Variability of Low-ionization Broad Absorption Line Quasars Based on Multi-epoch Spectra from The Sloan Digital Sky Survey

We present absorption variability results for 134 bona fide \mgii\ broad absorption line (BAL) quasars at 0.46~$\lesssim z \lesssim$~2.3 covering days to $\sim$ 10 yr in the rest frame. We use multiple-epoch spectra from the Sloan Digital Sky Survey, which has delivered the largest such BAL-variability sample ever studied. \mgii-BAL identifications and related measurements are compiled and presented in a catalog. We find a remarkable time-dependent asymmetry in EW variation from the sample, such that weakening troughs outnumber strengthening troughs, the first report of such a phenomenon in BAL variability. Our investigations of the sample further reveal that (i) the frequency of BAL variability is significantly lower (typically by a factor of 2) than that from high-ionization BALQSO samples; (ii) \mgii\ BAL absorbers tend to have relatively high optical depths and small covering factors along our line of sight; (iii) there is no significant EW-variability correlation between \mgii\ troughs at different velocities in the same quasar; and (iv) the EW-variability correlation between \mgii\ and \aliii\ BALs is significantly stronger than that between \mgii\ and \civ\ BALs at the same velocities. These observational results can be explained by a combined transverse-motion/ionization-change scenario, where transverse motions likely dominate the strengthening BALs while ionization changes and/or other mechanisms dominate the weakening BALs.Comment: 24 pages, accepted for publication in ApJ

Discovery From Non-Parties (Third-Party Discovery) in International Arbitration

International arbitration rules and many arbitration laws usually provide procedures that permit tribunals to order parties to disclose documents and other materials to the other parties.1 More complex are the rules that determine opportunities to obtain discovery from persons that are not party to the arbitration (third-party discovery). This article will review third-party discovery under the Federal Arbitration Act (FAA) and the provisions of the US Code s.1782 that authorise US courts to act in aid of actions before foreign tribunals. Section 1782 has unique interest at this time because it figured prominently in the EU antitrust investigation of Intel that was initiated on request from Advanced Micro Devices (AMD). Early in that investigation, AMD filed a s.1782 request in the US District Court to obtain evidence from US sources for submission to the DG-Competition of the European Commission (EC). This request ultimately led to the Supreme Court’s decision in Intel Corp v Advanced Micro Devices Inc2 which appeared to significantly expand the scope of s.1782. Ironically, after AMD won on key legal issues in the Supreme Court, the District Court on remand exercised its discretion and denied the request for judicial assistance. This paper first describes the FAA non-party discovery rules and the split among the federal appellate courts concerning the authority of arbitrators to order prehearing discovery from non-parties. Next, it provides an analysis of the meaning of the terms “interested party” and “tribunal”—terms that were controversially interpreted by the Supreme Court in Intel and are essential to the application of s.1782. Finally, it discusses the “discretionary” factors used by the federal courts in deciding whether to grant a s.1782 request even when the statutory criteria are met. The opportunity to exercise this discretion seems to rebut the argument that the Supreme Court’s interpretation of s.1782 gives participants before foreign tribunals more discovery rights in the United States than are available to the parties in arbitrations covered by the FAA

Same Sign WW Scattering Process as a Probe of Higgs Boson in pp Collision at s\sqrt{s} = 10 TeV

WW scattering is an important process to study electroweak symmetry breaking in the Standard Model at the LHC, in which the Higgs mechanism or other new physics processes must intervene to preserve the unitarity of the process below 1 TeV. This channel is expected to be one of the most sensitive to determine whether the Higgs boson exists. In this paper, the final state with two same sign Ws is studied, with a simulated sample corresponding to the integrated luminosity of 60 fb$^{-1}$ in pp collision at $\sqrt{s}=$10 TeV. Two observables, the invariant mass of $\mu\mu$ from W decays and the azimuthal angle difference between the two $\mu$s, are utilized to distinguish the Higgs boson existence scenario from the Higgs boson absence scenario. A good signal significance for the two cases can be achieved. If we define the separation power of the analysis as the distance, in the log-likelihood plane, of pseudo-experiments outcomes in the two cases, with the total statistics expected from the ATLAS and CMS experiments at the nominal centre-of-mass energy of 14 TeV, the separation power will be at the level of 4 $\sigma$.Comment: 5 pages, 4 figures, 3 table

