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Profiling Protein-Binding Glycosaminoglycan Oligosaccharides Using a Simple Label-Free Electrophoretic Assay
No full textInternational audienceGlycosaminoglycans (GAGs) interact with numerous proteins to regulate key biological processes such as coagulation, cell migration, and growth factor signaling. Despite their biological importance, mapping these interactions and identifying the structural determinants that govern GAG–protein recognition remains analytically challenging, particularly in complex or polydisperse systems. Here, we introduce a simple, label-free carbohydrate polyacrylamide gel electrophoresis (C-PAGE) approach that visualizes GAG–protein complex formation through binding-induced signal suppression of GAG bands. Instead of tracking the mobility of protein–GAG complexes, as it is classically performed in gel-shift assays, C-PAGE directly monitors the disappearance of the free GAG bands stained with Stains-All. Using model high-affinity heparin-binding proteins, the chemokine stromal cell-derived factor 1 α (SDF-1α) and the basic fibroblast growth factor (FGF-2), we demonstrate that C-PAGE clearly distinguishes specific interactions with heparin oligosaccharides from non-binding controls. The method was successfully extended to a micromolar-affinity heparin-binding protein, the interleukin 8 (IL-8), and to complex mixtures such as low-molecular-weight heparins (LMWH), revealing the preferential disappearance of highly sulfated and/or longer GAG species. Competitive assays further enabled qualitative ranking of GAG binding affinities. Finally, the selective interaction of antithrombin III with 3-O-sulfated motifs was unambiguously detected, underscoring the remarkable sensitivity of C-PAGE to fine structural modifications. Altogether, C-PAGE provides a rapid, visual, and cost-effective screening tool to assess GAG–protein binding specificity and structure–activity relationships, complementing advanced biophysical and structural methods in fundamental and applied glycobiology
Explaining Algorithms: How Transparency Shapes Public Support
No full textThe Digital Services Act and the AI Act adopted by European institutions require algorithmic decisionmaking systems to meet transparency obligations through the provision of explanations of their functioning. As algorithmic decision-making systems increasingly shape individuals' economic and social lives, this paper experimentally tests whether adding a non-technical explanation to a neutral system description affects public acceptance. The study relies on a large-scale survey experiment on nationally representative adult samples in France, Germany, and Italy in which each respondent evaluates six algorithmic and AI systems spanning finance, health, public services, employment, online commerce, and digital media. We measure the economically relevant dimensions of adoption and legitimacy, including beliefs, evaluative attitudes, and willingness to delegate decisions. Explanations yield measurable, though modest, increases in willingness to delegate. A mechanism-consistent decomposition shows that these effects arise primarily through improved attitudes toward the systems, while direct effects and belief shifts play a secondary role. Overall, explanations reliably move acceptance in the intended direction, but do not eliminate persistent concerns, especially those related to privacy. The results highlight both the promise and limits of information disclosure as a regulatory tool
Distance aux optimalités dans l'analyse des inégalités multidimensionnelles, une adaptation du front de Pareto pour hiérarchiser les priorités.
No full textInternational audienc
Molecular Simulations of Polymer‐based Drug Nanocarriers: From Physical and Structural Properties to Controlled Release
No full textInternational audiencePolymer‐based drug delivery systems have been extensively studied to overcome the limitations of free drug administration (e.g., poor solubility and stability, rapid degradation and early metabolization, short plasma half‐life, low therapeutic efficacy, and occurrence of side effects). Although the vast majority of these drug delivery systems are developed using the traditional time‐ and resource‐intensive trial‐and‐error method, computational techniques have received considerable attention in order to facilitate and accelerate their understanding and development. In this review, several computational techniques is presented that are commonly used to study polymer‐based drug delivery systems. Then, this is discussed several computational investigations of the self‐assembly and supramolecular organization of polymer nanocarriers for drug delivery applications, including drug‐loaded polymer micelles and polymer prodrug nanoparticles. How modeling approaches can rationalize the drug loading and release from polymer drug delivery systems is further examined, including studies which aim to better understand how physical, chemical, or biological stimuli can trigger the drug release. Machine learning possibilities for extending physics‐based molecular simulation efficiency and predictive power have also been briefly discussed
« Les jeunes sont très lucides sur leur usage des réseaux sociaux et sont parfois mieux outillés que nous »
No full textAlors qu’Emmanuel Macron souhaite interdire aux moins de 15 ans l’accès aux réseaux sociaux, les chercheuses Rosa Maria Bortolotti et Sigolène Couchot-Schiex, qui étudient les pratiques des adolescents en ligne, émettent des réserves
Quarante ans après l'adhésion : l'Espagne, miroir et laboratoire de l'intégration européenne
No full textInternational audienceIntroductio
Les obstacles et leviers à l’inclusion numérique des personnes âgées
