253 research outputs found
Les possibles corporels : support biologique, determinations sociales
LâĂ©tude des coureurs Ă pied de compĂ©tition sâavĂšre particuliĂšrement propice pour analyser les liens entre le social et le biologique, en ce quâelle conduit Ă rĂ©flĂ©chir Ă ce qui dĂ©termine les capacitĂ©s corporelles dâun individu. Dans cette optique, trois pistes sont explorĂ©es : la premiĂšre sâintĂ©resse Ă la maniĂšre par laquelle le social dĂ©termine les corps dans leur matĂ©rialitĂ© mĂȘme ; la deuxiĂšme met lâaccent sur le façonnement social des catĂ©gories de perception et montre que la fatigue ressentie par un athlĂšte sâinscrit Ă lâinterface entre des manifestations physiologiques et un encodage symbolique de ces derniĂšres ; la troisiĂšme fait ressortir que, loin dâĂȘtre rĂ©ductibles Ă la mise en jeu de capacitĂ©s physiques « pures », la performance procĂšde dâune interaction qui dĂ©termine ce dont un coureur est capable. ConsidĂ©rĂ©s dans leur ensemble, ces trois dĂ©veloppements visent Ă rendre compte de ce que le social fait Ă des potentialitĂ©s physiologiques dont il nây a pas lieu de penser quâelles puissent ĂȘtre, Ă elles seules, au principe de diffĂ©rences interindividuelles en matiĂšre de possibles corporels.The study of competitive runners proves particularly rich for analyzing connections between the social and the biological, as it leads us to consider what determines an individualâs physical capacities. Accordingly, this article explores this question from three angles : the first looks at how the social determines the very materiality of the body ; the second emphasizes how categories of perception are socially shaped, and shows that the fatigue athletes feel is situated at the interface of physiological manifestation and its symbolic coding ; the third reveals that performance, far from boiling down to the expression of âpureâ physical capacities, arises instead from an interaction that determines what a runner can accomplish. Taken together, these three aspects illustrate the influence of social facts on physiological potential, which leaves no reason to think that it could be the sole basis of inter-individual differences in what the body may achieve
Effect of coupling with internal and external fluids on the mechanical behavior of aerostats
International audienceIn the context of the simulation of aerostats in flight, we are interested here in the coupling between a deformable structure, the fluid contained inside and the fluid flow outside. To study the dynamic stability of such systems, the fluid-structure coupled equations are linearized around an equilibrium position and, by assuming that the fluid flow perturbations are potential, the loads exerted by the fluids on the moving structure can be decomposed in terms proportional, respectively, to the displacement, velocity and acceleration fields of the structure, representing what are generally called the added stiffness, damping and mass effects of the fluid on the structure. In this work, a focus is made on the added mass because, for such lightweight structures, its effect is of prime importance. A Boundary Element Method (BEM) is proposed to compute the fluid added mass operators, for external and internal fluids, and for any structure deformation field. Numerical and experimental validations are conducted on an axisymmetric ellipsoid mockup immerged in water and subject to rigid motions. Variations of the imposed movement amplitude and velocity have also helped to evaluate the validity domain of this model
Le contractuel, lâentrepreneur, lâassistĂ© : trois figures du travailleur sportif
National audienc
Digital rebirth of the greatest church of Cluny Maior Ecclesia: From optronic surveys to real time use of the digital Model
Our multidisciplinary team has virtually reconstructed the greatest church of the Romanesque period in Europe. The third church of the Abbey of Cluny (12th c.) has been destroyed after the French Revolution, leaving only 8% of the building standing. Many documents have been studied, to include the latest archaeological knowledge in the virtual model. Most remains have been scanned for CAD restitution. The mock-up of the church needed 1600 different numerical files, including the scanned pieces and the anastylosis of a Romanesque portal, a Gothic façade and a mosaic pavement. We faced various difficulties to assemble the different elements of the huge building, and to include the digitized parts. Our workflow consisted in generating geometrical shapes of the church, enriched with metadata such as texture, material... The whole mock up was finally exported to dedicated software to run the rendering step. Our work consisted in creating a whole database of 3D models as well as 2D sources (plans, engravings, pictures...) accessible by the scientific community. The scientific perspectives focus on a representation in virtual immersion of the grand church at scale 1 and an access to the digital mock-up through Augmented Reality.Gunzo projec
