SUSTITUCIONES CATIÓNICAS QUE GOBIERNAN LA QUÍMICA DEL ANFÍBOL EN METABASITAS DE LA FORMACIÓN SILGARÁ EN LA REGIÓN SUROCCIDENTAL DEL MACIZO DE SANTANDER

  Las paragénesis con presencia de anfíbol de las rocas metabásicas de la Formación Silgará en la región suroccidental del Macizo de Santander registran evidencia de metamorfismo prógrado. Análisis ópticos y de microsonda electrónica, junto con cálculos termobarométricos en estas rocas, muestran que la principal variación en anfíboles cálcicos es la sustitución simultánea de Al en el sitio T1 (AlIV) y Na+K en el sitio A de la estructura cristalina del anfíbol. AlIV es fuertemente dependiente de la temperatura, y esta dependencia enmascara cualquier efecto de la presión. Los cambios en la composición química del anfíbol cálcico son interpretados a traves de sustituciones acopladas, y reacciones con los minerales con los cuales coexiste durante un aumento en las condiciones de metamorfismo desde la facies esquisto verde hasta la facies anfibolita inferior, siendo circunstancias favorables que registran no solo las facies metamórficas alcanzadas por las rocas sino tambien las condiciones de P-T por las cuales estas fueron obtenidas.   Palabras claves: anfíbol, Silgará, metabasitas, sustitución, condiciones de metamorfismo    Amphibole-bearing parageneses from the Silgará Formation metabasites at the southwestern Santander Massif record evidence of prograding metamorphism. Optical and microprobe analyses, together with thermobarometric estimates on these rocks, show that the main variation in Ca-amphibole is the simultaneous substitution of Al into the T1 site (AlIV) and Na+K into the A-site of the amphibole’s crystal structure. AlIV is strongly temperature dependant, and this dependancy masks any pressure effect. Changes in the chemical composition of Ca-amphibole grains are interpreted through coupled substitutions, and reactions with co-existing minerals during an increase in metamorphic conditions from greenschist to lower amphibolite facies, being favourable circumstances record not only the metamorphic facies reached by rocks but also the P-T conditions by which these were attained.   Keywords: amphibole, Silgará, metabasites, substitution, metamorphic conditions   &nbsp

SUSTITUCIONES CATIÓNICAS QUE GOBIERNAN LA QUÍMICA DEL ANFÍBOL EN METABASITAS DE LA FORMACIÓN SILGARÁ EN LA REGIÓN SUROCCIDENTAL DEL MACIZO DE SANTANDER

  Las paragénesis con presencia de anfíbol de las rocas metabásicas de la Formación Silgará en la región suroccidental del Macizo de Santander registran evidencia de metamorfismo prógrado. Análisis ópticos y de microsonda electrónica, junto con cálculos termobarométricos en estas rocas, muestran que la principal variación en anfíboles cálcicos es la sustitución simultánea de Al en el sitio T1 (AlIV) y Na+K en el sitio A de la estructura cristalina del anfíbol. AlIV es fuertemente dependiente de la temperatura, y esta dependencia enmascara cualquier efecto de la presión. Los cambios en la composición química del anfíbol cálcico son interpretados a traves de sustituciones acopladas, y reacciones con los minerales con los cuales coexiste durante un aumento en las condiciones de metamorfismo desde la facies esquisto verde hasta la facies anfibolita inferior, siendo circunstancias favorables que registran no solo las facies metamórficas alcanzadas por las rocas sino tambien las condiciones de P-T por las cuales estas fueron obtenidas.   Palabras claves: anfíbol, Silgará, metabasitas, sustitución, condiciones de metamorfismo    Amphibole-bearing parageneses from the Silgará Formation metabasites at the southwestern Santander Massif record evidence of prograding metamorphism. Optical and microprobe analyses, together with thermobarometric estimates on these rocks, show that the main variation in Ca-amphibole is the simultaneous substitution of Al into the T1 site (AlIV) and Na+K into the A-site of the amphibole’s crystal structure. AlIV is strongly temperature dependant, and this dependancy masks any pressure effect. Changes in the chemical composition of Ca-amphibole grains are interpreted through coupled substitutions, and reactions with co-existing minerals during an increase in metamorphic conditions from greenschist to lower amphibolite facies, being favourable circumstances record not only the metamorphic facies reached by rocks but also the P-T conditions by which these were attained.   Keywords: amphibole, Silgará, metabasites, substitution, metamorphic conditions   &nbsp

