58 research outputs found

    Effect of indomethacin and adrenocorticotrophic hormone on renal function in man: An experimental model of inappropriate antidiuresis

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    Effect of indomethacin and adrenocorticotrophic hormone on renal function in man: An experimental model of inappropriate antidiuresis. The effect of prostaglandin synthesis inhibition on basal and ACTH-stimulated adrenal and renal function was investigated in normai volunteers. Data were collected during control and experimental study periods (13 days each). Adrenocorticotrophic hormone (Cosyntropin, 80 U/day) was administered i.v. on days 8 and 9 of each period. Indomethacin (150 mg/day) was given on days 5 through 13 of the experimental period. The subjects ate a constant diet containing 9 mEq of sodium, 100 mEq of potassium, and 2,500 ml of fluid daily. Indomethacin markedly inhibited urinary PGE excretion and plasma PGE concentration. The effect of ACTH alone as compared to the effect of ACTH and indomethacin showed: plasma sodium concentration, 139 ± 1 vs. 131 ± 3 mEg/liter (P < 0.01, mean ± SEM); plasma osmolality, 287 ± 3 vs. 270 ± 3 mOsm/liter (P < 0.01); free water clearance, 97 ± 66 vs. -1100 ± 380 ml/24hr (P < 0.01); urine volume, 2,000 ± 60 vs. 950 ± 200 ml/day (P < 0.01); and urine osmolality 282 ± 12 vs. 720 ± 144 mOsm/liter (P < 0.01). We conclude that the effects of ACTH and prostaglandin synthesis inhibition interact to result in inappropriate antidiuresis.Effet de l'indométhacine et de l'hormone adrénocorticotrope sur la fonction rénale chez l'homme: Un modèle expérimental d'antidiurèse inappropriée. L'effet de l'inhibition de la synthèse de prostaglandine sur la fonction surrénalienne basale et stimulée par l'ACTH et sur la fonction rénale a été étudié chez des sujets normaux volontaires. Les résultats ont été obtenus au cours de périodes contrôles et expérimentales de 13 jours chacune. De l'hormone adrénocorticotrope (Cosyntropin) a été administrée par voie i.v. les 8ème et 9ème jours de chaque période à raison de 80 U par jour. L'indométhacine, 150 mg/jour, a été donnée du 8ème au 13ème jour de la période expérimentale. Les sujets ont été soumis à un régime constant contenant 9 mEq de sodium, 100 mEq de potassium, et 2,500 ml de liquide par jour. L'indométhacine a fortement inhibé l'excrétion urinaire de PGE et abaissé la concentration plasmatique de PGE. L'effet de l'ACTH seul comparé à l'effet de l'ACTH associé à l'indométhacine a montré: une concentration plasmatique de sodium de 139 ± 1 vs. 131 ± 3 mEq/litre (P < 0,01) moyenne et SEM); une osmolalité plasmatique de 287 ± 3 vs. 270 ± 3 mOsm/litre (P < 0,01); une clearance de l'eau libre de 97 ± 66 vs. - 1100 ± 380 ml/24 hr (P < 0,01); un débit urinaire de 2,000 ± 60 vs. 950 ± 200 ml/jour (P < 0,01); et une osmolalité urinaire de 282 ± 12 vs. 720 ± 144 mOsm/litre (P < 0,01). Nous considérons que les effets de l'ACTH et de l'inhibition de la synthèse de prostaglandine se combinent pour déterminer une antidiurése inappropriée

    The Search for Gravitational Waves

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    Experiments aimed at searching for gravitational waves from astrophysical sources have been under development for the last 40 years, but only now are sensitivities reaching the level where there is a real possibility of detections being made within the next five years. In this article a history of detector development will be followed by a description of current detectors such as LIGO, VIRGO, GEO 600, TAMA 300, Nautilus and Auriga. Preliminary results from these detectors will be discussed and related to predicted detection rates for some types of sources. Experimental challenges for detector design are introduced and discussed in the context of detector developments for the future.Comment: 21 pages, 7 figures, accepted J. Phys. B: At. Mol. Opt. Phy

    The Science of Pronominal Usage: He and It in Co-Reference to Inanimate Objects in Late Middle English Texts on Alchemy

