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281.
ION‐SELECTIVE ELECTRODES IN ANALYTICAL CHEMISTRY, Vol. 2 by H. Freiser (ed.), Plenum Press, New York, 1980. CARCINOGENESIS AND MUTAGENESIS by Myron A. Mehlman, Morris F. Cranmer and Raymond E. Shapiro, from the Journal of Environmental Pathology and Toxicology (Official Organ of the American College of Toxicology), 388 pages and 135 tables and figures, 1977, linen, format 261 × 178 mm, ISBN 0–930376–02–1, printed by Pathotox Publishers, Inc., Park Forest South, Illinois 60466, $23.00. 相似文献
282.
Giuliano Cecchi William Wint Alexandra Shaw Andrea Marletta Raffaele Mattioli Timothy Robinson 《Agriculture, ecosystems & environment》2010,135(1-2):98-110
The central role played by livestock in the livelihoods of rural households in the developing world is seldom fully appreciated by policy makers, development agencies and donors. Knowledge gaps in the geographic distribution and environmental determinants of farming systems, especially if viewed through the livestock lens, compound this problem. We have produced a map of pastoral, agro-pastoral and mixed farming systems across Eastern Africa, by analysing datasets collected in the framework of livelihood analysis. Input data were gathered between 2000 and 2007 by various emergency and development agencies for Djibouti, Eritrea, Kenya, Somalia, Uganda and parts of Ethiopia and Sudan. A quantitative definition of the production systems is adopted, based on the ratio of livestock- to crop-derived income. The resulting livelihood-based map of livestock production systems was compared through correspondence analysis to an alternative livestock production systems map, produced independently from environmental data. Convergence between the two mapping approaches was evident. The geographic distribution of the livestock production systems was also modelled using multivariate analysis of remotely sensed and other geospatial datasets. Models show high statistical accuracy, and were thus used to fill the gaps in the observed distribution of livestock production systems. Finally, selected environmental factors underpinning the systems (agro-climatology, human and livestock populations and land cover) were analysed in detail, enabling the livestock production systems to be characterized in terms of them. The regional scope of the map, as well as its direct link with a vast amount of livelihood information, render it a valuable tool for a range of development and research applications, including those related to global change. 相似文献
283.
Habitat type-based bioaccumulation and risk assessment of metal and As contamination in earthworms, beetles and woodlice 总被引:1,自引:0,他引:1
Frouke Vermeulen Nico W. Van den Brink Helga D'Hav Valentine K. Mubiana Ronny Blust Lieven Bervoets Wim De Coen 《Environmental pollution (Barking, Essex : 1987)》2009,157(11):3098-3105
The present study investigated the contribution of environmental factors to the accumulation of As, Cd, Cu, Pb and Zn in earthworms, beetles and woodlice, and framed within an exposure assessment of the European hedgehog. Soil and invertebrate samples were collected in three distinct habitat types. Results showed habitat-specific differences in soil and invertebrate metal concentrations and bioaccumulation factors when normalized to soil metal concentration. Further multiple regression analysis showed residual variability (habitat differences) in bioaccumulation that could not be fully explained by differences in soil metal contamination, pH or organic carbon (OC). Therefore, the study demonstrated that in bioaccumulation studies involving terrestrial invertebrates or in risk assessment of metals, it is not sufficient to differentiate habitat types on general soil characteristics such as pH and/or OC alone. Furthermore, simple generic soil risk assessments for Cd and Cu showed that risk characterization was more accurate when performed in a habitat-specific way. 相似文献
284.
