412 research outputs found

    A new approach to evaluate gamma-ray measurements

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    Misunderstandings about the term random samples its implications may easily arise. Conditions under which the phases, obtained from arrival times, do not form a random sample and the dangers involved are discussed. Watson's U sup 2 test for uniformity is recommended for light curves with duty cycles larger than 10%. Under certain conditions, non-parametric density estimation may be used to determine estimates of the true light curve and its parameters

    SARS-CoV-2 infection and pulmonary tuberculosis in children and adolescents: a case-control study

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    Background The Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) pandemic has had an impact on the global tuberculosis (TB) epidemic but evidence on the possible interaction between SARS-CoV-2 and TB, especially in children and adolescents, remains limited. We aimed to evaluate the relationship between previous infection with SARS-CoV-2 and the risk of TB in children and adolescents. Methods An unmatched case-control study was conducted using SARS-CoV-2 unvaccinated children and adolescents recruited into two observational TB studies (Teen TB and Umoya), between November 2020 and November 2021, in Cape Town, South Africa. Sixty-four individuals with pulmonary TB (aged < 20 years) and 99 individuals without pulmonary TB (aged < 20 years) were included. Demographics and clinical data were obtained. Serum samples collected at enrolment underwent quantitative SARS-CoV-2 anti-spike immunoglobulin G (IgG) testing using the Abbott SARS-CoV-2 IgG II Quant assay. Odds ratios (ORs) for TB were estimated using unconditional logistic regression. Results There was no statistically significant difference in the odds of having pulmonary TB between those who were SARS-CoV-2 IgG seropositive and those who were seronegative (adjusted OR 0.51; 95% CI: 0.23–1.11; n = 163; p = 0.09). Of those with positive SARS-CoV-2 serology indicating prior infection, baseline IgG titres were higher in individuals with TB compared to those without TB (p = 0.04) and individuals with IgG titres in the highest tertile were more likely to have pulmonary TB compared to those with IgG levels in the lowest tertile (OR: 4.00; 95%CI: 1.13– 14.21; p = 0.03). Conclusions Our study did not find convincing evidence that SARS-CoV-2 seropositivity was associated with subsequent pulmonary TB disease; however, the association between magnitude of SARS-CoV-2 IgG response and pulmonary TB warrants further investigation. Future prospective studies, evaluating the effects of sex, age and puberty on host immune responses to M. tuberculosis and SARS-CoV-2, will also provide more clarity on the interplay between these two infections

    Extending the geographical distribution of Side-striped Jackal, Lupulella adusta (Sundevall, 1847) (Carnivora, Canidae), in South Africa

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    Side-striped Jackal, Lupulella adusta (Sundevall, 1847), occurs in a vast area within sub-Saharan Africa. In South Africa, the current geographical distribution is limited to eastern coastal regions. Recent sightings from north-central areas of the country suggest a wider geographical distribution. Here we report on 5,130 confirmed, repeated detections of Side-striped Jackal. Of these, 3,625 captures were from 471 new locations not previously recorded in the scientific literature, thereby expanding their current geographical distribution. These new records were captured in 33 vegetation types, including the forest and grassland biomes where they are not commonly detected

    Hearing aid consumer reviews: a linguistic analysis in relation to benefit and satisfaction ratings

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    PURPOSE : Online reviews have been used by hearing aid owners to share their experiences and to provide suggestions to potential hearing aid buyers, although they have not been systematically examined. The study was aimed at examining the hearing aid consumer reviews using automated linguistic analysis, and how the linguistic variables relate to self-reported hearing aid benefit and satisfaction ratings. METHOD : The study used a cross-sectional design. One thousand three hundred seventy-eight consumer hearing aid reviews (i.e., text response to open-ended question), self-reported benefit and satisfaction ratings on hearing aids in a 5-point scale with meta-data (e.g., hearing aid brand, technology level) extracted from the Hearing Tracker website were analyzed using automated text analysis method known as the Linguistic Inquiry and Word Count. RESULTS : Self-reported hearing aid benefit and satisfaction ratings were high (i.e., mean rating of 4.04 in a 5-point scale). Examining the association between overall rating and the key linguistic variables point to two broad findings. First, the more people were personally, socially, and emotionally engaged with the hearing device experience, the higher they rated their hearing device(s). Second, a minimal occurrence of clinic-visit language dimensions points to factors that likely affect benefit and satisfaction ratings. For example, if people mention paying too much money (money), their overall ratings are generally lower. Conversely, if people write about their health or home, the ratings were higher. There was no significant difference in linguistic analysis across different hearing aid brands and technology levels. CONCLUSIONS : Hearing aid consumers are generally satisfied with their hearing device(s), and their online reviews contain information about social/emotional dimensions as well as clinic-visit related aspects that have bearing toward hearing aid benefit and satisfaction ratings. These results suggest that the natural language used by consumers provide insights on their perceived benefit/satisfaction from their hearing device.https://pubs.asha.org/journal/ajahj2022Speech-Language Pathology and Audiolog

    On the multiple Borsuk numbers of sets

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    The Borsuk number of a set S of diameter d >0 in Euclidean n-space is the smallest value of m such that S can be partitioned into m sets of diameters less than d. Our aim is to generalize this notion in the following way: The k-fold Borsuk number of such a set S is the smallest value of m such that there is a k-fold cover of S with m sets of diameters less than d. In this paper we characterize the k-fold Borsuk numbers of sets in the Euclidean plane, give bounds for those of centrally symmetric sets, smooth bodies and convex bodies of constant width, and examine them for finite point sets in the Euclidean 3-space.Comment: 16 pages, 3 figure

    Hearing aid acquisition and ownership : what can we learn from online consumer reviews?

