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The challenges of communicating in a sensitive environment about a sensitive topic
No full textInternational audienceIn this chapter, we present a case study of a project that deals with a politically sensitive and often publicly debated subject: extremism. In developing dissemination practices, we had to take into consideration that the ability or political inclination to receive, understand, and digest academic knowledge from different stakeholders can change due to a polarizing public atmosphere and fluctuating political environment. Hence, we acknowledged that the success of the Analysis of and Responses to Extremist Narratives (ARENAS) project would depend on how we communicate our research results to various audiences (the public and key stakeholders) with their own diverse political affinities, of which we were not neces-sarily aware. Therefore, we developed a strategy for sharing politically loaded content based on several layers of practices for translating academic knowledge to different contexts simultaneously. In this study, we discuss what kind of flexibility and reactivity proved to be inevitable in the process of recalibrating and continuously recontextualizing academic knowledge in order to meet the shifting expectations of multiple audiences
Better safe than sorry: discriminability and response bias in adult food neophobia
No full textInternational audienceFood neophobia, the reluctance to try novel or unfamiliar foods, is thought to involve both uncertainty-related processes and avoidance tendencies under perceived risk. These components have largely been studied separately. This study integrates both using the Signal Detection Theory framework to examine how adults decide whether a food item is edible or inedible under conditions of uncertainty and risk. 57 young French adults (32 females; M = 20.9 years, SD = 4.23) completed validated measures of food neophobia and food disgust sensitivity, and performed a Go/no-Go task in which familiar and unfamiliar foods, presented with or without visual cues of spoilage. Results showed that higher levels of food neophobia were associated with poorer discriminability in distinguishing safe from unsafe food. Individuals with higher food neophobia also exhibited a cautious response bias, favoring "inedible" responses even at the cost of missing edible items, particularly unfamiliar foods. These findings extend previous research in children, highlighting the importance of considering both components to fully understand food neophobia in adults. Interventions aiming to increase acceptance of healthier or more sustainable foods, perceived as new by consumers, should address both reduced discriminability and cautious response tendencies
Influence of Fe-Rich Materials on the Evolution of Amino Acids under Asteroidal Aqueous Alteration
No full textInternational audienceAmino acids have been detected in carbonaceous chondrites, with abundances and isotopic compositions varying significantly between different meteorites as well as within individual meteorites. In this study, we assessed whether the presence and abundance of Fe-rich phases during parent body alteration can account for observed variations in amino acid concentrations and isotope composition. To test this, we examined the chemical and 13C-isotopic signatures of six amino acids–glycine, β-alanine, α-alanine, 2-aminoisobutyric acid, γ-aminobutyric acid, and isovaline–following experimental exposure to hydrothermal conditions (150°C, 10 days) in the presence or absence of Fe-bearing materials (Fe, Fe2O3, FeS2). In the absence of Fe-rich materials, glycine and α-alanine rather withstood hydrothermal conditions, consistently with abundances reported for carbonaceous chondrites having experienced various degrees of aqueous alteration. In contrast, upon exposure to similar hydrothermal conditions, the degradation of β-alanine produced a new compound, possibly 3-aminoadipic acid, via the recombination of products of its decarboxylation and deamination, while more than 95% of γ-aminobutyric acid was converted to 2-pyrrolidone through self-cyclization. The presence of Fe-rich materials inhibited the destruction of β-alanine, 2-aminoisobutyric acid, and γ-aminobutyric acid. Fe2O3 promoted the conversion of glycine into aspartic acid, and the resulting organics interacted with Fe2O3, leading to a relatively higher organic content in the residues compared to other Fe-containing materials after the experiments. Oxides in CI chondrites may exhibit variable effects on each amino acid compound during aqueous alteration, potentially explaining the higher β-Alanine/Glycine ratios observed compared with CM chondrites. The slight changes in δ13C values of amino acids upon exposure to hydrothermal conditions, independent of the presence or absence of Fe-rich materials, could not account for the variations observed in the δ13C values of chondritic amino acids. Hence, the δ13C values of amino acids reported in CR and CM chondrites may be inherited from the preaccretion processes
En quête d'un citoyen moderne. L'enseignement moral et civique entre rénovation et précarisation
No full textInternational audienceBy studying the implementation of a renewed moral and civic education program in French schools from 2015 onwards, this book aims to shed light on the multiple conditions - political, institutional, organizational and intellectual - that shape citizenship education in schools. By reconstructing the different levels and logics of the actors involved in citizenship education as an educational policy, it draws inspiration from the sociology of public action, with the aim of bringing together sociology, philosophy, the history of education and subject didactics, through the analyses of researchers from a variety of disciplinary backgrounds. In the following chapters, these analyses attempt to understand the persistent precariousness of moral and civic education. Under what conditions, then, can school education in citizenship contribute to the effective formation of the citizen? What knowledge does the exercise of citizenship require in today's world? To what extent can political education be independent of moral education? Does civic