Diabetic retinopathy (DR) is a leading cause of preventable blindness in adults. To identify genetic contributions in DR, we studied 2071 type 2 diabetics. We first conducted a genome-wide ...association study of 1007 individuals, comparing 570 subjects with ≥8 years duration without DR (controls) with 437 PDR (cases) in the Chinese discovery cohort. Cases and controls were similar for HbA1c, diabetes duration and body mass index. Association analysis with imputed data identified three novel loci: TBC1D4-COMMD6-UCHL3 (rs9565164, P = 1.3 × 10(-7)), LRP2-BBS5 (rs1399634, P = 2.0 × 10(-6)) and ARL4C-SH3BP4 (rs2380261, P = 2.1 × 10(-6)). Analysis of an independent cohort of 585 Hispanics diabetics with or without DR though did not confirm these signals. These genes are still of particular interest because they are involved in insulin regulation, inflammation, lipid signaling and apoptosis pathways, all of which are possibly involved with DR. Our finding nominates possible novel loci as potential DR susceptibility genes in the Chinese that are independent of the level of HbA1c and duration of diabetes and may provide insight into the pathophysiology of DR.
The error threshold for fault-tolerant quantum computation with concatenated encoding of qubits is penalized by internal communication overhead. Many quantum computation proposals rely on nearest ...neighbor communication, which requires excess gate operations. For a qubit stripe with a width of L+1 physical qubits implementing L levels of concatenation, we find that the error threshold of 2.1/spl times/10/sup -5/ without any communication burden is reduced to 1.2/spl times/10/sup -7/ when gate errors are the dominant source of error. This /spl sim/175/spl times/ penalty in error threshold translates to an /spl sim/13/spl times/ penalty in the amplitude and timing of gate operation control pulses.
Current fiber optic networks effectively provide local connectivity among end user computing devices, and can serve as backbone fabric between LAN subnets across campus and metropolitan areas. ...However, combining both stream service (in which ATM excels) and low latency datagram service (in which cluster networks like Myrinet and POLO excel) has been difficult to realize. This paper describes a new wavelength division multiplexed (WDM) fiber optic network that supports both stream and datagram service and extends reach and functionality of low-latency, high bandwidth workstation clusters to a campus and MAN setting. The novel concept is based on combining the rich interconnect structure of WDM fiber optics with the low-latency mesh of crossbar switches recently developed for workstation groups. This system, called the Supercomputer Supernet (SSN) achieves a high level of performance by replacing the point-to-point copper wire links with a parallel channel (WDM) fiber optic interconnect system. The novel scheme interconnects asynchronous wormhole routing switches used in parallel supercomputers via multi-channel WDM fiber optic links embedded in to an optical star (or tree) "physical" topology, WDM will be used to subdivide the very large fiber bandwidth into several channels, each of Gb/s bandwidth, WDM channels (supporting also time division multiplexing) will be established between modules, thus defining a dense "virtual" interconnection topology, which is dynamically reconfigurable and responds to changing traffic patterns. A pool of channels will be set aside for direct, end-to-end connections between crossbars, providing circuit-switched service for real-time traffic applications.
A DC-motor driven beam-deflector is to be controlled such that the beam moves with constant velocity for 12 ms out of a 20-ms period before swinging back to the original position. One control system ...must serve any deflector without retuning. The problem is difficult because the dynamics vary from one deflector to another. It is found that a closed-loop system with poles in a Bessel filter configuration will satisfy the specifications. A straightforward pole-placement design is insufficiently robust. Redesigning it yields greater, but still insufficient, robustness against the known extent of plant parameter variation. The problem is solved by adding an adaptive control loop.< >
PDF
