Avancerad sökning

Hittade 5 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Causes and consequences of blood parasite infections in birds

    Författare :Martin Stjernman; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal physiology; Djurfysiologi; Parasitologi människa och djur ; Parasitology human and animal ; maternal transfer; stabilising selection; parasite resistance; parasites; trade-off; cost of reproduction; Ficedula hypoleuca; pied flycatcher; Haemoproteus; blue tit; Parus caeruleus;

    Sammanfattning : Parasites are ubiquitous and can cause significant fitness reductions to their hosts. Therefore, selection for the evolution of host resistance should be strong. However, resistance may be costly and should be traded-off against other fitness related traits. LÄS MER

  3. 2. Causes and consequences of quantitative trait variation for reproductive performance in hole nesting birds

    Författare :Robert Przybylo; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; timing of breeding; climate change; parental and territorial quality; morphology; sexual size dimorphism; intersexual niche differentiation; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis examines the causes and consequences of environmental variability and individual morphological differences on breeding success and survival in three hole nesting birds.An analysis of directional and stabilising natural selection in Collared Flycatchers (Ficedula albicollis) suggested that forces of selection acting on quantitative traits are weak and cannot explain the observed sexual size dimorphism (SSD) in this species. LÄS MER

  4. 3. Genetic and environmental factors influencing growth and survival in willow tits, Parus montanus

    Författare :Anna Thessing; Tomas Pärt; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; zoologi; Zoology;

    Sammanfattning : This thesis concerns with the relationship between genetic and environmental attributes and their influence on offspring growth and survival in willow tits (Parus montanus). It also investigates the occurrence of directional or stabilising selection on body size during different life stages or times of the year. LÄS MER

  5. 4. Genomics of heterosis and egg production in White Leghorns

    Författare :Esinam Amuzu; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Crossbreeding  is  practiced  extensively  in  commercial  breeding  programs  of many  plant and animal species, in order to exploit heterosis, breed complementarity, and  to  protect  pure  line  genetic  material.  The  success  of  commercial  crossbreeding  schemes depends on identifying and using the right combination of breeds, lines or  varieties  that  produce  the  desired  crossbred  offspring. LÄS MER

  7. 5. Molecular Mechanisms Influencing the Performance of Amorphous Formulations for Poorly Water-Soluble Drugs

    Författare :Khadijah Edueng; Christel Bergström; Denny Mahlin; Michael Hageman; Uppsala universitet; []
    Nyckelord :Amorphous formulation; crystallisation; supersaturation; glass-forming ability; physical stability; glass stability; spray-dried solid dispersion; dissolution; promiscuous glass former; poorly-soluble drug; solid-to-solid; solution-mediated; particle-associated; Farmaceutisk vetenskap; Pharmaceutical Science;

    Sammanfattning : Crystallisation is a concern for amorphous formulation because it compromises the solubility-enhancing benefit gained from amorphisation. Traditionally, amorphous formulation had been designed primarily based on trial-and-error approach. LÄS MER