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Scaling relations at the central regions of nearby galaxies
No full textInternational audienceScaling relations between galactic parameters (e.g., luminosity, mass, metallicity, etc.) represent key pieces of evidence for investigating the processes of galaxy formation and evolution. In most studies, these relations have been obtained for large portions of the galaxies (i.e., on kiloparsec scales), but it is also important to evaluate these relations in smaller scales. In this work, we used optical data cubes of a subsample of nearby galaxies of the DIVING 3D survey. These allowed us to analyze the scaling relations involving stellar velocity dispersion, stellar population age, and stellar population metallicity at the nuclear and circumnuclear regions of galaxies (within scales from tens to a few hundreds of parsecs). We detected correlations between the stellar velocity dispersion and the age, metallicity, and total stellar mass. These correlations are independent of galaxy inclinations, considering all morphological types, nuclear activity, and the presence or absence of galactic bars. We detected, for the first time, a correlation between the stellar velocity dispersion and stellar metallicity in the nuclear regions of galaxies. It is found to be qualitatively consistent with the well-known stellar mass-metallicity relation, described in previous studies, on kiloparsec scales. We also noted that barred galaxies tend to show younger and less metal-rich stellar populations than unbarred galaxies in the central regions, which may be a consequence of the bar triggering star formation in the nuclear regions of these objects. However, further studies, with larger samples, are necessary for comparisons between barred and unbarred galaxies, with the same mass and morphological types. Some active galactic nuclei (AGNs) in our sample are positioned above the observed correlation between stellar velocity dispersion and stellar population age, suggesting that their nuclear stellar populations are younger than expected. This may be a consequence of positive AGN feedback, triggering star formation. Conversely, starburst galaxies do not show nuclear stellar populations at ages over one billion years
Nonequilibrium transport through an interacting monitored quantum dot
No full textWe study the interplay between strong correlations and Markovian dephasing, resulting from monitoring the charge or spin degrees of freedom of a quantum dot described by a dissipative Anderson impurity model. Using the Auxiliary master equation approach we compute the steadystate spectral function and occupation of the dot and discuss the role of dephasing on Kondo physics. Furthermore, we consider a two-lead setup which allows to compute the steady-state current and conductance. We show that the Kondo steady-state is robust to moderate charge dephasing but not to spin-dephasing, which we interpret in terms of dephasing-induced heating of low-energy excitations. Finally, we show universal scaling collapse of the non-linear conductance with a dephasing-dependent Kondo scale.</div
A multicellular star-shaped actin network underpins epithelial organization and connectivity
No full textInternational audienceEpithelial tissues withstand external stresses while maintaining structural stability. Bicellular junctions and the actomyosin network support epithelial integrity, packing and remodelling.While their role in development and disease are well studied, their synergistic impact on maintaining tissue organization remains unclear. Here, we identify a tissue-scale actomyosin network in adult murine intestinal villi, as well as in an ex vivo organoid-based epithelium model. This actomyosin network consists of repeated units of actin starsradial actin structures at the base of hexagonal cells-linked via bicellular junctions into multicellular array.Functionally, actin stars maintain epithelial morphological stability by preserving cell shape and packing. Laser ablation experiments support a modified vertex model, linking tension along actin star branches to epithelial arrangement. Additionally, actin stars act as basal locks, limiting protrusive activity, and hindering cell migration and tissue disruption. Together, these findings reveal the star-shaped supracellular actin network as a pivotal biomechanical system governing epithelial layer coordination.</p
Rapid emergence of a maths gender gap in first grade
No full textInternational audiencePreventing gender disparities in mathematics is a worldwide preoccupation. In infancy and early childhood, boys and girls exhibit similar core knowledge of number and space. Gender disparities in maths are, therefore, thought to primarily reflect an internalization of the sociocultural stereotype that ‘girls are bad at maths’. However, where, when and how widely this stereotype becomes entrenched remains uncertain. Here, we report the results of a 4-year longitudinal assessment of language and mathematical performance of all French first and second graders (2,653,082 children). Boys and girls exhibited very similar maths scores upon school entry, but a gender gap in favour of boys became highly significant after 4 months of schooling and reached an effect size of about 0.20 after 1 year. These findings were repeated each year and varied only slightly across family, class or school type and socio-economic level. Although schooling correlated with age, exploiting the near-orthogonal variations indicated that the gender gap increased with schooling rather than with age. These findings point to the first year of school as the time and place where a maths gender gap emerges in favour of boys, thus helping focus the search for solutions and interventions.Prévenir les disparités de genre en mathématiques est une préoccupation mondiale. Durant la petite enfance, filles et garçons présentent des connaissances fondamentales similaires des nombres et de l’espace. Les disparités de genre en mathématiques sont donc généralement interprétées comme le reflet de l’intériorisation progressive du stéréotype socioculturel selon lequel « les filles sont mauvaises en maths ». Cependant, le moment, le lieu et l’ampleur de l’ancrage de ce stéréotype restent incertains.Ici, nous présentons les résultats d’une