Transmission tunnel assistée par défaut dans un détecteur infrarouge à multipuits quantiques

Session AffichesNational audienceOn étudie l'influence d'un défaut profond sur la transmission tunnel dans la zone à multipuits quantiques d'un photo-détecteur infrarouge. Dans le cadre d'un formalisme matriciel, le défaut est assimilé à une singularité de Dirac du potentiel

Traitement des adolescentes anorexiques par la thérapie familiale

De nombreuses publications et études scientifiques démontrent clairement l'interaction de multiples facteurs de risque associés aux troubles des conduites alimentaires, entre autres, l'anorexie nerveuse. Les chercheurs orientant leurs études sur les difficultés vécues par les adolescentes anorexiques et leurs familles s'entendent sur le fait que ce trouble résulterait de la combinaison de nombreux facteurs de risque tels que les facteurs personnels, familiaux, sociaux et environnementaux. Bien que cette problématique des dysfonctions alimentaires soit multifactorielle, les modèles d'intervention familiale proposés dans la littérature scientifique ciblent généralement un certain nombre de variables spécifiques omettant toutefois certaines données influentes ce qui restreint l'efficacité et la pertinence des interventions effectuées

La résistance du nom : Walter Benjamin et la liberté du langage

Commencer à lire Walter Benjamin constitue un défi en soi, car les nombreux thèmes qui composent son œuvre se portent mal à la « vue d’ensemble ». On voit souvent flotter des citations tirées de ses essais connus sur Kafka ou sur Brecht, ou encore le titre d’un essai populaire sur la reproductibilité technique de l’art, mais ces passe-partout ne lui rendent pas toujours justice. Ce mémoire tente de répondre de l’exigence que Benjamin lance à la philosophie : trouver dans une étude sur le langage (et dans le geste d’écrire) les ressources d’une lutte contre la violence invisible des mythes de notre culture dont nous devons débusquer la forme à même ses renouvellements perpétuels. En choisissant comme fil l’un des thèmes les plus connus de cet auteur, soit la perte d’expérience, et en prenant acte de la multiplicités des interprétations possibles, que ce soit celles de la théologie ou du matérialisme historique, il sera démontré que son concept de médium – et son rôle jusque-là inusité au sein des questions portant sur l’éthique – peut servir de levier à la transformation du concept de liberté. Même si ce terme n’apparaît pas souvent, ses occurences témoignent du souci vis-à-vis la posture que l’on doit adopter vis-à-vis son propre langage ou le langage de l’autre. Le premier chapitre amorcera la discussion par le biais d’une métacritique du concept du sujet transcendantal kantien, réalisée par l’explicitation de la relation que la raison entretient avec son langage, suivie de l’introduction du concept de médium qui ressort de son étude sur les premiers romantiques. Le deuxième chapitre sera l’occasion d’approfondir cette dernière relation à l’aide du rapport fondamental que Benjamin articule entre la philosophie et l’art. Sa théorie de la critique littéraire sera présentée en lien avec l’importance de la posture théologique présente au cœur de sa théorie de la traduction. Le troisième chapitre, portant sur son étude L’origine du drame baroque allemand, se fera le témoin du geste critique de Benjamin. À travers la présentation du contenu historique que l’œuvre met au jour, cette étude découvre l’origine de l’appauvrissement de l’expérience qui sonne le glas de la plénitude de son concept, justifiant à rebrousse-poil la posture éthique dans laquelle sa pensée philosophique s’engage.To start reading Benjamin constitutes a challenge in itself. It can be hard to grasp just what makes the variety of his topics part of the same philosophical quest. One often sees quotations from his work on well-known writers, such as Kafka or Brecht, or perhaps has heard the title of a very famous essay on the technological reproductibility of art. But these hardly make up for the depth of his work. This paper will try to answer for the demand his work imposed on philosophy: to find in the study of language (and the gesture of writing) the resources of its resistance against the invisible yet ubiquitous violence perpetrated by the myths of our culture, which we have to decipher in their endlessly mutating forms. By choosing as a starting point one of his well-known concern – the loss of experience – and by acknowledging different interpretations – whether it is seen from a theological or historical materialism stand point – it will be demonstrated that his concept of medium and the unusual role it takes within meditations of an ethical nature can be used as a lever for the transformation of the concept of freedom. Though this word might not appear very often in his work, when it does, it often has something to do with one’s own dealing with language, whether it is his or another langage. The first chapter will focus on his metacritic of Kant’s concept of the transcendental subject, carried out by the disclosure of the overlooked connection between reason and language. It will be followed by the introduction of the concept of medium that stems from his study on the first romantics. The second chapter will go deeper into the relationship between philosophy and art that ensues. His theory on literary criticism will be presented in relation to the importance of the theological stance that pertains to his theory on translation. By focusing on his work The Origin of German Tragic Drama, the third chapter will bear witness to his critical gesture. Through the presentation of the historical content of the work, this study discovers the very origin of the impoverishment of our experience and the difficulties of finding a concept worthy of its fullness, justifying in reverse the ethical stance his philosophical thinking engages in

Substrate binding to the inactive mutants of Streptomyces sp. N174 chitosanase: indirect evaluation from the thermal unfolding experiments

