1,196 research outputs found
The First Two Years of Electromagnetic Follow-Up with Advanced LIGO and Virgo
We anticipate the first direct detections of gravitational waves (GWs) with
Advanced LIGO and Virgo later this decade. Though this groundbreaking technical
achievement will be its own reward, a still greater prize could be observations
of compact binary mergers in both gravitational and electromagnetic channels
simultaneously. During Advanced LIGO and Virgo's first two years of operation,
2015 through 2016, we expect the global GW detector array to improve in
sensitivity and livetime and expand from two to three detectors. We model the
detection rate and the sky localization accuracy for binary neutron star (BNS)
mergers across this transition. We have analyzed a large, astrophysically
motivated source population using real-time detection and sky localization
codes and higher-latency parameter estimation codes that have been expressly
built for operation in the Advanced LIGO/Virgo era. We show that for most BNS
events the rapid sky localization, available about a minute after a detection,
is as accurate as the full parameter estimation. We demonstrate that Advanced
Virgo will play an important role in sky localization, even though it is
anticipated to come online with only one-third as much sensitivity as the
Advanced LIGO detectors. We find that the median 90% confidence region shrinks
from ~500 square degrees in 2015 to ~200 square degrees in 2016. A few distinct
scenarios for the first LIGO/Virgo detections emerge from our simulations.Comment: 17 pages, 11 figures, 5 tables. For accompanying data, see
http://www.ligo.org/scientists/first2year
Are Debris Disks and Massive Planets Correlated?
Using data from the Spitzer Space Telescope Legacy Science Program
``Formation and Evolution of Planetary Systems'' (FEPS), we have searched for
debris disks around 9 FGK stars (2-10 Gyr), known from radial velocity (RV)
studies to have one or more massive planets. Only one of the sources, HD 38529,
has excess emission above the stellar photosphere; at 70 micron the
signal-to-noise ratio in the excess is 4.7 while at wavelengths < 30 micron
there is no evidence of excess. The remaining sources show no excesses at any
Spitzer wavelengths. Applying survival tests to the FEPS sample and the results
for the FGK survey published in Bryden et al. (2006), we do not find a
significant correlation between the frequency and properties of debris disks
and the presence of close-in planets. We discuss possible reasons for the lack
of a correlation.Comment: 24 pages, 3 figures. Accepted to Astrophysical Journa
A massive cluster of Red Supergiants at the base of the Scutum-Crux arm
We report on the unprecedented Red Supergiant (RSG) population of a massive
young cluster, located at the base of the Scutum-Crux Galactic arm. We identify
candidate cluster RSGs based on {\it 2MASS} photometry and medium resolution
spectroscopy. With follow-up high-resolution spectroscopy, we use CO-bandhead
equivalent width and high-precision radial velocity measurements to identify a
core grouping of 26 physically-associated RSGs -- the largest such cluster
known to-date. Using the stars' velocity dispersion, and their inferred
luminosities in conjuction with evolutionary models, we argue that the cluster
has an initial mass of 40,000\msun, and is therefore among the most
massive in the galaxy. Further, the cluster is only a few hundred parsecs away
from the cluster of 14 RSGs recently reported by Figer et al (2006). These two
RSG clusters represent 20% of all known RSGs in the Galaxy, and now offer the
unique opportunity to study the pre-supernova evolution of massive stars, and
the Blue- to Red-Supergiant ratio at uniform metallicity. We use GLIMPSE,
MIPSGAL and MAGPIS survey data to identify several objects in the field of the
larger cluster which seem to be indicative of recent region-wide starburst
activity at the point where the Scutum-Crux arm intercepts the Galactic bulge.
Future abundance studies of these clusters will therefore permit the study of
the chemical evolution and metallicity gradient of the Galaxy in the region
where the disk meets the bulge.Comment: 49 pages, 22 figures. Accepted for publication in ApJ. Version with
hi-res figures can be found at http://www.cis.rit.edu/~bxdpci/RSGC2.pd
Mass Flows in Cometary UCHII Regions
High spectral and spatial resolution, mid-infrared fine structure line
observations toward two ultracompact HII (UCHII) regions (G29.96 -0.02 and Mon
R2) allow us to study the structure and kinematics of cometary UCHII regions.
