WorldWideScience

Sample records for artificial ultraviolet radiation

  1. Harmful effects of ultraviolet radiation

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Tanning for cosmetic purposes by sunbathing or by using artificial tanning devices is widespread. The hazards associated with exposure to ultraviolet radiation are of concern to the medical profession. Depending on the amount and form of the radiation, as well as on the skin type of the individual exposed, ultraviolet radiation causes erythema, sunburn, photodamage (photoaging), photocarcinogenesis, damage to the eyes, alteration of the immune system of the skin, and chemical hypersensitivity. Skin cancers most commonly produced by ultraviolet radiation are basal and squamous cell carcinomas. There also is much circumstantial evidence that the increase in the incidence of cutaneous malignant melanoma during the past half century is related to increased sun exposure, but this has not been proved. Effective and cosmetically acceptable sunscreen preparations have been developed that can do much to prevent or reduce most harmful effects to ultraviolet radiation if they are applied properly and consistently. Other safety measures include (1) minimizing exposure to ultraviolet radiation, (2) being aware of reflective surfaces while in the sun, (3) wearing protective clothing, (4) avoiding use of artificial tanning devices, and (5) protecting infants and children

  2. Psoriasis and ultraviolet radiation

    International Nuclear Information System (INIS)

    Farber, E.M.; Nall, L.

    1993-01-01

    Prevention and detection screening programs as a public health service in curtailing the ever-increasing incidence of all forms of skin cancer are reviewed. The effect of solar and artificial ultraviolet radiation on the general population and persons with psoriasis is examined. 54 refs

  3. Ultraviolet radiation, sun and tanning salons; Ultrafiolett straaling, sol og solarier

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    The pamphlet gives some information about ultraviolet radiation (UV), UV-sources and health effects, tanning in artificial and natural sun. It also includes some sun protection advice. It is intended mainly for persons inspecting artificial tanning units and for the owners of tanning salons. (Author)

  4. Ultraviolet radiation

    International Nuclear Information System (INIS)

    Hawk, J.

    1986-01-01

    Ultraviolet radiation (UVR) from the sun or artificial sources is reflected or transmitted at the surface of the skin, about 5% of normally incident rays being directly reflected. The transmitted fraction is scattered, photochemically absorbed or dissipated as heat within the skin, or passes from it to contribute to the variable total amount of reflected and transmitted radiation. The UVR absorbers in skin are not definitely known, but DNA is a definite target and probably lipoprotein membranes, RNA, proteins, mucopolysaccharides, elastin and collagen. Photochemical or free radical damage to absorber or nearby organelles leads to pharmacological, ultrastructural, histological and clinical changes. Most frequent DNA damage is pyrimidine dimer formation, apparently inhibiting cell function and replication. This is largely enzymatically repaired in man in the dark by excision repair, post-replication repair and possible other enzymatic mechanisms, and at least in some organisms by light-induced photoreactivation repair. UVR exposure causes well recognized acute and chronic clinical syndromes in man. These are discussed in this paper

  5. Cosmetic and medical applications of ultraviolet radiation

    International Nuclear Information System (INIS)

    Diffey, B.L.

    1987-01-01

    The social desirability of a tanned skin is apparent and many people associate a bronzed body with good health and a sense of well-being. In Northern Europe and America the lack of long periods of sunshine has led to the establishment of the suntanning industry where artificial sources of ultraviolet radiation emitting almost entirely in the UV-A region supplement sunlight exposure

  6. Occupational applications of ultraviolet radiation

    International Nuclear Information System (INIS)

    Eriksen, P.

    1987-01-01

    A large population of workers are exposed to ultraviolet radiation in various occupational environments which often necessitates protection. Since ultraviolet radiation may create other environmental problems an occupational hazard- and protection evaluation can be complicated. Threshold Limit Values adopted by the American Conference of Governmental Industrial Hygienists (ACGIH) on ultraviolet radiation are used in most countries as guidelines for risk assessment and control measures. This review addresses the levels of ultraviolet radiation met in occupational environments, its measurement and evaluation, and discusses different protection methods. Ultraviolet lasers are beginning to find their way into industrial processes but are still limited in number and they will not be covered here. Emphasis is on broad band incoherent radiation in high risk environments such as welding, and on the evaluation of protective eyewear, see-through curtains and plastics. Other occupational risks associated with the emission of ultraviolet radiation are discussed

  7. Photodetector of ultraviolet radiation

    International Nuclear Information System (INIS)

    Dorogan, V.; Branzari, V.; Vieru, T.; Manole, M.; Canter, V.

    2000-01-01

    The invention relates to photodetectors on base of semiconductors of ultraviolet radiation and may be used in optoelectronic system for determining the intensity and the dose of ultraviolet radiation emitted by the Sun or other sources. Summary of the invention consists in the fact that in the photodetector of ultraviolet radiation the superficial potential barrier is divided into two identical elements, electrically isolated each of the other, one of them being covered with a layer of transparent material for visible and infrared radiation and absorption the ultra violet radiation. The technical result consists in mutual compensation of visible and infrared components of the radiation spectrum

  8. European Code against Cancer 4th edition: Ultraviolet radiation and cancer

    NARCIS (Netherlands)

    R. Greinert (Rüdiger); E. de Vries (Esther); F. Erdmann (Friederike); C. Espina (Carolina); A. Auvinen (Anssi); A. Kesminiene (Ausrele); J. Schüz (Joachim)

    2015-01-01

    textabstractUltraviolet radiation (UVR) is part of the electromagnetic spectrum emitted naturally from the sun or from artificial sources such as tanning devices. Acute skin reactions induced by UVR exposure are erythema (skin reddening), or sunburn, and the acquisition of a suntan triggered by

  9. Systematic for assessment of occupational exposure to ultraviolet radiation; Sistematica para la valoracion de la exposicion laboral frente a radiaciones ultravioletas

    Energy Technology Data Exchange (ETDEWEB)

    Anies Escartin, J.; Perramon Llado, A.

    2011-07-01

    The approval of Royal Decree 486/2010 of 23 April on the protection of health and safety of workers from risks related to exposure to artificial optical radiation, moves to state law a framework of protection against the radiation. This should involve a significant intensification of control at work is conducted in this radiation. Despite the complexity of the issue and limit values ??difficult to apply (for incoherent ultraviolet radiation enters the bounding box up to 5 different values ??may apply), requires a systematic analysis of the problem well done. In this paper we consider the ultraviolet radiation generated by artificial sources.

  10. Establishment of a dosimetry method for the exposure evaluation to the ultraviolet radiation

    International Nuclear Information System (INIS)

    Gronchi, Claudia Carla

    2009-01-01

    A dosimetric method for the exposure evaluation to ultraviolet radiation was established with Al 2 O 3 :C InLight detectors and an OSL microStar reader and software, of Landauer, associated to the techniques of Optically Stimulated Luminescence (OSL) and Photo transferred Optically Stimulated Luminescence (PTOSL). The main phases of this work were: characterization of the Al 2 O 3 :C InLight detectors, without pre-conditioning, exposed to ultraviolet radiation (RUV) of solar and artificial sources, using the OSL technique; characterization of the Al 2 O 3 :C InLight detectors, pre-conditioned, exposed to RUV solar and artificial sources, using the PTOSL technique; practical applications of the Al 2 O 3 :C InLight detectors to the solar and artificial RUV, originating from TIG (Tungsten Inert Gas) and electric welding. The Al 2 O 3 :C InLight detectors presented satisfactory OSL and PTOSL responses in relation to the parameters: wavelength, UV illumination time, irradiance, radiance exposure and angular dependence to the RUV. Those detectors presented maximum OSL and PTOSL stimulation for the wavelength of 330 nm, showing that they are may be useful for UVA radiation detection and dosimetry. (author)

  11. Photodetector of ultra-violet radiation

    International Nuclear Information System (INIS)

    Dorogan, V.; Vieru, T.; Coseac, V.; Chirita, F.

    1999-01-01

    The invention relates to photodetectors on the semiconductors base, in particular, to photodetectors of ultra-violet radiation and can be used in the optoelectronics systems for determining the intensity and dose of ultraviolet radiation emitted by the Sun and other sources. In the structure of the photodetector of ultraviolet radiation with a superficial potential barrier formed of semiconductors A 3 B 5 with the prohibited power width Eg 1 , solid solutions thereof with the prohibited power width Eg 2 and SnO 2 or ITO, in the semiconductors A 3 B 5 at a surface distance less than the absorption length of the visible radiation it is formed an isotype heterojunction between the semiconductors A 3 B 5 and solid solutions thereof with the prohibited power width Eg 2 > Eg 1 . The technical result consists in manufacturing of a photodetector sensitive solely to the ultraviolet radiation

  12. Effectiveness of eye drops protective against ultraviolet radiation.

    Science.gov (United States)

    Daxer, A; Blumthaler, M; Schreder, J; Ettl, A

    1998-01-01

    To test the effectiveness of commercially available ultraviolet (UV)-protective eye drops (8-hydroxy-1-methylchinolinium methylsulphate) which are recommended for protection against both solar and artificial UV radiation. The spectral transmission in the wavelength range from 250 to 500 nm was investigated in 1-nm steps using a high-resolution double monochromator with holographic gratings of 2,400 lines/mm and a 1,000-watt halogen lamp as light source. The transmission spectrum was measured for different values of the layer thickness. The transmission of a liquid layer of about 10 microns, which corresponds to the thickness of the human tear film, shows a cut-off at 290 nm with a transmission of about 25-50% at shorter wavelengths. For wavelengths longer than 290 nm the transmission is higher than 90%. The threshold time ratio for keratitis formation with and without eye drops is above 0.93 considering solar radiation on the earth's surface and above 0.65 considering radiation from arc-welding, respectively. The transmission spectrum of the eye drops under realistic conditions does not show a protective effect against solar UV radiation. However, there exists reduction of UVC radiation in the spectral range typical of artificial UV sources such as arc-welding. We cannot recommend the application of these eye drops as an UV-protective aid against eye damage by solar UV radiation.

  13. Effects of ultraviolet radiation on life-history stages of anurans from Ontario, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Grant, K.P.; Licht, L.E. [York Univ., Toronto, ON (Canada)

    1995-12-01

    The effects of ultraviolet radiation on life-history stages of anurans Bufo americanus, Hyla versicolor, Rana clamitans, and Rana sylvatica were tested. Eggs and larvae were not affected by uv-a at double normal outdoor levels. R. sylvatica embryos exposed to 30 minutes or more of artificially high intensity uv-b levels died. There was no effect on hatching levels for artificially high exposures of uv-b radiation for less than 15 minutes. A greater proportion of abnormal embryos occurred after exposure to 10 or 15 minutes of artificially high intensity treatment at 12 degree Celsius than at 20 degrees Celsius. Only larval R. clamitans showed some level of tolerance of artificially high uv-b levels. Ecologically relevant doses of uv-b had no effect on the developmental period of B. americanus, H. versicolor, and R. sylvatica. Older B. americanus exposed for the same length of time had higher survivorship than younger animals. The role of uv radiation in the presumed decline of amphibian populations was also discussed. 7 tabs., 43 refs.

  14. Ultraviolet-radiation-curable paints

    Energy Technology Data Exchange (ETDEWEB)

    Grosset, A M; Su, W F.A.; Vanderglas, E

    1981-09-30

    In product finishing lines, ultraviolet radiation curing of paints on prefabricated structures could be more energy efficient than curing by natural gas fired ovens, and could eliminate solvent emission. Diffuse ultraviolet light can cure paints on three dimensional metal parts. In the uv curing process, the spectral output of radiation sources must complement the absorption spectra of pigments and photoactive agents. Photosensitive compounds, such as thioxanthones, can photoinitiate unsaturated resins, such as acrylated polyurethanes, by a free radical mechanism. Newly developed cationic photoinitiators, such as sulfonium or iodonium salts (the so-called onium salts) of complex metal halide anions, can be used in polymerization of epoxy paints by ultraviolet light radiation. One-coat enamels, topcoats, and primers have been developed which can be photoinitiated to produce hard, adherent films. This process has been tested in a laboratory scale unit by spray coating these materials on three-dimensional objects and passing them through a tunnel containing uv lamps.

  15. Protection of the skin against occupational and operational ultraviolet and thermal radiation

    International Nuclear Information System (INIS)

    Wiskemann, A.

    1980-01-01

    When irradiation with short wave ultraviolet (UVB) exceed the threshold doses, the eye as well as the skin react with an acute inflammation. After chronic exposure to both radiations the skin is altered as a farmers skin. Thermal visible and infrared radiation may produce a local combustion or a livedo or a general hyperthermia. Many possibilities of an occupational exposition to natural or artificial optical radiation are listed. Until now no exposure limits have been recommended in the Federal Republic of Germany. The biologic effective radiant exposure can be calculated from the spectral distribution of the irradiance. The resulting value should be clearly lower than the threshold doses for the UV-keratoconjunctivitis and for the UV-erythema of the skin. Artificial light sources have to be closed exept the useful radiation beam. When this is impossible and in case of natural radiation, the skin must be shielded by clothing and/or by sunscreen preparations. Photosensitizers as tar products have to be kept away from the skin. (orig.) 891 MG/orig. 892 HIS [de

  16. Ultraviolet radiation, measurements and safety evaluations for radiation protection purposes

    International Nuclear Information System (INIS)

    Witew, B.; Fischer, P.G.

    1983-01-01

    In order to evaluate the effects of ultraviolet radiation, one has to study that photobiologically effective radiation which induces a just measurable threshold reaction. For practical radiation protection, one has to determine the permissible duration of exposure at the end of which the threshold reaction is induced. This time limit is derived by means of spectral measurements and determination of radiation intensity. Detrimental photobiological effects can be avoided, and favourable effects optimized, by observing the time limit. Thus these measurements are used to determine the threshold at which the desired effects of ultraviolet radiation will be accompanied by unwanted effects or damage to persons, as for instance in the use of ultraviolet radiation for operating room sterilization, arc welding work, or cosmetic purposes. (orig.) [de

  17. Toxic effects of ultraviolet radiation on the skin

    International Nuclear Information System (INIS)

    Matsumura, Yasuhiro; Ananthaswamy, Honnavara N.

    2004-01-01

    Ultraviolet (UV) irradiation present in sunlight is an environmental human carcinogen. The toxic effects of UV from natural sunlight and therapeutic artificial lamps are a major concern for human health. The major acute effects of UV irradiation on normal human skin comprise sunburn inflammation (erythema), tanning, and local or systemic immunosuppression. At the molecular level, UV irradiation causes DNA damage such as cyclobutane pyrimidine dimers and (6-4) photoproducts, which are usually repaired by nucleotide excision repair (NER). Chronic exposure to UV irradiation leads to photoaging, immunosuppression, and ultimately photocarcinogenesis. Photocarcinogenesis involves the accumulation of genetic changes, as well as immune system modulation, and ultimately leads to the development of skin cancers. In the clinic, artificial lamps emitting UVB (280-320 nm) and UVA (320-400 nm) radiation in combination with chemical drugs are used in the therapy of many skin diseases including psoriasis and vitiligo. Although such therapy is beneficial, it is accompanied with undesirable side effects. Thus, UV radiation is like two sides of the same coin--on one side, it has detrimental effects, and on the other side, it has beneficial effects

  18. Ultraviolet light - nature's own disinfection process

    Energy Technology Data Exchange (ETDEWEB)

    Munkeberg, T [Thorolf Gregersen a/s, Oslo (Norway)

    1978-05-18

    Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m/sup 3/ /hr, though there is no reason why this should not be increased.

  19. Ultraviolet light - nature's own disinfection process

    International Nuclear Information System (INIS)

    Munkeberg, T.

    1978-01-01

    Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m 3 /hr, though there is no reason why this should not be increased. (JIW)

  20. Impact of ultraviolet radiation on humans

    International Nuclear Information System (INIS)

    Cesarini, J.P.

    2001-01-01

    Solar radiation, including its ultraviolet (UV) components is a key factor in life on Earth. While small quantities of UV are beneficial for people (for example, through the production of vitamin D), the considerable amount to which people sometimes expose themselves may have extremely noxious effects including actinic erythema, sunburn, photo-induced diseases, photo-worsened diseases, actinic ageing and skin cancers. Since the last century, human exposure to UV has increased either by social-behaviour modifications, or by anthropogenic disruption to the environment through, among other things, industrial development. The World Health Organisation's (WHO) INTERSUN programme has several components: action for reconstruction of the ozone layer through, for example, preventing dumping of chlorofluorocarbons; creation and popularisation of a global UV index; prevention campaigns underlining the risks from UV exposure including dissemination of information to daily newspapers. These are all aimed at reducing the amount of UV radiation that people receive. In addition the WHO advises against exposure to UV artificial sources to reduce overall the quantity of UV received. (author)

  1. Impact of ultraviolet radiation on humans

    Energy Technology Data Exchange (ETDEWEB)

    Cesarini, J.P. [Laboratoire de Recherche sur les Tumeurs de la Peau Humaine, INSERM, Paris (France)

    2001-07-01

    Solar radiation, including its ultraviolet (UV) components is a key factor in life on Earth. While small quantities of UV are beneficial for people (for example, through the production of vitamin D), the considerable amount to which people sometimes expose themselves may have extremely noxious effects including actinic erythema, sunburn, photo-induced diseases, photo-worsened diseases, actinic ageing and skin cancers. Since the last century, human exposure to UV has increased either by social-behaviour modifications, or by anthropogenic disruption to the environment through, among other things, industrial development. The World Health Organisation's (WHO) INTERSUN programme has several components: action for reconstruction of the ozone layer through, for example, preventing dumping of chlorofluorocarbons; creation and popularisation of a global UV index; prevention campaigns underlining the risks from UV exposure including dissemination of information to daily newspapers. These are all aimed at reducing the amount of UV radiation that people receive. In addition the WHO advises against exposure to UV artificial sources to reduce overall the quantity of UV received. (author)

  2. Ultraviolet radiation and immunosuppression.

    LENUS (Irish Health Repository)

    Murphy, G M

    2009-11-01

    Ultraviolet (UV) radiation is a complete carcinogen. The effects of UV radiation are mediated via direct damage to cellular DNA in the skin and suppression of image surveillance mechanisms. In the context of organ transplantation, addiction of drugs which suppress the immune system add greatly to the carcinogenicity of UV radiation. This review considers the mechanisms of such effects.

  3. Ultraviolet radiation: the eye

    International Nuclear Information System (INIS)

    Cesarini, J.P.; Sliney, D.H.

    1996-01-01

    Under most conditions, the eye is well adapted to protect itself against ultraviolet radiation encountered in the outdoor environment as a result of the exposure geometry of the sun. Only when snow is on the ground does one experience acute effects of UV sunlight exposure (i.e. snow blindness, or photokeratitis). With regard to artificial sources, there are many occasions where one views bright light sources such as tungsten-halogen lamps, arc lamps and welding arcs. Such viewing is normally only momentary because of the aversion response to bright light and due to discomfort glare. However, such an aversion does not take place for germicidal lamps and other UV lamps which do not contain a strong visible component in their spectrum. The adverse effects from viewing such sources has been studied for decades and during the last two decades guidelines for limiting exposure to protect the eye have been developed. The guidelines were fostered to a large extent by the growing use of lasers and the quickly recognized hazard posed by viewing laser sources. (author)

  4. Exposure of Finnish population to ultraviolet radiation and radiation measurements

    International Nuclear Information System (INIS)

    Hoikkala, M.; Lappalainen, J.; Leszczynski, K.; Paile, W.

    1990-01-01

    This report is based on a survey of the literature on radiation risks involved in sunbathing and the use of solaria. The purpose of the report is to provide background information for the development of regulations on solaria and for informing the public about the risks posed by solaria and the sun. The report gives an overview of the properties and biological effects of ultraviolet radiation. The most important regulations and recommendations issued in various countries are presented. The connection between ultraviolet radiation and the risks of skin cancer is examined both on a general level and in reference to information obtained from the Finnish Cancer Registry. In Finland, the incidence of melanomas nearly tripled between 1960 and 1980. The most important cause is considered to be the population's increased exposure to the su's ultraviolet radiation. There are no reliable data on the connection between the use of solaria and the risks of skin cancer. It is estimated, however, that solaria account for less than 10 per cent of the skin cancer risk of the whole population. There are some difficult physical problems associated with the measurement of ultraviolet radiation emitted by both natural sources and solaria. A preliminary study of these problems has been undertaken by means of a survey of the available literature, supplemented by a review of measurements performed by the Finnish Centre For Radiation and Nuclear Safety. The estimated inaccuracy of the Optronic 742 spectroradiometer used by the Centre in the measurement of ultraviolet radiation emitted by the sun and solaria is about +-14%

  5. Effects of ultraviolet radiation on mole rats kidney: A histopathologic and ultrastructural study

    Directory of Open Access Journals (Sweden)

    Hüseyin Türker

    2014-04-01

    Full Text Available The purpose of this study was to realize the ultrastructural effects of ultraviolet radiation on the kidney tissue cells of mole rats (Spalax leucodon. The mole rats of 180–200 g body weight were divided into the control and radiation-trial groups. The control group was not given any radiation. The other groups were irradiated with artificially produced UVC radiation for 14, 28 and 60 days. The kidney tissue samples were prepared at the end of experiments and analyzed by the light and electron microscope. Several effects were observed in the kidney tissues cells analyzed in accordance with the dose magnitude of radiation. These results clearly show the detrimental effects of UVC radiation on kidney tissue cells in exposure periods dependent on radiation dose and exposure time.

  6. Ultraviolet radiation, cancer of the skin and immunology

    International Nuclear Information System (INIS)

    Suurmond, D.

    1984-01-01

    The effects of near and far ultraviolet radiation on the development of skin neoplasms are reviewed. Especially the role of ultraviolet radiation in immunosuppression is discussed as a possible working mechanism of the tumor promoting the effect of this radiation, beside effects on DNA-repair. (Auth.)

  7. Ultraviolet sterilization

    International Nuclear Information System (INIS)

    Schenck, G.O.

    1987-01-01

    Artificial ultraviolet radiation sources can supply bactericidal energy in such a high dosage that in less than a second a higher degree of disinfection is accomplished than by sun irradiation in hours. Bacteria, viruses, phages, and organic micropollutants can be degraded by photochemical wet combustion down to and below detection limits of organic carbon. There are no known ultraviolet-resistant microorganisms. There are limitations to ultraviolet treatment which can often be overcome by adequate technical measures. Unlike other water purification processes, ultraviolet irradiation only exterminates living organisms. The radiation must be able to penetrate to the objects of the kill; in a dose large enough to kill, and long enough to kill and prevent new growth. Contrary to filters, ultraviolet flow-through reactors do not restrict free flow significantly. In contrast to distillation, ultraviolet irradiation imposes no phase changes to the water. Used as a sequence in ultrapure water systems, maintenance requirements are virtually nonexistent; because of the absence of dissolved and particulate matter in purified water, mechanical cleaning of the photoreactor chambers is not essential. The process is highly economical; energy consumption is low and supervision minimal. 103 refs., 45 figs., 15 tabs

  8. Stratospheric ozone, ultraviolet radiation and climate change

    International Nuclear Information System (INIS)

    Boucher, O.

    2008-01-01

    It is well known that an overexposure to ultraviolet radiation is associated with a number of health risks such as an increased risk of cataracts and skin cancers. At a time when climate change is often blamed for all our environmental problems, what is the latest news about the stratospheric ozone layer and other factors controlling ultraviolet radiation at the surface of the Earth? Will the expected changes in the chemical composition of the atmosphere and changes in our climate increase or decrease the risk for skin cancer? This article investigates the role of the various factors influencing ultraviolet radiation and presents the latest knowledge on the subject. (author)

  9. Some aspects of vacuum ultraviolet radiation physics

    CERN Document Server

    Damany, Nicole; Vodar, Boris

    2013-01-01

    Some Aspects of Vacuum Ultraviolet Radiation Physics presents some data on the state of research in vacuum ultraviolet radiation in association with areas of physics. Organized into four parts, this book begins by elucidating the optical properties of solids in the vacuum ultraviolet region (v.u.v.), particularly the specific methods of determination of optical constants in v.u.v., the properties of metals, and those of ionic insulators. Part II deals with molecular spectroscopy, with emphasis on the spectra of diatomic and simple polyatomic molecules, paraffins, and condensed phases. Part III

  10. Application of ultraviolet and infrared radiation in food

    OpenAIRE

    D Jafarpour; M Alizadeh; F Siamak

    2018-01-01

    BACKGROUND: There are many uses of radiation in the food industry. Radiation can be considered as one of the new processes and usage of it can offer new features of food. This process in most food doesn’t leave any physical or sensory changes. Therefore, in this review article, the application of ultraviolet and infrared radiation in food was studied. Methods: Search by the keywords “Ultraviolet Radiation Infrared Radiation Food” in databases Pubmed, Scopus and Web of Sci...

  11. Exposure to ultraviolet radiation: recommendations for cosmetic use

    International Nuclear Information System (INIS)

    Dias, C.; Carvalho, F.R.S.

    2000-01-01

    The beginning of the so-called tanning industry made possible the acquisition of a tanned skin independently of the available solar radiation. The tan is produced by ultraviolet radiation and, as well as in solar exposure, there are additional risks on the use of the so-called sun-beds. The damaging effects of ultraviolet exposure are well documented and reasonably quantified. The objective of this paper is to inform the potential effects of ultraviolet radiation exposure in sun-beds and to provide recommendations in order to reduce the associated risks. These recommendations are adapted for cosmetics use only (author)

  12. Natural and artificial ultraviolet radiation and skin cancer risk: what's new? Proceedings of the SFRP Non-ionizing radiation section round table

    International Nuclear Information System (INIS)

    Douki, Thierry; Boniol, Mathieu; Dore, Jean-Francois

    2015-12-01

    The Non-ionizing radiation section of the French Society of Radiation Protection (SFRP) organized a technical meeting on the current knowledge of UV mutagenicity mechanisms, on professional exposures and on the risks linked with artificial tanning and their prevention. This document brings together the 3 available presentations (slides) of the talks given at the meeting: 1 - UV induction of DNA photoproducts: recent data (Thierry DOUKI, CEA Grenoble); 2 - Professional exposure to UV radiations (Mathieu BONIOL, IPRI); 3 - Artificial tanning: a major but avoidable public health problem (Jean-Francois DORE, Centre de Recherche en Cancerologie)

  13. Formation of fatty acid esterified vitamin D3 in rat skin by exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Takada, K.

    1983-01-01

    The formation of fatty acid esters of vitamin D3 was demonstrated in rat skin exposed to artificial ultraviolet rays by using multi-dimensional high-performance liquid chromatography, ultraviolet spectrophotometry, and gas-liquid chromatography-mass spectrometry. This result indicated that the fatty acid esters of 7-dehydrocholesterol in rat skin (at least 80% of 7-dehydrocholesterol in rat skin is esterified) is also isomerized into vitamin D3 ester in vivo. The initial percentage of the esterified form was 84.3% and this did not significantly change up to the time when about half of the skin total vitamin D3 disappeared (2 days). Consequently, it was speculated that the vitamin D3 ester was delivered into the blood circulation from skin without having been hydrolyzed. This was supported by the presence of vitamin D3 ester in rat plasma exposed to ultraviolet radiation. In addition, in connection with the study of the restriction of vitamin D3 synthesis, distribution of total vitamin D3 in rat skin exposed to ultraviolet irradiation in vivo was compared with that in isolated skin exposed to ultraviolet radiation. The dermal layer of the isolated skin contained about 4 times more total vitamin D3 than that of in vivo skin. This finding suggests not only that ultraviolet rays could not penetrate deeply into the in vivo skin, but that the restriction of cutaneous synthesis of vitamin D3 observed in vivo may arise from this reduced penetration of ultraviolet rays

  14. Inhibition of seagrass photosynthesis by ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Trocine, R.P.; Rice, J.D.; Wells, G.N.

    1981-01-01

    Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme (Kuetz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ultraviolet-B were investigated. Halodule was found to possess the greatest photosynthetic tolerance for ultraviolet-B. Photosynthesis in Syringodium was slightly more sensitive to ultraviolet-B while Halophila showed relatively little photosynthetic tolerance. Evidence for a photorepair mechanism was found only in Halodule. Syringodium appeared to rely primarily on a thick epidermal cell layer to reduce photosynthetic damage. Halophila seemed to have no morphological or photorepair capabilities to deal with ultraviolet-B. This species appeared to rely on epiphytic and detrital shielding and the shade provided by other seagrasses to reduce ultraviolet-B irradiation to tolerable levels. The presence of epiphytes on leaf surfaces was found to reduce the extent of photosynthetic inhibition from ultraviolet-B exposure in all species. Halophila appears to obtain an increased photosynthetic tolerance to ultraviolet-B as an indirect benefit of chloroplast clumping to avoid photo-oxidation by intense levels of photosynthetically active radiation

  15. Does ultraviolet radiation affect the xanthophyll cycle in marine phytoplankton?

    NARCIS (Netherlands)

    van de Poll, W.H.; Buma, A.G.J.

    2009-01-01

    This Perspective summarizes the state of knowledge of the impact of ultraviolet radiation on the photoprotective xanthophyll cycle in marine phytoplankton. Excess photosynthetically active radiation (PAR; 400-700 nm) and ultraviolet radiation (UVR; 280-400 nm) affect various cellular processes and

  16. Occupational exposure to ultraviolet radiation and risk of non-melanoma skin cancer in a multinational European study.

    Directory of Open Access Journals (Sweden)

    Simona Surdu

    Full Text Available BACKGROUND: Studies suggest that ambient sunlight plays an important role in the pathogenesis of non-melanoma skin cancers (NMSC. However, there is ongoing controversy regarding the relevance of occupational exposure to natural and artificial ultraviolet radiation (UV radiation. OBJECTIVES: We investigated potential associations between natural and artificial UV radiation exposure at work with NMSC in a case-control study conducted in Hungary, Romania, and Slovakia. METHODS: Occupational exposures were classified by expert assessment for 527 controls and 618 NMSC cases (515 basal cell carcinoma, BCC. Covariate information was collected via interview and multiple logistic regression models were used to assess associations between UV exposure and NMSC. RESULTS: Lifetime prevalence of occupational exposure in the participants was 13% for natural UV radiation and 7% for artificial UV radiation. Significant negative associations between occupational exposure to natural UV radiation and NMSC were detected for all who had ever been exposed (odds ratio (OR 0.47, 95% confidence interval (CI 0.27-0.80; similar results were detected using a semi-quantitative metric of cumulative exposure. The effects were modified by skin complexion, with significantly decreased risks of BCC among participants with light skin complexion. No associations were observed in relation to occupational artificial UV radiation exposure. CONCLUSIONS: The protective effect of occupational exposure to natural UV radiation was unexpected, but limited to light-skinned people, suggesting adequate sun-protection behaviors. Further investigations focusing on variations in the individual genetic susceptibility and potential interactions with environmental and other relevant factors are planned.

  17. Ultra-violet radiation: hazard in workplaces? (part II)

    International Nuclear Information System (INIS)

    Mohd Yusof Mohd Ali

    2003-01-01

    Not many workers are aware that apart from chemicals, physical agents, noise and machines which are known to be hazardous in workplaces, there exist another source of hazard which is equally important to be recognised and respected, that is hazard due to ultrviolet radiation (UV). This is the continuation of part I, which was discussed in the later issue. In this part, hazard of ultraviolet radiation were briefly discused i.e. effects on the skin and the eyes. Other subjects discussed are exposure limits, how to assess the radiation, protection against ultraviolet radiation

  18. Experimental study of the ultraviolet global radiation in San Jose, Costa Rica

    International Nuclear Information System (INIS)

    Wright, J.

    1996-01-01

    The ultraviolet global radiation and the global solar radiation at San Jose, Costa Rica (latitude: 9 0 56', longitude: 84 0 54', altitude: 1.172 m.) during the period October 1993 to January 1995 were analyzed with respect to their seasonal variations and their independence. The dependence between the ultraviolet radiation and the clearness index of the skies was also investigated. A poor correlation was found between the quotient of the ultraviolet radiation (Hv/Hg) and between the global solar radiation and the extraterrestrial solar radiation (Hg/Ho). The correlation coefficient found between Hv/Hg and Hg/Ho was not greater than 0.25 for four categories of clearness index, i.e., covered skies, clear skies, and two intermediate conditions. This demonstrates that the ultraviolet radiation is not only associated with other atmospheric transmission conditions. A regression analysis between the hourly values of the ultraviolet and global radiation yielded a linear relationship with a determination coefficient greater than 98%. Thus a simple linear regression is reliable for the estimation of the ultraviolet in San Jose from global solar radiation data. (author) [es

  19. Solar ultraviolet radiation and the risk of infectious disease: summary of a workshop

    International Nuclear Information System (INIS)

    Chapman, R.S.; Cooper, K.D.; De Faro, E.C.

    1995-01-01

    This invited review summarizes papers presented in a workshop on solar radiation and the risk of infectious disease. Nine reviewers cover the current state of knowledge in the following relevant fields:-ultraviolet climatology, infectious disease in humans, effects of U.V. from artificial light sources on animal and human immune systems, the influence of solar U.V. on animal and human immune systems, (lab, field, and clinical studies), biological consequences of unrepaired solar induced human DNA damage, and epidemiological considerations. Group discussions preceded the preparation of summary statements on each topic. Extensive bibliography. (UK)

  20. Unintentional exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Sliney, D.H.

    1987-01-01

    To evaluate the risks from unintentional exposure to ultraviolet radiation (UVR), and to consider hazard control regulation, one must face first the problem of their state of scientific knowledge and the public's perception of UVR. Few people in the general public would question the health benefits of sunlight. Many flock to the beaches each summer to develop a healthy tan. Since the 1920's scientists have recognized that most of the benefits--and risks--of sunlight exposure result from the UVR present in sunlight. Dermatologists warn sunbathers to avoid exposure or protect themselves against the intense midday UVR or risk skin cancer. A growing number of scientists warn of hazards to the eye if UVR--perhaps even shorter visible wavelengths--are not filtered by lenses. In addition to any intentional exposure for health or cosmetic purposes, many people are also exposed to UVR without being aware of it or without their intent to be exposed. Outdoor workers are exposed to sunlight, many industrial workers (e.g., welders) are exposed to UVR from arc sources, some UVR penetrates clothing, and people indoors are exposed to UVR from artificial lighting

  1. Threat of ultraviolet radiation to the eye--how to protect against it

    International Nuclear Information System (INIS)

    Pitts, D.G.

    1981-01-01

    The purpose of this paper is to discuss the effects of exposure of the eye to ultraviolet (UV) radiation and to provide information from which protective criteria and standards may be established. To accomplish this purpose, the article discusses ultraviolet radiation, absorption of UV radiation by the eye, the effects of ocular exposure to ultraviolet radiation, and how to protect the eye against exposure to UV radiation

  2. Study of effect ultraviolet radiation on Aspergillus Flavus and Aspergillus Parasiticus

    International Nuclear Information System (INIS)

    Ghafourian, H.; Kafaei, F.; Raouf, J.B.

    2000-01-01

    In this article the results of ultraviolet radiation effects on Aspergillus Flavus and Aspergillus parasiticus to reach the quality control standards are presented. The purpose was to test the effect of ultraviolet radiation in 254 nanometer wavelength for fungi decontamination with respect to the exposure time of radiation and the distance between samples and radiation source. The ultraviolet radiation effects on plates containing Aspergillus Flavus and Aspergillus Parasiticus fungi were studied in the exposure time duration of 30, to 360 seconds of a fixed distance, and also for variable distances from 10 to 40 cm at a given exposure time. It is shown that in the exposure time of more than 360 second the ultraviolet radiation exposure highly decreases the number of Aspergillus Flavus and Aspergillus Parasiticus fungi colonies. By reducing the distance, the number of colonies decreases and it is minimized at a 10 cm distance in the time exposure of 360 second. The above results show that the ultraviolet radiation is an effective method for food decontamination and can be used in industry

  3. Inhibition of seagrass photosynthesis by ultraviolet-B radiation.

    Science.gov (United States)

    Trocine, R P; Rice, J D; Wells, G N

    1981-07-01

    Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme Kütz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ultraviolet-B were investigated.Halodule was found to possess the greatest photosynthetic tolerance for ultraviolet-B. Photosynthesis in Syringodium was slightly more sensitive to ultraviolet-B while Halophila showed relatively little photosynthetic tolerance. Evidence for a photorepair mechanism was found only in Halodule. This mechanism effectively attenuated photosynthetic inhibition induced by ultraviolet-B dose rates and dosages in excess of natural conditions. Syringodium appeared to rely primarily on a thick epidermal cell layer to reduce photosynthetic damage. Halophila seemed to have no morphological or photorepair capabilities to deal with ultraviolet-B. This species appeared to rely on epiphytic and detrital shielding and the shade provided by other seagrasses to reduce ultraviolet-B irradiation to tolerable levels. The presence of epiphytes on leaf surfaces was found to reduce the extent of photosynthetic inhibition from ultraviolet-B exposure in all species.Observations obtained in this study seem to suggest the possibility of anthocyanin and/or other flavonoid synthesis as an adaptation to long term ultraviolet-B irradiation by these species. In addition, Halophila appears to obtain an increased photosynthetic tolerance to ultraviolet-B as an indirect benefit of chloroplast clumping to avoid photo-oxidation by intense levels of photosynthetically active radiation.

  4. 21 CFR 179.39 - Ultraviolet radiation for the processing and treatment of food.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ultraviolet radiation for the processing and..., PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.39 Ultraviolet radiation for the processing and treatment of food. Ultraviolet radiation for the processing and treatment of food may be...

  5. Ultraviolet radiation therapy and UVR dose models

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, David Robert, E-mail: davidrobert.grimes@oncology.ox.ac.uk [School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland and Cancer Research UK/MRC Oxford Institute for Radiation Oncology, Gray Laboratory, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ (United Kingdom)

    2015-01-15

    Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed.

  6. Ultraviolet radiation therapy and UVR dose models

    International Nuclear Information System (INIS)

    Grimes, David Robert

    2015-01-01

    Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed

  7. An assessment of ultraviolet radiation components of light emitted ...

    African Journals Online (AJOL)

    An assessment of ultraviolet radiation components of light emitted from electric arc and their possible exposure risks. ... The study of Ultraviolet Radiation has of recent become interesting because of the health hazards it poses to human. Apart from its intensity reaching the earth from the sun, other man-made sources have ...

  8. Artificial UV sources in perspective

    International Nuclear Information System (INIS)

    Coppell, R.

    1993-01-01

    With rare exceptions, the sun is by far the most important source of exposure to ultraviolet radiation. This is the conclusion of a brief examination into use of artificial sources in New Zealand. (author). 1 tab

  9. Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

    Directory of Open Access Journals (Sweden)

    M. El Ghazaly

    Full Text Available Photoluminescence (PL emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53–4.43 eV but for a lower energy than 4.43 eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28 eV to 400 (3.10 eV nm in step of 10 nm and the corresponding photoluminescence (PL emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280 nm and have maximum at 290 nm, thereafter they decrease and diminish at 360 nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300 nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC, the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation. Keywords: Photoluminescence spectra, Makrofol® DE 1-1, UV–vis spectrophotometry, Attenuation coefficient, Ultraviolet radiation

  10. Nonionising radiation and risk of human cancer: comparison of ultraviolet and radiofrequency radiation

    International Nuclear Information System (INIS)

    Green, A.

    2003-01-01

    Human exposure to ultraviolet radiation (UVR) comes largely from sunlight, although a small proportion of people receive high dose UVR from artificial sources. The causal link between solar UVR and the keratinocyte cancers, basal cell carcinomas and squamous cell carcinomas of the skin, is well-established based on a large body of observational and experimental evidence. UVR damages molecules such as DNA directly and this is the principal mechanism of carcinogenesis, though other mechanisms such as immunosuppression and interaction with viruses may also be involved. People are also exposed to another form of nonionising radiation, radiofrequency radiation (RFR), through occupation, the community environment from base stations, and through use of cellular telephones and related communications devices. However, unlike UVR, the relationship between RFR and cancer is far from clear. The main tumours that have been investigated to date are brain tumours and leukaemia but assessing the RFR exposure pathway to such cancers poses many methodological challenges for epidemiologists. Refinements to measurement of exposure are the major urgent need, and the lack of evidence regarding carcinogenic effects of RFR in experimental settings complicates the assessment. Further insights into the links between RFR and chronic disease such as cancer are likely in the next few years however when results of several large-scale epidemiological studies now in train around the world become available

  11. Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

    Science.gov (United States)

    El Ghazaly, M.; Aydarous, Abdulkadir

    Photoluminescence (PL) emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate) upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53-4.43 eV but for a lower energy than 4.43 eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28 eV) to 400 (3.10 eV) nm in step of 10 nm and the corresponding photoluminescence (PL) emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL) bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280 nm and have maximum at 290 nm, thereafter they decrease and diminish at 360 nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300 nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC), the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation.

  12. PMMA Wettability Caused by Ultraviolet Radiation

    OpenAIRE

    Dehtjars, J; Lancere, L; Poļaka, N; Soudnikovich, A; Tjuļkins, F; Valters, V

    2010-01-01

    The article is targeted to explore ultraviolet radiation (UV) influence on PMMAf or eye prostheses. UV beingt he Sun lightc omponenta nd could effect PMMA surface that in turn contributesi nteractionw ith tear. PMMA wettabilityw as poweredb y UV.

  13. Photosynthetic carbon reduction by seagrasses exposed to ultraviolet A radiation

    Science.gov (United States)

    1979-01-01

    The seagrasses Halophila engelmannii, Halodule wrightii, and Syringodium filiforme were examined for their intrinsic sensitivity to ultraviolet-A-UV-A and ultraviolet-B-UV-B radiation. The effect of UV-A on photosynthetically active radiation (PAR) was also determined. Ultraviolet-A and ultraviolet-B were studied with emphasis on the greater respective environmental consequence in terms of seagrass distribution and abundance. Results indicate that an intrinsic sensitivity to UV-A alone is apparent only in Halophila, while net photosynthesis in Halodule and Syringodium seems unaffected by the level of UV-A provided. The sensitivity of Halophila to UV-A in the absense of (PAR) indicates that the photosynthetic reaction does not need to be in operation for damage to occur. Other significant results are reported.

  14. Ultraviolet solar radiation and the prevention of erythema

    International Nuclear Information System (INIS)

    Tena, F.; Martinez-Lozano, J.A.; Utrillas, M.P.

    1998-01-01

    An ultraviolet index appropriate for its use in Spain is studied on the basis of those already available in other countries. The suitability of this index to characterise ultraviolet solar radiation and, particularly, the potential risks to human health are discussed. Finally, the main factors affecting this index are identified and their influence is studied. (Author) 43 refs

  15. The impact of ultraviolet radiation on timber

    International Nuclear Information System (INIS)

    Dawson, B.

    1993-01-01

    Photochemical degradation of timber, the outcome of exposure of timber to ultraviolet radiation, is a light induced chemical and physical decay. Timber is a collection of dead wood cells. Impacts of radiation on the growing tree are therefore outside the scope of this paper, which is primarily concerned with timber as a material. (author). 5 refs. 2 figs

  16. Ultraviolet radiation, human health, and the urban forest

    Science.gov (United States)

    Gordon M. Heisler; Richard H. Grant

    2000-01-01

    Excess exposure to ultraviolet (UV) radiation from the sun, particularly the ultraviolet B (UVB) portion, has been linked with adverse effects on human health ranging from skin cancers to eye diseases such as cataracts. Trees may prevent even greater disease rates in humans by reducing UV exposure. Tree shade greatly reduces UV irradiance when both the sun and sky are...

  17. Solar ultraviolet radiation from cancer induction to cancer prevention: solar ultraviolet radiation and cell biology.

    Science.gov (United States)

    Tuorkey, Muobarak J

    2015-09-01

    Although decades have elapsed, researchers still debate the benefits and hazards of solar ultraviolet radiation (UVR) exposure. On the one hand, humans derive most of their serum 25-hydroxycholecalciferol [25(OH)D3], which has potent anticancer activity, from solar UVB radiation. On the other hand, people are more aware of the risk of cancer incidence associated with harmful levels of solar UVR from daily sunlight exposure. Epidemiological data strongly implicate UV radiation exposure as a major cause of melanoma and other cancers, as UVR promotes mutations in oncogenes and tumor-suppressor genes. This review highlights the impact of the different mutagenic effects of solar UVR, along with the cellular and carcinogenic challenges with respect to sun exposure.

  18. Measurements of integrated direct, diffuse and global ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Utrillas, M.P.; Pedrós, R.; Gandía, S.; Gómez-Amo, J.L.; Estellés, V.; Martínez-Lozano, J.A.

    2015-01-01

    We present the first multiyear set of simultaneous measurements of the global ultraviolet-B radiation and its two components: direct and diffuse. The measurements have been taken with four YES-UVB-1 radiometers: two radiometers to measure the diffuse radiation, one provided with a shadow band and the other with a shadow disk on a Sun tracker; a radiometer to measure the global horizontal radiation; and a Sun-tracking radiometer to measure the direct radiation with an especially designed radiance collimator. The diffuse minute-values measured with both instruments agree within a coefficient correlation of 1.00. The diffuse component represents at least 50% of the global UVB (ultraviolet-B) radiation. The minute values of global UVB irradiance obtained by adding the direct and diffuse components concur with the measured global irradiance. Therefore, the measurement of the direct irradiance enables the estimation of the diffuse component, and gives an insight into the factors that affect its value, especially aerosols. - Highlights: • Simultaneous measurements of global, direct and diffuse UVB (ultraviolet-B) radiation. • The diffuse minute-values are at least 50% of the global ones. • The diffuse measurements are highly correlated to the aerosol load. • The sum of direct + diffuse radiation concur with the measured global.

  19. Ultraviolet radiation and blue-light emissions from spotlights incorporating tungsten halogen lamps

    CERN Document Server

    MacKinlay, Alistair F; Whillock, M J

    1989-01-01

    This report summarises measurements of the ultraviolet radiation and blue-light emissions from eleven 'desk-top' tungsten halogen (quartz) lamps and one 'floor-standing' tungsten halogen (quartz) lamp available in the UK. Values of occupational hazard weighted and erythemally weighted ultraviolet radiation irradiance and measurements and relevant calculations of blue-light hazards are presented. It is concluded that the safety design of some desk-top tungsten halogen lamps is inadequate to prevent unnecessary exposure of the skin to potentially harmful ultraviolet radiation. It is recommended that all tungsten halogen lamps should have sufficient filtration to reduce their ultraviolet emissions to an acceptably low level. As long as the comfort aversion responses of the eye are respected, direct viewing of the lamps examined should not constitute a retinal hazard.

  20. Ultraviolet radiation and blue-light emissions from spotlights incorporating tungsten halogen lamps

    International Nuclear Information System (INIS)

    McKinlay, A.F.; Whillock, M.J.; Meulemans, C.C.E.

    1989-07-01

    This report summarises measurements of the ultraviolet radiation and blue-light emissions from eleven 'desk-top' tungsten halogen (quartz) lamps and one 'floor-standing' tungsten halogen (quartz) lamp available in the UK. Values of occupational hazard weighted and erythemally weighted ultraviolet radiation irradiance and measurements and relevant calculations of blue-light hazards are presented. It is concluded that the safety design of some desk-top tungsten halogen lamps is inadequate to prevent unnecessary exposure of the skin to potentially harmful ultraviolet radiation. It is recommended that all tungsten halogen lamps should have sufficient filtration to reduce their ultraviolet emissions to an acceptably low level. As long as the comfort aversion responses of the eye are respected, direct viewing of the lamps examined should not constitute a retinal hazard. (author)

  1. Ultraviolet radiation in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Taalas, P; Koskela, T; Damski, J; Supperi, A [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

    1997-12-31

    Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s research projects. The main national level effort has been the Finnish Academy`s climatic change programme, SILMU 1990-95. This presentation summarises the scientific results reached during the SILMU project

  2. Ultraviolet radiation in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Taalas, P.; Koskela, T.; Damski, J.; Supperi, A. [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E. [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

    1996-12-31

    Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s research projects. The main national level effort has been the Finnish Academy`s climatic change programme, SILMU 1990-95. This presentation summarises the scientific results reached during the SILMU project

  3. Ultraviolet radiation

    International Nuclear Information System (INIS)

    Faber, M.

    1989-01-01

    Although UV radiation can arise from a large number of man-made sources, the sun is the main source and both the general public and people working out of doors will be exposed to it. This natural background radiation and the variations in its magnitude must be taken into account when exposure limits are discussed. The full extent to which UV affects human well-being is difficult to quantify. Artificially produced UV has, however, been used in mines and cellars and in far northern latitudes as a supplement to combat functional impairment among people. Many of the observed effects, such as a decrease in the incidence of infectious diseases and in absenteeism, may be due to the bactericidal nature of the radiation. On the other hand, large doses of UV have an acute destructive effect on the skin and eye. Doses so low that they give rise only to normally acceptable or even desirable acute effects can, if repeated, induce changes resulting in late effects such as elastosis of the skin, keratosis and skin cancers. These effects will be of greater significance in people with lightly pigmented skin. 130 refs, 13 figs, 2 tabs

  4. Novel photoinducible protective system in the Candida Guilliermondii under mid-ultraviolet radiation effect

    International Nuclear Information System (INIS)

    Frajkin, G.Ya.; Pinyaskina, E.V.; Strakhovskaya, M.G.

    1995-01-01

    Resistance of the Candida guilliermondii cells to ultraviolet radiation (290-320 nm, 400-750 nm) is studied. Presence of previously unknown photoinducible protective mechanism in yeasts, providing for increase in cell stability to mid-ultraviolet radiation, biologically most active in the solar radiation spectrum, is revealed. 9 refs.; 3 figs

  5. Solar ultraviolet radiation cataract.

    Science.gov (United States)

    Löfgren, Stefan

    2017-03-01

    Despite being a treatable disease, cataract is still the leading cause for blindness in the world. Solar ultraviolet radiation is epidemiologically linked to cataract development, while animal and in vitro studies prove a causal relationship. However, the pathogenetic pathways for the disease are not fully understood and there is still no perfect model for human age related cataract. This non-comprehensive overview focus on recent developments regarding effects of solar UV radiation wavebands on the lens. A smaller number of fundamental papers are also included to provide a backdrop for the overview. Future studies are expected to further clarify the cellular and subcellular mechanisms for UV radiation-induced cataract and especially the isolated or combined temporal and spatial effects of UVA and UVB in the pathogenesis of human cataract. Regardless of the cause for cataract, there is a need for advances in pharmaceutical or other treatment modalities that do not require surgical replacement of the lens. Copyright © 2016. Published by Elsevier Ltd.

  6. Failure of supplementary ultraviolet radiation to enhance flower color under greenhouse conditions

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R. M. [University of Vermont, Burlington, VT (United States)

    1990-03-15

    In order to determine whether the concentration of floral petal anthocyanin pigments could be increased, ultraviolet radiations in the UV-A and UV-B wavelength bands were presented to a variety of flowering plants to partly restore those wavelengths filtered out by greenhouse glass. In no tested plant did the supplementary ultraviolet radiation enhance floral anthocyanin content. Supplementary UV radiation has no economic value in greenhouse production of flowering plants. (author)

  7. The effect of ultraviolet radiation on the cornea - experimental study.

    Science.gov (United States)

    Golu, Andreea; Gheorghişor, Irina; Bălăşoiu, A T; Baltă, Fl; Osiac, E; Mogoantă, L; Bold, Adriana

    2013-01-01

    Ultraviolet (UV) radiation in high doses may have harmful effects on the eye. The sources of UV radiation are the sun, as well as some artificial sources such as UV lamps or voltaic arcs. Chronic exposure to UV can cause damage to the anterior pole of the eye, ranging from minor (pterygium) to serious photokeratitis. In our study, we applied a UV dose of 6.5 J/cm(2) in the wavelength range of 290-400 nm, for five consecutive days per rat anterior pole of the eye. Seven days after the last dose of radiation, the animals were sacrificed, harvesting both the irradiated and the non-irradiated eye. Histological and immunohistochemical examination of the lesions revealed that the greatest damage to the epithelium was recorded prior to and 2/3 of the remaining corneal stroma. The epithelial lesions we found varied from pseudokeratosis and detachment of the Bowman epithelium membrane to deep epithelial necrosis. Within the corneal stroma, we observed the formation of interstitial edema with disruption of the collagen structure. We also noticed the presence of an inflammatory infiltrate composed mainly of lymphocytes and CD68+ and CD163+ macrophages, as well as the occurrence of vascular devices. These consisted of angiogenesis capillaries with structured wall composed mainly of endothelial CD34+ precursor cells and a basal membrane rich in collagen IV fibers.

  8. Effects of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation

    International Nuclear Information System (INIS)

    Zhang Lei; Wang Lianxi; Li Fusheng

    2009-01-01

    [Objective]The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures.[Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height , leaf area and number of green leaves under influences of different UV-B radiation. [Result]In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influenced and with the increase of ultraviolet radiation-B, the yield declined dramatically.[Conclusion]The result of this experiment would be good for maize production in arid regions of middle-high elevation

  9. Evaluating the clinical and physiological effects of long term ultraviolet B radiation on guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Watson, Megan K; Stern, Adam W; Labelle, Amber L; Joslyn, Stephen; Fan, Timothy M; Leister, Katie; Kohles, Micah; Marshall, Kemba; Mitchell, Mark A

    2014-01-01

    Vitamin D is an important hormone in vertebrates. Most animals acquire this hormone through their diet, secondary to exposure to ultraviolet B (UVB) radiation, or a combination thereof. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on guinea pigs (Cavia porcellus) and to evaluate the long-term safety of artificial UVB light supplementation over the course of six months. Twelve juvenile acromelanic Hartley guinea pigs were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received only ambient fluorescent light for 12 hours daily. Animals in both groups were offered the same diet and housed under the same conditions. Blood samples were collected every three weeks to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations, computed tomography scans, and dual energy x-ray absorptiometry scans were performed during the course of the study. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly in the guinea pigs (pguinea pigs to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, and that this increase was sustainable over time. Providing guinea pigs exposure to UVB may be an important husbandry consideration that is not currently recommended.

  10. Solar ultraviolet hazards

    International Nuclear Information System (INIS)

    Azmah Ali

    1995-01-01

    The paper discussed the following subjects: the sources of ultraviolet radiation, solar ultraviolet radiation definition, effects of over exposure to solar ultraviolet radiation, exposure limits and radiation protection of this radiation

  11. Solar ultraviolet radiation in a changing climate

    Science.gov (United States)

    The projected large increases in damaging ultraviolet radiation as a result of global emissions of ozone-depleting substances have been forestalled by the success of the Montreal Protocol. New challenges are now arising in relation to climate change. We highlight the complex inte...

  12. Ultraviolet - status of knowledge on exposure and health risks

    International Nuclear Information System (INIS)

    Dervault, Anne Marie; Secretan, Beatrice; Guinot, Christiane; Bazex, Jacques; Donadieu, Jean; Dore, Jean Francois; Cesarini, Jean Pierre; Aleth Richard, Marie; Leccia, Marie Therese; Autier, Philippe; Cesarini, Jean Pierre; Beani, Jean Claude; Grob, Jean Jacques; Wald, Lucien; Dore, Jean Francois; Casiniere, Alain de la; Dixsaut, Gilles; Guenel, Pascal; Choulika, Sophie; Pirard, Philippe; Bastuji-Garin, S.; Beani, J.C.; Brin, A.J.; Cadet, J.; Corre, M.F.; Frelon, J.H.; Grob, Jean Jacques; Jeanmougin, M.; Martini-Morel, M.C.; Meunier, L.; Marty, J.P.; Revuz, J.; Reynier, J.P.; Roelands, R.; Stoebner, A.; Vian, L.

    2005-05-01

    After having recalled some physical aspects of ultraviolet radiations (presence in solar radiation, artificial UV radiation, measurement, metrology, UV index, boundary limits), this report describes the biological and health effects of UV radiations (analysis methodology, recall of previous expert reports, biological effects, health effects), addresses human behaviour with respect to UV radiation and exposure to UV radiation, discusses the relationship between cosmetics and UV radiation. It presents the various European and international positions with respect to UV emitting devices (evolution of standards, regulations). Some recommendations are made regarding solar exposure, sun-tanning installations, and other domestic or industrial sources

  13. Utilization of ultraviolet radiation of cold hollow cathode discharge plasma for water disinfection

    International Nuclear Information System (INIS)

    Soloshenko, I.O.; Bazhenov, V.Yu.; Khomych, V.O.; Tsiolko, V.V.; Potapchenko, N.G.; Goncharuk, V.V.

    2006-01-01

    We study the possibility to use the ultraviolet radiation of a hollow cathode discharge plasma for water disinfection. We have performed the comparative experiments on the influence of ultraviolet radiation of the mentioned discharge plasma, as well as that of a standard low pressure mercury lamp

  14. Assessment of the impact of increased solar ultraviolet radiation upon marine ecosystems

    Science.gov (United States)

    Worrest, R. C.; Vandyke, H.

    1978-01-01

    Reduction of the earth's ozone layer, with a resultant increase in transmission of solar ultraviolet radiation in the 290 to 320nm waveband (UV-B), via space shuttle operations through the stratosphere is considered. It is shown that simulated solar ultraviolet radiation can, under experimental conditions, detrimentally affect the marine organisms that form the base of the food web of oceanic and estuarine ecosystems. Whether a small increase in biologically harmful ultraviolet radiation might overwhelm these mechanisms and produce changes that will have damaging consequences to the biosphere is discussed. The potential for irreversible damage to the productivity, structure and/or functioning of a model estuarine ecosystem by increased UV-B radiation and whether these ecosystems are highly stable or amenable to adaptive change is studied. Data are provided to assess the potential impact upon marine ecosystems if space shuttle operations contribute to a reduction of the stratospheric ozone layer and the sensitivity of key community components to increased UV-B radiation is examined.

  15. Mutation induction by 365-nm radiation and far-ultraviolet light in Escherichia coli differing in near- and far-ultraviolet light sensitivity

    International Nuclear Information System (INIS)

    Leonardo, J.M.; Reynolds, P.R.; Tuveson, R.W.

    1984-01-01

    The his-4 locus derived from Escherichia coli strain AB1157 has been transduced into 4 E. coli strains that exhibit all 4 possible combinations of genes controlling sensitivity to near-ultraviolet light (nur versus nur + ) and far-ultraviolet light (uvrA6 versus uvrA + ). The 4 strains exhibited the predicted sensitivity to 254-nm radiation based on the sensitivity of the parent strains from which they were derived and the frequency of his + mutations predicted from experiments with AB1157 from which the his-4 locus was derived. When the 4 strains were treated with 365-nm radiation, they exhibited the predicted sensitivity based on the near-ultraviolet light sensitivity of the strains from which they were derived while his + mutations were undetectable with the 4 strains as well as with strain AB1157. When treated with 365-nm radiation, cells of a WP2sub(s) strain (a derivative of B/r transduced to his-4) plated on semi-enriched medium prepared with casamino acids did not yield induced mutations, whereas plating on semi-enriched medium prepared with nutrient broth did yield mutants at both the his-4 and trp loci at frequencies at least an order of magnitude lower than that observed with far-ultraviolet light. The induction of nutritionally independent mutants by 365-nm radiation is strongly dependent on the supplement used for semi-enrichment. When compared at equivalent survival levels, mutant frequencies are significantly less following 365-nm radiation when compared with far-ultraviolet radiation. (Auth.)

  16. Establishing a ultraviolet radiation observational network and enhancing the study on ultraviolet radiation

    Science.gov (United States)

    Bai, Jianhui; Wang, Gengchen

    2003-09-01

    On the basis of analyzing observational data on solar radiation, meteorological parameters, and total ozone amount for the period of January 1990 to December 1991 in the Beijing area, an empirical calculation method for ultraviolet radiation (UV) in clear sky is obtained. The results show that the calculated values agree well with the observed, with maximum relative bias of 6.2% and mean relative bias for 24 months of 1.9%. Good results are also obtained when this method is applied in Guangzhou and Mohe districts. The long-term variation of UV radiation in clear sky over the Beijing area from 1979 to 1998 is calculated, and the UV variation trends and causes are discussed: direct and indirect UV energy absorption by increasing pollutants in the troposphere may have caused the UV decrease in clear sky in the last 20 years. With the enhancement of people’s quality of life and awareness of health, it will be valuable and practical to provid UV forecasts for typical cities and rural areas. So, we should develop and enhance UV study in systematic monitoring, forecasting, and developing a good and feasible method for UV radiation reporting in China, especially for big cities.

  17. The use of shore wave ultraviolet radiation for disinfection in operating rooms

    International Nuclear Information System (INIS)

    Baanrud, H.; Moan, J.

    1999-01-01

    Over a number of years short wave ultraviolet radiation (UVC;200-280 nm) has been used to disinfect air and surfaces in operating rooms, patient rooms and laboratories, as well as air in ventilation ducts. Despite the well-documented effect of ultraviolet radiation on air quality, this technology has been relatively little used. One advantage of this method is that the UVC sources ensure a continuous reduction in the number of airborne microorganisms that are generated all the time. There are, however, some disadvantages with this method. Human exposure to ultraviolet C may cause keratoconjunctivitis and erythema and requires protection of the skin and the eyes of people exposed to levels above recommended exposure limits. However, by enclosing the UVC sources or by irradiation in the absence of human activity, human exposure is eliminated. These and other aspects concerning the use of short wave ultraviolet radiation as a disinfection agent in operating rooms are discussed in this article

  18. Effective polycrystalline sensor of ultraviolet radiation

    Directory of Open Access Journals (Sweden)

    S.Yu. Pavelets

    2017-10-01

    Full Text Available Deposition of special thin layers with high and low resistance in space charge region of surface barrier photoconverters based on the p-Cu1.8S/n-CdS structure leads to a sufficient increase in photosensitivity and decrease in dark tunneling-recombination current. Highly efficient and stable polycrystalline photoconverters of ultraviolet radiation based on polycrystalline CdS have been obtained. Electrical and photoelectric properties have been investigated, and the main operational parameters of ultraviolet sensors have been adduced. The reasons for high stability of the parameters inherent to the p-Cu1.8S/n-CdS sensors are as follows: the absence of impurity components additionally doped to the barrier structure and stability of the photocurrent photoemission component.