METAMORFISMO DE PRESION INTERMEDIA EN LA REGION CENTRAL DEL MACIZO DE SANTANDER, CORDILLERA ORIENTAL, ANDES COLOMBIANOS

  The Central Santander Massif exposes its metamorphic basement, which mainly consists of medium- to high-grade pelitic schists, paragneisses, migmatites and orthogneisses. For delineating its metamorphic evolution, we have examinated mineral assemblages, metamorphic reactions and P-T conditions of metamorphic rocks of this region. Metamorphism has occurred under conditions of high-temperature and medium-pressure (Barrovian type metamorphism), and three metamorphic zones were developed: staurolite-kyanite, sillimanite and migmatite zones. Pressure and temperatura conditions, estimated by TWQ program, are in the range of 5.0-9.5 kbar and 630-727oC. The P-T path of the metamorphic units is clockwise suggesting a collision model for this region of the Colombian Andes.   Keywords: Metamorphism; Santander Massif; Barrovian type; P-T path; collision            La región central del Macizo de Santander expone su basamento metamórfico, el cual consiste de esquistos pelíticos, paraneises, migmatitas y ortoneises de medio a alto grado. Para delinear su evolución metamórfica, hemos examinado las paragénesis minerales, reacciones metamórficas y condiciones de P-T de las rocas metamórficas de esta región. El metamorfismo ocurrió bajo condiciones de alta temperatura y presión intermedia (metamorfismo tipo Barroviano), con el desarrollo de tres zonas metamórficas: estaurolita-cianita, silimanita y migmatita. Las condiciones de presión y temperatura, estimadas mediante el programa TWQ, están en el rango de 5.0-9.5 kbar y 630-727oC. La trayectoria de PT de las unidades metamórficas es en sentido horario sugiriendo un modelo de colisión para esta región de los Andes Colombianos.   Palabras claves: Metamorfismo; Macizo de Santander; tipo Barroviano; trayectoria de P-T; colisión

METAMORFISMO DE PRESION INTERMEDIA EN LA REGION CENTRAL DEL MACIZO DE SANTANDER, CORDILLERA ORIENTAL, ANDES COLOMBIANOS

  The Central Santander Massif exposes its metamorphic basement, which mainly consists of medium- to high-grade pelitic schists, paragneisses, migmatites and orthogneisses. For delineating its metamorphic evolution, we have examinated mineral assemblages, metamorphic reactions and P-T conditions of metamorphic rocks of this region. Metamorphism has occurred under conditions of high-temperature and medium-pressure (Barrovian type metamorphism), and three metamorphic zones were developed: staurolite-kyanite, sillimanite and migmatite zones. Pressure and temperatura conditions, estimated by TWQ program, are in the range of 5.0-9.5 kbar and 630-727oC. The P-T path of the metamorphic units is clockwise suggesting a collision model for this region of the Colombian Andes.   Keywords: Metamorphism; Santander Massif; Barrovian type; P-T path; collision            La región central del Macizo de Santander expone su basamento metamórfico, el cual consiste de esquistos pelíticos, paraneises, migmatitas y ortoneises de medio a alto grado. Para delinear su evolución metamórfica, hemos examinado las paragénesis minerales, reacciones metamórficas y condiciones de P-T de las rocas metamórficas de esta región. El metamorfismo ocurrió bajo condiciones de alta temperatura y presión intermedia (metamorfismo tipo Barroviano), con el desarrollo de tres zonas metamórficas: estaurolita-cianita, silimanita y migmatita. Las condiciones de presión y temperatura, estimadas mediante el programa TWQ, están en el rango de 5.0-9.5 kbar y 630-727oC. La trayectoria de PT de las unidades metamórficas es en sentido horario sugiriendo un modelo de colisión para esta región de los Andes Colombianos.   Palabras claves: Metamorfismo; Macizo de Santander; tipo Barroviano; trayectoria de P-T; colisión

