355 research outputs found

    Comparison of fungal spores concentrations measured with wideband integrated bioaerosol sensor and Hirst methodology

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    The aim of this work was to provide both a comparison of traditional and novel methodologies for airborne spores detection (i.e. the Hirst Burkard trap and WIBS-4) and the first quantitative study of airborne fungal concentrations in Payerne (Western Switzerland) as well as their relation to meteorological parameters. From the traditional method -Hirst trap and microscope analysis-, sixty-three propagule types (spores, sporangia and hyphae) were identified and the average spore concentrations measured over the full period amounted to 4145 ± 263.0 spores/m3. Maximum values were reached on July 19th and on August 6th. Twenty-six spore types reached average levels above 10 spores/m3. Airborne fungal propagules in Payerne showed a clear seasonal pattern, increasing from low values in early spring to maxima in summer. Daily average concentrations above 5000 spores/m3 were almost constant in summer from mid-June onwards. Weather parameters showed a relevant role for determining the observed spore concentrations. Coniferous forest, dominant in the surroundings, may be a relevant source for airborne fungal propagules as their distribution and predominant wind directions are consistent with the origin. The comparison between the two methodologies used in this campaign showed remarkably consistent patterns throughout the campaign. A correlation coefficient of 0.9 (CI 0.76–0.96) was seen between the two over the time period for daily resolutions (Hirst trap and WIBS-4). This apparent co-linearity was seen to fall away once increased resolution was employed. However at higher resolutions upon removal of Cladosporium species from the total fungal concentrations (Hirst trap), an increased correlation coefficient was again noted between the two instruments (R = 0.81 with confidence intervals of 0.74 and 0.86)

    Electromagnetic Polarizabilities of Nucleons bound in 40^{40}Ca, 16^{16}O and 4^4He

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    Differential cross sections for elastic scattering of photons have been measured for 40^{40}Ca at energies of 58 and 74 MeV and for 16^{16}O and 4^4He at 61 MeV, in the angular range from 45o^o to 150o^o. Evidence is obtained that there are no significant in-medium modifications of the electromagnetic polarizabilities except for those originating from meson exchange currents.Comment: 20 pages including 5 Figure

    Articulating practice through the interview to the double

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    The paper aims to realise the critical potential of the practice lens by contributing to the development of a coherent set of methodologies for investigating work and organisational activity. It does so by introducing and critically assessing the "interview to the double" as a method to articulate and represent practice. After briefly illustrating its history and usage, the paper analyses in depth the setting generated by this unusual interview method. It argues that the nature of the encounter produces narratives that are often morally connoted and idealised in character. As a consequence the method is especially useful to capture the going concerns which orient the conduct of the members and the normative and moral dimension of practice. The paper also shows that because it mimics familiar instruction-giving discursive practices, the method constitutes an effective textual device to convey this moral and normative dimension in a way which remains faithful to its situated and contingent nature of practice

    Recommended Terminology for Aerobiological Studies

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    Aerobiology is an interdisciplinary science where researchers with different backgrounds are involved in different topics related to microorganism, airborne biological particles, e.g. pollen and spores, and phenology. Some concepts, words or expressions used in aerobiology have a clear definition, but are however frequently misused. Therefore, the working group “Quality Control” of the European Aerobiology Society (EAS) and the International Association of Aerobiology (IAA) would like to clarify some of them, their use and presentation

    Real-time pollen identification using holographic imaging and fluorescence measurements

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    Over the past few years, a diverse range of automatic real-time instruments has been developed to respond to the needs of end users in terms of information about atmospheric bioaerosols. One of them, the SwisensPoleno Jupiter, is an airflow cytometer used for operational automatic bioaerosol monitoring. The instrument records holographic images and fluorescence information for single aerosol particles, which can be used for identification of several aerosol types, in particular different pollen taxa. To improve the pollen identification algorithm applied to the SwisensPoleno Jupiter and currently based only on the holography data, we explore the impact of merging fluorescence spectra measurements with holographic images. We demonstrate, using measurements of aerosolised pollen, that combining information from these two sources results in a considerable improvement in the classification performance compared to using only a single source (balanced accuracy of 0.992 vs. 0.968 and 0.878). This increase in performance can be ascribed to the fact that often classes which are difficult to resolve using holography alone can be well identified using fluorescence and vice versa. We also present a detailed statistical analysis of the features of the pollen grains that are measured and provide a robust, physically based insight into the algorithm's identification process. The results are expected to have a direct impact on operational pollen identification models, particularly improving the recognition of taxa responsible for respiratory allergies.</p

    Decarbonylative Cross Coupling of Phthalimides with Diorganozinc Reagents—Efforts Toward Catalysis

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    The decarbonylative coupling of phthalimides with diorganozinc reagents to form o-substituted benzamides has been previously demonstrated as a viable process, but only with stoichiometric nickel(0). Investigations into a number of reaction variables, including solvent, ligand, and substrate substitution, have yielded multiple sets of conditions capable of achieving up to 10 catalyst turnovers, most successfully with the use of electron withdrawing nitrogen substituents on the phthalimide. In addition, these investigations have provided insight into the intermediates within the catalytic cycle and have revealed new approaches to the development of a general catalytic methodology
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