Testing heteroscedasticity determines whether the regression model can predict the dependent variable consistently across all values of the explanatory variables.Since the proposed tests could not detect heteroscedast...Testing heteroscedasticity determines whether the regression model can predict the dependent variable consistently across all values of the explanatory variables.Since the proposed tests could not detect heteroscedasticity in all cases,more precisely in heavy-tailed distributions,the authors established new comprehensive test statistic based on Levene’s test.The authors built the asymptotic normality of the test statistic under the null hypothesis of homoscedasticity based on the recent theory of analysis of variance for the infinite factors level.The proposed test uses the residuals from a regression model fit of the mean function with Levene’s test to assess homogeneity of variance.Simulation studies show that our test yields better than other methods in almost all cases even if the variance is a nonlinear function.Finally,the proposed method is implemented through a real data-set.展开更多
This paper considers a nonparametric diffusion process whose drift and diffusion coefficients are nonparametric functions of the state variable.A two-step approach to estimate the drift function of a jump-diffusion mo...This paper considers a nonparametric diffusion process whose drift and diffusion coefficients are nonparametric functions of the state variable.A two-step approach to estimate the drift function of a jump-diffusion model in noisy settings is proposed.The proposed estimator is shown to be consistent and asymptotically normal in the presence of finite activity jumps.Simulated experiments and a real data application are undertaken to assess the finite sample performance of the newly proposed method.展开更多
目的在中国汉族小耳畸形核心家系中评估基因新生突变模式在散发小耳畸形中的作用,寻找可能的致病性新生突变。方法选取2017年3月至2018年7月就诊于中国医学科学院整形外科医院的24个中国单纯小耳畸形核心家系。其中小耳畸形患者24例,年...目的在中国汉族小耳畸形核心家系中评估基因新生突变模式在散发小耳畸形中的作用,寻找可能的致病性新生突变。方法选取2017年3月至2018年7月就诊于中国医学科学院整形外科医院的24个中国单纯小耳畸形核心家系。其中小耳畸形患者24例,年龄6~10岁,男15例,女9例,均为单侧小耳畸形,包括左侧15例,右侧9例。获知情同意后,抽取患者及其未患病双亲的外周血,对24个单纯小耳畸形患者及其未患病双亲进行全外显子组测序,筛选位于基因编码区及经典剪接位点的新生突变,观察每例患者外显子区的新生突变数量。对筛选到的新生突变依美国医学遗传学与基因组学会变异分类标准进行分类,使用ExAc数据库、VarCards数据库、Human Splicing Finder 3.1在线软件分别对丧失功能突变、错义突变和同义突变进行变异特征判断,结合小鼠基因组信息数据库查询同源基因在小鼠鳃弓部位的表达情况、使用David6.8生物信息数据库对候选基因进行通路富集分析,使用在线人类孟德尔疾病遗传数据库查询候选基因与人类疾病之间的对应关系,从而对不同变异进行变异功能和基因功能2方面的致病性评估。结果24个小耳畸形家系中共检测到23个新生突变,每个患者检测到0~3个外显子区新生突变,与正常人相比未见明显增加。突变类型包括错义突变12个、同义突变8个以及无义突变、起始密码子突变、整码插入突变各1个。其中LRP12基因无义突变依指南分类为致病变异。使用多种生物信息学软件及数据库对所有新生突变进行分析,未见明显的致病性特征。结论小耳畸形患者中并没有发现明显的新生突变负担加重,尽管致病基因可能通过新生突变模式在小耳畸形中致病,但新生突变模式可能不是小耳畸形致病的主要遗传模式。展开更多
基金partly supported by the National Natural Science Foundation of China under Grant Nos.11571073,11701286,NSF,JS(BK20171073)
文摘Testing heteroscedasticity determines whether the regression model can predict the dependent variable consistently across all values of the explanatory variables.Since the proposed tests could not detect heteroscedasticity in all cases,more precisely in heavy-tailed distributions,the authors established new comprehensive test statistic based on Levene’s test.The authors built the asymptotic normality of the test statistic under the null hypothesis of homoscedasticity based on the recent theory of analysis of variance for the infinite factors level.The proposed test uses the residuals from a regression model fit of the mean function with Levene’s test to assess homogeneity of variance.Simulation studies show that our test yields better than other methods in almost all cases even if the variance is a nonlinear function.Finally,the proposed method is implemented through a real data-set.
基金the National Natural Science Foundation of China under Grant No.11961038Cultivating Project of National Natural Science Foundation(QianKeHe talent-development platform[2017]No.5723,QianKeHe talent-development platform[2017]No.5723-02)+7 种基金supported by the National Natural Science Foundation of China under Grant Nos.12071220,11701286supported by the National Natural Science Foundation of China under Grant Nos.11831008,11971235Young Talents Project of Science and Technology Research Program of Education Department in Guizhou Province(Qianjiao KYword[2018]364)Science and Technology Foundation of Guizhou Province(QianKeHejichu[2019]1286)Social Science Foundation of Jiangsu Province under Grant No.20EYC008the National Statistical Research Project of China under Grant No.2020LZ35the National Statistical Research Project of China under Grant No.2020LZ19Open Project of Jiangsu Key Laboratory of Financial Engineering under Grant No.NSK2021-12。
文摘This paper considers a nonparametric diffusion process whose drift and diffusion coefficients are nonparametric functions of the state variable.A two-step approach to estimate the drift function of a jump-diffusion model in noisy settings is proposed.The proposed estimator is shown to be consistent and asymptotically normal in the presence of finite activity jumps.Simulated experiments and a real data application are undertaken to assess the finite sample performance of the newly proposed method.
文摘目的在中国汉族小耳畸形核心家系中评估基因新生突变模式在散发小耳畸形中的作用,寻找可能的致病性新生突变。方法选取2017年3月至2018年7月就诊于中国医学科学院整形外科医院的24个中国单纯小耳畸形核心家系。其中小耳畸形患者24例,年龄6~10岁,男15例,女9例,均为单侧小耳畸形,包括左侧15例,右侧9例。获知情同意后,抽取患者及其未患病双亲的外周血,对24个单纯小耳畸形患者及其未患病双亲进行全外显子组测序,筛选位于基因编码区及经典剪接位点的新生突变,观察每例患者外显子区的新生突变数量。对筛选到的新生突变依美国医学遗传学与基因组学会变异分类标准进行分类,使用ExAc数据库、VarCards数据库、Human Splicing Finder 3.1在线软件分别对丧失功能突变、错义突变和同义突变进行变异特征判断,结合小鼠基因组信息数据库查询同源基因在小鼠鳃弓部位的表达情况、使用David6.8生物信息数据库对候选基因进行通路富集分析,使用在线人类孟德尔疾病遗传数据库查询候选基因与人类疾病之间的对应关系,从而对不同变异进行变异功能和基因功能2方面的致病性评估。结果24个小耳畸形家系中共检测到23个新生突变,每个患者检测到0~3个外显子区新生突变,与正常人相比未见明显增加。突变类型包括错义突变12个、同义突变8个以及无义突变、起始密码子突变、整码插入突变各1个。其中LRP12基因无义突变依指南分类为致病变异。使用多种生物信息学软件及数据库对所有新生突变进行分析,未见明显的致病性特征。结论小耳畸形患者中并没有发现明显的新生突变负担加重,尽管致病基因可能通过新生突变模式在小耳畸形中致病,但新生突变模式可能不是小耳畸形致病的主要遗传模式。
