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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.
121

Fitness consequences of avian habitat selection in dynamic landscapes : multi-scale evaluations in northern pintails

2014 October 1900 (has links)
According to theory, habitat selection by organisms should reflect the associated probability of survival or reproductive success. Understanding habitat selection, at multiple scales, is of interest not only from a theoretical perspective, but from an applied perspective for species conservation. Northern pintails (Anas acuta) are migratory, temperate-nesting birds that breed in greatest concentrations in the prairies of North America. Declining populations suggest that habitat loss and changing land use may have decoupled formerly reliable fitness cues from selection of suitable nest habitat. I used data from 62 waterfowl nesting study sites in prairie Canada (1997–2009), to examine whether nest survival, a primary fitness metric, at nest and habitat patch scales, was predictive of habitat selection at corresponding scales. In addition, I used systematic long-term annual pintail population monitoring data (1961–2009), and recruitment indices (juvenile:adult female ratio) from hunter harvest, to examine adaptive habitat selection among landscapes within the Prairie Pothole Region (PPR). The influences of breeding population density and landscape composition were examined at all scales. At nest and patch scales, pintail nest survival varied with nest initiation date, nest habitat, pair density, and landscape composition. Nest habitat preference reflected patterns in nest survival suggesting nest habitat preference is adaptive. Preference was generally low for habitats with low nest survival (e.g., spring-seeded cropland) and high for habitats with high nest survival (e.g., idle grassland). Differences in preference among habitats weakened at high breeding density and in landscapes with more grassland. Population-level recruitment tended to be greater when pintails settled in landscapes that were wetter than normal, contained more grassland, and were moderately variable in local elevation. Pintails were strongly associated with wetter than normal landscapes but shifted into cropland-dominated landscapes and flatter landscapes when populations were high. My results indicated that pintails express adaptive habitat associations with density-dependence acting through buffer mechanisms. Finally, I use the results of the above analyses to, 1) model and map the estimated long-term average spatial abundance of pintail pairs across the PPR as a function of landscape-level covariates, and 2) construct a deterministic model predicting pintail productivity given habitat and landscape attributes. These models allow conservation efforts to be targeted to affect the most birds, and they allow estimation of the demographic response to conservation actions.
122

The impact of rural to urban migration on forest commons in Oaxaca, Mexico

Robson, James P 17 January 2011 (has links)
This thesis investigates the impact of rural to urban migration on long-standing commons regimes in the Sierra Norte (northern highlands) of Oaxaca – the most biologically and culturally diverse state in Mexico. Since the second half of the twentieth century, local communities have been engaged with regional, national and international markets for wage labour, with many losing a significant percentage of their resident populations. The study shows how demographic and cultural change is impacting the two social institutions – cargos and tequios – that underpin the highly autonomous form of governance the region is famed for. The loss of able-bodied men and women has meant that these customary systems are struggling to remain operational. In response, a number of far-reaching changes have been introduced, including institutional adaptations and the forging of strong translocal ties that show potential for reducing the vulnerability of affected communities. However, while migration was temporary or circular for much of the 1970s, 1980s and 1990s, thus helping to maintain a balance between subsistence production and market engagement, a form of semi-permanent or permanent migration has come to dominate over the past decade and a half. This critical yet poorly recognised shift in migration dynamics has seen new and increased pressures emerge, and served to reduce the effectiveness of adaptive strategies at the community level. Within this context, the implications for commons theory are discussed, with two alternate frameworks (rational choice vs. moral economy) utilised to explain why institutions may persist, transform or fail in the face of change. In addition, a layer of complexity is added to the body of work examining the consequences of rural depopulation on Mexican forest landscapes and associated biological diversity. The study questions the assumption that rural to urban migration necessarily stimulates ecosystem recovery and enhances biodiversity conservation at a landscape scale. In fact, because of abandonment of a mosaic of use, the net effect may be an overall loss of biodiversity. From a policy perspective, the principal contributions of the study are especially pertinent at a time when funding agencies and government programs show belated interest in the consequences of out-migration for environmental management, resource use and rural livelihoods in tropical country settings.
123

Spanish Influenza in the City of Vancouver, British Columbia, 1918-1919

Buchanan, Sarah 21 September 2012 (has links)
During the last year of World War I (1918), a second deadly foe was causing mortality around the world. Spanish Influenza killed an estimated 50-100 million people worldwide, including 50,000 people in Canada during the 1918-1919 pandemic. This thesis examines the impact of Spanish Influenza on people living in Vancouver, British Columbia, Canada between June of 1918 and June of 1919. Statistical analysis with SPSS was used to determine the association between influenza-caused deaths and socio-demographic characteristics such as age, gender, immigration status, and employment. In Vancouver, those who were between the ages of 19 to 39, and those who were employed, showed higher odds of dying from influenza during the epidemic. / Graduate
124

