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Core skills of digital literacies: Constants in an ever-changing literacy landscape
No full textInternational audienc
Extended linearity in the high-order wavefront sensor for the Roman Coronagraph
No full textInternational audienceContext. The aim of the Coronagraphic Instrument (CGI) on board the Roman Space Telescope is to achieve unprecedented levels of contrast for the direct imaging of exoplanets, which will serve as a critical technology demonstrator for future missions such as the Habitable Worlds Observatory (HWO). Achieving these goals requires advanced wavefront sensing and control (WFS&C) strategies, including the use of pair-wise (PW) probing to estimate the electric field in the focal plane. The optimization of PW probe designs is vital in order to enhance performance and reduce operational overhead.Aims. In this study we investigate the performance of different PW probe designs in the context of Roman CGI. Specifically, we compared the classic sinc-sinc-sine probes, previously introduced single-actuator probes, and newly proposed sharp sinc probes in terms of their effectiveness in focal-plane modulation, resilience to nonlinearities at high probe amplitudes, and overall impact on the convergence and contrast levels achieved in laboratory demonstrations.Methods. We conducted experiments on the THD2 testbed, configured to simulate Roman CGI with a custom-made Hybrid Lyot Coronagraph (HLC). We evaluated the three probe designs through closed-loop WFS&C experiments using PW probing for electric field estimation and electric field conjugation (EFC) for wavefront correction. Simulations and hardware tests assessed the contrast convergence and the impact of nonlinear terms at varying probe amplitudes. We also explored low-flux scenarios to demonstrate the effectiveness of high-amplitude probes in reducing exposure times or closing the loop on faint targets.Results. Single-actuator probes emerged as the most effective design, offering faster convergence and reduced susceptibility to nonlinear effects at high amplitudes compared to sinc-sinc-sine probes. Sharp sinc probes perform moderately well, but are less robust than single-actuator probes. High-amplitude single-actuator probes demonstrate advantages in DH digging under low-flux conditions, achieving faster iterations without significant degradation in contrast performance. The THD2 testbed, operating in a contrast regime analogous to Roman CGI, validated these results and underscored its role as a critical platform for advancing WFS&C techniques
ALMA-IMF: XVIII. The assembly of a star cluster: Dense N<SUB>2</SUB>H<SUP>+</SUP> (1–0) kinematics in the massive G351.77 protocluster
No full textInternational audienceALMA-IMF observed 15 massive protoclusters capturing multiple spectral lines and the continuum emission. Here, we focus on the massive protocluster G351.77 (~2500 M⊙, estimated from single-dish continuum observations) located at 2 kpc. We trace the dense gas emission and kinematics with N2H+ (1–0) at ~4 kau resolution. We estimate an N2H+ relative abundance of ~(1.66 ± 0.46) × 10‑10. We decompose the N2H+ emission into up to two velocity components, highlighting the kinematic complexity in the dense gas. By examining the position-velocity (PV) and position-position-velocity (PPV) diagrams on small scales, we observe clear inflow signatures (V-shapes) associated with 1.3 mm cores. The most prominent V-shape has a mass inflow rate of ~13.45 × 10‑4 M⊙ yr‑1 and a short timescale of ~11.42 kyr. We also observe V-shapes without associated cores. This suggests both that cores or centers of accretion exist below the 1.3 mm detection limit, and that the V-shapes may be viable tracers of very early accretion and star formation on ~4 kau scales. The large-scale PV diagram shows that the protocluster is separated into two principal velocity structures separate by ~2 km s‑1. Combined with smaller-scale DCN and H2CO emission in the center, we propose a scenario of larger-scale slow contraction with rotation in the center based on simple toy models. This scenario is consistent with previous lines of evidence, and leads to the new suggestion of outside-in evolution of the protocluster as it collapses. The gas depletion times implied by the V-shapes are short (~0.3 Myr), requiring either very fast cluster formation, and/or continuous mass feeding of the protocluster. The latter is possible via the Mother Filament that G351.77 is forming out of. The remarkable similarities in the properties of G351.77 and the recently published work in G353.41 indicate that many of the physical conditions inferred via the ALMA-IMF N2H+ observations may be generic to protoclusters
