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641.
Bhavan PS Geraldine P 《Journal of environmental biology / Academy of Environmental Biology, India》2002,23(2):157-162
The present study was performed to investigate the toxic impact of carbaryl on biochemical metabolism in the hemolymph, brain, hepatopancreas, gills and muscle of intermoult juveniles of the economically important prawn, Macrobrachium malcolmsonii. The concentration of glutathione S-transferase (GST) was found to be higher in test prawns when compared with controls. This suggests that a mechanism of detoxification was in operation to neutralise carbaryl toxicity. However, the toxic effect of carbaryl was not fully neutralised, and hence, alterations were recorded in basic biochemical metabolism of test prawns. The concentration of acetylcholinestrase (AchE) was found to be lower in test prawns than that of controls. Carbaryl toxicity resulted in utilisation of major biochemical constituents, such as total carbohydrate, glycogen, protein and lipid to generate required energy as an attempt to withstand the toxic stress. Glycogenolysis resulted in elevation of total free sugar level in the hemolymph of test prawns. While proteolysis led to elevation of total free amino acid level in test prawns. The content of total lipid have also been found lower in test prawns than that of controls. This suggests that carbaryl toxicity resulted in severe energy crises in test prawns. In the present study, toxic effects of carbaryl impair basic metabolic functions and hence pose a threat to the life of M. malcolmsonii. 相似文献
642.
Andrew P.Zemek 《生态毒理学报》2003,25(1):53-55
在联合国环境规划署、世界银行集团和采矿、矿产和可持续发展计划( MMSD)一起组织的关注金融机构在为采矿项目提供资金方面作用的研讨会之前,对采矿业投资过程中的关键决策者进行了采访.本文提供了给采矿业提供投资的金融机构对当前环境状态的印象. 相似文献
643.
Urban Geochemistry: A Multimedia and Multielement Survey of a Small Town in Northern Europe 总被引:7,自引:0,他引:7
The concentrations and distributions of chemical elements (Ag, Al, As, Au, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sc, Se, Sr, Te, Th, Ti, Tl, U, V, W and Zn) were studied in till, humus and urban soil in Jakobstad, a small town (20,000 inhabitants) in W. Finland. The analyses were performed with ICP-MS after aqua regia leaching of till (n = 37), urban topsoil (n = 32) and subsoil (n = 32), and HNO3 leaching of humus (n = 37). The till and humus samples, collected at the same sites, were divided into urban and rural samples. The urban till was not significantly enriched in metals. In contrast, a majority of the elements occurred in higher concentrations in the urban than the rural humus samples. Statistical and spatial interpretations of the humus data revealed that traffic (Pb, V and Ni), metal industry (Pb, Zn, Bi, Sb and Cr), an abandoned shooting range (Pb and Sb) and other sources contribute to higher metal levels in the urban humus. The urban soil samples were collected at parks, yards, abandoned industrial sites, roadsides, etc. The topsoil samples were enriched in most elements, also by elements not enriched in the urban humus (e.g. Cd). At several sites, the concentrations far exceeded the limit concentrations for contaminated soils in Finland. A large variety of sources were identified or indicated. 相似文献
644.
Uranium Accumulation of Crop Plants Enhanced by Citric Acid 总被引:6,自引:0,他引:6
Citric acid was applied to soil to enhance U accumulation in four crop plants. While the highest enhanced U accumulation of
aboveground tissues (a.c. 2000 mg kg−1 dry weight) occurred in the leaves of Indian mustard (Brassica juncea), the highest enhanced U accumulation of roots (a.c. 3500 mg kg−1 dry weight) occurred in canola (Brassica napus var. napus). Uranium translocation among tissues of test plants is in the relation of roots>shoots ≅ leaves. The flowers of sunflower
(Helianthus annuus) contained similar or higher U concentrations than those found in shoots, but concentrations in seeds are close to zero.
In conclusion, Indian mustard is recommended as a potential species for phytoextraction for U-contaminated soil due to its
high U accumulation of aboveground biomass (a.c. 2200 μg per plant). There is no evidence that two types of soils cause a
significant difference of the enhanced U accumulation (p<0.05). Results, however, indicate that additional citric acid may result in downward U migration that may contaminate groundwater.
Speciation of U that is taken up by plants is also discussed in the end. 相似文献
645.
微型、小型和中型企业创造了巴西的主要财富,但是这些企业却难以遵守环境法律,在这种情况下,清洁生产意义重大;它使得应用简便、廉价、持续的解决方案帮助小企业减少其环境影响、降低雇员的健康和安全风险成为可能,清洁生产战略通过把中心放在减少浪费和损耗上而改善环境条件,在实施清洁生产措施的同时,对一些措施的环境效率和经济可行性进行评估,采用最多的是良好的内务管理等简便措施,良好的内务管理包括业务参数的最优化、程序的标准化、改进买卖系统以及维护、信息和培训程序的最优化,巴西良好的内务管理战略所占的优势表明了对低成本解决方案的优先选择。 相似文献
646.
