Validation of qPCR method for enterococci quantification at Toronto beaches: Application for rapid recreational water monitoring

Rapid quantitative PCR-based methods for enterococci monitoring can allow public health authorities to make more timely beach posting decisions. However, qPCR methods must be assessed for proposed sites as locale-specific factors may affect DNA recovery or qPCR inhibition. We assessed the feasibility of the USEPA 1609.1 qPCR-based (Enterococcus) method at two urban Toronto beaches and three recreational areas at nearby river mouths in parallel with culture-based methods on the same water samples. A strong positive correlation was observed between the Enterococcus qPCR method and culturing-based quantification methods for E. coli and enterococci at both beaches and two river mouth areas. One river, known to be highly sewage-impacted, did not yield DNA suitable for qPCR analyses. qPCR results from biological replicates were strongly correlated and showed coefficients of variation as low as or lower than culture-based methods. With respect to Beach Action Value exceedances, the USEPA 1609.1 qPCR method provided an 80–90% level of agreement with E. coli enumeration results and >90% with enterococci enumeration. Results indicated that if recreational water locations and sampling conditions met the requirements of the USEPA 1609.1 qPCR method, the method can meet or exceed all quality control requirements and provide water quality results within 3.5 h for diverse recreational water settings around the City of Toronto.     

Efficacy of monitoring and empirical predictive modeling at improving public health protection at Chicago beaches

Efforts to improve public health protection in recreational swimming waters have focused on obtaining real-time estimates of water quality. Current monitoring techniques rely on the time-intensive culturing of fecal indicator bacteria (FIB) from water samples, but rapidly changing FIB concentrations result in management errors that lead to the public being exposed to high FIB concentrations (type II error) or beaches being closed despite acceptable water quality (type I error). Empirical predictive models may provide a rapid solution, but their effectiveness at improving health protection has not been adequately assessed. We sought to determine if emerging monitoring approaches could effectively reduce risk of illness exposure by minimizing management errors. We examined four monitoring approaches (inactive, current protocol, a single predictive model for all beaches, and individual models for each beach) with increasing refinement at 14 Chicago beaches using historical monitoring and hydrometeorological data and compared management outcomes using different standards for decision-making. Predictability (R²) of FIB concentration improved with model refinement at all beaches but one. Predictive models did not always reduce the number of management errors and therefore the overall illness burden. Use of a Chicago-specific single-sample standard—rather than the default 235 E. coli CFU/100 ml widely used—together with predictive modeling resulted in the greatest number of open beach days without any increase in public health risk. These results emphasize that emerging monitoring approaches such as empirical models are not equally applicable at all beaches, and combining monitoring approaches may expand beach access.     

49-2游泳池式反应堆超设计基准事故的筛选与分析

为保证49-2游泳池式反应堆在超寿期下的安全运行,需进行超设计基准事故分析。由于难以采用概率安全评价(PSA)方法进行分析,所以本文无条件假设最严重事故来得到一保守结果。主要分析了全厂断电下未能紧急停堆的预期瞬变(ATWS)、水平孔道断裂和停堆后堆芯完全裸露的事故,以及应急能力。结果表明:在全厂断电ATWS下堆芯是安全的;水平孔道断裂及其他因素造成失水时,只要2.5h内堆芯不裸露即可保证燃料元件不熔化;非能动破坏虹吸能力和多样的应急补水方式能保证堆芯不裸露。     

Electromyography applied to sport ergonomics

Abstract

The improvement of electromyographic (EMG) devices for the detection of electric potentials produced in voluntary complex movements and the evolution of methodological approaches to data acquisition and computerized analysis of patterns, are responsible for the increased applications of EMG in bioengineering, rehabilitation, sport and occupational biomechanics, physiology and zoology and to a lesser extent in ergonomics. This paper describes three different EMG applications related to a sport environment using three different EMG registration and data acquisition approaches.

The first study examined the relation between the swimming action in water and its simulation using training equipment on land. It was found that with respect to the mechanical aspects of dry-land equipment and to the biomechanical differences in the execution of the front crawl action on dry land and in water, based on EMG activity of the propulsion muscles, the best results were found when using devices with accommodating resistance. Recovery muscles were best imitated using isokinetics, but despite the greater effort on land, lower EMG activity was recorded than in water. It was generally observed that whenever the swimmer acted against a mechanical resistance an important pattern deviation was noted.

Second, a study to determine the influence of ski materials on the EMG muscle activity of skiers showed systematic differences between the use of racing, soft and compact skis. The results supported the idea that the soft ski should be more highly recommended than the compact or racing ski for both general and competive use.

Finally, in a third study we found that there was a very high degree of similarity in the pattern and intensity of muscle activity in both free swimming and swimming against a mechanical resistance (MAD swimming), even though the kinesiological aspects of the movement trajectory were proved different beforehand.     

