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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.
171

T Cells Aid in Limiting Pathogen Burden and in Enhancing B1 and B2 Cell Antibody Responses to Membrane Glycolipid and the Surface Lipoprotein Decorin-Binding Protein A during Borrelia burgdorferi Infection: A Dissertation

Marty-Roix, Robyn Lynn 15 June 2010 (has links)
Murine infection by the Lyme disease spirochete, B. burgdorferi, results in the generation of pathogen-specific antibody that can provide protection against Lyme disease, but the cells involved in this response are poorly characterized. T cells are not required for generating a protective antibody response to B. burgdorferi infection, but their exact role in providing protection against tissue colonization had not been previously determined. We found that TCRβxδ;-/- mice were susceptible to high pathogen loads and decreased antibody titers, but inhibition of CD40L-dependent interactions resulted in partial protection suggesting that a portion of the help provided by T cells was not dependent on CD40L-CD40 interactions between T and B cells. RAG1-/- mice reconstituted with either un-fractionated or B1-enriched peritoneal cells from previously infected mice generated B. burgdorferi-specific antibody, and upon spirochetal challenge suffered significantly lower levels of pathogen load in the joint and heart. Peritoneal cells from previously infected TCRβxδ-/- mice or B2-enriched or B1-purified peritoneal cells conferred little to only moderate protection, suggesting T cells play an important role in protection against spirochetal infection the joint. Consistent with this, T cells from previously infected donor mice, when transferred with B1 or B2 cells into RAG1-/- mice, generated increased antibody titers and were capable of diminishing bacterial burden in the joint and heart. A previously identified class of protective antibody is directed against the spirochetal surface lipoprotein DbpA, and we found that DbpA is a prominent protein antigen recognized by RAG1-/- mice reconstituted with B1-enriched peritoneal cells. Additionally, we found that mice reconstituted with B1 cells also make antibody directed towards the spirochetal glycolipid antigen, BbGL-IIc, which is recognized by Vα14iNKT cells. Consistent with the idea that T cells are important in providing protection against spirochetal infection, RAG1-/- mice reconstituted with B1 and T cells generated a more robust response against DbpA and BbGL-IIc. These results support the hypothesis that T cells act with B1 cells in a CD40L-independent manner to promote the production of antibodies that play an important role in protection of the joint from spirochetal infection.
172

The Spatial and Molecular Epidemiology of Lyme Disease in Eastern Ontario

Slatculescu, Andreea M. 11 August 2023 (has links)
Lyme disease is an emerging tick-borne illness in Canada, with human case numbers increasing 15- to 20-fold since Lyme disease became nationally notifiable in 2009 until the present. In Ontario, Canada's largest province by population, average Lyme disease incidence across the province is similar to that of national estimates. However, in eastern Ontario, which is near tick endemic regions in the northeastern Unites States, Lyme disease incidence is disproportionately higher compared to the rest of the province. The objectives of this thesis are to identify environmental Lyme disease risk areas in Ontario, to explore spatiotemporal trends in Lyme disease emergence, and to identify neighbourhood-level socioecological risk factors for Lyme disease. In addition, this thesis also aims to assess the risk of other tick-borne illnesses that are transmitted by the blacklegged tick, Ixodes scapularis, which is also the main vector for Lyme disease in Canada. Using maximum entropy species distribution modelling to correlate blacklegged tick occurrence data with environmental variables, predictive risk models for I. scapularis and the Lyme disease pathogen, Borrelia burgdorferi, were developed. The model prediction was used to classify low and high environment risk areas and, using a case-control epidemiological study, we assessed that residence in risk areas was a strong predictor of Lyme disease. However, this relationship was modulated by socioecological factors linked to higher overall rurality of the locality of home residence. Spatial cluster analyses further revealed that human Lyme disease cases clustered in regions with the high numbers of reported B. burgdorferi-infected ticks in the environment. Many individuals residing in large metropolitan regions, like the City of Ottawa, reported tick exposures outside their public health unit of residence; however, local clusters of Lyme disease were also detected in suburban regions near conservation areas, trails, and urban woodlands. The prevalence of other tick-borne pathogens was low, although several pathogens of public health significance including Borrelia miyamotoi and Anaplasma phagocytophilum were detected at multiple sites surveyed for ticks between 2017-2021. Overall, this thesis identify patterns in Lyme disease emergence (and potentially other tick-borne illnesses), defines environmental risk areas for Lyme disease in Ontario, and highlights important socioecological risk factors for Lyme disease in eastern Ontario.
173

