Exergaming in a Multiplayer and Inter-Team Competition Mode with Play Lü: Effects on Adolescents’ Moderate-to-Vigorous Physical Activity and Situational Interest

Objective: The goal of this study was to evaluate the impact of a Play Lü inter-team competition exergame on adolescents’ moderate-to-vigorous physical activity (MVPA) and situational interest (SI). Materials and Methods: A total of 110 students (Mage = 13.7 ± 1.1, 12-16 years, 53.7 % girls, MBMI = 19.9 ± 3.2) from a secondary school located in Switzerland participated to the study. They played three separate 20-min games in a counterbalance allocated order: (1) Play Lü multiplayer and inter-team competition exergame; (2) Play Lü single-player competition exergame; and (3) Tic-Tac-Toe multiplayer and inter-team competition game. The participants’ MVPA was measured during each 20-min game using ActiGraph GT3X+ accelerometers and SI was measured immediately after each game. Results: Regarding Play Lü, the results showed higher MVPA and SI scores in the multiplayer and inter-team competition mode than in the single-player competition mode. Moreover, Play Lü elicited greater effects compared to the Tic-Tac-Toe game within a multiplayer and inter-team competition mode. Conclusion: The Play Lü inter-team competition exergame might be considered as a relevant strategy to improve adolescents’ motivation and physical activity, which can be applied in a physical education context

APOBEC3A Is a Specific Inhibitor of the Early Phases of HIV-1 Infection in Myeloid Cells

Myeloid cells play numerous roles in HIV-1 pathogenesis serving as a vehicle for viral spread and as a viral reservoir. Yet, cells of this lineage generally resist HIV-1 infection when compared to cells of other lineages, a phenomenon particularly acute during the early phases of infection. Here, we explore the role of APOBEC3A on these steps. APOBEC3A is a member of the APOBEC3 family that is highly expressed in myeloid cells, but so far lacks a known antiviral effect against retroviruses. Using ectopic expression of APOBEC3A in established cell lines and specific silencing in primary macrophages and dendritic cells, we demonstrate that the pool of APOBEC3A in target cells inhibits the early phases of HIV-1 infection and the spread of replication-competent R5-tropic HIV-1, specifically in cells of myeloid origins. In these cells, APOBEC3A affects the amount of vDNA synthesized over the course of infection. The susceptibility to the antiviral effect of APOBEC3A is conserved among primate lentiviruses, although the viral protein Vpx coded by members of the SIVSM/HIV-2 lineage provides partial protection from APOBEC3A during infection. Our results indicate that APOBEC3A is a previously unrecognized antiviral factor that targets primate lentiviruses specifically in myeloid cells and that acts during the early phases of infection directly in target cells. The findings presented here open up new venues on the role of APOBEC3A during HIV infection and pathogenesis, on the role of the cellular context in the regulation of the antiviral activities of members of the APOBEC3 family and more generally on the natural functions of APOBEC3A

Sequential decision making under ordinal uncertainty: A qualitative alternative to the Hurwicz criterion

International audienceThis paper focuses on sequential qualitative decision problems, where no probability distribution on the states that may follow an action is available. New qualitative criteria that are based on ordinal uninorms and namely R and R ⁎ are proposed. Like the Hurwicz criterion, the R and R⁎ uninorms arbitrate between pure pessimism and pure optimism, and generalize the Maximin and Maximax criteria. But contrarily to the Hurwicz criterion they are associative, purely ordinal and compatible with Dynamic Consistency and Consequentialism. These important properties allow the construction of an optimal strategy in polytime, following an algorithm of Dynamic Programming. Making a step further, we then generalize ⁎ to qualitative decision under possibilistic uncertainty, proposing an alternative to the classical optimistic and pessimistic criteria used for the computation of optimal strategies in possibilistic decision trees

Comportement dynamique au centrosome de la tyrosine kinase Syk, un nouveau suppresseur de tumeur dans le sein (Etude par microscopie à haute résolution)

