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Striatal astrocytes modulate behavioral flexibility and whole-body metabolism in mice
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History of the sedimentary regimes of the Aquitaine margin (Bay of Biscay, France) at the outlet of its main tributaries during the last millennium: a mirror of the North Atlantic and European climates
No full textInternational audienceThe present work is based on the analysis of two hemipelagic sequences collected off the two main fluvial tributaries that enter the southern Bay of Biscay along the Aquitaine margin: the Gironde estuary, for core JB7-ST3c retrieved from the West-Gironde mud patch; and the Adour river, for core MD03–2693 retrieved from the Capbreton canyon meanders. Their positioning, at the northern and southern edges of the Aquitaine shelf, not only allows us to obtain a synoptic view of the southern Bay of Biscay past oceanography, but, over the last thousand years covered by these archives, also provides access to key contextual elements related to local as well as global hydroclimatic forcings. This article focuses on the interpretation of the sedimentological signal based on key X-ray fluorescence (XRF) elemental profiles obtained along the cores, within the framework of coherent age models newly built for the two sequences. The consistency of the two records allows us to robustly relate the evolution of the XRF profiles to the hydroclimatic regime of the Bay of Biscay, and to compile and discuss a chronicle of the environmental events that have marked the sites. This is achieved through a regional scale analysis, encompassing synchronous occurrences on the proximate continent, complemented by a broader synoptic perspective within the context of the well-documented European and North Atlantic historical frames. This chronicle is pivotal in comprehending the correlation between continental and oceanic regimes along the Euro-Atlantic margin, in addition to their links to the climatic processes that govern the Northern Hemisphere region.Our results clearly discriminate specific climatic trends, highlighting the Medieval Warm Period, the Little Ice Age and the Current Warm Period as contrasted intervals. The climatic patterns identified during these specific phases are discussed in the light of recent advances in our knowledge of their modes of variability, and raise the question of teleconnections between the North Atlantic Oscillation, Atlantic sea-surface conditions and dynamics, together with atmospheric ones and especially storminess over Europe
Very-wide-orbit planets from dynamical instabilities during the stellar birth cluster phase
No full textInternational audienceOur understanding of the process of terrestrial planet formation has grown markedly over the past 20 years, yet key questions remain. This review begins by first addressing the critical, earliest stage of dust coagulation and concentration. While classic studies revealed how objects that grow to meter sizes are rapidly removed from protoplanetary disks via orbital decay (seemingly precluding growth to larger sizes), this chapter addresses how this is resolved in contemporary, streaming instability models that favor rapid planetesimal formation via gravitational collapse of solids in over-dense regions. Once formed, planetesimals grow into Mars-Earth-sized planetary embryos by a combination of pebble- and planetesimal accretion within the lifetime of the nebular disk. After the disk dissipates, these embryos typically experience a series of late giant impacts en route to attaining their final architectures. This review also highlights three different inner Solar System formation models that can match a number of empirical constraints, and also reviews ways that one or more might be ruled out in favor of another in the near future. These include (1) the Grand Tack, (2) the Early Instability and (3) Planet Formation from Rings. Additionally, this chapter discusses formation models for the closest known analogs to our own terrestrial planets: super-Earths and terrestrial exoplanets in systems also hosting gas giants. Finally, this review lays out a chain of events that may explain why the Solar System looks different than more than 99% of exoplanet systems
Benchmark of computational methods to detect digenism in sequencing data
