10 different species of water mites which are Georgella helvetica, Eylais extendens, Hydrachna globose, Hydrachna prosifera, Hydrachna skorikowi, Hydrodroma despiciens, Hydryphantes dispar, Limnesia fulgida, Eylais se...10 different species of water mites which are Georgella helvetica, Eylais extendens, Hydrachna globose, Hydrachna prosifera, Hydrachna skorikowi, Hydrodroma despiciens, Hydryphantes dispar, Limnesia fulgida, Eylais setosa, Hydryphantes flexuosus were used in this study. The total masses of these species were measured as mg with the use of an elemental analyzer to calculate the percentage of the organic components of their structures. The achieved values were assessed separately for each species and element with the interpolation method. Out of these organic elements, the amount of C with an approximately value of 50% was the highest for all species while the amounts of S which was approximately 1% was determined as the lowest for almost all species. The observed values were discussed in terms of the systematic of water mites.展开更多
The crystal plasticity finite element modeling （CPFEM） is realized in commercial finite element code ABAQUS with UMAT subroutine on the basis of the crystal plasticity theory of rate dependent polycrystal constituti...The crystal plasticity finite element modeling （CPFEM） is realized in commercial finite element code ABAQUS with UMAT subroutine on the basis of the crystal plasticity theory of rate dependent polycrystal constitutive relations in the mesoscopic scale. The initial orientations obtained by electron backscatter diffraction （EBSD） are directly input into the CPFEM to simulate the mechanical response of polycrystalline 1050 pure Al in uniaxial tensile deformation. Two polycrystal models and two tensile strain rates were used in the simulations. The stress-strain curves of tensile deformation were analyzed. The predictions and the corresponding experiment result show reasonable agreement and slight deviation with experiments. The flow true stress of strain rate 0.01 s^-1 is higher than that of strain rate 0.001 s^-1. At the strain less than 0.05, the stress saturated rate of the experiment is higher than the simulated results. However, the stress saturated rate of the experiment becomes gentler than the corresponding simulated predictions at the strain over 0.05. Also, necking was simulated by the two models, but the necking strain is not well predicted. Tensile textures at strain 0.25 were predicted at the low strain rate of 0.001 s^-1. The predictions are in good accord with the experimental results. 2008 University of Science and Technology Beijing. All rights reserved.展开更多
A parallel imaginary EBE (element-by-element )method for solving positive definite linear systems is presented. The EBE strategy is originally used as a sequential method[1.2], and later it is converted to a parallel...A parallel imaginary EBE (element-by-element )method for solving positive definite linear systems is presented. The EBE strategy is originally used as a sequential method[1.2], and later it is converted to a parallelmethod for solving finite element problem in solid mechanics[3]. The main contribution of this paper is to forma general parallel EBE method for the solution of anyPOsitive definite linear system through a so-called imaginary finite element technique. It is then POssible to use.finite elemental without finite element.展开更多
Previous genetic studies in cowpea [Vigna unguiculata (L.) Walp] have shown that an active bipartite transposable element (TE) is responsible for a range of mutant phenotypes of its leaf, stem and flower. Since type I...Previous genetic studies in cowpea [Vigna unguiculata (L.) Walp] have shown that an active bipartite transposable element (TE) is responsible for a range of mutant phenotypes of its leaf, stem and flower. Since type II TEs have not been characterized at the molecular level in cowpea, this study was initiated to survey the presence of type II TEs in the cowpea genome. Type II TEs: Enhancer/Suppressor-mutator (En/Spm) and Miniature Inverted-repeat Transposable Elements (MITEs) were isolated and characterized. The sequence identity between the EnSpm TE clones was 46% at the nucleotide level (NL) and 30% at the amino acid level (AL) while that of MITEs was 71% at NL and 63% at AL. These cowpea En/Spm TEs were 80% homologous with En/Spm elements of other crops at NL and 46% at AL. The MITEs were 96% similar at NL and 18% homologous at AL. DNA gel blot analysis confirmed the presence of the En/Spm TEs in cowpea. RT-PCR (reverse transcriptase polymerase chain reaction) analysis showed that the VuEnSpm-3 and the MITE clone, VuPIF-1 were actively transcribed in wild type and mutant cowpea tissues. Overall, our data show that multiple, divergent lineages of En/Spm and MITEs are present in the cowpea genome, some of which are actively transcribed. Our findings also offer new molecular resource to further investigate the genetic determinants underlying previously described mutant cowpea phenotypes.展开更多
An active miniature inverted-repeat transposable element(MITE),MCL as-A,was previously identified from'Candidatus Liberibacter asiaticus'known to be associated with citrus Huanglongbing(HL B,yellow shoot disea...An active miniature inverted-repeat transposable element(MITE),MCL as-A,was previously identified from'Candidatus Liberibacter asiaticus'known to be associated with citrus Huanglongbing(HL B,yellow shoot disease).To explore the recent transposition status of MCLas-A,389'Ca.L.asiaticus'strains collected from nine regions in China were amplifed using a specific primer set and three representative'Ca.L.asiaticus'strains were analyzed by next-generation sequencing(NGS)approach.PCR and genomic analysis showed that the entire MCLas A was only present in 1.80%(7/389)and the jumping-out type of the MITE was predominant(8123%)in samples tested,suggesting high frequency transposition occurred in'Ca.L.asiaticus'strains recently collected from China.Biological roles of transposition of the active MITE remain to be determined.展开更多
