Le bilan carbone : outil de conformité, de connaissance ou de passage à l’action ? Une étude exploratoire dans les établissements de santé

International audienceMalgré le consensus autour de la nécessité de réduire nos émissions de gaz à effet de serre (GES), l’obligation, légale en France depuis 2010 pour les grandes entreprises et organisations publiques, de réaliser un bilan de ces émissions, est loin d’être remplie par toutes, sans que les causes de cette faible conformité soient entièrement claires. Le système de santé est concerné de façon particulière par les enjeux climatiques : d’un côté, ses émissions représentent une part non négligeable des émissions totales du pays, de l’autre, son activité (la demande de soins) est très sensible au réchauffement climatique et une augmentation de cette demande doit donc être anticipée. Face à ce double constat, la décarbonation des organisations de santé apparaît revêtir un enjeu particulier. Pourtant, ces dernières respectent aussi peu l’obligation de réalisation d’un bilan des émissions de GES que les autres organisations.Notre étude exploratoire auprès de cadres gestionnaires et dirigeants d’organisations de santé vise à appréhender la façon dont le bilan carbone est perçu et expérimenté. Elle montre que celui-ci, en cohérence avec la littérature existante, apparaît relativement peu maîtrisé et complexe à mettre en œuvre. Mais elle met aussi en avant les ambiguïtés d’une obligation réglementaire paradoxalement peu incitative, voire « désincitative ». Elle souligne enfin la dimension équivoque de l’outil et la façon dont il peut pâtir du fait d’être perçu comme un outil de connaissance bien plus que comme un outil opérationnel de passage à l’action

Game-Theoretic Interaction Control for Assistive Exoskeletons: a 2-DOF Simulation Study

International audienceEnhancing interaction control remains a key challenge for robotic devices designed to assist human movement. Interaction control can be modeled as a dyadic differential game, where both the human and the robot aim to minimize their respective cost functions over a finite time horizon. The difficulty lies in continuously estimating the human cost parameters to design an optimal game-theoretic robot controller. This simulation study evaluates the effectiveness and robustness of a bi-level optimization method in accurately recovering human cost parameters during a trajectory tracking task with a virtual 2-DOF exoskeleton

New Neandertal remains from Sirogne Cave (Lot, France): implications for human evolution and behavior prior to the last interglacial

International audienceWhile neighboring regions have yielded numerous Neandertal remains, few discoveries have been reported from the limestone plateaus of the Quercy region in France [1]. However, the accidental discovery in 2006 of a Neandertal-like hemimandible and a deciduous tooth by a speleologist in Sirogne Cave — located within a Jurassic karst system in the northern part of the Alzou Canyon near Rocamadour (Lot, France) — prompted six excavation seasons between 2013 and 2018. These aimed to better understand the chronology, modes of Neandertal occupation, and biological evolution of the populations using the site.The excavations clarified the context of the 2006 discovery and revealed a partially disturbed stratigraphy, affected by recent human interventions. Nevertheless, several preserved layers, covered by stalagmitic floors along the western wall of the cave, were identified. Most notably, nearly 100 human fossils were unearthed from the cave, representing at least 10 individuals: Three children (aged 3–8 years), two adolescents, three young adults, and two older adults. The remains include two hemimandibles (one immature, one adult), over 80 isolated teeth, and infracranial elements. Although most come from sediments affected by post-depositional processes, all exhibit unambiguous Neandertal features. Several infracranial bones show cutmarks indicative of dismemberment and disarticulation, suggesting complex mortuary behaviors. The reworked layers also contained faunal remains from over 20 taxa, reflecting a broad but clearly Pleistocene spectrum resulting from both natural and anthropogenic accumulations. More than 2,000 lithic artefacts in quartz, flint, and limestone were also recovered, pointing to at least two Paleolithic techno-complexes: one attributed to the Middle Paleolithic and another to the end of the Last Glacial Maximum. Moreover, Sirogne may correspond to the “Crozo del Dua” cave excavated in the early 20th century by André Niederlander, which yielded five isolated Neandertal teeth and a lithic assemblage [1-3]. Our reanalysis of his faunal collectionled to the identification of two additional Neandertal remains — a phalanx and a lower permanent canine — morphologically consistent with the Sirogne material. Combined geological, taphonomic, biochronological, and absolute dating of the stalagmitic floors and associated sediments place the Neandertal fossils within Marine Isotope Stage (MIS) 6, most probably at the end of the Middle Pleistocene (ca. 150,000–130,000 years ago), which represents a critical, yet poorly documented, phase in Neandertal evolutionary history [4].Morphometric analyses of the teeth and mandibles suggest that the Sirogne individuals are more closely aligned with early Neandertals (pre-MIS 5) than with later groups. They exhibit classic Neandertal features and share affinities with Middle Pleistocene fossils based on external dental dimensions, enamel-dentine junction (EDJ) shape, and non-metric dental traits. Additionally, the low inter-individual variation in EDJ morphology indicates significant biological homogeneity within the Sirogne group. This homogeneity appears even greater than that observed at the Krapina MIS 5e site (Croatia), possibly reflecting regional isolation during MIS 6. Altogether, this exceptional assemblage offers rare and crucial insights into 18 population dynamics and evolutionary processes during a key period in Neandertal history. The evidence supports a model of strong group structuring and complex demographic patterns in Europe prior to 120,000 years ago [4]. Further analyses are currently underway, including attempts at ancient DNA extraction, calcium isotope studies for dietary reconstruction, and SR-microCT imaging of dental microstructures to explore growth patterns and developmental stress. A new three-year excavation project will further refine the chronocultural context and clarify the processes underlying the accumulation of human remains at the site

