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Créer-penser-éprouver : le théâtre comme laboratoire des puissances de vie
No full textInternational audiencePour la Recherche-création, art et science sont deux domaines complémentaires de recherche, de création collective et de mise en mouvement de la pensée en acte (Manning et Massumi). Nous prendrons pour exemple la pièce E ainda assim se levantar. Dans ce théâtre de recherche, on expérimente sur le plateau à la croisée des SHS et des vies personnelles des acteurs l’épreuve de la convergence du fascisme, du néolibéralisme, du masculinisme, de l’homophobie. Les lignes de forces des situations et les puissances de vie sont éprouvées ; pensées et actions émergent des corps et des affects. On découvre et fait éprouver le capitalisme comme force centrifuge et comme épreuve permanente, l’intersection des haines, le difficile chemin pour trouver la force, puisant dans la musique, la culture, le commun, de se (sou-)lever. C’est ce geste, se relever, qui naît collectivement des corps et des affects sur scène, qui est transmis au public, et l’entraine dans son mouvement affirmatif et performatif. Un geste mineur (Manning), divergent, qui remet en mouvements les corps et les pensées
Mean field limits of interacting particle systems with positive stable jumps
No full textInternational audienceThis note is a companion article to the recent paper [Löcherbach, et al. Electronic J. Probab. (2025) in press]. We consider mean field systems of interacting particles. Each particle jumps with a jump rate depending on its position. When jumping, a macroscopic quantity is added to its own position. Moreover, simultaneously, all other particles of the system receive a small positive random kick which is distributed according to a one-sided α−stable law and scaled in N−1/α, where 0 < α < 1. In between successive jumps of the system, the particles follow a deterministic flow with drift depending on their position and on the empirical measure of the total system. In a more general framework where jump amplitudes and state space do not need to be non-negative, we have shown in [Löcherbach, et al. Electronic J. Probab. (2025) in press] that the mean field limit of this system is a McKean-Vlasov type process which is solution of a non-linear SDE, driven by an α−stable process. Moreover we have obtained in [Löcherbach, et al. Electronic J. Probab. (2025) in press] an upper bound for the strong rate of convergence with respect to some specific distance disregarding big jumps of the limit stable process. In the present note we consider the specific situation where all jump amplitudes are positive, and particles take values in ℝ+. We show that in this case it is possible to improve upon the error bounds obtained in [Löcherbach, et al. Electronic J. Probab. (2025) in press] by using an adhoc distance obtained after applying a concave space transform to the trajectories. The distance we propose here takes into account the big jumps of the limit α−stable subordinator
Conceptualiser le phénomène de l'identité numérique en santé
No full textInternational audienceDigital identity is a well-established concept encompassing the entitlements and claims individuals hold over their digital records. However, the specific term "digital health identity" remains underexplored and requires conceptualization to account for the unique and diverse nature of health-related digital data. This study addresses this gap by conceptualizing the digital health identity using phenomenon construction that combines theoretical insights, empirical evidence, and pre-understanding. Situated within the European Health Data Space (EHDS) ecosystem, this research examines the critical dilemmas of context, concept, and functionality that underpin digital health identity. By resolving these challenges, the study advances conceptual clarity, enabling a more nuanced understanding of the term. Implications emphasize the importance of this conceptualization for guiding future research in health dataspaces and data sharing, informing policy frameworks, and advancing the governance and ethical use of health data in the digital era.L'identité numérique est un concept bien établi qui englobe les droits et revendications des individus sur leurs données numériques. Cependant, le terme spécifique "identité numérique en santé" reste sous-exploré et nécessite une conceptualisation pour refléter la nature unique et diversifiée des données numériques liées à la santé. Cette étude comble cette lacune en conceptualisant l'identité numérique en santé à travers une construction phénoménologique combinant des perspectives théoriques, des preuves empiriques et une précompréhension. Dans la continuité de l'Espace européen des données de santé, cette recherche examine les dilemmes critiques liés au contexte, au concept et à la fonctionnalité qui sous-tendent l'identité numérique en santé. En résolvant ces enjeux, l'étude apporte une clarté conceptuelle, permettant une compréhension plus nuancée du terme. Les implications soulignent l'importance de cette conceptualisation pour orienter les recherches futures, informer les cadres politiques et renforcer la gouvernance et l'utilisation éthique des données de santé à l'ère numérique
Comprehensive multi-omics integration to unravel poplar molecular responses to a phenanthrene contamination gradient
No full textInternational audienceRhizobium–legume nitrogen-fixing symbiosis involves the formation of a specific organ, the root nodule, which provides bacteria with the proper cellular environment for atmospheric nitrogen fixation. Coordinated differentiation of plant and bacterial cells is an essential step of nodule development, for which few transcriptional regulators have been characterized. Medicago truncatula ETHYLENE RESPONSE FACTOR REQUIRED FOR NODULE DIFFERENTIATION (MtEFD) encodes an APETALA2/ETHYLENE RESPONSIVE FACTOR (ERF) transcription factor, the mutation of which leads to both hypernodulation and severe defects in nodule development. MtEFD positively controls a negative regulator of cytokinin signaling, the RESPONSE REGULATOR 4 (MtRR4) gene. Here we showed that that the Mtefd-1 mutation affects both plant and bacterial endoreduplication in nodules, as well as the expression of hundreds of genes in young and mature nodules, upstream of known regulators of symbiotic differentiation. MtRR4 expressed with the MtEFD promoter complemented Mtefd-1 hypernodulation but not the nodule differentiation phenotype. Unexpectedly, a nonlegume homolog of MtEFD, AtERF003 in Arabidopsis (Arabidopsis thaliana), could efficiently complement both phenotypes of Mtefd-1, in contrast to the MtEFD paralog MtEFD2 expressed in the root and nodule meristematic zone. A domain swap experiment showed that MtEFD2 differs from MtEFD by its C-terminal fraction outside the DNA binding domain. Furthermore, clustered regularly interspaced short palindromic repeats-CRISPR associated protein 9 (CRISPR-Cas9) mutagenesis of MtEFD2 led to a reduction in the number of nodules formed in Mtefd-1, with downregulation of a set of genes, including notably NUCLEAR FACTOR-YA1 (MtNF-YA1) and MtNF-YB16, which are essential for nodule meristem establishment. We, therefore, conclude that nitrogen-fixing symbiosis recruited two proteins originally expressed in roots, MtEFD and MtEFD2, with distinct functions and neofunctionalization processes for each of them
Venir travailler dans l'ESS quand on est fonctionnaire : quelle construction de sens ?
