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Retour aux sources. Les structures fondamentales des sociétés humaines, une thèse à discuter
No full textNational audienc
Le tourisme New Age, continuité ou alternative à la société urbaine ? Drifters, backpackers et néoruraux à San Mateo Río Hondo (Oaxaca, Mexique)
No full textInternational audienceTaking a social geography approach, the aim of this article is to complement the sociological critique of backpacker tourism regarding the illusion of a break with urban society. It seeks to demonstrate that New Age destinations, which combine psychedelic tourism with nature, are in fact extensions of a commodified, globalised urban life. After recalling the hippie origins (the ‘drifters’) of backpacker tourism in San Mateo Río Hondo (Oaxaca, Mexico), an analysis of the travel patterns and social profiles of tourists reveals social disparities that are nonetheless all imbued with forms of urban mobility. The authentic, alternative character of the New Age tourism offer is put into perspective by the commodification of tourism, which alters local traditions such as the ‘original hippy culture’. Lastly, this gradual development of tourism is leading to the settlement of former tourists, becoming ‘neo-rurals’, contributing both to the urbanisation of the villages and to the strengthening of the tourism supply.Dans une approche de géographie sociale, l’objectif de cet article est de compléter la critique sociologique du tourisme backpacker vis-à-vis de l’illusion de rupture avec la société urbaine. Il s’agit de montrer que des destinations New Age, combinant une offre touristique psychédélique et de nature, sont en réalité les extensions de la vie urbaine marchande et globalisée. Après avoir rappelé l’origine hippie (les drifters) du tourisme backpacker à San Mateo Río Hondo (Oaxaca, Mexique), l’analyse des rythmes de voyage et des profils sociaux des touristes montre des disparités sociales néanmoins toutes empreintes de formes de mobilité urbaine. Le caractère authentique et alternatif de l’offre touristique New Age est relativisé par la marchandisation touristique, qui altère les traditions autochtones comme la « culture hippie originale ». Enfin, cette progressive mise en tourisme participe à l’installation d’anciens touristes devenus néoruraux, ce qui contribue tout autant à l’urbanisation des villages qu’au renforcement de l’offre touristique
Effects of Pregnancy and Lactation on Bone Microstructure and Material Properties in a Rat Model of Bariatric Surgery
No full textInternational audienceObesity is a major public health issue worldwide. Despite various approaches to weight loss, the most effective technique for reducing obesity, as well as diabetes and associated diseases, is bariatric surgery. Increasingly, young women without children are undergoing bariatric surgery, vertical sleeve gastrectomy (VSG) being the most common procedure nowadays. However, despite several reports suggesting bone loss after VSG, little is known about the potential additive effects of gestation and lactation after VSG to bone health. This study investigated the combined effects of pre-gestational VSG and subsequent gestation/lactation on bone metabolism in a rat model fed a high fat high sugar (HFHS) diet, with a focus on bone biomechanics, mass, microarchitecture and material properties. Furthermore, bone mass and remodelling were followed longitudinally by microCT prior to surgery, 4 weeks post-surgery, after weaning and at sacrifice. Significant alterations in bone mass and microarchitecture, characterized by changes in trabecular thickness and number, as well as changes in bone formation and resorption were influenced by both surgery and reproductive demands. Mechanical testing at sacrifice demonstrated compromised long bone fragility, in rat with HFHS regardless of the surgical procedure (Sham or VSG). Furthermore, analysis of bone material properties highlighted potential disruptions in the pattern of bone mineralization in sham and VSG animals fed a HFHS diet. These findings underscore the complex interplay between pre-gestational VSG and subsequent gestation/ lactation in modulating bone metabolism in the investigated rat model. The preclinical rat model may help with optimizing surgical strategies and developing targeted interventions to mitigate potential bone-related complications associated with VSG in reproductive-aged individuals
Nouvelle méthode pour évaluation ultra-rapide d’exposition d’utilisateurs à des fréquences 5G/6G supérieures à 6 GHz basée sur fantôme eSkin
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Analyse du vieillissement hygroscopique à long terme de structures sandwichs composites biosourcés à l'aide de l'émission acoustique
