La thérapie par observation d’action (TOA) dans la maladie de Parkinson

Travail d'intégration réalisé dans le cadre du cours PHT-6113.Problématique: La maladie de Parkinson (MP) est une pathologie neurodégénérative affectant les noyaux gris centraux et est caractérisée par quatre signes moteurs cardinaux: tremblements au repos, bradykinésie/akinésie, rigidité et instabilité posturale. Les symptômes limitent la performance aux tâches fonctionnelles et augmentent le risque de chutes. Actuellement, les interventions en physiothérapie avec les personnes parkinsoniennes sont limitées. La thérapie par observation d’action (TOA) est une approche de rééducation prometteuse. Objectifs: Décrire la physiopathologie de la MP, les outils cliniques pour évaluer les parkinsoniens, les particularités liées aux tâches fonctionnelles et les bases neurophysiologiques sous-tendant la TOA dans le but de déterminer les lignes directrices de cette thérapie auprès des parkinsoniens. Stratégie méthodologique: Les bases EMBASE, MEDLINE, PubMed et Cochrane ont été consultées pour la recension d’articles en lien avec les objectifs. Résultats: Aucun principe d’application de la TOA n’est décrit précisément et aucun consensus n’est établi sur les meilleurs outils d’évaluation à utiliser avec la clientèle parkinsonienne pour mesurer l’effet de la TOA. L’analyse de la littérature permet de suggérer trois tâches fonctionnelles à pratiquer avec la TOA, soit l’atteinte d’une cible avec iii le membre supérieur, le transfert assis-debout et la marche. Il est aussi possible de proposer certaines lignes directrices pour l’évaluation clinique et la mise en pratique de la TOA. Conclusion: Le projet a permis de proposer certaines lignes directrices pour l’utilisation de la TOA chez les parkinsoniens. Ces recommandations seront présentées aux cliniciens afin de les outiller pour appliquer la TOA et étudier ses effets avec cette clientèle

Radii, masses, and ages of 18 bright stars using interferometry and new estimations of exoplanetary parameters

Accurate stellar parameters are needed in numerous domains of astrophysics. The position of stars on the H-R diagram is an important indication of their structure and evolution, and it helps improve stellar models. Furthermore, the age and mass of stars hosting planets are required elements for studying exoplanetary systems. We aim at determining accurate parameters of a set of 18 bright exoplanet host and potential host stars from interferometric measurements, photometry, and stellar models. Using the VEGA/CHARA interferometer, we measured the angular diameters of 18 stars, ten of which host exoplanets. We combined them with their distances to estimate their radii. We used photometry to derive their bolometric flux and, then, their effective temperature and luminosity to place them on the H-R diagram. We then used the PARSEC models to derive their best fit ages and masses, with error bars derived from MC calculations. Our interferometric measurements lead to an average of 1.9% uncertainty on angular diameters and 3% on stellar radii. There is good agreement between measured and indirect estimations of angular diameters (from SED fitting or SB relations) for MS stars, but not as good for more evolved stars. For each star, we provide a likelihood map in the mass-age plane; typically, two distinct sets of solutions appear (an old and a young age). The errors on the ages and masses that we provide account for the metallicity uncertainties, which are often neglected by other works. From measurements of its radius and density, we also provide the mass of 55 Cnc independently of models. From the stellar masses, we provide new estimates of semi-major axes and minimum masses of exoplanets with reliable uncertainties. We also derive the radius, density, and mass of 55 Cnc e, a super-Earth that transits its stellar host. Our exoplanetary parameters reflect the known population of exoplanets.Comment: 23 pages, 9 figures, published in A&A. (This version includes proof corrections.

Reconstruction tomographique d'objets à symétrie de révolution à partir d'une vue par approximation de modèle

Les techniques classiques de reconstruction d'objets axisymétriques génèrent toutes d'importants artefacts (solutions lissées ou très instables). De plus, l'extraction d'informations très précises concernant les grandes transitions de densités demeurent délicates. Dans cet article, nous proposons une nouvelle voie -en une dimension, pour l'instant- assurant simultanément la reconstruction et l'extraction de caractéristiques: un a priori est apporté sous la forme d'un modèle de densités. Nous montrons l'intérêt de cette approche pour ce qui est de la prise en compte ou de la quantification de certaines perturbations induites par la chaîne d'acquisition des données

The Earth as an extrasolar transiting planet: Earth's atmospheric composition and thickness revealed by Lunar eclipse observations

An important goal within the quest for detecting an Earth-like extrasolar planet, will be to identify atmospheric gaseous bio-signatures. Observations of the light transmitted through the Earth's atmosphere, as for an extrasolar planet, will be the first step for future comparisons. We have completed observations of the Earth during a Lunar eclipse, a unique situation similar to that of a transiting planet. We aim at showing what species could be detected in its atmosphere at optical wavelengths, where a lot of photons are available in the masked stellar light. We present observations of the 2008 August 16 Moon eclipse performed with the SOPHIE spectrograph at the Observatoire de Haute-Provence. Locating the spectrograph fibers in the penumbra of the eclipse, the Moon irradiance is then a mix of direct, unabsorbed Sun light and solar light that has passed through the Earth's limb. This mixture essentially reproduces what is recorded during the transit of an extrasolar planet. We report here the clear detection of several Earth atmospheric compounds in the transmission spectra, such as ozone, molecular oxygen, and neutral sodium as well as molecular nitrogen and oxygen through the Rayleigh signature. Moreover, we present a method that allows us to derive the thickness of the atmosphere versus the wavelength for penumbra eclipse observations. We quantitatively evaluate the altitude at which the atmosphere becomes transparent for important species like molecular oxygen and ozone, two species thought to be tightly linked to the presence of life. The molecular detections presented here are an encouraging first attempt, necessary to better prepare for the future of extremely-large telescopes and transiting Earth-like planets. Instruments like SOPHIE will be mandatory when characterizing the atmospheres of transiting Earth-like planets from the ground and searching for bio-marker signatures.Comment: 15 pages, 14 figures, 2 tables. Accepted for publication in Astronomy and Astrophysic

The p.Arg63Trp polymorphism controls Vav1 functions and Foxp3 regulatory T cell development

A single nucleotide polymorphism causing constitutive activation of Vav1 results in increased natural Treg generation and is responsible for the imbalance between Vav1 GEF and adaptor functions

Le numérique éducatif à l'école élémentaire en tension entre politiques nationales, politiques locales et logiques d'appropriation par les enseignants

International audienceCet article rend compte d'un travail de recherche réalisé par le laboratoire Techné de l'université de Poitiers portant sur le numérique éducatif à l'école élémentaire en France métropolitaine. Il découle d'une étude menée entre 2018 et 2019 et dont les principaux résultats ont été transmis à la Cour des comptes dans le cadre d'une contribution à ses travaux sur le sujet. Après une présentation des principaux résultats de l'étude centrale dans la première partie de l'article, les deux parties suivantes proposent d'aborder deux prolongements spécifiques identifiés : les liens entre équipements numériques disponibles et usages des enseignants et la confrontation entre politiques publiques et discours de terrain

A Spontaneous Mutation of the Rat Themis Gene Leads to Impaired Function of Regulatory T Cells Linked to Inflammatory Bowel Disease

Spontaneous or chemically induced germline mutations, which lead to Mendelian phenotypes, are powerful tools to discover new genes and their functions. Here, we report an autosomal recessive mutation that occurred spontaneously in a Brown-Norway (BN) rat colony and was identified as causing marked T cell lymphopenia. This mutation was stabilized in a new rat strain, named BNm for “BN mutated.” In BNm rats, we found that the T cell lymphopenia originated in the thymus, was intrinsic to CD4 T lymphocytes, and was associated with the development of an inflammatory bowel disease. Furthermore, we demonstrate that the suppressive activity of both peripheral and thymic CD4+ CD25bright regulatory T cells (Treg) is defective in BNm rats. Complementation of mutant animals with BN Treg decreases disease incidence and severity, thus suggesting that the impaired Treg function is involved in the development of inflammatory bowel disease in BNm rats. Moreover, the cytokine profile of effector CD4 T cells is skewed toward Th2 and Th17 phenotypes in BNm rats. Linkage analysis and genetic dissection of the CD4 T cell lymphopenia in rats issued from BNm×DA crosses allowed the localization of the mutation on chromosome 1, within a 1.5 megabase interval. Gene expression and sequencing studies identified a frameshift mutation caused by a four-nucleotide insertion in the Themis gene, leading to its disruption. This result is the first to link Themis to the suppressive function of Treg and to suggest that, in Themis-deficient animals, defect of this function is involved in intestinal inflammation. Thus, this study highlights the importance of Themis as a new target gene that could participate in the pathogenesis of immune diseases characterized by chronic inflammation resulting from a defect in the Treg compartment

ESA Voyage 2050 White Paper: Detecting life outside our solar system with a large high-contrast-imaging mission

In this white paper, we recommend the European Space Agency plays a proactive role in developing a global collaborative effort to construct a large high-contrast imaging space telescope, e.g. as currently under study by NASA. Such a mission will be needed to characterize a sizable sample of temperate Earth-like planets in the habitable zones of nearby Sun-like stars and to search for extraterrestrial biological activity. We provide an overview of relevant European expertise, and advocate ESA to start a technology development program towards detecting life outside the Solar system

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe

The JWST Early Release Science Program for the Direct Imaging and Spectroscopy of Exoplanetary Systems

The direct characterization of exoplanetary systems with high-contrast imaging is among the highest priorities for the broader exoplanet community. As large space missions will be necessary for detecting and characterizing exo-Earth twins, developing the techniques and technology for direct imaging of exoplanets is a driving focus for the community. For the first time, JWST will directly observe extrasolar planets at mid-infrared wavelengths beyond 5 μm, deliver detailed spectroscopy revealing much more precise chemical abundances and atmospheric conditions, and provide sensitivity to analogs of our solar system ice-giant planets at wide orbital separations, an entirely new class of exoplanet. However, in order to maximize the scientific output over the lifetime of the mission, an exquisite understanding of the instrumental performance of JWST is needed as early in the mission as possible. In this paper, we describe our 55 hr Early Release Science Program that will utilize all four JWST instruments to extend the characterization of planetary-mass companions to ∼15 μm as well as image a circumstellar disk in the mid-infrared with unprecedented sensitivity. Our program will also assess the performance of the observatory in the key modes expected to be commonly used for exoplanet direct imaging and spectroscopy, optimize data calibration and processing, and generate representative data sets that will enable a broad user base to effectively plan for general observing programs in future Cycles