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611.
Despite low levels of organochlorine contaminants (OCs) in Antarctic biota, some compounds may exceed the levels in equivalent Arctic species, and previous studies have found biochemical evidence of pollutant exposure in south polar skuas (Catharacta maccormicki), a common marine top predator in the region. In this study we examined relationships between fitness components (fecundity and adult return rate between breeding seasons) and concentrations of OCs in this species. In 65 nests, both males and females were caught, and using principal component analyses (PCA) we produced composite measurements (PC1 and PC2) of six highly correlated OCs measured in blood samples. Although the concentrations of OC were below those documented to have reproductive effects in other aquatic birds, we found that the eggs of females with high levels of OCs in the blood hatched later, and their chicks were in poorer condition at hatching, than females with low OC levels. Thus OCs may delay reproduction and reduce foetal growth in the skuas. However, there was no relationship between the parents' OC residues and the occurrence of non-viable eggs, although the proportion of nests containing non-viable eggs was high (47%). Moreover, there were no significant relationships between OCs and reproductive variables in males, even if males had higher OC levels than females, and no associations between OCs and adult return rate between breeding seasons.  相似文献   
612.
We present a conceptual framework that relates agricultural best management practice (BMP) effectiveness with dominant hydrological flow paths to improve nonpoint source (NPS) pollution management. We use the framework to analyze plot, field and watershed scale published studies on BMP effectiveness to develop transferable recommendations for BMP selection and placement at the watershed scale. The framework is based on the location of the restrictive layer in the soil profile and distinguishes three hydrologic land types. Hydrologic land type A has the restrictive layer at the surface and BMPs that increase infiltration are effective. In land type B1, the surface soil has an infiltration rate greater than the prevailing precipitation intensity, but there is a shallow restrictive layer causing lateral flow and saturation excess overland flow. Few structural practices are effective for these land types, but pollutant source management plans can significantly reduce pollutant loading. Hydrologic land type B2 has deep, well‐draining soils without restrictive layers that transport pollutants to groundwater via percolation. Practices that increased pollutant residence time in the mixing layer or increased plant water uptake were found as the most effective BMPs in B2 land types. Matching BMPs to the appropriate land type allows for better targeting of hydrologically sensitive areas within a watershed, and potentially more significant reductions of NPS pollutant loading.  相似文献   
613.
614.
Understanding public risk perception related to possible consequences of climate change is of paramount importance. Not only does risk perception have an important role in shaping climate policy, it is also central in generating support for initiatives for adaptation and mitigation. In order to influence public knowledge and opinion, there is a need to know more about why people have diverging attitudes and perceptions related to climate change and its possible consequences. By using representative survey data for Norway and multivariate analysis, the authors of this article show that differences in attitudes and perceptions are partially explained by factors such as gender, educational background, and people's political preferences. However, an important factor explaining people's perception of climate change and its possible consequences is their direct personal experience of damage caused by climate-related events such as flooding or landslide. Furthermore, the results show that personal experience of damage has the largest impact on the respondents' belief that there will be more natural-resource hazards locally than in Norway or globally. The results also show that merely living in a more exposed area but not having a personal experience of damage does not affect the respondents' concern towards climate change.  相似文献   
615.
There are gaps in the existing climate change adaptation literature concerning the design of spatial planning instruments and the relationship between policy instruments and the sociopolitical barriers to adaptation reform. To help address this gap, this article presents a typology of spatial planning instruments for adaptation and analyses the pattern of instrument choice in Australian planning processes in order to shed light on contextual factors that can impede adaptation. The analysis highlights how policy design can amplify the barriers to adaptation by arranging policy actors in ways inimical to reform and stripping decision makers of the instruments necessary to make and sustain desired policy changes.  相似文献   
616.
The international standards IEC 61508 and IEC 61511, which provide a general framework for the design and implementation of safety instrumented systems, require quantification of the achieved risk reduction, expressed as a safety integrity level (SIL). Human and organisational factors affect the performance of safety instrumented systems during operation and may threaten the achieved SIL, but this is usually not explicitly accounted for. This article presents a new approach to address human and organisational factors in the operational phase of safety instrumented systems. This approach gives a prediction of the operational SIL and can also be used to improve safety. It shows which human and organisational factors are most in need of improvement and it provides guidance for preventive or corrective action. Finally, the approach can be used as part of a SIL monitoring strategy in order to maintain the achieved SIL at the required level during the operational phase.  相似文献   
617.
