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531.
Characterisation of the complex mixtures of carboxylic acids (naphthenic acids) occurring in crude oils and in degraded oil sands is environmentally important. Indeed some acids in waters from oil platforms are apparently hormonally active, and the oil sands acids are said to be toxic to a wide range of biota. Previous attempts to identify monocyclic and monoaromatic naphthenic acids have been hampered by the lack of authenticated synthetic reference compounds. Some studies have indicated that acids with ethanoic acid side chains are present in the naphthenic acids mixtures, so in the present study, we synthesised and characterised by mass spectrometry, a range (C8–14) of monoaromatic and monocyclic ethanoic acids. Using 2-D comprehensive gas chromatography–mass spectrometry, we then compared the retention times and mass spectra of the synthetic acids with those of a commercial naphthenic acids mixture. Some alicyclic and numerous aromatic acids were successfully identified.  相似文献   
532.
Previous experimental work suggests flexibility in women’s mate preferences that appears to reflect the advantages of choosing healthy mates under conditions of pathogen threat and of choosing prosocial mates under conditions of resource scarcity. Following this work, we used an established priming paradigm to examine the effects of priming women’s concerns about pathogen threat versus resource scarcity on their judgments of men’s facial attractiveness and dominance. We found that women reported stronger attraction to masculine men when their concerns about pathogens were activated than when their concerns about resource scarcity were activated. In contrast, we found that women were more likely to ascribe high dominance to masculine men when their concerns about resource scarcity were activated than when their concerns about pathogens were activated. This latter result may reflect the greater importance of identifying men who pose a substantial threat to women’s resources and personal safety when resources are scarce and violence towards women is particularly common. Together, these findings suggest a double dissociation between the effects of pathogen threat and resource scarcity on women’s perceptions of the attractiveness and dominance of masculine men, potentially revealing considerably greater specialization (i.e., context specificity) in the effects of environmental threats on women’s perceptions of men than was apparent in previous research.  相似文献   
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534.
Reports of toxic harmful algal blooms (HABs) attributed to the diatom Pseudo-nitzschia spp. have been increasing in California during the last several decades. Whether this increase can be attributed to enhanced awareness and monitoring or to a dramatic upswing in the development of HAB events remains unresolved. Given these uncertainties, the ability to accurately and rapidly identify an emerging HAB event is of high importance. Monitoring of HAB species and other pertinent chemical/physical parameters at two piers in southern California, Newport and Redondo Beach, was used to investigate the development of a site-specific bloom definition for identifying emerging domoic acid (DA) events. Emphasis was given to abundances of the Pseudo-nitzschia seriata size category of Pseudo-nitzschia due to the prevalence of this size class in the region. P. seriata bloom thresholds were established for each location based on deviations from their respective long-term mean abundances, allowing the identification of major and minor blooms. Sixty-five percent of blooms identified at Newport Beach coincided with measurable DA concentrations, while 36 % of blooms at Redondo Beach coincided with measurable DA. Bloom definitions allowed for increased specificity in multiple regression analysis of environmental forcing factors significant to the presence of DA and P. seriata. The strongest relationship identified was between P. seriata abundances 2 weeks following upwelling events at Newport Beach.  相似文献   
535.
Zinc (Zn) is a chemical element that has gained more attention lately owing to its possibility to form corrosive deposits in large boilers, such as Waste-to-Energy plants. Zn enters the boilers in many different forms and particularly in waste, the amount of Zn is hard to determine due to both the heterogeneity of waste in general but also due to the fact that little is yet published specifically about the Zn levels in waste. This study aimed to determine the Zn in Swedish waste fuels by taking regular samples from seven different and geographically separate waste combustion plants over a 12-month period. The analysis shows that there is a relation between the municipal solid waste (MSW) content and the Zn-content; high MSW-content gives lower Zn-content. This means that waste combustion plants with a higher share of industrial and commercial waste and/or building and demolition waste would have a higher share of Zn in the fuel. The study also shows that in Sweden, the geographic location of the plant does not have any effect on the Zn-content. Furthermore, it is concluded that different seasons appear not to affect the Zn concentrations significantly. In some plants there was a clear correlation between the Zn-content and the content of other trace metals.  相似文献   
536.
