111 research outputs found

    Évaluation du comportement cinĂ©tique et du risque associĂ© aux glissements de terrain rocheux actifs Ă  l'aide de mesures de surveillance : le cas du glissement de Gascons, GaspĂ©sie, Canada

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    Un glissement de terrain actif menace l’intĂ©gritĂ© de l’unique chemin de fer qui relie la ville de GaspĂ© au reste du QuĂ©bec. Il est impĂ©ratif de comprendre les mĂ©canismes qui contrĂŽlent cette instabilitĂ© afin d’augmenter la sĂ©curitĂ© de ce tronçon de la voie ferrĂ©e. Un systĂšme d’instrumentation du massif fĂ»t mis en place en 2009 pour caractĂ©riser le glissement, dĂ©crire son comportement cinĂ©tique, proposer des scĂ©narios de rupture et Ă©valuer le risque. Cette thĂšse de doctorat rassemble trois articles portant sur ces aspects. Ce document se veut aussi un moyen de partager les connaissances acquises sur l’instrumentation d’un massif rocheux, ainsi que la contribution de ces instruments Ă  un systĂšme de prĂ©diction d'un Ă©vĂ©nement potentiellement dangereux. Le glissement de Gascons est une rupture diĂšdre asymĂ©trique de 410 000 mÂł. Il glisse sur le litage de la formation sĂ©dimentaire de l’Anse-Ă -Pierre-Loiselle, une unitĂ© de transition composĂ©e majoritairement de calcilutite Ă  nodules. Le glissement est divisĂ© en blocs par l’étude des linĂ©aments et des fractures. De plus, des surfaces de rupture intermĂ©diaires sont reconnues. Le suivi in-situ couplĂ© au suivi satellitaire mesure des dĂ©placements variant de 6 Ă  111 mm/an selon les secteurs. L’interaction entre le glissement et les facteurs environnementaux, comme la prĂ©sence d’eau, est complexe, mais bien prĂ©sente. La nappe phrĂ©atique se situe gĂ©nĂ©ralement tout juste sous la surface de rupture dans la majoritĂ© du glissement, mais les prĂ©cipitations et la fonte des neiges augmentent les pressions d’eau et le niveau Ă©quivalent de l’eau sous-terraine augmente au-dessus de la surface de rupture dans le secteur amont du glissement. Une analyse quantitative du risque est effectuĂ©e en adaptant la mĂ©thodologie proposĂ©e par Fell et al. (2005). Des scĂ©narios de ruptures sont dĂ©terminĂ©s et l’effet domino d’une rupture partielle est Ă©tudiĂ©e avec un arbre d’évĂšnements qui permet d’associer des probabilitĂ©s relatives. La probabilitĂ© spatio-temporelle minimale sans prĂ©diction est dĂ©finie afin de caractĂ©riser le risque associĂ© Ă  un glissement actif sans prĂ©dire la rupture. Enfin, cette recherche contribue Ă  amĂ©liorer la comprĂ©hension thĂ©orique des mĂ©canismes associĂ©s au domaine de la post-rupture, par exemple le rĂŽle de l’eau dans la progression d’une instabilitĂ© active.An active rockslide threatens the integrity of the single railway connecting the town of GaspĂ© to the rest of Quebec. A better understanding of the mechanisms controlling this instability is needed to increase the safety of this section of the track. An instrumentation system was set up in 2009 to characterize the rockslide, describe its kinematic behaviour, propose failure scenarios and assess the risk. This thesis presents three papers covering these aspects. This document is also meant to share knowledge on the instrumentation of a very slow rockslide, and the contribution of these instruments to an early warning system of a potentially dangerous event. The Gascons slide is a 410 000 mÂł asymmetrical wedge failure. It slides on the bedding of the sedimentary Formation of Anse-Ă -Pierre Loiselle, which is a transition unit mostly made up of nodulous calcilutite. The slide is divided into blocks by the study of lineaments and fractures and intermediate sliding surfaces are identified. In-situ monitoring, coupled with satellite monitoring, shows displacements varying from 6 to 111 mm/yr across different sectors. The slide is sensitive to environmental forces, such as groundwater level variations, but the interactions are complex. The water table is generally right below the sliding surface, but rainfall and snowmelt increase groundwater pressure, and the equivalent water level is then above the sliding surface in the uphill part of the slide. A quantitative risk analysis is carried out by adapting a methodology proposed by Fell et al. (2005). Failure scenarios are determined and the domino effect of a partial collapse event is evaluated by constructing an event tree, which enables the determination of relative probabilities. The concept of minimum temporal spatial probability without forecasting is defined to characterize the minimal risk associated with an active slide without predicting the rupture. Finally, this work contributes to improving the theoretical understanding of the mechanisms associated with the post-failure stage, for example the role of water in the progression of an active instability

