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Enjeux d'appropriation ? Le devenir des œuvres du 1% artistique
No full textThis text examines the tensions inherent in the appropriation of 1% artworks. In particular, it examines a 1957 sculpture ‘Le lion de Leygue’ that was moved to another campus, tracing its genesis and fate. Based on this case study of a sculpture conceived in a certain architectural, educational and urban environment, we scrutinize these tensions by adding an analysis of other works that did not all suffer the same fate. They have, however, been linked by a form of interdependence, in reference to the notion of “collection”. This notion came into being precisely at the time of the move. Secondly, the text examines the different meanings and uses that have been made of it in relation to questions of appropriation. More specifically, we study the legal qualifications mobilized by actors in reference to “property rights”. Thirdly, we analyze the various types of attachment of works to their environment, which leads us to distinguish different forms of valuing things.Ce texte rend compte des tensions inhérentes aux enjeux d'appropriation autour des œuvres dites du 1% artistique. Il étudie en particulier une sculpture de 1957 (Le lion de Leygue) qui a été déménagée sur un autre campus, en retraçant sa genèse et son devenir. A partir de cette étude de cas autour d'une sculpture conçue dans un certain environnement architectural, éducatif et urbain, nous analysons ces tensions en adjoignant l'analyse d'autres œuvres qui n'ont pas toutes subi le même sort. Elles ont été pourtant liées suivant une forme d'interdépendance, en référence à la notion de « collection ». Cette notion est justement apparue au moment du déménagement. Dans un second temps, le texte examine les différentes significations et les usages qui en a été faits en lien avec les questions d'appropriation. Plus précisément, nous étudions les qualifications juridiques mobilisées par les acteurs en référence à des « droits de propriété ». Dans un troisième temps, nous analysons les divers types d'attache des œuvres à leur environnement, ce qui conduit à distinguer différentes formes de valorisation des choses
<i>N</i> -Acetylcysteine Prevents the Deleterious Effect of Tumor Necrosis Factor-α on Calcium Transients and Contraction in Adult Rat Cardiomyocytes
No full textInternational audienceackground: The negative effect of tumor necrosis factor-alpha (TNF-alpha) on heart contraction, which is mediated by sphingosine, is a major component in heart failure. Because the cellular level of glutathione may limit sphingosine production via the inhibition of the Mg-dependent neutral sphingomyelinase (N-SMase), we hypothesized that cardiac glutathione status might determine the negative contractile response to TNF-alpha.Methods and results: We examined the effects of TNF-alpha in isolated cardiomyocytes obtained from control rats or rats that were given the glutathione precursor N-acetylcysteine (NAC, 100 mg IP per animal). In cardiomyocytes obtained from control rats, 25 ng/mL TNF-alpha increased reactive oxygen species generation and N-SMase activity (500% and 34% over basal, respectively) and decreased the amplitude of [Ca(2+)](i) in response to electrical stimulation (22% below basal). NAC treatment increased cardiac glutathione content by 42%. In cardiomyocytes obtained from NAC-treated rats, 25 ng/mL TNF-alpha had no effect on reactive oxygen species production or N-SMase activity but increased the amplitude of [Ca(2+)](i) transients and contraction in response to electrical stimulation by 40% to 50% over basal after 20 minutes. This was associated with a hastened relaxation (20% reduction in t(1/2) compared with basal) and an increased phosphorylation of both Ser(16)- and Thr(17)-phospholamban residues (260% and 115% of maximal isoproterenol effect, respectively).Conclusions: It is concluded that cardiac glutathione status, by controlling N-SMase activation, determines the severity of the adverse effects of TNF-alpha on heart contraction. Glutathione supplementation may therefore provide therapeutic benefits for vulnerable hearts
Design of a generic hybrid mechanism for hydraulic actuation in humanoid shoulder joints
No full textInternational audienceThis paper introduces a hybrid serial-parallel mechanism developed for the arms of the HYDROïD humanoid robot, aiming to enhance workspace while improving structural stiffness and rigidity. The mechanism is composed of two integrated substructures: a serial chain and a fully parallel subsystem. Although hybrid architectures have been underexplored in humanoid robotics, their combination of serial and parallel advantages presents a promising solution to challenges such as compactness and the varied range of motion required in pitch, yaw, and roll directions. A key design objective is to maintain a slim and anthropomorphic form to facilitate effective and intuitive human-robot interaction. To meet this criterion, the modified Hanavan model was used to determine the geometric and inertial properties of the robot’s upper body, particularly the shoulder mechanism. For initial spatial approximation, the shoulder joint and upper torso were modeled using simplified geometries such as cylindrical cones or bounding parallelepipeds to respect the compact design envelope. These spatial constraints support the use of hybrid architectures over purely parallel configurations. Finally, the kinematic performance of the proposed mechanism is validated through numerical simulations of the workspace and joint torques, demonstrating the feasibility and effectiveness of the hybrid design approach in humanoid robotics
