162 research outputs found
Characterization of a Novel Alternatively Spliced Variant from Human FMR1 Gene and Function of Its Encoded Product
脆性X智力障碍1基因(fragileXmentalretardation1gene,FMR1)编码一个选择性RNA结合蛋白,称脆性X智力低下蛋白(fragileXmentalretardationprotein,FMRP)。该蛋白表达减少或缺失可导致一种常见的遗传性智力缺陷疾病,称脆性X综合征(fragileXsyndrome,FXS)。FMR1基因的可变剪接与FMRP蛋白表达关系密切。不同的剪接方式会产生不同的转录本,最后导致FMRP蛋白的结构和功能发生改变,且相应的信号通路也受到影响。但对不同剪接异构体的检测及其生理功能仍研究较少。我们在先前的研究中采用克隆-测序技术,从RNA途径分析人F...Fragile X mental retardation 1 gene (FMR1) encodes a selective messenger RNA-binding protein, which is called fragile X mental retardation protein (FMRP). Its absence can cause to a common form of inherited intellectual disability, known as fragile X syndrome (FXS). The alternative splicing of FMR1 gene has a close relationship with FMRP expression. Different ways of splicing will produce differen...学位:医学硕士院系专业:医学院_临床检验诊断学学号:2452014115352
Design of an MAC protocol for distributed wireless network with low power consumption
为了提高分布式全双工无线网络的能量效率,提出了一种改进的低功耗全双工媒体访问控制(MAC)协议.不同于传统的MAC协议,该MAC协议通过降低数据包以及确认包的传输功率来实现能量有效性.提出的MAC协议支持双向以及单向两种链路,并保持对传统半双工节点具有向后兼容性,实现了较高的吞吐量.通过基于随机几何的方法对提出的MAC协议进行了仿真分析与性能评估,结果证明了其有效性和准确性,是全双工无线网络可行的一种解决方案.In order to improve the energy efficiency of the distributed full duplex wireless network, an improved full duplex medium access control (MAC) protocol with low power consumption was proposed. Unlike the traditional MAC protocol, the proposed MAC protocol could achieve the energy efficiency through reducing the transmission power of data and acknowledgement packets. The proposed MAC protocol supported both bidirectional and unidirectional links, and maintained the backward compatibility to the traditional half duplex nodes, which could achieve a high throughput. The simulation analysis and performance evaluation for the proposed MAC protocol were carried out based on the random geometry method. The results verify the effectiveness and accuracy of the proposed method. The proposed method is a feasible solution scheme for the full duplex wireless network. ? 2017, Editorial Department of Journal of Shenyang University of Technology. All right reserved.国家文化部科技创新资助项目(WHBKJCXXM20142554);国家文化部科技提升资助项目(GJWHKJTSXM20151991); 江苏省高等教育教改课题资助项目(2015jsjg411
鼠腹腔中弓形虫的增殖发育及S.D.对其的影响
对鼠腹腔中弓形虫速殖子的增殖发育的方式、过程及 S.D.对其的影响作了详细的考察 ,结果表明弓形虫的无性生殖方式有内二裂殖、纵二裂殖、裂殖生殖等 ,虫体以鼠腹腔内巨噬细胞的胞壁作为假包囊壁在其中增殖发育 ,经过 72 h的增殖生长 ,虫体成熟后突破假包囊逸出 ,S.D.可部分抑制速殖子增殖
Diet composition of Difflugia tuberspinifera( testate amoeba) based on a clone library technique
瘤棘砂壳虫是东亚特有的原生动物,广泛分布于长江与珠江中下游以及福建地区的湖泊和水库,作为水生态系统的捕食者,在维持水生态系统的结构与功能方面发挥着重要作用。利用18S rrnA基因PCr扩增和克隆文库测序等分子生物学技术方法,从基因水平研究瘤棘砂壳虫的食物组成。结果表明:所获得的46条序列在97%相似度水平含有11类OTuS(OPErATIOnAl TAXOnOMIC unITS,操作分类单元),其中包括轮虫6个,桡足类5个,说明瘤棘砂壳虫的捕食类群以轮虫和桡足类为主,同时也证明单细胞生物可以直接以多细胞的后生动物为食。此外,通过克隆文库测序技术分析原生动物的食物组成比例,不仅是一种方便、高效、快速,重复性高的方法,同时也为分析原生动物的生态功能提供了一种新的视角。