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    Observation of W+WγW^{+}W^{-}γ production in pppp collisions at s\sqrt{s} = 13 TeV with the ATLAS detector and constraints on anomalous quartic gauge-boson couplings

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    International audienceThis Letter reports the observation of W+WγW^{+}W^{-}γ triboson production in 140 fb1^{-1} of data collected by the ATLAS detector from proton-proton collisions at a centre-of-mass energy of s\sqrt{s} = 13 TeV at the LHC. Events with an opposite-charge eμ pair, a high transverse-momentum photon, and significant missing transverse momentum are considered. The observed (expected) significance of the signal is 5.9 (6.0) standard deviations. The measured fiducial cross-section, defined for the W+Wγe±μννˉγW^{+}W^{-}γ\to e^{\pm}μ^{\mp}ν\barνγ final state is 6.2 ±\pm 0.8 (stat.) ±\pm 0.6 (sys.) fb, in good agreement with the Standard Model prediction of 6.10.7+1.0^{+1.0}_{-0.7} fb. Constraints on the Wilson coefficients of 13 dimension-8 operators describing physics beyond the Standard Model through anomalous quartic gauge-boson couplings are derived using the effective field theory framework

    Preoperative flexion contracture does not impair outcomes or early revision rates following robotic total knee arthroplasty with functional alignment

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    International audienceAbstract Purpose Preoperative flexion contracture remains a challenging deformity in total knee arthroplasty (TKA). This study aimed to evaluate whether the presence of preoperative flexion contracture influences outcomes and early revision rates following robotic‐assisted TKA performed with functional alignment (FA) principles. Methods This retrospective comparative study analysed 190 patients who underwent robotic‐assisted TKA using a computed tomography‐based FA strategy. Patients were grouped based on intraoperative measurement of flexion contracture: ≥10° (study group; 43 patients) and <10° (control group; 147 patients). Clinical outcomes, intraoperative data, and early revision rates were assessed at a minimum 24‐month follow‐up. Results The study group exhibited significantly more varus alignment intraoperatively and required greater lateral tibial and posterior medial femoral resections. Preoperative knee flexion was lower in the contracture group (110° vs. 120°, p = 0.0018), and postoperative flexion remained slightly reduced (120° vs. 130°, p = 0.05). Flexion contracture at follow‐up was 1° in the study group versus 0° in controls ( p = 0.04). However, no significant differences were observed in Knee Society Scores, Forgotten Joint Score, Kujala score, or early revision rates. All‐cause revision rates were similar (97.67% vs. 98.64%, p = 0.66), with a hazard ratio of 1.85 (95% CI: 0.12–27.72). Aseptic survivorship was 100% in the contracture group versus 99.32% in controls ( p = 0.59). Conclusion Patients with preoperative flexion contracture ≥ 10° achieved comparable mid‐term outcomes and early survivorship to those without contracture following robotic‐assisted TKA using FA. These findings support FA as a reliable strategy to manage complex deformities without the need for soft tissue releases. Level of Evidence Level III

    An intense peak of paraglacial dismantlement of mountain slopes: Insights from dating and volume quantification of rock-slope failure deposits in the Icelandic Westfjords (Dýrafjörður and Önundarfjörður)

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    International audienceParaglacial rock slope failures (RSFs) are prominent processes of landscape evolution in deglaciated terrains, such as the Westfjords of Iceland. This study aims to provide chronological and volumetric data on RSF deposits in the Dýrafjörður and Önundarfjörður fjords, in order to document the magnitude, duration, and geomorphic impact of the intense peak of Early and Middle Holocene paraglacial denudation. By refining the timing of a paraglacial signal, this work contributes to a better understanding of sedimentary production and landscape evolution during the Holocene.A total of 17 RSFs was studied, described and mapped using the Schmidt-hammer exposure-age dating method, calibrated with radiocarbon dating. Surficial block morphometry and volumetric estimates of RSF deposits were derived from field measurements, orthophotography, and high-resolution digital elevation models.RSF ages are concentrated in the Early to Middle Holocene. The vast majority of this activity occurred between 12 and 6 cal. ka BP. During this 6000-year interval, ~83 million m3 of debris were deposited, which accounts for approximately 90% of the total volume (~92.5 M m3) from all 17 RSF sites. This indicates a primary paraglacial adjustment phase characterized by high sediment delivery efficiency. Slope reactivations occurred over periods up to 3400 years, with superimpositions of deposits: these are multi-phased RSFs.Finally, a significant lag of approximately 3000 years is observed between the deglaciation (~10.2 cal. ka BP) and the peak in rock-slope failure activity (8–6 cal. ka BP), which coincides with the Holocene Thermal Maximum climax in Iceland (8.6–5.2 cal. ka BP). The subsequent cessation of major RSFs activity after ~4 cal. ka BP marks the transition to a stable, non-glacial equilibrium

