41 research outputs found

    Gravitational Wave Emission From Core-Collapse of Massive Stars

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    We derive estimates for the characteristics of gravitational radiation from stellar collapse, using recent models of the core-collapse of Chandrasekhar mass white dwarfs (accretion induced collapse), core-collapse supernovae and collapsars, and the collapse of very massive stars (~> 300 Msun). We study gravitational-wave emission mechanisms using several estimation techniques, including two-dimensional numerical computation of quadrupole wave emission, estimates of bar-mode strength, estimates of r-mode emission, and estimates of waves from black hole ringing. We also review the rate at which the relevant collapses are believed to occur, which has a major impact on their relevance as astrophysical sources. Although the latest supernova progenitor simulations produce cores rotating much slower than those used in the past, we find that bar-mode and r-mode instabilities from core-collapse supernovae remain among the leading candidate sources for LIGO-II. Accretion induced collapse (AIC) of a white dwarf could produce gravitational-wave signals similar to those from core-collapse. In the models that we examine, such collapses are not unstable to bar modes; we note that models recently examined by Liu and Lindblom, which have slightly more angular momentum, are certainly unstable to bar formation. Because AIC events are probably 1,000 times less common than core-collapse supernovae, the typical AIC event will be much further away, and thus the observed waves will be much weaker. In the most optimistic circumstances, we find it may be possible to detect gravitational waves from the collapse of 300 Msun Population III stars.Comment: 48 pages including 11 figures, to appear in ApJ. New version incorporates several helpful comments; also corrects some errors in the displayed LIGO noise curve, and several typo

    Radiative falloff in Schwarzschild-de Sitter spacetime

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    We consider the time evolution of a scalar field propagating in Schwarzschild-de Sitter spacetime. At early times, the field behaves as if it were in pure Schwarzschild spacetime; the structure of spacetime far from the black hole has no influence on the evolution. In this early epoch, the field's initial outburst is followed by quasi-normal oscillations, and then by an inverse power-law decay. At intermediate times, the power-law behavior gives way to a faster, exponential decay. At late times, the field behaves as if it were in pure de Sitter spacetime; the structure of spacetime near the black hole no longer influences the evolution in a significant way. In this late epoch, the field's behavior depends on the value of the curvature-coupling constant xi. If xi is less than a critical value 3/16, the field decays exponentially, with a decay constant that increases with increasing xi. If xi > 3/16, the field oscillates with a frequency that increases with increasing xi; the amplitude of the field still decays exponentially, but the decay constant is independent of xi.Comment: 10 pages, ReVTeX, 5 figures, references updated, and new section adde

    Pan-European rural monitoring network shows dominance of NH3 gas and NH4NO3 aerosol in inorganic atmospheric pollution load

