Sökning: "long-term selection"

Visar resultat 1 - 5 av 266 avhandlingar innehållade orden long-term selection.

  1. 1. Long-term studies of succession : Colonisation and seed banks

    Författare :Ulf Grandin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Ellenberg indicator values; genetic variation; long-term study; Lythrum salicaria; Moehringia trinervia; primary succession; seed bank; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : Using data from long-term studies of the vegetation in two areas under primary succession, patterns of colonisation and the accumulated seed bank during plant succession were studied.At century-old small islands in Lake Hjälmaren, Sweden, the genetic structure of differently old populations of Moehringia trinervia and Lythrum salicaria was studied, using allozyme variation for M. LÄS MER

  3. 2. Life History of the Common Gull (Larus canus) : A Long-Term Individual-Based Study

    Författare :Kalev Rattiste; Mats Björklund; Jon E Brommer; Jan-Åke Nilsson; Uppsala universitet; []
    Nyckelord :Ecology; longitudinal studies; reproductive success; survival; pair bond; indicator trait; breeding time; heritability; selection; Ekologi; Larus canus; ekologisk botanik; Ecological Botany;

    Sammanfattning : An individual’s life history is a sequence of events which eventually determine its contribution to the next generation, or fitness. These events are affected by environmental factors, genetic make-up and decisions made by an individual and its breeding partner. LÄS MER

  4. 3. Uvulopalatopharyngoplasty : patient selection, long- term outcomes, and side effects

    Författare :Joar Sundman; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Uvulopalatopharyngoplasty (UPPP) is the most common surgical treatment for adult patients with obstructive sleep apnea (OSA). Its short-term efficacy, as measured through polysomnography, is well-established and has been demonstrated in two randomized controlled trials in recent years. LÄS MER

  5. 4. Developmental plasticity of the glutamate synapse: Roles of low frequency stimulation, hebbian induction and the NMDA receptor

    Författare :Joakim Strandberg; Göteborgs universitet; []
    Nyckelord :AMPA receptor; Development; Glutamate; Hippocampus; Long-term depression; Long-term potentiation; NMDA receptor; Synaptic depression;

    Sammanfattning : The glutamate synapse is by far the most common synapse in the brain and acts via postsynaptic AMPA, NMDA and mGlu receptors. During brain development there is a continuous production of these synapses where those partaking in activity resulting in neuronal activity are subsequently selected to establish an appropriate functional pattern of synaptic connectivity while those that do not are elimimated. LÄS MER

  7. 5. Measuring long-term effects of a school improvement initiative

    Författare :Joakim Svärdh; Inga-Britt Skogh; Erik Mellander; Veronica Bjurulf; Monica Rosén; KTH; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Propensity Score Analysis PSA ; effect study; quantitative evaluation; educational intervention; compulsory school; Science and Technology for All Initiative; representative sample; non-random selection; multi-level modelling; post-matching multivariate regression;

    Sammanfattning : There is a growing demand for studies applying quantitative methods to large-scale data sets for the purpose of evaluating the effects of educational reforms (UVK, 2010). In this thesis the statistical method, Propensity Score Analysis (PSA), is presented and explored in the evaluating context of an extensive educational initiative within science and technology education; the Science and Technology for All-program (NTA). LÄS MER