172 research outputs found
Equity pricing in the mining sector: evidence from NYSE and LSE
The study examines the Capital Asset Pricing Model (CAPM) for the mining sector using weekly stock returns from 27 companies traded on the New York Stock Exchange (NYSE) or on the London Stock Exchange (LSE) for the period of December 2008 to December 2010. The results support the use of the CAPM for the allocation of risk to companies. Most companies involved in precious metals (particularly gold), which have a beta value less than unity (Table 1), have been actuated as shelter values during the financial crisis. Values of R2 do not shown very explanatory power of fitted models (R2 < 70 %). Estimated coefficients beta are not sufficient to determine the expected returns on securities but the results of the tests conducted on sample data for the period analysed do not appear to clearly reject the CAP
Control de calidad de datos diarios en la Península Ibérica
Ponencia presentada en: VI Congreso Internacional de la Asociación Española de Climatología celebrado en Tarragona del 8 al 11 de octubre de 2008.[ES]La calidad de los datos es un requisito necesario en estudios de variabilidad climática,
principalmente cuando se analizan datos de gran resolución espacial y temporal. Para analizar
los extremos climáticos es preciso utilizar datos diarios, pero estas series temporales
evidencian algunos errores debidos a discontinuidades y otros al azar; por ejemplo, que la
precipitación sea menor que cero y que la temperatura máxima sea menor que la mínima para
un día determinado. El procedimiento para corregir estos errores resulta muy complicado y
hemos adoptado los métodos desarrollados en http://cccma.seos.uvic.ca/ETCCDMI
/software.shtml, programados en lenguajes R (RClimDex y RHTest) y Fortran (FClimDex y
FHTest). Mostraremos algunos ejemplos aplicados a datos observados “in situ” y
compararemos la calidad de estos datos frente a la de los datos de reanálisis del NCEP/NCAR.[EN]Data quality has to be considered in studies about climate variability, especially when data
have high spatial and temporal resolutions. The extreme climate research requires daily data
which very often have errors due to discontinuities and other random causes, for example, we
found some negative precipitation values, and maximum temperature lower than minimum.
Therefore, we need to adjust the data to correct these errors. The methods to obtain
homogeneous data are complicated. We have addressed the procedure developed in
http://cccma.seos.uvic.ca/ETCCDMI/software.shtml, that provides software in R (RClimDex
and RHTest) and Fortran (FClimDex and FHTest) languages. In this paper we present some
examples about the adjustment technique applied to observed data “in situ” and we compare
the quality of the observed against the NCEP/NCAR reanalysis data.Este trabajo
ha sido financiado con los proyectos de investigación MEC-CGL2005-06600-CO-01/CLI, de
la Junta de Castilla y León SA039/A05, cofinanciados con fondos europeos y con el proyecto
de ayudas a la investigación “Memoria D. Samuel Solórzano Barruso” de 2008
Presence of Women in Management Bodies of the Professional Associations of the Field of Health in 2015
Fundamentos: La progresiva incorporación de las mujeres en las profesiones sanitarias no se corresponde con su presencia en puestos de responsabilidad. Dado que los colegios profesionales tienen un papel esencial en la representación y regulación profesional, se plantea como objetivo describir la frecuencia de la presencia de las mujeres en las estructuras directivas de los colegios profesionales del ámbito de la salud en España y comprobar el grado de cumplimiento de los criterios de paridad.
Métodos: Se identificó el género de la persona que ocupaba la presidencia, los cargos ejecutivos y la junta directiva visitando las webs del Consejo General de los colegios profesionales de Psicología, Consejo General de Colegios Oficiales de Médicos, Consejo General de Colegios Oficiales de Enfermería de España, Consejo General de Colegios de Fisioterapeutas, Consejo General de Dentistas, Organización Farmacéutica colegial y Consejo
General de Colegios oficiales de Podólogos. Se describió el porcentaje de mujeres de forma global y según profesión y se comparó con las cifras de colegiados y colegiadas según el INE para 2014.
Resultados: De 251 colegios profesionales en julio de 2015, 41 (21,91%) la presidencia estaba ocupada por mujeres. También ocupaban el 34,69% de los puestos ejecutivos y el 42,80% del total de las juntas directivas. Los colegios médicos y de enfermería tenían una mujer en la presidencia en el 11,32% y 43,48% respectivamente. Los de psicología fueron los que presentaron mayor presencia femenina en la presidencia, el 45,83%.
