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Energy and Waste
No full textThe Anthropocene epoch is defined by the profound impacts of human activity on natural ecosystems. Industrial processing of raw materials produces vast quantities of man-made matter including materials, wastes, and residues, which Harpet (2001) termed the rudosphere. Monsaingeon (2017) further introduced the term poubellocene to characterize this era of waste and a wasteful world (UNEP 2024). In France, the article L541-1 from the Environment Code defines waste as “any residue from a production, transformation, or use process, any substance, material, product, or more generally any good or piece of furniture that is abandoned or that its holder intends to abandon.” In other words, the term waste is generic, qualifying any element that is abandoned
Revisiting our primate roots in infants grooming
No full textInternational audienceGrooming is a common behavior across many animal species, including non-human primates (NHP), and serves a variety of functions, such as cleaning hair, alleviating stress, and enhancing social bonds. This study aims to explore whether groominglike behaviors are present in humans during early developmental stages, before the emergence of gestural and language communication. Through the observations of 67 preverbal infants, we identified frequent manual behaviors, including grasping, holding, and behaviors resembling grooming, particularly directed toward caregivers' hairy skin. These behaviors were analyzed and validated by twelve independent primatologists, who confirmed that behavioral sequences and their kinematics closely resembled grooming behaviors seen in NHPs, while also distinguishing them from other types of manual actions such as holding or grasping. Longitudinal analyses demonstrated a significant reduction in infants' grooming behaviors beginning at 8 months, with these behaviors no longer observed by 15 months, a developmental shift that coincided with the emergence of more sophisticated gestural communication. Interestingly, grooming frequency, but not other actions, peaked during a specific time window, between 2pm and 4pm, which corresponds with a well-documented circadian dip in beta-endorphins, a neurochemical associated with stress regulation and social bonding. This alignment points toward a potential physiological underpinning for the timing of these behaviors. These findings suggest that infant grooming behavior represents a vestigial motor pattern, likely reflecting conserved evolutionary mechanisms shared with non-human primates. This behavior may represent a primitive form of early social interaction, highlighting the role of ancient motor programs in shaping prelinguistic communication.</div
Perpendicular Magnetic Anisotropy in Thin Films Enables Extraordinary Spin-Wave Phenomena: Anti-Larmor Precession, Negative Reflection and Refraction, Multireflection and Multirefraction
No full textInternational audienceWe present a theoretical and numerical investigation of the role of perpendicular magnetic anisotropy (PMA) in shaping spin-wave (SW) dynamics under low magnetic fields in thin and ultrathin magnetic films. PMA introduces an in-plane torque that counteracts exchange, dipolar, and Zeeman contributions, fundamentally modifying SW dispersion and inducing a local minimum that, under specific conditions, becomes the lowest frequency across all geometric configurations. This results in a sombrero-shaped dispersion in ultrathin films and a cowboy-hat-like shape in thicker films, where dipolar interactions dominate. Using isofrequency contour (IFC) analysis, we demonstrate that these PMA-induced dispersion shapes enablenontrivial wave phenomena unprecedented in uniform media: bireflection and negative reflection in ultrathin films and trireflection in thicker filmswhere a single incident beam splits into three reflected components, two with negative angles. Most remarkably, we predict and demonstrate trirefraction, where one incident beam generates three refracted beams with two exhibiting negative refraction angles. We further show anti-Larmor precession of magnetization near the dispersion minimum in thicker films, arising from the interplay between PMA-induced and dipolar torques. Systematic simulations across diverse material systemsmetallic films, ferrimagnetic garnets, hybrid structures, and multilayers confirm the universal nature of these phenomena in any PMA system supporting stripe domain transitions. These results open new opportunities to explore wave phenomena beyond magnonics
