胶州湾大型底栖动物的物种多样性现状

自1998年2月－1999年11月对胶州湾的10个站进行了大型底栖动物分布状况调查,目的在于为进一步的胶州湾生物多样性变化及其保护研究,为胶州湾底栖生物资源的合理开发和持续利用提供科学依据和积累资料。初步分析结果显示,两年内各站春季和秋季的物种多样性指数偏低,冬季和夏季的指数较高,物种均匀度指数夏季最高,春季最低,物种丰富度指数以夏季最高,春季和冬季略同,秋季最低。1999年各站出现的底栖动物种数明显高于1998年,差异显著,生物多样性平均指数较1998年有所下降。     

胶州湾大型底栖软体动物物种多样性研究

1998年2月至2004年11月,共7年27个航次对胶州湾10个站进行综合调查,研究了其大型底栖软体动物的多样性现状(菲律宾蛤仔(Ruditapesphilippinarum)除外)并探讨其成因。结果表明:在胶州湾共发现62种底栖软体动物,优势种是滑理蛤(Theoralubrica)和豆形胡桃蛤(Nuculafaba)。从1998年至2004年期间物种多样性指数(H′)年际间波动幅度不大,且无明显的规律性变化;但季节变化明显,秋季和冬季较高,春季和夏季较低。物种均匀度指数(J)则为秋季最高(0.87),夏季最低(0.58)。物种丰富度指数(D)除夏季相对较低(1.82)外,其他三个季节差别不大。     

黄海特定断面夏秋季大型底栖动物生态学特征

根据2001年8月和2002年8、9、10月共4个航次,在黄海特定断面的10个站采集到的大型底栖动物样品,采用相对重要性指数、物种多样性指数、物种均匀度指数、物种丰度指数,Bray-Curtis相似性系数聚类分析和MDS标序等方法,分析了该区域大型底栖动物的生态学特性。调查共得到定量样品36个,经分析鉴定有大型底栖动物182种,其中多毛类环节动物54种,软体动物29种,甲壳动物66种,棘皮动物17种,其它类群生物16种。相对于邻近海区,物种丰富度指数较小,物种多样性指数相似,均匀度指数较高;各航次中4、5号站种数明显较少,而生物量和栖息密度没有表现出一定的规律性。通过该断面大型底栖动物的研究发现,可将研究区域的大型底栖动物群落分为沿岸广温性群落、温带性群落和暖水性群落,各群落结构保持相对稳定性;主要底栖动物种类组成在2001年和2002年出现较大变化,而在2002年的8、9、10月的种类组成保持相对稳定。     

胶州湾潮下带大型底栖动物群落的季节变化

胶州湾位于山东半岛南岸, 是黄海深入内陆的半封闭天然海湾, 底栖动物种类丰富。本文根据2014年2、5、8和11月4个航次(冬、春、夏、秋)的调查资料, 采用优势度指数, 物种多样性指数、丰富度指数、均匀度指数, Bray-Curtis相似性聚类和非参数多维标度排序(NMDS)方法, 分析了胶州湾大型底栖动物群落的季节变化特点。各航次共采集大型底栖动物199种, 其中多毛类79种, 甲壳动物47种, 软体动物40种, 棘皮动物17种, 其他类群16种。各季度优势种有变化亦有重叠, 以多毛类为主。2014年度胶州湾大型底栖动物的年平均丰度为209.85 ind./m², 最高丰度出现在秋季, 最低出现在春季; 年平均生物量为79.22 g/m², 最高生物量出现在夏季, 最低出现在春季。物种多样性指数(H')变化范围为2.16-2.86, 物种丰富度指数(D)变化范围为2.79-3.72, 物种均匀度指数(J)变化范围为0.58-0.82。聚类分析结果显示, 4个航次的群落相似性系数均较低, 分布格局存在季节性变化。近年来, 伴随海岸带开发及人类活动的持续影响, 胶州湾底栖生境的稳定性受到一定的威胁, 建议继续开展长期连续的监测, 探索有效的综合治理措施, 使胶州湾海洋生态系统能够持续健康的发展。     

象山港大型底栖动物生物多样性现状

2006年7月至2008年8月对象山港13个站位进行了8个航次的大型底栖动物采样调查.研究了该海域大型底栖动物群落的优势种组成, 大型底栖动物的丰度、生物量、次级生产力和P/B值,并采用物种丰富度指数、物种均匀度指数和物种多样性指数分析大型底栖动物物种的多样性.调查共获得大型底栖动物123种,其中软体动物48种,甲壳类33种,鱼类和环节动物多毛类各12种,棘皮动物8种,还包括一些腔肠动物、线虫等.群落中优势种较为集中,且优势度指数较高.该海域大型底栖生物年次级生产力平均值为16.70 ·m^-2·a^-1,平均P/B值为0.60.对物种丰富度指数(d)、均匀度指数( J )、辛普森多样性指数(D)和香农多样性指数(H)进行双因素方差分析表明,不同站位之间4种指数的差异均高度显著(P<0.01),周年之间4种指数的差异除均匀度指数不显著外(P>0.05),均高度显著(P<0.01).     