Difflugia is a morphologically diverse genus of the free-living shelled amoeboid protozoa that are important components of freshwater ecosystems and play crucial roles in nutrient cycles and energy flow through food webs.Difflugia tuberspinifera is an endemic species of East Asia and is widely distributed in freshwater lakes and reservoirs in China.Clearly,this species plays a critical role in maintaining the structure and function of freshwater ecosystems.However,little is known about its diet composition and predatory behavior at both species and gene levels.This testate amoeba( D.tuberspinifera) was first found in the Wujiang River,Guizhou Province,China.Subsequently,more detailed studies on its morphology and biometry have been done on natural populations from Yangtze River and Pearl River valleys,and Fujian reservoirs.Recently,Han et al.illustrated that D.tuberspinifera is an active and agile hunting carnivore that can capture swimming prey including micro-particulates,rotifers,and other metazoans.In previous studies,however,the specimen identifications were done by microscopic examination,which requires a broad and deep taxonomic knowledge and is verylaborious,time-consuming,and somewhat variable because of insufficient taxonomic resolution.In order to facilitate the identification of diet composition in D.tuberspinifera,an inexpensive,efficient,rapid and easy-to handle gene clone library has been developed for diet detection and analysis.The plankton samples were collected from the Hubian Reservoir in Xiamen city in September of 2010.Individual cells were isolated using a glass capillary under an inverted microscope and washed 3—5 times with distilled water before DNA extraction and PCR amplification.The 18 S rRNA gene was amplified by the universal eukaryotic primers,and the purified PCR products were ligated into the p GEM-T vector and transformed into Escherichia coli DH5α-competent cells.In total,46 plasmids containing target gene fragments were successfully identified and sequenced.Each sequence was compared with sequences available in the Gen Bank database using BLAST,and the closest relatives were identified for diet or food composition analysis.Finally,11 OTUs( operational taxonomic units) were identified at 97% sequence similarity level,and they belonged to either Rotifera( 52%) or Copepoda( 48%).Our results,combined with existing data,suggested that:1) the diet composition of Difflugia tuberspinifera is composed of both rotifera and copepoda species;2) unicellular protozoa are not only the food of metazoa,but they can also prey on multicellular micro-metazoa;3) molecular methods are universally applicable,and the SSU rRNA( small subunit ribosomal RNA) gene clone library is an efficient,rapid,and repeatable approach to study the diet composition of protozoa.国家自然科学基金项目(31172114;30800097); 福建省杰出青年科学基金项目(2012J06009
MRI-T2*检测β-重型地中海贫血心、肝、胰铁沉积的临床价值
目的MRI-T2*定量评价β-重型地中海贫血(β-TM)患者心肌、肝脏、胰腺铁沉积程度,探讨心肌铁沉积与肝脏、胰腺铁沉积的关系。方法回顾性分析2014年5月至2016年1月期间在我院行心脏、肝脏、胰腺MRI-T2*检查的109例β-TM患者的临床、实验室和MRI资料,采用Spearman相关性分析探讨心肌T2*值与肝脏、胰腺T2*值之间关系。将心肌、肝脏铁沉积的患者纳入A组(n=32),仅肝脏铁沉积、而心肌铁含量正常的患者纳入B组(n=69),将心肌、胰腺铁沉积的患者纳入C组(n=34),仅胰腺铁沉积、而心肌铁含量正常的患者纳入D组(n=58),采用两独立样本比较的Wilcoxon秩和检验比较A组与B组肝脏T2*、C组与D组胰腺T2*值的差异。绘制用肝脏、胰腺R2*(1/T2*)预测心肌铁沉积的ROC曲线。结果109例β-TM患者的心肌、肝脏、胰腺T2*中位数分别为27.7(3.2~45.4)ms 、1.8(0.7~18.6)ms及6.1(1.1~42.9)ms;诊断心肌铁沉积(T2*<20 ms)34例(31.2%),肝脏铁沉积(T2*<6.3 ms)101例(92.7%),胰腺铁沉积(T2*<26 ms)92例(84.4%);诊断心肌铁沉积最小年龄7岁,肝脏和胰腺铁沉积最小年龄均为5岁。心肌T2*值与肝脏、胰腺T2*值均呈正相关(r分别为0.453、0.597, P均<0.001)。A组肝脏T2*值低于B组(Z=3.048,P=0.002),C组胰腺T2*值低于D组(Z=6.682,P<0.001)。肝脏、胰腺R2*(1/T2*)预测心肌铁沉积的ROC结果如下:曲线下面积分别为0.660(P=0.009)、0.933(P<0.001),95%置信区间分别为 (0.543~0.777) 、(0.881~0.985)。结论β-TM患者肝脏、胰腺铁沉积的发生较早、且普遍,早于心肌铁沉积。肝脏、胰腺铁沉积与心肌铁沉积相关,两者结合可用于预测心肌铁沉积的情况
