Image processing with VLSI

The development and implementation of systems for the more complex realtime image processing and scene understanding tasks, such as robot vision and remote surveillance, calls for faster computation than that possible using the traditional serial computer. The advent of VLSI has made feasible the consideration of more specialized processing architectures, designed to support these datarates, while keeping systems compact and relatively cheap. Two approaches are discussed: the use of a programmable processor array, and the customizing of image processing algorithms in silicon. This paper examines designs based upon each approach in the light of the techniques and constraints of VLSI. In particular we describe in some detail an example of a VLSI parallel array processor, the Grid (GEC rectangular image and data processor), and a number of special-purpose CMOS/SOS chips based on systolic design techniques.     

Protein structure alignment by incremental combinatorial extension (CE) of the optimal path

A new algorithm is reported which builds an alignment between two protein structures. The algorithm involves a combinatorial extension (CE) of an alignment path defined by aligned fragment pairs (AFPs) rather than the more conventional techniques using dynamic programming and Monte Carlo optimization. AFPs, as the name suggests, are pairs of fragments, one from each protein, which confer structure similarity. AFPs are based on local geometry, rather than global features such as orientation of secondary structures and overall topology. Combinations of AFPs that represent possible continuous alignment paths are selectively extended or discarded thereby leading to a single optimal alignment. The algorithm is fast and accurate in finding an optimal structure alignment and hence suitable for database scanning and detailed analysis of large protein families. The method has been tested and compared with results from Dali and VAST using a representative sample of similar structures. Several new structural similarities not detected by these other methods are reported. Specific one-on-one alignments and searches against all structures as found in the Protein Data Bank (PDB) can be performed via the Web at http://cl.sdsc.edu/ce.html.     

Specificities of red cell membrane sites transporting three long chain fatty acids

We studied the specificities of human red cell membrane bindings of three long chain fatty acids, palmitic- arachidonic- and oleic acid, using resealed membranes, ghosts. Previously estimated binding capacities, affinities and inside/outside distributions suggest separated binding sites. This possibility is explored by estimating the binding properties of one fatty acid in the presence of one or two of the others. Binding capacities, nmol g-1 ghosts, of palmitic and arachidonic acid estimated simultaneously vs. separately are 27.4 +/- 2.7 vs. 29.0 +/- 2.1 (P < 0.6) and 6.5 +/- 0.6 vs. 5.5 +/- 0.5 (P < 0.2) respectively. The corresponding estimates for oleic- and palmitic acid are 36.5 +/- 2.0 vs. 34.0 +/- 2.2 (P < 0.4) and 28.4 +/- 1.8 versus 29.1 +/- 2.1 (P < 0.8). The binding sites are therefore independent. For each of the three fatty acids in the absence or in the presence of one or two of the others, the inside/outside distributions of the binding sites and the membrane transfer rate constants are elucidated by exchange efflux kinetics at 0 degrees C from ghosts with and without enclosed albumin. Packed ghosts loaded with radioactive acids are injected rapidly into a large volume of vigorously stirred buffer with albumin. With a resolution time of about 1-sec serial filtered ghost-free aliquots are collected and counted. The analyses show that palmitic- and oleic acid sites of transport are entirely independent but do not exclude that palmitic- and/or oleic acid binding may diminish the arachidonic acid affinity a little. The diversity combined with specificity suggests that the transport sites for long chain fatty acids are protein-determined microdomains of phospholipids.     

Photooxidation of P-960 and photoreduction of P-800 (bacteriopheophytin b-800) in reaction centers from Rhodopseudomonas viridis

CT scans of 9 patients with orbital pseudotumor (bilateral in 6 and unilateral in 3) showed findings distinct from those observed in Graves' ophthalmopathy. In bilateral involvement, they ranged from localized mass lesions to complete obiliteration of normal orbital CT anatomical landmarks; diffuse or multifocal lesions involving the posterior globe and muscle insertions were most typical of the diagnosis. However, findings in unilateral psedotumor may be indistinguishable from orbital mass lesions other than Graves' ophthalmopathy. Serial CT scans were used to show progression of disease and response to treatment.     

The ultrastructural and functional expression of the hepatocyte genome under conditions of prolonged inhibition of protein biosynthesis by cycloheximide. V]

A review of 76 Southampton children with Henoch-Sch?nlein purpura has confirmed that there is no evidence of a streptococcal aetiology in the majority of cases of this disease. Among these patients the frequency of preceding respiratory infection of all kinds was only 7 percent greater than that in controls. Data on month of admission in four areas of England and Scotland show that the incidence of the disease is lowest in the June-August period. Contrary to previous findings there is no marked peak of incidence in any single month.