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    This is the author's accepted manuscript. The published version can be found at http://dx.doi.org/10.1177/0075424210384225This article explores the variation between he and it in coreference to inanimate entities (such as mercury, sulfur, and salt). Using alchemical texts from the fifteenth century as material, the article demonstrates that there was much more variation in pronominal reference in this period than has previously been shown. Of the possible explanations suggested by previous research, the earlier grammatical gender system and transference from Latin do not seem to play a role, while pronoun clustering and pronominal reanalysis appear to influence the quantitative distribution. The scale of individuation used by Siemund and Stenroos to explain similar usage is shown not to be a straightforward predictor. Other factors such as personification and perceived similarities between animate and inanimate entities may affect the degree of perceived individuation. The choice of he over she seems to be influenced by pronominal reanalysis and straightforward personification in some cases. In other instances, it is speculated that the he usage reflects (stereotypical) gender conceptions in the Middle Ages

    Methods and results of a search for gravitational waves associated with gamma-ray bursts using the GEO 600, LIGO, and Virgo detectors

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    Paper producido por "The LIGO Scientific Collaboration and the Virgo Collaboration". (En el registro se mencionan solo algunos autores de las decenas de personas que participan).In this paper we report on a search for short-duration gravitational wave bursts in the frequency range 64 Hz–1792 Hz associated with gamma-ray bursts (GRBs), using data from GEO 600 and one of the LIGO or Virgo detectors. We introduce the method of a linear search grid to analyze GRB events with large sky localization uncertainties, for example the localizations provided by the Fermi Gamma-ray Burst Monitor (GBM). Coherent searches for gravitational waves (GWs) can be computationally intensive when the GRB sky position is not well localized, due to the corrections required for the difference in arrival time between detectors. Using a linear search grid we are able to reduce the computational cost of the analysis by a factor of Oð10Þfor GBM events. Furthermore, we demonstrate that our analysis pipeline can improve upon the sky localization of GRBs detected by the GBM, if a high-frequency GW signal is observed in coincidence. We use the method of the linear grid in a search for GWs associated with 129 GRBs observed satellite-based gamma-ray experiments between 2006 and 2011. The GRBs in our sample had not been previously analyzed for GW counterparts. A fraction of our GRB events are analyzed using data from GEO 600 while the detector was using squeezed-light states to improve its sensitivity; this is the first search for GWs using data from a squeezed-light interferometric observatory. We find no evidence for GW signals, either with any individual GRB in this sample or with the population as a whole. For each GRB we place lower bounds on the distance to the progenitor, under an assumption of a fixed GWemission energy of 10−2M⊙c2, with a median exclusion distance of 0.8 Mpc for emission at 500 Hz and 0.3 Mpc at 1 kHz. The reduced computational cost associated with a linear search grid will enable rapid searches for GWs associated with Fermi GBM events once the advanced LIGO and Virgo detectors begin operation.http://journals.aps.org/prd/abstract/10.1103/PhysRevD.89.122004publishedVersionFil: Aasi, J. LIGO. California Institute of Technology; Estados Unidos de América.Fil: Domínguez, E. Argentinian Gravitational Wave Group; Argentina.Fil: Maglione, C. Argentinian Gravitational Wave Group; Argentina.Fil: Reula, O. Argentinian Gravitational Wave Group; Argentina.Fil: Ortega, W. Argentinian Gravitational Wave Group; Argentina.Fil: Wolovick, N. Argentinian Gravitational Wave Group; Argentina.Fil: Schilman, M. Argentinian Gravitational Wave Group; Argentina.Física de Partículas y Campo

    Searches for continuous gravitational waves from nine young supernova remnants

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    We describe directed searches for continuous gravitational waves in data from the sixth LIGO science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target's parameters are uncertain enough to warrant two searches, for a total of ten. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3-25.3 days using the matched-filtering F-statistic. We found no credible gravitational-wave signals. We set 95% confidence upper limits as strong (low) as 4×10254\times10^{-25} on intrinsic strain, 2×1072\times10^{-7} on fiducial ellipticity, and 4×1054\times10^{-5} on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes.Comment: Science summary available at http://www.ligo.org/science/Publication-S6DirectedSNR/index.ph

    Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

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    Paper producido por "The LIGO Scientific Collaboration and the Virgo Collaboration". (En el registro se mencionan solo algunos autores de las decenas de personas que participan).Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of ΩGWðfÞ ¼ Ωαðf=frefÞα, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5–1726 Hz. In the frequency band of 41.5–169.25 Hz for a spectral index of α¼ 0, we constrain the energy density of the stochastic background to be ΩGWðfÞ <5.6 × 10−6. For the 600–1000 Hz band, ΩGWðfÞ <0.14ðf=900 HzÞ3, a factor of 2.5 lower than the best previously reported upper limits. We find ΩGWðfÞ <1.8 × 10−4 using a spectral index of zero for 170–600 Hz and ΩGWðfÞ < 1.0ðf=1300 HzÞ3 for 1000–1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.231101publishedVersionFil: Aasi, J. LIGO. California Institute of Technology; Estados Unidos de América.Fil: Maglione, C. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Maglione, C. Argentinian Gravitational Wave Group; Argentina.Fil: Quiroga, G. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Quiroga, G. Argentinian Gravitational Wave Group; Argentina.Física de Partículas y Campo

    First all-sky search for continuous gravitational waves from unknown sources in binary systems

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    We present the first results of an all-sky search for continuous gravitational waves from unknown spinning neutron stars in binary systems using LIGO and Virgo data. Using a specially developed analysis program, the TwoSpect algorithm, the search was carried out on data from the sixth LIGO Science Run and the second and third Virgo Science Runs. The search covers a range of frequencies from 20 Hz to 520 Hz, a range of orbital periods from 2 to ~2,254 h and a frequency- and period-dependent range of frequency modulation depths from 0.277 to 100 mHz. This corresponds to a range of projected semi-major axes of the orbit from ~0.6e-3 ls to ~6,500 ls assuming the orbit of the binary is circular. While no plausible candidate gravitational wave events survive the pipeline, upper limits are set on the analyzed data. The most sensitive 95% confidence upper limit obtained on gravitational wave strain is 2.3e-24 at 217 Hz, assuming the source waves are circularly polarized. Although this search has been optimized for circular binary orbits, the upper limits obtained remain valid for orbital eccentricities as large as 0.9. In addition, upper limits are placed on continuous gravitational wave emission from the low-mass x-ray binary Scorpius X-1 between 20 Hz and 57.25 Hz.Comment: 16 pages, 6 figure

    Multimessenger Search for Sources of Gravitational Waves and High-Energy Neutrinos: Results for Initial LIGO-Virgo and IceCube

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    We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010 run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of gravitational-wave emission energy of 10210^{-2}\,M_\odotc2^2 at 150\sim 150\,Hz with 60\sim 60\,ms duration, and high-energy neutrino emission of 105110^{51}\,erg comparable to the isotropic gamma-ray energy of gamma-ray bursts, we limit the source rate below 1.6×1021.6 \times 10^{-2}\,Mpc3^{-3}yr1^{-1}. We also examine how combining information from gravitational waves and neutrinos will aid discovery in the advanced gravitational-wave detector era

    A directed search for gravitational waves from Scorpius X-1 with initial LIGO

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    19 pages, 8 figuresInternational audienceWe present results of a search for continuously-emitted gravitational radiation, directed at the brightest low-mass X-ray binary, Scorpius X-1. Our semi-coherent analysis covers 10 days of LIGO S5 data ranging from 50-550 Hz, and performs an incoherent sum of coherent F\mathcal{F}-statistic power distributed amongst frequency-modulated orbital sidebands. All candidates not removed at the veto stage were found to be consistent with noise at a 1% false alarm rate. We present Bayesian 95% confidence upper limits on gravitational-wave strain amplitude using two different prior distributions: a standard one, with no a priori assumptions about the orientation of Scorpius X-1; and an angle-restricted one, using a prior derived from electromagnetic observations. Median strain upper limits of 1.3e-24 and 8e-25 are reported at 150 Hz for the standard and angle-restricted searches respectively. This proof of principle analysis was limited to a short observation time by unknown effects of accretion on the intrinsic spin frequency of the neutron star, but improves upon previous upper limits by factors of ~1.4 for the standard, and 2.3 for the angle-restricted search at the sensitive region of the detector

    Proceedings of the Virtual 3rd UK Implementation Science Research Conference : Virtual conference. 16 and 17 July 2020.

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