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Ma pratique est meilleure que la vôtre ?!: La sociologie à l’épreuve des valeurs personnelles dans les SC-AM
No full textInternational audienceLes sports de combat et les arts martiaux cristallisent des tensionssur des pratiques très diverses, potentiellement destructrices et autodestructrices.Cette possibilité amène à questionner l’altérité, notamment parce qu’ellene peut être expérimentée sans l’autre, impliquant une nécessaire « coexistence »(Merleau-Ponty, 1945) au sein de ses activités physiques, sans toutefois se limiterà ce même rapport à autrui (Ricoeur, 1990). L’autre ne peut pas être séparé de monvécu expérientiel et de mon intentionnalité, ne serait-ce que dans sa virtualité.Peu importe la place et l’importance qu’il occupe dans nos représentations (Jodelet,1994) et nos perceptions, il est avant tout un autre moi-même. Cela impliqueégalement une part d’inconnu, dont notre propre rapport au corps, entraînant unenécessaire rencontre ou reconnaissance de l’autre et de soi.L’« autre » est-il alors perçu comme un adversaire ou un partenaire ?L’altérité s’illustre ici différemment selon les normes et les règles, lesquelles varientaussi d’une pratique à l’autre. Du judo jusqu’au Mixed Martial Arts, en passantpar le karaté, la lutte, la boxe, le jiu-jitsu, la self-défense, etc., la grande diversitédes SC-AM offre des configurations différentes: percussion, préhension, attaque/défense, mixité, ainsi que toutes leurs déclinaisons symboliques. Tout en étantconscient de ce relativisme, nous sommes tous et toutes travaillés par des jugementsde valeurs qui forcent une classification de pratiques plus ou moins légitimes.Ces dernières peuvent alors être prises dans une logique distinctive selonle lignage de la formation par exemple, ou au contraire véhiculer de vives critiquesles associant parfois à du “mytho-jitsu”. Le débat est désormais intégré dans uneculture numérique où le nombre de followers d’un instructeur sur les réseaux sociauxparticipe grandement à la notoriété, voire la légitimité d’une discipline.De l’expérience à la connaissance, c’est avec cette posture d’athlète offertepar l’altérité, faisant face à l’inconnu et à la diversité, que nous proposonsune communication à trois voix, laissant les questions introduire les propos. Considérantqu’une pratique de combat ne fait pas consensus et qu’elle peut menerjusqu’aux avis socio-centriques, la salle deviendra alors, avec les professionnels,chercheurs et pratiquants qui la composent, un terrain ou une surface de lutteentre réflexions pluridisciplinaires, représentations et sociologie des parcours devie. Cela nécessite également une modération des questions introductives, telun arbitre officiant dans une compétition. Idéalement, nous souhaiterions que leséchanges débouchent sur un rapport plus scientifique aux altérités que nous nousreprésentons tous et toutes, voire favoriser le développement d’une littératie despratiques martiales dans l’esprit d’un travail herméneutique de groupe
L’environnement de travail et ses impacts sur la santé : enjeux et perspectives pour 2040
No full textNational audienceThe work environment is a singular environment that plays a fundamental role in the physical and mental health of all workers. While it has many similarities with the general environment, it also has its own particularities in terms of regulations, risks, exposomes, time and inequalities, the perspectives of which need to be developed in cooperation between decision-makers, occupational health professionals (doctors, nurses and teams), prevention specialists and workers, in the interests of decent work.L’environnement de travail est un environnement singulier qui joue un rôle fondamental dans la santé physique et mentale des « travaillants » – personne effectuant un travail quelle que soit leur condition sociale. Certes, il présente des similitudes avec l’environnement général, mais il présente des particularités entre réglementations, risques, exposomes, temps et inégalités dont les perspectives sont à construire en coopération entre décideurs, professionnels de santé au travail (médecins-infirmier et équipe), les acteurs de la prévention et les travaillants, pour un travail décent
Efficacy of nutritional plant-based extracts from Aframomum citratum and Xylopia parviflora in mitigating epididymal and excrement fat accumulation in DIO-C57BL/6 mice
No full textInternational audienceObesity is a major global health issue, frequently exacerbated by high-fat diets (HFDs), which contribute to adverse metabolic outcomes. This study investigates the efficacy of extracts from nutritional plants Aframomum citratum (C.Pereira) K.Schum and Xylopia parviflora Spruce in modulating selected anthropometric parameters and fat deposition in DIO-C57BL/6 mice. Over 30 days, we observed that the extracts significantly attenuated body mass index (BMI) and apparent fat mass index (aFMI) in treated mice compared to HFD controls. Notably, X. parviflora at 200 mg.kg(-1) BW (body weight) effectively reduced both visceral and subcutaneous adipose tissues, while orlistat served as a comparative benchmark. Lipid profile assessments revealed significant decreases in triglycerides, total cholesterol, and fatty acid contents in the epididymal fat pads of treated animals. Gas chromatography-mass spectrometry (GC-MS) analysis confirmed these findings and also indicated that treatment with the extracts enhanced the excretion of fatty acids, suggesting a potential mechanism of lipid malabsorption. Furthermore, histological analyses revealed a marked decrease in adipocyte size in treated groups, indicating a considerable decline in fat deposition. These findings suggest that bioactive compounds, particularly phenolic acids and flavonoids, found in A. citratum and X. parviflora extracts exhibit significant antiobesity properties, positioning them as promising natural therapeutic agents for managing diet-induced obesity. Future research should focus on elucidating the mechanisms responsible for these effects and assessing their clinical applicability. This study contributes valuable insights into the role of dietary interventions in obesity management, with implications for the development of novel therapeutic strategies
RILEM TC 275-HDB: presentation of TC 275-HDB and mechanical performances of the hemp concrete specimens of the interlaboratory comparison
No full textInternational audienceThis study delves into the mechanical performance of hemp concrete-a sustainable construction material-with a focus on how the orientation of the hemp shiv affects its mechanical properties. Employing uniaxial compression testing and advanced Digital Image Correlation (DIC) techniques for surface deformation analysis, the research examines specimens in which the shiv particles are aligned perpendicular and parallel to the load direction. Results indicate significant variability in mechanical behavior-perpendicular specimens demonstrate a clear stiffening phase up to 3% strain before deterioration, whereas parallel specimens lack distinct phases. Moreover, DIC measurements suggest hemp concrete has higher Young's moduli and Poisson's ratios compared to traditional materials, and they underline considerable strain localization, especially at aggregate boundaries in parallel specimens. The DIC analysis provides a deeper understanding of the heterogeneous strain distribution, highlighting the interfacial transition zone's influence on the material's mechanical characteristics. These insights are pivotal for optimizing the use of hemp concrete in sustainable building design
Relaxation Parameter Optimization in Electrical-to-Mechanical Co-Simulation Based on Time Windowing WR Technique
No full textInternational audienceThis paper presents an innovative approach to enhancing the time windowing waveform relaxation (WR) technique in electrical-to-mechanical co-simulation by optimizing relaxation parameters for improved performance. An analytical model is introduced to determine the optimal number of time windows, considering the circuit's dynamic characteristics. Additionally, a genetic algorithm (GA) is applied to refine relaxation parameters (e.g., impedance values), effectively addressing challenges posed by nonlinear device behaviors and improving the accuracy of co-simulation results. In the case study, it is crucial to emphasize that the full system simulation is used exclusively for retrospective validation of the co-simulation, without incorporating its results as inputs or convergence criteria. The proposed method significantly reduces the average error between co-simulation results and the full system output voltage, decreasing it from -2.8 dB to less than -26.2 dB. This demonstrates improved alignment and faster convergence compared to using the WR method. The validation of GA method is then applied to the co-simulation of an electrical (buck converter) and mechanical (DC motor) system, with results compared against the full system. The WR method exhibited significantly lower power efficiency (57.4%) compared to the full system (81.4%), rendering it insufficient. Time windowing WR enhanced power efficiency through simulation segmentation, reaching 74.6%, though it still fell short of the full system. The most advanced approach, time windowing WR with GA optimization, dynamically adjusted relaxation parameters, resulting in a power efficiency of 80.8%, nearly matching the 81.4% recorded in the single-kernel simulation. These findings underscore the effectiveness of integrating time segmentation with adaptive optimization to enhance simulation performance
Granular flow enhancement in a model silo by using a pedant mobile obstacle
No full textInternational audienceIt is well established that placing an obstacle near a silo outlet reduces the clogging probability in systems approaching the jamming zone, even enhancing the flow rate when the obstacle is optimally positioned. Typically, studies have focused on fixed obstacles in 2D-silo models, using spherical particles, and the underlying mechanisms driving flow rate improvements remain a topic of ongoing research. We investigate experimentally the impact of a pendant mobile obstacle on the discharge flow of lentils using a rectangular flat-bottomed silo with a thickness of several particles. Even when the silo is inside the continuous flow regime, we still observe flow maximization for an optimal obstacle height. By selecting appropriate scaling lengths, we achieve a collapse of the flow rate curves for all aperture sizes studied. Our results indicate that different silo configurations exhibit distinct flow correlations, whose type and extent are crucial for flow rate maximization. Velocity profiles indicate that the obstacle increases particle velocity in the lateral channels surrounding the obstacle. Beyond the optimal height, this effect diminishes, and a sharp drop in velocity is found. This is the first experimental confirmation of previous numerical studies. An analytical model using free-fall particle behavior to describe the flow in the lateral channels provides a good representation of the discharge rate
Mating system and the evolution of recombination rates in seed plants
