نتایج جستجو برای: type population dynamics

تعداد نتایج: 2324559  

2017
Thomas Gueudr'e David Martin

Essential to each other, growth and exploration are jointly observed in populations, be it alive such as animals and cells or inanimate such as goods and money. But their ability to move, crucial to cope with uncertainty and optimize returns, is tempered by the space/time properties of the environment. We investigate how the environment shape optimal growth and population distribution in such c...

2007
Pablo Munguia Don R. Levitan

In metapopulations, the maintenance of local populations can depend on source–sink dynamics, where populations with positive growth rate seed populations with negative growth rate. The pattern and probability of successful dispersal among habitats can therefore be crucial in determining whether local populations will become rare or increase in abundance. We present here data on the dispersal st...

2016
Nicolas Grosjean Thierry Huillet

Motivated by issues arising in population dynamics, we consider the problem of iterating a given analytic function a number of times. We use the celebrated technique known as Carleman linearization that turns (for a certain class of functions) this problem into simply taking the power of a real number. We expand this method, showing in particular that it can be used for population models with i...

2010
Masahiro Anazawa

This study investigates the effect of competition between individuals on population dynamics when they compete for different resources during different seasons or during different growth stages. Individuals are assumed to compete for a single resource during each of these periods according to one of the following competition types: scramble, contest, or an intermediate between the two. The effe...

Journal: :PloS one 2016
James F Saracco Paul Radley Peter Pyle Erin Rowan Ron Taylor Lauren Helton

Remote tropical oceanic islands are of high conservation priority, and they are exemplified by range-restricted species with small global populations. Spatial and temporal patterns in rainfall and plant productivity may be important in driving dynamics of these species. Yet, little is known about environmental influences on population dynamics for most islands and species. Here we leveraged avi...

2008
Paul A. Toro Amy Dworsky Patrick J. Fowler

In this paper, the authors cite research indicating that youth may be the single age group most at risk of becoming homeless, yet comparatively little research has been done in the past decade on this vulnerable population. Some important progress has been made, including longitudinal studies on youth “aging out” of foster care. After reviewing the characteristics of homeless youth, the authors...

Journal: :Human biology 2009
Felix Riede

Although difficult to estimate for prehistoric hunter-gatherer populations, demographic variables-population size, density, and the connectedness of demes-are critical for a better understanding of the processes of material culture change, especially in deep prehistory. Demography is the middle-range link between climatic changes and both biological and cultural evolutionary trajectories of hum...

2007
Alden Speare Michael Rendall Roger Avery Frances Goldscheider

This paper is concerned with issues of measurement of poverty rates among the elderly population and with the alleviation of that poverty by means of shared living arrangements. Specifically, we estimate effects of taking account of assets as well as income, of including in income government subsidies on food, rent, and household energy, and of setting higher poverty thresholds. The effects of ...

Journal: :iranian red crescent medical journal 0
giti ozgoli department of reproductive health and midwifery, faculty of medical sciences, tarbiat modares university, tehran, ir iran saeideh ziaei department of reproductive health and midwifery, faculty of medical sciences, tarbiat modares university, tehran, ir iran; department of reproductive health and midwifery, faculty of medical sciences, tarbiat modares university, tehran, ir iran. tel: +98-2122190488, fax: +98-2122190684 fazlollah ahmadi nursing department, faculty of medical sciences, tarbiat modares university, tehran, ir iran mahyar azar department of psychiatry, faculty of medicine, shahid beheshti university of medical sciences, tehran, ir iran

background: no study has been conducted yet on the process of adjustment of wives with their husbands’ erectile dysfunction in the transitional stages, and there is lack of understanding of this process in iran. objectives: a qualitative, grounded-theory study was designed to examine the process of adjustment of wives with their husbands’ erectile dysfunction in transitional stages. materials a...

Journal: :Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 2017

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید