2,686 research outputs found

    Can the mid-Holocene provide suitable models for rewilding the landscape in Britain?

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    Palaeoecologists have been encouraging us to think about the relevance of the Holocene fossil record for nature conservation for many years (e.g. Buckland 1993) but this information seems slow to filter through to the conservation community. Indeed, Willis et al. (2005) report that recently published biodiversity reports and policy documents rarely look back more than 50 years and may ignore the historical context entirely. This has been a lost opportunity for understanding ecological systems. Many natural processes occur over timescales that confound our attempts to understand them, so the vast temporal perspective provided by palaeoecological studies can provide important guidance for nature conservation (Willis & Birks 2006). However, accurate vegetation mapping is difficult enough in modern landscapes (Cherrill & McLean 1999), so the challenge of describing prehistoric environments is immeasurably greater. Nevertheless, pioneering work in the mid 20th century showed that pollen and spores extracted from peat bogs were so perfectly preserved thatthey could be used to demonstrate sequences of vegetation change since the last glaciation (Godwin 1956). Since then, the science has burgeoned: ancient deposits of beetles, snails, fungal spores and plant macrofossils add to the picture, as does the chemistry of ancient lake sediments (Bell & Walker 2004). Many questions still remain to be answered by this fascinating research and one aspect has received considerable attention in the last decade. This concerns the nature of the ‘primeval’ landscapes, in other words our understanding of natural systems prior to significant human impact. The debate was kindled by a thesis by the Dutch forest ecologist Frans Vera in 2000 (see also Vera & Buissink 2007). Vera effectively challenged established views about the primeval landscapes and argued that the refutation, and the resulting alternative landscape models, had critical importance for modern conservation practice. Vera’s thesis is focused on the pre-Neolithic (ca 8000-5000bp) landscape in the lowlands of central and western Europe, with the assumption that this period represents an almost pristine or ‘natural’ state which should provide a suitable conservation benchmark. Vera contends (i) that this landscape was not closed woodland but a relatively open park-like mosaic of wood and grassland,and (ii) that large wild herbivores were an essential driving force behind woodland-grassland vegetation cycles. The advocacy in his argument and the timing of the publication, when grazingwas seen as increasingly important in conservation in Europe, have combined to raise the profile of this issue. If Vera is correct, the open park-like landscapes were inherited rather than created by people; this may have implications for conservation practice in Europe. The adoption of Vera’s ideas into conservation management plans in the UK (see Box 1) gives an indication of the influence that this work has had. Indeed, Vera’s ideas have been described as a ‘challenge to orthodox thinking’ (Miller 2002) and considerable debate has been stimulated centering on the ecological validity of Vera’s hypothesis and its relevance for modern conservation. In this article, we attempt to address these issues on the basis of results from a literature review, web-debate and discussions with Dutch and British ecologists, prepared for English Nature with a view to informing conservation strategies (Hodder & Bullock 2005a)

    An Approach to Agent-Based Service Composition and Its Application to Mobile

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    This paper describes an architecture model for multiagent systems that was developed in the European project LEAP (Lightweight Extensible Agent Platform). Its main feature is a set of generic services that are implemented independently of the agents and can be installed into the agents by the application developer in a flexible way. Moreover, two applications using this architecture model are described that were also developed within the LEAP project. The application domain is the support of mobile, virtual teams for the German automobile club ADAC and for British Telecommunications

    Preliminary archaeoentomological analyses of permafrost-preserved cultural layers from the pre-contact Yup’ik Eskimo site of Nunalleq, Alaska : implications, potential and methodological considerations

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    Acknowledgements Site excavation and samples collection were conducted by archaeologists from the University of Aberdeen, with the help of archaeologists and student excavators from the University of Aberdeen University of Alaska Fairbanks and Bryn Mawr College, Kuskokwim Campus, College of Rural Alaska and residents of Quinhagak and Mekoryuk. This study is funded through AHRC grant to the project ‘Understanding Cultural Resilience and Climate Change on the Bering Sea through Yup’ik Ecological Knowledge, Lifeways, Learning and Archaeology’ to Rick Knecht, Kate Britton and Charlotta Hillderal (University of Aberdeen; AH/K006029/1). Thanks are due to Qanirtuuq Inc. and Quinhagak, Alaska for sampling permissions and to entomologists working at the CNC in Ottawa for allowing access to reference collections of beetles, lice and fleas. Yves Bousquet, Ales Smetana and Anthony E. Davies are specially acknowledged for their help with the identification of coleopteran specimens. Finally, we would also like to thank Scott Elias for useful comments on the original manuscript.Peer reviewedPublisher PD

    Women with a low satiety phenotype show impaired appetite control and greater resistance to weight loss.

