34 research outputs found
Emergence of humanoid walking behaviors from mixed-integer model predictive control
No full textInternational audienceBalance strategies range from continuous postural adjustments to discrete changes in contacts: their simultaneous execution is required to maintain postural stability while considering the engaged walking activity. In order to compute optimal time, duration and position of footsteps along with the center of mass trajectory of a humanoid, a novel mixed-integer model of the system is presented. The introduction of this model in a predictive control problem brings the definition of a Mixed-Integer Quadratic Program, subject to linear constraints. Sim-ulation results demonstrate the simultaneous adaptation of the gait pattern and posture of the humanoid, in a walking activity under large disturbances, to efficiently compromise between task performance and balance. In addition, a push recovery scenario displays how, using a single balance-performance ratio, distinct behaviors of the humanoid can be specified
A V0-ATPase-dependent apical trafficking pathway maintains the polarity of the intestinal absorptive membrane
No full textInternational audienceIntestine function relies on the strong polarity of intestinal epithelial cells and the array of microvilli forming a brush border at their luminal pole. Combining a genetic RNA interference (RNAi) screen with super-resolution imaging in the intestine, we found that the V0 sector of the vacuolar ATPase (V0-ATPase) controls a late apical trafficking step, involving Ras-related protein 11 (RAB-11) endosomes and the -ethylmaleimide-sensitive factor-attachment protein receptor (SNARE) synaptosome-associated protein 29 (SNAP-29), and is necessary to maintain the polarized localization of both apical polarity modules and brush border proteins. We show that the V0-ATPase pathway also genetically interacts with glycosphingolipids and clathrin in enterocyte polarity maintenance. Finally, we demonstrate that silencing of the V0-ATPase fully recapitulates the severe structural, polarity and trafficking defects observed in enterocytes from individuals with microvillus inclusion disease (MVID) and use this new MVID model to follow the dynamics of microvillus inclusions. Thus, we describe a new function for V0-ATPase in apical trafficking and epithelial polarity maintenance and the promising use of the intestine as an model to better understand the molecular mechanisms of rare genetic enteropathies
Unified preview control for humanoid postural stability and upper-limb interaction adaptation
No full textA distributed model predictive control approach for robust postural stability of a humanoid robot
No full textSur la perte de vitalité du diminutif en français
No full textThis paper considers the subject of the vitality of diminutives in French, lower than in other Romance languages. The author pays special attention to the use of this morpheme in Spanish, where it does have a higher frequency. The diminutive in French would be lexicalised and therefore it would have lost it vitality.El presente artículo trata el tema de la pérdida de vitalidad del diminutivo en lengua francesa, muy inferior a otras lenguas románicas. El autor le presta especial atención al uso de este morfema en el español, donde sí que presenta una mayor frecuencia. El diminutivo del francés se habría lexicalizado y habría perdido su vitalidad.El presente artículo trata el tema de la pérdida de vitalidad del diminutivo en lengua francesa, muy inferior a otras lenguas románicas. El autor le presta especial atención al uso de este morfema en el español, donde sí que presenta una mayor frecuencia. El diminutivo del francés se habría lexicalizado y habría perdido su vitalidad
L’Africain de Le Clézio : Une quête des origines entre images et mots
No full textDans L’Africain, biographie de son père associée à un travail de mémoire sur l’Afrique où Le Clézio a vécu pendant son enfance, l’écrivain se lance dans une véritable enquête sur ses origines. Pour ce faire, il accompagne son récit d’images, une quinzaine en tout, choisies dans la collection de son père, qui s’exprimait plus facilement par la photographie que par les mots. Le Clézio part donc à la rencontre d’une mémoire qui «n’est pas seulement la [sienne]» mais aussi « la mémoire du temps qui a précédé [sa] naissance », et qui s’épanouit dans le jeu parfois problématique, et le plus souvent mystérieux, entre le texte et les images.In L’Africain, a biography of his father and a project on memory and Africa – where Lé Clézio spent his childhood –, the author embarks on a search for his origins. In order to do so, he juxtaposes a narrative with images, roughly fifteen, chosen from his father’s collection, since the latter expressed himself more aptly via photography than through words. Le Clézio therefore searches for a memory that is “not only [his],” and which manifests itself in the occasionally problematic and often mysterious interplay between text and image.En L’Africain, biografía de su padre inspirada por sus recuerdos sobre el África donde Le Clézio vivió en su infancia, el escritor empieza una verdadera búsqueda de sus orígenes. Para facilitarlo, él acompaña su relato de quince imágenes escogidas de la colección de su padre, que se exprimía mejor con la fotografía que con las palabras. Le Clézio se va entonces al encuentro de una memoria que “no es solamente la suya” sino “la memoria del tiempo que precedió su nacimiento,” y que se realiza en el juego a veces problemático y a menudo misterioso, entre el texto y las imágenes
Automatic Optimal Biped Walking as a Mixed-Integer Quadratic Program
No full textInternational audienceThis paper deals with the dynamic control of humanoid robots interacting with their environment, and more specifically the behavioral synthesis for dynamic tasks. The particular problem that is considered here is the sequencing of elementary activities subjected to physical constraints, both internal as torque limits and external as contacts, within the framework of posture/tasks coordination. For that we propose to convert the set of tasks into weighted quadratic functions and to minimize their cost with a Linear Quadratic Program. The combination of elementary tasks leads to complex actions, and the continuous evolution of the weights ensures smooth transitions over time, as it is shown in the results
Risques infectieux liés aux antibactériens : Clostridium difficile et infections fongiques invasives. [Infectious Risks linked to antibacterials: Clostridium difficile and invasive fungal infections.]
No full textNational audienc
Risques infectieux liés aux antibactériens : Clostridium difficile et infections fongiques invasives. [Infectious Risks linked to antibacterials: Clostridium difficile and invasive fungal infections.]
No full textNational audienc
Ubi caritas et amor. Une lecture comparée du Baiser au lépreux et de O Veleiro de Cristal
No full textAbstract. Ubi caritas et amor. A Comparatist Reading of Le Baiser au lépreux and O Veleiro de Cristal. Le Baiser au lépreux (The Kiss to the Leper), by François Mauriac, and O Veleiro de Cristal (The Crystal Sailboat), by José Mauro de Vasconcelos, are a priori aimed at two different audiences. Le Baiser au lépreux is indeed generally considered to be Mauriac’s first important book, whereas O Veleiro de Cristal belongs to “children’s literature”, like O Meu Pé de Laranja Lima (in English “My Sweet Orange Tree”), by the same author, which was very successful in Brazil but also in France. However, the two stories share deep similarities, so we can draw parallels between them. As far as the narrative level is concerned, both of the books tell the story of a human being who suffers because of his physical appearance; Jean Péloueyre in Le Baiser au lépreux and Eduardo in O Veleiro de Cristal are rejected by their close relatives and hide from other people. They try to escape from their painful experience, thanks to the religion in the case of Jean Péloueyre, even if the latter gives rise to an existential drama, and thanks to the imagination in the case of Eduardo, who discovers in the house where his aunt Anna has led him animals who are able to talk. In both stories, eventually, the theme of charity is fundamental: in Mauriac’s novel, Noémi marries Jean and ends up loving him with a love based on charity and that can be defined as agapè, while in O Veleiro de Cristal Anna renounces all vanity to devote herself to her nephew, her charity echoing the one of the animals who live in the Crystal Sailboat.
 
