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Oceanographic and hydroclimatic data explain depressed water level in the coastal karst hosting the decorated Paleolithic Cosquer cave (France)
No full textInternational audiencePaleolithic decorated caves are home to a priceless heritage, but their preservation depends on hydroclimatic conditions within the cave. In coastal areas, changing sea levels pose a further threat to caves, as the sea floods the karst and obliterates Paleolithic artefacts. In this paper, we study the case of the Cosquer Cave, a half-submerged coastal cave located in southeastern France, home to Upper Paleolithic archeological remains. This is a very special case, where the sea represents both an opportunity and a threat for the preservation of an archeological site. The cave is confined, submerged in its lower part, and embedded in a limestone massif with low permeability in the unsaturated zone. Several times a year, mainly in autumn, winter, and spring, air flows through the karstic massif, most likely below sea level, raising the cave's air pressure above atmospheric pressure. The resulting overpressure lowers the cave water level for weeks, keeping it below sea level and temporarily keeping the lowest wall paintings and engravings emerged. However, the oceanographic conditions that cause a pressurization event have not yet been described, although it is a key understanding to help preserve the natural heritage housed in the Cosquer Cave. Based on nine years of in situ continuous monitoring, we use descriptive statistics to decipher the oceanographic conditions controlling air inflow, air outflow, and absence of air flow through the submerged karst. We show that waves are the engine for the pressurization of the cave. The three main factors controlling air entrance are wave height, wave direction and seawater level. 90 % of air inflows coincide with significant wave heights exceeding 0.8 m. Additionally, air inflows are more efficiently caused by SSW and SW waves, propagating in a direction orthogonal to the cliff than by waves from the SE-SSE direction, propagating along the cliff. The minimum wave height required for air inflow to occur increases with sea-level rise, likely because submerged conduits become less accessible for air input. This study establishes a conceptual model of functioning for the natural hydrosystem of the Cosquer Cave, and provides the basis for further modeling and predictions according to scenarios of climate change and sea-level rise
Validating and refining a psychoacoustic test to diagnose hyperacusis
No full textInternational audienceDecreased sound tolerance refers to conditions like hyperacusis and misophonia, in which everyday sounds may provoke discomfort or distress. Hyperacusis is characterized by exaggerated loudness perception and aversive reactions to moderate to loud sounds, often leading to significant impairment. Despite its estimated prevalence of 10–15 %, no objective clinical test exists. Current assessment relies on interviews, questionnaires, and loudness discomfort levels (LDLs), which lack reliability and ecological validity. Recent work has shown that pleasantness ratings of natural sounds can differentiate individuals with hyperacusis from controls. A subset of seven natural sounds, termed Core Discriminant Sounds (CDShyper), was identified post-hoc as particularly effective, yielding 81 % sensitivity and 88 % specificity in prior lab-based testing. A similar approach for misophonia identified ten distinct trigger sounds (CDSmiso). This study aimed to validate a tablet-based version of the CDS test to diagnose hyperacusis prospectively. Forty-nine participants (20 with hyperacusis, 29 controls) completed the test that presented randomly CDShyper and CDSmiso sounds at 60, 70, and 80 dBA. Participants rated each sound presentation on visual analog scales for pleasantness and loudness. Hyperacusis was defined by clinical complaints, Hyperacusis Questionnaire scores (≥22), and LDLs (≤77 dB HL). Results showed that individuals with hyperacusis rated CDShyper sounds as significantly less pleasant (means score of 39 vs 25 for hyperacusis vs controls, p = .002, η² = 0.185) and louder (means score of 71 vs 63 for hyperacusis vs controls, p = .024, η² = 0.104) than controls. No group differences emerged for misophonia trigger sounds (CDSmiso sounds). The sensitivity and specificity for the combined CDShyper scores of pleasantness and loudness at detecting hyperacusis were 90 % and 69 %, respectively. These findings validate the tablet-based test as an efficient, ecologically valid tool for diagnosing hyperacusis
Culturable macroplastic-associated potential human pathogens in coral reef lagoons, Madagascar