William D. Baasel 《Journal of the Air & Waste Management Association (1995)》2013,63(8):866-870
A screening technique has been developed to determine the maximum one-hour ground level concentration of a gaseous emission from a stack located In flat terrain. The method does not require the use of a computer and eliminates the usual trial and error calculations. An infinite mixing height is assumed. It involves a linear or quadratic solution of the gaussian plume diffusion as a function of the effective stack height and a linear approximation of the Briggs plume rise equation. The linear approximation of the former gives results that are within 5 % of the gaussian plume results for stability criteria A, B, and C. For stability criteria D, the difference can be as great as 80%. If a quadratic estimation Is used, the differences are less than 3% for stability criteria A, B, and C, and are within 18% for stability criteria D. A linear approximation is used for the Briggs plume rise equation. This gives results within 4% of the Briggs equation. Overall, this is a simple straightforward approximation which gives results which can be used to determine if more sophisticated procedures are necessary. 相似文献
285.
Benthic community structure, diversity, and productivity in the shallow Barents Sea bank (Svalbard Bank) 总被引:1,自引:0,他引:1
Monika Kędra Paul E. Renaud Hector Andrade Ilona Goszczko William G. Ambrose Jr. 《Marine Biology》2013,160(4):805-819
The Barents Sea is among the most productive areas in the world oceans, and its shallow banks exhibit particularly high rates of primary productivity reaching over 300 g C m?2year?1. Our study focused on the Svalbard Bank, an important feeding area for fishes and whales. In order to investigate how benthic community structure and benthic secondary production vary across environmental gradients and through time, we sampled across the bank and compared results with a similar study conducted 85 years ago. Considerable variability in community structure and function across bank corresponded with differences in the physical structure of the habitat, including currents, sedimentation regimes and sediment type, and overlying water masses. Despite an intensive scallop fishery and climatic shifts that have taken place since the last survey in the 1920s, benthic community structure was very similar to that from the previous survey, suggesting strong system resilience. Primary and secondary production over shallow banks plays a large role in the Barents Sea and may act as a carbon subsidy to surrounding fish populations, of which many are of commercial importance. 相似文献
286.
Are R. Berentsen William C. Pitt John D. Eisemann Richard M. Engeman 《Environmental science and pollution research international》2014,21(3):2283-2288
Invasive rodents (primarily Rattus spp.) are responsible for loss of biodiversity in island ecosystems worldwide. Large-scale rodenticide applications are typically used to eradicate rats and restore ecological communities. In tropical ecosystems, environmental conditions rapidly degrade baits and competition for baits by non-target animals can result in eradication failure. Our objective was to evaluate persistence of rodenticide baits during a rat eradication program on Palmyra Atoll; a remote tropical atoll with intense competition for resources by land crabs. Following aerial application, bait condition was monitored in four terrestrial environments and in the canopy foliage of coconut palms. Ten circular PVC hoops were fixed in place in each of Palmyra’s four primary terrestrial habitats and five rodenticide pellets were placed in each hoop. Five coconut palms were selected in three distinct regions of the atoll. One rodenticide pellet was placed on each of five palm fronds in each coconut palm. Fresh baits were placed in all monitoring locations after each broadcast bait application. Bait condition and survival was monitored for 7 days after the first bait application and 6 days after second application. Bait survival curves differed between applications at most monitoring sites, suggesting a decrease in overall rat activity as a result of rodenticide treatment. One terrestrial site showed near 100 % bait survival after both applications, likely due to low localized rat and crab densities. Median days to pellet disappearance were one and two days for the first and second application, respectively. Differences in survival curves were not detected in canopy sites between bait applications. Median days to pellet disappearance in canopy sites were 2 and 4 days for the first and second application, respectively. Frequent rainfall likely contributed to rapid degradation of bait pellets in coconut palm fronds. 相似文献
287.
