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Seeing yew for the forest: a call to action for improving conservation and restoration of the European yew (Taxus baccata L.)
No full textInternational audienceThe European yew (Taxus baccata L.) is a long-lived conifer of ecological, cultural, and historical importance across Eurasia. Despite its remarkable resilience, wide distribution, and symbolic importance, the species has experienced a long-term decline due to a complex interplay of climatic fluctuations, megafaunal extinctions, human exploitation, and insufficient regeneration. Recent studies in palaeoecology, archaeology, dendroecology, and conservation have revealed a species with greater ecological plasticity and a broader historical distribution than previously assumed. However, many fundamental questions remain unresolved, particularly regarding its biogeographical history, population dynamics, recruitment processes, and the drivers of its decline.This review stems from prior investigations of yew in the French Pyrenees and, more broadly, across Europe. These efforts led to a transdisciplinary seminar and opened a collaboration uniting >30 researchers across Eurasia. By synthesizing a wide array of data and perspectives, the article highlights key knowledge gaps and outlines emerging research priorities. These are organized thematically—past, present, and future—and include 25 questions on the species' ecological niche, life-history strategies, human interactions, genetic resilience, and conservation under global change. The article advocates for a shift towards integrative and long-term conservation strategies that embrace the historical legacies of yew populations, the general ecology of the species along with local ecological context dependence, and the urgency of future threats. By identifying pressing research needs, this review seeks to lay the foundation for new collaborative initiatives and to support evidence-based conservation of this emblematic yet understudied species
First evidence of deleterious effect of pesticide mixture on health status in semi-captive grey partridges
No full textInternational audiencePesticides are mainly used in agroecosystems to control pests. Due to their limited specificity, the resulting widespread contamination may cause unintended effects on non-target organisms that use these habitats. While increasing attention is paid to the relationship between single substances and phenotype on non-target species, their combined impacts are still largely unknown. Since interactions between pesticides may also impact organisms' health, studying them as complex mixtures is the more realistic approach. Here, we present the first experimental study testing the relationship between an environmentally relevant pesticide mixture and health biomarkers on a farmland avian non-target model. To do so, we used 40 semi-captive grey partridges (Perdix perdix) fed for five months with conventional grains. Their plant protection product (PPP) load (i.e., the number of PPPs, the total sum of scaled pesticide concentrations and the total toxicity index) in blood and proxies of health status (evaluated using behavioral and physiological features) were monitored at the end of the exposure period. We demonstrated, for the first time, concerning correlations between PPP load indexes and bird healthrelated features (physical activity, flight initiation distance, eye ring redness and acetylcholinesterase activity). Overall, we highlighted the urgent need to consider environmentally-relevant PPP mixture when biomonitoring non-target vertebrates in ecotoxicological studies.</div
A narrative review of the impact of anthropogenic light and noise on owls
