8,434 research outputs found
Detection of X-ray periodicity from a new eclipsing polar candidate XGPS-I J183251-100106
We report the results from a detailed analysis of an archival XMM-Newton
observation of the X-ray source XGPS-I J183251-100106, which has been suggested
as a promising magnetic cataclysmic variable candidate based on its optical
properties. A single periodic signal of 1.5 hrs is detected from all EPIC
cameras on board XMM-Newton. The phase-averaged X-ray spectrum can be
well-modeled with a thermal bremsstrahlung of a temperature kT~50 keV. Both
X-ray spectral and temporal behavior of this system suggest it as a eclipsing
cataclysmic variable of AM Herculis (or polar) type.Comment: 15 pages, 6 figures, accepted for publication in Ap
Discovery of X-ray pulsations from "next Geminga" - PSR J1836+5925
We report the X-ray pulsation of ~173.3 ms for the "next Geminga", PSR
J1836+5925, with recent XMM-Newton investigations. The X-ray periodicity is
consistent wtih the gamma-ray ephemeris at the same epoch. The X-ray folded
light curve has a sinusoidal structure which is different from the
double-peaked gamma-ray pulse profile. We have also analysed the X-ray
phase-averaged spectra which shows the X-ray emission from PSR J1836+5925 is
thermal dominant. This suggests the X-ray pulsation mainly originates from the
modulated hot spot on the stellar surface.Comment: 7 pages, 3 figures, 1 table, accepted for publication in ApJ Lette
A study of resiliency among Chinese health care workers: Capacity to cope with workplace stress
This paper reports a study of resiliency to cope with workplace stress among Chinese health care workers. We adopted a qualitative-quantitative-biomarker approach to conduct interviews, focus group discussions, and a two-wave longitudinal survey. Wave 1 survey was conducted among health care workers in Hong Kong and Mainland China (N = 773). Amongst them, 287 took part in Wave 2 survey. A confirmatory factor analysis consistently supported a 9-item scale. A sub-sample's (N = 33) resiliency was positively related to salivary IgA levels (an immune marker). Results from hierarchical regressions demonstrated that resiliency measured in Wave 1 was positively related to job satisfaction, work-life balance, and quality of life; and negatively related to physical/psychological symptoms and injuries at work in Wave 2. © 2009 Elsevier Inc. All rights reserved.postprin
A Tourism Financial Conditions Index
__Abstract__
The paper uses monthly data on financial stock index returns, tourism stock sub-index returns, effective exchange rate returns and interest rate differences from April 2005 – August 2013 for Taiwan that applies Chang’s (2014) novel approach for constructing a tourism financial indicator, namely the Tourism Financial Conditions Index (TFCI). The TFCI is an adaptation and extension of the widely-used Monetary Conditions Index (MCI) and Financial Conditions Index (FCI) to tourism stock data. However, the method of calculation of the TFCI is different from existing methods of constructing the MCI and FCI in that the weights are estimated empirically. The empirical findings show that TFCI is estimated quite accurately using the estimated conditional mean of the tourism stock index returns. The new TFCI is straightforward to use and interpret, and provides interesting insights in predicting the current economic and financial environment for tourism stock index returns that are based on publicly available information. In particular, the use of market returns on the tourism stock index as the sole indicator of the tourism sector, as compared with the general activity of economic variables on tourism stocks, is shown to provide an exaggerated and excessively volatile explanation of tourism financial conditions
Azimuthal distributions of radial momentum and velocity in relativistic heavy ion collisions
Azimuthal distributions of radial (transverse) momentum, mean radial
momentum, and mean radial velocity of final state particles are suggested for
relativistic heavy ion collisions. Using transport model AMPT with string
melting, these distributions for Au + Au collisions at 200 GeV are presented
and studied. It is demonstrated that the distribution of total radial momentum
is more sensitive to the anisotropic expansion, as the anisotropies of final
state particles and their associated transverse momentums are both counted in
the measure. The mean radial velocity distribution is compared with the radial
{\deg}ow velocity. The thermal motion contributes an isotropic constant to mean
radial velocity
GPER-induced signaling is essential for the survival of breast cancer stem cells.
G protein-coupled estrogen receptor-1 (GPER), a member of the G protein-coupled receptor (GPCR) superfamily, mediates estrogen-induced proliferation of normal and malignant breast epithelial cells. However, its role in breast cancer stem cells (BCSCs) remains unclear. Here we showed greater expression of GPER in BCSCs than non-BCSCs of three patient-derived xenografts of ER- /PR+ breast cancers. GPER silencing reduced stemness features of BCSCs as reflected by reduced mammosphere forming capacity in vitro, and tumor growth in vivo with decreased BCSC populations. Comparative phosphoproteomics revealed greater GPER-mediated PKA/BAD signaling in BCSCs. Activation of GPER by its ligands, including tamoxifen (TMX), induced phosphorylation of PKA and BAD-Ser118 to sustain BCSC characteristics. Transfection with a dominant-negative mutant BAD (Ser118Ala) led to reduced cell survival. Taken together, GPER and its downstream signaling play a key role in maintaining the stemness of BCSCs, suggesting that GPER is a potential therapeutic target for eradicating BCSCs
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