The Multiwavelength Survey by Yale-Chile (MUSYC): Deep Medium-Band optical imaging and high quality 32-band photometric redshifts in the ECDF-S

We present deep optical 18-medium-band photometry from the Subaru telescope over the ~30' x 30' Extended Chandra Deep Field-South (ECDF-S), as part of the Multiwavelength Survey by Yale-Chile (MUSYC). This field has a wealth of ground- and space-based ancillary data, and contains the GOODS-South field and the Hubble Ultra Deep Field. We combine the Subaru imaging with existing UBVRIzJHK and Spitzer IRAC images to create a uniform catalog. Detecting sources in the MUSYC BVR image we find ~40,000 galaxies with R_AB<25.3, the median 5 sigma limit of the 18 medium bands. Photometric redshifts are determined using the EAZY code and compared to ~2000 spectroscopic redshifts in this field. The medium band filters provide very accurate redshifts for the (bright) subset of galaxies with spectroscopic redshifts, particularly at 0.1 < z 3.5. For 0.1 < z < 1.2, we find a 1 sigma scatter in \Delta z/(1+z) of 0.007, similar to results obtained with a similar filter set in the COSMOS field. As a demonstration of the data quality, we show that the red sequence and blue cloud can be cleanly identified in rest-frame color-magnitude diagrams at 0.1 < z < 1.2. We find that ~20% of the red-sequence-galaxies show evidence of dust-emission at longer rest-frame wavelengths. The reduced images, photometric catalog, and photometric redshifts are provided through the public MUSYC website.Comment: 19 pages, 14 image

Black-Hole Mass and Growth Rate at z~4.8: A Short Episode of Fast Growth Followed by Short Duty Cycle Activity

We present new Gemini-North/NIRI and VLT/SINFONI H-band spectroscopy for a flux limited sample of 40 z~4.8 active galactic nuclei, selected from the Sloan Digital Sky Survey. The sample probably contains the most massive active black holes (BHs) at this redshift and spans a broad range in bolometric luminosity, 2.7x10^46< L_bol < 2.4x10^47 erg/sec. The high-quality observations and the accurate fitting of the MgII(2800A) line, enable us to study, systematically, the distribution of BH mass (M_BH) and normalized accretion rate (L/L_Edd) at z~4.8. We find that 10^8 < M_BH < 6.6x10^9 M_sun, with a median of ~8.4x10^8 M_sun. We also find that 0.2 < L/L_Edd < 3.9 with a median of ~0.6. Most of these sources had enough time to grow to their observed mass at z~4.8 from z=20, assuming a range of seed BH masses, with ~40% that are small enough to be stellar remnants. Compared to previously studied samples at z~2.4 and 3.3, the masses of the z~4.8 BHs are typically lower by ~0.5 dex. and their L/L_Edd is higher by a similar factor. The new z~4.8 sample can be considered as the progenitor population of the most massive BHs at z~2.4 and 3.3. Such an evolutionary interpretation requires that the growth of the BHs from z~4.8 to z~3.3 and z~2.4 proceeds with short duty cycles, of about 10-20%, depending on the particular growth scenario.Comment: 14 pages and 8 figures. Accepted for publication in Ap

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo

Assessment of the Mineral Composition and the Selected Physicochemical Parameters of Dietary Supplements Containing Green Tea Extracts

Our aim was to assess the mineral composition as well as the physicochemical quality of green tea-based dietary supplements (capsules and tablets) with respect to average weight, size and shape, friability, breaking force and disintegration time. Products were analysed by flame atomic absorption spectrometry for Ca, K, Mg, Na, Cr, Cu, Fe, Zn, Mn, Pb and Cd. Approximately 60% of the analysed supplements met the requirements of European and Polish regulations. The dietary supplements passed weight variation tests, but not all products had compliant capsule sizes. One product in tablet form failed the friability test, and eleven dietary supplements in tablet form failed the disintegration test. The supplements were characterised by a varied elemental composition, with the highest values found for Ca, Fe, Zn and Mn. The recommended daily allowance realisation for Fe and Zn in two dietary supplements (capsule form) exceeded 100%. As a result of the estimation of the monthly intake of toxic metals, it was concluded that the tested products do not pose a risk to consumer health. Significant relationships (p &lt; 0.001) were found for K, Mg, Na, Cu, Fe, Mn and Zn. The application of factor and cluster analyses allowed the verification of the similarity of green tea extracts contained in dietary supplements to the natural raw material, green tea leaves, used as a reference material

Bacterial Expression, Purification and In Vitro Phosphorylation of Full-Length Ribosomal S6 Kinase 2 (RSK2)

Ribosomal S6 kinases (RSK) play important roles in cell signaling through the mitogen-activated protein kinase (MAPK) pathway. Each of the four RSK isoforms (RSK1-4) is a single polypeptide chain containing two kinase domains connected by a linker sequence with regulatory phosphorylation sites. Here, we demonstrate that full-length RSK2 - which is implicated in several types of cancer, and which is linked to the genetic Coffin-Lowry syndrome - can be overexpressed with high yields in Escherichia coli as a fusion with maltose binding protein (MBP), and can be purified to homogeneity after proteolytic removal of MBP by affinity and size-exclusion chromatography. The purified protein can be fully activated in vitro by phosphorylation with protein kinases ERK2 and PDK1. Compared to full-length RSK2 purified from insect host cells, the bacterially expressed and phosphorylated murine RSK2 shows the same levels of catalytic activity after phosphorylation, and sensitivity to inhibition by RSK-specific inhibitor SL0101. Interestingly, we detect low levels of phosphorylation in the nascent RSK2 on Ser386, owing to autocatalysis by the C-terminal domain, independent of ERK. This observation has implications for in vivo signaling, as it suggests that full activation of RSK2 by PDK1 alone is possible, circumventing at least in some cases the requirement for ERK