Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from dupli...Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from duplication. As one of the six popular folds (super-folds) possessing an approximate structural symmetry, the triosephosphate isomerase barrel (TIM-barrel) domain has been widely studied. Using modified recurrent quantification analysis of primary sequences, we identified the same 2-, 3-, and 4-fold symmetry pattern as their tertiary structures. This result indicates that the symmetry in tertiary structure is coded by symmetry in the primary sequence and that the TIM-barrel adopts a 2-, 3-, or 4-fold repeat pattern during evolution. This discovery will be useful for understanding the evolutionary mechanisms of this protein family and the symmetry pattern that may be a clue into the ancient origin of duplication of half-barrels or the β a unit.展开更多
According to the method for predicting strong earthquakes using seismicity patterns,this paper summarizes the seismicity anomalies, generally called anomalous seismicity patterns,as the basis for prediction based on s...According to the method for predicting strong earthquakes using seismicity patterns,this paper summarizes the seismicity anomalies, generally called anomalous seismicity patterns,as the basis for prediction based on some historical data in the Sichuan-Yunnan seismic zone. Using our results,it can be confirmed that these anomaly patterns,which reflect the features of the late stage of strong earthquake preparation process and stress release in the main shock rupture zone,did exist before many earthquake cases. This paper also introduced the characteristics of seismic repeatability and its validation result,and discussed the mechanism of repeatability,which will have an application value for strong earthquake tendency prediction.展开更多
目的探讨短串联重复序列(short tandem repeat,STR)三带型基因座同一认定似然比(likelihood ratio,LR)的不同计算策略。方法通过忽略三带型基因座、基于人群中不同类型的观测值、基于三带型基因座形成机制推导公式三个模型,对三带型基...目的探讨短串联重复序列(short tandem repeat,STR)三带型基因座同一认定似然比(likelihood ratio,LR)的不同计算策略。方法通过忽略三带型基因座、基于人群中不同类型的观测值、基于三带型基因座形成机制推导公式三个模型,对三带型基因座似然比进行计算。结果得到三个模型六种策略的LR计算方法,并分析其保守性与局限性。结论根据三体综合征发生机制推导的三带型基因座LR计算公式,可得到较为准确且可用于司法鉴定的LR值。展开更多
文摘Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from duplication. As one of the six popular folds (super-folds) possessing an approximate structural symmetry, the triosephosphate isomerase barrel (TIM-barrel) domain has been widely studied. Using modified recurrent quantification analysis of primary sequences, we identified the same 2-, 3-, and 4-fold symmetry pattern as their tertiary structures. This result indicates that the symmetry in tertiary structure is coded by symmetry in the primary sequence and that the TIM-barrel adopts a 2-, 3-, or 4-fold repeat pattern during evolution. This discovery will be useful for understanding the evolutionary mechanisms of this protein family and the symmetry pattern that may be a clue into the ancient origin of duplication of half-barrels or the β a unit.
文摘According to the method for predicting strong earthquakes using seismicity patterns,this paper summarizes the seismicity anomalies, generally called anomalous seismicity patterns,as the basis for prediction based on some historical data in the Sichuan-Yunnan seismic zone. Using our results,it can be confirmed that these anomaly patterns,which reflect the features of the late stage of strong earthquake preparation process and stress release in the main shock rupture zone,did exist before many earthquake cases. This paper also introduced the characteristics of seismic repeatability and its validation result,and discussed the mechanism of repeatability,which will have an application value for strong earthquake tendency prediction.
文摘目的探讨短串联重复序列(short tandem repeat,STR)三带型基因座同一认定似然比(likelihood ratio,LR)的不同计算策略。方法通过忽略三带型基因座、基于人群中不同类型的观测值、基于三带型基因座形成机制推导公式三个模型,对三带型基因座似然比进行计算。结果得到三个模型六种策略的LR计算方法,并分析其保守性与局限性。结论根据三体综合征发生机制推导的三带型基因座LR计算公式,可得到较为准确且可用于司法鉴定的LR值。
