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Modélisation musculo-squelettique du tronc et des membres supérieurs : application à l’escrime-fauteuil
No full textThe prevention of musculoskeletal disorders, particularly in the upper limbs, is a crucial health issue for workers, but also for people with disabilities and the elderly. Prevention requires an understanding of the causes. These are multiple and sometimes complex, but the mechanical load at the joints remains one of the first elements to be determined. To this end, musculoskeletal models capable of taking into account the kinematic, dynamic and muscular complexity of the parts concerned (upper limbs and trunk in the context of this work) have been developed and are being continuously improved. From a kinematics point of view, the work developed in this thesis therefore aims to :i) Aggregate the existing models into a single model under a single numerical environmentii) Propose customisation parameters and the associated protocol to determine themiii) Evaluate the personalised models according to their different components, i.e. geometric and kinematic parts.Finally, an application for the prevention of musculoskeletal disorders in para-sportsmen practising para-fencing will be carried out through the study of the dynamic phases of attaque.La prévention des troubles musculosquelettiques, notamment au niveau des membres supérieurs, est un enjeu crucial de santé pour les travailleurs, mais également pour les personnes en situation de handicap, ou encore les personnes âgées. Prévenir nécessite de comprendre les causes. Or celles-ci sont multiples et parfois complexes mais le chargement mécanique supporté par l’articulation reste un des premiers éléments à déterminer. Pour ce faire, des modèles musculosquelettiques capables de prendre en compte la complexité cinématique, dynamique et musculaire des parties concernées (membres supérieurs et tronc dans le cadre de ce travail) ont été développés et sont en continuelle amélioration. En abordant un point de vue cinématique, les travaux développés dans cette thèse s'attachent donc à :i) Agréger les modèles existants dans un même modèle sous un seul environnement numérique) Proposer des paramètres de personnalisation et le protocole associé pour les déterminer) Évaluer les modèles personnalisés suivant les différentes composantes de ceux-ci, i.e. parties géométrique et cinématique. Enfin, une application à visée de prévention des troubles musculosquelettiques chez les para-sportifs pratiquant l’escrime fauteuil sera réalisée à travers l’étude cinématique de l’attaque en coup droit
Dealing with differential misclassification of an outcome or a covariate in association studies with an internally validated sample selected not at random
No full textInternational audienceBackground: To present an analytical framework for correcting misclassification when an imperfect test is used as an indicator of a disease in association studies, taking into account that part of the sample has joint test and disease data.Methods: We explored two scenarios, depending on whether the disease is a covariate or the outcome. The analysis sample includes an internal validation sample where the disease status is known in addition to the test. Joint likelihood models taking into account classification errors and the possible selection of the validation sample not at random were used. Simulations were performed to evaluate the methods. We illustrated our framework using data from a multi-cohort COVID-19 serological study conducted in France between 2020 and 2021, with serology as the imperfect test and SARS-CoV-2 infection as the disease. The dataset included concomitant measurements of the serological test and the SARS-CoV-2 infection status determined using additional virologic methods (PCR, neutralization assay) in 7% participants. We estimated 1) the association between incident persistent symptoms defined as a symptom lasting at least 8 weeks (outcome) and infection (covariate) and 2) the association between infection (outcome) and several covariates. For comparison, we also estimated 'naïve' models using serology without correction or using the internal validation sample only, as well as models under different assumptions about the missingness pattern of the SARS-CoV-2 infection status.Results: Simulations confirmed the methods' abilities to correct for misclassification and not at random selection of the validation sample. In the application, the estimated sensitivities and specificities of the serological test with respect to SARS-CoV-2 infection were 86.2%-87.7% and 95.8%-97.5%, respectively. Considering SARS-CoV-2 infection as a covariate, the corrected analysis identified a significant association between infection and persistent symptoms. Considering SARS-CoV-2 infection as the outcome, the corrected analysis identified an association between infection and age, gender and active smoking, but did not retrieve an association with living with at least one child at home and previous smoking, which were identified in the naïve analysis.Conclusion: This methodological framework can be applied in association studies when an imperfect test is used as an indicator of a disease and the disease status has been validated in a subset of the sample. We extended previous works to deal with not at random selection of this validated sample
