Multiwavelength optical observations of chromospherically active binary systems V. FF UMa (2RE J0933+624): a system with orbital period variation

This is the fifth paper in a series aimed at studying the chromospheres of active binary systems using several optical spectroscopic indicators to obtain or improve orbital solution and fundamental stellar parameters. We present here the study of FF UMa (2RE J0933+624), a recently discovered, X-ray/EUV selected, active binary with strong H_alpha emission. The objectives of this work are, to find orbital solutions and define stellar parameters from precise radial velocities and carry out an extensive study of the optical indicators of chromospheric activity. We obtained high resolution echelle spectroscopic observations during five observing runs from 1998 to 2004. We found radial velocities by cross correlation with radial velocity standard stars to achieve the best orbital solution. We also measured rotational velocity by cross-correlation techniques and have studied the kinematic by galactic space- velocity components (U, V, W) and Eggen criteria. Finally, we have determined the chromospheric contribution in optical spectroscopic indicators, from Ca II H & K to Ca II IRT lines, using the spectral subtraction technique. We have found that this system presents an orbital period variation, higher than previously detected in other RS CVn systems. We determined an improved orbital solution, finding a circular orbit with a period of 3.274 days. We derived the stellar parameters, confirming the subgiant nature of the primary component and obtained rotational velocities (vsini), of 33.57 km/s and 32.38 km/s for the primary and secondary components respectively. From our kinematic study, we can deduce its membership to the Castor moving group. Finally, the activity study has given us a better understanding of the possible mechanisms that produce the orbital period variation.Comment: Latex file with 16 pages, 18 figures. Available at http://www.ucm.es/info/Astrof/invest/actividad/actividad_pub.html Accepted for publication in: Astronomy & Astrophysics (A&A

Lesiones y problemas físicos padecidos por senderistas y cicloturistas en una ruta por etapas: el caso del Camino de Santiago

Este trabajo ha tenido por objetivo conocer los problemas físicos, dolencias o enfermedades padecidas por el peregrino mayor de 15 años que recorre el Camino de Santiago, andando o en bicicleta, analizando las diferencias producidas en función de la edad, sexo, medio de locomoción y nacionalidad. La investigación se ha desarrollado mediante la aplicación de un cuestionario autoadministrado en Compostela a una muestra de 1.091 sujetos, utilizando el procedimiento de muestreo estratificado polietápico con afijación proporcional, con un margen de error muestral del ±3 % y un nivel de confianza del 95,5%. Los resultados indicaron que el medio utilizado para realizar una ruta por etapas, y la distancia recorrida, son determinantes de los problemas físicos sufridos, comprobándose que las ampollas y las llagas en los pies, así como la tendinitis, las padecen más los senderistas, mientras que a los cicloturistas afectan más las insolaciones, resfriados y caídas y golpes

A review of a priori defined oxidative balance scores relative to their components and impact on health outcomes

Oxidative Balance Scores (OBSs) are tools that have emerged to evaluate the global balance of individuals’ oxidation—reduction status. The aim was to compare OBSs available in the literature regarding their characteristics and associations with chronic diseases in epidemiological studies. Studies that developed OBSs were searched in PubMed until August 2018. A total of 21 OBSs were identified. These OBSs presented different scoring schemes and different types of anti- and pro-oxidant components, including dietary factors (dietary intake and/or nutrient biomarkers), lifestyle factors, and medications. Most OBSs were based on over 10 components, and some included only dietary factors. Few considered weighted components in the score. Only three OBSs were validated as potential surrogates of oxidative balance through inflammation and OS-related biomarkers. Notably, all the OBSs were associated—to a varying degree—with a reduced risk of cardiovascular diseases, chronic kidney disease, colorectal adenomas, and different cancer types (colorectal and breast cancer), as well as with all-cause and cancer-related mortality. For other outcomes, e.g., prostate cancer, contradictory results were reported. In summary, there is a great heterogeneity in the definition of OBSs. Most studies are concordant in supporting that excessive OS reflected by a lower OBS has deleterious effects on health. Unified criteria for defining the proper OBSs, valuable to gauge OS-related aspects of the diet and lifestyle that may lead to adverse health outcomes, are needed

Adaptive applications to assist students with autism in succeeding in higher education

