Results 251 to 260 of about 2,661,820 (292)
Some of the next articles are maybe not open access.
Dynamics of social populations
Nonlinear Analysis: Theory, Methods & Applications, 1997Two variations of the logistic model of population dynamics with threshold effects are proposed. The proporties of solutions of these models assigned by differential equations with three equilibria are investigated. The first model indicates that undercrowding can lead to eventual extinction while overcrowding will lead to persistence but at a level ...
Pingzhou Liu, Kondalsamy Gopalsamy
openaire +3 more sources
Journal of Theoretical Biology, 1995
Population dynamics is analyzed by means of the power series expansion of a decay ratio F(P) with respect to the continuation probability, P, of survival. The truncation of the higher terms of the series yields the Verhulst equation as a first approximation. The approximation for higher age yields a simple exponential decay law of population, while the
Kazumi Suematsu, Minoru Kohno
openaire +3 more sources
Population dynamics is analyzed by means of the power series expansion of a decay ratio F(P) with respect to the continuation probability, P, of survival. The truncation of the higher terms of the series yields the Verhulst equation as a first approximation. The approximation for higher age yields a simple exponential decay law of population, while the
Kazumi Suematsu, Minoru Kohno
openaire +3 more sources
The Population Dynamics and Conservation of Primate Populations
Conservation Biology, 1989Abstract: Primates are among the most threatened taxa, with more than half of all species in jeopardy. In this paper we develop population models to use the kind of data on wild primates that primatologists actually collect. Our survey of recentprimate journals suggests that the average field study uses 1.5 years of data from 50 animals The models are
Anna Marie Lees, Andrew P. Dobson
openaire +3 more sources
2006
Populations of insects can fluctuate dramatically through time in response to changing environmental conditions. Disturbances are particularly important to population dynamics, triggering outbreaks of some species and locally exterminating others.
openaire +3 more sources
Populations of insects can fluctuate dramatically through time in response to changing environmental conditions. Disturbances are particularly important to population dynamics, triggering outbreaks of some species and locally exterminating others.
openaire +3 more sources
Parasite population dynamics within a dynamic host population
Probability Theory and Related Fields, 1989We propose a stochastic process model for a parasite population living within a host population. The host population is described by an immigration-death process. The parasite population in one host is an immigration-birth-death-emigration process. The death of all parasites at the moment of death of their host is regarded as emigration.
E. Born, Klaus Dietz
openaire +2 more sources
On spatial population dynamics
Chaos, Solitons & Fractals, 2003In economics, two-dimensional flow models have been studied for: 1) transport commodities, 2) interregional trade in extended markets, 3) expenditure diffusion, 4) migration, 5) population reproduction and redistribution. In this paper, the author studies the dynamics of population reproduction and spatial distribution in terms of a two-dimensional ...
openaire +3 more sources
2018
Population increase, stability, or decrease are expressions of social forces and human interaction with the environment. Children's social and economic role varies from class to class and presents potential parents with an inverse proportion quandary: an extra member of the group versus the financial difficulties involved in bringing up an extra child,
openaire +2 more sources
Population increase, stability, or decrease are expressions of social forces and human interaction with the environment. Children's social and economic role varies from class to class and presents potential parents with an inverse proportion quandary: an extra member of the group versus the financial difficulties involved in bringing up an extra child,
openaire +2 more sources
11 The Dynamics of Population in Yugoslavia
Eastern European Economics, 1982A general review of population trends in Yugoslavia since the end of World War II is presented. Sections are included on natural population increase including fertility family planning and mortality; migration both internal and international; and changes in population characteristics.
openaire +2 more sources
1997
Voles, mouse-like animals whose populations swing wildly, cause enormous crop damage every year. Although no consensus has been reached concerning the causes of vole cycles, it is clear that no single extrinsic factor, such as weather or food availability, can be directly responsible for this phenomenon.
Bruce Hannon, Matthias Ruth
openaire +2 more sources
Voles, mouse-like animals whose populations swing wildly, cause enormous crop damage every year. Although no consensus has been reached concerning the causes of vole cycles, it is clear that no single extrinsic factor, such as weather or food availability, can be directly responsible for this phenomenon.
Bruce Hannon, Matthias Ruth
openaire +2 more sources
Dynamical Systems of Population Dynamics
2001After a short review of the the role of population dynamics in the formation of the theory of dynamical systems some recent developments are described, centered around work within the DANSE project: Reaction transport equations which are refinements of reaction diffusion equations, showing travelling front solutions and pattern formation, with ...
Johannes Müller, Karl-Peter Hadeler
openaire +2 more sources