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Mise au point sur les compléments alimentaires
No full textInternational audienceThis article is the first in a series of articles on food supplements, written by a working group of the French Society of Nutrition (SFN) created in 2023. It introduces the subject by considering their official definition, characteristics, and potential benefits. It details the various risks associated with their consumption. These are often underestimated by consumers because dietary supplements are not intended to treat illnesses, but the risks are numerous and the consequences sometimes serious, justifying seeking the advice of a healthcare professional with proper training on the subject
Tendances conjointes des évolutions thermiques et hydrologiques des rivières : implications pour une gestion durable des écosystèmes et de la ressource en eau dans les bassins versants
No full textInternational audienceClimate change has dramatically increased river temperatures and altered the spatiotemporal dynamics of flows, posing challenges for ecosystem functioning and water resources for anthropogenic uses. This communication proposes an overview of the results from several coupled hydrology-thermal-fish community modeling projects, analyses of observations in the Loire basin and outline future directions. Firstly, sensitivity of streams and rivers to atmospheric warming will be discussed according to thermal and hydrological regimes, their size, the cumulative impacts of reservoirs and shading. In a second step, the evolutions of the co-occurrences of high temperature and low flow will be presented over 57 years (1963-2019) and during the 21st century based on climate scenarios. These associations evolved heterogeneously across the basin, becoming more frequent in the southern basin in both winter and summer. Results on three emblematic migratory fish species will be presented in connection with the counts at fish monitoring stations located on the Loire River, Allier, Vienne and Creuse streams, and highlighting the differentiated role of hydro-climatic conditions. Thirdly, the communication will provide the main scientific obstacles, in particular on the prediction of spatio-temporal heterogeneities in the river temperature and the role of groundwater exchanges. The analysis of thermal infrared images on the Arroux and the Bourbince streams during a heatwave event (41°C) and severe low water in July 2019, will introduce the notions of thermal refuge of cooler water and the need to better locate and characterize them. The increase in the frequency of low flow and high temperature episodes could compromise water availability for human activities, such as drinking water production, irrigation and cooling of nuclear power plants. These results highlight the urgency of adopting more holistic local adaptation strategies (water uses, biogeochemistry, connectivities) to be able to meet the ecological and water resource availability challenges related to climate change.Le changement climatique a fortement augmenté la température des rivières et a modifié la dynamique spatio-temporelle des débits, ce qui pose des défis pour le fonctionnement des écosystèmes et les ressources en eau pour des usages anthropiques. Cette communication se propose de faire le point sur les enseignements tirés de plusieurs travaux de modélisations couplées hydrologie-thermie-communautés piscicoles et d’analyses des observations dans le bassin de la Loire. Dans un premier temps la sensibilité différente des cours d’eau au réchauffement atmosphérique, sera discutée en fonction des régimes thermiques et hydrologiques, de la taille des cours d’eau, des impacts cumulés des retenues, de la végétalisation des berges. Dans un second temps, les évolutions des co-occurrences de température élevée et de faible débit, seront présentées sur les 57 années de suivis (1963-2019) et de scénarios pour la fin du XXIème siècle. Ces associations ont évolué de manière hétérogène à travers le bassin, devenant plus fréquentes dans le sud du bassin en hiver et en été. Des résultats sur 3 espèces de poissons migrateurs emblématiques seront présentés en lien avec les comptages réalisés sur la Loire, l’Allier, la Vienne et la Creuse, et soulignant le rôle différencié des évolutions hydro-climatiques. Dans un troisième temps, la communication donnera les principaux verrous scientifiques, notamment sur la prédiction des hétérogénéités spatio-temporelles de la température des cours d’eau et le rôle des apports d’eau souterraines. L’analyse des images infrarouge thermique sur l’Arroux et la Bourbince lors d’un évènement caniculaire (41°C) et d’étiage sévère de juillet 2019, permettra d’introduire les notions de refuge thermique d’eau plus fraiche et la nécessité de mieux les localiser et les caractériser. L’augmentation de la fréquence de ces épisodes de bas débit et de températures élevés pourrait compromettre la disponibilité en eau pour les activités humaines, telles que la production d’eau potable, l’irrigation et le refroidissement des centrales nucléaires. Ces résultats soulignent l'urgence d'adopter des stratégies d’adaptation locales, plus holistiques (usages, biogéochimie, connectivités) pour pouvoir relever les défis écologiques et de disponibilité des ressources en eau liés au climat
