Grants and debt forgiveness in Africa : a descriptive analysis

The authors analyze the effects of bilateral debt forgiveness on 32 low-income countries in Africa (1984-93). Asking whether it makes a difference for recipient countries to receive pure grants rather that official development assistance (ODA) debt relief, they focus on how one form of aid or the other affects the countries'import capacity. They conclude that: a) grants allowed recipient countries to significantly expand their import capacity for 1984-93 as grants and import capacity have been increasing since 1984. But the increasing share of concessional lending and debt relief in recent years has not allowed these countries to reduce total indebtedness nor solve debt overhang. b) the biggest recipients of debt relief also received the lion's share of the pure grants increase. Debt forgiveness and pure grants were allocated not entirely consistent with standard economic hierarchies. c) bilateral ODA debt forgiveness appears to be neutral in the sense of not having any significant impact on import capacity. During 1989-93, multilateral lending replaced the bilateral lending decrease caused by an increase in grants. d) private creditors have typically withdrawn money as grants increased. And debt relief has had a crowding-out effect on new lending. Bilateral donors are switching their development finance to Africa from concessional and non-concessional lending to a combination of pure grants and ODA relief.Payment Systems&Infrastructure,Banks&Banking Reform,Public Sector Economics&Finance,Municipal Financial Management,Public&Municipal Finance,Urban Economics,Municipal Financial Management,Banks&Banking Reform,Public Sector Economics&Finance,Public&Municipal Finance

Mixed action computations on fine dynamical lattices

We report on our first experiences in simulating Neuberger valence fermions on CLS $N_f=2$ configurations with light sea quark masses and small lattice spacings. Valence quark masses are considered that allow to explore the matching to (partially quenched) chiral perturbation theory both in the $\epsilon$- and $p$-regimes. The setup is discussed, and first results are presented for spectral observables.Comment: 7 pages. Presented at the XXVII International Symposium on Lattice Field Theory, July 26-31, 2009, Peking University, Beijing, Chin

Dust Around R Coronae Borealis Stars. I. Spitzer/Infrared Spectrograph Observations

Spitzer/infrared spectrograph (IRS) spectra from 5 to 37 mu m for a complete sample of 31 R Coronae Borealis stars (RCBs) are presented. These spectra are combined with optical and near-infrared photometry of each RCB at maximum light to compile a spectral energy distribution (SED). The SEDs are fitted with blackbody flux distributions and estimates are made of the ratio of the infrared flux from circumstellar dust to the flux emitted by the star. Comparisons for 29 of the 31 stars are made with the Infrared Astronomical Satellite (IRAS) fluxes from three decades earlier: Spitzer and IRAS fluxes at 12 mu m and 25 mu m are essentially equal for all but a minority of the sample. For this minority, the IRAS to Spitzer flux ratio exceeds a factor of three. The outliers are suggested to be stars where formation of a dust cloud or dust puff is a rare event. A single puff ejected prior to the IRAS observations may have been reobserved by Spitzer as a cooler puff at a greater distance from the RCB. RCBs which experience more frequent optical declines have, in general, a circumstellar environment containing puffs subtending a larger solid angle at the star and a quasi-constant infrared flux. Yet, the estimated subtended solid angles and the blackbody temperatures of the dust show a systematic evolution to lower solid angles and cooler temperatures in the interval between IRAS and Spitzer. Dust emission by these RCBs and those in the LMC is similar in terms of total 24 mu m luminosity and [8.0]-[24.0] color index.Spanish Ministry of Science and Innovation (MICINN) AYA-2007-64748NASA GO 50212, 1407Robert A. Welch Foundation of Houston, Texas F-634McDonald Observator

High-Resolution Optical Spectroscopy of DY Cen: Diffuse Interstellar Bands in a Proto-Fullerene Circumstellar Environment?

We search high-resolution and high-quality VLT/UVES optical spectra of the hot R Coronae Borealis star DY Cen for electronic transitions of the C-60 molecule and diffuse interstellar bands (DIBs). We report the non-detection of the strongest C-60 electronic transitions (e. g., those at similar to 3760, 3980, and 4024 angstrom). The absence of C-60 absorption bands may support recent laboratory results, which show that the similar to 7.0, 8.5, 17.4, and 18.8 mu m emission features seen in DY Cen-and other similar objects with polycyclic-aromatic-hydrocarbon-like dominated IR spectra-are attributable to proto-fullerenes or fullerene precursors rather than to C-60. DIBs toward DY Cen are normal for its reddening; the only exception is the DIB at 6284 angstrom (possibly also the 7223 angstrom DIB) which is found to be unusually strong. We also report the detection of a new broad (FWHM similar to 2 angstrom) and unidentified feature centered at similar to 4000 angstrom. We suggest that this new band may be related to the circumstellar proto-fullerenes seen at infrared wavelengths.Director's Discretionary Time (DDT) program 284.D-5048Spanish Ministry of Economy and Competitiveness AYA-2011-27754Robert A. Welch Foundation of Houston, Texas F-634McDonald Observator