The early socio-demographic impact of the HIV-1 epidemic in rural Zimbabwe

Gregson, Simon January 1996 (has links)
Theoretical work indicates that HIV-1 epidemics in sub-Saharan Africa will cause major demographic changes. The current study assesses the extent to which these changes can already be seen in two rural areas of Manicaland, Zimbabwe and investigates the determinants of the epidemic and its demographic impact. The study utilizes demographic survey methods and qualitative sociological techniques. Data analysis is conducted using statistical packages and is guided by insights generated from mathematical models of the epidemiology and demographic impact of HIV-1 infections. HIV-1 prevalence is high in both areas. Among women, HIV-1 infection is associated with age and marital status. Indirect evidence indicates that religion, education, migration and socio-economic characteristics of husband may also be important determinants. Each of these factors influences the pattern of sexual behaviour. Rates of sexual partner change are heterogeneous for women but appear more homogeneous for men. Mixing patterns are disassortative: men form partnerships with women with high and low rates of partner change. Mortality has undergone a recent upturn, almost certainly associated with HIV-1 infections. Adults aged 20-45 years and men, in particular, are most affected at this (early) stage of the epidemic. Religion is an important local determinant of demographic patterns, whose influence on mortality appears to be changing vua its effect on sexual behaviour and the spread of HIV-1. Orphanhood has increased, but, as yet, there is little change in population structure. Fertility has declined since the late 1970s. It is too early in the AIDS epidemic to see an impact of HIV-1 at the population level. However, some signs of behaviour changes which affect the proximate determinants of fertility were detected. These changes may accelerate the decline in birth rates, especially at younger ages. New demographic projections for Zimbabwe are developed, based on observed trends in HIV- 1 infection and fertility, and underlying behaviour patterns. These indicate substantial further increases in mortality, particularly among women and young children, greatly reduced population growth, relative shortages of young children and older adults, and further increases in orphanhood. Families and communities will require support in facing this slowly unfolding disaster.
125

Vartotojų lojalumo ugdymo sprendimai / Decisions of consumer loyalty development

Martišiūtė, Sandra 23 December 2014 (has links)
Darbe teoriniu lygmeniu išanalizuoti ir apibendrinti sprendimai, ugdantys vartotojų lojalumą, parengtas vartotojų lojalumo ugdymo struktūrinis modelis ir jis empiriškai patikrintas „Zara“ prekės ženklo pavyzdžiu. Pirmoje darbo dalyje atskleista vartotojų lojalumo konceptualioji esmė, išanalizuoti ir apibendrinti sprendimai, ugdantys vartotojų lojalumą bei pagrįstos vartotojų demografinių charakteristikų ir lojalumo sąsajos. Antroje darbo dalyje atlikta vartotojų lojalumo ugdymo teorinių modelių analizė. Remiantis teorinių tyrimų rezultatais, parengtas vartotojų lojalumo ugdymo struktūrinis modelis. Parengta vartotojų lojalumo ugdymo tyrimo metodika. Trečioje darbo dalyje atliktas vartotojų lojalumo ugdymo empirinis tyrimas ir apibendrinti jo rezultatai. Remiantis tyrimo rezultatais, empiriškai patikrintas vartotojų lojalumo ugdymo struktūrinis modelis. / The results of the theoretic and empiric research showed that brand and relationship marketing develops satisfaction and satisfaction creates consumer loyalty. The final work for Master consists of three parts. The first part reveals the conceptual nature of consumer loyalty. Also it consists of analyze and summary of consumer loyalty development decisions. The second part presents and analyzes the theoretical model of consumer loyalty development decisions. And based on results of the theoretical research the structured model of consumer loyalty development is presented. The third part consists analysis of results of empirical study and validation of theoretical model of consumer loyalty development decisions.
126

Dental Treatment Needs in the Canadian Population

Ramraj, Chantel 26 November 2012 (has links)
Objective: To determine the dental treatment needs of Canadians and how they are distributed. Methods: A secondary analysis of data from the Canadian Health Measures Survey was undertaken. Weights were applied to make the data nationally representative. Bivariate and multivariate regressions were used to identify predictors of need. Sensitivity, specificity, positive and negative predictive values were calculated to compare self-reported and clinically determined needs. Results: Of the 34.2% who required dental treatment, most needed restorative (20.4%) and preventive (13.7%) care. The strongest predictors of need were having poor oral health, reporting a self-perceived need for treatment and visiting the dentist infrequently. A discrepancy was found between clinical and self-reported needs. Conclusions: Roughly 12 million Canadians have unmet dental needs. A number of factors are predictive of having unmet dental conditions. Program and policymakers now have information by which to assess if their programs match the dental needs of Canadians.
127

