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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.
61

Formules de trace en niveau primaire et non annulation de valeurs centrales de fonctions L automorphes

Rouymi, Djamel 04 November 2009 (has links)
L'étude des propriétés analytiques des fonctions L de formes modulaires est un thème profond de la théorie des nombres. Jusqu'à présent, les propriétés ont essentiellement été établies dans le cas des formes de niveau premier ou sans facteur carré. L'objet de cette thèse est d'établir les bases de l'analyse dans le cas arithmétiquement opposé des niveaux primaires, c'est-à-dire puissances d'un nombre premier. La famille de fonctions L considérée est alors celle obtenue en faisant varier la valuation du niveau. En particulier, on établit une formule de trace qui permet de calculer le troisième moment des valeurs centrales de fonctions L de formes modulaires et d'étudier l'annulation de ces valeurs centrales. / The study of the analytical properties of the modular L-functions is a deep subject in number theory. Up to now, the properties have essentially been established in the case of prime or squarefree level. The aim of this thesis is to give the analytic properties in the arithmetically opposite case of prime power level. The family of L-functions under consideration is the one obtained when the valuation of the level is varying. In particular, we provide a trace formula that allows to compute the third moment of the central values of modular L-functions and to study the vanishing of these L values.
62

Heterotic pool development in Brassica napus L.

Lees, Corey 13 April 2016 (has links)
Hybrid development has become an essential component in many major crop species due to the exploitation of heterosis. However, parental combinations that exhibit high heterotic gains can be difficult to obtain if no prior genetic architecture is known. The current research focuses on heterotic gene pool development using genetic distance and multivariate cluster analysis. Seventy-nine inbred accessions were grouped using three different methods including; 1) phenotypic classification based on 20 qualitative and quantitative traits; 2) Sequence related amplified polymorphisms (SRAP) using 29 forward and reverse primer combinations; 3) genotyping-by-sequencing (GBS) using 80,005 single nucleotide polymorphisms. Both genotypic methods (SRAP and GBS) were compared to each other, and hierarchical clustering produced similar results with 68% homology between the two methods. Heterotic cluster accuracy was investigated between the two genotypic methods through hybrid performance. Forty-four hybrid combinations along with parental cultivars were grown at one location in Winnipeg, MB with three replicates in a randomized complete block design. Hybrid yield and heterosis were regressed against the genetic distance from each genotypic method. GBS was a better predictor of hybrids with high yield (R = 0.47, p <.01); however, SRAP was a better predictor for mid-parent and high-parent heterosis at R = 0.53 and R = 0.61, respectively. This research provides experimental evidence that SRAP and GBS heterotic pool definitions have utility in the prediction of high heterotic parental combinations / May 2016
63

Estudo do papel dos receptores do tipo Toll (TLRs) na indução de CD200 em macrófagos murinos infectados com Leishmania (Leishmania) amazonensis. / Role of Toll-like receptors (TLRs) in CD200 induction in murine macrophages infected with Leishmania (Leishmania) amazonensis.

Sauter, Ismael Pretto 21 November 2017 (has links)
A L. (L.) amazonensis é capaz de evadir a resposta imune do macrófago hospedeiro induzindo a expressão de CD200 na célula. Porém, ainda não se sabe como ocorre este mecanismo. O objetivo deste trabalho foi avaliar a participação dos TLRs na indução de CD200 em macrófagos infectados por L. (L.) amazonensis. Os resultados mostraram que a indução de CD200 por L. (L.) amazonensis é dependente de TLR9 e das proteínas adaptadoras MyD88 e TRIF. Além disso, observamos que CD200 pode ser induzida pelo DNA do parasito, assim como por vesículas extracelulares (VEs) contendo DNA liberadas por ele. Os resultados in vivo mostraram que a ausência de TLR9 não altera o tamanho da lesão e nem a expressão de CD200 nos macrófagos presentes. Contudo, a carga parasitária foi maior nos camundongos selvagens. A partir dos resultados obtidos podemos concluir que a L. (L.) amazonensis induz CD200 de maneira dependente da via de TLRs e que esta indução pode ser estimulada pelo DNA do parasito. / L. (L.) amazonensis evades the immune response of host macrophage inducing the CD200 expression in the cell. However, it is not yet known how this mechanism occurs. The objective of this work was to evaluate the participation of TLRs in CD200 induction in infected macrophages by L. (L.) amazonensis. The results showed that the CD200 induction by the parasite is dependent on TLR9 and the adaptor proteins MyD88 and TRIF. In addition, we observed that the CD200 can be induced by the parasite DNA, as well as by extracellular vesicles (EVs) containing DNA released by it. In vivo results showed that the absence of TLR9 does not alter the lesion size nor the CD200 expression in macrophages present in the lesion. However, the parasite load was higher in wild type mice. Therefore, we can conclude that the CD200 induction by L. (L.) amazonensis amastigotes is TLR dependent and this can be stimulated by the parasite DNA.
64

