2,619 research outputs found

    A Comparative Analysis of the Attitudes Toward Women Managers in China, Chile, and the United States

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    Purpose: The purpose of this paper is to determine if stereotypical perceptions of women as managers existed among men and women in three cultural settings: the U.S., China and Chile. Based on the extant literature, hypotheses were developed and tested. Design/Methodology Approach : Participants in our study were students enrolled in degree programs. The data was collected from the U.S., China and Chile. Using the women as mangers scale (WAMS), the study explores attitudinal dimensions. Further, gender and country effects were identified at both multivariate and univariate levels. Findings: The findings show that stereotypical perceptions of women as mangers exist among men and women in three cultural settings (the U.S., China and Chile). For instance, U.S. and Chilean men had more positive perceptions of women as managers than Chinese men. Further, Chinese men and women displayed the lowest perceptions of women as managers. Originality/Value : The results of this study build upon the extant literature and the WAMS scale offer interesting insights for international mangers on perceptions of women as managers in three distinct cultural settings and socioeconomic developments. Implications for research and practice in cross-cultural and international management shed additional light on this important topic

    La actitud del alumnado frente a la escuela

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    Históricamente muchos autores han tratado el tema de la actitud del alumnado frente a la escuela y las motivaciones instrumentales y expresivas de éstos. Estas aportaciones se han desarrollado tanto desde un punto de vista teórico donde encontramos autores como Bernstein (1977), Merton (1938), Fernández Enguita (1988), Subirats y Alegre (2006) o Tarabini (2012); como desde un punto de vista empírico con Alegre y Benito (2012), Barbeta y Termes (2014) o Feito (2003). Siguiendo estas aportaciones, los objetivos de la presente comunicación son: 1.Realizar un breve recorrido por las aportaciones teóricas de diversos autores sobre la actitud del alumnado frente a la escuela y aportar algunas aclaraciones teóricas. 2.En base a esta revisión, se propone una tipología de actitudes frente a la escuela y su contrastación empírica. La comprobación empírica se ha realizado a partir del análisis de los datos de una muestra de 2000 estudiantes que cursaban 4º de ESO en 2013-14 o que habían nacido en el año 1998 y se encontraban en cursos inferiores, matriculados en 27 centros de la ciudad de Barcelona. Estos datos son el resultado de la primera fase de una investigación sobre las trayectorias formativas y laborales de los jóvenes que forma parte de un proyecto internacional de comparación entre ciudades sobre las prácticas educativas, las desigualdades educativas y las trayectorias de los jóvenes después de la escuela obligatoria.The aim of this communication is to explore and analyse students' motivations in compulsory education and examine whether these motivations affect differentially their future expectations. The concrete objectives of this study are twofold: 1.Explore previous empirical and empirical theoretical approaches on students' motivations and attitudes. 2.Propose a typology of attitudes towards the studies and characterize it according to sociodemographic variables and future expectations after compulsory education. The communication will show the results of one part of a larger piece of the International Study of City Youth (ISCY). This is an international longitudinal study of 10th Grade students to find out more about student journeys through school into further study, work and life beyond school. The first student survey was carried out in 27 schools in Barcelona and filled in by 2000 students in their last year of secondary compulsory education (4th ESO) or students born in 1998 (enrolled in lower courses that would correspond)

    Hydrogen peroxide detection with quartz-enhanced photoacoustic spectroscopy using a distributed-feedback quantum cascade laser

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    A quartz-enhanced photoacoustic spectroscopy sensor system was developed for the sensitive detection of hydrogen peroxide (H2O2) using its absorption transitions in the v6 fundamental band at ∼7.73 μm. The recent availability of distributed-feedback quantum cascade lasers provides convenient access to a strong H2O2 absorption line located at 1295.55 cm−1. Sensor calibration was performed by means of a water bubbler that generated titrated average H2O2vapor concentrations. A minimum detection limit of 12 parts per billion (ppb) corresponding to a normalized noise equivalent absorption coefficient of 4.6 × 10−9 cm−1W/Hz1/2 was achieved with an averaging time of 100 s

    Extension of non-minimal derivative coupling theory and Hawking radiation in black-hole spacetime

