108 research outputs found

    Conformal GaP layers on Si wire arrays for solar energy applications

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    We report conformal, epitaxial growth of GaP layers on arrays of Si microwires. Silicon wires grown using chlorosilane chemical vapor deposition were coated with GaP grown by metal-organic chemical vapor deposition. The crystalline quality of conformal, epitaxial GaP/Si wire arrays was assessed by transmission electron microscopy and x-ray diffraction. Hall measurements and photoluminescence show p- and n-type doping with high electron mobility and bright optical emission. GaP pn homojunction diodes on planar reference samples show photovoltaic response with an open circuit voltage of 660 mV

    Effects of different lighting arrangements on space perception

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    The idea to improve the quality of lighting design in interior spaces has gained importance in the last years. This experimental study concentrateson the quality of lighting and the relation between lighting arrangements and perception. A room having four different lighting arrangements was prepared and the differences between the perception of the participants under each lighting arrangement was analysed. The results suggested that different lighting arrangements affect perception. Wall washing enhanced the impressions of clarity and order, cove lighting enhanced spaciousness and order and uplighting made the same space relaxing, private and pleasant

    Solving Sudoku from an Image using Modular Architecture Approach

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    Sudoku puzzles can be found in various physical forms in newspapers, magazines and elsewhere. It may often be desirable to convert this puzzle into a digital format for ease of solving. This paper proposes a method for extracting and solving a Sudoku puzzle captured in an image. AI techniques can then be applied to solve the Sudoku puzzle. A modular architecture is created for this purpose. Modules can be replaced as needed, making it easier to improve and maintain an application using the proposed architecture DOI: 10.17762/ijritcc2321-8169.150312

    GaP/Si wire array solar cells

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    Si wire arrays have recently demonstrated their potential as photovoltaic devices [1-3]. Using these arrays as a base, we consider a next generation, multijunction wire array architecture consisting of Si wire arrays with a conformal GaN_xP_(1-x-y)As_y coating. Optical absorption and device physics simulations provide insight into the design of such devices. In particular, the simulations show that much of the solar spectrum can be absorbed as the angle of illumination is varied and that an appropriate choice of coating thickness and composition will lead to current matching conditions and hence provide a realistic path to high efficiencies. We have previously demonstrated high fidelity, high aspect ratio Si wire arrays grown by vapor-liquid-solid techniques, and we have now successfully grown conformal GaP coatings on these wires as a precursor to considering quaternary compound growth. Structural, optical, and electrical characterization of these GaP/Si wire array heterostructures, including x-ray diffraction, Hall measurements, and optical absorption of polymer-embedded wire arrays using an integrating sphere were performed. The GaP epilayers have high structural and electrical quality and the ability to absorb a significant amount of the solar spectrum, making them promising for future multijunction wire array solar cells

    Exclusively cephalic venous access for cardiac resynchronisation: A prospective multi-centre evaluation.

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    BACKGROUND: Small series has shown that cardiac resynchronisation therapy (CRT) can be achieved in a majority of patients using exclusively cephalic venous access. We sought to determine whether this method is suitable for widespread use. METHODS: A group of 19 operators including 11 trainees in three pacing centres attempted to use cephalic access alone for all CRT device implants over a period of 8 years. The access route for each lead, the procedure outcome, duration, and complications were collected prospectively. Data were also collected for 105 consecutive CRT device implants performed by experienced operators not using the exclusively cephalic method. RESULTS: A new implantation of a CRT device using exclusively cephalic venous access was attempted in 1091 patients (73.6% male, aged 73 ± 12 years). Implantation was achieved using cephalic venous access alone in 801 cases (73.4%) and using a combination of cephalic and other access in a further 180 (16.5%). Cephalic access was used for 2468 of 3132 leads implanted (78.8%). Compared to a non-cephalic reference group, complications occurred less frequently (69/1091 vs 12/105; P = .0468), and there were no pneumothoraces with cephalic implants. Procedure and fluoroscopy duration were shorter (procedure duration 118 ± 45 vs 144 ± 39 minutes, P < .0001; fluoroscopy duration 15.7 ± 12.9 vs 22.8 ± 12.2 minutes, P < .0001). CONCLUSIONS: CRT devices can be implanted using cephalic access alone in a substantial majority of cases. This approach is safe and efficient

    Rationale and study design of the MINERVA study: Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction-UK multicentre collaboration

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    Introduction The purpose of this study is to assess the ability of two new ECG markers (Regional Repolarisation Instability Index (R2I2) and Peak Electrical Restitution Slope) to predict sudden cardiac death (SCD) or ventricular arrhythmia (VA) events in patients with ischaemic cardiomyopathy undergoing implantation of an implantable cardioverter defibrillator for primary prevention indication. Methods and analysis Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction is a prospective, open label, single blinded, multicentre observational study to establish the efficacy of two ECG biomarkers in predicting VA risk. 440 participants with ischaemic cardiomyopathy undergoing routine first time implantable cardioverter-defibrillator (ICD) implantation for primary prevention indication are currently being recruited. An electrophysiological (EP) study is performed using a non-invasive programmed electrical stimulation protocol via the implanted device. All participants will undergo the EP study hence no randomisation is required. Participants will be followed up over a minimum of 18 months and up to 3 years. The first patient was recruited in August 2016 and the study will be completed at the final participant follow-up visit. The primary endpoint is ventricular fibrillation or sustained ventricular tachycardia >200 beats/min as recorded by the ICD. The secondary endpoint is SCD. Analysis of the ECG data obtained during the EP study will be performed by the core lab where blinding of patient health status and endpoints will be maintained. Ethics and dissemination Ethical approval has been granted by Research Ethics Committees Northern Ireland (reference no. 16/NI/0069). The results will inform the design of a definitive Randomised Controlled Trial (RCT). Dissemination will include peer reviewed journal articles reporting the qualitative and quantitative results, as well as presentations at conferences and lay summaries

