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Merodon auriolus Vujić, Likov et Radenković in Vujić et al. 2025, une nouvelle espèce pour la faune de France (Diptera, Syrphidae)
No full textNational audienceMerodon auriolus Vujić, Likov & Radenković in Vujić et al., 2025 is reported from France for the first time on the basis of three specimens caught in April and May in Var and Bouches-du-Rhône departments. Its distinctive characteristics are described and illustrated.Merodon auriolus Vujić, Likov & Radenković in Vujić et al., 2025 est signalé en France pour la première fois sur la base de trois spécimens capturés en avril et mai dans le Var et les Bouches-du-Rhône. Ses caractères distinctifs sont rappelés et illustrés
Beyond single nanomaterial exposure: investigating the fate of a TiO 2 and CeO 2 nanomaterial mixture in freshwater mesocosms
No full textInternational audienceAssessing the environmental risks of emerging contaminants related to new technologies remains a major challenge due to the diversity of pollutants, their complex interactions, and the limitations of conventional testing frameworks. Among these contaminants, engineered nanomaterials (ENMs) stand out for their unique surface reactivities and transformation pathways, which can significantly alter their behavior and that of co-occurring pollutants. Although many studies have addressed the toxicity and fate of individual ENMs, real-world scenarios often involve complex mixtures, whose combined effects are less investigated. This study addresses this gap by investigating the fate, behavior, and ecological impacts of a mixture of two representative metal oxide ENMs i.e. an industrial TiO2 and a combustion-derived CeO2. This study shows that under environmentally relevant conditions using freshwater mesocosms, these two ENMs undergo primary hetero-aggregation. Co-exposure of the freshwater snail Planorbarius corneus revealed that ENM aggregates (homo- or primary hetero-aggregates) interact with egg layings, potentially affecting early developmental stages, while slight but measurable uptakes were also observed in co-exposed adult snails. Importantly, no quenching of reactive oxygen species generated by the photocatalytic TiO2 was detected in the presence of CeO2, suggesting that the combusted CeO2 does not mitigate potentially TiO2-induced phototoxicity. These findings underscore the importance of considering ENM mixtures in environmental risk assessments and the relevance of mesocosm experiments to capture realistic exposure scenarios. Future studies should prioritize investigating how unique surface reactivities and transformation mechanisms of ENM mixtures shape their ecological impacts throughout their life cycles
TRAJECTOIRE 4 A: Adapter - Anticiper - Articuler - Ajuster
No full textTrajectoire 4 A (T4A) is an action research project with two objectives: to help local authorities design their own climate change adaptation trajectory through actions carried out over different timeframes, and to guide them, using innovative reflection/decision-making tools, in reassessing their strategy and readjusting their environmental and territorial planning.T4A is built around geoprospective methods focused on modeling and simulations, with the aim of projecting land-use planning for the study area over the long term and encouraging local stakeholders to explore new ways of adapting to climate change that are suited to the diversity of their geographic context. The territory of the Pays de Grasse urban community (Alpes-Maritimes, France) serves as the testing ground for this approach.T4A offers an operational approach that can be replicated by any local government. The sequence of steps in the process provides a guiding framework for co-developing a climate adaptation policy tailored to the specific community, and for implementing it across the territory over the long term: assessing the expectations of local stakeholders, collectively identifying priority issues, gradually learning through prospective experiments using a serious game and a spatial simulation tool, conducting ex ante impact assessments of adaptation actions, engaging in collective reflection on the adaptation pathway based on the impacts of simulated actions, and making necessary adjustments to environmental and land-use planning.T4A has developed a spatial simulation tool called SIMPROSPECT (SIMulations PROSPEctives Ciblées sur la Transition), designed as a platform for reflection and decision support for local governors and public agents who want to learn how to develop and implement a transition pathway in their municipality. SIMPROSPECT is freely accessible on the project’s website (trajectoire4a.org) and