Robots sociaux : Explorer de nouvelles formes d'interaction auprès d'enfants avec Trouble du spectre de l'autisme (TSA)
No full textInternational audienceLes robots dit sociaux sont utilisés depuis de nombreuses années comme objets de médiation entre soignants et enfants avec Trouble du spectre de l’autisme (TSA). De multiples études ont démontré que ces outils de médiation améliorent l’engagement et font émerger de nouveaux comportements sociaux chez les enfants ayant un TSA (Chung et al. 2024). Les interactions avec les robots sont généralement préférées du fait de la simplicité des signaux sociaux qu’ils émettent et de leur comportement prédictible. Cependant, la plupart ont été conçus en laboratoire puis évalués sur de petits échantillons et sur un temps limité (Pinto-Bernal et al. 2023). Peu d’études cherchent à intégrer le robot dans un cadre existant ou à évaluer son impact en situation clinique. Enfin, même avec des études longitudinales, les résultats ne prouvent pas systématiquement la capacité à généraliser les compétences acquises à d’autres contextes ou environnements (Diehl et al., 2013). Les études portant sur la médiation robotique auprès des enfants avec TSA montrent un manque de consensus concernant la forme, l’apparence physique que doit prendre un robot social (humanoïde, zoomorphe ou non-anthropomorphe). Une tendance à l’anthropomorphisme existe, qui peut s’expliquer par les attentes liées aux représentations collectives que nous avons des robots sociaux. La forme humanoïde à est généralement décrite comme favorisant l’acceptation d’un robot, mais peut aussi provoquer un sentiment de rejet ou d’inconfort (Mori, 1970) chez certains enfants et professionnels de santé. Cela peut être dû à la surcharge sensorielle ou aux attentes élevées liées à l’apparence humaine (Dubois-Sage et al., 2024). Si nous possédons la capacité innée à attribuer des traits anthropomorphes à n’importe quel objet, la ressemblance à l’humain n’est peut-être pas le critère principal favorisant ce phénomène (Airenti, 2012). L’anthropomorphisme est plutôt une relation que nous établissons avec un objet ou un animal, en lui attribuant des intentions pour donner du sens à ses actions. Ainsi, Jastrazab et al. proposent que les robots ayant des comportements sociaux, comme des facultés à communiquer ou à coopérer, sont jugés plus susceptibles de se voir prêter des états mentaux, et ce même s’ils ne ressemblent pas physiquement à des humains. Le fait que l’objet ait une apparence non anthropomorphe n’est absolument pas un obstacle à l’anthropomorphisation de cet objet. Ceci rejoint les travaux de Bianchini et al. (2014) sur les objets à comportement et nous encourage à explorer de nouvelles formes comportementales d’anthropomorphisme. Pour ce faire, nous comptons mener une étude afin d’élaborer un objet robotisé en nous intéressant directement au travail de terrain réalisé par les soignants. Le but est de concevoir un outil pouvant répondre à un besoin spécifique et qui sera donc moins généraliste que la plupart des robots utilisés actuellement. En collaboration avec un centre d’accueil d’enfants ayant un trouble du spectre de l’autisme, la mutuelle La Mayotte, nous visons la création d’un objet qui puisse être utilisé à la fois par les soignants et les parents. À rebours de la robotique thérapeutique développée actuellement, l’enjeu de cette collaboration est de créer un objet facilement utilisable par les éducateurs et peu coûteux, autant financièrement que du point de vue environnemental. Cet objet comportemental proposera une forme non-anthropomorphe avec comme hypothèse qu’un comportement social est plus important que des critères physiques pour créer une interaction avec l’enfant (Jastrazab et al. 2024). En effet, une personne qui interagit avec un robot est d’abord frappée par son apparence physique (Scassellati et al. 2012). Afin de limiter les attentes d’interactions et focaliser l’attention sur le comportement de l’objet robotisé et non son design, il est donc important d’explorer des formes de design plus abstraites, qui véhiculent moins d’attentes
Surveying the Whirlpool at Arcseconds with NOEMA (SWAN): II. Survey design and observations