  19. Dose modeling in ultraviolet phototherapy

    International Nuclear Information System (INIS)

    Grimes, David Robert; Robbins, Chris; O'Hare, Neil John

    2010-01-01

    Purpose: Ultraviolet phototherapy is widely used in the treatment of numerous skin conditions. This treatment is well established and largely beneficial to patients on both physical and psychological levels; however, overexposure to ultraviolet radiation (UVR) can have detrimental effects, such as erythemal responses and ocular damage in addition to the potentially carcinogenic nature of UVR. For these reasons, it is essential to control and quantify the radiation dose incident upon the patient to ensure that it is both biologically effective and has the minimal possible impact on the surrounding unaffected tissue. Methods: To date, there has been little work on dose modeling, and the output of artificial UVR sources is an area where research has been recommended. This work characterizes these sources by formalizing an approach from first principles and experimentally examining this model. Results: An implementation of a line source model is found to give impressive accuracy and quantifies the output radiation well. Conclusions: This method could potentially serve as a basis for a full computational dose model for quantifying patient dose.

  20. Human exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Bernhardt, J.H.; Matthes, R.

    1987-01-01

    Ultraviolet radiation is that part of the electromagnetic spectrum located between the softest ionizing radiation and visible radiation. The lower limit of 100 nm is equivalent to photon energies of 12.4 eV, which corresponds approximately to the limit for the production of ionization in biologically important materials. A historical subdividing of the UV-region takes some of the biological effects into account. In this arrangement the range 400-315 nm, the so-called black light region, is called UV-A. In this wavelength region, fluorescence can be induced in many substances. UV-B covers the range 315-280 nm (the skin erythemal region). Most of the biologically active and potentially harmful UV from the sun reaching the surface of the earth is part of this spectral region. UV-C includes the radiation of wavelengths less than 280 nm (the germicidal region). It should be noted that this classification is somewhat arbitrary, and today it is more usual to evaluate the biological effectiveness of the whole UV-range from 200 to 400 nm

  1. Ultraviolet radiation response of two heterotropy Antarctic marine bacterial

    International Nuclear Information System (INIS)

    Hernandez, Edgardo A.; Ferreyra, Gustavo A.; Mac Cormack, Walter P.

    2004-01-01

    Two Antarctic marine bacterial strains, were exposed to different irradiance of ultraviolet (UV) solar radiation using several experimental protocols and interferential filters. Results showed that both, UV-A and UV-B radiation produce deleterious effects on two tested bacterial strains. The mortality values under UVB treatments were higher than those observed under UVA treatments. UVvi strain proved to be more resistant to UV radiation than the UVps strain. (author) [es

  2. Ultraviolet Radiation Dose National Standard of México

    Science.gov (United States)

    Cardoso, R.; Rosas, E.

    2006-09-01

    We present the Ultraviolet (UV) Radiation Dose National Standard for México. The establishment of this measurement reference at Centro Nacional de Metrología (CENAM) eliminates the need of contacting foreign suppliers in the search for traceability towards the SI units when calibrating instruments at 365 nm. Further more, the UV Radiation Dose National Standard constitutes a highly accurate and reliable source for the UV radiation dose measurements performed in medical and cosmetic treatments as in the the food and pharmaceutics disinfection processes, among other.

  3. Null bactericidal effect of ultraviolet radiation emitted by LEDs.

    Directory of Open Access Journals (Sweden)

    Francisco Alcántara Muñoz

    2016-11-01

    Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

  4. Effects of ultraviolet radiation, visible light, and infrared radiation on erythema and pigmentation: a review.

    Science.gov (United States)

    Sklar, Lindsay R; Almutawa, Fahad; Lim, Henry W; Hamzavi, Iltefat

    2013-01-01

    The effects of ultraviolet radiation, visible light, and infrared radiation on cutaneous erythema, immediate pigment darkening, persistent pigment darkening, and delayed tanning are affected by a variety of factors. Some of these factors include the depth of cutaneous penetration of the specific wavelength, the individual skin type, and the absorption spectra of the different chromophores in the skin. UVB is an effective spectrum to induce erythema, which is followed by delayed tanning. UVA induces immediate pigment darkening, persistent pigment darkening, and delayed tanning. At high doses, UVA (primarily UVA2) can also induce erythema in individuals with skin types I-II. Visible light has been shown to induce erythema and a tanning response in dark skin, but not in fair skinned individuals. Infrared radiation produces erythema, which is probably a thermal effect. In this article we reviewed the available literature on the effects of ultraviolet radiation, visible light, and infrared radiation on the skin in regards to erythema and pigmentation. Much remains to be learned on the cutaneous effects of visible light and infrared radiation.

  5. The influence of infrared radiation on short-term ultraviolet-radiation-induced injuries

    International Nuclear Information System (INIS)

    Kaidbey, K.H.; Witkowski, T.A.; Kligman, A.M.

    1982-01-01

    Because heat has been reported to influence adversely short- and long-term ultraviolet (UV)-radiation-induced skin damage in animals, we investigated the short-term effects of infrared radiation on sunburn and on phototoxic reactions to topical methoxsalen and anthracene in human volunteers. Prior heating of the skin caused suppression of the phototoxic response to methoxsalen as evidenced by an increase in the threshold erythema dose. Heat administered either before or after exposure to UV radiation had no detectable influence on sunburn erythema or on phototoxic reactions provoked by anthracene

  6. Key issues of ultraviolet radiation of OH at high altitudes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhuai; Wan, Tian; Jiang, Jianzheng; Fan, Jing [State Key Laboratory of High Temperature Gasdynamics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-12-09

    Ultraviolet (UV) emissions radiated by hydroxyl (OH) is one of the fundamental elements in the prediction of radiation signature of high-altitude and high-speed vehicle. In this work, the OH A{sup 2}Σ{sup +}→X{sup 2}Π ultraviolet emission band behind the bow shock is computed under the experimental condition of the second bow-shock ultraviolet flight (BSUV-2). Four related key issues are discussed, namely, the source of hydrogen element in the high-altitude atmosphere, the formation mechanism of OH species, efficient computational algorithm of trace species in rarefied flows, and accurate calculation of OH emission spectra. Firstly, by analyzing the typical atmospheric model, the vertical distributions of the number densities of different species containing hydrogen element are given. According to the different dominating species containing hydrogen element, the atmosphere is divided into three zones, and the formation mechanism of OH species is analyzed in the different zones. The direct simulation Monte Carlo (DSMC) method and the Navier-Stokes equations are employed to compute the number densities of the different OH electronically and vibrationally excited states. Different to the previous work, the trace species separation (TSS) algorithm is applied twice in order to accurately calculate the densities of OH species and its excited states. Using a non-equilibrium radiation model, the OH ultraviolet emission spectra and intensity at different altitudes are computed, and good agreement is obtained with the flight measured data.

  7. Effects of emollients on ultraviolet-radiation-induced erythema of the skin

    International Nuclear Information System (INIS)

    Schleider, N.R.; Moskowitz, R.S.; Cort, D.H.; Horwitz, S.N.; Frost, P.

    1979-01-01

    Several commonly used emollients were studied as to their effectiveness in absorbing and filtering erythema-causing ultraviolet radiation in the 280 to 315 nm range (UVB). Planter's Peanut Oil (Standard Brands) and Mazola Corn Oil (Best Foods Inc.) had no effect; Alpha Keri Bath Oil (Westwood Pharmaceuticals), mineral oil, and Johnson's Baby Oil (Johnson and Johnson Co) had minimal effects. Vaseline Petroleum Jelly (Chesebrough-Ponds Inc.), petrolatum, and hydrophilic ointment substantially reduced the erythema that was induced by exposure to low doses of UVB radiation. Therefore, these emollients may interfere with the therapeutic effects of the ultraviolet radiation component of the Goeckerman treatment when it is administered in low doses to patients with psoriasis

  8. Thermoluminescent phosphors for ultraviolet radiation dosimetry - a review

    International Nuclear Information System (INIS)

    Nagpal, J.S.

    2001-01-01

    Intrinsic TL response of CaSO 4 , CaF 2 , Al 2 O 3 (Si,Ti), Mg 2 SiO 4 : Tb and lamp phosphors to ultraviolet radiation is reviewed. Taking into consideration the characteristics such as afterglow at RT, rate/flux dependence, linearity of response, useful range, spectral dependence and effect of sequential/tandem UV exposures CaF 2 :Eu 2+ is an ideal TL dosemeter for UV radiation dosimetry. (author)

  9. Near-ultraviolet radiation-induced damage using an actinic reticuloid strain as a possible sensitive model

    International Nuclear Information System (INIS)

    Kralli, A.

    1987-01-01

    The introduction to this thesis consists of a review of current concepts regarding the effects of ultraviolet radiation on living cells. Actinic reticuloid, a disease condition for which a near-ultraviolet radiation cellular sensitivity has been proposed as an underlying cause, is described. The experimental work, the broad aim of which is to expand existing knowledge of the effects of near-ultraviolet radiation that may lead to cell lethality, has centred upon the irradiation of a normal human skin fibroblast strain, GM730, and a strain derived from an actinic reticuloid patient, AR6LO. Parts 1 and 2 examine the effects of the irradiation on both normal and actinic fibroblast sensitivities to a range of ultraviolet wavelengths. The next two sections include observations on the protective effect of Trolox-C, a vitamin E analogue and the sensitization resulting from the replacement of the irradiation medium by a deuterated one, using both normal and actinic reticuloid fibroblasts. The final part examines broad-band near- and far-ultraviolet radiation induced membrane damage by the use of radioactively labelled rubidium as a potassium analogue. (author)

  10. Effects of ultraviolet-B radiation on phytoplankton - zooplankton interactions = [Effecten van ultraviolet-B straling op interacties tussen fytoplankton en zooplankton

    NARCIS (Netherlands)

    Lange, de H.J.

    1999-01-01

    The decrease in stratospheric ozone concentration has received wide attention because the ozone layer protects the earth from harmful ultraviolet-B radiation (UVB, 280-320 nm). UVB radiation is harmful for organisms, and therefore scientific research into how UVB radiation affects organisms

  11. Comprehensive Review of Ultraviolet Radiation and the Current Status on Sunscreens

    Science.gov (United States)

    Moon, Summer; Armstrong, Frank

    2012-01-01

    In the past, manufacturers’ labeling of sunscreen varied greatly, confusing the consumers regarding efficacy and the appropriate photoprotection provided by their products. Therefore, in June 2011, the United States Food and Drug Administration issued new guidelines for sunscreen labeling. Sunscreen products are over-the-counter drugs; therefore, they are regulated by the United States Food and Drug Administration to determine safety, efficacy, and labeling. This article discusses ultraviolet radiation and the positive and negative effects of ultraviolet radiation, provides a review of sunscreens, and discusses the new United States Food and Drug Administration regulations for sunscreens. PMID:23050030

  12. Detection of ultraviolet radiation using tissue equivalent radiochromic gel materials

    International Nuclear Information System (INIS)

    Bero, M A; Abukassem, I

    2009-01-01

    Ferrous Xylenol-orange Gelatin gel (FXG) is known to be sensitive to ionising radiation such as γ and X-rays. The effect of ionising radiation is to produce an increase in the absorption over a wide region of the visible spectrum, which is proportional to the absorbed dose. This study demonstrates that FXG gel is sensitive to ultraviolet radiation and therefore it could functions as UV detector. Short exposure to UV radiation produces linear increase in absorption measured at 550nm, however high doses of UV cause the ion indicator colour to fad away in a manner proportional to the incident UV energy. Light absorbance increase at the rate of 1.1% per minute of irradiation was monitored. The exposure level at which the detector has linear response is comparable to the natural summer UV radiation. Evaluating the UV ability to pass through tissue equivalent gel materials shows that most of the UV gets absorbed in the first 5mm of the gel materials, which demonstrate the damaging effects of this radiation type on human skin and eyes. It was concluded that FXG gel dosimeter has the potential to offer a simple, passive ultraviolet radiation detector with sensitivity suitable to measure and visualises the natural sunlight UV exposure directly by watching the materials colour changes.

  13. Detection of ultraviolet radiation using tissue equivalent radiochromic gel materials

    Science.gov (United States)

    Bero, M. A.; Abukassem, I.

    2009-05-01

    Ferrous Xylenol-orange Gelatin gel (FXG) is known to be sensitive to ionising radiation such as γ and X-rays. The effect of ionising radiation is to produce an increase in the absorption over a wide region of the visible spectrum, which is proportional to the absorbed dose. This study demonstrates that FXG gel is sensitive to ultraviolet radiation and therefore it could functions as UV detector. Short exposure to UV radiation produces linear increase in absorption measured at 550nm, however high doses of UV cause the ion indicator colour to fad away in a manner proportional to the incident UV energy. Light absorbance increase at the rate of 1.1% per minute of irradiation was monitored. The exposure level at which the detector has linear response is comparable to the natural summer UV radiation. Evaluating the UV ability to pass through tissue equivalent gel materials shows that most of the UV gets absorbed in the first 5mm of the gel materials, which demonstrate the damaging effects of this radiation type on human skin and eyes. It was concluded that FXG gel dosimeter has the potential to offer a simple, passive ultraviolet radiation detector with sensitivity suitable to measure and visualises the natural sunlight UV exposure directly by watching the materials colour changes.

  14. UV radiation hazards

    International Nuclear Information System (INIS)

    Henderson, A.R.

    1987-01-01

    Exposure to ultraviolet radiation (UVR) is, for most people, a daily occurrence. Significant quantities of ultraviolet are present in sunlight, and this environmental exposure usually greatly exceeds that necessary for vitamin D production, the only certain benefit of UVR. In addition, occupational exposure to artificial sources of UVR is commonly encountered in commerce, industry and medicine. Exposure to UVR can present a hazard, principally to the eyes and exposed areas of the skin. The potential for any given source of UVR to cause photobiological damage depends on the spectral composition of the incident radiation, the geometry of optical coupling into the tissues at risk, the spectral sensitivity to damage of the irradiated tissue, the total accumulated exposure, and the action of any biological repair processes. In the ultraviolet region the photobiological interactions of concern are mainly photochemical. Hazard analysis and radiation protection require an appropriate framework of radiation measurement for the quantitative assessment of exposure and for the specification of safe exposure limits

  15. Familial melanoma associated with dominant ultraviolet radiation sensitivity

    International Nuclear Information System (INIS)

    Ramsay, R.G.; Chen, P.; Imray, F.P.; Kidson, C.; Lavin, M.F.; Hockey, A.

    1982-01-01

    Sensitivity to ultraviolet radiation was studied in lymphoblastoid cell lines derived from 32 members of two families with histories of multiple primary melanomas in several generations. As assayed by colony formation in agar or by trypan blue exclusion following irradiation, cellular sensitivity showed a bimodal distribution. All persons with melanoma or multiple moles were in the sensitive group, while some family members exhibited responses similar to those of controls. Cells from four cases of sporadic melanoma showed normal levels of sensitivity. The data are consistent with a dominantly inherited ultraviolet light sensitivity associated with these examples of familial melanoma. Spontaneous and ultraviolet light-induced sister chromatid exchange frequencies were similar to those in control cell lines. No defect in excision repair was detected in any of the above cell lines, but the sensitive group showed postirradiation inhibition of DNA replication intermediate between controls and an excision-deficient xeroderma pigmentosum cell line

  16. Determination of daily solar ultraviolet radiation using statistical models and artificial neural networks

    Directory of Open Access Journals (Sweden)

    F. J. Barbero

    2006-09-01

    Full Text Available In this study, two different methodologies are used to develop two models for estimating daily solar UV radiation. The first is based on traditional statistical techniques whereas the second is based on artificial neural network methods. Both models use daily solar global broadband radiation as the only measured input. The statistical model is derived from a relationship between the daily UV and the global clearness indices but modulated by the relative optical air mass. The inputs to the neural network model were determined from a large number of radiometric and atmospheric parameters using the automatic relevance determination method, although only the daily solar global irradiation, daily global clearness index and relative optical air mass were shown to be the optimal input variables. Both statistical and neural network models were developed using data measured at Almería (Spain, a semiarid and coastal climate, and tested against data from Table Mountain (Golden, CO, USA, a mountainous and dry environment. Results show that the statistical model performs adequately in both sites for all weather conditions, especially when only snow-free days at Golden were considered (RMSE=4.6%, MBE= –0.1%. The neural network based model provides the best overall estimates in the site where it has been trained, but presents an inadequate performance for the Golden site when snow-covered days are included (RMSE=6.5%, MBE= –3.0%. This result confirms that the neural network model does not adequately respond on those ranges of the input parameters which were not used for its development.

  17. Measurements of Solar Ultraviolet Radiation Exposure at Work and at Leisure in Danish Workers.

    Science.gov (United States)

    Grandahl, Kasper; Eriksen, Paul; Ibler, Kristina Sophie; Bonde, Jens Peter; Mortensen, Ole Steen

    2018-03-30

    Exposure to solar ultraviolet radiation is the main cause of skin cancer and may well present an occupational health and safety problem. In Denmark, skin cancer is a common disease in the general population, but detailed data on solar ultraviolet radiation exposure among outdoor workers are lacking. The aim of this study was to provide objective measurements of solar ultraviolet radiation exposure on working days and at leisure and compare levels of exposure between groups of mainly outdoor, equal-parts-outdoor-and-indoor and indoor workers. To this end, UV-B dosimeters with an aluminum gallium nitride (AlGaN) photodiode detector were used to measure the solar ultraviolet radiation exposure of 457 workers in the Danish summer season. Presented as semi-annual standard erythemal dose (SED) on working days, respectively, at leisure, the results are for mainly outdoor workers 214.2 SED and 64.8 SED, equal-parts-outdoor-and-indoor workers 131.4 SED and 64.8 SED, indoor workers 55.8 SED and 57.6 SED. The daily SED by month is significantly different (α = 0.05) between mainly outdoor, equal-parts-outdoor-and-indoor and indoor workers and across professional groups; some of which are exposed at very high levels that is roofers 361.8 SED. These findings substantiate that exposure to solar ultraviolet radiation is indeed an occupational health and safety problem in Denmark. © 2018 The Authors. Photochemistry and Photobiology published by Wiley Periodicals, Inc. on behalf of American Society for Photobiology.

  18. an assessment of ultraviolet radiation components of light emitted ...

    African Journals Online (AJOL)

    Dr

    therefore high for exposure limits of 8 hours for UV-B and UV-C and the 16 minutes for UV-A. The investigation ... has become particularly interesting as the ozone layer ... THEORY. Ultraviolet (UV) light is an electromagnetic radiation with a ...

  19. Health effects of exposure to ultraviolet and infrared radiation

    International Nuclear Information System (INIS)

    Thuerauf, J.R.

    1979-01-01

    A working group on the Health Effects of Exposure to Ultraviolet and Infrared Radiation met in Sofia (Bulgaria) from February 21-25, 1978. The conference was organized by the European Regional Bureau of the World Health Organization, WHO, in cooperation with the Bulgarian government. The main task for the participants was the revision and discussion of two guidelines. A Manual on Nonionizing Radiation Protection will be made available in 1979 to governmental and official organs to support them in establishing standards for the control of radiation. (orig.) [de

  20. Increased exposure of Southern Ocean phytoplankton to ultraviolet radiation

    Science.gov (United States)

    Lubin, Dan; Arrigo, Kevin R.; van Dijken, Gert L.

    2004-05-01

    Satellite remote sensing of both surface solar ultraviolet radiation (UVR) and chlorophyll over two decades shows that biologically significant ultraviolet radiation increases began to occur over the Southern Ocean three years before the ozone ``hole'' was discovered. Beginning in October 1983, the most frequent occurrences of enhanced UVR over phytoplankton-rich waters occurred in the Weddell Sea and Indian Ocean sectors of the Southern Ocean, impacting 60% of the surface biomass by the late 1990s. These results suggest two reasons why more serious impacts to the base of the marine food web may not have been detected by field experiments: (1) the onset of UVR increases several years before dedicated field work began may have impacted the most sensitive organisms long before such damage could be detected, and (2) most biological field work has so far not taken place in Antarctic waters most extensively subjected to enhanced UVR.

  1. Bystander effects in UV-induced genomic instability: Antioxidants inhibit delayed mutagenesis induced by ultraviolet A and B radiation

    Directory of Open Access Journals (Sweden)

    Dahle Jostein

    2005-01-01

    Full Text Available Abstract Background Genomic instability is characteristic of many types of human cancer. Recently, we reported that ultraviolet radiation induced elevated mutation rates and chromosomal instability for many cell generations after ultraviolet irradiation. The increased mutation rates of unstable cells may allow them to accumulate aberrations that subsequently lead to cancer. Ultraviolet A radiation, which primarily acts by oxidative stress, and ultraviolet B radiation, which initially acts by absorption in DNA and direct damage to DNA, both produced genomically unstable cell clones. In this study, we have determined the effect of antioxidants on induction of delayed mutations by ultraviolet radiation. Delayed mutations are indicative of genomic instability. Methods Delayed mutations in the hypoxanthine phosphoribosyl transferase (hprt gene were detected by incubating the cells in medium selectively killing hprt mutants for 8 days after irradiation, followed by a 5 day period in normal medium before determining mutation frequencies. Results The UVB-induced delayed hprt mutations were strongly inhibited by the antioxidants catalase, reduced glutathione and superoxide dismutase, while only reduced glutathione had a significant effect on UVA-induced delayed mutations. Treatment with antioxidants had only minor effects on early mutation frequenies, except that reduced glutathione decreased the UVB-induced early mutation frequency by 24 %. Incubation with reduced glutathione was shown to significantly increase the intracellular amount of reduced glutathione. Conclusion The strong effects of these antioxidants indicate that genomic instability, which is induced by the fundamentally different ultraviolet A and ultraviolet B radiation, is mediated by reactive oxygen species, including hydrogen peroxide and downstream products. However, cells take up neither catalase nor SOD, while incubation with glutathione resulted in increased intracellular levels of

  2. Effects of near ultraviolet and green radiations on plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R.M.; Edsall, P.C.; Gentile, A.C.

    1965-01-01

    Selective removal of near ultraviolet and green wavelengths from white light permitted enhanced growth of marigold, tomato, corn, and Impatiens plants, Chlamydomonas cells and the mycelium of Sordaria. Additions of near ultraviolet and green radiations caused repressions in the growth of marigold and Sordaria. These wavelengths do not alter the oxidative mechanisms of mitochondria, intact algal cells or marigold leaf tissues. The capacity for chlorophyll and carotenoid synthesis by Euglena cells was unaffected by these wavelengths. 23 references, 2 figures, 4 tables.

  3. Ultraviolet-B radiation effects on leaf fluorescence characteristics in cultivars of soybean

    International Nuclear Information System (INIS)

    Miles, D.

    1993-01-01

    Ultraviolet-B (UV-B; 280–320 nm)–emitting lamps unavoidably emit ultraviolet-A (UV-A; 320–400 nm) and ultraviolet-C (UV-C; <280 nm) radiation. Short-wavelength–blocking filters are generally used to limit the wave bands of UV under investigation. The widespread use of such filters means that all exposures to UV-B radiation will have a significant UV-A component. Therefore, the physiological effects unique to UV-B exposure are difficult to clearly isolate. This study presents a method to remove the UV-A and UV-C “contamination” using a liquid potassium chromate (K 2 CrO 4 ) filter, thus allowing more direct assessment of the effects of UV-B exposure. Cultures of the green marine alga Dunaliella tertiolecta were grown in the absence of UV radiation. Sunlamps supplied the UV radiation for a 24 h exposure (solar radiation was not used in this study). The UV radiation was filtered either by the standard method (i.e. cellulose acetate (CA) with polyester = Mylar controls) or by a liquid filter of potassium chromate. Photosynthetic responses were compared. Major decreases in the ratio of variable to maximal fluorescence in dark-adapted cells and photosynthetic capacity were observed in CA-filtered cultures, whereas no change was observed in cells exposed to the same UV-B flux with the UV-A removed by K 2 CrO 4 . The use of a CA filter with a Mylar control does not link results unequivocally to UV-B radiation. Such results should be interpreted with caution. (author)

  4. Effect of near-ultraviolet radiation on the cell surface of the protozoan Tritichomonas foetus

    International Nuclear Information System (INIS)

    Filho, F.C.S.; Elias, C.A.; Souza, W. de

    1982-01-01

    It is concluded that the authors' data showing that near-ultraviolet radiation decreases the cellular electrophoretic mobility of Tritrichomonas foetus indicate that ultraviolet radiation may have an important effect on basic properties of the plasma membrane such as (a) its surface charge, (b) the mobility of membrane-associated components, as revealed by the concanavalin A-induced agglutination, and (c) changes in its permeability to cytoplasmic components. These data also indicate that protozoa may be a useful model for studies related with the effect of radiation on eukaryotic cells. (author)

  5. Prediction of shock-layer ultraviolet radiation for hypersonic vehicles in near space

    Directory of Open Access Journals (Sweden)

    Niu Qinglin

    2016-10-01

    Full Text Available A systemic and validated model was developed to predict ultraviolet spectra features from the shock layer of near-space hypersonic vehicles in the “solar blind” band region. Computational procedures were performed with 7-species thermal non-equilibrium fluid mechanics, finite rate chemistry, and radiation calculations. The thermal non-equilibrium flow field was calculated with a two-temperature model by the finite volume technique and verified against the bow-shock ultra-violet (BSUV flight experiments. The absorption coefficient of the mixture gases was evaluated with a line-by-line method and validated through laboratory shock tube measurements. Using the line of sight (LOS method, radiation was calculated from three BSUV flights at altitudes of 38, 53.5 and 71 km. The investigation focused on the level and structure of ultraviolet spectra radiated from a NO band system in wavelengths of 200–400 nm. Results predicted by the current model show qualitative spatial agreement with the measured data. At a velocity of 3.5 km/s (about Mach 11, the peak absolute intensity at an altitude of 38 km is two orders of magnitude higher than that at 53.5 km. Under the same flight conditions, the spectra structures have quite a similar distribution at different viewing angles. The present computational model performs well in the prediction of the ultraviolet spectra emitted from the shock layer and will contribute to the investigation and analysis of radiative features of hypersonic vehicles in near space.

  6. Effects of Ultraviolet Radiation on Human Health (invited paper)

    International Nuclear Information System (INIS)

    MacKie, R.M.

    2000-01-01

    The detrimental and beneficial effects of exposure to ultraviolet radiation in the UVB and UVA ranges are discussed. The main benefit of UV radiation is promoting the synthesis of vitamin D from precursors in the skin. Detrimental effects include acute sun damage in the form of sunburn and chronic sun damage leading to photoageing and possibly to cutaneous malignancies. Other detrimental effects of UV exposure include photosensitivity reactions to ingested drugs and rare examples of genetically determined photosensitivies. (author)

  7. Effects of Ultraviolet Radiation on Human Health (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    MacKie, R.M

    2000-07-01

    The detrimental and beneficial effects of exposure to ultraviolet radiation in the UVB and UVA ranges are discussed. The main benefit of UV radiation is promoting the synthesis of vitamin D from precursors in the skin. Detrimental effects include acute sun damage in the form of sunburn and chronic sun damage leading to photoageing and possibly to cutaneous malignancies. Other detrimental effects of UV exposure include photosensitivity reactions to ingested drugs and rare examples of genetically determined photosensitivies. (author)

  8. A spectroscopic study on the effect of ultra-violet solar radiation in Antarctica on the human skin fibroblast cells

    Directory of Open Access Journals (Sweden)

    Tatsuyuki Yamamoto

    2013-11-01

    Full Text Available A study on the effect of the solar ultra-violet radiation on the human skin fibroblast cells revealed that the production of matrix metalloproteinase-2 was inhibited by the radiation. A CO2 incubator connected by optical fibers to a reflector telescope for collecting the solar light was built at Syowa station by the 49th Japanese Antarctica Research Expedition. The direction of the telescope was continuously controlled by a sun-tracker to follow the movement of the Sun automatically. The intensity of the collected light was monitored by a portable spectrophotometer housed inside. The human skin fibroblast cells were incubated in the CO2 chamber to investigate the effect of the solar radiation at Syowa station and were compared with those reference experiments at a laboratory in Japan. The results showed cell damage by strong UV radiation. The production of matrix metalloproteinase-2 was prompted by the moderate UV-B, but was inhibited by the strong UV-B radiation, as studied under laboratory conditions in Japan. The effect of strong solar radiation at Syowa station involving the radiation of UV-B region was estimated to be of the same extent of the radiation caused by an artificial UV-B light with the intensity more than 50 mJ/cm2.

  9. Solar Activity, Ultraviolet Radiation and Consequences in Birds in Mexico City, 2001- 2002

    Science.gov (United States)

    Valdes, M.; Velasco, V.

    2008-12-01

    Anomalous behavior in commercial and pet birds in Mexico City was reported during 2002 by veterinarians at the Universidad Nacional Autonoma de Mexico. This was attributed to variations in the surrounding luminosity. The solar components, direct, diffuse, global, ultraviolet band A and B, as well as some meteorological parameters, temperature, relative humidity, and precipitation, were then analyzed at the Solar Radiation Laboratory. Although the total annual radiance of the previously mentioned radiation components did not show important changes, ultraviolet Band-B solar radiation did vary significantly. During 2001 the total annual irradiance , 61.05 Hjcm² to 58.32 Hjcm², was 1.6 standard deviations lower than one year later, in 2002 and increased above the mean total annual irradiance, to 65.75 Hjcm², 2.04 standard deviations, giving a total of 3.73 standard deviations for 2001-2002. Since these differences did not show up clearly in the other solar radiation components, daily extra-atmosphere irradiance was analyzed and used to calculate the total annual extra-atmosphere irradiance, which showed a descent for 2001. Our conclusions imply that Ultraviolet Band-B solar radiation is representative of solar activity and has an important impact on commercial activity related with birds.

  10. Red tattoos, ultraviolet radiation and skin cancer in mice

    DEFF Research Database (Denmark)

    Lerche, Catharina M.; Heerfordt, Ida M.; Serup, Jørgen

    2017-01-01

    Ultraviolet radiation (UVR) induces skin cancer. The combination of UVR and red tattoos may be associated with increased risk of skin cancer due to potential carcinogens in tattoo inks. This combination has not been studied previously. Immunocompetent C3.Cg/TifBomTac hairless mice (n=99) were...

  11. Ocular ultraviolet radiation exposure of welders.

    Science.gov (United States)

    Tenkate, Thomas D

    2017-05-01

    workers in a welding environment. Am Indust Hyg Assoc J. 1997;58:33-8. https://doi.org/10.1080/15428119791013053.  4. ACGIH. Ultraviolet radiation in: TLVs and BEIs. American Conference of Governmental Industrial Hygienists. Cincinnati; 2016. p. 153-8.  5. Tenkate TSD and Collins MJ. Angles of entry of ultraviolet radiation into welding helmets. Am Indust Hyg Assoc J, 1997; 58:54-6. https://doi.org/10.1080/15428119791013099.  6. Tenkate T. Welding arc time and UV exposure: implications for worker safety. J Occup Health Safety-Aust NZ. 2008;24(2):161-6.  7. ANSI Z49.1:2012. Safety in Welding, Cutting, and Allied Processes. American Welding Society: Miami; 2012.  8. Lombardi DA, Verma SK, Brennan MJ, Perry MJ. Factors influencing worker use of personal protective eyewear. Accident Analysis and Prevention. 2009;41:755-62. https://doi.org/10.1016/j.aap.2009.03.017.  9. Tenkate TD. Optical radiation hazards of welding arcs. Rev Environ Health. 1998;13(3):131-46. https://doi.org/10.1515/REVEH.1998.13.3.131.  10. Thieden E, Philipsen PA, Heydenreich J, Wulf HC. UV radiation exposure related to age, sex, occupation, and sun behavior based on time-stamped personal dosimeter readings. Arch Dermatol. 2004;140:197-203. https://doi.org/10.1001/archderm.140.2.197.  11. Gourzoulidis GA, Achtipis A, Topalis FV, Kazasidis ME, Pantelis D, Markoulis A. Artificial optical radiation photobiological hazards in arc welding. Physica Medica. 2016;32:981-6. https://doi.org/10.1016/j.ejmp.2016.07.001.  12. Mariutti G, Matzeu M. Measurement of ultraviolet radiation emitted from welding arcs. Health Physics. 1988;54(5):529-32. https://doi.org/10.1097/00004032-198805000-00004.  13. Okuno T. Measurement of ultraviolet radiation from welding arcs. Industrial Health. 1987; 25:147-56. https://doi.org/10.2486/indhealth.25.147. 14. Zlateva V, Toncheva R, Andreev A. Epidemiological studies on occupational eye pathology. Eur. J. Ophthalmol. 1996;6(4):440-5.  15. Lombardi DA, Pannala R, Sorock GS

  12. Effect of ultraviolet-B radiation on biochemical and antioxidant ...

    African Journals Online (AJOL)

    user

    The stratospheric ozone depletion and enhanced solar ultraviolet-B (UV-B) ... mechanism produced by enzymatic antioxidant such as catalase, peroxidase, ... absorb UV-B and prevent it from penetrating into the leaf mosophyll cells. The aim of this work was to investigate the effects of UV-B radiation on Indigofera tinctoria ...

  13. Risk from exposure to natural and artificial ultraviolet radiation; Il rischio di esposizione alla radiazione ultravioletta naturale e artificiale

    Energy Technology Data Exchange (ETDEWEB)

    Matzeu, M. [Istituto Superiore di Sanita`, Rome (Italy). Lab. di Fisica

    1998-12-31

    The association between exposure to ultraviolet (UV) and damage to the skin and eyes is today generally accepted. Exposure to UV radiation may occur in several ways. Apart from the sun, there is a wide range of artificial sources used in different fields of industry, research and medicine, the exposure to which adds to the total exposure of an individual during his life-span. The potential effects of ozone layer depletion on the increase of the solar UV radiation at earth`s surface, and therefor on human health, have recently been emphasized. Moreover, great attention has been devoted to the often uncontrolled use of UV lamps for tanning. This report shows the basis on which short and long term UV risk is assessed, and indicates some parameters necessary to its evaluation. The UV effects, both at molecular and cellular levels and on humans, are described together with their respective action spectra. The most common UV sources are then analyzed and their use in different fields is shown. Finally, some methods in dosimetry, which are useful for the correct measurement of exposure values, are described. [Italiano] E` oggi generalmente accettata l`assciazione tra l`esposizione alla radiazione UV e alcuni danni alla pelle e agli occhi (carcinomi e cataratta). Le occasioni di esposizione sono molteplici; oltre al sole, anche una grande varieta` di sorgenti artificiali impiegate per scopi diversi nell`industria, nella ricerca e in medicina danno un contributo, non sempre valutabile, all`esposizione totale di un individuo nell`arco della sua vita. Recentemente e` stato posto l`accento sulle possibili conseguenze della riduzione dello stato di ozono stratosferico sull`aumento della frazione di UV solare al suolo e quindi sulla salute umana; particolare attenzione ha inoltre suscitato l`uso, spesso incontrollato, delle lampade UV per scopi estetici. Sono illustrate le basi sulle quali viene riconosciuto il rischio a breve e a lungo termine e sono definiti i parametri

  14. Risk from exposure to natural and artificial ultraviolet radiation; Il rischio di esposizione alla radiazione ultravioletta naturale e artificiale

    Energy Technology Data Exchange (ETDEWEB)

    Matzeu, M [Istituto Superiore di Sanita` , Rome (Italy). Lab. di Fisica

    1999-12-31

    The association between exposure to ultraviolet (UV) and damage to the skin and eyes is today generally accepted. Exposure to UV radiation may occur in several ways. Apart from the sun, there is a wide range of artificial sources used in different fields of industry, research and medicine, the exposure to which adds to the total exposure of an individual during his life-span. The potential effects of ozone layer depletion on the increase of the solar UV radiation at earth`s surface, and therefor on human health, have recently been emphasized. Moreover, great attention has been devoted to the often uncontrolled use of UV lamps for tanning. This report shows the basis on which short and long term UV risk is assessed, and indicates some parameters necessary to its evaluation. The UV effects, both at molecular and cellular levels and on humans, are described together with their respective action spectra. The most common UV sources are then analyzed and their use in different fields is shown. Finally, some methods in dosimetry, which are useful for the correct measurement of exposure values, are described. [Italiano] E` oggi generalmente accettata l`assciazione tra l`esposizione alla radiazione UV e alcuni danni alla pelle e agli occhi (carcinomi e cataratta). Le occasioni di esposizione sono molteplici; oltre al sole, anche una grande varieta` di sorgenti artificiali impiegate per scopi diversi nell`industria, nella ricerca e in medicina danno un contributo, non sempre valutabile, all`esposizione totale di un individuo nell`arco della sua vita. Recentemente e` stato posto l`accento sulle possibili conseguenze della riduzione dello stato di ozono stratosferico sull`aumento della frazione di UV solare al suolo e quindi sulla salute umana; particolare attenzione ha inoltre suscitato l`uso, spesso incontrollato, delle lampade UV per scopi estetici. Sono illustrate le basi sulle quali viene riconosciuto il rischio a breve e a lungo termine e sono definiti i parametri

  15. Additive effects of ultraviolet radiation

    International Nuclear Information System (INIS)

    Cullen, A.P.

    1980-01-01

    A xenon-mercury high pressure lamp and a double monochromator were used to produce ultraviolet (uv) radiation at 295 nm. Pigmented rabbit eyes were irradiated and evaluated by slitlamp biomicroscopy. Corneal threshold (Hc) was 0.05 J.cm-2 and lens threshold (hL) was 0.75 J.cm-2. Other eyes were irradiated with 2 Hc and evaluated from 4 to 24 h at 4 h intervals. Corneal damage was only greater than that expected from a single Hc exposure if the separation between the two Hc exposures did not exceed 8 h. The most repeatable and reliable corneal response to these levels of uv was the development of corneal epithelial granules

  16. Interventions to prevent skin cancer by reducing exposure to ultraviolet radiation: a systematic review.

    Science.gov (United States)

    Saraiya, Mona; Glanz, Karen; Briss, Peter A; Nichols, Phyllis; White, Cornelia; Das, Debjani; Smith, S Jay; Tannor, Bernice; Hutchinson, Angela B; Wilson, Katherine M; Gandhi, Nisha; Lee, Nancy C; Rimer, Barbara; Coates, Ralph C; Kerner, Jon F; Hiatt, Robert A; Buffler, Patricia; Rochester, Phyllis

    2004-12-01

    The relationship between skin cancer and ultraviolet radiation is well established. Behaviors such as seeking shade, avoiding sun exposure during peak hours of radiation, wearing protective clothing, or some combination of these behaviors can provide protection. Sunscreen use alone is not considered an adequate protection against ultraviolet radiation. This report presents the results of systematic reviews of effectiveness, applicability, other harms or benefits, economic evaluations, and barriers to use of selected interventions to prevent skin cancer by reducing exposure to ultraviolet radiation. The Task Force on Community Preventive Services found that education and policy approaches to increasing sun-protective behaviors were effective when implemented in primary schools and in recreational or tourism settings, but found insufficient evidence to determine effectiveness when implemented in other settings, such as child care centers, secondary schools and colleges, and occupational settings. They also found insufficient evidence to determine the effectiveness of interventions oriented to healthcare settings and providers, media campaigns alone, interventions oriented to parents or caregivers of children, and community-wide multicomponent interventions. The report also provides suggestions for areas for future research.

  17. Measurement of solar ultraviolet radiation intensity type A and B in Qazvin (2013-14

    Directory of Open Access Journals (Sweden)

    SAR. Babaee

    2016-08-01

    Full Text Available Background: Solar ultraviolet radiation (UVR is considered one of the most important biological risk factors in the world. Most health damages from solar ultraviolet radiation at ground level are mainly caused by UVA and UVB spectrums. Objective: The aim of this study was to Measure the solar ultraviolet radiation intensity type A and B in Qazvin city. Methods: In this cross-sectional study, the intensity of solar ultraviolet radiation type A and B was measured in Qazvin on years of 2013-14 (during one year every monthly at three times, in the morning, afternoon and evening by using a UV Radiometer. Data were analyzed using descriptive statistics. Findings: The maximum average intensity of UVA and UVB rays during the one year with 28.36±1.88 W/m2 and 0.156±0.035 W/m2 respectively was in Tir month (June 22–July 22 and the minimum average intensity of UVA and UVB rays with 10.36±0.83 W/m2 and 0.041±0.010 W/m2 respectively was in Dai month (December 22–January 20. Conclusion: With regards to the results, it is recommended that individuals were less exposed to exposure time with direct sunshine and use appropriate protective measures such as; wear appropriate clothing, sunglasses, and sunscreen.

  18. Melanocortin 1 receptor genotype: an important determinant of the damage response of melanocytes to ultraviolet radiation

    Science.gov (United States)

    Kadekaro, Ana Luisa; Leachman, Sancy; Kavanagh, Renny J.; Swope, Viki; Cassidy, Pamela; Supp, Dorothy; Sartor, Maureen; Schwemberger, Sandy; Babcock, George; Wakamatsu, Kazumasa; Ito, Shosuke; Koshoffer, Amy; Boissy, Raymond E.; Manga, Prashiela; Sturm, Richard A.; Abdel-Malek, Zalfa A.

    2010-01-01

    The melanocortin 1 receptor gene is a main determinant of human pigmentation, and a melanoma susceptibility gene, because its variants that are strongly associated with red hair color increase melanoma risk. To test experimentally the association between melanocortin 1 receptor genotype and melanoma susceptibility, we compared the responses of primary human melanocyte cultures naturally expressing different melanocortin 1 receptor variants to α-melanocortin and ultraviolet radiation. We found that expression of 2 red hair variants abolished the response to α-melanocortin and its photoprotective effects, evidenced by lack of functional coupling of the receptor, and absence of reduction in ultraviolet radiation-induced hydrogen peroxide generation or enhancement of repair of DNA photoproducts, respectively. These variants had different heterozygous effects on receptor function. Microarray data confirmed the observed differences in responses of melanocytes with functional vs. nonfunctional receptor to α-melanocortin and ultraviolet radiation, and identified DNA repair and antioxidant genes that are modulated by α-melanocortin. Our findings highlight the molecular mechanisms by which the melanocortin 1 receptor genotype controls genomic stability of and the mutagenic effect of ultraviolet radiation on human melanocytes.—Kadekaro, A. L., Leachman, S., Kavanagh, R. J., Swope, V., Cassidy, P., Supp, D., Sartor, M., Schwemberger, S., Babcock, G., Wakamatsu, K., Ito, S., Koshoffer, A., Boissy, R. E., Manga, P., Sturm, R. A., Abdel-Malek, Z. A. Melanocortin 1 receptor genotype: an important determinant of the damage response of melanocytes to ultraviolet radiation. PMID:20519635

  19. Improving Assessment of Lifetime Solar Ultraviolet Radiation Exposure in Epidemiologic Studies: Comparison of Ultraviolet Exposure Assessment Methods in a Nationwide United States Occupational Cohort.

    Science.gov (United States)

    Little, Mark P; Tatalovich, Zaria; Linet, Martha S; Fang, Michelle; Kendall, Gerald M; Kimlin, Michael G

    2018-06-13

    Solar ultraviolet radiation is the primary risk factor for skin cancers and sun-related eye disorders. Estimates of individual ambient ultraviolet irradiance derived from ground-based solar measurements and from satellite measurements have rarely been compared. Using self-reported residential history from 67,189 persons in a nationwide occupational US radiologic technologists cohort, we estimated ambient solar irradiance using data from ground-based meters and noontime satellite measurements. The mean distance-moved from city of longest residence in childhood increased from 137.6 km at ages 13-19 to 870.3 km at ages ≥65, with corresponding increases in absolute latitude-difference moved. At ages 20/40/60/80, the Pearson/Spearman correlation coefficients of ground-based and satellite-derived solar potential ultraviolet exposure, using irradiance and cumulative radiant-exposure metrics, were high (=0.87-0.92). There was also moderate correlation (Pearson/Spearman correlation coefficients=0.51-0.60) between irradiance at birth and at last-known address, for ground-based and satellite data. Satellite-based lifetime estimates of ultraviolet radiation were generally 14-15% lower than ground-based estimates, albeit with substantial uncertainties, possibly because ground-based estimates incorporate fluctuations in cloud and ozone, which are incompletely incorporated in the single noontime satellite-overpass ultraviolet value. If confirmed elsewhere, the findings suggest that ground-based estimates may improve exposure-assessment accuracy and potentially provide new insights into ultraviolet-radiation-disease relationships in epidemiologic studies. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Effects of antibiotics and ultraviolet radiation on the halophilic blue-green alga

    International Nuclear Information System (INIS)

    Yopp, J.H.; Albright, G.; Miller, D.M.; Southern Illinois Univ., Carbondale

    1979-01-01

    The effects of a variety of antibiotics, ultraviolet radiation and N-methyl-N-nitro-N-nitro-N-nitrosoguanidine (NTG) on the survival and mutability of the halophilic blue-green alga, Aphanothece halophytica, were determined. The halophile was found extremely sensitive to penicillin G and bacitracin; moderately sensitive to novobiocin, amino acid analogs, chloramphenicol and streptomycin; and tolerant to actidione and hydroxyurea. Ultraviolet and NTG killing curves and photoreactivation capabilities were seimilar to those reported for other members of the Chroococcales. Three stable morphological mutants were obtained by ultraviolet and NTG treatment, the latter being much more efficient in the production of mutants. (orig.)

  1. Channel catfish response to ultraviolet-B radiation

    Science.gov (United States)

    Ewing, M.S.; Blazer, V.S.; Fabacher, D.L.; Little, E.E.; Kocan, K.M.

    1999-01-01

    Fingerling channel catfish Ictalurus punctatus exposed to simulated ultraviolet-B radiation at an average daily dose of 2.9 J/cm2 were quite sensitive to the radiation. After a 24-h exposure, thinning of the most dorsal epidermis frequently was accompanied by edema. Compared with epidermis of unexposed fish, mucous cells in exposed fish were less superficial and club cells were less numerous both dorsally and high on the lateral surface of the body. Sunburn cells with pyknotic nuclei were evident in the epidermis of exposed fish. Among fish exposed for 48 h, focal necrosis and sloughing of the outer epidermal layer were widespread. A methanol-extractable skin substance that is associated with resistance to sunburn in other fish species was not detected in channel catfish.

  2. Effect of ultraviolet radiation absorbing film on pollination work of foreign bumblebee [Bombus terrestris

    International Nuclear Information System (INIS)

    Nishiguchi, I.

    1999-01-01

    The transmitted light through the ultraviolet radiation absorbing (UVA) film has a preventing effect of disease and pest occurrence. To develop the agriculture harmonized with the ecosystem, we attempted to research a further possible utilization of the UVA film. Pollination work of foreign bumblebee (Bombus terrestris) in the greenhouses roofed with UVA film and with common film for agriculture was examined in growing fruit-vegetables. The bumblebees used were not acclimatized to environmental conditions of the greenhouses. They visited flowers and gathered pollen from flowered crops grown in both houses, irrespective of the kind of film covering over the greenhouse roof, and the pollen quantity gathered was far greater in crops which produced in large quantity of pollen. Thus, the bumblebees were capable to work under the condition lacking in ultraviolet radiation. This pollinating behavior is different from that of honeybees. Then we concluded that bumblebees functioned well as an efficient pollinator under the condition without ultraviolet radiation

  3. A study of ultraviolet solar radiation at Cairo urban area, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Robaa, S.M. [Cairo Univ., Giza (Egypt). Dept. of Astronomy and Meterology

    2004-07-01

    The monthly mean values of global, G, and ultraviolet, UV, solar radiation incident on a horizontal surface at Cairo urban area during the two different periods (1969-1973) and (1993-1997) are presented, analyzed and compared. The effect of urbanization processes on the solar radiation components is investigated and discussed. It was found that the total radiation of the two components, G and UV received at the urban area of Cairo during the period (1969-1973) highly exceeds the radiation received during the period (1993-1997) for all months of the year. The mean relative reduction of G and UV reached 17.4% and 27.4% respectively. A significant correlation between G and UV radiation has been established and the recommended correlation equation has been stated to estimate the values of UV radiation that are difficult to measure at any site in the zone of Lower Egypt. Also, a comparative study of the two radiation components, G and UV, at urban (Cairo) and rural (Bahtim) areas during the period (1993-1997) revealed that the urban area always has values of G and UV radiation distinctly lower than that found in rural area for all months of the year. Urban-rural mean reduction of G and UV reached 7.0% and 17.9% respectively. The ratio of the ultraviolet to global radiation (UV/G) are calculated and compared with other sites in the Arabian Peninsula. The effect of atmospheric dust on the measured solar radiation components is also investigated and discussed. (author)

  4. Phototherapy cabinet for ultraviolet radiation therapy

    International Nuclear Information System (INIS)

    Horwitz, S.N.; Frost, P.

    1981-01-01

    A newly designed cabinet can be used for the treatment of psoriasis with fluorescent ultraviolet (UV) lamps. the new design provides more uniform distribution of UV radiation in both the horizontal and vertical axes, and several safety features have been added. The distribution and uniformity of UV output in this and in a previously described cabinet are compared. The UV output at the vertical center of the older UV light cabinet was six times greater than that at either the top or bottom, while the design of the present cabinet provides uniform UV radiation except for a slight increase at head height and at the level of the lower legs compared with the middle third of the cabinet. The variation in output of the older cabinet may, in part, explain the commonly encountered difficulty in the phototherapy of psoriasis of the scalp and lower extremities

  5. Sterilization techniques without heating (ultraviolet ray, radiation and ozone)

    International Nuclear Information System (INIS)

    Ito, Hitoshi

    1991-01-01

    The recent demand of consumers for processed foods is characterized by the intention for health and nature, besides, the demand for low sweetness, salt reduction, no additive and freshness becomes strong. In view of the control of microorganisms in products, all these become the negative factors. Accordingly, in order to overcome them, it is urgently desired to develop new technology or to improve conventional methods. As to heating sterilization, the uniform temperature treatment to the inside of foods is difficult, and it cannot be applied to perishables. The high temperature sterilization above 120degC causes the change in nutrition composition and physical properties. Ultraviolet ray and ozone can be used for the sterilization of food surface and powder and liquid foods. Radiation treatment can be applied to packed foods and frozen foods as well as food surface. The principle and the fields of application of ultraviolet ray sterilization, radiation sterilization and ozone sterilization are reported. In the mechanism of these methods, the action to DNA and oxidation are common. (K.I.)

  6. Ultraviolet radiation-induced carcinogenesis: mechanisms and experimental models

    International Nuclear Information System (INIS)

    Ramasamy, Karthikeyan; Shanmugam, Mohana; Balupillai, Agilan; Govindhasamy, Kanimozhi; Gunaseelan, Srithar; Muthusamy, Ganesan; Robert, Beualah Mary; Nagarajan, Rajendra Prasad

    2017-01-01

    Ultraviolet radiation (UVR) is a very prominent environmental toxic agent. UVR has been implicated in the initiation and progression of photocarcinogenesis. UVR exposure elicits numerous cellular and molecular events which include the generation of inflammatory mediators, DNA damage, epigenetic modifications, and oxidative damages mediated activation of signaling pathways. UVR-initiated signal transduction pathways are believed to be responsible for tumor promotion effects. UVR-induced carcinogenic mechanism has been well studied using various animal and cellular models. Human skin-derived dermal fibroblasts, epidermal keratinocytes, and melanocytes served as excellent cellular model systems for the understanding of UVR-mediated carcinogenic events. Apart from this, scientists developed reconstituted three-dimensional normal human skin equivalent models for the study of UVR signaling pathways. Moreover, hairless mice such as SKH-1, devoid of Hr gene, served as a valuable model for experimental carcinogenesis. Scientists have also used transgenic mice and dorsal portion shaved Swiss albino mice for UVR carcinogenesis studies. In this review, we have discussed the current progress in the study on ultraviolet B (UVB)-mediated carcinogenesis and outlined appropriate experimental models for both ultraviolet A- and UVB-mediated carcinogenesis. (author)

  7. Biological Effects of Sunlight, Ultraviolet Radiation, Visible Light, Infrared Radiation and Vitamin D for Health.

    Science.gov (United States)

    Holick, Michael F

    2016-03-01

    Humans evolved in sunlight and had depended on sunlight for its life giving properties that was appreciated by our early ancestors. However, for more than 40 years the lay press and various medical and dermatology associations have denounced sun exposure because of its association with increased risk for skin cancer. The goal of this review is to put into perspective the many health benefits that have been associated with exposure to sunlight, ultraviolet A (UVA) ultraviolet B (UVB), visible and infrared radiation. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  8. Occupational standard for exposure to ultraviolet radiation (1989)

    International Nuclear Information System (INIS)

    1989-12-01

    The exposure limit (EL) values in this standard refer to ultraviolet radiation (UVR) in the spectral region between 180 and 400 nm and represents conditions under which it is believed that nearly all workers may be repeatedly exposed without adverse effect. The EL values for exposure of the eye or the skin may be used to evaluate potentially hazardous exposure from UVR. The limits do not apply to ultraviolet lasers. The values should be used as guides in the control of exposure to both pulsed and continuous sources of UVR where the exposure duration is not less than 0.1 μsec. The ELs are below levels used for UV exposures of patients as a part of medical treatment or for elective cosmetic purposes. They are intended as upper limits for non therapeutic and non cosmetic exposure. 2 refs., 2 tabs

  9. Biological effect of ultraviolet radiation on cattle: bovine ocular squamous cell carcinoma

    International Nuclear Information System (INIS)

    Kopecky, K.E.; Pugh, G.W. Jr.; Hughes, D.E.; Booth, G.D.; Cheville, N.F.

    1979-01-01

    The relationship between bovine ocular squamous cell carcinoma and ultraviolet radiation was studied. Experimental procedures were devised to irradiate cattle with predetermined quantities of ultraviolet beta. Irradiation induced a preneoplastic ocular growth in one of four irradiated cattle. An epizootiologic study indicates that since 1950 the occurrence of bovine ocular squamous cell carcinoma reported at slaughter has increased. This increase was real and not due to an increase in numbers of cattle

  10. Ultraviolet light and infrared radiation. Measurement and hazard assessment

    International Nuclear Information System (INIS)

    Mayer, A.; Salsi, S.

    1979-01-01

    Ultraviolet, light and infrared radiation exists in many work places and can be dangerous in many ways, especially for the eyes. The INRS has developed a method and an apparatus for measuring on site or in a laboratory the spectral energy distribution of such radiation and the luminance of the source. With current knowledge of the effects of radiation on the eyes and by comparing readings taken and recommended limit values, it is possible to determine the risk levels at work places in the different wave ranges. Two examples of readings taken at a pot furnace in a crystal glass factory and at an MAG welding station are given and the appropriate protective measures described [fr

  11. The Relationship between Ultraviolet Radiation Exposure and Vitamin D Status

    Directory of Open Access Journals (Sweden)

    Ola Engelsen

    2010-05-01

    Full Text Available This paper reviews the main factors influencing the synthesis of vitamin D, with particular focus on ultraviolet radiation exposure. On the global level, the main source of vitamin D is the sun. The effect of solar radiation on vitamin D synthesis depends to some extent on the initial vitamin D levels. At moderate to high latitudes, diet becomes an increasingly important source of vitamin D due to decreased solar intensity and cold temperatures, which discourage skin exposure. During the mid-winter season, these factors result in decreased solar radiation exposure, hindering extensively the synthesis of vitamin D in these populations.

  12. Ocean acidification alters the photosynthetic responses of a coccolithophorid to fluctuating ultraviolet and visible radiation.

    Science.gov (United States)

    Jin, Peng; Gao, Kunshan; Villafañe, Virginia E; Campbell, Douglas A; Helbling, E Walter

    2013-08-01

    Mixing of seawater subjects phytoplankton to fluctuations in photosynthetically active radiation (400-700 nm) and ultraviolet radiation (UVR; 280-400 nm). These irradiance fluctuations are now superimposed upon ocean acidification and thinning of the upper mixing layer through stratification, which alters mixing regimes. Therefore, we examined the photosynthetic carbon fixation and photochemical performance of a coccolithophore, Gephyrocapsa oceanica, grown under high, future (1,000 μatm) and low, current (390 μatm) CO₂ levels, under regimes of fluctuating irradiances with or without UVR. Under both CO₂ levels, fluctuating irradiances, as compared with constant irradiance, led to lower nonphotochemical quenching and less UVR-induced inhibition of carbon fixation and photosystem II electron transport. The cells grown under high CO₂ showed a lower photosynthetic carbon fixation rate but lower nonphotochemical quenching and less ultraviolet B (280-315 nm)-induced inhibition. Ultraviolet A (315-400 nm) led to less enhancement of the photosynthetic carbon fixation in the high-CO₂-grown cells under fluctuating irradiance. Our data suggest that ocean acidification and fast mixing or fluctuation of solar radiation will act synergistically to lower carbon fixation by G. oceanica, although ocean acidification may decrease ultraviolet B-related photochemical inhibition.

  13. DNA replication and repair in Tilapia cells. 1. The effect of ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yew, F.H.; Chang, L.M. (National Taiwan Univ., Taipei (China))

    1984-12-01

    The effect of ultraviolet radiation on a cell line established from the warm water fish Tilapia has been assessed by measuring the rate of DNA synthesis, excision repair, post-replication repair and cell survival. The cells tolerate ultraviolet radiation better than mammalian cells with respect to DNA synthesis, post-replication repair and cell survival. They are also efficient in excision repair, which in other fish cell lines has been found to be at a low level or absent. Their response to the inhibitors hydroxyurea and 1-..beta..-D-arabinofuranosylcytosine is less sensitive than that of other cell lines, yet the cells seem to have very small pools of DNA precursor.

  14. Tl response of KMgF3: Lu + PTFE at ultraviolet radiation

    International Nuclear Information System (INIS)

    Gonzalez, P.R.; Alarcon, N.G.; Furetta, C.; Azorin, J.

    2003-01-01

    Ionizing radiation has different types of interaction with a crystalline solid. However, only few effects are interesting to optimize some thermoluminescent (Tl) properties of certain Tl materials. This paper presents results obtained by irradiating KMgF 3 : Lu + Ptfe Tl dosimeters with ultraviolet (UV) radiation previously exposed to gamma radiation. These results showed that those dosimeters not exposed previously to gamma radiation did not presented any Tl signal. Meanwhile, those previously submitted to gamma irradiation showed that their sensitivity was increased as the gamma dose increased. The glow curve of sensitized KMgF 3 : Lu + Ptfe exposed to UV radiation, presented the dosimetric pea at 212 C. This makes this material to be promissory for measuring UV radiation. (Author)

  15. Measurement of the solar ultraviolet radiation at ground level in Bangi, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Aljawi, Ohoud; Gopir, Geri; Duay, Abdul Basit [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia. ohoud-aljawi@hotmail.com (Malaysia)

    2015-04-24

    Understanding the amount of ultraviolet (UV) radiation received by human, plant, and animal organisms near the earth’s surface is important to a wide range of fields such as cancer research, agriculture and forestry. The solar ultraviolet spectral irradiance at ground level was measured using the Avantes spectrometer for the period of January to March 2014 at Bangi (2°55´N, 101°46´E, 50 m above sea level) in Malaysia. These data were used to estimate the diurnal variation of UV irradiance (300 – 400 nm). The maximum irradiance of UV radiation was 45 W m{sup −2} on horizontal surface. The maximum irradiance of UV received in the local noon time, and the minimum values of UV irradiance was received in the local morning time. It is found a bigger value of UV radiation was observed on clear sky in January. The estimation of daily flux average of UV irradiance was (921± 91) kJ m{sup −2}.

  16. An initial assessment of the impact of Australian aerosols on surface ultraviolet radiation and implications for human health

    International Nuclear Information System (INIS)

    Chee, C Y; Mills, F P

    2010-01-01

    Aerosols can have significant influence on surface radiation, and the intense surface ultraviolet radiation Australia experiences contributes to Australia's high incidence rates for related human diseases. Aerosol properties, such as total column aerosol optical depth, have been measured over several years for varying lengths of time at sites across Australia using sunphotometers. Statistical analysis of the average daily aerosol optical depth over sites near Alice Springs, Canberra, Darwin, and Perth provides one measure of the annual atmospheric loading of aerosols over these sites. The sunphotometers used at these sites do not make measurements in the UV-B spectral region and have only one channel in the UV-A spectral region, the regions of most interest for assessing human health impact. Consequently, model calculations using standard aerosol types have been used to make an initial estimate of the impact of the aerosols found over these four sites on surface ultraviolet radiation. The aerosol loading is at times sufficient to significantly reduce the surface ultraviolet radiation, but few such days occur each year. The annual average effect of aerosols on surface ultraviolet radiation, thus, appears to be small compared to lifestyle factors, such as clothing and use of sunscreen.

  17. SIMULATED SOLAR ULTRAVIOLET RADIATION EFFECTS ON 5 SPECIES OF SCLERACTINIAN CORALS

    Science.gov (United States)

    The impact of global climate change factors such as increased temperature and ultraviolet radiation (UVR) on coral bleaching are of continued interest to the USEPA. Coral bleaching occurs when symbiotic zooxanthellae and/or their pigments are depleted in response to stressors suc...

  18. Ultraviolet Radiations: Skin Defense-Damage Mechanism.

    Science.gov (United States)

    Mohania, Dheeraj; Chandel, Shikha; Kumar, Parveen; Verma, Vivek; Digvijay, Kumar; Tripathi, Deepika; Choudhury, Khushboo; Mitten, Sandeep Kumar; Shah, Dilip

    2017-01-01

    UV-radiations are the invisible part of light spectra having a wavelength between visible rays and X-rays. Based on wavelength, UV rays are subdivided into UV-A (320-400 nm), UV-B (280-320 nm) and UV-C (200-280 nm). Ultraviolet rays can have both harmful and beneficial effects. UV-C has the property of ionization thus acting as a strong mutagen, which can cause immune-mediated disease and cancer in adverse cases. Numbers of genetic factors have been identified in human involved in inducing skin cancer from UV-radiations. Certain heredity diseases have been found susceptible to UV-induced skin cancer. UV radiations activate the cutaneous immune system, which led to an inflammatory response by different mechanisms. The first line of defense mechanism against UV radiation is melanin (an epidermal pigment), and UV absorbing pigment of skin, which dissipate UV radiation as heat. Cell surface death receptor (e.g. Fas) of keratinocytes responds to UV-induced injury and elicits apoptosis to avoid malignant transformation. In addition to the formation of photo-dimers in the genome, UV also can induce mutation by generating ROS and nucleotides are highly susceptible to these free radical injuries. Melanocortin 1 receptor (MC1R) has been known to be implicated in different UV-induced damages such as pigmentation, adaptive tanning, and skin cancer. UV-B induces the formation of pre-vitamin D3 in the epidermal layer of skin. UV-induced tans act as a photoprotection by providing a sun protection factor (SPF) of 3-4 and epidermal hyperplasia. There is a need to prevent the harmful effects and harness the useful effects of UV radiations.

  19. Protective mechanisms and acclimation to solar ultraviolet-B radiation in Oenothera stricta

    Science.gov (United States)

    Robberecht, R.; Caldwell, M. M.

