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Geometric Reasoning and Perception in Typical and Atypical Motor Development: Preliminary Results
No full textInternational audienceThis study explores geometric reasoning and perception in children with and without Developmental Coordination Disorder (DCD) using an odd-one-out task across three categories: metric properties, Euclidean geometry, and geometric shapes.Preliminary results reveal lower accuracy in DCD children for metric and Euclidean stimuli (p = .004 and p = .028), while reasoning performance—logical, pragmatic, and error rates—remains comparable between groups. Age and motor abilities emerged as significant predictors of task performance.Despite reduced visuomotor precision, children with DCD demonstrated preserved conceptual reasoning, suggesting that cognitive resources for geometry remain accessible if motor demands are reduced. These findings support the development of adapted educational strategies that rely less on manipulation and more on abstract reasoning.This promising evidence highlights the need for inclusive digital tools to scaffold learning and foster access to geometry in children with motor difficulties
Efficiency of the Minimum Approval Mechanism With Heterogeneous Players
No full textInternational audienceThe minimum approval mechanism (MAM) was introduced by Masuda et al. ( 2014) as a mechanism aimed at mitigating free riding in the social dilemma context of a public good game. The MAM is a two-stage mechanism which theoretically achieves the socially optimum level of public good provision, according to various equilibrium concepts (e.g., backward elimination of weakly dominated strategies, level-k, or minimax regret). We study the robustness of this mechanism to the introduction of endowment heterogeneity. We explore, theoretically and experimentally, how endowment inequalities affect the effectiveness of the MAM at improving the level of provision. We find that the mechanism is still Pareto-improving under endowment heterogeneity, but that its efficiency diminishes as inequality is increased. Our experimental findings indicate a significant weakening of the mechanism under endowment inequalities, surpassing our theoretical predictions. A close examination of individual behaviors reveals a significant drop in contributions compared to the uniform case, prompted by even minor inequalities. Intriguingly, our findings challenge conventional assumptions by showing that inequality aversion drives contributions in a public good game with endowment disparities only under certain assumptions. We explore the impact of beliefs about the contributions of advantaged players as potential motivations through guilt aversion and Kantian preferences
Earliest evidence for heavy metal pollution on wildlife in Middle Age Europe
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SNX-BAR proteins 5 and 6 are required for NCOA7-AS antiviral activity against influenza A virus
No full textInterferon-induced antiviral proteins act on the first line of defence against viruses, including influenza A virus (IAV). Among those, the short isoform of Nuclear Receptor Coactivator 7 (NCOA7-AS) has been shown to inhibit IAV entry and more especially the fusion between endosomal and viral membranes. Ectopic expression of NCOA7-AS leads to the increased acidification of the endolysosomal pathway, putatively through NCOA7-AS interaction with the vacuolar ATPase (V-ATPase). However, the precise mechanism of action of NCOA7-AS is not fully understood. Here, we identified the cellular partners of NCOA7-AS by mass spectrometry, including the V-ATPase subunits known to interact with NCOA7-AS. Mutation of NCOA7-AS glycine 91 abolished V-ATPase binding and antiviral activity against IAV, confirming the role of the V-ATPase in the antiviral phenotype. Moreover, sorting nexin (SNX) 1/2/5/6 were identified as novel partners of NCOA7-AS. These proteins are involved in retrograde transport of cellular cargoes from endosomes to the trans-Golgi network. We revealed that SNX5/6 were essential for NCOA7-AS antiviral activity against IAV and interacted directly with NCOA7-AS. Interestingly, crystal structures of NCOA7-AS/SNX5 complexes showed that the SNX5-interaction motif in NCOA7-AS was similar to those found in known cargoes of SNX5/6. In addition, we could pinpoint several critical residues that were important for binding and antiviral activity. Collectively, our study identifies novel essential partners for NCOA7-AS antiviral activity and the structural basis for their interaction.</div
Calibration géometrique d'un réseau d'antennes microphiniques
