La réduction des effectifs dans la classe pour favoriser la réussite scolaire: étude de l’implantation et des retombées de la diminution du nombre d’élèves par classe au préscolaire et au premier cycle du primaire au Québec

Au Québec, la mesure de diminution du nombre d’élèves (DNÉ) par classe a été implantée par le ministère de l’Éducation en 2000 au préscolaire et au primaire en milieu défavorisé (Gouvernement du Québec, 1999). Aux États-Unis, la décision du Congrès, en 1999, de financer l’engagement supplémentaire d’enseignants pour favoriser une politique d’égalité des chances par le programme Class Size Reduction (CSR) a rencontré un vif succès puisque, dès 2002, plus de la moitié des états américains avaient ramené à moins de 18 le nombre d’élèves dans les classes des trois premières années de l’école primaire. La rapide adhésion à ce programme s’explique par l’ampleur des budgets dégagés et aussi par un large accord sur l’efficacité de cette mesure quant à l’amélioration de la réussite scolaire. Le Québec, grâce à un octroi de près de 2 000 postes d’enseignants, a aussi instauré, de 2000 à 2004, une mesure de DNÉ dans les classes du premier cycle du primaire (passage d’une moyenne de 23-25 à 20-22) et réduit encore plus les effectifs en milieu socioéconomiquement faible (MSÉF) où, comme dans les maternelles, la première et la deuxième année comptent dorénavant 18 élèves et moins. L’intérêt que suscite cette mesure est dû à l’ensemble des recherches documentaires et évaluatives qui, historiquement, depuis Head Start et Follow Through, à la fin des années 1960, jusqu’au projet de référence Student Teacher Achievement Ratio (STAR) au Tennessee, en 1997-99, en passant par les programmes « A Nation at Risk » et « No Child Left Behind », ont montré, aux États-Unis, en quoi le contrôle de l’effectif d’un groupe-classe au début de la scolarisation permettait à la fois de « créer un environnement favorable aux apprentissages et à la réussite de tous les élèves » tout en permettant de « reconnaître les premières manifestations des difficultés et d’intervenir rapidement » (Gouvernement du Québec, 1999, p. 3). Les États-Unis et le Québec (Chatterji, 2006; Neveu et Blais, 2002) ne sont pas les seuls à s’appuyer sur ces conclusions documentées puisque le Canada (Bascia, 2010a; Bascia 2010b; Haughey et al., 2003; Nicholls, 2002), comme l’ensemble des pays du Commonwealth (Pedder, 2006; ENAP, 2007), mais aussi de l’Union européenne 3 (Parlement de la Communauté Française de Belgique, 2005; OCDE, 2008; Jakubowski et Sakiwiki, 2006), reconnaissent l’impact favorable sur la réussite scolaire de la réduction de la taille des groupes dans les trois premières années de scolarisation, en particulier chez des enfants de groupes vulnérables : afro-américains aux États-Unis, issus de l’immigration récente en Europe, de milieux défavorisés au Québec, etc. Une classe avec moins d’élèves devrait demander moins d’interventions disciplinaires et, du coup, améliorer les interactions (relations élèves–enseignants, relations entre les élèves, travail d’équipe, etc.), favoriser l’individualisation de l’apprentissage (aide spécifique en classe, réponse aux besoins individuels), libérer un plus large espace pour les élèves et augmenter le temps et la qualité de l’enseignement dispensé (approfondissement des savoirs, plus grande discipline). 2. Principales questions Les débats sont encore nombreux et les recherches au Québec doivent à leur tour tenter d’évaluer pourquoi et dans quelles conditions la DNÉ produit un changement positif, notamment chez les élèves à risque. Afin d’y répondre, il faut poser une série de questions qui dépassent le simple constat d’un lien diminution-amélioration en identifiant les effets : 1. Sur quoi : l’apprentissage, les performances scolaires, l’intégration socioscolaire? 2. Sur qui : les titulaires des classes du premier cycle du primaire, les autres enseignants, les élèves, les spécialistes, les parents? 3. Comment : quels facteurs sont en jeu, quelles variables interviennent ? La qualité des enseignants? Les besoins des élèves? Le climat de classe? Le projet pédagogique? 4. À travers quelles médiations : les relations et interactions enseignant-élève(s), les approches pédagogiques, l’individuation des apprentissages, le travail d’équipe? 5. Avec quelles ressources : structurelles, organisationnelles, budgétaires, humaines? 6. Dans quelles conditions : de financement, d’implantation, de développement, de maintien, d’évaluation? 7. Jusqu’à quel point : avec quels résultats quant à l’objectif premier de créer un environnement favorable à l’apprentissage et propice à identifier les difficultés dès leur apparition afin d’améliorer la réussite? 4 3. Objectifs poursuivis Pour répondre à ces questions, une équipe multidisciplinaire (psychologie, sociologie, éducation) et interuniversitaire (UQAM, UdeM et USHERB), composée de chercheurs et de leurs assistants étudiants qui partagent des thèmes communs liés à l’égalité des chances en éducation (Terrisse et al., 2001; Larivée et al., 2006), veut, dix ans après l’instauration de la DNÉ au Québec et au moment du passage récent au secondaire des premiers élèves bénéficiaires de cette mesure, conduire une recherche évaluative issue d’une proposition commune du FQRSC, du MÉLS et de la FCSQ. Cet appel oriente la définition des objectifs de cette recherche, soit : 1. Identifier les conditions d’implantation de la mesure de DNÉ (besoin 1) 2. Analyser les retombées pédagogiques directes sur les classes de petite taille (besoin 2) et indirectes sur l’école et le milieu (besoins 2 et 3) 3. Comparer les résultats de ces analyses aux expériences similaires nationales et internationales.Ministère de l’Éducation, du Loisir et du Sport (MELS) Fonds québécois de recherche sur la société et la culture (FQRSC) Fédération des commissions scolaires du Québec (FCSQ

