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Influence de la valence émotionnelle des mots sur l’acquisition de l’orthographe lexicale chez les enfants de 6-7 ans
No full textThis research examines the influence of the emotional valence of words on the performance of 6- to 7-year-old students in lexical spelling. Although the scientific literature recognizes that emotions play a role in learning, few studies have explored their influence on lexical spelling. Following an experiment based on a dictation task and a delayed copying task, the results demonstrate that words with an emotional valence (positive or negative) optimize spelling memorization, unlike neutral words. This study invites the teaching community to integrate emotional valence into the choice of teaching materials, while taking into account the cognitive load of students.Ce mémoire de recherche interroge l’influence de la valence émotionnelle des mots sur les performances des élèves de 6 à 7 ans en orthographe lexicale. Bien que la littérature scientifique reconnaisse que les émotions jouent un rôle dans les apprentissages, peu d’études ont exploré leur influence sur l’orthographe lexicale. Suite à une expérimentation basée sur une tâche de dictée et une tâche de copie différée, les résultats démontrent que les mots ayant une valence émotionnelle (positive ou négative) optimisent la mémorisation orthographique, contrairement auxmots neutres. Cette étude invite la communauté enseignante à intégrer la valence émotionnelle dans le choix des supports pédagogiques, tout en tenant compte de la charge cognitive des élèves
Experimental study on the aerodynamics of an oriented cube in supersonic flow at different Knudsen numbers
No full textInternational audienceThis study examines the aerodynamic behavior of oriented cubes exposed to supersonic flow conditions, with a focus on the effects of varying Knudsen numbers within the slip regime. Through a series of experiments in rarefied supersonic wind tunnels, we analyze how cube orientation influences drag and lift aerodynamic coefficients, as well as shock wave behavior, especially in terms of standoff distance. The experiments employed two diagnostic techniques -flow visualization and aerodynamic force measurements -to capture the flow dynamics around the cubes across different Knudsen numbers. The results offer valuable insights into the aerodynamic performance of oriented cubes with different incident angles in the slip-transitional regime during atmospheric entry, particularly enhancing the understanding of debris reentry dynamics and improving predictions of debris trajectories
Steroid anabolic and catabolic hormones in highly and recreationally trained female athletes across the menstrual cycle
No full textInternational audienceAbstract Sex hormone fluctuations across the normal menstrual cycle (NMC) may affect women's performance and health, but literature is sparse on the estradiol (E2) impact on anabolic and catabolic hormones and well‐being in female athletes. We therefore measured in 21 NMC anaerobically trained female athletes: 12 highly (HT) and nine recreationally (RT) during late luteal/early follicular (Low E2) and late follicular/peri‐ovulatory (High E2) phases: DHEAS, DHEA, androstenedione (A4), testosterone (T), sex hormone‐binding globulin (SHBG), cortisol, free androgen index (FAI = T/SHBG), and their relative ratios. Body composition and well‐being, assessed by positive and negative affects (PANAS), were determined in parallel. In High versus Low E2, subjects showed a significant percentage increase in T, A4 ( p < 0.001) and FAI ( p < 0.05), with high A4/T correlation ( r = 0.78), without any change in the other parameters. While no group difference was detected in hormone concentrations, HT versus RT subjects presented higher muscle mass and positive affects and lower FAI ( p < 0.05). In conclusion, T and A4 were modulated across NMC, probably resulting from a variable ovarian contribution, but without inducing any change in the anabolic/catabolic balance, regardless of the physical training level. However, high anaerobic training may enhance T sensitivity in view of the FAI, body composition and well‐being outcomes
The marble decor of the Temple of Mercury on Puy-de-Dôme (Auvergne, France) : ancient discoveries, new lens
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Asymmetric molecular-driven aluminum distribution and nanocrystalline assembly in BEA zeolite catalyst
No full textInternational audienceZeolites are critical materials in industrial catalysis, where optimizing both active site distribution and mass transport properties is essential for achieving high activity, selectivity, and stability. However, simultaneously controlling aluminum site placement and porosity during zeolite synthesis remains a fundamental challenge, limiting the rational design of next-generation catalysts. In this work, we present an intentionally moderated synthesis strategy that enables concurrent tuning of aluminum distribution and hierarchical structuring in nanosized Beta (BEA) zeolite, by employing an asymmetrical organic structure-directing agent (methyltriethylammonium, MTEA + ). Partial substitution of the conventional TEA + with MTEA + leads to stronger electrostatic interactions with aluminosilicates, which decelerate nucleation, modulate Al spatial distribution, and prevent dense nanoparticle aggregation during crystallization. The resulting BEA zeolite features a loosely assembled mesoporous architecture with framework Al atoms preferentially located near the external surface and occupying T7, T1, and T2 tetrahedral sites. This dual-level control over porosity and aluminum siting enhances catalyst performance in the methanol-to-gasoline reaction, offering improved lifetime and hydrocarbon selectivity. Overall, our findings provide a generalizable approach to tailoring both framework architecture and active site positioning of zeolite catalysts, opening new pathways for the design of advanced porous materials in hydrocarbon conversion and beyond
Board games in the elementary classroom : teachers’ perspectives
