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Gallica-Obvie: un outil pour la valorisation et l'exploration du patrimoine textuel
No full textInternational audienceAvec ses 10 millions de documents, Gallica, la bibliothèque numérique de la Bibliothèque nationale de France (BnF), figure parmi les collections en ligne les plus vastes au monde. Enrichie d'outils d'analyse et de fouille textuelle, elle offre aux chercheurs en sciences humaines et sociales des perspectives inestimables pour explorer et interroger des corpus patrimoniaux dans un environnement numérique.Nous présentons Gallica-Obvie, un nouveau prototype permettant de connecter Gallica 1 à la plateforme Obvie 2 , un moteur de recherche doté de fonctionnalités avancées pour la fouille de textes, les statistiques lexicales et la comparaison de corpus. Gallica-Obvie permet aux chercheurs d'importer directement des documents depuis Gallica grâce à leurs identifiants ARK (Archival Resource Key). Une fois importés, ces documents sont automatiquement intégrés dans Obvie, où ils peuvent être indexés et analysés.Le processus, illustré par ce diagramme simplifié, commence par la saisie d'une liste de liens ARK dans l'interface utilisateur. L'outil interroge alors l'API de Gallica pour récupérer les documents demandés. Ces derniers sont transférés vers Obvie, où une instance temporaire du corpus est créée, immédiatement accessible en ligne. Cette instance offre une gamme d'outils d'analyse, notamment des recherches par mots clés lemmatisés, un filtrage précis par métadonnées, des concordances, des comparaisons inter-corpus et des visualisations interactive
Development of a flight simulator for the WEST plasma and control system
No full textInternational audienceThe ITER project (www.iter.org) should demonstrate in the next decades the technical feasibility of controlled fusion reactions in tokamaks. One of the critical issues reaching this purpose is the design of plasma scenarios and associated controllers in order to achieve the desired performance while satisfying the operational limits. To succeed, the non-linearity, the uncertainties, and the limited observability of the plasma presently require adjusting controllers and scenarios during commissioning sessions. This method is time-consuming and must be reduced to the strict minimum time. To address this issue, the community has developed for several years simulation tools to design both controllers and scenarios using numerical models of the plasma. From simple linear models of the vertical plasma instability to integrated modeling of both plasma transport and equilibrium, these codes are now efficient enough to predict the plasma behavior and be called “flight simulator”. In this article, the flight simulator developed for WEST will be presented. One of the main features is the use as input of the same pulse schedule files and the same controllers as in the WEST Plasma Control System (PCS). Based on the free boundary equilibrium code NICE with flux diffusion equation and a 1D transport model, a consistent plasma time evolution can be computed and reduces the risk of failure due to numerical issues. To illustrate the abilities of the tool, a standard WEST X-point formation will be simulated and compared to the real data
Anomalous self-diffusion in tungsten and molybdenum: Exonerating the di-vacancy contribution and the key role of interatomic interaction
No full textInternational audienceThis study completes the long-standing effort to understand experimental measurements of self-diffusion in body-centered cubic (bcc) metals. Over the past decade, a growing consensus has emerged regarding the attribution of the anomalous non-Arrhenius behavior to the anharmonicity of atomic interactions. This work advances the understanding of two fundamental issues: (i) the free energy contributions from small vacancy clusters are quantitatively accounted for, leading to the conclusion that the di-vacancy contribution is negligible; and (ii) quantitative agreement between theory and experiment can only be achieved when employing interatomic interactions of a quality beyond standard exchange-correlation functionals, such as those provided by recent meta-generalized gradient approximations (meta-GGAs). The present conclusions are made possible thanks to an accurate characterization of the free energy landscape of metals that goes beyond the perfect bulk and simple defects, such as mono-vacancies. Moreover, the present treatment is able to provide the free energy landscape not only for the absolute minimum of defect configurations, but also for other local minima. These achievements make use of advanced Bayesian sampling techniques applied to the calculation of the formation free energy and the optimal solution through averaged force projection for migration free energy, utilizing high-precision, data-driven force fields at ab initio accuracy. We emphasize the importance of atomic interactions, as produced by the exchange-correlation functional underlying the data-driven force fields, by investigating two machine-learning potentials constructed using standard GGAs. Corrections to formation energies at zero temperature, arising from differences between the standard GGA and a recent meta-GGA functional, are shown to be the primary source of discrepancies between theoretical predictions and experimental values. The workflow developed in this study paves the way for the comprehensive study of diffusion in materials and enables automated, systematic investigations of complex energetic landscapes