    Association of Polygenic Liability for Alcohol Dependence and EEG Connectivity in Adolescence and Young Adulthood

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    Differences in the connectivity of large-scale functional brain networks among individuals with alcohol use disorders (AUD), as well as those at risk for AUD, point to dysfunctional neural communication and related cognitive impairments. In this study, we examined how polygenic risk scores (PRS), derived from a recent GWAS of DSM-IV Alcohol Dependence (AD) conducted by the Psychiatric Genomics Consortium, relate to longitudinal measures of interhemispheric and intrahemispheric EEG connectivity (alpha, theta, and beta frequencies) in adolescent and young adult offspring from the Collaborative Study on the Genetics of Alcoholism (COGA) assessed between ages 12 and 31. Our findings indicate that AD PRS (p-threshold < 0.001) was associated with increased fronto-central, tempo-parietal, centro-parietal, and parietal-occipital interhemispheric theta and alpha connectivity in males only from ages 18-31 (beta coefficients ranged from 0.02-0.06, p-values ranged from 10-6-10-12), but not in females. Individuals with higher AD PRS also demonstrated more performance deficits on neuropsychological tasks (Tower of London task, visual span test) as well as increased risk for lifetime DSM-5 alcohol and opioid use disorders. We conclude that measures of neural connectivity, together with neurocognitive performance and substance use behavior, can be used to further understanding of how genetic risk variants from large GWAS of AUD may influence brain function. In addition, these data indicate the importance of examining sex and developmental effects, which otherwise may be masked. Understanding of neural mechanisms linking genetic variants emerging from GWAS to risk for AUD throughout development may help to identify specific points when neurocognitive prevention and intervention efforts may be most effective

    Diabetes Health, Residence & Metabolism in Asians: the DHRMA study, research into foods from the Indian subcontinent - a blinded, randomised, placebo controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Coronary heart disease (CHD) is highly prevalent amongst the South Asian communities in Britain. The reasons for this excess CHD risk are multifactorial, but in part relate to a susceptibility to diabetes mellitus - where the aberrant metabolism of non-esterified fatty acids (NEFA) and glucose are likely to underpin vascular disease in this population. Dietary intervention is an important and first line approach to manage increased CHD risk. However, there is limited information on the impact of the South Asian diet on CHD risk.</p> <p>Methods/Design</p> <p>The Diabetes Health, Residence & Metabolism in Asians (DHRMA) study is a blinded, randomised, placebo controlled trial that analyses the efficacy of reduced glycaemic index (GI) staples of the South Asian diet, in relation to cardio-metabolic risk factors that are commonly perturbed amongst South Asian populations - primarily glucose, fatty acid and lipoprotein metabolism and central adiposity. Using a 10-week dietary intervention study, 50 healthy South Asians will be randomised to receive either a DHRMA (reduced GI) supply of chapatti (bread), stone ground, high protein wheat flour and white basmati rice (high bran, unpolished) or commercially available (leading brand) versions chapatti wheat flour and basmati rice. Volunteers will be asked to complete a 75g oral glucose tolerance test at baseline and at 10-weeks follow-up, where blood metabolites and hormones, blood pressure and anthropometry will also be assessed in a standardised manner.</p> <p>Discussion</p> <p>It is anticipated that the information collected from this study help develop healthy diet options specific (but not exclusive) for South Asian ethnic communities.</p> <p>Trial registration</p> <p>Current Controlled Trials <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=ISRCTN02839188">ISRCTN02839188</a></p

    Integration of evidence across human and model organism studies: A meeting report.

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    The National Institute on Drug Abuse and Joint Institute for Biological Sciences at the Oak Ridge National Laboratory hosted a meeting attended by a diverse group of scientists with expertise in substance use disorders (SUDs), computational biology, and FAIR (Findability, Accessibility, Interoperability, and Reusability) data sharing. The meeting\u27s objective was to discuss and evaluate better strategies to integrate genetic, epigenetic, and \u27omics data across human and model organisms to achieve deeper mechanistic insight into SUDs. Specific topics were to (a) evaluate the current state of substance use genetics and genomics research and fundamental gaps, (b) identify opportunities and challenges of integration and sharing across species and data types, (c) identify current tools and resources for integration of genetic, epigenetic, and phenotypic data, (d) discuss steps and impediment related to data integration, and (e) outline future steps to support more effective collaboration-particularly between animal model research communities and human genetics and clinical research teams. This review summarizes key facets of this catalytic discussion with a focus on new opportunities and gaps in resources and knowledge on SUDs

    The sun is no fun without rain : Physical environments affect how we feel about yellow across 55 countries

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    Across cultures, people associate colours with emotions. Here, we test the hypothesis that one driver of this cross-modal correspondence is the physical environment we live in. We focus on a prime example – the association of yellow with joy, – which conceivably arises because yellow is reminiscent of life-sustaining sunshine and pleasant weather. If so, this association should be especially strong in countries where sunny weather is a rare occurrence. We analysed yellow-joy associations of 6625 participants from 55 countries to investigate how yellow-joy associations varied geographically, climatologically, and seasonally. We assessed the distance to the equator, sunshine, precipitation, and daytime hours. Consistent with our hypotheses, participants who live further away from the equator and in rainier countries are more likely to associate yellow with joy. We did not find associations with seasonal variations. Our findings support a role for the physical environment in shaping the affective meaning of colour.Peer reviewe
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