The OECD Validation Program of the H295R Steroidogenesis Assay for the Identification of In Vitro Inhibitors and Inducers of Testosterone and Estradiol Production. Phase 2: Inter-Laboratory Pre-Validation Studies (8 pp)

Background, Goals and Scope In response to concerns that have been raised about chemical substances that may alter the function of endocrine systems and result in adverse effects on human health, an OECD initiative was undertaken to develop and validate in vitro and in vivo assays to identify chemicals that may interfere with endocrine systems of vertebrates. Here we report on studies that were conducted to develop and standardize a cell-based screening assay using the H295R cell line to prioritize chemicals that may act on steroidogenic processes in humans and wildlife. These studies are currently ongoing as part of the ‘Special Activity on the Testing and Assessment of Endocrine Disruptors’ within the OECD Test Guidelines Program to review, develop, standardize, and validate a number of in vitro and in vivo toxicological assays for testing and assessment of chemicals concerning their potential to interact with the endocrine system of vertebrates. Study Design Six laboratories from five countries participated in the pre-validation studies. Each laboratory tested the effects of three model chemicals on the production of testosterone (T) and estradiol (E2) using the H295R Steroidogenesis Assay. Chemicals tested were well described inducers or inhibitors of steroidogenic pathways (forskolin, prochloraz and fadrozole). All experiments were conducted in 24 well plates following standard protocols. Six different doses per compound were analyzed in triplicate per plate. A quality control (QC) plate was run in conjunction with the chemical exposure plate to account for inter-assay variation. Each chemical exposure was conducted two or three times. Results All laboratories successfully detected increases and/or decreases in hormone production by H295R cells after exposure to the different model compounds and there was good agreement in the pattern of response for all groups. Forskolin increased both T and E2 while fadrozole and prochloraz decreased production of both hormones. All chemicals affected hormone production in a dose-dependent manner with the exception of fadrozole which caused maximum inhibition of E2 at the two least concentrations tested. Some inter-laboratory differences were noted in the alteration of hormone production measured in chemically exposed cells. However, with the exception of the production of T measured at one laboratory in cells exposed to forskolin, the EC₅₀s calculated were comparable (coefficients of variation 34–49%) for all hormones. Discussion and Perspectives The results indicated that the H295R Steroidogenesis Assay protocol was robust, transferable and reproducible among all laboratories. However, in several instances that were primarily related to one laboratory there were unexplained minor uncertainties related to the inter-laboratory hormone production variation. Based on the findings from this Phase 2 prevalidation study, the H295R Steroidogenesis Assay protocol is currently being refined. The next phase of the OECD validation program will test the refined protocol among the same group of laboratories using an extended set of chemicals (∼30) that will include positive and negative chemical controls as well as a broad spectrum of different potential inducers and inhibitors of steroidogenic pathways. Submission Editor: Dr. Carsten Brühl (bruehl@uni-landau.de)     

Bayesian entropy for spatial sampling design of environmental data

We develop a spatial statistical methodology to design national air pollution monitoring networks with good predictive capabilities while minimizing the cost of monitoring. The underlying complexity of atmospheric processes and the urgent need to give credible assessments of environmental risk create problems requiring new statistical methodologies to meet these challenges. In this work, we present a new method of ranking various subnetworks taking both the environmental cost and the statistical information into account. A Bayesian algorithm is introduced to obtain an optimal subnetwork using an entropy framework. The final network and accuracy of the spatial predictions is heavily dependent on the underlying model of spatial correlation. Usually the simplifying assumption of stationarity, in the sense that the spatial dependency structure does not change location, is made for spatial prediction. However, it is not uncommon to find spatial data that show strong signs of nonstationary behavior. We build upon an existing approach that creates a nonstationary covariance by a mixture of a family of stationary processes, and we propose a Bayesian method of estimating the associated parameters using the technique of Reversible Jump Markov Chain Monte Carlo. We apply these methods for spatial prediction and network design to ambient ozone data from a monitoring network in the eastern US.     

