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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

Using PCR Amplification and Genetic Sequence Analysis of 18S rRNA Genes to Survey the Microbial Diversity and Distribution of Eukaryotic Microbes Inhabiting Two Thermo-acidic Streams in Yellowstone National Park, Wyoming

Harvey, Robert, Jr. 06 August 2009 (has links)
A cultivation-independent approach, sequence analysis of 18S rRNA genes PCR-amplified from environmental DNA, was used to explore the diversity and distribution of eukaryotic microbes inhabiting algal mats in two acidic geothermal streams in Yellowstone National Park. The objectives were to: (1) clarify the identity of mat forming algae in Nymph Creek (2) survey microbial species in the Nymph Creek mat over seasonal intervals along a thermal gradient (3) compare microbial species in the Nymph Creek mat with those in Alluvium Creek mats (4) evaluate microbial species in algal mats formed on different substrates in Alluvium Creek. The results show that a novel red alga dominates high temperature regions (~50ºC) of Nymph Creek and two "Chlorella-like" algae predominate the cooler regions (<38ºC). The predominant algae in Alluvium Creek were distinctly different from those in Nymph Creek. Several stramenophiles and fungi were detected in each algal mat.
42

Changes in Microbial Communities and Geochemical Energy Supplies Across the Photosynthetic Fringe of Hot Spring Outflows in Yellowstone National Park

January 2018 (has links)
abstract: Utilizing both 16S and 18S rRNA sequencing alongside energetic calculations from geochemical measurements offers a bridged perspective of prokaryotic and eukaryotic community diversities and their relationships to geochemical diversity. Yellowstone National Park hot spring outflows from varied geochemical compositions, ranging in pH from < 2 to > 9 and in temperature from < 30°C to > 90°C, were sampled across the photosynthetic fringe, a transition in these outflows from exclusively chemosynthetic microbial communities to those that include photosynthesis. Illumina sequencing was performed to document the diversity of both prokaryotes and eukaryotes above, at, and below the photosynthetic fringe of twelve hot spring systems. Additionally, field measurements of dissolved oxygen, ferrous iron, and total sulfide were combined with laboratory analyses of sulfate, nitrate, total ammonium, dissolved inorganic carbon, dissolved methane, dissolved hydrogen, and dissolved carbon monoxide were used to calculate the available energy from 58 potential metabolisms. Results were ranked to identify those that yield the most energy according to the geochemical conditions of each system. Of the 46 samples taken across twelve systems, all showed the greatest energy yields using oxygen as the main electron acceptor, followed by nitrate. On the other hand, ammonium or ammonia, depending on pH, showed the greatest energy yields as an electron donor, followed by H2S or HS-. While some sequenced taxa reflect potential biotic participants in the sulfur cycle of these hot spring systems, many sample locations that yield the most energy from ammonium/ammonia oxidation have low relative abundances of known ammonium/ammonia oxidizers, indicating potentially untapped sources of chemotrophic energy or perhaps poorly understood metabolic capabilities of cultured chemotrophs. / Dissertation/Thesis / Masters Thesis Geological Sciences 2018
43

Spatial and Temporal Study of Heat Transport of Hydrothermal Features in Norris Geyser Basin, Yellowstone National Park

Mohamed, Ruba A. M. 01 May 2017 (has links)
Monitoring the dynamic thermal activity in Yellowstone National Park is required by the United States Congress. The continuous monitoring is important to maintain the safety of the visitors and park service personnel, plan and relocate infrastructure, and study potential impact from nearby geothermal development including oil and gas industry. This dissertation is part of a study initiated in the early 2000s to monitor the thermal activity of dynamic areas within the Park, using airborne remote sensing imagery. This study was focused in Norris Geyser Basin, the hottest geyser basin in the park, located near the northwestern rim of the Yellowstone’s caldera. The study is considered the first long-term comprehensive airborne remote sensing study in the basin which took place between August 2008 and October 2013. In this study, at least one 1-meter resolution thermal infrared image and three-band images (multispectral) were acquired and used to estimate year-to-year changes in radiant temperature, radiant flux, and radiant power from the thermal source in Norris. Presence of residual radiant flux in the ground from absorbed solar radiation and atmospheric longwave radiation was the main challenge to compere year-to-year changes in the thermal activity. This residual flux is included in the total radiant flux calculated through the remote sensing images which gives false estimates of the flux generated from the underling thermal source. Two methods were suggested in Chapters 2 and 4 of this dissertation to estimate the residual radiant flux. A method was developed in Chapter 2 to estimate the residual radiant flux in a bare ground area covered with hydrothermal siliceous sinter deposit. The method compared ground-based measurements with high spatial resolution airborne remote sensing measurements to estimate the residual radiant flux. In Chapter 4, a method was developed to estimate the residual radiant flux in the six surface classes in Norris, including bare ground, bare ground with siliceous sinter deposit, lakes and pools, river, forest, and grass. The assumptions and implications of each method were discussed to suggest a reliable method to estimate the geothermal radiant flux after subtracting the absorbed residual radiant flux. Chapter 3 provides an analysis of the four components of heat flux in the ground surface, including conduction of sensible heat, convection of sensible heat by liquid water and water vapor, and convection of latent heat by water vapor. The main purpose from the analysis was to assess the hypothesis that the convection and latent heat flux are negligible which therefore supported the results obtained from the analysis in Chapters 2 and 4.
44

