The Magnetic Field of the H~II Region NGC 6334A

We have studied the polarization characteristics and Faraday rotation of the extragalactic radio source J17204$-$3554, that appears projected on the north lobe of the galactic H II region NGC 6334A. From observations made with the Very Large Array at 6.0 and 3.6 cm in three different epochs (1994, 1997, and 2006), we estimate a rotation measure of +5100$\pm$900 rad m$^{-2}$ for the extragalactic source. This large rotation measure implies a line-of-sight average magnetic field of $B_\parallel \simeq +36\pm6$ $\mu$G, the largest obtained by this method for an H II region. NGC 6334A is significantly denser than other H II regions studied and this larger magnetic field is expected on the grounds of magnetic flux conservation. The ratio of thermal to magnetic pressure is $\sim$5, in the range of values determined for more diffuse H II regions.Comment: 5 pages, 0 figure

Draft genome of Haloarcula rubripromontorii strain SL3, a novel halophilic archaeon isolated from the solar salterns of Cabo Rojo, Puerto Rico.

The genus Haloarcula belongs to the family Halobacteriaceae which currently has 10 valid species. Here we report the draft genome sequence of strain SL3, a new species within this genus, isolated from the Solar Salterns of Cabo Rojo, Puerto Rico. Genome assembly performed using NGEN Assembler resulted in 18 contigs (N50 = 601,911 bp), the largest of which contains 1,023,775 bp. The genome consists of 3.97 MB and has a GC content of 61.97%. Like all species of Haloarcula, the genome encodes heterogeneous copies of the small subunit ribosomal RNA. In addition, the genome includes 6 rRNAs, 48 tRNAs, and 3797 protein coding sequences. Several carbohydrate-active enzymes genes were found, as well as enzymes involved in the dihydroxyacetone processing pathway which are not found in other Haloarcula species. The NCBI accession number for this genome is LIUF00000000 and the strain deposit number is CECT9001

Transformation pathways of cocrystal hydrates when coformer modulates water activity

An important attribute of cocrystals is that their properties can be tailored to meet required solubility and stability specifications. But before such practical uses can be realized, a better understanding of the factors that dictate co-crystal behavior is needed. This study attempts to explain the phase behavior of anhydrous/hydrated cocrystals when the coformer modulates both water activity and co-crystal solubility. Stability dependence on solution composition and water activity was studied for theophylline–citric acid (THP–CTA) anhydrous and hydrated cocrystals by both suspension and vapor equilibration methods. Eutectic points and associated water activities were measured by suspension equilibration methods to determine stability regions and phase diagrams. The critical water activity for the anhydrous–hydrate co-crystal was found to be 0.8. It is shown that (a) both water and coformer activities determine phase stability, and (b) excipients that alter water activity can profoundly affect the hydrate/anhydrous eutectic points and phase stability. Vapor phase stability studies demonstrate that cocrystals of highly water soluble coformers, such as citric acid, are predisposed to conversions due to moisture uptake and deliquescence of the coformer. The presence of such coformers as trace level impurities with co-crystal will alter hygroscopic behavior and stability. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:3977–3985, 2010Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77537/1/22245_ftp.pd

Chemistry teachers training from the explanation of everyday phenomena: a proposal with results

Este documento presenta los resultados de una experiencia con profesores en formación inicial del Proyecto Curricular de Licenciatura en Química de la Universidad Pedagógica Nacional, con quienes se desarrollaron unidades didácticas centradas en la explicación de fenómenos químicos cotidianos como estrategia para la formación de profesores de química, de las cuales se caracterizaron los niveles de representación químicos y la admisibilidad de las explicaciones construidas por los profesores en formación. Dicha iniciativa permitió consolidar un espacio que vinculó congruentemente aspectos disciplinares de la química con los de su didáctica, con el fin de aportar a sus integrantes recursos y metodologías para transformar las formas habituales de enseñanza, aprendizaje y evaluación de esta disciplina.This paper shows the research results obtained with a group of pre-service chemistry teachers at Universidad Pedagógica Nacional, employing didactic units focused in everyday chemistry as strategy for chemistry teaching. The explanations of pre-service chemistry teachers for the analyzed everyday chemical phenomena were characterized according to its admissibility and chemical levels of representation. The project allowed consolidating a space which employs coherently disciplinary and didactic aspects of chemistry, contributing to the pre-service teachers with resources and methodologies to transform the traditional forms of teaching, learning and evaluation of chemistry

