3,822 research outputs found

    Detectability of non-differentiable generalized synchrony

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    Generalized synchronization of chaos is a type of cooperative behavior in directionally-coupled oscillators that is characterized by existence of stable and persistent functional dependence of response trajectories from the chaotic trajectory of driving oscillator. In many practical cases this function is non-differentiable and has a very complex shape. The generalized synchrony in such cases seems to be undetectable, and only the cases, in which a differentiable synchronization function exists, are considered to make sense in practice. We show that this viewpoint is not always correct and the non-differentiable generalized synchrony can be revealed in many practical cases. Conditions for detection of generalized synchrony are derived analytically, and illustrated numerically with a simple example of non-differentiable generalized synchronization.Comment: 8 pages, 8 figures, submitted to PR

    Nurses\u27 Workplace Social Capital and the Influence of Transformational Leadership: A Theoretical Perspective

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    Workplace social capital is the relational network, created by respectful interactions among members of a workforce, can contribute to the formation of a wholesome psychological work environment in an organization. Nurses\u27 workplace social capital is a derivative of the workplace social capital, formed because of the complex interactions among the nursing and between the other healthcare professionals. Transformational leadership is a style of leadership that addresses the emotional wellbeing of its workforce and inspires shared group ethics, norms, and goals. The philosophy of transformational leadership is grounded on the premise of workforce as human beings with specific needs. Transformational leadership has been confirmed as a strong predictor of nurses\u27 workplace social capital. Meanwhile, it is of an academic and/or healthcare industry operational value to scholarly assess and discern the theoretical influence of transformational leadership on nurses\u27 workplace social capital. In this paper, we have attempted to explore the associations between transformational leadership and nurses\u27 workplace social capital from a theoretical perspective. We have discussed the importance of each sub-dimension of transformational leadership (modeling the way, inspiring a shared vision, challenging the process, enabling others to act and encouraging the heart) in building up the social capital relational network. Finally, we have proposed a graphic framework of our analysis to facilitate understanding of the associations between the transformational leadership and nurses\u27 workplace social capital, in formation of a healthy work environment which is the foundation for efficiency and productivity of the workforce

    Uptake and toxicity studies of poly-acrylic acid functionalized silicon nanoparticles in cultured mammalian cells

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    Poly-acrylic acid (PAAc) terminated silicon nanoparticles (SiNPs) have been synthesized and employed as a synchronous fluorescent signal indicator in a series of cultured mammalian cells: HHL5, HepG2 and 3T3-L1. Their biological effects on cell growth and proliferation in both human and mouse cell lines have been studied. There was no evidence of in vitro cytotoxity in the cells exposed to PAAc terminated SiNPS when assessed by cell morphology, cell proliferation and viability, and DNA damage assays. The uptake of the nanocrystals by both HepG2 and 3T3-L1 cells was investigated by confocal microscopy and flow cytometry, which showed a clear time-dependence at higher concentrations. Reconstructed 3-D confocal microscope images exhibited that the PAAc-SiNPs were evenly distributed throughout the cytosol rather than attached to outer membrane. This study provides fundamental evidence for the safe application and further modification of silicon nanoparticles, which could broaden their application as cell markers in living systems and in micelle encapsulated drug delivery systems

    Atomic and molecular interstellar absorption lines toward the high galactic latitude stars HD~141569 and HD~157841 at ultra-high resolution

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    We present ultra-high resolution (0.32 km/s) spectra obtained with the 3.9m Anglo-Australian Telescope (AAT) and Ultra-High-Resolution Facility (UHRF), of interstellar NaI D1, D2, Ca II K, K I and CH absorption toward two high galactic latitude stars HD141569 and HD157841. We have compared our data with 21-cm observations obtained from the Leiden/Dwingeloo HI survey. We derive the velocity structure, column densities of the clouds represented by the various components and identify the clouds with ISM structures seen in the region at other wavelengths. We further derive abundances, linear depletions and H2 fractional abundances for these clouds, wherever possible. Toward HD141569, we detect two components in our UHRF spectra : a weak, broad component at - 15 km/s, seen only in CaII K absorption and another component at 0 km/s, seen in NaI D1, D2, Ca II K, KI and CH absorption. In the case of the HD157841 sightline, a total of 6 components are seen on our UHRF spectra in NaI D1, D2 Ca II K, K I and CH absorption. 2 of these 6 components are seen only in a single species.Comment: 16 pages, Latex, 4 figures, ps files Astrophysical Journal (in press

    Assessing Nurses' Workplace Social Capital : A Study Protocol for Culturally Appropriate Instrument Development

