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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.
211

Structure, Metamorphism and Stratigraphy of Allochthonous Units of the Southern Exmouth Antiform, Wopmay Orogen, Northwest Territories

Davies, Stephen D. 04 1900 (has links)
<p> The area of study is a small area of allochthonous rocks structurally located immediately above an Archean antiform in the Wopmay Orogen of the Northwest Territories. The rocks of the study area represent various units of the Akaitcho Group epicontinental rift fill deposits. All rocks are allochthonous, lying structurally above basement and autochthonous cover. </p> <p> Within the allochthonous rocks, three phases of deformation and a metamorphic culimnation are evident. The first episode (Dl) involved thrusting and folding of the allochthon over the Slave Craton, coinciding with peak metamorphic conditions. This phase of deformation was followed by an episode of coaxial, thick-skinned folding (D2), producing the large scale folds of basement and cover witnessed in the area. A late cross-folding event (D3), has provided up to 6 km of structural relief in the study area. The deformational history thus recorded in the Wopmay Orogen is similar to that documented in other orogenic belts such as the eastern Alps and Gape Smith Belt in Quebec. </p> <p> Metamorphism in the study area is hot side up Buchan type. A progression is observed in pelitic assemblages from muscovite-sillimanite grade to sillimanite-K feldspar grade, from east to west across the study area. A retrogression has produced sillimanite quartz pods (faserkiesel), its occurrence has permitted a relocation of the pre-existing prograde isograd. </p> <p> These finds are consistent with the current tectonic model for the area. </p> / Thesis / Bachelor of Science (BSc)
212

New Understanding of the Epidemiology of Rift Valley Fever Virus in Kenya

LaBeaud, Angelle Desiree 13 May 2009 (has links)
No description available.
213

COMPARATIVE STUDY OF CYANOBACTERIA OF DESERT AND SEMI-DESERT CRUSTS OF TWO DIFFERENT CONTINENTS: AFRICA (ETHIOPIA) AND NORTH AMERICA (USA)

Mesfin, Melaku 02 July 2009 (has links)
No description available.
214

MULTI-USER REDIRECTED WALKING AND RESETTING UTILIZING ARTIFICIAL POTENTIAL FIELDS

Hoffbauer, Cole 09 July 2018 (has links)
No description available.
215

New constraints on timing and kinematics of rifting at Cape Roberts Basin and Roberts Ridge from integrated seismic and core analysis of fault arrays

Trunkely, Zachary J. 06 January 2012 (has links)
No description available.
216

Virtual Reality as a Sales Tool for Industrial Companies

Sjöström, Elin January 2015 (has links)
To display large and complex products at sales meetings or fairs can be a challenge for industrial companies. Customers want to experience the product before purchase, yet this is not always possible due to high shipping costs and logistic problems. Virtual Reality (VR) achieved by Head-mounted Displays (HMD) is growing bigger by every day and is becoming accessible to more people. With this technology, there must be a new way to facilitate the sales process in the industry. The first goal with this master thesis was to investigate what challenges and opportunities there are in today’s sales process and develop a concept for a sales tool that uses the VR technology. The second goal was to explore how today’s technology could evolve and how the future sales process could work. To achieve these goals the Research Learning Spiral was used together with interviews and a workshop. By investigating how the sales process works in today’s industry, through interviews with people that are active in the field and a workshop, a number of challenges were identified. Three of these challenges were: to display large and complex products to the customers, to know what arguments that triggers a specific customer and to explain advantages with the product to the customer. Based on data from the interviews a prototype of a sales tool using VR was designed. The goal with the prototype was to counteract the challenges found in today’s sales process. The prototype uses a tablet where the salesman can control a 3D visualization of the product through a menu with different choices. This tablet is connected to the Samsung Gear VR, which is a VR device that uses a HMD to achieve VR, where the customer can experience the product in a virtual environment controlled by the salesman. With data from the interviews together with a conducted workshop, suggestions for the future sales process were obtained. The future sales process is very likely to use VR as a tool to both display products and to reduce traveling. The technology will possibly be smarter and be able to facilitate the sales process, for instance through artificial intelligence, smart materials and 3D printing. VR as a sales tool for large and complex products has the potential to be a great aid for the salesman during the sales process. Companies will not be required to ship large and complex products to fairs or meetings which will save money for the company and also contribute to less impact on the environment. This area of research is fairly new and there are a lot of opportunities still to be investigated.
217

Understanding Host-Pathogen Interactions of Rift Valley Fever Virus That Contribute to Viral Replication

