Portail des publications scientifiques IMT Mines Alès
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Nouvelles voies de fonctionnalisation de fibres naturelles
No full textThis thesis project proposes new approaches to improve the properties of flax textiles in abroad area of applications.For the first time, a silazane-based molecule was exploited to functionalize flax fibers withvinyl groups, thereby creating covalent bonds with a silicone matrix. This approachstrengthens the compatibility between flax textiles and a hydrophobic matrix.“Grafting to” and “Dip-coating” methods were used to give textiles hydrophobic and self-cleaning properties, thanks to a catalysed hydrosilylation reaction using different siloxanemolecules.Finally, flax textiles are flame retarded using phytic acid as a flame retardant. The textilesare first functionalized with glycidyl groups and then subjected to phytic acid treatment.Overall, these different methods offer promising prospects for the improvement of flaxtextiles in varied applications, ranging from silicone composites to hydrophobic textiles andflame-retardant materials.Ce projet de thèse propose de nouvelles approches pour améliorer les propriétés des textilesde lin pour diverses applications.Pour la première fois, une molécule de silazane a été utilisée pour fonctionnaliser les fibresde lin avec des groupes vinyles, permettant ainsi de créer des liaisons covalentes avec unematrice de silicone. Cette approche améliore la compatibilité et renforce la compatibilitéentre les textiles de lin et une matrice hydrophobe.Des méthodes de "Grafting to" et "Dip-coating" ont été utilisées afin de conférer aux textilesdes propriétés hydrophobes et auto-nettoyantes, grâce à une réaction d'hydrosilylationcatalysée en utilisant différentes molécules à base de siloxanes.Enfin, les textiles de lin ont été rendus ignifuges en utilisant l'acide phytique comme agentretardateur de flamme. Les textiles sont d'abord fonctionnalisés avec des groupes glycidyle,puis soumis à un traitement à l'acide phytique.Ces différentes méthodes offrent des perspectives prometteuses pour l'amélioration destextiles de lin dans des applications variées, allant des composites de silicone aux textileshydrophobes et aux matériaux ignifuges
Progression of clinical markers in prodromal Parkinson’s disease and dementia with Lewy bodies: a multicentre study
No full textInternational audienceThe neurodegenerative synucleinopathies, including Parkinson's disease and dementia with Lewy bodies, are characterized by a typically lengthy prodromal period of progressive subclinical motor and non-motor manifestations. Among these, idiopathic REM sleep behaviour disorder is a powerful early predictor of eventual phenoconversion, and therefore represents a critical opportunity to intervene with neuroprotective therapy. To inform the design of randomized trials, it is essential to study the natural progression of clinical markers during the prodromal stages of disease in order to establish optimal clinical end points. In this study, we combined prospective follow-up data from 28 centres of the International REM Sleep Behavior Disorder Study Group representing 12 countries. Polysomnogram-confirmed REM sleep behaviour disorder subjects were assessed for prodromal Parkinson's disease using the Movement Disorder Society criteria and underwent periodic structured sleep, motor, cognitive, autonomic and olfactory testing. We used linear mixed-effect modelling to estimate annual rates of clinical marker progression stratified by disease subtype, including prodromal Parkinson's disease and prodromal dementia with Lewy bodies. In addition, we calculated sample size requirements to demonstrate slowing of progression under different anticipated treatment effects. Overall, 1160 subjects were followed over an average of 3.3 ± 2.2 years. Among clinical variables assessed continuously, motor variables tended to progress faster and required the lowest sample sizes, ranging from 151 to 560 per group (at 50% drug efficacy and 2-year follow-up). By contrast, cognitive, olfactory and autonomic variables showed modest progression with higher variability, resulting in high sample sizes. The most efficient design was a time-to-event analysis using combined milestones of motor and cognitive decline, estimating 117 per group at 50% drug efficacy and 2-year trial duration. Finally, while phenoconverters showed overall greater progression than non-converters in motor, olfactory, cognitive and certain autonomic markers, the only robust difference in progression between Parkinson's disease and dementia with Lewy bodies phenoconverters was in cognitive testing. This large multicentre study demonstrates the evolution of motor and non-motor manifestations in prodromal synucleinopathy. These findings provide optimized clinical end points and sample size estimates to inform future neuroprotective trials
FORT: Fisheye Online Realtime Tracking with an Improved Kalman Filter
No full textInternational audienceThe goal of human tracking is to detect people in ascene and assign them a unique identifier that the tracker willfollow across multiple frames. Our tracker, FORT, implementsdeep learning solutions such as, YOLOv7 for detection, ResNeXt-50 for feature extraction and re-identification and an adaptedKalman filter for tracking. The goal is to present a real timetracking solution for the complex environment of top-view, fisheyeimages. The proposed solution is then compared with the BoTSORTand StrongSORT trackers on a custom fisheye MultipleObject Tracking (MOT) Challenge datase
