion of the analog voltage captured at it's a/D input in Step 302 . The source code for an exemplary subroutine for effecting inrush current limiting is shown in Table 1. The magnitude of the threshold reference value for the inrush current in Step 301 is a parameter that can be varied simply by editing the software program instructions that are executed by the microcontroller 20 . For example, the threshold reference value for the inrush current is set in the first line of the source code of Table 1. If the threshold reference register is loaded with the hexadecimal value 1Fh, the maximum allowable current flow through the current sense resistor is 1 Ampere. If the threshold register is loaded with the hexadecimal value 0Fh, the maximum allowable current flow through the current sense resistor is 0.5 Ampere. No other lines of the source code need to be changed to implement changes in the current limiting function. According to an embodiment of the present invention, the software program instructions for the microcontroller 20 are such that, if the analog voltage captured at the A/D input of the microcontroller 20 is large, the outputs 30 and 40 of the microcontroller 20 will be turned off longer. Conversely, if the analog voltage captured at the A/D input of the microcontroller 20 is small, the outputs 30 and 40 of the microcontroller 20 will be turned off for a shorter period of time. Thus, the delay values stored in the delay register constitute a duty ratio transmitted to the outputs 30 and 40 of the microcontroller 20 , and the outputs 30 and 40 of the microcontroller 20 are pulse-width modulated in accordance with the magnitude of the current flowing through the current sense resistor. TABLE 1 movlw 0 × 1F ; load the working register... movwf ref ;...and copy to the ref register. AD bcf output1 ;turn output 30 off. bcf output2 ;turn output 40 off. decfsz dlycnt2 goto comp decfsz dlycnt8 goto comp goto locked comp movf ADRES, w ;copy literal to w. subwf compare, w ;subtract literal from compare register. movwf compare ;put back into the “compare” register again. comf compare ;complement the literal in the ;“compare” register... movf compare, w ;...and move back to w... movwf delay ;...and from there to the delay register. rep2 movlw 0 × 04 movwf dlycnt7 rep NOP decfsz dlycnt7 goto rep decfsz delay ;decrement the delay value goto rep2 btfss hall ;read Hall sensor status goto no2 ;Hall output low movlw 0 × FF ;copy literal to w. movwf compare ;need an A/D reference value. bsf output1 ;turn output 30 on. return no2 movlw 0 × FF ;copy literal to w. movwf compare ;need an A/D reference value. bsf output2 ;turn output 40 on. return ;to main routine. According to a further embodiment of the present invention, the microcontroller 20 executes software program instructions to effect speed control of the brushless DC motor using a pulse-width modulated (PWM) signal. The frequency and the duty ratio of the PWM signal determine the speed of the brushless DC motor and thus the fan. FIG. 5 shows a flowchart describing the operation of pulse-width modulated speed control in the brushless DC motor shown in FIGS. 1 and 2. Referring to FIG. 5, during normal commutation and during locked rotor operation, the microcontroller 20 reads the logic state at a predetermined one of its general purpose input/output (GPIO) ports in Step 401 to determine whether its logic state is a low. In the embodiment shown in FIG. 2, the microcontroller 20 comprises industry part No. 12C71 microcontroller with the GPIO port 3 (GPIO 3 ) (pin 4 ) used for PWM speed control. Referring again to FIG. 5, whenever a low occurs at GPIO 3 , the software program instructions direct the microcontroller 20 in Step 402 to turn both outputs 30 and 40 off. The microcontroller 20 continues to check the logic level of GPIO 3 and keeps the outputs 30 and 40 off as long as that logic state remains a low. When the logic level of GPIO 3 goes high, in Step 404 the microcontroller 20 determines the logic state of the output 12 of the Hall sensor 10 to determine which of the outputs 30 and 40 should be turned on. If the logic state of the output 12 of the Hall sensor 10 is high, the microcontroller 20 turns a first output, e.g. output 30 , on to resume commutation of the brushless DC fan. Conversely, if the logic state of the output 12 of the Hall sensor 10 is low, the microcontroller 20 turns a second output, e.g. output 40 , on to resume commutation of the brushless DC fan. In this way, the use of a PWM signal is ideally suited for the dedicated speed control input at GPIO 3 . The source code for an exemplary subroutine for effecting PWM speed control is shown in Table 2. TABLE 2 speed1 bcf output1 ;turn off FET1. repeat1 btfss speedcntr ;speed control input still low? goto repeat1 ;repeat the process. btfss hall ;Hall sensor high? goto on2 ;go to turn FET1 on. bsf output1 ;turn FET0 on. goto loop1 ;keep checking Hall sensor in ;normal routine subroutine. speed2 bcf output2 ;turn off FET2. repeat2 btfss speedcntr ;speed control input still low? goto repeat2 ;repeat the process. btfsc hall ;Hall sensor low? goto on1 ;go to turn output 0 off, and FET 0 ;on. bsf output2 ;turn FET1 on. goto loop3 ;keep checking Hall sensor in ;normal routine subroutine. According to an even further embodiment of the present invention, during normal commutation of the brushless DC fan, the software program instructions executed by the microcontroller 20 cause the microcontroller 20 to periodically call an alarm subroutine program after a predetermined amount of time has elapsed. This predetermined amount of time is a parameter that can be varied simply by editing the software program instructions that are executed by the microcontroller 20 . In a preferred embodiment, a change in the logic state of the output 12 of the Hall sensor 10 from a high level to a low level generates an interrupt every 4 milliseconds when the brushless DC fan is rotating at normal speed, which causes the software program instructions for the microcontroller 20 to call the alarm subroutine program. The alarm subroutine program decrements a previously loaded counter. If the counter rolls over, an instruction to reset the alarm is performed by the microcontroller 20 . Simultaneously with the generation of the interrupt, the software program instructions cause the microcontroller 20 to load an independent timer with a hexadecimal value. FIG. 6 shows a flowchart describing the operation of a low speed alarm in the brushless DC motor shown in FIGS. 1 and 2. Referring to FIG. 6, in Step 501 the interrupt is generated, and in Step 502 the microcontroller 20 loads a timer labelled as “timer 0 ” with a hexadecimal value. The magnitude of the value stored in timer 0 , and hence the duration of the timer in Step 502 , is a parameter that can be varied simply by editing the software program instructions that are executed by the microcontroller 20 . The source code for an exemplary subroutine for loading the timer with a hexadecimal value is shown in Table 3. TABLE 3 Timrset bcf INTCON, INTF ;clear the GPIO2 interrupt flag ;bit (this interrupt is generated ;by the Hall sensor). movwf w_temp ;save the w register contents. swapf STATUS, w ;copy status register to w. bcf STATUS, RP0 ;make sure the desired bank is ;selected movwf status_temp ;save the status register ;contents. movlw 0 × B1 ;load w register (this literal ;determines the lowspeed alarm ;trippoint). movwf TMR0 ;copy w to timer0 for a trip ;point of 1200 RPM. swapf status_temp, w ;swap status_temp register into ;w (to set bank back to original ;state). movwf STATUS ;restore the status contents to ;the state where it was before ;leaving for the subroutine). swapf w_temp, f ;swap and load the “w” register ;without... swapf w_temp, w ;...affecting the status register. retfie If the speed of the Brushless DC fan is normal, timer 0 does not roll over, but is instead reset by the generation of the next interrupt by the transition of the output 12 of the Hall sensor 10 . If the output 12 of the Hall sensor 10 is inhibited, for example due to a low speed or a locked rotor condition, an interrupt to reset the timer is not generated by the falling transition of the output 12 of the Hall sensor 10 and the timer is not reset. As a result, the timer rolls over and generates its own interrupt which causes the microcontroller 20 to execute instructions for a low speed alarm subroutine. Referring again to FIG. 6, in Steps 503 and 504 the microcontroller 20 decrements a delay counter labelled counter 4 and determines whether the value in counter 4 has reached zero. If not, the program returns to the main commutation routine. Once the value in counter 4 has reached zero, the logic state of the alarm output of the microcontroller 20 goes low in Step 505 to indicate an alarm condition. It will be appreciated by those having skill in the art that the software program instructions can be such that the alarm output of the microcontroller 20 goes high in Step 505 to indicate an alarm condition. Thus, the low speed alarm is not set immediately and counter 4 provides a predetermined delay before the alarm is activated. The magnitude of the value stored in the counter 4 , and hence the duration of the delay in Steps 503 and 504 , is a parameter that can be varied simply by editing the software program instructions that are executed by the microcontroller 20 . The source code for an exemplary low speed alarm subroutine is shown in Table 4. TABLE 4 alarm bcf INTCON, T0IF ;clear timer interrupt flag bit. movwf w_temp ;save the w register contents. swapf STATUS, w ;copy status register to w. bcf STATUS, RP0 ;make sure the desired bank is ;selected. movwf status_temp ;save the status register contents. decfsz dlycnt4 ;decrement delay counter4. goto saved bcf alarmout ;change this line to switch from alarm ;high pass, low fail and vice versa goto load saved swapf status_temp, w ;swap status_temp register into w (to ;back to original state). movwf STATUS ;restore the status contents to the ;state where it was before leaving for ;the subroutine. swapf w_temp, f ;swap and load the “w” register ;without affecting the status register swapf w_temp, w retfie ;return to commutation routine. load movlw 0 × 03 ;load w movwf dlycnt6 ;load delay counter 6 to prevent ;alarm reset. swapf status_temp, w ;swap status_temp register into w (to ;set bank back to original state). movwf STATUS ;restore the status contents to the ;state where it was before leaving for ;the subroutine. swapf w_temp, f ;swap and load the “w” register ;without affecting the status register. swapf w_temp, w retfie In this low speed alarm subroutine, the microcontroller 20 re-loads a counter (labelled dlycnt 6 in the source code of Table 4) used in the alarm subroutine represented by Steps 503 through 505 of FIG. 6 such that during a low speed or locked rotor condition the counter cannot time out to reset the alarm. Thus, the brushless DC fan will have a latched alarm because the alarm cannot be reset once it has been set. It will be appreciated by those having skill in the art that the alarm need not be latched but can be removed once the low speed or locked rotor condition is removed. In normal operation of the brushless DC fan, one of the outputs 30 and 40 of the microcontroller 20 is turned on while the other one of the outputs is turned off until the impeller of the fan has completed a revolution. Once the impeller has completed a revolution the microcontroller 20 complements the outputs 30 and 40 . However, before complementing the outputs 30 and 40 , the microcontroller 20 must be certain that the impeller actually completed the commutation cycle. According to yet another embodiment of the present invention, the software program instructions cause the microcontroller 20 to turn off its outputs 30 and 40 and to delay the turn on of the alarm output for a predetermined amount of time. The software program instructions further cause the microcontroller 20 to continuously check whether the locked rotor condition has been removed. FIG. 7 shows a flowchart describing the operation of the brushless DC motor shown in FIGS. 1 and 2 in response to a locked rotor condition. Referring to FIG. 7, in Step 601 the microcontroller 20 checks the logic state of the output 12 of the Hall sensor 10 to determine which of the outputs 30 and 40 should be turned on. After turning on the appropriate output, the microcontroller 20 decrements a first delay counter labelled “counter 1 ” in Step 602 . In Step 603 , the microcontroller determines whether counter 1 has rolled over. If not, microcontroller 20 again checks the logic state of the output 12 of the Hall sensor 10 in Step 604 . If the logic state of the output 12 has not changed, the microcontroller 20 repeats Steps 602 through 604 . If the logic state of the output 12 has changed, the microcontroller 20 repeats Steps 601 through 604 . Once counter 1 has rolled over, in Step 605 the microcontroller 20 decrements a second delay counter labelled counter 2 . In Step 606 , the microcontroller determines whether counter 2 has rolled over. If not, microcontroller 20 again checks the logic state of the output 12 of the Hall sensor 10 in Step 604 . If the logic state of the output 12 has not changed, the microcontroller 20 repeats Steps 602 , 603 , 605 , and 606 . If the logic state of the output 12 has changed, the microcontroller 20 repeats Steps 601 through 606 . In a preferred embodiment of the present invention, the magnitude of the hexadecimal values stored in the delay counters counter 1 and counter 2 are chosen such that, once both delay counters counter 1 and counter 2 have rolled over, a time period of approximately 250 milliseconds will have elapsed. If the impeller has not made a revolution in that time period, the locked rotor subroutine program is initiated in Step 607 once counter 2 has rolled over. This time period is allotted for the impeller of the brushless DC fan to make one revolution. The magnitude of the values stored in counter 1 and counter 2 , and hence the duration of the delays in Steps 602 and 603 and Steps 605 and 606 respectively, are parameters that can be varied simply by editing the software program instructions that are executed by the microcontroller 20 . It will be appreciated by those having skill in the art that the hexadecimal values stored in the delay counters counter 1 and counter 2 are chosen keeping in mind the time period needed by the microcontroller 20 to execute an instruction. For example, the industry part number 12C671 microcontroller used in the embodiments described herein executes an instruction in 1 microsecond. The time period needed by the microcontroller 20 to execute an instruction is used as the time base to create the delays required in Steps 602 and 603 and Steps 605 and 606 , and throughout the software program instructions executed by the microcontroller 20 . The first part of the locked rotor subroutine program turns off the outputs. 30 and 40 of the microcontroller 20 and delays the turning on of the alarm output for a predetermined number of seconds. FIG. 8 shows another flowchart describing the operation of the brushless DC motor shown in FIGS. 1 and 2 in response to a locked rotor condition. Referring to FIG. 8, in Step 701 the microcontroller 20 turns off both its outputs 30 and 40 . In Steps 702 and 703 the microcontroller 20 decrements counter 1 until the value in counter 1 is zero. Then, in Steps 704 and 705 the microcontroller 20 decrements counter 2 until the value in counter 2 is zero. In a second part of the routine, a third delay counter labelled “counter 3 ” is decremented to zero to provide a delay before the microcontroller 20 checks whether the locked rotor condition is removed and the impeller of the brushless DC fan is free. The magnitude of the values stored in counter 1 , counter 2 , and counter 3 , and hence the duration of the delays in Steps 702 through 707 , are parameters that can be varied simply by editing the software program instructions that are executed by the microcontroller 20 . The source code for an exemplary locked rotor routine is shown in Table 5. TABLE 5 locked bcf output1 ;turn off output1. bcf output2 ;turn off output2. movlw .030 ;load w (change this value for desired delay ;time). movwf dlycnt1 ;load delay counter1. dloop3 movlw .100 ;load w. movwf dlycnt3 ;load delay counter3. dloop2 movlw 0 × F9 ;load w. movwf dlycnt2 ;load delay counter2. dloop1 nop ;don't do anything. decfsz dlycnt2 ;decrement delay counter2. goto dloop1 ;repeat. decfsz dlycnt3 ;decrement delay counter3. goto dloop2 ;repeat loading delay counter2. decfsz dlycnt1 ;decrement delay counter1. goto dloop3 ;repeat loading delay counter3. bcf alarmout ;Change this line to switch from alarm high movlw .050 ;pass, ;load w (change this value to desired restart movwf dlycnt1 ;time). ;load counter1. dloop movlw .100 ;10 seconds delay. D movwf dlycnt2 ;load second counter. dloop movlw 0 × f9 ;load w. C movmf dlycnt2 ;load counter 2. dloopE ;don't do anything. nop dlycnt2 ;decrement secondary counter. decfsz dloopE ;continue secondary loop. goto dlycnt3 ;decrement primary counter. decfsz dloopC ;reload counter one. goto dlycnt1 ;decrement counter1. decfsz dloopD ;reload counter 3. goto start1 The embodiments of the present invention that have been described herein have the advantage that design and manufacture of the brushless DC fan is greatly simplified. In order to comply with the variety of customer specifications when using a discrete IC to drive the driver stage switches 50 and 70 , the configuration of the components on the printed circuit board (PCB) must be changed or the layout of the PCB must be changed. In either case extensive manual labor, documentation control, and interfacing with vendors is involved. The use of the microcontroller 20 to drive the driver stage switches 50 and 70 greatly simplifies the process of designing and manufacturing a brushless DC fan to customers' specifications. In accordance with the embodiments of the present invention, the software program instructions executed by the microcontroller 20 provide all the features that customers could require, including commutation, inrush current limit control, PWM speed control, analog speed control, a locked rotor restart, a locked rotor alarm, and a low speed alarm. Additional features can be added to the brushless DC fan simply by adding additional subroutines to the software program instructions. Furthermore, the parameters of the features of the brushless DC fan can easily be changed to comply with customers' specifications by editing the software program instructions that are downloaded into and executed by the microcontroller 20 . As a result, the embodiments according to the present invention advantageously enable the use of a single PCB configuration for each brushless DC fan, regardless of its particular features. The reliability of the Brushless DC fan increases dramatically because of the reduced number of components as compared to the use of discrete ICs with external circuitry. Additionally, hardware configuration changes, their corresponding documentation changes, and vendor interfacing become obsolete. Instead, once a particular customer's fan specifications have been received, a technician can edit the source code of the software program instructions for the microcontroller 20 and the software program instructions can be downloaded into the microcontroller 20 using a programming device located near the production line immediately prior to shipping the brushless DC fan to the customer. In accordance with the embodiments of the present invention, brushless DC fans can be simply and easily configured to comply with a customer's requirements and, consequently, product turnaround time increases dramatically. Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. For example, although the embodiments of the present invention have been described in the context of Brushless DC fans, those having skill in the art will understand the applicability of the present invention to any apparatus that utilizes a brushless DC motor.

A drive circuit for a brushless DC motor controls at least one of a number of possible operation features of the motor. The drive circuit includes a driver stage for providing a current for a stator coil and varies which of the number of possible operation features of the motor are controlled. The operation features of the motor include inrush current limit control, PWM speed control, analog speed control, detecting a locked rotor condition, setting an alarm following detection of the locked rotor condition, restarting the motor following the locked rotor condition, detecting a low speed condition, and setting an alarm following detection of the low speed condition. Some of the operation features of the motor utilize at least one parameter that defines the desired operation of the feature. The drive circuit further varies the parameters of the operation features without changing the physical configuration of the brushless DC motor.

RELATED APPLICATIONS [0001] This application contains subject matter related to co-owned U.S. patent application for “Systems and Methods of Brokering Creative Content Onlille” of Douglas W. Cole (Docket No. 200500150-1) filed on the same day herewith and incorporated herein for all that is disclosed. TECHNICAL FIELD [0002] The described subject matter relates to creative content, and more particularly to systems and methods of partnering content creators with content partners online. BACKGROUND [0003] In order for many artists to be successful, at least financially, they need backing from the art industry, such as, e.g., recording companies, network/cable television, movie producers, art dealers, or publishing houses. However, submitting creative works (e.g., paintings, photographs, movie or television scripts, literary compilations, music, and other artwork) to those working in the art industry is often difficult and discouraging for the typical artist. Much of the art industry will only deal with agents, and the best agents have exclusive client lists. Therefore, unless the artist has “connections” (e.g., family members or close personal friends) in the art industry or happens to be “discovered” by someone in the art industry, the artist's work may go unnoticed. [0004] Artists may gain exposure in the art industry by participating in contests or talent shows. Although the top contestants may receive a contract or be introduced to top agents, ultimately the goal of such contests is for the contest sponsor to “discover” new talent. The other contestants may receive a consolation prize and their ranking relative to the other contestants (e.g., fifth place), but are otherwise turned away. The artists typically do not receive any substantive feedback for improving their creative works. [0005] The Internet has also provided a medium for some artists to present and/or sell their creative works. Internet sites include online galleries for posting pictures, online music stores for posting music, and even online publishers. However, these Internet sites only provide the artist with a forum for presenting and/or selling their creative works over the Internet. The owners of these Internet sites typically do not work with agents or others in the art industry. Nor do the artists receive any substantive feedback for improving their creative works. BRIEF DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 is a high-level illustration of an exemplary networked computer system which may be implemented for brokering creative content online. [0007] FIG. 2 is a schematic illustration of exemplary functional modules of a broker service. [0008] FIG. 3 is a block diagram illustrating exemplary user registration and corresponding user profile for a broker service. [0009] FIG. 4 is a high-level diagram illustrating exemplary queues for use with a broker service. [0010] FIG. 5 is a flowchart illustrating exemplary operations which may be implemented by a broker service to have creative content reviewed. [0011] FIG. 6 is a flowchart illustrating exemplary operations which may be implemented by a broker service for matching an agent with creative content. [0012] FIG. 7 is a flowchart illustrating exemplary operations which may be implemented by a broker service for selling creative content. [0013] FIG. 8 is a schematic illustration of an exemplary computing device that may be utilized for brokering creative content online. DETAILED DESCRIPTION [0014] Briefly, systems and methods described herein may be implemented as an “online agent” to broker any of a wide variety of creative works to consumers, commercial content distributors, content developers, agents, and others in the relevant industry in a secure, timely, and cost-effective manner. Exemplary systems and methods may be implemented on at least two levels to provide feedback to content creators based on peer review and/or industry review of their creative content. Content creators may also be matched with one or more content partners (e.g., agents, studios, and buyers). [0015] In an exemplary embodiment, a content creator (i.e., either the artist or a person acting on behalf of the artist) uploads creative content in electronic format to a host for brokering the creative content online (generally referred to herein as the “brokering service”). The content creator may agree to review at least a portion of creative content (e.g., abstracts, summaries, or the entire work) posted by other users in exchange for peer review of his or her own creative content. Alternatively, the content creator may request (e.g., for a fee) to have his or her creative content reviewed by a contract reviewer, such as an industry expert or other qualified reviewer. In any event, the content creator receives feedback based on the review. [0016] In another exemplary embodiment, creative content may be reviewed using a multi-tiered approach, wherein creative content that satisfies an initial approval threshold (e.g., 60% peer approval rating) may then be reviewed at a higher tier (e.g., by professional reviewers). [0017] In other exemplary embodiments, the broker service may facilitate a sale of the creative content, or even a partnership between the content creator and an agent or studio. At least a portion of creative content (e.g., abstracts, summaries, or the entire work) may be provided to agents and buyers on a first-come, first-served basis to pique their interest and instill a sense of urgency for purchasing the creative content or representing the content creator as his or her agent. [0018] In still other exemplary embodiments, a fee structure may be implemented wherein a fee is charged for receiving and storing the user's creative content, for reviewing creative content, and/or for partnering the content creator with an agent or buyer. Fees may also be charged to content partners, e.g., for providing access to “fresh” creative content. [0019] It is noted that operations described herein may be embodied as logic instructions on a computer-readable medium. When executed on a processor, the logic instructions cause a general purpose computing device to be programmed as a special-purpose machine that implements the described operations. [0000] Exemplary Systems [0020] FIG. 1 is a high-level illustration of an exemplary networked computer system 100 (e.g., the Internet) which may be implemented for brokering creative content online. The networked computer system 100 may include one or more communication networks 110 , such as a local area network (LAN) and/or wide area network (WAN). A host 120 may be implemented in the networked computer system 100 to broker any of a wide variety of creative content online. [0021] Host 120 may include one or more computing systems, such as a server 122 with computer-readable storage 124 . Host 120 may execute a broker application 130 implemented in software, as described in more detail below with reference to FIG. 2 . Host 120 may also provide services to other computing or data processing systems or devices. For example, host 120 may also provide transaction processing services, email services, etc. [0022] Host 120 may be provided on the network 110 via a communication connection, such as a dial-up, cable, or DSL connection via an Internet service provider (ISP). Host 120 may be accessed directly via the network 110 , or via a network site 140 . In an exemplary embodiment, network site 140 may also include a web portal on a third-party venue (e.g., a commercial Internet site), which facilitates a connection for one or more clients with host 120 (e.g., via back-end link 145 ). In another exemplary embodiment, portal icons may be provided (e.g., on third-party venues, pre-installed on computer or appliance desktops, etc.) to facilitate a direct link to the host 120 . [0023] The term “client” as used herein refers to a computing device through which one or more users (e.g., content creators and content partners) may access the broker service. For purposes of illustration, users may include one or more content creators in a content creator pool 150 (e.g., accessing network 110 via computing devices 155 a - c ), one or more reviewers in a reviewer pool 160 (e.g., accessing network 110 via computing devices 165 a - c ), one or more buyers in a buyer pool 170 (e.g., accessing network 110 via computing devices 175 a - c ), and/or one or more agents in an agent pool 180 (e.g., accessing network 110 via computing devices 185 a - c ). [0024] Before continuing, it is noted that client computing devices 155 - 185 may include any of a wide variety of computing systems, such as a stand-alone personal desktop or laptop computer (PC), workstation, personal digital assistant (PDA), or appliance, to name only a few examples. Each of the client computing devices may include memory, storage, and a degree of data processing capability at least sufficient to manage a connection to the broker application 130 either directly via network 110 to host 120 or indirectly (e.g., via network site 140 ). Client computing devices may connect to network 110 via a communication connection, such as a dial-up, cable, or DSL connection via an Internet service provider (ISP). [0025] In an exemplary embodiment, a content creator 150 may upload his or her creative content to the host 120 . Broker application 130 processes the creative content and delivers the creative content to one or more other users. For example, one or more peer reviewers and/or contract reviewers (e.g., industry experts or other qualified reviewers) in the reviewer pool 160 may be invited (e.g., via email) to review the creative content. The broker application 130 may process the reviews and provide feedback to the content creator. In another example, one or more content partners (e.g., buyers 170 or agents 180 ) may be invited to review, purchase rights to the creative content, etc. The broker service may also facilitate a partnership between the content creator and the content partner. [0026] It is noted that the client “pools” 150 - 180 in FIG. 1 are shown only for purposes of illustration and are not intended to be limiting. For example, in addition to “dedicated” (or contract) reviewers, a reviewer may also be a member of the content creator pool 150 , the buyer pool 170 and/or the agent pool 180 . [0027] FIG. 2 is a schematic illustration of functional modules of a broker application. Exemplary broker application 200 may be implemented in computer-readable program code executable by one or more computing systems in a network such as, e.g., the Internet. For example, broker application 200 may be a web-based application executing at a network server (e.g., server 122 in FIG. 1 ) and various functional modules may be implemented as applets executing at a computing device (e.g., computing devices 155 - 185 in FIG. 1 ). [0028] Briefly, broker application 200 may receive creative content 210 from a user in electronic format (e.g., jpg for graphics, pdf for text, mpeg for audio/visual). Creative content 210 may include, for example, but is not limited to literary compilations or television/movie scripts 212 , photographs or paintings 214 , audio and/or video works 216 , or any of a wide variety of other works. [0029] Creative content 210 may be stored in computer-readable storage 220 , where it may be accessed by the broker application 200 . For example, broker application 200 may access creative content 210 and provide it to reviewers, agents, studios, and/or buyers. The creative content 210 may be stored for a predetermined duration, allowing users to search online archives of creative content. The creative content 210 may be purged after a predetermined time to free storage. [0030] Broker application 200 may also generate a variety of output 245 for the user. For example, broker application 200 may compile feedback 246 for the content providers based on review of the creative content 210 . Broker application 200 may also generate contracts 247 for facilitating a partnership between a content creator and content partner. Other output 248 may also be provided to a user, such as, e.g., sales materials, contact information, reports, etc. [0031] Broker application 200 may be implemented as one or more functional modules, as illustrated in FIG. 2 . In an exemplary embodiment, broker application 200 may include an interface module 260 . Interface module 260 may include a graphical user interface (GUI), e.g., in a web browser. Interface module 260 may be provided to interface with users. [0032] Interface module 260 may be operatively associated with a number of different modules. For example, interface module 260 may be operatively associated with a registration module 261 to register users with the broker service, an authentication module 262 to verify a user's credential during registration, and a processing module 263 for processing the registration and generating a user profile (see, e.g., FIG. 3 ). Interface module 260 may also be operatively associated with other functional modules (not shown), such as, e.g., a payment processing module for implementing a fee structure for the broker service. [0033] Registration module 261 may be implemented to register one or more users with the broker service. For example, users may register as content creators who submit creative content, reviewers who review creative content and provide feedback to the content creator, agents or studios who may be interested in representing content creators, and/or buyers who may be interested in purchasing creative content. [0034] During registration, the broker application 200 may receive information about the user. Content creators may also be required to agree to a terms of use policy and/or legal disclaimer before receiving the creative content 210 . In an exemplary embodiment, the user may also be provided with basic information on protecting his or her intellectual property rights in the creative content before receiving the creative content 210 . Content partners may also be required to agree to a terms of use policy and/or legal disclaimer, e.g., regarding the artist's rights. [0035] Broker application 200 may use the user registration to build one or more reviewer data stores 230 for inviting reviewers 240 . Reviewers 240 may register with the broker service to be listed in the reviewer data stores 230 . In an exemplary embodiment, other artists may register as peer reviewers 232 , and agents, buyers, or other industry experts may register as contract reviewers 234 . Peer reviewers 232 may receive free or reduced rate review of their own creative content in exchange for registering as a peer reviewer. Contract reviewers 234 may be paid or receive other benefits for reviewing creative content. By way of example, other benefits may include agents or buyers having priority access to fresh creative content before others in the industry have access to it. [0036] Broker application 200 may also use the client registration to build one or more partner data stores 250 for matching the user with a content partner (e.g., an agent or buyer). Content partners may register with the broker application 200 to be listed in the partner data stores 250 . In an exemplary embodiment, agents, buyers, other industry experts, and even other artists may register as content partners. Partners may register under one or more categories (e.g., by genre). Partners may be selected based on any number of criteria. For example, a content partner may receive priority access to the creative content (e.g., for bidding) if the content partner previously reviewed the creative content. Partners may also pay a fee for a higher position in the partner data store 250 . [0037] Optionally, the broker application 200 may also receive information about the creative content 210 being submitted. This registration information may be used to categorize and better manage the creative content 210 and to invite reviewers, agents (or studios), and buyers having a relevant background to review, purchase, etc. the creative content 210 . In another exemplary embodiment, broker application 200 uses registration information to aid in identifying creative content 210 as average, good, or excellent (e.g., based on the content creator's background or prior submission history) inviting reviewers to review the creative content 210 . [0038] Broker application 200 may also include a content manager 264 for managing creative content 210 that is received from content creators, e.g., after registration. For example, content manager 264 may be implemented to import creative content 210 in electronic format, store the creative content 210 in content storage 220 , and invite reviewers and/or partners to review, offer to buy, etc. the creative content 210 . [0039] Broker application 200 may also include a reviewer engine 270 . Reviewer engine 270 may be operatively associated with reviewer data stores 230 to identify reviewers (e.g., peer reviewers 232 or contract reviewers 234 ). Reviewer engine 270 may include a reviewer sort module 275 to identify reviewers listed in the reviewer data stores 230 and invite reviewers to review creative content 210 . [0040] Reviewers 240 may provide their reviews of the creative content 210 to the broker application 200 for processing. In an exemplary embodiment, the review may include a content ranking (e.g., on a scale of 1 to 10) in one or more categories (e.g., sound or video quality, overall presentation). The review may be received from the reviewers 240 at I/O 280 and processed to compiling feedback 246 for the user. Broker application 200 may deliver the feedback 246 to the user, e.g., via email, notification upon login, or by the user accessing a webpage to view the feedback 246 . [0041] Broker application 200 may also include a partner engine 290 . Partner engine 290 may be operatively associated with partner data stores 250 to identify content partners (e.g., agents 252 or buyers 254 ) for the user's creative content. Partner engine 290 may include a partner sort module 295 to identify partners listed in the partner data stores 250 . Operation of the partner engine 290 and partner sort module 295 is similar to operation of the reviewer engine 270 and reviewer sort module 275 , and both are explained in more detail below with reference to FIG. 4 . [0042] Broker application 200 may also be implemented to partner a user and content partner (e.g., agent or buyer). In an exemplary embodiment, broker application 200 may deliver contact information for the user to the potential agent or vice versa. Alternatively, broker application 200 may mediate communication between the user and content partner (e.g., to protect the anonymity of either or both the user and partner). In another exemplary embodiment, broker application 200 may deliver the contact information for both parties to an advisor (e.g., one or more attorneys) to handle further interactions (e.g., contract negotiations) for the user and content partner. [0043] It is noted that exemplary broker application 200 is shown and described herein for purposes of illustration and is not intended to be limiting. For example, the functional components shown in FIG. 2 do not need to be encapsulated as separate modules. In addition, other functional components (not shown) may also be provided and are not limited to those shown and described herein. [0044] FIG. 3 is a block diagram illustrating a user registration and corresponding user profile. Exemplary user registration 300 may be generated as part of an interactive registration process between the broker service and a user, such as, e.g., by the user entering data into form fields in an electronic form provided by the broker service on an Internet site. The user registration 300 and user profile 350 may be implemented, e.g., to register a user with the broker service as a content provider, a reviewer, and/or a content partner. [0045] User registration 300 may include one or more data categories. Exemplary data categories may include, but are not limited to, identifying information 310 , matching criteria, 320 , qualifications 330 , and content interest 340 . It is noted that any number of data categories 310 - 340 may be provided to solicit information from a user registering with the broker service. [0046] Data categories 310 - 340 may also include one or more subcategories. For purposes of illustration, the identifying information data category 310 may include a name subcategory 312 (for the user's name) and a firm subcategory 314 (for an agency name, if applicable). Other subcategories (not shown) in the identifying information data category 310 may include, e.g., mailing address, email address, telephone number, etc. [0047] The matching criteria category 320 enables the user to select one or more types of registration, e.g., as an agent 322 , a reviewer 324 , and/or a buyer 326 . The qualifications category 330 requests the user to specify, e.g., industry experience 332 , and industry memberships 334 . [0048] The content interest category 340 enables the user to select one or more types of creative content the user is interested in receiving. In an exemplary embodiment, content interest category 340 may be implemented as a menu structure 341 . The user may click on types of content (e.g., visual works 342 or literary works 343 ) to display a more detailed listing of content available from the broker service. In FIG. 3 , for example, the user has selected visual works 342 , and then paintings 344 , to display landscapes 345 and portraits 346 . Likewise, the user could select photographs 347 or computer graphics 348 . [0049] Before continuing, it is noted that the user registration 300 in FIG. 3 is shown for purposes of illustration only, and is not intended to be limiting in scope. Although providing more detailed data during the registration process may allow the broker service to better match the user with creative content, the user registration 300 is not limited to any particular format or level of detail. [0050] The user registration 300 may be processed to generate a user profile 350 . User profile 350 may be implemented as a computer readable data structure (e.g., an XML file) including a number of data fields. In an exemplary embodiment, data fields may include a user ID field 360 , user qualifications field 370 , user rank field 380 , user history field 390 , and content interest field 395 . [0051] The fields 360 - 395 may be generated based on registration data provided by the user, e.g., in the user registration 300 . The registration data may also be included in subfields corresponding to each of the fields 360 - 395 . For example, the user ID field 360 may include subfields 361 - 363 and user qualifications field 370 may include subfields 371 - 372 . More than one level of subfields may also be included. For example, the content interest field 395 may include a photographs subfield 396 and, under that, a portraits subfield 397 . Subfields 398 , 399 are also shown for purposes of illustration. [0052] In an exemplary embodiment, the user rank 380 may be determined by the broker service based on registration data provided by the user, e.g., in the user registration 300 . For example, an agent's rank may be based on how long the agent has been registered with the broker service (e.g., agent history), prior successes in the industry, prior successes with the broker service, industry memberships and other qualifications, standing in the industry, user feedback, credibility (e.g., an agent specializing in cartoons may not be a credible agent for horror films), fees charged, fees paid (e.g., a subscription to the broker service), and/or firm size, to name only a few examples. In another example, a buyer's rank may be based on how long the buyer has been registered with the broker service (e.g., buyer history), recent purchases using the broker service or otherwise, and price the buyer is willing to pay, to name only a few examples. [0053] In another exemplary embodiment, the user history 390 may be generated by the broker service based on registration data provided by the user and/or during operation. For example, the user history 390 may be based on an agent's proclivity for negotiating contracts or a buyer's purchasing history. The user history 390 may be updated based on events occurring after the initial registration (e.g., a sale using the broker service). [0054] The user profile 350 may be implemented by the broker service for a number of different purposes. For example, the broker service may access the user profile 350 to identify reviewers, agents, and/or buyers for creative content that has been submitted by a content creator. The broker service may also access the user profile 350 for an agent (or buyer) to determine an agent's (or buyer's) rank relative to other agents (or buyers) before inviting an agent (or buyer). The broker service may also access the user profile 350 to match the user with content (e.g., to review, purchase, or represent as an agent) based on the user's desires, qualifications, and/or experience. The user profile 350 may also be used to facilitate a relationship (e.g., between an agent and a content creator). [0055] FIG. 4 is a high-level diagram illustrating queues for brokering creative content online. One or more queues 400 , 410 , and 420 may be implemented by the broker service to automatically categorize and invite reviewers and/or to match users with content partners. [0056] Queues 400 , 410 , 420 may be populated with data entries. In an exemplary implementation, the data entries identify reviewers. Separate queues may be used for separate categories (and/or subcategories) so that a reviewer registered to receive creative content in a particular category (e.g., based on interest, experience, etc.) is placed into the corresponding queue. For purposes of illustration, reviewers registered for music may be placed into queue 400 , reviewers registered for literary works may be placed into queue 410 , and reviewers registered for visual art works may be placed into queue 420 . Of course any number of queues and sub-queues may be implemented (e.g., for different genre within a category such as music). [0057] Broker service may include one or more sort modules (e.g., reviewer sort 275 in FIG. 2 ) to automatically identify reviewers using one or more filters in conjunction with the queues 400 , 410 , 420 . In an exemplary embodiment, the broker service may automatically determine a category of the creative content (e.g., based on file extension, user responses provided in a survey, etc.). The category (and/or subcategory) may be passed to a category filter 430 which “points” to one or more queues corresponding to the category (and/or subcategory). Once the appropriate queue(s) have been selected by the category filter 430 , a position filter 440 “points” to one or more position within the selected queue (e.g., queue position 412 in FIG. 4 ) to identify a reviewer for the creative content. In an exemplary implementation, the position filter 440 “points” to a position in the queue based on a first-in first-out (FIFO) or round robin scheme, although other algorithms may also be implemented (e.g., based on the reviewer's experience, history with the brokering system, a fee-basis, etc.). Queue position 412 may also include contact information (e.g., an email or physical address) for the reviewer enabling the broker service to invite the identified reviewer. Alternatively, the user profile may be invoked to retrieve contact information. [0058] It is noted that a similar queuing mechanism may be implemented for identifying content partners. That is, content partners may register in one or more categories (e.g., based on interest, experience, etc.) and be listed in the corresponding queue. Again, the content partner's position in the queue may be determined on a FIFO basis or other suitable algorithm (e.g., paid subscribers may receive a higher position in the queue than non-paying subscribers). In an exemplary implementation, it is in the interest of the content partner to be selected more frequently and ahead of other content partners to increase their odds of discovering “new talent.” [0059] It is noted that the exemplary systems discussed above are provided for purposes of illustration. Still other implementations are also contemplated. [0000] Exemplary Operations [0060] FIG. 5 is a flowchart illustrating exemplary operations which may be implemented for having creative content reviewed. Operations 500 may be embodied as logic instructions on one or more computer-readable medium. When executed on a processor, the logic instructions cause a general purpose computing device to be programmed as a special-purpose machine that implements the described operations. In an exemplary implementation, the components and connections depicted in the figures may be used for brokering creative content online. [0061] In operation 510 , creative content may be received, e.g., by the broker service. For example, the creative content may be uploaded in electronic format over a networked computer system. In operation 520 , the creative content may be provided to peer reviewers and/or contract reviewers. In an exemplary embodiment, reviewers may be self-categorized during a registration process thereby enabling the system to invite reviewers who have expressed an interest in the subject matter, have a particular background or experience with the subject matter, may be interested in purchasing the subject matter or representing the creator, etc. [0062] In operation 525 , feedback may be received from the reviewers, and in operation 530 , the feedback may be compiled for the user. For purposes of illustration, reviewers may provide feedback via a standardized review form. The standardized review form may include a number of categories and enable the reviewer to indicate a score in each of the categories. For example, the reviewer may provide scores for a literary work on a scale of 1 to 10 in the following areas: writing style, plot, audience appeal, etc. Any number of categories may be provided, striking a balance between the time required to provide feedback and a review that is meaningful to the content creator. Although use of a standardized review form is not required, such use lends itself well to computerized compilation techniques, e.g., allowing the system to provide the content creator with standardized feedback (e.g., an overall score or content ranking). In other examples, the reviewers may provide written comments, marked-up versions containing comments and suggestions, etc. [0063] In operation 540 , a determination is made whether a content partner is interested in the creative content. Content partners may include potential buyers, distributors, agents, etc. In another example, another user accessing the broker service may express interest in the creative content posted online before, during, or after review. As explained above for the reviewers, content partners may also be self-categorized during a registration process thereby enabling the system to match creative content to content partners who have expressed an interest in the subject matter, have a particular background or experience with the subject matter, may be interested in purchasing the subject matter or representing the creator, etc. [0064] If a content partner is not available for the creative content, operations may end at step 550 . For example, the creative content may be returned to the user and/or removed from storage at the broker service. If a content partner is available for the creative content, the user may be matched with the content partner in operation 560 . In an exemplary embodiment, the broker service may provide contact information to the content creator and/or content partner(s). In another exemplary embodiment, the broker service may provide “live” assistance with contract negotiations. [0065] In an exemplary embodiment, a fee structure may also be implemented for one or more of the operations shown in FIG. 5 . For purposes of illustration, a fee may be charged for accepting creative content in operation 510 , e.g., to cover the cost of storage. Content creators may also be charged a fee to have their biography (links to their web page, etc.) posted online along with their creative content. A fee may also be charged for the review in operation 520 . For example, the content creator may be charged a fee to skip peer review and have his or her creative content reviewed by contract reviewers. In addition, different fees may be charged for various levels of review, and or resubmitting the same creative content after it has been modified based on a previous review. A fee may also be charged for matching the content creator with a content partner and/or any follow-on deals brokered with content partners matched by the broker service. Alternatively, a portion of transaction fees (e.g., sales, contracts) may be collected for matching the user with a content partner. Content partners may also be charged a listing fee. [0066] FIG. 6 is a flowchart illustrating exemplary operations 600 which may be implemented for matching an agent with creative content. An agent may be an independent agent (or agency) or a studio. The operations described below with reference to FIG. 6 may be implemented for independent agents (or agencies) and studios. [0067] In operation 610 , an agent registration may be received, e.g., by the broker service. For purposes of illustration, the agent registration may identify the agent (e.g., agency name, size, fees charged, etc.), provide agent qualifications (e.g., industry experience, industry memberships, prior success in the relevant industry, etc.), and identify content interest (e.g., genre and subcategories). [0068] In operation 620 , the agent may be authenticated. For example, the broker service may verify industry memberships and/or standing in the industry. If the agent cannot be authenticated, the broker service may allow the agent to clarify credentials or provide additional qualifications that can be verified. Alternatively, the agent registration may be rejected in operation 625 . [0069] In operation 630 , an agent profile may be generated. In an exemplary embodiment, the agent profile may be based on processing of the agent registration (e.g., in operation 610 ). The agent profile may include, among other things, the type of content that the agent is seeking. The agent profile may also include an agent rank. [0070] In operation 640 , the agent may be provided access to creative content. In an exemplary embodiment, the agent may be matched with creative content based on the type of content the agent is seeking. For example, the agent profile may be used to match the agent with the desired type of creative content. The agent rank may also be used to provide higher ranking agents with access to the creative content before lower ranking agents. In another exemplary embodiment, the agent may be matched with creative content that has already been reviewed and recommended (e.g., by professional reviewers). This referral process may even be required by some agents (e.g., studios or well-regarded agencies). [0071] In operation 650 , a determination is made whether the agent has accepted (i.e., expressed an interest in) the creative content matched to the agent. If the agent has accepted the creative content, a partnership between the agent and the content creator may be facilitated in operation 655 . If the agent has not accepted the creative content, a determination is made in operation 660 whether the agent has rejected the creative content. [0072] If the agent has rejected the creative content, the broker service may generate a report for the content creator notifying the content creator of the rejection. The report may also include substantive commentary, e.g., for improving and resubmitting the creative content. Alternatively, if the agent has rejected the creative content, the broker service may return to operation 640 and match the agent with other creative content. The broker service may also deliver the rejected creative content to another agent for review (e.g., the next agent in the queue). [0073] If the creative content has not been rejected yet, a determination is made in operation 670 whether a period of exclusivity for reviewing the creative content has expired. The period of exclusivity may be implemented so that the agent may review creative content before it is passed on to other agents. However, if the agent fails to act within a predetermined time (e.g., 5 business days, 1 week, 1 month, etc.) the broker service may automatically invite another agent for review (or return it to the creator). This period of exclusivity encourages the agent to review the creative content in a timely manner and helps keep the creative content “fresh” for other agents who may be positioned later in the queue. [0074] It is noted that the period of exclusivity does not need to be the same for all creative content and may depend on various considerations. For example, the period of exclusivity may depend at least in part on the type of creative content. In another example, the period of exclusivity may depend at least in part on the content creator's reputation, or may even be assigned by the content creator. In addition, studios may have a longer time to review creative content because there are fewer studios than independent agents (or agencies). [0075] If the period of exclusivity has expired, operations may return to operation 640 to match the agent with other creative content. Alternatively, operations may return to operation 650 so that the agent has an opportunity to review the creative content until the period of exclusivity expires. [0076] FIG. 7 is a flowchart illustrating exemplary operations 700 which may be implemented for bidding on creative content. In operation 710 , the broker service may receive and process a buyer registration. As noted above, any user may register as a buyer, including users who are also registered as reviewers and/or agents. For purposes of illustration, the buyer registration may identify the buyer, e.g., by name. The buyer registration may also indicate whether the buyer is a volume buyer (e.g., studio or gallery) and may specify a price range. The buyer registration may also identify content interest (e.g., genre and subcategories). [0077] In operation 720 , the buyer may be authenticated. The broker service may independently authenticate the buyer, e.g., based on prior purchases, or may use external indicators, such as eBay® Internet auction service user ratings. If the buyer cannot be authenticated, e.g., due to a poor payment history, the buyer registration may be rejected. [0078] In operation 730 , a buyer profile may be generated. In an exemplary embodiment, the buyer profile may be based on processing of the buyer registration (e.g., in operation 710 ). The buyer profile may include, among other things, the type of content that the buyer is seeking. The buyer profile may also include a buyer rank. [0079] It is noted that the buyer profile may be used by both the broker service to match the buyer with creative content that interests the buyer, and by the content creator. For example, the content creator may accept a lower bid from a gallery owner over a higher bid from an individual, in the hopes of doing future business with the gallery owner. In another example, the content creator may only accept bids from buyers having a buyer rank that meets a predetermined threshold (e.g., 4 out of 5 stars). [0080] In operation 740 , one or more buyer may be provided access to creative content. In an exemplary embodiment, the buyer may be matched with creative content based on the type of content the buyer is seeking. For example, the buyer profile may be used to match the buyer with the desired type of creative content. The buyer rank may also be used to provide higher ranking buyers with creative content before lower ranking buyers. In another exemplary embodiment, discerning buyers may also be provided with a review and/or recommendation to buy the creative content (e.g., from professional reviewers). [0081] In operation 750 , the broker service may receive one or more bids to buy creative content that has been submitted to the buyers (e.g., in operation 740 ). In operation 760 the bids may be provided to the content creator to accept or reject. If a bid is accepted in operation 770 , a sale between the buyer and the content creator may be facilitated in operation 775 . If the bid has not been accepted, the buyer may be notified and operations may end at 780 . [0082] Optionally, the content creator may provide a counter-offer to a buyer's bid. The broker service may provide the counter-offer to the buyer for consideration, and a sale may be arranged if the buyer accepts the counter-offer. [0083] Also optionally, operations 700 for bidding on creative content may include a period of exclusivity. According to an exemplary embodiment, creative content may be provided to one or more buyers to bid on before being provided to other buyers (e.g., based on rank). For example, the content creator may request bids first from gallery owners, before opening bidding to other buyers. [0084] The operations shown and described herein are provided to illustrate exemplary implementations of brokering creative content online. It is noted that the operations are not limited to the ordering shown. Still other operations may also be implemented for brokering creative content online. [0000] Exemplary Computing Device [0085] FIG. 8 is a schematic illustration of an exemplary computing device that can be utilized for brokering creative content online. Computing device 830 includes one or more processors or processing units 832 , a system memory 834 , and a bus 836 that couples various system components including the system memory 834 to processors 832 . The bus 836 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. The system memory 834 includes read only memory (ROM) 838 and random access memory (RAM) 840 . A basic input/output system (BIOS) 842 , containing the basic routines that help to transfer information between elements within computing device 830 , such as during start-up, is stored in ROM 838 . [0086] Computing device 830 further includes a hard disk drive 844 for reading from and writing to a hard disk (not shown), and may include a magnetic disk drive 846 for reading from and writing to a removable magnetic disk 848 , and an optical disk drive 850 for reading from or writing to a removable optical disk 852 such as a CD ROM or other optical media. The hard disk drive 844 , magnetic disk drive 846 , and optical disk drive 850 are connected to the bus 836 by a SCSI interface 854 or some other appropriate interface. The drives and their associated computer-readable media provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for computing device 830 . Although the exemplary environment described herein employs a hard disk, a removable magnetic disk 848 and a removable optical disk 852 , other types of computer-readable media such as magnetic cassettes, flash memory cards, digital video disks, random access memories (RAMs), read only memories (ROMs), and the like, may also be used in the exemplary operating environment. [0087] A number of program modules may be stored on the hard disk 844 , magnetic disk 848 , optical disk 852 , ROM 838 , or RAM 840 , including an operating system 858 , one or more application programs 860 , other program modules 862 , and program data 864 . A user may enter commands and information into computing device 830 through input devices such as a keyboard 866 and a pointing device 868 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are connected to the processing unit 832 through an interface 870 that is coupled to the bus 836 . A monitor 872 or other type of display device is also connected to the bus 836 via an interface, such as a video adapter 874 . [0088] Computing device 830 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 876 . The remote computer 876 may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to computing device 830 . The logical connections depicted include a LAN 880 and a WAN 882 . [0089] When used in a LAN networking environment, computing device 830 is connected to the local network 880 through a network interface or adapter 884 . When used in a WAN networking environment, computing device 830 typically includes a modem 886 or other means for establishing communications over the wide area network 882 , such as the Internet. The modem 886 , which may be internal or external, is connected to the bus 836 via a serial port interface 856 . In a networked environment, program modules depicted relative to the computing device 830 , or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. [0090] Generally, the data processors of computing device 830 are programmed by means of instructions stored at different times in the various computer-readable storage media of the computer. Programs and operating systems may distributed, for example, on floppy disks, CD-ROMs, or electronically, and are installed or loaded into the secondary memory of a computer. At execution, the programs are loaded at least partially into the computer's primary electronic memory. [0091] In addition to the specific implementations explicitly set forth herein, other aspects and implementations will be apparent to those skilled in the art from consideration of the specification disclosed herein. It is intended that the specification and illustrated implementations be considered as examples only, with a true scope and spirit of the following claims.

