6,473 research outputs found

    Fraction-like ratings from preferential voting

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    A method is given for resolving a matrix of preference scores into a well-specfied mixture of options. This is done in agreement with several desirable properties, including the continuity of the mixing proportions with respect to the preference scores and a condition of compatibility with the Condorcet-Smith majority principle. These properties are achieved by combining the classical rating method of Zermelo with a projection procedure introduced in previous papers of the same authors

    Effectively four-dimensional spacetimes emerging from d=5 Einstein-Gauss-Bonnet Gravity

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    Einstein-Gauss-Bonnet gravity in five-dimensional spacetime provides an excellent example of a theory that, while including higher-order curvature corrections to General Relativity, still shares many of its features, such as second-order field equations for the metric. We focus on the largely unexplored case where the coupling constants of the theory are such that no constant-curvature solution is allowed, leaving open the question of what the vacuum state should then be. We find that even a slight deviation from the anti-de Sitter Chern-Simons theory, where the vacuum state is five-dimensional AdS spacetime, leads to a complete symmetry breakdown, with the fifth dimension either being compactified into a small circle or shrinking away exponentially with time. A complete family of solutions, including duality relations among them, is uncovered and shown to be unique within a certain class. This dynamical dimensional reduction scenario seems particularly attractive as a means for higher-dimensional theories to make contact with our four-dimensional world.Comment: 9 pages, 4 figures. v2: New section on geometrical significance of solutions. Final version for CQ

    Atypical enteropathogenic Escherichia coli (aEPEC) in children under five years old with diarrhea in Quito (Ecuador)

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    Enteropathogenic Escherichia coli (EPEC) remain one the most important pathogens infecting children and they are one of the main causes of persistent diarrhea worldwide. In this study, we have isolated EPEC from 94 stool samples of children under five years old with diarrheal illness in the area of Quito (Ecuador), and we have determined the occurrence of the two subtypes of EPEC, typical EPEC (tEPEC) and atypical (aEPEC), by PCR amplification of the genes eae (attaching and effacing) and bfp (bundle- forming pilus). Typical EPEC is positive for eae and bfp genes while aEPEC is positive only for eae. Our results suggest that aEPEC is the most prevalent subtype in Quito (89.36 %), while subtype tEPEC is less prevalent (10.64 %). [Int Microbiol 19(3):157-160 (2016)]Keywords: Escherichia coli · atypical EPEC · genes eae and bfp · diarrhea in children · Quito (Ecuador

    Macrodistrofia lipomatosa en el pie: A propósito de un caso y revisión de la literatura

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    La macrofistrofia lipomatosa es una forma de gigantismo localizado poco frecuente y de causa desconocida, se caracteriza por un gran aumento del crecimiento de todos los elementos mesenquimales, en particular el tejido fibroadiposo de uno o varios dedos del pie o de la mano. Nosotros presentamos un paciente con una deformidad estática en el primer dedo del pie derecho, con una discusión de los hallazgos clínicos, patológicos y radiológicos, así como una revisión de la bibliografía.Macrodystrophia Lipomatosa, a rare form of localized gigantism of unknown cause, is characterized by a dramatic overgrowth of all the mesenchymal elements, paricularly the fibroadipose tissue, of one or more digits of the foot or hand. We report the case of an patient, who had a static deformity of the first toe of the right food. The clinical, pathologic, and roentgenographic findings are discussed and review of the literature is provided

