1,215 research outputs found

    Learning force patterns with a multimodal system using contextual cues

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    Previous studies on learning force patterns (fine motor skills) have focused on providing “punctual information”, which means users only receive information about their performance at the current time step. This work proposes a new approach based on “contextual information”, in which users receive information not only about the current time step, but also about the past (how the target force has changed over time) and the future (how the target force will change). A test was run to compare the performance of the contextual approach in relation to the punctual information, in which each participant had to memorize and then reproduce a pattern of force after training with a multimodal system. The findings suggest that the contextual approach is a useful strategy for force pattern learning. The advantage of the contextual information approach over the punctual information approach is that users receive information about the evolution of their performance (helping to correct the errors), and they also receive information about the next forces to be exerted (providing them with a better understanding of the target force profile). Finally, the contextual approach could be implemented in medical training platforms or surgical robots to extend the capabilities of these systems

    Evaluation of micromorphological changes in tooth enamel after mechanical and ultrafast laser preparation of surface cavities

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    The aim of this in vitro study was to evaluate the morphological changes that occur in tooth enamel after mechanical instrumentation and after femtosecond laser irradiation with different parameters via light and scanning electron microscopy (SEM). Twelve totally impacted third molars were collected and sectioned to provide several cut surfaces. These surfaces were exposed to infrared (λ = 795 nm, 120 fs, 1-kHz repetition rate, maximum mean power 1 W) laser pulses and machined by means of a conventional mechanical technique. Two very different geometrical patterns were performed with femtosecond laser pulses: shallow rectangular cavities and deep cylindrical ones. The results of both machining procedures were examined using light and scanning electron microscopy. The SEM images show the femtosecond laser ability to produce high-precision cavities in tooth enamel. No signs of collateral damage, burning, melting, or cracks were observed despite the far different laser pulse energies used (ranging from 7 to 400 μJ), unlike what is seen with conventional mechanical techniques. The femtosecond laser has the potential to become an optimal tool for the treatment of dental decay and as an alternative to the conventional drill to reduce mechanical damage during removal of the hard dental tissue.A.G. and P.M. acknowledge the support of Spanish Ministerio de Ciencia e Innovación through the Consolider Program SAUUL (CSD2007-00013) and research project FIS2009-09522, from Junta de Castilla y León through the Program for Groups of Excellence (GR27) and of the EC Seventh Framework Programme (LASERLAB-EUROPE, grant agreement no. 228334).We also acknowledge the support of the Centro de Laseres Pulsados, CLPU, Salamanca, Spain

    Incentivos fiscales y planificación fiscal de la empresa familiar española: un estudio empírico

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    La planificación fiscal de la empresa familiar es imprescindible para garantizar la supervivencia de la misma y poder hacer frente a los costes derivados de los impuestos. Sin embargo, la evidencia nos indica que las empresas familiares están más preocupadas por otros factores de éxito, tales como las relaciones familiares en el seno empresarial. En este trabajo, analizamos las relaciones existentes entre el establecimiento de incentivos del sistema fiscal y la planificación fiscal de la empresa familiar desde la perspectiva del familiness. Sobre la base de una muestra de 282 empresas familiares del sector industrial, se estudia la consistencia de las relaciones entre las dimensiones poder, experiencia y cultura familiar con la capacidad para planificar fiscalmente de las empresas familiares. Los resultados indican que, en general, las empresas familiares están interesadas por una adecuada planificación fiscal cuando se establecen incentivos fiscales que puedan considerar de interés para la adecuada gestión de la empresa familiar.

    Characterization of Implanted Stents through Neointimal Tissue Bioimpedance Simulations

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    This work describes how is possible the definition of the light hole or lumen in implanted stents affected by restenosis processes using the BioImpedance (BI) as biomarker. The main approach is based on the fact that neointimal tissues implied in restenosis can be detected and measured thanks to their respective conductivity and dielectric properties. For this goal, it is proposed a four-electrode setup for bioimpedance measurement. The influence of the several involved tissues in restenosis: fat, muscle, fiber, endothelium and blood, have been studied at several frequencies, validating the setup and illustrating the sensitivity of each one. Finally, a real example using a standard stent, has been analyzed for stable and vulnerable plaques in restenosis test cases, demonstrating that the proposed method is useful for the stent obstruction test. Bioimpedance simulation test has been performed using the electric physics module in COMSOL Multiphysics®.Junta de Andalucía 2017/TIC-17