No full textInternational audienceThis article presents a literature review on the barriers and drivers of digital inclusion among older adults that may foster their engagement in the appropriation of technologies. Research shows that, at the individual level, a lack of motivation and interest constitutes a major barrier to older adults’ use of digital technologies (Helsper & Reisdorf, 2013). Physical and cognitive vulnerabilities, such as sensory limitations or cognitive decline, can also hinder the learning and use of technologies (Khosravi & Ghapanchi, 2016; Vigouroux-Zugasti, 2017). At the psychosocial level, negative attitudes, technology-related fears, and ambivalent social representations of ageing significantly influence older adults’ digital engagement (Bergström, 2023; Yang et al., 2022). Cultural contexts and societal values also shape this process, as evidenced by studies conducted in Sweden, China, and France (Bergström, 2023; Liu et al., 2021). Identified drivers for overcoming these barriers include strengthening intrinsic motivation and perceived competence through training programmes (Quialheiro et al., 2023), as well as personalised approaches that address the specific needs of older adults (Tomczyk et al., 2023). Promoting social participation and recognition, particularly through friendly and intergenerational learning environments, has also proven effective in supporting older adults’ appropriation of technologies (Pihlainen et al., 2023; Vigouroux-Zugasti, 2017).Cet article propose une revue de littérature sur les obstacles et les leviers à l’inclusion numérique des personnes âgées pouvant favoriser leur engagement dans l’appropriation des technologies. Les recherches montrent que, sur le plan individuel, le manque de motivation et d’intérêt constitue un obstacle majeur à l’utilisation des technologies numériques par les personnes âgées (Helsper & Reisdorf, 2013). Les vulnérabilités physiques et cognitives, telles que les limitations sensorielles ou le déclin cognitif, peuvent également entraver l’apprentissage et l’utilisation des technologies (Khosravi & Ghapanchi, 2016 ; Vigouroux-Zugasti, 2017). Au niveau psychosocial, les attitudes négatives, les peurs associées aux technologies et les représentations sociales ambivalentes du vieillissement influencent significativement l’engagement numérique des personnes âgées (Bergström, 2023 ; Yang et al. , 2022). Les contextes culturels et les valeurs sociétales modulent également ce processus, comme le montrent des études menées en Suède, en Chine et en France (Bergström, 2023 ; Liu et al. , 2021). Les leviers identifiés pour surmonter ces obstacles incluent le renforcement de la motivation intrinsèque et du sentiment de compétence à travers des programmes de formation (Quialheiro et al. , 2023), ainsi que des approches personnalisées qui répondent aux besoins spécifiques des personnes âgées (Tomczyk et al. , 2023). La promotion de la participation sociale et de la reconnaissance, notamment via des environnements d’apprentissage conviviaux et intergénérationnels, s’avère également efficace pour soutenir l’appropriation des technologies par les personnes âgées (Pihlainen et al. , 2023 ; Vigouroux-Zugasti, 2017)
Middle Eocene hyperthermal seasonality from Paris Basin marine mollusks
No full textInternational audienceThe Earth has experienced hyperthermal events in the past, characterized by maximum durations of hundreds thousand years, significant magnitude, global extent, and drivers associated with increases in greenhouse gas concentrations, therefore making them potential analogues for current climate change. The Middle Eocene Climatic Optimum (MECO) that occurred 40 Ma ago, is marked by a CO2-driven global warming of +4 to +6° C, affecting global temperatures. Here, we present a detailed reconstruction of seasonal fluctuations in seawater temperatures during this warming event in littoral environment, based on geochemical analyses (δ18O and Δ47) of shallow-marine mollusks from the Paris Basin. Our data show a stability in mean winter temperatures compared to pre-MECO conditions, but a marked warming of +10°C in maximum estuarine water temperatures, with a seasonal temperature range increasing from 12°C before the MECO to 22°C at the climax of the event. We demonstrate that at mid-latitudes, annual maximum shallow-water temperatures increased from 30 ± 2°C before the event to a maximum of 41 ± 4°C at the warming peak. This pattern is associated with a seasonal regime characterized by dry summers and wet winters, implying that the Paris Basin experienced a super-hot summer Mediterranean climate during the MECO
150 years of ground-based solar instrumentation at Meudon observatory (1876-2026)
No full textCe document est la version ANGLAISE du document en françaishttps://cnrs.hal.science/hal-05466472The Sun has been observed through a telescope for four centuries. However, its study made a prodigious leap at the end of the nineteenth century with the appearance of photography and spectroscopy, then at the beginning of the following century with the invention of the coronagraph and monochromatic filters, and finally in the second half of the twentieth century with the advent of large ground-based telescopes and space exploration. This article retraces the main stages of solar instrumental developments in Meudon, from its foundation by Jules Janssen in 1876 to the present day, limited to ground-based or balloon instrumentation, designed in Meudon and installed there or in other places (Nançay, Pic du Midi, Canary Islands). The Meudon astronomers played a pioneering role in the history of solar physics through the experimentation of innovative techniques. After the golden age of inventions, came the time of large instruments, studied in Meudon but often installed in more favourable sites, and that of space, in a framework of international collaboration, but this is not discussed here