Search for dissertations about: "Arkiv X"

Found 4 swedish dissertations containing the words Arkiv X.

  2. 1. Mid-Holocene mineral dust deposition in raised bogs in southern Sweden : Processes and links

    Author : Jenny Sjöström; Malin Kylander; Carl-Magnus Mörth; Bindler Richard; Lisa Belyea; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Paleodust; peat; geochemistry; mineralogy; REE; Holocene; peat accumulation rates; paleostorms; Marine Geology; maringeologi;

    Abstract : Atmospheric mineral dust is a key component of the climate system, which affects insolation, brings nutrients to marine and terrestrial ecosystems, and acts as a cloud condensation nuclei. To reconstruct past patterns in terrestrial dust deposition natural archives may be utilized, such as loess, dunes, lakes, and peat bogs. READ MORE

  4. 2. The palaeolimnological record of regime shifts in lakes in response to climate change

    Author : Linda Randsalu Wendrup; Kvartärgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; palaeolimnology; regime shifts; thresholds; alternative stable states; climate change; ecosystem dynamics; diatoms; hydrocarbons; monitoring; lake sediments; shallow lakes; 8.2 ka event;

    Abstract : Regime shifts in lake ecosystems can occur in response to both abrupt and continuous climate change, and the imprints they leave in palaeolimnological records allow us to investigate and better understand patterns and processes governing ecological changes on geological time scales. This thesis aims at investigating palaeolimnological records of regime shifts in lakes during the Holocene to explore how lake ecosystems responded to climate changes and anthropogenic activities and to identify thresholds or tipping points that produced regime shifts. READ MORE

  5. 3. Crystallographic studies on porphyrin metallation by ferrochelatase

    Author : David Lecerof; Biokemi och Strukturbiologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; thermal and mechanical properties; Condensed matter:stucture; fasjämvikt; kristallografi; egenskaper termiska och mekaniska ; Kondenserade materiens egenskaper:struktur; crystallography; phase equilibria; Magnesium; pi-helix; Zinc; ferrochelatase; Metal binding; porphyrin metallation;

    Abstract : Ferrochelatase catalyses the terminal step in heme biosynthesis by inserting a ferrous ion into protoporphyrin IX. The reaction mechanism has in this thesis been studied by mainly crystallographic methods. READ MORE

  6. 4. The impact of past land-use change on floristic diversity in southern Sweden : a quantitative approach based on high-resolution pollen data

    Author : Daniel Fredh; Kvartärgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : This thesis explores the relationship between land-use and floristic diversity over the last three millennia in the uplands of southern Sweden. A quantitative approach based on high-resolution pollen data was applied, using the Landscape Reconstruction Algorithm (LRA), historical maps/aerial photographs, palynological richness and new ways to estimate past evenness at regional and local spatial scales, which enable estimates of the rate and degree of change in land-use and floristic diversity. READ MORE