Comovimientos entre mercados OCDE y el petróleo: enfoque intensidad condicional en valores extremos

42 p.En esta investigación analizamos el grado de comovimiento que existe en los eventos extremos entre los mercados de valores en las principales potencias de la organización para la cooperación y el desarrollo económico (OCDE) y los mercados del petróleo crudo Brent y West Texas Intermediate (WTI). Para esto se proponen los modelos autorregresivos de intensidad condicional puntos sobre el umbral (ACI-POT), los cuales son capaces de capturar la intensidad de ocurrencia y comovimiento durante períodos dinámicos de crisis, y detectar factores estilizados típicamente presentes en este tipo de series de tiempo. La gran ventaja de esta metodología es que además de considerar la distribución del tamaño de los eventos extremos, utiliza también como fuente de información la distribución temporal de los eventos extremos. Con esto, los modelos ACI-POT son capaces de capturar de mejor forma el comportamiento de los clusters, y por lo tanto, distribuir las violaciones del valor en riesgo (VaR) a través del tiempo. Los resultados muestran una dependencia significativa para la interdependencia negativa de la mayoría de los mercados de la OCDE, destacándose los países de EE.UU, Japón y Francia que presentan alta dependencia al analizar sus pérdidas con los retornos positivos de ambos mercados del petróleo. Mientras que en el análisis de interdependencia positiva no se observa alguna tendencia en el conjunto de países de la OCDE, con excepción de Corea del Sur. Palabras Claves: Teoría de valores extremos, Mercados financieros, Mercados energéticos, Valor en Riesgo, Comovimientos./ABSTRACT: In this research, we analyze the degree of comovement that exists between extreme events across the stock markets of the Organisation for Economic Co-operation and Development (OECD) member nations and the Brent and West Texas Intermediate (WTI) crude oil markets. For this analysis, the autoregressive conditional intensity point over threshold (ACI-POT) models are proposed which are able to dynamically capture the intensity of occurrence and comovement during periods of crisis. These models also capture the stylized factors that are typically present in these time series. The great advantage of this methodology is that, apart from using the size distribution of extreme events, it also uses the occurrence times of extreme events as a source of information. With this information, ACI-POT models are better able to capture the stylized facts of extreme events in financial markets such as clustering behavior and cross-excitement than other models are. The results show a significant, negative interdependence between most OECD markets, especially those of the USA, Japan and France, which display high dependency when parsing losses to positive returns of both oil markets. However, positive interdependence is not observed between any of the OECD countries except for South Korea.Keywords: Extreme Value Theory, Financial Markets, Energy Markets, Value at Risk, Comovements

Magnesium-Nickel alloy for hydrogen storage produced by melt spinning followed by cold rolling

Severe plastic deformation routes (SPD) have been shown to be attractive for short time preparation of magnesium alloys for hydrogen storage, generating refined microstructures and interesting hydrogen storage properties when compared to the same materials processed by high-energy ball milling (HEBM), but with the benefit of higher air resistance. In this study, we present results of a new processing route for Mg alloys for hydrogen storage: rapid solidification followed by cold work. A Mg97Ni3 alloy was processed by melt spinning (MS) and by extensive cold rolling (CR). Submitting Mg97Ni3 ribbons between steel plates to cold rolling has shown to be a viable procedure, producing a thin cold welded foil, with little material waste. The as-processed material presents a high level of [002] fiber texture, a sub microcrystalline grain structure with a high density of defects, and also a fine dispersion of Mg2Ni nanoparticles. This refined microstructure allied to the developed texture resulted in enhanced activation and H-sorption kinetics properties.81381

Biochemical characterization and cytotoxic effect of the skin secretion from the red-spotted Argentina frog Argenteohyla siemersi (Anura: Hylidae)