SAIL: Self-supervised Albedo Estimation from Real Images with a Latent Diffusion Model
No full textIntrinsic image decomposition aims at separating an image into its underlying albedo and shading components, isolating the base color from lighting effects to enable downstream applications such as virtual relighting and scene editing. Despite the rise and success of learning-based approaches, intrinsic image decomposition from real-world images remains a significant challenging task due to the scarcity of labeled ground-truth data. Most existing solutions rely on synthetic data as supervised setups, limiting their ability to generalize to real-world scenes. Self-supervised methods, on the other hand, often produce albedo maps that contain reflections and lack consistency under different lighting conditions. To address this, we propose SAIL, an approach designed to estimate albedo-like representations from single-view real-world images. We repurpose the prior knowledge of a latent diffusion model for unconditioned scene relighting as a surrogate objective for albedo estimation. To extract the albedo, we introduce a novel intrinsic image decomposition fully formulated in the latent space. To guide the training of our latent diffusion model, we introduce regularization terms that constrain both the lighting-dependent and independent components of our latent image decomposition. SAIL predicts stable albedo under varying lighting conditions and generalizes to multiple scenes, using only unlabeled multi-illumination data available online
The Methodology of Quantitative Social Intention Evaluation and Robot Gaze Behavior Control in Multiobjects Scenario
No full textInternational audienceThis article focuses on the multiple objects selection problem for the robot in social scenarios, and proposes a novel methodology composed of quantitative social intention evaluation and gaze behavior control. For the social scenarios containing various persons and multimodal social cues, a combination of the entropy weight method (EWM) and gray correlation-order preference by similarity to the ideal solution (GC-TOPSIS) model is proposed to fuse the multimodal social cues, and evaluate the social intention of candidates. According to the quantitative evaluation of social intention, a robot can generate the interaction priority among multiple social candidates. To ensure this interaction selection mechanism in behavior level, an optimal control framework composed of model predictive controller (MPC) and online Gaussian process (GP) observer is employed to drive the eye-head coordinated gaze behavior of robot. Through the experiments conducted on the Xiaopang robot, the availability of the proposed methodology can be illustrated. This work enables robots to generate social behavior based on quantitative intention perception, which could bring the potential to explore the sensory principles and biomechanical mechanism underlying the human-robot interaction, and broaden the application of robot in the social scenario
Plant-PLMview: a web-tool and in silico method for identifying cis-regulatory elements in gene-proximal regions of plants
No full textInternational audiencePlant-PLMview is a web-based tool (plmview.ips2.universite-paris-saclay.fr) that deciphers cis-regulatory motifs close to genes in 20 plant species. A map of gene-proximal regions allows for exploration of these motifs and their co-presences.BackgroundEstablishing relationships between transcription factors and target genes is essential to understandingthe mechanisms regulating gene expression, which play a fundamental role in plant adaptation to thelocal environment. Despite the importance of this research area and the tremendous progress in sequencing methods such as ChIP-seq and DAP-seq, we are still far from a complete reconstruction ofthe cis-regulatory landscape. Experimental data cover only a limited number of transcription factors,underscoring the value of in silico approaches in complementing these studies.ResultsWe developed Plant-PLMview to provide access to the proven method PLMdetect[1,2] for detectingthe enrichment of cis-regulatory elements in the gene-proximal regions of 20 plant species. This webtool allows users to identify preferentially located motifs (PLMs) in the 5’- and 3’-gene-proximal regions of their genes of interest across multiple species simultaneously. Users can query their ownDNA motifs or explore known cis-regulatory sequences from various plant resources such as JASPAR[3].62Results are displayed as a graphical map providing an overview of all PLM locations in the 5’ and 3’-proximal regions of examined genes, along with a table detailing PLM distribution and annotations.ConclusionsPlant-PLMview offers a platform to explore gene regulation across 20 plant genomes. Its originality liesin its curated cis-regulatory sequences and gene-proximal regions the ability to simultaneously analyze both the 5'- and 3’-gene-proximal regions (the latter rarely explored) from multiple species andits PLM map visualization, which facilitates the identification of co-present motifs in multiple geneproximal regions.References1. Rozière J, Guichard C, Brunaud V, Martin ML, Coursol S. A comprehensive map of preferentially located motifs revealsdistinct proximal cis-regulatory sequences in plants. Front Plant Sci. 12 oct 2022;13:976371.2. Tran HC, Schmitt V, Lama S, Wang C, Launay-Avon A, Bernfur K, et al. An mTRAN-mRNA interaction mediatesmitochondrial translation initiation in plants. Science. sept 2023;381(6661):eadg0995.3. Rauluseviciute I, Riudavets-Puig R, Blanc-Mathieu R, Castro-Mondragon JA, Ferenc K, Kumar V, et al. JASPAR 2024: 20thanniversary of the open-access database of transcription factor binding profiles. Nucleic Acids Res. 5 janv2024;52(D1):D174‑82
