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GWTC-4.0: Population Properties of Merging Compact Binaries
No full textInternational audienceWe detail the population properties of merging compact objects using 158 mergers from the cumulative Gravitational-Wave Transient Catalog 4.0, which includes three types of binary mergers: binary neutron star, neutron star--black hole binary, and binary black hole mergers. We resolve multiple over- and under-densities in the black hole mass distribution: features persist at primary masses of and with a possible third feature at . These are departures from an otherwise power-law-like continuum that steepens above . Binary black holes with primary masses near are more likely to have less massive secondaries, with a mass ratio distribution peaking at , potentially a signature of stable mass transfer during binary evolution. Black hole spins are inferred to be non-extremal, with 90% of black holes having , and preferentially aligned with binary orbits, implying many merging binaries form in isolation. However, we find a significant fraction, 0.24-0.42, of binaries have negative effective inspiral spins, suggesting many could be formed dynamically in gas-free environments. We find evidence for correlation between effective inspiral spin and mass ratio, though it is unclear if this is driven by variation in the mode of the distribution or the width. (Abridged
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
Reconstructing landscape configuration, vegetation history and land-use in the coastal area of two Western Mediterranean Islands (Corsica and Cavallo Islands): Evidence for a Roman environmental tipping point
No full textInternational audienceThis paper reconstructs coastal landscape evolution, together with its vegetation history and land use on the Osu coastal plain (southeastern Corsica) and on Cavallo Island, two areas with well attested human presence, notably during Roman times. Ten vibrocores reaching depths of up to 4.20 m were recovered and analysed using a multi-proxy approach combining sedimentological analyses, mollusc identification, pollen and non pollen palynomorphs (NPPs) analysis. In addition, a total of 20 radiocarbon datings have enabled to obtain a chronostratigraphy for both studied areas. Our results reveal a delta progradation of the Osu River with two main phases of shoreline advance dated from the Early Bronze Age and the Roman Empire. On Cavallo Island, which was exploited for its mineral resources (granite) during Roman times, our results bring to light for the first time the presence of a freshwater wetland in the north central part of the island dating from the Bronze Age to the Late Roman times. High eutrophication of the water body then occurred, ending only when artificial silting up happened during the second half of the 20 th Century CE. Pollen records indicate early agricultural activities on the Osu deltaic plain from the Final Neolithic/Chalcolithic onwards, with further expansion during the Early Bronze Age and the Early Iron Age. At Cavallo, there is no clear evidence of agricultural activity from the Middle Bronze Age to the Early Genoese period. At a broader, island-wide scale, Roman-period agriculture intensified preexisting land-use systems rather than initiating them, leading in many Corsican coastal areas to a marked and irreversible opening of arboreal and Erica formations. These transformations were spatially heterogeneous, with more limited landscape change in the San Ciprianu area compared to other regions, and were accompanied by increasing agricultural specialisation during the Roman Empire, notably between cereal-dominated systems in lowland eastern coastal plains and olive cultivation in other coastal sectors (e.g. north-west)
Pseudogenes Document Protracted Parallel Regression of Oral Anatomy in Myrmecophagous Mammals
No full textInternational audienceAdaptation to ant and/or termite consumption (myrmecophagy) in mammals constitutes a textbook example of convergent evolution, being independently derived in several mammalian lineages. Myrmecophagous species are characterized by striking convergent morphological adaptations such as skull elongation, enlargement of salivary glands, and long claws to dig into ant and termite nests. These evolutionary modifications also include anatomical regression, such as dental simplification or loss, reduction of masticatory muscles, and possessing a reduced set of taste buds. To gain insights into the molecular changes underlying the regression of these morpho-anatomical traits, we investigated the functionality of candidate genes related to dentition, gustation, and mastication in nine convergent myrmecophagous mammalian lineages. We examined these genes in a comparative phylogenetic context, paired with molecular evolutionary analyses, to estimate the relative timing of loss of gene function over the evolutionary history of each convergent lineage. We found that gustatory reduction and pseudogenization of masticatory myosin often were associated with the regression of dental genes. Evidence of pseudogenization events linked to oral anatomy dates to as early as the Cretaceous/Paleogene boundary, and is an ongoing process including examples of incipient gene inactivations. Whereas we found evidence for gene inactivations across all three functional categories occurring during distinct temporal intervals, there was variation in the sets of genes lost and the relative timing of inactivation events. The combined evidence suggests that the convergent evolution of myrmecophagy has occurred as a protracted process with distinct phases of anatomical evolution, over timescales as long as 60 Myr
"La femme du patron". Mme de Pomponne, intendante d'ambassadeurs ?