一株白腐菌产生的漆酶对RB亮蓝的脱色作用

W 1是一株能在液体条件下产漆酶的白腐菌 ,纯化的漆酶对RB亮蓝有很好的脱色作用 .漆酶的最适脱色温度为 4 5℃ ,最适脱色pH值为 6 .0 ,脱色pH范围在 4～ 7之间 .当溶液中漆酶活力为 2 .0× 10 3 U/L时 ,在最适脱色条件下、16h内 ,RB亮蓝 (30 0mg/L)的脱色率可以达到 90 % .经酶作用后 ,RB亮蓝在 4 30～ 70 0nm范围内的特征颜色吸收峰基本消失 .实验证明 ,在相同的条件下 ,漆酶粗酶对RB亮蓝有更好的脱色效果 .图 7表 1参 6     

Vertical profiles of biogenic volatile organic compounds as observed online at a tower in Beijing

Vertical profiles of isoprene and monoterpenes were measured by a proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS) at heights of 3, 15, 32, 64, and 102 m above the ground on the Institute of Atmospheric Physics (IAP) tower in central Beijing during the winter of 2016 and the summer of 2017. Isoprene mixing ratios were larger in summer due to much stronger local emissions whereas monoterpenes were lower in summer due largely to their consumption by much higher levels of ozone. Isoprene mixing ratios were the highest at the 32 m in summer (1.64 ± 0.66 ppbV) and at 15 m in winter (1.41 ± 0.64 ppbV) with decreasing concentrations to the ground and to the 102 m, indicating emission from the tree canopy of the surrounding parks. Monoterpene mixing ratios were the highest at the 3 m height in both the winter (0.71 ± 0.42 ppbV) and summer (0.16 ± 0.10 ppbV) with a gradual decreasing trend to 102 m, indicting an emission from near the ground level. The lowest isoprene and monoterpene mixing ratios all occurred at 102 m, which were 0.71 ± 0.42 ppbV (winter) and 1.35 ± 0.51 ppbV (summer) for isoprene, and 0.42 ± 0.22 ppbV (winter) and 0.07 ± 0.06 ppbV (summer) for monoterpenes. Isoprene in the summer and monoterpenes in the winter, as observed at the five heights, showed significant mutual correlations. In the winter monoterpenes were positively correlated with combustion tracers CO and acetonitrile at 3 m, suggesting possible anthropogenic sources.     

Simultaneous removal and oxidation of arsenic from water by δ-MnO2 modified activated carbon

The ubiquitous arsenic in groundwater poses a great risk to human health due to its environmental toxicity and carcinogenicity. In the present work, a new adsorbent, δ-MnO₂ modified activated carbon, was prepared, and its performance for the uptake of arsenate and arsenite species from aqueous solutions was investigated by batch experiments. Various techniques, including FESEM-EDX, p-XRD, XPS and BET surface area analysis, were employed to characterize the properties of the adsorbent and the arsenic adsorption mechanisms. The results showed that δ-MnO₂ covered on the surface and padded in the pores of the activated carbon. Adsorption kinetic studies revealed that approximately 90.1% and 76.8% of As(III) and As(V), respectively, were removed by the adsorbent in the first 9 hr, and adsorption achieved equilibrium within 48 hr. The maximum adsorption capacities of As(V) and As(III) at pH 4.0 calculated from Langmuir adsorption isotherms were 13.30 and 12.56 mg/g, respectively. The effect of pH on As(V) and As(III) removal was similar, and the removal efficiency significantly reduced with the increase of solution pH. Arsenite oxidation and adsorption kinetics showed that the As(V) concentration in solution due to As(III) oxidation and reductive dissolution of MnO₂ increased rapidly during the first 12 min, and then gradually decreased. Based on the XPS analysis, nearly 93.3% of As(III) had been oxidized to As(V) on the adsorbent surface and around 38.9% of Mn(IV) had been reduced to Mn(II) after As(III) adsorption. This approach provides a possible method for the purification of arsenic-contaminated groundwater.     