Le Gantier de Grenoble (1887). Enquêtes sur la fabrique collective au XIXe siècle
No full textInternational audienceThis critical edition of 1865 fieldwork with a glove-making couple in Grenoble offers a cross perspective on the world of fabrique collective and the observational practices through which working-class life was apprehended.Cet ouvrage propose l’édition critique d’une enquête de terrain menée à Grenoble en 1865 auprès d’un couple d’ouvriers gantiers. La revisite de la relation d’enquête offre une perspective croisée sur le monde ouvrier de la fabrique collective et ses observateurs
Normal Rank E‐Order Interval Observer Design for Continuous Linear Time‐Invariant Systems With Unknown Input and Bounded Disturbances
No full textInternational audienceIn this paper, an interval observer for continuous linear time‐invariant systems with unknown input and bounded disturbances is proposed. Usually, the design of such observers is based on the cooperative property of the considered system dynamics, which is hard to satisfy in many cases. To overcome this issue, in a recent work, it has been shown that under some assumptions, the cooperativity of the studied system can be ensured by means of a time‐varying change of coordinates. However, a constructive method for the design of the observer gain, making the observation error dynamics simultaneously positive and stable, is still missing and remains an open problem, especially in the context of unknown input. In this paper, a constructive approach is provided to obtain not only the observer gain but also a new gain that cancels the unknown input of the system and reduces the effect of the bounded disturbances. The proposed approach also allows for estimating the bounds of the unknown input. The efficiency of the proposed methodology is shown through numerical simulations and is compared with simulations resulting from a new method proposed in a recent work
Sequence and Force Effects on ssDNA Translocation through a Protein Nanopore: Coarse-Grained Steered Molecular Dynamics Simulations
No full textInternational audienceProtein nanopores are highly effective for single-molecule studies, especially in the context of single-stranded DNA (ssDNA) translocation. Previous experiments have successfully distinguished between purine and pyrimidine bases and revealed insights into the effect of applied electric voltage on ssDNA translocation dynamics. Unfortunately, the microscopic details of ssDNA translocation over experimental time scales, which are not easily accessible through all-atom molecular dynamics (MD), remain to be further explored. Coarse-grained (CG) MD simulations offer a promising avenue to bridge this gap, allowing simulations over longer time scales closer to the experimental ones. This paper investigates ssDNA translocation through the α-hemolysin (αHL) nanopore using constant-force steered MD with the MARTINI CG force field, building on our previous work validating this approach for ionic and ssDNA transport through this nanopore. We simulated the translocation of poly(dA) and poly(dC) molecules with varying lengths through the αHL nanopore, under different pulling forces to mimic the effect of voltage applied in the experiments. The influence of the sequence and of the magnitude of the pulling force on translocation dynamics is explored. The simulations were run in two replicas for several microseconds for all systems. Our results demonstrate that CG MD simulations efficiently generate statistically significant data and are successful in capturing experimental properties of ssDNA translocation, such as the shorter translocation times of pyrimidine bases over purine and the effect of the applied force. They also provide new insights into the role of DNA conformation dynamics during translocation. Despite the simplification of the CG model, our findings are in accordance with previous experimental and all-atom MD simulation results, underscoring the potential of this model for studying further nanopore systems
Navigating misinformation and disinformation: how definition ambiguity limits the DSA's implementation
No full textInternational audienceVery large online platforms shape public discourse, raising concerns about the impact of misinformation and disinformation on democratic stability. The European Union responded with the Digital Services Act framework. However, its enforcement remains limited, partly due to conceptual ambiguities surrounding the concepts of misinformation and disinformation. This article investigates how definitional inconsistencies undermine the Digital Services Act’s (DSA) implementation. We analyzed 79 documents—including EU legislation, platform policies, fact-checking codes, and academic publications—to examine how key actors define these terms. We identified four key definitional criteria: content quality, intent, associated risk, and creation and dissemination techniques. Our findings reveal that these criteria reflect divergent institutional interests and result in fragmented definitions. This fragmentation generates critical risks, affecting freedom of expression, research, countermeasure design, intervention effectiveness, and impact assessment. We conclude by offering recommendations to support criteria-based definitions, improve risk evaluation, and reinforce the DSA's effectiveness in countering information disorders