Sökning: "Population"

Visar resultat 21 - 25 av 7801 avhandlingar innehållade ordet Population.

1. 21. Risk factors for atrial fibrillation in population-based studies : Epidemiological perspectives

   Författare :Linda Johnson; Internmedicin - epidemiologi; []
   Nyckelord :Atrial fibrillation; Fasting plasma insulin; forced expiratory volume; glucose; hypertension; lung volumes; population; premature atrial contractions; risk factors; spirometry; supraventricular extrasystoles; supraventricular tachycardias systolic blood pressure; weight;

   Sammanfattning : Atrial fibrillation (AF) is common among the elderly, and has serious consequences such as stroke and increased mortality. Not all of the population attributable risk for AF is explained by known risk factors. LÄS MER

3. 22. Effects of size-dependent predation and competition on population and community dynamics

   Författare :Karin Nilsson; Lennart Persson; Volker Rudolf; Umeå universitet; []
   Nyckelord :size-structure; cannibalism; resource competition; predation; emergent facilitation; population regulation; population dynamics; overcompensation; density-dependence; cycles; zooekologi; Animal Ecology;

   Sammanfattning : Most animals grow substantially during their lifetime and change in competitive ability, predatory capacity and their susceptibility to predation as they grow. This thesis addresses the implications of this on regulation and dynamics within populations as well as between population interactions. LÄS MER

4. 23. Population-level consequences of variation

   Författare :Lena Wennersten; Anders Forsman; Olof Leimar; Deepa Agashe; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; colour polymorphism; diversity; establishment success; evolutionary changes; population-level consequences; predation risk; Tetrix subulata; variation; Evolutionary Biology; Evolutionsbiologi;

   Sammanfattning : Consequences of within population variation have recently attracted an increased interest in evolutionary ecology research. Theoretical models suggest important population-level consequences, but many of these predictions still remain to be tested. LÄS MER

5. 24. Population History and Non-invasive Monitoring : Use of low copy number DNA in Conservation Genetics

   Författare :Øystein Flagstad; Ettore Randi; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; genetic tagging; immigration; loss of genetic variability; non-invasive molecular techniques; population decline; Swayne’s hartebeest; wolf; wolverine; Biologi; Biology; Biologi; ekologisk botanik; Ecological Botany;

   Sammanfattning : Conservation genetics research is increasingly becoming an integrated part of the management of small and endangered populations. In this thesis I developed tools for genetic analysis of low copy number sources of DNA, such as old teeth from museum specimens as well as field-collected faeces and urine. LÄS MER

7. 25. Modelling animal populations

   Författare :Åke Brännström; Umeå universitet; []
   Nyckelord :population model; stochastic population model; population dynamics; discrete time model; Beverton-Holt model; Skellam model; Hassell model; Ricker model; first principles; coupled map lattice; CML; area integral; square function; Mathematics; matematik;

   Sammanfattning : This thesis consists of four papers, three papers about modelling animal populations and one paper about an area integral estimate for solutions of partial differential equations on non-smooth domains. The papers are: I. Å. Brännström, Single species population models from first principles. LÄS MER