82 research outputs found

    Emotional intelligence and extra-role behavior: the mediating effect of role stressors and organizational justice in a construction company in China

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    In recent years, with the development of China's foreign infrastructure construction, especially the African countries, as well as the strategy of One Belt And One Road arising, Chinese expatriate as a specific group is becoming bigger. Compared with domestic employees, the work environment of expatriate is quite different. This study is designed to explore whether and how does Chinese expatriate’s emotional intelligence influence their extra-behavior, both organizational citizenship behavior and counterproductive behavior. To test that, 208 Chinese expatriates one construction stated-owned company accepted fulfill the questionnaire and contributed to this study. The results show that emotional intelligence has positive effect on organizational citizenship behavior of Chinese expatriates: Organizational justice, but not role stressor, mediates the relationship between emotional intelligence and organizational citizenship behavior. Emotional intelligence has negative effect on counterproductive behavior of Chinese expatriates. Organizational justice, but not role stressor, can mediate the relationships between emotional intelligence and counterproductive behavior.Nos últimos anos, com o desenvolvimento da construção de infraestruturas no estrangeiro por parte da China, especialmente nos países africanos, bem como a estratégia de One Belt And One Road decorrentes, o número de expatriados chineses está a crescer. Em comparação com os empregados domésticos, o ambiente de trabalho do expatriado é bastante diferente. Este estudo visa explorar se e como a inteligência emocional dos expatriados chineses influencia os seus comportamentos extra-papel: comportamento de cidadania organizacional e comportamento contraproducente. Para testar isso, 208 expatriados chineses numa empresa pública de construção aceitaram participar neste estudo. Os resultados mostram que a inteligência emocional tem um efeito positivo sobre o comportamento de cidadania organizacional dos expatriados chineses. A justiça organizacional, mas não o stress do papel, medeia a relação entre a inteligência emocional e o comportamento de cidadania organizacional. A inteligência emocional tem um efeito negativo sobre o comportamento contraproducente dos expatriados chineses. A justiça organizacional, mas não o stress do papel, medeia a relação entre a inteligência emocional e o comportamento contraproducente. Palavras-chave: inteligência emocional, justiça organizacional, stress de papel, comportamento de cidadania organizacional e comportamento contraproducente

    Multiple hypothesis testing and multiple outlier identification methods

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    Traditional multiple hypothesis testing procedures, such as that of Benjamini and Hochberg, fix an error rate and determine the corresponding rejection region. In 2002 Storey proposed a fixed rejection region procedure and showed numerically that it can gain more power than the fixed error rate procedure of Benjamini and Hochberg while controlling the same false discovery rate (FDR). In this thesis it is proved that when the number of alternatives is small compared to the total number of hypotheses, Storey’s method can be less powerful than that of Benjamini and Hochberg. Moreover, the two procedures are compared by setting them to produce the same FDR. The difference in power between Storey’s procedure and that of Benjamini and Hochberg is near zero when the distance between the null and alternative distributions is large, but Benjamini and Hochberg’s procedure becomes more powerful as the distance decreases. It is shown that modifying the Benjamini and Hochberg procedure to incorporate an estimate of the proportion of true null hypotheses as proposed by Black gives a procedure with superior power. Multiple hypothesis testing can also be applied to regression diagnostics. In this thesis, a Bayesian method is proposed to test multiple hypotheses, of which the i-th null and alternative hypotheses are that the i-th observation is not an outlier versus it is, for i=1,...,m. In the proposed Bayesian model, it is assumed that outliers have a mean shift, where the proportion of outliers and the mean shift respectively follow a Beta prior distribution and a normal prior distribution. It is proved in the thesis that for the proposed model, when there exists more than one outlier, the marginal distributions of the deletion residual of the i-th observation under both null and alternative hypotheses are doubly noncentral t distributions. The “outlyingness” of the i-th observation is measured by the marginal posterior probability that the i-th observation is an outlier given its deletion residual. An importance sampling method is proposed to calculate this probability. This method requires the computation of the density of the doubly noncentral F distribution and this is approximated using Patnaik’s approximation. An algorithm is proposed in this thesis to examine the accuracy of Patnaik’s approximation. The comparison of this algorithm’s output with Patnaik’s approximation shows that the latter can save massive computation time without losing much accuracy. The proposed Bayesian multiple outlier identification procedure is applied to some simulated data sets. Various simulation and prior parameters are used to study the sensitivity of the posteriors to the priors. The area under the ROC curves (AUC) is calculated for each combination of parameters. A factorial design analysis on AUC is carried out by choosing various simulation and prior parameters as factors. The resulting AUC values are high for various selected parameters, indicating that the proposed method can identify the majority of outliers within tolerable errors. The results of the factorial design show that the priors do not have much effect on the marginal posterior probability as long as the sample size is not too small. In this thesis, the proposed Bayesian procedure is also applied to a real data set obtained by Kanduc et al. in 2008. The proteomes of thirty viruses examined by Kanduc et al. are found to share a high number of pentapeptide overlaps to the human proteome. In a linear regression analysis of the level of viral overlaps to the human proteome and the length of viral proteome, it is reported by Kanduc et al. that among the thirty viruses, human T-lymphotropic virus 1, Rubella virus, and hepatitis C virus, present relatively higher levels of overlaps with the human proteome than the predicted level of overlaps. The results obtained using the proposed procedure indicate that the four viruses with extremely large sizes (Human herpesvirus 4, Human herpesvirus 6, Variola virus, and Human herpesvirus 5) are more likely to be the outliers than the three reported viruses. The results with thefour extreme viruses deleted confirm the claim of Kanduc et al