No full textInternational audienceBackgroundRecent research highlights the importance of developing children’s emotional and social competencies alongside academic knowledge and skills. Learning through play is a promising pedagogy that can contribute to children’s holistic development. Through playful pedagogies, children can develop social skills, cognitive abilities, and emotional competencies. Despite a global emphasis on learning through play, playful pedagogies tend to be less common in elementary schools than in pre-schools, and elementary school teachers rarely use them in their classrooms.PurposeAmong the diverse range of playful pedagogies, board games stand out as one particularly engaging activity for fostering pupils’ holistic skills during middle childhood (aged 5 to 11). This study aimed to contribute to a gap in knowledge between the reported benefits of board games for children’s academic learning, emotional, and social competencies, and the actual practices of elementary school teachers. We asked the following research questions: 1) What are teachers’ perceptions of board games?; and 2) What are the key factors shaping their integration into classroom practices?MethodsThe study was conducted in France and gathered qualitative data through four semi-structured focus groups involving 18 elementary school teachers across four elementary schools. Data were analysed thematically.FindingsAuthors identified four overarching themes: 1) teachers’ knowledge about board games, 2) teachers’ role in classroom board games and their academic benefits, 3) board games for emotion regulation and social competencies, and 4) enablers and barriers to the implementation of board games in elementary school.ConclusionWhile elementary school teachers see the potential of board games to enhance academic, social, and emotional competencies, they face several barriers to implementing board game practice in their classrooms. These include official educational recommendations, the decline of play – both at home and in schools, and a lack of resources
Stability and relaxometric characterization of a manganase(II) based macrocyclic complex containing malonate pendant
No full textInternational audienceIn this study, we report the thermodynamic, kinetic, relaxation and structural features of the Mn(II) complex formed with a newly synthetized O-pyclen ligand bearing a malonate pendant. The thermodynamic stability of [Mn(OPMMA)] is lower (pMn = 6.27) than that reported for the Mn(II) chelates of OPC2A2− (pMn = 8.69) and 3,9-PC2A2− ligands (pMn = 8.64), and it dissociates faster than those at physiological conditions (t1/2 = 2.1 min). This behavior can be related to the assymetric structure of the ligand and the presence of an unsubstituted N donor in the macrocycle. DFT calculations revealed a capped trigonal prismatic coordination geometry for [Mn(OPMMA)], involving the coordination of the macrocyclic donor atoms, the two carboxylates of the malonate pendant arm as well as an inner sphere water molecule to Mn(II). The relaxivity values of [Mn(OPMMA)] (r1p = 3.48 and r2p = 5.85 mM−1 s−1 at 20 MHz and 298 K, respectively) are slightly higher than those found for [Mn(OPC2A)] and [Mn(3,9-PC2A)]. The water exchange rate (k298ex = (22.1 ± 0.1) × 107 s−1) is 2–4-times higher than that of the [Mn(OPC2A)] and [Mn(3,9-PC2A)] complexes. The slightly higher rotational correlation time as compared to [Mn(OPC2A)] (τ298rH = 55 ± 3 ps vs. 40 ps) can be related to the less compact structure of [Mn(OPMMA)
Molecular and supramolecular routes to enhance Gadolinium-based contrast agents relaxivity: How far are we from the theoretical optimal value?
No full textInternational audienceGadolinium Based Contrast Agents (GBCAs) are routinely used in the clinical practice to enhance the diagnostic potential of MRI. Their contrast enhancing capabilities rely on their ability to increase the relaxation rate of tissue water protons. This property is expressed by the relaxivity, whose value is determined by structural, electronic and dynamic characteristics of the GBCA. Based on extensive experimental work over the past four decades and the well-established theory of paramagnetic relaxation, it is usually possible to correlate observed relaxivity values to specific molecular properties. Key determinants include the number of water molecules and/ or exchangeable protons in the first and second coordination spheres, their distance from the paramagnetic Gd 3+ ion, the ion's electronic relaxation time, molecular reorientation time, and the exchange rate of the coordinated water molecules. Understanding the key factors that affect relaxivity has enabled the design of systems with optimized structural and dynamic properties. However, some examples demonstrate exceptional relaxivity which cannot be fully explained by the established theory. In particular, GBCAs within confined environments show significant promise for developing high-relaxivity agents. Overall, one may state that nowadays it is possible to attain highly efficient GBCAs thanks to the in-depth understanding of the structural and dynamic determinants of their relaxivity, together with the optimization of their in vivo stability and biodistribution/excretion properties. This knowledge is crucial for the rational design of the next generation of MRI CAs. The domain of Molecular Imaging will also largely benefit from these efforts
Saccharomyces cerevisiae Mub1, a substrate adaptor of E 3 ubiquitin ligase Ubr2, modulates sensitivity to cell wall stressors through multiple transcription factors
No full textInternational audienceYeasts evolved a complex regulatory programme to build and maintain their cell wall, the primary structure through which they interact with their environment. However, how this programme ties to essential cellular processes mostly remains unclear. Here, we focus on Saccharomyces cerevisiae MYND‐type zinc finger protein MUB1 (Mub1), an adaptor protein of E3 ubiquitin‐protein ligase Ubr2 that was previously associated with regulating proteasome genes through the transcription factor Rpn4. We show that S. cerevisiae cells lacking Mub1 become hyper‐tolerant to standard cell wall stressors, outperforming wild‐type cells. This protective mub1Δ phenotype stems from the activity of several transcription factors, leading to the inhibition of cell wall remodelling, a typically protective process that becomes maladaptive during chronic cell wall stress in laboratory conditions. Based on these results, we suggest that Mub1 regulates not only Rpn4 but a much broader range of transcription factors, and thus serves as an in‐so‐far unrecognised regulatory hub directly linking cell wall robustness with the ubiquitin‐proteasome system