The development of a research culture in Tanzania's higher education system

Fussy, Daniel Sidney January 2017 (has links)
The study reported in this thesis investigated approaches which the higher education sector in Tanzania employs to develop a research culture, and explored views on how to improve the research capacity within Tanzanian universities. A qualitative-multiple case study informed by interviews, focus group discussions and documentary review methods facilitates the data collection process. Six research sites including the Ministry of Education, the Tanzania Commission for Universities and four leading universities were involved in the study. Purposive and stratified sampling techniques were used to recruit participants from the group of senior government officials, senior university leaders, academic staff members and postgraduate students. The selected Stufflebeam’s CIPP framework guided the conduct of the study, as well as the discussion and interpretation of the findings. The findings show that the Tanzanian higher education policy context has feasible policies and plans that support the development of research in the country’s universities. However, the higher education policy context lacks proper mechanisms to engender practical development and the monitoring of research. Moreover, the approaches used to develop research, although reported to improve institutional research profile, were found to be less demanding in enforcing the research culture. The findings also identified factors essential in building a research culture, such as research training, research mentoring, research funding and research incentives, which serve as a framework for universities and researchers across Tanzania, Africa and the world, to guide their decisions and actions towards promoting successful research cultures. The study, therefore, concludes that Tanzania needs to develop a deep-seated research culture within its higher education system to improve the production and application of knowledge, and eventually realise the National Development Vision 2025 that the country envisages, to advance from ‘less developed’ country status into a respectable ‘middle-income’ country. In so doing, the study recommends a reform of the national higher education policy to bridge the gap between policy articulations and implementation on the ground.
65

Pesquisa de genes de virulência em cepas de Listeria monocytogenes e Listeria innocua originárias de carne suína e ambiente de abatedouros e açougues / Research of virulence genes in strains of Listeria monocytogenes and Listeria innocua originated from pork and slaughterhouse and meat market environment

