1,393 research outputs found

    CV19022

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    This report provides the main results of the 2019 underwater television survey on the ‘Labadie, Jones and Cockburn Banks’ ICES assessment area; Functional Unit 20-21. The 2019 survey was multi-disciplinary in nature collecting UWTV, and other ecosystem data. A total of 95 UWTV stations were completed at 6 nm intervals over a randomised isometric grid design. The mean burrow density was 0.06 burrows/m2 compared with 0.27 burrows/m2 in 2018. The 2019 geostatistical abundance estimate was 617 million, a 77% decrease on the abundance for 2018, with a CV of 5% which is well below the upper limit of 20% recommended by SGNEPS 2012. Low densities were observed throughout the ground. Using the 2019 estimate of abundance and updated stock data implies catch in 2020 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 1131 and 1150 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2016–2018). One species of sea-pen (Virgularia mirabilis) were recorded as present at the stations surveyed. Trawl marks were observed at 32% of the stations surveyed

    Odd-parity perturbations of self-similar Vaidya spacetime

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    We carry out an analytic study of odd-parity perturbations of the self-similar Vaidya space-times that admit a naked singularity. It is found that an initially finite perturbation remains finite at the Cauchy horizon. This holds not only for the gauge invariant metric and matter perturbation, but also for all the gauge invariant perturbed Weyl curvature scalars, including the gravitational radiation scalars. In each case, `finiteness' refers to Sobolev norms of scalar quantities on naturally occurring spacelike hypersurfaces, as well as pointwise values of these quantities.Comment: 28 page

    Human and murine IFIT1 proteins do not restrict infection of negative-sense RNA viruses of the Orthomyxoviridae, Bunyaviridae, and Filoviridae families

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    UNLABELLED: Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) is a host protein with reported cell-intrinsic antiviral activity against several RNA viruses. The proposed basis for the activity against negative-sense RNA viruses is the binding to exposed 5\u27-triphosphates (5\u27-ppp) on the genome of viral RNA. However, recent studies reported relatively low binding affinities of IFIT1 for 5\u27-ppp RNA, suggesting that IFIT1 may not interact efficiently with this moiety under physiological conditions. To evaluate the ability of IFIT1 to have an impact on negative-sense RNA viruses, we infected Ifit1(-/-) and wild-type control mice and primary cells with four negative-sense RNA viruses (influenza A virus [IAV], La Crosse virus [LACV], Oropouche virus [OROV], and Ebola virus) corresponding to three distinct families. Unexpectedly, a lack of Ifit1 gene expression did not result in increased infection by any of these viruses in cell culture. Analogously, morbidity, mortality, and viral burdens in tissues were identical between Ifit1(-/-) and control mice after infection with IAV, LACV, or OROV. Finally, deletion of the human IFIT1 protein in A549 cells did not affect IAV replication or infection, and reciprocally, ectopic expression of IFIT1 in HEK293T cells did not inhibit IAV infection. To explain the lack of antiviral activity against IAV, we measured the binding affinity of IFIT1 for RNA oligonucleotides resembling the 5\u27 ends of IAV gene segments. The affinity for 5\u27-ppp RNA was approximately 10-fold lower than that for non-2\u27-O-methylated (cap 0) RNA oligonucleotides. Based on this analysis, we conclude that IFIT1 is not a dominant restriction factor against negative-sense RNA viruses. IMPORTANCE: Negative-sense RNA viruses, including influenza virus and Ebola virus, have been responsible for some of the most deadly outbreaks in recent history. The host interferon response and induction of antiviral genes contribute to the control of infections by these viruses. IFIT1 is highly induced after virus infection and reportedly has antiviral activity against several RNA and DNA viruses. However, its role in restricting infection by negative-sense RNA viruses remains unclear. In this study, we evaluated the ability of IFIT1 to inhibit negative-sense RNA virus replication and pathogenesis both in vitro and in vivo. Detailed cell culture and animal studies demonstrated that IFIT1 is not a dominant restriction factor against three different families of negative-sense RNA viruses

    CV20016

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    This report provides the main results and findings of the nineteenth annual underwater television survey on the Aran, Galway Bay and Slyne head Nephrops grounds, ICES assessment area; Functional Unit 17. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. In 2020 a total of 44 UWTV stations were successfully completed, 34 on the Aran Grounds, 5 on Galway Bay and 5 on Slyne Head patches. The mean burrow density observed in 2020, adjusted for edge effect, was medium at 0.29 burrows/m². The final krigged burrow abundance estimate for the Aran Grounds was 359 million burrows with a CV (Coefficient of Variance; relative standard error) of 4%. The final abundance estimate for Galway Bay was 27 million and for Slyne Head was 7 million, with CVs of 13% and 4% respectively. The total abundance estimates have fluctuated considerably over the time series. The 2020 combined abundance estimate (394 million burrows) is 20% lower than in 2019, and it is below the MSY Btrigger reference point (540 million burrows). Using the 2020 estimate of abundance and updated stock data implies catches between 443 and 508 tonnes in 2021 that correspond to the F ranges in the EU multi annual plan for Western Waters, assuming that discard rates and fishery selection patterns do not change from the average of 2017–2019. Virgularia mirabilis was the only sea-pen species observed on the UWTV footage. Trawl marks were present at 7% of the Aran stations surveyed

    Acute Sensitivity of Landslide Rates to Initial Soil Porosity

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    Some landslides move imperceptibly downslope, whereas others accelerate catastrophically. Experimental landslides triggered by rising pore water pressure moved at sharply contrasting rates due to small differences in initial porosity. Wet sandy soil with porosity of about 0.5 contracted during slope failure, partially liquefied, and accelerated within 1 second to speeds over 1 meter per second. The same soil with porosity of about 0.4 dilated during failure and slipped episodically at rates averaging 0.002 meter per second. Repeated slip episodes were induced by gradually rising pore water pressure and were arrested by pore dilation and attendant pore pressure decline

    CV20019

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    This report provides the main results of the eleventh underwater television survey of the various Nephrops patches in Functional Unit 19. The survey was multi-disciplinary in nature collecting UWTV, multi-beam and other ecosystem data. In 2020 a total 42 UWTV stations were successfully completed. The mean density estimates varied considerably across the different patches. The 2020 raised abundance estimate was a 20% decrease from the 2019 estimate and at 320 million burrows is below the MSY Btrigger reference point (430 million). Using the 2020 estimate of abundance and updated stock data implies catch in 2021 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 531 and 595 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2017–2019). Two species of sea pen were observed; Virgularia mirabilis and Pennatula phosphorea which have been observed on previous surveys of FU19. Trawl marks were observed at 26% of the stations surveyed

    Even perturbations of self-similar Vaidya space-time

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    We study even parity metric and matter perturbations of all angular modes in self-similar Vaidya space-time. We focus on the case where the background contains a naked singularity. Initial conditions are imposed describing a finite perturbation emerging from the portion of flat space-time preceding the matter-filled region of space-time. The most general perturbation satisfying the initial conditions is allowed impinge upon the Cauchy horizon (CH), whereat the perturbation remains finite: there is no ``blue-sheet'' instability. However when the perturbation evolves through the CH and onto the second future similarity horizon of the naked singularity, divergence necessarily occurs: this surface is found to be unstable. The analysis is based on the study of individual modes following a Mellin transform of the perturbation. We present an argument that the full perturbation remains finite after resummation of the (possibly infinite number of) modes.Comment: Accepted for publication in Physical Review D, 27 page
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