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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.
321

Ecological niche modelling and its application to environmentally acquired diseases, the case of Mycobacterium ulcerans and the Buruli ulcer / Modélisation de niche écologique et son application aux maladies acquises de l'environnement, le cas de Mycobacterium ulcerans et l'ulcère de Buruli

Carolan, Kevin 12 December 2014 (has links)
L'ulcère de Buruli est une maladie émergente tropicale négligée. Il provoque une défiguration et une incapacité permanente pour les victimes. L'agent causal est Mycobacterium ulcerans. Cependant, le réservoir environnemental et le mode de transmission de cette bactérie ne sont pas connus. Les tentatives visant à gérer la maladie ont été freinées par le manque de connaissances concernant le mode de transmission ainsi que le réservoir environnemental de M. ulcerans. Certains écosystèmes et habitats ont été associés au risque de contracter cette mycobactérie, notamment les milieux aquatiques d'eau douce stagnants et perturbés par les activités humaines des régions tropicales. S'il n'existe pas de vecteur bien identifié, des insectes aquatiques Hémiptères sont fortement suspectés d'intervenir dans la vectorisation de cet agent infectieux à l'humain. Une compréhension complète de la distribution et du mode de transmission de la bactérie aiderait ainsi à la gestion de la maladie. Dans cette thèse, nous utilisons les outils issus de la modélisation de la niche écologique pour décrire la distribution de M. ulcerans. Suite à la construction d'un modèle au Cameroun, en Afrique Centrale, et testé avec une seconde base de données en Guyane Française (Amérique du Sud), nous trouvons que l'agent pathogène montre des variations saisonnières notables dans la répartition de nos sites d'étude, au Cameroun. Pendant la saison humide, M. ulcerans est plus fréquente dans les grands bassins versants et en absence de marécages, tandis que durant la saison sèche, la bactérie est plus présente dans les petits bassins versants où peuvent être présents dans les zones marécageuses. Notre étude a permis de générer des cartes de répartition de l'agent pathogène dans la région d'étude, qui pourront être utilisées dans des études ultérieures contribuant à mieux gérer le risque infectieux pour cette maladie. De plus, nous avons développé une modélisation des niches écologiques des insectes aquatiques soupçonnés d'être des vecteurs de l'agent pathogène. Basé sur un protocole d'échantillonnage d'insectes aquatiques qui couvre l'ensemble du Cameroun, nous avons construit un modèle suivant la méthode de l'entropie maximale. Ceci nous a permis d'interpoler notre modèle sur toute l'Afrique de l'Ouest. Nous avons ensuite testé une corrélation entre la répartition prévue des insectes potentiellement vecteurs, et la prévalence de l'ulcère de Buruli. Nous mettons en évidence une corrélation positive significative entre la répartition des insectes et la répartition de la maladie, et trouvons que cette corrélation varie significativement dans l'espace et le temps. Ceci est cohérent avec la possibilité d'une transmission multi-hôte pour cet agent pathogène.Enfin, en collaboration avec d'autres auteurs, nous avons pu explorer différents facteurs influençant la distribution de M. ulcerans, tels que les réseaux et la structure de la communauté biotique, ou encore l'impact de l'occupation du sol sur la distribution de l'ulcère de Buruli dans notre région d'étude d'Akonolinga au Cameroun. Et enfin nous avons testé le changement de distribution de la maladie à une plus grande échelle, entre le Bénin et le Nigeria. Cette thèse contribue à une meilleure compréhension de la distribution de Mycobacterium ulcerans et de l'ulcère de Buruli, fournissant des éléments de preuve d'une transmission multi-hôtes de la mycobactérie, ainsi que les premières cartes de répartition de l'agent pathogène pour la région d'Akonolinga au Cameroun. / The Buruli ulcer is an emerging environmentally acquired infectious neglected tropical disease. It causes permanent disability and disfigurement in victims. The causative agent is Mycobacterium ulcerans; however the environmental reservoir and mode of transmission of this bacterium are not known. Attempts to manage the disease have been hampered by lack of knowledge of the mode of transmission and the environmental reservoir of M. ulcerans. Certain environments have been associated with the disease, notably disturbed aquatic environments composed of small bodies of stagnant water. There is no known vector, though aquatic insects have been implicated as possible vectors. A full understanding of the distribution and mode of transmission of the bacterium would help in management of the disease.In this thesis, we use the tools developed in ecological niche modelling to describe the distribution of M. ulcerans. Following the construction of a model in Cameroon, Central Africa, and tested against a second database in French Guiana (South America), the pathogen is found to have notable seasonal changes in its distribution in our study sites in Cameroon. In the wet season, M. ulcerans is more common in large watersheds, while in the dry season the bacterium is more common in small watersheds. This enabled the generation of hazard maps of the pathogen distribution in the study region, which will be used in future studies and management of the disease. Following this we undertook ecological niche modelling to describe the distribution of the aquatic insects suspected to be vectors of M. ulcerans. Based on a sampling protocol that spanned the country of Cameroon, we undertake maximum entropy modelling, which enabled us to interpolate our model across all of West Africa. With these maps we explore the correlation between the predicted distribution of the insects to the prevalence of the Buruli ulcer. We find a significant positive correlation between the distribution of the insects and the distribution of the disease, and find that this correlation undergoes significant changes in space and time, consistent with the model of multi-vectorial transmission of the disease.Finally, in collaboration with other authors, we have assisted in exploring how the distribution of M. ulcerans changes according to community structure networks, how the distribution of the Buruli ulcer disease changes in our study region of Akonolinga, Cameroon, and how the distribution of the disease changes at a larger scale, between Benin and Nigeria. This thesis contributes to our understanding of the distribution and drivers of Mycobacterium ulcerans and the Buruli ulcer, providing evidence of multi-vectorial transmission of the disease, and the first hazard maps of the pathogen for Akonolinga, Cameroon.
322

