Heterogeneity of biological samples is usually considered a major obstacle for three-dimensional (3D) structure determination of macromolecular complexes. Heterogeneity may occur at the level of composition or conform...Heterogeneity of biological samples is usually considered a major obstacle for three-dimensional (3D) structure determination of macromolecular complexes. Heterogeneity may occur at the level of composition or conformational variability of complexes and affects most 3D structure determination methods that rely on signal averaging. Here, an approach is described that allows sorting structural states based on a 3D statistical approach, the 3D sampling and classification (3D-SC) of 3D structures derived from single particles imaged by cryo electron microscopy (cryo-EM). The method is based on jackknifing & bootstrapping of 3D sub-ensembles and 3D multivariate statistical analysis followed by 3D classification. The robustness of the statistical sorting procedure is corroborated using model data from an RNA polymerase structure and experimental data from a ribosome complex. It allows resolving multiple states within heterogeneous complexes that thus become amendable for a structural analysis despite of their highly flexible nature. The method has important implications for high-resolution structural studies and allows describing structure ensembles to provide insights into the dynamics of multi-component macromolecular assemblies.展开更多
Researchers have proposed several security protocols to protect the electronic commerce security in these years;however,not all of them are secure enough.This article extends model checking method with Casper/FDR2 to ...Researchers have proposed several security protocols to protect the electronic commerce security in these years;however,not all of them are secure enough.This article extends model checking method with Casper/FDR2 to model and analyze a new electronic protocol.Attacks are found in the protocol and their mechanisms are discussed.A variety of solutions are given to different security flaws.The improved protocol is proven to be robust and secure.展开更多
The objective of this paper was to analyze the impact of online reviews on sales. Based on dual path model of commodity sales, an online reviews impact on the relationship between various factors, and then the theoret...The objective of this paper was to analyze the impact of online reviews on sales. Based on dual path model of commodity sales, an online reviews impact on the relationship between various factors, and then the theoretical hypothesis of each factor has been put forward in the model. As it is intuitive and strongly supported empirically, data including Chinese texts captured from Tmall. com was utilized, and then analyzed by SPSS and ROST CM6. Our empirical study on the reviews of TmalLcom indicated that the hypotheses are verified.展开更多
文摘Heterogeneity of biological samples is usually considered a major obstacle for three-dimensional (3D) structure determination of macromolecular complexes. Heterogeneity may occur at the level of composition or conformational variability of complexes and affects most 3D structure determination methods that rely on signal averaging. Here, an approach is described that allows sorting structural states based on a 3D statistical approach, the 3D sampling and classification (3D-SC) of 3D structures derived from single particles imaged by cryo electron microscopy (cryo-EM). The method is based on jackknifing & bootstrapping of 3D sub-ensembles and 3D multivariate statistical analysis followed by 3D classification. The robustness of the statistical sorting procedure is corroborated using model data from an RNA polymerase structure and experimental data from a ribosome complex. It allows resolving multiple states within heterogeneous complexes that thus become amendable for a structural analysis despite of their highly flexible nature. The method has important implications for high-resolution structural studies and allows describing structure ensembles to provide insights into the dynamics of multi-component macromolecular assemblies.
文摘Researchers have proposed several security protocols to protect the electronic commerce security in these years;however,not all of them are secure enough.This article extends model checking method with Casper/FDR2 to model and analyze a new electronic protocol.Attacks are found in the protocol and their mechanisms are discussed.A variety of solutions are given to different security flaws.The improved protocol is proven to be robust and secure.
基金Supported by National Natural Science Foundation of China under Grant （No.61075115）, Soft Science Key issues of Shanghai Science and Technology Commission（No. 13692104900）, Innovation Program of Shanghai Municipal Education Commission （12YZ152）, Humanities and Social Science Fund of Ministry of Education （No. 13YJCZH 122） and Course Construction of SUES （No.K201203005）.
文摘The objective of this paper was to analyze the impact of online reviews on sales. Based on dual path model of commodity sales, an online reviews impact on the relationship between various factors, and then the theoretical hypothesis of each factor has been put forward in the model. As it is intuitive and strongly supported empirically, data including Chinese texts captured from Tmall. com was utilized, and then analyzed by SPSS and ROST CM6. Our empirical study on the reviews of TmalLcom indicated that the hypotheses are verified.
