Effect of exposure history on microbial herbicide degradation in an aerobic aquifer affected by a point source

The effects of in situ exposure to low concentrations (micrograms per liter) of herbicides on aerobic degradation of herbicides in aquifers were studied by laboratory batch experiments. Aquifer material and groundwater were collected from a point source with known exposure histories to the herbicides mecoprop (MCPP), dichlorprop, BAM, bentazone, isoproturon, and DNOC. Degradation of the phenoxy acids, mecoprop and dichlorprop, was observed in five of six sampling points from within the plume. Mecoprop was mineralized, and up to 70% was recovered as 14CO2. DNOC was degraded in only two of six sampling points from within the plume, and neither BAM, bentazone, nor isoproturon was degraded in any sampling point. A linear correlation (R2 > or = 0.83) between pre-exposure and amount of herbicide degraded within 50 days was observed for the phenoxy acids, mecoprop and dichlorprop. An improved model fit was obtained from using Monod degradation kinetics compared to zero- and first-order degradation kinetics. An exponential correlation (R2 > or = 0.85) was also found between numbers of specific phenoxy acid degrading bacteria and pre-exposure. Combination of these results strongly indicates that the low concentration exposure to phenoxy acids in the aquifer resulted in the presence of acclimated microbial communities, illustrated bythe elevated numbers of specific degraders as well as the enhanced degradation capability. The findings support application of natural attenuation to remediate aerobic aquifers contaminated by phenoxy acids from point sources.     

LC–MS/MS with atmospheric pressure chemical ionisation to study the effect of UV treatment on the formation of vitamin D3 and sterols in plants

Some plant species are known to cause calcium intoxification in grazing animals. This has been attributed to the presence of vitamin D₃-like activity. However, research into the presence of vitamin D₃ in plants has been limited. One reason for this may be limitations in the analytical methods available for unambiguous detection and quantification of vitamin D₃. This paper presents a new method for determining vitamin D₃ and its sterol precursors. The method is based on saponification and extraction followed by solid phase clean-up of the compounds from plant leaves and detection by APCI-MS. Recoveries ranged from 101% to 114% and precision from 3% to 12%. Detection limits were 2–8 ng/g fresh weight for the substances tested. In a pilot study we found that Solanum glaucohyllum Desf. and Solanum lycopersicum L. produced vitamin D₃ after UV-treatment. The preliminary results presented suggest that vitamin D₃ formation in plants is dependent on light exposure.     

The Evolution of the Design Management Field: A Journal Perspective

Based on a literature survey of the development of concepts supplemented by a selective literature review for the years 2000 to 2010, this article aims to trace the dynamic development of the field of design management – a cross‐disciplinary research field seeking to establish itself in its own right. The framework of this research is evolutionary theory, and our analysis are based on two prime design management journals followed by a comparative review two adjunct journals The Design Journal and Creativity and Innovation Management. The challenge is to avoid being overwhelmed by the established paradigms and logics dominating the field of management research. As far as this limited study of adjunct journals indicates, design management as a field of study has not yet been able to acquire attention outside the design research community.     

基于智能电网构建的欧洲可再生能源电力系统现状和前景展望

可再生能源在欧盟未来的能源框架中扮演着重要角色。到2020年,在欧盟总的能源消耗量中,预期20%将来自可再生能源,并且能效将提高20%。智能电网将是未来电力系统接纳大规模可再生能源发电并网的基石。文中介绍了欧洲的可再生能源开发现状和规划以及能源政策,并讨论了欧盟在智能电网相关技术方面的研发进展。丹麦是欧盟国家中可再生能源使用和相关关键技术研发的领跑者,文中重点以其为例进行介绍和阐述。