Beach safety as a family affair: exploring the role of parents on young adolescents’ knowledge, bathing risk perceptions, and behaviours
Beaches are popular destinations among young adolescents despite the safety risks they may pose. This study aimed to explore how young adolescents are influenced by parents at the beach and how parental presence impacts both their risk perception and their self-reported risk-taking behaviour. We conducted a cross-sectional survey among pupils aged 11-15 years (n = 416) in a public high school in south-western France and assessed their sociodemographic characteristics, water-based recreational use, beach safety knowledge, risk perceptions, and risky behaviours. Pupils were also asked about their likelihood of entering the water outside of lifeguard-supervised areas, as well as their perception of risk, both with and without parental supervision. To analyse pupils' responses, we estimate two cumulative link mixed models with random intercepts for individuals. Two-thirds of pupils reported bathing outside supervised areas within the last 12 months. Just over half of the pupils were able to correctly define rip currents or supervised bathing areas. Our findings highlight the crucial but ambivalent influence of parents' behaviours as parental presence decreased the odds of declaring higher perceived risks and increased the odds of declaring higher willingness to enter the water. Older pupils declared lower perceived risks compared to younger ones, and males were more likely to report entering the water outside of supervised areas than females. Parents constitute the primary information source on water safety for young adolescents. Therefore, beach safety prevention messages should attempt to reach the entire family unit.
(Health Promotion International. vol. 41, n° 0957-4824, pp. daag144, 01/10/2026)
UR ETTIS, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Dynamic instability of the Wilkes Subglacial Basin Ice Sheet, East Antarctica
The Wilkes Subglacial Basin (WSB), a marine-based sector of the EastAntarctic Ice Sheet, contains enough ice to increase the global-mean sealevel by 3–4 m. The geometry of the WSB makes its ice sheet potentiallyvulnerable to unstable retreat, which could lead to rapidly increasingsea levels as well as meltwater production that could potentially disruptocean circulation, carbon cycling and marine ecosystems. This Reviewexplores the climate vulnerability of the WSB in the context of futureglobal warming. Paleo marine-sedimentary and model evidence suggeststhat substantial WSB ice-sheet retreat occurred during Pliocene andother past warm periods, albeit with uncertain temperature thresholds.Observations show unattributed multidecadal retreat of the groundingline and thinning and collapse of key fringing ice shelves but withoutclear upstream surface lowering. Projections of ice-sheet extent underfuture emissions scenarios indicate rapid retreat (up to ~1 km yr−1) beyondbedrock pinning points, but with uncertain timings and the possibilityof commitment to multimillennial change during this century. Giventhe potentially severe consequences of WSB ice-sheet change, amultinational and multiyear fieldwork and modelling programme isessential to reduce projection uncertainty.
(Nature Reviews Earth & Environment, 30/09/2026)
IGE, IRD, INSU - CNRS, CNRS, INRAE, Fédération OSUG, UGA, Grenoble INP, UGA, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EPHE, PSL
Process‐Based Modeling of Coastal Dune Blowout Initiation, Development, and Stabilization
Coastal dune blowouts are key geomorphic features that drive landward sediment transport, dune mobility, and habitat diversity, yet their conditions of formation and evolution remain poorly quantified. Using the process‐based AeoLiS model under time‐invariant wind conditions and for idealized coastal dune settings, we simulate the spontaneous development, growth, and stabilization of blowouts or blowout‐like landforms from initially alongshore‐uniform dunes. The model couples wind‐driven sediment transport, evolving topography, and vegetation dynamics, including germination, lateral expansion, and vertical growth. Our simulations show that small initial perturbations in vegetation cover, rather than topography, trigger blowout formation. Blowouts emerge as deflation basins at the dune crest, where low vegetation amplifies erosion and sediment fluxes, forming depositional lobes downwind. As a new incipient foredune forms seaward, aeolian activity declines and vegetation re‐establishes in the deflation basin, stabilizing the blowout system. Sensitivity analyses reveal that blowout development is favored on steeper dunes under stronger winds, with sparse or patchy vegetation and low‐lying hinterlands. Vertical vegetation growth governs the stabilization phase, while germination and lateral expansion introduce stochastic variability in blowout patterns. Slightly oblique onshore winds enhance alongshore variability and landward migration, whereas low wind speeds or dense initial vegetation suppress blowout formation. These results demonstrate that coastal blowouts are ecomorphodynamic instabilities arising from tightly coupled interactions between sediment, vegetation, and the evolving topography. The findings provide a framework for predicting blowout formation under varying environmental conditions and offer guidance for dynamic dune management strategies that enhance dune mobility and habitat heterogeneity.
