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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.
201

Análise tectono-estratigráfica das formações itaparica e água grande (Bacia do Recôncavo, Bahia)

Wiederkehr, Fabiane January 2010 (has links)
Com base em afloramentos da borda oeste da Bacia do Recôncavo foi efetuada uma análise estratigráfica do intervalo entre as formações Itaparica e Água Grande. Os resultados obtidos foram correlacionados com poços na confecção de seções geológicas no sentido dip e de mapas de espessuras para o intervalo total, arenito e pelito. Os dados de campo mostram os pelitos lacustres da Formação Itaparica sendo sucedidos por um sistema deltaico, que dá lugar a arenitos fluviais e eólicos da Formação Água Grande. Portanto, o perfil composto é caracterizado por uma sucessão progradacional, associada a uma progressiva diminuição da razão da taxa de subida do nível freático versus a taxa de influxo sedimentar. A seção de correlação com poços revela um espessamento do intervalo em direção ao depocentro da bacia. Os mapas gerados apresentam, também, boa relação com os compartimentos estruturais da bacia, além de corroborar com a progradação de um sistema siliciclástico de norte sobre um sistema lacustre a sul. Estes resultados revelam que as unidades estudadas foram depositadas sob controle da geometria do meio-gráben do Recôncavo, nos seus estágios iniciais de formação. / A stratigraphical analysis was performed on the Itaparica and Água Grande formations interval, based on outcrops of the western margin of Recôncavo Basin. The obtained results were correlated with boreholes for dip geologic sections and for isopach and isolith maps generation. The field data shows the Itaparica Formation lacustrine mudstones being succeeded by a deltaic system, which make way for the Água Grande Formation fluvio-eolian sandstones. Then, the composite profile is characterized by a progradational pattern and a drying upwards cycle. The geologic section with field and borehole data reveals the thickening of the interval towards the basin depocenter. Also the generated maps present good correlation with the basin‟s compartments, besides corroborating the progradation of a siliciclastic system coming from north to a lacustrine system at south. So, these results demonstrate that the studied units were deposited under the control of the Recôncavo‟s half-graben geometry, in its initial stages of evolution.
202

Petrografia e geoquímica dos ortoanfibolitos das unidades Novo Gosto e Gentileza, Domínio Canindé, Faixa de Dobramentos Sergipana, NE-Brasil

