627 research outputs found

    Ozone and ultraviolet radiation

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    Imagine if the earth’s protective atmosphere did not exist and the earth was subjected to the harmful ultraviolet energy from the sun. Life as we know would not exist. Changes in the earth’s layer of atmospheric ozone may be occurring as a result of human activities. This is generating concerns in the community about increases in terrestrial ultraviolet radiation and the associated adverse effects on humans, plants and animals

    Measurement of reflected, total and diffuse solar erythemal ultraviolet radiation

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    [Abstract]: An experimental program was devised by the authors to firstly, provide students with practical ‘hands-on’ experience of concepts of physics, and secondly, increase awareness of the dangers of UV radiation by a series of scientific measurements on UV irradiance levels. A group of grade 10 students undertook the experiment and sample results are presented

    Student Demographics with Changing Admission Criteria: Is Nursing Diversity at Risk?

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    Schools of nursing are challenged with choosing from an increasing number of applicants and the need to prepare as many successful nurses as possible to meet the nursing shortage. Strategies have included increasing student enrollment, utilizing accelerated programs, and changing admission criteria. This study describes the demographic characteristics of three classes of nursing students admitted under different criteria to the same nursing school. The value of maintaining a high level of ethnic diversity is guided by Leininger\u27s theory of cultural care diversity and universality. Although changes occurred in the demographic constitution of each nursing class, ethnic diversity was maintained as admission criteria were made more stringent

    Personal solar UV exposure measurements employing modified polysulphone with an extended dynamic range

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    Polysulphone dosimeters using a simple to use filter have been developed and tested to provide an extended dynamic measurement range of personal solar UV exposures over an extended period (3 to 6 days). At a Southern Hemisphere subtropical site (27.68S, 151.98E), the dynamic range of the filtered polysulphone allowed measurements of erythemal exposures to approximately 100 minimum erythemal dose (MED) for a change in optical absorbance at 330 nm (DA330) of 0.35. In comparison, unfiltered polysulphone dosimeters were exposed to approximately 8 MED for the same DA330. The error associated with the use of the filtered polysulphone dosimeters is of the order of 615%, compared with 610% of the unfiltered variety. The developed filtered polysulphone dosimeter system allowed the measurement of erythemal UV exposures over 3 to 6 days at a subtropical site without the need to replace the dosimeters because of saturation. The results show that longer-term measurement programs of personal solar UV have been made more feasible with the use of these polysulphone dosimeters with an extended dynamic range compared with unfiltered polysulphone dosimeters

    Why do UV levels vary?

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    Have you ever suffered the excrutiating pain and discomfort of a severe sunburn followed by the unsightly peeling of the skin? Have you ever wondered why you may receive a sunburn even on a partially cloudy day? There are a number of factors that influence the amount of solar ultraviolet radiation reaching the earth’s surface

    Human UVA exposures estimated from ambient UVA measurements

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    [Abstract]: The methods presented in this paper allow for the estimation of human UVA exposure using measured UVA irradiance values. Using measured broadband UVA irradiances over the period of a year, it was estimated that for humans in an upright posture and not moving the head with respect to the body, the nose received 26.5% of the available ambient UVA radiation, whilst the shoulders and vertex of the head received 81% and 100% respectively of the available ambient UVA radiation. Measurement of the exposure ratios for a series of solar zenith angles between 90o and 0o will allow extension of this technique to other latitudes

    Serum vitamin D decreases during chemotherapy: an Australian prospective cohort study

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    Background and Objectives: Vitamin D plays an important role in bone and muscle function, and cell prolifera-tion. The impact of chemotherapy and associated behavioural changes such as fatigue and sun avoidance on vit-amin D (25(OH) D) is unknown. This study aims to evaluate variations in serum vitamin D during chemotherapy and the predictive value of latitude, season and pre-existing vitamin D deficiency. Methods and Study Design: A 12-week prospective cohort study was conducted in chemotherapy-naïve patients in two Australian locations with different sun exposure. Vitamin D deficiency was defined as ≤ 25 nmol/L and insufficiency 26-50 nmol/L 25(OH) D. Demographics, chemotherapy regimen, nutritional status, sun exposure, geographic location, and sea-son were collected at baseline, 6 and 12 weeks after commencing chemotherapy. Results: Eighty-five patients (μ55.3±13.4 years of age; 49% female) were recruited, 96% Caucasian. Fifty-four patients were treated with cura-tive intent (mostly for breast [n=29] or colorectal [n=12] cancers). At baseline, 10 patients were vitamin D defi-cient and 33 were insufficient. Mean serum 25(OH) D (nmol/L) was higher at latitude -27.5o (Brisbane) than lati-tude -34.9o (Adelaide) (μ61.9±22.1 vs μ42.2±19.2, p < 0.001) and varied according to season (spring: μ46.9±20.3, summer: μ50.8±18.2, autumn: μ76.4±25.2, winter: μ36.5±15.7, p < 0.001). Serum 25(OH) D decreased with chemotherapy (baseline: μ49.2±22.3, 6-weeks: μ40.9±19.0, 12-weeks: μ45.9±19.7, p=0.05), with a significant and more rapid decline in winter and autumn (p=0.03). Conclusions: Chemotherapy is associated with a decrease in serum vitamin D, particularly during winter and autumn. Investigations into the underlying mechanism and as-sociated potential outcomes with this decrease requires further investigation

    Parametric human modelling to determine body surface area covered by sun-protective clothing

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    Solar ultraviolet radiation (UVR) is the main environmental risk-factor for cancer of the skin. Sun-protective clothing provides a physical barrier that reduces the UVR dose reaching the skin and European and Australian standards for sun-protective clothing set minimum clothing coverage requirements. Body Surface Area Coverage by clothing (BSAC) is calculated by means of indirect or direct methods, which are laborious and do not support computer-based apparel design. To support the sun-safe specification and design of garments, parametric digital human models and protective clothing mesh covering the minimum Body Surface Area specified in AS/NZS 4399:2017, were created making use of MakeHuman v1.1.1 and Blender software. The Whole Body Surface Area (WBSA) and the BSAC were calculated employing code developed in Blender. Thus, different groups of subjects were analysed to explore BSAC. The method assists in the evaluation of exposed body areas in a wider spectrum of different occupations. Practitioner summary: Sun-protective clothing provides a physical barrier that reduces the UVR dose reaching the skin’s surface. Body Surface Area Coverage (BSAC) by clothing is an important determinant of the sun protective capabilities of a garment. In this study, BSAC is calculated using parametric digital human modelling
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