Moreno, Luisa Zanolli 23 May 2013 (has links)
Introdução - A bactéria Listeria monocytogenes é um agente zoonótico transmitido, principalmente, por alimentos. Dentre as fontes de contaminação, destacam-se os produtos de origem láctea, carnes e embutidos, além dos ambientes da indústria de processamento alimentício. Na última década, foram detectadas cepas de L. monocytogenes e L. innocua, em ambiente de frigoríficos e alimento. Estas apresentavam variação na intensidade da virulência para células eucarióticas decorrente de mutações nos genes de virulência. Esta alteração em ambas as espécies, e o relato de um caso fatal de listeriose humana ocasionada por L. innocua atípica demandam atenção, pois apresentam maior risco à saúde da população exposta a estes ambientes e alimentos tornando-se, portanto, uma importante questão de saúde pública. Objetivo - Pesquisar genes de virulência em cepas de L. monocytogenes e L. innocua, isoladas em pontos da linha de abate suíno e do comércio de carne no Estado de São Paulo. Material e Métodos Foram estudadas 40 cepas, dentre estas, isolados de L. monocytogenes e L. innocua com atividade hemolítica atípica. Foram realizados testes de atividade hemolítica e produção de fosfolipase A para caracterização dos isolados. A detecção dos genes de virulência foi realizada através da reação em cadeia pela polimerase (PCR). Para confirmação das sequências amplificadas e a análise das mesmas, os fragmentos obtidos foram sequenciados. A identificação molecular das espécies foi realizada por análise filogenética dos genes prs e 16S rRNA. Resultados Dos 40 isolados, cinco de L. monocytogenes e sete de L. innocua apresentaram atividade hemolítica atípica, sendo que nestes últimos também foi observado halo atípico no meio ALOA. As cepas de L. monocytogenes foram positivas para a detecção de todos os genes de virulência estudados. Dois dos isolados atípicos de L. innocua também foram positivos para todos os genes e os outros cinco foram positivos para hly, plcA e inlC. Foram detectadas mutações nas proteínas InlC, InlB, InlA, PI-PLC, PC-PLC e PrfA, nas cepas atípicas, que resultaram em alterações nas suas estruturas secundárias que podem explicar o fenótipo desses isolados. A confirmação de espécie apenas foi alcançada com a análise filogenética do 16S rRNA. Conclusões A partir desses resultados, foi proposta a utilização dos genes prfA, plcB e inlB, como forma de triagem, para diferenciar as espécies L. monocytogenes e L. innocua, de modo a complementar os testes fenotípicos / Introduction - The bacterium Listeria monocytogenes is a zoonotic agent transmitted, mainly, by food. Among the sources of contamination, stands out dairy products, meat and the environments of food processing industry. In the last decade, strains of L. monocytogenes and L. innocua have been detected in food and slaughterhouses environment. These presented variation in the intensity of virulence to eukaryotic cells due to mutations in the virulence genes. These changes in both species, and the report of a fatal case of human listeriosis caused by atypical L. innocua demand attention, because they present greater risk to the health of the population exposed to these environments and food and, therefore, it is an important public health issue. Objective - To search for the virulence genes in strains of L. monocytogenes and L. innocua isolated in points of swine slaughter line and meat trade in Sao Paulo State. Material and Methods 40 strains were studied, among these, isolates of L. monocytogenes and L. innocua with atypical hemolytic activity. Tests of hemolytic activity and production of phospholipase A were performed for isolates characterization. The detection of virulence genes was performed through polymerase chain reaction (PCR). For confirmation of the amplified sequences and analysis of the same, the obtained fragments were sequenced. The molecular identification of species was performed by phylogenetic analysis of 16S rRNA and prs genes. Results - Of the 40 isolates, five L. monocytogenes and seven L. innocua showed atypical hemolytic activity, and in these last ones an atypical halo was also observed in ALOA medium. The L. monocytogenes strains were positive for detection of all virulence genes studied. Two atypical L. innocua isolates were also positive for all genes and the other five were positive for hly, plcA and inlC. Mutations in InlC, InlB, InlA, PI-PLC, PC-PLC and PrfA proteins were detected, in the atypical strains, which resulted in changes in their secondary structures that may explain the isolates phenotype. Species confirmation was achieved only with phylogenetic analysis of 16S rRNA. Conclusions - From these results, it was proposed the use of prfA, plcB and inlB genes as a way of screening, to differentiate the species L. monocytogenes and L. innocua, in order to complement the phenotypic tests
66

Inhabiting a woman's world : the experience of male general student nurses in the Republic of Ireland

Neary, Maria January 2018 (has links)
This thesis explores the experience of being a male general student nurse in the feminised world of nursing in the Republic of Ireland, where only 5% of general nurses are male. The main focus of the thesis is the experienceof male general student nurses in relation to their conceptualisations of their work, their masculinities and how they negotiate gendered identities. The research questions centred on the men’s feelings, perceptions and ways of coping and therefore the overall approach was framed within a broadly interpretative perspective. Using Interpretative Phenomenological Analysis (IPA) the thesis set out to research how the male general nurses make sense of the world in which they find themselves and specifically what it is to be a male general student nurse in the female world of nursing. I carried out 10 in-depth one-to-one interviews with male general student nurses who were in their final year of training. The findings showed that the participants considered they were treated differently because of their gender. Discrimination was both positive and negative. This thesis represents a snapshot in time. It contributes to the overall knowledge of what it is like to be a male general student nurse in the feminised world of nursing in the Republic of Ireland. At the time of the thesis, there was little other research work on a similar cohort of participants. The thesis illuminates the advantages and disadvantages to being male in this world, even before they complete the programme and become registered general nurses.
67

How young volunteers learn in practice from established volunteers : an examination of volunteer learning in community radio in the UK

