Reconciliation of the Surface Brightness Fluctuations and Type Ia Supernovae Distance Scales

We present Hubble Space Telescope measurements of surface brightness fluctuations (SBF) distances to early-type galaxies that have hosted Type Ia supernovae (SNIa). The agreement in the relative SBF and SNIa multicolor light curve shape and delta-m_15 distances is excellent. There is no systematic scale error with distance, and previous work has shown that SBF and SNIa give consistent ties to the Hubble flow. However, we confirm a systematic offset of about 0.25 mag in the distance zero points of the two methods, and we trace this offset to their respective Cepheid calibrations. SBF has in the past been calibrated with Cepheid distances from the H_0 Key Project team, while SNIa have been calibrated with Cepheid distances from the team composed of Sandage, Saha, and collaborators. When the two methods are calibrated in a consistent way, their distances are in superb agreement. Until the conflict over the ``long'' and ``short'' extragalactic Cepheid distances among many galaxies is resolved, we cannot definitively constrain the Hubble constant to better than about 10%, even leaving aside the additional uncertainty in the distance to the Large Magellanic Cloud, common to both Cepheid scales. However, recent theoretical SBF predictions from stellar population models favor the Key Project Cepheid scale, while the theoretical SNIa calibration lies between the long and short scales. In addition, while the current SBF distance to M31/M32 is in good agreement with the RR Lyrae and red giant branch distances, calibrating SBF with the longer Cepheid scale would introduce a 0.3 mag offset with respect to the RR Lyrae scale.Comment: 13 pages, 3 PostScript figures, LaTeX with AASTeX 5.02 and natbib.sty v7.0 (included). Accepted for publication in The Astrophysical Journa

Nickel and Dimed German Style: The Working Poor in Germany

Using data from the German SOEP, this paper analyses whether there have been (a) any significant changes in poverty rates and poverty intensities before and after the Hartz IV reforms and (b) whether there have been observable changes in the effect of employment in reducing the threat or intensity of poverty. Using multivariate analyses we can find no evidence of increases in poverty rates comparing the time period 2002–2004 with that of 2005–2006. Further we find no change in the effect of employment in reducing the probability and intensity of poverty during this time period. The “working poor” phenomenon in Germany remains relatively small and statistically unchanged by the Hartz reforms.Income distribution, unemployment, poverty

Money for Nothing and Your Chips for Free? The Anatomy of the PC Wage Differential

The role of the computer at the workplace is examined in determining the wage structure in Germany. It is shown that the wage premium attributed to using a computer at work using cross-sectional results for 1997 is 7%. To control for unmeasured individual effects, we use a random effects and fixed effects estimator. The coefficient for computer usage at the workplace did NOT remain stable and although just barely significant, was reduced to mere 1% with individual fixed effects. We conclude that there are no computer usage wage differentials worth speaking of, once one controls adequately for unobserved individual heterogeneity.

International Labor Migration, Economic Growth and Labor Markets – The Current State of Affairs

Even though European labor markets are characterized by high average unemployment, there is a shortage of high-skilled labor, leading many European economists to argue for an immigration policy directed at actively recruiting highly qualified workers from abroad. It has further been argued that an immigration policy that is tailored to attract young and economically successful migrants can alleviate some of the demographic burden associated with an aging population.We embed this discussion into a systematic classification of economic migration research according to its major conceptual and applied questions. The state of theoretical and empirical research on the migration decision, the literature on the economic performance of immigrants and their economic impact is reviewed briefly, proceeding along the lines of a clear conceptual framework. In addition, the paper discusses expectations on future migration flows and the policy options of immigration countries for dealing with these flows.Immigration, European labor markets, Immigration policy

TREX1 is expressed by microglia in normal human brain and increases in regions affected by ischemia

BACKGROUND: Mutations in the three-prime repair exonuclease 1 (TREX1) gene have been associated with neurological diseases, including Retinal Vasculopathy with Cerebral Leukoencephalopathy (RVCL). However, the endogenous expression of TREX1 in human brain has not been studied. METHODS: We produced a rabbit polyclonal antibody (pAb) to TREX1 to characterize TREX1 by Western blotting (WB) of cell lysates from normal controls and subjects carrying an RVCL frame-shift mutation. Dual staining was performed to determine cell types expressing TREX1 in human brain tissue. TREX1 distribution in human brain was further evaluated by immunohistochemical analyses of formalin-fixed, paraffin-embedded samples from normal controls and patients with RVCL and ischemic stroke. RESULTS: After validating the specificity of our anti-TREX1 rabbit pAb, WB analysis was utilized to detect the endogenous wild-type and frame-shift mutant of TREX1 in cell lysates. Dual staining in human brain tissues from patients with RVCL and normal controls localized TREX1 to a subset of microglia and macrophages. Quantification of immunohistochemical staining of the cerebral cortex revealed that TREX1 CONCLUSIONS: TREX1 is expressed by a subset of microglia in normal human brain, often in close proximity to the microvasculature, and increases in the setting of ischemic lesions. These findings suggest a role for TREX