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Sample records for sunlight exposure testing

  1. Ultra-accelerated natural sunlight exposure testing

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.J.; Bingham, C.; Goggin, R.; Lewandowski, A.A.; Netter, J.C.

    2000-06-13

    Process and apparatus are disclosed for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: (a) concentrating solar flux uniformly; (b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  2. Ultra-accelerated natural sunlight exposure testing

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, Gary J. (Pine, CO); Bingham, Carl (Lakewood, CO); Goggin, Rita (Englewood, CO); Lewandowski, Allan A. (Evergreen, CO); Netter, Judy C. (Westminster, CO)

    2000-06-13

    Process and apparatus for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: a) concentrating solar flux uniformly; b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  3. Supplementing vitamin D through sunlight: associating health literacy with sunlight exposure behavior.

    Science.gov (United States)

    Leung, Angela Yee Man; Cheung, Mike Kwun Ting; Chi, Iris

    2015-01-01

    To test whether health literacy is associated with sunlight exposure behavior, we interviewed 648 Chinese adults aged 65 years or older. Using the information-motivation-behavioral skills model and structural equation modeling, we tested whether health literacy was associated with the complex relationships among knowledge about vitamin D, attitudes toward sunlight exposure, doctor recommendations regarding sunlight exposure, and sunlight exposure behavior. Health literacy was directly associated with sunlight exposure (β=.20, psunlight exposure through health literacy (β=.46, psunlight exposure through health literacy (β=-.12, psunlight exposure. Providing relevant knowledge or making doctor recommendations might not be effective. Training should focus on individuals with low health literacy who may be less likely to receive sunlight exposure. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Sunlight exposure: Do health benefits outweigh harm?

    Science.gov (United States)

    Razzaque, Mohammed S

    2016-09-16

    Vitamin D is a fat-soluble vitamin whose levels within the body are elevated following sunlight exposure. Numerous studies have shown that sunlight exposure can provide protection to a wide variety of diseases, ranging from different types of tumors to hypertension to type 1 diabetes to multiple sclerosis. Moreover, studies have shown that avoiding sunlight may influence the initiation and progression of some of these diseases. Avoidance of sunlight, coupled with the inclination towards consuming supplements, is becoming the primary choice to obtain vitamin D. The purpose of this article is to present evidences from published literature, to show that the expected benefits of vitamin D supplements are minimized by the potential risk of cardiovascular events and beyond. Since hypovitaminosis D status usually reflects reduced sunlight exposure, the obvious primary replacement should be safe sunlight exposure, and not exogenous supplements. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Sunlight exposure assessment: can we accurately assess vitamin D exposure from sunlight questionnaires?

    Science.gov (United States)

    McCarty, Catherine A

    2008-04-01

    The purpose of this review is to summarize the peer-reviewed literature in relation to sunlight exposure assessment and the validity of using sunlight exposure questionnaires to quantify vitamin D status. There is greater variability in personal ultraviolet (UV) light exposure as the result of personal behavior than as the result of ambient UV light exposure. Although statistically significant, the correlation coefficients for the relation between personal report of sun exposure and ambient UV light measured by dosimetry (assessment of radiation dose) are relatively low. Moreover, the few studies to assess the relation between sunlight measures and serum 25-hydroxyvitamin D show low correlations. These low correlations may not be surprising given that personal factors like melanin content in skin and age also influence cutaneous synthesis of vitamin D. In summary, sunlight exposure questionnaires currently provide imprecise estimates of vitamin D status. Research should be directed to develop more objective, nonintrusive, and economical measures of sunlight exposure to quantify personal vitamin D status.

  6. Sunlight exposure and multiple sclerosis in a tropical country.

    Science.gov (United States)

    Espinosa-Ramírez, Guillermo; Ordoñez, Graciela; Flores-Rivera, Jose; Sotelo, Julio

    2014-07-01

    We analysed past and current sun exposure in multiple sclerosis (MS) patients as compared with matched controls in Mexico, a country with tropical climate. In a case-controlled study that include 83 MS patients and 166 matched controls, we inquired about sunlight exposure in two different periods: during adolescence and during the immediate past 5 years. Indicators were: exposure on quotidian and weekend outdoor activities with direct sunlight contact as expressed on frequency by mean number of days, daytime (morning, noon, afternoon), number of hours, visits to sunny places, and use of sunblocking agents. Additional elements were socioeconomic status, skin colour, and antecedent of varicella infection during childhood. MS patients showed a larger proportion of white skin. MS patients had more sunlight exposure during adolescence (80% versus 60%, P = 0·002); this tendency prevailed on current indicators (46% versus 30%, P = 0·02). However, current exposure on weekends (10% versus 22%, P = 0·02) and visits to the beach (64% versus 98%, P = 0·002) were lower in MS than in controls. Mexico gets more sunlight through the year than areas with high incidence of MS; nevertheless, its prevalence has greatly increased over the last decades, making it a relevant emerging disease. Our results indicate that in a tropical country, there is no association between sunlight exposure and the risk to develop MS, given the immunological effects of sunlight exposure either through UV radiation or vitamin D metabolism.

  7. Sunlight exposure-mediated DNA damage in young adults.

    Science.gov (United States)

    Kato, Masashi; Iida, Machiko; Goto, Yuji; Kondo, Takaaki; Yajima, Ichiro

    2011-08-01

    Previous experimental studies showed that single ultraviolet B (UVB) light irradiation increased levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a well-established biomarker of carcinogenesis and oxidative DNA damage, in epithelial cells in animals and humans. We conducted for the first time an epidemiologic study to investigate the correlations among levels of oxidative DNA damage, skin pigmentation, and sunlight exposure in human daily life. Digitalized skin pigmentation levels and creatinine-adjusted urinary 8-OHdG levels were examined in 127 healthy young adults aged 20 to 24 years and in hairless mice with normal pigmented skin (HL-mice; n = 20) and hyperpigmented skin (HL-HPS-mice; n = 20). Data obtained by a questionnaire were also analyzed for the 127 subjects. Binary logistic regression analysis showed that increased sunlight intensity, but not sunlight-exposed time or sunlight-exposed skin area, was correlated with elevation in creatinine-adjusted urinary 8-OHdG levels. In contrast, increased skin pigmentation level, but not the use of sunscreen, was correlated with reduction in urinary 8-OHdG level in humans. UVB irradiation corresponding to several minutes of sunlight exposure significantly increased urinary 8-OHdG levels in HL-mice but not in HL-HPS-mice. We showed that increase in intensity of sunlight in human daily life increased levels of DNA damage. We also showed a protective effect of skin pigmentation on sunlight exposure-mediated DNA damage. We have provided more reliable evidence of routine sunlight exposure-mediated DNA damage in humans through the combination of epidemiologic and experimental studies. ©2011 AACR.

  8. Sunlight exposure, antioxidants, and age-related macular degeneration.

    Science.gov (United States)

    Fletcher, Astrid E; Bentham, Graham C; Agnew, Maureen; Young, Ian S; Augood, Cristina; Chakravarthy, Usha; de Jong, Paulus T V M; Rahu, Mati; Seland, Johan; Soubrane, Gisele; Tomazzoli, Laura; Topouzis, Fotis; Vingerling, Johannes R; Vioque, Jesus

    2008-10-01

    To examine the association of sunlight exposure and antioxidant level with age-related macular degeneration (AMD). Four thousand seven hundred fifty-three participants aged 65 years or older in the European Eye Study underwent fundus photography, were interviewed for adult lifetime sunlight exposure, and gave blood for antioxidant analysis. Blue light exposure was estimated by combining meteorologic and questionnaire data. Data on sunlight exposure and antioxidants were available in 101 individuals with neovascular AMD, 2182 with early AMD, and 2117 controls. No association was found between blue light exposure and neovascular or early AMD. Significant associations were found between blue light exposure and neovascular AMD in individuals in the quartile of lowest antioxidant level-vitamin C, zeaxanthin, vitamin E, and dietary zinc-with an odds ratio of about 1.4 for 1 standard deviation unit increase in blue light exposure. Higher odds ratios for blue light were observed with combined low antioxidant levels, especially vitamin C, zeaxanthin, and vitamin E (odds ratio, 3.7; 95% confidence interval, 1.6-8.9), which were also associated with early stages of AMD. Although it is not possible to establish causality between sunlight exposure and neovascular AMD, our results suggest that people in the general population should use ocular protection and follow dietary recommendations for the key antioxidant nutrients.

  9. Exposure time to sunlight for ultra violet light therapy

    Directory of Open Access Journals (Sweden)

    Srinivas C

    1991-01-01

    Full Text Available Exposure time to sunlight for photo or photochemotherapy is arbitrarily determined. This could lead to inadequate or over exposure. As a sequence to our initial pilot study on exposure time for PUVASOL, we have now developed a bar chart which could be used as a guide to achieve a more logical and uniform exposure time during different months. We plan to extend the study to different zones in India.

  10. Childhood cancer incidence in relation to sunlight exposure.

    Science.gov (United States)

    Musselman, J R B; Spector, L G

    2011-01-04

    There is increasing interest in the possible association between cancer incidence and vitamin D through its role as a regulator of cell growth and differentiation. Epidemiological studies in adults and one paediatric study suggest an inverse association between sunlight exposure and cancer incidence. We carried out an ecological study using childhood cancer registry data and two population-level surrogates of sunlight exposure, (1) latitude of the registry city or population centroid of the registry nation and (2) annual solar radiation. All models were adjusted for nation-level socioeconomic status using socioeconomic indicators. Latitude and radiation were significantly associated with cancer incidence, and the direction of association was consistent between the surrogates. Findings were not consistent across tumour types. Our ecological study offers some evidence to support an association between sunlight exposure and risk of childhood cancer.

  11. Toxicological impact of cadmium-based quantum dots towards aquatic biota: Effect of natural sunlight exposure

    Energy Technology Data Exchange (ETDEWEB)

    Silva, B.F. [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Andreani, T. [Centro de Investigação em Química da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CITAB − Centre for Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes e Alto Douro, UTAD, Vila Real (Portugal); Gavina, A., E-mail: anacsgavina@gmail.com [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Vieira, M.N. [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Pereira, C.M. [Centro de Investigação em Química da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); Rocha-Santos, T. [Department of Chemistry and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); and others

    2016-07-15

    Highlights: • Under sunlight exposure, all QDs form particle aggregates in the different media. • CdSeS/ZnS QDs showed lower toxic effects to V. fischeri before sunlight exposure. • Sunlight exposure decreased the toxicity of CdS 480 in all organisms. • Sunlight exposure increased the toxicity of CdS 380 QDs for D. magna. • Shell of QDs seemed to make them less harmful to aquatic organisms. - Abstract: Cadmium-based quantum dots (QDs) are increasingly applied in existent and emerging technologies, especially in biological applications due to their exceptional photophysical and functionalization properties. However, they are very toxic compounds due to the high reactive and toxic cadmium core. The present study aimed to determine the toxicity of three different QDs (CdS 380, CdS 480 and CdSeS/ZnS) before and after the exposure of suspensions to sunlight, in order to assess the effect of environmentally relevant irradiation levels in their toxicity, which will act after their release to the environment. Therefore, a battery of ecotoxicological tests was performed with organisms that cover different functional and trophic levels, such as Vibrio fischeri, Raphidocelis subcapitata, Chlorella vulgaris and Daphnia magna. The results showed that core-shell type QDs showed lower toxic effects to V. fischeri in comparison to core type QDs before sunlight exposure. However, after sunlight exposure, there was a decrease of CdS 380 and CdS 480 QD toxicity to bacterium. Also, after sunlight exposure, an effective decrease of CdSeS/ZnS and CdS 480 toxicity for D. magna and R. subcapitata, and an evident increase in CdS 380 QD toxicity, at least for D. magna, were observed. The results of this study suggest that sunlight exposure has an effect in the aggregation and precipitation reactions of larger QDs, causing the degradation of functional groups and formation of larger bulks which may be less prone to photo-oxidation due to their diminished surface area. The same

  12. [Most common skin disorders caused by excessive exposure to sunlight].

    Science.gov (United States)

    Zitás, Éva; Mészáros, Judit

    2016-01-17

    The healing properties of sunlight has been known for millennia, however the gradual deterioration of the ozone layer and the increased use of sun tanning beds in recent decades are causing an increase in skin damaging ultraviolet exposure. In this article the most common photodermatoses and the principles of their treatments are reviewed.

  13. Sunlight Exposure and Vitamin D Status in Breastfed Infants.

    Science.gov (United States)

    Meena, Pinky; Dabas, Aashima; Shah, Dheeraj; Malhotra, Rajeev Kumar; Madhu, S V; Gupta, Piyush

    2017-02-15

    To correlate the sunlight exposure in first 6 months to vitamin D status at 6 months of age in predominantly breastfed infants; and to quantify the sunlight exposure required to achieve serum 25(OH)D level >20 ng/mL, by 6 months of age. Design: Prospective cohort. Tertiary-care hospital predominantly catering to urban poor population in Delhi. 132 healthy infants, delivered at term, and predominantly breastfed were enrolled at 6-8 weeks of age. Of these, 100 infants were available for final evaluation at 6 months of age (mean (SD) follow-up: 126 (17) days). Baseline maternal vitamin D (serum 25(OH)D) levels were obtained at enrolment. The mothers were asked to maintain a daily record of duration of sunlight exposure, timing of exposure, and body surface area exposed, for the infant, on a pre-designed proforma, till the child was 6 months of age. Infant's serum 25(OH)D was measured at 6 months of age. Cumulative Sun Index was calculated as a composite measure of overall duration/time/body surface area exposed to sunlight; and correlated with the infant serum 25(OH)D after adjusting for baseline maternal serum 25(OH)D levels, season of exposure, and skin color of the infant. Sun index for exposure in morning (before 10 am) and afternoon (10 am-3 pm) were also correlated to vitamin D status. Of 100 mother-infant pairs completing the study, 90 mothers had vitamin D deficiency (serum 25(OH)D exposure of infants to sunlight was 17 min per week, on 6% of body surface area. Vitamin D levels of 67 (67%) infants at 6 months were less than 12 ng/mL and another 23% had insufficient levels (12-20 ng/mL). Cumulative sun index correlated positively to infant's serum 25(OH)D level at 6 months of age (r= 0.461, Psunlight exposure, between 10 am and 3 pm, over 40% body area (infant clothed in diapers, in prone position) for at least 16 weeks, was estimated requirement to achieve sufficient vitamin D levels (>20 ng/mL) by 6 months of age. There is a significant positive correlation

  14. Lack of sunlight exposure influence on primary glioblastoma survival.

    Science.gov (United States)

    Mutlu, Hasan; Akca, Zeki; Erden, Abdulsamet; Aslan, Tuncay; Ucar, Kadir; Kaplan, Bunyamin; Buyukcelik, Abdullah

    2014-01-01

    The prognosis of primary glioblastoma (GBM) is poor. Approximately 2/3 of primary brain tumor diagnoses are GBM, of which 95% are primary lesions. In this study, we aimed to evaluate whether more sunlight exposure has an effect on survival of patients with primary GBM. A total of 111 patients with primary GBM were enrolled from Kayseri in inner Anatolia which has a cold climate (n: 40) and Mersin in Mediterranean region with a warm climate and more sunlight exposure (n: 71). The patients with primary GBM were divided into two groups as Kayseri and Mersin and compared for progression free survival (PFS) and overall survival (OS). The PFS values were 7.0 and 4.7 months for Kayseri and Mersin groups, respectively (p=0.10) and the respective OS values were 13.3 and 9.4 months (p=0.13). We did not found any significant difference regarding age, sex, comorbidity, smoking, surgery, resurgery, adjuvant chemoradiotherapy and palliative chemotherapy between the groups. We found that more sunlight exposure had no impact on prognosis of patients with primary GBM, adding inconsistency to the literature about the relationship between sunlight and GBM.

  15. PRKCZ methylation is associated with sunlight exposure in a North American but not a Mediterranean population.

    Science.gov (United States)

    Aslibekyan, Stella; Dashti, Hassan S; Tanaka, Toshiko; Sha, Jin; Ferrucci, Luigi; Zhi, Degui; Bandinelli, Stefania; Borecki, Ingrid B; Absher, Devin M; Arnett, Donna K; Ordovas, Jose M

    2014-11-01

    Sunlight exposure has been shown to alter DNA methylation patterns across several human cell-types, including T-lymphocytes. Since epigenetic changes establish gene expression profiles, changes in DNA methylation induced by sunlight exposure warrant investigation. The purpose of this study was to assess the effects of sunlight exposure on CD4+ T-cell methylation patterns on an epigenome-wide scale in a North American population of European origin (n=991). In addition, we investigated the genetic contribution to epigenetic variation (methylQTL). We used linear regression to test the associations between methylation scores at 461,281 cytosine-phosphate-guanine (CpG) sites and sunlight exposure, followed by a genome-wide association analysis (methylQTL) to test for associations between methylation at the top CpG locus and common genetic variants, assuming an additive genetic model. We observed an epigenome-wide significant association between sunlight exposure and methylation status at cg26930596 (p=9.2×10(-8)), a CpG site located in protein kinase C zeta (PRKCZ), a gene previously shown to be entrained by light. MethylQTL analysis resulted in significant associations between cg26930596 and two intergenic single nucleotide polymorphisms on chromosome 3, rs4574216 (p=1.5×10(-10)) and rs4405858 (p=1.9×10(-9)). These common genetic variants reside downstream of WWTR1, a transcriptional co-activator of PRKCZ. Associations observed in the North American population, however, did not replicate in an independent Mediterranean cohort. Our preliminary results support the role of sunlight exposure in epigenetic processes, and lay the groundwork for future studies of the molecular link between sunlight and physiologic processes such as tumorigenesis and metabolism.

  16. Toxicological impact of cadmium-based quantum dots towards aquatic biota: Effect of natural sunlight exposure.

    Science.gov (United States)

    Silva, B F; Andreani, T; Gavina, A; Vieira, M N; Pereira, C M; Rocha-Santos, T; Pereira, R

    2016-07-01

    Cadmium-based quantum dots (QDs) are increasingly applied in existent and emerging technologies, especially in biological applications due to their exceptional photophysical and functionalization properties. However, they are very toxic compounds due to the high reactive and toxic cadmium core. The present study aimed to determine the toxicity of three different QDs (CdS 380, CdS 480 and CdSeS/ZnS) before and after the exposure of suspensions to sunlight, in order to assess the effect of environmentally relevant irradiation levels in their toxicity, which will act after their release to the environment. Therefore, a battery of ecotoxicological tests was performed with organisms that cover different functional and trophic levels, such as Vibrio fischeri, Raphidocelis subcapitata, Chlorella vulgaris and Daphnia magna. The results showed that core-shell type QDs showed lower toxic effects to V. fischeri in comparison to core type QDs before sunlight exposure. However, after sunlight exposure, there was a decrease of CdS 380 and CdS 480 QD toxicity to bacterium. Also, after sunlight exposure, an effective decrease of CdSeS/ZnS and CdS 480 toxicity for D. magna and R. subcapitata, and an evident increase in CdS 380 QD toxicity, at least for D. magna, were observed. The results of this study suggest that sunlight exposure has an effect in the aggregation and precipitation reactions of larger QDs, causing the degradation of functional groups and formation of larger bulks which may be less prone to photo-oxidation due to their diminished surface area. The same aggregation behaviour after sunlight exposure was observed for bare QDs. These results further emphasize that the shell of QDs seems to make them less harmful to aquatic biota, both under standard environmental conditions and after the exposure to a relevant abiotic factor like sunlight. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Sunlight Exposure and Breast Density: A Population-Based Study

    Science.gov (United States)

    Wu, Sheng-Hui; So, Edwin; Lam, Tsz-ping; Woo, Jean; Yuen, PY; Qin, Ling; Ku, Susanna

    2013-01-01

    Purpose This study aims to assess the association of sunlight exposure with breast cancer risk, measured by the breast density assessed from Tabár's mammographic pattern in Chinese women. Methods A total of 676 premenopausal women were recruited to participate in this study, in which 650 completed a validated sunlight exposure questionnaire via telephone. The mammograms were classified according to Tabár's classification for parenchyma, and patterns IV & V and I, II & III indicated respectively high and low risk mammographic patterns for breast cancer. The odds ratios (OR) and 95% confidence intervals (CIs) for sun exposure-related variables were estimated using unconditional logistic regression with adjustment for potential confounders. Results Among 646 participants, women with high breast cancer risk (Tabár's patterns IV &V) had less hours spent in the sun than those with low risk (I, II & III) at any age stage. A higher level of sunlight exposure was associated with a significantly lower risk having high risk Tabár's pattern. Women aged 40 to 44 years who were in the highest tertile of lifetime total hours spent in the sun had a multi-adjusted OR of 0.41 (95% CI, 0.18-0.92; p for trend=0.03) compared with those in the lowest tertile (>2.19 hr/day vs. sunlight exposure is related to a lower risk of having high risk breast density pattern in premenopausal women. Our results also suggest the most relevant period of exposure is during earlier life. PMID:23843849

  18. Vitamin D and Sunlight Exposure in Newly-Diagnosed Parkinson's Disease

    National Research Council Canada - National Science Library

    Wang, Juan; Yang, Deyu; Yu, Yu; Shao, Gaohai; Wang, Qunbo

    2016-01-01

    ...), while the effects of sunlight exposure have not yet been fully investigated. Therefore, we evaluated the associations between serum vitamin D, vitamin D intake, sunlight exposure, and newly-diagnosed PD patients in a Chinese population...

  19. Effect of sunlight exposure on serum 25-hydroxyvitamin d concentration in women with vitamin d deficiency: using ambulatory lux meter and sunlight exposure questionnaire.

    Science.gov (United States)

    Lee, Sang-Hoon; Park, Soo-Jung; Kim, Kwang-Min; Lee, Duck-Joo; Kim, Woo-Jae; Park, Rae-Woong; Joo, Nam-Seok

    2012-11-01

    Vitamin D is an important factor in human health. Yet, vitamin D deficiency is very common. We aimed to confirm serum 25-hydroxyvitamin D (25OHD) concentration change after sunlight exposure and to elucidate the relationship between the amount of sunlight exposure and serum 25OHD level change by ambulatory lux meter and sunlight exposure questionnaire. Twenty healthy young women were enrolled. They were educated to obtain 20 minutes of sunlight exposure during weekdays from October to November, 2010, during which they were to wear an ambulatory lux meter on an arm. All subjects completed a one-week recall sunlight exposure questionnaire at the end of the study. Before and after sunlight exposure, serum 25OHD level was measured. Mean pre-exposure serum 25OHD concentration was 11.01 ng/mL. The mean change of pre- and post-exposure 25OHD level was -0.62 ng/mL, but it was not statistically significant. The mean personal sunlight exposure recorded by ambulatory lux meter, 292.6 lux/s, showed no significant relationship with average change of 25OHD and average weekly sunlight exposure score, 11.9, calculated by the sunlight exposure questionnaire. However, the mean change of serum 25OHD level and weekly sunlight exposure score showed significant negative correlation (r = -0.469, P = 0.037). Change of serum 25OHD concentration after four weeks of sunlight exposure was not statistically significant in women with vitamin D deficiency. However, serum 25OHD concentration change was significantly negatively correlated with the sunlight exposure score by the questionnaire.

  20. Can Skin Exposure to Sunlight Prevent Liver Inflammation?

    Directory of Open Access Journals (Sweden)

    Shelley Gorman

    2015-05-01

    Full Text Available Liver inflammation contributes towards the pathology of non-alcoholic fatty liver disease (NAFLD. Here we discuss how skin exposure to sunlight may suppress liver inflammation and the severity of NAFLD. Following exposure to sunlight-derived ultraviolet radiation (UVR, the skin releases anti-inflammatory mediators such as vitamin D and nitric oxide. Animal modeling studies suggest that exposure to UVR can prevent the development of NAFLD. Association studies also support a negative link between circulating 25-hydroxyvitamin D and NAFLD incidence or severity. Clinical trials are in their infancy and are yet to demonstrate a clear beneficial effect of vitamin D supplementation. There are a number of potentially interdependent mechanisms whereby vitamin D could dampen liver inflammation, by inhibiting hepatocyte apoptosis and liver fibrosis, modulating the gut microbiome and through altered production and transport of bile acids. While there has been a focus on vitamin D, other mediators induced by sun exposure, such as nitric oxide may also play important roles in curtailing liver inflammation.

  1. Can skin exposure to sunlight prevent liver inflammation?

    Science.gov (United States)

    Gorman, Shelley; Black, Lucinda J; Feelisch, Martin; Hart, Prue H; Weller, Richard

    2015-05-05

    Liver inflammation contributes towards the pathology of non-alcoholic fatty liver disease (NAFLD). Here we discuss how skin exposure to sunlight may suppress liver inflammation and the severity of NAFLD. Following exposure to sunlight-derived ultraviolet radiation (UVR), the skin releases anti-inflammatory mediators such as vitamin D and nitric oxide. Animal modeling studies suggest that exposure to UVR can prevent the development of NAFLD. Association studies also support a negative link between circulating 25-hydroxyvitamin D and NAFLD incidence or severity. Clinical trials are in their infancy and are yet to demonstrate a clear beneficial effect of vitamin D supplementation. There are a number of potentially interdependent mechanisms whereby vitamin D could dampen liver inflammation, by inhibiting hepatocyte apoptosis and liver fibrosis, modulating the gut microbiome and through altered production and transport of bile acids. While there has been a focus on vitamin D, other mediators induced by sun exposure, such as nitric oxide may also play important roles in curtailing liver inflammation.

  2. Occupational Sunlight Exposure and Risk of Renal Cell Carcinoma

    Science.gov (United States)

    Karami, Sara; Boffetta, Paolo; Stewart, Patricia; Rothman, Nathaniel; Hunting, Katherine L.; Dosemeci, Mustafa; Berndt, Sonja I.; Brennan, Paul; Chow, Wong-Ho; Moore, Lee E.; Zaridze, David; Mukeria, Anush; Janout, Vladimir; Kollarova, Helena; Bencko, Vladimir; Holcatova, Ivana; Navritalova, Marie; Szeszenia-Dabrowska, Neonila; Mates, Dana; Gromiec, Jan P.

    2010-01-01

    Background Recent findings indicate that vitamin D obtained from ultraviolet (UV) exposure may reduce the risk of a number of different cancers. Vitamin D is metabolized to its active form within the kidney, the major organ for vitamin D metabolism and activity. Since both the incidence of renal cell cancer and prevalence of vitamin D deficiency have increased over the past few decades, this study sought to explore whether occupational UV exposure was associated with renal cell carcinoma (RCC) risk. Methods A hospital-based case-control study of 1,097 RCC cases and 1,476 controls was conducted in four Central and Eastern European countries. Demographic and occupational information was collected to examine the association between occupational UV exposure and RCC risk. Results A significant (24%-38%) reduction in RCC risk was observed with increasing occupational UV exposure among male participants. No association between UV exposure and RCC risk was observed among female participants. When analyses were stratified by latitude as another estimate of sunlight intensity, a stronger (71%-73%) reduction in RCC risk was observed between UV exposure and cancer risk among males residing at the highest latitudes. Conclusion The results of this study suggest that among males there is an inverse association between occupational UV exposure and renal cancer risk. Replication studies are warranted to confirm these results. PMID:20213683

  3. Effect of Sunlight Exposure on Bone Mineral Density in Children with Severe Disability.

    Science.gov (United States)

    Kanemura, Hideaki; Hatakeyama, Kazuo; Sano, Fumikazu; Yagasaki, Hideaki; Sugita, Kanji; Aihara, Masao

    2016-08-01

    The aim of this study was to determine the efficacy of sunlight exposure for increasing bone mineral density (BMD) in children with severe disability. The subjects were five children with severe disability, aged 6 to 8 years. BMD was measured at baseline and after 3, 6, 9, and 12 months of starting sunlight exposure. All caregivers of patients were instructed to create opportunities to stay outdoors. Daily sunlight exposure time was defined as hours of staying outdoors. Mean hours of sunbathing per day were calculated at baseline and after 3, 6, 9, and 12 months of starting sunlight exposure. Sunlight exposure tended to be longer after starting than before starting in all patients, but the difference was not significant (p = 0.052). Along with the increase in sunlight exposure, BMD increased significantly after the start of sunlight exposure in all patients (p sunlight exposure. No patients had bone fractures after the start of sunlight exposure. These results suggest that sunlight exposure increased BMD, and that this may reduce the risk of bone fracture in children with disability. Georg Thieme Verlag KG Stuttgart · New York.

  4. Sunlight Exposure, Pigmentation, and Incident Age-Related Macular Degeneration

    Science.gov (United States)

    Klein, Barbara E. K.; Howard, Kerri P.; Iyengar, Sudha K.; Sivakumaran, Theru A.; Meyers, Kristin J.; Cruickshanks, Karen J.; Klein, Ronald

    2014-01-01

    Purpose. Examine potential effects of sunlight exposure, hair color, eye color, and selected gene single-nucleotide polymorphisms (SNPs) on incidence of AMD. Methods. Subjects participated in up to five examinations over a 20-year period. Eye color, self-reported hair color as a teenager, and sunlight exposure were ascertained at the baseline examination. Presence and severity of AMD and its lesions were determined via fundus photographs. Genetic data were available on a subset of participants. The SNPs CFH Y402H rs1061170 and ARMS2 A69S rs10490924 were used to analyze genetic risk of AMD; OCA2 rs4778241 and HERC2 rs12913832 represented genetic determinants of eye color. Results. Incidence of early AMD was higher in blond/red-haired persons compared with brown/black-haired persons (hazard ratio [HR] 1.25, P = 0.02) and in persons with high sun exposure in their thirties (HR 1.41, P = 0.02). However, neither was significant after adjustment for multiple comparisons. Eye (HR 1.36, P = 0.006) and hair color (HR 1.42, P = 0.003) were associated with incidence of any retinal pigmentary abnormalities (RPAs). Both remained significant after adjustment for multiple comparisons. Neither presence of alleles for light-colored eyes nor those associated with high risk of late AMD altered the association of eye or hair color with early AMD. None of the characteristics studied were significantly associated with late AMD. Conclusions. Modest associations of eye color, hair color, and HERC2 genotype with any RPAs were found. Genes for AMD did not affect these associations. Eye color phenotype was more strongly associated with outcomes than HERC2 or OCA2 genotype. PMID:25125603

  5. Sunlight exposure, pigmentation, and incident age-related macular degeneration.

    Science.gov (United States)

    Klein, Barbara E K; Howard, Kerri P; Iyengar, Sudha K; Sivakumaran, Theru A; Meyers, Kristin J; Cruickshanks, Karen J; Klein, Ronald

    2014-08-14

    Examine potential effects of sunlight exposure, hair color, eye color, and selected gene single-nucleotide polymorphisms (SNPs) on incidence of AMD. Subjects participated in up to five examinations over a 20-year period. Eye color, self-reported hair color as a teenager, and sunlight exposure were ascertained at the baseline examination. Presence and severity of AMD and its lesions were determined via fundus photographs. Genetic data were available on a subset of participants. The SNPs CFH Y402H rs1061170 and ARMS2 A69S rs10490924 were used to analyze genetic risk of AMD; OCA2 rs4778241 and HERC2 rs12913832 represented genetic determinants of eye color. Incidence of early AMD was higher in blond/red-haired persons compared with brown/black-haired persons (hazard ratio [HR] 1.25, P = 0.02) and in persons with high sun exposure in their thirties (HR 1.41, P = 0.02). However, neither was significant after adjustment for multiple comparisons. Eye (HR 1.36, P = 0.006) and hair color (HR 1.42, P = 0.003) were associated with incidence of any retinal pigmentary abnormalities (RPAs). Both remained significant after adjustment for multiple comparisons. Neither presence of alleles for light-colored eyes nor those associated with high risk of late AMD altered the association of eye or hair color with early AMD. None of the characteristics studied were significantly associated with late AMD. Modest associations of eye color, hair color, and HERC2 genotype with any RPAs were found. Genes for AMD did not affect these associations. Eye color phenotype was more strongly associated with outcomes than HERC2 or OCA2 genotype. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  6. Low exposure to sunlight is a risk factor for Crohn's disease.

    Science.gov (United States)

    Nerich, V; Jantchou, P; Boutron-Ruault, M-C; Monnet, E; Weill, A; Vanbockstael, V; Auleley, G-R; Balaire, C; Dubost, P; Rican, S; Allemand, H; Carbonnel, F

    2011-04-01

    Low sunshine exposure might contribute to the pathogenesis of inflammatory bowel disease (IBD). To assess the geographic distribution of IBD incidence in relation to sunshine exposure in France to test the hypothesis that higher sun exposure is associated with lower IBD risk. Using the national health insurance database, incidence rates of Crohn's disease (CD) and ulcerative colitis (UC) were estimated for each of the 94 French administrative areas ('départements'), between 2000 and 2002. The surface UV radiation intensity was obtained by combining modelling and satellite data from Meteosat, the European meteorological satellite. Relationships between incidence rates and sun exposure were tested for significance by using a Poisson regression. We mapped smoothed relative risks (sRR) for CD and UC, using a Bayesian approach and adjusting for sun exposure, to search for geographical variations. Areas with a smoothed RR of CD incidence significantly above 1 corresponded to areas with low sunshine exposure, whereas those with high or medium sunlight exposure had smoothed RRs either lower than 1 or not significantly different from 1. There was no association between sun exposure and UC incidence. This geographic study suggests that low sunlight exposure is associated with an increased incidence of Crohn's disease. Further studies are needed to determine if this association is causal. © 2011 Blackwell Publishing Ltd.

  7. Does sunlight exposure improve survival in patients with non-small cell lung cancer?

    Science.gov (United States)

    Mutlu, Hasan; Buyukcelik, Abdullah; Aksahin, Arzu; Kibar, Mustafa; Cihan, Yasemin Benderli; Kaya, Eser; Seyrek, Ertugrul; Yavuz, Sinan; Erden, Abdulsamet; Calikusu, Zuleyha; Aslan, Tuncay; Akca, Zeki

    2013-01-01

    Some epidemiological studies reported that sunlight exposure and highvitamin D levels may decrease the morbidity and mortality related to cancer. We aimed to evaluate whether sunlight exposure has an impact on survival in patients with non small cell lung cancer. A total of 546 patients with NSCLC from two different regions (Kayseri and Adana) differing according to sunlight exposure were analysed retrospectively. The median overall survival (OS) rates were 11. 6 (CI: 9.50-13.6) and 15.6 months (CI: 12.4-18.8) for Kayseri and Adana, respectively, in all patients (p=0.880). There were no differences between groups in terms of OS. While there is strong evidence regarding inverse relationship between cancer incidence and sunlight exposure, it is still controversial whether sunlight exposure is a good prognostic factor for survival in patients with lung cancer.

  8. Serum 25-hydroxyvitamin-D responses to multiple UV exposures from solaria: inferences for exposure to sunlight.

    Science.gov (United States)

    McKenzie, Richard; Scragg, Robert; Liley, Ben; Johnston, Paul; Wishart, John; Stewart, Alistair; Prematunga, Roshani

    2012-07-01

    We investigate the relationship between blood serum 25-hydroxyvitamin D (25(OH)D) and UV exposure from two artificial sources. We then use the results to test the validity of the action spectrum for vitamin D production, and to infer the production from summer and winter sunlight. The results are based on a two-arm randomised clinical trial of biweekly UV exposure for 12 weeks using two different types of dermatological booths: one emitting primarily UV-A radiation, and the other emitting primarily UV-B radiation (booth A and booth B respectively). In terms of the vitamin D production per unit erythema, one of the booths mimics summer noon sunlight, while the other mimics winter noon sunlight. Blood samples were taken before and after the exposures. For all participants, the phototherapy booth treatments arrested the usual wintertime decline in 25(OH)D, and for most the treatments from either booth resulted in significant increases. The increases were highly non-linear and there was a high degree of variability in 25(OH)D and its response to UV from person to person. By the end of the 12 week period, the mean increase was >30 nmol l(-1) from a cumulative exposure of 17 SED from the UV-A booth, and twice that for the UV-B booth for which the cumulative exposure was 268 SED. Assuming a logarithmic relationship between UV and vitamin D, the results for the two booths show no obvious inconsistency in the action spectrum for pre-vitamin D production. However, further measurements with similar exposures from each booth are required to confirm its validity. A model was developed to describe the increases in serum 25(OH)D resulting from the UV exposures, which differed markedly between the two booths. The deduced initial rate of increase of 25(OH)D was approximately 5 nmol l(-1) per SED. From the large increases in 25(OH)D from each booth, along with knowledge of the spectral distribution of sunlight and assuming the currently-accepted action spectrum for photo

  9. Vitamin D and Sunlight Exposure in Newly-Diagnosed Parkinson's Disease.

    Science.gov (United States)

    Wang, Juan; Yang, Deyu; Yu, Yu; Shao, Gaohai; Wang, Qunbo

    2016-03-04

    Circulating vitamin D has previously been found to be lower in patients with Parkinson's disease (PD), while the effects of sunlight exposure have not yet been fully investigated. Therefore, we evaluated the associations between serum vitamin D, vitamin D intake, sunlight exposure, and newly-diagnosed PD patients in a Chinese population. This case-control study measured serum 25-hydroxyvitamin D (25(OH)D) levels and sunlight exposure in 201 patients with newly-diagnosed PD and 199 controls without neurodegenerative diseases. Data on vitamin D intake and sunlight exposure were obtained using a self-report questionnaire. Multivariable logistic regressions were employed to evaluate the associations between serum 25(OH)D levels, sunlight exposure, and PD. Adjustments were made for sex, age, smoking, alcohol use, education, BMI, and vitamin D intake. There were significantly lower levels of serum 25(OH)D (20.6 ± 6.5 ng/mL), daily vitamin D intake (8.3 ± 3.7 g/day), and sunlight exposure (9.7 ± 4.1 h/week) in patients with PD compared to healthy controls (p sunlight exposure were 1 (reference), 0.809 (0.454, 1.443), 0.623 (0.345, 1.124) and 0.533 (0.294, 0.966), respectively. A significant positive correlation between serum 25(OH)D and sunlight exposure was found, but serum 25(OH)D was not correlated with daily vitamin D intake. This study indicates that lower levels of serum 25(OH)D and sunlight exposure are significantly associated with an increased risk for PD.

  10. Vitamin D and Sunlight Exposure in Newly-Diagnosed Parkinson’s Disease

    Science.gov (United States)

    Wang, Juan; Yang, Deyu; Yu, Yu; Shao, Gaohai; Wang, Qunbo

    2016-01-01

    Circulating vitamin D has previously been found to be lower in patients with Parkinson’s disease (PD), while the effects of sunlight exposure have not yet been fully investigated. Therefore, we evaluated the associations between serum vitamin D, vitamin D intake, sunlight exposure, and newly-diagnosed PD patients in a Chinese population. This case-control study measured serum 25-hydroxyvitamin D (25(OH)D) levels and sunlight exposure in 201 patients with newly-diagnosed PD and 199 controls without neurodegenerative diseases. Data on vitamin D intake and sunlight exposure were obtained using a self-report questionnaire. Multivariable logistic regressions were employed to evaluate the associations between serum 25(OH)D levels, sunlight exposure, and PD. Adjustments were made for sex, age, smoking, alcohol use, education, BMI, and vitamin D intake. There were significantly lower levels of serum 25(OH)D (20.6 ± 6.5 ng/mL), daily vitamin D intake (8.3 ± 3.7 g/day), and sunlight exposure (9.7 ± 4.1 h/week) in patients with PD compared to healthy controls (p sunlight exposure were 1 (reference), 0.809 (0.454, 1.443), 0.623 (0.345, 1.124) and 0.533 (0.294, 0.966), respectively. A significant positive correlation between serum 25(OH)D and sunlight exposure was found, but serum 25(OH)D was not correlated with daily vitamin D intake. This study indicates that lower levels of serum 25(OH)D and sunlight exposure are significantly associated with an increased risk for PD. PMID:26959053

  11. Sunlight exposure and sun sensitivity associated with disability progression in multiple sclerosis

    NARCIS (Netherlands)

    D'hooghe, M. B.; Haentjens, P.; Nagels, G.; Garmyn, M.; De Keyser, J.

    2012-01-01

    Background: Sunlight and vitamin D have been inversely associated with the risk of multiple sclerosis (MS). Objective: We investigated sunlight exposure and sun sensitivity in relation to disability progression in MS. Methods: We conducted a survey among persons with MS, registered by the Flemish MS

  12. Sunlight Exposure, Work Hours, Caffeine Consumption, and Sleep Duration in the Naval Environment.

    Science.gov (United States)

    Shattuck, Nita L; Matsangas, Panagiotis

    2017-06-01

    Sailors in the U.S. Navy are habitual shiftworkers, often experiencing circadian misalignment due to their irregular work/rest schedules. This study assessed the effect of sunlight exposure, work hours, and caffeinated beverage consumption on the daily sleep duration of crewmembers of a U.S. Navy ship during a 2-wk underway period. Working in an artificially lit area with no access to sunlight during work hours, U.S. Navy crew members (N = 91) used daily logs to report their daily activity, caffeinated beverage consumption, and exposure to sunlight while off-duty; sleep was assessed by wrist-worn actigraphy. Hours of sunlight exposure, work duration, and the amount of coffee/tea/soft drinks were statistically significant predictors of sleep duration. On average, crewmembers who reported more than one half-hour of sunlight each day slept on average ∼40 min (10%) less than their peers working the same shifts who received less than one half-hour of sunlight (on average 6.05 ± 0.90 h vs. 6.71 ± 0.91 h, respectively). Exposure to sunlight, work hours, and consumption of caffeinated beverages are important factors when planning watchstanding schedules at sea. Even though further research is needed, our results suggest that even brief exposure to sunlight may contribute to circadian misalignment that negatively affects sleep in the operational environment. Educating crewmembers about sleep hygiene, especially the important roles played by sunlight and caffeine, could potentially improve the sleep and fatigue levels of this population of maritime shiftworkers.Shattuck NL, Matsangas P. Sunlight exposure, work hours, caffeine consumption, and sleep duration in the naval environment. Aerosp Med Hum Perform. 2017; 88(6):579-585.