Liz, Leidiane Cerqueira de Carvalho de 05 May 2017 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the Canindé Domain, Northern portion of Sergipano Fold Belt, NE-Brazil, occur an association of metamorfized mafic igneous rocks from the Novo Gosto and Gentileza units.Those rocks represent important pieces in the Sergipano Fold Belt geological evolution. The Canindé Domain has been scenario of several interpretations about the tectonic and petrogenetic settings, due to intense deformation and metamorphism that obliterated much of the Canindé Domain rocks original features. Petrographic and geochemical data from the ortho-amphibolites of the Novo Gosto and Gentileza units showed this work contribute to discuss the igneous processes involved in the protoliths genesis, therefore building up to the Canindé Domain tectonic model definition and the major evolutionary aspects. The petrographic data indicate that the studied rocks show Amphibolite Facies paragenesis, marked by hornblende and plagioclase, with retrometamorphic transformations to Greenschist Facies, defined by biotite, epidote, chlorite and sericite paragenesis. These transformations, which were more intense in areas with shear zones concentrations, are probably, the result of hydrothermal fluid action. In spite of the superimposed metamorphic processes, it was possible to observe igneous relicts features, such as blast-glomeroporphiritic, blast- intergranular and blast-subophytic textures. The chemical data suggest that the protoliths of the studied rocks of the Novo Gosto and Gentileza units correspond to basalts with tholeiitic affinity. These basalts are divided into high-Ti (> 2 % TiO 2 ) and low-Ti (< 1,19 % TiO 2 ). Gentileza Unit rocks correspond to andesites and basaltic andesites with tholeiitic to calc- alkaline affinity. The geochemical data interpretation suggest that the igneous protoliths of the studied rocks of the Novo Gosto and Gentileza units were formed in a continental rift environment, derived from magmas generated in different proportions of mixtures between enriched and depleted reservoirs, with OIB-type components contribution. Ratios and correlations among incompatible elements indicate crustal contamination participation in the igneous protoliths generation of both units. / No Domínio Canindé, porção norte da Faixa de Dobramentos Sergipana, NE-Brasil, ocorrem rochas ígneas máficas metamorfizadas das unidades Novo Gosto e Gentileza. Estas rochas representam peças importantes na evolução geológica da faixa. O Domínio Canindé foi palco de diversas interpretações quanto ao ambiente geotectônico e petrogenético, devido à intensa deformação e metamorfismo, que obliteraram boa parte das feições originais das rochas do domínio. Neste trabalho são apresentados e discutidos dados petrográficos e geoquímicos dos ortoanfibolitos das unidades Novo Gosto e Gentileza, com o intuito de discorrer sobre os processos ígneos envolvidos na gênese dos protólitos, de forma a contribuir com a definição do ambiente tectônico de formação e dos principais aspectos evolutivos do Domínio Canindé. Os dados petrográficos indicam que as rochas estudadas possuem uma paragênese estabelecida no Fácies Anfibolito, marcada por hornblenda e plagioclásio, com transformações retrometamórficas para o Fácies Xisto Verde, definidas por biotita, epídoto, clorita e sericita. Essas transformações, que são mais intensas em áreas com concentrações de zonas de cisalhamento, são possivelmente o resultado da ação de fluidos hidrotermais. Apesar dos processos metamórficos superimpostos, foi possível observar feições ígneas reliquiares, marcadas por texturas blasto-glomeroporfirítica, blasto-intergranular e blasto-subofítica. Os dados químicos indicam, que os protólitos das rochas estudadas da Unidade Novo Gosto, correspondem à basaltos de afinidade toleítica, que podem ser divididos em alto-Ti (> 2% TiO 2 ) e baixo-Ti (< 1,19% TiO 2 ). As rochas da Unidade Gentileza correspondem, em sua maioria, à andesitos e andesitos basálticos de afinidade toleítica a cálcio-alcalina. A interpretação dos dados geoquímicos sugere que os protólitos ígneos das rochas estudadas foram formados em um ambiente de rifte continental, derivados de magmas gerados a partir de diferentes proporções de misturas entre reservatórios enriquecidos e empobrecidos, com contribuição de componentes tipo-OIB. Razões e correlações entre elementos incompatíveis sugerem a participação de contaminação crustal na geração dos protólitos ígneos das duas unidades.
203

Structural studies of bunyavirus interferon antagonist proteins

Barski, Michał S. January 2016 (has links)
Bunyaviridae is one of the biggest known viral families, and includes many viruses of clinical and economic importance. The major virulence factor of most bunyaviruses is the non-structural protein (NSs). NSs is expressed early in infection and inhibits the innate immune response of the host by blocking several steps in the interferon induction and signalling pathways. Hence, NSs significantly contributes to the establishment of a successful viral infection and replication, persistent infection and the zoonotic capacity of bunyaviruses. Although functions and structures of many viral interferon antagonists are known, no structure of a bunyavirus NSs protein has been solved to date. This strongly limits our understanding of the role and the mechanism of interferon antagonism in this large virus family. In this work the first structure for a bunyavirus interferon antagonist, the core domain crystal structure of NSs from the Rift Valley fever virus (RVFV) is presented. RVFV is one of the most clinically significant members of the Bunyaviridae family, causing recurrent epidemics in Africa and Arabia, often featuring high-mortality haemorrhagic fevers. The structure shows a novel all-helical fold. The unique molecular packing of NSs in the crystal creates stable fibrillar networks, which could correspond to the characteristic fibrillation of NSs observed in vivo in the nuclei of RVFV infected cells. This first NSs structure might be a useful template for future structure-aided design of drugs that target the RVFV interferon antagonism. Attempts at characterising other bunyavirus NSs proteins of other genera were made, but were hampered by problems with obtaining sufficient amounts of soluble and folded protein. The approaches that proved unsuccessful for the solubilisation of these NSs proteins, however, should inform future experiments aimed at obtaining recombinant NSs for structural studies.
204