Diversity of the soil microbial community and its functional aspects in man-influenced environments / Diversity of the soil microbial community and its functional aspects in man-influenced environments

CHROŇÁKOVÁ, Alica January 2009 (has links)
Diversity of the soil microbial community and its functional aspects were investigated in man-influenced environments, such as colliery spoil heaps in post mining sites and upland pasture used for outdoor cattle husbandry. The study was based on the cultivation of bacteria and streptomycetes as well as culture-independent approaches. Cultivated bacteria and streptomycetes were characterized by phenotypic and genotypic means. The culture-independent approaches were based on an analysis of environmental DNA in terms of both qualitative and quantitative parameters.
323

La pierre polie à l'embouchure de la rivière Sainte-Marguerite : caractérisation pétrographique, technologique et spatiale d’un locus de production de l’Archaïque moyen à supérieur

Gallo, Tiziana 01 1900 (has links)
No description available.
324

Ekologie lesního společenstva ptáků na Papui Nové Guinei

CHMEL, Kryštof January 2017 (has links)
The thesis addresses several aspects of ecology of lowland rainforest avifauna in Papua New Guinea. It describes spatial and temporal distributional patterns of abundance and diversity of bird community and different feeding guilds. More specifically, spatial patterns were explored in relation to topography, tree species composition, forest structure including vertical forest strata and inter-specific associations. The thesis also focuses on nest survival in continuous and fragmented forest, particularly in relation to nest predation.
325

Mortalidade materna no estado do Rio Grande do Sul, Brasil, no período de 1999 a 2008