  13. [Progress in research of association between myopia and sunlight exposure in children].

    Science.gov (United States)

    Zhai, L L; Wu, X Y; Xu, S J; Tao, F B

    2016-11-10

    Myopia has become a major health problem on global scale due to its increasing high prevalence in the past few decades and gradual younger onset age. Accumulated epidemiological surveys have shown that decreased time of exposure to sunlight would be an inducement for the development of myopia. Increasing time spent outdoors and exposure to sunlight might be the most cost-effective and effective measure for children to prevent myopia. This paper summarizes the progress in research of the association between sunlight exposure and myopia in children and its mechanisms to provide new clues for the research on myopia prevention and control.

  14. The ability of periorbitally applied antiglare products to improve contrast sensitivity in conditions of sunlight exposure.

    Science.gov (United States)

    DeBroff, Brian M; Pahk, Patricia J

    2003-07-01

    Sun glare decreases athletes' contrast sensitivity and impairs their ability to distinguish objects from background. Many commercial products claim to reduce glare but have not been proven effective in clinical studies. To determine whether glare-reducing products such as eye black grease and antiglare stickers reduce glare and improve contrast sensitivity during sunlight exposure. We tested 46 subjects for contrast sensitivity using a Pelli-Robson contrast chart. Each subject served as an internal control and then was randomized to either application of eye black grease, antiglare stickers, or petroleum jelly at the infraorbital rim. All testing was performed in conditions of unobstructed sunlight. Analysis of variance revealed a significant difference between eye black grease (mean +/- SD, Pelli-Robson value, 1.87 +/- 0.09 logMAR units) and antiglare stickers (1.75 +/- 0.14 logMAR units) in binocular testing (P =.02). No statistical difference was found between the groups in right eyes, left eyes, or in combined data from the right and left eyes. Paired t tests demonstrated a significant difference between control (mean +/- SD, 1.77 +/- 0.14 logMAR units) and eye black grease (1.87 +/- 0.09 logMAR units) in binocular testing (P =.04). There was also a significant difference between control (mean +/- SD, 1.65 +/- 0.05 logMAR units) and eye black grease (1.67 +/- 0.06 logMAR units) in combined data from the right and left eyes (P =.02). Eye black grease reduces glare and improves contrast sensitivity in conditions of sunlight exposure compared with the control and antiglare stickers in binocular testing.

  15. Amelioration of osteoporosis and hypovitaminosis D by sunlight exposure in Parkinson's disease.

    Science.gov (United States)

    Sato, Yoshihiro; Iwamoto, Jun; Honda, Yoshiaki

    2011-01-01

    A high incidence of fractures, particularly of the hip, represents an important problem in patients with Parkinson's disease (PD), who are prone to falls and have osteoporosis. We previously showed that 25-hydroxyvitamin D (25-OHD) deficiency due to sunlight deprivation with compensatory hyperparathyroidism causes reduced bone mineral density (BMD) in elderly patients with PD. The present study was undertaken to address the possibility that sunlight exposure may maintain BMD and reduce the incidence of hip fracture in elderly patients with PD. In a prospective study, PD patients were assigned to regular sunlight exposure (n=162) or usual lifestyle (n=162), and followed for 2 years. BMD of the second metacarpal bone was measured using a computed X-ray densitometer. Incidence of hip fracture in the two patient groups during the 2 year follow-up period was assessed. At baseline, patients of both groups showed vitamin D deficiency due to sunlight deprivation with compensatory hyperparathyroidism. The exposed group patients were exposed to sunlight (3231 min/year). BMD increased by 3.8% in the sunlight-exposed group and decreased by 2.6% in the usual lifestyle group (psunlight-exposed group. Eleven patients sustained hip fracture in the normal lifestyle group, and 3 fractures occurred among the sunlight-exposed group (p=.03; odds ratio=2.4). Sunlight exposure can increase the BMD of vitamin D deficient bone by increasing 25-OHD concentration and leads to the prevention of hip fracture. © 2010 Elsevier Ltd. All rights reserved.

  16. Formation of DNA strand breaks in peripheral lymphocytes of rats after exposure to natural sunlight.

    Science.gov (United States)

    Rodrigues-Junior, Dorival Mendes; Melo, Ana Amélia de Carvalho; da Silva, Benedito Borges; Lopes-Costa, Pedro Vitor

    2012-04-01

    This paper aims to evaluate the genotoxicity in peripheral blood lymphocytes of rats after exposure to sunlight at different time points of day in a tropical region of Brazil (5 degrees S, 42 degrees W). Thirty Wistar-Hannover rats, three months old, were randomly divided into three groups of 10 animals each: Group I [control, without exposure to ultraviolet (UV) radiation], Group II (exposed to sunlight during 08:00 a.m. to 10:00 a.m.), and Group III (exposed to sunlight during 10:00 a.m. to 12:00 a.m.). After a week of exposure, peripheral blood samples were taken from the tail of these animals to prepare smears on two slides per animal. In 24 h after exposure to sunlight in Group III, a new collection was obtained to observe the repair activity. The alkaline comet assay was used in this study to evaluate the genotoxic activity of sunlight (P exposure to sunlight in Group III showed genotoxic action in comparison to the other groups (P sunlight (UVA-B) in lymphocytes of mammals from 10:00 a.m. to 12:00 a.m., due to a higher intensity of UV in this tropical region.

  17. Is casual exposure to summer sunlight effective at maintaining adequate vitamin D status?

    Science.gov (United States)

    Diffey, Brian L

    2010-08-01

    The advice that an adequate vitamin D status can be achieved by short, casual exposure to summer sunlight is ubiquitous. This review will examine the value of this advice. The results of experimental studies on changes in serum 25-hydroxyvitamin D [25(OH)D] concentrations following ultraviolet exposure are interpreted in the context of human exposure to sunlight. It is shown that current advice about modest sun exposure during the summer months does little in the way of boosting overall 25(OH)D levels, while sufficient sun exposure that could achieve a worthwhile benefit would compromise skin health. Failure to understand the nature of human exposure to sunlight has led to misguided advice concerning the sun exposure necessary for an adequate vitamin D status.

  18. Water balance of goats in Jeneponto - South Sulawesi under sunlight exposure and water restriction

    Directory of Open Access Journals (Sweden)

    Djoni Prawira Rahardja

    2007-10-01

    Full Text Available Water balance of 5 does of Kacang goat of Jeneponto was studied under the condition of sunlight exposure and water restriction. The study was conducted in dry season with 4 consecutive treatments of 10 d with 4-5 d of adjustment period between two consecutive treatments: (1 indoor and unrestricted water; (2 indoor and restricted water; (3 10 h outdoor–and unrestricted water; (4 10 h outdoor – restricted water. The maximum air temperature of outdoor was 39.3OC, and it was 30OC in the indoor environment. In all treatments, the animals were placed in the individual crates. The plasma volume of the goats was higher under sunlight exposure, but it decreased by water restriction, while hematocrite value indicated a reverse responses. Sunlight exposure did not significantly decrease the intake and digestion of organic matter, but water restriction affected significantly and this effect was higher under sunlight exposre. The proportions of water loss through every avenue were maintained relatively constant either under water restriction or sunlight exposure in which the respration rate increased significantly. The findings suggest that sunlight exposure with unrestricted water resulted in a positive water balance without a significant change in organic matter intake and utilization. Water restriction resulted in a negative water balance, reducing organic matter intake and utilization. As the adaptive mechanisms, the goat appeared to be able to withstand in the harsh environment of Jeneponto by expanding plasma volume, increasing body temperature and respiration rate.

  19. Effects of sunlight exposure on grapevine powdery mildew development.

    Science.gov (United States)

    Austin, Craig N; Wilcox, Wayne F

    2012-09-01

    Natural and artificially induced shade increased grapevine powdery mildew (Erysiphe necator) severity in the vineyard, with foliar disease severity 49 to 75% higher relative to leaves in full sun, depending on the level of natural shading experienced and the individual experiment. Cluster disease severities increased by 20 to 40% relative to those on check vines when ultraviolet (UV) radiation was filtered from sunlight reaching vines in artificial shading experiments. Surface temperatures of leaves in full sunlight averaged 5 to 8°C higher than those in natural shade, and in one experiment, filtering 80% of all wavelengths of solar radiation, including longer wavelengths responsible for heating irradiated tissues, increased disease more than filtering UV alone. In controlled environment experiments, UV-B radiation reduced germination of E. necator conidia and inhibited both colony establishment (hyphal formation and elongation) and maturity (latent period). Inhibitory effects of UV-B radiation were significantly greater at 30°C than at 20 or 25°C. Thus, sunlight appears to inhibit powdery mildew development through at least two mechanisms, i.e., (i) UV radiation's damaging effects on exposed conidia and thalli of the pathogen; and (ii) elevating temperatures of irradiated tissues to a level supraoptimal or inhibitory for pathogen development. Furthermore, these effects are synergistic at temperatures near the upper threshold for disease development.

  20. HISTORY OF SUNLIGHT EXPOSURE IS A RISK FACTOR FOR AGE-RELATED MACULAR DEGENERATION.

    Science.gov (United States)

    Schick, Tina; Ersoy, Lebriz; Lechanteur, Yara T E; Saksens, Nicole T M; Hoyng, Carel B; den Hollander, Anneke I; Kirchhof, Bernd; Fauser, Sascha

    2016-04-01

    To evaluate effects of current and past sunlight exposure and iris color on early and late age-related macular degeneration (AMD). Of 3,701 individuals from the EUGENDA database, 752 (20.3%) showed early AMD, 1,179 (31.9%) late AMD, and 1,770 (47.8%) were controls. Information about current and past sunlight exposure, former occupation type, subdivided in indoor working and outdoor working, and iris color were obtained by standardized interviewer-assisted questionnaires. Associations between environmental factors adjusted for age, gender, and smoking and early and late AMD were performed by multivariate regression analysis. Current sunlight exposure showed no association with early AMD or late AMD, but past sunlight exposure (≥8 hours outside daily) was significantly associated with early AMD (odds ratio: 5.54, 95% confidence interval 1.25-24.58, P = 0.02) and late AMD (odds ratio: 2.77, 95% confidence interval 1.25-6.16, P = 0.01). Outside working was found to be associated with late AMD (odds ratio: 2.57, 95% confidence interval 1.89-3.48, P = 1.58 × 10). No association was observed between iris color and early or late AMD. Sunlight exposure during working life is an important risk factor for AMD, whereas sunlight exposure after retirement seems to have less influence on the disease development. Therefore, preventive measures, for example, wearing sunglasses to minimize sunlight exposure, should start early to prevent development of AMD later in life.

  1. Varying relationship between 25-hydroxy-vitamin D, high density lipoprotein cholesterol, and serum 7-dehydrocholesterol reductase with sunlight exposure.

    Science.gov (United States)

    Patwardhan, Vivek G; Khadilkar, Anuradha V; Chiplonkar, Shashi A; Mughal, Zulf M; Khadilkar, Vaman V

    2015-01-01

    Cholesterol and cholecalciferol are synthesized from a common substrate 7-dehydrocholesterol. 7-dehydrocholesterol is converted to cholesterol by 7-dehydrocholesterol reductase enzyme (DHCR7) and to cholecalciferol by ultraviolet B radiation from sunlight. To examine the effect of sunlight exposure and serum DHCR7 levels on cholecalciferol and cholesterol levels and studying any interrelationship. In a cross-sectional observational study, 307 apparently healthy men (aged 40-60 years) were assessed for sunlight exposure, lipid levels, serum DHCR7, 25 hydroxyvitamin D (25(OH)D), body composition, and dietary milk calcium intake. Vitamin D deficiency (25(OH)D sunlight exposure (P sunlight exposure (sunlight exposure (1-2 h/d), there was no significant association. However, with higher sunlight exposure (>2 h/d), serum 25(OH)D concentrations were significantly negatively associated with HDL-C (P sunlight exposure, an inverse significant relationship was observed between 25(OH)D and serum DHCR7 (P sunlight exposure, no significant relationship was seen. 25(OH)D seems to show a varying relationship with HDL-C and serum DHCR7 at different durations of sunlight exposure. Copyright © 2015 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  2. Hypovitaminosis D in patients undergoing kidney transplant: the importance of sunlight exposure.

    Science.gov (United States)

    Vilarta, Cristiane F; Unger, Marianna D; Dos Reis, Luciene M; Dominguez, Wagner V; David-Neto, Elias; Moysés, Rosa M; Titan, Silvia; Custodio, Melani R; Hernandez, Mariel J; Jorgetti, Vanda

    2017-07-01

    Recent studies have shown a high prevalence of hypovitaminosis D, defined as a serum 25-hydroxyvitamin D level less than 30 ng/ml, in both healthy populations and patients with chronic kidney disease. Patients undergoing kidney transplant are at an increased risk of skin cancer and are advised to avoid sunlight exposure. Therefore, these patients might share two major risk factors for hypovitaminosis D: chronic kidney disease and low sunlight exposure. This paper describes the prevalence and clinical characteristics of hypovitaminosis D among patients undergoing kidney transplant. We evaluated 25-hydroxyvitamin D serum levels in a representative sample of patients undergoing kidney transplant. We sought to determine the prevalence of hypovitaminosis D, compare these patients with a control group, and identify factors associated with hypovitaminosis D (e.g., sunlight exposure and dietary habits). Hypovitaminosis D was found in 79% of patients undergoing kidney transplant, and the major associated factor was low sunlight exposure. These patients had higher creatinine and intact parathyroid hormone serum levels, with 25-hydroxyvitamin D being inversely correlated with intact parathyroid hormone serum levels. Compared with the control group, patients undergoing kidney transplant presented a higher prevalence of 25-hydroxyvitamin D deficiency and lower serum calcium, phosphate and albumin but higher creatinine and intact parathyroid hormone levels. Our results confirmed the high prevalence of hypovitaminosis D in patients undergoing kidney transplant. Therapeutic strategies such as moderate sunlight exposure and vitamin D supplementation should be seriously considered for this population.

  3. Sunlight exposure increases vitamin D sufficiency in growing pigs fed a diet formulated to exceed requirements.

    Science.gov (United States)

    Alexander, B M; Ingold, B C; Young, J L; Fensterseifer, S R; Wechsler, P J; Austin, K J; Larson-Meyer, D E

    2017-04-01

    Traditional confinement practices limit exposure to sunlight and vitamin D synthesis, and vitamin insufficiency occurs even with dietary supplementation. The aim of this study was to determine the effect of limited sun exposure on serum concentration of vitamin D and the expression of vitamin D synthesizing enzymes in the liver and kidney of pigs on a vitamin D sufficient diet. White-pigmented grower pigs (29.7 ± 2.3 kg) fed 15% CP diet ad libitum providing >1,200 IU vitamin D3/kg of feed were exposed to sunlight for 1 h each day at solar noon for 14 d at the spring equinox (March pigs, n = 10) or summer solstice (June pigs, n = 5) and again before slaughter in June (March pigs) and September (June pigs). Blood for the analysis of 25(OH)D was collected before and after sunlight exposure. Traditionally housed pigs served as controls. After initial sun exposure, blood samples were collected from June pigs daily for 5 d and weekly for 8 wk to determine vitamin D3 and 25(OH)D decay, respectively. Kidney and liver samples were collected from the June pigs at slaughter after sun exposure for analysis of messenger RNA expression of vitamin D binding protein and synthesizing/degrading enzymes. Average daily gain (ADG) was not influenced (P > 0.5) by sunlight exposure. June pigs had fewer days on feed, lower (P = 0.003) ADG and were slaughtered at a lighter (P Exposure to sunlight increased (P sunlight exposure increased serum concentration of 25(OH)D in March pigs by 200% and June pigs by 67%. Serum concentration of vitamin D3 was decreased (P exposure. Expression of vitamin D binding protein, vitamin D synthesizing CYP2R1, CYP27A1, CYP2D25, or degrading enzyme CYP24A1 were not influenced (P ≥ 0.19) by sunlight exposure. Expression of CYP27B1 was decreased (P = 0.04) in the kidney but tended to be increased (P = 0.06) in the liver after sun exposure. These results suggest limited sun exposure can efficiently increase serum concentration of vitamin D in growing pigs

  4. Socioeconomic status, sunlight exposure, and risk of malignant melanoma: the Western Canada Melanoma Study.

    Science.gov (United States)

    Gallagher, R P; Elwood, J M; Threlfall, W J; Spinelli, J J; Fincham, S; Hill, G B

    1987-10-01

    In a study of 261 male melanoma patients and age-and sex-matched controls, a strong positive univariate association between socioeconomic status, as determined by usual occupation, and risk of melanoma was detected. This association, however, was substantially explained by host constitutional factors and occupational, recreational, and vacation sunlight exposure. The study demonstrated an increased risk of melanoma in draftsmen and surveyors and a reduced risk of melanoma in construction workers and individuals employed in the finance, insurance, and real estate industry even after control for the effect of host factors and sunlight exposure.

  5. The relationships among birth season, sunlight exposure during infancy, and allergic disease.

    Science.gov (United States)

    Hwang, Jung Min; Oh, Se Hyun; Shin, Mee Yong

    2016-05-01

    The recent increase in the prevalence of allergic diseases is hypothetically attributed to immune dysregulation in turn caused by a reduction in exposure to sunlight. We explored relationships between birth season, sunlight exposure, exercise duration, and an allergic disease. We performed a questionnaire-based survey on allergic diseases among elementary school students. Birth time was categorized according to the season (summer and winter). The prevalence of atopic dermatitis (AD) "symptoms ever" was higher in the children born in winter than in those born in summer (adjusted odds ratio [aOR], 1.24; 95% confidence interval [CI], 1.03-1.49; P=0.024). Birth in winter was associated with an increase in the "symptoms in the past 12 months" prevalence of food allergy (FA) (aOR, 1.56; 95% CI, 1.09-2.24; P=0.015). The lifetime prevalence of allergic diseases except FA was higher in the children whose parents considered their sunlight exposure prior to 24 months of ageas inadequate than those who considered their exposure as adequate ("diagnosis ever" asthma: aOR, 1.4; 95% CI, 1.17-1.67; Psunlight exposure nor exercise duration was associated with the prevalence of an allergic disease. Birth in winter may be associated with development of AD and FA. Inadequate sunlight exposure before the age of 24 months might possibly increase the risks of development of asthma, AR, and AD.

  6. Development of an algorithm to predict serum vitamin D levels using a simple questionnaire based on sunlight exposure.

    Science.gov (United States)

    Vignali, Edda; Macchia, Enrico; Cetani, Filomena; Reggiardo, Giorgio; Cianferotti, Luisella; Saponaro, Federica; Marcocci, Claudio

    2017-01-01

    Sun exposure is the main determinant of vitamin D production. The aim of this study was to develop an algorithm to assess individual vitamin D status, independently of serum 25(OHD) measurement, using a simple questionnaire, mostly relying upon sunlight exposure, which might help select subjects requiring serum 25(OHD) measurement. Six hundred and twenty adult subjects living in a mountain village in Southern Italy, located at 954 m above the sea level and at a latitude of 40°50'11″76N, were asked to fill the questionnaire in two different periods of the year: August 2010 and March 2011. Seven predictors were considered: month of investigation, age, sex, BMI, average daily sunlight exposure, beach holidays in the past 12 months, and frequency of going outdoors. The statistical model assumes four classes of serum 25(OHD) concentrations: ≤10, 10-19.9, 20-29.9, and ≥30 ng/ml. The algorithm was developed using a two-step procedure. In Step 1, the linear regression equation was defined in 385 randomly selected subjects. In Step 2, the predictive ability of the regression model was tested in the remaining 235 subjects. Seasonality, daily sunlight exposure and beach holidays in the past 12 months accounted for 27.9, 13.5, and 6.4 % of the explained variance in predicting vitamin D status, respectively. The algorithm performed extremely well: 212 of 235 (90.2 %) subjects were assigned to the correct vitamin D status. In conclusion, our pilot study demonstrates that an algorithm to estimate the vitamin D status can be developed using a simple questionnaire based on sunlight exposure.

  7. HISTORY OF SUNLIGHT EXPOSURE IS A RISK FACTOR FOR AGE-RELATED MACULAR DEGENERATION

    NARCIS (Netherlands)

    Schick, T.; Ersoy, L.; Lechanteur, Y.T.; Saksens, N.T.; Hoyng, C.B.; Hollander, A.I. den; Kirchhof, B.; Fauser, S.

    2016-01-01

    PURPOSE: To evaluate effects of current and past sunlight exposure and iris color on early and late age-related macular degeneration (AMD). METHODS: Of 3,701 individuals from the EUGENDA database, 752 (20.3%) showed early AMD, 1,179 (31.9%) late AMD, and 1,770 (47.8%) were controls. Information abou

  8. HISTORY OF SUNLIGHT EXPOSURE IS A RISK FACTOR FOR AGE-RELATED MACULAR DEGENERATION

    NARCIS (Netherlands)

    Schick, T.; Ersoy, L.; Lechanteur, Y.T.; Saksens, N.T.; Hoyng, C.B.; Hollander, A.I. den; Kirchhof, B.; Fauser, S.

    2016-01-01

    PURPOSE: To evaluate effects of current and past sunlight exposure and iris color on early and late age-related macular degeneration (AMD). METHODS: Of 3,701 individuals from the EUGENDA database, 752 (20.3%) showed early AMD, 1,179 (31.9%) late AMD, and 1,770 (47.8%) were controls. Information abou

  9. Accelerated stability testing of organic photovoltaics using concentrated sunlight

    DEFF Research Database (Denmark)

    Katz, Eugene A.; Manor, Assaf; Mescheloff, Asaf;

    2012-01-01

    We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported.......We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported....

  10. IS THERE A LINK BETWEEN SUNLIGHT EXPOSURE AND 25-HYDROXYVITAMIN D DEFICIENCY IN CHRONIC KIDNEY DISEASE PATIENTS?

    Directory of Open Access Journals (Sweden)

    Angela Yee-Moon Wang

    2012-06-01

    In conclusion, our study confirmed an extremely high prevalence of vitamin D deficiency and an important association between outdoor sunlight exposure and 25(OHD deficiency in Chinese stage 3-5 CKD patients. Further study is needed to determine whether increasing daily outdoor sunlight exposure may represent a cost-free treatment for correcting nutritional 25(OHD deficiency in the CKD population.

  11. Photosensitized rose Bengal-induced phototoxicity on human melanoma cell line under natural sunlight exposure.

    Science.gov (United States)

    Srivastav, Ajeet K; Mujtaba, Syed Faiz; Dwivedi, Ashish; Amar, Saroj K; Goyal, Shruti; Verma, Ankit; Kushwaha, Hari N; Chaturvedi, Rajnish K; Ray, Ratan Singh

    2016-03-01

    Rose Bengal (RB) is an anionic water-soluble xanthene dye, which used for many years to assess eye cornea and conjunctiva damage. RB showed strong absorption maxima (λmax) under visible light followed by UV-B and UV-A. RB under sunlight exposure showed a time-dependent photodegradation. Our results show that photosensitized RB generates (1)O2 via Type-II photodynamic pathway and induced DNA damage under sunlight/UV-R exposure. 2'dGuO degradation, micronuclei formation, and single- and double-strand breakage were the outcome of photogenotoxicity caused by RB. Quenching studies with NaN3 advocate the involvement of (1)O2 in RB photogenotoxicity. RB induced linoleic acid photoperoxidation, which was parallel to (1)O2-mediated DNA damage. Oxidative stress in A375 cell line (human melanoma cell line) was detected through DCF-DA assay. Photosensitized RB decreased maximum cellular viability under sunlight followed by UV-B and UV-A exposures. Apoptosis was detected as a pattern of cell death through the increased of caspase-3 activity, decreased mitochondrial membrane potential, and PS translocation through inner to outer plasma membrane. Increased cytosolic levels of Bax also advocate the apoptotic cell death. We propose a p53-mediated apoptosis via increased expression of Bax gene and protein. Thus, the exact mechanism behind RB phototoxicity was the involvement of (1)O2, which induced oxidative stress-mediated DNA and membrane damage, finally apoptotic cell death under natural sunlight exposure. The study suggests that after the use of RB, sunlight exposure may avoid to prevent from its harmful effects. Copyright © 2015. Published by Elsevier B.V.

  12. Sunlight exposure during leisure activities and risk of prostate cancer in Montréal, Canada, 2005-2009.

    Science.gov (United States)

    Yu, Jennifer; Lavoué, Jérôme; Parent, Marie-Élise

    2014-07-28

    Prostate cancer (PCa) is the leading cause of cancer in men in many developed countries, but no modifiable risk factors have been identified. A handful of analytical studies have suggested a possible etiological role for sunlight exposure. We report here on the association between leisure-time sunlight exposure during adulthood and PCa risk in the context of a population-based case-control study. In all, 1,904 PCa cases were ascertained across Montreal French hospitals between 2005 and 2009. Concurrently, 1,962 population controls, frequency matched to cases by age (±5 years), were selected from the electoral list for French-speakers in Greater Montreal. Interviews elicited the frequency of engagement in any leisure activity during adulthood. This was used to derive cumulative sunlight exposure indices: a cumulative number of leisure activities events entailing sunlight exposure and a cumulative duration of sunlight exposure during leisure activities. Unconditional logistic regression was conducted to yield odds ratios (OR) and 95% confidence intervals (CI) for estimating the association between sunlight exposure indices and PCa risk, adjusting for age, ancestry, family history of PCa, PCa screening, education, solar protection, body mass index and physical activity. Compared with men in the upper quartile category for the number of sunlight exposure events, men never exposed during leisure time had an OR of 1.32 (95% CI: 0.82-2.14). ORs were 1.11, 0.91 and 1.00 for the first to the third quartiles of exposure, respectively. Similar results were observed for cumulative duration of exposure to sunlight, and by PCa aggressiveness. These findings provide little evidence of an association between sunlight exposure during leisure-time and PCa risk. Men with no sunlight exposure appeared at somewhat higher risks but none of the estimates achieved statistical significance.

  13. [The Impact of Sunlight Exposure on the Health of Older Adults].

    Science.gov (United States)

    Lin, Tzu-Chia; Liao, Yen-Chi

    2016-08-01

    Appropriate exposure to sunlight not only contributes to the production of vitamin D, which has been associated with enhanced bone health, mood, and cognitive functions, but also regulates the secretion of melatonin, which has been associated with the mediation of circadian rhythms, improved sleep quality, and optimized physical and social activity in the elderly. However, damage to the skin, eyes, and immune system has also been widely associated with long-term exposure to sunlight. Several studies have shown that many elderly, especially those that reside in institutions, do not receive sufficient sunlight exposure. Institutionalized elderly tend to participate in indoor activities and spend significant periods of time alone and asleep in front of the television. Furthermore, factors such as poor health, environmental design, indoor/outdoor preference, and activity design may impact the access of institutionalized elderly to sunlight more than their non-institutionalized peers. Therefore, we suggest that in addition to obtaining sufficient levels of vitamin D from their diet and from supplements, the elderly should perform outdoor activities for 20-30 minutes a day for five days each week. Furthermore, we suggest that the environment of the care facility should be made be more accessible and that some activities should be held outdoors.

  14. Staphylococcus aureus Strain Newman Photoinactivation and Cellular Response to Sunlight Exposure.

    Science.gov (United States)

    McClary, Jill S; Sassoubre, Lauren M; Boehm, Alexandria B

    2017-09-01

    Sunlight influences microbial water quality of surface waters. Previous studies have investigated photoinactivation mechanisms and cellular photostress responses of fecal indicator bacteria (FIB), including Escherichia coli and enterococci, but further work is needed to characterize photostress responses of bacterial pathogens. Here we investigate the photoinactivation of Staphylococcus aureus (strain Newman), a pigmented, waterborne pathogen of emerging concern. We measured photodecay using standard culture-based assays and cellular membrane integrity and investigated photostress response by measuring the relative number of mRNA transcripts of select oxidative stress, DNA repair, and metabolism genes. Photoinactivation experiments were performed in both oxic and anoxic systems to further investigate the role of oxygen-mediated and non-oxygen-mediated photoinactivation mechanisms. S. aureus lost culturability much faster in oxic systems than in anoxic systems, indicating an important role for oxygen in photodecay mechanisms. S. aureus cell membranes were damaged by sunlight exposure in anoxic systems but not in oxic systems, as measured by cell membrane permeability to propidium iodide. After sunlight exposure, S. aureus increased expression of a gene coding for methionine sulfoxide reductase after 12 h of sunlight exposure in the oxic system and after 6 h of sunlight exposure in the anoxic system, suggesting that methionine sulfoxide reductase is an important enzyme for defense against both oxygen-dependent and oxygen-independent photostresses. This research highlights the importance of oxygen in bacterial photoinactivation in environmentally relevant systems and the complexity of the bacterial photostress response with respect to cell structure and transcriptional regulation.IMPORTANCEStaphylococcus aureus is a pathogenic bacterium that causes gastrointestinal, respiratory, and skin infections. In severe cases, S. aureus infection can lead to life

  15. A comparison of hip fracture incidence rates among elderly in Sweden by latitude and sunlight exposure.

    Science.gov (United States)

    Nilson, Finn; Moniruzzaman, Syed; Andersson, Ragnar

    2014-03-01

    Research has shown that hip fracture risk increases with latitude; hypothetically due to reduced sunlight exposure and its effect on bone quality. Sweden, with large differences in latitude and UV radiation, is ideal to study in order to analyse the association between latitude and UV radiation on age- and sex-specific hip fracture rates among elderly. Aggregated (2006-2008) age- and sex-specific hip fracture data was obtained for each Swedish municipality as well as the municipality's latitudinal coordinates and aggregated (2006-2008) UV radiation levels. Pearson correlations were calculated between hip fracture incidence rates, latitude and UV radiation. Independent t tests were calculated on tertile-categorized latitudinal data in order to investigate the difference in hip fracture risk between these categories. Statistically significant correlations were seen in all groups between hip fracture incidence rates and latitude as well as UV radiation. The independent t tests showed that this correlation was mainly due to high incidence rates in high latitude municipalities. Statistically significant correlations are seen between hip fracture incidence rates and latitude as well as UV radiation in Sweden and the northern parts of Sweden have an increased risk of hip fractures compared to the middle and southern parts. To our knowledge this is the first study using a national discharge register that shows this relationship and provides a starting point for further research to investigate why populations in northern Sweden have a higher risk of hip fractures compared to other Swedish regions.

  16. Effect of sunlight exposure on cognitive function among depressed and non-depressed participants: a REGARDS cross-sectional study.

    Science.gov (United States)

    Kent, Shia T; McClure, Leslie A; Crosson, William L; Arnett, Donna K; Wadley, Virginia G; Sathiakumar, Nalini

    2009-07-28

    Possible physiological causes for the effect of sunlight on mood are through the suprachiasmatic nuclei and evidenced by serotonin and melatonin regulation and its associations with depression. Cognitive function involved in these same pathways may potentially be affected by sunlight exposure. We evaluated whether the amount of sunlight exposure (i.e. insolation) affects cognitive function and examined the effect of season on this relationship. We obtained insolation data for residential regions of 16,800 participants from a national cohort study of blacks and whites, aged 45+. Cognitive impairment was assessed using a validated six-item screener questionnaire and depression status was assessed using the Center for Epidemiologic Studies Depression Scale. Logistic regression was used to find whether same-day or two-week average sunlight exposure was related to cognitive function and whether this relationship differed by depression status. Among depressed participants, a dose-response relationship was found between sunlight exposure and cognitive function, with lower levels of sunlight associated with impaired cognitive status (odds ratio = 2.58; 95% CI 1.43-6.69). While both season and sunlight were correlated with cognitive function, a significant relation remained between each of them and cognitive impairment after controlling for their joint effects. The study found an association between decreased exposure to sunlight and increased probability of cognitive impairment using a novel data source. We are the first to examine the effects of two-week exposure to sunlight on cognition, as well as the first to look at sunlight's effects on cognition in a large cohort study.

  17. Years of sunlight exposure and cataract: a case-control study in a Mediterranean population

    Science.gov (United States)

    Pastor-Valero, María; Fletcher, Astrid E; de Stavola, Bianca L; Chaqués-Alepúz, Vicente

    2007-01-01

    Background We aimed to investigate the relation between sunlight exposure and risk of cataract. Methods We carried out a frequency-matched case-control study of 343 cases and 334 controls attending an ophthalmology outpatient clinic at a primary health-care center in a small town near Valencia, Spain. All cases were diagnosed as having a cataract in at least one eye based on the Lens Opacification Classification system (LOCS II). Controls had no opacities in either eye. All cases and controls were interviewed for information on outdoor exposure, "usual" diet, history of severe episodes of diarrhea illness, life-style factors and medical and socio-demographic variables. Blood antioxidant vitamin levels were also analyzed. We used logistic regression models to estimate sex and age-adjusted odds ratios (ORs) by quintiles of years of occupational outdoor exposure, adjusting for potential confounders such as smoking, alcohol consumption, serum antioxidants and education. Results No association was found between years of outdoor exposure and risk of cataract. However, exploratory analyses suggested a positive association between years of outdoor exposure at younger ages and risk of nuclear cataract later in life. Conclusion Our study does not support an association with cataract and sunlight exposure over adult life. PMID:18039367

  18. Years of sunlight exposure and cataract: a case-control study in a Mediterranean population

    Directory of Open Access Journals (Sweden)

    de Stavola Bianca L

    2007-11-01

    Full Text Available Abstract Background We aimed to investigate the relation between sunlight exposure and risk of cataract. Methods We carried out a frequency-matched case-control study of 343 cases and 334 controls attending an ophthalmology outpatient clinic at a primary health-care center in a small town near Valencia, Spain. All cases were diagnosed as having a cataract in at least one eye based on the Lens Opacification Classification system (LOCS II. Controls had no opacities in either eye. All cases and controls were interviewed for information on outdoor exposure, "usual" diet, history of severe episodes of diarrhea illness, life-style factors and medical and socio-demographic variables. Blood antioxidant vitamin levels were also analyzed. We used logistic regression models to estimate sex and age-adjusted odds ratios (ORs by quintiles of years of occupational outdoor exposure, adjusting for potential confounders such as smoking, alcohol consumption, serum antioxidants and education. Results No association was found between years of outdoor exposure and risk of cataract. However, exploratory analyses suggested a positive association between years of outdoor exposure at younger ages and risk of nuclear cataract later in life. Conclusion Our study does not support an association with cataract and sunlight exposure over adult life.

  19. Cellular and molecular mechanism of ofloxacin induced apoptotic cell death under ambient UV-A and sunlight exposure.

    Science.gov (United States)

    Dwivedi, A; Mujtaba, S F; Yadav, N; Kushwaha, H N; Amar, S K; Singh, S K; Pant, M C; Ray, R S

    2014-03-01

    Ofloxacin (OFLX) is a racemic mixture of levofloxacin which revealed phototoxicity in patients exposed with sunlight after medication. Here, we have been addressed the possible cellular and molecular mechanisms of OFLX induced apoptosis under ambient UV-A and sunlight exposure using HaCaT cell line as a model. The results showed that Photodegradation and three photo-products formation of OFLX by LC-MS/MS under ambient intensities of UV-A (1.5 and 2.2 mW/cm(2)) and sunlight. OFLX produced (1)O2, O2(.-), and OH radicals via type-II- and type-I-dependent reaction mechanism, which corroborated by its specific quenchers. 2'-dGua degradation in photochemical and % tail DNA formation in cell line using comet test advocated the genotoxic potential of OFLX. Photocytotoxic assays (MTT and NRU) revealed the considerable decline in cell viability by OFLX. OFLX triggered apoptosis, proved by cell cycle, Annexin V/PI double staining along with acridine orange (AO)/ethidium bromide (EB), and Hoechst staining as well as caspase-3 activity by colorimetric assay. OFLX induced lysosomal disruption and mitochondrial membrane destabilization confirmed through fluorescence staining with AO/JC-1. OFLX significantly upregulated the expression of p21 and bax genes. In conclusion, the study revealed that photosensitized OFLX induced apoptosis via ROS-mediated DNA damage, destabilization of lysosomal and mitochondrial membrane, and upregulation of p21, bax, and caspase-3 genes.

  20. Factors influencing adherence with therapeutic sunlight exposure in older people in intermediate care facilities.

    Science.gov (United States)

    Durvasula, Seeta; Sambrook, Philip N; Cameron, Ian D

    2012-01-01

    The purpose of this study was to investigate the factors influencing low adherence with therapeutic sunlight exposure in a randomized controlled trial conducted with older people living in intermediate care facilities. The study involved participants in the FREEDOM (Falls Risk Epidemiology: Effect of vitamin D on skeletal Outcomes and other Measures) study, a randomized controlled trial of therapeutic sun exposure to reduce falls in older people in intermediate care facilities. Semi-structured interviews were conducted with thirty participants in the FREEDOM trial, and with ten sunlight officers who were employed to facilitate the sun exposure. Two focus groups involving 10 participants in the FREEDOM trial were also held at the end of the intervention period. Common themes were derived from the interview and focus group transcripts. The study showed that the perceived health benefits did not influence adherence with the sun exposure. Factors such as socializing with others and being outdoors were more important in encouraging attendance. The main barriers to adherence included the perceived inflexibility and regimentation of daily attendance, clash with other activities, unsuitable timing and heat discomfort. This study showed that providing greater flexibility and autonomy to older people in how and when they receive sun exposure is likely to improve adherence. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Attitude of future healthcare provider towards vitamin D significance in relation to sunlight exposure.

    Science.gov (United States)

    Qureshi, Aysha Zia; Zia, Zubia; Gitay, Mehnaz Nuruddin; Khan, Muhammad Umair; Khan, Muhammad Saad

    2015-10-01

    Nature is the kindest of all to provide man with all the necessary components for a healthy life at easily accessible lengths. The deprivation arises with unawareness and lack of correct measures to extract the benefits. Medical education makes the youth aware of the numerous disorders and diseases, as well as their preventions and treatments. This awareness needs to be realized and implemented in the society, and it is not possible without the advisers acting on the same lines. Since doctors are the most trusted and their advice is adopted without much thought, it is extremely inevitable to analyze the attitude of medical students of various levels to understand the cause of their negligence toward their own deficiencies, the focus for this study being vitamin D (VD). A cross sectional descriptive study was done on undergraduate medical students of health profession from different universities of Pakistan to access the awareness regarding VD deficiency associated with sunlight. Informed consent was duly signed by each participant after which self-constructed questionnaire was provided to them and data are collected. SPSS 17 was used for Statistical analysis. Final students are well aware of VD significance, take food rich in VD but still suffer from fatigue and muscular pain. No treatment was taken for fatigue and muscular pain by majority of these sufferers and those who took treatment were VD supplement. The health sufferers were mostly those who avoided sunlight highlighting the role of VD in maintaining an active lifestyle as well as the significance of sunlight in maintaining VD levels. It can be concluded that in spite of awareness, the role of sunlight exposure and the proper time and duration of exposure cannot be ignored to create a healthy and active society.

  2. Development and validation of sunlight exposure measurement questionnaire (SEM-Q) for use in adult population residing in Pakistan.

    Science.gov (United States)

    Humayun, Quratulain; Iqbal, Romaina; Azam, Iqbal; Khan, Aysha Habib; Siddiqui, Amna Rehana; Baig-Ansari, Naila

    2012-06-08

    Vitamin D deficiency has been identified as a major public health problem worldwide. Sunlight is the main source of vitamin D and its measurement using dosimeters is expensive and difficult for use in population-based studies. Hence, the aim of this study was to develop and validate questionnaires to assess sunlight exposure in healthy individuals residing in Karachi, Pakistan. Two questionnaires with seven important items for sunlight exposure assessment were developed. Fifty four healthy adults were enrolled based on their reported sunlight exposure (high = 17, moderate = 18, low = 19) from Aga Khan University, Karachi. Over four days, study participants were asked to wear a dosimeter between sunrise and sunset and report time spent and activities undertaken in the sun for questionnaire validation. Algorithm for item weightage was created as an average score based on ultraviolet B percentage received. Blood samples were obtained for serum vitamin D. The mean time (minutes) spent in sun over 4 days (±SD) was 69.5 (±32) for low, 83.5 (±29.7) for moderate and 329 (±115) for high exposure group. The correlation between average time (minutes) spent in sun over 4 days and mean change in absorbance of UV dosimeters for 4 days was 0.60 (p sunlight exposure measurement questionnaires were valid tools for use in large epidemiological studies to quantify sunlight exposure.

  3. Sunlight exposure or vitamin D supplementation for vitamin D-deficient non-western immigrants: a randomized clinical trial.

    Science.gov (United States)

    Wicherts, I S; Boeke, A J P; van der Meer, I M; van Schoor, N M; Knol, D L; Lips, P

    2011-03-01

    Vitamin D deficiency is very common in non-western immigrants. In this randomized clinical trial, vitamin D 800 IU/day or 100,000 IU/3 months were compared with advised sunlight exposure. Vitamin D supplementation was more effective than advised sunlight exposure in improving vitamin D status and lowering parathyroid hormone levels. Vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] sunlight exposure. To determine whether the effect of vitamin D(3) supplementation (daily 800 IU or 100,000 IU/3 months) or sunlight exposure advice is similar with regard to serum 25(OH)D and parathyroid hormone (PTH) concentrations. Randomized clinical trial in 11 general practices in The Netherlands. Non-western immigrants, aged 18-65 years (n = 232) and serum 25(OH)D sunlight exposure for 6 months (March-September). Blood samples were collected at baseline, during treatment (3 months, 6 months), and at follow-up (12 months). Statistical analysis was performed with multilevel regression modelling. The intention-to-treat analysis included 211 persons. Baseline serum 25(OH)D was 22.5 ± 11.1 nmol/l. After 6 months, mean serum 25(OH)D increased to 53 nmol/l with 800 IU/day, to 50.5 nmol/l with 100,000 IU/3 months, and to 29.1 nmol/l with advised sunlight exposure (supplementation vs sunshine p sunlight group (p sunlight exposure for treating vitamin D deficiency in non-western immigrants.

