1,721,003 research outputs found

    Dopamine fails to regulate activation of peripheral blood lymphocytes from multiple sclerosis patients: effects of IFN-beta

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    The neurotransmitter dopamine counteracts T cell functions through its specific receptor subtype D5R but favors T cell proliferation and adhesion when acting on D3R. We found diminished mRNA and protein levels of D5R, but not of D3R, in peripheral blood mononuclear cells (PBMCs) from untreated multiple sclerosis (MS) patients. Dopamine reduced T cell proliferation, secretion of interferon-gamma (IFN-gamma), and production of matrix metalloproteinase-9 (MMP-9) mRNA in PBMCs from controls but not from MS patients. By contrast, reduced levels of D3R and renewed dopamine-associated regulatory functions were found in PBMCs from IFN-beta treated MS patients. Failure of the dopaminergic system of lymphocytes may lessen the threshold of T cell activation and sustain the pathogenic cascade of MS

    Genetic algorithm parameters estimation applied to vehicle powertrain dynamics

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    Typically, in the automotive field, classic estimation or filtering techniques (e.g. Least Squares, Kalman Filter) are used to characterize models. However, in scenarios in which there is a lack of data or some quantities are not available from CAN (Controller Area Network) acquisitions or from datasheets, only simple and poorly accurate models can be obtained. This paper presents an innovative approach that allows avoiding these difficulties: the Genetic Algorithm applied to parameters estimation of powertrain models for the longitudinal dynamic of the vehicle. By employing this technique, parameters estimation is possible even for particularly complex models. The considered approach was tuned and tested in simulation environment showing promising results. Thereafter, the CAN acquired target quantities needed for the minimization, e.g. the engine torque and the wheel speed, and the outputs of the Genetic Algorithm identified model have been compared showing the effectiveness of the proposed approach in real data validation

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    An LPV Approach to Autonomous Vehicle Path Tracking in the Presence of Steering Actuation Nonlinearities

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    This article deals with trajectory tracking for autonomous cars during evasive maneuvers and in the presence of steering actuator nonlinearities. This article develops an LPV MISO H-infinity controller based on the feedback of the lateral error at the center of gravity and the look-ahead distance. The controller architecture offers a way to cope with the effect of the steering nonlinearities, by scheduling one of the control weighting functions. A detailed experimental validation on three different maneuvers (straight driving, wide bend, and a double-lane change) shows the effectiveness of the proposed LPV solution

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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