Sökning: "divergent"

Visar resultat 11 - 15 av 388 avhandlingar innehållade ordet divergent.

1. 11. Genetic response to pollution in sticklebacks; natural selection in the wild

   Författare :Emma Lind; Mats Grahn; Marjorie Oleksiak; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Population genomics; genome scan; divergent selection; Gasterosteus aculeatus; Baltic Sea; pollution; funktionell zoomorfologi; Functional Zoomorphology;

   Sammanfattning : The last century, humans have been altering almost all natural environments at an accelerating rate, including the Baltic Sea that has highly eutrophicated areas and many coastal industries such as Pulp-mills. For animals living in a habitat that changes there are basically two alternatives, either to cope with the change or become locally extinct. LÄS MER

3. 12. Evolutionary Ecology of Floral Traits in Fragrant Orchids

   Författare :Elodie Chapurlat; Nina Sletvold; Jon Ågren; Magne Friberg; Kathleen Kay; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; agents of selection; diurnal and nocturnal pollination; divergent selection; field experiment; floral evolution; floral scent; Gymnadenia conopsea; Gymnadenia densiflora; Orchidaceae; phenotypic selection; pollinator-mediated selection; spatial variation; scent rhythm;

   Sammanfattning : Why are flowers so diverse? Much of floral evolution is thought to be driven by pollinator-mediated selection. However, the connection between macroevolutionary patterns of floral diversity and microevolutionary processes remains poorly understood. In this thesis, I have used the fragrant orchids Gymnadenia conopsea s.s. LÄS MER

4. 13. Ecology and Evolution of Resistance to Herbivory : Trichome Production in Arabidopsis lyrata

   Författare :Geir Løe; Jon Ågren; Kari Lehtilä; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Plant-animal interactions; herbivory; trichomes; plant resistance; plant defense; divergent selection; local adaptation; GLABROUS1; evolution; matrix population models; LTRE; Biologi; Biology; Biologi;

   Sammanfattning : In this thesis, I examine variation in occurrence and performance of glabrous and trichome-producing plants of the perennial herb Arabidopsis lyrata. I combine field studies and genetic analysis to (1) examine the function of trichomes as a resistance character in natural populations, (2) compare the magnitude of population differentiation in trichome-production and at putatively neutral marker loci, (3) examine the molecular genetic basis of trichome-production, and (4) quantify the effects of herbivore removal on population growth and relative performance of glabrous and trichome-producing plants. LÄS MER

5. 14. Nitric Oxide Reductase from Paracoccus denitrificans : A Proton Transfer Pathway from the “Wrong” Side

   Författare :Ulrika Flock; Pia Ädelroth; Simon de Vries; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; denitrification; nitric oxide reductase; heme copper oxidase superfamily; divergent member; proton transfer; electron transfer; single turnover; spectroscopy; periplasm; glutamate; proton pathway; Biochemistry; Biokemi; biokemi; Biochemistry;

   Sammanfattning : Denitrification is an anaerobic process performed by several soil bacteria as an alternative to aerobic respiration. A key-step in denitrification (the N-N-bond is made) is catalyzed by nitric oxide reductase (NOR); 2NO + 2e- + 2H+ → N2O + H2O. LÄS MER

7. 15. On some positive effects of swirling flow for the continuous cast mould billets

   Författare :Shavkat Kholmatov; Pär Jönsson; Simon Lille; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; swirling flow; round mould; divergent angle; aspect ratio; temperature distribution; velocity fluctuations; continuous casting of steel; mathematical modeling; CFD; Metallurgical process engineering; Metallurgisk processteknik;

   Sammanfattning : Continuous caster moulds are the last and most important stage in the steelmaking process, where inclusions can either be generated or removed. With increasing casting speed using conventional immersion nozzles critical problems, such as unstable bulk mould flow have been noticed. LÄS MER