Cooperative Regulation of the Activity of Factor Xa within Prothrombinase by Discrete Amino Acid Regions from Factor Va Heavy Chain†

ABSTRACT: The prothrombinase complex catalyzes the activation of prothrombin to R-thrombin. We have repetitively shown that amino acid region 695DYDY698 from the COOH terminus of the heavy chain of factor Va regulates the rate of cleavage of prothrombin at Arg271 by prothrombinase. We have also recently demonstrated that amino acid region 334DY335 is required for the optimal activity of prothrombinase. To assess the effect of these six amino acid residues on cofactor activity, we created recombinant factor Va molecules combining mutations at amino acid regions 334–335 an

DARPA Parallel Architecture Benchmark Study

In intensive work over a four-week period in the summer of 1986, seven problems were studied and implemented on the Butterfly. The problems were Inspired by various capabilities in computer vision, and were proposed as benchmarks for a DARPA workshop on parallel architectures. They were: convolution and zero-crossing detection for edges, edge tracking, connected component labeling, hough transform, three computational geometry problems (convex hull, voronoi diagram, and minimum spanning tree), three-dimensional visibility calculations, subgraph isomorphism and minimum cost path calculation. BPRs 10, 11, and 14 are detailed reports on three of the problems. BPR13 contains the conclusions of the study and writeups of the work not covered in other BPRs