2,968 research outputs found

    Dynamics of Oxygen Demand Within the Middle and Lower Savannah River Basins

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    2010 S.C. Water Resources Conference - Science and Policy Challenges for a Sustainable Futur

    Charge-state distribution of Li ions from the β\beta decay of laser-trapped 6^{6}He atoms

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    Background: The accurate determination of atomic final states following nuclear β\beta decay plays an important role in many experiments. In particular, the charge state distributions of ions following nuclear β\beta decay are important for determinations of the βν\beta-\nu angular correlation with improved precision. Purpose: Our measurement aims at providing benchmarks to test theoretical calculations. Method: The kinematics of Lin+^{n+} ions produced following the β\beta decay of 6He^6{\rm He} within an electric field were measured using 6He^6{\rm He} atoms in the metastable (1s2s, 3S1)(1s2s,~{^3S_1}) and in the (1s2p, 3P2)(1s2p,~{^3P_2}) states confined by a magneto-optical trap. The electron shake-off probabilities were deduced including their dependence on ion energy. Results: We find significant discrepancies on the fractions of Li ions in the different charge states with respect to a recent calculation and discuss a plausible explanation. We also point out that there is no explanation for a large discrepancy between the same calculation and a previous measurement of the Li-ion energy dependence of the charge distribution from decays of the electronic ground state

    1935: Abilene Christian College Bible Lectures - Full Text

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    Delivered in the auditorium of Abilene Christian College, Abilene, Texas, February 193

    EPIC 219388192 b - an inhabitant of the brown dwarf desert in the Ruprecht 147 open cluster

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    We report the discovery of EPIC 219388192 b, a transiting brown dwarf in a 5.3-day orbit around a member star of Ruprecht-147, the oldest nearby open cluster association, which was photometrically monitored by K2 during its Campaign 7. We combine the K2 time-series data with ground-based adaptive optics imaging and high resolution spectroscopy to rule out false positive scenarios and determine the main parameters of the system. EPIC 219388192 b has a radius of RbR_\mathrm{b}=0.937±0.0420.937\pm0.042~RJup\mathrm{R_{Jup}} and mass of MbM_\mathrm{b}=36.50±0.0936.50\pm0.09~MJup\mathrm{M_{Jup}}, yielding a mean density of 59.0±8.159.0\pm8.1~gcm3\mathrm{g\,cm^{-3}}. The host star is nearly a Solar twin with mass MM_\star=0.99±0.050.99\pm0.05~M\mathrm{M_{\odot}}, radius RR_\star=1.01±0.041.01\pm0.04~R\mathrm{R_{\odot}}, effective temperature Teff\mathrm{T_{eff}}=5850±855850\pm85~K and iron abundance [Fe/H]=0.03±0.080.03\pm0.08~dex. Its age, spectroscopic distance, and reddening are consistent with those of Ruprecht-147, corroborating its cluster membership. EPIC 219388192 b is the first brown dwarf with precise determinations of mass, radius and age, and serves as benchmark for evolutionary models in the sub-stellar regime.Comment: 13 pages, 11 figures, 4 tables, submitted to AAS Journal

    Three Small Planets Transiting a Hyades Star

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    We present the discovery of three small planets transiting K2-136 (LP 358 348, EPIC 247589423), a late K dwarf in the Hyades. The planets have orbital periods of 7.9757±0.00117.9757 \pm 0.0011, 17.306810.00036+0.0003417.30681^{+0.00034}_{-0.00036}, and 25.57150.0040+0.003825.5715^{+0.0038}_{-0.0040} days, and radii of 1.05±0.161.05 \pm 0.16, 3.14±0.363.14 \pm 0.36, and 1.550.21+0.241.55^{+0.24}_{-0.21} RR_\oplus, respectively. With an age of 600-800 Myr, these planets are some of the smallest and youngest transiting planets known. Due to the relatively bright (J=9.1) host star, the planets are compelling targets for future characterization via radial velocity mass measurements and transmission spectroscopy. As the first known star with multiple transiting planets in a cluster, the system should be helpful for testing theories of planet formation and migration.Comment: Accepted to The Astronomical Journa