  4. The effect of sunlight exposure on interleukin-6 levels in depressive and non-depressive subjects.

    Science.gov (United States)

    Levandovski, Rosa; Pfaffenseller, Bianca; Carissimi, Alicia; Gama, Clarissa S; Hidalgo, Maria Paz Loayza

    2013-03-05

    The objective of this epidemiological study was to evaluate the effect of length of sunlight exposure on interleukin 6 (IL-6) levels in depressive and non-depressive subjects. This was a cross-sectional study with 154 subjects (54 males, mean age: 43.5 ± 12.8 years) who were living in a rural area in south Brazil. Chronobiological and light parameters were assessed using the Munich Chronotype Questionnaire. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index. Depressive symptoms were assessed with the Beck Depression Inventory. Plasma levels of inflammatory cytokines (IL-2, IL-4, IL-6, IL-10, tumor necrosis factor-α, and interferon) were collected during the daytime and measured. IL-6 levels showed a positive correlation with light exposure (r = 0.257; p exposure was an independent factor for predicting IL-6 levels (ß = 0.26; p = 0.002). In non-depressed subjects, exposure to a different intensity of light did not affect IL-6 levels (t = -1.6; p = 0.1). However, when the two depressive groups with low and high light exposure were compared, the low light exposure group had lower levels of IL-6 compared with the high light exposure group (t = -2.19 and p = 0.0037). The amount of time that participants are exposed to sunlight is directly related to their IL-6 levels. Additionally, depressed subjects differ in their IL-6 levels if they are exposed to light for differing amounts of time.

  5. Sunlight exposure and sun sensitivity associated with disability progression in multiple sclerosis.

    Science.gov (United States)

    D'hooghe, M B; Haentjens, P; Nagels, G; Garmyn, M; De Keyser, J

    2012-04-01

    Sunlight and vitamin D have been inversely associated with the risk of multiple sclerosis (MS). We investigated sunlight exposure and sun sensitivity in relation to disability progression in MS. We conducted a survey among persons with MS, registered by the Flemish MS society, Belgium, and stratified data according to relapsing-onset and progressive-onset MS. We used Kaplan-Meier survival and Cox proportional hazard regression analyses with time to Expanded Disability Status Scale (EDSS) 6 as outcome measure. Hazard ratios for the time from onset and from birth were calculated for the potentially predictive variables, adjusting for age at onset, gender and immunomodulatory treatment. 704 (51.3%) of the 1372 respondents had reached EDSS 6. In relapsing-onset MS, respondents reporting equal or higher levels of sun exposure than persons of the same age in the last 10 years had a decreased risk of reaching EDSS 6. In progressive-onset MS, increased sun sensitivity was associated with an increased hazard of reaching EDSS 6. The association of higher sun exposure with a better outcome in relapsing-onset MS may be explained by either a protective effect or reverse causality. Mechanisms underlying sun sensitivity might influence progression in progressive-onset MS.

  6. Quantification of ultraviolet radiation-induced DNA damage in the urine of Swedish adults and children following exposure to sunlight.

    Science.gov (United States)

    Liljendahl, Tove Sandberg; Kotova, Natalia; Segerbäck, Dan

    2012-11-01

    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. Background levels of T=T increased significantly following exposure to sunlight. Amounts of T=T in urine of children and adults were not significantly different after adjusting for area of skin exposed and physiological differences. UVR dose and amounts of T=T correlated for both adults and children. Recreational exposure to sunlight in Sweden induces levels of DNA damage, clearly detectable in urine.

  7. Recommended summer sunlight exposure amounts fail to produce sufficient vitamin D status in UK adults of South Asian origin.

    Science.gov (United States)

    Farrar, Mark D; Kift, Richard; Felton, Sarah J; Berry, Jacqueline L; Durkin, Marie T; Allan, Donald; Vail, Andy; Webb, Ann R; Rhodes, Lesley E

    2011-11-01

    The cutaneous synthesis of vitamin D is dependent on UVB from sunlight, but melanin reduces the penetration of UVB and thus contributes to vitamin D insufficiency in individuals with darker skin. The national guidance provided on amounts of sunlight exposure in the United Kingdom is for the light-skinned population, and in the absence of dedicated information, darker-skinned people may attempt to follow this guidance. We determined the relative effect of a simulation of UK recommendations of summer sunlight exposure on the vitamin D status of individuals of South Asian ethnicity compared with that of whites. In a prospective cohort study, simulated summer sunlight exposures were provided under rigorous dosimetric conditions to 15 adults (aged 20-60 y) of South Asian ethnicity, and serum 25-hydroxyvitamin D [25(OH)D] was measured weekly. Dietary vitamin D intake was estimated. Outcomes were compared with those of 109 whites (aged 20-60 y) treated with the identical UV-radiation exposure protocol. At baseline (winter trough), all South Asians were vitamin D-insufficient [25(OH)D concentrations Sunlight-exposure recommendations are inappropriate for individuals of South Asian ethnicity who live at the UK latitude. More guidance is required to meet the vitamin D requirements of this sector of the population. This study was registered at www.isrctn.org as ISRCTN 07565297.

  8. Test technology on CCD anti-sunlight jamming based on complex circumstance

    Science.gov (United States)

    Shi, Sheng-bing; Chen, Zhen-xing; Han, Fu-li

    2016-09-01

    Visible-light reconnaissance device based on CCD is applied to all kinds of weapons, CCD cannot work because of saturation when it faces intense light. Sun is intense light source in nature and assignably influences CCD performance. In this paper, aim is appraising CCD anti-sunlight ability, object reflection characteristic test system is designed, based on typical background reflection characteristic including grant, sand and so on, complex circumstance is formulated and test project is optimized with orthogonal design method, problem that is without test technology on CCD anti-sunlight jamming is solved.

  9. Surface exposure to sunlight stimulates CO2 release from permafrost soil carbon in the Arctic.

    Science.gov (United States)

    Cory, Rose M; Crump, Byron C; Dobkowski, Jason A; Kling, George W

    2013-02-26

    Recent climate change has increased arctic soil temperatures and thawed large areas of permafrost, allowing for microbial respiration of previously frozen C. Furthermore, soil destabilization from melting ice has caused an increase in thermokarst failures that expose buried C and release dissolved organic C (DOC) to surface waters. Once exposed, the fate of this C is unknown but will depend on its reactivity to sunlight and microbial attack, and the light available at the surface. In this study we manipulated water released from areas of thermokarst activity to show that newly exposed DOC is >40% more susceptible to microbial conversion to CO(2) when exposed to UV light than when kept dark. When integrated over the water column of receiving rivers, this susceptibility translates to the light-stimulated bacterial activity being on average from 11% to 40% of the total areal activity in turbid versus DOC-colored rivers, respectively. The range of DOC lability to microbes seems to depend on prior light exposure, implying that sunlight may act as an amplification factor in the conversion of frozen C stores to C gases in the atmosphere.

  10. Effect of preadmission sunlight exposure on intensive care unit-acquired delirium: a multicenter study.

    Science.gov (United States)

    Simons, Koen S; Workum, Jessica D; Slooter, Arjen J C; van den Boogaard, Mark; van der Hoeven, Johannes G; Pickkers, Peter

    2014-04-01

    It is assumed that there is a relation between light exposure and delirium incidence. The aim of our study was to determine the effect of prehospital light exposure on the incidence of intensive care unit (ICU)-acquired delirium. Data from 3 ICUs in the Netherlands were analyzed retrospectively. Delirium was assessed with the Confusion Assessment Method for the ICU. Daily light intensity data were obtained from meteorological stations in the vicinity of the 3 hospitals. The association between light intensity and delirium incidence was analyzed using logistic regression analysis adjusting for known covariates for delirium. Data of 3198 patients, aged (mean ± SD) 61.9 ± 15.3 years with Acute Physiology and Chronic Health Evaluation II score 16.4 ± 6.6 were analyzed. Delirium incidence was 31.2% and did not vary significantly throughout the year. Twenty-eight-day preadmission photoperiod was highest in spring and lowest in winter; however, no association between light exposure and delirium incidence was found (odds ratio, 1.00; 95% confidence interval, 0.99-1.00; P = 0.72). Furthermore, delirium was significantly associated with age, infection, use of sedatives, Acute Physiology and Chronic Health Evaluation II score, and diagnosis of neurological disease or trauma. The incidence of delirium does not differ per season and prior sunlight exposure does not play a role of importance in the development of ICU-acquired delirium. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Direct sunlight facility for testing and research in HCPV

    Science.gov (United States)

    Sciortino, Luisa; Agnello, Simonpietro; Barbera, Marco; Bonsignore, Gaetano; Buscemi, Alessandro; Candia, Roberto; Cannas, Marco; Collura, Alfonso; Di Cicca, Gaspare; Gelardi, Franco Mario; Cicero, Ugo Lo; Montagnino, Fabio Maria; Napoli, Gianluca; Paredes, Filippo; Spallino, Luisa; Varisco, Salvo

    2014-09-01

    A facility for testing different components for HCPV application has been developed in the framework of "Fotovoltaico ad Alta Efficienza" (FAE) project funded by the Sicilian Regional Authority (PO FESR Sicilia 2007/2013 4.1.1.1). The testing facility is equipped with an heliostat providing a wide solar beam inside the lab, an optical bench for mounting and aligning the HCPV components, electronic equipments to characterize the I-V curves of multijunction cells operated up to 2000 suns, a system to circulate a fluid in the heat sink at controlled temperature and flow-rate, a data logging system with sensors to measure temperatures in several locations and fluid pressures at the inlet and outlet of the heat sink, and a climatic chamber with large test volume to test assembled HCPV modules.

  12. Direct sunlight facility for testing and research in HCPV

    Energy Technology Data Exchange (ETDEWEB)

    Sciortino, Luisa, E-mail: luisa.sciortino@unipa.it; Agnello, Simonpietro, E-mail: luisa.sciortino@unipa.it; Bonsignore, Gaetano; Cannas, Marco; Gelardi, Franco Mario; Napoli, Gianluca; Spallino, Luisa [Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Via Archirafi 36, 90123 PA (Italy); Barbera, Marco [Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Via Archirafi 36, 90123 PA, Italy and Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Palermo G. S. Vaiana, Piazza del Parlamento 1, 90134 PA (Italy); Buscemi, Alessandro; Montagnino, Fabio Maria; Paredes, Filippo [IDEA s.r.l., Contrada Molara, Zona Industriale III Fase, 90018 Termini Imerese (Panama) (Italy); Candia, Roberto; Collura, Alfonso; Di Cicca, Gaspare; Cicero, Ugo Lo; Varisco, Salvo [Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Palermo G. S. Vaiana, Piazza del Parlamento 1, 90134 PA (Italy)

    2014-09-26

    A facility for testing different components for HCPV application has been developed in the framework of 'Fotovoltaico ad Alta Efficienza' (FAE) project funded by the Sicilian Regional Authority (PO FESR Sicilia 2007/2013 4.1.1.1). The testing facility is equipped with an heliostat providing a wide solar beam inside the lab, an optical bench for mounting and aligning the HCPV components, electronic equipments to characterize the I-V curves of multijunction cells operated up to 2000 suns, a system to circulate a fluid in the heat sink at controlled temperature and flow-rate, a data logging system with sensors to measure temperatures in several locations and fluid pressures at the inlet and outlet of the heat sink, and a climatic chamber with large test volume to test assembled HCPV modules.

  13. Exposure to sunlight reduces the risk of myopia in rhesus monkeys.

    Science.gov (United States)

    Wang, Yong; Ding, Hui; Stell, William K; Liu, Liangping; Li, Saiqun; Liu, Hongshan; Zhong, Xingwu

    2015-01-01

    Exposure to sunlight has recently been postulated as responsible for the effect that more time spent outdoors protects children from myopia, while early life exposure to natural light was reported to be possibly related to onset of myopia during childhood. In this study, we had two aims: to determine whether increasing natural light exposure has a protective effect on hyperopic defocus-induced myopia, and to observe whether early postnatal exposure to natural light causes increased risk of refractive error in adolescence. Eight rhesus monkeys (aged 20-30 days) were treated monocularly with hyperopic-defocus (-3.0D lens) and divided randomly into two groups: AL group (n=4), reared under Artificial (indoor) Lighting (08:00-20:00); and NL group (n=4), exposed to Natural (outdoor) Light for 3 hours per day (11:00-14:00), and to indoor lighting for the rest of the light phase. After being reared with lenses for ca. 190 days, all monkeys were returned to unrestricted vision until the age of 3 years. Another eight age-matched monkeys, reared with unrestricted vision under artificial lighting since birth, were employed as controls. The ocular refraction, corneal curvature and axial dimensions were measured before lens-wearing (at 23±3 days of age), monthly during the light phase, and at the age of puberty (at 1185+3 days of age). During the lens-wearing treatment, infant monkeys in the NL group were more hyperopic than those in the AL group (F=5.726, P=0.032). Furthermore, the two eyes of most NL monkeys remained isometropic, whereas 3 of 4 AL monkeys developed myopic anisometropia more than -2.0D. At adolescence, eyes of AL monkeys showed significant myopic anisometropia compared with eyes of NL monkeys (AL vs NL: -1.66±0.87D vs -0.22±0.44D; P=0.002) and controls (AL vs Control: -1.66±0.87D vs -0.05±0.85D; Pexposure to natural outdoor light might have an effect to reduced hyperopic defocus-induced myopia. Also, the data imply that early life exposure to sunlight may

  14. Mitochondrial tolerance to single and repeat exposure to simulated sunlight in human epidermal and dermal skin cells.

    Science.gov (United States)

    Kelly, J; Murphy, J E J

    2016-12-01

    Sunlight represents the primary threat to mitochondrial integrity in skin given the unique nature of the mitochondrial genome and its proximity to the electron transport chain. The accumulation of mitochondrial DNA (mtDNA) mutations is a key factor in many human pathologies and this is linked to key roles of mitochondrial function in terms of energy production and cell regulation. The main objective of this study was to evaluate solar radiation induced changes in mitochondrial integrity, function and dynamics in human skin cells using a Q-Sun solar simulator to deliver a close match to the intensity of summer sunlight. Spontaneously immortalised human skin epidermal keratinocytes (HaCaT) and Human Dermal Fibroblasts (HDFn) were divided into two groups. Group A were irradiated once and Group B twice 7days apart and evaluated using cell survival, viability and mitochondrial membrane potential (MMP) and mass at 1, 4 and 7days post one exposure for Group A and 1, 4, 7 and 14days post second exposure for Group B. Viability and survival of HaCaT and HDFn cells decreased after repeat exposure to Simulated Sunlight Irradiation (SSI) with no recovery. HDFn cells showed no loss in MMP after one or two exposures to SSI compared to HaCaT cells which showed a periodic loss of MMP after one exposure with a repeat exposure causing a dramatic decrease from which cells did not recover. Mitochondrial Mass in exposed HDFn cells was consistent with control after one or two exposures to SSI; however mitochondrial mass was significantly decreased in HaCaT cells. Data presented here suggests that mitochondria in epidermal cells are more sensitive to sunlight damage compared to mitochondria in dermal cells, despite their origin, confirming a skin layer specific sensitivity to sunlight, but not as expected. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Serum levels of vitamin D, sunlight exposure, and knee cartilage loss in older adults: the Tasmanian older adult cohort study.

    Science.gov (United States)

    Ding, Changhai; Cicuttini, Flavia; Parameswaran, Venkat; Burgess, John; Quinn, Steve; Jones, Graeme

    2009-05-01

    To determine the associations between serum levels of vitamin D, sunlight exposure, and knee cartilage loss cross-sectionally and longitudinally in older adults. A total of 880 randomly selected subjects (mean age 61 years [range 51-79 years], 50% women) were studied at baseline, and 353 of these subjects were studied 2.9 years later. Serum levels of 25-hydroxyvitamin D (25[OH]D) were assessed by radioimmunoassay, and sunlight exposure was assessed by questionnaire. T1-weighted fat-suppressed magnetic resonance imaging (MRI) of the right knee was performed to determine knee cartilage volume and defects. Knee radiographic osteoarthritis (OA) and knee pain were also assessed. The mean 25(OH)D serum level was 52.8 nmoles/liter at baseline (range 13-119 nmoles/liter). Winter sunlight exposure and serum 25(OH)D level were both positively associated with medial and lateral tibial cartilage volume, and a serum 25(OH)D levelSunlight exposure and serum 25(OH)D levels are both associated with decreased knee cartilage loss (assessed by radiograph or MRI). This is best observed using the whole range of 25(OH)D levels rather than predefined cut points and implies that achieving vitamin D sufficiency may prevent and/or retard cartilage loss in knee OA.

  16. No indications for an ultraviolet B radiation induced decline of immunological parameters after sunlight exposure among HIV infected homosexual men

    NARCIS (Netherlands)

    Maas J; Termorshuizen F; Geskus RB; Coutinho RA; Loveren H van; GG&GD Amsterdam; LPI

    2000-01-01

    Whether sunlight (especially ultraviolet B radiation: UVB) exposure is harmful to the cellular immunity of HIV infected individuals and whether it is associated with an accelerated progression toward AIDS is still under debate. Among HIV+ homosexual participants of the Amsterdam Cohort Study, the de

  17. No indications for an ultraviolet B radiation induced decline of immunological parameters after sunlight exposure among HIV infected homosexual men

    NARCIS (Netherlands)

    Maas J; Termorshuizen F; Geskus RB; Coutinho RA; Loveren H van; GG&GD Amsterdam; LPI

    2000-01-01

    Whether sunlight (especially ultraviolet B radiation: UVB) exposure is harmful to the cellular immunity of HIV infected individuals and whether it is associated with an accelerated progression toward AIDS is still under debate. Among HIV+ homosexual participants of the Amsterdam Cohort Study, the de

  18. The influence of short-term exposure to tropical sunlight on boar seminal characteristics

    Science.gov (United States)

    Egbunike, G. N.; Dede, T. I.

    1980-06-01

    The seminal characteristics of 4 Large White boars exposed to direct tropical sunlight 45 min daily for three days were compared to those of their mates that were maintained under shade in the barn. During the period of exposure, both respiratory rate and rectal temperature increased significantly by 276.84 and 5.13% respectively in the exposed over the unexposed boars, thus indicating a high degree of hyperthermia. Although libido, as judged from the reaction time, was unaffected, the ejaculation time appeared to be longer for the stressed than unstressed animals. Gel mass, semen volume and pH appeared to be stable inspite of the treatment, unlike sperm motility and concentration which deteriorated. Also, the dehydrogenase activity of the semen was inferior in the stressed animals. Sperm output per ejaculate dropped drastically only in the week following exposure from 58.22 to 28.42 billion sperm as compared to corresponding values of 54.83 and 47.87 by the unexposed boars. Similarly, the frequency of sperm abnormality was higher in the stressed boars in this period after which the animals appeared to have recovered.

  19. Sunlight exposure and cardiovascular risk factors in the REGARDS study: a cross-sectional split-sample analysis.

    Science.gov (United States)

    Kent, Shia T; Cushman, Mary; Howard, George; Judd, Suzanne E; Crosson, William L; Al-Hamdan, Mohammad Z; McClure, Leslie A

    2014-06-19

    Previous research has suggested that vitamin D and sunlight are related to cardiovascular outcomes, but associations between sunlight and risk factors have not been investigated. We examined whether increased sunlight exposure was related to improved cardiovascular risk factor status. Residential histories merged with satellite, ground monitor, and model reanalysis data were used to determine previous-year sunlight radiation exposure for 17,773 black and white participants aged 45+ from the US. Exploratory and confirmatory analyses were performed by randomly dividing the sample into halves. Logistic regression models were used to examine relationships with cardiovascular risk factors. The lowest, compared to the highest quartile of insolation exposure was associated with lower high-density lipoprotein levels in adjusted exploratory (-2.7 mg/dL [95% confidence interval: -4.2, -1.2]) and confirmatory (-1.5 mg/dL [95% confidence interval: -3.0, -0.1]) models. The lowest, compared to the highest quartile of insolation exposure was associated with higher systolic blood pressure levels in unadjusted exploratory and confirmatory, as well as the adjusted exploratory model (2.3 mmHg [95% confidence interval: 0.8, 3.8]), but not the adjusted confirmatory model (1.6 mg/dL [95% confidence interval: -0.5, 3.7]). The results of this study suggest that lower long-term sunlight exposure has an association with lower high-density lipoprotein levels. However, all associations were weak, thus it is not known if insolation may affect cardiovascular outcomes through these risk factors.

  20. Is sunlight exposure a risk factor for age-related macular degeneration? A systematic review and meta-analysis.

    Science.gov (United States)

    Sui, Guo-Yuan; Liu, Guang-Cong; Liu, Guang-Ying; Gao, Yan-Yan; Deng, Yan; Wang, Wen-Ying; Tong, Shu-Hui; Wang, Lie

    2013-04-01

    Epidemiologists have recently investigated sunlight exposure as a risk factor for age-related macular degeneration (AMD), but there remains an ongoing dispute over this association due to insufficient evidence and unreliable data. To analyse comprehensively the epidemiological literature concerning the association between AMD and sunlight exposure. We systematically reviewed the epidemiological literature concerning the association between AMD and sunlight exposure. An electronic search was performed of PubMed, Web of Science and CNKI, which was supplemented by hand searching. The selection of studies, data abstraction and quality assessment were performed independently by three reviewers. After these steps, we performed a random-effects meta-analysis, followed by subgroup analysis and sensitivity analysis, including a random-effects meta-regression for study-specific covariates. Fourteen studies were identified. Twelve studies identified an increasing risk of AMD with greater sunlight exposure, six of which reported significant risks. The pooled OR was 1.379 (95% CI 1.091 to 1.745). The subgroup of non-population-based studies revealed a significant risk (OR 2.018, 1.248 to 3.265, p=0.004). We identified the gross domestic product (GDP) per capita (p=0.048), but not the latitude (p=0.21), as a factor that led to heterogeneity according to the meta-regression. The epidemiological literature published to date indicates that individuals with more sunlight exposure are at a significantly increased risk of AMD. The OR significantly decreased with increasing GDP per capita.

  1. Sunlight exposure is important for preventing hip fractures in patients with Alzheimer's disease, Parkinson's disease, or stroke.

    Science.gov (United States)

    Iwamoto, J; Takeda, T; Matsumoto, H

    2012-04-01

    Hypovitaminosis D as a result of malnutrition or sunlight deprivation, increased bone resorption, low bone mineral density (BMD), or an increased risk of falls may contribute to an increased risk of hip fractures in patients with neurological diseases, including Alzheimer's disease, Parkinson's disease, and stroke. The purpose of this study was to clarify the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with such neurological diseases. The English literature was searched using PubMed, and randomized controlled trials evaluating the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with Alzheimer's disease, Parkinson's disease, and stroke were identified. The relative risk and the 95% confidence interval were calculated for individual randomized controlled trials, and a pooled data analysis (meta-analysis) was performed. Three randomized controlled trials were identified. Sunlight exposure improved hypovitaminosis D and increased the BMD. The relative risk (95% confidence interval) of hip fractures was 0.22 (0.05, 1.01) for Alzheimer's disease, 0.27 (0.08, 0.96) for Parkinson's disease, and 0.17 (0.02, 1.36) for stroke. The relative risk (95% confidence interval) calculated for the pooled data analysis was 0.23 (0.10, 0.56) (P = 0.0012), suggesting a significant risk reduction rate of 77%. The present meta-analysis added additional evidence indicating the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with Alzheimer's disease, Parkinson's disease, and stroke. © 2011 John Wiley & Sons A/S.

  2. Seasonal effects on pterygium surgery outcome: implications for the role of sunlight exposure.

    Science.gov (United States)

    Sul, Sabahattin; Korkmaz, Şafak; Novruzlu, Şahin

    2014-05-01

    The aim of this study was to compare the results of pterygium surgery in patients when performed in the summer with the results of surgery performed in the winter. This retrospective study enrolled 55 eyes of 53 patients with primary pterygia who underwent a surgery between December 2011 and January 2012 (winter group, 32 eyes) or between June and July 2012 (summer group, 23 eyes). All the patients were followed up for at least 1 year. Pterygium recurrence, ocular discomfort, persistent conjunctival inflammation, and graft complications were evaluated postoperatively. There was no significant difference between the groups in terms of age or gender. All the patients were farmers in rural areas. The overall pterygium recurrence rate was 14.5% (8 of 55 eyes). The recurrence rate in the summer group was significantly higher than in the winter group (26.1% vs. 6.2%, P = 0.048). Persistent conjunctival inflammation was also significantly higher in the summer group than in the winter group (30.4% vs. 6.2%, P = 0.022). Pterygium recurrence was significantly higher in eyes with persistent conjunctival inflammation than in eyes without inflammation (66.6% vs. 4.3%, P exposure to sunlight during the summer.

  3. Taxicab tipping and sunlight

    Science.gov (United States)

    2017-01-01

    Does the level of sunlight affect the tipping percentage in taxicab rides in New York City? We examined this question using data on 13.82 million cab rides from January to October in 2009 in New York City combined with data on hourly levels of solar radiation. We found a small but statistically significant positive relationship between sunlight and tipping, with an estimated tipping increase of 0.5 to 0.7 percentage points when transitioning from a dark sky to full sunshine. The findings are robust to two-way clustering of standard errors based on hour-of-the-day and day-of-the-year and controlling for day-of-the-year, month-of-the-year, cab driver fixed effects, weather conditions, and ride characteristics. The NYC cab ride context is suitable for testing the association between sunlight and tipping due to the largely random assignment of riders to drivers, direct exposure to sunlight, and low confounding from variation in service experiences. PMID:28594917

  4. Efficacy of a dose range of simulated sunlight exposures in raising vitamin D status in South Asian adults: implications for targeted guidance on sun exposure.

    Science.gov (United States)

    Farrar, Mark D; Webb, Ann R; Kift, Richard; Durkin, Marie T; Allan, Donald; Herbert, Annie; Berry, Jacqueline L; Rhodes, Lesley E

    2013-06-01

    Vitamin D is essential for bone health, and cutaneous synthesis is an important source. South Asians cannot attain adequate amounts of vitamin D by following general recommendations on summer sunlight exposure at northerly latitudes, and increased exposure may be appropriate for improving their vitamin D status. We examined the efficacy of a dose range of simulated summer sunlight exposures in raising vitamin D status in UK adults of South Asian ethnicity. In a dose-response study, healthy adults of South Asian ethnicity (n = 60; 20-60 y old) received 1 of 6 ultraviolet exposures ranging from 0.65 to 3.9 standard erythema doses (SEDs), which were equivalent to 15-90 min unshaded noontime summer sunlight at 53.5°N (Manchester, United Kingdom), 3 times/wk for 6 wk, while wearing casual clothes that revealed a 35% skin area. Serum 25-hydroxyvitamin D [25(OH)D] was measured weekly, and dietary vitamin D was estimated. At baseline, all completing participants (n = 51) were vitamin D insufficient [25(OH)D concentrations exposures ≥1.95 SEDs (equivalent to 45 min unshaded sunlight; n = 33) attained a mean (±SD) 25(OH)D concentration of 15.7 ± 5 ng/mL (mean rise: 8.7 ± 5.7 ng/mL; 95% CI: 6.8, 10.6 ng/mL; P 10 ng/mL. Targeted guidance on sunlight exposure could usefully enhance vitamin D status to avoid deficiency [25(OH)D concentration >10 ng/mL] in South Asians living at latitudes distant from the equator. This trial was registered at the ISRCTN Register (www.isrctn.org) as 07565297.

  5. Sunlight exposure and cutaneous human papillomavirus seroreactivity in basal cell and squamous cell carcinomas of the skin.

    Science.gov (United States)

    Iannacone, Michelle R; Wang, Wei; Stockwell, Heather G; O'Rourke, Kathleen; Giuliano, Anna R; Sondak, Vernon K; Messina, Jane L; Roetzheim, Richard G; Cherpelis, Basil S; Fenske, Neil A; Michael, Kristina M; Waterboer, Tim; Pawlita, Michael; Rollison, Dana E

    2012-08-01

    Ultraviolet radiation exposure may interact synergistically with cutaneous human papillomavirus (HPV) infection in the development of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin. To investigate differences in the risk of sunlight-associated BCC and SCC by cutaneous genus-specific HPV serostatus, a case-control study was conducted among 204 BCC and 156 SCC cases who were recruited from a university dermatology clinic and 297 controls who had no history of cancer and screened negative for current skin cancer. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between measures of sunlight exposure and BCC/SCC, stratified by genus-specific HPV serostatus, with adjustment for age and sex. Sunburn due to cutaneous sensitivity to sunlight exposure (P = .006) and poor tanning ability (P = .003) were associated with a higher seroprevalence for genus beta HPV types. Poor or no tanning ability was more strongly associated with SCC among individuals who were seropositive for antibodies to cutaneous HPV types in genera alpha (OR, 15.60; 95% CI, 5.40-45.1; P = .01 for interaction) and beta (OR, 6.86; 95% CI, 3.68-12.80; P = .001 for interaction), compared with individuals who were seronegative for these HPV types. Seropositivity for HPV types in genera alpha or beta increased the risk of SCC associated with poor tanning ability.

  6. Commonly recommended daily intake of vitamin D is not sufficient if sunlight exposure is limited

    DEFF Research Database (Denmark)

    Glerup, H; Mikkelsen, K; Poulsen, L

    2000-01-01

    intake analysis to estimate the oral intake of vitamin D necessary to keep a normal vitamin D status in sunlight-deprived individuals. DESIGN: Cross-sectional study amongst randomly selected Moslem women of Arab origin living in Denmark. Age-matched Danish women were included as controls. To control...

  7. Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin – a case–control study

    Directory of Open Access Journals (Sweden)

    Iannacone Michelle R

    2012-09-01

    Full Text Available Abstract Background Non-melanoma skin cancer (NMSC, comprised of basal (BCC and squamous (SCC cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. Methods A case–control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous and timing (childhood vs. adulthood of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. Results A history of blistering sunburn (a measure of intermittent sunlight exposure was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03 and SCC (OR = 2.02, 95% CI = 1.22-3.33. Additionally, having a job in the sun for ≥3 months for 10 years or longer (a measure of continuous sunlight exposure was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Conclusions Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous. The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC.

  8. Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin--a case-control study.

    Science.gov (United States)

    Iannacone, Michelle R; Wang, Wei; Stockwell, Heather G; O'Rourke, Kathleen; Giuliano, Anna R; Sondak, Vernon K; Messina, Jane L; Roetzheim, Richard G; Cherpelis, Basil S; Fenske, Neil A; Rollison, Dana E

    2012-09-20

    Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. A case-control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥ 3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC.

  9. Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin – a case–control study

    Science.gov (United States)

    2012-01-01

    Background Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. Methods A case–control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. Results A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Conclusions Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC. PMID:22994655

  10. Randomized Control Trial Assessing Impact of Increased Sunlight Exposure versus Vitamin D Supplementation on Lipid Profile in Indian Vitamin D Deficient Men.

    Science.gov (United States)

    Patwardhan, Vivek G; Mughal, Zulf M; Padidela, Raja; Chiplonkar, Shashi A; Khadilkar, Vaman V; Khadilkar, Anuradha V

    2017-01-01

    Despite abundance of sunshine in India, Vitamin D deficiency is common and therefore there is an increasing trend toward taking Vitamin D supplements either as prescription medicine or as a nutritional supplement. Studies have suggested that duration of sun exposure may influence serum lipid profile. To study the effect of increased sunlight exposure versus Vitamin D supplementation on Vitamin D status and lipid profile in individuals with Vitamin D deficiency (25-hydroxyvitamin-D [25OHD] 50 nmol/L, n = 50) and intervention (sunlight exposure group" (n = 50, received at least 20 min sunlight exposure to forearms and face between 11 a.m. and 3 p.m. over and above their current exposure) or "cholecalciferol supplement group" (n = 50, received oral cholecalciferol 1000 IU/day). Significant increase in 25OHD concentrations was seen in both intervention groups (P sunlight exposure (P sunlight exposure significantly reduced TC, LDL-C, and HDL-C concentrations, and cholecalciferol supplementation increased TC and HDL-C concentrations.

  11. Photosensitized mefloquine induces ROS-mediated DNA damage and apoptosis in keratinocytes under ambient UVB and sunlight exposure.

    Science.gov (United States)

    Yadav, Neera; Dwivedi, Ashish; Mujtaba, Syed Faiz; Verma, Ankit; Chaturvedi, Rajnish; Ray, Ratan Singh; Singh, Gajendra

    2014-10-01

    The present study illustrates the photosensitizing behavior of mefloquine (MQ) in human skin keratinocytes under ambient doses of UVB and sunlight exposure. Photochemically, MQ generated reactive oxygen species superoxide radical, hydroxyl radical, and singlet oxygen through type I and type II photodynamic reactions, respectively, which caused photooxidative damage to DNA and formed localized DNA lesions cyclobutane pyrimidine dimers. Photosensitized MQ reduced the viability of keratinocytes to 25 %. Significant level of intracellular reactive oxygen species (ROS) generation was estimated through fluorescence probe DCF-H2. Increased apoptotic cells were evident through AO/EB staining and phosphatidyl serine translocation in cell membrane. Single-stranded DNA damage was marked through single-cell gel electrophoresis. Mitochondrial membrane depolarization and lysosomal destabilization were evident. Upregulation of Bax and p21 and downregulation of Bcl-2 genes and corresponding protein levels supported apoptotic cell death of keratinocyte cells. Cyclobutane pyrimidine dimers (CPDs) were confirmed through immunofluorescence. In addition, hallmarks of apoptosis and G2/M phase cell cycle arrest were confirmed through flow cytometry analysis. Our findings suggest that MQ may damage DNA and produce DNA lesions which may induce differential biological responses in the skin on brief exposure to UVB and sunlight.

  12. Effect of grape bunch sunlight exposure and UV radiation on phenolics and volatile composition of Vitis vinifera L. cv. Pinot noir wine.

    Science.gov (United States)

    Song, Jianqiang; Smart, Richard; Wang, Hua; Dambergs, Bob; Sparrow, Angela; Qian, Michael C

    2015-04-15

    The effect of canopy leaf removal and ultraviolet (UV) on Pinot noir grape and wine composition was investigated in this study. Limited basal leaf removal in the fruit zone was conducted, compared to shaded bunches. The UV exposure was controlled using polycarbonate screens to block UV radiation, and acrylic screens to pass the UV. The results showed that bunch sunlight and UV exposure significantly increased the Brix and pH in the grape juice, and increased substantially wine colour density, anthocyanins, total pigment, total phenolics and tannin content. Bunch sunlight and UV exposure affected terpene alcohols, C13-norisprenoids and other volatile composition of the wine differently. Sunlight exposure and UV resulted in increase of nerol, geraniol and citronellol but not linalool. Sunlight exposure slightly increased the concentration of β-ionone, but the increase was not statistically significant for UV treatment. Neither sunlight nor UV treatment showed any impact on the concentration of β-damascenone. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Sunlight exposure may be a risk factor of hearing impairment: a community-based study in Japanese older men and women.

    Science.gov (United States)

    Michikawa, Takehiro; Nishiwaki, Yuji; Asakura, Keiko; Hillebrand, Greg; Miyamoto, Kukizo; Ono, Masaji; Kinjo, Yoshihide; Akiba, Suminori; Takebayashi, Toru

    2013-01-01

    Oxidative stress is an important factor in the pathology of age-related hearing loss. Recent animal studies have reported that ultraviolet radiation in sunlight is related to systemic induction of oxidative stress. Chronic sun exposure leads to photodamaged skin, which is manifested as facial skin wrinkling and hyperpigmentation. We hypothesized that sunlight exposure, as assessed by the severity of facial skin photodamage, might be associated with hearing impairment through an oxidative stress mechanism. To examine this, we performed a cross-sectional analysis by using the baseline data from a community-based cohort study of older Japanese. A total of 805 residents (342 men and 463 women) aged 65 years or older living in Kurabuchi Town, Gunma prefecture, Japan, were examined between 2005 and 2006. Facial skin condition was quantified by image analysis of standardized facial images. Hearing impairment was defined as a failure to hear a 30-dB signal at 1 kHz and a 40-dB signal at 4 kHz in the better ear in pure-tone audiometric tests. In men, facial wrinkle was positively associated with hearing impairment (for highest vs lowest: multivariate-adjusted odds ratio, 2.16; 95% confidence interval, 1.00-4.66; p for trend = .01). Stratified analysis by age, educational level, smoking status, sunscreen or foundation use, and diabetes showed results similar to those for men as a whole. This association was particularly pronounced in men with the low levels of antioxidants and without occupational noise exposure. We observed no apparent association in women. The results support the hypothesis that chronic sun exposure is a risk factor of hearing impairment.

  14. Anatomical exposure patterns of skin to sunlight: relative contributions of direct, diffuse and reflected ultraviolet radiation.

    Science.gov (United States)

    Vernez, D; Milon, A; Vuilleumier, L; Bulliard, J-L

    2012-08-01

    The dose-response between ultraviolet (UV) exposure patterns and skin cancer occurrence is not fully understood. Sun-protection messages often focus on acute exposure, implicitly assuming that direct UV radiation is the key contributor to the overall UV exposure. However, little is known about the relative contribution of the direct, diffuse and reflected radiation components. To investigate solar UV exposure patterns at different body sites with respect to the relative contribution of the direct, diffuse and reflected radiation. A three-dimensional numerical model was used to assess exposure doses for various body parts and exposure scenarios of a standing individual (static and dynamic postures). The model was fed with erythemally weighted ground irradiance data for the year 2009 in Payerne, Switzerland. A year-round daily exposure (08:00-17:00 h) without protection was assumed. For most anatomical sites, mean daily doses were high (typically 6.2-14.6 standard erythemal doses) and exceeded the recommended exposure values. Direct exposure was important during specific periods (e.g. midday during summer), but contributed moderately to the annual dose, ranging from 15% to 24% for vertical and horizontal body parts, respectively. Diffuse irradiation explained about 80% of the cumulative annual exposure dose. Acute diffuse exposures were also observed during cloudy summer days. The importance of diffuse UV radiation should not be underestimated when advocating preventive measures. Messages focused on avoiding acute direct exposures may be of limited efficiency to prevent skin cancers associated with chronic exposure. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

  15. A case-control study of occupational sunlight exposure and renal cancer risk.

    Science.gov (United States)

    Karami, Sara; Colt, Joanne S; Stewart, Patricia A; Schwartz, Kendra; Davis, Faith G; Ruterbusch, Julie J; Chow, Wong-Ho; Wacholder, Sholom; Graubard, Barry I; Purdue, Mark P; Moore, Lee E

    2016-04-01

    Epidemiological evidence of a relationship between vitamin D and kidney cancer risk has been inconsistent despite experimental data indicating that vitamin D and its metabolites may inhibit carcinogenesis. Previously we reported an inverse association between renal cell carcinoma (RCC) risk and occupational ultraviolet (UV) exposure among European men. In this study, we examined the association between occupational UV exposure and RCC risk among US residents and investigated whether this association varied by race and sex. Lifetime occupational data for 1,217 RCC cases and 1,235 controls in a population-based case-control study, conducted from 2002 to 2007, were assessed for occupational UV exposure. We evaluated exposure metrics in quartiles based on control exposure levels and calculated associations between RCC risk and occupational UV exposure using unconditional logistic regression adjusted for sex, race, body mass index, smoking, hypertension, center, education, family history of cancer and dietary vitamin D intake. A general pattern of decreasing RCC risk with increasing UV exposure was observed. Cases had significantly lower cumulative occupational UV exposure than controls (fourth quartile vs. first: odds ratio = 0.74 [95% confidence interval = 0.56-0.99], p-trend = 0.03). Similar results were observed for other UV exposure metrics. The association with occupational UV exposure was stronger for women than for men, but did not differ by race. Our findings suggest an inverse association between occupational UV exposure and RCC, particularly among women. Given the sex finding discrepancies in this study versus our previous study, additional research is need to clarify whether the protective effects of occupational UV exposure and RCC risk are real. © 2015 UICC.

  16. Degradation of the pesticide carbofuran on clay and soil surfaces upon sunlight exposure.

    Science.gov (United States)

    Mountacer, H; Atifi, A; Wong-Wah-Chung, P; Sarakha, M

    2014-03-01

    In the present study, the photolysis of carbofuran has been undertaken under sunlight conditions and at the surface of model supports such as clay films and different soils collected from two different sites in Morocco (Tirs and Dahs). In all conditions, an efficient degradation occurred owing to direct light absorption and also to photoinduced processes involving either clays or natural organic matter moities. On kaolin films, the photodegradation kinetics appears to follow a first-order process that clearly depends on the film thickness. The diffusion of carbofuran from the lower part to the illuminated surface was found to be negligible when compared to the photolysis process within the range of 20-70 μm. Thus, the photolysis rate constant at the surface of the solid support, k (0), was evaluated to be 7.0 × 10(-3) min(-1). Under these experimental conditions, the quantum yield was found equal to 2.1 × 10(-4). On soil surfaces, the disappearance rate constant was mainly attributed to photoinduced processes arising from natural organic matter. From the analytical point of view, the products were formed through (1) hydroxylation on the aromatic ring, (2) homolytic scission of the carbamate C-O bond leading to radical species formation, and (3) photohydrolysis of the carbamate C-O bond.