Systems and methods of partnering content creators with content partners online are disclosed. In an exemplary implementation a method may include receiving registration information from a content partner and building a profile describing desired creative content for the content partner and receiving creative content. Based on at least the profile, the method may include determining whether a match exists between a content partner and the creative content. If a match is found, the method may include providing the content partner access to the creative content, and extending an invitation for the content partner to acquire rights in the creative content.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/678,321, filed May 6, 2005, the entire disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] This invention relates to the navigation of medical devices through body lumens and cavities, and in particular to an interface for controlling remote navigation systems for navigating medical devices through body lumens and cavities. [0003] Remote navigation systems have been developed which allow a user to remotely orient the distal end of a medical device and thereby navigate the device through a subject's body lumen or cavity, and particularly the subject's vasculature. In particular, magnetic navigation systems have been developed by Stereotaxis, Inc., that apply a strong magnetic field in a selected direction to orient the distal end of a medical device provided with a magnetically responsive element. These magnetic navigation systems provide fast and accurate remote control over the distal end of the medical device. Other attempts have been made to provide remotely navigable medical devices, including devices employing conventional pull wires and push wires, and other mechanical means for remotely orienting the distal end of a medical device. Thus, while the technology is available to remotely navigate medical devices, the in certain circumstance it can be difficult for the physician or other health care worker to visualize the procedure site, and more specifically to indicate to the remote navigation system the desired direction of orientation of the distal end of the medial device. SUMMARY OF THE INVENTION [0004] Embodiments of the present invention provide an interface to facilitate the control of medical devices and in particular the control of remotely controlled medical devices. Generally, the interface of the present invention comprises a display of a view from inside the body lumen or cavity (an “endoluminal view”) in the vicinity of the distal end of the medical device. This view may be an actual image from inside the body lumen or cavity, but in the preferred embodiment, it is a reconstructed view from preoperative or intraoperative imaging. This view preferably includes an image of the distal end portion of the medical device. The image of the distal end portion of the medical device may be an actual image of the distal end portion obtained with or separately from the image of the body lumen or cavity. The image of the distal end portion of the medical device is preferably a generated image of the device based upon a model of the device and the current state of the remote navigation system. This combined view of the body lumen and cavity allows the physician or other user more easily understand the current position and orientation of the medical device, and to determine the desired new direction of orientation. [0005] In a first preferred embodiment, a plurality of control buttons are associated with the displayed image. These control buttons can be physical buttons, they can be “virtual” buttons on which the physician or other user can point with a cursor or other indicator and “click”, or they can be defined locations on a touch screen display which the user can operate by touching either with a finger or a stylus. In the preferred embodiment these buttons are arranged around the periphery of the image, and their positions indicate the direction they control. They may also be shaped to visually reinforce the direction associated with the particular button. If the user desires to re-orient the tip of the device in a particular direction, the user simply operates the corresponding button. The displayed image of the medical device updates as the remote navigation system changes the orientation of the distal end portion of the medical device. The buttons could operate in a discrete mode where each operation or “click” changes the orientation in the selected direction by a predetermined amount, or the buttons could operate in a continuous mode where the direction changes as long as the button is held down. [0006] In a second preferred embodiment, the surface of the displayed endoluminal image is active, and when the physician or user identifies a particular point on the image, the remote navigation system orients the distal tip of the device to point toward the selected point. The active surface can be one in which the user points and clicks a cursor, or alternatively it can be touch screen on which the user indicates the desired direction with a finger or a stylus. [0007] In a third preferred embodiment, both the buttons of the first preferred embodiment and the active image of the second preferred embodiment are provided to provide dual modes of control of the remote navigation system. [0008] Thus, the interface and control methods of the various embodiments of the present invention allows the user to visualize and to control the orientation of a distal end of the medical device as it is being navigated in a body lumen or cavity. The interfaces and controls allows the user to more quickly and easily indicate to a remove navigation system the desired orientation of the medical device to facilitate the navigation of a medical device through the body lumen or cavity. BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIG. 1 is a view of a computer screen illustrating one possible implementation of the interface and methods of the present invention; [0010] FIG. 2 is a view of a computer screen illustrating a second possible implementation of the interface and methods of the present invention; [0011] FIG. 3 is a view of a first preferred embodiment of an interface implementing a first control method in accordance with the principles of this invention; [0012] FIG. 4 is a view of a second preferred embodiment of an interface implementing a second control method in accordance with the principles of this invention; [0013] FIG. 5 is a view of a third preferred embodiment of an interface implementing a third control method in accordance with the principles of this invention; and [0014] FIG. 6 is a view of a computer interface illustrating the location display method in accordance with the principles of the present invention. [0015] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0016] A computer screen illustrating a possible implementation of the interface and methods of the present invention is shown in FIG. 1 . As shown in FIG. 1 the interface comprises a main pane 20 for implementing the interface and methods of the various embodiments of the present invention. The pane 20 can have a tool bar 22 . There is an auxiliary pane 24 , and a main tool bar 26 . Another computer screen illustrating a possible implementation of the interface and methods of the present invention is shown in FIG. 2 . As shown in FIG. 2 , the interface includes main panes 50 and 52 . Pane 50 is adapted for implementing the interface and methods of the various embodiments of the present invention. Pane 52 includes a display of an external view of the body lumen or cavity, to further facilitate the physician or other user understanding the position and orientation of the medical device. There is preferably an auxiliary pane 54 , a navigation direction window 56 , and a tool bar 58 . [0017] FIG. 3 shows the implementation of a first preferred embodiment of an interface and method in accordance with the principles of the present invention. The interface comprises a display 100 of an image from inside the body lumen or cavity (an “endoluminal” view) in the vicinity of the distal end of the medical device. This view may be an actual image from inside the body lumen or cavity, but in the preferred embodiments, it is a reconstructed view from preoperative or intraoperative imaging. This preoperative imaging may be x-ray imaging, M imaging, ultrasound imaging, CT imaging, rotational angiographic imaging or any other imaging modality. As shown in the Figures, the images 100 are generally circular, which is usually preferable because of the generally circular cross-section of most body lumens and cavities. However, the image 100 could have some other shape, such as oval, rectangular, or polygonal. The image preferably shows deformities, deposits, blockages and partial blockages of the vessels. [0018] The display 100 also includes an image 102 of the distal end portion of the medical device. The image of the distal end portion of the medical device may be an actual image of the distal end portion obtained with or separately from the image of the body lumen or cavity. The image of the distal end portion of the medical device is preferably a generated image of the device based upon a model of the device and the current state of the remote navigation system. The modeling and display is disclosed in U.S. patent application Ser. No. 10/448,273, filed May 29, 2003, incorporated herein by reference. Alternatively, the orientation and or position can be determined by various localization methods, including rf localization, electrostatic localization, optical localization, ultrasound localization, or the like. In the case of navigation through a constrained lumen, such as a blood vessel, the position and orientation may be know simply from the extended length of the medical device, which is many cases is a good indicator of the position and thus the orientation of the distal end of the medical device. [0019] The combined view of the body lumen and cavity allows the physician or other user more easily understand the current position and orientation of the medical device, and to determine the desired new direction of orientation. [0020] In this first preferred embodiment, a plurality of control buttons 104 are associated with the displayed image. These control buttons 104 can be physical buttons. Alternatively, these control buttons 104 can be “virtual” buttons on which the physician or other user can point with a cursor or other indicator and “click”. Alternatively, these control buttons 104 can be defined locations on a touch screen display which the user can operate by touching either with a finger or a stylus. In the preferred embodiments these buttons are arranged around the periphery of the image, and the positions of the button indicate the direction they control. They may also be shaped to visually reinforce the direction associated with the particular button. As shown in FIG. 3 , the buttons have a triangular shape, with the base along the perimeter of the image, and one apex of the triangle, pointing in the direction of movement that the button controls. [0021] If the user desires to re-orient the tip of the device in a particular direction, the user simply operates the button 104 in the direction corresponding to the desired direction of movement. The displayed image 102 of the medical device updates as the remote navigation system changes the orientation of the distal end portion of the medical device. The buttons 104 can operate in a discrete mode where each operation or “click” of the button changes the orientation in the selected direction by a predetermined amount. Alternatively, or in addition, the buttons 104 could operate in a continuous mode where the direction changes as long as the button is held down. [0022] Thus, as shown in FIG. 3B , the user manipulates a cursor to the button 104 corresponding to the desired direction of movement, and clicks. The interface instructs the remote navigation system, e.g. a Stereotaxis magnetic navigation system, or a mechanical navigation system, to change the orientation of the distal tip in the indicated direction. As shown in FIG. 3C the distal end of the device is reoriented by the remote navigation system. The user can then advance the medical device in the selected direction, or make further adjustments to the orientation of the distal end of the device. [0023] In the second preferred embodiment shown in FIG. 4 , the surface of the displayed endoluminal image is active, and when the physician or user identifies a particular point on the image, the remote navigation system orients the distal tip of the device to point toward the selected point. The active surface can be one in which the user points and clicks a cursor, or alternatively it can be touch screen on which the user indicates the desired direction with a finger or a stylus. Thus as shown in FIG. 4B , the user can indicate a desired destination point on the image 100 by positioning a cursor on the desired destination and clicking. The interface instructs the remote navigation system, e.g. a Stereotaxis magnetic navigation system, or a mechanical navigation system, to change the orientation of the distal tip in the indicated direction. As shown in FIG. 4C , the distal end of the device is reoriented by the remote navigation system. The user can then advance the medical device to the selected destination, or make further adjustments to the orientation of the distal end of the device. [0024] In the third preferred embodiment, shown in FIG. 4 , the surface of the displayed endoluminal image is active, and there are also a plurality of buttons 104 . The third preferred embodiment gives the user at least two alternative ways of orienting the distal end of a medical device. The user can directly control the direction of the distal tip by manipulating the buttons 104 to achieve the desired orientation. Alternatively, the user can automatically control the distal tip by picking a destination point. In either case the interface communicates the user's selection to the remote navigation system which moves the distal end of the medical device as specified. The user can then advance the medical device, or alternatively device advancement could be automatically applied by the navigation system. [0025] To facilitate the navigation of a medical device through body lumens and cavities, it is desirable to clearly indicate to the physician or other user where the distal end of the device is presently located. Thus in accordance with one embodiment of the present invention, an external image 200 of a body lumen or cavity is displayed. The position of the medical device is determined by any conventional means of localization, including using rf signals, electrostatic localization, optical localization, image processing localization, etc. In the case of navigating through a relatively constricted lumen, such as a blood vessel, the position in the vessel can be determined by measuring the extended length of the device, as advancement of a given length will substantially correspond to the same advancement along the centerline of the vessel. The advancement of the medical device can be measured in a number of ways. If the device is advanced by machine, for example opposed rollers as disclosed in U.S. patent application Ser. No. 10/138,710, filed May 3, 2002, and U.S. patent application Ser. No. 10/858,485, filed Jun. 1, 2004, (the disclosures of which are incorporated by reference), then the rotation of the rollers can be used to measure the advancement of device. Alternatively, marks can be provided on the device which can be physically, electrically, optically, or otherwise sensed to measure the advancement of the medical device. [0026] As shown in FIG. 6 , a ring 202 is superimposed on the displayed image of the body lumen corresponding to the position of the distal end of the medical device. This ring is positioned in the plane perpendicular to the centerline of the lumen at the location of distal end of the medical device. The ring 202 on the image 202 helps the physician visualize the current location of the medical device. [0027] Operation [0028] In operation as a medical device is being navigated through a body lumen or cavity such as a blood vessel, an endoluminal view 100 of the blood vessel is displayed. The user can view the relative position of the image 102 of the medical device in the endoluminal view 100 . If there is a blockage or partial blockage, the user can use the buttons 104 to adjust or suitably bias the orientation of the distal end of the device to navigate past the blockage. Alternatively, the user can click on the image 100 to adjust the orientation of the distal end of the device to navigate past the blockage. When the user reaches a branch in the blood vessel the user can navigate to and through a branch either by adjusting the orientation of the distal end of the device using buttons 104 or by adjusting the orientation of the device by pointing to the branch on the image 100 and clicking. The user interface causes the remote navigation system to change the oritentation of the distal end of the device so that it can be advanced through the vessel or other lumen or cavity, following the centerline of the path and easily steering around vascular obstructions past branches and bifurcations. To facilitate the user's operation of the interface, the interface preferably only displays and manipulate device direction.

A method of controlling a remote navigation system that remotely orients the distal end of the medical device in order to navigate a medical device through a body lumen includes displaying an endoluminal image of the portion of the body lumen through which the device is being navigated, including an image of the distal end of the medical device; displaying a plurality of directional controls associated with the displayed endoluminal image; and accepting inputs of a selected direction of change of orientation of the distal tip from the directional controls and in response operating the remote navigation system to change the direction of orientation of the distal end of the medical device in the selected direction. The distal end of the device may alternatively or additionally be oriented to point toward a point corresponding to a point that the user identifies on the displayed endoluminal image.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to sequence controllers of the digital logical circuit type, in which the desired sequence instruction is read from its sequence program part, and the sequence is processed and controlled in its processing circuit. 2. Description of the Prior Art Being indispensable in the present-day industrialized society, the sequence control technique is widely used in the field of industrial process control, such as power plant and substation control, conveyor system control, machine tool control, assembly line control in the automotive plant, and rolling line control. For these controls, the contact relay sequence control has long been used. This type of sequence control, however, is inconvenient for applications where design modifications are often made on a control system, resulting in degradation of reliability. Recently, the controlled objectives have become much more sophisticated which has necessitated the use of an increasing number of relays, with the result that the logical design has become intricate and the approach to higher speed control has become more difficult. One solution to this problem in the prior art is the sequence controller with computer-like control functions adapted to sequence controls, in which a program (i.e., a pattern of sequence control operation) is stored in a core memory by way of the keyboard according to a predetermined specific format, the process state is sampled at certain time intervals and compared with the stored data, and an output is generated according to the result. This sequence controller operates in general on flow-chart system or Boolean algebraic system (conversion system) through programming. When a relay sequence is programmed for a computer, the necessary logical operation is expressed in terms of Boolean algebra, which is programmed and stored in a core memory of the sequence controller. This Boolean algebraic system offers high processing efficiency. This programming control will be described by way of example with reference to FIGS. 1 through 3. A sequence diagram as shown in FIG. 1 may be expressed by Boolean algebraic equations as follows. Y.sub.1 = (X.sub.1 + X.sub.3).sup.. X.sub.2 = X.sub.1 .sup.. X.sub.2 + X.sub.3 .sup.. X.sub.2 ( 1) y.sub.2 = x.sub.4 .sup.. x.sub.5 + x.sub.6 ( 2) where X 1 to X 6 stand for input contacts, among which X.sub., X 3 , X 4 and X 5 are make-contacts which close the individual circuits when the coil is excited, and X 2 and X 6 are break-contacts which open the individual circuits when the coil is excited; and Y 1 and Y 2 denote output relays. FIG. 2 is a block diagram showing a conventional digital logical circuit type sequence controller with functions equivalent to those of the above-mentioned relay sequence circuit. In FIG. 2, X 1 , X 2 , X 3 , . . . denote contacts of external inputs, and the numeral 1 represents an input selection circuit which selects the necessary input contact and supplies datum of the state of the selected input contact to a logical processing circuit 2 which is capable of performing a given sequence processing. The numeral 3 denotes an output control circuit which holds the specific output relays Y 1 and Y 2 in on or off state according to the processed result reached by the processing circuit 2. The numeral 4 represents a sequence program storage circuit which stores sequence programs and reads them in sequence and supplies the read program to the processing circuit 2. An example of this processing circuit is illustrated in block form in FIG. 3, in which FF 1 , FF 2 and FF 3 denote flip-flop circuits, AND a logical AND circuit, OR a logical OR circuit, and G 1 to G 5 gates. This circuit performs processing as summarized below in reference to Y 1 as in Eq. (1). Memory Address Sequence Instruction Processing______________________________________1 LOAD X.sub.1 1 X.sub.1 →FF.sub.1 2 FF.sub.1 →FF.sub.2 3 O→FF.sub.32 AND X.sub.2 1 X.sub.2 →FF.sub.1 2 FF.sub.1. FF.sub.2 →FF.sub.23 OR X.sub.3 1 X.sub.3 →FF.sub.1 2 FF.sub.2 + FF.sub.3 →FF.sub.3 3 FF.sub.1 →FF.sub.24 AND X.sub.2 1 X.sub.2 →FF.sub.1 2 FF.sub.1. FF.sub.2 →FF.sub.25 SET Y.sub.1 2 FF.sub.2 + FF.sub.3 →FF.sub.3 3 FF.sub.3 →OUT Y.sub.1______________________________________ (Note: The numerals 1 , 2 , and 3 indicate the timing sequence for the processing.) When a sequence instruction LOAD X 1 at memory address 1 is read from a memory in the sequence program storage circuit 4, this instruction is decoded and the state of input contact X 1 is stored in the flip-flop FF 1 . Then the gates G 1 and G 3 are opened whereby the data in the flip-flop FF 1 is transferred to the flip-flop FF 2 , and the binary code "0" is stored as an initial set signal in the flip-flop FF 3 . Then, when another sequence instruction AND X 2 at address 2 is read from a memory in the sequence program storage circuit 4, the state of complement X 2 of input contact X 2 is stored in the flip-flop FF 1 , and the gate G 2 is opened whereby the flip-flops FF 1 and FF 2 undergo AND logic and the result is stored in the flip-flop FF 2 . The state of input contact X 3 is stored in the flip-flop FF 1 by another sequence instruction OR X 3 . Then the gate G 4 is opened whereby the flip-flops FF 2 and FF 3 undergo OR logic, and the result is transferred to the flip-flop FF 3 . After this step, the gate G 1 is opened whereby the datum stored in the flip-flop FF 1 is transferred to the flip-flop FF 2 . When an instruction AND X 2 at address 4 is read, the same processing as performed by the instruction at address 2 is carried out. Then, when an instruction SET Y 1 at address 5 comes in, the gate G 4 is opened whereby the flip-flops FF 2 and FF 3 undergo OR logic, and the result is transferred to the flip-flop FF 3 . After this step, the gate G 5 is opened to allow the datum in the flip-flop FF 3 to be delivered to the output relay Y 1 through the output control circuit 3. Thus, the Boolean algebraic equation, X 1 .sup.. X 2 + X 3 .sup.. X 2 = Y 1 , is executed by the sequence instructions at addresses 1 to 5. In the same manner, Boolean algebraic equations expressed by polynomials of AND and OR can be converted into sequence instructions one after another. The sequence instructions are read one after another from the memory of the sequence program storage circuit 4 and executed repeatedly at high speed. Hence the sequence controller shown in FIG. 2 performs functions equivalent to those of the relay sequence shown in FIG. 1. When the relay sequence forms a loop as shown in FIG. 4, this sequence may be expressed in Boolean algebra as follows. Y.sub.1 = X.sub.1 .sup.. X.sub.2 + X.sub.4 .sup.. X.sub.3 .sup.. X.sub.2 + X.sub.4 .sup.. X.sub.5 X.sub.6 + X.sub.1 .sup.. X.sub.3 .sup.. X.sub.5 .sup.. X.sub.6 ( 3) y.sub.2 = x.sub.4 .sup.. x.sub.5 + x.sub.1 .sup.. x.sub.3 .sup.. x.sub.5 + x.sub.1 .sup.. x.sub.2 .sup.. x.sub.6 + x.sub.4 .sup.. x.sub.3 .sup.. x.sub.2 .sup.. x.sub.6 ( 4) because all the loops are to be considered, these Boolean equations are inevitably complicated. If the relay sequence comprises intricate loops, it will become extremely difficult to convert all the logical paths into Boolean equations, and a considerable amount of effort must be made to build a complete sequence program. SUMMARY OF THE INVENTION An object of the invention is to provide an improved sequence controller free of the prior art drawbacks. Another object of the invention is to provide a sequence controller with which a sequence program can readily be constructed. Still another object of the present invention is to provide a sequence controller which is readily adaptable to a variety of sequence control applications. A further object of the invention is to provide a sequence controller which meets the above objects yet is low in cost. Other objects will appear hereinafter. These and other objects are achieved in accordance with the present invention which utilizes a sequence controller of the digital logical circuit type capable of operation in which a necessary sequence instruction is read from the sequence program storage and the sequence is processed by the processing circuit; and which includes a certain definite level set at a branch point in an equivalent sequence circuit according to the path along which the signal of the sequence circuit is transmitted. This level and the on-off state of the branch point are stored in a memory, and given data are processed through the sequence program storage and the memory. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an example of a relay sequence, FIG. 2 is a block diagram showing an example of a conventional sequence controller, FIG. 3 is a block diagram of a processing circuit used with the sequence controller shown in FIG. 2, FIG. 4 is a diagram showing an example of a relay sequence comprising complicated loops, FIG. 5 is a block diagram showing a sequence controller according to the invention, and FIG. 6 is a block diagram showing a processing circuit used with the sequence controller shown in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the invention will be described by referring to FIG. 5. Like constituent elements are indicated by the indentical symbols in FIGS. 2 and 5. In FIG. 5, the numeral 5 denotes a memory which stores the on-off state of a branch relay point i.e., a branch point where an input contact is connected to another input contact or to an output relay contact on a sequence diagram, and which also stores a level corresponding to the number of relay points through which a signal passes so as to turn on one relay point. FIG. 6 shows in block form a processing circuit 2 as in FIG. 5. Like constituent elements are indicated by the identical references in FIGS. 3 and 6. In FIG. 6, LR 1 , LR 2 and LR 3 denote level registers indicating levels at the relay points, COMP 1 denotes a comparator which compares two levels with each other and generates an output of the larger level, COMP 2 denotes a comparator which compares two levels with each other and generates an output of the smaller level, COMP 3 denotes a comparator and adder which compares two levels with each other and generates an output of the smaller level plus 1, and Ga to Ge denote gates of level data. The symbol MAX represents the maximum number of levels which can be stored in the level register LR 3 . The operation of this sequence controller will be described below by referring to the sequence diagram shown in FIG. 4. The relay sequence may be expressed in terms of Boolean algebra as follows. P.sub.1 = X.sub.1 + X.sub.3 .sup.. P.sub.3 + X.sub.2 .sup.. P.sub.2 (5) p.sub.2 = x.sub.2 .sup.. p.sub.1 + x.sub.6 .sup.. p.sub.4 (6) p.sub.3 = x.sub.4 + x.sub.3 .sup.. p.sub.1 + x.sub.5 .sup.. p.sub.4 (7) p.sub.4 = x.sub.5 .sup.. p.sub.3 + x.sub.6 .sup.. p.sub.2 (8) y.sub.1 = p.sub.2 (9) y.sub.2 = p.sub.4 (10) where P 1 , P 2 , P 3 and P 4 represent relay points (branch points) at which input contacts X 1 to X 6 and/or relay contacts Y 1 and Y 2 are connected to each other. The on-off states of the relay points P 1 to P 4 are stored in a memory 5 whereby these relay points may be regarded to be equivalent to the input contacts. Then, assume that the input contact X 1 turns on whereby the relay point P 1 turns on, and the input contact X 3 turns on whereby the relay point P 3 turns on, and then X 1 turns off. Theoretically, under this condition, the relay point P 1 assumes on-state depending on the condition of X 3 P 3 , and the relay point P 3 remains in on-state depending on the condition of X 3 P 1 , as opposed to the practically desired condition where both P 1 and P 3 are in off-state. This makes it impossible to indicate any off-state on a practical relay sequence diagram. To solve this problem, levels are set at the individual relay points P 1 through P 4 , so that one level is higher by 1 than another as a signal proceeds from one relay point to another. By so setting the levels, a relay point where the level is low cannot be turned on from a relay point where the level is high. By this arrangement, the input contact X 1 turns on whereby the relay point P 1 turns on (level 1), and the input contact X 3 turns on whereby the relay point P 3 turns on (level 2). After this step, when the input contact X 1 turns off, the relay point P 1 (level 1) turns off since the condition of X 3 P 3 is level 2. Accordingly, the relay point P 3 turns off. Thus the on and off states correspond to the actual sequence diagram. (Note: The input contacts X 1 , X 2 , . . . always stand at level 0.) To illustrate the invention, the operations of this relay sequence are summarized below in terms of Boolean algebra, Eq. (5), P 1 = X 1 + X 3 .sup.. P 3 + X 2 .sup.. P 2 . __________________________________________________________________________MemorySequenceAddressInstruction Processing__________________________________________________________________________1 LOAD X.sub.1 1 X.sub.1 →FF.sub.1 1 L(X.sub.1) →LR.sub.1 2 FF.sub.1 →FF.sub.2 2 LR.sub.1 →LR.sub.2 3 0→FF.sub.3 3 MAX→LR.sub.32 OR X.sub.3 1 X.sub.3 →FF.sub.1 1 L(X.sub.3)→LR.sub.1 2 FF.sub.2 +FF.sub.3 →FF.sub.3 2 LR.sub.2 →LR.sub.3 only when FF.sub.2 = 1 and LR.sub.2 < LR.sub.3 3 FF.sub.1 →FF.sub.2 3 LR.sub.1 →LR.sub.23 AND P.sub.3 1 P.sub.3 →FF.sub.1 1 L(P.sub.3)→LR.sub.1 2 FF.sub.1.FF.sub.2 →FF.sub.2 2 LR.sub.1 →LR.sub.2 when LR.sub.1 > LR.sub.24 OR X.sub.2 1 X.sub.2 →FF.sub.1 1 L(X.sub.2)→LR.sub.1 2 FF.sub.2 + FF.sub.3 →FF.sub.3 2 LR.sub.2 →LR.sub.3 only when FF.sub.2 = 1 and LR.sub.2 < LR.sub.3 3 FF.sub.1 →FF.sub.2 3 LR.sub.1 →LR.sub.25 AND P.sub.2 1 P.sub.2 →FF.sub.1 1 L(P.sub.2)→LR.sub.1 2 FF.sub.1 .FF.sub.2 →FF.sub.2 2 LR.sub.1 →LR.sub.2 when LR.sub.1 > LR.sub.26 SET P.sub.1 1 FF.sub.2 + FF.sub.3 →FF.sub.3 1 LR.sub.2 →LR.sub.3 only when FF.sub.2 = 1 and LR.sub.2 < LR.sub.32 FF.sub.3 →OUT P.sub.1 2 LR.sub.3 + 1→L(P.sub.1) whenwhen L(P.sub.1) ≧ LR.sub.3 L(P.sub.1) ≧ LR.sub.30→OUT P.sub.1 MAX→L(P.sub.1) whenwhen L(P.sub.1) < LR.sub.3 L(P.sub.1) < LR.sub.3__________________________________________________________________________ (Note: The numerals 1 , 2 , and 3 indicate the timing sequence for the processing, and X.sub.1, X.sub.2, .....always stand at level 0.) When a sequence instruction LOAD X 1 at address 1 is read from a memory in the sequence program part 4, this instruction is decoded, and the state of input contact X 1 is stored in the flip-flop FF 1 . Then the gate G 1 is opened whereby the data in the flip-flop FF 1 is transferred to the flip-flop FF 2 , and the binary code 0 is stored as an initial set in the flip-flop FF 3 . On the other hand, the level 0 of the contact X 1 is registered in the level register LR 1 , and the gate Ga is opened whereby the data in the level register LR 1 is transferred to the level register LR 2 . The level register LR 3 is initially set to a maximum value MAX. Then, when another sequence instruction OR X 3 at address 2 is read from the memory in the sequence program part 4, the state of input contact X 3 is stored in the flip-flop FF 1 , the gate G 4 is opened, and a logic OR combination of flip-flops FF 2 and FF 3 by OR circuit OR is stored in the flip-flop FF 3 . Then the gate G 1 is opened whereby the data in the flip-flop FF 1 is transferred to the flip-flop FF 2 . The level 0 of input contact X 3 is stored in the level register LR 1 . The gate Gd opens only when the flip-flop FF 2 is on (i.e., X 1 is on). If the level of the level register LR 2 is smaller than that of the level register LR 3 , the comparator COMP 2 generates an output of data in the level register LR 2 , which is stored in the level register LR 3 . Then the gate Ga is opened whereby the data in the level register LR 1 is transferred to the level register LR 2 . After this step, another sequence instruction AND P 3 at address 3 is given whereby the state of relay point P 3 is read from the memory 5. This data is stored in the flip-flop FF 1 . Then the gate G 2 is opened whereby a logic AND combination of flip-flops FF 1 and FF 2 by AND circuit is stored in the flip-flop FF 2 . The level of relay point P 3 which is stored in the memory 5 is registered in the level register LR 1 . When the level of the level register LR 1 is larger than that of the level register LR 2 , the comparator COMP 1 generates an output of data in the level register LR 1 , which is stored in the level register LR 2 through the gate Gb. Then, by another sequence instruction OR X 2 at address 4, the state of input contact X 2 is stored in the flip-flop FF 1 . The gate G 4 is opened and an OR logic combination of flip-flops FF 1 and FF 3 by OR circuit is stored in the flip-flop FF 3 . After this step, the gate G 1 is opened whereby the data in the flip-flop FF 1 is transferred to the flip-flop FF 2 . On the other hand, the level 0 of input contact X 2 is registered in the level register LR 1 . When the flip-flop FF 2 is on (i.e., both P 3 and X 3 are on), the gate Gd opens. Thus, if the level of the level register LR 2 is smaller than that of the level register LR 3 , the comparator COMP 2 generates an output of data in the level register LR 2 , which is stored in the level register LR 3 . Then the gate Ga is opened whereby the data in the level register LR 1 is transferred to the level register LR 2 . Next, by another sequence instruction AND P 2 at address 5, the state of the relay point P 2 is read from the memory 5, which is stored in the flip-flop FF 1 . The gate G 2 is opened and a logical AND combination of flip-flops FF 1 and FF 2 by AND circuit is stored in the flip-flop FF 2 . While the level of the relay point P 2 which is stored in the memory 5 is read and registered in the level register LR 1 , the gate Gb is opened and if the level of the level register LR 1 is larger than that of the level register LR 2 , the data in the level register LR 1 is transferred to the level register LR 2 . Then by another sequence instruction SET P 1 at address 6, the gate G 4 opens and a logical OR combination of flip-flops FF 2 and FF 3 by OR circuit is transferred to the flip-flops FF 3 . On the other hand, the gate Gd is opened only when the flip-flop FF 2 is on (i.e., both P 2 and X 2 are on). If the level of the level register LR 2 is smaller than that of the level register LR 3 , the comparator COMP 2 generates an output of data in the level register LR 2 , which is stored in the level register LR 3 . Then the level of the relay point P 1 is read from the memory 5. This level is compared with the level of the level register LR 3 by the comparator COMP 3 . When the level of the relay point P 1 is larger than or equal to that of the level register LR 3 , the gate G 5 is opened whereby the data in the flip-flop FF 3 is stored in the memory 5. When the level of the relay point P 1 is smaller than that of the level register LR 3 , the binary code 0 is stored in the P 1 memory part. Then the level of the relay point P 1 is read from the memory 5. This level is compared with the level of the level register LR 3 by the comparator COMP 3 . When the level of the relay point P 1 is larger than or equal to that of the level register LR 3 , the gate Ge is opened, and 1 is added to the data in the level register LR 3 . The result of data is stored in the P 1 memory part of the memory 5. When the level of the relay point P 1 is smaller than that of the level register LR 3 , the P 1 memory part of the memory 5 is set to a maximum level value MAX. In the above manner, the Boolean algebraic equation, P 1 = X 1 + X 3 .sup.. P 3 + X 2 .sup.. P 2 , is executed by the sequence instructions at addresses 1 to 6. The operation of the relay sequence will further be described in terms of Boolean Eq. (6), P 2 = X 2 .sup.. P 1 + X 6 .sup.. P 4 as summarized below. __________________________________________________________________________MemorySequenceAddressInstruction Processing__________________________________________________________________________7 LOAD X.sub.2 1 X.sub.2 →FF.sub.1 1 L(X.sub.2)→LR.sub.1 2 FF.sub.1 →FF.sub.2 2 LR.sub.1 →LR.sub.2 3 0→FF.sub.3 3 MAX→LR.sub.38 AND P.sub.1 1 P.sub.1 →FF.sub.1 1 L(P.sub.1)→LR.sub.1 2 FF.sub.1.FF.sub.2 →FF.sub.2 2 LR.sub.1 →LR.sub.2 when LR.sub.1 > LR.sub.29 OR X.sub.6 1 X.sub.6 →FF.sub.1 1 L(X.sub.6)→LR.sub.1 2 FF.sub.2 + FF.sub.3 →FF.sub.3 2 LR.sub.2 →LR.sub.3 only when FF.sub.2 = 1, and LR.sub.2 < LR.sub.3 3 FF.sub.1 →FF.sub.2 3 LR.sub.1 →LR.sub.210 AND P.sub.4 1 P.sub.4 →FF.sub.1 1 L(P.sub.4)→LR.sub.1 2 FF.sub.1 .FF.sub.2 →FF.sub.2 2 LR.sub.1 →LR.sub. 2 when LR.sub.1 > LR.sub.211 SET P.sub.2 1 FF.sub.2 + FF.sub.3 →FF.sub.3 1 LR.sub.2 →LR.sub.3 only when FF.sub.2 = 1 and LR.sub.2 < LR.sub.3 2 FF.sub.3 →OUT P.sub.2 2 LR.sub.3 + 1→L(P.sub.2) when when L(P.sub.2) ≧ LR.sub.3 L(P.sub.2) ≧ LR.sub.3 0→OUT P.sub.2 MAX→L(P.sub.2) when when L(P.sub.2) < LR.sub.3 L(P.sub.2) < LR.sub.3__________________________________________________________________________ More specifically, when a sequence instruction LOAD X 2 at address 7 is read from a memory in the sequence program part 4, this instruction is decoded and the state of input contact X 2 is stored in the flip-flop FF 1 . Then the gate G 1 is opened whereby the data in the flip-flop FF 1 is stored in the flip-flop FF 2 , and the binary code 0 is stored in the flip-flop FF 3 . On the other hand, the level 0 of the contact X 2 is registered in the level register LR 1 . When the gate Ga opens, the data in the level register LR 1 is transferred to the level register LR 2 . The level register LR 3 is set to a maximum level value. Then, by another sequence instruction AND P 1 at address 8, the state of the relay point P 1 is read from the memory 5 and stored in the flip-flop FF 1 . The gate G 2 opens and a logical AND combination of flip-flops FF 1 and FF 2 by AND circuit is stored in the flip-flop FF 2 . The level of the relay point P 1 which is stored in the memory 5 is registered in the level register LR 1 . When the level of the level register LR 1 is larger than that of the level register LR 2 , the comparator COMP 1 generates an output of data in the level register LR 1 . Then the gate Gb is opened and this data is stored in the level register LR 2 . After this set, the state of input contact X 6 is stored in the flip-flop FF 1 by another sequence instruction OR X 6 at address 9. Then the gate G 4 is opened and a logical OR combination of flip-flops FF 2 and FF 3 by OR circuit is stored in the flip-flop FF 3 . The gate G 1 is opened whereby the data in the flip-flop FF 1 is transferred to the flip-flop FF 2 . The level 0 of the input contact X 6 is stored in the level register LR 1 . The gate Ga opens only when the flip-flop FF 2 is on. If the level of the level register LR 2 is smaller than that of the level register LR 3 , the comparator COMP 2 generates an output of data in the level register LR 2 , which is transferred to the level register LR 3 . Then the gate Ga is opened and the data in the level register LR 1 is transferred to the level register LR 2 . After this step, the state of the relay point P 4 is read from the memory 5 by another sequence instruction AND P 4 at address 10. This data is stored in the flip-flop FF 1 . Then the gate G 2 is opened and a logical AND combination of flip-flops FF 1 and FF 2 by AND circuit is stored in the flip-flop FF 2 . The level of the relay point P 4 which is stored in the memory 5 is read and stored in the level register LR 1 . The gate Gb is thereby opened, and when the level of the level register LR 1 is larger than that of the level register LR 2 , the data in the level register LR 1 is transferred to the level register LR 2 . The gate G 4 is opened by another sequence instruction SET P 2 at address 11, and a logical OR combination of flip-flops FF 2 and FF 3 by OR circuit is transferred to the flip-flop FF 3 . The gate Gd is opened only when the flip-flop FF 2 is on. When the level of the level register LR 2 is smaller than that of the level register LR 3 , the comparator COMP 2 generates an output of data in the level register LR 2 , which is stored in the level register LR 3 . Then, this level is compared with the level of the relay point P 2 by the comparator COMP 3 . When the level of the relay point P 2 is larger than or equal to that of the level register LR 3 , the gate G 5 opens whereby the data in the flip-flop FF 3 is stored in the P 2 memory part of the memory 5. When the level of the relay point P 2 is smaller than that of the level register LR 3 , the binary code 0 is stored in the P 2 memory part. When the level of the relay point P 2 is larger than or equal to that of the level register LR 3 , the gate Ge opens and 1 is added to the data in the level register LR 3 . The resultant data is stored in the P 2 memory part of the memory 5. When the level of the relay point P 2 is smaller than that of the level register LR 3 , the P 2 memory part of the memory 5 is set to a maximum level value MAX. In the above manner, the Boolean equation, P 2 = X 2 .sup.. P 1 + X 6 .sup.. P 4 , is executed on the sequence instructions at addresses 7 to 11. In the same manner as above, Boolean Eqs. (7) to (10) can be converted respectively into sequence programs. Because this sequence program is executed repeatedly at high speed, the sequence controller shown in FIG. 5 performs functions equivalent to those of the relay sequence shown in FIG. 4. According to the invention, as has been described above, the branch points where input contacts and/or relay contacts on a sequence diagram are connected to each other are used as relay points. The on and off states of these relay points and the levels corresponding to the number of relay points by way of which one relay point is turned on are stored in a memory and a given data is processed according to the level. Accordingly, the sequence program can be set up exactly according to Boolean algebraic equations using relay points. Because these Boolean equations can be easily derived, this sequence controller can provide a sequence program quickly and accurately. In other words, the sequence controller of this invention can readily be adapted to a wide variety of sequence control applications. While one preferred embodiment of the invention has been described and illustrated in detail, it is to be clearly understood that this should not be construed as necessarily limiting the scope of the invention, since it is apparent that many changes can be made to the disclosed principles by those skilled in the art in order to suit particular applications.

A sequence controller of the digital logical circuit type, comprising a sequence program part and a processing circuit, wherein the desired sequence instruction is read from the sequence program part, and the sequence is processed and controlled by the processing circuit. A certain definite level is set at a branch point in an equivalent sequential circuit according to the path along which a signal of the sequential circuit is transmitted. This level and the on-off state of the branch point are stored in a memory. The given data are processed and controlled through the sequence program part and the memory.

BACKGROUND OF THE INVENTION The present invention relates to the arts of nuclear medicine and diagnostic imaging. It finds particular application in conjunction with gamma cameras and will be described with particular reference thereto. It is to be appreciated that the present invention is applicable to single photon emission computed tomography (SPECT), positron emission tomography (PET), whole body nuclear scans, and/or other like applications. Diagnostic nuclear imaging is used to study a radionuclide distribution in a subject. Typically, one or more radiopharmaceuticals or radioisotopes are injected into a subject. The radiopharmaceuticals are commonly injected into the subject's blood stream for imaging the circulatory system or for imaging specific organs which absorb the injected radiopharmaceuticals. Gamma or scintillation camera detector heads, typically including collimators, are placed adjacent to a surface of the subject to monitor and record emitted radiation. For three-dimensional reconstruction, the detector heads are rotated or indexed around the subject to monitor the emitted radiation from a plurality of directions. In SPECT, emission radiation is detected by each collimated detector. In PET, data collection is limited to emission radiation that is detected concurrently by a pair of oppositely disposed heads. The monitored radiation data from the multiplicity of directions is reconstructed into a three dimensional image representation of the radiopharmaceutical distribution within the subject. One of the problems with these imaging techniques is that photon absorption and scatter by portions of the subject or subject support between the emitting radionuclide and the detector heads distort the resultant image. One solution for compensating for photon attenuation is to assume uniform photon attenuation throughout the subject. That is, the subject is assumed to be completely homogeneous in terms of radiation attenuation with no distinction made for bone, soft tissue, lung, etc. This enables attenuation estimates to be made based on the surface contour of the subject. However, human subjects do not cause uniform radiation attenuation, especially in the chest. In order to obtain more accurate SPECT and PET radiation attenuation measurements, a direct transmission radiation attenuation measurement is made using transmission computed tomography techniques. More specifically, radiation is projected from a radiation source through the subject. Attenuated radiation rays are received by the detector at the opposite side. The source and detectors are rotated to collect transmission data concurrently or sequentially with the emission data through a multiplicity of angles. This transmission data is reconstructed into an image representation using conventional tomography algorithms. Regional radiation attenuation properties of the subject and the support, which are derived from the transmission computed tomography image, are used to correct or compensate for radiation attenuation in the emission data. SPECT and PET measurements are typically made at incrementally stepped locations. One difficulty resides in optimizing the sampling of both the SPECT or PET emission data and the transmission data so as to reduce overall scan time. Typically, nuclear camera detector heads are stepped to a plurality of positions around the patient, e.g. 60 positions. At each position, emission and/or transmission radiation data is collected. The total time to perform a transmission scan is composed of the time to actually acquire data at each angular orientation and the time to mechanically rotate the gantry from one angular orientation to another and stabilize it at the new orientation. Typically, these two components are of a similar order of magnitude, e.g. 4-5 seconds for data collection at each angular orientation and approximately 2-4 seconds for gantry rotation to each angular orientation and stabilization. A wait time for stabilization of only 2-4 seconds per step adds 4-8 minutes to a 120 step scan. The present invention contemplates a new and improved data sampling technique for collecting transmission radiation which overcomes the above-referenced problems and others. SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, a method of diagnostic imaging using a nuclear medicine gamma camera includes placing a subject in a subject receiving aperture and injecting the subject with a radiopharmaceutical. At least one radiation source and a plurality of radiation detectors are positioned about the subject receiving aperture such that the radiation source is across the subject receiving aperture from a corresponding radiation detector. Radiation from the radiation source is transmitted toward the corresponding radiation detector which is positioned across the subject receiving aperture. The at least one radiation source and radiation detectors are continuously rotated together about the subject receiving aperture. Radiation transmitted by the radiation source is detected using one of the plurality of radiation detectors and reconstructed into an attenuation volume image representation. Radiation emitted by the injected radiopharmaceutical is detected using the plurality of radiation detectors and reconstructed into an image representation. In accordance with another aspect of the present invention, a nuclear medicine gamma camera for diagnostic imaging includes a rotating gantry which defines a subject receiving aperture. A plurality of radiation detectors are movably attached to the rotating gantry such that the detector heads rotate about the subject receiving aperture with rotation of the rotating gantry about an axis of rotation. At least one radiation source is mounted to at least one detector head for rotation therewith such that transmission radiation from the radiation source is directed toward and received by a corresponding detector head positioned across the subject receiving aperture from the radiation source. The radiation source is rastered back and forth in a direction parallel to that of the axis of rotation. A raster sensor detects rastering of the radiation source across a field of view and a gantry sensor detects gantry rotation about the subject receiving aperture. A reconstruction processor reconstructs a volumetric emission image representation from the detected emission and transmission data, the sensed rastering of the radiation source, and the sensed gantry rotation. In accordance with another aspect of the present invention, a method of generating emission radiation images includes concurrently (1) continuously rotating a radiation source around an axis of rotation and (2) rastering a radiation source back and forth parallel to the axis of rotation. Radiation transmitted from the radiation source and radiation emitted by radioisotopes disposed in a volume of interest adjacent the axis of rotation are detected in at least one detection plane which is parallel to and displaced from the axis of rotation. The at least one detection plane is rotated concurrently with the radiation source. The rastering of the radiation source is sensed as the transmitted radiation is detected and the rotation of the radiation source and the at least one detection plane are sensed as the transmitted and emitted radiation are detected. The detected transmission radiation is reconstructed into a transmission volume image representation. Detected emission radiation is weighted with the transmission image representation and the weighted emission radiation is then reconstructed into a volumetric emission radiation image representation. One advantage of the present invention is that it reduces gantry dead time. Another advantage of the present invention is that it reduces overall transmission scan time by approximately 50%. Another advantage of the present invention is that it provides greater resolution for SPECT emission data than is required for transmission data. Other benefits and advantages of the present invention will become apparent to those skilled in the art upon a reading and understanding of the preferred embodiment. BRIEF DESCRIPTION OF THE DRAWINGS The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the invention. FIG. 1 is a diagrammatic illustration of a nuclear medicine gamma camera in accordance with aspects of the present invention; FIG. 2 is a diagrammatic illustration of a preferred orientation of heads in a three head nuclear medicine gamma camera for SPECT imaging in accordance with the present invention; FIG. 3 is a perspective view of a preferred orientation of two heads of a nuclear medicine gamma camera for SPECT or PET in accordance with the present invention; FIG. 4 is a plot of gantry angle versus radiation source position in accordance with a step-and-shoot sampling technique of the prior art; and, FIG. 5 is a plot of gantry angle versus radiation source position in accordance with the continuous rotation sampling technique of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, a diagnostic imaging apparatus includes a subject support 10 , such as a table or couch, which supports a subject 12 being examined or imaged. The subject 12 is injected with one or more radiopharmaceuticals or radioisotopes such that emission radiation is emitted therefrom. Optionally, the subject support 10 is selectively height adjustable so as to center the subject 12 at a desired height, e.g., the volume of interest is centered. A first or stationary gantry 14 rotatably supports a rotating gantry 16 . The rotating gantry 16 defines a subject receiving aperture 18 . In a preferred embodiment, the first gantry 14 is moved longitudinally along the subject support 10 so as to selectively position regions of interest of the subject 12 within the subject receiving aperture 18 . Alternately, the subject support 10 is advanced and retracted to achieve the desired positioning of the subject 12 within the subject receiving aperture 18 . Detector heads 20 a , 20 b , 20 c are individually positionable on the rotating gantry 16 . The detector heads 20 a - 20 c also rotate as a group about the subject receiving aperture 18 (and the subject 12 when received) with the rotation of the rotating gantry 16 . The detector heads 20 a - 20 c are radially and circumferentially adjustable to vary their distance from the subject and spacing on the rotating gantry 16 , as for example, in the manner disclosed in U.S. Pat. No. 5,717,212. Separate translation devices 22 a , 22 b , 22 c , such as motors and drive assemblies, independently translate the detector heads radially and laterally in directions tangential to the subject receiving aperture 18 along linear tracks or other appropriate guides. Each of the detector heads 20 a - 20 c has a radiation receiving face facing the subject receiving aperture 18 . Each head includes a scintillation crystal, such as a large doped sodium iodide crystal, that emits a flash of light or photons in response to incident radiation. An array of photomultiplier tubes receive the light flashes and convert them into electrical signals. A resolver circuit resolves the x, y-coordinates of each flash of light and the energy of the incident radiation. That is to say, radiation strikes the scintillation crystal causing the scintillation crystal to scintillate, i.e., emit light photons in response to the radiation. The photons are received by the photomultiplier tubes and the relative outputs of the photomultiplier tubes are processed and corrected to generate an output signal indicative of (i) a position coordinate on the detector head at which each radiation event is received, and (ii) an energy of each event. The energy is used to differentiate between various types of radiation such as multiple emission radiation sources, stray and secondary emission radiation, scattered radiation, transmission radiation, and to eliminate noise. In SPECT imaging, a projection image representation is defined by the radiation data received at each coordinate on the detector head. In PET imaging, the detector head outputs are monitored for coincident radiation. From the position and orientation of the heads and the location on the faces at which the coincident radiation was received, a ray between the peak detection points is calculated. This ray defines a line along which the radiation event occurred. The radiation data from a multiplicity of angular orientations of the heads is then reconstructed into a volumetric image representation of the region of interest. For SPECT imaging, the detector heads 20 a - 20 c include mechanical collimators 24 a , 24 b , 24 c , respectively, removably mounted on the radiation receiving faces of the detector heads 20 a - 20 c . The collimators include an array or grid of lead vanes which restrict the detector heads 20 a - 20 c from receiving radiation not traveling along selected rays in accordance with the selected imaging procedure. For PET imaging, a SPECT camera without collimators on the detector heads may be employed. Alternately, PET imaging is performed using collimators to eliminate stray radiation. With reference to FIG. 2 and FIG. 3 and continuing reference to FIG. 1, at least one radiation source 30 a is mounted to at least one detector head 20 a such that transmission radiation (represented by the arrows 32 a ) from the radiation source 30 a is directed toward and received by the corresponding detector head 20 b positioned across the subject receiving aperture from the radiation source 30 a . It is to be appreciated that radiation sources may be mounted to two or all three detector heads. In a preferred embodiment, a collimator is employed at least on the detector head 20 b which receives the transmission radiation 32 a . That is to say, the collimator 24 b restricts the detector head 20 b , (in the embodiment of FIG. 2) from receiving those portions of transmission radiation not traveling along direct rays from the source to the radiation receiving face of the detector head. Alternately, other collimation geometries are employed for different applications and radiation sources, such as a line source. Additional collimation may take place at the source. FIG. 2 illustrates a three-head embodiment, including a first detector head 20 a , a second detector head 20 b , and a third detector head 20 c arranged on the rotating gantry 16 spaced from one another around the subject receiving aperture 18 . A first radiation source 30 a is mounted to the first detector head 20 a such that transmission radiation 32 a therefrom is directed toward and received by the second detector head 20 b . A second radiation source 30 b is optionally mounted to the second detector head 20 b such that transmission radiation therefrom can be directed toward and received by the first detector head 20 a. In one embodiment, the radiation source 30 a contains a radioactive point source 36 a adjustably mounted inside a shielded steel cylinder which is sealed at the ends. As shown in FIG. 3, the radiation source 30 a rasters longitudinally across the field of view as the gantry rotates through a plurality of angular orientations about the subject receiving aperture. The steel cylinder is adjustably mounted onto the corresponding detector head through a pivoting arm mechanism. Alternately, the radiation source 30 a is a bar source, flat rectangular source, disk source, flood source, tube or vessel filled with radionuclides, or active radiation generators such as x-ray tubes. With reference again to FIG. 1, as the gantry 16 continuously rotates about the subject receiving aperture 18 during the collection of transmission data, a gantry rotation sensor 52 senses or indexes the gantry rotation, and therefore the location of the detector heads 20 a - 20 c and the radiation source 30 a at each data sampling. In one embodiment, the gantry rotation sensor is an optical sensor which senses the position of the gantry versus time by projecting light, such as a laser beam, through a graticulated ring on the gantry and receiving the projected light. It is to be appreciated that conventional mechanical means, such as rotating gears, are also employed for detecting angular orientation of the gantry. A raster sensor 56 senses or indexes the location or speed of the point source 36 a within the radiation source 30 a as it continuously rasters back and forth across the field of view during the continuous rotation of the gantry 16 . As will be described more fully below, data from the gantry sensor 52 and the raster sensor 56 are used to reconstruct the transmission data from the gantry sensor 56 and detector head. Radial and any circumferential offset information are used to reconstruct the emission data. Running an imaging operation includes a reconstruction process for emission and transmission data. The reconstruction process changes according to the type of radiation collected and the types of collimators used (i.e., fan, cone, parallel beam, and/or other modes). Emission radiation from the subject 12 is received by detector heads 20 a - 20 c and transmission radiation 32 a from the radiation source 30 a is received by the detector head 20 b to generate emission projection data and transmission projection data. The emission data normally contains inaccuracies caused by varying absorption characteristics of the subject's anatomy. A sorter 60 sorts the emission projection data and transmission projection data, such as on the basis of their relative energies or the detector head which originated the data. The data is stored in a projection view memory 62 , more specifically in a corresponding emission data memory 62 e and transmission data memory 62 t . A reconstruction processor 64 t uses a fan beam reconstruction algorithm to reconstruct the transmission data into a transmission image representation or volume of attenuation factors stored in a memory 66 . Each voxel value stored in the memory 66 is indicative of attenuation of tissue in a corresponding location within the subject 12 . An emission data correction processor 68 corrects each emission data in accordance with the attenuation factors determined from the transmission data. More specifically, for each ray along which emission data is received, the emission correction processor 68 calculates a corresponding ray through the transmission attenuation factors stored in the memory 66 . Each ray of the emission data is then weighted or corrected by the emission data correction processor 68 in accordance with the attenuation factors. The corrected emission data are reconstructed by an emission radiation reconstruction processor 70 to generate a three-dimensional emission image representation that is stored in a volumetric emission image memory 72 . A video processor 74 withdraws selected portions of the data from the image memory 72 to generate corresponding human-readable displays on a video monitor 76 . Typical displays include reprojections, selected slices or planes, surface renderings, and the like. With reference to FIG. 4 and FIG. 5 and continuing reference to FIG. 1, a continuous rotation sampling scheme is utilized to acquire transmission data. As illustrated in FIG. 5, during a transmission scan, the point source continuously rasters back and forth across the field of view (from P a to P b and vice versa) while the gantry continuously rotates through a plurality of angular orientations to acquire transmission data. For example, rather than rotating and stabilizing the gantry at a 0° orientation, then rastering the point source from P a 1 to P b 1 , and then rotating the gantry to a 6° angular orientation (as illustrated in prior art FIG. 4 ), the gantry rotates continuously from 0° through 6° while the radiation point source rasters from P a 1 to P b 1,2 . Collecting transmission data during continuous rotation of the gantry facilitates sequential collection of a complete set of emission and transmission data in a greatly reduced time (as opposed to the step-and-shoot prior art method illustrated in FIG. 4 ). Those skilled in the art will appreciate that continuous rotation and translation of the point source causes the apex of the transmission radiation fans to traverse a twisted path. In other words, each transmission projection is no longer a common horizontal line on a plot of gantry angle versus radiation source position and P b 1 and P b 2 completely overlap, illustrated as P b 1,2 in FIG. 5 . In this embodiment, the transmission data is handled as a series of slices, each slice being defined by a plurality of radiation fans with known apices, each offset by a small angle from the preceding slice. In order to account for the continuous rotation of the gantry during transmission data acquisition, the transmission reconstruction processor 64 t uses a fan beam reconstruction algorithm which is indexed for the actual apex position of each sampled data line. It is to be appreciated that other conventional reconstruction algorithms may be employed. Proper indexing of the continuously changing camera geometry includes calculating an angular displacement versus radiation source motion index. This index relates the rate of gantry rotation to the rastering speed of the point source for any given element of a transmission projection. The gantry rotation sensor 52 senses the angular position of the gantry, and therefore the point source about the subject receiving aperture, while the raster speed sensor 56 senses the rastering position or speed of the point source. A simple division of gantry rotation speed (degree/second) by point source rastering speed (cm/second) can supply an angular displacement versus radiation source motion index (degree/cm) for use in the reconstruction algorithm. Preferably, the motion index is converted into units of gantry rotation (in degrees) per unit of radiation source motion (in terms of a radiation detector face pixel). Therefore, the transmission reconstruction processor 64 t updates the geometry of the gamma camera on a pixel-by-pixel basis. The effective resolution of the emission data is selected with the rotational speed of the rotating gantry. In the embodiment of FIG. 5, the effective transmission data resolution in the center plane is 6° and at the edge planes is 12°. However, the more significant portions of the image are normally near the center. In another embodiment, two radiation sources are employed for transmission scanning with the angular sampling of the first source/detector combination overlapping the angular sampling of the second source/detector combination. In this embodiment, the apex of the transmission radiation fan from the first source/detector combination is forced between the apex from the second source/detector combination such that the transmission data resolution is 6° at the edge planes, as in the center plane, resulting in better overall angular sampling. The resolution of the transmission data is adjustable by selecting the point source speed relative to the gantry rotation speed. The point source of radiation is preferably slow enough that a statistically meaningful amount of radiation is sampled in each plane, but fast enough that radiation fan apex orientation blurring is minimized. The invention has been described with reference to the preferred embodiment. Modifications and alterations will occur to others upon a reading and understanding of the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

A continuous rotation sampling scheme for use with a nuclear medicine gamma camera facilitates collection of transmission and emission data leading to a reduced overall scan time. The gantry ( 16 ) contains a plurality of radiation detector heads ( 20 a -20 c ) with planar faces and at least one adjustably mounted radiation source ( 30 a ). During transmission data collection, the gantry ( 16 ) continuously rotates about a subject receiving aperture ( 18 ) while the radiation source ( 30 a ) continuously rasters back and forth across the field of view. The detected transmission radiation ( 32 a ) is reconstructed into an attenuation volumetric image representation by a transmission reconstruction processor ( 64 t ). The transmission reconstruction processor ( 64 t ) performs a fan beam reconstruction algorithm in each of a multiplicity of planes perpendicular to an axis of rotation. An angular displacement versus radiation source motion index is calculated in order to update the transmission reconstruction for a sampled data line of transmission radiation. Such continuous rotation during transmission data acquisition reduces overall scan time by eliminating the dead time during which the gantry rotates and comes to rest at incremental angular orientations.

