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Legacy and emerging per- and polyfluoroalkyl substances in eggs of yellow-legged gulls from Southern France
No full textInternational audienceMore than 70 years of industrial production of per-and polyfluoroalkyl substances (PFAS) have resulted in their ubiquitous presence in the environment on a global scale, although differences in sources, transport and fate lead to variability of occurrence in the environment. Gull eggs are excellent bioindicators of environmental pollution, especially for persistent organic pollutants such as PFAS, known to bioaccumulate in organisms and to be deposited in bird eggs by maternal transfer. Using yellow-legged gull (Larus michahellis) eggs, we investigated the occurrence of more than 30 PFAS, including the most common chemicals (i.e., legacy PFAS) as well as their alternatives (i.e., emerging PFAS) in the Bay of Marseille, the second largest city in France. Compared to eggs from other colonies along the Mediterranean coast, those from Marseille had PFAS concentrations ranging from slightly higher to up to four times lower, suggesting that this area cannot be specifically identified as a hotspot for these compounds. We also found several emerging PFAS including 8:2 and 10:2 FTS, 7:3 FTCA or PFECHS in all collected eggs. Although the scarcity in toxicity thresholds for seabirds, especially during embryogenesis, does not enable any precise statement about the risks faced by this population, this study contributes to the effort in documenting legacy PFAS contamination on Mediterranean coasts while providing valuable novel inputs on PFAS of emerging concern. Identifying exposure in free-ranging species also participate to determine the main target for toxicity testing in wildlife
Green synthesis of antimicrobial nanotechnology using flavonoids: a systematic review
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Mercury contamination in the European green toad Bufotes viridis in Vienna, Austria.
No full textInternational audienceMercury (Hg) contamination affects all ecosystems worldwide. Its deleterious effects on wildlife and humans encompass a diversity of impacts from individual to population levels. In the present study, we quantified Hg concentration across various tissues (blood, brain, muscle, and toe) of green toads (Bufotes viridis) and investigated the use of toe clips as a proxy of Hg concentration in internal tissues, including the brain. Our results show distinct patterns of Hg contamination across tissues, with the highest Hg concentration in the blood with 1.496 ± 0.772 µg.g−1 dry weight (dw), followed by muscle tissue with 0.687 ± 0.376 µg.g−1 dw, brain tissue with 0.542 ± 0.319 µg.g−1 dw, and toes with 0.229 ± 0.143 µg.g−1 dw. A strong relationship has been found between toe and brain Hg concentrations (R2 = 0.857, p < 0.001). These results emphasize the potential of toe clipping as a reliable, non-lethal method for predicting brain Hg concentrations in the green toad. Further, results open the possibility of assessing the potential association between Hg contamination and the cognitive performance of amphibians
A practical framework to evaluate the feasibility of incentive-based approaches to reduce bycatch of marine mammals and other protected species
No full textInternational audienceFisheries bycatch is one of the biggest threats to marine mammal populations and an important conservation and management problem worldwide. Conventional marine mammal bycatch mitigation approaches typically rely on top-down, command-and-control regulations that often fail to create desired incentives for fishers to avoid bycatch. There is growing recognition of the need to explore alternative approaches that encourage behavioral change through the creation of an appropriate set of incentivesboth economic and socialtowards bycatch reduction. This study introduces a practical framework that aims to evaluate a range of dimensions related to the feasibility and durability of incentive-based approaches to mitigate marine mammal bycatch. We use this framework to examine seven case studies where incentive-based measures have been implemented or proposed, demonstrating both its applicability in a variety of contexts and usefulness in ex-ante assessment of alternative bycatch mitigation options. Our analysis underscores important operational aspects to consider in implementing such approaches, including the need for fine-scale data collection, the importance of a credible threat such as a fishery closure or loss of market access, the involvement of fishers in solution development, and the pivotal role of collective organizations in addressing marine mammal bycatch issues which almost always are complex and multi-faceted
Acclimation and recovery dynamics of behavioral and coloration responses of a common fish (Squalius cephalus) to paracetamol exposure
No full textInternational audienceFreshwater ecosystems are increasingly exposed to pharmaceutical contamination, impacting non-target species. Concentrations can vary over time and location, allowing for potential acclimation or recovery effects. Additionally, parasites might interfere with the absorption and adverse outcomes pathways of pollutants. We examined the combined effects of paracetamol and parasite on the behavior and coloration of the European chub (Squalius cephalus), a ubiquitous fish species, from natural populations. Fish were exposed in mesocosms to acute doses of paracetamol (16 μg g−1 once a day over two days), followed by lower doses during a long-term exposure (1.6 μg g−1 once a week over three weeks), followed by a three-week recovery phase. Acute exposure induced marginal decreases in behavioral activity, and changes in dorsal brightness, hue and UV luminance. Interestingly, the long-term phase alone did not yield notable results on behavior and coloration. However, some effects of the acute exposure persisted during the long-term phase, highlighting that the expression of biological responses may be delayed in relation to past high exposure. Parasitism did not attenuate acute impacts, suggesting parasites may not help mitigate effects of paracetamol on behavior and coloration, but alone increased activity levels slightly. No effects of pollutant exposure, either of the acute or long-term phase, were observed after a recovery phase, indicating ability for recovery dynamics. Overall, our findings emphasize that pollutants effects can be highly transient, with rapid recovery when pollutant exposure ceased. Considering different exposure phases is crucial when assessing the ecological consequences of environmental contaminants
