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Visar resultat 6 - 10 av 38 avhandlingar som matchar ovanstående sökkriterier.

  1. 6. Species Delimitation and Phylogenetic Relationships. A study of Silene sections Atocion and Cryptoneurae

    Författare :Zeynep Aydin; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Caryophyllaceae; Silene; Section Atocion; S. ertekinii; S. cryptoneura; S. aegyptiaca; SystematicsPhylogenetics; Species delimitation; Multispecies coalescent; Marginal likelihood; Species tree; DISSECT.;

    Sammanfattning : Abstract The existence of conflicting genealogies of different genes through the evolution of species complicates the inference of phylogenetic relationships. The Multispecies Coalescent (MSC) model provides a theoretical background that account for the stochasticity in the genealogical process, thus providing systematists with a potentially objective way of testing alternative hypotheses of putative species. LÄS MER

  3. 7. Equity in welfare evaluations : the rationale for and effects of distributional weighting

    Författare :Gunnel Bångman; Lars Hultkrantz; Fredrik Carlsson; Örebro universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; weighted cost-benefit analysis; equity; distributional weights; social welfare; income distribution; risk aversion; social marginal value of income; altruism; paternalism; marginal utility of income; social inequality aversion; stated preferences; Economics; Nationalekonomi; Economics; Nationalekonomi;

    Sammanfattning : This thesis addresses the issue of weighted cost-benefit analysis (WCBA). WCBA is a welfare evaluation model where income distribution effects are valued by distributional weighting. The method was developed already in the 1970s. The interest in and applications of this method have increased in the past decade, e. LÄS MER

  4. 8. On the evolutionary effects of linkage and deleterious mutations in small populations

    Författare :Snæbjörn Pálsson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Breeding systems; Daphnia pulex; deleterious mutations; linkage; neutral variation; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; Genetics; genetik;

    Sammanfattning : The aim of this thesis is to evaluate the effect of deleterious mutations and linkage on variation in neutral markers and fitness in small populations. The study is based on two main approaches, one by using computer simulations, the other by exploring genetic variation in a cyclical parthenogen, Daphnia pulex (Crustacea: Cladocera). LÄS MER

  5. 9. Radiographic follow-up analysis of Br?nemark? dental implants

    Författare :Solweig Sundén Pikner; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cluster effect; Dental implants; Dependency; Diagnostic accuracy; Long-term follow-up; Marginal bone level; Observer variation; Osseointegration; Prediction;

    Sammanfattning : Radiography plays an important role in clinical routine practice and in research projects evaluating dental implants, among them Br?nemark? System. Presence of a peri-implant radiolucency has been used in studies as a criterion for implant failure without knowledge of its diagnostic accuracy. LÄS MER

  7. 10. Reproductive patterns of birches (Betula spp.) in northern Sweden

    Författare :Stig-Olov Holm; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Reproduction; Betula; seed-quality; seed-set; pollination; pollen-limitation; pollen-competition; tree-line; environmental gradient; seed weight; seedling survival; Semudobia;

    Sammanfattning : The aim of this thesis was to study patterns of reproduction of Betula pendula and B. pubescens coll. along an altitudinal, coastal-inland, gradient in northern Sweden. The altitudinal variation was related to the distribution of the birch taxa along the gradient. LÄS MER