300 research outputs found

    Optimising the location of antenatal classes

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    Objectives: To combine micro simulation and location-allocation techniques to determine antenatal class locations which minimise the distance travelled from home by potential users. Design: Micro simulation modelling and location-allocation modeling. Setting: City of Leeds, U.K. Participants: Potential users of antenatal classes. Methods: An individual-level micro simulation model was built to estimate the number of births for small areas by combining data from the UK Census 2001 and the Health Survey for England 2006. Using this model as a proxy for service demand, we then used a location-allocation model to optimize locations. Findings: Different scenarios show the advantage of combining these methods to optimize (re)locating antenatal classes and therefore reduce inequalities in accessing services for pregnant women. Key Conclusions: Use of these techniques should lead to better use of resources by allowing planners to identifyoptimal locations of antenatal classes which minimise women’s travel. Implications for practice: These results are especially important for health-care planners tasked with the difficult issue of targeting scarce resources in a cost-efficient, but also effective or accessible, manner

    X-ray Observations of the Compact Source in CTA 1

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    The point source RX J0007.0+7302, at the center of supernova remnant CTA 1, was studied using the X-Ray Multi-mirror Mission. The X-ray spectrum of the source is consistent with a neutron star interpretation, and is well described by a power law with the addition of a soft thermal component that may correspond to emission from hot polar cap regions or to cooling emission from a light element atmosphere over the entire star. There is evidence of extended emission on small spatial scales which may correspond to structure in the underlying synchrotron nebula. No pulsations are observed. Extrapolation of the nonthermal spectrum of RX J0007.0+7302 to gamma-ray energies yields a flux consistent with that of EGRET source 3EG J0010+7309, supporting the proposition that there is a gamma-ray emitting pulsar at the center of CTA 1. Observations of the outer regions of CTA 1 with the Advanced Satellite for Cosmology and Astrophysics confirm earlier detections of thermal emission from the remnant and show that the synchrotron nebula extends to the outermost reaches of the SNR.Comment: 5 pages, including 4 postscript figs.LaTex. Accepted for publication by Ap

    Targeted Greybox Fuzzing with Static Lookahead Analysis

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    Automatic test generation typically aims to generate inputs that explore new paths in the program under test in order to find bugs. Existing work has, therefore, focused on guiding the exploration toward program parts that are more likely to contain bugs by using an offline static analysis. In this paper, we introduce a novel technique for targeted greybox fuzzing using an online static analysis that guides the fuzzer toward a set of target locations, for instance, located in recently modified parts of the program. This is achieved by first semantically analyzing each program path that is explored by an input in the fuzzer's test suite. The results of this analysis are then used to control the fuzzer's specialized power schedule, which determines how often to fuzz inputs from the test suite. We implemented our technique by extending a state-of-the-art, industrial fuzzer for Ethereum smart contracts and evaluate its effectiveness on 27 real-world benchmarks. Using an online analysis is particularly suitable for the domain of smart contracts since it does not require any code instrumentation---instrumentation to contracts changes their semantics. Our experiments show that targeted fuzzing significantly outperforms standard greybox fuzzing for reaching 83% of the challenging target locations (up to 14x of median speed-up)

    Clinimetrics of the Lanarkshire Oximetry Index for patients with leg ulcers: A systematic review and meta‐analysis