Summary.  The sampling behavior of the Colorado potato beetle Leptinotarsa decemlineata Say (CPB) involves examination of the surface of potato leaves. It has been suggested that leaf surface compounds (volatiles and cuticular waxes) may be involved in host-plant recognition, acceptance or discrimination. Here we report on the effect of leaf surface extracts of six Polish commercial potato varieties on CPB feeding. We tested the influence of potato leaf surface extracts on CPB adult and larval feeding, then separated the extracts with HPLC, and finally tested the effect of the HPLC-separated fractions on CPB feeding. The bioassays were performed using potato leaf discs deprived of their original surface compounds. Applied to test discs at concentrations ten times higher than natural (10 leaf area equivalent), the extracts deterred CPB adults and larvae from feeding. HPLC-separated fractions composed of alkanes, sesquiterpene hydrocarbons, wax esters, benzoic acid esters, fatty acid methyl, ethyl, isopropyl and phenylethyl esters, aldehydes, ketones, methyl ketones, fatty acids, primary alcohols, β-amyrin and sterols did not affect adult CPB feeding. Similarly, alkanes, sesquiterpene hydrocarbons, wax esters, methyl ketones, sesquiterpene alcohols and secondary alcohols had no effect on larval CPB feeding. The sterol fraction (cholesterol, β-sitosterol and stigmasterol) acted as a phagostimulant to CPB larvae. We isolated a fraction demonstrating a phagodeterrent effect on CPB adults and larvae. The qualitative composition of the deterrent fraction was quite similar in all potato extracts, but there were quantitative differences between the varieties. Much further work is needed to identify the compounds that can produce the deterrent effect.  相似文献   
618.
619.
Excess fungicides can pose a serious threat to the soil environment. Fungicides can lower the microbiological and biochemical activity of soil and lead to yield declines. Soils contaminated with fungicides have to be remediated to maintain the optimal function of soil ecosystems. This study evaluates the effect of neutralizing substances on soil enzymatic activity and the yield of Triticum aestivum L. in soil contaminated with fungicides. Sandy loam (Eutric Cambisols) with pHKCl 7.0 was contaminated with an aqueous solution of Amistar 250 SC and Falcon 460 EC in the following doses: 0 (soil without fungicide – treated as a control), RD (dose recommended by the manufacturer) and 300?×?RD (dose 300-fold higher than the recommended dose). Soil was supplemented with bentonite and basalt meal at a dose of 10?g kg?1 DM of soil (dry mass of soil). The fungicide dose recommended by the manufacturer did not induce changes in soil enzymatic activity or the yield of T. aestivum L. Our findings indicate that the tested fungicides can be safely applied to protect crops against fungal pathogens. However, when applied at the dose of 300?×?RD, the tested fungicides strongly inhibited soil enzymatic activity and disrupted the growth and development of spring wheat. Soil supplementation with bentonite and basalt meal improved the yield of T. aestivum L., and bentonite was more effective in reducing fungicide stress. The analyzed substances were not highly effective in restoring biochemical homeostasis in soil.  相似文献   
620.
Integrated watershed management (IWM) is a priority, especially in semiarid regions that are concurrently affected by population growth, land use change, soil erosion, and poor governance. In developing countries, IWM is often done without any support tool, scientific data, or deep knowledge of territory characteristics. The aim of this study was to present a case study to apply a decision support tool to prioritize areas for territory management. A simple, quantitative multi‐criteria analysis was applied in a semiarid basin of the Ecuadorian Andes to identify the zones of greatest concern for implementation of resource conservation and management practices at a local and regional scale. In addition to describing the current state of the conditions of this basin, our results suggest scenarios of change in relation to official population projections based on spatial analysis of land use change. Analysis resulted in a scattered distribution of priority values within the watershed, so a hierarchical rule was incorporated to define priorities at the subwatershed (SW) scale. Our analysis identified four SW of very high priority and urgent need to implement management practices. Based on projections of future change due to population growth and land cover change, the number of subbasins that require more attention was doubled. Finally, this study includes zones for management or conservation of the land, according to the Sustainable Development Goals.  相似文献   
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