1,015 research outputs found

    The effect of amino acid deprivation on the transfer of iron through Caco-2 cell monolayers

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    Funding Source Rural and Environmental Scientific and Analytical Services, the Scottish Government Acknowledgments We thank Dr Helen Hayes for her technical support during this project. We also thank Dr Christine Kennedy for her involvement at the beginning of this project. This study was funded by Rural and Environmental Scientific and Advisory Service of Scottish Government.Peer reviewedPostprin

    Double-Peaked Narrow-Line Active Galactic Nuclei. II. The Case Of Equal Peaks

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    Active galactic nuclei (AGNs) with double-peaked narrow lines (DPAGNs) may be caused by kiloparsec-scale binary AGNs, bipolar outflows, or rotating gaseous disks. We examine the class of DPAGNs in which the two narrow-line components have closely similar intensity as being especially likely to involve disks or jets. Two spectroscopic indicators support this likelihood. For DPAGNs from Smith et al., the "equal-peaked" objects (EPAGNs) have [Ne V]/[O III] ratios lower than for a control sample of non-double-peaked AGNs. This is unexpected for a pair of normal AGNs in a galactic merger, but may be consistent with [O III] emission from a rotating ring with relatively little gas at small radii. Also, [O III]/H beta ratios of the redshifted and blueshifted systems in the EPAGN are more similar to each other than in a control sample, suggestive of a single ionizing source and inconsistent with the binary interpretation.University Cooperative Society of the University of Texas at AustinJane and Roland Blumberg Cenntenial Professorship in AstronomyAlfred P. Sloan FoundationNational Aeronautics and Space AdministrationNational Science FoundationU.S. Department of EnergyJapanese MonbukagakushoMax Planck SocietyUniversity of ChicagoInstitute for Advanced StudyJapan Participation GroupJohns Hopkins UniversityKorean Scientist GroupLos Alamos National LaboratoryMax-Planck-Institute for Astronomy (MPIA)Max-Planck-Institute for Astrophysics (MPA)New Mexico State UniversityUniversity of PittsburghUniversity of PortsmouthPrinceton UniversityUnited States Naval ObservatoryUniversity of WashingtonFermilabAstronom

    Personal nitrogen footprint tool for the United Kingdom

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    The global nitrogen (N) cycle has been transformed by human use of reactive N as a consequence of increased demand for food and energy. Given the considerable impact of humans on the N cycle, it is essential that we raise awareness amongst the public and policy makers as this is the first step in providing individuals and governments the opportunity to reduce their impact on the N cycle and reduce the environmental and health consequences of N pollution. Here we describe an N footprint tool for the UK developed as part of the N-PRINT program. The current per capita N footprint in the UK is 27.1 kg N per capita per year with food production constituting the largest proportion of the footprint (18.0 kg N per capita per year). Calculating an N footprint for 1971 (26.0 kg N per capita per year) demonstrates that per capita N footprints have increased slightly. The average UK footprint is smaller than that found in the USA but is higher than the Netherlands and Germany. Scenario analysis demonstrates that reducing food protein consumption to the levels recommended by the FAO and World Health Organization reduces the overall N footprint by 33%. Consuming a vegetarian diet and consuming only sustainable food both decreased the N footprint by 15% but changes in energy use have a much smaller impact