A retrospective analysis of the epidemiology of Rift Valley fever in South Africa

Pienaar, N.J. (Nicolaas Johannes) 09 November 2011 (has links)
The aim of this study was to investigate the epidemiology of Rift Valley fever (RVF) in South Africa. The first part of the study consisted of the compilation of a full history of RVF in South Africa. This was done by compiling all references to outbreaks of the disease in South Africa from all available literature, annual reports, disease reports and animal disease databases. The geographic location and temporal occurrence of each outbreak was recorded as accurately as allowed by the available records. The result was a better and more complete picture than has hitherto been available of the spatial and temporal distribution of RVF for the period 1950, when the disease was first recognised in South Africa, to 2010. Several smaller outbreaks not mentioned in the literature were found. It emerged that large outbreaks occur in the Free State Province, Eastern Cape Province and Northern Cape Province with long periods of absence and smaller outbreaks occur in KwaZulu-Natal, Mpumalanga and Gauteng at more frequent intervals.The second part of the study used the data collected during the first part of the study to determine which climatic and other environmental factors could have played a role in the occurrence of RVF in South Africa. Multiple logistic regression analysis was used to estimate associations between the various potential risk factors and the occurrence of Rift Valley fever.The study found that the El Niño/Southern Oscillation influence on rainfall in South Africa has an effect on the occurrence of RVF in South Africa which is opposite to the effect that has been described for Kenya. A positive Southern Oscillation Index (La Niña) increases the likelihood of a RVF outbreak in South Africa.The study also found that very high rainfall during the summer months (December to February) is an important risk factor for the occurrence of RVF and it confirmed the increased risk of an outbreak where pans and wetlands are present as reported in several articles and disease reports on past outbreaks. Several other factors, such as minimum and maximum temperature were also found to have a statistically significant effect on the occurrence of Rift Valley fever. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Production Animal Studies / unrestricted
205

The genesis of ‘giant’ copper-zinc-gold-silver volcanogenic massive sulphide deposits at Tambogrande, Perú : age, tectonic setting, paleomorphology, lithogeochemistry, and radiogenic isotopes

Winter, Lawrence Stephen 11 1900 (has links)
The ‘giant’ Tambogrande volcanogenic massive sulphide (VMS) deposits within the Cretaceous Lancones basin of northwestern Perú are some of the largest Cu-Zn-Au-Ag-bearing massive sulphide deposits known. Limited research has been done on these deposits, hence the ore forming setting in which they developed and the key criteria that permitted such anomalous accumulation of base-metal sulphides are not understood. Based on field relationships in the host volcanic rocks and U-Pb geochronology, the deposits formed during the early stages of arc development in the latest Early Cretaceous and were related to an extensional and arc-rift phase (~105-100 Ma, phase 1). During this time, bimodal, primitive basalt-dominant volcanic rocks were erupted in a relatively deep marginal basin. Phase 1 rhyolite is tholeiitic, M-type, and considered to have formed from relatively high temperature, small batch magmas. The high heat flow and extensional setting extant during the initial stages of arc development were essential components for forming a VMS hydrothermal system. The subsequent phase 2 (~99-91 Ma) volcanic sequence comprises more evolved mafic rocks and similar, but more depleted, felsic rocks erupted in a relatively shallow marine setting. Phase 2 is interpreted to represent late-stage arc volcanism during a waning extensional regime and marked the transition to contractional tectonism. The Tambogrande deposits are particularly unusual amongst the ‘giant’ class of VMS deposits in that deposition largely occurred as seafloor mound-type and not by replacement of existing strata. Paleomorphology of the local depositional setting was defined by seafloor depressions controlled by syn-volcanic faults and rhyolitic volcanism. The depressions were the main controls on distribution and geometry of the deposits and, due to inherently confined hydrothermal venting, enhanced the efficiency of sulphide deposition. Geochemical and radiogenic isotope data indicate that the rhyolites in the VMS deposits were high temperature partial melts of the juvenile arc crust that had inherited the isotopic signatures of continental crust. Moreover, Pb isotope data suggest the metal budget was sourced almost wholly from mafic volcanic strata. Therefore, unlike the implications of many conventional models, the felsic volcanic rocks at Tambogrande are interpreted to have only played a passive role in VMS formation. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
206

