The Experts below are selected from a list of 93222 Experts worldwide ranked by ideXlab platform
Klaus Bartholome - One of the best experts on this subject based on the ideXlab platform.
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recessively inherited l dopa responsive dystonia caused by a Point Mutation q381k in the tyrosine hydroxylase gene
Human Molecular Genetics, 1995Co-Authors: Per M Knappskog, Barbara Ludecke, Torgeir Flatmark, J Mallet, Klaus BartholomeAbstract:Tyrosine hydroxylase (TH) catalyzes the conversion of L-tyrosine to L-dihydroxyphenylalanine (L-DOPA), the rate-limiting step in the biosynthesis of dopamine. Recently, we described a Point Mutation in hTH (Q381K) in a family of two siblings suffering from progressive L-DOPA-responsive dystonia (DRD), representing the first reported Mutation in this gene. We here describe the cloning, expression and steady-state kinetic properties of the recombinant mutant enzyme. When expressed by a coupled in vitro transcription-translation system and in E. coli, the mutant enzyme represents a kinetic variant form, with a reduced affinity for L-tyrosine. The 'residual activity' of about 15% of the corresponding wild-type hTH (isoform hTH1), at substrate concentrations prevailing in vivo, is compatible with the clinical phenotype of the two Q381K homozygote patients carrying this recessively inherited Mutation.
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a Point Mutation in the tyrosine hydroxylase gene associated with segawa s syndrome
Human Genetics, 1995Co-Authors: Barbara Ludecke, Bernd Dworniczak, Klaus BartholomeAbstract:We have examined the molecular basis of Segawa's syndrome in six families with seven affected children. In one family two siblings with this disease carried a Point Mutation in exon 11 of the tyrosine hydroxylase gene, resulting in an amino acid exchange of Gln381 to Lys381. These results suggest that a change in tyrosine hydroxylase causes this form of Segawa's syndrome.
Huanwen Tang - One of the best experts on this subject based on the ideXlab platform.
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a single Point Mutation evolutionary programming
Information Processing Letters, 2004Co-Authors: Mingjun Ji, Huanwen TangAbstract:In this paper, we propose an improved evolutionary programming based on single-Point Mutation, which is named Single-Point Mutation Evolutionary Programming (SPMEP). The distinctions between SPMEP and the classical evolutionary programming (EP) are the single-Point Mutation for each solution in each iteration and the fixed Mutation scheme for deviation η. Simulation results show that SPMEP is obviously superior to the classical EP, fast EP and generalized EP for multimodal and high-dimensional functions.
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a single Point Mutation evolutionary programming
Information Processing Letters, 2004Co-Authors: Mingjun Ji, Huanwen TangAbstract:In this paper, we propose an improved evolutionary programming based on single-Point Mutation, which is named Single-Point Mutation Evolutionary Programming (SPMEP). The distinctions between SPMEP and the classical evolutionary programming (EP) are the single-Point Mutation for each solution in each iteration and the fixed Mutation scheme for deviation η. Simulation results show that SPMEP is obviously superior to the classical EP, fast EP and generalized EP for multimodal and high-dimensional functions.
Agnar Helgason - One of the best experts on this subject based on the ideXlab platform.
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the y chromosome Point Mutation rate in humans
Nature Genetics, 2015Co-Authors: Axel W Einarsson, Valdis B Guðmundsdottir, Asgeir Sigurðsson, Ellen Gunnarsdottir, Anuradha Jagadeesan, Agnar Helgason, Sunna S EbenesersdottirAbstract:Agnar Helgason and colleagues report the Point Mutation rate for the male-specific euchromatic sequence of the Y chromosome based on 753 Icelandic males. They find that the non-recombining portions of the Y chromosome mutate at a faster rate than palindromic regions, suggesting that gene conversion acts to correct Mutations in palindromic sequences.
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the y chromosome Point Mutation rate in humans
Nature Genetics, 2015Co-Authors: Agnar Helgason, Axel W Einarsson, Valdis B Guðmundsdottir, Asgeir Sigurðsson, Ellen Gunnarsdottir, Anuradha Jagadeesan, Sunna S Ebenesersdottir, Augustine Kong, Kari StefanssonAbstract:Mutations are the fundamental source of biological variation, and their rate is a crucial parameter for evolutionary and medical studies. Here we used whole-genome sequence data from 753 Icelandic males, grouped into 274 patrilines, to estimate the Point Mutation rate for 21.3 Mb of male-specific Y chromosome (MSY) sequence, on the basis of 1,365 meioses (47,123 years). The combined Mutation rate for 15.2 Mb of X-degenerate (XDG), X-transposed (XTR) and ampliconic excluding palindromes (rAMP) sequence was 8.71 × 10(-10) Mutations per position per year (PPPY). We observed a lower rate (P = 0.04) of 7.37 × 10(-10) PPPY for 6.1 Mb of sequence from palindromes (PAL), which was not statistically different from the rate of 7.2 × 10(-10) PPPY for paternally transmitted autosomes. We postulate that the difference between PAL and the other MSY regions may provide an indication of the rate at which nascent autosomal and PAL de novo Mutations are repaired as a result of gene conversion.
