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Morphological traits and machine learning for genetic lineage prediction of two reef-building corals
No full textInternational audienceIntegrating multiple lines of evidence that support molecular taxonomy analysis has proven to be a robust method for species delimitation in scleractinian corals. However, morphology often conflicts with genetic approaches due to high phenotypic plasticity and convergence. Understanding morphological variation among species is crucial to studying coral distribution, life history, ecology, and evolution. Here, we present an application of Random Forest models for coral species identification based on morphological annotation of the corallum and corallites. We show that the integration of molecular and morphological trait analysis can be improved using machine learning. Morphological traits were documented for Porites and Pocillopora coral species that were collected and genotyped through genome-wide, genetical hierarchical clustering, and coalescence analyses for the Tara Pacific Expedition. While Porites only included three tentative species, most Pocillopora species were accounted by included specimens from the western Indian Ocean, tropical Southwestern Pacific, and southeast Polynesia. Two Random Forest models per genus were trained on the morphological annotations using the genetic lineage labels. One model was developed for in-situ image identification and used corallum traits measured from in-situ photographs. Another model for integrative species identification combined corallum and corallite data measured on scanning electron micrographs. Random Forest models outperformed traditional dimension reduction methods like PCA and FAMD followed by k-means and hierarchical clustering by classifying the correct genetic lineage despite morphological clusters overlapping. This machine learning approach is reproducible, cost-effective, and accessible, reducing the need for taxonomic expertise. It can complement molecular and phylogenetic studies and support image identification, highlighting its potential to advance a coral integrative taxonomy workflow
Circular Urban Metabolism in Action: The Design of the Promenade Nardal, Paris
No full textInternational audienceAs urban areas exert profound pressures on the natural environment, driving significant resource consumption and waste production, designers need to rethink the way urban projects are being developed. Therefore, this article advances the operationalization of the Circular Urban Metabolism (CUM) framework by analyzing a design case study: the Promenade Nardal in Paris. While CUM integrates the systemic material flow analysis of Urban Metabolism with the restorative strategies of the Circular Economy, it remains limited in its spatial articulation and applicability at the scale of urban design. Through a mixed-methods approach combining Life Cycle Assessment, spatial analysis, and qualitative inquiry, the article compares two circular design strategies, associated with the reuse of paving stones and the recycling of glass to produce Misapor, with conventional alternatives. Results demonstrate that stone reuse reduced CO2 emissions, energy demand, and water use, while Misapor showed energy and water advantages but slightly higher CO2 emissions due to production and transport. Beyond quantitative metrics, the study reveals the distinct design efforts and institutional frictions induced by circular practices, especially reuse, which requires adaptive aesthetics, labor-intensive design, and negotiation with technical norms. By spatializing material flows and foregrounding design agency, the article refines CUM as a situated and scalable framework, highlighting the need for context-sensitive, materially differentiated strategies in circular urban design
Impact of two-level filtering organization on population’s accessibility to an emergency medical communication centre
No full textInternational audienceBackground: Emergency Medical Communication Centres (EMCCs) play a critical role in the timely coordination of out-of-hospital emergency responses. As demand for emergency services continues to rise, these centres face significant challenges in maintaining operational efficiency and service quality in order to provide a priority response to life-threatening emergencies. While the two-level answering system - i.e. a two-tiered response by call takers - has shown promise in simulation studies, its effectiveness in real-world settings has yet to be fully evaluated.Objective: This study aimed to assess the impact of implementing a two-level answering system on service quality (rate of answered calls) at 30 s (QS30) across three EMCCs, marking the first evaluation of this system in everyday operations. We also investigated how variations in organizational structure among the EMCCs may influence QS30.Methods: We conducted a multicentric, observational, retrospective study analyzing call data collected between May and June of 2022 and 2023, in France. Three EMCCs-35, 44, and 86-were included, with EMCCs 35 and 44 having implemented the two-level system, while EMCC 86 served as the control. Each EMCC employed distinct organizational models for the two-level system. Key performance indicators were assessed using non-parametric statistical tests, including the Wilcoxon and Kruskal-Wallis tests. Additionally, structural equation modeling was used to explore relationships between variables