No full textInternational audienceWe present Surveying the Whirlpool at Arcseconds with NOEMA (SWAN), a high-resolution, high-sensitivity survey to map molecular lines in the 3 mm band in M51 (the Whirlpool galaxy). SWAN has obtained the largest high-sensitivity map (∼5 × 7 kpc2) of N2H+ emission at ∼cloud-scale resolution (3″ ∼ 125 pc) in an external galaxy to date. Here, we describe the observations and data reduction of ∼214 hours of interferometric data from the Northern Extended Millimetre Array (NOEMA) and ∼55 hours of tailored new observations with the 30m telescope of the Institut de radioastronomie millimétrique (IRAM), as well as the combination of these NOEMA and new IRAM-30m observations with ∼14 hours of archival IRAM-30m observations. We detect widespread emission from nine molecular transition lines. The J = 1 ‑ 0 transitions of the CO isotopologs 13CO and C18O are detected at high significance across the full observed field of view (FoV). HCN(1‑0), HNC(1‑0), HCO+(1‑0), and N2H+(1‑0) are detected in the center, molecular ring, and spiral arms of the galaxy, while the shock tracer HNCO(4‑3) and (5‑4) and PDR tracer C2H(1‑0) are detected in the central ∼1 kpc and molecular ring only. For most of the lines that we detect, average line ratios with respect to 12CO are increased by up to a factor of ∼3 in the central 1 kpc, where an active galactic nucleus and its low-inclination outflow are present, compared to the disk. Line ratios between CO isotopologs show less variation across the SWAN FoV. Across the full SWAN FoV, 13CO, C18O, HCN, HNC, HCO+ and N2H+ are 8±22, 29±76, 17±35, 37±510, 26±53 and 63±3810 times fainter than 12CO, respectively, in pixels where each line is significantly detected. Although we observe variations in line ratios between larger-scale environments like the center and disk of M51, the scatter within each environment also indicates the influence of smaller-scale processes. The ability to measure these effects is only possible thanks to the high resolution and high sensitivity of the SWAN dataset across multiple environments. This provides the sharpest view of these molecular transitions over the largest physical area ever captured in an external galaxy
A two-sector model of healthcare provision with directed search
No full textForthcoming in Theory and Decision (2025)In France, specialist physicians providing outpatient care work either in sector 1, where fees are regulated, or sector 2, where they set their own fees freely. Patients choose their physician based on fees, perceived quality of service and the likelihood of obtaining an appointment, directing their search toward either sector 1 or sector 2 providers. In equilibrium, significant patient and physician mobility across sectors means that policies affecting one sector have spillover effects on the other. We use comparative statics to analyze the consequences of various policies, such as increasing regulated fees or expanding private insurance coverage for sector 2 consultations. Both entail a positive response of the unregulated fee in sector 2. Some effects are counterintuitive and result from the reallocation of patients and physicians across sectors, which can deteriorate the effectiveness of the search process
Simulation of wave propagation in rock samples during fluid substitution using full-wave modeling
No full textInternational audienceA new full-wave simulation of wave propagation at the scale of laboratory samples is presented.The objective is to provide a tool to better understand the complex interplay between different waves propagating in rock samples during fluid substitution processes. The model is based on a 3D finite difference scheme used to solve the elasto-dynamic equation in cylinders of porous rock with an isotropic visco-elastic rheology. The general idea is to simulate real lab experiments for which the outcome of the modeling can be compared to real data. Two examples of application are presented. Case study 1 corresponds to the simulation of an oil injection experiment in a dry chalk sample: although a first-order agreement was found, the model failed in reproducing the complexity of the recorded signals, due to the lack of knowledge of the oil saturation profile through time. Case study 2 is a water injection test in another dry chalk sample: in this experiment, the evolution in space and time of the water saturation profile could be estimated, and the numerical modeling results were successful in matching the experimental observations with few discrepancies. The new modeling tool can be used to help the interpretation of complex recorded signals resulting from wave interference, and also to improve the rock physics model in changing environments like in 4D seismic, where fluid substitution processes are at play.</div
