Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 43 for “"amphibian populations"”.
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Investigating the effects of organic pollutants on amphibian populations in the UK
Amphibians are undergoing dramatic population declines, with environmental pollution reported as a significant factor in such declines. Technologies are required that are able to monitor populations at risk of deteriorating environmental quality in a rapid, high-throughput and low-cost manner. The …
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Monitoring amphibian populations and the status of wood frogs and boreal chorus frogs in the Kawuneeche Valley of Rocky Mountain National Park
… as an appropriate state variable for monitoring populations of some amphibian species. In Chapters 1 and 2, I evaluate different aspects of the use of counts of egg masses as a state variable for monitoring wood frogs and other pond-breeding amphibians. Specifically, I assessed patterns of …
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Status of the Ozark Hellbender (Cryptobranchus Alleganiensis Bishopi): a Long-Term Assessment
A global decline in amphibian populations has been noted by biologists since the early 1970's. There are two problems with documenting the decline of amphibian populations: natural fluctuations in population numbers and lack of long-term data. I censused populations of the long-lived Ozark …
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Investigating the interactive effects of ultraviolet-B radiation and pesticides in amphibians
Amphibian populations are decreasing world-wide, which will not only lead to significant biodiversity loss but will also affect the structure and function of the ecosystems. Several causing factors have been proposed, including pesticide contamination and UVB radiation. However, amphibian declines …
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Evaluating efficacy of anti-Batrachochytrium dendrobatidis probiotic treatment on Pacific Chorus Frogs (Pseudacris regilla) at current and modeled climate change temperatures
<p>Amphibian populations are declining due to a variety of threats, including the chytrid fungal pathogen, Batrachochytrium dendrobatidis (Bd), the causative agent of the disease chytridiomycosis. Climate change and other stressors can have complicated interactions with amphibian disease. Some …
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Population dynamics of the Columbia spotted frog (Rana luteiventris): inference from long-term demography
<p>Worldwide extinctions of amphibians are at the forefront of the biodiversity crisis, with climate change figuring prominently as a potential driver of continued amphibian decline. Changes in both the mean and variability of climate conditions may affect amphibian populations in complex, …
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Population dynamics of the Columbia spotted frog (Rana luteiventris): inference from long-term demography
<p>Worldwide extinctions of amphibians are at the forefront of the biodiversity crisis, with climate change figuring prominently as a potential driver of continued amphibian decline. Changes in both the mean and variability of climate conditions may affect amphibian populations in complex, …
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Conservation genetics of a spotted salamander (Ambystoma maculatum (Shaw 1802)) local population in southeast Tennessee
Currently there is a worldwide amphibian decline with numerous causes. Because of this, it is important to understand how genetic variation in local amphibian populations is affected by disturbance. The goal of this study was to assess the genetic impacts of past chemical and ammunition storage and …
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The conservation genetics of a newly recognised Cape Peninsula endemic Rose's Mountain toad (Capensibufo rosei)
Declines and losses of amphibian populations are a global problem involving a complexity of interacting causes. Regardless of the fact that amphibians in Africa are among those predicted to be hit the hardest by anthropogenic global change, many species remain poorly studied. Capensibufo rosei, …
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Prevalence assessment of the amphibian chytrid fungus Batrachochytrium dendrobatidis across two habitat types in East Tennessee
In light of the biodiversity crisis facing amphibian populations globally, studies investigating the pathogenic amphibian fungus Batrachochytrium dendrobatidis (Bd) are a foremost priority for biologists. Understanding effects of habitat variation on Bd prevalence is important for identifying …
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Identification and isolation of microsatellite loci from the Trematode Echinostoma Trivolvis for use in interspecific and intraspecific variation studies
… in its lifecycle and has a significant impact on amphibian populations. Microsatellite markers were to be identified and isolated because of their highly variable nature and reported ease of use with PCR. Parasite DNA was extracted from planorbid snails from several locations within California …
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Quantitative, Competitive PCR and Fluorescent Microscopy Methods for the Study of Batrachochytrium dendrobatidis
Chytridiomycosis is a disease affecting amphibian populations worldwide and is caused by the parasitic fungus Batrachochytrium dendrobatidis (Bd). The catastrophic decline in numbers of amphibians dictates the need for full characterization of the fungus and amphibian host responses. Significant …
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Survey and Comparison of Amphibian Assemblages in Two Physiographic Regions of Northeast Tennessee.
<p>Declines in amphibian populations have prompted study of their ecology and distribution. The purpose of this study was to survey two sites located within different physiographic and one herpetofaunal region of Northeast Tennessee, comparing species composition and activity. The first, Henderson …
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ENERGY FLOW AND MACROINVERTEBRATE PRODUCTION IN PANAMANIAN HIGHLAND STREAMS: ASSESSING THE IMPACTS OF AMPHIBIAN DECLINES
Amphibian populations around the world have been declining rapidly over the past two decades, particularly in upland regions of the neotropics, where a fungal pathogen that causes chytridiomycosis has decimated many regions. Despite increasing concern over these and other dramatic losses of …
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The Effects of Aqueous Atorvastatin on Steroidogenesis of <i>Xenopus laevis</i> at Environmentally Relevant Concentrations
… to interfere with steroidogenesis in wildlife. Amphibians may be particularly susceptible to the effects of atorvastatin contamination because of their highly permeable integument. I used an amphibian model, <em>Xenopus laevis</em> to test the hypothesis that chronic exposure to low …
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The status and distribution of terrestrial amphibians in old-growth forests and managed stands
… thesis, I compare the abundance of terrestrial amphibians in old-growth forests and young and mature post-harvest stands. I also examine the habitat features with which they are strongly associated, and contrast these between old growth and second growth to gain insight on the specific effects …
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A Herpetofaunal Survey of Boehler Seeps and Sandhills Preserve with an Emphasis on Turtle Communities and the Ecology of Deirochelys Reticularia Miaria
Reptile and amphibian populations are rapidly declining world-wide, making an in depth understanding of herpetological communities of vital importance. Therefore, I used seven methods to conduct a herpetological survey of a diverse community in southeastern Oklahoma. I documented 53 species of …
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FROG DECLINES: EXPLORING CONNECTIONS AMONG CLIMATE CHANGE, IMMUNITY AND DISEASE
Frog and toad populations have been declining drastically all over the world. For the past 20 years, marked declines have been recorded for 40% of the frog and toad species in the Monteverde Cloud Forest Preserve (MCFP), Costa Rica, where climate change and disease have been implicated. Our study …
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