From reformations to progressive reforms paradigmatic influences on wildlife policy in Yellowstone National Park /

Turney, Elaine C. Prange. January 2007 (has links) (PDF)
Thesis (Ph.D.)--Texas Christian University, 2007. / Title from dissertation title page (viewed Dec. 10, 2007). Includes abstract. Includes bibliographical references.
45

Conservation on a Regional Scale: Assessing the Yellowstone to Yukon Conservation Initiative

McGregor, Tanya January 2003 (has links)
Trends in environmental and resource management point to a more collaborative, integrated and regional approach, discussed in terms of concepts such as ecosystem management and collaborative planning. Such an approach has the potential to address some of the shortfalls previously encountered in environmental management and nature conservation, and has been the focus of considerable discussion in the literature. While a number of efforts are underway, there remains a need to identify how a regional approach can best be undertaken in practice. This research assessed the Yellowstone to Yukon Conservation Initiative (Y2Y), a recent regional conservation initiative in western North America, which has been the focus of considerable attention in the conservation community. This research assessed the strengths and limitations of the Yellowstone to Yukon Conservation Initiative in terms of its contribution to regional conservation planning, aiming to gain an understanding of implications for similar regional conservation efforts. Literature relating to regional conservation was examined to derive principles for effective regional conservation planning, as a basis for comparison with Y2Y. Drawing from needs of ecosystem management, collaborative planning, and related concepts, criteria were developed to assess the formative stages of a regional approach, emphasising capacity building measures and preconditions for success. In order to assess the strengths and limitations of Y2Y at a regional scale, this research attempted to obtain an understanding of how the Y2Y initiative was perceived by multiple stakeholders in regional conservation, as a basis for interpreting multi-stakeholder involvement and buy-in. A series of semi-structured interviews were conducted with a diverse range of individuals involved (directly and indirectly) in conservation planning, in two communities in the Y2Y region, Canmore and Crowsnest Pass, Alberta. These communities were selected to provide a degree of representation of areas within the Alberta portion of the Y2Y region. Perceptions of successes and obstacles of the initiative were compared with the criteria for effective regional conservation planning. Findings pointed to three recurring themes that influenced the initiative's ability to meet the criteria. These were the need to address both ecological and social components of conservation, the need to include diverse participants, and the need to operate at regional and local scales. These themes are consistent with limitations of traditional conservation and management practices critiqued in the literature, and suggest some substantial obstacles for employing a truly collaborative regional approach to conservation. Reflecting on the findings revealed that the Y2Y initiative was primarily understood as a vision. The Y2Y vision is one that has garnered a great deal of support and momentum, although there is a need to progress beyond the vision to address its potential and apply the ideals it puts forward. Recommendations of this study for Y2Y and similar initiatives included the need to build partnerships with more diverse groups, and the need for the Y2Y vision to be promoted in terms of some tangible, more specific goals. This study identified a need for biophysical, social science, and stakeholder information needs to be assessed and prioritised at the start of an initiative. Additionally, a vision was recognised as an effective rallying point from which to develop a regional conservation planning initiative.
46

Conservation on a Regional Scale: Assessing the Yellowstone to Yukon Conservation Initiative

McGregor, Tanya January 2003 (has links)
Trends in environmental and resource management point to a more collaborative, integrated and regional approach, discussed in terms of concepts such as ecosystem management and collaborative planning. Such an approach has the potential to address some of the shortfalls previously encountered in environmental management and nature conservation, and has been the focus of considerable discussion in the literature. While a number of efforts are underway, there remains a need to identify how a regional approach can best be undertaken in practice. This research assessed the Yellowstone to Yukon Conservation Initiative (Y2Y), a recent regional conservation initiative in western North America, which has been the focus of considerable attention in the conservation community. This research assessed the strengths and limitations of the Yellowstone to Yukon Conservation Initiative in terms of its contribution to regional conservation planning, aiming to gain an understanding of implications for similar regional conservation efforts. Literature relating to regional conservation was examined to derive principles for effective regional conservation planning, as a basis for comparison with Y2Y. Drawing from needs of ecosystem management, collaborative planning, and related concepts, criteria were developed to assess the formative stages of a regional approach, emphasising capacity building measures and preconditions for success. In order to assess the strengths and limitations of Y2Y at a regional scale, this research attempted to obtain an understanding of how the Y2Y initiative was perceived by multiple stakeholders in regional conservation, as a basis for interpreting multi-stakeholder involvement and buy-in. A series of semi-structured interviews were conducted with a diverse range of individuals involved (directly and indirectly) in conservation planning, in two communities in the Y2Y region, Canmore and Crowsnest Pass, Alberta. These communities were selected to provide a degree of representation of areas within the Alberta portion of the Y2Y region. Perceptions of successes and obstacles of the initiative were compared with the criteria for effective regional conservation planning. Findings pointed to three recurring themes that influenced the initiative's ability to meet the criteria. These were the need to address both ecological and social components of conservation, the need to include diverse participants, and the need to operate at regional and local scales. These themes are consistent with limitations of traditional conservation and management practices critiqued in the literature, and suggest some substantial obstacles for employing a truly collaborative regional approach to conservation. Reflecting on the findings revealed that the Y2Y initiative was primarily understood as a vision. The Y2Y vision is one that has garnered a great deal of support and momentum, although there is a need to progress beyond the vision to address its potential and apply the ideals it puts forward. Recommendations of this study for Y2Y and similar initiatives included the need to build partnerships with more diverse groups, and the need for the Y2Y vision to be promoted in terms of some tangible, more specific goals. This study identified a need for biophysical, social science, and stakeholder information needs to be assessed and prioritised at the start of an initiative. Additionally, a vision was recognised as an effective rallying point from which to develop a regional conservation planning initiative.
47

