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Epigenetics and non-coding RNAs in host–endosymbiont interactions: insights from Wolbachia and beyond
No full textInternational audienceSymbioses are widespread in nature and are among major evolutionary forces. Insects have recurrently established intracellular symbioses with bacteria, balancing between immune responses and homeostasis. The processes involved in endosymbiosis establishment, maintenance, and control have recently been associated with epigenetic pathways and non-coding RNAs, which are known to regulate a wide range of cellular processes, including development, differentiation, immune response, and metabolism. Using the well-studied Wolbachia-Aedes aegypti model as a reference, we summarize how these mechanisms influence host gene expression, endosymbiont maintenance, and antiviral defence. Beyond Wolbachia, only a few examples have provided functional evidence of the role of epigenetics in regulating natural insect-bacteria associations. Collectively, these studies demonstrate that epigenetic factors can act as mediators of host-endosymbiont coordination; however, determining if such factors are drivers or by-products of symbiosis establishment will require further investigatio
Smart zwitterionic biodegradable hydrogel for sustained peptide delivery: Application to the neurotherapeutic peptide NX210c
No full textInternational audienceTherapeutic peptides offer a promising balance between specificity, safety, and bioavailability. However, their clinical use is limited by poor in vivo stability and short half-life, requiring frequent administrations that can compromise patient compliance and therapeutic outcomes. NX210c, a synthetic cyclic dodecapeptide derived from the thrombospondin repeat motif of the sub-commissural organ-spondin shows neuroprotective effects, making it a promising candidate for the treatment of neurological disorders. However, its short half-life (~15 min) requires intravenous infusion highlighting the interest of an alternative delivery method to improve the quality of life for patients.This study, report the preclinical development of an injectable, biodegradable chitosan-based hydrogel functionalized with the macrocyclic ligand DOTAGA, designed for the sustained subcutaneous release of NX210c. The hydrogel forms in situ under physiological conditions, via electrostatic and hydrogen bonding interactions. The solvent-free formulation is simple and clinically compatible. Hydrogel candidate were screened in vitro for injectability, gelation, peptide loading, and release kinetics. In vivo validation on rodents confirmed subcutaneous injectability, gelation ability, biocompatibility and biodegradability within few weeks. Pharmacokinetics studies demonstrated distinct profiles: intravenous injection led to peptide clearance within 1 h; free NX210c administered subcutaneously slightly prolonged its presence in the bloodstream, with complete elimination observed within approximately 3 h. The use of hydrogel, enables AUCs dozens of times higher, with peptide levels sustained for over 10 to 15 days. These results highlight the hydrogel's potential as a patient-friendly, clinically translatable platform for therapeutic peptides requiring sustained release. Future studies will focus on the evaluation of its therapeutic efficiency.</div
EcoViz: a tool for visual analysis and photorealistic rendering of forest landscape model simulations
No full textInternational audienceSimulation outputs from forest landscape models are complex, and tools for their visual analysis and effective communication are often limited. In this paper, we present EcoViz, a novel, open‐source visualisation platform designed to complement existing forest models by providing advanced 3D visualisation capabilities. EcoViz facilitates the exploration of simulation results through two primary modes: symbolic rendering, designed for analytical tasks, such as pattern recognition and model evaluation, and photorealistic rendering, leveraging physically based rendering (Mitsuba 3) and a custom library of European 3D tree models for communication purposes. The platform imports spatially explicit individual tree or cohort data and employs a temporally coherent sampling technique to visualise individual trees derived from cell‐based density maps. Key features include: interactive side‐by‐side comparison of different simulation scenarios or time points, with synchronised navigation (viewpoint, timeline, transects), a mini‐map overview, timeline controls with linked ecological metric graphs, and transect analysis tools. The practical application of EcoViz is demonstrated by visualising simulations of the Berchtesgaden National Park under baseline and climate change scenarios exported from a forest landscape model. This case study showcases EcoViz's utility for comparative scenario analysis across spatial scales and how it aids model evaluation through visual inspection. While symbolic views support detailed analysis, the photorealistic output offers a compelling tool for science communication with diverse audiences, including scientific peers, forest managers, and the public
Le jeu d’évasion comme outil de médiation scientifique : enjeux méthodologiques, éthiques et pragmatiques d’une vulgarisation scientifique
No full textInternational audiencetool for scientific mediation: methodological, ethical, and pragmatic challenges of science communicationCet article analyse la conception et la mise en œuvre d’un jeu d’évasion (appelé couramment escape game) comme dispositif de médiation scientifique pour partager aux acteurs de terrain les résultats d’une enquête ethnographique menée au sein d’unités militaires françaises. Conçu à partir des étapes centrales du travail de terrain (observation, immersion, analyse), le jeu engage les participants dans des épreuves mobilisant à la fois compétences physiques et intellectuelles, afin de rendre visibles les dimensions méthodologiques et éthiques de la recherche. Au-delà d’une simple modalité de partage des résultats, le jeu d’évasion favorise une réflexivité partagée entre chercheuse et militaires, en ouvrant un espace de dialogue critique sur les normes, identités et pratiques professionnelles. L’analyse met en évidence les apports de ce dispositif en termes d’appropriation des savoirs, de co-construction et de transparence, tout en soulignant ses limites liées au coût et aux contraintes logistiques. Cette expérience invite à repenser les modalités de communication scientifique en anthropologie et à interroger les articulations possibles entre jeu, travail, production de savoirs, éthique scientifique et rôles des acteurs de terrain dans une anthropologie « avec »
