2,218 research outputs found

    Screen time is associated with adiposity and insulin resistance in children

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    Higher screen time is associated with type 2 diabetes (T2D) risk in adults, but the association with T2D risk markers in children is unclear. We examined associations between self-reported screen time and T2D risk markers in children. Survey of 4495 children aged 9-10 years who had fasting cardiometabolic risk marker assessments, anthropometry measurements and reported daily screen time; objective physical activity was measured in a subset of 2031 children. Compared with an hour or less screen time daily, those reporting screen time over 3 hours had higher ponderal index (1.9%, 95% CI 0.5% to 3.4%), skinfold thickness (4.5%, 0.2% to 8.8%), fat mass index (3.3%, 0.0% to 6.7%), leptin (9.2%, 1.1% to 18.0%) and insulin resistance (10.5%, 4.9% to 16.4%); associations with glucose, HbA1c, physical activity and cardiovascular risk markers were weak or absent. Associations with insulin resistance remained after adjustment for adiposity, socioeconomic markers and physical activity. Strong graded associations between screen time, adiposity and insulin resistance suggest that reducing screen time could facilitate early T2D prevention. While these observations are of considerable public health interest, evidence from randomised controlled trials is needed to suggest causality. [Abstract copyright: Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

    Effect of Platelet Length and Stochastic Morphology on Flexural Behavior of Prepreg Platelet Molded Composites

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    Prepreg platelet molding compound (PPMC) can be used to create structural grade material with a heterogeneous mesoscale morphology. The present work considered various platelet lengths of the prepreg system IM7/8552 to study the effect of platelet length on the flexural behavior of PPMC composite. A progressive failure finite-element analysis was used to understand competing failure modes in PPMC with the different platelet length. The interlaminar and in-plane damage mechanisms were employed to describe complex failure modes within the mesostructure of PPMCs. Experimental results of the flexural tests of the PPMC with different platelet length sizes were used to validate the modeling prediction. The experimental and modeling results revealed complex behavior of the flexural mechanical properties (modulus and strength) on the platelet length. The experimental results indicate that PPMC composites processed with a plate length of 12.7 mm have a higher flexural modulus and strength than 25.4 and 6.35 mm. The platelet length effect on the flexural mechanical behavior was attributed to interactions between various damage mechanisms and the stochastic fiber orientation distribution variability in the material

    Shape Evasion: Preventing Body Shape Inference of Multi-Stage Approaches

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    Modern approaches to pose and body shape estimation have recently achieved strong performance even under challenging real-world conditions. Even from a single image of a clothed person, a realistic looking body shape can be inferred that captures a users' weight group and body shape type well. This opens up a whole spectrum of applications -- in particular in fashion -- where virtual try-on and recommendation systems can make use of these new and automatized cues. However, a realistic depiction of the undressed body is regarded highly private and therefore might not be consented by most people. Hence, we ask if the automatic extraction of such information can be effectively evaded. While adversarial perturbations have been shown to be effective for manipulating the output of machine learning models -- in particular, end-to-end deep learning approaches -- state of the art shape estimation methods are composed of multiple stages. We perform the first investigation of different strategies that can be used to effectively manipulate the automatic shape estimation while preserving the overall appearance of the original image

    Spray Deposition of Sustainable Plant Based Graphene in Thermosetting Carbon Fiber Laminates for Mechanical, Thermal, and Electrical Properties

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    Graphene has generated substantial interest as a filler due to its exceptional strength, flexibility, and conductivity but faces obstacles in supply and implementation. A renewable, plant-based graphene nanoparticle (pGNP) presents a more accessible filler with the same properties as mineral graphenes. In this study, we examine the effects of pGNP, which was sprayed on a carbon fiber/epoxy prepreg at loadings from 1.1 to 4.2 g/m2. The study considered the mechanical, thermal, and electrical properties of pGNP-composite. An even particle dispersion was achieved using a spray application of pGNP in a water/alcohol suspension with the addition of surfactants and dispersion aides. Results show that pGNP addition increases flexural modulus 15%, flexural strength 17%, interlaminar shear strength 17%, and mode I fracture toughness by 146%, as well as increases electrical conductivity 294% and thermal conductivity 24%, with these improvements observed at 1.1–2.3 g/m2 spray loadings

    Dependence of Carbon Nanotube Field Effect Transistors Performance on Doping Level of Channel at Different Diameters: On/off current ratio

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    Choosing a suitable doping level of channel relevant to channel diameter is considered for determining the carbon nanotube field effect transistors' performance which seem to be the best substitute of current transistor technology. For low diameter values of channel the ratio of on/off current declines by increasing the doping level. But for higher diameter values there is an optimum point of doping level in obtaining the highest on/off current ratio. For further verification, the variations of performance are justified by electron distribution function's changes on energy band diagram of these devices. The results are compared at two different gate fields.Comment: 9 double spaced pages, 4 figures, published in applied physics letters, along with the terms of the American Institute of Physics Transfer of Copyright Agreement at first pag