Mesurer et prédire l'adaptation aux changements climatiques dans les municipalités québécoises : développement et validation d'indices et mesure des déterminants psychosociaux de l'action

Jacob, Johann 09 November 2022 (has links)
Alors que les entités municipales se trouvent devant la nécessité d'agir pour protéger leurs populations des impacts liés à différents aléas climatiques, l'évaluation des progrès réalisés en adaptation fait l'objet d'un intérêt grandissant. Or, faute d'approches permettant d'évaluer objectivement les progrès des efforts municipaux d'adaptation, il apparaît nécessaire, dans le développement d'indicateurs d'adaptation, d'accorder une grande importance aux aspects méthodologiques et psychométriques, telles la fidélité et la validité des instruments de mesure. Cette thèse poursuit donc deux objectifs généraux. Elle vise d'abord à développer et valider deux indices de mesure en vue de dresser un portrait de la situation actuelle en ce qui concerne les municipalités québécoises en matière de pratiques et comportements d'adaptation aux impacts des vagues de chaleur/inondations et à la maladie de Lyme. Elle vise ensuite à identifier les facteurs associés à l'adoption par les municipalités québécoises d'interventions d'adaptation relatives à ces trois aléas. La thèse repose sur trois articles. Le premier article illustre le processus d'élaboration et de validation, à l'aide d'analyses métrologiques, d'un indice d'adaptation aux vagues de chaleur et aux inondations à l'échelle des urbanistes et des aménagistes œuvrant au sein d'entités municipales québécoises. Le second article s'appuie sur la théorie du comportement planifié (TCP) ainsi que sur certains construits théoriques du modèle des croyances relatives à la santé afin de prédire l'adoption d'interventions préventives pour la maladie de Lyme à l'échelle des municipalités québécoises. Enfin, le troisième article identifie les facteurs psychosociaux de la TCP qui prédisent et expliquent le mieux l'adoption de comportements d'adaptation, cette fois à la chaleur et aux inondations, par les autorités municipales du Québec. Les indices développés permettent de jeter un premier regard multidimensionnel sur le niveau d'adaptation des municipalités québécoises. Les résultats montrent que de façon générale, les municipalités sont actives bien qu'elles soient moins souvent engagées dans des mesures structurantes d'adaptation - qui peuvent avoir des implications financières et stratégiques importantes pour l'organisation – que dans des mesures préparatoires à l'adaptation. Ces résultats suggèrent que les municipalités sont relativement nombreuses à adopter des actions d'adaptation, sans pour autant s'inscrire dans une démarche officielle d'adaptation, au sens d'un processus continu de gestion adaptative. Quant aux facteurs associés à l'adoption de mesures d'adaptation, les analyses ont montré que, contrairement aux normes sociales, les attitudes à l'égard de l'adoption de pratiques d'adaptation et les barrières perçues semblent représenter des prédicteurs importants de l'adaptation à l'échelle des municipalités québécoises. Les barrières perçues peuvent également modérer l'association entre l'intention d'agir et l'adoption de mesures d'adaptation, ce qui suggère que la force de l'association entre l'intention et la décision de passer à l'action se trouve réduite lorsque les responsables municipaux perçoivent des obstacles à l'action. Les résultats de cette thèse ont des implications importantes sur le plan du suivi et évaluation des progrès en matière d'adaptation, ainsi qu'en ce qui concerne la conception d'interventions visant à favoriser l'adoption de pratiques d'adaptation. / While municipal entities are faced with the need to act to protect their populations from the impacts related to various climate hazards, there is a growing interest in assessing the progress made in terms of adaptation. That said, given the lack of approaches for objectively assessing progress from municipal adaptation efforts, it appears necessary, when developing adaptation indicators, to attach great importance to the methodological and psychometric aspects, such as reliability and validity of the measurement instruments. Consequently, this thesis has two general objectives. The first is to develop and validate two measurement indices with a view to drawing a portrait of the current situation in Quebec municipalities regarding practices and behaviours for adapting to heat waves, floods and Lyme disease. The next objective is to identify the factors associated with Quebec municipalities' implementation of adaptation interventions related to these three hazards. The thesis is based on three articles. The first article illustrates the development and validation process, using metrological analyses, of an index of adaptation to heat waves and floods at the level of urbanists and urban planners working in Quebec's municipal entities. The second article rests on the theory of planned behaviour as well as on some theoretical constructs of the health belief model to predict the implementation of preventive interventions for Lyme disease across Quebec municipalities. Finally, the purpose of the third article is to identify the psychosocial factors of the theory of planned behaviour that best predict and explain the adoption of adaptation behaviours, this time to heat and floods, by Quebec's municipal authorities. The indices developed help provide a first multidimensional view of Québec municipalities' levels of adaptation. The results show that, generally, the municipalities are active, even though they are less frequently involved in structuring adaptation measures which may have significant financial and strategic implications for the organization than in the adoption of groundwork adaptation actions. These results suggest that a relatively large number of municipalities are carrying out adaptation actions, but not as part of an official adaptation process, in the sense of continuous adaptive management. As for the factors associated with the implementation of adaptation measures, the analyses showed that contrary to social norms, attitudes towards the adoption of adaptation practices and perceived barriers seem to represent important predictors of adaptation across Quebec municipalities. Perceived barriers may also moderate the association between the intention to act and the adoption of adaptation measures, which suggests that the strength of the association between the intention and the decision to take action is reduced when municipal officials perceive obstacles to the action. The results of this thesis have significant implications for the monitoring and evaluation of the progress made in terms of adaptation, as well for the designing of interventions intended to promote the implementation of adaptation practices.
174

