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Pyrroline-5-carboxylate dehydrogenase is a key actor of nitrogen metabolism in maturing seeds of Arabidopsis thaliana: P5CDH and seed development
No full textInternational audienceProline is a multifaceted amino acid in plants involved in both stress responses and development. Recent studies have shown that knock-out mutants lacking Pyrroline-5-carboxylate dehydrogenase (P5CDH), the enzyme responsible for the second step of proline catabolism, impaired nitrogen remobilisation and carbon allocation to seeds. Here, we demonstrate that seed development is also significantly impaired in p5cdh mutants, particularly from the transition between embryogenesis and maturation. Specifically, the p5cdh mutation leads to an arrest in embryo elongation and a reprogramming of seed metabolism during maturation, resulting in reduced accumulation of storage compounds and compromised acquisition of dehydration tolerance. These effects are further exacerbated under high nitrate conditions. Together, our findings highlight a crucial role for proline catabolism in supporting the ability of maturing embryos to utilize glutamine as a nitrogen source, particularly in response to nitrogen availability
Abus de confiance : Des informations transmises dans le cadre d'un audit de pré-acquisition (due diligence)
No full textInternational audience(Crim. 25 juin 2025, no 24-80.903, publié au Bulletin
Beyond species means – the intraspecific contribution to global wood density variation
No full textInternational audienceWood density is central for estimating vegetation carbon storage and a plant functional trait of great ecological and evolutionary importance. However, the global extent of wood density variation is unclear, especially at the intraspecific level. We assembled the most comprehensive wood density collection to date, including 109 626 records from 16 829 plant species across woody life forms and biomes (GWDD v.2, available here: doi: 10.5281/zenodo.16919509 ). Using the GWDD v.2, we explored the sources of wood density variation within individuals, within species and across environmental gradients. Intraspecific variation accounted for c . 15% of overall wood density variation (SD = 0.068 g cm −3 ). Variance was 50% smaller in sapwood than heartwood, and 30% smaller in branchwood than trunkwood. Individuals in extreme environments (dry, hot and acidic soils) had higher wood density than conspecifics elsewhere (+0.02 g cm −3 , c . 4% of the mean). Intraspecific environmental effects strongly tracked interspecific patterns ( r = 0.83) but were 70–80% smaller and varied considerably among taxa. Individual plant wood density was difficult to predict (root mean square error > 0.08 g cm −3 ; single‐measurement R 2 = 0.59). We recommend (1) systematic sampling of multiple individuals and tissues for local applications, and (2) expanded taxonomic coverage combined with integrative models for robust estimates across ecological scales.La densidad de la madera es fundamental para estimar el almacenamiento de carbono vegetal y constituye un rasgo funcional de gran importancia ecológica y evolutiva. Sin embargo, el alcance global de la variación de la densidad de madera no está claramente descrito, especialmente a nivel intraespecífico. Recopilamos la colección más completa de densidad de madera hasta la fecha, que incluye 109 626 registros de 16 829 especies de plantas leñosas de diversas formas de vida y biomas (GWDD v.2, disponible aquí: doi: 10.5281/zenodo.16919509 ). Utilizando la GWDD v.2, exploramos las fuentes de variación en la densidad de la madera entre individuos y especies, así como a través de gradientes ambientales. La variación intraespecífica representó aproximadamente el 15% de la variación total de la densidad de la madera (SD = 0.068 g cm −3 ). La varianza fue un 50% menor en la albura que en el duramen, y un 30% menor en la madera de ramas que en la del tronco. Los individuos en ambientes extremos (secos, cálidos, suelos ácidos) presentaron una densidad de madera mayor que sus congéneres en otros lugares (+0.02 g cm −3 , ~4% de la media). Los efectos ambientales intraespecíficos siguieron estrechamente los patrones interespecíficos ( r = 0.83), sin embargo, resultaron entre un 70% y un 80% menores y variaron considerablemente entre los taxones. La densidad de madera por individuo fue difícil de predecir (RMSE >0.08 g cm −3 ; R 2 de medición única = 0.59). Recomendamos (1) el muestreo sistemático intraespecífico de múltiples individuos para aplicaciones locales y (2) una cobertura taxonómica ampliada combinada con modelos integradores para obtener estimaciones robustas a través de las escalas ecológicas.La densité du bois est essentielle pour estimer le stockage de carbone de la végétation et constitue un trait fonctionnel d’une grande importance écologique et évolutive. Cependant, l’ampleur de la variation globale de la densité du bois reste mal caractérisée, en particulier au niveau intraspécifique. Nous avons rassemblé la base de données la plus complète à ce jour sur la densité du bois, comprenant 109 626 mesures provenant de 16 829 espèces de plantes ligneuses appartenant à diverses formes de vie et biomes (GWDD