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    A comprehensive European dataset on monthly atmospheric NH3, acid gases (HNO3, SO2, HCl), and aerosols (NH4+, NO3-, SO42-, Cl−, Na+, Ca2+, Mg2+) is presented and analysed. Speciated measurements were made with a low-volume denuder and filter pack method (DEnuder for Long-Term Atmospheric sampling, DELTA®) as part of the EU NitroEurope (NEU) integrated project. Altogether, there were 64 sites in 20 countries (2006–2010), coordinated between seven European laboratories. Bulk wet-deposition measurements were carried out at 16 co-located sites (2008–2010). Inter-comparisons of chemical analysis and DELTA® measurements allowed an assessment of comparability between laboratories. The form and concentrations of the different gas and aerosol components measured varied between individual sites and grouped sites according to country, European regions, and four main ecosystem types (crops, grassland, forests, and semi-natural). The smallest concentrations (with the exception of SO42- and Na+) were in northern Europe (Scandinavia), with broad elevations of all components across other regions. SO2 concentrations were highest in central and eastern Europe, with larger SO2 emissions, but particulate SO42- concentrations were more homogeneous between regions. Gas-phase NH3 was the most abundant single measured component at the majority of sites, with the largest variability in concentrations across the network. The largest concentrations of NH3, NH4+ and NO-3 were at cropland sites in intensively managed agricultural areas (e.g. Borgo Cioffi in Italy), and the smallest were at remote semi-natural and forest sites (e.g. Lompolojänkkä, Finland), highlighting the potential for NH3 to drive the formation of both NH4+ and NO3- aerosol. In the aerosol phase, NH4+ was highly correlated with both NO3- and SO42-, with a near-1:1 relationship between the equivalent concentrations of NH4+ and sum(NO3- + SO42-) of which around 60 % was as NH4NO3. Distinct seasonality was also observed in the data, influenced by changes in emissions, chemical interactions, and the influence of meteorology on partitioning between the main inorganic gases and aerosol species. Springtime maxima in NH3 were attributed to the main period of manure spreading, while the peak in summer and trough in winter were linked to the influence of temperature and rainfall on emissions, deposition, and gas–aerosol-phase equilibrium. Seasonality in SO2 was mainly driven by emissions (combustion), with concentrations peaking in winter, except in southern Europe, where the peak occurred in summer. Particulate SO42− showed large peaks in concentrations in summer in southern and eastern Europe, contrasting with much smaller peaks occurring in early spring in other regions. The peaks in particulate SO42- coincided with peaks in NH3 concentrations, attributed to the formation of the stable (NH4)2SO4. HNO3 concentrations were more complex, related to traffic and industrial emissions, photochemistry, and HNO3:NH4NO3 partitioning. While HNO3 concentrations were seen to peak in the summer in eastern and southern Europe (increased photochemistry), the absence of a spring peak in HNO3 in all regions may be explained by the depletion of HNO3 through reaction with surplus NH3 to form the semi-volatile aerosol NH4NO3. Cooler, wetter conditions in early spring favour the formation and persistence of NH4NO3 in the aerosol phase, consistent with the higher springtime concentrations of NH4+ and NO3−. The seasonal profile of NO3- was mirrored by NH4+, illustrating the influence of gas–aerosol partitioning of NH4NO3 in the seasonality of these components. Gas-phase NH3 and aerosol NH4NO3 were the dominant species in the total inorganic gas and aerosol species measured in the NEU network. With the current and projected trends in SO2, NOx , and NH3 emissions, concentrations of NH3 and NH4NO3 can be expected to continue to dominate the inorganic pollution load over the next decades, especially NH3, which is linked to substantial exceedances of ecological thresholds across Europe. The shift from (NH4)2SO4 to an atmosphere more abundant in NH4NO3 is expected to maintain a larger fraction of reactive N in the gas phase by partitioning to NH3 and HNO3 in warm weather, while NH4NO3 continues to contribute to exceedances of air quality limits for PM2.5

    Fatal COVID-19 outcomes are associated with an antibody response targeting epitopes shared with endemic coronaviruses

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    The role of immune responses to previously seen endemic coronavirus epitopes in severe acute respiratory coronavirus 2 (SARS-CoV-2) infection and disease progression has not yet been determined. Here, we show that a key characteristic of fatal coronavirus disease (COVID-19) outcomes is that the immune response to the SARS-CoV-2 spike protein is enriched for antibodies directed against epitopes shared with endemic beta-coronaviruses, and has a lower proportion of antibodies targeting the more protective variable regions of the spike. The magnitude of antibody responses to the SARS-CoV-2 full-length spike protein, its domains and subunits, and the SARS-CoV-2 nucleocapsid also correlated strongly with responses to the endemic beta-coronavirus spike proteins in individuals admitted to intensive care units (ICU) with fatal COVID-19 outcomes, but not in individuals with non-fatal outcomes. This correlation was found to be due to the antibody response directed at the S2 subunit of the SARS-CoV-2 spike protein, which has the highest degree of conservation between the beta-coronavirus spike proteins. Intriguingly, antibody responses to the less cross-reactive SARS-CoV-2 nucleocapsid were not significantly different in individuals who were admitted to ICU with fatal and non-fatal outcomes, suggesting an antibody profile in individuals with fatal outcomes consistent with an original antigenic sin type-response

