潮汐对江水致突变性的影响

对某潮汐河流从下游至上游共设A、B、C、D、E五个采样点,用Ames试验、双微核试验及单细胞凝胶电泳试验(彗星试验)检测涨潮和落潮时江水中有机污染物的致突变性.结果表明,Ames试验各采样点样品都有致突变性,且从上游至下游逐渐增强;对TA98加S9致突变性增加;双微核试验、彗星试验检测出染色体及DNA损伤剂,并以A点作用最强.涨潮时各点致突变强度较落潮时强.     

硅胶分离-气相色谱法测定海水样品中的有机氯农药及多氯联苯

建立了硅胶净化-具电子捕获检测器气相色谱(GC-ECD)测定海水样品中有机氯农药(OCPs)、多氯联苯(PCBs)的方法。海水样品经正己烷萃取,浓缩萃取液后过硅胶层析柱,通过梯度淋洗进行样品的净化和分离,采用GC-ECD进行分析测试。OCPs回收率达70.7%~109.2%,PCBs回收率达92.6%~119.2%。采用GC-MS进行辅助确证,结果表明,方法可行。     

水样中常见金属离子的快速测定

研究了用高效毛细管电泳对自来水水样中常见金属离子的快速测定方法。结果表明,K+、Na+、Li+、Ca2+、Mg2+、Ba2+、Sr2+7种离子在8 min内可全部分离,回收率为98.0%~103.3%。峰面积和迁移时间的相对标准偏差分别在3.2%和1.1%以下,重现性较好,具有较高的检测灵敏度。     

凝胶层析-荧光分光光度法联用分析饮用水中铝的形态

将凝胶层析与荧光分光光度法相结合进行饮用水中铝形态的分析.结果表明,凝胶层析对胶体态铝和溶解态铝有较好的分离效果.依据衍生试剂8-羟基喹啉(8-HQ)和铬蓝黑R(EBBR)与不同铝形态结合强度的差异,通过荧光分光光度法可分析饮用水中的单核铝、无机单核铝,再结合硝酸消解可测定饮用水中的总铝、溶胶态铝和胶体态铝.对饮用水中铝形态的分析表明:清华大学地区的地下水和北京市给水管网末端水的总铝含量均在50μg·l-1以下,无机单核铝为饮用水中铝的主要存在形态.     

Effect of Dursban 480 EC (chlorpyrifos) and Talstar 10 EC (bifenthrin) on the physiological and genetic diversity of microorganisms in soil

This investigation was undertaken to determine the impact of the insecticides Dursban 480 EC (with organophosphate compound chlorpyrifos as the active ingredient) and Talstar 10 EC (with pyrethroid bifenthrin as the active ingredient) on the respiration activity and microbial diversity in a sandy loam luvisol soil. The insecticides were applied in two doses: the maximum recommended dose for field application (15 mg kg^?1 for Dursban 480 EC and 6 mg kg^?1 for Talstar 10 EC) and a 100-fold higher dose for extrapolation of their effect. Bacterial and fungal genetic diversity was analysed in soil samples using PCR DGGE and the functional diversity (catabolic potential) was studied using BIOLOG EcoPlates at 1, 3, 7, 14, 28, 56 and 112 days after insecticide application. Five bacterial groups (α, β, γ proteobacteria, firmibacteria and actinomycetes) and five groups of fungi or fungus-like microorganisms (Ascomycota, Basidiomycota, Chytridiomycota, Oomycota and Zygomycota) were analysed using specific primer sets. This approach provides high resolution of the analysis covering majority of microorganisms in the soil. Only the high-dose Dursban 480 EC significantly changed the community of microorganisms. We observed its negative effect on α- and γ-proteobacteria, as the number of OTUs (operational taxonomic units) decreased until the end of incubation. In the β-proteobacteria group, initial increase of OTUs was followed by strong decrease. Diversity in the firmibacteria, actinomycetes and Zygomycota groups was minimally disturbed by the insecticide application. Dursban 480 EC, however, both positively and negatively affected certain species. Among negatively affected species Sphingomonas, Flavobacterium or Penicillium were detected, but Achromobacter, Luteibacter or Aspergillus were supported by applied insecticide. The analysis of BIOLOG plates using AWCD values indicated a significant increase in metabolic potential of microorganisms in the soil after the high-dose Dursban application. Analysis of respiration demonstrated high microbial activity after insecticide treatments; thus, microbial degradation was relatively fast. The half-life of the active insecticide compounds were estimated within the range of 25 to 27 days for Talstar and 6 to 11 days for Dursban and higher doses stimulated degradation. The recommended dose levels of both insecticides can be considered as safe for microbial community in the soil.     

胶束电动毛细管色谱法测定水中的毒死蜱含量

利用胶束电动毛细管色谱（MEKC）建立了测定水中毒死蜱含量的方法,研究了检测波长、运行缓冲液的种类、浓度以及pH、有机添加剂、脱氧胆酸钠（NaDCh）的浓度和分离电压等实验条件对毒死蜱测定的影响.实验结果表明,以25 mmol.L-1硼砂（pH 9.0,含20%（V/V）乙腈和50 mmol.L-1NaDCh）作为缓冲...     