[0001] This is a continuation of application Ser. No. 10/896,612 filed Jul. 20, 2004, still pending, which was a continuation of application Ser. No. 10/271,117 filed Oct. 15, 2002, now U.S. Pat. No. 6,765,000, which was a continuation of application Ser. No. 09/510,704, filed Feb. 22, 2000, now U.S. Pat. No. 6,465,473, which was a continuation-in-part of application Ser. No. 09/270,962, filed Mar. 17, 1999, now U.S. Pat. No. 6,087,382. BACKGROUND OF THE INVENTION [0002] This invention relates to an improved method for treatment of symptoms associated in humans with reactive arthritis or idiopathic bursitis. [0003] Reactive arthritis refers to a spondyloarthritity which usually arises as a complication of an infection elsewhere in the body. Reactive arthritis can be caused by species of Shigella bacteria (most notably Shigella flexneri ), Yersinia enterocolitica, Campylobacter jejuni, several species of Salmonella, genitourinary pathogens, Chlamydia trachomatis, Neisseria gonorrhea, Ureaplasma urealyticum, Streptococcus pyogenes, and other yet unidentified infectious agents. [0004] Reactive arthritis commonly occurs in young men and women, but can occur at any age. Sufferers experience joint pain, stiffness, redness or swelling. Common symptoms may include fatigue, malaise, fever, and weight loss. The joints of the lower extremities, including the knee, ankle, and joints of the foot, are the most common sites of involvement, but symptoms can also occur in the wrists, fingers, elbows, shoulders, neck, and lower back. Other symptoms may include urethritis and prostatitis in males, and cervicitis or salpingitis in females. Ocular disease is common ranging from transient, asymptomatic conjunctivitis to aggressive anterior uveitis that occasionally results in blindness. Mucocutaneous lesions and nail changes are frequent. On less frequent or rare occasions manifestations of reactive arthritis include cardiac conduction defects, aortic insufficiency, central or peripheral nervous system lesions, and pleuropulmonary infiltrates. [0005] Treatment of patients suffering from reactive arthritis with nonsteroidal anti-inflammatory drugs (“NSAIDs”) provides some benefit, although symptoms of reactive arthritis are rarely completely alleviated and some patients fail to respond at all. The preferred initial treatment of choice for acute reactive arthritis is indomethacin in divided doses of 75 to 150 milligrams per day. The NSAID of last resort is phenylbutazone, in doses of 100 milligrams twice or three times per day, because of its potentially serious side effects. Patients with debilitating symptoms refractory to NSAID therapy may be treated with cytotoxic agents such as azathioprine or methotrexate, or with sulfasalazine. Tendinitis, other lesions, and uveitis may benefit from corticosteroids. Minocycline hydrochloride, a semisynthetic derivative of tetracycline, is indicated for infections caused by at least Shigella microorganisms, Streptococcus pyogenes, and Neisserie gonorrhoeae. It is therefore an accepted treatment in incidents of reactive arthritis triggered by these biological entities. [0006] Long-term follow-up studies have suggested that some joint symptoms persist in many, if not most, patients with reactive arthritis. Recurrences of the more acute symptoms are common and as many as twenty-five percent of patients either become unable to work or are forced to change occupations because of persistent joint problems. [0007] Bursitis is inflammation of a bursa, a thin-walled sac lined with synovial tissue. The function of the bursa is to facilitate movement of tendons and muscles over bony prominences. Bursitis may be caused by excessive frictional forces, trauma, systemic disease such as rheumatoid arthritis or gout, or infection. The most common form of bursitis is subacromial. Trochanteric bursitis causes patients to experience pain over the lateral aspect of the hip and upper thigh, and tenderness over the posterior aspect of the greater trochanter. Retrocalcaneal bursitis involves the bursa located between the calcaneus and the posterior surface of the Achilles tendon. Pain is experienced at the back of the heel, and swelling appears on either or both of the medial and lateral sides of the tendon. Retrocalcaneal bursitis occurs in association with spondyloarthritities, rheumatoid arthritis, gout, and trauma. [0008] Treatment of bursitis generally consists of prevention of the aggravating condition, rest of the involved part, an NSAID, and local steroid injection. In the long term, bursitis can result in loss of use of a joint and chronic pain syndrome. [0009] The long term effects of reactive arthritis and bursitis range from chronic pain to crippling disability. It is also thought that many instances of osteoarthritis and psoriatic arthritis are in actuality reactive arthritis. Unfortunately, current procedures for management treat the symptoms of these diseases rather than their underlying pathogens. SUMMARY OF THE INVENTION [0010] Significant benefits can be obtained by treating humans affected with conditions associated with reactive arthritis or bursitis using combinations of acyclovir, minocycline hydrochloride, and metronidazole or, alternatively, valacyclovir hydrochloride, minocycline hydrochloride, and metronidazole. [0011] Acyclovir is an anti-viral drug. The chemical name of acyclovir is 2-amino-1,9-dihydro-9-[(2-hydroxyethoxy)methyl]-6H-purin-6-one. Acyclovir is commercially available under the brand name ZOVIRAX® in capsules, tablets, or suspension. Acyclovir has demonstrated anti-viral activity against herpes simplex virus types I and II, varicella-zoster virus, Epstein-Barr virus and cytomegalovirus, both in vitro and in vivo. [0012] Valacyclovir hydrochloride (sold under the brand name Valtrex®) is the hydrochloride salt of L-valyl ester of acyclovir. The chemical name of valacyclovir hydrochloride is L-valine 2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)methoxy]ethyl ester, monohydrochloride. Valacyclovir hydrochloride is rapidly and nearly completely converted to acyclovir in the body. [0013] Acyclovir and valacyclovir hydrochloride are members of the family of synthetic purine nucleoside analog antiviral drugs. [0014] Minocycline hydrochloride is a bacteriostatic antibiotic which exerts its antimicrobial effect by inhibition of bacterial protein synthesis. It has been shown to be effective against gram-negative bacteria, some gram-positive bacteria and other microorganisms. Minocycline hydrochloride is a member of the tetracycline family. [0015] Metronidazole is an oral synthetic antiprotozoal and antibacterial agent. Heretofore it has been indicated for treatment of symptomatic trichomoniasis, intestinal amebiasis, and a wide range of intra-abdominal, skin, gynecological, bone and joint, lower respiratory tract and central nervous system infections, bacterial septicemia and endocarditis. Metronidazole is a member of the nitroimidazole family. [0016] Ciprofloxacin is a member of the quinolone family of antimicrobial agents. It is a bacteriacidal antibiotic, in the class of antibiotics called fluoroquinolones, which acts to interfere with DNA gyrase, an enzyme needed for the synthesis of bacterial DNA. Quinolones are widely considered to be a medically acceptable alternative to tetracyclines. [0017] One embodiment of a combination for treatment of the symptoms in human beings of reactive arthritis or idiopathic bursitis, or both, comprises the combination of acyclovir, minocycline hydrochloride, and metronidazole. An alternative combination comprises the substitution of valacyclovir hydrochloride in place of acyclovir. The pharmaceutical dosages of the compounds of the combination may be administered in capsules, tablets, in suspension form, or by injection. [0018] The invention provides a method for administration of a pharmaceutical combination that puts the diseases of reactive arthritis and bursitis into remission. Treatment with the combination may effect a cure of reactive arthritis and bursitis, but definitive testing has not been performed to confirm that fact. [0019] It is therefore a primary object of the invention to provide a method for administration of a combination for treating conditions in human beings associated with either or both reactive arthritis or idiopathic bursitis. [0020] Another object of the invention is to provide a method for administration of a treatment for conditions in human beings associated with either or both reactive arthritis or idiopathic bursitis that puts the disease being treated into fill remission. [0021] A further object of the invention is to provide a method for administration of a treatment for any constellation of symptoms amenable to treatment using the above combination, including for example, cases of reactive arthritis which have been misdiagnosed as osteoarthritis or psoriatic arthritis. DETAILED DESCRIPTION OF THE INVENTION [0022] U.S. Pat. No. 6,087,382 to Bonner, Jr., et al., describes a method of treatment involving administration of a combination of L-lysine, minocycline hydrochloride, and metronidazole. An alternate method includes administration of InH for those individuals who have tested positively for mycobacterial exposure, along with the underlying combination of L-lysine, minocycline hydrochloride, and metronidazole. Another method described in U.S. Pat. No. 6,465,473 to Bonner, Jr., et al., includes administration of valacyclovir hydrochloride with the underlying combination of L-lysine, minocycline hydrochloride, and metronidazole. A third method of treatment, described in applicants' U.S. Pat. No. 6,197,776, includes administration of acyclovir with the underlying combination of L-lysine, minocycline hydrochloride, and metronidazole. An embodiment of the treatment, described in applicants' U.S. Pat. No. 6,765,000, comprises a pharmaceutical combination including acyclovir, minocycline hydrochloride, and metronidazole. Alternatively, the treatment may include valacyclovir hydrochloride, minocycline hydrochloride, and metronidazole. Either of these embodiments may be supplemented with administration of pyridoxine hydrochloride, glucosamine, manganese, vitamin C, and desalinated seawater, such as Essence of Life. [0023] Administration will generally be accomplished orally via capsules, tablets, or in suspension form, but delivery could be accomplished by injection, or any other method commonly used for administration of internal medicines. [0024] Like L-lysine, acyclovir inhibits herpes simplex viruses, but by a different mechanism. While L-lysine tends to stop the virus from replicating by inhibiting the initiation of the replication process, acyclovir inhibits effective replication of actively replicating viral particles, e.g., by stopping replication of herpes viral DNA. This is accomplished by either competitive inhibition or inactivation of viral DNA polymerase or incorporation and termination of the growing viral DNA chain. It is believed that acyclovir results in a substantial benefit due to its inhibition of virus replication. In double-blind testing, it has been found that the administration of the combination of acyclovir, minocycline hydrochloride, and metronidazole is an effective treatment for reactive arthritis or bursitis. Acyclovir has never been used in the prior art for treatment of arthritis or bursitis. It does not appear to be effective alone for the treatment of these diseases. The preferred dose of acyclovir is 400 mg twice daily. The daily dose of acyclovir may vary from 200 mg to 4 grams. [0025] The preferred dose of valacyclovir hydrochloride is 500 mg twice daily. The total daily dose of valacyclovir hydrochloride may vary from 125 mg to 4 grams. [0026] The preferred dose of minocycline hydrochloride is an initial dosage of 200 mg followed by doses of 100 mg twice per day. Daily doses of minocycline hydrochloride following the initial administration of 200 mg may vary from 50 mg to 200 mg. Based upon their similar properties, it is expected that other members of the tetracycline family such as doxycycline can be effectively substituted, in the combination, for minocycline hydrochloride. [0027] The preferred dose of metronidazole is 250-500 mg twice per day. The total dose per day of metronidazole may vary from 100 mg to 1,000 mg. [0028] It is known that the combination of minocycline hydrochloride, InH, and metronidazole inhibits the multiplication of susceptible organisms, including shigella, salmonella, chlamydia, streptococci, and mycobacteria. Applicants have also determined that the combination of L-lysine, minocycline hydrochloride, and metronidazole provides a medically effective treatment for reactive arthritis and bursitis. See U.S. Pat. No. 6,087,382. It has also been shown that the combination of acyclovir, L-lysine, minocycline hydrochloride, and metronidazole provides an effective treatment for these conditions. See U.S. Pat. No. 6,197,776. Individuals with severe symptoms, including joint swelling and joint contractures, who were not thought to be candidates for treatment using the combination of L-lysine, minocycline hydrochloride, and metronidazole only, have also experienced substantial beneficial effects in response to treatment with that combination and valacyclovir hydrochloride. [0029] The preferred embodiment of the present invention comprises the combination of acyclovir, or its prodrug valacyclovir hydrochloride, with minocycline hydrochloride and metronidazole. An alternate embodiment comprises valacyclovir hydrochloride with minocycline hydrochloride and metronidazole. These combinations each provide a medically effective treatment for reactive arthritis and bursitis. The total combination of medicines in each of these embodiments presents a broad spectrum approach that it is believed effectively addresses the underlying pathogenesis for reactive arthritis and what has previously been referred to as idiopathic bursitis, and further is a beneficial treatment for reactive arthritis in particular cases wherein the symptom complex has been misdiagnosed as osteoarthritis or psoriatic arthritis, or in any other similar cases of misdiagnosis. EXAMPLE [0030] The following examples serve to illustrate the invention, but is not meant to restrict its effective scope. Example 1 [0031] A 77 year old female presented with complaints of neck, upper back, lower back, bilateral shoulder, bilateral wrist, digits of hands, bilateral hip, and bilateral ankle pains of years duration. The patient complained of associated stiffness in those same joints. Her physical examination was remarkable for tenderness at her neck, right shoulder, elbow bilaterally, wrist bilaterally, the metacarpal phalangeal and the proximal interphalangeal joints of her right hand, hip bilaterally, knee bilaterally, and the Achilles insertion area bilaterally. The Sed rate and rheumatoid factors were normal. This patient was diagnosed with reactive arthritis and was started on a treatment consisting of 125 mg of metronidazole, 250 mg of valacyclovir hydrochloride, and 50 mg of minocycline hydrochloride twice daily. After 69 days of such treatment, the patient noted pain in the palm of her left hand only. She further denied any stiffness. Physical examination on the 69 th day did not reveal any tenderness. Thus, treatment effected resolution of pain, stiffness, and tenderness in this patient. Example 2 [0032] A 52 year old male presented with complaints of bilateral knee and left wrist pain. He also noted associated morning stiffness. He was treated with minocyline hydrochloride 100 mg BID and acyclovir 400 mg BID. This resulted in significan improvement, but not total resolution of his complaints of pain and stiffness in his knees and left wrist. [0033] There have been thus described certain preferred embodiments of a pharmaceutical formulation for treatment of conditions in human beings associated with either or both reactive arthritis or idiopathic bursitis. While preferred embodiments have been described and disclosed, it will be recognized by those with skill in the art that modifications are within the true scope and spirit of the invention. The appended claims are intended to cover all such modifications.

A method for treatment for conditions in human beings associated with either or both reactive arthritis or bursitis comprising administering a combination of member of the family of synthetic purine nucleoside analog antiviral drugs, a member of the tetracycline family, and a member of the nitroimidazole family, or alternatively, administering a combination of a member of the family of synthetic purine nucleoside analog antiviral drugs, a member of the quinolone family, and a member of the nitroimidazole family.

BACKGROUND OF THE INVENTION The present invention relates to hand trucks for tilting and moving table-like objects which are supported by detachable or retractable legs. More specifically, the invention relates to hand trucks for moving grand pianos. The moving of a large, heavy, fragile objects has long been recognized as a difficult task. For example, most grand pianos are equipped with legs which are relatively weak considering the amount of weight which they support. These legs are easily broken so it is common practice to lift a grand piano off its legs and onto a dolley whenever the piano is moved even a short distance. When moving a grand piano past obstructions or through door openings, it is usually necessary to set the instrument on its side and remove its legs. This activity has traditionally required the labor of two or more workers and a substantial amount of time. SUMMARY OF THE INVENTION The present invention is a hand truck which may be used to move grand pianos or similarly shaped objects. The truck comprises an elongated support frame which conforms to the underside of a grand piano bed and an A-frame jacking carriage pivotally supporting said carriage and operable to lift said carriage and a piano supported thereon off of the ground. Also provided is a transport base onto which the piano may be tilted. The base is supported by casters so that the piano may conveniently be moved from place to place while resting thereon. It is a primary object of this invention to provide a device which will enable one worker of ordinary strength to lift a grand piano or similarly shaped article off the ground and tilt it onto its side for transport. A further object is to provide such a device which is simple, lightweight and has a minimum of moving parts. Other objects and features of the invention will be apparent from the attached drawings and specification. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a side elevation showing the elongated frame, transport base and jacking mechanism of a first embodiment of a piano truck according to the present invention; FIG. 2 is a top view of the elongated frame and transport base of the truck of FIG. 1; FIG. 3 is an end view of a support block mounted on the elongated frame of FIG. 2; FIG. 4 is a side view of the block of FIG. 3; FIG. 5 is an end view of the jacking mechanism of the truck of FIG. 1; FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. 5; FIG. 7 is an oblique view of the transport base of the truck of FIG. 1; FIG. 8 is an oblique view of a second embodiment of a piano truck according to the present invention; and FIG. 9 is a side view of the truck shown in FIG. 8. DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, the piano truck of the present invention includes three major components, an elongated support frame 20, an A-frame jacking carriage 22 and a transport base or dolley 24. Referring specifically to FIGS. 1 and 2 the support frame 20 includes a pair of longitudinal rails 30 and a plurality of lateral cross brace rails 32. Perpendicular to the longitudinal rails 30 at one end of the frame 20 is mounted a foot plate 36 which meets the elongated frame to form a corner at 38. The side of the foot plate which faces the inside of the corner is covered with cushioning material 40 to protect the case of a grand piano P, shown in dash lines in FIGS. 1 and 2, which is to be moved. Web straps 41 are provided to secure the piano P to the frame 20. Mounted on the elongated frame are a plurality of spacer or support blocks 42 which may be adjusted in height to conform the upper surface of the frame 20 to the underside of the piano P. These blocks, which FIGS. 3 and 4 show in greater detail, include upper and lower wedges 46 and 48. The wedges slide in relation to each other so that an upper surface 50 of the upper wedge 46 raises or lowers, but is always parallel to the upper surface of the elongated frame 20. The lower wedge 48 is permanently affixed to the elongated frame at 52. Plates 54 are provided at each side of the block assembly and are held in contact with the wedges by means of a bolt 56 which extends through both plates and the upper wedge 46. A free, threaded end of the bolt receives a knurled nut 58 which can be finger tightened so that the plates 54 clamp the wedges 46, 48 together in a vise-like manner. The upper surface 50 may thus be locked at a fixed height above the elongated frame 20. Referring again to FIGS. 1 and 2, a pivot rod 62 is mounted on the elongated frame perpendicular to a vertical plane through the longitudinal axis of the frame. The ends of the pivot rod 62 extend beyond the longitudinal rails 30 to form pivot pins 64 for mounting the elongated frame 20 to the jacking carriage 22. When so mounted, the rod 62 serves as a horizontal pivot axis A 1 about which the frame 20 can rotate. The rod 62 is located sufficiently near to the foot plate 36 that, when a piano is supported on the elongated frame 20 with the flat portion of the piano's outer rim resting against the cushioning material 40, the pivot rod 62 is located between and parallel to a first vertical plane extending through the foot plate and the second vertical plane extending through the piano's center of gravity indicated at C. The illustrated pivot rod 62 is permanently attached to the elongated frame 20 because all grand pianos have centers of gravity which are similarly located. If the truck is to be used for moving objects other than pianos, it can be provided with a pivot rod which is positionable at a variety of locations along the frame 20. Also mounted on the frame 20 are a pair of heel pins 68 which extend outwardly from the corner 38. The heel pins 68 extend parallel to the pivot pins 64 and as described below are used for joining the elongated frame 20 to the transport base 24. Referring to FIGS. 1, 5 and 6, the jacking carriage 22 has an inner jacking frame 72 including side rails 74 and a cross rail 76 and also an outer jacking frame 80 including side rails 82 and cross rails 84. The jacking frames 72 and 80 are hinged to each other about a common jacking axis A 2 and extend generally downwardly and outwardly in opposite directions from that axis. The lower ends of the jacking frames are connected by a screw jack mechanism 88 which is manually driven by a crank 90. This mechanism regulates the distance between the lower ends of the frames and thus can be used to vary the elevation of the upper ends of the frames. The lower ends of the jacking frames 72 and 80 are equipped with rollers 94 and 96 so that the frames' lower ends can be moved toward and away from each other along a floor surface F and also the jacking carriage can similarly be moved. The rollers 94 are of conventional design but the rollers 96 are swiveling rollers mounted to the outer jacking frame 80 by means of a spring mechanism 100. The springs are positioned to exert a downward force on the rollers' yokes 102 sufficient to hold the lower ends 104 of rails 82 above surface F when the jacking carriage is carrying only the weight of the elongated frame 20. If a heavier load, such as a piano, is placed on the jacking carriage 22, the springs compress so that the rollers 96 retract and the lower ends 104 come into contact with the floor surface F to laterally stabilize the carriage 22. At the upper ends of the carriage's side rails 82 are upwardly opening notches 108 which receive the pivot pins 64 of the elongated frame 20. The notches 108 are located so that the horizontal pivot axis A 1 lies adjacent and parallel to the jacking axis A 2 when the frame 20 is mounted on the carriage 22. Pivot pin hooks 110 are provided to maintain the pivot pins 64 in notches 108. A preferred transport base 24 which receives the elongated frame 20 from the jacking carriage 22 is shown in FIGS. 1, 2 and 7 as an elongated box which is open at the top. The floor or bed 120 of the box is supported by swivel casters 122 at its corners. Areas of the floor 120 are covered with a layer of padding material 124 which receives and cushions the foot plate 36 of elongated frame 20. One of the base's elongated side rails 128 is hinged at 130 and has two outwardly extending pad eyes 132 which are spaced to mate with two pins 133 on the inner jacking frame 72. Mounted on the floor 120 of the transport base are two brackets 134 which define upwardly opening, heel pin-receiving notches 136 positioned to receive the heel pins 68. The brackets 134 thus serve as a heel brace for the corner 38 of the elongated frame 20. The transport base includes two knurled hand bolts 140 which may be inserted through oversize floor openings 142 and screwed into internally threaded openings in the foot plate 36 to secure the foot plate against the floor. Two intermediate rollers 148 beneath the floor 120 of the transport base are not normally in contact with the floor surface F, but prevent the transport base from "high centering" as it is moved over an uneven surface. The base 24 also has a pair of brake levers 150. By appropriately positioning the levers, floor-engaging portion 152 thereof contact the floor surface F to stabilize the transport base and prevent it from moving. Additional pad eyes 156 are provided at one end of transport base 24 for connecting the transport base to a winching cable or other mechanical moving device. OPERATION To move a grand piano using the above described piano hand truck it is first necessary to close and secure the piano casing keyboard cover and blanket the finished surfaces of the piano case with a padded cover. The piano's pedal mechanism is then removed and set aside. Using the crank 90 the screw jack 88 should be extended to its full length so that the jacking carriage 22 is reduced to its minimum heighth. The elongated frame 20 is then placed on the jacking carriage 22 with its pivot pins 64 resting in the notches 104, as shown in FIG. 1, and the hooks 110 positioned to retain the pivot pins 64 in the notches 104. While holding the elongated frame 20 in a horizontal position, the combined frame and carriage assembly is rolled under the piano and located, as is shown in FIGS. 1 and 2, with the cushioning material 40 positioned snugly against the left side rim of the piano case as near to the front legs as possible. By reducing the extension of the screw jack 84, the frame 20 is then raised until the spacer blocks 42 just contact the bottom of the piano bed. Next the blocks are adjusted so that the piano will be evenly supported on all four blocks and the crank 90 used to slowly further reduce the extension of screw jack 88 and thus raise the piano until the two piano legs nearest the inner jacking frame leave the floor surface F. These two legs will be the first to raise since the piano's center of gravity C is located farther from the foot plate than is the pivot axis through pivot pins 64. At this point the web straps 41 are cinch tightened to snugly secure the piano to the frame 20; and the two elevated legs removed and set aside. Now the screw jack 88 is again fully extended so that the jacking frame is returned to its lowest possible elevation. The transport base is moved into position adjacent the inner jacking frame 72 and secured to that frame by tipping the hinged side rail 128 so that the pad eyes 132 are retained on the pins 133 as shown in FIG. 1. Preferably, the brakes 150 are set with portions 152 engaging the floor surface to stabilize the transport base 24. Next, the hooks 110 are disengaged and the piano slowly tilted (counterclockwise in FIG. 1) about the pivot axis A 1 until the heel pins 68 are received by the notches 136. Thereafter the piano is further rotated about an axis through the heel pins 68 so that the pivot pins 64 leave notches 108 and eventually the foot plate 36 comes to rest against the padding material 124. The foot plate 36 may then be secured to the floor 120 by the knurled hand bolts 140 and the hinged side rail 128 returned to an upright position and secured. When the remaining piano leg is removed and the brakes released, the transport base 24 with the piano positioned thereon can be moved to any desired location. Once the piano is delivered to the desired location, it is reassembled by following the aforesaid steps in reverse order. FIGS. 8 and 9 show a second embodiment of the present invention which is similar to the embodiments shown in FIGS. 1 thru 7. The most notable difference is that the second embodiment has an elongated support frame 20', a jacking carriage 22' and a transport base 24' which are permanently secured together as an integral unit. Specifically, the jacking frames 72' and 80' and the elongated frame 20' are retained on and pivot about a single pair of pins 157. Also, the lower end of the inner jacking frame 72' is permanently hinged at 158 to the transport base 24'. The screw jack of the first embodiment is replaced by a winch 160 on the outer jacking frame 80' and a cable 162 which connects by means of a hook 164 to the transport base 24'. The operation of the second embodiment is identical to that previously described except that none of its major components are ever separated. For example, the jacking carriage 22' does not become detached from the elongated frame 20' when the piano body is rotated into a vertical position. Instead, the inner jacking frame 72' is carried by the elongated frame 20' into the vertical position as shown by dotted lines in FIG. 9. When this occurs the cable 162 becomes slack and may be unhooked from the transport base 24'. After the cable is unhooked, the outer jacking frame 82' is rotated (counterclockwise in FIG. 9) about the pins 156 until it extends vertically upward. Prior to moving of the piano, the outer jacking frame 80' is secured to the elongated frame 20' and the cable 162 wound completely onto the winch 160 or otherwise stowed. Thus when the second embodiment is used, the entire hand truck assembly travels with the piano. While I have shown and described preferred embodiments of my invention, it will be apparent to those skilled in the art that changes may be made without departing from my invention in its broader aspects and that my invention can be used to move other heavy objects, such as pool tables, which are supported by detachable or retractable legs.

A grand piano hand truck comprising an elongated piano-receiving frame pivotally supportable on an A-frame jacking carriage is disclosed. A transport base positioned adjacent the carriage receives the piano and elongated frame so that the piano is supported on its side during transit.

RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 61/755,737 which is hereby incorporated by reference. FIELD OF THE INVENTION The present disclosure is related to the field of optical measuring techniques, in particular, optical measuring techniques for measuring the thickness and refractive index of liquid layers. BACKGROUND OF THE INVENTION Interferometry refers to the superposition of electromagnetic waves in order to extract information about those waves. Low-coherence interferometry (LCI) is an interferometry technique utilizing low-coherence light sources. LCI allows for precise measurement of the amplitude and the relative phase of reflected or backscattered light. One common type of interferometer is a Michelson optical interferometer. Michelson interferometers have a light source, a beam splitter which splits the light into a reference arm and a measurement arm and a light detector. The measurement beam is reflected from the specimen being analyzed. The time required for the measurement beam to travel back along the measurement arm and arrive at the light detector depends on the various refractive indexes in the different layers of the specimen. The reference mirror is positioned on a movable delay line to allow the time delay of the reference arm to be adjusted and matched to the time delay of the light reflecting off of the specimen and travelling through the measurement arm. The light from the reference mirror and the light from the specimen, which have multiple partial reflections at multiple delay times, are then recombined and detected. The optical distance of the reflecting regions in the specimen are determined by analyzing the recombined light beam as detected by the light detector. Optical low-coherence reflectometry (OLCR) is an interferometry technique for one-dimensional optical ranging where the amplitude and longitudinal delay of backscattering from a specimen are resolved using a Michelson interferometer incorporating a low-coherence light source. This technique can resolve surfaces spaced by less than 10 μm and can detect optical power reflectivities as low as −136 dB. OLCR Michelson interferometers can be constructed using fiber optic components, thus minimizing their size and weight, and lowering the requirements for the alignment. Referring to FIG. 1 , an example of a basic OLCR interferometer is shown. Such an interferometer includes: a low-coherence source (A); a source-to-isolator fiber (B); an isolator (C); an isolator output fiber (D); a fiber coupler (E); a test arm fiber (F); a reference arm fiber (I); a mirror (H); a detector fiber (J); and a light detector (K). Light travels from the low-coherence source (A) through the source-to-isolator fiber (B), the isolator (C) and the isolator output fiber (D) to the fiber coupler (E), which splits the beam between the test arm fiber (F) and the reference arm fiber (I). Light in the test arm fiber (F) travels to the specimen (G), and is reflected back through the test arm fiber (F). Light in the reference arm fiber (I) travels to the mirror (H) and is reflected back through the reference arm fiber (I). The reflected light from the test arm fiber (F) and the reflected light from the reference arm fiber (I) are recombined in the fiber coupler (E). The recombined light travels through the detector fiber (J) to the detector (K). The isolator (C) prevents reflected light from interfering with light from the source (A). When the optical path length to the mirror (H) is equal to the optical path length to a reflection in the specimen (G), the reflected light from the test arm (F) and the reflected light from the reference arm (I) add coherently to produce coherence fringes (known as coherence spikes) at the light detector (K). To improve the detection of the coherence signal, the reference arm (I) can include a phase modulation device. In some embodiments, the phase modulation device has a vibrating mirror; in other embodiments, the phase modulation device has an electro-optic phase modulator. The amplitude of the coherence signal is a function of the reflection coefficient of the specimen (G). In some embodiments, the amplitude of the coherence signal can be proportional to the square root of the product of the powers in the reference and signal channels. Thus, translating the mirror (H) to vary the optical path length of the reference arm (I) allows the reflectivity profile of the specimen (G) to be mapped. When the optical path length difference is larger than the coherence length of the source (A), the coherence signal no longer exists. The coherence length of a source L c is determined by the following equation: L c = λ 2 n ⁢ ⁢ Δ ⁢ ⁢ λ In this equation, n is the refractive index of the test material, λ is the average source wavelength, and Δλ is the source spectral width. One potential application for OLCR is in the field of hydrocarbon condensation measurement systems used in the oil and gas industry. These systems must be capable of accurately quantifying small amounts of liquids under extreme temperatures and pressures. For the purposes of chemical analysis, it is also desirable that such systems be capable of accurately measuring the refractive indices of liquids. Fiber optic systems have a number of advantages over other types of prior art liquid measurement systems, including immunity to electromagnetic interference, the ability to operate in a wide variety of environmental conditions, high sensitivity and the potential for multiplexing. Current fiber optic liquid measurement systems are often complex and sensitive to external disturbances. Many of these systems are designed to measure only the refractive indices of test liquids and are not capable of measuring the thickness of a liquid layer. Furthermore, they require a fiber tip to be inserted into the test liquid. Current fiber optic liquid measurement systems capable of measuring the thickness of a liquid layer require an optical reflecting surface separate from and behind the test liquid. Such systems also require a large lens surface to collect the light reflected from the test liquid. It is therefore desirable to provide an apparatus and method for measuring the quantity and optical parameters of a liquid in a container using the principle of optical low coherence reflectometry that overcomes the shortcomings of the prior art. SUMMARY OF THE INVENTION An apparatus for measuring the quantity and optical parameters of a liquid in a container using the principle of optical low coherence reflectometry is provided. In some embodiments, the apparatus includes: a source arm having a low coherence light source; a reference arm with a reference lens, a mirror, means for adjusting the distance between the reference lens and the mirror and means for measuring the distance between the reference lens and the mirror; a test arm with a test lens; means for dividing the output of the source arm between the test arm and the reference arm; means for combining light reflected back into the reference arm and the test arm to create an interference signal; and means for detecting and analyzing the interference signal. In some embodiments, the source arm has an isolator to prevent feedback from the reference arm and the test arm from entering the source arm. In some embodiments, the low coherence light source includes an Erbium-doped fiber amplifier. In some embodiments, the reference arm includes a phase modulator. In some embodiments, the phase modulator includes a function generator and means for oscillating the mirror in accordance with the output of the function generator, with the function generator used to trigger the means for detecting and analyzing the interference signal. In some embodiments, the test lens can be a gradient-index lens. In some embodiments, the means for detecting and analyzing the interference signal includes a photodiode, an operational amplifier circuit, an analog-to-digital converter and a computer. In some embodiments, the source arm, the reference arm, the test arm, the means for dividing the output of the source arm between the test arm and the reference arm and the means for combining light reflected back into the reference arm and the test arm to create an interference signal all include fiber optic components. A method for calculating the thickness t and refractive index n of a liquid in a container is provided. In some embodiments, the method includes: providing an apparatus for measuring the quantity and optical parameters of a liquid in a container using the principle of optical low coherence reflectometry, the apparatus including a source arm having a low coherence light source; a reference arm having a reference lens, a mirror, means for adjusting the distance between the reference lens and the mirror and means for measuring the distance between the reference lens and the mirror; a test arm comprising a test lens; means for dividing the output of the source arm between the test arm and the reference arm; means for combining light reflected back into the reference arm and the test arm to create an interference signal; and means for detecting and analyzing the interference signal; fixing the test lens in place with respect to the container with the test lens aimed through the container toward the bottom of the container; establishing a baseline optical path distance for light reflecting off of the bottom of the empty container by manipulating the distance between the reference lens and the mirror until the maximum interference signal is detected and assigning a value of X 0 to the distance between the reference lens and the mirror in that position; placing the liquid in the container or allowing the liquid to accumulate in the container; establishing the optical path distance for light reflecting directly back from the bottom of the container by manipulating the distance between the reference lens and the mirror until the first strong maximum interference signal is detected and assigning a value of X 1 to the distance between the reference lens and the mirror in that position; establishing the optical path distance for light reflecting from the bottom of the container after being reflected from the bottom of the top of the liquid by manipulating the distance between the reference lens and the mirror until the second weak maximum interference signal is detected and assigning a value of X 2 to the distance between the reference lens and the mirror in that position; and establishing the following relationships: i. ΔX 1 =X 1 −X 0 ii. ΔX 2 =X 2 −X 0 ; iii. ΔX 1 =t·n−t; and iv. ΔX 2 =2t·n−t; and solving the system of equations to determine the thickness t and refractive index n of the liquid in the container. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram depicting a prior art optical low coherence reflectometry system. FIG. 2 is a block diagram depicting one embodiment of an apparatus for measuring the quantity and optical parameters of a liquid in a container using the principle of optical low coherence reflectometry. FIG. 3 is a block diagram depicting one embodiment of a low coherence source. FIG. 4 is a schematic diagram depicting one embodiment of an interference signal detector. FIG. 5 is an X-Y graph depicting an interference pattern after adding liquid into a glass cylinder. FIG. 6 is a side elevation view depicting two reflected beams of an incident beam directed into a volume of liquid. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 2 , an embodiment of an apparatus for measuring the quantity and optical parameters of a liquid in a container using the principle of optical low coherence reflectometry is shown. Broadly stated system 1 includes source arm 200 , test arm 300 , receiver arm 400 and reference arm 500 . More particularly, in this embodiment, measurement system 1 includes: fibers 2 ; wires 3 ; low coherence source 10 ; splitter 20 having input 21 , first output 22 and second output 23 ; first circulator 30 having first port 31 , second port 32 and third port 33 ; test lens 40 ; reference lens 50 ; second circulator 60 having first port 61 , second port 62 and third port 63 ; moveable or oscillating mirror 70 ; function generator 80 having triggering output 82 ; oscilloscope 90 having triggering input 92 ; coupler 100 having first input 101 , second input 102 and output 103 ; and interference signal detector 110 . In some embodiments, in operation, light from low coherence source 10 can pass through fiber 2 and enter splitter 20 through input 21 . Splitter 20 distributes 98% of the source light to first port 31 of first circulator 30 through fiber 2 . The light entering first port 31 of first circulator 30 passes through first circulator 30 to second port 32 , then to test lens 40 through fiber 2 . This light travels through test lens 40 to target 5 and reflects off target 5 back into test lens 40 , then returns to second port 32 of first circulator 30 through fiber 2 . The light entering second port 32 of first circulator 30 passes through first circulator 30 to third port 33 , then to first input 101 of coupler 100 through fiber 2 . Splitter 20 distributes the remaining 2% of the source light to first port 61 of second circulator 60 through fiber 2 . The light entering first port 61 of second circulator 60 passes through second circulator 60 to second port 62 , then to reference lens 50 through fiber 2 . This light travels through reference lens 50 to oscillating mirror 70 and reflects off oscillating mirror 70 back into reference lens 50 , then returns to second port 62 of second circulator 60 through fiber 2 . The light entering second port 62 of second circulator 60 passes through second circulator 60 to third port 63 , then to second input 102 of coupler 100 through fiber 2 . Coupler 100 recombines the light entering first input 101 and the light entering second input 102 and to create an interference light signal, which exits coupler 100 through output 103 and travels to interference signal detector 110 through fiber 2 . Interference signal detector 110 transmits an electric signal to oscilloscope 90 through wire 3 . Oscilloscope 90 displays the signal, which allows the user to identify the positions of oscillating mirror 70 corresponding to interference maxima. In some embodiments, in operation, function generator 80 can send a signal to oscillating mirror 70 through wire 3 to control the oscillation of oscillating mirror 70 . Triggering output 82 of function generator 80 can be connected to triggering input 92 of oscilloscope 90 to allow oscilloscope 90 to accurately capture the electrical signal transmitted by interference signal detector 110 through wire 3 . Referring to FIG. 3 , one embodiment of low coherence source 10 is shown. Low coherence source 10 may include: laser diode 12 ; fibers 2 ; wavelength-division multiplexer 14 ; Erbium-doped fiber 16 ; and isolator 18 . Laser diode 12 supplies light to wavelength-division multiplexer 14 and Erbium-doped fiber 16 through fiber 2 . Wavelength-division multiplexer 14 and Erbium-doped fiber 16 amplify the light, and the amplified spontaneous emission output light passes through isolator 18 into fiber 2 , which can connect to measurement system 10 . Isolator 18 prevents feedback from measurement system 10 from passing through. Referring to FIG. 4 , one embodiment of an interference signal detector 110 is shown. Interference signal detector 110 may include: photodiode 115 having first end 116 and second end 117 ; first operational amplifier 122 having positive input 123 , negative input 124 and output 125 ; second operational amplifier 126 having positive input 127 , negative input 128 and output 129 ; 10 pF capacitor 130 ; 300 kΩ resistor 132 ; 390 kΩ resistor 134 ; 1 kΩ resistor 136 ; 100 kΩ resistor 138 ; 10 nF capacitor 140 ; 330 pF capacitor 142 ; and circuit ground 144 . Together, these components act to amplify the signal produced by photodiode 115 to provide an amplified output signal at output 129 of second operational amplifier 126 . This amplified signal can then be captured and analyzed in order to locate the interference maxima. With respect to the methods and apparatuses used to demonstrate the embodiments disclosed above, various solid and liquid targets were tested with the OLCR measurement system by putting them in front of the test arm 300 and scanning the reference arm 500 to locate the maximum interference signal. Foam polyethylene was used as a solid target to represent a non-uniform medium with phase boundaries. In the case of foam polyethylene multiple interference, maxima that corresponded to the boundaries of the foam cells could be observed. In the case of liquids, simultaneous measurements of physical thickness and refractive index were carried out. For these studies, three liquids i.e. Hexane, Chloroform and diluted crude oil were used. These measurements were first done in the visible glass cylinder, and then in a high pressure cell. During these measurements, first, the position of the interference maxima for the empty cylinder was determined, and then with the addition of liquid the corresponding change in the maximum interference signal was recorded. Two maxima were observed after adding the liquid into the cylinder, and one maximum is found stronger in comparison of other maxima as illustrated in FIG. 5 . As shown in FIG. 5 , X 0 is the position of interference maximum without any liquid in the cylinder; X 1 is the position of maximum when liquid was added and X 2 is the position of second maximum. Referring to FIG. 6 , reflections from the bottom of the liquid with refractive index n and thickness t are shown. Beam 1 is the scattered beam from the surface at the bottom of the liquid, whereas Beam 2 is the doubly scattered beam from the bottom of the top surface of the liquid. As shown in FIG. 6 , the first strong maximum is the reflection from the bottom of the liquid in the cylinder. The second weak maximum is the double reflection from the bottom surface of the cell of light reflected from the bottom of the liquid layer. In case of clear liquid, no reflection was observed reflected directly from the top surface of the liquid since the alignment was not adjusted perfectly perpendicular to this layer. Referring to FIG. 6 , the extra optical path traveled by beam 1 is given as Δ X 1 =t·n−t   (5.1) And for beam 2 it is given as Δ X 2 =2 t·n−t   (5.2) Where ‘t’ is the thickness and ‘n’ is the refractive index of the liquid. ΔX 1 and ΔX 2 are the total extra path lengths. So from the equations 5.1 and 5.2 we have two unknown parameters n and t and by solving these two equations algebraically we get the refractive index and the thickness of the liquid samples as given below: t = Δ ⁢ ⁢ X 2 - 2 ⁢ Δ ⁢ ⁢ X 1 ( 5.3 ) n = Δ ⁢ ⁢ X 2 - Δ ⁢ ⁢ X 1 Δ ⁢ ⁢ X 2 - 2 ⁢ Δ ⁢ ⁢ X 1 == 1 + Δ ⁢ ⁢ X 1 Δ ⁢ ⁢ X 2 - 2 ⁢ ⁢ Δ ⁢ ⁢ X 1 ( 5.4 ) With the help of these equations, measurements of the liquid parameters in the glass cylinder and the blind test cell were carried out. Due to the physical construction of the glass cylinder and the blind test cell, they may have some meniscus on the liquid layer and some extra liquid is used to fill in small gaps in the bottom surface before getting the correct results. The amount of this extra liquid is called blind volume, and may also be calculated. The test experiments were performed with different liquids and the thickness and refractive index were calculated for these liquids. A key advantage to the apparatus and method of the invention is the diffuse reflection from the bottom surface which takes advantage of the fact that the interferometric detection is very sensitive to weak reflected signals and, thus, in some embodiments, only a tiny return signal is required for the detection to work. In some embodiments, there is no requirement for precise alignment of the test beam in order to receive the back reflected signals directly into the collection lens. In one example application (a high pressure test cell), the measurement system can be inserted through a narrow opening (1-3 mm in diameter maximum due to the extremely high pressures up to 30,000 psi) in the top of the high pressure test cell. A fibre coupled source plus GRIN lens can be inserted through such an opening. If one had to align the back reflected light directly into the tiny 1 mm diameter GRIN lens after the propagation length of 30 cm to the bottom of the test cell, an accurate optical alignment system would be required which is totally incompatible with the very rough (high temperature, high pressure and high vibration—solutions are mixed physically by shaking) environment in which the tests are carried out. Thus, by using diffuse scattered light, in some embodiments, backscattered signals can be received without precise alignment. In some conditions, the diffuse reflecting surface can have just the right amount of scattering to diffuse the light into a relatively narrow cone angle, for example, approximately 5 degrees so that the light will not be totally dispersed, and the signals not too weak. This can be particularly true for the signal reflected from the top surface of the liquid, which is scattered once from the bottom to the liquid surface and scattered again from the surface back to the detector. In some embodiments, unpolished machined metal surfaces work fairly well in this regard. In some embodiments, the downward scattered signal from the liquid surface can be used for the measurement rather that the direct reflected signal from the liquid surface directly back into the detector that other measurement systems would use. Although a few embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications can be made to these embodiments without changing or departing from their scope, intent or functionality. The terms and expressions used in the preceding specification have been used herein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the invention is defined and limited only by the claims that follow.

An apparatus for measuring the quantity and optical parameters of a liquid in a container using the principle of optical low coherence reflectometry is provided, the apparatus having: a source arm with a low coherence light source; a reference arm including a reference lens, a mirror, means for adjusting the distance between the reference lens and the mirror and means for measuring the distance between the reference lens and the mirror; a test arm with a test lens; means for dividing the output of the source arm between the test arm and the reference arm; means for combining light reflected back into the reference arm and the test arm to create an interference signal; and means for detecting and analyzing the interference signal.