Abstract

The effect of two sublethal fenitrothion concentrations (0.02 and 0.04 mg/L) on the energy metabolism of the european eel Anguilla anguilla and its recovery from intoxication was investigated. Analysis of various parameters such as glycogen, proteins and total lipids was made on liver and muscle eel tissues after 2, 8, 12, 24, 32, 48, 56, 72 and 96 hr of fenitrothion (0,0‐dimethyl 0–3‐methyl‐4‐nitrophenyl phosphorothioate) exposure. Subsequently, the fish were allowed recovery periods of 8, 12, 24, 48, 72, 96, 144 and 192 hr in clean water, and the same parameters were again evaluated. The results obtained during the exposure to the pesticide as well as during the recovery phase were used to calculate the caloric content in both tissues of A. anguilla. A reduction in energy reserves in the selected tissues was observed after exposure to both fenitrothion concentrations and the caloric content in those animals was lower than in the controls. Most of the metabolic disorders did not persist after allowing recovery in clean water during a week.  相似文献   
537.
538.
This paper considers the implications of the growing recognition of scale challenges, with a particular focus on those concerning the governance of protected areas (PAs), through a critical literature review. Two key scale challenges raised by PAs are considered: (1) the divergence of objectives between resource exploitation and biodiversity conservation; (2) the requirement to fulfil biodiversity conservation obligations. These are explored through a review of a UK marine PA case study which found that even though the state had adopted a controlling role that had created tensions by undermining the authority and livelihoods of some stakeholders, the partnership had been sufficiently strengthened to withstand these tensions through the instrumental development of ??bracing social capital??. Four conclusions for governance research with a particular reference to PA governance are drawn, and it is argued that presumptions based on Habermasian ideals should not constrain governance analyses, in that they should constructively incorporate the instrumental roles of the state.  相似文献   
539.
Boggs, Johnny, Ge Sun, David Jones, and Steven G. McNulty, 2012. Effect of Soils on Water Quantity and Quality in Piedmont Forested Headwater Watersheds of North Carolina. Journal of the American Water Resources Association (JAWRA) 1‐19. DOI: 10.1111/jawr.12001 Abstract: Water quantity and quality data were compared from six headwater watersheds on two distinct soil formations, Carolina Slate Belt (CSB) and Triassic Basins (TB). CSB soils are generally thicker, less erodible, and contain less clay content than soils found in TB. TB generated significantly more discharge/precipitation ratio than CSB (0.33 vs. 0.24) in the 2009 dormant season. In the 2009 growing season, TB generated significantly less discharge/precipitation ratio than CSB (0.02 vs. 0.07). Over the entire monitoring period, differences in discharge/precipitation ratios between CSB and TB were not significantly different (0.17 vs. 0.20, respectively). Storm‐flow rates were significantly higher in TB than CSB in both dormant and growing season. Benthic macroinvertebrate biotic index scores were excellent for all streams. Nutrient concentrations and exports in CSB and TB were within background levels for forests. Low‐stream nitrate and ammonium concentrations and exports suggested that both CSB and TB were nitrogen limited. Soils appear to have had a significant influence on seasonal and storm‐flow generation, but not on long‐term total water yield and water quality under forested conditions. This study indicated that watersheds on TB soils might be more prone to storm‐flow generation than on CSB soils when converted from forest to urban. Future urban growth in the area should consider differences in baseline hydrology and effects of landuse change on water quantity and quality.  相似文献   
540.
A novel design of rapidly equilibrating passive air sampler was deployed at 38 sites across 19 European countries to investigate short-term spatial variability of persistent organic pollutants (POPs). Devices were sealed in airtight containers to eliminate the possibility of contamination during transit and couriered to recipients with deployment instructions. Exposure times of 7days permitted the use of back trajectory analysis to further understand the factors responsible for influencing the large-scale spatial distribution of PCBs, PBDEs, PCNs, PAHs, lindane and HCB. Following sampler harvest, devices were sealed and returned for analysis. Comparison of sequestered levels showed that PAHs exhibited the greatest spatial variability (by a factor of 30) with higher levels often associated with greater population density. In contrast, HCB values were much more uniform, reflecting its well mixed distribution in the atmosphere. Spatial variation was strongly influenced by air mass origin, with lower levels being observed at most sites impacted by maritime air masses.  相似文献   
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