Aider l'élève à comprendre le fonctionnement de la physique et son articulation avec la vie quotidienne

National audienceCet article est une réflexion issue du travail d'un groupe de recherche-développement de l'académie de Lyon (groupe « Outils »), soutenu et financé par l'INRP (Institut national de recherche pédagogique) et ayant réuni pendant trois ans, de 1998 à 2001 (1), des chercheurs en didactique et des enseignants [1]. Il approfondit les sujets abordés dans un article précédent au sujet de l'activité de modélisation en physique, en proposant des outils plus opératoires pour enseigner afin d'aider l'élève à distinguer le monde matériel d'une part, les théories et modèles qui permettent de le décrire ou de l'interpréter d'autre part. En partant du constat que les élèves en situation d'apprendre de la physique doivent confronter des connaissances issues de la vie quotidienne et des connaissances de la physique, nous proposons à l'enseignant deux outils principaux :♦ marquer la distinction entre objets-événements et modèles, en explicitant d'une part les choix et démarches des physiciens, d'autre part les choix de l'enseignant lorsqu'il soumet à l'étude une situation matérielle ;♦ exercer sa vigilance quant aux termes qu'il utilise, en particulier lorsque le sens dans la vie quotidienne diffère largement du sens en physique.Si ces outils peuvent être utilisés pour n'importe quel type d'enseignement de physique, nous listons cependant quelques caractéristiques d'une gestion de classe qui nous paraît favoriser leur mise en place et leur efficacité pour l'apprentissage des élève

Design-based research: case of a teaching sequence on mechanics

Design-based research, and particularly its theoretical status, is a subject of debate in the science education community. In the first part of this paper, a theoretical framework drawn up to develop design-based research will be presented. This framework is mainly based on epistemological analysis of physics modelling, learning and teaching hypotheses. It includes grand theories, a specific theory that following Cobb & al. (2003) is a ‘humble theory’ in the sense that it does ‘real work’, and tools for design. In the second part, we will show how this specific theory and its tools led designers to develop teaching resources in the case of a teaching sequence on mechanics (grade 10). We will explain how the components of the specific theory and tools guide the design at different levels; the conceptual structure of the teaching sequence, the chronology of the activities, the various choices of the type of activity and their wording. This presentation makes the bases of designing teaching resources explicit and therefore allows for scientific debate

Profils d'attitudes à l'égard des sciences chez des élèves en fin de collège et début de lycée : influence sur les formes de motivation en classe et perspectives pour les pratiques pédagogiques.

National audienceUsing a closed questionnaire about science we have obtained data on a population of 552 French students from grade 9, 10 and 11. The questions evoked attitudes toward either the sciences in the society, or the taught scientific contents, or the teaching modalities in sciences and in the scholar organisation. Statistical analysis shows that 6 typical classes of students can be defined. Our results can be summarized as follow : a) the two major classes are characterized by students with positive attitudes toward scholar work but one profile ends up with the lowest motivation in science classes being highly frustrated by teaching modalities and the other with a motivation driven by utilitarian goals. The others profiles correspond to students having rather good auto-determination and motivation apart for one expressing negativity and a need for loneliness.Des élèves français de 3ème, 2nde et 1ère (N=552) ont répondu à un questionnaire écrit fermé interrogeant leurs attitudes à l'égard des sciences. Nous avons cherché à déterminer s'il existait des profils d'attitudes typiques au sein de cette population d'élèves dans le but de comprendre comment les individus de cette génération perçoivent les sciences et leur rôle social, les sciences enseignées et leur rôle dans l'organisation scolaire, ainsi que leur propre futur dans ce contexte. Nous avons trouvé 6 profils statistiquement significatifs L'analyse des attitudes caractérisant chaque profil permet de déduire la modalité la plus probable de régulation de la motivation de chacun d'eux et permet de dresser un bilan des points qui pourraient être modifiés par des actions pédagogiques, et pourraient constituer une potentielle remédiation aux frustrations des élèves

The Interleukin-6 Gene Promoter Polymorphism -174 and Atherosclerotic Events in Overweight Transplanted Patients

