Heritability and Artificial Selection on Ambulatory Dispersal Distance in Tetranychus urticae: Effects of Density and Maternal Effects

Dispersal distance is understudied although the evolution of dispersal distance affects the distribution of genetic diversity through space. Using the two-spotted spider mite, Tetranychus urticae, we tested the conditions under which dispersal distance could evolve. To this aim, we performed artificial selection based on dispersal distance by choosing 40 individuals (out of 150) that settled furthest from the home patch (high dispersal, HDIS) and 40 individuals that remained close to the home patch (low dispersal, LDIS) with three replicates per treatment. We did not observe a response to selection nor a difference between treatments in life-history traits (fecundity, survival, longevity, and sex-ratio) after ten generations of selection. However, we show that heritability for dispersal distance depends on density. Heritability for dispersal distance was low and non-significant when using the same density as the artificial selection experiments while heritability becomes significant at a lower density. Furthermore, we show that maternal effects may have influenced the dispersal behaviour of the mites. Our results suggest primarily that selection did not work because high density and maternal effects induced phenotypic plasticity for dispersal distance. Density and maternal effects may affect the evolution of dispersal distance and should be incorporated into future theoretical and empirical studies

Determination of biomechanical markers characterizing early deterioration of locomotion in patients with Multiple Sclerosis

En dépit des plaintes des patients, la prise en charge rééducative de la Sclérose en Plaques (SEP) précoce se heurte à la difficulté d’objectiver les troubles locomoteurs par les tests cliniques. L’objectif général de ce travail de thèse était d’apporter une réponse à ce verrou clinique en utilisant les outils de la biomécanique. Dans ce but, cinq études ont été mises en place, avec les objectifs suivants : (i) de comparer les couples articulaires du membre inférieur d’appui lors de l’initiation de la marche chez les patients SEP au stade précoce (EDSS < 4) à des témoins en bonne santé, (ii) comparer le premier appui lors de la marche sur le plan spatio-temporel, cinématique et dynamique chez les patients SEP à des témoins en bonne santé, (iii) d’évaluer les accélérations au niveau de la tête et du tronc lors de la marche tandem chez des patients SEP au stade précoce et chez des témoins en bonne santé, (iv) de décrire la construction de 2 index basés sur la quantité de mouvements linéaires pour évaluer la contribution de chaque segment et leur perte d’efficience lors de la marche tandem, application à un patient SEP au stade précoce et à un témoin en bonne santé, (v) de comparer les paramètres spatio-temporels et les index de quantités de mouvements linéaires lors de la marche tandem chez les patients SEP au stade précoce à des témoins en bonne santé. La première étude montre que les patients SEP présentent des altérations significatives des couples articulaires à la cheville et au genou au membre inférieur d’appui lors de l’initiation de la marche en comparaison aux sujets en bonne santé. Les modulations des couples articulaires sont presque absentes durant la phase d’ajustements posturaux anticipateurs chez les patients SEP. Ces altérations montrent une modification du programme moteur de l’initiation de la marche avec la perte de modulation à la cheville et au genou d’appui. La deuxième étude portant sur le premier appui a permis de démontrer que les patients SEP présentent un premier et un deuxième pas significativement plus courts, tout en maintenant une augmentation progressive de la vitesse de marche en comparaison aux sujets en bonne santé. Ceci pourrait constituer une stratégie adaptative des patients SEP pour augmenter la stabilité lors de la période de transition et pourrait être en lien avec la présence de co-contractions musculaires à la cheville. La troisième étude a montré que les accélérations de la tête et du tronc permettaient de discriminer les patients SEP au stade précoce à des témoins en bonne santé. La quatrième et la cinquième étude ont permis de décrire la méthodologie de construction des index de contribution et d'inefficience. Leur application aux patients SEP en comparaison à des témoins en bonne santé, lors de la marche tandem, montre une augmentation significative des mouvements des membres supérieurs lors de la marche tandem en comparaison aux sujets sains. Ces index pourraient être utilisés pour le dépistage et le suivi des troubles de l’équilibre au stade précoce dans la SEP. Les résultats de ces études montrent que les couples articulaires lors de l'initiation de la marche et l'utilisation des index de contribution et d'inefficience pourraient être des marqueurs précoces de dépistage et de suivi de la progression du handicap locomoteur chez les patients SEP. Des programmes de rééducation spécifiques pourraient être développés pour diminuer l’impact des troubles locomoteurs chez les patients SEP au stade précoce.Despite patients complaints, the rehabilitation of people with Multiple Sclerosis (MS) at an early stage of the disease is challenging due to the difficulty of describing locomotor disorders through clinical tests. The general objective of this thesis work was to provide an answer to this clinical challenge by using the tools of biomechanics. Five studies were set up, with the following objectives: (i) to compare the net muscular moment at the stance limb during the gait initiation in patients with early MS (EDSS <4 ) to healthy controls, (ii) to compare the spatiotemporal, kinematic and kinetic parameters occurring at the first stance during walking in MS patients to healthy controls, (iii) to compare the head and trunk accelerations during tandem gait between early-stage MS patients and healthy controls, (iv) to describe the construction of 2 indexes based on the amount of linear moments to assess the contribution of each body segment and their loss of effectiveness to tandem gait, (v) to compare the spatio-temporal parameters and the 2 indexes calculated from linear moments during tandem gait in early-stage MS patients with healthy controls. The first study showed that MS patients had significant net muscular moment alterations at the stance ankle and knee joints during gait initiation compared to healthy people. MS patients’ net muscular moments were characterized by a near absence of modulation during the anticipatory postural adjustments phase. These alterations are the reflect of a modification of the gait initiation motor program. The second study, focusing on the first stances after gait initiation, demonstrated that MS patients had significantly shorter first and second steps, while maintaining a gradual increase of their walking speed compared to healthy subjects. This could constitute an adaptive strategy displayed by MS patients to increase their stability especially during the transition periods and could be related to co-contractions around the ankle. The third study showed that head and trunk accelerations allowed to discriminate early stage MS patients from healthy controls. The fourth and fifth studies described the methodology for constructing the contribution and inefficiency indexes from linear momentum. The application of these two indexes to MS patients in comparison to healthy controls, during tandem gait, showed a significant increase in upper limbs movements in the MS group. These indexes could be used for screening and monitoring early stage balance disorders in MS. The results of these studies showed that the net muscular moments of the stance limb during gait initiation and the use of contribution and inefficiency indexes could be used as early biomechanical markers for screening and monitoring the progression of locomotor disability in MS patients. Based on their use, specific rehabilitation programs could be developed to reduce the impact of locomotor disorders in early stage MS patients

