Convective overshooting and the observed width of the main-sequence band

Original paper can be found at: http://www.astrosociety.org/pubs/cs/confseries.html#2--Copyright Astronomical Society of the PacificFor many years we are witnessing a lively debate on the existence and extent of convective overshooting, mainly in the cores of main-sequence stars. This is an important issue, since even a small amount of overshooting increases considerably the mass of the finally hydrogen exhausted core and lengthens the main-sequence lifetime correspondingly

Low noise amplifier for an integrated SQUID electronics operating in liquid nitrogen

A set of components for a direct coupled SQUID electronics was designed and fabricated in silicon semiconductor BiCMOS technology and optimized for liquid nitrogen temperature. The most crucial part, the preamplifier has a white noise level of 0.44nV/√Hz and shows small power dissipation. A complete liquid nitrogen cooled SQUID electronics operates successfully with a HTS dc-SQUID

Ejection velocities of high galactic latitude runaway stars

The definitive version can be found at: http://www.wiley.com/ Copyright Wiley BlackwellWe estimate the distribution of ejection velocities for the known population of high Galactic latitude runaway stars. The initial sample is a collection of 174 early-type stars selected from the literature. The stars are first classified according to their evolutionary status in order to obtain a homogeneous sample of 96 genuine main-sequence stars. Their present velocities and flight times are then estimated using proper motion data from various astrometric catalogues (including Tycho-2, UCAC2 and USNO-B) and the ejection velocities are computed by tracing their orbits back in time, based on a Galactic potential. The potential used is constructed from a mass density model chosen to fit the most recent observational constraints. We find evidence for two different populations of runaway stars: a 'high' velocity population, with a maximum ejection velocity of about 400-500 km s(-1), and a 'low' velocity population, with a maximum ejection velocity of about 300 km s(-1). We argue that the observed limit of 500 km s(-1) and the bimodality of the observed ejection velocity distribution are natural consequences of the so-called Binary Ejection Mechanism. We discuss the connection between the 'high' velocity population and the so-called hypervelocity stars, showing how previously studied hypervelocity stars are consistent with the results obtained. We also find that some stars that were once thought to be best explained as being formed in the halo are compatible with a runaway hypothesis once proper motions are included in the analysis. However, three stars in the selected sample appear to be inconsistent with ejection from the Galactic disc. Possible scenarios are discussed, including a possible formation in the Galactic halo.Peer reviewe

A pre-specified model based on four kallikrein markers in blood improves predictions of adverse pathology and biochemical recurrence after radical prostatectomy

Background: A pre-specified model based on four kallikrein markers in blood, commercially available as 4Kscore, predicts Gleason Grade (GG) 3 + 4 or higher prostate cancer on biopsy. However, sampling error and variation in pathology reporting may miss aggressive disease. Methods: The 4Kscore was measured in cryopreserved blood from 2330 men obtained before prostatectomy at a single institution between 2002 and 2010. Adverse surgical pathology and biochemical recurrence (BCR) were pre-specified to be assessed in all men, biopsy GG 3 + 3, and 3 + 4. Results: Adjusted for established clinical predictors, the 4Kscore was significantly associated with adverse pathology (OR 1.49; 95% CI 1.32, 1.67; p < 0.0001). Adding 4Kscore increased discrimination from (AUC) 0.672 to 0.718 and 0.644 to 0.659 within biopsy GG 3 + 3 and 3 + 4, respectively. Higher 4Kscore was associated with higher risk of BCR (HR 1.16, 95% CI 1.06, 1.26; p = 0.001). Adding 4Kscore improved the prediction of BCR (C-index 0.630–0.660) within GG 3 + 3, but not GG 3 + 4. Conclusions: The 4Kscore can help guide the clinical decision whether additional risk assessment—such as confirmatory biopsy—is needed to decide between active surveillance versus curative therapy. Evidence that the panel could influence management in biopsy GG 3 + 4 is less strong and requires further investigation