17 research outputs found

    Control of a Gantry-Tau Structure

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    Todays, industrial robots don't correspond to the needs of the Small and Medium sized Enterprises (SME). Indeed, industrial robots are in many cases too hard to program or too expensive to be used by this kind of enterprises. In order to respond to this need, a European project was created, regrouping five major European robot manufacturers and five leading research institute and universities, named SMErobot. Its main task consists of exploiting the potentials of industrial robots, because they constitute the most flexible existing automation technology. This project set to create a radically new type of robot system, a whole family of SME-suitable robots. A new structure of parallel robots was hence designed to respond to these needs, named a Gantry-Tau structure. A prototype of this parallel kinematic structure was created in the Lund Robotics Laboratory, to test its characteristics and the different control methods that can be applied to it. Moreover, it can be use as a demonstration tool. The thesis project concerns the velocity and position control of the small-scale linear actuators which are used for a prototype of the Gantry-Tau robot

    Aux sources de la spĂ©cialisation hĂ©misphĂ©rique cĂ©rĂ©brale du langage : l'intĂ©rĂȘt de l'IRM anatomique chez le babouin

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    La plupart des fonctions cognitives impliquĂ©es dans le langage sont principalement sous le contrĂŽle de l'hĂ©misphĂšre gauche du cerveau au sein d'un rĂ©seau cĂ©rĂ©bral complexe dans lequel les aires de Broca et de Wernicke jouent un rĂŽle clĂ©. Au regard de la proximitĂ© phylogĂ©nĂ©tique des primates humains et non humains, les Ă©tudes sur les asymĂ©tries des systĂšmes de communication de nos cousins les primates peuvent nous aider Ă  dĂ©tecter les prĂ©curseurs Ă©ventuels de cette spĂ©cialisation hĂ©misphĂ©rique du langage chez notre ancĂȘtre commun. Dans nos travaux, les chimpanzĂ©s et les babouins ont montrĂ© des degrĂ©s d’asymĂ©tries en faveur de la main droite pour les gestes communicatifs bien plus prononcĂ©s que ceux rapportĂ©s pour des tĂąches non communicatives de manipulation d’objets. Nous avons ainsi suggĂ©rĂ© l'hypothĂšse selon laquelle la communication gestuelle pourrait impliquer davantage l'hĂ©misphĂšre gauche et constituer ainsi un systĂšme latĂ©ralisĂ© prĂ©curseur de celui du langage chez l'homme. Pour tester cette hypothĂšse, il est important de mener des recherches sur les bases neuronales de ces asymĂ©tries comportementales gestuelles, notamment chez le babouin. Des questions se posent (1) sur l'existence ou non d'asymĂ©tries morphologiques entre l'hĂ©misphĂšre droit et l'hĂ©misphĂšre gauche concernant les zones homologues des aires de Broca et de Wernicke dans le cerveau des babouins, et (2) sur leurs liens potentiels avec les asymĂ©tries des gestes communicatifs. Dans cette prĂ©sentation, nous introduirons nos travaux en neuroimagerie non invasive IRM (Imagerie par rĂ©sonance magnĂ©tique) menĂ©s sur des babouins Papio anubis  anesthĂ©siĂ©s puis remis dans leur groupe social. Ces recherches visent Ă  constituer une base de donnĂ©es la plus large possible d'images cĂ©rĂ©brales anatomiques auprĂšs de sujets hĂ©bergĂ©s et observĂ©s Ă  la station de primatologie de Rousset. Nous ferons le point sur les mĂ©thodes que nous avons dĂ©veloppĂ©es pour collecter des images auprĂšs de sujets in vivo au Centre IRMf de l'Institut des Neurosciences de la Timone Ă  Marseille. Ces mĂ©thodes incluent la prĂ©paration du singe, le protocole d’anesthĂ©sie, l’installation du sujet et son monitoring dans la machine IRM 3Tesla Bruker, ainsi que l'ensemble des Ă©tapes de traitement d'images pour Ă©tudier les corrĂ©lats neuroanatomiques de la communication gestuelle chez le babouin. Un aperçu des premiers rĂ©sultats sera prĂ©sentĂ©

    Compostage et valorisation par l'agriculture des déchets urbains

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    Urban composts constitute a valuable source of organic matter that can be used in agriculture, especially in areas where animal breeding has disappeared. Their use in agriculture is regulated through obligatory standards: NFU 44095 for sludge composts and NFU 44 051 for other organic amendments. These standards assure the innocuousness at short/medium term by limiting the concentrations in trace elements, in organic micropollutants, in pathogens and inerts. Some analytical methods of characterisation have been developed to predict their agronomic value. Long term field experiments are useful tools to evaluate the effects of repeated applications. From the results of the Qualiagro field experiment, the indicator ISMO seems valuable to predict the capacity of organic amendments at increasing soil organic matter contents. Repeated applications of composts have improved soil structure stability, stimulated soil microbial activity, and produced yields equivalent to mineral fertilization. The fluxes of trace elements have reached a few percents of initial soil contents before starting the experiment. After 10 years of experiment, no degradation of grain quality has been noticed nor accumulation of organic micropollutants in soil or sanitary degradation of soils.Les composts d'origine urbaine reprĂ©sentent une source de matiĂšre organique valorisable en agriculture, d’autant plus dans les zones oĂč l'Ă©levage a disparu. Leur utilisation en agriculture est rĂ©glementĂ©e par des normes rendues d'application obligatoire : norme NFU 44 095 pour les composts de boue, norme NFU 44051 pour les autres amendements organiques. Ces normes garantissent l'innocuitĂ© Ă  court et moyen terme en limitant les concentrations en Ă©lĂ©ments traces, composĂ©s traces organiques, inertes et pathogĂšnes. Des mĂ©thodes de caractĂ©risation au laboratoire permettent d'Ă©valuer leur valeur agronomique. Des essais au champ de longue durĂ©e permettent de mesurer les effets de leurs apports rĂ©pĂ©tĂ©s. Au vu des rĂ©sultats de l'essai Qualiagro en Ile de France, l'indicateur ISMO semble prometteur pour prĂ©dire leur capacitĂ© Ă  entretenir la matiĂšre organique des sols. Les apports rĂ©pĂ©tĂ©s de composts amĂ©liorent la stabilitĂ© de la structure du sol. Ils stimulent l'activitĂ© biologique, permettent d’obtenir des rendements Ă©quivalents Ă  ceux obtenus avec une fertilisation minĂ©rale classique. Les flux d'Ă©lĂ©ments traces reprĂ©sentent quelques pourcents des stocks prĂ©sents dans le sol avant Ă©pandage. AprĂšs 10 ans d'essai, aucune dĂ©gradation de la qualitĂ© des grains n'est mesurĂ©e. De mĂȘme aucune accumulation de composĂ©s traces organiques n'est observĂ©e, ni de dĂ©gradation sanitaire des sols

    Impaired Presynaptic High-Affinity Choline Transporter Causes a Congenital Myasthenic Syndrome with Episodic Apnea

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    International audienceThe neuromuscular junction (NMJ) is one of the best-studied cholinergic synapses. Inherited defects of peripheral neurotransmission result in congenital myasthenic syndromes (CMS5), a clinically and genetically heterogeneous group of rare diseases with fluctuating fatigable muscle weakness as the clinical hallmark. Whole-exome sequencing and Sanger sequencing in six unrelated families identified compound heterozygous and homozygous mutations in SLC5A7 encoding the presynaptic sodium-dependent high-affinity choline transporter 1 (CHT), which is known to be mutated in one dominant form of distal motor neuronopathy (DHMN7A). We identified 11 recessive mutations in SLC5A7 that were associated with a spectrum of severe muscle weakness ranging from a lethal antenatal form of arthrogryposis and severe hypotonia to a neonatal form of CMS with episodic apnea and a favorable prognosis when well managed at the clinical level. As expected given the critical role of CHT for multisystemic cholinergic neurotransmission, autonomic dysfunctions were reported in the antenatal form and cognitive impairment was noticed in half of the persons with the neonatal form. The missense mutations induced a near complete loss of function of CHT activity in cell models. At the human NMJ, a delay in synaptic maturation and an altered maintenance were observed in the antenatal and neonatal forms, respectively. Increased synaptic expression of butyrylcholinesterase was also observed, exposing the dysfunction of cholinergic metabolism when CHT is deficient in vivo. This work broadens the clinical spectrum of human diseases resulting from reduced CHT activity and highlights the complexity of cholinergic metabolism at the synapse
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