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    Ankle Brachial Pressure Index (ABPI) measurement has long been considered the gold standard of vascular assessment for people with lower limb ulceration. Despite this, only around 15% of patients in the United Kingdom who require an ABPI measurement undergo the assessment. The Lanarkshire Oximetry Index (LOI) is a cheaper and arguably more accessible approach to vascular assessment and was initially proposed as an alternative to the ABPI in 2000. No synthesis of evidence related to the LOI has been performed since its introduction into the literature. Primary studies were sought to determine the clinimetric properties of the LOI and its level of agreement with ABPI assessments. Systematic searches of MEDLINE, CINAHL, Cochrane Central Register of Controlled Trials, BNI, ProQuest Health and Medicine, Science Direct, Google Scholar and the British Library (online search) were conducted. Reference lists of identified studies were also reviewed to identify additional studies. Three primary studies met the inclusion criteria, reporting data from 307 patients and 584 limbs assessed using both the LOI and ABPI. All three studies reported fair to moderate kappa values for interrater reliability (κ = 0.290–0.747) and statistically significant positive correlation coefficients (r = 0.37, p < 0.001 in two studies) between the LOI and ABPI. The combined data from the three studies indicated a sensitivity of 52% (41.78–62.1, 95% confidence interval [CI]) and specificity of 96.08% (93.4–97.9, 95% CI) for the LOI using the ABPI as a reference. Additional data are required to indicate the safety of the LOI in practice. Data are also required to determine if the LOI is more acceptable to clinicians compared to the ABPI and whether there are any barriers/enablers to its implementation in practice. Given the relatively low specificity of the LOI, it may be beneficial to combine measurement of the LOI with a subjective clinical risk assessment tool to improve the sensitivity of this alternative approach to vascular assessment

    Deconvolution of the relaxations associated with local and segmental motions in poly(methacrylate)s containing dichlorinated benzyl moieties in the ester residue

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    9 pages, 15 figures, 1 scheme.The relaxation behavior of poly(2,3-dichlorobenzyl methacrylate) is studied by broadband dielectric spectroscopy in the frequency range of 10–1–109 Hz and temperature interval of 303–423 K. The isotherms representing the dielectric loss of the glassy polymer in the frequency domain present a single absorption, called B process. At temperatures close to Tg, the dynamical (alfa) relaxation already overlaps with the (beta) process, the degree of overlapping increasing with temperature. The deconvolution of the (alfa) and (beta) relaxations is facilitated using the retardation spectra calculated from the isotherms utilizing linear programming regularization parameter techniques. The temperature dependence of the (beta) relaxation presents a crossover associated with a change in activation energy of the local processes. The distance between the (alfa) and (beta) peaks, expressed as log(fmax;/fmax;) where fmax is the frequency at the peak maximum, follows Arrhenius behavior in the temperature range of 310–384 K. Above 384 K, the distance between the peaks remains nearly constant and, as a result, the (alfa) onset temperature exhibited for many polymers is not reached in this system. The fraction of relaxation carried out through the (alfa) process, without (beta) assistance, is larger than 60% in the temperature range of 310–384 K where the so-called Williams ansatz holds.This work was financially suported by the DGCYT and CAM through Grant Nos. MAT2002-04042-C02 and GR/ MAT/0723/2004. Two of the authors (L.G. and D.R.) thank the FONDECYT for partial financial support through Grant Nos. 21050956 and 1050962, respectively.Peer reviewe

    Identification and quantification of microplastics in wastewater using focal plane array-based reflectance micro-FT-IR imaging

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    Microplastics (<5 mm) have been documented in environmental samples on a global scale. While these pollutants may enter aquatic environments via wastewater treatment facilities, the abundance of microplastics in these matrices has not been investigated. Although efficient methods for the analysis of microplastics in sediment samples and marine organisms have been published, no methods have been developed for detecting these pollutants within organic-rich wastewater samples. In addition, there is no standardized method for analyzing microplastics isolated from environmental samples. In many cases, part of the identification protocol relies on visual selection before analysis, which is open to bias. In order to address this, a new method for the analysis of microplastics in wastewater was developed. A pretreatment step using 30% hydrogen peroxide (H2O2) was employed to remove biogenic material, and focal plane array (FPA)-based reflectance micro-Fourier-transform (FT-IR) imaging was shown to successfully image and identify different microplastic types (polyethylene, polypropylene, nylon-6, polyvinyl chloride, polystyrene). Microplastic-spiked wastewater samples were used to validate the methodology, resulting in a robust protocol which was nonselective and reproducible (the overall success identification rate was 98.33%). The use of FPA-based micro-FT-IR spectroscopy also provides a considerable reduction in analysis time compared with previous methods, since samples that could take several days to be mapped using a single-element detector can now be imaged in less than 9 h (circular filter with a diameter of 47 mm). This method for identifying and quantifying microplastics in wastewater is likely to provide an essential tool for further research into the pathways by which microplastics enter the environment.This work is funded by a NERC (Natural Environment Research Council) CASE studentship (NE/K007521/1) with contribution from industrial partner Fera Science Ltd., United Kingdom. The authors would like to thank Peter Vale, from Severn Trent Water Ltd, for providing access to and additionally Ashley Howkins (Brunel University London) for providing travel and assistance with the sampling of the Severn Trent wastewater treatment plant in Derbyshire, UK. We are grateful to Emma Bradley and Chris Sinclair for providing helpful suggestions for our research

    Novel ketone diet enhances physical and cognitive performance.