    Síndrome de edema transitorio de médula ósea en tibia. A propósito de un caso

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    El término "Síndrome de edema transitoro de médula ósea" (SETMO) se utiliza para definir un modelo de edema óseo difuso en imágenes por RNM, en ausencia de osteopenia demostrada radiológicamente y en el cual se descarte otro diagnóstico. La localización más frecuente es a nivel femoral proximal, aunque puede observare en rodillas, tobillos, y con menor frecuencia a nivel de diáfisis tibial, donde han sido descritos cuatro casos. En nuestro trabajo presentamos un caso de SETMO localizado en diáfisis de tibia, resuelto espontáneamente a los 4 meses, y que tras un periodo de seguimiento de tres años permanece asintomático.The term "Transient bone marrow edema" (TBME like Síndrome) is utilized to define a model of bone marrow edema diffuse in images by MR, in absence of osteopenia shown by means of radiologic diagnosis and in which another diagnosis be discarded. The most frequent locating is in the proximal femur, although can be observed in knee, ankle, and with smaller frequency to level of tibial diaphysis, where they have been described four cases. In our study we present a case of TBME located in tibial diaphysis, resolved spontaneously to the 4 months, and that after a period of follow-up of three years remains without symptoms

    Relación entre calidad y coste de la prescripción farmacológica en atención primaria

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    ObjetivoAnalizar la prescripcion farmaceutica de los medicos generales (MG) segun un sistema de indicadores cualitativos y evaluar la relacion de estos con el gasto global de prescripcion farmaceutica por habitante.DisenoEstudio descriptivo, retrospectivo.EmplazamientoAtencion primaria.Mediciones y resultados principalesSe evalua la prescripcion farmaceutica de 285 MG de 32 equipos de atencion primaria, siendo la prescripcion individual de cada medico la unidad de analisis. La prescripcion se clasifico en 3 categorias segun su valor intrinseco (%VIF): bajo (. 75%), medio (76–79%) y alto (. 80%). Como trazadores de hiperprescripcion fueron seleccionados: DHD antibioticos (AB), DHD antiinflamatorios no esteroides (AINE) y DHD antiulcerosos (ULC), y como trazadores de seleccion: %DHD cefalosporinas tercera generacion/DHD cefalosporinas totales (CEF3.aG), %DHD quinolonas amplio espectro/DHD quinolonas totales (QAP), %DHD AINE/DHD (AINE + analgesicos) (ANAL). Los indicadores cuantitativos estudiados fueron: gasto total/poblacion asignada (GPA), coste/receta farmacos de eficacia dudosa y coste/DDD de AB, AINE y ULC. Se aplico el analisis de variancia, incluyendo la prueba de Scheffe para comparaciones multiples y la correlacion lineal de Pearson. Un 26% de las prescripciones tenia un %VIF < 75%, mientras que el 34% lo tenia > 80%. Las medias de DHD AB entre las categorias de VIF eran diferentes (p < 0,0001), al igual que las de DHD de AINE (p < 0,0001) y ULC (p = 0,007), observandose un menor consumo de AB, AINE y ULC en las prescripciones con VIF mas alto. Las CEF3aG, asi como ANAL presentan diferencias significativas con las 3 categorias de VIF (p < 0,0001 y p = 0,041) a diferencia del QAP (p = 0,18). El GPA es menor entre los MG cuyas prescripciones tenian el %VIF mas alto; en cambio, el coste/receta y el coste DDD no presentaron diferencias significativas segun categorias de %VIF.ConclusionesLos medicos con mejor perfil cualitativo segun estos indicadores presentan un menor gasto por habitante. En cambio, no se observan diferencias en el coste por receta ni en el coste/tratamiento entre los distintos medicos. Por tanto, las intervenciones deben priorizar la mejora de la calidad de la prescripcion farmaceutica antes que promover unicamente el cambio al farmaco de menor coste.ObjectivesWith a system of qualitative indicators, to analyse the pharmaceutical prescription of general practitioners (GPs), and to evaluate the relationship of these indicators to the overall pharmaceutical prescription expenditure per inhabitant.DesignRetrospective descriptive study.SettingPrimary care.Measurements and main resultsThe drugs prescription of 285 GPs from 32 primary care teams was evaluated, with the individual prescription of each doctor as the unit of analysis. The prescription was classified in 3 categories according to its intrinsic value (IV): low (. 75%), medium (76–79%) and high (. 80%). Selected as tracers of over-prescription were: daily dose per inhabitant (DDI) of antibiotics (AB), DDI of non-steroid anti-inflammatory drugs (NSAID), and DDI of ulcer drugs (ULC). Selected as tracers of selection were: % DDI third-generation cephalosporins/DDI total cephalosporins; % DDI broad-spectre quinolones/DDI total quinolones; and % DDI NSAID/DDI NSAID plus analgesics. Quantitative indicators studied were: total expenditure per allocated population, cost per drugs prescription of doubtful efficacy, and cost per daily dose of AB, NSAID and ULC. Variance analysis, including the Scheffe test for multiple comparisons and Pearson's linear correlation, was applied. 26% of the prescriptions had an IV below 75%, and 34% had an IV above 80%. The means of DDI of AB among the categories of IV were different (p < 0.0001), as were those of DDI of NSAID (p < 0.0001) and of ULC (p = 0.007). Lower consumption of AB, NSAID and ULC was found in prescriptions with the highest IV %. The third-generation cephalosporins and the NSAID + analgesics showed significant differences in the three IV categories (p < 0.0001 and p = 0.041), unlike broad-spectrum quinolones (p = 0.18). The total expenditure per allocated population was less for GPs whose prescriptions had the highest IV %; whereas the cost per prescription and cost per daily dose showed no significant differences for IV categories.ConclusionsThe doctors with the best qualitative profile on these indicators had less expenditure per inhabitant. However, no differences were found in the cost per prescription or cost per treatment between doctors. Therefore, interventions must prioritise improving drug prescription quality rather than just promoting changes to lower-cost drugs

