Beach science in the Great Lakes

Monitoring beach waters for human health has led to an increase and evolution of science in the Great Lakes, which includes microbiology, limnology, hydrology, meteorology, epidemiology, and metagenomics, among others. In recent years, concerns over the accuracy of water quality standards at protecting human health have led to a significant interest in understanding the risk associated with water contact in both freshwater and marine environments. Historically, surface waters have been monitored for fecal indicator bacteria (fecal coliforms, Escherichia coli, enterococci), but shortcomings of the analytical test (lengthy assay) have resulted in a re-focusing of scientific efforts to improve public health protection. Research has led to the discovery of widespread populations of fecal indicator bacteria present in natural habitats such as soils, beach sand, and stranded algae. Microbial source tracking has been used to identify the source of these bacteria and subsequently assess their impact on human health. As a result of many findings, attempts have been made to improve monitoring efficiency and efficacy with the use of empirical predictive models and molecular rapid tests. All along, beach managers have actively incorporated new findings into their monitoring programs. With the abundance of research conducted and information gained over the last 25 years, “Beach Science” has emerged, and the Great Lakes have been a focal point for much of the ground-breaking work. Here, we review the accumulated research on microbiological water quality of Great Lakes beaches and provide a historic context to the collaborative efforts that have advanced this emerging science.     

新疆哈密红山金矿床找矿标志探讨

在野外调研的基础上,通过对区域地质背景、矿床地质特征以及控矿因素、矿床成因的研究,指出了红山金矿床的找矿标志.     

Monitoring generic Escherichia coli in reclaimed and surface water used in hydroponically cultivated greenhouse peppers and the influence of fertilizer solutions

Systematic monitoring of indicator microorganisms, such as Escherichia coli, can help to identify potential risk factors for faecal contamination in the agricultural environment. In this study, levels of E. coli in irrigation water (both reclaimed and surface water), water sprayed in humidifiers to regulate ambient humidity, and pepper fruits were assessed in a commercial greenhouse of hydroponically cultivated crops. Additionally, the role of fertilizer solutions as a potential vector of contamination was investigated. Lab-scale studies were also performed to evaluate the influence of fertilizer solutions on the growth/survival of E. coli in irrigation water. As expected, higher levels of E. coli were detected in reclaimed water compared with surface water. No link between E. coli prevalence in irrigation water and presence in fruit could be established. Regarding the fertilizer solutions, E. coli was detected more frequently and in higher levels in the fertilizer solution richer in micronutrients. Low concentrations of E. coli were also present in pulverized water sprayed inside the greenhouse to control humidity. In lab-scale experiments, E. coli showed potential for surviving but not for growing in most fertilizer solutions and irrigation water. Fertilizer solution of HNO₃, was the only solution in which no E. coli were able to survive in the irrigation head and a rapid inactivation was observed in lab-scale tests. These results suggest that there is a low risk of contamination in this agricultural system despite the combination of higher risk irrigation water sources (reclaimed and surface water) and the hydroponic growing system. Nevertheless, special care should be taken regarding the microbiological quality of the agricultural solutions in direct contact with the edible parts of the crop.     

基于高斯混合模型的无线局域网定位算法

目标定位是无线局域网提供位置服务的基础。该文围绕无线局域网目标定位中的定位精度和实时性2个QoS指标,对基于RSSI的定位技术进行研究,提出一种基于高斯混合模型的无线局域网定位算法。该算法由离线训练和在线定位2个阶段组成,采用GMM对RSSI进行建模,降低了系统定位误差,并减少了定位阶段的运算量,提高了定位的实时性。仿真实验结果表明,该算法具有较好的定位精度和实时性。     