In-depth analysis of predominant Mycobacterium tuberculosis L.2.2.M3strain from Panama, using TB-Annotator
No full textInternational audienceMycobacterium tuberculosis lineage 2 (L2) is often associated with increased drugresistance and rapid transmission. Panama recently reported an endemictransmission of drug-susceptible M. tuberculosis sublineage L2.2.M3 in Colon. Figure 4. Panama collection within a global context of Mycobacterium tuberculosis sublineage L2.2.M3. Panel A corresponds to preliminary results with an independent pipeline, and panels B to D to TB Annotator with the corresponding branch highlighted in pink. A) Global Mycobacterium maximum likelihood tree with 1,476 L2.2.M3 strains. Four groups were identified: Cluster A with 94 strains; Closest Relatives 1 (CR1) with 27 strains; Closest Relatives 2 (CR2) with 66 strains; and Closest Relatives 2 (CR3) with 13 strains. B) Cluster A branch composed of 94 isolates with unique SNP 518748 G>A. Isolates come from Panama (91), the Netherlands (1), Portugal (1), and the United States of America (1). C) CR1 composed of 27 isolates from Australia (1), Canada (3), China (2), Madagascar (1), Myanmar (4), Thailand (5), Viet Nam ( 8), and origin unknown (3). D) Closest Relatives 2 (CR2) composed of 66 isolates from Australia (8), Cambodia (1), Canada (5), China (3), Guatemala (3), India (1), Myanmar (1), Thailand(1), USA (1), Viet Nam (18), and origin unknown (19). Note: The closest relatives 3 (CR3) is the most distant common ancestor that could be traced. These isolates are from Canada (1), China (10), the USA (1), and Viet Nam (1). TB-Annotator results show that the Panama Cluster A forms a clonal complex within a larger tree of 1,568 genomes of L2.2.M3. Although the Colon sample set does not have enough markers to define it as a sublineage within L2.2.M3, our results suggest that the isolates document a new branch (internal distance of 35 +/- 17 SNP) that is very endemic in Panama with limited transmission to other countries. A plausible explanation could be that little time has passed (8 years) since the study population was formed
Poromechanical Modelling of the Time‐Dependent Response of In Vivo Human Skin During Extension
No full textInternational audienceABSTRACT This paper proposes a proof of concept application of a biphasic constitutive model to identify the mechanical properties of in vivo human skin under extension. Although poromechanics theory has been extensively used to model other soft biological tissues, only a few studies have been published for skin, and most have been limited to ex vivo or in silico conditions. However, in vivo procedures are crucial to determine the subject‐specific properties at different body sites. This study focuses on cyclic uni‐axial extension of the upper arm skin, using unpublished data collected by Chambert et al. Our analysis shows that a two‐layer finite element model allows representing all relevant features of the observed mechanical response to the imposed external loading, which was composed, in this contribution, of four loading‐sustaining‐unloading cycles. The Root Mean Square Error (RMSE) between the calibrated model and the measured Force‐time response was N. Our biphasic model represents a preliminary step towards investigating the mechanical conditions responsible for the onset of injury. It allows for the analysis of changes in Interstitial Fluid (IF) pressure, flow, and osmotic pressure, in addition to the mechanical fields. Future work will focus on the interaction of multiple biochemical factors and the complex network of regulatory signals
Annotating Audiovisual Corpora in the Humanities
No full textInternational audienceAs part of the OASIS project, and in collaboration with the DARIAH Working Group “Visual Media and Interactivity” (https://www.dariah.eu/activities/working-groups/visual-media-and-interactivity/), the Canevas Consortium is organising a workshop during the pre-conference day of the 5th DARIAH-HR International Conference, which will take place on Wednesday 22 October 2025. This workshop will be divided into two 3-hour sessions. The first will take place on Wednesday morning and aims to introduce participants to the PeerTube technology, developed by the French education-oriented video network Framasoft to offer an alternative to the services provided by the GAFAM, and particularly the online video hosting platform Youtube, and thus promote digital empowerment
