229 research outputs found
Emotirob : from understanding to cognitive interaction
International audienceThe ANR project EmotiRob aims at conceiving and carrying out a soft toy robot which can interact emotionally and cognitively with handicapped and fragile children. However the project MAPH (Active Media For the Handicap) which is an extension of EmotiRob extends the cognitive abilities of the robot so as to implement linguistic interaction with the child. This article presents our work for both projects: speech understanding, emotional interaction, cognitive interaction
Rab27A and its effector MyRIP link secretory granules to F-actin and control their motion towards release sites
The GTPase Rab27A interacts with myosin-VIIa and myosin-Va via MyRIP or melanophilin and mediates melanosome binding to actin. Here we show that Rab27A and MyRIP are associated with secretory granules (SGs) in adrenal chromaffin cells and PC12 cells. Overexpression of Rab27A, GTPase-deficient Rab27A-Q78L, or MyRIP reduced secretory responses of PC12 cells. Amperometric recordings of single adrenal chromaffin cells revealed that Rab27A-Q78L and MyRIP reduced the sustained component of release. Moreover, these effects on secretion were partly suppressed by the actin-depolymerizing drug latrunculin but strengthened by jasplakinolide, which stabilizes the actin cortex. Finally, MyRIP and Rab27A-Q78L restricted the motion of SGs in the subplasmalemmal region of PC12 cells, as measured by evanescent-wave fluorescence microscopy. In contrast, the Rab27A-binding domain of MyRIP and a MyRIP construct that interacts with myosin-Va but not with actin increased the mobility of SGs. We propose that Rab27A and MyRIP link SGs to F-actin and control their motion toward release sites through the actin cortex
Vérification expérimentale de modèles opto-thermo-élastiques simulés avec le logiciel OOFELIE Multiphysics
Experimental validation of opto-thermo-elastic modeling in OOFELIE Multiphysics
The objective of this work is to demonstrate the correlation between a simple laboratory test bench case and the predictions of the Oofelie MultiPhysics software in order to deduce modelling guidelines and improvements. For that purpose two optical systems have been analysed. The first one is a spherical lens fixed in an aluminium barrel, which is the simplest structure found in an optomechanical system. In this study, material characteristics are assumed to be well known: BK7 and aluminium have been retained. Temperature variations between 0 and +60°C from ambient have been applied to the samples. The second system is a YAG laser bar heated by means of a dedicated oven.
For the two test benches thermo-elastic distortions have been measured using a Fizeau interferometer. This sensor measures wavefront error in the range of 20 nm to 1 μm without physical contact with the optomechanical system. For the YAG bar birefringence and polarization measurements have also been performed using a polarimetric bench.
The tests results have been compared to the predictions obtained by Oofelie MultiPhysics which is a multiphysics toolkit treating coupled problems of optics, mechanics, thermal physics, electricity, electromagnetism, acoustics and hydrodynamics. From this comparison modelling guidelines have been issued with the aim of improving the accuracy of computed thermo-elastic distortions and their impact on the optical performances
Deformed strings in the Heisenberg model
We investigate solutions to the Bethe equations for the isotropic S = 1/2
Heisenberg chain involving complex, string-like rapidity configurations of
arbitrary length. Going beyond the traditional string hypothesis of undeformed
strings, we describe a general procedure to construct eigenstates including
strings with generic deformations, discuss general features of these solutions,
and provide a number of explicit examples including complete solutions for all
wavefunctions of short chains. We finally investigate some singular cases and
show from simple symmetry arguments that their contribution to zero-temperature
correlation functions vanishes.Comment: 34 pages, 13 figure
New reactor dedicated to in operando studies of model catalysts by means of surface x-ray diffraction and grazing incidence small angle x-ray scattering
International audienceA new experimental setup has been developed to enable in situ studies of catalyst surfaces during chemical reactions by means of surface x-ray diffraction (SXRD) and grazing incidence small angle x-ray scattering. The x-ray reactor chamber was designed for both ultrahigh-vacuum (UHV) and reactive gas environments. A laser beam heating of the sample was implemented; the sample temperature reaches 1100 K in UHV and 600 K in the presence of reactive gases. The reactor equipment allows dynamical observations of the surface with various, perfectly mixed gases at controlled partial pressures. It can run in two modes: as a bath reactor in the pressure range of 1-1000 mbars and as a continuous flow cell for pressure lower than 10−3 mbar. The reactor is connected to an UHV preparation chamber also equipped with low energy electron diffraction and Auger spectroscopy. This setup is thus perfectly well suited to extend in situ studies to more complex surfaces, such as epitaxial films or supported nanoparticles. It offers the possibility to follow the chemically induced changes of the morphology, the structure, the composition, and growth processes of the model catalyst surface during exposure to reactive gases. As an example the Pd8Ni92(110) surface structure was followed by SXRD under a few millibars of hydrogen and during butadiene hydrogenation while the reaction was monitored by quadrupole mass spectrometry. This experiment evidenced the great sensitivity of the diffracted intensity to the subtle interaction between the surface atoms and the gas molecules
Resultados de la tercera temprada de campo 2001 del proyecto Peten noroccidente - La Joyanca, la libertad, Peten
International audienceSe presenta la información arqueológica y geográfica más reciente recuperada en el Noroccidente de Petén a través de investigaciones sistemáticas realizadas tanto en el centro y la periferia del sitio arqueológico La Joyanca como en la región circundante, proponiendo una visión de carácter local y regional. En general, ha existido una laguna de información y excavaciones en esta región de la tierras bajas mayas. Dichas investigaciones aqui resumidas en la presente ponencia aportan nuevos datos sobre las formas del asentamiento de La Joyanca, una "ciudad" de tercer orden, y de otros sitios estudiados en la región