Architecture of the Silurian sedimentary cover sequence in the Cadia porphyry Au-Cu district, NSW, Australia : implications for post-mineral deformation

Washburn, Malissa 11 1900 (has links)
Alkalic porphyry style Au-Cu deposits of the Cadia district are associated with Late-Ordovician monzonite intrusions, which were emplaced during the final phase of Macquarie Arc magmatism at the end of the Benambran Orogeny. N-striking faults, including the curviplanar, northerly striking, moderately west-dipping basement thrust faults of the Cadiangullong system, developed early in the district history. NE-striking faults formed during rifting in the late Silurian. Subsequent E-W directed Siluro- Devonian extension followed by regional E-W shortening during the Devonian Tabberabberan Orogeny dismembered these intrusions, thereby superposing different levels porphyry Au-Cu systems as well as the host stratigraphy. During the late Silurian, the partially exhumed porphyry systems were buried beneath the Waugoola Group sedimentary cover sequence, which is generally preserved in the footwall of the Cadiangullong thrust fault system. The Waugoola Group is a typical rift-sag sequence, deposited initially in local fault-bounded basins which then transitioned to a gradually shallowing marine environment as local topography was overwhelmed. Basin geometry was controlled by pre-existing basement structures, which were subsequently inverted during the Devonian Tabberabberan Orogeny, offsetting the unconformity by up to 300m vertically. In the Waugoola Group cover, this shortening was accommodated via a complex network of minor detachments that strike parallel to major underlying basement faults. For this reason, faults and folds measured at the surface in the sedimentary cover can be used as a predictive tool to infer basement structures at depth. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
207

Virtual Reality's Effect on Engagement in Educational Games

Rödström, Herman, Fredriksson, Pontus January 2017 (has links)
This thesis explores how virtual reality solutions affect children in their learning through educational games. The goal is to improve educational games in terms of how engaging they are. Therefore, a game was developed for both desktop monitors and VR, some children played both versions and were then interviewed. The collected data indicates that VR engages the pupils more, however it does not seem to necessarily make them learn more. This may be in part because of VR’s novelty, only gaining a mainstream status in the recent years. / Denna uppsats undersöker hur virtuell verklighet (VR) påverkar barns lärande genom utbildningsspel. Målet är att förbättra utbildningsspel för att öka elevernas engagemang. Därför utvecklades ett spel för både datorskärmar och VR-glasögon, några barn fick spela båda versionerna och blev därefter intervjuade. Resultatet av undersökningen indikerar att VR ökar elevernas engagemang, men inte nödvändigtvis att de lär sig mer. Detta kan delvis bero på att VR är relativt nytt och endast börjat bli allmänt förekommande under de senaste åren.
208

Zařízení pro interakci v rozšířené realitě / Interaction Device for Augmented Reality

Pavlenko, Peter January 2017 (has links)
This master thesis explores interactive augmented reality. The aim is to design, create andtest device, which allows interaction between user and augmented reality. First analyzesaugmented reality, devices for its displaying and necessary calibration methods. Then, onthe basis of acquired knowledge, shows design and construction of few prototypes of devicelike this. Finally it shows experiments to test correctness of the concept.
209

Système d'information décisionnel sur les interactions environnement-santé : cas de la Fièvre de la Vallée du Rift au Ferlo (Sénégal) / Decision-making system on environment and health interactions : case of the Rift Valley Fever in Ferlo (Senegal)

