Théorèmes de point fixe et principe variationnel d'Ekeland

Le principe de contraction de Banach, qui garantit l'existence d'un point fixe d'une contraction d'un espace métrique complet à valeur dans lui-même, est certainement le plus connu des théorèmes de point fixe. Dans plusieurs situations concrètes, nous sommes cependant amenés à considérer une contraction qui n'est définie que sur un sous-ensemble de cet espace. Afin de garantir l'existence d'un point fixe, nous verrons que d'autres hypothèses sont évidemment nécessaires. Le théorème de Caristi, qui garantit l'existence d'un point fixe d'une fonction d'un espace métrique complet à valeur dans lui-même et respectant une condition particulière sur d(x,f(x)), a plus tard été généralisé aux fonctions multivoques. Nous énoncerons des théorèmes de point fixe pour des fonctions multivoques définies sur un sous-ensemble d'un espace métrique grâce, entre autres, à l'introduction de notions de fonctions entrantes. Cette piste de recherche s'inscrit dans les travaux très récents de mathématiciens français et polonais. Nous avons obtenu des généralisations aux espaces de Fréchet et aux espaces de jauge de quelques théorèmes, dont les théorèmes de Caristi et le principe variationnel d'Ekeland. Nous avons également généralisé des théorèmes de point fixe pour des fonctions qui sont définies sur un sous-ensemble d'un espace de Fréchet ou de jauge. Pour ce faire, nous avons eu recours à de nouveaux types de contractions; les contractions sur les espaces de Fréchet introduites par Cain et Nashed [CaNa] en 1971 et les contractions généralisées sur les espaces de jauge introduites par Frigon [Fr] en 2000.The Banach contraction principle, which certifies that a contraction of a complete metric space into itself has a fixed point, is for sure the most famous of all fixed point theorems. However, in many case, the contraction we consider is only defined on a subset of a complete metric space. Of course, to certify that such a contraction has a fixed point, we need to add some restrictions. The Caristi theorem, which certifies the existence of a fixed point of a function of a complete metric space into itself satisfying a particular condition on d(x,f(x)), was later generalized to multivalued functions. By introducing different types of inwardness assumptions, we will be able to state some fixed point theorems for multivalued functions defined on a subset of a metric space. This is related to the recent work of French and Polish mathematicians. We were able to generalize some theorems to Fréchet spaces and gauge spaces such as the Caristi theorems and the Ekeland variational principle. We were also able to generalize some fixed point theorems for functions that are only defined on a subset of a Fréchet space or a gauge space. To do so, we used new types of contractions; contractions on Fréchet spaces introduced by Cain and Nashed [CaNa] in 1971 and generalized contractions on gauge spaces introduced by Frigon [Fr] in 2000

Digital Remembrance: Archives and the 100th Anniversaries of World War I

These presentations were part of panel at MARAC Buffalo in October of 2017. The title of the panel was Digital Remembrance: Archives and the 100th Anniversaries of World War I. The panel looked at using modern approaches to digitization and audience engagement in service of remembering WWI and those impacted by the war - families, volunteers and soldiers

Pratiques éco-alternatives : dimensions éthiques et symboliques du quotidien de la résistance

La récente recrudescence de l'activité et des revendications de groupes traditionnellement associés à la gauche politique oblige à reconsidérer la catégorie altermondialiste. Celle-ci n'arrive plus à couvrir la réalité d'une vaste mouvance sociale syncrétisant les idées antiautoritaires, écologistes et féministes et, plus généralement, l'héritage alternatif des années 1970. Cette recherche porte sur les pratiques quotidiennes et le mode de vie mis en œuvre par les personnes s'inscrivant dans cette nébuleuse alternative. Elle vise la documentation et l'analyse de ces pratiques d'un point de vue socio-anthropo-religiologique, dans leurs dimensions éthique, politique et symbolique et explore ce qui les lie à la quête de sens personnelle et collective, à l'espace-temps quotidien, à la socialité ainsi qu'à l'horizon symbolique qu'elles convoquent et construisent. Par le moyen de la théorisation ancrée, cette recherche permet de cerner les contours de ce qu'il y a lieu d'appeler la mouvance éco-alternative, mouvance qui s'exprime dans tous les aspects du quotidien, du plus intime au plus institutionnalisé. Cette mouvance prend la forme d'un mouvement d'insurrection personnelle qui, sur la base de certaines valeurs, se manifeste par des pratiques concrètes dont le sens est mutuellement négocié et partagé, pour en venir à générer un système symbolique intimement et collectivement intégré. Cette démarche aboutit dans la théorisation de la dynamique interne d'un authentique processus de changement social qui permet de considérer que la personne, sa volonté et sa capacité d'action sont les filtres par lesquels se reproduit ou non le système symbolique dont elle hérite culturellement. Ces éléments permettent de mieux comprendre comment l'action individuelle concertée sous la forme de pratiques partagées influence et transforme l'univers symbolique et à l'inverse, comment cet univers symbolique mutuellement constitué sert de cadre de référence à l'action individuelle socialement agissante. Tout le travail réflexif accompli dans ces pages mène à mieux saisir cette interrelation intime des actes individuels et des transformations collectives; il n'y aurait donc pas d'antagonisme entre le pouvoir de l'acte individuel dans l'espace-temps quotidien et la force de la mouvance collective concertée et organisée, entre les cheminements individuels et ceux des collectivités.\ud ______________________________________________________________________________ \ud MOTS-CLÉS DE L’AUTEUR : communauté de pratiques, quotidienneté, éthique, symbolique, altermondialisme, écologisme, anarchisme, changement social

