1,090 research outputs found

    Checklist of British and Irish Hymenoptera - aculeates (Apoidea, Chrysidoidea and Vespoidea)

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    Background: The checklist of British and Irish aculeate Hymenoptera (Apoidea, Chrysidoidea and Vespoidea) is revised. Species distribution is summarised for all species at the level of country (England, Scotland, Wales, Ireland and Isle of Man). New information: The 601 native species represent an increase of 25 on the 1978 checklist, comprising mostly new discoveries. This increase is nearly balanced by the 23 species now presumed to be extinct in Britain and Ireland.This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.NHM Repositor

    The role of bioenergy for global deep decarbonisation: CO 2 removal or low‐carbon energy?

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    Bioenergy is expected to have a prominent role in limiting global greenhouse emissions to meet the climate change target of the Paris Agreement. Many studies identify negative emissions from bioenergy with carbon capture and storage (BECCS) as its key contribution, but assume that no other CO2 removal technologies are available. We use a global integrated assessment model, TIAM‐UCL, to investigate the role of bioenergy within the global energy system when direct air capture and afforestation are available as cost‐competitive alternatives to BECCS. We find that the presence of other CO2 removal technologies does not reduce the pressure on biomass resources but changes the use of bioenergy for climate mitigation. While we confirm that when available BECCS offers cheaper decarbonisation pathways, we also find that its use delays the phase‐out of unabated fossil fuels in industry and transport. Further, it displaces renewable electricity generation, potentially increasing the likelihood of missing the Paris Agreement target. We found that the most cost‐effective solution is to invest in a basket of CO2 removal technologies. However, if these technologies rely on CCS, then urgent action is required to ramp up the necessary infrastructure. We conclude that a sustainable biomass supply is critical for decarbonising the global energy system. Since only a few world regions carry the burden of producing the biomass resource and store CO2 in geological storage, adequate international collaboration, policies, and standards will be needed to realise this resource while avoiding undesired land‐use change

    A Discrete Version of the Inverse Scattering Problem and the J-matrix Method

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    The problem of the Hamiltonian matrix in the oscillator and Laguerre basis construction from the S-matrix is treated in the context of the algebraic analogue of the Marchenko method.Comment: 11 pages. The Laguerre basis case is adde

    Representation of a complex Green function on a real basis: I. General Theory

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    When the Hamiltonian of a system is represented by a finite matrix, constructed from a discrete basis, the matrix representation of the resolvent covers only one branch. We show how all branches can be specified by the phase of a complex unit of time. This permits the Hamiltonian matrix to be constructed on a real basis; the only duty of the basis is to span the dynamical region of space, without regard for the particular asymptotic boundary conditions that pertain to the problem of interest.Comment: about 40 pages with 5 eps-figure

    Biological Records Centre Annual Report 2005-2006

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    The period covered by this report is the first year of a new six-year partnership between CEH and JNCC. For this period, there is increased emphasis on targeted survey, on analysis and interpretation and on communications and outreach. These activities were always part of BRC’s work, but they have been given greater prominence as a result of rapid developments in information technology. Data are increasingly reaching BRC in electronic form, so that the effort of data entry and collation is reduced. The data, collected by many volunteers and then collated and analysed at BRC, document the changing status and distribution of plants and animals in Britain. Distribution maps are published in atlases and are available via the internet through the NBN Gateway. The effects of change or loss of habitats, the influence of climate change and the consequences of changing water quality are all examples of the environmental factors that affect our biodiversity and which BRC aims to document and understand. The results are vital for developing environmental policies, to support conservation, and for fundamental ecological research. BRC is funded jointly by JNCC and NERC through a partnership based on a Memorandum of Agreement (MoA). The partnership started in 1973 when the Nature Conservancy was divided to form the successor bodies Nature Conservancy Council (NCC) and Institute of Terrestrial Ecology (ITE). NCC was in turn divided further to form JNCC and three Country Agencies, while ITE was merged with other NERC units to form CEH. Through all these changes, the partnership has been maintained. A six-year memorandum of agreement ended on 31 January 2005 (Hill et al. 2005). The present report covers the first full year, 2005-6, of the new agreement for 2005-2010. Rapid progress in information technology continues to be highly beneficial for BRC, whose data are increasingly used by the UK country conservation agencies, environmental consultants, NGOs, research workers, policy makers and volunteers. It is gratifying to know that, through our ability to display data on the National Biodiversity Network (NBN) Gateway, some of our data suppliers now have immediate access to their own data in a convenient form. The year 2005-6 has been one of steady progress, with new datasets added to BRC, substantial additions to existing data, and improved communication with the NBN Gateway. The most high profile activity of the year has been the Harlequin Ladybird Survey, which has enabled us to observe the early stages of colonization by a mobile insect in greater detail than has been possible in any previous case
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