Overlapping upstream ORFs ending at c.125 lead to reduced Endoglin, contributing to Hereditary Hemorrhagic Telangiectasia
No full textInternational audienceAbstract Hereditary Hemorrhagic Telangiectasia (HHT) is a rare vascular disease mainly caused by pathogenic mutations in ACVRL1 and ENG genes. Despite advances in HHT diagnosis, the molecular origin of some cases remains unclear. Recently, we observed a high prevalence of HHT-causing 5’UTR variants in ENG . These variants commonly introduce upstream AUG codons (uAUGs) at the origin of upstream open reading frames (upORFs) overlapping the coding sequence, all terminating at the same stop codon located at position c.125 (uAUG-c.125). Here, we analyzed all 5’UTR ENG single nucleotide variants that could alter upORFs in silico. Interestingly, we found that 85% of uAUG-c.125 variants alter the protein levels. Furthermore, we identified 2 variants creating uAUG-c.125 and uCUG-c.125 in HHT patients and experimentally demonstrated their association with reduced endoglin levels This study provides new elements for the interpretation of upORF-altering variants in the 5’UTR of ENG with new insights for the molecular diagnosis of HHT
Development of a functional assay for the characterisation of SMAD4 variants from the French haemorrhagic hereditary telangiectasia cohort
No full textInternational audienceBackground: Hereditary haemorrhagic telangiectasia (HHT) and juvenile polyposis syndrome (JPS) can be caused by SMAD4 pathogenic variants. SMAD4 is a common transcription factor of the BMP/TGFβ signalling pathway. In this study, we developed a cell-based functional assay to address the pathogenicity of SMAD4 variants identified in the French HHT cohort.Methods: SMAD4 variants were generated by site-directed mutagenesis. A functional assay was developed in a cell line that does not express SMAD4, and the different SMAD4 variants were tested for their capacity to activate the BMP and TGFβ response using luciferase reporter assays.Results: Twelve SMAD4 variants were identified and studied. We were able to develop a robust functional assay for these variants. All the expressed variants resulted in loss of function (LOF) in response to BMP9 or TGFβ1 stimulation. SMAD4 variants within the MH2 domain expressed SMAD4 mutated proteins that were unable to hetero-oligomerise with other SMADs, which could explain their LOF. Finally, we tested primary human endothelial cells isolated from patients with HHT carrying SMAD4 heterozygous pathogenic variants and observed that they behaved like the control cells at rest or when stimulated with BMP9.Conclusion: We developed a SMAD4 functional assay that allows discrimination between benign and pathogenic SMAD4 variants. We demonstrated that the underlying molecular mechanism of this pathogenicity is due mostly to a loss of hetero-oligomerisation. This assay will be transferable to clinical genetic laboratories and will improve the diagnosis of patients with HHT–JPS
WS segregation in W-doped NaPS sodium solid electrolyte
No full textInternational audienceBatteries are crucial for addressing global warming, but their reliance on depleting lithium resources is concerning. Sodium-based batteries have emerged as promising alternatives for next-generation solid-state batteries. To improve electrolyte performance, particularly ionic conductivity, scientists have explored aliovalent substitution strategies for archetypal materials like Na3PS4 (NPS). An approach introduces W6+ ions at the 2a (0,0,0) Wyckoff site in place of P5+ in NPS, creating WS4²⁻ tetrahedra and Na vacancies in the Na3-xP1-xWxS4 (NPWS) thiophosphates that enhance ionic mobility. However, X-ray diffraction shows segregation of WS2, indicating limited solubility.[1,2] Unit cell parameters change minimally with increasing W content, with maximum reported values of x = 0.1[1] to 0.15[2] without significant unreacted WS2. In some cases, improved ionic conductivity (σion, up to 1.3 × 10⁻² S cm⁻¹) appears to be the result of changes in the NPS phase during heat treatment rather than W6+ incorporation.[2] We explored NPWS (x = 0.15) by using neutron (NPD) and synchrotron X-ray (SXRD) powder thermodiffraction to understand the phases transition during heat treatment
Quenched properties of the Spectral Form Factor