Similitudes et différences entre l’évaluation d’impact sur la santé et l’évaluation de politiques publiques

National audienceIntroduction : L’évaluation d’impact sur la santé (EIS) se développe rapidement en France. Elle est proche d’autres démarches, telles que l’évaluation de politiques publiques (EPP) avec laquelle elle est parfois confondue.But de l’étude : Cet article a pour objectifs d’identifier les similitudes et différences entre EIS et EPP et d’apprécier dans quelle mesure les compétences en EPP sont transférables pour l’EIS.Résultats : Les deux démarches présentent des traits communs : elles sont basées sur des principes et valeurs structurant la pratique ; elles produisent un jugement au terme d’un processus d’argumentation ; elles suivent le même processus intellectuel et utilisent des outils similaires. Cependant, l’EIS présente des spécificités qui justifient le renforcement des compétences notamment en lien avec sa dimension participative.Conclusions : Les deux démarches présentent plus de similitudes que de différences en raison de leur nature évaluative. Les compétences acquises en EPP sont transférables à l’EIS et l’évaluateur à la croisée des deux exercices peut revisiter et enrichir sa pratique en EPP

Multi-Resolution Analysis for two-phase flows with heat and mass transfer

International audienceTwo-phase flows combined with heat and mass transfer may present configurations in which dilatable gas pockets coexist along with nearly-incompressible liquid. Finite Volume discretisation of such compressible equations are known to introduce excessive numerical diffusion and to severely restrain time steps. Adequate solver has been developed to tackle these issues (Chalons, 2016), especially in the presence of a sharp interface (Zou, 2020, 2022). To handle multi scales inherently arising in complex two-phase flows, adaptive meshing is an efficient strategy to reduce computation cost compared to uniform grids. In the present study, we use the Multi-Resolution Analysis (MRA) (Harten, 1994), based on local wavelet basis decomposition. This method provide a measure of local error to select regions to refine or derefine and garantees a precise control of the additionnal error introduced by mesh operations, independantly of conservation equations and problems. This approach was successfully applied to two-phase flows with sharp interface representation (Han, 2014) and we extend it to low-Mach flows. We focus on configurations with heat and mass transfer, to exhibit accuracy and advantages of the MRA method, with respect to other adaptive methods (mainly Adaptive Mesh Refinement (AMR) (Berger, 1989))