Bouba, Fanta 25 September 2015 (has links)
Notre recherche se situe dans le cadre du projet QWECI (Quantifying Weather and Climate Impacts on Health in Developing Countries, UE FP7) en partenariat avec l’UCAD, le CSE et l’IPD, autour de la thématique environnement-santé avec comme cas pratique les maladies à vecteurs au Sénégal et plus particulièrement la Fièvre de la Vallée du Rift (FVR). La santé des populations humaines et animales est souvent fortement influencée par l’environnement. D’ailleurs, la recherche sur les facteurs de propagation des maladies à transmission vectorielle, telle que la FVR, prend en compte cette problématique dans sa dimension aussi bien physique que socio-économique. Apparue en 1912-1913 au Kenya, la FVR est une anthropo-zoonose virale répandue dans les régions tropicales qui concerne principalement les animaux mais dont les hommes peuvent aussi être touchés. Au Sénégal, la zone à risque concerne en majorité la vallée du fleuve Sénégal et la zone sylvo-pastorale du Ferlo. Bien que de climat sahélien, le Ferlo regorge de nombreuses mares qui sont des sources d’approvisionnement en eau pour les hommes et le bétail mais également les gîtes larvaires pour les vecteurs potentiels de la FVR. La maîtrise de la FVR, carrefour de trois (03) grands systèmes (agro-écologique, pathogène, économique/sanitaire/social), implique nécessairement la prise en compte de plusieurs paramètres si l’on veut d’abord comprendre les mécanismes d’émergence mais aussi envisager le travail de modélisation du risque. Notre travail porte sur le processus décisionnel pour quantifier l’utilisation de données sanitaires et environnementales dans l’évaluation de leur impact pour le suivi de la FVR. Les équipes de recherche impliquées produisent des données lors de leurs enquêtes de terrains et des analyses de laboratoire. Ce flot de données croissant devrait être stocké et préparé à des études corrélées grâce aux nouvelles techniques de stockage que sont les entrepôts de données. A propos de l’analyse des données, il ne suffit pas de s’appuyer seulement sur les techniques classiques telles que les statistiques. En effet, la valeur ajoutée de contribution sur la question s’oriente vers une analyse prédictive combinant à la fois les techniques agrégées de stockage et des outils de traitement. Ainsi, pour la découverte d’informations, nouvelles et pertinentes à priori non évidentes, il est nécessaire de s’orienter vers la fouille de données. Par ailleurs, l’évolution de la maladie étant fortement liée à la dynamique spatio-temporelle environnementale des différents acteurs (vecteurs, virus et hôtes), cause pour laquelle nous nous appuyons sur les motifs spatio-temporels pour identifier et mesurer certaines interactions entre les paramètres environnementaux et les acteurs impliqués. Grâce au processus décisionnel, les résultats qui en découlent sont multiples :i. suivant la formalisation de la modélisation multidimensionnelle, nous avons construit un entrepôt de données intégré qui regroupe l’ensemble des objets qui participent à la gestion du risque sanitaire – ce modèle peut être généralisé aux maladies à vecteurs ;ii. malgré une très grande variété de moustiques, les Culex de type neavei et les Aedes de type ochraceus et vexans sont les vecteurs potentiels de la FVR les plus présents dans la zone d’étude et ce, durant la saison des pluies, période la plus sujette à des cas suspects ; la période à risque reste quand même le mois d’octobre ;iii. les mares analysées ont quasiment le même comportement, mais des variations significatives subsistent par endroits.Ce travail de recherche démontre une fois de plus l’intérêt pour la mise en évidence des relations entre les données environnementales et la FVR à partir de méthodes de fouille de données, pour la surveillance spatio-temporelle du risque d’émergence. / Our research is in part of the QWeCI european project (Quantifying Weather and Climate Impacts on Health in Developing Countries, EU FP7) in partnership with UCAD, the CSE and the IPD, around the theme of environmental health with the practical case on vector-borne diseases in Senegal and particularly the Valley Fever (RVF). The health of human and animal populations is often strongly influenced by the environment. Moreover, research on spread factors of vector-borne diseases such as RVF, considers this issue in its dimension both physical and socio-economic. Appeared in 1912-1913 in Kenya, RVF is a widespread viral anthropo-zoonosis in tropical regions which concerns animals but men can also be affected. In Senegal, the risk area concerns mainly the Senegal River Valley and the forestry-pastoral areas Ferlo. With a Sahelian climate, the Ferlo has several ponds that are sources of water supply for humans and livestock but also breeding sites for potential vectors of RVF. The controlling of the RVF, which is crossroads of three (03) large systems (agro-ecological, pathogen, economic/health/social), necessarily entails consideration of several parameters if one wants to first understand the mechanisms emergence but also consider the work on risk modeling. Our work focuses on the decision making process for quantify the use of health data and environmental data in the impact assessment for the monitoring of RVF. Research teams involved produce data during their investigations periods and laboratory analyzes. The growing flood of data should be stored and prepared for correlated studies with new storage techniques such as datawarehouses. About the data analysis, it is not enough to rely only on conventional techniques such as statistics. Indeed, the contribution on the issue is moving towards a predictive analysis combining both aggregate storage techniques and processing tools. Thus, to discover information, it is necessary to move towards datamining. Furthermore, the evolution of the disease is strongly linked to environmental spatio-temporal dynamics of different actors (vectors, viruses, and hosts), cause for which we rely on spatio-temporal patterns to identify and measure interactions between environmental parameters and the actors involved. With the decision-making process, we have obtained many results :i. following the formalization of multidimensional modeling, we have built an integrated datawarehouse that includes all the objects that are involved in managing the health risk - this model can be generalized to others vector-borne diseases;ii. despite a very wide variety of mosquitoes, Culex neavei, Aedes ochraceus and Aedes vexans are potential vectors of FVR. They are most present in the study area and, during the rainy season period which is most prone to suspected cases; the risk period still remains the month of October;iii. the analyzed ponds have almost the same behavior, but significant variations exist in some points.This research shows once again the interest in the discovery of relationships between environmental data and the FVR with datamining methods for the spatio-temporal monitoring of the risk of emergence.
210