No full textInternational audienceToday, owls are exposed to increasingly brightly lit nights and noisy environments because of human activities. To understand the impacts of artificial light at night (ALAN) and anthropogenic noise we performed an evidence synthesis. We searched four literature databases and Google Scholar and we collected 39 relevant articles (1945-2024) providing 125 cases (64 on light pollution and 61 on noise pollution), targeting 25 species (c. 10% of owl species). We found harmful effects of both sensory pollutants on several outcomes. First, ALAN tends to reduce acoustic communication and to be associated with a lower occurrence of owl species, although it is difficult to confirm whether ALAN leads to silent or absent owls. Moreover, ALAN disturbs owl-prey interactions. Although light probably improves owl vision, the light-avoidance behaviour of small mammals could result in poorer hunting success of owls feeding on mammals. Conversely, ALAN enhances food provisioning and even breeding of owls feeding on insects that are attracted by light, to the detriment of these prey populations. Second, human-induced noise clearly tends to reduce owl vocalization, yet that vocalization may be essential to communication between individuals. The ability of owls to detect prey (hunting success) is also reduced under noise exposure (even at low amplitude), probably as the result of masking and distraction. Studies also demonstrate that anthropogenic noise can cause physiological and behavioural stress and disturbance to owls. Such adverse effects may contribute to declines in reproduction and occurrence of owls observed in noisy areas. As a result, we recommend reduction of both sensory stressors as much as possible, for owls and for ecosystem stability, for example by maintaining and restoring quiet and dark areas. We also recommend more consideration of owls in sensory ecology research to fill knowledge gaps.De nos jours, les rapaces nocturnes sont exposés à des nuits de plus en plus lumineuses et à un environnement de plus en plus bruyant en raison des activités humaines. Pour comprendre l'impact potentiel de la lumière artificielle nocturne et du bruit anthropique, nous avons réalisé une revue de littérature. Nous avons interrogé 4 bases de données bibliographiques et Google scholar et nous avons collecté 39 articles pertinents (1945–2024) fournissant respectivement 125 cas (64 sur la pollution lumineuse et 61 sur la pollution sonore), ciblant en tout 25 espèces (~10% des Strigiformes ). Nous avons trouvé plusieurs effets néfastes des pollutions lumineuse et sonore. Tout d'abord, la lumière artificielle tend à diminuer la communication acoustique et est associée à une occurrence plus faible, bien qu'il soit difficile de confirmer si les chouettes sont plus silencieuses ou absentes. Il est indéniable que l'éclairage nocturne perturbe les interactions entre les rapaces nocturnes et leurs proies, ce qui peut expliquer en partie cette situation pour les espèces qui se nourrissent de rongeurs, selon les effets documentés de la luminosité de la lune: alors que la lumière améliore la vision des chouettes/hiboux, le comportement d'évitement de la lumière des petits mammifères pourrait entraîner un moins bon succès de chasse. Inversement, l'éclairage artificiel améliore l'approvisionnement en nourriture et même la reproduction des chouettes insectivores, probablement au détriment des populations de proies attirées par la lumière. Deuxièmement, les sons artificiels tendent clairement à diminuer la vocalisation des chouettes, pourtant essentielle à la communication (par exemple entre partenaires). La capacité des Strigiformes à détecter leurs proies (succès de chasse) est également réduite en cas d'exposition au bruit (même à faible amplitude), sûrement par un effet de masquage et de distraction. Les données démontrent également que le bruit anthropique provoque du stress et des perturbations, tant au niveau physiologique que comportemental. Ces effets négatifs peuvent être responsables de la tendance à la baisse de la reproduction et de l'occurrence des rapaces nocturnes qui est également observée dans les zones bruyantes. Par conséquent, nous recommandons de réduire autant que possible les deux facteurs de stress sensoriel—pour les chouettes/hiboux et pour la stabilité des écosystèmes—par exemple en maintenant et en rétablissant des zones calmes et sombres. Nous demandons également que les Strigiformes soient davantage pris en compte dans la recherche en écologie sensorielle afin de combler les lacunes en matière de connaissances
Biomechanical mapping of porcine dentin and branches with Brillouin confocal VIPA-based microscopy
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Critical metals behavior in amphibolite facies: metamorphic conditions and ore mineral compositions Sulitjelma and Bleikvassli Pb-Zn-Cu mines, Norwegian Caledonides.
