210 research outputs found
The resilience of interdependent transportation networks under targeted attack
Modern world builds on the resilience of interdependent infrastructures
characterized as complex networks. Recently, a framework for analysis of
interdependent networks has been developed to explain the mechanism of
resilience in interdependent networks. Here we extend this interdependent
network model by considering flows in the networks and study the system's
resilience under different attack strategies. In our model, nodes may fail due
to either overload or loss of interdependency. Under the interaction between
these two failure mechanisms, it is shown that interdependent scale-free
networks show extreme vulnerability. The resilience of interdependent SF
networks is found in our simulation much smaller than single SF network or
interdependent SF networks without flows.Comment: 5 pages, 4 figure
Cyclohexadione-aniline conjugate inhibits proliferation of melanoma cells via upregulation of Mek 1/2 kinase activity
Purpose: To investigate the antiproliferative effect of cyclohexadione-aniline conjugate (CHAC) on melanoma cells, and the mechanism of action involved.
Methods: Human melanoma cell lines (B16 F1 and A375) were used in this study. The cells were cultured in RPMI 1640 medium supplemented with 10 % fetal bovine serum (FBS) and 1 % penicillin/streptomycin at 37 °C in a humidified atmosphere of 5 % CO2 and 95 % air. After attaining 70 - 80 % confluency, the cells were treated with serum-free medium and graded concentrations of CHAC (10 – 60 μM) for 24 h. Normal cell culture without CHAC served as control group. B16 F1 and A375 cells were used in logarithmic growth phase in this study. Cell viability and apoptosis were assessed using 3-(4, 5-dimethylthiazol-2-yl) 2, 5-diphe¬nyltetrazolium bromide (MTT) and flow cytometric assays, respectively. Western blotting was used to assess the levels of protein expression of X linked inhibitor of apoptosis (XIAP), survivin, p-Erk 1/2, and p-Mek 1/2.
Results: Treatment of B16 F1 and A375 cells with CHAC led to significant and concentrationdependent reductions in their viability (p < 0.05). The proliferation of B16 F1 cells decreased from 93.41 to 32.87 %, while that of A375 cells was reduced from 95.23 to 36.50 %. Treatment of B16 F1 cells with CHAC significantly and concentration-dependently increased the population of cells in G0/G1 phase, and significantly reduced cell proportion in S and G2/M phases (p < 0.05). It also significantly and concentration-dependently promoted apoptosis in B16 F1 cells (p < 0.05). CHAC treatment significantly and concentration-dependently down-regulated the expressions of XIAP and survivin proteins (p < 0.05). Exposure of B16 F1 cells to CHAC significantly and concentration-dependently upregulated the expression of p-Mek 1/2, but down-regulated p-Erk 1/2 protein expression (p < 0.05). Densitometric analysis revealed that the expression of p-Mek 1/2 was increased from 12 to 91 %.
Conclusion: The results of this study indicate that CHAC inhibits the proliferation of melanoma cells via upregulation of Mek 1/2 kinase activity, and therefore may find application in the management of melanoma
Active Globally Explainable Learning for Medical Images via Class Association Embedding and Cyclic Adversarial Generation
Explainability poses a major challenge to artificial intelligence (AI)
techniques. Current studies on explainable AI (XAI) lack the efficiency of
extracting global knowledge about the learning task, thus suffer deficiencies
such as imprecise saliency, context-aware absence and vague meaning. In this
paper, we propose the class association embedding (CAE) approach to address
these issues. We employ an encoder-decoder architecture to embed sample
features and separate them into class-related and individual-related style
vectors simultaneously. Recombining the individual-style code of a given sample
with the class-style code of another leads to a synthetic sample with preserved
individual characters but changed class assignment, following a cyclic
adversarial learning strategy. Class association embedding distills the global
class-related features of all instances into a unified domain with well
separation between classes. The transition rules between different classes can
be then extracted and further employed to individual instances. We then propose
an active XAI framework which manipulates the class-style vector of a certain
sample along guided paths towards the counter-classes, resulting in a series of
counter-example synthetic samples with identical individual characters.
Comparing these counterfactual samples with the original ones provides a
global, intuitive illustration to the nature of the classification tasks. We
adopt the framework on medical image classification tasks, which show that more
precise saliency maps with powerful context-aware representation can be
achieved compared with existing methods. Moreover, the disease pathology can be
directly visualized via traversing the paths in the class-style space
END-TO-END ENCRYPTION AND DECRYPTION WITHIN A HIERARCHICAL SD-WAN WITH AN IPV6 TRANSPORT
Techniques are presented herein that address a singular pain point in a hierarchical software-defined wide area network (SD-WAN) deployment comprising an Internet Protocol (IP) version 6 (IPv6) transport – end-to-end encryption and decryption. Aspects of the presented techniques leverage the IPv6 address schema to support a new concept that may be referred to herein as a micro-Transport Locator (TLOC) or uTLOC. Under the presented techniques, when an Overlay Management Protocol (OMP) virtual private network (VPN) route is published a next hop may be set to the combination of all of the uTLOCs along a path. Within such a context, each router (along the path) may program a customized action (such as, for example, the shifting of a destination, an insertion into a source, etc.) into a routing table for a uTLOC prefix and then forward a packet to a destination edge without the need for decryption and re-encryption operations in an intermediate border router
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