HAL Portal de Univ. Gustave Eiffel
Not a member yet
72847 research outputs found
Sort by
Image-based robotic-assisted conversion from partial to total knee arthroplasty under functional alignment: Comparable outcomes to primary total knee arthroplasty
No full textInternational audienceIntroduction : Image-based robotic systems in total knee arthroplasty (TKA) allow for precise implant positioning and soft tissue balance through patient-specific preoperative planning. Functional alignment (FA) leverages the native soft tissue envelope to guide implant placement. However, its application in partial TKA conversion remains limited. This study evaluates the outcomes of image-based robotic-assisted partial-to-TKA conversion under FA principles, comparing them to a cohort of primary robotic TKAs. Methods : This retrospective study analyzed eight partial-to-TKA conversions performed using the image-based robotic system, with a minimum follow-up of 12 months. Demographics, implant constraints, intraoperative positioning, and postoperative outcomes were assessed. The mean age of the revision cohort was 73.3 ± 9.0 years, with a mean follow-up of 39.0 ± 11.5 months. A control group of 50 primary robotic TKAs was used for comparison. Results : Osteoarthritis progression (75%) and aseptic loosening (25%) were the primary reasons for revision. No stems were used, and only one patient (12.5%) required a tibial augment. Postoperative coronal alignment was 1.1° ± 1.9°, and functional outcomes (Knee Society Score-Knee: 84.5 ± 6.7, Knee Society Score-Function: 83.0 ± 7.1, Forgotten Joint Score: 72.8 ± 8.2) were comparable to the primary TKA cohort. No complications or revisions were recorded. Conclusion : FA-based robotic-assisted partial-to-TKA conversion yields functional and implant positioning outcomes comparable to primary robotic TKA while minimizing the need for stems, augments, or constrained implants. Further studies with larger cohorts are needed to confirm these findings. Level of evidence : III
Qu’est-ce qui remplit les salles de concerts ? La nostalgie, pardi !
No full texthttps://theconversation.com/quest-ce-qui-remplit-les-salles-de-concerts-la-nostalgie-pardi-272744Sur les scènes françaises, les tournées « best of » ou les « tribute bands » occupent le terrain, remplissent les salles et structurent un véritable marché de la « nostalgie live ». Portés par une demande de réconfort émotionnel et de communion mémorielle, ces spectacles du passé remixés au présent interrogent. Comment comprendre un tel engouement pour ces pastiches et jusqu’où cette économie de la copie peut-elle prospérer sans trop étouffer la création
De la production à l'exploration : la “danse infernale” de la coopération inter-organisation
No full textInternational audienceL'article « De la production à l'exploration : la “danse infernale” de la coopération inter-organisation » propose une analyse de la série Étoile (Sherman-Palladino & Palladino, 2025) comme terrain d'observation du management dans les organisations artistiques hybrides. À travers l'échange de talents entre le Ballet National de l'Opéra de Paris et le Metropolitan Ballet Theater de New York, il explore comment un dispositif de coopération, d'abord pensé comme un partenariat de production destiné à renforcer la performance financière, glisse progressivement vers un partenariat d'exploration (Segrestin, 2006). Ce glissement transforme la nature des relations inter-organisationnelles et des processus de création, révélant les tensions identitaires, managériales et symboliques propres aux organisations hybrides (Battilana & Dorado, 2010). Ces tensions remettent en question les philosiophies gestionaires initiales de l'échange de talents et contribue à une profonde transformation de la raison d'être des deux compagnies de danse
Predicting seat pan angle for eliminating the shear on the seat pan using a musculoskeletal human model
No full textInternational audienc
EZ-SP: Fast and Lightweight Superpoint-Based 3D Segmentation
No full textSuperpoint-based pipelines provide an efficient alternative to point- or voxel-based 3D semantic segmentation, but are often bottlenecked by their CPU-bound partition step. We propose a learnable, fully GPU partitioning algorithm that generates geometrically and semantically coherent superpoints 13x faster than prior methods. Our module is compact (under 60k parameters), trains in under 20 minutes with a differentiable surrogate loss, and requires no handcrafted features. Combine with a lightweight superpoint classifier, the full pipeline fits in <2 MB of VRAM, scales to multi-million-point scenes, and supports real-time inference. With 72x faster inference and 120x fewer parameters, EZ-SP matches the accuracy of point-based SOTA models across three domains: indoor scans (S3DIS), autonomous driving (KITTI-360), and aerial LiDAR (DALES). Code and pretrained models are accessible at github.com/drprojects/superpoint_transformer
Microplastics quantification in organic-rich samples: the relevance of testing substrate-specific calibration curves