v.2, disponible ici: doi: 10.5281/zenodo.16919509 ). À l’aide de la GWDD v.2, nous avons exploré les sources de variation de la densité du bois au sein des individus, au sein des espèces et le long de gradients environnementaux. La variation intraspécifique représentait environ 15% de la variation totale de la densité du bois (SD = 0,068 g cm −3 ). La variance était 50% plus faible dans l’aubier que dans le duramen, et 30% plus faible dans le bois des branches que dans celui du tronc. Les individus vivant dans des environnements extrêmes (secs, chauds, sols acides) présentaient une densité du bois plus élevée que leurs congénères ailleurs (+0,02 g cm −3 , soit ~4% de la moyenne). Les effets environnementaux intraspécifiques reflétaient les tendances interspécifiques ( r = 0,83), mais étaient 70 à 80% plus faibles et variaient considérablement entre taxons. La densité du bois à l’échelle individuelle était difficile à prédire (RMSE >0,08 g cm −3 ; R 2 = 0,59). Nous recommandons (1) un échantillonnage systématique de plusieurs individus et tissus pour les applications locales et (2) un élargissement de la couverture taxonomique combiné à des modèles intégratifs afin d’obtenir des estimations robustes à travers les échelles écologiques
Attributable mortality of ICU-acquired bloodstream infections: Impact of the source, causative micro-organism, resistance profile and antimicrobial therapy
No full textInternational audienc
Global dynamics of antibiotic resistance: a modeling study of the spread of endemic and emerging resistance in E. coli
No full textBackground Antibiotic resistance (ABR) poses a growing threat at the global level. Emergence and worldwide dissemination of multi-resistant clones are frequently reported. However, associated drivers are still largely unknown and are a crucial knowledge to mitigate ABR risk in humans. Methods We used mechanistic modeling to analyze annual trends of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) in 39 countries over 2006-2019. The model formalizes ESBL-EC transmission, colonization and infection at the country and global levels, accounting for heterogeneous antibiotic prescriptions and human mobility. The fitted model is used to explore hypothetical scenarios of emerging antibiotic-resistant clones like carbapenem-resistant E. coli (CR-EC) and evaluate their global dissemination risk. Findings International travels alone do not explain heterogeneous ESBL-EC dynamics. Reproducing observed trends requires accounting for antibiotics impact on ESBL-EC acquisition and heterogeneous within-country transmission rates. Strong differences in transmission rates are inferred between Europe and South-East Asia, ranging on average from 7.05×10 - 3 day -1 in Spain to 16.21×10 -3 day -1 in Thailand. For CR-EC, spatiotemporal dynamics depends on the explored emergence scenario. We show that mobility patterns drive 5-years resistance dynamics, while 20-years dynamics are mostly predicted by within-country transmission and antibiotic use. Interpretation This spatiotemporal analysis highlights the weight of international travel in the early global dissemination of antibiotic-resistant clones but suggests that reducing transmission and selection pressure is fundamental to avoid fixation. There is a need to strengthen surveillance and data collection of community colonization and infection to refine modeling and support decision and ABR control at the global scale. Funding Pfizer independent medical grant (number 57504809
Vision organisante de l’IA générative dans la supply chain : analyse des représentations
No full textFNEGE 3International audienceCet article mobilise la fonction d’interprétation de la vision organisante afin d’analyser les représentations attribuées à l’IA Générative dans la Supply Chain par des acteurs professionnels impliqués dans la production et la diffusion de discours sur cette technologie. L’étude repose sur l’analyse de 42 discours publics d’experts, de fournisseurs de solutions et d’adopteurs précoces diffusés sur YouTube, à l’aide d’une démarche méthodologique mixte combinant analyse de contenu et analyse factorielle des correspondances. Les résultats mettent en évidence l’émergence d’une vision organisante structurée autour de trois représentations principales de l’IA Générative : un instrument d’efficacité, un catalyseur d’intelligence augmentée et un outil d’aide à la décision. Ces interprétations demeurent toutefois générales et encore faiblement ancrées dans les réalités opérationnelles de la Supply Chain, suggérant une vision organisante précoce et non stabilisée. L’étude contribue aux travaux sur les dynamiques sociotechniques de la Supply Chain en montrant comment des représentations collectives orientent l’interprétation d’une technologie émergente. Elle souligne également l’intérêt méthodologique de l’analyse de discours professionnels diffusés sur des plateformes numériques et met en lumière les enjeux managériaux liés à la préparation de l’intégration de l’IA Générative dans les systèmes d’information logistiques existants
Santé mentale en tension Enjeux épistémologiques, politiques et cliniques d’un espace fragmenté
