31 research outputs found

    Assessment of the Accuracy of Cable Sheath Fault Location Device and Enhancement of its Performance

    Get PDF
    As power system networks are being constantly upgraded and extended, there is a greater importance in the reliable transmission of electrical power and fault finding techniques, especially for cables installed underground. Damage to a cable’s protective sheath can damage a cables life span and also lead to disruption of system operation and loss of supply. This study includes research into the literature and techniques used to locate these faults accurately. Bridge resistance and volt drop measurement techniques are the main methods used by sheath fault location devices to locate faults accurately. This task is made more difficult because such devices are hindered by a limited test current. This study carries out an analysis of the accuracy of a leading cable sheath fault location device, which utilizes the volt drop method. Testing was conducted across a series of circuits and a comparison of accuracy was made between this device and a range of measurement devices. After a thorough analysis of test results was carried out, a new method of sheath fault location was developed and examined with the aim of improving fault location accurac

    Retinal Fractal Dimension Is a Potential Biomarker for Systemic Health-Evidence From a Mixed-Age, Primary-Care Population

    Get PDF
    PURPOSE: To investigate whether fractal dimension (FD), a retinal trait relating to vascular complexity and a potential "oculomics" biomarker for systemic disease, is applicable to a mixed-age, primary-care population.METHODS: We used cross-sectional data (96 individuals; 183 eyes; ages 18-81 years) from a university-based optometry clinic in Glasgow, Scotland, to study the association between FD and systemic health. We computed FD from color fundus images using Deep Approximation of Retinal Traits (DART), an artificial intelligence-based method designed to be more robust to poor image quality.RESULTS: Despite DART being designed to be more robust, a significant association (P &lt; 0.001) between image quality and FD remained. Consistent with previous literature, age was associated with lower FD (P &lt; 0.001 univariate and when adjusting for image quality). However, FD variance was higher in older patients, and some patients over 60 had FD comparable to those of patients in their 20s. Prevalent systemic conditions were significantly (P = 0.037) associated with lower FD when adjusting for image quality and age.CONCLUSIONS: Our work suggests that FD as a biomarker for systemic health extends to mixed-age, primary-care populations. FD decreases with age but might not substantially decrease in everyone. This should be further investigated using longitudinal data. Finally, image quality was associated with FD, but it is unclear whether this finding is measurement error caused by image quality or confounded by age and health. Future work should investigate this to clarify whether adjusting for image quality is appropriate.TRANSLATIONAL RELEVANCE: FD could potentially be used in regular screening settings, but questions around image quality remain.</p

    Allopurinol and blood pressure variability following ischemic stroke and transient ischemic attack:a secondary analysis of XILO-FIST

    Get PDF
    Blood Pressure Variability (BPV) is associated with cardiovascular risk and serum uric acid level. We investigated whether BPV was lowered by allopurinol and whether it was related to neuroimaging markers of cerebral small vessel disease (CSVD) and cognition. We used data from a randomised, double-blind, placebo-controlled trial of two years allopurinol treatment after recent ischemic stroke or transient ischemic attack. Visit-to-visit BPV was assessed using brachial blood pressure (BP) recordings. Short-term BPV was assessed using ambulatory BP monitoring (ABPM) performed at 4 weeks and 2 years. Brain MRI was performed at baseline and 2 years. BPV measures were compared between the allopurinol and placebo groups, and with CSVD and cognition. 409 participants (205 allopurinol; 204 placebo) were included in the visit-to-visit BPV analyses. There were no significant differences found between placebo and allopurinol groups for any measure of visit-to-visit BPV. 196 participants were included in analyses of short-term BPV at week 4. Two measures were reduced by allopurinol: the standard deviation (SD) of systolic BP (by 1.30 mmHg (95% confidence interval (CI) 0.18-2.42, p = 0.023)); and the average real variability (ARV) of systolic BP (by 1.31 mmHg (95% CI 0.31-2.32, p = 0.011)). There were no differences in other measures at week 4 or in any measure at 2 years, and BPV was not associated with CSVD or cognition. Allopurinol treatment did not affect visit-to-visit BPV in people with recent ischemic stroke or TIA. Two BPV measures were reduced at week 4 by allopurinol but not at 2 years.</p

    Allopurinol and blood pressure variability following ischemic stroke and transient ischemic attack:a secondary analysis of XILO-FIST

