280 research outputs found

    Identifying intrinsic and reflexive contributions to low-back stabilization

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    Motor control deficits have been suggested as potential cause and/or effect of a-specific chronic low-back pain and its recurrent behavior. Therefore, the goal of this study is to identify motor control in low-back stabilization by simultaneously quantifying the intrinsic and reflexive contributions. Upper body sway was evoked using continuous force perturbations at the trunk, while subjects performed a resist or relax task. Frequency response functions (FRFs) and coherences of the admittance (kinematics) and reflexes (sEMG) were obtained. In comparison with the relax task, the resist task resulted in a 61% decrease in admittance and a 73% increase in reflex gain below 1.1 Hz. Intrinsic and reflexive contributions were captured by a physiologically-based, neuromuscular model, including proprioceptive feedback from muscle spindles (position and velocity) and Golgi tendon organs (force). This model described on average 90% of the variance in kinematics and 39% of the variance in sEMG, while resulting parameter values were consistent over subjects

    Collisional Properties of Cold Spin-Polarized Metastable Neon Atoms

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    We measure the rates of elastic and inelastic two-body collisions of cold spin-polarized neon atoms in the metastable 3P2 state for 20^Ne and 22^Ne in a magnetic trap. From particle loss, we determine the loss parameter of inelastic collisions beta=6.5(18)x10^{-12} cm^3s^{-1} for 20^Ne and beta=1.2(3)x10^{-11}cm^3{s}^{-1} for 22^Ne. These losses are caused by ionizing (i.e. Penning) collisions %to more than and occur less frequently than for unpolarized atoms. This proves the suppression of Penning ionization due to spin-polarization. From cross-dimensional relaxation measurements, we obtain elastic scattering lengths of a=-180(40) a_0 for 20^Ne and a=+150(+80/-50) a_0 for 22^Ne, where a_0=0.0529 nm.Comment: 4 pages, 3 figure

    The true price of meat

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    Copyright © 2010, Instituut voor Milieuvraagstukken Nothing in this publication may be reproduced and/or published by means of print, photocopy, microfilm or any other way without prior written permission of the copyright holder. The true price of mea

    Transparency and (no) more in the Political Advertising Regulation

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    The EU has taken its first steps into a sensitive space by proposing a new Regulation on Political Advertising (RPA). Simply put, the RPA does two things, which this commentary will address in turn. First, it replaces national laws on the transparency of political advertising with a single set of rules. These provide progressively more information to citizens who see an ad, to the public through ad libraries, and to regulators and private actors who are authorised to request information. Second, the RPA tightens the GDPR’s ban on using sensitive data for targeted political advertising. It leaves member states free, however, to further regulate the use of political advertising.The RPA takes a number of important steps in political advertising law. It strengthens the transparency of the (so far largely unregulated) online political advertising environment. It expands ad libraries with information on targeting and funding. And it allows a broad range of private actors (including civil society and journalists) to request data from a broad range of companies (including ad agencies and small platforms). At the same time, the RPA not only represents the EU’s most significant effort to address concerns about political advertising’s democratic impact, but (because it fully harmonises transparency) also shapes how individuals, researchers, and national regulators can scrutinise political advertising. It is therefore important to determine whether the regulation lives up to the Commission’s hype

    Bovine Herpesvirus Type 1 (BHV-1) UL49.5 Luminal Domain Residues 30 to 32 Are Critical for MHC-I Down-Regulation in Virus-Infected Cells

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    Bovine herpesvirus type 1 (BHV-1) UL49.5 inhibits transporter associated with antigen processing (TAP) and down-regulates cell-surface expression of major histocompatibility complex (MHC) class I molecules to promote immune evasion. We have constructed a BHV-1 UL49.5 cytoplasmic tail (CT) null and several UL49.5 luminal domain mutants in the backbone of wild-type BHV-1 or BHV-1 UL49.5 CT- null viruses and determined their relative TAP mediated peptide transport inhibition and MHC-1 down-regulation properties compared with BHV-1 wt. Based on our results, the UL49.5 luminal domain residues 30–32 and UL49.5 CT residues, together, promote efficient TAP inhibition and MHC-I down-regulation functions. In vitro, BHV-1 UL49.5 Δ30–32 CT-null virus growth property was similar to that of BHV-1 wt and like the wt UL49.5, the mutant UL49.5 was incorporated in the virion envelope and it formed a complex with gM in the infected cells

    Role of Innate Immunity in the Pathogenesis of Chronic Rhinosinusitis: Progress and New Avenues

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    Chronic rhinosinusitis is a heterogeneous and multifactorial disease with unknown etiology. Aberrant responses to microorganisms have been suggested to play a role in the pathophysiology of the disease. Research has focused on the presence, detection, response to, and eradication of these potential threats. Main topics seem to center on the contribution of structural cells such as epithelium and fibroblasts, on the consequences of activation of pattern-recognition receptors, and on the role of antimicrobial agents. This research should be viewed not only in the light of a comparison between healthy and diseased individuals, but also in a comparison between patients who do or do not respond to treatment. New players that could play a role in the pathophysiology seem to surface at regular intervals, adding to our understanding (and the complexity) of the disease and opening new avenues that may help fight this incapacitating disease
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