Very Metal-poor Stars in the Outer Galactic Bulge Found by the Apogee Survey

Despite its importance for understanding the nature of early stellar generations and for constraining Galactic bulge formation models, at present little is known about the metal-poor stellar content of the central Milky Way. This is a consequence of the great distances involved and intervening dust obscuration, which challenge optical studies. However, the Apache Point Observatory Galactic Evolution Experiment (APOGEE), a wide-area, multifiber, high-resolution spectroscopic survey within Sloan Digital Sky Survey III (SDSS-III), is exploring the chemistry of all Galactic stellar populations at infrared wavelengths, with particular emphasis on the disk and the bulge. An automated spectral analysis of data on 2,403 giant stars in twelve fields in the bulge obtained during APOGEE commissioning yielded five stars with low metallicity([Fe/H]$\le-1.7$), including two that are very metal-poor [Fe/H]$\sim-2.1$ by bulge standards. Luminosity-based distance estimates place the five stars within the outer bulge, where other 1,246 of the analyzed stars may reside. A manual reanalysis of the spectra verifies the low metallicities, and finds these stars to be enhanced in the $\alpha$-elements O, Mg, and Si without significant $\alpha$-pattern differences with other local halo or metal-weak thick-disk stars of similar metallicity, or even with other more metal-rich bulge stars. While neither the kinematics nor chemistry of these stars can yet definitively determine which, if any, are truly bulge members, rather than denizens of other populations co-located with the bulge, the newly-identified stars reveal that the chemistry of metal-poor stars in the central Galaxy resembles that of metal-weak thick-disk stars at similar metallicity.Comment: 6 pages, 3 figures, 2 table

Purchasing power parity for developing and developed countries: what can we learn from non-stationary panel data models?

The aim of this paper is to apply recently developed panel cointegration techniques proposed by Pedroni (1999, 2004) and generalized by Banerjee and Carrion-i-Silvestre (2006) to examine the robustness of the PPP concept for a sample of 80 developed and developing countries. We find that strong PPP is verified for OECD countries and weak PPP for MENA countries. However in African, Asian, Latin American and Central and Eastern European countries, PPP does not seem relevant to characterize the long-run behavior of the real exchange rate. Further investigations indicate that the nature of the exchange rate regime doesn't condition the validity of PPP which is more easily accepted in countries with high than low inflation

Abundance gradient slopes versus mass in spheroids: predictions by monolithic models

We investigate whether it is possible to explain the wide range of observed gradients in early type galaxies in the framework of monolithic models. To do so, we extend the set of hydrodynamical simulations by Pipino et al. (2008a) by including low-mass ellipticals and spiral (true) bulges. These models satisfy the mass-metallicity and the mass-[alpha/Fe] relations. The typical metallicity gradients predicted by our models have a slope of -0.3 dex per decade variation in radius, consistent with the mean values of several observational samples. However, we also find a few quite massive galaxies in which this slope is -0.5 dex per decade, in agreement with some recent data. In particular, we find a mild dependence from the mass tracers when we transform the stellar abundance gradients into radial variations of the Mg_2 line-strength index, but not in the Mg_b. We conclude that, rather than a mass- slope relation, is more appropriate to speak of an increase in the scatter of the gradient slope with the galactic mass. We can explain such a behaviour with different efficiencies of star formation in the framework of the revised monolithic formation scenario, hence the scatter in the observed gradients should not be used as an evidence of the need of mergers. Indeed, model galaxies that exhibit the steepest gradient slopes are preferentially those with the highest star formation efficiency at that given mass.Comment: Accepted for publication by MNRAS, the paper contains 7 figures and 2 table

