In the history of Chinese-American people-to-people exchange,the implementation of the China-U.S.Fulbright Program is surely a bright facet which should not be ignored.This program has been cultivating talents in the ...In the history of Chinese-American people-to-people exchange,the implementation of the China-U.S.Fulbright Program is surely a bright facet which should not be ignored.This program has been cultivating talents in the fields of social sciences and humanities for the two countries,promoting Sino-U.S.communications in the domains of education,academia and culture,and propelling the diffusion and advance of both Chinese and American cultures.The Fulbright Program in China still has certain limitations waiting to be improved,and one obvious problem is its coverage in China.To solve this problem,more Chinese higher education institutions should be included in the China-U.S.Fulbright Program,and the result would be the generation of immeasurable value for the prosperity of Sino-American people-to-people exchange and therefore the construction of the new model of major country relations between China and the United States.展开更多
The paper presents an analysis of computer programming languages based on the semiotics of Charles S. Peirce. The author describes how such languages could evolve in order to achieve some of the expressive characteris...The paper presents an analysis of computer programming languages based on the semiotics of Charles S. Peirce. The author describes how such languages could evolve in order to achieve some of the expressive characteristics of natural languages. This description evinces otherwise unnoticed differences between natural languages and programming languages, showing that Peircean semiotics is an efficient analysis tool. This suggests further research on the technical features needed to implement an easier way to program computers.展开更多
A class of functions called quasi B s invex and pseudo B s invex functions are introduced by using the concept of symmetric gradient. The examples of quasi B s invex and pseudo B s invex functions are given. The suffi...A class of functions called quasi B s invex and pseudo B s invex functions are introduced by using the concept of symmetric gradient. The examples of quasi B s invex and pseudo B s invex functions are given. The sufficient optimality conditions and Mond Weir type duality results are obtained for a nondifferentiable nonlinear semi infinite programming problem involving quasi B s invex and pseudo B s invex functions.展开更多
To study gene control mechanisms in Xenopus embryos, we analyzed polyamines, cloned SAMDC (S-adenosylmethionine decarboxylase), a key enzyme of polyamine metabolism, and microinjected its mRNA into Xenopus fertilized ...To study gene control mechanisms in Xenopus embryos, we analyzed polyamines, cloned SAMDC (S-adenosylmethionine decarboxylase), a key enzyme of polyamine metabolism, and microinjected its mRNA into Xenopus fertilized eggs. The microinjection induced a large increase in SAMDC activity, exhaustion of the substrate SAM (S-adenosylmethionine), and execution of apoptosis at the stage called midblastula transition (MBT). By tracing GFP (green fluorescence protein)-marked apoptotic cells, we reached a conclusion that the apoptosis provides pre-blastula embryos with a fail-safe mechanism of early development. We analyzed caspase mRNAs and found that caspase-9 and -3 mRNAs are maternal mRNA and activation of caspase-9 is one of the key steps for the execution of the apoptosis. We also found that over- expression of caspase-8, and in addition p53, a tumor suppressor protein, also induces apoptosis at MBT, just like the overexpression of SAMDC and caspase-9 does. The apoptosis induced by p53 was suppressed by Xdm-2, a negative regulator of p53, and by a peptide inhibitor and a dominant-negative type mutant of caspase-9, but not by those of caspase-8. By contrast, apoptosis induced by SAMDC was suppressed by peptide inhibitors and dominant-negative mutants of both caspase-9 and caspase-8, but not by Xdm-2. Unlike caspase-9 mRNA, caspase-8 mRNA was not a maternal mRNA, but newly expressed during cleavage stage (pre-MBT stage) only in embryos overexpressed with SAMDC. In SAMDC-induced apoptotic embryos activities to process procaspase-8 and procaspase-9 appeared, whereas in p53-induced apoptotic embryos only activity to process procaspase-9 appeared. Thus, Xenopus embryos have at least two pathways to execute the maternal program of apoptosis: One induced by SAMDC overexpression through activation of caspase-9 and do novo expression of caspase-8 gene, and the other induced by p53 overexpression through activation of caspase-9 but not caspase-8. In Xenopus embryos, it has long been believed that zygotic genes are silent until MBT, but results obtained with caspase-8 may provide a novel example of gene expression before MBT.展开更多
This paper intends to investigate the urban spatial patterns of Hubei Province and its evolution from three different perspectives: urban nodes, urban connections and urban clusters. The research adopts nighttime ligh...This paper intends to investigate the urban spatial patterns of Hubei Province and its evolution from three different perspectives: urban nodes, urban connections and urban clusters. The research adopts nighttime light imagery of cities in Hubei Province, the viewpoint of ′point-axis-area′ in the ′point-axis system′ theory, and employs light index model, gravity model and social network analysis. The findings are as follows: 1) In terms of urban nodes, the urbanization process of Hubei has been carried out mainly on the basis of external expansion rather than internal increasing. The polarization trend of urban connection network is strengthening. 2) As for urban connections, the estimation of urban connections using light index model is capable of containing various actual flow, and the connections are getting increasingly closer. 3) In regard to urban groups, seven urban groups of varying sizes have formed. On that basis, three stable and relatively independent urban groups as the centers, namely Wuchang, Yichang and Xiangyang emerge as well. But the structures of ′Wuhan Metropolitan Area′, ′Yichang-Jingzhou-Jingmen City Group′ and ′Xiangyang-Shiyen-Suizhou City Group′, which are defined by local development strategy in Hubei Province, are different from the above three urban groups.展开更多
文摘In the history of Chinese-American people-to-people exchange,the implementation of the China-U.S.Fulbright Program is surely a bright facet which should not be ignored.This program has been cultivating talents in the fields of social sciences and humanities for the two countries,promoting Sino-U.S.communications in the domains of education,academia and culture,and propelling the diffusion and advance of both Chinese and American cultures.The Fulbright Program in China still has certain limitations waiting to be improved,and one obvious problem is its coverage in China.To solve this problem,more Chinese higher education institutions should be included in the China-U.S.Fulbright Program,and the result would be the generation of immeasurable value for the prosperity of Sino-American people-to-people exchange and therefore the construction of the new model of major country relations between China and the United States.
文摘The paper presents an analysis of computer programming languages based on the semiotics of Charles S. Peirce. The author describes how such languages could evolve in order to achieve some of the expressive characteristics of natural languages. This description evinces otherwise unnoticed differences between natural languages and programming languages, showing that Peircean semiotics is an efficient analysis tool. This suggests further research on the technical features needed to implement an easier way to program computers.
基金the Natural Science Foundation of Shaanxi Province and the Science Foundation of Shaanxi Provincial Educational CommitteeP.R.China
文摘A class of functions called quasi B s invex and pseudo B s invex functions are introduced by using the concept of symmetric gradient. The examples of quasi B s invex and pseudo B s invex functions are given. The sufficient optimality conditions and Mond Weir type duality results are obtained for a nondifferentiable nonlinear semi infinite programming problem involving quasi B s invex and pseudo B s invex functions.
文摘To study gene control mechanisms in Xenopus embryos, we analyzed polyamines, cloned SAMDC (S-adenosylmethionine decarboxylase), a key enzyme of polyamine metabolism, and microinjected its mRNA into Xenopus fertilized eggs. The microinjection induced a large increase in SAMDC activity, exhaustion of the substrate SAM (S-adenosylmethionine), and execution of apoptosis at the stage called midblastula transition (MBT). By tracing GFP (green fluorescence protein)-marked apoptotic cells, we reached a conclusion that the apoptosis provides pre-blastula embryos with a fail-safe mechanism of early development. We analyzed caspase mRNAs and found that caspase-9 and -3 mRNAs are maternal mRNA and activation of caspase-9 is one of the key steps for the execution of the apoptosis. We also found that over- expression of caspase-8, and in addition p53, a tumor suppressor protein, also induces apoptosis at MBT, just like the overexpression of SAMDC and caspase-9 does. The apoptosis induced by p53 was suppressed by Xdm-2, a negative regulator of p53, and by a peptide inhibitor and a dominant-negative type mutant of caspase-9, but not by those of caspase-8. By contrast, apoptosis induced by SAMDC was suppressed by peptide inhibitors and dominant-negative mutants of both caspase-9 and caspase-8, but not by Xdm-2. Unlike caspase-9 mRNA, caspase-8 mRNA was not a maternal mRNA, but newly expressed during cleavage stage (pre-MBT stage) only in embryos overexpressed with SAMDC. In SAMDC-induced apoptotic embryos activities to process procaspase-8 and procaspase-9 appeared, whereas in p53-induced apoptotic embryos only activity to process procaspase-9 appeared. Thus, Xenopus embryos have at least two pathways to execute the maternal program of apoptosis: One induced by SAMDC overexpression through activation of caspase-9 and do novo expression of caspase-8 gene, and the other induced by p53 overexpression through activation of caspase-9 but not caspase-8. In Xenopus embryos, it has long been believed that zygotic genes are silent until MBT, but results obtained with caspase-8 may provide a novel example of gene expression before MBT.
基金Under the auspices of National Natural Science Foundation of China(No.41001100,41371183)Humanities and Social Sciences Foundation of Ministry of Education in China(No.15YJCZH174)+1 种基金Humanities Sciences Foundation of Ministry of Hubei Province(No.15YJCZH174)Fundamental Research Funds for the Central Universities(No.CCNU15A06069,CCNU15ZD001)
文摘This paper intends to investigate the urban spatial patterns of Hubei Province and its evolution from three different perspectives: urban nodes, urban connections and urban clusters. The research adopts nighttime light imagery of cities in Hubei Province, the viewpoint of ′point-axis-area′ in the ′point-axis system′ theory, and employs light index model, gravity model and social network analysis. The findings are as follows: 1) In terms of urban nodes, the urbanization process of Hubei has been carried out mainly on the basis of external expansion rather than internal increasing. The polarization trend of urban connection network is strengthening. 2) As for urban connections, the estimation of urban connections using light index model is capable of containing various actual flow, and the connections are getting increasingly closer. 3) In regard to urban groups, seven urban groups of varying sizes have formed. On that basis, three stable and relatively independent urban groups as the centers, namely Wuchang, Yichang and Xiangyang emerge as well. But the structures of ′Wuhan Metropolitan Area′, ′Yichang-Jingzhou-Jingmen City Group′ and ′Xiangyang-Shiyen-Suizhou City Group′, which are defined by local development strategy in Hubei Province, are different from the above three urban groups.
