591 research outputs found

    Equilibrium crystal shapes in the Potts model

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    The three-dimensional qq-state Potts model, forced into coexistence by fixing the density of one state, is studied for q=2q=2, 3, 4, and 6. As a function of temperature and number of states, we studied the resulting equilibrium droplet shapes. A theoretical discussion is given of the interface properties at large values of qq. We found a roughening transition for each of the numbers of states we studied, at temperatures that decrease with increasing qq, but increase when measured as a fraction of the melting temperature. We also found equilibrium shapes closely approaching a sphere near the melting point, even though the three-dimensional Potts model with three or more states does not have a phase transition with a diverging length scale at the melting point.Comment: 6 pages, 3 figures, submitted to PR

    Rapid Colorimetric Detection of Pseudomonas aeruginosa in Clinical Isolates Using a Magnetic Nanoparticle Biosensor

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    A rapid, sensitive, and specific colorimetric biosensor based on the use of magnetic nanoparticles (MNPs) was designed for the detection of Pseudomonas aeruginosa in clinical samples. The biosensing platform was based on the measurement of P. aeruginosa proteolytic activity using a specific protease substrate. At the N-terminus, this substrate was covalently bound to MNPs and was linked to a gold sensor surface via cystine at the C-terminus of the substrates. The golden sensor appears black to naked eyes because of the coverage of the MNPs. However, upon proteolysis, the cleaved peptide-MNP moieties will be attracted by an external magnet, revealing the golden color of the sensor surface, which can be observed by the naked eye. In vitro, the biosensor was able to detect specifically and quantitatively the presence of P. aeruginosa with a detection limit of 102 cfu/mL in less than 1 min. The colorimetric biosensor was used to test its ability to detect in situ P. aeruginosa in clinical isolates from patients. This biochip is anticipated to be useful as a rapid point-of-care device for the diagnosis of P. aeruginosa-related infections

    Outcome related to impact on daily living: preliminary validation of the ORIDL instrument

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    <p>Abstract</p> <p>Background</p> <p>The challenge of finding practical, patient-rated outcome measures is a key issue in the evaluation of health care systems and interventions. The ORIDL (Outcome in Relation to Impact on Daily Living) instrument (formerly referred to as the Glasgow Homoeopathic Hospital Outcomes Scale or GHHOS) has been developed to measure patient's views of the outcome of their care by asking about change, and relating this to impact on daily life. The aim of the present paper is to describe the background and potential uses of the ORIDL, and to report on its preliminary validation in a series of three studies in secondary and primary care.</p> <p>Methods</p> <p>In the first study, 105 patients attending the Glasgow Homoeopathic Hospital (GHH) were followed-up at 12 months and changes in health status were measured by the EuroQol (EQOL) and the ORIDL. In the second study, 187 new patients at the GHH were followed-up at 3, 12, and 33 months, using the ORIDL, the Short Form 12 (SF-12), and the Measure Yourself Medical Outcome Profile (MYMOP). In study three, 323 patients in primary care were followed for 1 month post-consultation using the ORIDL and MYMOP. In all 3 studies the Patient Enablement Instrument (PEI) was also used as an outcome measure.</p> <p>Results</p> <p>Study 1 showed substantial improvements in main complaint and well-being over 12 months using the ORIDL, with two-thirds of patients reporting improvements in daily living. These improvements were not significantly correlated with changes in serial measures of the EQOL between baseline and 12 months, but were correlated with the EQOL transitions measure. Study 2 showed step-wise improvements in ORIDL scores between 3 and 33 months, which were only weakly associated with similar changes in SF-12 scores. However, MYMOP change scores correlated well with ORIDL scores at all time points. Study 3 showed similar high correlations between ORIDL scores and MYMOP scores. In all 3 studies, ORIDL scores were also significantly correlated with PEI-outcome scores.</p> <p>Conclusion</p> <p>There is significant agreement between patient outcomes assessed by the ORIDL and the EQOL transition scale, the MYMOP, and the PEI-outcome instrument, suggesting that the ORIDL may be a valid and sensitive tool for measuring change in relation to impact on life.</p

    Sources of pro-cyclicality in east Asian financial systems

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    Procyclicality is a normal feature of economic systems, but financial sector weaknesses can exacerbate it sufficiently to pose a threat to macroeconomic and financial stability. These include shortcomings in bank risk management and governance, in supervision and in terms of dependence on volatile sources of funds. The paper tests econometrically for the importance of such features leading to pro-cyclicality in the financial systems of 11 East Asian countries. This analysis makes it possible to identify specific policy measures for East Asian countries that could limit the extent to which financial systems exacerbate pro-cyclicality

    Is the MENA banking sector competitive?

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    The purpose of this paper is to investigate the competitive conditions and revenue drivers of commercial banks in the MENA region in the context of Panzar–Rosse model. It is the first study of its kind that examines a large sample of MENA banks for an extensive period (1999–2012) during an era of political and economic unrest and transformation that includes the the global financial crisis (2007–2009). Panel data analysis using fixed effects was employed in order to examine whether the competitive conditions in MENA banks is explained by monopoly, monopolistic competition or perfect competition. Findings show that MENA banks operate under monopolistic competition, and bank-specific variables show a positive impact on revenue. These findings indicate that policymakers should relax capital adequacy requirements to guarantee the stability of the financial system. They also raise a concern that commercial banks in the MENA economies tend to concentrate on traditional lending activities, where their competitive position may be eroded in the long run by the decreasing state role of Islamic banks and by mergers that are not empirically justified for MENA banks during this period
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