Sökning: "population cycles"

Visar resultat 16 - 20 av 85 avhandlingar innehållade orden population cycles.

  1. 16. Genetic Variation and Migration of Waders

    Författare :Liv Wennerberg; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mtDNA sequencing; microsatellite analysis; Dunlin; Calidris alpina; Curlew Sandpiper; Calidris ferruginea; White-rumped Sandpiper; Calidris fuscicollis; carbon isotope ratios; Zoologi; Zoology; Ecology; bird migration; population genetics; Ekologi; Animal ecology; Djurekologi;

    Sammanfattning : The migratory behaviour of birds has received much scientific interest, though many questions still remain unsolved. One of the reasons for this is the difficulty of following the birds as they move between breeding and wintering localities. Populations may mix on migration and the origin of individual birds is difficult to assess. LÄS MER

  3. 17. Functional genomics of diapause in two temperate butterflies

    Författare :Peter Pruisscher; Karl Gotthard; Dieter Ebert; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diapause induction; adaptation; genomics; transcriptomics; populationsgenetik; Population Genetics;

    Sammanfattning : Natural selection will act on a given phenotype to maximize fitness in a particular environment, even if this would result in reduced fitness in other environments. In insects some of the strongest selection pressures act on timing life cycles to seasonal variation in environmental conditions, in order to maximize growth, reproduction, and to anticipate the onset of winter. LÄS MER

  4. 18. Brood sex ratio and sex differences in Tengmalm’s owl : (Aegolius funereus)

    Författare :Tim Hipkiss; Gary Bortolotti; Umeå universitet; []
    Nyckelord :Aegolius funereus; avian CHD1 genes; brood sex ratio; differential mortality; nomadism; northern Sweden; sexual size dimorphism; sibling rivalry; supplementary feeding; vole cycles; zooekologi; Animal Ecology;

    Sammanfattning : Males and females differ in morphology and behaviour, so that selection acts differently on the two sexes. This changes the relative reproductive success of males and females, and it is beneficial for parents to bias the sex ratio of their broods in favour of the sex with the best survival and breeding prospects. LÄS MER

  5. 19. Processes and factors governing benthic community dynamics—environmental change in the Baltic Sea

    Författare :Christian Sommer; Sara Sjöling; Patrik Dinnétz; Inger Porsch Hällström; Alexander Eiler; Södertörns högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Benthic communities; Baltic Sea; biodiversity; community composition; environmental change; environmental genomics; microbial ecology; Major Baltic Inflow; meta-population; Environmental Studies; Miljövetenskapliga studier; Östersjö- och Östeuropaforskning; Baltic and East European studies;

    Sammanfattning : As drivers of biogeochemical cycles and nutrient recycling, such as carbon turnover, the microbial community is essential in sustaining functioning ecosystems. Together with the metazoan community, the microbial community constitute the majority of all life in the benthos. LÄS MER

  7. 20. On causes of neck and shoulder pain in the general population

    Författare :Kerstin Fredriksson; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :bio-psychosocial perspective; interactions; occupational; non-occupational; validity; reliability; changes; perceived physical workload; retrospective; gender;

    Sammanfattning : The aim of this thesis was to identify risk factors for neck/shoulder pain and disorders. In accordance with the bio-psychosocial perspective used, both physical and psychosocial factors were studied at work as well as during leisure-time. LÄS MER