  17. Psychosocial aspects associated with use of sunscreen, natural sunlight exposure, and artificial tanning.

    Science.gov (United States)

    Ventenilla, Jessica; França, Katlein; Lotti, Torello; Keri, Jonette

    2017-02-08

    Natural and artificial tanning have become very popular in Western culture, yet at the same time, there is still a psychodermatology concern for this activity. Not much has been examined with the psychological aspects of tanning and sunscreen use. The purpose of this study is to examine the psychosocial effects associated with sun protection, natural, and artificial tanning among individuals 18 years old or older visiting the University of Miami Dermatology Outpatient Clinic. We distributed a survey on tanning and sunscreen use to 150 dermatology outpatients, hospital employees, and hospital visitors for three weeks during June/July 2015 asking about how often they tan, use sunscreen, and how they feel about this topic. Demographics, such as gender, ethnicity, and education were taken into consideration to examine the different responses in each category. Our results suggest that people's perception to tanning and sunscreen use have evolved over time. Most people in South Florida nowadays feel guilty when exposed to natural sunlight without sunscreen and do not tan frequently. The majority of the people, specifically women, utilize the recommended amount of sunscreen with a sun protection factor of 30-50. However, we can conclude that communication between social media and the general public can affect people's decision-making on tanning and sunscreen use with physician advice being the most effective method of encouraging people to use sunscreen. This study will add to the growing knowledge about psychodermatology.

  18. Effect of preadmission sunlight exposure on intensive care unit-acquired delirium: a multicenter study

    NARCIS (Netherlands)

    Simons, K.S.; Workum, J.D.; Slooter, A.J.; Boogaard, M.H.W.A. van den; Hoeven, J.G. van der; Pickkers, P.

    2014-01-01

    PURPOSE: It is assumed that there is a relation between light exposure and delirium incidence. The aim of our study was to determine the effect of prehospital light exposure on the incidence of intensive care unit (ICU)-acquired delirium. MATERIALS AND METHODS: Data from 3 ICUs in the Netherlands we

  19. Sunlight exposure and photoprotection behaviour of white Caucasian adolescents in the UK.

    Science.gov (United States)

    Gould, M; Farrar, M D; Kift, R; Berry, J L; Mughal, M Z; Bundy, C; Vail, A; Webb, A R; Rhodes, L E

    2015-04-01

    Sun exposure has positive and negative effects on health, yet little is known about the sun exposure behaviour of UK adolescents, including those more prone or less prone to sunburn. To examine sun exposure behaviour of UK white Caucasian adolescents including time spent outdoors, holiday behaviour, use of sunscreen and clothing, with assessment for differences between sun-reactive skin type groups. White Caucasian adolescents (12-15 years) attending schools in Greater Manchester completed a two-page questionnaire to assess sun exposure and photoprotective behaviour. A total of 133 adolescents (median age 13.4 years; 39% skin type I/II, 61% skin type III/IV) completed the questionnaire. In summer, adolescents spent significantly longer outdoors at weekends (median 4 h/day, range 0.25-10) than on weekdays (2, 0.25-6; P exposure behaviour/protection between males and females. The greater sun-protective measures reported by adolescents of sun-reactive skin type group I/II than III/IV suggest those who burn more easily are aware of the greater need to protect their skin. However, use of sunscreen during the UK summer is low and may need more effective promotion in adolescents. © 2014 European Academy of Dermatology and Venereology.

  20. Accelerated 20-year sunlight exposure simulation of a photochromic foldable intraocular lens in a rabbit model

    Science.gov (United States)

    Werner, Liliana; Abdel-Aziz, Salwa; Peck, Carolee Cutler; Monson, Bryan; Espandar, Ladan; Zaugg, Brian; Stringham, Jack; Wilcox, Chris; Mamalis, Nick

    2011-01-01

    PURPOSE To assess the long-term biocompatibility and photochromic stability of a new photochromic hydrophobic acrylic intraocular lens (IOL) under extended ultraviolet (UV) light exposure. SETTING John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN Experimental study. METHODS A Matrix Aurium photochromic IOL was implanted in right eyes and a Matrix Acrylic IOL without photochromic properties (n = 6) or a single-piece AcrySof Natural SN60AT (N = 5) IOL in left eyes of 11 New Zealand rabbits. The rabbits were exposed to a UV light source of 5 mW/cm2 for 3 hours during every 8-hour period, equivalent to 9 hours a day, and followed for up to 12 months. The photochromic changes were evaluated during slitlamp examination by shining a penlight UV source in the right eye. After the rabbits were humanely killed and the eyes enucleated, study and control IOLs were explanted and evaluated in vitro on UV exposure and studied histopathologically. RESULTS The photochromic IOL was as biocompatible as the control IOLs after 12 months under conditions simulating at least 20 years of UV exposure. In vitro evaluation confirmed the retained optical properties, with photochromic changes observed within 7 seconds of UV exposure. The rabbit eyes had clinical and histopathological changes expected in this model with a 12-month follow-up. CONCLUSIONS The new photochromic IOL turned yellow only on exposure to UV light. The photochromic changes were reversible, reproducible, and stable over time. The IOL was biocompatible with up to 12 months of accelerated UV exposure simulation. PMID:21241924

  1. Positive Association between Blood 25-Hydroxyvitamin D Levels and Pterygium after Control for Sunlight Exposure.

    Science.gov (United States)

    Jee, Donghyun; Kim, Eun Chul; Cho, Eunyoung; Arroyo, Jorge G

    2016-01-01

    To investigate the association between blood 25-hydroxyvitamin D levels and pterygium. Korean National Health and Nutrition Examination Survey 2008-2011 were used for the present epidemiologic study. A total of 19,178 participants aged ≥ 30 years were evaluated for blood 25-hydroxyvitamin D levels and performed ophthalmic slit lamp examinations. Pterygium was considered as a growth of fibrovascular tissue over the cornea. The average blood 25-hydroxyvitamin D levels were 18.6 ng/mL, and prevalence of pterygium was 6.5%. The odds of pterygium significantly increased across blood 25-hydroxyvitamin D quintiles after controlling sun exposure time as well as other confounders such as sex, age, smoking, diabetes, hypertension (P exposure time, we found a positive association between blood 25-hydroxyvitamin D levels and pterygium in a representative Korean population. The mechanism underlying this association is unknown.

  2. Estimation of exposure to sunlight of the liner under a tiled roof

    DEFF Research Database (Denmark)

    Holck, Ole; Rosenfeld, J.L.J.

    2005-01-01

    and strike the liner, accelerating its degradation. The purpose of this study is to estimate the extent and duration of the exposure. A typical gap is modelled in a ray-tracing program and the size and position of the illuminated area on the liner is calculated for given directions of the light beam relative...... to the roof. Analytic expressions for the size of the illuminated area are obtained using a thick slit model. The accuracy of the model was assessed by some experimental measurements. The exposure over one year of the roof liner was calculated using the Design Reference Year for Copenhagen, Denmark....... Simulations were carried out for a roof tilted at 25degrees, 35degrees or 45degrees, facing SE, S, SW or W. For the particular roof construction and gap studied, the maximum annual exposure of a 25 mm(2) piece of the liner placed 150 mm below the gap (corresponding to about 100 mm below the base of the tiles...

  3. 40 CFR 795.70 - Indirect photolysis screening test: Sunlight photolysis in waters containing dissolved humic...

    Science.gov (United States)

    2010-07-01

    ... mobile phase is 2 percent acetic acid, 50 percent acetonitrile and 48 percent water (2 mL/min flow rate... of sunlight actinometers.” Environmental Science and Technology, 6:815. (1982). (6) Haag H.R., Hoigne... Science and Technology, 11:359. (1977). (20) Zepp, R.G., Wolfe N.L., Baughman G.L., Hollis R.C....

  4. Co-exposure to sunlight enhances the toxicity of naturally weathered Deepwater Horizon oil to early lifestage red drum (Sciaenops ocellatus) and speckled seatrout (Cynoscion nebulosus).

    Science.gov (United States)

    Alloy, Matthew; Garner, Thomas Ross; Bridges, Kristin; Mansfield, Charles; Carney, Michael; Forth, Heather; Krasnec, Michelle; Lay, Claire; Takeshita, Ryan; Morris, Jeffrey; Bonnot, Shane; Oris, James; Roberts, Aaron

    2017-03-01

    The 2010 Deepwater Horizon oil spill resulted in the accidental release of millions of barrels of crude oil into the Gulf of Mexico. Photo-induced toxicity following co-exposure to ultraviolet (UV) radiation is 1 mechanism by which polycyclic aromatic hydrocarbons (PAHs) from oil spills may exert toxicity. Red drum and speckled seatrout are both important fishery resources in the Gulf of Mexico. They spawn near-shore and produce positively buoyant embryos that hatch into larvae in approximately 24 h. The goal of the present study was to determine whether exposure to UV as natural sunlight enhances the toxicity of crude oil to early lifestage red drum and speckled seatrout. Larval fish were exposed to several dilutions of high-energy water-accommodated fractions (HEWAFs) from 2 different oils collected in the field under chain of custody during the 2010 spill and 3 gradations of natural sunlight in a factorial design. Co-exposure to natural sunlight and oil significantly reduced larval survival compared with exposure to oil alone. Although both species were sensitive at PAH concentrations reported during the Deepwater Horizon spill, speckled seatrout demonstrated a greater sensitivity to photo-induced toxicity than red drum. These data demonstrate that even advanced weathering of slicks does not ameliorate the potential for photo-induced toxicity of oil to these species. Environ Toxicol Chem 2017;36:780-785. © 2016 SETAC. © 2016 SETAC.

  5. The impact of natural sunlight exposure on the UVB-sun protection factor (UVB-SPF) and UVA protection factor (UVA-PF) of a UVA/UVB SPF 50 sunscreen.

    Science.gov (United States)

    Stephens, Thomas J; Herndon, James H; Colón, Luz E; Gottschalk, Ronald W

    2011-02-01

    To compare the functional stability of Cetaphil UVA/UVB Defense SPF 50 as measured by its ultraviolet B sun protection factor (UVB-SPF) and ultraviolet A protection factor (UVA-PF) values following exposure to natural sunlight versus the UVB-SPF and UVA-PF values of unexposed product. These two randomized, controlled, evaluator-blinded, single-center trials were conducted according to the methods outlined in the 2007 Proposed Amendment to the Final Monograph, “Sunscreen Drug Products for Over-the-Counter Human Use.” Sunscreen samples were applied to glass plates and exposed to ultraviolet radiation in the form of natural sunlight in four minimal erythemal doses (MED) ranging from 2–6 MED (42–36 mJ/cm2). Three test sites were identified on the back of each study subject. Exposed sunscreen (one of four doses), unexposed sunscreen, and a UVB-SPF 15 control sunscreen were applied to the three test sites in a randomized fashion, followed by UV irradiation of incremental doses. Erythema and pigment darkening responses were assessed immediately following UV exposure and again 16–24 hours (erythema) or three to 24 hours (pigment darkening) after exposure. UVB-SPF and UVA-PF values were calculated for the exposed and unexposed samples. The calculated UVB-SPF and UVA-PF values for all test samples (exposed and unexposed) were >50 and >9, respectively, which were greater than the stated UVB-SPF and UVA-PF values on the product label. No differences were observed between the exposed and unexposed samples in UVB-SPF or UVA-PF. The UVA and UVB protection using standard evaluation techniques of Cetaphil UVA/UVB Defense SPF 50 remains stable despite exposure of the sunscreen to natural sunlight containing UVB ranging from 2–16 MED (41–336 mJ/cm2) and coexistent UVA.

  6. Test of a device for accelerated ageing of polymeric material in high concentrated sunlight at the DLR solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Witzke, A.; Neumann, A.; Kaluza, J. [German Aerospace Center (DLR), Solar Energy Technology, Cologne (Germany); Demuth, M.; Ritterskamp, P. [Max-Planck-Inst. fuer Strahlenchemie, Muelheim a.d.R. (Germany)

    2001-07-01

    Within this study the design and first tests of a device for accelerated ageing with high concentrated sunlight have been described. Firstly, the device was designed for testing samples of lacquer for the car industry. It is based on two points: first, the photochemical effect that the ageing of polymers is mainly initiated by the UV solar radiation and, second, on the idea to accelerate the ageing process by increasing the UV radiation dose. Therefore the concentrated sunlight at the DLR Solar Furnace is filtered by a cold-mirror that reflects the radiation with a wavelength below 450 nm onto the samples. The samples are fixed in a chamber where they can simultaneously be wetted by a spraying device. The first tests show that this device enables us to radiate the relevant samples with a high UV radiation intensity without overheating them. During one day irradiation at the DLR Solar Furnace in March 2001 we reach an UV radiation dose which is about sixteen times higher than the dose after 24 hours irradiation in common used weathering devices. Further tests at the DLR Solar Furnace have to examine in what way this increased radiation dose leads to a high accelerated ageing of the polymeric material. (orig.)

  7. Use of Uniformly Distributed Concentrated Sunlight for Highly Accelerated Testing of Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.; Bingham, C.; King, D.; Lewandowski, A.; Netter, J.; Terwilliger, K.; Adamsons, K.

    2000-12-14

    NREL has developed a new ultraviolet (UV) light concentrator that allows material samples to be subjected to uniform intensity levels of 50-100X solar UV at closely controlled sample exposure temperatures. In collaboration with industry, representative coating systems have been exposed without introducing unrealistic degradation mechanisms. Furthermore, correlations have been derived between these highly accelerated test conditions and results obtained at 1-2 suns. Such information is used to predict the degradation of materials in real-world applications. These predictions are compared with measured in-service performance losses to validate the approach. This allows valuable information to be obtained in greatly reduced timeframes, which can provide tremendous competitive advantage in the commercial marketplace.

  8. Identification of MicroRNAs and Their Targets Associated with Fruit-Bagging and Subsequent Sunlight Re-exposure in the "Granny Smith" Apple Exocarp Using High-Throughput Sequencing

    National Research Council Canada - National Science Library

    Qu, Dong; Yan, Fei; Meng, Rui; Jiang, Xiaobing; Yang, Huijuan; Gao, Ziyi; Dong, Yonghui; Yang, Yazhou; Zhao, Zhengyang

    2016-01-01

    ...) in response to debagging. Three small RNA libraries were primarily constructed from peels of "Granny Smith" apples subjected to bagging followed by sunlight re-exposure treatments (0, 6 h, 1 day) (debagging...

  9. Modifiable risk factors including sunlight exposure and fish consumption are associated with risk of hypertension in a large representative population from Macau.

    Science.gov (United States)

    Ke, Liang; Ho, Jacky; Feng, Jianzhang; Mpofu, Elias; Dibley, Michael J; Feng, Xiuhua; Van, Florance; Leong, Sokman; Lau, Winne; Lueng, Petra; Kowk, Carrie; Li, Yan; Mason, Rebecca S; Brock, Kaye E

    2014-10-01

    Chinese populations are known to be at risk for vitamin D deficiency, with some evidence that this is due to lack of exposure to sunlight. Vitamin D deficiency and/or low sun exposure have been associated with higher incidence of hypertension in Caucasians. Thus, we investigated these associations in a Chinese population with a high rate of hypertension. From a random household survey of 1410 residents aged ≥18 years, height, weight and blood pressure were measured and demographic, exercise and dietary data were collected, as well as estimated hours of sunlight exposure on weekdays and weekends (in winter and summer). Modifiable predictors of hypertension in these data were lack of sunlight exposure and low intake of fish as well as smoking, obesity and lack of exercise. When investigated in a linear model, sunlight exposure was negatively associated with hypertension (β=-0.072, pexposure per day compared to none was associated with less hypertension (OR=0.6, 95% CI: 0.4-0.8). Similarly, consuming either oily fish or seafood more than four times per week compared to less was also associated with less hypertension (oily fish (OR=0.4, 95% CI: 0.3-0.5); seafood consumption (OR=0.8, 95% CI: 0.7-0.9)). Having daily moderate physical activity compared to none was also associated with a lower risk of hypertension (OR=0.8, 95% CI: 0.7-0.9). In contrast, being obese compared to normal weight and having more than five pack-years of smoking compared to none were associated with a higher risk of hypertension (OR=4.6, 95% CI: 3.7-5.7; OR=1.4, 95% CI: 1.0-1.8, respectively). The major new findings of this study are that more sun exposure and high weekly fish consumption (especially oily fish) may be potentially modifiable independent factors for protecting against risk of hypertension in this population. This article is part of a Special Issue entitled '16th Vitamin D Workshop'. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Vitamin D status in postmenopausal women living at higher latitudes in the UK in relation to bone health, overweight, sunlight exposure and dietary vitamin D.

    Science.gov (United States)

    Macdonald, Helen M; Mavroeidi, Alexandra; Barr, Rebecca J; Black, Alison J; Fraser, William D; Reid, David M

    2008-05-01

    For 5 months a year the UK has insufficient sunlight for cutaneous synthesis of vitamin D and winter requirements are met from stores made the previous summer. Although there are few natural dietary sources, dietary intake may help maintain vitamin D status. We investigated the relationship between 25-hydroxyvitamin D (25(OH)D), bone health, overweight, sunlight exposure and dietary vitamin D in 3113 women (age 54.8 [SD 2.3] years) living at latitude 57 degrees N between 1998-2000. Serum 25(OH)D was measured by high performance liquid chromatography (HPLC), dietary intakes (food frequency questionnaire, n=2598), sunlight exposure (questionnaire, n=2402) and bone markers were assessed. Bone mineral density (BMD) was measured by dual x-ray absorptiometry in all women at the sampling visit and 6 years before. Seasonal variation in 25(OH)D was not substantial with a peak in the autumn (23.7 [9.9] ng/ml) and a nadir in spring (19.7 [7.6] ng/ml). Daily intake of vitamin D was 4.2 [2.5] mug from food only and 5.8 [4.0] mug including vitamin D from cod liver oil and multivitamins. The latter was associated with 25(OH)D at each season whereas vitamin D simply from food was associated with 25(OH)D in winter and spring only. Sunlight exposure was associated with 25(OH)D in summer and autumn. 25(OH)D was negatively associated with increased bone resorption and bone loss (Pbone resorption markers in the upper category (fDPD/Cr 5.1 [1.7] nmol/mmol compared to 5.3 [2.1] nmol/mmol, P=0.03) and no difference in BMD or bone loss. 25(OH)D was lower (Pvitamin D status is associated with greater bone turnover, bone loss and obesity. Diet appears to attenuate the seasonal variation of vitamin D status in early postmenopausal women at northerly latitude where quality of sunlight for production of vitamin D is diminished.

  11. Effect of sunlight-exposure on antioxidants and antioxidant enzyme activities in 'd'Anjou' pear in relation to superficial scald development.

    Science.gov (United States)

    Zhao, Jing; Xie, Xingbin; Shen, Xiang; Wang, Yan

    2016-11-01

    Influence of preharvest sunlight exposure on superficial scald development in 'd'Anjou' pears during cold storage was investigated. The biochemical changes related to scald including α-farnesene, conjugated trienols (CTols), antioxidants, antioxidant enzyme activities were monitored among separated blushed and shaded peels of unbagged fruit as well as the whole peel of bagged fruit. In unbagged fruit, scald symptom was restricted to shaded peel; while there was no difference in α-farnesene between blushed and shaded peels, CTols increased significantly in shaded peel along with scald development after 3months storage. Bagging treatment increased both α-farnesene and CTols significantly and enhanced scald. Preharvest sunlight exposure significantly increased certain antioxidant contents and antioxidant enzyme activities in blushed peel at harvest and during storage. These results reveal a direct role of CTols during development of scald, however, antioxidant systems may play an important role in α-farnesene oxidation to CTols and scald susceptibility in 'd'Anjou pears. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Recommended summer sunlight exposure levels can produce sufficient (> or =20 ng ml(-1)) but not the proposed optimal (> or =32 ng ml(-1)) 25(OH)D levels at UK latitudes.

    Science.gov (United States)

    Rhodes, Lesley E; Webb, Ann R; Fraser, Heather I; Kift, Richard; Durkin, Marie T; Allan, Donald; O'Brien, Sarah J; Vail, Andy; Berry, Jacqueline L

    2010-05-01

    Recommendations on limitation of summer sunlight exposure to prevent skin cancer may conflict with requirements to protect bone health through adequate vitamin D levels, the principal source being UVB in summer sunlight. We determined whether sufficient (> or =20 ng ml(-1)) and proposed optimal (> or =32 ng ml(-1)) 25(OH)D levels are attained by following UK guidance advising casual short exposures to UVB in summer sunlight, and performed the study under known conditions to enhance the specificity of future recommendations. During wintertime, when ambient UVB is negligible, 120 white Caucasians, aged 20-60 years, from Greater Manchester, UK (53.5 degrees N) received a simulated summer's sunlight exposures, specifically 1.3 standard erythemal dose, three times weekly for 6 weeks, while wearing T-shirt and shorts. The baseline winter data predict that 5% (confidence interval (CI): 2.7-8.6) of Greater Manchester white Caucasians have deficient (exposures, 90 (CI: 84.9-93.7) and 26.2% (CI: 20.1-33.2) reached 20 and 32 ng ml(-1) 25(OH)D, respectively. Assuming midday UVB levels, sufficient but suboptimal vitamin D status is attained after a summer's short (13 minutes) sunlight exposures to 35% skin surface area; these findings will assist future public health guidance on vitamin D acquisition.

  13. Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1986-01-01

    1.1 This test method covers the measurement of solar transmittance (terrestrial) of materials in sheet form by using a pyranometer, an enclosure, and the sun as the energy source. 1.2 This test method also allows measurement of solar transmittance at angles other than normal incidence. 1.3 This test method is applicable to sheet materials that are transparent, translucent, textured, or patterned. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  14. Effect of sunlight exposure on the release of intentionally and/or non-intentionally added substances from polyethylene terephthalate (PET) bottles into water: chemical analysis and in vitro toxicity.

    Science.gov (United States)

    Bach, Cristina; Dauchy, Xavier; Severin, Isabelle; Munoz, Jean-François; Etienne, Serge; Chagnon, Marie-Christine

    2014-11-01

    The effect of sunlight exposure on chemical migration into PET-bottled waters was investigated. Bottled waters were exposed to natural sunlight for 2, 6 and 10 days. Migration was dependent on the type of water. Formaldehyde, acetaldehyde and Sb migration increased with sunlight exposure in ultrapure water. In carbonated waters, carbon dioxide promoted migration and only formaldehyde increased slightly due to sunlight. Since no aldehydes were detected in non-carbonated waters, we conclude that sunlight exposure has no effect. Concerning Sb, its migration levels were higher in carbonated waters. No unpredictable NIAS were identified in PET-bottled water extracts. Cyto-genotoxicity (Ames and micronucleus assays) and potential endocrine disruption effects (transcriptional-reporter gene assays) were checked in bottled water extracts using bacteria (Salmonella typhimurium) and human cell lines (HepG2 and MDA-MB453-kb2). PET-bottled water extracts did not induce any toxic effects (cyto-genotoxicity, estrogenic or anti-androgenic activity) in vitro at relevant consumer-exposure levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Can breakfast tryptophan and vitamin B6 intake and morning exposure to sunlight promote morning-typology in young children aged 2 to 6 years?

    Directory of Open Access Journals (Sweden)

    Nakade Miyo

    2012-05-01

    Full Text Available Abstract This study tried to examine, from epidemiological and physiologic anthropological (Japanese culture on breakfast points of view, the integrated effects of the amount of tryptophan and vitamin B6 intake and the following exposure to sunlight on the circadian typology and sleep habits in young Japanese children aged 2 to 6 years, using the newly-evaluated calculating system of tryptophan (Tryptophan Index 2009 and vitamin B6 intake (VitaminB6 Index 2009 at breakfast. The positive and significant correlation was shown between the Morningness-Eveningness (M-E score and the Tryptophan Index and also the Vitamin B6 Index. This positive correlation between M-E score and amount of tryptophan intake was shown only by children who were exposed to sunlight for longer than 10min after breakfast. These results might support the following hypothesis: higher tryptophan and vitamin B6 intake at breakfast could promote the synthesis of serotonin via light stimulation in the morning in children.

  16. Can breakfast tryptophan and vitamin B6 intake and morning exposure to sunlight promote morning-typology in young children aged 2 to 6 years?

    Science.gov (United States)

    2012-01-01

    This study tried to examine, from epidemiological and physiologic anthropological (Japanese culture on breakfast) points of view, the integrated effects of the amount of tryptophan and vitamin B6 intake and the following exposure to sunlight on the circadian typology and sleep habits in young Japanese children aged 2 to 6 years, using the newly-evaluated calculating system of tryptophan (Tryptophan Index 2009) and vitamin B6 intake (VitaminB6 Index 2009) at breakfast. The positive and significant correlation was shown between the Morningness-Eveningness (M-E) score and the Tryptophan Index and also the Vitamin B6 Index. This positive correlation between M-E score and amount of tryptophan intake was shown only by children who were exposed to sunlight for longer than 10min after breakfast. These results might support the following hypothesis: higher tryptophan and vitamin B6 intake at breakfast could promote the synthesis of serotonin via light stimulation in the morning in children. PMID:22738346

  17. [Behaviors related to sunlight exposure versus protection in a random population sample from 15 Brazilian State capitals and the Federal District, 2002-2003].

    Science.gov (United States)

    Szklo, André Salem; Almeida, Liz Maria de; Figueiredo, Valeska; Lozana, José de Azevedo; Azevedo e Silva Mendonça, Gulnar; Moura, Lenildo de; Szklo, Moysés

    2007-04-01

    This article examines region-specific relations between prevalence of protection against sunlight and socio-demographic and behavioral variables in Brazil. Data were derived from a cross-sectional population-based random sample. Information on sunlight exposure was available for a total of 16,999 individuals 15 years and older. Comparing the North and South of Brazil, crude differences between women and men in the use of "sunscreen" and "protective headwear" were +10.9% (95%CI: 7.1; 14.6) and -11.6% (95%CI: -17.0; -6.3) in the North and +21.3% (95%CI: 17.7; 24.9) and -16.0% (95%CI: -20.2; -12.5) in the South. Adjusted differences by selected variables confirmed that women use more sunscreen protection and less headwear protection as compared to men in both the North and South, but the difference was not homogeneous by region (interaction term p value < 0.05).

  18. Sunlight exposure behaviour and vitamin D status in photosensitive patients: longitudinal comparative study with healthy individuals at U.K. latitude.

    Science.gov (United States)

    Rhodes, L E; Webb, A R; Berry, J L; Felton, S J; Marjanovic, E J; Wilkinson, J D; Vail, A; Kift, R

    2014-12-01

    Low vitamin D status is prevalent in wintertime in populations at northerly latitudes. Photosensitive patients are advised to practise sun avoidance, but their sunlight exposure levels, photoprotective measures and resulting vitamin D status are unknown. To examine seasonal vitamin D status in photosensitive patients relative to healthy individuals and to assess quantitatively behavioural and demographic contributors. This was a longitudinal prospective cohort study (53·5°N) examining year-round 25-hydroxyvitamin D [25(OH)D] levels, sun-exposure behaviour and oral vitamin D intake in photosensitive patients diagnosed at a photoinvestigation unit (n = 53), compared with concurrently assessed healthy adults (n = 109). Photosensitive patients achieved seasonal 25(OH)D variation, but insufficient (exposure (P = 0·004) and greater sunscreen use (P exposure predicted summer peak and winter trough 25(OH)D levels. A 1 μg per day increment in supplementary vitamin D raised summer and winter 25(OH)D by 5% (95% CI 3-7) and 9% (95% CI 5-12), respectively (both P < 0·001). Photosensitive patients are, through their photoprotective measures, at high risk of year-round low vitamin D status. Guidance on oral measures should target this patient group and their physicians. © 2014 British Association of Dermatologists.

  19. Animal Exposure During Burn Tests

    Science.gov (United States)

    Gaume, J. G.

    1978-01-01

    An animal exposure test system (AETS) was designed and fabricated for the purpose of collecting physiological and environmental (temperature) data from animal subjects exposed to combustion gases in large scale fire tests. The AETS consisted of an open wire mesh, two-compartment cage, one containing an exercise wheel for small rodents, and the other containing one rat instrumented externally for electrocardiogram (ECG) and respiration. Cage temperature is measured by a thermistor located in the upper portion of the rat compartment. Animal activity is monitored by the ECG and the records indicate an increase in EMG (electromyograph) noise super-imposed by the increased activity of the torso musculature. Examples of the recordings are presented and discussed as to their significance regarding toxicity of fire gases and specific events occurring during the test. The AETS was shown to be a useful tool in screening materials for the relative toxicity of their outgassing products during pyrolysis and combustion.

  20. Weekday sunlight exposure, but not vitamin D intake, influences the association between vitamin D receptor genotype and circulating concentration 25-hydroxyvitamin D in a pan-European population: the Food4Me study.

    Science.gov (United States)

    Livingstone, Katherine M; Celis-Morales, Carlos; Hoeller, Ulrich; Lambrinou, Christina P; Moschonis, George; Macready, Anna L; Fallaize, Rosalind; Baur, Manuela; Roos, Franz F; Bendik, Igor; Grimaldi, Keith; Navas-Carretero, Santiago; San-Cristobal, Rodrigo; Weber, Peter; Drevon, Christian A; Manios, Yannis; Traczyk, Iwona; Gibney, Eileen R; Lovegrove, Julie A; Saris, Wim H; Daniel, Hannelore; Gibney, Mike; Martinez, J Alfredo; Brennan, Lorraine; Hill, Tom R; Mathers, John C

    2017-02-01

    Little is known about diet- and environment-gene interactions on 25-hydroxyvitamin D (25(OH)D concentration. This cross-sectional study aimed to investigate (i) predictors of 25(OH)D concentration and relationships with vitamin D genotypes and (ii) whether dietary vitamin D intake and sunlight exposure modified these relationships. Participants from the Food4Me study (n = 1312; age 18-79) were genotyped for vitamin D receptor (VDR) and vitamin D binding protein at baseline and a genetic risk score was calculated. Dried blood spot samples were assayed for 25(OH)D concentration and dietary and lifestyle information collected. Circulating 25(OH)D concentration was lower with increasing genetic risk score, lower in females than males, higher in supplement users than non-users and higher in summer than winter. Carriage of the minor VDR allele was associated with lower 25(OH)D concentration in participants with the least sunlight exposure. Vitamin D genotype did not influence the relationship between vitamin D intake and 25(OH)D concentration. Age, sex, dietary vitamin D intake, country, sunlight exposure, season, and vitamin D genetic risk score were associated with circulating 25(OH)D concentration in a pan-European population. The relationship between VDR genotype and 25(OH)D concentration may be influenced by weekday sunlight exposure but not dietary vitamin D intake. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Decreased photochemical efficiency of photosystem II following sunlight exposure of shade-grown leaves of avocado: because of, or in spite of, two kinetically distinct xanthophyll cycles?

    Science.gov (United States)

    Jia, Husen; Förster, Britta; Chow, Wah Soon; Pogson, Barry James; Osmond, C Barry

    2013-02-01

    This study resolved correlations between changes in xanthophyll pigments and photosynthetic properties in attached and detached shade-grown avocado (Persea americana) leaves upon sun exposure. Lutein epoxide (Lx) was deepoxidized to lutein (L), increasing the total pool by ΔL over 5 h, whereas violaxanthin (V) conversion to antheraxanthin (A) and zeaxanthin (Z) ceased after 1 h. During subsequent dark or shade recovery, de novo synthesis of L and Z continued, followed by epoxidation of A and Z but not of L. Light-saturated nonphotochemical quenching (NPQ) was strongly and linearly correlated with decreasing [Lx] and increasing [L] but showed a biphasic correlation with declining [V] and increasing [A+Z] separated when V deepoxidation ceased. When considering [ΔL+Z], the monophasic linear correlation was restored. Photochemical efficiency of photosystem II (PSII) and photosystem (PSI; deduced from the delivery of electrons to PSI in saturating single-turnover flashes) showed a strong correlation in their continuous decline in sunlight and an increase in NPQ capacity. This decrease was also reflected in the initial reduction of the slope of photosynthetic electron transport versus photon flux density. Generally longer, stronger sun exposures enhanced declines in both slope and maximum photosynthetic electron transport rates as well as photochemical efficiency of PSII and PSII/PSI more severely and prevented full recovery. Interestingly, increased NPQ capacity was accompanied by slower relaxation. This was more prominent in detached leaves with closed stomata, indicating that photorespiratory recycling of CO(2) provided little photoprotection to avocado shade leaves. Sun exposure of these shade leaves initiates a continuum of photoprotection, beyond full engagement of the Lx and V cycle in the antenna, but ultimately photoinactivated PSII reaction centers.

  2. Kidney function and influence of sunlight exposure in patients with impaired 24-hydroxylation of vitamin D due to CYP24A1 mutations.

    Science.gov (United States)

    Figueres, Marie-Lucile; Linglart, Agnès; Bienaime, Frank; Allain-Launay, Emma; Roussey-Kessler, Gwenaelle; Ryckewaert, Amélie; Kottler, Marie-Laure; Hourmant, Maryvonne

    2015-01-01

    Loss-of-function mutations of CYP24A1, the enzyme that converts the major circulating and active forms of vitamin D to inactive metabolites, recently have been implicated in idiopathic infantile hypercalcemia. Patients with biallelic mutations in CYP24A1 present with severe hypercalcemia and nephrocalcinosis in infancy or hypercalciuria, kidney stones, and nephrocalcinosis in adulthood. We describe a cohort of 7 patients (2 adults, 5 children) presenting with severe hypercalcemia who had homozygous or compound heterozygous mutations in CYP24A1. Acute episodes of hypercalcemia in infancy were the first symptom in 6 of 7 patients; in all patients, symptoms included nephrocalcinosis, hypercalciuria, low parathyroid hormone (PTH) levels, and higher than expected 1,25-dihydroxyvitamin D levels. Longitudinal data suggested that in most patients, periods of increased sunlight exposure tended to correlate with decreases in PTH levels and increases in calcemia and calciuria. Follow-up of the 2 adult patients showed reduced glomerular filtration rate and extrarenal manifestations, including calcic corneal deposits and osteoporosis. Cases of severe PTH-independent hypercalcemia associated with hypercalciuria in infants should prompt genetic analysis of CYP24A1. These patients should be monitored carefully throughout life because they may be at increased risk for developing chronic kidney disease. Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  3. Stability of Bacillus thuringiensis and NPV Microencapsulated Formulation under Sunlight

    Directory of Open Access Journals (Sweden)

    Samaneh Sadat Naghavi

    2016-06-01

    Full Text Available Microencapsulation technology is used for the formulation of bio pesticides and is effective against the ultra-violet radiation of sunlight. The present research studied the stability of Bt and NPV formulations microencapsulated with gelatin and sodium alginate, individually or in combination. The formulations were evaluated in outdoor space and under sunlight on potted growing cabbage. The stability of each active ingredient tested in each formulation was studied at 0, 3, 7 and 10 days after spraying on cabbage infested with diamondback moth Plutella xylostella second instars larvae. Results showed that non-formulated and microencapsulated formulations not exposed to sunlight (time zero had similar mortality. However, after being exposed to sunlight for three days, the non-formulated Bt and NPV resulted in a significantly lower mortality (less than 40%; compared with the microencapsulated bio pesticides (more than 70% mortality. Fifty percent (50% mortality was reached in microencapsulated formulations after seven and ten days of exposure to sunlight, whereas there was no mortality in larvae exposed to unformulated treated plants after ten days. ANOVA analysis showed the highest larval mortality was achieved by the Bt+NPV gelatin microencapsulated formulation followed by gelatin coated Bt, sodium alginate coated NPV, sodium alginate coated Bt+NPV, gelatin coated NPV and sodium alginate coated Bt. The formulations showed no significant LT50 differences between microencapsulated versus unformulated Bt and NPV.

  4. Post-veraison sunlight exposure induces MYB-mediated transcriptional regulation of anthocyanin and flavonol synthesis in berry skins of Vitis vinifera

    Science.gov (United States)

    Matus, José Tomás; Loyola, Rodrigo; Vega, Andrea; Peña-Neira, Alvaro; Bordeu, Edmundo; Arce-Johnson, Patricio; Alcalde, José Antonio

    2009-01-01

    Anthocyanins, flavan-3-ols, and flavonols are the three major classes of flavonoid compounds found in grape berry tissues. Several viticultural practices increase flavonoid content in the fruit, but the underlying genetic mechanisms responsible for these changes have not been completely deciphered. The impact of post-veraison sunlight exposure on anthocyanin and flavonol accumulation in grape berry skin and its relation to the expression of different transcriptional regulators known to be involved in flavonoid synthesis was studied. Treatments consisting of removing or moving aside the basal leaves which shade berry clusters were applied. Shading did not affect sugar accumulation or gene expression of HEXOSE TRANSPORTER 1, although in the leaf removal treatment, these events were retarded during the first weeks of ripening. Flavonols were the most drastically reduced flavonoids following shading and leaf removal treatments, related to the reduced expression of FLAVONOL SYNTHASE 4 and its putative transcriptional regulator MYB12. Anthocyanin accumulation and the expression of CHS2, LDOX, OMT, UFGT, MYBA1, and MYB5a genes were also affected. Other regulatory genes were less affected or not affected at all by these treatments. Non-transcriptional control mechanisms for flavonoid synthesis are also suggested, especially during the initial stages of ripening. Although berries from the leaf removal treatment received more light than shaded fruits, malvidin-3-glucoside and total flavonol content was reduced compared with the treatment without leaf removal. This work reveals that flavonol-related gene expression responds rapidly to field changes in light levels, as shown by the treatment in which shaded fruits were exposed to light in the late stages of ripening. Taken together, this study establishes MYB-specific responsiveness for the effect of sun exposure and sugar transport on flavonoid synthesis. PMID:19129169

  5. Ultraviolet Sunlight Exposure During Adolescence and Adulthood and Breast Cancer Risk: A Population-based Case-Control Study Among Ontario Women

    National Research Council Canada - National Science Library

    Anderson, Laura N; Cotterchio, Michelle; Kirsh, Victoria A; Knight, Julia A

    2011-01-01

    .... The associations among ultraviolet radiation from sunlight, factors related to cutaneous vitamin D production, and breast cancer risk were evaluated in a population-based case-control study conducted...

  6. Hydration and transparency of the rabbit cornea irradiated with UVB-doses of 0.25 J/cm(2) and 0.5 J/cm(2) compared with equivalent UVB radiation exposure reaching the human cornea from sunlight.

    Science.gov (United States)

    Cejka, Cestmír; Ardan, Taras; Sirc, Jakub; Michálek, Jiří; Beneš, Jiří; Brůnová, Blanka; Rosina, Jozef

    2011-07-01

    Exposure of the cornea to UV radiation from sunlight evokes intraocular inflammation, photokeratitis. Photokeratitis is caused by UVB radiation. It is accompanied by changes of corneal hydration and light absorption. The aim of this study was to examine the effect of two UVB doses on corneal optics in rabbits and to compare these UVB doses with the equivalent exposure of UVB radiation reaching the human cornea from sunlight. Rabbit corneas were irradiated with a daily UVB dose of 0.25 J/cm(2) or 0.5 J/cm(2) for 4 days. One day after finishing the irradiations the rabbits were sacrificed and corneal light absorption measured using our spectrophotometrical method. Corneal hydration was examined using an ultrasonic Pachymeter every experimental day before the irradiation procedure and the last day before sacrificing the animals. Changes in corneal optics appeared after the repeated exposure of the cornea to a UVB dose of 0.25 J/ cm(2) and massively increased after the repeated exposure of the cornea to a UVB dose of 0.5 J/cm(2). The first significant changes in corneal hydration appeared after a single exposure of the cornea to a UVB dose of 0.25 J/cm(2). Changes in corneal hydration appeared after the exposure of the rabbit cornea to a single UVB dose equivalent to 2.6 hours of solar UVB radiation reaching the human cornea, as measured by UVB sensors embedded in the eyes of mannequin heads facing the sun on a beach at noon in July. Repeated exposure of the rabbit cornea to the same UVB dose evoked profound changes in corneal optics. Although comparison of experimental and outdoor conditions are only approximate, the results in rabbits point to the danger for the human eye from UVB radiation when short stays in sunlight are repeated for several consecutive days without UV protection.

  7. Testing a luminescence surface-exposure dating technique

    Science.gov (United States)

    Gliganic, Luke A.; Meyer, Michael; Gehring, Sebastian

    2016-04-01

    Recent work has shown that the relationship between the luminescence signal (optically stimulated [OSL] and infra-red stimulated [IRSL]) and depth into a rock surface can be used to estimate the length of time since that rock surface has been exposed to sunlight (Sohbati et al., 2012), thus serving as a means for surface-exposure dating. Despite the potential of this new dating tool, few published studies have tested or used this technique. Here, we present the results of two tests of the method. First, we perform laboratory bleaching experiments using two unexposed bedrock samples of different lithologies (granite and quartzite). Sub-samples were bleached for various durations (0 to 100,000 s) in a solar simulator, and IRSL/OSL-depth profiles were measured and fitted using the model of Sohbati et al. (2012). Results of fitting for each sub-sample were then compared. Second, we used a granite boulder from a known age moraine (1850 CE) to test the reproducibility of bleaching depth curves. Multiple cores were collected from the same ~5 cm2 surface area of the boulder, and IRSL-depth profiles were measured and modelled. While our systematic tests confirm the general physical basis of luminescence surface-exposure dating method, we found unexpected scatter in both adjacent bleaching depth curves and the fitting parameters of isochronous rock surfaces for some of our samples. Potential sources of error, including small-scale lithological variabilities and implications for accuracy and precision of the method are discussed. Sohbati, R., Murray, A.S., Chapot, M.S., Jain, M., Pederson, J. (2012) Optically stimulated luminescence (OSL) as a chronometer for surface exposure dating. Journal of Geophysical Research 117 (B9), B09202. doi.org/10.1029/2012JB009383.

