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Predicting thermal conductivity and associated autocorrelation function for simple fluids
No full textInternational audienceThis work is a continuation of my thesis work aimed at modeling the transport properties of fluids over the entire phase diagram.Here, the focus is on thermal conductivity. Existing models, such as those based on the Green-Kubo and Egorov formalism [1], which we recently applied to predict shear viscosity and the self-diffusion coefficient [2], are very efficient, but too complex to implement to model thermal conductivity. We therefore propose a simpler alternative, drawing on similarities with shear viscosity to calculate thermal conductivity and its associated autocorrelation function
Validation of a markerless motion capture system for centre of mass kinematic analysis
No full textInternational audienceIn recent years, markerless optical systems for biomechanical movement analysis in sports, gait and balance assessments are being used as an alternative to conventional marker based measuring systems. This study compares the performance of the Zed 2i stereoscopic camera against a VICON system in a standing position under three conditions: quiet standing and two movements simulating disturbances in two directions, anteroposterior and mediolateral. This study originates from a collaborative project with a medical team that aims to objectively evaluate balance function in patients recovering from stroke. The displacement and velocities of the centre of mass were calculated and compared in two directions, x and y. A Bland–Altman analysis for non-parametric data, along with the coefficient of determination and mean square error, were used for statistical evaluation. The results demonstrate that the limits of agreement in both sway tasks were greater than those observed in static conditions. However, the coefficient of determination of the sway tasks indicates a significant degree of agreement between the two systems. In contrast, in the static condition, it appears that noise may have a greater influence on the signal than the centre of mass estimate, due to the limitation of the depth algorithm used to estimate the joint positions
Exponential equidistribution of periodic points for endomorphisms of
No full textLet be a holomorphic endomorphism of of algebraic degree . We show that the periodic points of of period equidistribute towards the equilibrium measure of exponentially fast as tends to infinity. This quantifies a theorem of Lyubich for and of Briend-Duval for . A byproduct of our proof is the existence of a large number of periodic cycles in the small Julia set with large multipliers
Le ministre condamné et le « juge rouge »
No full textInternational audienceÉtat de droit vs démocratie en Itali
Weak trunk extensors in adult spinal deformity patients are related to sagittal malalignment and kinematic limitations
No full textInternational audienceBackground: Adult spinal deformity (ASD) is associated with muscles' degeneration that affects postural control and outcomes of an eventual corrective surgery. Evaluation of ASD is usually based on static radiographs and more recently on functional assessment. However, there has been limited exploration of muscle strength weakness in ASD. The aim was to investigate the relationship between trunk muscles' strength in ASD and its relationship with radiographic and kinematic alterations and quality-of-life decline.Methods: 28 ASD and 18 asymptomatic subjects underwent biplanar radiographs with 3D calculation of spino-pelvic and global postural parameters. 3D movement analysis of gait, sitting to standing and stair ascent, was studied allowing the calculation of head, trunk and lower limbs 3D kinematics. Participants filled out health related quality of life questionnaires. A single operator measured 4 times the strength of the trunk muscles, using a hand-held dynamometer, to assess measurements' reliability. ASD population was divided into two groups based on the strength of trunk extensors: ASD-weak extensors (N = 11 patients having trunk extensors strength0.94). On standing radiographs, the ASD-weak extensors group showed an increased positive sagittal malalignment compared to the other groups (SVA=61 mm vs ASD-normal extensors: 18 mm, controls: -4 mm, p < 0.001). This sagittal malalignment remained during movement (kinematic-SVA=223 mm vs ASD-normal extensors:178 mm, controls:138 mm, p < 0.001). Muscle strength weakness was correlated to the decline of quality-of-life scores (PCS-SF36: r = 0.48, VAS for pain: ρ=-0.39).Conclusions: This study showed that weak trunk extensors are associated with sagittal malalignment in static position, kinematic limitations during daily life activities and reduced quality of life scores. Future studies will investigate the effect of muscle strengthening on both static and dynamic alignment in ASD and their quality of life
Clustering multi-vues de documents selon un mécanisme de cross-attention pour la fusion de caractéristiques
No full textInternational audienceL’augmentation croissante de la quantité de documents complexes renforce le besoin de modèles capables de traiter efficacement ce type de données multivues, où plusieurs types d’informations coexistent. Les approches classiques, traitant soit les caractéristiques textuelles et visuelles séparément, soit proposant une fusion simple des différents espaces de représentation, ne tirent pas pleinement parti de leur complémentarité. Cet article propose une méthode innovante pour fusionner ces caractéristiques via un mécanisme de cross-attention(Vaswani et al., 2017), utilisant LayoutLM (Xu et al., 2020) pour le texte et Vision Transformer (ViT) (Dosovitskiy et al., 2021) pour les informations visuelles (images, graphes,...). Cette intégration enrichit significativement la compréhension des documents et la performance de l’extraction d’informations, en particulier pour des documents complexes tels que les contrats, les formulaires ou les rapports financiers. Nous démontrons expérimentalement l’efficacité de cette approche pour le clustering de documents, avec des améliorations notables selon diverses métriques d’évaluation de clustering, en comparaison avec les modèles unimodaux et multimodaux existants
Association between cardiovascular risk factors and the occurrence of giant cell arteritis: a systematic review and meta-analysis
No full textInternational audienceAbstract Objectives We aimed to analyze the association between cardiovascular risks factors and the onset of giant cell arteritis (GCA) through a systematic review and meta-analysis of observational studies. Methods Three databases (MEDLINE, EMBASE, WEB OF SCIENCE) were systematically reviewed. Epidemiological studies on the association between six cardiovascular risk factors (type 2 diabetes, hypertension, dyslipidaemia, smoking, overweight/obesity, history of a cardiovascular disease) and the risk of GCA were eligible. Risk of bias was assessed using the ROBINS-E scale. Pooled associations for studies assessing the same outcome were reported as odds ratios (OR) and their 95% confidence interval (CI). Results The search strategy identified 4,210 references, of which 43 studies were analyzed and 17 were included in the meta-analysis (11 case-control studies, four cohort studies). An inverse association was found between type 2 diabetes and risk of GCA (OR = 0.75, 95% CI 0.61–0.93) and whereas history of cardiovascular disease was positively associated with GCA with risk (OR = 1.28, 95% CI 1.18–1.38). We found a trend towards a decreased risk of GCA in overweight participants (OR 0.64; 95% CI 0.41–1.00). Conclusion Our study showed an inverse association of type 2 diabetes and a positive association of a history of cardiovascular disease with GCA risk. There is also a trend towards an inverse association with overweight. The pathophysiological mechanisms underlying these findings may involve an effect of cardiovascular risk factors themselves, a condition underlying these factors such as diet, or a condition following their diagnosis such as their treatment
Interaction entre exposition aux moisissures de l'air intérieur et tabac sur l'asthme et la rhinite : la cohorte CONSTANCES
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