本文研究了带常利率扩散风险模型,考虑了下面的目标函数V(x,L)=E(integral from n=0 toτe^(-βt)dL_t+integral from n=0 toτe^(-βt)∧dt|R_0~L=x),这里常数∧≥0.我们称上面的表达式为T-A(Thonhauser and Albrecher)目标函数.对于...本文研究了带常利率扩散风险模型,考虑了下面的目标函数V(x,L)=E(integral from n=0 toτe^(-βt)dL_t+integral from n=0 toτe^(-βt)∧dt|R_0~L=x),这里常数∧≥0.我们称上面的表达式为T-A(Thonhauser and Albrecher)目标函数.对于常利率下的扩散模型,通过随机控制理论(HJB方程),T-A目标函数的最大化问题得以解决:对于有界分红率,最优策略是门槛策略;对于无界分红率,最优策略是边界策略.展开更多
T-A cloning takes advantage of the unpaired adenosyl residue added to the 3'terminus of amplified DNAs by Taq and other thermostable DNA polymerase and uses a Ilnearlzed plasmld vector with a protruding 3'thym...T-A cloning takes advantage of the unpaired adenosyl residue added to the 3'terminus of amplified DNAs by Taq and other thermostable DNA polymerase and uses a Ilnearlzed plasmld vector with a protruding 3'thymldylate residue at each of Its 3'termini to clone polymerase chain reaction(PCR)-derived DNA fragments.It Is a simple,reliable,and efficient Ilgatlon-dependent cloning method for PCR products,but the drawback of variable cloning efficiency occurs during application.In the present work,the relationship between variable T-A cloning efficiency and the different 5'end nucleotlde base of primers used In PCR amplification was studied.The results showed that different cloning efficiency was obtained with different primer pairs containing A,T,C and G at the 5'terminus respectively.The data shows that when the 5'end base of primer pair was adenosyl,more white colonies could be obtained In cloning the corresponding PCR product In comparison with other bases.And the least white colonies were formed when using the primer pair with 5'cytldylate end.The gluanylate end primers resulted In almost the same cloning efficiency In the white colonies amount as the thymldylate end primer did,and this efficiency was much lower than that of adenosyl end primers.This presumably is a consequence of variability In 3'dA addition to PCR products mediated by Taq polymerase.Our results offer instructions for primer design for researchers who choose T-A cloning to clone PCR products.展开更多
文摘本文研究了带常利率扩散风险模型,考虑了下面的目标函数V(x,L)=E(integral from n=0 toτe^(-βt)dL_t+integral from n=0 toτe^(-βt)∧dt|R_0~L=x),这里常数∧≥0.我们称上面的表达式为T-A(Thonhauser and Albrecher)目标函数.对于常利率下的扩散模型,通过随机控制理论(HJB方程),T-A目标函数的最大化问题得以解决:对于有界分红率,最优策略是门槛策略;对于无界分红率,最优策略是边界策略.
基金Supported by the National Natural Science Foundation of China(30671476 and 30371143)Fok Ying Tung Education Foundation(71030)Beijing Science and Technology Project(H020720110190).
文摘T-A cloning takes advantage of the unpaired adenosyl residue added to the 3'terminus of amplified DNAs by Taq and other thermostable DNA polymerase and uses a Ilnearlzed plasmld vector with a protruding 3'thymldylate residue at each of Its 3'termini to clone polymerase chain reaction(PCR)-derived DNA fragments.It Is a simple,reliable,and efficient Ilgatlon-dependent cloning method for PCR products,but the drawback of variable cloning efficiency occurs during application.In the present work,the relationship between variable T-A cloning efficiency and the different 5'end nucleotlde base of primers used In PCR amplification was studied.The results showed that different cloning efficiency was obtained with different primer pairs containing A,T,C and G at the 5'terminus respectively.The data shows that when the 5'end base of primer pair was adenosyl,more white colonies could be obtained In cloning the corresponding PCR product In comparison with other bases.And the least white colonies were formed when using the primer pair with 5'cytldylate end.The gluanylate end primers resulted In almost the same cloning efficiency In the white colonies amount as the thymldylate end primer did,and this efficiency was much lower than that of adenosyl end primers.This presumably is a consequence of variability In 3'dA addition to PCR products mediated by Taq polymerase.Our results offer instructions for primer design for researchers who choose T-A cloning to clone PCR products.