    1981-01-01

    Plant adaptations ameliorating or repairing the damaging effects of ultraviolet-B (UV-B) radiation on plant tissue were investigated. The degree of phenotype plasticity in UV protective mechanisms and acclimation in relation to the natural solar UV-B radiation flux and in an enhanced UV-B irradiance environment was also examined. Mechanisms by which plants avoid radiation, adaptations altering the path of radiation incident on the leaf, and repair processes were considered. Attenuation of UV-B by tissues, UV-B irradiation into the leaf, and the effects of UV-B on photosynthesis were investigated.

  20. Characterization of a smartphone camera's response to ultraviolet A radiation.

    Science.gov (United States)

    Igoe, Damien; Parisi, Alfio; Carter, Brad

    2013-01-01

    As part of a wider study into the use of smartphones as solar ultraviolet radiation monitors, this article characterizes the ultraviolet A (UVA; 320-400 nm) response of a consumer complementary metal oxide semiconductor (CMOS)-based smartphone image sensor in a controlled laboratory environment. The CMOS image sensor in the camera possesses inherent sensitivity to UVA, and despite the attenuation due to the lens and neutral density and wavelength-specific bandpass filters, the measured relative UVA irradiances relative to the incident irradiances range from 0.0065% at 380 nm to 0.0051% at 340 nm. In addition, the sensor demonstrates a predictable response to low-intensity discrete UVA stimuli that can be modelled using the ratio of recorded digital values to the incident UVA irradiance for a given automatic exposure time, and resulting in measurement errors that are typically less than 5%. Our results support the idea that smartphones can be used for scientific monitoring of UVA radiation. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

  1. Ocular exposure to ultraviolet and visible radiation from light sources

    International Nuclear Information System (INIS)

    Hietanen, M.

    1992-01-01

    Exposure of the eyes to UV radiation and blue light of artificial light sources and the sun was evaluated. A spectroradiometer was used to determine the spectral irradiance at 1 nm intervals from 250 to 800 nm. Various groups of workers are at risk of ocular over-exposure to optical radiation, outdoor workers maintenance personnel of bright light source as and wear eye-protectors with effective filtering of UV radiation and blue light. (author)

  2. Ultraviolet radiation and cyanobacteria.

    Science.gov (United States)

    Rastogi, Rajesh Prasad; Sinha, Rajeshwar P; Moh, Sang Hyun; Lee, Taek Kyun; Kottuparambil, Sreejith; Kim, Youn-Jung; Rhee, Jae-Sung; Choi, Eun-Mi; Brown, Murray T; Häder, Donat-Peter; Han, Taejun

    2014-12-01

    Cyanobacteria are the dominant photosynthetic prokaryotes from an ecological, economical, or evolutionary perspective, and depend on solar energy to conduct their normal life processes. However, the marked increase in solar ultraviolet radiation (UVR) caused by the continuous depletion of the stratospheric ozone shield has fueled serious concerns about the ecological consequences for all living organisms, including cyanobacteria. UV-B radiation can damage cellular DNA and several physiological and biochemical processes in cyanobacterial cells, either directly, through its interaction with certain biomolecules that absorb in the UV range, or indirectly, with the oxidative stress exerted by reactive oxygen species. However, cyanobacteria have a long history of survival on Earth, and they predate the existence of the present ozone shield. To withstand the detrimental effects of solar UVR, these prokaryotes have evolved several lines of defense and various tolerance mechanisms, including avoidance, antioxidant production, DNA repair, protein resynthesis, programmed cell death, and the synthesis of UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin. This study critically reviews the current information on the effects of UVR on several physiological and biochemical processes of cyanobacteria and the various tolerance mechanisms they have developed. Genomic insights into the biosynthesis of MAAs and scytonemin and recent advances in our understanding of the roles of exopolysaccharides and heat shock proteins in photoprotection are also discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

    International Nuclear Information System (INIS)

    Perez, C.F.

    1984-08-01

    The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT + colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references

  4. Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Perez, C.F.

    1984-08-01

    The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT/sup +/ colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references.

  5. UV radiation sources for artificial skin tanning and protection

    International Nuclear Information System (INIS)

    Zivkovic, D.; Hrnjak, M.

    1999-01-01

    UV radiation sources for artificial tanning are more utilized at the last time. UV radiation is not harmless, so there are not safety devices for tanning. If people do not want to avoid exposure to their radiation, than it is necessary to take the prevention measure: strictly dose of UV radiation according to skin type, use of appropriate protective eye-wears and respect for inhibit of some medicaments and some cosmetic products use. (author)

  6. Effects of intense ultraviolet radiation on electrostatic energy analyzers

    International Nuclear Information System (INIS)

    Mathew, J.; Jennings, W.C.; Hickok, R.L.; Connor, K.A.; Schoch, P.M.; Hallock, G.A.

    1984-01-01

    Intense ultraviolet radiation from the plasma poses a significant problem for the implementation of heavy ion beam probe diagnostic systems on fusion-oriented confinement devices. The radiation enters the electrostatic energy analyzer used to detect secondary ions, resulting in both a distortion of the electric field inside the analyzer and noise generation in the detector channels. Data acquisition procedures and mechanical design techniques have been developed to significantly reduce these effects. We have also been successful in modelling the electric field distortion and have developed a data correction procedure based on this model. Methods for approaching the problems anticipated in future devices are also suggested

  7. Absolute measurement of undulator radiation in the extreme ultraviolet

    International Nuclear Information System (INIS)

    Maezawa, H.; Kitamura, H.; Sasaki, T.; Mitani, S.; Osaka City Univ.; Suzuki, Y.; Kanamori, H.; Tamamushi, S.; Tokyo Univ.; Mikuni, A.; Tokyo Univ., Tanashi

    1983-01-01

    The spectral brightness of undulator radiation emitted by the model PMU-1 incorporated in the SOR-RING, the dedicated synchrotron radiation source in Tokyo, has been studied in the extreme ultraviolet region from 21.6 to 72.9 eV as a function of the electron energy #betta#, the field parameter K, and the angle of observation THETA in the absolute scale. A series of measurements covering the first and the second harmonic component of undulator radiation was compared with the fundamental formula lambdasub(n)=lambda 0 /2n#betta# 2 (1+K 2 /2+#betta# 2 THETA 2 ), and the effects of finite emittance were studied. The brightness at the first peak was smaller than the theoretical value, while an enhanced second harmonic component was observed. (orig.)

  8. Determinants of personal ultraviolet-radiation exposure doses on a sun holiday

    DEFF Research Database (Denmark)

    Petersen, B; Thieden, E; Philipsen, P A

    2013-01-01

    A great number of journeys to sunny destinations are sold to the Danish population every year. We suspect that this travel considerably increases personal annual ultraviolet-radiation (UVR) exposure doses. This is important because such exposure is the main cause of skin cancer, and studies have...

  9. The octadecanoid signalling pathway in plants mediates a response to ultraviolet radiation

    International Nuclear Information System (INIS)

    Conconi, A.; Smerdon, M.J.; Howe, G.A.; Ryan, C.A.

    1996-01-01

    Many plant genes that respond to environmental and developmental changes are regulated by jasmonic acid, which is derived from linolenic acid via the octadecanoid pathway. Linolenic acid is an important fatty-acid constituent of membranes in most plant species and its intracellular levels increase in response to certain signals. Here we report that irradiation of tomato leaves with ultraviolet light induces the expression of several plant defensive genes that are normally activated through the octadecanoid pathway after wounding. The response to ultraviolet light is blocked by an inhibitor of the octadecanoid pathway and it does not occur in a tomato mutant defective in this pathway. The ultraviolet irradiation maximally induces the defence genes at levels where cyclobutane pyrimidine dimer formation, an indicator of DNA damage, is less than 0.2 dimers per gene. Our evidence indicates that this plant defence response to certain wavelengths of ultraviolet radiation requires the activation of the octadecanoid defence signalling pathway. (author)

  10. Ecological modulation of environmental stress: interactions between ultraviolet radiation, epibiotic snail embryos, plants and herbivores.

    Science.gov (United States)

    Wahl, Martin

    2008-05-01

    1. The distribution of egg masses of the freshwater snails Lymnaea stagnalis and Planorbarius corneus on the undersides of water lily leaves (e.g. Nuphar lutea) is related to the prevalence of the leaf-mining beetle Galerucella nymphaeae. 2. When given the choice, Planorbarius significantly avoids leaves that were infested by the mining beetle. Conversely, Lymnaea did not discriminate against mined leaves. 3. Intact Nuphar leaves block over 95% of incident ultraviolet radiation. Yet, ultraviolet transmission reaches almost 100% under beetle mining scars. These are several times wider than snail embryos. 4. When exposed to natural sunlight, Lymnaea embryos proved to be resistant to ambient ultraviolet, while Planorbarius embryos were rapidly killed. Thus, one selective advantage of Planorbarius discrimination against mined leaves when depositing its eggs could be the avoidance of ultraviolet radiation passing through mining scars. 5. Other mining-related modifications of the leaves, reduced area, decreased longevity, altered aufwuchs (i.e. biofilm and epibionts) are discussed but seem less relevant for the oviposition preference of Planorbarius. 6. The discriminatory behaviour of this snail species was triggered by water-borne cues emitted by the damaged leaf, not by the eggs or larvae of the beetle. 7. This study illustrates how environmental stress on a given species, ultraviolet radiation in this case, can be ecologically buffered (shading by Nuphar) or enhanced (reduction of Nuphar shading through beetle mining) by associated species. It highlights how the impact of a given stress depends on the identity of the target species as well as on the identity and role of other species in the community.

  11. Action spectra in mammalian cells exposed to ultraviolet radiation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    A review is given of the literature published since 1977 on action spectra in mammalian cells exposed to ultraviolet radiation in the wavelength region above 220 nm. Action spectra for lethal events are discussed for cell inactivation in normal cells, growth arrested cells and photosensitive cells. Action spectra for non-lethal events are also discussed in relation to pyrimidine dimer formation, photoreactivation and the use of photosensitisers. It was concluded from these studies that damage to the DNA, and the extent of the repair of this damage, seems to determine a cell's response to such parameters as inactivation, mutation, transformation, latent viral activation, cellular viral capacity and ultraviolet enhanced viral reactivation. In addition to the direct effects of UV on DNA, photosensitization of cellular responses with chemicals such as 8-MOP extend the wavelength range at which damage can be demonstrated. (U.K.)

  12. Estimation of Solar Radiation using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Slamet Suprayogi

    2004-01-01

    Full Text Available The solar radiation is the most important fator affeccting evapotranspiration, the mechanism of transporting the vapor from the water surface has also a great effect. The main objectives of this study were to investigate the potential of using Artificial Neural Network (ANN to predict solar radiation related to temperature. The three-layer backpropagation were developed, trained, and tested to forecast solar radiation for Ciriung sub Cachment. Result revealed that the ANN were able to well learn the events they were trained to recognize. Moreover, they were capable of effecctively generalize their training by predicting solar radiation for sets unseen cases.

  13. Effect of ultraviolet radiation on laboratory cultures of green algae and cyanobacteria

    International Nuclear Information System (INIS)

    Palffy, K.; Ordog, V.; Voros, L.

    2004-01-01

    Since the discovery of the ozone hole, an increasing amount of work has been devoted to measuring the impact of the UV-radiation on living organisms. In this point of view, algae as the primer producers of aquatic ecosystems, get to the central part of the interest. The aim of the study was to study the effect of ultraviolet radiation on laboratory cultures of green algae and cyanobacteria

  14. Ultraviolet-B radiation absorbing capacity of leaf hairs

    International Nuclear Information System (INIS)

    Karabourniotis, G.; Papadopoulos, K.; Papamarkou, M.; Manetas, Y.

    1992-01-01

    Pubescence layers with their native structure and orientation were isolated from the leaves of Olea europaea L. and Olea chrysophylla L. They were almost transparent in the visible, but considerable absorptance was evident in the ultraviolet-B region (UV-B), with maximum at 310 nm. Methanolic extracts of hairs from Olea and a variety of other pubescent species consistently showed the existence of UV-screening pigments. Absorptance of trichomes varied, but a trend towards more effective UV-B radiation attenuation in the sub-alpine Verbascum species may be claimed. In all cases, pigments were located within hair cells and in Olea they were characterized as phenolics with considerable flavonoid contribution. It is suggested that leaf hairs, besides other functions, may constitute a shield against UV-B radiation. (author)

  15. How does solar ultraviolet-B radiation improve drought tolerance of silver birch (Betula pendula Roth.) seedlings?

    Science.gov (United States)

    Robson, T Matthew; Hartikainen, Saara M; Aphalo, Pedro J

    2015-05-01

    We hypothesized that solar ultraviolet (UV) radiation would protect silver birch seedlings from the detrimental effects of water stress through a coordinated suite of trait responses, including morphological acclimation, improved control of water loss through gas exchange and hydraulic sufficiency. To better understand how this synergetic interaction works, plants were grown in an experiment under nine treatment combinations attenuating ultraviolet-A and ultraviolet-B (UVB) from solar radiation together with differential watering to create water-deficit conditions. In seedlings under water deficit, UV attenuation reduced height growth, leaf production and leaf length compared with seedlings receiving the full spectrum of solar radiation, whereas the growth and morphology of well-watered seedlings was largely unaffected by UV attenuation. There was an interactive effect of the treatment combination on water relations, which was more apparent as a change in the water potential at which leaves wilted or plants died than through differences in gas exchange. This suggests that changes occur in the cell wall elastic modulus or accumulation of osmolites in cells under UVB. Overall, the strong negative effects of water deficit are partially ameliorated by solar UV radiation, whereas well-watered silver birch seedlings are slightly disadvantaged by the solar UV radiation they receive. © 2014 John Wiley & Sons Ltd.

  16. Is ultraviolet radiation a synergistic stressor in combined exposures? The case study of Daphnia magna exposure to UV and carbendazim

    International Nuclear Information System (INIS)

    Ribeiro, Fabianne; Ferreira, Nuno C.G.; Ferreira, Abel; Soares, Amadeu M.V.M.; Loureiro, Susana

    2011-01-01

    The toxicological assessment of chemical compounds released to the environment is more accurate when mixtures of chemicals and/or interactions between chemicals and natural stressors are considered. Ultraviolet radiation can be taken as a natural stressor since the levels of UV are increasing due to the decrease of its natural filter, the stratospheric ozone concentration. Therefore, a combination of chemical exposures and increasing UV irradiance in aquatic environments is likely to occur. In the current study, combined effects of carbendazim and ultraviolet radiation were evaluated, using selected life traits as endpoints on Daphnia magna. To design combined exposures, first single chemical and natural stressor bioassays were performed: a reproduction test with carbendazim and a reproduction, feeding inhibition and Energy budget test with ultraviolet radiation. Following single exposures, the combinations of stressors included exposures to UV radiation and carbendazim for a maximum exposure time of 4 h, followed by a post-exposure period in chemically contaminated medium for a maximum of 15 days, depending on the endpoint, where the effects of the combined exposures were investigated. Statistical analyses of the data set were performed using the MixTox tool and were based on the conceptual model of Independent Action (IA) and possible deviations to synergism or antagonism, dose-ratio or dose-level response pattern. Both ultraviolet radiation and carbendazim as single stressors had negative impacts on the measured life traits of daphnids, a decrease on both feeding rates and reproduction was observed. Feeding rates and reproduction of D. magna submitted to combined exposures of ultraviolet radiation and carbendazim showed a dose-ratio deviation from the conceptual model as the best description of the data set, for both endpoints. For feeding inhibition, antagonism was observed when the UV radiation was the dominant item in combination, and for reproduction

  17. Implementation of European Directive on Optical Radiation Safety takes place in May 2010

    NARCIS (Netherlands)

    Wieringa, F.P.

    2009-01-01

    At the latest by May 10th 2010, Directive 2006/25/EC regarding the exposure of workers to risks arising from artificial optical radiation must be implemented by all EU-member states, thus legally adopting ICNIRP limit values for ultraviolet, visible and infrared radiation. For IUVA-members the

  18. Effect of ultraviolet radiation (300-400 nanometers) on polypropylene

    International Nuclear Information System (INIS)

    Lerman, S.

    1983-01-01

    Polypropylene discs and shavings were exposed to simulated ambient ultraviolet (UV) radiation (lambda 300-400 nm) for a period equivalent to at least two years of wear within the eye, assuming the eye to be exposed to ambient UV radiation for four hours per day at 1 mW/cm2. The polypropylene and the incubation media were measured by several forms of optical spectroscopy, and there was no photochemical change in either. Where polypropylene discs were exposed to a very high level of UV radiation (greater than 500 W/cm2), they became brittle and discolored within five to ten days. This level of exposure, however, was equivalent to a total of over 20 million joules/cm2, which is at least one million times levels for expected ambient UV exposure to polypropylene within the eye

  19. Ultraviolet radiation after exposure to a low-fluence IPL home-use device

    DEFF Research Database (Denmark)

    Thaysen-Petersen, Daniel; Erlendsson, Andres M; Nash, J F

    2015-01-01

    The prevailing advice is to avoid sun exposure after intense pulsed light (IPL) hair removal. However, no systematic evaluation of ultraviolet radiation (UVR) after IPL hair removal exits. Therefore, we investigated the occurrence of side effects in subjects receiving solar-simulated UVR after...

  20. Coral skeletons defend against ultraviolet radiation.

    Directory of Open Access Journals (Sweden)

    Ruth Reef

    Full Text Available BACKGROUND: Many coral reef organisms are photosynthetic or have evolved in tight symbiosis with photosynthetic symbionts. As such, the tissues of reef organisms are often exposed to intense solar radiation in clear tropical waters and have adapted to trap and harness photosynthetically active radiation (PAR. High levels of ultraviolet radiation (UVR associated with sunlight, however, represent a potential problem in terms of tissue damage. METHODOLOGY/PRINCIPAL FINDINGS: By measuring UVR and PAR reflectance from intact and ground bare coral skeletons we show that the property of calcium carbonate skeletons to absorb downwelling UVR to a significant extent, while reflecting PAR back to the overlying tissue, has biological advantages. We placed cnidarians on top of bare skeletons and a UVR reflective substrate and showed that under ambient UVR levels, UVR transmitted through the tissues of cnidarians placed on top of bare skeletons were four times lower compared to their counterparts placed on a UVR reflective white substrate. In accordance with the lower levels of UVR measured in cnidarians on top of coral skeletons, a similar drop in UVR damage to their DNA was detected. The skeletons emitted absorbed UVR as yellow fluorescence, which allows for safe dissipation of the otherwise harmful radiation. CONCLUSIONS/SIGNIFICANCE: Our study presents a novel defensive role for coral skeletons and reveals that the strong UVR absorbance by the skeleton can contribute to the ability of corals, and potentially other calcifiers, to thrive under UVR levels that are detrimental to most marine life.

  1. On the influence of ultraviolet radiation on spontaneous tumors in NMRI mice

    International Nuclear Information System (INIS)

    Koenigsmann, G.; Kinkel, H.J.; Bocionek, P.; Wolff, F.

    1981-01-01

    During a period of 12 and 15 months respectively, female NMRI mice were irradiated twelve hours per day with specific parts of the ultraviolet spectrum (three groups, each comprising 100 animals: non-irradiated control group, animals irradiated with B units, animals irradiated with A/B units). No considerable influence of the chronic exposure to ultraviolet radiation could be demonstrated with regard to the development of the body weight and the hematologic condition. Group B had the same rate of spontaneous tumors of the respiratory tract as the control group; this rate was higher in group A/B. As to the development of spontaneous tumors in the lymphatic tissues, there seems to be a dependence on radiation: the animals of group B presented a slightly higher, those of group A/B a higher development than the animals of the nonirradiated control group. It cannot be definitely clarified yet to what extent this increased tumor rate was additionally induced by the higher environmental temperature or other influences involved by experiment. Harding-Passey melanomas were inoculated in NMRI mice and, 48 hours later, they were exposed to defined emission spectra within the natural ultraviolet spectrum. The exposed animals showed a slower growth of the transplanted tumors than the non-exposed animals, and especially the animals exposed to UVB radiation had a longer survival time. This chronic irradiation test was carried out in order to examine the influence of defined emission spectra on autochthonous tumors in NMRI mice and on their spontaneous tumor rate and blood count. (orig.) [de

  2. Ultra-violet radiation for the inactivation of microorganisms in hydroponics

    International Nuclear Information System (INIS)

    Buyanosvsky, G.; Gale, J.; Degani, N.

    1981-01-01

    The growth of microorganisms in the nutrient solution of a circulating hydroponic system was suppressed by ultra-violet radiation. Applied for three hours daily (572 Jm -2 h -1 ) throughout experiments in which tomato and corn were grown, it was effective in reducing the population of microorganisms from between 500-800 x 10 3 to 10-50 x 10 3 cells per ml. (orig.)

  3. Ultra-violet radiation for the inactivation of microorganisms in hydroponics

    Energy Technology Data Exchange (ETDEWEB)

    Buyanosvsky, G; Gale, J [Ben-Gurion Univ. of the Negev, Beersheva (Israel). Jacob Blaustein Inst. for Desert Research; Degani, N [Israel Atomic Energy Commission, Beersheba. Nuclear Research Center-Negev

    1981-01-01

    The growth of microorganisms in the nutrient solution of a circulating hydroponic system was suppressed by ultra-violet radiation. Applied for three hours daily (572 Jm/sup -2/h/sup -1/) throughout experiments in which tomato and corn were grown, it was effective in reducing the population of microorganisms from between 500-800 x 10/sup 3/ to 10-50 x 10/sup 3/ cells per ml.

  4. Prediction of Global Solar Radiation in India Using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Rajiv Gupta

    2016-06-01

    Full Text Available Increasing global warming and decreasing fossil fuel reserves has necessitated the use of renewable energy resources like solar energy in India. To maximize return on a solar farm, it had to be set up at a place with high solar radiation. The solar radiation values are available only for a small number of places and must be interpolated for the rest. This paper utilizes Artificial Neural Network in interpolation, by obtaining a function with input as combinations of 7 geographical and meteorological parameters affecting radiation, and output as global solar radiation. Data considered was of past 9 years for 13 Indian cities. Low error values and high coefficient of determination values thus obtained, verified that the results were accurate in terms of the original solar radiation data known. Thus, artificial neural network can be used to interpolate the solar radiation for the places of interest depending on the availability of the data.

  5. Lanthanum (III) regulates the nitrogen assimilation in soybean seedlings under ultraviolet-B radiation.

    Science.gov (United States)

    Huang, Guangrong; Wang, Lihong; Zhou, Qing

    2013-01-01

    Ultraviolet-B (UV-B, 280-320 nm) radiation has seriously affected the growth of plants. Finding the technology/method to alleviate the damage of UV-B radiation has become a frontal topic in the field of environmental science. The pretreatment with rare earth elements (REEs) is an effective method, but the regulation mechanism of REEs is unknown. Here, the regulation effects of lanthanum (La(III)) on nitrogen assimilation in soybean seedlings (Glycine max L.) under ultraviolet-B radiation were investigated to elucidate the regulation mechanism of REEs on plants under UV-B radiation. UV-B radiation led to the inhibition in the activities of the key enzymes (nitrate reductase, glutamine synthetase, glutamate synthase) in the nitrogen assimilation, the decrease in the contents of nitrate and soluble proteins, as well as the increase in the content of amino acid in soybean seedlings. The change degree of UV-B radiation at the high level (0.45 W m(-2)) was higher than that of UV-B radiation at the low level (0.15 W m(-2)). The pretreatment with 20 mg L(-1) La(III) could alleviate the effects of UV-B radiation on the activities of nitrate reductase, glutamine synthetase, glutamate synthase, and glutamate dehydrogenase, promoting amino acid conversion and protein synthesis in soybean seedlings. The regulation effect of La(III) under UV-B radiation at the low level was better than that of UV-B radiation at the high level. The results indicated that the pretreatment with 20 mg L(-1) La(III) could alleviate the inhibition of UV-B radiation on nitrogen assimilation in soybean seedlings.

  6. A study on resistance to ultraviolet radiation of POSS-TiO2/epoxy nanocomposites

    Science.gov (United States)

    Peng, Dequn; Qin, Wei; Wu, Xiaohong

    2015-06-01

    Ultraviolet (UV) radiation is a severe space environmental factor, which is harmful to the durability of the polymeric materials of the spacecraft. For this reason, a novel POSS-TiO2/EP nanocomposite was synthesized by incorporating the POSS-TiO2 organic-inorganic hybrid into the epoxy (EP) resin. The effects of UV radiation on EP resin and on POSS-TiO2/EP nanocomposites were investigated in a ground-based simulator that simulates space radiation conditions. Compared with EP resin, the value of bend strength for 5.0 wt% POSS-TiO2/EP varied in a small range before and after UV radiation. Meanwhile, a typical tough feature was observed from the SEM photo for POSS-TiO2/EP nanocomposite after UV exposure. This result indicated that the POSS-TiO2/EP exhibited the excellent properties of anti-space ultraviolet radiation. The thermo gravimetric (TG) results showed that the addition of POSS-TiO2 improved the thermal-stability of EP resin matrix. The synthesized nanocomposites in this work could be used in the satellites to enhance their adaptability to the space environment and extend their service life.

  7. Outdoor Exposure to Solar Ultraviolet Radiation and Legislation in Brazil.

    Science.gov (United States)

    Silva, Abel A

    2016-06-01

    The total ozone column of 265 ± 11 Dobson Units in the tropical-equatorial zones and 283 ± 16 Dobson Units in the subtropics of Brazil are among the lowest on Earth, and as a result, the prevalence of skin cancer due to solar ultraviolet radiation is among the highest. Daily erythemal doses in Brazil can be over 7,500 J m. Erythemal dose rates on cloudless days of winter and summer are typically about 0.147 W m and 0.332 W m, respectively. However, radiation enhancement events yielded by clouds have been reported with erythemal dose rates of 0.486 W m. Daily doses of the diffuse component of erythemal radiation have been determined with values of 5,053 J m and diffuse erythemal dose rates of 0.312 W m. Unfortunately, Brazilians still behave in ways that lead to overexposure to the sun. The annual personal ultraviolet radiation ambient dose among Brazilian youths can be about 5.3%. Skin cancer in Brazil is prevalent, with annual rates of 31.6% (non-melanoma) and 1.0% (melanoma). Governmental and non-governmental initiatives have been taken to increase public awareness of photoprotection behaviors. Resolution #56 by the Agência Nacional de Vigilância Sanitária has banned tanning devices in Brazil. In addition, Projects of Law (PL), like PL 3730/2004, propose that the Sistema Único de Saúde should distribute sunscreen to members of the public, while PL 4027/2012 proposes that employers should provide outdoor workers with sunscreen during professional outdoor activities. Similar laws have already been passed in some municipalities. These are presented and discussed in this study.

  8. Photosynthesis, growth, and ultraviolet irradiance absorbance of Cucurbita pepo L. leaves exposed to ultraviolet-B radiation (280 to 315 nm)

    International Nuclear Information System (INIS)

    Sisson, W.B.

    1981-01-01

    Net photosynthesis, growth, and ultraviolet (uv) radiation absorbance were determined for the first leaf of Cucurbita pepo L. exposed to two levels of uv-B irradiation and a uv-B radiation-free control treatment. Absorbance by extracted flavonoid pigments and other uv-B radiation-absorbing compounds from the first leaves increased with time and level of uv-B radiation impinging on leaf surfaces. Although absorbance of uv-B radiation by extracted pigments increased substantially, uv-B radiation attenuation apparently was insufficient to protect completely the photosynthetic apparatus or leaf growth processes. Leaf expansion was repressed by daily exposure to 1365 Joules per meter per day of biologically effective uv-B radiation by not by exposure to 660 Joules per meter per day. Photosynthesis measured through ontogenesis of the first leaf was depressed by both uv-B radiation treatments. Repression of photosynthesis by uv-B radiation was especially evident during the ontogenetic period of maximum photosynthetic activity

  9. Maps of ultraviolet radiation in Costa Rica

    International Nuclear Information System (INIS)

    Wright, Jaime

    2009-01-01

    Ultraviolet radiation (UV) has contributed relatively little energy to the solar spectrum; but is important, because it is biologically active. The software Surfer 8 has created maps designed of the territory of Costa Rica to assess the maximum levels of solar UV radiation on a horizontal plane. The data were used in creating the maps, were predicted at local noon in eighty-three locations scattered across the country, with a spectral atmospheric model which is physically established. The model has used as input data: the date and time, the location identified by latitude, longitude and height of land above sea level, the value of the vertical column ozone, surface albedo and atmospheric turbidity parameters. The estimate differs by 3% of the measurements made in situ, which agrees with the experimental data. The model has used the data estimation of UV radiation, clear sky conditions, which is the condition where you get the maximum energy possible in each locality. This is of fundamental importance when assessing the adverse effects on human health, leads the maximum intensity in this important solar spectrum band. A larger increase of 23% has presented in the UV radiation with altitude obtaining the hills and mountains the highest rates and places located at sea level and the lowest cost, the indices. The annual variation analysis has revealed an increase greater than 27% from the month of lowest UV radiation (December) and the month of greatest UV radiation (April). The issue is of particular interest because of the increasing number of people moving at different times of the year, altitudes over 2000 m altitude, in activities relating to tourism and employment. These individuals are significant increases in levels of UV solar radiation under conditions of clear skies. (author) [es

  10. Ozone and ultraviolet radiation. Observations and research in the Netherlands and Belgium

    International Nuclear Information System (INIS)

    1997-01-01

    An overview of recent scientific research in Belgium and the Netherlands on the title subject is given. After an overall introduction on ozone and ultraviolet radiation in chapter 1 attention is paid to observations and monitoring of ozone and UV-radiation in chapter 2 and recent research projects in the Netherlands and Belgium with respect to those quantities in chapter 3. In chapter 4 the biological effects of UV-radiation are described, while in chapter 5 the international policy to protect the ozone layer is discussed as well as the effects of such policy on the UV burden and public health. 10 refs

  11. Ambient ultraviolet radiation induces protective responses in soybean but does not attenuate indirect defense

    International Nuclear Information System (INIS)

    Winter, Thorsten R.; Rostas, Michael

    2008-01-01

    We investigated the effects of ambient ultraviolet (UV) radiation on (i) the performance and chemistry of soybean plants, (ii) the performance of Spodoptera frugiperda and (iii) the foraging behavior of the herbivore's natural enemy Cotesia marginiventris which exploits herbivore-induced plant volatiles (VOC) for host location. The accumulation of protective phenolics was faster in plants receiving ambient UV than in controls exposed to sun light lacking UV. Accordingly, isorhamnetin- and quercetin-based flavonoids were increased in UV exposed plants. No UV effects were found on the performance and feeding behavior of S. frugiperda. Herbivore-damaged plants emitted the same VOC when grown under ambient or attenuated UV for 5, 10 or 30 days. Consequently, C. marginiventris was attracted but did not discriminate between exposed and unexposed soybeans. In summary, ambient UV radiation affected soybean morphology and physiology but did not destabilize interactions between trophic levels. - Ambient ultraviolet radiation does not alter induced VOC emission in soybean and thus host location of the parasitoid Cotesia marginiventris remains effective

  12. Changes in ground-based solar ultraviolet radiation during fire episodes: a case study

    CSIR Research Space (South Africa)

    Wright, CY

    2013-09-01

    Full Text Available Solar ultraviolet radiation (UVR) levels are affected by airborne aerosols, such as particles and gases released during biomass burning events. Two large-scale fires in South Africa were identified and selected based on their proximity to solar UVR...

  13. Calibration technique for radiation measurements in vacuum ultraviolet - soft x-ray region

    International Nuclear Information System (INIS)

    Mizui, Jun-ichi

    1986-05-01

    This is a collection of the papers presented at the workshop on ''Calibration Technique for Radiation Measurements in Vacuum Ultraviolet - Soft X-ray Region'' held at the Institute of Plasma Physics, Nagoya University, on December 19 - 20, 1985, under the Collaborating Research Program at the Institute. The following topics were discussed at the workshop: the needs for the calibration of plasma diagnostic devices, present status of the calibration technique, use of the Synchrotron Orbit Radiations for radiometry, and others. (author)

  14. Comparison in decoloration efficiency among radiation, ultraviolet ray and Fenton oxidation treatment for aqueous solution of dyes

    International Nuclear Information System (INIS)

    Shimokawa, Toshishige; Sawai, Takeshi

    1984-01-01

    To establish the methods of oxidation and decomposition treatment for dyeing waste water, the processes by radiation, ultraviolet ray and Fenton oxidation were examined comparatively for the decoloration efficiency. The dyes tested were commercially available reactive dyes, RBO-3R, DBR-BB, MBY-6GS and RBB-R. In the radiation process, the dye solution was irradiated with gamma ray of cobalt-60 while blowing air through it. Radiation process and Fenton oxidation were excellent for decoloration. Ultraviolet ray was low in the treatment efficiency, so it is not practical. In the radiation process, the addition of a reagent and the adjustment of pH are not required unlike the case of the Fenton oxidation process. Its continuous operation is also possible, so it is a highly practical means. (Mori, K.)

  15. UNLAMINATED GAFCHROMIC EBT3 FILM FOR ULTRAVIOLET RADIATION MONITORING.

    Science.gov (United States)

    Welch, David; Randers-Pehrson, Gerhard; Spotnitz, Henry M; Brenner, David J

    2017-11-01

    Measurement of ultraviolet (UV) radiation is important for human health, especially with the expanded usage of short wavelength UV for sterilization purposes. This work examines unlaminated Gafchromic EBT3 film for UV radiation monitoring. The authors exposed the film to select wavelengths in the UV spectrum, ranging from 207 to 328 nm, and measured the change in optical density. The response of the film is wavelength dependent, and of the wavelengths tested, the film was most sensitive to 254 nm light, with measurable values as low as 10 µJ/cm2. The film shows a dose-dependent response that extends over more than four orders of magnitude. The response of the film to short wavelength UV is comparable to the daily safe exposure limits for humans, thus making it valuable as a tool for passive UV radiation monitoring. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Control of zebra mussels with ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, D.P.

    1998-07-01

    This paper presents the results of research on the effects of low and medium pressure ultraviolet (UV) radiation on zebra mussel mortality carried out between 1992 and 1995. An initial 1992 study, carried out by Aquatic Sciences (ASI), showed that flow-through UV systems have the ability to kill zebra mussels and prevent them from attaching to downstream surfaces. However, this work did not include expanded testing to determine the limitations of UV radiation at higher flow rates or to further define effective working parameters. The 1994 study was carried out at the Lennox Thermal Generating Station (TGS) of Ontario Hydro in Kingston, Ontario. This study involved the testing of two open channel UV systems (medium and low pressure) in an effort to determine flow rates and volumes for which UV disinfection would be effective and practical for the prevention of zebra mussel infestation. It was recommended that medium pressure (MP) and low pressure (LP) UV systems be tested for their ability to control downstream settlement of zebra mussels, in flow-through trials.

  17. Ultraviolet radiation is feasible alternative for desinfeting of aerobic and anaerobic treatment systems sewage in Brazil

    International Nuclear Information System (INIS)

    Daniel, Luis Antonio; Campos, Jose Roberto

    1993-01-01

    This works shows desinfecting results employing ultraviolet radiation to wastes of sewage treatment station on true scales. Wastes of anaerobic, facultative and maturation pools, septic tank and anaerobic reactor were disinfected. It was found a inactive efficiency to coliforms higher than 99.9%. Safe ultraviolet desinfecting is technically applicable to wastes of sewage treatment station applying aerobic or anaerobic process

  18. Melanoma Surveillance in the US: Melanoma, Ultraviolet Radiation, and Socioeconomic Status

    Centers for Disease Control (CDC) Podcasts

    This podcast accompanies the publication of a series of articles on melanoma surveillance in the United States, available in the November supplement edition of the Journal of the American Academy of Dermatology. Chris Johnson, from the Cancer Data Registry of Idaho, discusses analyses examining the relationship between melanoma and two variables at the county level, ultraviolet radiation and socioeconomic status.

  19. Protective mechanisms and acclimation to solar ultraviolet-b radiation in oenothera stricta. Final report

    International Nuclear Information System (INIS)

    Robberecht, R.; Caldwell, M.M.

    1981-12-01

    Plant adaptations ameliorating or repairing the damaging effects of ultraviolet-B (UV-B) radiation on plant tissue were investigated. The degree of phenotype plasticity in UV protective mechanisms and acclimation in relation to the natural solar UV-B radiation flux and in an enhanced UV-B irradiance environment was also examined. Mechanisms by which plants avoid radiation, adaptations altering the path of radiation incident on the leaf, and repair processes were considered. Attenuation of UV-B by tissues, UV-B irradiation into the leaf, and the effects of UV-B on photosynthesis were investigated

  20. Production of narrowband tunable extreme-ultraviolet radiation by noncollinear resonance-enhanced four-wave mixing

    NARCIS (Netherlands)

    Hannemann, S.; Hollenstein, U.; van Duijn, E.J.; Ubachs, W.M.G.

    2005-01-01

    Fourier-transform-limited extreme-ultraviolet (XUV) radiation (bandwidth ≲300 MHz) tunable around 91 nm is produced by use of two-photon resonance-enhanced four-wave mixing on the Kr resonance at 94 093 cm

  1. Un-laminated Gafchromic EBT3 film for ultraviolet radiation monitoring

    International Nuclear Information System (INIS)

    Welch, David; Randers-Pehrson, Gerhard; Brenner, David J.; Spotnitz, Henry M.

    2017-01-01

    Measurement of ultraviolet (UV) radiation is important for human health, especially with the expanded usage of short wavelength UV for sterilization purposes. This work examines un-laminated Gafchromic EBT3 film for UV radiation monitoring. The authors exposed the film to select wavelengths in the UV spectrum, ranging from 207 to 328 nm, and measured the change in optical density. The response of the film is wavelength dependent, and of the wavelengths tested, the film was most sensitive to 254 nm light, with measurable values as low as 10 μJ/cm 2 . The film shows a dose-dependent response that extends over more than four orders of magnitude. The response of the film to short wavelength UV is comparable to the daily safe exposure limits for humans, thus making it valuable as a tool for passive UV radiation monitoring. (authors)

  2. Low doses of ultraviolet-B or ultraviolet-C radiation affect phytohormones in young pea plants

    International Nuclear Information System (INIS)

    Ivanov, S.; Azmi, A.; Prinsen, E.; Van Onckelen, H.; Alexieva, V.; Katerova, Z.

    2009-01-01

    Pea (cv. Scinado) seedlings were exposed to low doses of ultraviolet-B (UV-B; 4.4 and 13.3 kJ/square m/d) or UV-C (0.1 and 0.3 kJ/square m/d) radiation for 14 d. Aminocyclopropane carboxylic acid (ACC), indoleacetic acid (IAA) and abscisic acid (ABA) concentrations were quantified by gas chromatography coupled to mass spectrometry. The accumulation of ACC upon irradiation was dose-dependent. ABA conc. was reduced and IAA conc. increased upon UV-C treatment, whereas the UV-B doses used did not cause significant changes in ABA and IAA levels

  3. Dermal damage from ultraviolet radiation

    International Nuclear Information System (INIS)

    Kligman, L.H.

    1988-01-01

    Ultraviolet (UV) radiation is increasingly recognized as the cause of a vast number of changes in the skin of humans and animals. These include alterations at the molecular, cellular, tissue and systematic levels. In the recent past, much has been learned about the immediate effects in skin of acute UV exposure (i.e. sunburn) with its epidermal cell death, inflammation and vasolidation. With chronic exposure, many of the clinical and histologic effects can be seen only after decades. Visually, these are hyper- and hypopigmented macules, dry scaly, wrinkled skin with a variety of benign, pre-malignant and malignant neoplasms. All epidermal in origin, they lead, inexorably in humans, to the appearance the authors described as photo-aged. Underlying many of these visible manifestations are drastic changes in the dermis. These relate chiefly to destruction of mature collagen, with a compensatory overproduction of reticulin fibers, hyperplasia of elastic fibers eventuating in elastosis, increased levels of the glycosaminoglycans (GAGs) comprising the ground substance and changes in the microvasculature. First described in actinically damaged humans, systematic investigation required an animal model

  4. Wearable device for monitoring momentary presence of intense x-ray and/or ultra-violet radiations

    International Nuclear Information System (INIS)

    Shriner, W.

    1981-01-01

    A credit-card-size clear-plastic-encased device can be worn or carried by a person to warn him of the momentary presence of dangerous intensities of ultra-violet and/or x-ray radiations. A base lamina (e.g. of cardboard) is coated with a material (e.g. zinc-cadmium sulfide or lead-barium sulfate) which fluoresces under such radiations. Numerals, letters, words or symbols are printed over the fluorescent coat with a material inhibitory to said radiations so that a warning message in dark print will appear on a light background when dangerous intensities of said radiations are present. An x-ray-warning area is covered with an ultra-violet absorbing screen so that said area will glow only under x-rays (Which rays will also activate the remaining ultra-violet-responsive area). The colors of the laminas and the coats are so selected that the messages are not visible when dangerous radiations are not present. If desired, only the message can be printed with fluorescent material so as to glow on a darker background. Optionally, step-layer attenuation devices can be added to indicate degrees of radiation; and reflecting surfaces can underlie the fluorescent coat to increase efficiency and/or sensitively

  5. New advances in protection against solar ultraviolet radiation in textiles for summer clothing.

    Science.gov (United States)

    Aguilera, José; de Gálvez, María Victoria; Sánchez-Roldán, Cristina; Herrera-Ceballos, Enrique

    2014-01-01

    Clothing is considered one of the most important tools for photoprotection against harmful solar ultraviolet radiation (UVR). The standard for sun-protective clothing is based on erythema despite other biological effects of UVR on the skin. We analyzed the potential protection against UVR in fabrics destined for summer clothing based on several action spectra. We examined 50 garments classified by type of fabric composition, structure of the fiber yarn and color. The ultraviolet protection factor was calculated based on fabric ultraviolet transmittance corrected for erythema according to the EU standard E-13758 as well as the UVA transmittance of fabrics. UVR protection was also analyzed in base of different action spectra as for previtamin D3, nonmelanoma skin cancer, photoimmunosuppression and photoaging. Most knitted fabrics used for sports T-shirts offered excellent ratings for ultraviolet protection while normal shirts showed very low ratings, particularly against photoaging. The cover is the most influential variable in fabric photoprotection, having an exponential relationship with the UPF. The relation between cover and UVA protection was linearly negative. Information about ultraviolet protection in textiles used for summer clothing should be included in labeling as some types of fabrics, especially those used for shirts, offer very low UVR protection. © 2014 The American Society of Photobiology.

  6. SEURAT: SPH scheme extended with ultraviolet line radiative transfer

    Science.gov (United States)

    Abe, Makito; Suzuki, Hiroyuki; Hasegawa, Kenji; Semelin, Benoit; Yajima, Hidenobu; Umemura, Masayuki

    2018-05-01

    We present a novel Lyman alpha (Ly α) radiative transfer code, SEURAT (SPH scheme Extended with Ultraviolet line RAdiative Transfer), where line scatterings are solved adaptively with the resolution of the smoothed particle hydrodynamics (SPH). The radiative transfer method implemented in SEURAT is based on a Monte Carlo algorithm in which the scattering and absorption by dust are also incorporated. We perform standard test calculations to verify the validity of the code; (i) emergent spectra from a static uniform sphere, (ii) emergent spectra from an expanding uniform sphere, and (iii) escape fraction from a dusty slab. Thereby, we demonstrate that our code solves the {Ly} α radiative transfer with sufficient accuracy. We emphasize that SEURAT can treat the transfer of {Ly} α photons even in highly complex systems that have significantly inhomogeneous density fields. The high adaptivity of SEURAT is desirable to solve the propagation of {Ly} α photons in the interstellar medium of young star-forming galaxies like {Ly} α emitters (LAEs). Thus, SEURAT provides a powerful tool to model the emergent spectra of {Ly} α emission, which can be compared to the observations of LAEs.

  7. Effects of ultraviolet and electron radiations on graphite-reinforced polysulfone and epoxy resins

    International Nuclear Information System (INIS)

    Giori, C.; Yamauchi, T.

    1984-01-01

    Degradation mechanisms have been investigated for graphite/polysulfone and graphite/epoxy laminates exposed to ultraviolet and high-energy electron radiations in vacuum up to 960 equivalent sun hours and 10 9 rads, respectively. Based on GC and combined GC/MS analysis of volatile by-products evolved during irradiation, several free radical mechanisms of composite degradation have been identified. All the composite materials evaluated have shown high electron radiation stability and relatively low ultraviolet stability as indicated by low G values and high quantum yields for gas formation. Mechanical property measurements of irradiated samples did not reveal significant changes, with the possible exception of UV exposed polysulfone laminates. Hydrogen and methane have been identified as the main byproducts of irradiation, along with unexpectedly high levels of CO and CO 2 . Initial G values for methane relative to hydrogen formation are higher in the presence of isopropylidene linkages, which occur in bisphenol-A resins

  8. Ambient ultraviolet radiation induces protective responses in soybean but does not attenuate indirect defense

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Thorsten R. [Department of Botany II, Julius-von-Sachs Institute for Biosciences, University of Wuerzburg, Julius-von-Sachs-Platz 3, 97082 Wuerzburg (Germany); Rostas, Michael [Department of Botany II, Julius-von-Sachs Institute for Biosciences, University of Wuerzburg, Julius-von-Sachs-Platz 3, 97082 Wuerzburg (Germany)], E-mail: rostas@botanik.uni-wuerzburg.de

    2008-09-15

    We investigated the effects of ambient ultraviolet (UV) radiation on (i) the performance and chemistry of soybean plants, (ii) the performance of Spodoptera frugiperda and (iii) the foraging behavior of the herbivore's natural enemy Cotesia marginiventris which exploits herbivore-induced plant volatiles (VOC) for host location. The accumulation of protective phenolics was faster in plants receiving ambient UV than in controls exposed to sun light lacking UV. Accordingly, isorhamnetin- and quercetin-based flavonoids were increased in UV exposed plants. No UV effects were found on the performance and feeding behavior of S. frugiperda. Herbivore-damaged plants emitted the same VOC when grown under ambient or attenuated UV for 5, 10 or 30 days. Consequently, C. marginiventris was attracted but did not discriminate between exposed and unexposed soybeans. In summary, ambient UV radiation affected soybean morphology and physiology but did not destabilize interactions between trophic levels. - Ambient ultraviolet radiation does not alter induced VOC emission in soybean and thus host location of the parasitoid Cotesia marginiventris remains effective.

  9. Thermoluminescent behavior of diamond thin films exposed to ultraviolet radiation

    International Nuclear Information System (INIS)

    Barboza F, M.; Gastelum, S.; Melendrez, R.; Chernov, V.; Bernal, R.; Cruz V, C.; Brown, F.

    2002-01-01

    In this work the thermoluminescent properties of diamond thin films are discussed which are grown up through the chemical vapor method exposed to ultraviolet radiation of 200-280 nm. The films with thickness 3, 6, 9, 12, 180 and 500 microns were grown up using a precursor gas formed of H 2 -CH 4 -CO excited through microwave energy or hot filament.The structure and morphology of the films were examined through scanning electron microscopy, indicating the formation of different diamond polycrystal structures which depend on the type of heating of the precursor gas used as well as the film dimensions. In general, the brilliance curve depends on the sample and the wavelength of the irradiation ultraviolet light, however it presents clearly thermoluminescence bands in 148, 160, 272, 304, 320 and 324 C degrees. The maximum of the thermoluminescence efficiency is obtained for the case of sample exposure with light of 214 nm. The sample of 500 microns is what exhibits greater thermoluminescent efficiency of those studied samples. The thermoluminescent behavior in function of radiation dose presents regions of linearity and supra linearity for higher and small doses respectively. The disappearance of the thermoluminescent signal depends on the characteristics of the film and it can reach until a 30 % of loss before to reach the stability. (Author)

  10. Prolonged ultraviolet light-induced erythema and the cutaneous carcinoma phenotype

    International Nuclear Information System (INIS)

    Tanenbaum, L.; Parrish, J.A.; Haynes, H.A.; Fitzpatrick, T.B.; Pathak, M.A.

    1976-01-01

    A considerable amount of evidence exists in support of the role of ultraviolet radiation as a major etiologic factor in human skin cancer, both melanoma and carcinoma types. On the basis of epidemiologic studies a phenotype has been described which helps to identify the persons who are more susceptible to skin cancer. In an attempt to further define this population, patients with cutaneous carcinoma and a normal control group were exposed to artificial ultraviolet light (UVL) and the erythema and tanning responses of each group were measured over a 21-day period. UVL-induced erythema was prolonged in a significantly higher percentage of patients with skin cancer than in control patients, lasting two to three weeks after single exposures to 6 and 8 times the patient's minimal erythema dose. The presence of prolonged erythema correlated with this history of previous skin cancer but did not correlate with other established risk factors for cutaneous carcinoma, i.e., fair skin, light hair and light eyes, easy sunburning and poor tanning, and Celtic ancestry. Prolonged erythema following UVL radiation may therefore represent an additional risk factor and help to identify the skin cancer-susceptible population

  11. Ultraviolet radiation for the sterilization of contact lenses

    International Nuclear Information System (INIS)

    Gritz, D.C.; Lee, T.Y.; McDonnell, P.J.; Shih, K.; Baron, N.

    1990-01-01

    Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens material. RGP materials were minimally affected by exposure to 300 hours of UV-B. Ultraviolet light is an effective germicidal agent but is injurious to soft lens polymers; its possible utility in the sterilization of RGP lenses and lens cases deserves further study

  12. Some resistance mechanisms to ultraviolet radiation

    International Nuclear Information System (INIS)

    Alcantara D, D.

    2002-12-01

    The cyclical exposure of bacterial cells to the ultraviolet light (UV) it has as consequence an increment in the resistance to the lethal effects of this type of radiation, increment that happens as a result of a selection process of favorable genetic mutations induced by the same UV light. With object to study the reproducibility of the genetic changes and the associate mechanisms to the resistance to UV in the bacteria Escherichia coli, was irradiated cyclically with UV light five different derived cultures of a single clone, being obtained five stumps with different resistance grades. The genetic mapping Hfr revealed that so much the mutation events like of selection that took place during the adaptation to the UV irradiation, happened of random manner, that is to say, each one of the resistant stumps it is the result of the unspecified selection of mutations arisen at random in different genes related with the repair and duplication of the DNA. (Author)

  13. In vitro transformation of primary cultures of neonatal BALB/c mouse epidermal cells with ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Ananthaswamy, H.N.; Kripke, M.L.

    1981-01-01

    Primary epidermal cultures from neonatal BALB/c mice were used to study the carcinogenic effects of ultraviolet radiation in vitro. These cultures were irradiated once through a Falcon plastic dish cover with an FS40 sunlamp [ultraviolet B, lambda approximately 290 to 400 nm] for various lengths of time and maintained for 8 to 12 weeks without subculturing. During this period, most of the cells in the untreated control showed signs of morphological differentiation and eventually died. The cultures irradiated with ultraviolet B radiation also behaved in the same manner except that, in some dishes, small populations of surviving cells began to proliferate and developed into morphologically distinct foci. Seven long-term cell lines were derived from these ultraviolet-irradiated primary epidermal cell cultures. Six of these cell lines produced tumors when injected s.c. into normal and/or immunosuppressed syngeneic recipients. These tumorigenic cell lines lacked definitive characteristics of differentiated epidermal cells, but the cells possessed intermediate junctions, suggesting that they were of epithelial origin. Some of these in vitro-transformed cell lines appeared to be highly antigenic inasmuch as they grew preferentially in immunosuppressed BALB/c mice as compared to their growth in normal syngeneic recipients

  14. The measurement of ultraviolet radiation and sunburn time over southern Ontario

    Science.gov (United States)

    Evans, W. F. J.

    1994-01-01

    Studies of the depletion of ozone which have been conducted from the TOMS instrument on the NIMBUS 7 satellite indicate that total ozone has declined by 5 percent over the last 12 years at most mid-latitudes in the Northern Hemisphere typical of southern Ontario. The measurement of the actual resultant increases in UVB is now important. A monitoring program of UVB (biologically active solar ultraviolet radiation) has been conducted for the last 24 months at a site near Bolton, Ontario. The sunburn time varies from less than 17 minutes in late July, to over 4 hours in December on clear days. The levels depend on solar insolation and total ozone column. The ultraviolet levels are strongly affected by cloud and sky conditions. The implications of present and future depletion on the sunburn time are discussed.

  15. Influence of supplemental ultraviolet-B radiation on lipid peroxidation of Chinese cabbage

    International Nuclear Information System (INIS)

    Huang Shaobai; Zhang Jingjuan; Liu Xiaozhong

    1998-01-01

    Chinese cabbage cultivar Aijiaohuang was grown in an indoor experiment treated by 0.0,130 (simulating 20% ozone depletion)kJm~(-2)day~(-1) of ultraviolet-B(UV-B) for 4 and 7 days to study the effect of supplemental UV-B radiation on flavoniods and lipid peroxidation in the leaves of Chinese cabbage. Accumulation of UV-ABSORBING flavonoids in the leaves of Chinese cabbage was induced by UV-B radiation. Enhanced UV-B radiation reduced ascorbic acid content in the leaves of Chinese cabbage. It was also found that 13.0kJm~(2)day~(-1) UV-B inhibited catalase and superoxide dismutase activities and increased malondiadehyde content in the leaves of Chinese cabbage. These effects induced by UV-B radiation was enhanced with the time course of treatment. The results above suggested that supplemental UV-B radiation enhanced lipid peroxidation of Chinese cabbage, and the accumulation of UV-absorbing flavonoid could not alleviate the damage of UV-B radiation

  16. Ambient ultraviolet radiation causes mortality in salamander eggs

    International Nuclear Information System (INIS)

    Blaustein, A.R.; Edmond, B.; Kiesecker, J.M.

    1995-01-01

    Previous research has shown that amphibian species have differential sensitivity to ultraviolet-B (UV-B) radiation. In some anuran species, ambient levels of UV-B cause mortality in embryonic stages and hatching success is significantly reduced. Projected increases in UV-B may affect an increasing number of species. The adverse effects of UV-B may eventually be manifested at the population level and may ultimately contribute to population declines. Using field experiments, we investigated the effects of ambient UV-B on salamander (Ambystoma gracile) embryos developing at natural oviposition sites. We show that the hatching success of eggs of A. gracile shielded from UV-B is significantly higher than those not shielded from UV-B. 27 refs., 1 fig

  17. Near-ultraviolet radiation blocks SOS responses to DNA damage in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.A.; Eisenstark, A.

    1984-01-01

    Escherichia coli cells in which the recA promoter is fused to a lac structural gene, (Mu) Mud(Ap,lac)::rec, were irradiated with two far-ultraviolet light wavelengths (254 and 290 nm), selected monochromatic near-ultraviolet (NUV) wavelengths 313 nm, 334 nm, 365 nm, or broad band solar-UV (290-420 nm) from a solar simulator. Irradiation with the two far-ultraviolet wavelengths was followed by high yields of ..beta..-galactosidase, lambda prophage induction, and Weigle reactivation. These end points were not observed after irradiation with the selected NUV wavelengths or the broad spectrum solar-UV. Thus, neither broad spectrum solar-UV nor monochromatic NUV wavelengths resulted in the derepression of the recA promoter. Further, prior exposure of the cells either to the selected monochromatic NUV wavelengths or to solar-UV inhibited a) the induction of ..beta..-galactosidase by subsequent 254-nm radiation, b) subsequent 254-nm induction of lambda prophage, c) Weigle reactivation, and d) mutation frequency. These observations are consistent with the hypothesis that NUV blocks subsequent recA protease action.

  18. Autonomous portable solar ultraviolet spectroradiometer (APSUS) - a new CCD spectrometer system for localized, real-time solar ultraviolet (280-400 nm) radiation measurement.

    Science.gov (United States)

    Hooke, Rebecca; Pearson, Andy; O'Hagan, John

    2014-01-01

    Terrestrial solar ultraviolet (UV) radiation has significant implications for human health and increasing levels are a key concern regarding the impact of climate change. Monitoring solar UV radiation at the earth's surface is therefore of increasing importance. A new prototype portable CCD (charge-coupled device) spectrometer-based system has been developed that monitors UV radiation (280-400 nm) levels at the earth's surface. It has the ability to deliver this information to the public in real time. Since the instrument can operate autonomously, it is called the Autonomous Portable Solar Ultraviolet Spectroradiometer (APSUS). This instrument incorporates an Ocean Optics QE65000 spectrometer which is contained within a robust environmental housing. The APSUS system can gather reliable solar UV spectral data from approximately April to October inclusive (depending on ambient temperature) in the UK. In this study the new APSUS unit and APSUS system are presented. Example solar UV spectra and diurnal UV Index values as measured by the APSUS system in London and Weymouth in the UK in summer 2012 are shown. © 2014 Crown copyright. Photochemistry and Photobiology © 2014 The American Society of Photobiology. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland and Public Health England.

  19. TOMS as a monitor of the ultraviolet radiation environment: applications to photobiology

    International Nuclear Information System (INIS)

    Frederick, J.E.

    1987-01-01

    The flux of biologically relevant ultraviolet radiation that reaches the surface of the Earth varies with the ozone amount, surface reflectivity, and cloudcover. The Total Ozone Mapping Spectrometer (TOMS) provides information relevant to all three items. A recent application of satellite-based ozone measurements has been to develop climatologies of the biologically significant UV-B radiation reaching the Earth's surface. A growing body of research suggests that UV-B radiation tends to suppress the immune system of laboratory mice. At tropical latitudes, it is likely that parasitical diseases develop most readily in people who have experienced immune system suppression from UV-B exposure. The computed distribution of surface radiation combined with information on disease incidence may clarify the role of UV-B as a suppressor of the human immune system. TOMS used in conjunction with radiative transfer calculations can provide information of relevance in photobiology

  20. [Artificial intelligence applied to radiation oncology].

    Science.gov (United States)

    Bibault, J-E; Burgun, A; Giraud, P

    2017-05-01

    Performing randomised comparative clinical trials in radiation oncology remains a challenge when new treatment modalities become available. One of the most recent examples is the lack of phase III trials demonstrating the superiority of intensity-modulated radiation therapy in most of its current indications. A new paradigm is developing that consists in the mining of large databases to answer clinical or translational issues. Beyond national databases (such as SEER or NCDB), that often lack the necessary level of details on the population studied or the treatments performed, electronic health records can be used to create detailed phenotypic profiles of any patients. In parallel, the Record-and-Verify Systems used in radiation oncology precisely document the planned and performed treatments. Artificial Intelligence and machine learning algorithms can be used to incrementally analyse these data in order to generate hypothesis to better personalize treatments. This review discusses how these methods have already been used in previous studies. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  1. Replicated mesocosm study on the role of natural ultraviolet radiation in high CDOM, shallow lakes.

    Science.gov (United States)

    Pérez, A Patricia; Diaz, Mónica M; Ferraro, Marcela A; Cusminsky, Gabriela C; Zagarese, Horacio E

    2003-02-01

    The role of ultraviolet radiation on shallow, high CDOM (colored dissolved organic matter) lakes was investigated during two consecutive summers (1999 and 2000) in replicated mesocosms (rectangular fiberglass tanks). Each tank (volume: 300 L; depth: 40 cm) was covered with a layer (approximately 3 cm) of sediment from lake El Toro (40 degrees 14' S; 70 degrees 22' W) and filled with filtered water. The experimental design consisted of two treatments: full natural radiation (UV-exposed) and natural radiation without ultraviolet radiation (UV-shielded). UV-exposed and UV-shielded treatments differed in most studied variables as revealed by repeated measures ANOVA. UV-exposed tanks displayed lower CDOM levels (dissolved absorbance) of lower average molecular size (absorbance ratio between 250 and 365 nm), higher bacterial biomass, and lower chlorophyll a concentration. The effect on consumers (rotifers and crustaceans) was less noticeable. The results are consistent with UV stimulation of bacteria production mediated by higher rates of CDOM photobleaching, and the photoinhibition of planktonic algae. Thus, a major effect of UVR in shallow, high CDOM ecosystems appears to be the stimulation of heterotrophic pathways and a simultaneous inhibition of photoautotrophs.

  2. Comparison of Five Modeling Approaches to Quantify and Estimate the Effect of Clouds on the Radiation Amplification Factor (RAF) for Solar Ultraviolet Radiation

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ultraviolet Radiation (UV) data collected at 21 US Environmental Protection Agency sites throughout the continental US, Alaska, Hawaii, and the US Virgin Islands...

  3. Flavonoids can protect maize DNA from the induction of ultraviolet radiation damage

    International Nuclear Information System (INIS)

    Stapleton, A.E.; Walbot, V.

    1994-01-01

    Diverse flavonoid compounds are widely distributed in angiosperm families. Flavonoids absorb radiation in the ultraviolet (UV) region of the spectrum, and it has been proposed that these compounds function as UV filters. We demonstrate that the DNA in Zea mays plants that contain flavonoids (primarily anthocyanins) is protected from the induction of damage caused by UV radiation relative to the DNA in plants that are genetically deficient in these compounds. DNA damage was measured with a sensitive and simple assay using individual monoclonal antibodies, one specific for cyclobutane pyrimidine dimer damage and the other specific for pyrimidine(6,4)pyrimidone damage. (author)

  4. Decontamination Efficacy of Ultraviolet Radiation against Biofilms of Common Nosocomial Bacteria.

    Science.gov (United States)

    Tingpej, Pholawat; Tiengtip, Rattana; Kondo, Sumalee

    2015-06-01

    Ultraviolet radiation (UV) is commonly used to destroy microorganisms in the health-care environment. However, the efficacy of UV radiation against bacteria growing within biofilms has never been studied. To measure the sterilization effectiveness of UV radiation against common healthcare associated pathogens growing within biofilms. Staphylococcus aureus, Methicillin-resistant S. aureus (MRSA), Streptococcus epidermidis, Escherichia coli, ESBL-producing E. coli, Pseudomonas aeruginosa and Acinetobacter baumannii were cultivated in the Calgary Biofilm Device. Their biofilms were placed 50 cm from the UV lamp within the Biosafety Cabinet. Viability test, crystal violet assay and a scanning electron microscope were used to evaluate the germicidal efficacy. Within 5 minutes, UV radiation could kill S. aureus, MRSA, S. epidermidis, A. baumannii and ESBL-producing E. coli completely while it required 20 minutes and 30 minutes respectively to kill E. coli and P. aeruginosa. However, the amounts of biomass and the ultrastructure between UV-exposed biofilms and controls were not significantly different. UV radiation is effective in inactivating nosocomial pathogens grown within biofilms, but not removing biofilms and EPS. The biofilm of P. aeruginosa was the most durable.

