3,664 research outputs found

    Rotura aguda completa del ligamento colateral metacarpo-falángico radial del pulgar: una lesión grave infrecuente

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    El ligamento colateral radial es el principal estabilizador articular contra las fuerzas de estrés en aducción de la articulación metacarpofalángica del pulgar. Esta lesión infrecuente, pasa a menudo desapercibida, desarrollándose una inestabilidad articular sintomática y, posteriormente, una artrosis secundaria. Aunque tradicionalmente se ha recomendado el tratamiento conservador de estas lesiones, estudios recientes han documentado mejores resultados funcionales cuando se realiza su reparación quirúrgica, especialmente en las lesiones completas.The radial collateral ligament is the primary stabilizer against stress forces in adduction of the metacarpophalangeal joint of the thumb. This uncommon injury may go unnoticed, resulting in symptomatic joint instability and secondary osteoarthritis. Although traditionally it has been recommended conservative treatment of these lesions, recently studies have documented better functional outcomes with surgical repair of complete ruptures

    Quantum Interference in Single Molecule Electronic Systems

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    We present a general analytical formula and an ab initio study of quantum interference in multi-branch molecules. Ab initio calculations are used to investigate quantum interference in a benzene-1,2-dithiolate (BDT) molecule sandwiched between gold electrodes and through oligoynes of various lengths. We show that when a point charge is located in the plane of a BDT molecule and its position varied, the electrical conductance exhibits a clear interference effect, whereas when the charge approaches a BDT molecule along a line normal to the plane of the molecule and passing through the centre of the phenyl ring, interference effects are negligible. In the case of olygoynes, quantum interference leads to the appearance of a critical energy EcE_c, at which the electron transmission coefficient T(E)T(E) of chains with even or odd numbers of atoms is independent of length. To illustrate the underlying physics, we derive a general analytical formula for electron transport through multi-branch structures and demonstrate the versatility of the formula by comparing it with the above ab-initio simulations. We also employ the analytical formula to investigate the current inside the molecule and demonstrate that large counter currents can occur within a ring-like molecule such as BDT, when the point charge is located in the plane of the molecule. The formula can be used to describe quantum interference and Fano resonances in structures with branches containing arbitrary elastic scattering regions connected to nodal sites.Comment: 12 pages, 11 figure

    CRÍTICA DECOLONIAL A LA EPISTEME JURÍDICA HEGEMÓNICA

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    En estas reflexiones se busca desarrollar -dentro de las posturas teórico-críticas del derecho- la crítica a la episteme jurídica positivista (actualmente hegemónica en nuestros Estados “modernos”) desde una postura decolonial.  Para ello, se asume la crítica en el ámbito del Derecho, considerando la necesidad de impugnar las colonialidades que “normalizan” la gramática cultural dominante, interpelada desde la exterioridad.  En función de ello, se plantea cuestionar los presupuestos epistemológicos de la juridicidad hegemónica -positivista-, según las categorías subyacentes que ésta impone: a) Desde la colonialidad del ser: un dualismo ontológico; b) Desde la colonialidad del saber: una dicotomía epistémica, de la que derivan: a. una espacialidad y una temporalidad (que se reproducen -endocolonialmente- mediante una genealogía); c) Desde la colonialidad de la naturaleza: una dualidad antropocéntrica; d) Desde la colonialidad jurídica: un monismo jurídico. Estos presupuestos -y su crítica correspondiente- se desarrollan en este texto

    An intelligent strategy for tactical movements of UAVs in disaster scenarios

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    Unmanned Aerial Vehicles (UAVs) are envisioned as flexible and fast-deploying communication network for disaster scenarios, where the typical communication infrastructure is likely to be malfunctioning. A few works propose UAVs for building communication links autonomously between rescue team’s members in disaster scenarios. The techniques used are usually based on navigation, positioning, and signal strength processing. However, these techniques may not be enough if the objective is to provide communication services to the maximum number of victims and rescuers and not only to a few rescuers. In this situation, dissimilarity metrics, like the Jaccard distance, can provide information about whether the communication service provided to victims is efficient or not (e.g., providing a better distribution of the victims assigned to each UAV acting as service provider). We propose an intelligent strategy that allows UAVs to perform tactical movements in a disaster scenario, combining the Jaccard distance and artificial intelligence algorithms like hill climbing and simulated annealing. Our strategy maximizes the number of victims that are serviced by the UAVs while avoiding network disconnections. Also, a mobility model specifically developed for modelling the victims’ movements within the incident site of a disaster scenario is propose

