307 research outputs found

    Detection of Water Vapor in the Thermal Spectrum of the Non-Transiting Hot Jupiter upsilon Andromedae b

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    The upsilon Andromedae system was the first multi-planet system discovered orbiting a main sequence star. We describe the detection of water vapor in the atmosphere of the innermost non-transiting gas giant ups~And~b by treating the star-planet system as a spectroscopic binary with high-resolution, ground-based spectroscopy. We resolve the signal of the planet's motion and break the mass-inclination degeneracy for this non-transiting planet via deep combined flux observations of the star and the planet. In total, seven epochs of Keck NIRSPEC LL band observations, three epochs of Keck NIRSPEC short wavelength KK band observations, and three epochs of Keck NIRSPEC long wavelength KK band observations of the ups~And~system were obtained. We perform a multi-epoch cross correlation of the full data set with an atmospheric model. We measure the radial projection of the Keplerian velocity (KPK_P = 55 ±\pm 9 km/s), true mass (MbM_b = 1.7 −0.24+0.33^{+0.33}_{-0.24} MJM_J), and orbital inclination \big(ibi_b = 24 ±\pm 4∘^{\circ}\big), and determine that the planet's opacity structure is dominated by water vapor at the probed wavelengths. Dynamical simulations of the planets in the ups~And~system with these orbital elements for ups~And~b show that stable, long-term (100 Myr) orbital configurations exist. These measurements will inform future studies of the stability and evolution of the ups~And~system, as well as the atmospheric structure and composition of the hot Jupiter.Comment: Accepted to A

    High-performance liquid chromatographic determination of ibuprofen and its major metabolites in biological fluids

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    A sensitive and selective high-performance liquid-chromatographic assay for ibuprofen and its major metabolites in biological fluids is described. To ensure good chromatographic separation the drug and metabolites were run on a gradient elution system and detected with a variable wavelength detector set at 220 nm. A second, more rapid, isocratic system is also described for the detection of only ibuprofen.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23806/1/0000044.pd

    Evidence for the Direct Detection of the Thermal Spectrum of the Non-Transiting Hot Gas Giant HD 88133 b

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    We target the thermal emission spectrum of the non-transiting gas giant HD 88133 b with high-resolution near-infrared spectroscopy, by treating the planet and its host star as a spectroscopic binary. For sufficiently deep summed flux observations of the star and planet across multiple epochs, it is possible to resolve the signal of the hot gas giant's atmosphere compared to the brighter stellar spectrum, at a level consistent with the aggregate shot noise of the full data set. To do this, we first perform a principal component analysis to remove the contribution of the Earth's atmosphere to the observed spectra. Then, we use a cross-correlation analysis to tease out the spectra of the host star and HD 88133 b to determine its orbit and identify key sources of atmospheric opacity. In total, six epochs of Keck NIRSPEC L band observations and three epochs of Keck NIRSPEC K band observations of the HD 88133 system were obtained. Based on an analysis of the maximum likelihood curves calculated from the multi-epoch cross correlation of the full data set with two atmospheric models, we report the direct detection of the emission spectrum of the non-transiting exoplanet HD 88133 b and measure a radial projection of the Keplerian orbital velocity of 40 ±\pm 15 km/s, a true mass of 1.02−0.28+0.61MJ^{+0.61}_{-0.28}M_J, a nearly face-on orbital inclination of 15−5+6∘{^{+6}_{-5}}^{\circ}, and an atmosphere opacity structure at high dispersion dominated by water vapor. This, combined with eleven years of radial velocity measurements of the system, provides the most up-to-date ephemeris for HD 88133.Comment: 9 pages, 6 figures; accepted for publication in Ap

    Determination of myocardial and serum digoxin concentrations in children by specific and nonspecific assay methods

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109866/1/cptclpt198378.pd

    Ground- and Space-based Detection of the Thermal Emission Spectrum of the Transiting Hot Jupiter KELT-2Ab

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    We describe the detection of water vapor in the atmosphere of the transiting hot Jupiter KELT-2Ab by treating the star-planet system as a spectroscopic binary with high-resolution, ground-based spectroscopy. We resolve the signal of the planet's motion with deep combined flux observations of the star and the planet. In total, six epochs of Keck NIRSPEC LL-band observations were obtained, and the full data set was subjected to a cross correlation analysis with a grid of self-consistent atmospheric models. We measure a radial projection of the Keplerian velocity, KPK_P, of 148 ±\pm 7 km s−1^{-1}, consistent with transit measurements, and detect water vapor at 3.8σ\sigma. We combine NIRSPEC LL-band data with SpitzerSpitzer IRAC secondary eclipse data to further probe the metallicity and carbon-to-oxygen ratio of KELT-2Ab's atmosphere. While the NIRSPEC analysis provides few extra constraints on the SpitzerSpitzer data, it does provide roughly the same constraints on metallicity and carbon-to-oxygen ratio. This bodes well for future investigations of the atmospheres of non-transiting hot Jupiters.Comment: accepted to A

    Analysis of lesion localisation at colonoscopy: outcomes from a multi-centre U.K. study

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    Background: Colonoscopy is currently the gold standard for detection of colorectal lesions, but may be limited in anatomically localising lesions. This audit aimed to determine the accuracy of colonoscopy lesion localisation, any subsequent changes in surgical management and any potentially influencing factors. Methods: Patients undergoing colonoscopy prior to elective curative surgery for colorectal lesion/s were included from 8 registered U.K. sites (2012–2014). Three sets of data were recorded: patient factors (age, sex, BMI, screener vs. symptomatic, previous abdominal surgery); colonoscopy factors (caecal intubation, scope guide used, colonoscopist accreditation) and imaging modality. Lesion localisation was standardised with intra-operative location taken as the gold standard. Changes to surgical management were recorded. Results: 364 cases were included; majority of lesions were colonic, solitary, malignant and in symptomatic referrals. 82% patients had their lesion/s correctly located at colonoscopy. Pre-operative CT visualised lesion/s in only 73% of cases with a reduction in screening patients (64 vs. 77%; p = 0.008). 5.2% incorrectly located cases at colonoscopy underwent altered surgical management, including conversion to open. Univariate analysis found colonoscopy accreditation, scope guide use, incomplete colonoscopy and previous abdominal surgery significantly influenced lesion localisation. On multi-variate analysis, caecal intubation and scope guide use remained significant (HR 0.35, 0.20–0.60 95% CI and 0.47; 0.25–0.88, respectively). Conclusion: Lesion localisation at colonoscopy is incorrect in 18% of cases leading to potentially significant surgical management alterations. As part of accreditation, colonoscopists need lesion localisation training and awareness of when inaccuracies can occur

    Defects in nematic membranes can buckle into pseudospheres

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    A nematic membrane is a sheet with embedded orientational order, which can occur in biological cells, liquid crystal films, manufactured materials, and other soft matter systems. By formulating the free energy of nematic films using tensor contractions from differential geometry, we elucidate the elastic terms allowed by symmetry, and indicate differences from hexatic membranes. We find that topological defects in the orientation field can cause the membrane to buckle over a size set by the competition between surface tension and in-plane elasticity. In the absence of bending rigidity the resulting shape is universal, known as a parabolic pseudosphere or a revolved tractrix. Bending costs oppose such buckling and modify the shape in a predictable manner. In particular, the anisotropic rigidities of nematic membranes lead to different shapes for aster and vortex defects, in principle enabling measurement of couplings specific to nematic membranes.Comment: 9 pages, 3 figure
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