4,450 research outputs found

    Estimating χtop\chi_\mathrm{top} Lattice Artifacts from Flowed SU(2) Calorons

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    Lattice computations of the high-temperature topological susceptibility of QCD receive lattice-spacing corrections and suffer from systematics arising from the type and depth of gradient flow. We study the lattice spacing corrections to χtop\chi_\mathrm{top} semi-analytically by exploring the behavior of discretized Harrington-Shepard calorons under the action of different forms of gradient flow. From our study we conclude that Nτ=6N_\tau = 6 is definitely too small of a time extent to study the theory at temperatures of order 4 Tc4~T_\mathrm{c} and we explore how the amount of gradient flow influences the continuum extrapolation.Comment: 10 pages, 8 figures (published version

    Transient elevated serum prolactin in trans women is caused by cyproterone acetate treatment

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    Purpose: Hormone treatment in trans women in Europe usually consists of the administration of estrogens and antiandrogens, for example, cyproterone acetate (CPA). Mild serum prolactin elevations during follow-up are attributed to estrogen therapy. This analysis evaluates whether CPA contributes to the elevation of prolactin in trans women receiving gender affirming hormones. Methods: This study is part of the endocrine part of the European Network for the Investigation of Gender Incongruence (ENIGI). Belgian data were selected for this substudy. Trans women who initiated gender affirming hormone treatment and underwent orchiectomy were prospectively evaluated. Trans women were treated with oral CPA 50 mg in combination with estrogen substitution. Postsurgery, estrogen was reinitiated in an unchanged dose. Sex steroids, gonadotropins, and prolactin were compared at baseline, pre- and postsurgery in patients receiving orchiectomy, and at baseline, 12, and 18 months in patients who did not undergo orchiectomy. Results: One hundred and seven trans women participated in this analysis, with a mean age of 31.5 years. An increase in serum prolactin levels was seen in the group undergoing orchiectomy (23.72 mu g/L) and not undergoing orchiectomy (23.05 mu g/L) at the preoperative and 12-month visit, compared with baseline (9.42 mu g/L, P = 0.002 and 9.94 mu g/L, P < 0.001, respectively). After orchiectomy, a decline in prolactin levels (10.17 mu g/L, P < 0.001) occurred. Conclusions: CPA is likely to cause a temporary increase in serum prolactin, with prolactin levels returning to normal after orchiectomy and CPA discontinuation

    A new liver perfusion and preservation system for transplantation Research in large animals

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    A kidney perfusion machine, model MOX-100 (Waters Instruments, Ltd, Rochester, MN) was modified to allow continuous perfusion of the portal vein and pulsatile perfusion of the hepatic artery of the liver. Additional apparatus consists of a cooling system, a membrane oxygenator, a filter for foreign bodies, and bubble traps. This system not only allows hypothermic perfusion preservation of the liver graft, but furthermore enables investigation of ex vivo simulation of various circulatory circumstances in which physiological perfusion of the liver is studied. We have used this system to evaluate the viability of liver allografts preserved by cold storage. The liver was placed on the perfusion system and perfused with blood with a hematocrit of approximately 20% and maintained at 37°C for 3 h. The flows of the hepatic artery and portal vein were adjusted to 0.33 mL and 0.67 mL/g of liver tissue, respectively. Parameters of viability consisted of hourly bile output, oxygen consumption, liver enzymes, electrolytes, vascular resistance, and liver histology. This method of liver assessment in large animals will allow the objective evaluation of organ viability for transplantation and thereby improve the outcome of organ transplantation. Furthermore, this pump enables investigation into the pathophysiology of liver ischemia and preservation. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted

    SMASHing the LMC: A Tidally-induced Warp in the Outer LMC and a Large-scale Reddening Map

