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An endogenous retroviral element co-opts an upstream regulatory sequence to achieve somatic expression and mobility
No full textInternational audienceRetrotransposons, multi-copy sequences that propagate via copy-and-paste mechanisms involving an RNA intermediate, occupy large portions of all eukaryotic genomes. A great majority of their manifold copies remain silenced in somatic cells, nevertheless, some are transcribed, often in a tissue specific manner, and a small fraction retains its ability to mobilize. Retrotransposon expression or mobility are increasingly recognized to contribute to normal development and tissue homeostasis, as well as to aging and disease. While it is well characterized that retrotransposon sequences may provide cis regulatory elements for neighboring genes, how their own expression and mobility are achieved in different somatic contexts is not well understood. Here, using long-read DNA sequencing, we characterize somatic retrotransposition in the Drosophila intestine. We show that retroelement mobility does not change significantly upon aging and is limited to very few active sub-families of retrotransposons. Importantly, we identify a polymorphic donor locus of an endogenous LTR retroviral element rover, active in the intestinal tissue. We reveal that gut activity of the rover donor copy depends on its genomic environment. Without affecting local gene expression, the copy co-opts its upstream enhancer sequence, rich in transcription factor binding sites, for somatic expression. Further we show that escargot, a snail-type transcription factor critical for gut progenitor cell function, can drive transcriptional activity of the active rover copy. These data provide new insights into how locus-specific features allow active retrotransposons to produce functional transcripts and mobilize in a somatic lineage
From Fiduciary Duties to Management Standards: Rethinking the Corporation for Sustainability
No full textInternational audienceAs companies are increasingly expected to address ecological impacts and support green transitions, a key question arises: can standards be developed to assess whether management decisions align with ecological transitions? How can such standards be defined, and under what conditions can they be effective? This paper examines how corporate law shapes the role of managers and what is expected of them. We argue that as long as managers are legally required to pursue the interests of the corporation, management decisions that obstruct ecological transitions will remain almost impossible to challenge in court. We observe that reforms such as increasing stakeholder participation or mandating non-financial reporting do not fundamentally revisit how corporate leaders are expected to manage activities. However, proposals, building, for instance, on corporate purpose or fiduciary duties, are emerging to redefine the criteria for assessing managerial decisions. To capture these diverse efforts, we propose the concept of the management standard. A management standard delineates the criteria that distinguish legitimate sustainable management decisions from misconduct. It provides a basis for accountability and establishes a governance mechanism that is fundamentally different from, yet complementary to, the sharing of voting rights. We identify both the legal and cognitive conditions under which management standards can effectively hold managers accountable for facilitating transitions, enabling us to critically evaluate the various emerging proposals. Drawing on concrete empirical examples, we argue that the concept of the management standard offers a novel lens to rethink the corporation for ecological transitions
Three-phase boundary lines of some random media
No full textMulti components materials show triple phase boundary (TPB) lines at the interface between three components. TPB lines are of primary importance for the performance of electrochemical devices like Solid Oxide Fuel Cells (SOFC). We derive theoretical estimates of the specific length of (TPB) lines Lvijk for a broad range of multicomponent random structures. Since analytical results are obtained, random microstructures with optimal Lvijk can be designed. The effects of the composition, through volume fractions, and of the morphology, through the choice of primary grains, are separate, so that "optimal composition" is derived independently on the geometry. Lvijk is inversely proportional to the square of a length scale of the microstructure. Our theoretical approach is validated by comparison of the predicted Lvijk to some published measurements made on 3D images of materials. Various models designed with the same basic ingredients may show a large range of values for Lvijk , depending on their mode of construction. Much longer Lvijk than experimental measurements in real materials can theoretically be reached, typically over an order of magnitude. This can be used as a guideline to improve the electrochemical behavior of fuel cell components
Impact of aryldiazonium salts grafting onto porous carbon as electrodes for supercapacitors