    On-siteDriverID: A secure authentication scheme based on Spanish eID cards for vehicular ad hoc networks

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    Security in Vehicle Ad Hoc Networks (VANETs) has been a topic of interest since the origins of vehicular communications. Different approaches have been followed as new security threats have emerged in the last few years. The approach of conditional privacy has been widely used as it guarantees authentication among vehicles but not revealing their real identities. Although the real identity of the vehicle can be traced by the authorities, the process to do that is time consuming and typically involves several entities (for instance road authorities that request the identification, license plate records bodies, a judge to allow revealing the identity associated to a license plate…). Moreover, this process is always subsequent to the detection of a road situation that requires knowing the real vehicle identities. However, in vehicular scenarios, authorities would beneficiate from knowing the real drivers’ identity in advance. We propose in this paper On-SiteDriverID, a secure protocol and its application which allows authorities’ vehicles to obtain drivers’ real identities rapidly and on demand on VANET scenarios. Thus, authorities would be able to gather information about drivers and vehicles, allowing them to act in a safer and better manner in situations such as traffic control duties or emergencies. The obtained simulation results in real VANET scenarios based on real maps guarantee that in the 60–70% of cases the proposed On-SiteDriverID successfully obtains the identity of the driver

    An evaluation methodology for reliable simulation based studies of routing protocols in VANETs

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    Vehicular Ad hoc networks (VANETs) have attracted much attention in the last decade. Many routing protocols have been proposed for VANETs and their performance is usually evaluated and compared using simulation-based studies. However, conducting reliable simulation studies is not a trivial task since many simulation parameters must be configured correctly. The selected parameters configuration can considerably affect the simulation results. This paper presents a methodology for conducting reliable simulations of routing protocols in VANETs urban scenarios. The proposed methodology includes relevant simulation aspects such as measurement period, selection of source-destination pairs for the communication traffic flows, number of simulations, mobility models based on road city maps, performance metrics and different analyses to evaluate routing protocols under different conditions. The proposed methodology is validated by comparing the simulation results obtained for Ad Hoc On-Demand Distance Vector (AODV) routing protocol with and without using the proposed methodology. The obtained results confirm that by using the proposed methodology, we can achieve more reliable simulations of VANETs routing protocols.Universidad de Sevilla. V Plan Propio de InvestigaciónMinisterio de Economía y Competitividad DPI2013-44278-

    Precipitation variability and trends in Ghana: An intercomparison of observational and reanalysis products

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    Inter-annual variability and trends of annual/seasonal precipitation totals in Ghana are analyzed considering different gridded observational (gauge- and/or satellite-based) and reanalysis products. A quality-controlled dataset formed by fourteen gauges from the Ghana Meteorological Agency (GMet) is used as reference for the period 1961?2010. Firstly, a good agreement is found between GMet and all the observational products in terms of variability, with better results for the gauge-based products?correlations in the range of 0.7?1.0 and nearly null biases?than for the satellite-gauge merged and satellite-derived products. In contrast, reanalyses exhibit a very poor performance, with correlations below 0.4 and large biases in most of the cases. Secondly, a Mann-Kendall trend analysis is carried out. In most cases, GMet data reveal the existence of predominant decreasing (increasing) trends for the first (second) half of the period of study, 1961?1985 (1986?2010). Again, observational products are shown to reproduce well the observed trends?with worst results for purely satellite-derived data?whereas reanalyses lead in general to unrealistic stronger than observed trends, with contradictory results (opposite signs for different reanalyses) in some cases. Similar inconsistencies are also found when analyzing trends of extreme precipitation indicators. Therefore, this study provides a warning concerning the use of reanalysis data as pseudo-observations in Ghana.This study was supported by the EU project QWeCI (Quantifying Weather and Climate Impacts on health in developing countries), funded by the European Commission Seventh Framework Research Programme under the grant agreement 243964

    Cambios edáficos en las Marismas de Doñana y su relación con la invasión de Azolla filiculoide

