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Progress and prospects of studies on Polymyxa graminis and its transmitted cereal viruses in China

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Progress in Natural Science:Materials International 2005年第6期15卷 481-490页

作者： CHEN Jianping*(Virology and Biotechnology Institute, Zhejiang academy of agricultural sciences, Key Laboratory of Plant Virology, Ministry of Agriculture and Zhejiang Province, Hangzhou 310021, China) Key Laboratory of Plant Virology Virology and Biotechnology Institute Zhejiang Academy of Agricultural Sciences Hangzhou 310021 China

Polymyxa graminis is a eukaryotic obligate biotrophic parasite of plant roots that belongs to a poorly studied discrete taxonomic unit informally called “plasmodiophorids”. P. graminis is nonpathogenic, but has the ability to acquire and transmit nine plant viruses which belong to genera Bymovirus and Furovirus and cause serious diseases in cereal crop species and also result in significant yield reductions in China and elsewhere. Genus Bymovirus contains barley yellow mosaic virus (BaYMV), barley mild mosaic virus (BaMMV), wheat yellow mosaic virus (WYMV), wheat spindle streak mosaic virus (WSSMV), and oat mosaic virus (OMV), and genus Furovirus contains soil-borne wheat mosaic virus (SBWMV), oat golden stripe virus (OGSV), and newly identified Chinese wheat mosaic virus (CWMV) and soil-borne cereal mosaic virus (SBCMV). All these viruses have been sequenced and their worldwide distributions have been studied. The viruses are protected by the environment within P. graminis resting spores that may remain dormant but viable for decades (probably until a suitable host plant is encountered). Spontaneous deletion mutants of SBWMV, OGSV and OMV are detected, and these deletion mutants are not transmissible by the fungus. The persistent, soil-borne nature of these diseases makes the use of virus-resistant crop varieties currently the only practical and environmentally friendly means to control them, and a large number of disease resistant germplasms have been screened.

关键词： Polymyxa graminis cereal viruses genus Bymovirus genus Furovirus.

MODELLING AND NUMERICAL SOLUTIONS OF A GAUGE PERIODIC TIME DEPENDENT GINZBURG-LANDAU MODEL FOR TYPE-Ⅱ SUPERCONDUCTORS

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Journal of Computational Mathematics 1997年第4期15卷 365-384页

作者： Zhi-ming Chen (Institute of Mathematics, Chinese academy of sciences, Beijing, China) 中科院数学所北京

In this paper we seek the solutions of the time dependent Ginzburg-Landau model for type-Ⅱ superconductors such that the associated physical observables are spatially periodic with respect to some lattice whose basic lattice cell is not necessarily rectangular. After appropriately foring the gange, the model can be formulated as a system of nonlinear parabolic partial differential equations with quasi-periodic boundary conditions. We first give some results concerning the existence, uniqueness and regularity of solutions and then we propose a semiimplicit finite element scheme solving the system of nonlinear partial dmerential equations and show the optimal error estimates both in the L2 and energy *** also report on some numerical results at the end of the paper.

关键词： Math QT MODELLING AND NUMERICAL SOLUTIONS OF A GAUGE PERIODIC TIME DEPENDENT GINZBURG-LANDAU MODEL FOR TYPE SUPERCONDUCTORS

A Remark on Using Gravitational Lensing Probability as a Probe of the Central Regions of CDM Halos

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Chinese Journal of Astronomy and Astrophysics 2002年第5期2卷 399-407页

作者： YunLiNational Astronomical Observatories, Chinese academy of sciences, Beijing 100012 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

We calculate the gravitational lensing probabilities by cold dark matter (CDM) halos with different density profiles, and compare them with current observations from the Cosmic Lens All-Sky Survey (CLASS) and the Jodrell-Bank VLA Astrometric Survey (JVAS). We find that the lensing probability is dramatically sensitive to the clumping of the dark matter, or quantitatively, the concentration parameter. We also find that our predicted lensing probabilities in most cases show inconsistency with the observations. It is argued that high lensing probability may not be an effective tool for probing the statistical properties of inner structures of dark matter halos.

关键词： cosmology: dark matter - gravitational lensing - cosmology:theory - galaxies: halos

Genetics and Improvement of Bacterial Blight Resistance of Hybrid Rice in China

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Rice science 2009年第2期16卷 83-92页

作者： ZHANG Qi Institute of Crop sciences Chinese Academy of Agricultural Sciences Beijing 100081 China

Since 1980s, rice breeding for resistance to bacterial blight has been rapidly progressing in China. The gene Xa4 was mainly used in three-line indica hybrid and two-line hybrid rice. The disease has been ＇quiet＇ for 20 years in China, yet in recent years it has gradually emerged and been prevalent in fields planted with newly released rice varieties in the Changjiang River valley. Under the circumstances, scientists inevitably raised several questions： what causes the resurgence and what should we do next？ And/or is resistance breeding still one of the main objectives in rice improvement？ Which approach do we take on resistance breeding so that the resistance will be more durable, and the resistance gene will be used more efficiently？ A combined strategy involving traditional method, molecular marker-assisted selection, and transgenic technology should bring a new era to the bacterial blight resistance hybrid rice breeding program. This review also briefly discusses and deliberates on issues related to the broadening of bacterial blight resistance, and suitable utilization of resistance genes, alternate planting of available resistance genes; and understands the virulent populations of the bacterial pathogen in China even in Asia.