    Bush et l'évangélisme de la peur : l'Iran, « grand satan » dans la croisade contre la terreur

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    Ce mĂ©moire s'intĂ©resse Ă  la reprĂ©sentation de l'Iran par l'administration George W. Bush, telle que vĂ©hiculĂ©e par la rhĂ©torique officielle de cette administration. Par une analyse de discours poststructuraliste portant sur le lexique, les tropes et les liens intertextuels employĂ©s par le prĂ©sident et la Maison-Blanche dans les communications orales et Ă©crites officielles, et en particulier celles publiĂ©es durant le deuxiĂšme mandat de cette administration (2005-2009), le mĂ©moire mettra en Ă©vidence trois modes de reprĂ©sentation de l'Iran: (1) comme État soutenant le terrorisme; (2) comme État dĂ©diĂ© Ă  la prolifĂ©ration et Ă  l'utilisation d'armes de destruction massive; et (3) comme État tyran. Le mĂ©moire soutiendra que, pris ensembles, ces trois modes de reprĂ©sentation ou discours contribuent Ă  imposer une identitĂ© Ă  l'État iranien, de mĂȘme qu'Ă  constituer ce dernier comme ennemi des États-Unis et comme menace Ă  la sĂ©curitĂ© nationale amĂ©ricaine et Ă  la paix mondiale. En outre, le mĂ©moire arguera que ces discours sur l'Iran concourent Ă  consacrer une identitĂ© nationale positive pour l'AmĂ©rique, en reprĂ©sentant cette derniĂšre comme une puissance exceptionnelle ayant la destinĂ©e manifeste de rĂ©pandre les valeurs libĂ©rales dans le monde. Le mĂ©moire soutiendra que ces discours sur l'Iran et les États-Unis participent, par extension, Ă  consolider une hiĂ©rarchie morale amĂ©ricaine du monde, fortement genrĂ©e et racialisĂ©e, au sein de laquelle les États-Unis occupent la place prĂ©dominante. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : IdentitĂ© nationale, Analyse de discours, États-Unis, George W. Bush, RĂ©publique islamique d'Iran

    Portrait de la situation en matiĂšre de recherche scientifique pour l’économie sociale du Canada

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    Ce rapport prĂ©sente les premiers rĂ©sultats d’une veille sur la recherche scientifique en Ă©conomie sociale au Canada. Nous y avons rĂ©pertoriĂ© divers organismes de recherche qui traitent de l’économie sociale et coopĂ©rative. Les critĂšres de sĂ©lection Ă©tant la scientificitĂ© de la production et son importance en volume, nous avons pu rĂ©pertorier prĂšs de vingt-cinq organismes. Toutefois, cette recherche n’est pas exhaustive puisque nous n’avons pas procĂ©dĂ© Ă  une enquĂȘte systĂ©matique de tous les organismes de recherche sur le sujet au Canada. Trois types d’organismes de recherche y ont Ă©tĂ© rĂ©pertoriĂ©s soit, les centres universitaires ; les associations scientifiques, partenariales et sectorielles ; les organismes gouvernementaux. Chaque organisme est classĂ© sous forme de fiche qui comprend ses coordonnĂ©es, une courte prĂ©sentation, les thĂ©matiques qui y sont traitĂ©es, les types de publications et les sources de financement. Ce rapport est le deuxiĂšme de sa sĂ©rie. Le premier a Ă©tĂ© publiĂ© en mars 2005 (Cahier R-2005-03).This report presents a first outlook of the scientific research on the social economy in Canada. We list diverse research organizations that work on the social and co-operative economy. Selection criteria being the scientific aspect of the production and the importance of it in terms of volume, we have been able to identify almost twenty-five organizations. Nevertheless, this research is not exhaustive, since we have not gone through with a systematic enquiry of all the research organizations working on the social economy in Canada. Three types of research organizations have been listed: university centres; scientific, partnership and sector associations; government organizations. Each organization is classified as a record that includes the mail and electronic addresses, a short presentation, the themes that are developed, the types of publications and the financing sources. This report is the second of its series. The first one was published in March, 2005 (Working Paper R-2005-03)

