1,514 research outputs found

    A Geant Study of the Scintillating Optical Fiber (SOFCAL) Cosmic Ray Detector

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    Recent energy measurements by balloon-borne passive emulsion chambers indicate that the flux ratios of protons to helium nuclei and of protons to all heavy nuclei decrease as the primary cosmic ray energy per nucleon increases above approx. 200 GeV/n, and suggest a "break" in the proton spectrum between 200 GeV and 5 TeV. However, these passive emulsion chambers are limited to a lower energy threshold of approx. 5 TeV/n, and cannot fully explore this energy regime. Because cosmic ray flux and composition details may be significant to acceleration models, a hybrid detector system called the Scintillating Optical Fiber Calorimeter (SOFCAL) has been designed and flown. SOFCAL incorporates both conventional passive emulsion chambers and an active calorimeter utilizing scintillating plastic fibers as detectors. These complementary types of detectors allow the balloon-borne SOFCAL experiment to measure the proton and helium spectra from approx. 400 GeV/n to approx. 20 TeV. The fundamental purpose of this study is to use the GEANT simulation package to model the hadronic and electromagnetic shower evolution of cosmic rays incident on the SOFCAL detector. This allows the interpretation of SOFCAL data in terms of charges and primary energies of cosmic rays, thus allowing the determinations of cosmic ray flux and composition as functions of primary energy

    Product and Packaging Innovation: Attitudes, Behaviours, and Strategies for Sustainable Packaging

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    The report presents findings of a large consumer survey on packaging, environmental issues and the media, conducted by Dr Martina Topic, Ben Mitchell and Olga Munroe. The survey was conducted on a representative sample of 1000 respondents, and forms a backbone of the future research and research outputs currently being prepared. This report has been distributed to the clients of the Retail Institute and will be presented at the Annual Retail Institute conference in September 2018

    Coral-like V<inf>2</inf>O<inf>5</inf> nanowhiskers as high-capacity cathode materials for lithium-ion batteries

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    Coral-like V2O5 nanowhiskers were prepared by a direct electrolytic synthesis method. The as-prepared V2O5 nanowhiskers are approximately 1 μm in length and 50-60 nm in width, which was confirmed by scanning electron microscopy and transmission electron microscopy analysis. When applied as cathode materials in lithium-ion batteries and combined with an ionic liquid electrolyte, the V2O5 nanowhiskers exhibited an initial capacity of 461 mAh g-1, which is a significant enhancement compared to commercial V2O5 powders. The high rate performance of the V2O5 nanowhiskers was further improved at an elevated working temperature of 50 °C. The V2O5 nanowhiskers demonstrated a high specific capacity and an excellent high-rate performance at elevated temperatures. © 2013 The Royal Society of Chemistry

    Meta-Analysis of Dilated Cardiomyopathy Using Cardiac RNA-Seq Transcriptomic Datasets.

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    Dilated cardiomyopathy (DCM) is one of the most common causes of heart failure. Several studies have used RNA-sequencing (RNA-seq) to profile differentially expressed genes (DEGs) associated with DCM. In this study, we aimed to profile gene expression signatures and identify novel genes associated with DCM through a quantitative meta-analysis of three publicly available RNA-seq studies using human left ventricle tissues from 41 DCM cases and 21 control samples. Our meta-analysis identified 789 DEGs including 581 downregulated and 208 upregulated genes. Several DCM-related genes previously reported, including MYH6, CKM, NKX2-5 and ATP2A2, were among the top 50 DEGs. Our meta-analysis also identified 39 new DEGs that were not detected using those individual RNA-seq datasets. Some of those genes, including PTH1R, ADAM15 and S100A4, confirmed previous reports of associations with cardiovascular functions. Using DEGs from this meta-analysis, the Ingenuity Pathway Analysis (IPA) identified five activated toxicity pathways, including failure of heart as the most significant pathway. Among the upstream regulators, SMARCA4 was downregulated and prioritized by IPA as the top affected upstream regulator for several DCM-related genes. To our knowledge, this study is the first to perform a transcriptomic meta-analysis for clinical DCM using RNA-seq datasets. Overall, our meta-analysis successfully identified a core set of genes associated with DCM