No full textInternational audienceThis work investigates the long-term hygroscopic ageing behavior of bio-based sandwich structures with balsa core and glass fiber laminate skins, through the experimental characterization based on the water immersion test monitored by AE wave velocity measurement, as well as the numerical modeling based on the Dual-Fick diffusion model. Based on the relationships between moisture content, AE wave velocity and the stiffness of the sandwich, a new methodology considering AE was proposed to predict the stiffness degradation as a function of moisture content, as well as the localization of moisture content in the thin skin and the thick core. It is demonstrated that the bending stiffness decreases faster in the initial phase before the point at 80 % moisture content, while the strength reduces more quickly during the later absorption period under long-term aging conditions.Ce travail étudie le comportement du vieillissement hygroscopique à long terme de structures sandwichs biosourcées à âme de balsa avec des peaux stratifiées en fibre de verre, à travers la caractérisation expérimentale basée sur l'essai d'immersion dans l'eau suivi par la mesure de la vitesse de l'onde d'émission acoustique (EA), ainsi que la modélisation numérique basée sur le modèle de diffusion Dual-Fick. Sur la base des relations entre la teneur en eau, la vitesse de l'onde d'EA et la rigidité du sandwich, une nouvelle méthodologie compte tenu de l'EA a été proposée afin de prédire la dégradation de la rigidité en fonction de la teneur en eau, ainsi que la localisation de la teneur en eau dans la peau fine et l’âme épaisse. Il est démontré que la rigidité en flexion diminue plus rapidement dans la phase initiale avant le point à 80 % de teneur en eau, tandis que la résistance diminue plus vite au cours de la période d’absorption ultérieure dans des conditions de vieillissement à long terme
Étude de la consommation d’énergie et de la durée d’une reconfiguration d’un système cyber-physique au sein de la toundra arctique : de l’expérimentation sur infrastructure réelle à des simulations étendues
No full textCyber-physical systems (CPS) deployed in scarce-resource environments like the Arctic Tundra for in-situ and long-term observation face extreme conditions. Nodes deployed on the field are under a limited energy budget. To save energy and increase their lifetimes, nodes are forced to alternate between short uptime periods and long sleeping periods. Uptime schedules depend notably on observation tasks and are not synchronised.Nodes of the CPS may collaborate to provide services such as data aggregation, analytics, etc. Due to a lack of network infrastructure, nodes have to rely on peer-to-peer connections to communicate. Nodes are able to communicate only during uptime, when their uptime periods overlap. When dealing with short and non-synchronised uptimes, opportunities for communication can be very low. Due to the Arctic Tundra conditions, nodes of the CPS are forced to be autonomous for long periods (from 6 months to a year). During these periods, nodes of the CPS have to autonomously adapt to external events by reconfiguring their systems. Due to collaboration, reconfiguration of collaborative nodes must be coordinated. Due to scarce connectivity within the CPS and its isolation from external systems, a central authority is most of the time unreachable. Nodes must be able to coordinate their reconfiguration with other nodes in a decentralised manner. Due to scarce connectivity, coordinating such reconfiguration between nodes can impose a significant energy consumption overhead on nodes and take a long time to converge. This manuscript proposes to study the decentralised reconfiguration of a Cyber-Physical system with sleeping nodes. It provides a solution to define and coordinate the execution of decentralised reconfiguration programs between sleeping nodes. Based on this solution, it aims at extensively studying the performances in terms of energy consumption and duration of such reconfiguration according to the Arctic Tundra characteristics.Les systèmes cyber-physiques (CPS) déployés dans des environnements comme la toundra Arctique pour effectuer des observations de longues durées sur le terrain sont soumis à des conditions extrêmes. Les nœuds déployés sur le terrain ont un budget énergétique limité. Afin d'économiser leurs budgets énergétiques et augmenter leurs durées de vie, les nœuds sont forcés d'alterner entre de courtes périodes de fonctionnement et de longues périodes de sommeil. Les périodes de fonctionnement sont programmées selon les tâches d'observation des nœuds et ne sont pas