Traitement des interfaces PLA/Lin et PLA/Bambou : rendre possible les vies successives des biocomposites
No full textInternational audienc
Five-Factor Model Personality Traits and the Trajectory of Episodic Memory: Individual-Participant Meta-Analysis of 471,821 Memory Assessments from 120,640 Participants
No full textInternational audienceObjectives: Five-factor model (FFM) personality traits are associated with concurrent memory function and risk of incident dementia but are less consistently associated with the change in episodic memory. The present research analyzes multiple large-scale studies with a consistent analytic approach to evaluate the association between personality and change in episodic memory over time. Method: Across nine public longitudinal data sets, 120,640 participants provided 471,821 memory assessments over up to 26 years (age range 18–108). FFM traits were tested as predictors of the average level (intercept) and change over time (slope) of episodic memory. Results from the individual samples were meta-analyzed to summarize the associations. Results: Consistent with expectations for the intercept, higher neuroticism was associated with worse memory performance, whereas higher openness and conscientiousness were associated with better performance; extraversion and agreeableness were also associated with better performance. Higher neuroticism and lower conscientiousness were related to declines in memory only in samples with more than two assessments of memory. The other three traits were unrelated to memory slope. The pattern was similar when participants with dementia were excluded from the analysis, and the association with the slope was not moderated by age. Discussion: FFM traits have a robust association with average memory performance. Higher neuroticism and lower conscientiousness were associated with declines in memory performance only among samples with more than two memory assessments. The heterogeneity across studies suggests that multiple memory assessments are needed to reliably detect change over time, which may be one reason for past inconsistencies across studies
EXPLORING THE DYNAMICS OF VERBAL AND NONVERBAL COMMUNICATION IN A CONVERSATIONAL SETTING
No full textInternational audienc
Timing and Rhythmical Entrainment : Computational Sensorimotor Models for Human Robot Interpersonal Coordination
No full textInternational audienc
Impaired perception of an agent’s synchronizing behavior reduces positive attitude towards robots in schizophrenia patients
No full textInternational audienc
Eccentric cycling involves greater mental demand and cortical activation of the frontoparietal network
No full textInternational audienceEccentric, compared to concentric exercise, is proposed to involve different neuro‐motor processing strategies and a higher level of mental demand. This study compared eccentric and concentric cycling at matched perceived effort and torque for the mental demand and related‐cortical activation patterns. Nineteen men (30 ± 6 years) performed four different 5‐min cycling conditions at 30 RPM on a semi‐recumbent isokinetic cycle ergometer: (1) concentric at a moderate perceived effort (23 on the CR100® scale) without torque feedback; (2) concentric and (3) eccentric at the same average torque produced in the first condition; and (4) eccentric at the same moderate perceived effort than the first concentric condition. The conditions two to four were randomized. After each condition, mental demand was monitored using the NASA Task Load Index scale. Changes in oxy‐(O 2 Hb) and deoxy‐(HHb) hemoglobin during exercise were measured over both prefrontal cortices and the right parietal lobe from a 15‐probe layout using a continuous‐wave NIRS system. Mental demand was significantly higher during eccentric compared to concentric cycling (+52%, p = 0.012) and when the exercise intensity was fixed by the torque rather than the perceived effort (+70%, p < 0.001). For both torque‐ or perceived effort‐matched exercises, O 2 Hb increased significantly ( p < 0.001) in the left and right prefrontal cortices, and right parietal lobe, and HHb decreased in the left, and right, prefrontal cortices during eccentric compared to concentric cycling. This study supports that acute eccentric cycling, compared to concentric cycling, involves a higher mental demand, and frontoparietal network activation
International Handbook on the Assessment of Odour Exposure using Dispersion Modelling
No full textInternational audienceThis handbook presents different aspects needed for evaluating odour exposure by using dispersion modelling to help the final user. This handbook applies to calculating the odour/odorant level in ambient air from odour emission sources; choosing appropriate odour models depending on a project's specific conditions, in particular, dealing with complex situations; selecting appropriate meteorology. understanding the dose-response criteria and how the Frequency-Intensity-Duration-Offensiveness-Sensitivity scheme fits in a result; and the preparation of an odour report based on the results of a model.en