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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.
1

Stress oxydatif, inflammation vasculaire et métalloprotéinases : étude in vitro sur un modèle de coculture

Bernard, Yohann 08 October 2008 (has links)
Au cours de l’athérosclérose, l’invasion de la paroi vasculaire par les leucocytes conduit à l’inflammation de ce tissu et à l’établissement d’un stress oxydatif. Ce travail aborde les effets du stress oxydatif et les effets d’interactions potentielles entre un modèle de neutrophiles (?HL60) et des cellules endothéliales (HCAEC) ou musculaires lisses (HCSMC) de coronaires humaines sur les métalloprotéinases (MMPs) cellulaires et la mobilité des ?HL60. Au cours des passages, la lignée promyélocytaire HL60, différenciée en modèle de neutrophiles ?HL60, subit des variations d’expression et de production de MMP9 et de ses propriétés de mobilité. Les espèces réactives de l’oxygène (ERO) d’origine biochimique ou cellulaire ne modifient pas l’activité MMP2 ou MMP9 des HCAEC et HCSMC. Il n’y a pas modification des activités MMPs en coculture ?HL60/HCAEC mais stimulation de l’activité MMP9 en coculture ?HL60/HCSMC. Les HCSMC stimulent les capacités migratoires et favorisent la réponse invasive des ?HL60 au N-formyl-L-Méthionyl-L-Leucyl-L-Phénylalanine. Les enzymes antioxydantes ont peu d’effet sur la mobilité, stimulent expression et production de MMP9 des ?HL60 et semblent diminuer l’effet stimulant des HCSMC sur la production de MMP9 par ?HL60. Les HCSMC expriment et/ou sécrétent certains cytokines (IL8, IL6, IL1?, CCL2, CXCL12) impliquées dans l’athérosclérose. En conclusion, l’interaction ?HL60/HCSMC entraîne une augmentation de production de MMP9, modulée par les ERO, et une stimulation de mobilité des ?HL60. Les cytokines inflammatoires impliquées dans l’athérosclérose et exprimées par les HSCMC sont des acteurs potentiels dans la réponse sécrétoire et/ou migratoire des ?HL60. / During atherosclerosis leucocytes invade the vascular wall, inducing inflammation and production of oxidative stress by reactive oxygen species (ROS). We tested the effects of an oxidative stress and/or potential interactions between a neutrophil model (?HL60) and human coronary endothelial (HCAEC) or smooth muscle (HCSMC) cells, on ?HL60 mobility and production and activity of cellular metalloproteinases. Cell passaging of the promyelocytic HL60 cell line, differentiated by DMSO in a neutrophil model (?HL60), induces variations in cell mobility and production of MMP9. ROS from biochemical or cellular sources did not modify MMP2 or MMP9 activity in HCAEC or HCSMC. There is no modification of MMPs activities in ?HL60/HCAEC cocultures, but stimulation of ?HL60 MMP9 activity in ?HL60/HCSMC cocultures. Basal migration capacities and N-formyl-L-Methionyl-L-Leucyl-L-Phenylalanine -stimulated invasion abilities of ?HL60 increase in presence of HCSMC. Antioxidant enzymes barely change ?HL60 mobility, increase expression and production of ?HL60 MMP9 and seem to reduce the stimulating effect of HCSMC on ?HL60 MMP9 production. HCSMC also express and/or secrete some cytokines (IL8, IL6, IL1?, CCL2, CXCL12) implicated in atherosclerosis. In conclusion, interactions between ?HL60 and HCSMC induce an increase in MMP9 secretion, which is modulated by ROS, and a stimulation of ?HL60 mobility. Expression by HCSMC of inflammatory cytokines implicated in atherosclerosis allows to identify potential candidates responsible for the secretory and/or migratory response of ?HL60.
2

History and Responsibility: An Ecumenical Response to Migration in the United States

