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L’expérience de travail en entreprise dans le NNT en 2025 : Un collectif à réinventer, des responsabilités à partager
No full textLightweight Trustworthy Distributed Clustering
No full textInternational audienceEnsuring data trustworthiness within individual edge nodes while facilitating collaborative data processing poses a critical challenge in edge computing systems (ECS), particularly in resource-constrained scenarios such as autonomous systems sensor networks, industrial IoT, and smart cities. This paper presents a lightweight, fully distributed k-means clustering algorithm specifically adapted for edge environments, leveraging a distributed averaging approach with additive secret sharing, a secure multiparty computation technique, during the cluster center update phase to ensure the accuracy and trustworthiness of data across nodes
Several groups of LysM-RLKs are involved in symbiotic signal perception and arbuscular mycorrhiza establishment
No full textInternational audienceLipo-chitooligosaccharides (LCO) and short-chain chitooligosaccharides (CO) are produced by arbuscular mycorrhizal fungi (AMF) and activate the plant symbiosis signalling pathway, which is essential for mycorrhiza formation. High-affinity LCO receptors belonging to the LysM receptor-like kinase (LysM-RLK) phylogenetic group LYR-IA play a role in AM establishment, but it is unclear which proteins are the plant high-affinity short-chain CO receptors. Here we studied members of the uncharacterized LYR-IB group, and found that they show high affinity for LCO, short-and long-chain CO, and play a complementary role with the LYR-IA receptors for AM establishment. While LYR-IB knock out mutants had a reduced AMF colonization in several species, constitutive/ectopic expression in wheat increased AMF colonization. LYR-IB function is conserved in all tested angiosperms, but in most japonica rice a deletion creates a frameshift in the gene, explaining differences in AM phenotypes between rice and other monocot single LYR-IA mutants. In conclusion, we identified a class of LysM-RLK receptors in angiosperms with unique biochemical properties and a role in both LCO and CO perception for AM establishment
Diatom Phytochromes Integrate the Underwater Light Spectrum to Sense Depth
No full textInternational audienceAquatic life is strongly structured by the distribution of light, which, besides attenuation in intensity, exhibits a continuous change in the spectrum with depth1. The extent to which these light changes are perceived by phytoplankton through photoreceptors is still inadequately known. We addressed this issue by integrating functional studies of diatom phytochrome (DPH) photoreceptors in model species2 with environmental surveys of their distribution and activity. Here, by developing an in vivo dose–response assay to light spectral variations mediated by DPH, we show that DPH can trigger photoreversible responses across the entire light spectrum, resulting in a change in DPH photoequilibrium with depth. By generating dph mutants in the diatom Thalassiosira pseudonana, we also demonstrate that under simulated low-blue-light conditions of ocean depth, DPH regulates photosynthesis acclimation, thus linking optical depth detection with a functional response. The latitudinal distribution of DPH-containing diatoms from permanently stratified regions to seasonally mixed regions suggests an adaptive value of DPH functions in coping with vertical displacements in the water column. By establishing DPH as a detector of optical depth, this study provides a new view of how information embedded in the underwater light field can be exploited by diatoms to modulate their physiology throughout the photic zon
Cylinder with integral position sensor
No full textA cylinder actuator includes two elements mobile one relative to the other along an axis of movement and a position sensor configured to measure the relative position of the two elements, the position sensor comprising a multi-pole magnetic strip secured to a first of the two elements and a sensitive element sensitive to magnetic-field variations and secured to a second of the two elements, the multi-pole magnetic strip having an alternation of north and south poles extending in an interval that defines a measurement range for the measurement of the relative position along the axis of movement, the sensitive element being arranged in such a way as to detect variations in the magnetic field in the vicinity of the multi-pole magnetic strip along the axis of movement within the interval
Visualizing the Soundscape: An Approach at the Interface of Music and Ecology
No full textInternational audienceSoundscape is a concept that expresses several musical, ecological and social realities. In a context where ecosystems and biodiversity are threatened, studying and listening to soundscapes provides a mediation tool with natural environments. Electroacoustic and ecoacoustics have both developed visualization tools to analyze soundscapes. We propose to visualize a corpus of soundscapes differing in sound material, compositional type and acoustic space. This corpus produced by women composers is analyzed with a transdisciplinary approach to improve our ecological and musical perception of soundscapes. For this purpose, we select different efficient visualization tools (Soundscape Chord Diagram, Brightness Standard Deviation, Self-Similarity Matrix) from electroacoustic and ecoacoustics. For the first time, we also propose a multipanel representation of a time wave, the Frequency Band Waveform. All these visualizations allow us to understand the compositional process as well as the ecological information of various soundscapes. This transdisciplinary method of analysis by corpus, here an ecofeminist corpus, seems essential to pursue the development of specific visualization tools for soundscapes.Le paysage sonore est un concept qui exprime