798 research outputs found

    Comparison of Compression Schemes for CLARA

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    CLARA (Compact Linear Advanced Research Accelerator)at Daresbury Laboratory is proposed to be the UK's national FEL test facility. The accelerator will be a ~250 MeV electron linac capable of producing short, high brightness electron bunches. The machine comprises a 2.5cell RF photocathode gun, one 2 m and three 5 m normal conducting S-band (2998MHz) accelerating structures and a variable magnetic compression chicane. CLARA will be used as a test bed for novel FEL configurations. We present a comparison of acceleration and compression schemes for the candidate machine layout.Comment: 3 pages, 5 figures, IPAC 201

    Heavy cannabis use is associated with low bone mineral density and an increased risk of fractures

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    Purpose: To investigate possible associations between recreational cannabis use and bone health in humans.  Methods: Cross-sectional study of individuals recruited from primary care in the UK between 2011 and 2014. Cases were regular smokers of cannabis divided into moderate (n=56) and heavy user (n=144) subgroups depending on whether they reported fewer or more than 5000 cannabis smoking episodes during their lifetime. Controls comprised 114 cigarette smokers.  Results: Heavy cannabis users had lower total hip bone mineral density (mean ± SD Z-score: -0.20±0.9 vs. +0.2±0.9, p<0.0005), lower spine bone mineral density (-0.5±1.2 vs. 0.0±1.2, p<0.0005) and lower BMI (26.5±6.0 vs 29.0±7.0, p=0.01) than controls. Fracture rate was also increased in heavy users (rate ratio=2.17, 95% confidence interval 1.59 to 2.95; p<0.001). When compared with controls, CTX serum concentrations were raised in heavy cannabis users (0.3±0.1 vs. 0.2±0.1 pg/ml, p=0.045) as were P1NP concentrations (47.1±19.2 vs. 41.2±17.8 pg/ml, p=0.01). Serum 25(OH)D concentrations were reduced in heavy users compared with controls (25.3±16.8 vs. 36.9±26.7 nmol/l, p=0.002). Multiple regression analysis revealed that heavy cannabis use was an independent predictor of spine bone mineral density accounting for 5.4% of the variance (p=0.035) and total hip bone mineral density accounting for 5.8% of the variance (p=0.001) but mediation analysis suggested that the effect on spine bone mineral density was indirect and mediated through low BMI.  Conclusion: Heavy cannabis use is associated with low bone mineral density, low BMI, high bone turnover and an increased risk of fracture. Heavy cannabis use negatively impacts on bone health both directly and indirectly through an effect on BMI

    Post hoc analyses of surrogate markers of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis in patients with type 2 diabetes in a digitally supported continuous care intervention: An open-label, non-randomised controlled study

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    OBJECTIVE: One year of comprehensive continuous care intervention (CCI) through nutritional ketosis improves glycosylated haemoglobin(HbA1c), body weight and liver enzymes among patients with type 2 diabetes (T2D). Here, we report the effect of the CCI on surrogate scores of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis. METHODS: This was a non-randomised longitudinal study, including adults with T2D who were self-enrolled to the CCI (n=262) or to receive usual care (UC, n=87) during 1 year. An NAFLD liver fat score (N-LFS) >-0.640 defined the presence of fatty liver. An NAFLD fibrosis score (NFS) of >0.675 identified subjects with advanced fibrosis. Changes in N-LFS and NFS at 1 year were the main endpoints. RESULTS: At baseline, NAFLD was present in 95% of patients in the CCI and 90% of patients in the UC. At 1 year, weight loss of ≥5% was achieved in 79% of patients in the CCI versus 19% of patients in UC (p<0.001). N-LFS mean score was reduced in the CCI group (-1.95±0.22, p<0.001), whereas it was not changed in the UC (0.47±0.41, p=0.26) (CCI vs UC, p<0.001). NFS was reduced in the CCI group (-0.65±0.06, p<0.001) compared with UC (0.26±0.11, p=0.02) (p<0.001 between two groups). In the CCI group, the percentage of individuals with a low probability of advanced fibrosis increased from 18% at baseline to 33% at 1 year (p<0.001). CONCLUSIONS: One year of a digitally supported CCI significantly improved surrogates of NAFLD and advanced fibrosis in patients with T2D

