Jose A. C. C. Medeiros

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The branching angles and relative diameters of blood vessels in 51 arterial bifurcations in the retina of a normal human eye were measured. In eight other bifurcations, only the total branching angles were measured. The results are compared with theoretical predictions in an attempt to understand the physiological principles governing branching in the(More)
  • Paolo D 'odorico, Jose D Fuentes, Marcy E Litvak, D P C Peters, P Citation: D 'odorico, J D Fuentes +6 others
  • 2010
Woody plant encroachment is affecting vegetation composition in arid grasslands worldwide and has been associated with a number of environmental drivers and feedbacks. It has been argued that the relatively abrupt character (both in space and in time) of grassland-to-shrubland transitions observed in many drylands around the world might result from positive(More)
A systematic electron microscopic study was made of the structure of foveal cones of Macaca spp. Transverse sections of inner (IS) and outer segments (OS) were made in sequence, from the pigment epithelial zone (PEZ) to the outer limiting membrane (OLM). The smallest diameters of hundreds of cone sections were measured from electron micrographs with a Zeiss(More)
PURPOSE This study was designed to investigate colonic spike bursts regarding 1) their migration behavior, 2) their pressure correlates, and 3) comparing colonic short spike bursts with spike bursts from migrating myoelectric complex from the small bowel. METHODS Rectosigmoid electromyography and manometry were recorded simultaneously in seven normal(More)
Novel retinal irradiation techniques for laser damage studies are described; these are straightforward applications of the Fourier transform properties of an optical system. Interposing an appropriate diffracting screen between the laser source and the test eye enables one to simultaneously induce a number of discrete and precisely located retinal exposures(More)
Scanning electron microscopic (SEM) observations of the rabbit retinal pigment epithelium (RPE) are reported both for normal tissue and for tissue subjected to laser radiation. In normal RPE, cells were observed to be closely packed and to have the characteristic hexagonal shape. The microvilli were abundant and of two types. Suprathreshold lesions were(More)
High resolution x-ray lithographic studies of cells from chick embryo hearts dried by the CO2 critical point method have been made with soft x-ray radiation of different wavelengths. A marked difference in the relief replica in polymethyl methacrylate (PMMA) resulting from the differential absorption by the dried cells of carbon K alpha radiation at 4.48 nm(More)
In the retina from an eye enucleated for choroidal melanoma apposed rod outer segments were seen by transmission electron microscopy to be fusing together in groups by the confluence of their plasma membranes and the formation of cytoplasmic bridges between adjacent outer segments. These fusions were seen in areas distant from the melanoma but where the(More)
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