plusieurs réalités musicales, écologiques et sociales. Dans un contexte où les écosystèmes et la biodiversité sont menacés, l'étude et l'écoute des paysages sonores constituent un outil de médiation avec les milieux naturels. L'électroacoustique et l'écoacoustique ont développé des outils de visualisation pour analyser les paysages sonores. Nous proposons de visualiser un corpus de paysages sonores qui diffèrent par la matière sonore, le type de composition et l'espace acoustique. Ce corpus produit par des compositrices est analysé avec une approche transdisciplinaire afin d'améliorer notre perception écologique et musicale des paysages sonores. À cette fin, nous avons sélectionné différents outils de visualisation (Soundscape Chord Diagram, Brightness Standard Deviation, Self-Similarity Matrix) issus de l'électroacoustique et de l'écoacoustique. Pour la première fois, nous proposons une représentation de l’onde temporelle en fonction de filtres fréquentiels, la Frequency Band Waveform. Toutes ces visualisations permettent de comprendre le processus de composition ainsi que les informations écologiques de divers paysages sonores. Cette méthode transdisciplinaire d'analyse par corpus, ici écoféministe, semble essentielle pour poursuivre le développement d'outils de visualisation spécifiques aux paysages sonore
Pierre Tiollais (1934-2024), un pionnier du génie génétique et une vie consacrée au virus de l’hépatite B
No full textInternational audiencePierre Tiollais, a French physician-biologist, died on August 5, 2024, at 89. He is celebrated for cloning and sequencing the hepatitis B virus (HBV) genome and developing one of the first recombinant HBV vaccines. Professor at the Pasteur Institute and the University Paris VII (now University Paris Cité), Pierre Tiollais has played a key role in the application of molecular biology and genetic engineering in medical research, notably in the fight against HBV and human immunodeficiency virus (HIV). His work has helped saving millions of lives through vaccination campaigns. Pierre Tiollais was also renowned for his benevolent mentorship and commitment to the scientific community.Pierre Tiollais, médecin et biologiste français, est décédé le 5 août 2024 à l’âge de 89 ans. Il a marqué l’histoire de la médecine par sa contribution au clonage et au séquençage du génome du virus del’hépatite B (VHB), ainsi que par le développement d’un des premiers vaccins recombinants contre ce virus. Professeur à l’Institut Pasteur et à l’Université Paris VII (maintenant Université Paris Cité), il a joué un rôle clé dans l’utilisation de la biologie moléculaire et du génie génétique, notamment dans la lutte contre le VHB et le virus de l’immunodéficience humaine (VIH). Son travail a contribué à sauver des millions de vies humaines grâce à des campagnes de vaccination. Pierre Tiollais était aussi reconnu pour son mentorat bienveillant et son engagement au service de la communauté scientifique
Beyond small ecological acts: how can digital practices activate second order learning?
No full textABS 1International audienceHow can associations use digital technologies to address grand challenges? This paper analyses the digital practices of French associations specialised in Environmental and Sustainable Development Education (ESDE) and the types of learning processes they activate. Based on a case study of 13 ESDE associations through semi-structured interviews, we explore the learning processes these practices activate. To identify ESDE digital practices, we use social practice theory, according to which a practice emerges when performed through the combination of three elements: Material, Competence, and Meaning. Our study identifies 131 ESDE digital practices and concludes that only 17 practices could activate second order learning, which is crucial to deep sustainability transformation. It also underlines the benefits of interdisciplinary research, in our case of using the sociological concept of social practices to analyse organisational practices tackling grand challenges
Monte Carlo Tree Search Based Block Decomposition of CAD Models
No full textInternational audienceDecomposition of CAD models into shapes amenable for automatic meshing such as blocks is a crucial step in hexahedral mesh generation. In this paper, we propose a Monte Carlo Tree Search (MCTS) based approach to obtain possible decomposition solutions for a given CAD model which can be subsequently used for mesh generation. This prototype study shows promises in automating the decomposition of complex shapes into blocks and could be combined in the future with machine learning methods to enhance the method
Caractérisation structurale et production enzymatique de biomarqueurs des mucopolysaccharidoses de type III
No full textGlycosaminoglycans (GAGs) are linear anionic polysaccharides whose repeating unit is a disaccharide specific to each GAG subfamily. Within GAGs, heparan sulfate (HS) are ubiquitous and their constituent disaccharide consists of a uronic acid and a glucosamine. Each uronic acid can undergo epimerization to form either iduronic or glucuronic acids and may also be sulfated at the C2 position of the ring. Similarly, glucosamines can be sulfated at the C3 and C6 positions, and their amine group can be either acetylated or sulfated. These modifications vary significantly within de polysaccharide chain, depending on both the types of cells biosynthesizing the polysaccharide and their environment or stage of development. Consequently, HS polysaccharides are particularly complex and participate in numerous cellular mechanisms.In vivo catabolism of GAGs involves a wide range of different enzymes, and if one of them is altered, undegraded oligosaccharides accumulate within cells, leading to severe disorders known as mucopolysaccharidoses (MPS). These rare genetic diseases disrupt various essential biological processes, causing growth problems and mental delay. MPS III severely impacts