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991.
The radio-labile fraction of cadmium, in a wide range of contaminated soils, was studied in relation to fractions of cadmium defined by traditional extraction procedures. The proportion of labile Cd which was exchangeable was highly pH-dependent, but above pH 5 only about 5% of labile Cd was extractable with 1 m KNO(3). By contrast, EDTA released more than the labile Cd pool into solution, suggesting that significant dissolution of metal adsorbents may occur when chelating agents are utilised as trace metal extractants. The effect of time in immobilising Cd added to soil was also illustrated by following changes in the radio-labile Cd concentration. In calcareous soils, an instantaneous 'fixation' reaction as well as a time-dependent transfer to non-labile pools was identified. It is suggested that radio-labile Cd represents a relatively unambiguous assessment of the chemical and biological reactivity of Cd in soil compared with the fractions isolated by chemical extractants. 相似文献
992.
An investigation is presented on industrial contamination by benzotrifluoride percolation into ground water used for drinking water, in a populated area of 20 km2 at Trissino, north Italy, due to improper chemical waste disposal. Hydrogeological features of the situation are reported, as well as the emergency action taken, such as the surveys made and their analytical results. The epidemiology of the emergency is examined and rehabilitation measures are presented and discussed. Fortunately no major ecological or social disaster occurred, In part thanks to the speed and efficiency with which the affair was handled. It is notable that the authorities kept the public duly informed and thus retained their confidence. 相似文献
993.
Jennifer Atlee 《Journal of Cleaner Production》2011,19(5):459-463
In recent years the green building movement has focused increased attention on chemical hazards in building products and the need to select safer alternatives. This paper describes a number of tools available to architects and other building professionals and explores the product evaluation process behind one resource, BuildingGreen’s GreenSpec directory, as a window into the imperfect reality of alternatives assessment in the building design field. 相似文献
994.
Zi-Yan Fan Young Soo Keum Qing-Xiao Li Weilin L. Shelver Liang-Hong Guo 《环境科学学报(英文版)》2012,24(7):1334-1340
An indirect competitive fluorescence immunoassay using a DNA/dye conjugate as antibody multiple labels was developed on 96-well plates for the identification and quantification of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) in aqueous samples. A hapten, 2,4,2′-tribromodiphenyl ether-4′-aldehyde, was synthesized, and was conjugated to bovine serum albumin to form a coating antigen. Specific recognition of the antigen by anti-PBDE antiserum was confirmed by a surface plasmon resonance measurement. In the immunoassay, the coating antigen was adsorbed on a 96-well plate first, and a sample, antiserum and biotinylated goat anti-rabbit secondary antibody were then added and reacted sequentially. A biotinylated, double-stranded DNA with 219 base pairs was attached to the secondary antibody by using streptavidin as a molecular bridge. In situ multiple labeling of the antibody was accomplished after addition of a DNA-binding fluorescent dye, SYBR Green I. The working range of the immunoassay for the BDE-47 standard was 3.1-390 μg/L, with an IC50 value of 15.6 μg/L. The calculated LOD of the immunoassay is 0.73 μg/L. The immunoassay demonstrated relatively high selectivity for BDE-47, showing very low cross-reactivity (< 3%) with BDE-15, BDE-153 and BDE-209. With a spiked river water sample containing 50 μup g/L BDE-47, quantification by the immunoassay was 41.9 μg/L, which compared well with the standard GC-ECD method (45.7 μg/L). The developed immunoassay provides a rapid screening tool for polybrominated diphenyl ethers in environmental samples. 相似文献
995.
Jennifer Verlaine Lukovich Gordon A. McBean 《Mitigation and Adaptation Strategies for Global Change》2009,14(8):697-710
Human security, particularly in the Arctic, is being stressed by climate change and other factors. Science and technology
provide one instrument for the development of strategies that will protect those living in the Arctic from threats to environmental,
social and economic conditions, namely human security, incurred by climate change. This paper explores a public good approach
to Canada’s Science and Technology (S&T) strategy. Investigated in particular is the role of science and technology in addressing
Arctic human security needs, using evolving Organisation for Economic Co-operation and Development (OECD) quality-of-life
indicators to measure the ability of Canada’s S&T strategy to meet these needs. 相似文献
996.
A displacement factor can express the efficiency of using biomass to reduce net greenhouse gas (GHG) emission, by quantifying the amount of emission reduction achieved per unit of wood use. Here we integrate data from 21 different international studies in a meta-analysis of the displacement factors of wood products substituted in place of non-wood materials. We calculate the displacement factors in consistent units of tons of carbon (tC) of emission reduction per tC in wood product. The displacement factors range from a low of ?2.3 to a high of 15, with most lying in the range of 1.0 to 3.0. The average displacement factor value is 2.1, meaning that for each tC in wood products substituted in place of non-wood products, there occurs an average GHG emission reduction of approximately 2.1 tC. Expressed in other units, this value corresponds to roughly 3.9 t CO2 eq emission reduction per ton of dry wood used. The few cases of negative displacement factors are the result of worst-case scenarios that are unrealistic in current practice. This meta-analysis quantifies the range of GHG benefits of wood substitution, and provides a clear climate rationale for increasing wood substitution in place of other products, provided that forests are sustainably managed and that wood residues are used responsibly. 相似文献
997.