Escalante M Rodríguez-Malaver AJ Araujo E González AM Rojas OJ Peñaloza N Bullón J Lara MA Dmitrieva N Pérez-Pérez E 《Journal of environmental biology / Academy of Environmental Biology, India》2005,26(4):709-718
One of the limitations of the biodegradation of hydrophobic chemical compounds, like lignins, is their low solubility in the aqueous solution where this process takes place. To resolve this problem, surfactants have been used to improve the solubility of these hydrophobic compounds. In this investigation, we studied the effect of surfactants (anionic, cationic, and non-ionic) on the treatment of Kraft black liquor with Fenton's reagent. In the Fenton reaction, H2O2 (two different concentrations, 10 mM and 20 mM), FeCl2 (1 mM) and surfactant solution (10%) were used. Black liquor degradation was determined by UV/Visible spectrophotometry and by measuring phenolic groups. In the presence of Fenton's reagent, the optimum conditions for the oxidative degradation of black liquor were 10 mM H2O2, 1 microL of 10% solution of anionic surfactant (SDS). The importance of the use of surfactants for preparing black liquor for subsequent Fenton's reagent-mediated degradation was discussed. 相似文献
647.
Rare royal families in honeybees, Apis mellifera 总被引:1,自引:0,他引:1
Moritz RF Lattorff HM Neumann P Kraus FB Radloff SE Hepburn HR 《Die Naturwissenschaften》2005,92(10):488-491
The queen is the dominant female in the honeybee colony, Apis mellifera, and controls reproduction. Queen larvae are selected by the workers and are fed a special diet (royal jelly), which determines
caste. Because queens mate with many males a large number of subfamilies coexist in the colony. As a consequence, there is
a considerable potential for conflict among the subfamilies over queen rearing. Here we show that honeybee queens are not
reared at random but are preferentially reared from rare “royal” subfamilies, which have extremely low frequencies in the
colony's worker force but a high frequency in the queens reared. 相似文献
648.
Nearly 91% of organic pollutants in Hong Kong leachate could be effectively removed by the UASB(upflow anaerobic sludge blanket)process followed by the fenton coagulation.The COD(chemical oxygen demand)of leachate was lowered from an average of 5620 mg/L to 1910 mg/L after the UASB treatment at 37℃,and was further lowered to 513 mg/L after fenton coagulation.The remaining refractory residues could be further removed by plotochemical oxidation with the addition of H2O2.The BOD/COD ratio was greatly increased from 0.062 to 0.142,indicating the biodegradability of organic residues was improved.The photochemical oxidation for the fenton-coagulation supernatant was most effective at pH3-4,with the addition of 800 mg/L of H2O2,and UV radiation time of 30 minutes.The final effluent contained only 148 mg/L of COD,21 mg/L of BOD(biochemical oxygen demand)and 56 mg/L of TOC (total organic carbon). 相似文献
649.
Coeloides bostrichorum Giraud parasitoids (Hymenoptera: Braconidae) attack late larval stages of various bark beetle species breeding in spruce. Volatile compounds collected from Norway spruce (Picea abies) infested by Ips typographus L. (Coleoptera: Scolytidae) were analysed by coupled gas chromatography-mass spectrometry (GC-MS) and GC-electroantennographic detection (GC-EAD). Monoterpene hydrocarbons are the predominant volatile compounds of fresh Norway spruce, while the presence of oxygenated monoterpenes indicates damaged trees. Between one and eight EAD-active oxygenated monoterpenes were used, in amounts reflecting their natural abundance in spruce trees containing bark beetle larvae, to prepare five synthetic baits which were tested in wind tunnel bioassays. Odour samples collected from spruce logs containing the preferred host stage were attractive, while similar samples from uninfested logs failed to elicit any flight activity. However, when a four- or an eight-component synthetic bait was added to volatiles collected from uninfested spruce logs, this combination was as attractive as volatiles collected from infested spruce logs. 相似文献
650.
<正> 关于地表常温条件下水和岩石之间的关系、水的化学成分及湖泊蒸发沉积物的形成过程等问题是目前广泛引起注意的问题。本报告所涉及的具体内容局限于地表条件下的湖相沉积。 湖相沉积,以美国大盐湖为例,它涉及到犹他州、科罗拉多州与怀俄明州的古湖泊(图1),湖 相似文献