    Predicting deleterious nsSNPs: an analysis of sequence and structural attributes

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    BACKGROUND: There has been an explosion in the number of single nucleotide polymorphisms (SNPs) within public databases. In this study we focused on non-synonymous protein coding single nucleotide polymorphisms (nsSNPs), some associated with disease and others which are thought to be neutral. We describe the distribution of both types of nsSNPs using structural and sequence based features and assess the relative value of these attributes as predictors of function using machine learning methods. We also address the common problem of balance within machine learning methods and show the effect of imbalance on nsSNP function prediction. We show that nsSNP function prediction can be significantly improved by 100% undersampling of the majority class. The learnt rules were then applied to make predictions of function on all nsSNPs within Ensembl. RESULTS: The measure of prediction success is greatly affected by the level of imbalance in the training dataset. We found the balanced dataset that included all attributes produced the best prediction. The performance as measured by the Matthews correlation coefficient (MCC) varied between 0.49 and 0.25 depending on the imbalance. As previously observed, the degree of sequence conservation at the nsSNP position is the single most useful attribute. In addition to conservation, structural predictions made using a balanced dataset can be of value. CONCLUSION: The predictions for all nsSNPs within Ensembl, based on a balanced dataset using all attributes, are available as a DAS annotation. Instructions for adding the track to Ensembl are a

    SEL1L deficiency impairs growth and differentiation of pancreatic epithelial cells

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    <p>Abstract</p> <p>Background</p> <p>The vertebrate pancreas contains islet, acinar and ductal cells. These cells derive from a transient pool of multipotent pancreatic progenitors during embryonic development. Insight into the genetic determinants regulating pancreatic organogenesis will help the development of cell-based therapies for the treatment of diabetes mellitus. <it>Suppressor enhancer lin12/Notch 1 like (Sel1l</it>) encodes a cytoplasmic protein that is highly expressed in the developing mouse pancreas. However, the morphological and molecular events regulated by <it>Sel1l </it>remain elusive.</p> <p>Results</p> <p>We have characterized the pancreatic phenotype of mice carrying a gene trap mutation in <it>Sel1l</it>. We show that <it>Sel1l </it>expression in the developing pancreas coincides with differentiation of the endocrine and exocrine lineages. Mice homozygous for the gene trap mutation die prenatally and display an impaired pancreatic epithelial morphology and cell differentiation. The pancreatic epithelial cells of <it>Sel1l </it>mutant embryos are confined to the progenitor cell state throughout the secondary transition. Pharmacological inhibition of Notch signaling partially rescues the pancreatic phenotype of <it>Sel1l </it>mutant embryos.</p> <p>Conclusions</p> <p>Together, these data suggest that <it>Sel1l </it>is essential for the growth and differentiation of endoderm-derived pancreatic epithelial cells during mouse embryonic development.</p

    Operational Theory of Homodyne Detection

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    We discuss a balanced homodyne detection scheme with imperfect detectors in the framework of the operational approach to quantum measurement. We show that a realistic homodyne measurement is described by a family of operational observables that depends on the experimental setup, rather than a single field quadrature operator. We find an explicit form of this family, which fully characterizes the experimental device and is independent of a specific state of the measured system. We also derive operational homodyne observables for the setup with a random phase, which has been recently applied in an ultrafast measurement of the photon statistics of a pulsed diode laser. The operational formulation directly gives the relation between the detected noise and the intrinsic quantum fluctuations of the measured field. We demonstrate this on two examples: the operational uncertainty relation for the field quadratures, and the homodyne detection of suppressed fluctuations in photon statistics.Comment: 7 pages, REVTe

    Doping Effect of Nano-Diamond on Superconductivity and Flux Pinning in MgB2

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    Doping effect of diamond nanoparticles on the superconducting properties of MgB2 bulk material has been studied. It is found that the superconducting transition temperature Tc of MgB2 is suppressed by the diamond-doping, however, the irreversibility field Hirr and the critical current density Jc are systematically enhanced. Microstructural analysis shows that the diamond-doped MgB2 superconductor consists of tightly-packed MgB2 nano-grains (~50-100 nm) with highly-dispersed and uniformly-distributed diamond nanoparticles (~10-20 nm) inside the grains. High density of dislocations and diamond nanoparticles may take the responsibility for the enhanced flux pinning in the diamond-doped MgB2.Comment: 16 pages, 6 figure

