Pub/Sub系统中基于免疫的新型路由算法

为减少Pub/Sub系统中因遍历节点而产生的广播负载,在无标度网络的Pub/Sub系统遍历路由的基础上,提出了基于免疫思想的新型路由算法。第一阶段,通过设置阈值δ,选择初始免疫节点;第二阶段,通过投票机制进一步甄选核心代理节点和免疫节点。仿真实验表明所提出的方法与Pub/Sub系统中传统的Gossip算法及洪泛算法相比较,能够限制消息在确定的范围内传播并且降低消息遍历的时间和广播开销的负载。基于免疫的新型路由算法可加快消息的传播速度、降低网络开销。     

基于K-shell分解与邻居节点度去噪的链路预测方法

链路预测是研究复杂网络结构和演化机制的重要工具,提高链路预测的精度具有重要价值。针对传统的基于网络拓扑结构相似性算法预测精度偏低的问题,从网络优化去噪的角度进行分析,提出了一种基于K-shell分解与邻居节点度（KSDNN）去噪的链路预测方法。该方法首先从全局的角度通过K-shell分解对复杂网络中所有节点进行重要性排序,然后从局部的角度结合节点邻居节点的度对节点重要性进行综合评判,最后对网络数据进行优化后进行链路预测。通过在四个不同的真实网络进行验证,实验结果表明,所提方法预测精度优于K-shell去噪的方法,且相较于传统算法预测精度平均提升了2%左右。     

Stability analysis and H∞ control for hybrid complex dynamical networks with coupling delays

This paper formulates and studies a model of complex dynamical networks with switching topology and coupling delays. Based on the hybrid control and Lyapunov function, the stability and robust H_∞ control of such networks with impulsive and switching effects, which have not been studied before, are addressed with some criteria derived. Examples are given to illustrate the effectiveness of the theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.     

改进的Beamlet与Canny相结合提取复杂图像线特征

传统Beamlet无结构算法在提取图像线特征时不仅存在重叠模糊的缺陷,而且在提取复杂图像线特征时不能有效地检测出目标信息,细节特征更是难以刻画。针对这些问题,提出将改进的Beamlet无结构算法与Canny算子相结合的方法提取复杂图像的线特征。首先,对图像进行Beamlet变换,通过改进Beamlet无结构算法,采用新的能量统计和制定新的划线规则,以保证每个二进方块最多有一条最优基;然后,对图像用Canny算子检测边缘,通过选取较大的Sigma,只检测明显的大边缘;最后,两者结合得到图像的线特征。从检测的线特征的线型连接程度等方面对该算法的性能进行了评价,并与现有的方法进行了比较,实验结果表明,该方法克服了两种方法单独提取线特征时存在的断裂、重叠、模糊和虚假边缘的缺点,有效地提高了复杂图像线特征提取的准确性和连续性。     

工业设计决策网络构建及其动态演化仿真

针对工业设计过程多阶段方案决策的意见演化问题,融合复杂网络理论建立工业设计决策网络模型,通过意见动力学进行决策意见动态演化仿真.基于图论建立设计决策有权无向网络,以网络效率变化确定决策者权重,借助意见距离识别设计决策网络节点信任集合,利用加权平均意见驱动设计决策网络更新与演化. 提出工业设计决策网络的演化仿真流程,结合产品设计方案决策数据进行动态仿真分析,结果表明：信任阈值决定设计决策网络拓扑构成,随着网络演化的进行,决策个体间意见差异逐步缩小并最终达成共识;设计决策网络分析能够析出噪声节点及其意见变化,在实际产品设计决策中应重点关注;意见演化能够辅助确定工业设计方案决策轮次,明确方案在各指标上的表现并识别设计改进方向;仿真分析有助于发现设计决策中的关键因素和意见演化规律.     

Effect of sulfate on Cu(Ⅱ) sorption to polymer-supported nano-hydrated ferric oxides: Experimental and modeling studies

Incorporating of hydrous ferric oxide(HFO) inside porous supports with large sizes has become an effective way to decontaminate the water from heavy metals. Ubiquitous anions like sulfate are usually present in high concentrations in water, and might greatly affect adsorption behavior of hybrid HFO. Here, a polymer-based HFO-CPS was fabricated by encapsulating nano-HFO inside a chloromethylated polystyrene polymer(CPS) and the reactivity of HFO-CPS with Cu(Ⅱ) was evaluated in the presence of sulfate ions.Surface complexation theory was firstly employed to describe the effect of sulfate on Cu(Ⅱ) adsorption edges of hybrid HFO-CPS, where constant capacitance model(CCM) was adopted. The available weak adsorption site Fe_((2))OH of hybrid HFO-CPS was found to decrease from 20% Fe to 5% Fe, which might be caused by the pore plugging effect after HFO encapsulation. With the assumption that a ternary complex was formed, the effect of sulfate on Cu(Ⅱ) adsorption by HFO-CPS were successfully described by CCM using the optimized Fe_((2))OH site under different sulfate concentrations(1 or 10 mmol·L~(-1)) and Cu/Fe ratios(0.0042 or 0.0252). It is confirmed that the formation of Fe OHCu SO_4 ternary surface complexes played an important role in enhancing Cu(Ⅱ) adsorption on HFO-CPS in the presence of sulfate.     

