2,696 research outputs found

    Social cognition in individuals with 22q11.2 deletion syndrome and its link with psychopathology and social outcomes: a review

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    Background: The 22q11.2 deletion syndrome (22q11DS) is a genetic syndrome that results in a highly variable profile of affected individuals of which impairments in the social domain and increased psychopathology are the most prominent. Notably, 25–30% of affected individuals eventually develop schizophrenia/psychosis, predisposing persons with the syndrome to increased risk for this disorder. Because social cognition is considered to underlie social behavior and to be related to psychopathology, this systematic review investigated social cognition in individuals with 22q11DS and examined reported links across its domains with psychopathology and social outcomes. This can provide the basis for a closer understanding of the path from risk to disorder and will inform on the specific domains that can be targeted with preventive intervention strategies. Method: Systematic literature review of studies that reported the links between social cognitive domains and psychopathology and/or social outcomes in individuals with 22q11DS. Electronic databases searched were PubMed and PsycINFO. Results: Defined eligibility criteria identified a total of ten studies to be included in the present review. Selected studies investigated links between two domains of social cognition (emotion processing and theory of mind (ToM)) and psychopathology and/or social outcomes. With respect to the links to psychopathology, two aspects of social cognition were related primarily to negative symptoms. Results regarding the associations to positive and emotional symptoms (anxiety/depression) are limited and require further investigation. Even though both aspects of social cognition were associated with social outcomes, several studies also found no links between these two domains. Both reports invite for an additional examination of reported results and specific considerations regarding chosen constructs. Conclusion: Although equivocal, results of the present review provide sufficient evidence that social cognition is a useful domain for the closer elucidation of clinical outcomes and social difficulties in this population. At the same time, longitudinal studies and consideration of other variables are also necessary for a timely understanding of affected persons in this respect

    Shielding Considerations for CubeSat Structures During Solar Maximum

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    The purpose of this lessons learned paper is to communicate the utility of shielding in small spacecraft planning for the support of mission assurance and reliability. Numerous SmallSats have been flying in polar low Earth orbit for science, communications, technology demonstrations, and imaging with academic, commercial, and government interests. Shielding has been part of mission assurance and reliability from the advent of long duration spacecraft missions. The Shields-1 CubeSat has been operating in polar low Earth orbit since 16 December 2018 with atomic number (Z)-grade radiation shielding and demonstrates shielding effectiveness. Shields-1 has collected a representative example of solar minimum data in 2019 with 8 Teledyne uDosimeters over varying shielding effectivenesses. It serves as current experimental data and has been compared with NOVICE Shielding estimates using the AP8 – AE8 trapped radiation model with the Shields-1 CAD and generic CubeSat 3 unit (U) models. Using NOVICE model radiation analysis coding, the shielding effectivenesses, based on a generic CubeSat 3U structure with 4 electronic boards, were estimated for aluminum wall thicknesses ranging from 0.204-cm to 4.44-cm (0.550-g/cm2 – 12.0-g/cm2) thick aluminum. For modeled polar orbiting spacecraft, solar maximum total ionizing dose (TID) increases by nearly a magnitude for thin-walled aluminum 0.550-g/cm2 - 0.686-g/cm2 (0.204-cm – 0.254-cm) typical CubeSat structures. The shielding effectiveness by NOVICE Sigma estimates, which is a shielding sphere approximation around a detector, showed a linear relationship with wall thickness, which increased over the wall thickness by a ratio of 1.43 determined by linear regression analysis. Using NOVICE Adjoint Monte-Carlo Modeling of solar minimum and solar maximum with the inclusion of a worst-case solar particle event over a 1-year mission without geomagnetic shielding, the TID for minimum and maximum conditions for a generic 3U with a wall thickness of 0.254 cm is 158 RAD and 1540 RAD, respectively. The modeled total solar maximum TID is over estimated, because at low orbital latitudes a spacecraft will have shielding from the Earth’s magnetic field. However, TID will still be significant at high latitudes over the poles, where a spacecraft is exposed in a solar particle event. In contrast, to a thin-walled generic 3U CubeSat, the Shields-1 electronics enclosure has a shielding effectiveness of 21.3 g/cm2 from NOVICE Sigma modeling and is expected to show reduced total ionizing dose increases during the present active Solar Cycle 25 period. Because solar particle events during solar maximum increase TID on electronic parts with thin-walled shielding in short periods of time, it is a mission assurance and reliability consideration on the spacecraft’s mission value versus adding shielding for risk reduction of premature spacecraft or instrument payload loss. Since the volumes of many instruments and system electronics have reduced with small spacecraft, shielding material costs and weight penalties have diminished. A small spacecraft project budget and schedule may limit traditional radiation-hardened part use and radiation testing requirements, where shielding can contribute to mission assurance and reliability with reduced costs

