以浮游植物评价达赉湖水质污染及营养水平

1987—1988年在30个样点,四季采样,对达赉湖的浮游植物进行了种类组成,生物量、种群数量、优势种、污染指示种、硅藻指数、综合指数等群落生态学的初步研究,应用后五项参数对达赉湖水质污染及营养水平进行了评价。达赉湖浮游植物年均值达54.7×106个/L(细胞数,或个体数为2.3×106个/L),硅藻指数为149.3,综合指数为5.6。群落组成中污染指示种占65%,春季以绿藻的十字藻、卵囊藻为优势种,其它3个季节均以蓝藻中的微囊藻、鱼腥藻、腔球藻占优势,表明达赉湖已受到中等程度污染,属于蓝、绿藻型富营养湖。       

以浮游植物评价巢湖水质污染及富营养化

对巢湖浮游植物在22个样点,四季采样,进行了种类组成、种群数量、优势种、污染指示种,多样性指数及硅藻指数等群落生态学的初步研究。选用其中种群数量、优势种、污染指示种、硅藻指数对巢湖水质污染及营养水平进行了总评与分区评价。就巢湖总体而论,藻量年均值达111×10~6个/升(细胞数,或个体数为14.7×10~6个/升),硅藻指数96.7,群落组成种类中,污染指示种占64.2％,除冬季外,各样点多以微囊藻、鱼腥藻为主的蓝藻占优势,其分布频度年平均达98.8％,多度年平均达79.7％,而在夏、秋季,两者则分别为100和99.7％,表明巢湖已受到中等程度的污染,属蓝藻型富营养湖泊;与过去巢湖浮游植物的调查资料对比,表明最近几年来,人为富营养化进程在加速。     

四十里湾营养状况与浮游植物生态特征

研究了2006-2010年5月、8月和10月四十里湾的营养盐结构、海水营养级、有机污染状况、浮游植物数量及多样性变化特征,并对上述因子进行了相关性分析.结果表明,近5年N/P值先增加后降低,5月和8月海水多为贫营养和磷限制中度营养,而10月多呈磷限制潜在性富营养;除2006年和2007年10月水质分别达到轻度和中度污染外,其他时期基本未受有机污染,四十里湾有机污染状况有向好趋势.浮游植物多样性指数年际变化显示,总体呈先降低后增加的趋势,与其数量变化趋势相反.相关性分析显示,有机污染指数A与无机磷(IP)浓度呈显著正相关(P＜0.01),与DIN相关不显著(P＞0.05),这说明IP是影响四十里湾有机污染水平的首要因素;浮游植物多样性指数与其数量呈负相关,而与Si/P和IP浓度分别呈正相关(P＞0.05),浮游植物多样性指数与Si/P和IP的Pearson相关系数分别达到0.446和0.413.IP是四十里湾海水营养状况、有机污染及浮游植物多样性的主要影响因子之一.     

西泉眼水库夏季浮游动物群落结构特征及水质评价

2010年夏季,对西泉眼水库浮游动物及水质理化指标进行了调查。分析了该水库浮游动物群落结构特征,运用现存量法、指示生物法、多样性分析法、Q_(B/T)指数法、E/O指数法、肥度指数法(E')和理化因子分析法评价了水质等级,应用典范对应法分析了浮游动物与环境因子之间的相关性。结果表明:浮游动物56种,优势种为褐砂壳虫Difflugia avellana、长三肢轮虫Filinia longiseta、针簇多肢轮虫Polyarthra trigla、微刺小剑水蚤Microcyclops inchoatus和无节幼体;污染指示种53种,丰度为46.13个/L,生物量为0.137mg/L;Shannon-Wiener指数为2.78,Margalef丰富度指数为1.97,Q_(B/T)指数为2.0,E/O指数为3.2,肥度指数(E')为2.28。评价结果表明,该水库已处于中度污染状态,水体处于中富营养化水平,NO_3~-、NO_3-N、Cl~-、COND、Depth、NH_4~+、TP和Chla是影响浮游动物种群数量及分布的主要环境因子,作为水源地其水质还需进一步加强管理与调控。     

瓯江干流丽水段水体富营养化评价

2009年3月、5月、8月、11月在全长41.7 Km的瓯江干流丽水段设10个站点,对DO、CODMn、NH3-N、TN、TP等5项水质指标进行了测定,并运用营养状态指数对水体水质进行了分析和评价。结果显示,2个站点水体水质达到地表水环境质量Ⅲ类标准,5个站点水体水质为Ⅳ类标准,3个站点为Ⅴ类标准。评价结果显示2009年全江段水体水质的营养水平全部为中营养水平。     