Infection Prevalence in a Novel Ixodes scapularis Population in Northern Wisconsin

Westwood, Mary Lynn 30 August 2017 (has links)
No description available.
175

Mesurer et prédire l'adaptation aux changements climatiques dans les municipalités québécoises : développement et validation d'indices et mesure des déterminants psychosociaux de l'action

Jacob, Johann 09 November 2022 (has links)
Alors que les entités municipales se trouvent devant la nécessité d'agir pour protéger leurs populations des impacts liés à différents aléas climatiques, l'évaluation des progrès réalisés en adaptation fait l'objet d'un intérêt grandissant. Or, faute d'approches permettant d'évaluer objectivement les progrès des efforts municipaux d'adaptation, il apparaît nécessaire, dans le développement d'indicateurs d'adaptation, d'accorder une grande importance aux aspects méthodologiques et psychométriques, telles la fidélité et la validité des instruments de mesure. Cette thèse poursuit donc deux objectifs généraux. Elle vise d'abord à développer et valider deux indices de mesure en vue de dresser un portrait de la situation actuelle en ce qui concerne les municipalités québécoises en matière de pratiques et comportements d'adaptation aux impacts des vagues de chaleur/inondations et à la maladie de Lyme. Elle vise ensuite à identifier les facteurs associés à l'adoption par les municipalités québécoises d'interventions d'adaptation relatives à ces trois aléas. La thèse repose sur trois articles. Le premier article illustre le processus d'élaboration et de validation, à l'aide d'analyses métrologiques, d'un indice d'adaptation aux vagues de chaleur et aux inondations à l'échelle des urbanistes et des aménagistes œuvrant au sein d'entités municipales québécoises. Le second article s'appuie sur la théorie du comportement planifié (TCP) ainsi que sur certains construits théoriques du modèle des croyances relatives à la santé afin de prédire l'adoption d'interventions préventives pour la maladie de Lyme à l'échelle des municipalités québécoises. Enfin, le troisième article identifie les facteurs psychosociaux de la TCP qui prédisent et expliquent le mieux l'adoption de comportements d'adaptation, cette fois à la chaleur et aux inondations, par les autorités municipales du Québec. Les indices développés permettent de jeter un premier regard multidimensionnel sur le niveau d'adaptation des municipalités québécoises. Les résultats montrent que de façon générale, les municipalités sont actives bien qu'elles soient moins souvent engagées dans des mesures structurantes d'adaptation - qui peuvent avoir des implications financières et stratégiques importantes pour l'organisation – que dans des mesures préparatoires à l'adaptation. Ces résultats suggèrent que les municipalités sont relativement nombreuses à adopter des actions d'adaptation, sans pour autant s'inscrire dans une démarche officielle d'adaptation, au sens d'un processus continu de gestion adaptative. Quant aux facteurs associés à l'adoption de mesures d'adaptation, les analyses ont montré que, contrairement aux normes sociales, les attitudes à l'égard de l'adoption de pratiques d'adaptation et les barrières perçues semblent représenter des prédicteurs importants de l'adaptation à l'échelle des municipalités québécoises. Les barrières perçues peuvent également modérer l'association entre l'intention d'agir et l'adoption de mesures d'adaptation, ce qui suggère que la force de l'association entre l'intention et la décision de passer à l'action se trouve réduite lorsque les responsables