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New Neandertal remains from Sirogne Cave (Lot, France): implications for human evolution and behavior prior to the last interglacial
No full textInternational 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
La pédagogie par projet au service de la diminution de déchets alimentaires
No full textInternational audienceProject-based learning has proven effective in developing students’ skills and knowledge. To address an international challenge on resource preservation, this method was applied with professional bachelor’s students and engineering students. Each year, 10 million tons of food are wasted in France, at every stage from production to consumption. In this context, this work presents the technical validation of an automatic potato sorting system. The “good” potatoes are intended for human consumption, while the “bad” ones (showing black spots) are destined for animal feed. This challenge was met through a solution based on artificial intelligence. Supported by various partners, after a selection phase for the Xplore 2023 international challenge and eight months of work, the outcome is a true pedagogical, technical, and human success.L'apprentissage par projet a prouvé son efficacité pour développer les compétences et les connaissances des étudiants. Pour répondre à un défi international sur la préservation des ressources, cette méthode a été utilisée avec des étudiants en licence professionnelle et des élèves ingénieurs. Chaque année, 10 millions de tonnes de nourriture sont gaspillées en France, à toutes les étapes de la production jusqu’à la consommation. Dans ce contexte, ce travail présente la validation technique d'un système de tri automatique de pommes de terre. Les pommes de terre "bonnes" sont destinées à la consommation humaine, et les "mauvaises" (présentant des tâches noires) à l’alimentation animale. Ce défi a été relevé avec le concours d’une solution basée sur l’intelligence artificielle. Soutenu par divers partenaires, après une phase de sélection pour le challenge international Xplore 2023 et huit mois de travail, le résultat est un vrai succès pédagogique, technique et humain
Characterization of a heterogeneous limestone vadose zone based on a multimethod and multiscale geophysical approach
No full textInternational audienceWater resources are a critical societal issue. As they are more and more limited, their distribution, usage and contamination are of vital importance. In the Beauce region, there are concerns on both the water quality and quantity because of farming and the related groundwater contamination. Since water is a vector of contamination, these questions require a precise vadose zone water content characterization considering the site lithology and water content heterogeneities. We apply a multiscale and multimethod geophysical approach to integrate the limestone heterogeneity at various scales into the characterization. In the first step, at a multi‐decametric scale, the joint interpretation of a 3D surface nuclear magnetic resonance water content, electrical resistivity and chargeability models allows to distinguish zones with limestone heterogeneities (clay content, fractures) related to geophysical anomalies. At a decimetric scale, the joint interpretation of borehole nuclear magnetic resonance water content, borehole electrical resistivity and density logs in each zone allows us to precise the spatial fractures and karstification levels in the lower saturated and unsaturated limestone. The second step is to analyse the water content variations to build a water content model of the Beauce limestone. This model goes further into the site porosity description by illustrating how the different limestone water‐filled porosities are sensed by geophysical investigations. It is compatible with the known regional specific yield range, with laboratory data and with a previous dynamic evaluation of water column variation during a recharge seasonal episode at field scale. This shows that our preliminary model may be exportable to other calcareous settings and can be used as a basis to study and simulate the vadose zone dynamic
Blind test sur les musiques de fête, ouverture du festival d'histoire populaire de Créteil
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Reconstituer les phases d’exploitation d’une mine d’argent médiévale : apport croisés de la dendrochronologie et de la dendroanthracologie (Vallauria, Alpes-Maritimes)(Vallauria, Alpes-Maritimes)
No full textInternational audienceAvant l’introduction de la poudre au début du XVIIe siècle, l’extraction de minerais dans les roches dures reposait sur la technique de l’abattage par le feu. Cette méthode exigeait d’importantes quantités de bois, en particulier lors de l’exploitation de gisements de grande envergure. Une telle consommation a très probablement eu un impact significatif sur les écosystèmes forestiers environnants, en modifiant leur composition, leur structure et leur dynamique.Pour évaluer précisément les effets environnementaux de ces activités minières, il est essentiel de reconstituer la chronologie et l’intensité de l’exploitation, tout en identifiant d’éventuelles stratégies mises en place pour une gestion durable des ressources en bois. Bien que nombreuses, les datations par radiocarbone ne permettent ni de cerner avec exactitude le début et la fin de l’activité minière, ni de détecter d’éventuelles interruptions ou reprises.Par ailleurs, l’analyse des restes carbonisés requiert l’élaboration de référentiels dendrochronologiques adaptés, afin d’identifier les essences utilisées avec précision.Pour surmonter ces limites méthodologiques, nous avons mené une étude sur la mine médiévale de plomb argentifère de Vallauria, située entre 1465 et 1570 mètres d’altitude dans les Alpes-Maritimes (commune de Saint-Dalmas-de-Tende). Cette recherche a combiné l’analyse dendrochronologique des restes ligneux prélevés in situ avec la création de référentiels spécifiques pour le Sapin blanc et le Mélèze d’Europe. Ces référentiels ont été construits à partir de 38 troncs et 112 branches prélevés sur des arbres vivants, répartis sur huit placettes dont la fertilité a été estimée par des relevés phytoécologiques.Au total, 1572 charbons et 61 fragments de bois ont été analysés, 681 diamètres ont été restitués (dont 272 Sapin blanc et 409 mélèzes et/ou épicéas) et 187 branches ont été identifiés pour 360 troncs. Les diamètres reconstitués varient de moins de 1 cm à 19 cm pour les branches, et de 3,7 cm à plus de 20 cm pour les troncs. Parmi ces échantillons archéologiques issus de bûchers d’abattage, 42 ont pu être datés, permettant d’établir six séries chronologiques : cinq chronologies de mélèze couvrant les XIe et XIIIe siècles, et une de sapin correspondant au XIIIe et au début du XIVe siècle.Ces résultats indiquent une exploitation complète des arbres abattus afin de répondre aux besoins en combustible des activités minières. L’estimation des cernes manquants sur les bois de branches a permis d’approcher l’année d’abattage et d’affiner les chronologies. Les datations dendrochronologiques montrent que l’activité minière principale s’est déroulée entre les XIe et XIIe siècles, tandis que des datations plus récentes pourraient témoigner de tentatives de reprise avortées.Ces résultats partiels soulignent l’importance de poursuivre la construction de référentiels dendrochronologiques pour les conifères des Alpes du Sud. L’objectif est notamment de mieux estimer l’âge maximal des branches en fonction de leur diamètre, mais également en lien avec l’âge et le diamètre à hauteur de poitrine des arbres dont elles proviennent
Phu Lon and Back Again: Following the Steps of the Father of Holistic Southeast Asian Archaeometallurgy, Professor Vincent C. Pigott
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Surrogate modeling of interactions in microbial communities through Physics-Informed Neural Networks.