长江经济带国家重点生态功能区生态补偿环境效率评价

环境效率是考量生态补偿政策实施效果的重要指标,对国家重点生态功能区生态补偿环境效率进行有效测度可以为完善我国生态补偿政策提供有益参考.采用三阶段DEA模型对长江经济带11个省市的国家重点生态功能区生态补偿环境效率水平、变化趋势及其差异性进行评价,通过线性数据转化方法对非期望环境负产出进行处理,并识别第三产业增加值占比等背景变量对投入产出效率的影响.结果表明:①长江经济带第三产业增加值占比对能源投入产出的影响显著（t值检验达到5%显著性水平）,进出口总额、人均GDP、人口密度等因素对各项投入产出的影响均不显著.②长江经济带11个省市2012-2017年综合技术效率均值在剔除背景因素和随机干扰前后未发生变化,但纯技术效率均值由调整前的0.94升至调整后的0.96,规模效率均值由调整前的0.94降至0.92,表明纯技术效率对提高环境效率起主导作用.③上游4个省市（重庆市、四川省、云南省、贵州省）与中下游7个省市（江西省、湖南省、湖北省、安徽省、江苏省、浙江省、上海市）生态补偿环境效率均值差距较大,其中,云南省的环境效率最低.研究显示,长江经济带11个省市的国家重点生态功能区生态补偿环境效率从上游到下游整体呈上升趋势,应在提高综合技术效率的同时,更加注重基本公共服务能力和生态环境保护双重目标的协调.      

一种基于Stella和R语言的湿地氮素动力学模型

通过Stella软件的可视化建模环境,快速开发构建了一种适用于表流型人工湿地的氮素循环动力学模型,并将模型翻译成R语言,可实现编程计算、数据分析及空间分析等多种算法和功能与动力学模型的集成,能大大提高模型的分析和预测能力,加强模型的实用性和应用能力.以大沙河人工湿地氨氮污染负荷最大削减能力为例,本文基于此模型,集成R语言强大的编程和计算能力,建立了进水水质与水量的调度函数关系,并确定了人工湿地最优进水水量、水质和污染负荷最大削减能力.     

重金属防控区域整治进展及“十三五”思路研究

文章总结性提出我国138个防控区域"十二五"期间实践的3种类型防控模式,对防控区域总体成效和经验进行了阐述,分析了当前防控区域深入推进过程中面临的主要问题,并从导向管理、目标管理、监控管理等方面,提出了"十三五"防控区域深入管理4个方面的建议。     

Developing inventory and monitoring programs based on multiple objectives

Resource inventory and monitoring (I&M) programs in national parks combine multiple objectives in order to create a plan of action over a finite time horizon. Because all program activities are constrained by time and money, it is critical to plan I&M activities that make the best use of available agency resources. However, multiple objectives complicate a relatively straightforward allocation process. The analytic hierarchy process (AHP) offers a structure for multiobjective decision making so that decision-makers’ preferences can be formally incorporated in seeking potential solutions. Within the AHP, inventory and monitoring program objectives and decision criteria are organized into a hierarchy. Pairwise comparisons among decision elements at any level of the hierarchy provide a ratio scale ranking of those elements. The resulting priority values for all projects are used as each project’s contribution to the value of an overall I&M program. These priorities, along with budget and personnel constraints, are formulated as a zero/one integer programming problem that can be solved to select those projects that produce the best program. An extensive example illustrates how this approach is being applied to I&M projects in national parks in the Pacific Northwest region of the United States. The proposed planning process provides an analytical framework for multicriteria decisionmaking that is rational, consistent, explicit, and defensible.     

由洪水泛滥的教训谈国家统一灾害管理

本文系统分析和总结了美国在洪泛平原管理中的经验教训，研究了减灾措施、行为反应及国家长期减灾目标等方面的内容，从综合的角度提出了统一的国家减灾计划。