In our earlier study of Mon R2, we showed that highly organized mass motions
accounted for most of the velocity structure in that UCHII region. In this
work, we show that the kinematics in both Mon R2 and G29.96 are consistent with
motion along an approximately paraboloidal shell. We model the velocity
structure seen in our mapping data and test the stellar wind bow shock model
for such paraboloidal like flows. The observations and the simulation indicate
that the ram pressures of the stellar wind and ambient interstellar medium
cause the accumulated mass in the bow shock to flow along the surface of the
shock. A relaxation code reproduces the mass flow's velocity structure as
derived by the analytical solution. It further predicts that the pressure
gradient along the flow can accelerate ionized gas to a speed higher than that
of the moving star. In the original bow shock model, the star speed relative to
the ambient medium was considered to be the exit speed of ionized gas in the
shell.Comment: 34 pages, including 14 figures and 1 table, to be published in ApJ,
September 200
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The candidate genes TAF5L, TCF7, PDCD1, IL6 and ICAM1 cannot be excluded from having effects in type 1 diabetes.
BACKGROUND: As genes associated with immune-mediated diseases have an increased prior probability of being associated with other immune-mediated diseases, we tested three such genes, IL23R, IRF5 and CD40, for an association with type 1 diabetes. In addition, we tested seven genes, TAF5L, PDCD1, TCF7, IL12B, IL6, ICAM1 and TBX21, with published marginal or inconsistent evidence of an association with type 1 diabetes. METHODS: We genotyped reported polymorphisms of the ten genes, nonsynonymous SNPs (nsSNPs) and, for the IL12B and IL6 regions, tag SNPs in up to 7,888 case, 8,858 control and 3,142 parent-child trio samples. In addition, we analysed data from the Wellcome Trust Case Control Consortium genome-wide association study to determine whether there was any further evidence of an association in each gene region. RESULTS: We found some evidence of associations between type 1 diabetes and TAF5L, PDCD1, TCF7 and IL6 (ORs = 1.05 - 1.13; P = 0.0291 - 4.16 x 10-4). No evidence of an association was obtained for IL12B, IRF5, IL23R, ICAM1, TBX21 and CD40, although there was some evidence of an association (OR = 1.10; P = 0.0257) from the genome-wide association study for the ICAM1 region. CONCLUSION: We failed to exclude the possibility of some effect in type 1 diabetes for TAF5L, PDCD1, TCF7, IL6 and ICAM1. Additional studies, of these and other candidate genes, employing much larger sample sizes and analysis of additional polymorphisms in each gene and its flanking region will be required to ascertain their contributions to type 1 diabetes susceptibility.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Remote mental health care interventions during the COVID-19 pandemic: an umbrella review
Mitigating the COVID-19 related disruptions in mental health care services is crucial in a time of increased mental health disorders. Numerous reviews have been conducted on the process of implementing technology- based mental health care during the pandemic. The research question of this umbrella review was to examine what the impact of COVID-19 was on access and delivery of mental health services and how mental health services have changed during the pandemic. A systematic search for systematic reviews and meta-analyses was conducted up to August 12, 2022, and 38 systematic reviews were identified. Main disruptions during COVID-19 were reduced access to outpatient mental health care and reduced admissions and earlier discharge from inpatient care. In response, synchronous telemental health tools such as videoconferencing were used to provide remote care similar to pre-COVID care, and to a lesser extent asynchronous virtual mental health tools such as apps. Implementation of synchronous tools were facilitated by time-efficiency and flexibility during the pandemic but there was a lack of accessibility for specific vulnerable populations. Main barriers among prac- titioners and patients to use digital mental health tools were poor technological literacy, particularly when preexisting inequalities existed, and beliefs about reduced therapeutic alliance particularly in case of severe mental disorders. Absence of organizational support for technological implementation of digital mental health interventions due to inadequate IT infrastructure, lack of funding, as well as lack of privacy and safety, chal- lenged implementation during COVID-19. Reviews were of low to moderate quality, covered heterogeneously designed primary studies and lacked findings of implementation in low- and middle-income countries. These gaps in the evidence were particularly prevalent in studies conducted early in the pandemic. This umbrella review shows that during the COVID-19 pandemic, practitioners and mental health care institutions mainly used synchronous telemental health tools, and to a lesser degree asynchronous tools to enable continued access to mental health care for patients. Numerous barriers to these tools were identified, and call for further improve- ments. In addition, more high quality research into comparative effectiveness and working mechanisms may improve scalability of mental health care in general and in future infectious disease outbreaks