neuronal development in particular, leading to a high degree of severity and the earliest mortality among MPS types. It also specifically affects HS metabolism and is groups under the term Sanfilippo syndrome.To develop new therapies tailored to the specificities of MPS III, it is essential to identify one or more reliable biomarkers and to develop analytical methods that allow their monitoring during clinical trials. The HS oligosaccharides that accumulate in these diseases are promising candidates, yet their structural complexity poses a challenge for identifying biomarkers and developing suitable analytical methods.Addressing these issues is the focus of this project, and during this thesis, we developed innovative analytical methods for analyzing HS oligosaccharides accumulated in patient urine. We isolated oligosaccharides by size through chromatography and then elucidated their structures via two mass spectrometry techniques. Using dual analytical methods enabled the structural elucidation of oligosaccharides within complex mixtures and identification of their sulfation and polymerization levels. This method, applied to biological fluid extracts from patients with MPS III, will allow structural elucidation of accumulated oligosaccharides and their tracking throughout clinical trials for therapies. The observed structural variations will also enable us to propose hypotheses regarding the molecular mechanisms of these diseases and to determine why they exhibit a greater severity than other MPS types.Another aspect of the project is to establish structure-activity relationships from oligosaccharides produced in the laboratory. To assess the impact of a variation at the non-reducing end, a feature not previously explored in neuroinflammation mechanisms involved in MPS III, we worked on producing mimics of these potential biomarkers. We developed the synthesis of this non-reducing end using two newly commercialized and minimally studied enzymes enzymes. Ultimately, we will be able to treat neuronal cells in vitro with these oligosaccharides and determine the importance of this non-reducing end in the molecular mechanisms involved in Sanfilippo syndrome.Les glycosaminoglycanes (GAG) sont des polysaccharides linéaires anioniques dont l'unité répétitive est un disaccharide spécifique de chaque sous-famille de GAG. Au sein des GAGs, les héparane sulfate (HS) sont ubiquitaires et leur disaccharide constitutif est composé d'un acide uronique et d'une glucosamine. Chaque acide uronique peut être épimérisé sous forme d'acide iduronique ou glucuronique et peut aussi être sulfaté en position deux du cycle. De la même manière, les glucosamines peuvent être sulfatées en position trois et six et leur amine peut être acétylée ou sulfatée. Ces modifications sont particulièrement hétérogènes au sein de la chaîne polysaccharidique et dépendent tout autant des types de cellules biosynthétisant le polysaccharide que de l'environnement de celles-ci ou de leur développement. Ainsi, les polysaccharides de HS sont particulièrement complexes et interviennent dans de nombreux mécanismes cellulaires.Le catabolisme in vivo des GAGs fait intervenir un grand nombre d'enzymes différentes et si l'une d'entre elle est altérée, les oligosaccharides non catabolisés s'accumulent au sein des cellules et entraînent des pathologies graves regroupées sous le terme de mucopolysaccharidoses (MPS). Ces maladies génétiques rares affectent de nombreux processus biologiques essentiels et entraînent des problèmes de croissance et de retard mentaux. Les MPS III affectent spécifiquement le développement neuronal à un niveau de gravité élevé et sont les MPS causant la mortalité la plus précoce. Par ailleurs, elles affectent uniquement le métabolisme des HS et sont regroupées sous le terme de syndrome de Sanfilippo.Dans le but de développer des thérapies adaptées aux spécificités des MPS III, il est nécessaire d'identifier un ou plusieurs biomarqueurs fiables et de développer des méthodes d'analyses permettant leur suivi lors de tests cliniques. Les oligosaccharides de HS accumulés lors de ces maladies sont de bons candidats mais leur complexité structurale est un défi dans l'identification de biomarqueurs et le développement de méthodes d'analyse adaptée.Répondre à ces problématiques est l'objet de ce projet et lors de cette thèse nous avons développé des méthodes novatrices d'analyse des oligosaccharides de HS accumulés dans l'urine de patients. Ainsi, nous avons isolé des oligosaccharides selon leur taille par chromatographie puis élucidé leur structure par deux méthodes de spectrométrie de masse. L'utilisation de deux méthodes d'analyse a permis l'élucidation structurale d'oligosaccharides contenues dans des mélanges complexes et l'identification de leur degré de sulfatation et de polymérisation. Cette méthode, appliquée à des extraits de fluides biologiques de patients atteints de MPS III, permettra l'élucidation structurale des oligosaccharides accumulés ainsi que leur suivi lors de test clinique de thérapies. Les variations structurales permettront aussi de proposer des hypothèses sur les mécanismes moléculaires de ces maladies et déterminer la raison de leur degré de gravité plus sévère que les autres MPS.Une autre approche du projet est l'obtention de relations structure-activité à partir d'oligosaccharides produits au laboratoire. Dans le but d'évaluer l'impact d'une variation de l'extrémité non-réductrice encore jamais explorée dans les mécanismes de neuroinflammation, nous avons travaillé sur la production de mimes de ces biomarqueurs potentiels. Nous avons donc développé la synthèse de cette extrémité non réductrice à l'aide de deux enzymes nouvellement commercialisées et peu étudiées. Ainsi, nous pourrons, à terme, traiter in vitro des cellules neuronales avec ces oligosaccharides et déterminer l'importance de cette extrémité non-réductrice dans les mécanismes moléculaires impliqués dans le syndrome de Sanfilippo