HAL Université de Savoie
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Natural Risk assessment and management in Hexagonal France and Europe
No full textInternational audienceHexagonal France’s diverse geography, from mountains to coastlines, contributes to a high prevalence of natural risks, affecting most of the population. Climate change is exacerbating these risks, with rising temperatures leading to more frequent and intense events like heatwaves, storms, floods, and wildfires. In this paper, we detail specific risks in Hexagonal France. Coastal Risks: erosion, flooding, and storms threaten coastal areas, driven by rising sea levels and human activity. Mountain Risks: the Alps and Pyrenees experience heavy rainfall, increasing the risk of floods and landslides. Other Risks: wildfires are a major concern in southern France, while earthquakes and tsunamis pose threats, particularly in the Mediterranean region. France has a risk management framework involving prevention plans, local and national response coordination, and civil protection forces. However, the increasing frequency and severity of these events, coupled with budget constraints, necessitate a rethinking of risk prevention policies and better integration of scientific knowledge and socioeconomic factors. International cooperation, particularly within the Euro-Mediterranean region and the EU, is crucial for addressing these shared vulnerabilities
Art digital et mémoire traumatique
No full textInternational audienceThis lecture discusses the artist's digital works, exploring how personal experiences of incest influence her artistic approach and sensory perceptions. The notion of the device, central to her approach, allows us to examine the diversity of memory narratives and the impact of trauma on our perception of the world. She does not tell my story, but creates devices to test these machines and attempt to reveal sensitive spaces that show how she perceives and feels the world. These are special spaces in which memories are invented and spectres (bugs) lodge themselves, the result of which is visible in the image.Cette conférence aborde les œuvres numériques de l'artiste, explorant la manière dont ses expériences personnelles d'inceste influencent son approche artistique et ses perceptions sensorielles. La notion de dispositif, centrale dans son approche, nous permet d'examiner la diversité des récits mémoriels et l'impact des traumatismes sur notre perception du monde. Elle ne raconte pas mon histoire, mais crée des dispositifs pour tester ces machines et tenter de révéler des espaces sensibles qui montrent comment elle perçoit et ressent le monde. Ce sont des espaces particuliers dans lesquels les souvenirs sont inventés et où des spectres (insectes) s'installent, dont le résultat est visible dans l'image
Impact of positive airway pressure for chronic hypercapnic respiratory failure on sleep quality: a systematic review and meta-analysis
No full textInternational audienceBackground Positive airway pressure (PAP) including noninvasive ventilation or continuous PAP are standard of care in chronic hypercapnic respiratory failure (CHRF). PAP is applied during sleep so its impact on sleep quality and daytime sleepiness is relevant. This systematic review and meta-analysis investigated the effects of PAP for CHRF on sleep quality. Methods Relevant studies were identified by a PubMed/Embase search up to October 2024. Eligible studies included PAP initiation and evaluation of sleep quality/sleepiness. Evaluated outcomes were sleep efficiency, Pittsburgh Sleep Quality Index (PSQI), Severe Respiratory Insufficiency sleep subscale (SRI-AS) and Epworth Sleepiness Scale (ESS). Results 58 studies were included (n=2511; mean age 59.1 years, 57% male) and the indication for PAP was obesity hypoventilation syndrome (n=1073), neuromuscular disease (NMD) (n=649), COPD (n=428) or other/mixed aetiologies (n=361). Overall improvements were +5.87% (95% CI 2.64–9.09) for sleep efficiency, −2.51 (95% CI −3.22–−1.80) for PSQI, +10.75 (95% CI 6.11–15.40) for SRI-AS score and −4.96 (95% CI −5.96–−3.97) for ESS score. Adherence to PAP was the only factor significantly associated with sleep efficiency improvement. ESS and PSQI improved to a greater extent in people with a higher body mass index, younger age and hypercapnia correction during PAP. ESS improvement was associated with sleep efficiency improvement. PSQI improved to a greater extent in females and those with NMD. Conclusion PAP initiation was associated with clinically relevant objective and subjective sleep quality improvements. Given the health benefits of good sleep, the effect of sleep quality improvements during PAP on prognosis should be investigated
Moduler la prise de raquette pendant l’imagerie motrice influence la précision et la performance du service en tennis : une étude pilote
No full textInternational audienceThere is now ample evidence that Motor Imagery (MI) contributes to improve motor performance. Previous studies provided evidence that its effectiveness remains dependent upon specific guidelines and recommendations. The body posture, as well as the context in which MI is performed, are notably critical and should be carefully considered. The present study in young tennis players (n=18) was designed to compare the effectiveness of performing MI of the serve while adopting a loose grip (congruent MI) or holding tightly and squeezing hard the racket (incongruent MI). Data revealed that both MI conditions contributed to enhance the number of successful serves (p<0.001) and the technical quality of the serve (p<0.001). Interestingly, comparing mean serve accuracy scores showed that performance gains were significantly higher in the loose MI group than in the tight MI group (p<0.02). These findings confirm the critical importance of the congruence between the content of