  5. Increased outdoor recreation, diminished ozone layer pose ultraviolet radiation threat to eye

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-24

    The long-term effects of ultraviolet (UV) light on the eye are of increasing concern as many people live longer and spend more of that time in outdoor recreation and as the diminishing ozone layer filters less UV light. Ultraviolet radiation is strongest at high altitude, low latitude, and open for reflective environments (sand, snow, or water). For people who lack an eye lens (aphakics), UV light is transmitted directly onto the retina. Cumulative exposure to the 300- to 400-nm range of UV light is one factor causing cataracts. Ophthalmologists say cataracts cause visual deficits for more than 3.5 million people in the United States. Cumulative UV exposure may lead to age-related macular degeneration. At a Research to Prevent Blindness conference in Arlington, VA, John S. Werner, PhD, professor of psychology and neurosciences at the University of Colorado, Boulder, described how his group demonstrated the effects of UV light on retinal cones. Different types of intraocular lenses were placed in each eye of eight patients who had undergone bilateral cataract surgery. After five years, retinal cones chronically exposured to UV radiation had less sensitivity for short wavelengths (440 nm) by a factor of 1.7.

  6. Assessment and comparison of methods for solar ultraviolet radiation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Leszczynski, K

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.).

  7. Assessment and comparison of methods for solar ultraviolet radiation measurements

    International Nuclear Information System (INIS)

    Leszczynski, K.

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.)

  8. The effect of melatonin on eye lens of rats exposed to ultraviolet radiation.

    Science.gov (United States)

    Anwar, M M; Moustafa, M A

    2001-05-01

    We investigated the influence of exogenously administered melatonin on adult rats eye lenses exposed to ultraviolet radiation (UV) A and B ranging from 356-254 nm irradiation at 8 microW/cm(2). Rats exposed to this range of UV for 15 min for one week showed a significant (PUV-radiation significantly (PUV irradiation, may be the main cause of lens opacification. Melatonin injection with radiation significantly reduced (Pradiation, SOD and GSH-Px enzyme activities increased significantly (PUV radiation was as effective as melatonin treatment concurrent with UV irradiation. We conclude that melatonin may protect the eye lens from the damaging effects of UV exposure, and its actions protect lens from oxidative stress, elevating Ca(2+) levels, which are considered as an important causes of cataractogenesis.

  9. Current and future impacts of ultraviolet radiation on the terrestrial carbon balance

    Institute of Scientific and Technical Information of China (English)

    W. Kolby SMITH; Wei GAO; Heidi STELTZER

    2009-01-01

    One of the most documented effects of human activity on our environment is the reduction of stratospheric ozone resulting in an increase of biologically harmful ultraviolet (UV) radiation. In a less predictable manner, UV radiation incident at the surface of the earth is expected to be further modified in the future as a result of altered cloud condition, atmospheric aerosol concentration, and snow cover. Although UV radiation comprises only a small fraction of the total solar radiation that is incident at the earth's surface, it has the greatest energy per unit wavelength and, thus, the greatest potential to damage the biosphere. Recent investigations have highlighted numerous ways that UV radiation could potentially affect a variety of ecological processes, including nutrient cycling and the terrestrial carbon cycle. The objectives of the following literature review are to summarize and synthesize the available information relevant to the effects of UV radiation and other climate change factors on the terrestrial carbon balance in an effort to highlight current gaps in knowledge and future research directions for UV radiation research.

  10. The potential sensitivity of tropical plants to increased ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Ziska, L.H.

    1996-01-01

    Little is known concerning the impact of stratospheric ozone depletion and increasing ultraviolet (UV)-B radiation on the phenology and growth of tropical plants. This is because, ostensibly, tropical plants are already exposed to relatively high levels of UV-B radiation (relative to a temperate environment) and should, therefore, possess a greater degree of tolerance to increased UV-B radiation. In this brief review I hope to show that, potentially, direct and indirect effects on photosynthesis, assimilate partitioning, phenology and biomass could occur in both tropical crops (e.g. cassava, rice) and native species (e.g. Cecropia obtusifolia (Bertol. Fl)., Tetramolopium humile (Gray), Nana sandwicensis L.). However, it should be noted that differences in sensitivity to UV-B radiation can be related to experimental conditions, and care should be taken to ensure that the quantity and quality of background solar radiation remains at near ambient conditions. Nevertheless, by integrating current and past studies on the impact of UV-B radiation on tropical species, I hope to be able to demonstrate that photosynthesis, morphology and growth in tropical plants could be directly affected by UV-B radiation and that UV-B radiation may be a factor in species and community dynamics in natural plant populations in the tropics

  11. Sensitivity of Escherichia coli acrA Mutants to Psoralen plus Near-Ultraviolet Radiation

    DEFF Research Database (Denmark)

    Hansen, M. Trier

    1982-01-01

    The sensitivity to psoralen plus near-ultraviolet radiation (PUVA) was compared in a pair of E. coli strains differing at the acrA locus. Survival was determined for both bacteria and phage λ. AcrA mutant cells were 40 times more sensitive than wild type to the lethal effect of PUVA. Free λ phage...

  12. Potentiation of the generation of reactive oxidants by human phagocytes during exposure to benoxaprofen and ultraviolet radiation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.; Eftychis, H.A.

    1986-09-01

    The effects of ultraviolet (UV) radiation on the spontaneous membrane-associated oxidative metabolism of human polymorphonuclear leukocytes (PMNL) and mononuclear leukocytes (MNL), co-incubated in the presence and absence of the non-steroidal, anti-inflammatory drug (NSAID) benoxaprofen at various concentrations, were investigated in vitro. Assays of superoxide generation and luminol-enhanced chemiluminescence (CL) were used to detect the production of reactive oxidants by PMNL and MNL. The pro-oxidative effects of benoxaprofen and UV radiation alone and in combination are dependent on intact phagocyte membrane-associated oxidative metabolism. It is postulated that the pro-oxidative interactions which occur between human phagocytes, benoxaprofen and ultraviolet radiation cause the dermatological side-effects of benoxaprofen.

  13. Ultraviolet radiation and autoimmune disease: insights from epidemiological research

    International Nuclear Information System (INIS)

    Ponsonby, Anne-Louise; McMichael, Anthony; Mei, Ingrid van der

    2002-01-01

    This review examines the epidemiological evidence that suggests ultraviolet radiation (UVR) may play a protective role in three autoimmune diseases: multiple sclerosis, insulin-dependent diabetes mellitus and rheumatoid arthritis. To date, most of the information has accumulated from population studies that have studied the relationship between geography or climate and autoimmune disease prevalence. An interesting gradient of increasing prevalence with increasing latitude has been observed for at least two of the three diseases. This is most evident for multiple sclerosis, but a similar gradient has been shown for insulin-dependent diabetes mellitus in Europe and North America. Seasonal influences on both disease incidence and clinical course and, more recently, analytical studies at the individual level have provided further support for a possible protective role for UVR in some of these diseases but the data are not conclusive. Organ-specific autoimmune diseases involve Th1 cell-mediated immune processes. Recent work in photoimmunology has shown ultraviolet B (UVB) can specifically attenuate these processes through several mechanisms which we discuss. In particular, the possible contribution of an UVR-induced increase in serum vitamin D (1,25(OH) 2 D 3 ) levels in the beneficial immunomodulation of these diseases is discussed

  14. Laser Desorption Postionization Mass Spectrometry of Antibiotic-Treated Bacterial Biofilms using Tunable Vacuum Ultraviolet Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gasper, Gerald L; Takahashi, Lynelle K; Zhou, Jia; Ahmed, Musahid; Moore, Jerry F; Hanley, Luke

    2010-08-04

    Laser desorption postionization mass spectrometry (LDPI-MS) with 8.0 ? 12.5 eV vacuum ultraviolet synchrotron radiation is used to single photon ionize antibiotics andextracellular neutrals that are laser desorbed both neat and from intact bacterial biofilms. Neat antibiotics are optimally detected using 10.5 eV LDPI-MS, but can be ionized using 8.0 eV radiation, in agreement with prior work using 7.87 eV LDPI-MS. Tunable vacuum ultraviolet radiation also postionizes laser desorbed neutrals of antibiotics and extracellular material from within intact bacterial biofilms. Different extracellular material is observed by LDPI-MS in response to rifampicin or trimethoprim antibiotic treatment. Once again, 10.5 eV LDPI-MS displays the optimum trade-off between improved sensitivity and minimum fragmentation. Higher energy photons at 12.5 eV produce significant parent ion signal, but fragment intensity and other low mass ions are also enhanced. No matrix is added to enhance desorption, which is performed at peak power densities insufficient to directly produce ions, thus allowing observation of true VUV postionization mass spectra of antibiotic treated biofilms.

  15. MDS G(N) fast differentiation between natural and artificial gamma radiation with a new class of mobile instruments

    International Nuclear Information System (INIS)

    Katzung, W.; Bottcher, J.

    2009-01-01

    A State-of-the-Art tool used for detecting and tracking artificial gamma radiation out of a helicopter or a vehicle is the MDS G(N) - Mobile Detection System. A highly sensitive scintillation detector detects a significant artificial gamma radiation on the ground even if the helicopter is travelling at high speed. The GPS-aided system visualizes the measured values on a moveable map displayed on the screen of a notebook every second. The colours of the continuously entered points do represent adjustable alarm thresholds. This way, location and intensity of an unknown radioactive source or a radioactive contamination can be determined very quickly. The NBR-technology (Natural Background Rejection) which is used here leads to expressive measurement results differentiating between artificial and natural gamma radiation. Additional He-3 detectors allow simultaneously the detection of neutrons. The NBR principle - developed by Thermo Scientific - stands out for its very short response times. Thus, artificial radiation can be detected reliably within seconds - even when the unit is operated by untrained staff. Unlike traditional analytic measuring techniques, the NBR method is able to detect artificial radiation sources hidden or strongly shielded gamma sources clearly from the natural background radiation. The measuring range from 1 nSv/h to 20 ?Sv/h and is extended to 1 Sv/h with a Geiger Mueller counting tube. The sensitivity amounts to max. 20000 cps (referred to 1 ?Sv/h for Cs-137). The NBR- technique is well-proven and tested for: tracking hidden radiation sources, even such ones with low activity or which are shielded, detection of artificial radiation portions in the range of the natural background, reliably measuring the ambient equivalent dose rate in the range of the natural background, fast detection of artificial radioactivity out of helicopters and vehicles.(author)

  16. Vacuum-ultraviolet circular dichroism of amino acids as revealed by synchrotron radiation spectrophotometer

    International Nuclear Information System (INIS)

    Matsuo, Koichi; Matsushima, Yosuke; Fukuyama, Takayuki; Gekko, Kunihiko; Senba, Shinya

    2002-01-01

    We succeeded in constructing a vacuum-ultraviolet circular dichroism (VUVCD) spectrophotometer with a small-scale synchrotron radiation source (0.7 GeV) at Hiroshima Synchrotron Radiation Center (HiSOR). This VUVCD system revealed for the first time the CD spectra of amino acids in aqueous media in the 310-140 nm region under high vacuum. These data, which cannot be observed by any types of existing CD spectrophotometers, now open a new field in the structural analysis of biomaterials on a basis of the higher energy transition of chromophores. (author)

  17. Mutations induced by ultraviolet radiation affecting virulence in Puccinia striiformis

    International Nuclear Information System (INIS)

    Shang Hongsheng; Jing Jinxue; Li Zhenqi

    1994-01-01

    Uredospores of parent culture, cy 29-1, were treated by ultraviolet radiation and mutations to virulent were tested on resistant wheat cultivars inoculated with treated spores. 7 mutant cultures virulent to the test cultivars were developed with estimated mutation rate 10~6~10~4. The virulence of mutant cultures was different from the all known races of stripe rust. Resistance segregation to mutant cultures was detected in two test cultivars. The results suggested that mutation was important mechanism of virulence variation operative in asexual population of rust fungi

  18. Drinking water disinfection by means of ultraviolet radiation

    International Nuclear Information System (INIS)

    Gelzhaeuser, P.; Bewig, F.; Holm, K.; Kryschi, R.; Reich, G.; Steuer, W.

    1985-01-01

    The book presents all lectures held during a course at Technical Academy Esslingen, on September 10, 1985, on the subject of 'Drinking water disinfection by means of ultraviolet radiation'. The methods hitherto used for disinfection are no longer suitable because of the increasing amounts of organic pollutants found in the untreated water, and because of the necessity to make drinking water disinfection less expensive, non-polluting and thus environmentally compatible. U.V. irradiation is a method allowing technically simple and safe disinfection of the water, and also does not have any effect on the natural taste of the drinking water. The lectures presented discuss all aspects of the method, the equipment, and the performance of irradiation systems in practice. (orig./PW) [de

  19. Biological Sensors for Solar Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    André P. Schuch

    2011-04-01

    Full Text Available Solar ultraviolet (UV radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products.

  20. Photoprotection beyond ultraviolet radiation--effective sun protection has to include protection against infrared A radiation-induced skin damage.

    Science.gov (United States)

    Schroeder, P; Calles, C; Benesova, T; Macaluso, F; Krutmann, J

    2010-01-01

    Solar radiation is well known to damage human skin, for example by causing premature skin ageing (i.e. photoageing). We have recently learned that this damage does not result from ultraviolet (UV) radiation alone, but also from longer wavelengths, in particular near-infrared radiation (IRA radiation, 760-1,440 nm). IRA radiation accounts for more than one third of the solar energy that reaches human skin. While infrared radiation of longer wavelengths (IRB and IRC) does not penetrate deeply into the skin, more than 65% of the shorter wavelength (IRA) reaches the dermis. IRA radiation has been demonstrated to alter the collagen equilibrium of the dermal extracellular matrix in at least two ways: (a) by leading to an increased expression of the collagen-degrading enzyme matrix metalloproteinase 1, and (b) by decreasing the de novo synthesis of the collagen itself. IRA radiation exposure therefore induces similar biological effects to UV radiation, but the underlying mechanisms are substantially different, specifically, the cellular response to IRA irradiation involves the mitochondrial electron transport chain. Effective sun protection requires specific strategies to prevent IRA radiation-induced skin damage. 2010 S. Karger AG, Basel.

  1. Response of tomato to radiation intensity and air temperature under plastic-house ultraviolet protection

    International Nuclear Information System (INIS)

    Syakur, A.

    2002-01-01

    Enhance of ultraviolet radiation intensity on the earth surface affected by ozon depletion on stratospheric layer cause changing on the response of plant to radiation quality. One technique for reducing photo destructive UV radiation is micro climate modification by using mulch and plastic-cover UV protection. So that, growth and yield of plant can be optimalized. This research designed an experiment to find out the effect of two kinds of plastic-cover, UV plastic and conventional plastic, on microclimate condition and tomato performance under plastic-house. The result of this research described that mulch and plastic cover can modify radiation and air temperature under plastics-house, but it can not improve growth and yield of the tomato [in

  2. Photodegradation of two tropical wood species: jatoba (Hymenaea courbaril) and tauari (Couratari oblongifolia) submitted to ultraviolet radiation

    International Nuclear Information System (INIS)

    Costa, J. de A.; Gonçalez, J.C.; Camargos, J.A.A.

    2011-01-01

    The objective of this study was to follow the process of photodegradation of the natural color of wood surface of two tropical species when exposed to ultraviolet radiation. It were used the wood of jatobá (Hymenaea courbaril) with reddish brown coloration, and tauari (Couratari oblongifolia) with yellowish olive coloration. Samples of these woods were subjected to four cycles of ultraviolet radiation (UV) amounting to a total of 168 hours of irradiation and at 350 nm of wave length. Changes of the woods natural color, indicative of the photodegradation process, was monitored by spectrocolorimetry. Both species underwent changes in color caused by photodegradation, since the irradiation caused darkening which was quantified by the intensity of reflected light. Tauari demonstrated greater resistance to UV radiation and jatobá showed greater tendency to redden up. Both species were classified as woods with very appreciable variation in color [pt

  3. Temperature dependence of UV radiation effects in Arctic and temperate isolates of three red macrophytes

    NARCIS (Netherlands)

    van de Poll, W.H.; Eggert, A.; Buma, A.G.J.; Breeman, Arno

    The temperature dependence of UV effects was studied for Arctic and temperate isolates of the red macrophytes Palmaria palmata, Coccotylus truncatus and Phycodrys rubens. The effects of daily repeated artificial ultraviolet B and A radiation (UVBR: 280-320 nm, UVAR: 320-400 nm) treatments were

  4. Environment and health: 3. Ozone depletion and ultraviolet radiation

    International Nuclear Information System (INIS)

    De Gruijl, F.R.; Van der Leun, J.C.

    2000-01-01

    Ultraviolet radiation from the sun is responsible for a variety of familiar photochemical reactions, including photochemical smog, bleaching of paints and decay of plastics. Conjugated bonds in organic molecules such as proteins and DNA absorb the UV radiation, which can damage these molecules. By a fortunate evolutionary event, the oxygen produced by photosynthesis forms a filter in the outer reaches of our atmosphere that absorbs the most energetic and harmful UV radiation, with wavelengths below 240 nm (in the UVC band [wavelength 100-280 nm]). In the process, the oxygen molecules split up and recombine to form ozone (Fig. 1). This ratified ozone layer (spread out between 10 and 50 Ion in the stratosphere but only 3 mm thick were it compressed at ground level) in turn efficiently absorbs UV radiation of higher wavelengths (tip to about 310 nm). A part of the UV radiation in the UVB band (wavelength 280-315 nm) still reaches ground level and is absorbed in sufficient amounts to have deleterious effects on cells. The less energetic radiation in the UVA band (wavelength 315-400 nm, bordering the visible band [wavelength 400-800 nm]) is not absorbed by ozone and reaches ground level without much attenuation through a clear atmosphere (i.e., no clouds, no air pollution). Although not completely innocuous, the UVA radiation in sunlight is much less photochemically active and therefore generally less harmful than UVB radiation. Life on earth has adapted itself to the UV stress, particularly UVB stress, fbr example by forming protective UV-absorbing surface layers, by repairing cell damage or by replacing damaged cells entirely. Human skin shows all of these adaptive features. Our eyes are less well adapted, but dicy, are shielded by the brows and by squinting. (author)

  5. Impact of plasma jet vacuum ultraviolet radiation on reactive oxygen species generation in bio-relevant liquids

    Energy Technology Data Exchange (ETDEWEB)

    Jablonowski, H.; Hammer, M. U.; Reuter, S. [Center for Innovation Competence plasmatis, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Leibniz Institute for Plasma Science and Technology, INP Greifswald e.V. Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Bussiahn, R.; Weltmann, K.-D.; Woedtke, Th. von [Leibniz Institute for Plasma Science and Technology, INP Greifswald e.V. Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

    2015-12-15

    Plasma medicine utilizes the combined interaction of plasma produced reactive components. These are reactive atoms, molecules, ions, metastable species, and radiation. Here, ultraviolet (UV, 100–400 nm) and, in particular, vacuum ultraviolet (VUV, 10–200 nm) radiation generated by an atmospheric pressure argon plasma jet were investigated regarding plasma emission, absorption in a humidified atmosphere and in solutions relevant for plasma medicine. The energy absorption was obtained for simple solutions like distilled water (dH{sub 2}O) or ultrapure water and sodium chloride (NaCl) solution as well as for more complex ones, for example, Rosewell Park Memorial Institute (RPMI 1640) cell culture media. As moderate stable reactive oxygen species, hydrogen peroxide (H{sub 2}O{sub 2}) was studied. Highly reactive oxygen radicals, namely, superoxide anion (O{sub 2}{sup •−}) and hydroxyl radicals ({sup •}OH), were investigated by the use of electron paramagnetic resonance spectroscopy. All species amounts were detected for three different treatment cases: Plasma jet generated VUV and UV radiation, plasma jet generated UV radiation without VUV part, and complete plasma jet including all reactive components additionally to VUV and UV radiation. It was found that a considerable amount of radicals are generated by the plasma generated photoemission. From the experiments, estimation on the low hazard potential of plasma generated VUV radiation is discussed.

  6. [Analysis of the cumulative solar ultraviolet radiation in Mexico].

    Science.gov (United States)

    Castanedo-Cázares, Juan Pablo; Torres-Álvarez, Bertha; Portales-González, Bárbara; Martínez-Rosales, Karla; Hernández-Blanco, Diana

    2016-01-01

    The incidence of skin cancer has increased in Mexico in recent years. Ultraviolet radiation is the main risk factor associated. Due to the need to develop strategies to prevent skin cancer, the aim of the study was to estimate the UV intensity in several representative regions of Mexico, the average annual UV dose of these populations, and the potential benefit of applying sunscreen at different ages. The intensity of UV radiation was quantified by remote and terrestrial radiometry. The dose of UV exposure was measured in minimal erythema doses using validated models for face and arms. The benefit of using a sunscreen was calculated with the use of a sunscreen with SPF 15 from birth to age 70. The UV radiation is lower in December and greater in the period from May to July. The region with a lower annual dose is Tijuana; and the higher annual dose is in the Mexico City area. The annual difference between these regions was 58 %. Through life, a low SPF sunscreen can reduce up to 66 % of the received UV dose. The geographical location is a risk factor for accumulation of UV radiation in Mexico. Since childhood, people receive high amounts of it; however, most of this dose can be reduced using any commercially available sunscreen, if applied strategically.

  7. Protective Effect of Chitin Urocanate Nanofibers against Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    Ikuko Ito

    2015-12-01

    Full Text Available Urocanic acid is a major ultraviolet (UV-absorbing chromophore. Chitins are highly crystalline structures that are found predominantly in crustacean shells. Alpha-chitin consists of microfibers that contain nanofibrils embedded in a protein matrix. Acid hydrolysis is a common method used to prepare chitin nanofibrils (NFs. We typically obtain NFs by hydrolyzing chitin with acetic acid. However, in the present study, we used urocanic acid to prepare urocanic acid chitin NFs (UNFs and examined its protective effect against UVB radiation. Hos: HR-1 mice coated with UNFs were UVB irradiated (302 nm, 150 mJ/cm2, and these mice showed markedly lower UVB radiation-induced cutaneous erythema than the control. Additionally, sunburn cells were rarely detected in the epidermis of UNFs-coated mice after UVB irradiation. Although the difference was not as significant as UNFs, the number of sunburn cells in mice treated with acetic acid chitin nanofibrils (ANFs tended to be lower than in control mice. These results demonstrate that ANFs have a protective effect against UVB and suggest that the anti-inflammatory and antioxidant effects of NFs influence the protective effect of ANFs against UVB radiation. The combination of NFs with other substances that possess UV-protective effects, such as urocanic acid, may provide an enhanced protective effect against UVB radiation.

  8. Response of sugar beet plants to ultraviolet-B (280-320 nm) radiation and Cercospora leaf spot disease

    International Nuclear Information System (INIS)

    Panagopoulos, I.; Bornman, J.F.; Björn, L.O.

    1992-01-01

    Sugar beet (Beta vulgaris L.) plants injected with Cercospora beticola Sacc. as well as non-infected plants were grown under visible light with or without ultraviolet-B (UV-B, 280-320 nm) radiation for 40 days. An interaction between UV-B radiation and Cercospora leaf spot disease was observed, resulting in a large reduction in leaf chlorophyll content, dry weight of leaf laminae, petioles and storage roots. Lipid peroxidation in leaves also increased the most under the combined treatments. This was also true for ultraweak luminescence from both adaxial and abaxial leaf surfaces. However, no correlation between lipid peroxidation and ultraweak luminescence was observed. Ultraviolet-B radiation given alone appeared to have either a stimulating effect, giving an increase in dry weight of laminac and reducing lipid peroxidation, or no effect. This lack of effect was seen in the absence of change in dry weight of storage roots and chlorophyll content relative to controls. The study demonstrated a harmful interaction between UV-B radiation and Cercospora leaf spot disease on sugar beet

  9. Study of the influence of ultraviolet radiation on aggregative properties of blood red cell by light backscattering

    International Nuclear Information System (INIS)

    Azhnaj, L.; Chueltehm, D.

    1988-01-01

    The method based on the fact of measurable intensity of backscattered laser beam resulting from the angular distribution of scattered light is investigated. The method permits study of the mechanisms of aggregation and disaggregation processes by ultraviolet radiation and action of some inductors. The ultraviolet light acting directly on erythrocyte rouleaus of 10 x 100 μ causes the scattering of laser beam of wavelength 632,8 nm. According the above mentioned fact at an agle of approximately 180 0 the light intensity is measured. Stabilized blood sample is exposed to laser beam by means of fiber optics. Backscattering light transmitted through the photomultiplier and direct current supply is recorded. Quantitative concept of erythrocyte aggregation process is calculated from the plot. Blood sample is mixed by magnetic mixer and the measuring temperature is kept constantly at 37 0 C. Accordingly, the present model can adequately reproduce complex blood red cells kinetics. The influence of ultraviolet radiation and different kinds of inductors on erythrocytes' aggregation is experimentally studied depending on time. 2 figs. (B.Sh.)

  10. Pregnancy outcome and ultraviolet radiation; A systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Megaw, Lauren, E-mail: lauren.megaw@ed.ac.uk [School of Women' s and Infants Health, University of Western Australia, 35 Crawley Ave, Crawley, Perth, Western Australia (Australia); Edinburgh Tommy' s Centre for Reproductive Health, Queen' s Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh (United Kingdom); Clemens, Tom, E-mail: Tom.clemens@ed.ac.uk [School of Geosciences, University of Edinburgh, Drummond St, Edinburgh, Midlothian (United Kingdom); Dibben, Chris, E-mail: Chris.dibben@ed.ac.uk [School of Geosciences, University of Edinburgh, Drummond St, Edinburgh, Midlothian (United Kingdom); Weller, Richard, E-mail: Richard.weller@ed.ac.uk [MRC Centre for Inflammation Research, Queen' s Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh (United Kingdom); Stock, Sarah, E-mail: Sarah.stock@ed.ac.uk [School of Women' s and Infants Health, University of Western Australia, 35 Crawley Ave, Crawley, Perth, Western Australia (Australia); Edinburgh Tommy' s Centre for Reproductive Health, Queen' s Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh (United Kingdom)

    2017-05-15

    Background: Season and vitamin D are indirect and direct correlates of ultraviolet (UV) radiation and are associated with pregnancy outcomes. Further to producing vitamin D, UV has positive effects on cardiovascular and immune health that may support a role for UV directly benefitting pregnancy. Objectives: To investigate the effects of UV exposure on pregnancy; specifically fetal growth, preterm birth and hypertensive complications. Methods: We conducted a systematic review of Medline, EMBASE, DoPHER, Global Health, ProQuest Public Health, AustHealth Informit, SCOPUS and Google Scholar to identify 537 citations, 8 of which are included in this review. This review was registered on PROSPERO and a. narrative synthesis is presented following PRISMA guidance. Results: All studies were observational and assessed at high risk of bias. Higher first trimester UV was associated with and improved fetal growth and increased hypertension in pregnancy. Interpretation is limited by study design and quality. Meta-analysis was precluded by the variety of outcomes and methods. Discussion: The low number of studies and risk of bias limit the validity of any conclusions. Environmental health methodological issues are discussed with consideration given to design and analytical improvements to further address this reproductive environmental health question. Conclusions: The evidence for UV having benefits for pregnancy hypertension and fetal growth is limited by the methodological approaches utilized. Future epidemiological efforts should focus on improving the methods of modeling and linking widely available environmental data to reproductive health outcomes. - Highlights: • Biologically plausible pathways support an association between ultraviolet radiation (UV) and pregnancy outcomes. • This study is the first systematic review of prevailing literature on the relationship between UV and singleton pregnancy outcomes. • It focuses on both substantive findings and the

  11. Pregnancy outcome and ultraviolet radiation; A systematic review

    International Nuclear Information System (INIS)

    Megaw, Lauren; Clemens, Tom; Dibben, Chris; Weller, Richard; Stock, Sarah

    2017-01-01

    Background: Season and vitamin D are indirect and direct correlates of ultraviolet (UV) radiation and are associated with pregnancy outcomes. Further to producing vitamin D, UV has positive effects on cardiovascular and immune health that may support a role for UV directly benefitting pregnancy. Objectives: To investigate the effects of UV exposure on pregnancy; specifically fetal growth, preterm birth and hypertensive complications. Methods: We conducted a systematic review of Medline, EMBASE, DoPHER, Global Health, ProQuest Public Health, AustHealth Informit, SCOPUS and Google Scholar to identify 537 citations, 8 of which are included in this review. This review was registered on PROSPERO and a. narrative synthesis is presented following PRISMA guidance. Results: All studies were observational and assessed at high risk of bias. Higher first trimester UV was associated with and improved fetal growth and increased hypertension in pregnancy. Interpretation is limited by study design and quality. Meta-analysis was precluded by the variety of outcomes and methods. Discussion: The low number of studies and risk of bias limit the validity of any conclusions. Environmental health methodological issues are discussed with consideration given to design and analytical improvements to further address this reproductive environmental health question. Conclusions: The evidence for UV having benefits for pregnancy hypertension and fetal growth is limited by the methodological approaches utilized. Future epidemiological efforts should focus on improving the methods of modeling and linking widely available environmental data to reproductive health outcomes. - Highlights: • Biologically plausible pathways support an association between ultraviolet radiation (UV) and pregnancy outcomes. • This study is the first systematic review of prevailing literature on the relationship between UV and singleton pregnancy outcomes. • It focuses on both substantive findings and the

  12. Development of Ultraviolet (UV) Radiation Protective Fabric Using Combined Electrospinning and Electrospraying Technique

    Science.gov (United States)

    Sinha, Mukesh Kumar; Das, B. R.; Kumar, Kamal; Kishore, Brij; Prasad, N. Eswara

    2017-06-01

    The article reports a novel technique for functionization of nanoweb to develop ultraviolet (UV) radiation protective fabric. UV radiation protection effect is produced by combination of electrospinning and electrospraying technique. A nanofibrous web of polyvinylidene difluoride (PVDF) coated on polypropylene nonwoven fabric is produced by latest nanospider technology. Subsequently, web is functionalized by titanium dioxide (TiO2). The developed web is characterized for evaluation of surface morphology and other functional properties; mechanical, chemical, crystalline and thermal. An optimal (judicious) nanofibre spinning condition is achieved and established. The produced web is uniformly coated by defect free functional nanofibres in a continuous form of useable textile structural membrane for ultraviolet (UV) protective clothing. This research initiative succeeds in preparation and optimization of various nanowebs for UV protection. Field Emission Scanning Electron Microscope (FESEM) result reveals that PVDF webs photo-degradative behavior is non-accelerated, as compared to normal polymeric grade fibres. Functionalization with TiO2 has enhanced the photo-stability of webs. The ultraviolet protection factor of functionalized and non-functionalized nanowebs empirically evaluated to be 65 and 24 respectively. The developed coated layer could be exploited for developing various defence, para-military and civilian UV protective light weight clothing (tent, covers and shelter segments, combat suit, snow bound camouflaging nets). This research therefore, is conducted in an attempt to develop a scientific understanding of PVDF fibre coated webs for photo-degradation and applications for defence protective textiles. This technological research in laboratory scale could be translated into bulk productionization.

  13. Specific locus mutagenesis of human mammary epithelial cells by ultraviolet radiation

    International Nuclear Information System (INIS)

    Eldridge, S.R.; Gould, M.N.

    1991-01-01

    Tissue and locus specificity of mutation induction was studied in human mammary epithelial cells (HMEC). Primary HMEC from normal tissue, and immortalized HMEC (184B5) derived from normal HMEC, were cultured under identical conditions and exposed to 10J/m 2 ultraviolet (UV) radiation (254 nm peak wavelength), which produced approximately 50% mean survival in all cell strains and lines tested. UV radiation was found to induce mutations at the Na + -K + ATPase locus as determined by ouabain-resistance in both normal and immortalized HMEC. Mutation frequencies measured in these cells following UV exposure were similar to those reported for human diploid fibroblasts. Mutation induction was investigated at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus in normal and immortalized HMEC. Induced mutations at the HPRT locus as determined by 6-thioguanine resistance in normal primary HMEC were not observed following UV radiation. Mutation induction was observed at this locus UV-exposed immortalized HMEC. (author)

  14. Thermoluminescent of induced calcite by gamma and ultraviolet radiation

    International Nuclear Information System (INIS)

    Lima, J.F. de.

    1987-01-01

    Samples of brazilian calcite, exposed to gamma radiation in laboratory and heated at constant rate of 2.7 0 C/s, showed three glow peaks at 150, 250 and 350 0 C in their thermoluminescent emission curves. The analysis of these peaks, using different models, indicated that they follow a second order kinetics; it has been obtained, for the activation energy, 1.3, 1.5 and 1.7 eV, and, for the pre-exponential factors, 8.1 x 10 14 , 6.8 x10 13 and 2.4 x 10 12 s -1 . Although the total thermoluminescent emission has stayed constant, the relative height of glow peaks has changed with the temperature of annealing in the range of 400 to 700 0 C. Exposed samples were also illuminated with ultraviolet light and the resultant curves showed partial or total bleaching or some glow peaks and the growth of peaks at lower temperatures. Samples of virgin calcite, submited to increasing exposures of gamma rays, showed a corresponding enhancement of the optical absorption bands in the range of 25000 to 47000 cm -1 A subsequent illumination of these samples with ultraviolet light produced a decrease of the optical absorption bands at the same range. (author) [pt

  15. Melanoma Surveillance in the US: Melanoma, Ultraviolet Radiation, and Socioeconomic Status

    Centers for Disease Control (CDC) Podcasts

    2011-10-19

    This podcast accompanies the publication of a series of articles on melanoma surveillance in the United States, available in the November supplement edition of the Journal of the American Academy of Dermatology. Chris Johnson, from the Cancer Data Registry of Idaho, discusses analyses examining the relationship between melanoma and two variables at the county level, ultraviolet radiation and socioeconomic status.  Created: 10/19/2011 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 10/19/2011.

  16. An inexpensive setup for assessing the impact of ambient solar ultraviolet radiation on seedlings

    International Nuclear Information System (INIS)

    Adamse, P.; Reed, H.E.; Krizek, D.T.; Britz, S.J.; Mirecki, R.M.

    1997-01-01

    Because of reductions in stratospheric ozone levels due to chlorofluoromethanes and other trace gases, there has been growing concern about the impact of possible increases in ultraviolet-B (UV-B) radiation. Until recently, most studies have focused on the effects of enhanced UV-B levels, however, these have inherent technical difficulties. Ultraviolet-B exclusion studies afford the investigator a rapid means of assessing the effects of present levels of solar UV-B radiation. Unlike UV-B enhancement, UV-B exclusion studies use the sun as the source of UV-B radiation and selective filters to transmit or absorb this portion of sunlight. This article describes a simple, inexpensive system that was used over a 3-yr period to determine seedling response of cucumber (Cucumis sativus L.), soybean (Glycine max (L.) Merr.), and New Zealand spinach ((Tetragonia tetragonoides (Pallas) Kuntze) to UV-B exclusion. Plants of all three species grown outdoors under UV-B absorbing polyester showed an increase in leaf enlargement and biomass accumulation in comparison to those grown under UV-B transmitting cellulose acetate filters. The bask materials used consist of plastic window boxes, plastic filters that transmit or absorb in the UV-B region, wire supports, and binder clips. This setup can be used to demonstrate bask principles of photobiology and stress physiology. It is ideal for students interested in conducting short-term science projects on the effects of solar UV radiation

  17. Ultraviolet radiation monitoring in makkah city, Saudi Arabia, using thermoluminescence material CaF2:Tm

    International Nuclear Information System (INIS)

    Al-Ghorabie, F.H.; Natto, S.S.; AL-Lehyani, S.A.

    2005-01-01

    The aim of the present study is to explore the possibility of using Ca F2:Tm thermoluminescence material for measuring and monitoring of solar UV R in Makkah City, Saudi Arabia. Several laboratory experiments, prior to the field measurements, were performed included study of the effects of ultraviolet wavelengths on the response of the phosphor, study of the effect of increasing ultraviolet radiation dose on the intensity of thermoluminescence and study the effect of time factor on the thermoluminescence fading of Ca F 2 :Tm. The phosphor was then exposed directly for one hour to sunlight radiation on a daily basis for 90 days in an open field inside Umm Al-Qura university campus. The field measurements were performed during the months of June, July and August 2003 at 1:00 p.m. The laboratory and field results of this study showed that Ca F 2 :Tm can be used as a suitable dosimeter for solar UV R

  18. The protective effect of DNA on the rat cell membrane damage induced by ultraviolet radiation

    International Nuclear Information System (INIS)

    Ma Shouxiang; Zhong Jinyan

    1988-01-01

    The protective effect of DNA on the cell membrane damage induced by ultra-violet radiation was studied. Rat erythrocytes were used as experimental materials. Blood samples were taken from the rat, and centrifuged to separate the plasma. The cells were washed twice with isotonic saline, resuspended in normal saline solution and then irradiated by ultra-violet radiation. The DNA was added before or after irradiation. THe cell suspensions were kept at 5 deg C for 20 hours after irradiation, and then centrifuged. The supernatants were used for hemoglobin determination. The main results obtained may summarized as follows: the cell suspension of erythrocytes were irradiated for 5, 10 and 20 min. The amount of hemolysis induced by irradiation dosage revealed a direct proportional relationship. If DNA (20-40μg/ml) was applied before irradiation, the amount of hemolysis induced apparently decreased. The differences between the control and DNA treated were statistically significant, P<0.01, but insignificant for DNA added after irradiation

  19. Effects of solar ultraviolet radiation on tropical algal communities

    International Nuclear Information System (INIS)

    Santas, R.

    1989-01-01

    This study assessed some of the effects of solar ultraviolet (UV) radiation ion coral reef algal assemblages. The first part of the investigation was carried out under controlled laboratory conditions in the coral reef microcosm at the National Museum of Natural History in Washington, D.C., while a field counterpart was completed at the Smithsonian Institution's marine station on Grand Turk, Turks and Caicos Islands, in the eastern Caribbean. The study attempted to separate the effects of UV-A from those of UV-B. In the laboratory, algal turf assemblages exposed to simulated solar UV radiation produced 55.1% less biomass than assemblages that were not exposed to UV. Assemblages not exposed to UV were dominated by Ectocarpus rhodochondroides, whereas in the assemblage developing under high UV radiation, Enteromorpha prolifera and eventually Schizothrix calcicola dominated. Lower UV-B irradiances caused a proportional reduction in biomass production and had less pronounced effects on species composition. UV-A did not have any significant effects on either algal turf productivity or community structure. In the field, assemblages exposed to naturally occurring solar UV supported a biomass 40% lower than that of assemblages protected from UV-B exposure. Once again, UV-A did not inhibit algal turf productivity

  20. Ultraviolet radiation and the snow alga Chlamydomonas nivalis (Bauer) Wille.

    Science.gov (United States)

    Gorton, Holly L; Vogelmann, Thomas C

    2003-06-01

    Aplanospores of Chlamydomonas nivalis are frequently found in high-altitude, persistent snowfields where they are photosynthetically active despite cold temperatures and high levels of visible and ultraviolet (UV) radiation. The goals of this work were to characterize the UV environment of the cells in the snow and to investigate the existence and localization of screening compounds that might prevent UV damage. UV irradiance decreased precipitously in snow, with UV radiation of wavelengths 280-315 nm and UV radiation of wavelengths 315-400 nm dropping to 50% of incident levels in the top 1 and 2 cm, respectively. Isolated cell walls exhibited UV absorbance, possibly by sporopollenin, but this absorbance was weak in images of broken or plasmolyzed cells observed through a UV microscope. The cells also contained UV-absorbing cytoplasmic compounds, with the extrachloroplastic carotenoid astaxanthin providing most of the screening. Additional screening compound(s) soluble in aqueous methanol with an absorption maximum at 335 nm played a minor role. Thus, cells are protected against potentially high levels of UV radiation by the snow itself when they live several centimeters beneath the surface, and they rely on cellular screening compounds, chiefly astaxanthin, when located near the surface where UV fluxes are high.

  1. Monitoring of the atmospheric ozone layer and natural ultraviolet radiation: Annual report 2011

    Energy Technology Data Exchange (ETDEWEB)

    Svendby, T.M.; Myhre, C.L.; Stebel, K.; Edvardsen, K; Orsolini, Y.; Dahlback, A.

    2012-07-01

    This is an annual report describing the activities and main results of the monitoring programme: Monitoring of the atmospheric ozone layer and natural ultraviolet radiation for 2011. 2011 was a year with generally low ozone values above Norway. A clear decrease in the ozone layer above Norway during the period 1979-1997 stopped after 1998 and the ozone layer above Norway seems now to have stabilized.(Author)

  2. Anisotropy of ultraviolet radiation of high current discharge in a plasma of exploding wire

    International Nuclear Information System (INIS)

    Bogolyubskij, S.L.

    1987-01-01

    The experiments on exploding thin wires in a diode of a high current generator of relativistic electron beams ''Triton'' have demonstrated that the presence of a hot plasma corona and a colder and denser core is typical for appearing radiation coolled Z-pinch. It is found that for 5-10 ns ultraviolet radiation emmitted by plasma channel has a pronounced axial directivity conditioned by quanta with the energy in the 60-120 eV range. Control experiments have shown that this effect is not connected with various near-electrode phenomena

  3. The sun burns: New advice of the Dutch National Health Council on ultraviolet radiation

    International Nuclear Information System (INIS)

    Passchier, W.F.

    1994-01-01

    The aim of the advice of the Dutch National Health Council is to outline the consequences of the depleted ozone layer, and as a result the increased ultraviolet (UV) radiation, on the public health and the environment. In particular, attention is paid to the effect of UV radiation on the immune system, the increased occurrence of carcinomas, melanomas and other forms of skin cancer, the impact on the development of eye defects, and the impact on different levels of ecosystems. A brief overview is given of preventive measures. 5 figs., 1 ref

  4. Impact of ultraviolet radiation treatments on the physicochemical properties, antioxidants, enzyme activity and microbial load in freshly prepared hand pressed strawberry juice.

    Science.gov (United States)

    Bhat, Rajeev; Stamminger, Rainer

    2015-07-01

    Freshly prepared, hand-pressed strawberry fruit juice was exposed to ultraviolet radiation (254 nm) at room temperature (25 ℃ ± 1 ℃) for 15, 30 and 60 min with 0 min serving as control. Results revealed decrease in pH, total soluble solids and titratable acidity, while colour parameters (L*, a* and b* values) and clarity of juice (% transmittance) increased significantly. All the results corresponded to exposure time to ultraviolet radiation. Bioactive compounds (total phenolics, ascorbic acid and anthocyanins) decreased along with a recorded reduction in polyphenol oxidase enzyme and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activities, which were again dependent on exposure time. Results on the microbial studies showed significant reduction by 2-log cycles in aerobic plate count as well as in total yeast and mould counts. Though negative results were observed for certain parameters, this is the first time it was endeavoured to demonstrate the impact of ultraviolet radiation radiation on freshly prepared, hand-pressed strawberries juice. © The Author(s) 2014.

  5. Flavonols Protect Against UV Radiation-Induced Thymine Dimer Formation in an Artificial Skin Mimic.

    Science.gov (United States)

    Maini, Sabia; Fahlman, Brian M; Krol, Ed S

    2015-01-01

    Exposure of skin to ultraviolet light has been shown to have a number of deleterious effects including photoaging, photoimmunosuppression and photoinduced DNA damage which can lead to the development of skin cancer. In this paper we present a study on the ability of three flavonols to protect EpiDerm™, an artificial skin mimic, against UV-induced damage. EpiDerm™ samples were treated with flavonol in acetone and exposed to UVA (100 kJ/m(2) at 365 nm) and UVB (9000 J/m(2) at 310 nm) radiation. Secretion of matrix metalloproteinase-1 (MMP-1) and tumor necrosis factor-α (TNF-a) were determined by ELISA, cyclobutane pyrimidine dimers were quantified using LC-APCI-MS. EpiDerm™ treated topically with quercetin significantly decreased MMP-1 secretion induced by UVA (100 µM) or UVB (200 µM) and TNF-a secretion was significantly reduced at 100 µM quercetin for both UVA and UVB radiation. In addition, topically applied quercetin was found to be photostable over the duration of the experiment. EpiDerm™ samples were treated topically with quercetin, kaempferol or galangin (52 µM) immediately prior to UVA or UVB exposure, and the cyclobutane thymine dimers (T-T (CPD)) were quantified using an HPLC-APCI MS/MS method. All three flavonols significantly decreased T-T (CPD) formation in UVB irradiated EpiDerm™, however no effect could be observed for the UVA irradiation experiments as thymine dimer formation was below the limit of quantitation. Our results suggest that flavonols can provide protection against UV radiation-induced skin damage through both antioxidant activity and direct photo-absorption. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

  6. Evaluation of an enclosed ultraviolet-C radiation device for decontamination of mobile handheld devices.

    Science.gov (United States)

    Mathew, J Itty; Cadnum, Jennifer L; Sankar, Thriveen; Jencson, Annette L; Kundrapu, Sirisha; Donskey, Curtis J

    2016-06-01

    Mobile handheld devices used in health care settings may become contaminated with health care-associated pathogens. We demonstrated that an enclosed ultraviolet-C radiation device was effective in rapidly reducing methicillin-resistant Staphylococcus aureus, and with longer exposure times, Clostridium difficile spores, on glass slides and reducing contamination on in-use mobile handheld devices. Published by Elsevier Inc.

  7. Solar ultraviolet radiation in Australia. Results from network measurements and their use in public education

    International Nuclear Information System (INIS)

    Roy, C.R.; Gies, H.P.; Lokan, K.H.

    1993-01-01

    Growing evidence of global depletion of stratospheric ozone has given additional support to the ultraviolet radiation (UVR) network established by ARL in Australia and Antarctica. The data produced is necessary to increase our knowledge of atmospheric change, human health studies and for public education. (4 figs., 1 tab.)

  8. Role of solar ultraviolet radiation in 'natural' water purification

    Energy Technology Data Exchange (ETDEWEB)

    Calkins, J; Buckles, J D; Moeller, J R [Kentucky Univ., Lexington (USA)

    1976-07-01

    The concentration of Eschericia coli in the input and output of a tertiary wastewater system (4 lagoons) has been monitored over an 11 month period. The integrated flux of biologically active solar ultraviolet (UV) radiation was measured during this period. By also determining (1) the effective temperature in the system, (2) the growth rate of E.coli at the effective temperature, (3) the penetration of the solar UV into the lagoons, (4) the dose-response relation for killing of E.coli by UV and (5) the retention time of water in the system, it is possible to compare the 'die off' expected from solar UV exposure to the actual 'die off' observed for different batches of water. The observed killing of E.coli was quite close to the values calculated, considering the numerous factors involved. Solar UV light would thus seem to be a very important factor in the natural purification of water. Because each successful species must possess characteristics (physiological or behavioral) which provide adequate resistance to solar UV, the ecological role of solar UV radiation has not been widely appreciated.

  9. Growth, bioconversion of isoflavones and probiotic properties of parent and subsequent passages of Lactobacillus upon ultraviolet radiation.

    Science.gov (United States)

    Yeo, Siok-Koon; Liong, Min-Tze

    2012-11-01

    The objective of this study was to evaluate the effects of ultraviolet (UV) radiation (UVB; 90 J/m²) on growth, bioconversion of isoflavones and probiotic properties of parent and subsequent passages of L. casei FTDC 2113. UV radiation significantly enhanced (P radiation also promoted (P radiation were only prevalent in the parent cells without inheritance by first, second and third passage of cells. Although temporary, our results suggested that UV radiation could enhance the bioactive and probiotic potentials of L. casei FTDC 2113, and thus could be applied for the production of probiotic products with enhanced bioactivity.

  10. Univariate and multivariate forecasting of hourly solar radiation with artificial intelligence techniques

    Energy Technology Data Exchange (ETDEWEB)

    Sfetsos, A. [7 Pirsou Str., Athens (Greece); Coonick, A.H. [Imperial Coll. of Science Technology and Medicine, Dept. of Electrical and Electronic Engineering, London (United Kingdom)

    2000-07-01

    This paper introduces a new approach for the forecasting of mean hourly global solar radiation received by a horizontal surface. In addition to the traditional linear methods, several artificial-intelligence-based techniques are studied. These include linear, feed-forward, recurrent Elman and Radial Basis neural networks alongside the adaptive neuro-fuzzy inference scheme. The problem is examined initially for the univariate case, and is extended to include additional meteorological parameters in the process of estimating the optimum model. The results indicate that the developed artificial intelligence models predict the solar radiation time series more effectively compared to the conventional procedures based on the clearness index. The forecasting ability of some models can be further enhanced with the use of additional meteorological parameters. (Author)

  11. Assessment of the human health impact of changes in ultraviolet radiation

    International Nuclear Information System (INIS)

    Elwood, J.M.

    1993-01-01

    Although several major health effects of ultraviolet radiation (UVR) are established, precise quantification of this effect is difficult. New Zealand has the most southerly located major human population in the world, and has a particular contribution to make to worldwide progress. However, current information on the frequency of the relevant health problems is unsatisfactory. Major developments in research in New Zealand are needed. UVR is an established causal factor for malignant melanoma, other types of skin cancer, cataracts and some other eye problems and has been implicated in some immunological effects. (author). 5 refs

  12. Ultraviolet radiation-induced lipid peroxidation in liposomal membrane: modification by capsaicin

    International Nuclear Information System (INIS)

    De, A.K.; Ghosh, J.J.; Mandal, T.K.

    1993-01-01

    Ultraviolet-radiation has been reported to cause lipid peroxidation in the liposomal membrane. In the present study, treatment with capsaicin, (8-methyl-n-vanillyl-6-nonenamide), the pungent principle of red hot pepper, was shown to modify UV-induced lipid peroxidation in the liposomal membrane. Treatment with low doses of capsaicin (less than 0.1 μg/mL of phosphatidyl choline liposome) produced a significant increase in UV-induced lipid peroxidation, while high doses (0.1-0.5 μg/mL of PC liposome) caused a significant decrease of UV-induced peroxidation

  13. Ultraviolet radiation-induced lipid peroxidation in liposomal membrane: modification by capsaicin

    Energy Technology Data Exchange (ETDEWEB)

    De, A. K.; Ghosh, J. J.; Mandal, T. K. [University College of Science, Department of Biochemistry, 35 Ballygunge Circular Road, Calcutta 700-019 (India)

    1993-07-01

    Ultraviolet-radiation has been reported to cause lipid peroxidation in the liposomal membrane. In the present study, treatment with capsaicin, (8-methyl-n-vanillyl-6-nonenamide), the pungent principle of red hot pepper, was shown to modify UV-induced lipid peroxidation in the liposomal membrane. Treatment with low doses of capsaicin (less than 0.1 μg/mL of phosphatidyl choline liposome) produced a significant increase in UV-induced lipid peroxidation, while high doses (0.1-0.5 μg/mL of PC liposome) caused a significant decrease of UV-induced peroxidation.

  14. Resveratrol anti-ultraviolet-induced guinea pig skin injury

    International Nuclear Information System (INIS)

    Li Wenxing; Zhao Ying

    2014-01-01

    Objective: To Estimate on the protection effect of Stilbene on skin damage induced by ultraviolet radiation. Methods: After the normal skin in guinea pig under the intervene of Resveratrol was irradiated with over- dose of ultraviolet rays (UVB and UVA), the samples in every group were matched and compared. Results: The skin tissue in the Resveratrol intervene group irradiated by ultraviolet rays didn't change obviously as compared with that in the self-control group. But, the damage skin tissue in the control group irradiated by ultraviolet did change significantly as compared with that in the Stilbene intervene group. Conclusion: Resveratrol is a good material to protect the skin from damage effect by ultraviolet radiation. (authors)

  15. Competitive interaction in plant populations exposed to supplementary ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Fox, F.M.; Caldwell, M.M.; Utah State Univ., Logan

    1978-01-01

    Changes in plant growth and competitive balance between pairs of competing species were documented as a result of supplementary ultraviolet-B radiation (principally in the 290-315 nm waveband) under field conditions. This component of the terrestrial solar spectrum would be intensified if the atmospheric ozone layer were reduced. A method for calculating and statistically analyzing relative crowding coefficients was developed and used to evaluate the competitive status of the species pairs sown in a modified replacement series. The effect of the supplementary UV-B irradiance was generally detrimental to plant growth, and was reflected in decreased leaf area, biomass, height and density as well as changes competitive balance for various species. For some species, interspecific competition apparently accentuated the effect of the UV-B radiation, while more intense intraspecific competition may have had the same effect for other species. A few species when grown in a situation of more severe mutual interspecific competition exhibited enhanced growth under the UV-B radiation treatment. This, however, was usually associated with a detrimental effect of the radiation, on its competitor and thus was likely the result of its improved competitive circumstance rather than a benefical physiological effect of the radiation. (orig.) [de

  16. Conidioma production of the white root rot fungus [Rosellinia] in axenic culture under near-ultraviolet light radiation

    International Nuclear Information System (INIS)

    Nakamura, H.; Ikeda, K.; Arakawa, M.; Matsumoto, N.

    2002-01-01

    Conidiomata of the white root rot fungus were produced in axenic culture under near-ultraviolet light radiation. Pieces of sterilized Japanese pear twigs were placed on 7-day-old oatmeal agar culture in plates. The plates were further incubated for 5 days and then illuminated by near-ultraviolet light. Synnemata developed on the twigs within 5 weeks in 19 of 20 isolates tested, and conidia were observed in 12 of the 19 isolates. The synnemata and conidia produced were morphologically identical to those of Dematophora necatrix

  17. A Model for Hourly Solar Radiation Data Generation from Daily Solar Radiation Data Using a Generalized Regression Artificial Neural Network

    OpenAIRE

    Khatib, Tamer; Elmenreich, Wilfried

    2015-01-01

    This paper presents a model for predicting hourly solar radiation data using daily solar radiation averages. The proposed model is a generalized regression artificial neural network. This model has three inputs, namely, mean daily solar radiation, hour angle, and sunset hour angle. The output layer has one node which is mean hourly solar radiation. The training and development of the proposed model are done using MATLAB and 43800 records of hourly global solar radiation. The results show that...

  18. INDUCTION OF ARTIFICIAL MEIOTIC GY~OGENESIS WITH ...

    African Journals Online (AJOL)

    BSN

    INDUCTION OF ARTIFICIAL MEIOTIC GY~OGENESIS WITH. ULTRAVIOLET RAYS IN THE AFRICA:" CATFISH, CI.ARIAS. ANGUILLARIS. ABSTRACT. P.O. ALUKO. National Institute for Freshwater Fisheries. Research, P.M.B. 6006, New Bussa. Artificial gynogenesis was induced in Clarias a11gw aris ) fenilizing the eggs ...

  19. Estimation of ultraviolet radiation dose using CaF2:Tb phosphor

    International Nuclear Information System (INIS)

    Fukuda, Y.; Ohtaki, H.; Owaki, S.

    1996-01-01

    To observe and estimate the dose of ultraviolet (UV) radiation in sunlight, the available thermoluminescence (TL) materials were studied. Several kinds of lanthanide elements were doped in pure CaF 2 powdered crystal and the properties of the Tl for UV were observed. The TL intensity from CaF 2 :Tb was the highest among the samples doped with various lanthanide elements, and form the TL emission spectra (380-540 nm) the TL is estimated to be due to inner transition of Tb 3+ . The peak wavelength of the TL excitation light was located approximately at 235 nm and light of a longer wavelength than 320 nm was unable to excite the TL. The ultraviolet response of CaF 2 :Tb depended on its sintering temperature. Even without γ ray pre-irradiation the CaF 2 :Tb sample with 1 h exposure to sunlight has enough sensitivity to estimate the change of UV. Seasonal change of UV intensity in sunlight was measured with this TLD during four months in 1993. The results agreed with that of other institutes in Japan. (author)

  20. Differential sensitivity of coral larvae to natural levels of ultraviolet radiation during the onset of larval competence.

    KAUST Repository

    Aranda, Manuel; Banaszak, Anastazia T; Bayer, Till; Luyten, James; Medina, Mó nica; Voolstra, Christian R.

    2011-01-01

    Scleractinian corals are the major builders of the complex structural framework of coral reefs. They live in tropical waters around the globe where they are frequently exposed to potentially harmful ultraviolet radiation (UVR). The eggs and early

  1. The influence of meteorological factors on solar ultraviolet radiation over Pretoria, South Africa for the year 2012

    CSIR Research Space (South Africa)

    Makgabutlane, M

    2013-09-01

    Full Text Available Pretoria receives a fair amount of solar ultraviolet radiation (UVR). Certain meteorological factors affect the amount of solar UVR that reaches the ground. The most dominant influencing meteorological factors are stratospheric ozone, cloud cover...

  2. Solar ultraviolet radiation effects on biological systems

    International Nuclear Information System (INIS)

    Diffey, B.L.

    1991-01-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK)

  3. Solar ultraviolet radiation effects on biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Diffey, B.L. (Dryburn Hospital, Durham (UK). Regional Medical Physics Dept.)

    1991-03-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK).

  4. Ultraviolet radiation and air contamination during total hip replacement

    International Nuclear Information System (INIS)

    Carlsson, A.S.; Nilsson, B.; Walder, M.H.; Osterberg, K.

    1986-01-01

    Ultraviolet (uv) radiation of the operating room was assessed bacteriologically in an open randomized study of 30 total hip procedures. Volumetric air-sampling demonstrated that the number of colony forming units (cfu m-3) were significantly reduced (P less than 0.001) by uv light, both close to the wound and in the periphery of the operating room. No adverse effects of the uv-irradiation were observed either in the patients or the staff. In operating rooms fitted with a zonal ventilation system and with an air change rate of about 70 h-1, the addition of uv irradiation during surgery may achieve ultra clean air. However, in conventionally ventilated operating rooms uv-irradiation alone is probably not sufficient to do so

  5. The creation of radiation dominated plasmas using laboratory extreme ultra-violet lasers

    Science.gov (United States)

    Tallents, G. J.; Wilson, S.; West, A.; Aslanyan, V.; Lolley, J.; Rossall, A. K.

    2017-06-01

    Ionization in experiments where solid targets are irradiated by high irradiance extreme ultra-violet (EUV) lasers is examined. Free electron degeneracy effects on ionization in the presence of a high EUV flux of radiation is shown to be important. Overlap of the physics of such plasmas with plasma material under compression in indirect inertial fusion is explored. The design of the focusing optics needed to achieve high irradiance (up to 1014 Wcm-2) using an EUV capillary laser is presented.

  6. Minimum exposure limits and measured relationships between the vitamin D, erythema and international commission on non-ionizing radiation protection solar ultraviolet.

    Science.gov (United States)

    Downs, Nathan; Parisi, Alfio; Butler, Harry; Turner, Joanna; Wainwright, Lisa

    2015-01-01

    The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has established guidelines for exposure to ultraviolet radiation in outdoor occupational settings. Spectrally weighted ICNIRP ultraviolet exposures received by the skin or eye in an 8 h period are limited to 30 J m(-2). In this study, the time required to reach the ICNIRP exposure limit was measured daily in 10 min intervals upon a horizontal plane at a subtropical Australian latitude over a full year and compared with the effective Vitamin D dose received to one-quarter of the available skin surface area for all six Fitzpatrick skin types. The comparison of measured solar ultraviolet exposures for the full range of sky conditions in the 2009 measurement period, including a major September continental dust event, show a clear relationship between the weighted ICNIRP and the effective vitamin D dose. Our results show that the horizontal plane ICNIRP ultraviolet exposure may be used under these conditions to provide minimum guidelines for the healthy moderation of vitamin D, scalable to each of the six Fitzpatrick skin types. © 2014 The American Society of Photobiology.

  7. Protection from solar ultraviolet radiation by clothing

    Energy Technology Data Exchange (ETDEWEB)

    Pailthorpe, M. [New South Wales Univ., Kensington, NSW (Australia)

    1996-12-31

    The recently published Australia/New Zealand Standard AS/NZS 4399: l996 `Sun Protective Clothing - Evaluation and Classification` specifies an in vitro spectrophotometric method for the measurement of the ultraviolet (WR) transmission of textiles. Ultraviolet Protection Factors (UPF) are then calculated by convolving the UVR transmission data with standard CIE erythemal response data and ARL solar irradiance data. At the present time the scope of the standard is limited to loose fitting dry clothing. Virtually every textile parameter has an influence on the UPF of the finished garment and hence on the protection afforded to skin from the harmful effects of solar UVR radiation. Textile parameters such as fibre type, the method of spinning the yarn, fabric structure, cover factor, colorant, UVR absorbers and finishing methods determine the UPF of the fabric and hence must be controlled from batch to batch. Since garments generally shrink when washed, multiple wearing and washing cycles usually cause an increase in fabric UPF. Adventitious soiling of fabrics and the absorption of certain components of domestic laundry formulations, e g fluorescent whitening agents, increase fabric UPF ratings. Garments with a high degree of elasticity, e g nylon/lycra sportswear, that are stretched on to fit, will obviously have lower UPFs when stretched than when relaxed. In general fabrics worn in a wet state provide lower protection than when worn dry. On Australia`s most extreme summer day it has been estimated that there are 30 MEDs (minimal erythemal doses) in a dawn to dusk exposure. Thus outdoor workers should be provided with UPF 30 clothing, or better. Results from recent experiments using SK-II hairless mice dressed in UPF 50 `sunsuits` have shown that the mice developed no sun induced skin cancers on the skin areas protected by the UPF 50 fabric whereas multiple tumours developed on the unprotected skin.

  8. Protection from solar ultraviolet radiation by clothing

    International Nuclear Information System (INIS)

    Pailthorpe, M.