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    OBJECTIVE : To explore the publicised opinions of consumers actively participating in online hearing aid reviews. DESIGN : A retrospective design examining data generated from an online consumer review website (www.HearingTracker.com). Qualitative data (open text responses) were analysed using the open source automated topic modelling software IRaMuTeQ (http://www.iramuteq.org/) to identify themes. Outputs were compared with quantitative data from the consumer reviews (short response questions exploring hearing aid performance and benefit, and some meta-data such as hearing aid brand and years of hearing aid ownership). STUDY SAMPLE : 1378 online consumer hearing aid reviews. RESULTS : Six clusters within two domains were identified. The domain Device Acquisition included three clusters: Finding the right provider, device and price-point; Selecting a hearing aid to suit the hearing loss; Attaining physical fit and device management skills. The domain Device Use included three clusters: Smartphone streaming to hearing aids; Hearing aid adjustment using smartphone; and Hearing in noise. CONCLUSIONS : Although online hearing aid consumers indicate positive performance on multiple-choice questions relating to hearing aid performance and benefit, their online reviews describe a number of barriers limiting their success. Hearing healthcare clinicians must employ a personalised approach to audiological rehabilitation to ensure individual clients’ needs are met.https://www.tandfonline.com/loi/iija20hj2022Speech-Language Pathology and Audiolog

    Outbreak of Marburg hemorrhagic fever among miners in Kamwenge and Ibanda Districts, Uganda, 2007

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    Marburg hemorrhagic fever was detected among 4 miners in Ibanda District, Uganda, from June through September, 2007. Infection was likely acquired through exposure to bats or bat secretions in a mine in Kamwenge District, Uganda, and possibly human-to-human transmission between some patients. We describe the epidemiologic investigation and the health education response

    Long-term evidence for ecological intensification as a pathway to sustainable agriculture

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    Ecological intensification (EI) could help return agriculture into a ‘safe operating space’ for humanity. Using a novel application of meta-analysis to data from 30 long-term experiments from Europe and Africa (comprising 25,565 yield records), we investigated how field-scale EI practices interact with each other, and with N fertilizer and tillage, in their effects on long-term crop yields. Here we confirmed that EI practices (specifically, increasing crop diversity and adding fertility crops and organic matter) have generally positive effects on the yield of staple crops. However, we show that EI practices have a largely substitutive interaction with N fertilizer, so that EI practices substantially increase yield at low N fertilizer doses but have minimal or no effect on yield at high N fertilizer doses. EI practices had comparable effects across different tillage intensities, and reducing tillage did not strongly affect yields

    MassTag polymerase chain reaction for differential diagnosis of viral hemorrhagic fevers

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    Viral hemorrhagic fevers are associated with high rates of illness and death. Although therapeutic options are limited, early differential diagnosis has implications for containment and may aid in clinical management. We describe a diagnostic system for rapid, multiplex polymerase chain reaction identification of 10 different causes of viral hemorrhagic fevers

    Propagation of Respiratory Aerosols by the Vuvuzela

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    Vuvuzelas, the plastic blowing horns used by sports fans, recently achieved international recognition during the FIFA World Cup soccer tournament in South Africa. We hypothesised that vuvuzelas might facilitate the generation and dissemination of respiratory aerosols. To investigate the quantity and size of aerosols emitted when the instrument is played, eight healthy volunteers were asked to blow a vuvuzela. For each individual the concentration of particles in expelled air was measured using a six channel laser particle counter and the duration of blowing and velocity of air leaving the vuvuzela were recorded. To allow comparison with other activities undertaken at sports events each individual was also asked to shout and the measurements were repeated while using a paper cone to confine the exhaled air. Triplicate measurements were taken for each individual. The mean peak particle counts were 658×103 per litre for the vuvuzela and 3.7×103 per litre for shouting, representing a mean log10 difference of 2.20 (95% CI: 2.03,2.36; p<0.001). The majority (>97%) of particles captured from either the vuvuzela or shouting were between 0.5 and 5 microns in diameter. Mean peak airflows recorded for the vuvuzela and shouting were 6.1 and 1.8 litres per second respectively. We conclude that plastic blowing horns (vuvuzelas) have the capacity to propel extremely large numbers of aerosols into the atmosphere of a size able to penetrate the lower lung. Some respiratory pathogens are spread via contaminated aerosols emitted by infected persons. Further investigation is required to assess the potential of the vuvuzela to contribute to the transmission of aerosol borne diseases. We recommend, as a precautionary measure, that people with respiratory infections should be advised not to blow their vuvuzela in enclosed spaces and where there is a risk of infecting others
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