Versatile light curve templates of Cepheids: Multi-band fitting of photometric time series
No full textInternational audienceContext. To use the period–luminosity relations of Cepheids to derive distances of extragalactic Cepheids, it is crucial to have reliable estimations of the luminosity of such stars. However, the light curves (LCs) of extragalactic Cepheids are sparsely sampled, which makes the interpolation difficult.Aims. Our purpose is to create general templates of Cepheid LCs that can be efficiently applied with only a few parameters, while ensuring they are reliable in terms of resulting mean magnitudes. We have also aimed to provide adaptable templates for the large variety of photometric bands to enlarge their possible applications.Methods. We performed a principal component analysis (PCA) on LCs in different bands from the optical to the mid-infrared (MIR) fitted by atmosphere models along the pulsation cycle for 75 galactic Cepheids. All the photometric bands were treated together to incorporate the results of the effective temperature variation. To link the different shapes of LCs, we also derived the relations between the period and the coefficients associated to the PCA.Results. We present our templates and a further analysis to validate their reliability. We also offer an example of their application to one Cepheid in the galaxy NGC 5584. We find a good agreement with previous estimations of mean magnitudes in the HST filters. We show examples of a template fitting for Cepheids in various environments to demonstrate the variety of applications of these templates.Conclusions. The templates we propose here can be used in a number of different situations (good phase coverage in many filters, poor phase coverage in one specific filter, but good phase coverage in some others, or noisy and sparse data), thereby mobilising the adapted fitting strategies. Moreover, the broad adaptability of this LC prediction tool is provided by the multiple photometric bands in which they can be inferred
The (UN)Importance of Inheritance
No full textInternational audienceTransfers from parents—either in the form of gifts or inheritances—have received much attention as a source of inequality. This paper uses administrative data for the population of Norway to examine the share of the Total Inflows (defined as the capitalized sum of net labor income, government transfers, and gifts and inheritances received over the period) accounted for by capitalized gifts and inheritances. Consistent with other work, we find that there is much inequality in the receipt of gifts and inheritances. However, gifts and inheritances represent a small share of Total Inflows; this is true across the distribution of Total Inflows, as well as at all levels of net wealth. Gifts and inheritances are only an important source of income flows among those who have very wealthy parents. Additionally, gifts and inheritances have very little effect on the distribution of Total Inflows, suggesting that inheritance taxes may do little to mitigate inequality
Nanopore sensing of protein and peptide conformation for point-of-care applications
No full textInternational audienceThe global population’s aging and growth will likely result in an increase in chronic aging-related diseases. Early diagnosis could improve the medical care and quality of life. Many diseases are linked to misfolding or conformational changes in biomarker peptides and proteins, which affect their function and binding properties. Current clinical methods struggle to detect and quantify these changes. Therefore, there is a need for sensitive conformational sensors that can detect low-concentration analytes in biofluids. Nanopore electrical detection has shown potential in sensing subtle protein and peptide conformation changes. This technique can detect single molecules label-free while distinguishing shape or physicochemical property changes. Its proven sensitivity makes nanopore sensing technology promising for ultra-sensitive, personalized point-of-care devices. We focus on the capability of nanopore sensing for detecting and quantifying conformational modifications and enantiomers in biomarker proteins and peptides and discuss this technology as a solution to future societal health challenges