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Visar resultat 1 - 5 av 248 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Dating Divergence Times in Phylogenies

    Författare :Cajsa Lisa Anderson; Kåre Bremer; Katleen M. Pryer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; systematic biology; divergence time; nonprametric rate smoothing; Bayesian; multidivtime; eudicots; Neoaves; monocots; dating; molecular clock; relaxed clock; age constraint; fossil; calibration; PATHd8; penalized likelihood; Biology; Biologi;

    Sammanfattning : This thesis concerns different aspects of dating divergence times in phylogenetic trees, using molecular data and multiple fossil age constraints.Datings of phylogenetically basal eudicots, monocots and modern birds (Neoaves) are presented. Large phylograms and multiple fossil constraints were used in all these studies. LÄS MER

  3. 2. Organising Intimacy : Exploring Heterosexual Singledoms at Swedish Singles Activities

    Författare :Andreas Henriksson; Gerd Lindgren; Åsa Wettergren; Annika Jonsson; Sasha Roseneil; Karlstads universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; singledom; heterosexuality; intimacy; Carol Smart; personal life; multi-sited ethnography; community; courtship; dating; internet dating; sociology of family; relationality; close relations; liminal space; singelskap; heterosexualitet; intimitet; Carol Smart; personligt liv; multi-sited ethnography; gemenskap; kurtis; dejting; internetdejting; familjesociologi; relationalitet; nära relationer; liminalt rum; Sociologi; Sociology;

    Sammanfattning : Single activities have long been places where single people can come to meet friends, build community or look for partners. The activities have relevance for studies of heterosexuality, intimacy, personal life and space. LÄS MER

  4. 3. Dealing With Reservoir Effects in Human and Faunal Skeletal Remains : Understanding the radiocarbon dating of aquatic samples

    Författare :Jack Dury; Gunilla Eriksson; Kerstin Lidén; Peter Jordan; Johannes van der Plicht; Philippa Ascough; Stockholms universitet; []
    Nyckelord :HUMANIORA; HUMANITIES; Radiocarbon Dating; Reservoir Effects; Bayesian; Modelling; Palaeodiet; Stable Isotopes; Skeletal Remains; Collagen; arkeologi med inriktning mot laborativ arkeologi; Scientific Archaeology;

    Sammanfattning : Archaeology relies on the ordering of past events to study cultural developments. This has traditionally been achieved by looking at the stratigraphic depths of materials relative to one another. In this way, chronologies of past technological progressions and stylistic changes can be built. LÄS MER

  5. 4. Comparison of dating methods for paleoglacial reconstruction in Central Asia

    Författare :Natacha Gribenski; Krister N. Jansson; Arjen P. Stroeven; Frank Preusser; Jonathan M. Harbor; Marc Bateman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Paleoglaciation; Optically stimulated luminescence dating; Cosmogenic nuclide exposure dating; EMCCD camera; Physical Geography; naturgeografi;

    Sammanfattning : Reconstruction of former Central Asian glaciers extents can provide valuable information about past atmospheric circulation variations. These extents, often marked by terminal moraines, need to be chronologically constrained. Cosmogenic nuclide exposure (CNE) dating is widely used to directly date moraines. LÄS MER

  7. 5. Re-Os dating of molybdenite : new anlytical approaches using ICP-MS

    Författare :Dmitry Malinovskiy; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

    Sammanfattning : In recent years, there has been a surge of interest in the direct dating of ore deposits using Re-Os geochronometer for the ore minerals themselves. Molybdenite has been or particular interest because it is a common ore mineral and is suitable for analysis by the Re-Os method due to relatively high concentration of both Re and Os. LÄS MER