Conclusión: No existe paridad entre hombres y mujeres en el conjunto de los colegios estudiados. La presencia femenina es mayor en colegios de psicología y enfermería y mucho menor en los de odontología, fisioterapia, podología y medicina con el nivel de responsabilidad disminuye la presencia de las mujeres
Production and Characterization of a new Copper(II) Propanoate-Isonicotinamide Adduct obtained via Slow Evaporation and using Supercritical CO2 as an Antisolvent
A new adduct of isonicotinamide (INA) with copper(II) propanoate [Cu(C3)2] was prepared [Cu2(C3)4(INA)4] using two different methods. This type of compound shows high fungicidal activity. Solvent evaporation from ethanol rendered crystals suitable for single-crystal X-ray diffraction. Furthermore, a new semicontinuous method capable of simultaneous crystallization and micronization of the adduct using supercritical CO2, the supercritical antisolvent technique (SAS), was also assessed. Crystals were characterized using powder X-ray diffraction, infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis coupled with mass spectrometry, scanning electron microscopy, and microelemental analysis. In the adduct, two copper(II) ions are coordinated through two bridging and two chelating carboxylates to the propanoate anions forming approximately a plane. Each metal ion is then coordinated with the pyridine nitrogen of two different INA molecules that behave as monodentate ligands. The amide groups of the INA form H-bonds with other amide and carboxylate groups forming a molecular crystal with a three-dimensional H-bond arrangement of the binuclear units. With the SAS technique, crystals 100-fold smaller than those obtained by slow evaporation were obtained, proving SAS as a suitable method for mixed-ligand complexes preparation with reduced particle size and therefore expected bioavailability enhancement
Initial Fitness Recovery of HIV-1 Is Associated with Quasispecies Heterogeneity and Can Occur without Modifications in the Consensus Sequence
BACKGROUND: Fitness recovery of HIV-1 "in vitro" was studied using viral clones that had their fitness decreased as a result of plaque-to-plaque passages. PRINCIPAL FINDINGS: After ten large population passages, the viral populations showed an average increase of fitness, although with wide variations among clones. While 5 clones showed significant fitness increases, 3 clones showed increases that were only marginally significant (p<0.1), and 4 clones did not show any change. Fitness recovery was not accompanied by an increase in p24 production, but was associated with an increase in viral titer. Few mutations (an average of 2 mutations per genome) were detected in the consensus nucleotide sequence of the entire genome in all viral populations. Five of the populations did not fix any mutation, and three of them displayed marginally significant fitness increases, illustrating that fitness recovery can occur without detectable alterations of the consensus genomic sequence. The investigation of other possible viral factors associated with the initial steps of fitness recovery, showed that viral quasispecies heterogeneity increased between the initial clones and the passaged populations. A direct statistical correlation between viral heterogeneity and viral fitness was obtained. CONCLUSIONS: Thus, the initial fitness recovery of debilitated HIV-1 clones was mediated by an increase in quasispecies heterogeneity. This observation, together with the invariance of the consensus sequence despite fitness increases demonstrates the relevance of quasispecies heterogeneity in the evolution of HIV-1 in cell culture
Dietary fatty acid profile: effects on caecal fermentation and performance of young and fattening rabbits
[EN] The present work was performed to study the effect of dietary inclusion of different fatty acid combinations (saturated, n-3 and n-6 polyunsaturated fatty acids; PUFA) on caecal fermentation activity, feed intake, growth rate and feed efficiency of young rabbits around weaning (17 to 44 d) and fattening rabbits (28 to 63 d of age). Five diets were formulated using the same raw materials and including 3% of lard (A diet, rich in saturated fat), sunflower oil (S diet, rich in n-6 PUFA), linseed oil (L diet, rich in n-3 PUFA), sunflower oil and lard at 1:1 rate (SA diet), or linseed oil and lard at 1:1 rate (LA diet). In the first trial, the effect of the 5 diets on rabbit performance was evaluated in a fattening period from 28 to 63 d of age, with 490 rabbits allocated in individual cages; mortality rates were measured with 1670 rabbits (750 allocated in individual cages and 920 in collective cages, 8 rabbits/cage). In the second trial, 120 young rabbits were used from 17 to 44 d of age, weaned at 28 d, allocated in collective cages and randomly fed with A, S or L diets, evaluating performance and gut weight and caecum fermentation activity. The use of animal fat or vegetable oil and the richness in n-3 or n-6 PUFA of vegetable oils had no significant effect on the feed intake (130 g dry matter/d) and growth rate of fattening rabbits (45.5 g/d), but the inclusion of sunflower oil in diet improved feed conversion rate (2.79 for S diet vs. 2.87 for the rest of diets; P<0.01). Mortality rate was lower when vegetable oils were included in diet (34 and 37% for S and L diets respectively vs. 45% for A diet; P<0.05). Feed intake and growth rate increased quickly from 17 to 44 d, but only small occasional differences were recorded in growth rate of young rabbits, in favour of rabbits receiving animal fat from 17 to 21 d (P<0.05) or sunflower oil from 28 to 30 d (P<0.05). Caecal traits of rabbits at 30 and 44 d of age were similar for the different dietary groups, although butyric acid concentration in caecum content at 44 d was the lowest (P<0.05) with L diet.This work was supported by a Ministry of Science and Technology grant (AGL2003-06559-C02-02).Casado, C.; Moya, J.; Pascual, JJ.; Blas Ferrer, E.; Cervera Fras, MC. (2013). Dietary fatty acid profile: effects on caecal fermentation and performance of young and fattening rabbits. World Rabbit Science. 21(4):235-242. https://doi.org/10.4995/wrs.2013.1437SWORD23524221
Uso de plantas comestibles silvestres como ingredientes funcionales en la dieta moderna
Se han evaluado trece especies de plantas silvestres comestibles pertenecientes a
once familias botánicas consumidas en la dieta mediterránea tradicional. Sanguisorba
minor, Quercus ballota y Sedum sediforme mostraron la mayor actividad antioxidante
total hidrofílica (H‐AAT), así como el mayor contenido en fenoles totales. El análisis
sensorial indicó que los frutos de Q. ballota podrían considerarse muy dulces y que las
plantas de Crithmum maritimum y Oxalis pes‐caprae son muy ácidas. Además, los
catadores destacaron el sabor salado de C. maritimum, Mesembryanthemum
nodiflorum y Mesembryanthemum cristalinum, el sabor picante de A. ampeloprasum,
y el aroma de F. vulgare. Nuestros resultados indican que debido a sus propiedades
funcionales y sensoriales, podrían utilizarse como nuevos ingredientes para aumentar
la variedad en la dieta moderna y en la alta cocina creativa
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