关键词： hybrid rice bacterial blight Xanthomonas oryzae pv. oryzae resistance breeding genetics resistance gene

Differential phosphorylation of p38 induced by apoptotic and anti-apoptotic stimuli in murine hepatocytes

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World Journal of Gastroenterology 2005年第9期11卷 1345-1350页

作者： Li-Xia Guo, Hong Xie, Laboratory of Biotherapy, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological sciences, Chinese academy of sciences Graduate School of the Chinese academy of sciences Laboratory of Biotherapy Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200031 China.

AIM: To investigate the differential phosphorylation and activation of p38 in hepatocytes by pro-apoptotic Transforming Growth Factor-βi (TGF-β1), pro-survival factors Epidermal Growth Factor (EGF) and 12-0- tetradecanoylphorbol-13-acetate (TPA) and the potential mechanisms. METHODS: The phosphorylation and activation of p38 were determined by immunoblotting. Apoptosis was analyzed by morphological staining and observation, FACS analysis of sub-G1 content and DNA fragmentation assay. To quantitatively determine caspase activation, caspase activity assay was performed in vitro. RESULTS: TGF-β1-induced apoptosis was associated with the phosphorylation of p38, and SB202190, a specific inhibitor of p38, which was able to inhibit TGF-β1-induced caspase activation and apoptosis. TPA and EGF also blocked apoptosis induced by TGF-β1. Both of them induced the phosphorylation of p38. The results showed SB202190 had no effect on TGF-β1-induced phosphorylation of p38, but effectively inhibited both EGF and TPA-induced phosphorylation of p38. CONCLUSION: Pro-apoptotic TGF-β1, anti-apoptotic TPA and EGF induce the phosphorylation of p38 through different mechanisms that can be distinguished by SB202190. The data suggest that TPA and EGF-induced p38 phosphorylation is through an autophosphorylation-dependent mechanism. Since p38 phosphorylation induced by TGF-β1 plays an important role in caspase activation and apoptosis, TPA and EGF-induced p38 phosphorylation may not be requisite for their anti-apoptotic function.

关键词： p38 Apoptosis Hepatocytes

THE PRIMAL-DUAL POTENTIAL REDUCTION ALGORITHM FOR POSITIVE SEMI-DEFINITE PROGRAMMING

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Journal of Computational Mathematics 2003年第3期21卷 339-346页

作者： Si-ming Huang(Institute of Policy and Management, academy of Mathematics and System sciences, Chinese academy of sciences, Beijing 100080, China) Institute of Policy and Management Academy of Mathematics and System Sciences Chinese Academy of Sciences 北京 100080

In this paper we introduce a primal-dual potential reduction algorithm for positive semi-definite programming. Using the symetric preserving scalings for both primal and dual interior matrices, we can construct an algorithm which is very similar to the primal-dual potential reduction algorithm of Huang and Kortanek [6] for linear programming. The complexity of the algorithm is either O(nlog(X0 · S0/ε) or O(nlog(X0· S0/ε) depends on the value of ρ in the primal-dual potential function, where X0 and S0 is the initial interior matrices of the positive semi-definite programming.

关键词： Positive semi-definite programming Potential reduction algorithms Complexity.

ON THE ERROR ESTIMATE OF NONCONFORMING FINITE ELEMENT APPROXIMATION TO THE OBSTACLE PROBLEM

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Journal of Computational Mathematics 2003年第4期21卷 481-490页

作者： Lie-heng Wang(LSEC, ICMSEC, academy of Mathematics and System sciences, Chinese academy of sciences,Beijing 100080, China) academy of Mathemutics and System sciences Chinese Academy of Sciences LSEC ICMSECCAS 北京 100080

This paper is devoted to analysis of the nonconforming element approximation to the obstacle problem, and improvement and correction of the results in [11], [12].

关键词： Obstacle problem Nonconforming finite element.

Subspace Search Method for Quadratic Programming With BoxConstraints

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Journal of Computational Mathematics 1999年第3期17卷 307-314页

作者： Zi-luan Wei(ICMSEC, Chinese academy of sciences, Beijing 100080, China) 中科院计算数学与科学工程计算所北京

A subspace search method for solving quadratic programming with box constraints is presented in this paper. The original problem is divided into many independent subproblem at an initial point, and a search direction is obtained by solving each of the subproblem, as well as a new iterative point is determined such that the value of objective function is decreasing. The convergence of the algorithm is proved under certain assumptions, and the numerical results are also given.

关键词： subspace search method quadratic programing matrix splitting

Transcendence of Certain Trigonometric Series

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Acta Mathematica Sinica,English Series 2002年第3期18卷 481-488页

作者： Yao Chen ZHU academy of Mathematics and System sciences. The Chinese academy of sciences, Beijing 100080. P. R. China academy of Mathematics and System sciences The Chinese Academy of Sciences Beijing P. R. China

In this paper the transcendence of values of certain trigonometric series with algebraic coefficients and its derivatives at algebraic points is proved under a general condition dependent only on the coefficients. The... 详细信息

关键词： Transcendence Trigonometric series Linear independence Number field