La théorie des systèmes développementaux et la construction sociale des maladies mentales

Dans ce texte, nous proposons un cadre, qui vise à intégrer les contributions des approches constructionnistes et biologiques dans un domaine précis, celui des maladies mentales. Pour ce faire, nous utiliserons quelques propositions récentes faites par des philosophes de la biologie — plus spécifiquement les idées avancées par les tenants de la « théorie des systèmes développementaux » (TSD dans ce qui suit ; Griffiths et Gray, 1994 ; Griffiths et Stoltz, 2000 ; Oyama, 1999) ainsi que la notion d’« enracinement génératif » (generative entrenchment ; Wimsatt, 1986, 1999, 2000).In this paper, we are proposing a framework to integrate the core insights of the constructivist and biological approaches of mental illness. In order to do so, we will use some recent propositions by philosophers of biology, specifically ideas put forth by «developmental system theory» (Griffiths et Gray 1994, Griffiths et Stotz 2000 ; Oyama 1999) and the notion of «generative entrenchment» (Wimsatt 1986, 1999, 2000)

Étude comparative des facteurs influençant les élèves du secondaire privé à choisir un collège privé ou public pour la suite de leurs études

Rapport final d'un projet de recherche financé par l'Association des collèges privés du Québec (ACPQ) dans le cadre du programme de recherche et d’expérimentation pédagogique (PREP) et appuyé par la Fédération des établissements d'enseignement privé (FEEP).Comprend des références bibliographiques

Les facteurs influençant le choix de fréquenter un collège privé ou public [rapport final]

Rapport final d'un projet de recherche financé par l'Association des collèges privés du Québec (ACPQ) dans le cadre du programme de recherche et d’expérimentation pédagogique (PREP) et appuyé par la Fédération des établissements d'enseignement privé (FEEP)

Effect of evaporator length on the performance of a self-oscillating fluidic heat engine (SOFHE)

Abstract: This paper reports the effect of evaporator length on the performance of a self-oscillating fluidic heat engine (SOFHE). The SOFHE is a thermal energy harvester, when coupled with an electro-mechanical transducer that was proposed to power wireless sensors widely used in the Internet of Things (IoT). The mechanical power of the SOFHE is in the order of fraction of milliwatts, which makes it a promising power supply for a range of wireless sensors with the power requirements of 10s µW. The SOFHE consists of a vapor bubble trapped by an oscillating liquid plug acting as a piston. The working principle of the SOFHE is similar to a singlebranch pulsating heat pipe. The engine is a small tube (inner diameter of 2 mm) filled with deionized water heated from a closed end and cooled from the opposite open end. By perturbing the equilibrium of the vapor bubble-liquid plug, oscillation start and are sustained by cyclic evaporationcondensation from a thin film in the vapor bubble. To characterize SOFHE’s mechanical power as a function of the evaporator length, measurements of pressure, oscillation amplitude, and frequency are conducted. As the evaporator length decreases (from 7 cm to 1 cm), the oscillation amplitude decreases (from 5.9 mm to 1.5 mm) while the frequency increases (from 27 Hz to 52 Hz). In theory, the power of SOFHE is proportional to the square of frequency and amplitude, so the trend in power is not obvious given the opposing effects. The results show a decrease in the mechanical power from 380 µW to 180 µW, which implies that the negative effect of the amplitude decrease dominates over the increase in frequency. A fourfold decrease was also observed in the net evaporation rate (from 1027 to 242 µg/s), which explains why the amplitude decreases with the evaporator length. The research findings contribute to the design of both SOFHEs and pulsating heat pipes by suggesting that a longer heated zone improves the performance.Communication présentée lors du congrès international tenu conjointement par Canadian Society for Mechanical Engineering (CSME) et Computational Fluid Dynamics Society of Canada (CFD Canada), à l’Université de Sherbrooke (Québec), du 28 au 31 mai 2023

Maternally encoded stem-loop-binding protein is degraded in 2-cell mouse embryos by the co-ordinated activity of two separately regulated pathways