Hein, Aimee Allison January 2021 (has links)
Thesis advisor: Kristin E. Heyer / This dissertation in the area of Christian migration ethics focuses on expanding beyond the communitarian and cosmopolitan frameworks that often dominate migration ethics in order to respond more adequately to the historic and present realities that shape migration patterns, policy, and discourse. This project grounds itself particularly in accounts of the history of the United States from the perspective of Indigenous and Latinx people, concluding that the dominant historical narrative operating in the United States is inadequate for informing ethical thought and serves largely to uphold a status quo that does not protect all people. Its thesis argues that a responsibility ethic, rooted in biblically informed reparative justice, offers a way forward that is especially helpful for informing Christian communities in their responses to migration in the United States. This builds on the work of theologians who have begun to forge a more relational “third way” of thinking about migration that focuses less on debates between human rights and nation sovereignty and more on how we actually relate to each other as citizens and migrants. Chapter one outlines the state of the question. After grounding the conversation in philosophical theory, the chapter considers communitarian and cosmopolitan perspectives on three major themes in Christian migration ethics: Christian anthropology, Christian views on the state, and the law and scripture. Chapter two maps the development of myths and practices in U.S. history in order to illustrate how they have shaped U.S. foreign policy, immigration policy, and discourse. This chapter pays particular attention to how these myths and practices developed in connection to the removal of Indigenous peoples from their land. Chapter three draws on the work of H. Richard Niebuhr and Charles Curran in order to propose a responsibility ethics framework. This is underscored by reparative justice, framing the work of concrete repair as consistent with the radical love of Jesus and integral to the Kin-dom of God. Chapter four provides a bridge between this conceptual work and the practical proposals of chapter five by considering how the work of the church is framed and directed by the relationship between Christology and ecclesiology. This chapter pays particular attention to the Christological and ecclesiological contributions of Indigenous and Latinx theologians. Chapter five concludes with proposals for how Christian communities can live out the ecclesiological vision of chapter four and foster more just relationships with migrants. It does this primarily by considering four case studies that highlight concrete examples of how the themes outlined in chapter four might be lived out. / Thesis (PhD) — Boston College, 2021. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Theology.
3

University enrollment and geographical mobility : the case of Sweden /

Eliasson, Kent, January 2001 (has links)
Licentiatavhandling (sammanfattning) Umeå : Umeå universitet, 2001. / Härtill 2 uppsatser.
4

The securitisation of migration : towards an understanding of migration policy changes in the 1990s ; the case of Sweden /

Abiri, Elisabeth. January 2000 (has links) (PDF)
Univ., Diss.--Göteborg, 2000.
5

Etude de la migration des joints de grain mixtes flexion-torsion dans le Ni par dynamique moléculaire / Study of mixted (tilt-twist) grain boundaries migration in Ni using molecular dynamics