No full textInternational audienceUrban agriculture could rely on waste-based substrates, but potential contaminants such as microplastics should be evaluated for safe public use. However, quantifying macroplastics in these substrates is challenging due to their high organic matter content, which is difficult to remove completely, leading to interfering compounds and unreliable results. This study investigated the underexplored effects of organic matter on microplastics quantification employing pyrolysis-GC-MS. Natural organic matter (NOM) removal methods were tested on organic-rich peat-based substrate, reaching up to 46% of reduction with Fenton’s reaction. Then, calibration curves were prepared in two inorganic matrices, silicon dioxide and glass fiber powders, for high density polyethylene (HDPE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC) across nine concentrations, from 0.01 to 10 µg/mg, adding polyflurostyrene (PFS) as internal standard. The selectivity of several polymer pyrolytic markers was compared. Polymer-spiked samples were subjected to Fenton’s oxidation and quantified with both inorganic calibration curves, overestimating polymer contents, up to four times for PET and PVC. The preparation of a third calibration curve, specific for peat, improved results for PS, but not for PP, PET, and PVC. For the first time, the three calibration curves were tested on untreated polymer-spiked (HDPE, PP, PS) waste-based substrates, and resulted in a better estimation closer to the expected polymer concentrations when substrates closely matched the curve’s matrix composition. The comparison of three calibration curves made with different matrices showed that the quantification of plastic polymers in organic-rich samples could be improved using matrix-specific calibration curves even without a complete NOM removal. This represents a novel methodological approach for plastic polymers quantification in complex matrices, minimizing the sample pre-treatment that could cause the loss of nanoparticles during filtration, evidencing that matrix similarity is key for reliable quantification in NOM-rich samples, even without its complete removal
Maduro-Trump : la bataille pour imposer un récit légitime
No full textThe conversation https://theconversation.com/maduro-trump-la-bataille-pour-imposer-un-recit-legitime-273031This article analyzes the arrest of former Venezuelan president Nicolás Maduro as a global informational crisis beyond its legal and geopolitical dimensions. It shows how the event rapidly became a confrontation of competing narratives seeking to establish political legitimacy. Drawing on information and communication sciences, the author highlights the central role of institutions, media, and digital platforms in meaning-making, perception polarization, and the rise of cognitive warfare based on competing regimes of truth.Cet article analyse l’arrestation de l’ancien président vénézuélien Nicolás Maduro comme une crise informationnelle globale, au-delà de ses dimensions juridiques et géopolitiques. Il montre comment l’événement s’est immédiatement transformé en une confrontation de récits concurrents visant à produire de la légitimité politique. À travers une approche en sciences de l’information et de la communication, l’auteur met en lumière le rôle central des médias, des institutions et des plateformes numériques dans la construction du sens, la polarisation des perceptions et l’émergence d’une guerre cognitive fondée sur la concurrence des régimes de vérité
Les réseaux au secours de l'innovation sociale. Retour d'expérience.: Première restitution du "Civic Imagination Living Lab" de juin 2024 à Bowling Green, Kentucky, Etats-Unis.
No full textNetworks to the Rescue of Social Innovation: First findings from the workshop "Civic Imagination Living Lab", held in June 2024 in Bowling Green, Kentucky, United States. Presentation as part of the ADIMAP workshop at the International Symposium in Public Management, June 2025: Le Management Public à l'Epreuve des Réseaux.Les réseaux au secours de l’innovation sociale, première restitution de l'atelier expérimental, "Civic Imagination Living Lab" de juin 2024 à Bowling Green, Kentucky, Etats-Unis. Présentation dans le cadre de l'atelier ADIMAP du Symposium International, juin 2025 : Le Management Public à l'Epreuve des Réseaux
Converting Liminal Uncertainty into Collective Agency: A Futures Literacy Lab in Maré, Rio de Janeiro
No full textApproximate Message Passing for General Non-symmetric Random Matrices
No full textInternational audienceApproximate Message Passing (AMP) algorithms are a family of iterative algorithms based on large random matrices with the special property of tracking the statistical properties of their iterates. They are used in various fields such as Statistical Physics, Machine learning, Communication systems, Theoretical ecology, etc.In this article we consider AMP algorithms based on non-Symmetric random matrices with a general variance profile, possibly sparse, a general covariance profile, and non-Gaussian entries. We hence substantially extend the results on Elliptic random matrices that we developed in [GHN24]. From a technical point of view, we enhance the combinatorial techniques developed in Bayati et al. [BLM15] and in Hachem [Hac24]. Our main motivation is the understanding of equilibria of large food-webs described by Lotka-Volterra systems of ODE, in the continuation of the works of Hachem [Hac24], Akjouj et al. [AHM 24] and Gueddari et al. [GHN24], but the versatility of the model studied might be of interest beyond these particular applications.</p