共查询到20条相似文献,搜索用时 46 毫秒
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We show that the steady states of the White and Comiskey [E. White, C. Comiskey, Heroin epidemics, treatment and ODE modelling, Math. Biosci. 208 (2007) 312-324.] model of heroin epidemics are stable. 相似文献
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N. Rashevsky 《Bulletin of mathematical biology》1959,21(1):97-100
In line with a recent suggestion by the author (Bull. Math. Biophysics,20, 267–73, September, 1958) that not only does the organism as a whole map on the primordial, but that each organ can also
be thus mapped, it is shown that the previously introduced abstract spaces, which represent an organism, contain subspaces
which map continuously on the space of the primordial. Several theorems about those subspaces are proven. 相似文献
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Stephen Beckerman 《Human ecology: an interdisciplinary journal》1984,12(2):203-206
Stocks (1983) suggested four reasons which motivate the planting of South American tropical forest swidden crops in concentric rings. His third proposal, that of protection from insect pests, is examined in the light of recent fieldwork with the Bari, and reformulated to suggest that protection from mammalian pests may be a more accurate explanation of the value of this type of field architecture. 相似文献
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N. Rashevsky 《Bulletin of mathematical biology》1965,27(3):311-313
In a preceding paper (Bull. Math. Biophysics,27, 175–185) the distribution function ofφ=? 1-? 2,—the difference of excitations in the two mutually inhibiting centers, has been derived in terms of the distribution functionsf 1(? 1) andf 2(? 2) of the two excitations. In the present note some properties of the distribution functionf(?) in terms of the propertiesf 1(? 1) andf 2(? 2) are derived. 相似文献
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N. Rashevsky 《Bulletin of mathematical biology》1948,10(4):201-204
The approximation method for solving diffusion problems is generalized to enable computation not only of the fundamental frequency,
but also of higher harmonics in certain types of periodic solutions. 相似文献
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Louis G. Vargo 《Bulletin of mathematical biology》1966,28(3):375-378
The Volterra theory of two competing populations is extended to the contemporary social problem of crime control. Domains
of stability for the time dependence of the numbers in the criminal and enforcement groups are exposed by a numerical example.
Both augmentation and reduction of enforcement can produce a stable system. Average values of the ratio of members in each
group show great sensitivity to the control policies adopted by the remaining sector of the total population. 相似文献
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A note on Wallemia sebi 总被引:1,自引:0,他引:1
R. T. Moore 《Antonie van Leeuwenhoek》1986,52(2):183-187
A review of the available information on the monotypic genus Wallemia supports the interpretation that W. sebi is probably a basidiomycete and may be a teleomorph. It has dolipore/parenthesome septa similar to those found in the suborder Tremellineae, except that the associated parenthesome vesicles are very small and composed of a single membrane. A conjectural interpretation is made that the spore chains, which are composed of repeating sets of four, are meiospores generated from a permanently diploid mother cell that divides repeatedly to generate meiocyte daughter cells. 相似文献
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H. D. Landahl 《Bulletin of mathematical biology》1944,6(2):77-78
A neural mechanism is described which provides for a perception which is invariant with respect to movement of the stimulus. 相似文献
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N. Rashevsky 《Bulletin of mathematical biology》1965,27(2):311-313
In a preceding paper (Bull. Math. Biophysics,27, 175–185) the distribution function ofφ=ɛ 1-ɛ 2,—the difference of excitations in the two mutually inhibiting centers, has been derived in terms of the distribution functionsf 1(ɛ 1) andf 2(ɛ 2) of the two excitations. In the present note some properties of the distribution functionf(ϕ) in terms of the propertiesf 1(ɛ 1) andf 2(ɛ 2) are derived. 相似文献