Carreno, Ioná January 2012 (has links)
A mortalidade materna representa um evento de grande magnitude e transcendência que impacta negativamente à saúde no Brasil e no mundo. Integra o campo dos direitos humanos, sexuais e reprodutivos. Este estudo teve como objetivo geral caracterizar as razões de mortalidade materna no Estado do Rio Grande do Sul, entre o período de 1999 a 2008. Entre os objetivos específicos, a análise da RMM e RMME para as variáveis sociodemográficas, período de ocorrência e causa obstétrica do RS e das sete macrorregiões do Estado, no mesmo período; a distribuição espacial da RMM nos anos de 1999, 2003 e 2008 do RS nas macrorregiões e a verificação da mortalidade materna a partir do Programa de Humanização no Pré-Natal e Nascimento no RS. O estudo é do tipo ecológico, série temporal de agregado humano. A população foi de 845 óbitos maternos em mulheres entre 10 e 49 anos, ocorridos no Estado do RS no período de 1999 a 2008. As variáveis foram coletadas do SIM e do SINASC e, a partir deles, foram calculadas as RMM e as RMME, sendo analisadas por meio de regressão de Poisson com seus intervalos de confiança de 95%; no modelo de regressão, o ano foi usado como variável explicativa. Foram apresentados os valores do exponencial dos coeficientes, que mostram a variação nas razões de mortalidade materna no período analisado, juntamente com os seus respectivos intervalos de confiança de 95% e o valor-P do teste de Wald. Foram elaborados gráficos para análise de tendência, utilizando médias móveis da RMM para o Estado do RS. A distribuição espacial foi por meio da visualização da mortalidade materna nas macrorregiões do Estado do RS, nos anos de 1999, 2003 e 2008. Os principais resultados mostraram que a morte materna no Estado manteve-se com pouca oscilação nos dez anos de estudo e com valores acima do preconizado pela OMS. As macrorregiões identificadas com maiores valores da RMM são a Centro-Oeste, Norte e Serra. As características para morte materna são de mulheres acima de 30 anos de idade, com baixa escolaridade, menos de três anos de estudo e de cor/raça branca. Entre as características obstétricas do óbito, observou-se que no período da gestação/parto/aborto até 42 dias encontrou-se o maior período de risco, assim como as causas obstétricas diretas são a maioria. E, entre estas causas, a hipertensão arterial e a hemorragia estão entre os principais motivos de óbito materno no RS. Portanto, este estudo mostrou um panorama da saúde materna no Estado do RS e de suas macrorregiões, ficando claro que ao longo dos anos deste estudo não houve melhora do indicador, indicando que as políticas públicas, como PHPN, não impactaram na saúde materna e reprodutiva das mulheres. Esses resultados nos remetem a repensar o sistema e o atendimento de saúde da mulher, especialmente na atenção ao pré-natal. A morte materna é um evento que não pode esperar; a proteção da vida das mulheres em idade reprodutiva é um dever do Estado e uma obrigação dos profissionais que atendem essas mulheres. / Maternal mortality represents an event of major magnitude and transcendence that negatively impacts health in Brazil, as well as all over the world. It encompasses human, sexual and reproductive rights. The general purpose of this study was characterizing the ratios for maternal mortality in the state of Rio Grande do Sul (RS) between 1999 and 2008. The specific purpose is the analysis of MMR and SMMR for sociodemographic variables, period of occurrence and obstetric cause in all the state and its seven macro-regions along the same period; spatial distribution of MMR in 1999, 2003 and 2008 of RS in the macro-regions, and the monitoring done on maternal mortality by the Humanization Program of Prenatal Period and Birth in the state (HPPB). The type of this study is ecological, time series of human aggregate. The population/sample was of 845 maternal deaths of women between 10 and 49 years of age, happened in RS between 1999 and 2008. Variables were collected from the System of Information on Mortality and the System of Information on Live Births, and based on them, the MMR and SMMR have been calculated through Poisson regression with confidence intervals of 95%; in the regression model, where the year was used as an explicative variable. The exponential values of the coefficients were presented, showing the variation in the ratios for maternal mortality in the period analyzed, as well as with its respective confidence intervals of 95% and the p-value of the Wald test. Graphs were designed for tendency analysis using moving averages of the MMR for the state of RS. Spatial distribution