BACKGROUND OF THE INVENTION 1. Field of the Invention Invention relates to data compression and, more particularly, to methods and apparatus for compressing data comprised of digital signals. 2. Brief Description of the Prior Art As is well known in the art, data can be generated by or transferred from one device at a higher rate than another device, which it is desired that the data can be permanently or temporarily stored there within or processed thereby, can receive or operate upon the data. Numerous methods are known in the prior art to compress data. Some of these methods result in an output of the compressor from which it is not possible to reconstruct the data in its entirety. Others utilize an encoding method known as run length encoding. An example of an apparatus utilizing run length encoding is shown in U.S. Pat. No. 3,502,806, issued to Townsend on Mar. 24, 1970 and entitled "Modified Run Length Data Reduction System". Townsend discloses a encoding technique in one embodiment of the invention which encodes both successive (redundance) binary digits of data and redundant background information. In Townsend the data being transmitted consist of logic "1" and "0" data words. These logic words represent the data scanned. The system of data compression shown in U.S. Pat. No. 3,909,515, issued to Evansen on Sept. 30, 1975 and entitled "Facsimile System With Memory" is comprised of a memory which has each storage element assigned a unique address. A full line of data is stored in the memory. As the line is being fed into the memory the system will transmit the address of the first black area contained therein. At a later time the end address of that block of data is located and transmitted. At a later time, the data between the first and end addresses of that block of data is transmitted. This process is repeated until all the blocks of data on the line have been transmitted. The apparatus is then prepared to receive another line of data and repeat the above described operation. None of the constructions or methods shown in the prior art disclose a system for compressing digital data which has an output from which the original data can be fully reconstructed and which eliminates redundancy between adjacent digital signals within the data stream and certain closely related primary signals in the data stream. SUMMARY OF THE INVENTION In the present invention, a data lift, information source (such as a communications link), or other device generates a stream of digital signals such as four bit data words. The data lift could be any of the numerous devices known in the art, for example, a photo cell array. The present invention includes a memory means for receiving and storing the digital signals serially therein. A logic sequencer in the present invention monitors and compares the data contained in the memory means. The logic sequencer directs and controls the memory means and a multiplexer also included in the present invention. The memory means serially presents the data serially stored therein to the multiplexer. The multiplexer transfers that data to its output if commanded to do so by the logic sequencer. The logic sequencer inclues a means for eliminating from the data stream trains of redundant data and substituting a redundance count at the proper location in the data stream therefor. Further, the logic sequencer includes a means for eliminating a primary, frequently occurring, digital signal, for example, those signals representing background data and substituting an address indicating the locaiton of the next data which is not one of the primary signals. In other words, the primary signal is replaced by an individualized address which indicates the location of the next data word which is other than a primary signal. Both the means for eliminating redundant data and the means for eliminating primary signals generate control markers which indicate that an address or alternatively a redundancy count has been inserted into the data stream. These means also through the logic sequencer direct the multiplexer to select the control markers and the redundancy count for row address as desired. The memory means utilized can be a series of connected shift registers. The logic sequencer receives a scan start pulse from the data lift or other device that a scan or the beginning of a block of data has begun to be transferred to the memory means. In addition, the logic sequencer receives data timing pulses from the data lift indicating the rate at which the digital signals are being generated or transferred. This information is utilized to clock the data through the shift registers and allows the logic sequencer to insert the control markers, redundancy counts, and addresses at their proper locations within the data stream. The means for eliminating redundant data within the logic sequencer counts the number of redundancies in a train and, if the number of redundancies is over a predetermined amount such as four redundant signals a redundancy count is substituted therefor after the first redundant signal is transferred through the multiplexer. If the count is less than or equal to the predetermined value, the redundant train is allowed pass through the multiplexer. When a primary signal such as a digital signal indicating a white background i.e. 0000 and perhaps other closely related minimal values such as 0001 are detected, the multiplexer under control of the means for eliminating primary signals within the logic sequencer generates a control marker which can be the primary signal, for example, 0000. When a digital signal is received by the shift registers which is other than the primary signal or the group of closely related signals, the address of that digital signal within the scan or row is outputted through the multiplexer and the digital signal which is not one of the primary signals is passed through the multiplexer after the row address has been passed. Thus, the logic sequencer compares adjacent digital signals within the data stream to determine if a redundancy exists and monitors the stream to locate the primary signals within the data stream. It can be desirable that redundancy be determined by making a magnitude of difference calculation between the digital signals in adjacent shift registers. If that magnitude of difference is of a certain predetermined minimal value, the signals are determined to be redundant even though they are not identical. Thus, the data compressor compensates for minor variations of magnitude within the train of redundant signals. Different control markers are provided to indicate whether or not the information associated with a particular control marker is a redundancy count or an address. The logic sequencer is adapted to generate and transfer timing information to the device which receives the compressed data. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a data compressor constructed according to the present invention with associated input and output devices; FIGS. 2 is a more detailed block diagram of a portion of the data compressor of FIG. 1; FIG. 3 is a detailed logic diagram of portions of the data compressor as shown in FIG. 2; FIG. 4 is a more detailed block diagram of a portion of the data compressor and a portion of the associated devices of FIG. 1; FIG. 5 is a more detailed block diagram of a portion of the associated output devices of FIG. 1; FIGS. 6, 7, 8, and 9 comprise a detailed logic diagram of the controller of FIG. 4; and FIGS. 10 and 11 are functional flow diagrams of the data compressor shown in FIGS. 2, 4 and 5. DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1 the data compressor 20 of the present invention receives digital signals generated by a data lift 22 through a multi-line channel 25. A memory or storage device 28 receives the digital signals generated by data lift 22 serially and stores them in the order received. The memory device 28 can be comprised of a plurality of serially connected shift registers. Each digital signal received from data lift 22 is stored within memory 25 and shifted through the series of registers. The digital signal stored in the last register of memory 28 is shifted out of the serially connected plurality of registers. The last shift register is connected through a multi-line channel 30 to a multiplexer 33. The data lift 22 also has outputs on lines 37 and 38 to a logic sequencer 41 of data compressor 20. Data lift 22 generates a begin scan or scan start pulse on line 37 as a new block or row of digital signals is transferred by data lift 22 to the memory 28. Data lift 22 also generates a data timing pulse on line 38 as an indication to sequencer 41 that a new digital signal is present on channel 25. The digital signal on line 25 could be for example, a 4-bit data word transferred in parallel from data lift 22 to memory 28. It is readily apparent that if memory 28 is composed of a plurality of shift registers those shift registers must be adapted to receive at least four lines of input in parallel and transfer that data word in parallel through the serially connected shift registers and through channel 30 to multiplexer 33. The data lift 22 can be any device well known in the art which generates a digital signal or word as an output. It could be for example, an optical character recognition (hereinafter referred to as OCR) system which is reading data from a written medium on a row by row basis. The data lift could also be the output of a MICR data lift. If the data lift 22 is an OCR device the four-bit digital signals transferred by data lift 22 to memory 28 represent the output of each cell of a photocell array which has been converted from an analog signal to a four-bit digital word representing various levels of grey. If data lift 22 is an OCR device with a linear array, the begin scan pulse on line 37 indicates the beginning of a scan of the linear array and the timing pulses on lines 38 would represent the appearance of each digital signal representing one cell of the photocell array as an output from data lift 22 on channel 25. The logic sequencer 41 also receives inputs from a storage means 45 which could for example be a digital computer with a random access memory and other storage devices. Storages means 45 is by way of example only. The output of compressor 20 could be connected to a processor. The output of storage means 45 through multi-line channel 49 is necessary to indicate to sequencer 41 when the storage means 45 is prepared to receive the compressed data. The other input to sequencer 41 is from memory 28 through multi-line channel 52. The inputs on channel 52 are the output of data lift 22 on channel 25 and the next adjacent digital signal in the stream stored in memory 28. In other words, sequencer 41 receives both the current output of the data lift 22 and the last digital signal transferred from data lift 22 and stored within memory 28. If memory 28 is a plurality of shift registers, sequencer 41 receives and monitors the output of the first shift register in the plurality of serially connected shift registers in addition to the output of data lift 22. Sequencer 41 provides a clock pulse on line 56 which is synchronized with the pulse on line 38 to shift the data through the memory 28 at the same rate as it is generated within the data lift 22. Logic sequencer 41 also has outputs to multiplexer 33, byte storage register 59, and first-in first-out (hereinafter referred to as FIFO) memory device 63. Logic sequencer 41 provides selection signals to multiplexer 33 through multi-line channel 67. Channel 69 between logic sequencer 41 and multiplexer 33 allows logic sequencer 41 to strobe the multiplexer to form a part of the control markers (to be discussed in detail hereinafter). The other two multi-line channels 72 and 73 connected between logic sequencer 41 and multiplexer 33 provide multiplexer 33 with a count of the number of redundant signals in each train of redundant signals and the address of the next signal which is not of a group of primary signals, respectively, as generated by logic sequencer 41. The output of logic sequencer 41 to byte storage register 59 goes through multi-line channel 77 and includes timing and sequencing signals. The other input to byte storage register 59 is from multiplexer 33 through multi-line channel 79. Multi-line channel 79 carries the output of multiplexer 33 as selected by logic sequencer 41. The final output of logic sequencer 41 is to FlFO device 63 through multi-line channel 82. Multi-line channel 82 carries timing pulses to control the flow of digital from byte storage register 59 through the device. Byte storage 59 is connected to FlFO device 63 through a multiline channel 85. Finally, FlFO memory 63 has its output connected through multi-line channel 88 to the storage means 45. The timing signals on multi-line channel 82 are in part a result of the output of the storage means 45 on channel 49 to logic sequencer 41 to indicate if the storage means is prepared to receive data from the FlFO memory 63. Briefly the data flow through the block diagram of FIG. 1 is that the four-bit digital signal generated by the data lift 22 is passed serially through memory 28, four-bit digit signals appear at the output of multiplexer 33 as selected by logic sequencer 41 (which could be the digital signals generated by data lift 22, a control marker, a redundancy count, or an address) to byte storage register 59. The four bit digital signals from the output of multiplexer 33 are stacked within byte storage register 59 and formed into 24 bit words referred to as bytes which are passed to FlFO device 63 24-bits at a time. After storage within FlFO memory 63, the 24-bit words appear in the proper sequence at the output of memory 63 to storage means 45. in FIG. 2, the outputs of data lift 22 (FIG. 1) on channel 25 and lines 37 and 38 are inputs to a input select and synchronization circuit 94. Circuit 94 can be adapted to select between the outputs of several data lifts or test circuits as desired. In normal operation the digital signals on line 25 are shifted directly through a shift register in circuit 94 and into the first shift register 100 of the memory 28. The shift registers 100 through 104 are serially connected to move the digital signal received by the first shift register 100 from channel 25 through the memory 28 so that each digit signal appears as the output of the last shift register 104 in the identical order as received from channel 25. Unless it is desired to select between different streams of data it would be unnecessary for the channel 25 to pass through circuit 94. As shown in FIG. 2, portions of circuit 94 are in both the memory 28 and the logic sequencer 41 of FIG. 1. Each of the shift registers 100 through 104 of memory 28 receives timing pulses on line 56 originating on line 38 which causes the register to transfer its input to its output. Thus, the output of shift register 100 which is received through multi-line channel 110 by shift register 101. The digital signal which is present on channel 110 as an output of shift register 100 is transferred to the output of shift register 101 and appears at the inputs to shift register 102. Thus, as the data timing pulses on line 56 are received by the shift registers, the digital signals are moved through the memory 28 until they eventually appear as the output of the last shift register 104 of the plurality of shift registers within the memory 28. The output of shift register 104 is received by the multiplexer 33 (FIG. 1) on channel 30. As shown in FIG. 2, the channel 52 of FIG. 1 has been broken into two multi-line channels 118 and 119 which are connected to a magnitude of difference calculator 123 and a shift register 124, respectively. The output of the shift register 124 is an input to the magnitude of difference calculator 123 through multi-line channel 125. The results of the magnitude of difference calculation are received from the calculator 123 by comparator 127 through multi-line channel 129. A storage unit 132, which should be a shift register, has an input on multi-line channel 135 which is adjustable either manually or through examination by a processor (not shown) which is also receiving the digital signals from data lift 22. The signal on channel 135 is stored within storage unit 132 as its output. The output of unit 132 is connected to comparator 127 through multi-line channel 137. A line 140 is provided to indicate to storage unit 132 that the signal present on channel 135 should be transferred to its output. If the output of the magnitude of the magnitude of difference calculator 123 is greater than the output of storage unit 132, the output of the comparator on line 134 will go high and its output to line 146 goes low. Both the output on line 144 and 146 is connected to redundancy counter 150. Redundancy counter 150 counts the pulse on line 144 each time the pulse goes high. Further, redundancy ocunter 150 is reset to zero each occasion that the output of comparator 127 on line 146 goes low indicating that input to shift register 100 and its output are not redundant. Thus, redundancy counter 150 counts each redundant signal in a train of redundant digital signals that are closely related. Put another way, redundancy counter 150 counts each signal of a train of digital signals which differ by the set predetermined amount stored in storage unit 132 as redundant. If it is not desired to count as redundant those signals which are close in magnitude to the redundant signal being counted line 118 and line 119 could be connected to the inputs of comparator 127 as channels 129 and 137 are connected to comparator 127 as described above or the value stored within unit 132 can be set to zero. The output of redundancy counter 150 is received by a data redundant indicator 160 and a redundancy count storage unit 164. The data redundant indicator 160 also has line 144 as an input. Redundancy indicator 160 structured so that its output of line 168 goes high if three counts are present in redundancy counter 150 and another high signal on line 144 indicating that another redundancy is received. Further, the output of data redundant indicator 160 is high if four or more counts are present in redundancy counter 150. The output of data redundant 160 on line 168 goes to controller 172 and redundancy count storage unit 164. As long as the output of data redundant indicator 160 is high storage unit 164 transfers the output of redundancy counter 150 to its output. Prior to counter 150 being reset by the not equal output of comparator 127, the output of data redundant indicator 160 goes low and redundancy storage unit 164 ceases to load the output of 150 and retains as its output the last output of counter 150 prior to the not redundant indication from comparator 127. The count stored in redundancy count storage unit 164 goes to a multiplexer 176 through multi-line channels 179 and 180. The output of multiplexer 176 is received by multiplexer 33 through channel 72. The output of the last shift register 104 on channel 30 is an input to a comparator 184 (FIG. 4) as well as to multiplexer 33. The other input to comparator 184 is from a background storage unit 188 through multiline channel 190. The background storage unit 188 receives a background level, which it outputs on channel 190, on multi-line channel 192. If the digital signal on line 30 is greater than the background level, the output of comparator 184 to controller 172 on line 195 goes high. Thus, the output of comparator 184 indicates if the digital signal contained in the last shift register is above a certain predetermined level i.e., above the level of the background of the medium being observed. This background can be determined by a processor or other device or be preset manually. The output of comparator 184 indicates that a digital signal of a certain group of digital signals is currently stored in the last shift register 104. This certain group includes a primary signal and a group of signals closely related thereto. Controller 172 has an output on line 198 to multiplexer 176. The signal on line 198 determines which of the inputs from redundancy count storage unit 164 appears as the output of multiplexer 176 to channel 72. The other outputs of controller 172 are lines 202 through 204, line 206 and multi-line channels 208 and 210; all are inputs to multiplexer 33 except line 206 which is connected to byte storage register 59. Line 202 is connected to the strobe input the individual IC multiplexer units within multiplexer 33 so that when the output of controller 172 on line 202 goes high the output of multiplexer 33 to each of the individual lines within channel 79 is a logic `0`. The individual integrated circuit multiplexing units within multiplexer 33 are typical 0000` four lines of input to one line of output multiplexers and receive their selection signals from controller 172 on lines 203 and 204. The timing pulse from line 37 is an input of controller 172 on line 234. The scan start pulse is an input to controller 172 on line 235 after being delayed within the shift registers so that it is received by the controller as the first digital signal of the scan becomes the output of shift register 104. The pulses on lines 234 and 235 are communicated to an address counter 240 (FIG. 9) included within controller 172. The output of the address counter 240 appears on channels 208 and 210 to multiplexer 33. The output of controller 172 on line 206 to byte storage register 59 provides sequencing signals to byte storage register 59 to insure that the byte storage unit 59 stores and outputs the input from multiplexer 33 after the multiplexer has received the proper selection signals on lines 203 and 204. The sequencing signal on line 206 is inverted by inverter 244 which is connected to byte counter and FIFO sequencer 246 (FIG. 5) through line 248. During the operation of the data compressor 20 the controller 172 through its address counter provides an address for each digital signal with a scan signified by the scan start pulse on line 235. The address counter is zeroed in the preferred embodiment upon the receipt of the scan start pulse and thereafter counts the pulses on line 234 which signify that data is being transferred into the memory 28. If the data is both not redundant and above the level of the background, the controller 172 will select the signal present on channel 30 as the output of multiplexer 33 when that digital signal is stored within the last shift register 104. When a train of more than four redundant signals is encountered within the stream of digital signals, the first redundant signal of the train of redundant signals is passed from channel 30 to channel 79 and loaded into byte storage register 59. The redundant signals of the train are counted and after the last of the redundant signals is received, the controller 172 directs multiplexer 176 to select channel 180 as its output via line 202 and multiplexer 33 to select channel 72, which is the output of multiplexer 176, by the proper selection signals on lines 203 and 204. After the output of redundancy storage register 164 has been loaded into byte storage register 59 subsequent to receiving the load signal on line 206, the controller 172 through line 198 causes multiplexer 176 to select the data on channel 179 as its output while maintaining the same selection signals on lines 203 and 204 and thereafter loading the signals on channel 179 into byte selector 59. During the interval between the loading of the first of the redundant signals of the train and the loading of the redundancy count the output of the controller 172 to line 202 is high which causes multiplexer 33 to output `0000`. This zero or control marker is loaded into byte storage register 59 and thereafter no further load signals are sent by controller 172 over line 206 to the register 59 until the final redundant signal is received and the count is loaded into the register 59. Thus, the train of redundant signals is eliminated from the stream of digital signals. If the controller 172 receives a signal on line 195 from comparator 184 indicating that the digital signal stored in register 104 which is at or below the background the controller 172 through line 202 (which is channel 69 of FIG. 1) sets the output of multiplexer 33 to a logic `0000` and initiates a low pulse to register 59 so that the `0000` signal is loaded into register 59. When a signal above the background level in register 104 is detected by comparator 184, the controller 172 initiates selection signals on lines 203 and 204 and load signals on line 206 with the purpose of loading the parts of the address on channel 210 first and then on channel 208 into register 59 through multiplexer 33. Thereafter the address of the digital signal which is above the background located within register 104 is selected as the output of multiplexer 33 and loaded into register 59. Because the digital signals below the background level are not passed through to byte storage register 59 they are eliminated from the data stream. These digital signals would of course include the logic `0` signals contained within the data stream; therefor, the logic `0000` loaded into byte storage register 59 indicates during reconstruction of the data that the next signals in the data stream represent either a redundancy count or anaddress. The `0000` digital signal is the primary signal of the particular example described in the preferred embodiment. TABLE I DFFFFFFFFFFFFFFFFFFFFFF5000000078A00000000000000 Assuming 48 bits of data per scan and 4 bits per digital signal, table I represents one scan of raw data. Table II shows the output of multiplexer 33 to byte storage register 59 for the raw data shown in table I. Table II.______________________________________COMPRESSED DATAByteNumber Byte Comments______________________________________1 0000 Control byte indicating the next two bytes are address or redundancy count2 00003 0000 Address of 0 indicates Begin Scan4 1101 Data = D.sub.165 1111 Data = F.sub.166 0000 Control Byte7 1001 Most significant byte with most8 0101 significant bit set indicates redundancy count. 1001010 = redundancy count of 21.9 0101 Data = 510 0000 Control byte11 000112 1111 Address of 3113 0111 Data = 714 1000 Data = 815 1010 Data = A.sub.1616 0000 Control17 0000 Address = 018 0000 Start next scan.______________________________________ When the scan start pulse is received by controller 172, it commands via line 202 multiplexer 33 to output logic `0000` and a pulse on line 206 to load the logic `0000` generated by multiplexer 33 into register 59. Two further `0000` digital signals are loaded thereafter. Because the first digital signal is above the background, it is loaded in byte storage register 59. Thus, the first four bit words which are transferred by multiplexer 33 to register 59 are `0000`, `0000`, `0000`, and `1101` (which is the digital representation for the data signal D because there are sixteen levels of grey). The controller 172 provides the proper selection signals on lines 203 and 204 and further provides the proper load signals to register 59 on line 206. The selection signals on line 203 and 204 remain the same and the next digital signal, `1111` (the digital representation for the signal F) is passed through multiplexer 33 and loaded into register 59. Prior to `1111` being loaded into register 59 the redundancy counter 150 and its associated circuits have been counting redundant signals the first F of the train of redundant signals is loaded into register 104. The data redundant indicator 160 supplies the controller 172 with a signal on line 168 which causes the controller 172 not to pass any further load pulses on line 206 to register 59. When the last redundant signal in the train reaches register 104, the count in count storage register 164 is loaded into byte storage register 59 through multiplexers 176 and 33 by controller 172. Controller 172 first generates a logic `1` on line 202 commanding multiplexer 33 to generate the control marker `0000`. The controller 172 then selects the signals on line 180 as the output of multiplexer 176 and the signals on channel 72 as the output of multiplexer 33 (and generates the appropriate load signals to register 59) and then selects the signals on channel 179 to mutiplexer 176 while maintaining channel 72 as the output of multiplexer 33. The most significant bit of the first four bit woud of the count is a logic `1`. This bit and the next significant bit of the first four bit woud are a portion of the control marker in order that the data may be reconstructed at a latter time. The logic `1` in the most significant bit indicates that a redundancy count follows and a `0` indicates that an address follows. Because only 48 signals are in each row only six binary digits are necessary for the redundancy count and the address. Since there were 21 F's following the initial F which was loaded into register 59 the count in binary form is `010101`. The next signal is a single 5 (represented as `0101` digitally) which is loaded into register 59 as discussed above. Because the next digital signal in the stream is `0000` the controller 172 loads a 0000 signal as the output of multiplexer 33 by generating a high signal on line 202. The next signal which is not above the background signal `0000` is a 7 which is the 32nd signal in the stream. Because the addressing system begins at 0 the address of the digital signal represented by the 7 in the raw data table I is 31. In digital representation the address is `011111`. It should be noted that the two most significant bits following the `0000` signal are `00` indicating that the address follows in the next six bits of information, of the data stream. Thus, the `0000` signal and the two most significant bits of the next four bit word form a control marker which indicates that an address follows in the next six bits of information so that the compressed data can be reconstructed when desired. The controller 172 then selects the output of register 104 as the output of multiplexer 33 and loads the digital signal 7, `0111`, into register 59. The data word 8 and the data A, represented by the binary words `1000` and `1010`, respectively, are then loaded as they appear at the output of register 104 into register 59 as discussed above. A zero is the next digital signal in the stream of raw data and therefor controller 172 loads a 0000 into register 59 as discussed above. Because no further bits of information in this particular scan as shown in table I are above the background level when the scan start pulse is received on line 234 the `0000` control marker and the two most significant digits of the next word are `00` and the address is `000000`. On reconstruction of the data the start of a new scan is indicated by the address zero. Thus, the stream of digital signals are compressed so as to eliminate a primary signal or a cluster of primary signals i.e. those signals which are not above the background are eliminated from the data stream and a control marker consisting of six bits, which in the preferred embodiment are six zeros, and an address are substituted therefore. Further, redundancies of four more are eliminated from the data stream and a control marker consisting of six bits i.e. `000010` and a six bit count of the number of redundancies has been substituted therefor. Also, the scan start pulse at the beginning of each row of data are inserted into the data stream in order that the stream as altered by the data compressor of the present invention may be reconstructed on a row by row basis in its entirety. Prior to a detailed discussion of the controller 172 and related components, a utilization of the compressed data stream on channel 85 as shown in FIG. 5 is discussed here below. The byte counter and FIFO sequencer 246 receives the inverted load pulses on line 248. A counter (not shown) within the sequencer counts the pulses on line 248 and outputs a signal to a second counter after counting six load pulses on line 248. A second counter (not shown) counts the output of the first counter within the sequencer 46 from 0 to 3 and then recycles to 0. The output of the second counter goes to the selection terminals of a decoder or demultiplexer. The demultiplexer (not shown) within sequencer 246 has its one line of input tied to a logic `1` voltage source. The four lines 255 through 258 of output each in turn have an output of a logic `1` as they are selected by the second counter. The six load signal count from the first counter is also an output from the byte counter and FIFO sequencer 246 to FIFO input controls 262 through 265 through line 268. Line 255 is connected to FIFO input control 262 and FIFO register 272. Line 256 is connected to FIFO input control 263 and FIFO register 273. Line 257 is connected to FIFO input controller 264 and FIFO register 274, and line 258 is connected to FIFO input control 265 and FIFO register 275. Byte storage register 59 is composed of four individudal IC six bit registers with one line of channel 79, which is comprised of a four lines, connected to each of the registers. The output of the register associated with the input to which the line of channel 79 is attached is connected to a second input of the same register. The output of the second input is connected another input of the same register and so on so that as data is loaded from multiplexer 33 it is stacked so that the most significant bits all six words stored in the register 59 are in one of the individual IC registers. Same is true for the other bits of the four bit words. The output of the register 59 connected to FIFO register 272 through 275. The purpose of register 59 is to stack the four bit words or digital signals in the data stream into a 24 bit word make up of six of the four bit digital signals of the data stream. The FIFO registers 272 through 275 are adapted to receive and store a 24 bit word. Assuming that a 24 bit word has been compiled and that the count of the second counter in the sequencer 246 is zero the output to line 255 goes high which this enables FIFO register 272 stores the 24 bit word on channel 85. After another 24 bit word is compiled in register 59, the count in the second register in sequencer 246 will be 1 and line 256 goes low while lines 255, 257 and 258 remain high which enables FIFO register 273 to store the 24 bit word on channel 85. The operation continues and FIFO register 274 and 275 are also loaded with 24 bit words FIFO register 275 is then loaded with a new word and the operation continues. Each of the FIFO registers 272 through 275 is connected to a FIFO memory 282 through 285, respectively. Each FIFO register 272 through 275 is connected to its associated FIFO memory through a multi-line channel 289 through 292, respectively. All of the FIFO control 262 through 265, all the FIFO registers 272 through 275, and all of the FIFO memories 282 through 285 are identical and a discussion of one group suffices for all. After the 24 bit word has been stored FIFO register 272 and if the output of FIFO memory 282 on line 295 is high indicating that FIFO memory 282 is prepared to receive data, the output of FIFO control 262 to line 298 goes high. The high signal on line 298 causes FIFO memory 282 to store the 24 bit word which is present on channel 289 from FIFO register 272. The particular FIFO memory which is utilized is six, 64 word by 4-bit FIFO memories connected in parallel. Each 64-word by 4-bit FIFO memory receives four bits of the 24 bit word from FIFO register 272. The output of FIFO memory 282 to line 295 goes low after the 24 bit word is stored in the first location of the memory. The 24 bit word is moved into the next location in the memory by the control circuits of the memory and the output to line 295 goes high again. Meanwhile the output of FIFO control 262 to line 298 goes low. The FIFO memory will automatically move the 24 bit words toward its output until all the 24 bit words within the memory are stacked as received from the last location in the memory one 24 bit word at a time back toward the input. In other words, the 24 bit word which has been present in the memory the longest is located at the last memory location in the memory adjacent to the output of the FIFO memory and the 24 bit word which is stored in the memory the next longest is in the second memory location from the output of the FIFO memory. (The 4 × 64 bit FIFO memories being utilized are 3341 serial memories.) The other FIFO control 263 through 265 are connected to FIFO memories 283 through 285 through lines 301 through 303, respectively. The FIFO controls 263 through 265 receive signals from their associated FIFO memories 283 through 285 on lines 306 through 308, respectively. Lines 301 through 303 serve the same function for their associated FIFO control and FIFO memories as line 298 does for FIFO control 262 and FIFO memory 282. Also, line 295 serves the same function for FIFO control 262 and FIFO memory 282 s lines 306 through 308 serve for their respective FIFO controls and memories. The 24 bit words present at the output of FIFO memories 282 and 284 are connected through multi-line channels 313 and 314, respectively, to the inputs of multiplexer unit 317. Another multiplexer 320, which is identical to multiplexer unit 317, receives the outputs of FIFO memories 283 and 285 through multi-line channels 324 and 325, respectively. After a digital signal is loaded to the last location in FIFO memory 282 its output on line 328 to output control 331 goes high. When the computer or other storage device 45 is prepared to receive data on the multi-line channel 334 a signal is passed to controller 331 on line 337. The selection inputs of the individual multiplexers contained within multiplexer unit 317 are connected to line 340 which allows control 331 to select either channel 313 and 314 as the output of multiplexer unit 317 to multi-line channel 344. The 24 bit word transferred in parallel on channel 344 is passed through driver unit 347 wherein an individual driver (amplifier) is provided for each line of the channel. The 24 bit word is received by storage unit 45 from channel 334. If channel 313 is selected as the output and the signal on line 337 indicates that the storage means 45 has accepted the output on channel 334, the output of control 331 to FIFO memory 282 on line 352 goes high and then low, the next 24 bit word stored in FIFO memory 282 is shifted to the output of memory 282 and appears on channel 313. The output of memory 282 to line 320 goes high after the next 24 bit word is transferred to the output of the memory. Control 331 also has an output to line 355 to driver unit 347 which after implification appears on line 358 connected to storage means 45. The signals on line 355 which is generated by control 331 indicate to the storage means input buffers that the data on channel 334 is to be accepted. In addition, control 331 has an output through line 361 to FIFO memory 284 and has an input on line 364 from FIFO memory 384. Lines 361 and 364 serve the same functions for their associated FIFO memory 284 as lines 328 and 352, respectively, for their associated FIFO memory 282. Multiplexer unit 320 has its selection inputs connected to output control 369 through line 371. Control 369 is identical to control 331 and the above functional description with regard to control 331 applies equally to control 369. The selection signals from control 369 on line 371 determine which of the channels 324 or 325 is passed through multiplexer unit and becomes the output to multi-line channel 374. Control 369 receives inputs from FIFO memory 283 and 285 on lines 378 and 379, respectively, and has outputs to FIFO memories 283 and 285 on lines 282 and 283, respectively. Also the control 369 receives an indication concerning the status of the storage means 45 on line 386. Those indications are that the storage means is prepared to accept digital signals on channel 374 transferred to channel 389 after amplification within driver unit 392. Control 369 provides the storage means 45 with an indication through line 394 that the digital signals on channel 389 should be accepted. Line 394 is connected through driver unit 392 and line 396 to control 369. Other status signals and indications concerning the data compressor 20, byte storage register 59, and the FIFO memory 63 can also be passed through driver units 347 and 392, as desired. In operation, assuming that FIFO memory 282 contains the next 24 bit word to be loaded into the storage means 45 and the signal on line 328 is high, control 331 selects through line 340 the signals on channel 313 as the output of multiplexer 317 to channel 344. After channel 313 has been selected, control 331 sends a signal to the storage means through line 355 to indicate that the correct data has been selected and can be stored. After the data is stored the storage means causes a signal to be present on line 337 indicating that the data is stored, and control 331 causes its output to line 352 to go high which causes the next 24 bit word in FIFO memory 282 to move to the output thereof. At the same time control 369 through line 371 causes multiplexer unit 320 to select the signals on channel 324 from FIFO memory 283 as its output to channel 374. After proper data i.e. signals on channel 324 is selected control 369 so indicates to the storage means 45 on line 396. After the digital signals which are outputted by FIFO memory 283 are accepted by storage means 45 and the storage means so indicates on line 386, control 369 causes its output to line 282 to go high which causes the next 24 bit word in FIFO memory 283 to promulgate to the output thereof. Control 331 through line 340 causes multiplexer unit 317 to select the output of FIFO memory 284 on channel 314 as its output to channel 344 and sends a signal so indicating to storage means 45 through line 355. After the data is accepted it is so indicated on line 337 to control 331. Control 331 causes line 361 to go high which causes the next 24 bit word in FIFO memory 284 to promulgate to the output thereof and control 331 selects the output of FIFO memory 282 as the output of multiplexer unit 317 and so indicates on line 355. Control 369 has selected the digital signals on channel 325 from FIFO memory 285 as the output of multiplexer unit 320 and so indicates on line 369 to storage means 45. Control 369, after receiving an indication that the data is accepted by the storage means on line 386, causes line 383 to go high which in turn causes the next 24 bit word in FIFO memory 285 to promulgate to the output thereof. Control 369 selects the digital signals on channel 324 as the output of multiplexer unit 320. It can be appreciated by those skilled in the art that the flow of data through FIFO memory 63 is such that the digital signals are transferred from the byte storage register 59 through the FIFO registers 272 through 275, FIFO memories 282 through 285, and multiplexer units 317 and 320 in order that the 24 bit words which appear on channels 334 and 389 are in the same identical serial order as received by the byte storage register 59. Also it can be appreciated that the individual 4 bit words (digital signals) within the data stream must be kept in the same order as they are generated by or promulgated from the multiplexer 33 within the data compressor 20 in order that the data stream may be reconstructed at a later time. In summary, 4 bit words are generated or transferred through the data compressor 20 as discussed above and are loaded into byte storage register 59. The output of the byte storage regiser 59 is a 24 bit word made up of six of the four bit words from the data compressor. These 24 bit words are transferred in parallel to one of the FIFO registers 272 through 275 wherein they are stored. The particular register to which the word is moved is dependent on a counter within the byte counter and FIFO sequencer 246. For example, if a 24 bit word has just been stored within FIFO register 273 the next 24 bit word transferred from the byte storage register 59 is stored in FIFO register 274. The 24 bit words are transferred in parallel into the FIFO memories 282 through 285 from the FIFO storage registers. The FIFO memories act as elastic storage devices in that they allow for limited periods of time data to be accumulated therein if the data compressor is unable to compress the data being received because of the lack of primary signals and redundancies. Thus, if the digital signals within the data stream are both above the background and not redundant and are being generated at a rate faster than the storage means 45 can accept data, the number of 24 bit words stored within the FIFO memories increase and at a later time when redundancies and signals below the background are again occurring within the data stream the number of 24 bit words within the FIFO memories begin to decrease. The 24 bit words within the FIFO memories are transferred to the storage means 45 in such a way that the sequence of the 24 bit words remains undisturbed. Assuming the next 24 bit word to be transferred is located at the output of FIFO memory 283, it is transferred through multiplexer unit 320 and stored within the storage means 45. The next 24 bit word to be transferred is located at the output of FIFO memory 284 and is transferred through multiplexer unit 317 to the storage means. Next, the 24 bit word located at the output of FIFO memory 285 is transferred through multiplexer 320 to the storage means followed by the 24 bit word appearing at the output of FIFO memory 282 which is transferred through multiplexer 317. The particular utilization of the output of the compressor 20 shown in FIG. 5 is by way of example only and other utilizations are possible, of course. FIGS. 6, 7 and 8 taken together comprise the controller 172 of FIG. 4. J-K flip-flops 401 through 410 (FIG. 6) and J-K flip-flops 412 and 413 (FIG. 7) are the state machines of the preferred embodiment of the present invention. It should be noted that standard clocking and clear techniques are used throughout. (The flip-flops utilized are negative edge triggered J-K flip-flops with a present function). When the signal on line 416 (FIG. 6) and line 418 (FIG. 7) goes low, the flip-flops 400 through 410, 412 and 413 are preset with their outputs to lines 420 through 430, 432, and 433, respectively, high and their outputs to lines 440 through 450, 452, and 453, respectively low. A 50 nanosecond clock pulse is applied to the clock inputs of all of the J-K flip-flops through line 458 (FIG. 6) and line 460 (FIG. 7). Assuming that the controller has been preset to its initial conditions and is prepared to control the flow of data through the data compressor 20, what follows is a discussion of the operation of the controller 172. The scan start pulse on line 235 (FIG. 2) is applied to NAND gate 464 through an inverter 466. The scan start pulse is passed through the shift registers 100 through 104 so that it is delayed as described above. The data timing pulses on line 234 are also received by NAND gate 464. An output of flip-flop 400 (FIG. 6) is connected through line 420 to NAND gate 464 and NAND gate 468 (FIG. 7). The final input to NAND gate 464 is the signal from comparator 185 on line 195. The scan start pulse on line 235 and the data timing pulse on line 234 are also connected to NAND gate 468. Assuming that at sometime the output of NAND gate 477 has gone high (to be discussed herebelow) and the output of flip-flop 400 to line 420 is high, when the next data timing pulse is received by the controller on line 234 the output of NAND gate 468 goes low because all of its inputs are high. If a scan start pulse is not received on line 235 the output of NAND gate 464 goes low. The low output of either NAND gate causes the output of NAND gate 471 (shown as an OR gate with inverted inputs which are referred to herein as NAND gates) to go high which during the next transition of the clock pulse from high to to low causes flip-flop 400 to have a high output to line 440 and a low output to line 420. Assuming that the scan start pulse was not received and, the digital signal in register 104 is above the background (line 195 is high) the low output of NAND gate 464 causes the output of inverter 482 to which it is connected to go high. The high output of inverter 482 is connected through line 485 to the K input of flip-flop 401. During the next high to low transition of the clock pulse on line 458 the outputs of flip-flop 401 to lines 421 and 441 go high and low, respectively. The output of NAND gate 464 to line 484 is also connected to an input of NAND gate 486 (FIG. 8). The output of NAND gate 486 to line 206 is high. Line 206 is connected to byte storage register 59 and to inverter 244 of FIG. 4 as discussed above and carries the load signal. The selection signals on 203 and 204 are both low and the output of counter 500 (FIG. 9) is loaded into the byte storage register 59. The low output of flip-flop 401 after the next clock pulse is connected to NAND gate 490 through line 441. Because one of the inputs to NAND gate 490 is low it's output to line 203 is high. Also, as will be discussed hereinafter, the output of NAND gate 494 is low. The low output of flip-flop 401 to line 441 causes NAND gate 490 to go high which in turn causes a selection of counter 502 (FIG. 9) as the output of multiplexer 33. The high output of flip-flop 401 to line 421 is connected to NOR gate 505. Because one of the inputs to NOR gate 505 is high its output which is connected through line 508 to NAND gate 486 goes low causing the output of NAND gate 486 to go high. This high signal one line 206 causes byte storage register 59 to load the output of counter 502. Line 421 is also connected to the K input of flip-flop 402 and to its own J input which means that during the next high to low transition of clock pulse the output of flip-flop 401 to line 421 goes low and the output of flip-flop 402 to line 422 goes high. Correspondingly the output of flip-flop 401 to line 441 goes high and the output of flip-flop 402 to line 442 goes low during the same clock pulse. The low output of flip-flop 402 to line 442 is connected to NAND gate 512 (FIG. 7), NAND gate 490 and NAND gate 494 (FIG. 8). Also, line 422 is connected to the J input of flip-flop 402 and an input of NOR gate 505. Thus, when the outputs of flip-flop 402 to lines 422 and 442 go high and low, respectively, the outputs of NAND gates 486, 490 and 494 go high. This causes the digital signal present in shift register 104 to be selected by multiplexer 33 and loaded into byte storage register 59. Because the output of flip-flop 402 to NAND gate 512 is low, the output of NAND gate 512, which is connected to the K input of flip-flop 403 through line 513 is high. During the next high to low transition of the clock pulse the outputs of flip-flop 403 to lines 423 and 443 go high and low, respectively. The high output of flip-flop 403 to line 423 goes to AND gate 515, and gate 517, NAND 519 (FIG. 7) and NAND gate 521 (FIG. 8). The other input to NAND gate 521 is the data timing pulse on line 234. When the data timing pulse is received by NAND gate 521 its output goes low which causes the outputs of NAND gates 486, 490 and 494 to go high. The high outputs of NAND gates 490 and 494 cause a multiplexer to select the four bit word stored in register 104 as its output and the high output of NAND gate 486 causing the selected output of the multiplexer 33 to be loaded into byte storage register 59. However, if the signal on line 523 is high indicating that the data is below the level of the background as determined by comparator 184, the output of NAND gate 519 (FIG. 7) to line 528 goes low during the data timing pulse which causes NAND gate 526 (FIG. 8) to go high. The multiplexer 33 generates a `0000` digital signal as its output despite the selection signals provided by NAND gates 490 and 494. The high signal on line 206 causes the byte storage register 59 to store the `0000` output of the multiplexer. Line 528 is connected to NAND gate 531 and through an inverter 530 and line 532 to NAND gate 535. If the data is below the background level as indicated on line 195 all of the inputs to NAND gate 515 are high. Its output goes low which causes the output of NAND gate 477 to flip-flop 400 to go high which in turn causes flip-flop 400 to have its output to line 420 to go high during the next high to low transition of the clock pulse. The logic then continues as discussed above in connection with flip-flop 400. If on the other hand the count in counters 500 and 502 had been 47, NAND gate 515 remains high because its input from NAND gate 538 (FIG. 9) is low. NAND gate 538 is connected through line 541 to counters 500 and 502 and goes low only when the count in the counters is 47. When the count equals 47 NAND gate 535 (FIG. 7) goes low because it is connected to NAND gate 538 through inverter 544 and through inverter 530 to NAND gate 519 which is low because the data is below the background level. The low output of NAND gate 535 causes NAND gate 548 to go high which during the next high to low transition of the clock pulse causes the output of flip-flop 412 to lines 432 and 452 to go high and low, respectively. The low output of NAND gate 519 is also applied to an input of NAND gate 551 which causes NAND gate 551 to go high. The high output of NAND gate 551 is applied through line 553 to the J input of flip-flop 403 which causes the output of a flip-flop 503 to lines 423 and 443 to go low and high respectively at the same time as setting of flip-flop 412 as discussed above. Also as discussed above the low output of NAND gate 519 causes multiplexer 33 to generate a `0000` output. AND gate 517 goes high if the digital signal in shift register 104 is greater than the background and the output of flip-flop 403 to line 423 is high and the data timing pulse is received on line 234. If the count in counters 500 and 502 is equal to 47 the output of NAND gate 555 to line 557 goes low. The output of NAND gate 555 is connected through line 557 to NAND gate 551 and NAND gate 559. The high output of NAND gate 551 causes flip-flop 403 to flip-flop as discussed above and the output of NAND gate 559 to go high. The output of NAND gate 559 is connected through line 562 the J input of flip-flop 404 which causes the output of flip-flop 404 to line 424 and 404 to go high and low, respectively. The high output of flip-flop 404 on line 424 is connected to NAND gate 526 through inverter 565 and the high output of NAND gate 526 (FIG. 8). The low output of inverter 565 causes multiplexer 33 output `0000` to byte storage register 59. The output of inverter is also connected to NAND gate 486 which causes the zeros being outputted by multiplexer 33 to be loaded into byte storage register 59. The low output of flip-flop 404 to line 424 causes NAND gate 548 (FIG. 7) to go high which causes flip-flop 512 to alter its outputs during the next high to low transition of clock pulse so that its output to line 532 is high and its output to line 552 is low. At the same time, the outputs of flip-flop 404 to lines 424 and 444 go low and high, respectively because the high output on line 444 is connected to the K input thereof. Line 432 is connected to an input of NAND gate 568. When the scan start pulse on line 235 and the data timing pulse on line 234 are received by NAND gate 568 its output goes low. The output of NAND gate 568 is connected through line 570 to inverter 572, NAND gate 575 (FIG. 6), NAND gate 526, and NAND gate 486 (FIG. 8). NAND gates 486 and 526 go high which loads `0000` into the byte storage register as discussed above. The output of inverter 572 is connected to the J input of flip-flop 412, and the output of NAND gate 575 is connected to the K input of flip-flop 405. During the next high to low transition of the clock pulse, the output of flip-flop 412 to line 452 goes high and to line 432 goes low, and the output of flip-flop 405 to line 425 goes high and its output to line 445 goes low. Line 445 is connected to an input of NAND gate 526 and the low signal present thereof causes the output of NAND gate 526 to go high which in turn causes multiplexer 33 to generate a `0000` signal at its output. The output of flip-flop 405 is connected to NOR gate 505 through line 425. The high output of flip-flop 405 to line 425 causes NOR gate 505 to go low which in turn causes NAND gate 486 to go high. The high output of NAND gate 486 results in the `0000` of multiplexer 33 being loaded into byte storage register 59. Line 425 is also connected to the J input of flip-flop 405 and the K input of flip-flop 406. During the next high to low transition of the clock pulse on line 458 the output of flip-flop 405 to line 425 goes low as does the output of flip-flop 406 to line 446. Correspondingly the outputs of flip-flops 405 and 406 to lines 445 and 426 go high. Line 426 is connected to the J input of flip-flop 406 and to NAND gates 580 and 582 (FIG. 7), and the line 446 is connected to NAND gates 490 and 494 (FIG. 8). The low output of flip-flop 406 to line 446 causes NAND gates 490 and 494 to go high which in turn causes the data stored within shift register 104 (FIG. 2) to be selected as the output of multiplexer 33. The high output to line 426 causes NOR gate 505 to go low and NAND gate 486 to go high loading the selected output of multiplexer 33 into byte storage register 59. However, if comparator 184 (FIG. 4) indicates on line 195 through inverter 585 and line 587 that the data contained within shift register 104 is not above the background level, NAND gate 580 (FIG. 7) goes low because the other input to NAND gate 580 is high from line 426. This low output of NAND gate 580 is connected through line 590 to NAND gate 477 and NAND gate 526 (FIG. 8). The low output of NAND gate 580 applied to an input of NAND gate 526 causes the output of NAND gate 526 to go high which in turn causes multiplexer 33 to generate zeros at its output regardless of the selection signals on lines 203 and 204 from NAND gates 490 and 494, respectively. The low output of NAND gate 580 also causes the output of NAND gate 477 to go high which in turn causes flip-flop 400 to output high signal to line 420 and a low signal to line 440 after the next high to low transition of clock pulse as discussed above. The operation of the controller then proceeds as described above. Flip-flop 406, because line 426 is connected to its J input, during that high to low transition of the clock pulse changes its output to line 426 from high to low and its output to line 446 from low to high. If the output of flip-flop 406 to line 426 is high and the data is above the background level as indicated on line 195 from comparator 184, NAND gate 582 (FIG. 7) goes low which causes the output of NAND gate 512 to go high. The high output of NAND gate 512 applied to the J input of flip-flop 403 through line 513 causes, during the next high to low transition of the clock pulse, the output of flip-flop 403 to line 423 to go high and to line 443 to go low. The controller then operates as discussed above. If the scan start pulse is received while the output of flip-flop 400 to line 420 is high the output of NAND gate 468 to line 593 goes low. Line 593 is connected to NAND gate 575 (FIG. 6) and NAND gates 486 and 526 (FIG. 8). The low output causes all three NAND gates to go high. Thus, multiplexer 33 generates a `0000` output which is loaded into byte storage register 59 and during the next high to low transition of the clock pulse flip-flop 405 outputs a high signal to line 425 and a low signal to 445. Further, if while the output of shift register 403 to line 423 is high and the output to line 443 is low, the count in counters 500 and 502 (FIG. 9) is less than 47 as indicated by NAND gate 538, and the data is above the background, the output of AND gate 517 goes high during the next data shift pulse on line 234. The output of AND gate 517 is connected to NAND gates 555 and 597. If the signal from data redundant indicator 160 through line 168 is high NAND gate 597 goes low. The output of NAND gate 597 is connected to NAND gate 551 and inverter 600. The output of inverter 600 is connected through line 603 to the K input of flip-flop 408 (FIG. 6). Thus, flip-flops 403 and 408 flip-flop during the next high to low transition of the clock pulse. Flip-flop 408 has, after the clock pulse, its output to line 428 high and to line 448 low. If redundancy is not detected and, therefore, line 168 does not go high, the data is above the background level and the row count is less than 47, the output of flip-flop 403 to line 423 remains high and, therefore, the output of NAND gate 521 (FIG. 8) goes low when a data timing pulse is received on line 234 which causes the digital signal present in shift register 104 to be stored in byte storage register 59. The output of NAND gate 521 goes to NAND gates 486, 490 and 494. As new digital signals are moved into shift register 104 they are loaded into byte storage register 59 in series until one of the three conditions set forth above is not present. If the data redundant signal is received on line 168 and flip-flop 408 has its output to line 428 high (as discussed above). Line 428 is connected to the K input of flip-flop 407 and to NOR gate 606 (FIG. 8). The output of NOR gate 606 is connected to NAND gate 486. The high output of flip-flop 408 to NOR gate 606 through line 428 causes the NOR gate to go low which in turn causes NAND gate 486 to go high. This of course generates the load signal as discussed above. The high signal generated by flip-flop 408 is connected through line 448 to NAND gate 526. The high signal on line 448 causes NAND gate 526 to go high which in turn causes multiplexer 33 to generate a `0000` control marker at its output which is then loaded into the byte storage register. Because the K input of flip-flop 407 has a high signal applied thereto, during the next high to low transition of the clock pulse the output of flip-flop 407 to line 427 goes high and its output to line 447 goes low. At the same time the output of flip-flop 408 to line 448 goes high and its output to line 428 goes low because line 428 is also connected to the J input of flip-flop 408. NAND gate 610 (FIG. 9) is connected to counters 500 annd 502 (FIG. 9) in such a way that its output goes low when the count contained in counters 500 and 502 is equal to 46. The output of NAND gate 610 is connected through line 612 to NAND gate 614 (FIG. 6). The other input to NAND gate 614 is the data redundant (equal) pulse from comparator 127 on line 144 which has been delayed by 4 data timing pulses. The data redundant pulse is connected to NAND gate 614 through line 616. The output of NAND gate 614 is connected to AND gate 618. The other inputs to AND gate 618 are lines 427 and 234. Line 234 connects AND gate 618 to the data timing pulse. The output of AND gate 618 is connected through line 622 to the J input of flip-flop 407, the K input of flip-flop 409, and inverter 624. The output of inverter 624 is connected to line 198 which in turn connects the output of the inverter to the multiplexer unit 176 (FIGS. 3 and 4). Line 198 is also connected to NAND gates 486 and 494 (FIG. 8). Because the output of flip-flop 407 to line 427 is high and the data timing pulse on line 234 is periodically high, if either input to NAND gate 614 goes low while the data timing pulse to AND gate 618 is high the output of AND gate 618 goes high. The output of inverter 624 goes low which causes the output of NAND gates 486 and 494 to go high. This in turn causes multiplexer 33 to select the output of multiplexer 176 as its input and results in the output of a load signal to line 206. Line 198 also causes multiplexer 176 to select one of its inputs (to be discussed in detail hereinafter). The input selected by multiplexer 176 is loaded into byte storage register 59. The high output of AND gate 618 to flip-flop 407 causes it during the next high to low transition of the clock pulse to alter its output so that its output to line 427 is low and line 447 is high. The low output to line 427 causes AND gate 618 to go and remain low. Thus, the output of inverter 624 is high which selects the other input of multiplexer 176. At the same time as the output to line 427 goes low and output of flip-flop 409 to line 429 goes high and to line 449 goes low. Line 429 is connected to the K input of flip-flop 410, the J input of flip-flop 409, and input of NOR gate 606 (FIG. 8). The output of NOR gate 606 goes low and the output of NAND gate 486 goes high. Thus, the other input of multiplexer 176 is selected by inverter 624 and is loaded into byte storage register 59. The low output of flip-flop 409 is connected to NAND gate 494. During the next high to low transition of clock pulse, the output of flip-flop 410 to line 430 goes high and the output to line 450 goes low, and conversely the output of flip-flop 409 to line 429 goes low and the output to line 449 goes high. Line 450 connects flip-flop 410 to NAND gates 490 and 494 (FIG. 8). Because the output of flip-flop 410 to line 450 is low NAND gates 490 and 494 go high which causes multiplexer 33 to select the output of shift register 104 as its output. Line 430 is connected to the J input of flip-flop 410 and an input of AND gate 627. The output of AND gate 627 is connected through line 630 to an input of NOR gate 606 (FIG. 8). If the data contained within shift register 104 is above the background level, line 195 from comparator 184 is high. Since as discussed above line 430 is high, AND gate 627 goes high which causes NOR gate 606 to go low which in turn causes the data to be loaded into byte storage register 59 as discussed above. However, if the data is not above the background AND gate 627 remains low and the data is not loaded into the byte storage register 59. Line 430 connects flip-flop 410 to NAND gates 633 and 635, and AND gate 637 (FIG. 7). The other input to AND gate 637 is from NAND gate 610 (FIG. 9) through inverter 640 and line 642. If the count in counters 500 annd 502 is equal to 46 AND gate 637 is high, and during the next high to low transition of the clock pulse the output of flip-flop 413 to line 433 goes high and its output to line 453 goes low, because AND gate 637 is connected to the K input of the flip-flop. The toggling of flip-flops 413 is simultaneously with the toggling of flip-flop 410. The output of NAND gate 610 is also connected through line 612 to NAND gates 633 and 635. Line 195 is connected to an input of NAND gate 633 and to an input of NAND gate 635 through inverter 585 and line 587. If the count in counters 500 and 502 is not equal to 46 and the data is above the background, NAND gate 633 goes low which causes the output of NAND gate 512 to go high. The output of NAND gate 512 is applied through line 553 to the J input of flip-flop 403 as discussed above. The operation of the controller then proceeds as discussed above in connection with flip-flop 403. If the data is not above the background level NAND gate 635 goes low and NAND gate 477 goes high. The high output of NAND gate 477 is applied to the K input of flip-flop 400 through line 479, and the logic proceeds from that point as discussed above. If AND gate 637 is high (with the count equal to 46) and the outputs of flip-flop 413 have toggled as discussed above, the logic proceeds as follows. Line 433 is connected to an input of AND gate 645 and NAND gate 647 (FIG. 8). The other input to NAND gate 647 is the data timing pulse on line 234. The output of NAND 647 is connected through line 650 to NAND gate 490 and 494 so that, when the output of flip-flop 413 to line 433 is high and the data timing pulse is present on line 234, NAND gate 647 goes low and NAND gates 490 and 494 go high. The output of AND gate 645 is connected to the J input of flip-flop 413 and NAND gates 654 and 656 (FIG. 6) through line 658. The output of comparator 184 is connected through line 195 to NAND gate 656 and through an inverter 661 to NAND gate 654. The output of NAND gate 654 is connected through line 664 to an input of NAND gate 526 (FIG. 8) and an input of NAND gate 548 (FIG. 7). Thus, if the data is not above the level of the background, NAND gate 654 goes low which causes NAND gate 526 to go high which in turn causes multiplexer 33 to generate a `0000` output. Also flip-flop 413 toggles during next clock pulse. Line 658 is also connected to an input of NOR gate 505. The high input from line 658 to NOR gate 505 causes the NOR gate to go low which in turn causes NAND gate 486 to go high which causes the output of multiplexer 33 to be loaded into byte storage register 59. NAND gate 656 is connected through line 666 to NAND gate 559 (FIG. 7). When the next data shift pulse is received on line 234, the AND gate 645 goes high. NAND gate 656 goes low, if the data is above the background, and NAND gate 559 goes high which causes flip-flop 404 to toggle as discussed above. At the same time NOR gate 505 goes low generating and NAND gate 486 goes high, and because NAND gates 490 and 494 are high the data contained within shift register 104 is loaded into byte storage register 59. If NAND gate 654 goes low, flip-flop 412 exchanges outputs at the same time as flip-flop 413. If NAND gate 656 goes low, flip-flop 404 exchanges outputs simultaneously with flip-flop 413. The logic then proceeds from either flip-flop 412 or 404 as discussed above. As shown in FIG. 9, the scan start pulse 235 is connected through an inverter 668 to the clear and load terminals of counters 500 and 502, respectively. The data timing pulse is connected through line 670 to the count input of counter 502. The carry output of counter 502 is connected to the count inputs of counter 500. The data inputs of counter 500 are tied to ground through line 672. The three most significant data inputs of counter 502 are connected through line 674 to ground and the least significant bit put of counter 502 is connected through line 677 to a logic 1 voltage present on terminal 679. Due to the length of the scan start pulse on line 235 it was necessary within this particular environment that the least significant bit of the counter to be set to one because the first two data timing pulses would be masked by the load indication created by the begin scan pulse on line 235. The data timing pulse present on line 670 slightly precedes the data timing pulses connected to the remainder of the controller 172 in order that the counters may complete their operation prior to the address provided by counters 500 and 502 being loaded into byte storage register 59. The output of counger 502 goes through lines 682 through 685 which make up channel 208 (FIG. 4) and are connected to multiplexer 33. The two least significant bits of counter 500 are connected through lines 687 and 688 to multiplexer 33. Lines 687 and 688 comprise channel 210 (FIG. 4). The three most significant bits of output data of counter 502 on lines 683 through 685 and line 688 from counter 500 are connected to NAND gate 610 in order that NAND gate 610 goes low when the count present in counters 500 and 502 is equal to 46. Counters 500 and 502 are connected through lines 682 through 685 and line 688 to NAND gate 538 so that NAND gate 538 goes low when the count in present counters 500 and 502 is equal to 47. Thus, individualized addresses are assigned to each digital signal within a scan. As shown in FIG. 3, redundancy counter 150 includes counters 692 and 694. Line 144 from comparator 127 is connected to the count input of counter 692. The carry output of counter 692 is connected through line 697 to the count input of counter 694. The clear inputs of counters 692 and 694 are connected to the not equal output of comparator 127 through line 146. The data outputs of counter 692 and the two least significant bits of counter 694 are connected to redundancy count storage unit 164 and data redundant indicator 160. When the data redundant indicator 160 indicates that at least four successive digital signals in the data stream are redundant by causing line 168 to go high, redundancy count storage unit 164 loads the count present in counters 692 and 694. The data redundant signal on line 168 is applied to the load input of unit 164 through an inverter 700. Thus, as long as the data redundant indicator detects and determines that successive signals in the data stream are redundant the count present in counters 692 and 694 is loaded into unit 164 and appears at the output thereof. When the data redundant signal on line 168 goes low indicating that the series or train of redundant signals has terminated, unit 164 stops loading the output of counters 692 and 694 and stores the count of the counters prior to the data redundant signal on line 168 going low. Counters 692 and 694 are during the next clock pulse reset to zero. Counters 692, 694 and unit 164 receive clock pulses on line 702. Multiplexer 176 has 6 of its 8 inputs connected to the outputs of unit 164 so that multiplexer 176, which is a eight lines of input to four lines of output multiplexer, outputs the least significant bits from counter 692 when the selection signal from controller 172 on line 198 is high. When the signal on line 198 is low the data from unit 164 which represents the count of counter 694 are the two least significant bits of data. The most significant bit of data selected by line 198 is tied to a logic ` 1` present on terminal 705 and the next most significant bit of data is connected to ground through line 707. Thus, while line 198 is low the most significant bit of the output of multiplexer 176 is high, the next most significant bit is low, and the two least significant bits represent the count supplied to unit 164 from counter 694. The operation of the data compressor 20 is best summarized by reference to the flow diagrams of FIGS. 10 and 11. Assuming that the logic is in state 820 (FIG. 10) the logic flows to state 822 where a test is made to determine if a data timing pulse is resent. If the data timing pulse is not present logic flows through path 825 to state 820. If the data timing pulse is present the logic flows to state 827. In state 827 a test is made to determine if the scan start pulse which is delayed through the shift registers is present. If the scan start pulse is received, the logic enters step 829 wherein multiplexer 33 is commanded to generate a 0000 output and that output is loaded into the byte storage register 59. From step 829 the logic flows through logic path 830 to state 832. If the scan start pulse is not detected the logic flows to state 834 where the digital signal present in shift register 104 is tested to determine if it is less than or equal to the background. If the digital signal is less than or equal to the background the logic continues through logic path 836 to reenter state 820. If the digital signal in shift register 104 exceeds the background level, the logic proceeds from state 834 to step 839 where the portion of the address contained within counter 500 (FIG. 9) is loaded into byte storage register 59. The logic then goes to state 840 then on to step 841 wherein the portion of the address contained within counter 502 (FIG. 9) is loaded into byte storage register 59. The logic then proceeds to state 842 and from state 842 to step 844. In step 844 the digital signal presently stored in shift register 104 is loaded into byte storage register 59. From step 844 the logic continues to state 845, and from state 845 to state 847 wherein the presence of a data timing pulse is determined. If the data timing pulse is not present the logic returns through path 849 to state 845 and circulates through states 845 and 847 and logic path 849 until the receipt of the data timing pulse. After receipt of the data timing pulse logic flows to state 851 which tests to determine if the digital signal contained within shift register 104 is equal to or less than background level. If the data is below or equal to the background level the logic flows through path 854 to state 855. In step 855 if the row count is not equal to 47, the logic proceeds to step 857. At step 857 the multiplexer 33 is commanded to generate a `0000` output and that output is loaded into byte storage register 59. The 0000 output is, of course, a portion of the control marker. The logic returns to state 820 from step 857 and proceeds from state 820 as discussed above. If the row count is equal to 47, the logic proceeds through logic path 859 to state 860. If at state 851 the data contained within shift register 104 exceeds the background level, the logic flows to step 863. In step 863 the data contained within shift register 104 is loaded into byte storage register 59. The logic then proceeds from step 863 to state 865. At state 865 the count in counters 500 and 502 is tested to determine if the count contained therein is equal to 47. If the count is equal to 47, the logic proceeds through path 868 to state 860. On the other hand, if the count is not equal to 47 the logic proceeds from state 865 through logic path 870 to state 872. At state 872 the output of data redundant indicator 160 on line 168 (FIG. 4) is tested to determine if the data is redundant. If the data is not redundant that is the signal on line 168 is low (as discussed above) the data proceeds from state 872 through logic path 874 and returns to state 845. If the output of indicator 160 to line 168 is high the logic flows to state 875. From state 860 the logic proceeds to step 877 which causes the multiplexer to generate a `0000` output and that output is loaded into byte storage register 59. Logic flows from step 877 through logic logic path 879 to state 880. The logic continues through state 880 to state 882 wherein the receipt of a data timing pulse is determined. If the data timing pulse is not received the logic recycles through logic path 885 to state 880. After the receipt of the data timing pulse the logic enters state 887 which tests for the presence or receipt of the scan start pulse. If the scan start pulse is not received the logic cycles through path 889 to state 880. When the scan start pulse is received while the logic is in state 887 the logic proceeds to step 892. At step 892 the multiplexer 33 is commanded to generate a `0000` output and that output is loaded into byte storage register 59. Logic then flows from step 892 to state 832. From state 832 logic enters step 895 wherein the multiplexer again generates a `0000` output and that output is loaded into byte storage register 59. From step 895 the logic enters state 897 and from state 897 the logic goes to state 899. Within state 899 a test is made to determine if the digital signal in shift register 104 is less than or equal to the background level. If the signal on line 195 is low so indicating the logic flows through path 901 to step 903. At step 903 the multiplexer is again commanded to generate a `0000` output and that output is loaded into byte storage register 59 (as discussed above). From step 903 the logic goes through path 905, reenters state 820 and proceeds from state 820 as discussed above. If at state 899 the data within shift register 104 is above the background level logic flows from state 899 to step 907. At step 907 the output of shift register 104 is selected as the output of multiplexer 33 and the digital signal contained within shift register 104 is loaded into byte storage register 59. After the digital signal is loaded into byte storage register 59 the logic proceeds through logic path 910 to state 845. If the output of data redundant indicator 160 to line 168 is high and the logic is in state 872, the logic flows through state 875 to step 912 (FIG. 11). While the logic is in step 912 the multiplexer 33 generates a 0000 output which is loaded into byte storage register 59. The logic then enters state 914 and from state 914 onto state 916. Within state 916 a test is performed to determine the presence of a data timing pulse. If the data timing pulse is not present the logic proceeds through the path 919 and recycles to state 914. When the data timing pulse is detected the logic enters state 921 from state 916. Within state 921 if the count contained within counters 500 and 502 (FIG. 9) is equal to 46 the logic flows through path 923 to step 925. If the row count is not equal to 46 the logic exits state 921 and enters state 927 wherein the output of comparator 127, which has been delayed so that the digital signal determined as equal or not equal by comparator 127 is in shift register 104, is examined. If the train of redundancy signals has ended that is the digital signal within shift register 104 is not a digital signal within a train of redundant signals, the logic moves from state 927 to step 925. If the digital signal within shift register 104 is a digital signal within a train of redundant signals logic proceeds through path 927 to step 929. At step 929 the redundancy count is increased by one and the logic proceeds through path 932 to state 914. At step 925 the redundancy count is reset to zero but as discussed above this has no effect on the redundancy count stored within unit 164 (FIG. 4). From step 925 the logic goes to step 934 wherein the most significant bits of the redundancy count within unit 164 are selected as the output of multiplexer 176 and loaded into byte storage register 59 through multiplexer 33. The multiplexer 176 (FIG. 3) has its most significant bit set to a logic one and the next most significant bit set to zero which provides the remainder of the control marker. The first portion of the control marker was set in step 912. The logic then flows through state 936 to step 938 wherein the four least significant bits of the redundancy count are loaded through multiplexers 176 and 33 into byte storage register 59. From step 938 the logic goes through state 940 to state 942. At state 942 a test again is made to determine if the digital signal is equal to or below that of the background. If the data is greater than the background logic flows through path 944 to step 946 wherein the digital signal contained within shift register 104 is loaded into byte storage register 59 through multiplexer 33. After step 946 is completed, the logic moves through path 948 to state 950. If the digital signal within byte storage register 59 is below or equal to the background level, logic proceeds through path 952 from state 942 to state 950. If the row count maintained by the address counters 500 and 502 is not equal to 46 the logic proceeds from state 950 to state 954. Within state 954 a test is again made to determine if the data is less than or equal to the background level. If the data is equal to or below the background the logic flows through path 957 to step 959. At step 959 multiplexer 33 is commanded to output `0000` and that output is loaded into byte storage register 59 as the control marker and from step 959 the logic proceeds to state 820. If while the logic is in state 954 the data contained within shift register 104 is above the background, the logic flow is from state 954 to state 845. If while the logic is in state 950, the row count is equal to 46 the logic goes through path 961 to state 963. From state 963 the logic proceeds to state 964 wherein a test is made to determine if a data timing pulse is present. If the data timing pulse is not detected the logic flows through path 965 and recycles through state 963. When the data timing pulse is received the logic exits state 964 and goes to state 966. In state 966, a test is once again made to determine if the digital signal is equal to or below the background level. If the digital signal is above the background the logic proceeds to step 968 and the digital signal contained within shift register 104 is loaded through multiplexer 33 into byte storage 59. From step 968 the logic proceeds to state 860. If while the logic is in state 966, the digital signal within shift register 104 is at or below the background level, logic flows through logic path 970 to step 972. At logic step 972 the multiplexer 33 is again commanded to output a 0000 and that output is loaded into byte storage register 59. From step 972 the logic enters state 880. It should be noted that after the receipt of every data timing pulse the address generated by counters 500 and 502 which is loaded during logic states 839 and 841 is increased by one. The four bit words shown in table II are here below derived from the raw data of table I utilizing the logic diagrams of FIGS. 10 and 11. Assuming that logic is cycling through states 820 and 822 when the data timing pulse is received the logic continues to state 822 where the scan start pulse is received. Before entering state 820 byte number 1,000, is generated by multiplexer 33 in either step 903, step 857, or step 959. After the scan start pulse is received, the logic moves to step 829. At state 829 to 0000 of byte number 2 is generated by multiplexer 33. The logic then proceeds through state 832 to step 895 wherein the 0000 of byte number 3 is generated by multiplexer 33. After step 895 the logic goes through state 897 to state 899. In this example the background level has been set at 0000 and therefore anything above 0000 will be passed through the data compressor 20 to the byte storage register 59. At state 899 the first bit of raw data "D" is tested to determine if it is above the background level. Therefore, the logic proceeds to step 907 and "D" which is present at the output of shift register 104 is selected as the output of multiplexer 33. This is byte number 4. From step 907 the logic proceeds through state 845 to state 847. After the data timing pulse is received the logic moves from state 847 to state 851 wherein the data in shift register 104 is tested to determine if it is above the background. Because the data is not `0000` logic proceeds to step 863 wherein the data contained within shift register 104, "F", `1111`, is selected as the output of multiplexer 33 and a load signal is sent. This is byte number 5 of table II. Because the row count is not equal to 47, the logic proceeds through state 865 to state 872. Byte number 5 represents the first of a train of redundant signals and four such signals already having been detected the logic will continue through state 872 and state 875 to step 912. In step 912 byte number 6, `0000`, is generated by multiplexer 33 and the proper load signal is sent. The logic then continues through state 814 to state 816 and upon the receipt of a data timing pulse to state 921. Because the row count is not equal to 47, the logic continues through state 921 to state 927 because of the train of pulses is still being received the logic cycles through step 929, state 914, state 916, state 921 and state 927 until the last "F" i.e. the comparator 127 detects the last "F" and the `5` are not redundant. In the example the difference allowable between adjacent digital signals within the data stream to determine redundancy is `0000`. Thus, in the example the signals in order to be redundant must be equal. After the last redundant signal is detected and such detection is prior to the row count equaling 46, the logic proceeds from state 927 through step 934, state 936, and step 938. Thus, the remainder of control marker that is a 1 followed by a 0 and the two most significant bits of the redundancy count are selected as the output of multiplexer 33. This is byte number 7 in table II. In step 938, byte number 8 which is the four least significant bits of the redundancy count is selected as the output of multiplexer 33. The redundancy count is equal to 21. The logic proceeds from step 938 through state 940 to state 942 wherein `5` is compared to the background level to determine if it is above the background level and, because it is, the logic proceeds to step 946 where `5` is selected as the output of multiplexer 33. This `5` is loaded into byte storage register 59 and is byte number 9, `0101`, of table II. The logic then proceeds from step 946 through state 950 (because the row count is not equal to 46) to state 954 wherein the test on digital signal which is equal to the `5` stored within shift register 104 is compared to the background. Since `5` is above the background, the logic proceeds through state 845 to state 847 and awaits a data timing pulse which indicates that a new digital signal is present in shift register 104. After the data timing pulse is received logic proceeds to state 851 wherein the data is tested against the background. Because this data is a digital signal `0` the logic proceeds to step 855 through state 857 (because the row count is not equal to 47). At state 855 the multiplexer 33 generates a `0000` output which is byte number 10 of table II. The logic then proceeds through state 822 and awaits a data timing pulse and because the scan start pulse is not received at this time the logic proceeds through state 827 to state 834. Since the next bit of data is also a digital signal "0" the 0000 logic proceeds to state 820 and continues to recycle through this loop until the presence of the next signal which is not a `0` digital signal is detected. When, `7` is present in shift register 104 the logic then proceeds through step 839 wherein byte number 11 of table II is loaded, and through state 840 to step 841 wherein byte number 12 is selected as the output of multiplexer 33. The address represented by byte numbers 11 and 12 is 31 which is the location of the `7` within the scan. Because the most significant bit of byte number 11 is `0` during later reconstruction these two bytes after the first part of the control marker i.e., byte number 10 which is `0000`, is understood as an address. Byte numbers 7 and 8 are understood to be a redundancy count because the most significant bit of byte number 7 after the first part of the control marker i.e. byte number 6 which `000` of table II is a logic "1". The logic proceeds from step 841 through state 842 on to step 844 wherein the byte number 13 i.e. the digital signal "`, `0111`, is selected as the output of multiplexer 33. The logic then proceeds through state 845 to state 847 wherein after a data timing pulse is detected the logic proceeds to state 851. Because the data is above background level, the logic goes from state 851 to step 863 wherein the output of shift register 104 is selected as the output of multiplexer 33. This is byte number 14 of table Ii and is an `8` represented digitally as `1000`. Logic then proceeds through state 865 because the row count is not equal to 47 to state 872. Because redundancy is not detected, the logic proceeds to state 847 through state 845. Byte number 15, `1010` which is a digital signal "A", is loaded in a similar manner. When the next `0000` digital signal is received the logic goes from state 851 through state 855 to step 857 wherein byte number 16, `0000`, is generated by multiplexer 33. From state 855 the logic flows to state 822 through state 820, and as data timing pulses are received through state 827 and 834 and returning to state 820 because the digital signals are `0000`. Upon receipt of the next scan start pulse the logic flows from state 827 to step 829 and byte number 17, `0000`, is generated within multiplexer 33. From step 829 the logic proceeds to step 895 through state 832 and in step 895 byte number 18, `0000`, is generated within multiplexer 33. If the logic is initially in state 880 when the scan start pulse for the raw data in table I is received, the logic would proceed from state 887 to step 892. Byte number 1, `0000`, loaded prior to entry into state 880 in either step 877 or 972. In step 892 byte number 2, `0000`, of table II is generated within multiplexer 33. The logic then proceeds to step 832 and from step 832 through the flow diagrams of FIGS. 10 and 11 as discussed above. It should also be pointed out that if the system has been reset and this is the first scan of data from the data lift, the entry point into the logic is through step 860 which is equivalent to flip-flop 404 of FIG. 6. After reset the logic enters state 860 and proceeds to load a first byte which is `0000` in step 877. Thereafter the logic continues as discussed above. The row counter is reset to one when a scan start pulse is received and the row counter is incremented by one each occasion a data timing pulse is received. These steps have not been incorporated within the flow diagrams of FIG. 10 and 11. Also, the redundancy count would be equal to four prior to entry in the loop fo which step 929 is a part. In summary, at the start of each scan the scan start pulse resets the address counters contained within the controller 172 of the data compressor 20. The controller provides selection signals to 2 multiplexers, 33 and 176, of the data compressor 20. The digital signal selected by the controller 172 which appears as the output of multiplexer 33 is the output of the data compressor. A load signal is also provided to the apparatus accepting the output of the data compressor in order that it may load the output of the multiplexer 33 at the proper time. A redundancy counter counts the output of a comparing system which determines if adjacent digital signals in a data stream are identical (or represent a cluster of closely related signals to the redundant signal of the train). If 4 or more signals are determined to be redundant the count within the redundancy counter is stored within a shift register until after the last signal in the train of redundant signals is received. Redundancy count is then selected by the controller as the output of multiplexer 33. A primary signal which in the above example was `0000` is selected as the digital signal which is to be removed from the data stream and replaced by the address within each scan of data for the next signal which is not of the primary signal. Thus, in the example all of the `0000` signals are replaced by a control marker which in the example is the primary signal `0000` and the address of the next digital signal in the data stream which is not `0000`. Further, a group of signals which are closely associated with the primary signal i.e. the difference in magnitude between a primary signal and the digital signals within the group can also be eliminated from the data stream and replaced by the address of the next signal which is not a primary signal nor one of the group of closely related signals. In the exmaple the group of closely associated signals is generally referred to as the background level and represents those signals closely related in magnitude to the `0000`, for example, `0001`, `0010`, etc. Control markers are substituted for the digital signals eliminated from the data stream. Having described the invention in connection with certain specific embodiments thereof, it is to be understood that further modifications may now suggest themselves to those skilled in the art and it is intended to cover such modifications as fall within the scope of the appended claims.