  8. Sunlight and Vitamin D

    Science.gov (United States)

    Wacker, Matthias; Holick, Michael F.

    2013-01-01

    Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3. Previtamin D3 and vitamin D3 also absorb UV B radiation and are converted into a variety of photoproducts some of which have unique biologic properties. Sun induced vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D which is a major circulating form and 1,25-dihydroxyvitamin D which is the biologically active form respectively. 1,25-dihydroxyvitamin D plays an important role in regulating calcium and phosphate metabolism for maintenance of metabolic functions and for skeletal health. Most cells and organs in the body have a vitamin D receptor and many cells and organs are able to produce 1,25-dihydroxyvitamin D. As a result 1,25-dihydroxyvitamin D influences a large number of biologic pathways which may help explain association studies relating vitamin D deficiency and living at higher latitudes with increased risk for many chronic diseases including autoimmune diseases, some cancers, cardiovascular disease, infectious disease, schizophrenia and type 2 diabetes. A three-part strategy of increasing food fortification programs with vitamin D, sensible sun exposure recommendations and encouraging ingestion of a vitamin D supplement when needed should be implemented to prevent global vitamin D deficiency and its negative health consequences. PMID:24494042

  9. Polymorphisms in DNA repair genes XRCC1 and XRCC3, occupational exposure to arsenic and sunlight, and the risk of non-melanoma skin cancer in a European case-control study.

    Science.gov (United States)

    Surdu, Simona; Fitzgerald, Edward F; Bloom, Michael S; Boscoe, Francis P; Carpenter, David O; Haase, Richard F; Gurzau, Eugen; Rudnai, Peter; Koppova, Kvetoslava; Vahter, Marie; Leonardi, Giovanni; Goessler, Walter; Kumar, Rajiv; Fletcher, Tony

    2014-10-01

    X-ray repair cross-complementing group 1 (XRCC1) and group 3 (XRCC3) polymorphisms are relatively frequent in Caucasian populations and may have implications in skin cancer modulation. A few studies have evaluated their association with non-melanoma skin cancer (NMSC), but the results are inconsistent. In the current study, we aim to assess the impact of XRCC1 R399Q and XRCC3 T241M polymorphisms on the risk of NMSC associated with sunlight and arsenic exposure. Study participants consist of 618 new cases of NMSC and 527 hospital-based controls frequency matched on age, sex, and county of residence from Hungary, Romania, and Slovakia. Adjusted effects are estimated using multivariable logistic regression. The results indicate an increased risk of squamous cell carcinoma (SCC) for the homozygous variant genotype of XRCC1 R399Q (OR 2.53, 95% CI 1.14-5.65) and a protective effect against basal cell carcinoma (BCC) for the homozygous variant genotype of XRCC3 T241M (OR 0.61, 95% CI 0.41-0.92), compared with the respective homozygous common genotypes. Significant interactions are detected between XRCC3 T241M and sunlight exposure at work, and between XRCC3 T241M and exposure to arsenic in drinking water (p-value for interaction exposure to sunlight or arsenic. Given the high prevalence of genetic polymorphisms modifying the association between exposure to environmental carcinogens and NMSC, these results are of substantial relevance to public health. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Persistence of benthiocarb in soil: influence of ultraviolet and sunlight

    Directory of Open Access Journals (Sweden)

    Md. Wasim Aktar

    2008-12-01

    Full Text Available Persistence of benthiocarb in soil as affected by UV and sunlight exposure was studied. Treated soil was placed in petri plate, brought to field capacity moisture and then exposed to UV and sunlight. Residues of benthiocarb in soil dissipated with half lives of 2.10, 11.85 and 43.63 days under UV, sunlight and dark condition, respectively. Soil samples kept under dark showed the slowest dissipation. Further, benthiocarb residues dissipated quickly under UV light as compared to sunlight. Exposure of thin film of benthiocarb confirmed that it is photo labile and dissipated very fast with half life of 1.16 and 1.77 days following exposure to UV and sunlight, respectively. The study revealed that UV component of sunlight is an important factor for benthiocarb dissipation.

  11. ADEQUATE UV EXPOSURES FOR HEALTHY LIFE: IN SITU MONITORING AND MODEL CALCULATION OF THE VITAMIN-D-SYNTHETIC CAPACITY OF SUNLIGHT

    Directory of Open Access Journals (Sweden)

    Irina Terenetskaya

    2012-06-01

    Full Text Available Vitamin D which is formed upon UV solar radiation in human skin is essential in many physiological functions. To estimate beneficial vitamin-D-synthetic capacity of sunlight a bio-equivalent UV dosimeter that is based on the same molecular photochemistry from which vitamin D is photosynthesized in human skin has been developed. The examples of an in situ monitoring of the vitamin-D-synthetic capacity of sunlight using an in vitro model of vitamin D synthesis are presented, and various operational principles of the UV biodosimeter are discussed. In addition, reliable algorithm is presented for direct calculation of previtamin D3 accumulation using the photoreaction mathematical model with solar UV spectra as input data. Critical dependence of previtamin D3 accumulation on cloudiness and aerosols is demonstrated.

  12. Photocatalytic activity of V doped ZnO nanoparticles thin films for the removal of 2- chlorophenol from the aquatic environment under natural sunlight exposure.

    Science.gov (United States)

    Salah, Numan; Hameed, A; Aslam, M; Babkair, Saeed S; Bahabri, F S

    2016-07-15

    Vanadium doped ZnO powders were used as precursors to deposit thin films of V(5+) incorporated ZnO nanoparticles on glass substrates by the pulsed laser deposition technique. The observed variations in Raman signals, visible region shift in the diffuse reflectance spectra along with a small shift in the (101) reflections of the X-ray diffraction (XRD) confirmed the insertion of V(5+) ions in ZnO lattice. No other additional reflection in the XRD results other than ZnO further endorsed the occupation of lattice positions by V entities rather than independent oxide formation. The asymmetric XPS peaks of Zn2p and V2p core levels confirmed the existence of both in the vicinity. The existence of minimal proportion of V(3+) along with V(5+) states varied the alteration of the oxidation states V in the synthetic route. The SEM images at various resolutions displayed the uniform distribution identical nanoparticles without the presence of additional phases in the deposited films. The SEM cross-section measurements revealed the uniform thickness of ∼90 nm of each film, whereas the surface studies of the films were performed by AFM. The as-synthesized films were tested for photocatalytic activity in sunlight illumination for the removal of 2-chlorophenol. The unique feature of the study was the estimation of the photocatalytic activity 20 ppm of 2-chlorophenol by exposing the low exposed area. The degradation of the substrate was measured by liquid phase UV-vis spectroscopy, whereas total organic carbon measurement revealed the mineralization of the substrate. The released Cl(-) ions were also measured by ion chromatography. The estimated flatband potentials and pHzpc values of the V doped materials, by Mott-Schottky analysis and zeta potential measurements respectively, were correlated with the photocatalytic activity. The kinetics of the photocatalytic degradation/mineralization process was estimated and results were correlated with the plausible mechanism. Copyright

  13. South African university student knowledge of eye protection against sunlight

    OpenAIRE

    O. A. Oduntan; A. Carelson; P. Clarke-Farr; R. Hansraj

    2009-01-01

    Exposure to sunlight has been associated with several ocular conditions such as cataract, age-related macular degeneration, and conjunctival neoplasm. Knowledge of protective modalities and good behavioural practice involving eye protection is essential to prevent adverse effects of sunlight. The purpose of this study was to establish knowledge amongst randomly selected university students in South Africa, of prevention modalities against the adverse effects of sunlight. A questionnaire relat...

  14. 40 CFR 59.653 - How do I test portable fuel containers?

    Science.gov (United States)

    2010-07-01

    ....652(c). (2) UV exposure. Perform a sunlight-exposure test by exposing the container to an ultraviolet.... Alternatively, the container may be exposed to direct natural sunlight for an equivalent period of time, as long... (i.e., the pressure cycling, UV exposure, and slosh testing) specified in this section. For other...

  15. Biosphere 2 test module: A ground-based sunlight-driven prototype of a closed ecological life support system

    Science.gov (United States)

    Nelson, Mark; Leigh, Linda; Alling, Abigail; MacCallum, Taber; Allen, John; Alvarez-Romo, Norberto

    Constructed in 1986, the Biosphere 2 Test Module has been used since the end of that year for closed ecological systems experiments. It is the largest closed ecological facility ever built, with a sealed variable volume of some 480 cubic meters. It is built with a skin of steel spaceframes with double-laminated glass panels admitting about 65 percent Photosynthetically Active Radiation (PAR). The floor is of welded steel and there is an underground atmospheric connection via an air duct to a variable volume chamber (``lung'') permitting expansion and contraction of the Test Module's air volume caused by changes in temperature and barometric pressure, which causes a slight positive pressure from inside the closed system to the outside thereby insuring that the very small leakage rate is outward. Several series of closed ecological system investigations have been carried out in this facility. One series of experiments investigated the dynamics of higher plants and associated soils with the atmosphere under varying light and temperature conditions. Another series of experiments included one human in the closed system for three, five and twenty-one days. During these experiments the Test Module had subsystems which completely recycled its water and atmosphere; all the human dietary needs were produced within the facility, and all wastes were recycled using a marsh plant/microbe system. Other experiments have examined the capability of individual component systems used, such as the soil bed reactors, to eliminate experimentally introduced trace gases. Analytic systems developed for these experiments include continuous monitors of eleven atmospheric gases in addition to the complete gas chromatography mass spectrometry (GCMS) examinations of potable, waste system and irrigation water quality.

  16. Direct and Indirect Phototransformation of Graphene Oxide in Sunlight

    Science.gov (United States)

    Direct and indirect (with added H202 that serves as OH precursor) photoreactions of grapheme oxide (GO) were examined under sunlight exposure. The results indicate that GO photoreacts under both conditions, leading to significant alterations in GO's physicochemical properties. In...

  17. Hair cortisol and cortisone are decreased by natural sunlight.

    Science.gov (United States)

    Wester, Vincent L; van der Wulp, Nils R P; Koper, Jan W; de Rijke, Yolanda B; van Rossum, Elisabeth F C

    2016-10-01

    Hair glucocorticoids (cortisol and cortisone) are increasingly used as measures of long-term integrated exposure to glucocorticoid hormones. Glucocorticoids gradually disappear from the hair shaft, which may result from exposure to ultraviolet (UV) radiation in natural sunlight. We aimed to study the influence of sun exposure on hair glucocorticoids. Scalp hair samples were obtained from nine volunteers (median age 33 [range 21-81], 7 females), and part of each hair sample was exposed to three experimental conditions: repeated exposure to natural sunlight for 40h (natural UV), exposure to a high amount of artificial UV radiation, and storage in the dark (control). Hair cortisol (HairF) and cortisone (HairE) were quantified by liquid chromatography-tandem mass spectrometry. When compared to control, HairF was decreased in 9 out of 9 hair samples after natural sunlight exposure (median decrease -3.1pg/mg or -54%, PUV radiation (-4.7pg/mg or -75%, P=0.003). HairE decreased in 8 out of 9 samples, both after natural sunlight (-7.6pg/mg or -32%, P=0.012) and artificial UV (-10.7pg/mg or -52%, P=0.026). Exposure to natural sunlight decreases the glucocorticoid content of scalp hair, apparently through UV radiation, and is therefore an important confounder that should be considered in studies involving the measurement of hair glucocorticoids. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. "Sunlight is said to be the best of disinfectants"*: the efficacy of sun exposure for reducing fungal contamination in used clothes.

    Science.gov (United States)

    Amichai, Boaz; Grunwald, Marcelo H; Davidovici, Batya; Shemer, Avner

    2014-07-01

    Tinea pedis is a common chronic skin disease; the role of contaminated clothes as a possible source of infection or re-infection has not been fully understood. The ability of ultraviolet light to inactivate microorganisms has long been known and UV is used in many applications. To evaluate the effectivity of sun exposure in reducing fungal contamination in used clothes. Fifty-two contaminated socks proven by fungal culture from patients with tinea pedis were studied. The samples were divided into two groups: group A underwent sun exposure for 3 consecutive days and group B remained indoors. At the end of each day fungal cultures of the samples were performed. Overall, there was an increase in the percentage of negative cultures with time. The change was significantly higher in socks that were left in the sun (chi-square for linear trend = 37.449, P exposure of contaminated clothes was effective in lowering the contamination rate. This finding enhances the current trends of energy saving and environmental protection, which recommend low temperature laundry.

  19. Reversible degradation of inverted organic solar cells by concentrated sunlight

    OpenAIRE

    Tromholt, Thomas; Manor, Assaf; Katz, Eugene A.; Frederik C. Krebs

    2011-01-01

    Concentrated sunlight was used to study the performance response of inverted P3HT:PCBM organic solar cells after exposure to high intensity sunlight. Correlations of efficiency as a function of solar intensity were established in the range of 0.5–15 suns at three different stages: for a pristine cell, after 30 min exposure at 5 suns and after 30 min of rest in the dark. High intensity exposure introduced a major performance decrease for all solar intensities, followed by a partial recovery of...

  20. Decreased Photochemical Efficiency of Photosystem II following Sunlight Exposure of Shade-Grown Leaves of Avocado: Because of, or in Spite of, Two Kinetically Distinct Xanthophyll Cycles?1[W

    Science.gov (United States)

    Jia, Husen; Förster, Britta; Chow, Wah Soon; Pogson, Barry James; Osmond, C. Barry

    2013-01-01

    This study resolved correlations between changes in xanthophyll pigments and photosynthetic properties in attached and detached shade-grown avocado (Persea americana) leaves upon sun exposure. Lutein epoxide (Lx) was deepoxidized to lutein (L), increasing the total pool by ΔL over 5 h, whereas violaxanthin (V) conversion to antheraxanthin (A) and zeaxanthin (Z) ceased after 1 h. During subsequent dark or shade recovery, de novo synthesis of L and Z continued, followed by epoxidation of A and Z but not of L. Light-saturated nonphotochemical quenching (NPQ) was strongly and linearly correlated with decreasing [Lx] and increasing [∆L] but showed a biphasic correlation with declining [V] and increasing [A+Z] separated when V deepoxidation ceased. When considering [ΔL+∆Z], the monophasic linear correlation was restored. Photochemical efficiency of photosystem II (PSII) and photosystem (PSI; deduced from the delivery of electrons to PSI in saturating single-turnover flashes) showed a strong correlation in their continuous decline in sunlight and an increase in NPQ capacity. This decrease was also reflected in the initial reduction of the slope of photosynthetic electron transport versus photon flux density. Generally longer, stronger sun exposures enhanced declines in both slope and maximum photosynthetic electron transport rates as well as photochemical efficiency of PSII and PSII/PSI more severely and prevented full recovery. Interestingly, increased NPQ capacity was accompanied by slower relaxation. This was more prominent in detached leaves with closed stomata, indicating that photorespiratory recycling of CO2 provided little photoprotection to avocado shade leaves. Sun exposure of these shade leaves initiates a continuum of photoprotection, beyond full engagement of the Lx and V cycle in the antenna, but ultimately photoinactivated PSII reaction centers. PMID:23213134

  1. Sunlight-induced DNA damage in human mononuclear cells

    DEFF Research Database (Denmark)

    Møller, Peter; Wallin, Hakan; Holst, Erik

    2002-01-01

    of sunlight was comparable to the interindividual variation, indicating that sunlight exposure and the individual's background were the two most important determinants for the basal level of DNA damage. Influence of other lifestyle factors such as exercise, intake of foods, infections, and age could......In this study of 301 blood samples from 21 subjects, we found markedly higher levels of DNA damage (nonpyrimidine dimer types) in the summer than in the winter detected by single-cell gel electrophoresis. The level of DNA damage was influenced by the average daily influx of sunlight ... to blood sampling. The 3 and 6 day periods before sampling influenced DNA damage the most. The importance of sunlight was further emphasized by a positive association of the DNA damage level to the amount of time the subjects had spent in the sun over a 3 day period prior to the sampling. The effect...

  2. Reversible degradation of inverted organic solar cells by concentrated sunlight

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Manor, Assaf; Katz, Eugene A

    2011-01-01

    Concentrated sunlight was used to study the performance response of inverted P3HT:PCBM organic solar cells after exposure to high intensity sunlight. Correlations of efficiency as a function of solar intensity were established in the range of 0.5–15 suns at three different stages: for a pristine....... The transient state is believed to be a result of the breakdown of the diode behaviour of the ZnO electron transport layer by O2 desorption, increasing the hole conductivity. These results imply that accelerated degradation of organic solar cells by concentrated sunlight is not a straightforward process...... cell, after 30 min exposure at 5 suns and after 30 min of rest in the dark. High intensity exposure introduced a major performance decrease for all solar intensities, followed by a partial recovery of the lost performance over time: at 1 sun only 6% of the initial performance was conserved after...

  3. Effect of Natural Sunlight on Bacterial Activity and Differential Sensitivity of Natural Bacterioplankton Groups in Northwestern Mediterranean Coastal Waters

    Science.gov (United States)

    Alonso-Sáez, Laura; Gasol, Josep M.; Lefort, Thomas; Hofer, Julia; Sommaruga, Ruben

    2006-01-01

    We studied the effects of natural sunlight on heterotrophic marine bacterioplankton in short-term experiments. We used a single-cell level approach involving flow cytometry combined with physiological probes and microautoradiography to determine sunlight effects on the activity and integrity of the cells. After 4 h of sunlight exposure, most bacterial cells maintained membrane integrity and viability as assessed by the simultaneous staining with propidium iodide and SYBR green I. In contrast, a significant inhibition of heterotrophic bacterial activity was detected, measured by 5-cyano-2,3 ditolyl tetrazolium chloride reduction and leucine incorporation. We applied microautoradiography combined with catalyzed reporter deposition-fluorescence in situ hybridization to test the sensitivity of the different bacterial groups naturally occurring in the Northwestern Mediterranean to sunlight. Members of the Gammaproteobacteria and Bacteroidetes groups appeared to be highly resistant to solar radiation, with small changes in activity after exposure. On the contrary, Alphaproteobacteria bacteria were more sensitive to radiation as measured by the cell-specific incorporation of labeled amino acids, leucine, and ATP. Within Alphaproteobacteria, bacteria belonging to the Roseobacter group showed higher resistance than members of the SAR11 cluster. The activity of Roseobacter was stimulated by exposure to photosynthetic available radiation compared to the dark treatment. Our results suggest that UV radiation can significantly affect the in situ single-cell activity of bacterioplankton and that naturally dominating phylogenetic bacterial groups have different sensitivity to natural levels of incident solar radiation. PMID:16957198

  4. A Conditional Exposure Control Method for Multidimensional Adaptive Testing

    Science.gov (United States)

    Finkelman, Matthew; Nering, Michael L.; Roussos, Louis A.

    2009-01-01

    In computerized adaptive testing (CAT), ensuring the security of test items is a crucial practical consideration. A common approach to reducing item theft is to define maximum item exposure rates, i.e., to limit the proportion of examinees to whom a given item can be administered. Numerous methods for controlling exposure rates have been proposed…

  5. Identification of microRNAs and their targets associated with fruit-bagging and subsequent sunlight re-exposure in the ‘Granny Smith’ apple exocarp using high-throughput sequencing

    Directory of Open Access Journals (Sweden)

    Dong eQu

    2016-02-01

    Full Text Available Bagged fruits of green apple cultivar ‘Granny Smith’ have been found to turn cardinal red after debagging during fruit-ripening in the Loess Plateau region of China. To understand such phenomenon at post-transcriptional level, we have investigated the roles of microRNAs (miRNAs in response to debagging. Three small RNA libraries were primarily constructed from peels of ‘Granny Smith’ apples subjected to bagging followed by sunlight re-exposure treatments (0h, 6h, 1d (debagging, and from peels of apples without any bagging treatments (0h, 6h, 1d. 201 known miRNAs belonging to 43 miRNA families and 220 novel miRNAs were identified via high-throughput sequencing. Some miRNAs were found to be differentially expressed after debagging, which indicated that miRNAs affected anthocyanin accumulation through their target genes in mature apple. To further explore the effect of debagging on miRNAs regulating the expression of anthocyanin regulatory genes, four miRNAs and their target genes regulating anthocyanin accumulation, miR156, miR828, miR858 and miR5072, were compared between green cultivar ‘Granny Smith’ and red cultivar ‘Starkrimson’. Results showed that mdm-miR828 and mdm-miR858 regulated anthocyanin contents in both apple cultivars, while mdm-miR156 only affected anthocyanin accumulation in ‘Granny Smith’, and miR5072 affected anthocyanin accumulation in ‘Starkrimson’. Additional analysis of gene ontology for the differentially expressed miRNAs after debagging treatments and their predicted target genes showed that they were involved in photo-protective response after debagging from 0h to 1d; they might play important roles in fruit development and adaptation to high light stress.

  6. Identification of MicroRNAs and Their Targets Associated with Fruit-Bagging and Subsequent Sunlight Re-exposure in the "Granny Smith" Apple Exocarp Using High-Throughput Sequencing.

    Science.gov (United States)

    Qu, Dong; Yan, Fei; Meng, Rui; Jiang, Xiaobing; Yang, Huijuan; Gao, Ziyi; Dong, Yonghui; Yang, Yazhou; Zhao, Zhengyang

    2016-01-01

    Bagged fruits of green apple cultivar "Granny Smith" have been found to turn cardinal red after debagging during fruit-ripening in the Loess Plateau region of China. To understand this phenomenon at post-transcriptional level, we have investigated the roles of microRNAs (miRNAs) in response to debagging. Three small RNA libraries were primarily constructed from peels of "Granny Smith" apples subjected to bagging followed by sunlight re-exposure treatments (0, 6 h, 1 day) (debagging), and from peels of apples without any bagging treatments (0, 6 h, 1 day). 201 known miRNAs belonging to 43 miRNA families and 220 novel miRNAs were identified via high-throughput sequencing. Some miRNAs were found to be differentially expressed after debagging, which indicated that miRNAs affected anthocyanin accumulation through their target genes in mature apple. To further explore the effect of debagging on miRNAs regulating the expression of anthocyanin regulatory genes, four miRNAs and their target genes regulating anthocyanin accumulation, miR156, miR828, miR858, and miR5072, were compared between green cultivar "Granny Smith" and red cultivar "Starkrimson." Results showed that mdm-miR828 and mdm-miR858 regulated anthocyanin contents in both apple cultivars, while mdm-miR156 only affected anthocyanin accumulation in "Granny Smith," and miR5072 affected anthocyanin accumulation in "Starkrimson." Additional analysis of gene ontology for the differentially expressed miRNAs after debagging treatments and their predicted target genes showed that they were involved in photo-protective response after debagging from 0 h to 1 day; they might play important roles in fruit development and adaptation to high light stress.

  7. Identification of MicroRNAs and Their Targets Associated with Fruit-Bagging and Subsequent Sunlight Re-exposure in the “Granny Smith” Apple Exocarp Using High-Throughput Sequencing

    Science.gov (United States)

    Qu, Dong; Yan, Fei; Meng, Rui; Jiang, Xiaobing; Yang, Huijuan; Gao, Ziyi; Dong, Yonghui; Yang, Yazhou; Zhao, Zhengyang

    2016-01-01

    Bagged fruits of green apple cultivar “Granny Smith” have been found to turn cardinal red after debagging during fruit-ripening in the Loess Plateau region of China. To understand this phenomenon at post-transcriptional level, we have investigated the roles of microRNAs (miRNAs) in response to debagging. Three small RNA libraries were primarily constructed from peels of “Granny Smith” apples subjected to bagging followed by sunlight re-exposure treatments (0, 6 h, 1 day) (debagging), and from peels of apples without any bagging treatments (0, 6 h, 1 day). 201 known miRNAs belonging to 43 miRNA families and 220 novel miRNAs were identified via high-throughput sequencing. Some miRNAs were found to be differentially expressed after debagging, which indicated that miRNAs affected anthocyanin accumulation through their target genes in mature apple. To further explore the effect of debagging on miRNAs regulating the expression of anthocyanin regulatory genes, four miRNAs and their target genes regulating anthocyanin accumulation, miR156, miR828, miR858, and miR5072, were compared between green cultivar “Granny Smith” and red cultivar “Starkrimson.” Results showed that mdm-miR828 and mdm-miR858 regulated anthocyanin contents in both apple cultivars, while mdm-miR156 only affected anthocyanin accumulation in “Granny Smith,” and miR5072 affected anthocyanin accumulation in “Starkrimson.” Additional analysis of gene ontology for the differentially expressed miRNAs after debagging treatments and their predicted target genes showed that they were involved in photo-protective response after debagging from 0 h to 1 day; they might play important roles in fruit development and adaptation to high light stress. PMID:26870053

  8. Sunlight decreased genotoxicity of azadirachtin on root tip cells of Allium cepa and Eucrosia bicolor.

    Science.gov (United States)

    Kwankua, W; Sengsai, S; Kuleung, C; Euawong, N

    2010-07-01

    Utilization of neem plant (Azadirachta indica A. Juss) extract for pest control in agriculture has raised concerns over contamination by the residues to the environment. Such residues, particularly azadirachtin (Aza), may cause deleterious effect to non-target organisms. This investigation was conducted to find out if Aza could be inactivated through exposures to sunlight. Activity of Aza was assessed as its ability to cause cytotoxic and genotoxic effects in the forms of nuclei abnormality and chromosome aberration as measured by mitotic index (MI) and mitotic aberration (MA). Varying concentrations of Aza were tested on Allium cepa and Eucrosia bicolor. It was found that the MI of all root tip meristematic cells of A. cepa and E. bicolor treated with 0.00005%, 0.00010%, 0.00015%, and 0.00020% (w/v) Aza-containing neem extract for 24h, were significantly lower than the controls. Complementary to the lower levels of MI, the Aza-treated groups showed higher MA levels in all cases investigated. Furthermore, the decreasing levels of MI and the increasing levels of MA related well with the increasing concentration of Aza. Microscopic examination of root tip meristematic cells revealed that the anomaly found most often were mitotic disturbances and chromosomal bridges. Exposures of 0.00020% (w/v) Aza to sunlight for 3 days and 7 days decreased Aza ability to induce cytotoxicity and genotoxicity, both in terms of MI and MA, to root tip meristematic cells in A. cepa and E. bicolor. Photodegradation of Aza upon exposure to direct sunlight was confirmed by HPLC. The study implicates that Aza would unlikely cause long term deleterious effects to the environment since it would be inactivated by sunlight. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  9. Reversible degradation of inverted organic solar cells by concentrated sunlight.

    Science.gov (United States)

    Tromholt, Thomas; Manor, Assaf; Katz, Eugene A; Krebs, Frederik C

    2011-06-03

    Concentrated sunlight was used to study the performance response of inverted P3HT:PCBM organic solar cells after exposure to high intensity sunlight. Correlations of efficiency as a function of solar intensity were established in the range of 0.5-15 suns at three different stages: for a pristine cell, after 30 min exposure at 5 suns and after 30 min of rest in the dark. High intensity exposure introduced a major performance decrease for all solar intensities, followed by a partial recovery of the lost performance over time: at 1 sun only 6% of the initial performance was conserved after the high intensity exposure, while after rest the performance had recovered to 60% of the initial value. The timescale of the recovery effect was studied by monitoring the cell performance at 1 sun after high intensity exposure. This showed that cell performance was almost completely restored after 180 min. The transient state is believed to be a result of the breakdown of the diode behaviour of the ZnO electron transport layer by O(2) desorption, increasing the hole conductivity. These results imply that accelerated degradation of organic solar cells by concentrated sunlight is not a straightforward process, and care has to be taken to allow for a sound accelerated lifetime assessment based on concentrated sunlight.

  10. Effect of Sunlight Radiation on the Growth and Chemical Constituents of Salvia plebeia R.Br.

    Directory of Open Access Journals (Sweden)

    Hyun-Jae Jang

    2017-08-01

    Full Text Available This study investigated the chemical composition changes of Salvia plebeia R.Br. cultivated under different light sources, including florescent light and sunlight. The plants were exposed to fluorescent light for four months and sunlight and then examined for the next 5–7 months. Plants were harvested monthly during the seven months, and we examined whether the difference in light source affected the phenolic and flavonoid contents and antioxidant activity. A simple and reliable HPLC method using a PAH C18 column was applied for the quantitative analysis of two triterpenoids from the S. plebeia groups. Oleanolic acid (OA and ursolic acid (UA showed good linearity (R2 > 0.9999 within the test ranges (0.005–0.05 mg/mL, and the average percentage recoveries of the OA and UA were 95.1–104.8% and 97.2–107.1%, respectively. The intra- and inter-day relative standard deviations (RSDs were less than 2.0%. After exposure to sunlight, the phenolic contents, including rosmarinic acid, showed a reduced tendency, whereas the flavonoid contents, including homoplantaginin and luteolin 7-glucoside, were increased. The content of the triterpenoids also showed an increased tendency under sunlight irradiation, but the variance was not larger than those of the phenolic and flavonoid contents. Among experimental groups, the group harvested at six months, having been exposed to sunlight for two months, showed the most potent antioxidant activity. Therefore, these results showed that the chemical composition and antioxidant activities of S. plebeia R.Br. was affected from environmental culture conditions, such as light source. Our studies will be useful for the development of functional materials using S. plebeia R.Br.

  11. Effect of Sunlight Radiation on the Growth and Chemical Constituents of Salvia plebeia R.Br.

    Science.gov (United States)

    Jang, Hyun-Jae; Lee, Seung-Jae; Kim, Cha Young; Hwang, Joo Tae; Choi, Jung Ho; Park, Jee Hun; Lee, Seung Woong; Rho, Mun-Chual

    2017-08-01

    This study investigated the chemical composition changes of Salvia plebeia R.Br. cultivated under different light sources, including florescent light and sunlight. The plants were exposed to fluorescent light for four months and sunlight and then examined for the next 5-7 months. Plants were harvested monthly during the seven months, and we examined whether the difference in light source affected the phenolic and flavonoid contents and antioxidant activity. A simple and reliable HPLC method using a PAH C18 column was applied for the quantitative analysis of two triterpenoids from the S. plebeia groups. Oleanolic acid (OA) and ursolic acid (UA) showed good linearity (R² > 0.9999) within the test ranges (0.005-0.05 mg/mL), and the average percentage recoveries of the OA and UA were 95.1-104.8% and 97.2-107.1%, respectively. The intra- and inter-day relative standard deviations (RSDs) were less than 2.0%. After exposure to sunlight, the phenolic contents, including rosmarinic acid, showed a reduced tendency, whereas the flavonoid contents, including homoplantaginin and luteolin 7-glucoside, were increased. The content of the triterpenoids also showed an increased tendency under sunlight irradiation, but the variance was not larger than those of the phenolic and flavonoid contents. Among experimental groups, the group harvested at six months, having been exposed to sunlight for two months, showed the most potent antioxidant activity. Therefore, these results showed that the chemical composition and antioxidant activities of S. plebeia R.Br. was affected from environmental culture conditions, such as light source. Our studies will be useful for the development of functional materials using S. plebeia R.Br.

  12. A 6-month "self-monitoring" lifestyle modification with increased sunlight exposure modestly improves vitamin D status, lipid profile and glycemic status in overweight and obese Saudi adults with varying glycemic levels.

    Science.gov (United States)

    Al-Daghri, Nasser M; Alfawaz, Hanan; Aljohani, Naji J; Al-Saleh, Yousef; Wani, Kaiser; Alnaami, Abdullah M; Alharbi, Mohammad; Kumar, Sudhesh

    2014-05-26

    The over-all age-adjusted prevalence of diabetes mellitus type 2 (DMT2) in Saudi Arabia is unprecedented at 31%. Aggressive measures should be done to curb down increasing incidence. In this prospective 6-month study we aim to determine whether a self-monitoring, life-style modification program that includes increased sunlight exposure confer improvement in vitamin D status and health benefits among adult Saudi overweight and obese patients with varying glycemic status. A total of 150 overweight and obese Saudi adults with varying glycemic status aged 30-60 years were included in this study. They were divided into 3 groups (Non-DMT2, Pre-diabetes and DMT2). Baseline anthropometrics and blood glucose were taken at baseline and after 6 months. Fasting blood sugar, lipid profile, calcium, albumin and phosphate were measured routinely. Serum 25(OH) vitamin D was measured using standard assays. Within the time period they were instructed to reduce total intake of fat, increased fiber intake and increase sun exposure. In all groups there was a significant improvement in vitamin D levels as well as serum triglycerides, LDL- and total cholesterol. However, a significant increase in serum glucose levels was noted in the non-DMT2 group, and a significant decrease in HDL-cholesterol in both non-DMT2 and pre-diabetes group. In the pre-diabetes group, 53.2% were able to normalize their fasting blood levels after 6 months, with 8.5% reaching the DMT2 stage and 38.3% remaining pre-diabetic. In all groups there was a significant increase in the prevalence of hypertension. Improving vitamin D status with modest lifestyle modifications over a short-period translates to improvement in lipid profile except HDL-cholesterol among overweight and obese Saudi adults, but not BMI and blood pressure. Findings of the present study merit further investigation as to whether full vitamin D status correction can delay or prevent onset of DMT2.

  13. Investigating Item Exposure Control Methods in Computerized Adaptive Testing

    Science.gov (United States)

    Ozturk, Nagihan Boztunc; Dogan, Nuri

    2015-01-01

    This study aims to investigate the effects of item exposure control methods on measurement precision and on test security under various item selection methods and item pool characteristics. In this study, the Randomesque (with item group sizes of 5 and 10), Sympson-Hetter, and Fade-Away methods were used as item exposure control methods. Moreover,…

  14. Breath testing and personal exposure--SIFT-MS detection of breath acetonitrile for exposure monitoring.

    Science.gov (United States)

    Storer, Malina; Curry, Kirsty; Squire, Marie; Kingham, Simon; Epton, Michael

    2015-05-26

    Breath testing has potential for the rapid assessment of the source and impact of exposure to air pollutants. During the development of a breath test for acetonitrile using selected ion flow tube mass spectrometry (SIFT-MS) raised acetonitrile concentrations in the breath of volunteers were observed that could not be explained by known sources of exposure. Workplace/laboratory exposure to acetonitrile was proposed since this was common to the volunteers with increased breath concentrations. SIFT-MS measurements of acetonitrile in breath and air were used to confirm that an academic chemistry laboratory was the source of exposure to acetonitrile, and quantify the changes that occurred to exhaled acetonitrile after exposure. High concentrations of acetonitrile were detected in the air of the chemistry laboratory. However, concentrations in the offices were not significantly different across the campus. There was a significant difference in the exhaled acetonitrile concentrations of people who worked in the chemistry laboratories (exposed) and those who did not (non-exposed). SIFT-MS testing of air and breath made it possible to determine that occupational exposure to acetonitrile in the chemistry laboratory was the cause of increased exhaled acetonitrile. Additionally, the sensitivity was adequate to measure the changes to exhaled amounts and found that breath concentrations increased quickly with short exposure and remained increased even after periods of non-exposure. There is potential to add acetonitrile to a suite of VOCs to investigate source and impact of poor air quality.

  15. Sunlight Responsive Thermochromic Window System

    Energy Technology Data Exchange (ETDEWEB)

    Millett, F,A; Byker,H, J

    2006-10-27

    Pleotint has embarked on a novel approach with our Sunlight Responsive Thermochromic, SRT™, windows. We are integrating dynamic sunlight control, high insulation values and low solar heat gain together in a high performance window. The Pleotint SRT window is dynamic because it reversibly changes light transmission based on thermochromics activated directly by the heating effect of sunlight. We can achieve a window package with low solar heat gain coefficient (SHGC), a low U value and high insulation. At the same time our windows provide good daylighting. Our innovative window design offers architects and building designers the opportunity to choose their desired energy performance, excellent sound reduction, external pane can be self-cleaning, or a resistance to wind load, blasts, bullets or hurricanes. SRT windows would provide energy savings that are estimated at up to 30% over traditional window systems. Glass fabricators will be able to use existing equipment to make the SRT window while adding value and flexibility to the basic design. Glazing installers will have the ability to fit the windows with traditional methods without wires, power supplies and controllers. SRT windows can be retrofit into existing buildings,

  16. Sunlight affects aggregation and deposition of graphene oxide in the aquatic environment.

    Science.gov (United States)

    In this study, we investigate the role of simulated sunlight on the physicochemical properties, aggregation, and deposition of graphene oxide (GO) in aquatic environments. Results show that light exposure under varied environmental conditions significantly impacts the physicochem...

  17. Photodegradation of pharmaceuticals in the aquatic environment by sunlight and UV-A, -B and -C irradiation.

    Science.gov (United States)

    Kawabata, Kohei; Sugihara, Kazumi; Sanoh, Seigo; Kitamura, Shigeyuki; Ohta, Shigeru

    2013-01-01

    In order to investigate the effect of sunlight on the persistence and ecotoxicity of pharmaceuticals contaminating the aquatic environment, we exposed nine pharmaceuticals (acetaminophen (AA), amiodarone (AM), dapsone (DP), dexamethasone (DX), indomethacin (IM), naproxen (NP), phenytoin (PH), raloxifene (RL), and sulindac (SL)) in aqueous media to sunlight and to ultraviolet (UV) irradiation at 254, 302 or 365 nm (UV-C, UV-B or UV-A, respectively). Degradation of the pharmaceuticals was monitored by means of high-performance liquid chromatography (HPLC). Sunlight completely degraded AM, DP and DX within 6 hr, and partly degraded the other pharmaceuticals, except AA and PH, which were not degraded. Similar results were obtained with UV-B, while UV-A was less effective (both UV-A and -B are components of sunlight). All the pharmaceuticals were photodegraded by UV-C, which is used for sterilization in sewage treatment plants. Thus, the photodegradation rates of pharmaceuticals are dependent on both chemical structure and the wavelength of UV exposure. Toxicity assay using the luminescent bacteria test (ISO11348) indicated that UV irradiation reduced the toxicity of some pharmaceuticals to aquatic organisms by decreasing their amount (photodegradation) and increased the toxicity of others by generating toxic photoproduct(s). These results indicate the importance of investigating not only parent compounds, but also photoproducts in the risk assessment of pharmaceuticals in aquatic environments.

  18. Sunlight-stimulated phenylalanine ammonia-lyase (PAL activity and anthocyanin accumulation in exocarp of ‘Mahajanaka’ mango

    Directory of Open Access Journals (Sweden)

    Kobkiat Saengnil

    2011-11-01

    Full Text Available The activity of phenylalanine ammonia-lyase (PAL required for anthocyanin synthesis was stimulated by sunlight exposure resulting in the development of red colour in ‘Mahajanaka’ mango exocarp, which occurred only on the sunlight-exposed side of the fruit. The accumulation of anthocyanin was concurrent with the increase in PAL activity in the mature stage of the fruit. The exposed side of the fruit had higher PAL activity, endogenous sugar content, and anthocyanin accumulation than the unexposed side. It is concluded that sunlight increases red colour development of the mango exocarp by inducing PAL activity. Exposure to sunlight also enhances endogenous sugar accumulation in mango fruit.

  19. Simulated Space Vacuum Ultraviolet (VUV) Exposure Testing for Polymer Films

    Science.gov (United States)

    Dever, Joyce A.; Pietromica, Anthony J.; Stueber, Thomas J.; Sechkar, Edward A.; Messer, Russell K.

    2002-01-01

    Vacuum ultraviolet (VUV) radiation of wavelengths between 115 and 200 nm produced by the sun in the space environment can cause degradation to polymer films producing changes in optical, mechanical, and chemical properties. These effects are particularly important for thin polymer films being considered for ultra-lightweight space structures, because, for most polymers, VUV radiation is absorbed in a thin surface layer. NASA Glenn Research Center has developed facilities and methods for long-term ground testing of polymer films to evaluate space environmental VUV radiation effects. VUV exposure can also be used as part of sequential simulated space environmental exposures to determine combined damaging effects. This paper will describe the effects of VUV on polymer films and the necessity for ground testing. Testing practices used at Glenn Research Center for VUV exposure testing will be described including characterization of the VUV radiation source used, calibration procedures traceable to the National Institute of Standards and Technology (NIST), and testing techniques for VUV exposure of polymer surfaces.

  20. Life-threatening motor vehicle crashes in bright sunlight.

    Science.gov (United States)

    Redelmeier, Donald A; Raza, Sheharyar

    2017-01-01

    Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight.This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later.The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9-24, P vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash.

  1. Multistage Computerized Adaptive Testing with Uniform Item Exposure

    Science.gov (United States)

    Edwards, Michael C.; Flora, David B.; Thissen, David

    2012-01-01

    This article describes a computerized adaptive test (CAT) based on the uniform item exposure multi-form structure (uMFS). The uMFS is a specialization of the multi-form structure (MFS) idea described by Armstrong, Jones, Berliner, and Pashley (1998). In an MFS CAT, the examinee first responds to a small fixed block of items. The items comprising…

  2. Weathering patterns of polycyclic aromatic hydrocarbons contained in submerged Deepwater Horizon oil spill residues when re-exposed to sunlight.

