South Georgia is renowned for the abundance of Antarctic krill (Euphausia superba) and a range of krill predators. Variability in krill availability at a range of scales, and the consequences of this for predator-prey interactions, mean that quantifying the spatially explicit demand for krill by those predators is essential to understanding the mechanisms underlying ecosystem changes in the region. In this thesis demand within a distinct study box to the northwest of the island has been assessed. The thesis has three sections; (1) the number of predators; (2) the distribution of predators; and (3) the demand for krill by those predators. (1) Predator densities with confidence intervals were determined from appropriately designed shipboard transect survey; counts of Antarctic fur seals (Arctocephalus gazella), macaroni penguins (Eudyptes chrysolophus), gentoo penguins (Pygoscelis papua), and Antarctic prions (Pachyptila desolata) were adjusted for sea state, distance from observer and dive behaviour. Providing the first at-sea predator density estimates for the region. (2) A comparison of the distribution of female Antarctic fur seals engaged in pup-rearing (using satellite telemetry) and the whole population that were not restricted to a single part of the population (from shipboard transect survey) was undertaken. Using two general additive models based on the relationship between seal distribution (one derived from transect and the other from telemetry) and the physical environment indicated that the spatial distribution of lactating females is representative of the general population. (3) Using the derived predator density, the local krill demand estimate was 2581 tonnes krill per day, a consumption rate of 0.45% per day of the concurrently estimated krill biomass (using shipboard acoustics). Antarctic fur seals accounted for 75% of this demand. This level of demand was less than the increase in biomass resulting from krill growth. However, based on the length-specific demand, determined from concurrent predator diet samples demand exceeded growth for krill >48mm.

Chickpea (Cicer arietinum L.) production on the semi-arid Canadian Prairies is challenging due to a short growing season and low and variable moisture. The current recommended chickpea population density of 44 plants m-2 is based on preliminary studies and a narrow range of 20 to 50 plants m-2. The aims of this study were to i) determine optimum population density of varying chickpea canopy types, i.e., leaf type and growth habit, by investigating seed yield responses at 30 to 85 plants m-2 and ii) identify desirable parental traits for breeding programs by assessing growth and yield parameter responses to varying leaf types and growth habits at a range of population densities. Field experiments were conducted from 2002 to 2005. Canopy measurements and calculated variables included light interception, biomass, growth rate, seed yield, harvest index, ascochyta blight severity and radiation- and water use efficiencies. The plant density which produced the highest seed yield when averaged over years for each location for each treatment revealed that a plant density of at least 55 plants m-2 produced a 23% to 49% seed yield increase above that of the currently recommended plant density. This indicates that a higher seed yield average over the long term in spite of periodic low seed yield episodes will be more profitable to producers. Increasing plant density increased lowest pod height significantly in all except one location-year but did not explicitly increase ascochyta blight severity or decrease individual seed size. This suggests that increasing the recommended chickpea plant density on the Canadian Prairies will increase seed yield but would neither negatively impact individual seed size nor ascochyta blight severity, especially, when combined with good agronomic practices. Fern-leaved cultivars had significantly higher maximum intercepted light (62 to 91%), seed yield (136 to 369 g m-2), harvest index (0.33 to 0.53), yield-based water use efficiency (0.56 to 1.06 g m-2 mm-1) and lower ascochyta blight severity (3 to 27%) than the unifoliate cultivars in all location-years. The fern-leaved cultivars also tended to show significantly higher cumulative intercepted radiation (221 to 419 MJ m-2) and biomass (306 to 824 g m-2) but leaf type showed no consistent effect on radiation use efficiency. Cultivars with bushy growth habit generally performed better regarding maximum intercepted light (62 to 90%), cumulative intercepted radiation (233 to 421 MJ m-2), biomass (314 to 854 MJ m-2), seed yield (120 to 370 g m-2), harvest index (0.37 to 0.50), yield-based water use efficiency (0.56 to 1.06 g m-2 mm-1) and ascochyta blight severity (7 to 36%) than the erect cultivars. The overall performance of the spreading cultivar was generally intermediate between the bushy and erect cultivars except for ascochyta blight severity where the spreading cultivar exhibited significantly lower disease severity (3 to 36%). Radiation use efficiency was generally not influenced by growth habit. Increasing plant population density generally increased intercepted light, biomass and cumulative intercepted radiation on each sampling day after seeding resulting in a general increase in seed yield. Harvest index, however, remained constant and ascochyta blight severity was generally stable but radiation use efficiency decreased with increasing population density. Chickpea cultivars with fern leaves and bushy growth habit at higher than currently recommended population densities would best utilize the limited resources of the short-season Canadian prairie environment to maximize and stabilize seed yield.

Chickpea (Cicer arietinum L.) production on the semi-arid Canadian Prairies is challenging due to a short growing season and low and variable moisture. The current recommended chickpea population density of 44 plants m-2 is based on preliminary studies and a narrow range of 20 to 50 plants m-2. The aims of this study were to i) determine optimum population density of varying chickpea canopy types, i.e., leaf type and growth habit, by investigating seed yield responses at 30 to 85 plants m-2 and ii) identify desirable parental traits for breeding programs by assessing growth and yield parameter responses to varying leaf types and growth habits at a range of population densities. Field experiments were conducted from 2002 to 2005. Canopy measurements and calculated variables included light interception, biomass, growth rate, seed yield, harvest index, ascochyta blight severity and radiation- and water use efficiencies. The plant density which produced the highest seed yield when averaged over years for each location for each treatment revealed that a plant density of at least 55 plants m-2 produced a 23% to 49% seed yield increase above that of the currently recommended plant density. This indicates that a higher seed yield average over the long term in spite of periodic low seed yield episodes will be more profitable to producers. Increasing plant density increased lowest pod height significantly in all except one location-year but did not explicitly increase ascochyta blight severity or decrease individual seed size. This suggests that increasing the recommended chickpea plant density on the Canadian Prairies will increase seed yield but would neither negatively impact individual seed size nor ascochyta blight severity, especially, when combined with good agronomic practices. Fern-leaved cultivars had significantly higher maximum intercepted light (62 to 91%), seed yield (136 to 369 g m-2), harvest index (0.33 to 0.53), yield-based water use efficiency (0.56 to 1.06 g m-2 mm-1) and lower ascochyta blight severity (3 to 27%) than the unifoliate cultivars in all location-years. The fern-leaved cultivars also tended to show significantly higher cumulative intercepted radiation (221 to 419 MJ m-2) and biomass (306 to 824 g m-2) but leaf type showed no consistent effect on radiation use efficiency. Cultivars with bushy growth habit generally performed better regarding maximum intercepted light (62 to 90%), cumulative intercepted radiation (233 to 421 MJ m-2), biomass (314 to 854 MJ m-2), seed yield (120 to 370 g m-2), harvest index (0.37 to 0.50), yield-based water use efficiency (0.56 to 1.06 g m-2 mm-1) and ascochyta blight severity (7 to 36%) than the erect cultivars. The overall performance of the spreading cultivar was generally intermediate between the bushy and erect cultivars except for ascochyta blight severity where the spreading cultivar exhibited significantly lower disease severity (3 to 36%). Radiation use efficiency was generally not influenced by growth habit. Increasing plant population density generally increased intercepted light, biomass and cumulative intercepted radiation on each sampling day after seeding resulting in a general increase in seed yield. Harvest index, however, remained constant and ascochyta blight severity was generally stable but radiation use efficiency decreased with increasing population density. Chickpea cultivars with fern leaves and bushy growth habit at higher than currently recommended population densities would best utilize the limited resources of the short-season Canadian prairie environment to maximize and stabilize seed yield.

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Made available in DSpace on 2016-12-23T13:47:02Z (GMT). No. of bitstreams: 1 Creuza Rachel Vicente.pdf: 3384838 bytes, checksum: c3eca90bf4886725c29d5e5904662f2b (MD5) Previous issue date: 2012-03-15 / Introdução: A ocorrência da dengue sofre influência do comportamento, estrutura social e distribuição da população e sua transmissão pode variar de acordo com as áreas do município. Seu prognóstico depende do diagnóstico precoce e da imediata instituição do tratamento. Este estudo avalia fatores associados à ocorrência da dengue, enfatizando a distribuição territorial e os relacionados à dengue grave. Métodos: Foram realizados dois estudos, sendo um transversal e outro retrospectivo, sobre a totalidade dos casos de dengue que ocorreram em Vitória no ano de 2011, com base nos dados do Sistema de Informações de Agravos de Notificação. Resultados: Entre os casos confirmados, 53,4% ocorreram em mulheres, 74,7% em maiores de 15 anos e 6,3% evoluíram para gravidade. Os territórios de saúde de Jardim Camburi, Maruípe, Ilha das Caieiras, Santa Martha e Santo André responderam por 41,6% das notificações. Quase metade dos casos foram concluídos por critério laboratorial e, destes, 80% realizaram sorologia. Em todos os territórios, mais de 20% dos notificados realizaram sorologia e, na maioria, mais de 51% tiveram resultado positivo. Nas regiões de São Pedro, Maruípe e Santo Antônio, os afetados eram principalmente jovens, enquanto nas regiões Continental e Forte São João, eram pessoas mais velhas. Dos 371 casos de dengue grave, 78,7% foram de dengue com complicações e 21,3% de febre hemorrágica da dengue. Sessenta e sete por cento dos casos ocorreram em pessoas com idade superior a 15 anos. As Regiões de Saúde de Maruípe e São Pedro foram responsáveis por mais da metade dos casos de dengue grave (56,35%). Houve associação estatisticamente significante entre ocorrência de febre hemorrágica da dengue com idades mais jovens (menores de 15 anos) e maior tempo decorrido na procura por atendimento. Também houve associação estatisticamente significante entre maior tempo decorrido na procura pelo atendimento e idade menor que 15 anos. Os casos de dengue grave estavam concentrados em faixas etárias mais jovens na região de São Pedro. Conclusão: A distribuição territorial não foi uniforme, e pode ser determinada pela alta densidade populacional e pelas condições socioeconômicas. As diferenças de idade entre as regiões podem estar relacionadas à incidência da doença nestes locais. A grande proporção de sorologias positivas e o número de exames realizados possibilitaram uma boa detecção e acompanhamento dos casos de dengue. Os resultados corroboram os de outras pesquisas que apontam uma mudança no perfil da febre hemorrágica da dengue nas Américas e no Brasil, com crescente acometimento de jovens, e apontam a demora no tempo de procura por atendimento, baixa qualidade urbana e alta endemicidade como possíveis fatores de risco. / Introduction: The incidence of dengue, influenced by human behavior, social structure and population distribution, may vary with respect to the geographical areas of a given city. Its prognosis depends on early diagnosis and prompt initiation of treatment. This study evaluates factors related to the occurrence of dengue, emphasizing the territorial distribution and risk factors for severe dengue. Methods: A cross-sectional and a retrospective study on all cases were conducted with dengue cases of Vitória in 2011, based on data from the Information System of Notifiable Diseases (SINAN). Results: 53.4% of confirmed cases occurred in women, 74.7% were 15 years old or older, and 6.3% were severe forms. The health territories of Jardim Camburi, Maruípe, Ilha das Caieiras, Santa Martha and Santo André accounted for 41.6% of reported cases. Almost half of the cases had final classification based on laboratory tests, and of these, 80% were submitted to serological tests. Of all territories, more than 20% of those reported cases had been submitted to serological tests, and more than 51% of them had a positive result. In the regions of São Pedro, Santo Antônio e Maruípe, the affected individuals were younger, while in Continental Region and Forte São João Region, they were older. Of the 371 cases of severe dengue, 78.7% were classified as dengue with complications and 21.3% were classified as dengue hemorrhagic fever, whose age distribution disclosed a frequency of 67.1% in individuals 15 years old or older. Regions of Maruípe and São Pedro were responsible for over half of cases of severe dengue (56.3%). There was a statistically significant association between the occurrence of dengue hemorrhagic fever and younger ages (under 15 years) and longer time interval between the beginning of symptoms and seeking for care. People younger than 15 years old take longer to seek for care. The frequencies of cases of severe dengue were concentrated in younger age groups in the region of São Pedro. Conclusion: The geographical distribution was not uniform, and can be influenced by the high population density and socioeconomic conditions. The age differences between regions may be related to disease incidence in these locations. A large proportion of positive tests and a great number of tests performed allowed a good detection and monitoring of dengue cases. The results corroborate those of other studies that indicate a change in the profile of dengue hemorrhagic fever in the Americas and Brazil, with growing involvement of young people, and indicate the time delay in seeking treatment, urban poor quality and high endemic scenario as possible risk factors.

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Spatial, temporal and population dynamics have influenced learner enrolments in Vhembe District primary schools in Limpopo, South Africa. Vhembe District primary schools have in recent years experienced closure of some of its primary schools due to declining learner enrolments. The dynamics of demographic factors such as migration, fertility and mortality cause fluctuations in the school-age population over time and across space. Poor economic development, the location of the district and the spatial distribution of primary schools make the situation in this rural-based district even more complex. The communities of Vhembe District are discontent about the state of affairs in the area regarding the provision of education and the closure of schools. The closure of schools destabilises the social cohesion amongst members of the community and disempowers them, while inadequate provision of primary school education makes them feel neglected and robbed of their constitutional right. This study investigated the causes of declining learner enrolment and the effect of the closure of schools on the communities. To achieve the objectives data came from questionnaires at household level and from interviews conducted with educators, circuit managers, officials in the Limpopo Education Department and traditional leaders. The study found that declining fertility and out-migration from the area are responsible for a declining school-age population. This is the reality and the communities of Vhembe District will have to live with it because overall learner enrolments continue to decline. Lack of a planning model in the former Venda territory led to an over-supply of primary schools thus schools in close proximity had to compete for learners. Poorly equipped schools and general development of the area exacerbate the problem and some members of the community perceive education in this district to be inferior. Younger economically active people are increasingly moving to places with better opportunities. This study offers some recommendations to alleviate the problems identified in Vhembe District. Application of a geographical approach to an adaptive strategy considers the natural environment in political, social and economic context. It suggests that education authorities could apply such a strategy to make the schools in rural areas more sustainable / Geography / D. Phil. (Geography)

Spatial, temporal and population dynamics have influenced learner enrolments in Vhembe District primary schools in Limpopo, South Africa. Vhembe District primary schools have in recent years experienced closure of some of its primary schools due to declining learner enrolments. The dynamics of demographic factors such as migration, fertility and mortality cause fluctuations in the school-age population over time and across space. Poor economic development, the location of the district and the spatial distribution of primary schools make the situation in this rural-based district even more complex. The communities of Vhembe District are discontent about the state of affairs in the area regarding the provision of education and the closure of schools. The closure of schools destabilises the social cohesion amongst members of the community and disempowers them, while inadequate provision of primary school education makes them feel neglected and robbed of their constitutional right. This study investigated the causes of declining learner enrolment and the effect of the closure of schools on the communities. To achieve the objectives data came from questionnaires at household level and from interviews conducted with educators, circuit managers, officials in the Limpopo Education Department and traditional leaders. The study found that declining fertility and out-migration from the area are responsible for a declining school-age population. This is the reality and the communities of Vhembe District will have to live with it because overall learner enrolments continue to decline. Lack of a planning model in the former Venda territory led to an over-supply of primary schools thus schools in close proximity had to compete for learners. Poorly equipped schools and general development of the area exacerbate the problem and some members of the community perceive education in this district to be inferior. Younger economically active people are increasingly moving to places with better opportunities. This study offers some recommendations to alleviate the problems identified in Vhembe District. Application of a geographical approach to an adaptive strategy considers the natural environment in political, social and economic context. It suggests that education authorities could apply such a strategy to make the schools in rural areas more sustainable / Geography / D. Phil. (Geography)

The specified area is located in the city district Brno - Židenice, near the railway station. The theme of the thesis is the architectural study of selected part of the multifunctional intense urban structure, which was solved in the pre-diploma project. Draft uses the building site intensively, provides high plot ratio and density of population, a wide range of functions in a relatively small area is related to the elimination of transportation. By using topography the proposal creates a permeable areas, buildings with relations to the surroundings and with quality public spaces and attractive housing. Pick-up railway cancels barrier and makes a space with landscaping. Readability is achieved by linking the territory from east to west by straight streets and from north to south by passages. The development creates three centers, the commercial center of the north, center of culture in the heart of the area and the center of relaxation and sport in the south. Basic grid of development has a checkerboard plan, which reflects the grid of surrounding structure. The new development varies in its scale, from large scale buildings in the parterre decays into smaller scale. Function division is horrizontal. There are underground parking, a parterre with shops and services, a floor with offices and work study open to the courtyard and housing on the upper floors. Thus formed structure provides enough light in the courtyards and flats. The segmentation is supported by materials, bricks in the parterre contrast with the monotone plaster on the upper floors.