Mercury trophic transfer and biomagnification in food webs within a tropical embayment as evidenced by nitrogen and carbon stable isotope analysis
No full textInternational audienceMercury (Hg) contamination in marine ecosystems poses a significant environmental threat due to its high toxicity, persistence in the environment, and tendency to bioaccumulate in organisms and biomagnify in food webs. Understanding how Hg moves through these food webs is essential for assessing its ecological and health impacts. To investigate the trophic dynamics of Hg in Rayong Bay, Gulf of Thailand, we collected marine organisms from the pelagic and benthic food webs during 2022–2023 and analyzed the total mercury content (THg) in plankton (phytoplankton, zooplankton, and fish larvae) and in 81 marine animal species. Furthermore, the stable nitrogen and carbon isotope values (δ15N and δ13C) were measured to establish their trophic levels (TLs) and potential food sources in the food web. Based on these analyses, we calculated the biomagnification factor using TL-adjusted ratios (BMFnorm) and trophic magnification factor (TMF) for the different TLs. BMFnorm values exceeded 1.0 in over 40 % of cases for both the pelagic and benthic food webs, indicating THg biomagnification from prey to predator. Notably, the pelagic food web exhibited a markedly higher TMF value (TMF = 6.68) compared to that of the benthic food web (TMF = 2.06), suggesting stronger Hg biomagnification within the pelagic food web. Our findings also highlight the consumption risk of Hg in some fish species in the Rayong Bay food webs, emphasizing the need for continued monitoring and mitigation strategies to safeguard both human and ecological health
Apprentissage automatique pour la prédiction de la résistance à la compression de bétons à base de poudre de verre recyclé
No full textInternational audienceL’industrie cimentière est une source majeure d’émissions de CO₂, ce qui motive la recherche d’alternatives visant à limiter son impact environnemental. L’incorporation de poudre de verre recyclé (PVR) comme substitut partiel du ciment est une solution étudiée pour réduire ces émissions et valoriser les déchets de verre. Cette étude porte sur la prédiction de la résistance à la compression de bétons contenant de la PVR à l’aide d’un réseau de neurones artificiels de type Multilayer Perceptron (MLP). Le modèle développé analyse la relation entre la composition du béton (teneur en PVR ainsi que rapports Eau/Liant et Eau/Ciment) et sa résistance à la compression. L’évaluation du modèle s’appuie sur une base de données expérimentale et utilise des métriques telles que l’erreur quadratique moyenne et l’erreur absolue. Les résultats montrent que cette méthode d’intelligence artificielle permet de prédire la résistance à la compression avec une précision satisfaisante, bien que des écarts soient observés à certaines teneurs en PVR. Cette approche permettrait d’optimiser la formulation des bétons tout en réduisant le recours aux essais expérimentaux. Des travaux futurs viseront à intégrer d’autres paramètres, telle que la granulométrie de la PVR, et à faire varier la formulation du béton, afin d’améliorer la fiabilité des prédictions
Experimental evidence that soil fauna drives plant root exudation patterns
No full textInternational audienceSoil fauna is an essential component of soil. However, its influences on root exudates are unknown. Through both direct and indirect interactions, soil fauna can affect the dynamics of interactions between plants, microbes, and soil environments. In this study, we used an original approach called EcoRoots, which features rhizoboxes with sorption traps and allows exudates on roots to be sampled with minimum soil and plant disturbance. We designed an experiment to determine the effect of springtails (Folsomia candida W.), earthworms (Lumbricus terrestris L.), or both on plant root metabolites of Poa annua L., a gramineous species. After nine weeks of experiments, soil fauna increased the nutrients in soil, but P. annua growth was reduced mainly in the presence of earthworms. With regard to P. annua exudation, we found specific assemblages depending on the fauna identity, with the interaction between springtails and earthworms bringing different exudates than the sum of the two single treatments. Plants in presence of soil faunal groups produced a higher richness of exudate metabolite than without soil fauna. We also found that earthworms had the greatest influence on metabolite patterns. The changes in root exudation were associated with differences in abiotic factors and microorganism communities, suggesting that both direct and indirect effects might explain these patterns. Nevertheless, distinguishing the mechanisms involved in the process remains complex. To conclude, we strongly recommend studying living soil or more real ecosystems to advance our understanding of root exudation and, more globally, soil interactions and ecology, whether in natural or agricultural ecosystems
Les ports de la Seine de la révolution industrielle à la mondialisation
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Scalable Framework for Classifying AI-Generated Content Across Modalities
No full textInternational audienceThe rapid growth of generative AI technologies has heightened the importance of effectively distinguishing between human and AI-generated content, as well as classifying outputs from diverse generative models. This paper presents a scalable framework that integrates perceptual hashing, similarity measurement, and pseudo-labeling to address these challenges. Our method enables the incorporation of new generative models without retraining, ensuring adaptability and robustness in dynamic scenarios. Comprehensive evaluations on the Defactify4 dataset demonstrate competitive performance in text and image classification tasks, achieving high accuracy across both distinguishing human and AI-generated content and classifying among generative methods. These results highlight the framework's potential for real-world applications as generative AI continues to evolve. Source codes are publicly available at https://github.com/ffyyytt/defactify4