Phenotypic plasticity could be a key mechanism of successful species invasion. Few studies, however, have evaluated whether a non-indigenous species induces anti-herbivore defenses after its introduction to new habitats. We tested how a non-indigenous (Mastocarpus stellatus) and a native red seaweed (Chondrus crispus) responded to grazing by a periwinkle (Littorina littorea) and an isopod (Idotea granulosa) in Helgoland, Germany. In the donor region of the Mastocarpus population, that is Iceland, the periwinkle is missing, whereas the isopod is present. Our results indicate that Mastocarpus experienced less consumption by Littorina (but not by Idotea) than Chondrus. Moreover, Mastocarpus induced defenses in response to Idotea (but not to Littorina) grazing, whereas Chondrus induced anti-herbivory responses to both species of herbivores. Grazed Mastocarpus grew equally to non-grazed conspecifics, while growth of grazed Chondrus was lower than of ungrazed conspecifics. Hence, the non-indigenous Mastocarpus responded differently to grazing stress than the native Chondrus with respect to anti-herbivory and compensatory responses, which perhaps supported the successful Mastocarpus establishment in a new range. 相似文献
998.
Douglas J. McCauley Fiorenza Micheli Hillary S. Young Derek P. Tittensor Daniel R. Brumbaugh Elizabeth M. P. Madin Katherine E. Holmes Jennifer E. Smith Heike K. Lotze Paul A. DeSalles Suzanne N. Arnold Boris Worm 《Marine Biology》2010,157(12):2739-2750
Large animals are severely depleted in many ecosystems, yet we are only beginning to understand the ecological implications of their loss. To empirically measure the short-term effects of removing large animals from an ocean ecosystem, we used exclosures to remove large fish from a near-pristine coral reef at Palmyra Atoll, Central Pacific Ocean. We identified a range of effects that followed from the removal of these large fish. These effects were revealed within weeks of their removal. Removing large fish (1) altered the behavior of prey fish; (2) reduced rates of herbivory on certain species of reef algae; (3) had both direct positive (reduced mortality of coral recruits) and indirect negative (through reduced grazing pressure on competitive algae) impacts on recruiting corals; and (4) tended to decrease abundances of small mobile benthic invertebrates. Results of this kind help advance our understanding of the ecological importance of large animals in ecosystems. 相似文献
999.
Jock W. Young Matt J. Lansdell Robert A. Campbell Scott P. Cooper Francis Juanes Michaela A. Guest 《Marine Biology》2010,157(11):2347-2368
We examined the feeding ecology and niche segregation of the ten most abundant fish species caught by longline operations
off eastern Australia between 1992 and 2006. Diets of 3,562 individuals were examined. Hook timer data were collected from
a further 328 fish to examine feeding behaviour in relation to depth and time of day. Prey biomass was significantly related
to predator species, predator length and year and latitude of capture. Although the fish examined fed on a mix of fish, squid
and crustacea, fish dominated the diet of all species except small albacore (Thunnus alalunga) which fed mainly on crustacea and large swordfish (Xiphias gladius) and albacore which fed mainly on squid. Cannibalism was observed in lancetfish (Alepisaurus spp.). Multidimensional scaling identified three species groups based on their diet composition. One group consisted of yellowfin
tuna (T. albacares), striped marlin (Tetrapturus audax) and dolphinfish (Coryphaena hippurus); a second group consisted of bigeye tuna (T. obesus), swordfish and albacore; and a third consisted of southern bluefin tuna (T. maccoyii) and blue shark (Prionace glauca). Of note was the separation of mako shark (Isurus oxyrhynchus) and lancetfish from all other predators. Prey length generally increased with increasing predator length although even large
predators fed on a wide range of prey lengths including very small prey. Overall, differences in prey type and size, feeding
times and depths were noted across the range of species examined to the extent that predators with overlapping prey, either
in type or size, fed at different times of the diel period or at different depths. Taken together these data provide evidence
for feeding niche segregation across the range of oceanic top predators examined. 相似文献
1000.
Petra?M.?KuhnertEmail author Leanne?M.?Duffy Jock?W.?Young Robert?J.?Olson 《Marine Biology》2012,159(1):87-100
We provided a classification tree modeling framework for investigating complex feeding relationships and illustrated the method
using stomach contents data for yellowfin tuna (Thunnus albacares) collected by longline fishing gear deployed off eastern Australia between 1992 and 2006. The non-parametric method is both
exploratory and predictive, can be applied to varying size datasets and therefore is not restricted to a minimum sample size.
The method uses a bootstrap approach to provide standard errors of predicted prey proportions, variable importance measures
to highlight important variables and partial dependence plots to explore the relationships between explanatory variables and
predicted prey composition. Our results supported previous studies of yellowfin tuna feeding ecology in the region. However,
the method provided a number of novel insights. For example, significant differences were noted in the prey of yellowfin tuna
sampled north of 20°S in summer where oligotrophic waters dominate. The analysis also identified that sea-surface temperature,
latitude and yellowfin size were the most important variables associated with dietary differences. The methodology is appropriate
for delineating ecosystem-level trophic dynamics, as it can easily incorporate large datasets comprising multiple predators
to explore trophic interactions among members of a community. Broad-scale relationships among explanatory variables (environmental,
biological, temporal and spatial) and prey composition elucidated by this method then serve to focus and lend validity to
subsequent fine-scale analyses of important parameters using standard diet methods and chemical tracers such as stable isotopes. 相似文献