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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.
41

Processo de combustão de solução aspergida (CSA) para a obtenção de eletrodos para SOFC

Tarragó, Diego Pereira January 2017 (has links)
A diminuição nos custos de fabricação das SOFC e também a flexibilização do combustível utilizado em seu abastecimento são obstáculos que, uma vez transpostos, podem possibilitar a utilização em larga escala das SOFC. A melhoria no desempenho dos componentes das SOFC pode fazer esse dispositivo trabalhar em temperaturas mais baixas, facilitando a operação do dispositivo e aumentando sua vida útil. Nesse sentido, é útil o desenvolvimento de métodos de fabricação simples e de baixo custo de componentes de SOFC, que atualmente são obtidos na forma de filmes finos cerâmicos. Assim, é proposto o desenvolvimento de uma nova técnica baseada na reação de combustão para síntese de pós e a aerografia, no intuito de, por via úmida, obter filmes finos porosos de composições cerâmicas. Foram realizadas deposições de manganitas de lantânio dopadas com estrôncio e cromo (LSM e LSCM) e óxido de cério dopado com lantânio (LCO) sobre substratos de zircônia estabilizada com ítria (YSZ) e de aço AISI 430, com o propósito de verificar a viabilidade do método de combustão de solução aspergida (CSA) proposto neste trabalho. Embora vários dos filmes fabricados tenham ficado descontínuos ou com uma quantidade excessiva de trincas, alguns resultados foram satisfatórios. Alguns filmes de LSM depositados sobre YSZ apresentaram tamanho de grão reduzido, da ordem de algumas dezenas de nanômetros, e uma porosidade fina e interconectada que levou o material a apresentar um bom desempenho eletroquímico, visando sua aplicação como cátodo de SOFC. A partir das suas propriedades eletroquímicas e, principalmente, pela energia de ativação dos processos do eletrodo, verificou-se que a microestrutura conferida pelo método de CSA proporcionou uma melhoria no desempenho da LSM. Os filmes de LSM obtidos nesse trabalho apresentaram energias de ativação inferiores a 1,26 eV, enquanto na literatura são encontrados valores mais altos para meia-células semelhantes. / Lowering fabrication costs of SOFC’s and also their fuel flexibility are obstacles that, once transposed, can make possible the mass utilization of such devices. The improvement on the performance of SOFC’s components can allow these devices to work in lower temperatures, facilitating their operation and increasing their lifespan. In this sense, is very useful the development of simple and cheap fabrication techniques of SOFC’s components, which are nowadays obtained in the form of thin ceramic films. Thus, the development of a new fabrication method is proposed, based on the solution combustion synthesis reaction and airbrush painting, in order to obtain, by a wet chemical route, thin and porous ceramic films. Depositions of strontium and cobalt doped lanthanum manganites (LSM and LSCM) and lanthanum doped cerium oxide (LCO) were carried out over yttria-stabilized zirconia (YSZ) and AISI 430 steel with the intent of verifying the viability of the Airbrushed Solution Combustion (ASC) method, proposed in this work. Although several films fabricated by ASC were discontinuous or excessively cracked, some results were satisfactory. Some LSM films deposited over YSZ showed reduced grain size, in the order of tens of nanometers, and a fine interconnected porosity, which led the material to present good electrochemical performance, aiming its application as a SOFC’s cathode. From their electrochemical properties and, mainly, through activation energy of the electrode processes, it was seeing that the microstructure acquired with the ASC method enhanced the overall performance of LSM. The LSM films obtained in this work showed activation energies below 1,26 eV, while in the literature the values are higher than this for similar half-cells.
42

Isolation and characterization of human adipose derived mesenchymal stem cells and production of GFP-labeled primary cells for in vivo tracking following transplantation

Van Vollenstee, Fiona A. January 2015 (has links)
Introduction It is well known that resident adipose stem/stromal cells (ASCs) are a heterogeneous population of multipotent cells characterized by (a) their ability to adhere to plastic; (b) immunophenotypic expression of certain cell surface markers, while lacking others; and (c) the capacity to differentiate into cells of mesodermal origin including osteocytes, chondrocytes and adipocytes. Adipose derived stromal cells offer great therapeutic potential in multiple medical fields, including, orthopedics, cardiology, oncology and degenerative diseases, to name a few. Combining different disciplines of medicine and engineering, organ and tissue repair can be achieved through tissue engineering and regenerative medicine. Adipose derived stromal cells (ASCs) can be utilized as biological vehicles for vector-based gene delivery systems, since they home to sites of inflammation and infection in vivo. In order to reach the long-term aim of clinical translation of cell-based therapy, preclinical safety and efficacy need to be shown in animal models. This has motivated the development of standardized isolation, characterization and differentiation operating procedures as well as an in vivo tracking system for ASCs and lentiviral vector transduction for a vector-based gene delivery system. Methodology Human ASCs were isolated from lipoaspirate, expanded in culture, immunophenotyped using flow cytometery and induced to differentiate into adipogenic, osteogenic and chondrogenic lineages. Tri-lineage differentiation was confirmed by microscopy. The ASCs were then transduced with green fluorescent protein (GFP)-expressing lentiviral vectors in vitro. The effect of the GFP lentiviral vector on ASCs was investigated by studying ASC immunophenotypic expression of surface markers as well as their capacity to differentiate into osteocytes, chondrocytes and adipocytes. Results The isolated and expanded cell population, from harvested lipoaspirate adhered to recommended ASC identity criteria. The heterogeneity of ASCs was confirmed by the presence of sub-populations. Transduction efficiency in ASC cultures of approximately 80% was observed after introducing a total of 300 μl of concentrated lentiviral vector suspension per 4.8 x 104 cells. No immunophenotypic differences were observed between GFP positive and GFP negative cultures. Flow cytometric analysis revealed a progressive increase in GFP expression following in vitro expansion of transduced ASCs. Both non-transduced and transduced cultures successfully differentiated into osteocytes, chondrocytes and adipocytes. Conclusion The isolated and expanded cell population conformed to the recommended characterization criteria. Heterogeneity was demonstrated with the identification of immunophenotypic sub-populations and semi-quantification of adipogenesis was performed. ASCs were efficiently transduced using the GFP lentiviral vectors produced in our facility. In addition, transduced ASCs maintained adherence to plastic, ASC immunophenotype and were able to differentiate successfully into cells of the three lineages of mesodermal origin. This optimized GFP-ASC transduction technique offers a feasible tracking system as well as a vector-based gene delivery system for future preclinical studies. / Dissertation (MSc)--University of Pretoria, 2015. / tm2015 / Immunology / MSc / Unrestricted
43

Intercorrelation between sound design, binaural and non-binaural audio systems : Effects on general vertical localization precision and reaction time in a non-visual directional choice task 3D game

Baker, David January 2022 (has links)
Spatialization of audio in the vertical plane has historically been limited. Instead, sound designers have used basic DSP to create pseudo height effects to explain the positions of corresponding objects. In recent years, binaural synthesis has become more widespread following an increase in the use of software rendering methods. With these advancements, uncertainty seems to be present around best practices when combining sound design with binaural synthesis for vertical placement of audio cues in games. This thesis compares the vertical localization performance between head related transfer functions (HRTFs) and stereo interaural level difference (ILD), when sounds have been designed with basic DSP to have auditory spatial schema (ASC). A sort of embedment of positional information. It was found that there was no significant time difference between the conditions, while hitcount, the number of correct directions selected, displayed a significant difference in some of the comparisons.
44

INFLAMMASOME DEPENDENT AND INDEPENDENT IL-1BETA PROCESSING BY NEUTROPHILS DURING BACTERIAL KERATITIS

Karmakar, Mausita 11 June 2014 (has links)
No description available.
45

Implementation of "Potty Party": An Errorless Learning Procedure in the School Setting to Toilet Train Children with Autism

Johnston, Julia M. 11 June 2015 (has links)
No description available.
46

Adeno-associated virus-VEGF-165 Mediated Modification of Adipose Derived Stem Cells for Cell Therapy

Niyogi, Upasana 25 August 2016 (has links)
No description available.
47

“CAIS GROUND SUPPORT EQUIPMENT USING A LOW COST, PC-BASED PLATFORM”

Knoebel, Robert, Berdugo, Albert 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The Common Airborne Instrumentation System (CAIS) was developed under the auspices of the Department of Defense to promote standardization, commonality, and interoperability among flight test instrumentation. The central characteristic of CAIS is a common suite of equipment used across service boundaries and in many airframe and weapon systems. The CAIS system has many advanced capabilities which must be tested during ground support and system test. There is a need for a common set of low cost, highly capable ground support hardware and software tools to facilitate these tasks. The ground support system should combine commonly available PC-based telemetry tools with unique devices needed for CAIS applications (such as CAIS Bus Emulator, CAIS Hardware Simulator, etc.). An integrated software suite is imperative to support this equipment. A CAIS Ground Support Unit (GSU) has been developed to promote these CAIS goals. This paper presents the capabilities and features of a PC-based CAIS GSU, emphasizing those features that are unique to CAIS. Hardware tools developed to provide CAIS Bus Emulation and CAIS Hardware Simulation are also described.
48