it consists of two applications: SIMPROSPECT 1 is focused on testing policy levers that support sustainable mobility, while SIMPROSPECT 2 aims to reduce territorial vulnerabilities to future climate-related risks by enhancing adaptive capacity. Four risk-related themes are addressed: excess mortality among people over 80 during heatwaves, wildfires, flooding from stormwater runoff and mudslides, and water shortagesTrajectoire 4 A (T4A) est une recherche-action qui a une double finalité : aider une collectivité territoriale à concevoir sa propre trajectoire d’adaptation au changement climatique par des actions menées à différentes temporalités, et la guider, par des outils d’aide à la réflexion/décision novateurs, à réévaluer sa stratégie et à réajuster sa planification environnementale et territoriale.T4A est construit autour de méthodes de géoprospective axées sur la modélisation et les simulations, visant à projeter l’aménagement du territoire d’étude sur le temps long et à susciter chez les acteurs locaux de nouvelles réflexions sur les formes d’adaptation au changement climatique appropriées à la diversité de leur contexte géographique. Le territoire de la Communauté d’Agglomération du Pays de Grasse (Alpes-Maritimes, France) constitue le laboratoire d’expérimentation de cette démarche.T4A propose un mode opératoire reproductible à toute collectivité. Le chaînage des différentes phases de la démarche fournit un fil conducteur qui permet de co-construire une politique d’adaptation spécifique à la collectivité puis de l’opérationnaliser sur son territoire et sur le temps long : diagnostic des attentes des acteurs locaux, définition collective des problématiques prioritaires, apprentissage pas à pas des expérimentations prospectives à l’aide d’un jeu-sérieux et d’un outil de simulations spatiales, mesures ex ante des impacts d’actions d’adaptation, réflexion collective sur la trajectoire d’adaptation qui découle des impacts des actions simulées, réajustements de la planification environnementale et territoriale.T4A a créé un outil de simulation spatiale : SIMPROSPECT (SIMulations PROSPEctives Ciblées sur la Transition), conçu pour être un outil de réflexion et d’aide à la décision dédié aux élus et agents souhaitant apprendre à élaborer une trajectoire de transition et à l’opérationnaliser sur leur commune. SIMPROSPECT est en libre accès sur le site internet du projet (trajectoire4a.org) et il se compose de deux applications : SIMPROSPECT 1 vise à tester des leviers d’actions en faveur de la mobilité durable et SIMPROSPECT 2 a pour objectif de réduire les vulnérabilités du territoire face aux risques futurs liés aux changements climatiques en augmentant sa capacité d’adaptation. Quatre thématiques de risque sont considérées : la surmortalité des personnes de plus de 80 ans liée aux vagues de canicule, les incendies, l’inondation par ruissellement pluvial et les coulées de boue, et la pénurie d’eau
A method to estimate absolute odorant concentration of olfactory stimuli
No full textInternational audienceThe accurate quantification and delivery of odorant concentrations remain a significant challenge. Traditional methods estimate stimulus intensity based on the amount of odorant in the source, but this does not reflect the actual concentration sent due to variable evaporation rates and delivery devices. This leads to inconsistencies in stimulus delivery, complicating cross-laboratory comparisons, threshold evaluations, and the replication of natural olfactory conditions in the lab. To address this, we present a model based on mass transfer theory to predict the concentration of odorants delivered by a simple and versatile odor delivery system commonly used in insect electrophysiological experiments. The present model, built with adaptable compartments, accounts for airflow, source size, and the physicochemical properties of odorants. It helps to better design and use odor delivery systems, especially for stimuli required to mimic natural odor environments. Calibration uses known partition coefficients. The model also considers the dynamic shape of odor stimuli, which affects neuronal responses and must be carefully interpreted, especially when using tools like photoionisation detectors (PID). This approach was applied to study the impact of a plant volatile known to activate pheromone-sensitive neurons, (Z)-3-hexenyl acetate, on pheromone detection in Agrotis ipsilon moths. While interference occurs in laboratory conditions at 160 ppb, such concentrations are unlikely in natural settings, suggesting these effects are less relevant ecologically
How to integrate biology, physics and chemistry for a better description of soil water dynamics?