No full textInternational audienceDigenic inheritance is characterized by the combined alteration of two different genes leading to a disease. It could explain the etiology of many currently undiagnosed rare diseases. With the advent of next-generation sequencing technologies, the identification of digenic inheritance patterns has become more technically feasible, yet still poses significant challenges without any gold standard method. Here, we present a comprehensive overview of the existing methods developed to detect digenic inheritance in sequencing data and provide a classification in cohort-based and individual-based methods. The latter category of methods appeared the most applicable to rare diseases, especially the ones not needing patient phenotypic description as input. We discuss the availability of the different methods, their output and scalability to inform potential users. Focusing on methods to detect digenic inheritance in the case of very rare or heterogeneous diseases, we propose a benchmark using different real-life scenarios involving known digenic and putative neutral pairs of genes. Among these different methods, DiGePred stood out as the one giving the least number of false positives, ARBOCK as giving the greatest number of true positives, and DIEP as having the best balance between both. By synthesizing the state-of-the-art techniques and providing insights into their practical utility, this benchmark serves as a valuable resource for researchers and clinicians in selecting suitable methodologies for detecting digenic inheritance in a wide range of disorders using sequencing data
Advances in Logic-Based Entity Resolution: Enhancing ASPEN with Local Merges and Optimality Criteria
No full textInternational audienceWe present ASPEN + , which extends an existing ASP-based system, ASPEN, for collective entity resolution with two important functionalities: support for local merges and new optimality criteria for preferred solutions. Indeed, ASPEN only supports so-called global merges of entity-referring constants (e.g. author ids), in which all occurrences of matched constants are treated as equivalent and merged accordingly. However, it has been argued that when resolving data values, local merges are often more appropriate, as e.g. some instances of 'J. Lee' may refer to 'Joy Lee', while others should be matched with 'Jake Lee'. In addition to allowing such local merges, ASPEN + offers new optimality criteria for selecting solutions, such as minimizing rule violations or maximizing the number of rules supporting a merge. Our main contributions are thus (1) the formalization and computational analysis of various notions of optimal solution, and (2) an extensive experimental evaluation on real-world datasets, demonstrating the effect of local merges and the new optimality criteria on both accuracy and runtime.</div
Online knapsack with removal and recourse
No full textInternational audienceWe analyze the competitive ratio of the proportional online knapsack problem with removal and limited recourse. In contrast to the classical online knapsack problem, packed items can be removed and a limited number of removed items can be re-inserted to the knapsack. The variant with removal only was analyzed by Iwama and Taketomi (ICALP, 2002). We show that even a single use of recourse can improve the performance of an algorithm. We give lower bounds for a constant number of k ≥ 1 uses of recourse in total, matching upper bounds for 1 ≤ k ≤ 3, and a general upper bound for any value of k. For a variant where a constant number of k ≥ 1 uses of recourse can be used per step, we give tight bounds for all k ≥ 1. We further look at a scenario where an algorithm is informed when the instance ends and give improved upper bounds in both variants for this case
Surface-dependent reorganization of Chlorella vulgaris cell wall components revealed by AFM and SRS microscopy
No full textInternational audienceCharacterization of microalgae cell wall properties using Atomic Force Microscopy (AFM) depends critically on the immobilization strategy employed. In this study, we investigated how various immobilization surfaces influence the biophysical properties of the Chlorella vulgaris cell wall as probed by AFM. Cells were immobilized on three distinct surfaces, each leveraging different types of interactions with cells: polyoctyl-(PO)-Chitosan-coated glass slides promoting hydrophobic interactions, Superfrost™ positively charged glass slides that interact hydrophobically and electrostatically with cells, and PDMS chambers that immobilize cells through mechanical confinement. AFM imaging, nanoindentation, and force spectroscopy revealed that the biophysical properties of the Chlorella vulgaris cell wall strongly depend on the immobilization strategy. At the same time, all other experimental conditions were kept identical. Cells attached to PO-Chitosan through hydrophobic interactions displayed high surface roughness, higher rigidity, hydrophobic behavior, and positive surface charges. In contrast, cells immobilized on positively charged but less hydrophobic Superfrost™ slides exhibited smoother surfaces, lower rigidity, reduced hydrophobicity, and no detectable positive charges. Cells confined in PDMS chambers exhibited the smoothest and softest cell walls, characterized by hydrophilic and uncharged surfaces. Complementary Stimulated Raman Scattering (SRS) microscopy experiments confirmed distinct lipid rearrangements associated with each immobilization method.Together, these results support the hypothesis formulated in this study that immobilization surfaces can cause the reorganization of cell wall components-polysaccharides, proteins, and lipids-thereby reshaping the physico-chemical and mechanical surface properties. This study thus demonstrates the great significance of immobilization strategies to ensure the reliability of nanoscale biophysical measurements in microalgae research