Semi-Empirical DFTB Parameters for Bromide Perovskites: Electronic Structure Predictions in 3D, 2D, and Heterostructures
No full textInternational audienceBromide-based perovskites have garnered considerable attention for their potential applications in optoelectronics and energy-related fields. However, reducing perovskite dimensionality from 3D to lower dimensions introduces challenges, especially with regard to quantum and dielectric confinement, which lead to larger band gaps and higher exciton-binding energies. Moreover, low-dimensional perovskite structures inherently require larger unit cells, making standard density functional theory (DFT) calculations computationally demanding. DFT can also significantly underestimate band gaps, posing additional obstacles in the accurate modeling of optoelectronic materials. Density Functional Tight-Binding (DFTB), a semi-empirical approach based on DFT, addresses these challenges by enabling simulations of large systems while offering reliable band gap predictions at reduced computational cost [1-2].In this work, we present DFTB parameter sets specifically designed to accurately predict the electronic properties of bromide perovskites in both 3D (e.g., CsPbBr₃, MAPbBr₃, FAPbBr₃), and 2D forms (e.g., Cs2PbI4, BA2PbI4, PEA2PbI4, and BA2PbBr4). Benchmark comparisons with experimental measurements confirm the robustness of our approach in accurate band gaps and reduced effective masses prediction against experimental value. This first attempt is promising and can be applied to other low-dimensional (1D, 0D, hollow) perovskite nanostructures and more complex 2D/3D bromide perovskite heterostructures, which have demonstrated excellent operational stability in solar cell architectures.References[1] B. Hourahine et al., J. Chem. Phys. 2020, 152, 124101.[2] J. Jiang, et al., 2024, arXiv preprint, DOI: 10.48550/arXiv.2412.07016
Towards interdisciplinary approaches combining AI and 2D/3D: Designing a digital environment for the virtual reconstruction of a lost medieval church using a historical ontology
No full textInternational audienceThis article explores the intersection of artificial intelligence (AI), 3D modeling, and historical ontology in the context of digital heritage. It presents an interdisciplinary methodology designed to enhance the accuracy and epistemological transparency of virtual reconstructions, using the lost Cordeliers Church of Nantes as a case study. Generative AI models, supported by curated databases and structured ontologies (OMeKA-S), are used to produce historically grounded visual hypotheses. The process includes source verification, bias analysis, and an iterative evaluation protocol by domain experts. The study also examines the ethical and methodological implications of using AI in the humanities, advocating for transparent, explainable, and human-centered AI workflows. By combining technical innovation with heritage expertise, this work offers a reproducible framework for digital museography and future research in the digital humanities
A Bundle of Interventions to Prevent Pressure Ulcers During Prone Position in Adult Patients With Acute Respiratory Distress Syndrome: Results of a French Stepped‐Wedge Randomized Controlled Trial
No full textInternational audienceBackground : In patients with moderate‐to‐severe acute respiratory distress syndrome, the frequency of pressure ulcers is higher in the prone position than in the supine position. Aim : To assess the effect of a bundle of interventions to prevent pressure ulcers in patients with acute respiratory distress syndrome prone. Study Design ESCARD is a stepped‐wedge prospective multicentre trial conducted in France that included patients with moderate‐to‐severe acute respiratory distress syndrome, intubated and with an indication for pronation. In the control period, patients received the routine means of each centre. In the experimental period, the bundle of specific standardized means included: eye protection with methylcellulose; strapped lower eyelids; 15° body inclination; specific cushions inserted between the mattress and head/thorax and knees/feet; head rotation every 4 h. The primary end‐point was the