1,363 research outputs found

    Preliminary Measurements of Be-10/Be-7 Ratio in Rainwater for Atmospheric Transport Analysis

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    The meteoric cosmogenic beryllium has been used as an essential geophysical tracer in the analysis of atmospheric flows and erosion soils since 1960. The first measurements Be-7 and Be-10 concentrations in rainwater from Mexico, have been carried out by using gamma decay spectroscopy and AMS techniques, respectively for each isotope. With this it was possible to report a preliminar value for the Be-10/Be-7 isotopic ratio in such environmental samples. The present work described preliminary results related to rainwater collected at mountain and metropolitan areas. Results are compared with predictions and previous measurements for both radioisotopes, observing a very sensible behavior particularly for the case of Be-7 activities

    Factors of staff turnover in textile businesses in Colombia

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    The Colombian textile sector, which represents 3% of the gross domestic product, has staff turnover problems. When a worker quits, an immediate replacement is needed in order to not affect productivity. Companies often recruit people without training or even experience. In this paper is analyses job turnover of businesses in the textile sector in Barranquilla (Colombia) through internal, external and contextual factors with their respective indicators. The investigation is quantitative with a correlational scope and a cross-sectional design. The methodology consisted of reliability testing (Cronbach’s alpha and McDonald’s omega) and construct validity (exploratory factor analysis) for the measurement instrument. This was followed by a descriptive analysis, with measures in relation to central tendency and dispersion for each factor indicator, concluding a confirmatory factor analysis with maximum likelihood estimates to observe causality, covariation and incidence relationships. The results established that the relevant indicators are commitment and satisfaction, sickness and company flexibility. The strongest covariance is between internal and contextual factors. Consistent with the theory, it was possible to statistically validate the theoretical model applied and a tool to measure job turnover

    Total and Monomethyl Mercury in Fog Water from the Central California Coast

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    [1] Total mercury (HgT) and monomethyl mercury (MMHg) concentrations in fog collected from 4 locations in and around Monterey Bay, California during June-August of 2011 were 10.7 ± 6.8 and 3.4 ± 3.8 ng L−1respectively. In contrast, mean HgT and MMHg concentrations in rain water from March-June, 2011 were 1.8 ± 0.9 and 0.1 ± 0.04 ng L−1 respectively. Using estimates of fog water deposition from 6 sites in the region using a standard fog water collector (SFC), depositions of HgT and MMHg via fog were found to range from 42–4600 and 14–1500 ng m−2 y−1, which accounted for 7–42% of HgT and 61–99% of MMHg in total atmospheric deposition (fog, rain, and dry deposition), estimated for the coastal area. These initial measurements suggest that fog precipitation may constitute an important but previously overlooked input of MMHg to coastal environments. Preliminary comparisons of these data with associated chemical, meteorological and oceanic data suggest that biotically formed MMHg from coastal upwelling may contribute to the MMHg in fog water

    Estudio Preliminar Sobre La Decoloración Del Residual Líquido De La Producción De Papel Mediante Ozonización

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    Preliminarily, the relationship between Color Reduction (%RC), Total Suspended Solids concentration (SST), and as independent variable, the time of Ozone Oxidation Process, was evaluated with reference values of DQO of the black liquor adjusting its concentration from SST to 300 and 50mg/dm3. A batch reactor of 12,60dm3, an effective height of 3,2dm and an ozone generating device from SEFILTRA company (air flow of 2dm3/min, c(O3) of 9,50mg/dm3 with a O3(g) production 19mg/min) was used. The polynomic correlation was determined from 192 data sets with satisfactory adjustment level (R=0,92; p <0,001). Although, preliminarily, the DQO reduction (%RDQO) was not included in the polynomial relationship, it can be concluded that: a) The %RC and %RDQO is reduced when color and DQO increases from the ozonized sample at same time intervals; this reduction is greater when the SST levels of the ozonized sample increases. b) The %RC and %RDQO decrease when the SST level of the ozonized sample increases. c) Depending on the initial color, of the DQO and of the SST level of the sample, values from 10 to 53 %Rc were obtained after 10 min, and of 66 to 94 %Rc after 60 min

    Levantamiento Detallado de los Suelos de la Granja Experimental del Sena corregimiento de gaira (Santa Marta, Magdalena. Colombia)