No full textInternational audienceThe Spectral Form Factor (SFF) is defined as the modulus squared of the partition function in complex temperature for hermitian matrices and a suitable generalisation has been given in the non hermitian case. In this work we compute the properties of the quenched SFF for hermitian and non hermitian random matrices. Despite the fact that the (annealed) SFF is not self-averaging the quenched SFF is self-averaging but these two averages coincide up to subleading constants (at least for high enough temperatures). The fluctuations of are deep and one encounters thin spikes when moving close to a zero of the partition function. We study the partition function at late times by considering a suitable change of variable which turns out to be compatible with a Gumbel distribution. We note that the exponential tails of this distribution can be obtained by the deep spikes in the , namely the zeros of the partition function. We compare with the results obtained in isolated many-body systems and we show that same results hold at late times also for non-hermitian Hamiltonains and non-hermitian random matrices
Recovering unbiased CMB polarization maps using modern ground-based experiments with minimal assumptions about atmospheric emission
No full textInternational audienceWe present a study of unbiased reconstruction of cosmic microwave background (CMB) polarization maps from data collected by modern ground-based observatories. Atmospheric emission is a major source of correlated noise in such experiments, complicating the recovery of faint cosmological signals. We consider estimators that require minimal assumptions about unpolarized atmospheric emission properties, instead exploiting hardware solutions commonly implemented in modern instruments, such as pairs of orthogonal antennas in each focal plane pixel, and polarization signal modulation via a continuously rotating half-wave plate (HWP). We focus on two techniques: (i) statistical down-weighting of low-frequency atmospheric signals, and (ii) pair-differencing (PD), which involves differencing signals collected by two detectors in the same focal plane pixel. We compare their performance against the idealized case where the atmospheric signal is perfectly known and cleanly subtracted. We show that PD can be derived from maximum likelihood principles under general assumptions about the atmospheric signal, optimizing map sensitivity. In the absence of instrumental systematics but with reasonable detector noise variations, PD yields polarized sky maps with noise levels only slightly worse than the ideal case. While down-weighting could match this performance, it requires highly accurate atmospheric models that are not readily available. PD performance is affected by instrumental systematics, particularly those leaking atmospheric signal to the difference time stream. However, effects like gain mismatch are efficiently mitigated by a rotating HWP, making PD a competitive, robust, and efficient solution for CMB polarization mapmaking without atmospheric modeling
The Bigfoot: A footprint of a Coma cluster progenitor at z=3.98
No full textInternational audienceProtoclusters, galaxy clusters' high redshift progenitors, hold the keys to understanding the formation and evolution of clusters and their member galaxies. However, their cosmological distances and spatial extensions (tens of Mpc) have inhibited complete mapping of their structure and constituent galaxies, which is key to robustly linking protoclusters to their descendants. Here we report the discovery of the Bigfoot, a tridimensional structure at including 11 subgroups traced by 55 (700) spectroscopic (photometric) redshifts with JWST, extending over in the PRIMER-UDS field. Bigfoot's large-scale and mass function of member galaxies closely match constrained simulations' predictions for the progenitors of today's most massive clusters (). All subgroups with exhibit enhanced fractions of massive galaxies () compared to lower-mass halos and the field, demonstrating the accelerated formation of massive galaxies in massive halos. The presence of this massive protocluster with a large central halo () in a JWST deep field bears important cosmological implication that favors high of PLANCK cosmology over low-redshift probes
Measurement of the -boson angular coefficients and transverse momentum in collisions at TeV with the ATLAS detector
No full textInternational audienceThe angular distributions of Drell-Yan lepton pairs provide sensitive probes of the underlying dynamics of quantum chromodynamics (QCD) effects in vector-boson production. This paper presents for the first time the measurement of the full set of angular coefficients together with the differential cross-section as a function of the transverse momentum of the boson, in the full phase space of the decay leptons. The measurements are performed separately for the and channels. The analysis uses proton-proton collision data recorded by the ATLAS experiment at the Large Hadron Collider in 2017 and 2018, during special low-luminosity runs with a reduced number of interactions per bunch crossings (pile-up). The data correspond to an integrated luminosity of pb at a centre-of-mass energy of TeV. The low pile-up conditions enable an optimised reconstruction of the boson transverse momentum. All results agree with theory predictions incorporating finite-order QCD corrections up to next-to-next-to-leading-order in the strong coupling constant,