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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.
101

Middle Voice in Northern Moldavian Hungarian

Hartenstein, Anne Marie 24 July 2013 (has links)
Based on 160 hours of recording collected in the villages of Săbăoani, and Pildeşti, Romania, the present research attempts to describe the middle voice system of Northern Moldavian Hungarian (NMH), an endangered language spoken by no more than 3000 speakers. Defining the middle voice category semantically rather than formally, it is argued that the various middle situation types in NMH can be placed relative to one another on a “semantic map” based on shared semantic properties such as 1) the confinement of the development of the action within the agent’s sphere to the extent that the action’s effect accrues back on the agent itself, 2) the degree of volitionality of the Initiator/Agent, and 3) the degree of affectedness of the Initiator/Agent. Polysemy structures are examined against the background of a common semantic map derived on the basis of cross linguistic investigation of a given grammatical domain. In working toward this end a detailed description of major patterns of meaning inherent in the NMH middle system, examining three types of morphological middles, syntactic middles, and lexical middles is presented. Cases in which the same verb can occur with or without a middle marker apparently having the same meaning are discussed. Moreover, seemingly minimal pairs in which two different morphological constructions occur with the same verb are analyzed. A detailed analysis of the differences in form and function of the two reciprocal syntactic middle constructions in NMH is provided. Regarding reflexive syntactic middles it will be shown that depending on the case marking taken by the reflexive anaphoric operator the function conveyed is different such as reflexives, intensifiers, causers, and experiencer. Finally, cases in which the same verb can convey a middle meaning by using a morphological middle marker or by using a syntactic middle construction are analyzed showing that there are main differences in the meaning those two strategies convey. Thus, the present paper identifies specific semantic properties relevant to the middle voice system in NMH, sets up some hypotheses regarding the relations among middle and related situation types and proposes some diachronic predictions regarding the middle voice system of NMH.
102

Climate change and endangered species in Canada: A screening level impact assessment and analysis of species at risk management and policy

Lundy, Kathryn N. January 2008 (has links)
Climate is a long-term driver of ecological change, but the rapidity with which climate is projected to change over the next century may push the limitations of ecological adaptability, to the detriment of biodiversity. Given their typically small populations, limiting biological traits and exposure to external stressors, species currently classified as “at risk” may be among the most vulnerable to climate change and least capable of adapting naturally. A screening level assessment of the impacts of climate change on endangered species in Canada was conducted by integrating knowledge of the current status and characteristics of each endangered species with projections of climate change and climate change impacts. It was determined that climate change may have a potential overall negative influence on more than half of all endangered species in Canada. However, while relatively few species were predicted to respond in an overall positive or neutral manner to climate change, a large portion of endangered species were classified as having insufficient information to generate a decision on the net influence of climate change; in many cases, these species were located at the northern extent of their range in warmer regions of Canada and have the potential to experience at least some benefits under climate change provided that other stressors are sufficiently mitigated. These results, as well as the inherent vulnerability of species at risk to environmental change, the potential for species at risk distributional shifts and the likelihood of increasing rates of species imperilment, demonstrate the need for greater consideration of the implications of climate change in species at risk management and policy. Canada’s Species at Risk Act (SARA) does not explicitly address the issue of climate change and limitations exist in SARA’s time-sensitive definition of wildlife species eligible for protection in Canada and in the interpretation of SARA’s mandates in the context of anthropogenically driven climate change. It is recommended that climate change be systematically considered in all species at risk assessments, recovery strategies and management plans and that SARA’s definition of a wildlife species be revaluated in light of shifting species distributions under climate change. Further recommendations to identify “values” that will assist in prioritizing species for conservation, to reassess the concept of an invasive species under climate change and to implement strategies that focus more broadly on the conservation of biodiversity and ecological integrity rather than individual species may require ethically complex discussions and decisions on the part of species at risk managers and policy makers. Future research should focus on informing species at risk management and policy by improving modeling capabilities at the species level, conducting in-depth analyses of priority species, and building knowledge of alternative species conservation strategies such as assisted colonization.
103