No full textInternational audienceObjectivesMental health has emerged as a major policy issue at the crossroads of health, political, and ethical concerns. Declared a “national cause” in 2025 and 2026, it is receiving renewed attention while the associated theoretical paradigms and public programs are the subject of intense debate. In this context, an interdisciplinary workshop entitled “Mental Health Policies: Pluralistic Concepts and Perspectives” was held in June of 2025. The event aimed to foster dialogue between researchers, clinicians, and institutional actors regarding the tensions that structure the mental health landscape.Materials and methodsWe report the discussions that took place during this workshop based on an inductive analysis of the exchanges using Braun and Clarke's (2006) method. The corpus, consisting of all interactions, was coded into more than 1700 segments grouped into thematic axes, then manually refined.ResultsFirst, the lack of collective representation of care providers appears to be a persistent consequence of a fragmented health care organization. Care delivery modes and patient populations vary greatly, and the different paths (private practice, community-based care, academic–hospital settings, etc.) often operate in silos. While this diversity reflects initiative and innovation, it does not uphold an unified voice. Second, paradigmatic reframing is considered necessary, integrating prevention, diagnosis, and care. New tools make it possible to articulate biological, clinical, social, or linguistic data without imposing a single overarching model. The objective is to create transparent, interoperable and inclusive methodologies between biomedical, psychodynamic, and social approaches to strengthen user involvement. . Third, in a context of budgetary constraint, it is also crucial to re-allocate funding toward what is most useful for care. This requires identifying financing mechanisms that promote good practices through appropriate incentives and support the many teams engaged in experimentation and evaluation.DiscussionThis workshop shed light on the major forces at play: an acknowledged plurality of approaches, constructive disagreements over evidence-based models, and a shared commitment to tying together the complexity of clinical situations and organizational structures. Its main contribution lies in bringing into dialogue worlds that rarely meet : clinical practice, social sciences, and institutions. The exchanges showed how these perspectives can enrich one another when they are articulated together.ConclusionOur team effort is expected to grow through further meetings , particularly on: (i) research policy issues in mental health (data and commons); (ii) the role of care providers, users, and caregivers in decision-making processes; and (iii) the financing of psychiatry (allocated budgets and psychotherapy coverage).ObjectifsLa santé mentale s’impose comme un enjeu sociétal majeur à la croisée de préoccupations sanitaires, politiques et éthiques. Déclarée « grande cause nationale » en 2025 et 2026, elle fait l’objet d’une attention renouvelée alors que les paradigmes théoriques et les politiques publiques qui s’y rattachent se trouvent au cœur de vifs débats. Dans ce contexte a été organisée en juin 2025 une journée d’étude interdisciplinaire intitulée « Politiques de santé mentale : concepts et perspectives pluriels », rencontre visant à faire dialoguer chercheurs, cliniciens et acteurs institutionnels autour des tensions qui structurent l’espace de la santé mentale.Matériels et méthodesNous restituons les propos tenus dans le cadre de cette journée à partir d’une analyse inductive fondée sur la méthode de Braun et Clarke (2006). Le corpus constitué de l’intégralité des échanges a été codé en plus de 1700 segments regroupés en axes thématiques, avant d’être manuellement retravaillé.RésultatsPrimo, le défaut de représentation des acteurs du soin apparaît le produit persistant de l’organisation du système de santé. Les contextes d’exercice et patientèles divergent, les circuits (libéral, secteur, hospitalo-universitaire, etc.) fonctionnent souvent en silos. Cette diversité, signe d’initiative, a pour revers une dilution du message collectif. Secondo, un refondement paradigmatique est jugé nécessaire, intégrant prévention, diagnostic et soins. De nouveaux outils peuvent articuler données biologiques, cliniques, sociales ou linguistiques, sans imposer un modèle unique. Il s’agit de créer des espaces de partage entre approches biomédicales, psychodynamiques et sociales, de renforcer la participation des usagers, et de s’appuyer sur des méthodologies transparentes, interopérables et inclusives. Tertio, dans un contexte de restriction budgétaire, il semble prioritaire de rediriger les fonds vers ce qui est utile aux soins. Il s’agit d’identifier des modes de financement qui soutiennent les bonnes pratiques, les nombreuses équipes qui expérimentent et évaluent.DiscussionCette journée d’étude a permis de rendre visibles les lignes de force à l’œuvre : une pluralité d’approches assumée, des désaccords argumentés sur les cadres de preuve, ainsi que la volonté partagée de tenir ensemble la complexité des situations cliniques et des organisations. L’apport principal tient à la mise en relation de mondes qui dialoguent rarement dans le même temps : clinique, sciences sociales, et institutions. Les échanges ont montré comment ces registres peuvent s’enrichir mutuellement lorsqu’ils sont articulés.ConclusionNotre collectif est amené à se densifier et de nouveaux temps d’échanges sont prévus, notamment sur : (i) les thématiques des politiques de recherche en santé mentale (données et communs) ; (ii) la place des soignants, des usagers et des aidants dans les processus décisionnaires ; (iii) le financement de la psychiatrie (budgets alloués et remboursement des psychothérapies)