the mental representation and the features of the corresponding actual movement. Overall, the present study further highlights the effectiveness of the loose grip while mentally rehearsing the serve, and might thus contribute to update and adjust specific MI guidelines and recommendations.La contribution de l’imagerie motrice (IM) à l’amélioration des performances est désormais bien établie, bien qu’assujettie à des préconisations d’usage et consignes de pratique spécifiques. En particulier, la position et le contexte dans lequel l’IM est effectuée exercent une influence sur sa qualité et son efficacité. L’objectif de cette étude chez de jeunes joueurs de tennis (n=18) était de comparer l’efficacité de deux conditions d’imagerie motrice (IM) : une condition compatible où le joueur imagine son service en tenant la raquette de manière relâchée (IM de relâchement), et une condition incompatible où il imagine tenir la raquette fermement pour créer une tension musculaire (IM de contraction). Les données ont montré que les deux conditions d’IM contribuaient à améliorer le taux de réussite (p<0.001) et la qualité technique du geste de service (p<0.001). En revanche, le score de précision moyen du service était significativement plus élevé après l’IM de relâchement (p<0.02), confirmant l’importance de la compatibilité entre contenu des représentations mentales et exigences de la pratique réelle. Ces données soulignent ainsi l’efficacité du relâchement de la main et permettent d’affiner les consignes liées au travail mental chez les jeunes joueurs de tennis
Exploring the Kinetics and the Phase Diagram of Individual Pd Nanoparticles during Hydrogen Absorption
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Geometry of Gauss digitized convex shapes
No full textInternational audienceThis paper studies how well we can infer the geometry of a (smooth or not) convex shape X from the convex hull Y h of its Gauss digitization with a given gridstep h. Without smoothness constraint, we first present results concerning the proximity of facet normal vectors to the shape normal vectors, as well as a relation between the number of lattice points just above a facet and its area. Then, further results can be obtained when X is smooth, that are valid in arbitrary dimension d. More precisely, we show that the boundary of Y h is Hausdorff-close to the boundary of X with distance less than √ dh, and that the vertices of Y h are even much closer (some O(h^(2d /d+1))). Finally we show that the geometric normal vectors to the facets of Y h tend to the smooth shape normals with a speed O(h^1/2 ), and the bound is tight
The Regge bootstrap, from linear to non-linear trajectories
No full textInternational audienceWe present a numerical linear programming bootstrap to construct dual model scattering amplitudes. Dual models describe tree-level exchanges of higher spin resonances in theories like string theory and large gauge theories. Despite being very simple objects, their numerical bootstrap has proven challenging due to slow convergence of the infinite sums over resonances. Our bootstrap succeeds thanks to an efficient parametrization of the amplitude in terms of Mandelstam-Regge poles and the use of combined regions that make crossing symmetry constraining. Along the way, we discover and conjecture a property of "super-unitarity" of the Veneziano amplitude, which we use to keep a linear problem. As results, we present first the study of a class of string-like amplitudes with linear trajectories, for which we observe that the Veneziano amplitude lies at a preferred location, at the bottom of a pit, which minimizes crossing. Then, we introduce a toy-model deformation to non-linear trajectories, mimicking some features of QCD, for which our algorithm also detects a clear pit. This gives compelling evidence that our bootstrap is able to produce amplitudes that can exhibit non-trivial phenomenological features
Test of lepton flavor universality in semileptonic B meson decays in proton-proton collisions at = 13 TeV
No full textInternational audienceA measurement of the ratio of branching fractions (J/) = (B J/)/(B J/) in the J/, decay channel is presented. This measurement uses a sample of proton-proton collision data collected at a center-of-mass energy of 13 TeV by the CMS experiment in 2018, corresponding to an integrated luminosity of 59.7 fb. The measured ratio, (J/) = 0.17 (stat) (syst) (theo) = 0.17 0.33, agrees with the value of 0.2582 0.0038 predicted by the standard model, which assumes lepton flavor universality
Measurement of the H and tH production rates in the H decay channel using proton-proton collision data at = 13 TeV
No full textInternational audienceAn analysis of the production of a Higgs boson (H) in association with a top quark-antiquark pair (H) or a single top quark (tH) is presented. The Higgs boson decay into a bottom quark-antiquark pair (H ) is targeted, and three different final states of the top quark decays are considered, defined by the number of leptons (electrons or muons) in the event. The analysis utilises proton-proton collision data collected at the CERN LHC with the CMS experiment at = 13 TeV in 2016-2018, which correspond to an integrated luminosity of 138 fb. The observed H production rate relative to the standard model expectation is 0.33 0.26 = 0.33 0.17 (stat) 0.21 (syst). Additionally, the H production rate is determined in intervals of Higgs boson transverse momentum. An upper limit at 95% confidence level is set on the tH production rate of 14.6 times the standard model prediction, with an expectation of 19.3. Finally, constraints are derived on the strength and structure of the coupling between the Higgs boson and the top quark from simultaneous extraction of the H and tH production rates, and the results are combined with those obtained in other Higgs boson decay channels