The Sun as a Star: 13 years of SoHO

The best known Solar oscillation-like star is the Sun. During the last 14 years, the ESA/NASA Solar and Heliospheric Observatory (SoHO) has been continuously observing this star from the Lagrange point L1 with an enormous success. Among the 11 instruments placed onboard, 3 of them are dedicated to helioseismology: GOLF, VIRGO and MDI. The first two observe the Sun as a star by integrating the velocity or intensity signal of the visible solar disk into a single point. They are thus similar to any other observation done in asteroseismology. During this review I will present the most important results obtained during the mission concerning the Sun seen as a star and how this results have evolved our thoughts of the inside of our star.Comment: Proceedings of the Stellar Pulsation Conference. Santa Fe. 6 pages, 4 figure

Evidence of increasing acoustic emissivity at high frequency with solar cycle 23 in Sun-as-a-star observations

We used long high-quality unresolved (Sun-as-a-star observations) data collected by GOLF and VIRGO instruments on board the ESA/NASA SOHO satellite to investigate the amplitude variation with solar cycle 23 in the high-frequency band (5.7 < nu< 6.3 mHz). We found an enhancement of acoustic emissivity over the ascending phase of about 18+-3 in velocity observations and a slight enhancement of 3+-2 in intensity. Mode conversion from fast acoustic to fast magneto-acoustic waves could explain the enhancement in velocity observations. These findings open up the possibility to apply the same technique to stellar intensity data, in order to investigate stellar-magnetic activity.Comment: Proceedings of the Stellar Pulsation. Santa Fe, USA. 3 pages, 5 figure

Precise determination of the sigma pole location from a dispersive analysis

We review how the use of recent precise data on kaon decays together with forward dispersion relations (FDR) and Roy's equations allow us to determine the sigma resonance pole position very precisely, by using only experimental input. In addition, we present preliminary results for a modified set of Roy-like equations with only one subtraction, that show a remarkable improvement in the precision around the sigma resonance region. For practical applications, these results are shown to be very well approximated by a very simple conformal expansion.Comment: 5 pages, 2 figures. To appear in the proceedings of the Workshop on Scalar Mesons and Related Topics, Lisbon, Portugal, 11-16 Feb 200

Evaluación de la estrategia “educadores de pares” para prevención de infecciones de transmisión sexual y VIH entre escolares de Sullana y Ayabaca

Las infecciones de transmisión sexual y la epidemia producida por el virus de inmunodeficiencia humana (VIH), causante del síndrome de inmunodeficiencia adquirida (SIDA), se extiende inexorable e indeteniblemente hacia todos los rincones del mundo y constituye un gran reto para la supervivencia de la humanidad. Una estrategia implementada para controlar y prevenir esta epidemia es la de “educadores pares” para la población vulnerable (hombres que tienen sexo con hombres y trabajadoras sexuales). Es una estrategia efectiva para la prevención de VIH en población de elevada prevalencia, sin embargo, no existe una evaluación de esta estrategia en grupos de orientadores pares de adolescentes y jóvenes. La problemática que envuelve a las ITS y al VIH/SIDA demanda la articulación de los agentes que trabajan e inciden en la prevención, acción y propagación de los mismos. Es un problema de salud pública, ya que las conductas de riesgo en adolescentes y jóvenes incrementan la posibilidad de ITS y de contagio con el VIH/SIDA, manteniendo y propiciando el desarrollo de la epidemia con secuelas de morbilidad y mortalidad, consume recursos públicos ya que las personas infectadas demandan y requieren de diagnóstico, tratamiento paliativo y prevención secundaria haciendo que el Estado deje de lado otras prioridades. Afecta el bienestar social y familiar debido a la destrucción de los proyectos de vida personales y familiares

Actividad molusquicida de extractos acuosos vegetales sobre el caracol manzana pomacea canaliculata

En el Ecuador, entre el 40 y 48% de la producción de arroz se pierde a causa del ataque de Pomacea canaliculata, una de las cien especies invasivas más dañinas del mundo que actualmente ha infestado alrededor de 170.000 hectáreas del cultivo en todo el territorio nacional

Three-dimensional flow structure and bed morphology in large elongate meander loops with different outer bank roughness characteristics

© 2016. American Geophysical Union. All Rights Reserved. Few studies have examined the three-dimensional flow structure and bed morphology within elongate loops of large meandering channels. The present study focuses on the spatial patterns of three-dimensional flow structure and bed morphology within two elongate meander loops and examines how differences in outer bank roughness influence near-bank flow characteristics. Three-dimensional velocities were measured during two different events—a near-bankfull flow and an overbank event. Detailed data on channel bathymetry and bed form geometry were obtained during a near-bankfull event. Flow structure within the loops is characterized by strong topographic steering by the point bar, by the development of helical motion associated with flow curvature, and by acceleration of flow where bedrock is exposed along the outer bank. Near-bank velocities during the overbank event are less than those for the near-bankfull flow, highlighting the strong influence of the point bar on redistribution of mass and momentum of the flow at subbankfull stages. Multiple outer bank pools are evident within the elongate meander loop with low outer bank roughness, but are not present in the loop with high outer bank roughness, which may reflect the influence of abundant large woody debris on near-bank velocity characteristics. The positions of pools within both loops can be linked to spatial variations in planform curvature. The findings indicate that flow structure and bed morphology in these large elongate loops is similar to that in small elongate loops, but differs somewhat from flow structure and bed morphology reported for experimental elongate loops

SeDeM Diagram: A New Expert System for the Formulation of Drugs in Solid Form

The SeDeM expert system is a methodology which is applied in preformulation and formulation studies of medicines specifically in solid dosage forms. This system informs on the physical profile of powdered substances (APIs and excipients) used to formulate drugs (Suñé et al, 2005; García et al, 2010; Aguilar et al, 2009). By determining whether powders (API or excipient) are suitable for direct compression, the SeDeM profile will inform about the advantages and gaps of those powdered substance to be used in direct compression, so the system informs on whether the direct compression method is appropriate (e.g.. wet granulation should be applied before compression). The characterization of powdered substances by SeDeM facilitates the identification of the characteristics that require amendment in order to obtain tablets by direct compression. This system thus provides information that will ensure the robust design of the formulation in the final product. This new method is based on the selection and application of several parameters that the formulation must fulfill to ensure a successful tablet elaborated by direct compression..

Fermentative processes for the upcycling of xylose to xylitol by immobilized cells of Pichia fermentans WC1507

Xylitol is a pentose-polyol widely applied in the food and pharmaceutical industry. It can be produced from lignocellulosic biomass, valorizing second-generation feedstocks. Biotechnological production of xylitol requires scalable solutions suitable for industrial scale processes. Immobilized-cells systems offer numerous advantages. Although fungal pellet carriers have gained attention, their application in xylitol production remains unexplored. In this study, the yeast strain P. fermentans WC 1507 was employed for xylitol production. The optimal conditions were observed with free-cell cultures at pH above 3.5, low oxygenation, and medium containing (NH4)(2)SO4 and yeast extract as nitrogen sources (xylitol titer 79.4 g/L, Y-P/S 66.3%, and volumetric productivity 1.3 g/L/h). Yeast cells were immobilized using inactive Aspergillus oryzae pellet mycelial carrier (MC) and alginate beads (AB) and were tested in flasks over three consecutive production runs. Additionally, the effect of a 0.2% w/v alginate layer, coating the outer surface of the carriers (cMC and cAB, respectively), was examined. While Y-P/S values observed with both immobilized and free cells were similar, the immobilized cells exhibited lower final xylitol titer and volumetric productivity, likely due to mass transfer limitations. AB and cAB outperformed MC and cMC. The uncoated AB carriers were tested in a laboratory-scale airlift bioreactor, which demonstrated a progressive increase in xylitol production in a repeated batch process: in the third run, a xylitol titer of 63.0 g/L, Y-P/S of 61.5%, and volumetric productivity of 0.52 g/L/h were achieved. This study confirmed P. fermentans WC 1507 as a promising strain for xylitol production in both free- and entrapped-cells systems. Considering the performance of the wild strain, a metabolic engineering intervention aiming at further improving the efficiency of xylitol production could be justified. MC and AB proved to be viable supports for cell immobilization, but additional process development is necessary to identify the optimal bioreactor configuration and fermentation conditions