Très étudié pour son rôle dans la signalisation des immuno-récepteurs, la tyrosine kinase Syk agirait comme suppresseur de tumeur et de métastase dans l'épithélium mammaire. Le mécanisme de cette activité anti-oncogénique reste inconnu. En plus de la localisation cytoplasmique, Syk est localisée aux extensions membranaires et au centrosome où elle est catalytiquement active, avec une variation de la concentration au cours du cycle cellulaire. Les localisations de mutants de Syk dans la cellule dépendent du type du site tyrosine muté d'une part, et les effecteurs potentiels de Syk reconnus par analyse protéomique d'autre part, font penser à un code de phosphorylation qui dépendrait du résidu tyrosine activé pour cibler la kinase à des sites sub-cellulaires différents. Afin de caractériser la dynamique des échanges de Syk entre compartiments subcellulaires et surtout dans le centrosome, nous avons employé des approches d'imagerie à haute résolution sur cellules vivantes de cancer du sein transfectées par des formes sauvage ou mutantes de DsRed-Syk. L'approche de FRAP et l'utilisation d'une chimère photo-activable (PA-GFP-Syk) montrent que Syk est recrutée activement au centrosome, avec un de 18,54 +- 3,63 sec. L'utilisation d'inhibiteurs de polymérisation de microtubules ou du moteur moléculaire dynéine/dynactine, la visualisation par TIRF des déplacements de particules de Syk à la base des cellules, la co-localisation par immunofluorescence, l'observation confirmée par modélisation d'une dérive directionnelle de PA-GFP-Syk après activation, tout indique que cytosquelette microtubulaire et moteur moléculaire sont nécessaires pour le recrutement de Syk au centrosome.Initially studied for its role in immunoreceptor-mediated downstream signalling, the tyrosine kinase Syk acts like a tumor and metastasis suppressor within breast cancer cells. The mechanism of its anti-oncogenic activity remains, however, to be identified. In addition to its cytoplasmic localization, Syk is also visualized at plasma membrane extensions and at the centrosome in which it exhibits a catalytic activity and is tightly regulated along the cell cycle. Considering both the action sites of potential effectors as identified by proteomic approach and differently targeted DsRed-Syk following the tyrosine residue mutated, we hypothesize a phosphorylation code targeting the kinase at different sub-cellular compartments depending on the tyrosine residue activated. In order to determine whether a dynamic exchange occurs between the subcellular compartments, we applied different imaging techniques on living breast cancer cells transiently expressing wild-type and mutant fluorescent Syk chimeras. Fluorescence Recovery After Photobleaching (FRAP) with DsRed-Syk and photoactivatable GFP-Syk clearly evidenced rapid exchanges at the centrosomes with a recruitment of 18,54 +- 3,63 sec. Treatments affecting the microtubule skeleton or the molecular motor dynein, TIRF imaging of Syk clusters, antibody co-localization, directional drift of activated PA-GFP-Syk corroborated by mathematical modelling, together show that the tubulin cytoskeleton and the microtubule motor dynein/dynactin are necessary for Syk recruitment at the centrosome.MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Sequential Decision-Making Under Uncertainty Using Hybrid Probability-Possibility Functions

International audienceProbabilistic and possibilistic models of sequential decision problems are known to possess good behavioral and algorithmic properties. In this paper, the range of models of problems of sequential decision under uncertainty that are dynamically consistent, consequentialist and allow for tree reduction is enlarged by considering a representation of uncertainty that is both probabilistic and possibilistic. The corresponding utility functional is expected utility for highly likely states, and an optimistic or pessimistic possibility-based criterion for unlikely states

Photobleaching as a tool to measure the local strain field in fibrous membranes of connective tissues

Connective tissues are complex structures which contain collagen and elastin fibers. These fiber based structures have a great influence on material mechanical properties and need to be studied at the microscopic scale. Several microscopy techniques have been developed in order to image such microstructures; among them are two-photon excited fluorescence microscopy and second harmonic generation. These observations have been coupled with mechanical characterization to link microstructure kinematic to macroscopic material parameter evolution. In this study, we present a new approach to measure lo cal strain in soft biological tissues using a side effect of fluorescence microscopy: photobleaching. Controlling the loss of fluorescence induced by photobleaching, we create a pattern on our sample that we can monitor during mechanical loading. The image analysis allows computing 3D displacements of the patterns at various loading levels. Then, local strain distribution is derived using the finite element discretization on a four nodes element mesh created from our photobleached pattern. Photobleaching tests on human liver's capsule have revealed that this technique is non-destructive and has not any impact on mechanical properties. This method is likely to have other applications in biological material studies, considering that all collagen-elastin fibers based biological tissues possess autofluorescence properties, and thus can be photobleached

