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BACKGROUND: Most seat belt use laws originally passed in the United States contained language restricting enforcement to drivers already stopped for some other reason. States that have since removed this secondary enforcement restriction have reported increased seat belt use. The purpose of the present study was to estimate the effect of these law changes on driver fatality rates. METHOD: Trends in passenger vehicle driver death rates per billion miles traveled were compared for 10 states that changed from secondary to primary seat belt enforcement and 14 states that remained with secondary enforcement. RESULTS: After accounting for possible economic effects and other general time trends, the change from secondary to primary enforcement was found to reduce annual passenger vehicle driver death rates by an estimated 7% (95% confidence limits 3.0-10.9). CONCLUSION: The majority of U.S. states still have secondary enforcement laws. If these remaining secondary laws were amended, an estimated 696 deaths per year could be prevented. 相似文献
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Allan Blenkharn 《The Environmentalist》1981,1(2):145-156
Summary Guidelines to help resolve conflicts between conservation and land drainage have been published recently. They are addressed to all those who are involved in land drainage, sea defence, and food production as well as those concerned about the need to conserve our wetlands, our rivers and the countryside.The guidelines have been produced so that all elements of land drainage projects—from major schemes down to routine maintenance—can be identified and therefore help towards a better understanding of the problems faced by both sides. Their main message is one of cooperation and consultation.As for the wider aspects of rivers and wetlands, it has been impressed upon us that there is a growing concern about increasing food production from a declining available acreage, and about threats to property and land from higher flood levels. At the same time there is a great awareness of the need to have full regard for the protection of the countryside and its ecological balance.The guidelines seek to demonstrate how essential works of land drainage and sea defence can be achieved not only with least harm to wildlife and nature conservation, but also to enhance them wherever possible. Education, training and research are essential elements in the achievement of guideline objectives, and some programmes are becoming established.Work for this paper and the guidelines was done under the auspices of the Water Space Amenity Commission, London, 1980.Allan Blenkharn is a trained engineer, and before joining the Water Space Amenity Commission he was waterways engineer, and amenity services manager for the British Waterways Board. 相似文献
35.
OBJECTIVE: To determine the characteristics of speeders, defined as drivers of vehicles traveling at least 15 mph above the posted speed limit and relatively faster than surrounding vehicles. METHODS: Vehicle speeds were recorded on 13 roads in Virginia with speed limits ranging from 40 to 55 mph. Speeders were compared with slower drivers, defined as drivers of adjacent vehicles traveling no more than 5 mph above the speed limit. License plates were used to identify vehicle owners; owners were inferred to have been driving if observed gender and estimated age matched those of the registered owner. For these drivers, information on exact driver age and gender, vehicle make and model, and driving record was obtained from the Virginia Department of Motor Vehicles. RESULTS: Five percent of the vehicles observed were traveling at least 15 mph above the limit, and 3% qualified as speeders, as defined in this study. Speeders were younger than drivers in the comparison group, drove newer vehicles, and had more speeding violations and other moving violations on their records. They also had 60% more crashes. DISCUSSION: Speeders are a high-risk group. Their speeding behavior is not likely to be controlled without vigorous, consistent enforcement, including the use of automated technology. 相似文献
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PROBLEM: There is limited information about how parents view teen driving risks and intend to handle these risks during the licensing process, and how they will respond to graduated licensing provisions. METHODS: Parents in Connecticut were interviewed when their teens got their learner's permit. The survey was undertaken when the state did not have a midnight restriction or a passenger restriction. RESULTS: Generally, parents were well aware of teen driving risks, thought parents should be thoroughly involved in the licensing process, and plan to be active participants themselves. DISCUSSION: Parents were concerned about the risk of driving after midnight and already restrict that behavior. However, parents do not seem to see or understand the risks of having even one teen passenger in the vehicle. IMPACT ON INDUSTRY: The views and existing practices of parents need to be taken into account in deciding on the provisions of graduated licensing legislation and how to best ensure acceptance and compliance. 相似文献
37.
The ability of many insects to learn has been documented. However, a limited number of studies examining associative learning in medically important arthropods has been published. Investigations into the associative learning capabilities of Culex
quinquefasciatus Say were conducted by adapting methods commonly used in experiments involving Hymenoptera. Male and female mosquitoes were able to learn a conditioned stimulus that consisted of an odor not normally encountered in nature (synthetic strawberry or vanilla extracts) in association with an unconditioned stimulus consisting of either a sugar (males and females) or blood (females) meal. Such information could lead to a better understanding of the ability of mosquitoes to locate and select host and food resources in nature. 相似文献
38.
In municipal and industrial practices, wastewater treatment sludges are generally conditioned with organic polymers before dewatering. The dewatering polymers are expensive and contribute significantly to the overall sludge management cost. This paper discusses a preconditioning strategy that holds great promise for enhancing dewatering properties of wastewater treatment sludges, while reducing the cost. In this approach, the waste activated sludge (WAS) is briefly preconditioned with an acid before flocculating with an organic polymer. Experimental results showed that acid preconditioning significantly enhanced dewatering. Separately acidifying WAS and subsequently combining it with primary sludge produced higher presscake solids than acidifying the combined sludge to the same final pH. Acidification exhibited the added benefit of reducing Escherichia coli counts in sludge, thus improving its biological character. This may provide flexibility in choosing a beneficial use application. 相似文献
39.
Douglas W. Kuehl Philip M. Cook Allan R. Batterman Douglas B. Lothenbach Brian C. Butterworth Darcy L. Johnson 《Chemosphere》1985,14(5):427-437
The bioavailability of 2,3,7,8-TCDD from municipal incinerator fly ash to freshwater fish was determined. It was observed that carp exposed to fly ash containing all 22 TCDD isomers, or the solvent extract of the fly ash, retain only 2,3,7,8-TCDD. Exposures with fly ash appears to follow a dose response relationship for bioconcentration, however, the bioavailability of 2,3,7,8-TCDD was not directly related to the level of 2,3,7,8-TCDD in fly ash for two fly ash samples studied. 相似文献
40.
Gunderson MP Bermudez DS Bryan TA Degala S Edwards TM Kools SA Milnes MR Woodward AR Guillette LJ 《Chemosphere》2004,56(4):335-345
This 3-year study was designed to examine variation in plasma sex steroids, phallus size, and the standard error (S.E.) associated with these endpoints in juvenile alligators collected from 3 sites within the Kissimmee-Everglades drainage (Florida, USA) with varying concentrations of sediment organochlorine contaminants. We hypothesized that decreased plasma sex steroid concentrations and phallus size would be observed in the higher contaminant site when compared to the intermediate and lower contaminant sites. Furthermore, we hypothesized that greater S.E. associated with these endpoints would be observed for the populations from more contaminated sites. We found that differences existed with females from the higher contaminant site exhibiting lower plasma estradiol-17beta (E2) and testosterone (T) concentrations. Males from the higher contaminant site exhibited smaller phallus sizes than males from the intermediate and lower contaminant sites. Smaller phallus size in this case differed from that reported in Lake Apopka male alligators [Gen. Comp. Endocrinol. 116 (1999) 356] in that a significant positive relationship between body size and phallus size existed. No difference among sites was observed in plasma T for males. Lower S.E. was associated with E2 and T concentrations in females from the higher contaminant site and in phallus size in males from the higher contaminant site. This pattern was opposite to what we had hypothesized. We concluded that variation in plasma E2 and T concentrations, phallus size, and the S.E. associated with these endpoints exists among the 3 sites with the patterns matching the patterns of organochlorine contamination, although S.E. patterns were opposite to what was predicted. 相似文献