Bracci, Nicole Rose 11 April 2022 (has links)
Rift Valley fever virus (RVFV) is a negative-sense RNA virus that is classified as an overlap select agent by the USDA and the HHS. It was first discovered in the Rift Valley of Kenya in the early 1930s. RVFV is an arbovirus that is transmitted by mosquitoes and infects ruminants and humans. RVFV in humans causes an acute self-limiting febrile illness but in a small percentage of cases, a severe version is noted by ocular disease, hepatitis, hemorrhagic fever, and death. In ruminants, the disease is similar with young livestock being the most susceptible. RVFV is also known to cause "abortion storms" where infected pregnant ruminants abort their fetuses with a near 100% fatality rate. Viruses are obligate intracellular parasites utilizing host-factors to replicate. This study identified three host-protein interactors of the viral Gn and L proteins that aid in viral replication. UBR4 was determined to be an interactor of Gn via immunoprecipitation followed by either LC/MS/MS or western blot analysis. Its inhibition via siRNA or CRISPR-Cas9 knockout showed a reduction of viral titers and viral RNA production. It was determined that UBR4 specifically affects viral RNA production and not entry or egress. Conversely, CK1α and PP1α were identified as binding partners of the L protein using similar methods. CK1α, a kinase, and PP1α, a phosphatase, were chosen for further verification due to data demonstrating the L protein is phosphorylated on at least one serine residue, in addition to PP1α already being shown to impact RVFV replication. Inhibition of CK1 and PP1 via small molecule inhibitors, D4476 and 1E7-03, respectively, showed a decrease in viral titers and RNA production. Strand-specific RT-qPCR demonstrates that CK1 and PP1 impact genomic replication. Upon treatment with D4476 a decrease in L protein phosphorylation was observed. Additionally, it has already been shown that treatment with 1E7-03 increases L protein phosphorylation. These data indicate that CK1 and PP1 modulate L protein phosphorylation, contributing to changes in RVFV replication. This study identifies three host-proteins that affect viral replication, which could be used as a foundation for host-based therapeutic and vaccine development. / Doctor of Philosophy / Rift Valley fever virus (RVFV) is a major biological threat due to its ability to infect both livestock and humans and be passed by mosquito bite. RVFV was first discovered in Africa in the early 1930s. To date, there is no approved therapeutic or vaccine. RVFV usually causes very mild disease but in a small percentage of cases, it progresses to include liver disease, vision loss, swelling of the brain, bleeding, and death. A virus itself is not alive; it needs a living host in order to replicate. To do this, it utilizes things naturally occurring inside the host. The purpose of this study is to identify host-factors that the virus uses in order to efficiently make more viruses. The first viral protein of interest is the glycoprotein, Gn, which is important for viral entry and assembly of the viral particles. It was determined that the host-protein UBR4 is an interactor of Gn and that the inhibition of UBR4 decreases the amount of infectious virus being produced. Similarly, the host-proteins, CK1α and PP1α, were found to be interactors of the viral L protein. The L protein is responsible for synthesizing the building blocks of the virus. It was determined that when CK1 and PP1 are inhibited, the L protein is less efficient at making these building blocks. Understanding the host-factors the virus utilizes is important to the basic understanding of how RVFV infects the host and the development of therapeutics to combat an outbreak.
218

Envisioning 3D learning environments in environmental education: an exploration of the Konza Prairie

Webb, Natalie January 1900 (has links)
Master of Landscape Architecture / Landscape Architecture/Regional and Community Planning / Howard D. Hahn / “There is an alarming gap between awareness and action on [environmental issues]” (Sheppard, 2005). Public awareness of how to cope and change with these issues is lacking (Sheppard, 2004; Nicholson-Cole, 2005; Dockerty et al., 2005), but new visualization technologies can begin to bridge the gap through environmental education. Environmental education focuses on the user exploring an environment, environmental issues, problem solving and ways to mitigate these issues. While the younger generations (middle to high school students) are much more aware of current and future environmental issues than older generations, the solutions to these problems may not be so apparent. By combining the need to educate young adults about climate change, regional ecosystem climate mitigation, and ecological management for technologically driven youth, middle and high school students can better understand their environment’s impact on climate-change regulation. Through literature synthesis, documentation of existing visualization exhibits and technologies, and preliminary technology exploration, a production process, criteria, framework, and technology recommendations were established. These components informed the final storyboards, which visually organized a proposal to build a 3D learning environment focused on the Konza Prairie and its ecological management practices.
219

Interaction tectonique-sédimentation dans le rift de Corinthe, Grèce. Architecture stratigraphique et sédimentologie du Gilbert-delta de Kerinitis.

