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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.
41

Field, lab and museum : the practice and place of life science in Yorkshire, 1870-1904

Alberti, Samuel John Matthew Mayer January 2001 (has links)
Later Victorian Yorkshire was home to a vigorous community of life science practitioners. In studying them, I reassess three dichotomies familiar to the contextualist historian of Victorian science: field and laboratory, science and society, and amateur and professional. I outline the refashioning of amateur and professional roles in life science, and I provide a revised historiography for the relationship between amateurs and professionals in this area and era. While exploring these issues, I examine the complex net of cultural and educational institutions where the sites for the practice of life science emerged and existed. Natural history practices shaded imperceptibly into other facets of civic culture. I present natural history as a leisure activity and as a resource utilised by the maturing provincial middle classes, one of a range of cultural activities within a network of voluntary associations. This thesis is arranged by institution: philosophical society, museum, civic college and field club. Each of these corresponds, loosely, to a site for science: respectively, lecture hall, museum, laboratory and field. The traditional `field versus lab' historiography ignores the many and varied sites for life science in this era, and conceals how far field-based natural history endured alongside the laboratory as it emerged as the hegemonic site for life science. I explore these and other issues by using the career of Louis C. Miall (1842-1921) as a narrative thread. Despite his activities as a lecturer, curator, field club president and laboratory biologist, Mall sought to construct a professional identity based solely on the authority of the laboratory, in contrast to that of the amateur naturalist. To take his partisan rhetoric at face value, however, is to ignore the variety and vitality of life science practices in Victorian Yorkshire.
42

Regulation of the population of symbionts in Anemonia viridis

Beaver, Ruth January 1996 (has links)
This study was undertaken to investigate the effects of different environmental variables on the association between the temperate anemone, Anemonia viridis and its symbionts. The effects of exposure to ammonium enrichment, changes in light intensity, feeding and starvation were studied. Many studies involving tropical associations have addressed this question by monitoring changes in the symbiont population density. However, the symbiont population density can change as a result of changes in the zooxanthella population or changes in the host biomass or host surface area. In addition, the zooxanthella population is determined by the rate of division and the rate at which cells are lost from the population. Anemones maintained at light intensities of 20 and 300E.m-2s-1 had similar population densities measured as cells.g host protein-1 in tentacles, however the zooxanthella division rate, measured as the mitotic index, increased from 2 to 4% with increasing light intensity within the range 20 to 300E.m-2s-1 after 3 weeks exposure. The specific expulsion rate also increased with light intensity over the range 50 to 300E.m-2s-1 from 0.0003 to 0.002 cells.cell-1.d-1. Although the mitotic index of zooxanthellae increased with increasing light intensity, the increase was much larger in animals receiving ammonium enrichment for 4 weeks. Under ammonium enrichment, the symbiont mitotic index increased from 2% at 20E.m-2.s-1 to 9% at 300E.m-2.s-1. The rate of ammonia uptake in A.viridis has previously been shown to be determined by the level of illumination and therefore the above observations indicate that the rate of cell division may be limited by low light intensity through limitation of ammonium uptake even under ammonium enrichment.
43

Framework of naturEnv KBNet : a distributed multimedia knowledge system network /

Liu, Li-Pin. January 1997 (has links)
Thesis (Ph. D.)--Lehigh University, 1997. / Includes vita. Includes bibliographical references (leaves 139-142).
44

"Maximum of wilderness" naturalists & the image of the jungle in American culture /

Enright, Kelly. January 2009 (has links)
Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in History." Includes bibliographical references (p. 251-260).
45

Selecting wildlife and environmental education programs for adult organizations in an urban area /

Leslie, Susan Stansbury, January 1993 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 107-113). Also available via the Internet.
46

Les principes de la méthode naturelle appliqués comparativement à la classification des végétaux et des animaux

Planchon, G. January 1860 (has links)
Thèse - Montpellier.
47

A limnological investigation of the psammon in Douglas Lake, Michigan, with especial reference to shoal and shoreline dynamics

Neel, Joe Kendall, January 1900 (has links)
Thesis--University of Michigan. / "Contribution from the Biological Station and the Department of Zoology, University of Michigan." "Reprinted from Transactions of the American Microscopical Society, vol. LXVII, no. 1, January, 1948."
48

Les principes de la méthode naturelle appliqués comparativement à la classification des végétaux et des animaux

Planchon, G. January 1860 (has links)
Thèse - Montpellier.
49

Environmental genomics and proteomics of plant-associated microbial dimethylsulfide degradation in a coastal salt marsh

