541 research outputs found

    Review: The Use of Real-Time Fluorescence Instrumentation to Monitor Ambient Primary Biological Aerosol Particles (PBAP)

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    Primary biological aerosol particles (PBAP) encompass many particle types that are derived from several biological kingdoms. These aerosol particles can be composed of both whole living units such as pollen, bacteria, and fungi, as well as from mechanically formed particles, such as plant debris. They constitute a significant proportion of the overall atmospheric particle load and have been linked with adverse health issues and climatic effects on the environment. Traditional methods for their analysis have focused on the direct capture of PBAP before subsequent laboratory analysis. These analysis types have generally relied on direct optical microscopy or incubation on agar plates, followed by time-consuming microbiological investigation. In an effort to address some of these deficits, real-time fluorescence monitors have come to prominence in the analysis of PBAP. These instruments offer significant advantages over traditional methods, including the measurement of concentrations, as well as the potential to simultaneously identify individual analyte particles in real-time. Due to the automated nature of these measurements, large data sets can be collected and analyzed with relative ease. This review seeks to highlight and discuss the extensive literature pertaining to the most commonly used commercially available real-time fluorescence monitors (WIBS, UV-APS and BioScout). It discusses the instruments operating principles, their limitations and advantages, and the various environments in which they have been deployed. The review provides a detailed examination of the ambient fluorescent aerosol particle concentration profiles that are obtained by these studies, along with the various strategies adopted by researchers to analyze the substantial data sets the instruments generate. Finally, a brief reflection is presented on the role that future instrumentation may provide in revolutionizing this area of atmospheric research. Keywords: PBAP; WIBS; UV-APS; BioScout; fluorescence; real-time; bioaerosols

    Airborne Fungal Spore Review, New Advances and Automatisation

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    Fungal spores make up a significant portion of Primary Biological Aerosol Particles (PBAPs) with large quantities of such particles noted in the air. Fungal particles are of interest because of their potential to affect the health of both plants and humans. They are omnipresent in the atmosphere year-round, with concentrations varying due to meteorological parameters and location. Equally, differences between indoor and outdoor fungal spore concentrations and dispersal play an important role in occupational health. This review attempts to summarise the different spore sampling methods, identify the most important spore types in terms of negative effects on crops and the public, the factors affecting their growth/dispersal, and different methods of predicting fungal spore concentrations currently in use

    Developing the Saegusa-Ito cyclisation for the synthesis of difluorinated cyclohexenones

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    Palladium(II)-catalysed cycloalkenylation (Saegusa-Ito cyclisation) has been used for the first time to transform difluorinated silylenol ethers to difluorinated cycloalkenones under mild conditions. The silylenol ether precursors were prepared in two high-yielding steps from trifluoroethanol, and cyclised in moderate to good yields. A combination of air and copper(I) chloride in acetonitrile achieved the turnover of the initial palladium(II) salt, while the provision of an oxygen atmosphere ensured more rapid reaction. Annulations required a minimum level of substitution on the chain, but failed when the alkene was substituted. Annelations allowed a range of n,6-bicyclic systems to be prepared and afforded three products in which heterocycles were fused to the new cyclohexenone. The least substituted system explored underwent cyclisation followed by terminal oxidation to a cyclic enal, which corresponded to a Wacker product of unusual regiochemistry

    The use of local anaesthesia for intrauterine device insertion by health professionals in the UK

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    Background Pain associated with the insertion of an intrauterine device (IUD) is a known barrier to intrauterine contraception use in the UK. It is good practice for health professionals to discuss pain relief and use with women prior to the insertion of an IUD. Objectives This study aimed to determine the prevalence of and reasons for and against the use of local anaesthesia (LA) for IUD insertion. Methods A survey was undertaken using paper questionnaires to determine LA use for IUD insertion by UK health professionals. Results Overall, approximately one quarter (n=129) of all respondents use LA routinely, one quarter hardly ever or never use LA, while the remaining half use it sometimes. Use of LA was more prevalent among health professionals who worked in integrated sexual and reproductive health and contraception-only services, compared to general practice. UK health professionals who hardly ever or never used LA for the insertion of IUDs were more likely to be working in general practice. Conclusions The results of this survey suggest that more UK health professionals need to routinely discuss pain relief and offer this to their patients prior to IUD insertion as part of the care pathway for patients who choose to use intrauterine contraception

    Erratum: Causal Knowledge Promotes Behavioral Self-Regulation: An Example using Climate Change Dynamics (PLoS ONE (2017) 12:9 (E0184480) DOI: 10.1371/Journal.pone.0184480)

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    In the Task overview: Managing a dynamic human-climate system subsection of the Introduction, there is an error in equation 4. There is a factor of Ï„ that is missing from the denominator of the first term that appears on the right-hand side of the equation. Please view the complete, correct equation here [Formula Presented]

    Immunomodulation with IL-4Rα antisense oligonucleotide prevents respiratory syncytial virus-mediated pulmonary disease

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    Respiratory syncytial virus (RSV) causes significant morbidity and mortality in infants worldwide. Severe RSV infections in infants cause bronchiolitis, wheeze, and/or cough and significantly increase the risk for developing asthma. RSV pathogenesis is thought to be due to a Th2-type immune response initiated in response to RSV infection, specifically in the infant. Using a neonatal mouse system as an appropriate model for human infants, we sought to determine whether local inhibition of IL-4Rα expression during primary RSV infection in the neonate would prevent Th2-skewed responses to secondary RSV infection and improve longterm pulmonary function. To reduce IL-4Rα expression, antisense oligonucleotides (ASOs) specific for IL-4Rα were administered intranasally to neonatal mice at the time of primary infection. Mice were initially infected with RSV at 1 wk of age and were reinfected at 6 wk of age. Administration of IL-4Rα ASOs during primary RSV infection in neonatal mice abolished the pulmonary dysfunction normally observed following reinfection in the adult. This ablation of pulmonary dysfunction correlated with a persistent rebalancing of the Th cell compartment with decreased Th2 responses (i.e., reduced goblet cell hyperplasia, Th2 cells, and cytokine secretion) and increased Th1 responses (i.e., elevated Th1 cell numbers and type I Abs and cytokines). Our data support our hypothesis that a reduction in the Th2 immune response during primary infection in neonates prevents Th2-mediated pulmonary pathology initially and upon reinfection and further suggest that vaccine strategies incorporating IL-4Rα ASOs may be of significant benefit to infants. Copyright © 2010 by The American Association of Immunologists, Inc

    Cued detection with compound integration-interruption masks reveals multiple attentional mechanisms

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    The relationship between attention and visual masking was investigated in a cued detection task using a factorial masking manipulation. Stimuli were either unmasked, or were masked with simultaneous (integration) masks, or delayed (interruption) masks, or integration-interruption mask pairs. The cuing effects in detection sensitivity were smallest with unmasked stimuli, intermediate with single masks, and largest with integration-interruption pairs. Large cuing effects in RT were found in all stimulus conditions. The results are inconsistent with general mechanisms of contrast gain and response gain, which do not predict interactions with interruption masks. The data were modeled using the integrated system model of visual attention of P. L. Smith and R. Ratcliff (2009), which provides an account of both RT and accuracy. The model fits suggest the action of two independent attentional mechanisms: an early selection mechanism that enhances the perceptual representation of attended, noisy stimuli, and a late selection mechanism that increases the rate of information transfer to visual short-term memory. The results are consistent with a distributed, multi-locus system of attentional control

    Characterization and modelling of electromagnetic interactions in aircraft

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    This article describes the development of modelling techniques and simulation tools for the electromagnetic (EM) analysis of aircraft. It is shown that hybrid solvers and multi-scale techniques can be used effectively to analyse the EM response of aircraft. The importance of supplementing models with appropriate measurement and characterization techniques for parameter extraction and for validation is also demonstrated

    The Bond-Algebraic Approach to Dualities

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    An algebraic theory of dualities is developed based on the notion of bond algebras. It deals with classical and quantum dualities in a unified fashion explaining the precise connection between quantum dualities and the low temperature (strong-coupling)/high temperature (weak-coupling) dualities of classical statistical mechanics (or (Euclidean) path integrals). Its range of applications includes discrete lattice, continuum field, and gauge theories. Dualities are revealed to be local, structure-preserving mappings between model-specific bond algebras that can be implemented as unitary transformations, or partial isometries if gauge symmetries are involved. This characterization permits to search systematically for dualities and self-dualities in quantum models of arbitrary system size, dimensionality and complexity, and any classical model admitting a transfer matrix representation. Dualities like exact dimensional reduction, emergent, and gauge-reducing dualities that solve gauge constraints can be easily understood in terms of mappings of bond algebras. As a new example, we show that the (\mathbb{Z}_2) Higgs model is dual to the extended toric code model {\it in any number of dimensions}. Non-local dual variables and Jordan-Wigner dictionaries are derived from the local mappings of bond algebras. Our bond-algebraic approach goes beyond the standard approach to classical dualities, and could help resolve the long standing problem of obtaining duality transformations for lattice non-Abelian models. As an illustration, we present new dualities in any spatial dimension for the quantum Heisenberg model. Finally, we discuss various applications including location of phase boundaries, spectral behavior and, notably, we show how bond-algebraic dualities help constrain and realize fermionization in an arbitrary number of spatial dimensions.Comment: 131 pages, 22 figures. Submitted to Advances in Physics. Second version including a new section on the eight-vertex model and the correction of several typo
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