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    We present a study of the three-dimensional (3D) structure of the Large Magellanic Cloud (LMC) using ~2.2 million red clump (RC) stars selected from the Survey of the MAgellanic Stellar History. To correct for line-of-sight dust extinction, the intrinsic RC color and magnitude and their radial dependence are carefully measured by using internal nearly dust-free regions. These are then used to construct an accurate 2D reddening map (165 square degrees with ~10 arcmin resolution) of the LMC disk and the 3D spatial distribution of RC stars. An inclined disk model is fit to the 2D distance map yielding a best-fit inclination angle i = 25.86(+0.73,-1.39) degrees with random errors of +\-0.19 degrees and line-of-nodes position angle theta = 149.23(+6.43,-8.35) degrees with random errors of +/-0.49 degrees. These angles vary with galactic radius, indicating that the LMC disk is warped and twisted likely due to the repeated tidal interactions with the Small Magellanic Cloud (SMC). For the first time, our data reveal a significant warp in the southwestern part of the outer disk starting at rho ~ 7 degrees that departs from the defined LMC plane up to ~4 kpc toward the SMC, suggesting that it originated from a strong interaction with the SMC. In addition, the inner disk encompassing the off-centered bar appears to be tilted up to 5-15 degrees relative to the rest of the LMC disk. These findings on the outer warp and the tilted bar are consistent with the predictions from the Besla et al. simulation of a recent direct collision with the SMC.Comment: 25 pages, 15 figures, published in Ap

    Catalytic enantioselective [2,3]-rearrangements of allylic ammonium ylides : a mechanistic and computational study

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    The research leading to these results (T. H. W., J. E. T., G. C. L.-J. and A.D.S) has received funding from the ERC under the European Union's Seventh Framework Programme (FP7/2007-2013) / E.R.C. grant agreements n° 279850 and n° 340163. A.D.S. thanks the Royal Society for a Wolfson Research Merit Award. P.H.-Y.C. is the Bert and Emelyn Christensen Professor and gratefully acknowledges financial support from the Stone Family of OSU. Financial support from the National Science Foundation (NSF) (CHE-1352663) is acknowledged. D.M.W. acknowledges the Bruce Graham and Johnson Fellowships of OSU. A.C.B. acknowledges the Johnson Fellowship of OSU. D.M.W., A.C.B., and R.C.J. and P.H.-Y.C. also acknowledge computing infrastructure in part provided by the NSF Phase2 CCI, Center for Sustainable Materials Chemistry (CHE1102637).A mechanistic study of the isothiourea-catalyzed enantioselective [2,3]-rearrangement of allylic ammonium ylides is described. Reaction kinetic analyses using 19F NMR and density functional theory computations have elucidated a reaction profile and allowed identification of the catalyst resting state and turnover-rate limiting step. A catalytically-relevant catalyst-substrate adduct has been observed, and its constitution elucidated unambiguously by 13C and 15N isotopic labeling. Isotopic entrainment has shown the observed catalyst-substrate adduct to be a genuine intermediate on the productive cycle towards catalysis. The influence of HOBt as an additive upon the reaction, catalyst resting state, and turnover-rate limiting step has been examined. Crossover experiments have probed the reversibility of each of the proposed steps of the catalytic cycle. Computations were also used to elucidate the origins of stereocontrol, with a 1,5-S•••O interaction and the catalyst stereodirecting group providing transition structure rigidification and enantioselectivity, while preference for cation-π interactions over C-H•••π is responsible for diastereoselectivity.Peer reviewe

    Further Sunyaev-Zel'dovich observations of two Planck ERCSC clusters with the Arcminute Microkelvin Imager

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    We present follow-up observations of two galaxy clusters detected blindly via the Sunyaev-Zel'dovich (SZ) effect and released in the Planck Early Release Compact Source Catalogue. We use the Arcminute Microkelvin Imager, a dual-array 14-18 GHz radio interferometer. After radio source subtraction, we find a SZ decrement of integrated flux density -1.08+/-0.10 mJy toward PLCKESZ G121.11+57.01, and improve the position measurement of the cluster, finding the centre to be RA 12 59 36.4, Dec +60 04 46.8, to an accuracy of 20 arcseconds. The region of PLCKESZ G115.71+17.52 contains strong extended emission, so we are unable to confirm the presence of this cluster via the SZ effect.Comment: 4 tables, 3 figures, revised after referee's comments and resubmitted to MNRA