    Standardizing effect size from linear regression models with log-transformed variables for meta-analysis

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    Background: Meta-analysis is very useful to summarize the effect of a treatment or a risk factor for a given disease. Often studies report results based on log-transformed variables in order to achieve the principal assumptions of a linear regression model. If this is the case for some, but not all studies, the effects need to be homogenized. Methods: We derived a set of formulae to transform absolute changes into relative ones, and vice versa, to allow including all results in a meta-analysis. We applied our procedure to all possible combinations of log-transformed independent or dependent variables. We also evaluated it in a simulation based on two variables either normally or asymmetrically distributed. Results: In all the scenarios, and based on different change criteria, the effect size estimated by the derived set of formulae was equivalent to the real effect size. To avoid biased estimates of the effect, this procedure should be used with caution in the case of independent variables with asymmetric distributions that significantly differ from the normal distribution. We illustrate an application of this procedure by an application to a meta-analysis on the potential effects on neurodevelopment in children exposed to arsenic and manganese. Conclusions: The procedure proposed has been shown to be valid and capable of expressing the effect size of a linear regression model based on different change criteria in the variables. Homogenizing the results from different studies beforehand allows them to be combined in a meta-analysis, independently of whether the transformations had been performed on the dependent and/or independent variables

    Changes in bread consumption and 4-year changes in adiposity in Spanish subjects at high cardiovascular risk

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    The effects of bread consumption change over time on anthropometric measures have been scarcely studied. We analysed 2213 participants at high risk for CVD from the PREvención con DIeta MEDiterránea (PREDIMED) trial to assess the association between changes in the consumption of bread and weight and waist circumference gain over time. Dietary habits were assessed with validated FFQ at baseline and repeatedly every year during 4 years of follow-up. Using multivariate models to adjust for covariates, long-term weight and waist circumference changes according to quartiles of change in energy-adjusted white and whole-grain bread consumption were calculated. The present results showed that over 4 years, participants in the highest quartile of change in white bread intake gained 0·76 kg more than those in the lowest quartile (P for trend = 0·003) and 1·28 cm more than those in the lowest quartile (P for trend 2 kg) and gaining waist circumference (>2 cm) during follow-up was not associated with increase in bread consumption, but participants in the highest quartile of changes in white bread intake had a reduction of 33 % in the odds of losing weight (>2 kg) and a reduction of 36 % in the odds of losing waist circumference (>2 cm). The present results suggest that reducing white bread, but not whole-grain bread consumption, within a Mediterranean-style food pattern setting is associated with lower gains in weight and abdominal fat

    Demographic and clinical profile of idiopathic pulmonary fibrosis patients in Spain: the SEPAR National Registry

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    BackgroundLittle is known on the characteristics of patients diagnosed with idiopathic pulmonary fibrosis (IPF) in Spain. We aimed to characterize the demographic and clinical profile of IPF patients included in the IPF National Registry of the Spanish Respiratory Society (SEPAR).MethodsThis is a prospective, observational, multicentre and nationwide study that involved 608 IPF patients included in the SEPAR IPF Registry up to June 27th, 2017, and who received any treatment for their disease. IPF patients were predominantly males, ex-smokers, and aged in their 70s, similar to other registries.ResultsUpon inclusion, meanSD predicted forced vital capacity was 77.6%+/- 19.4, diffusing capacity for carbon monoxide was 48.5%+/- 17.7, and the 6-min walk distance was 423.5m +/- 110.4. The diagnosis was mainly established on results from the high-resolution computed tomography in the proper clinical context (55.0% of patients), while 21.2% of patients required invasive procedures (surgical lung biopsy) for definitive diagnosis. Anti-fibrotic treatment was prescribed in 69.4% of cases, 51.5% pirfenidone and 17.9% nintedanib, overall with a good safety profile.Conclusions The SEPAR IPF Registry should help to further characterize current characteristics and future trends of IPF patients in Spain and compare/pool them with other registries and cohorts

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
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