(Journal of Geophysical Research: Earth Surface. vol. 131, n° 2169-9003, 01/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, TU Delft, BRGM, SCU
Positive fire-vegetation feedbacks modulated by hydroclimate changes in eastern tropical South America over the last 72 ka
The São Francisco basin (SFB) is the largest watershed in eastern tropical South America, encompassing vast areas of savannas, xeric vegetation, and tropical forests. Fire is a fundamental driver shaping ecosystems, yet long-term fire-vegetation dynamics under varying climate conditions in tropical South America remain poorly constrained. Here, we reconstruct 72,000 years of fire and vegetation history in the SFB based on microcharcoal and pollen analyses. Microcharcoal was identified and quantified using an approach combining chemical treatment, Raman spectroscopy for dark-particle identification, slide-scanning, and image analysis. A subset of samples was additionally analyzed for pollen to provide a long-term perspective on vegetation change. Our results show that fire activity was linked to the expansion or contraction of open savannas, which were both modulated by hydroclimate changes driven by orbital- and millennial-scale variability. Observed fire responses in the marine record were driven primarily by fire activity in the central regions of the SFB, which encompass the main burned areas associated with savannas. Modern analyses of the SFB support this interpretation, showing that savannas between 10 and 15°S experience fire activity more than ten times higher than that of adjacent SFB dry or humid forest areas. The most intense fire regime, between 32 and 22 ka, coincided with the maximum expansion of C4-dominated grasslands likely due to enhanced precipitation seasonality associated with a low obliquity phase. At millennial timescales, increased precipitation during Heinrich stadials generally suppressed fire activity through enhanced fuel moisture. Most intervals of increased moisture availability and reduced seasonality were associated with weakened fire regimes, pointing to a predominant fuel-moisture limitation in the basin. These findings also indicate that fire activity across the SFB positively responded to grassland expansion over the analyzed period and highlight the strong sensitivity of fire-vegetation feedbacks to hydroclimate variability across distinct timescales.
(Global and Planetary Change, n° 0921-8181, pp. 105715, 01/09/2026)
USP, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR ISEM, Cirad, IRD, EPHE, PSL, CNRS, UM, PACEA, UB, CNRS, UNIFESP
Estimating plastic export from estuaries into the sea using an estuarine-mass-balance model
Estuaries act as an interface between rivers and the sea, and therefore play a key role in transporting plastic to the sea. However, plastic transport in estuaries is complex and estuary-to-sea export is still very uncertain. This study presents a macroplastic mass-balance model that can be applied to specific estuaries, and produces export estimates similar to previous studies. The daily plastic export from estuary to sea during the wet season was estimated to be 290 kg for the Rhine-Meuse Estuary (RME), and 19,431 kg for the Saigon Estuary, where the discharge into the sea is 3.5 times larger for the RME, compared to the Saigon Estuary. Due to limited river discharge measurements for the Saigon Estuary, a yearly simulation could only be performed for the RME, corresponding to an export of 13,300 kg. These estimates fall within the uncertainty range of previous studies. Deposition and remobilization from riverbanks resulted in the largest model fluxes, with magnitudes of 20 t/d for the RME and 430 t/d for the Saigon Estuary. At the same time, the model is most sensitive to the uncertainty in parameters related to deposition. Our results demonstrate that with the right measurements, making reliable estimates of estuary-to-sea export is possible. However, uncertainty in plastic transport processes, like deposition and remobilization, leads to poorly constrained parameters and increased overall model uncertainty. Automated sensors, targeted field experiments, and improved model structure can enhance export estimates and further improve understanding of plastic dynamics in estuaries.
