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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.
261

Development of comparative genomic fingerprinting for molecular epidemiological studies of Campylobacter jejuni

Ross, Susan, University of Lethbridge. Faculty of Arts and Science January 2010 (has links)
This thesis reports the development of Comparative Genomic Fingerprinting (CGF), a rapid genotyping method for Campylobacter jejuni that assesses the conservation status of 20 genes previously described as having high intraspecies variability based on comparative genomics studies. This novel method for genotyping C. jejuni, CGF was validated two-fold. First, by comparison to flaA restriction fragment length polymorphism analysis, and second a subset of isolates was validated using two higher resolution CGF assays assessing 35 and 119 genes. CGF was then tested in a molecular epidemiological study of C. jejuni isolated from environmental, animal and human clinical samples from southern Alberta. Reservoirs of infection, subtypes associated with higher incidence of human infection, and the persistence of prevalent subtypes in animal/environmental reservoirs were identified. This thesis demonstrates that CGF analysis is robust and can be used to rapidly assess genetic similarity of C. jejuni isolates and to detect epidemiologically relevant clonal groups. / xii, 184 leaves : ill. ; 29 cm
262

Agricultural vulnerability to drought in southern Alberta : a quantitative assessment

Ren, Xiaomeng, University of Lethbridge. Faculty of Arts and Science January 2007 (has links)
Agricultural vulnerability is generally referred to as the degree to which agricultural systems are likely to experience harm due to a stress. In this study, an existing analytical method to quantify vulnerability was adopted to assess the magnitude as well as the spatial pattern of agricultural vulnerability to varying drought conditions in Southern Alberta. Based on the farm reported data and remote sensing imagery, two empirical approaches were developed to implement vulnerability assessment in Southern Alberta at the quarter-section and 30 meter by 30 meter pixel levels. Cereal crop yield and the Standardized Precipitation Index (SPI) were specified as the agricultural wellbeing and stress pair in the study. Remote sensing data were used to generate cereal crop yield estimations, which were then implemented in vulnerability quantification. The utility of the remote sensing data source for vulnerability assessment were proved. The spatial pattern of agricultural vulnerability to different severity and duration of drought were mapped. / xii, 127 leaves : ill. ; 29 cm.
263

The ecological consequences of hybridization between native westslope cutthroat trout (Oncorhynchus Clarkii Lewisi) and introduced rainbow trout (O. Mykiss) in south western Alberta

Robinson, Michael D., University of Lethbridge. Faculty of Arts and Science January 2007 (has links)
This thesis addresses the issue of hybridization between native westslope cutthroat trout (Oncorhynchus clarkii lewisi) and introduced rainbow trout (O. mykiss), giving strong consideration to their differing glacial refugia during the Wisconsin Glaciation. We hypothesize that having more recently derived from an anadromous form O. mykiss will possess life history characteristics more typical of a highly anadromous species. This hypothesis would also predict hybrids to be intermediate in these characteristics. In a comparison of growth rates and survivorship (Chapter 2) O. clarkii lewisi were found to employ a slower growing, longer lived strategy than O. mykiss, with hybrids typically being intermediate. Additionally, O. mykiss were also found to have aerobic and anaerobic metabolic capacities superior to O. clarkii lewisi in a first time comparison of these species (Chapter 3). These results support the glacial refuge hypothesis, but furthermore provide a potential explanation of the establishment of the elevational gradient commonly observed in hybridization studies. It would seem likely that O. mykiss would require more productive reaches being a faster growing, shorter lived species with higher metabolic costs. This study confirmed the gradient of O. mykiss persisting at lower elevations, trending through a hybrid zone to pure O. clarkii lewisi in headwater reaches and above migratory barriers (Chapter 2). A similar gradient was also reported when considering only the hybrid population, supporting the notion that habitat preference is under some genotypic control. The importance of migratory barriers was found to decrease with elevation suggesting potential additional limiting factors. Hybrid individuals were also found to be intermediate in morphological characteristics (Chapter 4). The confidence in differentiating between pure and non-pure O. clarkii lewisi was found to increase with the number of O. mykiss alleles (degree of hybridization) an individual possessed. Morphological-based identification was found to be an efficient, cost-friendly, preliminary assessment tool that could be useful in limiting the number of sites needing detailed genetic assessment. / 152 leaves : ill. (some col.) ; 29 cm.
264

Impact of long-term manure application on soil macronutrient levels in Southern Alberta

Simpson, Lisa G January 2010 (has links)
The role of manure applications on soil nutrient dynamics in years after manure applications cease has not been extensively studied. An investigation of two long-term manure trials in the Battersea Drain watershed in southern Alberta was undertaken in 2004 to determine changes in soil nutrient status three years after the initial study was completed. The investigation of the nutrient status of an intensive livestock operation was another component of the study. There was a significant decrease in levels of soil nitrogen, phosphorus and potassium in the plots that received manure application rates over 60 Mg ha-1. The nutrient status of the farm showed a net export of nitrogen and an accumulation of phosphorus and potassium in the soil. Recommendations for alternate methods for handling manure were presented. / x, 120 leaves : ill (some col.), col. maps ; 29 cm
265

