Two Distinct, Geographically Overlapping Lineages of the Corallimorpharian Ricordea Florida (Cnidaria: Hexacorallia: Ricordeidae)

We examined the genetic variation of the corallimorpharian Ricordea florida; it is distributed throughout the Caribbean region and is heavily harvested for the marine aquarium trade. Eighty-four distinct individuals of R. florida were sequenced from four geographically distant Caribbean locations (Curaçao, Florida, Guadeloupe, and Puerto Rico). Analysis of the ribosomal nuclear region (ITS1, 5.8S, ITS2) uncovered two geographically partially overlapping genetic lineages in R. florida, probably representing two cryptic species. Lineage 1 was found in Florida and Puerto Rico, and Lineage 2 was found in Florida, Puerto Rico, Guadeloupe, and Curaçao. Because of the multi-allelic nature of the ITS region, four individuals from Lineage 1 and six from Lineage 2 were cloned to evaluate the levels of hidden intra-individual variability. Pairwise genetic comparisons indicated that the levels of intra-individual and intra-lineage variability (\u3c1%) were approximately an order of magnitude lower than the divergence (~9%) observed between the two lineages. The fishery regulations of the aquarium trade regard R. florida as one species. More refined regulations should take into account the presence of two genetic lineages, and they should be managed separately in order to preserve the long-term evolutionary potential of this corallimorpharian. The discovery of two distinct lineages in R. florida illustrates the importance of evaluating genetic variability in harvested species prior to the implementation of management policies

Caracterización de dos sistemas de abanicos aluviales húmedos en el Terciario de la Depresión Intermedia (Cuenca-Guadalajara)

En este trabajo se comparan las características de dos abanicos aluviales del Primer Ciclo Neógeno (Ageniense superior-Aragoniense inferior) de la Depresion Intermedia. Estos abanicos tienen una serie de características comunes como: área fuente en la Cordillera Ibérica, períodos alternantes de funcinamiento de canales de baja y alta sinuosidad e interdigitación distal con depósitos lacustres de yesos bioturbados. Se diferencian en la orientación de paleocorrientes y presencia en uno de ellos (Guadiela) de abundantes depósitos estromatolíticos, que indican períodos dilatados de funcionamiento sin corrientes tractivas

Two interacting atoms in a cavity: exact solutions, entanglement and decoherence

We address the problem of two interacting atoms of different species inside a cavity and find the explicit solutions of the corresponding eigenvalues and eigenfunctions using a new invariant. This model encompasses various commonly used models. By way of example we obtain closed expressions for concurrence and purity as a function of time for the case where the cavity is prepared in a number state. We discuss the behaviour of these quantities and and their relative behaviour in the concurrence-purity plane.Comment: 10 pages, 3 figure

Paleotopografía y distribución de paleocorrientes de abanicos aluviales de la Depresión Intermedia (Cuenca-Guadalajara)

La investigación sísmica y el análisis de cuenca de la Depresión Intermedia, han permitido determinar la estructuración del basamento y la distribución de sedimentos cenozoicos Han aparecido una serie de depresiones de  subsidencia elevada que condicionaron el desarrollo de los abanicos aluviales del Primer Ciclo Neógeno y parte de los del Segundo Ciclo Paleógeno. El sistema fluvial principal del Segundo Ciclo Paleógeno, funcinó adosado a la Sierra de Altomira, en un surco que fue desactivado durante la fase intraageniense de deformación, que separa el Segundo Ciclo Paleógeno y el Primer Ciclo Neógeno

Quantum Electrodynamics vacuum polarization solver

The self-consistent modeling of vacuum polarization due to virtual electron-positron fluctuations is of relevance for many near term experiments associated with high intensity radiation sources and represents a milestone in describing scenarios of extreme energy density. We present a generalized finite-difference time-domain solver that can incorporate the modifications to Maxwell's equations due to vacuum polarization. Our multidimensional solver reproduced in one dimensional configurations the results for which an analytic treatment is possible, yielding vacuum harmonic generation and birefringence. The solver has also been tested for two-dimensional scenarios where finite laser beam spot sizes must be taken into account. We employ this solver to explore different types of counter-propagating configurations that can be relevant for future planned experiments aiming to detect quantum vacuum dynamics at ultra-high electromagnetic field intensities

Evolución cenozoica de la Depresión Intermedia (Cuenca-Guadalajara)

En este trabajo se analiza la evolución Cenozoica de la Depresión Intermedia, habiéndose determinado la existencia de dos ciclos paleógenos y cuatro neógenos. En todos ellos la sedimentación es continental y de carácter fluvial y lacustre-palustre. Si se exceptúa el Primer Ciclo Paleógeno, que tuvo su área fuente en una zona al sur de la cuenca en la que predominaban rocas paleozoicas, los cinco restantes las tuvieron en el Sistema Ibérico, donde predominan rocas mesozoica

Detection of the old stellar component of the major Galactic bar

We present near-IR colour--magnitude diagrams and star counts for a number of regions along the Galactic plane. It is shown that along the l=27 b=0 line of sight there is a feature at 5.7 +-0.7kpc with a density of stars at least a factor two and probably more than a factor five times that of the disc at the same position. This feature forms a distinct clump on an H vs. J-H diagram and is seen at all longitudes from the bulge to about l=28, but at no longitude greater than this. The distance to the feature at l=20 is about 0.5kpc further than at l=27 and by l=10 it has merged with, or has become, the bulge. Given that at l=27 and l=21 there is also a clustering of very young stars, the only component that can reasonably explain what is seen is a bar with half length of around 4kpc and a position angle of about 43+-7.Comment: 5 pages, 5 figures accepted as a letter in MNRA