Exergaming in a Multiplayer and Inter-Team Competition Mode with Play Lü

International audienceObjective: The goal of this study was to evaluate the impact of a Play Lü inter-team competition exergame on adolescents’ moderate-to-vigorous physical activity (MVPA) and situational interest (SI). Materials and Methods: A total of 110 students ( M age = 13.7 ± 1.1, 12-16 years, 53.7 % girls, M BMI = 19.9 ± 3.2) from a secondary school located in Switzerland participated to the study. They played three separate 20-min games in a counterbalance allocated order: (1) Play Lü multiplayer and inter-team competition exergame; (2) Play Lü single-player competition exergame; and (3) Tic-Tac-Toe multiplayer and inter-team competition game. The participants’ MVPA was measured during each 20-min game using ActiGraph GT3X+ accelerometers and SI was measured immediately after each game. Results: Regarding Play Lü, the results showed higher MVPA and SI scores in the multiplayer and inter-team competition mode than in the single-player competition mode. Moreover, Play Lü elicited greater effects compared to the Tic-Tac-Toe game within a multiplayer and inter-team competition mode. Conclusion: The Play Lü inter-team competition exergame might be considered as a relevant strategy to improve adolescents’ motivation and physical activity, which can be applied in a physical education context

Mesure de l’eau du sol : questions, méthodes et outils Exemples d’application sur deux plateformes champs du réseau « PHENOME »

La mesure de la quantité d’eau dans le sol et de sa disponibilité pour les plantes sont deux éléments clé pour permettre l’interprétation des données phénotypiques collectées sur les expérimentations conduites en plein champ. Pour réaliser ces mesures, l’expérimentateur doit prendre en compte la variabilité du sol avec les connaissances sur le site expérimental dont il dispose. Il est également confronté à la question délicate et assez peu renseignée du choix des outils pour mesurer et suivre la variation de l’eau dans le sol au sein de l’expérimentation. Cet article a pour objectif de fournir aux expérimentateurs les éléments théoriques qui vont lui permettre de définir précisément les questions à se poser lorsqu’ils veulent mesurer « l’eau du sol ». Il présente également les grandes familles de capteurs disponibles sur le marché avec leurs avantages et leurs inconvénients. Ces éléments théoriques sont illustrés par des exemples concrets issus des pratiques sur les plateformes de phénotypage au champ du réseau PHENOME : depuis la connaissance de la variabilité des sols, jusqu’à la consultation en temps réel et l’archivage des données des capteurs, avec un focus particulier sur l’installation et la mise en oeuvre opérationnelle des sondes capacitives (enviroscan)

Centrosomal targeting of Syk kinase is controlled by its catalytic activity and depends on microtubules and the dynein motor.: Active recruitment of Syk to the centrosomes

Fargier, Guillaume Favard, Cyril Parmeggiani, Andrea Sahuquet, Alain Merezegue, Fabrice Morel, Anne Denis, Marie Molinari, Nicolas Mangeat, Paul H. Coopman, Peter J. Montcourrier, PhilippeInternational audienceThe nonreceptor Syk kinase is detected in epithelial cells, where it acts as a tumor suppressor, in addition to its well-established role in immunoreceptor-based signal transduction in hematopoietic cells. Thus, several carcinomas and melanomas have subnormal concentrations of Syk. Although Syk is mainly localized at the plasma membrane, it is also present in centrosomes, where it is involved in the control of cell division. The mechanisms responsible for its centrosomal localization and action are unknown. We used wild-type and mutant fluorescent Syk fusion proteins in live-cell imaging (fluorescence recovery after photobleaching, total internal reflection fluorescence, and photoactivation) combined with mathematical modeling to demonstrate that Syk is actively transported to the centrosomes via the microtubules and that this transport depends on the dynein/dynactin molecular motor. Syk can only target the centrosomes if its kinase activity is intact and it is catalytically active at the centrosomes. We showed that the autophosphorylated Y130 Syk residue helps to uncouple Syk from the plasma membrane and to promote its translocation to the centrosome, suggesting that the subcellular location of Syk depends on its autophosphorylation on specific tyrosine residues. We have thus established the details of how Syk is trafficked intracellularly and found evidence that its targeting to the centrosomes is controlled by autophosphorylation