    1996-01-01

    The recently published Australia/New Zealand Standard AS/NZS 4399: l996 'Sun Protective Clothing - Evaluation and Classification' specifies an in vitro spectrophotometric method for the measurement of the ultraviolet (WR) transmission of textiles. Ultraviolet Protection Factors (UPF) are then calculated by convolving the UVR transmission data with standard CIE erythemal response data and ARL solar irradiance data. At the present time the scope of the standard is limited to loose fitting dry clothing. Virtually every textile parameter has an influence on the UPF of the finished garment and hence on the protection afforded to skin from the harmful effects of solar UVR radiation. Textile parameters such as fibre type, the method of spinning the yarn, fabric structure, cover factor, colorant, UVR absorbers and finishing methods determine the UPF of the fabric and hence must be controlled from batch to batch. Since garments generally shrink when washed, multiple wearing and washing cycles usually cause an increase in fabric UPF. Adventitious soiling of fabrics and the absorption of certain components of domestic laundry formulations, e g fluorescent whitening agents, increase fabric UPF ratings. Garments with a high degree of elasticity, e g nylon/lycra sportswear, that are stretched on to fit, will obviously have lower UPFs when stretched than when relaxed. In general fabrics worn in a wet state provide lower protection than when worn dry. On Australia's most extreme summer day it has been estimated that there are 30 MEDs (minimal erythemal doses) in a dawn to dusk exposure. Thus outdoor workers should be provided with UPF 30 clothing, or better. Results from recent experiments using SK-II hairless mice dressed in UPF 50 'sunsuits' have shown that the mice developed no sun induced skin cancers on the skin areas protected by the UPF 50 fabric whereas multiple tumours developed on the unprotected skin

  9. Increase in serum 25-hydroxyvitamin-D(3) in humans after solar exposure under natural conditions compared to artificial UVB exposure of hands and face

    DEFF Research Database (Denmark)

    Datta, Pameli; Bogh, Morten Karsten Bentzen; Olsen, Peter

    2012-01-01

    to increase 25(OH)D by 1 nmol l(-1). The artificial dose of 6 SEDs of only hands and face significantly increased 25(OH)D and resulted in a dose of 0.52 SEDs required to increase 25(OH)D significantly by 1 nmol l(-1). Artificial UVB was thus at least 8 times more efficient in increasing 25(OH)D than solar UVR......Vitamin D studies are often performed under controlled laboratory conditions and the findings may be difficult to translate to natural conditions. We aimed to determine and compare the doses of natural solar ultraviolet radiation (UVR) with doses of artificial UVB radiation of hands and face needed...... UVR doses in standard erythema doses (SEDs) were determined with personal wristwatch UV-dosimeters. 29 volunteers (Group 2) received artificial UVB doses of 6 SEDs (N = 14) and 3 SEDs (N = 15) on hands and face during late-winter/early-spring when outdoor UVB is negligible. 25(OH)D-levels were...

  10. Ultraviolet action spectra for aerobic and anaerobic inactivation of Escherichia coli strains specifically sensitive and resistant to near ultraviolet radiations

    International Nuclear Information System (INIS)

    Peak, J.G.; Peak, M.J.; Tuveson, R.W.

    1983-01-01

    Action spectra for the lethal effects of ultraviolet light (254-434 nm) irradiation delivered under aerobic or anaerobic conditions to Escherichia coli RT2 (specifically sensitive to near-UV radiation; > 320 nm) and E. coli RT4 (near-UV resistant) were prepared. Negligible oxygen dependence was observed for both strains below about 315 nm. The oxygen enhancement ratio (OER) for RT4 increased above this wavelength to the longest wavelength used, whereas for RT2 there was a greater increase in the OER to a large peak at 365 nm, then a progressive decrease at longer wavelengths. The results are consistent with the possibility that the sensitivity of strain RT2 to near-UV radiation may be due to hyperproduction of photosensitizer, operating via photodynamic type reactions involving excited species of oxygen. (author)

  11. Measuring and prediction of global solar ultraviolet radiation (0295-0385 μ m) under clear and cloudless skies

    International Nuclear Information System (INIS)

    Wright, Jaime

    2008-01-01

    Values of global solar ultraviolet radiation were measured with an ultraviolet radiometer and also predicted with a atmospheric spectral model. The values obtained with the atmospheric spectral model, based physically, were analyzed and compared with experimental values measured in situ. Measurements were performed for different zenith angles in conditions of clear skies in Heredia, Costa Rica. The necessary input data include latitude, altitude, surface albedo, Earth-Sun distance, as well as atmospheric characteristics: atmospheric turbidity, precipitable water and atmospheric ozone. The comparison between measured and predicted values have been successful. (author) [es

  12. The response of normal and ataxia-telangiectasia human fibroblasts to the lethal effects of far, mid and near ultraviolet radiations

    International Nuclear Information System (INIS)

    Keyse, S.M.; McAleer, M.A.; Davies, D.J.G.; Moss, S.H.

    1985-01-01

    The responses of two ataxia-telangiectasia (A-T) cell strains to the lethal effects of monochromatic far, mid and near ultraviolet radiations have been determined and compared with the responses of three normal human cell strains. The authors results confirm a previous observation that the A-T cell strain AT4BI is abnormally sensitive to the lethal effects of mid u.v. (313 nm) radiation. After far u.v. (254 nm) radiation the strain AT4BI exhibits a small but statistically significant increase in sensitivity compared to the normal strains. Of most interest, in terms of a mechanistic interpretation of the sensitivity of A-T strains, the survival responses of neither A-T strain tested to near u.v. (365 nm) radiation differed significantly from the mean response of the normal strains, although it is of interest that one normal strain (48BR) was found to be significantly more resistant to near u.v. radiation than any of the other strains tested. The results are discussed in terms of the possible induction of radiogenic lesions in DNA by ultraviolet radiations and the possible mechanisms of radiation sensitivity in ataxia-telangiectasia. (author)

  13. Modeling TiO2 nanoparticle phototoxicity: The importance of chemical concentration, ultraviolet radiation intensity, and time

    Science.gov (United States)

    Toxicity of TiO2 nanoparticles (nano-TiO2) to aquatic organisms can be greatly increased upon the exposure to ultraviolet radiation (UV). This phenomenon has received some attention for pelagic species, however, investigations of nano-TiO2 phototoxicity in benthic organisms are s...

  14. DISTRIBUTION PATTERNS OF LENTIC-BREEDING AMPHIBIANS IN RELATION OF ULTRAVIOLET RADIATION EXPOSURE IN WESTERN NORTH AMERICA

    Science.gov (United States)

    An increase in ultraviolet (UV-B) radiation has been posited to be a potential factor in the decline of some amphibian population...Much more work is still needed to determine whether UV-B, either alone or in concert with other factors, is causing widespread population losses in ...

  15. Lack of correlation between the location of choroidal melanoma and ultraviolet radiation dose distribution

    International Nuclear Information System (INIS)

    Schwartz, L.; Ferrand, R.; Boelle, P.Y.; Maylin, C.; D'Hermies, F.; Virmont, J.

    1998-01-01

    Full text of publication follows: ocular melanomas arise from the choroid. The result of our study of a total of 92 ocular melanomas would indicate that there is no preferential location for tumors on the eye. We estimate the ultraviolet (UV) radiation dose distribution using data available in the literature. We then compared tumor location and UV radiation. UVC and UVB do not reach the choroid and UVA is filtered by the cornea and the lens. Only, a small percentage of the incoming rays reach the posterior and inferior part of retina, but none reach the superior and anterior part of the eye. We concluded that it is therefore very unlikely that UV radiation exposure is responsible for choroidal melanoma. (authors)

  16. A novel facility for ageing materials with narrow-band ultraviolet radiation exposure

    International Nuclear Information System (INIS)

    Kaerhae, Petri; Ruokolainen, Kimmo; Heikkilae, Anu; Kaunismaa, Merja

    2011-01-01

    A facility for exploring wavelength dependencies in ultraviolet (UV) radiation induced degradation in materials has been designed and constructed. The device is essentially a spectrograph separating light from a lamp to spectrally resolved UV radiation. It is based on a 1 kW xenon lamp and a flat-field concave holographic grating 10 cm in diameter. Radiation at the wavelength range 250-500 nm is dispersed onto the sample plane of 1.5 cm in height and 21 cm in width. The optical performance of the device has been characterized by radiometric measurements. Using the facility, test samples prepared of regular newspaper have been irradiated from 1 to 8 h. Color changes on the different locations of the aged samples have been quantified by color measurements. Yellowness indices computed from the color measurements demonstrate the capability of the facility in revealing wavelength dependencies of the material property changes in reasonable time frames.

  17. Assessing children's ultraviolet radiation exposure: the potential usefulness of a colorimeter.

    Science.gov (United States)

    Eckhardt, L; Mayer, J A; Creech, L; Johnston, M R; Lui, K J; Sallis, J F; Elder, J P

    1996-12-01

    This study evaluated the colorimeter as an objective measure of children's ultraviolet (UV) radiation exposure. Fifty-eight children, ages 6 to 9 years, attended two summer measurement sessions, with 46 attending a subsequent winter session. Comparisons between summer sessions for the L* scale showed that only the upper arm significantly changed in the tanner direction, while b* scale values indicated significant tanning for all body sites. All exposed body sites changed significantly in the less tan direction between summer and winter measurements. Using colorimeters to objectively measure children's UV exposure has potential applications for skin cancer prevention programs.

  18. DNA damage and photosynthetic inhibition induced by solar ultraviolet radiation in tropical phytoplankton (Lake Titicaca, Bolivia)

    NARCIS (Netherlands)

    Helbling, EW; Villafane, VE; Buma, AGJ; Andrade, M; Zaratti, F

    Experiments were conducted during October 1998 in Lake Titicaca, Bolivia (16 degrees S, 68 degrees W, 3810 m a.s.l), to determine the effects of solar ultraviolet radiation (UVR) on phytoplankton photosynthetic rates and DNA damage. Water samples were taken daily and incubated ir? situ or in

  19. Ultraviolet-B-effects on plants: Spectra of harmful effects, primary damage and UV protective mechanisms

    International Nuclear Information System (INIS)

    Wellmann, E.; Beggs, C.; Moehle, B.; Schneider-Ziebert, U.; Steinmetz, V.; Koch, U.

    1986-01-01

    In two model systems of higher plants, damage caused by ultraviolet-B-radiation was analysed as to its mechanism of action and the spectral quantum efficiency. These investigations were to provide information on the relevance of such UV effects in cases of increased ultraviolet-B-irradiation owing to the destruction of ozone. The results indicate the very high tolerance of the plants to ultraviolet-B-radiation which obviously is the result of very effective protective mechanisms, and show at the same time that potential damage must already be reckoned with, given the current share of ultraviolet-B-radiation in solar radiation. Should ultraviolet-B-radiation be increased, then indirect damage to the plant from the destruction of ultraviolet protective mechanisms through UV-B-radiation will probably constitute a particular risk. (orig./MG) [de

  20. Effects of ultraviolet-B radiation on plants during mild water stress, 4: The insensitivity of soybean internal water relations to ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Teramura, A.H.; Forseth, I.N.; Lydon, J.

    1984-01-01

    The combined effects of ultraviolet-B (UV-B, 280–320 nm) radiation and water stress were investigated on the water relations of greenhouse grown soybean [Glycine max (L.) Merr. cv. Essex]. On a weighted (Caldwell 1971), total daily dose basis, plants received either 0 or 3 000 effective J m 2 UV-B BE supplied by filtered FS-40 sunlamps. The latter dose simulated the solar UV-B radiation anticipated at College Park, Maryland, U.S.A. (39°N latitude) in the event that the global stratospheric ozone column is reduced by 25%. Plants were either well-watered or preconditioned by drought stress cycles. Diurnal measurements of water potential and stomatal conductance were made on the youngest fully expanded leaf. Various internal water relations parameters were determined for detached leaves. Plants were monitored before, during and after water stress. There were no significant differences in leaf water potential or stomatal conductance between treatments before plants were preconditioned to water stress. However, drought stress resulted in significantly lower midday and afternoon leaf water potentials and lower leaf conductances as compared to well-watered plants. UV-B radiation had no additional effect on leaf water potential; however, UV did result in lower leaf conductances in plants preconditioned to water stress. Turgid weight:dry weight ratio, elastic modulus, bound water and relative water content were unaffected by UV-B radiation. Osmotic potentials at full and zero turgor were significantly lower in the drought stressed treatments as compared to well-watered plants. (author)

  1. Ultraviolet radiation as disinfection for fish surgical tools

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Ricardo W.; Markillie, Lye Meng; Colotelo, Alison HA; Geist, David R.; Gay, Marybeth E.; Woodley, Christa M.; Eppard, M. B.; Brown, Richard S.

    2013-04-04

    Telemetry is frequently used to examine the behavior of fish, and the transmitters used are normally surgically implanted into the coelomic cavity of fish. Implantation requires the use of surgical tools such as scalpels, forceps, needle holders, and sutures. When fish are implanted consecutively, as in large telemetry studies, it is common for surgical tools to be sterilized or, at minimum, disinfected between each use so that pathogens that may be present are not spread among fish. To determine the efficacy for this application, ultraviolet (UV) radiation was used to disinfect surgical tools exposed to one of four aquatic organisms that typically lead to negative health issues for salmonids. These organisms included Aeromonas salmonicida, Flavobacterium psychrophilum, Renibacterium salmoninarum, and Saprolegnia parasitica, causative agents of furunculosis, coldwater disease, bacterial kidney disease, and saprolegniasis (water mold), respectively. Four experiments were conducted to address the question of UV efficacy. In the first experiment, forceps were exposed to the three bacteria at three varying concentrations. After exposure to the bacterial culture, tools were placed into a mobile Millipore UV sterilization apparatus. The tools were then exposed for three different time periods – 2, 5, or 15 min. UV radiation exposures at all durations were effective at killing all three bacteria on forceps at the highest bacteria concentrations. In the second experiment, stab scalpels, sutures, and needle holders were exposed to A. salmonicida using the same methodology as used in Experiment 1. UV radiation exposure at 5 and 15 min was effective at killing A. salmonicida on stab scalpels and sutures but not needle holders. In the third experiment, S. parasitica, a water mold, was tested using an agar plate method and forceps-pinch method. UV radiation was effective at killing the water mold at all three exposure durations. Collectively, this study shows that UV

  2. Protective effect of topically applied polypeptide from Chlamys farreri against ultraviolet radiation-induced chronic skin damage in guinea pig

    Science.gov (United States)

    Chi, Mingliang; Cao, Pengli; Yu, Guoying; Zhu, Li; Wang, Yuejun; Wang, Chunbo

    2003-12-01

    Polypeptide from Chlamys farreri (PCF), a topical polypeptide isolated from Chlamys farreri, was used in this experiment aimed to investigate the photoprotective effect of PCF against chronic skin damage induced by ultraviolet A (UVA) and ultraviolet B (UVB) radiation. The chronic ultraviolet-irradiated guinea pig model was established, and visible changes in the skin including wrinkling, sagging and erythema were observed. Malondialdehyde (MDA) and antioxidant enzymes including superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) in the dorsal skin were determined using biochemical methods. The results showed: (1) PCF (5 % and 20%) could greatly protect the dorsal skin of guinea pig against wrinkling, sagging and erythema induced by UV radiation in a concentration-dependent manner. (2) PCF could reduce MDA formation in the dorsal skin caused by UV irradiation, while increasing the activities of SOD and GSH-px. (3) The differences among the PCF groups and UV model group were significant ( Psolar UV spectrum photoprotection; and that the antioxidant property of PCF might play a role in photoprotection.

  3. Physical factors in cataractogenesis: ambient ultraviolet radiation and temperature

    International Nuclear Information System (INIS)

    Sliney, D.H.

    1986-01-01

    A number of environmental cofactors have been implicated in cataracto-genesis. Two have received the greatest attention: ultraviolet radiation (UVR) and ambient temperature. Unfortunately, both temperature and UVR levels vary similarly with geographical latitude. Careful attention to several more refined physical variables and the geometry of exposure may permit investigators to separate the contributory effects of these two physical agents. This paper briefly reviews the available data, estimates the variation of lenticular temperature with ambient temperature, and provides measurements of short-wavelength (UV-B) UVR exposure to the human eye with different meterological conditions. The study attempts to provide epidemiological investigators with more detailed information necessary to perform more accurate studies of cataract and other ocular pathologies that appear to be related to environmental factors. Ocular UV-B radiation exposure levels were measured at nine locations in the USA near 40 degrees latitude at elevations from sea level to 8000 ft. Terrain reflectance is shown to be much more important than terrain elevation; cloud cover and haze may actually increase ocular exposure; and the value of wearing brimmed hats and spectacles varies with the environment. Several avenues for future research are suggested

  4. Two mire species respond differently to enhanced ultraviolet-B radiation: effects on biomass allocation and root exudation

    DEFF Research Database (Denmark)

    Rinnan, Riikka Tiivi Mariisa; Gehrke, Carola; Michelsen, Anders

    2006-01-01

    •  Increased ultraviolet-B (UV-B) radiation arising from stratospheric ozone depletion may influence soil microbial communities via effects on plant carbon allocation and root exudation. •  Eriophorum angustifolium and Narthecium ossifragum plants, grown in peatland mesocosms consisting of Sphagnum...

  5. Effects of solar radiation pressure torque on the rotational motion of an artificial satellite

    Science.gov (United States)

    Zanardi, Maria Cecilia F. P. S.; Vilhenademoraes, Rodolpho

    1992-01-01

    The motion of an artificial satellite about its center of mass is studied considering torques due to the gravity gradient and direct solar radiation pressure. A model for direct solar radiation torque is derived for a circular cylindrical satellite. An analytical solution is obtained by the method of variation of the parameters. This solution shows that the angular variables have secular variation but that the modulus of the rotational angular momentum, the projection of rotational angular momentum on the z axis of the moment of inertia and inertial axis z, suffer only periodic variations. Considering a hypothetical artificial satellite, a numerical application is demonstrated.

  6. Long-term visual health risks from solar ultraviolet radiation

    International Nuclear Information System (INIS)

    Waxler, M.

    1987-01-01

    Ocular exposure to the ultraviolet radiation (UV) contained in sunlight may result in long-term visual health problems. UV plays a role in the etiology of cataracts and possibly in the etiology of visual impairments associated with solar retinopathy, retinopathy of prematurity, ocular aging, cystoid macular edema, retinitis pigmentosa, and senile macular degeneration. The exact does relationships between known UV bioeffects and these ocular problems is, however, uncertain. Thus, there are questions about the extent to which protective measures should be taken to reduce UV exposure of the eye. This paper identifies the long-term visual health problems potentially associated with ocular exposure to solar UV; proposes worst-case assumptions for the role of solar UV in these visual problems; and recommends protective measures based on damage thresholds and worst-case assumptions

  7. Determination of the dosimetric properties of ZrO2: Cu and it use in the ultraviolet radiation dosimetry

    International Nuclear Information System (INIS)

    Molina P, D.; Olvera T, L.; Azorin N, J.; Barrera S, M.; Soto E, A.M.; Rivera M, T.

    2006-01-01

    In this work the experimental results of studying the thermoluminescent characteristics (TL) of the zirconium oxide doped with copper (ZrO 2 : Cu) exposed to ultraviolet light of wavelength in the interval of 200-400 nm are presented. The material in powder form was prepared using the sol-gel method. The dosimetric characteristics studied includes the emission curve TL (curved TL), the thermoluminescent response in function of the wavelength, the minimum dose detectable and the lineality of the response. The TL response of the ZrO 2 : Cu in function of the wavelength presents two maxima, in 260 and 290 nm, respectively. The TL curve of the ZrO 2 : Cu showed two peaks, in 120 and 170 C, respectively, being its similar form for all the studied wavelengths. The response in function of the spectral irradiance results to be lineal in the interval from 160 to 2300 mJ/cm 2 . The obtained results when studying the TL properties of ZrO 2 : Cu exposed to the ultraviolet radiation show that it gathers dosimetric characteristics prominent to be used as an ultraviolet radiation dosemeter. (Author)

  8. TL and LOE dosimetric evaluation of diamond films exposed to beta and ultraviolet radiation

    International Nuclear Information System (INIS)

    Preciado F, S.; Melendrez, R.; Chernov, V.; Barboza F, M.; Schreck, M.; Cruz Z, E.

    2005-01-01

    The diamond possesses a privileged position regarding other materials of great technological importance. Their applications go from the optics, microelectronics, metals industry, medicine and of course as dosemeter, in the registration and detection of ionizing and non ionizing radiation. In this work the results of TL/LOE obtained in two samples of diamond of 10 μm thickness grown by the chemical vapor deposition method (CVD) assisted by microwave plasma. The films were deposited in a silicon substrate (001) starting from a mixture of gases composed of CH 4 /H 2 and 750 ppm of molecular nitrogen as dopant. The samples were exposed to beta radiation (Sr 90 / Y 90 ) and ultraviolet, being stimulated later on thermal (TL) and optically (LOE) to evaluate their dosimetric properties. The sample without doping presented high response TL/LOE to the ultraviolet and beta radiation. The TL glow curve of the sample without doping showed two TL peaks with second order kinetics in the range of 520 to 550 K, besides a peak with first order kinetics of more intensity around 607 K. The TL efficiency of the non doped sample is bigger than the doped with nitrogen; however the LOE efficiency is similar in both samples. The results indicate that the CVD diamond possesses excellent perspectives for dosimetric applications, with special importance in radiotherapy due to it is biologically compatible with the human tissue. (Author)

  9. The effect of solar ultraviolet radiation (UVR on induction of skin cancers

    Directory of Open Access Journals (Sweden)

    Marta Pacholczyk

    2016-04-01

    Full Text Available Ultraviolet radiation is a physical mutagenic and cancerogenic factor. About 95% of ultraviolet A (UVA (320–400 nm and 5% of UVB (280–320 nm reach the Earth’s surface. Melanin is a natural skin protective factor against UV radiation. Skin cancers associated with long-term exposure to UV radiation are: basal cell carcinoma (BCC, squamous cell carcinoma (SCC and cutaneous malignant melanoma (CMM. The high risk of BCC development is related to acute and repeated exposure to UV causing sunburn. Molecular studies of BBC demonstrated disorders in sonic hedgehog (SHH cell signaling regulation pathway, associated with the suppressor protein patched homolog 1 gene (PTCH1 mutations. The risk of the BCC development is related to the polymorphism of melanokortin-1 receptor gene (MC1R. Tumor P53 gene mutations observed in BCC cells has been classified as secondary genetic changes. In SCC cells UV-induced mutations were mostly related to P53 gene. Increased expression of cyclooxigenase- 2 gene (COX-2 plays a significant role in the development of SCC. Other pathogenetic factors include intensification of the synthesis of pro-inflammatory cytokines (tumor necrosis factor α (TNF-α, interleukin-1 α (IL-1α, IL-1β and IL-6. Currently, the role of UVB has been recognized in the pathogenesis of CMM. In CMM cells the following gene mutations were noted: cyclindependent kinase inhibitor 2A INK4A (p16INK4A, cyclin-dependent kinase 4 (CDK4, Ras, phosphatase and tensin homolog deleted on chromosome 10 (PTEN and proto-oncogene B-Raf (BRAF. The BRAF gene mutations were observed in ~50% of CMM cases. Mutations of P53 gene are not characteristic of CMM cells. Med Pr 2016;67(2:255–266

  10. Performance of a high resolution monochromator for the vacuum ultraviolet radiation from the DORIS storage ring

    International Nuclear Information System (INIS)

    Saile, V.; Skibowski, M.; Steinmann, W.; Guertler, P.; Koch, E.E.; Kozevnikov, A.

    1976-03-01

    The unique properties of the DORIS storage ring at DESY as a synchrotron radiation source are exploited for high resolution spectroscopy in the vacuum ultraviolet. We describe a new experimental set up with a 3 meter normal incidence monochromator for wavelengths between 3,000 A to 300 A (4 [de

  11. Ultra-violet radiation is responsible for the differences in global epidemiology of chickenpox and the evolution of varicella-zoster virus as man migrated out of Africa.

    Science.gov (United States)

    Rice, Philip S

    2011-04-23

    Of the eight human herpes viruses, varicella-zoster virus, which causes chickenpox and zoster, has a unique epidemiology. Primary infection is much less common in children in the tropics compared with temperate areas. This results in increased adult susceptibility causing outbreaks, for example in health-care workers migrating from tropical to temperate countries. The recent demonstration that there are different genotypes of varicella-zoster virus and their geographic segregation into tropical and temperate areas suggests a distinct, yet previously unconsidered climatic factor may be responsible for both the clinical and molecular epidemiological features of this virus infection. Unlike other human herpes viruses, varicella-zoster virus does not require intimate contact for infection to occur indicating that transmission may be interrupted by a geographically restricted climatic factor. The factor with the largest difference between tropical and temperate zones is ultra-violet radiation. This could reduce the infectiousness of chickenpox cases by inactivating virus in vesicles, before or after rupture. This would explain decreased transmissibility in the tropics and why the peak chickenpox incidence in temperate zones occurs during winter and spring, when ultra-violet radiation is at its lowest. The evolution of geographically restricted genotypes is also explained by ultra-violet radiation driving natural selection of different virus genotypes with varying degrees of resistance to inactivation, tropical genotypes being the most resistant. Consequently, temperate viruses should be more sensitive to its effects. This is supported by the observation that temperate genotypes are found in the tropics only in specific circumstances, namely where ultra-violet radiation has either been excluded or significantly reduced in intensity. The hypothesis is testable by exposing different virus genotypes to ultra-violet radiation and quantifying virus survival by plaque forming

  12. Data on solar sunburning ultraviolet (UVB radiation at an urban Mediterranean climate

    Directory of Open Access Journals (Sweden)

    Katerina G. Pantavou

    2017-04-01

    Full Text Available This article describes data on the intensity of ultraviolet B (UVB radiation collected during field questionnaire-based surveys in Athens, Greece. The surveys were conducted over 11 days of July and October 2010 at three different urban, outdoor sites. A total of 1104 interviews were conducted. The participants were asked to report whether they felt they got a sunburn at the moment of the interview. Questions related to personal characteristics including skin type and exposure time (visit duration at the interview site were also included in the questionnaire.

  13. Mechanisms of plant resistance to increased solar ultraviolet-B radiation. Final report

    International Nuclear Information System (INIS)

    Teramura, A.H.; Sullivan, J.H.

    1988-05-01

    Since the major conclusions of the project are being disseminated via the scientific literature, the final report consists of a compilation of 11 articles and manuscripts on the effects of ultraviolet-B radiation (UVB) on soybean growth and yield, stress interactions with UVB, and effects of UVB on seedling growth in conifers (the Pinaceae). The effects of UVB on soybeans under field and greenhouse conditions, and under water stress, drought stress and phosphorus deficiency were studied. Soybean yields, seed quality, and physiology, including seed fatty acid and sterol composition, were determined

  14. Equilibrium properties of blackbody radiation with an ultraviolet energy cut-off

    Science.gov (United States)

    Mishra, Dheeraj Kumar; Chandra, Nitin; Vaibhav, Vinay

    2017-10-01

    We study various equilibrium thermodynamic properties of blackbody radiation (i.e. a photon gas) with an ultraviolet energy cut-off. We find that the energy density, specific heat etc. follow usual acoustic phonon dynamics as have been well studied by Debye. Other thermodynamic quantities like pressure, entropy etc. have also been calculated. The usual Stefan-Boltzmann law gets modified. We observe that the values of the thermodynamic quantities with the energy cut-off is lower than the corresponding values in the theory without any such scale. The phase-space measure is also expected to get modified for an exotic spacetime appearing at Planck scale, which in turn leads to the modification of Planck energy density distribution and the Wien's displacement law. We found that the non-perturbative nature of the thermodynamic quantities in the SR limit (for both unmodified and modified cases), due to nonanalyticity of the leading term, is a general feature of the theory accompanied with an ultraviolet energy cut-off. We have also discussed the possible modification in the case of Big Bang and the Stellar objects and have suggested a table top experiment for verification in effective low energy case.

  15. DNA Repair and Photoprotection: Mechanisms of Overcoming Environmental Ultraviolet Radiation Exposure in Halophilic Archaea

    OpenAIRE

    Daniel L. Jones; Bonnie K. Baxter

    2017-01-01

    Halophilic archaea push the limits of life at several extremes. In particular, they are noted for their biochemical strategies in dealing with osmotic stress, low water activity and cycles of desiccation in their hypersaline environments. Another feature common to their habitats is intense ultraviolet (UV) radiation, which is a challenge that microorganisms must overcome. The consequences of high UV exposure include DNA lesions arising directly from bond rearrangement of adjacent bipyrimidine...

  16. The role of solar ultraviolet radiation in 'natural' water purification

    International Nuclear Information System (INIS)

    Calkins, J.; Buckles, J.D.; Moeller, J.R.

    1976-01-01

    The concentration of Eschericia coli in the input and output of a tertiary wastewater system (4 lagoons) has been monitored over an 11 month period. The integrated flux of biologically active solar ultraviolet (UV) radiation was measured during this period. By also determining (1) the effective temperature in the system, (2) the growth rate of E.coli at the effective temperature, (3) the penetration of the solar UV into the lagoons, (4) the dose-response relation for killing of E.coli by UV and (5) the retention time of water in the system, it is possible to compare the 'die off' expected from solar UV exposure to the actual 'die off' observed for different batches of water. The observed killing of E.coli was quite close to the values calculated, considering the numerous factors involved. Solar UV light would thus seem to be a very important factor in the natural purification of water. Because each successful species must possess characteristics (physiological or behavioral) which provide adequate resistance to solar UV, the ecological role of solar UV radiation has not been widely appreciated. (author)

  17. Monitoring the consequences of decreased ozone protection: The NSF ultraviolet radiation monitoring network

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The effects of decreased protection from ultraviolet radiation are as troubling as the continuing depletion of stratospheric ozone. Evidence exists to clearly link ozone depletion to changes in the antarctic marine environment. Results of two 1992 papers are summarized here. Enhanced exposure to mid-range UV radiation was found to be affecting marine ecosystems with a recorded 6-12 percent reduction in primary productivity directly related to the ozone layer depletion. In another experiment, a model was developed indicating that the ozone hole could reduce near-surface photosynthesis by as much as 12-15 percent. The NSF UV monitoring system in place for these and other experiments uses a spectroradiometer, making hourly, high-resolution measurements of the distribution of UV surface irradiance

  18. Vulnerability and behavioral response to ultraviolet radiation in the components of a foliar mite prey-predator system

    Science.gov (United States)

    Tachi, Fuyuki; Osakabe, Masahiro

    2012-12-01

    Ambient ultraviolet-B (UVB) radiation impacts plant-dwelling arthropods including herbivorous and predatory mites. However, the effects of UVB on prey-predator systems, such as that between the herbivorous spider mite and predatory phytoseiid mite, are poorly understood. A comparative study was conducted to determine the vulnerability and behavioral responses of these mites to ultraviolet (UV) radiation. First, we analyzed dose-response (cumulative irradiance-mortality) curves for the eggs of phytoseiid mites ( Neoseiulus californicus, Neoseiulus womersleyi, and Phytoseiulus persimilis) and the spider mite ( Tetranychus urticae) to UVB radiation from a UV lamp. This indicated that the phytoseiid mites were more vulnerable than the spider mite, although P. persimilis was slightly more tolerant than the other two phytoseiid mites. Second, we compared the avoidance behavior of adult female N. californicus and two spider mite species ( T. urticae, a lower leaf surface user; Panonychus citri, an upper leaf surface user) in response to solar UV and visible light. N. californicus actively avoided both types of radiation, whereas P. citri showed only minimal avoidance behavior. T. urticae actively avoided UV as well as N. californicus but exhibited a slow response to visible light as well as P. citri. Such variation in vulnerability and avoidance behavior accounts for differences in the species adaptations to solar UVB radiation. This may be the primary factor determining habitat use among these mites on host plant leaves, subsequently affecting accessibility by predators and also intraguild competition.

  19. DNA Damage and Repair in Plants under Ultraviolet and Ionizing Radiations

    Science.gov (United States)

    Gill, Sarvajeet S.; Gill, Ritu; Jha, Manoranjan; Tuteja, Narendra

    2015-01-01

    Being sessile, plants are continuously exposed to DNA-damaging agents present in the environment such as ultraviolet (UV) and ionizing radiations (IR). Sunlight acts as an energy source for photosynthetic plants; hence, avoidance of UV radiations (namely, UV-A, 315–400 nm; UV-B, 280–315 nm; and UV-C, important target for UV-B induced damage. On the other hand, IR causes water radiolysis, which generates highly reactive hydroxyl radicals (OH•) and causes radiogenic damage to important cellular components. However, to maintain genomic integrity under UV/IR exposure, plants make use of several DNA repair mechanisms. In the light of recent breakthrough, the current minireview (a) introduces UV/IR and overviews UV/IR-mediated DNA damage products and (b) critically discusses the biochemistry and genetics of major pathways responsible for the repair of UV/IR-accrued DNA damage. The outcome of the discussion may be helpful in devising future research in the current context. PMID:25729769

  20. Target and Non-target metabolomics profiling of different barley varieties affected by enhanced ultraviolet radiation and various C:N stoichiometry

    Czech Academy of Sciences Publication Activity Database

    Oravec, Michal; Novotná, Kateřina; Rajsnerová, P.; Veselá, B.; Urban, Otmar; Holub, Petr; Klem, Karel

    2015-01-01

    Roč. 29, č. 1 (2015), s. 887.7 ISSN 0892-6638 Institutional support: RVO:67179843 Keywords : metabolomic profiling * different barley varieties * ultraviolet radiation Subject RIV: EH - Ecology, Behaviour

  1. Maximum in the middle: nonlinear response of microbial plankton to ultraviolet radiation and phosphorus.

    Science.gov (United States)

    Medina-Sánchez, Juan Manuel; Delgado-Molina, José Antonio; Bratbak, Gunnar; Bullejos, Francisco José; Villar-Argaiz, Manuel; Carrillo, Presentación

    2013-01-01

    The responses of heterotrophic microbial food webs (HMFW) to the joint action of abiotic stressors related to global change have been studied in an oligotrophic high-mountain lake. A 2×5 factorial design field experiment performed with large mesocosms for >2 months was used to quantify the dynamics of the entire HMFW (bacteria, heterotrophic nanoflagellates, ciliates, and viruses) after an experimental P-enrichment gradient which approximated or surpassed current atmospheric P pulses in the presence vs. absence of ultraviolet radiation. HMFW underwent a mid-term (ultraviolet radiation. However, after depletion of dissolved inorganic P, the HMFW collapsed and was outcompeted by a low-diversity autotrophic compartment, which constrained the development of HMFW and caused a significant loss of functional biodiversity. The dynamics and relationships among variables, and the response patterns found, suggest the importance of biotic interactions (predation/parasitism and competition) in restricting HMFW development, in contrast to the role of abiotic factors as main drivers of autotrophic compartment. The response of HMFW may contribute to ecosystem resilience by favoring the maintenance of the peculiar paths of energy and nutrient-mobilization in these pristine ecosystems, which are vulnerable to threats by the joint action of abiotic stressors related to global change.

  2. Enhanced metastatic potential of murine fibrosarcomas treated in vitro with ultraviolet radiation

    International Nuclear Information System (INIS)

    Fisher, M.S.; Cifone, M.A.

    1981-01-01

    The purpose of this study was to determine whether repeated treatment of tumor cells in vitro with mutagenic doses of ultraviolet (UV) radiation could influence the metastatic behavior of these cells in vivo. Three cloned lines of UV-2237, a fibrosarcoma induced in a C3H- mouse by chronic irradiation with UV, and SF-19, a spontaneous C3H- fibrosarcoma, were grown in culture. These cell lines varied from low to high metastatic potential as determined by in vivo tests. The cultures were exposed to UV radiation from an FS40 sunlamp at a dose that killed 40% of the cells. These UV radiation exposures were repeated at 3- to 5-day intervals for a total of 5 treatments. The mutation frequency was analyzed by monitoring the appearance of ouabain-resistant colonies following UV irradiation. With all four tumor lines, the frequency of conversion to ouabain resistance was increased more than 10-fold. Tumor cells given 5 UV radiation treatments and control cultures carried in parallel without exposure to UV radiation were tested for metastatic potential in an in vivo lung colony assay. Cell lines treated in vitro with UV radiation produced more experimental metastases than the counterpart unirradiated cultures. We conclude that, in all four tumor lines, exposure of tumorigenic cells to mutagenic doses of UV radiation can alter their biological behavior and that this may contribute to the progression of tumors from low to high metastatic capability

  3. Soybean growth responses to enhanced levels of ultraviolet-B radiation under greenhouse conditions

    International Nuclear Information System (INIS)

    Teramura, A.H.; Sullivan, J.H.

    1987-01-01

    Soybean (Glycine max [L.] Merr. cv. Essex) was grown in an unshaded greenhouse under three levels of biologically effective ultraviolet-B (UV-BBE) radiation (effective daily dose: 0, 11.5 and 13.6 kJ m -2 ) for 91 days. Plants were harvested at regular intervals beginning 10 days after germination until reproductive maturity. Mathematical growth analysis revealed that the effects of UV-B radiation varied with plant growth stage. The transition period between vegetative and reproductive growth was the most sensitive to UV-B radiation. Intermediate levels of UV-B had deleterious effects on plant height, leaf area, and total plant dry weight at late vegetative and reproductive stages of development. Specific leaf weight increased during vegetative growth but was unaffected by UV-B during reproductive growth stages. Relative growth, net assimilation, and stem elongation rates were decreased by UV-B radiation during vegetative and early reproductive growth stages. Variation in plant responses may be due in part to changes in microclimate within the plant canopy or to differences in repair or protection mechanisms at differing developmental stages. (author)

  4. Impact of shortwave ultraviolet (UV-C) radiation on the antioxidant activity of thyme (Thymus vulgaris L.).

    Science.gov (United States)

    Dogu-Baykut, Esra; Gunes, Gurbuz; Decker, Eric Andrew

    2014-08-15

    Thyme is a good source of antioxidant compounds but it can be contaminated by microorganisms. An experimental fluid bed ultraviolet (UV) reactor was designed for microbial decontamination of thyme samples and the effect of shortwave ultraviolet light (UV-C) radiation on antioxidant properties of thyme was studied. Samples were exposed to UV-C radiation for 16 or 64 min. UV-C treatment led to 1.04 and 1.38 log CFU/g reduction of total aerobic mesophilic bacteria (TAMB) counts. Hunter a(∗) value was the most sensitive colour parameter during UV-C treatment. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of extracts was not significantly affected by UV-C. Addition of thyme extracts at 0.15 and 0.3 μmol GAE/ml emulsion delayed the formation of lipid hydroperoxides and headspace hexanal in the 5.0%(wt) corn oil-in-water emulsion from 4 to 9 and 14 days, respectively. No significant changes in oxidation rates were observed between UV-C treated and untreated samples at same concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Effects of the ultraviolet-B radiation (UV-B) on conifers: a review

    International Nuclear Information System (INIS)

    Laakso, K.; Huttunen, S.

    1998-01-01

    The current knowledge on conifer responses to enhanced ultraviolet-B (UV-B) radiation is mainly based on greenhouse or growth chamber experiments of one growing season in duration. However, the biomass losses observed in greenhouses do not occur in field-grown trees in their natural habitats. Moreover, the majority of the 20 conifer species studied have been 1-year-old seedlings, and no studies have been undertaken on mature trees. Fully grown needles, with their glaucous waxy surfaces and thick epidermal cells with both soluble and wall-bound UV-B screening metabolites, are well protected against UV-B radiation. However, it is not known whether these are sufficient protectants in young emerging needles or during the early spring period of high UV-B levels reflected from snow. In order to understand all the mechanisms that result in the protection of conifer needles against UV-B radiation, future research should focus on the epidermal layer, separating the waxes, cuticle and epidermal and hypodermal cells. Parallel studies should consist of wall-bound and soluble secondary metabolite analysis, antioxidant measurements and microscopic observations. (author)

  6. ASSESSMENT OF THE RISK OF SOLAR ULTRAVIOLET RADIATION TO AMPHIBIANS: III. PREDICTION OF IMPACTS IN SELECTED NORTHERN MIDWESTERN WETLANDS

    Science.gov (United States)

    The deleterious effects of solar ultraviolet radiation, especially the UV-B portion of sunlight, have been hypothesized to reduce survival, increase the frequency of malformations, and contribute to the apparent worldwide decline of many amphibian species.

  7. Solar ultraviolet radiation measurements at South African and Reunion Island Coastal Sites: An indicator of public sun protection

    CSIR Research Space (South Africa)

    Wright, CY

    2013-09-01

    Full Text Available Solar ultraviolet radiation (UVR) has the potential to cause biological harm to humans. Intensity of solar UVR at the Earth’s surface depends on several factors, such as total column ozone and cloud cover, and temporal trends are usually dependent...

  8. Alteration in expression of defence genes in Pisum sativum after exposure to supplementary ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Strid, A.

    1993-01-01

    Alterations in the amounts of mRNA for different types of defence genes after exposure of peas to supplementary ultraviolet-B radiation are demonstrated. The expression of the genes which encode the chalcone synthase of the flavonoid biosynthetic pathway and glutathione reductase was induced, while a decrease was found for the chloroplastic radical-scavenging enzyme, superoxide dismutase. (author)

  9. Induction of prophages in spores of Bacillus subtilis by ultraviolet irradiation from synchrotron orbital radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sadaie, Y.; Kada, T.; Ohta, Y. (National Inst. of Genetics, Mishima, Shizuoka (Japan)); Kobayashi, K.; Hieda, K.; Ito, T.

    1984-06-01

    Prophages were induced from Bacillus subtilis spores lysogenic with SP02 by ultraviolet (160 nm to 240 nm) irradiation from synchrotron orbital radiation (SR UV). SR UV at around 220 nm was most effective in the inactivation of spores and prophage induction from lysogenic spores, suggesting that the lesions are produced on the DNA molecule which eventually induces signals to inactivate the phage repressor.

  10. Induction of prophages in spores of Bacillus subtilis by ultraviolet irradiation from synchrotron orbital radiation

    International Nuclear Information System (INIS)

    Sadaie, Y.; Kada, T.; Ohta, Y.; Kobayashi, K.; Hieda, K.; Ito, T.

    1984-01-01

    Prophages were induced from Bacillus subtilis spores lysogenic with SP02 by ultraviolet (160 nm to 240 nm) irradiation from synchrotron orbital radiation (SR UV). SR UV at around 220 nm was most effective in the inactivation of spores and prophage induction from lysogenic spores, suggesting that the lesions are produced on the DNA molecule which eventually induces signals to inactivate the phage repressor. (author)

  11. The Role of Ultraviolet Radiation in the Ocular System of  Mammals

    Directory of Open Access Journals (Sweden)

    Mercede Majdi

    2014-10-01

    Full Text Available With decreasing levels of ozone in the atmosphere, we are being exposed to higher levels of ultraviolet radiation (UVR than ever before. UVR carries higher energy than visible light, and its effects on tissues include DNA damage, gene mutations, immunosuppression, oxidative stress and inflammatory responses. In the eye, UVR is strongly associated with the development of basal and squamous cell carcinoma of the eyelid, pterygium, photokeratitis, climatic droplet keratopathy, ocular surface squamous neoplasia, cataracts, and uveal melanoma, and is weakly associated with age-related macular degeneration. Despite overwhelming evidence regarding the deleterious effects on UVR, public health measures to encourage UV protection of the eyes is generally lacking. Options for photoprotection include sunglasses, wide brim hats, windshields, plastic films for side windows in cars, UV blocking contact lenses, and following the UV Index report daily. The American National Standards Institute currently has regulations regarding properties of UV blocking sunglasses; however, compliance in the US is not mandatory. On the other hand, UVR does have therapeutic applications in the eye, particularly, riboflavin activated by ultraviolet A light (UVA radiation is used clinically to slow the progression of keratoconus, post-LASIK keratectasia, and bullous keratopathy by crosslinking corneal collagen fibers. Additionally, riboflavin activated by UVA has been shown to have antibacterial, antiviral, and antiparasitic effects. This is clinically relevant in the treatment of infectious keratitis. Finally, exposure to low levels of light in the UV spectrum has been found to regulate the growth of the eye and lack of adequate exposure may increase the risk of development and progression of myopia.

  12. Continuous wave ultraviolet radiation induced frustration of etching in lithium niobate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Mailis, S.; Riziotis, C.; Smith, P.G.R.; Scott, J.G.; Eason, R.W

    2003-02-15

    Illumination of the -z face of congruent lithium niobate single crystals with continuous wave (c.w.) ultraviolet (UV) laser radiation modifies the response of the surface to subsequent acid etching. A frequency doubled Ar{sup +} laser ({lambda}=244 nm) was used to illuminate the -z crystal face making it resistive to HF etching and thus transforming the illuminated tracks into ridge structures. This process enables the fabrication of relief patterns in a photolithographic manner. Spatially resolved Raman spectroscopy indicates preservation of the good crystal quality after irradiation.

  13. 21 CFR 878.4635 - Ultraviolet lamp for tanning.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet lamp for tanning. 878.4635 Section 878... tanning. (a) Identification. An ultraviolet lamp for tanning is a device that is a lamp (including a fixture) intended to provide ultraviolet radiation to tan the skin. See § 1040.20 of this chapter. (b...

  14. Both near ultraviolet radiation and the oxidizing agent hydrogen peroxide induce a 32-kDa stress protein in normal human skin fibroblasts

    International Nuclear Information System (INIS)

    Keyse, S.M.; Tyrrell, R.M.

    1987-01-01

    We have analyzed the pattern of protein synthesis in solar near ultraviolet (334 nm, 365 nm) and near visible (405 nm) irradiated normal human skin fibroblasts. Two hours after irradiation we find that one major stress protein of approximately 32 kDa is induced in irradiated cells. This protein is not induced by ultraviolet radiation at wavelengths shorter than 334 nm and is not inducible by heat shock treatment of these cells. Although sodium arsenite, diamide, and menadione all induced a 32-kDa protein, they also induced the major heat shock proteins. In contrast, the oxidizing agent, hydrogen peroxide, induced the low molecular weight stress protein without causing induction of the major heat shock proteins. A comparison of the 32-kDa proteins induced by sodium arsenite, H 2 O 2 , and solar near ultraviolet radiation using chemical peptide mapping shows that they are closely related. These results imply that the pathways for induction of the heat shock response and the 32-kDa protein are not identical and suggest that, at least in the case of radiation and treatment with H 2 O 2 , the 32-kDa protein might be induced in response to cellular oxidative stress. This conclusion is supported by the observation that depletion of endogenous cellular glutathione prior to solar near ultraviolet irradiation lowers the fluence threshold for induction of the 32-kDa stress protein

  15. Clinical evaluation of direct and photosensitized ultraviolet radiation damage to the lens

    International Nuclear Information System (INIS)

    Hockwin, O.; Lerman, S.

    1982-01-01

    We are reporting a new, objective, and quantitative method for monitoring age-related molecular changes in the human ocular lens in vivo, as expressed by increases in at least two (nontryptophan) fluorescence wavelengths. These fluorescence wavelengths appear to be caused by photochemically induced changes in the lens, and they reflect the ultraviolet (UV) filtering capacity of the patients' ocular lenses. These data correlate with previously reported in vitro lens fluorescence changes that are associated with the aging process. This method will also detect alterations in lenticular fluorescence caused by photosensitized as well as direct UV radiation damage

  16. DNA excision repair in human cells treated with ultraviolet radiation and 7,12-dimethylbenz(a)anthracene 5,6-oxide

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, F.E.; Gentil, A.; Renstein, B.S.; Setlow, R.B.

    1980-01-01

    Excision repair was measured in normal human and xeroderma pigmentosum group C cells treated with 7,12-dimethylbenz(a)anthracene 5,6-oxide and with ultraviolet radiation by the techniques of unscheduled DNA synthesis, repair replication, a modification and bromodeoxyuridine photolysis and endonuclease-sensitive sites assay. Radiautography and repair replication showed that in normal cells the magnitude of repair after a saturation dose of the epoxide to be 0.1 to 0.2, that after a saturating ultraviolet dose, though survival data showed that both doses gave nearly similar killings. Repair was of the long-patch type and repair kinetics after the epoxide treatment were similar to ultraviolet. After a combined treatment with both agents, unscheduled synthesis in normal cells was more than additive. The data indicate that there are different rate-limiting steps in the removal of the ultraviolet and the epoxide damages, and that the residual repair activity in xeroderma pigmentosum cells is accomplished by different, not just fewer, enzymes than in normal cells.

  17. The effects of ultraviolet radiation on the planktonic community of a shallow, eutrophic estuary: results of mesocosm experiments

    NARCIS (Netherlands)

    Forster, R.M.; Schubert, H.

    2001-01-01

    This paper describes the results of pelagic mesocosm experiments designed to test the effects of enhanced and reduced ultraviolet radiation (UV) on the planktonic community of a Baltic Sea estuary. The Darss-Zingst estuary consists of a series of brackish lagoons with high concentrations of

  18. Effects of gamma rays, ultraviolet radiation, sunlight, microwaves and electromagnetic fields on gene expression mediated by human immunodeficiency virus promoter

    International Nuclear Information System (INIS)

    Libertin, C.R.; Woloschak, G.E.; Panozzo, J.; Groh, K.R.; Chang-Liu, Chin-Mei; Schreck, S.

    1994-01-01

    Previous work by our group and others has shown the modulation of human immunodeficiency virus (HIV) promoter or long terminal repeat (LTR) after exposure to neutrons and ultraviolet radiations. Using HeLa cells stably transfected with a construct containing the chloramphenicol acetyl transferase (CAT) gene, the transcription of which is mediated by the HIV-LTR, we designed experiments to examine the effects of exposure to different types of radiation (such as γ rays, ultraviolet and sunlight irradiations, electromagnetic fields and microwaves) in HIV-LTR-driven expression of CAT. These results demonstrated ultraviolet-light-induced transcription from the HIV promoter, as has been shown by others. Exposure to other DNA-damaging agents such as γ rays and sunlight (with limited exposures) had no significant effect on transcription mediated by HIV-LTR, suggesting that induction of HIV is not mediated by just any type of DNA damage but rather may require specific types of DNA damage. Microwaves did not cause cell killing when cells in culture were exposed in high volumes of medium, and the same cells showed no changes in expression. When microwave exposure was carried out in low volumes of medium (so that excessive heat was generated) induction of HIV-LTR transcription (as assayed by CAT activity) was evident. Electromagnetic field exposures had no effect on expression of HIV-LTR. These results demonstrate that not all types of radiation and not all DNA-damaging agents are capable of inducing HIV. We hypothesize that induction of HIV transcription may be mediated by several different signals exposure to radiation. 22 refs., 8 figs

  19. The effects of ultraviolet-A radiation on visual evoked potentials in the young human eye

    International Nuclear Information System (INIS)

    Sanford, B.E.; Beacham, S.; Hanifin, J.P.; Hannon, P.; Streletz, L.; Sliney, D.; Brainard, G.C.

    1996-01-01

    A recent study from this laboratory using visual evoked potentials (VEPs) demonstrated that children's eyes are capable of detecting ultraviolet radiation. The aim of this study was to compare dose-response relationships in two age groups, 6-10 years (n=10) and 20-25 years (n=10). Under photopic viewing conditions (550 lux), exposures of monochromatic UV-A (339 nm) and visible radiation (502 nm) were correlated to VEPs. The results demonstrate that monochromatic UV-A can elicit age and dose dependent responses in the human visual system, suggesting that the eyes of children are more responsive to UV stimuli than the eyes of young adults. (au) 17 refs

  20. Ultraviolet fire detector

    Science.gov (United States)

    Turnage, J. E.; Linford, R. M. F.; Cornish, S. D.

    1976-01-01

    System is capable of detecting ultraviolet light emitted by match size flame at distance of 10 ft. System is not affected by high energy or particulate radiation and is therefore particularly suited for applications around nuclear plants and X-ray equipment.

  1. Ultraviolet radiation-damage absorption peak in solid deuterium-tritium. Revision 1

    International Nuclear Information System (INIS)

    Fearon, E.M.; Tsugawa, R.T.; Souers, P.C.; Poll, J.D.; Hunt, J.L.

    1985-01-01

    An ultraviolet absorption peak has been seen in solid deuterium-tritium and hydrogen-tritium at a sensor temperature of 5 K. The peak occurs at 3.6 eV and is about 1.5 eV wide. It bleaches out when the temperature is raised to about 10 K but reappears upon cooling and is, therefore, radiation induced. At 5 K, the peak forms on a time scale of minutes and appears to represent part-per-million levels of electron-mass defects. The suggested model is that of a trapped electron, where the peak is the ground state-to-the-conduction band transition. A marked isotope effect is seen between D-T and H-T

  2. Medical Devices; General Hospital and Personal Use Devices; Classification of the Ultraviolet Radiation Chamber Disinfection Device. Final order.

    Science.gov (United States)

    2015-11-20

    The Food and Drug Administration (FDA or the Agency) is classifying the ultraviolet (UV) radiation chamber disinfection device into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the UV radiation chamber disinfection device classification. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  3. Optical effects of exposing intact human lenses to ultraviolet radiation and visible light

    DEFF Research Database (Denmark)

    Kessel, Line; Eskildsen, Lars; Lundeman, Jesper Holm

    2011-01-01

    region of incoming visible light. The aim of the present study was to examine the optical effects on human lenses of short wavelength visible light and ultraviolet radiation. METHODS: Naturally aged human donor lenses were irradiated with UVA (355 nm), violet (400 and 405 nm) and green (532 nm) lasers......: Irradiation with high intensity lasers caused scattering lesions in the human lenses. These effects were more likely to be seen when using pulsed lasers because of the high pulse intensity. Prolonged irradiation with UVA led to photodarkening whereas no detrimental effects were observed after irradiation...

  4. Optical effects of exposing intact human lenses to ultraviolet radiation and visible light

    DEFF Research Database (Denmark)

    Kessel, Line; Eskildsen, Lars Baunsgaard; Lundeman, Jesper Holm

    2011-01-01

    wavelength region of incoming visible light. The aim of the present study was to examine the optical effects on human lenses of short wavelength visible light and ultraviolet radiation. METHODS: Naturally aged human donor lenses were irradiated with UVA (355 nm), violet (400 and 405 nm) and green (532 nm....... RESULTS: Irradiation with high intensity lasers caused scattering lesions in the human lenses. These effects were more likely to be seen when using pulsed lasers because of the high pulse intensity. Prolonged irradiation with UVA led to photodarkening whereas no detrimental effects were observed after...

  5. Maximum in the middle: nonlinear response of microbial plankton to ultraviolet radiation and phosphorus.

    Directory of Open Access Journals (Sweden)

    Juan Manuel Medina-Sánchez

    Full Text Available The responses of heterotrophic microbial food webs (HMFW to the joint action of abiotic stressors related to global change have been studied in an oligotrophic high-mountain lake. A 2×5 factorial design field experiment performed with large mesocosms for >2 months was used to quantify the dynamics of the entire HMFW (bacteria, heterotrophic nanoflagellates, ciliates, and viruses after an experimental P-enrichment gradient which approximated or surpassed current atmospheric P pulses in the presence vs. absence of ultraviolet radiation. HMFW underwent a mid-term (<20 days acute development following a noticeable unimodal response to P enrichment, which peaked at intermediate P-enrichment levels and, unexpectedly, was more accentuated under ultraviolet radiation. However, after depletion of dissolved inorganic P, the HMFW collapsed and was outcompeted by a low-diversity autotrophic compartment, which constrained the development of HMFW and caused a significant loss of functional biodiversity. The dynamics and relationships among variables, and the response patterns found, suggest the importance of biotic interactions (predation/parasitism and competition in restricting HMFW development, in contrast to the role of abiotic factors as main drivers of autotrophic compartment. The response of HMFW may contribute to ecosystem resilience by favoring the maintenance of the peculiar paths of energy and nutrient-mobilization in these pristine ecosystems, which are vulnerable to threats by the joint action of abiotic stressors related to global change.

  6. Skin cancer induced by ultraviolet radiation and immunity

    International Nuclear Information System (INIS)

    Sado, Toshihiko

    1977-01-01

    It was clarified that an immunological mechanism, in which the resistance against ultraviolet radiation (UV)-induced neoplasm with strong antigenicity in the body disappeared, was introduced, when the mouse was exposed to UV for two to five weeks. It was also suggested that the immunological mechanism was an induction of T lymphocyte (inhibitive T cells) which had a function to specifically inhibit proliferation of lymphocyte clone which had anti-UV-induced neoplasm activity contained in lymphocyte mass of normal mouse. It can be thought that the action mechanism of this cells may inhibit a process of differentiation of T precursor cells of cell damage, which has anti-UV-induced neoplasm activity, into cell damage T cells. As a mechanism in which such inhibitive T cells are induced, the possibility that specific inhibitive T cells against antigens which are changed by UV would be induced after proteins, which receives some changes in consequence of skin injuries due to UV, are separated from cells as soluble antigens, is thought. Reports of experiments on these problems performed by many researchers were also described. (Tsunoda, M.)

  7. Role of Ultraviolet Radiation in Papillomavirus-Induced Disease

    Science.gov (United States)

    Uberoi, Aayushi; Yoshida, Satoshi; Frazer, Ian H.; Pitot, Henry C.; Lambert, Paul F.

    2016-01-01

    Human papillomaviruses are causally associated with 5% of human cancers. The recent discovery of a papillomavirus (MmuPV1) that infects laboratory mice provides unique opportunities to study the life cycle and pathogenesis of papillomaviruses in the context of a genetically manipulatable host organism. To date, MmuPV1-induced disease has been found largely to be restricted to severely immunodeficient strains of mice. In this study, we report that ultraviolet radiation (UVR), specifically UVB spectra, causes wild-type strains of mice to become highly susceptible to MmuPV1-induced disease. MmuPV1-infected mice treated with UVB develop warts that progress to squamous cell carcinoma. Our studies further indicate that UVB induces systemic immunosuppression in mice that correlates with susceptibility to MmuPV1-associated disease. These findings provide new insight into how MmuPV1 can be used to study the life cycle of papillomaviruses and their role in carcinogenesis, the role of host immunity in controlling papillomavirus-associated pathogenesis, and a basis for understanding in part the role of UVR in promoting HPV infection in humans. PMID:27244228

  8. Ultraviolet-B radiation effects on phenolic profile and flavonoid content of Kalanchoe pinnata.

    Science.gov (United States)

    Nascimento, Luana Beatriz Dos Santos; Leal-Costa, Marcos Vinicius; Menezes, Eloá Aragão; Lopes, Virgínia Rodrigues; Muzitano, Michelle Frazão; Costa, Sônia Soares; Tavares, Eliana Schwartz

    2015-07-01

    Ultraviolet-B radiation is an important abiotic factor that can stimulate the production of secondary metabolites, including polyphenolic compounds. Kalanchoe pinnata (Crassulaceae) is a medicinal plant popularly used in Brazil for treating wounds and inflammation. This species is rich in phenolic compounds, which could account for some of its biological activities, including antileishmanial, antihypertensive and antibacterial properties. We investigated the effects of supplemental UV-B radiation on the phenolic profile, antioxidant activity and total flavonoid content of leaves of K. pinnata. Plants were grown under white light (W - control) and supplemental UV-B radiation (W+UVB). Supplemental UV-B radiation enhanced the total flavonoid content of the leaf extracts, without affecting the antioxidant activity or yield of extracts. Analysis by TLC and HPLC of W and W+UVB leaf extracts revealed quantitative and qualitative differences in their phenolic profiles. W+UVB extracts contained a higher diversity of phenolic compounds and a larger amount of quercitrin, an important bioactive flavonoid of this species. This is the first report of the use of ImageJ® program to analyze a TLC visualized by spraying with NP-PEG reagent. UV-B radiation is proposed as a supplemental light source in K. pinnata cultivation in order to improve its flavonoid composition. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. [Association between sunburn in children and ultraviolet radiation and ozone layer, during six summers (1996-2001) in Santiago, Chile (33,5 degrees S)].

    Science.gov (United States)

    Aranibar, Ligia; Cabrera, Sergio; Honeyman, Juan

    2003-09-01

    During the recent 10 years the ozone layer has decreased while ultraviolet radiation has increased in Santiago, Chile. To determine whether the number of sunburns in children correlate with ultraviolet radiation in Santiago. During six Austral Summers (1996-2001) children below 15 years old, consulting for sunburn, were evaluated at the "Corporation for the Aid of Burned Children" (COANIQUEM) in Santiago (33.5 degrees S). The number of children with sunburns during each Summer was compared with the corresponding UV-B radiation and the ozone thickness, to establish a probable relation between a geophysical change and its consequences in skin health. The ozone layer values were obtained from the NASA WEB-page and the ultraviolet radiation was measured with a four-channel medium resolution radiometer. In each Summer there was a predominance of sunburns among boys and among ages between 6 and 10 years. During the 96-97 Austral Summer, the highest number of children with sunburns (63) was diagnosed. That Summer also had the highest mean UV-305 nm radiation with an important amount of days with ozone Summer an inverse correlation between ozone and UV-305 nm radiation was detected. At the same time the maximal values of Erythemal Dose Rate (33 muWatt cm2), UV Index (13) and Erythemal Daily Dose (7.500 Joule m2) were observed. In Santiago, Summers with a higher number of days with low ozone protection seem to reappear every 3 years. Understanding the interaction of physical processes that control the ozone layer, may help to design better photo-protection programs for human health.

  10. Disinfection of drinking water by ultraviolet light

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    It is no longer mandatory that a given residue of chlorine is present in drinking water and this has led to interest in the use of ultraviolet radiation for disinfection of water in large public waterworks. After a brief discussion of the effect of ultraviolet radiation related to wavelength, the most usual type of irradiation equipment is briefly described. Practioal considerations regarding the installation, such as attenuation of the radiation due to water quality and deposits are presented. The requirements as to dose and residence time are also discussed and finally it is pointed out that hydraulic imperfections can reduce the effectiveness drastically. (JIW)Ψ

  11. Variation and Grey GM(1, 1) Prediction of Melting Peak Temperature of Polypropylene During Ultraviolet Radiation Aging

    Science.gov (United States)

    Chen, K.; Y Zhang, T.; Zhang, F.; Zhang, Z. R.

    2017-12-01

    Grey system theory regards uncertain system in which information is known partly and unknown partly as research object, extracts useful information from part known, and thereby revealing the potential variation rule of the system. In order to research the applicability of data-driven modelling method in melting peak temperature (T m) fitting and prediction of polypropylene (PP) during ultraviolet radiation aging, the T m of homo-polypropylene after different ultraviolet radiation exposure time investigated by differential scanning calorimeter was fitted and predicted by grey GM(1, 1) model based on grey system theory. The results show that the T m of PP declines with the prolong of aging time, and fitting and prediction equation obtained by grey GM(1, 1) model is T m = 166.567472exp(-0.00012t). Fitting effect of the above equation is excellent and the maximum relative error between prediction value and actual value of T m is 0.32%. Grey system theory needs less original data, has high prediction accuracy, and can be used to predict aging behaviour of PP.

  12. Action spectrum for inhibition by ultraviolet radiation of photosystem 2 activity in spinach thylakoids

    International Nuclear Information System (INIS)

    Bornman, J.F.; Bjoern, L.O.; Aakerlund, H.-E.

    1984-01-01

    The effect of ultraviolet (UV) radiation (half-band width 10 nm) in the wavelength range 248-340 nm on chlorophyll fluorescence from a thin layer of spinach thylakoid suspension was investigated. It was found that the parameter most sensitive to UV radiation was the rise time of variable fluorescence. The increase in rise time was proportional to UV photon fluence and was used for the determination of an action spectrum. The action spectrum falls off from a maximum at ca. 275 nm towards longer wavelengths and rises from a minimum at 260 nm towards shorter wavelengths. The results also suggest that the UV inhibition is mainly on the PS 2 oxidizing side. Possibly damage is also inflicted to the PS 2 reaction center. (orig.)