No full textInternational audiencePotentially human pathogenic bacteria (PHPBs) have been detected in plastic-associated marine microbiomes, primarily through DNA-based methods. However, data on their culturability and concentrations on plastics remain limited, yet are essential to assess actual health risks. To address this gap, 70 floating macroplastic and 20 seawater samples were collected from two human-impacted reef lagoons in southwestern Madagascar (AtsimoAndrefana region). PHPBs were cultured from their microbiomes using selective media and quantified. Macroplastics were predominantly polypropylene (34 %) and polyamide (31 %). In increasing order of concentration, four culturable PHPBs, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Vibrio Harveyi clade species, were identified on both macroplastics and in seawater, across all sites and polymer types. Notably, 52 % of macroplastic samples harbored two PHPB species simultaneously, while only 7 % were PHPB-free. Concentrations of all PHPBs were consistently and significantly higher on macroplastics than in seawater, regardless of the measurement unit or polymer type, with the Vibrio Harveyi clade being the most abundant. No significant correlations were observed among PHPB species concentrations, suggesting limited interaction and independent colonization. These findings indicate that floating macroplastics may serve as reservoirs and fomites for viable PHPBs. However, their potential impacts on ecosystems and human health should be interpreted cautiously. We emphasize the need to contextualize PHPB concentration data by considering factors such as exposure pathways, environmental persistence, and bacterial virulence, rather than relying solely on concentration-based comparisons, which may lead to misinterpretatio
Multiple sclerosis, fertility, pregnancy, and assisted reproductive technology: Current knowledge
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Homogenization model for a dense elastic medium of cylindrical scatterers and based on a realistic pair correlation function
No full textInternational audienceMultiple scattering effects due to a random distribution of identical cylindrical inclusions in an elastic medium are investigated. The approach is based on the analysis proposed by Fikioris and Waterman. The solution of the developed modal equations yields the effective wavenumbers of elastic coherent waves. Attention is made in this paper to a more realistic description of scatterers’ distribution in the host medium: this distribution is taken into account in modeling by introducing the notion of pair correlation function. The existing Conoir and Norris approach has been established by using the Hole Correction as pair correlation function, which simplifies the description of scatterers’ distribution and may lead to unphysical results for dense media. New formulas for the effective wavenumbers are proposed here by generalization of the latter theory and enable the use of any pair correlation function for possible application to dense media. The new generalized analytical model coupled to a realistic pair correlation function is compared to the previous approach in different materials configurations and validated for concrete structures by comparison to numerical simulations
CLIP's Visual Embedding Projector is a Few-shot Cornucopia
No full textInternational audienceWe consider the problem of adapting a contrastively pretrained vision-language model like CLIP [30] for few-shot classification. The literature addresses this problem by learning a linear classifier of the frozen visual features, optimizing word embeddings, or learning external feature adapters. This paper introduces an alternative way for CLIP adaptation without adding "external" parameters to optimize. We find that simply fine-tuning the last projection matrix of the vision encoder leads to performance better than all baselines. Furthermore, we show that regularizing training with the distance between the fine-tuned and pretrained matrices adds reliability for adapting CLIP. This simple approach, coined ProLIP, yields state-of-the-art performance on 11 few-shot classification benchmarks, fewshot domain generalization, cross-dataset transfer, base-tonew class generalization, and test-time adaptation. Code will be made available at: https://github.com/ astra-vision/ProLI
Scalable model development of carbon photosynthetic assimilation and partitioning in a green microalga during nitrogen starvation