Are Swiss birds tracking climate change?: Detecting elevational shifts using response curve shapes

Climate change is affecting biodiversity worldwide inducing species to either “move, adapt or die”. In this paper we propose a conceptual framework for analysing range shifts, namely a catalogue of the possible patterns of change in the distribution of a species along elevational or other environmental gradients and an improved quantitative methodology to identify and objectively describe these patterns. Patterns are defined in terms of changes occurring at the leading, trailing or both edges of the distribution: (a) leading edge expansion, (b) trailing edge retraction, (c) range expansion, (d) optimum shift, (e) expansion, (f) retraction, and (g) shift. The methodology is based on the modelling of species distributions along a gradient using generalized additive models (GAMs). Separate models are calibrated for two distinct periods of assessment and response curves are compared over five reference points. Changes occurred at these points are formalized into a code that ultimately designates the corresponding change pattern. We tested the proposed methodology using data from the Swiss national common breeding bird survey. The elevational distributions of 95 bird species were modelled for the periods 1999-2002 and 2004-2007 and significant upward shifts (all patterns confounded) were identified for 35% of the species. Over the same period, an increase in mean temperature was registered for Switzerland. In consideration of the short period covered by the case study, assessed change patterns are considered to correspond to intermediate patterns in an ongoing shifting process. However, similar patterns can be determined by habitat barriers, land use/land cover changes, competition with concurrent or invasive species or different warming rates at different elevations.     

秦皇岛近海养殖对潮间带微生物群落多样性的影响

潮间带微生物群落在驱动海岸带生态系统物质循环和能量流动中具有重要作用,近海养殖造成的环境问题日益凸显,但其对潮间带微生物群落结构的影响还缺乏研究。采用变性梯度凝胶电泳（DGGE）和限制性片段长度多态性（RFLP）的分子生物学技术,研究秦皇岛养殖区与旅游区潮间带沉积物中微生物多样性的差异,分析养殖区微生物的16S rRNA基因文库的组成特征。结果表明：养殖区的微生物群落结构与旅游区形成较大的差异,DGGE图谱中养殖区的特有条带主要集中于γ-变形菌纲（γ-proteobacteria）,还分布于α-变形菌纲（α-proteobacteria）,拟杆菌门（Bacteroidetes）,放线菌门（Actinobacteria）和厚壁菌门（Firmicutes）。影响潮间带微生物的群落结构的主要环境因子包括温度、盐度、pH和NO3-浓度,影响率达55.2%。对差异最大的洋河大桥南养殖区（Q1站）的微生物样品建立克隆文库分析群落结构,变形菌门（Proteobacteria）为优势菌群,占总群落的60%,其中γ-变形菌纲是主要存在的微生物纲,其余菌群包括放线菌门、拟杆菌门、蓝藻菌门（Cyanobacteria）和疣微菌门（Verrucomicrobia）的微生物。养殖区海岸带微生物群落中出现了与环境污染和赤潮密切相关的菌群,如拟杆菌门、肠杆菌属（Enterobacteriaceae）和α-变形细菌红细菌目（Roseovarius）的微生物。     

元谋干热河谷植物功能性状组合的海拔梯度响应

植物功能性状能够显示对环境变化的响应,不同的适应对策呈现出不同的功能性状组合。干热河谷地区水分是最主要的限制性环境因子,之前的大部分研究都是集中关注于干热河谷局部地段,对于从垂直海拔上来研究不同植物在环境梯度下的变化的研究较少。干热河谷地区由于梵风效应,水分胁迫沿海拔梯度发生变化,一般表现为随海拔高度升高,气温降低,湿度和降水量增加,而蒸发量减小,辐射增强。以云南元谋干热河谷4个海拔梯度（1491.33、1730.20、1850.00、1925.57 m）中的植物为研究对象,选取叶片干物质含量（LDMC）、叶面积（LA）、比叶面积（SLA）、叶片厚度（LT）和叶密度（LD）5个功能性状,研究它们的相互关系,比较了海拔间的差异。结果表明：1）5个功能性状在不同海拔间均呈现出一定差异,变异系数由高到低为LD>LA>SLA>LT>LDMC（分别是101%、64%、56%、41%和19%）;方差分析结果也表明,5个功能性状在不同海拔之间差异显著（F=56.218,P<0.01;F=7.829,P<0.01;F=11.21,P<0.01;F=7.429,P<0.01;F=19.213,P<0.01）,尤其是在最低（1491.33 mm）和最高（1927.57 mm）海拔之间,各性状均具有极显著的差异;2）性状之间存在组合关系, LD与其他性状间相关性最为明显,除LDMC以外,LD与LA、SLA、LT均呈现出极显著负相关关系;LDMC与LA和LT呈极显著负相关;SLA与LA和LT呈正相关,而与LDMC显著负相关;LT与SLA显著正相关,与LA之间相关性不显著;3）在不同的海拔梯度之间,性状组合存在非同步变化现象。研究显示,元谋干热河谷地区,植物对水分环境的海拔梯度变化产生功能性状组合的响应,低海拔和高海拔物种对所处环境的适应策略不同,使得植物在海拔梯度上出现叶片功能性状组合的分化和差异。