    Crop Updates 2001 - Cereals

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    This session covers forty two papers from different authors: PLENARY 1. Planning your cropping program in season 2001, Dr Ross Kingwell, Agriculture Western Australia and University of Western Australia WORKSHOP 2. Can we produce high yields without high inputs? Wal Anderson, Centre for Cropping Systems, Agriculture Western Australia VARIETIES 3. Local and interstate wheat variety performance and $ return to WA growers, Eddy Pol, Peter Burgess and Ashley Bacon, Agritech Crop Research CROP ESTABLISHMENT 4 Soil management of waterlogged soils, D.M. Bakker, G.J. Hamilton, D. Houlbrooke and C. Spann, Agriculture Western Australia 5. Effect of soil amelioration on wheat yield in a very dry season, M.A Hamza and W.K. Anderson, Agriculture Western Australia 6. Fuzzy tramlines for more yield and less weed, Paul Blackwell1 and Maurice Black2 1Agriculture Western Australia, 2Harbour Lights Estate, Geraldton 7. Tramline farming for dollar benefits, Paul Blackwell, Agriculture Western Australia NUTRITION 8. Soil immobile nutrients for no-till crops, M.D.A. Bolland1, R.F. Brennan1,and W.L. Crabtree2, 1Agriculture Western Australia, 2Western Australian No-Tillage Farmers Association 9. Burn stubble windrows: to diagnose soil fertility problems, Bill Bowden, Chris Gazey and Ross Brennan, Agriculture Western Australia 10. Calcium: magnesium ratios; are they important? Bill Bowden1, Rochelle Strahan2, Bob Gilkes2 and Zed Rengel2 1Agriculture Western Australia, 2Department of Soil Science and Plant Nutrition, UWA 11. Responses to late foliar applications of Flexi-N, Stephen Loss, Tim O’Dea, Patrick Gethin, Ryan Guthrie, Lisa Leaver, CSBP futurefarm 12. A comparison of Flexi-N placements, Stephen Loss, Tim O’Dea, Patrick Gethin, Ryan Guthrie, Lisa Leaver, CSBP futurefarm 13. What is the best way to apply potassium? Stephen Loss, Tim O’Dea, Patrick Gethin, Ryan Guthrie, CSBP futurefarm 14. Claying affects potassium nutrition in barley, Stephen Loss, David Phelps, Tim O’Dea, Patrick Gethin, Ryan Guthrie, Lisa Leaver, CSBP futurefarm 15. Nitrogen and potassium improve oaten hay quality, Stephen Loss, Tim O’Dea, Patrick Gethin, Ryan Guthrie, Lisa Leaver, CSBP futurefarm AGRONOMY 16. Agronomic responses of new wheat varieties in the northern wheatbelt, Darshan Sharma and Wal Anderson, Agriculture Western Australia 17. Wheat agronomy research on the south coast, Mohammad Amjad and Wal Anderson, Agriculture Western Australia 18. Influence of sowing date on wheat yield and quality in the south coast environment, Mohammad Amjadand Wal Anderson, Agriculture Western Australia 19. More profit from durum, Md.Shahajahan Miyan and Wal Anderson, Agriculture Western Australia 20. Enhancing recommendations of flowering and yield in wheat, JamesFisher1, Senthold Asseng2, Bill Bowden1 and Michael Robertson3 ,1AgricultureWestern Australia, 2CSIRO Plant Industry, 3CSIRO Sustainable Ecosystems 21. When and where to grow oats, Glenn McDonald, Agriculture Western Australia 22. Managing Gaidner barley for quality, Kevin Young and Blakely Paynter, Agriculture Western Australia PESTS AND DISEASES 23. Strategies for leaf disease management in wheat, Jatinderpal Bhathal1, Cameron Weeks2, Kith Jayasena1 and Robert Loughman1 ,1Agriculture Western Australia. 