基于便携式生物传感器设备的转基因现场快速分析研究

现场快速检验(point of care test,POCT)是实现转基因基层监管必要的技术手段,在转基因成分检测中发挥着重要作用.生物传感器为转基因成分简单、快速和低成本定量分析提供了一个可行的技术方案.目前大量的生物传感器研究还处于方法学研究阶段,研究者需要着重将生物传感器技术与分析设备集成,开发小型化的便携式检测...     

Cropping Systems in Eastern Europe: Past,Present, and Future

SUMMARY

The evolution of cropping systems in Eastern Europe has been a long and gradual process. The objective of this paper is to provide a comprehensive review of the cropping systems in Eastern Europe before World War II, the present cropping systems, and speculate on the future systems. Before World War II, the crop-long term fallow, the grass-crop, and the field rotation were the prominent cropping systems. Crop rotations were adopted in the 16th–17th century and various modifications of the ‘Norfolk’ and the ‘crop-grass’ rotation systems were used. Cash cropping, industrial cropping, and monoculture were extensively used after World War II. Major political, social, and economic changes took place in Eastern Europe after the dissolution of the Soviet Union. Nationalized land was returned to rightful owners. The new owners, however, lacked the skills and financial resources for intensive crop production and this has resulted in drastic reductions in crop yields. Integrated crop production seems to be the most viable option for the East European countries because organic or biological cropping is financially too demanding. Considerable efforts are being made to design new cropping systems which emphasize reductions in mineral fertilizers and pesticides, and conservation tillage. Eastern Europe may become important exporters of agricultural commodities by the year 2020.