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    Ketone bodies are the most energy-efficient fuel and yield more ATP per mole of substrate than pyruvate and increase the free energy released from ATP hydrolysis. Elevation of circulating ketones via high-fat, low-carbohydrate diets has been used for the treatment of drug-refractory epilepsy and for neurodegenerative diseases, such as Parkinson's disease. Ketones may also be beneficial for muscle and brain in times of stress, such as endurance exercise. The challenge has been to raise circulating ketone levels by using a palatable diet without altering lipid levels. We found that blood ketone levels can be increased and cholesterol and triglycerides decreased by feeding rats a novel ketone ester diet: chow that is supplemented with (R)-3-hydroxybutyl (R)-3-hydroxybutyrate as 30% of calories. For 5 d, rats on the ketone diet ran 32% further on a treadmill than did control rats that ate an isocaloric diet that was supplemented with either corn starch or palm oil (P < 0.05). Ketone-fed rats completed an 8-arm radial maze test 38% faster than did those on the other diets, making more correct decisions before making a mistake (P < 0.05). Isolated, perfused hearts from rats that were fed the ketone diet had greater free energy available from ATP hydrolysis during increased work than did hearts from rats on the other diets as shown by using [31P]-NMR spectroscopy. The novel ketone diet, therefore, improved physical performance and cognitive function in rats, and its energy-sparing properties suggest that it may help to treat a range of human conditions with metabolic abnormalities.-Murray, A. J., Knight, N. S., Cole, M. A., Cochlin, L. E., Carter, E., Tchabanenko, K., Pichulik, T., Gulston, M. K., Atherton, H. J., Schroeder, M. A., Deacon, R. M. J., Kashiwaya, Y., King, M. T., Pawlosky, R., Rawlins, J. N. P., Tyler, D. J., Griffin, J. L., Robertson, J., Veech, R. L., Clarke, K. Novel ketone diet enhances physical and cognitive performance.A.J.M. thanks the Research Councils UK for supporting his Academic Fellowship. This work was supported by the Defense Advanced Research Projects Agency.This is the final version of the article. It first appeared from FASEB at https://doi.org/10.1096/fj.201600773R

    Determinants of variation in radical local treatment for men with high-risk localised or locally advanced prostate cancer in England.

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    BACKGROUND: Many factors are implicated in the potential 'under-treatment' of prostate cancer but little is known about the between-hospital variation. METHODS: The National Prostate Cancer Audit (NPCA) database was used to identify high-risk localised or locally advanced prostate cancer patients in England, between January 2014 and December 2017, and the treatments received. Hospital-level variation in radical local treatment was explored visually using funnel plots. The intra-class correlation coefficient (ICC) quantified the between-hospital variation in a random-intercept multivariable logistic regression model. RESULTS: 53,888 men, from 128 hospitals, were included and 35,034 (65.0%) received radical local treatment. The likelihood of receiving radical local treatment was increased in men who were younger (the strongest predictor), more affluent, those with fewer comorbidities, and in those with a non-Black ethnic background. There was more between-hospital variation (P < 0.001) for patients aged ≥80 years (ICC: 0.235) compared to patients aged 75-79 years (ICC: 0.070), 70-74 years (ICC: 0.041), and <70 years (ICC: 0.048). Comorbidity and socioeconomic deprivation did not influence the between-hospital variation. CONCLUSIONS: Radical local treatment of high-risk localised or locally advanced prostate cancer depended strongly on age and comorbidity, but also on socioeconomic deprivation and ethnicity, with the between-hospital variation being highest in older patients
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