Since the 2009 pandemic H1N1 swine-origin influenza A virus (09 S-OIV) has reminded the world about the global threat of the ever changing influenza virus,many questions regarding the detailed re-assortment of influen...Since the 2009 pandemic H1N1 swine-origin influenza A virus (09 S-OIV) has reminded the world about the global threat of the ever changing influenza virus,many questions regarding the detailed re-assortment of influenza viruses yet remain unanswered.Influenza A virus is the causative agent of the pandemic flu and contains 2 major antigenic glycoproteins on its surface:(i) hemagglutinin (HA);and (ii) neuraminidase (NA).The structures of the 09 S-OIV HA and NA proteins (09H1 and 09N1) have recently been resolved in our laboratory and provide some clues as to why the 09 S-OIV re-assortment virus is highly infectious with severe consequences in humans.For example,the 09H1 is highly similar to the HA of the 1918 influenza A pandemic virus in overall structure and especially in regards to its 5 defined antibody binding epitopes.For 09N1,its most distinctive feature is the lack of a 150-loop active site cavity,which was previously predicted to be present in all N1 NAs,and we hypothesize that the 150-loop may play a important role in the substrate specificity (α2,3 or α2,6 linked sialic acid receptors) and enzymatic mechanism of influenza NA.Combination of the HA and NA with special characteristics for the 09 S-OIV might contribute to its high increased transmissibility in humans.展开更多
Equivalent simplification is an effective method for solving large-scale complex problems. In this paper, the authors simplify a classic project scheduling problem, which is the nonlinear continuous time-cost tradeoff...Equivalent simplification is an effective method for solving large-scale complex problems. In this paper, the authors simplify a classic project scheduling problem, which is the nonlinear continuous time-cost tradeoff problem(TCTP). Simplifying TCTP is a simple path problem in a critical path method(CPM) network. The authors transform TCTP into a simple activity float problem and design a complex polynomial algorithm for its solution. First, the authors discover relationships between activity floats and path lengths by studying activity floats from the perspective of path instead of time.Second, the authors perform simplification and improve the efficiency and accuracy of the solution by deleting redundant activities and narrowing the duration intervals of non-redundant activities. Finally,the authors compare our method with current methods. The relationships between activity floats and path lengths provide new approaches for other path and correlative project problems.展开更多
基金supported by Chinese Academy of Sciences Research Fellowship for Young International Scientists (2010Y2SB12)the National Natural Science Foundation of China for International Young Scientists (31050110126) to Vavricka CJthe National Natural Science Foundation of China (81021003) to Gao GF
文摘Since the 2009 pandemic H1N1 swine-origin influenza A virus (09 S-OIV) has reminded the world about the global threat of the ever changing influenza virus,many questions regarding the detailed re-assortment of influenza viruses yet remain unanswered.Influenza A virus is the causative agent of the pandemic flu and contains 2 major antigenic glycoproteins on its surface:(i) hemagglutinin (HA);and (ii) neuraminidase (NA).The structures of the 09 S-OIV HA and NA proteins (09H1 and 09N1) have recently been resolved in our laboratory and provide some clues as to why the 09 S-OIV re-assortment virus is highly infectious with severe consequences in humans.For example,the 09H1 is highly similar to the HA of the 1918 influenza A pandemic virus in overall structure and especially in regards to its 5 defined antibody binding epitopes.For 09N1,its most distinctive feature is the lack of a 150-loop active site cavity,which was previously predicted to be present in all N1 NAs,and we hypothesize that the 150-loop may play a important role in the substrate specificity (α2,3 or α2,6 linked sialic acid receptors) and enzymatic mechanism of influenza NA.Combination of the HA and NA with special characteristics for the 09 S-OIV might contribute to its high increased transmissibility in humans.
基金supported by the Science and Technology Foundation of Jiangxi Provincial Department of Education in China under Grant No.GJJ161114the Natural Science Foundation of China under Grant No.71271081the Soft Science Research Base of Water Security and Sustainable Development of Jiangxi Province in China
文摘Equivalent simplification is an effective method for solving large-scale complex problems. In this paper, the authors simplify a classic project scheduling problem, which is the nonlinear continuous time-cost tradeoff problem(TCTP). Simplifying TCTP is a simple path problem in a critical path method(CPM) network. The authors transform TCTP into a simple activity float problem and design a complex polynomial algorithm for its solution. First, the authors discover relationships between activity floats and path lengths by studying activity floats from the perspective of path instead of time.Second, the authors perform simplification and improve the efficiency and accuracy of the solution by deleting redundant activities and narrowing the duration intervals of non-redundant activities. Finally,the authors compare our method with current methods. The relationships between activity floats and path lengths provide new approaches for other path and correlative project problems.
