Sökning: "Jan Byström"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden Jan Byström.

  1. 1. Alla "studiecirklar" blir inte studiecirklar. En diskussion om studiecirklars utveckling med särskilt avseende på cirkelledarens situation och funktion

    Författare :Jan Byström; Stockholms universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES;

    Sammanfattning : .... LÄS MER

  3. 2. Effects of temperature and terrestrial carbon on primary production in lake ecosystems

    Författare :Mohammed Hamdan; Jan Karlsson; Pär Byström; Erin R. Hotchkiss; Lars-Anders Hansson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lakes; primary production; benthic; pelagic; carbon dioxide limitation; light limitation; nutrient limitation; browning; warming; allochthonous carbon; grazing; trophic cascades;

    Sammanfattning : Climate warming is predicted to affect northern lake food webs in two ways: (1)directly via changes in water temperature and ice conditions, and (2) indirectlyvia changes in catchment characteristics and processes that influence input ofallochthonous coloured dissolved organic matter (cDOM) and nutrients. Input ofcDOM increases carbon dioxide (CO2) availability, causes brownification andreduced light conditions, and may increase nutrient availability especially forpelagic primary producers. LÄS MER

  4. 3. Climate change impacts on production and dynamics of fish populations

    Författare :Per Hedström; Pär Byström; Jan Karlsson; Peter Eklöv; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Temperature; terrestrial dissolved organic carbon; light extinction; GPP; recruitment; winter mortality; metabolism; cohort competition; fish production; fish biomass;

    Sammanfattning : Ongoing climate change is predicted to increase water temperatures and export of terrestrial dissolved matter (TDOM) to aquatic ecosystems influencing ecosystem productivity, food web dynamics and production of top consumers. Ecosystem productivity is mainly determined by the rates of primary production (GPP) in turn controlled by nutrients, light availability and temperature, while temperature alone affect vital rates like consumption and metabolic rates and maintenance requirements of consumers. LÄS MER

  5. 4. Jack of all trades, master of none : the multifaceted nature of H3K36 methylation

    Författare :Henrik Lindehell; Jan Larsson; Anders Byström; Peter B. Becker; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; H3K36; histone methylation; dosage compensation; chromosome-specific gene regulation; transposable elements; PIWI piRNA biosynthesis; Set2; Ash1; NSD; Histone 3.3; post-translational modifications; histone modifications; epigenetics; proximity ligation assay; Drosophila; Genetics; genetik; molekylärbiologi; Molecular Biology; Biopharmaceutics; biofarmaci;

    Sammanfattning : Post-translational modifications of histones enable differential transcriptional control of the genome between cell types and developmental stages, and in response to environmental factors. The methylation of Histone 3 Lysine 36 (H3K36) is one the most complex and well-studied histone modifications and is known to be involved in a wide range of molecular processes. LÄS MER

  7. 5. Lake bathymetry as driver of salmonid population size structure and biomass

    Författare :Sven Norman; Pär Byström; Karin A. Nilsson; Jan Karlsson; Per-Arne Amundsen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lake bathymetry; habitat-specific resource production; ontogenetic niche shifts; size structure; Arctic char; brown trout; populationsbiologi; Population Biology; Limnology; limnologi; zooekologi; Animal Ecology;

    Sammanfattning : Most fish species undergo ontogenetic niche shifts from feeding on pelagic zooplankton, to larger benthic invertebrates and in some cases also to fish. These ontogenetic niche shifts have strong impact on the interactions within and between species, with effects on individual growth, population abundance and food web dynamics. LÄS MER