Synthesis of Electron-Deficient BisAzaCoroneneDiimide-Conjugated Polymers by Light-Locking Dynamic Covalent Bonds
No full textInternational audienceWe present a novel light-locked dynamic covalent polymerization methodology to synthesize conjugated polymers based on BisAzaCoroneneDiimides (BACDs). This metal-free process converts reversible poly imines into kinetically locked conjugated polymers using visible light, generating minimal side products. By incorporating aldehyde-functionalized comonomers, the approach enables the creation of diverse n-type semiconducting polymers with tunable optical band gaps and low LUMO levels. The polymers exhibit exceptional thermal, electrochemical, and photostability with strong interchain interactions upon electrochemical reduction observed in solution, attributed to the BACD core. Broad absorption from the visible to the near-infrared range underscores their potential in charge and energy transport applications for organic electronics. This scalable, sustainable strategy unlocks access to a versatile class of n-type diimide polymers
Stratégie d’optimisation des inséminations intra-utérines avec sperme de donneur depuis l’entrée en vigueur de la loi de bioéthique de 2021 : cohorte rétrospective monocentrique au CHU de Bordeaux
No full textBackground: opening assisted reproductive technology (ART) to female couples and single women led to a sharp increase in requests for donor-sperm intrauterine insemination (IUI) in a context of limited availability of donor sperm. Objective: to identify factors influencing the live birth rate (LBR) in order to optimize patient Materials and Methods: single-center retrospective study including 1,315 IUI-D cycles performed in 433 women between january 2022 and october 2024. The primary outcome was live birth rate (LBR). Results: Per-cycle LBR was 14.8%, reaching 45% after six cycles, with a plateau from the 4th/5th attempt. In univariable analyses, age, ovarian reserve, relationship status, and the number of motile sperm inseminated (TMS) were associated with success. In multivariable analysis, only age (p<0.001) and number of motile spermatozoa inseminated (NMSI) remained significant (p<0.05). Neither a “blind” ovulation trigger without ultrasound monitoring nor the use of GnRH antagonists impacted LBR. Conclusion: an optimal strategy should consider maternal age (prioritizing, where feasible, patients <37 years), TMS (a threshold around 1.5 to 2 million appears relevant), and limiting the number of IUI-D attempts (four before transitioning to iIn vitro fertilisation (IVF)), while tailoring stimulation and trigger modalities (including the possible use of antagonists and a blind trigger). These elements support a rational approach in a setting of rising demand and constrained donor-sperm resources.Contexte : l’ouverture de l’aide médicale à la procréation (AMP) aux couples de femmes et aux femmes célibataires a entraîné une forte augmentation des demandes d’insémination artificielle avec spermatozoïdes de donneur (IAD), dans un contexte de ressources limitées en paillettes de donneurs. Objectif : identifier les facteurs influençant le taux de naissance vivante afin d’optimiser la prise en charge. Matériel et Méthode : étude rétrospective monocentrique incluant 1 315 cycles d’IAD réalisés chez 433 femmes entre janvier 2022 et octobre 2024. Critère principal : taux de naissance vivante (LBR). Résultats : le LBR par cycle était de 14,8 %, atteignant 45 % après six cycles, avec un plateau dès la 4/5ᵉ tentative. En analyse univariée, l’âge, la réserve ovarienne, le statut relationnel et le nombre de spermatozoïdes mobiles inséminés (NSMI) influençaient le succès. En analyse multivariée, seuls l’âge (p<0,001) et le NSMI restaient significatifs (p<0,05). Le déclenchement à l’aveugle et l’utilisation d’antagonistes n’avaient pas d’impact sur le LBR. Conclusion : ainsi, la stratégie optimale repose sur une prise en compte de l’âge maternel (favoriser les patientes de moins de 37 ans quand c’est possible), du NSMI (un seuil autour de 1.5 voir 2 millions semblant pertinent) et de la limitation du nombre de tentatives (4 avant un passage en fécondation in vitro (FIV)), tout en intégrant des modalités de stimulation et de déclenchement adaptées (utilisation d’antagoniste et déclenchement à l’aveugle). Ces éléments offrent une stratégie rationnelle face à la demande croissante et aux ressources limitées