123 research outputs found

    Assessing a portable, real-time display handheld meter with UV-A and UV-B sensors for potential application in personal sun exposure studies

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    BACKGROUND : Observing accurate real-time measurements of solar ultraviolet radiation (UVR) levels is important since personal excess sun exposure is associated with skin cancers. Handheld measurement devices may be helpful but their accuracy is unknown. We compare a portable, science-grade solar UVR monitoring device against two fixed, science-grade solar UVR instruments. METHODS : Instruments were (1) a fixed Solar Light 501 UV-B biometer to measure UV-B; (2) a fixed Kipp and Zonen radiometer used to measure UV-A and UV-B; and (3) Goldilux ultraviolet probes which are commercially available portable devices. Two different probes were used, one measured UV-A and the other UV-B radiation. The Goldilux probes were levelled and secured next to the UV-B biometer. Between 10:00 and 14:40 UTC+2, the UV-B biometer was set to record at 10-minute intervals and measurements by the Goldilux probes were manually taken simultaneously. Results were compared for all data and by solar zenith angle (SZA) ranges. RESULTS : The Goldilux UV-B probe measured UV-B relatively well in its diurnal pattern, however, its readings were ~77% higher than those made by the UV-B biometer. While UV-A measurements from the Goldilux UV-A probe and those from the radiometer were in relatively good agreement in pattern, the radiometer read ~47% higher than the Goldilux UV-A probe. UV-B data from Goldilux UV-B probe had a moderately strong correlation with UV-B biometer data for small SZAs; conversely, for UV-A, the Goldilux UV-A probe had a strong correlation with the UV-A radiometer data for large SZAs. CONCLUSION : Handheld devices may be useful to provide real-time readings of solar UVR patterns, however, to achieve synchronicity in the magnitude of readings to those made by science-grade fixed instruments, devices may need to be used during certain times of the day and in clear-sky conditions which may not be practical in personal exposure studies.Dr Wright receives funding support from the South African Medical Research Council and the National Research Foundation of South Africa.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1600-08462019-11-01hj2019Geography, Geoinformatics and Meteorolog

    A note on Morita equivalence to graph inverse semigroups

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    We characterize the inverse semigroups that are Morita equivalent to graph inverse semigroups. We also consider a generalization to inverse semigroups associated with left cancellative categories.Comment: 10 pages, fixed an error in the proof of the main theore

    The epidemiology of skin cancer and public health strategies for its prevention in Southern Africa

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    Skin cancer is a non-communicable disease that has been underexplored in Africa, including Southern Africa. Exposure to solar ultraviolet radiation (UVR) is an important, potentially modifiable risk factor for skin cancer. The countries which comprise Southern Africa are Botswana, Lesotho, Namibia, South Africa, and Swaziland. They di er in population size and composition and experience di erent levels of solar UVR. Here, the epidemiology and prevalence of skin cancer in Southern African countries are outlined. Information is provided on skin cancer prevention campaigns in these countries, and evidence sought to support recommendations for skin cancer prevention, especially for people with fair skin, or oculocutaneous albinism or HIV-AIDS who are at the greatest risk. Consideration is given to the possible impacts of climate change on skin cancer in Southern Africa and the need for adaptation and human behavioural change is emphasized.Table S1: Absence (x) or presence (X) of evidence of online skin cancer prevention campaigns (any focus—could be in relation to albinism) in English by country in Africa. Websites valid as at the 17 December 2019.The South African Medical Research Council and the National Research Foundation (South Africa).http://www.mdpi.com/journal/ijerpham2020Geography, Geoinformatics and Meteorolog

    A molecular survey across Madagascar does not yield positive records of the amphibian chytrid fungus Batrachochytrium dendrobatidis.

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    Madagascar harbors a rich and diverse amphibian fauna, with over 280 nominal species of native frogs, all of which are endemic to the island. Although many species are threatened predominantly by habitat destruction, so far this fauna has not experienced any enigmatic declines as amphibians have in other parts of the globe. The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), associated with mass amphibian die offs in Europe, the Americas and Australia has so far not been detected in Madagascar, but surveys so far were based mainly on histological examination of frog samples, with molecular data from only a single site. Here, we present results from a molecular screening of altogether 300 frog specimens belonging to 53 species in 13 genera, from 12 sites throughout Madagascar spanning all of Madagascar`s major bioclimatic regions and an array of different elevations from 20 to 2400 m above sea level. All samples were analyzed using a standard quantitative real time polymerase chain reaction (qPCR) assay and yielded only negative results, suggesting the widespread absence or very localized and low prevalence of the amphibian chytrid fungus across Madagascar during the sampling years 2006 and 2007.This research was supported by Conservation International, by the Spanish Ministry of Science, by the Volkswagen Foundation, and by The US National Science Foundation (EF-0723563 and 1120283)Peer Reviewe

    A systematic literature review of the career choice of helping professionals who have experienced cumulative harm as a result of adverse childhood experiences

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    The pervasive effects of cumulative harm resulting from adverse childhood experiences influence all aspects of an individual’s life course. Research highlights a relationship between early trauma and career choice; however, there is a dearth of research pertaining specifically to cumulative harm and the influence on career choice in the helping professions. A systematic literature review was conducted to explore the associations of cumulative harm and childhood trauma on career decision making in people in the helping professions. A search was conducted across databases between February 1990 and February 2019 relevant to searches combining three areas of interest: (a) 'childhood trauma', (b) 'career choice', and (c) 'helping professionals'. Database searches and further manual searches yielded a total of 208 articles, and 28 studies satisfied all inclusion criteria. Only studies that were peer-reviewed and published between February 1990 and February 2019 were included. The evidence from the review indicated that family of origin dysfunction, parentification, individual characteristics, and traits developed through adversity, and experiential motivations were associated with the career choice in the helping professions. Further research is required to explore different professional cohorts and the utility of life themes as both a source of data for research and reflexive practice in helping professionals

    Total and tropospheric ozone changes: observations and numerical modelling

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    A survey has been made of total and tropospheric ozone dynamics in the context of its impacts on climate, human health and ecosystems. Observation data on total ozone content (TOZ) in the atmosphere and relevant numerical modelling results have been discussed as well as similar information for tropospheric ozone, whose formation and changes are being determined by quite different causes. A necessity has been emphasized to get more adequate global observational data on TOZ and tropospheric ozone (this is especially important in the latter case, because information on tropospheric ozone is far from being complete). Unsolved problems relevant to both total and tropospheric ozone have been briefly considered

    Exploring Meteorological Conditions and Human Health Impacts during Two Dust Storm Events in Northern Cape Province, South Africa: Findings and Lessons Learnt

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    Dust storms are meteorological hazards associated with several adverse health impacts including eye irritations, respiratory and cardiovascular disorders, and vehicular road accidents due to poor visibility. This study investigated relations between admissions from a large, public hospital that serves people living in Northern Cape and Free State provinces, South Africa during 2011 to 2017, and meteorological variables (temperature and air quality) during two dust storms, one in October 2014 (spring) and the second in January 2016 (summer), identified from the media as no repository of such events exists for South Africa. Distributed nonlinear lag analysis and wavelet transform analysis were applied to explore the relationships between hospital admissions for respiratory and cardiovascular diseases, eye irritation, and motor vehicle accidents; maximum temperature, and two air quality ‘proxy measures,’ aerosol optical depth and Ångström exponent, were used as ground-based air quality data were unavailable. Eye irritation was the most common dust-related hospital admission after both dust storm events. No statistically significant changes in admissions of interest occurred at the time of the two dust storm events, using either of the statistical methods. Several lessons were learnt. For this type of study, ground-based air quality and local wind data are required; alternative statistical methods of analysis should be considered; and a central dust storm repository would help analyze more than two events. Future studies in South Africa are needed to develop a baseline for comparison of future dust storm events and their impacts on human health

    Dwelling characteristics influence indoor temperature and may pose health threats in LMICs

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    BACKGROUND: Shelter and safe housing is a basic human need that brings about a sense of ownership, selfsufficiency, and citizenship. Millions of people around the world live in inadequate dwellings in unhealthy areas, such as urban slums. These dwellings may experience indoor temperatures that impact inhabitants’ health. Indoor dwelling temperatures vary depending on many factors including geographic location, such as inland versus coastal. In an era of climate change, understanding how dwelling characteristics influence indoor temperature is important, especially in low- and middle-income countries, to protect health. OBJECTIVE: To assess indoor temperature in low-cost dwellings located in a coastal setting in relation to dwelling characteristics. METHODS: Indoor temperature and relative humidity loggers were installed from 1 June 2017 to 15 May 2018 in 50 dwellings in two settlements in a coastal town on the east coast of South Africa. Ambient outdoor temperature data were obtained from the national weather service, indoor temperature data were converted into apparent temperature, and heat index calculations were made to consider possible heat-health risks. A household questionnaire and dwelling observation assessment were administered. A mixed-effects linear regression model was constructed to consider the impact of dwelling characteristics on indoor apparent temperature. FINDINGS: Among 17 dwellings with all data sets, indoor temperatures were consistently higher than, and well correlated (r = 0.92) with outdoor temperatures. Average differences in indoor and outdoor temperatures were about 4°C, with statistically significant differences in percentage difference of indoor/outdoor between seasons (p < 0.001). Heat indices for indoor temperatures were exceeded mostly in summer, thereby posing possible health risks. Dwellings with cement floors were statistically significantly cooler than any other floor type across all seasons. CONCLUSIONS: Low-cost dwellings experienced temperatures indoors higher than outdoor temperatures in part due to floor type. These results help inform interventions that consider housing and human health (n = 289).The South African Medical Research Council (SAMRC), the Nelson Mandela University (NMU) and the National Research Foundation (South Africa).https://www.annalsofglobalhealth.orgpm2020Geography, Geoinformatics and Meteorolog

    Characterization of human behavior in records of personal solar ultraviolet exposure records: poster

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    Exposure to solar ultraviolet radiation (UVR) has health benefits such as vitamin D production but excess exposure can lead to sunburn, cataracts and skin cancer Risk factors associated with sun exposure can be limited by using sun protection measures Personal sun exposure differs from ambient UVR as it is influenced by behavior, movement and bodily location which are an indication of individual exposure behavio
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