    Classification of non-indigenous species based on their impacts: Considerations for application in marine management

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    Assessment of the ecological and economic/societal impacts of the introduction of non-indigenous species (NIS) is one of the primary focus areas of bioinvasion science in terrestrial and aquatic environments, and is considered essential to management. A classification system of NIS, based on the magnitude of their environmental impacts, was recently proposed to assist management. Here, we consider the potential application of this classification scheme to the marine environment, and offer a complementary framework focussing on value sets in order to explicitly address marine management concerns. Since existing data on marine NIS impacts are scarce and successful marine removals are rare, we propose that management of marine NIS adopt a precautionary approach, which not only would emphasise preventing new incursions through pre-border and at-border controls but also should influence the categorisation of impacts. The study of marine invasion impacts requires urgent attention and significant investment, since we lack the luxury of waiting for the knowledge base to be acquired before the window of opportunity closes for feasible management

    The enlargement of the Suez Canal and introduction of non-indigenous species to the Mediterranean Sea

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    The Suez Canal is one of the most important waterways in the world – during the last year 17,148 ships passed through the Canal – reducing emissions, saving time, and operating costs to shippers. The rapid increase in ship size from the “Post-Suezmax” (> 12,000 TEU) to the latest container vessels (> 19,000 TEU) now requires enlargements of port facilities and canals. A project of this magnitude, and with potentially negative environmental outcomes, requires a transparent and scientifically sound “Environmental Impact Assessment” (EIA). An explicit obligation on Parties to the Convention on Biological Diversity (https://www.cbd.int/doc/ legal/cbd-en.pdf) was made to consider transboundary impacts on biodiversity, particularly those associated with invasive non-indigenous species

    The effectiveness of the McKenzie method in addition to first-line care for acute low back pain: a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Low back pain is a highly prevalent and disabling condition worldwide. Clinical guidelines for the management of patients with acute low back pain recommend first-line treatment consisting of advice, reassurance and simple analgesics. Exercise is also commonly prescribed to these patients. The primary aim of this study was to evaluate the short-term effect of adding the McKenzie method to the first-line care of patients with acute low back pain.</p> <p>Methods</p> <p>A multi-centre randomized controlled trial with a 3-month follow-up was conducted between September 2005 and June 2008. Patients seeking care for acute non-specific low back pain from primary care medical practices were screened. Eligible participants were assigned to receive a treatment programme based on the McKenzie method and first-line care (advice, reassurance and time-contingent acetaminophen) or first-line care alone, for 3 weeks. Primary outcome measures included pain (0-10 Numeric Rating Scale) over the first seven days, pain at 1 week, pain at 3 weeks and global perceived effect (-5 to 5 scale) at 3 weeks. Treatment effects were estimated using linear mixed models.</p> <p>Results</p> <p>One hundred and forty-eight participants were randomized into study groups, of whom 138 (93%) completed the last follow-up. The addition of the McKenzie method to first-line care produced statistically significant but small reductions in pain when compared to first-line care alone: mean of -0.4 points (95% confidence interval, -0.8 to -0.1) at 1 week, -0.7 points (95% confidence interval, -1.2 to -0.1) at 3 weeks, and -0.3 points (95% confidence interval, -0.5 to -0.0) over the first 7 days. Patients receiving the McKenzie method did not show additional effects on global perceived effect, disability, function or on the risk of persistent symptoms. These patients sought less additional health care than those receiving only first-line care (<it>P </it>= 0.002).</p> <p>Conclusions</p> <p>When added to the currently recommended first-line care of acute low back pain, a treatment programme based on the McKenzie method does not produce appreciable additional short-term improvements in pain, disability, function or global perceived effect. However, the McKenzie method seems to reduce health utilization although it does not reduce patient's risk of developing persistent symptoms.</p> <p>Trial Registration</p> <p>Australian New Zealand Clinical Trials Registry: ACTRN12605000032651</p
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