In the second language acquisition, the study focus of linguistics is the influence of age factors which has always been considered as one of the most controversial issues. Some experts hold that the younger the bette...In the second language acquisition, the study focus of linguistics is the influence of age factors which has always been considered as one of the most controversial issues. Some experts hold that the younger the better and would get good competence to learn language well, meanwhile others believe that adult have more strong motivation and competence.Based on the Brain Plasticity Theory and the Critical Period Hypothesis, and the intention of this thesis is to reveal such a hypothesis that the younger the learner who starts to learn a second language, the greater performance that he will achieve like a native does, through the comparative research between children and adults. The subjects are 100 Chinese learners who begin learning at different levels and ages. According to the results of integrated scores and a collection of the data in the questionnaire, an analysis show that the results acquired would be consistent with the hypothesis.The intention of this research is not only to argue which is better, earlier or later, but also an trial, through investigation and study, to provide some insights and suggestion to the existent issues, especially the children second language education and college English study in China.展开更多
Chimeric plants composed of green and albino tissues have great ornamental value.To unveil the functional genes responsible for albino phenotypes in chimeric plants,we inspected the complete plastid genomes(plastomes)...Chimeric plants composed of green and albino tissues have great ornamental value.To unveil the functional genes responsible for albino phenotypes in chimeric plants,we inspected the complete plastid genomes(plastomes)in green and albino leaf tissues from 23 ornamental chimeric plants belonging to 20 species,including monocots,dicots,and gymnosperms.In nine chimeric plants,plastomes were identical between green and albino tissues.Meanwhile,another 14 chimeric plants were heteroplasmic,showing a mutation between green and albino tissues.We identified 14 different point mutations in eight functional plastid genes related to plastid-encoded RNA polymerase(rpo)or photosystems which caused albinism in the chimeric plants.Among them,12 were deleterious mutations in the target genes,in which early termination appeared due to small deletion-mediated frameshift or single nucleotide substitution.Another was single nucleotide substitution in an intron of the ycf3 and the other was a missense mutation in coding region of the rpoC2 gene.We inspected chlorophyll structure,protein functional model of the rpoC2,and expression levels of the related genes in green and albino tissues of Reynoutria japonica.A single amino acid change,histidine-to-proline substitution,in the rpoC2 protein may destabilize the peripheral helix of plastid-encoded RNA polymerase,impairing the biosynthesis of the photosynthesis system in the albino tissue of R.japonica chimera plant.展开更多
Dear editor,In recent years,endoscopic subureteral transurethral injection(STING)has become the first-line therapy for children with vesicoureteral reflux(VUR)owing its diffusion in clinical practice to a high success...Dear editor,In recent years,endoscopic subureteral transurethral injection(STING)has become the first-line therapy for children with vesicoureteral reflux(VUR)owing its diffusion in clinical practice to a high success rate and minimum complications[1].Macroplastique(Uroplasty,Inc.,Minnetonka,MN,USA)is an efficient and safe bulking agent commonly used in VUR,being non-migratory,non-antigenic,and biocompatible.Moreover,its stability over time,with a virtual no-reabsorption phenomenon,has allowed its application in wider medical fields[2].展开更多
文摘In the second language acquisition, the study focus of linguistics is the influence of age factors which has always been considered as one of the most controversial issues. Some experts hold that the younger the better and would get good competence to learn language well, meanwhile others believe that adult have more strong motivation and competence.Based on the Brain Plasticity Theory and the Critical Period Hypothesis, and the intention of this thesis is to reveal such a hypothesis that the younger the learner who starts to learn a second language, the greater performance that he will achieve like a native does, through the comparative research between children and adults. The subjects are 100 Chinese learners who begin learning at different levels and ages. According to the results of integrated scores and a collection of the data in the questionnaire, an analysis show that the results acquired would be consistent with the hypothesis.The intention of this research is not only to argue which is better, earlier or later, but also an trial, through investigation and study, to provide some insights and suggestion to the existent issues, especially the children second language education and college English study in China.
基金This work was supported by the Bio&Medical Technology Development Program of the NRF,MSIP,Republic of Korea(grant no.NRF-2015M3A9A5030733)grants from the Nuclear R&D Program of the Ministry of Science and ICT(MSIT)and the research program of KAERI,Republic of Korea.
文摘Chimeric plants composed of green and albino tissues have great ornamental value.To unveil the functional genes responsible for albino phenotypes in chimeric plants,we inspected the complete plastid genomes(plastomes)in green and albino leaf tissues from 23 ornamental chimeric plants belonging to 20 species,including monocots,dicots,and gymnosperms.In nine chimeric plants,plastomes were identical between green and albino tissues.Meanwhile,another 14 chimeric plants were heteroplasmic,showing a mutation between green and albino tissues.We identified 14 different point mutations in eight functional plastid genes related to plastid-encoded RNA polymerase(rpo)or photosystems which caused albinism in the chimeric plants.Among them,12 were deleterious mutations in the target genes,in which early termination appeared due to small deletion-mediated frameshift or single nucleotide substitution.Another was single nucleotide substitution in an intron of the ycf3 and the other was a missense mutation in coding region of the rpoC2 gene.We inspected chlorophyll structure,protein functional model of the rpoC2,and expression levels of the related genes in green and albino tissues of Reynoutria japonica.A single amino acid change,histidine-to-proline substitution,in the rpoC2 protein may destabilize the peripheral helix of plastid-encoded RNA polymerase,impairing the biosynthesis of the photosynthesis system in the albino tissue of R.japonica chimera plant.
文摘Dear editor,In recent years,endoscopic subureteral transurethral injection(STING)has become the first-line therapy for children with vesicoureteral reflux(VUR)owing its diffusion in clinical practice to a high success rate and minimum complications[1].Macroplastique(Uroplasty,Inc.,Minnetonka,MN,USA)is an efficient and safe bulking agent commonly used in VUR,being non-migratory,non-antigenic,and biocompatible.Moreover,its stability over time,with a virtual no-reabsorption phenomenon,has allowed its application in wider medical fields[2].
