نتایج جستجو برای: dispersal barrier

تعداد نتایج: 109429  

Journal: :Molecular biology and evolution 2003
Chi-Hing C Cheng Liangbiao Chen Thomas J Near Yumi Jin

The fish fauna of the Antarctic Ocean is dominated by five endemic families of the Perciform suborder Notothenioidei, thought to have arisen in situ within the Antarctic through adaptive radiation of an ancestral stock that evolved antifreeze glycoproteins (AFGPs) enabling survival as the ocean chilled to subzero temperatures. The endemism results from geographic confinement imposed by a massiv...

2015
Milica Lakovic Hans-Joachim Poethke Thomas Hovestadt Sam C Banks

Dispersal is a life-history trait affecting dynamics and persistence of populations; it evolves under various known selective pressures. Theoretical studies on dispersal typically assume 'natal dispersal', where individuals emigrate right after birth. But emigration may also occur during a later moment within a reproductive season ('breeding dispersal'). For example, some female butterflies fir...

Journal: :تحقیقات نظام سلامت 0
آذر طل دکتری تخصصی، گروه آموزش بهداشت و ارتقای سلامت، دانشکده بهداشت، دانشگاه علوم پزشکی تهران، تهران، ایران فرشته مجلسی استاد، گروه آموزش بهداشت و ارتقای سلامت، دانشکده بهداشت، دانشگاه علوم پزشکی تهران، تهران، ایران عباس رحیمی فروشانی دانشیار، گروه آمار و اپیدمیولوژی، دانشکده بهداشت، دانشگاه علوم پزشکی تهران، تهران، ایران داود شجاعی زاده استاد، گروه آموزش بهداشت و ارتقای سلامت، دانشکده بهداشت، دانشگاه علوم پزشکی تهران، تهران، ایران بهرام محبی استادیار، گروه قلب و عروق، دانشکده پزشکی، دانشگاه علوم پزشکی تهران، تهران ، ایران

background: psychological and behavioral domains are important in coping with type ii diabetes. this study was conducted to assess supportive and coping obstacles in living with type ii diabetes among patients who visited hospitals affiliated to tehran university of medical sciences (tums). methods: this was a cross-sectional study with 600 subjects who participated in the study. data collectio...

Journal: :Heredity 2001

2013
Wei-Ting Lin Chih-hao Hsieh Takeshi Miki

Theories and empirical evidence suggest that random dispersal of organisms promotes species coexistence in spatially structured environments. However, directed dispersal, where movement is adjusted with fitness-related cues, is less explored in studies of dispersal-mediated coexistence. Here, we present a metacommunity model of two consumers exhibiting directed dispersal and competing for a sin...

Journal: :Journal of virology 2015
Anthony C Fries Jacqueline M Nolting Andrew S Bowman Xudong Lin Rebecca A Halpin Eric Wester Nadia Fedorova Timothy B Stockwell Suman R Das Vivien G Dugan David E Wentworth H Lisle Gibbs Richard D Slemons

UNLABELLED While geographic distance often restricts the spread of pathogens via hosts, this barrier may be compromised when host species are mobile. Migratory waterfowl in the order Anseriformes are important reservoir hosts for diverse populations of avian-origin influenza A viruses (AIVs) and are assumed to spread AIVs during their annual continental-scale migrations. However, support for th...

2007
Jeffrey M. Leis Rebecca N. Johnson

Determining the scale of larval dispersal and population connectivity in demersal fishes is a major challenge in marine ecology. Historically, considerations of larval dispersal have ignored the possible contributions of larval behaviour, but we show here that even young, small larvae have swimming, orientation and vertical positioning capabilities that can strongly influence dispersal outcomes...

2014
Thomas R. Etherington George L. W. Perry Phil E. Cowan Mick N. Clout

Dispersal costs need to be quantified from empirical data and incorporated into dispersal models to improve our understanding of the dispersal process. We are interested in quantifying how landscape features affect the immediately incurred direct costs associated with the transfer of an organism from one location to another. We propose that least-cost modelling is one method that can be used to...

2004
Geoff Wild Peter D. Taylor

We investigate the co-evolutionary relationship between sex-ratio bias and sex-specific dispersal behaviour using an inclusive fitness approach. We consider two models: (i) DDM, in which dispersal of both sexes occurs before mating; and (ii) DMD, in which male dispersal precedes mating and female dispersal follows mating. Under DDM, at equilibrium, there is no bias in either the sex ratio or th...

Journal: :Biological reviews of the Cambridge Philosophical Society 2016
Scott C Burgess Marissa L Baskett Richard K Grosberg Steven G Morgan Richard R Strathmann

Recent syntheses on the evolutionary causes of dispersal have focused on dispersal as a direct adaptation, but many traits that influence dispersal have other functions, raising the question: when is dispersal 'for' dispersal? We review and critically evaluate the ecological causes of selection on traits that give rise to dispersal in marine and terrestrial organisms. In the sea, passive disper...

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