HAL-ENS-LYON
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HIV Vpr activates a nucleolar-specific ATR pathway to degrade the nucleolar stress sensor CCDC137
No full textInternational audienceThe lentiviral accessory protein Vpr engages an extensive network of cellular pathways to drive diverse host consequences. Of its many phenotypes, CRL4A-E3 ubiquitin ligase complex co-option, DNA damage response (DDR) engagement, and G2/M arrest are conserved and thus proposed to be functionally important. How Vpr effects these functions and whether they explain how Vpr dysregulates additional cellular pathways remain unclear. Here we leverage the ability of Vpr to deplete the nucleolar protein CCDC137 to understand how Vpr-induced DDR activation impacts nucleolar processes. We characterize CCDC137 as an indirect Vpr target whose degradation does not correlate with Vpr-induced G2/M arrest. Yet, degradation is conserved among Vpr from the pandemic HIV-1 and related SIVcpz/SIVgor, and it is triggered by genomic insults that activate a nucleolar ATR pathway in a manner similar to camptothecin. We determine that Vpr causes ATR-dependent features of nucleolar stress that correlate with CCDC137 degradation, including redistribution of nucleolar proteins, altered nucleolar morphology, and repressed ribosome biogenesis. Together, these data distinguish CCDC137 as a non-canonical Vpr target that may serve as a sensor of nucleolar disruption, and in doing so, identify a novel role for Vpr in nucleolar stress
Comment réussir la coopération inter-entreprises au service de l’écologie industrielle territoriale ?
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IA et médiation scientifique : perception, usages et besoins
No full textArtificial intelligence, particularly generative AI, has been booming since the launch of ChatGPT in late 2022. It surrounds us at every level of our lives, including in the professional sphere. This thesis takes stock of the perceptions, uses and needs of scientific mediation professionals in relation to artificial intelligence. This work is based on semi-structured interviews conducted with these professionals and addresses numerous hypotheses concerning the uses, needs, and barriers to the use of AI.L'intelligence artificielle, notamment l'IA générative, connaît actuellement un essor depuis le lancement de ChatGPT fin 2022. Celle-ci nous entoure en effet à tous les niveaux de nos vies, y compris dans le milieu professionnel. Ce mémoire fait ainsi l'état des lieux des perceptions, des usages et des besoins de professionnels et professionnelles de la médiation scientifique en lien avec l'intelligence artificielle. Ce travail s'appuie sur des entretiens semi-directifs menés avec ces professionnels, et répond à de nombreuses hypothèses concernant les usages, les besoins et les freins à l'usage de l'IA
心理学的控制论理念：面对康吉莱姆挑战的西蒙东
No full textInternational audienceCet article est la traduction, réalisée par Wenshuo Fan pour le numéro consacré à Simondon par la revue Études de la pensée française, de l'article "L'idée cybernétique de la psychologie : Simondon face au défi de Canguilhem", initialement paru dans la revue Philosophie en 2024
Bi-stable cross-flow pendulum at high Reynolds numbers: experimental investigation and stochastic modelling
No full textInternational audienceThe bi-stable dynamics of a one-degree-of-freedom disk pendulum swept by a flow and allowed to rotate in the cross-flow direction is investigated experimentally. For increasing flow velocity, a subcritical bifurcation is observed from a Pendulum state, characterised by an increasing time-averaged pendulum angle with large amplitude fluctuations, to a rotating state with a non-zero mean rotation velocity at a critical free stream velocity U P2W . The rotating state, referred to as Windmill state, presents a strong hysteresis: once initiated, it is sustained down to velocities U W 2P < U P2W before bifurcating towards the Pendulum state. A thorough experimental characterisation of the dynamical features of each state is reported, with a particular focus on the influence of the static yaw angle of the disk β 0 and the free stream velocity. In the Pendulum state, the system behaves differently depending on whether β 0 lies below or above the stall angle of the disk, with more regular dynamics below. We demonstrate that the bifurcation between the Pendulum state and the Windmill state is triggered by aerodynamic fluctuations, while the bifurcation between the Windmill state and the Pendulum state is deterministic. A stochastic model faithfully reproduces the dynamical features of both states, as well as the characteristics of the bifurcations.</div
UAV Chain Network Creation in Cluttered Environment with Flocking Rules and Routing Data
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Strong sustainability challenges: interrelation between design process and user’s behaviour and impact of rebound effects. Proposal of a theoretical framework