municipaux perçoivent des obstacles à l'action. Les résultats de cette thèse ont des implications importantes sur le plan du suivi et évaluation des progrès en matière d'adaptation, ainsi qu'en ce qui concerne la conception d'interventions visant à favoriser l'adoption de pratiques d'adaptation. / While municipal entities are faced with the need to act to protect their populations from the impacts related to various climate hazards, there is a growing interest in assessing the progress made in terms of adaptation. That said, given the lack of approaches for objectively assessing progress from municipal adaptation efforts, it appears necessary, when developing adaptation indicators, to attach great importance to the methodological and psychometric aspects, such as reliability and validity of the measurement instruments. Consequently, this thesis has two general objectives. The first is to develop and validate two measurement indices with a view to drawing a portrait of the current situation in Quebec municipalities regarding practices and behaviours for adapting to heat waves, floods and Lyme disease. The next objective is to identify the factors associated with Quebec municipalities' implementation of adaptation interventions related to these three hazards. The thesis is based on three articles. The first article illustrates the development and validation process, using metrological analyses, of an index of adaptation to heat waves and floods at the level of urbanists and urban planners working in Quebec's municipal entities. The second article rests on the theory of planned behaviour as well as on some theoretical constructs of the health belief model to predict the implementation of preventive interventions for Lyme disease across Quebec municipalities. Finally, the purpose of the third article is to identify the psychosocial factors of the theory of planned behaviour that best predict and explain the adoption of adaptation behaviours, this time to heat and floods, by Quebec's municipal authorities. The indices developed help provide a first multidimensional view of Québec municipalities' levels of adaptation. The results show that, generally, the municipalities are active, even though they are less frequently involved in structuring adaptation measures which may have significant financial and strategic implications for the organization than in the adoption of groundwork adaptation actions. These results suggest that a relatively large number of municipalities are carrying out adaptation actions, but not as part of an official adaptation process, in the sense of continuous adaptive management. As for the factors associated with the implementation of adaptation measures, the analyses showed that contrary to social norms, attitudes towards the adoption of adaptation practices and perceived barriers seem to represent important predictors of adaptation across Quebec municipalities. Perceived barriers may also moderate the association between the intention to act and the adoption of adaptation measures, which suggests that the strength of the association between the intention and the decision to take action is reduced when municipal officials perceive obstacles to the action. The results of this thesis have significant implications for the monitoring and evaluation of the progress made in terms of adaptation, as well for the designing of interventions intended to promote the implementation of adaptation practices.
176

Identification des variables favorisant l'adoption des comportements préventifs de la maladie de Lyme

