Theoretical Kinetics Study of the F(2P) + NH3 Hydrogen Abstraction Reaction

The hydrogen abstraction reaction of fluorine with ammonia represents a true chemical challenge because it is very fast, is followed by secondary abstraction reactions, which are also extremely fast, and presents an experimental/theoretical controversy about rate coefficients. Using a previously developed full-dimensional analytical potential energy surface, we found that the F + NH3 → HF + NH2 system is a barrierless reaction with intermediate complexes in the entry and exit channels. In order to understand the reactivity of the title reaction, thermal rate coefficidents were calculated using two approaches: ring polymer molecular dynamics and quasi-classical trajectory calculations, and these were compared with available experimental data for the common temperature range 276–327 K. The theoretical results obtained show behavior practically independent of temperature, reproducing Walther–Wagner’s experiment, but in contrast with Persky’s more recent experiment. However, quantitatively, our results are 1 order of magnitude larger than those of Walther–Wagner and reasonably agree with the Persky at the lowest temperature, questioning so Walther−Wagner’s older data. At present, the reason for this discrepancy is not clear, although we point out some possible reasons in the light of current theoretical calculationsThis work was partially supported by Gobierno de Extremadura, Spain, and FEDER (Project No. IB10001). Y.V.S. acknowledges the support of a Combustion Energy Research Fellowship through the Combustion Energy Frontier Research Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Basic Energy Sciences under Award Number DE-SC0001198. A.F-.R. thanks Xunta de Galicia through Grant No. 2012/314 para a consolidación e a estruturación de unidades de investigación competitivas do Sistema Universitario de Galicia, 2012S

Uso sustentable de los recursos naturales de la reserva ecológica del Tentzo en el municipio de San Juan Atzompa, Puebla

El municipio de San Juan Atzompa se encuentra ubicado dentro de la zona de la reserva estatal Sierra del Tentzo la cual fue declarada área natural protegida, con 57 mil 815 hectáreas en 13 municipios del estado de Puebla, dicha reserva alberga un gran número de especies animales y vegetales, endémicas y de importancia económica para sus habitantes; de ahí la importancia del aprovechamiento de los recursos naturales de manera sustentable mediante la propuesta de un servicio de ecoturismo el cual sea proporcionado por los habitantes del municipio de San Juan Atzompa y sirva de apoyo en la preservación del  valor biológico, social, cultural y económico de la zona

Octupole correlations in light actinides from the interacting boson model based on the Gogny energy density functional

The quadrupole-octupole coupling and the related spectroscopic properties have been studied for the even-even light actinides $^{218-238}$Ra and $^{220-240}$Th. The Hartree-Fock-Bogoliubov approximation, based on the Gogny-D1M energy density functional, has been employed as a microscopic input, i.e., to obtain (axially symmetric) mean-field potential energy surfaces as functions of the quadrupole and octupole deformation parameters. The mean-field potential energy surfaces have been mapped onto the corresponding bosonic potential energy surfaces using the expectation value of the $sdf$ Interacting Boson Model (IBM) Hamiltonian in the boson condensate state. The strength parameters of the $sdf$-IBM Hamiltonian have been determined via this mapping procedure. The diagonalization of the mapped IBM Hamiltonian provides energies for positive- and negative-parity states as well as wave functions which are employed to obtain transitional strengths. The results of the calculations compare well with available data from Coulomb excitation experiments and point towards a pronounced octupole collectivity around $^{224}$Ra and $^{226}$Th.Comment: 15 pages, 10 figures, 1 tabl

New results on q-positivity

In this paper we discuss symmetrically self-dual spaces, which are simply real vector spaces with a symmetric bilinear form. Certain subsets of the space will be called q-positive, where q is the quadratic form induced by the original bilinear form. The notion of q-positivity generalizes the classical notion of the monotonicity of a subset of a product of a Banach space and its dual. Maximal q-positivity then generalizes maximal monotonicity. We discuss concepts generalizing the representations of monotone sets by convex functions, as well as the number of maximally q-positive extensions of a q-positive set. We also discuss symmetrically self-dual Banach spaces, in which we add a Banach space structure, giving new characterizations of maximal q-positivity. The paper finishes with two new examples.Comment: 18 page

Low X-Ray Luminosity Galaxy Clusters: Main goals, sample selection, photometric and spectroscopic observations

We present the study of nineteen low X-ray luminosity galaxy clusters (L$_X \sim$ 0.5--45 $\times$ $10^{43}$ erg s$^{-1}$), selected from the ROSAT Position Sensitive Proportional Counters (PSPC) Pointed Observations (Vikhlinin et al. 1998) and the revised version of Mullis et al. (2003) in the redshift range of 0.16 to 0.7. This is the introductory paper of a series presenting the sample selection, photometric and spectroscopic observations and data reduction. Photometric data in different passbands were taken for eight galaxy clusters at Las Campanas Observatory; three clusters at Cerro Tololo Interamerican Observatory; and eight clusters at the Gemini Observatory. Spectroscopic data were collected for only four galaxy clusters using Gemini telescopes. With the photometry, the galaxies were defined based on the star-galaxy separation taking into account photometric parameters. For each galaxy cluster, the catalogues contain the PSF and aperture magnitudes of galaxies within the 90\% completeness limit. They are used together with structural parameters to study the galaxy morphology and to estimate photometric redshifts. With the spectroscopy, the derived galaxy velocity dispersion of our clusters ranged from 507 km~s$^{-1}$ for [VMF98]022 to 775 km~s$^{-1}$ for [VMF98]097 with signs of substructure. Cluster membership has been extensively discussed taking into account spectroscopic and photometric redshift estimates. In this sense, members are the galaxies within a projected radius of 0.75 Mpc from the X-ray mission peak and with cluster centric velocities smaller than the cluster velocity dispersion or 6000 km~s$^{-1}$, respectively. These results will be used in forthcoming papers to study, among the main topics, the red cluster sequence, blue cloud and green populations; the galaxy luminosity function and cluster dynamics.Comment: 13 pages, 6 tables, 9 figures. Uses emulateapj. Accepted for publication in The Astronomical Journal. Some formatting errors fixe

Formación de excelencia y competencia digital: El caso de la mención de pedagogía terapéutica de la UCLM

La atención a la diversidad es sin duda uno de los aspectos más “jóvenes” en el ámbito educativo y más necesario, ya que a través de ella el sistema se vértebra con el fin de poder cubrir las necesidades de un sector de la población cada vez más creciente. Por ello, debemos tomar conciencia de lo importante que es dotar la atención a la diversidad, en sus múltiples facetas, de recursos formativos de calidad. En este trabajo realizamos un análisis del currículo del grado de Educación primaria con mención en Pedagogía terapéutica de la UCLM con el fin de determinar en qué nivel están integradas y adaptadas las competencias digitales recogidas por el INTEF desde el Ministerio de Educación, Cultura y Deporte. Las conclusiones no son nada halagüeñas, ya que la integración de las competencias digitales es muy pequeña, por no decir insignificante. Esto nos lleva a plantearnos la labor de la ANECA y la calidad de los títulos que acredita. ¿Es aceptable una formación superior sin unas competencias digitales solidadas en el s. XXI

Nonlinear Bloch modes, optical switching and Bragg solitons in tightly coupled micro-ring resonator chains

We study nonlinear wave phenomena in coupled ring resonator optical waveguides in the tight coupling regime. A discrete model for the system dynamics is put forward and its steady state nonlinear Bloch modes are derived. The switching behavior of the transmission system is addressed numerically and the results are explained in the light of this analytical result. We also present a numerical study on the spontaneous generation of Bragg solitons from a continuous-wave input.Comment: Final versio

Alteraciones metabólicas secundarias al tratamiento con inhibidores de proteasa en pacientes infectados por el Virus de la Inmunodeficiencia Humana.

INTRODUCCIÓN: Los niños infectados por el VIH son más susceptibles de sufrir los efectos adversos del tratamiento, particularmente de los inhibidores de proteasa, debido al mecanismo de transmisión y las numerosas exposiciones a diferentes esquemas desde su nacimiento. OBJETIVOS: Determinar los efectos metabólicos a corto y a medio plazo del tratamiento con terapia antiretroviral altamente activa (TARAA), causados principalmente por los Inhibidores de proteasa (IP) en los pacientes pediátricos VIH seguidos de manera ambulatoria por unidades especializadas. METODOLOGÍA: Estudio descriptivo y analítico, retrospectivo y transversal, en el que se incluyen pacientes infectados por VIH, sin condicionantes de SIDA y bajo tratamiento antirretroviral combinado, seguidos en consultas de Infectología Pediátrica del Hospital Infantil Universitario Miguel Servet de Zaragoza, vistos en consulta desde el período de febrero de 2017 hasta julio de 2018. RESULTADOS: El 66,7% de los niños tratados con IP en el momento actual presenta cifras de colesterol, LDL y triglicéridos por encima de los valores de normalidad frente al 20%, 6.7% y 6.7% respectivamente, de los niños tratados sin IP. La disminución de cifras de colesterol, LDL y triglicéridos obtenida en analíticas durante y tras el tratamiento con IP en un mismo paciente, ha resultado estadísticamente significativa (p<0,05). La superioridad de cifras de colesterol, LDL y triglicéridos obtenida en analíticas de pacientes tratados con IP frente a valores obtenidos de pacientes tratados sin IP, ha resultado estadísticamente significativa (p<0,05). CONCLUSIONES: Es complicado atribuir a cada fármaco su correspondiente implicación en las diferentes alteraciones metabólicas. Sin embargo, de forma general podría decirse que los IP son los principales responsables de la dislipemia objetivada en sangre.<br /