In the present study, we report a survey on a Miniature Inverted Transposable Element （MITE） system known as mPing in 102 varieties of Asian cultivated rice （Oryza sativa L.）. We found that mPing populations could...In the present study, we report a survey on a Miniature Inverted Transposable Element （MITE） system known as mPing in 102 varieties of Asian cultivated rice （Oryza sativa L.）. We found that mPing populations could be generalized Into two families, mPing-1 and mPing-2, according to their sequence structures. Further analysis showed that these two families of mPing had significant bias in their distribution pattern in two subspecies of rice, namely O. sativa ssp. japonica and indica. 0. sativa japonica has a higher proportion of mPing-1 as a general trait, whereas 0. sativa indica has a higher proportion of roPing-2. We also examined the mPing system In a doubled haploid （DH） cross-breeding population of jingxi 17 （japonica） and zhaiyeqing 8 （indica） varieties and observed that the mPing system was not tightly linked to major subspecies-determining genes. Furthermore, we checked the mPing system in 28 accessions of Asian common wild rice O. rufipogon and found the roPing system in 0. rufipogon. The distribution pattern of the roPing system in O. rufipogon indicated a diphyletlc origin of the Asian cultivated rice O. sativa species. We did not find the mPing system in another 20 Oryza species. These results substantiated a previous hypothesis that O. ruflpogon and O. nivara species were the closest relatives of O. sativa and that the two extant subspecies of O. sativa were evolved independently from corresponding ecotypes of O. ruflpogon.展开更多
The Q/q gene, also known as WAP2, is an important gene for wheat domestication and is a member of the AP2 （APETALA2） class of transcription factors. In the present study, we first isolated the WRAP2 allele （where t...The Q/q gene, also known as WAP2, is an important gene for wheat domestication and is a member of the AP2 （APETALA2） class of transcription factors. In the present study, we first isolated the WRAP2 allele （where the superscript ＂t＂ refers to the speciese source, in this case ＂tauschii＂） on chromosome 5D from Aegilops tauschii Coss., the D-genome donor species of common wheat. We found that WRAP2 and the AP2 gene from Arabidopsis share a central core of the AP2 polypeptide, a highly basic 10-amino acid domain, and an AASSGF box, although there are many differences in the 37-amino acid serine-rich acidic domain and the remaining regions. In addition, WRAP2 was highly homologous to the homoeologous loci on 5A and 5B of wheat at both the nucleotide and amino acid level. However, there were some variations that are probably related to gene function. In the first AP2 domain, the amino acids VYL on the 5D and 5A loci were replaced with LLR on 5B. In the 37-amino acid serine-rich acidic domain, WRAP2 on 5D had an extra amino acid insertion. There was also a variation at the 329 amino acid position, which is thought to be related to the appearance of free-threshing wheat. At this position, the amino acid is isoleucine on 5A for the Q allele and valine for the q allele, whereas the amino acid is leucine on 5D and 5B. Furthermore, a Stowaway miniature terminal inverted repeat element （MITE） insertion was present in the ninth intron of WAP2 on 5B of all common wheats and partial tetraploid Triticum turgidum wheats. These results provide new clues for studies into the evolutionary biology of WAP2 and the origin of common wheat.展开更多
MTTEs (Miniature inverted-repeat transposabie elements) are reminiscence ot non-autonomous DNA (class Ⅱ) elements, which are distinguished from other transposable elements by their small size, short terminal inverted...MTTEs (Miniature inverted-repeat transposabie elements) are reminiscence ot non-autonomous DNA (class Ⅱ) elements, which are distinguished from other transposable elements by their small size, short terminal inverted repeats (TIRs), high copy numbers, genie preference, and DNA sequence identity among family members. Although MITEs were first discovered in plants and still actively reshaping genomes, they have been isolated from a wide range of eukaryotic organisms. MITEs can be divided into Tourist-like, Stowaway-like, and pogo-like groups, according to similarities of their TIRs and TSDs (target site duplications). In despite of several models to explain the origin and amplification of MITEs, their mechanisms of transposition and accumulation in eukaryotic genomes remain poorly understood owing to insufficient experimental data. The unique properties of MITEs have been exploited as useful genetic tools for plant genome analysis. Utilization of MITEs as effective and informative genomic markers and potential application of MITEs in plants systematic, phylogenetic, and genetic studies are discussed.展开更多
文摘10 different species of water mites which are Georgella helvetica, Eylais extendens, Hydrachna globose, Hydrachna prosifera, Hydrachna skorikowi, Hydrodroma despiciens, Hydryphantes dispar, Limnesia fulgida, Eylais setosa, Hydryphantes flexuosus were used in this study. The total masses of these species were measured as mg with the use of an elemental analyzer to calculate the percentage of the organic components of their structures. The achieved values were assessed separately for each species and element with the interpolation method. Out of these organic elements, the amount of C with an approximately value of 50% was the highest for all species while the amounts of S which was approximately 1% was determined as the lowest for almost all species. The observed values were discussed in terms of the systematic of water mites.