2Mingenew-Irwin Group Inc 24. Strategies for leaf disease management in malting barley, K. Jayasena1, Q. Knight2 and R. Loughman1, 1Agriculture Western Australia, 2IAMA Agribusiness 25. Cereal disease diagnostics, Dominie Wright and Nichole Burges, Agriculture Western Australia 26. The big rust: Did you get your money back!! Peter Burgess, Agritech Crop Research 27. Jockey – winning the race against disease in wheat, Lisa-Jane Blacklow, Rob Hulme and Rob Giffith, Aventis CropScience 28. Distribution and incidence of aphids and barley yellow dwarf virus in over-summering grasses in WA wheatbelt, Jenny Hawkes and Roger Jones, CLIMA and Agriculture Western Australia 29. Further developments in forecasting aphid and virus risk in cereals, Debbie Thackray, Jenny Hawkes and Roger Jones, Agriculture Western Australia and Centre for Legumes in Mediterranean Agriculture 30. Effect of root lesion nematodes on wheat yields in Western Australia, S. B. Sharma, S. Kelly and R. Loughman, Crop Improvement Institute, Agriculture Western Australia 31. Rotational crops and varieties for management of root lesion nematodes in Western Australia, S.B. Sharma, S. Kelly and R. Loughman, Crop Improvement Institute, Agriculture Western Australia WEEDS 32. Phenoxy herbicide tolerance of wheat, Peter Newman and Dave Nicholson, Agriculture Western Australia 33. Tolerance of wheat to phenoxy herbicides,Harmohinder S. Dhammu, Terry Piper and Mario F. D\u27Antuono, Agriculture Western Australia 34. Herbicide tolerance of durum wheats, Harmohinder S. Dhammu, Terry Piper and David Nicholson, Agriculture Western Australia 35. Herbicide tolerance of new wheats, Harmohinder S. Dhammu, Terry Piper and David F. Nicholson, Agriculture Western Australia BREEDING 36. Towards molecular breeding of barley: construction of a molecular genetic map, Mehmet Cakir1, Nick Galwey1, David Poulsen2, Garry Ablett3, Reg Lance4, Rob Potter5 and Peter Langridge6,1Plant Sciences, Faculty of Agriculture, UWA, 2Queensland Department of Primary Industries, Qld, 3Centre for Plant Conservation Genetics Southern Cross University, Lismore NSW, 5SABC Murdoch University, WA, 6Department of Plant Science University of Adelaide, Glen Osmond SA 37. Toward molecular breeding of barley: Identifying markers linked to genes for quantitative traits, Mehmet Cakir1, Nick Galwey1, David Poulsen2, Reg Lance3, Garry Ablett4, Greg Platz2, Joe Panozzo5, Barbara Read6, David Moody5, Andy Barr7 and Peter Langridge7 , 1Plant Sciences, Faculty of Agriculture, UWA, 2Queensland Department of Primary Industries, Warwick, QLD,3Agriculture Western Australia, 4Centre for Plant Conservation Genetics, Southern Cross University, Lismore NSW, 5VIDA Private Bag 260, Horsham VIC, 6NSW Dept. of Agriculture, Wagga Wagga NSW, 7Department of Plant Science, University of Adelaide, Glen Osmond SA 38. Can we improve grain yield by breeding for greater early vigour in wheat? Tina Botwright1, Tony Condon1, Robin Wilson2 and Iain Barclay2, 1CSIRO Plant Industry, 2Agriculture Western Australia MARKETING AND QUALITY 39. The Crop Improvement Royalty, Howard Carr, Agriculture Western Australia 40. GrainGuardÔ - The development of a protection plan for the wheat industry, Greg Shea, Agriculture Western Australia CLIMATE 41. Rainfall – what happened in 2000 and the prospects for 2001, Ian Foster, Agriculture Western Australia 42. Software for climate management issues, David Tennant,Agriculture Western Australia CONTRIBUTING AUTHOR CONTACT DETAIL

