The human gastrointestinal （GI） tract is colonized by non-pathogenic commensal microflora and frequently exposed to many pathogenic organisms. For the maintenance of GI homeostasis, the host must discriminate betwee...The human gastrointestinal （GI） tract is colonized by non-pathogenic commensal microflora and frequently exposed to many pathogenic organisms. For the maintenance of GI homeostasis, the host must discriminate between pathogenic and non-pathogenic organisms and initiate effective and appropriate immune and inflammatory responses. Mammalian tolllike receptors （TLRs） are members of the patternrecognition receptor （PRR） family that plays a central role in the initiation of innate cellular immune responses and the subsequent adaptive immune responses to microbial pathogens. Recent studies have shown that gastrointestinal epithelial cells express almost all TLR subtypes characterized to date and that the expression and activation of TLRs in the GI tract are tightly and coordinately regulated. This review summarizes the current understanding of the crucial dual roles of TLRs in the development of host innate and adaptive immune responses to GI infections and the maintenance of the immune tolerance to commensal bacteria through downregulation of surface expression of TLRs in intestinal epithelial cells.展开更多
In this context, we believe that the sun sports research now focuses on the meaning and value of sports sunshine, sunshine sports meaning and identity, how to develop the Sunshine Sports and other issues. These studie...In this context, we believe that the sun sports research now focuses on the meaning and value of sports sunshine, sunshine sports meaning and identity, how to develop the Sunshine Sports and other issues. These studies contributed to the development of sports sunshine, but there is also a lack of rigorous logical theory discussed, and the lack of institutional mechanisms for research, such as lack of a single research methods. Strengthening sunshine sports promotion model, the development of long-term mechanism research, both theoretical study sports sunshine depth development needs, but also a necessary requirement for the development of Sunshine Sports. In order to effectively promote the College “sunshine sports” to carry out and improve the physical health of college students, the use of literature, interviews, statistics and other research methods, sports curriculum University under the “sunshine sports” Perspectives issues the study. Sunshine Sports is a strong push forward by the Chinese government, the students physical health of government intervention measures. Activities three years, in all types of schools at all levels to actively carry out an hour a day exercise, teachers and students to participate in sports initiative, growing consciousness, awareness and physical exercise generally improved, exercise one hour a day has become common practice. But in some places there is still not know the place, lack of investment, lack of teachers and other issues, in order to make sustainable development the sun sports, will take in institution building, reform the examination and evaluation mechanisms, strengthening supervision and so do efforts.展开更多
To deeply understand the emergence of cooperation in natural,social and economical systems,we present an improved fitness evaluation mechanism with memory in spatial prisoner's dilemma game on regular lattices.In ...To deeply understand the emergence of cooperation in natural,social and economical systems,we present an improved fitness evaluation mechanism with memory in spatial prisoner's dilemma game on regular lattices.In our model,the individual fitness is not only determined by the payoff in the current game round,but also by the payoffs in previous round bins.A tunable parameter,termed as the memory strength(μ),which lies between 0 and 1,is introduced into the model to regulate the ratio of payoffs of current and previous game rounds in the individual fitness calculation.When μ = 0,our model is reduced to the standard prisoner's dilemma game;while μ = 1 represents the case in which the payoff is totally determined by the initial strategies and thus it is far from the realistic ones.Extensive numerical simulations indicate that the memory effect can substantially promote the evolution of cooperation.For μ < 1,the stronger the memory effect,the higher the cooperation level,but μ = 1 leads to a pathological state of cooperation,but can partially enhance the cooperation in the very large temptation parameter.The current results are of great significance for us to account for the role of memory effect during the evolution of cooperation among selfish players.展开更多
基金Supported by the National Research Council Canada and the National Institutes of Health, United States
文摘The human gastrointestinal （GI） tract is colonized by non-pathogenic commensal microflora and frequently exposed to many pathogenic organisms. For the maintenance of GI homeostasis, the host must discriminate between pathogenic and non-pathogenic organisms and initiate effective and appropriate immune and inflammatory responses. Mammalian tolllike receptors （TLRs） are members of the patternrecognition receptor （PRR） family that plays a central role in the initiation of innate cellular immune responses and the subsequent adaptive immune responses to microbial pathogens. Recent studies have shown that gastrointestinal epithelial cells express almost all TLR subtypes characterized to date and that the expression and activation of TLRs in the GI tract are tightly and coordinately regulated. This review summarizes the current understanding of the crucial dual roles of TLRs in the development of host innate and adaptive immune responses to GI infections and the maintenance of the immune tolerance to commensal bacteria through downregulation of surface expression of TLRs in intestinal epithelial cells.
文摘In this context, we believe that the sun sports research now focuses on the meaning and value of sports sunshine, sunshine sports meaning and identity, how to develop the Sunshine Sports and other issues. These studies contributed to the development of sports sunshine, but there is also a lack of rigorous logical theory discussed, and the lack of institutional mechanisms for research, such as lack of a single research methods. Strengthening sunshine sports promotion model, the development of long-term mechanism research, both theoretical study sports sunshine depth development needs, but also a necessary requirement for the development of Sunshine Sports. In order to effectively promote the College “sunshine sports” to carry out and improve the physical health of college students, the use of literature, interviews, statistics and other research methods, sports curriculum University under the “sunshine sports” Perspectives issues the study. Sunshine Sports is a strong push forward by the Chinese government, the students physical health of government intervention measures. Activities three years, in all types of schools at all levels to actively carry out an hour a day exercise, teachers and students to participate in sports initiative, growing consciousness, awareness and physical exercise generally improved, exercise one hour a day has become common practice. But in some places there is still not know the place, lack of investment, lack of teachers and other issues, in order to make sustainable development the sun sports, will take in institution building, reform the examination and evaluation mechanisms, strengthening supervision and so do efforts.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 61203138,60904063Innovation Fund for Technology Based Firms in Tianjin
文摘To deeply understand the emergence of cooperation in natural,social and economical systems,we present an improved fitness evaluation mechanism with memory in spatial prisoner's dilemma game on regular lattices.In our model,the individual fitness is not only determined by the payoff in the current game round,but also by the payoffs in previous round bins.A tunable parameter,termed as the memory strength(μ),which lies between 0 and 1,is introduced into the model to regulate the ratio of payoffs of current and previous game rounds in the individual fitness calculation.When μ = 0,our model is reduced to the standard prisoner's dilemma game;while μ = 1 represents the case in which the payoff is totally determined by the initial strategies and thus it is far from the realistic ones.Extensive numerical simulations indicate that the memory effect can substantially promote the evolution of cooperation.For μ < 1,the stronger the memory effect,the higher the cooperation level,but μ = 1 leads to a pathological state of cooperation,but can partially enhance the cooperation in the very large temptation parameter.The current results are of great significance for us to account for the role of memory effect during the evolution of cooperation among selfish players.