    Science.gov (United States)

    John, Gerald F; Han, Yuling; Clement, T Prabhakar

    2016-12-15

    The Deepwater Horizon (DWH) oil spill event released a large amount of sweet crude oil into the Gulf of Mexico (GOM). An unknown portion of this oil that arrived along the Alabama shoreline interacted with nearshore sediments and sank forming submerged oil mats (SOMs). A considerable amount of hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs), were trapped within these buried SOMs. Recent studies completed using the oil spill residues collected along the Alabama shoreline have shown that several PAHs, especially higher molecular weight PAHs (four or more aromatic rings), are slowly weathering compared to the weathering levels experienced by the oil when it was floating over the GOM. In this study we have hypothesized that the weathering rates of PAHs in SOMs have slowed down because the buried oil was isolated from direct exposure to sunlight, thus hindering the photodegradation pathway. We further hypothesized that re-exposing SOMs to sunlight can reactivate various weathering reactions. Also, SOMs contain 75-95% sand (by weight) and the entrapped sand could either block direct sunlight or form large oil agglomerates with very little exposed surface area; these processes could possibly interfere with weathering reactions. To test these hypotheses, we completed controlled experiments to study the weathering patterns of PAHs in a field recovered SOM sample after re-exposing it to sunlight. Our experimental results show that the weathering levels of several higher molecular weight PAHs have slowed down primarily due to the absence of sunlight-induced photodegradation reactions. The data also show that sand particles in SOM material could potentially interfere with photodegradation reactions.

  3. Systems for animal exposure in full-scale fire tests

    Science.gov (United States)

    Hilado, C. J.; Cumming, H. J.; Kourtides, D. A.; Parker, J. A.

    1977-01-01

    Two systems for exposing animals in full-scale fire tests are described. Both systems involve the simultaneous exposure of two animal species, mice and rats, in modular units; determination of mortality, morbidity, and behavioral response; and analysis of the blood for carboxyhemoglobin. The systems described represent two of many possible options for obtaining bioassay data from full-scale fire tests. In situations where the temperatures to which the test animals are exposed can not be controlled, analytical techniques may be more appropriate than bioassay techniques.

  4. Sunlight, ultraviolet radiation, vitamin D and skin cancer: how much sunlight do we need?

    Science.gov (United States)

    Holick, Michael F

    2014-01-01

    Vitamin D is the sunshine vitamin for good reason. During exposure to sunlight, the UV B photons enter the skin and photolyze 7-dehydrocholesterol to previtamin D3 which in turn is isomerized by the body's temperature to vitamin D3. Most humans have depended on sun for their vitamin D requirement. Skin pigment, sunscreen use, aging, time of day, season and latitude dramatically affect previtamin 13 synthesis. Vitamin D deficiency was thought to have been conquered, but it is now recognized that more than 50% of the world's population is at risk for vitamin D deficiency. This deficiency is in part due to the inadequate fortification of foods with vitamin D and the misconception that a healthy diet contains an adequate amount of vitamin D. Vitamin D deficiency causes growth retardation and rickets in children and will precipitate and exacerbate osteopenia, osteoporosis and increase risk of fracture in adults. The vitamin D deficiency has been associated pandemic with other serious consequences including increased risk of common cancers, autoimmune diseases, infectious diseases and cardiovascular disease. There needs to be a renewed appreciation of the beneficial effect of moderate sunlight for providing all humans with their vitamin D requirement for health.

  5. Alternative Testing Methods for Predicting Health Risk from Environmental Exposures

    Directory of Open Access Journals (Sweden)

    Annamaria Colacci

    2014-08-01

    Full Text Available Alternative methods to animal testing are considered as promising tools to support the prediction of toxicological risks from environmental exposure. Among the alternative testing methods, the cell transformation assay (CTA appears to be one of the most appropriate approaches to predict the carcinogenic properties of single chemicals, complex mixtures and environmental pollutants. The BALB/c 3T3 CTA shows a good degree of concordance with the in vivo rodent carcinogenesis tests. Whole-genome transcriptomic profiling is performed to identify genes that are transcriptionally regulated by different kinds of exposures. Its use in cell models representative of target organs may help in understanding the mode of action and predicting the risk for human health. Aiming at associating the environmental exposure to health-adverse outcomes, we used an integrated approach including the 3T3 CTA and transcriptomics on target cells, in order to evaluate the effects of airborne particulate matter (PM on toxicological complex endpoints. Organic extracts obtained from PM2.5 and PM1 samples were evaluated in the 3T3 CTA in order to identify effects possibly associated with different aerodynamic diameters or airborne chemical components. The effects of the PM2.5 extracts on human health were assessed by using whole-genome 44 K oligo-microarray slides. Statistical analysis by GeneSpring GX identified genes whose expression was modulated in response to the cell treatment. Then, modulated genes were associated with pathways, biological processes and diseases through an extensive biological analysis. Data derived from in vitro methods and omics techniques could be valuable for monitoring the exposure to toxicants, understanding the modes of action via exposure-associated gene expression patterns and to highlight the role of genes in key events related to adversity.

  6. Life-threatening motor vehicle crashes in bright sunlight

    Science.gov (United States)

    Redelmeier, Donald A.; Raza, Sheharyar

    2017-01-01

    Abstract Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight. This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later. The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9–24, P < 0.001). The increased risk was accentuated in the early afternoon, disappeared at night, extended to patients with different characteristics, involved crashes with diverse features, not apparent with cloudy weather, and contributed to about 5000 additional patient-days in hospital. The increased risk extended to patients with high crash severity as indicated by ambulance involvement, surgical procedures, length of hospital stay, intensive care unit admission, and patient mortality. The increased risk was not easily attributed to differences in alcohol consumption, driving distances, or anomalies of adverse weather. Bright sunlight is associated with an increased risk of a life-threatening motor vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash. Level of evidence: Epidemiologic Study, level III. PMID:28072708

  7. Successful pacing using a batteryless sunlight-powered pacemaker.

    Science.gov (United States)

    Haeberlin, Andreas; Zurbuchen, Adrian; Schaerer, Jakob; Wagner, Joerg; Walpen, Sébastien; Huber, Christoph; Haeberlin, Heinrich; Fuhrer, Juerg; Vogel, Rolf

    2014-10-01

    Today's cardiac pacemakers are powered by batteries with limited energy capacity. As the battery's lifetime ends, the pacemaker needs to be replaced. This surgical re-intervention is costly and bears the risk of complications. Thus, a pacemaker without primary batteries is desirable. The goal of this study was to test whether transcutaneous solar light could power a pacemaker. We used a three-step approach to investigate the feasibility of sunlight-powered cardiac pacing. First, the harvestable power was estimated. Theoretically, a subcutaneously implanted 1 cm(2) solar module may harvest ∼2500 µW from sunlight (3 mm implantation depth). Secondly, ex vivo measurements were performed with solar cells placed under pig skin flaps exposed to a solar simulator and real sunlight. Ex vivo measurements under real sunlight resulted in a median output power of 4941 µW/cm(2) [interquartile range (IQR) 3767-5598 µW/cm(2), median skin flap thickness 3.0 mm (IQR 2.7-3.3 mm)]. The output power strongly depended on implantation depth (ρSpearman = -0.86, P pacemaker powered by a 3.24 cm(2) solar module was implanted in vivo in a pig to measure output power and to pace. In vivo measurements showed a median output power of >3500 µW/cm(2) (skin flap thickness 2.8-3.84 mm). Successful batteryless VVI pacing using a subcutaneously implanted solar module was performed. Based on our results, we estimate that a few minutes of direct sunlight (irradiating an implanted solar module) allow powering a pacemaker for 24 h using a suitable energy storage. Thus, powering a pacemaker by sunlight is feasible and may be an alternative energy supply for tomorrow's pacemakers. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  8. Sunlight regulates the cutaneous production of vitamin D3 by causing its photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Webb, A.R.; DeCosta, B.R.; Holick, M.F.

    1989-05-01

    Exposure to sunlight initiates the formation of vitamin D3 in skin as the UV B radiation in the solar spectrum causes the photoconversion of 7-dehydrocholesterol to previtamin D3. A heat-induced isomerization then converts previtamin D3 to vitamin D3 over a period of days. A number of irradiation products of vitamin D3 are known to form upon irradiation with high intensity UV radiation, but the effect of subsequent exposures to sunlight on the vitamin D3 formed in skin is not known. To investigate this phenomenon, human skin containing vitamin D3 was exposed to sunlight in Boston. A model system of (/sup 3/H)vitamin D3 in methanol was also used to study the effects of sunlight on vitamin D3 throughout the year. Vitamin D3 proved to be exquisitely sensitive to sunlight, and once formed in the skin, exposure to sunlight resulted in its rapid photodegradation to a variety of photoproducts, including 5,6-transvitamin D3, suprasterol I, and suprasterol II.

  9. Technique to separate lidar signal and sunlight.

    Science.gov (United States)

    Sun, Wenbo; Hu, Yongxiang; MacDonnell, David G; Weimer, Carl; Baize, Rosemary R

    2016-06-13

    Sunlight contamination dominates the backscatter noise in space-based lidar measurements during daytime. The background scattered sunlight is highly variable and dependent upon the surface and atmospheric albedo. The scattered sunlight contribution to noise increases over land and snow surfaces where surface albedos are high and thus overwhelm lidar backscatter from optically thin atmospheric constituents like aerosols and thin clouds. In this work, we developed a novel lidar remote sensing concept that potentially can eliminate sunlight induced noise. The new lidar concept requires: (1) a transmitted laser light that carries orbital angular momentum (OAM); and (2) a photon sieve (PS) diffractive filter that separates scattered sunlight from laser light backscattered from the atmosphere, ocean and solid surfaces. The method is based on numerical modeling of the focusing of Laguerre-Gaussian (LG) laser beam and plane-wave light by a PS. The model results show that after passing through a PS, laser light that carries the OAM is focused on a ring (called "focal ring" here) on the focal plane of the PS filter, very little energy arrives at the center of the focal plane. However, scattered sunlight, as a plane wave without the OAM, focuses at the center of the focal plane and thus can be effectively blocked or ducted out. We also find that the radius of the "focal ring" increases with the increase of azimuthal mode (L) of LG laser light, thus increasing L can more effectively separate the lidar signal away from the sunlight noise.

  10. The relationship between long-term sunlight radiation and cognitive decline in the REGARDS cohort study

    Science.gov (United States)

    Kent, Shia T.; Kabagambe, Edmond K.; Wadley, Virginia G.; Howard, Virginia J.; Crosson, William L.; Al-Hamdan, Mohammad Z.; Judd, Suzanne E.; Peace, Fredrick; McClure, Leslie A.

    2014-04-01

    Sunlight may be related to cognitive function through vitamin D metabolism or circadian rhythm regulation. The analysis presented here sought to test whether ground and satellite measures of solar radiation are associated with cognitive decline. The study used a 15-year residential history merged with satellite and ground monitor data to determine sunlight (solar radiation) and air temperature exposure for a cohort of 19,896 cognitively intact black and white participants aged 45+ from the 48 contiguous United States. Exposures of 15, 10, 5, 2, and 1-year were used to predict cognitive status at the most recent assessment in logistic regression models; 1-year insolation and maximum temperatures were chosen as exposure measures. Solar radiation interacted with temperature, age, and gender in its relationships with incident cognitive impairment. After adjustment for covariates, the odds ratio (OR) of cognitive decline for solar radiation exposure below the median vs above the median in the 3rd tertile of maximum temperatures was 1.88 (95 % CI: 1.24, 2.85), that in the 2nd tertile was 1.33 (95 % CI: 1.09, 1.62), and that in the 1st tertile was 1.22 (95 % CI: 0.92, 1.60). We also found that participants under 60 years old had an OR = 1.63 (95 % CI: 1.20, 2.22), those 60-80 years old had an OR = 1.18 (95 % CI: 1.02, 1.36), and those over 80 years old had an OR = 1.05 (0.80, 1.37). Lastly, we found that males had an OR = 1.43 (95 % CI: 1.22, 1.69), and females had an OR = 1.02 (0.87, 1.20). We found that lower levels of solar radiation were associated with increased odds of incident cognitive impairment.

  11. Effects of concentrated sunlight on organic photovoltaics

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Katz, Eugene A.; Hirsch, Baruch

    2010-01-01

    gradually from 0.2 to 27 suns. Power conversion efficiency exhibited slow increase with C that was followed by saturation around 2% at C = 0.5–2.5 suns and subsequent strong reduction. Possible OPV applications in stationary solar concentrators (C ≤ 2 suns) are discussed. Finally, experiments at C = 55......We report the effects of concentrated sunlight on key photovoltaic parameters and stability of organic photovoltaics (OPV). Sunlight collected and concentrated outdoors was focused into an optical fiber and delivered onto a 1 cm2 bulk-heterojunction cell. Sunlight concentration C was varied...

  12. South African university student knowledge of eye protection against sunlight

    Directory of Open Access Journals (Sweden)

    O. A. Oduntan

    2009-12-01

    Full Text Available Exposure to sunlight has been associated with several ocular conditions such as cataract, age-related macular degeneration, and conjunctival neoplasm. Knowledge of protective modalities and good behavioural practice involving eye protection is essential to prevent adverse effects of sunlight. The purpose of this study was to establish knowledge amongst randomly selected university students in South Africa, of prevention modalities against the adverse effects of sunlight. A questionnaire relating to the knowledge of preventive modalities was completed by randomly selected students from four universities selected by convenience sampling.  Questionnaires completed by one thousand, eighthundred and thirty two (N =1832 subjects were analysed with descriptive statistics using Stata version 10.  The participants’ ages ranged from 17 to 55 years (mean = 21.03 ± 3.4 years.  They included 43.7% males and 56.3% females.  They were 68.3% Blacks, 20.0% Whites, 3.4% Indians and 7.4% Coloureds. Many (82.3% of them knew that excessive exposure to sunlight can adversely affect the eyes. Only 28.5% reported that they often wore sunglasses outdoors. Only 38.5% of the participants knew that not all spectacles or contact lenses could protect eyes from ultraviolet radiation. However, many, 87.7% and 69.5% respectively knew that sunglasses and spectacles could be specifically designed to block UVR from entering the eye. Just over half (52.7% knew that contact lenses can be specifically designed to block the UVR. Many, (68.4% agreed that wearing hats with brims could protect the eyes against harmful radiation from the sun and the majority, 95.8% agreed that there was a need for awareness campaigns about the effects of the sun on the eye and against excessive exposure. Female respondents had more knowledge of preventive modalities than the males.  Knowledge of preventive modalities among the respondents varied significantly with the type of questions and was

  13. Can Natural Sunlight Induce Coherent Exciton Dynamics?

    CERN Document Server

    Olšina, Jan; Wang, Chen; Cao, Jianshu

    2014-01-01

    Excitation of a model photosynthetic molecular aggregate by incoherent sunlight is systematically examined. For a closed system, the excited state coherence induced by the sunlight oscillates with an average amplitude that is inversely proportional to the excitonic gap, and reaches a stationary amplitude that depends on the temperature and coherence time of the radiation field. For an open system, the light-induced dynamical coherence relaxes to a static coherence determined by the non-canonical thermal distribution resulting from the entanglement with the phonon bath. The decay of the excited state population to the common ground state establishes a non-equilibrium steady-state flux driven by the sunlight, and it defines a time window to observe the transition from dynamical to static coherence. For the parameters relevant to photosynthetic systems, the exciton dynamics initiated by the sunlight exhibits a non-negligible amount of dynamical coherence (quantum beats) on the sub-picosecond timescale; however, ...

  14. Application of photoremovable protecting group for controlled release of plant growth regulators by sunlight.

    Science.gov (United States)

    Atta, Sanghamitra; Ikbal, Mohammed; Kumar, Ashutosh; Pradeep Singh, N D

    2012-06-01

    We report a novel technique for controlled release of plant growth regulators (PGRs) by sunlight using photoremovable protecting group (PRPG) as a delivery device. In the present work, carboxyl-containing PGRs of the auxin group [indoleacetic acid (IAA) and naphthoxyacetic acid (NOAA)] were chemically caged using PRPGs of coumarin derivatives. Photophysical studies showed that caged PGRs exhibited good fluorescence properties. Irradiation of caged PGRs by sunlight in both aqueous ethanol and soil media resulted in controlled release of PGRs. The results of the bioactivity experiments indicated that caged PGRs showed better enhancement in the root and shoot length growth of Cicer arietinum compared to PGRs after 10days of sunlight exposure. Our results indicated that use of PRPG as a delivery device for controlled release of PGRs by sunlight in soil holds great interest for field application since it can overcome the rapid loss of PGRs in environmental conditions.

  15. Sunlight technologies for photochemical deactivation of organic pollutants in water

    Energy Technology Data Exchange (ETDEWEB)

    Acher, A.; Fischer, E.; Tornheim, R. [The Volcani Center, Inst. of Soils and Water, Bet Dagan (Israel); Manor, Y. [Sheba Medical Center, Central Virology Lab., Ramat Gan (Israel)

    1997-12-31

    Sensitized-photochemical oxidation methods aimed at use in water treatment technologies for deactivation of biotic (microorganisms) and/or of xenobiotic (pesticides) pollutants in water were developed using global solar radiation or concentrated sunlight (up to 250 suns). The solar global radiation was used either for detoxification of industrial waste water from a pesticide factory to allow their discharge into the urban sewer, or for disinfection of domestric effluents to be used in crop irrigation. The disinfection process was eventually carried out in an experimental pilot-scale plant, capable of disinfection up to 50 m{sup 3}/h of effluent supplied by an activated sludge sewage treatment plant located in Tel-Aviv area. The treated effluents did not show any regrowth of the microorganisms during 7 days. The solar concentrated radiation experiments performed using facilities of the Sun Tower of The Weizman Institute of Science, Rehovot. The concentrated sunlight was provided by different combination of several computer controlled heliostates, up to 8, that track the sun and focus the received sunlight onto the target situated on the roof of the sun-tower. The sunlight intensities measured on the target reached up to 200 kW/m{sup 2}. The experiments were performed either batch- or continuous-wise. The water-samples exposed to disinfection were the above effluent, filtered and supplemented with vaccine strain poliovirus or with different concentrations of an industrial potential pollutant (bromacil), MB 2 mg/L and two concentrations of dissolved oxygen (8.0 or 40.0 mg O{sub 2}/L). An exposure time of 2-3 seconds at 150 kW/m{sup 2} was decreased the microorganisms alive (counts) by five orders of magnitude. A comparison between the two above water treatment technologies is presented. (orig./SR)

  16. A test chamber for experimental hydrogen fluoride exposure in humans.

    Science.gov (United States)

    Søstrand, P; Kongerud, J; Eduard, W; Nilsen, T; Skogland, M; Boe, J

    1997-07-01

    An inhalation chamber was built to perform experimental studies with hydrogen fluoride (HF), other gases, and particulate matter. The present study sought to describe a new gas delivery system and the distribution and concentration of HF gas in the chamber. The aluminum chamber has a volume of 19.2 m3 and a variable ventilation rate of about 1 to 10 air changes per hour. The negative pressure difference between the chamber and outside air can be regulated from 0 to 300 Pa. HF was fed at concentrations of up to 4000 mg/m3 directly into the ventilation duct feeding the chamber through openings with diameters as small as 50 microns, oriented opposite to the airflow. Gas flow was varied from about 0.1 dm3/min at a pressure of 4 atm. The dilution factor of HF concentration from cylinder to chamber was on the order of 10(3) to 10(4). The standard deviation (SD) of the HF concentrations at a fixed measurement point during a 1-hour test was typically 0.05 mg/m3 at a time-weighted average (TWA) concentration of 2.66 mg/m3. The SD of the TWA HF concentrations at six locations in the chamber was typically 0.05 mg/m3 and 0.29 mg/m3 at 0.61 and 3.46 mg/m3, respectively. Human exposure could be predicted from calculations based on ventilation data, gas flow, and observed ratio between calculated and measured concentrations. When the target exposure concentration was 1.5 mg/m3, the measured mean exposure concentration was typically 1.54 mg/m3 (range: 1.4-1.7 mg/m3, SD 0.09 mg/m3, n = 8). The chamber is well-suited for inhalation studies in humans. Chamber atmosphere was controlled and has proved to be stable and homogeneous, even in tests with HF, a highly reactive gas in the class of superacids.

  17. TASK 2.5.5 NATURAL EXPOSURE TESTING IN CALIFORNIA

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL; Cheng, Mengdawn [ORNL; New, Joshua Ryan [ORNL; Ronnen, Levinson [Lawrence Berkeley National Laboratory (LBNL); Akbari, Hashem [Lawrence Berkeley National Laboratory (LBNL); Berhahl, Paul [Lawrence Berkeley National Laboratory (LBNL)

    2010-03-01

    Airborne particulate matter that settles on a roof can either reflect or absorb incoming solar radiation, dependent on the chemical content and size of the particles. These light scattering and absorption processes occur within a few microns of the surface, and can affect the solar reflectance of the roof. Wilkes et al. (2000) tested 24 different roof coatings on a low-slope test stand and observed about a 25% decrease in the solar reflectance of white-coated and aluminum-coated surfaces as the time of exposure increased; however, the decrease leveled off after 2 years. SPRI Inc. and its affiliates studied the effect of climatic exposure on the surface properties of white thermoplastic single-ply membranes and determined that membranes lose from 30 to 50% of their reflectance over 3 years (Miller et al. 2002). The CMRC and its affiliates AISI, NamZAC, MBMA, MCA and NCCA exposed unpainted and painted metal roofing on both steep- and low-slope test roofs and found that after 3 years, the painted polyvinylidene fluoride (PVDF) metal roofs lost less than 5% of their original reflectance (Miller et al. 2004). The results of the three different weathering studies are very interesting in terms of their solar reflectance after 3 years of exposure. The white thermoplastic membrane and white ceramic coating with white topcoat had original reflectance measures that were about 20 percentage points higher than the painted metal; however, after 3-years of field exposure the solar reflectance of the painted metal exceeds that of the thermoplastic membrane and equals that of the coating. The long-term loss of reflectance appears driven by the ability of the particulate matter to cling to the roof and resist being washed off by wind and or rain. Miller et al. (2002) discovered that aerosol deposition introduced biomass of complex microbial consortia onto the test roofs and the combination of contaminants and biomass accelerated the loss of solar reflectance for the thermoplastic

  18. (abstract) Cassini MLI Balnkets High-Temperature Exposure Tests

    Science.gov (United States)

    Lin, Edward I.; Stultz, James W.

    1995-01-01

    The trajectory required for the Cassini spacecraft to reach Saturn will subject the spacecraft to a 0.61 AU temperature environment at perihelion. Temperatures on some sunlit blanket surfaces at 0.61 AU can reach levels that are beyond the service capability of the conventional Mylar/Dacron net MLI. The majority of the blanket surfaces, however, will experience temperatures with an upper bound of 250(deg) C. The maximum allowable temperature for Mylar/Dacron net is determined to be 220(deg)C. Kapton can withstand temperatures in excess of 400(deg) C; however, the high cost of embossed Kapton relative to Mylar/Dacron net requires a baseline design which includes a standard layup and a high-temperature layup. The high-temperature layup is utilized at a limited number of locations, while at least 90% of the blankets are of the standard layup. The verification of both layups' capability to meet all temperature requirements has been accomplished by a comprehensive test program which addressed their high-temperature survivability, effective emittance, and optical and electrical properties. This paper focuses on the high-temperature exposure tests which helped define the hybrid standard layup, and which demonstrated the adequacy of both layups in withstanding their respective thermal environments.

  19. Sunlight-Induced Coloration of Silk

    Science.gov (United States)

    Yao, Ya; Tang, Bin; Chen, Wu; Sun, Lu; Wang, Xungai

    2016-06-01

    Silk fabrics were colored by gold nanoparticles (NPs) that were in situ synthesized through the induction of sunlight. Owing to the localized surface plasmon resonance (LSPR) of gold NPs, the treated silk fabrics presented vivid colors. The photo-induced synthesis of gold NPs was also realized on wet silk through adsorbing gold ions out of solution, which provides a water-saving coloration method for textiles. Besides, the patterning of silk was feasible using this simple sunlight-induced coloration approach. The key factors of coloration including gold ion concentration, pH value, and irradiation time were investigated. Moreover, it was demonstrated that either ultraviolet (UV) light or visible light could induce the generation of gold NPs on silk fabrics. The silk fabrics with gold NPs exhibited high light resistance including great UV-blocking property and excellent fastness to sunlight.

  20. Degadation of semiconducting polymers by concentrated sunlight

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Manceau, Matthieu; Petersen, Martin Helgesen

    2011-01-01

    A lens based sunlight concentration setup was used to accelerate the degradation of semiconducting polymers. Sunlight was collected outdoor and focused into an optical fiber bundle allowing for indoor experimental work. Photo-degradation of several polymers was studied by UV–vis absorbance...... spectroscopy and infra-red spectroscopy. This showed that the degradation rate is significantly increased by increasing illumination intensity. Acceleration factors exceeding 100 compared to standard 1 sun illumination were observed for solar concentration of 200 suns in the case of P3HT. A comparison between...

  1. Sunlight Diffusing Tent for Lunar Worksite

    Science.gov (United States)

    Burleson, Blair; Clark, Todd; Deese, Todd; Gentry, Ernest; Samad, Abdul

    1990-01-01

    The purpose is to provide a solution to problems astronauts encounter with sunlight on the lunar surface. Due to the absence of an atmosphere the Moon is subjected to intense sunlight creating problems with color and contrast. This problem can be overcome by providing a way to reduce intensity and diffuse the light in a working environment. The solution to the problem utilizes an umbrella, tent-like structure covered with a diffusing material. The design takes into account structural materials, stresses, fabrics, and deployment.

  2. Novel exposure units for at-home personalized testing of electromagnetic sensibility

    NARCIS (Netherlands)

    Huss, Anke; Murbach, Manuel; van Moorselaar, Imke; Kuster, Niels; van Strien, Rob; Kromhout, Hans; Vermeulen, Roel; Slottje, Pauline

    2016-01-01

    Previous experimental studies on electromagnetic hypersensitivity have been criticized regarding inflexibility of choice of exposure and of study locations. We developed and tested novel portable exposure units that can generate different output levels of various extremely low frequency magnetic fie

  3. The Development of Testing Methods for Characterizing Emissions and Sources of Exposures from Polyurethane Products

    Science.gov (United States)

    The relationship between onsite manufacture of spray polyurethane foam insulation (SPFI) and potential exposures is not well understood. Currently, no comprehensive standard test methods exist for characterizing and quantifying product emissions. Exposures to diisocyanate compoun...

  4. The Development of Testing Methods for Characterizing Emissions and Sources of Exposures from Polyurethane Products

    Science.gov (United States)

    The relationship between onsite manufacture of spray polyurethane foam insulation (SPFI) and potential exposures is not well understood. Currently, no comprehensive standard test methods exist for characterizing and quantifying product emissions. Exposures to diisocyanate compoun...

  5. Sunlight associated hyperthermia as a consistent and rapidly developing clinical sign in sheep intoxicated by St John's wort (Hypericum perforatum).

    Science.gov (United States)

    Bourke, C A

    2000-07-01

    To assess the usefulness of rectal temperature responses in Australian bred Merino sheep, following the oral administration of Hypericum perforatum (St John's wort), as an early indicator of Hypericum intolerance. Thirty-three Merino ewes were divided into three groups of 11. Each group was dosed with finely ground, dried, flowering growth stage H perforatum plant material at either 5.7, 4.0, or 2.85 g dry plant per kg live weight. This corresponded to 5.3, 3.7 and 2.65 mg hypericin per kg live weight, respectively. The sheep were dosed with a plant slurry by stomach tube and then exposed to bright sunlight for up to 5 h per day over successive days. Their clinical responses were observed and rectal temperature measured. Ingestion of H perforatum followed by exposure to bright sunlight frequently resulted in clinical signs attributable to skin irritation and central nervous effects, including an inappropriate increase in body temperature. A decrease in H perforatum ingestion from 5.7 to 2.85 g dry plant per kg live weight and a corresponding decrease in hypericin ingestion from 5.3 to 2.65 mg per kg live weight, was associated with a decrease in the severity of the clinical signs, including the severity of the hyperthermia. The rectal temperature rise in affected sheep is a reliable indicator of the early development of an adverse clinical effect. There appears to be an absolute requirement for exposure to bright sunlight before any effects of H perforatum will develop. A single dose of H perforatum remains potentially effective for up to 4 days. In the small group of Merino sheep tested a tolerance level for H perforatum, eaten at the flowering stage, of plant wet weight) of body weight and a tolerance level for hypericin of < 2.65 mg per kg live weight, were demonstrated.

  6. Why We Need More Nature at Work: Effects of Natural Elements and Sunlight on Employee Mental Health and Work Attitudes.

    Directory of Open Access Journals (Sweden)

    Mihyang An

    Full Text Available This study investigated the effects of natural elements and direct and indirect sunlight exposure on employee mental health and work attitudes. We recruited participants via an online panel from the United States and India, and analyzed data from 444 employees. Natural elements and sunlight exposure related positively to job satisfaction and organizational commitment, and negatively to depressed mood and anxiety. Direct sunlight was a dominant predictor of anxiety; indirect sunlight was a dominant predictor of depressed mood, job satisfaction, and organizational commitment. Natural elements buffered the relationship between role stressors and job satisfaction, depressed mood, and anxiety. We also found that depressed mood partially mediated the relationship between natural elements and job satisfaction. We discuss scientific and policy implications of these findings.

  7. Photochemical Transformation of Graphene Oxide in Sunlight

    Science.gov (United States)

    Graphene oxide (GO) is a graphene derivative that is more easily manufactured in large scale and used to synthesize reduced graphene oxide (rGO) with properties analogous to graphene. In this study, we investigate the photochemical fate of GO under sunlight conditions. The resu...

  8. Sunlight-stimulated phenylalanine ammonia-lyase (PAL) activity and anthocyanin accumulation in exocarp of ‘Mahajanaka’ mango

    OpenAIRE

    Kobkiat Saengnil

    2011-01-01

    The activity of phenylalanine ammonia-lyase (PAL) required for anthocyanin synthesis was stimulated by sunlight exposure resulting in the development of red colour in ‘Mahajanaka’ mango exocarp, which occurred only on the sunlight-exposed side of the fruit. The accumulation of anthocyanin was concurrent with the increase in PAL activity in the mature stage of the fruit. The exposed side of the fruit had higher PAL activity, endogenous sugar content, and anthocyanin accumulation than the unexp...

  9. Does assessment of personal exposure matter during experimental neurocognitive testing in MRI-related magnetic fields?

    NARCIS (Netherlands)

    van Nierop, Lotte E; Christopher-de Vries, Y.; Slottje, Pauline; Kromhout, Hans

    2015-01-01

    PURPOSE: To determine whether the use of quantitative personal exposure measurements in experimental research would result in better estimates of the associations between static and time-varying magnetic field exposure and neurocognitive test performance than when exposure categories were based sole

  10. Wintering birds avoid warm sunshine: predation and the costs of foraging in sunlight.

    Science.gov (United States)

    Carr, Jennie M; Lima, Steven L

    2014-03-01

    Wintering birds can gain significant thermal benefits by foraging in direct sunlight. However, exposure to bright sunlight might make birds easier to detect by predators and may also cause visual glare that can reduce a bird's ability to monitor the environment. Thus, birds likely experience a trade-off between the thermal benefits and predation-related costs of foraging in direct sunlight. To examine this possible thermoregulation-predation trade-off, we monitored the behavior of mixed-species flocks of wintering emberizid sparrows foraging in alternating strips of sunlight and shade. On average, these sparrows routinely preferred to forage in the shade, despite midday air temperatures as much as 30 °C below their thermoneutral zone. This preference for shade was strongest at relatively high temperatures when the thermal benefits of foraging in sunlight were reduced, suggesting a thermoregulation-predation trade-off. Glare could be reduced if birds faced away from the sun while feeding in direct sunlight, but we found that foraging birds tended to face southward (the direction of the sun). We speculate that other factors, such as the likely direction of predator approach, may explain this southerly orientation, particularly if predators use solar glare to their advantage during an attack. This interpretation is supported by the fact that birds had the weakest southerly orientation on cloudy days. Wintering birds may generally avoid foraging in direct sunlight to minimize their risk of predation. However, given the thermal benefits of sunshine, such birds may benefit from foraging in habitats that provide a mosaic of sunlit and shaded microhabitats.

  11. Natural sunlight shapes crude oil-degradingbacterial communities in northern Gulf of Mexico surface waters

    Directory of Open Access Journals (Sweden)

    Hernando P Bacosa

    2015-12-01

    Full Text Available Following the Deepwater Horizon (DWH spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 d under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters.

  12. The Seasonality of Tuberculosis, Sunlight, Vitamin D, and Household Crowding

    Science.gov (United States)

    Wingfield, Tom; Schumacher, Samuel G.; Sandhu, Gurjinder; Tovar, Marco A.; Zevallos, Karine; Baldwin, Matthew R.; Montoya, Rosario; Ramos, Eric S.; Jongkaewwattana, Chulanee; Lewis, James J.; Gilman, Robert H.; Friedland, Jon S.; Evans, Carlton A.

    2014-01-01

    Background. Unlike other respiratory infections, tuberculosis diagnoses increase in summer. We performed an ecological analysis of this paradoxical seasonality in a Peruvian shantytown over 4 years. Methods. Tuberculosis symptom-onset and diagnosis dates were recorded for 852 patients. Their tuberculosis-exposed cohabitants were tested for tuberculosis infection with the tuberculin skin test (n = 1389) and QuantiFERON assay (n = 576) and vitamin D concentrations (n = 195) quantified from randomly selected cohabitants. Crowding was calculated for all tuberculosis-affected households and daily sunlight records obtained. Results. Fifty-seven percent of vitamin D measurements revealed deficiency (<50 nmol/L). Risk of deficiency was increased 2.0-fold by female sex (P < .001) and 1.4-fold by winter (P < .05). During the weeks following peak crowding and trough sunlight, there was a midwinter peak in vitamin D deficiency (P < .02). Peak vitamin D deficiency was followed 6 weeks later by a late-winter peak in tuberculin skin test positivity and 12 weeks after that by an early-summer peak in QuantiFERON positivity (both P < .04). Twelve weeks after peak QuantiFERON positivity, there was a midsummer peak in tuberculosis symptom onset (P < .05) followed after 3 weeks by a late-summer peak in tuberculosis diagnoses (P < .001). Conclusions. The intervals from midwinter peak crowding and trough sunlight to sequential peaks in vitamin D deficiency, tuberculosis infection, symptom onset, and diagnosis may explain the enigmatic late-summer peak in tuberculosis. PMID:24596279

  13. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    Concentrated sunlight provides a novel approach to the study of the physical and electrical parameters of organic solar cells. The study of performance of organic solar cells at high solar concentrations provides insight into the physics, which cannot be studied with conventional solar simulators....... A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...... studies of polymers for organic solar cells. Degradation was monitored by the evolution of the UV-vis absorption over time. Varying the solar intensity from 1 to 200 suns, the degradation rates were increased by more than a factor of 100 relative to degradation at 1 simulated sun. 5 different polymers...

  14. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    Concentrated sunlight provides a novel approach to the study of the physical and electrical parameters of organic solar cells. The study of performance of organic solar cells at high solar concentrations provides insight into the physics, which cannot be studied with conventional solar simulators...... studies of polymers for organic solar cells. Degradation was monitored by the evolution of the UV-vis absorption over time. Varying the solar intensity from 1 to 200 suns, the degradation rates were increased by more than a factor of 100 relative to degradation at 1 simulated sun. 5 different polymers....... A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...

  15. Sunlight induced photo reactivity of drugs

    Energy Technology Data Exchange (ETDEWEB)

    Dallera, R.; Dondi, D.; Ricci, A.; Fasani, E.; Albini, A.

    2003-07-01

    The reactivity under natural light of some UVA-UVB photol able drugs belonging to the classes of fluoroquinolones, glucocortocosteroids, sunscreens and nitrophenyldihydropyridines has been investigated. The data suggest that exposition to sunlight for times ranging from some minutes to few hours at PSA is sufficient for promoting a high degradation in the drugs investigated. the chemical reactions are the same as observed under artificial UV light. (Author) 28 refs.

  16. Prenatal Marijuana Exposure and Intelligence Test Performance at Age 6

    Science.gov (United States)

    Goldschmidt, Lidush; Richardson, Gale A.; Willford, Jennifer; Day, Nancy L.

    2008-01-01

    A study was conducted on lower income population women who were moderate users of marijuana to examine the effects of prenatal marijuana exposure on children's intellectual development at the age of six. Results concluded that the Cognitive deficits noticed at the age of six were specific to verbal and quantitative reasoning and short-term memory.

  17. Prenatal Marijuana Exposure and Intelligence Test Performance at Age 6

    Science.gov (United States)

    Goldschmidt, Lidush; Richardson, Gale A.; Willford, Jennifer; Day, Nancy L.

    2008-01-01

    A study was conducted on lower income population women who were moderate users of marijuana to examine the effects of prenatal marijuana exposure on children's intellectual development at the age of six. Results concluded that the Cognitive deficits noticed at the age of six were specific to verbal and quantitative reasoning and short-term memory.

  18. To describe and control exposure in nanoecotoxicology tests

    DEFF Research Database (Denmark)

    Baun, Anders

    There is an urgent need for reliable and reproducible results of ecotoxicological experiments in order to identify, rank, and classify the environmental hazards of nanomaterials. Standardized methods and guideline tests traditionally used for chemicals are today recommended for the testing...... for testing of engineered nanoparticles in aquatic toxicity tests and their implications for risk assessment will be addressed in this presentation....

  19. Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

    Science.gov (United States)

    Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

    2011-01-01

    The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general diversity patterns, despite increased mutation levels at the single

  20. Persistence of Bacteroides ovatus under simulated sunlight irradiation

    KAUST Repository

    Dong, Shengkun

    2014-07-04

    Background: Bacteroides ovatus, a member of the genus Bacteroides, is considered for use in molecular-based methods as a general fecal indicator. However, knowledge on its fate and persistence after a fecal contamination event remains limited. In this study, the persistence of B. ovatus was evaluated under simulated sunlight exposure and in conditions similar to freshwater and seawater. By combining propidium monoazide (PMA) treatment and quantitative polymerase chain reaction (qPCR) detection, the decay rates of B. ovatus were determined in the presence and absence of exogenous photosensitizers and in salinity up to 39.5 parts per thousand at 27°C. Results: UVB was found to be important for B. ovatus decay, averaging a 4 log10 of decay over 6 h of exposure without the presence of extracellular photosensitizers. The addition of NaNO2, an exogenous sensitizer producing hydroxyl radicals, did not significantly change the decay rate of B. ovatus in both low and high salinity water, while the exogenous sensitizer algae organic matter (AOM) slowed down the decay of B. ovatus in low salinity water. At seawater salinity, the decay rate of B. ovatus was slower than that in low salinity water, except when both NaNO2 and AOM were present. Conclusion: The results of laboratory experiments suggest that if B. ovatus is released into either freshwater or seawater environment in the evening, 50% of it may be intact by the next morning; if it is released at noon, only 50% may be intact after a mere 5 min of full spectrum irradiation on a clear day. This study provides a mechanistic understanding to some of the important environmental relevant factors that influenced the inactivation kinetics of B. ovatus in the presence of sunlight irradiation, and would facilitate the use of B. ovatus to indicate the occurrence of fecal contamination.

  1. Colour Changes Evaluation of Freshly Cut Alder Veneers Under the Influence of Indoor Sunlight

    Directory of Open Access Journals (Sweden)

    Emilia Adela SALCA

    2011-03-01

    Full Text Available The paper presents an experimental study concerning the colour changes occurred on the surfaces ofblack alder veneers (Alnus glutinosa, obtained from a freshly cut (not treated log, after their exposure tosunlight and darkness, for 1 and 3 months, under indoor conditions.A Chroma Meter Konika Minolta CR-410 device was used for colour measurement.The colorimetric coordinates were recorded before and after the exposure, according to ISO 7724-2.The results highlight a significant decrease of colour lightness, right after the first month of sunlight exposure.The a* and b* colour coordinates showed an increasing tendency with increasing exposure time, whichsignifies a colour darkening under sunlight radiation that penetrates the window glass. Colour differenceswere noticed right after the first month of sunlight exposure, while under darkness conditions, a relativecolour constancy was noticed, the colour changes being less pronounced, but yet perceptible by the humaneye.The study results complete the colorimetric database of veneers used in furniture industry, but theyalso contribute to the rehabilitation of black alder as a wood species with a real potential of use in furnitureindustry.

  2. Stainless steel in coastal seawater: sunlight counteracts biologically enhanced cathodic kinetics.

    Science.gov (United States)

    Eashwar, M; Lakshman Kumar, A; Sreedhar, G; Kennedy, J; Suresh Bapu, R H

    2014-09-01

    The influence of sunlight of varying intensity on the performance of UNS S30400 stainless steel (SS) was explored under conditions of natural biofilm development in coastal seawater. In a series of tests performed outdoors under an opaque roof, a range of shades were fashioned to impart varied amounts of diurnal light. These were an ambient level where the underwater illumination was ~ 5% of full sunlight, two intermediate ranges of lighting with ~ 2.5% and ~ 1% of the daylight, and a condition of full darkness. In comparison with the dark, increments of sunlight rendered the SS progressively less aggressive as cathodes in galvanic couples with UNS C70600 alloy. Likewise, welded SS with pre-initiated localized corrosion sites exhibited substantially lower rates of propagation with light. Thus, biofilms and sunlight affected cathodic kinetics in opposite ways. Surface analytical tests showed that the accumulation of manganese (Mn) within the biofilms was small relative to reports from waters of lower salinity. These results not only reveal that extremely low amounts of sunlight are adequate to offset the microbial effect, but also highlight the lack of convincing evidence for Mn cycling as a potent mechanism for enhanced cathodic kinetics in full-strength seawater.