  13. Growth of antarctic cyanobacteria under ultraviolet radiation: UVA counteracts UVB inhibition

    International Nuclear Information System (INIS)

    Quesada, A.; Mouget, J.L.; Vincent, W.F.

    1995-01-01

    A mat-forming cyanobacterium (Phormidium murayi West and West) isolated from an ice-shelf pond in Antarctica was grown under white light combined with a range of UVA and UVB irradiance. The 4-day growth rate decreased under increasing ultraviolet (UV) radiation, with a ninefold greater response to UVB relative to UVA. In vivo absorbance spectra showed that UVA and to a greater extent UVB caused a decrease in phycocyanin/chlorophyll a and an increase in carotenoids/chlorophyll a. The phycocyanin/chlorophyll a ratio was closely and positively correlated to the UVB-inhibited growth rate. Under fixed spectral gradients of UV radiation, the growth inhibition effect was dominated by UVB. However, at specific UVB irradiances the inhibition of growth depended on the ratio of UVB to UVA, and growth rates increased linearly with increasing UVA. These results are consistent with the view that UVB inhibition represents the balance between damage and repair processes that are each controlled by separate wavebands. They also underscore the need to consider UV spectral balance in laboratory and field assays of UVB toxicity. 49 refs., 6 figs

  14. Lunar dusty plasma: A result of interaction of the solar wind flux and ultraviolet radiation with the lunar surface

    International Nuclear Information System (INIS)

    Lisin, E A; Tarakanov, V P; Petrov, O F; Popel, S I

    2015-01-01

    One of the main problems of future missions to the Moon is associated with lunar dust. Solar wind flux and ultraviolet radiation interact with the lunar surface. As a result, there is a substantial surface change and a near-surface plasma sheath. Dust particles from the lunar regolith, which turned in this plasma because of any mechanical processes, can levitate above the surface, forming dust clouds. In preparing of the space experiments “Luna-Glob” and “Luna-Resource” particle-in-cell calculations of the near-surface plasma sheath parameters are carried out. Here we present some new results of particle-in-cell simulation of the plasma sheath formed near the surface of the moon as a result of interaction of the solar wind and ultraviolet radiation with the lunar surface. The conditions of charging and stable levitation of dust particles in plasma above the lunar surface are also considered. (paper)

  15. Combined effects of copper and ultraviolet radiation on a microscopic green alga in natural soft lake waters of varying dissolved organic carbon content

    International Nuclear Information System (INIS)

    West, L. Jeanine A.; Li, Karen; Greenberg, Bruce M.; Mierle, Greg; Smith, Ralph E.H.

    2003-01-01

    Selenastrum capricornutum was grown in two lake waters of differing dissolved organic carbon content (1.8 vs. 9.1 mg DOC l -1 ) to determine the responses of population dynamics and photosynthesis to Cu, and to assess the modifying effects of varying ultraviolet radiation (UVR) exposure. In the absence of UVR, the mean EC 50 for Cu effect on population growth rate was 2.3-2.6 μg l -1 in the low DOC water and 17.4-26.2 μg l -1 in the high DOC water. The variable chlorophyll a fluorescence ratio, F v /F m , decreased approximately in parallel with the diminished growth rates. Exposure of the higher DOC lake water to full spectrum artificial radiation caused an increase of Cu 2+ concentration, compared to samples held in darkness or in photosynthetically active radiation (PAR) only. Full spectrum exposures also resulted in a lower (although not significantly so) EC 50 for Cu effect on growth rate, consistent with response to the moderately elevated Cu 2+ concentration. Cu 2+ concentration was unaffected by radiation exposure in the low DOC water, and EC 50 s for growth were also unaffected except in the most severe UVR treatment, which was >40% inhibited even in the absence of added Cu. Using F v /F m as an end-point, there was no evidence of interactions between UVR and Cu under the relatively low PAR exposures used here. Algal growth and photosynthesis was extremely sensitive to Cu in these soft lake waters, with EC 50 s close to current water quality standards in the low DOC water

  16. An integrated artificial neural networks approach for predicting global radiation

    International Nuclear Information System (INIS)

    Azadeh, A.; Maghsoudi, A.; Sohrabkhani, S.

    2009-01-01

    This article presents an integrated artificial neural network (ANN) approach for predicting solar global radiation by climatological variables. The integrated ANN trains and tests data with multi layer perceptron (MLP) approach which has the lowest mean absolute percentage error (MAPE). The proposed approach is particularly useful for locations where no available measurement equipment. Also, it considers all related climatological and meteorological parameters as input variables. To show the applicability and superiority of the integrated ANN approach, monthly data were collected for 6 years (1995-2000) in six nominal cities in Iran. Separate model for each city is considered and the quantity of solar global radiation in each city is calculated. Furthermore an integrated ANN model has been introduced for prediction of solar global radiation. The acquired results of the integrated model have shown high accuracy of about 94%. The results of the integrated model have been compared with traditional angstrom's model to show its considerable accuracy. Therefore, the proposed approach can be used as an efficient tool for prediction of solar radiation in the remote and rural locations with no direct measurement equipment.

  17. A model investigation of annual surface ultraviolet radiation in Iran

    International Nuclear Information System (INIS)

    Sabziparvar, A.-A.

    2003-01-01

    In recent years, there has been some concern regarding solar ultraviolet (UV) radiation received at the earth,s surface because of its biological hazards affecting living organisms. Although the geographical distribution of ground-based UV network is relatively good in some continents,but over Asia, the number of UV instruments are not sufficient for meteorological and biological purposes. Iran, as an Asian country, is also suffering from the lack of UV monitoring network with the exception of one ground-based UV spectrophotometer site (Brower III) at Esfahan. Using a complex radiative transfer model and various meteorological data (for 8 years) such as total column ozone, cloudiness, surface albedo, surface air pressure, relative humidity, visibility and daily total solar radiation (TSR), the geographical distribution of annual integrated biological surface UV irradiances such as UVB, erythema and cataracts are calculated. The comparison is made for cloud-free and all-sky conditions for eight selected cities distributed from the southern tip of the country (25 N-60 E) to the northern border (39 N-48 E). It is shown that the difference between the annual UV at south and north in all-sky condition is larger than the differences in cloud-free condition. The ratio of some biological UV irradiances at southern cities to the same component at northern cities shows a factor of two and more which is quite significant. The possible reasons which might cause such differences are discussed

  18. Synchrotron Vacuum Ultraviolet Light and Soft X-Ray Radiation Effects on Aluminized Teflon FEP Investigated

    Science.gov (United States)

    Dever, Joyce A.; Townsend, Jacqueline A.; Gaier, James R.; Jalics, Alice I.

    1999-01-01

    Since the Hubble Space Telescope (HST) was deployed in low Earth orbit in April 1990, two servicing missions have been conducted to upgrade its scientific capabilities. Minor cracking of second-surface metalized Teflon FEP (DuPont; fluorinated ethylene propylene) surfaces from multilayer insulation (MLI) was first observed upon close examination of samples with high solar exposure retrieved during the first servicing mission, which was conducted 3.6 years after deployment. During the second HST servicing mission, 6.8 years after deployment, astronaut observations and photographic documentation revealed significant cracks in the Teflon FEP layer of the MLI on both the solar- and anti-solar-facing surfaces of the telescope. NASA Goddard Space Flight Center directed the efforts of the Hubble Space Telescope MLI Failure Review Board, whose goals included identifying the low-Earth-orbit environmental constituent(s) responsible for the cracking and embrittling of Teflon FEP which was observed during the second servicing mission. The NASA Lewis Research Center provided significant support to this effort. Because soft x-ray radiation from solar flares had been considered as a possible cause for the degradation of the mechanical properties of Teflon FEP (ref. 1), the effects of soft xray radiation and vacuum ultraviolet light on Teflon FEP were investigated. In this Lewisled effort, samples of Teflon FEP with a 100-nm layer of vapor-deposited aluminum (VDA) on the backside were exposed to synchrotron radiation of various vacuum ultraviolet and soft x-ray wavelengths between 18 nm (69 eV) and 0.65 nm (1900 eV). Synchrotron radiation exposures were conducted using the National Synchrotron Light Source at Brookhaven National Laboratory. Samples of FEP/VDA were exposed with the FEP surface facing the synchrotron beam. Doses and fluences were compared with those estimated for the 20-yr Hubble Space Telescope mission.

  19. Use of ultraviolet radiation for inactivation of bacteria and coliphages in pretreated wastewater

    International Nuclear Information System (INIS)

    Dizer, H.; Bartocha, W.; Bartel, H.; Seidel, K.; Lopez-Pila, J.M.; Grohmann, A.

    1993-01-01

    The inactivation of bacteria and coliphages by u.v. radiation was tested in a full-scale pilot plant with a flow rate of 180 m 3 /h. The investigated water contained about 70% secondary effluent from sewage treatment plants and 30% surface water. The minimal rated radiation density was 13.3 mW/cm 2 (60% of u.v. transmission in water), and the radiation exposure lasted for 3.54 s resulting in a u.v. radiation dose of 47 mWs/cm 2 . This type of u.v. radiation chamber decreased the concentration of total coliform organisms, E. coli, fecal streptococci, Salmonella sp. and coliphages in the influent by 1–2 logs. Strains of bacteria, Streptococcus faecalis and Salmonella enteritidis, seeded artificially into the influent showed a reduction of about 2–4 logs after u.v. radiation. The coliphage f2 was more resistant than the tested bacteria and reduced by less than 2 logs through u.v. radiation. The inactivating effect of u.v. radiation was counteracted by the binding of the coliphage f2 to suspended turbid particles. It can be recommended to use u.v. treatment of effluents of wastewater plants after a flocculation and filtration step to improve the efficiency of the u.v. radiation. (author)

  20. THE ANTIGENIC POTENCY OF EPIDEMIC INFLUENZA VIRUS FOLLOWING INACTIVATION BY ULTRAVIOLET RADIATION

    Science.gov (United States)

    Salk, Jonas E.; Lavin, G. I.; Francis, Thomas

    1940-01-01

    A study of the antigenic potency of influenza virus inactivated by ultraviolet radiation has been made. Virus so inactivated is still capable of functioning as an immunizing agent when given to mice by the intraperitoneal route. In high concentrations inactivated virus appears to be nearly as effective as active virus but when quantitative comparisons of the immunity induced by different dilutions are made, it is seen that a hundredfold loss in immunizing capacity occurs during inactivation. Virus in suspensions prepared from the lungs of infected mice is inactivated more rapidly than virus in tissue culture medium. A standard for the comparison of vaccines of epidemic influenza virus is proposed. PMID:19871057

  1. Solar ultraviolet radiation in Syria measurements and relationship with skin cancer incidence

    International Nuclear Information System (INIS)

    Othman, I; Baydon, S.A.; Dawood, S.

    1994-11-01

    Seasonal variations of solar UVB (285-320) and UVA (320-400) were measured in three sites in Syria (33-37 N sup O) for two years: 1992-1993. UVB measurements were performed using polysulphone films and Robertson-Berger meter, while UVA measurements were done by NVA intensity meter. Two sets of measurements were carried out : - Maximal daily doses three times a week (every other day) - Diurnal variations from sun-rise to sun-set every two hours twice a month (every fortnight). The biological consequences of ultraviolet radiation withreference to some epidemiological data of skin cancer incidence in Syria since 1980 were discussed .(author). 36 refs., 21 figs., 11 tabs

  2. Excision repair in ataxia telangiectasia, Fanconi's anemia, Cockayne syndrome, and Bloom's syndrome after treatment with ultraviolet radiation and N-acetoxy-2-acetylaminofluorene

    International Nuclear Information System (INIS)

    Ahmed, F.E.; Setlow, R.B.

    1978-01-01

    Excision repair of damage due to ultraviolet radiation, N-acetoxy-2-acetylaminofluorene and a combination of both agents was studied in normal human fibroblasts and various cells from cancer prone patients (ataxia telangiectasia, Fanconi's anemia, Cockayne syndrome and Bloom's syndrome). Three methods giving similar results were used: unscheduled DNA synthesis by radioautography, photolysis of bromodeoxyuridine incorporated into parental DNA during repair, and loss of sites sensitive to an ultraviolet endonuclease. All cell lines were proficient in repair of ultraviolet and acetoxy acetylaminofluorene damage and at saturation doses of both agents repair was additive. We interpret these data as indicating that the rate limiting step in excision repair of ultraviolet and acetoxy acetylaminofluorene is different and that there are different enzyme(s) working on incision of both types of damages. (Auth.)

  3. Cytogenetic, cellular, and developmental responses in antarctic sea urchins (Sterechinus neumayeri) following laboratory ultraviolet-B and ambient solar radiation exposures

    International Nuclear Information System (INIS)

    Anderson, S.; Hoffman, J.; Wild, G.; Bosch, I.; Karentz, D.

    1993-01-01

    Increasing ultraviolet-B radiation as a consequence of springtime ozone depletion, could harm antarctic ecosystems. This study uses several techniques for studying genotoxic effects to evaluate UV-B effects in sea urchins from Antarctica. 6 refs., 2 figs

  4. Study of hemoglobin response to mid-ultraviolet (UVB) radiation using micro-Raman spectroscopy

    Science.gov (United States)

    Huang, Y. Y.; Li, N.; Zhou, S. N.; Huang, Z. T.; Zhuang, Z. F.

    2017-09-01

    Confocal micro-Raman spectroscopy is employed to monitor the damage to haemoglobin from mid-ultraviolet (UVB) radiation. We obtained the Raman spectra of an erythrocyte, which indicated that a peroxidation reaction occurs after UVB radiation. Further, the surface enhanced Raman scattering (SERS) spectra of isolated haemoglobin show that the intensities of the 1375 and 1399 cm-1 bands, which are markers of haem aggregation, obviously increase with prolonged UVB irradiation. This increase reveals that haem aggregation occurs in the peroxidation of erythrocytes. The UV-Vis spectra of isolated haemoglobin indicate that the Soret band, which is indicative of excitonic interactions in the aggregated haems, has a redshift ( 12 nm) after 30 min of UVB irradiation of erythrocytes. It can be deduced that an excitonic interaction occurs in the aggregated haems, which is caused by haemoglobin denaturation following UVB irradiation. In addition, the changes of the Raman marker bands during aggregation primarily originate from excitonic interactions. Throughout the process, a higher UVB radiation dose causes greater damage to haemoglobin.

  5. Ultraviolet radiation exposure from UV-transilluminators.

    Science.gov (United States)

    Akbar-Khanzadeh, Farhang; Jahangir-Blourchian, Mahdi

    2005-10-01

    UV-transilluminators use ultraviolet radiation (UVR) to visualize proteins, DNA, RNA, and their precursors in a gel electrophoresis procedure. This study was initiated to evaluate workers' exposure to UVR during their use of UV-transilluminators. The levels of irradiance of UV-A, UV-B, and UV-C were determined for 29 UV-transilluminators at arbitrary measuring locations of 6, 25, 62, and 125 cm from the center of the UV-transilluminator's filter surface in the direction of the operator's head. The operators (faculty, research staff, and graduate students) worked within 62 cm of the transilluminators, with most subjects commonly working at time ranged from 1 to 60 min. Actinic hazard (effective irradiance level of UVR) was also determined for three representative UV-transilluminators at arbitrary measuring locations of 2.5, 5, 10, 15, 20, 30, 40, and 50 cm from these sets' filter surface in the direction of the operator's head. The allowable exposure time for these instruments was less than 20 sec within 15 cm, less than 35 sec within 25 cm, and less than 2 min within 50 cm from the UV-transilluminators' filter surface. The results of this study suggest that the use of UV-transilluminators exposes operators to levels of UVR in excess of exposure guidelines. It is recommended that special safety training be provided for the affected employees and that exposure should be controlled by one or the combination of automation, substitution, isolation, posted warning signs, shielding, and/or personal protective equipment.

  6. 21 CFR 880.6500 - Medical ultraviolet air purifier.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical ultraviolet air purifier. 880.6500 Section 880.6500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... to ultraviolet radiation. (b) Classification. Class II (performance standards). ...

  7. Color stability of sealed composite resin restorative materials after ultraviolet artificial aging and immersion in staining solutions.

    Science.gov (United States)

    Catelan, Anderson; Briso, André Luiz Fraga; Sundfeld, Renato Hermann; Goiato, Marcelo Coelho; dos Santos, Paulo Henrique

    2011-04-01

    The color alteration of resin-based materials is one of the most common reasons to replace esthetic dental restorations. This study assessed the influence of surface sealant (Biscover) on the color stability of nanofilled (Supreme XT) and microhybrid (Vit-l-escence and Opallis) composite resins after artificial aging. One hundred disc-shaped (6 × 1.5 mm) specimens were made for each composite resin. After 24 hours, all specimens were polished and sealant was applied to 50 specimens of each material. Baseline color was measured according to the CIE L*a*b* system using a reflection spectrophotometer. Ten specimens of each group were aged for 252 h in an ultraviolet (UV)-accelerated aging chamber or immersed for 4 weeks in cola soft drink, orange juice, red wine staining solutions or distilled water as control. Color difference (ΔE) after aging was calculated based on the color coordinates before (baseline) and after aging/staining treatment. Data were analyzed with 2-way ANOVA and Fisher's test (α=.05). The results showed significant changes in color after artificial aging in all the groups (Paging, and the cola soft drink. The lowest values of ΔE were found for specimens stored in distilled water. All composite resins showed some color alteration after the aging methods. The surface sealant did not alter the color stability of the tested materials. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  8. ULTRAVIOLET TECHNOLOGY FOR FOOD PRESERVATION

    OpenAIRE

    Guedes, AMM; Novello, D; Mendes, GMD; Cristianini, M

    2009-01-01

    ULTRAVIOLET TECHNOLOGY FOR FOOD PRESERVATION This literature review article had as objective to gather information about ultraviolet (UV) technology utilization on the food industry, its effects and potential application. Aspects as the origin, concept and applications of the technology on the equipment industry and running mechanisms were approached. The application of UV radiation on food decontamination is still little used due its low penetration, but it is known that it can be easily app...

  9. Phototherapy appliances, their ultraviolet radiation and quality assurance of phototherapy

    International Nuclear Information System (INIS)

    Huurto, L.; Leszczynski, K.; Visuri, R.; Ylianttila, L.; Jokela, K.

    1998-01-01

    Artificial UV radiation (UVR) is used in the treatment of psoriasis and other skin diseases. Long term phototherapy is associated to increased risk of squamous cell carcinoma. This report gives a short review of biological effects of UVR and technical aspects of phototherapy units. The phototherapy units used in Finnish Central hospitals are described and the measured UVR dose rates of these units are presented. In addition, the UVR meters used in hospitals are described and the calibration factors are given for UVR dose rate measurements: Finally, recommendations are given for the quality assurance of photo-therapy units as well as for assessing UVR doses of patients. (orig.)

  10. Potential health effects of climatic change: Effects of increased ultraviolet radiation on man

    International Nuclear Information System (INIS)

    Urbach, F.

    1991-01-01

    There is scientific evidence that stratospheric ozone concentration has declined over the Northern Hemisphere in the past 20 years, and projections based on various assumption s about future release of chlorofluorocarbon gases and other contaminants suggest that this decline will continue into the next century. The effects on human health secondary to increase in biologically effective ultraviolet radiation are expected to consist of increases in nonmelanoma skin cancer and malignant melanoma of the skin, possible alteration of immune response, and development of lens cataracts. The recent and projected increases in skin cancer and changes in human immune responses are discussed. 19 refs

  11. Stellar extreme ultraviolet astronomy

    International Nuclear Information System (INIS)

    Cash, W.C. Jr.

    1978-01-01

    The design, calibration, and launch of a rocket-borne imaging telescope for extreme ultraviolet astronomy are described. The telescope, which employed diamond-turned grazing incidence optics and a ranicon detector, was launched November 19, 1976, from the White Sands Missile Range. The telescope performed well and returned data on several potential stellar sources of extreme ultraviolet radiation. Upper limits ten to twenty times more sensitive than previously available were obtained for the extreme ultraviolet flux from the white dwarf Sirius B. These limits fall a factor of seven below the flux predicted for the star and demonstrate that the temperature of Sirius B is not 32,000 K as previously measured, but is below 30,000 K. The new upper limits also rule out the photosphere of the white dwarf as the source of the recently reported soft x-rays from Sirius. Two other white dwarf stars, Feige 24 and G191-B2B, were observed. Upper limits on the flux at 300 A were interpreted as lower limits on the interstellar hydrogen column densities to these stars. The lower limits indicate interstellar hydrogen densitites of greater than .02 cm -3 . Four nearby stars (Sirius, Procyon, Capella, and Mirzam) were observed in a search for intense low temperature coronae or extended chromospheres. No extreme ultraviolet radiation from these stars was detected, and upper limits to their coronal emisson measures are derived

  12. Solar Radiation Measurement Using Raspberry Pi and Its Modelling Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Priya Selvanathan Shanmuga

    2016-01-01

    Full Text Available The advent of solar energy as the best alternative to traditional energy sources has led to an extensive study on the measurement and prediction of solar radiation. Devices such as pyranometer, pyrrheliometer, global UV radiometer are used for the measurement of solar radiation. The solar radiation measuring instruments available at Innovation Center, MIT Manipal were integrated with a Raspberry Pi to allow remote access to the data through the university Local Area Network. The connections of the data loggers and the Raspberry Pi were enclosed in a plastic box to prevent damage from the rainfall and humidity in Manipal. The solar radiation data was used to validate an Artificial Neural Network model which was developed using various meterological data from 2011-2015.

  13. Spectral filter for splitting a beam with electromagnetic radiation having wavelengths in the extreme ultraviolet (EUV) or soft X-Ray (Soft X) and the infrared (IR) wavelength range

    NARCIS (Netherlands)

    van Goor, F.A.; Bijkerk, Frederik; van den Boogaard, Toine; van den Boogaard, A.J.R.; van der Meer, R.

    2012-01-01

    Spectral filter for splitting the primary radiation from a generated beam with primary electromagnetic radiation having a wavelength in the extreme ultraviolet (EUV radiation) or soft X-ray (soft X) wavelength range and parasitic radiation having a wavelength in the infrared wavelength range (IR

  14. Green Synthesis of Ultraviolet Absorber 2-Ethylhexyl Salicylate: Experimental Design and Artificial Neural Network Modeling

    Directory of Open Access Journals (Sweden)

    Shang-Ming Huang

    2017-11-01

    Full Text Available 2-Ethylhexyl salicylate, an ultraviolet filter, is widely used to protect skin against sunlight-induced harmful effects in the cosmetic industry. In this study, the green synthesis of 2-ethylhexyl salicylate using immobilized lipase through a solvent-free and reduced pressure evaporation system was investigated. A Box–Behnken design was employed to develop an artificial neural network (ANN model. The parameters for an optimal architecture of an ANN were set out: a quick propagation algorithm, a hyperbolic tangent transfer function, 10,000 iterations, and six nodes within the hidden layer. The best-fitting performance of the ANN was determined by the coefficient of determination and the root-mean-square error between the correlation of predicted and experimental data, indicating that the ANN displayed excellent data-fitting properties. Finally, the experimental conditions of synthesis were well established with the optimal parameters to obtain a high conversion of 2-ethylhexyl salicylate. In conclusion, this study efficiently replaces the traditional solvents with a green process for the synthesis of 2-ethylhexyl salicylate to avoid environmental contamination, and this process is well-modeled by a methodological ANN for optimization, which might be a benefit for industrial production.

  15. Conversion of far ultraviolet to visible radiation: absolute measurements of the conversion efficiency of tetraphenyl butadiene

    Science.gov (United States)

    Vest, Robert E.; Coplan, Michael A.; Clark, Charles W.

    Far ultraviolet (FUV) scintillation of noble gases is used in dark matter and neutrino research and in neutron detection. Upon collisional excitation, noble gas atoms recombine into excimer molecules that decay by FUV emission. Direct detection of FUV is difficult. Another approach is to convert it to visible light using a wavelength-shifting medium. One such medium, tetraphenyl butadiene (TPB) can be vapor-deposited on substrates. Thus the quality of thin TPB films can be tightly controlled. We have measured the absolute efficiency of FUV-to-visible conversion by 1 μm-thick TPB films vs. FUV wavelengths between 130 and 300 nm, with 1 nm resolution. The energy efficiency of FUV to visible conversion varies between 1% and 5%. We make comparisons with other recent results. Work performed at the NIST SURF III Synchrotron Ultraviolet Radiation Facility,.

  16. Vacuum-ultraviolet circular dichroism spectrophotometer using synchrotron radiation

    International Nuclear Information System (INIS)

    Matsuo, K.; Fukuyama, T.; Yonehara, R.; Namatame, H.; Taniguchi, M.; Gekko, K.

    2005-01-01

    We have constructed a vacuum-ultraviolet circular dichroism (VUVCD) spectrophotometer using a synchrotron radiation and an assembled-type MgF 2 cell endurable under a high vacuum, to measure the CD spectra of biomaterials in aqueous solutions from 310 to 140 nm. To avoid the absorption of light by air and water vapor, all optical devices of the spectrophotometer were set up under a high vacuum (10 -4 Pa). A path length of the optical cell can be adjusted by various Teflon spacers in the range from 1.3 to 50 μm and its temperature can be controlled to an accuracy of ±1 deg. C over the range from -30 to 70 deg. C by a temperature-control unit using a Peltier thermoelectric element. The performance of the spectrophotometer and the optical cell constructed was tested by measuring the CD spectra of ammonium d-camphor-10-sulfonate, D- and L-isomers of amino acids, and myoglobin in aqueous solutions. The spectra obtained demonstrate that the optical system and the sample cell constructed operate normally under a high vacuum and provide useful information on the structure of biomolecules based on the higher energy chromophores

  17. Role of Ultraviolet Radiation in Papillomavirus-Induced Disease.

    Directory of Open Access Journals (Sweden)

    Aayushi Uberoi

    2016-05-01

    Full Text Available Human papillomaviruses are causally associated with 5% of human cancers. The recent discovery of a papillomavirus (MmuPV1 that infects laboratory mice provides unique opportunities to study the life cycle and pathogenesis of papillomaviruses in the context of a genetically manipulatable host organism. To date, MmuPV1-induced disease has been found largely to be restricted to severely immunodeficient strains of mice. In this study, we report that ultraviolet radiation (UVR, specifically UVB spectra, causes wild-type strains of mice to become highly susceptible to MmuPV1-induced disease. MmuPV1-infected mice treated with UVB develop warts that progress to squamous cell carcinoma. Our studies further indicate that UVB induces systemic immunosuppression in mice that correlates with susceptibility to MmuPV1-associated disease. These findings provide new insight into how MmuPV1 can be used to study the life cycle of papillomaviruses and their role in carcinogenesis, the role of host immunity in controlling papillomavirus-associated pathogenesis, and a basis for understanding in part the role of UVR in promoting HPV infection in humans.

  18. Solar ultraviolet radiation response of EBT2 Gafchromic, radiochromic film

    International Nuclear Information System (INIS)

    Butson, Ethan T; Yu, Peter K N; Butson, Martin J

    2013-01-01

    Measurement of solar ultraviolet (UV) radiation is an important aspect of dosimetry for the improved knowledge of UV exposure and its associated health related issues. EBT2 Gafchromic film has been designed by its manufacturers as an improved tool for ionizing radiation dosimetry. The film is stated as exhibiting a significant reduction in UV response. However, results have shown that when exposed to UV from the ‘bottom side’ i.e. from the thick laminate side, the film exhibits a sensitivity to solar UV radiation which is both measurable and accurate for UV dosimetry. Films were irradiated in this position to known solar UV exposures and results are quantified showing a reproducibility of measurement to within ±7% (1 SD) when compared to calibrated UV meters. With an exposure of 20 J cm −2 broad spectrum solar UV, the films net OD change was found to be 0.248 OD ± 0.021 OD when analysing the results using the red channel region of an Epson V700 desktop scanner. This was compared to 0.0294 OD ± 0.0053 OD change with exposure to the same UV exposure from the top side. This means that solar UV dosimetry can be performed using EBT2 Gafchromic film utilizing the underside of the film for dosimetry. The main advantages of this film type for measurement of UV exposure is the visible colour change and thus easy analysis using a desktop scanner as well as its uniformity in response and its robust physical strength for use in outside exposure situations. (note)

  19. Sunscreen protection against ultraviolet radiation-induced pyrimidine dimers in mouse epidermal DNA

    International Nuclear Information System (INIS)

    Ley, R.D.

    1997-01-01

    Solar ultraviolet radiation (UVR) induces a number of pathologic conditions of mammalian skin including erythema, oedema, hyperplasia, sunburn cell formation and skin cancer. Consequently, UVR-induced DNA damage has been implicated as one of the photochemical events that results in the formation of these pathological changes. The ability of sunscreens to protect against UVR-induced DNA damage has not been well characterized especially with UVA (320-400 nm) wavelengths and UVA absorbers. In this paper we present results of a study aimed at determining the efficacy of two sunscreens at preventing the induction of pyrmidine dimers in basal cell DNA of mice exposed to solar-simulated UVR (SSUV) wavelengths (290-400 nm) or to UVA (320-400 nm). (author)

  20. Sunscreen protection against ultraviolet radiation-induced pyrimidine dimers in mouse epidermal DNA

    Energy Technology Data Exchange (ETDEWEB)

    Ley, R.D. [The Lovelace Institutes, Albuqeurque, NM (United States). Photomdecine Program; Fourtanier, A. [L`Oreal, Advanced Research, Clichy (France)

    1997-06-01

    Solar ultraviolet radiation (UVR) induces a number of pathologic conditions of mammalian skin including erythema, oedema, hyperplasia, sunburn cell formation and skin cancer. Consequently, UVR-induced DNA damage has been implicated as one of the photochemical events that results in the formation of these pathological changes. The ability of sunscreens to protect against UVR-induced DNA damage has not been well characterized especially with UVA (320-400 nm) wavelengths and UVA absorbers. In this paper we present results of a study aimed at determining the efficacy of two sunscreens at preventing the induction of pyrmidine dimers in basal cell DNA of mice exposed to solar-simulated UVR (SSUV) wavelengths (290-400 nm) or to UVA (320-400 nm). (author).

  1. Utilization of ultraviolet radiation in effluent disinfestation of domestic waste treatment systems

    International Nuclear Information System (INIS)

    Camacho, P.R.R.; Andrade e Silva, L.G. de

    1995-01-01

    Ultraviolet radiation disinfection of Upflow Anaerobic Sludge Biodigestor (UASB) and UASB with aerated lagoon pos-treatment effluents is possible to be reached utilizing a single low pressure mercury lamp arc (15 W nominal power) in a shell tube flow through reactor (1.2 L useful volume). Fecal coliforms, total coliforms and colifages were used as microbiological parameters. For fecal coliforms, about 3 logarithmic units (log. un.) was removed from UASB with aerated lagoon pos-treatment effluent and 4 log. un. from UASB effluent with 7 and 30 seconds of hydraulic retention time, respectively. Good empirical correlations were obtained between microbiological parameters and hydraulic retention times. (author). 4 refs, 1 fig, 3 tabs

  2. Plasma radiation dynamics with the upgraded Absolute Extreme Ultraviolet tomographical system in the Tokamak à Configuration Variable

    Energy Technology Data Exchange (ETDEWEB)

    Tal, B.; Nagy, D.; Veres, G. [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Association EURATOM, P. O. Box 49, H-1525 Budapest (Hungary); Labit, B.; Chavan, R.; Duval, B. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association EURATOM-Confédération Suisse, EPFL SB CRPP, Station 13, CH-1015 Lausanne (Switzerland)

    2013-12-15

    We introduce an upgraded version of a tomographical system which is built up from Absolute Extreme Ultraviolet-type (AXUV) detectors and has been installed on the Tokamak à Configuration Variable (TCV). The system is suitable for the investigation of fast radiative processes usually observed in magnetically confined high-temperature plasmas. The upgrade consists in the detector protection by movable shutters, some modifications to correct original design errors and the improvement in the data evaluation techniques. The short-term sensitivity degradation of the detectors, which is caused by the plasma radiation itself, has been monitored and found to be severe. The results provided by the system are consistent with the measurements obtained with the usual plasma radiation diagnostics installed on TCV. Additionally, the coupling between core plasma radiation and plasma-wall interaction is revealed. This was impossible with other available diagnostics on TCV.

  3. 21 CFR 1040.20 - Sunlamp products and ultraviolet lamps intended for use in sunlamp products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sunlamp products and ultraviolet lamps intended... intended to be exposed to ultraviolet radiation from the product, as recommended by the manufacturer. (2... irradiation of any part of the living human body, by ultraviolet radiation with wavelengths in air between 200...

  4. Pollen and spores as a passive monitor of ultraviolet radiation

    Directory of Open Access Journals (Sweden)

    Wesley Toby Fraser

    2014-04-01

    Full Text Available Sporopollenin is the primary component of the outer walls of pollen and spores. The chemical composition of sporopollenin is responsive to levels of ultraviolet (UV radiation exposure, via a concomitant change in the concentration of phenolic compounds. This relationship offers the possibility of using fossil pollen and spore chemistry as a novel proxy for past UV flux. Phenolic compounds in sporopollenin can be quantified using Fourier Transform infrared spectroscopy. The high potential for preservation of pollen and spores in the geologic record, and the conservative nature of sporopollenin chemistry across the land plant phylogeny, means that this new proxy has the potential to reconstruct UV flux over much longer timescales than has previously been possible. This new tool has important implications for understanding the relationship between UV flux, solar insolation and climate in the past, as well as providing a possible means of assessing paleoaltitude, and ozone thickness.

  5. Topical W-7 inhibits ultraviolet radiation-induced melanogenesis in Skh:HR2 pigmented hairless mice

    International Nuclear Information System (INIS)

    Dowdy, J.C.; Anthony, F.A.; Costlow, M.E.

    1995-01-01

    We studied the effect of N-(6-aminohexyl)-5-chloro-1-napthalenesulfonamide (W-7) on ultraviolet radiation (UVR)-induced melanogenesis (tanning) in Skh:HR2 pigmented hairless mice. Topically pretreated mice were exposed to subminimal edematogenic as well as edematogenic UVR doses to establish whether W-7-UVR-induced edema prophylaxis allows increased melanogenesis while preventing edema. Ultraviolet light-irradiated vehicle control animals developed visible trans; however, both W-7-treated groups failed to tan. Topical W-7 before UVR exposure inhibited UVR induction of dopa oxidase activity in melanocytes by 49% (P=0.029) and inhibited UVR-induced deposition of melanin in the epidermis by 88% (P=0.006). Topical W-7 blocked 23% of the UVR but this blockage could not account for the inhibition of dopa oxidase and melanization. We conclude that, in addition to preventing edema, W-7 inhibits UVR-induced melanogenesis, possibly by affecting Ca 2+ -calmodulin and/or protein kinase C-dependent processes. (au) 30 refs

  6. Topical W-7 inhibits ultraviolet radiation-induced melanogenesis in Skh:HR2 pigmented hairless mice

    Energy Technology Data Exchange (ETDEWEB)

    Dowdy, J.C. [Univ. of Memphis, Div. of Molecular Sciences and Microbiology, Memphis, Tennessee (United States); Anthony, F.A.; Costlow, M.E. [Schering-Plough HealthCare Products, Inc., Advanced Product Research, Memphis, Tennessee (United States)

    1995-08-01

    We studied the effect of N-(6-aminohexyl)-5-chloro-1-napthalenesulfonamide (W-7) on ultraviolet radiation (UVR)-induced melanogenesis (tanning) in Skh:HR2 pigmented hairless mice. Topically pretreated mice were exposed to subminimal edematogenic as well as edematogenic UVR doses to establish whether W-7-UVR-induced edema prophylaxis allows increased melanogenesis while preventing edema. Ultraviolet light-irradiated vehicle control animals developed visible trans; however, both W-7-treated groups failed to tan. Topical W-7 before UVR exposure inhibited UVR induction of dopa oxidase activity in melanocytes by 49% (P=0.029) and inhibited UVR-induced deposition of melanin in the epidermis by 88% (P=0.006). Topical W-7 blocked 23% of the UVR but this blockage could not account for the inhibition of dopa oxidase and melanization. We conclude that, in addition to preventing edema, W-7 inhibits UVR-induced melanogenesis, possibly by affecting Ca{sup 2+}-calmodulin and/or protein kinase C-dependent processes. (au) 30 refs.

  7. 21 CFR 872.6070 - Ultraviolet activator for polymerization.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet activator for polymerization. 872.6070 Section 872.6070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ultraviolet radiation intended to polymerize (set) resinous dental pit and fissure sealants or restorative...

  8. Inactivation of oocysts of Cryptosporidium parvum by ultraviolet irradiation

    International Nuclear Information System (INIS)

    Campbell, A.T.; Robertson, L.J.; Snowball, M.R.; Smith, H.V.

    1995-01-01

    Inactivation of oocysts of Cryptosporidium parvum in clean water using a novel design of an ultraviolet disinfection system was assessed by a vital dye assay and by in vitro excystation. The disinfection unit system is designed to expose the oocysts to ultraviolet radiation on two filters, providing a maximum total exposure to ultraviolet radiation of 8748 mW s cm −2 . Results revealed a reduction in oocyst viability of over two logs, indicating that this treatment has exciting potential as an additional treatment for water already treated by conventional methods. However, these data are only preliminary results using one isolate of oocysts and further trials must be conducted before this system could be recommended for use

  9. The caretakers of the genome. Repair of DNA lesions induced by ultraviolet-light and ionizing radiation

    International Nuclear Information System (INIS)

    Boiteux, S.; Radicella, J.P.

    2000-01-01

    The DNA contained in the nucleus of each of our cells daily suffers of thousand damages caused by solar ultraviolet radiations or ionizing radiations, with a natural or not origin, agents able to modify the genetic information. This information stays stable. True caretakers of the genome repair the DNA, provided that the cell is not over-taken by the level of the attack. Alterations of the repair mechanism are at the origin of extremely severe syndromes. The failure of one of these caretakers of the genome, the O.G.G.1 gene, seems implicated in the cancer development. It can be a lead to discover a predisposition to radioinduced or caused by other toxic agents cancers. (N.C.)

  10. Ultraviolet safety assessments of insect light traps.

    Science.gov (United States)

    Sliney, David H; Gilbert, David W; Lyon, Terry

    2016-01-01

    Near-ultraviolet (UV-A: 315-400 nm), "black-light," electric lamps were invented in 1935 and ultraviolet insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous ultraviolet emissions. A variety of UV "Black-light" ILTs were measured at a range of distances to assess potential exposures. Realistic time-weighted human exposures are shown to be well below current guidelines for human exposure to ultraviolet radiation. These UV-A exposures would be far less than the typical UV-A exposure in the outdoor environment. Proposals are made for realistic ultraviolet safety standards for ILT products.

  11. Long-range effects of direct-hit ultraviolet and particle radiation in oncogene activation

    International Nuclear Information System (INIS)

    Ladik, J.J.

    1990-01-01

    A simple statistical analysis shows that the oncogene-activation effect of chemical carcinogens cannot be explained if one takes into account only short-range effects. As one of the most probable solid state physical long-range effects, the generation at the site of carcinogen binding of travelling solitary waves, which can interfere with DNA-blocking protein interactions, is discussed. It has been shown that the direct hit carcinogenic effects on DNA by ultraviolet--or particle radiation can also be explained by the generation of solitary waves (in the latter case the first step is a collective plasma oscillation which decays to individual local excitations and ionizations)

  12. ROLE OF THE EGG JELLY COAT IN PROTECTING HYLA REGILLA AND BUFO CANORUS EMBRYOS FROM ULTRAVIOLET B RADIATION DURING DEVELOPMENT

    Science.gov (United States)

    Previous studies have suggested that Ultraviolet B (UVB) radiation may play a role in amphibian population declines. Some of these studies also indicate that egg hatching success is unaltered in some species of anurans as a result of UVB exposure. It has been proposed that the eg...

  13. Modification of the cellular heat sensitivity of cucumber by growth under supplemental ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Caldwell, C.R.

    1994-01-01

    The effect of ultraviolet B (UV-B) radiation on the thermal sensitivity of cucumber (Cucumis sativus L.) was studied using UV-B-sensitive cv Poinsett 76 and UV-B-resistant cv Ashley grown under control and elevated (300 mW m -2 ) UV-B radiation levels. Using both cotyledon and leaf discs, the ability of the tissue to reduce triphenyl tetrazolium chloride (TTC) was determined after treatment at 50 degrees C for various times. Semilogarithmic plots of TTC reduction as a function of time at 50 degrees were curvilinear. They were monophasic for the control cucumber and biphasic for cucumber grown in the presence of elevated UV-B. Treatment of cucumber plants at 37 degrees C for 24 h or of tissue discs at acute UV-B levels for 1 h further modified their response to elevated temperature. These results suggest that growth of cucumber under enhanced UV-B radiation levels increased its ability to withstand elevated temperatures. 19 refs., 2 figs., 2 tabs

  14. Grazing rates of Calanus finmarchicus on Thalassiosira weissflogii cultured under different levels of ultraviolet radiation.

    Directory of Open Access Journals (Sweden)

    David M Fields

    Full Text Available UVB alters photosynthetic rate, fatty acid profiles and morphological characteristics of phytoplankton. Copepods, important grazers of primary production, select algal cells based upon their size, morphological traits, nutritional status, and motility. We investigated the grazing rates of the copepod Calanus finmarchicus on the diatom Thalassiosira weissflogii cultured under 3 levels of ultraviolet radiation (UVR: photosynthetically active radiation (PAR only (4 kJ-m(-2/day, and PAR supplemented with UVR radiation at two intensities (24 kJ-m(-2/day and 48 kJ-m(-2/day. There was no significant difference in grazing rates between the PAR only treatment and the lower UVR treatment. However, grazing rates were significantly (∼66% higher for copepods feeding on cells treated with the higher level of UVR. These results suggest that a short-term increase in UVR exposure results in a significant increase in the grazing rate of copepods and, thereby, potentially alters the flow rate of organic matter through this component of the ecosystem.

  15. Doses of radiation from natural and artificial radioactive sources. [In German

    Energy Technology Data Exchange (ETDEWEB)

    Franzen, L F; Myszynski, G; Wiesenack, G

    1957-01-01

    Only since quite recently has man been subjected to irradiation which, as the result of medical and industrial development has been added to the radiation from natural sources. According to the investigations quoted artificial radiation accounts for 20 to 25 per cent of the total radiation level. Atomic test explosions have so far only made an insignificant contribution. The same can still be said of the industrial application of nuclear energy which is still in its infancy. It has been estimated that people living in Europe will over a period of 30 years be subjected to a total dose of radiation from 2500 to 4000 mr. Of this total dose received in 30 years about 750 to 850 mr will be contributed by medical and industrial appurtenances, the overwhelming share of 600 to 700 mr being the result of medical x-ray diagnosis. The atmospheric radioactivity has been estimated (incl. rainfall, etc.) at 20 to 30 mr over a period of 30 years and will therefore not represent any hazards as far as external, direct radiation is concerned. The possible absorption by and accumulation of radiation substances in the body must, however, be carefully studied and special consideration must be given to fission products with a long half-life.

  16. DNA repair synthesis in human skin exposed to ultraviolet radiation used in PUVA (psoralen and UV-A) therapy for psoriasis

    International Nuclear Information System (INIS)

    Bishop, S.C.

    1979-01-01

    The ultraviolet radiation used in psoralen and UV-A (PUVA) therapy stimulated DNA repair activity in normal human skin and in the uninvolved skin from psoriatic patients. The activity detected by autoradiography increased linearly with exposure time. No stimulation was observed when the UV-B component was removed from the incident radiation by filtration through glass. Therefore UV-B damage to DNA was found responsible for the activity detected following exposure to the unfiltered PUVA light source. (author)

  17. Decolorization of Methylene Blue by Ag/SrSnO3 Composites under Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    Patcharanan Junploy

    2014-01-01

    Full Text Available SrSn(OH6 precursors synthesized by a cyclic microwave radiation (CMR process were calcined at 900°C for 3 h to form rod-like SrSnO3. Further, the rod-like SrSnO3 and AgNO3 in ethylene glycol (EG were ultrasonically vibrated to form rod-like Ag/SrSnO3 composites, characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, electron microscopy (EM, Fourier transform infrared (FTIR spectroscopy, and UV-visible analysis. The photocatalyses of rod-like SrSnO3, 1 wt%, 5 wt%, and 10 wt% Ag/SrSnO3 composites were studied for degradation of methylene blue (MB, C16H18N3SCl dye under ultraviolet (UV radiation. In this research, the 5 wt% Ag/SrSnO3 composites showed the highest activity, enhanced by the electron-hole separation process. The photoactivity became lower by the excessive Ag nanoparticles due to the negative effect caused by reduction in the absorption of UV radiation.

  18. Angular distribution of ions and extreme ultraviolet emission in laser-produced tin droplet plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong; Duan, Lian; Lan, Hui [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Wang, Xinbing, E-mail: xbwang@hust.edu.cn; Chen, Ziqi; Zuo, Duluo [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu, Peixiang [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-05-21

    Angular-resolved ion time-of-flight spectra as well as extreme ultraviolet radiation in laser-produced tin droplet plasma are investigated experimentally and theoretically. Tin droplets with a diameter of 150 μm are irradiated by a pulsed Nd:YAG laser. The ion time-of-flight spectra measured from the plasma formed by laser irradiation of the tin droplets are interpreted in terms of a theoretical elliptical Druyvesteyn distribution to deduce ion density distributions including kinetic temperatures of the plasma. The opacity of the plasma for extreme ultraviolet radiation is calculated based on the deduced ion densities and temperatures, and the angular distribution of extreme ultraviolet radiation is expressed as a function of the opacity using the Beer–Lambert law. Our results show that the calculated angular distribution of extreme ultraviolet radiation is in satisfactory agreement with the experimental data.

  19. Angular distribution of ions and extreme ultraviolet emission in laser-produced tin droplet plasma

    International Nuclear Information System (INIS)

    Chen, Hong; Duan, Lian; Lan, Hui; Wang, Xinbing; Chen, Ziqi; Zuo, Duluo; Lu, Peixiang

    2015-01-01

    Angular-resolved ion time-of-flight spectra as well as extreme ultraviolet radiation in laser-produced tin droplet plasma are investigated experimentally and theoretically. Tin droplets with a diameter of 150 μm are irradiated by a pulsed Nd:YAG laser. The ion time-of-flight spectra measured from the plasma formed by laser irradiation of the tin droplets are interpreted in terms of a theoretical elliptical Druyvesteyn distribution to deduce ion density distributions including kinetic temperatures of the plasma. The opacity of the plasma for extreme ultraviolet radiation is calculated based on the deduced ion densities and temperatures, and the angular distribution of extreme ultraviolet radiation is expressed as a function of the opacity using the Beer–Lambert law. Our results show that the calculated angular distribution of extreme ultraviolet radiation is in satisfactory agreement with the experimental data

  20. Artificial neural network optimisation for monthly average daily global solar radiation prediction

    International Nuclear Information System (INIS)

    Alsina, Emanuel Federico; Bortolini, Marco; Gamberi, Mauro; Regattieri, Alberto

    2016-01-01

    Highlights: • Prediction of the monthly average daily global solar radiation over Italy. • Multi-location Artificial Neural Network (ANN) model: 45 locations considered. • Optimal ANN configuration with 7 input climatologic/geographical parameters. • Statistical indicators: MAPE, NRMSE, MPBE. - Abstract: The availability of reliable climatologic data is essential for multiple purposes in a wide set of anthropic activities and operative sectors. Frequently direct measures present spatial and temporal lacks so that predictive approaches become of interest. This paper focuses on the prediction of the Monthly Average Daily Global Solar Radiation (MADGSR) over Italy using Artificial Neural Networks (ANNs). Data from 45 locations compose the multi-location ANN training and testing sets. For each location, 13 input parameters are considered, including the geographical coordinates and the monthly values for the most frequently adopted climatologic parameters. A subset of 17 locations is used for ANN training, while the testing step is against data from the remaining 28 locations. Furthermore, the Automatic Relevance Determination method (ARD) is used to point out the most relevant input for the accurate MADGSR prediction. The ANN best configuration includes 7 parameters, only, i.e. Top of Atmosphere (TOA) radiation, day length, number of rainy days and average rainfall, latitude and altitude. The correlation performances, expressed through statistical indicators as the Mean Absolute Percentage Error (MAPE), range between 1.67% and 4.25%, depending on the number and type of the chosen input, representing a good solution compared to the current standards.

  1. Dose assessment on natural radiation, natural radionuclide, and artificial radionuclide released by Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Hosoda, Masahiro; Tokonami, Shinji; Furukawa, Masahide

    2012-01-01

    Various radionuclides are distributed in environmental materials such as soil, rock, and water. People are exposed every day to natural radiation. According to the UNSCEAR 2008 report, Sources of Ionizing Radiation, natural radiation sources are categorized as terrestrial gamma-rays, radon, cosmic rays and food. The effective dose from radon, thoron and its decay products is about 50% of all natural radiation exposure. Consciousness of the Japanese public toward radiation exposure has significantly increased since the start of the Fukushima Dai-ichi Nuclear Power Station accident. In this paper, the nationwide survey and dose estimation for terrestrial gamma-rays and radon are summarized. External dose from artificial radionuclides released by the Fukushima accident are also reported. (author)

  2. Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Hilbert, V.; Rödel, C.; Zastrau, U., E-mail: ulf.zastrau@uni-jena.de [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Brenner, G.; Düsterer, S.; Dziarzhytski, S.; Harmand, M.; Przystawik, A.; Redlin, H.; Toleikis, S. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Döppner, T.; Ma, T. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Fletcher, L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Förster, E. [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Glenzer, S. H.; Lee, H. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Hartley, N. J. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Kazak, L.; Komar, D.; Skruszewicz, S. [Institut für Physik, Universität Rostock, 18051 Rostock (Germany); and others

    2014-09-08

    A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5 nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

  3. Impact of ultraviolet-beta radiation on two species of forest dwarf shrubs: bilberry (Vaccinium myrtillus L.) and cowberry (Vaccinium vitis-idaea L.)

    International Nuclear Information System (INIS)

    Robakowski, P.

    1999-01-01

    The impact of UV-B radiation on chlorophyll content and chlorophyll fluoroscence of two dwarth shrub species was investigated. The plants originating from different latitudes were used. Three variants of ultraviolet-B radiation were applied: control = 0, lower dose = 11,32 and higher dose = 22,64 kJ/square m/day. Measurements of chlorophyll fluorescence and chlorophyll content were carried out. The response of dwarf shrubs to the increased UV-B radiation depended on UV-B dose, species traits and provenance

  4. The effect of single and repeated ultraviolet radiation on the anterior segment of the rabbit eye

    OpenAIRE

    Fris, Miroslav

    2008-01-01

    Over the last two decades, depletion of stratospheric ozone has increased the flux of ultraviolet radiation (UVR) at the surface of the earth and the cumulative effect of UVR has become an important aspect of UV-induced eye damage. Epidemiological studies generally assess the chronic, low dose UVR exposure conditions while the laboratory animal experiments usually examine the acute response to high dose exposures. Thus, the study conditions are dissimilar and we are not free to assume that th...

  5. Ultraviolet radiation induces changes in membrane metabolism of human keratinocytes in culture

    International Nuclear Information System (INIS)

    De Leo, V.A.; Horlick, H.; Hanson, D.; Eisinger, M.; Harber, L.C.

    1984-01-01

    Human keratinocytes in culture were prelabeled with [ 3 H]arachidonic acid (AA) and then exposed to ultraviolet B radiation. Irradiated cells released labeled AA metabolites into media in a dose-dependent manner when compared to sham-irradiated cells. The response began immediately and continued for 24 h. Extracts from media were examined by high-performance liquid chromatography for identification of specific AA metabolites. Irradiated cells were stimulated to produce prostaglandin-like material (PGE2 and PGF2 alpha). These findings support the concept that the cell membrane of keratinocytes participates directly or indirectly in initiating the sunburn response. It is also felt that the metabolites formed following injury to the membrane are an integral component in the mediation of that response

  6. Sensitization of ultraviolet radiation damage in bacteria and mammalian cells

    International Nuclear Information System (INIS)

    Fisher, G.J.; Watts, M.E.; Patel, K.B.; Adams, G.E.

    1978-01-01

    Bacteria (Serratia marcescens) and mammalian cells (Chinese hamsters V79-379A) were irradiated in monolayers with ultraviolet light at 254 nm or 365 nm in the presence or absence of radiosensitizing drugs. At 254 nm, killing is very efficient (Dsub(37) approximately equal 1 J m -2 exposure, or approximately equal 6 x 10 4 photons absorbed by DNA per bacterium), and sensitizers have no effect. At 365 nm, cells are not killed in buffer, but are inactivated in the presence of nifurpipone or misonidazole. Lethal exposures (approximately equal 5 x 10 3 J m -2 at 10 nM misonidazole) correspond to about 10 7 photons absorbed by sensitizer molecules per bacterium. Toxicity of stable photoproducts of the drugs is not involved, nor is oxygen required. Hence the transient species formed by photo-excitation of radiosensitizer molecules are capable of killing cells in the absence of other types of radiation damage. (author)

  7. Dosimetry of ultraviolet radiation with BaHfO_3 powders

    International Nuclear Information System (INIS)

    Barrera A, A. A.; Aguilar D, G. A.; Guzman M, J.; Rivera M, T.; Ceron R, V.

    2016-10-01

    Ceramic materials based on pure barium hafnate (BaHfO_3) have been obtained as a powder by the co-precipitation method. The powders obtained have a cubic structure that favors the thermoluminescent and optical properties, through which a better detection of the non-ionizing radiation is allowed. With these powders various tests were performed in the ultraviolet range at different exposure times. These thermoluminescent (Tl) studies were carried out using a Tl 3500 hand held reader which yielded a brightness curve that ranged from room temperature to the 350 degrees Celsius. This BaHfO_3 response exhibits a broad brightness curve with a single peak centered around 225 degrees Celsius. Finally, is reported that there are materials of barium hafnate (BaHfO_3) doped with some rare earths (Eu, Tb) which, instead of improving the performance of the powders, decrease it, so that the use of intrinsic barium hafnate is the most appropriate. (Author)

  8. Ocular effects of ultraviolet radiation from 295 to 365 nm

    International Nuclear Information System (INIS)

    Pitts, D.G.; Cullen, A.P.; Hacker, P.D.

    1977-01-01

    A 5,000 watt Xe--Hg source and a double monochromator were used to produce 6.6 nm full band-pass ultraviolet (UV) radiation. Pigmented rabbit eyes were exposed to the 6.6 nm band-pass UV radiant energy in 5 nm steps from 295 to 320 nm and at random intervals above 320 nm. Corneal and lenticular damage was assessed and classified with a biomicroscope. Corneal threshold radiant exposure (Hc) rose very rapidly from 0.022 Jcm -2 at 300 nm to 10.99 Jcm -2 at 335 nm. Radiant exposures exceeding 2 x Hc resulted in irreversible corneal damage. Lenticular damage was limited to wavebands above 295 nm. The action spectrum for the lens began at 295 nm and extended to about 315 nm. Permanent lenticular damage occurred at radiant exposure levels approximately twice the threshold for lenticular radiant exposure. The importance in establishing both corneal and lenticular damage criteria is emphasized

  9. Health impacts of ultraviolet radiation in urban ecosystems: a review

    Science.gov (United States)

    Heisler, Gordon M.

    2005-08-01

    This paper explores the literature on ultraviolet irradiance (UV) in urban ecosystems with respect to the likely effects on human health. The focus was the question of whether the health effects of UV radiation should be included in planning of landscape elements such as trees and shading structures. In examining the literature, special attention was given to seeking information on the question of whether it is important that shade be provided for elementary school play areas, and if so, how should it be accomplished? Before such practical questions could be dealt with, it became obvious that answers to several pertinent secondary questions had to be sought. Foremost of these was, what are the negative and positive health effects of UV exposure? Recent epidemiological findings of apparent benefits of sunlight because of vitamin-D photosynthesis and resulting anti-cancer effects make this highly relevant. Another basic question is that of trends in ozone depletion, which leads to interesting questions of long-term trends, short-term extremes, and urban influences on UV irradiance. A host of these and other pertinent questions, such as, "What is the relationship between climate of a location and dress," i.e., "How much exposure will people receive during time spent outdoors?" require much more study. Judging from current knowledge of typical spectra of solar radiation in tree shade and the difference between the action spectra for vitamin D synthesis and erythema in human skin, exposure to solar radiation in tree shade for a short period of time can be somewhat more beneficial for vitamin D synthesis and regulation than detrimental in producing sunburn.

  10. Estimating surface longwave radiative fluxes from satellites utilizing artificial neural networks

    Science.gov (United States)

    Nussbaumer, Eric A.; Pinker, Rachel T.

    2012-04-01

    A novel approach for calculating downwelling surface longwave (DSLW) radiation under all sky conditions is presented. The DSLW model (hereafter, DSLW/UMD v2) similarly to its predecessor, DSLW/UMD v1, is driven with a combination of Moderate Resolution Imaging Spectroradiometer (MODIS) level-3 cloud parameters and information from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim model. To compute the clear sky component of DSLW a two layer feed-forward artificial neural network with sigmoid hidden neurons and linear output neurons is implemented; it is trained with simulations derived from runs of the Rapid Radiative Transfer Model (RRTM). When computing the cloud contribution to DSLW, the cloud base temperature is estimated by using an independent artificial neural network approach of similar architecture as previously mentioned, and parameterizations. The cloud base temperature neural network is trained using spatially and temporally co-located MODIS and CloudSat Cloud Profiling Radar (CPR) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations. Daily average estimates of DSLW from 2003 to 2009 are compared against ground measurements from the Baseline Surface Radiation Network (BSRN) giving an overall correlation coefficient of 0.98, root mean square error (rmse) of 15.84 W m-2, and a bias of -0.39 W m-2. This is an improvement over an earlier version of the model (DSLW/UMD v1) which for the same time period has an overall correlation coefficient 0.97 rmse of 17.27 W m-2, and bias of 0.73 W m-2.

  11. Effects of exposure to ultraviolet light on the development of Rana pipiens, the northern leopard frog

    International Nuclear Information System (INIS)

    Williams, J.J.; Wofford, H.W.

    1996-01-01

    The increase in ultraviolet light intensity levels due to ozone depletion recently has been linked to the decline in amphibian population. In this experiment, eggs and larvae of Rana pipiens were subjected to differing amounts of ultraviolet radiation to determine the effects of ultraviolet light on the development of amphibian tadpoles. The total length, length of body without tail, and maximum width of each specimen was recorded for a month of the tadpoles' development, including several measurements after the ultraviolet exposures were concluded. It was found that ultraviolet exposure significantly reduced the size of the organisms in comparison with the control group in all three measured areas. Ultraviolet radiation altered the health and appearance of the exposed organisms and was lethal at large amounts. This experiment showed that ultraviolet radiation could cause many problems in developing amphibians. By slowing their development and physically weakening predation, thus contributing to a decline in overall population levels

  12. Differential responses of growth and photosynthesis in Cyamopsis tetragonoloba grown under ultraviolet-B and supplemental long-wavelength radiations

    International Nuclear Information System (INIS)

    Lingakumar, K.; Kulandaivelu, G.

    1998-01-01

    Cyamopsis tetragonoloba seedlings were subjected to continuous ultraviolet (UV)B radiation for 18 h and post-irradiated with 'white light' (WL) and UV-A enhanced fluorescent radiations. UV-B treatment alone reduced plant growth, pigment content, and photosynthetic activities. Supplementation of UV-A promoted the overall seedling growth and enhanced the synthesis of chlorophyll and carotenoids with a relatively high photosystem 1 activity. Post UV-B irradiation under WL failed to photoreactivate the LTV-B damage whereas a positive photoregulatory effect of UV-A was noticed in electron transport rates and low temperature fluorescence emission spectra

  13. Nanoscale freestanding gratings for ultraviolet blocking filters

    Energy Technology Data Exchange (ETDEWEB)

    van Beek, J.T.; Fleming, R.C.; Hindle, P.S.; Prentiss, J.D.; Schattenburg, M.L. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Ritzau, S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1998-11-01

    Ultraviolet (UV) blocking filters are needed for atomic flux imaging in environments where high levels of ultraviolet radiation are present. Freestanding gratings are a promising candidate for UV filtering. They have a high aspect ratio ({approximately}13), narrow ({approximately}40 nm) slots, and effectively block UV radiation. The grating fabrication process makes use of several etching, electroplating, and lithographic steps and includes an optional step to plug pinholes induced by particles during processing. Gratings were successfully manufactured and tested. Measured UV transmissions of {approximately}10{sup {minus}5} and particle transmissions of {approximately}10{percent} are in agreement with theoretical predictions. {copyright} {ital 1998 American Vacuum Society.}

  14. Formation of thymine containing dimers in skin exposed to ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, B E [Dundee Univ. (UK)

    1978-01-01

    Nuclear DNA appears to be the major molecular target for the inhibitory, mutagenic and lethal effects of ultraviolet radiation on cells in culture. Cyclobutyl dimers between adjacent pyrimidine bases, the major photochemical lesions for these effects in prokaryotes, also play a part in UVR effects on eukaryotes cells. Pyrimidine dimers have been isolated from in vivo UV-irradiated guinea pig and mouse skin. The wavelength dependence for dimer induction is similar to that for acute skin reactions but no direct causal relationship has been established. Sunlight UVR may induce dimers in skin DNA. Excision of dimers from mouse skin in vivo is deficient as it is for most rodent cells in culture; human cell excision is efficient and the difficulties in interpretation of UV-carcinogenesis results with mice in terms of human skin cancer are therefore increased.

  15. Short and long term variation in ultraviolet radiation and multiple sclerosis

    DEFF Research Database (Denmark)

    Menni, Cristina; Lowell, Walter E; Bentzen, Joan

    2012-01-01

    We examined the role of ultraviolet radiation (UVR) in persons diagnosed with multiple sclerosis (MS) in four different populations, Italians, Danish, White and African Americans. We tested whether variation in UVR as determined by seasons (short term variation) and solar cycles (long term...... to study the pattern of month of birth distribution in patients with MS comparing with general population data. T-tests were employed to study solar cycles association with lifespan. A surplus of births was observed in June for White Americans. A decrease of births in October and November, though...... not significant after multiple testing correction, was observed in the three populations. In White American with MS overall, males and females, we found that solar cycle is associated with lifespan. We found that season and solar cycles have some role in MS susceptibility and life duration. However...