    Evidence that the AGN dominates the radio emission in z ~ 1 radio-quiet quasars

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    This document is the Accepted Manuscript version of the following article: Sarah V. White, Matt J. Jarvis, Eleni Kalfoutnzou, Martin J. Hardcastle, Aprajita Verma, Mose M. Cao Orjales, and Jason Stevens, 'Evidence that the AGN dominates the radio emission in z ~ 1 radio quiet quasars', Monthly Notices of the Royal Astronomical Society, first published online 3 February 2017, DOI: https://doi.org/10.1093/mnras/stx284 Key results are presented in Table 4 and Figure 7, which illustrates where the RQQs lie in relation to the far-infrared--radio correlation © 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.In order to understand the role of radio-quiet quasars (RQQs) in galaxy evolution, we must determine the relative levels of accretion and star-formation activity within these objects. Previous work at low radio flux-densities has shown that accretion makes a significant contribution to the total radio emission, in contrast with other quasar studies that suggest star formation dominates. To investigate, we use 70 RQQs from the Spitzer-Herschel Active Galaxy Survey. These quasars are all at zz ~ 1, thereby minimising evolutionary effects, and have been selected to span a factor of ~100 in optical luminosity, so that the luminosity dependence of their properties can be studied. We have imaged the sample using the Karl G. Jansky Very Large Array (JVLA), whose high sensitivity results in 35 RQQs being detected above 2 σ\sigma. This radio dataset is combined with far-infrared luminosities derived from grey-body fitting to Herschel photometry. By exploiting the far-infrared--radio correlation observed for star-forming galaxies, and comparing two independent estimates of the star-formation rate, we show that star formation alone is not sufficient to explain the total radio emission. Considering RQQs above a 2-σ\sigma detection level in both the radio and the far-infrared, 92 per cent are accretion-dominated, and the accretion process accounts for 80 per cent of the radio luminosity when summed across the objects. The radio emission connected with accretion appears to be correlated with the optical luminosity of the RQQ, whilst a weaker luminosity-dependence is evident for the radio emission connected with star formation.Peer reviewedFinal Accepted Versio

    Losartan Treatment Attenuates Tumor-induced Myocardial Dysfunction

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    Fatigue and muscle wasting are common symptoms experienced by cancer patients. Data from animal models demonstrate that angiotensin is involved in tumor-induced muscle wasting, and that tumor growth can independently affect myocardial function, which could contribute to fatigue in cancer patients. In clinical studies, inhibitors of angiotensin converting enzyme (ACE) can prevent the development of chemotherapy-induced cardiovascular dysfunction, suggesting a mechanistic role for the renin–angiotensin–aldosterone system (RAAS). In the present study, we investigated whether an angiotensin (AT) 1-receptor antagonist could prevent the development of tumor-associated myocardial dysfunction. Methods and results: Colon26 adenocarcinoma (c26) cells were implanted into female CD2F1 mice at 8 weeks of age. Simultaneously, mice were administered Losartan (10 mg/kg) daily via their drinking water. In vivo echocardiography, blood pressure, in vitro cardiomyocyte function, cell proliferation assays, and measures of systemic inflammation and myocardial protein degradation were performed 19 days following tumor cell injection. Losartan treatment prevented tumor-induced loss of muscle mass and in vitro c26 cell proliferation, decreased tumor weight, and attenuated myocardial expression of interleukin-6. Furthermore, Losartan treatment mitigated tumor-associated alterations in calcium signaling in cardiomyocytes, which was associated with improved myocyte contraction velocity, systolic function, and blood pressures in the hearts of tumor-bearing mice. Conclusions: These data suggest that Losartan may mitigate tumor-induced myocardial dysfunction and inflammation

    Relationship between Greenland Ice Sheet surface speed and modeled effective pressure

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    Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Earth Surface 123 (2018): 2258-2278, doi:10.1029/2017JF004581.We use a numerical subglacial hydrology model and remotely sensed observations of Greenland Ice Sheet surface motion to test whether the inverse relationship between effective pressure and regional melt season surface speeds observed at individual sites holds on a regional scale. The model is forced with daily surface runoff estimates for 2009 and 2010 across an ~8,000‐km2 region on the western margin. The overall subglacial drainage system morphology develops similarly in both years, with subglacial channel networks growing inland from the ice sheet margin and robust subglacial pathways forming over bedrock ridges. Modeled effective pressures are compared to contemporaneous regional surface speeds derived from TerraSAR‐X imagery to investigate spatial relationships. Our results show an inverse spatial relationship between effective pressure and ice speed in the mid‐melt season, when surface speeds are elevated, indicating that effective pressure is the dominant control on surface velocities in the mid‐melt season. By contrast, in the early and late melt seasons, when surface speeds are slower, effective pressure and surface speed have a positive relationship. Our results suggest that outside of the mid‐melt season, the influence of effective pressures on sliding speeds may be secondary to the influence of driving stress and spatially variable bed roughness.National Aeronautics and Space Administration (NASA). Grant Number: NXX10AI30G National Science Foundation (NSF) American Geophysical Union Horton Research Grant; National Science Foundation Graduate Research Fellowship; National Science Foundation's Office of Polar Programs (NSF‐OPP) Grant Numbers: PLR‐1418256, ARC‐1023364, ARC‐0520077; Woods Hole Oceanographic Institution's Ocean and Climate Change Institute (OCCI)2019-03-2

    Impure placebo as an unsound concept and other problems in the paper by Howick et al. : [eLetter]

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    Kommentti artikkeliin Placebo Use in the United Kingdom: Results from a National Survey of Primary Care Practitioners, Plos One 8(3):e58247. doi: 10.1371/journal.pone.0058247Howick et al. have reported the findings of a survey that addressed the use of placebos among primary care practitioners in the United Kingdom. They adopted methodology similar to that used in previous studies performed in other countries; however, the use of this approach also means that they repeated the conceptual confusion of the previous surveys. Therefore the findings are not useful. ... The paper’s main finding “placebos are commonly used in UK primary care” is not correct. Only 0.9% of the responding general practitioners reported using pure placebos frequently. The frequency with which impure placebos are used is irrelevant because the concept is useless, as described above. Misleading a patient by administering inert substances without the explicit consent of the patient is unethical. The authors' proposal to “develop ethical and cost-effective placebos” is not possible because saving money by misleading patients is unethical. There is substantial conceptual confusion in the area of placebo and placebo-effect research, and the paper by Howick et al. does not help to reduce this confusion.Non peer reviewe

    Linking glacially modified waters to catchment-scale subglacial discharge using autonomous underwater vehicle observations

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    © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cryosphere 10 (2016): 417-432, doi:10.5194/tc-10-417-2016.Measurements of near-ice (<  200 m) hydrography and near-terminus subglacial hydrology are lacking, due in large part to the difficulty in working at the margin of calving glaciers. Here we pair detailed hydrographic and bathymetric measurements collected with an autonomous underwater vehicle as close as 150 m from the ice–ocean interface of the Saqqarliup sermia–Sarqardleq Fjord system, West Greenland, with modeled and observed subglacial discharge locations and magnitudes. We find evidence of two main types of subsurface glacially modified water (GMW) with distinct properties and locations. The two GMW locations also align with modeled runoff discharged at separate locations along the grounded margin corresponding with two prominent subcatchments beneath Saqqarliup sermia. Thus, near-ice observations and subglacial discharge routing indicate that runoff from this glacier occurs primarily at two discrete locations and gives rise to two distinct glacially modified waters. Furthermore, we show that the location with the largest subglacial discharge is associated with the lighter, fresher glacially modified water mass. This is qualitatively consistent with results from an idealized plume model.Support was provided by the National Science Foundation’s Office of Polar Programs (NSF-OPP) through PLR-1418256 to F. Straneo, S. B. Das and A. J. Plueddemann, PLR-1023364 to S. B. Das, and through the Woods Hole Oceanographic Institution Ocean and Climate Change Institute Arctic Research Initiative to F. Straneo, S. B. Das, and A. J. Plueddemann. L. A. Stevens was also supported by a National Science Foundation Graduate Research Fellowship. S. B. Das was also supported by the Woods Hole Oceanographic Institution James E. and Barbara V. Moltz Research Fellowship. M. Morlighem was supported by the National Aeronautics and Space Administration’s (NASA) Cryospheric Sciences Program through NNX15AD55G
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