1,221 research outputs found
Aproximaciones al itinerario de un género teatral en el siglo XVII, a propósito de las loas palaciegas de Calderón de la Barca
Después de trazar un panorama general sobre los primeros estadios de la evolución de la loa como género teatral durante los siglos XVI y XVII, este artículo se ocupa de fijar los principales rasgos que pueden definir sus funciones dramáticas en el momento en el que el teatro adquiere plena vigencia como espectáculo plenamente profesionalizado. En el marco de esta nueva experiencia teatral, la loa, el género encargado de establecer la inicial connivencia con el público, debe considerarse desde su naturaleza circunstancial. Asumida la dependencia espectacular del género y las estrategias dramáticas que se derivan de ello, la siguiente parte del artículo se ocupa de analizarlas en las ocho loas palaciegas de Calderón de la Barca de las que tenemos noticia
Integral equation mei applied to three-dimensional arbitrary surfaces
The authors present a new formulation of the integral equation of the measured equation of invariance (MEI) as a confined field integral equation discretised by the method of moments, in which the use of numerically derived testing functions results in an approximately sparse linear system with storage memory requirements and a CPU time for computing the matrix coefficients proportional to the number of unknowns.Peer ReviewedPostprint (published version
Ultrasonic characterization of the pulmonary venous wall: echographic and histological correlation
Background: Pulmonary vein isolation with radiofrequency catheter ablation techniques is used to prevent recurrences of human atrial fibrillation. Visualization of the architecture at the venoatrial junction could be crucial for these ablative techniques. Our study assesses the potential for intravascular ultrasound to provide this information.
Methods and Results: We retrieved 32 pulmonary veins from 8 patients dying from noncardiac causes. We obtained cross-sectional intravascular ultrasound (IVUS) images with a 3.2F, 30-MHz ultrasound catheter at intervals on each vein. Histological cross-sections at the intervals allowed comparisons with ultrasonic images. The pulmonary venous wall at the venoatrial junction revealed a 3-layered ultrasonic pattern. The inner echogenic layer represents both endothelium and connective tissue of the media (mean maximal thickness, 1.4±0.3 mm). The middle hypoechogenic stratum corresponds to the sleeves of left atrial myocardium surrounding the external aspect of the venous media. This layer was thickest at the venoatrial junction (mean maximal thickness, 2.6±0.8 mm) and decreased toward the lung hilum. The outer echodense layer corresponds to fibro-fatty adventitial tissue (mean maximal thickness, 2.15±0.36 mm). We found a close agreement among the IVUS and histological measurements for maximal luminal diameter (mean difference, -0.12±1.3 mm) and maximal muscular thickness (mean difference, 0.17±0.13 mm) using the Bland and Altman method.
Conclusions: Our experimental study demonstrates for the first time that IVUS images of the pulmonary veins can provide information on the distal limits and thickness of the myocardial sleeves and can be a valuable tool to help accurate targeting during ablative procedures
Matroids and Quantum Secret Sharing Schemes
A secret sharing scheme is a cryptographic protocol to distribute a secret
state in an encoded form among a group of players such that only authorized
subsets of the players can reconstruct the secret. Classically, efficient
secret sharing schemes have been shown to be induced by matroids. Furthermore,
access structures of such schemes can be characterized by an excluded minor
relation. No such relations are known for quantum secret sharing schemes. In
this paper we take the first steps toward a matroidal characterization of
quantum secret sharing schemes. In addition to providing a new perspective on
quantum secret sharing schemes, this characterization has important benefits.
While previous work has shown how to construct quantum secret sharing schemes
for general access structures, these schemes are not claimed to be efficient.
