Effects of modified Pb-, Zn-, and Cd- availability on the microbial communities and on the degradation of isoproturon in a heavy metal contaminated soil

The effects of modified heavy metal (HM) availability on the microbial community structure and on the microbe-mediated degradation of herbicide isoproturon (IPU) were evaluated in soil with a long-term HM contamination. The fate of ¹⁴C-ring labelled IPU was investigated for over 60 days under controlled microcosm conditions. Phosphate mineral apatite and a water solution of Pb, Zn, and Cd salts were previously homogeneously mixed into the soil material to reduce and to increase the proportion of bioavailable HM, respectively. The availability of Pb, Zn, and Cd was determined by HM fractionation and plant uptake 110 days after the addition of amendments, shortly before IPU addition. Apatite treatment reduced the availability of HM, but did not affect the microbial biomass and the microbial community structure on the genotype level (total soil DNA-RAPD). However, it changed the microbial community structure on the phenotype level, based on the composition of phospholipid fatty acids (PLFA) at the end of the degradation experiment. The degradation of IPU did not change. In contrast to apatite treatment, HM supplementation increased the bioavailability of Pb, Zn and Cd, which resulted in biomass reduction and changes of microbial community structure on the genotypic (total soil DNA-RAPD) and phenotypic (PLFA) level. Increased bioavailability of HM also significantly reduced the rate of IPU degradation and mineralisation. The total mineralisation over a period of 60 days decreased from 12 to 5% of initial ¹⁴C. Increased HM bioavailability did not influence the degradation pathways and kinetics of IPU.     

多目标土地利用总体规划方法研究

土地资源是人类赖以生存的基础，是最基本的生产资料，其可持续利用是实现社会可持续发展的基础。为了促进土地资源可持续利用，提出多目标土地利用总体规划，并对其实现方法进行研究。多目标土地利用总体规划的方法由以下框架构成：土地资源数据库建立，土地多宜性评价，土地利用方式多目标优化，土地利用系统生态设计和土地利用布局。并以徐水县为例，用多目标线性规划模型优化用地结构，提出了三个规划方案，通过分析和比较，最终选择方案2为满意和推荐方案，并用生态学原理和土地多宜性评价结果对方案2所确定的土地利用方式进行整体空间布局，最终完成徐水县土地利用总体规划。     

Application of para-nitrophenol (pNP) enzyme assays in degraded tropical soils

Enzyme activities have been used as indicators of soil quality and changes in biogeochemical function due to management or perturbations. The objective of this study was to answer a number of methodological questions regarding sampling schemes, sample handling recommendations, and assay procedures to facilitate the use of enzyme assays in the tropical highlands of East Africa. We used para-nitrophenol (pNP) based substrates for five enzymes: β-glucosidase, cellobiohydrolase, chitinase, acid phosphatase, and alkaline phosphatase. In the first experiment, we examined sampling procedures and compared the results of determining enzyme activities on a plot using composite or discrete samples. Composite samples usually had higher activities than the means of individual cores (P<0.05), but relative ranking of sites was the same if analyses were based on composite or discrete samples. In the second experiment, we examined the effects of storage time and conditions on enzyme activity. Enzyme activity degraded rapidly in frozen samples, but was better maintained in samples stored at 4 °C. Phosphatase and cellobiohydrolase activity declined after 14 days of storage, while the activity of the other enzymes remained close to the values of fresh samples for 28 or more days. In the third experiment, we examined the effect of the addition of an antiseptic, toluene, to prevent bacterial growth during the assay. We found no consistent toluene effect (P>0.4), probably because the assays were of short duration and microbial growth was minimized. Finally, we looked at the incubation time necessary to produce reliable results. Phosphatases, with relatively high activities could reliably be determined in 2 h incubations, but the other enzymes had much lower activities and required longer incubation times for reliable determination. For the enzymes we looked at, 4 h was a good standard time for determining the activity of even the lowest activity enzymes. The results of this study provide practical guidelines for applying these enzyme assays in the degraded tropical soils.     