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    AbstractThis trial compared weight loss outcomes over 14-weeks in women showing low or high satiety responsiveness [low or high satiety phenotype (LSP, HSP)] measured by a standardized protocol. Food preferences and energy intake after low and high energy density (LED, HED) meals were also assessed. Ninety-six women (n = 52 analysed; 41.24 ± 12.54 years; 34.02 ± 3.58 kg/m2) engaged in one of two weight loss programs underwent LED and HED laboratory-test days during weeks 3 and 12. Preferences for LED and HED-foods (Leeds Food Preference Questionnaire) and ad libitum evening meal and snack energy intake (EI) were assessed in response to equi-caloric LED- and HED-breakfasts and lunches. Weekly questionnaires assessed control over eating and ease of adherence to the program. Satiety quotients based on subjective fullness ratings post-LED and HED breakfasts determined LSP (n=26) and HSP (n=26) by tertile splits. Results showed that the LSP lost less weight and had smaller reductions in waist circumference compared to HSP. The LSP showed greater preferences for HED-foods, and under HED-conditions, consumed more snacks (kcal) compared to HSP. Snack EI did not differ under LED-conditions. LSP reported less control over eating and reported more difficulty with program adherence. In conclusion, low satiety responsiveness is detrimental for weight loss. LED meals can improve self-regulation of EI in the LSP, which may be beneficial for longer-term weight control.</jats:p

    Model-Independent Comparison of Direct vs. Indirect Detection of Supersymmetric Dark Matter

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    We compare the rate for elastic scattering of neutralinos from various nuclei with the flux of upward muons induced by energetic neutrinos from neutralino annihilation in the Sun and Earth. We consider both scalar and axial-vector interactions of neutralinos with nuclei. We find that the event rate in a kg of germanium is roughly equivalent to that in a 10510^5- to 10710^7-m2^2 muon detector for a neutralino with primarily scalar coupling to nuclei. For an axially coupled neutralino, the event rate in a 50-gram hydrogen detector is roughly the same as that in a 10- to 500-m2^2 muon detector. Expected experimental backgrounds favor forthcoming elastic-scattering detectors for scalar couplings while the neutrino detectors have the advantage for axial-vector couplings.Comment: 10 pages, self-unpacking uuencoded PostScript fil

    Exploring the behavioural drivers of veterinary surgeon antibiotic prescribing: a qualitative study of companion animal veterinary surgeons in the UK

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    Background: Multi-drug resistant bacteria are an increasing concern in both human and veterinary medicine. Inappropriate prescribing and use of antibiotics within veterinary medicine may be a contributory factor to antimicrobial resistance (AMR). The ‘One Health’ Initiative aims to work across species and environments to reduce AMR, however; little is currently known about the factors which influence antibiotic prescribing among veterinary surgeons in companion animal practice. This paper reports on qualitative data analysis of interviews with veterinary surgeons whose practice partially or wholly focuses on companion animals (N = 16). The objective of the research was to explore the drivers of companion animal veterinary surgeons’ antibiotic prescribing behaviours. The veterinary surgeons interviewed were all practising within the UK (England (n = 4), Scotland (n = 11), Northern Ireland (n = 1)). A behavioural thematic analysis of the data was undertaken, which identified barriers and facilitators to specific prescribing-related behaviours. Results: Five components of prescribing behaviours were identified: 1) confirming clinical need for antibiotics; 2) responding to clients; 3) confirming diagnosis; 4) determining dose, duration and type of antibiotic; and 5) preventing infection around surgery (with attendant appropriate and inappropriate antibiotic prescribing behaviours). Barriers to appropriate prescribing identified include: business, diagnostic, fear, habitual practice and pharmaceutical factors. Facilitators include: AMR awareness, infection prevention, professional learning and regulation and government factors. Conclusion: This paper uses a behavioural lens to examine drivers which are an influence on veterinary surgeons’ prescribing behaviours. The paper contributes new understandings about factors which influence antibiotic prescribing behaviours among companion animal veterinary surgeons. This analysis provides evidence to inform future interventions, which are focused on changing prescribing behaviours, in order to address the pressing public health concern of AMR

    First Dark Matter Search Results from a Surface Run of the 10-L DMTPC Directional Dark Matter Detector

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    The Dark Matter Time Projection Chamber (DMTPC) is a low pressure (75 Torr CF4) 10 liter detector capable of measuring the vector direction of nuclear recoils with the goal of directional dark matter detection. In this paper we present the first dark matter limit from DMTPC. In an analysis window of 80-200 keV recoil energy, based on a 35.7 g-day exposure, we set a 90% C.L. upper limit on the spin-dependent WIMP-proton cross section of 2.0 x 10^{-33} cm^{2} for 115 GeV/c^2 dark matter particle mass.Comment: accepted for publication in Physics Letters
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