In this context the present results prove to be useful; they enable us to
construct efficient quantum secret sharing schemes for many general access
structures. More precisely, we show that an identically self-dual matroid that
is representable over a finite field induces a pure state quantum secret
sharing scheme with information rate one
First record of Oligochoerus limnophilus (Acoela, Acoelomorpha) from British waters
Primer registro de Oligochoerus limnophilus (Acoela, Acoelomorpha) en aguas británicas
Informamos de la existencia de poblaciones del acelo Oligochoerus limnophilus (Acoelomorpha) en la islas Británicas sobre la base de los especímenes capturados en el río Támesis (también conocido localmente como río Isis) a su paso por Oxford, Inglaterra, ampliando así considerablemente el área de distribución de la especie, restringida hasta ahora al continente europeo. La información gráfica que aportamos, imágenes de especímenes vivos y proyecciones CLSM de estructuras informativas seleccionadas por su valor sistemático, corrobora su estrecha relación con el género Convoluta Ørsted, 1843.We report the occurrence of the acoel Oligochoerus limnophilus (Acoelomorpha) from the British Islands, based on specimens captured in the river Thames (locally known as the river Isis) in Oxford, England, thereby considerably widening the distributional range of the species that had formerly been reported only from continental Europe. We further present live images and CLSM-projections of systematically informative structures that corroborate a close relationship with the genus Convoluta Ørsted, 1843.Primer registre d'Oligochoerus limnophilus (Acoela, Acoelomorpha) en aigües britàniques
Informem de l'existència de poblacions de l'acel Oligochoerus limnophilus (Acoelomorpha) a les illes Britàniques sobre la base dels espècimens capturats al riu Tàmesi (també conegut localment com a riu Isis) al pas per Oxford, Anglaterra, amb la qual cosa ampliem considerablement l'àrea de distribució de l'espècie, restringida fins ara al continent europeu. La informació gràfica que aportem, imatges d'espècimens vius i projeccions CLSM d'estructures informatives seleccionades pel seu valor sistemàtic, corrobora l'estreta relació amb el gènere Convoluta Ørsted, 1843
Time-resolved broadband analysis of slow-light propagation and superluminal transmission of electromagnetic waves in three-dimensional photonic crystals
A time-resolved analysis of the amplitude and phase of THz pulses propagating
through three-dimensional photonic crystals is presented. Single-cycle pulses
of THz radiation allow measurements over a wide frequency range, spanning more
than an octave below, at and above the bandgap of strongly dispersive photonic
crystals. Transmission data provide evidence for slow group velocities at the
photonic band edges and for superluminal transmission at frequencies in the
gap. Our experimental results are in good agreement with
finite-difference-time-domain simulations.Comment: 7 pages, 11 figure
Children's biobehavioral reactivity to challenge predicts DNA methylation in adolescence and emerging adulthood.
A growing body of research has documented associations between adverse childhood environments and DNA methylation, highlighting epigenetic processes as potential mechanisms through which early external contexts influence health across the life course. The present study tested a complementary hypothesis: indicators of children's early internal, biological, and behavioral responses to stressful challenges may also be linked to stable patterns of DNA methylation later in life. Children's autonomic nervous system reactivity, temperament, and mental health symptoms were prospectively assessed from infancy through early childhood, and principal components analysis (PCA) was applied to derive composites of biological and behavioral reactivity. Buccal epithelial cells were collected from participants at 15 and 18 years of age. Findings revealed an association between early life biobehavioral inhibition/disinhibition and DNA methylation across many genes. Notably, reactive, inhibited children were found to have decreased DNA methylation of the DLX5 and IGF2 genes at both time points, as compared to non-reactive, disinhibited children. Results of the present study are provisional but suggest that the gene's profile of DNA methylation may constitute a biomarker of normative or potentially pathological differences in reactivity. Overall, findings provide a foundation for future research to explore relations among epigenetic processes and differences in both individual-level biobehavioral risk and qualities of the early, external childhood environment
Convenciones del género de capa y espada en la década de 1630: «El doctor Carlino», de Antonio de Solís
En este estudio se presenta un análisis de las convenciones de género de la comedia de capa y espada y su inversión paródica en El doctor Carlino, de Antonio de Solís. En la década de 1630 la comedia de capa y espada se vuelve cada vez más ingeniosa y el trabajo examina cómo Solís ensaya nuevas fórmulas, por medio del protagonismo de este falso médico gongorino, el tratamiento del espacio y el tiempo y la generalización del agente cómico.This study presents an analysis of the conventions of the cloak and sword play and their parodic inversion in Solís’ El doctor Carlino. In the decade of 1630 the cloak and sword play becomes wittier and this essay studies how Solís experiments with these new ways by mixing the prominence of this false doctor —a character drawn from Gongora—, the treatment of space and time and the generalisation of the comical effect
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