Sökning: "pollen analysis"

Visar resultat 21 - 25 av 63 avhandlingar innehållade orden pollen analysis.

  1. 21. Population differentiation in Lythrum salicaria along a latitudinal gradient

    Författare :Katarina Olsson; Jon Ågren; Susan Kalisz; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; additive genetic variance; clinal variation; evolutionary constraints; G matrix; genetic correlation; natural selection; pollen limitation; population differentiation; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : In this thesis, quantitative genetic approaches, common-garden experiments, and field studies were combined to examine patterns of population differentiation and the genetic architecture of characters of putative adaptive significance in the widely distributed perennial herb Lythrum salicaria. In this work, I (1) documented patterns of population differentiation in phenology, life-history, and morphology along latitudinal gradients at different geographical scales, (2) investigated the genetic architecture of phenology, flower morphology, and inflorescence size, and (3) combined estimates of phenotypic selection in the field with information on the genetic variance-covariance matrix (G) to examine potential constraints to adaptive evolution. LÄS MER

  2. 22. Fire history in the hemiboreal and southern boreal zones of southern Sweden during 11000 years : Relationships with past vegetation composition and human activities and implications for biodiversity issues

    Författare :Qiao-Yu Cui; Marie-José Gaillard; Boris Vannière; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fire history; land-use history; biodiversity; charcoal analysis; Landscape Reconstruction Algorithm LRA ; Holocene; Småland; Sweden; Paleoecology; Paleoekologi;

    Sammanfattning : This thesis studies fire history over the last 11 000 years (Holocene) in central Småland, southern Sweden, on the basis of palaeoecological analyses of peat sequences from three small bogs (Notteryd, Stavsåkra and Storasjö). The main objective is to gain insights into the long-term relationships between fire, climate, human-impact, other environmental factors and the history of biodiversity in the study region. LÄS MER

  3. 23. Bioinformatic identification of disease associated pathways by network based analysis

    Författare :Fredrik Barrenäs; Mikael Benson; Michael Langston; Jan Komorowski; Linköpings universitet; []
    Nyckelord :;

    Sammanfattning : Many common diseases are complex, meaning that they are caused by many interacting genes. This makes them difficult to study; to determine disease mechanisms, disease-associated genes must be analyzed in combination. LÄS MER

  4. 24. Effects of landscape context on populations of bumblebees

    Författare :Anna Persson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Apoidea; Bombus; Campanula; agriculture; land-use intensity; complexity; garden; grassland; field border; MFC; pollination; Factor Analysis;

    Sammanfattning : To investigate recent declines in bumblebee populations, I carried out landscape analyses, made field studies of bumblebees, flowering plants and pollination in an agricultural region in southernmost Sweden. Studies were carried out in landscapes of contrasting agricultural intensity and land-cover configuration; "simple" landscapes highly dominated by large crop fields, and "complex" with mixed farming, grasslands and smaller fields. LÄS MER

  5. 25. Human IgE - What We Can Learn from Repertoire Studies and How We Can Use Them as Tools

    Författare :Mattias Levin; Institutionen för immunteknologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Allergy; antibodies; IgE; transcriptome analysis; immunotherapy; molecular biology;

    Sammanfattning : Antibodies of the IgE isotype play a key role as the allergen recognizer in allergic disease, which today affects as much as a third of the population in the industrialized parts of the world. Despite this crucial role of IgE, our knowledge of IgE repertoires and how we can utilize the information hidden in monoclonal IgE to improve the quality of life of allergic patients, is limited. LÄS MER