509 research outputs found

    Linearisation Instabilities of the Massive Nonsymmetric Gravitational Theory

    Get PDF
    The massive nonsymmetric gravitational theory is shown to posses a linearisation instability at purely GR field configurations, disallowing the use of the linear approximation in these situations. It is also shown that arbitrarily small antisymmetric sector Cauchy data leads to singular evolution unless an ad hoc condition is imposed on the initial data hypersurface.Comment: 14 pages, IOP style for submission to CQG. Minor changes and additional background material adde

    Summary Report on 2018 Residue Monitoring of Irish Farmed Finfish & 2018 Border Inspection Post Fishery Product Testing undertaken at the Marine Institute

    Get PDF
    On behalf of the Department of Agriculture, Food and Marine (DAFM), the Marine Institute carries out monitoring of chemical residues in finfish for aquaculture sector. This monitoring is set out in the annual National Residue Control Plan, which is approved by the European Commission, and is an important component of the DAFM food safety controls and is implemented under a service contract with the Food Safety Authority of Ireland. Since 1999, the Marine Institute has implemented the National Residues Monitoring Programme for aquaculture. This is carried out on behalf of the Sea Fisheries Protection Authority, which is the responsible organisation for residue controls on farmed finfish. In 2018, in excess of 920 tests and a total of 2,611 measurements were carried out on 171 samples of farmed finfish for a range of residues. Implementation of the Aquaculture 2018 Plan involves taking samples at both farm and processing plant: • 123 target samples taken at harvest: 110 farmed salmon and 13 freshwater trout. • 48 target samples were taken at other stages of production: 40 salmon smolts and 8 freshwater trout. All 2018 samples were compliant. For target sampling of farmed fish, a summary table of the residue results from 2005 - 2018 is outlined in Table 1. Overall, the outcome for aquaculture remains one of consistently low occurrence of residues in farmed finfish, with no non-compliant target residues results for the period 2006-2014, 0.11% and 0.10% non-compliant target residues results in 2015 and 2016 respectively and no non-compliant target results in 2017 and 2018

    The effect of lutein intake on macular pigment density

    Get PDF
    Age related macular degeneration (AMD) is a sight-threatening retinal disease found predominately in men and women over 65 years of age. AMD is thought to result from oxidative damage to the retina triggered by UV and blue light. Recent studies have suggested the onset and progression of AMD may be delayed by diet supplementation with antioxidants like lutein and zeaxanthin which are found in the macular area as the macular pigments. The density of the macular pigments can be quantified using heterochromic flicker photometry. In this study, 29 optometry students, between the ages of 22 and 30, were divided into groups. Group one, the control group, experienced no intervention, group two took 4 mg of lutein daily for 30 days and group three ingested 0.75 ounces of spinach daily for 30 days. The macular pigment density was assessed at baseline before any intervention, after 30 days of supplementation and again 30 days after discontinuing supplementation. Neither lutein nor spinach increased the macular pigment density in this study

    Reel-to-reel atmospheric pressure dielectric barrier discharge (DBD) plasma treatment of polypropylene films

    Get PDF
    © 2017 by the authors. Atmospheric pressure plasma treatment of the surface of a polypropylene film can significantly increase its surface energy and, thereby improve the printability of the film. A laboratory-scale dielectric barrier discharge (DBD) system has therefore been developed, which simulates the electrode configuration and reel-to-reel web transport mechanism used in a typical industrial-scale system. By treating the polypropylene in a nitrogen discharge, we have shown that the water contact angle could be reduced by as much as 40° compared to the untreated film, corresponding to an increase in surface energy of 14 mNm-1. Ink pull-off tests showed that the DBD plasma treatment resulted in excellent adhesion of solvent-based inks to the polypropylene film

    Summary Report on 2019 Residue Monitoring of Irish Farmed Fish & 2019 Border Inspection Post Fishery Product Testing undertaken at the Marine Institute

    Get PDF
    On behalf of the Department of Agriculture, Food and Marine (DAFM), the Marine Institute carries out monitoring of chemical residues in finfish for aquaculture sector. This monitoring is set out in the annual National Residue Control Plan, which is approved by the European Commission, and is an important component of the DAFM food safety controls and is implemented under a service contract with the Food Safety Authority of Ireland. Since 1999, the Marine Institute has implemented the National Residues Monitoring Programme for aquaculture. This is carried out on behalf of the Sea Fisheries Protection Authority, which is the responsible organisation for residue controls on farmed finfish. In 2019, in excess of 912 tests and a total of 2,601 measurements were carried out on 176 samples of farmed finfish for a range of residues. Implementation of the Aquaculture 2019 Plan involves taking samples at both farm and processing plant: *118 target samples taken at harvest: 105 farmed salmon and 13 freshwater trout. * 58 target samples were taken at other stages of production: 50 salmon smolts and 8 freshwater trout. All 2019 samples were compliant. For target sampling of farmed fish, a summary table of the residue results from 2005 - 2019 is outlined in Table 1. Overall, the outcome for aquaculture remains one of consistently low occurrence of residues in farmed finfish, with no non-compliant target residues results for the period 2006-2014, 0.11% and 0.10% non-compliant target residues results in 2015 and 2016 respectively and no non-compliant target results for the period 2017 to 2019

