The DIRC Particle Identification System for the BABAR Experiment

A new type of ring-imaging Cherenkov detector is being used for hadronic particle identification in the BABAR experiment at the SLAC B Factory (PEP-II). This detector is called DIRC, an acronym for Detection of Internally Reflected Cherenkov (Light). This paper will discuss the construction, operation and performance of the BABAR DIRC in detail

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

Activité et expérience des acteurs en situation : les apports de l’anthropologie cognitive

International audienceCe chapitre présente le champ des recherches francophones sur l’intervention en Sport et en Education physique qui sont conduites dans le cadre de l’anthropologie cognitive. Inspiré des options théoriques de l’action située (Suchman, 1987), cette orientation consiste à décrire les situations d’intervention en privilégiant une approche compréhensive. L’analyse porte sur l’activité des intervenants (enseignants, entraîneurs, formateurs) et des apprenants en situation d’enseignement, dans le but : d’une part, de décrire leurs comportements en contexte ; d’autre part, d’analyser la façon dont ces acteurs font l’expérience et interprètent les situations de classe pour comprendre les significations qui les organisent en classe.Après une présentation de ces options théoriques, puis des options méthodologiques portant sur une description ethnographique et des entretiens compréhensifs, la suite du chapitre présente trois lignes de résultats d’études conduites dans l’orientation de l’anthropologie cognitive située : a) la dynamique et l’inscription contextuelle de l’activité, b) les phénomènes de typicalisation, de catégorisation perceptive, et de construction des connaissances dans l’activité, et c) les phénomènes de coordination interpersonnelle et d’articulation des activités individuelles. Chaque ligne de résultat s’appuie sur des études qui illustrent l’approche dans le domaine de l’entraînement, de l’enseignement de l’EPS et de la formation

Multi-sensor semantic mapping and exploration of indoor environments

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RGBD object recognition and visual texture classification for indoor semantic mapping

International audienceWe present a mobile robot whose goal is to autonomously explore an unknown indoor environment and to build a semantic map containing high-level information similar to those extracted by humans. This information includes the rooms, their connectivity, the objects they contain and the material of the walls and ground. This robot was developed in order to participate in a French exploration and mapping contest called CAROTTE whose goal is to produce easily interpretable maps of an unknown environment. In particular we present our object detection approach based on a color+depth camera that fuse 3D, color and texture information through a neural network for robust object recognition. We also present the material recognition approach based on machine learning applied to vision. We demonstrate the performances of these modules on image databases and provide examples on the full system working in real environments

Editorial : L'intervention dans les pratiques physiques, sportives et artistiques : Responsabilités et Stratégies des acteurs

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Estrogen-mediated downregulation of AIRE influences sexual dimorphism in autoimmune diseases.

International audienceAutoimmune diseases affect 5% to 8% of the population, and females are more susceptible to these diseases than males. Here, we analyzed human thymic transcriptome and revealed sex-associated differences in the expression of tissue-specific antigens that are controlled by the autoimmune regulator (AIRE), a key factor in central tolerance. We hypothesized that the level of AIRE is linked to sexual dimorphism susceptibility to autoimmune diseases. In human and mouse thymus, females expressed less AIRE (mRNA and protein) than males after puberty. These results were confirmed in purified murine thymic epithelial cells (TECs). We also demonstrated that AIRE expression is related to sexual hormones, as male castration decreased AIRE thymic expression and estrogen receptor α-deficient mice did not show a sex disparity for AIRE expression. Moreover, estrogen treatment resulted in downregulation of AIRE expression in cultured human TECs, human thymic tissue grafted to immunodeficient mice, and murine fetal thymus organ cultures. AIRE levels in human thymus grafted in immunodeficient mice depended upon the sex of the recipient. Estrogen also upregulated the number of methylated CpG sites in the AIRE promoter. Together, our results indicate that in females, estrogen induces epigenetic changes in the AIRE gene, leading to reduced AIRE expression under a threshold that increases female susceptibility to autoimmune diseases