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    We study the greybody factor and Hawking radiation with a non-minimal derivative coupling between the scalar field and the curvature in the background of the slowly rotating Kerr-Newman black hole. Our results show that both the absorption probability and luminosity of Hawking radiation of the scalar field increase with the coupling. Moreover, we also find that for the weak coupling η<ηc\eta<\eta_c, the absorption probability and luminosity of Hawking radiation decrease when the black hole's Hawking temperature decreases; while for stronger coupling η>ηc\eta>\eta_c, the absorption probability and luminosity of Hawking radiation increase on the contrary when the black hole's Hawking temperature decreases. This feature is similar to the Hawking radiation in a dd-dimensional static spherically-symmetric black hole surrounded by quintessence \cite{chensong}.Comment: 17 pages, 6 figures, 1 table, Title changed, Appendix changed, accepted by JHE

    Effectiveness of a smartphone application for improving healthy lifestyles, a randomized clinical trial (EVIDENT II) : study protocol

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    Background: New technologies could facilitate changes in lifestyle and improve public health. However, no large randomized, controlled studies providing scientific evidence of the benefits of their use have been made. The aims of this study are to develop and validate a smartphone application, and to evaluate the effect of adding this tool to a standardized intervention designed to improve adherence to the Mediterranean diet and to physical activity. An evaluation is also made of the effect of modifying habits upon vascular structure and function, and therefore on arterial aging. Methods/Design: A randomized, double-blind, multicenter, parallel group clinical trial will be carried out. A total of 1215 subjects under 70 years of age from the EVIDENT trial will be included. Counseling common to both groups (control and intervention) will be provided on adaptation to the Mediterranean diet and on physical activity. The intervention group moreover will receive training on the use of a smartphone application designed to promote a healthy diet and increased physical activity, and will use the application for three months. The main study endpoints will be the changes in physical activity, assessed by accelerometer and the 7-day Physical Activity Recall (PAR) interview, and adaptation to the Mediterranean diet, as evaluated by an adherence questionnaire and a food frequency questionnaire (FFQ). Evaluation also will be made of vascular structure and function based on central arterial pressure, the radial augmentation index, pulse velocity, the cardio-ankle vascular index, and carotid intima-media thickness. Discussion: Confirmation that the new technologies are useful for promoting healthier lifestyles and that their effects are beneficial in terms of arterial aging will have important clinical implications, and may contribute to generalize their application in favor of improved population health. Trial registration: Clinical Trials.gov Identifier: NCT0201601

    Fine-Tuning Translation Kinetics Selection as the Driving Force of Codon Usage Bias in the Hepatitis A Virus Capsid

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    Hepatitis A virus (HAV), the prototype of genus Hepatovirus, has several unique biological characteristics that distinguish it from other members of the Picornaviridae family. Among these, the need for an intact eIF4G factor for the initiation of translation results in an inability to shut down host protein synthesis by a mechanism similar to that of other picornaviruses. Consequently, HAV must inefficiently compete for the cellular translational machinery and this may explain its poor growth in cell culture. In this context of virus/cell competition, HAV has strategically adopted a naturally highly deoptimized codon usage with respect to that of its cellular host. With the aim to optimize its codon usage the virus was adapted to propagate in cells with impaired protein synthesis, in order to make tRNA pools more available for the virus. A significant loss of fitness was the immediate response to the adaptation process that was, however, later on recovered and more associated to a re-deoptimization rather than to an optimization of the codon usage specifically in the capsid coding region. These results exclude translation selection and instead suggest fine-tuning translation kinetics selection as the underlying mechanism of the codon usage bias in this specific genome region. Additionally, the results provide clear evidence of the Red Queen dynamics of evolution since the virus has very much evolved to re-adapt its codon usage to the environmental cellular changing conditions in order to recover the original fitness

