2,030 research outputs found

    Libraries need standards

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    The article discusses the need for standards in the library and information science profession, such as the use of the Dewey Decimal System of classification or the Dublin Core metadata scheme which facilitate information organization and library orientation. The most fundamental area in which standards are used is in the description and identification of objects. The author argues that the increasingly high number of electronic and Web-based information resources necessitates a universal set of standards for such material

    Modelling Gaia CCD pixels with Silvaco 3D engineering software

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    Gaia will only achieve its unprecedented measurement accuracy requirements with detailed calibration and correction for radiation damage. We present our Silvaco 3D engineering software model of the Gaia CCD pixel and two of its applications for Gaia: (1) physically interpreting supplementary buried channel (SBC) capacity measurements (pocket-pumping and first pixel response) in terms of e2v manufacturing doping alignment tolerances; and (2) deriving electron densities within a charge packet as a function of the number of constituent electrons and 3D position within the charge packet as input to microscopic models being developed to simulate radiation damage.Comment: 4 pages, 3 figures, contributed poster, appearing in proceedings of the ELSA conference: Gaia, at the frontiers of astrometry, 7-11 June 2010, S\`evres, Pari

    Tadalafil in patients with chronic obstructive pulmonary disease:a randomised, double-blind, parallel-group, placebo-controlled trial

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    SummaryBackgroundPhosphodiesterase-5 (PDE5) inhibitors improve exercise capacity and quality of life in patients with idiopathic pulmonary arterial hypertension. However, whether such beneficial effects take place in selected populations with chronic obstructive pulmonary disease (COPD) remains uncertain. We aimed to assess the effects of tadalafil—a PDE5 inhibitor—on exercise capacity and quality of life in patients with COPD and mild pulmonary hypertension.MethodsWe did a randomised, double-blind, parallel-group, placebo-controlled trial at three centres in Scotland, UK, between Sept 1, 2010, and Sept 1, 2012. Patients with moderate to severe COPD were randomly assigned (1:1), via centralised randomisation with a computer-generated sequence and block sizes of four, to receive daily tadalafil 10 mg or placebo for 12 weeks. Patients, study investigators, outcome assessors, and those administering drugs were masked to group allocation. The primary endpoint was the mean placebo-corrected difference between the baseline and final 6 min walk distance after 12 weeks. We measured change in quality of life at baseline, 8 weeks, and 12 weeks, with standardised questionnaires. Analysis was per protocol and by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01197469.Findings120 patients were randomly assigned to receive tadalafil (n=60) or placebo (n=60), of whom 56 (93%) versus 57 (95%) completed the study. At 12 weeks the difference in 6 min walking distance between the tadalafil and placebo groups was 0·5 m (95% CI −11·6 to 12·5; p=0·937). We recorded no statistically significant changes in quality of life (between-group difference on the St George's Respiratory Questionnaire −2·64 [95% CI −6·43 to 1·15]; Research and Development version 1 short-form-36 4·08 [–1·35 to 9·52]; Minnesota Living with Heart Failure questionnaire −2·31 [–7·06 to 2·45]). 19 (32%) of 60 patients in the treatment group had dyspepsia; the severity of dyspepsia ranged from mild to severe, with four (21%) of 19 patients needing a proton-pump inhibitor. Five (8%) of 60 participants had dyspepsia in the placebo group. Headache was noted in 17 (28%) patients in the treatment group versus 5 (8%) in the placebo group, but was mild in all patients. Two (3%) patients in the treatment group had facial flushing, which resulted in one withdrawal. Other withdrawals within the tadalafil group happened after a transient ischaemic attack and two deaths (ruptured abdominal aortic aneurysm and pneumonia).InterpretationTadalafil does not improve exercise capacity or quality of life despite exerting pulmonary vasodilation.FundingChief Scientist Office for Scotland

    Magneto-optical study of thermally annealed InAs-InGaAs-GaAs self-assembled quantum dots

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    We report a magneto-optical study of InAs-InGaAs-GaAs self-assembled quantum dots (QDs) subjected to post-growth thermal annealing at different temperatures. At low temperatures annealing strongly affects the bimodal distribution of QDs; at higher temperatures a strong blueshift of the emission occurs. Magnetophotoluminescence reveals that the annealing increases the QD size, with a larger effect occurring along the growth axis, and decreases the carrier effective masses. The main contribution to the blueshift is deduced to be an increase in the average Ga composition of the QDs. The inadvertent annealing which occurs during the growth of the upper AlGaAs cladding layer in laser structures is also studied

    Core-level photoemission spectroscopy of nitrogen bonding in GaNxAs1–x alloys

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    The nitrogen bonding configurations in GaNxAs1–x alloys grown by molecular beam epitaxy with 0.07=0.03, the nitrogen is found to exist in a single bonding configuration – the Ga–N bond; no interstitial nitrogen complexes are present. The amount of nitrogen in the alloys is estimated from the XPS using the N 1s photoelectron and Ga LMM Auger lines and is found to be in agreement with the composition determined by x-ray diffraction

    Influenza vaccination for NHS staff: attitudes and uptake.

