Effects of ultraviolet-B radiation on behaviour and growth of three species of amphibian larvae

Effects of ultraviolet-B (UV-B) radiation on amphibian embryos have been investigated in a number of studies, but the effects on larvae have received less attention. We investigated the effects of UV-B radiation on the behaviour and growth of larvae of three amphibians (Rana arvalis, Rana temporaria and Bufo bufo) in two different experiments. First, we tested whether larvae of the three species actively avoid UV-B exposure if given a choice. We found no evidence for active avoidance of UV-B or changes in activity in the presence of UV-B in any of the species. Second, we assessed the effects of natural (1.25 kJm(-2)) and enhanced (1.58 kJm(-2)) UV-B radiation on the survival and growth of the three species and found that the exposure to UV-B radiation did not have any effect on survival rates of any of the species. However, UV-B radiation had a positive effect on the growth of R. arvalis and R. temporaria, whereas the growth of B. bufo tadpoles was unaffected by the UV-B treatments. Our results suggest that a short-term exposure to UV-B radiation does not induce any UV-B avoidance behaviour in tadpoles of these three species. Furthermore, unlike some previous studies, the results suggest that the young tadpoles of these species are not negatively affected by UV-B radiation. In fact, our results demonstrate that a moderate amount of UV-B radiation enhance tadpole growth rates in two of the three species.     

Integrating Environmental Characteristics and Fisheries Management in Northern Finland River Impoundments

/ Three large rivers in northern Finland, the Kemijoki, Iijoki, and Oulujoki rivers, were dammed for hydropower generation in the 1940s-1960s. Due to differences in environmental conditions, these impoundments require detailed study to produce guidelines for fisheries management.Water quality, hydrology, vegetation, and geomorphology data of 16 impoundments were gathered. Shoreline land-use data were derived from maps, and fish assemblage data were collected by exploratory fishing and from the annual fishery statistics. The relations among environmental variables were studied, and a classification of the impoundments was developed by hierarchical cluster analysis. Consequently, three impoundment groups with different environmental characteristics were formed. Significant differences among impoundment groups were also detected in fish yield. We conclude that the variation in environmental conditions, together with differences in fish communities in the impoundments were important enough to justify the claim that impoundments of different types require different management strategies. KEY WORDS: Impoundments; River regulation; Fish assemblage; Water quality; Aquatic vegetation; Finland     

Traffic safety in the U.S.: re-examining major opportunities

INTRODUCTION: This article examines five major road-safety risk factors: exceeding posted speed limits, not using safety belts, driving while intoxicated, nighttime driving, and young drivers. METHOD: The importance of each of these factors is documented, known effective countermeasures (both policy and technology based) are discussed, and impediments to the implementation of these countermeasures in the United States are examined. RESULTS: Based on current understanding of the five major risk factors, and of the available countermeasures, there appear to be a variety of opportunities to make substantial gains in road safety using existing knowledge. The limited implementation of a variety of known countermeasures therefore appears to be inconsistent with high-level, strategic goals to improve road safety. Consequently, a recommendation is made to comprehensively re-examine the balance between the countermeasures discussed in this article and economic, mobility, and privacy concerns. IMPACT ON PUBLIC SAFETY: Such a re-examination is likely to result in broad support for these countermeasures, with a consequent major improvement in road safety.     

Characteristics and availability of fatal road-crash databases in 20 countries worldwide

INTRODUCTION: This study examined the characteristics and availability of fatal road-crash databases worldwide. METHOD: The study involved two parts. First, the major international road databases were briefly reviewed. Second, the national databases in 20 selected countries were examined. RESULTS: (a) the available international databases of fatal road crashes typically include aggregated data; (b) there is a national database of fatal road crashes in each country examined; (c) all countries provide aggregated crash data, but there are substantial restrictions on the availability of disaggregated data; and (d) overall, the crash data at the accident level are relatively similar, but there are substantial differences in the information at the person level. CONCLUSION: The results imply that international road safety research would greatly benefit from expanded availability of disaggregated fatal crash data worldwide.     

Impacts of urbanization at city cluster scale on ecosystem services along an urban–rural gradient: a case study of Central Yunnan City Cluster,China

Environmental Science and Pollution Research - Urban agglomeration will be the main mode of future urbanization in China, greatly influencing social and economic development and ecosystem...