47 research outputs found

    Comparing the Degree of Red Cell Haemolysis, Including Blood Volume Yielded, Between Two Techniques of Extracting Blood from Surgical Swabs

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    https://drive.google.com/file/d/1VQXUutGEMfe1pQpxmdmotnkaIxj5HKxx/view?usp=sharinghttps://drive.google.com/drive/folders/1up7ZcUN1_Viu7rPEVdBWBTHPSBeN5-D3?usp=sharinghttps://drive.google.com/drive/folders/1_Md3gSUahN0M1xQlp0E5x_-Q7sntAAqE?usp=sharin

    First principles calculation of uniaxial magnetic anisotropy and magnetostriction in strained CMR films

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    We performed first - principles relativistic full-potential linearized augmented plane wave calculations for strained tetragonal ferromagnetic La(Ba)MnO3_3 with an assumed experimental structure of thin strained tetragonal La0.67_{0.67}Ca0.33_{0.33}MnO3_3 (LCMO) films grown on SrTiO3_3[001] and LaAlO3_3[001] substrates. The calculated uniaxial magnetic anisotropy energy (MAE) values, are in good quantitative agreement with experiment for LCMO films on SrTiO3_3 substrate. We also analyze the applicability of linear magnetoelastic theory for describing the stain dependence of MAE, and estimate magnetostriction coefficient λ001\lambda_{001}.Comment: Talk given at APS99 Meeting, Atlanta, 199

    Near-Surface Interface Detection for Coal Mining Applications Using Bispectral Features and GPR

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    The use of ground penetrating radar (GPR) for detecting the presence of near-surface interfaces is a scenario of special interest to the underground coal mining industry. The problem is difficult to solve in practice because the radar echo from the near-surface interface is often dominated by unwanted components such as antenna crosstalk and ringing, ground-bounce effects, clutter, and severe attenuation. These nuisance components are also highly sensitive to subtle variations in ground conditions, rendering the application of standard signal pre-processing techniques such as background subtraction largely ineffective in the unsupervised case. As a solution to this detection problem, we develop a novel pattern recognition-based algorithm which utilizes a neural network to classify features derived from the bispectrum of 1D early time radar data. The binary classifier is used to decide between two key cases, namely whether an interface is within, for example, 5 cm of the surface or not. This go/no-go detection capability is highly valuable for underground coal mining operations, such as longwall mining, where the need to leave a remnant coal section is essential for geological stability. The classifier was trained and tested using real GPR data with ground truth measurements. The real data was acquired from a testbed with coal-clay, coal-shale and shale-clay interfaces, which represents a test mine site. We show that, unlike traditional second order correlation based methods such as matched filtering which can fail even in known conditions, the new method reliably allows the detection of interfaces using GPR to be applied in the near-surface region. In this work, we are not addressing the problem of depth estimation, rather confining ourselves to detecting an interface within a particular depth range

    An assessment of the potential economic impacts of the invasive polyphagous shot hole borer (Coleoptera: Curculionidae) in South Africa

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    Studies addressing the economic impacts of invasive alien species are biased towards ex-post assessments of the costs and benefits of control options, but ex-ante assessments are also required to deal with potentially damaging invaders. The polyphagous shot hole borer Euwallacea fornicatus (Coleoptera: Curculionidae) is a recent and potentially damaging introduction to South Africa. We assessed the potential impact of this beetle by working across economic and biological disciplines and developing a simulation model that included dynamic mutualistic relations between the beetle and its symbiotic fungus. We modeled the potential growth in beetle populations and their effect on the net present cost of damage to natural forests, urban trees, commercial forestry, and the avocado industry over 10 yr. We modeled high, baseline, and low scenarios using discount rates of 8, 6, and 4%, and a plausible range of costs and mortality rates. Models predicted steady growth in the beetle and fungus populations, leading to average declines in tree populations of between 3.5 and 15.5% over 10 yr. The predicted net present cost was 18.45 billion international dollars (Int. ),orabout0.66), or about 0.66% of the country’s GDP for our baseline scenario (2.7 billion to $164 billion for low and high scenarios). Most of the costs are for the removal of urban trees that die as a result of the beetle and its fungal symbiont, as has been found in other regions. We conclude that an ex-ante economic assessment system dynamics model can be useful for informing national strategies on invasive alien species management.The Department of Science and Innovation-National Research Foundation (DSI-NRF) Centre of Excellence for Invasion Biology and the Centre for Biological Control at Rhodes University as well as the Oppenheimer Memorial Trust and the Millennium Trust.https://academic.oup.com/jeehj2023BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