AbstractOocytes accumulate mRNAs and proteins that direct early embryonic development. Although subsequent development requires the timely degradation of these maternal products, little is known of the underlying mechanisms. The stem-loop-binding protein (SLBP), which regulates the stability and translation of mRNAs encoding histones and is synthesized during S-phase and degraded during G2 in somatic cells, accumulates during oogenesis. Maternal SLBP is required for mouse embryos to develop beyond the 2-cell stage, but must be degraded to allow the cell-cycle-regulated expression of somatic cells to be established. We report that the quantity of maternal SLBP changes little following fertilization until 44–52 h post-hCG, corresponding to mid-/late G2 of the 2-cell stage, when it decreases by 75%. Efficient degradation requires two pathways. The first requires activity of cyclin-dependent kinases (cdk) and embryonic transcription, preferentially targets nuclear SLBP, and likely corresponds to the pathway that degrades SLBP at G2 in somatic cells. The second does not require cdk activity or transcription and becomes active at 44–52 h post-hCG independently of cell-cycle progression to mid-/late G2, but is not solely regulated by the time elapsed since hCG injection. Thus, the co-ordinated activity of two separately regulated pathways eliminates maternally encoded SLBP from early mouse embryos

High-Resolution 1.5-Tesla Magnetic Resonance Imaging for Tissue-Engineered Constructs: A Noninvasive Tool to Assess Three-Dimensional Scaffold Architecture and Cell Seeding

International audienceTissue-engineered scaffolds are made of biocompatible polymers with various structures, allowing cell seeding, growth, and differentiation. Noninvasive imaging methods are needed to study tissue-engineered constructs before and after implantation. Here, we show that high-resolution magnetic resonance imaging (MRI) performed on a clinical 1.5-T device is a reliable technique to assess three-dimensional structures of porous scaffolds and to validate cell-seeding procedures. A high-temperature superconducting detection coil was used to achieve a resolution of 30Â30Â30 mm 3 when imaging the scaffolds. Three types of structures with tuneable architectures were prepared from naturally derived polysaccharides and evaluated as scaffolds for mesenchymal stem cell (MSC) culture. To monitor cell seeding, MSCs were magnetically labeled using simple incubation with anionic citrate-coated iron-oxide nanoparticles for 30 min. Iron uptake was quantified using single-cell magnetophoresis, and cell proliferation was checked for 7 days after labeling. Three-dimensional (3D) microstructures of scaffolds were assessed using MRI, revealing lamellar or globular porous organization according to the scaffold preparation process. MSCs with different iron load (5, 12 and 31 pg of iron per cell) were seeded on scaffolds at low density (132 cells=mm 3) and detected on 3D gradient-echo MR images according to phase distortions and areas of intensely low signal, whose size increased with cell iron load and echo time. Overall signal loss in the scaffold correlated with the number of seeded cells and their iron load. Different organizations of cells were observed depending on the scaffold architecture. After subcutaneous implantation in mice, scaffolds seeded with labeled cells could be distinguished in vivo from scaffold with nonlabeled cells by observation of signal and phase heterogeneities and by measuring the global signal loss. High-resolution 1.5-T MRI combined with efficient intracellular contrast agents shows promise for noninvasive 3D visualization of tissue-engineered constructs before and after in vivo implantation

Physically-based preconditioner for the WCIP

International audienceA physically-based preconditioner for the 1d and 2d Wave Concept Iterative Procedure is introduced in this paper. Numerical results are provided to assess the efficiency of this technique

Molecular Magnetic Resonance and Ultrasound Imaging of Tumor Angiogenesis

International audienc

The ESO Distant Cluster Sample: galaxy evolution and environment out to z=1

The ESO Distant Cluster Survey (EDisCS, P.I. Simon D.M. White, LP 166.A-0162) is an ESO large programme aimed at studying clusters and cluster galaxies at z=0.4-1. How different is the evolution of the star formation activity in clusters, in groups and in the field? Does it depend on cluster mass and/or the local galaxy density? How relevant are starburst and post-starburst galaxies in the different environments? Is there an evolution in the galaxies' structures, and if so, is this related to the changes in their star formation activity? These are some of the main questions that have been investigated using the EDisCS dataset.Comment: to appear in The Messenger, issue June 200