http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Ziolkowski, Piotr A.,Underwood, Charles J.,Lambing, Christophe,Martinez-Garcia, Marina,Lawrence, Emma J.,Ziolkowska, Liliana,Griffin, Catherine,Choi, Kyuha,Franklin, F. Chris H.,Martienssen, Robert A. Cold Spring Harbor Laboratory Press 2017 Genes & development Vol.31 No.3
<P>Here, Ziolkowski et al. combine high-throughput fluorescence methods to measure crossovers with natural <I>Arabidopsis</I> ecotypes in order to identify the first <I>trans</I>-acting modifier of meiotic recombination in plants. The authors found that HEI10, which encodes a conserved ubiquitin E3 ligase, naturally limits <I>Arabidopsis</I> crossovers and has the potential to influence the response to selection.</P><P>During meiosis, homologous chromosomes undergo crossover recombination, which creates genetic diversity and balances homolog segregation. Despite these critical functions, crossover frequency varies extensively within and between species. Although natural crossover recombination modifier loci have been detected in plants, causal genes have remained elusive. Using natural <I>Arabidopsis thaliana</I> accessions, we identified two major recombination quantitative trait loci (<I>rQTL</I>s) that explain 56.9% of crossover variation in Col×Ler F<SUB>2</SUB> populations. We mapped <I>rQTL1</I> to semidominant polymorphisms in <I>HEI10</I>, which encodes a conserved ubiquitin E3 ligase that regulates crossovers. Null <I>hei10</I> mutants are haploinsufficient, and, using genome-wide mapping and immunocytology, we show that transformation of additional <I>HEI10</I> copies is sufficient to more than double euchromatic crossovers. However, heterochromatic centromeres remained recombination-suppressed. The strongest <I>HEI10</I>-mediated crossover increases occur in subtelomeric euchromatin, which is reminiscent of sex differences in <I>Arabidopsis</I> recombination. Our work reveals that HEI10 naturally limits <I>Arabidopsis</I> crossovers and has the potential to influence the response to selection.</P>
Three-Dimensional Microstructural Modelling of Wear, Crack Initiation and Growth in Rail Steel
Fletcher, D.I.,Franklin, F.J.,Garnham, J.E.,Muyupa, E.,Papaelias, M.,Davis, C.L.,Kapoor, A.,Widiyarta, M.,Vasic, G. The Korean Society for Railway 2008 International Journal of Railway Vol.1 No.3
Rolling-sliding, cyclic contact of wheel and rail progressively alters the microstructure of the contacting steels, eventually leading to micro-scale crack initiation, wear and macro-scale crack growth in the railhead. Relating the microstructural changes to subsequent wear and cracking is being accomplished through modelling at three spatial scales: (i) bulk material (ii) multi-grain and (iii) sub-grain. The models incorporate detailed information from metallurgical examinations of used rails and tested rail material. The initial 2-dimensional models representing the rail material are being further developed into 3-dimensional models. Modelling is taking account of thermal effects, and traffic patterns to which the rails are exposed.
Three-Dimensional Microstructural Modelling Of Wear, Crack Initiation and Growth In Rail Steel
D.I. Fletcher,F.J. Franklin,J.E. Garnham,E. Muyupa,M. Papaelias,C.L. Davis,A. Kapoor,M. Widiyarta,G. Vasie 한국철도학회 2008 International Journal of Railway Vol.1 No.3
Rolling-sliding, cyclic contact of wheel and rail progressively alters the microstructure of the contacting steels, eventually leading to micro-scale crack initiation, wear and macro-scale crack growth in the railhead. Relating the microstructural changes to subsequent wear and cracking is being accomplished through modelling at three spatial scales: (ⅰ) bulk material (ⅱ) multi-grain and (ⅲ) sub-grain. The models incorporate detailed information from metallurgical examinations of used rails and tested rail material. The initial 2-dimensional models representing the rail material are being further developed into 3-dimensional models. Modelling is taking account of thermal effects, and traffic patterns to which the rails are exposed.