was done through the visualization of maternal mortality in the macroregions of RS in 1999, 2003 and 2008. The most relevant results show that maternal mortality in this state has not oscillated much in the ten years of the study, with rates higher than those recommended by WHO. The macro-regions identified with the highest MMR values are the Mid-West, North and Hilly Region. Characteristics related to maternal mortality are: women above 30 years of age, with poor education (less than three years) and white. Regarding the obstetric characteristics of the death, it has been observed that in the period of gestation/delivery/abortion up to 42 days was the period with the greater risk, and direct obstetric causes prevail. Among these causes, blood hypertension and hemorrhage are among the main reasons for maternal death in RS. Therefore, this study shows an outlook of maternal health in the State of RS and its macro-regions, making it obvious that along these years there has not been an improvement in this indicator, thus suggesting that public policies such as HPPB have not impacted maternal and reproductive health of women. These results recommend us to rethink the system of assistance to women’s health, especially regarding the prenatal period. Maternal death is an event which cannot be overlooked; protecting women’s lives in reproductive age is a duty of the State and an obligation of the professionals who assist these women. / La mortalidad materna representa un evento de gran magnitud y trascendencia que repercute negativamente en la salud del Brasil y en el mundo. Se integra el campo de los derechos humanos, sexuales y reproductivos. Este estudio tuvo como objetivo caracterizar las razones de mortalidad materna en el estado de Rio Grande do Sul, entre el período 1999 a 2008. Entre los objetivos específicos, el análisis de la RMM y el RMME por las variables sociodemográficas, el tiempo de ocurrencia y causa obstétrica de RS y siete regiones geográficas del estado, en el mismo período, la distribución espacial de la SPR en 1999, 2003 y 2008 del RS en la macro regiones y la verificación de la mortalidad materna por el Programa de Humanización del Prenatal y Nacimiento en la RS. El estudio es del tipo ecológico, de series de tiempo de agregación humana. La población era de 845 muertes maternas en mujeres de entre 10 y 49 años de edad en el estado de RS en el período 1999 a 2008. Las variables se recogieron en la tarjeta SIM y SINASC, y de ellos se calcularon MMR y RMME se utilizó la regresión de Poisson con intervalos de confianza de 95% en el modelo de regresión, el año se utilizó como variable explicativa. Se presentan los valores de los coeficientes exponenciales, mostrando la variación en tasas de mortalidad materna en el período analizado, junto con sus respectivos intervalos de confianza de 95% y el valor de P de la prueba de Wald. Se prepararon tablas de análisis de tendencias, utilizando medias móviles de la vacuna MMR para el estado de RS. La distribución espacial fue a través de la visualización de la mortalidad materna en las regiones geográficas del estado de RS, en 1999, 2003 y 2008. Los principales resultados mostraron que la mortalidad materna en el estado se mantuvo con pocas variaciones en los diez años de estudio y por encima de los valores recomendados por la OMS. Las macro regiones identificadas con los valores más altos de la RMM son el medio oeste y el norte de la Sierra. Las características de las muertes maternas corresponden a mujeres de más de 30 años de edad, bajo nivel educativo, menos de tres años de estudio y de color blanco / carrera. Entre las características obstétricas de defunción, se observó que durante el embarazo / parto / aborto hasta 42 días se reunió con el periodo de mayor riesgo, así como las causas obstétricas directas son la mayoría. Y entre estas causas, la hipertensión y las hemorragias son las principales causas de muerte materna en la República Srpska. Por lo tanto, este estudio mostró una foto de la salud materna en el estado de RS y de sus regiones macro, dejando en claro que en los últimos años de este estudio no hubo una mejora del indicador, lo que indica que las políticas públicas, como PHPN, no tuvo ningún impacto en la salud materna y reproductiva las mujeres. Estos resultados nos llevan a repensar el sistema y el cuidado de la salud de las mujeres, especialmente en la atención a la atención prenatal. La muerte materna es un evento que no puede esperar, para proteger las vidas de las mujeres en edad reproductiva es el deber del Estado y la obligación de los profesionales que tratan a estas mujeres.
326

