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

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]

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

Ordered gan/ingan nanorods arrays grown by molecular beam epitaxy for phosphor-free white light emission

The basics of the self-assembled growth of GaN nanorods on Si(111) are reviewed. Morphology differences and optical properties are compared to those of GaN layers grown directly on Si(111). The effects of the growth temperature on the In incorporation in self-assembled InGaN nanorods grown on Si(111) is described. In addition, the inclusion of InGaN quantum disk structures into selfassembled GaN nanorods show clear confinement effects as a function of the quantum disk thickness. In order to overcome the properties dispersion and the intrinsic inhomogeneous nature of the self-assembled growth, the selective area growth of GaN nanorods on both, c-plane and a-plane GaN on sapphire templates, is addressed, with special emphasis on optical quality and morphology differences. The analysis of the optical emission from a single InGaN quantum disk is shown for both polar and non-polar nanorod orientation

Variants in toll-like receptor 9 gene influence susceptibility to tuberculosis in a Mexican population

Background: The control of Mycobacterium tuberculosis (Mtb) infection begins with the recognition of mycobacterial structural components by toll like receptors (TLRs) and other pattern recognition receptors. Our objective was to determine the influence of TLRs polymorphisms in the susceptibility to develop tuberculosis (TB) in Amerindian individuals from a rural area of Oaxaca, Mexico with high TB incidence. Methods: We carried out a case–control association community based study, genotyping 12 polymorphisms of TLR2, TLR4, TLR6 and TLR9 genes in 90 patients with confirmed pulmonary TB and 90 unrelated exposed but asymptomatic household contacts. Results: We found a significant increase in the frequency of the allele A of the TLR9 gene polymorphism rs352139 (A>G) in the group of TB patients (g.f. = 0.522) when compared with controls (g.f. = 0.383), (Pcorr = 0.01, OR = 1.75). Under the recessive model (A/G + A/A vs G/G) this polymorphism was also significantly associated with TB (Pcorr = 0.01, OR= 2.37). The association of the SNP rs352139 was statistically significant after adjustment by age, gender and comorbidities by regression logistic analysis (Dominant model: p value = 0.016, OR = 2.31; Additive model: p value = 0.023, OR = 1.68). The haplotype GAA of TLR9 SNPs was also associated with TB susceptibility (Pcorr = 0.02). Differences in the genotype or allele frequencies of TLR2, TLR4 and TLR6 polymorphisms between TB patients and healthy contacts were not detected. Conclusions: Our study suggests that the allele A of the intronic polymorphism rs352139 on TLR9 gene might contribute to the risk of developing TB in Mexican Amerindians

Search for dark matter with a 231-day exposure of liquid argon using DEAP-3600 at SNOLAB

DEAP-3600 is a single-phase liquid argon (LAr) direct-detection dark matter experiment, operating 2 km underground at SNOLAB (Sudbury, Canada). The detector consists of 3279 kg of LAr contained in a spherical acrylic vessel. This paper reports on the analysis of a 758  tonne⋅day exposure taken over a period of 231 live-days during the first year of operation. No candidate signal events are observed in the WIMP-search region of interest, which results in the leading limit on the WIMP-nucleon spin-independent cross section on a LAr target of 3.9×10−45  cm2 (1.5×10−44  cm2) for a 100  GeV/c2 (1  TeV/c2) WIMP mass at 90% C.L. In addition to a detailed background model, this analysis demonstrates the best pulse-shape discrimination in LAr at threshold, employs a Bayesian photoelectron-counting technique to improve the energy resolution and discrimination efficiency, and utilizes two position reconstruction algorithms based on the charge and photon detection time distributions observed in each photomultiplier tube

El cuidado de las parteras nahuas prehispánicas de México en las crónicas de fray Bernardino de Sahagún

Introducción: Reconstruir historias contribuye a forjar identidades sólidas. El ejercicio interdisciplinario desde la metodología histórica, permite vincular la disciplina de enfermería con las prácticas tradicionales de la partería del México Antiguo enfocada en la actividad del cuidado de la mujer embarazada. Objetivo: Interpretar el cuidado de las parteras nahuas prehispánicas de México en las crónicas de fray Bernardino de Sahagún. Desarrollo: Se analiza el papel de las parteras nahuas prehispánicas tomando como fuente primaria el facsímil del Códice Florentino o Historia General de las Cosas de Nueva España de fray Bernardino de Sahagún, disponible en la Biblioteca Central de la Universidad Nacional Autónoma de México (UNAM), en conjunto con fuentes secundarias de investigadores especialistas de la cultura náhuatl. Con base en la hermenéutica para la historiografía de la Colonia, la investigación se organiza en dos dimensiones, de lo general a lo particular. Mientras que la primera muestra los aspectos generales, geográficos, la cosmogonía y cosmovisión de la población estudiada; la segunda corresponde a las características sociales, culturales, políticas y fenomenológicas como son símbolos, cualidades, divinidades, además de significaciones en torno a la partera. Conclusiones: El estudio de la historicidad de la partería devela prácticas tradicionales permeadas de la cosmovisión mesoamericana, de las cuales subyace un cuidado multidimensional que ve a la mujer como un reflejo del cosmos, la tierra y el origen de lo sagrado. Asimismo, desde la cosmovisión de la partera se identifica un ejercicio de prácticas tradicionales, de las cuales subyacen premisas clasificadas como supuestos epistemológicos a partir de la acción