No full textInternational audienceCommunication inscrite dans l'axe 1 "Insérer, former, traduire", animée par Josette Combes lors des sessions du mardi 27 mai (14h00 - 15h30
From Glosten-Milgrom to the whole limit order book and applications to financial regulation
No full textWe build an agent-based model for the order book with three types of market participants: an informed trader, a noise trader and competitive market makers. Using a Glosten-Milgrom like approach, we are able to deduce the whole limit order book (bid-ask spread and volume available at each price) from the interactions between the different agents. More precisely, we obtain a link between efficient price dynamic, proportion of trades due to the noise trader, traded volume, bid-ask spread and equilibrium limit order book state. With this model, we provide a relevant tool for regulators and market platforms. We show for example that it allows us to forecast consequences of a tick size change on the microstructure of an asset. It also enables us to value quantitatively the queue position of a limit order in the book
Un modèle fluide en 2D pour la migration cellulaire individuelle
No full textThis paper is devoted to the analysis and numerical simulations of a 2D model of single-cell crawling migration focusing on the intracellular dynamics. The fluidbased model relies on the interaction between the actin cytoskeleton and a generic molecular regulator of its activity. It writes as a Poisson problem with Darcy law coupled with a nonlocal advection-diffusion problem on the molecular concentration, where the nonlocal term involves boundary values. Existence and uniqueness of resting and traveling stationary states are established in some parameter domains, together with the linear stability in the resting case. Numerical simulations allow to illustrate both cell regimes. Additive stochastic perturbations of the advection field by a colored Gaussian noise allow to generate numerical trajectories ranging from diffusive to ballistic behaviours, in coherence with experimental data and previous modelling from [1]. A positive correlation between velocity and persistence is also recovered. This highlights the model's ability to capture key features of cell migration
LABARRE, Albert. Paris, 16 octobre 1927 – Paris, 30 janvier 2010
No full textBibliothécaire à Amiens, puis conservateur en chef à la BN, il est l’auteur de nombreux ouvrages et articles sur l’histoire du livre
Mechanical Characterization and Microstructural Analysis of Extruded 2017A Aluminum Alloy: Effects of Heat Treatments on Fatigue Damage Behavior
No full textInternational audienceThis study examines the impact of heat treatment on the mechanical properties, microstructure, and fatigue performance of extruded AA2017 aluminum alloy. Tubular specimens undergo various heat treatments and quenching methods. The mechanical properties were assessed through hardness, tensile, and fatigue tests, whereas the microstructure was analyzed using microscopy techniques. Results show that T6 state (120°C and 160°C) enhances hardness, tensile strength, and fatigue life due to fine, coherent Al₂Cu precipitates. T7 states (240°C) produce over‐aged microstructures with larger, incoherent precipitates, reducing strength and ductility. Icy saltwater quenching yields finer precipitates and better fatigue resistance than liquid nitrogen quenching. T6 conditions favor elastic adaptation, whereas T7 conditions show plastic shakedown. Fracture surface analysis reveals ductile failure in T6 states and mixed ductile‐brittle behavior in T7 states. These findings provide insights for optimizing heat treatment parameters to enhance 2017A alloy performance in high‐strength, fatigue‐resistant applications
Modal analysis of the triadic interactions in the dynamics of a transitional shock wave boundary layer interaction
No full textInternational audienceThis work is a numerical study of a transitional shock wave boundary layer interaction (SWBLI). The main goal is to improve our understanding of the well-known low-frequency SWBLI unsteadiness and especially the suspected role of triadic interactions in the underlying physical mechanism. To this end, a direct numerical simulation is performed using a high-order finite-volume scheme equipped with a suitable shock capturing procedure. The resulting database is then extensively post-processed in order to extract the main dynamical features of the interaction zone dynamics (involved characteristic frequencies, characteristics of the vortical structures, etc.). The dynamical organisation and space–time evolution of the flow at dominant frequencies are then further characterised by mean of an spectral proper orthogonal decomposition analysis. In order to study the role of triadic interactions occurring in the interaction region, a bispectral mode decomposition analysis is applied to the database. It allows us to extract the significant triadic interactions, their location and the resulting physical spatial modes. Strong triadic interactions are detected in the downstream part of the separation bubble whose role on the low-frequency unsteadiness is characterised. All the results of the various analyses are then discussed and integrated to formulate a possible mechanism fuelling low-frequency SWBLI unsteadiness