Sharing efforts for modelling plant systems: from publications to reusable software components
http://www-sop.inria.fr/virtualplants/Publications/2009/FPCBLRCCBMSVEAG09/[email protected] audiencePlant models become increasingly complex and their implementation often implies the use of advanced techniques in computer science. This evolution has been accompanied by the production of dedicated plant modelling tools, such as simulation platforms, that facilitate research in this field. However, much less sharing is observed for plant models themselves, that is for computer programs produced by scientists to address their specific questions. Yet, these programs could be highly valuable for other researchers, to avoid redundant development of similar code or to help non-specialists to simulate parts of a complex system. Model descriptions found in academic publications, even combined with code sources, are generally not sufficient for model reuse. Most difficulties come from the heterogeneity of language used, the structure of the programs, the download and installation procedures, the accessibility to the source code of the model, and the availability of documentation. The OpenAlea initiative (http://openalea.gforge.inria.fr) has been launched to address these problems by providing plant modellers with collaborative tools and guidelines to increase software quality, hence re-usability of their models. The Alinea pilot project further tested these concepts in a sample community of ecophysiologists and biophysicists. Based on this experience, we illustrate pros and cons of the approach and discuss future direction of progress. We foresee three steps towards a better re-usability of models: a better interoperability of existing tools and simulation platforms, the emergence of design patterns for plant modelling, and the definition of standardised data structures
a planned ancillary analysis of the coVAPid cohort
Funding: This study was supported in part by a grant from the French government through the «Programme Investissement d’Avenir» (I-SITE ULNE) managed by the Agence Nationale de la Recherche (coVAPid project). The funders of the study had no role in the study design, data collection, analysis, or interpreta tion, writing of the report, or decision to submit for publication.BACKGROUND: Patients with SARS-CoV-2 infection are at higher risk for ventilator-associated pneumonia (VAP). No study has evaluated the relationship between VAP and mortality in this population, or compared this relationship between SARS-CoV-2 patients and other populations. The main objective of our study was to determine the relationship between VAP and mortality in SARS-CoV-2 patients. METHODS: Planned ancillary analysis of a multicenter retrospective European cohort. VAP was diagnosed using clinical, radiological and quantitative microbiological criteria. Univariable and multivariable marginal Cox's regression models, with cause-specific hazard for duration of mechanical ventilation and ICU stay, were used to compare outcomes between study groups. Extubation, and ICU discharge alive were considered as events of interest, and mortality as competing event. FINDINGS: Of 1576 included patients, 568 were SARS-CoV-2 pneumonia, 482 influenza pneumonia, and 526 no evidence of viral infection at ICU admission. VAP was associated with significantly higher risk for 28-day mortality in SARS-CoV-2 (adjusted HR 1.70 (95% CI 1.16-2.47), p = 0.006), and influenza groups (1.75 (1.03-3.02), p = 0.045), but not in the no viral infection group (1.07 (0.64-1.78), p = 0.79). VAP was associated with significantly longer duration of mechanical ventilation in the SARS-CoV-2 group, but not in the influenza or no viral infection groups. VAP was associated with significantly longer duration of ICU stay in the 3 study groups. No significant difference was found in heterogeneity of outcomes related to VAP between the 3 groups, suggesting that the impact of VAP on mortality was not different between study groups. INTERPRETATION: VAP was associated with significantly increased 28-day mortality rate in SARS-CoV-2 patients. However, SARS-CoV-2 pneumonia, as compared to influenza pneumonia or no viral infection, did not significantly modify the relationship between VAP and 28-day mortality. CLINICAL TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov, number NCT04359693.publishersversionpublishe
Au pays maya des lacs et des marais recherches archéologiques et géographiques (1999-2001)
National audienceLes sociétés mayas des hautes terres ont connu un déclin culturel marqué à la fin du Préclassique (vers 100-250 apr. JC) au moment où, pour la plupart, les cités mayas des basses terres prenaient leur essor au début du Classique (250-300 apr. J.C.). Environ 600 ans plus tard, celles du Petén (Guatemala) étaient presque toutes abandonnées alors que celles des basses terres du nord connaissaient leur apogée jusqu'au début du Postclassique. En termes géographiques, il s'agit d'analyser l'évolution d'anthropo-systèmes formés en forêt tropicale humide de mousson, soit une des rares zones où s'est développée dans le passé une civilisation puissante, agricole et urbaine sur une longue durée. Le projet Petén nord-ouest La Joyanca a pour objet l'étude d'une communauté socio-politique de rang moyen, d'époque classique, située dans une région des basses terres jusqu'à présent quasiment inconnue du point de vue archéologique. Ce projet est particulier, d'une part car il associe une approche archéologique et géographique, cherchant à restituer l'histoire des hommes en même temps que l'histoire du milieu, d'autre part parce que l'initiative de cette recherche et son financement proviennent d'une compagnie pétrolière. Ce site de la Joyanca apporte des éléments nouveaux dans le corpus des "cités" mayas classiques des basses terres du Petén : désintégration du centre politico-religieux et des ensembles de palais, association étroite au centre, dans le temps et dans l'espace, des lieux de culte et d'un grand édifice politique complexe, faible densité de l'habitat
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