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The effect of the triazine herbicides Etazine and Bladex on coliform and fecal streptococci groups was studied in Nile river water, Nile water seeded with sewage, and autoclaved Nile water. The results indicate the fecal streptococci were able to persist and multiply in Nile water containing Bladex or Etazine and seeded with sewage. The successive addition of Bladex and Etazine (up to 10 mg/liter) increased its degradation rate and had no inhibitory effect on the bacterial parameters. 相似文献
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Hardworking coworkers: A multilevel cross‐national look at group work hours and work–family conflict
This study investigates the relationship between coworker work hours and perceived work‐to‐family conflict (WFC) in a multinational sample of professional service employees. Building on recent research on the ways in which workgroups influence individual WFC, we demonstrate that the average hours worked by coworkers has a significant relationship to reported WFC independent of an employee's own work hours. Although this finding is universal across the multinational sample, national cultural differences were found to moderate the relationship, such that employees in more collectivist countries are more strongly influenced by average coworker hours than their counterparts in less collectivist countries. The multilevel analysis was conducted using a sample of 7,600 professional service employees in 497 different workgroups across 20 countries. The results provide support for the effect of culture on the relationship between group average hours and perceptions of WFC. We conclude with a discussion of how national culture affects WFC. 相似文献
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Environmental Fluid Mechanics - Understanding the mechanism of dispersion within plants is essential for proper operation of natural and constructed treatment wetlands. Plant deflection induced by... 相似文献
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Hoda I. El-Reefy Taher Sharshar Tarek Elnimr Hussein M. Badran 《Environmental monitoring and assessment》2010,169(1-4):273-284
The sediment compartment has the ability to trap large amounts of radionuclides and to indicate the radiological impact of pollution. The present work shows the results obtained related to the concentrations of 137Cs and natural radionuclides in sediment in the Burullus Lake, Egypt. The average values of 226Ra, 232Th, and 40K in the bottom sediments collected from the east of the Burullus Lake ranged from 10.3 to 21.8 Bq/kg, from 11.9 to 34.4 Bq/kg, and from 268 to 401 Bq/kg, respectively. The study has shown that 40K concentration is nearly uniform throughout the studied area while 226Ra and 232Th are more concentrated in the northeastern shore. Lake sediments showed contamination with 137Cs (2.7–15.9 Bq/kg). The 137Cs sediment activities indicated higher concentrations in the off-shore sites. Concentrations of all γ -ray emitting radionuclides except 40K in water samples were below the detection limits. The 40K sediment–water distribution coefficients of the near-shore samples were higher than the off-shore samples. 相似文献
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Shaalan EA Canyon D Younes MW Abdel-Wahab H Mansour AH 《Environment international》2005,31(8):618-1166
Identification of novel effective mosquitocidal compounds is essential to combat increasing resistance rates, concern for the environment and food safety, the unacceptability of many organophosphates and organochlorines and the high cost of synthetic pyrethroids. An increasing number of researchers are reconsidering botanicals containing active phytochemicals in their efforts to address some of these problems. To be highly competitive and effective, the ideal phytochemical should possess a combination of toxic effects and residual capacity. Acute toxicity is required at doses comparable to some commercial synthetic insecticides while chronic or sub-chronic toxicity is required to produce growth inhibition, developmental toxicity and generational effects. In this article, we review the current state of knowledge on larvicidal plant species, extraction processes, growth and reproduction inhibiting phytochemicals, botanical ovicides, synergistic, additive and antagonistic joint action effects of mixtures, residual capacity, effects on non-target organisms, resistance, screening methodologies, and discuss promising advances made in phytochemical research. 相似文献