Is virtual reality effective to teach prevention of surgical site infections in the operating room? study protocol for a randomised controlled multicentre trial entitled VIP Room study

INTRODUCTION: Some surgical site infections (SSI) could be prevented by following adequate infection prevention and control (IPC) measures. Poor compliance with IPC measures often occurs due to knowledge gaps and insufficient education of healthcare professionals. The education and training of SSI preventive measures does not usually take place in the operating room (OR), due to safety, and organisational and logistic issues. The proposed study aims to compare virtual reality (VR) as a tool for medical students to learn the SSI prevention measures and adequate behaviours (eg, limit movements…) in the OR, to conventional teaching. METHODS AND ANALYSIS: This protocol describes a randomised controlled multicentre trial comparing an educational intervention based on VR simulation to routine education. This multicentre study will be performed in three universities: Grenoble Alpes University (France), Imperial College London (UK) and University of Heidelberg (Germany). Third-year medical students of each university will be randomised in two groups. The students randomised in the intervention group will follow VR teaching. The students randomised in the control group will follow a conventional education programme. Primary outcome will be the difference between scores obtained at the IPC exam at the end of the year between the two groups. The written exam will be the same in the three countries. Secondary outcomes will be satisfaction and students' progression for the VR group. The data will be analysed with intention-to-treat and per protocol. ETHICS AND DISSEMINATION: This study has been approved by the Medical Education Ethics Committee of the London Imperial College (MEEC1920-172), by the Ethical Committee for the Research of Grenoble Alpes University (CER Grenoble Alpes-Avis-2019-099-24-2) and by the Ethics Committee of the Medical Faculty of Heidelberg University (S-765/2019). Results will be published in peer-reviewed medical journals, communicated to participants, general public and all relevant stakeholders

Engineered Electronic Contacts for Composite Electrodes in Li Batteries Using Thiophene-based Molecular Junctions

Fourier transform infrared spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy experiments indicate that molecular junctions can be achieved between non-carbon-coated LiFePO4 (LFP) and multiwall carbon nanotubes (MWCNT) using a thiophene-based conjugated system which was designed to selectively functionalize these two different types of surfaces. The strategy enables the architecturing of the cathode electrode of lithium batteries, leading to a vast improvement in the component intermixing, which results in the individual MWCNT being nanocontacted at the surface of LFP grains. This advancement leads to much higher specific capacity, especially at high charge/discharge rates, for undensified electrodes of 2 mA h cm–2, for which the electronic wiring of the electroactive material is a critical issue. Furthermore, thanks to molecular junctions, better capacity retention comparable to that of carbon-coated LiFePO4 electrodes could be achieved. These results are expected to trigger the development of novel electron transport engineering methods, of special interest for industry-relevant thick battery electrodes

Apolipoprotein D synthesis progressively increases in frontal cortex during human lifespan

Apolipoprotein D (apo D) is a lipocalin present in the nervous system that may be related to processes of reinnervation, regeneration and neuronal cell protection. In the other way, apo D expression has been correlated, in some brain regions, with normal aging and neurodegenerative diseases. To elucidate the regional and cellular expression of apo D in normal human brain during aging, we performed a detailed and extensive study in samples of post-mortem human cerebral cortices. To achieve this study, slot blot techniques, for protein and mRNA, as well as immunohistochemistry and hybridohistochemistry methods were used. A positive correlation for apo D expression with aging was found; furthermore, mRNA levels, as well as the protein ones, were higher in the white than in the grey matter. Immunohistochemistry and non-isotopic HIS showed that apo D is synthesized in both neurons and glial cells. Apo D expression is notorious in oligodendrocytes but with aging the number of neurons that synthesize apo D is increased. Our results indicate that apo D could play a fundamental role in central nervous system aging and in the reduction of products derivated from lipid peroxidation. The increment in the expression of apo D with aging can be included in a global mechanism of cellular protection to prevent the deleterious effects caused by aging

