41 research outputs found

    Route Redundancy-Based Network Topology Measure of Metro Networks

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    The metro system plays a very important role in the urban multimodal transportation system, yet it is susceptible to accidents. A well-designed metro system needs to provide alternative routes to travellers both in the disruptive events and the normal operating conditions for providing rerouting opportunities and balancing crowded lines. This paper provides a new dimension of assessing metro network performance—travellers’ route redundancy (or route diversity), which is defined as the number of behaviourally effective routes between each origin-destination (O-D) pair in the network. The route redundancy of metro network is evaluated by statistical indicators of the distribution of the O-D-level number of effective routes. Compared with the existing connectivity and accessibility measures of topology network performance, route redundancy is also based on the topology network, but it takes the travellers’ route choice into consideration. Specifically, the effective routes between each O-D pair would provide disaggregated information from the travellers’ perspective. Case studies in four metropolises in the world, i.e., Shanghai, Beijing, London, and Tokyo, are conducted to examine the predisaster preparedness of the four metro networks explicitly from the perspective of route redundancy. The results indicate that the London metro network has the best route redundancy performance in terms of the statistical indicators of the distribution of the O-D level number of effective routes. Furthermore, the results of route redundancy are compared with typical measures of topology network performance in terms of measuring connectivity and accessibility of metro networks. Their differences are attributed to the fact that the route redundancy measure considers the travellers’ O-D-level route choice beyond the pure network topology and the shortest path considerations of the existing measures. The route redundancy proposed in this paper could assist in evaluating the predisaster preparedness of current or planning metro networks from O-D level to network level. Document type: Articl

    Extinction in Two-Species Nonlinear Discrete Competitive System

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    We propose a nonlinear discrete system of two species with the effect of toxic substances. By constructing a suitable Lyapunov-type function, we obtain the sufficient conditions which guarantee that one of the components will be driven to extinction while the other will be globally attractive with any positive solution of a discrete equation. Two examples together with their numerical simulations illustrate the feasibility of our main results. The results not only improve but also complement some known results

    Protein Expression of Mesenchymal Stem Cells after Transfection of pcDNA3.1−-hVEGF165 by Ultrasound-Targeted Microbubble Destruction

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    Ultrasound-targeted microbubble destruction (UTMD) has been proposed as a new technique for organ-specific gene transfer and drug delivery. This study was performed to investigate the effect of UTMD on marrow mesenchymal stem cells (MSCs) transfected with pcDNA3.1−-hVEGF165.pcDNA3.1−-hVEGF165 were transfected into the third passage of MSCs, with or without UTMD under different ultrasound conditions. Protein expression was quantified by hVEGF165-ELISA kit after transfection for 24, 48, and 72 hours. UTMD-mediated transfection of MSCs yielded a significant protein expression. UTMD of mechanic index (MI) 0.6 for 90 seconds led to the highest level of protein expression

    The honeysuckle genome provides insight into the molecular mechanism of carotenoid metabolism underlying dynamic flower coloration

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    Lonicera japonica is a wide-spread member of the Caprifoliaceae (honeysuckle) family utilized in traditional medical practices. This twining vine honeysuckle is also a much-sought ornamental, in part due to its dynamic flower coloration, which changes from white to gold during development. The molecular mechanism underlying dynamic flower coloration in L. japonica was elucidated by integrating whole genome sequencing, transcriptomic analysis, and biochemical assays. Here, we report a chromosome-level genome assembly of L. japonica, comprising nine pseudo-chromosomes with a total size of 843.2 Mb. We also provide evidence for a whole genome duplication event in the lineage leading to L. japonica, which occurred after its divergence from Dipsacales and Asterales. Moreover, gene expression analysis not only revealed correlated expression of the relevant biosynthetic genes with carotenoid accumulation, but also suggested a role for carotenoid degradation in L. japonica's dynamic flower coloration. The variation of flower color is consistent with not only the observed carotenoid accumulation pattern, but also with the release of volatile apocarotenoids that presumably serve as pollinator attractants. Beyond novel insights into the evolution and dynamics of flower coloration, the high-quality L. japonica genome sequence also provides a foundation for molecular breeding to improve desired characteristics

    The honeysuckle genome provides insight into the molecular mechanism of carotenoid metabolism underlying dynamic flower coloration

    Get PDF
    Lonicera japonica is a wide-spread member of the Caprifoliaceae (honeysuckle) family utilized in traditional medical practices. This twining vine honeysuckle is also a much-sought ornamental, in part due to its dynamic flower coloration, which changes from white to gold during development. The molecular mechanism underlying dynamic flower coloration in L. japonica was elucidated by integrating whole genome sequencing, transcriptomic analysis, and biochemical assays. Here, we report a chromosome-level genome assembly of L. japonica, comprising nine pseudochromosomes with a total size of 843.2 Mb. We also provide evidence for a whole genome duplication event in the lineage leading to L. japonica, which occurred after its divergence from Dipsacales and Asterales. Moreover, gene expression analysis not only revealed correlated expression of the relevant biosynthetic genes with carotenoid accumulation, but also suggested a role for carotenoid degradation in L. japonica’s dynamic flower coloration. The variation of flower color is consistent with not only the observed carotenoid accumulation pattern, but also with the release of volatile apocarotenoids that presumably serve as pollinator attractants. Beyond novel insights into the evolution and dynamics of flower coloration, the high-quality L. japonica genome sequence also provides a foundation for molecular breeding to improve desired characteristics

    Protein Expression of Mesenchymal Stem Cells after Transfection of pcDNA3.1 − -hVEGF 165 by Ultrasound-Targeted Microbubble Destruction

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    Ultrasound-targeted microbubble destruction (UTMD) has been proposed as a new technique for organ-specific gene transfer and drug delivery. This study was performed to investigate the effect of UTMD on marrow mesenchymal stem cells (MSCs) transfected with pcDNA3.1 − -hVEGF 165 .pcDNA3.1 − -hVEGF 165 were transfected into the third passage of MSCs, with or without UTMD under different ultrasound conditions. Protein expression was quantified by hVEGF 165 -ELISA kit after transfection for 24, 48, and 72 hours. UTMD-mediated transfection of MSCs yielded a significant protein expression. UTMD of mechanic index (MI) 0.6 for 90 seconds led to the highest level of protein expression
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