  3. Railway suicide attempts are associated with amount of sunlight in recent days.

    Science.gov (United States)

    Kadotani, Hiroshi; Nagai, Yumiko; Sozu, Takashi

    2014-01-01

    To assess the relationship between hours of sunlight and railway suicide attempts, 3-7 days before these attempts. All railway suicide attempts causing railway suspensions or delays of 30 min or more between 2002 and 2006. We used a linear probability model to assess this relationship. This study was conducted at Tokyo, Kanagawa, and Osaka prefectures in Japan. Data were collected from the railway delay incident database of the Japanese Railway Technical Research Institute and public weather database of the Japan Meteorological Agency. About 971 railway suicides attempts occurred between 2002 and 2006 in Tokyo, Kanagawa, and Osaka. Less sunlight in the 7 days leading up to the railway suicide attempts was associated with a higher proportion of attempts (p=0.0243). Sunlight over the 3 days before an attempt had a similar trend (p=0.0888). No difference was found in sunlight hours between the days with (median: 5.6 [IQR: 1.1-8.8]) and without (median: 5.7 [IQR: 1.0-8.9]) railway suicide attempts in the evening. Finally, there was no apparent correlation between the railway suicide attempts and the monthly average sunlight hours of the attempted month or those of a month before. Railway suicides were not the main suicidal methods in Japan, We observed an increased proportion of railway suicide attempts after several days without sunlight. Light exposure (blue light or bright white light) in trains may be useful in reducing railway suicides, especially when consecutive days without sunshine are forecasted. © 2013 Elsevier B.V. All rights reserved.

  4. Photolysis of brominated flame retardants in textiles exposed to natural sunlight.

    Science.gov (United States)

    Kajiwara, Natsuko; Desborough, Jennifer; Harrad, Stuart; Takigami, Hidetaka

    2013-03-01

    Photolytic transformation profiles of technical hexabromocyclododecane (HBCD) and technical decabromodiphenyl ether (DecaBDE) in flame-retarded textiles exposed to natural sunlight were compared. Textiles that contained approximately 4% HBCDs by weight showed no substantial loss of any of the HBCD diastereomers during the entire exposure period (371 days), indicating that they were resistant to sunlight, that is, that debromination and isomerization of HBCD diastereomers did not occur under the experimental conditions. Exposure of a textile treated with technical DecaBDE resulted in the formation of polybrominated dibenzofurans (PBDFs) as products of photodecomposition of polybrominated diphenyl ethers present in the technical DecaBDE. After 329 days of exposure, the total PBDF concentration reached a maximum of 27 000 ng g(-1), which was approximately 10 times the initial concentration. During the experiment, di- to hexa-BDF congener concentrations increased continuously. Although the concentrations of PBDFs in the textiles were 4–5 orders of magnitude lower than the concentrations of polybrominated diphenyl ethers, it is important to note that PBDFs were formed as a result of sunlight exposure during normal use of products treated with technical DecaBDE.

  5. 40 CFR 158.1010 - Applicator exposure-criteria for testing.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Applicator exposure-criteria for testing. 158.1010 Section 158.1010 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Human Exposure § 158.1010 Applicator...

  6. Analysis of daylight performance of solar light pipes influenced by size and shape of sunlight captures

    Science.gov (United States)

    Wu, Yanpeng; Jin, Rendong; Zhang, Wenming; Liu, Li; Zou, Dachao

    2009-11-01

    Experimental investigations on three different sunlight captures with diameter 150mm, 212mm, 300mm were carried out under different conditions such as sunny conditions, cloudy conditions and overcast conditions and the two different size solar light pipes with diameter 360mm and 160mm under sunny conditions. The illuminance in the middle of the sunlight capture have relationship with its size, but not linear. To improve the efficiency of the solar light pipes, the structure and the performance of the sunlight capture must be enhanced. For example, University of Science and Technology Beijing Gymnasium, Beijing 2008 Olympic events of Judo and Taekwondo, 148 solar light pipes were installed with the diameter 530mm for each light pipe. Two sunlight captures with different shape were installed and tested. From the measuring results of the illuminance on the work plane of the gymnasium, the improvement sunlight captures have better effects with the size of augmenting and the machining of the internal surface at the same time, so that the refraction increased and the efficiency of solar light pipes improved. The better effects of supplementary lighting for the gymnasium have been achieved.

  7. Comportamento relativo à exposição e proteção solar na população de 15 anos ou mais de 15 capitais brasileiras e Distrito Federal, 2002-2003 Behaviors related to sunlight exposure versus protection in a random population sample from 15 Brazilian State capitals and the Federal District, 2002-2003

    Directory of Open Access Journals (Sweden)

    André Salem Szklo

    2007-04-01

    Full Text Available Este artigo explora a relação entre variáveis sócio-demográficas e comportamentais com proteção solar, levando-se em consideração as diferenças regionais existentes. Um inquérito de base populacional foi realizado em 15 capitais brasileiras e Distrito Federal, e as informações sobre exposição solar foram coletadas para um total de 16.999 indivíduos de 15 anos ou mais. Quando comparamos os indivíduos residentes nas regiões Norte e Sul do país, as diferenças brutas entre mulheres e homens nas proporções de utilização do protetor solar e do chapéu foram, respectivamente, para a Região Norte, +10,9% (IC95%: 7,1; 14,6 e -11,6% (IC95%: -17,0; -6,3, e Sul do país, +21,3% (IC95%: 17,7; 24,9 e -16,0% (IC95%: -20,2; -12,5. As diferenças ajustadas confirmaram que, tanto no Norte quanto no Sul do país, as mulheres mais freqüentemente utilizaram como proteção o filtro solar e menos freqüentemente referiram o uso de chapéu do que os homens. Contudo, essas diferenças não foram homogêneas entre as re- giões (termos de interação p This article examines region-specific relations between prevalence of protection against sunlight and socio-demographic and behavioral variables in Brazil. Data were derived from a cross-sectional population-based random sample. Information on sunlight exposure was available for a total of 16,999 individuals 15 years and older. Comparing the North and South of Brazil, crude differences between women and men in the use of "sunscreen" and "protective headwear" were +10.9% (95%CI: 7.1; 14.6 and -11.6% (95%CI: -17.0; -6.3 in the North and +21.3% (95%CI: 17.7; 24.9 and -16.0% (95%CI: -20.2; -12.5 in the South. Adjusted differences by selected variables confirmed that women use more sunscreen protection and less headwear protection as compared to men in both the North and South, but the difference was not homogeneous by region (interaction term p value < 0.05.

  8. Effects of Accelerated Exposure Testing (AET) Conditions on Performance Degradation of Solar Cells and Encapsulants

    Energy Technology Data Exchange (ETDEWEB)

    Glick, S. H.; Pern, F. J.

    2000-01-01

    The paper briefly summarizes the results from several accelerated exposure tests (AET) studies. Causes responsible for the photothermal instability of the encapsulated Si solar cells appear to be multiple and complex.

  9. HESI pilot project: Testing a qualitative approach for incorporating exposure into alternatives assessment

    DEFF Research Database (Denmark)

    Greggs, Bill; Arnold, Scott; Burns, Thomas J.;

    Committee, which consists of scientists from academia, industry, government, and NGOs, has developed a qualitative comparative exposure approach. Conducting such a comparison can screen for alternatives that are expected to have a higher exposure potential, which could trigger a higher-tiered, more-quantitative...... exposure assessment on the alternatives being considered. This talk will demonstrate an approach for including chemical and product exposure information in a qualitative AA comparison. Starting from existing hazard AAs, a series of four exposure examples were examined to test the concept, to understand...... the effort required, and to determine the value of exposure data in AA decision-making. The group has developed ingredient and product parameter categorization to support comparisons between chemicals and methodology to address data quality. The ingredient parameters include a range of physicochemical...

  10. Combined Space Environmental Exposure Tests of Multi-Junction GaAs/Ge Solar Array Coupons

    Science.gov (United States)

    Hoang, Bao; Wong, Frankie; Corey, Ron; Gardiner, George; Funderburk, Victor V.; Gahart, Richard; Wright, Kenneth H.; Schneider, Todd; Vaughn, Jason

    2010-01-01

    A set of multi-junction GaAs/Ge solar array test coupons were subjected to a sequence of 5-year increments of combined environmental exposure tests. The purpose of this test program is to understand the changes and degradation of the solar array panel components, including its ESD mitigation design features in their integrated form, after multiple years (up to 15) of simulated geosynchronous space environment. These tests consist of: UV radiation, electrostatic discharge (ESD), electron/proton particle radiation, thermal cycling, and ion thruster plume exposures. The solar radiation was produced using a Mercury-Xenon lamp with wavelengths in the UV spectrum ranging from 230 to 400 nm. The ESD test was performed in the inverted-gradient mode using a low-energy electron (2.6 - 6 keV) beam exposure. The ESD test also included a simulated panel coverglass flashover for the primary arc event. The electron/proton radiation exposure included both 1.0 MeV and 100 keV electron beams simultaneous with a 40 keV proton beam. The thermal cycling included simulated transient earth eclipse for satellites in geosynchronous orbit. With the increasing use of ion thruster engines on many satellites, the combined environmental test also included ion thruster exposure to determine whether solar array surface erosion had any impact on its performance. Before and after each increment of environmental exposures, the coupons underwent visual inspection under high power magnification and electrical tests that included characterization by LAPSS, Dark I-V, and electroluminescence. This paper discusses the test objective, test methodologies, and preliminary results after 5 years of simulated exposure.

  11. Preventive role of lens antioxidant defense mechanism against riboflavin-mediated sunlight damaging of lens crystallins.

    Science.gov (United States)

    Anbaraki, Afrooz; Khoshaman, Kazem; Ghasemi, Younes; Yousefi, Reza

    2016-10-01

    The main components of sunlight reaching the eye lens are UVA and visible light exerting their photo-damaging effects indirectly by the aid of endogenous photosensitizer molecules such as riboflavin (RF). In this study, lens proteins solutions were incubated with RF and exposed to the sunlight. Then, gel mobility shift analysis and different spectroscopic assessments were applied to examine the structural damaging effects of solar radiation on these proteins. Exposure of lens proteins to direct sunlight, in the presence of RF, leads to marked structural crosslinking, oligomerization and proteolytic instability. These structural damages were also accompanied with reduction in the emission fluorescence of Trp and Tyr and appearance of a new absorption peak between 300 and 400nm which can be related to formation of new chromophores. Also, photo-oxidation of lens crystallins increases their oligomeric size distribution as examined by dynamic light scattering analysis. The above mentioned structural insults, as potential sources of sunlight-induced senile cataract and blindness, were significantly attenuated in the presence of ascorbic acid and glutathione which are two important components of lens antioxidant defense system. Therefore, the powerful antioxidant defense mechanism of eye lens is an important barrier against molecular photo-damaging effects of solar radiations during the life span. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Inactivation of enteropathogenic E. coli by solar disinfection (SODIS) under simulated sunlight conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ubomba-Jaswa, E; Boyle, M A R; McGuigan, K G [Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2 (Ireland)], E-mail: kmcguigan@rcsi.ie

    2008-02-01

    Solar Disinfection (SODIS) is a low cost water treatment method currently used in communities that do not have year round access to safe water. However, there is still reluctance in widespread adoption of this treatment method due to a number of limitations. An important limitation is the lack of SODIS inactivation studies on some waterborne pathogens in the developing world. SODIS inactivation of enteropathogenic E. coli (EPEC), a major cause of infantile diarrhoea is reported for the first time under simulated sunlight conditions and following a natural temperature profile. EPEC was exposed to simulated sunlight (885Wm{sup -2}) for periods up to a cumulative time of 4 hours. Inactivation was determined by a log reduction in growth of the organisms. The temperature (deg. C) of the water was taken at every time point. After 4 hours exposure EPEC was completely inactivated (7 log reduction) by SODIS. Imposing a realistic water temperature profile (min-max) concomitant with irradiation produces a greater kill of EPEC. Maintaining simulated sunlight experiments at a high fixed temperature may result in over-estimation of inactivation. Following a natural water temperature profile will result in more reliable inactivation comparable with those that might be obtained under natural sunlight conditions.

  13. Inactivation of enteropathogenic E. coli by solar disinfection (SODIS) under simulated sunlight conditions

    Science.gov (United States)

    Ubomba-Jaswa, E.; Boyle, M. A. R.; McGuigan, K. G.

    2008-02-01

    Solar Disinfection (SODIS) is a low cost water treatment method currently used in communities that do not have year round access to safe water. However, there is still reluctance in widespread adoption of this treatment method due to a number of limitations. An important limitation is the lack of SODIS inactivation studies on some waterborne pathogens in the developing world. SODIS inactivation of enteropathogenic E. coli (EPEC), a major cause of infantile diarrhoea is reported for the first time under simulated sunlight conditions and following a natural temperature profile. EPEC was exposed to simulated sunlight (885Wm-2) for periods up to a cumulative time of 4 hours. Inactivation was determined by a log reduction in growth of the organisms. The temperature (°C) of the water was taken at every time point. After 4 hours exposure EPEC was completely inactivated (7 log reduction) by SODIS. Imposing a realistic water temperature profile (min-max) concomitant with irradiation produces a greater kill of EPEC. Maintaining simulated sunlight experiments at a high fixed temperature may result in over --estimation of inactivation. Following a natural water temperature profile will result in more reliable inactivation comparable with those that might be obtained under natural sunlight conditions.

  14. Photocatalytic oxidation of ciprofloxacin under simulated sunlight.

    Science.gov (United States)

    Gad-Allah, Tarek A; Ali, Mohamed E M; Badawy, Mohamed I

    2011-02-15

    Ciprofloxacin (CIP) is a famous synthetic chemotherapeutic antibiotic. It is widely found either in water or wastewater. In this study ciprofloxacin was photocatalytically degraded using commercial anatase titanium dioxide (TiO(2)) under simulated sunlight. The rate of reaction was found to be affected by pH, TiO(2) concentration and antibiotic concentration. The best reaction rate was obtained in natural ciprofloxacin pH (5.8) and 1000 mg/L TiO(2). More titania concentration was found to reduce the reaction rate because of the limitation in light transmittance. From kinetic studies, the reaction was proved to proceed through adsorption step then photooxidation and obeys pseudo-first order kinetics. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Testing a model of exposure to environmental tobacco smoke in military women with children.

    Science.gov (United States)

    Martinelli, Angela M; Agazio, Janice; Flaherty, Norma; Ephraim, Paula M

    2002-02-01

    The purpose of this study was to test a model of exposure to environmental tobacco smoke (ETS) in military women and their children. The convenience sample consisted of 238 women, 81 smokers and 157 nonsmokers, with a mean age of 37 years (SD = 9.9). Participants were either on active duty or were reservists and/or military dependents. Model constructs, some of which were adapted from the transtheoretical model of behavior change, measured personal and situational factors, pros and cons of ETS exposure, self-efficacy to resist ETS, mother's expectation for child's ETS exposure, and mother's self-efficacy to reduce child's ETS exposure. The mediating variable was the mother's daily ETS exposure, and the outcome variable was the child's daily ETS exposure. The trimmed model showed that 32% of the variance in mother's daily exposure (mediating variable) was accounted for by living with a smoker, having high ETS "pros" (as opposed to ETS "cons"), having less self-efficacy to resist ETS, and having greater self-efficacy to reduce the child's exposure. There was a significant, positive relationship (r = 0.51, p = 0.01) between the mother's and child's daily ETS exposure (outcome variable).

  16. Electrostatic Discharge Test of Multi-Junction Solar Array Coupons After Combined Space Environmental Exposures

    Science.gov (United States)

    Wright, Kenneth H.; Schneider, Todd; Vaughn, Jason; Hoang, Bao; Funderburk, Victor V.; Wong, Frankie; Gardiner, George

    2010-01-01

    A set of multi-junction GaAs/Ge solar array test coupons were subjected to a sequence of 5-year increments of combined environmental exposure tests. The test coupons capture an integrated design intended for use in a geosynchronous (GEO) space environment. A key component of this test campaign is conducting electrostatic discharge (ESD) tests in the inverted gradient mode. The protocol of the ESD tests is based on the ISO/CD 11221, the ISO standard for ESD testing on solar array panels. This standard is currently in its final review with expected approval in 2010. The test schematic in the ISO reference has been modified with Space System/Loral designed circuitry to better simulate the on-orbit operational conditions of its solar array design. Part of the modified circuitry is to simulate a solar array panel coverglass flashover discharge. All solar array coupons used in the test campaign consist of 4 cells. The ESD tests are performed at the beginning of life (BOL) and at each 5-year environment exposure point. The environmental exposure sequence consists of UV radiation, electron/proton particle radiation, thermal cycling, and ion thruster plume. This paper discusses the coverglass flashover simulation, ESD test setup, and the importance of the electrical test design in simulating the on-orbit operational conditions. Results from 5th-year testing are compared to the baseline ESD characteristics determined at the BOL condition.

  17. Segmental hair testing to disclose chronic exposure to psychoactive drugs.

    Science.gov (United States)

    Marchei, Emilia; Palmi, Ilaria; Pichini, Simona; Pacifici, Roberta; Anton Airaldi, Ileana-Rita; Costa Orvay, Juan Antonio; García Serra, Joan; Bonet Serra, Bartolomé; García-Algar, Óscar

    2016-06-15

    This study presents the case of a 4-year-old healthy child admitted to the paediatric ward for suspected accidental intoxication due to ingestion of narcoleptic drugs (methylphenidate, sertraline and quetiapine), taken on a regular basis by his 8-year-old brother affected by Asperger syndrome.Intoxication can be objectively assessed by measurements of drugs and metabolites in biological matrices with short-term (blood and urine) or long-term (hair) detection windows. At the hospital, the child's blood and urine were analysed by immunoassay (confirmed by liquid chromatography-mass spectrometry), and sertraline and quetiapine and their metabolites were identified. The suspicion that the mother administered drugs chronically prompted the analysis of six, consecutive 2-cm segments of the child's hair, using ultra-high performance liquid chromatography-tandem mass spectrometry, thereby accounting for ingestion over the previous 12 months. Quetiapine was found in the first four segments with a mean concentration of 1.00 ng/mg ± 0.94 ng/mg hair while sertraline and its metabolite, desmethyl-sertraline, were found in all segments with a mean concentration of 2.65 ± 0.94 ng/mg and 1.50 ± 0.94 ng/mg hair, respectively. Hair analyses were negative for methylphenidate and its metabolite (ritalinic acid). Biological matrices testing for psychoactive drugs disclosed both acute and chronic intoxication with quetiapine and sertraline administered by the mother.

  18. Photo-induced toxicity of titanium dioxide nanoparticles to Daphnia magna under natural sunlight.

    Science.gov (United States)

    Mansfield, C M; Alloy, M M; Hamilton, J; Verbeck, G F; Newton, K; Klaine, S J; Roberts, A P

    2015-02-01

    Titanium dioxide nanoparticles (TiO2 NP) are one of the most abundantly utilized nanoparticles in the world. Studies have demonstrated the ability of the anatase crystal of TiO2 NP to produce reactive oxygen species (ROS) in the presence of ultraviolet radiation (UVR), a co-exposure likely to occur in aquatic ecosystems. The goal of this study was to examine the photo-induced toxicity of anatase TiO2 NP under natural sunlight to Daphnia magna. D. magna were exposed to a range of UVR intensities and anatase TiO2 concentrations in an outdoor exposure system using the sun as the source of UVR. Different UVR intensities were achieved using UVR opaque and transparent plastics. AnataseTiO2-NP demonstrated the reciprocal relationship seen in other phototoxic compounds such as polycyclic aromatic hydrocarbons (PAHs) at higher UVR treatments. The calculated 8h LC50 of anatase TiO2 NP was 139 ppb under full intensity ambient natural sunlight, 778 ppb under 50% natural sunlight, and >500 ppm under 10% natural sunlight. Mortality was also compared between animals allowed to accumulate a body burden of anatase TiO2 for 1h and organisms whose first exposure to anatase TiO2 aqueous suspensions occurred under UVR. A significantly greater toxic effect was observed in aqueous, low body burden suspensions than that of TiO2 1h body burdens, which is dissimilar from the model presented in PAHs. Anatase TiO2 presents a unique photo-induced toxic model that is different than that of established phototoxic compounds.

  19. Photodegradation of malachite green under natural sunlight irradiation: kinetic and toxicity of the transformation products.

    Science.gov (United States)

    Pérez-Estrada, L A; Agüera, A; Hernando, M D; Malato, S; Fernández-Alba, A R

    2008-02-01

    This article describes the photolytic degradation of malachite green (MG), a cationic triphenylmethane dye used worldwide as a fungicide and antiseptic in the aquaculture industry. Photolysis experiments were performed by direct exposure of a solution of MG in water to natural sunlight. The main transformation products (TPs) generated during the process were identified by liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) and gas chromatography mass spectrometry (GC-MS). The 28 TPs identified with this strategy indicate that MG undergoes three main reactions, N-demethylation, hydroxylation and cleavage of the conjugated structure forming benzophenone derivatives. These processes involve hydroxyl radical attack on the phenyl ring, the N,N-dimethylamine group and the central carbon atom. The Vibrio fischeri acute toxicity test showed that the solution remains toxic after MG has completely disappeared. This toxicity could be assigned, at least in part, to the formation of 4-(dimethylamine)benzophenone, which has an EC(50,30 min) of 0.061 mg l(-1), and is considered "very toxic to aquatic organisms" by current EU legislation.

  20. Evaluation of the filter paper IP-10 tests in school children after exposure to tuberculosis

    DEFF Research Database (Denmark)

    Tuuminen, Tamara; Salo, Eeva; Kotilainen, Hannele

    2012-01-01

    The prevalence of active tuberculosis (TB) is low in Finland, but outbreaks do occur. Following exposure national guidelines recommend either tuberculosis skin test or interferon-γ-release assay-testing of asymptomatic children. The aim of this study was to compare QuantiFERON-TB Gold In-Tube tes...

  1. Sensitivity of continuous performance test (CPT) at age 14years to developmental methylmercury exposure

    DEFF Research Database (Denmark)

    Julvez, Jordi; Debes, Frodi; Weihe, Pal

    2010-01-01

    different time intervals after test initiation. A total of 878 adolescents (87% of birth cohort members) completed the CPT. The RT latencies were recorded for 10min, with visual targets presented at 1000ms intervals. After confounder adjustment, regression coefficients showed that CPT-RT outcomes differed...... in their associations with exposure biomarkers of prenatal methylmercury exposure: During the first 2min, the average HRT was weakly associated with methylmercury (beta (SE) for a ten-fold increase in exposure, (3.41 (2.06)), was strongly for the 3-to-6min interval (6.10 (2.18)), and the strongest during 7-10min after...

  2. Unconsented HIV testing in cases of occupational exposure: ethics, law, and policy.

    Science.gov (United States)

    Cowan, Ethan; Macklin, Ruth

    2012-10-01

    Postexposure prophylaxis (PEP) has substantially reduced the risk of acquiring human immunodeficiency virus (HIV) after an occupational exposure; nevertheless, exposure to HIV remains a concern for emergency department providers. According to published guidelines, PEP should be taken only when source patients are HIV-positive or have risk factors for HIV. Initiating PEP when source patients are uninfected puts exposed persons at risk from taking toxic drugs with no compensating benefit. Forgoing PEP if the source is infected results in increased risk of acquiring HIV. What should be done if source patients refuse HIV testing? Is it justifiable to test the blood of these patients over their autonomous objection? The authors review current law and policy and perform an ethical analysis to determine if laws permitting unconsented testing in cases of occupational exposure can be ethically justified. © 2012 by the Society for Academic Emergency Medicine.

  3. The assessment of radiation exposures in native American communities from nuclear weapons testing in Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Frohmberg, E.; Goble, R.; Sanchez, V.; Quigley, D.

    2000-02-01

    Native Americans residing in a broad region downwind from the Nevada Test Site during the 1950s and 1960s received significant radiation exposures from nuclear weapons testing. Because of differences in diet, activities, and housing, their radiation exposures are only very imperfectly represented in the Department of Energy dose reconstructions. There are important missing pathways, including exposures to radioactive iodine from eating small game. The dose reconstruction model assumptions about cattle feeding practices across a year are unlikely to apply to the native communities as are other model assumptions about diet. Thus exposures from drinking milk and eating vegetables have not yet been properly estimated for these communities. Through consultations with members of the affected communities, these deficiencies could be corrected and the dose reconstruction extended to Native Americans. An illustration of the feasibility of extending the dose reconstruction is provided by a sample calculation to estimate radiation exposures to the thyroid from eating radio-iodine-contaminated rabbit thyroids after the Dedan test. The illustration is continued with a discussion of how the calculation results may be used to make estimates for other tests and other locations.

  4. Photocatalytic degradation of synthetic dye under sunlight

    Directory of Open Access Journals (Sweden)

    Mijin Dušan

    2007-01-01

    Full Text Available Synthetic dyes are widely used in the textile industry. Dye pollutants from the textile industry are an important source of environmental contamination. The majority of these dyes are toxic, mostly non-biodegradable and also resistant to decomposition by physico-chemical methods. Among new oxidation methods or "advanced oxidation processes", heterogeneous photocatalysis appears as an emerging destructive technology leading to the total mineralization of many organic pollutants. CI Basic Yellow 28 (BY28, commonly used as a textile dye, could be photocatalytically degraded using TiU2 as catalyst under sunlight. The effect of some parameters such as the initial catalyst concentration, initial dye concentration, initial NaCl and Na2CO3 concentrations, pH, H2O2 and type of catalyst on the degradation rate of BY28 was examined in details. The presence of NaCl and Na2CO3 led to inhibition of the photodegradation process. The highest photodegradation rate was observed at high pH, while the rate was the lowest at low pH. Increase of the initial H2O2 concentration increased the initial BY28 photodegradation efficiency. ZnO was a better catalyst than TiO2 at low dye concentrations.

  5. Hypoxia Stress Test Reveals Exaggerated Cardiovascular Effects in Hypertensive Rats after Exposure to the Air Pollutant Acrolein

    Science.gov (United States)

    Exposure to air pollution increases the risk of cardiovascular morbidity and mortality, especially in susceptible populations with cardiovascular disease. Stress tests are useful in assessing cardiovascular risk and manifesting latent effects of exposure. The goal of this study w...

  6. Catalase Activity in Brown Mussels (Perna perna) under Acute Cadmium, Lead, and Copper Exposure and Depuration Tests

    National Research Council Canada - National Science Library

    Boudjema, Kamel; Kourdali, Sidali; Bounakous, Nabila; Meknachi, Abdellah; Badis, Abdelmalek

    2014-01-01

      Brown mussels (Perna perna) were exposed to cadmium (Cd), lead (Pb), and copper (Cu) concentrations under acute exposure and exposure-depuration tests for the estimation of biochemical biomarker catalase...

  7. Degradation of methyl and ethyl mercury by singlet oxygen generated from sea water exposed to sunlight or ultraviolet light.

    Science.gov (United States)

    Suda, I; Suda, M; Hirayama, K

    1993-01-01

    Photodegradation of methyl mercury (MeHg) and ethyl Hg (EtHg) in sea water was studied by sunlight or ultraviolet (UV) light exposure, and by determining inorganic Hg produced by degradation. Sea water containing 1 microM MeHg or EtHg was exposed to sunlight or UV light. N-Acetyl-L-cysteine was added to the solution for preventing Hg loss during the light exposure. MeHg and EtHg in sea water were degraded by sunlight (> 280 nm), UV light A (320-400 nm) and UV light B (280-320 nm), though the amounts of inorganic Hg produced from MeHg were 1/6th to 1/12th those from EtHg. Inorganic Hg production was greater with increasing concentration of sea water. Degradation of MeHg and EtHg by the UV light A exposure was inhibited by singlet oxygen (1O2) trappers such as NaN3, 1,4-diazabicyclo[2,2,2]octane, histidine, methionine and 2,5-dimethylfuran. On the other hand, inhibitors or scavengers of superoxide anion, hydrogen peroxide or hydroxyl radical did not inhibit the photodegradation of alkyl Hg. These results suggested that 1O2 generated from sea water exposed to sunlight, UV light A or UV light B was the reactive oxygen species mainly responsible for the degradation of MeHg and EtHg.

  8. Sunlight-Exposed Biofilm Microbial Communities Are Naturally Resistant to Chernobyl Ionizing-Radiation Levels

    Science.gov (United States)

    Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

    2011-01-01

    Background The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. Methodology/Principal Findings To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Conclusions/Significance Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general

  9. Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

    Directory of Open Access Journals (Sweden)

    Marie Ragon

    Full Text Available BACKGROUND: The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. METHODOLOGY/PRINCIPAL FINDINGS: To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta and ascomycete fungi (Ascomycota dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. CONCLUSIONS/SIGNIFICANCE: Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in

  10. Redox status of the testes and sperm of rats following exposure to 2,5-hexanedione.

    Science.gov (United States)

    Adedara, Isaac A; Abolaji, Amos O; Odion, Blessing E; Omoloja, Abiola A; Okwudi, Isioma J; Farombi, Ebenezer O

    2016-11-01

    Exposure to 2,5-hexanedione (2,5-HD) is well known to be associated with reproductive dysfunctions in both humans and animals. However, the role of oxidative stress in 2,5-HD-induced toxicity in testes and sperm has not yet been studied. The present study investigated the influence of 2,5-HD on antioxidant systems in the testes and epididymal sperm of rats following exposure to 0, 0.25, 0.5, and 1% 2,5-HD in drinking water for 21 consecutive days. Administration of 0.5% 2,5-HD significantly (P rats showed significantly decreased body weight, testis, and epididymis weights compared with the control group. Exposure to 2,5-HD caused a significant dose-dependent increase in the activities of superoxide dismutase, catalase, and glutathione peroxidase in both testes and sperm compared with the control group. Moreover, 2,5-HD-exposed rats showed significant decrease in glutathione-S-transferase activity and glutathione level with concomitant significant elevation in the levels of hydrogen peroxide and malondialdehyde in both testes and sperm. Testicular and epididymal atrophy with significant, dose-dependent, decrease in epididymal sperm number, sperm motility, and viability were observed in 2,5-HD-treated rats. 2,5-HD exposure impaired testicular function and sperm characteristics by disruption of the antioxidant systems and consequently, increased oxidative stress in the treated rats.

  11. Matching marine corrosion: new accelerated test gives good correlation with outdoor exposure

    NARCIS (Netherlands)

    Hoeflaak, M.

    2004-01-01

    An extensive study of the corrosion resistance of a large number and a large variety of coatings systems for steel protection has been carried out. With these, three types of accelerated tests have been correlated with observerations from two years of outdoor exposure in a marine environment, and a

  12. Controlling silver nanoparticle exposure in algal toxicity testing - A matter of timing

    DEFF Research Database (Denmark)

    Sørensen, Sara Nørgaard; Baun, Anders

    2015-01-01

    The aquatic ecotoxicity testing of nanoparticles is complicated by unstable exposure conditions resulting from various transformation processes of nanoparticles in aqueous suspensions. In this study, we investigated the influence of exposure timing on the algal test response to silver nanoparticles......) in a standard algal growth inhibition test (ISO 8692:2004) for 48 h and a short-term (2 h) 14C-assimilation test. For AgNO3, similar responses were obtained in the two tests, whereas freshly prepared suspensions of citrate stabilized AgNPs were less toxic in the 2-h tests compared to the 48-h tests. The 2-h...... and reproducibility increased. Prolonged aging to 48 h increased toxicity in the 2-h tests whereas aging beyond 48 h reduced toxicity. Our results demonstrate that the outcome of algal toxicity testing of AgNPs is highly influenced not only by the test duration, but also by the time passed from the moment Ag...

  13. Active and realistic passive marijuana exposure tested by three immunoassays and GC/MS in urine

    Energy Technology Data Exchange (ETDEWEB)

    Mule, S.J.; Lomax, P.; Gross, S.J.

    1988-05-01

    Human urine samples obtained before and after active and passive exposure to marijuana were analyzed by immune kits (Roche, Amersham, and Syva) and gas chromatography/mass spectrometry (GC/MS). Seven of eight subjects were positive for the entire five-day test period with one immune kit. The latter correlated with GC/MS in 98% of the samples. Passive inhalation experiments under conditions likely to reflect realistic exposure resulted consistently in less than 10 ng/mL of cannabinoids. The 10-100-ng/mL cannabinoid concentration range essential for detection of occasional and moderate marijuana users is thus unaffected by realistic passive inhalation.

  14. Sunlight creates oxygenated species in water-soluble fractions of Deepwater horizon oil

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Phoebe Z. [Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States); Chen, Huan [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Podgorski, David C. [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Future Fuels Institute, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); McKenna, Amy M. [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Tarr, Matthew A., E-mail: mtarr@uno.edu [Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States)

    2014-09-15

    Graphical abstract: Sunlight oxygenates petroleum. - Highlights: • Oxidation seen in water-soluble oil fraction after exposure to simulated sunlight. • Oxygen addition occurred across a wide range of carbon number and DBE. • Oil compounds were susceptible to addition of multiple oxygens to each molecule. • Results provide understanding of fate of oil on water after exposure to sunlight. - Abstract: In order to assess the impact of sunlight on oil fate, Macondo well oil from the Deepwater Horizon (DWH) rig was mixed with pure water and irradiated with simulated sunlight. After irradiation, the water-soluble organics (WSO) from the dark and irradiated samples were extracted and characterized by ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Liquid–liquid extraction yielded two fractions from dark and irradiated water/oil mixtures: acidic WSOs (negative-ion electrospray (ESI)), and base/neutral WSOs (positive-ion ESI) coupled to FT-ICR MS to catalog molecular-level transformations that occur to Macondo-derived WSOs after solar irradiation. Such direct measure of oil phototransformation has not been previously reported. The most abundant heteroatom class detected in the irradiated WSO acid fractions correspond to molecules that contain five oxygens (O{sub 5}), while the most abundant acids in the dark samples contain two oxygen atoms per molecule (O{sub 2}). Higher-order oxygen classes (O{sub 5}–O{sub 9}) were abundant in the irradiated samples, but <1.5% relative abundance in the dark sample. The increased abundance of higher-order oxygen classes in the irradiated samples relative to the dark samples indicates that photooxidized components of the Macondo crude oil become water-soluble after irradiation. The base/neutral fraction showed decreased abundance of pyridinic nitrogen (N{sub 1}) concurrent with an increased abundance of N{sub 1}O{sub x} classes after irradiation. The predominance of higher

  15. Temporal trends in childhood leukaemia incidence following exposure to radioactive fallout from atmospheric nuclear weapons testing.

    Science.gov (United States)

    Wakeford, Richard; Darby, Sarah C; Murphy, Michael F G

    2010-05-01

    Notably raised rates of childhood leukaemia incidence have been found near some nuclear installations, in particular Sellafield and Dounreay in the United Kingdom, but risk assessments have concluded that the radiation doses estimated to have been received by children or in utero as a result of operations at these installations are much too small to account for the reported increases in incidence. This has led to speculation that the risk of childhood leukaemia arising from internal exposure to radiation following the intake of radioactive material released from nuclear facilities has been substantially underestimated. The radionuclides discharged from many nuclear installations are similar to those released into the global environment by atmospheric nuclear weapons testing, which was at its height in the late-1950s and early-1960s. Measurements of anthropogenic radionuclides in members of the general public resident in the vicinity of Sellafield and Dounreay have found levels that do not differ greatly from those in persons living remote from nuclear installations that are due to ubiquitous exposure to the radioactive debris of nuclear weapons testing. Therefore, if the leukaemia risk to children resulting from deposition within the body of radioactive material discharged from nuclear facilities has been grossly underestimated, then a pronounced excess of childhood leukaemia would have been expected as a consequence of the short period of intense atmospheric weapons testing. We have examined childhood leukaemia incidence in 11 large-scale cancer registries in three continents for which data were available at least as early as 1962. We found no evidence of a wave of excess cases corresponding to the peak of radioactive fallout from atmospheric weapons testing. The absence of a discernible increase in the incidence of childhood leukaemia following the period of maximum exposure to the radioactive debris of this testing weighs heavily against the suggestion that

  16. Dose-Response Effect of Sunlight on Vitamin D2 Production in Agaricus bisporus Mushrooms

    DEFF Research Database (Denmark)

    Urbain, Paul; Jakobsen, Jette

    2015-01-01

    The dose response effect of UV-B irradiation from sunlight on vitamin D2 content of sliced Agaricus bisporus (white button mushroom) during the process of sun-drying was investigated.Real-time UV-B and UV-A data were obtained using a high-performance spectroradiometer. During the first hour...... of sunlight exposure, the vitamin D2 content of the mushrooms increased in a linear manner, with concentrations increasing from 0.1 μg/g up to 3.9 ± 0.8 μg/g dry weight (DW). At the subsequent two measurements one and 3 h later, respectively, a plateau was reached. Two hours of additional exposure triggered...... a significant decline in vitamin D2 content. After just 15 min of sun exposure and an UV-B dose of 0.13 J/cm(2), the vitamin D2 content increased significantly to 2.2 ± 0.5 μg/g DW (P vitamin D2 per 100 g of fresh mushrooms and comparable to levels found...

  17. Dose-Response Effect of Sunlight on Vitamin D2 Production in Agaricus bisporus Mushrooms.

    Science.gov (United States)

    Urbain, Paul; Jakobsen, Jette

    2015-09-23

    The dose response effect of UV-B irradiation from sunlight on vitamin D2 content of sliced Agaricus bisporus (white button mushroom) during the process of sun-drying was investigated.Real-time UV-B and UV-A data were obtained using a high-performance spectroradiometer. During the first hour of sunlight exposure, the vitamin D2 content of the mushrooms increased in a linear manner, with concentrations increasing from 0.1 μg/g up to 3.9 ± 0.8 μg/g dry weight (DW). At the subsequent two measurements one and 3 h later, respectively, a plateau was reached. Two hours of additional exposure triggered a significant decline in vitamin D2 content. After just 15 min of sun exposure and an UV-B dose of 0.13 J/cm(2), the vitamin D2 content increased significantly to 2.2 ± 0.5 μg/g DW (P < 0.0001), which is equivalent to 17.6 μg (704 IU) vitamin D2 per 100 g of fresh mushrooms and comparable to levels found in fatty fish like the Atlantic salmon.

  18. Assessing nanomaterial exposures in aquatic ecotoxicological testing: Framework and case studies based on dispersion and dissolution.

    Science.gov (United States)

    Kennedy, Alan J; Coleman, Jessica G; Diamond, Stephen A; Melby, Nicolas L; Bednar, Anthony J; Harmon, Ashley; Collier, Zachary A; Moser, Robert

    2017-05-01

    The unique behavior of engineered nanomaterials (ENM) in aqueous media and dynamic changes in particle settling, agglomeration and dissolution rates is a challenge to the consistency, reliability and interpretation of standard aquatic hazard bioassay results. While the toxicological endpoints (e.g., survival, growth, reproduction, etc.) in ecotoxicity bioassays are largely applicable to ENMs, the standard methods as written for dissolved substances are confounded by the dynamic settling, agglomeration and dissolution of particulate ENMs during the bioassay. A testing framework was designed to serve as a starting point to identify approaches for the consistent conduct of aquatic hazard tests that account for the behavior of ENMs in test media and suitable data collection to support representative exposure metrology. The framework was demonstrated by conducting three case studies testing ENMs with functionally distinct characteristics and behaviors. Pretests with a temporal sampling of particle concentration, agglomeration and dissolution were conducted on each ENM in test media. Results indicated that a silver nanoparticle (AgNP) powder was not dispersible, a nano-TiO2 powder was dispersible but unstable, and a polyvinylpyrrolidinone-coated AgNP was relatively stable in test media. Based on these functional results, Ceriodaphnia dubia bioassays were conducted to compare different exposure summary methods (nominal, arithmetic average, geometric average, time-weighted average) for calculating and expressing toxicity endpoints. Results indicated that while arithmetic means were effective for expressing the toxicity of more stable materials, time-weighted averaged concentrations were appropriate for the unstable nano-TiO2.

  19. Measurements of pulse rate using long-range imaging photoplethysmography and sunlight illumination outdoors

    Science.gov (United States)

    Blackford, Ethan B.; Estepp, Justin R.

    2017-02-01

    Imaging photoplethysmography, a method using imagers to record absorption variations caused by microvascular blood volume pulsations, shows promise as a non-contact cardiovascular sensing technology. The first long-range imaging photoplethysmography measurements at distances of 25, 50, and 100 meters from the participant was recently demonstrated. Degraded signal quality was observed with increasing imager-to-subject distances. The degradation in signal quality was hypothesized to be largely attributable to inadequate light return to the image sensor with increasing lens focal length. To test this hypothesis, a follow-up evaluation with 27 participants was conducted outdoors with natural sunlight illumination resulting in 5-33 times the illumination intensity. Video was recorded from cameras equipped with ultra-telephoto lenses and positioned at distances of 25, 50, 100, and 150 meters. The brighter illumination allowed high-definition video recordings at increased frame rates of 60fps, shorter exposure times, and lower ISO settings, leading to higher quality image formation than the previous indoor evaluation. Results were compared to simultaneous reference measurements from electrocardiography. Compared to the previous indoor study, we observed lower overall error in pulse rate measurement with the same pattern of degradation in signal quality with respect to increasing distance. This effect was corroborated by the signal-to-noise ratio of the blood volume pulse signal which also showed decreasing quality with respect to increasing distance. Finally, a popular chrominance-based method was compared to a blind source separation approach; while comparable in measurement of signal-to-noise ratio, we observed higher overall error in pulse rate measurement using the chrominance method in this data.

