7,152 research outputs found

    Shortening of the Short Refractory Periods in Short QT Syndrome.

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    BACKGROUND: Diagnosis of short QT syndrome (SQTS) remains difficult in case of borderline QT values as often found in normal populations. Whether some shortening of refractory periods (RP) may help in differentiating SQTS from normal subjects is unknown. METHODS AND RESULTS: Atrial and right ventricular RP at the apex and right ventricular outflow tract as determined during standard electrophysiological study were compared between 16 SQTS patients (QTc 324±24 ms) and 15 controls with similar clinical characteristics (QTc 417±32 ms). Atrial RP were significantly shorter in SQTS compared with controls at 600- and 500-ms basic cycle lengths. Baseline ventricular RP were significantly shorter in SQTS patients than in controls, both at the apex and right ventricular outflow tract and for any cycle length. Differences remained significant for RP of any subsequent extrastimulus at any cycle length and any pacing site. A cut-off value of baseline RP <200 ms at the right ventricular outflow tract either at 600- or 500-ms cycle length had a sensitivity of 86% and a specificity of 100% for the diagnosis of SQTS. CONCLUSIONS: Patients with SQTS have shorter ventricular RP than controls, both at baseline during various cycle lengths and after premature extrastimuli. A cut-off value of 200 ms at the right ventricular outflow tract during 600- and 500-ms basic cycle length may help in detecting true SQTS from normal subjects with borderline QT values

    La transmission d'Aristote par les Arabes à la chrétienté occidentale. Une trouvaille relative au De Interpretatione

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    En el capitulo VII de Sobre la interpretación, Aristóteles mutila un sistema de tres pares de proposiciones contradictorias naturales. Aristóteles excluye el par de proposiciones universales naturales, los hombres son blancos, los hombres no son blancos, los cuales se contradicen mutuamente. Esta mutilación lleva consigo consecuencias indeseables. Los dos pares de proposiciones contradictorias naturales, consideradas exclusivamente por Aristóteles, Todos los hombres son blancos versus Algunos hombres no son blancos y Algunos hombres son blancos versus Ningún hombre es blanco son ilegítimamente identificadas con los dos pares de proposiciones contradictorias lógicas, las cuales constituyen el cuadrado lógico: A versus O y I versus E respectivamente. De este modo, se confunden el nivel del lenguaje natural y el de la lógica. Dicha mutilación aristotélica se ve disimulada por la traducci6n de las llamadas proposiciones indeterminadas. Para traducir estas ultimas, semánticamente proposiciones particulares, los eruditos, excepto P. Gohlke utilizan las dos universales excluidas por el maestro. La obra de I. Pollak, publicada en Leipzig en 1913, nos revela el origen de este desliz de traducción casi universal: la versión árabe utilizada, desafortunadamente, por Al-Farabi en su comentario. Añadiendo los vértices Y y U a los del cuadrado, el hexágono lógico de Robert Blanche nos permite distinguir claramente la relación existente entre el sistema lógico y el sistema natural.In chapter VII of On Interpretation, Aristotle alters a system of three pairs of natural contradictory propositions, in that he ignores the pair where two natural universals Men are white, Men are not white oppose each other contradictorily. This alteration has serious consequences: the two natural pairs, which Aristotle considers exclusively: All men are white versus Some men are not white and Some men are white versus No man is white are illegitimately identified to the two pairs of logical contradictories constituting the logical square: A versus 0 and I versus E respectively. Thus, the level of natural language and that of logic are confused. The unfortunate Aristotelian alteration is concealed by the translation of propositions known as indeterminates. To translate these, which, semantically, are particulars, all scholars, except for P.Gohlke, employ the two natural universals excluded by the master! The work of I. Pollak, published in Leipzig in 1913, reveals the origin of this nearly universal translation mistake: the Arabic version upon which AI-Farabi unfortunately bases his comment. In adding the vertices Y and U to the four ones of the square, the logical hexagon of Robert Blanche allows for the understanding of the manner in which the logical system and the natural system are linked

    From Inception to Execution: Query Management for Complex Event Processing as a Service

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    International audienceComplex Event Processing (CEP) is a set of tools and techniques that can be used to obtain insights from high- volume, high-velocity continuous streams of events. CEP-based systems have been adopted in many situations that require prompt establishment of system diagnostics and execution of reaction plans, such as in monitoring of complex systems. This article describes the Query Analyzer and Manager (QAM) mod- ule, a first effort toward the development of a CEP as a Service (CEPaaS) system. This module is responsible for analyzing user-defined CEP queries and for managing their execution in distributed cloud-based environments. Using a language-agnostic internal query representation, QAM has a modular design that enables its adoption by virtually any CEP system

    Query Analyzer and Manager for Complex Event Processing as a Service

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    Complex Event Processing (CEP) is a set of tools and techniques that can be used to obtain insights from high-volume, high-velocity continuous streams of events. CEP-based systems have been adopted in many situations that require prompt establishment of system diagnostics and execution of reaction plans, such as in monitoring of complex systems. This article describes the Query Analyzer and Manager (QAM) module, a first effort toward the development of a CEP as a Service (CEPaaS) system. This module is responsible for analyzing user-defined CEP queries and for managing their execution in distributed cloud-based environments. Using a language-agnostic internal query representation, QAM has a modular design that enables its adoption by virtually any CEP system

    Modelling and simulating change in reforesting mountain landscapes using a social-ecological framework

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    Natural reforestation of European mountain landscapes raises major environmental and societal issues. With local stakeholders in the Pyrenees National Park area (France), we studied agricultural landscape colonisation by ash (Fraxinus excelsior) to enlighten its impacts on biodiversity and other landscape functions of importance for the valley socio-economics. The study comprised an integrated assessment of land-use and land-cover change (LUCC) since the 1950s, and a scenario analysis of alternative future policy. We combined knowledge and methods from landscape ecology, land change and agricultural sciences, and a set of coordinated field studies to capture interactions and feedback in the local landscape/land-use system. Our results elicited the hierarchically-nested relationships between social and ecological processes. Agricultural change played a preeminent role in the spatial and temporal patterns of LUCC. Landscape colonisation by ash at the parcel level of organisation was merely controlled by grassland management, and in fact depended on the farmer's land management at the whole-farm level. LUCC patterns at the landscape level depended to a great extent on interactions between farm household behaviours and the spatial arrangement of landholdings within the landscape mosaic. Our results stressed the need to represent the local SES function at a fine scale to adequately capture scenarios of change in landscape functions. These findings orientated our modelling choices in the building an agent-based model for LUCC simulation (SMASH - Spatialized Multi-Agent System of landscape colonization by ASH). We discuss our method and results with reference to topical issues in interdisciplinary research into the sustainability of multifunctional landscapes
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