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    El trabajo se realizó en la Granja Experimental del Sena, Seccional: Gaira, jurisdicción del municipio de Santa Marta, departamento del Magdalena. Esta se encuentra ubicada astronómicamente entre los 74°-07' y 74° -12' de longitud Oeste y entre los 11°- 11' y 11°- 15' de latitud Norte. La zona recorrida tiene una extensión de 130 Ha. aún cuando sólo se trabajó en 110 Ha. Se encuentra a 4 m.s.n.m y se da en ella una temperatura media anual de 27.3°C y. una precipitación media anual de 557.8 mm. El levantamiento detallado que aquí se presenta, tiene por objeto mostrar en una forma lo más exacta posible, el potencial producido de la zona para una mejor utilización de sus suelos. La principal vía de comunicación que posee, es un carretero que se desprende de la carretera Troncal del Caribe, la cual le permite la comunicación con la ciudad de Santa Marta, capital del departamento del Magdalena, Ciénaga y Barranquilla. También pasa la línea de los ferrocarriles nacionales del Atlántico. La topografía dominante es plana, exceptuando la parte que presenta elevaciones. La principal fuente hidrográfica la constituye el río Gaira que pasa por la parte sur. En general, los suelos de ésta zona son de origen aluvial como se puede comprobar en las calicatas realizadas en la serie Mosquito y en la serie Sena, con drenaje interno y externo de bueno a rápido. Los análisis químicos nos revelaron que éstos suelos son bajos en materia orgánica y fósforo, pero altos en potasio, no presentan problemas con salinidad, pero el calcio y el magnesio son moderadamente altos. La erosión es prácticamente nula. Se puede decir que la población se circunscribe a la explotación mixta del área. (Agricultura y Ganadería). Es necesario aclarar que la granja se encuentra dedicada a impartir en ella, educación a nivel medio y técnico en el campo agropecuario

    Ultracool dwarf benchmarks with \emph{Gaia} primaries

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2017 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.We explore the potential of \emph{Gaia} for the field of benchmark ultracool/brown dwarf companions, and present the results of an initial search for metal-rich/metal-poor systems. A simulated population of resolved ultracool dwarf companions to \emph{Gaia} primary stars is generated and assessed. Of order \sim24,000 companions should be identifiable outside of the Galactic plane (b>10|b| > 10\,deg) with large-scale ground- and space-based surveys including late M, L, T, and Y types. Our simulated companion parameter space covers 0.02M/M0.10.02 \le M/M_{\odot} \le 0.1, 0.1age/Gyr140.1 \le {\rm age/Gyr} \le 14, and 2.5[Fe/H]0.5-2.5 \le {\rm [Fe/H]} \le 0.5, with systems required to have a false alarm probability 0.6\, kau}\,Peer reviewedFinal Accepted Versio

    Factor Structure and Measurement Invariance of the Spanish Burnout Inventory Among Professionals Across 17 Countries and Regions

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    Studies on the prevalence of burnout in professionals in service organizations who work in direct contact with the clients or users of the organization have concluded that burnout is a serious health disorder that has increased due to the COVID-19 pandemic. A significant advantage of the Spanish Burnout Inventory (SBI) over other instruments is that it provides a broader conceptualization of burnout by including feelings of guilt as a dimension of burnout to explain its development. However, the measurement invariance of the SBI across countries has not been investigated. The purpose of this study was to test the measurement invariance of the SBI among professionals across 17 countries and regions in Europe, Latin America, and Asia, and in different languages. All the countries showed a good fit to the four-factor model, except the Indian sample, which was excluded from the measurement invariance study. Using the alignment method, it was possible to verify the scalar measurement invariance of the four SBI factors across 15 countries and one Spanish region (16 samples). The comparison of estimated latent means indicates that France is the country with the lowest scores on the Enthusiasm factor and the highest scores on the negative factors (Exhaustion, Indolence, and Guilt). In contrast, the Andean countries, Colombia, Peru, and Ecuador, show the highest latent means on the Enthusiasm factor and the lowest means on the negative factors. These results support the validity of the SBI in the countries and regions in Europe and Latin America included in this study

    Fecal microbiota composition is related to brown adipose tissue F-18-fluorodeoxyglucose uptake in young adults

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    Objective Human brown adipose tissue (BAT) has gained considerable attention as a potential therapeutic target for obesity and its related cardiometabolic diseases; however, whether the gut microbiota might be an efficient stimulus to activate BAT metabolism remains to be ascertained. We aimed to investigate the association of fecal microbiota composition with BAT volume and activity and mean radiodensity in young adults. Methods 82 young adults (58 women, 21.8 +/- 2.2 years old) participated in this cross-sectional study. DNA was extracted from fecal samples and 16S rRNA sequencing was performed to analyse the fecal microbiota composition. BAT was determined via a static F-18-fluorodeoxyglucose (F-18-FDG) positron emission tomography-computed tomography scan (PET/CT) after a 2 h personalized cooling protocol. F-18-FDG uptake was also quantified in white adipose tissue (WAT) and skeletal muscles. Results The relative abundance of Akkermansia, Lachnospiraceae sp. and Ruminococcus genera was negatively correlated with BAT volume, BAT SUVmean and BAT SUVpeak (all rho = 0.262, P = 0.213, P Conclusion Our results suggest that fecal microbiota composition is involved in the regulation of BAT and glucose uptake by other tissues in young adults. Further studies are needed to confirm these findings.</p
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