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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.
261

Singularities of two-point functions in Quantum Field Theory

Wrochna, Michal 16 August 2013 (has links)
No description available.
262

Parent involvement in early childhood development in Kwazulu Natal

Bridgemohan, Radhika Rani 01 January 2002 (has links)
This study on parent involvement in Early Childhood Development in KwaZulu Natal investigates the experiences of educators and parents of the different types of parent and community involvement as set out in the Epstein typology. In order to investigate this phenomenon a thorough background of the theory and practice of the Epstein model has been provided. In addition the work of other researchers that support the Epstein typology of parent involvement forms an integral part of the discussions. As parent involvement is the key focus of the study, parent involvement in education before and after 1994 are discussed. In this regard relevant educational policy and legislation that are designed to increase the role of parents and the community in Early Childhood Development are highlighted. Parents' role in the provision of Early Childhood Development is explored. The provision of Early Childhood Development in KwaZulu Natal, which provides a backdrop for the investigation, is exptained. In addition contextual factors that influence parent involvement in KwaZulu Natal are provided. The research methodology and the research design used in this study are described in detail. By means of a qualitative approach the experiences of a small sample of educators and parents in Early Childhood Development are explored using the six types of parent involvement that include parenting, communicating, volunteering, learning at home and collaborating with the community as set out in Epstein's comprehensive model. The experiences of educators and parents of Grade R learners of the six types of involvement have been included. Although all schools engage in some form of parent involvement, it is evident that not all schools involve parents in all types of parent involvement to the same extent. The study concludes with recommendations for developing strategies to involve parents more effectively in Early Childhood Development in KwaZulu Natal
263

Etude fonctionnelle de l'Ubinucléine, partenaire cellulaire du facteur de transcription EB1 du virus d'Epstein-Barr et inhibition du cycle lytique viral

Conti, Audrey 14 December 2012 (has links) (PDF)
Découvert en 1964, le virus d'Epstein-Barr appartient à la famille des gamma-herpèsvirus. Ce virus à ADN présente une forte prévalence (90% de la population adulte est infectée). Ce fut le premier virus identifié comme associé à des cancers (lymphome de Burkitt et d'Hodgkin, carcinome gastrique et de l'oropharynx). Ce virus a pour spécificité de posséder deux cycles distincts : latent et lytique (production de particules virales). Le facteur de transcription viral EB1 (ou Zebra) est un élément clé lors de l'initiation du cycle lytique et semble une cible importante pour l'élaboration de nouveaux traitements. Une première partie de ce travail concerne la caractérisation d'une protéine cellulaire (l'Ubinucléine) qui interagit et inhibe l'activité de EB1. Cette protéine voyage entre noyaux et jonctions serrées. Elle appartient à la famille des " NACos " (nuclear and adhesion complex components). La fonction de l'Ubinucléine n'est pas connue et sa protéomique quand elle est localisée dans les jonctions serrées, a été réalisée. Des études fonctionnelles montrent que l'Ubinucléine interagit avec plusieurs partenaires cellulaires, emprunte la voie d'endocytose dépendante de la clathrine et que sa localisation cellulaire (nucléaire ou dans les jonctions serrées) est affectée par la PKA. Dans une seconde partie, nous nous sommes intéressés à des molécules inhibitrices du facteur de transcription viral EB1. Après criblage à haut débit de composés chimiques (EMBL-Heidelberg), des tests in-vitro ont permis d'en sélectionner un pour des essais in-vivo. Ce composé chimique inhibe l'activité du facteur de transcription EB1 et bloque précocement la mise en place du cycle lytique dans des cellules de lymphome de Burkitt. Il semble donc intéressant d'améliorer l'efficacité et la spécificité de cette molécule.
264

Etudes fonctionnelles et structurales des complexes Hélicase-Primase du virus Epstein-Barr