No full textInternational audienceAs part of the Critical Metals in Orogen project (https://anr-cmio.gm.umontpellier.fr/), this study focuses on the presence and potential remobilization of critical metals, especially Indium, at the historic Sulitjelma Cu-Zn and Bleikvassli Zn-Pb-Cu mines in the Norwegian Caledonides. The style of mineralization is considered VMS and SEDEX, respectively, but both localities have suffered metamorphism and deformation during the formation of the Caledonian orogen. Ore and host rocks samples of the Sulitjelma and Bleikvassli mines were studied in order to understand the link between metamorphism, mobility, and critical metal concentrations within the mineralizations. To address this issue, several methods were used: macroscopic and microscopic analyses, thermodynamic modelling, EBSD, LA-ICP-MS, LIBS and EPMA in situ analysis. The host rocks are mostly metasediments composed of quartz, micas, garnet, staurolite, kyanite and rare sillimanite. Using pressure-temperature diagrams calculated for the host rock, we obtain for Bleikvassli, temperature conditions between 650 and 750 °C and pressure conditions between 6.5 and 11 kbar. For Sulitjelma, the metamorphic conditions are slightly lower, with temperatures between 550 and 700 °C and pressures between 5 and 12 kbar. These data suggest that the host rocks of the Bleikvassli and Sulitjelma mineralizations experienced amphibolite facies conditions associated with Barrovian metamorphism in a collisional context, in agreement with the available literature. Ore samples are dominated by pyrite–chalcopyrite–sphalerite and pyrrhotite–chalcopyrite–sphalerite assemblages, with the local presence of magnetite. EBSD results show that, in most of the samples, pyrrhotite, pyrite and chalcopyrite show a preferential orientation possibly indicating dynamic recrystallization whereas, sphalerite, appearing texturally late might have crystallized under static conditions. EMPA and LA-ICPMS in situ analytical results on the mineralizations indicate the presence of significant iron in sphalerite in both deposits with 4.4 wt% at Bleikvassli and 5.7 wt% ppm at Sulitjelma. In addition, cadmium, manganese, and indium are preferentially incorporated into sphalerite as well. In both deposits, there is a significant amount of indium in sphalerite, up to 55 ppm. Gallium and germanium concentrations in sphalerite are low. Indium and manganese are also present in chalcopyrite but at lower concentrations. By contrast, tin and silver are preferentially incorporated into chalcopyrite. Cobalt, nickel, and arsenic are enriched in pyrite
Chemical hydrogen storage materials – boranes and silanes catalytic solvolysis and dehydrogenation: a mechanistic and regeneration perspective
No full textInternational audienceHydrogen (H 2 ) has gained a lot of interest as an alternative energy vector, to reduce greenhouse gas emission issues caused by the fossil fuel industry. However, to make hydrogen a real energy carrier in a decarbonated economy, a secure and sustainable supply chain is needed. This approach requires notably safe storage and efficient strategies for recycling of raw materials. We discuss in this survey the state-of-the-art in the field of chemical hydrogen storage (CHS) materials, considering two possible vectors: ammonia borane and hydrosilanes. Regardless of the vector, to achieve real use, it is necessary to understand both the performance of the system and its life cycle, which relates to catalysts structure, and the activation of chemical bonds with efficient and complete catalytic cycles. We give herein an overview of hydrolysis and/or alcoholysis from metals, using coordination complexes, molecular supported catalysts or other materials, including nanocatalysts, with a focus on mechanistic information and understanding. Notably, the studies related to these two vectors can be considered somewhat complementary. Thus, the set of bibliographic report on ammonia borane is very documented in efficient catalytic systems, while its recycling remains at a very early stage. In comparison, hydrosilanes have been much less addressed specifically as a vector for hydrogen, while their reactivity at the molecular scale benefits from a relevant understanding from coordination chemistry studies. In addition, both hydrosilane polymerization and solvolysis reaction enables the release of H 2 , and produces by-products of which added value is already established. This opening the way to economical strategies where recycling can be optional. Nevertheless, the reversibility of hydrosilanes chemistry in H 2 uptake remains attractive and is another option to develop
NVLIM: MTJ and CMOS-Based Nonvolatile Latch Design With Protection Against Triple-Node-Upsets for Robust Computing