  16. Effect of gamma and ultraviolet radiations in isolates of Metarhizium anisopliae (METSCH) Sorokin, 1883 and its utilization aiming Diatraea saccharalis (FABRICIUS, 1794) control

    International Nuclear Information System (INIS)

    Almeida, L.C. de.

    1983-06-01

    The effects of gamma radiation and ultraviolet in isolated of the fungus Metarhizium anisopliae (Metsch) Sorokin, and the utilization of this pathogen for the Diatrae saccharalis (Fabr.) control are studied. (L.M.J.) [pt

  17. A review of biological effects and potential risks associated with ultraviolet radiation as used in dentistry. Technical report

    International Nuclear Information System (INIS)

    Mills, L.F.; Lytle, C.D.; Andersen, F.A.; Hellman, K.B.; Bockstahler, L.E.

    1975-10-01

    Several dental procedures, recently developed and currently in use by the dental profession, involve the use of near or far ultraviolet (UV) radiation in the oral cavity. Recent studies on the biological effects of near and far UV radiation suggest potential risks to individuals from excessive UV exposure. In this paper the dental procedures are briefly described, the bases for UV safety standards are reviewed, effects of UV exposure to the skin and eyes and how these effects may relate to oral mucosa exposure are considered, potential modes of action by UV radiation on oral tissues as suggested by cell culture studies are summarized, and potential risks from UV exposure of individuals which might result from the dental procedures are discussed

  18. The Ultraviolet Index: a useful tool.

    Science.gov (United States)

    Kinney, J P; Long, C S

    2000-09-01

    The Ultraviolet Index was developed in the United States in 1994 following successful use of ultraviolet (UV) alerts in other countries. This daily National Weather Service prediction is a calculation which integrates five data elements to yield the amount of UV radiation impacting the surface (1m2) at solar noon in 58 of the largest US population centers. This simple numeric prediction is then categorized by the Environmental Protection Agency into five "exposure levels" with protective actions recommended for each level. This information is disseminated through the media. Daily reminders seem to affect awareness and behavior in Canada, but US surveys indicate the need for better understanding through educational graphics. Comparing the UV Index to a precipitation prediction has merit in that it links a familiar daily prediction with implied appropriate protective measures. Graphics link the ideas that "when it rains it pours and when it shines it radiates." Beginning in schools, camps, and dermatology meetings, using the rain/shine analogy, a wider exposure to the Ultraviolet Index is proposed.

  19. Induction of heat shock-like proteins in Vigna sinensis seedlings growing under ultraviolet-B (280-320 nm) enhanced radiation

    International Nuclear Information System (INIS)

    Nedunchezhian, N.; Annamalainathan, K.; Kulandaivelu, G.

    1992-01-01

    The effect of ultraviolet-B (UV-B) enhanced fluorescent radiation on protein profile and protein synthesis has been investigated in Vigna sinensis L. cv. Walp seedlings growing at various temperatures. In seedlings growing at 30°C, UV-B radiation decreased the level of several proteins as seen in Coomassie brilliant blue stained gel. However, fluorography of the same gel indicates induction of three sets of proteins in the range of 70. 53 and 16 k Da. Such induction under UV-B enhanced radiation resembled that found after heat shock treatments. In seedlings at 10 and 20°C, induction of such proteins varied both qualitatively and quantitatively. At 40°C. UV-B enhanced radiation caused a cumulative effect with temperature. Strong induction of specific proteins by UV-B radiation in seedlings growing under normal temperature indicates a possible protective role

  20. Rapid modulation of ultraviolet shielding in plants is influenced by solar ultraviolet radiation and linked to alterations in flavonoids.

    Science.gov (United States)

    Barnes, Paul W; Tobler, Mark A; Keefover-Ring, Ken; Flint, Stephan D; Barkley, Anne E; Ryel, Ronald J; Lindroth, Richard L

    2016-01-01

    The accumulation of ultraviolet (UV)-absorbing compounds (flavonoids and related phenylpropanoids) and the resultant decrease in epidermal UV transmittance (TUV ) are primary protective mechanisms employed by plants against potentially damaging solar UV radiation and are critical components of the overall acclimation response of plants to changing solar UV environments. Whether plants can adjust this UV sunscreen protection in response to rapid changes in UV, as occurs on a diurnal basis, is largely unexplored. Here, we use a combination of approaches to demonstrate that plants can modulate their UV-screening properties within minutes to hours, and these changes are driven, in part, by UV radiation. For the cultivated species Abelmoschus esculentus, large (30-50%) and reversible changes in TUV occurred on a diurnal basis, and these adjustments were associated with changes in the concentrations of whole-leaf UV-absorbing compounds and several quercetin glycosides. Similar results were found for two other species (Vicia faba and Solanum lycopersicum), but no such changes were detected in Zea mays. These findings reveal a much more dynamic UV-protection mechanism than previously recognized, raise important questions concerning the costs and benefits of UV-protection strategies in plants and have practical implications for employing UV to enhance crop vigor and quality in controlled environments. © 2015 John Wiley & Sons Ltd.

  1. Studies of ionising radiation induced bystander effects in 3D artificial tissue system and applications for radiation protection

    International Nuclear Information System (INIS)

    Belyakov, Oleg V.; Kuopio Univ.

    2008-01-01

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm should cover both the classical (targeted) and the non-targeted effects. The bystander effect cannot be comprehensively explained on the basis of a single cell reaction. It is well known that an organism is composed of different cell types that interact as functional units in a way to maintain normal tissue function. Therefore the radiation response is not simply the sum of cellular responses as assumed in classical radiobiology, predominantly from studies using cell cultures. Experimental models, which maintain tissue-like intercellular cell signalling and 3D structure, are essential for proper understanding of the bystander effect. Our work relates to experimentation with novel 3D artificial human tissue systems available from MatTek Corporation (Boston, USA). Air-liquid interface culture technique is used to grow artificial tissues, which allow to model conditions present in vivo. The Gray Cancer Institute (Northwood, UK) charged particle microbeam was used to irradiate tissue samples in a known pattern with a known number of 3 He 2+ particles or protons. After irradiation, the tissues models were incubated for 3 days, fixed in 10 % NBF, paraffin embedded and then sliced into 5 μm histological sections located at varying distances from the plane of the irradiated cells. We studied in situ apoptosis and markers of differentiation. Significantly elevated bystander induced apoptosis was observed with 3'-OH DNA end-labelling based technique in 3D artificial tissue systems. Our results also suggested an importance of proliferation and differentiation status for bystander

  2. Photoreactivation of Pseudomonas cepacia after ultraviolet exposure: a potential source of contamination in ultraviolet-treated waters

    International Nuclear Information System (INIS)

    Carson, L.A.; Petersen, N.J.

    1975-01-01

    Cells of a naturally occurring strain of Pseudomonas cepacia grown in distilled water were exposed to ultraviolet radiation. Irradiated samples incubated on membrane filters or in fluid recovery media in the absence of light showed no evidence of dark repair mechanisms. When samples were exposed to fluorescent light ranging from 50 to 950 foot candles (538 to 10,222 lux) of illumination, apparent photo-induced repair of ultraviolet injury resulted in 1- to 4-log increases in viable cells recovered

  3. Ultraviolet and short wavelength visible light exposure: why ultraviolet protection alone is not adequate.

    Science.gov (United States)

    Reichow, Alan W; Citek, Karl; Edlich, Richard F

    2006-01-01

    The danger of exposure to ultraviolet (UV) radiation in both the natural environment and artificial occupational settings has long been recognized by national and international standards committees and worker safety agencies. There is an increasing body of literature that suggests that protection from UV exposure is not enough. Unprotected exposure to the short wavelengths of the visible spectrum, termed the "blue light hazard", is gaining acceptance as a true risk to long-term visual health. Global standards and experts in the field are now warning that those individuals who spend considerable time outdoors should seek sun filter eyewear with high impact resistant lenses that provide 100% UV filtration, high levels of blue light filtration, and full visual field lens/frame coverage as provided by high wrap eyewear. The Skin Cancer Foundation has endorsed certain sunglasses as "product[s]...effective [as] UV filter[s] for the eyes and surrounding skin". However, such endorsement does not necessarily mean that the eyewear meets all the protective needs for outdoor use. There are several brands that offer products with such protective characteristics. Performance sun eyewear by Nike Vision, available in both corrective and plano (nonprescription) forms, is one such brand incorporating these protective features.

  4. Contrasting effects of ultraviolet-A and ultraviolet B exposure on induction of contact sensitivity in human skin

    DEFF Research Database (Denmark)

    Skov, Lone; Hansen, Henrik; Barker, J. N.

    1997-01-01

    Ultraviolet-B (UVB), in addition to direct effects on DNA, induces immunological changes in the skin that predispose to the development of skin cancer. Whether ultraviolet-A (UVA) induces similar changes is unknown. This effect can be investigated in humans in vivo using epicutaneous antigens...... as a model of tumour antigens. Volunteers (n = 46) were randomly assigned to received no sensitization, sensitization with the allergen diphenylcyclopropenone (DPCP) on non-UV-exposed normal skin, or sensitization with DPCP on skin exposed to three minimal erythema doses (MED) of either UVA or UVB radiation...... the immunization rate compared with sensitization on non-irradiated skin (P UVA radiation did not result in a decreased immunization rate compared with non-irradiated skin. These results indicate that in humans erythemagenic...

  5. Application of artificial intelligence to radiation control, (1)

    International Nuclear Information System (INIS)

    Kimura, Yoshitaka; Hasegawa, Keisuke; Ikezawa, Yoshio

    1990-01-01

    Recently artificial intelligence (AI) which has functions of our interpretations and judgments has been applied to various fields of science. In the first application of AI to the transport procedure of the radioactive material, a prototype of expert system was developed with UTI-LISP programming language to appropriately classify mainly the packages and packagings according to regulations for the safe transport of radioactive material. Classification of the packages and packagings for the consignment is mainly determined from input informations such as radionuclides, its activities, states and conveyances through a forward reasoning method of the expert system. The rationalization of practice on our interpretations and judgments for transport of radioactive material including uniformity and reliability of our decision were confirmed as the result of an application to radiation control. (author)

  6. The Role of Macrophage Migration Inhibitory Factor (MIF) in Ultraviolet Radiation-Induced Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Tadamichi [Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, 930-0194, Toyama (Japan)

    2010-08-09

    Ultraviolet (UV) radiation is the most common cause of physical injury to the skin due to environmental damage, and UV exposure substantially increases the risk of actinic damage to the skin. The inflammatory changes induced by acute UV exposure include erythema (sunburn) of the skin, while chronic exposure to solar UV radiation causes photo-aging, immunosuppression, and ultimately, carcinogenesis of the skin. After skin damage by UV radiation, the cells are known to secrete many cytokines, including interleukin (IL)-1, IL-6, tumor necrosis factor (TNF)-α. and macrophage migration inhibitory factor (MIF). MIF was originally identified as a lymphokine that concentrates macrophages at inflammatory loci, and is known to be a potent activator of macrophages in vivo. MIF is considered to play an important role in cell-mediated immunity. Since the molecular cloning of MIF cDNA, MIF has been re-evaluated as a proinflammatory cytokine and pituitary-derived hormone that potentiates endotoxemia. MIF is ubiquitously expressed in various tissues, including the skin. Recent studies have suggested a potentially broader role for MIF in growth regulation because of its ability to antagonize p53-mediated gene activation and apoptosis. This article reviews the latest findings on the roles of MIF with regard to UV-induced skin cancer.

  7. The Role of Macrophage Migration Inhibitory Factor (MIF) in Ultraviolet Radiation-Induced Carcinogenesis

    International Nuclear Information System (INIS)

    Shimizu, Tadamichi

    2010-01-01

    Ultraviolet (UV) radiation is the most common cause of physical injury to the skin due to environmental damage, and UV exposure substantially increases the risk of actinic damage to the skin. The inflammatory changes induced by acute UV exposure include erythema (sunburn) of the skin, while chronic exposure to solar UV radiation causes photo-aging, immunosuppression, and ultimately, carcinogenesis of the skin. After skin damage by UV radiation, the cells are known to secrete many cytokines, including interleukin (IL)-1, IL-6, tumor necrosis factor (TNF)-α. and macrophage migration inhibitory factor (MIF). MIF was originally identified as a lymphokine that concentrates macrophages at inflammatory loci, and is known to be a potent activator of macrophages in vivo. MIF is considered to play an important role in cell-mediated immunity. Since the molecular cloning of MIF cDNA, MIF has been re-evaluated as a proinflammatory cytokine and pituitary-derived hormone that potentiates endotoxemia. MIF is ubiquitously expressed in various tissues, including the skin. Recent studies have suggested a potentially broader role for MIF in growth regulation because of its ability to antagonize p53-mediated gene activation and apoptosis. This article reviews the latest findings on the roles of MIF with regard to UV-induced skin cancer

  8. The Role of Macrophage Migration Inhibitory Factor (MIF in Ultraviolet Radiation-Induced Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Tadamichi Shimizu

    2010-08-01

    Full Text Available Ultraviolet (UV radiation is the most common cause of physical injury to the skin due to environmental damage, and UV exposure substantially increases the risk of actinic damage to the skin. The inflammatory changes induced by acute UV exposure include erythema (sunburn of the skin, while chronic exposure to solar UV radiation causes photo-aging, immunosuppression, and ultimately, carcinogenesis of the skin. After skin damage by UV radiation, the cells are known to secrete many cytokines, including interleukin (IL-1, IL-6, tumor necrosis factor (TNF-α. and macrophage migration inhibitory factor (MIF. MIF was originally identified as a lymphokine that concentrates macrophages at inflammatory loci, and is known to be a potent activator of macrophages in vivo. MIF is considered to play an important role in cell-mediated immunity. Since the molecular cloning of MIF cDNA, MIF has been re-evaluated as a proinflammatory cytokine and pituitary-derived hormone that potentiates endotoxemia. MIF is ubiquitously expressed in various tissues, including the skin. Recent studies have suggested a potentially broader role for MIF in growth regulation because of its ability to antagonize p53-mediated gene activation and apoptosis. This article reviews the latest findings on the roles of MIF with regard to UV-induced skin cancer.

  9. Assessment of Health Consequences of Steel Industry Welders’ Occupational Exposure to Ultraviolet Radiation

    Science.gov (United States)

    Zamanian, Zahra; Mortazavi, Saied Mohammad Javad; Asmand, Ebrahim; Nikeghbal, Kiana

    2015-01-01

    Background: Welding is among the most important frequently used processes in the industry with a wide range of applications from the food industry to aerospace and from precision tools to shipbuilding. The aim of this study was to assess the level of steel industry welders’ exposure to ultraviolet (UV) radiation and to investigate the health impacts of these exposures. Methods: In this case–control study, we measured the intensity of UV at the workers’ wrist in Fars Steel Company through manufacture of different types of heavy metal structures, using UV-meter model 666230 made by Leybold Co., from Germany. Results: The population under the study comprised 400 people including 200 welders as the exposed group and 200 nonwelders as the unexposed group. The results of the questionnaire were analyzed using SPSS software, version 19. The average, standard deviation, maximum and minimum of the UV at the welders’ wrist were 0.362, 0.346, 1.27, and 0.01 μW/cm2, respectively. There was a significantly (P radiation level, and using personal protective equipment seem indispensable. As exposure to UV radiation can be linked to different types of skin cancer, skin aging, and cataract, welders should be advised to decrease their occupational exposures. PMID:26900437

  10. Assessment of Health Consequences of Steel Industry Welders' Occupational Exposure to Ultraviolet Radiation.

    Science.gov (United States)

    Zamanian, Zahra; Mortazavi, Saied Mohammad Javad; Asmand, Ebrahim; Nikeghbal, Kiana

    2015-01-01

    Welding is among the most important frequently used processes in the industry with a wide range of applications from the food industry to aerospace and from precision tools to shipbuilding. The aim of this study was to assess the level of steel industry welders' exposure to ultraviolet (UV) radiation and to investigate the health impacts of these exposures. In this case-control study, we measured the intensity of UV at the workers' wrist in Fars Steel Company through manufacture of different types of heavy metal structures, using UV-meter model 666230 made by Leybold Co., from Germany. The population under the study comprised 400 people including 200 welders as the exposed group and 200 nonwelders as the unexposed group. The results of the questionnaire were analyzed using SPSS software, version 19. The average, standard deviation, maximum and minimum of the UV at the welders' wrist were 0.362, 0.346, 1.27, and 0.01 μW/cm(2), respectively. There was a significantly (P radiation level, and using personal protective equipment seem indispensable. As exposure to UV radiation can be linked to different types of skin cancer, skin aging, and cataract, welders should be advised to decrease their occupational exposures.

  11. 21 CFR 878.4630 - Ultraviolet lamp for dermatologic disorders.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet lamp for dermatologic disorders. 878.4630 Section 878.4630 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... disorders is a device (including a fixture) intended to provide ultraviolet radiation of the body to...

  12. Ultraviolet-B radiation enhancement in dielectric barrier discharge based xenon chloride exciplex source by air

    Energy Technology Data Exchange (ETDEWEB)

    Gulati, P., E-mail: pgulati1512@gmail.com [CSIR-Central Electronics Engineering Research Institute (CSIR-CEERI), Pilani, Rajasthan-333031 (India); Department of Physics, Banasthali University, P.O. Banasthali Vidyapith, Rajasthan 304022 (India); Prakash, R.; Pal, U. N.; Kumar, M. [CSIR-Central Electronics Engineering Research Institute (CSIR-CEERI), Pilani, Rajasthan-333031 (India); Vyas, V. [Department of Physics, Banasthali University, P.O. Banasthali Vidyapith, Rajasthan 304022 (India)

    2014-07-07

    A single barrier dielectric barrier discharge tube of quartz with multi-strip Titanium-Gold (Ti-Au) coatings have been developed and utilized for ultraviolet-B (UV-B) radiation production peaking at wavelength 308 nm. The observed radiation at this wavelength has been examined for the mixtures of the Xenon together with chlorine and air admixtures. The gas mixture composition, chlorine gas content, total gas pressure, and air pressure dependency of the UV intensity, has been analyzed. It is found that the larger concentration of Cl{sub 2} deteriorates the performance of the developed source and around 2% Cl{sub 2} in this source produced optimum results. Furthermore, an addition of air in the xenon and chlorine working gas environment leads to achieve same intensity of UV-B light but at lower working gas pressure where significant amount of gas is air.

  13. Ultraviolet-B radiation enhancement in dielectric barrier discharge based xenon chloride exciplex source by air

    Science.gov (United States)

    Gulati, P.; Prakash, R.; Pal, U. N.; Kumar, M.; Vyas, V.

    2014-07-01

    A single barrier dielectric barrier discharge tube of quartz with multi-strip Titanium-Gold (Ti-Au) coatings have been developed and utilized for ultraviolet-B (UV-B) radiation production peaking at wavelength 308 nm. The observed radiation at this wavelength has been examined for the mixtures of the Xenon together with chlorine and air admixtures. The gas mixture composition, chlorine gas content, total gas pressure, and air pressure dependency of the UV intensity, has been analyzed. It is found that the larger concentration of Cl2 deteriorates the performance of the developed source and around 2% Cl2 in this source produced optimum results. Furthermore, an addition of air in the xenon and chlorine working gas environment leads to achieve same intensity of UV-B light but at lower working gas pressure where significant amount of gas is air.

  14. Effects of radiation and temperature on gallium nitride (GaN) metal-semiconductor-metal ultraviolet photodetectors

    Science.gov (United States)

    Chiamori, Heather C.; Angadi, Chetan; Suria, Ateeq; Shankar, Ashwin; Hou, Minmin; Bhattacharya, Sharmila; Senesky, Debbie G.

    2014-06-01

    The development of radiation-hardened, temperature-tolerant materials, sensors and electronics will enable lightweight space sub-systems (reduced packaging requirements) with increased operation lifetimes in extreme harsh environments such as those encountered during space exploration. Gallium nitride (GaN) is a ceramic, semiconductor material stable within high-radiation, high-temperature and chemically corrosive environments due to its wide bandgap (3.4 eV). These material properties can be leveraged for ultraviolet (UV) wavelength photodetection. In this paper, current results of GaN metal-semiconductor-metal (MSM) UV photodetectors behavior after irradiation up to 50 krad and temperatures of 15°C to 150°C is presented. These initial results indicate that GaN-based sensors can provide robust operation within extreme harsh environments. Future directions for GaN-based photodetector technology for down-hole, automotive and space exploration applications are also discussed.

  15. Repair of ultraviolet light-induced damage in Micrococcus radiophilus, and extremely resistant microorganism

    International Nuclear Information System (INIS)

    Lavin, M.F.; Jenkins, A.; Kidson, C.

    1976-01-01

    Repair of ultraviolet radiation damage was examined in an extremely radioresistant organism, Micrococcus radiophilus. Measurement of the number of thymine-containing dimers formed as a function of ultraviolet dose suggests that the ability of this organism to withstand high doses of ultraviolet radiation (20,000 ergs/mm 2 ) is not related to protective screening by pigments. M. radiophilus carries out a rapid excision of thymine dimers at doses of ultraviolet light up to 10,000 ergs/mm 2 . Synthesis of deoxyribonucleic acid is reduced after irradiation, but after removal of photodamage the rate approaches that in unirradiated cells. A comparison is drawn with Micrococcus luteus and M. radiodurans. We conclude that the extremely high resistance to ultraviolet irradiation in M. radiophilus is at least partly due to the presence of an efficient excision repair system

  16. Physical, biochemical and physiological effects of ultraviolet radiation on Brassica napus and Phaseolus vulgaris

    International Nuclear Information System (INIS)

    Cen Yan-Ping.

    1993-01-01

    In order to follow some of the changes induced by ultraviolet-B (UV-B, 280-320 nm) radiation in Phaseolus vulgaris and Brassica napus, experiments were designed to localize sites of changes in leaves and to correlate some of the physiological and biochemical changes with penetration of UV-B radiation. B.napus was exposed to 8.9 kJ m -2 day -1 biologically effective UV-B radiation (UV-B BE ). The penetration of UV-B radiation into the leaf was followed using a quartz fibre optic microprobe. Monochromatic radiation at 310 nm was decreased by ca 50 and 34% in the adaxial and abaxial epidermis, respectively, in plants not exposed to UV-B, whereas the radiation was decreased by ca 70 and 42%, respectively, in the same region in UV-treated plants. Polychromatic radiation showed a wavelength dependent change mainly for the collimated radiation. The results correlated with the distribution of phenolic compounds analysed from 40 μm paradermal leaf sections. The first adaxial section (40μm) contained 35% of the whole leaf sample flavonoid glycosides in control plants, and 66% in UV-treated plants. Hydroxycinnamic acid derivatives increased by 26% in UV-treated plants relative to controls. The ratio of quercetin to kaempferol derivatives increased from 0.11 in controls to 0.91 in leaves of UV-treated plants. The leaf epidermis protected the inner leaf tissue where most of the photosynthetic apparatus is located. P. vulgaris was subjected to 6.17 kJ m -2 day -1 UV-B BE with different levels of visible light. The largest UV-induced changes in photosynthesis, chlorophyll, carotenoids, UV-screening pigments, and surface leaf reflectance occurred under growth conditions of low levels of visible light together with UV radiation

  17. Physical, biochemical and physiological effects of ultraviolet radiation on Brassica napus and Phaseolus vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Cen Yan-Ping

    1993-12-31

    In order to follow some of the changes induced by ultraviolet-B (UV-B, 280-320 nm) radiation in Phaseolus vulgaris and Brassica napus, experiments were designed to localize sites of changes in leaves and to correlate some of the physiological and biochemical changes with penetration of UV-B radiation. B.napus was exposed to 8.9 kJ m{sup -2} day{sup -1} biologically effective UV-B radiation (UV-B{sub BE}). The penetration of UV-B radiation into the leaf was followed using a quartz fibre optic microprobe. Monochromatic radiation at 310 nm was decreased by ca 50 and 34% in the adaxial and abaxial epidermis, respectively, in plants not exposed to UV-B, whereas the radiation was decreased by ca 70 and 42%, respectively, in the same region in UV-treated plants. Polychromatic radiation showed a wavelength dependent change mainly for the collimated radiation. The results correlated with the distribution of phenolic compounds analysed from 40 {mu}m paradermal leaf sections. The first adaxial section (40{mu}m) contained 35% of the whole leaf sample flavonoid glycosides in control plants, and 66% in UV-treated plants. Hydroxycinnamic acid derivatives increased by 26% in UV-treated plants relative to controls. The ratio of quercetin to kaempferol derivatives increased from 0.11 in controls to 0.91 in leaves of UV-treated plants. The leaf epidermis protected the inner leaf tissue where most of the photosynthetic apparatus is located. P. vulgaris was subjected to 6.17 kJ m{sup -2} day{sup -1} UV-B{sub BE} with different levels of visible light. The largest UV-induced changes in photosynthesis, chlorophyll, carotenoids, UV-screening pigments, and surface leaf reflectance occurred under growth conditions of low levels of visible light together with UV radiation.

  18. Sensitivity of the vibrios to ultraviolet-radiation

    International Nuclear Information System (INIS)

    Banerjee, S.K.; Chatterjee, S.N.

    1977-01-01

    The ultraviolet-inactivation kinetics of a number of strains of Vibrio cholerae (classical), Vibrio cholerae (el tor), NAG vibrios and Vibrio parahaemolyticus were investigated. Statistical analyses revealed significant differences between any two of the four types of vibrio in respect of their sensitivity to U.V. (author)

  19. Symposium on diseases related to ultraviolet radiation: A risk-management approach

    International Nuclear Information System (INIS)

    Gibbons, L.

    1992-01-01

    A symposium on diseases related to ultraviolet radiation (UVR), sponsored by the Laboratory Centre for Disease Control was attended by 50 national and international experts in the fields of dermatology, ophthalmology and epidemiology, as well as representatives from various national and provincial public health organizations. The objectives of the symposium were as follows: to review the evidence relating UVR to the incidence of melanoma of the skin and eye, non melanotic cancer of the skin and lip, nonmalignant skin conditions and cataract; to review the effectiveness of primary prevention and early detection of UVR-related diseases; and to recommend strategies for risk management through regulation, public education and screening programs, as well as research priorities. Fourteen experts presented papers on issues related to UVR exposure. After the presentations the participants met in working groups to discuss questions pertaining to the identification, assessment and management of health risks relating to UVR. (author)

  20. A novel sensor array for field based ocular ultraviolet radiation measurements

    International Nuclear Information System (INIS)

    Fleming, D. P.; Walsh, J. E.; Moore, L. A.; Bergmanson, J. P.; McMahon, D.

    2006-01-01

    The intensification of terrestrial solar ultraviolet radiation (UVR) due to the diminution of the ozone layer has promoted a variety of research into establishing the impact of this elevated potential dose of UVR on biological tissues. Certain anterior ocular tissues have been found to be susceptible to damage by incident UVR and potentially blinding diseases such as pterygium are thought to be a direct result of absorbed UVR at the nasal limbus. There is a need for more accurate quantification and localisation of incident UVR at the anterior ocular surface. A novel solar blind photodiode sensor array system has been designed, constructed and tested for this purpose. Initial measurements to quantify the irradiance across the anterior ocular surface within the latitudes known as the 'pterygium belt' provide us with a set of core data for different head orientations and tilt angles and indicate the accuracy and stability of the system. (authors)

  1. The influence of UV radiation on protistan evolution

    Science.gov (United States)

    Rothschild, L. J.

    1999-01-01

    Ultraviolet radiation has provided an evolutionary challenge to life on Earth. Recent increases in surficial ultraviolet B fluxes have focused attention on the role of UV radiation in protistan ecology, cancer, and DNA damage. Exploiting this new wealth of data, I examine the possibility that ultraviolet radiation may have played a significant role in the evolution of the first eukaryotes, that is, protists. Protists probably arose well before the formation of a significant ozone shield, and thus were probably subjected to substantial ultraviolet A, ultraviolet B, and ultraviolet C fluxes early in their evolution. Evolution consists of the generation of heritable variations and the subsequent selection of these variants. Ultraviolet radiation has played a role both as a mutagen and as a selective agent. In its role as a mutagen, it may have been crucial in the origin of sex and as a driver of molecular evolution. As a selective agent, its influence has been broad. Discussed in this paper are the influence of ultraviolet radiation on biogeography, photosynthesis, and desiccation resistance.

  2. An artificial-vision responsive to patient motions during computer controlled radiation therapy

    International Nuclear Information System (INIS)

    Kalend, A.M.; Shimoga, K.; Kanade, T.; Greenberger, J.S.

    1997-01-01

    Purpose/Objectives: Automated precision radiotherapy using multiple conformal and modulated beams, requires monitoring of patient movements during irradiation. Immobilizers relying on patient cooperating in cradles have somewhat reduced positional uncertainties, but others including breathing are largely unknown. We built an artificial vision (AV) device for real-time vision of patient movements, their tracking and quantification. Method and Materials: The Artificial Vision System's 'acuity' and 'reflex' were evaluated in terms of imaged skin spatial resolutions and temporal dispersions measured using a mannequin and a fiduciated harmonic oscillator placed at 100cm isocenter. The device traced skin motion even in poorly lighted rooms without use of explicit skin fiduciation, or using standard radiotherapy skin tattoos. Results: The AV system tracked human skin at vision rates approaching 30Hz and sensitivity of 2mm. It successfully identified and tracked independent skin marks, either natural tattoos or artificial fiducials. Three alert levels triggered when patient movement exceeded preset displacements (2mm/30Hz), motion velocities (5m/sec) or acceleration (2m/sec 2 ). Conclusion: The AV system trigger should suit for patient ventilatory gating and safety interlocking of treatment accelerators, in order to modulate, interrupt, or abort radiation during dynamic therapy

  3. The Formation of a Power Multi-Pulse Extreme Ultraviolet Radiation in the Pulse Plasma Diode of Low Pressure

    Directory of Open Access Journals (Sweden)

    Ievgeniia V. Borgun

    2013-01-01

    Full Text Available In this paper results are presented on experimental studies of the temporal characteristics of spike extreme ultraviolet (EUV radiation in the spectral range of 12.2 ÷ 15.8 nm from the anode region of high-current (I = 40 kA pulsed discharges in tin vapor. It is observed that the intense multi-spike radiation in this range arises at an inductive stage of the discharge. It has been shown that the radiation spikes correlate with the sharp increase of active resistance and of pumped power, due to plasma heating by an electron beam, formed in the double layer of charged particles. It has been observed that for large number of spikes the conversion efficiency of pumped energy into radiationat double layer formation is essentially higher in comparison with collisional heating.

  4. Solar ultraviolet radiation is necessary to enhance grapevine fruit ripening transcriptional and phenolic responses.

    Science.gov (United States)

    Carbonell-Bejerano, Pablo; Diago, Maria-Paz; Martínez-Abaigar, Javier; Martínez-Zapater, José M; Tardáguila, Javier; Núñez-Olivera, Encarnación

    2014-07-09

    Ultraviolet (UV) radiation modulates secondary metabolism in the skin of Vitis vinifera L. berries, which affects the final composition of both grapes and wines. The expression of several phenylpropanoid biosynthesis-related genes is regulated by UV radiation in grape berries. However, the complete portion of transcriptome and ripening processes influenced by solar UV radiation in grapes remains unknown. Whole genome arrays were used to identify the berry skin transcriptome modulated by the UV radiation received naturally in a mid-altitude Tempranillo vineyard. UV radiation-blocking and transmitting filters were used to generate the experimental conditions. The expression of 121 genes was significantly altered by solar UV radiation. Functional enrichment analysis of altered transcripts mainly pointed out that secondary metabolism-related transcripts were induced by UV radiation including VvFLS1, VvGT5 and VvGT6 flavonol biosynthetic genes and monoterpenoid biosynthetic genes. Berry skin phenolic composition was also analysed to search for correlation with gene expression changes and UV-increased flavonols accumulation was the most evident impact. Among regulatory genes, novel UV radiation-responsive transcription factors including VvMYB24 and three bHLH, together with known grapevine UV-responsive genes such as VvMYBF1, were identified. A transcriptomic meta-analysis revealed that genes up-regulated by UV radiation in the berry skin were also enriched in homologs of Arabidopsis UVR8 UV-B photoreceptor-dependent UV-B -responsive genes. Indeed, a search of the grapevine reference genomic sequence identified UV-B signalling pathway homologs and among them, VvHY5-1, VvHY5-2 and VvRUP were up-regulated by UV radiation in the berry skin. Results suggest that the UV-B radiation-specific signalling pathway is activated in the skin of grapes grown at mid-altitudes. The biosynthesis and accumulation of secondary metabolites, which are appreciated in winemaking and

  5. Radiation and radiation protection; Strahlung und Strahlenschutz

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomaeus, Melanie (comp.)

    2017-04-15

    The publication of the Bundesamt fuer Strahlenschutz covers the following issues: (i) Human beings in natural and artificial radiation fields; (ii) ionizing radiation: radioactivity and radiation, radiation exposure and doses; measurement of ionizing radiation, natural radiation sources, artificial radiation sources, ionizing radiation effects on human beings, applied radiation protection, radiation exposure of the German population, radiation doses in comparison; (iii) non-ionizing radiation; low-frequency electric and magnetic fields, high-frequency electromagnetic fields, optical radiation; (iiii) glossary, (iv) units and conversion.

  6. Larval performance of the mustard leaf beetle (Phaedon cochleariae, Coleoptera, Chrysomelidae) on white mustard (Sinapis alba) and watercress (Nasturtium officinale) leaves in dependence of plant exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Reifenrath, Kerstin; Mueller, Caroline

    2009-01-01

    Short-term exposure to ambient or attenuated ultraviolet (UV) radiation resulted in shifts in plant metabolite concentrations of the Brassicaceae Sinapis alba and Nasturtium officinale. Leaf quality also varied between plant species and within species due to age. Larvae of the oligophagous leaf beetle Phaedon cochleariae were raised on these different host leaves, in order to investigate the effects of variable plant chemistry on this herbivore. The performance of P. cochleariae was influenced by chemical differences between and within plant species but it responded with high plasticity to plants stressed by ultraviolet radiation. Body mass increase and developmental times of larvae were exclusively affected by plant species and leaf-age. However, developmental differences were fully compensated in the pupal stage. We suggest that the plasticity of herbivores may depend on the degree of specialisation, and insect performance may not necessarily be altered by stress-induced host plants. - The larval performance of an oligophagous leaf beetle is influenced by chemical differences between and within plant species but responds with high plasticity to plants stressed by ultraviolet radiation.

  7. Comparison of theory with atomic oxygen 130.4 nm radiation data from the Bow Shock ultraviolet 2 rocket flight

    Science.gov (United States)

    Levin, Deborah A.; Candler, Graham V.; Collins, Robert J.; Howlett, Carl L.; Espy, Patrick; Whiting, Ellis; Park, Chul

    1993-01-01

    Comparison is made between the results obtained from a state-of-the-art flow and radiative model and bow shock vacuum ultraviolet (VUV) data obtained the recent Bow Shock 2 Flight Experiment. An extensive data set was obtained from onboard rocket measurements at a reentry speed of 5 km/sec between the altitudes of approximately 65-85 km. A description of the NO photoionization cell used, the data, and the interpretation of the data will be presented. The primary purpose of the analyses is to assess the utility of the data and to propose a radiation model appropriate to the flight conditions of Bow Shock 2. Theoretical predictions based on flow modeling discussed in earlier work and a new radiation model are compared with data.

  8. Modulation of interferon-gamma-induced HLA-DR expression on the human keratinocyte cell line SCC-13 by ultraviolet radiation

    International Nuclear Information System (INIS)

    Khan, I.U.; Boehm, K.D.; Elmets, C.A.

    1993-01-01

    Cell surface expression of major histocompatibility determinants on epidermal keratinocytes is a characteristic feature of a number of inflammatory dermatoses and in all likelihood is caused by diffusion of human leukocyte antigen (HLA)-DR-inducing cytokines from cells present in the dermal mononuclear cell infiltrate. Many of these same disorders respond to ultraviolet (UV) radiation phototherapy. Using the human SCC-13 keratinocyte cell line as a model, UV radiation was found to inhibit interferon-gamma-induced HLA-DR expression. Inhibition correlated closely with decreased steady-state levels of HLA-DR mRNA. These findings provide evidence that the therapeutic effect of UV radiation phototherapy may be mediated by its capacity to down-regulate cytokine-induced keratinocyte HLA-DR expression. (Author)

  9. Modeling the survivability of brucella to exposure of Ultraviolet radiation and temperature

    Science.gov (United States)

    Howe, R.

    Accumulated summation of daily Ultra Violet-B (UV-B = 290? to 320 ? ) data? from The USDA Ultraviolet Radiation Monitoring Program show good correlation (R^2 = 77%) with daily temperature data during the five month period from February through June, 1998. Exposure of disease organisms, such as brucella to the effects of accumulated UV-B radiation, can be modeled for a 5 month period from February through June, 1998. Estimates of a lethal dosage for brucell of UV-B in the environment is dependent on minimum/maximum temperature and Solar Zenith Angle for the time period. The accumulated increase in temperature over this period also effects the decomposition of an aborted fetus containing brucella. Decomposition begins at some minimum daily temperature at 27 to 30 degrees C and peaks at 39 to 40C. It is useful to view the summation of temperature as a threshold for other bacteria growth, so that accumulated temperature greater than some value causes decomposition through competition with other bacteria and brucella die from the accumulated effects of UV-B, temperature and organism competition. Results of a study (Cook 1998) to determine survivability of brucellosis in the environment through exposure of aborted bovine fetuses show no one cause can be attributed to death of the disease agent. The combination of daily increase in temperature and accumulated UV-B radiation reveal an inverse correlation to survivability data and can be modeled as an indicator of brucella survivability in the environment in arid regions.

  10. Protective Effect of Nitric Oxide (NO against Oxidative Damage in Larix gmelinii Seedlings under Ultraviolet-B Irradiation

    Directory of Open Access Journals (Sweden)

    Haiqing Hu

    2016-10-01

    Full Text Available Ultraviolet-B (UV-B stress appears to be more striking than other research works because of the thin ozone layer. The protective influence of an exogenous nitric oxide donor and sodium nitroprusside (SNP on the growth properties of Larix gmelinii seedlings was investigated under ultraviolet-B radiation conditions. The results indicated that 0.1 mM SNP could effectively alleviate the damage caused by ultraviolet-B radiation, and improved the seedling growth properties, the relative water content, and photosynthetic pigment content in leaves. Additionally, the photosynthetic capacity and antioxidant enzyme activity were increased during the exposure. On the contrary, the damage caused by active oxygen was decreased in SNP-treated seedling leaves. The damage caused by ultraviolet-B radiation was slightly reduced after treating with 0.01 mM SNP. Nevertheless, treatment with 0.5 mM SNP had a negative effect under ultraviolet-B radiation. Furthermore, supplementing NO (nitric oxide improved the photosynthetic capacity and antioxidant enzyme activity and alleviated the damage of caused by active oxygen. The best effective concentration of SNP was 0.1 mM. Therefore, a suitable amount of exogenous NO can protect the Larix gmelinii seedlings and increase their tolerance to ultraviolet-B radiation.

  11. Laser-produced lithium plasma as a narrow-band extended ultraviolet radiation source for photoelectron spectroscopy.

    Science.gov (United States)

    Schriever, G; Mager, S; Naweed, A; Engel, A; Bergmann, K; Lebert, R

    1998-03-01

    Extended ultraviolet (EUV) emission characteristics of a laser-produced lithium plasma are determined with regard to the requirements of x-ray photoelectron spectroscopy. The main features of interest are spectral distribution, photon flux, bandwidth, source size, and emission duration. Laser-produced lithium plasmas are characterized as emitters of intense narrow-band EUV radiation. It can be estimated that the lithium Lyman-alpha line emission in combination with an ellipsoidal silicon/molybdenum multilayer mirror is a suitable EUV source for an x-ray photoelectron spectroscopy microscope with a 50-meV energy resolution and a 10-mum lateral resolution.

  12. Assessing the effects of ultraviolet radiation on the photosynthetic potential in Archean marine environments

    Science.gov (United States)

    Avila-Alonso, Dailé; Baetens, Jan M.; Cardenas, Rolando; de Baets, Bernard

    2017-07-01

    In this work, the photosynthesis model presented by Avila et al. in 2013 is extended and more scenarios inhabited by ancient cyanobacteria are investigated to quantify the effects of ultraviolet (UV) radiation on their photosynthetic potential in marine environments of the Archean eon. We consider ferrous ions as blockers of UV during the Early Archean, while the absorption spectrum of chlorophyll a is used to quantify the fraction of photosynthetically active radiation absorbed by photosynthetic organisms. UV could have induced photoinhibition at the water surface, thereby strongly affecting the species with low light use efficiency. A higher photosynthetic potential in early marine environments was shown than in the Late Archean as a consequence of the attenuation of UVC and UVB by iron ions, which probably played an important role in the protection of ancient free-floating bacteria from high-intensity UV radiation. Photosynthetic organisms in Archean coastal and ocean environments were probably abundant in the first 5 and 25 m of the water column, respectively. However, species with a relatively high efficiency in the use of light could have inhabited ocean waters up to a depth of 200 m and show a Deep Chlorophyll Maximum near 60 m depth. We show that the electromagnetic radiation from the Sun, both UV and visible light, could have determined the vertical distribution of Archean marine photosynthetic organisms.

  13. Comparative mutagenesis and interaction between near-ultraviolet (313- to 405-nm) and far-ultraviolet (254-nm) radiation in Escherichia coli strains with differing repair capabilities

    International Nuclear Information System (INIS)

    Turner, M.A.; Webb, R.B.

    1981-01-01

    Comparative mutagenesis and possible synergistic interaction between broad-spectrum (313- to 405-nm) near-ultraviolet (black light bulb [BLB]) radiation and 254-nm radiation were studied in Escherichia coli strains WP2 (wild type), WP2s (uvrA), WP10 (recA), WP6 (polA), WP6s (polA uvrA), WP100 (uvrA recA), and WP5 (lexA). With BLB radiation, strains WP2s and WP6s demonstrated a high level of mutagenesis, whereas strains WP2, WP5, WP6, WP10, and WP100 did not demonstrate significant mutagenesis. In contrast, 254-nm radiation was mutagenic in strains WP2, WP2s, WP6, and WP6s, but strains WP5, WP10, and WP100 were not significantly mutated. The absence of mutagenesis by BLB radiation in lexA and recA strains WP10, WP5, and WP100 suggests that lex + rec + repair may play a major role in mutagenesis by both BLB and 254-nm radiation. The hypothesis that BLB radiation selectively inhibits rec + lex + repair was tested by sequential BLB-254 nm radiation. With strain WP2, a fluence of 30 J/m 2 at 254 nm induced trp + revertants at a frequency of 15 x 10 -6 . However, when 10 5 J/m 2 or more BLB radiation preceded the 254-nm exposure, no trp + revertants could be detected. A similar inhibition of 254-nm mutagenesis was observed with strain WP6 (polA). However, strains WP2s (uvrA) and WP6s (polA uvrA) showed enhanced 254-nm mutagenesis when a prior exposure to BLB radiation was given

  14. Changes in properties of DNA caused by gamma and ultraviolet radiation. Dependence of conformational changes on the chemical nature of the damage

    Energy Technology Data Exchange (ETDEWEB)

    Vorlickova, M; Palacek, E [Ceskoslovenska Akademie Ved, Brno. Biofysikalni Ustav

    1978-02-16

    Changes in the pulse-polarographic behaviour and circular dichroism spectra of DNA were investigated after gamma and ultraviolet irradiations and after degradation by DNAase I. It was found that moderate doses of radiation cause local conformational changes in the double helix which are dependent on the chemical nature of the damage. Only the accumulation of structural changes after high doses of the radiations or after extensive enzymic treatment may cause formation of single-standed regions in DNA.

  15. Interdependence between body surface area and ultraviolet B dose in vitamin D production

    DEFF Research Database (Denmark)

    Bogh, M K B; Schmedes, Anne; Philipsen, P A

    2011-01-01

    Ultraviolet (UV) B radiation increases serum vitamin D level expressed as 25-hydroxyvitamin-D(3) [25(OH)D], but the relationship to body surface area and UVB dose needs investigation.......Ultraviolet (UV) B radiation increases serum vitamin D level expressed as 25-hydroxyvitamin-D(3) [25(OH)D], but the relationship to body surface area and UVB dose needs investigation....

  16. Evolution of solar ultraviolet luminosity

    International Nuclear Information System (INIS)

    Zahnle, K.J.; Walker, J.C.G.

    1982-01-01

    In view of the major role of the sun in defining the properties of planetary atmospheres, their evolution cannot be fully understood outside the context of an evolving sun. The ultraviolet radiation is especially interesting because of its strong interaction with planetary atmospheres. We use astronomical observation of stars that are analogous to the sun in order to reconstruct a tentative account of the evolution of solar UV luminosity. A wealth of evidence indicates that the young sun was a much more powerful source of energetic particles and radiation than it is today. While on the main sequence, solar activity has declined as an inverse power law of age (between t -5 and t/sup -1.2/) as a consequence of angular momentum loss to the solar wind. Recent IUE satellite observations of premain sequence stars suggest that before the sun reached the main sequence (at an age of about 50 m.y.), it may have emitted as much as 10 4 times as much ultraviolet radiation (γ<2000 A) than it does today. These results could impact our understanding of the photochemistry and escape of constituents of primordial planetary atmospheres

  17. Action spectra affect variability of the climatology of biologically effective ultraviolet radiation on cloud-free days.

    Science.gov (United States)

    Grifoni, D; Zipoli, G; Sabatini, F; Messeri, G; Bacci, L

    2013-12-01

    Action spectrum (AS) describes the relative effectiveness of ultraviolet (UV) radiation in producing biological effects and allows spectral UV irradiance to be weighted in order to compute biologically effective UV radiation (UVBE). The aim of this research was to study the seasonal and latitudinal distribution over Europe of daily UVBE doses responsible for various biological effects on humans and plants. Clear sky UV radiation spectra were computed at 30-min time intervals for the first day of each month of the year for Rome, Potsdam and Trondheim using a radiative transfer model fed with climatological data. Spectral data were weighted using AS for erythema, vitamin D synthesis, cataract and photokeratitis for humans, while the generalised plant damage and the plant damage AS were used for plants. The daily UVBE doses for the above-mentioned biological processes were computed and are analysed in this study. The patterns of variation due to season (for each location) and latitude (for each date) resulted as being specific for each adopted AS. The biological implications of these results are briefly discussed highlighting the importance of a specific UVBE climatology for each biological process.

  18. Action spectra affect variability of the climatology of biologically effective ultraviolet radiation on cloud-free days

    International Nuclear Information System (INIS)

    Grifoni, D.; Zipoli, G.; Sabatini, F.; Messeri, G.; Bacci, L.

    2013-01-01

    Action spectrum (AS) describes the relative effectiveness of ultraviolet (UV) radiation in producing biological effects and allows spectral UV irradiance to be weighted in order to compute biologically effective UV radiation (UVBE). The aim of this research was to study the seasonal and latitudinal distribution over Europe of daily UVBE doses responsible for various biological effects on humans and plants. Clear sky UV radiation spectra were computed at 30-min time intervals for the first day of each month of the year for Rome, Potsdam and Trondheim using a radiative transfer model fed with climatological data. Spectral data were weighted using AS for erythema, vitamin D synthesis, cataract and photo-keratitis for humans, while the generalised plant damage and the plant damage AS were used for plants. The daily UVBE doses for the above-mentioned biological processes were computed and are analysed in this study. The patterns of variation due to season (for each location) and latitude (for each date) resulted as being specific for each adopted AS. The biological implications of these results are briefly discussed highlighting the importance of a specific UVBE climatology for each biological process. (authors)

  19. Intentional exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Kivisakk, E.

    1987-01-01

    Exposure to UV radiation can cause a number of detrimental effects to human health. Some of these are particularly grave, as for instance the induction of skin cancer. Nevertheless, intentional exposure to UV radiation is commonly practiced for many purposes, ranging from medical treatment to merely a simple form of pastime. From the radiation point of view, the risks associated with exposure to UV radiation in any particular application should be carefully considered, and only accepted if they are obviously compensated by the benefits of the irradiation. This is not always the case today, to some extent due to shortage of information about the effect of UV radiation - especially on a long term basis

  20. Supervised artificial neural network-based method for conversion of solar radiation data (case study: Algeria)

    Science.gov (United States)

    Laidi, Maamar; Hanini, Salah; Rezrazi, Ahmed; Yaiche, Mohamed Redha; El Hadj, Abdallah Abdallah; Chellali, Farouk

    2017-04-01

    In this study, a backpropagation artificial neural network (BP-ANN) model is used as an alternative approach to predict solar radiation on tilted surfaces (SRT) using a number of variables involved in physical process. These variables are namely the latitude of the site, mean temperature and relative humidity, Linke turbidity factor and Angstrom coefficient, extraterrestrial solar radiation, solar radiation data measured on horizontal surfaces (SRH), and solar zenith angle. Experimental solar radiation data from 13 stations spread all over Algeria around the year (2004) were used for training/validation and testing the artificial neural networks (ANNs), and one station was used to make the interpolation of the designed ANN. The ANN model was trained, validated, and tested using 60, 20, and 20 % of all data, respectively. The configuration 8-35-1 (8 inputs, 35 hidden, and 1 output neurons) presented an excellent agreement between the prediction and the experimental data during the test stage with determination coefficient of 0.99 and root meat squared error of 5.75 Wh/m2, considering a three-layer feedforward backpropagation neural network with Levenberg-Marquardt training algorithm, a hyperbolic tangent sigmoid and linear transfer function at the hidden and the output layer, respectively. This novel model could be used by researchers or scientists to design high-efficiency solar devices that are usually tilted at an optimum angle to increase the solar incident on the surface.

  1. Desinfecção de água de chuva por radiação ultravioleta Disinfection of rainwater by ultraviolet radiation

    Directory of Open Access Journals (Sweden)

    Elisabeth Wisbeck

    2011-12-01

    Full Text Available O objetivo deste trabalho foi avaliar o tratamento de água de chuva, de duas regiões industriais de Joinville (SC, por radiação ultravioleta. O reator operou em processo contínuo, de modo que cada partícula permanecesse sob radiação por 60 segundos. As amostras de água foram analisadas em termos de coliformes totais, coliformes termotolerantes e bactérias heterotróficas antes do tratamento por ultravioleta, após o tratamento e após tratadas e armazenadas por 24, 48 e 72 horas. Verificou-se a eficiência da desinfecção de água de chuva direta e de telhado por radiação ultravioleta com a inativação de 100% dos coliformes totais e dos coliformes termotolerantes e o não recrescimento desses micro-organismos em amostras tratadas e estocados por até 72 horas, no entanto, bactérias heterotróficas persistiram e foram identificadas após 24, 48 e 72 horas ao tratamento.The objective of this study was to evaluate the treatment of rainwater in two industrial regions in Joinville (SC, Brazil by ultraviolet radiation. The reactor was operating in continuous process with each particle remaining under radiation for 60 seconds. The samples were evaluated in terms of total coliforms, fecal coliform and heterotrophic bacteria prior to ultraviolet treatment, after treatment and further treated and stored for 24, 48 and 72 hours. The efficiency of disinfection of direct rainwater and that collected from roofing by ultraviolet radiation was verified with 100% inactivation of total coliforms and fecal coliform and these microorganisms did not reappear in samples treated and stored for up to 72 hours, however, heterotrophic bacteria persisted and were identified after 24, 48 and 72 hours of treatment.

  2. Modelling and Display of the Ultraviolet Sky

    Science.gov (United States)

    Daniels, J.; Henry, R.; Murthy, J.; Allen, M.; McGlynn, T. A.; Scollick, K.

    1994-12-01

    A computer program is currently under development to model in 3D - one dimension of which is wavelength - all the known and major speculated sources of ultraviolet (900 A - 3100 A ) radiation over the celestial sphere. The software is being written in Fortran 77 and IDL and currently operates under IRIX (the operating system of the Silicon Graphics Iris Machine); all output models are in FITS format. Models along with display software will become available to the astronomical community. The Ultraviolet Sky Model currently includes the Zodiacal Light, Point Sources of Emission, and the Diffuse Galactic Light. The Ultraviolet Sky Model is currently displayed using SkyView: a package under development at NASA/ GSFC, which allows users to retrieve and display publically available all-sky astronomical survey data (covering many wavebands) over the Internet. We present a demonstration of the SkyView display of the Ultraviolet Model. The modelling is a five year development project: the work illustrated here represents product output at the end of year one. Future work includes enhancements to the current models and incorporation of the following models: Galactic Molecular Hydrogen Fluorescence; Galactic Highly Ionized Atomic Line Emission; Integrated Extragalactic Light; and speculated sources in the intergalactic medium such as Ionized Plasma and radiation from Non-Baryonic Particle Decay. We also present a poster which summarizes the components of the Ultraviolet Sky Model and outlines a further package that will be used to display the Ultraviolet Model. This work is supported by United States Air Force Contract F19628-93-K-0004. Dr J. Daniels is supported with a post-doctoral Fellowship from the Leverhulme Foundation, London, United Kingdom. We are also grateful for the encouragement of Dr Stephen Price (Phillips Laboratory, Hanscomb Air Force Base, MA)

  3. Drinking water disinfection by means of ultraviolet radiation. Desinfektion von Trinkwasser durch UV-Bestrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Gelzhaeuser, P; Bewig, F; Holm, K; Kryschi, R; Reich, G; Steuer, W

    1985-01-01

    The book presents all lectures held during a course at Technical Academy Esslingen, on September 10, 1985, on the subject of 'Drinking water disinfection by means of ultraviolet radiation'. The methods hitherto used for disinfection are no longer suitable because of the increasing amounts of organic pollutants found in the untreated water, and because of the necessity to make drinking water disinfection less expensive, non-polluting and thus environmentally compatible. U.V. irradiation is a method allowing technically simple and safe disinfection of the water, and also does not have any effect on the natural taste of the drinking water. The lectures presented discuss all aspects of the method, the equipment, and the performance of irradiation systems in practice.

  4. Solar ultraviolet radiation-induced DNA damage in aquatic organisms: potential environmental impact

    International Nuclear Information System (INIS)

    Haeder, Donat-P.; Sinha, Rajeshwar P.

    2005-01-01

    Continuing depletion of stratospheric ozone and subsequent increases in deleterious ultraviolet (UV) radiation at the Earth's surface have fueled the interest in its ecological consequences for aquatic ecosystems. The DNA is certainly one of the key targets for UV-induced damage in a variety of aquatic organisms. UV radiation induces two of the most abundant mutagenic and cytotoxic DNA lesions, cyclobutane pyrimidine dimers (CPDs) and pyrimidine pyrimidone photoproducts (6-4PPs) and their Dewar valence isomers. However, aquatic organisms have developed a number of repair and tolerance mechanisms to counteract the damaging effects of UV on DNA. Photoreactivation with the help of the enzyme photolyase is one of the most important and frequently occurring repair mechanisms in a variety of organisms. Excision repair, which can be distinguished into base excision repair (BER) and nucleotide excision repair (NER), also play an important role in DNA repair in several organisms with the help of a number of glycosylases and polymerases, respectively. In addition, mechanisms such as mutagenic repair or dimer bypass, recombinational repair, cell-cycle checkpoints, apoptosis and certain alternative repair pathways are also operative in various organisms. This review deals with the UV-induced DNA damage and repair in a number of aquatic organisms as well as methods of detecting DNA damage

  5. Potential effects of ultraviolet radiation reduction on tundra nitrous oxide and methane fluxes in maritime Antarctica.

    Science.gov (United States)

    Bao, Tao; Zhu, Renbin; Wang, Pei; Ye, Wenjuan; Ma, Dawei; Xu, Hua

    2018-02-27

    Stratospheric ozone has begun to recover in Antarctica since the implementation of the Montreal Protocol. However, the effects of ultraviolet (UV) radiation on tundra greenhouse gas fluxes are rarely reported for Polar Regions. In the present study, tundra N 2 O and CH 4 fluxes were measured under the simulated reduction of UV radiation in maritime Antarctica over the last three-year summers. Significantly enhanced N 2 O and CH 4 emissions occurred at tundra sites under the simulated reduction of UV radiation. Compared with the ambient normal UV level, a 20% reduction in UV radiation increased tundra emissions by an average of 8 μg N 2 O m -2 h -1 and 93 μg CH 4 m -2 h -1 , whereas a 50% reduction in UV radiation increased their emissions by an average of 17 μg N 2 O m -2 h -1 and 128 μg CH 4 m -2 h -1 . No statistically significant correlation (P > 0.05) was found between N 2 O and CH 4 fluxes and soil temperature, soil moisture, total carbon, total nitrogen, NO 3 - -N and NH 4 + -N contents. Our results confirmed that UV radiation intensity is an important factor affecting tundra N 2 O and CH 4 fluxes in maritime Antarctica. Exclusion of the effects of reduced UV radiation might underestimate their budgets in Polar Regions with the recovery of stratospheric ozone.

  6. Abscisic acid and ethylene in mutants of Arabidopsis thaliana differing in their resistance to ultraviolet (UV-B) radiation stress

    International Nuclear Information System (INIS)

    Rakitina, T.Ya.; Vlasov, P.V.; Jalilova, F.Kh.; Kefeli, V.I.

    1994-01-01

    The effects of ultraviolet irradiation (between 280 and 320 nm) on plant survival, ethylene evolution, and abscisic acid (ABA) content were studied in Arabidopsis thaliana (L.) Heunh. plants. Three genetic lines of Arabidopsis differing in their resistance to ultraviolet (UV-B) radiation stress were used. UV-B irradiation had detrimental effects on plant survival, enhanced ethylene evolution, and increased ABA content in the plants of all three lines. The higher ultraviolet dose was absorbed, the less was the number of surviving plants and the higher were the levels of both phytohormones. The maximum ethylene evolution occurred during the initial two to four hours after irradiation, but the ABA content peaked only after 24 h. The most resistant line showed the highest ABA content and the fastest ethylene evolution, whereas, in the susceptible line, both indices were the lowest. After UV-B treatment, the ABA-deficient Arabidopsis mutant evolved four to six times more ethylene than the plants with normal ABA content. Stress ethylene production evidently did not depend on the level of endogenous ABA as the kinetics of ethylene evolution was similar in the ABA-deficient mutant and in other studied Arabidopsis lines

  7. Antioxidant activity stimulated by ultraviolet radiation in the nervous system of a crustacean

    International Nuclear Information System (INIS)

    Hollmann, Gabriela; Ferreira, Gabrielle de Jesus; Geihs, Márcio Alberto; Vargas, Marcelo Alves

    2015-01-01

    Highlights: • Ultraviolet (UV) radiation produces biological damage, principally oxidative stress. • We analyzed oxidative stress in the central nervous system (CNS) of a crab. • The damage was evaluated using biochemical tests and immunohistochemistry. • We verified the occurrence of apoptosis in the brain of the UV-exposed crabs. • Environmental doses of UV can cause oxidative damage to CNS, including apoptosis. - Abstract: Ultraviolet (UV) radiation can produce biological damage, principally oxidative stress, by increasing the production of reactive oxygen species (ROS). This study evaluated biochemical impairments related to the oxidative stress induced by UVA, UVB and UVA + UVB (solar simulator-SIM) in environmental doses, during five consecutive days of exposure, in the brain and eyestalk of the crab Ucides cordatus. We evaluated these regions by sampling on the 1st, 3rd and 5th days of UV exposure for lipid peroxidation (LPO), antioxidant capacity against the peroxyl radical (ACAP), and the activities of catalase (CAT), glutathione peroxidase (GPX) and glutathione-S-transferase (GST). Immunohistochemical and immunoblotting assays were performed for anti-activated-caspase 3 in the brains. After the first day of exposure, LPO increased in the eyestalks and brains of the UV-exposed animals; ACAP, and CAT, GPX and GST activities also increased in the brains. On the third day, the LPO values in the eyestalk remained high in the UV-exposed groups, while ACAP decreased in the brain and eyestalk and CAT activity remained high in all irradiated groups in both regions. On the fifth day, LPO decreased in the eyestalk and brain of the UV-exposed groups. These results may have been a consequence of the antioxidant defense system (ADS) activity, since CAT activity was high in both regions, ACAP was high in the eyestalks of the SIM group, and GPX activity remained high in the eyestalks of the UVA and UVB groups. Immunohistochemical assays and immunoblotting

  8. Antioxidant activity stimulated by ultraviolet radiation in the nervous system of a crustacean

    Energy Technology Data Exchange (ETDEWEB)

    Hollmann, Gabriela, E-mail: gabrielahollmann@biof.ufrj.br [Programa de Pós Graduação em Ciências Biológicas-Fisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro-UFRJ, Rio de Janeiro, RJ 21941-590 (Brazil); Ferreira, Gabrielle de Jesus, E-mail: gabi_ferreiira@hotmail.com [Programa de Pós Graduação em Ciências Biológicas-Fisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro-UFRJ, Rio de Janeiro, RJ 21941-590 (Brazil); Geihs, Márcio Alberto, E-mail: geihs@hotmail.com [Programa de Pós Graduação em Ciências Fisiológicas-Fisiologia Animal Comparada. Instituto de Ciências Biológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS 96201-900 (Brazil); Vargas, Marcelo Alves, E-mail: biovargas@gmail.com [Programa de Pós Graduação em Ciências Fisiológicas-Fisiologia Animal Comparada. Instituto de Ciências Biológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS 96201-900 (Brazil); and others

    2015-03-15

    Highlights: • Ultraviolet (UV) radiation produces biological damage, principally oxidative stress. • We analyzed oxidative stress in the central nervous system (CNS) of a crab. • The damage was evaluated using biochemical tests and immunohistochemistry. • We verified the occurrence of apoptosis in the brain of the UV-exposed crabs. • Environmental doses of UV can cause oxidative damage to CNS, including apoptosis. - Abstract: Ultraviolet (UV) radiation can produce biological damage, principally oxidative stress, by increasing the production of reactive oxygen species (ROS). This study evaluated biochemical impairments related to the oxidative stress induced by UVA, UVB and UVA + UVB (solar simulator-SIM) in environmental doses, during five consecutive days of exposure, in the brain and eyestalk of the crab Ucides cordatus. We evaluated these regions by sampling on the 1st, 3rd and 5th days of UV exposure for lipid peroxidation (LPO), antioxidant capacity against the peroxyl radical (ACAP), and the activities of catalase (CAT), glutathione peroxidase (GPX) and glutathione-S-transferase (GST). Immunohistochemical and immunoblotting assays were performed for anti-activated-caspase 3 in the brains. After the first day of exposure, LPO increased in the eyestalks and brains of the UV-exposed animals; ACAP, and CAT, GPX and GST activities also increased in the brains. On the third day, the LPO values in the eyestalk remained high in the UV-exposed groups, while ACAP decreased in the brain and eyestalk and CAT activity remained high in all irradiated groups in both regions. On the fifth day, LPO decreased in the eyestalk and brain of the UV-exposed groups. These results may have been a consequence of the antioxidant defense system (ADS) activity, since CAT activity was high in both regions, ACAP was high in the eyestalks of the SIM group, and GPX activity remained high in the eyestalks of the UVA and UVB groups. Immunohistochemical assays and immunoblotting

  9. Reduction in cab and psb A RNA transcripts in response to supplementary ultraviolet-B radiation.

    Science.gov (United States)

    Jordan, B R; Chow, W S; Strid, A; Anderson, J M

    1991-06-17

    The cab and psb A RNA transcript levels have been determined in Pisum sativum leaves exposed to supplementary ultraviolet-B radiation. The nuclear-encoded cab transcripts are reduced to low levels after only 4 h of UV-B treatment and are undetectable after 3 days exposure. In contrast, the chloroplast-encoded psb A transcript levels, although reduced, are present for at least 3 days. After short periods of UV-B exposure (4 h or 8 h), followed by recovery under control conditions, cab RNA transcript levels had not recovered after 1 day, but were re-established to ca. 60% of control levels after 2 more days. Increased irradiance during exposure to UV-B reduced the effect upon cab transcripts, although the decrease was still substantial. These results indicate rapid changes in the cellular regulation of gene expression in response to supplementary UV-B and suggest increased UV-B radiation may have profound consequences for future productivity of sensitive crop species.