Tapsoba, Rodolphe 14 June 2023 (has links)
Thèse ou mémoire avec insertion d'articles / Les changements climatiques ont entrainé une augmentation de l'incidence de la maladie de Lyme en Amérique du Nord. Au Canada, depuis que la maladie de Lyme est devenue une maladie à déclaration obligatoire au niveau national, le nombre de cas humains signalés est passé de 144 cas en 2009 à 2 851 en 2021. En l'absence de vaccin, les interventions visant à protéger les populations contre la maladie de Lyme reposent essentiellement sur la promotion des comportements individuels servant à se prémunir des piqûres de tiques. Malheureusement, ces mesures individuelles de prévention ne semblent pas suffisamment mises en pratique. Cette étude vise à identifier les facteurs saillants qui entravent ou qui pourraient faciliter l'adaptation des populations à la maladie de Lyme. Elle poursuit précisément un double objectif : d'identifier les prédicteurs saillants de l'adoption des comportements visant à se prémunir des piqûres de tiques au sein des différents groupes définis par l'âge et le niveau de scolarité d'une part, et d'autre part de déterminer les différents profils d'adaptation à la maladie de Lyme à partir des prédicteurs saillants retenus dans chaque groupe grâce à la régression par copules. Les données ont été collectées auprès de 3941 adultes vivant dans une zone à risque pour la maladie de Lyme. Les participants ont rempli un questionnaire par téléphone (n = 1003) ou sur le Web (n = 2938). Le questionnaire permettait de savoir s'ils adoptaient ou non les comportements servant à se prémunir des piqûres de tiques proposés par les responsables de la santé publique du Québec. Il mesurait également certaines variables de la Théorie du Comportement Planifié, notamment leur attitude ou les normes sociales perçues concernant les comportements. La méthode d'analyse statistique utilisée est la régression par copules. Nos résultats ont d'abord permis d'identifier les prédicteurs saillants de l'adaptation à la maladie de Lyme au sein de six sous-groupes définis par l'âge et le niveau de scolarité. Les prédicteurs sélectionnés par la régression par copules étaient les suivants : l'intention, la susceptibilité, la connaissance de la maladie de Lyme, le risque perçu, la sévérité perçue, la présence d'enfant dans le ménage, la perception de contrôle et les normes sociales. Leur sélection et leur pouvoir de prédiction diffèrent d'un groupe à un autre, avec quelques similarités remarquables entre les groupes. Ensuite, en « profilant » les participants selon leurs réponses aux questions pertinentes à la prédiction de l'adaptation, nous avons analysé dans chaque groupe les dix profils de réponse qui maximisaient les valeurs conditionnelles attendues de l'adaptation à la maladie de Lyme. Nous concluons que l'âge et le niveau de scolarité jouent dans la décision des individus d'adopter les comportements visant à se prémunir des piqûres de tiques, parce qu'en marge des similitudes notables entre les groupes, des spécificités d'intérêt en termes d'orientation des interventions ont été également identifiées dans certains groupes. En plus, il existe plusieurs manières de bien s'adapter à la maladie de Lyme. Ces informations peuvent donc être utilisées par les autorités sanitaires pour développer des interventions éducatives plus ciblées et plus efficaces dans le cadre de la lutte pour l'amélioration de l'adoption des comportements servant à se prémunir des piqûres de tiques. / Climate change has led to an increase in the incidence of Lyme disease. In Canada, since Lyme disease became a nationally notifiable disease, the number of reported human cases has increased from 144 cases in 2009 to 2,851 in 2021. In the absence of a vaccine, interventions to protect populations from Lyme disease rely primarily on the promotion of individual behaviours to protect against tick bites. Unfortunately, these individual prevention measures do not appear to be sufficiently practiced. This study aims to identify salient factors that hinder or facilitate population adaptation to Lyme disease. Specifically, it has two objectives: to identify salient predictors of the adoption of behaviours to protect against tick bites within different groups defined by age and education level on the one hand, and on the other hand to determine the different patterns of adaptation to Lyme disease based on the salient predictors selected in each group through copula regression. Data were collected from 3941 adults living in an area at risk for Lyme disease. Participants completed a questionnaire by telephone (n = 1003) or on the Web (n = 2938). The questionnaire asked whether or not they adopted the behaviours to prevent tick bites proposed by Quebec public health officials. It also measured certain Theory of planned behaviour (TPB) variables, including their attitudes or perceived social norms regarding Lyme disease preventive behaviours (LDPB). The statistical analysis method used was copula regression. Our results first identified salient predictors of adjustment to Lyme disease within six subgroups defined by age and education. The predictors selected by copula regression were intention, susceptibility, knowledge of Lyme disease, perceived risk, perceived severity, presence of children in the household, perceived control, and social norms. Their predictive power and selection differed from group to group, with some remarkable similarities between groups. Next, by "profiling" respondents with identical responses to the variables most predictive of adaptation in each group, we analyzed the 10 profiles in each group that maximized the expected conditional values of Lyme disease adaptation. We conclude that age and education level play a role in individuals' decision to engage in behaviours to protect themselves from tick bites, because, in addition to the notable similarities between the groups, specificities of interest in terms of the orientation of the interventions were also identified in some groups. Furthermore, there are many ways to cope well with Lyme disease. This information can be used by health authorities to develop more targeted and effective educational interventions in the fight to improve the adoption of tick-bite prevention behaviours.
177

