二语习得的动机变异与微观言语社区的认同和建构

二语习得的动机因人而异,而且是变异中的动机;动机不同,二语习得成效互异。因此,应洞察二语习得动机变异及变异的各种变体,及时发现、界定和定位不同的微观言语社区,把握二语习得动机变异的动向,实现二语习得的可持续发展。

认知社会语言学视域下的汉语四种双及物构式变异研究

本文在认知社会语言学的框架下,基于大规模跨变体语料库,使用机器学习中的随机森林方法,探索了影响汉语四种双及物构式变体选择的句法、语义、语言变体等因素。研究发现,影响双及物构式变异的主要因素是区域变体、长度差异和双及物动词的原型性。其中,区域变体与句法语义因素之间存在明显的交互效应:长度差异对中国内地地区汉语中双及物构式变体选择的影响较小;而在不同区域变体中,动词原型性的影响也有明显差异。这些发现揭示了句法语义因素和语言变体因素如何共同制约了汉语双及物构式变异,并展示了结合机器学习方法和认知社会语言学理论来分析汉语变体变异的优势。

汉语变体中分析型致使构式变异研究——多分类逻辑斯蒂回归建模

以往对于汉语分析型致使构式的研究较少关注其在语言变体维度上的变异。本研究在认知社会语言学的框架下,基于跨变体语料库,使用多分类逻辑斯蒂回归考察了影响致使词“使”、“令”、“让”选择的句法、语义、语言变体等因素。研究发现:1)“令”构式用于关系从句的概率显著高于其他小句类型,其结果谓词倾向于使用形容词,被使者常充当感事。2)相较于“令”,“使”和“让”都更偏好及物动词作为结果谓词、排斥充当感事的被使者。3)当被使者为定指或充当受事时“使”的概率显著提高;而“让”更倾向于充当施事的被使者,当被使者为客体时“让”的概率显著降低。4)“语言变体”与“小句类型”之间存在显著的交互效应:中国大陆地区汉语中“使”和“让”在不同小句类型中的概率差异更大;中国台湾地区汉语和新加坡汉语中“小句类型”对“使”和“让”概率的影响较小,且“让”的概率总是高于“使”;而三个变体在“令”的用法上未表现出显著差异。本文展示了认知社会语言学将语言内部和外部因素整合在同一框架内进行考察的优势,并在更多数据和参项的基础上丰富了汉语分析型致使构式与汉语变体变异的研究。

Physiological and Biochemical Characteristic of a Stripe Mutant with Abnormal Flower Organs in Rice

[Objective] The experiment aimed to explore physiological and biochemical changes of leaves after plants were mutated. [Method] A rice double mutant with stripes on stems, leaves and spikelets were taken as experimental materials to study the enzyme activity changes in different growth stages and amino acid variation in rice. [ Result] The SOD activity in mutant was higher than that in wild plant at tillering metaphase, but lower than that in wild type before heading stage and late flowering; the POD activity in three stages increased firstly then declined and the activity showed highest maximal activity at before heading stage. However, the POD activity in wild type showed the opposite change trend; the CAT activity presented degression at three stages, especially high at tillering metaphase, but reverse changes in wild type; the MDA activity decreased at three stages, but it was still higher than that in wild type, besides, the soluble sugar content of mutant was lower, but total amino acid content was increased. [ Conclusion] The expression of mutant characteristics was correlated with SOD, POD, CAT and MDA activity Changes and these changes made the mutant survive and rice quality change at last.

Improvement of Wild Rice Oryza Longistaminata through Mutation Induction

Influence of a mutation to improve the undesirable traits （shattering, red caryopsis etc.） of wild rice O. longistaminata while preserving its useful genes by radiation 20 Kr gamma rays from 60Co was studied. The mutants issued this irradiation were crossed with the interspecific variety SIK385-b-42-28-28 （O. glaberrima x O. sativa）. Irradiation followed by crossing with interspecific variety generated a large genetic variability, in the subsequent generations, in plant height, maturity, non-shattering grain, kernel colour, spikelets fertility, panicle length, and grain size. This has resulted in identification of promising mutants which possess all the traits of cultivated rice O. sativa （white kernel, non-shattering grain, secondary branchies etc.）. During 2012 rainy season, nineteen selected mutants from M5 and M7 generations were evaluated for yield potential in replicated trials at Longorola station.

Structural Variation Analysis of Mutated Nannochloropsis oceanica Caused by Zeocin Through Genome Re-Sequencing

Zeocin can cause double strand breaks of DNA and thus may be employed as a mutagen. In this study, two strains of Nannochloropsis oceanica, the wild and the Zeocin-tolerant strains, were re-sequenced to verify such function of Zeocin, The results showed that Zeocin can mutate the N. oceanica genome and cause the structural variation. Zeocin either swept away or selected the alleles of genes functioning in ubiquitin-mediated proteolysis, alpha-linolenic acid metabolism, ascorbate and aldarate metabolism, ribosome biogenesis, and circadian rhythm, indicating that N. oceanica may have adjusted its metabolic performances for protein, carbohydrate, and lipid, and changed its ribosome biosynthesis and living rhythm to survive in Zeocin containing medium. In addition, Zeocin caused mutation may have influenced the expression of a set of tanscription factors. It was concluded that Zeocin effectively caused the structural variation of the genome of N. oceanica, and forced the microalgae to select out the alleles of a set of genes around these variations in order to adapt to Zeocin containing medium. Further studies on the genetic basis of the phenotypic adaptation of this haploid and asexual microalga and the application of Zeocin to its genetic improvement are very important.