基金the International Linkage Project of Australian Research Council(No.DP0451197).
文摘The crystal plasticity finite element modeling （CPFEM） is realized in commercial finite element code ABAQUS with UMAT subroutine on the basis of the crystal plasticity theory of rate dependent polycrystal constitutive relations in the mesoscopic scale. The initial orientations obtained by electron backscatter diffraction （EBSD） are directly input into the CPFEM to simulate the mechanical response of polycrystalline 1050 pure Al in uniaxial tensile deformation. Two polycrystal models and two tensile strain rates were used in the simulations. The stress-strain curves of tensile deformation were analyzed. The predictions and the corresponding experiment result show reasonable agreement and slight deviation with experiments. The flow true stress of strain rate 0.01 s^-1 is higher than that of strain rate 0.001 s^-1. At the strain less than 0.05, the stress saturated rate of the experiment is higher than the simulated results. However, the stress saturated rate of the experiment becomes gentler than the corresponding simulated predictions at the strain over 0.05. Also, necking was simulated by the two models, but the necking strain is not well predicted. Tensile textures at strain 0.25 were predicted at the low strain rate of 0.001 s^-1. The predictions are in good accord with the experimental results. 2008 University of Science and Technology Beijing. All rights reserved.
文摘A parallel imaginary EBE (element-by-element )method for solving positive definite linear systems is presented. The EBE strategy is originally used as a sequential method[1.2], and later it is converted to a parallelmethod for solving finite element problem in solid mechanics[3]. The main contribution of this paper is to forma general parallel EBE method for the solution of anyPOsitive definite linear system through a so-called imaginary finite element technique. It is then POssible to use.finite elemental without finite element.
文摘Previous genetic studies in cowpea [Vigna unguiculata (L.) Walp] have shown that an active bipartite transposable element (TE) is responsible for a range of mutant phenotypes of its leaf, stem and flower. Since type II TEs have not been characterized at the molecular level in cowpea, this study was initiated to survey the presence of type II TEs in the cowpea genome. Type II TEs: Enhancer/Suppressor-mutator (En/Spm) and Miniature Inverted-repeat Transposable Elements (MITEs) were isolated and characterized. The sequence identity between the EnSpm TE clones was 46% at the nucleotide level (NL) and 30% at the amino acid level (AL) while that of MITEs was 71% at NL and 63% at AL. These cowpea En/Spm TEs were 80% homologous with En/Spm elements of other crops at NL and 46% at AL. The MITEs were 96% similar at NL and 18% homologous at AL. DNA gel blot analysis confirmed the presence of the En/Spm TEs in cowpea. RT-PCR (reverse transcriptase polymerase chain reaction) analysis showed that the VuEnSpm-3 and the MITE clone, VuPIF-1 were actively transcribed in wild type and mutant cowpea tissues. Overall, our data show that multiple, divergent lineages of En/Spm and MITEs are present in the cowpea genome, some of which are actively transcribed. Our findings also offer new molecular resource to further investigate the genetic determinants underlying previously described mutant cowpea phenotypes.
基金Funded by the National Natural Science Foundation of China(31671992,31871925)the National Key R&D Program of China(2018YFD0201500)the Key R&D Program of Guangxi,China(Gui Ke AA18118046).