A data compressor with a plurality of serially connected shift registers compressing digital signals received from a data lift for transfer to a storage device which operates at a slower rate than the data lift generates digital signals. The data compressor eliminates from the data stream one of the frequently generated digital signals or a closely related group thereof and substitutes an address of the next digital signal which is not of the group being eliminated. Further, the data compressor eliminates trains of redundant signals which are longer than a certain minimum number of signals and substitutes a count which represents the number of redundant signals within each train therefor. The data compressor also inerts control markers into the data stream to identify the redundancy counts and the addresses which have been inserted therein. A logic sequencer controller is provided within the video data compressor controlling the elimination of data from the data stream and the insertion of the control markers, addresses and redundancy count therein.

FIELD OF THE INVENTION The present application relates to the diagnostic imaging arts. It finds particular application in the context of patient safety and associated improved scanning performance (in terms of radio frequency (RF) duty cycle) and will be described with particular reference thereto. Furthermore, the estimation and suppression of local specific energy absorption rate (SAR) hot spots in connection with high field magnetic resonance imaging (MRI). It is to be appreciated, however, that it is also applicable to optimization and processing of other information, and is not necessarily limited to the aforementioned applications. BACKGROUND OF THE INVENTION For many MR applications at higher field strengths, the local SAR is a limiting factor. The SAR deposition increases with higher field strength and limits the RF power, duty cycle, and flip angles usable, leading to a lengthening of scan acquisition time to meet designated SAR limits. For a single transmitter system, the SAR was relatively easy to calculate, as all antenna elements transmitted with the same amplitude, and a fixed phase shift between them. Furthermore, the RF pulse shapes required for the experiments are known and are stored in a shape library, associated with their SAR. With the advent of multi-transmit systems where each coil element has the potential to independently transmit its own amplitude and phase, SAR must be calculated on a per channel basis also considering the parallel RF transmission pulses, which can only be calculated based on additional information, for example, B 1 maps, and are thus experiment/patient specific. RF safety is a prerequisite for in vivo parallel transmission MRI scans, that is, scanning within SAR limits using multi-channel RF transmit coils must be guaranteed. Scans cannot be started unless they are “SAR safe.” In an MR system with multiple transmit channels, SAR reduced RF pulses can be calculated by incorporating electrical field information into an RF pulse design. In the past, methods have been used that construct RF pulses in consideration of known SAR hotspots that are common to every individual (e.g., the eyes). This is generally not sufficient for whole body imaging, as SAR hotspots can vary in both position and magnitude from patient to patient, and from RF pulse to RF pulse. Thus, an RF pulse sequence that limits SAR to acceptable levels in one patient may not be so limiting with respect to another patient. Moreover, RF sequences that accommodate a known static hotspot may inadvertently exacerbate unknown, patient specific hotspots at other locations. One possible solution is to develop a worst-case scenario estimation of SAR that would be safe for all patients. This solution, however, would limit the allowed RF duty cycle so much that the MRI system would become seriously compromised for use in conjunction with in vivo parallel transmission scans. The ability to tailor a SAR calculation to the patient would be more beneficial than using a blanket scenario or known term for all patients. One reason in particular that RF sequences are currently not constructed on a patient-by-patient basis, is that for clinically relevant spatially RF pulses (e.g. local excitation or zoom imaging), parallel transmission systems that can accelerate these kinds of RF pulses (TxSENSE) are required. For an RF sequence, an underlying prerequisite is the availability to efficiently estimate the SAR. Moreover, availability of patient related E-fields and patient position are highly desirable for an accurate SAR estimation (including global and local SAR values and optionally a SAR map.) Field data obtained by simulations differ to some degree from the actual fields in the scanner. Use of bio-mesh models for E-field simulations instead of the actual patient leads to a systematic error that is difficult to characterize. For a standard, single channel birdcage coil RF transmit assembly, the RF waveforms are identical for every Tx coil element and only a phase increment (e.g. 45° for 8 elements) exists. For multiple Tx coil elements, the calculation is more complex, as each channel may have a different but static amplitude and phase. In more complex scans, such as for 2D/3D spatially selective pulses, each channel may have dynamically changing amplitudes and phases. In order to calculate all SAR types as specified in the standard (local and global) and optionally a SAR map of a patient for a multi-channel RF transmit system, (e.g., eight transmit channels) the system performs a high number of calculations (e.g. TeraFLOPs): as high as 10 10 calculations or more, depending on the resolution of the model and cells used for the calculation. This process would take several minutes and cannot practically be carried out in real time as the patient waits inside the scanner for the actual diagnostic scan to begin. The present application provides a new and improved magnetic resonance system, which overcomes the above-referenced problems and others. SUMMARY OF THE INVENTION In accordance with one aspect, a magnetic resonance system is provided. A main magnet generates a substantially uniform main magnetic field in an examination region. A radio frequency assembly induces magnetic resonance in selected dipoles of a subject in the examination region, and receives the magnetic resonance. A specific energy absorption rate calculation processor calculates a specific energy absorption rate and determines local specific energy absorption rate hotspots. A sequence controller designs an RF excitation pulse that accounts for the local specific energy absorption rate hotspots and keeps energy delivered to the hotspots under acceptable levels. In accordance with another aspect, a magnetic resonance system is provided. A main magnet generates a substantially uniform main magnetic field in an examination region. A radio frequency assembly induces magnetic resonance in selected dipoles of a subject in the examination region, and receives the magnetic resonance. A specific energy absorption rate calculation processor calculates a specific energy absorption rate and determines local specific energy absorption rate hotspots. A graphics card processes non-graphics information in parallel. In accordance with another aspect, a method of magnetic resonance is provided. A substantially uniform main magnetic field is generated in an examination region. Magnetic resonance is induced in selected dipoles of a subject in the examination region, and the magnetic resonance is received. A position of the subject within the examination region is determined. A specific energy absorption rate is calculated. A globally safe RF pulse waveform that accounts for the calculated specific energy absorption rate is calculated. This may be done iteratively, if e.g., the first RF pulse estimate does not meet the SAR limits, or other system parameters, like the T R (repetition time) are prolonged. One advantage is the ability to efficiently verify that a parallel transmission scan does not violate existing FDA or International Electrotechnical Commission limits. Another advantage lies in increased calculation speed of SAR values, hotspots, and spatial SAR distribution. Another advantage lies in the ability to customize the SAR calculation to individual patients. Another advantage lies in the ability to create an optimal RF pulse sequence based on a patient's SAR profile. Another advantage lies in the ability to determine specific information, such as E-fields and patient positions, on a patient-by-patient basis. Another advantage lies in the ability to detect anomalies or surgical implants for SAR model adaptation. Still further advantages of the present invention will be appreciated to those of ordinary skill in the art upon reading and understand the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. FIG. 1 is a diagrammatic illustration of a magnetic resonance imaging apparatus in accordance with the present application; FIG. 2 includes exemplary waveforms for PUC sampling during RF excitation; FIG. 3 is a graph of dependence of hot spot suppression on an empirically determined weighting factor; FIG. 4 is a comparison of alternate methods that consider less than all of the available information with an embodiment that considers all of the information; FIG. 5 is a comparison of a worst-case scenario method of calculating SAR to the embodiment that considers all of the information. DETAILED DESCRIPTION OF EMBODIMENTS With reference to FIG. 1 , a magnetic resonance scanner 10 is illustrated as a closed bore system that includes a solenoidal main magnet assembly 12 , although open and other magnet configurations are also contemplated. The main magnet assembly 12 produces a substantially constant main magnetic field B 0 oriented along a horizontal axis of an imaging region. It is to be understood that other magnet arrangements, such as vertical, and other configurations are also contemplated. The main magnet 12 in a bore type system may typically have a field strength of around 0.5 T to 7.0 T or more. A gradient coil assembly 14 produces magnetic field gradients in the imaging region for spatially encoding the main magnetic field. Preferably, the magnetic field gradient coil assembly 14 includes coil segments configured to produce magnetic field gradient pulses in three orthogonal directions, typically longitudinal or z, transverse or x, and vertical or y directions. A radio frequency coil assembly 16 , including n coil elements 16 1 , 16 2 , . . . 16 n , generates radio frequency pulses for exciting resonance in dipoles of the subject. The signals that the radio frequency coil assembly 16 transmits are commonly known as the B 1 field. The radio frequency coil assembly 16 also serves to detect resonance signals emanating from the imaging region. The illustrated radio frequency coil assembly 16 is a send/receive coil that images the entire imaging region, however, local send/receive coils, local dedicated receive coils, or dedicated transmit coils are also contemplated. In one embodiment, the radio frequency coil assembly 16 includes an 8 channel transmit/receive antenna. Gradient pulse amplifiers 18 deliver controlled electrical currents to the magnetic field gradient assembly 14 to produce selected magnetic field gradients. A radio frequency transmitter array 20 , including n transmitters 20 1 , 20 2 , . . . 20 n , preferably digital, applies radio frequency pulses or pulse packets to the radio frequency coil assembly 16 to excite selected resonance. In the illustrated embodiment, the number of coil elements and the number of transmitters are the same. However, more than one coil element can be associated with each transmit channel. A radio frequency receiver array 22 , including n receivers 22 1 , 22 2 , . . . 22 n in the illustrated embodiment, is coupled to the coil assembly 16 or a separate receive coil array to receive and demodulate the induced resonance signals. To acquire resonance imaging data of a subject, the subject is placed inside the imaging region. A sequence controller 24 communicates with the gradient amplifiers 18 and the radio frequency transmitters 20 1 , 20 2 , . . . 20 n to excite and manipulate magnetic resonance in the region of interest. The sequence controller 24 , for example, produces selected repeated echo steady-state, or other resonance sequences, spatially encodes such resonances, selectively manipulates or spoils resonances, or otherwise generates selected magnetic resonance signals characteristic of the subject. The generated resonance signals are detected by the RF coil assembly 16 or local coil assembly (not shown), communicated to the radio frequency receiver 22 , demodulated, and stored in a k-space memory 26 . The imaging data is reconstructed by a reconstruction processor 28 to produce one or more image representations that are stored in an image memory 30 . In one suitable embodiment, the reconstruction processor 28 performs an inverse Fourier transform reconstruction. The resultant image representation(s) is processed by a video processor 32 and displayed on a user interface 34 equipped with a human readable display. The interface 34 is preferably a personal computer or workstation. Rather than producing a video image, the image representation can be processed by a printer driver and printed, transmitted over a computer network or the Internet, or the like. Preferably, the user interface 34 also allows a technician or other operator to communicate with the sequence controller 24 to select magnetic resonance imaging sequences, modify imaging sequences, execute imaging sequences, and so forth. At the interface 34 , the user can select a SAR model, and all or part of the remaining parameters can be determined with user interaction and feedback. A specific energy absorption rate (SAR) processor 36 calculates SAR for portions of the subject within the coil assembly 16 . In one embodiment, the SAR calculation processor 36 creates a SAR map of the whole body that includes regions of increased SAR or hotspots. For a standard scan in which there is a constant change of amplitude and of phase for standard RF pulses, SAR can be calculated very quickly as only the phase/amplitude relation is relevant. Thus, the calculation of a single RF sample is sufficient as the amplitude/phase relation does not change the pulse. A standard scan could be implemented by typical MRI systems and parallel transmission systems using constant phases and amplitudes. Provided that the RF field inside the subject responds linearly to the currents driving the field, the SAR can be expressed in a quadratic form in the pulse samples b†Qb, where † denotes the conjugate transpose, b is the RF waveform sample, and Q is a Hermitian positive definite matrix resulting from the solution of Maxwell's equations and corresponding to a specific subject volume. The SAR map is created by considering several inputs, including trajectory, B 1 field maps, target excitation pattern, and a global Q matrix. Existing SAR optimal algorithms typically only constrain a specific known static local region, such as the eyes. As mentioned previously, this is inadequate for full body imaging because other hotspots that vary by subject may be present. Statistically constraining a spatial region in which a hotspot occurs may result in new hotspots at other locations. A memory 35 can store pre-calculated data of one or multiple patient positions to prevent re-calculation of the Q-matrices when unnecessary. Additionally, the memory 35 can store SAR values so that SAR need not be calculated repetitively for identical pulses. A unique ID can be used to identify the pulses. For local SAR calculation, the SAR of each volume element of a patient model is averaged until the desired mass is reached. The SAR value for a volume element is indicative of the SAR along the edge of the volume element, and the data is interpolated to acquire the SAR value at the center of each voxel. Some of the information can be pre-calculated and stored in a look up table (LUT) 37 . Scanner specific information such as electric fields and B 1 field maps are stored in the LUT 37 . An appropriate starting bio-mesh can be selected from a body model memory of the LUT 37 by knowing the patient's height, weight, sex, and position in the MR scanner. While the height, sex, and weight can be entered by an operator before the scan, the patient position is determined by a subject position processor 39 . One way to obtain patient position and refine the patient model is to use a moving bed approach. Images are acquired while the patient is being moved into the bore of the scanner, resulting in a low-resolution 3D volume data set. Alternately, a short pre-scan could be performed once the patient is in the final position in the bore. This data can be segmented, for example, by thresholding or some other processing means. Next, the position of the patient can be obtained by correlation methods with existing models, for example, from transverse slices of the patient or the detection of landmarks. Also, the patient volume and size could be estimated. Anomalies such as implants or missing organs can also be detected. In this way, the starting body model is customized to the current patient. Once the patient position has been determined, the SAR calculation processor 36 consults the LUT 37 to get the corresponding E-field data as a function of the input parameters (weight, sex, position, etc.) using an appropriate combination thereof. If deviation from all models stored in the LUT 37 is too large, then a very conservative SAR estimation could be used. In the case of implants for a particular scan, appropriate SAR limits for the device can be retrieved from the LUT 37 . After the initial position has been determined, any table movement can be monitored by the subject position processor 39 and can be used to accurately determine the new position of the patient. In an alternate embodiment, a coarsely segmented body model can be obtained from the moving bed imaging data or pre-scan, which can be used for a fast adaptation of existing E-fields of similar patients or a fast estimation of e.g. a homogeneous model. Use of a homogenous model introduces inaccuracies in conductivity and permittivity that are relatively small. The differences between using data from a homogenous model and actual data are tolerable, such that use of a model is a viable alternative. In another alternate embodiment, patient position can be determined by using pickup coils (PUCs). Each transmit element of a multi channel transmit coil is equipped with a PUC for monitoring current in each element to ensure patient safety and facilitate system adjustment. In general, the patient's presence influences the coil's properties. Thus, the loading of the RF coil elements changes during the movement of the patient through the magnet bore. This movement can be detected as a phase change. This can be translated to an approximate position of the patient in the MR system. This is possible because the currents in the coil elements are sampled during the RF pulses, as shown in FIG. 2 . Exemplary RF and gradient waveforms are provided. The dotted lines represent the RF excitation waveforms, the dashed lines represent the MR signal sampling waveforms, and the solid lines represent the PUC sampling waveform. Additionally, the PUCs can be used to sense abnormal currents in the RF coil channels and initiate a scan termination if safety parameters are exceeded. Once the SAR map is created, the sequence controller 24 designs an RF pulse sequence that is tailored to the present subject's SAR map. This could also be done by a host reconstructor or a separate graphics card that calculates RF pulses. The sequence controller 24 introduces weighting factors that specify a trade-off between different hotspot regions and the global SAR. For instance, depending of the spatial SAR distribution of an RF pulse that is optimal with respect to global SAR, hotspot reduction is possible via Q 1 =Q global Σq i Q critical — region(i) , where Q 1 is the modified Q-matrix, Q global is the original global Q-matrix, q i is a weighting factor, and Q critical — region(i) is a Q-matrix of a volume immediately around the hotspot (e.g. a 3×3×3 voxel volume). The sequence controller 24 iteratively processes the SAR map to find the best weighting factors q i to satisfy existing SAR limits and to decrease the most limiting SAR value. More specifically, the sequence controller 24 directs the gradient assembly 14 and the RF assembly 16 to apply the newly designed RF pulse sequence. The SAR calculation processor 36 then recalculates the SAR map. Positions of local hotspots are once again determined. Next, the sequence controller 24 volume averages the Q-matrices (Q critical — region(i) ) of the hotspots, and weights them. The weighting factors have been determined empirically based on the distance (z) of the hotspot from the isocenter of the magnet. With reference now to FIG. 3 , the troughs of the curves represent the optimal weighting factor for that distance. Curve 40 represents hotspot suppression with z=20 cm. Curve 42 represents hotspot suppression with z=40 cm. Curve 44 represents hotspot suppression with z=60 cm. Curve 46 represents hotspot suppression with z=80 cm. Lastly, curve 48 represents hotspot suppression with z=100 cm. The weighted, volume averaged Q-matrices are added to the global Q-matrix. The radius of the spatial averaging around each hotspot, the hotspot positions, the local Q-matrices, and the selected weighting factors are all taken into consideration when recalculating Q 1 , the updated global Q-matrix. Once the Q-matrix has been updated, the sequence controller 24 designs a new, SAR optimized RF pulse sequence based on the updated Q-matrix Q 1 . As before, lower SAR values are obtained at the critical regions. The sequence controller 24 and the SAR calculation processor 36 can apply one or more of the above steps iteratively until SAR converges to a minimum value at the hotspots, or alternatively, until a desired safe SAR level is reached. In some cases, it might not be necessary to apply the iterations until SAR converges to a minimum if SAR reaches a safe level before it converges. Alternatively, the repetition time T R can also be prolonged, or the flip angle can be reduced, or a combination of the two. Also, the RF pulse can be re-optimized if the patient is moved. This iterative process is computationally intense, requiring a large amount of data processing capacity each time the global Q-matrix is updated. With existing systems, each iteration could take several minutes, which is impractical with a patient waiting in the scanner. Each Q-matrix calculation accounts for the correct amplitude information and the correct phase information for each channel involved. In one embodiment, each voxel of the body is calculated separately, giving the highest resolution possible. The average amount of voxels in a bio-mesh is on the order of 750,000 for a voxel size of 5 mm. When phase, and amplitude information is processed for each RF channel's effect on each voxel, a high number of calculations (e.g. TeraFLOPs) are required to calculate the global and local SAR and to produce a SAR map. As mentioned previously, one embodiment includes an RF assembly 16 with eight channels, but it is to be understood that assemblies with more channels are possible, with any arbitrary combination of channels operating at any given time. SAR is calculated for these situations accordingly. In the embodiment of FIG. 1 , the SAR calculation processor 36 delegates the task to a sub-processor 38 , such as a high-performance graphics card. The sub-processor 38 can be located in the SAR calculation processor 36 itself, in a host computer, or in a spectrometer. Since the SAR calculations of the individual voxels are not dependant on one another, they do not have to be processed one after another, that is, they can be processed in parallel. The sub-processor 38 such as a graphics card offers many parallel processing channels (e.g. 128, 256 etc.) to speed up the calculation of the SAR. For example, by using a graphics card with 128 processing channels, calculation of the SAR was accelerated by a factor of 100 over using a 3 GHz processor alone to calculate the SAR. Resultantly, calculation of the SAR of an RF pulse for a single biomesh can be performed in seconds instead of minutes. This allows the iterative process of converging SAR hotspots to minima described above to be performed in a practically applicable amount of time. In one embodiment, if the sub-processor 38 is unavailable (for example, if the graphics card is broken) then the SAR calculation processor 36 can complete the calculation so that scanning is still possible. In an alternate embodiment, voxels can be grouped by their proximity and averaged, reducing the number of volume elements from roughly 750,000 to, for example, 100,000. This further reduces calculation time of the SAR, but sacrifices some resolution and accuracy in the calculated SAR maps. As a consequence, an extra safety margin is added to obtain the estimated SAR values for a scan. In another alternate embodiment, amplitude and channel information is considered, but phase information is not. This also speeds up the calculations, but calculates a less accurate SAR map, erring on the side of caution. The SAR values are overestimated in this embodiment. In another alternate embodiment, amplitudes are set to maximum in each corresponding channel. This method again cuts the amount of calculations down, since only the maximum amplitude for each channel is considered, but sacrifices the quality of the resultant calculations, again, erring on the side of caution. In another alternate embodiment, a worst case scenario embodiment, only the maximum amplitude, regardless of the channel is considered. This results in only a coarse estimation of the actual SAR map. FIGS. 4 and 5 illustrate some of the alternate embodiments that consider less than all the information compared to the embodiment that considers all of the available information. In FIG. 4 , curve 50 represents the embodiment that considers correct amplitudes, but no phase. Curve 52 represents the embodiment that considers maximum amplitudes in the correct channels. Curve 54 represents the worst case scenario embodiment, where not even channel information is considered. The curves 50 , 52 , 54 depict the ratio of calculated to actual SAR as a function of the reduction factor. As can be seen, as more information is considered, the closer the estimation of SAR comes to the actual SAR. If these error ratios are acceptable, however, calculation time can be saved by using one of the alternate methods. FIG. 5 illustrates calculations made using the worst case scenario method 58 compared against the actual calculations 60 . FIG. 5 is the position dependence of the local trunk SAR of an 8-channel body coil emulating a standard one-channel body coil, with a phase of 45° and an amplitude of one on all channels. It is evident that the worst case scenario method greatly overestimates SAR, especially in the midsection of the patient, leading to less accurate calculations of SAR. Also evident is the dependence of SAR on position. In another alternate embodiment, the SAR calculation processor 36 , sub-processor 38 or any other components can be located on a remote server. Multiple clients can be served simultaneously by the server. When multiple requests for SAR values appear concurrently, the server can prioritize them based on the order of arrival, or based on other priorities. The invention has been described with reference to the preferred embodiments. Modifications and alterations may occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

In a method and apparatus to enable increased RF duty cycle in high field MR scans, a specific energy absorption rate (SAR) calculation processor calculates the local and global SAR or even a spatial SAR map. By incorporating additional information as, e.g. patient position, the SAR calculation accuracy can be increased as well as by using more patient specific pre-calculated information (e.g. based on different bio meshes), the so called Q-matrices. A sequence controller maybe provided to create a global SAR optimal RF pulse. After the optimal RF pulse is applied, the SAR and its spatial distribution are determined. SAR hotspots are also determined. Q-matrices within an appropriate radius around the hotspots are averaged and added to a global Q-matrix in a weighted fashion. After the global Q-matrix is updated, a new optimal RF pulse is created.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application is a divisional application of U.S. application Ser. No. 11/466,306, filed on Aug. 22, 2006, which claims benefit of U.S. Provisional Application Ser. No. 60/710,574, filed on Aug. 23, 2005, and entitled “High Accuracy GIS System,” the disclosures of which is incorporated herein by reference. BACKGROUND [0002] A high accuracy survey-grade geographic information system (GIS) would need to transform distinct isolated land surveys, which could be separated by several miles, onto a common coordinate system that does not distort or scale the dimensions of those surveys. Furthermore, a high accuracy survey-grade GIS would have to position the transformed surveys relative to each other at the same distances that would be measured between them on the ground using transit and tape or electronic distance measure (EDM). Because the purpose of a high accuracy survey-grade GIS is to transform separate isolated surveys onto a common coordinate system in such a manner as to produce in essence one unified survey, in order to be survey-grade the relative positions of the transformed surveys would have to meet the relative positional accuracy standards for ALTA/ACSM land title surveys as adopted by the American Land Title Association and the National Society of Professional Surveyors, which is a member organization of the American Congress on Surveying and Mapping. Those standards state: “‘Relative Positional Accuracy’ means the value expressed in feet or meters that represents the uncertainty due to random errors in measurements in the location of any point on a survey relative to any other point on the same survey at the 95 percent confidence level . . . . [The] Allowable Relative Positional Accuracy for Measurements Controlling Land Boundaries on ALTA/ACSM Land Title Surveys [is] 0.07 feet (or 20 mm)+50 ppm.” [0003] Global Navigation Satellite Systems (GNSS), such as the United States Department of Defense's Global Navigation System (GPS), afford land surveyors the prospect of relating all their surveys to a common spatial reference system based on geodetic latitudes, longitudes, and ellipsoid heights. In theory, the ability to relate all surveys to a common coordinate system opens the door to possible realization of a high accuracy survey-grade GIS. In practice, the hurdles and multiple problems associated with actually designing and implementing a high accuracy survey-grade GIS that can feasibly operate within a survey firm while meeting the accuracy standards leads one to conclude that such a complex system of technology married to the human management of average surveyors and field crews is at best improbable. In the past several years articles have been written and conferences have taken place that address the problem of integrating the requisite high accuracy requirements demanded of land surveys with the far less accurate spatial demands historically placed on the GIS community. The discussions have been largely talk and theorizing with no solutions proposed. [0004] Land surveyors produce many different types of surveys or plats of survey, which are paper plots or scale drawings depicting the dimensions and orientation of a parcel of land in accordance with a written deed or legal description. A survey can include a depiction of physical man made improvements, as well as natural features, such as the topography of the terrain and vegetation. Surveyors obtain the information necessary to produce a survey by using equipment designed to measure the location of individual points on the surface of the earth. [0005] The types of measurement equipment used may include electronic total stations and or dual frequency differential GNSS antennas and receivers that generate positional coordinates by receiving signals from U.S. Department of Defense satellites, Russian Glonass satellites, and in the future a European satellite system called Galileo. For example, if a surveyor needs to locate and dimension a roadway, he will be required to measure the relative location of a sufficient number of individual points on the edge of the road so that when those points are connected by lines or curves, the result is a correct scale rendering of the road. [0006] As points are being measured in the field, the coordinates representing those locations may be stored in a data collector mounted to, connected to or in communication with the measuring instrument. Often, the data collected for a single point location consists of five fields within an electronic or computer point database. Those five fields, in the order most commonly used, are: 1) Point Number, often an arbitrary number automatically generated at the time of measurement and usually consecutively sequenced from the last point number used, it is used to distinguish one point from another, but may also be an assigned identifier; 2) Northing, the Y component in a three dimensional Cartesian coordinate system; 3) Easting, the X coordinate in a three dimensional Cartesian coordinate system; 4) Elevation, the Z coordinate in a three dimensional Cartesian coordinate system; 5) Point description, a code which uniquely identifies what is being located, whether it be a building corner or edge of asphalt. Other information may also be collected simultaneously or contemporaneously with these five data elements. [0007] The electronic field measured point data may then be transferred from the data collector to an office computer of the survey company or firm and then may be imported into survey software that may be used to create a computer aided drafting (CAD) drawing that has an associated point data base with the five or more data fields as described. The CAD software may then be used to connect the dots between the points in the associated point database, based on classifications that may be included in the point description field and on input from the field crew, and may also be used to produce a plat or record of survey which may be printed out on a plotter. CAD drawings and associated point databases may be kept and managed within project folders that may include unique project numbers used to distinguish one survey from another. [0008] The survey and description of real property in the United States has historically proceeded under the fiction that the world is flat. With very few exceptions, written legal or deed descriptions for parcels of land in the United States are based on distances that are measured on the ground in the sense that the distance between two points is measured using a tape or chain held level. Indeed this is the means by which the public lands of the United States have been surveyed and sold off to private owners beginning with the first Land Ordinance passed on May 20, 1785 by the Continental Congress: “An Ordinance for Ascertaining the Mode of Disposing of Lands in the Western Territory. Be it ordained by the United States in Congress assembled, that the territory ceded by individual states to the United States, which had been purchased of the Indian habitants, shall be disposed of in the following manner: . . . . The lines shall be measured with a chain; . . . ” Legal descriptions for real property may reference adjacent or nearby land or legal features, which may be measurable on the face of the Earth as well. In the interpretation of written legal descriptions to derive a drawing or survey plat of a parcel, it is conventional to derive the location of parcel boundaries with respect to a planar or flat two dimensional Cartesian coordinate system (for the vast majority of surveys this is mandatory because almost all legal descriptions preserve a chain of title from the time they were originally conveyed by the United States). Thus, drawings or other interpretations of property descriptions are drafted from the reference of measurements upon the ground. [0009] It might be of enormous benefit to a surveyor to be able to spatially relate, with high accuracy, all surveys he or she produced. One of the primary benefits is illustrated in FIG. 1 . Depicted are four parcels of land, parcels A, B, C and D, showing the parcels' actual physical spatial relationship as measured on the ground. If surveys are produced for Parcels A, B, and C, and if the relative locations of those surveys are known with sufficient accuracy, then the amount of time and effort required to survey Parcel D could be dramatically reduced because four of the property lines of Parcel D are defined by property lines belonging to Parcels A, B, and C. The area over which a given survey or legal description for real property is likely to have influence over the location of adjacent or nearby boundaries of other parcels will generally not exceed several square miles. Of course not being able to predict which combination of surveys will have a bearing on future surveys it would be necessary to be able to spatially relate all surveys produced. [0010] A very important characteristic of most two dimensional Cartesian systems used for legal descriptions is that they have no actual spatial relationship to each other, in many cases not even if two parcels are contiguous. In other words, given the legal descriptions of two parcels of land that are within a half mile of each other, it is not likely that their actual physical spatial relationship can be established based upon the descriptions alone. This is illustrated in FIG. 2 , which depicts a possible orientation of the parcel boundaries based on deed or legal descriptions of the same parcels illustrated in FIG. 1 . The orientations depicted in FIG. 2 are the orientations that must be used within the CAD drawings and associated point databases to produce plats of survey. Without a common coordinate or grid reference system which may be used to tie these disparate parcels together, the interpretation might result in the parcels “floating about in space,” as depicted in FIG. 2 . [0011] One way to establish the actual physical spatial relationship between two surveys is to measure from one parcel to the other so as to establish their relative positions. Prior to GNSS, if a surveyor wanted to determine the spatial relationship on the surface of the earth between every survey performed, the surveyor might have to physically traverse on the ground between every one of those surveys using an electronic total station, theodolite, EDM, or other suitable measuring device. Even if it were feasible to do this, it would not be possible to do so with sufficient accuracy due to the large propagation of error that would result. With the advent of GNSS and the coming on line of over 1000 Continuously Operating Reference Station (CORS) control points throughout the United States, the situation has changed with regard to coordinating and referencing different surveying jobs. [0012] A CORS control point is a permanent fixed GPS antenna and receiver that records GPS satellite signals 24 hours a day, 7 days a week, and transmits that data as soon as it is collected to the National Geodetic Survey (NGS) where it immediately becomes available at no cost to anyone with Internet access (NGS is a branch of the National Oceanographic and Atmospheric Administration (NOAA)). The location of every CORS antenna and its electronic phase center is known and monitored with extraordinary accuracy in relation to a comprehensive continental coordinate system and datum called “NAD 83 (CORS).” The coordinates of the CORS are given in terms of geodetic latitude, longitude, and ellipsoid height defined on the WGS84 ellipsoid, a mathematical surface designed to approximate the shape of the earth. These highly accurate coordinates are down loadable from NGS websites. The network of National and Cooperative CORS constitutes the National Spatial Reference System. [0013] An NGS Web site defines the NSRS as follows: “The National Spatial Reference System (NSRS), defined and managed by the National Geodetic Survey (NGS), is a consistent national coordinate system that specifies latitude, longitude, height, scale, gravity, and orientation throughout the Nation, as well as how these values change with time.” “NSRS consists of the following components: A consistent, accurate, and up-to-date National Shoreline; the National CORS, a set of Global Positioning System Continuously Operating Reference Stations meeting NOAA geodetic standards for installation, operation, and data distribution; a network of permanently marked points including the Federal Base Network (FBN), the Cooperative Base Network (CBN), and the User Densification Network (UDN); and a set of accurate models describing dynamic geophysical processes affecting spatial measurements.” “NSRS provides a highly accurate, precise, and consistent geographic reference framework throughout the United States. It is the foundation for the National Spatial Data Infrastructure (NSDI), a critical component of the ‘information superhighway.’ NSRS is a significant national resource—one whose value far exceeds its original intended purpose.” [0021] Surveyors may use an extremely accurate type of positioning utilizing GPS, known as dual frequency relative positioning, which requires that two or more GPS receivers operate simultaneously receiving and recording satellite data from common satellites. With the two or more GPS receivers operating simultaneously and receiving signals from common satellites, the satellite data recorded by the receivers can be downloaded to a computer and post-processed using software designed for that purpose (GPS that utilizes post-processed vectors is called static GPS). The result is a highly accurate vector within WGS84 defining the relative position of the two GPS antennas. Very importantly, if the absolute position of one of the antennas is known and held fixed within the NSRS, then the vector derived from post-processing is no long relative and determines the absolute position of the second antenna or point. [0022] When surveyors use dual frequency relative positioning GPS, one of the two GPS antennas is usually called a base station and remains positioned over a control point in the ground for many hours at a time, sometimes over successive days. The other antenna and receiver is called the rover and is moved from point to point with short occupation times in order to establish real time kinematic (RTK) GPS vectors or post processed static GPS vectors relative to the base station. If, in addition to deriving RTK and or static vectors between the base station and rover, vectors are also derived between the base station and one or more CORS through static post-processing, then highly accurate absolute positions for both the base station location and the points located by the rover relative to the base station can be computed within the NSRS. Because many large survey firms now employ GPS routinely in connection with most of their surveys, it may be possible for them to practically establish the absolute (within the NSRS or some other encompassing coordinate system) and therefore relative positions of those surveys to a very high degree of accuracy. Any measurement errors in the vectors from three or more CORS to the base station can be adjusted, for example by the method of least squares, holding the published CORS coordinates fixed. Such an adjustment computation may result in positions for the base station, and the associated points within a particular survey job, that exceed in accuracy the positions that could be achieved through the use of conventional traverses run by using electronic total stations and tying the surveys to conventional ground control stations. These higher levels of accuracy can be achieved virtually every time with generally two hours of observation at the base station by post processing base station GPS data with CORS control point data that has been downloaded from NGS websites. The CORS data may have been collected hundreds of miles from the base station and the site of the survey. [0023] A few states in the United States have what are called virtual reference systems (VRS). Europe is blanketed by such systems. A VRS is a network of CORS that immediately relay their data to a central computer that then models the atmospheric corrections over the area encompassed by the network. These atmospheric corrections are then conveyed via cell phone to GPS rovers operating in the field. The result is real time or RTK positions at the rover without the need for a base station set up near the site of the survey. In the United States VRS systems are all operating on the NSRS and NAD 83 (CORS). Therefore a surveyor who is operating in a VRS is automatically establishing a link between local survey points and an encompassing coordinate system, in this case the NSRS. [0024] In order for GPS located points to be usable for spatially relating unconnected surveys in a high accuracy survey-grade GIS their WGS84 latitude and longitude coordinates must be transformed into grid coordinates by defining a map projection. The term “grid” refers to a Cartesian coordinate system that is the result of a map projection. A map projection projects points on a curved surface onto a conical or cylindrical three dimensional surface which can be cut and laid flat, thereby transforming coordinates for points located in three dimensions on a curved and irregular surface into points represented in a flat two dimensional frame. A map projection typically includes an ellipsoid designed to approximate some aspect of the earth's surface (such as, but not limited to, mean sea level) and a conical or cylindrical surface passing through or around the ellipsoid onto which points on the surface of the earth are projected. From a simple geometric standpoint that can be visualized, a projection can be accomplished by projecting lines from the center of the ellipse through points on the surface of the earth (see FIGS. 3 , 5 ). Where the lines intersect the conic or cylinder defines the location of the points in the grid system when the conic or cylinder is cut and laid flat. In most practical applications a map projection is a mathematical operation defined by functions that relate geodetic latitudes and longitudes in a spherical system to X and Y coordinates in a two dimensional Cartesian grid system. [0025] The tradeoff for representing on a flat surface the relative size, shape, and location of figures that exist on a curved surface is that the correct shapes and distances as they exist on the curved surface become distorted on the flat surface. This is evident to anyone who has seen a flat map of the world and noticed that Greenland appears to be larger than the continental United States. The larger the area of the earth depicted using a map projection, the greater the distortion. The converse is also true, as the area of the earth encompassed by a map projection becomes smaller so to can the distortion. Because the areas over which it may be desirable to spatially relate surveys is on the order of several square miles, it becomes possible to design map projections that reduce the difference between grid distances and ground distances to an order well within the measurement tolerances associated with the best practices of land surveying. [0026] Because the coordinates that are produced using GPS are in terms of latitudes and longitudes, which are defined in a three dimensional spherical frame, these coordinate systems cannot be used as a basis for spatially relating legal descriptions which are defined within two dimensional Cartesian coordinate systems, as are required in the development and processing of local land surveys. The local land surveys are typically referenced to a locally optimized coordinate system and may be arranged so that a computed grid distance and a measured ground distance are within an acceptable level of tolerance for any location where the local coordinate system may be used. [0027] It is desirable that improvements to the processing of coordinates for disparate surveying jobs in a particular geographic area be made so that surveys of different origins and dates can be compared and harmonized with each other. SUMMARY [0028] Virtually real time availability via the Internet of data from the current network of over 1000 Continuously Operating Reference Stations (CORS), in conjunction with a similar availability of precise GPS satellite orbital data (necessary for accurate post processing over long distances), allows any surveyor with dual frequency GPS receivers to determine, with extraordinary accuracy, the location of a point within the NSRS, and therefore a survey within the NSRS, after only several hours of logging satellite data at a base station and post-processing that data to multiple CORS that are hundreds of miles away. The static vectors from three or more CORS can be adjusted by the method of least squares holding the published CORS coordinates fixed. This results in positional accuracy within the NSRS that exceed the day to day conventional traverses run by surveyors using electronic total stations. [0029] Although it is now possible to very accurately determine the physical position all surveys in relation to each other, most plats of survey must be produced and drafted on individual Cartesian coordinate systems that have no spatial relationship. The problem then becomes how to transform the drawings and databases of multiple surveys on multiple unrelated coordinate systems to a common system that results in grid coordinates as being ground coordinates. [0030] County Coordinate Systems, such as those developed for the state of Wisconsin by the Wisconsin Department of Transportation, can in some areas provide one solution to the multi-coordinate system problem. County Coordinate Systems have unique map projections for each county that reduce the difference between grid and ground distances to a negligible level. If two or more points from a survey are tied to the NSRS, which represents an encompassing coordinate system in latitudes and longitudes, and transformed to a map projection for a Wisconsin County Coordinate System, and if these same points exist in the drawing database used to produce the survey, then a relationship exists between the coordinate system in which the survey is produced and the County Coordinate System, where grid distances are virtually ground distances over several miles in many areas of the state of Wisconsin. Transformation of a survey drawing file and associated point database into a County Coordinate System then becomes a simple non-scaled translation and rotation defined by the points common to both systems. In this way otherwise unconnected surveys can be spatially united on a common coordinate system that retains ground distances as grid distances over areas as large as several miles. [0031] GIS software is the ideal engine for transforming multiple surveys into a common coordinate system. GIS software can access drawing databases and GPS post processing/adjustment databases and identify common points. For each survey drawing and point database chosen for transformation, the GIS finds specially tagged points in a GPS post processing/adjustment database in a County Coordinate System. The GIS software then finds the corresponding point numbers in the survey database used to draft each survey. Corresponding coordinates representing the same physical points in two separate coordinate systems define a unique transformation applied to each survey to transform each survey into the appropriate County Coordinate System. [0032] In the process of producing a survey, it is not uncommon for a drawing and associated database to go through several translations and rotations in an attempt to arrive at the best boundary solution. Because the transformation to a County Coordinate System is defined by points that exist within a survey drawing database, translating and rotating that database does not alter the transformation to the county system. [0033] It is an object of this invention to provide a method whereby any number of land survey electronic drawing files, or any electronic drawing representing measured features on the surface of the earth, along with associated or attached point databases, can be spatially integrated and combined with high survey-grade accuracy within a Geographic Information System and not introduce any meaningful distortion in distances as measured on the ground. It is a further object of this invention that the spatial integration will be based on the current condition, in terms of orientation, of the surveys integrated. It is a further object of this invention that the point data and drawing features so integrated can be exported into new drawing and point databases in such a manner that the source of the exported point information can be traced to its original database. It is a further object of this invention that such method will not hinder or disrupt in any way the customary office procedures employed within survey departments to produce plats of survey and to manage point databases. BRIEF DESCRIPTION OF THE DRAWINGS [0034] The drawings illustrate the best mode presently contemplated of carrying out the invention. In the drawings: [0035] FIG. 1 is a depiction of the actual spatial relationship between four parcels of land; [0036] FIG. 2 is a depiction of the same four parcels of land with bearings and distances from deed or legal descriptions; [0037] FIG. 3 is an illustration of a State Plane Coordinate system map projection; [0038] FIG. 4 is a depiction of the dimensions of a parcel of land on both a State Plane Coordinate grid system and as measured on the ground per a legal description; [0039] FIG. 5 is an illustration of a County Coordinate System map projection; [0040] FIG. 6 is a depiction of the orientation of three parcels of land and a transformation of the drawing entities from deed or legal description-based coordinates into a single local grid system; and [0041] FIG. 7 illustrates the transformation of drawing entities and associated point databases from deed or legal description-based coordinate systems to a single local grid system. [0042] FIG. 8A illustrates a parcel surveyed on the ground using a total station surveying instrument. [0043] FIG. 8B illustrates the parcel of FIG. 8A with two corners of the parcel each occupied by a global positioning system (GPS) receiver. [0044] FIG. 9 illustrates the downloading of data regarding the survey from both the total station surveying instrument and the GPS receivers into an automated system for analysis. [0045] FIG. 10A illustrates the surveyed parcel of FIG. 8A with local coordinates for the GPS points shown. [0046] FIG. 10B illustrates the GPS points of FIG. 8B with vectors to distant known control points and one of the points shown, and a vector between the two GPS points shown. [0047] FIG. 11 illustrates a latitude and longitude computed for the GPS points of FIG. 10 from the vectors to the known control points, and a table populated with computed latitude and longitude of the first GPS point, a unique identifier and other data regarding the first GPS point. [0048] FIG. 12 illustrates a process of updating a survey project database within a geographic information system (GIS) indicating the location of the first GPS point computed in FIG. 11 . [0049] FIG. 13 illustrates a process for associating points within the survey from the total station with the GPS points, so that coordinates of the GPS points in two different coordinate systems are associated with each other. [0050] FIGS. 14A to 14W are screen shots of a preferred embodiment of the software for processing two or more surveys into a common local grid coordinate system according to the present invention. [0051] FIG. 15 is a schematic view of a virtual box drawn about a plurality of surveying projects represented as dots. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0052] The survey of real property is typically a blending of legal interpretation with engineering precision to determine the location of a line demarcating legal ownership or other legal interest on the face of the Earth. Once the legal interpretation of the evidence of the location of such delineations has been performed, the lines representing these delineations can then be measured using conventional engineering and surveying techniques. The measurements can then be used to generate maps or other representations (both hardcopy and electronic or digital) of the location of the lines on the surface of the Earth. The accumulation of these lines in a closed traverse is typically done to generate a representation of a parcel of real property rights. As shown in FIG. 1 , almost all parcels share lines or boundaries with adjoining parcels. [0053] Surveying a parcel of land typically includes a first task of reviewing information such as recorded plats or legal descriptions written in deeds or other instruments of ownership. From these plats or legal descriptions, a surveyor may go into the field and attempt to locate all of the relevant corners of the parcel on the ground. This can be accomplished through a combination of measuring from other corners of the parcel, recovering prior monuments indicating where the corner may be located, or using other reference marks, monuments or geographic features. Once the corners of the parcel have been located, the actual measurement of the locations can commence. While the plat or legal description may generally locate the parcel on the face of the Earth with reference to existing geographic or legal features, the location of the actual corners of the parcel to be measured is dependent on a set of legal and evidentiary guidelines and the interpretation of the surveyor. [0054] When surveying a particular parcel, examination of one or more earlier surveys of one of more adjacent or nearby surveys might be useful and many times mandatory for the surveyor in determining the lines of the parcel in question. As noted above, a survey of parcel D may be aided by the knowledge of the lines derived during earlier surveys of parcels A, B, and C. Such earlier surveys may be used to verify the location of the common lot line between adjacent parcels. However, even if the existence of a prior survey of an adjacent parcel is known, depending on field measurement data collected and the means of reduction of the data to produce the map or other depiction of the adjacent parcel, the line work of the earlier survey may not be useable by the surveyor of the current survey. This lack of usability of the earlier survey results may be caused by differences in the error tolerances between the earlier survey and the present survey, differences in the map projection used and the coordinate system in which the surveys are to be generated, as well as the use of disparate control points or control reference networks between the surveys. [0055] It is desirable that a common reference framework be used to ensure that surveys at least are tied to a consistent level of control. It is also desirable that the results of surveys be presented in coordinate systems or projections which permit adjacent or nearby surveys to be relatively positioned with respect to each other with a low level of ground distance distortion in the projection of the location of points of a survey into grid coordinates. [0056] All states within the Unites States have official State Plane Coordinate (SPC) systems which are grid coordinate systems generated by map projections designed to encompass one or more regions or zones within a state. Because of the large size of the areas encompassed by SPC systems, the distances between points as measured on the ground are shorter or longer in comparison to distances given in the grid systems. In the state of Wisconsin for example, the difference between ground distance and SPC grid distance can be as high as 1.0 feet over a distance of one mile. The difference between ground and grid distance increases as the separation of two points increases (See FIGS. 3 and 4 ). Spatially relating legal descriptions and plats of survey using SPC grid systems may introduce an unacceptable amount of distortion in distances derived from computed grid coordinates and actual ground distances measured. This is due to the SPC system being optimized to fit the state as a whole, where there may be distinct land forms and other geographic features. As the SPC system has to average all of these statewide distortions, in any given location within the state, the difference between grid and ground distances may be unacceptable. [0057] The Wisconsin Department of Transportation has developed the Wisconsin County Coordinate System that defines a local map projection for each county in the state of Wisconsin. These grid systems are based on map projections that are designed to encompass and be optimized for no more than one county. As a result, the difference between county coordinate grid distances and ground distances in many counties, and over areas spanning several miles, is insignificant compared to the errors of measurement associated with the best practices of land surveying. The Wisconsin County Coordinate System may therefore be a suitable grid system in some areas for the transformation of GPS derived latitudes and longitudes into map projected coordinates for the purpose of spatially relating unconnected surveys. [0058] Survey crews using electronic total stations and GPS may perform field measurements and computations for a property survey and then utilize a local Cartesian coordinate system appropriate for or specified for the deed or legal description for that property. In carrying out the survey in the field, the points to be surveyed may be determined and marked, as noted above. A GPS base station is allowed to run for several hours during the survey at a base point within the parcel or parcels to be surveyed, while a GPS rover occupies and makes observations at the marked points and any other points of interest in the survey area. As an alternative to use of a GPS rover to visit all of the points of interest within the survey, more traditional traversing may be carried out to locate points within the survey area. For example, such traversing could be carried out through the use of a total station, provided these traverses are tied to at least two of the points included in the GPS survey. For example, the traverse could extend between the point occupied by the base station and some other point in the survey. Data collected by the total station and GPS receivers may then be downloaded into computers at the office. The data collected during the survey is in the form of measurements related to a local assumed Cartesian coordinate system which is based on location information of the recorded plat or legal description. This data is on a local system and is used to draft the plat of survey. [0059] GPS data from one or more CORS stations is downloaded from the Internet into GPS office software, along with precise satellite orbital data. This CORS data and orbital data are post-processed in order to derive vectors from the CORS stations to the base station at the site of the survey. Once vectors from the referenced CORS control points are derived, adjustment computations may be used to calculate high accuracy coordinates within the NSRS for the base station within the current survey area. A GPS vector for at least one other point within the current survey area must also be derived, using relative vectors measured from the base station to the desired additional point(s). [0060] Latitudes and longitudes within the NSRS may then be transformed into Wisconsin County Coordinates which may be stored within a point database or some other form of digital memory for use in later calculations. Data or field notes relating to any traverses that were performed using more traditional surveying methods and which were tied to GPS points can also be used to compute County Coordinates for any non-GPS points included in the traverse. [0061] In the adjustment computation, coordinates of the CORS stations may be held fixed in a least squares adjustment, as these coordinates are verified and calculated to a very high level of absolute accuracy. Holding these point coordinates as fixed in the adjustment computation will thereby improve the accuracy of the NSRS coordinates calculated for the base points within the current survey area and will permit the generation of probable Easting and Northing errors, or a resulting error ellipse, for the location of the base station. [0062] As an alternative to using post processed GPS vectors from CORS stations to the site of the survey, a VRS may be used. In this case there may not be a base station at the site of the survey. If VRS is used exclusively then the rover must take measurements on at least two points on the survey. [0063] The same procedures may used for a second survey of a contiguous, overlapping, adjacent or nearby unconnected survey. This is shown in FIG. 2 . As shown in FIG. 1 , the actual layout of the parcels on the ground has the parcels arranged in a particular orientation. When each parcel is surveyed using its internal coordinate system, (as indicated by the bearings included with each of the measured boundaries), the parcels wind up oriented as shown in FIG. 2 , even though these surveys may be performed to the same level of internal accuracy in the measurement and adjustment of the relative locations of the points within each survey. [0064] The net result of the preceding process may be two point databases or more broadly two sets of points from two distinct surveying jobs which may be in two different coordinate systems. [0065] It should be noted that for the purposes of this approach to coordinating surveyed points in different coordinate systems, it is assumed that each of the surveys involved include an acceptable level of internal integrity. In other words, the angles turned and distances measured (assuming a theodolite was used), or the relative GPS positioning between points of the survey are all of high enough accuracy and have been adjusted as necessary to apportion or eliminate systematic or random errors according to normal surveying adjustment computations. Once the internal integrity of these surveys has been established and coordinates in some required or chosen coordinate system have been computed, the approach disclosed in the present disclosure may be used to bring points portrayed in different coordinate systems to a common geographic base. [0066] Because the internal integrity of each survey is presumed to be of an acceptable level, it is desirable that the geometry of each survey be held fixed during the relating of the different surveys to a common coordinate base. In the example shown in FIGS. 1 and 2 , it should be noted that each of the surveys in FIG. 2 have acceptable internal geometry. Note that the rightmost boundary of Parcel B and the rightmost boundary of Parcel C are actually parallel as they exist on the ground (as shown in FIG. 1 ) while they are depicted as differing in bearing by over seventeen degrees in FIG. 2 . In this example, all three of the surveys depicted are internally accurate but projected into distinct coordinate systems, where collinear or parallel sides do not appear to line up with each other. While this is exaggerated for the purposes of this example, it serves to illustrate that although each survey might be internally geometrically acceptable, its external geometry might not be acceptable. [0067] One conventional approach to bringing these two surveys together would require that all of the points in one or both surveys be readjusted. Such a conventional approach might include a comprehensive least squares or other similar readjustment approach, which might allow all of the points to be readjusted without any regard for the original geometry of the surveys. However, since it is desirable to hold the internal geometry of each survey fixed through the computations, only translations and rotations of the constellation of points as a group are performed, according to the present invention. To accomplish this translation and rotation, at least two points are required. [0068] In general terms, two or more points from each survey will be used to accomplish any required or desired rotation and translation of that survey, while bringing each survey to a common geographic base or projection. While the translation and rotation may be referred to as being applied to the survey as a whole, the rotation and translation of each survey are actually carried out by computing new coordinates for each of the points defining endpoints or intermediate vertices of line segments within each survey. Such a translation and rotation of a survey may also include the computation of points related to the survey but which are not associated with or part of a boundary line, such as geographic or manmade features measured in the field and/or located on the survey plat. Each survey can be rotated as necessary to bring the geometries of each survey into alignment, as shown in FIG. 7 . A general approach to accomplishing this translation and rotation of the different surveys is described below as an example of one embodiment of the present invention. The description of the preferred embodiment below in not intended to limit the scope or nature of the present invention and is provided as an illustrative example only. [0069] In FIGS. 8 to 13 , illustrations of the portions of the preferred embodiment are provided. The preferred embodiment described below illustrates how each survey is processed from field data collection to preparation for transformation to a local grid coordinate system in conjunction with another survey. While the transformation of coordinates into a local grid coordinate system for a single survey may be carried out independently of any other survey, typically, two or more surveys which are adjacent or nearby to each other will be processed at generally the same time or simultaneously. [0070] FIGS. 8A and 8B illustrate two representations of a survey of a parcel 100 , with FIG. 8A showing a total station 10 being used to traverse the parcel or measure distances and angles between points and lines defining a boundary of the parcel. FIG. 8B shows a first GPS receiver 12 (“A”) and a second GPS receiver 14 (“B”) positioned at two points or corners of the parcel that have been included in the traverse measured by total station 10 . [0071] FIG. 9 shows the data from the various surveying instruments being downloaded to an office computer 16 . The environment of office computer 16 may define or be a part of a GIS. Data from total station 10 is downloaded to and processed by a computer aided drafting (CAD) software package 18 and a drawing of the parcel surveyed is compiled with an associated point database. These coordinates are computed in a local coordinate system appropriate for the particular survey. Data from GPS receivers 12 and 14 are downloaded to a GPS post processing software package 20 and an associated point database is compiled from the data. Data from the CORS stations is downloaded into the GPS post processing software and vectors are derived from the CORS stations to the base point number 1 linking point number 1 to the NSRS. A GPS vector is also derived from point number 1 to point number 4 which ties point number 4 to the NSRS. The GPS post processing software is then used to transform the latitudes and longitudes within the NSRS of point number 1 and point number 4 to the applicable county coordinates. [0072] In FIG. 10A , parcel 100 is illustrated as the CAD drawing, with all of the measured and corrected distances and angles defining the internal geometry of the parcel measured on the ground by total station 100 . Note that local coordinates are computed for both of the points occupied by GPS receivers 12 and 14 . In FIG. 10B , GPS receivers 12 and 14 , as they were positioned at the points of parcel 100 , are illustrated with measured vectors to a plurality of known CORS control points which are located outside of parcel 100 . The descriptions of points 1 and 4 are modified to indicate that there are GPS derived grid coordinates for these points. [0073] FIG. 11 shows a table being populated with the latitude and longitude of point 1 , derived from the GPS measured vectors. The lat/long of point 1 can be used to locate the survey of parcel 100 with regard to other surveys so that these surveys can be quickly located for reference in future projects or surveys and so that they can appear in their correct relative locations as points on a map in the GIS system. [0074] The point description of a point that represents the central location of the survey in the GPS database on the County Coordinate System is modified to include the text string “WGS84” (this text string is arbitrary and other text strings or identifiers could be used; the inclusion of this text string could also be done in the field at the time of data collection). The point descriptions of two points in the GPS database County Coordinate System are modified to include respectively the text strings “GPS1” and “GPS2” (this text string is arbitrary and the modification could also be done in the field at the time of data collection). [0075] A project point extraction software routine is launched which is used to extract information from the GPS database on the Wisconsin County Coordinate System. This information is used to populate a project point database that contains a field related to the survey project number, a field for the latitude of the point with WGS84 in its description, a field for the longitude of the point with WGS84 in its description, and a field for the county in which the survey resides. [0076] When a survey project number is entered into a field in the project point extraction software, the software goes out to the GPS database associated with the survey project number, it searches that database for the point with WGS84 in its description field, it then extracts from that database the latitude and longitude for the WGS84 point and the county in which the survey resides and populates the corresponding fields of the project point database with this information. [0077] GIS software 30 may now be launched, as shown in FIG. 12 . This software contains the routines and tools for completing the process of spatially relating the CAD drawings and associated point databases of different surveys. These tools are illustrated in FIGS. 12 and 13 , and the screen shots attached collectively as FIGS. 14A to 14W . [0078] The “Update County project points” tool updates a shape file with the information contained in the project point database. This shape file is used to display the location of surveys as project points on a map of the state of Wisconsin. These locations are based on the latitude and longitude of the WGS84 modified point description associated with each survey. [0079] The “Default Layers” tool brings up the “View or Update Default Layers” dialog box that allows the user to set the default layers that will be imported into the GIS from the CAD drawing that is selected for each survey. [0080] The “Default LDD Codes” tool brings up the “View or Update Default LDD Codes” dialog box. This box allows the user to set a default code list for selecting points from the point databases associated with the CAD drawings. [0081] The “Select Project Points” tool allows the user to select the project points for which CAD drawings and associated point databases for different surveys will be transformed into shape files on county coordinates, thereby spatially relating them. [0082] Additional dialog boxes may appear as shown in the screen shots. [0083] When a survey is selected in order to transform its CAD drawing and associated database, which are on a deed or legal description based Cartesian coordinate system, to a County Coordinate System, the GIS may go out to the GPS database containing the points in the county coordinate system. It searches this database for the points with “GPS1” and “GPS2” in the description field. The GIS extracts the point numbers for these two points. The GIS then goes out to the point database with the Cartesian coordinate system based on the deed or legal description that produced the survey and drawings. The GIS searches this database for the point numbers that were extracted for “GPS1” and “GPS2.” The GIS then extracts CAD drawing layer entities and points from the associated point database and translates and rotates them based upon the coordinates for “GPS1” and “GPS2” in each coordinate system (See FIGS. 6 and 7 ). [0084] It is also anticipated that a completely arbitrary grid coordinate system may be defined on the fly and selected to use as a basis for associating and/or registering two or more nearby survey projects. Such an arbitrary grid coordinate system might be used when the survey projects of interest are located across jurisdictional boundaries from each other, such as county or state lines. Often, surveys in different jurisdictions must be expressed in different coordinate systems as mandated by the local or state government. As an example, in Wisconsin, under a prior state defined and mandated county reference framework, a plurality of county level coordinate systems were defined (some covering a single county, others covering a plurality of counties), each using a slightly different defined ellipsoid. There are mathematical relationships defined between each local coordinate system and each defined ellipsoid, permitting coordinates to be transformed between the different county coordinate systems. However, for relating survey projects lying in different jurisdictions, coordinates of points within one or more of the projects in a first jurisdiction will need to be transformed into coordinates of a different jurisdiction, which may introduce coordinate distortions. Another reason to be able to define a grid coordinate system on the fly is that few states have county coordinate systems. Another reason is that even if county coordinate systems exist they may not, do to elevation differences and or the size of the county, result in grid distances being sufficiently close to ground distances over several miles in some areas. Another reason to be able to create local grid systems on the fly is so that the GIS will operate in any country regardless of the existence of suitable preexisting grid coordinate systems. [0085] According to the present disclosure, an arbitrary coordinate system can be defined as needed to encompass only those survey projects of interest. With reference to FIG. 15 , using a point 502 within each project, for example but not limited to, a point where a GPS base station was positioned, a virtual box 500 can be defined to encompass the northing and easting of each point 502 of the selected projects. A central location 504 , such as a centerline, central meridian or center point of virtual box 500 can be derived. From this derived central line or point 504 , an elevation for virtual box 500 with respect to a standard ellipsoid can be calculated. This elevation can be, for example, derived from a standardized national model or some other large scale consistent model. As an alternative, the virtual box elevation could be calculated as a mean of a derived elevation for a plurality of points within virtual box 500 . [0086] This derived elevation can be used to define the local map projection which may be used to provide a common basis for the projects within the virtual box. The local map projection can be based on whatever projection may be appropriate for the size and shape of the virtual box, which is in turn based on the relative positions of the survey projects to be transformed. Common examples of suitable projections include, but are not limited to Transverse Mercator and Lambert Conformal conic projections. Any of these local projections may be based on the same ellipsoid with the derived elevation providing a mean height above the ellipsoid for the projection to be located. By defining the box to encompass all of the survey projects of interest, the local ad hoc grid coordinate system can be chosen to optimize a fit with a minimum grid-to-ground discrepancy, and to have the area(s) of least discrepancy between grid and ground distances within the local coordinate system projection to be centered over the area of interest. Larger, predefined coordinate systems and projections, such as a county-wide coordinate system may not be optimally sized or positioned for the particular area of interest. Or, the survey projects of interest may lay on different sides of a jurisdictional boundary to which the predefined local coordinate system and projection were made to fit, so that a non-optimal extension of the predefined coordinate system is necessary to encompass all of the projects. [0087] Once this ad hoc local projection has been defined and calculated for the specific projects of interest, the process of defining translations and rotations can be performed, as described above. This would generally involve using the various GPS or other National Spatial Reference System (NSRS) positioned points within each project to define translations and rotations to be applied to calculate local grid coordinates for each point of each project. The translations and rotations can then be applied to the various projects to provide coordinates for each point in the local grid coordinate system. Again, as noted above, the selection of the local projection is intended to permit calculation of coordinates for the points within each project so that calculated grid distances derived from the coordinates will match the actual distances measured on the ground. It is desirable that, while the difference between grid-derived and ground-measured distances may not be absolutely identical, these distances should match within a specified level of significance. [0088] Within the present disclosure, it is preferable that the match between grid and ground distance can be kept with at least the minimum level of accuracy mandated by the ALTA/ACSM (American Land Title Association/American Congress on Surveying and Mapping) standards, described above in the background. The minimum relative positional accuracy required to meet the standards are 0.07 feet (or 20 mm)+50 ppm. This is one commonly accepted manner of providing a specification for relative positional accuracy for land surveying where the standard has some variability based on the distance being measured on the ground. [0089] Another commonly accepted manner of referring to relative positional accuracy in land surveying is to express it directly for a particular survey. Thus, the accuracy of the survey can then be compared to the standard to determine if the survey satisfies the minimum requirements. When the accuracy of a particular survey is expressed, it is typically expressed in terms of error per distance measured. As indicated in claims 20 and 21 , this may commonly be shown as a dimensionless ratio. For example, when the relative positional accuracy for a survey is computed to be one foot over the distance of a mile, the accuracy of the survey could be stated as one part in five thousand two hundred and eighty. [0090] Applying the ALTA/ACSM standard to a survey covering one mile, the minimum relative positional accuracy allowable would be (0.07 feet+((5280 feet/1,000,000)*50 ppm)), or 0.334 feet over one mile. Expressed as a dimensionless ratio, this is one part in fifteen thousand eight hundred and eight (1:15808). For a survey covering two miles, the equation would be (0.07 feet+((10560 feet/1,000,000)*50 ppm)), or 0.598 feet over two miles. Expressed as a dimensionless ratio, this is one part in seventeen thousand six hundred fifty eight (1:17658). Within the present disclosure, selection of the appropriate projection may allow the difference between the grid and ground distances to be held better than the ALTA/ACSM standards, for example, the accuracy may be held to one part in thirty thousand, or even to one part in two hundred thousand or better. [0091] If a virtual box is defined by projects that are separated too far geographically and/or elevation-wise to conform with a maximum allowable error between grid-derived and ground measured distances, the system and method of the present disclosure may still permit the projects to be moved with respect to each other but may highlight that the potential error is beyond the statutory or professionally mandated limits. While it may be desirable to have maximum potential error between surveys transformed to a common local coordinate system meet professional or statutory standards, there may also be other reasons for coordinating surveys that do not require that these standards be met. [0092] Using the system and methods of the present disclosure, it is possible to adjust or transform any group of two or more survey projects to a common local coordinate system. Each of the survey projects to be transformed needs to have control points within the survey database that are tied to a national spatial reference system or some earth-centric or encompassing coordinate system. The control points within each survey project do not need to be directly referenced to the same coordinate system for the disclosed system and methods to operate. So long as the control points are referenced to coordinate systems or projections which can be mathematically related. If the control points are referenced in different coordinate systems or projections, it may be necessary to perform an intermediate coordinate transformation to one or more of the survey project point databases prior to the definition of the local coordinate system to which all of the survey projects will be related. [0093] Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.

