129 research outputs found

    A first look at quasi-Monte Carlo for lattice field theory problems

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    In this project we initiate an investigation of the applicability of Quasi-Monte Carlo methods to lattice field theories in order to improve the asymptotic error behavior of observables for such theories. In most cases the error of an observable calculated by averaging over random observations generated from an ordinary Monte Carlo simulation behaves like N−1/2, where N is the number of observations. By means of Quasi-Monte Carlo methods it is possible to improve this behavior for certain problems to up to N−1. We adapted and applied this approach to simple systems like the quantum harmonic and anharmonic oscillator and verified an improved error scaling.Peer Reviewe

    Does in-shoe pressure analysis to assess and modify medical grade footwear improve patient adherence and understanding? A mixed methods study

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    Background: Medical grade footwear (MGF) with demonstrated plantar-pressure reducing effect is recommended to reduce the risk of diabetes-related foot ulceration (DFU). Efficacy of MGF relies on high adherence (≥ 80%). In-shoe pressure analysis (IPA) is used to assess and modify MGF, however, there is limited evidence for the impact on patient adherence and understanding of MGF. The primary aim of this study was to determine if self-reported adherence to MGF usage in patients with previous DFU improved following IPA compared to adherence measured prior. The secondary aim was to determine if patient understanding of MGF improved following in-shoe pressure analysis. Methods: Patients with previous DFU fitted with MGF in the last 12 months were recruited. The first three participants were included in a pilot study to test procedures and questionnaires. MGF was assessed and modified at Week 0 based on findings from IPA using the Pedar system (Novel). Patients completed two questionnaires, one assessing patient adherence to MGF at Week 0 and Week 4, the other assessing patient understanding of MGF before and after IPA at week 0. Patient understanding was measured using a 5-point Likert scale (strongly disagree 1 to strongly agree 5). Patient experience was assessed via a telephone questionnaire administered between Weeks 0–1. Results: Fifteen participants were recruited, and all completed the study. Adherence of ≥ 80% to MGF usage inside the home was 13.3% (n = 2) pre-IPA and 20.0% (n = 3) at Week 4. Outside the home, ≥ 80% adherence to MGF was 53.3% (n = 8) pre-IPA, and 80.0% (n = 12) at Week 4. Change in scores for understanding of MGF were small, however, all participants reported that undergoing the intervention was worthwhile and beneficial. Conclusions: Self-reported adherence inside the home demonstrated minimal improvement after 4 weeks, however, adherence of ≥ 80% outside the home increased by 27%, with 80% of all participants reporting high adherence at Week 4. Participants rated their learnings from the experience of IPA as beneficial

    The cost-utility of haemodiafiltration versus haemodialysis in the Convective Transport Study

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    Background. Despite the growing interest in haemodiafiltration (HDF), there is no information on the costs and cost-utility of this dialysis modality yet. It was therefore our objective to study the cost-utility of HDF versus haemodialysis (HD). Methods. A cost-utility analysis was performed using a Markov model. It included data from the Convective Transport Study (CONTRAST), a randomized controlled trial that compared online HDF with low-flux HD. Costs were estimated using a societal perspective. Probabilistic sensitivity analyses were performed to study uncertainty. Results. Total annual costs for HDF and HD were (sic)88 622 +/- 19 272 and (sic)86 086 +/- 15 945, respectively (in 2009 euros). When modelled over a 5-year period, the incremental cost per quality-adjusted life year (QALY) of HDF versus HD was (sic)287 679. Sensitivity analyses revealed that this amount will not fall below (sic)140 000, even under the most favourable assumptions like a high-convection volume (>20.3 L). Conclusions. Based on accepted societal willingness-to-pay thresholds, HDF cannot be considered a cost-effective treatment for patients with end-stage renal disease at present. Apparently, minor additional costs of HDF are not counterbalanced by a relevant QALY gain

    4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

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    Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

    Nutrition research

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