晋江流域水质污染与浮游动物四季群落结构的关系

报道了2003年2、4、6、8、10和12月在福建晋江流域15个样点进行浮游动物群落生态学调查研究的结果。采用种类组成、种群数量、优势种群、Margalef和Shannon-Wiener多样性指数等参数,初步比较了流域中各不同河段的水质状况,结果显示,流域受污染程度的顺序为东、西溪〈晋江干流〈南、北干渠。东溪、西溪上过度开发的梯级水电站对浮游动物群落结构和水质有明显的影响,加速了水体富营养化进程。     

广西刁江流域主要河流水质评价

为研究广西刁江水质污染现状, 从刁江流域上游到下游共设置 9 个水质监测断面。于 2013 年 12 月-2014 年 12月对河流的 pH、溶解氧、高锰酸盐指数、叶绿素 a、总氮、总磷、氨氮、硝酸盐氮、亚硝酸盐氮、正磷酸盐、重金属(砷、铅、镉、汞、铬)水质指标进行监测。采用单因子和综合污染指数对刁江水质进行评价, 同时开展水体富营养化评价。单因子污染指数评价结果表明刁江流域主要污染物为总氮和砷。综合污染指数评价结果表明刁江流域水质整体较好, 但上游的平村河污染较严重。从时间分布来看, 秋季水质最差, 冬季较好。从营养化状态指数来看, 平村河为中度富营养化状态, 其余河流为中营养状态, 富营养化程度呈现春夏高, 冬季低的特点。对评价结果进行主成分分析, 结果表明刁江流域总氮最大的贡献者可能来源于居民的生活污水。     

胶州湾湿地海域水体和表层沉积物环境质量评价

基于2009年对胶州湾湿地48个站点的调查数据,采用内梅罗(Nemerow)指数、富营养指数(EI)和Hakanson潜在生态危害指数法对胶州湾湿地水体和表层沉积物环境质量现状进行了评价.结果表明:对参与评价的pH值、溶解氧、无机氮、活性磷酸盐、CODMn、石油类、Cu、Zn、Pb、Cd、Hg、As、六六六、滴滴涕、大肠菌群、粪大肠菌群等16项指标而言,各调查月份大沽河感潮河段水质处于中污染-重污染水平,潮间带区域水质处于轻污染-中污染水平,浅海区域水质处于轻污染水平.胶州湾湿地不同区域富营养化程度差异明显,其中大沽河感潮河段水体EI值在58.13 ～327.89,富营养化程度严重;潮间带区域水体EI值在1.34 ～19.96,富营养化程度较为严重;浅海区域水体EI值在0.65 ～ 2.10,富营养化程度较轻.胶州湾湿地海域表层沉积物质量基本处于轻污染水平,其中大沽河感潮河段处于轻污染水平,潮间带区域处于轻污染-中污染水平,浅海区域处于较清洁-轻污染水平.胶州湾湿地海域表层沉积物中重金属单项污染参数(Cfi)和污染程度指数(Cd)较低,污染程度处于低级水平,Cu、Zn是表层沉积物中的主要污染因子;重金属潜在的生态危害系数(Eir)和潜在生态危害指数(RI)较小,污染程度属于低生态危害范畴.     

黄河口及邻近海域氮、磷及环境质量评价

根据2008年和2009年5、8月4个航次黄河口及邻近海域监测数据,分析了该海域氮磷含量和分布,与历史数据进行比较,分析年际动态变化、营养类型,并进行有机污染和营养状态评价。结果表明:整个黄河口及邻近海域氮营养水平较高,大部分海域磷酸盐营养水平较低,营养类型为磷限制潜在性富营养;整个监测海域处于中～富营养状态,春季(5月)富营养水平稍重于秋季(8月),河口近岸海域和南部海域富营养水平较重;2008年5月和2009年8月监测海域有机污染评价为开始受污染,2008年8月和2009年5月水质较好。     

福建南日群岛秋季海洋生态环境诊断与评价

根据2007年9月和10月福建南日岛生态调查资料,从海水水质、海水营养结构与营养水平、生物多样性等3个方面诊断与评价了南日群岛海域环境现状,利用综合质量指数法对海洋生态环境质量进行综合评价,并探讨了不同评价指数的关系及合理性.结果表明:海域的pH、溶解氧(DO)、化学需氧量(COD)、Pb、Cd、Hg、As含量均符合第二类海水水质标准.71%站位的磷酸盐、14%站位的无机氮和7%站位的石油类污染物超第二类海水水质标准.海水水质总体属于较好等级,营养结构表现为氮限制,大部分海域处于富营养化状态,依据浮游生物的多样性指数评价结果为轻污染-清洁水平.生态环境综合质量指数评价结果表明南日群岛海域生态环境总体处于良好水平.利用不同的评价指数对海域环境健康状况进行诊断的结果存在一定差异.在实际评价中应综合运用化学指标和生物指标,才能得到相对客观的结论.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.