Gender Gaps in the Measurement of Public Opinion About Homosexuality in Cross-national Surveys: A Question-Wording Experiment

Measures of attitudes towards homosexuality in cross-national studies have received criticism for not being ‘gender-sensitive’. The current study used a split-ballot design allowing for separate analyses of the attitudes towards ‘gay men and lesbian women’, ‘gay men’, and ‘lesbian women’ in a pooled sample of 3,381 participants from Great Britain, Hungary, and Portugal. Analyses controlling for sociodemographics showed that differences in attitudes towards male and female targets were generally small and did not interact with the gender of the rater. In addition, results showed that men’s attitudes towards homosexuality were more strongly related to their gender ideology than women’s attitudes. Implications of these findings for cross-national studies measuring attitudes towards homosexuality are discussed

An ultra-luminous quasar at z=5.363 with a ten billion solar mass black hole and a Metal-Rich DLA at z~5

We report the discovery of an ultra-luminous quasar J030642.51+185315.8 (hereafter J0306+1853) at redshift 5.363, which hosts a super-massive black hole (SMBH) with $M_{BH} = (1.07 \pm 0.27) \times10^{10}~M_\odot$. With an absolute magnitude $M_{1450}=-28.92$ and bolometric luminosity $L_{bol}\sim3.4\times10^{14} L_{\odot}$, J0306+1853 is one of the most luminous objects in the early Universe. It is not likely to be a beamed source based on its small flux variability, low radio loudness and normal broad emission lines. In addition, a $z=4.986$ Damped Ly$\alpha$ system (DLA) with $\rm [M/H]=-1.3\pm0.1$, among the most metal rich DLAs at $z \gtrsim 5$, is detected in the absorption spectrum of this quasar. This ultra-luminous quasar puts strong constraint on the bright-end of quasar luminosity function and massive-end of black hole mass function. It will provide a unique laboratory to the study of BH growth and the co-evolution between BH and host galaxy with multi-wavelength follow-up observations. The future high resolution spectra will give more insights to the DLA and other absorption systems along the line-of-sight of J0306+1853.Comment: 5 pages, 3 figures, accepted for publication in ApJ

Einstein Probe - a small mission to monitor and explore the dynamic X-ray Universe

Einstein Probe is a small mission dedicated to time-domain high-energy astrophysics. Its primary goals are to discover high-energy transients and to monitor variable objects in the $0.5-4~$keV X-rays, at higher sensitivity by one order of magnitude than those of the ones currently in orbit. Its wide-field imaging capability, featuring a large instantaneous field-of-view ($60^\circ \times60^\circ$, $\sim1.1$sr), is achieved by using established technology of micro-pore (MPO) lobster-eye optics, thereby offering unprecedentedly high sensitivity and large Grasp. To complement this powerful monitoring ability, it also carries a narrow-field, sensitive follow-up X-ray telescope based on the same MPO technology to perform follow-up observations of newly-discovered transients. Public transient alerts will be downlinked rapidly, so as to trigger multi-wavelength follow-up observations from the world-wide community. Over three of its 97-minute orbits almost the entire night sky will be sampled, with cadences ranging from 5 to 25 times per day. The scientific objectives of the mission are: to discover otherwise quiescent black holes over all astrophysical mass scales by detecting their rare X-ray transient flares, particularly tidal disruption of stars by massive black holes at galactic centers; to detect and precisely locate the electromagnetic sources of gravitational-wave transients; to carry out systematic surveys of X-ray transients and characterize the variability of X-ray sources. Einstein Probe has been selected as a candidate mission of priority (no further selection needed) in the Space Science Programme of the Chinese Academy of Sciences, aiming for launch around 2020.Comment: accepted to publish in PoS, Proceedings of "Swift: 10 Years of Discovery" (Proceedings of Science; ed. by P. Caraveo, P. D'Avanzo, N. Gehrels and G. Tagliaferri). Minor changes in text, references update