Abstract. In this demo we discuss a few possible scenarios showing adaptation of presentation and information to assist autistic students in succeeding in higher education. These students not only have specific information need, they are also more concerned about their privacy. We use WiBAF (Within Browser Adaptation Framework) for user modeling and adaptation to give users control over the sharing of their data

Microwave background anisotropies in quasiopen inflation

Quasiopenness seems to be generic to multi-field models of single-bubble open inflation. Instead of producing infinite open universes, these models actually produce an ensemble of very large but finite inflating islands. In this paper we study the possible constraints from CMB anisotropies on existing models of open inflation. The effect of supercurvature anisotropies combined with the quasiopenness of the inflating regions make some models incompatible with observations, and severely reduces the parameter space of others. Supernatural open inflation and the uncoupled two-field model seem to be ruled out due to these constraints for values of $\Omega_0\lesssim0.98$. Others, such as the open hybrid inflation model with suitable parameters for the slow roll potential can be made compatible with observations.Comment: 19 pages, ReVTeX, 10 figures inserted with eps

The young active star SAO 51891 (V383 Lac)

Our aim is investigating surface inhomogeneities of the young late-type star SAO51891, from photosphere to upper chromosphere, analyzing contemporaneous high-resolution spectra and broad-band photometry. The FOCES@CAHA spectral range is used to determine spectral classification and derive vsini and Vrad. The Li abundance is measured to estimate the age. The BVRIJHKs bands are used to construct the SED. The variations of our BV fluxes and Teff are used to infer the presence of photospheric spots and observe their behavior over time. The chromospheric activity is studied applying the spectral subtraction technique to Halpha, CaII H&K, Heps, and CaII IRT lines. We find SAO51891 to be a young K0-1V star with Li abundance close to the Pleiades upper envelope, confirming its youth (~100 Myr), also inferred from its kinematical membership to the Local Association. We detect no IR excess from SED analysis, and rotational modulation of luminosity, Teff, CaII, and Heps total fluxes. A spot model with two active regions, ~240 K cooler than the surrounding photosphere, fits our light/Teff curves, and reproduces the small-amplitude Vrad variations. The anti-correlation of light curves and chromospheric diagnostics indicates plages spatially associated with spots. The large amplitude observed in the Heps-flux curve suggests that this line is very sensitive to the plage presence. Finally, SAO51891 is a young active star, lacking significant amounts of circumstellar dust or any evidence for low mass companions. The spots turn out to be larger and warmer than those in less active MS stars. The Vrad variation produced by spots has an amplitude comparable with those induced by Jupiter-mass planets orbiting close to the star. SAO51891 is a good example of star where the detection of planets may be hampered by the high activity level.Comment: 16 pages, 12 figures, 7 tables, accepted by Astronomy and Astrophysics; abstract here was shortene

Soluble iron inputs to the Southern Ocean through recent andesitic to rhyolitic volcanic ash eruptions from the Patagonian Andes

Patagonia, due to its geographic position and the dominance of westerly winds, is a key area that contributes to the supply of nutrients to the Southern Ocean, both through mineral dust and through the periodic deposits of volcanic ash. Here we evaluate the characteristics of Fe dissolved (into soluble and colloidal species) from volcanic ash for three recent southern Andes volcanic eruptions having contrasting features and chemical compositions. Contact between cloud waters (wet deposition) and end-members of andesitic (Hudson volcano) and rhyolitic (Chaitén volcano) materials was simulated. Results indicate higher Fe release and faster liberation rates in the andesitic material. Fe release during particle-seawater interaction (dry deposition) has higher rates in rhyolitic-type ashes. Rhyolitic ashes under acidic conditions release Fe in higher amounts and at a slower rate, while in those samples containing mostly glass shards, Fe release was lower and faster. The 2011 Puyehue eruption was observed by a dust monitoring station. Puyehue-type eruptions can contribute soluble Fe to the ocean via dry or wet deposition, nearly reaching the limit required for phytoplankton growth. In contrast, the input of Fe after processing by an acidic eruption plume could raise the amount of dissolved Fe in surface ocean waters several times, above the threshold required to initiate phytoplankton blooms. A single eruption like the Puyehue one represents more than half of the yearly Fe flux contributed by dust.Instituto de Física La Plat

Síntesis y caracterización de nanocompuestos montmorillonitacarbones hidrotérmicos y su aplicación en la sorción de pesticidas