A method of coordinating surveys of different origins and which may be projected into different coordinate systems. The method provides a translation and rotation of the surveys to be coordinated without disturbing the internal geometry of each survey. A geographic information system including a procedure for coordinating surveys of different origins and/or which surveys which projected in different coordinate systems.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is related to co-pending U.S. Design patent application [Attorney Docket Number 65744/D006US/10610645], entitled “ULTRASOUND DISPLAY APPARATUS,” U.S. Design patent application [Attorney Docket Number 65744/D007/10612314], entitled “MOBILE SUPPORT STRUCTURE FOR MEDICAL EQUIPMENT,” and U.S. Design patent application [Attorney Docket Number 65744/D008/10612315], entitled “TILT CONTROL APPARATUS,” all filed concurrently herewith, the disclosures of which are hereby incorporated by reference. TECHNICAL FIELD [0002] This invention relates to medical equipment and more particularly to docking stations for use with such medical equipment and even more particularly to docking stations having auxiliary power management. BACKGROUND OF THE INVENTION [0003] All too often, minutes, and sometimes even seconds may mean the difference between life and death in hospital emergency rooms, EMT ambulances and other trauma sites, such as for example, explosion and crash sites, battlefields, etc. The advent of portable diagnostic equipment, such as sonogram equipment, now allows first responders to diagnose internal trauma and other ailments. The mortality and morbidity rate is thus decreased when the diagnostic tools that were once only available at fixed locations, such as hospitals and other trauma centers, can be brought to a patient. [0004] The same positive results that stem from fast diagnostic capabilities exist in fixed locations when the equipment can be easily moved from location to location instead of remaining fixed. This then allows the diagnostic tools to move to the patient instead of the patient being moved to the equipment. [0005] This portability is not without some complications. Even with highly portable equipment there sometimes is a need to “rest” the equipment on a dock so that the care giver can adjust knobs, take notes, move the probe, download information, charge the battery, and/or perform other tests on a patient. Also, all portable equipment must have a source of power. When working in a fixed facility, that source of power is the electrical utility usually manifest by power outlets spaced apart on a wall. When the device is in the portable mode a battery inside the device is used to provide power. However, just like so many of the devices (cellular telephones, pagers, etc) that are in common usage, battery management becomes critical. [0006] When any number of different people use a certain piece of equipment, such as a medical diagnostic tool, in a portable mode, battery management becomes critically important. One can hardly imagine a more inopportune time for the power to fail than when a measurement is being taken on a critically sick or injured person using a portable diagnostic tool. Precious life-threatening minutes are then lost in opening the device, retrieving the old battery, finding a new charged battery and then inserting the new battery and resealing the device. And all this presumes that the care giver has a freshly charged battery near by. In fast-paced trauma situations, this can be problematical. SUMMARY [0007] When portable diagnostic medical equipment is placed into a dock, or docking station, the batteries of the docking station are used in a hierarchical manner to insure the system battery maintains its maximum charged value. In one embodiment, the docking station has a plurality of batteries and the system is designed so that when a portable diagnostic device is docked, the power from the docking station batteries will be used in a predetermined usage pattern so as to preserve (and optionally charge) the batteries in the portable diagnostic tool. [0008] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0009] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: [0010] FIG. 1 shows one embodiment of a medical diagnostic tool operating in portable mode in accordance with the principals of the concepts of this invention; [0011] FIG. 2 shows one embodiment of a controller for operating the diagnostic tool shown in FIG. 1 ; [0012] FIG. 3 illustrates the tool of FIG. 1 mated with a dock; and [0013] FIG. 4 is one example of a flow chart of system operation. DETAILED DESCRIPTION OF THE INVENTION [0014] FIG. 1 shows one embodiment of medical diagnostic tool 10 operating in portable mode in accordance with the principals of the concepts of this invention. One example of such a tool is shown in the above-identified co-pending design patent application. Medical diagnostic tool 10 , in this embodiment a hand-held ultrasound diagnostic tool, is shown with housing 11 display screen 12 , input keys 13 and probe 15 connected to the tool by cable 14 . Also shown are connector 16 used when tool 10 is in mated relationship with dock 30 ( FIG. 30 ). Connector 16 also provides control for allowing the tool to “know” when it is in such mated relationship. [0015] When tool 10 is in portable or hand-held mode power is supplied to the device by one or more batteries (as will discussed with respect to FIG. 2 ) internal to tool 10 as contained, for example, within controller 20 . [0016] FIG. 2 shows one embodiment of a controller, such as controller 20 , for operating diagnostic tool 10 . In the embodiment controller 20 is shown with various internal control devices such as, for example, processor 201 , memory 202 , display control 203 , keypad control 204 and probe control 205 . Bus 200 allows these device to work together and the operation of these devices, as well as other internal control devices for diagnostic tools, and especially for ultrasound devices, are well-known in the art and will not be further discussed herein. [0017] Battery 21 serves to provide power to the control devices and systems of device 10 when device 10 is operating in hand-held mode and not plugged into a source of premises power. When premises power is available and being used, plug 23 would deliver power to converter 22 (in one embodiment) which in turn delivers power to the control devices. Note that converter 22 can be external to the device if desired. Converter 22 could be assisted by battery 21 . If desired, battery 21 can be separated from the external source of power, or battery 21 can become charged from converter 22 . In some situations this charge can be controlled by a control device, such as charge control 23 (which could be external to the device) and which operates in the well-known fashion to prevent battery 21 from becoming overcharged. While only one battery 21 is shown, many such batteries can be used. [0018] Note that contact 210 is in the “normal” mode such that power is available to flow from battery 21 , or from converter 22 , to power distribution bus 220 . When processor 201 senses a mated condition with a docking stand, via sensor 16 , device 210 serves to isolate battery 21 from input Al (from dock 30 , FIG. 3 ) as will be discussed hereinafter. Note also that isolating device 210 can be a relay contact or a semi-conductor device or any other type of isolation device desired. [0019] FIG. 3 illustrates the mating of diagnostic tool 10 with dock 30 to form combination 300 . When tool 10 is in mated relationship with dock 30 sensors within connector 16 causes controller 35 to respond by enabling one of the three batteries 31 , 32 or 33 via control 301 , 302 or 303 . If desired, the system battery (battery 21 , FIG. 2 ) can also be inserted into the list of batteries that are used for running the tool. The batteries are enabled according to a pre-set pattern so the system battery (if it is connected) is the last to be exhausted. Power from the enabled battery is supplied via lead Al and connectors 36 and 16 to tool 10 to run the operation of tool 10 even if that tool is being used to perform diagnostic tests. As discussed above, battery 21 in tool 10 is isolated from controller 20 at this time and is available to be charged via leads B 1 and B 2 from dock 30 , FIG. 3 , via controls 304 - 1 and 304 - 2 . Controls 304 - 1 and 304 - 2 can be 2-relay contacts or semi conductor devices Also, if desired, one or more batteries 31 , 32 and 33 can be connected to leads B 1 and B 2 if desired so that one or more of these batteries can be used to charge system battery bank 21 [0020] Note that in the embodiment shown a separate battery is shown in dock 30 for charging device 10 's internal battery. This configuration is not necessary and any arrangement of batteries can be used to run and charge device 10 including having the same power source on dock 30 perform both functions, if desired. [0021] Batteries 31 , 32 and 33 are arranged in a hierarchical order but, if desired could be used concurrently, if desired. The theory of operation being that when device 10 is removed from dock 30 its internal system battery, or batteries, will be as fully charged as possible. [0022] FIG. 4 is one example of flow chart 40 of system operation. Process 401 determines if the diagnostic device is mated in the dock. If it is, then process 402 determines if the device is running on utility (for example 110V AC) power. If so, theoretically the internal battery of device 10 is being charged from the power source and thus there is not a need for additional charging as shown by process 411 . [0023] If, however process 402 determines that device 10 is running on internal power, then process 403 isolates, in one embodiment, the internal battery of device 10 . Process 406 selects a first battery to connect to device 10 for operational purposes, as discussed above. Optionally, if process 404 determines that device 10 internal battery is to be charged, then process 405 connects stand battery to the device battery. [0024] When process 407 determines that the first battery is becoming (or has become) discharged, then if process 408 determines that there are other external batteries available a new battery is selected via process 410 and the operation of device 10 continues being powered from external batteries. [0025] If process 408 determines that there are no more charged batteries then, optionally, an alarm is sounded so that a user can plug the dock, or the diagnostic device, into a source of power so that the internal batteries of device 10 remain in the highest possible charge condition so that device 10 will be available for emergent conditions when they occur despite the fact that the device has been operating in a portable mode for a period of time. [0026] Note that while three batteries are shown in dock 30 (and one in device 10 ) any number of such batteries can be used. By using multiple batteries, particularly in the dock, and by isolating their employment, one or more batteries can be physically changed even while device 10 is operating at full capacity. Note also, that should the external batteries begin to fail, device 10 could be switched, automatically or otherwise, to a lower power consumption state to conserve power. Again, the idea being to maintain device 10 so that it can perform its diagnostic duties fully on portable power at a moments notice in an emergent condition. [0027] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

When portable diagnostic medical equipment is placed into a dock, or docking station, the batteries of the docking station are used in a hierarchical manner to insure that the batteries in the portable equipment become charged and that any power needed to run the portable device is provided from a power source local to the docking station. In one embodiment, the docking station has a plurality of batteries and the system is designed so that when a portable diagnostic device is docked, the power from the docking station batteries will be used in a predetermined usage pattern so as to preserve (and charge) the batteries in the portable diagnostic tool.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application claims the benefit of, and priority to, U.S. provisional applications 60/640,998, filed Jan. 4, 2005, and 60/702,318 filed on Jul. 26, 2005. FIELD OF THE INVENTION [0002] The present invention is directed to a therapeutic membrane composition formed by self-assembling peptides and platelet derived growth factor (PDGF). The membrane/PDGF complex may be implanted or injected into the heart of a patient to provide for the long term release of free PDGF. BACKGROUND OF THE INVENTION [0003] Certain peptides are capable of self assembly when incubated in the presence of a low concentration of monovalent metal cation (U.S. Pat. No. 5,670,483; U.S. Pat. No. 6,548,630). Assembly results in the formation of a gel-like membrane that is non-toxic, non-immunogenic and relatively stable to proteases. Once formed, membranes are stable in serum, aqueous solutions and cell culture medium. They can be made under sterile conditions, are capable of supporting the growth of cells and are slowly digested when implanted in an animal's body. These characteristics make the membranes well suited as devices for the delivery of therapeutic agents. Among the most promising of such agents is platelet-derived growth factor (PDGF). [0004] PDGF is a mitogen for connective tissue cells, fibroblasts and smooth muscle cells. It has been implicated as contributing to malignant transformation (Clarke, et al., Nature 308:464 (1984); Gazit, et al., Cell 39:89 (1984); Beckmann, et al., Science 241:1346 (1998); Smits, et al., Am. J. PathoL 140:639 (1992)); and, by promoting the growth of endothelial cells, may contribute to the angiogenesis needed to sustain tumor growth. There is also evidence that PDGF contributes to the restenosis that often occurs after angioplasty (Ferns, et al., Science 253:1129-1132 (1991); Rutherford et al., Atherosclerosis 130:45-51 (1997); Jawien et al. J. Clin. Invest. 89:507-511 (1992)) and to the development of fibrotic lesions in several different organs ( Experimental Pharmacology, Peptide Growth Factors and Their Receptors, Sporn & Roberts, eds., pp. 173-262, Springer, Heidelberg). [0005] From a therapeutic perspective, PDGF appears to play a role in promoting the growth of neuronal tissue and in wound healing (Deuel, et al., J. Clin. Invest. 69:1046-1049 (1981); Siegbhan, et. al., J. Clin. Invest. 85:916-920 (1990); Smits, et al., Proc. Natl. Acad. Sci. USA. 88:8159-8163 (1991); Yeh, et al., Cell 64:209-216 (1991); Robson, et al., Lancet 339:23-25 (1992)). There are also indications that PDGF may be used to help preserve cardiac function in patients following a myocardial infarction. cl SUMMARY OF THE INVENTION [0006] One problem with using membranes formed from self-assembling peptides for drug delivery is that compounds simply enmeshed in the peptide matrix, tend to be rapidly lost after implantation due to the high permeability of membranes. The present invention is based upon the discovery that PDGF, and particularly the B chain of PDGF, binds naturally to self-assembling peptides. This allows biological membranes to be formed that have immobilized PDGF directly attached and which can be implanted in vivo without the PDGF being rapidly washed away. Using a rat model of myocardial injury, membranes with bound PDGF can be locally injected into injured myocardium and are retained at the delivery site for at least 14 days after coronary artery ligation. As a result, cardiomyocyte death is decreased and myocardial systolic function is preserved. Thus, membranes with bound PDGF provide an effective method for preventing heart failure after myocardial infarction. [0007] In its first aspect, the invention is directed to a biologically compatible peptide membrane made of self-assembling peptides. The term “biologically compatible” indicates that the membranes are non-toxic and can be safely implanted in a patient. The self-assembling peptides should be 12-200 amino acids in length and have alternating hydrophobic and hydrophilic amino acids. In addition, the peptides should be complementary (i.e., they should be able to form ionic or hydrogen bonds with one another) and structurally compatible (i.e., the bound peptide chains should maintain a distance from one another that does not vary by more than about three angstroms throughout their length). In general, at least 0.1 %, more preferably 0.5% - 10%, and still more preferably 1-10% of the peptides that assemble into the membrane should be bound directly to PDGF. The term “bound directly” as used herein means that there is no linker or other molecule interspersed between PDGF and peptide. The term also requires that there be a physical interaction of some type between the PDGF and peptide (e.g., an ionic bond, hydrophobic interaction etc.) that prevents the PDGF from diffusing away from peptide in aqueous medium as it would do if simply enmeshed within the gel matrix. [0008] In preferred embodiments, the self-assembling peptides used in membranes are between 12 and 24 amino acids in length, have PDGF attached to about 4-8% of the peptides, and are homogeneous. The term “homogeneous” as used in this context indicates that all of the peptides forming the biologically compatible membrane are identical. The term “heterogeneous” refers to non-identical peptides that are used to form membranes. Specific peptides that may be used in the membranes described above include: AKAKAEAEAKAKAEAE,; (SEQ ID NO:1) AKAEAKAEAKAEAKAE,; (SEQ ID NO:2) EAKAEAKAEAKAEAKA,; (SEQ ID NO:3) KAEAKAEAKAEAKAEA,; (SEQ ID NO:4) AEAKAEAKAEAKAEAK,; (SEQ ID NO:5) ADADARARADADARAR,; (SEQ ID NO:6) ARADARADARADARAD,; (SEQ ID NO:7) DARADARADARADARA,; (SEQ ID NO:8) RADARADARADARADA,; (SEQ ID NO:9) ADARADARADARADAR,; (SEQ ID NO:10) ARADAKAEARADAKAE,; (SEQ ID NO:11) AKAEARADAKAEARAD,; (SEQ ID NO:12) ARAKADAEARAKADAE,; (SEQ ID NO:13) AKARAEADAKARADAE,; (SEQ ID NO:14) AQAQAQAQAQAQAQAQ,; (SEQ ID NO:15) VQVQVQVQVQVQVQVQ,; (SEQ ID NO:16) YQYQYQYQYQYQYQYQ,; (SEQ ID NO:17) HQHQHQHQHQHQHQHQ,; (SEQ ID NO:18) ANANANANANANANAN,; (SEQ ID NO:19) VNVNVNVNVNVNVNVN,; (SEQ ID NO:20) YNYNYNYNYNYNYNYN,; (SEQ ID NO:21) HNHNHNHNHNHNHNHN,; (SEQ ID NO:22) ANAQANAQANAQANAQ,; (SEQ ID NO:23) AQANAQANAQANAQAN,; (SEQ ID NO:24) VNVQVNVQVNVQVNVQ,; (SEQ ID NO:25) VQVNVQVNVQVNVQVN,; (SEQ ID NO:26) YNYQYNYQYNYQYNYQ,; (SEQ ID NO:27) YQYNYQYNYQYNYQYN,; (SEQ ID NO:28) HNHQHNHQHNHQHNHQ,; (SEQ ID NO:29) HQHNHQHNHQHNHQHN,; (SEQ ID NO:30) AKAQADAKAQADAKAQAD,; (SEQ ID NO:31) VKVQVDVKVQVDVKVQVD,; (SEQ ID NO:32) YKYQYDYKYQYDYKYQYD,; (SEQ ID NO:33) HKHQHDHKHQHDHKHQHD,; (SEQ ID NO:34) RARADADARARADADA,; (SEQ ID NO:35) RADARGDARADARGDA,; (SEQ ID NO:36) RAEARAEARAEARAEA,; (SEQ ID NO:37) KADAKADAKADAKADA,; (SEQ ID NO:38) AEAEAHAHAEAEAHAH,; (SEQ ID NO:39) FEFEFKFKFEFEFKFK,; (SEQ ID NO:40) LELELKLKLELELKLK,; (SEQ ID NO:41) AEAEAKAKAEAEAKAK,; (SEQ ID NO:42) AEAEAEAEAKAK,; (SEQ ID NO:43) KAKAKAKAKAEAEAEA,; (SEQ ID NO:44) AEAEAEAEAKAKAKAK,; (SEQ ID NO:45) RARARARADADADADA,; (SEQ ID NO:46) ADADADADARARARAR,; (SEQ ID NO:47) DADADADARARARARA,; (SEQ ID NO:48) HEHEHKHKHEHEHKHK,; (SEQ ID NO:49) VEVEVEVEVEVEVEVEVEVE,; (SEQ ID NO:50) and RFRFRFRFRFRFRFRFRFRF,. (SEQ ID NO:51) [0009] It should be recognized that each of the peptides listed above includes a repeating sequence and that additional repeats can be included to extend the length of the peptides without destroying their ability to self-assemble. For example, the peptide AKAKAEAEAK AKAEAE (SEQ ID NO:1) has the repeating sequence AKAKAEAE (SEQ ID NO:52) and can be expressed as (AKAKAEAE) n , (SEQ ID NO:52) where n=2. Longer peptides capable of self assembly can be made by increasing n with the caveat that the total number of amino acids in the final peptide cannot exceed 200. Preferred peptides are those having the following repeating structures: (RARADADA) n (SEQ ID NO:53) (ARARADAD) n (SEQ ID NO:89), (RADARADA) n , (SEQ ID NO:54) and (AEAEAKAK) n , (SEQ ID NO:55) in which n=2-10. Preferably, n=2-4 and more preferably, n=2. [0010] Other peptides expressed in this manner and useful in the invention are: (AKAKAEAE) n , (SEQ IDNO:52) where n=2-25; (KAEA) n (SEQ ID NO:56) where n=3-50; (EAKA) n (SEQ ID NO:57) where n=3-50; (KAEA) n (SEQ ID NO:58) where n=3-50; (AEAK) n (SEQ ID NO:59) where n=3-50; (ADADARAR) n (SEQ ID NO:60) where n=2-25; (ARAD) n (SEQ ID NO:61) where n=3-50; (DARA) n (SEQ ID NO:62) where n=3-50; (RADA) n (SEQ ID NO:63) where n=3-50; (ADAR) n (SEQ ID NO:64) where n=3-50; (ARADAKAE) n (SEQ ID NO:65) where n=2-25; (AKAEARAD) n (SEQ ID NO:66) where n=2-25; (ARAKADAE) n (SEQ ID NO:67) where n=2-25; (KARAEADA) n (SEQ ID NO:68) where n=2-25; (AQ) n where n=6-100; (VQ) n where n=6-100; (YQ) n where n=6-100; (HQ) n where n=6-100; (AN) n where n=6-100; (VN) n where n=6-100; (YN) n where n=6-100; (HN) n where n=6-100; (ANAQ) n (SEQ ID NO:69) where n=3-50; (AQAN) n (SEQ ID NO:70) where n=3-50; (VNVQ) n (SEQ ID NO:71) where n=3-50; (VQVN) n (SEQ ID NO:72) where n=3-50; (YNYQ) n (SEQ ID NO:73) where n=3-50; (YQYN) n (SEQ ID NO:74) where n=3-50; (HNHQ) n (SEQ ID NO:75) where n=3-50; (HQHN) n (SEQ ID NO:76) where n=3-50; (AKAQAD) n (SEQ ID NO:77) where n=2-33; (VKVQVD) n (SEQ ID NO:78) where n=2-33; (YKYQYD) n (SEQ ID NO:79) where n=2-33; (HKHQHD) n (SEQ ID NO:80) where n=2-33; (RARADADA) n (SEQ ID NO:53) where n=2-25; (RADARGDA) n (SEQ ID NO:81) where n=2-25; (RAEA) n (SEQ ID NO:82) where n=3-50; (KADA) n (SEQ ID NO:83) where n=3-50; (AEAEAHAH) n (SEQ ID NO:84) where n=2-25; (FEFEFKFK) n (SEQ ID NO:85) where n=2-25; (LELELKLK) n (SEQ ID NO:86) where n=2-25; (AEAEAKAK) n (SEQ ID NO:55) where n=2-25; (AEAEAEAEAKAK) n (SEQ ID NO:87) where n=1-16; (KAKAKAKAEAEAEAEA) n (SEQ ID NO:44) where n=1-12; (AEAEAEAEAKAKAKAK) n (SEQ ID NO:45) where n=1-12; (RARARARADADADADA) n (SEQ ID NO:46) where n=1-12; (ADADADADARARARAR) (SEQ ID NO:47) where n=1-12; (DADADADARARARARA) n (SEQ ID NO:48) where n=1-12; (HEHEHKHK) n (SEQ ID NO:88) where n=2-25; (VE) n where n=6-100; and (RF) n where n=6-100. [0011] Membranes can be formed from the self-assembling peptides and then administered to a patient. Alternatively, the peptides and PDGF can be incorporated into an injectable pharmaceutical composition at a concentration of monovalent cation that is too low to induce membrane formation. This can then be administered to induce membrane formation in vivo. The invention encompasses the pharmaceutical compositions containing the PDGF and peptides as described above. [0012] The invention also includes methods of treating patients using the membranes or pharmaceutical compositions described herein. Patients can be treated for any condition in which PDGF has been found to be useful and where implantation is appropriate. For example, membranes may be used to deliver PDGF at wound sites, at joints in which there is damage to a ligament, tendon or cartilage or at sites where neurons have been damaged. The most preferred use is in the treatment of patients that have had a myocardial infarction. In this case, the membrane should be injected directly into the myocardium as soon after the myocardial infarction as possible. The total amount of PDGF delivered will be determined on a case by case basis but, in general, should be between about 1 ng and 500 μg and, preferably between 10 ng and 100 μg. [0013] In another aspect, the invention includes methods of making the biologically compatible membranes described above. This is accomplished by combining the self-assembling peptides in an aqueous medium containing sufficient monovalent metal cation to promote self assembly. Preferably, an aqueous solution containing a salt of the metal cation is formed first and peptides are then added to a final concentration of at least 1 mg/ml and preferably, at least 10 mg/ml. The concentration of monovalent metal cation can vary considerably but, in general, should be at least 5 mM. The upper limit for the cation is at least 3 M but assembly of peptides may occur at concentrations as high as 5 M. Preferred cations include lithium, sodium and potassium. These may be provided as salts in conjunction with essentially any pharmaceutically acceptable anion, including chloride, acetate and phosphate. The use of divalent cations should be avoided as these appear to interfere with peptide assembly. Similarly, concentrations of detergent, such as sodium dodecyl sulfate (SDS) of 0.1% or higher, should generally be avoided. [0014] PDGF may be combined with the peptides either prior to, or after, self assembly. In general, sufficient PDGF should be added so that 0.1-10% of the peptides in the final assembled membrane have PDGF attached. However, an upper limit on the percentage of peptides that can be occupied has not yet been determined and, if desired, more than 10% (e.g., 15%, 25%) can be bound. It should be recognized that these percentages express the relative amount of PDGF molecules to peptides and do not necessarily mean that the PDGF is homogeneously distributed throughout the membrane. For example, the phrase “10% of peptides are bound to PDGF” means that, on average, one out of every 10 peptides are bound based on a knowledge of the number of PDGF molecules and the number of peptides present. Certain peptides may have more than one PDGF attached and others may have none. When membranes are formed prior to the attachment of peptides, the distribution of PDGF will tend to be less homogeneous than when peptides are bound prior to assembly. However, the non-homogeneous distribution should not affect the ability of the membranes to effectively deliver the PDGF after implantation. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 : Targeted delivery of PDGF-B with self-assembling peptide nanofibers into infarcted myocardium. Rat model of experimental myocardial infarction (MI) with peptide nanofiber (NF) injection. The peptide NF forms a gel-like structure after sonication and becomes consolidated after myocardial injection. The left coronary artery is permanently ligated, followed with 80 ul peptide NF injection in the border zones via 3 different directions. DESCRIPTION OF THE INVENTION [0016] The present invention is based upon the discovery that, in aqueous medium, PDGF-B spontaneously attaches to the self-assembling peptides described herein and is ultimately bound to the gel-like membranes that they form. It should be recognized that the term “membrane” in this context refers to a three dimensional solid hydrogel structure. For this reason, it may also be properly referred to as a “microenvironment.” The self-assembling peptides have been described in U.S. Pat. Nos. 5,670,483 and 6,548,630, both of which are hereby incorporated by reference. Essentially the same procedures described therein for making and using the peptides apply to the present invention. However, it has been found that PDGF can be non-covalently bound to the membranes formed by the self-assembling peptides by simply combining the membrane (or peptides) and PDGF in aqueous medium (e.g., water, saline or a buffer containing the components needed for the self assembly of peptides). It appears that, on average, at least 10% of the peptides within membranes can be bound to PDGF (i.e., 1 PDGF molecule bound for every 10 peptides) but an upper limit has not yet been determined and it may be possible to bind much larger amounts, e.g., 20%, 40%, 80% or more. [0017] Description of Peptides [0018] The peptides used for self assembly should be at least 12 residues in length and contain alternating hydrophobic and hydrophilic amino acids. Peptides longer than about 200 amino acids tend to present problems with respect to solubility and membrane stability and should therefore be avoided. Ideally, peptides should be about 12-24 amino acids in length. [0019] The self-assembling peptides must be complementary. This means that the amino acids on one peptide must be capable of forming ionic bonds or hydrogen bonds with the amino acids on another peptide. Ionic bonds would form between acidic and basic amino acid side chains. The hydrophilic basic amino acids include Lys, Arg, His, and Om. The hydrophilic acidic amino acids are Glu and Asp. Ionic bonds would form between an acidic residue on one peptide and a basic residue on another. Amino acids that form hydrogen bonds are Asn and Gln. Hydrophobic amino acids that may be incorporated into peptides include Ala, Val, Ile, Met, Phe, Tyr, Trp, Ser, Thr, and Gly. [0020] Self-assembling peptides must also be “structurally compatible.” This means that they must maintain an essentially constant distance between one another when they bind. Interpeptide distance can be calculated for each ionized or hydrogen bonding pair by taking the sum of the number of unbranched atoms on the side-chains of each amino acid in the pair. For example, lysine has five and glutamic acid has four unbranched atoms on their side chains. An interaction between these two residues on different peptides would result in an interpeptide distance of nine atoms. In a peptide containing only repeating units of EAK, all of the ion pairs would involve lysine and glutamate and therefore a constant interpeptide distance would be maintained. Thus, these peptides would be structurally complementary. Peptides in which the variation in interpeptide distance varies by more than one atom (about 3-4 angstroms) will not form gels properly. For example, if two bound peptides have ion pairs with a nine-atom spacing and other ion pairs with a seven-atom spacing, the requirement of structural complementarity would not have been met. A full discussion of complementarity and structural compatibility may be found in U.S. Pat. Nos. 5,670,483 and 6,548,630. The definitions used therein and examples provided apply equally with respect to the present invention. [0021] It should also be recognized that membranes may be formed from either a homogeneous mixture of peptides or a heterogeneous mixture of peptides. The term “homogeneous” in this context means peptides that are identical with one another. “Heterogeneous” indicates peptides that bind to one another but which are structurally different. Regardless of whether homogenous or heterogeneous peptides are used, the requirements with respect to the arrangement of amino acids, length, complementarity, and structural compatibility apply. In addition, it should be recognized that the carboxyl and amino groups of the terminal residues of peptides can either be protected or not protected using standard groups. [0022] Making of Peptides [0023] The self-assembling peptides of the present invention can be made by solid-phase peptide synthesis using standard N-tert-butyoxycarbonyl (t-Boc) chemistry and cycles using n-methylpyrolidone chemistry. Once peptides have been synthesized, they can be purified using procedures such as high pressure liquid chromatography on reverse-phase columns. Purity may also be assessed by HPLC and the presence of a correct composition can be determined by amino acid analysis. [0024] Formation of Membranes [0025] The self-assembling peptides described herein will not form membranes in water, but will assemble in the presence of a low concentration of monovalent metal cation. The order of effectiveness of these cations is Li + >Na + >K + >Cs + (U.S. Pat. No. 6,548,630). A concentration of monovalent cation of 5 mM should be sufficient for peptides to assemble and concentrations as high as 5 M should still be effective. The anion associated with the monovalent cation is not critical to the invention and can be acetate, chloride, sulfate, phosphate, etc. The PDGF-B will bind to the peptides at low salt concentration and will remain bound at concentrations sufficient to induce self assembly. Peptides can also form from self assembling peptides, and PDGF can attach, under conditions found in vivo. Therefore, it is possible to not only implant membranes, but also to implant either self-assembling peptides with attached PDGF or to co-implant self-assembling peptides and PDGF and to allow the membranes to form afterward. The term “implant” as used herein includes any method for introducing a membrane or peptides at a treatment site, including injection. [0026] The initial concentration of peptide will influence the final size and thickness of membranes formed. In general, the higher the peptide concentration, the higher the extent of membrane formation. Formation can take place in peptide concentrations as low as 0.5 mM or 1 mg/ml. However, membranes are preferably formed at higher initial peptide concentrations, e.g., 10 mg/ml, to promote better handling characteristics. Overall, it is generally better to form membranes by adding peptides to a salt solution rather than adding salt to a peptide solution. [0027] The formation of membranes is relatively unaffected by pH or by temperature. Nevertheless, pH should be maintained below 12 and temperatures should generally be in the range of 4-90° C. Divalent metal cations at concentrations equal to or above 100 mM result in improper membrane formation and should be avoided. Similarly, a concentration of sodium dodecyl sulfate of 0.1 % or higher should be avoided. [0028] Membrane formation may be observed by simple visual inspection and this can be aided, if desired, with stains such as Congo Red. The integrity of membranes can also be observed microscopically, with or without stain. [0029] PDGF [0030] Platelet-derived growth factor (PDGF) normally exists as a dimer composed of two homologous but distinct peptides termed PDGF-A and -B chains, and may exist as AA, AB, and BB isoforms. Unless otherwise indicated the term “PDGF” and “PDGF-B” as used herein refer to any form of human PDGF in which the B chain is present, i.e., the term encompasses B monomers as well as AB and BB dimers. It also is expected that minor changes can be introduced into the structure of the B chain without disrupting its function or ability to bind to membranes and it may be possible to form fusion proteins or derivitized forms of the B chain that are still able to bind to membranes and have a positive therapeutic effect. The full length amino acid sequence of PDGF has been known in the art for many years (see, Rao, et al., Proc. Nat'l Acad. Sci. USA 83:2392-2396 (1986)) and may be found, inter alia, as accession number P01127. The protein used herein can either be purchased commercially or synthesized using techniques well known in the art. [0031] Pharmaceutical Compositions and Dosages [0032] The compositions containing PDGF described above may be incorporated into a pharmaceutical composition containing a carrier such as saline, water, Ringer's solution and other agents or excipients. The dosage form will generally be designed for implantation or injection but topical dosage forms may be used in cases where the preparation will be used in the treatment of a wound or abrasion. All dosage forms may be prepared using methods that are standard in the art (see e.g., Remington's Pharmaceutical Sciences, 16th ed. A. Oslo. ed., Easton, Pa. (1980)). [0033] It is expected that the skilled practitioner will adjust dosages on a case by case basis using methods well established in clinical medicine. General guidance concerning appropriate amounts of gel-immobilized PDGF to administer to heart patients is provided above. However, the amounts recited are simply guidelines since the actual dose will be carefully selected and adjusted by the attending physician based upon clinical factors unique to each patient. The optimal dosage will be determined by methods known in the art and will be influenced by factors such as the age of the patient, disease state and other clinically relevant factors. EXAMPLES [0000] I. Introduction [0034] The present example demonstrates that protection of cardiomyocytes by endothelial cells is through PDGF-BB signaling. PDGF-BB induced cardiomyocyte Akt phosphorylation in a time- and dose-dependant manner and prevented apoptosis via PI 3 K/Akt signaling. Using injectable self-assembling peptide nanofibers, which bound PDGF-BB in vitro, sustained delivery of PDGF-BB to the myocardium at the injected sites for 14 days was achieved. A blinded and randomized study of 96 rats showed that injecting nanofibers with PDGF-BB, but not nanofibers or PDGF-BB alone, decreased cardiomyocyte death and preserved systolic function after myocardial infarction. A separate blinded and randomized study in 52 rats showed that PDGF-BB delivered with nanofibers decreased infarct size after ischemia-reperfusion. PDGF-BB with nanofibers induced PDGFR-β and Akt phosphorylation in cardiomyocytes in vivo. These data demonstrate that endothelial cells protect cardiomyocytes via PDGF-BB signaling, and that this in vitro finding can be translated into an effective in vivo method of protecting myocardium after infarction. Furthermore, this study shows that injectable nanofibers allow precise and sustained delivery of proteins to the myocardium with potential therapeutic benefits. [0000] II. Materials and Methods [0035] Myocardial Cell Culture [0036] Rat neonatal cardiomyocytes (1-2 days old) and adult cardiac endothelial cells and fibroblasts were isolated from Sprague-Dawley rats (Charles River Laboratories and Harlan) as previously described (Narmoneva, et al., Circulation 110:962 (2004)). [0037] Cardiomyocyte Apoptosis Assays [0038] Cardiomyocytes were plated at a density of 1.4×10 5 cells/cm 2 overnight, cultured in serum-free DMEM for 24 hours, and then subjected to 10 mM chelerythrine, 1 mM doxorubicin (both from Sigma-Aldrich), or 0.2 mM H 2 O 2 plus 100 ng/ml TNF-α (PeproTech) for another 24 hours with or without treatment with human PDGF-BB (PeproTech). In coculture experiments, before plating of cardiomyocytes, cardiac endothelial cells or fibroblasts were cultured until subconfluent. TUNEL staining was performed using a TUNEL staining kit (Roche Diagnostics Corp.). For DNA fragmentation experiments, cells were trypsinized, fixed with 80% ethanol at −20° C. for 2 hours, incubated in 0.1 mg/ml RNase (Sigma-Aldrich) at 37° C. for 30 minutes, stained with 0.1 mg/ml propidium iodide (Sigma-Aldrich) for 10 minutes, and then subjected to flow cytometry (Cytomics FC 500; Beckman Coulter). The Annexin-V cell sorting method was performed using an apoptosis assay kit (Vybrant Apoptosis Assay Kit #3; Molecular Probes, Invitrogen Corp.) following the manufacturer's instructions. The dosages for neutralizing antibodies were 0.4 μg/ml anti-PDGF-BB, 2 μg/ml anti-PDGFR-β, 2 μg/ml anti-PDGF-AA, and 20 μg/ml anti-PDGFR-a (all from Sigma-Aldrich except anti-PDGF-AA from R&D Systems), and the dosage of PDGF-BB was 10 ng/ml unless otherwise indicated. Adenoviral transfection was performed as previously described by Fujio and Walsh (Fujio, et al., J Biol. Chem. 274:16349-16354 (1999)). Each experiment was performed in triplicate and repeated at least 3 times using different primary cell preparations. [0039] Western Blot Analysis [0040] Whole-cell extracts were collected using lysis buffer containing 1% (wt/vol) SDS, 50 mM Tris-Cl (pH 7.4), 5 mM EDTA supplemented with 4× sample buffer (Invitrogen Corp.) and proteinase inhibitor cocktail (Sigma-Aldrich) at 1:500 dilution. The following antibodies were used: anti-PDGFR-β (Santa Cruz Biotechnology Inc.), anti-phospho-PDGFR-β, anti-Akt, anti-phospho-Akt, anti-phospho-ERK, anti-phosphop38, and anti-jun N-terminal kinase (all from Cell Signaling Technology). [0041] Immunocytochemistry [0042] For immunocytochemical staining of PDGFR-μ activation, cardiomyocytes were prepared using the same method as described above using anti-phospho-PDGFR-μ antibody (Cell Signaling Technology). [0043] Protein Binding Assay of Self-assembling NFs [0044] NFs were prepared as previously described (Narmoneva, et al., Circulation 110:962 (2004), and PBS or 100 ng of BSA (Sigma-Aldrich), PDGF-BB (PeproTech), VEGF-A, bFGF, or angiopoietin-1 (all from R&D Systems) was embedded in NFs. NFs were incubated with PBS (100 μl) at 37° C. for 3 hours. Supernatant (PBS after incubation) was collected and subjected to Bradford protein assay. In parallel experiments, the same amount of proteins was added in PBS but not embedded within NFs, in order to demonstrate that the experimental binding conditions were at equilibrium. [0045] MI and Injection of Peptide NFs [0046] All animal protocols were approved by thec Harvard Medical School Standing Committee on Animals. MI was producedc in approximately 250-g male Sprague-Dawley rats (Charles River Laboratories and Harlan). Briefly, rats were anesthetized by pentobarbital and, following tracheal intubation, the hearts were exposed via left thoracotomy. The left coronary artery was identified after pericardiotomy and was ligated by suturing with 6-0 prolene at the location approximately 3 mm below the left atrial appendix. For the sham operation, suturing was performed without ligation. Peptide NFs (peptide sequence AcN-RARADADARARADADA-CNH2 (SEQ ID NO:35); from SynPep Corp.) with or without 50 or 100 ng/ml human PDGF-BB (PeproTech) and/or 50 mM LY294002 (Calbiochem) were dissolved in 295 mM sucrose and sonicated to produce a 1% solution for injection. A total of 80 μl of self-assembling peptide NFs was injected into the infarcted border zone through 3 directions (equal amount for each injection) immediately after coronary artery ligation ( FIG. 1 ). Injections were completed within 1 minute after coronary ligation. Following injection, the chest was closed, and animals were allowed to recover under a heating pad. For the PDGF-BB retention study (120 surviving rats), animals were sacrificed after 10 minutes, 1 day, 3 days, or 14 days. [0047] For the functional and histological studies (126 surviving rats), rats were euthanized after 1, 14, or 28 days. For the PI3K/Akt blocking (16 surviving rats) and infarct size (64 surviving rats) studies, hearts were harvested after 24 hours. For the myocardial regional blood flow study (30 surviving rats), hearts were harvested for microsphere collection after 14 days. All of the procedures were performed in a blinded and randomized manner, and data were analyzed after there were at least 6 animals in each coded group. The overall surgical mortality rate in this study was 5.3% (20 of 376 rats, with 356 surviving rats for the study cohorts). [0048] ELISA [0049] For the in vivo PDGF-BB delivery study, myocardial protein was extracted from injected sites using a nonreducing buffer containing 1% Triton X-100, 50 mM Tris (pH 7.4), 300 mM NaCl, 5 mM EDTA, and 0.02% NaN3 supplemented with proteinase inhibitor cocktail (Sigma-Aldrich) at 1:200 dilution. The same amount of protein from each heart was loaded in triplicate for anti-human PDGF-BB ELISA following the manufacturer's instructions (R&D Systems). [0050] Fluorescence Microscopy [0051] Fixed myocardial sections were deparaffinized, rehydrated, and pretreated with boiling 10 mM sodium citrate (pH 7.2) for 10 minutes and 10 mg/ml proteinase K (Sigma-Aldrich) at room temperature for 10 minutes, followed by incubation with antibodies against phospho-PDGFR-β, cleaved caspase-3 (both from Cell Signaling Technology), Ki67 (Abcam), isolectin (Molecular Probes; Invitrogen Corp.), α-SMA, tropomyosin, vimentin (all from Sigma-Aldrich) at 4° C. overnight, and then Alexa Fluor-conjugated secondary antibodies (Molecular Probes; Invitrogen Corp.). Sections were next incubated with anti-α-sarcomeric actinin or tropomyosin (Sigma-Aldrich), followed with different Alexa Fluor secondary antibodies to obtain different fluorescence colors. After counterstaining with DAPI, sections were mounted and observed under fluorescence microscopy. For the vascular diameter measurement, sections were stained with isolectin or α-SMA and photographed, and the diameter was measured using Image-Pro version 4.5 (MediaCybernetics). [0052] Echocardiography [0053] Echocardiographic acquisition and analysis were performed as previously described Lindsey, et al., Circulation 105:753-758 (2002)). Left ventricular fractional shortening was calculated as (EDD-ESD)/EDD×100%, where EDD is end-diastolic dimension and ESD is end-systolic dimension. [0054] Immunohistochemistry [0055] Formalin-fixed, paraffin-embedded sections were prepared for immunohisto-chemistry as previously described (Davis, et al., Circulation 111:442-450 (2005); Weinberg, et al., Am. J. Physiol. Heart Circ. Physiol. 288:H1 802-H1 809 (2005)). The first antibodies used were anti-phospho-PDGFR-β, anti-phospho-Akt, anti-cleaved caspase-3 (all from Cell Signaling Technology), anti-neutrophil (Serotec), anti-mac3 (BD Biosciences), and anti-BrdU (Roche Diagnostics Corp.). [0056] Myocardial I/R and Measurement of Infarct Size [0057] Myocardial I/R and measurement of infarct size, as described previously (Weinberg, et al., Am. J. Physiol. Heart Circ. Physiol. 288:H1802-H1809 (2005)), were performed in rats. The ischemia time was 60 minutes and reperfusion period 24 hours. All of the procedures were performed in a blinded and randomized manner, and there were at least 6 animals in each group. [0058] BrdU Protocol [0059] Two hours before sacrifice, 50 mg/kg body weight of BrdU (Sigma-Aldrich) was injected i.p. in rats. BrdU staining was performed using the method described by Geary et al. (Geary, et al., Circulation 91:2972-2981 (1995)). A piece of small gut from each animal was used for positive control. [0060] DNA Synthesis [0061] Cell proliferation was measured using [ 3 H]thymidine incorporation into DNA as previously described (Schulze, et al., Circ. Res. 91:689-695 (2002)). [0062] Myocardial Regional Blood Flow Measurement [0063] Myocardial regional blood flow was measured using fluorescent microspheres as described by Van Oosterhout et al. (Van Oosterhout, et al., Am. J. Physiol. 269:H725-H733 (1995)) with modifications. Briefly, animals received heparin (about 2 U/g body weight) and were anesthetized. The entire heart was exposed via left thoracotomy, and the descending aorta was opened to insert a withdrawal catheter connecting to a bidirectional rolling pump. Blood was withdrawn at a rate of 1-2 ml/min for 2 minutes, starting 5 seconds before injection of fluorescent microspheres into the left atrium. The blood was transferred to a collecting tube containing 2 mg of EDTA, and the total amount was recorded. A total 30 μl of microspheres, a mixture of equal amount of blue-green (10-μm diameter; 3.6×10 4 beads), green (15-μm diameter; 1×10 4 beads), and yellow-green (10-μm diameter; 3.6×10 4 ) beads (all from Molecular Probes; Invitrogen Corp.), was injected for each rat. Animals were sacrificed 2 minutes after injection. After removing the entire heart, the infarcted myocardium at the left ventricle was identified, harvested, weighed, and stored at 4° C. A similar size of myocardium from the noninfarcted right ventricle was also harvested as a control. The blood and myocardium were then digested in 4 N KOH (>3×volume of samples) at 50° C. for overnight. After centrifuging at 2,000 g for 10 minutes, the pellet that contained microspheres was washed twice with 0.25% Tween-20 and then distilled water. The pellet was dissolved with 0.5 ml xylene and then incubated at 50° C. for 3 hours with intermittent vortex and sonication. The supernatant was collected and subjected to measurement of fluorescence intensity (Victor 2 ; PerkinElmer) with triplicates for each sample. The myocardial regional blood flow was calculated using the formula Q i =(Q ref ×F i )+F ref , where Q i and Q ref are the flow rates in samples and the reference withdrawal speed, respectively, and F i and F ref are the fluorescence intensity in myocardial samples and in the reference blood samples. After normalizing with weight, the absolute myocardial blood flow was expressed in milliliters/minute/gram. [0064] Statistics [0065] All data are expressed as mean ±SEM. Statistical significance was determined using the 2-tailed Student's t test or ANOVA as appropriate. Differences between groups were considered statistically significant at P<0.05. [0000] III. Results [0066] Endothelial Cells Promote Cardiomyocyte Survival via PDGF-BB/PDGFR-β Signaling [0067] Previous studies demonstrated that endothelial cells can prevent cardiomyocyte apoptosis in coculture (Narmoneva, et al., Circulation 110:962-968 (2004); Kuramochi, et al., J. Biol. Chem. 279:51141-51147 (2004)), a finding we explored further to establish conditions for quantitative delivery in vivo. Neonatal rat cardiomyocytes were cocultured with adult cardiac endothelial cells or fibroblasts, and cardiomyocyte apoptosis was induced by 3 different methods, including treatment with doxorubicin, chelerythrine, and H 2 O 2 plus TNF-α. Apoptosis was quantified with 3 independent assays, including in situ TUNEL staining, DNA fragmentation by propidium iodide staining, and annexin-V cell sorting. With each apoptotic stimulus, coculture with endothelial cells, but not fibroblasts, prevented cardiomyocyte apoptosis. The protection of cardiomyocytes from apoptosis in cardiomyocyte-endothelial coculture was blocked by neutralizing antibodies against PDGF-BB or PDGFR-β, but not by antibodies against PDGF-AA or PDGFR-α, indicating that endothelium-derived cardiomyocyte protection occurs through the PDGF-BB/PDGFR-β pathway. [0068] PDGF-BB Prevents Cardiomyocyte Apoptosis via PI3K/Akt Signaling [0069] To evaluate further the effects of PDGF-BB in cardiomyocyte apoptosis, we induced cardiomyocyte apoptosis by multiple methods with or without PDGF-BB and quantified apoptosis with 3 independent assays as described above. PDGF-BB prevented cardiomyocyte apoptosis irrespective of stimulus or assay, and there was a dose dependent antiapoptotic effect, with optimal results at PDGF-BB concentrations of 10 ng/ml and higher. PDGF-BB, but not PDGF-AA, induced phosphorylation of PDGFR-β, and the downstream kinase Akt in cardiomyocytes in a dose- and time-dependent manner but induced no significant activation of p42/p44 (ERK-½), p38, or jun N-terminal kinase from 5 to 60 minutes. Immunofluorescence costaining of phospho-PDGFR-β and α-sarcomeric actinin confirmed the activation and internalization of PDGFR-β in differentiated cardiomyocytes by PDGF-BB. Blocking Akt signaling using a PI3K-specific inhibitor (LY294002) or a dominant-negative Akt adenovirus abolished the prosurvival effect of PDGF-BB in cardiomyocytes, demonstrating that cardiomyocyte protection of PDGF-BB may occur via the PI3K/Akt pathway. These results show that PDGF-BB is a potential candidate cardiomyocyte survival factor for targeted delivery into the myocardium. [0070] Controlled Intramyocardial Delivery of PDGF-BB Using Injectable Self-assembling Peptide NFs [0071] To explore the possibility of using self assembling peptide NFs for controlled intramyocardial delivery of PDGF-BB, we first tested the binding capability of PDGF-BB by peptide NFs. Although these NFs do not have specific binding motifs for peptides, they are amphiphilic, with the potential to bind other proteins through weak molecular interactions. When PDGF-BB (100 ng total) was embedded with the NFs, the binding capacity was 1 ng PDGF-BB per microgram of NFs. This binding capacity was 10-fold higher than the amount of PDGF-BB per mass of NFs used in subsequent experiments in vivo (described below). We observed similar binding of other growth factors, including VEGF-A, bFGF, and angiopoietin-1, all of which bound significantly better to the peptide NFs than BSA. [0072] To assess the feasibility of delivering PDGF-BB with self-assembling peptide NFs into the myocardium for cardioprotection, we injected PDGF-BB with peptide NFs into the myocardium of rats. All of the procedures were blinded and randomized, with at least 6 animals in each group. Left coronary arteries were ligated, immediately followed by direct myocardial injection of 1% peptide NFs (peptide sequence AcN-RARADADARARADADA-CNH2 (SEQ ID NO:35) with or without PDGF-BB into the infarcted border zones at 3 locations. Protein extracted from the injected region was assayed by ELISA specific for human PDGF-BB. Human PDGF-BB was undetectable in rats with sham operation only, MI only, or MI with NFs (MI+NFs) only. [0073] Ten minutes after injecting 4 ng human PDGF-BB with or without peptide NFs, most of PDGF-BB was retained in the injected region in both groups (79.5%±18.3% in the group without peptide NFs and 91.8%±6.4% in the group with peptide NFs; P>0.05). Without peptide NFs, PDGF-BB rapidly disappeared from the injected sites after 24 hours, and only a negligible amount of PDGF-BB could be detected after 3 days. In contrast, with peptide NFs, PDGF-BB was retained at the injected sites; 16.1%±2.4% of PDGF-BB remained at the targeted delivery sites after 14 days (P<0.001 for PDGF-BB with NFs versus PDGF-BB without NFs at 1-, 3-, and 14-day time points). [0074] Immunohistochemical staining showed phosphorylation of PDGFR-β at the injected sites by NF/PDGF-BB, but not by NFs or PDGF-BB alone or in the sham or MI only after 14 days. Immunofluorescence costaining confirmed sustained activation of PDGFR-β in cardiomyocytes adjacent to the injected areas after 14 days. Furthermore, to determine more quantitatively the difference in PDGFR-β and Akt phosphorylation between groups, we used Western blotting to examine protein extracted from the injected sites and found sustained PDGFR-β and Akt phosphorylation 1 and 14 days after injection of NFs with PDGF-BB (NF/PDGF-BB). Injection of PDGF-BB alone slightly induced PDGFR-β and Akt phosphorylation after 1 day, but both disappeared by day 14. [0075] These results demonstrate that injectable self-assembling peptide NFs can successfully deliver PDGF-BB into the myocardium, leading to prolonged activation of the PDGF signaling pathway in cardiomyocytes in vivo. [0076] Injection of NF/PDGF-BB Preserves Myocardial Function [0077] To examine the functional effects of injecting self-assembling peptide NF/PDGF-BB for cardioprotection, we then performed a blinded and randomized study in 96 rats, with at least 6 animals in each experimental group. Two doses of PDGF-BB (50 and 100 ng/ml [P50 and P100]) were selected for injection, estimated to deliver approximate PDGF-BB concentrations in the infarcted myocardium of 10 and 20 ng/ml, respectively, by injecting a total of 80 μl (given at 3 different injection sites) of NF/PDGF-BB into 400 mg of infarcted myocardium. [0078] Twenty-four hours after MI, left ventricular fractional shortening decreased as anticipated compared with sham-operated myocardium (43.1%±7.7% in the sham group versus 27.5%±5.6% in the MI group; P<0.05), and injection of NFs or PDGF-BB alone did not significantly improve fractional shortening. However, in infarcted hearts with injection of NF/P50 or NF/P100, fractional shortening significantly improved (42.7%±7.1% and 43.0%±8.4%, respectively; P<0.05 for both versus MI or MI+NFs). [0079] At day 14 after infarction, improvement of fractional shortening was maintained in hearts that received NF/P100, but not in hearts that received NF/P50 (50.0%±8.7% in sham, 32.8%±4.2% after MI, 39.6%±7.9% in NF/P50, and 47.6%±10.0% in NF/P100; P<0.05 for sham versus MI and NF/P100 versus MI or MI+NFs), implying dose-dependent cardioprotection by sustained release of PDGF-BB from the peptide NFs. Consistent with the improvement of fractional shortening after infarction, injection of NF/PDGF-BB also prevented cardiac dilation as measured by ventricular end-systolic and end-diastolic dimensions (P<0.05). [0080] Using trichrome staining, we did not observe an increase in fibrosis by injection of NF/PDGF-BB, suggesting that injection of NF/PDGF-BB may not stimulate cardiac fibroblasts (Ponten, et al., Am. J. Pathol. 163:673-682 (2003)). [0081] Injection of NF/PDGF-BB Decreases Cardiomyocyte Apoptosis and Induces PI3K/Akt activation after infarction [0082] To address whether preservation of cardiac systolic function by injection of peptide NF/PDGF-BB was accompanied by prevention of cardiomyocyte apoptosis, we examined tissues using immunofluorescence costaining of cleaved caspase-3 and α-sarcomeric actinin. Injection of peptide NFs with 50 or 100 ng/ml PDGF-BB, but not NFs or PDGF-BB alone, dramatically decreased caspase-3 activation after 1 day (P<0.001 for 50 or 100 ng/ml PDGF-BB with NFs versus MI or MI+NFs). After 14 days, injection of NF/P100 reduced apoptosis more than injection of NF/P50, although both treatments significantly reduced apoptosis compared with controls (0.5%±0.2% in sham, 12.8%±1.1% in MI, 7.2%±0.8% in NFs with 50 ng/ml of PDGF-BB, P<0.01 versus MI; and 3.1%±0.4% in NFs with 100 ng/ml of PDGF-BB, P<0.001 versus MI). Furthermore, we demonstrated activation of Akt in the myocardium by injection of NF/PDGF-BB but not when NFs or PDGF-BB alone was injected, showing that this strategy induces survival signaling in the myocardium in vivo (Matsui, et al., Circulation 104:330-335(2001); Mangi, et al., Nat. Med. 9:1195-1201 (2003); Bock-Marquette, et al., Nature 432:466-472 (2004)). [0083] With addition of the PI3K-specific inhibitor LY294002 (50 μM) in peptide NF/PDGFBB, we found that Akt activation was blocked and improvement of fractional shortening by injection of NF/PDGF-BB was also abolished, implying that PI3K/Akt signaling may play a role in the cardioprotective effect of injecting peptide NF/PDGF-BB. Moreover, as multiple myocardial cells may be targets for PDGF-BB, we examined Akt phosphorylation in cardiomyocytes, endothelial cells, VSMCs, and fibroblasts after injection of NF/PDGF-BB using immunofluorescence costaining of phospho-Akt and cell-specific markers. We found that Akt phosphorylation was induced in cardiomyocytes after 1 and 14 days and also in endothelial cells after 14 days of injection. However, we were not able to detect Akt phosphorylation in VSMCs or fibroblasts. These results imply that cardiomyocytes are the main targets for PDGF-BB after injection of NF/PDGF-BB. [0084] Injection of NF/PDGF-BB Decreases Infarct Size After I/R Injury [0085] To investigate whether injection of NF/PDGF-BB may also benefit the heart from ischemia/reperfusion (I/R) injury, we conducted another blinded and randomized experiment in 52 rats to examine infarct size after 60-minute ischemia and 24-hour reperfusion (n=10 in sham and I/R alone groups; n=16 in I/R+NFs alone and I/R+NF/PDGF-BB groups). Injection of NF/P100, but not NFs alone, improved ventricular fractional shortening after 24 hours of reperfusion (50.3%±2.0% in sham, 36.1%±2.0% in I/R only, 41.9%±2.4% in I/R+NFs, and 51.3%±2.1% in I/R+NF/PDGF-BB; P<0.05 for I/R+NF/PDGF-BB versus I/R only or I/R+NFs). Infarct size, represented by percent of area at risk, was also decreased by injection of NF/PDGF-BB (0% in sham, 40.0%±2.3% in I/R only, 38.5%±2.2% in I/R+NFs, and 27.8%±2.4% in I/R+NF/PDGF-BB; P<0.01 for I/R+NF/PDGFBB versus I/R only or I/R+NFs). [0086] As expected, the area at risk, represented by the percentage volume of the left ventricle, was similar in I/R only, I/R+NFs, and I/R+NF/PDGF-BB groups, indicating that the location of coronary ligation was similar among the groups. We also generated a new randomized and blinded experiment to study the effects of PDGF-BB alone on infarct size (6 rats for I/R only and 6 rats for I/R+PDGF-BB) and did not observe statistical difference between these 2 groups (P=0.645). Taken together, these results demonstrate that injection of NF/PDGF-BB may preserve myocardial function after infarction and I/R injuries. [0087] Injection of NF/PDGF-BB Does Not Increase Myocardial Cell Proliferation Neovascularization, Regional Blood Flow, or Inflammation After Infarction [0088] Since PDGF-BB is a potent mitogen for many cells, we studied cell proliferation induced by PDGF-BB delivery in the infarcted myocardium using BrdU and Ki67 to label proliferative cells. Active cell proliferation could be detected in the positive control, rat small intestine, by BrdU staining. In contrast, less than 0.5% cells were BrdU positive in the periinfarct myocardium after 1, 14, and 28 days, and there were no differences in number of BrdU-positive cells among all of the study groups. Similar results were found using Ki67 staining. [0089] Interestingly, costaining Ki67 and cell-specific markers revealed that cell proliferation occurred only in endothelial cells and fibroblasts, but not in cardiomyocytes or VSMCs, and there were no differences in numbers of Ki67-positive cells between groups. Consistent with these results, using [ 3 H]thymidine incorporation assay, we found PDGF-BB did not induce DNA synthesis in cultured rat cardiomyocytes or cardiac fibroblasts but did increase DNA synthesis in human aortic smooth muscle cells. These results suggest that injection of NF/PDGF-BB does not induce cell proliferation in the ischemic myocardium. [0090] We then tested whether injection of NF/PDGF-BB could enhance neovascularization in the ischemic myocardium because we have previously found that injection of NFs alone in normal myocardium led to neovascularization within the NFs (Davis, et al., Circulation 111:442-450 (2005)). The overall capillary (endothelial cell staining) and arterial (VSMC staining) densities (vessel number per millimeter 2 ) in the periinfarct area were not changed by injection of NFs, with or without PDGF-BB, after 14 and 28 days of infarction. Vascular diameters were also not different between groups. Consistent with these data, using fluorescent microspheres, we found that regional blood flow in the myocardium was decreased 14 days after infarction, but not changed by injection of NF/PDGF-BB, NFs alone, or PDGF-BB alone. [0091] We also examined whether injection of NFs with or without PDGF-BB could trigger an inflammatory response and found that there was no increase in neutrophil or monocyte/macrophage infiltration after injection compared with MI without injection of NFs. [0092] Together these data suggest that improvement of cardiac function by NF/PDGF-BB injection may not result from improvement of blood supply. [0000] III. Discussion [0093] Given the rapid loss of cardiomyocytes after ischemic injury, promoting cardiomyocyte survival is an efficient strategy for preserving viable myocardium. The principal findings of this study are that PDGF-BB is an endothelium-secreted paracrine factor with direct antiapoptotic effects in cardiomyocytes and that this prosurvival signal can be delivered into the infarcted myocardium for cardioprotection in a highly controlled manner using injectable self-assembling peptide NFs. [0094] The results show that this strategy is highly effective for delivery of PDGF-BB in the early period after infarction; even after 14 days, 16% of PDGF-BB still remained in the injected sites. Compared with injection of PDGF-BB alone, which was rapidly eliminated after injection, NF/PDGF-BB injection achieved sustained delivery of PDGF-BB inside the myocardium. Importantly, PDGF-BB embedded within the NFs remained biologically active after 14 days of injection, inducing phosphorylation of PDGFR-β and Akt in cardiomyocytes through the entire layer of myocardium at the injected areas and, occasionally, even into the papillary muscles. [0095] All references cited herein are fully incorporated by reference. Having now fully described the invention, it will be understood by those of skill in the art that the invention may be practiced within a wide and equivalent range of conditions, parameters and the like, without affecting the spirit or scope of the invention or any embodiment thereof.

