Now, writing in Nature Materials, Daniel Müller and colleagues 6 report that integrin mechanosensing during adhesion is fast and involves the biphasic reinforcement of cell–ECM linkage. While much is known about the force sensing process, a comprehensive understanding of the early processes that regulate adhesion and mechanical signalling at the cell surface - namely, how quickly cells sense and respond to force via integrins - is still not available. Since then several studies have identified intracellular proteins such as talin 4 and vinculin 5 that facilitate force sensing and response. In the early 1990s it was shown that integrins also function as a mechanosensor that mediates force transmission to the actin cytoskeleton 3, an intracellular polymer network that determines cellular stiffness. These proteins bind to the ECM protein fibronectin 2 and are the main contributors for cellular adhesion. Cellular adhesion to the ECM is mediated by transmembrane adhesion molecules such as integrins 1. There will be a total of about 700,000 channels, which translates into about 5580 SVX-II chips, 66 to 100 Port Cards, 66 to 100 SARs, and four to eight SARCs.Most cells in the human body attach to the extracellular matrix (ECM), a polymer network connecting tissues, in order to survive and function properly. The Port Card receives the control codes and manipulates the SVX-II chips in the proper way to effect proper data taking. It is through these control codes that data taking operations such as data-acquisition, digitization, readout, and various resets can be carried out. The SARC resides in the same VME crate as the SARs, and transforms signals from the Trigger System into control codes distributed to the various Port Cards via optical fibers operating at 53 Mb/s. Control and sequencing of the whole operation starts with the Silicon Acquisition/Readout Controller (SARC) working in tandem with the D0 Clock System.
The FIFOs place their data onto the VME backplane to a VME Buffer Driver (VBD) which stores the event data in buffers for eventual readout over a thirty-two signal ribbon cable to the Level Two Computers and subsequent tape storage. Here, the data is transformed back to parallel electrical signals that are stored in one of several banks of FIFO memories. The Port Card houses a commercial chipset that serializes the data in real time and converts the signal into laser light impulses that are then transmitted through a multi-mode optical fiber about 150 feet to a Silicon Acquisition & Readout board (SAR). A cable then routes this bus approximately thirty feet more » out from the detector to the Port Card. The 128-channel chips are mounted on a High-Density Interconnect (HDI) that consists of a small flex circuit that routes control signals and eight data bits for each of three to ten chips onto a common data bus. This system consists of the following parts, starting at the detector: Silicon strip detectors are mounted in a spaceframe and wire-bonded to custom bare-die integrated circuits (SVX-II chips) that digitize the charge collected by the strips.
The Port Card will be one link in the data acquisition system for the D0 Silicon Vertex Detector.
With certain configuration, Serial Highway throughput approaching three megabytes per second can be achieved. Benchmark comparisons indicate the extremely high data throughput that has been obtained.
This paper describes these new products, details their performance, and recommends trade-offs for their application.
List processing is provided as a hardware option for the Serial Highway Driver and more » is supported by a list sequencer module, an auxiliary crate controller, as well as software device drivers. A new crate controller with a ribbon-cable bus interface uses balanced-line transmission and supports a bus length to 500 feet.
The Serial Highway enhancements provide at least a five-fold improvement in effective throughput and rival the Parallel Branch Highway in that regard. These new products fall into three basic categories: enhancements to the CAMAC Serial Highway, new CAMAC crate controllers, and software drivers. A family of CAMAC-based interface products has been developed that supports high data throughput while providing the flexibility to meet the particular application.