education require specific teaching, or is it dependent on cross-disciplinary learning?At a time when EMC curricula are once again being revised, the question is to explore in detail the possibilities, but also the obstacles and tensions underlying the project to educate for democratic citizenship at school.En étudiant la mise en place dans les établissements scolaires français d’un enseignement moral et civique rénové à partir de 2015, le présent ouvrage s’attache à mettre en lumière les conditions multiples – politiques, institutionnelles, organisationnelles et intellectuelles – qui président à la formation scolaire du citoyen. L’ouvrage s’inspire de la sociologie de l’action publique pour reconstituer les différents niveaux et logiques d’acteurs qui structurent l’éducation à la citoyenneté comme politique éducative. Ce faisant, il propose une approche résolument interdisciplinaire, croisant sociologie, philosophie, histoire de l’éducation et didactiques des disciplines, nourrie par des travaux de chercheurs d’horizons disciplinaires divers.Au fil des chapitres, ces analyses visent à comprendre la précarité persistante de l’enseignement moral et civique. À quelles conditions alors l’éducation scolaire à la citoyenneté peut-elle contribuer à la formation effective du citoyen ? Quels savoirs l’exercice de la citoyenneté requiert-il dans le monde contemporain ? Dans quelle mesure l’éducation au politique peut-elle s’autonomiser de l’éducation morale ? La formation civique suppose-t-elle un enseignement spécifique ou bien est-elle dépendante d’apprentissages transversaux ? Dans un contexte où les programmes d’EMC sont sujets à de nombreuses réformes, il s’agit ici d’explorer de manière fine les possibles mais aussi les empêchements et les tensions sous-jacentes au projet d’éduquer à la citoyenneté démocratique à l’école
Elastic properties of lacustrine, palustrine, and pedogenic carbonates: petrographic implications and insights from analytical modeling
No full textInternational audienceThe development of lacustrine, palustrine, and pedogenic carbonates through a continuum of sedimentary and diagenetic environments results in highly heterogeneous pore networks, which remain poorly characterized in palustrine and pedogenic facies in terms of their influence on petrophysical properties. These preclude any straightforward correlations between their physical properties and geological characteristics. This study investigates the diversity of elastic properties in fifty Cenozoic lacustrine, palustrine, and pedogenic micritic carbonates of the Paris Basin using samples from three boreholes and ten outcrops. This provides: i) a detailed petrographic framework, ii) ultrasonic measurements of seventy-six 1-inch plugs covering seven facies, and iii) a modeling approach based on the effective medium theory and Gassmann predictions. This study exhibits a broad range of porosities (1.7–40.5%), alongside unusually high P-wave velocities for a given porosity (4.1–6.5 km.s−1). The seven studied facies (wackestones with intraclasts, shell-rich floatstones, wackestones with root traces, peloidal grainstones, in-situ brecciated limestones, laminar limestones, nodular brecciated limestones) cannot be discriminated based on their elastic properties. Nevertheless, palustrine and pedogenic samples have similar properties, and about half of them display higher velocities than lacustrine facies. Nine diagenetic pathways were identified in these shallowly buried facies (maximum depth of ∼ 200m), which synthesize multiple calcite cementation, dissolution, and/or silicification phases, as well as cracks, but do not account for the observed acoustic dispersion. Studied rocks show six dominant pore types: microporosity, microbial framework, gastropod shells or roots moldic pores, root-related framework, and vuggy pores. They are the results of close relationships between depositional environment and diagenetic processes and provide a better explanation for the dispersion of acoustic data. The difference of acoustic values in palustrine and pedogenic versus lacustrine facies is explained by the prevalence of framework porosity inherited from root systems and vuggy pores from significant dissolution phases in palustrine and pedogenic carbonates. Samples with these pore types behave like an effective medium composed of slightly deformed spheres (aspect ratio close to 1), resulting in a stiffer response than standard differential effective medium models predict. Similar elastic behavior is found only in travertines in the literature. As often in pedogenic deposits, velocities are reduced when complete silicification occurs due to the quartz–calcite compressibility difference. In contrast, the micropores and moldic pores, frequently found in lacustrine facies, form a network resembling crack-like inclusions (aspect ratio ∼ 0.3), consistent with typical carbonate behavior. This study thus underscores significant contrasts in elastic properties between lacustrine and palustrine carbonates, offering new perspectives for distinguishing them across different scales and for investigating subsurface reservoir characteristics
Community Notes undermoderate polarizing content by design creating risks in electoral processes
No full textCommunity Notes (CNs) of X enables users to collaboratively moderate misleading content. To resolve conflicting moderation, CNs infers a latent ideological dimension and selects notes garnering cross-partisan support. As this system is now deployed worldwide, we evaluate its operation across diverse polarization contexts. We analyze all 1.9 million moderation notes receiving 135 million ratings by March 2025, cross-referencing ideological scaling data on 13 countries. Our results show that the CNs algorithm effectively captures the main polarizing dimensions across countries, surfacing notes that garner cross-partisan support. This also means that, by design, CNs systematically under-moderate polarizing content. We analyze notes relating to four recent elections in the US (2024), the UK (2024), France (2024) and Germany (2025) and demonstrate that they are systematically under-moderated when compared to other notes, posing potential risks to civic discourse and electoral processes