Effect of a compliant substrate on the rebound of a spherical shell
No full textInternational audienceThe impact between a spherical shell (a table-tennis ball, in practice) and a compliant silicone surface is studied. Experimentally, the potential for achieving higher reflected angular velocity on a compliant surface compared to a rigid one is explored with special attention given to the roles of friction and of the soft substrate deformability. Additionally, local observations of the contact region and potential buckling of the spherical shell are pursued. In normal incidence, the main effect of the soft substrate on the rebound is a decrease in the coefficient of restitution of the linear velocity and an increase in the duration of contact, without a clear dependence on the substrate thickness. In addition, by observing the shell geometry at contact it was found that the shell flattening prior to its buckling is smaller on a soft surface than that observed on a rigid surface. In oblique incidence, the introduction of a soft layer clearly increases the ability of the substrate to transfer spin to the spherical shell, with a significant dependence on the layer thickness. A mechanical model incorporating linear elasticity of the surface shows a good correlation with the latter experimental results
L-distributions augmentées - version ASGARD
No full textThis code allows generating ALD model coefficients. Its starts from LBL data, performs the high-dimensional regression of the ALD model and then compares band averaged transmissivities of non-uniform atmospheric paths using LBL and ALD methods.Ce code permet de générer des paramètres pour le modèle ALD. Partant de données raies-par-raies, le code réalise la régression des paramètres et compare le modèle ALD obtenu avec des données de références raies-par-raies dans des situations d'atmosphères non-uniformes
An Interpretable Model for Multi-Target Predictions with Ordinal Outputs
No full textInternational audienceMulti-Target Prediction (MTP) aims to predict a class for multiple targets from a single input instance. In this paper, we focus on the general ordinal outputs setting, where targets may have different numbers of ordered classes. This scenario is under-explored yet critical for human-centered applications such as educational assessment or psychological profiling. In these domains, targets span multiple aspects of an evaluation, and capturing latent relationships between seemingly independent targets is essential for deriving meaningful user profiles. Beyond prediction accuracy, it is crucial that the resulting profiles are interpretable, as these applications directly impact humans. We introduce IMPACT, a novel method that extends existing binary MTP frameworks (such as CD-BPR) to the multi-class domain through a newly designed loss function. Rooted in a Bayesian modeling framework, IMPACT jointly embeds user profiles and targets within a shared vector space, providing theoretical rigor while explicitly optimizing for both predictive accuracy and interpretability. Furthermore, IMPACT offers a geometric interpretation of the embedding learning dynamics, giving insight into how the model captures relationships between users and targets and providing an intuitive understanding of profile formation in the latent space. Experimental results show that IMPACT outperforms state-of-the-art approaches in terms of profile interpretability while maintaining competitive prediction accuracy. An ablation study highlights the contribution of each component, demonstrating the benefits of extending the framework to multiple ordered classes, the Bayesian formulation, and the geometric interpretability in enhancing both performance and transparency
Dynamical analysis and numerical simulation of a reaction-diffusion model for microbial decomposition of organic matter in 3D soil structure
No full textMicrobial decomposition of organic matter in soil is a fundamental process in the global carbon cycle, directly influencing soil health, fertility, and greenhouse gas emissions. This paper presents a dynamic analysis and numerical simulation of a reaction-diffusion model that describes microbial decomposition of organic matter within a three dimensional soil structure. We investigate the interactions between {Microbial Biomass} (MB) and organic substrates, as well as the diffusion of various compounds through the soil matrix, using nonlinear parabolic partial differential equations. Our study provides proofs for the existence and uniqueness of solutions, as well as an analysis of asymptotic behavior. Notably, our investigation reveals the presence of a global attractor, where any solution, regardless of initial conditions, tends to converge. To illustrate the practical implications of our findings, we have developed a numerical tool to simulate the long-term behavior of the system with reasonable computational expense. This tool provides a visual proof of the global attractor for a validated set of biological parameters in a real sandy loam soil sample captured using 3D tomography imagery
Problèmes ouverts en géométrie symplectique quantitative et étude des billards
No full textThis document collects contributions to the Open Problem List in Billiards and Quantitative Symplectic Geometry, compiled following discussions during the workshop "Billiards and quantitative symplectic geometry" that took place at the University of Heidelberg on July 14-18, 2025