Background: Argenteohyla siemersi (red-spotted Argentina frog) is a casque-headed tree frog species belonging to the Hylidae family. This species has a complex combination of anti-predator defense mechanisms that include a highly lethal skin secretion. However, biochemical composition and biological effects of this secretion have not yet been studied. Methods: The A. siemersi skin secretion samples were analyzed by mass spectrometry and chromatographic analysis (MALDI-TOF/MS, RP-HPLC and GC-MS). Proteins were also studied by SDS-PAGE. Among the biological activities evaluated, several enzymatic activities (hemolytic, phospholipase A2 , clotting, proteolytic and amidolytic) were assessed. Furthermore, the cytotoxic activity (cytolysis and fluorescence staining) was evaluated on myoblasts of the C2C12 cell line. Results: The MALDI-TOF/MS analysis identified polypeptides and proteins in the aqueous solution of A. siemersi skin secretion. SDS-PAGE revealed the presence of proteins with molecular masses from 15 to 55 kDa. Steroids, but no alkaloids or peptides (less than 5 kDa), were detected using mass spectrometry. Skin secretion revealed the presence of lipids in methanolic extract, as analyzed by CG-MS. This secretion showed hemolytic and phospholipase A2 activities, but was devoid of amidolytic, proteolytic or clotting activities. Moreover, dose-dependent cytotoxicity in cultured C2C12 myoblasts of the skin secretion was demonstrated. Morphological analysis, quantification of lactate dehydrogenase release and fluorescence staining indicated that the cell death triggered by this secretion involved necrosis. Conclusions: Results presented herein evidence the biochemical composition and biological effects of A. siemersi skin secretion and contribute to the knowledge on the defense mechanisms of casque-headed frogs.Fil: Fusco, Luciano Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Cajade, Rodrigo. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Departamento de Biología. Laboratorio de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Piñeiro, Jose Miguel. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Departamento de Biología. Laboratorio de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Torres, Ana M.. Universidad Nacional del Nordeste; ArgentinaFil: da Silva, Igor R. F.. Universidade Estadual de Campinas; BrasilFil: Hyslop, Stephen. Universidade Estadual de Campinas; BrasilFil: Leiva, Laura Cristina Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Pimenta, Daniel C.. Governo do Estado de Sao Paulo. Secretaria da Saude. Instituto Butantan; BrasilFil: Bustillo, Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin

Ultrapassando as barreiras de conversão e tratamento de dados: indicadores de produção científica dos programas de pós-graduação em engenharia de materiais e metalúrgica

The general purpose of this article comprises the elaboration and analysis of indicators based on data of National Graduate Education System (NGES) present on Indicators Notebooks of CAPES. The method used was the exploratory case study and the case unity was the knowledge area Engineering II: subarea Materials Engineering and Metallurgic. It was used bibliometrics as technique of information analysis in a sample of 5364 bibliographic records of scientific papers for the period 2007-2012. As result, bibliometric indicators were elaborated and analyzed on collaboration between PPGs and the evolution of publications. It is concluded that the CAPES's Indicators Notebooks consolidate themselves as a national and public source of information, with an easy access of national scientific production that enables the construction of suitable indicators to the decision making process in order to improve the NGES and the public politics of education, science and technologyO objetivo geral deste estudo compreendeu a elaboração e análise de indicadores baseados em dados do Sistema Nacional de Pós-Graduação (SNPG), disponíveis através dos Cadernos de Indicadores da Capes. O método utilizado foi o estudo de caso e a unidade de análise a área de conhecimento Engenharias II, subárea Engenharia de Materiais e Metalúrgica. Foi empregada a bibliometria como técnica de análise de informação em uma amostra de 5364 registros bibliográficos de artigos científicos referentes ao período de 2007 a 2012. Como resultado, foram elaborados e analisados indicadores bibliométricos sobre a colaboração entre os programas de pós-graduação e a evolução das publicações. Conclui-se que os Cadernos de Indicadores da Capes consolidam-se como uma fonte de informação pública, nacional e disponível a respeito da produção científica nacional, viabilizando a construção de indicadores adequados ao processo de tomada de decisão, visando o aperfeiçoamento do SNPG e das políticas públicas de educação, ciência e tecnologia

Evaluation of the Perkins handheld applanation tonometer in horses and cattle

The objective of this study was to evaluate and validate the accuracy of the Perkins handheld applanation tonometer for measuring intraocular pressure (IOP) in horses and cattle. Both eyes of 10 adult horses and cattle were evaluated in a postmortem study. The eyes from 10 clinically normal adult horses and cattle were also examined after bilateral auriculopalpebral nerve block and topical anesthesia for an in vivo study. IOP was measured postmortem using direct manometry (measured with an aneroid manometer) and tonometry (measured with a Perkins handheld applanation tonometer). The correlation coefficients (r2) for the data from the postmortem manometry and Perkins tonometer study were 0.866 for horses and 0.864 for cattle. In the in vivo study, IOP in horses was 25.1 ± 2.9 mmHg (range 19.0~30.0 mmHg) as measured by manometry and 23.4 ± 3.2 mmHg (range 18.6~28.4 mmHg) according to tonometry. In cattle, IOP was found to be 19.7 ± 1.2 mmHg (range 18.0~22.0 mmHg) by manometry and 18.8 ± 1.7 mmHg (range 15.9~20.8 mmHg) by tonometry. There was a strong correlation between the IOP values obtained by direct ocular manometry and the tonometer in both horses and cattle. Our results demonstrate that the Perkins handheld tonometer could be an additional tool for accurately measuring IOP in equine and bovine eyes

