Beryl: Structural refinement of a sodium-rich natural crystal from Lassur mine (Ariège, France)

The crystal structure rehnement of a blue beryl, abnormally rich in Na, collected in the mine of Lassur (Ariege. France) has been carried out. This Na-beryl is hexagonal, space group P6/mcc with a=9.236(4), c=9.201(5) A; D,i,= ~4.74g cm-' for Z=2. From this refinement the following formula Nao.Be~A1~.~Sis0O.9i ~H. 20w as found. A substitution of Al atom by Fe atom in the octahedral site and an orientational disorder o£ the water molecules in the channels is proposed to explain the crystal stmcture of this beryl

Beryl: Structural refinement of a sodium-rich natural crystal from Lassur mine (Ariège, France)

The crystal structure rehnement of a blue beryl, abnormally rich in Na, collected in the mine of Lassur (Ariege. France) has been carried out. This Na-beryl is hexagonal, space group P6/mcc with a=9.236(4), c=9.201(5) A; D,i,= ~4.74g cm-' for Z=2. From this refinement the following formula Nao.Be~A1~.~Sis0O.9i ~H. 20w as found. A substitution of Al atom by Fe atom in the octahedral site and an orientational disorder o£ the water molecules in the channels is proposed to explain the crystal stmcture of this beryl

Assessing the effect of public subsidies on firm R&D investment: a survey

This survey examines the empirical literature on the relationship between public R&D subsidies and private R&D investment over the past five decades. The survey reveals a considerable heterogeneity of empirical results that cannot be explained fully by methodological issues. We aim to provide further explanations of the possible causes of that heterogeneity. In particular, we emphasise a set of issues that, in our view, are critical to understanding the potential effect of public R&D subsidies on private R&D spending. Special attention is paid to the dynamic aspects and composition of firm R&D, the constraints faced by the firm (such as financial constraints), and the amount and source of public subsidies. None of these issues have been investigated in depth. We formulate a set of research assumptions to guide future empirical research in this field.This study was financially supported by the Spanish Ministry of Science and Innovation (Projects: ECO2012-31358, ECO2012-36775, and ECO2010-21473), Cátedra Iberdrola for Research in Business Management and Organization at Rey Juan Carlos University, and UNIR Research at International University of La RiojaPublicad

Stochastic model to assess bioeconomic impact of PRRS on pig farms in Costa Rica

Despite the economic importance of PRRS and its high prevalence in Costa Rica, there are no studies on the bioeconomic impact of the disease in the country or, even, in Central America. Such studies are essential in finding cost-effective preventive measures tailored for different production circumstances. Therefore, the objective of this study was to evaluate economic and production parameters of a PRRSV-infection for a medium-sized farrow-to-finish pig farm system in Costa Rica with a farm-level stochastic Monte Carlo simulation model. The effect of PRRS was assessed by scenario analysis, in which a baseline PRRS-free situation was compared against three alternative scenarios that assumed low, medium and high PRRS effects. The PRRS effects were based on data from local farms, scientific literature and expert opinion. Sensitivity analyses were performed to assess the impact of key input parameters on output variables. Results show that at the animal level, changes between the baseline and the PRRS-high scenario were estimated as: + 25 d in age to slaughter, - 9.9 pigs to slaughter (per breeding sow/yr), + 6% annual replacement rate, - 255 d in sow productive lifetime, - 6.9 mo in age at culling of sows, and + 24 non- productive days. For a medium size local farm (n = 588 sows), a reduction of 5826 fat pigs to slaughter per farm/yr from baseline compared to PRRS-high scenario was observed. PRRS-induced loss per farm per year was estimated at -US $142,542, US$180,109 and -US $524,719 for PRRS-low, medium and high scenarios, respectively. Revenues/costs ratio changed from 1.12 in the baseline to 0.89 in the PRRS-high scenario. The production cost per kg carcass weight increased from US$2.63 for the baseline to US $3.35 in the PRRS-high scenario. PRRS-induced loss was estimated at US$77.1 per slaughtered pig/yr and US $892 per breeding sow/yr for the PRRS-high scenario. Results from the model indicate that pig farms with medium to high prevalence of PRRS will require optimal market conditions in order to have positive economic outcomes. These results can be helpful in the design of better control strategies for PRRS

Función momento dipolar para moléculas diatómicas

Se formula la aproximación de la función de onda optimizada (AFOO) para la obtención de la función momento dipolar en moléculas diatómicas. El método consiste en la obtención de una función momento dipolar autoconsistente, combinando la información teórica y experimental disponible para los elementos matriz diagonales y no diagonales de la función momento dipolar, mediante el empleo del algoritmo de programación lineal (APL). El método permite determinar, de forma unívoca, los signos adecuados para las amplitudes, y calcular, de forma precisa, cualquier elernento de matriz de la función momento dipolar mediante la optimización de una función lineal, correspondiente a la expresión del elemento de matriz, mediante un esquema de cuadratura numérica. El método se aplica a la molécula de CIH en su estado fundamental X1∑+ y se generan nueve funciones momento dipolar compatibles con la información experimental disponible sobre momentos dipolares en niveles vibracionales individuales

Correlation between Zn vacancies and photoluminescence emission in ZnO films.

Photoluminescence and positron annihilation spectroscopy have been used to characterize and identify vacancy-type defects produced in ZnO films grown on sapphire by metal-organic chemical-vapor deposition. The photoluminescence of the samples in the near band edge region has been studied, paying particular attention to the emission at 370.5 nm (3.346 eV). This emission has been correlated to the concentration of Zn vacancies in the films, which has been determined by positron annihilation [email protected] [email protected]

Cellular and Humoral Mechanisms Involved in the Control of Tuberculosis

Mycobacterium tuberculosis (Mtb) infection is a major international public health problem. One-third of the world's population is thought to have latent tuberculosis, a condition where individuals are infected by the intracellular bacteria without active disease but are at risk for reactivation, if their immune system fails. Here, we discuss the role of nonspecific inflammatory responses mediated by cytokines and chemokines induced by interaction of innate receptors expressed in macrophages and dendritic cells (DCs). We also review current information regarding the importance of several cytokines including IL-17/IL-23 in the development of protective cellular and antibody-mediated protective responses against Mtb and their influence in containment of the infection. Finally, in this paper, emphasis is placed on the mechanisms of failure of Mtb control, including the immune dysregulation induced by the treatment with biological drugs in different autoimmune diseases. Further functional studies, focused on the mechanisms involved in the early host-Mtb interactions and the interplay between host innate and acquired immunity against Mtb, may be helpful to improve the understanding of protective responses in the lung and in the development of novel therapeutic and prophylactic tools in TB

Observaciones preliminares sobrel el impacto de la calificación del riesgo, en el desarrollo económico de un país, caso Colombia

El presente escrito se propone generar condiciones y alternativas sobre la identificación, medición y transferencia de los riesgos financieros y la adaptabilidad de los países según el nivel de desarrollo en el mercado global, tomando come referencia el caso de Colombia, todo con el objetivo de arrojar unas observaciones preliminares sobre el impacto de la medición de las calificadoras internacionales de riesgos, en el desarrollo económico de Colombia, tomando como base el crecimiento del PIB a precios corrientes del periodo 2001 - 2010.Incluye anexos, bibliografí