Thierry, Eric 23 April 2013 (has links) (PDF)
Le virus Epstein-Barr (EBV) est un gamma herpèsvirus humain infectant plus de 95 % de la population mondiale. Lorsque la primo-infection a lieu pendant l'adolescence ou à l'âge adulte, elle peut induire la mononucléose infectieuse (MNI), cette maladie est le plus souvent bénigne. EBV est aussi associé à un certain nombre de cancers de type lymphome (lymphomes de Burkitt et d'Hodgkin) et de type carcinome (carcinomes gastriques et indifférenciés du rhinopharynx). L'importance des protéines de latence du virus dans l'apparition des tumeurs a été très étudiée. Des études récentes montrent que les protéines lytiques d'EBV sont aussi très importantes pour l'apparition et le développement des tumeurs. Le complexe Hélicase-Primase (H-P) du virus herpès simplex 1 (HSV-1, alpha herpèsvirus) est la cible de nouveaux antiviraux. Les activités ATPase, hélicase et primase du complexe d'HSV-1 ont été largement étudiées, mais aucune information structurale du complexe H-P n'est disponible actuellement pour un membre des herpèsvirus humains. Nous avons entrepris l'étude du complexe H-P d'EBV (BBLF4 : hélicase, BSLF1 : primase et BBLF2/3 : sous-unité accessoire) afin de caractériser sa structure et les activités qu'il porte. Nous avons pu établir les conditions d'expression et de purification du complexe et débuter des études structurales et enzymatiques préliminaires. Nous avons pu observer une activité ATPase basale du complexe indépendante de la présence d'un substrat ADN simple brin. Nous observons deux formes solubles du complexe lors des purifications, une présentant probablement une stœchiométrie proche de 1/1/1 et une seconde forme ayant surement un excès de la protéine Hélicase (BBLF4). Ces premiers résultats apportent des informations nouvelles pour le complexe H-P d'EBV et doivent être poursuivis afin de les confirmer et de pouvoir les comparer avec ceux déjà connus pour le complexe H-P d'HSV-1.
265

Posttransplant Lymphoproliferative Disorders : Studies of Epstein-Barr Virus, Regulatory T Cells and Tumor Origin

Kinch, Amelie January 2014 (has links)
Epstein-Barr virus (EBV) infects almost all humans and establishes lifelong latency in B cells. Posttransplant lymphoproliferative disorder (PTLD) is a rare but serious complication after transplantation triggered by immunosuppression and often related to EBV infection. The aim of this thesis was to study the role of EBV in relation to clinical and histological features of PTLD, regulatory T cells (Tregs), and donor or recipient origin of PTLD. EBV surveillance after allogeneic hematopoietic stem cell transplantation (allo-HSCT) showed that EBV reactivations were common, but that symptomatic EBV disease (including PTLD) only occurred in the high-risk group (unrelated or mismatched related grafts, reduced-intensity conditioning). A threshold of 1000 copies/ml plasma distinguished EBV disease from asymptomatic reactivations. In a population-based cohort of 135 PTLDs/lymphomas after solid organ transplantation (SOT) almost half were EBV–. EBV+ PTLDs were associated with B cell phenotype, non-germinal center subtype of diffuse large B cell lymphoma (DLBCL), early-onset, graft involvement, antithymocyte globulin treatment, and younger age. EBV– PTLDs were associated with T cell phenotype, bone marrow involvement, and hepatitis C. Most PTLDs displayed few or no intratumoral Tregs with the marker FoxP3, possibly due to heavy immuno­suppres­sion. Half of both FoxP3+ and FoxP3– PTLDs were EBV+. FoxP3+ PTLDs were associated with B cell phenotype and hepatitis C. All PTLDs for which tumor origin could be determined were recipient-derived and half of them were EBV+. Eight of twelve recipient-derived graft PTLDs were disseminated outside the graft. T cell PTLD and hepatitis C were independently associated with inferior overall survival, whereas subtype of DLBCL, FoxP3-expression, and EBV-status did not influence survival. In conclusion, monitoring of EBV DNAemia in high-risk patients after allo-HSCT and pre-emptive therapy is valuable for prevention of PTLD. Use of anti­thymocyte globulin increases the risk for EBV+ PTLDs after allo-HSCT and SOT. With long follow-up time, a large proportion of PLTDs after SOT are EBV– with a different clinical presentation. Tregs are rare in PTLD and do not affect survival. The vast majority of PTLDs after SOT is of recipient origin. Graft PTLDs are more likely recipient-derived if disseminated. EBV-status is not associated with intratumoral Tregs or PTLD of recipient origin.
266

La mirada obsesiva: imágenes del tiempo en el cine de vanguardia europeo de los años 20.

Barreiro González, María Soliña 23 May 2011 (has links)
Esta tesis aborda el estudio de la temporalidad moderna a través del cine de vanguardia europeo de los años 20. Este cine recoge todas las temporalidades que habían sido desechadas por la idea lineal y progresiva del tiempo heredada de la Ilustración y desafía de manera sistemática su construcción discursiva y la comprensión histórica que generaba para el periodo de entreguerras. El cine de vanguardia es un medio privilegiado para estudiar la experiencia temporal moderna porque es un complejo compendio de tiempos y discontinuidades. Y a su vez, la temporalidad es clave para definir y estudiar la vanguardia cinematográfica. En ella se unen el interés por la exploración del movimiento, los experimentos con la imagen, la desafección narrativa y la afección por lo real. Propone también la subversión del campo fílmico (y, por veces, social). Los cineastas de vanguardia no construían un discurso temporal alternativo pero sí se dotaban de un cuerpo coherente de revuelta basado en la exploración de esas temporalidades diversas. Trataron también de establecer la imagen como método, de deconstruir la racionalización instrumental del dominio visual y propusieron que de la variedad de discursos temporales en convivencia emanaba una nueva forma de historia y de imagen. / This thesis analyzes the modern temporality through the 20’s European avant-garde cinema. This cinema picks up all the temporalities that have been rejected by the Illustrated idea of time as linear and progressive. As a consequence, this cinema systematically defies the Illustrated discursive construction and the historical comprehension that it elaborated during the Interwars period. Avant-garde cinema was a privileged means to study the modern time experience because it is a complex compendium of times and discontinuities. At the same time, the temporality is a key element to define and study the cinematographic avant-garde. This cinema is characterized by the exploration of movement, the experiments with the image, its lack of interest in narrativity and its interest on the real. It also proposes a subversion of the filmic field (and sometimes, also the social field). Avant-garde filmmakers did not construct an alternative temporal discourse but they organized a coherent uprising corpus based on the exploration of those diverse temporalities. They established the image as a method, the deconstruction of the instrumental rationalization of the visual dominion and they proposed that a new type of history and image emanates from the coexistence of the variety of temporal discourses.
267

Analysis of viral and cellular gene expression patterns in cells latently infected with EBV by suppression subtractive hybridization /

Kiss, Csaba, January 2003 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.
268

A queda da casa de Usher, de Edgar Allan Poe, e La chute de la Maison Usher, de Jean Epstein: um estudo do espaço na literatura e no cinema

Oliveira, Laura Lopes [UNESP] 25 April 2014 (has links) (PDF)
Made available in DSpace on 2015-03-03T11:52:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-04-25Bitstream added on 2015-03-03T12:07:24Z : No. of bitstreams: 1 000805862.pdf: 3460666 bytes, checksum: 30c6f88e4f3a51e9a223372ed7583d20 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho tem como objetivo analisar as estruturas narrativa e fílmica do conto The Fall of the House of Usher (1839), de Edgar Allan Poe (1809-1849), e do filme La Chute de la Maison Usher (1928), dirigido por Jean Epstein (1897-1953), considerando o modo como se constrói o espaço e os sentidos resultantes dessa composição. As obras que tomamos como base teórica para a análise são: Lima Barreto e o Espaço Romanesco (1976), de Osman Lins, A linguagem cinematográfica (2003), de Marcel Martin, A narrativa cinematográfica (2009), de André Gaudreault e François Jost. Assim, analisaremos os procedimentos narrativos utilizados por Poe na composição do espaço e as técnicas cinematográficas que aproximam ou afastam as características do espaço fílmico da narrativa original, o conto / This study aims to analyze the narrative and filmic structures of the tale The Fall of the House of Usher (1839), by Edgar Allan Poe (1809-1849), and the film La Chute de la Maison Usher (1928), directed by Jean Epstein (1897-1953), considering how space is constructed and the meanings resulting from this construction. The works we considered as theoretical basis for the analysis are: Lima Barreto e o Espaço Romanesco (1976), by Osman Lins, A Linguagem Cinematográfica (2003), by Marcel Martin, A narrativa cinematográfica (2009), by André Gaudreault and François Jost. Thus, we analyze the narrative techniques used by Poe in the composition of the space, and the cinematic techniques which bring together the characteristics of the filmic space of the original narrative, namely the tale, or which set them apart
269

Inflammations orales et infection par le virus d’Epstein-Barr : vers un nouveau paradigme en pathogenèse orale / Oral inflammation and Epstein-Barr virus infections : towards a new paradigm in oral pathogenesis

Olivieri, Charles-Vivien 06 December 2018 (has links)
La cavité buccale constitue une porte d’entrée et un site réservoir majeur pour une diversité de virus. Mis à part l’herpèsvirus simplex, peu d’études virologiques détaillent le rôle des virus pathogènes de la sphère orale dont le virus d’Epstein-Barr. Le consensus est que les inflammations orales surviennent principalement en réaction à des infections bactériennes et fongiques provoquant une dysbiose du biofilm oral. Toutefois, ce modèle n’est pas parfait et il explique mal les récidives observées après décontamination, le découplage entre dysbiose et poussées inflammatoires, la proximité de dents atteintes et saines dans un environnement bactérien similaire. L’hypothèse d'un mécanisme synergique combinant virus et bactéries a été proposée pour la parodontite. Selon ce modèle, l’action complémentaire des 2 types d’agents infectieux sur le microenvironnement immunitaire favoriserait la chronicité inflammatoire et l’évolution de la maladie. Nos travaux se concentrent sur l’étude de l’infection de la cavité orale par EBV. EBV est un virus ubiquitaire infectant l’homme de manière persistante. La cavité orale est le site privilégié pour sa réplication avec une production salivaire quasi-constante. Outre un rôle transformant majeur, l’implication de EBV est aussi suspectée pour plusieurs maladies inflammatoires. Tout d’abord, nous nous sommes intéressés au lichen plan oral (LPO), une maladie auto-immune dont l'étiopathogénie n’est pas clairement établie. Sur des biopsies de patients atteints de LPO (n=99), nous avons démontré par hybridation in situ que le LPO est fréquemment infecté par EBV (74%), notamment les formes cliniques érosives. Nous montrons que le degré d’infiltration des lésions par des cellules infectées par EBV (EBV+) est corrélé avec les paramètres inflammatoires et que les cellules EBV+ infiltrées sont des plasmocytes. Cela apporte un élément nouveau dans la mesure où les plasmocytes sont reconnus comme des cellules immunitaires régulatrices majeures. Nous décrivons des profils cytokiniques différents entre LPO infectés ou non, sans qu’il soit possible à ce stade de pouvoir impliquer directement les plasmocytes. Nous confirmons par microscopie électronique que les plasmocytes hébergent les stades tardifs du cycle d’EBV et produisent des virions dans le LPO, suggérant un mécanisme d’amplification locale de l'infection. Ensuite, nous nous sommes intéressés à la parodontite, maladie inflammatoire chronique commune qui détruit la structure parodontale et provoque le déchaussement dentaire. Cette maladie est clairement identifiée comme facteur aggravant de nombreuses maladies systémiques. Nos études avaient déjà mis en évidence un lien direct entre infection EBV et la sévérité de la parodontite. Mes travaux ont permis de montrer que le parodonte inflammatoire est infiltré par des cellules EBV+ qui semblent être majoritairement des plasmocytes. La présence de plasmocytes producteurs de virus au sein de la lésion inflammatoire pourrait expliquer l’infection des épithéliums adjacents. De plus, une étude clinique menée sur une petite cohorte de patients traités pour parodontite met en évidence une corrélation entre la diminution de la charge EBV salivaire et l’amélioration clinique de patients après traitement. Si ce résultat se confirme, il constituerait un argument supplémentaire en faveur d’une contribution de l’infection parodontale par EBV à la globalité de la charge EBV salivaire. En conclusion, nos données mettent en évidence la présence quasi constante d’EBV dans deux types de lésions orales inflammatoires. Cette infection virale contribue à aggraver une situation inflammatoire locale associée ou pas à une dysbiose bactérienne. L’observation majeure concerne la présence, souvent massive, de plasmocytes infectés dont le rôle reste à identifier. Ces observations constituent des avancées significatives qui permettent d’étayer un nouveau modèle de pathogénie orale associant virus et bactéries. / The oral cavity is a major entry point and reservoir site for a variety of viruses. Apart from herpesvirus simplex, few virological studies detail the role of oral pathogenic viruses, including Epstein-Barr virus. The consensus is that oral inflammation occurs mainly in response to bacterial and fungal infections causing dysbiosis of the oral biofilm. However, this model is not perfect and does not explain well the recurrences observed after decontamination, the decoupling between dysbiosis and inflammatory outbreaks, the proximity of affected and healthy teeth in a similar bacterial environment. The hypothesis of a synergistic mechanism combining viruses and bacteria has been proposed for periodontitis. According to this model, the complementary action of the 2 types of infectious agents on the immune microenvironment would promote inflammatory chronicity and disease progression. Our work focuses on the study of oral cavity infection with EBV. EBV is a ubiquitous virus that persistently infects humans. The oral cavity is the preferred site for its replication with almost constant saliva production. In addition to a major transformative role, EBV's involvement is also suspected for several inflammatory diseases. First, we focused on oral plan lichen (OPL), an autoimmune disease whose etiopathogeny is not clearly established. On biopsies of patients with OPL (n=99), we demonstrated by in situ hybridization that OPL is frequently infected with EBV (74%), particularly in erosive clinical forms. We show that the degree of infiltration of lesions by EBV-infected cells (EBV+) is correlated with inflammatory parameters and that the infiltrated EBV+ cells are plasma cells. This brings a new element to the extent that plasma cells are recognized as major regulatory immune cells. We describe different cytokinic profiles between infected and uninfected OPL, although it is not possible at this stage to directly involve plasma cells. We confirm by electron microscopy that plasma cells host the late stages of the EBV cycle and produce virions in the OPL, suggesting a local amplification mechanism of infection. Then, we focused on periodontitis, a common chronic inflammatory disease that destroys the periodontal structure and causes tooth loosening. This disease is clearly identified as an aggravating factor in many systemic diseases. Our studies had already shown a direct link between EBV infection and the severity of periodontitis. My work has shown that the inflammatory periodontium is infiltrated by EBV+ cells, which appear to be predominantly plasma cells. The presence of virus-producing plasma cells within the inflammatory lesion may explain the infection of adjacent epithelia. In addition, a clinical study conducted on a small cohort of patients treated for periodontitis showed a correlation between the decrease in salivary EBV load and the clinical improvement of patients after treatment. If this result is confirmed, it would be an additional argument in favour of a contribution of periodontal EBV infection to the overall salivary EBV burden. In conclusion, our data show the almost constant presence of EBV in two types of inflammatory oral lesions. This viral infection contributes to worsening a local inflammatory situation associated or not with bacterial dysbiosis. The main observation concerns the presence, often massive, of infected plasma cells whose role remains to be identified. These observations represent significant advances that support a new model of oral pathogenesis combining viruses and bacteria.
270