William A. McClenny S. Mark Schmidt Keith G. Kronmiller 《Journal of the Air & Waste Management Association (1995)》2013,63(1):64-69
ABSTRACT Dalton's law of partial pressures and the hypothesis that water vapor equilibrium in a canister is identical to that established above liquid water are used to predict the variation of the percent relative humidity (%RH) of air released from canisters used in ambient air sampling, typically 6-L canisters pressurized with 18 L of air. When (and if) the water vapor partial pressure in a canister exceeds its saturation vapor pressure, water vapor condensation begins and the condensation rate equals the sampling rate of water vapor into the canister. Under constant temperature conditions, the air subsequently released from the canister is less humid than the original sample, following the relationship %RH = 100% (6 L/Vs) for Vs> Vr, where Vs is the residual air volume (referenced to atmospheric pressure), and Vr is shown to depend on the %RH of the ambient air sample. Vr is the residual air volume at which water is completely removed (except for adsorbed water vapor) from the canister wall. For Vs < Vr, the predicted %RH is constant and equal to its value at Vr. Experimental values agree reasonably well with predictions at both high (90%) and low (34%) RH. However, experimental values are often slightly displaced (usually towards lower values of %RH) for mid-range %RH (61%) and variations in %RH near Vr change from canister to canister. 相似文献
288.
Wastes, which are the by-products of consumption, are a growing problem in the urban and peri-urban areas of the Lake Victoria region largely due to high urban population growth rates, consumption habits, low collection rates and hence waste accumulation. Whereas the biodegradable proportion is high and could be reutilized, a few have tapped the economic potential of this waste. This study was conducted to explore the potential alternatives and determinants of waste separation and utilization among urban and peri-urban households in the Lake Victoria crescent. A random sample of households in five urban and peri-urban areas of the crescent were selected and surveyed. Logit models were used to establish the factors influencing waste separation and utilization in urban and peri-urban areas of the lake crescent. Results indicate that, gender, peer influence, land size, location of household and membership of environmental organization explain household waste utilization and separation behaviour. Campaigns for waste separation and reuse should be focused in the peri-urban areas where high volumes of wastes are generated and accumulate. Social influence or pressure should be used to encourage more waste reuse and separation. 相似文献
289.
Andrea R. Ferro Neil E. Klepeis Wayne R. Ott William W. Nazaroff Lynn M. Hildemann Paul Switzer 《Atmospheric environment (Oxford, England : 1994)》2009,43(3):706-714
Residential interior door positions influence the pollutant concentrations that result from short-term indoor sources, such as cigarettes, candles, and incense. To elucidate this influence, we reviewed past studies and conducted new experiments in three residences: a single-story 714 m3 ranch-style house, a 510 m3 two-story split-level house, and a 200 m3 two-story house. During the experiments, we released sulfur hexafluoride or carbon monoxide tracer gas over short periods (≤30 min) and measured concentrations in the source room and at least one other (receptor) room for various interior door opening positions. We found that closing a door between rooms effectively prevented transport of air pollutants, reducing the average concentration in the receptor room relative to the source room by 57–100% over exposure periods of 1–8 h. When intervening doors were partially or fully open, the reduction in average concentrations ranged from 3% to 99%, varying as a function of door opening width and the distance between source and receptor rooms. 相似文献
290.
Patrick C. Tobin Julie Van Stappen Laura M. Blackburn 《Journal of environmental management》2010,91(10):1991-1996
The introduction of non-native species has accelerated due to increasing levels of global trade and travel, threatening the composition and function of ecosystems. Upon arrival and successful establishment, biological invaders begin to spread and often do so with considerable assistance from humans. Recreational areas can be especially prone to the problem of accidental non-native species transport given the number of visitors that arrive from geographically diverse areas. In this paper, we examine camping permit data to the Apostle Islands National Lakeshore in northwestern Wisconsin, USA, from 1999 to 2007 relative to gypsy moth distribution, phenology and outbreak data. During this time, gypsy moth populations became established in this area ahead of the moving population front of the gypsy moth, suggesting anthropogenic introduction. The permit data revealed that the majority of visitors arrived from outside of the gypsy moth established area. However, there was a consistent yearly trend of visitors that arrived from areas of high gypsy moth populations and who arrived during the gypsy moth life stage (egg masses) most likely to be successfully introduced. Using available data on the gypsy moth and its relationship to camping permit data, we describe how recreational managers could optimize park strategies to mitigate unwanted introductions of the gypsy moth as well as develop analogous strategies for managing other biological invaders in recreational areas. 相似文献