Climate change and endangered species in Canada: A screening level impact assessment and analysis of species at risk management and policy

Lundy, Kathryn N. January 2008 (has links)
Climate is a long-term driver of ecological change, but the rapidity with which climate is projected to change over the next century may push the limitations of ecological adaptability, to the detriment of biodiversity. Given their typically small populations, limiting biological traits and exposure to external stressors, species currently classified as “at risk” may be among the most vulnerable to climate change and least capable of adapting naturally. A screening level assessment of the impacts of climate change on endangered species in Canada was conducted by integrating knowledge of the current status and characteristics of each endangered species with projections of climate change and climate change impacts. It was determined that climate change may have a potential overall negative influence on more than half of all endangered species in Canada. However, while relatively few species were predicted to respond in an overall positive or neutral manner to climate change, a large portion of endangered species were classified as having insufficient information to generate a decision on the net influence of climate change; in many cases, these species were located at the northern extent of their range in warmer regions of Canada and have the potential to experience at least some benefits under climate change provided that other stressors are sufficiently mitigated. These results, as well as the inherent vulnerability of species at risk to environmental change, the potential for species at risk distributional shifts and the likelihood of increasing rates of species imperilment, demonstrate the need for greater consideration of the implications of climate change in species at risk management and policy. Canada’s Species at Risk Act (SARA) does not explicitly address the issue of climate change and limitations exist in SARA’s time-sensitive definition of wildlife species eligible for protection in Canada and in the interpretation of SARA’s mandates in the context of anthropogenically driven climate change. It is recommended that climate change be systematically considered in all species at risk assessments, recovery strategies and management plans and that SARA’s definition of a wildlife species be revaluated in light of shifting species distributions under climate change. Further recommendations to identify “values” that will assist in prioritizing species for conservation, to reassess the concept of an invasive species under climate change and to implement strategies that focus more broadly on the conservation of biodiversity and ecological integrity rather than individual species may require ethically complex discussions and decisions on the part of species at risk managers and policy makers. Future research should focus on informing species at risk management and policy by improving modeling capabilities at the species level, conducting in-depth analyses of priority species, and building knowledge of alternative species conservation strategies such as assisted colonization.
104

Demography and genetic diversity in <i>Tradescantia occidentalis</i> (commelinaceae)

Remarchuk, Kirsten Jennifer Dawn 03 July 2006 (has links)
Genetic diversity has rarely been the focus of study in species at risk in Canada. <i>Tradescantia occidentalis</i> is one of 157 species listed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC 2005a). This species is nationally threatened due to the limited number of populations, their geographic isolation from each other and from the main distribution in the United States of America, and habitat loss. The National Recovery Team for Plants at Risk in the Prairie Provinces and the Alberta Western Spiderwort Recovery Team have called for research into the habitat requirements, demography, and genetic diversity of <i>T. occidentalis</i> in Canada. As a result, this study was designed to address the following objectives: 1) to conduct an inventory of the Canadian populations, 2) to investigate intra- and interpopulation genetic diversity in <i>Tradescantia occidentalis</i>, and 3) to provide recommendations for the conservation management of this species. <p>Information on demography and plant communities in <i>Tradescantia occidentalis</i> habitats indicated that the numbers of individuals in the Saskatchewan and Manitoba populations were similar to previous surveys; however, the Alberta population was significantly larger in number than prior estimates, indicating population growth. Taxonomic lists were prepared for each province in habitats with and without <i>T. occidentalis</i>. Community types, as separated by RA analysis, differed by province and not by association with <i>T. occidentalis</i>. Euphorbia esula, an invasive species in Canada, was observed in the Saskatchewan and Manitoba populations but was absent in Alberta. <p> Using amplified fragment length polymorphisms (AFLPs), genetic diversity was assessed at the intra- and interpopulation levels. Relatively low levels of intrapopulation variation were observed in Saskatchewan and Alberta, while higher levels were found in Manitoba. Gene flow via pollen or propagule transfer may account for higher genetic diversity among the closely situated Manitoba populations. The lack of correlation between dendrogram topology and geographic distribution suggests panmixia in all populations. Levels of intrapopulation diversity were low to moderate depending on primer combination used, indicating that populations are isolated within each province. <p>Information on population demography and genetic diversity are important within a conservation context. The large number of individuals within each population and the perceived increase in some populations suggest that the existing populations of <i>Tradescantia occidentalis</i> are relatively stable. Although levels of genetic diversity are low in Saskatchewan and Alberta compared to Manitoba, it appears that all populations are adapted to their local environments based on their apparent size and stability. The most viable conservation strategy for this species is in situ protection. This should include controlling invasive plant species, monitoring grazing, and preventing further habitat fragmentation. Ex situ methods must also be explored. Transplantation of individuals from one population to the next may not be a successful conservation strategy due to the moderate level of population differentiation. Alternatively, it is recommended that a seed bank from each population be implemented in case of a drastic population decline.
105

