Dissimilar to traditional networks, the features of mobile wireless devices that can actively form a network without any infrastructure mean that mobile ad hoc networks frequently display partition due to node mobilit...Dissimilar to traditional networks, the features of mobile wireless devices that can actively form a network without any infrastructure mean that mobile ad hoc networks frequently display partition due to node mobility or link failures. These indicate that an ad hoc network is difficult to provide ou-llne access to a trusted authority server. Therefore, applying traditional Public Key Infrastructure （PKI） security framework to mobile ad hoc networks will cause insecurities. This study proposes a scalable and elastic key management scheme integrated into Cluster Based Secure Routing Protocol （CBSRP） to enhance security and non-repudiation of routing authentication, and introduces an ID-Based internal routing authentication scheme to enhance the routing performance in an internal cluster. Additionally, a method of performing routing authentication between internal and external clusters, as well as inter-cluster routing authentication, is developed. The proposed cluster-based key management scheme distributes trust to an aggregation of cluster heads using a threshold scheme faculty, provides Certificate Authority （CA） with a fault tolerance mechanism to prevent a single point of compromise or failure, and saves CA large repositories from maintaining member certificates, making ad hoc networks robust to malicious behaviors and suitable for numerous mobile devices.展开更多
目的应用成簇规律间隔短回文重复序列(clustered regularly inter-spaced short palindromic repeats,CRISPR)基因分型方法,对乌兰县分离鼠疫菌株进行CRISPR基因分型分析,以了解该地区鼠疫菌CRISPR类群和基因型。方法复苏培养乌兰县1966...目的应用成簇规律间隔短回文重复序列(clustered regularly inter-spaced short palindromic repeats,CRISPR)基因分型方法,对乌兰县分离鼠疫菌株进行CRISPR基因分型分析,以了解该地区鼠疫菌CRISPR类群和基因型。方法复苏培养乌兰县1966—2010年取自鼠疫患者、媒介昆虫和喜马拉雅旱獭的63株原始鼠疫菌株,提取其DNA,设计CRISPR的YPa、YPb、YPc 3个位点引物,利用PCR技术,对以上位点进行扩增,测定其扩增产物核酸序列并进行综合分析,将测得的CRISPR序列与文献最新报道的CRISPR Dictionary和美国国立生物技术信息中心(National Center for Biotechnology Information,NCBI)数据库进行比对,探索是否存在之前未出现的CRISPR间隔(spacer)类群和基因型别,分析菌株间可能的进化关系,最终确定乌兰县喜马拉雅旱獭鼠疫自然疫源地鼠疫菌菌株的CRISPR基因库。结果63株鼠疫菌在3个CRISPR位点上共有16种spacer,其中YPa位点9种、YPb位点4种、YPc位点3种。63株鼠疫菌可被分为6个基因型,分别为G26-a1′、G26-a1′a4^(-)、G22-a4^(-)、G22、G22-a1′a4^(-)、G7,归为4大CRISPR类群,分别为Ca35′、Ca7、Ca7′、Cb4。Ca35′是该地区主要流行类群;Ca7和Ca7′分布在乌兰县东部的铜普镇和茶卡镇;Cb4仅存在于赛什克地区。结论青海省乌兰县鼠疫菌种群结构相对稳定,以Ca35′为主要种群,G26-a1′型为主要基因型,呈现显著的地区聚集特征,今后可以利用CRISPR基因分型技术加强该地区鼠疫溯源检测和防控工作。展开更多
文摘Dissimilar to traditional networks, the features of mobile wireless devices that can actively form a network without any infrastructure mean that mobile ad hoc networks frequently display partition due to node mobility or link failures. These indicate that an ad hoc network is difficult to provide ou-llne access to a trusted authority server. Therefore, applying traditional Public Key Infrastructure （PKI） security framework to mobile ad hoc networks will cause insecurities. This study proposes a scalable and elastic key management scheme integrated into Cluster Based Secure Routing Protocol （CBSRP） to enhance security and non-repudiation of routing authentication, and introduces an ID-Based internal routing authentication scheme to enhance the routing performance in an internal cluster. Additionally, a method of performing routing authentication between internal and external clusters, as well as inter-cluster routing authentication, is developed. The proposed cluster-based key management scheme distributes trust to an aggregation of cluster heads using a threshold scheme faculty, provides Certificate Authority （CA） with a fault tolerance mechanism to prevent a single point of compromise or failure, and saves CA large repositories from maintaining member certificates, making ad hoc networks robust to malicious behaviors and suitable for numerous mobile devices.
文摘目的应用成簇规律间隔短回文重复序列(clustered regularly inter-spaced short palindromic repeats,CRISPR)基因分型方法,对乌兰县分离鼠疫菌株进行CRISPR基因分型分析,以了解该地区鼠疫菌CRISPR类群和基因型。方法复苏培养乌兰县1966—2010年取自鼠疫患者、媒介昆虫和喜马拉雅旱獭的63株原始鼠疫菌株,提取其DNA,设计CRISPR的YPa、YPb、YPc 3个位点引物,利用PCR技术,对以上位点进行扩增,测定其扩增产物核酸序列并进行综合分析,将测得的CRISPR序列与文献最新报道的CRISPR Dictionary和美国国立生物技术信息中心(National Center for Biotechnology Information,NCBI)数据库进行比对,探索是否存在之前未出现的CRISPR间隔(spacer)类群和基因型别,分析菌株间可能的进化关系,最终确定乌兰县喜马拉雅旱獭鼠疫自然疫源地鼠疫菌菌株的CRISPR基因库。结果63株鼠疫菌在3个CRISPR位点上共有16种spacer,其中YPa位点9种、YPb位点4种、YPc位点3种。63株鼠疫菌可被分为6个基因型,分别为G26-a1′、G26-a1′a4^(-)、G22-a4^(-)、G22、G22-a1′a4^(-)、G7,归为4大CRISPR类群,分别为Ca35′、Ca7、Ca7′、Cb4。Ca35′是该地区主要流行类群;Ca7和Ca7′分布在乌兰县东部的铜普镇和茶卡镇;Cb4仅存在于赛什克地区。结论青海省乌兰县鼠疫菌种群结构相对稳定,以Ca35′为主要种群,G26-a1′型为主要基因型,呈现显著的地区聚集特征,今后可以利用CRISPR基因分型技术加强该地区鼠疫溯源检测和防控工作。
