A Comprehensive Study of Broad Absorption Line Quasars: I. Prevalence of HeI* Absorption Line Multiplets in Low-Ionization Objects

Neutral Helium multiplets, HeI*3189,3889,10830 are very useful diagnostics to the geometry and physical conditions of the absorbing gas in quasars. So far only a handful of HeI* detections have been reported. Using a newly developed method, we detected HeI*3889 absorption line in 101 sources of a well-defined sample of 285 MgII BAL quasars selected from the SDSS DR5. This has increased the number of HeI* BAL quasars by more than one order of magnitude. We further detected HeI*3189 in 50% (52/101) quasars in the sample. The detection fraction of HeI* BALs in MgII BAL quasars is about 35% as a whole, and increases dramatically with increasing spectral signal-to-noise ratios, from 18% at S/N = 35. This suggests that HeI* BALs could be detected in most MgII LoBAL quasars, provided spectra S/N is high enough. Such a surprisingly high HeI* BAL fraction is actually predicted from photo-ionization calculations based on a simple BAL model. The result indicates that HeI* absorption lines can be used to search for BAL quasars at low-z, which cannot be identified by ground-based optical spectroscopic survey with commonly seen UV absorption lines. Using HeI*3889, we discovered 19 BAL quasars at z<0.3 from available SDSS spectral database. The fraction of HeI* BAL quasars is similar to that of LoBAL objects.Comment: Accepted for publication in ApJS. Tables 3, 4, 8, and 9 are now available in its entirety at the arXiv website along with the manuscript file, and will also be available via the link to the machine-readable tables on the ApJS websit

A new unconventional HLA-A2-restricted epitope from HBV core protein elicits antiviral cytotoxic T lymphocytes

Cytotoxic T cells (CTLs) play a key role in the control of Hepatitis B virus (HBV) infection and viral clearance. However, most of identified CTL epitopes are derived from HBV of genotypes A and D, and few have been defined in virus of genotypes B and C which are more prevalent in Asia. As HBV core protein (HBc) is the most conservative and immunogenic component, in this study we used an overlapping 9-mer peptide pool covering HBc to screen and identify specific CTL epitopes. An unconventional HLA-A2-restricted epitope HBc141–149 was discovered and structurally characterized by crystallization analysis. The immunogenicity and anti-HBV activity were further determined in HBV and HLA-A2 transgenic mice. Finally, we show that mutations in HBc141–149 epitope are associated with viral parameters and disease progression in HBV infected patients. Our data therefore provide insights into the structure characteristics of this unconventional epitope binding to MHC-I molecules, as well as epitope specific CTL activity that orchestrate T cell response and immune evasion in HBV infected patients

Di-μ-aqua-bis­{diaqua­[μ-4-({4-[bis­(2-hy­droxy­eth­yl)amino]-6-chloro-1,3,5-triazin-2-yl}amino)­benzene­sulfonato]­sodium(I)}

In the dinuclear title compound, [Na2(C13H15ClN5O5S)2(H2O)6]n, two Na+ cations, disposed about a centre of inversion, are linked by two bridging water mol­ecules. The coordination geometry is based on an O5 donor set defined by four water mol­ecules and a 4-amino­benzene­sulfonate O atom in a distorted trigonal–bipyramidal geometry. In the crystal, significant O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds lead to the formation of a three-dimensional architecture

Federated learning based intelligent edge computing technique for video surveillance

With the explosion of global data,centralized cloud computing cannot provide low-latency,high-efficiency video surveillance services.A distributed edge computing model was proposed,which directly processed video data at the edge node to reduce the transmission pressure of the network,eased the computational burden of the central cloud server,and reduced the processing delay of the video surveillance system.Combined with the federated learning algorithm,a lightweight neural network was used,which trained in different scenarios and deployed on edge devices with limited computing power.Experimental results show that,compared with the general neural network model,the detection accuracy of the proposed method is improved by 18%,and the model training time is reduced

Spin dynamics in semiconductors

This article reviews the current status of spin dynamics in semiconductors which has achieved a lot of progress in the past years due to the fast growing field of semiconductor spintronics. The primary focus is the theoretical and experimental developments of spin relaxation and dephasing in both spin precession in time domain and spin diffusion and transport in spacial domain. A fully microscopic many-body investigation on spin dynamics based on the kinetic spin Bloch equation approach is reviewed comprehensively.Comment: a review article with 193 pages and 1103 references. To be published in Physics Reports

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Liraglutide-induced reduction of myocardial ischemiareperfusion injury in rats via ERK1/2 signaling pathway

Purpose: To investigate the protective effect of liraglutide on myocardial ischemia reperfusion (I/R) injury and its molecular mechanism.Methods: Ischemia reperfusion model male Sprague-Dawley (SD) rats were randomly divided into negative control group, I/R group (saline), liraglutide group (liraglutide) and PD group (liraglutide + PD98059). The weight of myocardium in ischemic and infarction areas of the heart, myocardial injury biomarker, oxidative stress, as well as expressions of mRNA molecules of apoptosis were determined.Results: The myocardial mass of ischemic and infarcted areas of the heart (relative to left ventricular mass) of I/R group were significantly higher (p ˂ 0.05) than those of negative control group, but significantly lower in liraglutide group than in I/R group (p &gt; 0.05). However, the parameters were significantly higher in PD group than in liraglutide group (p ˂ 0.05). CK, CK-MB and LDH activities, as well as levels of cTnI and cTnT in I/R group were significantly higher (p ˂ 0.05) than those of negative control group. However, the parameters were significantly lower (p ˂ 0.05) in liraglutide group than in I/R group, but higher in PD group (p ˂ 0.05) than in liraglutide group. Serum SOD, GSH-Px, CAT activities and tBcl-2 mRNA expression were significantly lower in I/R group than those of negative control group (p ˂ 0.001), while those PD group were significantly lower than those of liraglutide group (p ˂ 0.001).Conclusion: Liraglutide alleviates myocardial ischemia-reperfusion injury and inhibits oxidative stress and apoptosis via ERK1/2 signaling pathway in rats, but further studies are required to ascertain the clinical efficacy and safety of the compound.Keywords: Ischemia-reperfusion injury, Liraglutide, ERK1/2 signal pathway, Oxidative stress, Apoptosi