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81.
OBJECTIVE: To develop a better understanding of the frequency and characteristics of teenage driver crashes occurring during school commute times. METHOD: Data were obtained from police reports of crashes involving drivers ages 16-17 that occurred between September 2001 and August 2004 in Fairfax County, Virginia. Temporal patterns and other characteristics of crash involvement during the school year were examined, and crashes during school commute times were compared with those at other times. RESULTS: Teenage driver crash involvement spiked during weekday school commute times. Compared with other times, crashes during school commute times were significantly more likely to involve multiple vehicles but less likely to result in injuries or involve drivers who were male, made driving errors, or had been drinking alcohol. Crashes during school commute times were more likely to involve more than one teenage driver and occur close to schools. CONCLUSIONS: Crashes involving teenage drivers are prevalent during school commute times. Many of these crashes involve multiple teenage drivers and occur near schools. Schools and communities should consider programs and policies that reduce teenage driving to school and enhance the safety of teenagers that do drive.  相似文献   
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The levels of six perfluorocarboxylates (PFCAs), four perfloroalkylsulfonates (PFASs), and one sulfonamide were measured in paired samples of maternal serum, umbilical cord serum, and breast milk. The maternal and cord sera were strongly correlated with each other for all measured compounds (r > 0.5 and p < 0.01). Nevertheless, there was a significant difference in compound composition profile between the two sera matrices, with a more depletion of the longer chain compounds in cord serum. The transfer efficiency values from maternal to cord serum (TFCS/MS) decreased by 70% with each increasing unit of -CF2 chain within a PFCA group, and for perfluorooctanesulfonate (PFOS), by a half compared to perfluorooctanoate (PFOA). In contrast to the strong correlation in concentrations between the two sera matrices, the pattern of compounds in breast milk differed considerably with those in sera. Accordingly, compound- and matrix-specific transfer must be considered when assessing prenatal and postnatal exposure.  相似文献   
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A large number of pressurized coal gasification processes being developed propose to use venturi scrubbers for particulate removal at high pressures. Theoretical predictions based on venturi scrubber performance models indicate that particle collection efficiency will decrease severely in these high gas pressure applications.

An exploratory theoretical and experimental program was performed to study the effect of gas pressure on venturi scrubber performance. Experiments were done on a 0.47 m3/s (1000 acfm) pilot scale venturi scrubber. Particle collection performance was determined as a function of scrubber pressure drop for venturi scrubbers operating In the range of 1-10 atm total pressure. Experimental results confirmed that the particle collection efficiency of venturi scrubbers decreases for a given scrubber pressure drop as total gas pressure Is increased. To achieve the same particle collection efficiency, the pressure drop across a venturi scrubber operated at 10 atm Is about 10 times that of the same scrubber operated at 1 atm pressure.  相似文献   
84.
整全,互动和可持续的EIA:香港上水屠宰场的例案研究   总被引:1,自引:0,他引:1  
以香港上水屠宰场的EIA为例,阐述了EIA过程须结合“清洁工艺”、“环境管理系统”、“持续生的本底监测”和“开放的公众咨询”四个重要单元,互动灵活,以增强环保效益、省时及经济。传统的EIA较为被动,如果项目“倡议人”缺乏环保意识,就会妨碍了它的实质功能。通行的末期性公众咨询,很容易激发冲突,与西方冗长的公众参与同样妨碍进度。文章探讨互动式EIA的优点,论证它对改善环评工序和可持续发展的重要性。  相似文献   
85.
Estimation of nutrient load production based on multi-temporal remotely sensed land use data for the Glenelg-Hopkins region in south-west Victoria, Australia, is discussed. Changes in land use were mapped using archived Landsat data and computerised classification techniques. Land use change has been rapid in recent history with 16% of the region transformed in the last 22 years. Total nitrogen and phosphorus loads were estimated using an export coefficient model. The analysis demonstrates an increase in modelled nitrogen and phosphorus loadings from 1980 to 2002. Whilst such increases were suspected from past anecdotal and ad-hoc evidence, our modelling estimated the magnitude of such increases and thus demonstrated the enormous potential of using remote sensing and GIS for monitoring regional scale environmental processes.  相似文献   
86.
Methylmercury exposure and health effects in humans: a worldwide concern   总被引:5,自引:0,他引:5  
The paper builds on existing literature, highlighting current understanding and identifying unresolved issues about MeHg exposure, health effects, and risk assessment, and concludes with a consensus statement. Methylmercury is a potent toxin, bioaccumulated and concentrated through the aquatic food chain, placing at risk people, throughout the globe and across the socioeconomic spectrum, who consume predatory fish or for whom fish is a dietary mainstay. Methylmercury developmental neurotoxicity has constituted the basis for risk assessments and public health policies. Despite gaps in our knowledge on new bioindicators of exposure, factors that influence MeHg uptake and toxicity, toxicokinetics, neurologic and cardiovascular effects in adult populations, and the nutritional benefits and risks from the large number of marine and freshwater fish and fish-eating species, the panel concluded that to preserve human health, all efforts need to be made to reduce and eliminate sources of exposure.  相似文献   
87.
Recent increases in ivory poaching have depressed African elephant populations. Successful enforcement has led to ivory stockpiling. Stockpile destruction is becoming increasingly popular, and most destruction has occurred in the last 5 years. Ivory destruction is intended to send a strong message against ivory consumption, both in promoting a taboo on ivory use and catalyzing policy change. However, there has been no effort to establish the distribution and extent of media reporting on ivory destruction events globally. We analyzed media coverage of the largest ivory destruction event in history (Kenya, 30 April 2016) across 11 nation states connected to ivory trade. We used an online‐media crawling tool to search online media outlets and subjected 5 of the largest print newspapers (by circulation) in 5 nations of interest to content analysis. Most online news on the ivory burn came from the United States (81% of 1944 articles), whereas most of the print news articles came from Kenya (61% of 157 articles). Eighty‐six to 97% of all online articles reported the burn as a positive conservation action, whereas 4–50% discussed ivory burning as having a negative impact on elephant conservation. Most articles discussed law enforcement and trade bans as effective for elephant conservation. There was more relative search interest globally in the 2016 Kenyan ivory burn than any other burn in 5 years. Ours is the first attempt to track the reach of media coverage relative to an ivory burn and provides a case study in tracking the effects of a conservation‐marketing event.  相似文献   
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