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Visar resultat 1 - 5 av 143 avhandlingar som matchar ovanstående sökkriterier.

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. 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

5. 4. Static and fatigue analyses of welded steel structures : some aspects towards lightweight design

   Författare :Mansoor Khurshid; Zuheir Barsoum; Lars-Erik Lindgren; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue strength; welded joints; static strength; high strength steel; Farkostteknik; Vehicle and Maritime Engineering; Aerospace Engineering; Flyg- och rymdteknik;

   Sammanfattning : The objectives of this thesis comprise of overcoming the challenges in designing lightweight welded structures such as material selection, choice of fatigue design methods, and increased performance by using improvement techniques. Material selection of welded joints is dependent on the filler and base material strengths. LÄS MER

7. 5. Sexual Selection and Adaptation to Novel Environments

   Författare :Ivain Martinossi-Allibert; David Berger; Göran Arnqvist; Lukas Schärer; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sexual selection; Environmental change; Sexual conflict; Environmental stress; Adaptation; Adaptive landscape; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology;

   Sammanfattning : The work included in this thesis aims at exploring the environmental sensitivity of benefits and costs of sexual selection through a combined empirical and theoretical effort, to increase our understanding of the impact of environmental change on sexually reproducing populations.Can sexual selection promote adaptation to novel environments? Sexual selection for good genes should accelerate adaptation by granting higher reproductive success to individuals of high genetic quality. LÄS MER