Developing a pioneer church through the Sunday School

Young, J. Stephen. January 2002 (has links)
Thesis (D. Min.)--Mid-America Baptist Theological Seminary, 2002. / Includes bibliographical references (leaves 124-130).
48

Cinder pool's sulfur chemistry : implications for the origin of life in hydrothermal envrionments

Sydow, Lindsey A 01 November 2013 (has links)
One chemoautotrophic origin of life theory posits the abiotic formation of alkyl thiols as an initial step to forming biomolecules and eventually a simple chemoautotrophic cell. The premise of this theory is that a recurring reaction on the charged surfaces of pyrite served as a primordial metabolism analogous to the reductive acetyl-CoA pathway (Wächtershäuser 1988) that was later enveloped by a primitive cellular membrane. Alkyl thiols have not previously been identified in terrestrial hot springs as unequivocally abiogenic, but they have been produced in the laboratory under hydrothermal conditions in the presence of a catalyst. I analyzed the dissolved gas content of several hot springs and conducted sterile laboratory experiments in order to evaluate the abiogenic formation of methanethiol (CH3SH), the simplest of the alkyl thiols. Specifically of interest was Cinder Pool, an acid-sulfate-chloride hot spring in Yellowstone National Park. This spring is unusual in that it contains a subaqueous molten sulfur layer (~18 m depth) and thousands of iron- vii sulfur-spherules floating on the surface, which are created by gas bubbling through the molten floor of the spring. This material could potentially serve as a reactive and catalytic surface for abiogenic CH3SH formation in Cinder Pool. Gas samples were collected from Cinder Pool and an adjacent hydrothermal feature in fall of 2011 using the bubble strip method. Two samples contained measurable quantities of CH3SH and other organic sulfur gases, with concentrations of all gases generally higher at the bottom of the pool. Laboratory microcosm experiments were conducted to replicate these findings in a sterile environment. Analog Cinder Pool water was injected into serum bottles containing different iron-sulfur compounds, including cinders collected from the pool itself, as catalytic surfaces for the CH3SH generating reaction. The bottles were then charged with hydrogen (H2), carbon dioxide (CO2), and carbon disulfide (CS2) as reaction gases and incubated for a week at temperatures between 60 and 100oC. Bottles used either powdered FeS, FeS2 (pyrite) or cinder material as a catalytic surface, and all of these surfaces were capable of catalyzing CH3SH formation. In bottles without imposed CS2, however, cinder material was the only surface that produced any detectable CH3SH. While CH3SH is central to the autotroph-first theory and has been synthesized in the laboratory (e.g. Heinen and Lauwers 1996), it has not previously been observed to form abiotically in natural systems. I have identified CH3SH in a natural hydrothermal feature where it is unlikely to have formed secondary to microbial activity, and I have duplicated these field findings in sterile laboratory experiments using the cinders as a reactive surface for formation. / text
49

From reformations to progressive reforms paradigmatic influences on wildlife policy in Yellowstone National Park /

Turney, Elaine C. Prange. January 1900 (has links) (PDF)
Thesis (Ph. D.)--Texas Christian University, 2007. / Includes bibliographical references (leaves 258-279). Also available online as a PDF file.
50

Park visitors and the natural soundscape : winter experience dimensions in yellowstone

Saxen, Shelley Walker. January 2008 (has links) (PDF)
Thesis (Ph.D.) --University of Montana, 2008. / Title from author supplied metadata. Description based on contents viewed on May 15, 2009. ETD number: etd-12112008-123204. Author supplied keywords: natural sounds ; recreation ; visitor experiences ; national park policy ; soundscape policy ; soundscape management ; winter visitor experiences ; wildland recreation. Includes bibliographical references.

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