2,580 research outputs found

    Detection of eight different tospovirus species by a monoclonal antibody against the common epitope of NSs protein

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    Rabbit antisera against the nucleocapsid protein (NP) have been commonly used for detection of tospoviruses and classification into serogroups or serotypes. Mouse monoclonal antibodies (MAbs) with high specificity to the NPs have also been widely used to identify tospovirus species. Recently, a serogroup-specific MAb against the NSs protein of Watermelon silver mottle virus (WSMoV) was produced by our laboratory to react with five members of WSMoV serogroup, i.e., WSMoV, Capsicum chlorosis virus (CaCV), Calla lily chlorotic spot virus (CCSV), Peanut bud necrosis virus (PBNV) and Watermelon bud necrosis virus (WBNV). The epitope recognized by the NSs MAb was determined and the comparison with the reported sequences of tospoviral NSs proteins revealed that the epitope is highly conserved at the N-terminal region of NSs proteins among members of WSMoV and Iris yellow spot virus (IYSV) serogroups, and Melon yellow spot virus (MYSV) serotype. When the NSs MAb was further used to react with the crude antigens of MYSV serotype, IYSV and Tomato yellow ring virus (TYRV) of IYSV serogroup, strong serological reactions, both in ELISA and western blotting, were observed. Thus, our results indicated that the NSs MAb is a useful and convenient tool for detection of the eight tospovirus species. It is also suggested that these eight Asian-type tospoviruses, i.e., WSMoV, CaCV, CCSV, PBNV, WBNV, MYSV, IYSV and TYRV, may share a common evolutionary ancesto

    Integral matrices with given row and column sums

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    AbstractLet P = (pij) and Q = (qij) be m × n integral matrices, R and S be integral vectors. Let UPQ(R, S) denote the class of all m × n integral matrices A with row sum vector R and column sum vector S satisfying P ⩽ A ⩽ Q. For a wide variety of classes UPQ(R, S) satisfying our main condition, we obtain two necessary and sufficient conditions for the existence of a matrix in UPQ(R, S). The first characterization unifies the results of Gale-Ryser, Fulkerson, and Anstee. Many other properties of (0, 1)-matrices with prescribed row and column sum vectors generalize to integral classes satisfying the main condition. We also study the decomposibility of integral classes satisfying the main condition. As a consequence of our decomposibility theorem, it follows a theorem of Beineke and Harary on the existence of a strongly connected digraph with given indegree and outdegree sequences. Finally, we introduce the incidence graph for a matrix in an integral class UPQ(R, S) and study the invariance of an element in a matrix in terms of its incidence graph. Analogous to Minty's Lemma for arc colorings of a digraph, we give a very simple labeling algorithm to determine if an element in a matrix is invariant. By observing the relationship between invariant positions of a matrix and the strong connectedness of its incidence graph, we present a very short graph theoretic proof of a theorem of Brualdi and Ross on invariant sets of (0, 1)-matrices. Our proof also implies an analogous theorem for a class of tournament matrices with given row sum vector, as conjectured by the analogy between bipartite tournaments and ordinary tournaments

    The reliability of systems with stair-type consecutive minimal cuts

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    This paper considers the component system with stair-type consecutive minimal cuts. The system consists of n components and the set of minimal cuts can be linearly ordered. The proposed system generalizes the typical consecutive-k-out-of-n: F systems. By using integer linear programming, this paper shows that such a system can be converted into the consecutive-k-out-of-n: F systems with the insertion of artificial "broken-down" components. Then the system reliability can be obtained by the product form of component reliability matrices and the limit behavior of system could be easily analyzed. Additionally, we show that the integer constraints of the linear programming can be relaxed due to the total unimodularity. Thus, a general linear programming can be used to solve the problem. Numerical examples show the simple and effective new approach

    INVESTIGATION OF FOULING PROCESS FOR CONVECTIVE HEAT TRANSFER IN AN ANNULAR DUCT

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    Experimental and theoretical study is summarized of fouling process on heat transfer surface. An automatic monitoring system was set up to determine impact of fouling. Experiments were performed with artificial hard water as a working fluid at different conditions. Some important parameters including water temperature, wall temperature, flow velocity, water hardness and alkalinity were testified to make sure their influences on the fouling process on heat transfer surfaces. The ranges of water temperature, wall temperature, flow velocity and water hardness are between 20~50℃, 50~75℃, 0.5~2.0m/s, 200 ~ 1000mg/L (as CaCO3), respectively. All the experimental data were recorded continuously and the fouling resistances were calculated accordingly. Furthermore, an analysis was conducted to understand mechanism of fouling on heat transfer surface according a new physical model of fouling process. Good agreements can be observed between calculated results and experimental data

    Group polytope faces pursuit for recovery of block-sparse signals

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    This is the accepted version of the article. The final publication is available at link.springer.com. http://www.springerlink.com/content/e0r61416446277w0