An ecological study on zooplankton in the northern Beibu Gulf V: the effects of microzooplankton grazing on phytoplankton in summer
2011年8月份于北部湾北部海域5个观测站位获得的分层水样,分析了表层叶绿素A含量和表层微型浮游动物丰度以及类群组成;同时于现场采用稀释培养法研究了该海域浮游植物生长率(μ)和微型浮游动物的摄食率(g)。分析和测定结果表明:调查海区的微型浮游动物丰度400—1167个/l,类群组成以无壳纤毛虫为主;浮游植物的生长率为-1.50—1.13 d-1,微型浮游动物摄食率为0.33—1.08 d-1;推算微型浮游动物对浮游植物现存量以及初级生产力的摄食压力分别为28.1%—66.0%和-7.4%—438.4%。相对于中国其他海区,8月份北部湾北部海域微型浮游动物摄食速率处于中等水平。调查期间,广西沿海高生产力海区,浮游植物生长率大于微型浮游动物动物的摄食率,浮游植物生物量处于积累期;涠洲岛以南海域,浮游植物生产力较低,微型浮游动物摄食作用是控制浮游植物生长的重要因素。In August 2011,we quantified the impact of microzooplankton grazing on phytoplankton production in the surface waters of the northern Beibu Gulf,Vietnam.Shipboard dilution incubation experiments were carried out at five stations to calculate phytoplankton specific growth rates and the specific rates of grazing losses to microzooplankton.Dilution experiments using chlorophyll a( Chl a) as a tracer were used to estimate daily rates in two size fractions; image-analyzed microscopy provided quantitative estimates of microzooplankton standing stock( including ciliate and vertebrate larvae).PFW( particle-free water) was used to dilute seawater to five target dilutions of 0%,20%,40%,60%,and 80%.Microzooplankton grazing and phytoplankton growth rates were estimated by the linear regression of AGR( apparent growth rate) versus dilution factor.We estimated the grazing impact of microzooplankton on phytoplankton by calculating the percentage of phytoplankton standing stock and potential primary production ingested.Average total chlorophyll a concentration was( 0.67 ± 0.58) μg / L.Small-celled phytoplankton dominated this particular community.A notable characteristic of the phytoplankton community structure was that nano- and picoplankton made up a significant portion.Aloricate ciliates dominated the microzooplankton samples,in particular Strombidium,which accounted for 27.2% of total aloricate ciliate abundance.In addition,loricate ciliates and copepod nauplii were recorded.Microzooplankton densityvaried from 400 to 1167 ind / L.The horizontal distribution of microzooplankton was greater in nearshore than in offshore waters.Abundance did not differ significantly with chlorophyll a concentration in this study; however,there was a positive correlation between microzooplankton abundance and temperature.The phytoplankton growth rate( < 200 μm) ranged between-1.50 and 1.13 d-1,with the highest values being associated with nearshore waters.Meanwhile phytoplankton mortality due to microzooplankton grazing( 0.33—1.08 d-1) was highest at the same nearshore sites; however,growth rates were low at these sites.Consequently,microzooplankton consumed 28.1%—66.0% of chlorophyll a standing stocks and-8.1%—438.4% of the primary production per day.However,the grazing rate of microzooplankton on nanoplankton( 2— 20 μm) varied from 1.87 to 0.52 d-1,with an average of( 0.94±0.57) d-1.Given that the rates of grazing on phytoplankton of <200 μm were lower than those on nanoplankton,we conclude that microzooplankton prefer to graze on nanoplankton.There was a positive correlation between phytoplankton growth rate and grazing rate; in addition,significant differences between grazing rate and chlorophyll a were found.This suggests that microzooplankton grazing activity is the main factor regulating the community structure and restraining