K-Sign in retrocaecal appendicitis: a case series

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Variations in position of the vermiform appendix considerably changes clinical findings. Retrocaecal appendicitis presents with slightly different clinical features from those of classical appendicitis associated with a normally sited appendix. K-sign looks for the presence of tenderness on posterior abdominal wall in the retrocaecal and paracolic appendicitis. This is the first case report of this kind in the literature. The K-sign has been named, as a mark of respect, after the region of origin of this sign, Kashmir, so called as "Kashmir Sign". The sign being present in view of inflamed appendix crossing above its non palpable position above iliac crest on the posterior abdominal wall and the tenderness is by irritation of posterior peritoneum Case presentation: The author is reporting a case series of four patients in whom a K-sign, a clinical sign, was elicited and found positive on the posterior abdominal wall for presence of tenderness in a specific area bound by the 12th rib superiorly, spine medially, lateral margin of posterior abdominal wall laterally and iliac crest inferiorly and was found to be present in three retrocaecal and one paracolic appendicitis. Each case had tenderness in this specific area o

Composition dependence of lithium diffusion in lithium silicide: a density functional theory study

The lithiation process of silicon was investigated by using ab initio molecular dynamics. Diffusion coefficients of Li in Li–Si alloys were calculated to be in the range between 2.08×10−9 and 3.53×10−7 cm2 s−1 at room temperature. The results showed that the Li mobility is strongly dependent on the composition of the LixSi alloys. The Li diffusivity in a LixSi alloy can be enhanced by two orders of magnitude when x is increased from 1.0 to 3.75, which can be explained by the instability of the Si network, owing to charge transfer from Li to Si

UBVRI Night sky brightness during sunspot maximum at ESO-Paranal

In this paper we present and discuss for the first time a large data set of UBVRI night sky brightness measurements collected at ESO-Paranal from April 2000 to September 2001. A total of about 3900 images obtained on 174 different nights with FORS1 were analysed using an automatic algorithm specifically designed for this purpose. This led to the construction of an unprecedented database that allowed us to study in detail a number of effects such as differential zodiacal light contamination, airmass dependency, daily solar activity and moonlight contribution. Particular care was devoted to the investigation of short time scale variations and micro-auroral events. The typical dark time night sky brightness values found for Paranal are similar to those reported for other astronomical dark sites at a similar solar cycle phase. The zenith-corrected values averaged over the whole period are 22.3, 22.6, 21.6 20.9 and 19.7 mag arcsec-2 in U, B, V, R and I respectively. In particular, there is no evidence of light pollution either in the broadband photometry or in the high-airmass spectra we have analysed. Finally, possible applications for the exposure time calculators are discussed.Comment: Accepted for publication in A&A; 22 pages, 22 figures. Paper with full resolution figures available at http://www.eso.org/~fpatat/science/skybright/paperII.ps.g

医師が患者から受ける暴力被害とその心理的影響

Objectives: To determine the incidence rate of work-related aggression and violence (WRAV) against doctors and investigate risk factors and psychological influences of WRAV doctors. Methods: We sent a self-administered questionnaire on WRAV committed by patients and their associates to 1,148 doctors in Nara Prefecture, Japan. We calculated the incidence rate of WRAV using the number of incidents encountered during the previous 12 mo and the doctor's average weekly working hours. Risk factors for the incidence WRAV were analyzed by Poisson regression, and the influence of WRAV on the symptoms of post-traumatic stress disorder (PTSD) was evaluated by multiple logistic regression analysis. Results: A total of 758 (66.0%) doctors returned the questionnaire. The incidence rate of WRAV was 0.20 [95% CI: 0.17-0.24]×10-3 per practice hour. Adjusted incidence rate ratios of WRAV were significantly increased among doctors 1) with a shorter career (11.0; 95% CI: 5.0-24.2), 2) working in a region with the lowest average taxable income (1.6; 1.1-2.4), and 3) whose specialties were dermatology (3.8; 2.3-6.3), psychiatry (2.7; 1.3-5.6) and ophthalmology (1.9; 1.2-3.2). Of 289 subjects who had encountered WRAV at least once during their career, 26 doctors (8.2%) had symptoms suggestive of PTSD due to the most severe incident. Conclusions: Doctors encountered WRAV at an incidence rate of 0.20×10-3 per practice hour, and some of them might develop PTSD. Countermeasures are required to maintain sound health and safe workplaces for doctors.博士（医学）・乙第1292号・平成24年5月28日Copyright © 2011 by the Japan Society for Occupational Healt