Ballistic Localization in Quasi-1D Waveguides with Rough Surfaces

Structure of eigenstates in a periodic quasi-1D waveguide with a rough surface is studied both analytically and numerically. We have found a large number of "regular" eigenstates for any high energy. They result in a very slow convergence to the classical limit in which the eigenstates are expected to be completely ergodic. As a consequence, localization properties of eigenstates originated from unperturbed transverse channels with low indexes, are strongly localized (delocalized) in the momentum (coordinate) representation. These eigenstates were found to have a quite unexpeted form that manifests a kind of "repulsion" from the rough surface. Our results indicate that standard statistical approaches for ballistic localization in such waveguides seem to be unappropriate.Comment: 5 pages, 4 figure

Reaction Dynamics for the Systems 7Be,8B + 208Pb at Coulomb Barrier Energies

In this contribution we describe the first results obtained for the investigation of the elastic scattering process in the reactions induced by the Radioactive Ion Beams 7Be and 8B on a 208Pb target at Coulomb barrier energies. The experimental data were analyzed within the framework of the optical model in order to extract the total reaction cross section. The comparison with data available in literature for reactions induced on 208Pb by light ions in the mass range A = 6-8 shows that the loosely-bound 8B has the largest reactivity

\b{eta}-delayed three-proton decay of 31Ar

The beta decay of 31Ar, produced by fragmentation of a 36Ar beam at 880 MeV/nucleon, was investigated. Identified ions of 31Ar were stopped in a gaseous time projection chamber with optical readout allowing to record decay events with emission of protons. In addition to \b{eta}-delayed emission of one and two protons we have clearly observed the beta-delayed three-proton branch. The branching ratio for this channel in 31Ar is found to be 0.07(2)%.Comment: 5 pages, 3 figures, submitted to Physical Rev.

Maternidad subrogada analizada desde la legislación de Colombia, España y Estados Unidos

Artículo de investigaciónEste artículo aborda el debate que se ha presentado sobre el tema de la maternidad subrogada desde la perspectiva de la legislación existente sobre el tema en los países de Estados Unidos, España y Colombia, evidenciado la necesidad que tiene nuestro país de emitir leyes jurídicas frente a la reproducción asistida, para que de esta manera exista una seguridad jurídica que blinde este tipo de prácticas científicas.44 p.INTRODUCCIÓN 1. TECNICAS DE REPRODUCCION ASISTIDA 2. ARGUMENTOS SOBRE MATERNIDAD SUBROGADA 3. MATERNIDAD SUBROGADA EN EL DERECHO COMPARADO 4. APLICACIÓN EN COLOMBIA 5. DERECHOS CONSTITUCIONALES DE LOS NIÑOS Y LAS NIÑAS CONCLUSIONES BIBLIOGRAFÍAPregradoAbogad

El registro ENEIDA (Estudio Nacional en Enfermedad Inflamatoria intestinal sobre Determinantes genéticos y Ambientales) de GETECCU: diseño, monitorización y funciones

El registro ENEIDA, promovido por el Grupo Español de Trabajo en Enfermedad de Crohn y Colitis Ulcerosa (GETECCU), fue creado en 2005 por un grupo de gastroenterólogos interesados en mejorar el manejo de los pacientes con enfermedad inflamatoria intestinal. Los objetivos principales del registro fueron facilitar la recogida de datos clínicos de interés para la práctica clínica asistencial, así como la elaboración de estudios colaborativos a partir de datos clínicos y muestras biológicas. En sus 15 años de existencia, ENEIDA ha evolucionado en múltiples aspectos, desde su contenido o su soporte tecnológico hasta el número de centros participantes, para convertirse en uno de los registros de referencia para el estudio y cuidado de los pacientes con enfermedad inflamatoria intestinal, con una producción científica continua y de alta calidad que lo ha situado como ejemplo de explotación científica colaborativa en el ámbito internacional. En este artículo se revisan los objetivos, el diseño, las características estructurales, la monitorización y la explotación científica del registro ENEIDA

Erratum: The afterglow and kilonova of the short GRB 160821B

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Cross-species chromosome painting tracks the independent origin of multiple sex chromosomes in two cofamiliar Erythrinidae fishes

<p>Abstract</p> <p>Background</p> <p>The Erythrinidae fish family is characterized by a large variation with respect to diploid chromosome numbers and sex-determining systems among its species, including two multiple X₁X₂Y sex systems in <it>Hoplias malabaricus </it>and <it>Erythrinus erythrinus</it>. At first, the occurrence of a same sex chromosome system within a family suggests that the sex chromosomes are correlated and originated from ancestral XY chromosomes that were either homomorphic or at an early stage of differentiation. To identify the origin and evolution of these X₁X₂Y sex chromosomes, we performed reciprocal cross-species FISH experiments with two sex-chromosome-specific probes designed from microdissected X₁and Y chromosomes of <it>H. malabaricus </it>and <it>E. erythrinus</it>, respectively.</p> <p>Results</p> <p>Our results yield valuable information regarding the origin and evolution of these sex chromosome systems. Our data indicate that these sex chromosomes evolved independently in these two closed related Erythrinidae species. Different autosomes were first converted into a poorly differentiated XY sex pair in each species, and additional chromosomal rearrangements produced both X₁X₂Y sex systems that are currently present.</p> <p>Conclusions</p> <p>Our data provide new insights into the origin and evolution of sex chromosomes, which increases our knowledge about fish sex chromosome evolution.</p