    Get PDF
    Blood Pressure Variability (BPV) is associated with cardiovascular risk and serum uric acid level. We investigated whether BPV was lowered by allopurinol and whether it was related to neuroimaging markers of cerebral small vessel disease (CSVD) and cognition. We used data from a randomised, double-blind, placebo-controlled trial of two years allopurinol treatment after recent ischemic stroke or transient ischemic attack. Visit-to-visit BPV was assessed using brachial blood pressure (BP) recordings. Short-term BPV was assessed using ambulatory BP monitoring (ABPM) performed at 4 weeks and 2 years. Brain MRI was performed at baseline and 2 years. BPV measures were compared between the allopurinol and placebo groups, and with CSVD and cognition. 409 participants (205 allopurinol; 204 placebo) were included in the visit-to-visit BPV analyses. There were no significant differences found between placebo and allopurinol groups for any measure of visit-to-visit BPV. 196 participants were included in analyses of short-term BPV at week 4. Two measures were reduced by allopurinol: the standard deviation (SD) of systolic BP (by 1.30 mmHg (95% confidence interval (CI) 0.18-2.42, p = 0.023)); and the average real variability (ARV) of systolic BP (by 1.31 mmHg (95% CI 0.31-2.32, p = 0.011)). There were no differences in other measures at week 4 or in any measure at 2 years, and BPV was not associated with CSVD or cognition. Allopurinol treatment did not affect visit-to-visit BPV in people with recent ischemic stroke or TIA. Two BPV measures were reduced at week 4 by allopurinol but not at 2 years.</p

    Xanthine oxidase inhibition and white matter hyperintensity progression following ischaemic stroke and transient ischaemic attack (XILO-FIST): a multicentre, double-blinded, randomised, placebo-controlled trial

    Get PDF
    Acknowledgments This work was supported by the Stroke Association and British Heart Foundation [grant number TSA BHF 2013/01]. The work of Dr David Dickie and Dr Terry Quinn is funded by the Stroke Association. We would like to thank Christine McAlpine, Ruth Graham, Glasgow Royal Infirmary, UK; Lauren Pearce, Royal United Hospital, UK; Caroline Fornolles, Louise Tate, Frances Justin, Luton and Dunstable University Hospital, UK; Dean Waugh, Leeds Teaching Hospitals NHS Trust, UK; Donal Concannon, Altnagelvin Hospital, UK; Sharon Tysoe, Nina Francia, Nisha Menon, Raji Prabakaran, Southend University Hospital, UK; Amy Ashton, Caroline Watchurst, Marilena Marinescu, Sabaa Obarey, Scheherazade Feerick, University College London NHS Foundation Trust, UK; and Janice Irvine, Sandra Williams, and German Guzman Gutierrez, Aberdeen Royal Infirmary, UK; Caroline Fox and Joanne Topliffe, Broomfield Hospital, Essex, UK.Peer reviewedPublisher PD

    Xanthine oxidase inhibition and white matter hyperintensity progression following ischaemic stroke and transient ischaemic attack (XILO-FIST): a multicentre, double-blinded, randomised, placebo-controlled trial

    Get PDF
    Background: People who experience an ischaemic stroke are at risk of recurrent vascular events, progression of cerebrovascular disease, and cognitive decline. We assessed whether allopurinol, a xanthine oxidase inhibitor, reduced white matter hyperintensity (WMH) progression and blood pressure (BP) following ischaemic stroke or transient ischaemic attack (TIA). Methods: In this multicentre, prospective, randomised, double-blinded, placebo-controlled trial conducted in 22 stroke units in the United Kingdom, we randomly assigned participants within 30-days of ischaemic stroke or TIA to receive oral allopurinol 300 mg twice daily or placebo for 104 weeks. All participants had brain MRI performed at baseline and week 104 and ambulatory blood pressure monitoring at baseline, week 4 and week 104. The primary outcome was the WMH Rotterdam Progression Score (RPS) at week 104. Analyses were by intention to treat. Participants who received at least one dose of allopurinol or placebo were included in the safety analysis. This trial is registered with ClinicalTrials.gov, NCT02122718. Findings: Between 25th May 2015 and the 29th November 2018, 464 participants were enrolled (232 per group). A total of 372 (189 with placebo and 183 with allopurinol) attended for week 104 MRI and were included in analysis of the primary outcome. The RPS at week 104 was 1.3 (SD 1.8) with allopurinol and 1.5 (SD 1.9) with placebo (between group difference −0.17, 95% CI −0.52 to 0.17, p = 0.33). Serious adverse events were reported in 73 (32%) participants with allopurinol and in 64 (28%) with placebo. There was one potentially treatment related death in the allopurinol group. Interpretation: Allopurinol use did not reduce WMH progression in people with recent ischaemic stroke or TIA and is unlikely to reduce the risk of stroke in unselected people. Funding: The British Heart Foundation and the UK Stroke Association
    corecore