18 research outputs found

    Ethnomycological notes from Papua New Guinea

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    The literature on the use of psychotropic fungi in the Western Highlands of Papua New Guinea has been reviewed. An attempt has been made to evaluate whether the previously reported “mushroom madness” still exists in the Waghi Valley. Interviews with the local population indicated that most of the indigenous knowledge about the psychotropic effects of fungi has been lost

    Stellar Kinematics and Populations of Early-Type Galaxies with the SAURON and OASIS Integral-Field Spectrographs

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    We summarise the results and achievements of integral-field spectroscopy of early-type galaxies, observed as part of a survey using both the SAURON and OASIS spectrographs. From the perspective of integral-field spectroscopy, these otherwise smooth and featureless objects show a wealth of structure, both in their stellar kinematics and populations. We focus on the stellar content, and examine properties on both kiloparsec scales with SAURON, and scales of 100's of parsecs with OASIS. These complementary studies reveal two types of kinematically distinct components (KDCs), differing primarily in their intrinsic sizes. In previous studies, KDCs and their host galaxies have generally been found to be unremarkable in other aspects. We show that large KDCs, typical of the well-studied cases, indeed show little or no age differences with their host galaxy. The KDCs detected with the higher spatial-resolution of OASIS are intrinsically smaller and include, in contrast, a significant fraction of young stars. We speculate on the relationship between KDCs and their host galaxies, and the implications for young populations in early-type galaxies.Comment: 20 pages, 6 figures. Invited talk, submitted to "Adaptive Optics-Assisted Integral-Field Spectroscopy", Rutten R.G.M., Benn C.R., Mendez J., eds., May 2005, La Palma (Spain), New Astr. Rev. For full resolution PS, see http://www.strw.leidenuniv.nl/~mcdermid/mcdermid_ao_workshop_20050830.ps.g

    Land of the Unexpected: Impressions from Papua New Guinea

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    Join Dr. Roland Treu, Associate Professor, Biology, Centre for Science, on a journey through the Melanesian paradise of Papua New Guinea, a little known country in the south Pacific with a startling biodiversity. Drawing on research conducted over six years, Roland will introduce the natural history of the area and its people with their unique traditions. Threatened natural treasures will be discussed, including why more than 700 languages may soon vanish from the earth

    Membrane damage-responsive biosensors for the discovery of antimicrobials from Lenzites betulina and Haploporus odorus

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    Antibiotic resistance of pathogens to antibiotics is a growing concern in medical treatment of infections. Conventional methods for antimicrobial screening relies on using disc diffusion to observe zones of inhibition. However, this method is not sensitive enough to possibly detect sub-lethal activities. We have developed biosensors in Pseudomonas aeruginosa that produce light from transcriptional lux fusions in response to compounds that damage the outer membrane. Sub-lethal exposure to antimicrobial peptides, the antibiotic cycloserine, and cation chelators induces the expression of arnC::lux (PA3553) and speE2::lux (PA4774). These genes encode outer surface modifications that ultimately protect the P. aeruginosa outer membrane from exposure to sub-lethal concentrations of membrane-active compounds. We used high throughput screening in 96 well micro plate format to test the culture supernatants from a panel of fungal species isolated in Alberta. Preliminary results showed a significant induction of both strains of lux biosensors in 23 of the 29 fungal species screened. Due to the significant amount of biosensor induction induced by the supernatants from Lenzites betulina and Haploporus odorus, efforts have been directed to the purification, isolation and classification of the active component of the supernatant. Whole genome sequencing has become necessary in order to properly analyze the mass spectrometry results that have already been obtained. In a short period of time, it has been possible to quickly and more accurately detect sub-lethal concentrations of antimicrobial compounds that might have been over looked if tradition methods, such as disc diffusion, had been employed. * Indicates faculty mento

    The SAURON project – XIII. SAURON–GALEX study of early-type galaxies: the ultraviolet colour–magnitude relations and Fundamental Planes

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    ‘The definitive version is available at www3.interscience.wiley.com '. Copyright Royal Astronomical Society. DOI: 10.1111/j.1365-2966.2009.15238.xWe present Galaxy Evolution Explorer far-ultraviolet (FUV) and near-ultraviolet (NUV) imaging of 34 nearby early-type galaxies from the SAURON representative sample of 48 E/S0 galaxies, all of which have ground-based optical imaging from the MDM Observatory. The surface brightness profiles of nine galaxies (≈26 per cent) show regions with blue UV−optical colours suggesting RSF. Five of these (≈15 per cent) show blue integrated UV–optical colours that set them aside in the NUV integrated colour–magnitude relation. These are objects with either exceptionally intense and localized NUV fluxes or blue UV−optical colours throughout. They also have other properties confirming they have had RSF, in particular Hβ absorption higher than expected for a quiescent population and a higher CO detection rate. This suggests that residual star formation is more common in early-type galaxies than we are used to believe. NUV blue galaxies are generally drawn from the lower stellar velocity dispersion (σe < 200 km s−1) and thus lower dynamical mass part of the sample. We have also constructed the first UV Fundamental Planes and show that NUV blue galaxies bias the slopes and increase the scatters. If they are eliminated, the fits get closer to expectations from the virial theorem. Although our analysis is based on a limited sample, it seems that a dominant fraction of the tilt and scatter of the UV Fundamental Planes is due to the presence of young stars in preferentially low-mass early-type galaxies. Interestingly, the UV–optical radial colour profiles reveal a variety of behaviours, with many galaxies showing signs of RSF, a central UV-upturn phenomenon, smooth but large-scale age and metallicity gradients and in many cases a combination of these. In addition, FUV−NUV and FUV−V colours even bluer than those normally associated with UV-upturn galaxies are observed at the centre of some quiescent galaxies. Four out of the five UV-upturn galaxies are slow rotators. These objects should thus pose interesting challenges to stellar evolutionary models of the UV upturn.Peer reviewe
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