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    2 páginas, 7 referencias. En el Capítulo: Degradación de suelos y desertificación. Simposio celebrado en Fuerteventura, 16-20, septiembre, 2007. Los editores son del Departamento de Edafología y Geología, Universidad de La Laguna.La Marisma de de Doñana es una extensa planicie dominada por suelos arcillosos, calcáreos y salinos (Clemente et al., 1998) que se inunda estacionalmente -por efecto de la lluvia y de algunos arroyos- y acoge a una de las poblaciones de aves acuáticas más importantes de Europa (Clemente et al. 2004). En 2001 uno de los autores (J.L. Espinar) documentó por primera vez la presencia del helecho de origen americano Azolla filliculoides, una especie invasora con capacidad para fijar el N atmosférico, que acabó extendiéndose por el humedal en los años siguientes (Cobo y Bañuls, 2005) En este trabajo se analizan los cambios ambientales ocurridos en la marisma de Doñana con anterioridad a la invasión, en relación con lo acaecido en anteriores episodios de invasión por Azolla de otras áreas naturales.Peer reviewe

    Anti-inflammatory activity of

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    The anti-inflammatory activity of the chloroform, methanol and aqueous extracts of Wigandia urens and Acalypha alopecuroides were investigated on carrageenan-induced paw edema at doses of 400 mg/kg. The three extracts of W. urens, and the aqueous extract of A. alopecuroides caused significantinhibition of the edema (58.1±6.5% and 63.5±5.4%, respectively). Indomethacin was used as positive control (8 mg/kg), and inhibited edema by 66.3±5.2%. The methanol extract of W. urens and the aqueous extract of A. alopecuroides, at doses of 200 mg/kg, inhibited pellet implantation-induced granuloma formation by 69.4±6.5 and 70.6±6.6%, respectively. These levels of inhibition are higher than those exhibited by naproxen at doses of 50 mg/kg (46.1±7.1%). Both extracts showed activity on adjuvantinduced arthritis in rats, with the best effect being observed after 96 h (82.2±4.6 and 80.6±7.3%, respectively)

    Evaluación de la severidad de la incontinencia urinaria de esfuerzo con estudios urodinámicos: un estudio comparativo para detectar deficiencia intrínseca del esfínter uretral externo

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    ResumenObjetivoDeterminar la sensibilidad y especificidad del punto de presión de fuga abdominal (ALPP), para evaluar la presencia de deficiencia intrínseca del esfínter (DIE) comparativamente con la presión máxima de cierre uretral (MUCP, por sus siglas en inglés), estableciendo la correlación clínico-urodinámica correspondiente.ResultadosFueron evaluadas 34 pacientes con incontinencia urinaria de esfuerzo (IUE); 17 paciente (50%) fueron diagnosticadas urodinámicamente con DIE por punto de ALPP; 9 tuvieron IUE severa mientras que sólo 2 (5.8%) lo fueron por MUCP, de las cuales una tuvo IUE severa y otra, IUE moderada. Dieciocho pacientes fueron catalogadas clínicamente como IUE severa, de las cuales 17 tuvieron DIE por ALPP entre severa y moderada (94%).ConclusionesLa evaluación urodinámica de la IUE permite establecer de manera clara la fisiopatología de una disfunción del tracto urinario inferior concomitante, con la posibilidad de objetivar la presencia de IUE con el ALPP en al menos 85% de los casos, con una sensibilidad y especificidad para diagnosticar DIE muy superior a la MUCP.AbstractAimsTo determine the sensitivity and specificity of the abdominal leak point pressure (ALPP) in order to comparatively evalúate the presence of intrinsic sphincter deficiency (ISD) with máximum urethral closure pressure (MUCP) and establish the corresponding clinical and urodynamic correlation.ResultsThirty-four patients with stress urinary incontinence (SUI) were evaluated. Seventeen of those patients (50%) were urodynamically diagnosed with ISD through ALPP and 9 of them had severe SUI. Only 2 patients were diagnosed with ISD through MUCP; one of them had severe SUI and the other presented with modérate SUI. Eighteen patients were clinically classified with severe SUI, 17 of whom had moderate to severe ISD diagnosed through ALPP (94%).ConclusionsUrodynamic evaluation of SUI made it possible to clearly establish the pathophysiology of concomitant lower urinary tract dysfunction and to objectify the presence of SUI through ALPP in at least 85% of the cases. ALPP had a much higher sensitivity and specificity for diagnosing ISD than MUCP
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