El omari, Zakaria 06 December 2018 (has links)
Les innovations récentes concernant les matériaux reposent beaucoup sur l’ajout et le contrôle d’interfaces. Cela est vrai pour les matériaux cristallins massifs incontournables pour les applications type structure, mais aussi pour les matériaux fonctionnels, micro-objets, ou les matériaux nanostructurés. Parmi ces interfaces il y a les joints de grains (JdGs) qui sont définis comme la frontière délimitant deux grains dont les orientations cristallographiques sont différentes. Les joints de grains contribuent fortement aux propriétés macroscopiques des matériaux. Le travail réalisé est une contribution à l’étude du comportement des joints lors de traitements thermomécaniques induisant leur mobilité. On parle de migration. En effet, Pour certains chargements thermo-mécaniques, les joints de grains (JdG) migrent dans les polycristaux métalliques. Malgré une littérature abondante sur le sujet, la compréhension du comportement collectif des dislocations et des JdG reste partielle au moins à l’échelle macroscopique. Ceci est dû, d’une part, au fait que plusieurs forces motrices sont actives simultanément dans les expériences sur polycristaux : (i) la tension de surface d’un joint courbé (ii) le différentiel d’énergie élastique pour les matériaux anisotrope élastiquement et (iii) enfin, la dernière force motrice est l’origine du couplage plasticité-migration. D'autre part, la mobilité des interfaces est intimement liée à leur structure atomique. Le présent travail se propose d’étudier théoriquement par simulation atomistique la migration en lien avec la structure des JdG. Des simulations de migration de JdG par dynamique Moléculaire, sous l’action d’une force motrice synthétique, sont réalisées. Une large variété de JdG, représentée par des bicristaux de Nickel, est étudiée. La mobilité des JdG est discutée en particulier pour différents plans du JdG et températures. A travers cette étude,trois caractères vis-à-vis de la température ont été observés : caractère thermoactivé, caractère athermique, et caractère antithermique. A ces caractères s’ajoutent d'autres comportements variant avec la température. Les simulations ont permis aussi l’identification de quelques mécanismes élémentaires de migration pour des JdG simples. Les JdG présentant une migration par formation de marche ou de disconnections ont été étudiés par la suite par la méthode Nudged Elastic Band. Cette méthode a permis de déterminer le chemin de minimum énergie lors de la migration. L’évolution du joint de grains lors de sa migration montre la nucléation et le déplacement des marches, identifiées comme des disconnections. / Recent innovations in materials rely heavily on the addition and control of interfaces.This is true for massive crystalline materials that are essential for structural applications, but also for functional materials, micro-objects, or nanostructured materials. Among these interfaces are the grain boundaries (GBs) which are defined as the boundary delimiting two grains with different crystallographic orientations.Grain boundaries strongly contribute to the macroscopic properties of materials. The work done is a contribution to the study of the behavior of GBs during thermomechanical treatments inducing their mobility. We are talking about migration. Indeed, during a thermomechanical loading, grain boundaries (GB) generally migrate through polycrystalline samples. Despite an extensive literature on the subject, understanding the collective behavior of dislocations and GB remains partial, at least on the macroscopic scale. This is due, firstly, to the fact that several driving forces are active simultaneously during the experiments on polycrystals : (i) the surface tension of a curved boundary (ii) the differential elastic energy for elastically anisotropic materials, and finally (iii) the coupling between plasticity and migration. On the other hand, the mobility of such interfaces is closely related to their atomic structure.Simulations of GBs migration by Molecular dynamics, under the action of asynthetic driving force, are carried out. A wide variety of GBs, represented by nickel bicristals, is studied. GB mobility is first discussed for various GB planes and temperatures. Through this study, three characteristics with respect to temperature were observed : thermally activated character, athermic character, and antithermal character. To these characters is added other behaviors varying with the temperature.The simulations also allowed the identification of some elementary migration mechanisms for basic GBs. GBs with step migration or disconnection migration were studied by the Nudged Elastic Band method. This method allowed determiningt he path of minimum energy (MEP) during the migration. The evolution of the grain boundary during its migration shows the nucleation and the displacement of the steps, identified as disconnections.
6

Socio-economic differentiation and selective migration in rural and urban Sweden /

Hjort, Susanne, January 2009 (has links)
Diss. (sammanfattning) Umeå : Umeå universitet, 2009. / Härtill 4 uppsatser.
7

Research in motion: patterns of large-scale migration in dragonflies and birds / Patterns of large-scale migration in dragonflies and birds

Matthews, John Holley, 1968- 29 August 2008 (has links)
The work I present here can be broadly described as focusing on the spatial, temporal, and ecological basis to patterns of movement by highly vagile organisms. From this perspective, the differences between chapters are matters of scale: community versus population ecology, and movement by thousands of birds through two localities versus a study of a single invertebrate species crossing North America. Animal movement over large scales has proven difficult to study throughout the history of biology. Proximal challenges have largely reflected practical problems with observing spatial displacement in individual organisms. Population-level evolutionary and ecological analyses -- ultimate explanations for movement -- depend on solutions to those proximal challenges. Here, I have tried to interweave both proximal and ultimate approaches. Large-scale movement also presents challenges from a conservation perspective. The conservation implications of the final chapter are immediately applicable to avian researchers and resource managers. In contrast, understanding why and how Anax junius Drury (Odonata: Aeshnidae) is moving across North America does not have such direct conservation implications. The species is not endangered, nor have threats to its range or behavior been suggested. My interest instead grew from the need for a model system to explore aquatic invertebrate conservation as well as the practical difficulties of studying long-distance migrants of all kinds, invertebrate and vertebrate. These chapters thus form a whole through their focus on determining how and why organisms move over large spatial scales and the connection of that behavior to habitat. Many species move great distances during individual lifetimes. Threats from land-use change, habitat fragmentation, and climate shifts will all have -- are already having -- impacts on many species. We need accurate, inexpensive, and effective tools to be able to count, compare, detect, define, delineate, and explain patterns of movement. I have endeavored to improve a few of these tools and, if possible, provide a few new examples and explanations grounding that movement.
8