(Marine Pollution Bulletin. vol. 230, n° 0025-326X, pp. 119793, 01/09/2026)
WUR, IGE, IRD, INSU - CNRS, CNRS, INRAE, Fédération OSUG, UGA, Grenoble INP, UGA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Abundance and morphology of microscopic charcoal in modern marine sediments to refine the interpretation of paleofire records in the Western Mediterranean region
Paleofire records represent a valuable resource for understanding long-term changes in biomass burning and fire activity, as well as their drivers. Furthermore, they offer a way to assess fire models under climatic conditions that differ from those prevalent in the contemporary era. However, further calibration studies are needed to refine the link between paleofire records and more detailed characteristics of paleofire regimes. In order to enhance our understanding of the charcoal proxy, we analysed microscopic charcoal abundance and morphology in 277 marine surface sediment samples from the eastern Atlantic Ocean off the Iberian Peninsula and the western Mediterranean Sea, and investigated their link with fire regime characteristics, climate and fuel over adjacent land in the Western Mediterranean region. Our results show that squared microscopic charcoal particles are correlated with forest fires, while elongated microscopic charcoal particles are associated with the combustion of open and mixed vegetation, so that tree vs grass burning can be inferred by the relative changes in mean microscopic charcoal elongation ratios. Microscopic charcoal concentrations are a function of fuel type, climate, fire frequency and burned areas.
(Quaternary Science Advances. vol. 23, 01/09/2026)
GEO-OCEAN, UBS, IFREMER, INSU - CNRS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EPOC, CEFE, EPHE, PSL, CNRS, IRD [Occitanie], IRD, INRAE, Institut Agro, UM, UMPV, BRGM, CEFREM, UPVD, INSU - CNRS, CNRS
Diet modulates metabolic and hepatic responses to chronic pesticide mixture exposure in mice
Chronic exposure to pesticide mixtures through diet is common, yet their combined metabolic effects and interactions with dietary factors remain unclear. We identified four pesticides prevalent in human exposure (imazalil, thiabendazole, boscalid, lambda-cyhalothrin) and assessed their combined impacts on hepatic metabolism and metabolic homeostasis using human liver cells and male mice fed standard chow or western diets. We found that the pesticide mixture induced metabolic perturbations in human hepatocytes. In addition, the pesticide mixture altered hepatic gene expression in chow-fed mice and exacerbated western diet-induced glucose intolerance, fasting hyperglycemia, and insulin resistance without affecting body weight or liver steatosis. These findings reveal that dietary context influences the metabolic consequences of pesticide mixtures, highlighting the need to consider nutritional status when evaluating environmental contaminant risks. Our results suggest that pesticide mixtures at reference doses may contribute to metabolic dysregulation, particularly under obesogenic dietary conditions.
(Archives of Toxicology, n° 0340-5761, pp. Online ahead of print, 01/09/2026)
ToxAlim, ENVT, Toulouse INP, Comue de Toulouse, Toulouse INP, Comue de Toulouse, INRAE, EPE UT, Comue de Toulouse, EI Purpan, Comue de Toulouse, CRCT, INSERM, CNRS, EPE UT, Comue de Toulouse, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, E20, GENOTOUL, ENVT, INSERM, CNRS, Toulouse INP, INRAE, EPE UT, ToxAlim, ENVT, Toulouse INP, Toulouse INP, Comue de Toulouse, INRAE, EPE UT, Comue de Toulouse, EI Purpan, Comue de Toulouse, IGF, INSERM, CNRS, UM, UPS/Inserm U1297 - I2MC, INSERM, EPE UT, Comue de Toulouse, EpiAgeing [CRESS - U1153 / UMR_A 1125], CRESS (U1153 / UMR_A 1125), INSERM, UPCité, INRAE
Timeline of sex differentiation and stabilization in zebrafish: Interplay between methyl-sensitive transcription factors, prostaglandin-related genes and DNA methylation
The processes by which an individual develops as a male (testis) or female (ovary) are remarkably diverse across taxa. While sex is determined by genetic factors in some species, it can be determined by environmental factors in others. Despite these discrepancies, common features are however observed. For species as distant as drosophila and humans, the ovary or testis arises from a bipotential gonad. Thus, each embryo has the potential to develop as a male or female. Given the growing evidence that global change can affect the sexual fate and fertility of individuals across taxa, there is a critical need to understand the mechanisms involved in sex differentiation and maintenance. In the present work, we followed the transcription and methylation levels of genes known, or suspected, to be involved in sex differentiation throughout zebrafish development. Early sex differentiation was marked by sex-specific transcription patterns of genes encoding for methyl-sensitive transcription factors of the zbtb family and for sox9a and zar1, establishing common features with mammals. In contrast, our results suggest that sex markers such as cyp19a1a, dmrt1, foxl2a or amh are mainly involved in sex stabilization and maintenance. DNA methylation appeared to be at the interface, playing a role in sex differentiation and maintenance by progressively constraining plasticity and stabilizing the transcription of genes under study. Our results also highlighted significant changes in the transcription level of genes involved in prostaglandins production during the ovary-to-testis transition, suggesting a potential role of these mediators in DNA methylation reprogramming and sex differentiation.