Parental Involvement in Title I Schools: Examining Perspectives of Parents & Teachers

January 2020 (has links)
abstract: ABSTRACT Parental involvement is vital to student success academically as well as socially (Jeynes, 2007; Kim & Hill, 2015). The purpose of this mixed-methods action research study was to examine the perceptions of parental involvement of parents and teachers in a Title I school. A training session intervention, Social Hour, was designed using the Heath and Heath change model (2010) to create an opportunity to learn about parental involvement and educate the school community on the Epstein’s six-types of parental involvement (Epstein, 1987). The goal of the Social Hour workshop was to address the challenges and barriers to parental involvement, previously listed in the literature. Using the lens of Critical Race theory (Blalock, 1967) ensured that the research gives a voice to those who are often marginalized while also helping parents and teachers build a relationship of trust and understanding using principles of Community of Practice (Wenger, 2009). The results of this study indicate that Social Hour-type learning events are significant in the change to perceptions of parental involvement. The participants had a lower level of confidence at the beginning of the session than at the end. Additional qualitative results also suggest a change in attitude after attending the Social Hour. Participants noted they had more energy about parental involvement and were encouraged that parental involvement does not require them to volunteer more; that it is more about being engaged in their child’s education. Overall, participants reported an increase in confidence and had a positive view of parental involvement based on attending the Social Hour workshop. Keywords: Parental involvement, Critical Race theory, Epstein Six Types of Parental involvement / Dissertation/Thesis / Doctoral Dissertation Leadership and Innovation 2020

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