Chiral Symmetry Breaking from Center Vortices

We analyze the creation of near-zero modes from would-be zero modes of various topological charge contributions from classical center vortices in SU(2) lattice gauge theory. We show that colorful spherical vortex and instanton configurations have very similar Dirac eigenmodes and also vortex intersections are able to give rise to a finite density of near-zero modes, leading to chiral symmetry breaking via the Banks-Casher formula. We discuss the influence of the magnetic vortex fluxes on quarks and how center vortices may break chiral symmetry.Comment: Prepared for the 31st International Symposium on Lattice Field Theory - LATTICE 2013, July 29 - August 3 in Mainz, German

Environmental Realpolitik: Joint Implementation and Climate Change

Professor Heller\u27s article discusses why there has been little progress after the Rio Earth Summit in developing the Framework Convention on Climate Change. He argues that, beyond the scientific uncertainties about climate change and its economic impacts, agreement on the legal structure of a comprehensive regime has been hampered by institutional factors. These include: the political discounting of damage to future populations, the diverse risks of global warming in different regions, and the distrust in many nations with market instruments, like taxes or tradable permits, that are favored by many industrial nations dependent on fossil fuels. Resolving these problems will be particularly difficult in multilateral negotiations under the auspices of the United Nations. This is due to the conflation of environmental issues with a broader, contested agenda of North-South issues. Unless this impasse is overcome in the near term, key nations, essential to a successful mitigation regime, may abandon collective solutions and invest in local adaptations to climate change. Heller argues that Joint Implementation (JI), a type of tradable permit system, can help to break this deadlock. However, investment in JIprojects has been slow due to political opposition and to confusion about the nature of an international market in environmental services. The article concludes with an outline for the development of a JI market that does not require a prior multilateral consensus

Eukaryotic translation elongation factor 1A (eEF1A) domain I from S. cerevisiae is required but not sufficient for inter-species complementation

Ethanolamine phosphoglycerol (EPG) is a protein modification attached exclusively to eukaryotic elongation factor 1A (eEF1A). In mammals and plants, EPG is linked to conserved glutamate residues located in eEF1A domains II and III, whereas in the unicellular eukaryote Trypanosoma brucei, only domain III is modified by a single EPG. A biosynthetic precursor of EPG and structural requirements for EPG attachment to T. brucei eEF1A have been reported, but nothing is known about the EPG modifying enzyme(s). By expressing human eEF1A in T. brucei, we now show that EPG attachment to eEF1A is evolutionarily conserved between T. brucei and Homo sapiens. In contrast, S. cerevisiae eEF1A, which has been shown to lack EPG is not modified in T. brucei. Furthermore, we show that eEF1A cannot functionally complement across species when using T. brucei and S. cerevisiae as model organisms. However, functional complementation in yeast can be obtained using eEF1A chimera containing domains II or III from other species. In contrast, yeast domain I is strictly required for functional complementation in S. cerevisia

Making Fiscal Space Happen! Managing Fiscal Policy in a World of Scaled-Up Aid

aid, fiscal policy, low income countries, macroeconomic policy, public financial management