In Silico Investigation of Potential Applications of Gamma Carbonic Anhydrases as Catalysts of CO2 Biomineralization Processes: A Visit to the Thermophilic Bacteria Persephonella hydrogeniphila,Persephonella marina,Thermosulfidibacter takaii,and Thermus thermophilus

Carbonic anhydrases (CAs) have been identified as ideal catalysts for CO₂ sequestration. Here, we report the sequence and structural analyses as well as the molecular dynamics (MD) simulations of four γ-CAs from thermophilic bacteria. Three of these, Persephonella marina, Persephonella hydrogeniphila, and Thermosulfidibacter takaii originate from hydrothermal vents and one, Thermus thermophilus HB8, from hot springs. Protein sequences were retrieved and aligned with previously characterized γ-CAs, revealing differences in the catalytic pocket residues. Further analysis of the structures following homology modeling revealed a hydrophobic patch in the catalytic pocket, presumed important for CO₂ binding. Monitoring of proton shuttling residue His69 (P. marina γ-CA numbering) during MD simulations of P. hydrogeniphila and P. marina’s γ-CAs (γ-PhCA and γ-PmCA), showed a different behavior to that observed in the γ-CA of Escherichia coli, which periodically coordinates Zn²⁺. This work also involved the search for hotspot residues that contribute to interface stability. Some of these residues were further identified as key in protein communication via betweenness centrality metric of dynamic residue network analysis. T. takaii’s γ-CA showed marginally lower thermostability compared to the other three γ-CA proteins with an increase in conformations visited at high temperatures being observed. Hydrogen bond analysis revealed important interactions, some unique and others common in all γ-CAs, which contribute to interface formation and thermostability. The seemingly thermostable γ-CA from T. thermophilus strangely showed increased unsynchronized residue motions at 423 K. γ-PhCA and γ-PmCA were, however, preliminarily considered suitable as prospective thermostable CO₂ sequestration agents.     

基于变权物元可拓模型的二次设备状态综合评价

针对二次设备状态评价的特点,提出了基于变权物元可拓的二次设备状态综合评价模型。结合物元可拓理论,确立二次设备的状态信息经典域,建立状态参量物元矩阵。同时,充分考虑权重确定过程的主观性,运用变权理论对各评价指标的权重进行修正,并比较了三种权重确定方法。结果表明,变权法对异常指标具有放大作用,更加符合设备管理要求。最后引入贴近度函数对二次设备的状态进行综合评判。以某220 kV变电站某二次装置为例,评价结果显示设备处于注意状态,偏向异常状态的程度较大,结果基本符合设备实际运行情况,从而验证了该方法的正确性。     

城市广场空间构成要素浅谈

广场作为一种空间原型,其要素有两个,即舞台和观众席。幕布是周围建筑的立面,说明广场不可过大,这样才有一定的封闭性乃至向心性。掌握了广场空间要素,就可将广场整体作为空间原型,并将其应用到建筑设计中。     

Dude,where’s my avacar? A mixed-method examination of communication in the driving context

Drivers who feel social closeness with other drivers tend to drive more safely, according to previous research. Given this, we examine how communication in the driving context influences social closeness, drawing from theories of computer-mediated communication, a context with notable similarities to the road. A survey study found that social closeness with others is associated with greater communication comfort and identity expression through the car, but less treatment of the car as a social entity. An interview study provides context and caveats for these generalizations. Together, these studies present implications for near-future social-mobility services relating to safety on the road.     

道路交通网络中的关键节点识别方法研究

在现实世界中，大量复杂系统都可以通过抽象的节点和连边构成的网络来加以刻画。作为城市交通系统的重要组成部分，道路交通网络是一个典型的复杂系统，与人们的生活密切相关。道路交通网络中的关键节点识别问题是复杂网络领域研究中的一个经典难题。传统的度中心性算法和PageRank算法在复杂网络的关键节点的识别中具有较好的应用，考虑到道路交通网络中关键节点的特殊性和彼此关联性，在度中心性算法的基础上引入贪心算法的思想，提出了一个基于贪心策略的度中心性关键节点识别方法；同时，在PageRank算法的基础上引入贪心算法的思想，提出了一种基于贪心策略的PageRank关键节点识别方法，从而使道路交通网络中关键节点识别的结果更合理，在交通道路维护保养、规划设计，以及犯罪分子潜逃阻断等领域都有重要的应用价值。通过公开数据集与经典的关键节点识别方法做比较，验证了算法的有效性。     

基于FPGA的稀疏网络关键节点计算的硬件加速方法研究

随着互联网、生物医学及社交网络等复杂网络研究的深入,如何寻找其等效图中关键节点越来越重要.中介中心度作为衡量图中节点重要性的主要指标,其单点的计算复杂度高达O(N3),因而成为关键节点计算问题的难点.该文在对传统的中介中心度快速算法进行分析之后,提出了一种适用于硬件设计的改进算法.同时,基于算法中各点独立、以及相邻计算...     

Adaptive synchronization of fractional‐order complex networks via pinning control

Adaptive synchronization of a class of fractional‐order complex networks is investigated in this paper. On the basis of the fractional‐order system stability theory, adaptive synchronization criteria of fractional‐order complex networks with 0 < q < 1 is achieved. Furthermore, pinning control method is then suggested to control the networks, and adaptive strategy is employed to tune the control gains and coupling strength. Because the nodes with high degree may not be the center of the networks, a new attempt to choose the pinned nodes on the basis of the closeness centrality scheme is proposed. Finally, numerical simulations are given to verify the effectiveness of the proposed approach based on the closeness centrality scheme. Copyright © 2012 John Wiley & Sons, Ltd.     

对抗社会网络级联失效的减缓策略研究(英文)

Cascading failures are common phenomena in many of real-world networks,such as power grids,Internet,transportation networks and social networks.It's worth noting that once one or a few users on a social network are unavailable for some reasons,they are more likely to influence a large portion of social network.Therefore,an effective mitigation strategy is very critical for avoiding or reducing the impact of cascading failures.In this paper,we firstly quantify the user loads and construct the processes of cascading dynamics,then elaborate the more reasonable mechanism of sharing the extra user loads with considering the features of social networks,and further propose a novel mitigation strategy on social networks against cascading failures.Based on the realworld social network datasets,we evaluate the effectiveness and efficiency of the novel mitigation strategy.The experimental results show that this mitigation strategy can reduce the impact of cascading failures effectively and maintain the network connectivity better with lower cost.These findings are very useful for rationally advertising and may be helpful for avoiding various disasters of cascading failures on many real-world networks.     

Marital closeness, functional disability, and adjustment in late life.

Socioemotional selectivity theory (SST) posits that emotionally close relationships are increasingly valued as people perceive constraints on time. Based on SST, this study of 1,532 older married persons hypothesized that emotional dimensions of marriage would more strongly predict adjustment at higher levels of functional disability. High levels of marital closeness were negatively associated with depression and anxiety and positively associated with self-esteem. Consistent with predictions derived from SST, marital closeness moderated the negative psychological effects of high levels of functional disability on depression, anxiety, and self-esteem. Results are discussed in the context of SST and traditional stress-buffering models of social support. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

一种改进的EPON网络拓扑结构

首先介绍了EPON的几种现有网络拓扑结构。通过探讨网络的连通性和中心性，研究了EPON网络拓扑结构的可靠性。鉴于原有结构的特点，提出了一种适用于光纤用户接入网的改进的EPON网络拓扑结构。