    INVESTIGATION OF FOULING PROCESS FOR CONVECTIVE HEAT TRANSFER IN AN ANNULAR DUCT

    Get PDF
    Experimental and theoretical study is summarized of fouling process on heat transfer surface. An automatic monitoring system was set up to determine impact of fouling. Experiments were performed with artificial hard water as a working fluid at different conditions. Some important parameters including water temperature, wall temperature, flow velocity, water hardness and alkalinity were testified to make sure their influences on the fouling process on heat transfer surfaces. The ranges of water temperature, wall temperature, flow velocity and water hardness are between 20~50℃, 50~75℃, 0.5~2.0m/s, 200 ~ 1000mg/L (as CaCO3), respectively. All the experimental data were recorded continuously and the fouling resistances were calculated accordingly. Furthermore, an analysis was conducted to understand mechanism of fouling on heat transfer surface according a new physical model of fouling process. Good agreements can be observed between calculated results and experimental data

    Intergrowth and thermoelectric properties in the Bi-Ca-Co-O system

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    Single crystals of the Bi-Ca-Co-O system have been grown using the flux method with cooling from 900\celsius and 950\celsius, respectively. The single crystals are characterized by transmission electron microscopy and X-ray diffraction. The misfit cobaltite [Ca2_2Bi1.4_{1.4}Co0.6_{0.6}O4_4]RS^{RS}[CoO2_2]1.69_{1.69} single crystals with quadruple (nn=4) rocksalt (RS) layer are achieved with cooling from 900\celsius. Such crystal exhibits room-temperature thermoelectric power (TEP) of 180μ\muV/K, much larger than that in Sr-based misfit cobaltites with quadruple RS layer. However, intergrowth of single crystals of quadruple (nn=4) and triple (nn=3) RS-type layer-based misfit cobaltites is observed with cooling from 950\celsius. Both of TEP and resistivity were obviously enhanced by the intergrowth compared to [Ca2_2Bi1.4_{1.4}Co0.6_{0.6}O4_4]RS^{RS}[CoO2_2]1.69_{1.69} single crystal, while the power factor at room temperature remains unchanged.Comment: 8 pages, 7 figures. To be published in Journal of Crystal Growt

    A Multichannel Spatial Compressed Sensing Approach for Direction of Arrival Estimation

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    The final publication is available at http://link.springer.com/chapter/10.1007%2F978-3-642-15995-4_57ESPRC Leadership Fellowship EP/G007144/1EPSRC Platform Grant EP/045235/1EU FET-Open Project FP7-ICT-225913\"SMALL

    Involvement of lipid rafts in adhesion-induced activation of Met and EGFR

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    <p>Abstract</p> <p>Background</p> <p>Cell adhesion has been shown to induce activation of certain growth factor receptors in a ligand-independent manner. However, the mechanism for such activation remains obscure.</p> <p>Methods</p> <p>Human epidermal carcinoma A431 cells were used as a model to examine the mechanism for adhesion-induced activation of hepatocyte growth factor receptor Met and epidermal growth factor receptor (EGFR). The cells were suspended and replated on culture dishes under various conditions. The phosphorylation of Met at Y1234/1235 and EGFR at Y1173 were used as indicators for their activation. The distribution of the receptors and lipid rafts on the plasma membrane were visualized by confocal fluorescent microscopy and total internal reflection microscopy.</p> <p>Results</p> <p>We demonstrate that Met and EGFR are constitutively activated in A431 cells, which confers proliferative and invasive potentials to the cells. The ligand-independent activation of Met and EGFR in A431 cells relies on cell adhesion to a substratum, but is independent of cell spreading, extracellular matrix proteins, and substratum stiffness. This adhesion-induced activation of Met and EGFR cannot be attributed to Src activation, production of reactive oxygen species, and the integrity of the cytoskeleton. In addition, we demonstrate that Met and EGFR are independently activated upon cell adhesion. However, partial depletion of Met and EGFR prevents their activation upon cell adhesion, suggesting that overexpression of the receptors is a prerequisite for their self-activation upon cell adhesion. Although Met and EGFR are largely distributed in 0.04% Triton-insoluble fractions (<it>i.e</it>. raft fraction), their activated forms are detected mainly in 0.04% Triton-soluble fractions (<it>i.e</it>. non-raft fraction). Upon cell adhesion, lipid rafts are accumulated at the cell surface close to the cell-substratum interface, while Met and EGFR are mostly excluded from the membrane enriched by lipid rafts.</p> <p>Conclusions</p> <p>Our results suggest for the first time that cell adhesion to a substratum may induce a polarized distribution of lipid rafts to the cell-substratum interface, which may allow Met and EGFR to be released from lipid rafts, thus leading to their activation in a ligand-independent manner.</p
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