紫金桥软件抽油机监控数字化解决方案

通过案例画面论述基于紫金桥软件平台的油田数字化解决方案。给出项目简要需求分析问题和总体方案设计以及重要功能设计。     

Creation of regional added value by regional bioenergy resources

In debates about the positive effects of renewable and bioenergy projects the aspect of generating regional added value is discussed widely. But the real effects, generated by this regional added value stayed up to now on a non-measurable level. In order to expedite the calculation of these important figures, the author presents a field tested method for confidently arriving at useful values. This methodology takes into consideration the ecological, economical and social impact of a given biomass project's implementation. The model enables a comparison between the different renewable energy plants as well as between them and plants and technology of competing alternatives. Regional authorities are hereby enabled to count on a tool for confidently measuring the possible results of various bioenergy utilization technologies. With this knowledge at hand, they could then take qualified decisions towards positive effects for their region. The developed tool allows the definition of adjustable parameters, and therefore it is able to influence the regional framework regarding a more sustainable development.     

A model laboratory system to study the synergistic interaction and growth of environmental Escherichia coli with macrophytic green algae

Escherichia coli, an important fecal indicator bacterium, is known to persist and reproduce in association with Cladophora and other macrophytic algae and environmental substrates. Recent increases in the growth of Cladophora and other macrophytic algae in many of the Laurentian Great Lakes result in the accumulation of large amounts of algal biomass along the shoreline and on beaches. While the Cladophora–E. coli association may pose substantial public health risks, detailed laboratory-based studies have not been done to investigate the bases of the interaction. This is due, in large part, to past inabilities to culture many macrophytic algae under near axenic conditions. Here we describe the development and experimental use of laboratory microcosms to study the synergistic interaction and growth of the green alga Pithophora, a close relative of Cladophora, with environmental E. coli. In the absence of exogenous organic carbon supply, the E. coli population attached to algal filaments increased approximately three orders of magnitude within 72 h of inoculation. Growth of E. coli on Pithophora appeared to be limited by dissolved nitrogen with a concentration of ≥ 66 μg/mL N allowing maximal bacterial growth. In contrast, an environmental strain of Salmonella did not grow under identical conditions in the microcosms, suggesting that this bacterium requires additional growth factors not provided by Cladophora. Since the alga can be maintained in the laboratory for long periods of time, this system allows for further experimentation and understanding of macroalga–microbe interactions.     

基于RVA法的河流生态需水量研究

以河流生态水文变化的指标体系（Indicator of Hydrologic Alteration,IHA）为基础,立足整体河流水文情势的流量谱系,采用变异性范围法（Range of Variability Approach,RVA）,进行基于长系列历史流量资料的河流生态需水量估算,并以山西省5条较大河流的生态敏感断面为对象进行研究。结果表明,利用本方法估算的结果是合理的,可为河流生态需水量的估算和水资源的可持续开发利用提供科学依据。     

Trained sensory panellists’ response to product alcohol content in the projective mapping task: Observations on alcohol content,product complexity and prior knowledge

Projective mapping has been validated as a practical tool for the rapid sensory profiling of brandy products, although repeatability concerns necessitate repeated measurements in larger sample sets. The reason for poor repeatability could be linked to the complexity of the product type, as well as the physical and possibly psychological factors associated with its high alcohol content. To date no information has been published that tested the effect of these specific factors on panellist performance in projective mapping tasks. This study tested the effect of sample complexity and alcohol content on sensory panel repeatability and accuracy in projective mapping, using six types of commercial alcoholic beverages. In a second objective, the study also tested the effect of prior knowledge of alcohol content of a given product set on panellist performance in projective mapping. The results showed that complexity had the biggest impact on panel performance, while alcohol content had a secondary but decisive influence, largely due to its chemosensory fatiguing nature. Knowledge of the product alcohol content appeared to affect individuals differently, and also had an effect on the terminology used by the panellists to describe the products. The study also introduces the Relative Performance Indicator (RPI) as a new panel performance monitoring tool for projective mapping.     

用密切值法优选油田开发方案

为了对油田开发方案进行多因素分析,采用密切值法建立了油田开发方案优选的综合评价指标体系,并针对各影响因素的相对重要性赋予一定权值。实例分析表明,该方法计算简单,可靠。