the growth of phytoplankton.During the investigation period, microzooplankton grazing effectively controlled the growth of phytoplankton,consuming 176.2% of primary production on average.When grazing rates are far greater than phytoplankton growth rates,energy is transferred from lower to higher trophic levels more effectively.In the surface waters of the northern Beibu Gulf,microzooplankton largely control the growth of phytoplankton by grazing offshore rather than in nearshore waters where primary production is high.The growth and grazing rates combined promote planktonic ecosystem stability in this area.These results indicate that grazing by microzooplankton is a key process controlling the growth of phytoplankton in this area.海湾公益项目(201005012
The relationship between nutrients and phytoplankton community structure in northern Beibu Gulf
根据2011年4月和8月北部湾北部(北部湾20°n以北的海域)的调查数据,北部湾北部春夏两季共鉴定出浮游植物312种,隶属于4门78属,硅藻是主要优势类群。春季优势种为细弱海链藻(THAlASSIOSIrA SubTIlIS)、丹麦细柱藻(lEPTOCylIndruS dAnICuS)、奇异棍形藻(bACIllArIA PArAdOXA)和尖刺拟菱形藻(PSEudOnITzSCHIA PungEnS);夏季优势种仅为海链藻(THAlASSIOSIrA SP.)。浮游植物群落在春季可划分为2个子群落(SPr1和SPr2),在夏季可划分为3个子群落(SuM1、SuM2和SuM3)。该海域n/P比值一直处于高的水平,绝大部分的水域表现为磷限制,这可能是硅藻大量生长所造成的。春季SPr2群落优势种的柔弱角毛藻(CHAETOCErOS dEbIlIS)与除铵盐之外的营养盐具显著相关关系,奇异棍形藻与环境因子无相关关系。夏季SuM3群落优势种的奇异棍形藻与磷酸盐具显著相关关系。分析表明,琼州海峡过道水为北部湾北部输送了磷酸盐,而硅酸盐则主要由陆地径流输入。Phytoplankton community and nutrient concentration in the northern Beibu Gulf in April and August 2011 were investigated.In this research, 312 phytoplankton taxa were identified, which belonged to four phyla and 78 genera, with Bacillariophyta being the main group.The dominant species were Thalassiosira subtilis, Leptocylindrus danicus, Bacillaria paradoxa, and Pseudonitzschia pungens in spring, and Thalassiosira sp.in summer.Phytoplankton community in northern Beibu Gulf could be divided into two natural groups in spring(spr1 & spr2) and three in summer(sum1, sum2 & sum3).N/P ratio was in a relatively high level in the study area, and most of the waters were phosphorus limitated which resulted from diatom blossom.Chaetoceros debilis was the dominant species of group spr1 and had significant correlation with nutrient in spring, except for ammonium.Bacillaria paradoxa was the dominant species of group sum3 and had significant correlation with phosphate in summer, but, it was uncorrelated with any environmental factors as the dominant species of group spr2 in spring.Phosphate was transported to northern Beibu Gulf through the Qiongzhou Strait corridor water, and silicate was input by land runoff.海洋公益性行业科研专项项目(201005012
Ecosystem structure and function in northern Beibu Gulf: zooplankton spatial niche and its differentiation
根据2006—2007年北部湾北部海域4个航次调查资料,采用k-优势度曲线法对浮游动物种(类)群进行排序分析,运用lEVInS公式和PIAnkA指数分析了主要优势种(类)群的生态位宽度值和生态位重叠程度,并通过除趋势典范对应分析(dCCA)研究生态位分化状况。结果表明,该海区浮游动物优势种(类)群按生态位宽度值可划分为广生态位、中生态位和窄生态位三大类型。其中,广生态位的种(类)群如肥胖软箭虫、亚强次真哲水蚤、长尾类幼体等具有较强的生态适应性,生活范围较广;窄生态位的种(类)群,对环境的适应性较差,对海流和水团等环境因素的变化具有指示意义。生态位宽度能够反映种(类)群丰度季节变化,但不能反映具体丰度大小。北部湾北部全年主要优势种(类)群的生态位宽度值介于0.08—0.77之间,并且各优势种(类)群的生态位宽度差异较大,种对间生态位重叠值介于0.02—0.89之间,平均生态位重叠指数为0.45,种(类)群之间利用资源环境的互补性较强,这与海域内生境多样化并且各优势种对环境适应能力的差异存在一定联系。dCCA分析表明,影响浮游动物分布的主要因子是水深、温度和盐度,其次是叶绿素A和溶解氧。