Resilient Routing Overlay Network Construction with Super-Relay Nodes

( Shengwen Tian ),( Jianxin Liao ),( Tonghong Li ),( Jingyu Wang ),( Guanghai Cui ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.4

Overlay routing has emerged as a promising approach to improve reliability and efficiency of the Internet. The key to overlay routing is the placement and maintenance of the overlay infrastructure, especially, the selection and placement of key relay nodes. Spurred by the observation that a few relay nodes with high betweenness centrality can provide more optimal routes for a large number of node pairs, we propose a resilient routing overlay network construction method by introducing Super-Relay nodes. In detail, we present the K-Minimum Spanning Tree with Super-Relay nodes algorithm (SR-KMST), in which we focus on the selection and connection of Super-Relay nodes to optimize the routing quality in a resilient and scalable manner. For the simultaneous path failures between the default physical path and the overlay backup path, we also address the selection of recovery path. The objective is to select a proper one-hop recovery path with minimum cost in path probing and measurement. Simulations based on a real ISP network and a synthetic Internet topology show that our approach can provide high-quality overlay routing service, while achieving good robustness.

Load-Balanced One-hop Overlay Multipath Routing with Path Diversity

( Jianxin Liao ),( Shengwen Tian ),( Jingyu Wang ),( Tonghong Li ),( Qi Qi ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.2

Overlay routing has emerged as a promising approach to improve reliability and efficiency of the Internet. For one-hop overlay source routing, when a given primary path suffers from the link failure or performance degradation, the source can reroute the traffic to the destination via a strategically placed relay node. However, the over-heavy traffic passing through the same relay node may cause frequent package loss and delay jitter, which can degrade the throughput and utilization of the network. To overcome this problem, we propose a Load-Balanced One-hop Overlay Multipath Routing algorithm (LB-OOMR), in which the traffic is first split at the source edge nodes and then transmitted along multiple one-hop overlay paths. In order to determine an optimal split ratio for the traffic, we formulate the problem as a linear programming (LP) formulation, whose goal is to minimize the worse-case network congestion ratio. Since it is difficult to solve this LP problem in practical time, a heuristic algorithm is introduced to select the relay nodes for constructing the disjoint one-hop overlay paths, which greatly reduces the computational complexity of the LP algorithm. Simulations based on a real ISP network and a synthetic Internet topology show that our proposed algorithm can reduce the network congestion ratio dramatically, and achieve high-quality overlay routing service.

Back-analysis by UDEC of the Failure Process of Wangjiayan Co-seismic Landslide during 2008.5.12 Wenchuan Earthquake.

( Yu Zou ),( Shengwen Qi ),( Songfeng Guo ),( Zhifa Zhan ),( Xiaolin Huang ),( Bowen Zheng ),( Ning Liang ),( Jiaguo Xia ),( Xingxing Li ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Strong earthquakes such as the 2008 Wenchuan earthquake often induced numerous landslides, which resulted in a large number of casualties and property losses. Under a strong earthquake, a rock slope often produced a dynamic progressive failure. Understanding the process of the dynamic progressive failure of the rock slope is of great significance for the prediction and prevention of the co-seismic landslide. Generally, the numerical method is a feasible and economic alternative to solve this problem. However, previous studies presumed the failure surface and area in the numerical model, which cannot reproduce the dynamic progressive failure of the rock slope. In this paper, we applied the Universal Discrete Element method (UDEC) was adopted to quantitatively characterize the dynamic progressive failure process of the Wangjiayan co-seismic landslide triggered by 2008 Wenchan earthquake. Different from previous studies, there exists no presumed failure surface and area was was presumed in the UDEC model. The initiation, coalescence of the local fractures and the formation of the final failure surface were well simulated in a real-time way. Some key factors influencing the dynamic progressive failure of the rock slope were systematically explored. This study provided a new insight to understand the disaster-pregnant mechanism, evolution, and formation of the co-seismic landslide.

The RCAN1.4-calcineurin/NFAT signaling pathway is essential for hypoxic adaption of intervertebral discs

Huang Bao,He Yongqing,Li Shengwen,Wei Xiaoan,Liu Junhui,Shan Zhi,Huang Yue,Chen Jiang,Zhao Fengdong 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

Calcipressin-1, also known as regulator of calcineurin 1 (RCAN1), can specifically bind calcineurin at or near the calcineurin A catalytic domain and downregulate calcineurin activity. However, whether RCAN1 affects the hypoxic intervertebral disc (IVD) phenotype through the calcineurin/NFAT signaling pathway remains unclear. First, we confirmed the characteristics of the degenerative nucleus pulposus (NP) by H&E, safranin O/fast green and Alcian blue staining, and detected increased RCAN1 levels in the degenerative NP by immunohistochemistry. Then, we demonstrated that the protein level of RCAN1.4 was higher than that of RCAN1.1 and progressively elevated from the control group to the Pfirrmann grade V group. In vitro, both hypoxia (1% O2) and overexpression of HIF-1α reduced the protein level of RCAN1.4 in rat NP cells in a dose- and time-dependent manner. We further found that miRNA-124, through a nondegradative pathway (without the proteasome or lysosome), suppressed the expression of RCAN1.4. As expected, calcineurin in NP cells was activated and primarily promoted nuclear translocation of NFATc1 under hypoxia or RCAN1.4 siRNA transfection. Furthermore, SOX9, type II collagen and MMP13 were elevated under hypoxia, RCAN1.4 siRNA transfection or NFATc1 overexpression. Using chromatin immunoprecipitation (ChIP) and a luciferase reporter assay (with mutation), we clarified that NFATc1 increasingly bound the SOX9 promotor region (bp −367~−357). Interaction of HIF-1α and NFATc1 promoted MMP13 transcription. Finally, we found that FK506 reversed hypoxia-induced activation of the calcineurin/NFAT signaling pathway in NP cells and an ex vivo model. Together, these findings show that the RCAN1.4-calcineurin/ NFAT signaling pathway has a vital role in the hypoxic phenotype of NP cells. RCAN1.4 might be a therapeutic target for degenerative disc diseases.

Sulforaphane kills Mycobacterium tuberculosis H37Ra and Mycobacterium smegmatis mc2155 through a reactive oxygen species dependent mechanism

Zhao Yongjie,Shang Shengwen,Song Ya,Li Tianyue,Han Mingliang,Qin Yuexuan,Wei Meili,Xi Jun,Tang Bikui 한국미생물학회 2022 The journal of microbiology Vol.60 No.11

Mycobacterium tuberculosis (M. tuberculosis) is a highly pathogenic intracellular pathogen that causes tuberculosis (TB), the leading cause of mortality from single infections. Redox homeostasis plays a very important role in the resistance of M. tuberculosis to antibiotic damage and various environmental stresses. The antioxidant sulforaphane (SFN) has been reported to exhibit anticancer activity and inhibit the growth of a variety of bacteria and fungi. Nonetheless, it remains unclear whether SFN exhibits anti-mycobacterial activity. Our results showed that the SFN against M. tuberculosis H37Ra exhibited bactericidal activity in a time and dose-dependent manner. The anti-tubercular activity of SFN was significantly correlated with bacterial reactive oxygen species (ROS) levels. In addition, SFN promoted the bactericidal effect of macrophages on intracellular bacteria in a dose-dependent manner, mediated by increasing intracellular mitochondrial ROS levels and decreasing cytoplasmic ROS levels. Taken together, our data revealed the previously unrecognized antimicrobial functions of SFN. Future studies focusing on the mechanism of SFN in macrophages against M. tuberculosis are essential for developing new host-directed therapeutic approaches against TB.