Multi-Resolution Analysis for two-phase flows with heat and mass transfer

International audienceTwo-phase flows combined with heat and mass transfer may present configurations in which dilatable gas pockets coexist along with nearly-incompressible liquid. Finite Volume discretisation of such compressible equations are known to introduce excessive numerical diffusion and to severely restrain time steps. Adequate solver has been developed to tackle these issues (Chalons, 2016), especially in the presence of a sharp interface (Zou, 2020, 2022). To handle multi scales inherently arising in complex two-phase flows, adaptive meshing is an efficient strategy to reduce computation cost compared to uniform grids. In the present study, we use the Multi-Resolution Analysis (MRA) (Harten, 1994), based on local wavelet basis decomposition. This method provide a measure of local error to select regions to refine or derefine and garantees a precise control of the additionnal error introduced by mesh operations, independantly of conservation equations and problems. This approach was successfully applied to two-phase flows with sharp interface representation (Han, 2014) and we extend it to low-Mach flows. We focus on configurations with heat and mass transfer, to exhibit accuracy and advantages of the MRA method, with respect to other adaptive methods (mainly Adaptive Mesh Refinement (AMR) (Berger, 1989))

Multi-Resolution Analysis for two-phase flows with heat and mass transfer

International audienceTwo-phase flows combined with heat and mass transfer may present configurations in which dilatable gas pockets coexist along with nearly-incompressible liquid. Finite Volume discretisation of such compressible equations are known to introduce excessive numerical diffusion and to severely restrain time steps. Adequate solver has been developed to tackle these issues (Chalons, 2016), especially in the presence of a sharp interface (Zou, 2020, 2022). To handle multi scales inherently arising in complex two-phase flows, adaptive meshing is an efficient strategy to reduce computation cost compared to uniform grids. In the present study, we use the Multi-Resolution Analysis (MRA) (Harten, 1994), based on local wavelet basis decomposition. This method provide a measure of local error to select regions to refine or derefine and garantees a precise control of the additionnal error introduced by mesh operations, independantly of conservation equations and problems. This approach was successfully applied to two-phase flows with sharp interface representation (Han, 2014) and we extend it to low-Mach flows. We focus on configurations with heat and mass transfer, to exhibit accuracy and advantages of the MRA method, with respect to other adaptive methods (mainly Adaptive Mesh Refinement (AMR) (Berger, 1989))

Stress Urinary Incontinence in Women With Multiple Sclerosis

Purpose To report the prevalence and risk factors of stress urinary incontinence (SUI) and the prevalence of intrinsic sphincter deficiency in women with multiple sclerosis (MS). Methods We conducted a retrospective study. Female patients with MS, followed for lower urinary tract symptoms (LUTS) during a 15-year period were included. Demographic data, MS history, expanded disability status scale (EDSS) score at the urodynamic visit, obstetrical past, birth weight, LUTS, and urodynamic findings were collected. SUI was defined as incontinence during cough, or any effort. A maximum urethral closure pressure less than 30 cm H2O defined intrinsic sphincter deficiency. Results We included 363 women with a mean age of 46.7±10.8 years and a mean disease duration of 12.9±8.7 years. The incidence of relapsing remitting MS, a secondary progressive form, and a primary progressive form was 60.6%, 32.8%, and 6.6%, respectively. The prevalence of SUI was 31.4%. The prevalence of intrinsic sphincter deficiency was 1.4% and 0.8% of these patients had a SUI (P=0.300). In a multivariate analysis, women with a SUI had significantly higher birth weight (P=0.030), a pelvic organ prolapse (P=0.021), urgent urinary incontinence (P=0.006), a lower EDSS score (P=0.019), and a weaker containing effort (P<0.001). Conclusions The prevalence of SUI in women with MS was 31.4%. This symptom could affect the quality of life of women with MS