Kröber, Eileen January 2016 (has links)
The methylated sulfur compound dimethylsulfide (DMS) plays a major role in the biogeochemical sulfur cycle and atmospheric chemistry. Bacteria are a main sink for DMS in the global sulfur cycle and can utilise DMS as a sole carbon and energy source. This study investigated the diversity and activity of bacteria capable of DMS degradation and associated with the salt marsh plant Spartina anglica known to be a producer of the DMS precursor dimethylsulfoniopropionate (DMSP). Initially, it was shown that S. anglica is rich in DMSP throughout the entire seasonal cycle in the Stiffkey salt marsh providing a likely hotspot for DMSP- and DMS-degrading bacteria. DMS uptake experiments demonstrated that DMS degradation takes place in the phyllosphere and rhizosphere of S. anglica and denaturing gradient gel electrophoresis (DGGE) and high-throughput amplicon sequencing of the 16S rRNA revealed the dominance of bacteria related to α - and γ- Proteobacteria, as well as Flavobacteria in the phyllosphere of S. anglica, whereas the rhizosphere was mainly colonised by members of the classes γ-, δ-, α-, and ε-Proteobacteria and Bacteroidia. The diversity of DMS-degrading bacteria associated with S. anglica was first assessed by enrichment culture. DGGE analysis and high-throughput sequencing diversity of DMS enriched samples using the 16S rRNA gene as a marker suggested the dominance of Piscirickettsiaceae, Methylophaga and Methylophaga-like bacteria in DMS-enrichments of phyllosphere and rhizosphere samples of S. anglica. A functional gene marker analyses was carried out using the gene encoding methanethiol oxidase (mtoX), a key enzyme in DMS degradation and the gene encoding a DMSP lyase (dddP) to determine the diversity of bacteria degrading DMS and DMSP, respectively, in the phyllosphere and rhizosphere of S. anglica. The analysis for mtoX showed a great diversity of this gene in phyllosphere and rhizosphere of S. anglica and that major clades of mtoX clustered together with Sedimenticola, Methylohalobius, Methylophaga and other mtoX clones previously detected in surface sediments of the same salt marsh. The results for the functional marker gene analysis for the dddP gene suggested the dominance of Ruegeria-like species and Roseobacter-like bacteria but also of unidentified Ddd+ bacteria in the phyllosphere and rhizosphere of S. anglica. In order to identify the active DMS degraders in the phyllosphere and rhizosphere of S. anglica stable-isotope probing (SIP) combined with DGGE and highthroughput sequencing of the 16S rRNA gene was carried out. The SIP experiments revealed the dominance of Piscirickettsiaceae, Methylophaga and Methylophaga-like microorganisms in the rhizosphere of S. anglica. However, the DMS-degrading microbial community in the phyllosphere seemed more diverse than in the rhizosphere and microorganisms like Halothiobacillus, Xanthomonadaceae, Rhodanobacter but also Piscirickettsiaceae seemed to be involved. A comparative proteomic and transcriptomic experiment of Methylophaga thiooxydans, a microorganism found in phyllosphere and rhizosphere of S. anglica, revealed the general pathways involved in methanol but especially DMS degradation. During DMS cycling the protein and the protein-encoding gene for the methanethiol oxidase (MtoX/mtoX) was highly expressed. A metaproteogenomic experiment provided an insight into the taxonomy and functional diversity of the microbial community associated with the Spartina anglica phyllosphere. Analysis of the metagenome provided evidence that the microbial community associated with S. anglica is dominated by γ-Proteobacteria such as Halomonadales, Alteromonadales, Oceanospirillales, and Thiotrichales and the alphaproteobacterial order Rhodobacterales and showed therefore a major difference to the bacterial community composition in the phyllosphere of for instance A. thaliana, clover, soybean and rice. The detection of DMSP lyase encoding genes and genes encoding proteins for DMS degradation confirmed the genetic potential for the observed DMSP and DMS degradation activity previously measured in the phyllosphere of S. anglica. The metaproteomic experiment allowed a first insight into the proteins expressed in the phyllosphere of S. anglica which also suggested that mainly γ-Proteobacteria and α-Proteobacteria are dominant populations occurring in this habitat. New insights were gained into the activity and diversity of DMS-degrading microbial communities associated with a salt marsh plant that represents a significant component of salt marsh plant communities world wide. Not only was the taxonomic and functional diversity of DMS-degrading microorganisms associated with S. anglica greater then previously realised, the observation of considerable potential of above-ground plant-associated DMS degradation in the phyllosphere demonstrates a previously unrealised sink in the DMS cycle in coastal ecosystems, which is clearly more complex than previously appreciated.
50

Developing conservation governance strategies : holistic management of protected areas in Nepal

Budhathoki, Prabhu January 2012 (has links)
The Buffer Zone (BZ) concept has been introduced in Nepal as a key component of the national biodiversity conservation strategy to mitigate the impacts of protected areas on local communities, and thereby reduce adverse impacts of local people on protected areas. Unlike traditional Buffer Zone programmes which are mostly limited to creating a protective layer and/or distributing economic benefits to local people, the Buffer Zone management approach in Nepal integrates livelihoods and conservation issues and their linkages in a more holistic and balanced manner. The programme has been successful in establishing a network of community institutions and in mobilising large numbers of local communities in conservation and community development. The research findings clearly indicate that the current Buffer Zone management approach based on park revenue sharing for community development has been successful in developing positive attitudes among local people towards protected areas. There is also evidence of improvement in the condition of forests and biodiversity in the Buffer Zone and a decrease in pressure inside the protected areas for basic forestry resources. The BZ communities also feel empowered by the Buffer Zone management programme. These outputs suggest that if properly designed, the Buffer Zone management programme can achieve both conservation and development objectives ensuring the long-term integrity of the protected areas. At the same time, however, the research has also revealed that the existing incentives and institutional arrangements adopted in the Buffer Zone management programme were necessary but not sufficient to address present and potential challenges in Chitwan National Park. There is a need to use additional instruments to demonstrate Buffer Zone management as a viable conservation governance strategy to expand conservation into the areas beyond park boundaries ensuring greater stability of the Park. Any park management strategy seeking to make tangible impacts on conservation, livelihood and governance should have five elements, namely; incentive, empowerment, education, enforcement and integration (IEEEI); and appropriate policy and institutional frameworks to implement them in an integrated way. If issues such as inclusion, equity, empowerment and integration are properly incorporated into the policies and programmes of the Buffer Zone management, the Buffer Zone management strategy adopted in Chitwan could be promoted as a viable model for the sustainable management of protected areas situated in a human dominated landscape.

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