(European Journal of Cell Biology. vol. 105, n° 0171-9335, pp. 151569, 30/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Measuring Ocean Surface Waves
Propagating waves on the ocean surface can be represented as a stochastic process whose statistics are characterized by a spectrum. This paper reviews methods for measuring the wave spectrum and related quantities. Observations begin by sensing fluid dynamical properties of the sea surface over space and/or time. Visual observations, collected routinely since the mid‐18th century, comprise the longest‐running wave record. Nearshore measurement methods continue to advance, including traditional pressure and acoustic sensing as well as newer technologies like distributed acoustic sensing and LiDAR. Detailed small‐scale wave physics can now be explored with measurement techniques using light, including stereo‐imaging and polarimetry. Reductions in the size, cost, and power consumption of microelectronics have propagated through ocean wave instrumentation, most notably in wave buoys. Global networks of freely drifting miniature wave buoys offer novel observational capabilities. Remote sensing techniques based on radar and LiDAR continue to evolve and are widely deployed from land, ships, aircraft, autonomous vehicles, and satellites. Spaceborne altimeters form one of the most important records of wave height, and new spaceborne sensors now observe directional spectra globally with sampling akin to traditional altimetry. Aircraft and autonomous systems provide strategic sampling capabilities for detailed process studies and access to extreme storm environments. The quality and quantity of ocean wave measurements have never been greater. This review aims to help make sense of it all.
(Reviews of Geophysics. vol. 64, n° 8755-1209, 13/08/2026)
USACE, UPR-M, UC San Diego, UC, ISMAR-CNR, ISMAR, CNR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, MET, UiB, UiO, SIO - UC San Diego, UC San Diego, UC, UVIC, OSU, SIO, RAS, TAU, LATMOS, UVSQ, INSU - CNRS, SU, CNRS, NTU, UNH, LIENSs, INSU - CNRS, ULR, CNRS, UTokyo | GSFS, UTokyo, DGFI-TUM, TUM, RU, Rutgers, DSTG, WHOI, APL-UW, KIOST, LDEO, PMEL, NOAA
Évolution des environnements sédimentaires au cours de la formation de la flèche du Cap Ferret : approche par géoradar et carottage
La flèche du Cap Ferret, située le long de la façade atlantique en Gironde, s’est formée au cours des 3 000 dernières années. Initialement ce littoral était caractérisé par la présence de l’embouchure tidal de la Leyre. La formation progressive de cette flèche du Cap Ferret et la migration de l’embouchure vers le sud, ont progressivement transformé ce littoral, passant d’un environnement ouvert à un environnement lagunaire semi-abrité. La chronologie et la dynamique sédimentaire associées à ces changements paléo- environnementaux restent cependant peu étudiées. Pour cela, un carottage de 15 m de profondeur couplé à un profil géoradar (antenne 100 MHz) ont été réalisés dans la partie nord de la flèche (Claouey, à proximité du VFF). Quatre unités morpho-sédimentaires distinctes sont identifiées. L'unité basale U1 (dont le toit atteint ~ -4.4 m NGF) correspond à un dépôt de sable gris coquillier (au moins 5.5 m d’épaisseur) caractéristique d’un remplissement de chenal. Drapant U1, U2 présente des sables moyens jaune et des réflecteurs radars fortement pentés (~15°), indiquant le sens de migration de barres intertidales et marquant le développement de la flèche et de sa base. U3 vient draper U2. C’est un niveau de sable jaune caractérisé par des réflecteurs radars subhorizontaux, interprété comme une accumulation de dépôts de sable marins puis éoliens. Ainsi, cette succession sédimentaire enregistre les principaux changements paléo-environnementaux, offrant une première caractérisation détaillée de l’évolution de la dynamique sédimentaire passée de ce littoral et la formation de la flèche du Cap Ferret.
(03/08/2026)
BRGM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS