827 research outputs found

    Radio Planetary Nebulae in the Large Magellanic Cloud

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    We present 21 new radio-continuum detections at catalogued planetary nebula (PN) positions in the Large Magellanic Cloud (LMC) using all presently available data from the Australia Telescope Online Archive at 3, 6, 13 and 20 cm. Additionally, 11 previously detected LMC radio PNe are re-examined with 7 7 detections confirmed and reported here. An additional three PNe from our previous surveys are also studied. The last of the 11 previous detections is now classified as a compact \HII\ region which makes for a total sample of 31 radio PNe in the LMC. The radio-surface brightness to diameter (Σ\Sigma-D) relation is parametrised as Σ∝D−β\Sigma \propto {D^{ - \beta }}. With the available 6~cm Σ\Sigma-DD data we construct Σ\Sigma-DD samples from 28 LMC PNe and 9 Small Magellanic Cloud (SMC) radio detected PNe. The results of our sampled PNe in the Magellanic Clouds (MCs) are comparable to previous measurements of the Galactic PNe. We obtain β=2.9±0.4\beta=2.9\pm0.4 for the MC PNe compared to β=3.1±0.4\beta = 3.1\pm0.4 for the Galaxy. For a better insight into sample completeness and evolutionary features we reconstruct the Σ\Sigma-DD data probability density function (PDF). The PDF analysis implies that PNe are not likely to follow linear evolutionary paths. To estimate the significance of sensitivity selection effects we perform a Monte Carlo sensitivity simulation on the Σ\Sigma-DD data. The results suggest that selection effects are significant for values larger than β∼2.6\beta \sim 2.6 and that a measured slope of β=2.9\beta=2.9 should correspond to a sensitivity-free value of ∼3.4\sim 3.4.Comment: 19 pages, 9 figures, 6 table

    CCRS proposal for evaluating LANDSAT-4 MSS and TM data

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    The measurement of registration errors in LANDSAT MSS data is discussed as well as the development of a revised algorithm for the radiometric calibration of TM data and the production of a geocoded TM image

    Immunity to larval Brugia malayi in BALB/c mice: protective immunity and inhibition of larval development.

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    The objective of this study was to analyze the immune response of mice to the larval stages of Brugia malayi. Male BALB/c mice were inoculated with 3 doses of irradiated third-stage larvae (L-3) of B. malayi and were subsequently challenged with L-3 implanted ip within diffusion chambers. After 3 weeks, larvae were recovered to determine their viability, length, and stage of development. A significant reduction in parasite survival was observed in immunized mice. Furthermore, larvae recovered from immunized mice were significantly shorter than larvae recovered from control mice. All larvae recovered from immunized mice were L-3, whereas 96% of larvae recovered from controls were fourth-stage larvae (L-4). Sera collected from control and immunized mice were tested for the presence of antibodies reactive with L-3 and L-4 antigens using an indirect fluorescent antibody assay employing frozen larval cross-sections as antigen. Sera recovered after challenge of control mice reacted with internal, but not surface, antigens of L-3 and L-4. Alternatively, sera from immunized mice reacted with both internal and external antigens of both L-3 and L-4

    Non-spherical optically trapped probes: Design, control, and applications

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    In this proceedings paper we show describe how a microtool can be assembled, and tracked in three dimensions such that its full rotational and translational coordinates, q, are recovered. This allows tracking of the motion of any arbitrary point, d, on the microtool's surface. When the micro-tool is held using multiple optical traps the motion of such a point investigates the inside of an ellipsoidal volume - we term this a 'thermal ellipsoid. We demonstrate how the shape of this thermal ellipsoid may be controlled by varying the relative trapping power of the optical traps, and adjusting the angle at which the micro-tool is held relative to the focal plane. Our experimental results follow the trends derived by Simpson and Hanna

    Holistic corpus-based dialectology

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    This paper is concerned with sketching future directions for corpus-based dialectology. We advocate a holistic approach to the study of geographically conditioned linguistic variability, and we present a suitable methodology, 'corpusbased dialectometry', in exactly this spirit. Specifically, we argue that in order to live up to the potential of the corpus-based method, practitioners need to (i) abandon their exclusive focus on individual linguistic features in favor of the study of feature aggregates, (ii) draw on computationally advanced multivariate analysis techniques (such as multidimensional scaling, cluster analysis, and principal component analysis), and (iii) aid interpretation of empirical results by marshalling state-of-the-art data visualization techniques. To exemplify this line of analysis, we present a case study which explores joint frequency variability of 57 morphosyntax features in 34 dialects all over Great Britain
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