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991.
992.
C W MacMonegle K L Steffey W N Bruce 《Journal of environmental science and health. Part. B》1984,19(1):39-48
The Illinois soybean crop was monitored in 1974 and 1980 for dieldrin, heptachlor, and chlordane residues resulting from the use of these compounds for corn soil insect control in the years before extensive soybean cultivation. Residue levels were compared with past published amounts. Dieldrin residue levels in soybeans declined between 1974 and 1980. Heptachlor and heptachlor epoxide levels remained level between 1974 and 1980. Chlorinated hydrocarbon residues were lower in the southern third of Illinois than for the remainder of the state. 相似文献
993.
J N Seiber 《Journal of environmental science and health. Part. B》1978,13(2):131-148
The loss of carbofuran was studied from rice paddy water treated with a granular formulation of the insecticide, and from ponds filled with drainage from the paddy. The average half-life (t 1/2) for carbofuran loss was 57 hr. Controlled experiments indicated that pH was the predominating factor governing carbofuran loss from water in the environment studied. The loss due to hydrolysis was over 700 times more rapid at pH (t 1/2 = 1.2 hr.) than at pH (t 1/2 = 864 hr.) in buffered deionized water. The average pH of the rice paddy was 8, but diurnal fluctuations of 7 to 9.5 are common in similar environments. Impurities in the water, sunlight, and temperature influence the rate of carbofuran loss but not nearly so much as pH. There was no evidence for significant loss due to evaporation or oxidation. The results have important implications for the duration of the insecticide's activity and the effect on fish within or downstream from treated paddies. 相似文献
994.
In view of their possible involvement in ammonium assimilation in the coral/algal symbiosis, we have purified two distinct glutamate dehydrogenase isoenzymes from the symbiotic dinoflagellate Symbiodinium microadriaticum (Freudenthal) extracted from the staghorn coral Acropora formosa collected from Magnetic Island, North Queensland, Australia, in 1986–1987. An NADPH-specific glutamate dehydrogenase (GDH) displayed biphasic kinetics with respect to ammonium as the variable substrate; at low substrate concentrations the apparent K
m was below 1 mM, whereas at high substrate concentrations the corresponding value was approximately 200 mM. The NADPH-GDH displayed extremely low activity in the direction of glutamate oxidation; together with the kinetic data this suggests a probable role in ammonium assimilation. A second (NADH-specific) GDH was found to have both amination and deamination activities, and presumably functions in vivo in glutamate oxidation. Kinetic constants are reported for both GDH isoenzymes. 相似文献
995.
N. Yusuf 《Die Naturwissenschaften》1976,63(12):576-576
996.
All businesses are continually seeking ways to increase productivity, improve customer satisfaction, reduce waste, and minimize costs. However, small businesses are frequently overlooked in discussions of the implementation of environmental quality improvements in conjunction with management practice improvements. Humes Collision Center incorporated new waste reduction techniques when it expanded its old facilities in 1992, and it was able to achieve the benefits of cost and waste reduction. Humes Collision Center repairs an average of 500 cars annually and is a very small quantity generator of hazardous waste, as defined by the Minnesota Pollution Control Agency. This case study documents the waste minimization and economic benefits at the new autobody repair facility in Hermantown, Minnesota. 相似文献
997.
Ranching the View: Subdivisions versus Agriculture 总被引:2,自引:0,他引:2
998.
999.
S A Soliman N S Ahmed K S el-Gendy A S el-Bakary A H el-Sebae 《Journal of environmental science and health. Part. B》1986,21(5):401-411
The susceptibility of wild mallard ducklings to the delayed neurotoxic effect of the neurotoxic organophosphorus insecticides cyanofenphos and leptophos was evaluated following a daily dosing regimen. Ducklings were treated daily with either cyanofenphos or with leptophos at different dose levels for 90 days, or until they died, or became paralyzed. A control group of ducklings given corn oil at 1 ml/kg daily for 90 days was used for comparison. All treated birds were observed daily for any clinical signs of neurotoxicity during the course of this study. All of the surviving ducklings that were treated with cyanofenphos at 4 mg/kg/day or leptophos at 10 mg/kg/day developed clinical signs of delayed neurotoxicity after 7 to 11 weeks of intoxication. Symptoms included leg weakness, ataxia, severe ataxia and paralysis. The observed clinical signs were confirmed by histological changes found in the spinal cords of the treated birds. These changes were of the type associated with organophosphorus-induced delayed neuropathy (OPIDN). These results demonstrate that wild mallard ducklings are susceptible to OPIDN and this avian species can be used in screening organophosphorus compounds for such effect. 相似文献
1000.
Two different test methods for assessing the toxicity of aminotriazole to Selenastrum capricornutum are compared. Growth medium composition is demonstrated to have a significant effect on the toxicity of aminotriazole. 相似文献