407 research outputs found
Inactivation of myosin binding protein C homolog in zebrafish as a model for human cardiac hypertrophy and diastolic dysfunction
[[incitationindex]]SC
Deep Chandra X-ray Imaging of a Nearby Radio Galaxy 4C+29.30: X-ray/Radio Connection
We report results from our deep Chandra X-ray observations of a nearby radio
galaxy, 4C+29.30 (z=0.0647). The Chandra image resolves structures on
sub-arcsec to arcsec scales, revealing complex X-ray morphology and detecting
the main radio features: the nucleus, a jet, hotspots, and lobes. The nucleus
is absorbed (N(H)=3.95 (+0.27/-0.33)x10^23 atoms/cm^2) with an unabsorbed
luminosity of L(2-10 keV) ~ (5.08 +/-0.52) 10^43 erg/s characteristic of Type 2
AGN. Regions of soft (<2 keV) X-ray emission that trace the hot interstellar
medium (ISM) are correlated with radio structures along the main radio axis
indicating a strong relation between the two. The X-ray emission beyond the
radio source correlates with the morphology of optical line-emitting regions.
We measured the ISM temperature in several regions across the galaxy to be kT ~
0.5 with slightly higher temperatures (of a few keV) in the center and in the
vicinity of the radio hotspots. Assuming these regions were heated by weak
shocks driven by the expanding radio source, we estimated the corresponding
Mach number of 1.6 in the southern regions. The thermal pressure of the X-ray
emitting gas in the outermost regions suggest the hot ISM is slightly
under-pressured with respect to the cold optical-line emitting gas and
radio-emitting plasma, which both seem to be in a rough pressure equilibrium.
We conclude that 4C+29.30 displays a complex view of interactions between the
jet-driven radio outflow and host galaxy environment, signaling feedback
processes closely associated with the central active nucleus.Comment: ApJ in pres
Components of the Extragalactic Gamma Ray Background
We present new theoretical estimates of the relative contributions of
unresolved blazars and star-forming galaxies to the extragalactic gamma-ray
background (EGB) and discuss constraints on the contributions from alternative
mechanisms such as dark matter annihilation and truly diffuse gamma-ray
production. We find that the Fermi source count data do not rule out a scenario
in which the EGB is dominated by emission from unresolved blazars, though
unresolved star-forming galaxies may also contribute significantly to the
background, within order-of-magnitude uncertainties. In addition, we find that
the spectrum of the unresolved star-forming galaxy contribution cannot explain
the EGB spectrum found by EGRET at energies between 50 and 200 MeV, whereas the
spectrum of unresolved FSRQs, when accounting for the energy-dependent effects
of source confusion, could be consistent with the combined spectrum of the
low-energy EGRET EGB measurements and the Fermi-LAT EGB measurements.Comment: version accepted for publication in the Astrophysical Journa
An overview of the current status of CMB observations
In this paper we briefly review the current status of the Cosmic Microwave
Background (CMB) observations, summarising the latest results obtained from CMB
experiments, both in intensity and polarization, and the constraints imposed on
the cosmological parameters. We also present a summary of current and future
CMB experiments, with a special focus on the quest for the CMB B-mode
polarization.Comment: Latest CMB results have been included. References added. To appear in
"Highlights of Spanish Astrophysics V", Proceedings of the VIII Scientific
Meeting of the Spanish Astronomical Society (SEA) held in Santander, 7-11
July, 200
Benchmark problems for robust control design
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76996/1/AIAA-20949-475.pd
Small but crucial : the novel small heat shock protein Hsp21 mediates stress adaptation and virulence in Candida albicans
Peer reviewedPublisher PD
Women's preference for cesarean delivery and differences between Taiwanese women undergoing different modes of delivery
