422 research outputs found

    A novel method to determine dynamic temperature trends applied to in-shoe temperature data during walking

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    Body temperature is one of the fundamental measures considered in the assessment of health and wellbeing, with various medical conditions known to give rise to abnormal changes in temperature. In particular, abnormal variations in dynamic temperature patterns during walking or exercise may be linked to a range of foot problems, which are of particular concern in diabetic patients. A number of studies have investigated normative temperature patterns of a population by considering data from multiple participants and averaging results after an acclimatisation interval. In this work we demonstrate that the temperature patterns obtained using such an approach may not be truly representative of temperature changes in a population, and the averaging process adopted may yield skewed results. In this work we propose an alternative approach to determine generic reference temperature patterns based on a minimization of root mean square differences between time-shifted versions of temperature data collected from multiple participants. The results obtained indicate that this approach can yield a general trend that is more representative of actual temperature changes across a population than conventional averaging methods. The method we propose is also shown to better capture and link the effects of underlying factors that influence dynamic temperature trends, which could in turn lead to a better understanding of underlying physiological phenomena

    Predicting filling efficiency of composite resin injection repair

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    We propose to develop a two-dimensional reduced-order reconstruction, simulation and injection strategy to model resin injection repair which is scalable and practical for use with available equipment. The proposed method involves reconstructing a damaged composite laminate using ultrasonic C-scans to determine the damage zone geometry and porosity. The damage zone permeability is calculated via semi-empirical constitutive equations, and used as input data for the CFD simulation of a resin injection process through the composite. The ultimate aim is to guide repair operators by identifying suitable injection configurations in order to improve cavity filling and thus repair efficiency. After establishing the methodology basis, we verify simulations through comparison to a proposed and analytically solved problem. Validation results show a 70+% simulation accuracy. Finally, we create a case study where cavity filling is improved by applying knowledge of the damage zone. This method's ability to predict filling efficacy offers a viable, quantitative and more consistent alternative to existing intuition-based practices for resin injection repair

    Prevalence of PTSD in Survivors of Stroke and Transient Ischemic Attack: A Meta-Analytic Review

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    Background and Purpose Posttraumatic stress disorder (PTSD) is common in survivors of acute life-threatening illness, but little is known about the burden of PTSD in survivors of stroke and transient ischemic attack (TIA). This study estimated the prevalence of stroke or TIA-induced posttraumatic stress disorder (PTSD) using systematic review and meta-analysis. Methods Potentially relevant peer-reviewed journal articles were identified by searching the Ovid MEDLINE, PsycINFO, PILOTS Database, The Cochrane Library and Scopus from inception to January 2013; all searches were conducted on January 31, 2013. Observational cohort studies that assessed PTSD with specific reference to a stroke or TIA that occurred at least 1 month prior to the PTSD assessment were included. PTSD rates and characteristics of the study and sample were abstracted from all included studies. The coding of all articles included demographics, sample size, study country, and method and timing of PTSD assessment. Results Nine studies (N = 1,138) met our inclusion criteria. PTSD rates varied significantly across studies by timing of PTSD assessment (i.e., within 1 year of stroke/TIA versus greater than 1 year post-stroke/TIA; 55% of heterogeneity explained; Q1 = 10.30; P = .001). Using a random effects model, the estimated rate of PTSD following stroke or TIA was 23% (95% CI, 16%–33%) within 1 year of the stroke or TIA and 11% (95% CI, 8%–14%) after 1 year. Conclusions Although PTSD is commonly thought to be triggered by external events such as combat or sexual assault, these results suggest that 1 in 4 stroke or TIA survivors develop significant PTSD symptoms due to the stroke or TIA. Screening for PTSD in a large population-based prospective cohort study with cardiovascular outcome assessments is needed to yield definitive prevalence, and determine whether stroke or TIA-induced PTSD is a risk factor for subsequent cardiovascular events or mortality

    BAP1 and YY1 regulate expression of death receptors in malignant pleural mesothelioma