synchronisées. Les nœuds du CPS peuvent collaborer pour fournir des services comme de l'agrégation de données, de l'analyse de données, etc. Dû au manque d'infrastructure réseau, les nœuds doivent communiquer en utilisant des connexions pair-à-pair. Les nœuds sont capables de communiquer durant leurs périodes de fonctionnement, lorsque ces périodes se chevauchent. Du fait que les nœuds se réveillent pendant de courtes périodes non synchronisées, les opportunités pour communiquer peuvent être très faibles. À cause des conditions de la toundra Arctique, les nœuds du CPS sont forcés d'être autonomes durant de longues périodes (de six mois à un an). Durant ces périodes, les nœuds du CPS doivent s'adapter aux évènements extérieurs de manière autonome en reconfigurant leurs systèmes. Du fait que les nœuds collaborent, cette reconfiguration doit être coordonnée. À cause du manque de connectivité au sein du CPS et de son isolation avec les systèmes extérieurs, une autorité centrale est la plupart du temps inaccessible. Les nœuds doivent être capables de coordonner leurs reconfigurations avec d'autres nœuds d'une manière décentralisée. À cause du manque de connectivité, coordonner une reconfiguration entre les nœuds pourrait imposer un coût supplémentaire significatif sur les nœuds et mettre beaucoup de temps à converger. Ce manuscrit propose d'étudier la reconfiguration décentralisée d'un CPS composé de nœuds dormants. Il fournit une solution pour définir et coordonner l'exécution décentralisée de programmes de reconfiguration entre noeuds dormants. En se basant sur cette solution, ce manuscrit a également pour objectif d'étudier de manière étendue les performances en termes de consommation énergétique et durée de la reconfiguration selon les caractéristiques de la toundra Arctique
Sens (89), Rue des déportés et de la résistance, Boulevard du Maréchal Foch, place des héros et boulevard du Mail. suivi archéologique des travaux d'extension du réseau de chauffage urbain.
No full text1 VOLUMECes dernières années, les travaux d’extension du réseau de chauffage urbain se multiplient sur le territoire national. En 2023, Engie Solutions et la ville de Sens ont lancé un vaste projet destiné à raccorder les collèges Mallarmé, Montpezat et Saint-Étienne. Pour ce faire, un tracé long de 783 mètres a été établi au travers de la rue des Déportés et de la Résistance, du boulevard du Maréchal Foch, de la place des Héros et du boulevard du Mail. Localisé en grande partie dans le secteur historique de la ville, l’ensemble du projet a alors fait l’objet d’une prescription de surveillance archéologique continue. Malgré des difficultés propres à l’exercice même des surveillances de travaux (tranchée étroite, visibilité réduite, co-activité, côte altimétrique arrêtée, etc …), ce type d’opération de sauvetage nous offre néanmoins la possibilité de documenter ponctuellement des vestiges diachroniques dans différents secteurs intra et extra-muros de la ville de Sens et ainsi d’évaluer plus précisément le potentiel de son patrimoine enfoui. Sur l’ensemble du tracé, c’est un peu plus d’une soixantaine de structures qui ont été mises au jour, allant de l’Antiquité à la période modern
Optimizing At production cross section by studying the rise of At cross section: First measurement using Linac SPIRAL2
No full textInternational audienceTargeted Alpha Therapy (TAT) offers a promising approach to treat cancer, particularly micrometastases, by utilizing the short range and high linear energy transfer of alpha particles emitted by radionuclides. 211At (half-life 7.2h) is one of the promising alpha emitters (only one alpha emitted during decay) that has been identified for nuclear medicine applications. It belongs to the halogen family and shares chemical properties with iodine, an element used for imaging (123I, 124I and 131I) and also widely used to treat thyroid cancer (131I). This chemical similarity enables the use of Iodine as an analogue for biodistribution and dosimetry studies while using 211At for treatment in a theranostic approach. In this study, an alpha beam accelerated by SPIRAL2, was used to produce 211At via the reaction 209Bi(α, 2n)211At on the NFS beam line. The production cross section of 211At increases with increasing alpha energy up to 31 MeV. However, above 28.6 MeV, the production of 210At occurs via the 209Bi(α, 3n)210At reaction. 