胶州湾西部海域大型底栖动物多样性的研究

为了揭示胶州湾最近几年底栖动物多样性的变化, 作者于2003年9月到2004年9月在胶洲湾西部海域5个测站每2个月1次共进行了7个航次采样, 以种类组成、生物量和栖息密度为基础, 对大型底栖动物多样性进行了分析。使用PRIMER软件计算得到以下变量: 群落的物种数(S)、丰富度(D)、Shannon-Wiener物种多样性指数(H')和均匀度指数(J')。结果表明: 位于大沽河口的D站和水道中央的S站的多样性最低; 养殖区内外站位的多样性差异显著; 丰度/生物量曲线表明, 养殖区内的底栖动物群落已经受到了一定程度的扰动。群落物种数(S)和丰富度(D)的季节性变化明显, 春季和秋季较低, 夏季和冬季较高。分析菲律宾蛤仔(Ruditapes philippinarum)增养殖区的站位(D)发现, 多样性指数和丰富度与次级生产力有着负相关的关系。物种多样性指数和丰度/生物量曲线的分析显示, 该研究海域处于一个轻度人为扰动的状态。     

海南东寨港红树林滩涂大型底栖动物多样性的初步研究

记录到海南东寨港红树林滩涂大型底栖动物68种,其中软体动物39种,占记录到物种数的57.4%;甲壳动物19种,占记录到物种数的27.9%。冬季优势种是珠带拟蟹手螺(Cerithidea cingulata )、古氏滩栖螺(Batillaria cumingi )和环肋樱蛤(Cyclotellina remies );夏季优势种是珠带拟蟹手螺、环肋樱蛤和红肉河蓝蛤(Potamocorbula rubromuscula )。大型底栖动物的生物量夏季平均为133.0 g/m²,冬季平均为63.0 g/m²; 栖息密度夏季平均为106.4 个/m²,冬季平均为103.5 个/m²。以密度为计量单位的物种多样性指数夏季为1.841,冬季为0.380,均匀度指数夏季为0.514,冬季为0.112;以生物量为计量单位的物种多样性指数夏季为1.994,冬季为1.751, 均匀度指数夏季为0.556,冬季为0.520。大型底栖动物的生物量、栖息密度、物种多样性指数和均匀度指数大都有季节变化及底质差异,基本趋势是夏季明显高于冬季,沙泥底的滩涂高于泥底质的滩涂。     

长江口及毗邻海域大型底栖动物的空间分布与历史演变

于2005～2006年进行的4个航次调查中,分别对长江口及毗邻海域进行了大型底栖动物取样工作.4个航次共发现大型底栖动物330种,其中包括软体动物122种,多毛类83种,甲壳动物67种,棘皮动物23种,底栖鱼类28种,以及其它类群7种.调查区内大型底栖动物的平均栖息密度为(146.4 ± 22.3)个/m2,平均生物量为(12.8 ± 2.3) g/m2,平均香农指数、丰富度指数与均匀度指数分别为1.72 ± 0.16、1.37 ± 0.19、0.64 ± 0.04.研究表明,调查区内的底栖生物自西向东、由近岸向外海大致可分为3个等级:在最西侧的口内水域与杭州湾,底栖生物种类组成最为单调,生物多样性指数最低,群落结构极为脆弱;在紧邻该底栖生物贫乏带的东侧,也就是口外水域与舟山海区,底栖生物种类组成呈现复杂化,生物多样性指数较高,群落结构显著好于口内水域及杭州湾;在调查海域东南侧的近海区,底栖生物的种类组成最为复杂,生物多样性指数最高,群落结构最为稳定.近半个世纪以来,长江口冲淡水区大型底栖动物的总生物量未出现明显变化,其值在20 g/m2左右变动,但各生态类群的优势地位发生了显著更替.个体较小、生长周期较短的多毛类取代个体较大、生长周期较长的棘皮动物,成为目前冲淡水区最重要的优势类群.     

庙岛群岛南部海域大型底栖动物多样性

为了解庙岛群岛南部海域大型底栖动物群落多样性变化,我们在该海域设置了11个站位,于2012年11月、2013年2月、5月、8月共进行了4个航次的调查,对该海域大型底栖动物的生物多样性变化、种类组成以及优势种等进行了分析。在研究海域共采集到大型底栖动物164种,包括环节动物多毛类82种,节肢动物甲壳类38种,软体动物30种,棘皮动物9种,其他类群5种。各站位种类数在6–42种之间。物种数冬夏较多、春季较少。各站位Shannon-Wiener多样性指数未呈现明显的季节性变化;均匀度指数春夏最高;而丰富度指数春夏两季最低。沉积物中有机质与叶绿素含量是影响大型底栖动物多样性的主要因素。丰度–生物量比较曲线(ABC曲线)结果表明,位于庙岛与北长山岛之间的C13站、毗邻庙岛的C17站和C28站的底栖动物群落受到了中等程度的扰动,其余站位未受到明显扰动。     

胶州湾西北部潮滩湿地大型底栖动物功能群

2009年2、5、8和11月进行了7个断面35个站位的大型底栖动物调查,选取高潮区(A)、中潮区(B、C、D)和低潮区(E)研究了胶州湾西北部潮滩湿地大型底栖动物功能群组成及其时空变化.调查共发现大型底栖动物71种,主要种类为软体动物(31种)、环节动物(20种)和节肢动物(14种).潮区A、B、C、D、E物种数分别为26、33、35、38、31.依据食性将主要底栖动物划分为肉食者、浮游生物食者、碎屑食者和杂食者4个功能群.各功能群物种数占总物种数的百分比由高到低依次是肉食者、浮游生物食者、碎屑食者和杂食者.各功能群中肉食者的多样性指数最高,杂食者最低.各功能群的丰度、均匀度指数、多样性指数一般都是中潮区较高,高潮区和低潮区较低.大型底栖动物功能群的分布随潮区环境的改变而变化,是对生境状况的综合反映.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.