Monte carlo simulation strategies for predicting CO 2/CH 4 adsorption onto activated carbons from pure gas isotherms

The problem of predicting the adsorptive properties of activated carbon (AC) towards a mixture of gases from the simple knowledge of the adsorption properties of the pure components is addressed, with special reference to the CO2/CH4 mixture. The adsorption process for the pure gases and their mixtures was simulated using the Grand Canonical Monte Carlo (GCMC) method and the calculations were then used to analyze experimental isotherms for the pure gases and for mixtures with different molar fractions in the gaseous phase. It was shown that the pore-size distributions (PSDs) “sensed” by each of the pure probe gases was different one from the other and also from the PSDs “seen” by the mixture. A mixing rule for combining the PSDs corresponding to the pure gases is proposed for obtaining predictions regarding the adsorption of the corresponding mixtures, which are then compared with those arising from the classical IAST approximation. For this purpose, selectivity curves for CO2 relative to CH4 have been calculated and compared with experimental values. It was concluded that, for the adsorbate/adsorbent system under study, the proposed GCMC mixed model was capable of predicting the binary adsorption equilibrium, and especially the selectivity, more accurately than the IAST.Fil: de Oliveira, José C. A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Física Aplicada; Argentina. Universidad Nacional de San Luis; ArgentinaFil: Rios, Rafael B.. Universidade Federal do Ceará; BrasilFil: López, Raúl Horacio. Universidad Nacional de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Física Aplicada; ArgentinaFil: Peixoto, Hugo R.. Universidade Federal do Ceará; BrasilFil: Cornette, Valeria Cecilia. Universidad Nacional de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Física Aplicada; ArgentinaFil: Torres, A. Eurico B.. Universidade Federal do Ceará; BrasilFil: Calvalcante Jr., Célio L.. Universidade Federal do Ceará; BrasilFil: Zgrablich, Jorge Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Física Aplicada; Argentina. Universidad Nacional de San Luis; Argentin

Naturally Derived Heme-Oxygenase 1 Inducers and Their Therapeutic Application to Immune-Mediated Diseases

Indexación: Scopus.Heme oxygenase (HO) is the primary antioxidant enzyme involved in heme group degradation. A variety of stimuli triggers the expression of the inducible HO-1 isoform, which is modulated by its substrate and cellular stressors. A major anti-inflammatory role has been assigned to the HO-1 activity. Therefore, in recent years HO-1 induction has been employed as an approach to treating several disorders displaying some immune alterations components, such as exacerbated inflammation or self-reactivity. Many natural compounds have shown to be effective inductors of HO-1 without cytotoxic effects; among them, most are chemicals present in plants used as food, flavoring, and medicine. Here we discuss some naturally derived compounds involved in HO-1 induction, their impact in the immune response modulation, and the beneficial effect in diverse autoimmune disorders. We conclude that the use of some compounds from natural sources able to induce HO-1 is an attractive lifestyle toward promoting human health. This review opens a new outlook on the investigation of naturally derived HO-1 inducers, mainly concerning autoimmunity. © Copyright © 2020 Funes, Rios, Fernández-Fierro, Covián, Bueno, Riedel, Mackern-Oberti and Kalergis.https://www.frontiersin.org/articles/10.3389/fimmu.2020.01467/ful

Tree method for quantum vortex dynamics

We present a numerical method to compute the evolution of vortex filaments in superfluid helium. The method is based on a tree algorithm which considerably speeds up the calculation of Biot-Savart integrals. We show that the computational cost scales as Nlog{(N) rather than N squared, where $N$ is the number of discretization points. We test the method and its properties for a variety of vortex configurations, ranging from simple vortex rings to a counterflow vortex tangle, and compare results against the Local Induction Approximation and the exact Biot-Savart law.Comment: 12 pages, 10 figure

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio