Word learning and the cerebral hemispheres: from serial to parallel processing of written words

Reading familiar words differs from reading unfamiliar non-words in two ways. First, word reading is faster and more accurate than reading of unfamiliar non-words. Second, effects of letter length are reduced for words, particularly when they are presented in the right visual field in familiar formats. Two experiments are reported in which right-handed participants read aloud non-words presented briefly in their left and right visual fields before and after training on those items. The non-words were interleaved with familiar words in the naming tests. Before training, naming was slow and error prone, with marked effects of length in both visual fields. After training, fewer errors were made, naming was faster, and the effect of length was much reduced in the right visual field compared with the left. We propose that word learning creates orthographic word forms in the mid-fusiform gyrus of the left cerebral hemisphere. Those word forms allow words to access their phonological and semantic representations on a lexical basis. But orthographic word forms also interact with more posterior letter recognition systems in the middle/inferior occipital gyri, inducing more parallel processing of right visual field words than is possible for any left visual field stimulus, or for unfamiliar non-words presented in the right visual field.     

A genome-wide association study identifies a new variant associated with word reading fluency in Chinese children

Reading disability exhibited defects in different cognitive domains, including word reading fluency, word reading accuracy, phonological awareness, rapid automatized naming and morphological awareness. To identify the genetic basis of Chinese reading disability, we conducted a genome-wide association study (GWAS) of the cognitive traits related to Chinese reading disability in 2284 unrelated Chinese children. Among the traits analyzed in the present GWAS, we detected one genome-wide significant association (p < 5 × 10⁻⁸) on word reading fluency for one SNP on 4p16.2, within EVC genes (rs6446395, p = 7.33 × 10⁻¹⁰). Rs6446395 also showed significant association with Chinese character reading accuracy (p = 2.95 × 10⁻⁴), phonological awareness (p = 7.11 × 10⁻³) and rapid automatized naming (p = 4.71 × 10⁻³), implying multiple effects of this variant. The eQTL data showed that rs6446395 affected EVC expression in the cerebellum. Gene-based analyses identified a gene (PRDM10) to be associated with word reading fluency at the genome-wide level. Our study discovered a new candidate susceptibility variant for reading ability and provided new insights into the genetics of developmental dyslexia in Chinese children.     

单个汉字阅读过程中的双线路机制

因为汉字具有与拼音字母语言不同的方形书写结构以及字型映射规则,已有很多研究关注这两种语言是否存在着不同的阅读机制,但还在争论中.本研究通过功能磁共振技术,采用汉字和英文两种语言的真字(词),假字(词)以及非字(词)作为刺激材料来进一步研究此问题.研究结果显示:在高频字(词)条件下,汉字和英文具有相似的阅读机制,但在阅读假字(词)时,它们的阅读机制差异很大.具体表现为英文假词激活了左脑缘上回,而汉字假词激活了左脑额中回.研究结果说明:1)汉英双语者可能采用了两种不同的双线路机制来读取汉字和英文单词.2)汉英双语者在阅读英文假词时,须借助缘上回脑区进行字型转换.而在阅读汉字假字时,则需通过额中回进行笔画分析.     

Endoperoxide polyketides from a Chinese Plakortis simplex: Further evidence of the impact of stereochemistry on antimalarial activity of simple 1,2-dioxanes

Chemical investigation of the organic extract obtained from the sponge Plakortis simplex collected in the South China Sea afforded five new polyketide endoperoxides (2 and 4–7), along with two known analogues (1 and 3). The stereostructures of these metabolites have been deduced on the basis of spectroscopic analysis and chemical conversion. The isolated endoperoxide derivatives have been tested for their in vitro antimalarial activity against Plasmodium falciparum strains, showing IC₅₀ values in the low micromolar range. The structure–activity relationships were analyzed by means of a detailed computational investigation and rationalized in the light of the mechanism of action proposed for this class of simple antimalarials. The relative orientation of the atoms involved in the putative radical generation and transfer reaction was demonstrated to have a great impact on the antimalarial activity. The resulting 3D pharmacophoric model can be a useful guide to design simple and effective antimalarial lead compounds belonging to the class of 1,2-dioxanes.     

DNA is present in the nucleomorph of cryptomonads: Further evidence that the chloroplast evolved from a eukaryotic endosymbiont

Summary The nucleomorph is a unique self-replicating organelle which is invariably present in the periplastidal compartment of cryptomonads. The nucleomorph ofCryptomonas abbreviata is located in a groove on the inner face of the pyrenoid. When JB-4-embedded sections ofC. abbreviata are stained with 4-6-diamidino-2-phenylindole (DAPI), the nucleomorph exhibits a blue fluorescence characteristic of DNA-DAPI complexes. This fluorescence is removed by DNase digestion, but not by RNase. When cells are prepared for electron microscopy by the method of Ryter and Kellenberger (Schreil 1964), a network of fine DNA-like fibrils is observed in the nucleomorph matrix. It is estimated that the nucleomorph contains between 10⁸ and 10⁹ daltons of DNA. The presence of DNA in nucleomorphs strongly supports the hypothesis that the nucleomorph is the vestigial nucleus of a eukaryotic endosymbiont. It is postulated that this eukaryotic symbiont was an ancestral red alga or an organism closely related to red algae. The cryptomonad host cell, on the other hand, is not evolutionarily close to any other group of algae.     

Association between polymorphisms in the promoter region of miR‐17‐92 cluster and systemic lupus erythematosus in a Chinese population

The aim of this study was to investigate the association of genetic polymorphisms in the promoter region of miR‐17‐92 with systemic lupus erythematosus (SLE). The gene polymorphism was analysed using SNaPshot in 312 SLE patients and 396 controls. Relative expression of miR‐17‐92 was measured by quantitative real‐time PCR. Association was found between rs9515692 and a decreased risk of SLE (CT vs CC: OR = 0.65, 95%CI, 0.46‐0.92, P = .014; CT+TT vs CC: OR = 0.64, 95%CI, 0.46‐0.90, P = .009; T vs C: OR = 0.69, 95%CI, 0.52‐0.92, P = .010, respectively). Haplotype analysis showed that C‐G‐G, C‐A‐A haplotypes were associated with an increased SLE risk (OR=4.46, 95%CI, 2.17‐9.17, P < 0.001; OR=2.33, 95%CI, 1.44‐3.76, P < 0.001, respectively). T allele and CT+TT genotypes in rs9515692 were associated with decreased risk of anti‐dsDNA in SLE (CT+TT vs CC: OR = 0.42, 95%CI = 0.24‐0.72, P = .002; T vs A: OR = 0.49, 95%CI = 0.31‐0.79, P = .003). Moreover, rs9515692 CT+TT genotypes had a higher level of miR‐17 as compared to CC genotype (P = .017). These findings suggest that the rs9515692 CT+TT genotypes were a protective factor for the susceptibility of SLE, probably by increasing the expression of miR‐17.     

LncRNA AWPPH as a prognostic predictor in human cancers in Chinese population: evidence from meta-analysis

Background: Long non-coding RNA associated with poor prognosis of hepatocellular carcinoma (AWPPH) is dysregulated in a variety of human cancers. However, the prognostic value of AWPPH in various cancers remains unclear.Methods: Comprehensive literature search was performed in PubMed, Web of Science, CNKI and Wangfang databases, and eligible studies were obtained according to the inclusion and exclusion criteria. The pooled hazard ratios (HRs) and odds ratios (ORs) were applied to assess the clinical value of AWPPH expression for overall survival (OS) and clinicopathological features.Results: A total of 19 articles including 1699 cancer patients were included in the study. The pooled results demonstrated that evaluated AWPPH expression was positively related to a poorer overall survival of patients with cancers (HR = 1.79, 95%CI: 1.44–2.14, P<0.001). Subgroup analysis revealed that tumor type and sample size affect the predictive value of AWPPH on OS, whereas cut-off value and HR estimation method have no impact on it. In addition, the pooled data also showed that AWPPH was positively linked to advanced TNM stage (OR = 2.50, 95%CI: 1.94–3.22, P<0.001), bigger tumor size (OR = 2.64, 95%CI: 1.47–4.73, P=0.001), macro-vascular invasion (OR = 2.08, 95%CI: 1.04–4.16, P=0.04) and lymph node metastasis (OR = 2.68, 95%CI: 1.82–3.96, P<0.001). Moreover, the results of the trim and fill analysis confirmed the reliability of our finding.Conclusions: Up-regulation of AWPPH was associated with advanced TNM stage, bigger tumor size, worse lymph node metastasis, macro-vascular invasion and shorter overall survival, suggesting that AWPPH may serve as a biomarker for prognosis and clinicopathological characteristics in human cancers among the Chinese population.     

Genetic risk factors for nonsyndromic cleft lip with or without cleft palate in a Mesoamerican population: Evidence for IRF6 and variants at 8q24 and 10q25

INTRODUCTION: Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is one of the most common of all birth defects. NSCL/P has a multifactorial etiology that includes both genetic and environmental factors. The IRF6 gene and three further susceptibility loci at 8q24, 10q25, and 17q22, which were identified by a recent genome‐wide association scan (GWAS), are confirmed genetic risk factors for NSCL/P in patients of European descent. METHODS: A case‐control association study was performed to investigate whether these four risk loci contribute to NSCL/P in a Mesoamerican population using four single nucleotide polymorphisms to represent IRF6 and the three novel susceptibility loci. A total of 149 NSCL/P patients and 303 controls of Mayan origin were included. RESULTS: Single marker analysis revealed a significant association between NSCL/P and risk variants in IRF6 and the 8q24 and 10q25 loci. In contrast to previous findings, the association at the 8q24 locus was driven solely by homozygote carriers of the risk allele. This suggests that this locus might act in a recessive manner in the Mayan population. No evidence for association was found at the 17q22 locus. This may have been attributable to the limited power of the sample. CONCLUSION: These results suggest that IRF6 and the 10q25 and 8q24 loci confer a risk for the development of NSCL/P in persons of Mayan origin. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.     

Functional analysis of four Class III peroxidases from Chinese pear fruit: a critical role in lignin polymerization

Pear fruit could be used as good medicine to relieve coughs, promote salivation, nourish lungs, and reduce the risk of many diseases for its phytochemical action. Lignin is a major secondary metabolite in Chinese pear fruit. Class III peroxidase (Class III PRX) is an important enzyme in the biosynthesis of lignin in plants. However, we poorly understand the role of PRXs in lignin biosynthesis in Chinese pear fruit. In our study, we cloned five PRXs from Chinese pear (Pyrus bretschneideri), namely PbPRX2, PbPRX22, PbPRX34, PbPRX64, and PbPRX75, which contained 978 bp encoded 326 amino acids (AA), 2607 bp encoded 869 AA, 972 bp encoded 324 AA, 687 bp encoded 229 AA, and 1020 bp encoded 340 AA, respectively. Enzyme activity analysis showed that four recombinant PbPRX proteins had catalytic activities for pyrogallol, guaiacol, ferulic acid, coniferyl alcohol, and sinapyl alcohol. Subcellular localization experiments showed that these genes were located in the cell wall or cell membrane. Enzyme activity and kinetics of PbPRX2 revealed its role in polymerization of lignin in Chinese pear fruit. The present study suggested that PbPRXs played critical roles in lignin biosynthesis in Chinese pear fruit.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-021-00949-9.     

中国大陆溪颏蜉属Rhithrogena分类研究及一新种描述(蜉蝣目:扁蜉科)

本文对我国大陆地区溪颏蜉属Rhithrogena作了初步的分类研究。其中,报道1新种(黄溪颏蜉Rhithrogena lutea,sp．nov．)、2个中国新记录种(贝氏溪颏蜉R．bajkovae Sowa和赖氏溪颏蜉R．lepnevae Brodsky),并对其它3种[武夷溪颏蜉R.wuyinensis(Gui et al．),comb．nov．、三刺溪颏蜉R．trispina Zhou et Zheng和东方溪颏蜉R．orientalis You(=三港溪颏蜉R．sangangensis You,新异名)]作了订正,并给出了我国己知7种的成虫检索表。新种——黄溪颏蜉R．lutea,sp．nov．,(仅知成虫,图14))标本采自四川省九寨沟县双河镇附近河旁(正模♂,副模4♂♂10♀♀,2000-VIII-11,采集人为谢强和周长发),区别于该属其它己知种的最明显特征就是阳茎无阳端突、生殖孔的边缘具2枚齿突。标本保存在南京师范大学生命科学学院。     