AbstractOligosaccharide binding to chitosanase from Streptomyces sp. N174 was indirectly evaluated from thermal unfolding experiments of the protein. Thermal unfolding curves were obtained by fluorescence spectroscopy in the presence of d-glucosamine oligosaccharides ((GlcN)n, n=3,4,5, and 6) using the inactive mutant chitosanase in which the catalytic residue, Glu22, is mutated to glutamine (E22Q), aspartic acid (E22D), or alanine (E22A). The midpoint temperature of the unfolding transition (Tm) of E22Q was found to be 44.4°C at pH 7.0. However, the Tm increased upon the addition of (GlcN)n by 1.3°C (n=3), 2.5°C (n=4), 5.2°C (n=5), or 7.6°C (n=6). No appreciable change in Tm was observed when (GlcNAc)6 was added to E22Q. The effect of (GlcN)n on the thermal stability was examined using the other protein, RNaseT1, but the oligosaccharide did not affect Tm of the protein. Thus, we concluded that the stabilization effect of (GlcN)n on the chitosanase results from specific binding of the oligosaccharides to the substrate binding cleft. When E22D or E22A was used instead of E22Q, the increases in Tm induced by (GlcN)6 binding were 2.7°C for E22D and 4.2°C for E22A. In E22D or E22A, interaction with (GlcN)6 seems to be partly disrupted by a conformational distortion in the catalytic cleft

De l'Abbittibbi-Témiskaming 4

Ouvrage contenant les études suivantes: Jean Laflamme, «Le Marquis de Vaudreuil et l'Abitibi-Témiscamingue. Première partie: 1718-1724». Marc Charron, «Présentation sommaire d'un colonisateur de l'Abitibi: Hector Authier». Benoît-Beaudry Gourd, «Les travailleurs miniers et l'implantation du syndicalisme dans les mines de l'Abitibi-Témiscamingue 1925-1950». Marcel Desharnais, «Vingt ans de colonisation sous le régime coopératif. Guyenne 1947-1967.» Isabelle Boucher, «Histoire d'une pionnière de Villebois». Francine Boucher, «La place des filles au Collège du Nord-Ouest». Jo Godefroid, Rôle de l'appartenance sociale du niveau socio-économique dans l'orientation, les résultats et les perceptions des étudiants du Collège du Nord-Ouest»

Land use history (1840–2005) and physiography as determinants of southern boreal forests

Land use history has altered natural disturbance dynamics, causing widespread modifications of the earth's forests. The aim of this study is to reconstruct a regional, spatially-explicit, fire and logging history for a large southern boreal forest landscape (6,050 km2) of eastern Canada. We then examined the long-term influence of land use history, fires, and physiographical gradients on the area's disturbances regimes, present-day age structure and tree species composition. Spatially-explicit fire (1820-2005) and logging (1900-2005) histories were reconstructed from forestry maps, terrestrial forest inventories and historical records (local newspapers, travel notes, regional historical reviews). Logistic regression was used to model the occurrence of major boreal tree species at the regional scale, in relation to their disturbance history and physiographical variables. The interplay of elevation and fire history was found to explain a large part of the present-day distribution of the four species studied. We conclude that human-induced fires following the colonization activities of the nineteenth and twentieth centuries have increased fire frequency and the dominance of fire-adapted species at lower elevations. At higher elevations, the low historical fire frequency has fostered the dominance of fire-sensitive species. Twentieth-century forestry practices and escaped settlement fires have generated a forest landscape dominated by younger forest habitats than in presettlement times. The expected increase of wildfire activity in North America's eastern boreal forest, in conjunction with continued forest management, could have significant consequences on the resilience of boreal forests

Site-directed Mutagenesis of Evolutionary Conserved Carboxylic Amino Acids in the Chitosanase from Streptomyces sp. N174 Reveals Two Residues Essential for Catalysis

The comparison of four sequences of prokaryotic chitosanases, belonging to the family 46 of glycosyl hydrolases, revealed a conserved N-terminal module of 50 residues, including five invariant carboxylic residues. To verify if some of these residues are important for catalytic activity in the chitosanase from Streptomyces sp. N174, these 5 residues were replaced by site-directed mutagenesis. Substitutions of Glu-22 or Asp-40 with sterically conservative (E22Q, D40N) or functionally conservative (E22D, D40E) residues reduced drastically specific activity and kcat, while Km− was only slightly changed. The other residues examined, Asp-6, Glu-36, and Asp-37, retained significant activity after mutation. Circular dichroism studies of the mutant chitosanases confirmed that the observed effects are not due to changes in secondary structure. These results suggested that Glu-22 and Asp-40 are directly involved in the catalytic center of the chitosanase and the other residues are not essential for catalytic activity

Management of Esophageal Carcinoma Associated with Cirrhosis: A Retrospective Case-Control Analysis

Objectives. Esophageal carcinoma and cirrhosis have the overlapping etiologic factors. Methods. In a retrospective analysis conducted in 2 Breton institutions we wanted to asses the frequency of this association and the outcome of these patients in a case-control study where each case (cirrhosis and esophageal cancer) was paired with two controls (esophageal cancer). Results. In a 10-year period, we have treated 958 esophageal cancer patients; 26 (2.7%) had a cirrhosis. The same treatments were proposed to the 2 groups; cases received nonsignificantly different radiation and chemotherapy dose than controls. Severe toxicities and deaths were more frequent among the cases. At the end of the treatment 58% of the cases and 67% of the controls were in complete remission; median and 2-year survival were not different between the 2 groups. All 4 Child-Pugh B class patients experienced severe side effects and 2 died during the treatment. Conclusions. This association is surprisingly infrequent in our population! Child-Pugh B patients had a dismal prognosis and a bad tolerance to radiochemotherapy; Child-Pugh A patients have the same tolerance and the same prognosis as controls and the evidence of a well-compensated cirrhosis has not modified our medical options