Learning-based probabilistic subarray switching for robust low-cost interferometric imaging
No full textInternational audienceComputational cost poses a significant challenge in next-generation interferometric imaging systems. In these systems, the large number of antennas makes it impractical to process all measurements simultaneously due to computational capacity constraints. To reduce the computational burden while preserving image reconstruction quality, we propose a subarray switching strategy that utilizes fewer antennas and different antenna configurations. To take into consideration the influence of the image reconstruction algorithm on the design of the subarray switching pattern and to fully exploit the flexibility of the switching strategy, we propose a probabilistic deep learning-based method for designing antenna switching patterns, named by Probabilistic Antenna Switcher (PAS). In addition to the computational challenge, interferometric systems are also particularly sensitive to the presence of radio frequency interferences (RFI), which heavily affects imaging quality. In order to address this issue, we show that it is possible to combine the proposed PAS with a RFI detection module. Specifically, this module is a neural network that is trained to identify and minimize the impact of RFI-affected antennas in the subarray selection process. This results in a RFI-aware PAS (RaPAS) , which balances computational efficiency, imaging quality, and robustness against RFI
Energy Efficiency and Localization Accuracy in Pinching Antenna-based sub-THz System
No full textInternational audienceThe sub-THz band is a promising candidate for future 6G systems due to its high data rate and precise localization potential. However, it suffers from severe propagation loss, degrading both communication and localization performance. To overcome this issue without relying on complex or costly antenna architectures, we propose a pinching antenna (PA)–based sub-THz system, where PAs have recently emerged as a low-cost, flexible, and reconfigurable solution to mitigate large-scale path loss. The objective is to jointly enhance energy efficiency (EE) and localization accuracy. For this purpose, we formulate an EE maximization problem under a localization constraint, expressed by the Cramer–Rao Bound (CRB), that jointly optimizes antenna positions and transmit power. The resulting problem is non-convex and challenging. Therefore, we employ alternating optimization to decouple it into two subproblems, antenna positioning and power allocation, solved via successive convex approximation. Simulations show that the proposed system mitigates sub-THz limitations and achieves significant gains in terms of EE and localization accuracy over existing fixed and flexible antenna-based schemes
Plug-and-play sanitization for TFHE
No full textFully Homomorphic encryption allows the evaluation of any circuits over encrypted data while preserving the privacy of the data. However, without any additional properties, no guarantee is provided for the privacy of the circuits which are evaluated. A sanitization algorithm allows to destroy all previous information about how a ciphertext was obtained, ensuring that the circuit which was evaluated remains secret. In this paper, we present two new techniques to randomize RLWE ciphertexts, and show how they can be used to achieve ciphertext sanitization for the TFHE scheme proposed by Chilotti et al. (Asiacrypt 2016), by modifying the bootstrapping procedure internally. Our first technique relies on a generalization of the strategy proposed by Bourse et al. (Crypto 2016) to the ring setting. Using a backward induction over the circuit size, we also improve on their proof technique to avoid randomization at each step of the computation, enabling faster randomization and smaller noise growth. While this first approach adapts well in theory, we show evidence that it fails to provide a practical solution and propose a second solution with more realistic parameters at the cost of using an additional public key. As an additional contribution, we improve on the prohibitive size of the public key by relaxing the circuit privacy property to its computational counterpart, and build an efficient public randomizer composed of an RLWE-based public key encryption with additional properties on the ciphertexts distribution. We show that this randomizer can be used in the soak-and-spin paradigm of Ducas and Stehlé (Eurocrypt 2016) as well, and that it yields a significant improvement, mainly in the size of the public key. As a proof of concept, we provide a C implementation of our sanitization strategy, which shows that a sanitized LWE ciphertext can be obtained almost for free compared to a bootstrapped LWE ciphertext assuming many discrete Gaussian samples at hand
Spatiotemporal modulation of the magnetic order in FeRh using sub-gigahertz strain waves
No full textInternational audienceWe probe the first-order hysteretic antiferromagnetic (AFM) to ferromagnetic (FM) phase transition of FeRh in a FeRh/Ta/GaAs stack using surface acoustic waves (SAW) of three different frequencies up to 889 MHz. A clear signature of the phase transition is observed in the Rayleigh velocity and attenuation variations across the phase coexistence temperature range. The velocity variation closely follows the thermal hysteresis exhibited by the phase transition when probed with magnetometry, thereby enabling the determination of the FM fraction of FeRh versus temperature in the SAW path. The variation of attenuation is modeled under the assumption of strain-induced modulation of magnetic order via the movement of AFM-FM phase domain walls (PDWs) at the SAW frequency. This movement is driven by the strain-dependent difference between the AFM and FM Gibbs free energies, which originates from volume magnetostriction. The measured attenuation and its dependence upon the temperature and SAW frequency can be explained through a dissipative mechanism associated with the PDW oscillation driven by the strain wave. Finally, we demonstrate the drastic changes in the temperature dependence of SAW attenuation caused by the applied magnetic field within the FM-rich phase coexistence range, which arise from SAW-induced ferromagnetic resonance