No full textInternational audienceThe sixth IPCC 2023 report indicates that environmental issues have become essential,and that humanity is on an unsustainable social and ecological trajectory. Scientific evidence has shown that purely technocentric approaches that do not question thecurrent economic model remain insufficient to address socio-ecological challenges.However, it’s essential to take into account the behaviour of technology users becausethey play a crucial role in generating ecological impacts and rebound effects. Thiscommunication aims to improve the understanding of the strong sustainabilityparadigm and to suggest elements of attention for the development of a co-designmethodology. In order to propose this new paradigm, we adopt a research methodologybased on a critical review of the literature on strong sustainability at the intersection ofsocial sciences and sustainable design engineering. As a result, three fundamentalelements for understanding strong sustainability were identified: the challenges ofconsumption and user behaviour, rebound effects, and complementary design aspectsfor sustainability. The research’s findings are structured in a framework whose purposeis to suggest challenges for future research and points of attention to consider in thedevelopment of such a strong sustainability co-design method by integrating user behaviours. development of descriptive and prescriptive (co)design methods and toolsfor Strong Sustainability
Tracking fluid sources in mantle wedge jadeitites: Petro-geochemical constraints and implications for fluid venting above the subduction interface
No full textInternational audienceJadeitites are commonly found in serpentinite mélanges and form by fluid flow across the subduction interface. Petrological analysis of jadeitites from various localities (Myanmar, Guatemala, Cuba, Russia, and Iran) coupled with structural characterization enabled the identification of successive jadeite/omphacite generations with subordinate amphibole and mica. These parageneses reflect metasomatism coeval with brittle and/or ductile deformation and complex crosscutting relationships. The composition of fluid inclusions (salinity, gas, δ18O, δD) reveals a wide range of fluid species pointing to a diversity of jadeitite-forming metasomatism. In situ trace element analysis and isotopic measurements (δ11B, 87Sr/86Sr, δ18O) indicate a fluid source dominated by altered oceanic crust (AOC) with a minor sedimentary component. Despite marked changes in major element content during protracted metasomatism, trace elements evolve only moderately while isotopes are virtually homogeneous, recording only small variations of fluid composition over time. Jadeitite evolution is strongly related to the ongoing serpentinization of the mantle wedge, promoting a longer fluid time-residence at the interface associated with chemical exchange and pore-pressure build-up. This suggests that (i) First jadeite generations formed by percolation of highly channelized AOC-derived-fluids in a dry mantle wedge, while later generations record fluid interaction with sediments and the serpentinized mantle. (ii) Fluid pulses across the subduction interface and rheological behavior of the near interface mantle wedge are not controlled by drastic changes in the nature of the slab input, but rather by the cooling of the serpentinizing subduction environment. (iii) The re-use of the same fluid pathways above the slab promotes the re-equilibration of isotopic signatures. (iv) Overpressures may build up upon jadeitite formation and promote brittle deformation events. This may lead to switches in deformation style and variations in permeability, thus changing fluid flow mode along the base of the mantle wedge
Practical realization of chiral nonlinearity for strong topological protection
No full textInternational audienceNonlinear topology has been much less inquired compared to its linear counterpart. Existing advances have focused on nonlinearities of limited magnitudes and fairly homogeneous types. As such, the realizations have rarely been concerned with the requirements for nonlinearity. Here we explore nonlinear topological protection by determining nonlinear rules and demonstrate their relevance in real-world experiments. We take advantage of chiral symmetry and identify the condition for its continuation in general nonlinear environments. Applying it to one-dimensional topological lattices, we show possible evolution paths for zero-energy edge states that preserve topologically nontrivial phases regardless of the specifics of the chiral nonlinearities. Based on an acoustic prototype design with non-local nonlinearities, we theoretically, numerically, and experimentally implement the nonlinear topological edge states that persist in all nonlinear degrees and directions without any frequency shift. Our findings unveil a broad family of nonlinearities compatible with topological non-triviality, establishing a solid ground for future drilling in the emergent field of nonlinear topology
