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271.
The purpose of this study was to evaluate polychlorinated biphenyls (PCBs) contamination levels in roe and red deer from north-western Poland and to assess environmental pollution in this area. A quantitative analysis was conducted using a capillary gas chromatography/mass spectrometry method. The mean concentrations of ΣPCBs (sum of PCBs: 28, 52, 101, 138, 153, 180) in liver samples were 30.24±12.35 ng·g?1 of lipid weight (l.w.) in roe deer and 60.13±14.23 ng·g?1 l.w. in red deer, compared with 24.21±10.02 and 45.22±9.77 ng·g?1 in the lungs of roe and red deer, respectively. PCBs 138, 153 and 180 were the dominant congeners in the liver samples of the analysed animals, whereas PCB 138 and 153 in the lungs. TEQs levels calculated for only dioxin-like PCBs were low: 0.32 and 0.29 pg WHO-PCB-TEQ·g?1 fat in liver of red deer and roe deer, respectively. The mean PCB concentrations obtained in our study for organs of roe deer and red deer were several times lower than those reported elsewhere. These findings show that the investigated roe and red deer originated from an area with low levels of PCB contamination.  相似文献   
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In the northern Rocky Mountains, whitebark pine ( Pinus albicaulis ) is rapidly declining as a result of previous fire exclusion policies, mountain pine beetle ( Dendroctonus ponderosae ) outbreaks, and white pine blister rust ( Cronartium ribicola ). Blister rust is potentially the most destructive agent, killing seedlings, cone-bearing branches, and, eventually, mature trees. We examined densities of whitebark pine regeneration and the incidence and severity of blister-rust infection of seedlings and saplings in the 25-year-old Sundance Burn in the Selkirk Range of northern Idaho, an area heavily infected by blister rust. We found that the mean regeneration density of whitebark pine was significantly lower than that of two other comparably aged burns in western Montana. The low density was attributed to the severe damage to the seed source on the burn perimeter, resulting from previous infestation of mountain pine beetle and blister rust. Overall, 29% of the whitebark pine regeneration in the Sundance Burn was infected by blister rust. Age and height of seedlings were important predictors of incidence of infection, and height was the most important predictor of severity of infection. Thus, as seedlings grow larger, they present a bigger target to airborne blister-rust spores. Because of the lack of seed production in the adjacent forest and expected mortality, regeneration of whitebark pine in the Sundance Burn will be slow. In areas of northern Idaho and northwestern Montana affected by blister rust and pine beetle, prescribed fires for managing whitebark pine ecosystems should be restricted to small areas or should require plantings of rust-resistant seedlings.  相似文献   
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ABSTRACT: Application of synographic techniques to four separate nonrelated research tasks demonstrated the usefulness of such an approach in interpreting and communicating hydrologic survey data especially when large geographic areas are involved. Nutrient exchange and biotic indicators in coastal estuaries were analyzed to determine residence times in different seasons of the year. Man induced changes in urban runoff patterns were shown to increase the probability of flooding with different recurrences of storm events. Nitrate and indicator bacteria in private wells were analyzed on a county-wide basis to determine the sources and extent of natural occurrence versus contamination origins. Water wells and the surface supply of metropolitan Houston were analyzed for sodium content to assist citizens and physicians with data which are needed for derivation of sodium restricted therapeutic diets.  相似文献   
276.
This paper identifies the literature that deals with adaptation to climate change in the transport sector. It presents a systematic review of the adaptations suggested in the literature. Although it is frequently claimed that this socially and economically important sector is particularly vulnerable to climate change, there is comparatively little research into its adaptation. The 63 sources we found are analysed following an action framework of adaptation. This distinguishes different adaptational functions and means of adaptation. By an open coding procedure, a total of 245 adaptations are found and classified. The paper shows a broad diversity of interdependent actors to be relevant—ranging from transportation providers to public and private actors and households. Crucial actors are hybrid in terms of being public or private. A substantial share of the identified adaptations follows a top-down adaptation policy pattern where a public or hybrid operator initiates action that affects private actors. Most of the exceptions from this pattern are technical or engineering measures. Identified adaptations mostly require institutional means, followed by technical means, and knowledge. Generally, knowledge on adapting transport to climate change is still in a stage of infancy. The existing literature either focuses on overly general adaptations, or on detailed technical measures. Further research is needed on the actual implementation of adaptation, and on more precise institutional instruments that fill the gap between too vague and too site-specific adaptations.  相似文献   
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Environmental Science and Pollution Research - Mangrove crabs are ecosystem engineers through their bioturbation activity. On Mayotte Island, the abundance of Neosarmatium africanum decreased in...  相似文献   
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A new apparatus has been designed for investigating flame propagation in turbulent dust clouds at near constant pressure conditions. The experimental approach is inspired by the classical soap bubble method for measuring burning velocities in gaseous mixtures. Combustible dust is dispersed with pressurised air to form an explosive mixture inside a transparent latex balloon. After a certain delay time, the turbulent dust cloud is ignited by a 40 J chemical igniter. A digital high-speed video camera records the propagating flame and the expansion of the balloon. Experiments were performed with two types of dust, Lycopódium spores and maize starch, as well as with propane–air mixtures under initially quiescent or turbulent conditions. Although the results are primarily qualitative in nature, they nevertheless demonstrate fundamental differences between premixed combustion of gaseous mixtures, and ‘premixed combustion with non-premixed substructures' in mechanical suspensions of solid particles dispersed in air. The discussion highlights some fundamental challenges for future dust explosion research.  相似文献   
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