No full textInternational audienceSoft errors and power dissipation emerge as critical challenges in developing high-reliability and cost-sensitive embedded systems. To address these issues, the magnetic tunnel junction (MTJ) is considered a promising solution due to its nonvolatility and its compatibility with traditional CMOS manufacturing processes. In this work, we propose a novel nonvolatile (NV) latch consisting of inverters and MTJs, namely, NVLIM, which provides nonvolatility and robust partial tolerance against triple-node-upsets (TNUs) at low cost. NVLIM integrates a TNU-tolerant block based on CMOS with a backup-restore block using MTJs. Simulation results incorporating process, voltage, and temperature (PVT) variations, bias temperature instability (BTI) impact, and Monte Carlo simulations demonstrate the balanced performance in terms of nonvolatility, robust partial TNU tolerance, and comprehensive overhead of the proposed latch
Bridging Econometrics and AI: VaR Estimation via Reinforcement Learning and GARCH Models
No full textInternational audienceEstimating market risk in volatile environments remains a major challenge, as traditional GARCH-type models often struggle to capture nonlinear dynamics. This paper proposes a hybrid Value-at-Risk (VaR) framework that integrates GARCH volatility forecasts with a Double Deep Q-Network (DDQN) reinforcement learning classifier. By reframing VaR estimation as a classification problem, the model adaptively adjusts risk thresholds based on predicted low- and high-risk return regimes. Using more than 16 years of Euro Stoxx 50 data, the framework achieves 79.4% test accuracy and substantially reduces both the frequency and the temporal clustering of VaR violations. Backtesting confirms compliance with the Kupiec and Christoffersen tests, while Extreme Value Theory supports its ability to model tail risk. The resulting approach offers a statistically robust, capital-efficient, and regulatory-aligned solution for proactive financial risk management
Target trial emulation to replicate randomised clinical trials using registry data in multiple sclerosis
No full textInternational audienceBackground: Target trial emulation (TTE) offers a formal framework for causal inference using observational data, but its validity must be evaluated in each research domain by replicating randomised clinical trials (RCTs). We aimed to replicate eight RCTs evaluating the efficacy of disease-modifying therapies (DMTs) in multiple sclerosis (MS) using French registry data.Methods: This multicentre, retrospective, observational study was conducted using data extracted in December 2023 from the Observatoire Français de la Sclérose en Plaques (OFSEP) database. For each emulated trial, patients were included when they initiated one of the DMT evaluated in the corresponding RCT and met its inclusion criteria. Clinical outcomes were the annualised relapse rate and 3-month confirmed Expanded Disability Status Scale progression. Radiological outcomes were new/enlarged T2-lesions and new gadolinium-enhanced T1-lesions on a brain MRI. A targeted maximum likelihood estimator was used to estimate the treatment effect adjusted for confounding factors between groups and corrected for censoring and missing outcome assessment.Results: 14 111 patients were included in eight emulated trials: ASSESS (fingolimod vs glatiramer acetate), BEYOND (interferon beta vs glatiramer acetate), CONFIRM (dimethyl fumarate (DMF) vs glatiramer acetate), OPERA (ocrelizumab vs interferon beta), REGARD (interferon beta vs glatiramer acetate), RIFUND-MS (rituximab vs DMF), TENERE (teriflunomide vs interferon beta) and TRANSFORMS (fingolimod vs interferon beta). Treatment effects estimated in emulated trials were concordant with RCT findings in seven of eight trials for relapse rate, and in all six trials assessing disability progression. Radiological outcomes were more challenging to replicate; concordance was achieved in three of five trials for new T2-lesions, and one of four trials for new gadolinium-enhanced T1-lesions.Conclusion: The combined use of a TTE methodology and high-quality registry data is a valid tool to evaluate treatment effectiveness in MS
Hecke cycles on moduli of vector bundles and orbital degeneracy loci
No full textInternational audienceGiven a smooth genus two curve C, the moduli space SU_C (3) of rank three semistable vector bundles on C with trivial determinant is a double cover in P^8 branched over a sextic hypersurface, whose projective dual is the famous Coble cubic, the unique cubic hypersurface that is singular along the Jacobian of C. In this paper we continue our exploration of the connections of such moduli spaces with the representation theory of GL_9, initiated in [GSW13] and pursued in [GS15, RS18, RS19, BMT21]. Starting from a general trivector v in ∧^3 C^9 , we construct a Fano manifold D_Z_10 (v) in G(3, 9) as a so-called orbital degeneracy locus, and we prove that it defines a family of Hecke lines in SU_C (3). We deduce that D_Z_10 (v) is isomorphic to the odd moduli space SU_C (3, O_C (c)) of rank three stable vector bundles on C with fixed effective determinant of degree one. We deduce that the intersection of D_Z_10 (v) with a general translate of G(3, 7) in G(3, 9) is a K3 surface of genus 19