    Removal of organically bound sulfur from oil shale by iron(III)-ion generated-regenerated from pyrite by the action of Acidithiobacillus ferrooxidans

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    Oil shales are one of the alternative sources of hydrocarbon fuels ("synthetic petroleum"), characterized by the increased sulfur and nitrogen content which represent even greater ecological problem in use, compared to classical fuels. Acidithiobacillus ferrooxidans is capable of oxidizing pyrite to iron (III)-ion, providing a strong oxidation agent at low pH. We have used this oxidizing agent for oxidation of sulfur present in DBT as a substrate model to demonstrate its potential to oxidize organically bound sulfur in oil shales. An HCl-concentrate was used as the hydrocarbon matrix. Acidithiobacillus ferrooxidans is already recognized to oxidize the pyritic sulfur component, thereby potentially providing a complete sulfur removal system. By applying GC-MS we established that DBT transformation occurred by oxidation or elimination of sulfur. The products obtained are more soluble in water than parent compounds and this reduces concentration of organic sulfur.BIOHYDROMETALLURY: FROM THE SINGLE CELL TO THE ENVIRONMEN

    Polyphenols and non-alcoholic fatty liver disease: impact and mechanisms:impact and mechanisms

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    Non-alcoholic fatty liver disease (NAFLD) is considered to be the hepatic component of the metabolic syndrome and its prevalence is rapidly increasing due to its strong association with insulin resistance and obesity. At present, given that NAFLD is highly prevalent and therapies are limited, much attention is focused on identifying effective dietary strategies for the prevention and treatment of the disease. Polyphenols are a group of plant bioactive compounds whose regular consumption have been associated with a reduction in the risk of a number of metabolic disorders associated with NAFLD. Here we review the emerging and relatively consistent evidence from cell culture and rodent studies showing that select polyphenols positively modulate a variety of contributors to the NAFLD phenotype, through diverse and complementary mechanisms of action. In particular, the reduction of de novo lipogenesis (via sterol regulatory element-binding protein 1c) and increased fatty acid β-oxidation, presumably involving AMP-activated protein kinase activation, will be discussed. The indirect antioxidant and anti-inflammatory properties of polyphenols which have been reported to contribute to the amelioration of NAFLD will also be addressed. In addition to a direct study of the liver, rodent studies have provided insight into the impact of polyphenols on adipose tissue function and whole body insulin sensitivity, which are likely to in part modulate their impact on NAFLD development. Finally an overview of the limited data from clinical trials will be given along with a discussion of the dose extrapolation from animal studies to human subjects

    Effects of mechanical ventilation at low lung volume on respiratory mechanics and nitric oxide exhalation in normal rabbits