Conservation of Antillean manatees in the Drowned Cayes area of Belize

Sullivan, Caryn Self 15 May 2009 (has links)
The purpose of this study was to determine how manatees use Swallow Caye, Drowned Cayes, and Gallows Reef, three distinct habitat types within the Belize Barrier Reef lagoon system near Belize City. Data were collected using boat-based point scan methods with the assistance of volunteers. Presence/absence and photo ID methods ensured consistency of data collection despite a changing pool of volunteer researchers. Results confirmed the mangrove and seagrass ecosystem between the Belize Barrier Reef and Belize City as important manatee habitat. Inconsistent with the prevailing "seasonal distribution hypothesis" for manatees in Belize, the probability of encountering manatees at Swallow Caye and in the Drowned Cayes was equal between dry and wet seasons. However, manatees were only observed at Gallows Reef during the wet season. Swallow Caye had the highest probability of encountering manatees, confirming traditional knowledge held by local tour operators, which led to the establishment of Swallow Caye Wildlife Sanctuary in 2002. In contrast to previous studies, my data suggest that at least 44% of the manatee population carry scars from non-lethal boat strikes. The proportion of scarred animals did not vary as a function of habitat type, season, or year. The probability of encountering manatees did not change between years, despite an exponential increase in cruise ship tourism. Marine Protected Areas (MPAs) and wildlife protection laws indicate that Belize is working to meet obligations under international agreements. However, there is still cause for concern. Manatees do not remain inside designated refuge boundaries; governmental agencies depend on co-management agreements with local non-governmental organizations for enforcement of rules inside MPAs; regulations governing human behavior outside MPAs are lacking; funds for monitoring and evaluation of MPAs are lacking. Manatee conservation strategies should be integrated into a system of riverine, coastal, and marine protected areas supported by additional tactics such as required manatee training for boat captains, slow zones at hot spots outside MPAs, and continued educational outreach. With few modifications and increased enforcement and monitoring, the Belize model for manatee conservation could lead to a shared "triumph on the commons" for the manatees and the user groups that shared their habitat.
106

Modeling aspects of the ecological and evolutionary dynamics of the endangered Houston toad