affecting service quality.Results: A total of 255,438 calls were analyzed, with 152,108 calls during the two-level period. The QS30 for EMCC 35 ranged from 93% in 2022 to 91% in 2023 (p < 1e-4), while EMCC 44 saw an increase from 91 to 100% (p < 1e-4). In contrast, EMCC 86 maintained a stable QS30 of 100%, with no significant change in activity (p = 0.1). Further analysis revealed significant differences in QS30 across the three EMCCs, suggesting that the distinct organizational structures of the two-level systems influence overall service quality. Structural equation modeling also highlighted strong correlations between call volume, agent workload, and QS30, emphasizing the impact of staffing and organizational structure on service quality.Conclusion: The findings suggest that the two-level answering system may be effective in enhancing EMCC performance, particularly in managing increased call volumes. Additionally, the study highlights the potential importance of organizational differences in shaping QS30 outcomes. Future research should focus on longitudinal effects and explore innovative strategies to sustain high-quality EMCCs amidst evolving demands
Les diplomaties euro-africaines au tournant des indépendances
No full textInternational audienceComment passer d’un rapport impérial, fortement polarisé par une métropole, à des relations plus équilibrées, qui s’inscrivent dans un cadre associant des diplomaties bilatérales et multilatérales ? La question se pose aux États africains nouvellement indépendants. Croisant une histoire des relations internationales et une histoire sociale du politique, ce livre explore les reconfigurations des diplomaties euro-africaines, alors que le continent s’insère dans un système international dominé par les enjeux de Guerre froide et reconfiguré par l’arrivée des pays du Tiers-Monde.La boîte à outils de l’historien permet d’envisager cette vaste question de manière empirique. Fruit d’une collaboration entre les Archives diplomatiques et Nantes Université, l’ouvrage dresse un état des lieux des fonds diplomatiques français concernant l’Afrique au tournant des indépendances. Le dialogue entre archivistes et historiens met en lumière la richesse de ces archives et nourrit une réflexion méthodologique quant à leur interprétation.L’ouvrage examine la combinaison de continuités et de ruptures qui caractérise la décolonisation des relations entre Europe et Afrique. Aux Nations Unies, les États africains doivent prendre en compte les antagonismes de la Guerre froide, et tentent de renforcer leur place par des regroupements continentaux (panafricanisme) ou transcontinentaux (non-alignement, afro-asiatisme). L’ouvrage interroge aussi les notions d’aide et de développement – idéaux centraux de l’après-guerre – qui structurent les ambivalences des relations euro-africaines
Programme IMPULSION : implémentation du dépistage du cancer pulmonaire en population. Implication des soins primaires
No full textInternational audienceLe cancer du poumon est un enjeu de santé publique majeur. Son dépistage à un stade précoce permet des interventions curatives, mais reste sous-utilisé dans les programmes de santé, notamment en France. Inspiré des recommandations européennes actualisées, le Projet Pilote National IMPULSION, financé par l'INCa, propose d’évaluer l’efficacité et la faisabilité d’un programme national structuré, en combinant dépistage précoce et aide au sevrage tabagique. Un des objectifs du projet est de préciser les modalités de repérage et d’invitation les plus efficaces et celles qui assurent une équité dans le dépistage, en comparant plusieurs stratégies et en déployant des actions « d’aller vers ». La stratégie d'invitation ici présentée (MUST-MG) est celle réalisée par les médecins généralistes. Les individus éligibles, fumeurs ou anciens fumeurs âgés de 50 à 74 ans seront repérés dans la patientèle de ces médecins généralistes via des requêtes sur leur logiciel métier, et une invitation leur sera transmise par courrier signé par leur médecin généraliste
Le recensement des emplois vacants dans la fonction publique d'État. Perspective historique
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Impedance Based Synthesis of Circular Modulated Metasurface Antennas with Entire Domain Basis Functions
No full textInternational audienceThis paper presents a numerical technique for the synthesis of circular modulated metasurface antennas through impedance optimization of a metasurface using a Method of Moments (MoM) formulation. The metasurface is modeled as an inhomogeneous, transparent sheet impedance boundary condition (IBC) layer atop a grounded dielectric substrate. Both the current density over the aperture and the sheet impedance are expanded into orthogonal sets of entire-domain Fourier-Bessel basis functions (FBBFs). The optimization procedure tunes the expansion coefficients of the sheet impedance to achieve a desired far-field radiation pattern while ensuring a purely reactive IBC. An isotropic, azimuthally invariant metasurface antenna is designed that radiates a radial Gaussian beam to verify the proposed approach
Simulation expérimentale des phénomènes de mobilité augmentés par les échappements gazeux à basse pression atmosphérique