No full textInternational audienceNumerous and diverse edaphic organisms have the capacity to modify several physical and chemical soil characteristics that influence water transfers. Considering these modifications in modeling approaches would make for more accurate descriptions and modeling of water fluxes in soils. Some impacts of biological activity on soil physical aspects (e.g. modification of the pore space) have been described for 5-10 years now, and are being increasingly accounted for in water transfer models.However, the situation is not the same for biologically-driven chemical modifications linked to the secretion of organic molecules by soil organisms: modeling their consequences on pore space chemical properties and water transfers has just started. We here shortly survey prominent effects of biological activity on water-transfer related soil properties, and describe their coupling with existing water transfer models. We then propose possible ways for a better integration of biological soil modifications into such models. Among these, we point out that an energy-based theoretical framework would not only be consistent with the basic principles of thermodynamics, but would also foster synergies between ecologists, physicists and chemists, to better describe and predict water dynamics in soils and interactions with the soil biota. This would pave the way to model the evolution, on the scale of a few decades, of the water flow regulation services provided by soils</p
Multiple sclerosis, fertility, pregnancy, and assisted reproductive technology: Current knowledge
No full textInternational audienc
Flash vacuum expansion technology for small-scale production of fruit puree: development and quality assessment
No full textInternational audienceFruit processing at small scale often lacks access to efficient, integrated technologies capable of ensuring product quality and safety. Flash Vacuum Expansion emerges as a promising alternative to conventional thermal treatments by coupling rapid steam heating with instant decompression, enabling simultaneous pasteurization and cooling, tissue disintegration, and deaeration. This study presents the design, construction, and validation of an optimized Flash Vacuum Expansion prototype tailored for small- and medium-scale agroindustries. The system integrates six unit operations—blanching, pasteurization, mashing, cooling, deaeration, and pulping—of which the last four are conducted under vacuum conditions. Heating is achieved through a screw conveyor blancher equipped with direct steam injection, while the vacuum operations are synchronized using double-valve airlocks. Performance was assessed using açai and Andean blackberry, evaluating microbial inactivation, physicochemical and rheological properties, and energy efficiency. FVE-treated purees showed complete microbial inactivation (<10 CFU/g), significant increases in pulp yield and extraction efficiency, reduced insoluble solids, enhanced pigment release, and superior rheological consistency. Energy consumption analysis revealed specific energy consumption (SEC) values as low as 0.97 MJ/kg—markedly lower than conventional processing benchmarks. The proposed FVE system represents a scalable and energy-efficient solution for producing high-quality fruit purees
Stimulation de la voie des phénylpropanoïdes par application de phénylalanine chez la fraise et la tomate pour le contrôle de Botrytis cinerea
No full textInternational audienceLa fraise (Fragaria × ananassa) et la tomate (Solanum lycopersicum) sont deux cultures économiquement importantes sensibles au champignon Botrytis cinerea, responsable de la pourriture grise au champ et sur les fruits lors du stockage post-récolte. Face aux enjeux environnementaux et sanitaires liés à l’usage des fongicides de synthèse, stimuler les défenses des plantes via la voie des phénylpropanoïdes apparaît comme une alternative prometteuse (Ramaroson et al., 2022). Cette voie métabolique débute par la conversion de la phénylalanine (Phe) en acide trans-cinnamique via l’enzyme phénylalanine ammonia-lyase (PAL). Les composés phénoliques produits, notamment les flavonoïdes, stilbènes ou acides phénoliques, contribuent à la résistance aux pathogènes via des fonctions antioxydantes, structurelles et de signalisation (Saini et al., 2024). Des travaux récents montrent que l’application exogène de Phe peut induire une résistance accrue des plantes à des infections fongiques. L’application préventive d’une solution de 4,1 mM de Phe confère une