Three Warm Jupiters around Solar-analog Stars Detected with TESS*

We report the discovery and characterization of three giant exoplanets orbiting solar-analog stars, detected by the TESS space mission and confirmed through ground-based photometry and radial velocity measurements taken at La Silla observatory with FEROS. TOI-2373 b is a warm Jupiter orbiting its host star every ∼13.3 days, and is one of the most massive known exoplanet with a precisely determined mass and radius around a star similar to the Sun, with an estimated mass of m _p = ${9.3}_{-0.2}^{+0.2}\,{M}_{\mathrm{jup}}$ and a radius of r _p = ${0.93}_{-0.2}^{+0.2}\,{R}_{\mathrm{jup}}$ . With a mean density of $\rho ={14.4}_{-1.0}^{+0.9}\,{\rm{g}}\,{\mathrm{cm}}^{-3}$ , TOI-2373 b is among the densest planets discovered so far. TOI-2416 b orbits its host star on a moderately eccentric orbit with a period of ∼8.3 days and an eccentricity of e = ${0.32}_{-0.02}^{+0.02}$ . TOI-2416 b is more massive than Jupiter with m _p = ${3.0}_{-0.09}^{+0.10}\,{M}_{\mathrm{jup}}$ , however is significantly smaller with a radius of r _p = ${0.88}_{-0.02}^{+0.02},{R}_{\mathrm{jup}}$ , leading to a high mean density of $\rho ={5.4}_{-0.3}^{+0.3}\,{\rm{g}}\,{\mathrm{cm}}^{-3}$ . TOI-2524 b is a warm Jupiter near the hot Jupiter transition region, orbiting its star every ∼7.2 days on a circular orbit. It is less massive than Jupiter with a mass of m _p = ${0.64}_{-0.04}^{+0.04}\,{M}_{\mathrm{jup}}$ , and is consistent with an inflated radius of r _p = ${1.00}_{-0.03}^{+0.02}\,{R}_{\mathrm{jup}}$ , leading to a low mean density of $\rho ={0.79}_{-0.08}^{+0.08}\,{\rm{g}}\,{\mathrm{cm}}^{-3}$ . The newly discovered exoplanets TOI-2373 b, TOI-2416 b, and TOI-2524 b have estimated equilibrium temperatures of ${860}_{-10}^{+10}$ K, ${1080}_{-10}^{+10}$ K, and ${1100}_{-20}^{+20}$ K, respectively, placing them in the sparsely populated transition zone between hot and warm Jupiters

Enfermedades crónicas

Adherencia al tratamiento farmacológico y relación con el control metabólico en pacientes con DM2Aluminio en pacientes con terapia de reemplazo renal crónico con hemodiálisis en Bogotá, ColombiaAmputación de extremidades inferiores: ¿están aumentando las tasas?Consumo de edulcorantes artificiales en jóvenes universitariosCómo crecen niños normales de 2 años que son sobrepeso a los 7 añosDiagnóstico con enfoque territorial de salud cardiovascular en la Región MetropolitanaEfecto a corto plazo de una intervención con ejercicio físico, en niños con sobrepesoEfectos de la cirugía bariátrica en pacientes con síndrome metabólico e IMC < 35 KG/M2Encuesta mundial de tabaquismo en estudiantes de profesiones de saludEnfermedades crónicas no transmisibles: Consecuencias sociales-sanitarias de comunidades rurales en ChileEpidemiología de las muertes hospitalarias por patologías relacionadas a muerte encefálica, Chile 2003-2007Estado nutricional y conductas alimentarias en adolescentes de 4º medio de la Región de CoquimboEstudio de calidad de vida en una muestra del plan piloto para hepatitis CEvaluación del proceso asistencial y de resultados de salud del GES de diabetes mellitus 2Factores de riesgo cardiovascular en población universitaria de la Facsal, universidad de TarapacáImplicancias psicosociales en la génesis, evolución y tratamiento de pacientes con hipertensión arterial esencialInfarto agudo al miocardio (IAM): Realidad en el Hospital de Puerto Natales, 2009-2010Introducción de nuevas TIC y mejoría de la asistencia a un programa de saludNiños obesos atendidos en el Cesfam de Puerto Natales y su entorno familiarPerfil de la mortalidad por cáncer de cuello uterino en Río de JaneiroPerfil del paciente primo-consultante del Programa de Salud Cardiovascular, Consultorio Cordillera Andina, Los AndesPrevalencia de automedicación en mujeres beneficiarias del Hospital Comunitario de Til-TiPrevalencia de caries en población preescolar y su relación con malnutrición por excesoPrevalencia de retinopatía diabética en comunas dependientes del Servicio de Salud Metropolitano Occidente (SSMOC)Problemas de adherencia farmacológica antihipertensiva en población mapuche: Un estudio cualitativoRol biológico de los antioxidantes innatos en pacientes portadores de VIH/SidaSobrepeso en empleados de un restaurante de una universidad pública del estado de São Paul