The SCM instrument for the ESA Plasma Observatory mission

International audienceThe proposal of the Plasma Observatory mission was selected for a competitive phase A with two other missions in the framework of the seventh call for medium mission (M7) organized by ESA. The mission selection is planned in 2026 for a launch in 2037. Its main objectives are to unveil how are particles energized in space plasma and which processes dominate energy transport and drive coupling between the different regions of the terrestrial magnetospheric system? The mission consists of seven satellites, a main platform (mothercraft, MSC) and six smaller identical satellites (daughtercraft) evolving along an equatorial elliptical orbit with an apogee ~17 and a perigee ~8 Earth radii. The seven satellites will fly forming two tetraedra and allowing simultaneous measurements at both fluid and ion scales. The mission will include three key science regions: dayside (solar wind, bow shock, magnetosheath, magnetopause), nightside transition region (quasidipolar region, transient near-Earth current sheet, field-aligned currents, braking flow region) and the medium magnetotail (near-Earth reconnection region, fast flow formation region). Plasma Observatory mission is the next logical step after the four satellite magnetospheric missions Cluster and MMS. The search-coil magnetometer (SCM), strongly inherited of the SCM designed for the ESA JUICE mission, is only included in the Fields instrument suite of the MSC. SCM will be delivered by LPP and LPC2E and will provide the three components of the magnetic field fluctuations in the [0.1Hz-8kHz] frequency range, after digitization by the Low frequency Receiver (LFR) within the Field and Wave Processor (FWP), relevant for the three Key science regions. It will be mounted on a 6m boom and will allow to reach the following sensitivities [10-3, 1.5x10-6, 5x10-9, 10-10, 5x10-10] nT2/Hz at [1, 10, 100, 1000, 8000] Hz. Associated with the electric field instrument (EFI), SCM will allow to fully characterize the wave polarization and estimate the direction of propagation of the wave energy. These measurements are crucial to understand the role of electromagnetic waves in the energy conversion processes, the plasma and energy transport, the acceleration and the heating of the plasma.

2D fully kinetic simulations of dayside magnetic reconnection in the presence of cold ions and a moderate guide field.

International audienceThe standard conditions considered for magnetic reconnection to occur are usually antiparallel magnetic field configurations with a shear angle of 180◦. Reconnection is often observed with an additional out-of-plane component of the magnetic field (guide field). We performed two sets of 2D fully kinetic simulations using SMILEI code of asymmetric reconnection. The first set was performed initially by Dargent et al., 2017 with and without cold ions. While the second set with and without cold ions each conducted in the presence of a moderate guide field. The simulation domain size is set to (xmax , ymax) = (320, 128) di, enabling us to study these effects in the electron diffusion region (EDR) as well as the coupling across different scales, including ion diffusion region (IDR), outflow jets, and extended separatrices far from diffusion region. When the density gradient is combined with a guide field component at the magnetopause, it was suggested by Swisdak et al., 2003 that the electron diamagnetic drift governs the motion of the X-line.Our simulations reveal the development of an asymmetry in the reconnection plane as expected and a motion of the X-line in the opposite direction of the electron diamagnetic drift. This finding challenges the previously proposed explanation. We also report our progress in investigating the impact of cold ions in reinforcing the electron dynamics and further investigate the impact of adding a moderate guide field in their presence. These effects are expected to influence the energization, energy partitioning across scales, and potentially the suppression of reconnection. Fluid scales coupling with smaller ion scales aligns with the primary objective of the Plasma Observatory (PO) mission which aims to study plasma energization and energy transport. Our findings will contribute to the preparation of the PO mission and aim at improving its science return

Non‐Thermal Plasma Oxidation Processes for the Removal of Pharmaceuticals in Water: Diclofenac and Diclofenac/Carbamazepine Mixture

