Sökning: "speciation analysis"

Visar resultat 6 - 10 av 73 avhandlingar innehållade orden speciation analysis.

  1. 6. Biodiversity in Swedish Cyprinid Fish: Insights Into Processes of Divergence

    Författare :Marnie H Demandt; Mats Björklund; Erik Petersson; Brent Emerson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; speciation; hybridization; bottleneck; genetic drift; phylogeny; speciation rates; common bream; white bream; roach; Swedish cyprinid fish; Cyprinidae; Biology; Biologi;

    Sammanfattning : Uncovering and understanding the processes that have led to the biological diversity we observe today are of fundamental interest in biology. Since direct observation of speciation is usually impossible, knowledge about the processes behind species formation can be gathered by studying mutations, natural/sexual selection, and genetic drift. LÄS MER

  3. 7. Genetic Adaptation and Speciation in Darwin’s Finches and Atlantic Herring

    Författare :Fan Han; Leif Andersson; Kjetill Sigurd Jakobsen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Darwin s finches; Atlantic herring; Population genetics; Evolution; Ecological adaptation; Speciation; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology; Bioinformatics; Bioinformatik;

    Sammanfattning : Natural selection acts on existing genetic variation to drive genetic adaptation of organisms to various ecological niches. Interaction between closely related populations, through processes such as competition and hybridization, may either lead to their divergence or population fusion, which has consequences for adaptation and the formation of species. LÄS MER

  4. 8. Hybrid zones and speciation – insights from the European crow hybrid zone

    Författare :Fredrik Haas; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; microsatellites; mc1r; introgression; hybrid zone; speciation; European crow; Corvus corone; habitat preferences; neural network; sexual imprinting; assortative mating;

    Sammanfattning : In hybrid zones genetically differentiated populations meet and interbreed. As they result from ongoing divergence and potential speciation, such zones provide opportunities to study how different factors affect this process. The hybrid zone between the all black carrion crow (Corvus corone corone) and the grey and black hooded crow (Corvus c. LÄS MER

  5. 9. Speciation analysis of butyl- and phenyltin compounds in environmental samples by GC separation and atomic spectrometric detection

    Författare :Dong Nguyen Van; Wolfgang Frech; Anders Cedergren; Erwin Rosenberg; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organotin speciation analysis; species-specific isotope dilution; inductively coupled plasma mass spectrometry; single isotope spike; multi-isotope spike; redistribution; species transformation; preparative liquid chromatography; gas chromatography; line source atomic absorption spectrometry; continuum source atomic absorption spectrometry; Analytical chemistry; Analytisk kemi;

    Sammanfattning : The main goal of the work presented in this thesis is to improve the reliability of existing methods for speciation analysis of organotin compounds Species-specific isotope dilution (SSID) calibration in combination with gas chromatography – inductively coupled plasma mass spectrometry was used to investigate the transformation of phenyltin species during sample preparation. Isotope-enriched phenyltin species were synthesized from corresponding isotope-enriched tin metals. LÄS MER

  7. 10. Cadmium Distribution and Speciation by Synchrotron Radiation Induced X-Ray Microprobe Techniques Application to Municipal Solid Waste and Biomass Fly Ashes

    Författare :Caterina Camerani Pinzani; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; leaching; speciation; MSW; biomass; affinity; synchrotron radiation based micro-probe techniques; Ca-containing matrices; cadmium; fly ashes;

    Sammanfattning : During the last few years, alternative fuels, such as wood and Municipal Solid Waste (MSW), are increasingly being used in Sweden for heat and power production. The positive environmental impact in terms of low sulphur emissions, no net emission of CO2 to the atmosphere, and local availability are main driving forces in this development. LÄS MER