    Validation of Acoustic Emission Waveform Entropy as a Damage Identification Feature

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    The increase in the market for supersized LNG (liquefied natural gas) vessels, with double wall cargo tanks, has led to concerns regarding their safe operation. If both the primary and secondary wall of the cargo tank fail simultaneously, the hull of the vessel can be exposed to the LNG. This has the potential to cause brittle failure of the hull structure. This study presents a new acoustic emission (AE) technique approach that can be implemented for monitoring the structural condition of the cargo containment. The new technique approach is based on a feature of the AE waveform, calculated using quadratic Renyi’s entropy. The presented technique is capable of providing information regarding critical damage so that appropriate maintenance can be carried out to avoid failure. The new AE technique is based on an AE feature that is independent of acquisition settings (e.g., threshold and timing), unlike many traditional AE features. The effectiveness of the proposed feature was evaluated by comparison with traditional AE features under ideal conditions for a range of varying acquisition settings. Unlike the traditional feature, the new feature demonstrated no variance with variation of the acquisition settings and was effective in capturing the collective information in the waveform. The proposed AE feature was validated through tensile and fatigue testing on standard specimens of austenitic stainless steel (material of the primary wall). The results suggest that the proposed AE feature is sensitive in identifying the critical damages irrespective of some data acquisition settings

    The metabolic syndrome adds utility to the prediction of mortality over its components: The Vietnam Experience Study

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    Background\ud The metabolic syndrome increases mortality risk. However, as “non-affected” individuals may still have up to two risk factors, the utility of using three or more components to identify the syndrome, and its predictive advantage over individual components have yet to be determined.\ud \ud Methods\ud Participants, male Vietnam-era veterans (n = 4265) from the USA, were followed-up from 1985/1986 for 14.7 years (61,498 person-years), and all-cause and cardiovascular disease deaths collated. Cox's proportional-hazards regression was used to assess the effect of the metabolic syndrome and its components on mortality adjusting for a wide range of potential confounders.\ud \ud Results\ud At baseline, 752 participants (17.9%) were identified as having metabolic syndrome. There were 231 (5.5%) deaths from all-causes, with 60 from cardiovascular disease. After adjustment for a range of covariates, the metabolic syndrome increased the risk of all-cause, HR 2.03, 95%CI 1.52, 2.71, and cardiovascular disease mortality, HR 1.92, 95%CI 1.10, 3.36. Risk increased dose-dependently with increasing numbers of components. The increased risk from possessing only one or two components was not statistically significant. The adjusted risk for four or more components was greater than for only three components for both all-cause, HR 2.30, 95%CI 1.45, 3.66 vs. HR 1.70, 95%CI 1.11, 2.61, and cardiovascular disease mortality, HR 3.34, 95%CI 1.19, 9.37 vs. HR 2.81, 95%CI 1.07, 7.35. The syndrome was more informative than the individual components for all-cause mortality, but could not be assessed for cardiovascular disease mortality due to multicollinearity. Hyperglycaemia was the individual strongest parameter associated with mortality.\ud \u

    Cardiovascular biomarkers and vascular function during childhood in the offspring of mothers with hypertensive disorders of pregnancy: findings from the Avon Longitudinal Study of Parents and Children

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    <p><b>Aims:</b> It is uncertain if the higher blood pressure (BP) observed in the offspring of hypertensive pregnancies is an isolated abnormality or one that is accompanied by impaired vascular function and alterations in lipid and inflammation markers that would be indicative of a more general cardiometabolic disturbance of the type observed in the mother during pre-eclampsia.</p> <p><b>Methods and results:</b> In a large UK cohort of maternal-offspring pairs (n = 3537–4654), assessed at age 9–12 years, we examined the associations of maternal gestational hypertension and pre-eclampsia with offspring BP, endothelial function assessed by brachial artery flow-mediated dilatation; arterial stiffness assessed by carotid to radial pulse wave velocity; brachial artery distensibility and BP (vascular outcomes); as well as markers of inflammation, lipids and apolipoproteins A1 and B. Offspring of women with pre-eclampsia or gestational hypertension had higher systolic blood pressure by 2.04 mmHg (95% CI: 1.33, 2.76) and 1.82 mmHg (95% CI: 0.03, 3.62), respectively, and higher diastolic blood pressure by 1.10 mmHg (95% CI: 0.47, 1.73) and 1.26 mmHg (95% CI: −0.32, 2.85), respectively, in analyses adjusted for maternal and offspring body mass index (BMI), offspring dietary sodium intake and other potential confounders. However, we found no associations of either hypertensive disorder of pregnancy with the other vascular outcomes or with inflammatory markers, lipids, and apolipoproteins.</p> <p><b>Conclusion:</b> Pre-eclampsia and gestational hypertension are associated with higher offspring BP in childhood in the absence of other vascular alterations or metabolic derangements. The findings support the existence of shared mother-offspring risk factors that are specific for higher BP, rather than the additional cardiometabolic abnormalities of hypertensive disorder of pregnancy having long-term consequences for offspring.</p&gt
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