Innovative methodological and analytical developments in the study of plant-soil fauna interactions
No full textInternational audiencePlant-soil interactions are modified by both biotic and abiotic factors, and understanding thesedynamics is essential to predict ecosystem responses to climate change. Root exudates play a centralrole in rhizosphere dynamics through the release of primary and specialized metabolites, which areinvolved in defense mechanisms, competition, and symbiosis. However, the influence of soil fauna onroot exudation remains poorly understood. To date, studying root exudation in soil matrices has beentechnically challenging, and the most commonly used systems hydroponic or hybrid fail to reproducerealistic interactions with soil fauna. Previously, in Poa annua, we employed the EcoRoots system –rhizoboxes with nitrocellulose traps at the root apex – to collect exudates in situ for GC-HRMS profiling.We showed that living soil fauna restructured exudate profiles, with earthworms exerting the strongesteffect, underscoring the need for soil-realistic sampling [1-2].Presently, we use a pot-based soil-hydroponic hybrid system in which plants remain in soil while asubset of roots is externally bathed in solution for exudate collection. We test how the springtailProtaphorura fimata modulates the quantity and composition of Arabidopsis thaliana exudatesbetween the wild-type Col-0 ecotype and the GSL-deficient gk0 mutant.We hypothesize that P. fimata reprograms root-shoot signaling to increase export of defensivespecialized metabolites, especially glucosinolates (GLS). Accordingly, a GLS-deficient gk0 mutant shoulddisplay compensatory salicylic-acid/jasmonic-acid (SA/JA) signatures and stronger root morphologicalperturbations.Our multiblock metabolomic approach couples hybrid in-soil sampling with complementary analyticaltechniques: (i) polymeric sorbent beads (Amberlite XAD7HP) to enrich GLS and other semipolars forLC-/HRMS; (ii) aqueous fractions for primary metabolites (e.g., sugars) by GC-HRMS after derivatization;and (iii) volatiles captured on sorptive tubes (Sorbstar®) and analyzed by thermal-desorption GC-HRMS.Preliminary collection tests confirm selective GLS enrichment and complementary coverage of aqueoussugars and volatiles.This methodology will provide a robust multiblock approach for the investigation of root exudation inother plant species with allelopathic potential or agronomic relevance
Levosimendan to Facilitate Weaning From ECMO in Patients With Severe Cardiogenic Shock
No full textInternational audienceImportance: Levosimendan may facilitate weaning from venoarterial extracorporeal membrane oxygenation (VA-ECMO) and improve survival, but supporting evidence remains limited.Objective: To assess whether early administration of levosimendan reduces the time to successful VA-ECMO weaning in patients with severe but potentially reversible cardiogenic shock.Design, setting, and participants: Randomized, double-blind, placebo-controlled trial conducted across 11 intensive care units (ICUs) in France. Between August 27, 2021, and September 10, 2024, 205 adult patients with acute cardiogenic shock who had started VA-ECMO in the preceding 48 hours were enrolled. Final follow-up was completed on November 10, 2024.Interventions: Patients were randomized in a 1:1 ratio to receive levosimendan, 0.15 μg/kg per minute, to be increased to 0.20 μg/kg per minute after 2 hours (n = 101), or placebo (n = 104).Main outcomes and measures: The primary outcome was time to successful ECMO weaning within 30 days following randomization. Secondary outcomes included ECMO-, mechanical ventilation-, and organ failure-free days, ICU and hospital lengths of stay, serious adverse events, and all-cause 30- and 60-day mortality.Results: Among the 205 randomized patients (median age, 58 [IQR, 50-67] years; 149 [72.7%] male), main cardiogenic shock etiologies were postcardiotomy (79 [38.5%]), acute myocardial infarction (56 [27.3%]), and myocarditis (28 [13.7%]). Treatment dose was increased to 0.20 ± 0.01 μg/kg per minute in 93% of patients receiving levosimendan and in 96% of those receiving placebo. Within 30 days, 69 of 101 patients (68.3%) had a successful ECMO weaning in the levosimendan group compared with 71 of 104 (68.3%) in the placebo group (risk difference, 0.0% [95% CI, -12.8% to 12.7%]; subdistribution hazard ratio, 1.02 [95% CI, 0.74-1.39]; P = .92). In the levosimendan and placebo groups, respectively, median ECMO duration (5 [IQR, 4-7] days vs 6 [IQR, 4-11] days; P = .53), mean ICU length of stay (18 [SD, 15] days vs 19 [SD, 15] days; P = .42), and 60-day mortality (27.7% vs 25.0%; risk difference, 2.7% [95% CI, -9.0% to 15.3%]; P = .78) did not differ significantly. Ventricular arrhythmias occurred more frequently with levosimendan (18 [17.8%] vs 9 [8.7%]; absolute risk difference, 9.2% [95% CI, 0.4%-18.1%]).Conclusions and relevance: Among patients with severe but potentially reversible cardiogenic shock supported by VA-ECMO, early levosimendan administration did not significantly reduce the time to successful weaning of ECMO compared with placebo.Trial registration: ClinicalTrials.gov Identifier: NCT04728932