The concept of ecological niche had remained as one of the core ideas in ecological research for almost a century,which was closely linked with interspecific competition,resource utilization had played an important role in the study of community composition and function,of the relationships among species,biodiversity,community succession and population evolution.Based on four seasonal investigations( Spring 2007,Summer 2006,Autumn 2007 and Winter 2006) in northern Beibu Gulf from 2006 to 2007,the niche breadth,niche overlap,spatial differentiation and environment effects on the abundance and spatial distribution of zooplankton were studied with qualitative and quantitative methods.The cumulative top 80% of zooplankton dominant populations were selected by the K-dominant curve method,then the niche breadths and their overlaps of zooplankton were measured using the formulas proposed by Levins Niche Breadth index and the Pianka Niche Overlap index,and the spatial niche differentiation was studied by using Detrended Canonical Correspondence Analysis( DCCA) method.The results showed that the zooplankton dominant species in northern Beibu Gulf were classified in to three groups,i e.,wide niche breadth groups( Bi= 0.60—0.77),middle niche breadth groups( Bi= 0.30—0.60),narrow niche breadth groups( Bi= 0.08—0.30) based on the niche breadth value.The niche breadths of zooplankton such as Sagitta enflata,Subeucalanus subcrassus and Macrura larvae were wider,which was related with their own characteristics and the capability of adapting environment,while the species whose niche breadths were narrower such as Doliolum denticulatum and Dolioletta gegenbauri will be considered as an indicative significance for ocean currents and water masses.Niche breadth could reflect the zooplankton abundance with the seasonal dynamic changes,and also could objectively reflect the species in the habitat in which the distributions of degree but it could not reflect the Accurate zooplankton abundance.The niche breadth values of dominance zooplankton species ranged between 0.08 and 0.77 in the whole year and The niche breadth difference among the dominant populations was great; The niche overlap values of dominance zooplankton species ranged between 0.02 and 0.89 in the whole year and the average niche overlap index was 0.45,there was strong complementarity in terms of the utility of resource among zooplankton populations,which had certain relationship with northern Beibu Gulf habitat diversification and the strong complementarity in terms of the utility of resource among zooplankton populations.The Detrended Canonical Correspondence Analysis result showed that depth,temperature and salinity had more important influence on the species spatial distribution than Chlorophyll a and dissolved oxygen.海湾公益项目(201005012); 我国近海海洋综合调查与评价专项(908-01-ST09
基于带权词格的循环神经网络句子语义表示建模
目前,循环神经网络(recurrent neural network, RNN)已经被广泛应用于自然语言处理的文本序列语义表示建模.对于没有词语分隔符的语言,例如中文,该网络以经过分词预处理的词序列作为标准输入.然而,非最优的分词粒度和分词错误会对句子语义表示建模产生负面作用,影响后续自然语言处理任务的进行.针对这些问题,提出基于带权词格的循环神经网络模型.该模型以带权词格作为输入,在每个时刻融合多个输入向量和对应的隐状态,融合生成新的隐状态.带权词格是一种包含指数级别分词结果的压缩数据结构,词格中的边权重在一定程度上体现了不同分词结果的一致性.特别地,利用词格权重作为融合函数中权重建模的监督信息,进一步提升了模型句子语义表示的学习效果.相比于传统循环神经网络,该模型不仅能够缓解分词错误对句子语义建模产生的负面影响,同时使得语义建模具有更强的灵活性.在情感分类和问句分类2个任务上的实验结果证明了该模型的有效性.国家自然科学基金项目(61672440);;北京语言大学语言资源高精尖创新中心资助;;国家语言文字工作委员会一般项目(YB135-49);;中央高校基本科研业务费专项资金项目(ZK1024);;苏州大学江苏省计算机信息处理技术重点实验室开放课题(KJS1520)~