Nickel-Carnosine complex:A new carrier for enzymes immobilization by affinity adsorption

Immobilization is an effective method to promote the application of enzyme industry for improving the stability and realizing recovery of enzyme.To some extent,the performance of immobilized enzyme depends on the choice of carrier material.Therefore,the development of new carrier materials has been one of the key issues concerned by enzyme immobilization researchers.In this work,a novel organic-inorganic hybrid material,nickel-carnosine complex (NiCar),was synthesized for the first time by solvothermal method.The obtained NiCar exhibits spherical morphology,hierarchical porosity and abun-dant unsaturated coordination nickel ions,which provide excellent anchoring sites for the immobiliza-tion of proteins.His-tagged organophosphate-degrading enzyme (OpdA) and ω-transaminase (ω-TA)were used as model enzymes to evaluate the performance of NiCar as a carrier.By a simple adsorption process,the enzyme molecules can be fixed on the particles of NiCar,and the stability and reusability are significantly improved.The analysis of protein adsorption on NiCar verified that the affinity adsorp-tion between the imidazole functional group on the protein and the unsaturated coordination nickel ions on NiCar was the main force in the immobilization process,which provided an idea way for the develop-ment of new enzyme immobilization carriers.     

Structural Investigation and Molecular Modeling Studies of Strobilurin-Based Fungicides Active against the Rice Blast Pathogen Pyricularia oryzae

The increasing emergence of fungicide-resistant pathogens requires urgent solutions for crop disease management. Here, we describe a structural investigation of new fungicides obtained by combining strobilurin and succinate dehydrogenase inhibitor pharmacophores. We identified compounds endowed with very good activity against wild-type Pyricularia oryzae, combined in some cases with promising activity against strobilurin-resistant strains. The first three-dimensional model of P. oryzae cytochrome bc1 complex containing azoxystrobin as a ligand was developed. The model was validated with a set of commercially available strobilurins, and it well explains both the resistance mechanism to strobilurins mediated by the mutation G143A and the activity of metyltetraprole against strobilurin-resistant strains. The obtained results shed light on the key recognition determinants of strobilurin-like derivatives in the cytochrome bc1 active site and will guide the further rational design of new fungicides able to overcome resistance caused by G143A mutation in the rice blast pathogen.     

ATP-Independent Initiation during Cap-Independent Translation of m6A-Modified mRNA

The methylation of adenosine in the N⁶ position (m⁶A) is a widely used modification of eukaryotic mRNAs. Its importance for the regulation of mRNA translation was put forward recently, essentially due to the ability of methylated mRNA to be translated in conditions of inhibited cap-dependent translation initiation, e.g., under stress. However, the peculiarities of translation initiation on m⁶A-modified mRNAs are not fully known. In this study, we used toeprinting and translation in a cell-free system to confirm that m⁶A-modified mRNAs can be translated in conditions of suppressed cap-dependent translation. We show for the first time that m⁶A-modified mRNAs display not only decreased elongation, but also a lower efficiency of translation initiation. Additionally, we report relative resistance of m⁶A-mRNA translation initiation in the absence of ATP and inhibited eIF4A activity. Our novel findings indicate that the scanning of m⁶A-modified leader sequences is performed by a noncanonical mechanism.     

The Mystery of Extramitochondrial Proteins Lysine Succinylation

Lysine succinylation is a post-translational modification which alters protein function in both physiological and pathological processes. Mindful that it requires succinyl-CoA, a metabolite formed within the mitochondrial matrix that cannot permeate the inner mitochondrial membrane, the question arises as to how there can be succinylation of proteins outside mitochondria. The present mini-review examines pathways participating in peroxisomal fatty acid oxidation that lead to succinyl-CoA production, potentially supporting succinylation of extramitochondrial proteins. Furthermore, the influence of the mitochondrial status on cytosolic NAD⁺ availability affecting the activity of cytosolic SIRT5 iso1 and iso4—in turn regulating cytosolic protein lysine succinylations—is presented. Finally, the discovery that glia in the adult human brain lack subunits of both alpha-ketoglutarate dehydrogenase complex and succinate-CoA ligase—thus being unable to produce succinyl-CoA in the matrix—and yet exhibit robust pancellular lysine succinylation, is highlighted.