No full textInternational audienceLipid accumulation in green microalgae is induced by stresses (e.g. nitrogen starvation) which compromise photosynthetic activity resulting in significantly lower biomass productivity than under nutrient replete conditions. While algae photosynthetic growth has been well characterized and modelled under nutrient replete conditions, the loss of photosynthetic activity during nitrogen starvation lacks specific studies to determine suitable parameterisation. The loss of photosynthetic activity of the lipid-accumulating microalgae Chlorella vulgaris NIES 227 was studied under varying light intensities during nitrogen starvation. Partition of assimilated carbon between the different macromolecules pools (carbohydrates, lipids, and proteins) was concomitantly monitored. The results showed that the decrease of photosynthetic activity correlated well to the increase of cell C:N ratio = 0,883, =65) enabling to develop a model of microalgae growth and carbon partition under nitrogen starvation. Biomass dry-weight increase could be predicted with good accuracy ( = 0,940, = 66), as total lipid and carbohydrate production could also be predicted with fair accuracy (=0,841 and 0,618 respectively). The present study henceforth showed that modelling microalgae productivity based on photosynthetic activity inferred from local light intensity, as done in scalable models under nutrient replete conditions, may be extended to nitrogen starvation conditions and enabled the prediction of lipids and carbohydrates productivity. The model proposed should thus prove useful in optimizing photobioreactors design for the production of important energetic molecules based on light distribution knowledge
De Charlemagne à Robbe-Grillet: Entretien avec Roger-Michel Allemand, Président de la Société d'études robbe-grillétiennes
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Interfacial effects break the canonical permeability-selectivity trade-off in biological nanopores
No full textInternational audienceHypothesisTransport in membrane systems involves a classic trade-off between permeability (how many particles can pass through) and selectivity (the ability to sort specific particles) ruled by the pore size and the inner channel charges. By using interfacial effects from charges on the outer surface of the pore, it is possible to change the channel's conductive properties without altering its physical pore size. This suggests a new way to overcome the permeability-selectivity compromise in unexpected ways.Experiments and theoretical analysisWe perform an exhaustive electrophysiological analysis of the conductive properties of two wide biological ion channels, the bacterial porin OmpF from E. coli and the mitochondrial Voltage Dependent Anion Channel (VDAC), paying attention to the role of membrane lipid charges in the interplay between permeability and selectivity. We examine this interplay using an equivalent circuit model based on the principle of ionic current independence and with numerical simulations derived from Poisson-Nernst-Planck equations based on 3D protein structures at atomic resolution.FindingsWe demonstrate that membrane and pore charges do not compensate for each other. Rather, they function as complementary interaction sites giving rise to unique transport characteristics that can enhance simultaneously both permeability and selectivity beyond the predicted upper limit. Traditionally, efforts have concentrated on functionalizing inner channel surfaces; however, our findings highlight how separately modifying outer channel surfaces can enable nanofluidic devices to overcome the permeability-selectivity trade-off
Les stéréotypes de genre dans la littérature, les arts, les médias
No full textInternational audienceQuatrième de couvertureLes stéréotypes, ces cadres d’analyses du prêt-à-penser, structurent les rapports au monde, sans mot dire… tout en le disant.Ils imprègnent les cadres de pensée des sociétés humaines d’une teinte « commune » qui, pour n’être pas totalement invisible, tel l’éléphant au milieu de la pièce, n’en sont pas moins massifs.« À travers une approche pluridisciplinaire mêlant sociologie, histoire, littérature, philosophie, éducation et études féministes, les auteurs réunis ici proposent d’analyser les usages contemporains des stéréotypes, leur historicité, leur pouvoir de réification, mais aussi leur potentiel critique. ».Car le stéréotype n’est pas toujours stigmatisant. Il peut être mobilisé pour déconstruire et reconstruire… Dans un monde porté à la remise en question de concepts et de théories que l’on pensait – et subissait – immuablement, tels que le féminin, le genre, la « civilisation », la nature, etc., aborder la question des stéréotypes, de leur mobilisation, leur diffusion, leur usage, jusqu’à leur remise en question est un enjeu que les sciences humaines doivent aborder, en Corse, en Méditerranée, dans le monde.Les actes du présent colloque en constituent une première étape diversifiée, éclairante