The prevalence of alcohol-impaired driving in Alberta

Nurullah, Abu Sadat 11 1900 (has links)
This study explored the current state of alcohol-impaired driving as well as the changes in alcohol-impaired driving over time among Albertans. Based on self-report data from the annual Alberta Surveys 1991, 1992, 1997, and 2009, this study also traced the shift in the impact of standard demographic factors on alcohol-impaired driving in the province. Furthermore, the study examined social influence in alcohol-impaired driving in a representative sample in Alberta. Results indicated that in the past 12 months, 4% of the respondents had driven a vehicle while impaired, and 6.1% of the respondents had been passengers in a vehicle driven by an impaired driver. Chi-square test indicated that male, single, employed, non-religious, and younger respondents were more likely to have driven while impaired. Logistic regression analyses showed that a one-unit increase in social influence was associated with 5.32 times greater odds of engaging in impaired driving (OR = 5.32, 95% CI = 3.069.24, p < .001), controlling for other variables in the model. Findings also showed that self-reported alcohol-impaired driving has decreased substantially over the years (10.6% in 1991, 8.4% in 1992, 7.2% in 1997, and 3.7% in 2009). However, there had been little changes in designated driving. In addition, there had been a shift in age-related impaired driving, i.e., people aged 55-65+ reported impaired driving more in 2009 (4.8%) compared to 1991 (2.0%) and 1992 (2.2%); while individuals aged 18-34 and 35-54 reported impaired driving less in 2009 (4.8% and 2.6%, respectively) compared to 1991 (12.7% and 13.0%, respectively). The policy implications of the findings are discussed.
128

Detecting changes in coral reef environments in response to subtle disturbances: from organism to holobiont community responses

Juan Ortiz Unknown Date (has links)
Coral reef environments have been degrading steadily over the last few decades. It is generally accepted now that coral reefs are one of the first marine ecosystems to show measurable perturbations driven by global warming. Some of theses perturbations are consequence of extreme stochastic disturbances like hurricanes or extreme thermal anomalies and therefore, can be easily identified using broad indicators like coral cover. These indicators are easy to measure and provide a general description of the system in question. The detection and interpretation of more subtle perturbation in coral communities is more complicated, both logistically and conceptually. However, detecting chronic perturbations at an early stage can increase significantly the success of early mitigating management strategies. This thesis focuses on the development and application of highly sensitive indicators that can detect subtle perturbations in coral communities. It also studies the ecological interpretation of mild perturbations and their effect on the future structure of coral reef environments. The mild thermal disturbance experienced by the Heron Island reef in the south of the Great Barrier Reef during the 2005-2006 summer, and an environmental gradient along the central coast of Venezuela (south Caribbean Sea), were used as models to test the sensitivity of coral reefs to mild disturbances at different organisation levels (organism, population, and community). At the organismal level my results showed that the intensity of bleaching that a colony shows during a mild thermal disturbance is affected by the morphology of the colony as well as the substrates surrounding the colony. Colonies surrounded by sand bleached more than colonies surrounded by dead coral or rubble. I propose that reef specific information on the relative cover of sand, rubble, and dead coral can improve the fine scale accuracy of bleaching predicting models. Studying the same mild thermal disturbance at Heron Island, I showed how demographic parameters of some populations are more sensitive to mild thermal disturbances than coral cover (the most widely used response variable in coral monitoring programs around the world). Furthermore, my results suggest that the response of coral populations to mild thermal disturbance is different in nature and intensity to the respond observed during extreme thermal disturbances. Some taxa like Stylophora pistillata, are highly sensitive to extreme thermal disturbances, and tend to be the first to die under these conditions. In contrast, this taxon was extremely tolerant to the mild thermal disturbance of early 2006 in comparison to other taxa identified previously as more tolerant than S. pistillata. This difference in the response of coral environments to milder more common disturbances can have great influence in the trajectory that coral reefs follow in a rapidly changing world. Finally at a community level, I demonstrated how the power to detect the effect of environmental conditions on coral environments is drastically increased when the coral host-endosymbiotic algae relationship is interpreted holistically. The percentage of the variability of the community structure that can be explained by environmental variables in the central coast of Venezuela is doubled when the unit of selection considered is the holobiont instead of the coral host or the endosymbiont independently. This approach can be crucial for the detection of subtle changes in coral communities as the frequency and intensity of disturbances increase rapidly. The increase in detection power provided by the different approaches developed in this project can both improve our understanding of the structuring role of mild disturbances in coral communities as well as help identify the effect of disturbances in an early stage before the perturbation reaches catastrophic proportions. This early identification of perturbations can be used for the development of adaptive management strategies that can increase the resistance and resilience of coral reefs in the future.
129

Population change in Adelaide's peri-urban region : patterns, causes and implications /

Ford, Tania. January 1998 (has links) (PDF)
Thesis (M.A.)--University of Adelaide, Dept. of Geography, 1998? / Errata slip inserted. Includes bibliographical references (leaves 282-298).
130

Exploring the China apparel market : analysis of consumer's evaluative criteria, perceptions, and apparel expenditures by demographic variables /

Hsiao, Chin-Fen, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 124-133). Also available on the Internet.

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