The present invention is directed to a therapeutic composition in which human PDGF is bound directly to peptides that self assemble into a biologically compatible gel. When implanted in a patient's body, the composition provides for the slow, sustained release of PDGF. The composition will be especially useful in treating patients who have undergone a myocardial infarction.

INCORPORATION BY REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. application Ser. No. 15/063,464, filed Mar. 7, 2016, which is a continuation of U.S. application Ser. No. 14/585,148, filed Dec. 29, 2014, which claims benefit under 35 U.S.C. §119(e) from U.S. Provisional Application No. 61/923,631, filed on Jan. 3, 2014. The above applications are hereby incorporated herein by reference in their entirety and are to be considered as a part of this specification. BACKGROUND OF THE INVENTION Field of the Invention [0002] This patent document relates to user removable protective enclosures or cases for mobile devices and more particularly to such cases that have a unique integrated multi-layered construction. Description of the Related Art [0003] Mobile devices, such as smart phones, tablets, laptops and the like are known to sustain damage from impact and from contamination as a result of ingress of water or other fluid. The damage, for example, may result in a cracked screen, scratches on a finished surface, lost or damaged buttons or controls, cracked or bent external body components, and/or failed or malfunctioning electrical components. Protective cases have thus been provided to protect mobile devices from such and variant types of damage. [0004] The bulkiness and weight of the protective case can be an issue for consumers. Thick and heavy cases, while capable of providing improved protection, are contrary to the very utilitarian qualities of mobility (lightweight and small size) that makes such mobile devices so attractive to consumers. Indeed many users carry their devices in their front or back pant pockets. Even a relatively modest increase in bulk or weight can, therefore, be more noticeable, uncomfortable, and less desirable. [0005] Accordingly, it is here recognized that there is a continuing and an ever increasing desire to minimize the bulkiness and weight of protective cases for mobile devices yet maintain a high level of protection. SUMMARY OF THE INVENTION [0006] There exists a continuing need for new and improved designs for protective cases for mobile devices that provide high level of protection, yet are low profile. [0007] Disclosed are numerous aspects of a unique and inventive protective case configured to receive, retain and protect a mobile device that includes a front face and a back face that define the height of the mobile device, a perimeter defined by top-end, bottom-end, right, and left sides residing between the front and back faces, and corners defined at the intersecting regions of the sides. The case may be for a mobile device that is in the form of a tablet, a mobile phone, an MP3 audio player, a gaming device, or other portable handheld electronic device and may have one or more touchscreens, including on its front face and/or back face. [0008] The case may be formed of multilayered construction that includes three layers, various aspects of which are described. The first layer is defined by inner and outer surfaces and dimensioned to cover a portion of the back face of the mobile device and/or extend around a portion of the perimeter of the mobile device at the back face boundary. The inner surface of the first layer includes a plurality of protrusions that extend in a direction generally away from the outer surface. [0009] The second layer is defined by inner and outer surfaces and also dimensioned to cover a portion of the back face of the mobile device and extend around a portion of the perimeter of the mobile device at the back face boundary. The second layer may further include a plurality of corner protrusions positioned along the perimeter region of the second layer to correspond in location with the corners of the mobile device. The second layer may further include an elevated pattern of interconnected walls extending from its inner surface a height above and in a direction away or opposite from the second layer's outer surface. The second layer further includes a plurality of apertures extending into its outer surface that surround (e.g., in close and firm proximity or contact with) one or more of the protrusions of first group of protrusions of the first layer. The second and/or first layers may each be configured to cover the entire, a majority, half or less than half of the back face of the mobile device and may be configured to extend around the entire, a majority, half or less than half of the perimeter of the mobile device at the back face boundary. [0010] The third layer is similarly defined by third inner and outer surfaces and dimensioned to cover a portion of the top-end, bottom-end, right and/or left sides of the mobile device. The third layer may include one or more indentations in its inner surface at the corners. The indentations may be in the reverse image of, or otherwise dimensioned to receive, one or more of the corner protrusions of the second layer. The third layer may also include control apertures that are dimensioned and positioned to allow access to control buttons or ports on the mobile device. [0011] The first, second, and third layers may be co-molded to form an integrated construction. The first layer may be made of a first material that has a first hardness, the second layer may be made of a second material that has a second hardness, and the third layer may be made of a third material that has a third hardness. The first hardness is greater than the third hardness, which in turn is greater than the second hardness. [0012] For example, the first layer may have a Shore A durometer hardness that is 40% or more greater than the third layer, 30% or more greater than the third layer, 20% or more greater than the third layer, or 10% or more greater than the third layer all +/−5% as measured using the American Society for Testing and Materials (ASTM) standard D2240. The second layer may have a Shore A durometer hardness of 45+/−10, 45+/−5, or 45 as measured using the American Society for Testing and Materials (ASTM) standard D2240. The third layer may have a Shore A durometer hardness of 65+/−10, 65+/−5, or 65 as measured using the American Society for Testing and Materials (ASTM) standard D2240. The third layer may also, for example, have a Shore A durometer hardness that is 40% or more greater than the second layer, 30% or more greater than the second layer, 20% or more greater than the second layer, or 10% or more greater than the second layer all +/−5% as measured using the American Society for Testing and Materials (ASTM) standard D2240. [0013] The first, second and third layers may be formed of a composition comprised of one or more materials including but not limited to polycarbonate (PC); thermoplastic urethane (TPU), thermoplastic elastomer (TPE), acrylonitrile butadiene styrene (ABS), nylon, metal, silicone rubber, or any combination thereof. For example, the first layer, which is the hardest of the three layers, may be formed of a composition comprised of polycarbonate, a combination of polycarbonate and ABS, nylon, fiber reinforced plastic, and/or metal. The second layer, which is the softest of the three layers, may be formed for example of a composition comprised of TPE, silicone rubber, or combination thereof or other suitable materials. The third layer, which has a hardness between the other two layers, may be formed for example of a composition that has a relatively high resistance to scratching such as a composition comprised of TPU and/or TPE or combination thereof or other suitable material. [0014] Thus it is contemplated that in operation, when there is an impact at the corners, the third layer, which has a high resistance to scratching and a higher hardness than the second layer, distributes the force and to the extent the energy of the force is transferred to the second layer, the second layer can dampen the shock, especially at the impact prone corners, to thereby mitigate the transfer of the impact energy to the device. [0015] One or more of the plurality of protrusions of the first layer may have a first external shape selected from a group consisting of a square, octagon, pentagon, rectangle, triangle, circle, hexagon, and heptagon. Also one or more of the plurality of protrusions may include an aperture residing within the protrusion that defines a first shape selected from a group consisting of a square, octagon, pentagon, rectangle, triangle, circle, hexagon, and heptagon. Also, the plurality of protrusions in the first layer may be dimensioned to be below, above, or flush with the height of the walls of the second layer that surround the protrusions. Thus, some of the plurality of protrusions in the first layer may be dimensioned to be flush with the height of the interconnected walls in the second layer adjacent thereto, some of the plurality of protrusions may be dimensioned to be below the height of the interconnected walls adjacent thereto, and some of the plurality of protrusions may be dimensioned to be above the height of the interconnected walls adjacent thereto. The plurality of protrusions may be comprised of multiple groups of protrusions with each protrusion in each group being equally or unequally spaced from one another or spaced in a defined pattern. The plurality of protrusions may be comprised of a first group configured to reside nearer the top end or side than the bottom end or side, a second group may be configured to reside nearer the bottom end or side than the top end or side, and a third group may be configured to reside an equal distance from the right and left sides. [0016] The number of corner protrusions in the second layer may be two, three, four or more (depending on the number of corners on the mobile device), each of which is configured to reside at one, some or all of the corners of the mobile device or any combination of corners thereof. For example, one corner protrusion may be configured to reside at a corner defined in part by the top side of the mobile device and another corner protrusion may be configured to reside at a corner defined in part by the bottom side. By way of another example, one corner protrusion may be configured to reside at a corner defined in part by the right side of the mobile device and another corner protrusion may be configured to reside at a corner defined in part by the left side of the mobile device. By way of yet another example, a first corner protrusion may be configured to reside at a corner defined in part by the top side of the mobile device (e.g., the intersection between the top side and the right or left side), a second corner protrusion may be configured to reside at a corner defined in part by the bottom side (e.g., the intersection between the bottom side and the right or left side), a third corner protrusion may be configured to reside at a corner defined in part by the right side (e.g., the intersection between the right side and the top or bottom side), and a fourth corner protrusion may be configured to reside at a corner defined in part by the left side (e.g., the intersection between the left side and the top or bottom side). Correspondingly dimensioned corner indentations in the inner surface of the third layer may be provided to engagingly surround or receive one, some or all of the corner protrusions. Thus, some or all of the surfaces that define the indentions on the third layer may be in contact with a corresponding corner protrusion on the second layer. [0017] The corner protrusions may be configured or dimensioned to reside above, below or flush with the height of the mobile device in any combination. For example, one of the corner protrusions may be configured to extend above the height of the mobile device and another of the corner protrusions may be configured to be flush with the height of the mobile device. Alternatively, all of the corner protrusions may be configured to be flush with the height of the mobile device or may be configured to reside below the height of the mobile device. One or all of the corner protrusions may also have uniform or varying dimensions in width and thickness between the base and the apex of the protrusion. For example, the corner protrusions may include a thickness defined between the inner and outer surfaces that varies with the height of the protrusion, such as being thicker (or thinner) at the base of the corner protrusion as compared to the thickness nearer the apex of the corner protrusion. By way of another example, the width generally perpendicular to the thickness may be wider (or narrower) at the base of the corner protrusion as compared to width near the apex of the corner protrusion. [0018] The pattern of elevated interconnected walls of the second layer may be comprised of any arrangement of shapes selected for example from a group consisting of a square, octagon, pentagon, rectangle, triangle, circle, hexagon and heptagon or combination thereof. By way of example, the interconnected walls may be comprised of walls that form hexagons or portions thereof, which together create a honeycomb wall pattern. The apertures in the second layer and the plurality of protrusions of the first layer may also be hexagonal in shape and dimensioned to closely or snugly fit or mate together, so that one, some or all six of the walls that form the mating hexagons are in contact with one another. The pattern of elevated interconnected walls may be contiguous or dis-contiguous, may or may not extend to the perimeter regions of the second layer, may be positioned in discrete regions, or may be spaced apart from one another. Various patterns comprising one or more shapes may be employed alone or in combination with other patterns, such that one region of the inner surface of the second layer may have one pattern and another region of the inner surface of the second layer may have another pattern. The elevated pattern of interconnected walls may be configured in height and construction so as to suspend the back face of the mobile device above the apertures defined by the interconnected walls so that the back face of the mobile device does not bottom-out on (or become in contact with) the recessed inner surface of the second layer. Although not depicted, a pattern of interconnected walls may also be employed on the inner surface of the third layer to create an air-suspension frame around the mobile device at the perimeter and front face regions of the mobile device as well as the one created by the second layer vis-à-vis the back face region. [0019] The second layer may further comprise one or more button protrusions that are dimensioned and configured to extend within one or more of the control apertures of the third layer. Each button protrusion may or may not be co-molded to the perimeter of the control aperture to form an integrated region therewith and may be configured to reside above or over a user control button on the mobile device such as a volume, power, mute, or other user button. [0020] The third layer may also include one or more stability tabs configured to extend underneath the back face of the mobile device. The inner surface of the tab may be in contact with the outer surface of the second layer, while the outer surface of the tab may be exposed externally. The tab may be received within an aperture on the first layer that opens to the perimeter. The aperture may be configured to reside nearer one end of the mobile device than the other and may be configured to reside nearer to one side of the mobile device than the other. Alternatively the aperture and tab may be configured to be centrally positioned relative to one or more sides of the mobile device. [0021] The third layer may also be configured to include a retention rim positioned to reside over the perimeter region of the front face of the mobile device to retain the mobile device within the case. The retention rim may encircle a portion or the entire front face. For example the retention rim may be configured to extend along the top, bottom, left, or right sides of the mobile device or any combination thereof. It is contemplated for example that the rim extend only in the corner regions or regions other than in the corners, or combination of corner and non-corner regions, which may facilitate insertion and removal of the mobile device from the phone. In this respect, the case is configured and constructed with sufficient flexibility to allow the user to install and remove the mobile device within the case without damaging the case or the mobile device. [0022] The second layer may include one or more apertures to allow for functionality and so as to facilitate the intended use of the mobile device. For example, the second layer may include a camera lens aperture that extends there through and is configured to reside around the outside of a camera lens window on the back face of the mobile device. The walls that define the apertures may extend through the first layer and may overlap the outer surface of the third layer. To the extent there is a touchscreen on the back face or other surface region of the mobile device, second and first layer may have an aperture to allow user interaction with that touchscreen. [0023] Methods of manufacturing a protective case that includes one or more of the various foregoing aspects are also disclosed. Manufacturing steps may, for example, include: [0024] (1) co-molding three distinct layers within a mold to form an integrated protective case construct. [0025] (2) molding the first layer defined by first inner and outer surfaces and dimensioned to cover at least a portion of the back face of the mobile device and extend around at least a portion of the perimeter of the mobile device at the back face boundary. The first layer may be molded to include a first plurality of protrusions extending from its inner surface in a direction away from its outer surface and being molded of a material that is harder than each of the second and third layers. [0026] (3) co-molding, around the perimeter regions of the first layer, the third layer defined by third inner and outer surfaces and dimensioned to cover one or more regions of the top, bottom, right and left sides of the mobile device. The third layer may be further molded to include one or more control apertures dimensioned and positioned to allow access to control buttons or ports on the mobile device. The third layer may be further molded to include indentations in its inner surface at regions configured to reside at the corners of the mobile device, the indentations being dimensioned to surround corner protrusions of the second the layer. The third layer may be molded of material that is harder than the second layer. [0027] (4) co-molding, onto the inner surface of both the first and third layers, the second layer defined by second inner and outer surfaces and dimensioned to cover at least a portion of the back face of the mobile device and extend around at least a portion of the perimeter of the mobile device at the back face boundary. The second layer being molded to include a plurality of corner protrusions positioned along the perimeter region of the second layer to correspond in location with corners of the mobile device and dimensioned to extend at, below, or above the height of the mobile device (as measured thereat between the front and back faces). The second layer may be further molded to include a pattern of walls extending from its inner surface a height above and in a direction away from its outer surface. The pattern of walls may form any arrangement of shapes selected for example from a group consisting of a square, octagon, pentagon, rectangle, triangle, circle, hexagon and heptagon or combination thereof. The second layer may further include a plurality of apertures that surround and are in contact with one or more of the protrusions in the first layer. [0028] The various configuration and construction aspects of the three component layers described above or otherwise herein (including as illustrated in the drawings) may be included in the molding process of the layer with any of the foregoing steps, or portions of any of the foregoing steps, in any combination without limitation. [0029] Each of the foregoing and various aspects, together with those set forth in the claims and summarized above or otherwise disclosed herein, including the drawings, may be combined to form claims for a device, apparatus, system, method of manufacture, and/or use without limitation. BRIEF DESCRIPTION OF THE DRAWINGS [0030] These and other features, aspects and advantages are described below with reference to the drawings, which are intended to illustrate but not to limit the invention. In the drawings, like reference characters denote corresponding features consistently throughout similar embodiments. [0031] FIGS. 1A-1F are front face, back face, left side, right side, top side and bottom side views of a protective case for a mobile device with the mobile device received within the case. The mobile device depicted in the illustration is a depiction of an Apple iPhone 5s® mobile phone. [0032] FIG. 2A is a front face view of the protective case illustrated in FIGS. 1A-1F without the mobile device therein. [0033] FIG. 2B is a bottom side view of the protective case illustrated in FIG. 2A . [0034] FIGS. 2C-2D are front and back face perspective views, respectively, of the disassembled protective case illustrated in FIG. 2A showing the three component layers of the case. The perspective views are both taken from the left side. [0035] FIG. 3 is a more detailed partial cross-sectional front face view taken along plane A-A of FIG. 2B showing in greater detail the construction of the case at the bottom end region including the corners and sides thereof and the relationship and configuration of the three integrated component layers. [0036] FIG. 4 is a more detailed partial cross-sectional view of the protective case illustrated in FIG. 2A taken along cross-section line B-B showing in greater detail the construction of the case and the relationship and configuration of the three integrated component layers. [0037] FIG. 5 is a more detailed cross-sectional view of the protective case illustrated in FIG. 2A taken along cross-section line C-C showing in greater detail the construction of the case and the relationship and configuration of the three integrated component layers. [0038] FIG. 6 is a more detailed cross-sectional view of the protective case illustrated in FIG. 2A taken along cross-section line D-D showing in greater detail the construction of the case and the relationship and configuration of the three integrated component layers. [0039] Each drawing is generally to scale and hence relative dimensions of the various layers can be determined from the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0040] As summarized above and illustrated in the drawings, disclosed herein are various aspects of a protective case for a mobile device capable of minimizing bulkiness and weight, yet maintain a high level of protection. Many of those aspects are summarized above and illustrated in the drawings. [0041] Commonly disclosed in FIGS. 1-6 is a protective enclosure or case 200 for a mobile device 100 that illustrate, by way of example, various configuration and construction aspects of the case. In this particular implementation, the case is configured for an Apple iPhone 5s mobile or smart phone device. It should be understood, however, that the case may be configured for any mobile device or electronic device, including but not limited to portable or cellular phones, PDAs, gaming devices, laptop computers or tablet devices. [0042] As best depicted in FIGS. 1A-1F , the mobile device 100 includes front and back faces 110 and 120 , and a left side 130 , a right side 140 (hidden from view), a top side 150 , and a bottom side 160 that together define the perimeter 170 of the mobile device 100 . The front and back faces are flat and the sides have flat surfaces that extend between the front and back faces 110 , 120 and the distance between the front and back faces 110 , 120 define the height of the device 100 . Corner regions 180 are defined at the curved regions where the sides intersect with one another. The front face 110 includes a touchscreen 112 user interface, a home button 114 with biometric sensor (surround the home button), speakers, a front facing camera, and proximity sensors 116 , 117 , and 118 (located at the top end region on the front face of the phone) that are not shown in the illustrations, but well known to one of ordinary skill in the art. The back face 120 includes a camera lens window 122 , a flash 124 , and a microphone 125 that are grouped together in the upper corner on the right side of the phone 100 . The left side 130 includes volume control buttons 132 (hidden below the corresponding case + and − buttons) and ringer silent switch 134 that controls whether or not the phone is on silent mode. The top side 150 includes a depressible power button 152 (also hidden behind the corresponding power button 254 on the case). The bottom side 160 includes a headphone jack 162 , microphone grill 164 , and a data and charging port 166 . [0043] Generally, the protective case 200 includes front and back face walls 210 and 220 and left side and right side walls 230 and 240 and top side and bottom side walls 250 and 260 . The side walls, 230 , 240 , 250 , and 260 reside between the front and back faces. Each of the walls 210 , 220 , 230 , 240 , 250 , and 260 are dimensioned to correspond in dimension to the front and back faces, and left, right, top and bottom sides 110 , 120 , 130 , 140 , 150 , and 160 of the mobile device 100 , respectively. [0044] More specifically, the front face wall 210 is defined by inner and outer surfaces 211 and 212 and includes an inwardly projecting rim 214 (best illustrated in the cross-sectional views of FIGS. 5 and 6 ). The back face wall 220 is also defined by inner and outer surfaces 221 and 222 and includes a camera lens and flash opening or aperture 224 extending there-through. [0045] The left side and right side walls 230 and 240 are also each defined by inner and outer surfaces 231 , 232 and 241 , 242 , respectively. The left side wall 230 further includes volume control buttons 234 that are positioned, dimensioned, configured and adapted to interface and actuate the volume control buttons 132 on the mobile device 100 . Also included in the left side wall 230 is an opening or aperture 236 that is positioned and dimensioned to correspond with the ringer silent switch 134 of the mobile device 100 to provide functional user access to the switch 134 . The right side wall 240 does not include any apertures or control buttons as none are provided on the Apple iPhone 5s mobile device for which the case is configured to protect. However, it is contemplated that it may include either apertures and/or buttons to provide access or control over corresponding ports or buttons on the mobile device should the device have controls or ports on that side. It should be understood however, that the number of apertures can vary (increase or decrease) and their placement vary to correspond with controls on the mobile device. [0046] The top side and bottom side walls 250 and 260 are also each defined by inner and outer surfaces 251 , 252 and 261 , 262 respectively. The top side wall 250 includes a mobile device power button 254 positioned, dimensioned, configured, and adapted to interface with the power button 152 on the mobile device 100 . In the implementation illustrated the button 254 resides within an aperture 255 and is connected thereto. For example, the button 254 may be connected in a levered manner 256 to top side wall 250 at one end or at a mid-section of the aperture 255 , such that when pressed, the button 254 hinges around the lever connection. The bottom side wall 260 includes perforated regions 264 positioned and dimensioned to correspond with the microphone grill 164 regions on the mobile device 100 . The bottom side wall 260 further includes a headphone jack and data/charging port apertures 266 and 267 that are positioned and dimensioned to correspond with the headphone jack port 162 and the data and charging port 166 , respectively. Collectively the side walls 230 , 240 , 250 and 260 define a perimeter 270 between the front and back faces 210 and 220 of the protective case 200 . [0047] The case 200 is formed of a multilayered construction that includes three layers 300 , 400 and 500 that are co-molded together to form a unitary integral construct. Various aspects of these layers and their inter-relationship, construction and manufacture are described in more detail. [0048] As best illustrated in FIGS. 2C-2D , the first layer 300 is defined by first inner and outer surfaces 310 , 311 , respectively, and dimensioned to cover the back face 120 of the mobile device 100 . The first layer 300 is configured to extend to the perimeter 170 of the mobile device 100 at the back face 120 boundary, which is the perimeter defined by the intersection of the side walls (e.g., 130 , 140 , 150 and 160 ) and the back face 120 of the mobile device 100 . The first inner surface 310 includes a first plurality of protrusions 320 (best illustrated in FIGS. 2A and 2C ) extending generally in a direction away from the outer surface 311 of the first layer 300 . [0049] The second layer 400 is defined by second inner and outer surfaces 410 , 411 respectively, and is also dimensioned to cover the back face 120 of the mobile device and extend around the perimeter 170 of the mobile device 100 at the back face 120 boundary. The second layer 400 further includes a plurality of corner protrusions 420 positioned along the perimeter region of the second layer 400 to correspond in location with the corners 180 of the mobile device 100 . The corner protrusions 420 are dimensioned to reside at a height that is slightly below the height of the mobile device 100 at the corners 180 . However, it is contemplated, that one, some or all of the corner protrusions 420 may extend at, below, or above the height of the mobile device 100 in any combination. The second layer 400 may further include an elevated pattern of interconnected walls 430 extending from the second inner surface 410 a height above and in a direction away from the second outer surface 411 . Also included in the second layer 400 is a plurality of apertures 440 extending into the second outer surface 411 , such that one or more of the apertures 440 are dimensioned and positioned to surround (e.g., in close proximity and firm contact) one or more of the protrusions 320 of the first layer 300 . [0050] The first and second layers 300 , 400 may be configured to cover the entire, a majority, half or less than half of the back face 120 of the mobile device 100 and may be configured to extend to or around the entire, a majority, half or less than half of the perimeter 170 of the mobile device 100 at the back face 120 boundary. [0051] In the illustrated implementation, the first layer 300 is configured to cover nearly the entire back face 120 of the mobile device 100 , with the exception of the flash and camera lens window aperture 224 and nearly the entire perimeter 170 of the back face 120 with the exception of the tab aperture 350 , described in more detail below. It should be understood however, that alternative configurations may be employed. For example, interposed or intervening regions, such as those between the protrusions 320 and/or apertures 440 , may be removed from the first and/or second layers 300 , 400 while perimeter regions of the first and/or second layers 300 , 400 may be maintained. Perimeter regions in the first and/or second layers 300 , 400 that reside between one or more of the corners may be removed. Mid-section regions of the layers 300 and 400 may be removed to allow for access to, or user utilization of, user controls, additional touchscreen interface, and/or other device features (e.g., speakers, cameras, lights, microphone, etc.) that are located on the sides walls 130 , 140 , 150 , 160 and/or back face 120 of the mobile device 100 . [0052] Additionally, while the pattern of walls 430 in the second layer 400 is illustrated as being interconnected and elevated, it should be understood that the walls may be disconnected at one or more locations or in discrete regions. Also, while the pattern of walls 430 are illustrated as having a generally uniform height or elevation, it should be understood that the walls 430 may have differing heights at discrete regions within the pattern or within or at specific walls or wall segments within the pattern of walls 430 . [0053] The third layer 500 is also defined by third inner and outer surfaces 510 , 511 , respectively. The third layer 500 is generally dimensioned to cover the top, bottom, right and/or left sides 130 , 140 , 150 , 160 of the mobile device 100 and forms the inwardly projecting rim 214 of the front face wall 210 . While in the illustrated embodiment, the third layer 500 extends around the entire perimeter of the mobile device 100 , it may be configured elsewise. Thus it is contemplated that the third layer 500 may cover the entire, a majority, half or less than half of the top, bottom, right and/or left sides of the mobile device 100 and/or may be configured to extend around less than the entire, a majority, half or less than half of the perimeter 170 of the mobile device 100 in any combination. Thus, for example the third layer may cover the corners of the mobile device alone or may cover the corners of the mobile device with and only a portion of one or more of the sides extending there-between. The third layer 500 includes one or more mobile device 100 control apertures 530 that extend through the layer that are dimensioned and positioned to allow access (or flow through with respect to speakers and the like) to control buttons or ports (e.g., power button 152 , volume button 132 , ringer silent switch 134 , headphone jack 162 , microphone grill 164 , and data/charging port 166 ) on the mobile device 100 . The third layer also further includes one or more indentations 540 in the third inner surface 510 at regions configured to reside at the corners 180 of the mobile device 100 . The indentations 540 are configured to be in the negative image of the corner protrusions or otherwise dimensioned to receive one or more of the plurality of corner protrusions 420 of the second layer 400 . [0054] While, the first, second, and third layers 300 , 400 , 500 may be co-molded to form an integrated construction, it should be understood that it is contemplated that only portions of one or more of the layers may be co-molded, or each of the layers may be separately formed and mechanically attached to one another by clips, snaps or latches between each of the components or between for example the third layer and the first layer. A combination of co-molding and mechanical attachment of the layers or portions thereof may also be employed. In a fully integrated or co-molded construction the case 200 would be properly dimensioned and have sufficient flexibility to allow the user to insert and remove the mobile device 100 without damage to the case 200 . When the components are modular or separable from one another, the user may wrap the second layer around the mobile device 100 and then clip the first and third layers in position around the device 100 . The clips, snaps or hooks or other mechanical attachments be formed or molded into: (a) two or more of the layers at their perimeter regions, (b) the protrusions 320 and apertures 440 of first and second layers 300 , and 400 , (c) one or more of the corner protrusions 420 and indentions 540 in the second and third layers 400 , 500 , (d) the control buttons 234 and corresponding apertures 530 on the second and third layers 400 , 500 and/or (e) at any region where two or more layers are in contact or proximity to one another. Thus, a combination of co-molding and/or mechanical attachment of the layers may be employed. One or more of the layers may be adhesively attached or otherwise bonded to one another. [0055] The materials that form the layers may be selected based on their hardness. For example, the first layer 300 may be made of a first material that has a first hardness, the second layer 400 may be made of a second material that has a second hardness that is different from the first layer, and the third layer 500 may be made of a third material that has a third hardness that is different from the first or second hardness. In a preferred implementation, the first hardness is greater than the third hardness and the third hardness is greater than the second hardness. [0056] The first, second and third layers 300 , 400 , 500 may be formed of a composition comprised of one or more materials including but not limited to polycarbonate; thermoplastic urethane (TPU), thermoplastic elastomer (TPE), acrylonitrile butadiene styrene (ABS), nylon, metal, silicone rubber, or any combination thereof. For example, the first layer 300 , which is the hardest of the three layers, may be formed of a composition comprised of polycarbonate, a combination of polycarbonate and ABS, nylon, fiber reinforced plastic, and/or metal. The second layer 400 , which is the softest or least hard of the three layers, may be formed for example of a composition comprised of TPE, silicone rubber, or combination thereof or other suitable materials. The third layer 500 , which has a hardness between the other two layers, may be formed, for example, of a composition comprised of TPU and/or TPE or combination thereof or other suitable material. The second layer may be an elastic material. [0057] The first layer 300 may have a Shore A durometer hardness that is 50% or more greater than the third layer 500 , 40% or more greater than the third layer 500 , 30% or more greater than the third layer, 20% or more greater than the third layer, or 10% or more greater than the third layer all +/−5% as measured using the American Society for Testing and Materials (ASTM) standard D2240. The first layer may have a Shore A durometer hardness of 100+/−15, 100+/−10, or 100+/−5, or 100 as measured using the American Society for Testing and Materials (ASTM) standard D2240. The second layer 400 may have a Shore A durometer hardness of 45+/−15, 45+/−10, 45+/−5, or 45 as measured using the American Society for Testing and Materials (ASTM) standard D2240. The third layer may have a Shore A durometer hardness of 65+/−15, 65+/−10, 65+/−10, or 65 as measured using the American Society for Testing and Materials (ASTM) standard D2240. The third layer may also, for example, have a Shore A durometer hardness that is 40% or more greater than the second layer, 30% or more greater than the second layer, 20% or more greater than the second layer, or 10% or more greater than the second layer all +/−5% as measured using the American Society for Testing and Materials (ASTM) standard D2240. It should be understood that the three layers may have a Shore A hardness that is comprised of any combination of hardness described above consistent with the teachings herein. [0058] In the illustrated embodiment the protrusions 320 have a hexagonal external and internal shape. However, it should be understood that other shapes may be employed. For example, one or more or all of the plurality of protrusions 320 of the first layer 300 may have a first external shape selected from a group consisting of a square, octagon, pentagon, rectangle, triangle, circle, hexagon, and heptagon. One or more or all of the plurality of protrusions 320 may each include an aperture 321 residing therein that defines an internal shape selected from a group consisting of a square, octagon, pentagon, rectangle, triangle, circle, hexagon, and heptagon. One or more or all of the plurality of protrusions 320 may be dimensioned so that the upper surface 322 to be below, above, or flush with the upper surface 422 height of the interconnected walls 430 of the second layer 400 surrounding the protrusions 320 of the first layer 300 . Thus, some or none of the plurality of protrusions 320 may be dimensioned to be flush with the height of the interconnected walls 430 adjacent thereto (as shown in the drawings), some or none of the plurality of protrusions 320 may be dimensioned to be below the height of the interconnected walls 430 adjacent thereto, and some or none of the plurality of protrusions 320 may be dimensioned to be above the height of the interconnected walls 430 adjacent thereto. The plurality of protrusions 320 may be comprised multiple groups of protrusions with each protrusion 320 in each group being equally spaced from one another. The plurality of protrusions may be comprised of a first group configured to reside nearer the top end side 250 than the bottom end side 260 , a second group may be configured to reside nearer the bottom end side 260 than the top-end side 250 , and a third group may be configured to reside an equal distance from the right and left sides 230 and 240 . One or more protrusions may be positioned in each corner region, the mid region and/or nearer the perimeter than the middle of the case. [0059] The number of corner protrusions 420 in the second layer 400 may be selected from a group consisting of two, three, and four (or more if mobile device has more than four) configured to reside at one, some or all of the corners 180 of the mobile device 100 or any combination of corners thereof. For example, one corner protrusion 420 may be configured to reside at a corner 180 defined in part by the top side 150 of the mobile device 100 and another corner protrusion 420 may be configured to reside at a corner defined in part by the bottom side 160 . By way of another example, one corner protrusion 420 may be configured to reside at a corner 180 defined in part by the right side 140 of the mobile device 100 and another corner protrusion 420 may be configured to reside at a corner 180 defined in part by the left side 130 of the mobile device 100 . By way of yet another example, a first corner protrusion 420 may be configured to reside at a corner 180 defined in part by the top side 150 of the mobile device 100 , a second corner protrusion 420 may be configured to reside at a corner 180 defined in part by the bottom side 160 , a third corner protrusion 420 may be configured to reside at a corner 180 defined in part by the right side 140 , and a fourth corner protrusion 420 may be configured to reside at a corner 180 defined in part by the left side 130 . Corresponding dimensioned corner indentations 540 in the third layer 500 may be provided to engagingly receive one, some or all of the corner protrusions 420 . Thus, some or all of the surfaces that define the indentions on the third layer may be in contact with corresponding surfaces of the corner protrusions 420 on the second layer 400 . In this respect, the corner indentations 540 may be configured to have a reverse image of the desired shape of the corner protrusions 420 . [0060] The corner protrusions 420 may be configured or otherwise dimensioned to reside above, below or flush with the height of the mobile device 100 , in any combination. For example, one of the corner protrusions 420 may be configured to extend above the height of the mobile device 100 and another of the corner protrusions 420 may be configured to be flush with the height of the mobile device 100 . Alternatively, all of the corner protrusions 420 may be configured to be flush with the height of the mobile device 100 or may be configured to reside below or above the height of the mobile device 100 . The corner protrusions 420 may also have uniform or varying dimensions in width (best illustrated in FIG. 4 ) and thickness (best illustrated in FIG. 3 ) between the base 421 and the apex 422 of the corner protrusion 420 . For example, the corner protrusions 420 may include a thickness defined between the inner and outer surfaces that varies with the height (as measured from the base 421 to the apex 422 ) of the protrusion 420 , such as being thicker (or thinner) at the base 421 of the corner protrusion 420 as compared to the thickness nearer the apex 422 of the corner protrusion 420 . By way of another example, the width, which is generally perpendicular to the thickness, may be wider (or narrower) at the base 421 of the corner protrusion 420 as compared to width near the apex 422 of the corner protrusion 420 . For example, in the illustrated embodiment the thickness of the corner protrusions at the apex is 1.09 millimeters and at the base is 1.14 millimeters. [0061] In the illustrated embodiment the pattern of elevated interconnected walls 430 employ a repeating hexagonal external and internal shape. However, it should be understood that other shapes may be employed. For example, the pattern of elevated interconnected walls may be comprised of any pattern including any arrangement of shapes such as a square, octagon, pentagon, rectangle, triangle, circle, hexagon or heptagon or combination thereof. It is also contemplated that the walls may be arranged in a random pattern. It is also contemplated that the walls 430 may have a greater density in number or composition in one region versus another. For example an increased or decreased density (either in composition or in number of the walls) may be employed around or near apertures. [0062] In the illustrated embodiment, the interconnected walls 430 are oriented into hexagonal formations (or portions of a hexagonal formation) that together create a honeycomb wall pattern. The honeycomb pattern may be uniform or non-uniform. The apertures 440 in the second layer 400 and the plurality of protrusions 320 of the first layer 300 have corresponding hexagonal shapes that are dimensioned to snugly mate together, so that one, some or all six of the hexagonal walls are in contact with one another. The pattern of elevated interconnected walls 430 may, as previously noted, be contiguous or dis-contiguous, and may or may not extend to the perimeter regions of the second layer 400 , may be positioned in discrete regions, or may be spaced apart from one another. Various patterns comprising one or more shapes may be employed alone or in combination with other patterns. The elevated pattern of interconnected walls 430 may be configured in height and construction so as to suspend the back face of the mobile device above the apertures 321 defined by one or more of the interconnected walls 430 so that the back face 120 of the mobile device 100 does not bottom-out on the recessed inner surface 410 of the second layer 400 . [0063] The second layer 400 may further comprise one or more button protrusions 450 that are dimensioned and configured to extend within one or more of the control apertures 530 of in the third layer 500 . Each button protrusion 450 may or may not be co-molded to the corresponding control aperture 530 to form an integrated region therewith. The button protrusions are generally configured to reside above a user control button on the mobile device 100 such as a volume 132 , power 152 , mute, or other user buttons. [0064] The third layer 500 may also further include one or more retention or stability tabs 550 configured to extend underneath the back face 120 of the mobile device 100 . The inner surface of the tab may be in contact with the outer surface of the second layer, while the outer surface of the tab may be exposed externally. The tab 550 may be received within an aperture 350 on the first layer 300 that opens to the perimeter. The tab and aperture 550 and 350 may be configured to reside nearer one end of the mobile device 100 than the other and may be configured to reside nearer to one side of the mobile device than the other. [0065] The third layer 500 may also be configured to include retention rim 214 positioned to reside over the perimeter region 170 of the front face 110 of the mobile device 100 to assist in retaining the mobile device 100 within the case 200 . The retention rim 214 may encircle a portion or the entire front face 110 . For example the retention rim 214 may be configured to extend at the top, bottom, left and/or right sides (at the corners or along the sides thereof) of the mobile device in any combination thereof. [0066] The case 200 is configured and constructed with sufficient flexibility to allow the user to install and remove the mobile device 100 within the case without damaging the case or the mobile device. The flexibility may be implemented via the construction materials employed and the configuration of the layers or components. [0067] A method of manufacturing the protective case 200 for a mobile device is also disclosed. The manufacturing process may include the steps of: [0068] (1) co-molding three layers to form an integrated protective case construct. [0069] (2) molding the first layer defined by first inner and outer surfaces and dimensioned to cover at least a portion of the back face of the mobile device and extend around at least a portion of the perimeter of the mobile device at the back face boundary. The first layer is molded to include a first plurality of protrusions extending from the inner surface of the first layer in a direction away from its outer surface and being molded of a material that is harder than either the second or third layers. [0070] (3) co-molding, around the perimeter regions of the first layer, the third layer defined by third inner and outer surfaces and dimensioned to cover one or more regions of the top-end, bottom-end, right and left sides of the mobile device. The third layer is molded to include one or more control apertures dimensioned and positioned to allow access to control buttons or ports on the mobile device. The third layer being further molded to include indentations in its inner surface at regions configured to reside at the corners of the mobile device, the indentations being dimensioned to receive corner protrusions molded into the second the layer. The third layer being molded of material that is harder than the second layer. [0071] (4) co-molding, onto the inner surface of the first and third layers, the second layer defined by second inner and outer surfaces and dimensioned to cover at least a portion of the back face of the mobile device and extend around at least a portion of the perimeter of the mobile device at the back face boundary. The second layer is molded to include a second plurality of corner protrusions positioned along the perimeter region of the second layer to correspond in location with corners of the mobile device and dimensioned to extend at, below, or above the height of the mobile device. The second layer being further molded to include a pattern of walls extending from its inner surface a height above and in a direction away from its outer surface, and a plurality of apertures that surround and are in contact with one or more of the first group of protrusions in the first layer. The pattern of walls may form any arrangement of shapes selected for example from a group consisting of a square, octagon, pentagon, rectangle, triangle, circle, hexagon and heptagon or combination thereof. [0072] The various aspects relating to configuration and construction of each of the three component layers described above or otherwise herein and/or illustrated in the drawings may be included in the molding process of the layer with any of the foregoing steps, or portions of any of the foregoing steps, in any combination without limitation. [0073] Each of the foregoing and various aspects, together with those set forth in the claims and described in connection with the embodiments of the protective cases summarized above or otherwise disclosed herein including the drawings may be combined to form claims for a device, apparatus, system, method of manufacture, and/or use without limitation. [0074] Although the various inventive aspects are herein disclosed in the context of certain preferred embodiments, implementations, and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, while a number of variations of the various aspects have been shown and described in detail, other modifications, which are within their scope will be readily apparent to those of skill in the art based upon this disclosure. It should be also understood that the scope this disclosure includes the various combinations or sub-combinations of the specific features and aspects of the embodiments disclosed herein, such that the various features, modes of implementation, and aspects of the disclosed subject matter may be combined with or substituted for one another. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments or implementations described above, but should be determined only by a fair reading of the claims. [0075] Similarly, this method of disclosure, is not to be interpreted as reflecting an intention that any claim require more features than are expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment.

A protective case for a mobile device having a multi-layered construction is disclosed. The multi-layered construction includes three layers that are co-molded to one another and is capable of being lightweight and low-profile, yet provide a high level of impact protection. The first layer generally forms the external back face surface of the case, the third layer generally forms the perimeter bumper of the case and the second layer forms the internal liner of the case and includes an elevated pattern of walls upon which the back face of the mobile device rest upon. The first layer is comprised of material that has a hardness greater than the other two layers. The third layer is comprised of a material that has a hardness that is greater than the second layer. The layers are configured to interact with one another so that they are capable of distributing and absorbing impact forces to mitigate damage to the mobile device.

