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Visar resultat 1 - 5 av 9 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Studies of Nuclear Fuel by Means of Nuclear Spectroscopic Methods

    Författare :Peter Jansson; Roland Carchon; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiation sciences; irradiated nuclear fuel; nuclear spectroscopy; tomography; safeguard; Strålningsvetenskap; Radiation biology; Strålningsbiologi; Kärnfysik; Nuclear Physics;

    Sammanfattning : The increasing demand for characterization of nuclear fuel, both from an operator and authority point of view, motivates the development of new experimental and, preferable, non-destructive methods. In this thesis, some methods based on nuclear spectroscopic techniques are presented. LÄS MER

  3. 2. The hidden life of plants : fine root dynamics in northern ecosystems

    Författare :Gesche Blume-Werry; Roland Jansson; Ann Milbau; Scott D. Wilson; Isla Myers-Smith; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic; belowground; boreal; climate change; fine roots; heath; meadow; minirhizotron; permafrost; phenology; plant community; root biomass; root growth; root litter; root production; subarctic; tundra;

    Sammanfattning : Fine roots constitute a large part of the primary production in northern (arctic and boreal) ecosystems, and are key players in ecosystem fluxes of water, nutrients and carbon. Data on root dynamics are generally rare, especially so in northern ecosystems. LÄS MER

  4. 3. Ice, wood and rocks : regulating elements in riverine ecosystems

    Författare :Johanna Engström; Christer Nilsson; Roland Jansson; James Helfield; Tenna Riis; Umeå universitet; []
    Nyckelord :riparian zone; timber floating; river restoration; cut-off side channels; hydrochory; large wood; anchor ice; fish;

    Sammanfattning : Riparian ecosystems are of great importance in the landscape, connecting landscape elements longitudinally and laterally and often encompassing sharp environmental gradients in ecological processes and communities. They are influenced by fluvial disturbances such as flooding, erosion and sediment deposition, which create dynamic and spatially heterogeneous habitats that support a high diversity of species. LÄS MER

  5. 4. Ecosystem functioning in streams : Disentangling the roles of biodiversity, stoichiometry, and anthropogenic drivers

    Författare :André Frainer; Roland Jansson; Brendan McKie; Jonathan Benstead; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; detrital food web; functional diversity; stoichiometry; nitrogen and phosphorus concentrations; recalcitrant carbon; spatial and temporal species distribution; pools and riffles; isotopes; leaf decomposition rates; land use; restoration; habitat complexity;

    Sammanfattning : What will happen to ecosystems if species continue to go extinct at the high rates seen today? Although ecosystems are often threatened by a myriad of physical or chemical stressors, recent evidence has suggested that the loss of species may have impacts on the functions and services of ecosystems that equal or exceed other major environmental disturbances. The underlying causes that link species diversity to ecosystem functioning include species niche complementarity, facilitative interactions, or selection effects, which cause process rates to be enhanced in more diverse communities. LÄS MER

  7. 5. Predictive Markers of Treatment Resistance in Head and Neck Squamous Cell Carcinoma

    Författare :Fredrik Jerhammar; Karin Roberg; Roland Grafström; Agneta Jansson; Keith D. Hunter; Linköpings universitet; []
    Nyckelord :;

    Sammanfattning : Head and neck cancer is a common malignancy with approximately 600 000 new cases yearly. Disappointingly, the overall survival has not increased over the last decades. The concept of personalized medicine, i.e. LÄS MER