Molecular Dynamics Analysis of Apolipoprotein-D - Lipid Hydroperoxide Interactions: Mechanism for Selective Oxidation of Met-93

Background: Recent studies suggest reduction of radical-propagating fatty acid hydroperoxides to inert hydroxides by interaction with apolipoprotein-D (apoD) Met93 may represent an antioxidant function for apoD. The nature and structural consequences of this selective interaction are unknown. Methodology/Principal Findings: Herein we used molecular dynamics (MD) analysis to address these issues. Longtimescale simulations of apoD suggest lipid molecules are bound flexibly, with the molecules free to explore multiple conformations in a binding site at the entrance to the classical lipocalin ligand-binding pocket. Models of 5s- 12s- and 15s hydroperoxyeicosatetraenoic acids were created and the lipids found to wrap around Met93 thus providing a plausible mechanism by which eicosatetraenoic acids bearing hydroperoxides on different carbon atoms can interact with Met93 to yield Met93 sulfoxide (Met93SO). Simulations of glycosylated apoD indicated that a second solvent exposed Met at position 49 was shielded by a triantennerary N-glycan attached to Asn45 thereby precluding lipid interactions. MD simulations of apoD showed B-factors of the loop containing Met93SO were higher in the oxidized protein, indicating increased flexibility that is predicted to destabilize the protein and promote self-association. Conclusions/Significance: These studies provide novel insights into the mechanisms that may contribute to the antioxidant function of apoD and the structural consequences that result if Met93SO is not redox-cycled back to its native state

Identification of New SRF Binding Sites in Genes Modulated by SRF Over-Expression in Mouse Hearts

Background To identify in vivo new cardiac binding sites of serum response factor (SRF) in genes and to study the response of these genes to mild over-expression of SRF, we employed a cardiac-specific, transgenic mouse model, with mild over-expression of SRF (Mild-O SRF Tg). Methodology Microarray experiments were performed on hearts of Mild-O-SRF Tg at 6 months of age. We identified 207 genes that are important for cardiac function that were differentially expressed in vivo. Among them the promoter region of 192 genes had SRF binding motifs, the classic CArG or CArG-like (CArG-L) elements. Fifty-one of the 56 genes with classic SRF binding sites had not been previously reported. These SRF-modulated genes were grouped into 12 categories based on their function. It was observed that genes associated with cardiac energy metabolism shifted toward that of carbohydrate metabolism and away from that of fatty acid metabolism. The expression of genes that are involved in transcription and ion regulation were decreased, but expression of cytoskeletal genes was significantly increased. Using public databases of mouse models of hemodynamic stress (GEO database), we also found that similar altered expression of the SRF-modulated genes occurred in these hearts with cardiac ischemia or aortic constriction as well. Conclusion and significance SRF-modulated genes are actively regulated under various physiological and pathological conditions. We have discovered that a large number of cardiac genes have classic SRF binding sites and were significantly modulated in the Mild-O-SRF Tg mouse hearts. Hence, the mild elevation of SRF protein in the heart that is observed during typical adult aging may have a major impact on many SRF-modulated genes, thereby affecting Cardiac structure and performance. The results from our study could help to enhance our understanding of SRF regulation of cellular processes in the aged heart

Heat Shock Proteins and Amateur Chaperones in Amyloid-Beta Accumulation and Clearance in Alzheimer’s Disease

The pathologic lesions of Alzheimer’s disease (AD) are characterized by accumulation of protein aggregates consisting of intracellular or extracellular misfolded proteins. The amyloid-β (Aβ) protein accumulates extracellularly in senile plaques and cerebral amyloid angiopathy, whereas the hyperphosphorylated tau protein accumulates intracellularly as neurofibrillary tangles. “Professional chaperones”, such as the heat shock protein family, have a function in the prevention of protein misfolding and subsequent aggregation. “Amateur” chaperones, such as apolipoproteins and heparan sulfate proteoglycans, bind amyloidogenic proteins and may affect their aggregation process. Professional and amateur chaperones not only colocalize with the pathological lesions of AD, but may also be involved in conformational changes of Aβ, and in the clearance of Aβ from the brain via phagocytosis or active transport across the blood–brain barrier. Thus, both professional and amateur chaperones may be involved in the aggregation, accumulation, persistence, and clearance of Aβ and tau and in other Aβ-associated reactions such as inflammation associated with AD lesions, and may, therefore, serve as potential targets for therapeutic intervention