Dynamic real‐time monitoring of chloroform in an indoor swimming pool air using open‐path Fourier transform infrared spectroscopy

This study used open‐path Fourier transform infrared (OP‐FTIR) spectroscopy to continuously assess the variation in chloroform concentrations in the air of an indoor swimming pool. Variables affecting the concentrations of chloroform in air were also monitored. The results showed that chloroform concentrations in air varied significantly during the time of operation of the swimming pool and that there were two peaks in chloroform concentration during the time of operation of the pool. The highest concentration was at 17:30, which is coincident with the time with the highest number of swimmers in the pool in a day. The swimmer load was one of the most important factors influencing the chloroform concentration in the air. When the number of swimmers surpassed 40, the concentrations of chloroform were on average 4.4 times higher than the concentration measured without swimmers in the pool. According to the results of this study, we suggest that those who swim regularly should avoid times with highest number of swimmers, in order to decrease the risk of exposure to high concentrations of chloroform. It is also recommended that an automatic mechanical ventilation system is installed to increase the ventilation rate during times of high swimmer load.     

Swimming pools as heat sinks for air conditioners: Model design and experimental validation for natural thermal behavior of the pool

Swimming pools as thermal sinks for air conditioners could save approximately 40% on peak cooling power and 30% of overall cooling energy, compared to standard residential air conditioning. Heat dissipation from pools in semi-arid climates with large diurnal temperature shifts is such that pool heating and space cooling may occur concurrently; in which case heat rejected from cooling equipment could directly displace pool heating energy, while also improving space cooling efficiency. The performance of such a system relies on the natural temperature regulation of swimming pools governed by evaporative and convective heat exchange with the air, radiative heat exchange with the sky, and conductive heat exchange with the ground. This paper describes and validates a model that uses meteorological data to accurately predict the hourly temperature of a swimming pool to within 1.1 °C maximum error over the period of observation. A thorough review of literature guided our choice of the most appropriate set of equations to describe the natural mass and energy exchange between a swimming pool and the environment. Monitoring of a pool in Davis, CA, was used to confirm the resulting simulations. Comparison of predicted and observed pool temperature for all hours over a 56 day experimental period shows an R-squared relatedness of 0.967.     

Measuring overall thermal comfort to balance energy use in sports facilities

A study for the development of a monitoring methodology that includes thermal comfort in a smart metering system for sports facilities is presented. The scope of this system is to obtain meaningful information on how energy is used in relation to the level of comfort perceived, so as to allow fully informed management operations. The main problem to be addressed is the accurate quantitative measurement of the thermal comfort inside indoor sports areas (e.g. swimming pools, fitness rooms, etc.), which in this work is estimated through the PMV (Predicted Mean Vote) index. The paper describes what needs to be dynamically measured, which parameters are required, which critical uncertainty factors may arise and how to estimate the indicators. A sensitivity and uncertainty analysis for the PMV measurement in this specific application is performed to develop a simplified approach. The results obtained from the measurement campaigns made in two different sports areas are presented to validate the approach. Finally, a simulation of swimming pool data is used to preliminarily demonstrate the feasibility and effectiveness of the global monitoring system proposed.     

电泳涂料

本文介绍了电泳涂料及发展趋势。     

元坝长兴组气藏礁滩沉积微相地质特征及测井识别

元坝气田长兴组气藏主要发育生物礁相和生屑滩相储层。生物礁与非生物礁地层由于生长环境、形态及岩石结构特征差异,测井响应特征不同。利用电成像和常规测井资料,对这些特征差异进行了详细描述,论述了滩核、滩缘和滩间的测井响应特征。长兴组气藏礁相地层沉积模式纵向上表现为礁基—礁核—礁盖—礁核—礁盖,共发育2期礁盖储层,优质储层主要集中在礁盖。滩核、滩缘与滩间测井响应特征的区别在于滩间处于低能沉积环境,自然伽马较高(30~80API之间)、呈指型和尖峰状,滩核和滩缘处于高能和较高能沉积环境,自然伽马为低值(小于20API);滩核与滩缘区别在于滩核电阻率呈隆起状、电成像可见交错层理、溶蚀孔洞发育,滩缘电阻率呈锯齿状,为低角度层理,夹少量溶蚀薄层。滩体分布广泛,但优质储层主要集中在滩核,滩间几乎不发育储层。整合岩心、测井、地震资料和区域地质背景,建立了元坝气田长兴组生物礁及生屑滩的测井识别模式。     

Editorial

Ozone applications in Canada began in 1954 and have shown continuous growth with the largest installation at the Charles des Baillets drinking water plant in the city of Montreal. Many systems have been installed for treatment of swimming pools, odor control and, in particular, cooling towers. One of the world's largest cooling tower applications is at the Alberta Natural Gas Plant. The use of ozone is expected to continue to grow.