Sökning: "multiple origins"

Visar resultat 1 - 5 av 60 avhandlingar innehållade orden multiple origins.

  1. 1. Multiple Time Scales and Longitudinal Measurements in Event History Analysis

    Författare :Danardono; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Statistics; Cox regression; multiple events; proportiona hazards; random effects; survival analysis; time-dependent covariates; time origin; Statistik; Statistics; Statistik; Statistics; statistik;

    Sammanfattning : A general time-to-event data analysis known as event history analysis is considered. The focus is on the analysis of time-to-event data using Cox's regression model when the time to the event may be measured from different origins giving several observable time scales and when longitudinal measurements are involved. LÄS MER

  3. 2. Evolution of Flowering Time in the Tetraploid Capsella bursa-pastoris (Brassicaceae)

    Författare :Tanja Slotte; Martin Lascoux; Ulf Lagercrantz; Juliette de Meaux; Uppsala universitet; []
    Nyckelord :Biology; flowering time; homoeolog; hybridization; introgression; microarray; multiple origins; polyploid; QTL; Biologi;

    Sammanfattning : Although polyploidy is believed to be a major source of evolutionary novelty, few studies have examined the genetic basis of phenotypic variation in wild polyploids. In this thesis I have studied the genetic basis of flowering time variation in the wild tetraploid crucifer Capsella bursa-pastoris, as well as the evolutionary history of this species. LÄS MER

  4. 3. The origins and consequences of attention deficit hyperactivity disorder

    Författare :Zheng Chang; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Attention deficit hyperactivity disorder (ADHD) is characterized by developmentally inappropriate levels of inattention, hyperactivity, and impulsivity, and is the most common neurodevelopmental disorder of childhood. This highly prevalent disorder is estimated to affect about 5% of school-age children worldwide, with a substantial degree of persistence over time. LÄS MER

  5. 4. Systematics, phylogeography and multiple origins of morphs in two species complexes belonging to Cistaceae, Helianthemum oelandicum and H. nummularium

    Författare :Eman Soubani; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; introgression; parallel evolution; postglacial migration; genetic polymorphism; Pleistocene; morphometry; H. nummularium; Helianthemum oelandicum; cpDNA;

    Sammanfattning : The Helianthemum oelandicum complex shows considerable morphological variation across its geographic distribution in Europe and western Asia. By combining four primer pairs and four restriction enzymes I identified nine cpDNA haplotypes with distinct geographical distributions. LÄS MER

  7. 5. Cancer of unknown primary: searching for the etiological clues. A population-based epidemiological study in Sweden

    Författare :Xiaochen Shu; Allmänmedicin och klinisk epidemiologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cancer of unknown primary; causes of death; familial risk; immigrant; incidence; multiple malignancies; risk factor; squamous cell carcinoma; standardizedincidence ratio; survival;

    Sammanfattning : This thesis aimed to search for etiological clues about cancer of unknown primary(CUP) by gathering novel information. The Swedish national registries were used and CUP cases were identified according to the seventh revision of the International Classification of Diseases. LÄS MER