Understanding the Intersectoral Collaboration of Rural Community Health Workers and Teachers: The Example of Addressing Violence against Women and Girls in Vulindlela, South Africa

Karam, Jessie 06 1900 (has links)
Objectifs: Cette étude a documenté la collaboration intersectorielle entre les agents de santé communautaires (ASC) et les enseignants visant à combattre la violence à l’égard des femmes et des filles à Vulindlela, une communauté rurale Sud-Africaine. La collaboration entre ces acteurs, les facteurs qui influencent leur collaboration et les avenues possibles pour une amélioration de cette collaboration ont été explorés. Méthodes: Six ASC et cinq enseignants ont pris part à cette recherche participative qui a inclut l'utilisation du dessin comme méthodologie visuelle. La collecte de données a été réalisée en quatre phases, avec un total de huit entretiens de groupes. La stratégie d’analyse principale a inclus une approche dirigée du contenu narratif et une approche de comparaison constante. Résultats: Le système de collaboration entre les enseignants et les ASC manque de définition et ces acteurs ne peuvent donc en faire l’utilisation. Par conséquent la collaboration actuelle entre ces acteurs a été jugée peu développé, impromptue et informelle. De nombreuses contraintes à la collaboration ont été identifiées, y compris le manque de motivation de la part des enseignants, la nature des relations entre les acteurs, et la capacité individuelle limitée des ASC. Conclusion: Compte tenu des nombreuses contraintes à la collaboration entre ces ASC et les enseignants, il n'est pas évident que cette collaboration conduira aux résultats espérés. Dans l'absence de motivation suffisante et d’une prise de conscience réaliste des défis par les acteurs eux-mêmes, les initiatives externes pour améliorer la collaboration sont peu susceptibles de succès. / Objectives: This study had for objective to document intersectoral collaboration (ISC) between community health workers (CHWs) and teachers aimed at addressing violence against women and girls (VAW/G) in Vulindlela, a rural South African community. The current collaborative paths bringing CHWs and teachers together, the factors that influence their collaboration and potential avenues for future improvement of this collaborative were explored. Methods: A total of six CHWs and five teachers took part in this participatory research which included the use of drawing as a visual methodology. Data collection was divided into four phases and included a total of eight group interviews. The analysis of group interviews utilized a directed approach to narrative data analysis, and a constant comparative approach was used in the analysis of the participants` drawings. Results: There are no well-defined collaborative systems that CHWs and teachers are able to make use of. Consequently teacher-CHW collaboration was found to be poorly developed, unplanned and informal. Numerous barriers were identified as impeding collaboration including the teachers’ lack of motivation to collaborate, the nature of the relationships between these groups of actors and the CHWs’ overall lack of individual capacity. Conclusion: Given the numerous challenges facing collaboration between these CHWs and teacher, it is not clear that such collaboration would necessarily lead to effective outcomes. In the absence of sufficient motivation and a realistic awareness of the challenges from the actors themselves, external initiatives to foster collaboration are unlikely to be successful.
49

"Dis-lui qu'il n'existe pas". La propagation de la transe grisi siknis chez les Miskitos du Nicaragua / "Tell him he doesn't exist". The Propagation of Grisi siknis Hallucinatory Trance among the Miskitos of Nicaragua