étude longitudinale menée sur 4 ans, portant sur la performance linguistique et mathématique de l’ensemble des élèves français de CP et de CE1 (2 653 082 enfants). À leur entrée à l’école, garçons et filles obtenaient des scores très similaires en maths, mais un écart en faveur des garçons devenait hautement significatif après seulement 4 mois de scolarité, pour atteindre un effet d’environ 0,20 après un an.Ces résultats se sont répétés chaque année, avec des variations très faibles selon la famille, la classe, le type d’école ou le niveau socio-économique. Bien que la scolarisation soit corrélée à l’âge, l’analyse des variations quasi orthogonales montre que l’écart entre les genres augmente avec la scolarité plutôt qu’avec l’âge.Ces conclusions désignent donc la première année d’école comme le moment et le lieu où émerge un écart de genre en mathématiques en faveur des garçons, ce qui permet de mieux cibler les pistes de solutions et les interventions
Vieillir dans l’Antiquité : réalités antiques et enjeux contemporains
No full textInternational audienc
Dynamical Evolution of Planetary Systems
No full textThis is a preprint of the following work: Dynamical Evolution of Planetary Systems by A. C. Petit et al. (updating the chapter originally written by A. Morbidelli) in Deeg and Belmonte, Handbook of Exoplanets, 2nd edition, 2025, Springer Nature Switzerland AG, reproduced with permission of Springer Nature Switzerland AGInternational audiencePlanetary systems can evolve dynamically even after the planets themselves have fully formed, and there is circumstantial evidence that most planetary systems become unstable after the disappearance of the gaseous protoplanetary disk. Theories of planet formation predict that chains of mean-motion resonances are the natural outcome of disk-driven planet migration, leading to the pile up of super-Earth resonant chains close to the inner edge of the disk and the formation of fragile chains for distant giant planets. Observations of young systems suggest that they are more often locked in these chains than older ones, which are instead mostly nonresonant. The instabilities thought responsible for this trend can arise intrinsically if the original systems are too closely packed or be due to external perturbations such as tides, planetesimal scattering, or torques from distant stellar companions. The solar system was not exceptional in this sense, as the outer giants saw the disruption of a resonant chain; meanwhile, the inner system was likely built through a series of giant impacts between closely packed planetary embryos. Thus, the orbital distributions of planetary systems that is observed today, both solar and extrasolar, can be different from those emerging from formation and assembly processes within the disk, and it is important to consider possible long-term dynamics to connect the two
Nuclear translocation of the LINE-1 encoded ORF1 protein alters nuclear envelope integrity in human neurons
No full textInternational audienceLINE-1 retrotransposons are increasingly implicated in aging and neurodegenerative diseases, yet the precise pathogenic mechanisms remain elusive. While the endonuclease and reverse transcriptase activities of LINE-1encoded ORF2p can induce DNA damage and inflammation, a role of LINE-1 ORF1p in cellular dysfunctions stays unassigned. Here we demonstrate, using a neuronal cellular model, that ORF1p translocates into the nucleus upon arsenite-induced stress, directly interacting with nuclear import (KPNB1), nuclear pore complex (NUP153), and nuclear lamina (Lamin B1) proteins. Nuclear translocation of ORF1p disrupts nuclear integrity, nucleocytoplasmic transport, and heterochromatin structure, features linked to neurodegeneration and aging. Elevated nuclear ORF1p levels induced either by arsenite-induced stress, ORF1p overexpression, or as observed in Parkinson's disease post-mortem brain tissues correlate with impaired nuclear envelope (NE) morphology. Stress-induced nuclear alterations are mitigated by blocking ORF1p nuclear import or with the anti-aging drug remodelin. This study thus reveals a pathogenic action of nuclear ORF1p in human neurons driving NE alterations and thereby contributing to LINE-1-mediated cell toxicity
Les Nuées des Bénédictions, formant l'Induction de la Sagesse (Byin rlabs sprin phung ye shes 'bebs pa)
No full textInborn errors of immunity: manifestation, treatment, and outcome – an ESID registry 1994-2024 report on 30,628 patients
No full textInternational audienceAbstract The European Society for Immunodeficiencies patient registry (ESID-R), established in 1994, is one of the world’s largest databases on inborn errors of immunity (IEI). IEI are genetic disorders predisposing patients to infections, autoimmunity, inflammation, allergies and malignancies. Treatments include antimicrobial therapy, immunoglobulin replacement, immune modulation, stem cell transplantation and gene therapy. Data from 194 centers in 33 countries capture clinical manifestations and treatments from birth onward, with annually expected updates. This report reviews the ESID-R’s structure, data content, and impact. The registry includes 30,628 patient datasets (aged 0–97.9 years; median follow-up: 7.2 years; total 825,568.2 patient-years), with 13,550 cases in 15 sub-studies. It has produced 84 peer-reviewed publications (mean citation rate: 95). Findings include real-world observations of IEI diagnoses, genetic causes, clinical manifestations, treatments, and survival trends. The ESID-R fosters global collaboration, advancing IEI research and patient care. This report highlights the key role of the multi-national ESID-R, led by an independent medical society, in evidence-based discovery. Summary Worldwide, most patient registries for inborn errors of immunity are national, with limited geographical and temporal scope. This 30-year ESID registry analysis of 30,628 patients’ longitudinal datasets enables robust epidemiological studies on natural disease courses including diagnosis, treatment, and survival, supporting expanded newborn screening and future AI applications in IEI research
Papyrologie grecque
No full textInternational audienceProgramme de l’année 2023-2024 : I. Initiation à l’édition et à la critique textuelle des papyrus. — II. Étude de papyrus inédits