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 72 for “"temperate regions"”.
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Vertical transmission in the culicoid vector as a possible mechanism for bluetongue virus transeasonality
… however, bluetongue disease is also enzootic in temperate regions, such as northeastern Colorado. The mechanism by which BTV overwinters in these regions, where the adult culicoid vector does not survive cold winter months, is unknown. The primary objective of this study was to determine if …
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Phytochemical and biological investigation of erigeron annus (L.) Pers for antimicrobial activity and potential DNA gyrase inhibitors
… ca. 390 species, widely distributed in in most temperate regions around the world. Erigeron annus (L.) Pers. (fleabane) is one of the most valuable plants in the genus, used in Chinese folk medicine to treat indigestion, malaria, enteritis, hepatitis and hematuria increasingly since the 1970s. …
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Key mechanisms of surface water pCO2 variability in the North Atlantic Ocean
… to the seasonal amplitude of surface pCO2 in temperate regions (>40°N), it is found that the gyre circulation strength, in response to the winter NAO index, drives this seasonal amplitude. Under positive NAO index winters, the formation of mode waters is favoured through strong surface …
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Salvinia molesta: An Assessment of the Effects and Methods of Eradication
… the 1930s, it has invaded most tropical and some temperate countries. <em>S. molesta </em>plants grow vegetatively and can increase in size rapidly. <em>S. molesta</em> can form thick mats of up to 1-meter-thick. There are a number of ways these thick mats negatively affect the environment: 1) …
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Environmental influences on moult and movement strategies in southern African waterfowl
Waterfowl annual life history events in north-temperate regions are driven primarily by predictable seasonal variations in temperature. In contrast, the spatio-temporal availability of adequate resources to waterfowl in the semi-arid regions of southern Africa is determined by rainfall which is …
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New structural systems in small-diameter round timber
… and fully renewable future in both developed temperate regions and the developing Global South. To reduce barriers to adoption, including project complexity and cost, a standardized "kit of parts" in whole-timber is proposed. This thesis proposes new designs for the first and most important …
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Exploring the utility of a GIScience approach to modeling invasive species: A case study of Ailanthus altissima
… invasive tree found throughout North America's temperate regions. Seed movement was modeled in two stages, primary and secondary dispersal; primary dispersal was calibrated using existing field data, while secondary dispersal was calibrated only qualitatively. Establishment potential was …
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Accessing Chilling Conditions For Perennial Fruit Crop Production in Kentucky
<p>Temperate Region fruit and nut trees, and many other perennial plants, require cool winter temperatures (chilling hours) to ensure leaf and flower bud production in the following season. Temperate Regions are characterized by variable winter and spring temperatures. Failure of meeting sufficient …
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Attempt to express the Xerophyta viscose stress-responsive gene, Xvcor, in yeast with view to functional analysis
… advances in the study of plants native from temperate regions, have established that cold acclimation is regulated at the gene expression leveL To study the function ofaXerophyta viscosa cold responsive protein that accumulates in plant cells under various environmental stresses, we have …
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Seed dispersal in South African trees: with a focus on the megafaunal fruit and their dispersal agents
… (70 – 90%) and a large proportion of trees in temperate regions (up to 60%) rely on vertebrates for their dispersal (Howe and Smallwood, 1982; Fleming et al., 1987, Willson, 1990). Vertebrate dispersers range in size from 5g mistletoe birds (Dicaeidae) to 7,500,000g elephants (Elephantidae). …
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Estimate of Production By a Population of Fathead Minnows, Pimpephales promelas, In a South Dakota Prairie Wetland
… Chapman (1967) reported that lentic waters in temperate regions have produced 2 to 15 gm/m²/yr. where a single species predominated. Production by fathead minnows in Pickering Slough was probably underestimated as a result of: 1) low initial brood stock density (less than five per acre); 2) …
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Sistema de classificação dos solos baseado na estrutura do espaço poroso
… for hydraulic properties involving tropical and temperate regions. In the context of SPSCS, we revealed a clear pattern of similarity among Aa curves within Families. The system was successfully implemented in an extensive and diversified soil database compiled in the study, where all soil Orders …
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Entomological considerations for domestication of pennycress, Thlaspi arvense, as a cash cover crop
… (Thlaspi arvense L.), a common annual weed in temperate regions, is being domesticated as a winter cover crop and oilseed crop for the Midwest U.S. corn-soybean rotation. This domestication presents significant agricultural and environmental benefits; however, understanding of the interactions …
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Variabilité de la respiration hétérotrophe du sol dans des écosystèmes agricoles: Analyse à différentes échelles spatiales et temporelles.
… driving variable in agricultural ecosystems in temperate regions. HR sensitivity to temperature, characterized by a Q10 differing from 2 in our experiments, was very likely influenced by substrate availability and quality. The impact of these last two factors was however never observed through …
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Hair Sheep Production in Temperate, Deciduous Appalachian Silvopastures
… have been proposed for silvopastures in humid temperate regions, but little data comparing animal performance from systems with different deciduous tree species are available. Forage and animal performance was compared from open systems (i.e., no trees) with that from silvopastures containing …
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Assessing the Effects of Biotic and Abiotic Factors on Ephedra viridis Seed Size
… in E. viridis seed mass. E. viridis residing in regions where there have been decreases in water availability over time and lower average water availability have larger relative seed mass than E. viridis in wetter regions. Lastly, E. viridis residing in regions where there have been increases in …
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GENETIC DISSECTION OF MATURITY DATE IN PEACH AND APRICOT REVEAL A ROLE FOR CONSERVED GENE NETWORKS
… economic relevance and widely cultivated in temperate regions due to the highly appreciated fruits. Due to its characteristics, peach became a model crop, a relatively small genome (about 256 Mb), diploidy (2n = 2x = 16) and low heterozygosity. Conversely apricot shows high levels of …
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Population Ecology of Invasive Lionfish (Pterois volitans/miles) in the South Atlantic Bight
… less research effort occurring in the temperate regions of their invaded range, such as the South Atlantic Bight. Lionfish life history estimates are important to modeling lionfish population growth, modeling future dispersal and evaluating the efficacy of different removal strategies. …
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