    Vulnérabilité et transition : exploration de la transition à la vie adulte de jeunes vulnérables à partir de leur récit de vie

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    La façon dont les jeunes vivent leur pĂ©riode de transition Ă  la vie adulte (TVA) a beaucoup changĂ© depuis les annĂ©es 1950, suivant les changements ayant eu lieu au plan sociohistorique. La proposition thĂ©orique de l'adulte Ă©mergent (AE) a Ă©tĂ© formulĂ©e au dĂ©but des annĂ©es 2000 afin de dĂ©crire comment les jeunes naviguent dans le contexte actuel pour organiser leur entrĂ©e Ă  la vie adulte. La proposition thĂ©orique de l'AE est utilisĂ©e dans de nombreuses Ă©tudes, mais de plus en plus d'auteurs remettent en question sa reprĂ©sentativitĂ© chez les jeunes plus vulnĂ©rables; leur accĂšs plus limitĂ© aux ressources ne leur permettrait pas de repousser leur entrĂ©e Ă  la vie adulte au mĂȘme titre que les jeunes plus privilĂ©giĂ©s. La prĂ©sente Ă©tude a ainsi explorĂ© la rĂ©alitĂ© de 12 participants ĂągĂ©s de 18 Ă  30 ans qui se prĂ©sentent comme vulnĂ©rables afin d'Ă©valuer dans quelle mesure la proposition thĂ©orique de l'AE permet de bien soutenir les individus plus vulnĂ©rables durant la TVA. Les rĂ©cits de vie des participants ont Ă©tĂ© analysĂ©s selon une mĂ©thode d'analyse thĂ©matique inductive et dĂ©ductive afin de dĂ©gager les thĂšmes utilisĂ©s par ceux-ci pour dĂ©crire leur expĂ©rience en TVA. Les rĂ©sultats de l'Ă©tude permettent de dĂ©gager deux principaux constats Ă  propos de la TVA des jeunes plus vulnĂ©rables qui ne sont pas dĂ©fendues par les travaux d'Arnett: ces jeunes seraient fortement motivĂ©s par la construction d'un Ă©tat de stabilitĂ© et l'engagement constituerait un processus central dans leur dĂ©veloppement identitaire. Ces rĂ©sultats appellent Ă  ce que les dĂ©cideurs et les intervenants psychosociaux considĂšrent le rĂŽle de la stabilitĂ© et de l'engagement identitaire dans l'organisation du soutien offert aux jeunes plus vulnĂ©rables afin de favoriser que cette population Ă  risque traverse, voire prospĂšre, durant cette pĂ©riode dĂ©veloppementale dĂ©terminante.The way young people experience their transition to adulthood (TA) has changed significantly since the 1950s, following the changes that have taken place at the socio-historical level. The emerging adult (EA) theoretical proposition was formulated in the early 2000s to describe how today's young people organize their entry into adulthood. The EAs theoretical proposition is used in many studies, but a growing number of authors question its representativeness among more vulnerable youth; their more limited access to resources would not allow them to delay their entry into adulthood to the same extent as more privileged youth. The present study thus explored the realities of 12 participants aged 18-30 who identified themselves as vulnerable in order to assess how well the theoretical proposition of EA supports more vulnerable individuals during the TA. The participants' life stories were analyzed using an inductive and deductive thematic analysis method in order to identify the themes they used to describe their experience in TA. The results of the study allowed to identify two main findings about the TA of more vulnerable youth that are not supported in Arnett's work: these youth would be strongly motivated by the construction of a state of stability and commitment would be a central process in their identity development. These results call for policy makers and psychosocial practitioners to consider the role of stability and identity commitment in organizing support for more vulnerable youth, thereby helping them navigate and even thrive during this critical developmental period

    Le rappel stimulĂ© pour mieux comprendre les stratĂ©gies de lecture d’élĂšves du primaire Ă  risque et compĂ©tents

