Drowsy drivers: The effect of light and circadian rhythm on crash occurrence

Drowsiness has been recognized as a pervasive problem for drivers, with effects comparable to alcohol. Alcohol, however, has a clear legal limit for impairment; there are no comparable criteria to suggest sleepiness. Drowsiness has been associated with light and circadian rhythm. To investigate the joint effects of these factors on crash occurrence, along with other factors, single vehicle crashes reported in Ontario (1999–2004) were analyzed. Crashes occurring at four times of day, when light varies and circadian rhythm is low (2–5 a.m. and 2–4 p.m.) and with similar light conditions and higher circadian rhythm (9–11 p.m. and 10 a.m.–12 noon). Logistic regression was used to see how light and other factors are associated with single vehicle crashes occurring at times of low circadian rhythm, when drowsiness is more likely.Initial results indicated many circumstances associated with occurrence at these times: the age and sex of the driver and reported driver condition as well as weather. There is, however, an interaction between light and presumed alertness. In separate analyses for daytime and night time crashes most variables were significant for nighttime crashes but not for daytime events. The effects of alcohol and youth remained. A lack of light may exacerbate the effects of other factors at times of low alertness; this should be further investigated in controlled environments such as sleep laboratories and/or driving simulators.     

Effects of arsenic on nitrate metabolism in arsenic hyperaccumulating and non-hyperaccumulating ferns

This study investigated the effects of arsenic on the in vitro activities of the enzymes (nitrate reductase and nitrite reductase) involved in nitrate metabolism in the roots, rhizomes, and fronds of four-month old Pteris vittata (arsenic – hyperaccumulator) and Pteris ensiformis (non-arsenic--hyperaccumulator) plants. The arsenic treatments (0, 150, and 300 μM as sodium arsenate) in hydroponics had adverse effects on the root and frond dry weights, and this effect was more evident in P. ensiformis than in P. vittata. Nitrate reductase and nitrite reductase activities of arsenate-treated plants were reduced more in P. ensiformis than in P. vittata. This effect was accompanied by similar decreases in tissue NO₃^? concentrations. Therefore, this decrease is interpreted as being indirect, i.e., the consequence of the reduced NO₃^? uptake and translocation in the plants. The study shows the difference in the tolerance level of the two Pteris species with varying sensitivity to arsenic.     

起重机械作业人员职业适性检测指标研究

采用Ｄｅｌｐｈｉ法对起重机械作业人员职业适性指标进行了研究。咨询专家就各备择指标对工作重要性及发生事故的关系进行了评估。结果表明：专家积极程度与意见集中程度良好；事故重要性与工作重要性排序一致性良好，两者呈高度正相关。依据专家对“重要性”的排序，再通过专家会议与现场考证等方法，最终确定了起重机械作业人员职业适性检测指标体系。     

Bioaccumulation of dichlorodiphenyltrichloroethanes (DDTs) in carp in a water/sediment microcosm: important role of sediment particulate matter and bioturbation

Environmental Science and Pollution Research - Sediments are reservoirs and sources of DDTs to the aquatic ecosystem. However, the role of sediment particulate matter and benthic organisms in...     

From mixed to separate collection of solid waste: Benefits for the town of Zavidovići (Bosnia and Herzegovina)

In Bosnia and Herzegovina only 50% of the municipalities have a well-organized service for (mixed) waste collection and disposal. Illegal dumping is very common, in particular in rural areas, which are not regularly served by any service of collection. This situation leads to serious risks for public health and has dangerous environmental impacts. In Zavidovi?i the municipality is trying to meet high standards in the delivery of services of waste collection, but is constrained by scarce financial and technical resources. Different scenarios for the implementation of a system of separate collection in Zavidovi?i were elaborated in order to provide a useful tool for decision making by comparing costs and environmental & economic benefits of each scenario. Six scenarios were considered, based on different recovery rates for plastic, paper & cardboard, and metals. Benefits resulting from the implementation of each of the proposed scenarios are compared in terms of savings of landfill volume and costs. The study concludes that the adoption of a system of separate collection could generate positive impacts on all the stakeholders involved in the solid waste management sector in Zavidovi?i and could contribute to the compliance of European standards in many Central and Eastern European countries as established by a number of national environmental protection strategies.