No full textInternational audienceMicroorganisms form complex communities known as microbiota, influencing various aspects of host well-being. The Generalized Lotka-Volterra (GLV) model is commonly used to understand microorganism population dynamics, but its application to the microbiota faces challenges due to limited bacterial data and complex interactions. This preliminary work focuses on using a Physics-Informed Neural Network (PINN) and synthetic data to build a surrogate model of bacterial species evolution driven by a GLV model. The approach is calibrated and tested on several models differing in size and dynamic behavior.Les micro-organismes forment des communautés complexes, des microbiotes, qui in uencent divers aspects de la santé de leur hôte. Le modèle de Lotka-Volterra généralisé (GLV) est couramment utilisé pour comprendre la dynamique des populations de micro-organismes, mais son application au microbiote se heurte à des di cultés dues au manque de données sur les bactéries et à la complexité des interactions. Ce travail so préliminaire se concentre sur l'utilisation d'un Physics-Informed Neural Network (PINN) et de données synthétiques pour construire un modèle approché de l'évolution d'espèces bactériennes décrite par un modèle GLV. Cette approche est calibrée et testée sur plusieurs modèles qui di èrent par leur taille et leur comportement dynamique
Integration of the exposome concept into health risk assessments: a challenge for health safety agencies
No full textInternational audienceThe exposome is a concept that aims to study the environmental factors to which individuals are exposed during their lifetime and the role of these factors in the development of chronic diseases. Since the concept emerged in 2005, new data, methods, and tools have been generated by the scientific community to assess the different components of the exposome and their impacts on human health. Currently, one of the main challenges is accounting for the diversity and complexity of exposures and their effects on health in risk assessment, which might be accomplished by integrating the exposome into this process. To this end, a working group was constituted by Anses to develop a strategy to integrate the exposome concept in risk assessment and more generally in the work produced by health safety agencies. We present the principal challenges to be addressed by considering 8 themes covering relevant aspects of the exposome and we made recommendations for each theme: 1) characterization of the exposome in epidemiological surveys; 2) exposome data; 3) risk assessment of chemical mixtures; 4) aggregation of multiple sources and routes of exposure; 5) dynamics of the exposure in the context of time, space, and social factors; 6) establishment of reference values; 7) multiple factors in risk, benefit and health impact assessment; and 8) eco-exposome. Then, we propose practical recommendations with short-, medium-, and longterm time scales to progressively operationalize the exposome into risk assessments implemented by health safety agencies. We also discuss how providing broader exposome input into risk assessment can support risk regulators to incorporate exposome input into risk management
How Can We Quantify the Mastery of the Gesture? Mechanical and Energetic Analysis of Coins
No full textInternational audienceMinting is the last step in the chaine opératoire of making coins. Coining by human power with a hammer is still practised in experimental archaeology. Yet, studies do not focus on the act itself. The small number of coins produced makes the problems associated with large-scale production invisible. Instrumentation of the coiner's gesture using a high-speed camera and a triaxial accelerometer will provide information about its performance. The energy required and the amount of movement at the moment of impact, a variable linked to the force of the impact, are thus evaluated after data processing. The ratio between these two values indicates the efficiency of the coiner. Correlated with the sharpness of the engraving, these quantities provide valuable information on production. It is therefore possible to determine the minimum force required to mint a coin and the energy required to do so. Relating this energy to a man's daily output gives a first approximation of the number of coins minted each day. Efficiency quantifies the know-how of the coiner. Experiments on Czech bracteates and Mellois deniers have demonstrated the effectiveness of this protocol
Caractérisation et contrôle du sillage proche d'un véhicule réel
No full textInternational audienceCaractérisation et contrôle du sillage proche d'un véhicule rée