    Corporate Governance for Sustainability

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    The current model of corporate governance needs reform. There is mounting evidence that the practices of shareholder primacy drive company directors and executives to adopt the same short time horizon as financial markets. Pressure to meet the demands of the financial markets drives stock buybacks, excessive dividends and a failure to invest in productive capabilities. The result is a ‘tragedy of the horizon’, with corporations and their shareholders failing to consider environmental, social or even their own, long-term, economic sustainability. With less than a decade left to address the threat of climate change, and with consensus emerging that businesses need to be held accountable for their contribution, it is time to act and reform corporate governance in the EU. The statement puts forward specific recommendations to clarify the obligations of company boards and directors and make corporate governance practice significantly more sustainable and focused on the long term

    Genetic mechanisms of critical illness in COVID-19.

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    Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

    Functional neuroanatomy of speech signal decoding in primary progressive aphasias

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    This work was supported by the Alzheimer’s Society (AS-PG-16-007), the National Institute for Health Research University College London Hospitals Biomedical Research Centre (CBRC 161), the UCL Leonard Wolfson Experimental Neurology Centre (PR/ ylr/18575), and the Economic and Social Research Council (ES/ K006711/1). Individual authors were supported by the Medical Research Council (PhD Studentship to CJDH; MRC Clinician Scientist Fellowship to JDR), the Wolfson Foundation (Clinical Research Fellowship to CRM), the National Brain AppealeFrontotemporal Dementia Research Fund (CNC), Alzheimer’s Research UK (ARTSRF2010-3 to SJC), and the Wellcome Trust (091673/Z/10/Z to JDW)

    ECLAIRE: Effects of Climate Change on Air Pollution Impacts and Response Strategies for European Ecosystems. Project final report

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    The central goal of ECLAIRE is to assess how climate change will alter the extent to which air pollutants threaten terrestrial ecosystems. Particular attention has been given to nitrogen compounds, especially nitrogen oxides (NOx) and ammonia (NH3), as well as Biogenic Volatile Organic Compounds (BVOCs) in relation to tropospheric ozone (O3) formation, including their interactions with aerosol components. ECLAIRE has combined a broad program of field and laboratory experimentation and modelling of pollution fluxes and ecosystem impacts, advancing both mechanistic understanding and providing support to European policy makers. The central finding of ECLAIRE is that future climate change is expected to worsen the threat of air pollutants on Europe’s ecosystems. Firstly, climate warming is expected to increase the emissions of many trace gases, such as agricultural NH3, the soil component of NOx emissions and key BVOCs. Experimental data and numerical models show how these effects will tend to increase atmospheric N deposition in future. By contrast, the net effect on tropospheric O3 is less clear. This is because parallel increases in atmospheric CO2 concentrations will offset the temperature-driven increase for some BVOCs, such as isoprene. By contrast, there is currently insufficient evidence to be confident that CO2 will offset anticipated climate increases in monoterpene emissions. Secondly, climate warming is found to be likely to increase the vulnerability of ecosystems towards air pollutant exposure or atmospheric deposition. Such effects may occur as a consequence of combined perturbation, as well as through specific interactions, such as between drought, O3, N and aerosol exposure. These combined effects of climate change are expected to offset part of the benefit of current emissions control policies. Unless decisive mitigation actions are taken, it is anticipated that ongoing climate warming will increase agricultural and other biogenic emissions, posing a challenge for national emissions ceilings and air quality objectives related to nitrogen and ozone pollution. The O3 effects will be further worsened if progress is not made to curb increases in methane (CH4) emissions in the northern hemisphere. Other key findings of ECLAIRE are that: 1) N deposition and O3 have adverse synergistic effects. Exposure to ambient O3 concentrations was shown to reduce the Nitrogen Use Efficiency of plants, both decreasing agricultural production and posing an increased risk of other forms of nitrogen pollution, such as nitrate leaching (NO3-) and the greenhouse gas nitrous oxide (N2O); 2) within-canopy dynamics for volatile aerosol can increase dry deposition and shorten atmospheric lifetimes; 3) ambient aerosol levels reduce the ability of plants to conserve water under drought conditions; 4) low-resolution mapping studies tend to underestimate the extent of local critical loads exceedance; 5) new dose-response functions can be used to improve the assessment of costs, including estimation of the value of damage due to air pollution effects on ecosystems, 6) scenarios can be constructed that combine technical mitigation measures with dietary change options (reducing livestock products in food down to recommended levels for health criteria), with the balance between the two strategies being a matter for future societal discussion. ECLAIRE has supported the revision process for the National Emissions Ceilings Directive and will continue to deliver scientific underpinning into the future for the UNECE Convention on Long-range Transboundary Air Pollution
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