Development and Evaluation of a Multiplexed Real-Time TaqMan RT-PCR Assay with a Sample Process Control for Detection of F-specific RNA Coliphage Genogroups I and IV

There are increasing concerns of zoonotic transmission of some animal enteric viruses, such as calicivirus, hepatitis E virus, and rotavirus, which are closely related to human pathogenic strains. Most enteric viruses are detected by molecular techniques because they cannot be cultured. Surrogates such as F-RNA coliphages are cultivable but few molecular methods exist. Individual real-time TaqMan RT-PCR assays for the replicase gene of F-RNA coliphage genogroups I and IV were developed and multiplexed with a real-time TaqMan RT-PCR assay for feline calicivirus as a sample process control for the simultaneous detection and enumeration of genogroup I and IV F-RNA coliphages. Genogroup IV were successfully detected with the multiplexed assay in 80% of fecal samples that contained F-RNA coliphage levels ≥3.2 log plaque forming units (pfu). F-RNA coliphage were at or below the limit of detection in most fecal samples when levels were ≤4 log pfu/g.     

环境水样前处理技术的探讨

环境水样前处理对监测结果准确度的影响不容忽视,是保证监测结果准确度的一个重要环节,样品前处理技术方法及需要注意的问题是保证监测结果真正可靠的保障。     

天然有机物的相对分子质量分布及亲疏水性对微滤膜组合工艺中膜污染的影响

研究采用混凝沉淀+粉末活性炭吸附+高锰酸钾+浸没式微滤膜的组合工艺对太湖水进行中试试验,通过高效凝胶色谱(HPSEC-UV-TOC)和三维荧光(3DEEM)的测定方法,着重考察有机物的相对分子质量(Mr)分布和亲疏水性对膜不可逆污染的影响.凝胶色谱分析表明:预处理可几乎完全去除大分子有机物(Mr>10×103),但仅能去除部分的中等分子(10×103>Mr>1×103)和小分子(Mr<1×103)有机物.研究发现化学清洗水中的有机物相对分子质量多为中等分子和小分子,说明导致膜不可逆污染的主要是中等分子和小分子有机物.此外,洗膜水中强疏和中性亲水组分含量远高于弱疏和极性亲水,说明强疏和中性亲水组分是不可逆污染的主要物质.三维荧光分析表明,芳香族蛋白质和溶解性微生物产物是造成膜不可逆污染的主要污染物.     

吡啶的气相色谱分析

试验了以气相色谱法、大口径弹性石英毛细管柱分离 ,NPD检测环境样品中吡啶 ,得到了良好的分离效果 ,峰形好 ,并有较高的灵敏度和较宽的线性范围 ,检测限可达 0 0 0 4mg/L ,完全能满足环境空气质量分析和水质分析的要求。     

NABat: A top-down,bottom-up solution to collaborative continental-scale monitoring

Collaborative monitoring over broad scales and levels of ecological organization can inform conservation efforts necessary to address the contemporary biodiversity crisis. An important challenge to collaborative monitoring is motivating local engagement with enough buy-in from stakeholders while providing adequate top-down direction for scientific rigor, quality control, and coordination. Collaborative monitoring must reconcile this inherent tension between top-down control and bottom-up engagement. Highly mobile and cryptic taxa, such as bats, present a particularly acute challenge. Given their scale of movement, complex life histories, and rapidly expanding threats, understanding population trends of bats requires coordinated broad-scale collaborative monitoring. The North American Bat Monitoring Program (NABat) reconciles top-down, bottom-up tension with a hierarchical master sample survey design, integrated data analysis, dynamic data curation, regional monitoring hubs, and knowledge delivery through web-based infrastructure. NABat supports collaborative monitoring across spatial and organizational scales and the full annual lifecycle of bats.     

Sampling and Mapping a Soil Erosion Cover Factor by Integrating Stratification,Model Updating and Cokriging with Images

Cost-efficient sample designs for collection of ground data and accurate mapping of variables are required to monitor natural resources and environmental and ecological systems. In this study, a sample design and mapping method was developed by integrating stratification, model updating, and cokriging with Landsat Thematic Mapper (TM) imagery. This method is based on the spatial autocorrelation of variables and the spatial cross-correlation among them. It can lead to sample designs with variable grid spacing, where sampling distances between plots vary depending on spatial variability of the variables from location to location. This has potential cost-efficiencies in terms of sample design and mapping. This method is also applicable for mapping in the case in which no ground data can be collected in some parts of a study area because of the high cost. The method was validated in a case study in which a ground and vegetation cover factor was sampled and mapped for monitoring soil erosion. The results showed that when the sample obtained with three strata using the developed method was used for sampling and mapping the cover factor, the sampling cost was greatly decreased, although the error of the map was slightly increased compared to that without stratification; that is, the sample cost-efficiency quantified by the product of cost and error was greatly increased. The increase of cost-efficiency was more obvious when the cover factor values of the plots within the no-significant-change stratum were updated by a model developed using the previous observations instead of remeasuring them in the field.     