International audienceThe Non‐Thermal Plasma (NTP) process was studied for the removal of pharmaceutical pollutants (diclofenac (DCF) and carbamazepine (CBZ)) from water. In the individual treatment, at 0.2 W, showed 86% DCF and 63% CBZ degradation in 40 min, forming hydroxylated and nitro‐products. The same degradation efficiency was achieved for each compound in the mixed pollutant systems, and a complete degradation was attained after 90 min. By comparing the intermediate products, the formation of nitro‐products was higher in the mixed systems compared to their individual solutions treatment. The study concluded that NTP efficiency should be evaluated on pollutant mixtures rather than single compounds. Complementary biological analyses revealed the potential cell toxicity induced by generated products, highlighting the pertinence for toxicological analyses

Contextual cues and stance decision-making in tennis forehand professional tennis players

International audienceIn tennis, both open and square stances are used to produce forehands, although few differences have been found between them in terms of biomechanical or ball speed advantages. Hence, it is currently unclear why expert players decide to change their stance during rallies. The objective of this study was to analyze the influence of the context before the stroke on the players’ stance choice. Based on video analysis of men and women professional tennis matches, 2479 stances chosen by twenty players were recorded, considering contextual factors such as “balance of power” and direction of the ball to be played. Results revealed that open stance was used significantly more than square stance in 83.6% of the forehands, with no difference between women and men. These rates varied based on the balance of power, with fewer open stance during favorable situations (65.4%). The direction of the ball played influenced the choice of stance in favorable situations, with fewer open stance being used to play cross court. Taken all together, these results showed an interaction between factors preceding the forehand stroke when adopting a stance in tennis. When players had little time to make a choice, they overwhelmingly used open stances. This choice can be automated, which reduces the attentional load. On the other hand, when they had more time, they varied their type of stance according to the zone being played, with inter-individual differences. The findings could provide valuable insights for coaches to optimize training and improve players’ decision-making efficiency

First isotopic characterization of the planet neolithic Pb-Cu reduction workshop (Fayet/Cénomes mining district, aveyron, france)

International audienceExcavations at the Planet site have uncovered a substantial multi-stratified complex dedicated to copper and lead metallurgy, including several workshops that operated between 2850 and 2480 BCE. Situated in the southern Massif Central, near deposits rich in copper, lead, antimony, and silver, the site marks a significant development in early copper and lead metallurgy by late Neolithic communities. This article aims to enhance archaeological and mineralogical analyses of the metallurgical process by providing a first isotopic characterization of excavated materials, specifically key elements in the production chain: ores, slags, and metal. Additionally, we present an initial isotopic comparison of lead with samples from nearby deposits. This study deepens our understanding of the site’s local resource sourcing while establishing a preliminary reference framework for comparing analyses of contemporaneous artifacts from the region

Magnetotelluric evidence for a melt-rich magmatic reservoir beneath Mayotte

International audienceThe exact nature of crustal magmatic reservoirs is elusive as they cannot be sampled in situ. The traditional view that magma chambers contain essentially molten material has recently been replaced by the transcrustal magmatic system (TCMS), in which reservoirs are mostly composed of immobile magmatic crystals with a minute fraction of more mobile melt1,2,3, creating a ‘magmatic mush’3. Eruptions are possible if a significant portion of melt segregates into melt-rich lenses within the mush reservoir1,2,3. The TCMS concept is, however, a default model essentially justified by the absence of clear geophysical signatures of melt-rich magma chambers1,4, and by the rare and tentative estimates of the melt fraction in the crustal storage zones based on geochemical and textural analysis of eruptive products5,6. Here we image a bright electrical conductor at 23 ± 1 km below sea level beneath Mayotte island that we interpret as a magmatic reservoir, based on laboratory measurements of Mayotte’s melt conductivity. This large magmatic reservoir (more than 200 km3) contains a high melt fraction (22–42%). Such a crystal-to-liquid ratio matches the reconstructed differentiation paths7,8,9 producing the melts that recently erupted at Mayotte. This reservoir is possibly connected to the system that fed the large submarine eruption of Fani Maoré in 2018–201

Nigromancie et usages du corps humain aux derniers siècles du Moyen Âge

International audienceCette contribution compare le discours doctrinal que les théologiens et les inquisiteurs de la fin du Moyen Âge consacrent à la « nigromancie », où l’accent est mis sur les usages sacrilèges dont il est fait de parties du corps humain, mort ou vivant, en guise de sacrifices aux démons, à celui des textes de magie savante que l’on a conservés, qui donnent une image plus contrastée de ces pratiques, notamment pour ce qui concerne le sang, central dans la doctrine du pacte