PHYSICIAN ASSISTED SUICIDE: NEW DEVELOPMENTS IN THE NETHERLANDS

Until recently, physician assisted suicide was dealt with on the same basis as active voluntary euthanasia in the Netherlands. Over the last years, several cases relating to assistance in suicide of mental patients did raise specific issues, not addressed so far in the debate on euthanasia. One of these cases resulted in a Supreme Court decision. The paper summarizes this decision and comments on it from a legal point of view.     

Biodiversity and the mitigation of climate change through bioenergy: impacts of increased maize cultivation on farmland wildlife

The public promotion of renewable energies is expected to increase the number of biogas plants and stimulate energy crops cultivation (e.g. maize) in Germany. In order to assess the indirect effects of the resulting land‐use changes on biodiversity, we developed six land‐use scenarios and simulated the responses of six farmland wildlife species with the spatially explicit agent‐based model system ALMaSS. The scenarios differed in composition and spatial configuration of arable crops. We implemented scenarios where maize for energy production replaced 15% and 30% of the area covered by other cash crops. Biogas maize farms were either randomly distributed or located within small or large aggregation clusters. The animal species investigated were skylark (Alauda arvensis), grey partridge (Perdix perdix), European brown hare (Lepus europaeus), field vole (Microtus agrestis), a linyphiid spider (Erigone atra) and a carabid beetle (Bembidion lampros). The changes in crop composition had a negative effect on the population sizes of skylark, partridge and hare and a positive effect on the population sizes of spider and beetle and no effect on the population size of vole. An aggregated cultivation of maize amplified these effects for skylark. Species responses to changes in the crop composition were consistent across three differently structured landscapes. Our work suggests that with the compliance to some recommendations, negative effects of biogas‐related land‐use change on the populations of the six representative farmland species can largely be avoided.     

The Recovery of Cytokinins during Extraction and Purification of Clubroot Tissue

Losses of one naturally occurring cytokinin (zeatin) and one synthetic cytoknin (kinetin) were determined during purification of turnips (Brassica compestris) infected by Plasmodiophora brassicae (clubroot). A known amount of zeatin and 8-¹⁴C-kinetin was added after homogenization of plant material in ethanol or water. The commonly used practice to purify the aqueous residues of the homogenate by partitioning with petroleum ether was omitted because of emulsion formation. Losses due to emulsion formation and occlusion of 8-¹⁴C-kinetin into non-water soluble plant material could be prevented by extractionof clubroot tissue with water instead of ethanol. To minimize enzyme activity the aqueous homogenate was kept at 100°C for 5 min. High molecular weight compounds were removed by dialysis against water and the diffusible fraction was partitioned with n-butanol at pH 8.2. It was shown that a rapid evaporation of n-butanol under reduced pressure at high temperature caused less breakdown of 8-¹⁴C-kinetin than prologned treatment at a low temperature. To minimize breakdown to zeatin riboside the butanol fraction was purified further on cation cellulose-phosphate exchanger instead of on strong acid Dowex H⁺. 8-¹⁴C-kinetin was separated from zeatin by column chromatography on Sephadex LH20, and yielded 86% of the amount originally added to a plant homogenate. The zeatin containing fractions were further purified on thin layer chromatography (TLC) silicagel plates and injected into a high pressure liquid chromatograph. A yield of 60% could be estimated from the amount (15 μg) orignally added to 50 g clubroot tissue.