Fermion- and spin-counting in strongly correlated systems in and out of thermal equilibrium

Atom counting theory can be used to study the role of thermal noise in quantum phase transitions and to monitor the dynamics of a quantum system. We illustrate this for a strongly correlated fermionic system, which is equivalent to an anisotropic quantum XY chain in a transverse field, and can be realized with cold fermionic atoms in an optical lattice. We analyze the counting statistics across the phase diagram in the presence of thermal fluctuations, and during its thermalization when the system is coupled to a heat bath. At zero temperature, the quantum phase transition is reflected in the cumulants of the counting distribution. We find that the signatures of the crossover remain visible at low temperature and are obscured with increasing thermal fluctuations. We find that the same quantities may be used to scan the dynamics during the thermalization of the system.Comment: 10 pages, 7 figure

Entanglement as geometry and flow

We explore the connection between the area law for entanglement and geometry by representing the entanglement entropies corresponding to all $2^N$ bipartitions of an $N$-party pure quantum system by means of a (generalized) adjacency matrix. In the cases where the representation is exact, the elements of that matrix coincide with the mutual information between pairs of sites. In others, it provides a very good approximation, and in all the cases it yields a natural {\em entanglement contour} which is similar to previous proposals.Moreover, for one-dimensional conformal invariant systems, the generalized adjacency matrix is given by the two-point correlator of an {\em entanglement current} operator. We conjecture how this entanglement current may give rise to a metric entirely built from entanglement.Comment: 13 pages, 11 figures, close to the published versio

PigReuse: A Reuse-based Optimizer for Pig Latin

Pig Latin is a popular language which is widely used for parallel processing of massive data sets. Currently, subexpressions occurring repeatedly in Pig Latin scripts are executed as many times as they appear, and the current Pig Latin optimizer does not identify reuse opportunities.We present a novel optimization approach aiming at identifying and reusing repeated subexpressions in Pig Latin scripts. Our optimization algorithm, named PigReuse, operates on a particular algebraic representation of Pig Latin scripts. PigReuse identifies subexpression merging opportunities, selects the best ones to execute based on a cost function, and reuses their results as needed in order to compute exactly the same output as the original scripts. Our experiments demonstrate the effectiveness of our approach

Modernas tendencias en el derecho penitenciario : las propuestas del "Derecho penitenciario mínimo", el "Derecho penitenciario del enemigo" y las reformas del 2003 en el ordenamiento jurídico-penitenciario español

Con la finalidad de realizar una primera aproximación al Derecho penitenciario español, pretendemos a través de este ejercicio académico, acercarnos a las propuestas de los profesores Luigi Ferrajoli y Günther Jakobs – desde lo que hemos denominado respectivamente, sus modelos de “Derecho penitenciario mínimo” y “Derecho penitenciario del enemigo”- por considerar que son dos posiciones modernas y reconocidas en la discusión académica, que en principio parecen llevar a direcciones opuestas. La pretensión es valorar la idoneidad de los referidos modelos y al mismo tiempo concluir sobre el estado actual, el rumbo y futuro del Derecho penitenciario español. Para cumplir el objetivo, se expondrán las nociones básicas que cada autor hace sobre el Derecho penitenciario y su caracterización particular, para finalmente realizar un análisis concreto de las instituciones actuales del Derecho penitenciario español –sobre todo el régimen progresivo y los beneficios penitenciarios- con el fin de evaluar si se presentan rasgos o manifestaciones del garantismo o del Derecho penal del enemigo, considerando sobremanera las últimas reformas legales en la materi