302 research outputs found

    Spin symmetry and spin current of helicity eigenstates of the Luttinger Hamiltonian

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    A general spin symmetry argument is proposed for spin currents in semiconductors. In particular, due to the symmetry with respect to spin polarization of the helicity eigenstates of the Luttinger Hamiltonian for a hole-doped semiconductor, the spin polarized flux from a single helicity eigenstate induced by an external electric field, is canceled exactly when all such contributions from eigenstates that are degenerate in energy are summed. Thus, the net spin current predicted by Murakami et al, Science 301, 1348 (2003), cannot be produced by such a Hamiltonian. Possible symmetry breaking mechanisms which may generate a spin current are discussed

    An agent-based hybrid system for microarray data analysis

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    This article reports our experience in agent-based hybrid construction for microarray data analysis. The contributions are twofold: We demonstrate that agent-based approaches are suitable for building hybrid systems in general, and that a genetic ensemble system is appropriate for microarray data analysis in particular. Created using an agent-based framework, this genetic ensemble system for microarray data analysis excels in both sample classification accuracy and gene selection reproducibility.<br /

    The impact of public participation in environmental behavior on haze pollution and public health in China

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    This study extends the STIRPAT model based on Grossman’s health production function and uses Chinese provincial panel data from 2000 to 2017 to examine regional differences in the impacts of public participation in environmental behavior (PPEB), other socioeconomic factors related to haze pollution, and public health level (PHL) in China. We use four econometric techniques and obtain robust results. Overall, results from the system-GMM indicate that an inverted U-shaped relationship, which has not passed its inflection point, exists between PPEB and haze pollution, PPEB and PHL in the different regions, urbanization, and haze pollution except in the eastern region. Both fossil energy consumption and population density promote haze pollution. Income per capita contributes to haze pollution only in the country as a whole and the western region, but improves PHL in the whole of China and the three regions. There is a negative correlation between haze pollution and PHL in each sample. Medical services are substantially conducive to PHL, except in the western region

    A Computational Study of an Implicit Local Discontinuous Galerkin Method for Time-Fractional Diffusion Equations

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    We propose, analyze, and test a fully discrete local discontinuous Galerkin (LDG) finite element method for a time-fractional diffusion equation. The proposed method is based on a finite difference scheme in time and local discontinuous Galerkin methods in space. By choosing the numerical fluxes carefully, we prove that our scheme is unconditionally stable and convergent. Finally, numerical examples are performed to illustrate the effectiveness and the accuracy of the method

    Synthesizing high-frequency rules from different data sources

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    A Schistosoma japonicum chimeric protein with a novel adjuvant induced a polarized Th1 immune response and protection against liver egg burdens

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    <p>Abstract</p> <p>Background</p> <p>Schitosomiasis japonica is still a significant public health problem in China. A protective vaccine for human or animal use represents an important strategy for long-term control of this disease. Due to the complex life cycle of schistosomes, different vaccine design approaches may be necessary, including polyvalent subunit vaccines. In this study, we constructed four chimeric proteins (designated SjGP-1~4) via fusion of Sj26GST and four individual paramyosin fragments. We tested these four proteins as vaccine candidates, and investigated the effect of deviating immune response on protection roles in mice.</p> <p>Methods</p> <p>The immunogencity and protection efficacy of chimeric proteins were evaluated in mice. Next, the chimeric protein SjGP-3 was selected and formulated in various adjuvants, including CFA, ISA 206, IMS 1312 and ISA 70M. The titers of antigen-specific IgG, IgE and IgG subclass were measured. The effect of adjuvant on cytokine production and percentages of CD3<sup>+</sup>CD8<sup>-</sup>IFN-γ<sup>+ </sup>cells and CD3<sup>+</sup>CD8<sup>-</sup>IL-4<sup>+ </sup>cells were analyzed at different time points. Worm burdens and liver egg counts in different adjuvant groups were counted to evaluate the protection efficacy against cercarial challenge.</p> <p>Results</p> <p>Immunization of mice with chimeric proteins provided various levels of protection. Among the four proteins, SjGP-3 induced the highest level of protection, and showed enhanced protective efficacy compared with its individual component Sj26GST. Because of this, SjGP-3 was further formulated in various adjuvants to investigate the effect of adjuvant on immune deviation. The results revealed that SjGP-3 formulated in veterinary adjuvant ISA 70M induced a lasting polarized Th1 immune response, whereas the other adjuvants, including CFA, ISA 206 and IMS 1312, generated a moderate mixed Th1/Th2 response after immunization but all except for IMS 1312 shifted to Th2 response after onset of eggs. More importantly, the SjGP-3/70M formulation induced a significant reduction in liver egg deposition at 47.0–50.3% and the number of liver eggs per female at 34.5–37.2% but less effect on worm burdens at only 17.3–23.1%, whereas no effect of the formulations with other adjuvants on the number of liver eggs per female was observed.</p> <p>Conclusion</p> <p>Construction of polyvalent subunit vaccine was capable to enhance immunogenicity and protection efficacy against schistosomiasis. There was correlation of the polarized Th1 response with reduction of liver egg burdens, supporting the immune deviation strategy for schistosomiasis japonica vaccine development.</p

    Further tests of asset pricing models: Liquidity risk matters

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    The recent asset pricing literature has largely neglected liquidity risk since the price-impact-based factor shows limited pricing ability. Using different liquidity factors, this paper evaluates the liquidity-risk-based models together with the non-liquidity-based ones. With the new testing procedures and the different testing portfolios, we find that the liquidity-augmented capital asset pricing model (LCAPM) performs well. It yields a significant liquidity risk premium robust to all the other models. The success of the LCAPM lies in the fact that the trading-discontinuity-based factor captures the systematic nature of liquidity risk. It shows that liquidity risk is priced highly during the down and turmoil markets, whereas all the other factors examined exhibit insignificant risk prices when market volatility is high. Our evidence indicates that liquidity risk matters and the LCAPM is preferable to use for investment decision making, financial market research and regulation
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