No full textInternational audienceMeiotic recombination is a central mechanism underlying sexual reproduction among eukaryotes. In many species, the recombination rate is strongly constrained by chromosome size, as the number of crossovers per chromosome generally ranges between one and no more than a few (around three to five). Yet, recombination rates are variable and can evolve between species, in particular when they differ in their reproductive system. According to theory, indirect selection towards higher recombination rates is expected to be stronger in inbred populations, such as selfing species compared with randomly mating species. To test for the impact of the mating system on the evolution of recombination rates, we leveraged a dataset with genetic maps, genome sizes, chromosome numbers, and life history traits in 200 seed plant species. After controlling for the chromosome size effect, the phylogeny, and map quality, we found a joint positive effect of the mating system and longevity on recombination rates, with higher recombination rates in mixed-mating and selfing species. We also found that mixed-mating and selfing species had a significantly higher number of crossovers in larger chromosomes than outcrossing species, suggesting selection for relaxed crossover interference in these former species. Our results point to the mating system as an important factor potentially shaping the evolution of recombination despite mechanical constraints acting on the number of crossovers per chromosome
Les opérations militaires d’Auguste : attaque et destruction des oppida de la frontière sud des Cantabri. Les cas de Monte Bernorio et de La Loma (Nord de la péninsule Ibérique)
No full textInternational audienceLas operaciones militares de la conquista del territorio meridional de los cántabros por las tropas de Octavio Augusto durante las primeras campañas de las Guerras Cántabras (26 o 25 a.C.) han dejado un registro arqueológico excepcional en las montañas cantábricas. En el siglo I a.C., el oppidum de Monte Bernorio (Pomar de Valdivia, Palencia) debió ser uno de los principales centros urbanos de los Cántabros, lo que explica su destacado papel en el transcurso de las Guerras Cántabras. El Conjunto Arqueológico de La Loma (Santibáñez de la Peña, Palencia) consiste en los restos de un asedio al oppidum por el ejército romano. Gracias a los trabajos de prospección y excavación basados en conceptos de la Arqueología de los Campos de Batalla desarrollados en las últimas dos décadas, se ha conseguido conocer en detalle las estrategias de asedio, conquista y destrucción de ambos oppida. Los trabajos de campo han permitido recuperar una importantísima colección de materiales militares romanos e indígenas de todo tipo: proyectiles de artillería, flechas, fragmentos de las armas, equipamiento e indumentaria personal. También se han estudiado las infraestructuras de asedio romanas y las propias fortificaciones de los yacimientos indígenas. En el interior de los oppida, la destrucción de estos núcleos dejó sellado un enorme registro de restos que nos da información sobre la vida cotidiana, la economía, la sociedad y algunas prácticas rituales de la población.Les opérations militaires menées par les troupes d’Octave Auguste pour la conquête du territoire méridional des Cantabres lors des premières campagnes des Guerres cantabres (26 ou 25 av. n. è.) ont laissé énormément de traces archéologiques dans les montagnes cantabriques. Au Ier siècle av. n. è., l’oppidum de Monte Bernorio (Pomar de Valdivia, Palencia) devait être l’un des principaux centres urbains des Cantabres, ce qui explique son rôle majeur dans le déroulement des Guerres cantabres. L’ensemble archéologique de La Loma (Santibáñez de la Peña, Palencia) correspond aux vestiges d’un siège de l’oppidum par l’armée romaine. Grâce aux travaux de prospection et de fouille, basés sur les principes de l’archéologie des champs de bataille développés au cours des deux dernières décennies, les stratégies de siège, de conquête et de destruction de ces deux oppida ont pu être étudiées dans le détail. Les recherches sur le terrain ont permis de recueillir une collection importante de matériaux militaires romains et indigènes de toutes sortes : projectiles d’artillerie, flèches, fragments d’armes, équipements et vêtements personnels. Les infrastructures de siège romaines ainsi que les fortifications des sites indigènes ont également fait l’objet d’études approfondies. À l’intérieur des oppida, la destruction de ces centres a scellé une grande quantité de vestiges, fournissant des informations sur la vie quotidienne, l’économie, la société et certaines pratiques rituelles de la population
How teacher autonomy support and student creativity jointly contribute to self-regulated learning: a dynamic, person-environment fit perspective
No full textInternational audienceAccording to emergent research, being creative at school could benefit self-regulated learning, but only within "creative learning" contexts that encourage student creativity. This study explored these relations among vocational students in high school (N = 8224). Theoretically, it merged creativity research and self-determination theory (Ryan & Deci, 2020) by operationalising creative-supportive contexts as teaching that supports the need for autonomous learning. Methodologically, the study investigated reciprocal influences between student perceptions of creativity (i.e., use of creative cognitive processes while studying), teacher autonomy support (i.e., teacher behaviours that foster autonomous learning behaviour) and self-regulation (i.e., regulation of resources, efforts, motivation in learning activities), while accounting for different temporalities of effects (i.e., lagged vs. contemporaneous) and for the possibility that self-regulation</div
