2,745 research outputs found

    A Dust Twin of Cas A: Cool Dust and 21-micron Silicate Dust Feature in the Supernova Remnant G54.1+0.3

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    We present infrared (IR) and submillimeter observations of the Crab-like supernova remnant (SNR) G54.1+0.3 including 350 micron (SHARC-II), 870 micron (LABOCA), 70, 100, 160, 250, 350, 500 micron (Herschel) and 3-40 micron (Spitzer). We detect dust features at 9, 11 and 21 micron and a long wavelength continuum dust component. The 21 micron dust coincides with [Ar II] ejecta emission, and the feature is remarkably similar to that in Cas A. The IRAC 8 micron image including Ar ejecta is distributed in a shell-like morphology which is coincident with dust features, suggesting that dust has formed in the ejecta. We create a cold dust map that shows excess emission in the northwestern shell. We fit the spectral energy distribution of the SNR using the continuous distributions of ellipsoidal (CDE) grain model of pre-solar grain SiO2 that reproduces the 21 and 9 micron dust features and discuss grains of SiC and PAH that may be responsible for the 10-13 micron dust features. To reproduce the long-wavelength continuum, we explore models consisting of different grains including Mg2SiO4, MgSiO3, Al2O3, FeS, carbon, and Fe3O4. We tested a model with a temperature-dependent silicate absorption coefficient. We detect cold dust (27-44 K) in the remnant, making this the fourth such SNR with freshly-formed dust. The total dust mass in the SNR ranges from 0.08-0.9 Msun depending on the grain composition, which is comparable to predicted masses from theoretical models. Our estimated dust masses are consistent with the idea that SNe are a significant source of dust in the early Universe.Comment: MNRAS: accepted on June 28, 2018 and published on July 4, 201

    Perceptions of the Changing Healthcare Environment: A Florida Perspective

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    This study reviewed public perceptions of healthcare, including the public’s opinions of healthcare reform. The study’s objective was to examine how opinions are affected by individual differences such as age, income, race, and current insurance. It used telephone survey responses from the citizens of Florida to provide a more empirical look at the views of the population. Overall, the study findings provided important insight into the perceptions of Floridians of important components of the Patient Protection and Affordable Care Act (ACA) including cost, affordability, Medicaid expansion, and universal access to care. The results of this study indicate that whereas income, type of insurance held, race, education, and age have some impact on response to the statements posed, party affiliation is the best indicator of individuals\u27 perceptions of the policies. In addition, results suggest that policymakers should consider more effective and targeted ACA educational campaigns for those populations that are older, more educated, and with higher incomes. They also should consider identifying and implementing opportunities to expand the Medicaid program because there is such broad support for its expansion

    The Effectiveness of the Virginia Network for Women: A Mixed Methods Study

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    Over the last 50 years, higher education institutions across the country have experienced growth in enrollment and degree attainment by women. However, despite the increase in educational merit, the representation of women in administrative and leadership roles within higher education is still not equitable to that of men. The Women’s Network, a non-profit subsidiary of the American Council on Education’s Inclusive Excellence Group, aims to identify, develop, advance, and support women in higher education at the local, state, and national levels. The Virginia Network is a state constituency of the Women’s Network that promotes women’s leadership in higher education throughout the Commonwealth of Virginia. This exploratory mixed methods study explored the needs of women in the Commonwealth of Virginia and the ways in which the Virginia Network could support those needs. Using social justice leadership theory and process evaluation frameworks, qualitative and quantitative data were collected and analyzed to answer the study’s research questions. Data was analyzed through thematic coding and statistical analysis. This study\u27s findings inform how the Virginia Network can enhance current programming and develop new programming to addresses the needs and barriers identified and experienced by women across the Commonwealth

    Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

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    Fundamental to the synthesis of enantioenriched chiral molecules is the ability to assign absolute configuration at each stereogenic center, and to determine the enantiomeric excess for each compound. While determination of enantiomeric excess and absolute configuration is often considered routine in many facets of asymmetric synthesis, the same determinations for enantioisotopomers remains a formidable challenge. Here, we report the first highly enantioselective metal-catalyzed synthesis of enantioisotopomers that are chiral by virtue of deuterium substitution along with the first general spectroscopic technique for assignment of the absolute configuration and quantitative determination of the enantiomeric excess of isotopically chiral molecules. Chiral tag rotational spectroscopy uses noncovalent chiral derivatization, which eliminates the possibility of racemization during derivatization, to perform the chiral analysis without the need of reference samples oft he enantioisotopomer

    1994-95 Advisory Council On Social Security Technical Panel on Trends and Issues in Retirement Saving Final Report

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    The charge of the Technical Panel on Trends and Issues in Retirement Savings (TIRS) was to assist the 1994-95 [Social Security] Advisory Council with respect to its charge to analyze the relative roles of the public and private sectors in the provision of retirement income, particularly how underlying policies of public and private programs, including relevant tax laws, affect retirement decisions and the economic status of the elderly

    Linking protein to phenotype with Mendelian Randomization detects 38 proteins with causal roles in human diseases and traits

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    To efficiently transform genetic associations into drug targets requires evidence that a particular gene, and its encoded protein, contribute causally to a disease. To achieve this, we employ a three-step proteome-by-phenome Mendelian Randomization (MR) approach. In step one, 154 protein quantitative trait loci (pQTLs) were identified and independently replicated. From these pQTLs, 64 replicated locally-acting variants were used as instrumental variables for proteome-by-phenome MR across 846 traits (step two). When its assumptions are met, proteome-by-phenome MR, is equivalent to simultaneously running many randomized controlled trials. Step 2 yielded 38 proteins that significantly predicted variation in traits and diseases in 509 instances. Step 3 revealed that amongst the 271 instances from GeneAtlas (UK Biobank), 77 showed little evidence of pleiotropy (HEIDI), and 92 evidence of colocalization (eCAVIAR). Results were wide ranging: including, for example, new evidence for a causal role of tyrosine-protein phosphatase non-receptor type substrate 1 (SHPS1; SIRPA) in schizophrenia, and a new finding that intestinal fatty acid binding protein (FABP2) abundance contributes to the pathogenesis of cardiovascular disease. We also demonstrated confirmatory evidence for the causal role of four further proteins (FGF5, IL6R, LPL, LTA) in cardiovascular disease risk

    Search for the standard model Higgs boson decaying to a bbˉb\bar{b} pair in events with no charged leptons and large missing transverse energy using the full CDF data set

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    We report on a search for the standard model Higgs boson produced in association with a vector boson in the full data set of proton-antiproton collisions at s=1.96\sqrt{s} = 1.96 TeV recorded by the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45 fb1^{-1}. We consider events having no identified charged lepton, a transverse energy imbalance, and two or three jets, of which at least one is consistent with originating from the decay of a bb quark. We place 95% credibility level upper limits on the production cross section times standard model branching fraction for several mass hypotheses between 90 and 150GeV/c2150 \mathrm{GeV}/c^2. For a Higgs boson mass of 125GeV/c2125 \mathrm{GeV}/c^2, the observed (expected) limit is 6.7 (3.6) times the standard model prediction.Comment: Accepted by Phys. Rev. Let
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