Entrainment mortality of Ichthyoplankton: Detectability and precision of estimates

The ability to detect and to develop a precise and accurate estimate of the entrainment mortality fraction is an important step in projecting power plant impacts on future fish population levels. Recent work indicates that these mortailities may be considerably less than 100% for some fish species in the early life stages. Point estimates of the entrainment mortality fraction have been developed based on probabilistic arguments, but the precision of these estimates has not been studied beyond the simple statistical test of the null hypothesis that no entrainment mortaility exists.The ability to detect entrainment mortality is explored as a function of the sample sizes (numbers of organisms collected) at the intake and discharge sampling stations of a power plant and of the proportion of organisms found alive in the intake samples (intake survival). Minimum detectable entrainment mortality, confidence interval width, and type II error (probability of accepting the null hypothesis of no entrainment mortality when there is mortality) are considered. Increasing sample size and/or decreasing sampling mortality will decrease the minimum detectable entrainment mortality, confidence interval width, and type II error for a given level of type I error.The results of this study are considered in the context of designing useful monitoring programs for determining the entrainment mortality fraction. Preliminary estimates of intake survival and the entrainment mortality fraction can be used to obtain estimates of the sample size needed for a specified level of confidence interval width or type II error. Final estimates of the intake survival and the entrainment mortality fraction can be used to determine the minimum detectable entrainment mortality and the type II error.     

Monitoring the formation of trihalomethanes in the effluents from a shrimp hatchery

Formation of trihalomethanes (THM) was monitored at the Laboratório de Camarões Marinhos (LCM) from the Universidade Federal de Santa Catarina. THM could be present because chlorinated effluents from disinfection are discharged from the different hatchery rooms. THM quantification was done through an analytical methodology using Purge&;Trap coupled with a gas chromatograph equipped with an electron capture detector. Relative standard deviation (RSD), limit of detection (LOD) and limit of quantification (LOQ) for the methodology corresponded to the ranges of 8–17%; 0.01–0.03 μg L^?1 and 0.03–0.08 μg L^?1, respectively. Linear working range was of 0.1–8.0 μg L^?1 for all compounds. Enrichment and recovery method was applied to evaluate possible matrix effects and the results varied from 71.2% to 107.9%. LCM was monitored between August and December, 2004. This study showed that THM did not increase with the increase in postlarvae production and also that the aquatic life and the surrounding environment were not affected.     

Factors affecting river health and its assessment over broad geographic ranges: the Western Australian experience

AusRivAS is an Australia-wide program that measures river condition using predictive models to compare the macroinvertebrate families occurring at a river site with those expected if the site were in natural condition. Results of assessment of 685 sites across all major rivers in Western Australia are presented. Most rivers were in relatively natural condition in the northern half of the state where the human population is low and pastoralism is the major land use. In the south, where the human population is higher and agriculture is more intensive, rivers were mostly more disturbed. AusRivAS assessment produced some erroneous results in rivers of the south-west cropping zone because of the lack of appropriate reference site groups and biased distribution of sampling sites. Collecting low numbers of animals from many forested streams, because of low stream productivity and samples that were difficult to sort, also affected assessments. Overall, however, AusRivAs assessment identified catchment processes that were inimical to river health. These processes included salinisation, high nutrient and organic loads, erosion and loss of riparian vegetation. River regulation, channel modification and fire were also associated with river degradation. As is the case with other assessment methods, one-off sampling at individual sites using AusRivAS may be misleading. Seasonal drought, in particular, may make it difficult to relate conditions at the time of sampling to longer-term river health. AusRivAS has shown river condition in Western Australia is not markedly different from other parts of Australia which, as a whole, lacks the substantial segments of severely degraded river systems reported in England.     

Multi-stage sampling for large scale natural resources surveys: a case study of rice and waterfowl

Large-scale sample surveys to estimate abundance and distribution of organisms and their habitats are increasingly important in ecological studies. Multi-stage sampling (MSS) is especially suited to large-scale surveys because of the natural clustering of resources. To illustrate an application, we: (1) designed a stratified MSS to estimate late autumn abundance (kg/ha) of rice seeds in harvested fields as food for waterfowl wintering in the Mississippi Alluvial Valley (MAV); (2) investigated options for improving the MSS design; and (3) compared statistical and cost efficiency of MSS to simulated simple random sampling (SRS). During 2000-2002, we sampled 25-35 landowners per year, 1 or 2 fields per landowner per year, and measured seed mass in 10 soil cores collected within each field. Analysis of variance components and costs for each stage of the survey design indicated that collecting 10 soil cores per field was near the optimum of 11-15, whereas sampling >1 field per landowner provided few benefits because data from fields within landowners were highly correlated. Coefficients of variation (CV) of annual estimates of rice abundance ranged from 0.23 to 0.31 and were limited by variation among landowners and the number of landowners sampled. Design effects representing the statistical efficiency of MSS relative to SRS ranged from 3.2 to 9.0, and simulations indicated SRS would cost, on average, 1.4 times more than MSS because clustering of sample units in MSS decreased travel costs. We recommend MSS as a potential sampling strategy for large-scale natural resource surveys and specifically for future surveys of the availability of rice as food for waterfowl in the MAV and similar areas.