Regulating groundwater use in developing countries: a feasible instrument for public intervention

In many developing countries, groundwater is a common pool resource which is potentially subject to the tragedy of the commons if water extraction is not adequately regulated. However, in these countries, the regulatory infrastructure is often too weak to allow detailed monitoring of individual groundwater extraction. For this reason, classical public intervention instruments, such as consumption fees or tradable quotas, are infeasible. Here we present a theoretical foundation for a new public regulatory instrument that can potentially generate the same efficiency inducing incentives as fees and tradable quotas, but without their information and monitoring requirements. The instrument we propose is a tax based on aggregate extraction, rather than individual extraction measures.Developing countries, groundwater use, moral hazard problems, taxes

Application of processed organic municipal solid waste on agricultural land - a scenario analysis

Source separation, composting and anaerobic digestion, with associated land application, are increasingly being considered as alternative waste management strategies to landfilling and incineration of municipal solid waste (MSW). Environmental life cycle assessments are a useful tool in political decision-making about waste management strategies. However, due to the diversity of processed organic MSW and the situations in which it can be applied, the environmental impacts of land application are very hard to determine by experimental means. In the current study, we used the agroecosystem model Daisy to simulate a range of different scenarios representing different geographical areas, farm and soil types under Danish conditions and legislation. Generally, the application of processed organic MSW resulted in increased emissions compared with the corresponding standard scenarios, but with large differences between scenarios. Emission coefficients for nitrogen leaching to the groundwater ranged from 0.03 to 0.87, while those for nitrogen lost to surface waters through tile drains ranged from 0 to 0.30. Emission coefficients for N2O formation ranged from 0.013 to 0.022 and for ammonia volatilization from 0.016 to 0.11. These estimates are within reasonable range of observed values under similar conditions. Furthermore, a sensitivity analysis showed that the estimates were not very sensitive to the mineralization dynamics of the processed organic MSW. The results show that agroecosystem models can be powerful tools to estimate the environmental impacts of land application of processed MSW under different conditions. Despite this, agroecosystem models have only been used to a very limited degree for this purpose

Just-in-time assembly of cell-cycle protein complexes

Our comparative analysis of eukaryotic cell-cycle complexes reveals that the identity of the periodically expressed subunits differs significantly between organisms and is often mirrored by changes in cell-cycle-dependent phosphorylation of the protein products. This indicates that many different solutions have evolved for just-in-time assembly of the same molecular machines