<b>Two Case Studies on the Use of Public Bioinformatics Data Toward Open-Access Research</b>

Daphne Rae Krutulis (18414876) 20 April 2024 (has links)
<p dir="ltr">Open-access bioinformatics data enables accessible public health research for a variety of stakeholders, including teachers and low-resourced researchers. This project outlines two case studies utilizing open-access bioinformatics data sets and analysis software as proofs of concept for the types of research projects that can be adapted for workforce development purposes. The first case study is a spatial temporal analysis of Lyme disease rates in the United States from 2008 to 2020 using freely available data from the United States Department of Agriculture and Centers for Disease Control and Prevention to determine how urbanization and other changes in land use have impacted Lyme disease rates over time. The second case study conducts a pangenome analysis using bacteriophage data from the Actinobacteriophage Database to determine conserved gene regions related to host specificity.</p>
178

In vitro test buněčné imunitní odpovědi pro diagnostiku Lymeské boreliózy / Lyme borreliosis diagnostics using in vitro cellular immune response testing

Prokopová, Tereza January 2017 (has links)
Lyme borreliosis is a multisystemic disease affecting skin, joints, heart and central nervous system. The disease is caused by spirochetes of Borrelia burgdorferi sensu lato complex. These bacteria are spread by ticks of Ixodes genus. In 2016 there were almost 4,000 newly infected individuals reported in the Czech Republic. Contemporary serological diagnostics of Lyme borreliosis is not sensitive nor specific enough and does not even correlate with the pathology of the disease in the early or late phases. For the correct diagnosis of the disease it is necessary to detect the pathogen and its genotype. For this reason we had aimed at two goals. Through the digital droplet PCR (ddPCR) method we detected Borrelia-specific DNA and its genotype. The detection limit of borrelial DNA was set on gDNA samples isolated from the tick. Detection threshold for the initial amount of 1 ng of tick gDNA is at the range of 10-17 g of specific borrelial DNA. Borrelia spp. coinfection was detected in 5 out of 12 tested samples. The most frequent type was B. garinii which was detected in 5 samples. On the basis of published sequences for virulent factors we have designed specific primers in conserved regions of the genes flanking their variable segments to be PCR amplified. Gene variability will be monitored through...
179

Analýza výskytu vybraných zoonóz v Jihočeském kraji / Analysis of occurrences of selected zoonoses in South Bohemian region

SOUMAROVÁ, Michaela January 2015 (has links)
This diploma thesis is focused on the evaluation of six selected zoonoses with the occurrence in South Bohemia (campylobacteriosis, salmonellosis, listeriosis, tick-borne meningoencephalitis, Lyme borreliosis, tularemia) between the years 2003-2013. Campylobacteriosis and salmonellosis were evaluated the most common zoonoses in the South Bohemian Region during the monitored period. Their common feature is the alimentary transmission. Between 2003 to 2008 salmonellosis recorded the highest number of reported cases, on the contrary, campylobacteriosis has reported the highest number of occurrences since 2008. District of Czech Budweis showed the highest incidence of both zoonoses during the monitored period (4,139 cases of salmonellosis and 4,924 cases of campylobacteriosis). Another but not less important zoonotic is tick-borne meningoencephalitis, which incidence had the highest number in South Bohemian Region of all the regions of Czech Republic. The second part of the thesis is based on questionnaire studies focused on awareness of zoonoses and the issue of resistance and overuse of antibiotics. In total 479 questionnaires were evaluated. The survey findings may be equally described as interesting and positive, since the respondents had considerable awareness of the issue of antibiotic resistance.

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