Pannexin 1 channels mediate 'find-me' signal release and membrane permeability during apoptosis

Apoptotic cells release 'find-me' signals at the earliest stages of death to recruit phagocytes. The nucleotides ATP and UTP represent one class of find-me signals, but their mechanism of release is not known. Here, we identify the plasma membrane channel pannexin 1 (PANX1) as a mediator of find-me signal/nucleotide release from apoptotic cells. Pharmacological inhibition and siRNA-mediated knockdown of PANX1 led to decreased nucleotide release and monocyte recruitment by apoptotic cells. Conversely, PANX1 overexpression enhanced nucleotide release from apoptotic cells and phagocyte recruitment. Patch-clamp recordings showed that PANX1 was basally inactive, and that induction of PANX1 currents occurred only during apoptosis. Mechanistically, PANX1 itself was a target of effector caspases (caspases 3 and 7), and a specific caspase-cleavage site within PANX1 was essential for PANX1 function during apoptosis. Expression of truncated PANX1 (at the putative caspase cleavage site) resulted in a constitutively open channel. PANX1 was also important for the 'selective' plasma membrane permeability of early apoptotic cells to specific dyes. Collectively, these data identify PANX1 as a plasma membrane channel mediating the regulated release of find-me signals and selective plasma membrane permeability during apoptosis, and a new mechanism of PANX1 activation by caspases.     

S-粗决策及其F-干扰生成

针对动态决策系统具有的干扰特性和决策的不确定性,利用双向S-粗集提出了F-干扰粗决策与F-干扰粗决策规律的概念,并对F-干扰粗决策生成与F-干扰粗决策规律生成的特性进行了讨论,给出了F-干扰粗决策规律不可分辨定理与识别准则和应用.通过讨论和应用,说明利用F-干扰粗决策规律有助于在动态决策系统中分辨-识别出异常干扰,修正系统做出的决策,保证决策的安全.     

自动化变电站体系结构及其构建方式探讨

随着经济的飞速发展,电力需求也不断增长,客户对电能的质量要求也越来越高,传统的电力网络已不能满足发展的需要和客户的要求。为了更好的服务经济和社会发展,智能电网的建设可谓势不可挡。而自动化变电站作为智能电网的重要环节,不但为整个电网的安全稳定运行提供数据分析,同时也为智能电网的高效运行提供了技术方面的支持。     

整体煤气化联合循环具有孔隙率梯度的层状陶瓷过滤材料研究

陶瓷多孔过滤材料是目前整体煤气化联合循环（IGCC）最有效的过滤材料。氮化钛陶瓷过滤材料具有孔隙率高、孔结构均匀的优点,在整体煤气化联合循环领域有很好的应用前景。研究表明,采用变孔隙率梯度陶瓷过滤元件能够避免或减小陶瓷过滤元件之间的粉尘架桥现象。本文通过改变原料中氮化钛晶种、二氧化钛和碳粉的相对含量,获得了孔隙率可控的氮化钛过滤材料。以此种控制氮化钛孔隙率的工艺为基础,利用模压法制备具有孔隙率梯度的层状氮化钛过滤材料。     

基于陀螺测量信息的航天器突变参数识别方法

利用速率陀螺的测量信息研究了航天器质量特性参数突变的识别问题。基于物理学原理建立了航天器转动和速率陀螺的数学模型;对航天器的结构布局进行分析,提出了辨识策略和算法;利用条件数和奇异值分解理论对测量矩阵进行分析,观察突变参数的可辨识性及可辨识度;以某航天器为例,就其质量特性的可辨识性及可辨识度进行数值分析,并进行在轨辨识仿真。结果表明,当航天器参数突变后,按照所提的策略,其质量和质心位置可以辨识,且质心位置的可辨识度高于质量。     

非线性lp问题的极大熵方法

在非线性l1问题极大熵方法的基础上,构造了非线性l(0＜p＜1)问题的极大熵方法.为了克服lp问题的非光滑性,导出了极大熵函数,并证明了极大熵函数列的收敛性.根据同伦算法证明了极大熵函数的最优解序列逼近于非线性lp问题的最优解,并提出了解决计算过程中易于溢出的方法.最后,数值仿真表明算法是十分有效的.     

Social diversity promotes the emergence of cooperation in public goods games

Humans often cooperate in public goods games and situations ranging from family issues to global warming. However, evolutionary game theory predicts that the temptation to forgo the public good mostly wins over collective cooperative action, and this is often also seen in economic experiments. Here we show how social diversity provides an escape from this apparent paradox. Up to now, individuals have been treated as equivalent in all respects, in sharp contrast with real-life situations, where diversity is ubiquitous. We introduce social diversity by means of heterogeneous graphs and show that cooperation is promoted by the diversity associated with the number and size of the public goods game in which each individual participates and with the individual contribution to each such game. When social ties follow a scale-free distribution, cooperation is enhanced whenever all individuals are expected to contribute a fixed amount irrespective of the plethora of public goods games in which they engage. Our results may help to explain the emergence of cooperation in the absence of mechanisms based on individual reputation and punishment. Combining social diversity with reputation and punishment will provide instrumental clues on the self-organization of social communities and their economical implications.     

Accurate whole human genome sequencing using reversible terminator chemistry

DNA sequence information underpins genetic research, enabling discoveries of important biological or medical benefit. Sequencing projects have traditionally used long (400-800 base pair) reads, but the existence of reference sequences for the human and many other genomes makes it possible to develop new, fast approaches to re-sequencing, whereby shorter reads are compared to a reference to identify intraspecies genetic variation. Here we report an approach that generates several billion bases of accurate nucleotide sequence per experiment at low cost. Single molecules of DNA are attached to a flat surface, amplified in situ and used as templates for synthetic sequencing with fluorescent reversible terminator deoxyribonucleotides. Images of the surface are analysed to generate high-quality sequence. We demonstrate application of this approach to human genome sequencing on flow-sorted X chromosomes and then scale the approach to determine the genome sequence of a male Yoruba from Ibadan, Nigeria. We build an accurate consensus sequence from >30x average depth of paired 35-base reads. We characterize four million single-nucleotide polymorphisms and four hundred thousand structural variants, many of which were previously unknown. Our approach is effective for accurate, rapid and economical whole-genome re-sequencing and many other biomedical applications.