Due to technical difficulties,the genetic transformation of mitochondria in mammalian cells is still a challenge.In this report,we described our attempts to transform mammalian mitochondria with an engineered mitochon...Due to technical difficulties,the genetic transformation of mitochondria in mammalian cells is still a challenge.In this report,we described our attempts to transform mammalian mitochondria with an engineered mitochondrial genome based on selection using a drug resistance gene.Because the standard drug-resistant neomycin phosphotransferase confers resistance to high concentrations of G418 when targeted to the mitochondria,we generated a recoded neomycin resistance gene that uses the mammalian mitochondrial genetic code to direct the synthesis of this protein in the mitochondria,but not in the nucleus（mitochondrial version）.We also generated a universal version of the recoded neomycin resistance gene that allows synthesis of the drug-resistant proteins both in the mitochondria and nucleus.When we transfected these recoded neomycin resistance genes that were incorporated into the mouse mitochondrial genome clones into mouse tissue culture cells by electroporation,no DNA constructs were delivered into the mitochondria.We found that the universal version of the recoded neomycin resistance gene was expressed in the nucleus and thus conferred drug resistance to G418 selection,while the synthetic mitochondrial version of the gene produced no background drug-resistant cells from nuclear transformation.These recoded synthetic drug-resistant genes could be a useful tool for selecting mitochondrial genetic transformants as a precise technology for mitochondrial transformation is developed.展开更多
This paper introduces the design thought of the Chinese Worlds Auto-coding Tool (CWAT) and its realizing algorthm. It discusses the principles of construction database and the technique of increasing the speed of reco...This paper introduces the design thought of the Chinese Worlds Auto-coding Tool (CWAT) and its realizing algorthm. It discusses the principles of construction database and the technique of increasing the speed of record searching in the CWAT. And then, the paper analyses the functions and the algouithms of the EWAT.展开更多
提出一种基于(7,4)汉明码纠错机制的抗视频帧操作的帧定位算法,可通过识别含水印帧来提取受到帧操作攻击的水印信息.首先利用改进的简单线性迭代聚类(simple linear iterative clustering,SLIC)超像素分割算法提取视频帧的固有特征X,这...提出一种基于(7,4)汉明码纠错机制的抗视频帧操作的帧定位算法,可通过识别含水印帧来提取受到帧操作攻击的水印信息.首先利用改进的简单线性迭代聚类(simple linear iterative clustering,SLIC)超像素分割算法提取视频帧的固有特征X,这里X是一串7位的0-1序列,是由SLIC超像素分割算法通过预处理、量化等运算得到的聚类中心.将视频帧的固有特征X与汉明码结合形成一个特殊的编码S.以编码S为定位码,利用(7,4)汉明码的纠错机制修改1位可隐藏3位的性能来实现定位码的标识,再基于DCT-SVD(discrete cosine transformation-singular value decomposition)分解将水印信息嵌入到含定位标识的视频中.实验结果表明,该算法不仅能抵抗帧删除、帧添加和重编码等攻击,也能抵抗常见的信号处理操作.展开更多
基金Minnesota Medical Foundation, the Academic Health Center, the Institute of Human Genetics of the University of Minnesota and the National Institute of Health for their generous financial support (NS052612).
文摘Due to technical difficulties,the genetic transformation of mitochondria in mammalian cells is still a challenge.In this report,we described our attempts to transform mammalian mitochondria with an engineered mitochondrial genome based on selection using a drug resistance gene.Because the standard drug-resistant neomycin phosphotransferase confers resistance to high concentrations of G418 when targeted to the mitochondria,we generated a recoded neomycin resistance gene that uses the mammalian mitochondrial genetic code to direct the synthesis of this protein in the mitochondria,but not in the nucleus（mitochondrial version）.We also generated a universal version of the recoded neomycin resistance gene that allows synthesis of the drug-resistant proteins both in the mitochondria and nucleus.When we transfected these recoded neomycin resistance genes that were incorporated into the mouse mitochondrial genome clones into mouse tissue culture cells by electroporation,no DNA constructs were delivered into the mitochondria.We found that the universal version of the recoded neomycin resistance gene was expressed in the nucleus and thus conferred drug resistance to G418 selection,while the synthetic mitochondrial version of the gene produced no background drug-resistant cells from nuclear transformation.These recoded synthetic drug-resistant genes could be a useful tool for selecting mitochondrial genetic transformants as a precise technology for mitochondrial transformation is developed.
文摘This paper introduces the design thought of the Chinese Worlds Auto-coding Tool (CWAT) and its realizing algorthm. It discusses the principles of construction database and the technique of increasing the speed of record searching in the CWAT. And then, the paper analyses the functions and the algouithms of the EWAT.
文摘提出一种基于(7,4)汉明码纠错机制的抗视频帧操作的帧定位算法,可通过识别含水印帧来提取受到帧操作攻击的水印信息.首先利用改进的简单线性迭代聚类(simple linear iterative clustering,SLIC)超像素分割算法提取视频帧的固有特征X,这里X是一串7位的0-1序列,是由SLIC超像素分割算法通过预处理、量化等运算得到的聚类中心.将视频帧的固有特征X与汉明码结合形成一个特殊的编码S.以编码S为定位码,利用(7,4)汉明码的纠错机制修改1位可隐藏3位的性能来实现定位码的标识,再基于DCT-SVD(discrete cosine transformation-singular value decomposition)分解将水印信息嵌入到含定位标识的视频中.实验结果表明,该算法不仅能抵抗帧删除、帧添加和重编码等攻击,也能抵抗常见的信号处理操作.
