69 research outputs found

    Digital mapping in three dimensional space: geometry, features and access

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    Demand for large-scale digital vector base mapping is high, fuelled by developments in geographical information systems (GIS), spatial databases, and location-aware devices. The representation of real-world features (e.g. buildings, gardens, sheds), their properties and the spatial relationships between them are essential for supporting these types of applications and they provide an enduring focus for GIS research. There is an increasing and inevitable demand for three-dimensional (3D however, many currently-available 3D data tend to focus on visualisation aspects, making them unsuitable for populating 3D feature-based databases for spatial analysis. The thesis considers how 3D data can be structured in order that it may be used to support applications in a GIS context. The guiding design principles used to develop the conceptual model are: establishment of a data repository to which information can be added in an in cremental fashion (in order that progress can be made without the requirement of exhaustive 3D surveys) storage of 3D geometry (facilitating the representation of complex multistorey and juxtaposed building parts) ability to describe different conceptualisations of features (e.g. 'rooms' and 'flats') and the relationships between them seamless treatment of space exterior and interior to buildings (in order to treat all space with equivalence) incorporate pedestrian accessibility (spaces are topologically connected and pedestrian access constraints are embedded) representation of a temporal dimension. The key concept is that of 'urban spaces' (discrete units of space in which human activity can occur) inside and outside buildings within the 3D environment. These are organised into layers whose surface geometries are interpolated, even where height data are poorly resolved. The thesis develops a conceptual model, implements a prototype and then illustrates its use for various applications. Particular emphasis is placed upon applications which require pedestrian access information and the definition and identification of 'spaces' and 'real-world features' in 3D built environments

    Assessment of a carbon dioxide laser for the measurement of thermal nociceptive thresholds following intramuscular administration of analgesic drugs in pain-free female cats

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    Objective: To assess the potential for using a thermal carbon dioxide (CO2) laser to 8 assess anti-nociception in pain-free cats. Animals: Sixty healthy adult female cats with a mean weight (± SD) of 3.3 k g (± 0. 6 11 kg). Methods: This is a prospective, blinded and randomised study. Cats were systematically allocated to one of six treatments 1) saline 0.2 ml/cat; 2) morphine 0.5 mg/kg; 3) buprenorphine 20 μg/kg; 4) medetomidine 2 μg/kg; 5) tramadol 2mg/kg; 6) ketoprofen 2 mg/kg. Latency to respond to thermal stimulation was assessed prior to intramuscular injection and at 6 time periods following injection (15-30; 30-45; 45- 18 60; 60-75; 90-105; 120-135 min). Thermal thresholds were assessed using time to respond behaviourally to stimulation with a 500 mW CO2 laser with maximum latency to respond set at 60 seconds. Differences in response latency for each treatment across the duration of the experiment were assessed using a Friedman's test. Differences between treatments at any given time were assessed using an independent Kruskal-Wallis test. Where significant effects were identified, pair-wise comparisons were conducted at 30-45, 60-75 and 120-135 min to further explain the direction of the effect. Results: Cats treated with morphine (χ2 = 12.90; df = 6; P = 0.045) and tramadol (χ2 = 20.28; df = 6; P = 0.002) showed significant increases in latency to respond over the duration of the test period. However, subsequent pairwise comparisons indicated that latencies at specific time points were only significantly different (P < 0.05) for tramadol at 60-75 and 90-105 min after administration. No significant pairwise comparisons were found within the morphine treatment group. Injection of saline, ketoprofen, medetomidine or buprenorphine showed no significant effect on latency to respond. Conclusions: This project further validates the CO 2 laser technique for use in cats. It can be used for assessment of thermal nociceptive thresholds in pain-free cats after analgesic administration and shows some promise in differentiating amongst analgesic treatments. It may provide a simpler alternative to existing systems although further exploration is required both in terms of its sensitivity and comparative utility (i.e. relative to other thermal threshold systems). Future experiments should seek to quantify the effects of skin temperature and sedation on latency to respond. Given that this technique was found to cause minor skin blistering in individuals that reached the 60 s exposure limit, a cut off time of <45 s is recommended

    βB1-Crystallin: Thermodynamic Profiles of Molecular Interactions

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    β-Crystallins are structural proteins maintaining eye lens transparency and opacification. Previous work demonstrated that dimerization of both βA3 and βB2 crystallins (βA3 and βB2) involves endothermic enthalpy of association (∼8 kcal/mol) mediated by hydrophobic interactions.Thermodynamic profiles of the associations of dimeric βA3 and βB1 and tetrameric βB1/βA3 were measured using sedimentation equilibrium. The homo- and heteromolecular associations of βB1 crystallin are dominated by exothermic enthalpy (-13.3 and -24.5 kcal/mol, respectively).Global thermodynamics of βB1 interactions suggest a role in the formation of stable protein complexes in the lens via specific van der Waals contacts, hydrogen bonds and salt bridges whereas those β-crystallins which associate by predominately hydrophobic forces participate in a weaker protein associations

    Large-scale digital mapping in three dimensional space : geometry, features and access

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Biodiversity

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    Geography, climate, and biodiversity: the history and future of mediterranean-type ecosystems

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    The world’s mediterranean-climate regions all have mild, winter-rain climates that have developed over the past several million years, but beyond these similarities they have distinct geological and evolutionary histories that have shaped the floras of each region. This chapter considers the historical and regional influences that have shaped the floras of MT regions, focusing on South Africa, California and Western Australia. One of the most striking differences is their positions on the respective continents, and their tectonic history, and the absence of a high latitude, terrestrial region bordering South Africa and Australia. As a result, the Cape flora does not have a clearly identified temperate element, in striking contrast with California, and this may contribute to the high level of in-situ radiation in Cape lineages. While radiations have occurred in the sclerophyllous lineages in both areas, the moist-adapted, forest communities tend to be derived from cool-temperate lineages in California and from warm, afrotropical lineages in South Africa. In both cases, these components of the flora represent greater phylogenetic diversity. The absence of temperate land masses adjacent to South Africa and Western Australia result in greater reduction in the area of mediterranean-type climate in the face of 21st century global warming. Other aspects of geology, topography and human land-use impacting the prospects for biodiversity conservation are addressed
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