résistance à B. cinerea sur feuilles détachées de tomate (Oliva et al., 2020). Sur fraise, des pulvérisations de 10 mM en pré- ou post-récolte diminuent la sensibilité des fruits sans affecter leur qualité (Pons et al., 2025). L’effet de la Phe semble indirect, via l’induction de métabolites de défense par la plante (Oliva et al., 2020), et son efficacité accrue proche de la récolte pourrait s’expliquer par une métabolisation rapide de la Phe en composés actifs (Kumar Patel et al., 2020). L’étude vise à (1) explorer l’effet de différents paramètres sur l’efficacité de la protection induite par la pulvérisation de Phe contre B. cinerea (dose, moment d’application, génotype de la plante, souches de l’agent pathogène) sur fraise et tomate, (2) développer une compréhension fine de la métabolisation de la Phe dans ces conditions, et (3) évaluer l’impact de ce traitement sur la qualité et la conservation des fruits
Biopesticide Production from Trichoderma harzianum by Solid-State Fermentation: Impact of Drying Process on Spore Viability
No full textInternational audienceAmong the sustainable agricultural approaches, biological control agents are a promising new alternative to agrochemicals. However, expensive production methods, formulation, poor storage stability and short shelf life are limiting their adoption. One of the promising options for biopesticide production is solid-state fermentation (SSF). This study was conducted to evaluate spore production by two Trichoderma harzianum, Rey 3 and TF2, under forced air drying in SSF. A mixture of agroindustrial byproducts (sugarcane bagasse, vine shoots, wheat bran, potato flour and chitin) were used as substrates. CO 2 generated during fungi growth was recorded by respirometry. We also investigated the effect of hydric stress conditions on the decreasing phase of Trichoderma metabolism as an inducer of sporulation. In parallel, we analyzed the viability of T. harzianum TF2 and spores under different storage conditions (lyophilized, frozen and dried). Under the present culture conditions, the highest production of spores was 10.1 ± 0.3 × 10 9 spores/g DM (Dry Material) at 52 h for T. harzianum Rey 3 and 8.9 ± 0.6 × 10 9 spores/g DM at 72 h for T. harzianum TF2. The forced dry air during the fermentation process had no notable effect on spore production, but it did increase the spore viability (29% viability for T. harzianum Rey 3 and 33% viability for T. harzianum TF2). In parallel, the chitinase, cellulase, xylanase and lipase activities were evaluated, obtaining interesting results regarding enzymatic activities.</div
Contrasting emissions of biogenic volatile organic compounds from soil in a Mediterranean evergreen forest under natural and amplified long-term rain scarcity
No full textInternational audienceBackground and aimsBiogenic volatile organic compounds (BVOCs) play numerous ecological functions as they account for organism defenses and are drivers of organic matter decomposition, organism development and trophic interactions. BVOCs also act as precursors of secondary organic pollutants. Thus, studying their variability according to climate change is of crucial importance. This research aimed to assess the variability of BVOC emissions from natural forest soil under both natural drought (ND) and amplified drought (AD, ~ 30% rainfall exclusion over 9 years), as projected for the Mediterranean region by the end of the century.MethodsThe experiment took place in a representative and homogenous Mediterranean mixed forest (Pinus halepensis Mill. and Quercus ilex L.) using five different soil surfaces covered by litter under ND and AD conditions in July 2018. BVOCs were collected using a push–pull system, trapped within adsorbent cartridges and analyzed (quantitatively and qualitatively) by GC–MS.ResultsForest soil emissions released 184 µgC m−2 h−1 under ND but diminished by 84% under AD. Most monoterpenoids and oxygenated compounds were correlated with P. halepensis litter dry mass. Interestingly, sesquiterpenoids were positively corelated to Q. ilex litter while this litter does not possess terpene storage structures.ConclusionsThe future limited precipitation in the Mediterranean basin will result in the decline of forest soil BVOCs certainly implying a loss of both forest functionality and interaction with the atmosphere.Although litter biomass appeared as a driver of forest soil BVOCs, microorganisms and roots need to be further characterized to better understand their contribution to BVOC fluxes in natural forest soi