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    Lung mechanics, exhaled NO (NOe), and TNF-(alpha) in serum and bronchoalveolar lavage fluid were assessed in eight closed and eight open chest, normal anesthetized rabbits undergoing prolonged (3-4 h) mechanical ventilation (MV) at low volume with physiological tidal volumes (10 ml/kg). Relative to initial MV on positive end-expiratory pressure (PEEP), MV at low volume increased lung quasi-static elastance (+267 and +281%), airway (+471 and +382%) and viscolelastic resistance (+480 and +294%), and decreased NOe (-42 and -25%) in closed and open chest rabbits, respectively. After restoration of PEEP, viscoelastic resistance returned to control, whereas airway resistance remained elevated (+120 and +31%) and NOe low (-25 and -20%) in both groups of rabbits. Elastance remained elevated (+23%) only in closed-chest animals, being associated with interstitial pulmonary edema, as reflected by increased lung wet-to-dry weight ratio with normal albumin concentration in bronchoalveolar lavage fluid. In contrast, in 16 additional closed- and open-chest rabbits, there were no changes of lung mechanics or NOe after prolonged MV on PEEP only. At the end of prolonged MV, TNF-(alpha) was practically undetectable in serum, whereas its concentration in bronchoalveolar lavage fluid was low and similar in animals subjected or not subjected to ventilation at low volume (62 vs. 43 pg/ml). These results indicate that mechanical injury of peripheral airways due to their cyclic opening and closing during ventilation at low volume results in changes in lung mechanics and reduction in NOe and that these alterations are not mediated by a proinflammatory process, since this is expressed by TNF-(alpha) levels

    Uphill walking at iso-efficiency speeds

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    Uphill walking gait has been extensively studied, but the optimal uphill speed able to enhance the metabolic demand without increasing fatigability has so far received little attention. Therefore, the aim of this study was to assess the metabolic/kinematic demand at constant speed (6 km\ub7h 121 G0 level, G2 2% uphill, G7 7% uphill) and at iso-efficiency speeds (G2IES 5.2 km\ub7h 121 2% uphill and G7IES 3.9 km\ub7h 121 7% uphill). For this aim, physically active women (n:24, Age 33.40 \ub1 4.97 years, BMI 21.62 \ub1 2.06 kg/m-2) after an 8-min warm-up were studied on a treadmill for 10\u2b9 for every walking condition with a 5\u2b9 rest in between. Average heart rate (AVG-HR), rating of perceived exertion (RPE) and kinematic variables (stance time, swing time, stride length, stride cycle, stride-length variability, stride-cycle variability and internal work) were studied. Modif\ufeffications in stance time, stride length and stride cycle (p<0.005), and lower internal-work values (p<0.001) occurred in G7IES in comparison to the other conditions. Swing time was significantly modified only in G7IES compared to G0 and G7 (p<0.001 and p<0.005, respectively). Stride-length variability and stride-cycle variability were higher in G7IES compared to the other conditions (p<0.001). G7 induced the highest AVG-HR (p<0.005) and RPE (p<0.001) compared to the other conditions. This study demonstrates that by applying the equation for uphill walking gait, it is possible to maintain a similar metabolic demand and RPE at iso-efficiency speeds during uphill compared to level walking, inducing at the same time a modification of the kinematic parameters of walking gait performed at the same slope condition

    Can statin preventative treatment inform geroscience-guided therapeutics?

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    : Potential senotherapeutic effect of statins may lead to prevention and reduction of frailty

    Thermal Load of Multidisc Wet Friction Assemblies at Braking Regime

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    The paper presents the results of thermal load investigations of multidisc friction assemblies used as service brakes of a high speed tracked vehicle. By simulating the corresponding braking regimes and measuring the characteristic quantities on an inertial test stand, the relevant parameters of the braking process have been determined. The obtained results have been analyzed and compared to the permitted values of thermal load of the material of the tested friction discs. After a certain number of braking cycles by visual inspection of the brakes the state of the friction elements have been determined. The speed limits for braking the vehicle at higher transmission gear ratios, which may result in a permanent damage of the brakes, have been determined. (C) 2011 Journal of Mechanical Engineering. All rights reserved
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