Effects of tetracycline on the soil microflora: function,diversity, resistance

Background  Tetracycline is a widely used antibiotic in animal production. Significant amounts of the substance reach the soil via feces, urine and manure application. As tetracycline is a persistent compound with antibacterial activity, its presence in soil may have undesired direct and indirect effects. These have been investigated so far focusing on effects on selected microbial functions. Objectives  The aim of the present study was to obtain comprehensive information on potential effects of tetracycline on the soil microflora under environmentally relevant conditions. The investigations included function and structure of the microbial biocoenosis and the distribution of resistance genes. Methods  Pig manure rich in tetracycline resistance genes was applied to a sandy soil. This soil as well as an unamended soil were additionally treated with several concentrations of tetracycline. The spiked soils were incubated in outdoor lysimeters for several months. Substrate induced respiration, PLFAs, ten selected resistance genes, and the concentrations of tetracycline were determined. Results  The test concentrations, though far exceeding environmental relevance, caused only small effects. An establishment of resistance could not be detected. Applied resistance genes were not detectable at the end of the study even in the presence of added tetracycline. Conclusion  Due to the high sorption capacity of the antibiotic, environmentally relevant concentrations of tetracycline do not seem to cause undesired effects on the soil microflora.     

The Application of Multivariate Statistical Methods for the Evaluation of Soil Profiles (8 pp)

Background, Aim and Scope   Contamination of soils does not only occur on their surface over large areas, but also in depth. Therefore a characterization of soil state after pollution demands a three-dimensional soil sampling, by what a large number of samples has to be analyzed. Analytical results could be evaluated by multivariate statistical methods, which have already been used for the evaluation of data sets containing results from soil sampling of two dimensions like areas or single profiles. In this case study, multivariate statistical methods were applied to investigate structure and interactions between features in a data set containing results of three-dimensional soil sampling. The investigated soil profiles were contaminated by emissions of a former cement and phosphate fertilizer plant. The aim of this study was to determine the remaining extent of contamination and to analyze whether pollutants are mobilized and vertically transported within the profiles. Materials and Methods: Three soil profiles were sampled in the surroundings of the plant. Grain size, organic and carbonatic bonded carbon, pH value, and the total contents of Ca, Cd, Co, Cu, F, Fe, K, Mn, Mg, Na, Ni, P, Pb, and Zn were determined. The resulting data set was evaluated by cluster analysis, linear discriminant analysis, and principal components analysis. The sequential extraction procedure according to Zeien and Brümmer was applied to analyze the binding properties of Ca, Cd, Cu, Na, Pb, and Zn from selected samples. Results: Cd was identified as contaminant of the top soils. The pH values of the bottom soils were determined to be in alkaline range, which is unnaturally high. Variables were clustered according to enrichment of variables in top soils. The samples were classified regarding their pollution state and their substrate by cluster analysis, which was confirmed by linear discriminant analysis. Geogenic and anthropogenic sources of variables as well as relationships between variables like the binding of heavy metals at organic matter were detected by using principal components analysis. The binding of heavy metals at organic matter in the top soils was confirmed by the results of the applied sequential extraction. A vertically altered distribution of Na binding was determined. Discussion: According to the current soil conditions, the uptake of heavy metals had probably occurred by the over ground part of plants during the deposition. The distribution of Na should likely result from the vertical transport of Na, which would also explain the high pH values of the bottom soils by ion exchange. Altogether, the main amount of deposited Ca, F, Na, P, and heavy metals is likely nearly insoluble bound in the top soils. Conclusions: Ten years after the end of production, the pollution of top soils in the surroundings of the former plant is still high. However, regarding the ecotoxicological relevance the now explored interactions between several soil features and elements strongly indicate that there is no short-term to medium-term risk of a mobilization of the deposited elements with the exception of Na. Recommendations and Perspectives: The results of this case study prove that multivariate statistical methods are powerful tools to explore interactions of variables and relationships in a data set derived from three dimensional soil sampling. The methods applied in this work can be highly recommended for evaluations of large data sets resulting from two- or three-dimensional samplings. Multivariate statistical methods enable the characterization of soils and their pollution state in a simple and economic way.     

