AIM： To explore whether cyclooxygenase 2 （COX-2） -765G〉C polymorphism is associated with susceptibility of colorectal cancer （CRC） and to evaluate the risk of colorectal cancer in relation to environmental expos...AIM： To explore whether cyclooxygenase 2 （COX-2） -765G〉C polymorphism is associated with susceptibility of colorectal cancer （CRC） and to evaluate the risk of colorectal cancer in relation to environmental exposures and polymorphism. METHODS： We conducted a case-control study of 137 patients with colorectal cancer and 199 cancerfree controls in northeast China. Multivariate logistic regression analysis was performed to calculate the adjusted odds ratio （OR） and 95% confidence interval （95% CI）. RESULTS： The -765G〉C polymorphism was not independently associated with CRC risk. However, risk associated with the polymorphism differed by smoking and body mass index （BMI）. Smoking and BMI associated risks were stronger among those with -765GG genotype, showing that smokers had a 2.682-fold greater risk of CRC than nonsmokers （51/43 vs 68/126, P = 0.006）. Compared to those with a normal body mass index （BMI 18.5-22.9）, those with overweight （BMI 23-24.9） had a 3.909-fold higher risk of CRC （OR = 3.909, 95% CI = 2.081-7.344; P 〈 0.001）, while those with obesity （BMI 〉 25） had a 2.031- fold higher risk of CRC （OR = 1.107, 95% CI = 1.107-3.726; P = 0.022）. is not associated with an increased risk of CRC, -765GG genotype appears to be related to an increased risk in the presence of smoking and higher BMI.展开更多
There has been a growing interest in mathematical models to character the evolutionary algorithms. The best-known one of such models is the axiomatic model colled the abstract evolutionary algorithm. In this paper, we...There has been a growing interest in mathematical models to character the evolutionary algorithms. The best-known one of such models is the axiomatic model colled the abstract evolutionary algorithm. In this paper, we first introduce the definitions of the abhstract selection and evolution operators, and that of the abstract evolutionary algorithm, which describes the evolution as an abstract stochastic process composed of these two fundamental abstract operators. In particular, a kind of abstract evolutionary algorithms based on a special selection mechansim is discussed. According to the sorting for the state space, the properties of the single step transition matrix for the algorithm are anaylzed. In the end, we prove that the limit probability distribution of the Markov chains exists. The present work provides a big step toward the establishment of a unified theory of evolutionary computation.展开更多
基金Program for New Century Excellent Talents fromUniversity,No.NCET-06-0296
文摘AIM： To explore whether cyclooxygenase 2 （COX-2） -765G〉C polymorphism is associated with susceptibility of colorectal cancer （CRC） and to evaluate the risk of colorectal cancer in relation to environmental exposures and polymorphism. METHODS： We conducted a case-control study of 137 patients with colorectal cancer and 199 cancerfree controls in northeast China. Multivariate logistic regression analysis was performed to calculate the adjusted odds ratio （OR） and 95% confidence interval （95% CI）. RESULTS： The -765G〉C polymorphism was not independently associated with CRC risk. However, risk associated with the polymorphism differed by smoking and body mass index （BMI）. Smoking and BMI associated risks were stronger among those with -765GG genotype, showing that smokers had a 2.682-fold greater risk of CRC than nonsmokers （51/43 vs 68/126, P = 0.006）. Compared to those with a normal body mass index （BMI 18.5-22.9）, those with overweight （BMI 23-24.9） had a 3.909-fold higher risk of CRC （OR = 3.909, 95% CI = 2.081-7.344; P 〈 0.001）, while those with obesity （BMI 〉 25） had a 2.031- fold higher risk of CRC （OR = 1.107, 95% CI = 1.107-3.726; P = 0.022）. is not associated with an increased risk of CRC, -765GG genotype appears to be related to an increased risk in the presence of smoking and higher BMI.
基金Supported by the National Science Foundation of China(60133010)Supported by the Science Foundation of Henan Province(2000110019)
文摘There has been a growing interest in mathematical models to character the evolutionary algorithms. The best-known one of such models is the axiomatic model colled the abstract evolutionary algorithm. In this paper, we first introduce the definitions of the abhstract selection and evolution operators, and that of the abstract evolutionary algorithm, which describes the evolution as an abstract stochastic process composed of these two fundamental abstract operators. In particular, a kind of abstract evolutionary algorithms based on a special selection mechansim is discussed. According to the sorting for the state space, the properties of the single step transition matrix for the algorithm are anaylzed. In the end, we prove that the limit probability distribution of the Markov chains exists. The present work provides a big step toward the establishment of a unified theory of evolutionary computation.
