This study is the first report on the numerous culturable, unculturable and unclassified bacteria in the fairy ring of T. matsutake using the pyrosequencing method.
We present our statistical analysis of the connection between active galactic nuclei (AGN) variability and physical properties of the central supermassive black hole (SMBH). We constructed optical light curves using data from the QUEST-La Silla AGN variability survey. To model the variability, we used the structure function, among the excess variance and the amplitude from Damp Random Walk (DRW) modeling. For the measurement of SMBH physical properties, we used public spectra from the Sloan Digital Sky Survey (SDSS). Our analysis is based on an original sample of 2345 sources detected in both SDSS and QUEST-La Silla. For 1473 of these sources we could perform a proper measurement of the spectral and variability properties, and 1348 of these sources were classified as variable (91.5%). We found that the amplitude of the variability (A) depends solely on the rest frame emission wavelength and the Eddington ratio, where A anti-correlates with both λ rest and L/L Edd . This suggests that AGN variability does not evolve over cosmic time, and its amplitude is inversely related to the accretion rate. We found that the logarithmic gradient of the variability (γ) does not correlate significantly with any SMBH physical parameter, since there is no statistically significant linear regression model with an absolute value of the slope higher than 0.1. Finally, we found that the general distribution of γ measured for our sample differs from the distribution of γ obtained for light curves simulated from a DRW process. For 20.6% of the variable sources in our sample, a DRW model is not appropriate to describe the variability, since γ differs considerably from the expected value of 0.5.
Screening for tyrosinase (TYR) inhibitors potentially useful for control of skin pigmentation has been hampered by the limited availability of human TYR. To overcome this hurdle, we have established human embryonic kidney (HEK293)-TYR cells that constitutively express human TYR. In the current study, we assayed human TYR inhibition activities of 50 plant extracts using the lysates of transformed HEK293-TYR cells. The strongest inhibition of human TYR was shown by the extract of Vaccinium bracteatum Thunberg, followed by the extract of Morus bombycis Koidzumi. The former extract did not inhibit mushroom TYR activity whereas significant inhibition was observed with the latter extract, demonstrating the importance of using human TYR in the screening for human TYR inhibitors. Upon liquid-liquid partitioning of the extract from V. bracteatum, the active constituents were enriched in the ethyl acetate fraction, and the subsequent preparatory thin-layer chromatography identified p-coumaric acid (PCA) as the main active constituent. The hypo-pigmentation of PCA was verified in the MelanoDerm™ Skin Model. This study demonstrates that transformed HEK293-TYR cells could expedite the discovery of human TYR-specific inhibitors from natural sources which might be useful in the control of skin pigmentation.
CXO J133815.6+043255 is an ultraluminous X-ray source (ULX) with ultraviolet, optical, and radio counterparts located 10 kpc away from the nucleus of the galaxy NGC 5252. Optical spectroscopic studies indicate that the ULX is kinematically associated with NGC 5252; yet, the compactness of its radio emission could not rule out the possibility that the ULX is a background blazar. We present follow-up VLBA radio observations that are able to resolve the compact radio emission of the ULX into two components, making the blazar scenario very unlikely. The east component is extended at 4.4 GHz and its detection also at 7.6 GHz reveals a steep spectral index. The west component is only detected at 4.4 GHz, is not firmly resolved, and has a flatter spectral index. Considering that the west component hosts the radio core, we constrain the black hole mass of the ULX to 10 3.5 < M BH 2 × 10 6 M and its Eddington ratio to ∼ 10 −3 . The ULX is thus most likely powered by an intermediate-mass black hole or low-mass AGN. Our results constitute the first discovery of a multi-component radio jet in a ULX and possible intermediate-mass black hole.