文摘An active miniature inverted-repeat transposable element(MITE),MCL as-A,was previously identified from'Candidatus Liberibacter asiaticus'known to be associated with citrus Huanglongbing(HL B,yellow shoot disease).To explore the recent transposition status of MCLas-A,389'Ca.L.asiaticus'strains collected from nine regions in China were amplifed using a specific primer set and three representative'Ca.L.asiaticus'strains were analyzed by next-generation sequencing(NGS)approach.PCR and genomic analysis showed that the entire MCLas A was only present in 1.80%(7/389)and the jumping-out type of the MITE was predominant(8123%)in samples tested,suggesting high frequency transposition occurred in'Ca.L.asiaticus'strains recently collected from China.Biological roles of transposition of the active MITE remain to be determined.
基金Supported by Grants from the Ministry of Science and Technology of China （2002AA2Z1003 and 2003AA222091 ）, Shanghai Municipal Commission of Science and Technology （038019315）, and the National Natural Science Foundation of China （30325014）.
文摘In the present study, we report a survey on a Miniature Inverted Transposable Element （MITE） system known as mPing in 102 varieties of Asian cultivated rice （Oryza sativa L.）. We found that mPing populations could be generalized Into two families, mPing-1 and mPing-2, according to their sequence structures. Further analysis showed that these two families of mPing had significant bias in their distribution pattern in two subspecies of rice, namely O. sativa ssp. japonica and indica. 0. sativa japonica has a higher proportion of mPing-1 as a general trait, whereas 0. sativa indica has a higher proportion of roPing-2. We also examined the mPing system In a doubled haploid （DH） cross-breeding population of jingxi 17 （japonica） and zhaiyeqing 8 （indica） varieties and observed that the mPing system was not tightly linked to major subspecies-determining genes. Furthermore, we checked the mPing system in 28 accessions of Asian common wild rice O. rufipogon and found the roPing system in 0. rufipogon. The distribution pattern of the roPing system in O. rufipogon indicated a diphyletlc origin of the Asian cultivated rice O. sativa species. We did not find the mPing system in another 20 Oryza species. These results substantiated a previous hypothesis that O. ruflpogon and O. nivara species were the closest relatives of O. sativa and that the two extant subspecies of O. sativa were evolved independently from corresponding ecotypes of O. ruflpogon.
基金supported by the National BasicResearch Program(973 Program2009CB 118300),"100-Talent Program"of The Chinese Academy of Sciences,and by the Education Bureau and Science and Technology Bureau of Sichuan Province.
文摘The Q/q gene, also known as WAP2, is an important gene for wheat domestication and is a member of the AP2 （APETALA2） class of transcription factors. In the present study, we first isolated the WRAP2 allele （where the superscript ＂t＂ refers to the speciese source, in this case ＂tauschii＂） on chromosome 5D from Aegilops tauschii Coss., the D-genome donor species of common wheat. We found that WRAP2 and the AP2 gene from Arabidopsis share a central core of the AP2 polypeptide, a highly basic 10-amino acid domain, and an AASSGF box, although there are many differences in the 37-amino acid serine-rich acidic domain and the remaining regions. In addition, WRAP2 was highly homologous to the homoeologous loci on 5A and 5B of wheat at both the nucleotide and amino acid level. However, there were some variations that are probably related to gene function. In the first AP2 domain, the amino acids VYL on the 5D and 5A loci were replaced with LLR on 5B. In the 37-amino acid serine-rich acidic domain, WRAP2 on 5D had an extra amino acid insertion. There was also a variation at the 329 amino acid position, which is thought to be related to the appearance of free-threshing wheat. At this position, the amino acid is isoleucine on 5A for the Q allele and valine for the q allele, whereas the amino acid is leucine on 5D and 5B. Furthermore, a Stowaway miniature terminal inverted repeat element （MITE） insertion was present in the ninth intron of WAP2 on 5B of all common wheats and partial tetraploid Triticum turgidum wheats. These results provide new clues for studies into the evolutionary biology of WAP2 and the origin of common wheat.
文摘MTTEs (Miniature inverted-repeat transposabie elements) are reminiscence ot non-autonomous DNA (class Ⅱ) elements, which are distinguished from other transposable elements by their small size, short terminal inverted repeats (TIRs), high copy numbers, genie preference, and DNA sequence identity among family members. Although MITEs were first discovered in plants and still actively reshaping genomes, they have been isolated from a wide range of eukaryotic organisms. MITEs can be divided into Tourist-like, Stowaway-like, and pogo-like groups, according to similarities of their TIRs and TSDs (target site duplications). In despite of several models to explain the origin and amplification of MITEs, their mechanisms of transposition and accumulation in eukaryotic genomes remain poorly understood owing to insufficient experimental data. The unique properties of MITEs have been exploited as useful genetic tools for plant genome analysis. Utilization of MITEs as effective and informative genomic markers and potential application of MITEs in plants systematic, phylogenetic, and genetic studies are discussed.
