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91.
A simple method for the isolation and identification of the causative diphtheroid of erythrasma, Corynebacterium minutissimum, utilizes Muiller-Hinton Agar. 相似文献
92.
Stephen E. Fienberg 《Biological cybernetics》1970,7(6):227-229
Summary This paper presents a well-known stochastic model used to describe the firing or discharge pattern of a single neuron in terms of various input processes, and shows how the potential level of the neuron can be given by means of a diffusion equation approximation. There is a discussion of the adequacy of this approximation, and the paper concludes with a brief discussion of first passage time problems.Supported in part by a grant from the Alfred P. Sloan Foundation to the Committee on Mathematical Biology and by a grant of the Statistical Branch, Office of Naval Research to the Department of Statistics, University of Chicago. 相似文献
93.
Summary Microbodies (peroxisomes), a group of cytoplasmic organelles enriched in catalase, are demonstrated in the toad, Bufo marinus, by light and electron microscopy by means of a cytochemical staining procedure that demonstrates the peroxidatic activity of catalase with diaminobenzidine (DAB). Amphibian microbodies are similar to those of other classes in their fine structure and localization in hepatocytes and kidney, where they are prominent in the proximal tubular cells. Nucleoids are present only in renal microbodies. In the proximal renal tubule an unusual group of large brown granules are identified as lysosomes by their acid phosphatase, -glucosaminidase and -glucuronidase activities.This work was supported by U.S. Public Health Service Grants Nos. NS-06856 and HD 00674. We wish to thank Dr. Richard M. Hays who generously supplied us with toads; Dr. Alex B. Novikoff for making available facilities for ultramicrotomy, Miss Betty De Prest for technical assistance; Miss Marianne Van Hooren for preparation of the photomicrographs. 相似文献
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95.
Incidence of Clostridium botulinum Type E in Salmon and Other Marine Fish in the Pacific Northwest 总被引:4,自引:3,他引:1 下载免费PDF全文
Salmon, sole, cod, oysters, clams, and crabs from ocean waters along the coast of Oregon and Washington were examined for the presence of Clostridium botulinum type E. The organism was detected by identification of the type E toxin in enrichment cultures of the viscera of individual fish. Of 369 salmon specimens, 48 yielded cultures containing toxin lethal to mice, and almost half of the toxic cultures were shown to contain botulinal toxin, chiefly type E. Eighteen of 113 sole and cod specimens, 4 of 22 Dungeness crab specimens, 5 of 16 oyster specimens, and 27 of 115 clam specimens gave rise to cultures containing botulinal toxin which was usually type E, although types A and B were occasionally encountered. 相似文献
96.
The usual assumption in treating the diffusion of ions in an electric field has been that the movement of each ion is independent of the movement of the others. The resulting equation for diffusion by a succession of spontaneous jumps has been well stated by Parlin and Eyring. This paper will consider one simple case in which a different assumption is reasonable. Diffusion of monovalent positive ions is considered as a series of jumps from one fixed negative site to another. The sites are assumed to be full (electrical neutrality). Interaction occurs by the displacement of one ion by another. An ion leaves a site if and only if another ion, not necessarily of the same species, attempts to occupy the same site. Flux ratios and net fluxes are given as functions of the electrical potential, concentration ratios, and number of sites encountered in crossing the membrane. Quantitative comparisons with observations of Hodgkin and Keynes are presented. 相似文献
97.
Sidney Roston 《Bulletin of mathematical biology》1962,24(2):129-135
Variation in the heart rate and the duration of systole modifies the pressures in the two-chambered model of the cardiovascular
system by several mechanisms. The theoretical results indicate that prediction of chamber pressures would require moment-to-moment
knowledge of the resistances peripheral to each chamber in addition to the cardiac output per cycle, cycle length, and duration
of systole. Lengthening of systole with increase in cycle length—a physiologically observed relationship—theoretically stabilizes
the end-diastolic pressure in the ascending aorta and may be a homeostatic mechanism to steady blood flow through the coronary
arteries. 相似文献
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