Exploring violence through the narratives of youth in Kenyan secondary schools: Implications for reconceptualising peacebuilding

Wachira, T.W. January 2012 (has links)
Based on the narratives of young people this research explores the rise in youth violence in Kenya¿s secondary school system and wider society and the potential for peacebuilding to address youth violence. Of particular concern is the gradual change in the profiles, patterns and intensity of the conflict, as evidenced by the increase in the number of youth militias. This increase is often attributed to unemployment and poverty ¿ yet, to date, no systematic research has been produced on the extent to which the youth participation in violence occurs through choice or coercion, or indeed both. Worryingly, a significant number of young people involved in this violence are secondary school students. The findings of this research indicate that despite responses to youth violence in the school and wider Kenyan society, the violence is unabated. Notably, approaches continue to be top-down, generic, superficial and ineffectual. By marginalising the narratives of the youth who participate in and/or observe the violence, current institutional policies and approaches are decontextualised - from both the particular and the wider Kenyan context. This leaves intact the root causes of the violence. This research raises important questions concerning generic, top-down, quick-fix, outmoded cultural paradigms, hierarchical and questionable homogeneous pedagogical approaches to peacebuilding in both the schools and wider Kenyan context. In attempt to address these deficiencies the research seeks to find out approaches to peacebuilding and the Kenyan education systems that can respond to youth violence. This research proffers three key dimensions that can be incorporated in order to ensure effective and sustainable peace: experiences, worldviews and attitudes of the actors. The research, which utilises a constructivist grounded theory approach (Charmaz, 2006), was conducted in fourteen secondary schools in Nairobi and the Rift Valley provinces ¿ two provinces that have been at the centre of youth violence and militia activities. These provinces were also selected in order to reflect the multi-cultural and multi-ethnic character, and the different types of schools in Kenya.

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