Santé, maladie et bilinguisme dans l'Égypte byzantine : l'apport des glossaires gréco-coptes
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Ce que l’EPS fait à la socialisation des élèves allophones au collège. Anatomie de deux portraits sociologiques entre dispositionnalisme et contextualisme
No full textInternational audienceThis article analyses how the dispositions (to be, act and think) of two allophone and migrant students are activated/ inhibited, adjusted or reinforced in relation to intra-school contextes, such as PE, in a middle school in a priority education district. Based on an ethnographic study involving five months of on-site observations and eight biographical and/or semi-structured interviews, this study explores the sociological portraits of Andrei and Eva, who have recently arrived in France. Shaped by heterogeneous lifecourse experiences as well as singular family configurations and migratory projects, these two students are endowed with plural dispositions (social, gendered, scholastic and sporting) that is unequally influenced by the subject and, more broadly, by school. At PE level, peer groups, the enveloping support provided by teachers, the use of corporal demonstrations to underpin instructions or the deployment of learning, evaluative or competitive teaching situations all have multiple effects, both in terms of putting incorporated dispositions on standby/awakening them and in terms of adjusting or reinforcing them. The juvenile sociabilities that take shape in the interstices of the school and spread in PE, as well as the socializing experiences in other subjects, also deserve to be investigated in order to grasp the full complexity of their socialization in French schools.Cet article analyse comment les dispositions (à être, agir et penser) de deux élèves allophones s’activent/s’inhibent, s’ajustent ou se renforcent, en fonction des contextes intrascolaires, tels que l’EPS, dans un collège en réseau d’éducation prioritaire. À partir d’une enquête ethnographique couplant cinq mois d’observations in situ ainsi que huit entretiens biographiques et/ou semi-directifs, ce travail plonge dans les portraits sociologiques d’Andrei et d’Eva, récemment arrivé·es en France. Conditionné·es par des parcours de vie hétérogènes ainsi que des configurations familiales et des projets migratoires singuliers, ces deux allophones sont doté·es d’une épaisseur dispositionnelle (sociale, genrée, scolaire et sportive) inégalement travaillée par la discipline et, plus largement, au collège. À l’échelle de l’EPS, les groupes de pairs, l’accompagnement professoral enveloppant, l’usage de démonstrations corporelles pour étayer les consignes ou le déploiement de situations pédagogiques d’apprentissage, évaluatives ou compétitives, produisent des effets pluriels tant sur la mise en veille/en éveil de dispositions antérieurement incorporées, que sur leur ajustement ou leur renforcement. Les sociabilités juvéniles, qui se façonnent dans les interstices du collège et se diffusent en EPS, ainsi que les expériences socialisatrices dans les autres enseignements méritent aussi d’être sondées pour saisir toute la complexité de leur socialisation scolaire française
Satisfactory and Similar Outcomes after Knee Arthroplasty Revisions in One or Two Stages for Infection, Following a Surgical Strategy Based on Robust Guidelines
No full textInternational audienceBackgroundThis study aimed to assess the outcomes of a one-stage or two-stage strategy after total knee arthroplasty revision (RTKA) for periprosthetic joint infection (PJI). MethodsThis single-center retrospective study included all TKA revisions for chronic infection operated on between 2010 and 2021, with at least two years of follow-up. The surgical strategy was based on the recommendations from the Philadelphia Consensus 2018.Patients were classified into five overlapping groups: mechanical failure, septic failure, controlled infection, cure of infection, and complete healing. Revision was defined as the need for further surgery with implant removal. There were 218 RTKAs included, with 182 two-stage revisions (83.5%) and 36 one-stage revisions (16.5%). The mean follow-up was 56.9 ± 30.8 months. At the last follow-up, 135 patients (61.9%) were classified as “complete healing,” 30 as “septic failure” (13.8%), 12 as “mechanical failure” (5.5%), 147 (67.4%) as “infection-cured,” and 41 (18.8%) as “controlled infection.” ResultsThere were 27 patients (14.8%) who had had septic failure, and 11 (6.1%) had mechanical failure in the two-stage group, versus three (8.3%) and one (2.8%), respectively, in the one stage group (P = 0.36). There were 128 “R2” or “complex revision cases” (58.7%) and 90 “R3” or “salvage cases” (41.3%) according to the Revision Knee Complexity Classification (RKCC). In multivariate analysis, the requirement of a flap (OR [odds ratio] = 0.28, [0.11 to 0.72]), RKCC grade of R3 (OR = 0.37, [0.21 to 0.68]), and an ASA (American Society of Anesthesiologists) score > 2 (OR = 0.51, [0.28 to 0.93]) were associated with lower rates of infection healing.ConclusionFollowing a surgical strategy based on robust guidelines, one- or two-stage TKA revision for PJI achieved satisfactory rates of complete healing and cure of infection despite 41% of very complex cases. Patients classified as R3, those requiring a flap, and those who had an ASA score greater than 2 were at higher risk of failure
Replacer la dimension sociale de la mort au centre des débats de la société civile et des politiques publiques
No full textInternational audienc
Euclid preparation. Galaxy power spectrum modelling in redshift space
No full textInternational audienceAccurate modelling of redshift-space distortions (RSD) is essential for maximizing the cosmological information extracted from large galaxy redshift surveys. In preparation for the forthcoming analysis of the Euclid spectroscopic data, we investigate three approaches to modelling RSD effects on the power spectrum multipoles of mock H emission line galaxies. We focus on two one-loop perturbation theory models -- the effective field theory (EFT) and velocity difference generator () -- which differ in their treatment of the real-to-redshift space mapping on small scales, and a third approach, the BACCO emulator, which adopts a hybrid strategy combining perturbation theory with high-resolution N-body simulations. We assess the ability of these models to recover key cosmological parameters, including the expansion rate , the cold dark matter density parameter , and the scalar amplitude , across four redshift bins spanning . In each bin, we find that and BACCO outperform the EFT model across all scales up to . While BACCO saturates in constraining power at intermediate scales and higher redshift, the model continues to improve parameter constraints beyond . The EFT model, although robust on large scales, exhibits significant parameter biases for , limiting its applicability to Euclid-like H samples. Among the full perturbation theory-based models, the enhanced treatment of small-scale RSD effects in improves cosmological parameter constraints by up to a factor of two
Rhenium‐Based Dual‐Function Materials for Integrated CO<sub>2</sub> Capture and Methanation
No full textInternational audienceIntegrated CO2 capture and utilization (ICCU) is a promising transition route for mitigating flue-gas emissions while producing useful energy-carrying chemicals. This study reveals the potential of rhenium as an alternative to nickel or ruthenium for catalyzing CO2 methanation. It is shown that the mixing of Re/γ-Al2O3 with CeO2 or a synthetic hydrotalcite-derived Mg–Al oxide (layered double oxide [LDO]) provides tunable low-Re-content dual-function materials (DFMs) with 100% CO2 conversion and 100% methane selectivity at 300°C under cyclic operation. The direct deposition of rhenium, in an atomically dispersed form, onto CeO2 or LDO increases the methane yield up to 128 µmol/g per 10 + 10 min cycle, suggesting a synergy between catalytic and adsorbing functions. In contrast, these two systems are poorly selective to methane in conventional gas-phase CO2–H2 reaction, showing the beneficial effect of sequential adsorption–hydrogenation operation on selectivity. In terms of stability, Re/CeO2 appears as the most efficient DFM, showing stable methane production over 50 cycles, moderate deactivation in the presence of water, and full recovery after return to dry conditions. An operando diffuse reflectance infrared spectroscopy (DRIFTS) investigation of this catalyst under both ICCU and conventional hydrogenation discloses the nature of molecular adsorbates (CO, formates) and their dependence on the reaction regime. In situ Raman spectroscopy shows that the oxidation state of the active ReOx species undergoes only minor modifications upon alternating CO2 and H2 steps, maintaining predominantly Re7+ moieties