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    Cet article dĂ©crit de quelle façon la mĂ©thode du rappel stimulĂ©, utilisĂ©e aprĂšs une tĂąche de comprĂ©hension d’un texte informatif, amĂšne une meilleure connaissance des stratĂ©gies de lecture de trois Ă©lĂšves de sixiĂšme annĂ©e ayant des portraits de lecteur diffĂ©rents. Les explicitations et commentaires rappelĂ©s de ces Ă©lĂšves portant sur leurs actions et pensĂ©es permettent de dĂ©gager leurs procĂ©dures pour comprendre un texte, en utilisant ou non des stratĂ©gies efficaces, qui elles-mĂȘmes se rĂ©fĂšrent Ă  des connaissances diffĂ©rentes. Les contributions et les limites du rappel stimulĂ© utilisĂ©es auprĂšs d’élĂšves sont discutĂ©es. AbstractThis article describes how a stimulated recall method used after a reading comprehension task contributes to a better understanding of the strategies employed by three different Grade 6 readers. After reading an informative text, the students explained and commented on their own actions and thoughts, exposing how they proceeded to understand their readingand whether or not they used strategies based on multiple knowledge types. Contributions and limits of the stimulated recall method for students are discussed.

    Brief communication: On direct impact probability of landslides on vehicles

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    Abstract. When calculating the risk of railway or road users of being killed by a natural hazard, one has to calculate a temporal spatial probability, i.e. the probability of a vehicle being in the path of the falling mass when the mass falls, or the expected number of affected vehicles in case such of an event. To calculate this, different methods are used in the literature, and, most of the time, they consider only the dimensions of the falling mass or the dimensions of the vehicles. Some authors do however consider both dimensions at the same time, and the use of their approach is recommended. Finally, a method considering an impact on the front of the vehicle is discussed

    By Us and For Us: A Story of Early Childhood Development Systems Change and Results in a Rural Context

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    Since 2007, the Neil and Louise Tillotson Fund — a donor-advised fund of the New Hampshire Charitable Foundation — has invested in early childhood development in Coös County — New Hampshire’s largest and most rural and economically disadvantaged county. Community providers from a range of disciplines formed strong professional relationships and agreed on common goals and evidence-based strategies to improve services for children and families. This article describes how local community members joined forces with the fund to create an integrated early childhood development system for Coös’ children and families. It provides background on the investment and initiative strategy, summarizes key results, and outlines lessons for funders and others pursuing systems change efforts in early learning, in rural areas, or more broadly. With increasing interest in strategies to promote childhood resilience, school readiness, and community revitalization, Coös County’s rural story of relationship and community systems change can inform the field

    The Prostanoid 15-Deoxy-D 12,14 -Prostaglangin-J 2 Reduces Lung Inflammation and Protects Mice Against Lethal Influenza Infection

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    Background. Growing evidence indicates that influenza pathogenicity relates to altered immune responses and hypercytokinemia. Therefore, dampening the excessive inflammatory response induced after infection might reduce influenza morbidity and mortality. Methods. Considering this, we investigated the effect of the anti-inflammatory molecule 15-deoxy-D 12,14 -prostaglandin J 2 (15d-PGJ 2 ) in a mouse model of lethal influenza infection. Results. Administration of 15d-PGJ 2 on day 1 after infection, but not on day 0, protected 79% of mice against lethal influenza infection. In addition, this treatment considerably reduced the morbidity associated with severe influenza infection. Our results also showed that treatment with 15d-PGJ 2 decreased influenza-induced lung inflammation, as shown by the diminished gene expression of several proinflammatory cytokines and chemokines. Unexpectedly, 15d-PGJ 2 also markedly reduced the viral load in the lungs of infected mice. This could be attributed to maintained type I interferon gene expression levels after treatment. Interestingly, pretreatment of mice with a peroxisome proliferator-activated receptor gamma (PPARc) antagonist before 15d-PGJ 2 administration completely abrogated its protective effect against influenza infection. Conclusions. Our results demonstrate for the first time that treatment of mice with 15d-PGJ 2 reduces influenza morbidity and mortality through activation of the PPARc pathway. PPARc agonists could thus represent a potential therapeutic avenue for influenza infections
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