Hydrological regulation drives regime shifts: evidence from paleolimnology and ecosystem modeling of a large shallow Chinese lake

Quantitative evidence of sudden shifts in ecological structure and function in large shallow lakes is rare, even though they provide essential benefits to society. Such ‘regime shifts’ can be driven by human activities which degrade ecological stability including water level control (WLC) and nutrient loading. Interactions between WLC and nutrient loading on the long‐term dynamics of shallow lake ecosystems are, however, often overlooked and largely underestimated, which has hampered the effectiveness of lake management. Here, we focus on a large shallow lake (Lake Chaohu) located in one of the most densely populated areas in China, the lower Yangtze River floodplain, which has undergone both WLC and increasing nutrient loading over the last several decades. We applied a novel methodology that combines consistent evidence from both paleolimnological records and ecosystem modeling to overcome the hurdle of data insufficiency and to unravel the drivers and underlying mechanisms in ecosystem dynamics. We identified the occurrence of two regime shifts: one in 1963, characterized by the abrupt disappearance of submerged vegetation, and another around 1980, with strong algal blooms being observed thereafter. Using model scenarios, we further disentangled the roles of WLC and nutrient loading, showing that the 1963 shift was predominantly triggered by WLC, whereas the shift ca. 1980 was attributed to aggravated nutrient loading. Our analysis also shows interactions between these two stressors. Compared to the dynamics driven by nutrient loading alone, WLC reduced the critical P loading and resulted in earlier disappearance of submerged vegetation and emergence of algal blooms by approximately 26 and 10 years, respectively. Overall, our study reveals the significant role of hydrological regulation in driving shallow lake ecosystem dynamics, and it highlights the urgency of using multi‐objective management criteria that includes ecological sustainability perspectives when implementing hydrological regulation for aquatic ecosystems around the globe.     

我国大陆细蜉属Caenis 修订及一新种描述(蜉蝣目:细蜉科)

我国大陆细蜉属Caenis共知5种,其中短铗细蜉Caenis parviforcipis(Zhou et al.)n．comb．由短尾蜉属Brachycercus转移而来;中华细蜉Caenis sinensis Gui et al．稚虫形态在本文中首次描述;另外从标本来看,已知的黑铗细蜉Caenis nigroforceps Zhou et al．实际为近岸细蜉Caenis rivulorum Eaton的新异名;本文描述1新种：花斑细蜉Caenis melanoleuca,sp．nov．;第5种黑点细蜉Caenis nigropunctata Klapalek也根据标本得到了确认。文中还给出了以上5种成虫和4种稚虫的检索表。所有标本都保存在南京师范大学生命科学学院。     

Further evidence for the genetic origin of mutations in mammalian somatic cells: the effects of ploidy level and selection stringency on dose-dependent chemical mutagenesis to purine analogue resistance in Chinese hamster ovary cells.

Whether resistance to purine analogues 8-azaguanine (AG) and 6-thioguanine (TG) in mammalian cells is due to gene mutation or to epigenetic changes was investigated by an ethyl methanesulfonate (EMS) dose-dependent induced “resistance” to these analogues in two near-diploid (2N) and one tetraploid (4N) Chinese hamster ovary (CHO) cells. EMS produced higher cell killing in 2N than in 4N cells. In the 2N cells, EMS-induced mutations to TG (1.7 μg/ml) resistance increased approximately as a linear function of the dose from 0–400 μg/ml. However, EMS was ineffective in inducing such mutation in the 4N cells. These observations are consistent with the notion that the induced TG resistance arose as a result of mutation at the gene or chromosome level. In each cell type, both the “observed” spontaneous and the EMS-induced frequency to purine analogue resistance decreased with increasing concentration of purine analogues. However, among the “resistant” clones a high proportion of those selected at 1.2 and 3.0 μg/ml of AG, a small portion selected at 7.5 μg/ml of AG, and virtually none at 1.7 and 6.0 μg/ml of TG are capable of growth in medium containing aminopterin (10 μM). This suggests that, under less stringent selective conditions, some resistant variants were being selected through mechanisms not yet defined.     

靶向5-LOX中药黄酮类化合物的活性筛选及其作用方式和共性规律研究

筛选靶向结合炎症相关蛋白5-LOX(5-lipoxygenase,5-脂氧合酶)的中药黄酮类天然产物,分析与5-LOX结合的黄酮类成分及其来源中药的共性规律。本研究借助Discovery Studio 2017 R2分子对接和药效团构建模块,结合SPR分子筛选实验,以及关联网络构建的方法进行研究。研究结果显示,来源于17种中药的18个黄酮类小分子中有11个能够与5-LOX结合,并从分子对接以及药效团构建研究中发现其作用的3种方式和共性特征:(1)部分中药黄酮成分(如木犀草素等)通过结构中的B环与5-LOX在活性位点ASP243形成静电中心相结合;(2)部分中药黄酮成分(如芹菜素等)是通过结构中的A环与活性位点VAL520形成疏水键、与活性位点ASP243形成氢键与5-LOX结合;(3)杨梅苷等黄酮类成分由于极性较强,在没有形成疏水键的情况下,也是通过形成静电中心与5-LOX在活性位点ASP243产生相互作用。此外还发现靶向5-LOX的活性中药黄酮类化合物,大多来源于具有利湿、退黄等功效,性味甘苦寒的景天科中药中。本研究发现了部分靶向5-LOX的中药黄酮类成分及其作用方式和共性规律,为开发靶向5-LOX抗肿瘤新药提供思路和方法。     

Summer monsoon intensity controls C4/C3 plant abundance during the last 35 ka in the Chinese Loess Plateau: Carbon isotope evidence from bulk organic matter and individual leaf waxes

The natural abundance of C₃ and C₄ plants is affected by multiple environmental factors including temperature, moisture balance and atmospheric pCO₂. The relative importance of these factors is a subject of considerable debate, and may vary in different natural ecosystems. Previous studies generally focus on single loess sequences in the Chinese Loess Plateau, and conflicting conclusions on C₄/C₃ have been reached when studying carbon isotope ratios in carbonate and organic matter. In this paper we report a comprehensive carbon isotopic characterization of total organic carbon (TOC) and individual higher plant leaf waxes from five loess sequences spanning the last 35 ka from the Chinese Loess Plateau (CLP). The five coring sites encompass large gradients of annual mean temperature (9.2–13.9 °C) and precipitation (402–673 mm), allowing us to assess the controlling mechanisms on C₄/C₃ plant ratios. Glacial–interglacial sequences provide carbon isotope data for comparison with other climatic and environmental proxies such as lithology and magnetic susceptibility. Our results demonstrate that increased C₄/C₃ ratios are positively correlated with higher temperature and increased summer rainfall which characterize stronger summer monsoon in all five sites. We conclude C₄ abundance increases from the last glacial to the Holocene in response to greater monsoon activity and that the C₄ expression is suppressed in the cold and drier intervals.     

18种中草药提取物对褐飞虱和甜菜夜蛾的杀虫活性分析

为了筛选对农产品和环境安全、对害虫高效的植物源杀虫剂,分别采用喷雾法和饲毒法,测定了18种中草药的3种溶剂（水、乙醇、石油醚）提取物对褐飞虱Nilaparvata lugens Stål的触杀活性和对甜菜夜蛾Spodoptera exigua Hübner的胃毒作用。结果表明,各种提取物（0.8 g/mL）对甜菜夜蛾的胃毒作用不明显,校正死亡率最高为33.33%;但对褐飞虱的杀虫活性较高,其中百部、黄柏、榧子、生山栀、鹤虱、木香的乙醇或石油醚提取物,对褐飞虱3龄若虫的24 h校正死亡率均在80%以上,其石油乙醚提取物的LC50值依次为：0.0826,0.0455,0.0145,0.0047,0.0038,0.0033 g/mL。采用系统溶剂法分析发现,木香和鹤虱的主要杀虫活性成分均在氯仿萃取物中,表明其杀虫成分易溶于较弱极性溶剂中。进一步通过活性追踪法,对鹤虱提取物的柱层析各流分的活性检测表明,其杀虫活性成分的Rf值为0.5556~0.5926。该研究为进一步纯化新型植物源杀虫物质并确定其分子结构,从而开发其应用前景及发现新的杀虫活性先导化合物奠定了基础。