    On the Potential for Interim Storage in Dense Phase CO2 Pipelines

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    This paper investigates the flexibility that exists within a dense phase carbon dioxide (CO2) pipeline system to accommodate upset conditions in the Carbon Capture and Storage (CCS) network by utilising the pipeline as a storage vessel whilst still maintaining flow into the pipeline. This process is defined in the pipeline industry as “line-packing” and the time available to undertake line-packing is termed the line-packing time. The longer the line-packing time, the more resilient the pipeline system is to flow variations or short term operational issues at the capture or storage site. The aims of the study were; to investigate the impact of typical CO2 pipeline design parameters (diameter, wall thickness and length) as well as CO2 mass flow rate and pipeline inlet and outlet pressure on the available line-packing time and; to derive relationships between the key variables to allow designers to optimise the line-packing time for a pipeline system. The study was undertaken by developing a viable study set of dense phase CO2 pipelines using steady state hydraulic analysis and stress based design principles. The study set was designed to cover the range of design parameters, flow rates and pressures considered to be typical of dense phase pipelines in CCS systems. For each of the pipelines in the study set, the line-packing time was calculated using a transient hydraulic analysis approach. Although by interrogating the results, individual relationships could be identified between key input parameters and the line-packing time, the integration of all of the critical parameters could not be achieved through simple regression analysis techniques. Consequently, using the dataset of pipelines and line-packing times developed, an Artificial Neural Network (ANN) was designed to enable a comprehensive sensitivity analysis of the line-packing time to the input data to be conducted. It is also demonstrated how the ANN can be used as a design tool for the prediction of line-packing time. As would be expected, the line-packing capacity of the pipeline can be increased by increasing the available internal volume of the pipeline, reducing the mass flow rate into the pipeline, increasing the allowable operating stress and managing the inlet pressure and outlet pressures. However, one of the key findings of the work is that, in the dense phase, line-packing times of only up to 8 hours can be achieved for pipeline dimensions typical of those considered for CCS schemes. Consequently it has been confirmed that the pipeline does not represent a long-term storage option for CCS systems. However, if line-packing capability is considered at the design stage then the level of flexibility for the pipeline to act as short-term storage in the network increases. In particular, it is recommended that the effect of increasing the wall thickness on the line-packing time is considered at the design stage to determine the benefits of this option in enabling the pipeline to be used as a short-term storage option in the CCS system and prevent venting of CO2 during short-term outage events at the capture or storage site

    Informe de situación: Actividad gripal en la temporada 2018-19 Evaluación de riesgo hasta semana 03/2019

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    [ES] La epidemia gripal 2018-19 se ha iniciado en España en la semana 01/2019, tres semanas más tarde que en las dos temporadas previas, pero en el rango de las temporadas post-pandémicas previas. La incidencia de gripe se asocia de forma casi exclusiva a la circulación de virus de la gripe tipo A. Aunque la proporción entre subtipos A(H1N1)pdm09 y A(H3N2) es similar, la tendencia de las últimas semanas indica un aumento en la proporción del primero. Los datos de vigilancia en hospitales señalan una distribución similar por tipo/subtipo de virus. Si bien el grupo de mayores de 65 años es el mayoritario (53%), este porcentaje es inferior al que se puede observar en aquellas temporadas en las que predomina A(H3N2) y se parece más a aquellas temporadas en las que predominó A(H1N1)pdm09. Hasta el momento, la epidemia gripal 2018-19 presenta un nivel bajo de transmisibilidad en todos los grupos de edad. El impacto ocasionado en la población española se estima medio, en términos de tasa de hospitalización y bajo en términos de excesos de mortalidad por todas las causas. Ambos indicadores, así como la gravedad clínica de la enfermedad, se seguirán evaluando en las semanas próximas de la epidemia gripal. Las estimaciones preliminares de EV antigripal de esta temporada en Canadá señalan un valor de EV frente a A(H1N1)pdm09 por encima del 70%, en consonancia con datos preliminares de la red Europea I-MOVE. La EV antigripal frente a A(H3N2) es subóptima hasta el momento. Sin embargo, se han estimado valores moderados de EV antigripal frente a todos los virus A en grupos recomendados de vacunación, lo que refuerza la recomendación oficial de vacunación antigripal en estos grupos de riesgo de complicaciones por gripe. En definitiva, las características de la epidemia 2018-19 hasta el momento se mueven en un patrón intermedio entre las temporadas de A(H1N1)pdm09 y las de A(H3N2), de forma que según derive la circulación mayoritaria de uno u otro virus, cabe esperar que predominen unas u otras características. [EN] Influenza activity in Spain started this 2018-19 season in week 01/2019, three weeks later than in the previous two seasons, but in the range of the previous post-pandemic seasons. So far, the influenza season 2018-19 is characterized by the predominant circulation of type A. Although both A(H1N1) pdm09 and A(H3N2) subtypes are co-circulating in similar proportions, the trend of the last weeks indicates an increase in the proportion of the first. Surveillance data in hospitals indicate a similar distribution by type/subtype. Although 53% were adults 65 years of age and older, this percentage is lower than that observed in seasons associated with A(H3N2) predominance, and more similar to those seasons in which A(H1N1)pdm09 predominated. So far, the influenza season 2018-19 has a low level of transmissibility in all age groups. The impact caused in the Spanish population is estimated as “medium”, in terms of hospitalization rates, and “low” in terms of all causes excess mortality. Both indicators, as well as the clinical severity of the disease, will continue to be evaluated in the next few weeks of the flu epidemic. Preliminary estimates of the effectiveness of influenza vaccine this season in Canada indicate good vaccine effectiveness (VE) (above 70%), in line with preliminary data from the European I-MOVE network. The VE against influenza A(H3N2) viruses is suboptimal so far. However, moderate values of VE have been estimated against all A viruses in recommended groups of vaccination, which reinforces the official recommendation of influenza vaccination in these risk groups of complications due to influenza. In short, the characteristics of the influenza season 2018-19 so far move in an intermediate pattern between the A(H1N1)pdm09 seasons and those with A(H3N2) predominance. It is expected that some or other characteristics will prevail depending on the predominance of the circulation of one or the other virus.N