<p>Abstract</p> <p>Background</p> <p>The rate of cesarean delivery was 35% in 2007 in Taiwan. It is unclear how many of the cesarean deliveries were without medical indications. Women's preference for cesarean delivery during their course of pregnancy has rarely been studied and therefore our objectives were to examine rate of cesarean deliveries without medical indications, to explore women's preference for cesarean delivery as their gestation advances, and to compare background and perinatal factors among women who underwent different modes of delivery in Taiwan.</p> <p>Methods</p> <p>This prospective study applied a longitudinal design. The study participants were 473 women who received prenatal care at four hospitals in Taipei and answered structured questionnaires at 20 to 24 weeks of pregnancy, 34 to 36 weeks of pregnancy, and 5 to 7 weeks after delivery.</p> <p>Results</p> <p>Of the 151 women (31.9%) who had cesarean deliveries, 19.9% were without medical indication. Three indications: malpresentation, prior cesarean section, and dysfunctional labor together accounted for 82.6% of cesarean section with medical indications. The prevalence of maternal preference for cesarean delivery was found to be 12.5% and 17.5% during the second and third trimester, respectively. Of the women who preferred cesarean delivery during the second trimester, 93.2% eventually had a cesarean delivery. Women who were older, with older spouses, and who had health problems before or during pregnancy were more likely to have cesarean deliveries.</p> <p>Conclusions</p> <p>About 20% of cesarean deliveries were without medical indications. Women's preference for cesarean delivery during the second trimester predicts subsequent cesarean delivery. Counseling regarding mode of delivery should be offered early in pregnancy, especially for women who are older or with older spouses, have health problems, or had a prior cesarean section.</p
Fermi Large Area Telescope Gamma-Ray Detection of the Radio Galaxy M87
We report the Fermi-LAT discovery of high-energy (MeV/GeV) gamma-ray emission
positionally consistent with the center of the radio galaxy M87, at a source
significance of over 10 sigma in ten-months of all-sky survey data. Following
the detections of Cen A and Per A, this makes M87 the third radio galaxy seen
with the LAT. The faint point-like gamma-ray source has a >100 MeV flux of 2.45
(+/- 0.63) x 10^-8 ph cm^-2 s^-1 (photon index = 2.26 +/- 0.13) with no
significant variability detected within the LAT observation. This flux is
comparable with the previous EGRET upper limit (< 2.18 x 10^-8 ph cm^-2 s^-1, 2
sigma), thus there is no evidence for a significant MeV/GeV flare on decade
timescales. Contemporaneous Chandra and VLBA data indicate low activity in the
unresolved X-ray and radio core relative to previous observations, suggesting
M87 is in a quiescent overall level over the first year of Fermi-LAT
observations. The LAT gamma-ray spectrum is modeled as synchrotron self-Compton
(SSC) emission from the electron population producing the radio-to-X-ray
emission in the core. The resultant SSC spectrum extrapolates smoothly from the
LAT band to the historical-minimum TeV emission. Alternative models for the
core and possible contributions from the kiloparsec-scale jet in M87 are
considered, and can not be excluded.Comment: ApJ, accepted, 6 pages, 4 figures. Corresponding authors: C.C.
Cheung, W. McConvill
Illegal immigration and media exposure: evidence on individual attitudes
Illegal immigration has been the focus of much debate in receiving countries, but little is known about the drivers of individual attitudes towards illegal immigrants. To study this question, we use the CCES survey, which was carried out in 2006 in the USA. We find evidence thatâin addition to standard labor market and welfare state considerationsâmedia exposure is significantly correlated with public opinion on illegal immigration. Controlling for education, income, ideology, and other socio-demographic characteristics, individuals watching Fox News are 9 percentage points more likely than CBS viewers to oppose the legalization of undocumented immigrants. We find an effect of the same size and direction for CNN viewers, whereas individuals watching PBS are instead more likely to support legalization. Ideological self-selection into different news programs plays an important role, but cannot entirely explain the correlation between media exposure and attitudes about illegal immigration
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