Novel mutations and sequence variants in exons 3-9 of human T Cell Factor-4 gene in sporadic rectal cancer patients stratified by microsatellite instability

AIM： To establish the role of human T Cell Factor-4 （hTCF-4） gene exons 3-9 mutation status in association with sporadic rectal cancer with microsatellite instability （MSI）. METHODS： Microsatellite markers were genotyped in 93 sporadic rectal cancer patients. Eleven cases were found to be high-frequency MSI （MSI-H）. Sequence analysis of the coding region of the exons 3-9 of hTCF-4 gene was carried out for the 11 MSI-H cases and 10 controls （5 microsatellite stability （MSS） cases and 5 cases with normal mucosa）. The sequencing and MSI identification were used. RESULTS： Several novel mutations and variants were revealed. In exon 4, one is a 4-position continuous alteration which caused amino acid change from Q131T and S132I （391insA, 392 G 〉 A, 393 A 〉 G and 395delC） and another nucleotide deletion （395delC） is present in MSI-H cases （5/10 and 4/10, respectively） but completely absent in the controls.CONCLUSION： Novel mutations in exon 4 of hTCF-4 gene were revealed in this study, which might be of importance in the pathogenesis of sporadic rectal cancer patients with MSI-H.

Characterization of New Allelic Variation for Glutenin in EMS-Mutant Durum Wheat Population （Triticum turgidum L. subsp, durum （Desf.））

The High Molecular Weight HMW-GS and Low-Molecular-Weight LMW-GS Glutenin Subunits are major determinants of wheat dough processing qualities. Tilling populations was generated by EMS mutagenesis from Chaml durum variety. Protein quality was investigated by SDS sedimentation, protein content, gluten content and thousand kernel weights. 21 mutants were selected from 1,500 lines of tilling population depending on the variations of their electrophoresis profiles. The analysis of Glu-B 1 HMW-GS has showed two types of profiles： lines deficient on Bx7 and lines with expression of new protein between （Bx7-ByS） allelic pair combination. The majority of these mutant lines have showed quality compounds associated with bad technological characteristics like the parent Cham l with the exception of two mutant lines expressing new protein that have significantly stronger gluten properties an one mutant deficient on Bx7 HMW-GS that developed high value of SDS. For Glu-B3 LMW-GS coding for LMW glutenin type 1 and 2, new mutant line showing expression of new protein pattern. The mutant showing over-expression of bands on gel SDS-PAGE for LMW typel like Chaml, have produced the highest protein and gluten content, while the new mutant showing new profile have showed high value of Gluten and SDS.

Ontogenetic changes in isotopic signatures of an omnivorous fish Cultrichthys erythropterus in East Lake Taihu,China

The relationship between body size and stable isotopic signatures of the omnivorous Redfin Culter(C ultrichthys erythropterus),commonly found in East Lake Taihu,was investigated. Previous analyses of C. erythropterus stomach contents have shown that this species undergoes a diet switch from being predominantly zooplanktivorous to piscivorous during its life history. This was confirmed by stable carbon isotopic signature(δ 13 C) in this study,in which δ 13 C was positively correlated with both standard length and weight. The importance of littoral-benthic resources in supporting C. erythropterus during its lifespan was also demonstrated using a two-source mixing model,the results of which showed a significant increasing trend in the contribution of littoral-benthic energy. However,the stable nitrogen isotopic signature(δ 15N) exhibited an unusual pattern compared with previous studies. The δ 15 N of C. erythropterus showed no relationship with body size,even though dietary changes were observed. This indicated that δ 15 N alone cannot fully reflect a diet shift in a species and possible variability in isotopic signatures over its life history. This should be considered when using stable isotopic signatures to investigate intra-specific variations and the timing of life-history events,such as estimating the trophic positions of fish species.

Histone Variant H3.3:A versatile H3 variant in health and in disease

Histones are the main protein components of eukaryotic chromatin. Histone variants and histone modifications modulate chromatin structure, ensuring the precise operation of cellular processes associated with genomic DNA. H3.3, an ancient and conserved H3 variant, differs from its canonical H3 counterpart by only five amino acids, yet it plays essential and specific roles in gene transcription, DNA repair and in maintaining genome integrity. Here, we review the most recent insights into the functions of histone H3.3, and the involvement of its mutant forms in human diseases.

Liquid-liquid phase transition in water

Water shows anomalies different from most of other materials.Different sceniaros have been proposed to explain water anomalies,among which the liquid-liquid phase transition(LLPT)is the most discussed one.It attributes water anomalies to the existence of a hypothesized liquid-liquid critical point(LLCP)buried deep in the supercooled region.We briefly review the recent experimental and theoretical progresses on the study of the LLPT in water.These studies include the discussion on the existence of the first order LLPT in supercooled water and the detection of liquid-liquid critical point.Simulational results of different water models for LLPT and the experimental evidence in confined water are also discussed.