547 research outputs found

    Closed loop identification of systems within cascade connected control strategies

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    A brief review of the background to the Phase-Locked Loop (PLL) method of non-parametric system identification is presented. This introduces the idea of performing the non-parametric identification for any point on the frequency response curve of a process. The PLL identification method is then extended to perform the non-parametric identification of the component parts of a cascade connected control system. An advantage of the method is that the non-parametric identification is performed with the cascade control system connected in closed loop. An example demonstrating the identification method is given

    A human antibody against Zika virus crosslinks the E protein to prevent infection

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    The recent Zika virus (ZIKV) epidemic has been linked to unusual and severe clinical manifestations including microcephaly in fetuses of infected pregnant women and Guillian-Barré syndrome in adults. Neutralizing antibodies present a possible therapeutic approach to prevent and control ZIKV infection. Here we present a 6.2 Å resolution three-dimensional cryo-electron microscopy (cryoEM) structure of an infectious ZIKV (strain H/PF/2013, French Polynesia) in complex with the Fab fragment of a highly therapeutic and neutralizing human monoclonal antibody, ZIKV-117. The antibody had been shown to prevent fetal infection and demise in mice. The structure shows that ZIKV-117 Fabs cross-link the monomers within the surface E glycoprotein dimers as well as between neighbouring dimers, thus preventing the reorganization of E protein monomers into fusogenic trimers in the acidic environment of endosomes

    Trauma Exposure and Transdiagnostic Distress: Examining Shared and PTSD-Specific Associations

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    Dimensional models of psychopathology suggest that the causes and consequences of psychopathology are attributable to a combination of syndrome specific and transdiagnostic features. There is considerable evidence that trauma exposure confers risk for a wide range of psychiatric conditions, yet no previous work has specifically examined the higher-order effects of trauma exposure within a structural model. We examined transdiagnostic and PTSD-specific associations with multiple forms of trauma exposure within a nation-wide sample (N = 1,649; 50% female) of military Veterans over-selected for posttraumatic stress disorder (PTSD). A higher-order Distress variable was estimated using PTSD, major depressive disorder (MDD), and generalized anxiety disorder (GAD) symptoms as indicators. A structural equation model spanning three measurement time points over an average of 3.85 years was then used to examine the unique roles of higher-order Distress and PTSD residual variance in accounting for the relations between trauma exposure and psychosocial impairment. Results suggest that the association between trauma exposure and PTSD symptoms is primarily mediated by higher-order Distress, but that PTSD severity does have a significant association with trauma exposure independent of Distress. Both higher-order Distress and PTSD-specific variance were necessary to account for the association between trauma exposure and future functional impairment. This work suggests there may be shared etiology linking cumulative trauma exposure and a range of internalizing symptoms. Continued application of higher-order dimensional models is needed to provide a more comprehensive understanding of the consequences of trauma exposure

    Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults

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    <p>Abstract</p> <p>Background</p> <p>To determine the effects of supplemental fish oil (FO) on resting metabolic rate (RMR), body composition, and cortisol production in healthy adults.</p> <p>Methods</p> <p>A total of 44 men and women (34 ± 13y, mean+SD) participated in the study. All testing was performed first thing in the morning following an overnight fast. Baseline measurements of RMR were measured using indirect calorimetry using a facemask, and body composition was measured using air displacement plethysmography. Saliva was collected via passive drool and analyzed for cortisol concentration using ELISA. Following baseline testing, subjects were randomly assigned in a double blind manner to one of two groups: 4 g/d of Safflower Oil (SO); or 4 g/d of FO supplying 1,600 mg/d eicosapentaenoic acid (EPA) and 800 mg/d docosahexaenoic acid (DHA). All tests were repeated following 6 wk of treatment. Pre to post differences were analyzed using a treatment X time repeated measures ANOVA, and correlations were analyzed using Pearson's r.</p> <p>Results</p> <p>Compared to the SO group, there was a significant increase in fat free mass following treatment with FO (FO = +0.5 ± 0.5 kg, SO = -0.1 ± 1.2 kg, p = 0.03), a significant reduction in fat mass (FO = -0.5 ± 1.3 kg, SO = +0.2 ± 1.2 kg, p = 0.04), and a tendency for a decrease in body fat percentage (FO = -0.4 ± 1.3% body fat, SO = +0. 3 ± 1.5% body fat, p = 0.08). No significant differences were observed for body mass (FO = 0.0 ± 0.9 kg, SO = +0.2 ± 0.8 kg), RMR (FO = +17 ± 260 kcal, SO = -62 ± 184 kcal) or respiratory exchange ratio (FO = -0.02 ± 0.09, SO = +0.02 ± 0.05). There was a tendency for salivary cortisol to decrease in the FO group (FO = -0.064 ± 0.142 μg/dL, SO = +0.016 ± 0.272 μg/dL, p = 0.11). There was a significant correlation in the FO group between change in cortisol and change in fat free mass (r = -0.504, p = 0.02) and fat mass (r = 0.661, p = 0.001).</p> <p>Conclusion</p> <p>6 wk of supplementation with FO significantly increased lean mass and decreased fat mass. These changes were significantly correlated with a reduction in salivary cortisol following FO treatment.</p