    CHEMREP 2022-028

    Get PDF
    On behalf of the Department of Agriculture, Food and Marine (DAFM), the Marine Institute carries out monitoring of chemical residues in finfish for aquaculture sector. This monitoring is set out in the annual National Residue Control Plan, which is approved by the European Commission, and is an important component of the DAFM food safety controls and is implemented under a service contract with the Food Safety Authority of Ireland. Since 1999, the Marine Institute has implemented the National Residues Monitoring Programme for aquaculture. This is carried out on behalf of the Sea Fisheries Protection Authority, which is the responsible organisation for residue controls on farmed finfish. In 2021, in excess of 632 tests and a total of 1,870 measurements were carried out on 120 samples of farmed finfish for a range of residues. Implementation of the Aquaculture 2021 Plan involves taking samples at both farm and processing plant: *80 target samples taken at harvest: 70 farmed salmon and 10 freshwater trout. *40 target samples were taken at other stages of production: 30 salmon smolts and 10 freshwater trout. All 2021 samples were compliant. For target sampling of farmed fish, a summary table of the residue results from 2005 - 2021 is outlined in Table 1. Overall, the outcome for aquaculture remains one of consistently low occurrence of residues in farmed finfish, with no non-compliant target residues results for the period 2006-2014, 0.11% and 0.10% non-compliant target residues results in 2015 and 2016 respectively and no non-compliant target results for the period 2017 to 2021

    The Wolf-Rayet population of the nearby barred spiral galaxy NGC 5068 uncovered by the Very Large Telescope and Gemini

    Get PDF
    We present a narrow-band Very Large Telescope/Focal Reduced Low-dispersion Spectrograph #1 imaging survey of the SAB(rs)cd spiral galaxy NGC 5068, located at a distance of 5.45 Mpc, from which 160 candidate Wolf–Rayet sources have been identified, of which 59 cases possess statistically significant λ4686 excesses. Follow-up Gemini Multi-Object Spectrograph spectroscopy of 64 candidates, representing 40 per cent of the complete photometric catalogue, confirms Wolf–Rayet signatures in 30 instances, corresponding to a 47 per cent success rate. 21 out of 22 statistically significant photometric sources are spectroscopically confirmed. Nebular emission detected in 30 per cent of the Wolf–Rayet candidates spectrally observed, which enable a re-assessment of the metallicity gradient in NGC 5068. A central metallicity of log (O/H) + 12 ∼ 8.74 is obtained, declining to 8.23 at R25. We combine our spectroscopy with archival Hα images of NGC 5068 to estimate a current star formation rate of Graphic, and provide a catalogue of the 28 brightest H ii regions from our own continuum subtracted Hα images, of which ∼17 qualify as giant H ii regions. Spectroscopically, we identify 24 WC- and 18 WN-type Wolf–Rayet stars within 30 sources since emission-line fluxes indicate multiple Wolf–Rayet stars in several cases. We estimate an additional ∼66 Wolf–Rayet stars from the remaining photometric candidates, although sensitivity limits will lead to an incomplete census of visually faint WN stars, from which we estimate a global population of ∼170 Wolf–Rayet stars. Based on the Hα-derived O star population of NGC 5068 and N(WR)/N(O) ∼ 0.03, representative of the Large Magellanic Cloud, we would expect a larger Wolf–Rayet population of 270 stars. Finally, we have compared the spatial distribution of spectroscopically confirmed WN and WC stars with Sloan Digital Sky Survey derived supernovae, and find both WN and WC stars to be most consistent with the parent population of Type Ib supernovae