Bacterial community and its relation to environmental variables in a subtropical stratified reservoir for drinking water supply in autumn
水库在我国东南沿海地区是重要的饮用水水源地,对地区经济发展和社会稳定起到重要作用。选择亚热带地区典型的热分层水库——福建莆田东圳水库,于2011年秋季稳定分层期,以水体温度的垂直变化特征为依据进行分层采样。应用PCrdggE和克隆测序的方法研究浮游细菌群落的垂直分布特征,利用多元统计分析揭示细菌群落与热分层水体理化指标之间的关系。结果显示:溶解氧、电导率、叶绿素A、总氮、氨氮及硝氮在上下层水体中的分布有显著差异,下层缺氧区细菌的SHAnnOnWIEnEr指数和dggE条带数明显高于上层好氧区,表明东圳水库热分层水体中存在明显的物理、化学及生物分层现象。测序结果表明β-变形菌可能是东圳水库中占优势的细菌类群,统计结果提示溶解氧是显著影响细菌群落组成的环境因子。热分层水体的物理化学分层与水体细菌群落结构密切相关,提示水库生态学研究应对水体热分层给予重视。Fujian reservoirs in southeast China are important water resources for economic and social sustainable development,although few have been studied previously.Dongzhen Reservoir,a typical subtropical stratified reservoir in Fujian,was chosen for investigation of bacterial distribution,composition and diversity in autumn 2011.As the only built large reservoir in Putian City,it plays an important role in irrigation,flood control,hydroelectric power,and water supply.Dongzhen Reservoir shows an obvious phenomenon of water thermal stratification during summer and autumn,thus creates a unique gradient of environmental variables along the water column.We investigated the bacterial community and its relation to environmental variables in this study for a better understanding of vertical distribution of bacterial community and theprimary environmental drivers in a stratified reservoir.Five water samples were collected from five different depths according to the vertical changes of temperature.Both PCR-DGGE and sequencing were used to investigate the bacterial community and diversity.Moreover,physical and chemical parameters were measured according to the national standard methods.Multivariate statistical techniques were used to examine the relationship between bacterial community and environmental variables.Principal component analysis( PCA) clearly showed that water temperature,dissolved oxygen( DO),chlorophyll a( Chl a),total nitrogen( TN),ammonia nitrogen( NH4-N),nitrite / nitrate nitrogen( NOx-N) and electric conductivity of the upper aerobic zone were differed from those of the deeper anoxic zone.Both the number of DGGE bands and the Shannon-Wiener index of the deeper anoxic zone were higher than those of the upper aerobic zone.Further,two groups were distinguished by the cluster analysis of bacterial communities based on the Bray-Curtis similarity.Thus,Dongzhen Reservoir presented an obviously physical,chemical,and biological stratified phenomenon.Seven bands that common to all sampling depths were extracted and sequenced,and among which four were identified as Betaproteobacteria,indicating that Betaproteobacteria were the most dominant taxa in Dongzhen Reservoir in autumn.Bacterial community composition and diversity differed greatly among different sampling depths,and these differences were closely related to the physical and chemical stratification of the water body.Redundancy analysis( RDA) demonstrated DO was the significant environmental variable that shaping the bacterial community and diversity( P < 0.01).Therefore,we should pay more attention to DO and thermal stratification of reservoirs for sustainable reservoir management.国家重大科学研究计划(2012CB956103); 中国科学院知识创新工程方向项目(KZCX2-YW-QN401); 国家自然科学基金面上项目(31172114); 福建省杰出青年科学基金项目(2012J06009
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