Swannack, Todd Michael 15 May 2009 (has links)
The goal of my dissertation was to describe the dynamics of a group of Houston toads located at the Griffith League Ranch (GLR), Bastrop County, Texas. My research included using statistical modeling to predict activity and abundance, mark-recapture techniques to estimate survivorship, and simulation modeling to explore the impacts of the difference in age at first reproduction and to project the future dynamics of the population at the GLR. From 2001 – 2005, 225 individual Houston toads (199 M : 26 F) were captured using two methods: breeding pond surveys and drift fences. Houston toads were neither caught equally among capture methods, nor across years. Toad activity was mostly confined within their breeding season, and activity was not continuous. A logistic regression indicated activity depended on time of year, mean precipitation, mean minimum daily temperature, and mean percent lunation as well as two-way interactions with moon-phase and other variables. Abundance depended on time of year, current precipitation, minimum temperature, and two-way interactions between time of year and the other two variables. Twenty-one of the 199 males (10.5%) and no females were recaptured among years. The probability of male survival was estimated using program MARK. Eight of 16 candidate models were supported and all but one contained precipitation as a covariate, indicating precipitation is important for Houston toad survival. Survivorship estimates varied from 0.1 to 0.41. The sex ratio was significantly male-biased. The odds of catching females in traps were 3.5 greater than capturing females in a pond, while the odds of capturing males in a trap were 0.28 compared to ponds. Results from a simulation model indicated the sex ratio is biased because of the difference in maturation times between males and females, coupled with high juvenile mortality. Results from an individual-based, spatially-explicit, stochastic simulation model, indicated a relatively low probability (~ 0.013) of B. houstonensis going extinct at the GLR within the next 10 years. Emergent properties of the model were similar to results observed in the field or reported in the literature. The model also identified that dispersal of Houston toads should be a future research priority.
107

Metapopulation Ecology and Recovery of the Endangered Lower Keys Marsh Rabbit

Schmidt, Paige McGee 2009 December 1900 (has links)
The Lower Keys marsh rabbit (LKMR, Sylvilagus palustris hefneri), a subspecies of marsh rabbit endemic to the Lower Keys, Florida, is threatened with extinction due to extensive coastal development of salt marsh habitats. LKMR recovery is limited by habitat loss and degradation from brush encroachment, predation by freeroaming cats (Felis catus) and raccoons (Procyon lotor), sea-level rise, and hurricanes. This study sought to determine local and landscape factors that influence LKMR metapopulation ecology and dynamics and to evaluate strategies for their recovery. I evaluated the influence of patch and landscape characteristics on LKMR densities, extinction, and colonization rates following Hurricane Wilma, and the response of LKMRs and salt marsh habitats to prescribed fire. I used estimates of population change based on annual monitoring data to validate vital rates, constructed a spatially explicit demographic model to evaluate various levels and spatial configurations of recovery scenarios implemented throughout the LKMRs range, and validated expected changes in parameter estimates using measures of habitat degradation and raccoon activity from known LKMR populations. I found LKMR densities were higher in patches with greater numbers of bunchgrasses and forbs and less edge and lower in patches with higher measures of raccoon activity. In response to a hurricane, I found the distance between LKMR patches and the coast had a negative influence on extinction probability; the distance between an extirpated and occupied LKMR patch had a negative influence on colonization probability and patch size had a positive influence. Adult LKMRs increased as woody cover <0.5 m decreased, herbaceous cover <0.5 m increased, and food availability increased in at least one site following prescribed fire. Model results indicated habitat management actions that improve carrying capacity of local rabbit populations and juvenile survival and control raccoon populations to increase rabbit reproductive rates are effective population recovery strategies. In total, my results provide a conservation planning tool that can be used to select recovery strategies and locations that will maximize benefits to LKMRs, thus improving their viability and recovery.
108

The winter ecology of piping plovers (Charadrius melodus) along the Texas Gulf Coast /

Zonick, Curtis A. January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 162-168). Also available on the Internet.
109

Tools for managing threatened species : improving the effectiveness of whio conservation : a thesis submitted for the degree of Doctor of Philosophy in Ecology at the University of Canterbury /

Whitehead, Amy. January 2009 (has links)
Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (p. 121-138). Also available via the World Wide Web.
110

Rapid endangered species assessment : a novel approach to improve extinction risk assessments in poorly known species /

Bianchi, Carlos A. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 155-180). Also available on the World Wide Web.

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