567 research outputs found

    SDSS J163459.82+204936.0: A Ringed Infrared-Luminous Quasar with Outflows in both Absorption and Emission Lines

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    SDSS J1634+2049 is a local (z = 0.1293) infrared-luminous quasar with LIR= 10^11.91 Lsun. We present a detailed multiwavelength study of both the host galaxy and the nucleus. The host galaxy demonstrates violent, obscured star formation activities with SFR ~ 140 Msun yr^-1, estimated from either the PAH emission or IR luminosity. The optical to NIR spectra exhibit a blueshifted narrow cuspy component in Hb, HeI5876,10830 and other emission lines consistently with an offset velocity of ~900 km/s, as well as additional blueshifting phenomena in high-ionization lines , while there exist blueshifted broad absorption lines (BALs) in NaID and HeI*3889,10830, indicative of the AGN outflows producing BALs and emission lines. Constrained mutually by the several BALs with CLOUDY, the physical properties of the absorption-line outflow are derived as follows: 10^4 < n_H <= 10^5 cm^-3, 10^-1.3 <= U <= 10^-0.7 and 10^22.5<= N_H <= 10^22.9 cm^-2 , similar to those derived for the emission-line outflows. The similarity suggests a common origin. Taking advantages of both the absorption lines and outflowing emission lines, we find that the outflow gas is located at a distance of 48 - 65 pc from the nucleus, and that the kinetic luminosity of the outflow is 10^44-10^46 erg s^-1. J1634+2049 has a off-centered galactic ring on the scale of ~ 30 kpc that is proved to be formed by a recent head-on collision by a nearby galaxy. Thus this quasar is a valuable object in the transitional phase emerging out of dust enshrouding as depicted by the co-evolution scenario.Comment: 13 figures, 6 tables; accepted for publication in Ap

    4-Methyl-2-oxo-2,3-dihydro-1-benzopyran-7-yl benzene­sulfonate

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    The title compound, C16H12O5S, is a derivative of coumarin. The dihedral angle between the coumarin ring system and the phenyl ring is 65.9 (1)°. In the crystal structure, mol­ecules are linked by weak C—H⋯O hydrogen bonding to form molecular ribbons

    Chloroplast RNA-Binding Protein RBD1 Promotes Chilling Tolerance through 23S rRNA Processing in Arabidopsis

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    Plants have varying abilities to tolerate chilling (low but not freezing temperatures), and it is largely unknown how plants such as Arabidopsis thaliana achieve chilling tolerance. Here, we describe a genome-wide screen for genes important for chilling tolerance by their putative knockout mutants in Arabidopsis thaliana. Out of 11,000 T-DNA insertion mutant lines representing half of the genome, 54 lines associated with disruption of 49 genes had a drastic chilling sensitive phenotype. Sixteen of these genes encode proteins with chloroplast localization, suggesting a critical role of chloroplast function in chilling tolerance. Study of one of these proteins RBD1 with an RNA binding domain further reveals the importance of chloroplast translation in chilling tolerance. RBD1 is expressed in the green tissues and is localized in the chloroplast nucleoid. It binds directly to 23S rRNA and the binding is stronger under chilling than at normal growth temperatures. The rbd1 mutants are defective in generating mature 23S rRNAs and deficient in chloroplast protein synthesis especially under chilling conditions. Together, our study identifies RBD1 as a regulator of 23S rRNA processing and reveals the importance of chloroplast function especially protein translation in chilling tolerance. © 2016 Wang et al

    Using Text Mining to Extract Issues for School: an Empirical Study of the Social Platform-Dcard

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    Nowadays, social network within sentiment analysis has become the main trend in text mining domain. There are many platforms have been analyzed, such as Facebook, Twitter, Instagram, and so on. In our manuscript, we attempt to extract the information about the sentiment polarity of messages (positive, neutral or negative) in a social platform “Dcard”. The users of Dcard are Taiwanese college students, and anonymous post is being used this in social platform, therefore, the user can express their opinion more freedom. We use Dcard to the sentiment polarity of messages in extract the information about the school; moreover, the school could get the feedback from this finding to improve their policy. In this paper, we used python to scrap the web page, and the sentiment lexicon would be built

    Blockage of NOX2/MAPK/NF- κ

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    Acute energy failure is one of the critical factors contributing to the pathogenic mechanisms of retinal ischemia. Our previous study demonstrated that glucose deprivation can lead to a caspase-dependent cell death of photoreceptors. The aim of this study was to decipher the upstream signal pathway in glucose deprivation- (GD-) induced cell death. We mimicked acute energy failure by using glucose deprivation in photoreceptor cells (661W cells). GD-induced oxidative stress was evaluated by measuring ROS with the DCFH-DA assay and HO-1 expression by Western blot analysis. The activation of NOX2/MAPK/NF-κB signal was assessed by Western blot and immunohistochemical assays. The roles of these signals in GD-induced cell death were measured by using their specific inhibitors. Inhibition of Rac-1 and NOX2 suppressed GD-induced oxidative stress and protected photoreceptors against GD-induced cell death. NOX2 was an upstream signal in the caspase-dependent cell death cascade, yet the downstream MAPK pathways were activated and blocking MAPK signals rescued 661W cells from GD-induced death. In addition, GD caused the activation of NF-κB signal and inhibiting NF-κB significantly protected 661W cells. These observations may provide insights for treating retinal ischemic diseases and protecting retinal neurons from ischemia-induced cell death

    Bis{6,6′-dimeth­oxy-2,2′-[ethane-1,2-diyl­bis(imino­methyl­ene)]diphenolato(1.5−)-κ4 O,N,N′,O′}praeseodymium(III)

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    The title compound, [Pr(C18H22.5N2O4)2], is isotypic with its Er and Tb analogues. All interatomic distances, angles and the hydrogen bond geometry are very similar for the three structures.

    Bis{6,6′-dimeth­oxy-2,2′-[ethane-1,2-diyl­bis(imino­methyl­ene)]diphenolato(1.5−)-κ4 O,N,N′,O′}terbium(III)

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    The title compound, [Tb(C18H22.5N2O4)2], is isotypic with its Pr and Tb analogues. All interatomic distances, angles and the hydrogen bond geometry are very similar for the three structures
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