1,565 research outputs found

    Report on trial of SatScan tray scanner system by SmartDrive Ltd.

    Get PDF
    Smartdrive Ltd. has developed a prototype imaging system, SatScan, that captures digitised images of large areas while keeping smaller objects in focus at very high resolution. The system was set up in the Sackler Biodiversity Imaging laboratory of Natural History Museum on March 8, 2010 for a one-month trial. A series of projects imaging parts of the entomological, botanical and palaeoentomological collection were conducted to assess the systems utility for museum collection management and biodiversity research. The technical and practical limitations of the system were investigated as part of this process

    The Amazon Flood Plain Forest Tree Maquira coriacea (Karsten) C.C. Berg: Aspects of Ecology and Management

    Get PDF
    Maquira coriacea is a commercial tree species growing throughout the Amazon flood plain forests. Densities up to 14/ha of individuals, >10 cm diameter at breast height (DBH) were observed, corresponding to a basal area of 2 m2/ha and a volume of 38 m3/ha. The primary period of fruiting coincided with the annual flooding, but fruits were also produced in other parts of the year. Seedlings with densities up to 150/m2 were concentrated around mother trees, and the stocks fluctuated much over the year due to mortality caused by flooding and wilting in dry periods. Growth data mainly from nine 1 ha permanent sample plots were used to develop models of the height-diameter relationship and diameter increment. These relationships indicated that the optimal felling limit for maximum volume production was 120-130 cm DBH, which can be obtained in 150-260 years. Since seed production has been observed in much smaller individuals, such diameter limits should not be detrimental to regeneration

    Histopathologic alterations associated with the transplanted homologous dog liver

    Get PDF
    Homotransplanted livers in dogs developed mononuclear, lymphocytic and plasmacytic infiltration and hepatic cell degeneration roughly paralleling survival time. Extensive histologic alterations of host reticuloendothelial structures occurred. Proliferation and infiltration of mononuclear cells, principally plasmacytes, were noted in lung, kidney, perirenal supportive tissue, bone marrow, and lymph nodes. Lymph nodes, in addition, were characterized by cortical and follicular depletion. These changes were considered to represent extensive host reticuloendothelial mobilization coincident to liver homotransplant rejection. The relation between these alterations and those found in other hypersensitivity states is discussed. © 1962

    The significance of guinea worm infection in the immunological diagnosis of onchocerciasis and bancroftian filariasis

    Get PDF
    Infections with Dracunculus medinensis frequently occur in the same geographical area as infections with Onchocerca volvulus and Wuchereria bancrofti. This study analysed the significance of D. medinensis infections for the specificity and sensitivity of available tests for antibody-based diagnosis of onchocerciasis (using individual recombinant clones OV-10, OV-11 and OV-16, and the OV-7/OV-10/OV-16 tri-cocktail, in an enzyme-linked immunosorbent assay) and for circulating antigen-based diagnosis of bancroftian filariasis (using the TroBio™ and the ICT™ card tests). Some immunological cross-reactivity was observed with all tests. When using individual recombinant O. volvulus antigens, the highest assay indices were obtained for clone OV-10, and the lowest for clone OV-16. Testing the serum responses against the tri-cocktail of recombinant antigens did not notably improve the assay indices. Two of 40 serum samples from individuals with patent dracunculiasis gave a false positive response in the ICT™ test and one of these was also positive in the TropBio™ test. Possible implications of applying these diagnostic assays in areas endemic for dracunculiasis are discusse

    Effect of Particle Morphology on the Ripening of Supported Pt Nanoparticles

    Get PDF
    To improve the understanding of sintering in diesel and lean-burn engine exhaust aftertreatment catalysts, we examined oxygen-induced sintering in a model catalyst consisting of Pt nanoparticles supported on a planar, amorphous Al2O3 substrate. After ageing at increasing temperatures, transmission electron microscopy analysis reveals that highly monodisperse ensembles of nanoparticles transformed into ensembles with bimodal and subsequently Lifshitz-Slyozov-Wagner particle size distributions. Moreover, scanning transmission electron microscopy and atomic force microscopy analysis suggest that the Pt nanoparticles have size-dependent morphologies after sintering in oxidizing environment. The evolution of the particle sizes is described by a simple kinetic model for ripening and the size-dependent particle morphology is proposed as an explanation for the observed bimodal particle size distribution shapes
    corecore