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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

A molecular investigation of dispersal, drift and selection to aid management of an invasion in progress

Rollins, Lee Ann, Biological, Earth & Environmental Sciences, Faculty of Science, UNSW January 2009 (has links)
Invasive species are problematic but their control can be difficult. When the history and dynamics of invasive populations are unknown, analytical techniques utilising genetic data can provide information to management. The application of these techniques has typically been limited to species with restricted dispersal or to localised geographic scales. Here these techniques are used in conjunction with traditional approaches to study the invasion of a highly vagile species over a continental scale. Originally introduced to eastern Australia, the common starling (Sturnus vulgaris) is expanding westward and has reached the southeast agricultural region of Western Australia (WA). Spatial, temporal and museum samples representing historical incursions into WA were used in genetic analyses to answer questions important to WA management agencies. Where possible, multiple marker classes were used to evaluate their relative ability to address these questions, including microsatellites, mitochondrial DNA (mtDNA), and a nuclear gene. Between two and four genetic groups were identified in Australia, and the localities on the edge of the range expansion (ERE) were consistently genetically differentiated from all others. Levels of genetic exchange between groups appeared to be low, suggesting that localised control may be effective. Analyses of historical samples indicated patterns of genetic exchange are temporally stable. This suggests that starlings will continue to arrive from the east, requiring vigilance from management. Consistently, a negative relationship was found between genetic diversity and date of first record, which may help in the future to distinguish ineffective surveillance from recent colonisations. Genetic evidence of female-biased dispersal indicated that control strategies preferentially targeting females may more efficiently limit dispersal than those targeting both sexes equally. Variants private to particular genetic groups were identified; tracking the spread of these variants may assist future monitoring programs in understanding ongoing exchange between groups. One mtDNA variant private to ERE localities showed dramatic temporal change, which could not be adequately explained by genetic drift or admixture, but may be explained by selection. Microsatellites were most useful in determining origins and identifying dispersers, mtDNA sequences provided a unique tool for ongoing monitoring of dispersal, and nuclear sequences had high levels of gene diversity and resolution of population structure.
142

Effects of trout on galaxiid growth and antipredator behaviour

Howard, Simon William January 2007 (has links)
The introduction of trout has been implicated in the declines in native fish fauna in New Zealand and worldwide. Since the introduction of brown (Salmo trutta) and rainbow (Oncorhynchus mykiss) trout to New Zealand in 1867, their distribution has spread and they have been implicated in the fragmentation of native fish distributions, particularly native non-migratory galaxiids. However, in the Upper Waimakariri basin the co-occurrence of trout and galaxiid populations is relatively common, even in streams where trout reach sizes known to be piscivorous. To investigate mechanisms that may regulate trout and galaxiid co-occurrence, I investigated differences in antipredator behaviour and growth rate between stream types with varying levels of trout presence. Using quantitative survey data collected between 1997 and 2006, I found that trout abundance was low and varied annually in frequently disturbed sites compared their high abundance in stable streams. This finding was used to classify streams into three population types, barrier (trout absent), disturbed (trout presence intermittent) and sympatric (constant trout presence). Using this classification, I tested the effects of trout chemical cues on galaxiid activity and refuge use in artificial channels. There were no differences in activity or refuge use between trout odour and there were no effects of population type or galaxiid size during both the day and the night. Using otolith weight-fish length relationships in galaxiids collected from each population type, I found that galaxiid growth rate was higher in disturbed streams than in stable streams either with or without trout. An experiment manipulating trout size and presence, over two months in a natural stream, found galaxiids from treatments without trout grew slower than those with trout. Slow growth rates in galaxiids above trout-migration barriers and in sympatry, combined with low growth rates in treatments without trout suggest that the mechanisms that regulate galaxiid growth are more complex than previously thought.
143

Characterisation of antibiotic-resistant Propionibacterium acnes from acne vulgaris and other diseases /

Oprica, Cristina, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 5 uppsatser.
144

Invasiveness of Yellow Toadflax (Linaria Vulgaris) resulting from disturbance and environmental conditions

Lehnhoff, Erik Adam. January 2008 (has links) (PDF)
Thesis (PhD)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Lisa J. Rew. Includes bibliographical references (leaves 198-217).
145

Stress response and hypothetical genes in Desulfovibrio vulgaris Hildenborough

Drury, Elliott C. January 2008 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. "December 2008" Includes bibliographical references.
146

Immunological and biochemical studies of the cystic fibrosis factor

Lashley, Felissa R., Daniel, William L. January 1973 (has links)
Thesis (Ph. D.)--Illinois State University, 1973. / Title from title page screen, viewed Oct. 14, 2004. Dissertation Committee: William L. Daniel (chair), Herman E. Brockman, David F. Weber, Arlan Richardson, Howard Hetzel. Includes bibliographical references (leaves 53-66) and abstract. Also available in print.
147

Riverscape-mediated effects of introduced trout on non-diadromous galaxiid fishes in New Zealand : a thesis submitted for the degree of Doctor of Philosophy in Ecology at the University of Canterbury /

Woodford, Darragh J. January 2009 (has links)
Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 126-141). Also available via the World Wide Web.
148

Aggregation von Mikroorganismen /

Eppler, Birgit. January 1981 (has links)
Universiẗat, Diss., 1980 u.d.T.: Eppler, Birgit: Aggregation von Bacillus cereus und Chlorella vulgaris in Gegenwart von Natriumionen und Kalziumionen--Karlsruhe.
149

EPR spectroscopic investigation of the active site of -hydrogenase a contribution to the elucidation of the reaction mechanism /

Foerster, Stefanie Anette Erica. Unknown Date (has links) (PDF)
Techn. University, Diss., 2003--Berlin.
150

Spektroskopische und elektrochemische Untersuchung der -Hydrogenase aus Desulfovibrio vulgaris Miyazaki F

Fichtner, Caroline. Unknown Date (has links)
Universiẗat, Diss., 2005--Düsseldorf.

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