Chronic inflammation plays a pivotal role in atherosclerosis. We hypothesized that combining overweight and a greater genetic capacity to produce IL-6 predicted by IL-6 gene promoter polymorphism at position -174 (G→C) may allow to identify individuals exhibiting higher IL-6 and C-reactive protein (CRP) concentrations with a higher risk of atherosclerotic events (AE). The occurrence of AE was analyzed with respect to body mass index, IL-6 gene promoter polymorphism at position -174 (G→C), and other relevant risk factors, retrospectively, in 217 renal transplant recipients and, prospectively, in 132. Circulating IL-6 concentrations were closely related to BMI (r = 0.55, P = .0005). In overweight patients, serum IL-6 concentration was found to be significantly lower in C carriers than in GG patients (4.2 [1.0–5.1] versus 7.3 pg/mL [4.4–100]; P = .025). The incidence of AE was higher in overweight GG patients (29.5% versus 10.1%; P = .0003). In multivariate analysis, overweight-GG had an increased risk to develop AE (HR 2.96 [95% CI 1.09–8.04], P = .034 in the retrospective cohort, and HR 2.99 [95% CI 0.92–9.33], P = .069 in the prospective cohort). All these data are consistent with a role for both genetic and environmental determinants of inflammation (white adipose tissue mass) in the development of AE in renal transplanted patients

Increased production of soluble CTLA-4 in patients with spondylarthropathies correlates with disease activity

International audienceINTRODUCTION: Spondylarthropathies (SpA) are characterized by abnormal immune responses including T cell activation. Cytotoxic T lymphocyte associated molecule-4 (CTLA-4) is involved in down-regulating immune responses. A soluble form of CTLA-4 (sCTLA-4), resulting from an alternative splicing, has been identified and was found increased in several autoimmune diseases. Here, we evaluated circulating levels of sCTLA-4 as a marker of immune dysregulation in SpA. Intracellular CTLA-4 and levels of CTLA-4 transcript expression in peripheral blood lymphocytes (PBL) were also studied. METHODS: Sera from 165 patients with SpA were evaluated for sCTLA-4 measurements. Results were compared with those from 71 patients with rheumatoid arthritis (RA) and 88 healthy subjects. In 32 patients with SpA, 22 patients with RA and 15 healthy controls, we analyzed the intracellular CTLA-4 expression in CD4+ T cells, CD8+ T cells, activated (HLA-DR+Foxp3-) CD4+ T cells, CD4+ regulatory (CD25+Foxp3+) T cells and in CD3 negative cells by flow cytometry. Expression of the full length (coding for membrane CTLA-4) and spliced form (coding for sCTLA-4) of CTLA-4 transcripts in PBL were analyzed by quantitative real-time polymerase chain reaction (QRT-PCR). RESULTS: High levels of sCTLA-4 were found in the SpA group compared to the RA group and healthy controls (P < 0.0001). Soluble CTLA-4 serum levels strongly correlated with clinical index of disease activity BASDAI (r = 0.42, P < 0.0001) and C-reactive protein (CRP) levels (r = 0.17, P = 0.037). In contrast to RA patients, SpA patients did not exhibit changes in intracellular CTLA-4 expression in the different PBL subsets tested. Finally, the SpA group showed a preferential expression of the spliced CTLA-4 mRNA (P = 0.0014) in PBL. CONCLUSIONS: SpA patients exhibit high levels of circulating sCTLA-4 that may result from an alternative splicing of CTLA-4 transcripts. This may influence immune activation and regulation in SpA

No evidence of association between NOD2/CARD15 gene polymorphism and atherosclerotic events after renal transplantation.

International audienceStable renal transplant recipients (RTR) display high rates of atherosclerotic events (AE). Innate immunity and especially vascular inflammation play a role in the pathogenesis of atherosclerosis. It is illustrated both by an increased occurrence of postrenal transplant cardiovascular events in patients with elevated levels of C-reactive protein and by a correlation between posttransplant AE and Toll-like receptor-4 Asp299Gly polymorphism. Here, we analyze the influence NOD2/CARD15 gene polymorphism since NOD2 can modulate macrophage pro-inflammatory activity and macrophage is present in early atherosclerotic lesions. The incidence of single nucleotide polymorphism (SNP) in the three major polymorphic region of NOD2 gene (SNP8, SNP12 and SNP13) was assessed in 182 RTR and the correlation between such polymorphism and the development of AE was analyzed. No correlation was observed between NOD2 gene polymorphism and the occurrence of AE after renal transplantation. NOD2 gene polymorphism thus does not appear to influence cardiovascular complications in RTR

A global analysis of the use of immunoglobulin, shortages in supply, and mitigating measures:A survey of hospital providers (a BEST Collaborative study)