W B Langdon - One of the best experts on this subject based on the ideXlab platform.
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smooth uniform crossover with smooth Point Mutation in genetic programming a preliminary study
European Conference on Genetic Programming, 1999Co-Authors: J Page, Riccardo Poli, W B LangdonAbstract:In this paper we examine the behaviour of the uniform crossover and Point Mutation GP operators [12] on the even-n-parity problem for n = 3,4,6 and present a novel representation of function nodes, designed to allow the search operators to make smaller movements around the solution space. Using this representation, performance on the even-6-parity problem is improved by three orders of magnitude relative to the estimate given for standard GP in [5].
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schema theory for genetic programming with one Point crossover and Point Mutation
Evolutionary Computation, 1998Co-Authors: Riccardo Poli, W B LangdonAbstract:We review the main results obtained in the theory of schemata in genetic programming (GP), emphasizing their strengths and weaknesses. Then we propose a new, simpler definition of the concept of schema for GP, which is closer to the original concept of schema in genetic algorithms (GAs). Along with a new form of crossover, one-Point crossover, and Point Mutation, this concept of schema has been used to derive an improved schema theorem for GP that describes the propagation of schemata from one generation to the next. We discuss this result and show that our schema theorem is the natural counterpart for GP of the schema theorem for GAs, to which it asymptotically converges.
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a new schema theory for genetic programming with one Point crossover and Point Mutation
: The University of Birmingham B15 2TT UK., 1997Co-Authors: Riccardo Poli, W B LangdonAbstract:In this paper we first review the main results obtained in the theory of schemata in Genetic Programming (GP) emphasising their strengths and weaknesses. Then we propose a new, simpler definition of the concept of schema for GP which is quite close to the original concept of schema in genetic algorithms (GAs). Along with a new form of crossover, one-Point crossover, and Point Mutation this concept of schema has been used to derive an improved schema theorem for GP which describes the propagation of schemata from one generation to the next. In the paper we discuss this result and show that our schema theorem is the natural counterpart for GP of the schema theorem for GAs, to which it asymptotically converges.
Barbara Ludecke - One of the best experts on this subject based on the ideXlab platform.
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recessively inherited l dopa responsive dystonia caused by a Point Mutation q381k in the tyrosine hydroxylase gene
Human Molecular Genetics, 1995Co-Authors: Per M Knappskog, Barbara Ludecke, Torgeir Flatmark, J Mallet, Klaus BartholomeAbstract:Tyrosine hydroxylase (TH) catalyzes the conversion of L-tyrosine to L-dihydroxyphenylalanine (L-DOPA), the rate-limiting step in the biosynthesis of dopamine. Recently, we described a Point Mutation in hTH (Q381K) in a family of two siblings suffering from progressive L-DOPA-responsive dystonia (DRD), representing the first reported Mutation in this gene. We here describe the cloning, expression and steady-state kinetic properties of the recombinant mutant enzyme. When expressed by a coupled in vitro transcription-translation system and in E. coli, the mutant enzyme represents a kinetic variant form, with a reduced affinity for L-tyrosine. The 'residual activity' of about 15% of the corresponding wild-type hTH (isoform hTH1), at substrate concentrations prevailing in vivo, is compatible with the clinical phenotype of the two Q381K homozygote patients carrying this recessively inherited Mutation.
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a Point Mutation in the tyrosine hydroxylase gene associated with segawa s syndrome
Human Genetics, 1995Co-Authors: Barbara Ludecke, Bernd Dworniczak, Klaus BartholomeAbstract:We have examined the molecular basis of Segawa's syndrome in six families with seven affected children. In one family two siblings with this disease carried a Point Mutation in exon 11 of the tyrosine hydroxylase gene, resulting in an amino acid exchange of Gln381 to Lys381. These results suggest that a change in tyrosine hydroxylase causes this form of Segawa's syndrome.
