Sökning: "biologi"
Visar resultat 11 - 15 av 6249 avhandlingar innehållade ordet biologi.
11. Biodiversity and Species Extinctions in Model Food Webs
Sammanfattning : Many of the earth’s ecosystems are experiencing large species losses due to human impacts such as habitat destruction and fragmentation, climate change, species invasions, pollution, and overfishing. Due to the complex interactions between species in food webs the extinction of one species could lead to a cascade of further extinctions and hence cause dramatic changes in species composition and ecosystem processes. LÄS MER
12. Comparative Seed Morphology and Phylogenetics : Case Studies in Basal Angiosperms (ANITA) and Asterids (Lysimachia, Ericales)
Sammanfattning : The first half of the thesis deals with the seed morphology of members of the ANITA grade at the base of the angiosperm phylogeny (Amborella, Nymphaeales, Illiciales, Trimeniaceae, and Austrobaileyaceae), especially Illiciaceae and Schisandraceae. Seed characters support a major division between the New World and Old World species of Illicium. LÄS MER
13. Spatial Modelling of Coastal Fish – Methods and Applications
Sammanfattning : Environmental factors influence species and habitats on multiple scales creating a mosaic of distribution patterns. Studying factors shaping these patterns are central to our understanding of population dynamics and ultimately ecosystem functioning. LÄS MER
14. Cyanobacterial Hydrogen Metabolism : Regulation and Maturation of Hydrogenases
Sammanfattning : In times with elevated CO2 levels and global warming there is a need of finding alternatives to carbon based energy carriers. One such environmental friendly solution could be H2 produced by living organisms. LÄS MER
15. Domestication Effects on the Stress Response in Chickens : Genetics, Physiology, and Behaviour
Sammanfattning : Animal domestication, the process where animals become adapted to living in proximity to humans, is associated with the alteration of multiple traits, including decreased fearfulness and stress response. With an estimated population of 50 billion, the domesticated chicken is the most populous avian species in the world. LÄS MER