1,775 research outputs found

    Georgia: Individual State Report - State-level Field Network Study of the Implementation of the Affordable Care Act

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    This report is part of a series of 21 state and regional studies examining the rollout of the ACA. The national network -- with 36 states and 61 researchers -- is led by the Rockefeller Institute of Government, the public policy research arm of the State University of New York, the Brookings Institution, and the Fels Institute of Government at the University of Pennsylvania.According to the report, much of the reduction in Georgia's uninsured population can be attributed to the extensive education and outreach efforts that were carried out by a variety of nonprofit and community-based organizations. Many media organizations also played a role through various public information activities and their extensive coverage of the eligibility requirements, the process for signing up for coverage through the federal health insurance marketplace, and opportunities for obtaining consumer assistance with the enrollment process.Unlike many other states that embraced a more positive response to health reform, Georgia's state government did not engage in any formal education, public information, or outreach activities to assist eligible low-income households in connecting to the most appropriate health insurance plan for their needs and circumstances through the marketplace. The report concludes that while notable gains were made in extending health care coverage to the uninsured during the first two enrollment periods, given the size of Georgia's "coverage gap," further reductions in the state's uninsured population will likely depend on state officials crafting an alternative to Medicaid expansion acceptable to the state's political leadership

    Revised metallicity classes for low-mass stars: dwarfs (dM), subdwarfs (sdM), extreme subdwarfs (esdM), and ultra subdwarfs (usdM)

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    The current classification system of M stars on the main sequence distinguishes three metallicity classes (dwarfs - dM, subdwarfs - sdM, and extreme subdwarfs - esdM). The spectroscopic definition of these classes is based on the relative strength of prominent CaH and TiO molecular absorption bands near 7000A, as quantified by three spectroscopic indices (CaH2, CaH3, and TiO5). We re-examine this classification system in light of our ongoing spectroscopic survey of stars with proper motion \mu > 0.45 "/yr, which has increased the census of spectroscopically identified metal-poor M stars to over 400 objects. Kinematic separation of disk dwarfs and halo subdwarfs suggest deficiencies in the current classification system. Observations of common proper motion doubles indicates that the current dM/sdM and sdM/esdM boundaries in the [TiO5,CaH2+CaH3] index plane do not follow iso-metallicity contours, leaving some binaries inappropriately classified as dM+sdM or sdM+esdM. We propose a revision of the classification system based on an empirical calibration of the TiO/CaH ratio for stars of near solar metallicity. We introduce the parameter \zeta_{TiO/CaH} which quantifies the weakening of the TiO bandstrength due to metallicity effect, with values ranging from \zeta_{TiO/CaH}=1 for stars of near-solar metallicity to \zeta_{TiO/CaH}~0 for the most metal-poor (and TiO depleted) subdwarfs. We redefine the metallicity classes based on the value of the parameter \zeta_{TiO/CaH}; and refine the scheme by introducing an additional class of ultra subdwarfs (usdM). We introduce sequences of sdM, esdM, and usdM stars to be used as formal classification standards.Comment: 15 pages, accepted for publication in the Astrophysical Journa

    Galaxy mergers drive shocks: An integral field study of goals galaxies

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    We present an integral field spectroscopic study of radiative shocks in 27 nearby ultraluminous and luminous infrared galaxies (U/LIRGs) from the Great Observatory All-sky LIRG Survey, a subset of the Revised Bright Galaxy Sample. Our analysis of the resolved spectroscopic data from the Wide Field Spectrograph focuses on determining the detailed properties of the emission-line gas, including a careful treatment of multicomponent emission-line profiles. The resulting information obtained from the spectral fits is used to map the kinematics of the gas, sources of ionizing radiation, and feedback present in each system. The resulting properties are tracked as a function of merger stage. Using emission-line flux ratios and velocity dispersions, we find evidence for widespread, extended shock excitation in many local U/LIRGs. These low-velocity shocks become an increasingly important component of the optical emission lines as a merger progresses. We find that shocks may account for as much as half of the Hα luminosity in the latest-stage mergers in our sample. We discuss some possible implications of our result and consider the presence of active galactic nuclei and their effects on the spectra in our sample

    Composite spectra in merging U/LIRGs caused by shocks

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    We present a key result from our optical integral field spectroscopic survey of 27 nearby ultraluminous and luminous infrared galaxies (U/LIRGs) from the Great Observatory All-Sky LIRG Survey. Using spatially resolved multi-component emission line fittin

    Muscle Nicotinic Acetylcholine Receptors May Mediate Trans-Synaptic Signaling at the Mouse Neuromuscular Junction

