Female oviposition-site preference and egg hatching success in the damselfly Calopteryx splendens xanthostoma

By removing males and controlling the rate of water flow past oviposition patches in an experimental area, we showed that female Calopteryx splendens xanthostoma preferred to oviposit in fast flowing water rather than slow flowing water. A series of manipulations revealed the fitness benefits to females for this preference: eggs placed in fast-flowing water developed significantly faster and showed significantly lower mortality than eggs placed in slow-flowing water. A major factor determining this difference was the deposition and growth of encrusting algae which prevented the successful hatching of eggs in slow-flowing water.     

Stabilization of Pb- and Cu-contaminated soil using coal fly ash and peat

The stabilization of metal contaminated soil is being tested as an alternative remediation method to landfilling. An evaluation of the changes in Cu and Pb mobility and bioavailability in soil induced by the addition of coal fly ash and natural organic matter (peat) revealed that the amount of leached Cu decreased by 98.2% and Pb by 99.9%, as assessed by a batch test. Metal leaching from the treated soil was lower by two orders of magnitude compared to the untreated soil in the field lysimeters. A possible formation of mineral Cu- and Pb-bearing phases and active surface with oxides were identified by chemical equilibrium calculations. Low metal leaching during a two-year observation period, increased seed germination rate, reduced metal accumulation in plant shoots, and decreased toxicity to plants and bacteria, thereby demonstrating this stabilization method to be a promising technique for in situ remediation of Cu and Pb contaminated soil.     

Experimental research on race and sex discrimination: The record and the prospects

Research in industry regarding race and sex access discrimination is reviewed. Review of sex discrimination research suggests that negative access discrimination exists for female applicants when the position is male-stereotyped and positive access discrimination exists when it is female-stereotyped. Results on race discrimination are few in number with mixed results, some showing reverse discrimination and others showing discrimination against blacks. More complex studies examining interactions between race and sex also provide mixed results. Recent evidence, which suggests that selection decisions are much more complex than have been studied, may account for the conflicting findings. Future research with more imaginative and complex designs and larger sample sizes is needed. Research designs should be selected to facilitate better measurement of the effects of civil rights law enforcement.     

Radon as a naturally occurring tracer for the assessment of residual NAPL contamination of aquifers

The noble gas radon has a strong affinity to non-aqueous phase-liquids (NAPLs). That property makes it applicable as naturally occurring partitioning tracer for assessing residual NAPL contamination of aquifers. In a NAPL contaminated aquifer, radon dissolved in the groundwater partitions preferably into the NAPL. The magnitude of the resulting radon deficit in the groundwater depends on the NAPL-specific radon partition coefficient and on the NAPL saturation of the pore space. Hence, if the partition coefficient is known, the NAPL saturation is attainable by determination of the radon deficit. After a concise discussion of theoretical aspects regarding radon partitioning into NAPL, related experimental data and results of a field investigation are presented. Aim of the laboratory experiments was the determination of radon partition coefficients of multi-component NAPLs of environmental concern. The on-site activities were carried out in order to confirm the applicability of the "radon method" under field conditions.