No full textInternational audiencePlanetary surfaces are transformed by various processes at different atmospheric pressures. On Mars, fluids are expected to have flowed at reduced atmospheric pressure during the last 3 billion years. Nevertheless, the influence of low pressure on surface processes has been investigated in only a few studies. Our understanding of the influence of gas in fluids on Martian surface morphologies is poor due to the low number of experiments performed at low atmospheric pressure (∼7 mbar) and the limited potential analogs on Earth. Here, we present laboratory and numerical experiments to explore the influence of gas production on fluid-sand mobility at low atmospheric pressure. Energetic cohesive sand pellets uplifted by escaping gas were generated, forming narrow channels with levees with lengths of 80-90 cm, which were approximately 1800 times their widths. The maximum experimentally determined velocity of the pellets ranged from 60 to 150 cm/s. The channel morphologies were formed by a pseudo-levitation mechanism corresponding to transport with reduced friction. We propose that the mechanisms observed in our experiments at low atmospheric pressure may explain some past Martian surface changes.Les surfaces planétaires sont transformées par différents processus de surface générant parfois une mobilité accrue. A basse pression atmosphérique, comme sur Mars lors des 3 derniers milliards d’années, la propagation des fluides à la surface en a été affectée. Cependant, les modes de transport à basse pression (7 mbar) ont été étudiés dans un nombre limité d’expérimentation, ce qui limite notre compréhension précise des écoulements de surface et des morphologies produites par ces processus. Notre connaissance de ce type d’écoulement est d’autant plus faible qu’il n’existe pas d’analogues évidents actuellement à la surface de la Terre. Dans cette étude, nous présentons des résultats expérimentaux et de modélisation sur le transport de matériel solide en présence d’échappements gazeux à basse pression. La propagation d’un mélange cohésif de sable humide, subissant une lévitation partielle causée par la vaporisation de l’eau au contact d’une surface granulaire, génère la formation d’un chenal érosif d’une longueur de 80–90 cm, de levées latéral et frontal à une vitesse comprise entre 60 et 150 cm/s. Ce phénomène est assimilable à une propagation avec une friction basale réduite, mais non nulle . Ce processus de transport et d’érosion pourrait s’être produit ou se produire encore à la surface de Mars
Genome-resolved biogeography of Phaeocystales, cosmopolitan bloom-forming algae
No full textInternational audiencePhaeocystales, comprising the genus Phaeocystis and an uncharacterized sister lineage, are nanoplanktonic haptophytes widespread in the global ocean. Several species form mucilaginous colonies and influence key biogeochemical cycles, yet their underlying diversity and ecological strategies remain underexplored. Here, we present new genomic data from 13 strains, including three high-quality reference genomes (N50 > 30 kbp), and integrate previous metagenome-assembled genomes to resolve a robust phylogeny. Divergence timing of P. antarctica aligns with Miocene cooling and Southern Ocean isolation. Genomic traits reveal metabolic flexibility, including mixotrophic nitrogen acquisition in temperate waters and gene expansions linked to polar nutrient adaptation. Concordantly, transcriptomic comparisons between temperate and polar Phaeocystis suggest Southern Ocean populations experience iron and B 12 limitation. We also identify signatures of horizontal gene transfer and endogenous giant virus/virophage insertions. Together, these findings highlight Phaeocystales as an ecologically versatile and geographically widespread lineage shaped by evolutionary innovation and adaptation to contrasting environmental stressors
Regorafenib plus modified gemcitabine-oxaliplatin in patients with advanced biliary tract cancer. The randomized phase Ib/II BREGO study
No full textInternational audienceBackground: New therapeutic options are needed for biliary tract cancer (BTC). Regorafenib, a multikinase inhibitor, shows promise in refractory digestive cancers and may be beneficial with conventional chemotherapy for BTC.Patients and Methods: The BREGO study evaluated regorafenib with modified gemcitabine-oxaliplatin (mGEMOX) in advanced or metastatic BTC. Phase I determined the recommended dose (RP2D) of regorafenib (80, 120 or 160 mg, days 1-14) combined with mGEMOX (gemcitabine 900 mg.m−2 IV, 30 min, followed by oxaliplatin 80mg.m−2 IV, 120 min, days 1 and 8). Phase II randomized (1:2) patients to mGEMOX alone (arm A) or mGEMOX + regorafenib (arm B, RP2D, days 1-14), assessing efficacy and safety, with the primary outcome being progression-free survival (PFS). Metabolic tumor features and response were also assessed.Results: In phase Ib, 22 patients were enrolled; in phase II, 66 patients (arm A, n = 24; arm B, n = 42). Four dose-limiting toxicities were observed, but no maximum tolerated dose was reached. The RP2D was 160 mg.d−1. Median PFS (7.2 vs7.8 months; P = .825) and overall survival (15.1 vs 13.5 months; P = .356) were similar between arms. However, posttreatment 18F-FDG tumor uptake (SULpeak) significantly correlated with PFS (P = .001) and OS (P = .016). Baseline plasma stanniocalcin 1 levels < 265 pg.mL−1 were associated with longer PFS (P = .030) and OS (P = .060) in both arms.Conclusions: Combining regorafenib and mGEMOX is feasible as first-line treatment for BTC but did not increase PFS as expected in the phase II cohort. Identifying new biomarkers can help target patients with advanced BTCs who may benefit from regorafenib-associated therapy