Civilian casualties and public support for military action: Experimental evidence
In contrast to the expansive literature on military casualties and support for war, we know very little about public reactions to foreign civilian casualties. This article, based on representative sample surveys in the US and Britain, reports four survey experiments weaving information about civilian casualties into vignettes about Western military action. These produce consistent evidence of civilian casualty aversion: where death tolls were higher, support for force was invariably and significantly lower. Casualty effects were moderate in size but robust across our two cases and across different scenarios. They were also strikingly resistant to moderation by other factors manipulated in the experiments, such as the framing of casualties or their religious affiliation. The importance of numbers over even strongly humanizing frames points towards a utilitarian rather than a social-psychological model of casualty aversion. Either way, civilian casualties deserve a more prominent place in the literature on public support for war
Molecular Gas in the z=1.2 Ultraluminous Merger GOODS J123634.53+621241.3
We report the detection of CO(2-1) emission from the z=1.2 ultraluminous
infrared galaxy (ULIRG) GOODS J123634.53+621241.3 (also known as the
sub-millimeter galaxy GN26). These observations represent the first discovery
of high-redshift CO emission using the new Combined Array for Research in
Millimeter-Wave Astronomy (CARMA). Of all high-redshift (z>1) galaxies within
the GOODS-North field, this source has the largest far-infrared (FIR) flux
observed in the Spitzer 70um and 160um bands. The CO redshift confirms the
optical identification of the source, and the bright CO(2-1) line suggests the
presence of a large molecular gas reservoir of about 7x10^10 M(sun). The
infrared-to-CO luminosity ratio of L(IR)/L'(CO) = 80+/-30 L(sun) (K Km/s
pc^2)^-1 is slightly smaller than the average ratio found in local ULIRGs and
high-redshift sub-millimeter galaxies. The short star-formation time scale of
about 70 Myr is consistent with a starburst associated with the merger event
and is much shorter than the time scales for spiral galaxies and estimates made
for high-redshift galaxies selected on the basis of their B-z and z-K colors.Comment: Accepted for publication in ApJ Letter
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Cataclysmic Variables from Sloan Digital Sky Survey. IV. The Fourth Year (2003)
This paper continues the series presenting cataclysmic variables identified during the fourth year (2003) of the Sloan Digital Sky Survey. We describe 44 close binary systems, of which 12 are the previously known systems EN Cet, EG Cnc, V844 Her, GG Leo, Leo 7, CY UMa, DV UMa, EK UMa, EV UMa, UMa 8, EUVE J0854+390, and RX J0859.1+0537 and 32 are new cataclysmic variables. As in the previous papers, the positions, colors, and spectra of all 44 systems are shown, along with follow-up spectroscopic, photometric, and/or polarimetric observations of 15 of the new systems. The new objects include one eclipsing system, eight with prominent He II emission (of which two are confirmed new polars), and 12 systems showing features of the underlying stars. Our spectropolarimetry also confirms EUVE J0854+390 as a polar
Detection of enterovirus RNA in peripheral blood mononuclear cells correlates with the presence of the predisposing allele of the type 1 diabetes risk gene IFIH1 and with disease stage
Aims/hypothesis Enteroviral infection has been implicated consistently as a key environmental factor correlating with the appearance of autoimmunity and/or the presence of overt type 1 diabetes, in which pancreatic insulin-producing beta cells are destroyed by an autoimmune response. Genetic predisposition through variation in the type 1 diabetes risk gene IFIH1 (interferon induced with helicase C domain 1), which encodes the viral pattern-recognition receptor melanoma differentiation-associated protein 5 (MDA5), supports a potential link between enterovirus infection and type 1 diabetes. Methods We used molecular techniques to detect enterovirus RNA in peripheral blood samples (in separated cellular compartments or plasma) from two cohorts comprising 79 children or 72 adults that include individuals with and without type 1 diabetes who had multiple autoantibodies. We also used immunohistochemistry to detect the enteroviral protein VP1 in the pancreatic islets of post-mortem donors (n=43) with type 1 diabetes. Results We observed enhanced detection sensitivity when sampling the cellular compartment compared with the non-cellular compartment of peripheral blood (OR 21.69; 95% CI 3.64, 229.20; p Conclusions/interpretation Our data indicate that, in peripheral blood, antigen-presenting cells are the predominant source of enterovirus infection, and that infection is correlated with disease stage and genetic predisposition, thereby supporting a role for enterovirus infection prior to disease onset.Peer reviewe
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