Deponiesickerwässer: Bestimmung zytotoxischer Wirkungen mit dem Pollenschlauchwachstumstest

For risk assessment of environmental samples, rapid and sensitive screening assays for detection of toxic potencies are required. Using leachates from waste deposites in the industrial region Leipzig-Halle (Germany) as an example, we present a simple test procedure suitable for the detection of cytotoxic effects of samples. This method, the pollen tube growth test (PTG), works as follows: Pollen of tobacco (Nicotiana sylvestris Spegazz, & Comes) are suspended in mixtures of growth medium and buffered (pH 6,3 to 7,0) dumping ground leachates. After an 18h-incubation period, growth of pollen tubes is quantified by staining with Alcian blue and subsequent measurment of optical density in a photometer. Sample induced inhibition of pollen tube growth is calculated in relation to controls maintained in pure growth medium. The PTG test shows high sensitivity towards leachates of different chemical composition, and it shows good agreement with assay results from luminescent bacteria tests. We conclude that the PTG test is well suited to assess the hazardous potential of aqueous environmental samples.     

Multilateral energy lending and urban bias in autocracies: promoting fossil fuels

Energy demand is growing rapidly across the world, and international funding agencies like the World Bank have responded by emphasizing energy in their project portfolios. Some of these projects promote the use of fossil fuels, while others support cleaner forms of energy. For climate change mitigation, it is important to understand how international funders decide on the choice between fossil fuels and cleaner sources of energy. Examining the energy funding portfolios of the nine most important international funders for the years 2008-2011, we show that funding for fossil fuels has been concentrated in highly urbanized autocracies. Due to economies of scale, fossil fuels are suitable for generating heat and electricity for densely populated urban areas. Autocratic rulers are subject to urban bias in their policy formulation because the support of concentrated urban constituencies is key to an autocrat’s political survival, and in democracies environmental constituencies can effectively oppose fossil fuel projects.