31 research outputs found

    A wireless sEMG-based body-machine interface for assistive technology devices

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    Assistive technology (AT) tools and appliances are being more and more widely used and developed worldwide to improve the autonomy of people living with disabilities and ease the interaction with their environment. This paper describes an intuitive and wireless surface electromyography (sEMG) based body-machine interface for AT tools. Spinal cord injuries at C5-C8 levels affect patients' arms, forearms, hands, and fingers control. Thus, using classical AT control interfaces (keypads, joysticks, etc.) is often difficult or impossible. The proposed system reads the AT users' residual functional capacities through their sEMG activity, and converts them into appropriate commands using a threshold-based control algorithm. It has proven to be suitable as a control alternative for assistive devices and has been tested with the JACO arm, an articulated assistive device of which the vocation is to help people living with upper-body disabilities in their daily life activities. The wireless prototype, the architecture of which is based on a 3-channel sEMG measurement system and a 915-MHz wireless transceiver built around a low-power microcontroller, uses low-cost off-the-shelf commercial components. The embedded controller is compared with JACO's regular joystick-based interface, using combinations of forearm, pectoral, masseter, and trapeze muscles. The measured index of performance values is 0.88, 0.51, and 0.41 bits/s, respectively, for correlation coefficients with the Fitt's model of 0.75, 0.85, and 0.67. These results demonstrate that the proposed controller offers an attractive alternative to conventional interfaces, such as joystick devices, for upper-body disabled people using ATs such as JACO

    Genetic Evidence Supporting the Association of Protease and Protease Inhibitor Genes with Inflammatory Bowel Disease: A Systematic Review

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    As part of the European research consortium IBDase, we addressed the role of proteases and protease inhibitors (P/PIs) in inflammatory bowel disease (IBD), characterized by chronic mucosal inflammation of the gastrointestinal tract, which affects 2.2 million people in Europe and 1.4 million people in North America. We systematically reviewed all published genetic studies on populations of European ancestry (67 studies on Crohn's disease [CD] and 37 studies on ulcerative colitis [UC]) to identify critical genomic regions associated with IBD. We developed a computer algorithm to map the 807 P/PI genes with exact genomic locations listed in the MEROPS database of peptidases onto these critical regions and to rank P/PI genes according to the accumulated evidence for their association with CD and UC. 82 P/PI genes (75 coding for proteases and 7 coding for protease inhibitors) were retained for CD based on the accumulated evidence. The cylindromatosis/turban tumor syndrome gene (CYLD) on chromosome 16 ranked highest, followed by acylaminoacyl-peptidase (APEH), dystroglycan (DAG1), macrophage-stimulating protein (MST1) and ubiquitin-specific peptidase 4 (USP4), all located on chromosome 3. For UC, 18 P/PI genes were retained (14 proteases and 4protease inhibitors), with a considerably lower amount of accumulated evidence. The ranking of P/PI genes as established in this systematic review is currently used to guide validation studies of candidate P/PI genes, and their functional characterization in interdisciplinary mechanistic studies in vitro and in vivo as part of IBDase. The approach used here overcomes some of the problems encountered when subjectively selecting genes for further evaluation and could be applied to any complex disease and gene family

    Customer emotions in service failure and recovery encounters

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    Emotions play a significant role in the workplace, and considerable attention has been given to the study of employee emotions. Customers also play a central function in organizations, but much less is known about customer emotions. This chapter reviews the growing literature on customer emotions in employee–customer interfaces with a focus on service failure and recovery encounters, where emotions are heightened. It highlights emerging themes and key findings, addresses the measurement, modeling, and management of customer emotions, and identifies future research streams. Attention is given to emotional contagion, relationships between affective and cognitive processes, customer anger, customer rage, and individual differences

    Étude de la structure des protĂ©ines de soie d'araignĂ©e par spectroscopie de vibration

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    Tableau d'honneur de la FacultĂ© des Ă©tudes supĂ©rieures et postdoctorales, 2011-2012Le fil de soie d'araignĂ©e est un matĂ©riau structural ayant des propriĂ©tĂ©s mĂ©caniques de rĂ©sistance et d'endurance exceptionnelles. RĂ©cemment, Nexia Biotechnologies Inc. a rĂ©ussi Ă  produire en grande quantitĂ© les deux protĂ©ines recombinantes (MaSpI et MaSpII) qui composent la soie d'araignĂ©e. Un dĂ©fi important est de pouvoir convertir ces protĂ©ines en biomatĂ©riaux ayant les propriĂ©tĂ©s mĂ©caniques dĂ©sirĂ©es, ces derniĂšres Ă©tant fortement dĂ©pendantes du processus de filage. In vivo, le filage de la soie implique le passage d'une solution protĂ©ique concentrĂ©e contenue dans la glande Ă  travers une filiĂšre conduisant Ă  une fibre insoluble. La conformation des protĂ©ines dans la glande serait dĂ©terminante pour l'optimisation de ce processus. Dans la premiĂšre partie de notre projet, nous avons Ă©tudiĂ© pour la premiĂšre fois la conformation des protĂ©ines de soie d'araignĂ©e in situ Ă  l'intĂ©rieur de la glande ampullacĂ©e majeure ainsi que des deux protĂ©ines recombinantes en solution. À cette fin, nous avons utilisĂ© des techniques sensibles Ă  la conformation des protĂ©ines comme la spectromicroscopie Raman, la spectroscopie infrarouge et le dichroĂŻsme circulaire vibrationnel (VCD). Les donnĂ©es obtenues par VCD montrent la prĂ©sence d'hĂ©lices 3₁ gauche de type polyproline II (PPH), d'hĂ©lices a et de structures dĂ©sordonnĂ©es. La prĂ©sence de PPII pourrait influencer fortement le processus de filage. En effet, les angles diĂšdres de la structure PPII et des feuillets, p Ă©tant proches, la transition d'un Ă©tat Ă  l'autre nĂ©cessiterait peu d'Ă©nergie. La caractĂ©risation des propriĂ©tĂ©s d'auto-assemblage des protĂ©ines recombinantes a Ă©galement Ă©tĂ© effectuĂ©e. Ces rĂ©sultats devraient conduire Ă  une meilleure comprĂ©hension des paramĂštres qui gouvernent le processus de filage naturel des protĂ©ines de soie. Dans la deuxiĂšme partie du projet, nous avons Ă©tudiĂ© par spectromicroscopie Raman la conformation et l'orientation des protĂ©ines de soie dans diffĂ©rents types de fibres produites de l'araignĂ©e Araneus diadematus. Les rĂ©sultats obtenus nous ont permis d'Ă©tablir des corrĂ©lations entre la structure de la soie et les propriĂ©tĂ©s mĂ©caniques des fibres
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