La reconstitution 3D du chevet de Cluny III : clĂŽture de chĆur, stalles, pavement, peintures murales et vitraux
Le chevet de Cluny Ă©tait la partie la plus richement dĂ©corĂ©e par la prĂ©sence de sculptures, de peintures, de vitraux, de pavements en marbre et dâobjets liturgiques prĂ©cieux. Une partie de ces Ă©lĂ©ments nous est parvenue grĂące aux fouilles archĂ©ologiques et a permis de proposer des hypothĂšses de restitution. Le parti gĂ©nĂ©ral Ă©tait celui de reprĂ©senter lâĂ©glise dans son Ă©tat Ă la fin du xve siĂšcle, sans tenir compte des reprises plus tardives. Nous avons tentĂ© de rĂ©unir les connaissances actuelles sur chacun des Ă©lĂ©ments pour proposer une restitution en 3D du chĆur 2, de maniĂšre Ă le prĂ©senter sur un Ă©cran et dans un film, au cours de la visite sur le site. Il en rĂ©sulte des images, qui seront amenĂ©es Ă Ă©voluer au fur et Ă mesure des nouvelles dĂ©couvertes dans les prochaines annĂ©es
La reconstitution 3D du chevet de Cluny III : clĂŽture de chĆur, stalles, pavement, peintures murales et vitraux
Le chevet de Cluny Ă©tait la partie la plus richement dĂ©corĂ©e par la prĂ©sence de sculptures, de peintures, de vitraux, de pavements en marbre et dâobjets liturgiques prĂ©cieux. Une partie de ces Ă©lĂ©ments nous est parvenue grĂące aux fouilles archĂ©ologiques et a permis de proposer des hypothĂšses de restitution. Le parti gĂ©nĂ©ral Ă©tait celui de reprĂ©senter lâĂ©glise dans son Ă©tat Ă la fin du xve siĂšcle, sans tenir compte des reprises plus tardives. Nous avons tentĂ© de rĂ©unir les connaissances actuelles sur chacun des Ă©lĂ©ments pour proposer une restitution en 3D du chĆur 2, de maniĂšre Ă le prĂ©senter sur un Ă©cran et dans un film, au cours de la visite sur le site. Il en rĂ©sulte des images, qui seront amenĂ©es Ă Ă©voluer au fur et Ă mesure des nouvelles dĂ©couvertes dans les prochaines annĂ©es
Numerical study of the vibrations of an elastic container filled with an inviscid fluid
International audienceWe investigate numerically the vibrational behavior of a simple finite element model that stands for an elastic container filled with an inviscid fluid. The underlying mathematical model is detailed and its spectra is characterized. The finite element method relies upon the added-mass formulation of Morand and Ohayon. A parametric study allows to characterize the system's response to dimensionless parameters in terms of eigenfrequencies. Then an insight into the mode shapes is provided, with a discussion on the presence and the behavior of singular modes caused by specific boundary conditions in the fluid
La reconstitution 3D du chevet de Cluny IIIÂ : clĂŽture de chĆur, stalles, pavement, peintures murales et vitraux
Le chevet de Cluny Ă©tait la partie la plus richement dĂ©corĂ©e par la prĂ©sence de sculptures, de peintures, de vitraux, de pavements en marbre et dâobjets liturgiques prĂ©cieux. Une partie de ces Ă©lĂ©ments nous est parvenue grĂące aux fouilles archĂ©ologiques et a permis de proposer des hypothĂšses de restitution. Le parti gĂ©nĂ©ral Ă©tait celui de reprĂ©senter lâĂ©glise dans son Ă©tat Ă la fin du xve siĂšcle, sans tenir compte des reprises plus tardives. Nous avons tentĂ© de rĂ©unir les connaissances actuel..
Beryllium Nitrate Inhibits Fibroblast Migration to Disrupt Epimorphic Regeneration
Epimorphic regeneration proceeds with or without formation of a blastema, as observed for the limb and skin, respectively. Inhibition of epimorphic regeneration provides a means to interrogate the cellular and molecular mechanisms that regulate it. In this study, we show that exposing amputated limbs to beryllium nitrate disrupts blastema formation and causes severe patterning defects in limb regeneration. In contrast, exposing full-thickness skin wounds to beryllium only causes a delay in skin regeneration. By transplanting full-thickness skin from ubiquitous GFP-expressing axolotls to wild-type hosts, we demonstrate that beryllium inhibits fibroblast migration during limb and skin regeneration in vivo. Moreover, we show that beryllium also inhibits cell migration in vitro using axolotl and human fibroblasts. Interestingly, beryllium did not act as an immunostimulatory agent as it does in Anurans and mammals, nor did it affect keratinocyte migration, proliferation or re-epithelialization, suggesting that the effect of beryllium is cell type-specific. While we did not detect an increase in cell death during regeneration in response to beryllium, it did disrupt cell proliferation in mesenchymal cells. Taken together, our data show that normal blastema organogenesis cannot occur without timely infiltration of local fibroblasts and highlights the importance of positional information to instruct pattern formation during regeneration. In contrast, non-blastemal-based skin regeneration can occur despite early inhibition of fibroblast migration and cell proliferation
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