    Women with diabetes are at increased relative risk of heart failure compared to men: Insights from UK Biobank

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    Aims: To investigate the effect of diabetes on mortality and incident heart failure (HF) according to sex, in the low risk population of UK Biobank. To evaluate potential contributing factors for any differences seen in HF end-point. Methods: The entire UK Biobank study population were included. Participants that withdrew consent or were diagnosed with diabetes after enrolment were excluded from the study. Univariate and multivariate cox regression models were used to assess endpoints of mortality and incident HF, with median follow-up periods of 9 years and 8 years respectively. Results: A total of 493,167 participants were included, hereof 22,685 with diabetes (4.6%). Two thousand four hundred fifty four died and 1,223 were diagnosed or admitted with HF during the follow up periods of 9 and 8 years respectively. Overall, the mortality and HF risk were almost doubled in those with diabetes compared to those without diabetes (hazard ratio (HR) of 1.9 for both mortality and heart failure) in the UK Biobank population. Women with diabetes (both types) experience a 22% increased risk of HF compared to men (HR of 2.2 (95% CI: 1.9-2.5) vs. 1.8 (1.7-2.0) respectively). Women with type 1 diabetes (T1DM) were associated with 88% increased risk of HF compared to men (HR 4.7 (3.6-6.2) vs. 2.5 (2.0-3.0) respectively), while the risk of HF for type 2 diabetes (T2DM) was 17% higher in women compared to men (2.0 (1.7-2.3) vs. 1.7 (1.6-1.9) respectively). The increased risk of HF in women was independent of confounding factors. The findings were similar in a model with all-cause mortality as a competing risk. This interaction between sex, diabetes and outcome of HF is much more prominent for T1DM (p = 0.0001) than T2DM (p = 0.1). Conclusion: Women with diabetes, particularly those with T1DM, experience a greater increase in risk of heart failure compared to men with diabetes, which cannot be explained by the increased prevalence of cardiac risk factors in this cohort

    Premature atrial and ventricular contractions detected on wearable-format electrocardiograms and prediction of cardiovascular events

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    AIMS: Wearable devices are transforming the electrocardiogram (ECG) into a ubiquitous medical test. This study assesses the association between premature ventricular and atrial contractions (PVCs and PACs) detected on wearable-format ECGs (15 s single lead) and cardiovascular outcomes in individuals without cardiovascular disease (CVD). METHODS AND RESULTS: Premature atrial contractions and PVCs were identified in 15 s single-lead ECGs from N = 54 016 UK Biobank participants (median age, interquartile range, age 58, 50-63 years, 54% female). Cox regression models adjusted for traditional risk factors were used to determine associations with atrial fibrillation (AF), heart failure (HF), myocardial infarction (MI), stroke, life-threatening ventricular arrhythmias (LTVAs), and mortality over a period of 11.5 (11.4-11.7) years. The strongest associations were found between PVCs (prevalence 2.2%) and HF (hazard ratio, HR, 95% confidence interval = 2.09, 1.58-2.78) and between PACs (prevalence 1.9%) and AF (HR = 2.52, 2.11-3.01), with shorter prematurity further increasing risk. Premature ventricular contractions and PACs were also associated with LTVA (P < 0.05). Associations with MI, stroke, and mortality were significant only in unadjusted models. In a separate UK Biobank sub-study sample [UKB-2, N = 29,324, age 64, 58-60 years, 54% female, follow-up 3.5 (2.6-4.8) years] used for independent validation, after adjusting for risk factors, PACs were associated with AF (HR = 1.80, 1.12-2.89) and PVCs with HF (HR = 2.32, 1.28-4.22). CONCLUSION: In middle-aged individuals without CVD, premature contractions identified in 15 s single-lead ECGs are strongly associated with an increased risk of AF and HF. These data warrant further investigation to assess the role of wearable ECGs for early cardiovascular risk stratification
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