    Adapted full-face snorkel masks as an alternative for COVID-19 personal protection during aerosol generating procedures in South Africa

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    INTRODUCTION : SARS-CoV-2 has resulted in increased worldwide demand for personal protective equipment (PPE). With pressure from ongoing epidemic and endemic episodes, we assessed an adapted snorkel mask that provides full-face protection for healthcare workers (HCWs), particularly during aerosol-generating procedures. These masks have a custom-made adaptor which allows the fitment of standard medical respiratory filters. The aim of this study was to evaluate the fit, seal and clinical usability of these masks. METHODS : This multicentre, non-blinded in-situ simulation study recruited fifty-two HCWs to don and doff the adapted snorkel mask. Negative pressure seal checks and a qualitative fit test were performed. The HCWs completed intubation and extubation of a manikin in a university skills training laboratory, followed by a webbased questionnaire on the clinical usability of the masks. RESULTS : Whilst fit and usability data were generally satisfactory, two of the 52 participants (3.8%) felt that the mask did not span the correct distance from the nose to the chin, and 3 of 34 participants (8.8%) who underwent qualitative testing with a Bitrex test failed. The majority of users reported no fogging, humidity or irritation. It was reportedly easy to speak while wearing the mask, although some participants perceived that they were not always understood. Twenty-one participants (40%) experienced a subjective physiological effect from wearing the mask; most commonly a sensation of shortness of breath. DISCUSSION : A fit-tested modified full-face snorkel mask may offer benefit as a substitute for N95 respirators and face shields. It is, however, important to properly select the correct mask based on size, fit testing, quality of the three-dimensional (3D) printed parts and respiratory filter to be used. Additionally, HCWs should be trained in the use of the mask, and each mask should be used by a single HCW and not shared.APPENDIX A. SUPPLEMENTARY DATA. APPENDIX B. Fig. B1: A. The SEAC Libera full face snorkel mask, and B. The Mares Sea Vu Care full face snorkel masks, used in this study. Fig. B2: Adapter for A: SEAC Libera Med+ mask and B: Mares Sea Vu Care. Fig. B3: Clear-Guard 3 Breathing Filter used in this study. APPENDIX C. Intubation and extubation checklists. APPENDIX D. Comparison of the different snorkel masks. APPENDIX E. Google form to determine clinical usability of the full-face snorkel mask.The Faculty of Health Science, University of Pretoria who provided financial assistance through the Leeds University COVID-19 funds.https://www.elsevier.com/locate/afjemam2022AnaesthesiologyInternal Medicin

    The first two centuries of colonial agriculture in the cape colony: A historiographical review∗

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    ENIGMA and global neuroscience: A decade of large-scale studies of the brain in health and disease across more than 40 countries

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    This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of "big data" (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA's activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors

    The epitaxy of gold

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    The MeerKAT Galaxy Cluster Legacy Survey: I. Survey overview and highlights

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    Please abstract in the article.The South African Radio Astronomy Observatory (SARAO), the National Research Foundation (NRF), the National Radio Astronomy Observatory, US National Science Foundation, the South African Research Chairs Initiative of the DSI/NRF, the SARAO HCD programme, the South African Research Chairs Initiative of the Department of Science and Innovation.http://www.aanda.orghj2022Physic

    The interpretation of the revelatory events in John 17:24-26 : an exegetical exercise

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    John 1:18 spells out the purpose of the incarnation of the Son of God (to make God known - ejxhgei`sqai ) and functions as the transition from the prologue to the rest of the Fourth Gospel. With verse 18 the Evangelist signals that the revelation of God, through his Son, is intrinsic to the composition of the Fourth Gospel. This is particularly evident in chapter 17(:24-26), where we find an explicit reference to a triadic revelation: revelation during Jesus' ministry, post-resurrection revelation, and future eschatological revelation. The aim of the investigation of Jn 17:24-26 is to gain an understanding of what Jesus (and the Fourth Evangelist) tries to emphasize and to communicate to his disciples (and the readers) concerning his revelatory (-salvific) mission. In the exposition of this text it is pointed out what each phase in the triadic revelation comprises, and how these phases of revelation link to one another.http://explore.up.ac.za/record=b152516
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