Canna, Maddalena 29 September 2017 (has links)
Grisi Siknis est le calque miskito de l’anglais "crazy sickness". Au-dessous de cette étiquette opaque se cachent une série de crises de transe de masse se reproduisant depuis plus de cinquante ans dans la région de la Moskitia, entre le Nicaragua et le Honduras orientaux. La grisi siknis est un raptus de transe involontaire qui atteint de préférence les jeunes femmes miskitos, une ethnie afro-indigène de langue Misumalpa. Au cours de la transe, les attaqués de grisi siknis (lasa praprukra) tombent en proie à un comportement agressif et/ou auto-agressif associé à des hallucinations récurrentes, ce qui est généralement interprété comme l'attaque d'un esprit maléfique. La diffusion de la maladie est perçue par les affectés comme une épidémie contagieuse redoutable aux thérapies controversées. Néanmoins, le comportement des lasa praprukra présente un certain degré de ritualisation. L’objectif primaire de cette étude, qui s'est appuyée sur une année de recherches ethnographiques au Nicaragua, est de décrire la force de propagation de la grisi siknis, en analysant sa dynamique interactionnelle et la constitution de l'imaginaire qui l'impulse. L’imaginaire iconique lié aux hallucinations de la grisi siknis a été étudié en proposant aux attaqués de dessiner leurs contenus hallucinatoires. Cette pratique, en analogie avec certains traitement chamaniques locaux, a été appréhendée comme une forme de thérapie. Le corpus iconographique produit est analysé dans son double statut de représentation et d’imaginaire incarné doté d’agentivité. En deuxième lieu, la thèse décrit les soubassements neurocognitifs de la crise de transe en esquissant un modèle bayésien de l'induction d'hallucinations sans prise de psychotropes dans des sujets sains. Enfin, le statut social des attaqués de grisi siknis est comparé à ceux de spécialistes rituels tels que les chamanes et des guérisseurs. Une place importante est accordée à la nature ontologiquement instable des esprits impliqués et au rôle de la métacognition dans les modifications psycho-physiologiques qui en favorisent l’expérience et la croyance. / Grisi siknis is a Miskito calque of the English expression « crazy sickness ». Behind this secretive label lies a series of mass trance seizures that have been happening for more than fifty years in the Moskitia region, between Eastern Nicaragua and Honduras. Grisi siknis is an involuntary trance attack, mainly affecting young Miskito women, an afro-indigenous population whose language belongs to the Misumalpa family. During the trance, those attacked by grisi siknis (lasa praprukra) show an aggressive/auto-aggressive behaviour associated with repeated hallucinations, which is generally interpreted as the attack of an evil spirit. The spread of the disease is seen by those affected as a dangerous epidemic which therapies are still controversial. Nevertheless, the lasa praprukra behaviour presents a certain degree of ritualization. The main goal of this study, which relies on one year of ethnographic research in Nicaragua, is to describe grisi siknis propagation by analysing its interactional dynamics and the constitution of the imagery impulsing its spread. The iconic imagery of grisi siknis has been studied by proposing to patients to draw their hallucinatory contents. As it shares some analogies with local shamanic treatment, this practice has been apprehended as a form of therapy. The iconographic corpus of grisi siknis drawings is analysed both in representation and in agentive embodied imagery terms. Secondly, this thesis describes the neurocognitive processes behind the seizure by sketching a Bayesian model of the induction of hallucinations in healthy subjects without psychotropic intake.Finally, the social status of lasa praprukra is compared to those of some local ritual specialists as shamans and healers. An important place is accorded to the fluctuating ontology of the spirits mobilized during the trance, as well as to the role held by metacognition in the psycho-physiological modifications encouraging spirits experience and belief.
50

Altered expression of inflammasome components in inflammatory bowel disease

Forsskåhl, Sophia Katarina January 2019 (has links)
The inflammasome complex is a multiprotein complex that may play a role in the pathogenesis of inflammatory bowel disease (IBD) by secreting the inflammatory cytokines interleukin (IL)-1β and IL-18, and inducing pyroptosis, as a response to signals through several inflammasome sensors. This study looked at the expression of several inflammasome components in the ileum and colon of patients suffering from IBD. The inflammasome sensors NLRP1, NLRP3, AIM2 and pyrin were upregulated in whole intestinal tissue of IBD patients, particularly in the colon. NLRP6 expression was increased in the colon of Crohn's disease patients, but not ulcerative colitis patients relative to colon of controls, and was reduced in the ileum of Crohn's disease patients compared to control ileum. Expression of caspase-1 and IL-1β, but not IL-18, were also increased in ileum and colon tissue from Crohn's patients. To identify the cell type where inflammasome expression was altered in Crohn’s disease, transcription of inflammasome subunits in intestinal tissue enriched for epithelial cells or lamina propria (LP) cells was analysed. These analyses indicated that LP cells have greater expression of the inflammasome sensors NLRP1, NLRP3, AIM2 and pyrin relative to epithelial cells, both during disease and in control tissue. Moreover, LP cells from Crohn’s patients have higher expression level of NLRP1, AIM2 and pyrin than LP cells from controls. In contrast the inflammasome sensor NLRP6 was more highly expressed by epithelial cells relative to LP cells in general, and NLRP6 expression in LP cells from IBD patients was lower than that observed in LP cells from controls. The observed differential expression of inflammasome components in controls versus IBD intestine and in different cellular fractions of intestinal tissue highlight the importance of understanding the role of the inflammasome in IBD and hints at the possibility of targeting the inflammasome pathway as a future treatment strategy.

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