Optimization of crude enzyme preparation methods for analysis of glutamine synthetase activity in phytoplankton and field samples

Glutamine synthetase (GS) is an important enzyme involved in nitrogen assimilation and metabolism in marine phytoplankton. However, little work has been done in situ due to the limitation of crude enzyme preparation methods. In this study, three enzyme preparation methods, high-speed centrifugation (HC, <10 000 g), ultracentrifugation (UC, 70 000 g), and ultrafiltration (UF) with 100 k mu molecular weight cutoff, were compared using two diatom species (Asterionellopsis glacialis and Thalassiosira weissflogii), and two dinoflagellate species (Alexandrium catenella and Prorocentrum donghaiense) as experimental materials together with field samples collected from Xiamen Harbor, China. The results showed that HC is the best method to prepare crude enzymes for glutamine synthetase activity (GSA) in diatom species and diatom-dominant samples, while UF is the best method to extract GS from dinoflagellate species and dinoflagellate-dominant samples. For the HC method, the optimal centrifugal speed and time were 10 000 g and 35 min, respectively, and under these conditions, the highest GSA was obtained in all samples. This study indicates that both methods (HC and UF) overcome the limitation of centrifugal speed and could be applied to in situ GSA analysis, especially at sea.The National Natural Science Foundation of China [40331004]; Ministry of Science and Technology of China [2005DFA20430

固定化双酶耦联体系制备手性胺

胺脱氢酶(amine dehydrogenase,Am DH)能够在辅酶的作用下不对称还原前手性酮制备手性胺,并与甲酸脱氢酶(formate dehydrogenase,FDH)构建耦联双酶反应体系,通过酶活检测与高效液相色谱法得出,Am DH和FDH浓度比为4∶1、底物浓度为10 mmol/L、辅酶浓度为0. 025 mmol/L时,是游离双酶耦联体系最优反应条件.为提高双酶耦联体系的稳定性,将聚乙烯亚胺-双酶复合物作为模板和催化剂,诱导钛前驱体Ti-BALDH(titanium(IV) bis-(ammoniumlactato)-dihydroxide)缩聚,形成固定化耦联体系.与游离酶体系相比,辅酶可在固定化酶体系的微环境中高效循环再生,大大提高了多酶耦联体系的催化效率

卷积神经网络模型在儿科疾病预测中的应用

目的:针对儿童看病需求量大导致的儿科诊疗服务效率和准确率偏低等问题,利用自然语言处理和深度学习技术,从儿科历史病历数据中自动\"学习\"专家医生诊断模式,形成智能辅助诊断模型,从而对新的儿科病历数据输出疾病诊断决策。结果:基于深度卷积神经网络的七分类疾病智能诊断模型的正确率为84.26%,F1-score为84.33%,基本达到可投入实际应用的级别。结论:智能诊断决策作为预诊信息提供给医生进行确诊参考,对提升医生诊断速度效果明显。国家自然科学基金面上项目(编号:71571056);;福建省自然科学基金面上项目(编号:2012J01274)~

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

Effects of Self-interest on Attitude During High Personal Involvement

目的:考察个人利益与青少年社会态度之间的关系及发展趋势。方法:以高考政策改变的提案作为高自我卷入事件,控制被试的利益得失,让被试预测他人的态度并表达自己的态度。结果:16岁的儿童组和21岁的大学生组被试不仅预测同伴的态度与个人利益一致,而且他们自己的态度也与个人利益一致; 13岁儿童组被试并没有根据个人利益原则来预测同伴的态度或表达自己的态度。结论:自我利益卷入程度高时,随着个体年龄增长,个体会认为他人态度受个人利益的影响,个体自己也会表达同个人利益一致的态度

厦门同安湾红树林及临近光滩沉积物孔隙水中溶解无机磷和亚铁分布特征的对比分析

为了解红树林与光滩磷、铁地球化学行为的差异,借助薄膜扩散梯度技术（ZrO-Chelex DGT）,对厦门同安湾红树林及临近光滩孔隙水中溶解活性磷（DRP）、Fe2+浓度进行了原位测量,并采集了相应沉积物柱状样进行测定分析。结果表明:（1）Fe2+与DRP呈现较好的线性正相关,说明磷的吸附/解吸与铁氧化还原循环有关;（2）在不同深度,光滩孔隙水中DRP浓度均高于对应深度红树林。在浅层,由于溪水的补给造成光滩的磷富集;在深层,红树植物根部吸收导致磷浓度下降,光滩有机质含量较多,矿化释放DRP使其浓度较高;（3）孔隙水中的Fe2+浓度分布表明,红树林区域随着深度的增加,逐渐由好氧环境进入厌氧环境;而光滩沉积物氧化还原环境可能受到红树林的影响,孔隙水Fe2+在垂向上波动分布。国家自然科学基金项目(No:41672226; 41372242

厦门同安湾红树林及临近光滩沉积物孔隙水中溶解活性磷和亚铁分布特征的对比分析

为了解红树林与光滩磷、铁地球化学行为的差异,借助薄膜扩散梯度技术（ZrO-Chelex DGT）,对厦门同安湾红树林及临近光滩孔隙水中溶解活性磷（DRP）、Fe2+浓度进行了原位测量,并采集了相应沉积物柱状样进行测定分析。结果表明:（1）Fe2+与DRP呈现较好的线性正相关,说明磷的吸附/解吸与铁氧化还原循环有关;（2）在不同深度,光滩孔隙水中DRP浓度均高于对应深度红树林。在浅层,由于溪水的补给造成光滩的磷富集;在深层,红树植物根部吸收导致磷浓度下降,光滩有机质含量较多,矿化释放DRP使其浓度较高;（3）孔隙水中的Fe2+浓度分布表明,红树林区域随着深度的增加,逐渐由好氧环境进入厌氧环境;而光滩沉积物氧化还原环境可能受到红树林的影响,孔隙水Fe2+在垂向上波动分布。国家自然科学基金项目(41672226; 41372242)~

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

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