210At decays to 210Po, a highly toxic alpha-emitting radionuclide with a half-life of 138.3 days which cannot be separated chemically. Therefore, it is crucial to have a thorough understanding of the rise in 210At production to optimize the generation of 211At while minimizing the production of 210At To achieve this, 209Bi targets were irradiated at various alpha beam energies between 28 to 31 MeV with high precision thanks to the characteristics of SPIRAL2 accelerator and 210,211At cross sections were measured by using γ-ray spectroscopy. The incident particle flux was monitored using an instrumented Faraday cup. This flux measurement combined with the number of detected γ-rays allowed to determine the production cross sections of 210,211At as a function of energy. The results are in good agreement with experimental values recommended by the International Atomic Energy Agency (IAEA) for 211At and provide supplemental data for 210At between 28.6 and 31 MeV. The data collected in this study will help optimize the energy range of interest for the production of 211At and give 211At its rightful place as a radionuclide for TAT. •At-211 production for Targeted Alpha Therapy.•Contaminant At-210 cross section measurement for At-211 production.•First measurement of At-210 using SPIRAL-2 Linac at GANIL.•Supplemental data for At-210 between 28.6 and 31 MeV
Performance and decision making in rugby union: Influence of team-based goals and task complexity
No full textInternational audienceAims: Success in rugby union games requires players to dynamically adjust their actions to the game situations. However, action selection might be influenced by players' social environment. This study investigates how individual and team-based motivational goals and task complexity affect rugby players' decision-making behaviour in a representative small-sided game. We hypothesised that priming a team-based goal would benefit performance and that ball carrier's action would differ between individual and team-based goal conditions only in complex game situations. Methods: A three against three rugby situation was designed with two levels of task complexity manipulated by setting two defensive conditions. The motivational goals (either individual or team-based) were primed by a cover story. Participants were 102 rugby players from elite training centres. Their performance during the games were analysed from video annotations of their actions and from their position on the pitch obtained with wearable GPS sensor data. Results: Contrarily to previous findings, performance was better when priming an individual goal. Players' decision was significantly influenced by the goal orientation. More precisely, when priming an individual goal, rugby players appear to be more responsive to available spaces for themselves, as suggested by the higher proportion of runs observed, and less responsive to available spaces for their teammates (and conversely when priming a team-based goal), especially in complex situations
Demand Response in power off-grid microgrids in Nigeria : a game theory approach
No full textInternational audienceMost developing countries continue to face challenges in accessing sustainable energy. This study investigates a solar panel and battery-powered system for an urban off-grid microgrid in Nigeria, where demand-side flexibility and strategic interactions between households and utilities can optimize system sizing. A nonlinear programming model is built using bilevel problem formulation that incorporates both the households’ willingness to reduce their energy consumption and the utility’s agreement to provide price rebates. The results show that, for an energy community of 10 households with annual energy demand of 7.8 MWh, an oversized solar-storage system is required (12 kWp of photovoltaic solar panels and 26 kWh of battery storage). The calculated average cost of 0.31 €/kWh is three times higher than the current tariff, making it unaffordable for most Nigerian households. To address this, the utility company could implement Demand Response programs with direct load control that delay the use of certain appliances, such as fans, irons and air conditioners. If these measures reduce total demand by 5%, both the required system size and overall costs could decrease significantly, by approximately one-third. This adjustment leads to a reduced tariff of 0.20 €/kWh. When Demand Response is implemented through negotiation between the utility and households, the amount of load-shaving achieved is lower. This is because households experience discomfort from curtailment and are generally less willing to provide flexibility. However, negotiation allows for greater flexibility than direct control, due to dynamic interactions and more active consumer participation in the energy transition. Nonetheless, tariffs remain higher than current market prices. Off-grid contracts could become competitive if financial support is provided, such as low-interest loans and capital grants covering up to 75% of the upfront cost