    Investigation of Al-Si-Cu alloys as phase change materials for high temperature thermal energy storage

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    International audienceThe present work explores the suitability of Al-Cu-Si ternary alloys as hightemperature metallic phase change materials (PCMs) for thermal energy storage systems (TESS) operating between 550ºC and 850ºC. While prior research has primarily focused on thermodynamic modeling or thermal property characterization below 600°C, this work provides a comprehensive experimental assessment of selected invariant compositions within the Al-Cu-Si system. CALPHAD calculations were performed using FactSage 8.2 software (SGTE and FTLite database) to guide alloy selection, followed by synthesis and detailed characterization of melting point, latent heat, specific heat, thermal diffusivity, and thermal conductivity. Critically, the thermal reliability of these materials was evaluated under repeated solid-liquid cycling up to 100 cycles in oxidizing atmospheres, revealing their stability and degradation profiles. Additionally, dilatometry and density analysis were conducted to provide an in-depth understanding of the alloys and practical properties for end users. Among the tested alloys, several demonstrated high volumetric energy densities (over 500 kWh/m³ for a temperature difference of 300°C) and good thermal durability, establishing Al-Cu-Si alloys as promising PCM candidates for industrial-scale high-temperature energy storage applications. This study fills a notable gap in the literature by combining phase selection, comprehensive thermophysical property evaluation, and long-term cycling analysis above 600°C

    A comprehensive rock glacier inventory for the Peruvian Andes (PRoGI): dataset, characterization and topoclimatic attributes

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    International audienceAbstract. Rock glaciers are key periglacial landforms in high mountain systems, serving as indicators of permafrost, contributors to mountain hydrology, and sentinels of climate change. Despite their scientific and practical importance, detailed knowledge of their distribution, characteristics, and dynamics in the Peruvian Andes remains limited. This study presents the Peruvian Rock Glacier Inventory (PRoGI v1.0), – a comprehensive inventory of rock glaciers covering the entire Peruvian Andes, encompassing their spatial distribution, morphological attributes, and topoclimatic controls. Unlike previous local-scale studies, PRoGI v1.0 provides national-scale coverage using standardized methods aligned with International Permafrost Association (IPA) guidelines and updated data. Using sub-meter satellite imagery (Bing Maps 2024 and Google Earth 2017) and IPA classification standards, we mapped 2338 rock glaciers with a total area of 94.09 ± 0.05 km2. Approximately 31 % of these landforms were classified as active, 49 % as transitional, and 20 % as relict. They predominantly occur between ∼ 4416 and 5783 m a.s.l. (mean elevation ∼ 4999 m) on slopes averaging ∼ 20.7° (range 7–37°). Spatially, rock glaciers are concentrated in the southern Peruvian Andes, with sparse distribution in central and northern Peru. Most have a southern to southwestern aspect (predominantly S, SW, and SE-facing), and the lower limit of permafrost (indicated by the lowest active rock glacier fronts) is ∼ 3541 m a.s.l. Our inventory serves as a benchmark dataset that significantly advances the understanding and monitoring of mountain permafrost, and it provides a basis for assessing the hydrological importance of rock glaciers in the Peruvian Andes under climate change scenarios. The dataset is available at https://doi.org/10.1594/PANGAEA.983251 (Medina et al., 2025a)

    Regge trajectories for UV completions of graviton scattering from polynomial boundedness