We present geometric and dynamical modeling of the broad line region (BLR) for the multi-wavelength reverberation mapping campaign focused on NGC 5548 in 2014. The data set includes photometric and spectroscopic monitoring in the optical and ultraviolet, covering the Hβ, C IV, and Lyα broad emission lines. We find an extended disk-like Hβ BLR with a mixture of near-circular and outflowing gas trajectories, while the C IV and Lyα BLRs are much less extended and resemble shell-like structures. There is clear radial structure in the BLR, with C IV and Lyα emission arising at smaller radii than the Hβ emission. Using the three lines, we make three independent black hole mass measurements, all of which are consistent. Combining these results gives a joint inference of ( )7.64 10 BH 0.18 0.21 . We examine the effect of using the V band instead of the UV continuum light curve on the results and find a size difference that is consistent with the measured UV-optical time lag, but the other structural and kinematic parameters remain unchanged, suggesting that the V band is a suitable proxy for the ionizing continuum when exploring the BLR structure and kinematics. Finally, we compare the Hβ results to similar models of data obtained in 2008 when the active galactic nucleus was at a lower luminosity state. We find that the size of the emitting region increased during this time period, but the geometry and black hole mass remained unchanged, which confirms that the BLR kinematics suitably gauge the gravitational field of the central black hole.
We have observed the environments of a population of 33 heavily dust obscured, ultraluminous, high-redshift galaxies, selected using WISE and NVSS at z >1.3 with the Infra-Red Array Camera on the Spitzer Space Telescope over 5.12 ×5.12 fields. Colour selections are used to quantify any potential overdensities of companion galaxies in these fields. We find no significant excess of galaxies with the standard colour selection for IRAC colours of [3.6] − [4.5] > −0.1 consistent with galaxies at z >1.3 across the whole fields with respect to wide-area Spitzer comparison fields, but there is a > 2σ statistical excess within 0.25 of the central radio-WISE galaxy. Using a colour selection of [3.6] − [4.5] > 0.4, 0.5 magnitudes redder than the standard method of selecting galaxies at z >1.3, we find a significant overdensity, in which 76% (33%) of the 33 fields have a surface density greater than the 3σ (5σ) level. There is a statistical excess of these redder galaxies within 0.5 , rising to a central peak ∼ 2-4 times the average density. This implies that these galaxies are statistically linked to the radio-WISE selected galaxy, indicating similar structures to those traced by red galaxies around radio-loud AGN.
We present near-IR photometry and spectroscopy of 30 extremely luminous radio and mid-IR-selected galaxies. With bolometric luminosities exceeding ∼1013 $\rm {L_{\odot }}$ and redshifts ranging from z = 0.880 to 2.853, we use Very Large Telescope instruments X-shooter and Infrared Spectrometer and Array Camera to investigate this unique population of galaxies. Broad multicomponent emission lines are detected in 18 galaxies and we measure the near-IR lines $\rm {H\,\rm {\beta }}$, $\rm{[O\,{\small III}]}\, \rm {\lambda }\rm {\lambda }4959,5007$, and $\rm {H\,\rm {\alpha }}$ in 6, 15, and 13 galaxies, respectively, with 10 $\rm {Ly\,\alpha }$ and 5 C iv lines additionally detected in the UVB arm. We use the broad $\rm{[O\,{\small III}]}\, \rm {\lambda }5007$ emission lines as a proxy for the bolometric active galactic nucleus luminosity, and derive lower limits to supermassive black hole masses of 107.9–109.4 M⊙ with expectations of corresponding host masses of 1010.4–1012.0 M⊙. We measure $\rm {\lambda }_{Edd}$ > 1 for eight of these sources at a 2σ significance. Near-IR photometry and SED fitting are used to compare stellar masses directly. We detect both Balmer lines in five galaxies and use these to infer a mean visual extinction of AV = 2.68 mag. Due to non-detections and uncertainties in our ${\rm H}\, \beta$ emission line measurements, we simulate a broad ${\rm H}\, \beta$ line of FWHM = 1480 $\rm {kms^{-1}}$ to estimate extinction for all sources with measured ${\rm H}\, \alpha$ emission. We then use this to infer a mean AV = 3.62 mag, demonstrating the highly obscured nature of these galaxies, with the consequence of increasing our estimates of black hole masses by a 0.5 orders of magnitude in the most extreme and obscured cases.
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