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Visar resultat 1 - 5 av 12 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. The diapause switch : Evolution of alternative developmental pathways in a butterfly

    Författare :Inger Marie Aalberg Haugen; Karl Gotthard; Dan Hahn; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental plasticity; phenotypic plasticity; developmental switch; threshold trait; life-cycle regulation; direct development; Lepidoptera; zoologisk ekologi; Animal Ecology;

    Sammanfattning : Diapause decision is a classic example of a threshold switch mechanism with cascading effects on morphology, behaviour and life-history traits. This thesis addresses the downstream effects of the insect diapause switch, with the main focus on pathway-specific regulation of life-history traits, using the speckled wood butterfly (Pararge aegeria) as a study species. LÄS MER

  3. 2. On the threshold of adulthood : Recurrent phenomena and developmental tasks during the period of young adulthood

    Författare :Gunnel Jacobsson; Siv Boalt Boëthius; Andrzej Werbart; Harriet Bjerrum Nielsen; Stockholms universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Young adults; Strains in life; Gender; Developmental tasks; Depression; Daydreaming; Narrative; Psychoanalytic theory; Education; Pedagogik;

    Sammanfattning : The aim of the dissertation is to investigate the own narratives told by young adults in the age group 18 to 25 years old about strains in life, ideas about the background to these, and attitudes now and in an imagined future. The emerging recurrent phenomena form the basis for a deeper understanding of the developmental tasks of young adults. LÄS MER

  4. 3. Phenotypic plasticity and local adaptation in island populations of Rana temporaria

    Författare :Martin Lind; Frank Johansson; Juha Merilä; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Costs of plasticity; Developmental threshold; FST; Local adaptation; Phenotypic plasticity; Pool drying; QST; Freshwater ecology; Limnisk ekologi; zooekologi; Animal Ecology;

    Sammanfattning : Phenotypic plasticity is the ability of a genotype to express different phenotypes in different environments. Despite its common occurrence, few have investigated differences in plasticity between populations, the selection pressures responsible for it, and costs and constraints associated with it. LÄS MER

  5. 4. Motor control in zebrafish : excitatory drive and developmental changes

    Författare :Sabine Görgens; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : An essential characteristic of human and animal life is the ability to move from one place to another, in order to survive in a complex environment. All the different forms of locomotion, like walking, swimming, crawling and flying, have one common feature: rhythmic and alternating movements of the body. LÄS MER

  7. 5. Bilingual education cognitive development and school achievement : a study of the bilingual programs for Tibetan children

    Författare :Yu Qiang; Katrin Goldstein Kyaga; Stockholms universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; bilingualism; bilingual education; cognitive development; threshold hypothesis; study variable; covariates the third variables ; path analysis; direct effects; total effects.; internationell pedagogik; International Education;

    Sammanfattning : This study examines the effects of two models of school bilingual programs on Tibetan children's cognitive development and school achievement.Based on the findings of empirical studies, Cummins' threshold theory was critically evaluated. LÄS MER