No full textInternational audienceThe article discusses the role of Catherine Ladvocat, who managed her husband Simon Arnauld de Pomponne's affairs when he was sent abroad as ambassador. But beyond this marital arrangement, she is seen to play the same role for other diplomats who are members of the family (Feuquières, Rébenac, etc.), which raises questions about her status, the role of women, and the professionalisation of the administration under the Ancien Régime.L'article discute le rôle de Catherine Ladvocat, qui gère les affaires de son mari Simon Arnauld de Pomponne quand ce dernier est envoyé à l'étranger comme ambassadeur. Mais au-delà de cet arrangement conjugal, on la voit jouer le même rôle pour d'autres diplomates membres de la famille (Feuquières, Rébenac...) ce qui pose la question de son statut, du rôle des femmes et de la professionnalisation de l'administration sous l'Ancien Régim
Convergence of Multi-Level Markov Chain Monte Carlo Adaptive Stochastic Gradient Algorithms
No full textStochastic optimization in learning and inference often relies on Markov chain Monte Carlo (MCMC) to approximate gradients when exact computation is intractable. However, finite-time MCMC estimators are biased, and reducing this bias typically comes at a higher computational cost. We propose a multilevel Monte Carlo gradient estimator whose bias decays as while its expected computational cost grows only as , where is the maximal truncation level at iteration n. Building on this approach, we introduce a multilevel MCMC framework for adaptive stochastic gradient methods, leading to new multilevel variants of Adagrad and AMSGrad algorithms. Under conditions controlling the estimator bias and its second and third moments, we establish a convergence rate of order up to logarithmic factors. Finally, we illustrate these results on Importance-Weighted Autoencoders trained with the proposed multilevel adaptive methods
Living on the edge: investigating experiences of poverty through the lens of the Desperation Threshold Model
No full textThe Desperation Threshold Model (DTM) seeks to explain conflicting findings about the risk propensity of people living in poverty. It makes assumptions about their experiences: that they have a conception of basic needs, that their ability to meet these motivates their decisions, and that they modulate risky decisions depending on their ability to do so. The realism of these modeling assumptions has not yet been investigated. To start filling this gap, we investigated experiences of poverty through the lens of the DTM, using two complementary approaches: a pre-registered online survey with British participants (n = 300) and semi-structured qualitative interviews with very low-income individuals in France (n = 14). Our results imply that basic needs have both a context-general component and context-specific elaborations. Furthermore, participants often relied on social and institutional resources when experiencing financial adversity, indicating that only measuring personal income or wealth might not accurately capture the resources available to people. With respect to the DTM’s main predictions, most individuals close to—but still above—the desperation threshold exhibited caution and took a safety-first approach, consistent with risk-averse behavior. Risky or antisocial behaviors (e.g., cheating, stealing) emerged only in rare instances of severe financial hardship and complete lack of external support. These results suggest that the DTM’s main assumptions are empirically grounded but that they need to be qualified in specific ways. They also suggest that abstract models like the DTM can capture something about the experience of people living in conditions of poverty
Interim vaccine effectiveness against influenza virus among outpatients, France, October 2025 to January 2026
No full textInternational audienceIn Europe, the 2025/26 seasonal influenza epidemic started in October 2025. Co-circulation of A(H3N2) and A(H1N1)pdm09 was observed in several countries including France. We estimated early vaccine effectiveness (VE) against influenza virus in French outpatients (5,451 positives/18,816 negatives). A significant VE across all age groups was measured: 28% (95% CI: 17–37) for those aged ≥ 65 years, 45% (95% CI: 36–53) for 18–64-year-olds and 57% (95% CIs: 29–74) for 0–17-year-olds. Reinforcing vaccination uptake is warranted
Impact Evaluation of Parental Education Campaign on Child Development in Nepal
No full textThis study assesses the impacts of a parental education community training on childdevelopment in Nepal. Relying on a sample of approximately 1,000 households, we randomlyvary the access to the intervention. A few months after the end of the intervention, children inthe treatment group exhibit significantly higher scores on early childhood development indicators—both overall and across linguistic, motor, and cognitive domains. In turn, the interventionhas no sizable effects on anthropometric outcomes. Mechanism analysis reveals that the programimproves parental knowledge about child development and enhances the quality of parent-childinteractions
Le congé de paternité, prolongé et modulable, est largement adopté par les pères
No full textInternational audienceLa réforme du congé de paternité en 2021 a allongé sa durée et assoupli ses modalités. La part de pères prenant ce congé continue à augmenter, notamment chez ceux qui y avaient le moins recours comme les indépendants, les salariés en contrat à durée déterminée, les pères moins diplômés. La présence des pères au moment de la naissance se généralise et dure plus longtemps. Cependant, les contraintes professionnelles et financières restent un frein à la prise du congé. Même s’ils restent minoritaires, les pères qui prennent le congé « en solo », alors que la mère a repris le travail, sont de plus en plus nombreux