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    Block of neurotransmitter receptors at the neuromuscular junction (NMJ) has been shown to trigger upregulation of the number of synaptic vesicles released (quantal content, QC), a response termed homeostatic synaptic plasticity. The mechanism underlying this plasticity is not known. Here, we used selective toxins to demonstrate that block of α1-containing nicotinic acetylcholine receptors (nAChRs) at the NMJ of male and female mice triggers the upregulation of QC. Reduction of current flow through nAChRs, induced by drugs with antagonist activity, demonstrated that reduction in synaptic current per se does not trigger upregulation of QC. These data led to the remarkable conclusion that disruption of synaptic transmission is not sensed to trigger upregulation of QC. During studies of the effect of partial block of nAChRs on QC, we observed a small but reproducible increase in the decay kinetics of miniature synaptic currents. The change in kinetics was correlated with the increase in QC and raises the possibility that a change in postsynaptic nAChR conformation may be associated with the presynaptic increase in QC. We propose that, in addition to functioning in synaptic transmission, ionotropic muscle nicotonic nAChRs may serve as signaling molecules that participate in synaptic plasticity. Because nAChRs have been implicated in a number of disease states, the finding that nAChRs may be involved in triggering synaptic plasticity could have wide-reaching implications. SIGNIFICANCE STATEMENT The signals that initiate synaptic plasticity of the nervous system are still incompletely understood. Using the mouse neuromuscular junction as a model synapse, we studied how block of neurotransmitter receptors is sensed to trigger synaptic plasticity. Our studies led to the surprising conclusion that neither changes in synaptic current nor spiking of the presynaptic or postsynaptic cell are sensed to initiate synaptic plasticity. Instead, postsynaptic nicotinic acetylcholine receptors (nAChRs), in addition to functioning in synaptic transmission, may serve as signaling molecules that trigger synaptic plasticity. Because nAChRs have been implicated in a number of disease states, the finding that they may mediate synaptic plasticity has broad implications

    The association of preoperative cardiac stress testing with 30-day death and myocardial infarction among patients undergoing kidney transplantation

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    BACKGROUND:Although periodic cardiac stress testing is commonly used to screen patients on the waiting list for kidney transplantation for ischemic heart disease, there is little evidence to support this practice. We hypothesized that cardiac stress testing in the 18 months prior to kidney transplantation would not reduce postoperative death, total myocardial infarction (MI) or fatal MI. METHODS:Using the United States Renal Data System, we identified ESRD patients ≥40 years old with primary Medicare insurance who received their first kidney transplant between 7/1/2006 and 11/31/2013. Propensity matching created a 1:1 matched sample of patients with and without stress testing in the 18 months prior to kidney transplantation. The outcomes of interest were death, total (fatal and nonfatal) MI or fatal MI within 30 days of kidney transplantation. RESULTS:In the propensity-matched cohort of 17,304 patients, death within 30 days occurred in 72 of 8,652 (0.83%) patients who underwent stress testing and in 65 of 8,652 (0.75%) patients who did not (OR 1.07; 95% CI: 0.79-1.45; P = 0.66). MI within 30 days occurred in 339 (3.9%) patients who had a stress test and in 333 (3.8%) patients who did not (OR 1.03; 95% CI: 0.89-1.21; P = 0.68). Fatal MI occurred in 17 (0.20%) patients who underwent stress testing and 15 (0.17%) patients who did not (OR 0.97; 95% CI: 0.71-1.32; P = 0.84). CONCLUSION:Stress testing in the 18 months prior to kidney transplantation is not associated with a reduction in death, total MI or fatal MI within 30 days of kidney transplantation

    HST/NICMOS Observations of Massive Stellar Clusters Near the Galactic Center

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    We report Hubble Space Telescope (HST) Near-infrared Camera and Multi-object Spectrometer (NICMOS) observations of the Arches and Quintuplet clusters, two extraordinary young clusters near the Galactic Center. For the first time, we have identified main sequence stars in the Galactic Center with initial masses well below 10 Msun. We present the first determination of the initial mass function (IMF) for any population in the Galactic Center, finding an IMF slope which is significantly more positive (Gamma approx -0.65) than the average for young clusters elsewhere in the Galaxy (Gamma approx -1.4). The apparent turnoffs in the color-magnitude diagrams suggest cluster ages which are consistent with the ages implied by the mixture of spectral types in the clusters; we find tau(age) approx 2+/-1 Myr for the Arches cluster, and tau(age) approx 4+/-1 Myr for the Quintuplet. We estimate total cluster masses by adding the masses of observed stars down to the 50% completeness limit, and then extrapolating down to a lower mass cutoff of 1 Msun. Using this method, we find > 10^4 Msun for the total mass of the Arches cluster. Such a determination for the Quintuplet cluster is complicated by the double-valued mass-magnitude relationship for clusters with ages > 3 Myr. We find a lower limit of 6300 Msun for the total cluster mass, and suggest a best estimate of twice this value which accounts for the outlying members of the cluster. Both clusters have masses which place them as the two most massive clusters in the Galaxy.Comment: accepted by ApJ higher resolution versions of figures 1 and 2 can be found at: ftp://quintup.astro.ucla.edu/nicmos1
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