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    OBJECTIVES: Annual vaccination against influenza (flu) is recommended for all UK National Health Service (NHS) staff to help reduce the risk of contracting the virus and transmitting it to patients. However, despite flu campaigns and vaccination promotion, uptake remains low. The aim of this study was to investigate staff attitudes to flu vaccination to see how this may influence their decision to be vaccinated. METHODS: An online survey was sent to staff members across 6 NHS trusts, asking if staff had been vaccinated in the preceding flu season (2013-2014); the survey included questions about beliefs and attitudes to the vaccination, scored on a 5-point Likert scale. RESULTS: 3059 NHS staff members responded to the survey (86% in the 26-59 age group, 77% female and 84% hospital based). 68% of respondents reported being vaccinated in the preceding year. Using a stepwise regression model, the survey response retained as a positive predictor of having been vaccinated was people working in healthcare should have the flu vaccination every year (p<0.001), and the responses retained as negative predictors were the flu vaccination will make me unwell (p<0.001) and the flu vaccination was too much trouble for me (p<0.001). Analysis by staff group showed a significant difference in the response to the flu vaccination will make me unwell between groups (p=0.01), with doctors having a greater tendency to disagree with this statement than other staff members. CONCLUSIONS: These results suggest that addressing NHS staff beliefs around the need for vaccination, while ensuring that practical barriers to having the vaccination are removed, may help to increase uptake. An emphasis on alleviating the concerns of particular staff groups regarding adverse effects of the vaccine may also be of benefit in improving uptake, to protect patients as well as staff

    Phenotypic change and induction of cytokeratin expression during in vitro culture of corneal stromal cells

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    Purpose: Cells of the corneal epithelium and stroma can be distinguished in vivo by different intermediate filaments, cytokeratins for corneal epithelial cells (CEC) and vimentin for keratocytes. Isolated and cultured keratocytes change phenotype, losing expression of keratocyte markers and gaining markers associated with mesenchymal stromal cells (MSC). This study investigates this change in phenotype in relation to intermediate filament expression in cultured corneal stromal cells (CSC) compared to CEC. Methods: Expression of epithelial markers (CK3, CK12, CK19, pan cytokeratin, E-cadherin), keratocyte markers (CD34, vimentin) and MSC markers (CD73, CD90 and CD105) were compared in CEC and CSC by immunocytochemistry and RT-qPCR. Expression was evaluated at different stages of CSC culture and compared to another stromal cell type, extracted from Wharton’s jelly (WJ-MSC). Results: In vivo keratocytes did not express cytokeratins. However, cultured CSC expressed epithelial-associated CK3, CK12 and CK19 but other cytokeratins. Expression of cytokeratins increased as CSC were passaged and decreased as CSC were induced to become quiescent. Comparatively, WJ-MSC, expressed lower levels of CK3, CK12 and CK19, but also stained for pan cytokeratin and expressed KRT5. Conclusions: Cultured CSC undergo phenotypic change during culture, expressing specific cytokeratin filaments normally associated with CEC. Cytokeratin expression begins as cells are cultured on plastic and increases with passage. This discovery may influence the way that differences are discerned between cultured CEC and CSC. Investigators need to be aware that the expression of cytokeratins does not necessarily represent epithelial contamination, and that CEC and CSC may be more related than previously recognised

    The University as a site for transformation around sustainability

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    YesUniversities are increasingly being seen as key sites for transformation around sustainability. However, much of the literature in this area uses the terms transformation and transformative learning rather uncritically. Moreover, there is little extant research which has investigated the links between transformative learning theories and Education for Sustainability (EfS). This paper reports on a research project which explored academic and student perceptions of the opportunities for transformation around sustainability in two UK universities. The findings suggest that, despite shared understanding about the nature of pedagogic approaches that promote deep learning, academics are wary about promoting transformation beyond the professional sphere and students are more likely to have transformative experiences outside the formal curriculum. There are indications that although universities have significant potential as sites for transformation around sustainability, at present, this is not being achieved

    Social isolation, loneliness and physical performance in older-adults: fixed effects analyses of a cohort study

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    Isolation and loneliness are related to various aspects of health. Physical performance is a central component of health. However, its relationship with isolation and loneliness is not well understood. We therefore assessed the relationship between loneliness, different aspects of social isolation, and physical performance over time. 8,780 participants from the English Longitudinal Study of Ageing, assessed three times over 8 years of follow-up, were included. Measures included physical performance (Short Physical Performance Battery), loneliness (modified UCLA Loneliness Scale), and isolation considered in three ways (domestic isolation, social disengagement, low social contact). Fixed effects regression models were used to estimate the relationship between changes in these parameters. Missing data were imputed to account for variable response and ensure a representative sample. Loneliness, domestic isolation and social disengagement were longitudinally associated with poorer physical performance when accounting for both time-invariant and time-variant confounders (loneliness: coef = - 0.06, 95% CI - 0.09 to - 0.02; domestic isolation: coef = - 0.32, 95% CI - 0.46 to - 0.19; social disengagement: coef = - 0.10, 95% CI - 0.12 to - 0.07). Low social contact was not associated with physical performance. These findings suggest social participation and subjectively meaningful interpersonal interactions are related to physical performance, and highlight additional considerations regarding social distancing related to COVID-19 control measures
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