Sökning: "Johan Olofsson"

Visar resultat 16 - 20 av 22 avhandlingar innehållade orden Johan Olofsson.

  1. 16. The role of herbivores in mediating responses of tundra ecosystems to climate change

    Författare :Elina Kaarlejärvi; Johan Olofsson; Anu Eskelinen; Jon Moen; Eric Post; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Climate change; warming; grazer; Rangifer; Lemmus lemmus; species distribution; biotic interactions; altitude; Environmental Science; miljövetenskap;

    Sammanfattning : The Arctic areas are warming more rapidly than other parts of the world. Increasing temperatures are predicted to result in shrubification, higher productivity, declining species diversity and new species invasions to the tundra. LÄS MER

  3. 17. Circumpolar impacts of herbivores on Arctic tundra vegetation

    Författare :Elin Lindén; Johan Olofsson; Maja K. Sundqvist; Mariska te Beest; Elisabeth S. Bakker; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; herbivores; grazing; Arctic; circumpolar; tundra; vegetation; plant defence; secondary metabolites; shrub birch; exclosures; vegetation; species diversity; biology; biologi;

    Sammanfattning : Arctic tundra vegetation provides many ecological services that have implications for the global climate. However, the tundra biome is currently changing in response to increasing temperatures. Herbivores may mitigate some of these responses to warming through their impact on Arctic vegetation. LÄS MER

  4. 18. Resistance to neuraminidase inhibitors in influenza A virus isolated from mallards

    Författare :Goran Orozovic; Björn Olsen; Johan Lennerstrand; Sigvard Olofsson; Linnéuniversitetet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; influenza; mallards; neuraminidase; PCR; sequencing; mutation; oseltamivir; zanamivir; resistance; NAI; antivirals; pandemic; Virology; Virologi; Molecular biology; Molekylärbiologi; Bioinformatics; Bioinformatik; Zoonotisk ekologi; Zoonotic Ecology; Virology; Virologi; Biokemi; Biochemistry;

    Sammanfattning : Influenza A virus belongs to the Orothomyxoviridae family of viruses and is one of the most common pathogens that cause infections of the respiratory tract. The aim of this thesis was to investigate if neuraminidase inhibitor (NAI) Tamiflu® (oseltamivir, OC) and Relenza® (zanamivir, ZA) - related resistance mutations exist in the neuraminidase (NA) gene of viruses collected from wild birds. LÄS MER

  5. 19. The Effect of Snow on Plants and Their Interactions with Herbivores

    Författare :Mikaela Torp; Johan Olofsson; Christa Mulder; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Snow; arctic ecosystem; plant-herbivore interactions; phenology; nitrogen; phenolics; experimental manipulation; natural gradient; inter-annual variability; Biology; Biologi;

    Sammanfattning : The ongoing climate changes are predicted to accelerate fast in arctic regions with increases in both temperatures and precipitation. Although the duration of snow cover is generally expected to decrease in the future, snow depth may paradoxically increase in those areas where a large amount of the elevated precipitation will fall as snow. LÄS MER

  7. 20. Adjuvant treatments to prevent local reurrence after breast-conserving surgery for early breast cancer : radiation, endocrine- or brachytherapy

    Författare :Åsa Wickberg; Göran Liljegren; Johan Ahlgren; Roger Olofsson Bagge; Örebro universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Breast-conserving surgery; radiotherapy; endocrine therapy; intraoperative brachytherapy;

    Sammanfattning : Radiotherapy after breast-conserving surgery due to breast cancer is an established treatment, known to reduce the incidence of recurrence and even death from the disease. However some women are over-treated with sometimes serious adverse effects. De-escalating the treatment and find alternative adjuvant methods are becoming an important issue. LÄS MER