El carbón activado ha sido ampliamente utilizado para remover contaminantes debido a su elevada porosidad, carga eléctrica superficial y presencia de grupos funcionales específicos1. Sin embargo, su coste de producción es relativamente elevado, y su síntesis involucra un proceso complejo. Los carbones hidrotérmicos (HTC), obtenidos a partir de biomasa, implican una síntesis más sencilla y bajas temperaturas2, postulándose así como materiales alternativos al carbón activado. La montmorillonita (M) es una arcilla de bajo coste, gran capacidad de intercambio catiónico y superficie, lo que le otorga buenas características como soporte de los HTC y/o adsorbente3. El objetivo de este trabajo es estudiar la síntesis de diferentes nanocompuestos de HTC soportados sobre M, para su posterior uso en adsorción de pesticidas, en particular tiabendazol (TBZ) y clorpirifós (CPF), ambos muy utilizados en Argentina para la protección de frutas. Para la obtención de los nanocompuestos se utilizaron suspensiones de M con distintas concentraciones de hidratos de carbono como precursores de HTC (dextrosa (D), sacarosa (S), celulosa (C), almidón soluble (AS) o almidón de maíz (AM)). Las suspensiones se trataron en autoclave a 180 o 210 ºC durante 16 o 24 h, dependiendo de la muestra. También se realizaron síntesis en presencia de distintas concentraciones de ácido fosfórico (0,16 (ac1) y 0,33 (ac2) %V/V) como agente activante y se sintetizaron HTC sin M a 210 ºC durante 24 h. Los nanocompuestos obtenidos se caracterizaron mediante adsorción de N2, difracción de rayos X, espectroscopía infrarroja con reflectancia difusa y potencial zeta. Finalmente se realizaron estudios de sorción de TBZ y CPF sobre algunos de los materiales sintetizados. En la mayoría de los casos analizados, se obtuvieron porcentajes de sorción de alrededor del 99% para ambos pesticidas, aunque en el caso de CPF las muestras presentaron más variación que para TBZ.Facultad de Ciencias ExactasCentro de Tecnología de Recursos Minerales y Cerámic

Síntesis y caracterización de nanocompuestos montmorillonitacarbones hidrotérmicos y su aplicación en la sorción de pesticidas

El carbón activado ha sido ampliamente utilizado para remover contaminantes debido a su elevada porosidad, carga eléctrica superficial y presencia de grupos funcionales específicos1. Sin embargo, su coste de producción es relativamente elevado, y su síntesis involucra un proceso complejo. Los carbones hidrotérmicos (HTC), obtenidos a partir de biomasa, implican una síntesis más sencilla y bajas temperaturas2, postulándose así como materiales alternativos al carbón activado. La montmorillonita (M) es una arcilla de bajo coste, gran capacidad de intercambio catiónico y superficie, lo que le otorga buenas características como soporte de los HTC y/o adsorbente3. El objetivo de este trabajo es estudiar la síntesis de diferentes nanocompuestos de HTC soportados sobre M, para su posterior uso en adsorción de pesticidas, en particular tiabendazol (TBZ) y clorpirifós (CPF), ambos muy utilizados en Argentina para la protección de frutas. Para la obtención de los nanocompuestos se utilizaron suspensiones de M con distintas concentraciones de hidratos de carbono como precursores de HTC (dextrosa (D), sacarosa (S), celulosa (C), almidón soluble (AS) o almidón de maíz (AM)). Las suspensiones se trataron en autoclave a 180 o 210 ºC durante 16 o 24 h, dependiendo de la muestra. También se realizaron síntesis en presencia de distintas concentraciones de ácido fosfórico (0,16 (ac1) y 0,33 (ac2) %V/V) como agente activante y se sintetizaron HTC sin M a 210 ºC durante 24 h. Los nanocompuestos obtenidos se caracterizaron mediante adsorción de N2, difracción de rayos X, espectroscopía infrarroja con reflectancia difusa y potencial zeta. Finalmente se realizaron estudios de sorción de TBZ y CPF sobre algunos de los materiales sintetizados. En la mayoría de los casos analizados, se obtuvieron porcentajes de sorción de alrededor del 99% para ambos pesticidas, aunque en el caso de CPF las muestras presentaron más variación que para TBZ.Facultad de Ciencias ExactasCentro de Tecnología de Recursos Minerales y Cerámic