La dengue circule en Polynésie française sur un mode épidémique depuis plus de 35 ans. Néanmoins, en dépit de la taille relativement faible de la population de Polynésie française, la circulation de la dengue peut persister à de faibles niveaux pendant de nombreuses années. L’objectif de ce travail de thèse est de déterminer si l'épidémiologie de la dengue dans le système insulaire de la Polynésie française répond aux critères d’un contexte de métapopulation. Après avoir constitué une base de données regroupant les cas de dengue répertoriés sur les 35 dernières années, nous avons réalisé des analyses épidémiologiques descriptives et statistiques. Celles-ci ont révélé des disparités spatio-temporelles distinctes pour l’incidence de la dengue des archipels et des îles, mais la structure de l'épidémie globale à l’échelle de la Polynésie française pour un même sérotype ne semble pas être affectée. Les analyses de la métapopulation ont révélé l'incidence asynchrone de la dengue dans un grand nombre d’îles. Celle-ci s’observe plus particulièrement par la différence de dynamique de l’incidence entre les îles plus peuplées et celles ayant une population plus faible. La taille critique de la communauté nécessaire à la persistance de la dengue n’est même pas atteinte par la plus grande île de Polynésie Française, Tahiti. Ce résultat suggère que la dengue peut uniquement persister grâce à sa propagation d’île en île. L'incorporation de la connectivité des îles à travers des modèles de migration humaine dans un modèle mathématique a produit une dynamique de la dengue davantage en adéquation avec les données observées, que les tentatives de modélisation traitant la population dans son ensemble. Le modèle de la métapopulation a été capable de simuler la même dynamique que les cas de dengue observés pour l'épidémie et la transmission endémique qui a suivi pour la période de 2001 à 2008. Des analyses complémentaires sur la différenciation de l'incidence de la maladie et de l'infection seront probablement instructives pour affiner le modèle de métapopulation de l'épidémiologie de la dengue en Polynésie française. / Dengue has been epidemic in French Polynesia for the past 35 years. Despite the relatively small population size in French Polynesia, dengue does not disappear and can persist at low levels for many years. In light of the large number of islands comprising French Polynesia, this thesis addresses the extent to which a metapopulation context may be the most appropriate to describe the epidemiology and persistence of dengue in this case. After compiling a database of dengue cases over the last 35 years, we used a number of descriptive and statistical epidemiological analyses that revealed distinct spatio-temporal disparity in dengue incidence for archipelago and islands. But the global structure of the epidemics of the same serotype were not affected. Metapopulation analyses revealed asynchronous dengue incidence among many of the islands and most notably larger islands lagged behind the smaller islands. The critical community size, which determines dengue persistence, was found to exceed even the largest island of Tahiti, suggesting that dengue can only exist by island-hopping. Incorporation of island connectedness through patterns of human migration into a mathematical model enabled a much better fit to the observed data than treating the population as a whole. The metapopulation model was able to capture to some extent the epidemic and low level transmission dynamics observed for the period of 2001-2008. Further analyses on differentiating incidence of disease and infection will likely prove informative for the metapopulation model of dengue epidemiology in French Polynesia.