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Cascading failure in multimodal transport network may cause huge economic loss and social impact, which has gradually attracted public attention. In view of the coupling effect of nodes in multimodal transport network and the higher complexity of cascading failure process, the concepts of node correlation degree and node cooperation degree are proposed to characterize the characteristics of the network, and a logit model is introduced to calculate the initial load of nodes. In the case of ignoring network interruption, we propose two load redistribution methods: local allocation and global-local allocation. Taking the multimodal transport network in Sichuan–Tibet region of China as an example, the cascading failure effect of multimodal transport network in Sichuan–Tibet region is quantified by sensitivity analysis. The results show that when the load of the multimodal transport network in Sichuan–Tibet region exceeds the maximum capacity but does not exceed 150%∼170% of the network capacity, the network can still operate normally. In addition, the nodes in the multimodal transport network should have 0.3∼0.5 scalable space. In the cascading failure control method, load redistribution based on global-local allocation can minimize the impact of node overload. [ABSTRACT FROM AUTHOR]

The multimodal transport network in the region with complex environment and being easily affected by disturbance factors is used as the research object in our work. The characteristics of the cascading failure of such multimodal transport network were analyzed. From the perspective of network load redistribution, the risk control methods for the cascading failure of the multimodal transport network were investigated. This research aims to solve the problem that traditional load redistribution methods usually ignore the original-destination (OD) constraint and uncertain risks. The conditional value-at-risk (CVaR) was improved based on the Bureau of Public Roads (BPR) road impedance function to quantify the uncertainty of the disturbance factors. A nonlinear programming model was established with the generalized travel time as the objective function. A parallelly-running cellular ant colony algorithm was designed to solve the model. Empirical analysis was conducted on the multimodal transport network in Sichuan-Tibet region of China. The results of the empirical analysis verified the applicability of the proposed load redistribution method to such kind of regions and the effectiveness of the algorithm. This research provides theoretical basis and practical reference for the risk control of the cascading failure of multimodal transport networks in some regions. [ABSTRACT FROM AUTHOR]

Yak yogurt is a type of naturally fermented dairy product prepared by herdsmen in the Qinghai-Tibet Plateau, which is rich in microorganisms. In this study, a strain of Lactobacillus plantarum was isolated and identified from yak yogurt in Hongyuan, Sichuan Province and named Lactobacillus plantarum HFY05 (LP-HFY05). LP-HFY05 was compared with a common commercial strain of Lactobacillus delbrueckii subsp. bulgaricus (LDSB). LP-HFY05 showed better anti-artificial gastric acid and bile salt effects than LDSB in in vitro experiments, indicating its potential as a probiotic. In animal experiments, long-term alcohol gavage induced alcoholic liver injury. LP-HFY05 effectively reduced the liver index of mice with liver injury, downregulated the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, triglyceride, total cholesterol, blood urea nitrogen, nitric oxide, and MDA and upregulated the levels of albumin, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase in the serum of liver-injured mice. LP-HFY05 also reduced the levels of interleukin (IL)-6, IL-12, tumor necrosis factor-alpha, and interferon-gamma in the serum of liver-injured mice. The pathological observations showed that LP-HFY05 reduced the damage to liver cells caused by alcohol. Quantitative polymerase chain reaction and Western blot assays further showed that LP-HFY05 upregulated neuronal nitric oxide synthase, endothelial nitric oxide synthase, manganese-SOD, cuprozinc-SOD, CAT, and inhibitor of κB-α mRNA and protein expression and downregulated the expression of nuclear factor-κB-p65 and inducible nitric oxide synthase in the livers of liver-injured mice. A fecal analysis revealed that LP-HFY05 regulated the microbial content in the intestinal tract of mice with liver injury, increased the content of beneficial bacteria, including Bacteroides, Bifidobacterium, and Lactobacillus and reduced the content of harmful bacteria, including Firmicutes, Actinobacteria, Proteobacteria, and Enterobacteriaceae, thus, regulating intestinal microorganisms to protect against liver injury. The effect of LP-HFY05 on liver-injured mice was better than that of LDSB, and the effect was similar to that of silymarin. LP-HFY05 is a high-quality microbial strain with a liver protective effect on experimental mice with alcoholic liver injury. [ABSTRACT FROM AUTHOR]

The multimodal transport network in the region with complex environment and being easily affected by disturbance factors is used as the research object in our work. The characteristics of the cascading failure of such multimodal transport network were analyzed. From the perspective of network load redistribution, the risk control methods for the cascading failure of the multimodal transport network were investigated. This research aims to solve the problem that traditional load redistribution methods usually ignore the original-destination (OD) constraint and uncertain risks. The conditional value-at-risk (CVaR) was improved based on the Bureau of Public Roads (BPR) road impedance function to quantify the uncertainty of the disturbance factors. A nonlinear programming model was established with the generalized travel time as the objective function. A parallelly-running cellular ant colony algorithm was designed to solve the model. Empirical analysis was conducted on the multimodal transport network in Sichuan-Tibet region of China. The results of the empirical analysis verified the applicability of the proposed load redistribution method to such kind of regions and the effectiveness of the algorithm. This research provides theoretical basis and practical reference for the risk control of the cascading failure of multimodal transport networks in some regions. [ABSTRACT FROM AUTHOR]

Taking multimodal transport network as the research object, a quantitative method of risk propagation based on improved percolation theory is proposed. This paper analyzes the applicability and limitations of the percolation theory for this problem, and improves such four aspects of nodes and edges as the state, the initial load, the percolation probability and the evaluation index of percolation effect, so that they are universal to the risk propagation of the transport network. Taking Sichuan–Tibet​ region as an example for empirical analysis, this paper simulates and analyzes the risk propagation law of the multimodal transport network under different attack types and load preferences. The results show that the risk propagation effect in the multimodal transport network will become stronger with the increase of attack scale and attack intensity, and it will show an exponential growth trend with the increase of attack scale. When other conditions are the same, the order of strength of the three kinds of attack law according to the risk propagation effect is: the intentional attack based on the loads > the random attack > the intentional attack based on the failure probability; the risk propagation effect of the load with preferences is stronger than that without preferences. Therefore, managers can control the risk of multimodal transport network in Sichuan and Tibet from the perspective of controlling attack types and balancing load preference. The research improves the method of risk propagation simulation, makes up for the shortcomings of existing research which neglects the subjectivity of load and the dynamics of risk propagation, and makes it closer to the reality, which is of strong practical value and theoretical significance. • We discusses the limitations of the percolation theory application in the multimodal transport network, and proposes a universal improvement method. • This paper proposes that the subjectivity of load has a certain influence on the risk propagation effect in the network. In order to quantify the subjectivity of load, we use the FMEA, the triangular fuzzy number and the prospect theory to improve the percolation probability, and integrate the subjectivity of load into the redistribution process of load. • This paper proposes the method of combining the static index and the dynamic index to measure the percolation effect, so as to explore the dynamics of risk transmission. • This paper makes an empirical analysis of the multimodal transport network in Sichuan–Tibet region of China, and analyzes the law of risk propagation in the network from such two aspects as the attack type and the load preference, which is of strong practical value. [ABSTRACT FROM AUTHOR]