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    Workplace social capital positively influences the quality but reduces the cost of healthcare services. Academic research suffers from limited and inadequate culturally sensitive nurses' workplace social capital instruments. Here we report on the design and protocol of a culturally focused instrument development study in China. The overarching objective of our dual phase study is to develop and validate a questionnaire measuring nurses' workplace social capital tailored toward Chinese cultural values and norms. In the first phase of INSTRUMENT DEVELOPMENT, the qualitative phase, we will conduct interviews with purposefully sampled nurses from five geographically diverse regions capturing 16 provinces in China to formulate the initial version of the Nurses' Workplace Social Capital Questionnaire (NWSCQ). Data collection will be stopped at the saturation point and content analysis will be performed for interview data in parallel. The initial version of the NWSCQ will be evaluated and confirmed by two-rounds of expert consultation (target N = 20) and pre-tested among 70 nurses. During the second phase of INSTRUMENT VALIDATION or the quantitative phase, we will validate the psychometric properties of the NWSCQ. The validity and reliability of the questionnaire will be examined and validated through three cross-sectional surveys among nurses (target N = 1154) randomly selected from 12 tertiary hospitals. We have reported our study protocol with the intention of sharing our experience with researchers in other countries who are striving to advance the phenomenon of culturally sensitive and social normatively appropriate nurses' workplace social capital. Findings from our study should advance the development of culturally appropriate and valid instrument of nurses' workplace social capital, another important step toward recognition and incorporation of cultural diversity in the daily operation of healthcare industry.Peer reviewe

    A Symmetry-induced Model of Elliptical Galaxy Patterns

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    S\'ersic (1968) generalized the de Vaucouleurs law which follows the projected (observed) one dimensional radial profile of elliptical galaxies closely and Dehnen (1993) proposed an analytical formula of the 3-dimensional light distributions whose projected line profile resembles the de Vaucouleurs law. This paper is involved to recover the Dehnen model and generalize the model to account for galaxy elliptical shapes by means of curvilinear coordinate systems and employing a symmetry principle. The symmetry principle maps an orthogonal coordinate system to a light distribution pattern. The coordinate system for elliptical galaxy patterns turns out to be the one which is formed by the complex-plane reciprocal transformation Z=1/WZ=1/W. The resulting spatial (3-dimensional) light distribution is spherically symmetric and has infinite gradient at its centre, which is called spherical-nucleus solution and is used to model galaxy central area. We can make changes of the coordinate system by cutting out some column areas of its definition domain, the areas containing the galaxy centre. The resulting spatial (3-dimensional) light distributions are axisymmetric or triaxial and have zero gradient at the centre, which are called elliptical-shape solutions and are used to model global elliptical patterns. The two types of logarithmic light distributions are added together to model full elliptical galaxy patterns. The model is a generalization of the Dehnen model. One of the elliptical-shape solutions permits realistic numerical calculation and is fitted to all R-band elliptical images from the Frei {\it et al.}(1996)'s galaxy sample. The fitting is satisfactory. This suggests that elliptical galaxy patterns can be represented in terms of a few basic parameters.Comment: 20 pages, 7 figure

    Preferential regulation of stably expressed genes in the human genome suggests a widespread expression buffering role of microRNAs

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    In this study, we comprehensively explored the stably expressed genes (SE genes) and fluctuant genes (FL genes) in the human genome by a meta-analysis of large scale microarray data. We found that these genes have distinct function distributions. miRNA targets are shown to be significantly enriched in SE genes by using propensity analysis of miRNA regulation, supporting the hypothesis that miRNAs can buffer whole genome expression fluctuation. The expression-buffering effect of miRNA is independent of the target site number within the 3'-untranslated region. In addition, we found that gene expression fluctuation is positively correlated with the number of transcription factor binding sites in the promoter region, which suggests that coordination between transcription factors and miRNAs leads to balanced responses to external perturbations

    Graph Zeta Function and Gauge Theories

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    Along the recently trodden path of studying certain number theoretic properties of gauge theories, especially supersymmetric theories whose vacuum manifolds are non-trivial, we investigate Ihara's Graph Zeta Function for large classes of quiver theories and periodic tilings by bi-partite graphs. In particular, we examine issues such as the spectra of the adjacency and whether the gauge theory satisfies the strong and weak versions of the graph theoretical analogue of the Riemann Hypothesis.Comment: 35 pages, 7 Figure

    Potential of Visible and Near Infrared Spectroscopy and Pattern Recognition for Rapid Quantification of Notoginseng Powder with Adulterants

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    Notoginseng is a classical traditional Chinese medical herb, which is of high economic and medical value. Notoginseng powder (NP) could be easily adulterated with Sophora flavescens powder (SFP) or corn flour (CF), because of their similar tastes and appearances and much lower cost for these adulterants. The objective of this study is to quantify the NP content in adulterated NP by using a rapid and non-destructive visible and near infrared (Vis-NIR) spectroscopy method. Three wavelength ranges of visible spectra, short-wave near infrared spectra (SNIR) and long-wave near infrared spectra (LNIR) were separately used to establish the model based on two calibration methods of partial least square regression (PLSR) and least-squares support vector machines (LS-SVM), respectively. Competitive adaptive reweighted sampling (CARS) was conducted to identify the most important wavelengths/variables that had the greatest influence on the adulterant quantification throughout the whole wavelength range. The CARS-PLSR models based on LNIR were determined as the best models for the quantification of NP adulterated with SFP, CF, and their mixtures, in which the rP values were 0.940, 0.939, and 0.867 for the three models respectively. The research demonstrated the potential of the Vis-NIR spectroscopy technique for the rapid and non-destructive quantification of NP containing adulterants
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