CROSS-REFERENCE This application is a continuation application of U.S. Ser. No. 12/029,113, filed on Feb. 11, 2008, now U.S. Pat. No. 7,635,759, issued Dec. 22, 2009, which is a continuation of U.S. Ser. No. 10/830,702, filed Apr. 23, 2004, now U.S. Pat. No. 7,329,743, issued Feb. 12, 2008, which is a divisional application of U.S. Ser. No. 09/659,521, filed Sep. 12, 2000, now U.S. Pat. No. 6,727,080, issued Apr. 27, 2004, which is a continuation of PCT/US99/05365, filed Mar. 11, 1999, which is a continuation-in-part of U.S. Ser. No. 09/040,485 filed Mar. 17, 1998, now U.S. Pat. No. 6,166,176, issued Dec. 26, 2000. SEQUENCE LISTING The instant application contains a Sequence Listing which has been submitted via EFS-Web and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Dec. 8, 2009, is named 38964701.txt, and is 10,436 bytes in size. The invention relates to a gene encoding a protein and peptides therefrom that includes an epitope, a cancer associated antigen, useful as a marker that is not restricted to previously defined histological classes of cancer. Antigenic peptides are useful as a vaccine for treatment and prevention of cancer. Antigenic peptides are useful as a vaccine for treatment and prevention of cancer, and for the preparation of new, specific, monoclonal antibodies. Antisense molecules are useful in pharmaceutical compositions and are useful for diagnosis and treatment. BACKGROUND OF THE INVENTION Cancer 1 is a leading cause of death in men and women throughout the world. In the United States alone, over 1 million new cases are diagnosed each year, and over 0.5 million deaths are reported annually (Landis, et al., 1998). Historically, tumors are grouped and treated, based in part by the tissues in which they arise, e.g.: breast cancer, colon cancer, and lung cancer, and the like. Yet, within lung cancer, for example, it is well recognized that these tumors are a very heterogeneous group of neoplasms. This is also true for tumors arising in other tissues. In part, because of this heterogeneity, there are complex and inconsistent classification schemes which are used for human tumors. Previous attempts to treat cancer have been hampered by: 1) the arbitrary classification of tumors arising within given tissues, and 2) by using microscopic methods based on how these tumors look (histological classification). Although existing classifications for various tumor types have some prognostic value, almost all of the classifications fail to predict responsiveness to treatments and likelihood of cure or disease course. Improved classification schemes based on the biological constitution of these neoplasms is required to significantly alter the survival statistics of humans who have cancer. One approach to solving these problems is to locate molecules specific to tumors, preferably antigens in molecules that are markers for cancer cells. (A “marker” is defined herein as any property which can be used to distinguish cancer from normal tissues and from other disease states.) The markers' presence is then a basis for classification. 1 Terminology used herein is as follows: “cancer” is a malignant tumor, wherein a “tumor” is an abnormal mass of tissue, that need not be malignant. “Neoplasm” is a form of new growth. Monoclonal antibodies (MCAs) prepared by somatic cell hybridization techniques, usually in mice, are useful molecular probes for the detection and discrimination of cellular antigens, and therefore have great potential for detecting cancer associated antigens. These antibodies bind to specific antigens and the binding is detectable by well known methods. When binding occurs, the inference is made that a specific antigen is present. Those cancer associated antigens which are exposed to the cell surface or found in the cancer mass, are molecular targets for the immune systems (including host antibodies) of the host. Recent findings suggest that cancer patients who have antibodies against their tumors, do better than those who do not mount this type of immune response (Livingston, et al., 1994). Therefore, natural, induced, or administered antibodies are a promising therapeutic approach. The humanization of non-human MCAs (the process by which non-human MCA reactive sites are shuttled into cloned human antibodies and expressed) results in reduced immunogenicity of the foreign antibodies without the loss of their specific binding in in vivo and in ex vivo applications. MCAs can be used as in vivo imaging agents, diagnostic tests, and for therapy (Radosevich, et al. 1988, 1990; Rosen, et al. 1988). Vaccine therapy is a well established approach directed at inducing an immune response without exposure to the causative agent of a disease or condition. Many vaccines are available, for example, to stimulate a response in a host to bacterial and viral agents. The use of tumor associated antigens (markers) in a vaccine could prevent primary cancer occurrence, and could also provide a means to prevent recurrence of the disease. Gene therapy is a means by which the genetic make-up of cells is modified to express the gene of interest. There are many forms of gene therapy including: gene replacement, antisense suppression therapy, and surrogate gene expression. Discovering genes encoding cancer-associated, preferably cancer-specific antigens (markers) opens the door to genetic intervention against cancer cell proliferation. The accurate and consistent use of a cancer marker to differentiate cancerous from normal tissue, not only has diagnostic potential, but is also desirable for treatment and prognosis. Therefore, such markers have been sought. Recent studies have shown that the enzyme encoding human aspartyl beta-hydroxylase (HAAH) is overexpressed in some human adenocarcinoma cell lines, and in primary hepatocellular cancers, therefore could be a marker. The gene said to encode HAAH has been cloned and sequenced (Gronke, et al., 1989, 1990; Wang, et al., 1991; Jia, et al., 1992, 1994; Korioth, et al., 1994; Lavaissiere, et al., 1996). However, little is known about HAAH expression in human tumors in general (Lavaissiere, et al., 1996). The study of the HAAH enzyme grew out of the study of its bovine counterpart (Gronke, et al., 1989, 1990; Wang, et al., 1991; Jia, et al., 1992). Bovine aspartyl beta-hydroxylase is an intracellular, glycosylated protein, localized in the rough endoplasmic reticulum. The protein has been reported to have three major species of molecules; a 85 kilodalton form, and two active forms with molecular weights of 56 and 52 kilodaltons respectively (Lavaissiere, et al., 1996). Using standard biochemical methods, bovine aspartyl beta-hydroxylase (bAAH) has been purified and characterized (Gronke, et al. 1990; Wang, et al., 1991). The activity of the enzyme has been shown to be correlated with the 52 and 56 kilodalton species which were purified Immunologically, a related higher molecular weight form (85-90 kilodalton) was also observed. As part of the purification, bAAH is bound to Con A sepharose, which is consistent with the conclusion that the enzyme is glycosylated. (Subsequent reports on the DNA sequence show three possible glycosylation sites, with one site being very close to the known active enzyme domain.) The protein is very acidic in nature, and a detergent is not required to solubilize the active fraction. The active enzyme site is dependent from the biochemically isolated bovine protein (bAAH) on the presence of histidine at position 675 (Jia, et al., 1994). A partial amino acid sequence was obtained for HAAH. DNA probes (a DNA probe is a molecule having a nucleotide sequence that is capable of binding to a specified nucleotide sequence) deduced from this amino acid sequence was used to screen a bovine cDNA library (Jia, et al., 1992). (A cDNA library contains the sections of DNA that encode for gene products, e.g. peptides, as opposed to genomic DNA). Several overlapping cDNA sequences in the library contained a 754 amino acid open reading frame (ORF) sequence which would be expected to encode an 85 kilodalton protein. Also present in this ORF sequence were two other possible start codons, that is, locations at which encoding begins. The most 3′ start codon was preceded by a ribosome binding site. Translation of the clone having this sequence resulted in a protein that was about 85 kilodaltons. Antiserum was raised to the membrane fraction of human MG-63 cells and was used to immunoscreen a cDNA library made from MG-63 cells. Data on one clone was reported which could encode a 757 amino acid protein, and, by sequence analysis, was found to have strong N-terminal homology with bAAH (Korioth, et al., 1994). When this clone was used in an in vitro translation system (an artificial cocktail of normal cell cytoplasm used to convert mRNA into protein), a 56 kilodalton protein was produced. It was suggested that this was due to posttranslational cleavage. The HAAH enzyme is responsible for the modification of specific aspartic acid residues within the epidermal growth factor-like domains of proteins. It has been hypothesized that these modified aspartic acid residues allow the epidermal growth factor-like domains to become calcium binding domains (Gronke, et al., 1989, 1990; Wang, et al., 1991; Jia, et at, 1992, 1994; Korioth, et al., 1994; Lavaissiere, et al., 1996). An enzyme related to HAAH, aspartyl beta-hydroxylase (AAH), was first studied because it specifically modified select aspartic acid or asparagine residues in a group of biologically important proteins including the vitamin K-dependent coagulation factors VII, IX, and X. Other proteins like C, S, and Z also have this modification (Gronke, et al., 1989, 1990; Wang, et at, 1991; Jia, et al., 1992, 1994; Korioth, et al., 1994; Lavaissiere, et al., 1996). Aspartic acid and asparagine residues have been shown to be modified by HAAH in proteins containing epidermal growth factor-like domains. The function of the beta-hydroxyaspartic and beta-hydroxyasparagine residues is unknown, however, it has been speculated that this modification is required for calcium binding in the epidermal growth factor EGF-like domains of selected proteins. Antibodies were raised to human hepatocellular carcinoma FOCUS cells (Lavaissiere, et at, 1990). One MCA reacted with an antigen that was highly expressed in hepatocellular carcinomas (Lavaissiere, et al., 1996). Immunoscreening using this antibody and a lambda gt11 HepG2 library resulted in the isolation of a partial cDNA, which was subsequently used to isolate a larger clone. A human adenocarcinoma cell line designated A549 was reported as having very high levels of HAAH activity (Lavaissiere, et al., 1996). A mouse monoclonal antibody designated 1.1 MCA 44-3A6 (U.S. Pat. No. 4,816,402) was produced against the human adenocarcinoma cell line A549 (ATCC accession number CCL 185) (Radosevich, et al., 1985). The antibody recognized a cell surface, non-glycosylated antigenic protein having an estimated apparent molecular weight of 40 kDa). The antigen was expressed by A549 cells, and was found to be a good adenocarcinoma marker; that is, it was frequently expressed by cancers which looked like adenocarcinomas when examined histologically (Radosevich, et al., 1990a; Lee, et al., 1985). MCA 44-3A6 is unique in that it is the first monoclonal antibody which has this binding specificity. The results from an International Workshop for Lung cancer confirmed other related published findings on MCA 44-3A6 (Stahel, 1994). The antibody designated MCA 44-3A6 has clinical utility because it differentiates antigens associated with adenocarcinomas. The normal and fetal tissue distribution of the antigen is restricted to some glandular tissues (Radosevich, et al., 1991). Detection can occur on formalin fixed-paraffin embedded tissue (Radosevich, et al., 1985, 1988, 1990a, 1990b; Lee, et al., 1985, 1986; Piehl, et al. 1988; Combs, et al., 1988b, 1988c; Banner, et al., 1985). The antibody has a restricted binding pattern within human pulmonary tumors (Lee, et al., 1985; Banner, et al., 1985; Radosevich, et al., 1990a, 1990b). In a study of over two hundred pulmonary cancers, MCA 44-3A6 was found to react with all of the adenocarcinomas tested, many of the large cell carcinomas, as well as with subsets of intermediate neuroendocrine small cell lung cancers, well-differentiated neuroendocrine small cell carcinomas, carcinoids, but not mesotheliomas. MCA 44-3A6 does not react with squamous cell carcinoma, bronchioloalveolar carcinoma, or small cell carcinoma (Lee, et al., 1985). MCA 44-3A6 is useful in distinguishing adenocarcinomas that are metastatic to the pleura from mesothelioma (Lee, et al., 1986). The antibody has selected reactivity among adenocarcinomas and in large cell carcinomas (Piehl, et al., 1988; Radosevich, et al., 1990b). In a study of over 40 cases of lung cancer comparing cytological and histological findings, MCA 44-3A6 was found to be useful in cytological diagnosis and was consistent with the histological finding (Banner, et al., 1985). Histology is the study of tissues (which are made of cells). Cytology is the study of cells which have been removed from the organizational context which is commonly referred to as tissue. Cells removed from tissues do not always behave the same as if they were in the tissue from which they were derived. Fortunately, the antigen detected by MCA 44-3A6 expressed in adenocarcinoma cells in tissue behaves in the same ways as adenocarcinoma cells removed from tissues. This is a very diagnostically important characteristic. Similar correlations using cytologically prepared cell blocks of pulmonary carcinomas, as well as ACs presenting in body fluids from other sites throughout the body were demonstrated (Lee, et al., 1985; Spagnolo, et al., 1991; Combs, et al., 1988c). Also, MCA 44-3A6 binds to adenocarcinomas from sites other than lung cancer. The expression of the antigen in primary and metastatic lesions was also reported (Combs, et al., 1988a). The utility of the MCA antibody in differentiating cancer from benign lesions in human breast tissue was also noted (Duda, et al., 1991). The cellular localization of the antigen detected by MCA 44-3A6 was determined. By using live cell radioimmunoassays (a radioactive antibody test directed at determining binding of the antibody to live cells), immunofluorescence, and live cell fluorescence activated cell sorter (FAGS) analysis, the antigen detected by MCA 44-3A6, was shown to be on the outside surface of the cell (Radosevich, et al., 1985). Additional studies using immunogold-electron microscopy and FACS analysis have demonstrated that this antigen is non-modulated (that is not internalized by the cancer cell when bound by an antibody), is expressed on the extracellular surface of the plasma membrane, and is not cell cycle specific that is, the cell makes protein all the time it is going through the process of cell replication, and also when it is not dividing (Radosevich, et al., 1991). The antigen is not found in the serum of normal or tumor bearing patients, and is not shed into the culture media by positive cell lines (that is, cancer cells are known to bleb off portions of their cell membranes and release them into the surrounding fluid.) (Radosevich, et al., 1985). Recently 3 of 27 randomly tested adenocarcinoma patients were found to have naturally occurring antibodies to the antigen. In addition, radiolabeled MCA 44-3A6 was used to localize A549 tumors growing in nude mice. A douxorubicin immunoconjugate MCA 44-3A6 is selectively toxic in vitro (Sinkule, et al., 1991). Determination of the nucleotide and amino acid sequences of the antigen detected by MCA 44-3A6 would enhance the usefulness of this antigen in cancer diagnosis, treatment and prevention SUMMARY OF THE INVENTION The antigen detected by the antibody MCA 44-3A6 as described in the Background is now designated as “Labyrinthin.” A gene (designated labyrinthin; abbreviated lab) characterized by a unique nucleotide sequence that encodes the antigen detected by MCA 44-3A6 was isolated and characterized. (lab notation signifies the nucleic DNA/RNA forms; “Lab” notation refers to the protein which is encoded by the lab DNA/RNA). The invention described herein used the antibody MCA 44-3A6 as a tool to clone the gene encoding Lab. In addition, an epitope (the necessary binding site for an antibody found on the antigen) for MCA 44-3A6 was identified on the Lab protein expressed by the clone to be PTGEPQ 2 (SEQ ID NO: 10). The epitope represents an important immunodominant sequence; that is, when injected into animals, the animals readily produce antibodies to this sequence. 2 Standard abbreviations for amino acids. An aspect of the invention is the use of lab DNA in the sense 3 expression mode for: 1) the marking of human tumors by nucleotide probes; 2) the detection of DNA and mRNA expression of lab in cells and tissues; 3) the transformation of cells into a glandular-like cell type; 4) the production of Lab antigen in vivo for immunization; 5) the ex vivo expression of Lab for immunization to produce antibodies; and 6) production of Lab in vitro. Use of an antisense molecule, e.g. by production of a mRNA or DNA strand in the reverse orientation to a sense molecule, to suppress the growth of labyrinthin-expressing (cancerous) cells is another aspect of the invention. 3 The normal transcription of a DNA sequence which proceeds from the 3′ to the 5′ end to produce a mRNA strand from the sense strand of DNA, the mRNA being complementary to the DNA. An aspect of the invention is a vector comprising a DNA molecule with a nucleotide sequence encoding at least an epitope of the Lab antigen, and suitable regulatory sequence to allow expression in a host cell. Another aspect of the invention is an amino acid sequence deduced from the protein coding region of the lab gene. Select regions of the sequence were found via immunological methods, to correspond and react to both naturally occurring (from cancer cells), chemically produced (synthetically produced peptides), and the expression of the cloned lab gene. Another aspect of the invention is the use of the entire deduced amino acid sequence of Lab, peptides derived from Lab, or chemically produced (synthetic) Lab peptides, or any combination of these molecules, for use in the preparation of vaccines to prevent human cancers and/or to treat humans with cancer. For purposes of the present invention, “humans with cancer” are those persons who have the Lab antigen detected on their cells. These preparations may also be used to prevent patients from ever having these tumors prior to their first occurrence. Monoclonal antibodies directed to the Lab protein, or antigen components or derivatives of Lab proteins, are useful for detection of Lab and for other purposes. Monoclonal antibodies which are made in species other than those which react with the Lab antigen can be modified by a number of molecular cloning such that they retain their binding with the Labyrinthin peptides, yet are not immunogenic in humans (Sastry, et al., 1989; Sambrook, et al., 1990). In brief, this is done by replacing the binding site sequence of a cloned human antibody gene, with the binding site sequence of the non-human monoclonal antibody of interest. These “humanized” MCAs are used as therapeutic and diagnostic reagents, in vivo, ex vivo, and in vitro. The use of the Lab protein or antigenic peptides derived therefrom in diagnostic assays for cancer is a way to monitor patients for the presence and amount of antibody that they have in their blood or other body fluids or tissue. This detection is not limited to cancers of a class or classes previously defined, but is useful for cancer cells that have the Lab marker antigen. The degree of seroconversion, as measured by techniques known to those of skill in the art [e.g. ELISA (Engrall and Perlmann, 1971)] may be used to monitor treatment effects. Treatment with antisense molecules to lab or antibodies to Lab is an approach to treat patients who have Lab in, or on, their cancer cells. INCORPORATION BY REFERENCE All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. BRIEF DESCRIPTION OF THE DRAWINGS The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which: FIG. 1 is the nucleic acid sequence (SEQ ID NO: 1) of the lab gene. FIG. 2 is the amino acid sequence (SEQ ID NO: 2) for Lab, deduced from the lab gene. FIG. 2 also discloses residues 25-52 of SEQ ID NO: 2 and SEQ ID NOS 3-5, respectively, in order of appearance. FIG. 3 is an illustration of the lab gene and how it is related to the HAAH enzyme. DETAILED DESCRIPTION OF THE INVENTION Molecular Biology of Labyrinthin: To demonstrate that the MCA 44-3A6 epitope is encoded by a protein sequence, high molecular weight DNA from the cell line A549 was isolated. This DNA was co-precipitated (via calcium) with a plasmid (pSVneo), and used to transfect a mouse cell line designated B78H1 cells (Albino, et al., 1985). This mouse cell line is negative for the expression of the epitope and was reported to have a high frequency of incorporation and expression of any human DNA sequences. If a given B78H1 cell was in a state to take up DNA, it would be expected to have taken up both human DNA and the plasmid DNA. The plasmid DNA makes the cell resistant to G418 (a normally toxic drug). Therefore, if a cell normally sensitive to G418 growth inhibitor grows in G418, it had to have taken up the plasmid, and may also have taken up one or more A549 DNA sequences. After G418 selection (a way of choosing only cells which have resistance to growth in G418 by the uptake/expression of the Neo gene on pSVneo plasmid, and therefore representing cells that were in a state to uptake other DNA at the same time), approximately 15 of 1×105 clones were detected using immunoselection with MCA 44-3A6. This finding is consistent with a conclusion that human A549 cells have DNA that encodes Lab and possesses the regulator sequences necessary for the expression of Lab. Comparison of HAAH and Labyrinthin: Because the DNA sequence of lab was determined as an aspect of the present invention, HAAH and lab could be compared. HAAH and the lab nucleotide sequences have some internal fragment similarities, but are different on either side of the fragment, and are related to different products. This conclusion is based in part by the—analysis and homology of the DNA sequences reported for these two genes. Specifically, the lab 5′ region has no homology with HAAH. The protein coding region of lab has about a 99.6% homology with an internal segment of the proposed protein coding region for HAAH. The 3′ region has no homology with the HAAH reported sequence. Virtually all of the other data comparing HAAH and labyrinthin are different, for example: 1) molecular weights of the proteins, 2) cellular localization, 3) chromosome localization, 4) histological presentation in normal tissues and tumors, 5) northern blot expression, 6) immunological findings. Although the protein coding region of lab is identical to an internal region of the sequence reported for HAAH, the 5′ untranslated region of HAAH is different; and part of the 5′ translated protein coding region of HAAH is missing from that found in the lab clone. From both HAAH and lab clones, the deduced protein would be expected to be very acidic in nature, and therefore would run anomolously in SDS gels. As predicted, the Lab protein migrates anomolously in SDS gels. What was cloned and disclosed in the present invention migrates identically to the native protein found in several cell lines. Convincing evidence that the correct gene fragment encoding the antigen detected by MCA 44-3A6 has been cloned (mRNA) is that when the recombinant protein is made, that recombinant protein should act (in this case—have an apparent molecular weight) the same as independent biologically derived source of that protein. Lab provided from clones has the characteristics of Lab from cells. The deduced amino acid sequence encoded by HAAH requires the use of an open reading frame which would produce a protein that is 85-90 kilodaltons, and does not take into account that there are several start codons and other shorter open reading frames. The deduced HAAH protein (biochemically) is glycosylated and the reported sequence has glycosylation sites (Korioth, et al., 1994; Lavaissiere, et al., 1996). To the contrary, Lab is not glycosylated, nor does it have predicted glycosylated sites. The deduced HAAH amino acid sequence contains a region shared by the Lab amino acid sequence which is predicted to be very hydrophobic. Lab requires strong detergents in order to be soluble; HAAH does not. The increased expression of HAAH (by enzyme activity measurements) in the same cell line (A549) which was used to clone and study lab extensively, suggests that both of these gene products may be important to the AC phenotype and that at least A549 cells make both functional HAAH and Lab. Successful transfections of the antisense to lab into A549 resulted in a marked decrease in expression of lab and in the growth rate of the cells. The expression of a sense lab construct in NIH-3T3 cells (normal mouse fibroblasts) resulted in a marked change in phenotype, a phenotype consistent with that of ACs. Therefore, lab expression is associated with conversion of normal cells to cancerous cells. Lab and HAAH have potential calcium binding domains in common. cDNA Library Construction and Cloning: A cDNA lambda gt11 phage library was constructed using mRNA which was isolated from actively growing A549 cells (Sambrook, et al., 1990). This oligo(dT)-primed cDNA was cloned into the Eco RI site using Eco RI linkers. The library has about 83% clear (containing an insert) plaques with a titer of 1.2×10 10 /ml representing a minimum of 1.46×10 6 independent plaques which, by Polymerase Chain Reaction, have insert sizes ranging from 0.6 to 5 kilobases. Since Lab is a 40 kilodalton integral protein, (a protein which is embedded in the plasma membrane,) the theoretical full length mRNA encoding this protein, including a potential leader sequence is estimated would be about 1.1 kilobases. This library was immunoscreened using the antibody MCA 44-3A6. Eight independently derived phase stocks (identical phage which are from the same plaque) were isolated. These have all been plaque purified by repeated cycles of immunoscreening/isolation. Upon Eco RI digestion of these eight isolates, inserts of about 2 kb were seen. The largest insert was isolated (2A1 A1) and the Eco RI fragment was cloned into the pGEM-3Z plasmid. Sequencing and Sequence Analysis: The DNA fragment designated 2ALA was found to have an insert of 2442 base pairs in length ( FIG. 1 ), containing a 5′ untranslated region, a ribosome binding site, and a start codon which would be expected to encode a 255 amino acid protein ( FIG. 2 ). The 3′ untranslated region is remarkable in that it contains only four instability sequences; ATTTA (Xu, et al. 1997). In addition there are sequences found in the very 3′ end of mRNA's which result in adenylation of the mRNA (Sambrook, et al., 1990). The lab sequence contains both a sub-optimal (ATTAAA) and optimal (AATAAA) poly-adenylation site. These are sequences found in the very 3′ end of mRNA's which result in adenylation of the mRNA. This finding provides molecular data which supports the cellular and biochemical data that has been outlined herein. (The HAAH clone has a poly A signal, but the whole 3′ region has not been sequenced.) A calcium binding site motif is noted in the Lab amino and sequence ( FIG. 2 ), however, it is out of the known required structural context to be a binding site. In this case, the calcium limiting sequence is there, but it is not in a protein sequence context that is known to make it work as a binding site! Homology was noted with lab and an EST clone (designated #05501) which represented only a portion of the 3′ untranslated region and independently confirmed this portion of the sequence. Some internal fragment homology is also noted with HAAH, but the 5′ untranslated and part of the 5′ translated region is different (58 amino acids), as well as a major portion of the 3′ coding region is missing in lab ( FIG. 3 ). Genomic DNA Cloning and Analysis: Using a PCR fragment representing the protein coding region of lab as a probe, a genomic lambda FIX II library made from the human pulmonary fibroblast cell line WI-38 was screened. Ten primary plaques were isolated out of approximately 1×10 6 screened plaques. Using seven of these as target DNA, Polymerase Chain Reaction conditions were established with primers for the protein coding region, producing a 765 base pair fragment, the expected protein coding region for lab. On Northern blots (a method used to qualitatively assess mRNA) lab only detects one band noted at 2.7 kilobases. The recombinant protein made from the lab clone, when tested on Western blots (a method used to qualitatively define proteins) using MCA 44-3A6, has the same relative mobility as the Lab protein when made by A549 cells. Lab and HAAH genes give different results in the proteins they encode. HAAH consistently gives two bands on Northern blot analysis (2.6 and 4.3 kilobases) suggesting that the 2.6 kilobase band is due to alternative splicing, i.e. the cell cuts and splices the mRNA. Also, if lab and HAAH are the same gene, HAAH should be detected in all tissues and cancer cell lines in which Lab is found. However, Lab is not seen on Northern blots of cell lines EMT6 or QU-DB, nor is there immunoreactivity in these cells; indicating that Lab mRNA is not made, and that Lab protein is not produced in these cells. Lab protein is rarely expressed in normal cells, where both the HAAH mRNA and HAAH protein have been reported to be expressed in almost every tissue studied. mRNA Analysis: Northern blot analysis of the DNA fragment from the A549 cell line using lab cDNA as a probe identified a single band of about 2.7 kilobases. This is expected based on the cDNA (2442 base pairs) and a poly-A tail of about 300 base pairs. Northern blot analysis of the mouse cell line, EMT6, and of the human large cell carcinoma cell line, QU-DB, confirm that no transcript for lab is produced by these cells. This is consistent with immunoassays which are negative for lab expression on these cells. Antisense and Sense cDNA Expression: The plasmid (pBK-CMV) (Sambrook, et al., 1990) may carry either the sense or antisense full length cDNA lab into A549 and NTH 3T3 cells. An antisense molecule can be, for example, a complementary sequence to a sense molecule that hybridizes with the sense molecule, preventing its expression. Using the MIT assay (Siddique, et al., 1992) to assess the growth rate of A549 cells expressing antisense to lab, a marked reduction in growth rate was noted. The antisense transfected A549 cells appear to have a greater degree of contact inhibition. A detectable amount of Lab is reduced in these antisense transfected cells. NIH-3T3 cells convert from a fibroblast-like cell type morphology (large, thin spindle shaped) to a large, adenocarcinoma appearing cells (very round, plump) when sense expression occurs. Chromosome Localization: The chromosome localization for lab, using full length cDNA as a probe via in situ hybridization (Sambrook, et al. 1990) is tentatively on chromosome 2q12-14, with possibly some reactivity to chromosomes 4 and 8. Using the same probe (the full length cDNA sequence of lab) and FACS sorted chromosomes (Lebo, et al. 1985) staining was also noted on chromosome 2, with weak staining on 4 and none on 8. The use of genomic clones will be of particular value in resolving these data because higher stringency hybridization conditions than that allowable for the cDNA, can be used, thereby reducing background signals. This is yet another proof that the correct gene was cloned and that the results are not due to a method artifact. There may be mutations in the genomic DNA of tumors and for the present invention, DNA was cloned from tumor cells (A549). Therefore, a mutated gene could have been cloned. However, that is not the case because the genomic DNA from a normal cell (DNA) produced the same sequence as what cloned as described herein. Therefore, a normal gene was cloned from A549 cells. The weak signals on chromosomes 4 and 8 are consistent with a pseudogene or a related gene. For example, HAAH has been reported to be on chromosome 8q12 by in situ hybridization, so this result on chromosome 8 could reflect the HAAH and lab sequence homology. Protein Molecular Characterization of Labyrinthin: Previous work using Western blot analysis (a qualitative assay to assess antigens) has shown that the Lab antigen is a 40 kilodalton (by relative mobility) protein detectable in A549 cells (Radosevich, et al., 1985). The epitope does not appear to be modulated or blocked by lectins, and is selectively expressed on the cell surface, primarily localized to the plasma membrane. (Radosevich, et al., 1985, 1991). Lab is sensitive to proteases, but not lipid or carbohydrate altering reactions (Radosevich, et al., 1985). The biochemical properties of Lab are consistent with Lab being an integral membrane protein. Having a deduced amino acid sequence from the lab gene of the present invention, allows further characterization of the Lab protein. Extensive computer analysis of Lab has identified a eukaryotic leader-like sequence and theoretical cleavage site, 3 myristylation sequence sites, a weak membrane anchoring domain (MAD I), and a strong membrane anchoring domain (MAD II) ( FIG. 2 ). [(In the HAAH sequence, there are 58 (theoretical) amino acids followed by a sequence homology in the Lab protein coding sequence, and an additional 445 amino acid 3′ to the lab sequence.)] When Lab is expressed as a fusion protein in a bacterial GST fusion expression system (pGEMEX-2T) (Amereham Pharmacia Biotech, Inc., Piscataway, N.J., 08854, USA), and subjected to Western blot analysis using the antibody MCA 44-3A6, the resulting blots demonstrate that the expressed cleaved fusion protein has the same relative mobility as the protein detected in A549 cells. The deduced molecular weight for Lab is 28.8 kilodaltons and on Western blots it has a relative mobility identical to the form expressed by A549 cells (apparent relative mobility=40 kilodaltons). The 55 glutamic and 27 aspartic acid residues (82 residues combined) are almost uniformly distributed throughout the protein (255 amino acids total; 228 no leader sequence), except for the leader sequence and the strongest membrane anchoring domain (MAD II). These data suggest that Lab migrates anomalously in SDS gels. Cell lines other than A549 (e.g. adenocarcinomas DU-145, ATCC #HTB-81; ZR-75-1, ATCC #CRL-1504, and so forth) have an antigen detected with the same molecular weight antigen as Lab. Neither a 85-90 kilodalton molecular weight species, nor a 52 and 56 kilodalton molecular weight species is noted when probing Western blots for Lab. Epitope Mapping Using the Antibody MCA 44-3A6 and Vaccine Feasibility of Lab: Using Polymerase Chain Reaction and the GST fusion protein system, subclones of the protein coding region were made, and epitopes mapped the binding of MCA 44-3A6 to six amino acids (PTGEPQ) (SEQ ID NO: 10) representing amino acids #117-122 of Lab (“P” peptide). In order to determine this epitope, the entire coding region was divided into regions, Polymerase Chain Reaction primers were designed to amplify each region, and the subsequent expression of Polymerase Chain Reaction products were cloned and tested by Western blot analysis using the antibody MCA 44-3A6. The DNA fragment representing the positive Western blot result was then further subdivided. Polymerase Chain Reaction products were generated and cloned, expressed, and tested via Western blot. Constructs were made in this way both from the 5′ end and the 3′ end and the intervals of the number of amino acids were reduced upon each round. This resulted in the last round representing a one amino acid difference from the previous round (in both directions), such that one could deduce the exact binding site of the MCA 44-3A6. This demonstrates that at least these six amino acids are exposed to the external cell surface. To further prove the point, the DNA encoding only these six amino acids have been cloned and the fusion protein is positive by Western blot analysis. Synthetically prepared “P” peptide can be specifically detected by MCA 44-3A6, and the synthetic peptide was immunogenic in 5 of 5 mice tested. Computer analysis/modelling also predicted that this epitope would be very immunogenic using computer assisted analysis (GCG programs) (Genetics Computer Group, Madison, Wis. 53703). Vaccine Preparation: A vaccine is a preparation of antigen(s), which when given to a host, results in the host producing antibodies against the antigen(s). The host response results in the host being immune to the disease to which the vaccine was directed. Vaccine treatment therefore, prevents the clinical presentation of a disease, without the host being exposed to the disease causing agents. Lab has all the characteristics of a preferred cancer vaccine. The lab gene is frequently expressed by tumors which look like adenocarcinomas, is expressed on the outside of the cells, is expressed by all of the cells within a given cancer, is expressed at all times by these cancer cells, and is infrequently expressed by normal cells. Lab protein (peptides) can be produced by any number of methods using molecular cloning techniques, and can be produced in large quantities, thus making it a practical antigen to use as a vaccine. After the Lab protein has been purified so that it is suitable for injection into humans, it is administered to individuals intradermally, subcutaneously, or by other routes, so as to challenge the immune system to produce antibodies against this protein (peptides). The use of molecular modeling and computer assisted analysis GCG programs (Genetics Crystal Group, Madison, Wis. 53703) allows the identification of small portions of a molecule, slightly larger than an epitope (six to seven amino acids for proteins), which are expected to be on the surface of a protein molecule. In addition, the degree of hydrophobicity or hydrophilicity of a given sequence, and how immunogenic the sequence would be in animals, can be determined (Genetics Crystal Group, Madison, Wis. 53703). After defining which sequences meet these criteria, the peptides are synthetically made, or produced by a number of standard methods. One or more of these peptides can then be formulated to be used as a vaccine, and administered to the host as outlined above, as a vaccine. A vaccine comprising a molecule having an amino acid sequence selected from the group of sequences encoded by the cDNA of FIG. 1 , sequences of FIG. 2 , encoded by the cDNA, the peptides APPEDNPVED (SEQ ID NO: 6), EEQQEVPPDT (SEQ ID NO: 7), DGPTGEPQQE (SEQ ID NO: 8) and EQENPDSSEPV (SEQ ID NO: 9), and any fragments, or combinations thereof. A given vaccine may be administered once to a host, or may be administered many times. In order for some patients to recognize a given vaccine, an adjuvant may also need to be administered with the peptides. Adjuvants are nonspecific immune stimulators which heighten the immune readiness and aid in the conversion of the host from not having detectable serum antibodies to having very high titer serum antibodies. It is this high level (titer) of antibodies, which effectively protects the host from the diseases or conditions to which the antibodies are directed. Functional Studies: Studies directed at understanding the cellular function(s) of Lab are extensions of cell localization/characterization studies (Siddique, et al. 1992). Changes in levels of Lab in cations (Ca++, Mg++, Cu++, and Fe++) were undertaken. Lab expression in A549 cells was only modulated by Ca++. Using the highly specific fluorescent Fura-2/AM Ca++ method of measuring cytosolic Ca++, (Molecular Probes Inc., Eugene, Oreg. 97402) it was demonstrated that: 1) the internal Ca++ concentration is higher in A549 cells than in QU-DB cells, and 2) that the A549 cell line responds to various external Ca++ levels (Siddique, et al., 1992). Since pH can modulate intracellular free Ca++ levels, external pH manipulations should result in changes in the expression levels of Lab. Extracellular pH changes (in the presence of normal Ca++ concentrations) result in 1) a parallel change in intracellular pH as measured by SNARF-1 AM/FACS, (Molecular Probes Inc., Eugene, Oreg. 97402) 2) transcript levels increase for Lab (when compared to GAPDH expression via Northern blot), and that 3) Lab protein also increases (using Western/Slot blot analysis). The intracellular changes in pH (due to external changes) for A549 cells are identical to those reported for normal cells. The increased expression of lab is also not due to cell death (as measured by MTT assays) (Siddique, et al., 1992). In addition, incubation of recombinant Lab at various pH solutions does not alter immunoreactivity. Preliminary data suggests that when these experiments are conducted on A549 cells grown in reduced Ca++, the induced expression of lab is blunted. Methods of Diagnosing Cancer Cells in a Sample of Cells: Biological samples from a subject are used to determine whether cancer cells are present in the subject. Examples of suitable samples include blood and biopsy material. One method of diagnosis is to expose DNA from cells in the sample to a labeled probe that is capable of hybridizing to the lab gene, or a fragment thereof, under stringent conditions, e.g. 6× ssc; 0.05× blotto; 50% formamide; 42° C. (Sambrook, et al., 1990). Of course, the hybridizing conditions are altered to achieve optimum sensitivity and specificity depending on the nature of the biological sample, type of cancer, method of probe preparation, and method of tissue preparation. After contacting the sample with the probe, the next step is determining whether the probe has hybridized with nucleotide sequences of the DNA from the sample, from which the presence of the lab gene is inferred, said presence being diagnostic of cancer. Another diagnostic method is to obtain monoclonal antibodies preferably labeled, either antibodies already existing, or new ones directed to the antigenic peptides that are aspects of the present invention, and contact a sample with these to detect the Lab antigen. These monoclonal antibodies are useful in the development of very specific assays for the detection of Lab antigen, and allow the tests to be carried out in many different formats; resulting in a broader application in science and medicine. The current invention is useful in that it describes a new gene which is expressed on the surface of tumors, which was not previously reported. This gene is not tissue specific, and therefore will allow the detection of tumors regardless of the organ in which they arise. Likewise, the use of this gene to produce a vaccine for these tumors, will have a very broad application. Diagnostic tests will also have this broad tissue use, making the detection of Lab//ab a “pan-marker” for cancer, in particular for what have been designated previously, adenocarcinomas. While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby. DOCUMENTS CITED Albino, A P, Graf, L H, Kontor, R R S, et al. DNA-mediated transfer of human melanoma cell surface glycoprotein gp130: Identification of transfectants by erythrocyte rosetting. Mol. Cell. Biol. 5:692-697, 1985. Banner B F, Gould V E, Radosevich J A, et al. Application of monoclonal antibody 44-3A6 in the cytodiagnosis and classification of pulmonary carcinomas. Diag Cytopathol. 1:300-307, 1985. Brown, D T and Moore, M. Monoclonal antibodies against two human lung carcinoma cell link. Br. J. Can. 46:794-801, 1980. Combs S G, Hidvegi D F, Ma Y, et al. Pleomorphic Carcinoma of the Pancreas: A rare case report of combined histological features of pleomorphic adenocarcinoma and giant cell tumor of the pancreas. Diag. Cytopathol. 4:316-322, 1988a. Combs S G, Radosevich J A, Ma Y, et al. Expression of the Antigenic Determinant Recognized by the Monoclonal Antibody 44-3A6 on Select Human Adenocarcinomas and Normal Human Tissues. Tumor Biol. 9:116-122, 1988b. Combs S G, Radosevich J A, and S T Rosen. Cytological expression of the adenocarcinoma antigen marker in human body fluids. Tumor Biol. 9:116-122, 1988c. Duda R B, August C Z, Radosevich J A and S T Rosen. Monoclonal Antibody 44-3A6 as a Marker For Differentiation of Breast Cancer. Tumor Biol. 12:254-260, 1992. Engvall, E. and Perlmann, P. Enzyme linked immunosorbent assay (ELISA): Quantitative assay of IgG. Immunochemistry. 8:87-874, 1971. Gronke R S, VanDusen W J, Garsky V M, Jacobs J W, Sardana M K, Stern A M, and P A Friedman. Aspartyl beta hydroxylase: In vitro hydroxylation of a synthetic peptide based on the structure of the first growth factor-like domain of human factor IX. PNAS. 86:3609-3613, 1989. Gronke R S, Welsch D J, VanDusen W J, Garsky V M, Sardana M K, Stem A M, and P A Friedman. Partial purification and characterization of bovine liver aspartyl beta hydroxylase. J. Biol. Chem. 265:8558-8565, 1990. Jia S, VanDusen W J, Diehl R E, Kohl N E, Dixon R A F, Elliston K O, Stern A M, and P A Friedman. cDNA cloning and expression of bovine aspartyl(asparageinyl) beta-hydroxylase. J. Biol. Chem. 267:14322-14327, 1992. Jia S, McGinns K, VanDusen W J, Burke C J, Kuo A, Griffin P R, Sardana M K, Elliston K O, Stern A M, and P A Friedman. A fully active catalytic domain of bovine aspartyl (asparaginyl) beta-hydroxylase expressed in Escherichia coli : Characterization and evidence for the identification of an active-site region in vertebrate alpha-ketoglutarate-dependent dioxygenases. PNAS 91:7227-7231, 1994. Korioth F, Gieffers C, and J. Frey. Cloning and characterization of the human gene encoding aspartyl beta-hydroxylase. Gene 150:395-399, 1994. Landis, S. H., Murray, T., Bolden S., and P. A. Wingo. Cancer Statistics, 1998., CA 44:6-9. Lavaissiere L, Jia S, Nishiyama M, de la Monte S, Stren A M, Wands J R, and P A Friedman. Overexpression of human aspartyl (asparaginyl) beta-hydroxylase in hepatocellular carcinoma and cholangiocarcinoma. J. Clin. Invest. 98:1313-1323, 1996. Lebo, R V, Tolan, D R, Bruce, B D, Cheng, M C, and Kan, Y W. Spot blot analysis of sorted chromosomes assigns a fructose intolerance gene locus to chromosome 9. Cytometry. 6:476-483, 1985. Lee I, Radosevich, J A, Rosen, S T, et al. Immunohistochemistry of lung carcinomas using monoclonal antibody 44-3A6. Can. Res. 45:5813-5817, 1985. Lee I, Radosevich J A, Chejfec G, et al. Malignant Mesotheliomas: Improved Differential Diagnosis From Lung Adenocarcinomas Using Monoclonal Antibodies 44-3A6 and 624A12. Amer. J. Path. 123:497-507, 1986. Livingston, P O, Wong, G Y C, Adluri, S, Tao, Y, Padevan, M, Parente, R, Hanlon, C, Calves, M J, Helling, F, Ritter, G, Oettgen, H F, and Old, L J. Improved survival in AJCC stage III melanoma patients with GM2 antibodies: A randomized trial of adjuvant vaccination with GM2 ganglioside. J. Clin. Oncol., 12:1036-1044, 1994. Piehl M R, Gould V E, Radosevich J A, et al. Immunohistochemical Identification of Exocrine and Neuroendocrine Subsets of Large Cell Lung Carcinomas. Path. Res. and Prac. 183:675-682, 1988. Radosevich J A, Ma Y, Lee I, et al. Monoclonal antibody 44-3A6 as a probe for a novel antigen found human lung carcinomas with glandular differentiation. Can. Res 45:5805-5812, 1985. Radosevich J A, Lee I, Gould V E, and ST Rosen. Monoclonal antibody assays for lung cancer. In: In vitro diagnosis of human tumors using monoclonal antibodies. Kupchik H Z and N Rose (Eds.) Marcel Dekker p 101-119, 1988. Radosevich J A, Combs S G, and S T Rosen. Immunohistochemical analysis of lung cancer differentiation markers. In: Lung Cancer Differentiation. Lung Biology in Health and disease. L'Enfant C, Bernal S, and Baylin S. (Eds.). Marcel Dekker, 1990a. Radosevich J A, Noguchi M, Rosen S T, Y. Shimosato. Immunocytochemical analysis of human adenocarcinomas and bronchioloalveolar carcinomas of the lung using the monoclonal antibody 44-3A6. Tumor Biology. 11:181-188, 1990b. Radosevich J A, Combs S G, and S T Rosen. Expression of MCA 44-3A6 in human fetal development. Tumor Biology 12:321-329, 1991. Radosevich J A, Siddique F S, Rosen S T, and W J Kabat. Cell Cycle and EM Evaluation of the Adenocarcinoma Antigen Recognized by the Monoclonal Antibody 44-3A6. Br. J. Can. 63:86-87, 1991. Rosen, S T, Mulshine, J L, Cuttitta, F, and Abrams, P G. Biology of Lung Cancer. Marcel Dekker, Inc. New York, N.Y., Vol. 37, 1988. Sambrook J, Fritsch E F, and T Maniatis. Molecular cloning: a laboratory manual. 2nd Ed. Cold Spring Harbor Lab. Press., 1990. Sastry, L., Alting-Mees, M, Huse, W D, Short, J M, Hay, B N, Janda, K D, Benkovis, S J, and Lerner. Cloning of the immunological repertoire in Escherichia coli for generation of monoclonal catalytic antibodies: Construction of a heavy chain variable region-specific cDNA library. PNAS. 86:5728-5732, 1989. Siddique F S, Iqbal Z, and J A Radosevich. Changes in the expression of the tumor-associated Antigen recognized by monoclonal antibody 44-3A6 in A549 cells due to calcium. Tumor Biol. 13:142-151, 1992. Sinkule J, Rosen S T, and J A Radosevich. MCA 44-3A6 Douxorubicin (Adriamycin) Immunoconjugates: Comparative In Vitro Anti-Tumor Efficacy of Different Conjugation Methods. Tumor Biol. 12:198-206, 1991. Spagnolo D V, Witaker D, Carrello S, et al. The use of monoclonal antibody 44-3A6 in cell blocks in the diagnosis of lung carcinoma, carcinomas metastatic to lung and pleura, and pleural malignant mesothelioma. Am. J. Clin. Path. 95:322-329, 1991 Stahel, R A (Chairman). Third International IASLC Workshop on Lung Tumor and Differentiation Antigens. Inter. J. Cancer Suppl 8:6-26, 1994. 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A cDNA molecule that encodes a protein designated Labyrinthin (Lab) isolated and its nucleotide sequence is determined. The protein, or peptides derived from the protein, are markers useful to define novel classes of cancers. Diagnostic assays for these cancers use antibodies to Lab or nucleotide probes that hybridize with the lab gene or a fragment therefrom. Vaccines useful either to prevent recurrence of cancers in subjects who test positive for Lab (or lab), or to prevent initial occurrence of cancer, use proteins or peptides derived from Lab. Expression of Lab via immunogenic assays is used to monitor effects of cancer treatments. Antisense molecules against lab are used in treatments. Sense molecules of lab are used to restore lost lab function in diseased normal cells, for example, gland cells.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to a method for determining a partial-load condition of a system comprising several components, a computer program product, and the use of such an overall system partial-load condition. [0003] 2. Description of the Related Art [0004] Conventional systems, i.e., production and manufacturing systems, are at present usually operated at full load, or are completely switched off. In the event of the system being only partially utilized, incurred, for example, due to the circumstances of a particular order, it would be advantageous, not least with regard to energy consumption of the system, to operate the system in a partial-load operational mode. [0005] In addition to the energy advantage referred to, other circumstances, i.e., maintenance intervals and service life of individual components, favor the operation of a system in a partial-load condition, instead of operating the system for a specific time under full load and thereafter having the system in a state of rest. [0006] If it is intended that a complete system is to be operated in a specific partial-load condition then the individual components of this system must naturally be operated in an individual partial-load condition. The term “components” is to be understood to mean, for example, processing devices or robots of a manufacturing line, and also facilities such as conveyor belts and motors, which are frequently provided with an at least minimal electronic control and a more or less significant communications interface for the exchange of process and operational data. [0007] With the operation of individual components of the system in a partial-load condition, it is to be borne in mind that, on the one hand, certain components do not allow for every partial-load condition at will, and that, moreover, possible or permissible partial-load conditions of individual components do not have the same effect on the system. For example, a motor can be operated at 25% of a full capacity provided for, while the machine downstream thereof may only be capable of operation at 50%. [0008] Another problem lies in the fact that the operation of all the components of the system in a specific partial-load condition, such as 50% of the full capacity provided for, has different effects on different components. For example, a partial-load condition of 50% on a first component may have a different effect on its throughput than on a second component. The relationship between partial-load conditions of a component and operating parameters such as the throughput as referred to heretofore, is at present not defined either for individual components or for the system as a whole. Even if a definition were to be available for individual components, a system planner would still be confronted by the problem of realizing an implementation of at least one partial-load condition in a complete system which, due to the differing forms of behavior of individual components, represents an extremely complex problem. SUMMARY OF THE INVENTION [0009] It is therefore an object of the invention to provide a method for determining a partial-load condition for a system comprising several components. [0010] This and other objects are achieved in accordance with the invention by a method, and computer program, by the use thereof in a process control system and by use in a component in which the method in accordance with the invention determines a partial-load condition of a system comprising several components by evaluating an energy model of at least one component of the system, by which a set of operating parameters of this component is allocated to at least one partial-load condition of this component, by evaluating specification parameters, which comprise specifications for a throughput of the system which is to be set, by determining a set of partial-load conditions of the system based on the at least one energy model, taking into account the specification parameters, and by simulating the set of partial-load conditions based on a parameterizable simulation model of the system. [0011] The sequence of the first two method steps is essentially optional, such that the evaluation of the energy model and the evaluation of the specification parameters can also be effected in a sequence other than the disclosed sequence. [0012] The invention is based on at least one energy model, which ideally although not necessarily is provided for almost every component of a system. [0013] By application of the method in accordance with the invention, a system planner is placed in a position, by specifying specification parameters, such as a minimum throughput of the system or a maximum energy consumption, to obtain a set of partial-load conditions, i.e., a partial-load condition for each of the components involved in the determination. In this way, an individual partial-load condition can be adjusted for each component, where all partial-load conditions fulfill the provisions of the specification parameters. [0014] Advantageously, the operating parameters of the energy model obtain a time duration that indicates the time required by a component for a change into a particular partial-load condition of the component or for a change from one particular partial-load condition into another. [0015] In an advantageous embodiment of the invention, the operating parameters of the energy model contain an energy consumption of a particular partial-load condition of the component. Such a measure allows for an optimization of the system as a whole in respect of a partial-load condition in which the components operate on the condition of a desired throughput in the most energy-efficient manner possible. [0016] In accordance with a further advantageous embodiment of the invention, the operating parameters also contain an energy consumption which is required for a change from, or for a change to, a particular partial-load condition of the component. In order to adjust a favorable energy consumption for the system, in this case dynamic aspects, which come into effect at a partial-load condition change of the system, are therefore also taken into account. [0017] In a further advantageous embodiment of the invention, the operating parameters of the energy model contain data for the operation of the component in a particular partial-load condition. The data referred to, relating to the operation, are to be understood in this case to be primarily a component-related throughput, including an indication that, with a 50% partial-load operation, for example, of a motor, a 40% throughput in comparison with the full-load operation is to be anticipated. This factor takes account of the circumstance that a partial-load operation does not necessarily run in a linear manner with the throughput of the component related to it. [0018] In another advantageous embodiment of the invention, the operating parameters contain values that contain an effect of a partial-load condition and of a change between particular partial-load conditions on the service life and on a required maintenance interval of the component. The presently contemplated embodiment guarantees that account is taken of the effects a change of partial-load conditions can have on an increase in maintenance intervals or on the service life of an individual component or of the system as a whole, respectively, which must be taken into account. [0019] In a further advantageous embodiment of the method in accordance with the invention, the specification parameters comprise, as well as a throughput of the system which is to be set, specifications for an energy consumption of the system that is to be set. The energy consumption of a system, which in the past tended to play a subordinate role, is increasingly incurring a considerable amount of interest in the operational management planning of a system. [0020] In an advantageous further embodiment of the method in accordance with the invention, a decentralized optimization method is provided for the determination of the set of partial-load conditions of the system. This optimization method is put into effect in particular with the use of market-based optimization methods. [0021] In a further advantageous embodiment of the invention, the set of partial-load conditions obtained by simulation is revised by an iterative optimization method. This is performed by a repeated determination of a set of partial-load conditions with revised specification parameters and/or with at least one revised energy model. With such revision of a determination of partial-load conditions, consideration may also be given to replacing an existing component of a system by an alternative component, which is provided with an energy component that differs from the replaced component. The method in accordance with the presently contemplated embodiment can, if required, be run through repeatedly, in order to derive an optimized set of partial-load conditions of the system. [0022] The determination in accordance with disclosed embodiments of the invention of the set of partial-load conditions of the system can be performed alternatively centralized or decentralized. In a central arrangement, the individual energy models of the components are transferred to a central system, for example, to a process control system (manufacturing execution system), in order to then perform a centralized determination. The centralized system can make use, for example, of data from an engineering tool. [0023] In the case of a decentralized arrangement, the evaluation is divided over several components. This decentralized embodiment is advantageous in particular if every component has its own data processing possibility and communication unit. [0024] Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. BRIEF DESCRIPTION OF THE DRAWINGS [0025] An exemplary embodiment with further advantages and embodiments of the invention is explained in greater detail hereinafter on the basis of the drawings, in which: [0026] FIG. 1 is structure image for the schematic representation of an energy model of a component; [0027] FIG. 2 is structure image for the schematic representation of a determination of a set of partial-load conditions; and [0028] FIG. 3 is flow diagram for the schematic representation of a further optimization of a set of partial-load conditions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0029] Shown in FIG. 1 is a schematic representation of an energy model of a component. By making use of the component-based energy model, an energy management on the component level is realized by the provision of operating conditions, in the drawing to the right of the broken line, and by the provision of partial-load conditions, in the drawing to the left of the broken line. [0030] Represented in the right half of the energy model is a first operating condition IDL or “Idle” of the component. Represented in a circle which is arranged to the right of the first operating condition IDL, is a second operating condition STB or “Standby” of the component. Finally, a third operating condition HIB or “Hibernate” of the component is represented. [0031] Each operating condition, HIB, IDL, STB, in the energy model is provided with a parameter quantity (not shown). Within this parameter quantity, for example, time periods can be defined, which indicate how long a particular operating condition can be maintained as a minimum or maximum, and a time duration which is necessary for a change from a first operational condition to a second operational condition. [0032] The operational conditions HIB, IDL, STB represented in the right half model different conditions of rest of a component, which are provided, for example, from the Standard PROFlenergy for energy management of a component. [0033] In contrast, definition of partial-load conditions, represented in the drawing to the left of the broken line, is not provided for in the present solutions. In other words, an indication is at present not accessible, as to whether a component, let alone a system, can change into a partial-load condition. Accordingly, at present there is also no possibility of determining in an automated manner different partial-load conditions as a function of the components used, and as a function of peripheral conditions, such as efficiency or throughput. [0034] In accordance with the invention, the energy model of a component represented in FIG. 1 is extended by the partial-load conditions 33 , 80 , 100 . [0035] A first partial-load condition 33 contains, in a related parameter quantity, in addition to the parameters referred to above, also an item of information as to which operational condition is realized in the component in this first partial-load condition 33 , which corresponds to a 33% utilization in proportion to a full load of the component. [0036] The operating parameters that represent the operating behavior comprise in particular values, such as a throughput of the component in the first partial-load operation 33 , as well as an energy consumption in this partial-load condition 33 and an energy consumption required for a change of condition. [0037] For example, the data can be deposited for a drive unit that in the first partial-load condition 33 , which corresponds to a 33% utilization of the drive, the reference speed of the drive is 3,000 revolutions per second. It can also be deposited in the operating parameters that the drive accelerates and brakes at 500 s −2 . [0038] In advantageous embodiments, data can be deposited that define effects on maintenance intervals, wear, and service life of the corresponding component. These details further indicate that a frequent change between partial-load conditions can, from case to case, have negative effects on maintenance intervals or the service life of the component. A combination of all the operating parameters referred to is cited in the following energy model. [0039] Represented in FIG. 1 is a partial-load condition 80 , which corresponds to an 80% utilization of the component, as well as a third partial-load condition 100 , which corresponds to a full load of the component, i.e. 100%. [0040] FIG. 2 shows a structure image for the schematic representation of a determination of partial-load conditions of a system utilizing the method in accordance with the invention. Represented by way of example are three components C 1 , C 2 , C 3 of the system, where an individual energy model EM 1 , EM 2 , EM 3 is allocated to each individual component C 1 , C 2 , C 3 . The term “allocation” is to be understood to mean, on the one hand, a decentralized allocation, with which the energy models EM 1 , EM 2 , EM 3 are retained, for example, in a memory area pertaining to the component. In the case of a centralized allocation, not represented, the energy models EM 1 , EM 2 , EM 3 are retained centrally, for example, in a process databank. [0041] The energy models EM 1 , EM 2 , EM 3 , or, more precisely, the operating parameters and partial-load condition parameters retained in the energy models EM 1 , EM 2 , EM 3 are evaluated in a first step 1 a . The energy models EM 1 , EM 2 , EM 3 are preferably structured in a semantic description language. [0042] In addition, external specifications XSP are evaluated in a second step 1 b . As an external specification XSP, for example, a throughput is to be realized in the amount of 50% of the full-load operation of the system at minimum energy consumption. Maintenance and wear values can be defined as external specifications XSP. [0043] The evaluation occurs, for example, in an optimization component OPT, performed by a control unit CTR. The embodiment referred to, making use of a central control unit CTR, can, if required, also be replaced by a decentralized evaluation (not shown) in which the individual components C 1 , C 2 , C 3 perform the evaluation in a collaborative manner. [0044] Based on the energy models EM 1 , EM 2 , EM 3 and the external specifications XSP, a provisional set of partial-load conditions of the system is now determined in the optimization component OPT. In this optimization step, the optimization component OPT determines, for example, with the use of a decentralized optimization method, and in particular based on a market-based transaction, a partial-load condition of each component C 1 , C 2 , C 3 . [0045] In a second method step 2 , the provisional set of partial-load conditions of the system is conducted to a simulation component SIM, in which a simulation of the provisional set of partial-load conditions is performed based on a parameterizable simulation model of the system. This step serves to provide a verification of the set of partial-load conditions determined for the system based on real circumstances of the system. The simulation model of the system models the superordinated process of the system. The data exchange required for the simulation is taken over by the control component CTR. While the optimization concept OPT calculates all the permitted partial-load conditions based on the energy models EM 1 , EM 2 , EM 3 , the incorporation of the simulation component SIM restricts the partial-load conditions to the circumstances of the system, where account can also be taken of an initial or starting condition of the system. [0046] This method step 2 is performed several times if required, by the two arrows represented in the drawing, where the result of the simulation, revised if required, is returned to the optimization component OPT, and the result of the stimulation undergoes a new optimization. [0047] In this situation, the simulation result is evaluated again in the optimization component OPT, and, if appropriate, the optimization is restarted, in order to calculate a revised set of provisional partial-load conditions. [0048] After at least one optimization and simulation step has been performed in this manner, if necessary in an iterative process, then, as the result, a set of partial-load conditions PLS of the system is provided in the method step 3 . [0049] The set of partial-load conditions contains the partial-load conditions that are to be set of at least one component C 1 , C 2 , C 3 of the system, based on the partial-load condition of the system that is to be set by way of the external specifications XSP. For example, with a halved throughput of the system, as an external specification a partial-load condition of the conveyor belts can be derived of 40%, a partial-load condition of robots of 60%, a partial-load condition of the production control system of 90%, etc. [0050] The set of partial-load conditions PLS determined can be optionally checked by a system operator or planner, and again conducted to an optimization component OPT. Should the number of partial-load conditions or their values not be implementable, then, as represented in FIG. 3 , either the external specifications XSP, corresponding to step 5 , or components of the system, can be modified or exchanged, corresponding to step 4 . With a modification or exchange of a component C 1 , the energy model EM 1 allocated to the component C 1 also changes. Accordingly, a CMM also changes, in FIG. 3 as a total quantity of the individual energy models EM 1 , EM 2 , EM 3 . [0051] In a first branching A 1 “Solution quantity empty?” of the sequence diagram depicted in FIG. 3 , a check is first performed in a step 3 to determine whether, based on the external specifications XSP, which also include an arrangement of system equipment, a system layout, and an actuation of the system, and based on the total quantity CMM of the individual energy models EM 1 , EM 2 , EM 3 , a set of partial-load conditions PLS can in fact be determined at all by the optimization component OPT. [0052] If the solution quantity is not empty, corresponding to the “No” branch, identified by N, of the first branching A 1 , then, in a second branching A 2 , “Solution acceptable?”, a check is performed by the system operator or planner. In the opposite case, with an empty solution quantity, an adjustment according to step 5 is required, with a change of the external specifications, or, according to step 4 , with the adjustment of the total quantity CMM of the individual energy models EM 1 , EM 2 , EM 3 . In step 4 , no possible partial-load condition could be derived. As a consequence, either the external specifications or even the machine model must be changed, i.e., other machines must be used. [0053] In a similar way, in the event of a negative result, corresponding to the “No” branch identified by N, an adjustment to the second branching A 2 is performed, “Solution acceptable?”, in accordance with step 5 , with a change to the external specifications. [0054] In step 5 , partial-load conditions could be found but, to the knowledge of the system constructor, these are not acceptable. In this case, likewise, the external specifications (e.g., other throughput) can be adjusted. In this way, in an iterative manner, the best configuration can be found in the form of an optimum set of partial-load conditions, in accordance with method step E, “End”. [0055] While there have shown, described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the methods described and the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

A method for evaluating component-related energy models and external specification parameters, in order, based on these, to produce a determination of a set of partial-load conditions, which are simulated based on a parameterizable simulation model of the system. A system planner is put in a position, with the specification of specification parameters, for example, a minimum throughput of the system or a maximum energy consumption, in which he can obtain a set of partial-load conditions, i.e., a partial-load condition for each of the components involved in the determination. In this way, an individual partial-load condition can be set for each component, where all the partial-load conditions fulfill the provisions of the specification parameters.