Search for dissertations about: "species-specific"

Showing result 1 - 5 of 161 swedish dissertations containing the word species-specific.

  1. 1. Functional and structural characterizations of phytoplankton-bacteria interactions in response to environmental challenges

    Author : Eva Sörenson; Catherine Legrand; Elin Lindehoff; Jarone Pinhassi; Sonya Dyhrman; Linnéuniversitetet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Interactions; phytoplankton; microalgae; bacteria; communities; aquatic; diversity; functions; structure; species-specific; microbiome; core microbiome; response diversity; resilience; resource partitioning; competition; coexistence; amplicon sequencing; metatranscriptome; Akvatisk ekologi; Aquatic Ecology; Mikrobiologi; Microbiology;

    Abstract : Microorganisms, such as phytoplankton and bacteria, make up ≈70% of aquatic biomass and contribute 50-85% of the oxygen in Earth’s atmosphere. The microbial loop concept and the discovery of the large diversity in microbial communities acknowledge that biotic interactions between microorganisms in addition to resource competition enable the recycling of energy and nutrients in aquatic food webs. READ MORE

  2. 2. Species specific susceptibility testing for ß-lactam antibiotics. With special reference to staphylococci

    Author : Ann Cathrine Petersson; Avdelningen för medicinsk mikrobiologi; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; bakteriologi; mycology; Mikrobiologi; virology; bacteriology; beta-lactamase; staphylococcus; methicillin resistance; Microbiology; mecA susceptibility testing; virologi; mykologi;

    Abstract : The main objective of this thesis was to identify methods for the detection of ß-lactam resistance in staphylococci, bacteria often causing nosocomial infections. Detection of ß-lactam resistance in these species is difficult due to strong regulation of genes encoding for the two main resistance mechanisms, ß-lactamase production and the penicillin-binding protein (PBP) 2?. READ MORE

  3. 3. Mercury species transformations in marine and biological systems studied by isotope dilution mass spectrometry and stable isotope tracers

    Author : Lars Lambertsson; Wolfgang Frech; John Munthe; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Mercury; methylmercury; ethylmercury; Thimerosal; speciation; methylation; demethylation; brackish water sediment; natural waters; GC-ICP-MS; species-specific isotope dilution; isotope enriched tracers; Analytisk kemi; Analytical chemistry; Analytisk kemi; analytisk kemi; Analytical Chemistry;

    Abstract : This thesis focuses on the implementation of species-specific isotope dilution (SSID) methodology and stable isotope tracers to determine mercury species occurrence and transformation processes in-situ and during sample treatment. Isotope enriched tracers of methyl-, ethyl- and inorganic mercury were synthesised and applied in different combinations to marine and biological samples. READ MORE

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

    Author : Dong Nguyen Van; Wolfgang Frech; Anders Cedergren; Erwin Rosenberg; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; 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;

    Abstract : 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. READ MORE

  5. 5. Effects of behavioural flexibility and habitat complexity on predator-prey interactions in fish communities

    Author : Peter Eklöv; Gary G. Mittelbach; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; predator-prey interactions; behavioural flexibility; habitat complexity; foraging mode; sit-and-wait; group foraging; Perea fluviatilis; Esox lucius; Rutilus rutilus; size-structured interactions; species-specific antipredator behaviour; proximate cues; habitat distribution; temporal patterns;

    Abstract : .... READ MORE