    A comparative study of HPLC-DAD and UPLC-UV methods for simultaneous determination of 11 polyphenols in Moringa oleifera leaves

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    Purpose: To develop, validate and compare two chromatographic methods - high performance liquid chromatography with diode array detector ((HPLC-DAD) and high performance liquid chromatography with ultraviolet detection (UPLC-UV) for the effective analysis of polyphenols in Moringa oleifera leaves.Methods: HPLC-DAD and UPLC-UV methods were applied for the accurate determination of eleven major polyphenols in Moringa oleifera leaves. The chromatographic conditions of the eleven polyphenols was determined on two C18 column by gradient elution with 0.5 % phosphoric acid solution -acetonitrile as the eluate, and at a flow rate of 1.0 and 0.5 mL/min for HPLC-DAD and UPLC-UV methods, respectively. Detector parameter of UPLC-UV was fixed at 203 nm. The assay methods were validated systematically.Results: The instrumental methods (HPLC-DAD and UPLC-UV) had good linearity, precision,repeatability and recovery. For both methods, quantification limits of UPLC-UV (0.057 - 0.363 μg/mL) were lower than those of UPLC-UV (0.094 - 1.532 μg/mL). The UPLC method with a shorter running time and more sensitive detection was applied in comparing to the HPLC method. After optimization and evaluation, the baseline of 11 compounds was separated effectively within 68 and 34 min, respectively.Conclusion: The developed HPLC-DAD and UPLC-UV assays were successfully utilized for thesimultaneous analysis of eleven major polyphenols and can readily be utilized as quality control tools for Moringa oleifera leaves in China, with UPLC-UV method showing better separation, lower organic solvent usage and shorter analytical period

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    A Portfolio-Based Approach to Select Efficient Variable Ordering Heuristics for Constraint Satisfaction Problems

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    Variable ordering heuristics (VOH) play a central role in solving Constraint Satisfaction Problems (CSP). The performance of different VOHs may vary greatly in solving the same CSP instance. In this paper, we propose an approach to select efficient VOHs for solving different CSP instances. The approach contains two phases. The first phase is a probing procedure that runs a simple portfolio strategy containing several different VOHs. The portfolio tries to use each of the candidate VOHs to guide backtracking search to solve the CSP instance within a limited number of failures. If the CSP is not solved by the portfolio, one of the candidates is selected for it by analysing the information attached in the search trees generated by the candidates. The second phase uses the selected VOH to guide backtracking search to solve the CSP. The experiments are run with the MiniZinc benchmark suite and four different VOHs which are considered as the state of the art are involved. The results show that the proposed approach finds the best VOH for more than 67% instances and it solves more instances than all the candidate VOHs and an adaptive VOH based on Multi-Armed Bandit. It could be an effective adaptive search strategy for black-box CSP solvers

    Comprehensive Investigation of Moringa oleifera from Different Regions by Simultaneous Determination of 11 Polyphenols Using UPLC-ESI-MS/MS

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    In this study, we develop and validate a simultaneous quantification of polyphenols method based on an ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) to adequately understand how different habitats influence the quality and profile of Moringa oleifera polyphenol. Furthermore, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to compare and discriminate 25 samples collected from different areas. A significant correlation was found between the polyphenol profile and the collection area. Significant differences in the polyphenol content of Moringa oleifera from different regions indicate that the genetic diversity of Moringa oleifera was relatively rich, possibly due to differences in cultivation conditions, climate, or soil environment resulting in the accumulation of different polyphenols. These observations provide a theoretical basis for subsequent Moringa oleifera germplasm selection and development research. Furthermore, the quantitative analysis methodology used to characterize the polyphenols may be used toward developing quality assessment and future pharmacodynamic investigations of Moringa oleifera
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