Sökning: "Tropics"

Visar resultat 1 - 5 av 66 avhandlingar innehållade ordet Tropics.

  1. 1. Genomic and morphological diversity of marine planktonic diatom-diazotroph associations : a continuum of integration and diversification through geological time

    Författare :Andrea Caputo; Rachel Ann Foster; Monika Quinones Winder; Ramon Massana; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phytoplankton; diatoms; cyanobacteria; diazotrophs; symbiosis; evolution; phylogenetics; confocal microscopy; qPCR; CARD-FISH; tropics; sub-tropics; Marine Ecology; marin ekologi;

    Sammanfattning : Symbioses between eukaryotes and nitrogen (N2)-fixing cyanobacteria (or diazotrophs) are quite common in the plankton community. A few genera of diatoms (Bacillariophyceae) such as Rhizosolenia, Hemiaulus and Chaetoceros are well known to form symbioses with the heterocystous diazotrophic cyanobacteria Richelia intracellularis and Calothrix rhizosoleniae. LÄS MER

  3. 2. Satellite measurements and climate modelling of water in the tropical upper troposphere

    Författare :Marston Sheldon Johnston; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Model; Satellite; Climate; Humidity; Radiation; Tropics;

    Sammanfattning : The International Panel on Climate Change (2007) has identified key areas of uncertainty with regards to future climate change, e.g., the upper troposphere. A portion of the uncertain- ties come from climate models and this makes model accuracy very important. LÄS MER

  4. 3. Observations of water vapour in the middle atmosphere

    Författare :Stefan Lossow; Jörg Gumbel; Jacek Stegman; Daniel R. Marsh; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; water vapour; mesosphere; stratosphere; dynamics; Odin satellite; limb sounding; microwave; tropics; polar winter; Meteorology; Meteorologi; meteorologi; Meteorology;

    Sammanfattning : Water vapour is the most important greenhouse gas and plays a fundamental role in the climate system and for the chemistry of the Earth's atmosphere. This thesis presents observations of water vapour in the middle atmosphere with a particular focus on the mesosphere. LÄS MER

  5. 4. Significance of N2 fixing planktonic symbioses for open ocean ecosystems

    Författare :Marcus Stenegren; Rachel A. Foster; Agneta Andersson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nitrogen fixation; diazotrophs; symbiosis; DDA; cyanobacteria; qPCR; piecewise SEM; microarray; tropics; subtropics; marine; open ocean; Richelia; Calothrix; Marine Ecology; marin ekologi;

    Sammanfattning : Di-nitrogen (N2) fixers, also called diazotrophs, are able to reduce atmospheric N2 into bioavailable nitrogen, giving them an advantage in open ocean regions with low dissolved inorganic nitrogen concentrations. The focus of this thesis are three lineages of symbiotic heterocystous filamentous types (het-1, het-2 and het-3), that associate with several genera of microalgae called diatoms (collectively referred to as Diatom Diazotroph Associations, DDAs). LÄS MER

  7. 5. Evaluation of suitable nursery areas for penaeid shrimps in shallow water systems in southern Mozambique

    Författare :Daniela de Abreu; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tropics; Southeast Africa; Shallow water; Estuaries; Nursery ground value; Decapods; Penaeidae; Carbon and nitrogen isotopes; Diet; Acetyl cholinesterase; Butyryl cholinesterase; Metals;

    Sammanfattning : Tropical shallow water habitats such as estuaries, mangrove forests and seagrass beds are important nursery areas for juveniles of many commercially important species including penaeid shrimp. Penaeids are one of the most important fishery resources worldwide, and in Mozambique they are the basis of a profitable commercial fishery, landing hundreds of tons per year. LÄS MER