Background:Immunoglobulin (IG) therapy is widely used to treat primary and secondary immune deficiencies and as immunomodulatory agent for various disorders. There is great concern that shortages of IG may rise, potentially affecting medical treatment options. Study Design and Methods: An international survey was developed to study how intravenous immunoglobulins (IVIGs) are used and managed within hospitals in case of shortages. Study data were collected and managed using REDCap electronic data capture tools hosted by the Biomedical Excellence for Safer Transfusion (BEST) Collaborative. The survey was directed to hospital pharmacists and blood bank transfusion professionals and disseminated through members of the BEST Collaborative network. Results: Survey respondents from institutions in the USA, Canada, Europe, Japan, and Australia (n = 13) confirmed that the primary specialties utilizing IG are neurology, hematology, and immunology. More than 60% of respondents reported IG supply shortages, but mitigation strategies were not well developed. Discussion: As IG is the leading driver in plasma demand, more studies are needed to understand current and future demand for IG from the clinical perspective. Necessity lies in establishing clinical guidance to address shortages.</p

A global analysis of the use of immunoglobulin, shortages in supply, and mitigating measures:A survey of hospital providers (a BEST Collaborative study)

Background:Immunoglobulin (IG) therapy is widely used to treat primary and secondary immune deficiencies and as immunomodulatory agent for various disorders. There is great concern that shortages of IG may rise, potentially affecting medical treatment options. Study Design and Methods: An international survey was developed to study how intravenous immunoglobulins (IVIGs) are used and managed within hospitals in case of shortages. Study data were collected and managed using REDCap electronic data capture tools hosted by the Biomedical Excellence for Safer Transfusion (BEST) Collaborative. The survey was directed to hospital pharmacists and blood bank transfusion professionals and disseminated through members of the BEST Collaborative network. Results: Survey respondents from institutions in the USA, Canada, Europe, Japan, and Australia (n = 13) confirmed that the primary specialties utilizing IG are neurology, hematology, and immunology. More than 60% of respondents reported IG supply shortages, but mitigation strategies were not well developed. Discussion: As IG is the leading driver in plasma demand, more studies are needed to understand current and future demand for IG from the clinical perspective. Necessity lies in establishing clinical guidance to address shortages.</p

The role of convalescent plasma and hyperimmune immunoglobulins in the COVID-19 pandemic, including implications for future preparedness

Introduction: When Coronavirus Disease-19 (COVID-19) struck the world in December 2019, initiatives started to investigate the efficacy of convalescent plasma, a readily available source of passive antibodies, collected from recovered patients as a therapeutic option. This was based on historical observational data from previous virus outbreaks. Methods: A scoping review was conducted on the efficacy and safety of convalescent plasma and hyperimmune immunoglobulins for COVID-19 treatment. This review included the latest Cochrane systematic review update on 30-day mortality and safety. We also covered use in pediatric and immunocompromised patients, as well as the logistic challenges faced in donor recruitment and plasma collection in general. Challenges for low resource countries were specifically highlighted. Results: A major challenge is the high donation frequency required from first-time donors to ensure a safe product, which minimizes the risk of transfusion-transmitted infectious. This is particularly difficult in low- and middle- income countries due to inadequate infrastructure and insufficient blood product supplies. High-certainty evidence indicates that convalescent plasma does not reduce mortality or significantly improve clinical outcomes in patients with moderate to severe COVID-19 infection. However, CCP may provide a viable treatment for patients unable to mount an endogenous immune response to SARS-CoV-2, based on mostly observational studies and subgroup data of published and ongoing randomized trials. Convalescent plasma has been shown to be safe in adults and children with COVID-19 infection. However, the efficacy in pediatric patients remains unclear. Discussion: Data on efficacy and safety of CCP are still underway in ongoing (randomized) studies and by reporting the challenges, limitations and successes encountered to-date, research gaps were identified to be addressed for the future. Conclusion: This experience serves as a valuable example for future pandemic preparedness, particularly when therapeutic options are limited, and vaccines are either being developed or ineffective due to underlying immunosuppression

Partager un corpus vidéo dans la recherche en éducation : analyses et regards pluriels dans le cadre du projet ViSA

Introduction du numéro Ce numéro spécial présente un travail coordonné de chercheurs en éducation scolaire qui étudient les pratiques d’enseignement-apprentissage en classe. Il a été mené dans le cadre de la structure fédérative de recherche ViSA (Video de Situations d’enseignement et d’Apprentissage). Cette structure qui réunit onze unités de recherche vise à : développer une réflexion épistémologique sur la nature des données vidéo ; systématiser les pratiques de constitution et d’utilisati..