The impact of the implementation of government policy on the spatial distribution of emerging farmers in the Mopani district in the Limpopo province of South Africa

Mamabolo, Makhudu Edward 08 1900 (has links)
Agriculture plays a major role in development, as it creates jobs, develops the economy and reduces poverty. An important drawback in agriculture in South Africa is access to agricultural land and other agricultural resources by African farmers. Many African farmers still own small units of land, which are still mostly used for subsistence farming. These racial inequalities in the agricultural sector date back to colonial and apartheid eras. During the apartheid era, government policies separated white farmers from black farmers resulting in an unequal spatial distribution of farming and development in the country. The post-apartheid government that came into power in 1994 was committed to the eradication of racial legislation and implemented new agricultural policies. Twenty years later many inequalities still exit within the agricultural sector. There is a need to investigate the social and spatial inequalities in the emerging farming section. Since the Limpopo province is one of the poorest provinces in South Africa, consisting of large areas of former homelands, the aim of this research is to investigate and describe the impact of the implementation of agricultural policies on the spatial distribution of the emerging farming sector in the Mopani District of the Limpopo province. This research was done within the framework of the post-modernism paradigm. The study used mostly qualitative data but some quantitative data and methods were also used. Primary data was collected from sampled emerging farmers in the Mopani district, some officials from the local municipality and one provincial official. Evidence from analysed data indicated that the uneven spatial distribution of farms still exists despite numerous policies and programmes implemented by government through its provinces, and local and district municipalities. Structurally there is a lack of proper coordination, inadequate provision of both human and material resources, monitoring and evaluation of the implementation of policies and programmes are some contributory factors. It is recommended that policies be implemented that strategically target investment and infrastructural development to reduce poverty, unemployment and uneven spatial distribution of farms in the Mopani district municipalities in the Limpopo province. / Geography / 1 online resource (xvi, 128 leaves) : color maps / D. Phil. (Geography)
327

Distribuição espacial e temporal de proteínas e ácidos húmicos em lagoa rasa subtropical

Centuriao, Tiago Carrard January 2016 (has links)
O presente trabalho avaliou a variabilidade espacial e temporal de ácidos húmicos (HA) e proteínas (PROT), em uma grande lagoa rasa subtropical. Para tanto, foi usado Cromatógrafo Líquido de Alta Eficiência por Exclusão de Tamanho (HPLC-SEC). Foram incluídas como variáveis explanatórias, carbono orgânico dissolvido (COD), nitrogênio total (NT), nitrogênio total dissolvido (NTD), cor, pH e temperatura. A área de estudo foi a Lagoa Mangueira, uma grande lagoa rasa oligo-mesotrófica inserida ao Sistema Hidrológico do Taim – SHT. As amostras foram coletadas em quatro campanhas, durante o ano de 2010, em dezenove pontos diferentes, compreendendo as zonas litorâneas e pelágica, localizadas no sul, centro e norte da lagoa. Resultados indicaram que a Lagoa Mangueira apresenta heterogeneidade temporal interanual em relação a estas variáveis, ao mesmo tempo que possui um perfil longitudinal homogêneo, não evidenciando um arranjo espacial definido. / The present work evaluated spatial and temporal variability of humic acids (HA) and proteins (PROT) in a large subtropical shallow lake. For this purpose, High Performance Liquid Chromatograph by Size Exclusion (HPLC-SEC) was used. Dissolved organic carbon (DOC), total nitrogen (TN), total dissolved nitrogen (TDN), color, pH and temperature were included as explanatory variables. The study area was Mangueira lake, a large shallow oligo-mesotrophic lake located into the Taim Hydrological System. The samples were collected in four samplings during the year 2010 at nineteen different points, including the littoral and pelagic zones, located in the south, center and north of the lake. Results showed that the Mangueira lake presents interannual temporal heterogeneity in relation to these variables, at the same time that it has a homogeneous longitudinal profile, not evidencing a defined spatial arrangement.
328