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    International audienceWe study graviton scattering amplitudes. Assuming they are UV completed by a theory of weakly coupled massive higher spins, we demonstrate that the UV completion must possess infinitely many Regge trajectories, and thus they are forced to have a stringy spectrum. We extend and simplify a previous proof by some of us for open-string like states to the case of external gravitons. In the present new proof, we trace the need for infinitely many trajectories to the constraint of polynomial boundedness, ultimately tied to causality. We further present numerical results based on the stringy ansatz of Häring-Zhiboedov, which illustrates how single-trajectory-like solutions actually emerge as extremal solutions of numerical bootstrap. In our numerics, these trajectories curiously show up as numerically very large \textit{sister} trajectories. We provide solid evidence that the solutions are spurious as they appear to admit a divergent limit for infinite ansatz size

    Process evaluation of a school-based vaccination intervention to improve HPV vaccine coverage: A mixed-method study embedded in the French PrevHPV cluster randomized controlled trial

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    International audienceBackgroundHuman papillomavirus vaccine coverage (HPV VC) remains suboptimal in many countries. French authorities launched the PrevHPV research program, which included a cluster randomized controlled trial (cRCT) to evaluate the effectiveness of an ‘at-school vaccination’ intervention. Within this trial, we conducted a process evaluation of this intervention, specifically analyzing (i) its implementation, (ii) its mechanisms of impact, and (iii) the contextual factors influencing implementation (facilitators/barriers).MethodWe conducted a mixed-method study embedded in the PrevHPV cRCT (April 2021–April 2022). ‘At-school vaccination’ consisted of vaccination day(s) on school premises where mobile vaccination teams (MVTs) initiated HPV vaccination free of charge for eligible adolescents (i.e., non-vaccinated adolescents aged 11+). Quantitative data were collected through activity reports and self-administered questionnaires of adolescents and school staff. Qualitative data collected through six focus groups with school staff and MVTs were analyzed using thematic analysis.ResultsOf the 31 schools (14,772 adolescents) randomized to implement ‘at-school vaccination’, 12 (39 %) dropped out. Among the participating schools, analysis of implementation showed that 17 % of adolescents returned valid consent forms, of whom 89 % initiated vaccination. MVTs played a central role in implementing vaccination day(s), supported by several school staff (e.g., school nurses, education assistants). Regarding mechanisms of impacts, satisfaction with the vaccination days was high among adolescents and school staff. The intervention generated both positive and negative group effects among adolescents. Contextual factors that facilitated implementation included the preparation of a list of adolescents to be vaccinated and the availability and motivation of school staff. The main barriers related to the management of consent forms and missing health records.ConclusionWe formulated recommendations for implementing at-school vaccination, which may be particularly helpful for the French school HPV vaccination campaigns that were scaled up nationally in 2023. We also discussed potential macro-level improvement strategies, involving modifications to the legislative framework

    Across ancient oceans: Eocene dispersal routes of Asian terrestrial mammals to Europe, Afro-Arabia and South America

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    International audienceDuring the middle and late Eocene, Asian terrestrial mammals dispersed to Europe, while primates and rodents dispersed across the 500-to-2000 km wide Neotethys Ocean and the 1500-to-2000 km wide Atlantic Ocean to colonize Afro-Arabia and South America. This study explores how these mammals have achieved such remarkable and enigmatic dispersals. We present high-resolution paleogeographic models for the middle to late Eocene based on updated plate kinematic reconstructions, paleo-bathymetry and paleo-topography data. With this, we evaluate landmass configurations and connectivity that may have facilitated faunal exchanges from Asia toward Europe, Afro-Arabia, and South America and discuss dispersal mechanisms between these biogeographic provinces. Our reconstructions reveal that during the Bartonian (~40–38 Ma), an overland dispersal corridor between Asia and Balkanatolia became available to terrestrial mammals and acted as a pivotal pathway for Asian faunas dispersing toward western Europe and Afro-Arabia. We identified two Balkanatolian island-hopping routes across the Western Neotethys potentially enabling the dispersal of small-bodied Asian primates, rodents and artiodactyls to Afro-Arabia. Alternatively, these taxa may have rafted across the Central Neotethys. By ~34 Ma, Balkanatolia fully connected with Western Europe, opening a southern “Grande Coupure” route for Asian faunas. In the Atlantic, we identify long-distance rafting as the most plausible mechanism for the 40–34 Ma transoceanic dispersal of the Asian-originated primates and rodents from Afro-Arabia to South America despite the likely presence of sparse islands along the Walvis Ridge and the Rio Grande Rise

    Progrès. Parcours, Analyses, Plaidoyer

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