occurrence of a new pressure ulcer at any location and stage in the anterior part of the body 7 days after inclusion. It was assessed from pictures taken in the supine position and independently analysed by two experts blinded to the allocated period. Results From 16 April 2018 to 3 December 2020 (with an interruption between 12 March and 15 July 2020 because of COVID pandemic), a total of 160 patients were included in 9 centres; 156 were analysed. At the first proning session, all 6 specific preventive means were implemented in 1.2% of the patients in the control period and 91.8% in the experimental period. At Day 7, 53 patients (63.9%) in the control versus 40 (54.8%) in the experimental period had a new pressure ulcer at any location and of any stage (odds ratio = 0.92; 95% confidence interval [0.39; 2.18]). There was a 42.8% discrepancy between the two experts. Conclusions In this prospective multicentre stepped‐wedge trial, the bundle of interventions did not lead to a significant reduction in the frequency of new pressure ulcers in moderate‐to‐severe acute respiratory distress syndrome patients treated by prone position. Relevance to Clinical Practice The critical care nurses were able to manage patients enrolled in a complex trial up to its planned end. Even though negative, the study should encourage intensive care unit (ICU) nurses to better define the bundle of interventions including introducing other methods not used in the present study. ICU nurses should also assess the stage of pressure ulcers consistently over time. ICU nurses should consider further studies because pressure ulcer is a relevant issue of concern during the pronation in acute respiratory distress syndrome patients. If so, the new trial should include a larger number of ICUs. Trial Registration : The protocol was approved by an ethics committee (number 2017‐A01449‐44 on 7 October 2017) and was recorded in clinicaltrials.gov (NCT03125421
New challenges for research and science: What is at stake?
No full textInternational audienceNo abstract availabl
Analytical description of the radio Cherenkov cone
No full textInternational audienceRadio emissions from extensive air showers (EAS) provide a valuable tool for detecting ultra-high-energy (UHE) astroparticles. In this context, several radio arrays focus on detecting highly inclined EAS, as this enables the observation of Earth-skimming UHE neutrinos, in addition to cosmic rays and gamma rays. The reconstruction of such inclined events relies heavily on a thorough understanding of the radio features observed on the ground, with the Cherenkov cone being one of the most prominent. In this study, we demonstrate that the Cherenkov cone can be accurately described for inclined air showers using basic propagation principles. Furthermore, we have developed an analytical model that computes the expected opening angles of the cone and reproduces the asymmetry effects observed in simulations. The high accuracy of these computations can enhance current reconstruction methods and pave the way for the development of new ones
Public‐health implications of market drug withdrawals: A focus on antifungals for tinea capitis
No full textInternational audienc
Intermediate-Dose Cytarabine as Postinduction AML Therapy
No full textInternational audienceBackground: We conducted a randomized controlled trial to compare intermediate doses (IDAC) with high doses of cytarabine (HDAC) as postinduction therapy in patients 18 to 60 years of age with newly diagnosed acute myeloid leukemia (AML). The main objectives were to evaluate noninferiority in overall survival (OS) after IDAC and safety.Methods: Patients 18 to 60 years of age with newly diagnosed AML, except those with core-binding factor, acute promyelocytic, Philadelphia chromosome-positive, or post-myeloproliferative neoplasm AML, were eligible. After the induction course, we randomly assigned patients to either IDAC (1500 mg/m2/12 hours) or HDAC (3000 mg/m2/12 hours). Patients with intermediate- and adverse-risk AML were eligible for allogeneic hematopoietic stem cell transplantation (HSCT) in first remission. The primary end point was OS in a predefined per-protocol analysis population. The primary analyses were performed in 1132 randomly assigned patients, with a noninferiority outcome adjusted on the European Leukemia Net (ELN) 2022 risk group, the use of induction anthracycline, the response to induction, and HSCT as a function of time following treatment.Results: At 5 years, OS was estimated at 59.3% (95% confidence interval [CI], 55.0 to 63.3) in the IDAC group versus 57.5% (95% CI, 53.3 to 61.5) in the HDAC group (adjusted hazard ratio, 0.96; 95% CI, 0.80 to 1.15; noninferiority test, P=0.0042). A preplanned analysis was unable to detect any interaction between IDAC or HDAC treatment effect and patient subgroups, including those defined by the ELN 2022 risk group or response to induction prior to random assignment. In addition, the severity of chemotherapy-induced myelosuppression and the incidence of related adverse events were lower after IDAC.Conclusions: Our trial shows noninferior outcomes in patients 18 to 60 years of age with newly diagnosed AML treated with low- versus high-dose cytarabine; this occurred with similar or lower toxicities.(Funded by the Regional Clinical Research Office, Angers and others; EudraCT number, 2014-000699-24; ClinicalTrials.gov number, NCT02416388)