Caracterização dos campos neutrônicos obtidos por meio de armadilhas de nêutrons a partir da utilização de água pesada (D2O) no interior do núcleo do reator nuclear IPEN/MB-01 / Characterization of the neutronic fields obtained by means of flux traps from heavy water (D2O) inside the core of the IPEN/MB-01 nuclear reactor

SANTOS, DIOGO F. dos 23 July 2015 (has links)
Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-07-23T11:04:17Z No. of bitstreams: 0 / Made available in DSpace on 2015-07-23T11:04:17Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
329

Análise espacial de populações naturais de Dipteryx alata Vogel. : Subsídio para coleta de sementes /

Lima, Diana Carla de Oliveira Santana January 2016 (has links)
Orientador: Mario Luiz Teixeira de Moraes / Resumo: The spatial distribution pattern of tree species is one of the most important factors for the understanding of the ecological interrelationships occurring in a population or community forestry, it is vital to the understanding of how a certain species uses the resources available to establish and reproduce in a given space. Interpretation of the results of the spatial analysis of tree species provides significant subsidies for the understanding of these phenomena and indication of individuals for genetic conservation programs and forest promotion. In this context, the objective of the work was to study the spatial distribution of six natural populations of arborea specie baru (Dipteryx alata Vogel.) using the Moran index associated with a Geographic Information System and descriptive statistics of their silvicultural attributes. These populations are located in the municipalities of Paulo de Faria/SP, Campina Verde/MG, Ituiutaba/MG, Brasilândia/MS, Campo Grande/MS e Itarumã/GO. All populations had a growth over 45 cm in relation to the DAP (Diameter at Breast Height) attribute. Taking into account that the DAP attribute has a higher dendrochronological correlation, the estimated age of these natural populations would be in the range between 40 and 63 years. As regards the calculation of Moran index, populations of Ituiutaba and Itarumã presented random spatial distribution pattern, pointing high variability among its individuals, so the collection of seeds for ex situ conserv... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
330

Distribuição espacial e temporal de proteínas e ácidos húmicos em lagoa rasa subtropical

Centuriao, Tiago Carrard January 2016 (has links)
O presente trabalho avaliou a variabilidade espacial e temporal de ácidos húmicos (HA) e proteínas (PROT), em uma grande lagoa rasa subtropical. Para tanto, foi usado Cromatógrafo Líquido de Alta Eficiência por Exclusão de Tamanho (HPLC-SEC). Foram incluídas como variáveis explanatórias, carbono orgânico dissolvido (COD), nitrogênio total (NT), nitrogênio total dissolvido (NTD), cor, pH e temperatura. A área de estudo foi a Lagoa Mangueira, uma grande lagoa rasa oligo-mesotrófica inserida ao Sistema Hidrológico do Taim – SHT. As amostras foram coletadas em quatro campanhas, durante o ano de 2010, em dezenove pontos diferentes, compreendendo as zonas litorâneas e pelágica, localizadas no sul, centro e norte da lagoa. Resultados indicaram que a Lagoa Mangueira apresenta heterogeneidade temporal interanual em relação a estas variáveis, ao mesmo tempo que possui um perfil longitudinal homogêneo, não evidenciando um arranjo espacial definido. / The present work evaluated spatial and temporal variability of humic acids (HA) and proteins (PROT) in a large subtropical shallow lake. For this purpose, High Performance Liquid Chromatograph by Size Exclusion (HPLC-SEC) was used. Dissolved organic carbon (DOC), total nitrogen (TN), total dissolved nitrogen (TDN), color, pH and temperature were included as explanatory variables. The study area was Mangueira lake, a large shallow oligo-mesotrophic lake located into the Taim Hydrological System. The samples were collected in four samplings during the year 2010 at nineteen different points, including the littoral and pelagic zones, located in the south, center and north of the lake. Results showed that the Mangueira lake presents interannual temporal heterogeneity in relation to these variables, at the same time that it has a homogeneous longitudinal profile, not evidencing a defined spatial arrangement.

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