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    Malignant pleural mesothelioma (MPM) is a rare, aggressive, and incurable cancer arising from the mesothelial lining of the pleura, with few available treatment options. We recently reported loss of function of the nuclear deubiquitinase BRCA1-associated protein 1 (BAP1), a frequent event in MPM, is associated with sensitivity to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. As a potential underlying mechanism, here we report that BAP1 negatively regulates the expression of TRAIL receptors: death receptors 4 (DR4) and 5 (DR5). Using tissue microarrays (TMAs) of tumour samples from MPM patients, we found a strong inverse correlation between BAP1 and TRAIL receptor expression. BAP1 knockdown increased DR4 and DR5 expression, whereas overexpression of BAP1 had the opposite effect. Reporter assays confirmed wild-type BAP1, but not catalytically-inactive mutant BAP1, reduced promoter activities of DR4 and DR5, suggesting deubiquitinase activity is required for the regulation of gene expression. Co-IP studies demonstrated direct binding of BAP1 to the transcription factor Ying Yang 1 (YY1), and ChIP assays revealed BAP1 and YY1 to be enriched in the promoter regions of DR4 and DR5. Knockdown of YY1 also increased DR4 and DR5 expression and sensitivity to TRAIL. These results suggest that BAP1 and YY1 cooperatively repress transcription of TRAIL receptors. Our finding that BAP1 directly regulates the extrinsic apoptotic pathway will provide new insights into the role of BAP1 in the development of MPM and other cancers with frequent BAP1 mutations

    Wavelet-based feature extraction applied to small-angle x-ray scattering patterns from breast tissue: a tool for differentiating between tissue types

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    This paper reports on the application of wavelet decomposition to small-angle x-ray scattering (SAXS) patterns from human breast tissue produced by a synchrotron source. The pixel intensities of SAXS patterns of normal, benign and malignant tissue types were transformed into wavelet coefficients. Statistical analysis found significant differences between the wavelet coefficients describing the patterns produced by different tissue types. These differences were then correlated with position in the image and have been linked to the supra-molecular structural changes that occur in breast tissue in the presence of disease. Specifically, results indicate that there are significant differences between healthy and diseased tissues in the wavelet coefficients that describe the peaks produced by the axial d-spacing of collagen. These differences suggest that a useful classification tool could be based upon the spectral information within the axial peaks

    Confrontation of viewpoints in a concurrent engineering process

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    We present an empirical study aimed at analysing the use of viewpoints in an industrial Concurrent Engineering context. Our focus is on the viewpoints expressed in the argumentative process taking place in evaluation meetings. Our results show that arguments enabling a viewpoint or proposal to be defended are often characterized by the use of constraints. One result involved the way in which the proposals for solutions are assessed during these meetings. We have revealed the existence of specific assessment modes in these meetings as well as their combination. Then, we show that, even if some constraints are apparently identically used by the different specialists involved in meetings, various meanings and weightings are associated with these constraints by these different specialists

    Blast resilience of composite sandwich panels with hybrid glass-fibre and carbon-fibre skins

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    The development of composite materials through hybridisation is receiving a lot of interest; due to the multiple benefits, this may bring to many industries. These benefits include decreased brittle behaviour, which is an inherent weakness for composite materials, and the enhancement of mechanical properties due to the hybrid effect, such as tensile and flexural strength. The effect of implementing hybrid composites as skins on composite sandwich panels is not well understood under high strain rate loading, including blast loading. This paper investigates the blast resilience of two types of hybrid composite sandwich panel against a full-scale explosive charge. Two hybrid composite sandwich panels were mounted at a 15 m stand-off distance from a 100 kg nitromethane charge. The samples were designed to reveal whether the fabric layup order of the skins influences blast response. Deflection of the sandwich panels was recorded using high-speed 3D digital image correlation (DIC) during the blast. It was concluded that the combination of glass-fibre reinforced polymer (GFRP) and carbon-fibre reinforced polymer (CFRP) layers in hybrid laminate skins of sandwich panels decreases the normalised deflection compared to both GFRP and CFRP panels by up to 41 and 23%, respectively. The position of the glass-fibre and carbon-fibre layers does not appear to affect the sandwich panel deflection and strain. A finite element model has successfully been developed to predict the elastic response of a hybrid panel under air blast loading. The difference between the maximum central displacement of the experimental data and numerical simulation was ca. 5% for the hybrid panel evaluated
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