    Host Galaxies of Type Ia Supernovae from the Nearby Supernova Factory

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    We present photometric and spectroscopic observations of galaxies hosting Type Ia supernovae (SNe Ia) observed by the Nearby Supernova Factory (SNfactory). Combining GALEX UV data with optical and near infrared photometry, we employ stellar population synthesis techniques to measure SN Ia host galaxy stellar masses, star-formation rates (SFRs), and reddening due to dust. We reinforce the key role of GALEX UV data in deriving accurate estimates of galaxy SFRs and dust extinction. Optical spectra of SN Ia host galaxies are fitted simultaneously for their stellar continua and emission lines fluxes, from which we derive high precision redshifts, gas-phase metallicities, and Halpha-based SFRs. With these data we show that SN Ia host galaxies present tight agreement with the fiducial galaxy mass-metallicity relation from SDSS for stellar masses log(M_*/M_Sun)>8.5 where the relation is well-defined. The star-formation activity of SN Ia host galaxies is consistent with a sample of comparable SDSS field galaxies, though this comparison is limited by systematic uncertainties in SFR measurements. Our analysis indicates that SN Ia host galaxies are, on average, typical representatives of normal field galaxies.Comment: 25 pages, 13 figures, accepted for publication in Ap

    Measuring cosmic bulk flows with Type Ia Supernovae from the Nearby Supernova Factory

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    Context. Our Local Group of galaxies appears to be moving relative to the cosmic microwave background with the source of the peculiar motion still uncertain. While in the past this has been studied mostly using galaxies as distance indicators, the weight of type Ia supernovae (SNe Ia) has increased recently with the continuously improving statistics of available low-redshift supernovae. Aims. We measured the bulk flow in the nearby universe (0.015<z<0.10.015 < z < 0.1) using 117 SNe Ia observed by the Nearby Supernova Factory, as well as the Union2 compilation of SN Ia data already in the literature. Methods. The bulk flow velocity was determined from SN data binned in redshift shells by including a coherent motion (dipole) in a cosmological fit. Additionally, a method of spatially smoothing the Hubble residuals was used to verify the results of the dipole fit. To constrain the location and mass of a potential mass concentration (e.g., the Shapley supercluster) responsible for the peculiar motion, we fit a Hubble law modified by adding an additional mass concentration. Results. The analysis shows a bulk flow that is consistent with the direction of the CMB dipole up to z0.06z \sim 0.06, thereby doubling the volume over which conventional distance measures are sensitive to a bulk flow. We see no significant turnover behind the center of the Shapley supercluster. A simple attractor model in the proximity of the Shapley supercluster is only marginally consistent with our data, suggesting the need for another, more distant source. In the redshift shell 0.06<z<0.10.06 < z < 0.1, we constrain the bulk flow velocity to <240 km s1< 240~\textrm{km s}^{-1} (68% confidence level) for the direction of the CMB dipole, in contradiction to recent claims of the existence of a large-amplitude dark flow.Comment: 12 pages, 5 figures, added corrigendum (http://adsabs.harvard.edu/abs/2015A%26A...578C...1F

    AMI observations of unmatched Planck ERCSC LFI sources at 15.75 GHz

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    The Planck Early Release Compact Source Catalogue includes 26 sources with no obvious matches in other radio catalogues (of primarily extragalactic sources). Here we present observations made with the Arcminute Microkelvin Imager Small Array (AMI SA) at 15.75 GHz of the eight of the unmatched sources at declination > +10 degrees. Of the eight, four are detected and are associated with known objects. The other four are not detected with the AMI SA, and are thought to be spurious.Comment: 6 pages, 5 figures, 4 table
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