No full textInternational audienceUn réseau de cinq antennes sphériques de microphones est déployé sur un périmètre d'une dizaine de mètres, afin de détecter et localiser des sources acoustiques dans un espace tridimensionnel. Pour garantir une certaine précision lors de ce processus de localisation, il est nécessaire de connaître avec exactitude la position des antennes les unes par rapport aux autres. Or, l'idée étant de déployer ce réseau en extérieur et sur des terrains qui ne sont pas nécessairement plats, les outils métrologiques ne sont pas suffisants. L'objectif de cette étude est de calibrer géométriquement ce réseau d'antennes, en exploitant les différences de temps de vol entre un certain nombre de sources de bruit environnantes, et chacun des microphones du réseau. On utilise une méthode robuste de calibration géométrique de grandes antennes [1] avec un traitement spécifique pour l'adapter à une configuration de réseaux de petites antennes distribuées. L'approche proposée et validée par simulations, puis expérimentalement en chambre semi-anéchoique
Quel travail de territorialisation de la politique PTCE ? Une mise en perspective sur 3 territoires
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Un art maussien du penser (demander, donner, recevoir, rendre). Autour de l’œuvre de Michel Fabre
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Pattern-Based Graph Classification: Comparison of Quality Measures and Importance of Preprocessing
No full textInternational audienceGraph classification aims to categorize graphs based on their structural and attribute features, with applications in diverse fields such as social network analysis and bioinformatics. Among the methods proposed to solve this task, those relying on patterns (i.e. subgraphs) provide good explainability, as the patterns used for classification can be directly interpreted. To identify meaningful patterns, a standard approach is to use a quality measure, i.e. a function that evaluates the discriminative power of each pattern. However, the literature provides tens of such measures, making it difficult to select the most appropriate for a given application. Only a handful of surveys try to provide some insight by comparing these measures, and none of them specifically focuses on graphs. This typically results in the systematic use of the most widespread measures, without thorough evaluation. To address this issue, we present a comparative analysis of 38 quality measures from the literature. We characterize them theoretically, based on four mathematical properties. We leverage publicly available datasets to constitute a benchmark, and propose a method to elaborate a gold standard ranking of the patterns. We exploit these resources to perform an empirical comparison of the measures, both in terms of pattern ranking and classification performance. Moreover, we propose a clustering-based preprocessing step, which groups patterns appearing in the same graphs to enhance classification performance. Our experimental results demonstrate the effectiveness of this step, reducing the number of patterns to be processed while achieving comparable performance. Additionally, we show that some popular measures widely used in the literature are not associated with the best results
Experimental tests of the calibration of high precision differential astrometry for exoplanets
No full textInternational audienceHigh precision differential Astrometry is the branch of astronomy that evaluates the relative position, distance and motion of celestial objects with respect to the stars present in the field of view. A mission called Theia has been submitted in 2022 for ESA's M7 call for missions, using a diffraction-limited telescope about 1m in diameter and with a field of view of 0.5 degrees, capable of achieving sub-micro-arcsecond angular accuracy, corresponding to 1e-5 pixel on the detector. Such precision makes it possible to study the nature of dark matter in our galaxy and to reveal the architecture of exoplanetary systems close to the Sun, down to the mass of the Earth. The aim of the experimental tests is to improve the TRL of 2 specific aspects: the calibration of new CMOS detectors with very large number of pixels and the calibration of the telescope aberrations.First, a key element of such a space telescope is the focal plane, which must be calibrated spatially with an extreme precision down to the 1e-5 pixel level. Previous work has shown that this is possible with small detector matrices (80x80 px). The goal is now to check the performances and validate this method with the new very large detectors. Pyxalis, a company based near Grenoble, is developing very large detectors (8000x5000 px) that have a low noise level and high sensitivity. The aim is to characterize and validate this type of detectors in a laboratory demonstration, to ensure that the performance achieved meets the required specifications. We present the results of these characterization in this contribution.The telescope stability is also a sensitive issue. Recent work has shown that the reference stars in the field of the telescope can be used as actual metrology sources in order to compute the field distortion function. Our simulations allow to model the optical aberrations with bivariate polynoms. The effects on the calibration accuracy of the degrees of the polynoms, the number of reference stars and the tilt perturbation of the M2 mirror are investigated. This paper will present the latest results obtained on a test bed developed to experimentally study the performances of this new field calibration method