    Curating student employees in academic libraries: Developing workforce skills for their future [Slides]

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    A panel of librarians and library educators presented at the 2019 Association of College and Research Libraries conference in Cleveland, OH about initiatives that provide a variety of opportunities for student library workers to enhance their skills. These projects include workshops for student employees, collaborations with faculty to provide experience with digital projects, and a partnership between the Libraries and the Library and Information Studies Department to offer students applied experiences. The panel discussed the strategic directions behind these programs as well as best practices to implement them and offer professional enhancement for students to prepare them for future careers or graduate education

    Effect of rosiglitazone on progression of atherosclerosis: insights using 3D carotid cardiovascular magnetic resonance

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    <p>Abstract</p> <p>Background</p> <p>There is recent evidence suggesting that rosiglitazone increases death from cardiovascular causes. We investigated the direct effect of this drug on atheroma using 3D carotid cardiovascular magnetic resonance.</p> <p>Results</p> <p>A randomized, placebo-controlled, double-blind study was performed to evaluate the effect of rosiglitazone treatment on carotid atherosclerosis in subjects with type 2 diabetes and coexisting vascular disease or hypertension. The primary endpoint of the study was the change from baseline to 52 weeks of carotid arterial wall volume, reflecting plaque burden, as measured by carotid cardiovascular magnetic resonance. Rosiglitazone or placebo was allocated to 28 and 29 patients respectively. Patients were managed to have equivalent glycemic control over the study period, but in fact the rosiglitazone group lowered their HbA1c by 0.88% relative to placebo (P < 0.001). Most patients received a statin or fibrate as lipid control medication (rosiglitazone 78%, controls 83%). Data are presented as mean ± SD. At baseline, the carotid arterial wall volume in the placebo group was 1146 ± 550 mm<sup>3 </sup>and in the rosiglitazone group was 1354 ± 532 mm<sup>3</sup>. After 52 weeks, the respective volumes were 1134 ± 523 mm<sup>3 </sup>and 1348 ± 531 mm<sup>3</sup>. These changes (-12.1 mm<sup>3 </sup>and -5.7 mm<sup>3 </sup>in the placebo and rosiglitazone groups, respectively) were not statistically significant between groups (P = 0.57).</p> <p>Conclusion</p> <p>Treatment with rosiglitazone over 1 year had no effect on progression of carotid atheroma in patients with type 2 diabetes mellitus compared to placebo.</p

    Solar-electric-propulsion cargo vehicles for split/sprint Mars mission

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    In support of the proposed exploration of Mars, an unmanned cargo ferry SEMM1 (Solar Electric Mars Mission) was designed. The vehicle is based on solar electric propulsion, and required to transport a cargo of 61,000 kg. The trajectory is a combination of spirals; first, out from LEO, then around the sun, then spiral down to low Mars orbit. The spacecraft produces 3.03 MWe power using photovoltaic flexible blanket arrays. Ion thrusters using argon as a propellant were selected to drive the ship, providing about 60 Newtons of thrust in low Earth orbit. The configuration is based on two long truss beams to which the 24 individual, self-deployable, solar arrays are attached. The main body module supports the two beams and houses the computers, electrical, and control equipment. The thruster module is attached to the rear of the main body, and the cargo to the front
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