  10. Large-solid-angle illuminators for extreme ultraviolet lithography with laser plasmas

    International Nuclear Information System (INIS)

    Kubiak, G.D.; Tichenor, D.A.; Sweatt, W.C.; Chow, W.W.

    1995-06-01

    Laser Plasma Sources (LPSS) of extreme ultraviolet radiation are an attractive alternative to synchrotron radiation sources for extreme ultraviolet lithography (EUVL) due to their modularity, brightness, and modest size and cost. To fully exploit the extreme ultraviolet power emitted by such sources, it is necessary to capture the largest possible fraction of the source emission half-sphere while simultaneously optimizing the illumination stationarity and uniformity on the object mask. In this LDRD project, laser plasma source illumination systems for EUVL have been designed and then theoretically and experimentally characterized. Ellipsoidal condensers have been found to be simple yet extremely efficient condensers for small-field EUVL imaging systems. The effects of aberrations in such condensers on extreme ultraviolet (EUV) imaging have been studied with physical optics modeling. Lastly, the design of an efficient large-solid-angle condenser has been completed. It collects 50% of the available laser plasma source power at 14 nm and delivers it properly to the object mask in a wide-arc-field camera

  11. Leaf hairs of Olea europaea protect underlying tissues against ultraviolet-B radiation damage

    International Nuclear Information System (INIS)

    Karabourniotis, G.; Kyparissis, A.; Manetas, Y.

    1993-01-01

    The photochemical efficiency of photosystem II, as measured by chlorophyll fluorescence induction, was not affected in de-haired olive leaves kept in the dark or intact leaves irradiated with a moderate (3.75 W m-2) ultraviolet-B (UV-B) intensity. In de-haired, UV-B-irradiated leaves, however, the ratio of variable to maximum (F(v)/F(m)) chlorophyll fluorescence declined significantly and irreversibly. Reduction in F(v)/V(m) was associated with an increase in instantaneous and a decrease in maximum (F(m)) fluorescence, indicating perturbation by the UV-B exposure of more than one photosynthetic site. Extensive epidermal browning in de-haired, UV-B irradiated leaves was also observed, indicating possible damage to cell membranes. The results strengthen the hypothesis that leaf hairs protect the underlying tissues against UV-B radiation damage

  12. Acute skin lesions following psoralen plus ultraviolet A radiation investigated by optical coherence tomography

    International Nuclear Information System (INIS)

    Liu, Z M; Zhong, H Q; Zhai, J; Wang, C X; Xiong, H L; Guo, Z Y

    2013-01-01

    Psoralen plus ultraviolet A radiation (PUVA) therapy is a very important clinical treatment of skin diseases such as vitiligo and psoriasis, but associated with an increased risk of skin photodamage, especially photoaging. In this work, optical coherence tomography (OCT), a novel non-invasive imaging technology, was introduced to investigate in vivo the photodamage induced by PUVA qualitatively and quantitatively. Balb/c mouse dorsal skin was treated with 8-methoxypsoralen (8-MOP), and then exposed to UVA radiation. OCT images of the tissues were obtained by an OCT system with a 1310 nm central wavelength. Skin thickness and the attenuation coefficient were extracted from the OCT images to analyze the degree of injury to mouse skin. The results demonstrated that PUVA-treated skin showed an increase in skin thickness, and a reduction of attenuation coefficient in the OCT signal compared with the control groups. The data also showed good correlation with the results observed in histological sections using hematoxylin and eosin staining. In conclusion, OCT is a promising tool for photobiological studies aimed at assessing the effect of PUVA therapy in vivo. (paper)

  13. Ultraviolet germicidal efficacy as a function of pulsed radiation parameters studied by spore film dosimetry.

    Science.gov (United States)

    Bauer, Stefan; Holtschmidt, Hans; Ott, Günter

    2018-01-01

    Disinfection by pulsed ultraviolet (UV) radiation is a commonly used method, e.g. in industry or medicine and can be carried out either with lasers or broadband UV radiation sources. Detrimental effects to biological materials depending on parameters such as pulse duration τ or pulse repetition frequency f p are well-understood for pulsed coherent UV radiation, however, relatively little is known for its incoherent variant. Therefore, within this work, it is the first time that disinfection rates of pulsed and continuous (cw) incoherent UV radiation studied by means of spore film dosimetry are presented, compared with each other, and in a second step further investigated regarding two pulse parameters. After analyzing the dynamic range of the Bacillus subtilis spore films with variable cw radiant exposures H=5-100Jm -2 a validation of the Bunsen-Roscoe law revealed its restricted applicability and a 28% enhanced detrimental effect of pulsed compared to cw incoherent UV radiation. A radiant exposure H=50Jm -2 and an irradiance E=0.5Wm -2 were found to be suitable parameters for an analysis of the disinfection rate as a function of τ=0.5-10ms and f p =25-500Hz unveiling that shorter pulses and lower frequencies inactivate more spores. Finally, the number of applied pulses as well as the experiment time were considered with regard to spore film disinfection. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Internet advertising of artificial tanning in Australia.

    Science.gov (United States)

    Team, Victoria; Markovic, Milica

    2006-08-01

    Artificial tanning, defined as deliberate exposure to ultraviolet rays produced by artificial tanning devices, is a new and emerging public health issue in Australia and globally. Epidemiological research suggests that artificial tanning may contribute to the incidence of melanoma, nonmelanoma skin cancer as well as other health problems. Given that Australia has a high incidence of skin cancer, we have undertaken a study to explore how artificial tanning has been promoted to its users. The aim was to analyze the completeness and accuracy of information about artificial tanning. A content analysis of web sites of tanning salons and distributors of tanning equipment in Australia was conducted. A total of 22 web sites were analyzed. None of the solarium operators or distributors of equipment provided full information about the risks of artificial tanning. Fifty-nine percent of web advertisements had no information and 41% provided only partial information regarding the risks of artificial tanning. Pictures with the image of bronze-tanned bodies, predominantly women, were used by all web advertisers. In light of the success of sun-safety campaigns in Australia, the findings of future epidemiological research on the prevalence of artificial tanning and sociological and anthropological research on why people utilize artificial tanning should be a basis for developing effective targeted health promotion on the elimination of artificial tanning in the country.

  15. Ultraviolet radiation and sugar-induced chlorosis in detached leaves of Elodea densa

    International Nuclear Information System (INIS)

    Witztum, A.

    1978-01-01

    When portions of the leaves of Elodea densa were exposed to shortwave ultraviolet (uv) radiation for 20 to 30 s at 2,000 μW/cm 2 , the chloroplasts of the irradiated tissue did not change in volume and remained green, but chloroplasts of the adjacent nonirradiated tissue decreased in volume, became yellow, and were transformed into yellow-orange chromoplasts during a 5 to 7-day period. Similar changes can be induced in nonirradiated leaves by incubating them in glucose or sucrose solutions. Chloroplasts in uv-exposed leaf tissue, however, remained green and did not decrease in volume even when incubated in glucose or sucrose solutions. Cycloheximide (10 ppM) prevented uv-induced yellowing of adjacent nonirradiated leaf tissue as well as glucose- and sucrose-induced yellowing in nonirradiated leaves. Similarly, cycloheximide prevented sugar-induced anthocyanin synthesis in the light. Cytoplasmic streaming continued in all treatments

  16. Assessment of environmental impact of ultraviolet radiation or electron beam cured print inks on plastic packaging materials

    International Nuclear Information System (INIS)

    Bardi, Marcelo Augusto Goncalves

    2014-01-01

    The high level of pollution generated by the inadequate disposal of polymeric materials has motivated the search for environmentally friendly systems and techniques such as the application of biodegradable polymers and the replacement of the solvent-based paint systems by those with high solids content, based water or cured by radiation, practically free of volatile organic compounds. However, the cured polymer coatings are neither soluble nor molten, increasing the complexity of the reprocessing, recycling and degradation. Thus, this work aimed to develop print inks modified with pro-degrading agents, cured by ultraviolet radiation or electron beam, for printing or decoration in plastic packaging products of short lifetime, which are biodegradable or not. Six coatings (varnish and inks in five colors: yellow, blue, white, black and red), three pro-degrading agents (cobalt stearate, cerium stearate and manganese stearate), five polymeric substrates (Ecobras®, low density polyethylene and its respective modifications with pro-degrading agents). The coatings were applied to the substrates and cured by ultraviolet radiation or electron beam, resulting in 180 samples. These materials were then exposed to accelerated aging chamber, type 'QUV', and composting in natural environment. In order to assess the effects of the polymer coatings on the degradation process of the specimens, only the yellow and black samples were exposed to a controlled composting environment via respirometry, reducing to 16 the number of samples. The organic compound generated by the biodegradation process was analyzed by the ecotoxicity tests. It was observed that the coating layer acted as a barrier that inhibits degradation of the plastic when exposed to weathering. The addition of pro-degrading agents promoted acceleration in the degradation process, promoting the migration of the metal ion to the medium without affecting the final quality of the organic compost. (author)

  17. Ultraviolet-B radiation screening effectiveness of reproductive organs in Hesperis matronalis

    International Nuclear Information System (INIS)

    Day, T.A.; Demchik, S.M.

    1996-01-01

    We assessed the ultraviolet-B radiation (UV-B; 280–320 nm) screening effectiveness of reproductive organs (sepals, petals and ovaries) of naturally growing Hesperis matronalis L. (dame's rocket, Brassicaceae) plants by measuring surface reflectance, epidermal and whole-organ transmittance and depth of penetration of 300 nm UV-B. We also measured the concentration of UV-B absorbing compounds in these organs (as well as pollen) to provide explanations for differences in their UV-B screening abilities. Surface reflectance of UV-B was less than 4% and was similar in sepals, petals and sides of ovaries. Ultraviolet-B penetrated (assessed as 1% of incident) an average of 275 μm and 384 μm into sepals and petals, respectively. In contrast, UV-B penetrated only 140 μm into the side of ovaries (measured mid-way between the base of the ovary and the stigma) and 108 μm into the stigma toward the ovary. Thus, UV-B was attenuated well before reaching the ovules which were over 500 μm within the sides of the ovaries and over 4000 μm below the stigma surface. This relatively effective attenuation of UV-B by the ovary was probably due to high concentrations of UV-B absorbing compounds which averaged more than twice those found in sepals and petals on a silhouette-area basis. Although their small size prevented us from measuring UV-B penetration, pollen grains also contained very high concentrations of UV-B absorbing compounds, averaging about 20 times those of sepals and petals on a silhouette-area basis. While this suggests that pollen of H. matronalis is effective at screening UV-B, the reported UV-B sensitivity of pollen suggests these high concentrations of absorbing compounds may not be completely effective in protecting the male gametes. (author)

  18. Photokeratitis induced by ultraviolet radiation in travelers: A major health problem

    Directory of Open Access Journals (Sweden)

    M Izadi

    2018-01-01

    Full Text Available Ultraviolet (UV irradiation is one of the several environmental hazards that may cause inflammatory reactions in ocular tissues, especially the cornea. One of the important factors that affect how much ultraviolet radiation (UVR humans are exposed to is travel. Hence, traveling is considered to include a more acute UVR effect, and ophthalmologists frequently evaluate and manage the ocular manifestations of UV irradiation, including UV-induced keratitis. The purpose of this paper is to provide an evidence-based analysis of the clinical effect of UVR in ocular tissues. An extensive review of English literature was performed to gather all available articles from the National Library of Medicine PubMed database of the National Institute of Health, the Ovid MEDLINE database, Scopus, and ScienceDirect that had studied the effect of UVR on the eye and its complications, between January 1970 and June 2014. The results show that UVR at 300 nm causes apoptosis in all three layers of the cornea and induces keratitis. Apoptosis in all layers of the cornea occurs 5 h after exposure. The effect of UVR intensity on the eye can be linked to numerous factors, including solar elevation, time of day, season, hemisphere, clouds and haze, atmospheric scattering, atmospheric ozone, latitude, altitude, longitudinal changes, climate, ground reflection, and geographic directions. The most important factor affecting UVR reaching the earth's surface is solar elevation. Currently, people do not have great concern over eye protection. The methods of protection against UVR include avoiding direct sunlight exposure, using UVR-blocking eyewear (sunglasses or contact lenses, and wearing hats. Hence, by identifying UVR intensity factors, eye protection factors, and public education, especially in travelers, methods for safe traveling can be identified.

  19. Photokeratitis induced by ultraviolet radiation in travelers: A major health problem.

    Science.gov (United States)

    Izadi, M; Jonaidi-Jafari, N; Pourazizi, M; Alemzadeh-Ansari, M H; Hoseinpourfard, M J

    2018-01-01

    Ultraviolet (UV) irradiation is one of the several environmental hazards that may cause inflammatory reactions in ocular tissues, especially the cornea. One of the important factors that affect how much ultraviolet radiation (UVR) humans are exposed to is travel. Hence, traveling is considered to include a more acute UVR effect, and ophthalmologists frequently evaluate and manage the ocular manifestations of UV irradiation, including UV-induced keratitis. The purpose of this paper is to provide an evidence-based analysis of the clinical effect of UVR in ocular tissues. An extensive review of English literature was performed to gather all available articles from the National Library of Medicine PubMed database of the National Institute of Health, the Ovid MEDLINE database, Scopus, and ScienceDirect that had studied the effect of UVR on the eye and its complications, between January 1970 and June 2014. The results show that UVR at 300 nm causes apoptosis in all three layers of the cornea and induces keratitis. Apoptosis in all layers of the cornea occurs 5 h after exposure. The effect of UVR intensity on the eye can be linked to numerous factors, including solar elevation, time of day, season, hemisphere, clouds and haze, atmospheric scattering, atmospheric ozone, latitude, altitude, longitudinal changes, climate, ground reflection, and geographic directions. The most important factor affecting UVR reaching the earth's surface is solar elevation. Currently, people do not have great concern over eye protection. The methods of protection against UVR include avoiding direct sunlight exposure, using UVR-blocking eyewear (sunglasses or contact lenses), and wearing hats. Hence, by identifying UVR intensity factors, eye protection factors, and public education, especially in travelers, methods for safe traveling can be identified.

  20. Spectral properties of plant leaves pertaining to urban landscape design of broad-spectrum solar ultraviolet radiation reduction

    Science.gov (United States)

    Yoshimura, Haruka; Zhu, Hui; Wu, Yunying; Ma, Ruijun

    2010-03-01

    Human exposure to harmful ultraviolet (UV) radiation has important public health implications. Actual human exposure to solar UV radiation depends on ambient UV irradiance, and the latter is influenced by ground reflection. In urban areas with higher reflectivity, UV exposure occurs routinely. To discover the solar UV radiation regulation mechanism of vegetation, the spectral reflectance and transmittance of plant leaves were measured with a spectrophotometer. Typically, higher plants have low leaf reflectance (around 5%) and essentially zero transmittance throughout the UV region regardless of plant species and seasonal change. Accordingly, incident UV radiation decreases to 5% by being reflected and is reduced to zero by passing through a leaf. Therefore, stratified structures of vegetation are working as another terminator of UV rays, protecting whole terrestrial ecosystems, while vegetation at waterfronts contributes to protect aquatic ecosystems. It is possible to protect the human population from harmful UV radiation by urban landscape design of tree shade and the botanical environment. Even thin but uniformly distributed canopy is effective in attenuating UV radiation. To intercept diffuse radiation, UV screening by vertical structures such as hedges should be considered. Reflectivity of vegetation is around 2%, as foliage surfaces reduce incident UV radiation via reflection, while also eliminating it by transmittance. Accordingly, vegetation reduces incident UV radiation to around 2% by reflection. Vegetation influence on ambient UV radiation is broad-spectrum throughout the UV region. Only trees provide cool UV protective shade. Urban landscapes aimed at abating urban heat islands integrated with a reduction of human UV over-exposure would contribute to mitigation of climate change.

  1. INFLUENCE OF ULTRAVIOLET RADIATION ON MICROBIOLOGICAL AND SENSORY CHARACTERISTICS OF CERTAIN CATEGORIES OF VEGETABLES PRODUCTS AND THEIR PRESERVATION LIFE

    Directory of Open Access Journals (Sweden)

    Danilevici Constantin

    2010-01-01

    Full Text Available Research paper aims to highlight the scientific correlation between the influence of ultraviolet radiation (UV onsensory and microbiological characteristics of plant products in the category of leaves (lettuce and other types ofvegetables or fruit (bananas and their preservation’s duration, through their UV irradiation under certain conditions.The literature indicates a germicidal action of UV (medium UV on micro-organisms, optimal for λ = 254 nm. Theeffectiveness of radiation is influenced by duration of irradiation, the distance between the radiation source and thesample product and radiant power source.The action of microbial cell inactivation or destruction can be explained by changes in cellular structure andpermeability with changes at the level of mitochondria and the genetic material as a result of photochemical effects ofUV products. Research highlights the preservative effect of UV radiation (with λ = 254 nm and also their influence onsensory properties and positive to negative for leafy vegetables and fruits (bananas in our case.

  2. Ultraviolet and Infrared Correlation Studies in Orion

    Directory of Open Access Journals (Sweden)

    Bose Lakshmi S.

    2015-09-01

    Full Text Available We have studied the variation of diffuse ultraviolet (UV radiation in the northern part of the Orion constellation using a set of eight areas of the GALEX All-Sky Imaging Survey in the far and near UV. Different components of diffuse UV radiation, like dust scattered emission and H2 fluorescence, were quantified and separated after removing the point sources and the foreground emission in each of the fields. Then the dependence of the individual UV components on the infrared 100 μm dust emission was studied. We did not find any positive correlation between the diffuse-UV and IR-100 micron intensities, probably due to the high optical depth of the region or the entire dust column not contributing to the diffuse UV radiation. However, in the far UV we noticed the presence of an excess emission in addition to the dust scattered radiation, which is clearly absent in the near UV. This excess emission, identified as the H2 fluorescence, is produced by the Trapezium stars in the surrounding molecular clouds. We also compare our results with those of previous studies in the region, based on Far Ultraviolet Spectroscopic Explorer (FUSE observations.

  3. Quantification of ultraviolet radiation-induced DNA damage in the urine of Swedish adults and children following exposure to sunlight

    OpenAIRE

    Liljendahl, Tove Sandberg; Kotova, Natalia; Segerbäck, Dan

    2012-01-01

    DNA damage following exposure to ultraviolet radiation (UVR) is important in skin cancer development. The predominant photoproduct, cyclobutane thymine dimer (T=T), is repaired and excreted in the urine, where it provides a biomarker of exposure. To quantify urinary T=T levels after recreational sunlight exposure in adults and children. Average UVR doses were measured with personal dosimeters. Urinary T=T was analysed with (32)P-postlabelling. ResuLTS: Background levels of T=T increased...

  4. Heme oxygenase up-regulation under ultraviolet-B radiation is not epigenetically restricted and involves specific stress-related transcriptions factors

    Directory of Open Access Journals (Sweden)

    Diego Santa-Cruz

    2017-08-01

    Full Text Available Heme oxygenase-1 (HO-1 plays a protective role against oxidative stress in plants. The mechanisms regulating its expression, however, remain unclear. Here we studied the methylation state of a GC rich HO-1 promoter region and the expression of several stress-related transcription factors (TFs in soybean plants subjected to ultraviolet-B (UV-B radiation. Genomic DNA and total RNA were isolated from leaves of plants irradiated with 7.5 and 15 kJ m-2 UV-B. A 304 bp HO-1 promoter region was amplified by PCR from sodium bisulfite-treated DNA, cloned into pGEMT plasmid vector and evaluated by DNA sequencing. Bisulfite sequencing analysis showed similar HO-1 promoter methylation levels in control and UV-B-treated plants (C: 3.4±1.3%; 7.5: 2.6±0.5%; 15: 3.1±1.1%. Interestingly, HO-1 promoter was strongly unmethylated in control plants. Quantitative RT-PCR analysis of TFs showed that GmMYB177, GmMYBJ6, GmWRKY21, GmNAC11, GmNAC20 and GmGT2A but not GmWRK13 and GmDREB were induced by UV-B radiation. The expression of several TFs was also enhanced by hemin, a potent and specific HO inducer, inferring that they may mediate HO-1 up-regulation. These results suggest that soybean HO-1 gene expression is not epigenetically regulated. Moreover, the low level of HO-1 promoter methylation suggests that this antioxidant enzyme can rapidly respond to environmental stress. Finally, this study has identified some stress-related TFs involved in HO-1 up-regulation under UV-B radiation. Keywords: Heme oxygenase, DNA methylation, Transcription factors, Ultraviolet-B radiation, Glycine max

  5. Altmetric: 165More detailArticle | OPENClimate change-induced increases in precipitation are reducing the potential for solar ultraviolet radiation to inactivate pathogens in surface waters

    Science.gov (United States)

    Climate change is accelerating the release of dissolved organic matter (DOM) to inland and coastal waters through increases in precipitation, thawing of permafrost, and changes in vegetation. Our modeling approach suggests that the selective absorption of ultraviolet radiation (U...

  6. Disinfection ultraviolet radiation bulk food products

    OpenAIRE

    Семенов, А. А.

    2014-01-01

    В работе представлены результаты обеззараживания сыпучих пищевых продуктов ультрафиолетовым излучением. Предложена технология бактерицидного обеззараживания сыпучих продуктов с размером частиц до 50 мкм. Проведены необходимые расчеты, связанные с дозой облучения, с временем пребывания частиц в зоне облучения и необходимой дозой инактивации в зависимости от вида бактерий. Considered the results of bulk food products disinfection by ultraviolet radiation. The technology bactericidal disinfec...

  7. Tl response of KMgF{sub 3}: Lu + PTFE at ultraviolet radiation; Respuesta Tl de KMgF{sub 3}: Lu + PTFE a radiacion ultravioleta

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P R [Instituto Nacional de Investigaciones Nucleares, A.P. 18 -1027, 11801 Mexico D.F. (Mexico); Alarcon, N G [Facultad de Quimica, Universidad Autonoma del Estado de Mexico. Paseo Tollocan, Esq. con Jesus Carranza, 50180 Toluca, Estado de Mexico (Mexico); Furetta, C; Azorin, J [Universidad Autonoma Metropolitana- Iztapalapa, San Rafael Atlixco 186, 09340 Mexico. D.F. (Mexico)

    2003-07-01

    Ionizing radiation has different types of interaction with a crystalline solid. However, only few effects are interesting to optimize some thermoluminescent (Tl) properties of certain Tl materials. This paper presents results obtained by irradiating KMgF{sub 3}: Lu + Ptfe Tl dosimeters with ultraviolet (UV) radiation previously exposed to gamma radiation. These results showed that those dosimeters not exposed previously to gamma radiation did not presented any Tl signal. Meanwhile, those previously submitted to gamma irradiation showed that their sensitivity was increased as the gamma dose increased. The glow curve of sensitized KMgF{sub 3}: Lu + Ptfe exposed to UV radiation, presented the dosimetric pea at 212 C. This makes this material to be promissory for measuring UV radiation. (Author)

  8. Ultraviolet and infrared spectral analysis of poly(vinyl)butyral films: correlation and possible application for high-dose radiation dosimetry

    International Nuclear Information System (INIS)

    Ebraheem, S.; El-Kelany, M.; Beshir, W.; Abdel-Fattah, A.A.

    1999-01-01

    A detailed study was performed to develop the dosimetric characteristics of poly(vinyl)butyral film (PVB), to be used as a film dosimeter for high-dose gamma radiation dosimetry. The useful dose range of this polymeric film extends up to 350 kGy. Correlations were established between the absorbed dose of gamma radiation and the radiation-induced changes in PVB measured by means of ultraviolet (UV) and Fourier Transform Infrared (FTIR) spectrophotometry. The results showed a significant dependence of the response on the selected readout tool of measurements whether FTIR (at 1738 and 3400 cm -1 ) or UV (at 275 and 230 nm), as well as on the quantity used for calculation. The effect of relative humidity during irradiation on dosimeter performance as well as the post-irradiation stability at different storage conditions are also discussed. (author)

  9. Monitoring ultraviolet (UV) radiation inactivation of Cronobacter sakazakii in dry infant formula using Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Liu, Qian; Lu, Xiaonan; Swanson, Barry G; Rasco, Barbara A; Kang, Dong-Hyun

    2012-01-01

    Cronobacter sakazakii is an opportunistic pathogen associated with dry infant formula presenting a high risk to low birth weight neonates. The inactivation of C. sakazakii in dry infant formula by ultraviolet (UV) radiation alone and combined with hot water treatment at temperatures of 55, 60, and 65 °C were applied in this study. UV radiation with doses in a range from 12.1 ± 0.30 kJ/m² to 72.8 ± 1.83 kJ/m² at room temperature demonstrated significant inactivation of C. sakazakii in dry infant formula (P radiation combining 60 °C hot water treatment increased inactivation of C. sakazakii cells significantly (P radiation on C. sakazakii inactivation kinetics (D value) were not observed in infant formula reconstituted in 55 and 65 °C water (P > 0.05). The inactivation mechanism was investigated using vibrational spectroscopy. Infrared spectroscopy detected significant stretching mode changes of macromolecules on the basis of spectral features, such as DNA, proteins, and lipids. Minor changes on cell membrane composition of C. sakazakii under UV radiation could be accurately and correctly monitored by infrared spectroscopy coupled with 2nd derivative transformation and principal component analysis. © 2011 Institute of Food Technologists®

  10. Lighting considerations in controlled environments for nonphotosynthetic plant responses to blue and ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, M.M.; Flint, S.D. [Utah State Univ., Logan, UT (United States)

    1994-12-31

    This essay will consider both physical and photobiological aspects of controlled environment lighting in the spectral region beginning in the blue and taken to the normal limit of the solar spectrum in the ultraviolet. The primary emphasis is directed to questions of plant response to sunlight. Measurement and computations used in radiation dosimetry in this part of the spectrum are also briefly treated. Because of interest in the ozone depletion problem, there has been some activity in plant UV-B research and there are several recent reviews available. Some aspects of growth chamber lighting as it relates to UV-B research were covered earlier. Apart from work related to the blue/UV-A receptor, less attention has been given to UV-A responses.

  11. Communication and Public Information in Development and Maintenance of Radiation Safety

    International Nuclear Information System (INIS)

    Huurto, L.

    2003-01-01

    The natural source of Non-Ionizing radiation (NIR) in our environment is the sun. Artificial NIR is widely used in medical and industrial applications and also in households. The most important medical NIR applications are phototherapy, surgical lasers and magnetic resonance imaging. In industry NIR is applied in radio frequency heaters and laser printing. NIR has applications even in entertainment and cosmetics: High power lasers are used in light shows and sun beds emit artificial ultraviolet radiation (UVR) for tanning. From the safety point of view the field is indeed very wide from harmless and common items to devices which can cause acute health hazards. The use of non-ionizing radiation needs neither any safety licence nor other kind of authorisation. The users of NIR devices varies from professionals in health care or lighting technology to those who only use them as a sideline in their main work like beauticians. Also laypersons use various NIR devices like microwave ovens, laser pointers and mobile phones. Many NIR devices are used in applications where the user does not have the knowledge to understand the health risks associated with the device. Thus the only way is to educate the users by communication and public information. (orig.)

  12. Flame detector operable in presence of proton radiation

    Science.gov (United States)

    Walker, D. J.; Turnage, J. E.; Linford, R. M. F.; Cornish, S. D. (Inventor)

    1974-01-01

    A detector of ultraviolet radiation for operation in a space vehicle which orbits through high intensity radiation areas is described. Two identical ultraviolet sensor tubes are mounted within a shield which limits to acceptable levels the amount of proton radiation reaching the sensor tubes. The shield has an opening which permits ultraviolet radiation to reach one of the sensing tubes. The shield keeps ultraviolet radiation from reaching the other sensor tube, designated the reference tube. The circuitry of the detector subtracts the output of the reference tube from the output of the sensing tube, and any portion of the output of the sensing tube which is due to proton radiation is offset by the output of the reference tube. A delay circuit in the detector prevents false alarms by keeping statistical variations in the proton radiation sensed by the two sensor tubes from developing an output signal.

  13. Ultraviolet-radiation-induced inflammation promotes angiotropism and metastasis in melanoma

    Science.gov (United States)

    Bald, Tobias; Quast, Thomas; Landsberg, Jennifer; Rogava, Meri; Glodde, Nicole; Lopez-Ramos, Dorys; Kohlmeyer, Judith; Riesenberg, Stefanie; van den Boorn-Konijnenberg, Debby; Hömig-Hölzel, Cornelia; Reuten, Raphael; Schadow, Benjamin; Weighardt, Heike; Wenzel, Daniela; Helfrich, Iris; Schadendorf, Dirk; Bloch, Wilhelm; Bianchi, Marco E.; Lugassy, Claire; Barnhill, Raymond L.; Koch, Manuel; Fleischmann, Bernd K.; Förster, Irmgard; Kastenmüller, Wolfgang; Kolanus, Waldemar; Hölzel, Michael; Gaffal, Evelyn; Tüting, Thomas

    2014-03-01

    Intermittent intense ultraviolet (UV) exposure represents an important aetiological factor in the development of malignant melanoma. The ability of UV radiation to cause tumour-initiating DNA mutations in melanocytes is now firmly established, but how the microenvironmental effects of UV radiation influence melanoma pathogenesis is not fully understood. Here we report that repetitive UV exposure of primary cutaneous melanomas in a genetically engineered mouse model promotes metastatic progression, independent of its tumour-initiating effects. UV irradiation enhanced the expansion of tumour cells along abluminal blood vessel surfaces and increased the number of lung metastases. This effect depended on the recruitment and activation of neutrophils, initiated by the release of high mobility group box 1 (HMGB1) from UV-damaged epidermal keratinocytes and driven by Toll-like receptor 4 (TLR4). The UV-induced neutrophilic inflammatory response stimulated angiogenesis and promoted the ability of melanoma cells to migrate towards endothelial cells and use selective motility cues on their surfaces. Our results not only reveal how UV irradiation of epidermal keratinocytes is sensed by the innate immune system, but also show that the resulting inflammatory response catalyses reciprocal melanoma-endothelial cell interactions leading to perivascular invasion, a phenomenon originally described as angiotropism in human melanomas by histopathologists. Angiotropism represents a hitherto underappreciated mechanism of metastasis that also increases the likelihood of intravasation and haematogenous dissemination. Consistent with our findings, ulcerated primary human melanomas with abundant neutrophils and reactive angiogenesis frequently show angiotropism and a high risk for metastases. Our work indicates that targeting the inflammation-induced phenotypic plasticity of melanoma cells and their association with endothelial cells represent rational strategies to specifically interfere

  14. Comparison of artificial intelligence methods and empirical equations to estimate daily solar radiation

    Science.gov (United States)

    Mehdizadeh, Saeid; Behmanesh, Javad; Khalili, Keivan

    2016-08-01

    In the present research, three artificial intelligence methods including Gene Expression Programming (GEP), Artificial Neural Networks (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) as well as, 48 empirical equations (10, 12 and 26 equations were temperature-based, sunshine-based and meteorological parameters-based, respectively) were used to estimate daily solar radiation in Kerman, Iran in the period of 1992-2009. To develop the GEP, ANN and ANFIS models, depending on the used empirical equations, various combinations of minimum air temperature, maximum air temperature, mean air temperature, extraterrestrial radiation, actual sunshine duration, maximum possible sunshine duration, sunshine duration ratio, relative humidity and precipitation were considered as inputs in the mentioned intelligent methods. To compare the accuracy of empirical equations and intelligent models, root mean square error (RMSE), mean absolute error (MAE), mean absolute relative error (MARE) and determination coefficient (R2) indices were used. The results showed that in general, sunshine-based and meteorological parameters-based scenarios in ANN and ANFIS models presented high accuracy than mentioned empirical equations. Moreover, the most accurate method in the studied region was ANN11 scenario with five inputs. The values of RMSE, MAE, MARE and R2 indices for the mentioned model were 1.850 MJ m-2 day-1, 1.184 MJ m-2 day-1, 9.58% and 0.935, respectively.

  15. Adverse effects of ultraviolet radiation from the use of indoor tanning equipment: time to ban the tan.

    Science.gov (United States)

    Lim, Henry W; James, William D; Rigel, Darrell S; Maloney, Mary E; Spencer, James M; Bhushan, Reva

    2011-04-01

    The incidence of melanoma skin cancer is increasing rapidly, particularly among young women in the United States. Numerous studies have documented an association between the use of indoor tanning devices and an increased risk of skin cancer, especially in young women. Studies have shown that ultraviolet exposure, even in the absence of erythema or burn, results in DNA damage. Countries and regulatory bodies worldwide have recognized the health risks associated with indoor tanning. In the United States, 32 states have passed legislation to regulate the indoor tanning industry, but there is an urgent need to restrict the use of indoor tanning devices at the federal level. The Food and Drug Administration is currently reviewing the classification of these devices. For all of these reasons, the Food and Drug Administration should prohibit the use of tanning devices by minors and reclassify tanning devices to at least class II to protect the public from the preventable cancers and other adverse effects caused by ultraviolet radiation from indoor tanning. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  16. Characterization and standardization of a thermoluminescent dosimetric system to ultraviolet and laser radiation using CaSO4:Dy

    International Nuclear Information System (INIS)

    Grossi, Fabio Henrique

    2002-01-01

    The photo transferred thermoluminescence (PTTL) was used to characterize a dosimetric system to the laser and ultraviolet radiation. Dysprosium activated calcium sulphate samples (CaSO 4 :Dy) used are produced at Instituto de Pesquisas Energeticas e Nucleares (IPEN) and have proved been an excellent dosimetric material for non ionizing radiation. PTTL signal was studied for UV radiation detection in the 220 to 450 nm range and for laser radiation in the 193 to 1.160 nm range. The samples presented more sensibility to the 193, 250, 310 and 337 nm wavelengths and no sensibility to infrared region. The samples presented linear PTTL in function of radiant exposure, excitation gamma dose in the range between 5 and 100 Gy and laser beam diameter between 2 and 6 nm. Another parameters studied were the angular dependence, UV lower exposure limit and PTTL signal optical fading. Spread laser radiation analysis was performed in the Ophthalmologic Department of Universidade Federal de Sao Paulo (UNIFESP) surgical center, showing that samples positioned as far as 4 m from laser source are sensitized to the laser radiation, as well as evaluating the laser exposure received by workers of medical area. A method to send the samples by mail was developed to the studies performed in the UNIFESP. (author)

  17. Decrease in artificial tanning by French teenagers: 2011-2016.

    Science.gov (United States)

    Say, Matthieu; Beauchet, Alain; Vouldoukis, Ioannis; Beauchet, Pascale; Boudet, Monique; Tella, Emilie; Mahé, Emmanuel

    2018-03-13

    The major risk factor for skin cancers is exposure to solar and artificial ultraviolet radiation, in particular during childhood and adolescence. In France, a law was restricted for tanning-bed access to adults (≥18 years) since 1997. To evaluate teenagers' artificial tanning behaviour in 2016 and to compare results with those obtained in a similar survey performed in 2011. The SOLADO 2011 and 2016 surveys were conducted in a general school in Antony and a technical school in Fontenay-aux-Roses (Paris suburb). In 2016, 630 teenagers (mean age: 14.2 ± 1.9 y: Males/Females: 301/329) completed the questionnaire, 1.3% of teenagers reported using tanning beds, 1.1% tanning pills and 8.9% tanning creams. Between 2011 and 2016, the use of tanning beds decreased from 1.4% to 0.7% in Antony (P = .26) and from 9.5% to 4.8% in Fontenay-aux-Roses (P = .01), and the use of tanning creams from 39.8% to 17.6% in Fontenay-aux-Rose (P = .0007). The incidence of sunburn decreased from 60.5% to 54.0% in Antony (P = .02) and from 55.4% to 42.4% in Fontenay-aux-Roses (P = .05). As compared to 2011, teenagers used artificial tanning methods less frequently in 2016. In particular, they used tanning beds less frequently, suggesting that the new stricter legislation has been effective. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Solar ultraviolet irradiance variations: a review

    International Nuclear Information System (INIS)

    Lean, J.

    1987-01-01

    Despite the geophysical importance of solar ultraviolet radiation, specific aspects of its temporal variations have not yet been adequately determined experimentally, nor are the mechanisms for the variability completely understood. Satellite observations have verified the reality of solar ultraviolet irradiance variations over time scales of days and months, and model calculations have confirmed the association of these short-term variations with the evolution and rotation of regions of enhanced magnetic activity on the solar disc. However, neither rocket nor satellite measurements have yet been made with sufficient accuracy and regularity to establish unequivocally the nature of the variability over the longer time of the 11-year solar cycle. The comparative importance for the long-term variations of local regions of enhanced magnetic activity and global scale activity perturbations is still being investigated. Solar ultraviolet irradiance variations over both short and long time scales are reviewed, with emphasis on their connection to solar magnetic activity. Correlations with ground-based measures of solar variability are examined because of the importance of the ground-based observations as historical proxies of ultraviolet irradiance variations. Current problems in understanding solar ultraviolet irradiance variations are discussed, and the measurements planned for solar cycle 22, which may resolve these problems, are briefly described. copyright American Geophysical Union 1987

  19. Skin Erythema, Pigmentation and Hydration Kinetics after Ultraviolet Radiation-induced Photodamage in Southern Chinese Women.

    Science.gov (United States)

    Wan, Miaojian; Hu, Rong; Xie, Xiaoyuan; Gong, Zijian; Yi, Jinling; Chen, Haiyan; Xie, Lin; Guan, Xiaomin; Guan, Lei; Lai, Wei

    2017-10-01

    Although there have been some studies about changes of skin erythema and pigmentation following ultraviolet radiation in other races, the relevant data in Chinese have never been achieved. Thus, we evaluated the long-time course of skin erythema, pigmentation and hydration changes after different doses of solar-simulated ultraviolet (SSUV) irradiation in 26 Chinese women for 168 days. The erythema index increased abruptly and peaked during 3 days of SSUV exposure, then slowly returned to the baseline level starting at day 7 and completely recovered during 168-day course of this study only in one minimal erythema doses (MED) SSUV irradiation. The melanin index started to slowly increase at day 3 of SSUV exposure, peaking at day 14 and gradually returned to the baseline level thereafter, but did not return to the baseline level during 168-day course in all doses. Skin hydration slowly declined at day 3 of exposure, hitting the lowest point at day 7, then slowly recovered starting at day 14 and completely returned to the baseline level at day 28 only in 1.5MED. These results will serve as baseline data on Chinese skin and provide useful references for the treatment of serious skin photodamage in Chinese. © 2017 The American Society of Photobiology.

  20. Radiological Impact of artificial and naturally radiation sources. Report of the UNSCEAR, 2008

    International Nuclear Information System (INIS)

    Cancio, David

    2010-01-01

    Results in the report of the Scientific Committee of the United Nations for Study of the Effects of Atomic Radiations, presented in the 56th period of sessions in July 2008; values obtained from natural sources or from artificial ones are compared and, in accordance with their effects on humans. It is concluded that the most significant change in the situation, between reports, has been the increase in the medical exposure due to the increase in the number of computed tomography examinations. (author)

  1. Bioprocess of Kosa bioaerosols: effect of ultraviolet radiation on airborne bacteria within Kosa (Asian dust).

    Science.gov (United States)

    Kobayashi, Fumihisa; Maki, Teruya; Kakikawa, Makiko; Yamada, Maromu; Puspitasari, Findya; Iwasaka, Yasunobu

    2015-05-01

    Kosa (Asian dust) is a well-known weather phenomenon in which aerosols are carried by the westerly winds from inland China to East Asia. Recently, the frequency of this phenomenon and the extent of damage caused have been increasing. The airborne bacteria within Kosa are called Kosa bioaerosols. Kosa bioaerosols have affected ecosystems, human health and agricultural productivity in downwind areas. In order to develop a new and useful bacterial source and to identify the source region of Kosa bioaerosols, sampling, isolation, identification, measurement of ultraviolet (UV) radiation tolerance and experimental simulation of UV radiation conditions were performed during Kosa bioaerosol transportation. We sampled these bioaerosols using a Cessna 404 airplane and a bioaerosol sampler at an altitude of approximately 2900 m over the Noto Peninsula on March 27, 2010. The bioaerosol particles were isolated and identified as Bacillus sp. BASZHR 1001. The results of the UV irradiation experiment showed that the UV radiation tolerance of Kosa bioaerosol bacteria was very high compared with that of a soil bacterium. Moreover, the UV radiation tolerance of Kosa bioaerosol spores was higher than that of soil bacterial spores. This suggested that Kosa bioaerosols are transported across the atmosphere as living spores. Similarly, by the experimental simulation of UV radiation conditions, the limited source region of this Kosa bioaerosol was found to be southern Russia and there was a possibility of transport from the Kosa source area. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. Radiation curable coatings having nonadherent surfaces

    International Nuclear Information System (INIS)

    Gaske, J.E.; Georgas, N.T.

    1977-01-01

    Radiation polymerizable coatings having nonadherent surfaces are provided utilizing nonaqueous emulsions of a liquid alkyl hydrogen polysiloxane in a radiation polymerizable polyethylenic liquid. Polyacrylates in combination with amines, and ultraviolet photosensitizers are particularly contemplated for rapid nonair inhibited ultraviolet cure. 13 claims

  3. Effects of ultraviolet-B radiation on the growth, physiology and cannabinoid production of Cannabis sativa L

    International Nuclear Information System (INIS)

    Lydon, J.

    1986-01-01

    The concentration of cannabinoids in Cannabis sativa L. is correlated with high ultraviolet-B (UV-B) radiation environments. Δ 9 -Tetrahydrocannabinolic acid and cannabidiolic acid, both major secondary products of C. sativa, absorb UV-B radiation and may function as solar screens. The object of this study was to test the effects of UV-B radiation on the physiology and cannabinoid production of C. sativa. Drug and fiber-type C. sativa were irradiated with three levels of UV-B radiation for 40 days in greenhouse experiments. Physiological measurements on leaf tissues were made by infra-red gas analysis. Drug and fiber-type control plants had similar CO 2 assimilation rates from 26 to 32 0 C. Drug-type control plant had higher dark respiration rates and stomatal conductances than fiber-type control plants. The concentration of Δ 9 -THC, but not of other cannabinoids) in both vegetative and reproductive tissues increased with UV-B dose in drug-type plants. None of the cannabinoids in fiber-type plants were affected by UV-B radiation. The increased level of Δ 9 -THC found in leaves after irradiation may account for the physiological and morphological insensitivity to UV-B radiation in the drug-type plants. However, fiber plants showed no comparable change in the level of cannabidoil (CBD). Resin stripped form fresh fiber-type floral tissue by sonication was spotted on filter paper and irradiated continuously for 7 days. Cannabidiol (CBD) gradually decreased when irradiated but Δ 9 -THC and cannabichromene did not

  4. Effects of ultraviolet-B radiation on the growth, physiology and cannabinoid production of Cannabis sativa L

    Energy Technology Data Exchange (ETDEWEB)

    Lydon, J.

    1986-01-01

    The concentration of cannabinoids in Cannabis sativa L. is correlated with high ultraviolet-B (UV-B) radiation environments. ..delta../sup 9/-Tetrahydrocannabinolic acid and cannabidiolic acid, both major secondary products of C. sativa, absorb UV-B radiation and may function as solar screens. The object of this study was to test the effects of UV-B radiation on the physiology and cannabinoid production of C. sativa. Drug and fiber-type C. sativa were irradiated with three levels of UV-B radiation for 40 days in greenhouse experiments. Physiological measurements on leaf tissues were made by infra-red gas analysis. Drug and fiber-type control plants had similar CO/sub 2/ assimilation rates from 26 to 32/sup 0/C. Drug-type control plant had higher dark respiration rates and stomatal conductances than fiber-type control plants. The concentration of ..delta../sup 9/-THC, but not of other cannabinoids) in both vegetative and reproductive tissues increased with UV-B dose in drug-type plants. None of the cannabinoids in fiber-type plants were affected by UV-B radiation. The increased level of ..delta../sup 9/-THC found in leaves after irradiation may account for the physiological and morphological insensitivity to UV-B radiation in the drug-type plants. However, fiber plants showed no comparable change in the level of cannabidoil (CBD). Resin stripped form fresh fiber-type floral tissue by sonication was spotted on filter paper and irradiated continuously for 7 days. Cannabidiol (CBD) gradually decreased when irradiated but ..delta../sup 9/-THC and cannabichromene did not.

  5. Tanning lamps ultraviolet emissions and compliance with technical standards

    International Nuclear Information System (INIS)

    Bonino, A.; Facta, S.; Saudino, S.; Anglesio, L.; D'Amore, G.

    2009-01-01

    In this work the compliance of tanning lamps with technical standards EN 60335-2-27 'Household and similar electrical appliances-Safety. Part 2: Particular requirements for appliances for skin exposure to ultraviolet and infrared radiation' was analysed. Results of this analysis showed that none of the examined technical documentation produced by the lamps manufacturers is fully compliant with the standard technique. Furthermore data reported in the same manuals, such as effective radiant exposure or irradiance, would indicate that these sources may be the cause of undue exposure to ultraviolet (UV) radiation. For this reason a measurement campaign on UV lamps used in tanning salons was organised. The first results of these measurements seem to confirm the doubts raised from the analysis of the lamp manuals: the use of a tanning lamp can lead to UV radiation exposure levels higher than reference maximum values recommended by EN 60335-2-27. (authors)

  6. Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

    International Nuclear Information System (INIS)

    Thorseth, Trond Morten

    2000-01-01

    The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe

  7. Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

    Energy Technology Data Exchange (ETDEWEB)

    Thorseth, Trond Morten

    2000-07-01

    The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe.

  8. Animal model for evaluation of topical photoprotection against ultraviolet A (320-380 nm) radiation

    International Nuclear Information System (INIS)

    Chew, S.; DeLeo, V.A.; Harber, L.C.

    1987-01-01

    Recent studies reporting UVA (ultraviolet A radiation 320-380 nm) as an integral part of the cumulative sun-induced damage in human skin have prompted an interest in developing effective UVA photoprotective agents. The development of such compounds has been impeded by the absence of a clinically relevant animal model for evaluating their efficacy. This report describes the development and use of such a laboratory animal system. Selected concentrations of oxybenzone (2-hydroxy-4-methoxybenzophenone) in vehicle (0.1% to 6%) or vehicle alone were applied to the depilated dorsal skin of 30 Hartley strain female albino guinea pigs. The skin was irradiated with solar simulated UVA from a xenon light source. Acute radiation-induced damage was assayed by erythema grading and inhibition of [ 3 H]thymidine incorporation into epidermal DNA. Data from erythema grading studies indicated that a significant degree of photoprotection was achieved with 6%, 3%, and 1% solutions of benzophenone compared with the control vehicle; the 6% solution was significantly more photoprotective than the 3% and 1% solutions. A 6% solution afforded significant photoprotection when assayed by [ 3 H]thymidine incorporation

  9. Effects of ultraviolet radiation on photosynthetic performance and N2 fixation in Trichodesmium erythraeum IMS 101

    Science.gov (United States)

    Cai, Xiaoni; Hutchins, David A.; Fu, Feixue; Gao, Kunshan

    2017-10-01

    Biological effects of ultraviolet radiation (UVR; 280-400 nm) on marine primary producers are of general concern, as oceanic carbon fixers that contribute to the marine biological CO2 pump are being exposed to increasing UV irradiance due to global change and ozone depletion. We investigated the effects of UV-B (280-320 nm) and UV-A (320-400 nm) on the biogeochemically critical filamentous marine N2-fixing cyanobacterium Trichodesmium (strain IMS101) using a solar simulator as well as under natural solar radiation. Short exposure to UV-B, UV-A, or integrated total UVR significantly reduced the effective quantum yield of photosystem II (PSII) and photosynthetic carbon and N2 fixation rates. Cells acclimated to low light were more sensitive to UV exposure compared to high-light-grown ones, which had more UV-absorbing compounds, most likely mycosporine-like amino acids (MAAs). After acclimation under natural sunlight, the specific growth rate was lower (by up to 44 %), MAA content was higher, and average trichome length was shorter (by up to 22 %) in the full spectrum of solar radiation with UVR, than under a photosynthetically active radiation (PAR) alone treatment (400-700 nm). These results suggest that prior shipboard experiments in UV-opaque containers may have substantially overestimated in situ nitrogen fixation rates by Trichodesmium, and that natural and anthropogenic elevation of UV radiation intensity could significantly inhibit this vital source of new nitrogen to the current and future oligotrophic oceans.

  10. Invisible marking system by extreme ultraviolet radiation: the new frontier for anti-counterfeiting tags

    International Nuclear Information System (INIS)

    Lazzaro, P. Di; Bollanti, S.; Flora, F.; Mezi, L.; Murra, D.; Torre, A.; Bonfigli, F.; Montereali, R.M.; Vincenti, M.A.

    2016-01-01

    We present a marking technology which uses extreme ultraviolet radiation to write invisible patterns on tags based on alkali fluoride thin films. The shape of the pattern is pre-determined by a mask (in the case of contact lithography) or by a suitable mirror (projection lithography). Tags marked using this method offer a much better protection against fakes than currently available anti-counterfeiting techniques. The complexity and cost of this technology can be tailored to the value of the good to be protected, leaving, on the other hand, the specific reading technique straightforward. So far, we have exploited our invisible marking to tag artworks, identity cards, electrical components, and containers of radioactive wastes. Advantages and limits of this technology are discussed in comparison with the anti-counterfeiting systems available in the market.

  11. Mutagenic action of non-ionizing radiations: its implication in radiation protection

    International Nuclear Information System (INIS)

    Madhvanath, U.; Subrahmanyam, P.; Sankaranarayanan, N.; Singh, D.R.

    1977-01-01

    Mutagenic effects of non-ionizing radiations except in the ultraviolet and near ultraviolet region are just not known. Results of the investigation carried out using a sensitive diploid yeast system, are presented. The arginine requiring mutant yeast strain BZ34 reverts to prototrophy following exposure to ionizing radiation. Reversion frequencies were determined following exposure to UV (254 nm), near ultraviolet (313, 353 nm) visible region (480 nm), neodymium laser (1.01 μm) and microwave (2450 MHz) radiations. An Aminco - Bowman Spectrophotofluorimeter was used to obtain wavelengths from UV to visible region. Yeast suspensions (concentration of 10 7 cells/ml) were irradiated to doses ranging from 10 7 to 10 9 erg/cm 3 as determined with potassium ferri-oxalate system. Exposure to laser pulses and microwave radiation ranged up to 45 J/cm 2 and 60 mW-h/cm 2 respectively. Results showed that the reversion induction efficiency decreased by six orders of magnitude from ionizing radiations to ultraviolet for the same absorbed dose and this efficiency has further decreased by a factor of fifteen when the wavelength is increased from 254 nm to 313 nm. Although killing could be effected with laser beams (45 J/cm 2 for 50% survival) no increase in the reversion was observed than the background level. It is concluded that radiation of wavelengths higher than 450 nm up to 12 cm studied is not mutagenic and with sufficient intensities of these radiations only killing of cells is possible due to thermal effects. This finding is compared with other known functional and morphological effects at cellular level due to low-level exposures of non-ionizing radiations

  12. Highly efficient deep ultraviolet generation by sum-frequency mixing ...

    Indian Academy of Sciences (India)

    Ultraviolet laser radiation; walk-off compensation; third harmonic generation; nonlinear optical material. ... Because of its large birefringence, BBO crystal permits the generation of UV radiation near 200 nm by THG ... A, B and C are three different configurations for THG, A – Single crystal, B – two crystals (B2 and B3 in.

  13. Solar and artificial radiation: health effects and protective measures -- position statement and overview. (RSU 118/OT0799)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-16

    Sunburn is the skin's visible reaction to acute overexposure to ultraviolet radiation (UVR). It is estimated that in any given year there are about 3,150 new cases of malignant melanoma, the deadliest kind of skin cancer, and 64,000 new cases of non-melanoma skin cancers in Canada. Between 1986 and 1995 the age-standardized mortality of malignant melanoma increased by an annual average of 2.7 per cent among men and 1.7 per cent among women, the largest increase in mortality of all cancers in men and the second largest among women. This report provides a brief overview of the main characteristics, sources and health effects of ultraviolet radiation, along with a description of general protective measures and recommendations for specific settings. The expectation is that the document will help to promote sound UVR exposure reduction practices, and by so doing, help to reduce the negative health effects of overexposure to UVR among Canadians. The recommended protective measures include minimizing sun exposure (including exposure to sunlamps which are not considered a safe way to get a tan); seeking shade, especially from 11.00 AM to 4.00 PM; covering up; using a sunscreen with SPF 15 or higher that has both UV and UVB protection; and using lip and eye protection. Practising regular skin self-examination is also recommended.

  14. Protection of humans from ultraviolet radiation through the use of textiles: a review

    International Nuclear Information System (INIS)

    Capjack, L.; Kerr, N.; Davis, S.; Fedosejevs, R.; Hatch, K.L.; Markee, N.L.

    1994-01-01

    One of the growing concerns of the present decade is the health risk associated with exposure to ultraviolet radiation (UVR) and its link with problems such as carcinogenesis, cataracts, sunburn, and photoaging. For protection from UVR, medical experts recommend avoiding exposure, using sunscreens, donning hats, and covering up with clothing. Research on the solar-protective value of clothing, however, still leaves many questions unanswered. This review of literature identifies the need for appropriate protection from the sun, especially for children, and the benefits of clothing as protection. The methods and difficulties associated with assessing the UVR protection and the definition of the sun protection factor (SPF) of clothing are outlined and discussed. Studies using in vivo, radiometric, and spectrophotometric methodologies to assess the UVR transmission throughfabrics are examined. Fabric variables, identified in the literature, that have been found to affect UVR transmission values are discussed

  15. The interaction of ultraviolet light with Arctic sea ice during SHEBA

    Science.gov (United States)

    Perovich, Donald K.

    The reflection, absorption and transmission of ultraviolet light by a sea-ice cover strongly impacts primary productivity, higher trophic components of the food web, and humans. Measurements of the incident irradiance at 305, 320, 340 and 380 nm and of the photosynthetically active radiation were made from April through September 1998 as part of the SHEBA (Surface Heat Budget of the Arctic Ocean program) field experiment in the Arctic Ocean. In addition, observations of snow depth and ice thickness were made at more than 100 sites encompassing a comprehensive range of conditions. The thickness observations were combined with a radiative transfer model to compute a time series of the ultraviolet light transmitted by the ice cover from April through September. Peak values of incident ultraviolet irradiance occurred in mid-June. Peak transmittance was later in the summer at the end of the melt season when the snow cover had completely melted, the ice had thinned and pond coverage was extensive. The fraction of the incident ultraviolet irradiance transmitted through the ice increased by several orders of magnitude as the melt season progressed. Ultraviolet transmittance was approximately a factor of ten greater for melt ponds than bare ice. Climate change has the potential to alter the amplitude and timing of the annual albedo cycle of sea ice. If the onset of melt occurs at increasingly earlier dates, ultraviolet transmittance will be significantly enhanced, with potentially deleterious biological impacts.

  16. Influence of altitude and enhanced ultraviolet-B radiation on tuber production, seed viability, leaf pigments and morphology in the wild potato species Solanum kurtzianum Bitter & Wittm collected from an elevational gradient.

    Science.gov (United States)

    Ibañez, V N; Berli, F J; Masuelli, R W; Bottini, R A; Marfil, C F

    2017-08-01

    Climate change could lead to an upward shift in plant distribution, exposing populations to higher levels of ultraviolet (UV)-B radiation. In the framework of an in situ strategy for conserving potato wild relatives, we evaluated the effect of high UV-B levels on natural population of Solanum kurtzianum. The hypothesis is that plants from naturally higher altitudes are more adapted to increased UV-B radiation. Two populations from low and high altitudes were field supplemented using UV-B-lamps (+UV-B) or excluded from it with plastic filters. Additionally, to assess in which extent the plant responses to these artificial experimental conditions are reproducible in natural conditions, three genotypes were cultivated in two mountain experimental gardens (EG) at different elevations. +UV-B treatment induced changes in leaf morphology and increases in phenolic compounds in both populations, indicating plant adaptation, since chlorophylls and reproductive structures were not negatively affected. These results indicate that this environmental factor may not limit the displacement of populations towards sites with higher UV-B levels. Meanwhile, in higher-altitude EG a tubers yield reduction, mainly through a decreased tuber number and a bigger accumulation of phenolic compounds than in +UV-B treatment were observed, suggesting that UV-B is not the only factor involved in plants adaptation to high altitude environments. Copyright © 2017. Published by Elsevier B.V.

  17. Combined effects of Lanthanum(III) and elevated Ultraviolet-B radiation on root nitrogen nutrient in soybean seedlings.

    Science.gov (United States)

    Huang, Guangrong; Wang, Lihong; Sun, Zhaoguo; Li, Xiaodong; Zhou, Qing; Huang, Xiaohua

    2015-02-01

    Rare earth element pollution and elevated ultraviolet-B (UV-B) radiation occur simultaneously in some regions, but the combined effects of these two factors on plants have not attracted enough attention. Nitrogen nutrient is vital to plant growth. In this study, the combined effects of lanthanum(III) and elevated UV-B radiation on nitrate reduction and ammonia assimilation in soybean (Glycine max L.) roots were investigated. Treatment with 0.08 mmol L(-1) La(III) did not change the effects of elevated UV-B radiation on nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthase (GOGAT), glutamate dehydrogenase (GDH), nitrate, ammonium, amino acids, or soluble protein in the roots. Treatment with 0.24 mmol L(-1) La(III) and elevated UV-B radiation synergistically decreased the NR, NiR, GS, and GOGAT activities as well as the nitrate, amino acid, and soluble protein levels, except for the GDH activity and ammonium content. Combined treatment with 1.20 mmol L(-1) La(III) and elevated UV-B radiation produced severely deleterious effects on all test indices, and these effects were stronger than those induced by La(III) or elevated UV-B radiation treatment alone. Following the withdrawal of La(III) and elevated UV-B radiation, all test indices for the combined treatments with 0.08/0.24 mmol L(-1) La(III) and elevated UV-B radiation recovered to a certain extent, but they could not recover for treatments with 1.20 mmol L(-1) La(III) and elevated UV-B radiation. In summary, combined treatment with La(III) and elevated UV-B radiation seriously affected nitrogen nutrition in soybean roots through the inhibition of nitrate reduction and ammonia assimilation.

  18. Ultraviolet-B lethal damage on Pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Degiorgi, C.F.; Fernandez, R.O.; Pizarro, R.A.

    1996-01-01

    Pseudomonas aeruginosa has shown an increased sensitivity compared with that of Escherichia coli and Enterobacter cloacae, when they were exposed to 0.4 kJ/m2 of ultraviolet-B radiation. The rapid decay in cell viability observed in Pseudomonas aeruginosa after the irradiation was influenced by factors such as culture media and the presence of pyocyanine during the irradiation. The radioinduced lethal damage could be prevented by photoreactivating treatment, indicating that pyrimidine dimer formation was the mechanism causing bacterial death. The results indicate that several environmental conditions may act as protective agents against ultraviolet-B-induced damage

  19. High intensity vacuum ultraviolet and extreme ultraviolet production by noncollinear mixing in laser vaporized media

    Energy Technology Data Exchange (ETDEWEB)

    Todt, Michael A.; Albert, Daniel R.; Davis, H. Floyd, E-mail: hfd1@cornell.edu [Baker Laboratory, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301 (United States)

    2016-06-15

    A method is described for generating intense pulsed vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) laser radiation by resonance enhanced four-wave mixing of commercial pulsed nanosecond lasers in laser vaporized mercury under windowless conditions. By employing noncollinear mixing of the input beams, the need of dispersive elements such as gratings for separating the VUV/XUV from the residual UV and visible beams is eliminated. A number of schemes are described, facilitating access to the 9.9–14.6 eV range. A simple and convenient scheme for generating wavelengths of 125 nm, 112 nm, and 104 nm (10 eV, 11 eV, and 12 eV) using two dye lasers without the need for dye changes is described.

  20. Modeling of solar radiation using remote sensing and artificial neural network in Turkey

    International Nuclear Information System (INIS)

    Senkal, Ozan

    2010-01-01

    Artificial neural networks (ANNs) were used to estimate solar radiation in Turkey (26-45 o E, 36-42 o N) using geographical and satellite-estimated data. In order to train the Generalized regression neural network (GRNN) geographical and satellite-estimated data for the period from January 2002 to December 2002 from 19 stations spread over Turkey were used in training (ten stations) and testing (nine stations) data. Latitude, longitude, altitude, surface emissivity for ε 4, surface emissivity for ε 5, and land surface temperature are used in the input layer of the network. Solar radiation is the output. Root Mean Square Error (RMSE) and correlation coefficient (R 2 ) between the estimated and measured values for monthly mean daily sum with ANN values have been found as 0.1630 MJ/m 2 and 95.34% (training stations), 0.3200 MJ/m 2 and 93.41% (testing stations), respectively. Since these results are good enough it was concluded that the developed GRNN tool can be used to predict the solar radiation in Turkey.