Girls in science : the effect role models have on student interest / Maike L. Horn

Horn, Maike L., University of Lethbridge. Faculty of Education January 2011 (has links)
The central query of this study is focused around questions about increasing the numbers of girls and women in science. Surveys and focused group interviews were conducted with Grade 8 and 11 girls in two rural southern Alberta high schools to obtain an understanding of the impact they feel role models have on them with respect to an interest in science and the pursuit of a science career. While boys were also surveyed for comparison purposes, the focus of the study was girls‘ perceptions. Seemingly girls are just as interested in science topics as boys until they get to high school. While boys appear to continue to study science with interest, what prevents many girls from continuing to study topics they previously enjoyed? In elementary school many teachers are female but in high school a majority of science teachers are male. Does the gender of the teacher affect girls‘ interest in science? Extending this thought beyond the classroom: does the lack of positive visible female role models in science discourage girls‘ interest in science and science careers? The answers to these questions are complex. / xiv, 247 leaves ; 29 cm
266

The organization and variability of song in Northern House Wrens (Troglodytes aedon parkmanii)

Kaluthota, Chinthaka Dhanyakumara January 2013 (has links)
Hypothesized functions of complex song in birds include a role in mate attraction and territory defense and, through regional dialects, in genetic substructuring of populations and speciation. The necessary first step in testing such functions is a detailed characterization of song organization and variability. This is provided for the Northern House Wren (Troglodytes aedon), a species noted for complex song, but lacking detailed descriptions. The species was studied at two sites in Alberta with a sample of 15,000 songs from 15 males. Males sang in long bouts, each song composed of multiple syllable types and repeated many times before switching. The population repertoire of 27 syllables was almost entirely shared, but used to construct novel repertoires of up to 200 different song types for individual males without evidence of a ceiling. Additional flexibility and constraints in song construction are discussed in view of the above noted functions of song complexity. / x, 111 leaves : ill., maps ; 29 cm
267

Spring flowering trends in Alberta, Canada: response to climate change, urban heat island effects, and an evaluation of a citizen science network

Beaubien,Elisabeth G Unknown Date
No description available.
268

Reclamation of canal seepage affected land

Millette, Denis January 1989 (has links)
Deep interceptor drains are commonly used to control canal seepage in southern Alberta, Canada. Recently, shallow grid drainage was introduced. A study was initiated in 1987 to assess the effectiveness of grid drainage to intercept canal and natural groundwater seepage and reclaim the resulting saline affected land. / Using a groundwater flow model, MODFLOW, it was found that a single deep interceptor drain would have failed to intercept all canal seepage and maintain the water table downslope of the canal below the 1.0 m design water table depth. Conversely, simulations indicated that with a grid drainage system, all canal and natural groundwater seepage would be intercepted and the water table would remain below the design water table depth, with or without irrigation recharge that would maintain a steady state salt balance. / The benefits of fall irrigation were demonstrated using three test plots near the canal.
269

The Edmonton arts and youth feasibility study : a qualitative look at running an arts education program for youth in conflict with the law

Spinner, David. January 2005 (has links)
The Edmonton Arts and Youth Feasibility Study was conducted as a result of the question being asked "Can a structured art program be run with youth in conflict with the law?" It was a three month, arts-based, targeted prevention program run in an already existing drop-in centre for delinquent youth. This article reports on the qualitative findings of in-depth interviews conducted with the key stakeholders: participating adolescents (aged 14-19 years), lead artists, research assistants, and site directors. Findings suggest that the art curriculum, the strong relationships built, and the gains made were all strengths of the program. These gains include the acquisition of art skills, social skills and an improved ability to problem solve. Findings from this study also suggest the need for future research, including outcome studies and a program evaluation.
270

Strangers within our midst? : panhandling, identity and community conflict in Canada

Leech, Jessica F. January 2002 (has links)
Across Canada, municipalities have been struggling to alleviate the poverty of increasing numbers of homeless people and panhandlers on city streets. Simultaneously, tensions have risen between these street people and the general public. This thesis is a narrative study of the current conflict between panhandlers and other community stakeholders in Calgary, Alberta. This study presents the diverse viewpoints and voices of people who panhandle, homeless people, the general public, the downtown business community, social service providers, city bureaucrats and police officers. This study examines how identity politics and broader social ideologies shape face-to-face street encounters and influence debates over public policy at an institutional level. The relationship between panhandlers and the public is typically one marked by social distance. The current approach to panhandlers involves treating them as "strangers within our midst." This approach undermines their citizenship and heightens tensions within the community more so than would an approach that emphasizes their commonality with the larger society and their rights within civic space.

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