Negaton and Positon solutions of the soliton equation with self-consistent sources

The KdV equation with self-consistent sources (KdVES) is used as a model to illustrate the method. A generalized binary Darboux transformation (GBDT) with an arbitrary time-dependent function for the KdVES as well as the formula for $N$-times repeated GBDT are presented. This GBDT provides non-auto-B\"{a}cklund transformation between two KdV equations with different degrees of sources and enable us to construct more general solutions with $N$ arbitrary $t$-dependent functions. By taking the special $t$-function, we obtain multisoliton, multipositon, multinegaton, multisoliton-positon, multinegaton-positon and multisoliton-negaton solutions of KdVES. Some properties of these solutions are discussed.Comment: 13 pages, Latex, no figues, to be published in J. Phys. A: Math. Ge

Career preferences of graduating medical students in China: a nationwide cross-sectional study

Background: China faces major challenges in the distribution of health professionals with serious shortages in rural areas and in the development of Primary Care Providers (PCPs). This study investigates the career preferences of medical students in China and the impact of rural backgrounds on these preferences. Methods: Medical students in the final year of their program in 16 medical schools across China completed a 58-item survey that included questions regarding their demographic characteristics, attitudes toward practice in low resource areas, postgraduate planning, self-assessed competency, university facilities assessment, and financial situation. Descriptive calculation and Logit model were used for the analysis. Results: Completed surveys from 3020 students were included in the analysis. Upon graduation, 48.5 % of the medical students preferred to work in urban public hospitals and this percentage rose to 73.6 % when students were asked to state their anticipated preference five years after graduation. Students' top three ranked reasons for preferred careers were "good career prospects", "living close to parents/families", and "remuneration". Those who preferred to work in rural areas upon graduation were more likely to be those who lived in rural areas when 1-15 years old (beta = 2.05, p < 0.001), had high school in rural areas (beta = 1.73, p < 0.001), or had parents' place of current residence in rural areas (beta = 2.12, p < 0.001). Similar results were found for those students who preferred to work in PCPs. Conclusions: To address the serious shortages of health professionals in rural areas and PCPs, medical schools should consider strategies to recruit more medical applicants with rural backgrounds and to orient students to rural and primary care interests.SCI(E)[email protected]

Temporal Expression of Mutant LRRK2 in Adult Rats Impairs Dopamine Reuptake

Parkinson's disease (PD) results from progressive degeneration of dopaminergic neurons. Most PD cases are sporadic, but some have pathogenic mutation in the individual genes. Mutation of the leucine-rich repeat kinase-2 (LRRK2) gene is associated with familial and sporadic PD, as exemplified by G2019S substitution. While constitutive expression of mutant LRRK2 in transgenic mice fails to induce neuron death, transient expression of the disease gene by viral delivery causes a substantial loss of dopaminergic neurons in mice. To further assess LRRK2 pathogenesis, we created inducible transgenic rats expressing human LRRK2 with G2019S substitution. Temporal overexpression of LRRK2G2019S in adult rats impaired dopamine reuptake by dopamine transporter (DAT) and thus enhanced locomotor activity, the phenotypes that were not observed in transgenic rats constitutively expressing the gene throughout life time. Reduced DAT binding activity is an early sign of dopaminergic dysfunction in asymptomatic subjects carrying pathogenic mutation in LRRK2. Our transgenic rats recapitulated the initiation process of dopaminergic dysfunction caused by pathogenic mutation in LRRK2. Inducible transgenic approach uncovered phenotypes that may be obscured by developmental compensation in constitutive transgenic rats. Finding in inducible LRRK2 transgenic rats would guide developing effective strategy in transgenic studies: Inducible expression of transgene may induce greater phenotypes than constitutive gene expression, particularly in rodents with short life time