CARIAA Working Paper no. 13

Includes abstract in FrenchTajikistan is affected by floods, droughts, hailstorms, avalanches, mudflows, and landslides, which negatively impact economic development and livelihoods. Climate researchers expect that future temperatures will continue to rise, leading to further melting of the country’s glaciers, and that rainfall variability and intensity will increase. Rural areas are expected to be most significantly affected, with women and children recognized as particularly vulnerable. The Government of Tajikistan’s ongoing Strategic Program for Climate Resilience focuses on enhancing institutional and technical capacities in climate change, while identifying the most critical climate change concerns as reduced water quality and availability and increased frequency of natural disasters

CARIAA Working Paper no. 9

Includes abstract in FrenchIn Ghana, the impacts of climate change, including rising sea levels and temperatures, and increasing rainfall variability, challenge the country’s efforts to realize its vision of inclusion and prosperity. The northern part of the country in particular, will require concerted adaptation efforts to reduce poverty and build resilience. The Government of Ghana has made efforts to recognize climate change as a risk in sectoral policies on water, agriculture, and energy; however, these policy documents contain few concrete actions. Key priorities include the development of the evidence base for adaptation through effective monitoring and evaluation, and strengthening capacity for civil society networks and subnational actors

A case of fatal idiosyncratic reaction to the designer drug 3,4-methylenedioxypyrovalerone (MDPV) and review of the literature

The stimulant designer drug 3,4-methylenedioxypyrovalerone (MDPV) was first synthesized by Boehringer Ingelheim in 1969 and introduced on the black market in 2006. Only a small number of fatal intoxication cases have been reported in the literature, all with significant blood MDPV concentrations. In this report, we describe one fatality attributed to an idiosyncratic reaction to MDPV. The victim displayed agitation, violent behavior and delirium followed by cardiac arrest. Hyperthermia was observed at the hospital. The MDPV cardiac and femoral blood concentrations were 6 ng/mL. The presence of excited delirium syndrome and MDPV, a drug with a pharmacology similar to cocaine, leads to the conclusion that the victim suffered a fatal adverse reaction to MDPV. This is the first published case of idiosyncratic reaction to MDPV

Spatial patterns of vegetation structure and structural diversity across edges between forested wetlands and upland forest in Atlantic Canada

Accepted versionForested wetlands are an integral but understudied part of heterogeneous landscapes in Atlantic Canada, although they are known to provide habitat for species at risk. Our objectives were to explore patterns of forest structure across edges between forested wetland and upland forest, to locate changes in vegetation structure and to assess multivariate relationships in vegetation structure. Our study sites were in temperate (Acadian) forested wetland landscapes. We sampled trees and recorded canopy cover every 20 m along 120-m-long transects. We estimated the cover of trees, saplings, shrubs in three height classes, Sphagnum, other bryophytes, lichens, graminoids, ferns, and forbs in contiguous 1 m × 1 m quadrats. We calculated structural diversity using the Shannon index and used wavelet analysis to assess spatial patterns. We found few clear patterns except for lower tree structural diversity at the edge of forested wetlands. Structural diversity was not a reliable measure for distinguishing forested wetland from upland forest. Forested wetlands are an integral part of many forested landscapes in Atlantic Canada, but their detection and differentiation from surrounding ecosystems can be difficult. Policy should err on the side of caution when mapping forested wetlands and include them in wetland protection

Multiscale habitat characterization of herbaceous Atlantic Coastal Plain Flora on lakeshores in Nova Scotia

Accepted VersionAtlantic Coastal Plain Flora (ACPF) are a group of plants mostly inhabiting lakeshores along the Atlantic coast of the United States, with disjunct populations in Nova Scotia and Ontario. To better define their ecological requirements, the main objective of this study was to determine the factors (biotic and abiotic habitat components) influencing ACPF communities (distribution, species abundance, and richness) at both the landscape and local scales. On 16 lakeshores in southwestern Nova Scotia, we characterized ACPF communities and habitat within 20 cm square contiguous quadrats distributed along 20 m transects (landscape scale) and in 5 m × 5 m grids (local scale). Performing redundancy analysis (n = 16 transects), we found that at the landscape scale, shoreline slope and shrub species distribution influenced the quantity of suitable habitat available for ACPF, with mineral shorelines supporting higher ACPF richness. Using spatial generalized linear mixed models (n = 3125 quadrats in five grids), we found that elevation, vegetation elements (shrubs, sundews, graminoids), and substrate type mostly influenced ACPF presence and abundance. ACPF also showed inter-specific differences in habitat preferences. Defining ACPF ecological requirements at both the landscape and local scales is important to guide conservation and management actions in Nova Scotia and throughout their North American range

understanding and tackling poverty and vulnerability in mountain livelihoods in the hindu kush himalaya

This chapter critically reviews the existing knowledge on livelihoods, poverty, and vulnerability in the Hindu Kush Himalaya (HKH). Development in mountain areas and the practices of people in these areas are uniquely conditioned by distinct characteristics that we term "mountain specificities". Some of these specificities—such as inaccessibility, fragility, and marginality—constrain development. Others—such as abundant biological diversity, ecological niches, and adaptation mechanisms—present development opportunities for mountain people

Study on the effect of Drill on Word Meaning on Reading Achievement

Abstract Not Availabl