Sökning: "size selection"

Visar resultat 1 - 5 av 435 avhandlingar innehållade orden size selection.

1. 1. Selection on floral traits in Primula farinosa

   Författare :Didrik Vanhoenacker; Johan Ehrlén; Jon Ågren; Arjen Biere; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coevolution; correlational selection; Falseuncaria ruficiliana; geographic mosaic; hand pollination; Hermann Müller; interaction strength; plant-insect interactions; pollen limitation; selection strength; spatiotempora; Uta stansburiana; Biology; Biologi; Plant Ecology; växtekologi;

   Sammanfattning : Flowers and inflorescences have evolved in relation to animals for at least 100 million years. Plants attract pollinators with large, conspicuous, bright-coloured or scented flowers. These display attributes, however, also attract herbivores. LÄS MER

3. 2. Evolutionary consequences of sex-specific selection

   Författare :Josefine Stångberg; Elisabeth Bolund; Elina Immonen; Jennifer Perry; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Caenorhabditis remanei; Callosobruchus maculatus; sex-specific selection; sexual selection; experimental evolution; intralocus sexual conflict; life history evolution; sexual dimorphism; trade-offs; Quantitative genetics;

   Sammanfattning : Sex-specific selection is widespread, evident by the evolution of sexual dimorphism in many traits in sexually reproducing taxa. The reason why the sexes may experience selection that differs in direction or magnitude is often linked to the reproductive strategies associated with the sex-specific reproductive physiology. LÄS MER

4. 3. Why and how brain size evolves : Sociality, predation and allometry

   Författare :Wouter van der Bijl; Niclas Kolm; Joah Madden; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; brain size; brain size evolution; encephalization; predation; predator inspection; sociality; animal contest; constraint; etologi; Ethology;

   Sammanfattning : The evolution of the vertebrate brain has remained a topic of intense interest from biologists over many decades. Evolutionary biologists have seen it as an intriguing example of how the size and structure of a trait evolves across large phylogenies and under body size constraints, with both large shifts in deep evolutionary time and continuous smaller scale adaptation. LÄS MER

5. 4. Criterion-referenced measurement for educational evaluation and selection

   Författare :Christina Wikström; Widar Henriksson; Roger Murphy; Umeå universitet; []
   Nyckelord :Assessment; Competition; Criterion-referenced; Education; Evaluation; Grading; Grade inflation; Measurement; Selection; Validity; Beteendevetenskapliga mätningar; pedagogik; Education;

   Sammanfattning : In recent years, Sweden has adopted a criterion-referenced grading system, where the grade outcome is used for several purposes, but foremost for educational evaluation on student- and school levels as well as for selection to higher education. This thesis investigates the consequences of using criterion-referenced measurement for both educational evaluation and selection purposes. LÄS MER

7. 5. Methods to Generate Size- and Composition Controlled Aerosol Nanoparticles

   Författare :Martin Karlsson; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; differential mobility analyzer DMA ; transfer function; binary alloy nanoparticles; nanoparticle generator; thermal decomposition; Physics; sintering; Fysik; size selection; nanoparticles; aerosol technology; Fysicumarkivet A:2004:Karlsson;

   Sammanfattning : This thesis describes experiments performed using different methods to produce aerosol nanoparticles with control over size and composition. The process included differential mobility analyzers (DMAs) as size-selecting instruments and tube furnaces for particle synthesis. LÄS MER