56 research outputs found

    The distribution of Bibionidae (Diptera) in Scotland

    Get PDF
    We review the material of the family Bibionidae from Scotland in the Natural History Museum, London and the National Museums of Scotland, Edinburgh, as well as some material from other collections and published records from the SIRI (Scottish Insect Records Index). Eleven species of the genus Bibio Geoffroy, 1762 and four species in the genus Dilophus Meigen, 1803 have been collected in Scotland. We review the distribution and ecology of each species and present maps of records. Previous Scottish records of Bibio hortulanus (Linnaeus, 1758) and B. reticulatus Loew, 1846 are deemed to be most likely erroneous. Additionally, we have not found any specimens confirming the literature record of Bibio venosus (Meigen, 1804), but we believe this record is most likely correct since this species is distinctive and well defined with no substantial confusion about its identity. There is also a recent record of Dilophus humeralis Zetterstedt, 1850 which we have not been able to confirm. The following species have unambiguous records from Scotland: Bibio clavipes Meigen, 1818; B. ferruginatus (Linnaeus, 1758); B. johannis (Linnaeus, 1767); B. lanigerus Meigen, 1818; B. leucopterus (Meigen, 1804); B. longipes Loew, 1864; B. marci (Linnaeus, 1758); B. nigriventris Haliday, 1833; B. pomonae (Fabricius, 1775); B. varipes Meigen, 1830; Dilophus bispinosus Lundström, 1913; D. febrilis (Linnaeus, 1758); D. femoratus Meigen, 1804

    The cascading impacts of livestock grazing in upland ecosystems: a 10-year experiment

    Get PDF
    ACKNOWLEDGMENTS We thank The Woodland Trust, Scotland for permission to use the Glen Finglas Estate. Sally Burgess, Timothy Conner, Charlie Gardner, Ian Joyce,Fi Leckie, Elaine McEwan, Ruth Mitchell, Gabor Pozsgai, Gina Prior and others assisted with the collection and sorting of samples at different stages of the project. S. M. Redpath, R. J. Pakeman, P. Dennis and D. M. Evans designed the study; D. M. Evans, N.Villar, N. A. Littlewood, S. A. Evans and J. Skartveit collected the data; D. M. Evans and N. Villar analyzed the data; D. M. Evans and N. Villar co-wrote as joint-first authors the first draft of the manuscript, and all authors contributed substantially to revisions.Peer reviewedPublisher PD

    An all-sky radiative transfer method to predict optimal tilt and azimuth angle of a solar collector

    Get PDF
    This paper describes a radiative transfer method for calculating radiances in all-sky conditions and performing an integration over the view hemisphere of an arbitrary plane to calculate tilted irradiance. The advantage of this method is the combination of cloud parameters inside the radiative transfer model with a tilt procedure. For selected locations this method is applied with cloud, ozone, water vapour and aerosol input data to determine tilted irradiance, horizontal irradiance and optimal tilt angle. A validation is performed for horizontal and tilted irradiance against high-quality pyranometer data. For 27 sites around the world, the annual horizontal irradiation predicted by our model had a mean bias difference of +0.56% and a root-mean-squared difference of 6.69% compared to ground measurements. The difference between the annual irradiation estimates from our model and the measurements from one site that provides tilted irradiance were within ±6% for all orientations except the north-facing vertical plane. For European and African sites included in the validation, the optimal tilt from our model is typically a few degrees steeper than predictions from the popular PVGIS online tool. Our model is generally applicable to any location on the earth’s surface as the satellite cloud and atmosphere data and aerosol climatology data are available globally. Furthermore, all of the input data are standard variables in climate models and so this method can be used to predict tilted irradiance in future climate experiments

    Refugee artists and memories of displacement: a visual semiotics analysis

    Get PDF
    This paper considers the ways in which refugee artists represent the experience of displacement, their cultural traditions and the longing for home through paintings and how, by doing so, they become the visual interpreters of the current refugee crisis. The starting point of this article is that little attention has been paid towards the visual narratives of artworks produced by refugee artists and shared on social media. Through the visual semiotics analysis of 150 images of paintings (exhibited on the Facebook page Syria.Art) and through a number of individual interviews with the artists themselves, the article identifies three emerging visual narratives. These are concerned primarily with reminiscences about people, places and cultural practices lost (or in danger of being lost) because of the forced journey and because of the displacement. Within this context, these visual discourses become part of an open repository, which mediates, re-organises and preserves memories, both personal and collective as a form of emotional survival and resilience. It is argued that these visual narratives and representations nurture empathy for the human condition of the refugees and universalise the migrant experience
    • 

    corecore