    Galaxy And Mass Assembly (GAMA): mass-size relations of z < 0.1 galaxies subdivided by Sersic index, colour and morphology

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    We use data from the Galaxy And Mass Assembly (GAMA) survey in the redshift range 0.01 < z < 0.1 (8399 galaxies in g to Ks bands) to derive the stellar mass–half-light radius relations for various divisions of ‘early’- and ‘late’-type samples. We find that the choice of division between early and late (i.e. colour, shape, morphology) is not particularly critical; however, the adopted mass limits and sample selections (i.e. the careful rejection of outliers and use of robust fitting methods) are important. In particular, we note that for samples extending to low stellar mass limits (<10 10 M ⊙ ) the Sérsic index bimodality, evident for high-mass systems, becomes less distinct and no-longer acts as a reliable separator of early- and late-type systems. The final set of stellar mass–half-light radius relations are reported for a variety of galaxy population subsets in 10 bands (ugrizZY JHKs) and are intended to provide a comprehensive low-z benchmark for the many ongoing high-z studies. Exploring the variation of the stellar mass–half-light radius relations with wavelength, we confirm earlier findings that galaxies appear more compact at longer wavelengths albeit at a smaller level than previously noted: at 10 10 M ⊙ both spiral systems and ellipticals show a decrease in size of 13 per cent from g to Ks (which is near linear in log wavelength). Finally, we note that the sizes used in this work are derived from 2D Sérsic light profile fitting (using galfit3), i.e. elliptical semimajor half-light radii, improving on earlier low-z benchmarks based on circular apertures

    Galaxy And Mass Assembly (GAMA): mass-size relations of z < 0.1 galaxies subdivided by Sersic index, colour and morphology

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    We use data from the Galaxy And Mass Assembly (GAMA) survey in the redshift range 0.01 < z < 0.1 (8399 galaxies in g to Ks bands) to derive the stellar mass–half-light radius relations for various divisions of ‘early’- and ‘late’-type samples. We find that the choice of division between early and late (i.e. colour, shape, morphology) is not particularly critical; however, the adopted mass limits and sample selections (i.e. the careful rejection of outliers and use of robust fitting methods) are important. In particular, we note that for samples extending to low stellar mass limits (<10 10 M ⊙ ) the Sérsic index bimodality, evident for high-mass systems, becomes less distinct and no-longer acts as a reliable separator of early- and late-type systems. The final set of stellar mass–half-light radius relations are reported for a variety of galaxy population subsets in 10 bands (ugrizZY JHKs) and are intended to provide a comprehensive low-z benchmark for the many ongoing high-z studies. Exploring the variation of the stellar mass–half-light radius relations with wavelength, we confirm earlier findings that galaxies appear more compact at longer wavelengths albeit at a smaller level than previously noted: at 10 10 M ⊙ both spiral systems and ellipticals show a decrease in size of 13 per cent from g to Ks (which is near linear in log wavelength). Finally, we note that the sizes used in this work are derived from 2D Sérsic light profile fitting (using galfit3), i.e. elliptical semimajor half-light radii, improving on earlier low-z benchmarks based on circular apertures
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