    Exoplanets around Low-mass Stars Unveiled by K2

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    We present the detection and follow-up observations of planetary candidates around low-mass stars observed by the K2 mission. Based on light-curve analysis, adaptive-optics imaging, and optical spectroscopy at low and high resolution (including radial velocity measurements), we validate 16 planets around 12 low-mass stars observed during K2 campaigns 5-10. Among the 16 planets, 12 are newly validated, with orbital periods ranging from 0.96-33 days. For one of the planets (K2-151b) we present ground-based transit photometry, allowing us to refine the ephemerides. Combining our K2 M-dwarf planets together with the validated or confirmed planets found previously, we investigate the dependence of planet radius RpR_p on stellar insolation and metallicity [Fe/H]. We confirm that for periods P2P\lesssim 2 days, planets with a radius Rp2RR_p\gtrsim 2\,R_\oplus are less common than planets with a radius between 1-2R\,R_\oplus. We also see a hint of the "radius valley" between 1.5 and 2R\,R_\oplus that has been seen for close-in planets around FGK stars. These features in the radius/period distribution could be attributed to photoevaporation of planetary envelopes by high-energy photons from the host star, as they have for FGK stars. For the M dwarfs, though, the features are not as well defined, and we cannot rule out other explanations such as atmospheric loss from internal planetary heat sources, or truncation of the protoplanetary disk. There also appears to be a relation between planet size and metallicity: those few planets larger than about 3 RR_\oplus are found around the most metal-rich M dwarfs.Comment: 29 pages, 21 figures, 6 tables, Accepted in Astronomical Journa

    Cellular responses of Candida albicans to phagocytosis and the extracellular activities of neutrophils are critical to counteract carbohydrate starvation, oxidative and nitrosative stress

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    Acknowledgments We thank Alexander Johnson (yhb1D/D), Karl Kuchler (sodD/D mutants), Janet Quinn (hog1D/D, hog1/cap1D/D, trx1D/D) and Peter Staib (ssu1D/D) for providing mutant strains. We acknowledge helpful discussions with our colleagues from the Microbial Pathogenicity Mechanisms Department, Fungal Septomics and the Microbial Biochemistry and Physiology Research Group at the Hans Kno¨ll Institute (HKI), specially Ilse D. Jacobsen, Duncan Wilson, Sascha Brunke, Lydia Kasper, Franziska Gerwien, Sea´na Duggan, Katrin Haupt, Kerstin Hu¨nniger, and Matthias Brock, as well as from our partners in the FINSysB Network. Author Contributions Conceived and designed the experiments: PM HW IMB AJPB OK BH. Performed the experiments: PM CD HW. Analyzed the data: PM HW IMB AJPB OK BH. Wrote the paper: PM HW OK AJPB BH.Peer reviewedPublisher PD

    A systematic, intensive statistical investigation of data from the Comprehensive Analysis of Reported Drugs (CARD) for compliance and illicit opioid abstinence in substance addiction treatment with buprenorphine/naloxone

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    BACKGROUND: Buprenorphine and naloxone (bup/nal), a combination partial mu receptor agonist and low-dose delta mu antagonist, is presently recommended and used to treat opioid-use disorder. However, a literature review revealed a paucity of research involving data from urine drug tests that looked at compliance and abstinence in one sample. METHOD: Statistical analysis of data from the Comprehensive Analysis of Reported Drugs (CARD) was used to assess compliance and abstinence during treatment in a large cohort of bup/nal patients attending chemical-dependency programs from eastern USA in 2010 and 2011. RESULTS: Part 1: Bup/nal was present in 93.4% of first (n = 1,282; p \u3c.0001) and 92.4% of last (n = 1,268; p \u3c.0001) urine samples. Concomitantly, unreported illicit drugs were present in 47.7% (n = 655, p =.0261) of samples. Patients who were compliant to the bup/nal prescription were more likely than noncompliant patients to be abstinent during treatment (p =.0012; odds ratio = 1.69 with 95% confidence interval (1.210, 2.354). Part 2: An analysis of all samples collected in 2011 revealed a significant improvement in both compliance (p \u3c 2.2 × 1
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