Detection of ozone recovery in the Arctic from ground-based measurements
No full textInternational audienceContrary to the Antarctic, where ozone recovery has been observed for about a decade, the detection of positive ozone trends in the Arctic remains challenging due to higher natural variability of ozone in that region. Using a merging of long-term ozone data from Fourier transform infrared spectrometers, ozonesondes, and Dobson and Brewer spectrophotometers, we present regional long-term trends (2000−2024) for total, stratospheric and tropospheric ozone. First, ground-based measurements are cross-compared to two satellite data sets (MEGRIDOP and IASI-CDR). This enables the detection of drifted ground-based data sets we further exclude from our study. We then use a representativeness study based on CAMS re-analysis data to define regions for which representative trends with reduced uncertainties are obtained by combining data sets from different instruments and stations. Annual and seasonal trends are calculated using a multiple linear regression technique involving a set of proxies that represent physical processes influencing the natural ozone variability. Annual trends indicate increasing total ozone over the Arctic, and are statistically significant over Canada and Reykjavik (+2.1 %/decade) and North-West Europe (Harestua and Lerwick, +0.7 %/decade). Ozone recovery is also observed over Canada in the mid-stratosphere (+2.0 %/decade) and over the North Pole region (Canada and Ny-Ålesund) in the upper stratosphere (+2.1 to +3.8 %/decade). By analysing the sensitivity of the ozone trends to the proxies, we observe a slow down of the expected ozone recovery, especially in the lower stratosphere, due to stratospheric cooling (-0.6 %/decade) and to the increase of volume of polar stratospheric clouds (-0.8 %/decade)
To what extent are the IASI water vapour profiles representative of the conditions in the autumn before the HPE? Lessons learned from the WaLiNeAs campaign
No full textInternational audienceThe WaLiNeAs campaign took place along the north-western Mediterranean coast between October 2022 and January 2023. This period was marked by unusual weather conditions associated with dry autumn and winter. In such conditions and for the first time, eight ground-based stations equipped with water vapour Raman lidars were strategically deployed by four European countries. We studied the consistency of this network with the water vapour mixing ratio (WVMR) products derived from the Infrared Atmospheric Sounding Interferometer (IASI) and the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA5), which assimilate IASI radiances. The statistical metrics used in the comparison are the mean bias (MB, defined as lidar -IASI or ERA5), the root mean square error (RMSE) and the correlation coefficient (COR). A positive MB of approximately 0.9 g kg -1 (respectively 0.6 g kg⁻¹) between 0.2 and 5 km above mean sea level (amsl) indicates a systematic underestimation of the WVMR by IASI (respectively ERA5). RMSE values range from 1 to 2 g kg -1 across all lidar stations for IASI and ERA5, while the measurement uncertainties of the lidars are typically below 0.4 g kg -1 . COR presents little variation between stations, it ranges from 0.7 to 0.8 and remains almost constant between 0.2 and 5 km amsl. Both the IASI and the ERA5 products appear to accurately reproduce the temporal variability of the vertical structure of water vapour in the low troposphere. Nevertheless, they show MB and RMSE significantly above the uncertainties of lidar measurements
Effect of noise characterization on the detection of mHz stochastic gravitational waves
No full textInternational audiencePulsar timing arrays' hint for a stochastic gravitational-wave background (SGWB) leverages the expectations of a future detection in the millihertz band, particularly with the LISA space mission. However, finding an SGWB with a single orbiting detector is challenging: It calls for cautious modelling of instrumental noise, which is also mainly stochastic. It was shown that agnostic noise reconstruction methods provide robustness in the detection process. We build on previous work to include more realistic instrumental simulations and additional degrees of freedom in the noise inference model and analyze the impact of LISA's sensitivity to SGWBs. Particularly, we model the two main types of noise sources with separate transfer functions and power spectral density spline fitting. We assess the detectability bounds and their dependence on the flexibility of the noise model and on the prior probability, allowing us to refine previously reported results