    Maximizing friction by liquid flow clogging in confinement

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    In the nanoscale regime, flow behaviors for liquids show qualitative deviations from bulk expectations. In this work, we reveal by molecular dynamics simulations that plug flow down to nanoscale induces molecular friction that leads to a new flow structure due to the molecular clogging of the encaged liquid. This plug-like nanoscale liquid flow shows several features differ from the macroscopic plug flow and Poiseuille flow: It leads to enhanced liquid/solid friction, producing a friction of several order of magnitude larger than that of Couette flow; the friction enhancement is sensitively dependent of the liquid column length and the wettability of the solid substrates; it leads to the local compaction of liquid molecules that may induce solidification phenomenon for a long liquid column

    Steps in the bacterial flagellar motor

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    The bacterial flagellar motor is a highly efficient rotary machine used by many bacteria to propel themselves. It has recently been shown that at low speeds its rotation proceeds in steps [Sowa et al. (2005) Nature 437, 916--919]. Here we propose a simple physical model that accounts for this stepping behavior as a random walk in a tilted corrugated potential that combines torque and contact forces. We argue that the absolute angular position of the rotor is crucial for understanding step properties, and show this hypothesis to be consistent with the available data, in particular the observation that backward steps are smaller on average than forward steps. Our model also predicts a sublinear torque-speed relationship at low torque, and a peak in rotor diffusion as a function of torque

    Influence of carbon on intraband scattering in Mg(B1-xCx)2

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    We report data on the Hall coefficient (RH) of the carbon substituted Mg(B1-xCx)2 single crystals with x in the range from 0 to 0.1. The temperature dependences of RH obtained for the substituted crystals differ systematically at low temperatures, but all of them converge to the value of 1.8 x 10^-10 m^3/C at room temperature. The RH(T) data together with results of the thermoelectric power and electrical resistivity measurements are interpreted within a quasi-classical transport approach, where the presence of four different conducting sheets is considered. The main influence of the carbon substitution on the transport properties in the normal state is associated with enhanced scattering rates, rather than modified concentration of charge carriers. Presumably the carbon substitution increases the electron-impurity scattering mainly in the pi band.Comment: 16 pages, 3 figure
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