Rapports de classe dans un espace insulaire touristifié. Le cas de Belle-île-en-mer (Morbihan)
No full textInternational audienceA l’instar des littoraux bretons, la mise en tourisme de Belle-ile-en-mer a renforcé la transformation des rapports de classe dans cet espace social local (Bruneau et al., 2018), historiquement tourné vers les activités halieutiques et agricoles. Cette attractivité renouvelée (Buhot, 2006) a eu pour conséquence de générer des tensions, concurrences et conflits pour l'appropriation de l'espace (Ripoll et Veschambre, 2006), et plus particulièrement pour l’accès au logement. Selon les données récentes de l’INSEE (Cazenave et Lardoux, 2024), le parc de logement à Belle-ile-en-mer est composé à plus de la moitié de résidences secondaires (jusqu’à près de 70% pour Locmaria, l’une des quatre communes de l’ile), dont plus de 50% des propriétaires disposent d’un revenu annuel supérieur ou égal à 60°000 euros (contre 36% pour l’ensemble de la région bretonne). Cet embourgeoisement de l’ile participe à l’inflation immobilière qui réduit l’offre de biens à la location ou à l’achat destinée aux classes populaires, dont les emplois sont pourtant nécessaires à l’économie de villégiature. Ce processus de gentrification atypique des « volets fermés » (collectif Douarnenez, 2023) est accentué par le développement des meublés touristiques ces dernières années via les outils dématérialisés du capitalisme de plateforme. Par ailleurs, en raison des contraintes géographiques propres aux espaces insulaires, les classes populaires ne peuvent pas recourir à des stratégies de repli résidentiel comme dans les communes rétro littorales bretonnes (Brieuc et Bisson, 2024). Face à la configuration d’un « espace contradictoire » (Marie Dit Chirot, 2017), la communauté de communes de Belle-ile-en-mer a pris des mesures visant à favoriser l’habitat à l’année et le logement des travailleur.ses sainsonnier.es. Outre la construction de logements sociaux et l’augmentation de la taxe sur les résidences secondaires, les élu.es ont récemment adopté des règlements municipaux permettant de limiter drastiquement la location des meublés touristiques : au-delà d’une location autorisée par foyer, toute unité supplémentaire mise en tourisme doit être compensée par un logement proposé à un.e résident.e à l’année. L’objectif de cette proposition de communication est de présenter les ambitions (et les premiers résultats) d’une recherche portant sur les rapports sociaux de classe dans une espace insulaire touristifié. En associant observations et entretiens, la démarche ethnographique souhaite plus particulièrement être attentive aux circulations et trajectoires socio-résidentielles d’habitant.es multisitué.es, entendu.es comme des acteur.trices « ordinaires » de la gentrification. L’enquête vise tout d’abord à appréhender les positions de classe qui se cristallisent autour de la régulation des meublés de tourisme, entre une bourgeoisie rentière multipropriétaire et des élu.es s’érigeant en défenseur.ses des résident.es permanent.es et des travailleurs saisonnier.es. Il s’agit ensuite d’observer les modes de (co-)habitation dans l’espace social local durant les périodes de forte affluence, qui mettent en coprésence des résident.es secondaires, fortement doté.es en capitaux économiques et culturelles, et des résident.es permanent.es, détenteur.trices d’un capital symbolique adossé/articulé à un capital social (Ripoll, 2023). Entre l’échelle insulaire où s’exprime le conflit pour l’appropriation légitime de l’espace et l’échelle micro locale où s’agencent des formes de coexistence, de coopération voire d’alliance entre classes sociales, la recherche s’attache enfin à analyser sur le temps long la trajectoire socio-résidentielle d’ilien.nes issu.es des classes populaires. Pour certain.es d’entre eux et elles, leur ascension sociale s’est opérée au prix d’une mobilité géographique sur le « continent », les amenant au cours de leur carrière professionnelle à valoriser le(s) bien(s) immobilier(s) hérité(s) sur l’île, participant par conséquent à l’embourgeoisement de l’espace insulaire