Transpulmonary LOX-1 Levels Are Predictive of Acute Respiratory Distress Syndrome After Cardiac Surgery: A Proof-of-Concept Study
No full textInternational audienceBackground/Objectives: Acute respiratory distress syndrome (ARDS) is a life-threatening condition that frequently complicates high-risk cardiac surgery. We evaluated the circulating levels and transpulmonary gradient of intracellular proteins in patients at risk of developing ARDS after cardiac surgery using large scale-proteomics. Methods: We enrolled sixteen patients undergoing high-risk cardiac surgery, followed by planned ICU admission. Circulating levels of intracellular proteins were measured at the onset of the surgical procedure, at ICU admission (H0), and 24 h (H24) after surgery in blood samples simultaneously drawn from both the pulmonary artery and the left atrium. The primary endpoint was the occurrence of ARDS between ICU admission and the subsequent 48 h. Results: Among the studied proteins, the levels of intracellular lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) were higher at H24 in the pulmonary artery in patients who developed ARDS (6.96; 95% CI [6.83–7.23]) compared to patients who did not (6.48; 95% CI [6.27–6.66]), p-value = 0.016. The transpulmonary gradient of intracellular LOX-1 levels was not significantly different between ARDS and non-ARDS patients at H0 but it was more negative at H24 in ARDS (−0.23; 95% CI [−0.27, −0.14]) than in non-ARDS patients (0.03; 95% CI [−0.14, 0.32]; p-value= 0.031), with a hazard ratio HR = 0.39 (95% CI [0.18–0.86]); p-value= 0.035. The area under the ROC curve of H24 LOX-1 transpulmonary gradient to predict ARDS occurrence was 0.83 (95% CI [0.62–1.00]). Conclusions: The transpulmonary gradient of intracellular LOX-1 levels was negatively associated with the occurrence of ARDS within the first 48 h after high-risk cardiac surgery, suggesting that lung trapping of LOX-1 may be linked to postoperative ARDS
Pathophysiology and clinical use of agents with vasodilator properties in acute heart failure. A scientific statement of the Heart Failure Association ( HFA ) of the European Society of Cardiology ( ESC )
No full textInternational audienceAcute heart failure (AHF) affects millions of people each year and vasodilators have been a central part of treatment for over 25 years. The haemodynamic effects of vasodilators vary considerably among individual agents. Some vasodilators, such as nitrates, primarily act on the venous system by redistributing the circulating blood volume away from the heart towards the venous capacitance system. Other vasodilators, such as nesiritide, lead to balanced vasodilatation in the arteries and veins, decreasing left ventricular afterload and preload. Considering mechanisms of action, intravenous vasodilators are thought to be effective in patients with AHF, particularly in those with acute pulmonary oedema, where increased cardiac filling pressures and elevated systemic blood pressures occur in the absence of, or with minimal systemic fluid accumulation. However, the 2021 European heart failure guidelines have downgraded the use of vasodilators due to two recent studies and several contemporary meta‐analyses failing to show benefit in terms of survival. Thus, there remains no firm recommendation suggesting the use of vasodilator treatment over usual care. In addition, despite repeated efforts to develop new vasodilatory agents, no novel therapy has outperformed traditional AHF management. In parallel with the development of novel vasodilators, changing the design of clinical trials for AHF to consider phenotype diversity of AHF patients remains an unmet need. New randomized clinical trials should particularly focus on subgroups that may mechanistically derive benefit from vasodilators, which may entail moving enrolment of patients to clinical settings close to moment of decompensation, such as the emergency department
Sustainability science : participatory research (volume 4)
No full textThis fourth volume, devoted to sustainability science, continues to further the collective thinking on interdisciplinarity and the development of locallyintegrated research activities in the Global South. In this book, focusing on participatory research and presenting an overview of the current situationalong with feedback, IRD shares this bountiful research with the entire scientific community, while addressing the epistemological, ethical, value-oriented and institutional issues that it raises