Kyneswood, Benjamin Paul January 2017 (has links)
In this thesis I examined the learning in practice of fourteen young volunteers at four community radio stations in the UK. I queried what learning in practice as a volunteer constituted by examining how the participants accessed support and knowledge from established members, and how practice defined their volunteering and learning. Using an interpretivist methodology applied to private blogs and group interviews, participants recorded their perspectives for between six and nine months. Communities of Practice theory (Lave & Wenger, 1991) was applied to understand how the participants developed their learning relationship with established members. Analysis reveals that established members legitimised participant practice through three phases; an initial phase of broadcasting training where participants began at the periphery of the membership; a second phase of broadcast reviews that sought to develop their relationship with members; and a third phase of non broadcast activities to establish their membership. The relationship between the participants and established members meant the phases were not linear. Participants creatively constructed their broadcasts by developing a fragile, embryonic network of active citizenship (Kenny et al., 2015) to generate community content. In doing so not all participants wanted to establish themselves as members and engage in non-broadcast activities, and drew distinctions between broadcast practice on the periphery and the community development practice of established members. My original contribution to the literature is that by examining volunteering as a learning practice the hidden pressures and conflicts in relationship between newcomers and established members are revealed. I argue that becoming an established member of a voluntary organisation may not be for everyone, but that this does necessarily mean a loss of committed practice to the organisation. Initial volunteering opportunities that are exploratory and creative can establish commitment. I therefore link commitment to practice as a volunteer, rather than as a biographic strategy as suggested elsewhere in the literature.
68

Institutional commitment to widening participation : mission, rhetoric and framing

Graham, Claire Louise January 2010 (has links)
This thesis is based upon a case study of six higher education institutions (HEIs) and their ‘framing’ of commitment to widening participation. Using elements of Fairclough’s (1995) critical discourse analysis, the thesis analyses the discursive strategies that the HEIs used to position their widening participation work in marketing literature and open day settings, as well as via policy documents and statements made by staff. Bernstein’s (1990) notions of classification and framing are applied as a framework for understanding how widening participation work is presented as part of a ‘whole institution’ approach to marketing. The thesis argues that the discursive strategies of the pre-92 HEIs suggested a highly contingent approach to widening participation. Strong framing around standards and selectivity was coupled with weak framing of widening participation. The post-92 HEIs evidenced stronger framing of widening participation but this was positioned alongside a recruitment-oriented discourse of persuasion. Government policy appeared to have had a limited effect in terms of changing existing institutional cultures. It is recommended that the government enforce tighter regulation around widening participation work in HEIs; ensuring that widening participation is embedded into institutional structures and that marketing literature and open day settings reflect this more accessible ethos.
69

Followership among secondary school teachers

Francis, Andrew Frank January 2016 (has links)
Today, it is encouraging that followership is regarded as a factor within the leadership equation. However, research attention on followership overall is limited and within the field of education, its study remains firmly in the shadows. Indeed, a search for published followership-centric research carried out in this field revealed just 17 studies worldwide, with Thody’s contribution (2003) the sole point of reference within the UK. This study contributes to this limited body of research by exploring the followership of schoolteachers working in the secondary education sector. Using Gronn’s Career Model (1999) as a framework to understand why teachers follow, the study used biographical-style interviews (n=15) to reveal factors that have shaped the agency of schoolteachers, influencing their journeys to followership. In addition, the study administered Kelley’s (1992) Followership Questionnaire in order to understand how teachers follow (n=69). Factors found to influence why teachers follow included the role of parents, schooling and of key people and these findings align with research carried out on the career journeys of senior educational leaders. In addition, the combined insight drawn from the quantitative and qualitative data revealed a predominance of exemplary followership among the teachers. The study suggests that this approach to followership is dominant among teachers due to them being engaged in leadership practice, both within and beyond the classroom. Further, that teachers’ commitment to task, enhanced through working in a profession that enables them to satisfy important personal values and beliefs, also encourages the practice of exemplary followership.
70

How and in what ways can participation in extra-curricular activity enable learning?

Cutting, Anna January 2014 (has links)
Mark and Nathan were two of the laziest boys I had ever had to teach in my life. Avoiding work was an art form to them – the skills they had developed to look busy, whilst actually doing very little, were legendary. This all changed when they decided that they wished to participate in the Duke of Edinburgh’s Award Scheme and, upon returning from the expedition element of the Award, they were like new students. The purpose of this research was therefore to find out whether it was the participation in outdoor education and, in particular, the Duke of Edinburgh’s Award Scheme, that enabled young people to become better learners once back in the traditional classroom environment. This thesis explores the concepts of learning, identity and motivation through sampling a small group of Duke of Edinburgh’s Award Scheme participants at an 11-18 mixed ability comprehensive school in Dudley. Through observational and semi-structured interview data, combined with auto-ethnographical vignettes, the changing patterns of Award Scheme participants’ behaviours have been analysed. The research argues that such activities and experiences provide students with opportunities to acquire new skills and new ways of being that become transferrable to situations back in the traditional classroom environment.

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