    Chemical Residue in Irish Farmed Finfish, 2011

    Get PDF
    The following organisations and people within them, made valuable contributions in assisting with the delivery of 2011 residue monitoring programme for farmed finfish: Department of Agriculture, Food & Marine; Food Safety Authority of Ireland; Sea-Fisheries Protection Authority; The ongoing co-operation of the aquaculture industry.On behalf of the Department of Agriculture, Food and Marine (DAFM), the Marine Institute carries out monitoring of chemical residues in aquaculture in accordance with Council Directive 96/23/EC of 29 April 1996, on measures to monitor certain substances and residues thereof in animals and animal products. The main objectives of the Aquaculture National Residue Control Plan (NRCP) is to ensure farmed fish are fit for human consumption, to provide a body of data showing that Irish farmed fish is of high quality, to promote good practices in aquaculture and to comply with EU Directive 96/23. In 2011, in excess of 630 tests and 1,566 individual measurements for substances were carried out on 140 samples of farmed finfish taken on farms and at processing plants for a range of residues. In accordance with Council Directive 96/23/EC, the following species were sampled and tested: Atlantic salmon (Salmo salar), freshwater and seareared trout (Oncorhynchus mykiss). Tests were carried out for banned substances such as growth promoters, and other unauthorised substances such as malachite green, which should not be present. Harvested fish were also tested for authorised veterinary treatments such as antibiotics and sea lice treatments, environmental contaminants such as trace metals, polychlorinated biphenyls and organochlorine pesticides, to check for compliance with Maximum Residue Levels (MRL) where available. As in previous years, no non-compliant results were reported in the surveillance monitoring programme for farmed finfish. Overall, in recent years the outcome for aquaculture remains one of consistently low occurrence of residues in farmed finfish, with 0.23% non-compliant results from routine targeted monitoring in 2004, 0.09% in 2005 and 0% for the period 2006-2011.Funder: Marine Institut

    A Very Large Telescope imaging and spectroscopic survey of the Wolf-Rayet population in NGC 7793

    Get PDF
    We present a VLT/FORS1 imaging and spectroscopic survey of the Wolf-Rayet (WR) population in the Sculptor group spiral galaxy NGC 7793. We identify 74 emission line candidates from archival narrow-band imaging, from which 39 were observed with the Multi Object Spectroscopy (MOS) mode of FORS1. 85% of these sources displayed WR features. Additional slits were used to observe HII regions, enabling an estimate of the metallicity gradient of NGC 7793 using strong line calibrations, from which a central oxygen content of log (O/H) + 12 = 8.6 was obtained, falling to 8.25 at R_25. We have estimated WR populations using a calibration of line luminosities of Large Magellanic Cloud stars, revealing ~27 WN and ~25 WC stars from 29 sources spectroscopically observed. Photometric properties of the remaining candidates suggest an additional ~27 WN and ~8 WC stars. A comparison with the WR census of the LMC suggests that our imaging survey has identified 80% of WN stars and 90% for the WC subclass. Allowing for incompleteness, NGC 7793 hosts ~105 WR stars for which N(WC)/N(WN)~0.5. From our spectroscopy of HII regions in NGC 7793, we revise the global Halpha star formation rate of Kennicutt et al. upward by 50% to 0.45 M_sun/yr. This allows us to obtain N(WR)/N(O)~0.018, which is somewhat lower than that resulting from the WR census by Schild et al. of another Sculptor group spiral NGC 300, whose global physical properties are similar to NGC 7793. Finally, we also report the fortuitous detection of a bright (m_V = 20.8 mag) background quasar Q2358-32 at z~2.02 resulting from CIV 1548-51 redshifted to the 4684 passband.Comment: 17 pages, 13 figures, accepted for MNRAS (detailed finding charts omitted)

    Runaway stars as progenitors of supernovae and gamma-ray bursts

    Full text link
    When a core collapse supernova occurs in a binary system, the surviving star as well as the compact remnant emerging from the SN, may reach a substantial space velocity. With binary population synthesis modelling at solar and one fifth of solar metallicity, we predict the velocities of such runaway stars or binaries. We compile predictions for runaway OB stars, red supergiants and Wolf-Rayet stars. For those stars or binaries which undergo a second stellar explosion we compute their further evolution and the distance travelled until a Type II or Type Ibc SN or a long or short gamma-ray burst occurs. We find our predicted population of OB runaway stars broadly matches the observed population of stars but, to match the fastest observed WR runaway stars, we require that black holes receive an asymmetric kick upon formation. We find that at solar metallicity Type Ic SN progenitors travel shorter distances than the progenitors of other SN types because they are typically more massive and thus have shorter lifetimes. Those of Type IIP SN can fly farthest about 48 pc on average at solar metallicity. In considering the consequences of assuming that the progenitors of long GRBs are spun-up secondary stars that experience quasi-homogeneous evolution, we find that such evolution has a dramatic effect on the population of runaway WR stars and that some 30 per cent of GRBs could occur a hundred parsecs or more from their initial positions. We also consider mergers of double compact object binaries consisting of neutron stars and/or black holes. We find the most common type of visible mergers are neutron star--black hole mergers that are roughly ten times more common than neutron star--neutron star mergers. We also find that there may be a population of low-velocity neutron stars that are ejected from a binary rather than by their own natal kick.Comment: Accepted for publication in MNRAS, 23 pages, 17 figures and 11 tables. Abstract was editted to fit within arXiv.org submission requirement
    • …
    corecore