Spectroscopie et imagerie par résonance magnétique du cerveau : accident cérébrovasculaire ischémique et maladie d'Alzheimer

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

« Dérapage » ou remise en cause de l’institution universitaire

Selon nous, Arnaud Mercier décrit avec beaucoup d’exactitude la transformation que subit aujourd’hui la figure du professeur universitaire. Cela dit, il faut poser la question du sens de la transformation de l’Université : s’agit-il d’un « dérapage » ou est-ce la notion même d’institution universitaire qui fait l’objet d’une remise en question ? L’institution universitaire suppose une dialectique entre formes objectives et subjectivité ; en ce sens, elle illustre au mieux la dynamique propre à la modernité. Or c’est précisément cette dialectique qui est remise en question par la soumission de l’Université à des processus qui lui sont externes, qui entendent substituer à cette dialectique la faculté d’adaptation à des contraintes indiscutables.In our opinion, Arnaud Mercier describes very acutely the new condition of the professor in the contemporary university. But we may ask the question: what is the meaning of this new condition? Should we talk of a slip-up? Or should we consider the possibility of a complete wipe out of the institution or of the idea of university? As this institution is based on a dialectic between objective forms and subjective freedom it may be considered as a milestone of modernity. This dialectic is precisely what is being threatened now, as the universities are more and more governed by external processes that call for professors to constantly adapt to constraints

Optimisation of selective laser melting parameters for the Ni-based superalloy IN-738 LC using Doehlert’s design

The Ni-based superalloy IN-738 LC is known to be susceptible to porosity and different types of cracking during the build-up process and, thus, challenging to manufacture using selective laser melting (SLM). Determining a feasible set of operating parameters for SLM of nickel-based superalloys involves new approach to experimental design based on the Doehlert method that assists in determining an optimal (feasible) set of operating parameters for SLM of IN-738 LC powder alloy

Threshold resummation for pair production of coloured heavy (s)particles at hadron colliders

We derive a factorization formula for the production of pairs of heavy coloured particles in hadronic collisions near the production threshold that establishes factorization of soft and Coulomb effects. This forms the basis for a combined resummation of Coulomb and soft corrections, including the non-trivial interference of the two effects. We develop a resummation formalism valid at NNLL accuracy using the momentum-space approach to soft gluon resummation. We present numerical results for the NLL resummed squark-antisquark production cross section at the LHC and Tevatron, including also the contribution of squark-antisquark bound states below threshold. The total correction on top of the next-to-leading order approximation is found to be sizeable, and amounts to (4-20)% in the squark mass region 200 GeV-3 TeV at the 14 TeV LHC. The scale dependence of the total cross section is also reduced.Comment: 71 pages, LaTeX, 18 figures. v2 matches published version (minor typos corrected, more references added

Regulation of 3β-Hydroxysteroid Dehydrogenase/∆5-∆4 Isomerase: A Review

This review focuses on the expression and regulation of 3β-hydroxysteroi ddehydrogenase/Δ5-Δ4 isomerase (3β-HSD), with emphasis on the porcine version. 3β-HSD is often associated with steroidogenesis, but its function in the metabolism of both steroids and xenobiotics is more obscure. Based on currently available literature covering humans,rodents and pigs, this review provides an overview of the present knowledge concerning the regulatory mechanisms for 3β-HSD at all omic levels. The HSD isoenzymes are essential in steroid hormone metabolism, both in the synthesis and degradation of steroids. They display tissue-specific expression and factors influencing their activity, which therefore indicates their tissue-specific responses. 3β-HSD is involved in the synthesis of a number of natural steroid hormones, including progesterone and testosterone, and the hepatic degradation of the pheromone androstenone. In general, a number of signaling and regulatory pathways have been demonstrated to influence 3β-HSD transcription and activity, e.g., JAK-STAT, LH/hCG, ERα, AR, SF-1 and PPARα. The expression and enzymic activity of 3β-HSD are also influenced by external factors, such as dietary composition. Much of the research conducted on porcine 3β-HSD is motivated by its importance for the occurrence of the boar taint phenomenon that results from high concentrations of steroids such as androstenone. This topic is also examined in this review

Quantum Gravity in Everyday Life: General Relativity as an Effective Field Theory

This article is meant as a summary and introduction to the ideas of effective field theory as applied to gravitational systems. Contents: 1. Introduction 2. Effective Field Theories 3. Low-Energy Quantum Gravity 4. Explicit Quantum Calculations 5. ConclusionsComment: 56 pages, 2 figures, JHEP style, Invited review to appear in Living Reviews of Relativit

Impact of parental emotional support and coercive control on adolescents' self-esteem and psychological distress : results of a four-year longitudinal study

This study aims at investigating the impact of parental practices on youths’ adjustment. In all, 605 adolescents completed questionnaires at ages 14, 16 and 18. Self-esteem, psychological distress as well as parental emotional support and coercive control were measured. Analyses based on individual growth models revealed that self-esteem increased with age, but psychological distress remained stable over time. Boys reported higher levels of self-esteem and lower levels of psychological distress than girls. Maternal and paternal emotional support reinforced self-esteem over time. Maternal coercive control undermined self-esteem, but only at ages 16 and 18. Psychological distress decreased with parental emotional support but increased with parental coercive control at ages 14, 16 and 18. Overall, these results indicate that positive parental practices are related to youths’ well-being. These findings support the importance of establishing intervention strategies designed to promote best practices among parents of teenagers to help them develop into well-adjusted adults