Objective: The present study investigated the relationships between safety climate and driving behavior and crash involvement.
Methods: A total of 339 company-employed truck drivers completed a questionnaire that measured their perceptions of safety climate, crash record, speed choice, and aberrant driving behaviors (errors, lapses, and violations).
Results: Although there was no direct relationship between the drivers' perceptions of safety climate and crash involvement, safety climate was a significant predictor of engagement in risky driving behaviors, which were in turn predictive of crash involvement.
Conclusions: This research shows that safety climate may offer an important starting point for interventions aimed at reducing risky driving behavior and thus fewer vehicle collisions. 相似文献
A general and intuitive prediction from models of mate preference is that when the cost of searching for mates increases,
individuals should become less choosy. Here, we test this prediction by comparing the mating propensity of females in two
populations of the butterfly Pararge aegeria. The populations originated from southern Sweden and Madeira and due to different adult emergence patterns throughout the
year, the average density of males per female is likely to be lower on Madeira. Therefore, we expected that the cost of searching
should be greater on Madeira and, consequently, that the Madeiran females should be less choosy. In line with predictions,
the Madeiran females mated significantly sooner after the first interaction with males than did females from southern Sweden.
This difference may reflect a weaker preference for territorial males over non-territorial patrollers in the Madeiran population,
because of the greater costs of searching. The Madeiran females also showed a shorter time lag between mating and the start
of oviposition. We discuss this unexpected result and propose that the same mechanism could also explain this population difference,
i.e. different costs of searching for suitable host plants. Both search processes are fundamental for female reproductive
success and we find it plausible that they can be generalised into the same theory of optimal search behaviour.
Received: 14 May 1998 / Accepted after revision: 13 December 1998 相似文献
During 1996-1998, 16 fruit bodies of different species and 204 soil samples down to 10 cm in the close vicinity of the fruit body sites were collected in a coniferous forest in the Ovruch region of Ukraine. The soil samples were sliced into 1 or 2 cm layers and the fungal mycelium was prepared from each of the layers. The 137Cs activity concentration was determined in both soil and mycelium. The mean weight of fungal mycelium was 13.8 mg g(-1) of soil in the upper 4 cm and 7.3 mg g(-1) when measured for the upper 10 cm. At the sites of Paxillus involutus and Sarcodon imbricatus, the mycelium was rather homogeneously distributed in the upper 10 cm and at sites of Xerocomus subtomentosus and Cantharellus cibarius, the mycelium was distributed mostly in the upper layers. The highest 137Cs activity concentrations were found in the upper layers of the soil profile. The 137Cs activity concentrations were usually higher in the fruit bodies compared with the mycelium, with ratios ranging from 0.1 to 66 and a mean of 9.9. The percentage of the total inventory of 137Cs in the soil found in the fungal mycelium ranged from 0.1 to 50%, with a mean value of 15%. 相似文献
Metallurgic industry is a source of serious environmental pollution related to the emission of heavy metals. Freshwater systems are focal points for pollution, acting as sinks for contaminants that may end up in fish and humans. The Pasvik watercourse in the border area between Finland, Norway and Russia is located in the vicinity of the Pechenganickel metallurgic enterprises, and the lower part of the watershed drains the Nikel smelters directly through Lake Kuetsjarvi. Heavy metal (Ni, Cu, Cd, Zn, Pb and Hg) concentrations in environment (water and sediments) and whitefish Coregonus lavaretus tissue (gills, liver, kidney and muscle) were contrasted between five lake localities situated along a spatial gradient of increasing distance (5-100 km) to the smelters. The heavy metal concentrations, in particular Ni, Cu and Cd, were highly elevated in Kuetsjarvi, but steeply declined with increasing distance to the smelters and were moderate or low in the other four localities. The study demonstrates that the majority of metal emissions and runoffs are deposited near the pollution source, and only moderate amounts of the heavy metal contaminants seem to be transported at further distances. Bioaccumulation of Hg occurred in all investigated tissues, and higher Hg concentrations in planktivorous versus benthivorous whitefish furthermore indicated that pelagic foraging is associated with higher levels of Hg biomagnification. Potential population ecology impacts of high heavy metal contaminations where mainly observed in whitefish in Kuetsjarvi, which showed depletions in growth rate, condition factor and size and age at maturation. 相似文献