From explanation to application: introducing a practice-oriented ecosystem services evaluation (PRESET) model adapted to the context of landscape planning and management

The development and use of the conceptual framework of ecosystem services (ES) has been very successful in supporting the broad diffusion and application of ES within science and policy communities. However, most of the currently proposed interpretations of the framework neither correlate to environmental planning nor to decision-making contexts at the local and regional scale, which is a potential reason for the slow adoption and practice of the ES conceptual framework. This paper proposes a practice-oriented ES evaluation (PRESET) model specifically adapted to the requirements of local and regional planning and decision-making contexts, and discusses its potential benefits and implications for practice. Through the usage of PRESET we suggest making a distinction between ‘offered ES’, ‘utilized ES’, ‘human input’, and ‘ES benefits’ as relevant information for decision-making. Furthermore, we consider it important to link these decision-support categories to different value dimensions relevant in planning and management practice. PRESET provides guidance to inject the ES concept into planning, but needs to be implemented together with concrete assessment methods, indicators and data. The planning strategic benefits of using PRESET include its reference to existing legislative objectives, avoiding the risk that monetized ES values might dominate decision-making, clarification of human contributions, and easier identification of land use conflicts and synergies. Examples are given for offered and utilized ES, as well as for respective evaluation approaches and instruments of implementation.     

The crystal structure of [Fe]-hydrogenase reveals the geometry of the active site

Biological formation and consumption of molecular hydrogen (H2) are catalyzed by hydrogenases, of which three phylogenetically unrelated types are known: [NiFe]-hydrogenases, [FeFe]-hydrogenases, and [Fe]-hydrogenase. We present a crystal structure of [Fe]-hydrogenase at 1.75 angstrom resolution, showing a mononuclear iron coordinated by the sulfur of cysteine 176, two carbon monoxide (CO) molecules, and the sp2-hybridized nitrogen of a 2-pyridinol compound with back-bonding properties similar to those of cyanide. The three-dimensional arrangement of the ligands is similar to that of thiolate, CO, and cyanide ligated to the low-spin iron in binuclear [NiFe]- and [FeFe]-hydrogenases, although the enzymes have evolved independently and the CO and cyanide ligands are not found in any other metalloenzyme. The related iron ligation pattern of hydrogenases exemplifies convergent evolution and presumably plays an essential role in H2 activation. This finding may stimulate the ongoing synthesis of catalysts that could substitute for platinum in applications such as fuel cells.     

Uracil DNA glycosylase activity is dispensable for immunoglobulin class switch

Activation-induced cytidine deaminase (AID) is required for the DNA cleavage step in immunoglobulin class switch recombination (CSR). AID is proposed to deaminate cytosine to generate uracil (U) in either mRNA or DNA. In the second instance, DNA cleavage depends on uracil DNA glycosylase (UNG) for removal of U. Using phosphorylated histone gamma-H2AX focus formation as a marker of DNA cleavage, we found that the UNG inhibitor Ugi did not inhibit DNA cleavage in immunoglobulin heavy chain (IgH) locus during CSR, even though Ugi blocked UNG binding to DNA and strongly inhibited CSR. Strikingly, UNG mutants that had lost the capability of removing U rescued CSR in UNG-/- B cells. These results indicate that UNG is involved in the repair step of CSR yet by an unknown mechanism. The dispensability of U removal in the DNA cleavage step of CSR requires a reconsideration of the model of DNA deamination by AID.