Bradley A. Payne

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A surface manipulation technique that uses distance fields-scalar fields derived geometrically from surface models-to combine, modify, and analyze surfaces is presented. It is intended for application to complex models arising in scientific visualization. Computing distance from single triangles is discussed, and an optimized algorithm for computing the(More)
A flexible graphics system for displaying functional and anatomic data on arbitrary collections of surfaces on or within the brain is presented. The system makes it possible to show complex, convoluted surfaces with the shading cues necessary to understand their shapes; to vary viewpoint, object position, illumination, and perspective easily; to show(More)
Outlines for reconstructing object surfaces are traditionally drawn from sequential images in parallel planes. The method presented here instead supports complex object topologies by drawing contours from multiaxial image planes. Multiaxial triangulation of an object in a given data volume involves four steps. First, the user generates contours(More)
Evaluation of linearity, carry-over, precision, and accuracy of a Coulter Counter model S-Plus IV prototype showed that they meet the manufacturer's specifications. The instrument also was compared with an earlier model. Correlations of the lymphocyte and granulocyte values in the three-part differential count with manual eye-count and a Technicon Hemalog(More)
Rapid and convenient access to digital image archives, as well as archive-based computational tools, are fundamental to many hypothesis-driven investigations of brain anatomy and function in health and disease. The complexity and density of brain image data requires the design of intelligent tools which allow scientific and clinical data, collected at(More)
When a low platelet count is unexpected or is unaccompanied by signs or symptoms of hemorrhage, pseudothrombocytopenia should be suspected. The platelet number and morphologic features should be examined on a smear prepared from blood anticoagulated with EDTA. Platelet counts should be repeated either by obtaining a finger-stock specimen with an ammonium(More)
Experiments were undertaken to determine the in vivo utility of the mixed benzodiazepine ligand [3H]flunitrazepam and the selective peripheral benzodiazepine ligand [3H]PK 11195 [1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide] to outline the borders of rat C6 glial tumors in three dimensions. Intravenous injection of(More)
The authors compared four leukocyte differential counting methods with the National Committee for Clinical Laboratory Standards Reference Leukocyte Differential Method H20-T to determine the clinical sensitivity of the methods. The three-part differential performed by the Coulter Counter Model S-Plus IV and the Toa E-5000, when combined with instrument(More)
Digital brain mapping provides the techniques required for 3 dimensional (3D) reconstruction and display. This paper describes work which extends the data published in the Paxinos and Watson (1982) atlas of the rat brain to a computerized form. The product of these experiments is a 3D digital neuroanatomic atlas. The data were transformed from 2D outlines(More)
Three dimensional (3D) reconstructions of brain anatomy and physiology have greatly improved our understanding of complex spatial and densitometric relationships. The complexity and sophistication of these imaging techniques has steadily improved in the last few years and there are many situations in which the static display of 3D models contains more(More)