La migration féminine précaire, lieu d’expérience d’un sujet culturel : Dynamiques formatives et (re)constructions identitaire. / Feminine precarious migration as a place of experience for a cultural subject : education dynamics and identity (re)constructions

Trifanescu, Letitia 09 December 2014 (has links)
Ce travail interroge les parcours de migration féminine précaire en tant que lieux d’expérience, de formation et de reconstruction de soi. Il s’intéresse aux dynamiques (trans)formatives de l’individu, auxquelles il associe l’émergence de postures de sujet et, plus précisément, d’un sujet culturel. Notre réflexion se situe dans le cadre d’une épistémologie centrée sur l’individu et ses espaces socioculturels et politiques d’action et de construction de soi. Nous avons donc fait appel à la recherche biographique en éducation, ainsi qu’à la perspective sociologique emmenée par l’Ecole de Chicago. La méthodologie qualitative de recueil et d’analyse des données s’y est inspirée et nous avons accordé la priorité à la parole singulière traduisant la migration en tant qu’expérience subjective. Cela nous a permis d’appréhender les parcours migratoires précaires en tant que projets de soi où le culturel participe à des processus de transformation du sujet, d’adaptation et d’apprentissage, mobilisés et organisés autour d’une revendication de pouvoir d’agir. / This work aims to study feminine precarious migration paths as places of experience, of learning and self reconstruction. It takes interest in individual transformation dynamics to which it associates the emergence of subjective postures and, more precisely, those of a cultural subject. Our intention relies on an epistemology focused on the individual and its socio-cultural and political spaces of action and self construction. We have thus chosen the biographical research in education as well as the sociological perspective of The Chicago School. They have brought on a qualitative methodology of data collection and analysis, helping us to focus on singular speeches, expressing migration as a subjective experience. Precarious migration paths thus appear as projects of self, where the cultural takes part in the subject’s process of transformation, adaptation and learning, mobilized and organized around a claim of power.
9

African rural-urban migration in South Africa : Empangeni Richards bay area

Gcabashe, Lindelihle Nhlakanipho January 1995 (has links)
A dissertation submitted to the Faculty of Arts in the Department of Sociology for the fulfilment of the requirements of the degree MASTER OF ARTS at the UNIVERSITY OF ZULULAND, 1995. / The study deals with African rural urban migration in Empangeni Richards Bay area, where the concern is on the people already in the towns. The purpose of this investigation is to attempt to come up with some possible remedies to the problem of rural-urban migration in South Africa. Therefore, the aims of the study were the following: To discover the reasons for the movement from rural to urban. To discover to what extent are the migrants integrated to their new environment. To get the perceptions of the migrants about the whole process of rural-urban migration. To find out ways and means to alleviate problems encountered by migrants. The conceptual framework of the study is derived from various theories of migration, and the impact on problems encountered by migrants. The population of the study comprises of the heads of the families. The sample which was drawn from the population was 25 subjects from each area, i.e, Empangeni and Richards Bay. The survey method was used to collect data in this study, and two research instruments were used viz. interviews and questionnaires. Ethical implications: consent from the subj ects was obtained after the purpose of the study had been fully , explained including what would happen to the results, and how would the subjects benefit from the findings of the study. The analysis of data was both qualitatively and quantitatively. Qualitative analysis was done to verify data obtained quantitatively. In the light of the findings of the study the investigator offered several recommendations and suggestions. / The Educational Opportunities Council (EOC)
10

Qing ling yi qian Taiwan zhi Zhongguo yi min

Jiang, Shusheng. January 1900 (has links)
Thesis (M.A.)--Ssu li Chung-kuo wen hua hsueh yuan. / Reproduced from typescript. Bibliography: leaves 107-115.

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