Backert, Nicolas 28 May 2009 (has links) (PDF)
La stratigraphie synrift du bloc de faille est divisée en trois groupes stratigraphiques, représentant une épaisseur de 1624 m. Le Groupe inférieur est composé de sédiments fluvio-lacustres, le Groupe moyen comporte les Gilbert-deltas géants et leurs faciès fins associés, le Groupe supérieur est formé de Gilbert-deltas récents à actuels ainsi que de formations superficielles. La discordance basale de l'Unité du prérift présente une paléotopographie. La phase d'extension précoce (Groupe inférieur) est caractérisée par une très faible subsidence assurée par l'activité précoce de la faille de Pirgaki et des failles mineures. La transition avec la phase d'extension principale (Groupe moyen) est marquée par un approfondissement du bassin ainsi que par une augmentation du taux de subsidence. La phase d'abandon et de soulèvement du bloc (Groupe supérieur) est caractérisée par des évènements de creusement-comblement. Le Gilbert-delta géant de Kerinitis se serait déposé dans la période Pléistocène inférieur-Pléistocène moyen, en milieu marin. L'étude de la sédimentologie de faciès a permis de mettre en évidence quatre associations de faciès : topset, foreset, bottomset, prodelta. L'architecture stratigraphique est composée de onze Unités Stratigraphiques (SU) séparées par onze Surfaces Stratigraphiques (KSS). Dans un contexte de création continue d'espace d'accommodation, les SU se déposent pendant les maxima et les périodes de chute du niveau marin. Les KSS se mettent en place pendant des périodes d'augmentation du niveau marin. Les quatres étapes de construction du Gilbert-delta de Kerinitis ont enregistré le début, le maximum et l'arrêt de l'activité du système de failles.
220

Inversion conjointe des données magnétotelluriques et gravimétriques: Application à l'imagerie géophysique crustale et mantellique

Abdelfettah, Yassine 12 June 2009 (has links) (PDF)
Pour mieux comprendre les résultats géophysiques en termes de géologie, il est important d'utiliser différents types de données acquises par plusieurs méthodes. Une seule méthode géophysique n'a pas nécessairement la résolution suffisante pour expliquer la géologie. Avec une seule méthode, il peut être difficile de donner un sens géologique aux anomalies observées dans les modèles. L'inversion conjointe, en revanche, est une approche permettant de combiner des données de différentes natures. L'inversion conjointe peut être réalisée de deux façons : structurale ou pétrophysique. On peut subdiviser les inversions conjointes en deux groupes : l'inversion conjointe de méthodes sensibles au même paramètre physique comme les sondages électriques DC-DC et AC-DC, et l'inversion conjointe de méthodes sensibles aux paramètres de natures différentes, comme la gravimétrie et la sismique ou la sismique et la magnétotellurique (MT).Dans ce travail de thèse, je présente la solution de l'inversion conjointe de données MT et gravimétriques. La bonne résolution verticale mais la faible couverture spatiale des données MT peuvent être complémentaire des données gravimétriques qui possèdent une excellente couverture spatiale mais une faible résolution verticale.Le problème qui se pose dans l'inversion conjointe de données de différentes natures, est comment relier les différents paramètres. Des formules analytiques entre les vitesses sismiques et les densités ou entre les résistivités électriques et les densités sont destinées à des études spécifiques. En général, il n'est pas évident de relier les paramètres par des relations pétrophysiques. Par conséquent, il est nécessaire de développer des algorithmes qui n'imposent pas de relation spécifique entre les paramètres. L'approche d'inversion conjointe présentée ici est assez générale. Je pose une fonction de condition géométrique (GCF) sous laquelle les paramètres varient dans le même domaine pour imager les mêmes milieux.La méthodologie développée durant cette thèse est testée et validée sur des modèles synthétiques. Une application est réalisée sur les données réelles acquises dans la région de Turkana, Nord Kenya, une branche du Rift Est Africain. Les résultats obtenus ont permis de confirmer certaines conclusions apportées par les résultats de la sismique réflexion et d'apporter de nouvelles informations. L'étude a permis, en effet, de mettre en évidence deux Bassins en forme de demi-graben et de déterminer l'épaisseur des basaltes, jusque là inconnus. Une stratigraphie est proposée pour les bassins de Turkana et de Kachoda. Concernant l'étude de la lithosphère, nos résultats montrent une croûte très hétérogène et un manteau supérieur homogène. Deux anomalies (conductrices et moins denses) ont été mises en évidence entre la croûte inférieure.Ces anomalies peuvent être des zones de fusion partielle à priori sont déconnectées du manteau supérieur ou s'est initié la fusion.

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