除草剂施田补对沼水蛙血细胞和心肌收缩能力的影响

以沼水蛙(Hylarana guentheri)为研究对象,研究了不同剂量的施田补溶液对沼水蛙的急性毒性效应及其外周血红细胞数/白细胞数、红细胞微核率、红细胞核异常率和总核异常率等的影响,同时利用Powerlab生物信号采集系统研究了施田补对沼水蛙心肌收缩能力的影响。结果显示,施田补对沼水蛙的96 h半致死剂量、安全剂量分别为1.149 9 m L/L和0.115 0 m L/L。所有药物组(0.012 5~0.400 0 m L/L)沼水蛙的血红细胞微核率、核异常率、总核异常率等均高于对照组,而且大部分药物组与清水对照组差异显著或极显著。在较高剂量(≥0.050 0 m L/L)中处理较长时间(192 h)时差异更加明显。所有药物组的外周血白细胞数/红细胞数与对照组相比差异均极显著。施田补对沼水蛙心肌收缩功能具有一定的毒害作用。综上,施田补对沼水蛙具有较大的毒害作用。     

MicroRNA数字特征综述

阐述MicroRNA（miRNA）数字特征在计算识别中的发展及应用,总结相关数字特征在miRNA基因及靶基因预测中的作用。miRNA数字特征是计算识别物种新miRNA基因的工具,从首个miRNA基因被发现以来,数字特征研究由最初的miRNA序列特征和二级结构特征到现在常用的热力学特征、熵特征和拓扑特征等,均被广泛应用于新miRNA基因鉴别和靶基因辨识。随着新一代测序技术广泛应用,miRNA数字特征在miRNA生源论探讨、基因和靶基因识别、生物合成途径发掘等研究中具有重要作用。文章提出将数字特征应用于靶基因功能的归属判别、生物进化等研究领域,为miRNA数字特征在其他研究领域应用提供参考和借鉴。     

茉莉花茶和复方茶防止小鼠急性肾衰竭的研究

茉莉花茶、中药和复方茶对急性肾衰竭小鼠的生化及免疫功能试验结果表明，２．５％花茶、２．５％复方茶和０．３％的中药均能明显降低急性肾衰竭小鼠血清中分子物质（ＭＭＳ）含量。２．５％复方茶能显著降低肾衰竭小鼠血清尿素氮含量，而花茶和单纯中药的作用不明显。花茶、中药、复方茶均可显著促进小鼠脾Ｔ、Ｂ淋巴细胞增殖反应，而且都能增强小鼠脾淋巴细胞ＩＬ－２、ＩＬ－３的活性。文中还对花茶和复方茶保护肾功能的机理进行了讨论。     

中草药添加剂对育肥猪免疫功能的影响

[目的]研究中草药添加剂饲喂育肥猪(巴克夏×梅山猪)免疫功能的影响。[方法]选取48头体重40 kg健康巴梅猪随机分为对照组和3个试验组。分别采集30、60和90 d血样,检测血清中总蛋白、白蛋白、免疫球蛋白Ig G、Ig M和补体C3水平。屠宰后对免疫器官进行病理组织学检查,并进行组织切片观察。[结果]添加中草药试验组和对照组在总蛋白水平上差异不显著;试验Ⅰ组白蛋白水平在第30天显著高于对照组(P0.05);试验Ⅱ组血清中Ig G水平在第30天显著高于对照组(P0.05);Ⅱ组血清中Ig M水平在第60天显著低于对照组(P0.05),90 d极显著低于对照组(P0.01);C3补体试验组在第30天水平均显著高于对照组(P0.05)。屠宰组织器官观察和组织学切片观察均无明显差异。[结论]中草药饲料添加剂能够促进育肥猪的免疫功能。     

吉林省湿地资源价值组成分析

湿地是自然界最富有生物多样性和生态功能最高的生态系统,吉林省湿地生态系统在调节气候、涵养水源、蓄洪防旱、净化水质、保护生物多样性等方面有十分重要的环境功能和生态效益,在促进区域经济发展和维护生态平衡中发挥着重要的作用.然而,随着人口和经济发展压力的增长,湿地面积丧失及生态功能减退的风险加剧,湿地保护与管理面临严峻挑战.为了客观、全面地评价湿地生态系统在吉林省经济发展和生态环境保护中的地位和作用,该研究结合吉林省湿地的特点和质量状况,分析吉林省湿地生态系统服务功能的价值组成,为政府和有管部门湿地保护与管理提供依据.