No full textInternational audienceNew materials are constantly emerging to respond to the desire of having more performant energy storage devices. Among all energy storage devices, supercapacitors also called electrochemical capacitors, have the ability of quickly accumulating charges but lack the important energy density of batteries 1 . Therefore, different types of carbon materials, including graphite, soft and hard carbon as well as nanocarbon, have been investigated to improve the energy storage of such devices, batteries and fuel cells 2 . Surface modification through diazonium salts is a well-known technique for the grafting of molecules on carbons. The covalent attachment of electroactive molecules onto carbon can allow an increase of the capacitance by adding faradaic process to the double layer capacitance of the electrodes. It can also permit to expand the voltage window of the devices to obtain a better energy density which is one of the goals of research in supercapacitors. However, grafting molecules on porous carbon has some drawbacks such as the poor stability of the grafted molecules upon cycling and sometimes the lack or poor increase of the capacity of the device due to pores blockage by the molecules.In this study, we performed the grafting of anthraquinone using diazonium chemistry. Quinones are involved in two electrons exchange redox process that allow to reach higher capacities with less grafted molecules. They are also environmentally friendly, low cost and abundant molecules 3 . Different soft porous carbons 4 , including one carbon aerogel, were used to study the grafting of anthraquinone. Depending on the type of porous carbon and the grafting protocol, we observe that the electrodes made with grafted material do not exhibit the same performances. Each subtract was analyzed by electrochemistry, elemental analyses and spectroscopies to investigate the impact of the grafting on the carbon. This works provides a better understanding of the influence of the porous carbon nature on the grafting of anthraquinone
Identifying the impacts of land use and sedimentary structures on hydrobiogeochemicalfunctioning in nested catchments (Orgeval CZO, France):continuous monitoring of carbon fluxes (DIC, DOC, POC)
No full textInternational audienc
RayGaussX: Accelerating Gaussian-Based Ray Marching for Real-Time and High-Quality Novel View Synthesis
No full textCOLA: COarse-LAbel Multisource LiDAR Semantic Segmentation for Autonomous Driving
No full textInternational audienc
3DLabelProp: Geometric-Driven Domain Generalization for LiDAR Semantic Segmentation in Autonomous Driving
No full textDomain generalization aims to find ways for deep learning models to maintain their performance despite significant domain shifts between training and inference datasets. This is particularly important for models that need to be robust or are costly to train. LiDAR perception in autonomous driving is impacted by both of these concerns, leading to the emergence of various approaches. This work addresses the challenge by proposing a geometry-based approach, leveraging the sequential structure of LiDAR sensors, which sets it apart from the learning-based methods commonly found in the literature. The proposed method, called 3DLabelProp, is applied on the task of LiDAR Semantic Segmentation (LSS). Through extensive experimentation on seven datasets, it is demonstrated to be a state-of-the-art approach, outperforming both naive and other domain generalization methods
Améliorer la recyclabilité des polymères et des composites : synthèse du projet des centres de recherche du Carnot M.I.N.E.S
No full textInternational audienceFace à l’urgence environnementale, comment repenser nos modèles industriels pour construire une économie véritablement circulaire ?À l’heure où l’exploitation intensive des ressources naturelles et l’accumulation des déchets atteignent des niveaux critiques, les cadres réglementaires européens et français fixent des objectifs ambitieux : recycler 55 % des emballages plastiques, incorporer 30 % de plastique recyclé dans les bouteilles d’ici 2030, ou encore interdire la destruction des invendus non-alimentaires. Autant de défis technologiques et organisationnels que les industriels doivent aujourd’hui relever.C’est dans ce contexte exigeant que les laboratoires du Carnot M.I.N.E.S ont conduit un programme de recherche structurant sur trois ans, mobilisant un large collectif scientifique. L’objectif était de développer des solutions concrètes pour améliorer la recyclabilité des polymères dans trois secteurs clés : bouteilles, textiles et composites. Au-delà de ce projet central, l’ouvrage présente également d’autres initiatives portées par le Carnot M.I.N.E.S, témoignant de son engagement constant pour des filières plus durables, plus responsables et plus innovantes.Destiné aux industriels, chercheurs, ingénieurs et décideurs, ce livre s’adresse également à toute personne curieuse de comprendre les enjeux techniques, environnementaux et sociétaux de la transition vers une économie circulaire. Il offre une synthèse rigoureuse et accessible des avancées scientifiques et technologiques au service du recyclage de demain : tri optimisé, intégration de matières recyclées, conception d’éco-matériaux et développement de composites recyclables. Un livre essentiel pour penser l’industrie de demain et accompagner les mutations vers un avenir plus soutenable
An elastoplastic analysis of fretting crack nucleation: Correlation between critical distance and grain size
No full textInternational audienceThis study investigates the influence of microstructural size and stress gradients on crack nucleation in ferrite-pearlite steel under cylinder/plane fretting conditions. An experimental and numerical approach establishes a critical distance that correlates with grain size, revealing a significant distinction between elastic and elastoplastic behaviour. The results indicate that the optimal critical distance l approximates the grain size, highlighting that an internal stress exceeding the fatigue limit σ_(d,-1) is needed to nucleate. The findings emphasize the necessity of elastoplastic modelling for accurately describing the mechanisms of crack nucleation under high stress gradients, as previous elastic-only analyses may yield misleading interpretations