Oxygen and Sodium Abundances in M13 (NGC 6205) Giants: Linking Globular Cluster Formation Scenarios, Deep Mixing, and Post-RGB Evolution

We present O, Na, and Fe abundances, as well as radial velocities, for 113 red giant branch (RGB) and asymptotic giant branch (AGB) stars in the globular cluster M13. The abundances and velocities are based on spectra obtained with the WIYN-Hydra spectrograph, and the observations range in luminosity from the horizontal branch (HB) to RGB-tip. The results are examined in the context of recent globular cluster formation scenarios. We find that M13 exhibits many key characteristics that suggest its formation and chemical enrichment are well-described by current models. Some of these observations include: the central concentration of O-poor stars, the notable decrease in [O/Fe] (but small increase in [Na/Fe]) with increasing luminosity that affects primarily the "extreme" population, the small fraction of stars with halo-like composition, and the paucity of O-poor AGB stars. In agreement with recent work, we conclude that the most O-poor M13 giants are likely He-enriched and that most (all?) O-poor RGB stars evolve to become extreme HB and AGB-manqu\'e stars. In contrast, the "primordial" and "intermediate" population stars appear to experience standard HB and AGB evolution.Comment: Accepted for publication in The Astrophysical Journal Letters. 18 pages; 3 figures; 1 tabl

A Review of the Literature on Early Warning Systems for Banking Crises

This paper presents a review of alternative methodologies for early detection of banking distress. The methodologies proposed are aimed to the early identification of financial distress for countries without an important recent history of bank failure, but facing an unstable international environment. We evaluate several indicators and methodologies to measure financial distress such as qualitative indicators, the signal extraction approach, limited dependent estimation and finally duration models.

Assessing a decade of interstate bank branching

U.S. banking regulation has historically prohibited the ability of a bank to open or own a branch located outside of its home state, commonly referred to as interstate branching. Only since the passage of the Riegle-Neal Interstate Banking and Branching Efficiency Act (IBBEA) in 1994 have banks have been able to engage in interstate branching, though subject to state restrictions. Despite IBBEA’s removal of branching barriers, it still allowed the states to impose restrictions on the entry of out-of-state branch offices. This article describes the changes in Federal and state interstate branching law since passage of IBBEA and reviews how initial (1994-1997) and evolving (1998-2004) interstate branching laws affect out-of-state branch growth. It concludes that anticompetitive state provisions restricted out-of- state growth when those provisions were more restrictive than the provisions set by IBBEA or by neighboring states.Interstate banking

Value at Risk: Teoría y Aplicaciones

This article describes the Value at Risk concept, popularized during the last ten or fifteen years, presenting applications on stocks, bonds, interest and exchange rate forward contracts, and swaps. We applied asymmetric GARCH methodologies over Chilean stock indexes to enhance our risk evaluation performance. Liquidity adjusted Value at Risk methodologies for individual and multiple asset portfolios are discussed. To conclude, we applied this methodology to evaluate the performance in three Chilean financial institutions.

Un Modelo de Intervención Cambiaria

This article presents an intervention methodology to neutralize fluctuations not associated to fundamentals. The mechanism is based on a conditional heteroskedasticity model GARCH(1,1) for the nominal exchange rate, combined with the Value at Risk concept. The simulation provides the authority with a tool to evaluate whether or not current exchange rate fluctuations can be connected to fundamentals, or if an intervention is required using international reserves to reduce exchange rate pressures. Because of the lower implicit volatilities, the intervention system will help develop the domestic hedging market, and also increase investment and international trade.

Value at Risk Ajustado por Liquidez: Una Aplicación a los Bonos Soberanos Chilenos

International capital market integration together with increasing international volatility, requires an accurate evaluation of the potential losses that portfolio managers may face as a result of international turbulence. Assets with high liquidity standards can be evaluated by the traditional Value at Risk approach (VaR), however, this statistic underestimates the true value of the potential losses when the instrument is not liquid. This paper applies the methodology of liquidity adjusted VaR to the Chilean sovereign bond by incorporating bid-ask spread fluctuations when evaluating a portfolio risk.

Detailed Abundances for a Large Sample of Giant Stars in the Globular Cluster 47 Tucanae (NGC 104)

47 Tuc is an ideal target to study chemical evolution and GC formation in massive more metal-rich GCs since is the closest, massive GC. We present chemical abundances for O, Na, Al, Si, Ca, Ti, Fe, Ni, La, and Eu in 164 red giant branch (RGB) stars in the massive globular cluster 47 Tuc using spectra obtained with both the Hydra multi-fiber spectrograph at the Blanco 4-m telescope and the FLAMES multi-object spectrograph at the Very Large Telescope. We find an average [Fe/H]=--0.79$\pm$0.09 dex, consistent with literature values, as well as over-abundances of alpha-elements ([\alpha/\mbox{Fe}]\sim0.3 dex). The n-capture process elements indicate that 47 Tuc is r-process dominated ([Eu/La]=+0.24), and the light elements O, Na, and Al exhibit star-to-star variations. The Na-O anti-correlation, a signature typically seen in Galactic globular clusters, is present in 47 Tuc, and extends to include a small number of stars with [O/Fe] $\sim$\,--0.5. Additionally, the [O/Na] ratios of our sample reveal that the cluster stars can be separated into three distinct populations. A KS-test demonstrates that the O-poor/Na-rich stars are more centrally concentrated than the O-rich/Na-poor stars. The observed number and radial distribution of 47 Tuc's stellar populations, as distinguished by their light element composition, agrees closely with the results obtained from photometric data. We do not find evidence supporting a strong Na-Al correlation in 47 Tuc, which is consistent with current models of AGB nucleosynthesis yields.Comment: Accepted for publication in The Astrophysical Journa

Non-Destructive Testing of Thermal Resistances for a Single Inclusion in a 2-Dimensional Domain

In this paper we examine the inverse problem of determining the amount of corrosion/disbonding which has occurred on the boundary of a single circular (or nearly circular) inclusion D in a two dimensional domain W using Cauchy data for the steady-state heat equation. We develop an algorithm for reconsructing a function which qunatifies the level of corrosion/disbonding at each point in ¶W. We also address the issue of well-posedness and develop a simple regularization scheme. Then we provide several numerical examples. We shall show a simple procedure for recovering the center of D assuming that the boundary of W and D have the same thermal conductivity