  20. Pediatric Exposure to Drugs of Abuse by Hair Testing: Monitoring 15 Years of Evolution in Spain

    Directory of Open Access Journals (Sweden)

    Simona Pichini

    2014-08-01

    Full Text Available Hair testing is a useful tool to investigate the prevalence of unsuspected chronic exposure to drugs of abuse in pediatric populations and it has been applied to three different cohorts of children from Barcelona, Spain along fifteen years to evaluate eventual changes in this exposure. Children were recruited from three independent studies performed at Hospital del Mar (Barcelona, Spain and approved by the local Ethics Committee. Hair samples were collected from the first 187 children cohort (around 4 years of age in 1998, from the second 90 children cohort (1.5–5 years of age in 2008 and from the third 114 children cohort (5–14 years of age in 2013. Hair samples were analysed for the presence of opiates, cocaine, amphetamines, and cannabis by validated methodologies using gas or liquid chromatography-mass spectrometry. Familiar sociodemographics and eventual consumption of drugs of abuse by parents, and caregivers were recorded. Hair samples from 24.6% children in 1998 were positive for any drug of abuse (23.0% cocaine, 25.5% in 2008 (23.3% cocaine, and 28.1% in 2013 (20.1% cocaine and 11.4% cannabis. In none of the cohorts, parental sociodemographics were associated with children exposure to drugs of abuse. The results of the three study cohorts demonstrated a significant prevalence of unsuspected pediatric exposure to drugs of abuse which mainly involved cocaine maintained along fifteen years in Barcelona, Spain. We recommend to be aware about unsuspected passive exposure to drugs of abuse in general population and to use general or selected hair screening to disclose exposure to drugs of abuse in children from risky environments to provide the basis for specific social and health interventions.

  1. Exposure to the social interaction test in rats induces changes in defensive burying.

    Science.gov (United States)

    Saldívar-González, A; Hernández-León, M J; Mondragón-Ceballos, R

    1996-08-01

    To detect changes in experimental anxiety, defensive burying (DB) was studied in several groups of rats after being exposed to social interaction (SI). Animals were studied in the DB paradigm after being submitted to the following SI treatments: control (without SI exposure), and SI for 1.5, 5, 10 and 15 min respectively. A bimodal effect was found: facilitated DB response values in the group tested after a 1.5 min exposure to SI and a strong reduction of DB in the 10 and 15 min groups. The inhibition in DB elicited by the 15 min exposure to SI revealed a slow recovery, returning to control levels after 30 min. The actions of novelty on defensive burying were assessed in a third experiment. Animals were tested for DB immediately after being placed for 1.5 or 15 min in the SI arena without a partner. DB levels increased in these animals. Another group was placed in the SI arena for 1.5 min and tested in the DB paradigm 13.5 min after being returned to the home cage. A return to the basal control DB levels was observed in this group. Data are discussed in terms of anxiety-like fluctuations and the adaptive functions underlying these.

  2. Sensitized photoelectrolysis of water with sunlight. Final report, June 1, 1977-December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, A.K.; Maruska, H.P.

    1978-12-01

    A study was made of solar driven water photoelectrolysis cells employing semiconductor electrodes. An extensive review of the literature was undertaken, and the three major problem areas for these devices were identified: corrosion, poor sunlight absorption, and external bias requirement. Although many semiconductors had been tested, none had proven free of all three defects. Two approaches were thus followed for the experimental studies: impurity sensitization of wide band gap stable oxides, and heterostructure formation between unstable sunlight absorbers and corrosion resistant oxides. Water decomposition was achieved with visible light excitation of Cr-doped TiO/sub 2/. Transport properties were studies for TiO/sub 2/ and SrTiO/sub 3/ electrodes doped with V, Cr, Mn, Fe, Co, and Ni. The correlation between bias requirement and electron affinity of oxides was identified. Performance of heterostructure electrodes was shown to be limited either by pin hole problems or by potential barriers between the valence bands.

  3. Influence of test conditions and exposure duration on the result of ecotoxicological tests

    DEFF Research Database (Denmark)

    Rosenkrantz, Rikke Tjørnhøj

    Chemicals are used extensively and are part of many aspects of human life and society. They are useful and necessary for many purposes, but may also cause adverse effects on natural organisms if they are released to the environment during and after use. Therefore, it is necessary to perform a risk....../8/EC) or the Plant Protection Products Directive (EC 1107/2009). In addition to such risk assessment directives, the Water Framework Directive (2000/60/EC) has been adopted with the objective to protect and improve the quality of European waters and aquatic habitats. This requires, among other things...... be calculated from results of ecotoxicological tests performed according to internationally approved guidelines, such as from the Organisation for Economic Co-operation and Development (OECD) or International Standardization Organisation (ISO). Such guidelines were originally developed to enable classification...

  4. Design and testing of electrostatic aerosol in vitro exposure system (EAVES): An alternative exposure system for particles

    Science.gov (United States)

    Conventional in vitro exposure methods for cultured human lung cells rely on prior suspension of particles in a liquid medium; these have limitations for exposure intensity and may modify the particle composition. Here electrostatic precipitation was used as an effective method f...

  5. A high-throughput clinical assay for testing drug facilitation of exposure therapy.

    Science.gov (United States)

    Rodebaugh, Thomas L; Levinson, Cheri A; Lenze, Eric J

    2013-07-01

    Several studies have demonstrated that D-cycloserine (DCS) facilitates exposure therapy. We developed a standardized test of this facilitation (i.e., a clinical assay), with the goal of testing for facilitation more quickly and inexpensively than a full clinical trial. We developed a standardized brief exposure in which participants with social anxiety disorder gave a videotaped speech. Participants were randomized to receive a single capsule of 250 mg DCS or a matching placebo prior to preparation for the speech. Distress levels were rated during the speech and again, approximately 1 week later, during a speech in an identical situation. Our primary measure of DCS's exposure-facilitating effect was between-session habituation: whether or not the participants showed less distress during the second speech compared to the first. We also measured levels of subjective anxiety and fear of scrutiny. Subjects randomized to receive DCS prior to their first speech were more likely to show between-session habituation than those who received placebo. We also found greater reduction of performance-related fear overall in the DCS group. Our clinical assay was able to detect exposure facilitation effects rapidly and in a highly standardized way, and is estimated to take a fraction of the time and costs of a clinical trial. Given the increasing interest in using medications to enhance learning-based psychotherapy, this high-throughput clinical assay approach may be a favorable method for testing novel mechanisms of action, and clarifying optimal parameters, for therapy facilitation. © 2013 Wiley Periodicals, Inc.

  6. Testing Dust Control Preparation with Respect to Mine Employee Exposure to Inhalling Chemical Agents

    Directory of Open Access Journals (Sweden)

    Eugeniusz Orszulik

    2013-01-01

    Full Text Available This paper presents the results of tests used in dust hazard prevention for air-water spraying devices in collieries. The purpose of the tests was to evaluate mine employees’ exposure to inhalling chemical agents when the ZWILKOP ZW-10 preparation is used. The paper presents the results of the measurements of concentration, in a mine atmosphere, of the following chemical agents: hazardous substances 2-(2-butoxyethoxyethanol and 2-ethylhexan-1-ol, constituting ingredients of the preparation at mine employees’ workstations. The tests were performed during work related to the mining of coal in inclined drift C31, seam 415/1-2 on the premises of “Borynia-Zofiówka-Jastrzębie” Hard Coal Mine, Jastrzębie-Zdrój, Poland, using the TELESTO mist systems. Using aqueous solutions for the preparation at concentrations of 15 and 20‰ causes no exceedance of the allowable mine air concentrations for the chemical agents tested.

  7. Carbon nanohorns-based nanofluids as direct sunlight absorbers.

    Science.gov (United States)

    Sani, E; Barison, S; Pagura, C; Mercatelli, L; Sansoni, P; Fontani, D; Jafrancesco, D; Francini, F

    2010-03-01

    The optimization of the poor heat transfer characteristics of fluids conventionally employed in solar devices are at present one of the main topics for system efficiency and compactness. In the present work we investigated the optical and thermal properties of nanofluids consisting in aqueous suspensions of single wall carbon nanohorns. The characteristics of these nanofluids were evaluated in view of their use as sunlight absorber fluids in a solar device. The observed nanoparticle-induced differences in optical properties appeared promising, leading to a considerably higher sunlight absorption. We found that the thermal conductivity of the nanofluids was higher than pure water. Both these effects, together with the possible chemical functionalization of carbon nanohorns, make this new kind of nanofluids very interesting for increasing the overall efficiency of the sunlight exploiting device.

  8. Comparing interferon-gamma release assays to tuberculin skin test in Thai children with tuberculosis exposure.

    Directory of Open Access Journals (Sweden)

    Hong-Van Tieu

    Full Text Available Data on the performance of interferon-gamma release assays (IGRAs, QuantiFERON TB Gold In-tube (QFNGIT and T-Spot.TB, in diagnosing tuberculosis (TB are limited in Southeast Asia. This study aims to compare the performances of the two IGRAs and TST in Thai children with recent TB exposure.This multicenter, prospective study enrolled children with recent exposure to active TB adults. Children were investigated for active TB. TST was performed and blood collected for T-Spot.TB and QFNGIT.158 children were enrolled (87% TB-exposed and 13% active TB, mean age 7.2 years. Only 3 children had HIV infection. 66.7% had TST≥10 mm, while 38.6% had TST≥15 mm. 32.5% had positive QFNGIT; 29.9% had positive T-Spot.TB. QFNGIT and T-Spot.TB positivity was higher among children with active TB compared with TB-exposed children. No indeterminate IGRA results were detected. No statistically significant differences between the performances of the IGRAs and TST at the two cut-offs with increasing TB exposure were detected. Concordance for positive IGRAs and TST ranged from 42-46% for TST≥10 mm and 62-67% for TST≥15 mm. On multivariable analyses, exposure to household primary/secondary caregiver with TB was associated with positive QFNGIT. Higher TB contact score and active TB were associated with positive T-Spot.TB.Both QFNGIT and T-Spot.TB performed well in our Thai pediatric study population. No differences in the performances between tests with increasing TB exposure were found. Due to accessibility and low cost, using TST may more ideal than IGRAs in diagnosing latent and active TB in healthy children in Thailand and other similar settings.

  9. Request for a Test Exposure of OPERA Targets in the NuMI Beam

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, K.; /Aichi U.; Tzanakos, G.; /Athens U.; Baller, B.; Lundberg, B.; Rameika, R.; Saoulidou, N.; /Fermilab; Aoki, S.; /Kobe U.; Autiero, D.; Chaussard, L.; Caffari, Y.; Declais, Y.; /IPNL /Minnesota U. /Nagoya U. /Pittsburgh U.

    2004-11-01

    We request to use the Fermilab NuMI neutrino beam in the MINOS Near Detector Hall to produce neutrino interactions in two separate detector arrangements using prototype target bricks designed for the OPERA experiment. OPERA is scheduled to to begin taking data in the CERN Neutrinos to Gran Sasso (CNGS) beam in 2006. The proposed test set up would be located just upstream of the MINOS Near Detector. The data will be used to validate the OPERA analysis scheme and to study backward particle production in neutrino interactions, which is of interest to the OPERA collaboration as well as the neutrino community in general. In addition, we contend that the data taken in this exposure may also be useful to the MINOS collaboration as additional input to the understanding of the initial composition of the neutrino beam. Ideally, this exposure could take place in early to mid-2005, providing timely feedback to both the OPERA and MINOS collaborations.

  10. Environmental testing of CIS based modules

    Energy Technology Data Exchange (ETDEWEB)

    Willett, D.

    1995-11-01

    This report describes environmental testing of Siemen`s CIS modules. Charts and diagrams are presented on data concerning: temporary power loss of laminated mini-modules; the 50 thermal cycle test; the 10 humidity freeze cycle test; results after 1000 hours of exposure to damp heat; and interconnect test structures in damp heat testing. It is concluded that moisture ingress causes permanent increases in the series resistance of modules, and that improved packaging is needed for better high humidity reliability. Also, dry dark heat caused temporary power losses which were recovered in sunlight.

  11. Sunlight-induced photochemical decay of oxidants in natural waters: implications in ballast water treatment.

    Science.gov (United States)

    Cooper, William J; Jones, Adam C; Whitehead, Robert F; Zika, Rod G

    2007-05-15

    The transport and discharge of ship ballast water has been recognized as a major vector for the introduction of invasive species. Chemical oxidants, long used in drinking water and wastewater treatment, are alternative treatment methods for the control of invasive species currently being tested for use on ships. One concern when a ballasted vessel arrives in port is the adverse effects of residual oxidant in the treated water. The most common oxidants include chlorine (HOCl/OCl-), bromine (HOBr/OBr-), ozone (03), hydrogen peroxide (H2O2), chlorine dioxide (ClO2), and monochloramine (NH2Cl). The present study was undertaken to evaluate the sunlight-mediated photochemical decomposition of these oxidants. Sunlight photodecomposition was measured at various pH using either distilled water or oligotrophic Gulf Stream water for specific oxidants. For selected oxidants, quantum yields at specific wavelengths were obtained. An environmental photochemical model, GCSOLAR, also provided predictions of the fate (sunlight photolysis half-lives) of HOCI/OCl-, HOBr/OBr-, ClO2, and NH2Cl for two different seasons at latitude 40 degrees and in water with two different concentrations of chromophoric dissolved organic matter. These data are useful in assessing the environmental fate of ballast water treatment oxidants if they were to be discharged in port.

  12. [The effect of growth media on recovery of test microorganisms after exposure to saturated steam under pressure].

    Science.gov (United States)

    Krzywicka, H; Jakimiak, B; Zarzycka, E

    1996-01-01

    The aim of this study was to find out which growth media give the best condition for the development of test bacteria after exposure to saturated steam under pressure. The test organisms were strains of Bacillus subtilis NCTC 3610 and Bacillus stearothermophilus NCTC 8923. The test prepared from spore suspension were exposed to saturated steam under pressure 0.2 atn-B.subtilis, and 0.7 atn-B. stearothermophilus with various length of exposure /sublethal conditions/. After the exposure the tests were placed in growth media. The obtained results show that the compositions of the medium in which spore-forming bacteria are grown after the exposure under sublethal conditions to saturated steam under pressure affects the recovery of the test organism. The media with glucose, tryptose and L-alanine provided the best conditions for growth.

  13. Dysregulation of long noncoding RNAs in mouse testes and spermatozoa after exposure to cadmium.

    Science.gov (United States)

    Gao, Fengxin; Zhang, Peng; Zhang, Hongyan; Zhang, Yunhui; Zhang, Yunwen; Hao, Qingyun; Zhang, Xiaoning

    2017-02-26

    There is increasing evidence that cadmium (Cd) exposure can cause male subfertility and even complete infertility in mammals. Long noncoding (lnc) RNAs are critical for spermatogenesis, and their dysregulation might lead to male infertility. However, whether they are involved in Cd-induced subfertility is unknown. Here we found that intraperitoneal exposure to Cd in mice led to male subfertility indicated by reductions in testicular sperm production and motility, and by abnormal morphology. Testicular and sperm RNAs were used to investigate lncRNA expression profiles by strand-specific RNA sequencing at the transcriptome level to help determine any RNA-related mechanisms in Cd-induced subfertility. The Cd-treated testes and spermatozoa exhibited aberrant expression profiles for lncRNAs and mRNAs. Of the lncRNAs, there were 139 with upregulated expression and 174 with downregulated expression in testes; in contrast, 685 were upregulated and 375 were downregulated in spermatozoa. For mRNA expression, 214 were upregulated and 226 were downregulated in testes; 272 were upregulated and 111 were downregulated in spermatozoa. Gene ontology and pathway analyses showed that the functions of differentially expressed lncRNA targets and mRNAs were closely linked with many processes involved in spermatogenesis. Additionally, many newly identified lncRNAs showed inducible expression, suggesting that they might be good candidate markers for Cd-induced male reproductive toxicity. This study provides a preliminary database for further exploring lncRNA-related mechnisms in male infertility induced by Cd.

  14. Photosynthetic parameters and growth in seedlings of Bertholletia excelsa and Carapa guianensis in response to pre-acclimation to full sunlight and mild water stress

    National Research Council Canada - National Science Library

    Azevedo, Gracilene Fernandes da Costa

    2014-01-01

    .... I used six independent pre-acclimation treatments (0, 90 (11h15-12h45), 180 (10h30-13h30), 360 (09h00-15h00), 540 (07h30-16h30) and 720 min (06h00-18h00)) varying the time of exposure to full sunlight...

  15. Facility and Methods Developed for Simulated Space Vacuum Ultraviolet Exposure Testing of Polymer Films

    Science.gov (United States)

    Dever, Joyce A.; Pietromica, Anthony J.; Stueber, Thomas J.; Sechkar, Edward A.; Messer, Russell K.

    2002-01-01

    Vacuum ultraviolet (VUV) radiation of wavelengths between 115 and 200 nm produced by the Sun in the space environment can degrade polymer films, producing changes in their optical, mechanical, and chemical properties. These effects are particularly important for thin polymer films being considered for ultralightweight space structures, because, for most polymers, VUV radiation is absorbed in a thin surface layer. The NASA Glenn Research Center has developed facilities and methods for long-term ground testing of polymer films to evaluate space environmental VUV radiation effects. VUV exposure can also be used as part of combined or sequential simulated space environmental exposures to determine combined damaging effects with other aspects of the space environment, which include solar ultraviolet radiation, solar flare x-rays, electron and proton radiation, atomic oxygen (for low-Earth-orbit missions), and temperature effects. Because the wavelength sensitivity of VUV damage is not well known for most materials, Glenn's VUV facility uses a broad-spectrum deuterium lamp with a magnesium fluoride window that provides output between 115 and 200 nm. Deuterium lamps of this type were characterized by the National Institute of Standards and Technology and through measurements at Glenn. Spectral irradiance measurements show that from approximately 115 to 160 nm, deuterium lamp irradiance can be many times that of air mass zero solar irradiance, and as wavelength increases above approximately 160 nm, deuterium lamp irradiance decreases in comparison to the Sun. The facility is a cryopumped vacuum chamber that achieves a system pressure of approximately 5310(exp -6) torr. It contains four individual VUV-exposure compartments in vacuum, separated by water-cooled copper walls to minimize VUV radiation and any sample contamination cross interactions between compartments. Each VUV-exposure compartment contains a VUV deuterium lamp, a motor-controlled sample stage coupled with a

  16. Simulation tests to assess occupational exposure to airborne asbestos from asphalt-based roofing products.

    Science.gov (United States)

    Mowat, Fionna; Weidling, Ryan; Sheehan, Patrick

    2007-07-01

    This study sought to evaluate exposure from specific products to evaluate potential risk from roof repair activities. Five asbestos-containing fibered roof coatings and plastic cements, representing a broad range of these types of products, were tested in exposure simulations. These products were applied to representative roof substrates. Release of asbestos fibers during application and sanding of the product shortly thereafter (wet sanding) were tested initially. Other roof substrates were cured to simulate a product that had been on a rooftop for several months and then were tested to evaluate release of fibers during hand sanding and hand scraping activities. Additional tests were also conducted to evaluate asbestos release during product removal from tools and clothing. Two personal (n = 84) and background/clearance (n = 49) samples were collected during each 30-min test and analyzed for total fiber concentration [phase-contrast microscopy (PCM)] and for asbestos fiber count [transmission electron microscopy (TEM)]. PCM concentrations ranged from <0.005 to 0.032 fibers per cubic centimeter (f cc(-1)). Chrysotile fibers were detected in 28 of 84 personal samples collected. TEM concentrations ranged from <0.0021 to 0.056 f cc(-1). Calculated 8-h time-weighted averages (TWAs) ranged from 0.0003 to 0.002 f cc(-1) and were comparable to the background TWA concentration of 0.0002 f cc(-1) measured in this study. Based on these results, it is unlikely that roofers were exposed to airborne asbestos concentrations above the current or historical occupational guidelines during scraping and sanding of these products during roof repair.

  17. Immunological Testing Reveals Exposure to Malaria in the Hypoendemic Region of Iran.

    Science.gov (United States)

    Obeidi, Narges; Rajasekariah, G-Halli; Nabipour, Iraj; Amirinejad, Roya; Dogcio, Diane; Emami, Habib

    2014-01-01

    Background. South eastern parts of Iran remain endemic for malaria infection. There is some concern that malaria infection may spread into Bushehr, which is located in the south western part bordering the Persian Gulf and at the periphery of the declared endemic region Hormozgan province due to frequency of visitors from eastern endemic areas and from neighboring malaria endemic countries. We investigated malaria prevalence in Bushehr. Methods and Results. Attempts were made to identify malaria active infection in blood smears and malaria specific antibody and antigens in serum samples. Traditional blood smears prepared from 1955 blood specimens yielded no definitive malaria positive case by microscopic technique. A total of 270 (13.8%) serum samples were positive for malaria antibodies. Using specific ELISA kits, presence of histidine rich proteins and lactate dehydrogenase antigens were investigated in serum samples. No histidine rich proteins specific for P. falciparum were detected amongst 270 antibody positive samples. However, six samples representing 0.3% of total population, were found to be positive for plasmodium pan specific lactate dehydrogenase antigens. This suggested the possibility of low level exposure to malaria in Bushehr community. Conclusions. Out of a total of 1955 samples tested, 270 (13.8%) were positive for malaria antibodies and six (0.3%) of these were positive for plasmodium-specific lactate dehydrogenase antigen suggesting a low level exposure to malaria in a hypoendemic region based on immunological testing. Since none of the 270 antibody samples were positive for histidine rich protein antigens, there is scope for further testing of blood samples by molecular methods such as polymerase chain reactions to confirm the plasmodium species and provide information valuable for future investigations. Our testing strategy for hypoemdemic malaria can be used as a template for investing malaria in 32 eliminating countries for testing ongoing

  18. Photochemical transformation of graphene oxide in sunlight (journal)

    Science.gov (United States)

    Graphene oxide (GO) is a graphene derivative that is more easily manufactured in large scale and used to synthesize reduced graphene oxide (rGO) with properties analogous to graphene. In this study, we investigate the photochemical fate of GO under sunlight conditions. The resu...

  19. Electricity from Sunlight: The Future of Photovoltaics. Worldwatch Paper 52.

    Science.gov (United States)

    Flavin, Christopher

    Solar photovoltaic cells have been called the ultimate energy technology, environmentally benign and without moving parts, solar cells directly convert sunlight into electricity. Photovoltaic energy conversion is fundamentally different from all other forms of electricity generation. Without turbines, generators or other mechanical equipment, it…

  20. A routine quality assurance test for CT automatic exposure control systems.

    Science.gov (United States)

    Iball, Gareth R; Moore, Alexis C; Crawford, Elizabeth J

    2016-07-08

    The study purpose was to develop and validate a quality assurance test for CT automatic exposure control (AEC) systems based on a set of nested polymethylmethacrylate CTDI phantoms. The test phantom was created by offsetting the 16 cm head phantom within the 32 cm body annulus, thus creating a three part phantom. This was scanned at all acceptance, routine, and some nonroutine quality assurance visits over a period of 45 months, resulting in 115 separate AEC tests on scanners from four manufacturers. For each scan the longitudinal mA modulation pattern was generated and measurements of image noise were made in two annular regions of interest. The scanner displayed CTDIvol and DLP were also recorded. The impact of a range of AEC configurations on dose and image quality were assessed at acceptance testing. For systems that were tested more than once, the percentage of CTDIvol values exceeding 5%, 10%, and 15% deviation from baseline was 23.4%, 12.6%, and 8.1% respectively. Similarly, for the image noise data, deviations greater than 2%, 5%, and 10% from baseline were 26.5%, 5.9%, and 2%, respectively. The majority of CTDIvol and noise deviations greater than 15% and 5%, respectively, could be explained by incorrect phantom setup or protocol selection. Barring these results, CTDIvol deviations of greater than 15% from baseline were found in 0.9% of tests and noise deviations greater than 5% from baseline were found in 1% of tests. The phantom was shown to be sensitive to changes in AEC setup, including the use of 3D, longitudinal or rotational tube current modulation. This test methodology allows for continuing performance assessment of CT AEC systems, and we recommend that this test should become part of routine CT quality assurance programs. Tolerances of ± 15% for CTDIvol and ± 5% for image noise relative to baseline values should be used.

  1. Use of hair testing to determine methadone exposure in pediatric deaths.

    Science.gov (United States)

    Tournel, Gilles; Pollard, Jocelyn; Humbert, Luc; Wiart, Jean-François; Hédouin, Valéry; Allorge, Delphine

    2014-09-01

    A case of death attributed to methadone acute poisoning in an infant aged 11 months is reported. A sudden infant death syndrome (SIDS) was suspected, whereas a traumatic cause of death was excluded regarding autopsy findings. Specimens were submitted to a large toxicological analysis, which included ethanol measurement by HS-GC-FID, a targeted screening for drugs of abuse and various prescription drug classes followed by quantification using UPLC-MS/MS methods. Methadone and its metabolite (EDDP) were detected in all the tested fluids, as well as in hair, with a blood concentration of methadone considered as lethal for children (73 ng/mL). The cause of death was determined to be acute "methadone poisoning", and the manner of death was "accidental". A discussion of the case circumstances, the difficulties with the interpretation of toxicological findings in children (blood concentration and hair testing), and the origin of exposure are discussed.

  2. The genotoxic effects of DNA lesions induced by artificial UV-radiation and sunlight.

    Science.gov (United States)

    Schuch, André Passaglia; Menck, Carlos Frederico Martins

    2010-06-01

    Solar radiation sustains and affects all life forms on Earth. The increase in solar UV-radiation at environmental levels, due to depletion of the stratospheric ozone layer, highlights serious issues of social concern. This becomes still more dramatic in tropical and subtropical regions where radiation-intensity is still higher. Thus, there is the need to evaluate the harmful effects of solar UV-radiation on the DNA molecule as a basis for assessing the risks involved for human health, biological productivity and ecosystems. In order to evaluate the profile of DNA damage induced by this form of radiation and its genotoxic effects, plasmid DNA samples were exposed to artificial-UV lamps and directly to sunlight. The induction of cyclobutane pyrimidine dimer photoproducts (CPDs) and oxidative DNA damage in these molecules were evaluated by means of specific DNA repair enzymes. On the other hand, the biological effects of such lesions were determined through the analysis of the DNA inactivation rate and mutation frequency, after replication of the damaged pCMUT vector in an Escherichia coliMBL50 strain. The results indicated the induction of a significant number of CPDs after exposure to increasing doses of UVC, UVB, UVA radiation and sunlight. Interestingly, these photoproducts are those lesions that better correlate with plasmid inactivation as well as mutagenesis, and the oxidative DNA damages induced present very low correlation with these effects. The results indicated that DNA photoproducts play the main role in the induction of genotoxic effects by artificial UV-radiation sources and sunlight.

  3. International Test Program for Synergistic Atomic Oxygen and Vacuum Ultraviolet Radiation Exposure of Spacecraft Materials

    Science.gov (United States)

    Miller, Sharon K.

    2001-01-01

    The components and materials of spacecraft in low Earth orbit can degrade in thermal and optical performance through interaction with atomic oxygen and vacuum ultraviolet (VUV) radiation, which are predominant in low Earth orbit. Because of the importance of low Earth orbit durability and performance to manufacturers and users, an international test program for assessing the durability of spacecraft materials and components was initiated. Initial tests at the NASA Glenn Research Center consisted of exposure of samples representing a variety of thermal control paints, multilayer insulation materials, and Sun sensors that have been used in space. Materials donated from various international sources were tested alongside materials whose performance is well known, such as Teflon FEP, Kapton H, or Z-93-P white paint. The optical, thermal, or mass loss data generated during the tests were then provided to the participating material suppliers. Data were not published unless the participant donating the material consented to publication. The test program is intended to give spacecraft builders and users a better understanding of degradation processes and effects so that they can improve their predictions of spacecraft performance.

  4. Sunlight Modulates Fruit Metabolic Profile and Shapes the Spatial Pattern of Compound Accumulation within the Grape Cluster

    Science.gov (United States)

    Reshef, Noam; Walbaum, Natasha; Agam, Nurit; Fait, Aaron

    2017-01-01

    Vineyards are characterized by their large spatial variability of solar irradiance (SI) and temperature, known to effectively modulate grape metabolism. To explore the role of sunlight in shaping fruit composition and cluster uniformity, we studied the spatial pattern of incoming irradiance, fruit temperature and metabolic profile within individual grape clusters under three levels of sunlight exposure. The experiment was conducted in a vineyard of Cabernet Sauvignon cv. located in the Negev Highlands, Israel, where excess SI and midday temperatures are known to degrade grape quality. Filtering SI lowered the surface temperature of exposed fruits and increased the uniformity of irradiance and temperature in the cluster zone. SI affected the overall levels and patterns of accumulation of sugars, organic acids, amino acids and phenylpropanoids, across the grape cluster. Increased exposure to sunlight was associated with lower accumulation levels of malate, aspartate, and maleate but with higher levels of valine, leucine, and serine, in addition to the stress-related proline and GABA. Flavan-3-ols metabolites showed a negative response to SI, whereas flavonols were highly induced. The overall levels of anthocyanins decreased with increased sunlight exposure; however, a hierarchical cluster analysis revealed that the members of this family were grouped into three distinct accumulation patterns, with malvidin anthocyanins and cyanidin-glucoside showing contrasting trends. The flavonol-glucosides, quercetin and kaempferol, exhibited a logarithmic response to SI, leading to improved cluster uniformity under high-light conditions. Comparing the within-cluster variability of metabolite accumulation highlighted the stability of sugars, flavan-3-ols, and cinnamic acid metabolites to SI, in contrast to the plasticity of flavonols. A correlation-based network analysis revealed that extended exposure to SI modified metabolic coordination, increasing the number of negative

  5. Sunlight and the 5-year incidence of early age-related maculopathy: the beaver dam eye study.

    Science.gov (United States)

    Cruickshanks, K J; Klein, R; Klein, B E; Nondahl, D M

    2001-02-01

    To investigate the relation of sunlight exposure and indicators of sun sensitivity with the 5-year incidence of early age-related maculopathy (ARM). Longitudinal, population-based study. Participants (aged 43-86 years at baseline) in the Beaver Dam Eye Study were reexamined from 1993 to 1995, 5 years after the baseline examination. Questionnaire data about sunlight exposure and sun sensitivity were obtained at baseline. Additional information about earlier life patterns of exposure was ascertained at follow-up. Stereoscopic color fundus photographs were graded to determine the presence of ARM at the 5-year follow-up in eyes free from signs of early ARM at the baseline examination. Leisure time spent outdoors while persons were teenagers (aged 13-19 years) and in their 30s (aged 30-39 years) was significantly associated with the risk of early ARM (odds ratio, 2.09; 95% confidence interval, 1.19-3.65). There was a slight, but nonsignificant, protective effect associated with use of hats and sunglasses while persons were teenagers and in their 30s (odds ratio, 0.72; 95% confidence interval, 0.50-1.03). People with red or blond hair were slightly more likely to develop early ARM than people with darker hair (odds ratio, 1.33; 95% confidence interval, 0.97-1.83). There were no associations between estimated ambient UV-B exposure or markers of sun sensitivity and the incidence of early ARM. Exposure to sunlight may be associated with the development of early ARM.

  6. A rapid field test for sylvatic plague exposure in wild animals.

    Science.gov (United States)

    Abbott, Rachel C; Hudak, Robert; Mondesire, Roy; Baeten, Laurie A; Russell, Robin E; Rocke, Tonie E

    2014-04-01

    Plague surveillance is routinely conducted to predict future epizootics in wildlife and exposure risk for humans. The most common surveillance method for sylvatic plague is detection of antibodies to Yersinia pestis F1 capsular antigen in sentinel animals, such as coyotes (Canis latrans). Current serologic tests for Y. pestis, hemagglutination (HA) test and enzyme-linked immunosorbent assay (ELISA), are expensive and labor intensive. To address this need, we developed a complete lateral flow device for the detection of specific antibodies to Y. pestis F1 and V antigens. Our test detected anti-F1 and anti-V antibodies in serum and Nobuto filter paper samples from coyotes, and in serum samples from prairie dogs (Cynomys ludovicianus), lynx (Lynx canadensis), and black-footed ferrets (Mustela nigripes). Comparison of cassette results for anti-F1 and anti-V antibodies with results of ELISA or HA tests showed correlations ranging from 0.68 to 0.98. This device provides an affordable, user-friendly tool that may be useful in plague surveillance programs and as a research tool.

  7. Reading ability and print exposure: item response theory analysis of the author recognition test.

    Science.gov (United States)

    Moore, Mariah; Gordon, Peter C

    2015-12-01

    In the author recognition test (ART), participants are presented with a series of names and foils and are asked to indicate which ones they recognize as authors. The test is a strong predictor of reading skill, and this predictive ability is generally explained as occurring because author knowledge is likely acquired through reading or other forms of print exposure. In this large-scale study (1,012 college student participants), we used item response theory (IRT) to analyze item (author) characteristics in order to facilitate identification of the determinants of item difficulty, provide a basis for further test development, and optimize scoring of the ART. Factor analysis suggested a potential two-factor structure of the ART, differentiating between literary and popular authors. Effective and ineffective author names were identified so as to facilitate future revisions of the ART. Analyses showed that the ART is a highly significant predictor of the time spent encoding words, as measured using eyetracking during reading. The relationship between the ART and time spent reading provided a basis for implementing a higher penalty for selecting foils, rather than the standard method of ART scoring (names selected minus foils selected). The findings provide novel support for the view that the ART is a valid indicator of reading volume. Furthermore, they show that frequency data can be used to select items of appropriate difficulty, and that frequency data from corpora based on particular time periods and types of texts may allow adaptations of the test for different populations.

  8. A rapid field test for sylvatic plague exposure in wild animals

    Science.gov (United States)

    Abbott, Rachel C.; Hudak, Robert; Mondesire, Roy; Baeten, Laurie A.; Russell, Robin E.; Rocke, Tonie E.

    2014-01-01

    Plague surveillance is routinely conducted to predict future epizootics in wildlife and exposure risk for humans. The most common surveillance method for sylvatic plague is detection of antibodies to Yersinia pestis F1 capsular antigen in sentinel animals, such as coyotes (Canis latrans). Current serologic tests for Y. pestis, hemagglutination (HA) test and enzyme-linked immunosorbent assay (ELISA), are expensive and labor intensive. To address this need, we developed a complete lateral flow device for the detection of specific antibodies to Y. pestis F1 and V antigens. Our test detected anti-F1 and anti-V antibodies in serum and Nobuto filter paper samples from coyotes, and in serum samples from prairie dogs (Cynomys ludovicianus), lynx (Lynx canadensis), and black-footed ferrets (Mustela nigripes). Comparison of cassette results for anti-F1 and anti-V antibodies with results of ELISA or HA tests showed correlations ranging from 0.68 to 0.98. This device provides an affordable, user-friendly tool that may be useful in plague surveillance programs and as a research tool.

  9. Knowledge of vitamin D and perceptions and attitudes toward sunlight among Chinese middle-aged and elderly women: a population survey in Hong Kong

    Directory of Open Access Journals (Sweden)

    Lee Ka-Kui

    2006-09-01

    Full Text Available Abstract Background Physical and biological risk factors for vitamin D inadequacy are known; however, cultural- and population-specific behaviours and attitudes that influence these risk factors, particularly among Asian people, are less well documented. To understand more about prevailing attitudes and behaviour toward sunlight and knowledge of vitamin D among a population at greater risk of impaired vitamin D status, poor bone health and osteoporosis, we conducted a telephone interview survey of 547 middle-aged and elderly Chinese women living in Hong Kong. Methods All telephone interviews were conducted using the Computer Assisted Telephone Technique and target respondents were selected by random sampling. Interviews were conducted in Cantonese and eighteen main questions were asked pertaining to personal characteristics, perceptions, attitudes and behaviour toward sunlight, and knowledge about vitamin D. Results The survey results showed that 62.3% (n = 341 did not like going in the sun and 66.7% of respondents spent an average of 6–10 hours indoors, between 6:30 am and 7:00 pm, during weekdays. However, 58% of people thought that they had enough exposure to sunlight. The majority had heard of vitamin D, but knowledge about the role and sources of vitamin D was low. Among those who knew that sunlight was a source of vitamin D, the majority spent less than 1 h in the sun in the past week (76.4% vs 23.6%, 1 h in the sun in the past week, chi-square p Conclusion The survey revealed considerable ignorance and confusion about the role of sunlight in vitamin D production, and the function and sources of vitamin D. Attitudes and behaviour toward sunlight were largely negative and many took measures to avoid sunlight, particularly among younger (middle-aged women who had good awareness of vitamin D.

  10. Exposure Assessment of a High-energy Tensile Test With Large Carbon Fiber Reinforced Polymer Cables.

    Science.gov (United States)

    Schlagenhauf, Lukas; Kuo, Yu-Ying; Michel, Silvain; Terrasi, Giovanni; Wang, Jing

    2015-01-01

    This study investigated the particle and fiber release from two carbon fiber reinforced polymer cables that underwent high-energy tensile tests until rupture. The failing event was the source of a large amount of dust whereof a part was suspected to be containing possibly respirable fibers that could cause adverse health effects. The released fibers were suspected to migrate through small openings to the experiment control room and also to an adjacent machine hall where workers were active. To investigate the fiber release and exposure risk of the affected workers, the generated particles were measured with aerosol devices to obtain the particle size and particle concentrations. Furthermore, particles were collected on filter samples to investigate the particle shape and the fiber concentration. Three situations were monitored for the control room and the machine hall: the background concentrations, the impact of the cable failure, and the venting of the exposed rooms afterward. The results showed four important findings: The cable failure caused the release of respirable fibers with diameters below 3 μm and an average length of 13.9 μm; the released particles did migrate to the control room and to the machine hall; the measured peak fiber concentration of 0.76 fibers/cm(3) and the overall fiber concentration of 0.07 fibers/cm(3) in the control room were below the Permissible Exposure Limit (PEL) for fibers without indication of carcinogenicity; and the venting of the rooms was fast and effective. Even though respirable fibers were released, the low fiber concentration and effective venting indicated that the suspected health risks from the experiment on the affected workers was low. However, the effect of long-term exposure is not known therefore additional control measures are recommended.

  11. Development, validation and testing of a skin sampling method for assessment of metal exposure.

    Science.gov (United States)

    Erfani, Behnaz; Midander, Klara; Lidén, Carola; Julander, Anneli

    2017-07-01

    Nickel, cobalt and chromium are frequent skin sensitizers. Skin exposure results in eczema in sensitized individuals, the risk being related to the skin dose. To develop a self-sampling method for quantification of skin exposure to metals, to validate the method, and to assess its feasibility. Defined metal doses (0.01-5 µg) were applied to the fingers of 5 participants. Skin areas (2 cm(2) ) were sampled with 1% HNO3 , either as 0.1 ml on a swab, or as 0.5 ml on a wipe. Furthermore, 17 participants performed self-sampling by swab after 2 h of leisure activity. Samples were extracted in 1% HNO3 and analysed by inductively coupled plasma mass spectrometry. The sampling efficiency by swab was 46%, as compared with 93% for acid wipe sampling, for all tested doses. Most metal from the skin dose was detected in the first swab (33-43%). Despite lower sampling efficiency by swab, skin doses of metals following 2 h of leisure activity without hand washing were quantified in all participants, and ranged from 0.0016 to 0.15 µg/cm(2) , from 0.00014 to -0.0020 µg/cm(2) and from 0.00048 to -0.027 µg/cm(2) for nickel, cobalt, and chromium, respectively. The results indicate a future potential of skin sampling by swab to detect and monitor metals on skin by self-sampling. This will contribute to better knowledge of metal skin exposure among dermatitis patients, workers, and the general population. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. A test cassette for x-ray-exposure experiments at the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, K. B.; Celeste, J.; Rekow, V.; Bopp, D. R.; May, M. J.; Fisher, J. H.; Horton, R.; Newlander, C. D.; Jenkins, P.; Trautz, K.

    2010-07-01

    We present the design and operation of a test cassette for exposure of samples to radiation environments at the National Ignition Facility. The cassette provides options for square and round samples and exposure areas; the cassette provides for multiple levels of filtration on a single sample, which allows dynamic range in experiments. The samples had normal lines of sight to the x-ray source in order to have uniform x-ray illumination. The incident x-radiation onto the samples was determined by the choice of filter thicknesses and materials. The samples were held at precise locations, accurate to within a few hundred microns, in the target chamber in order to have a known fluence incident. In the cassette, the samples were held in place in such a way that a minimal “line contact” allows them to have the maximal mechanical response to the x-ray load. We present postshot images of the debris found on films used for filters, and pre- and postexposure specimens.

  13. Real time outdoor exposure testing of solar cell modules and component materials

    Science.gov (United States)

    Anagnostou, E.; Forestieri, A. F.

    1977-01-01

    Plastic samples, solar cell modules, and sub-modules were exposed at test sites in Florida, Arizona, Puerto Rico, and Cleveland, Ohio, in order to determine materials suitable for use in solar cell modules with a proposed 20-year lifetime. Various environments were encountered including subtropical, subtropical with a sea air atmosphere, desert, rain forest, normal urban, and urban-polluted. The samples were exposed for periods up to six months. Materials found not suitable were polyurethane, polyester, Kapton, Mylar, and UV-stabilized Lexan. Suitable materials were acrylic, FEP-A, and glass. The results of exposure of polyvinylidene fluoride were dependent on the specific formulation, but several types appear suitable. RTV silicone rubber (clear) appears to pick up and hold dirt both as a free film and as a potting medium for modules. The results indicate that dirt accumulation and cleanability are important factors in the selection of solar cell module covers and encapsulants.

  14. Corrosion of metals in wood : comparing the results of a rapid test method with long-term exposure tests across six wood treatments

    Science.gov (United States)

    Samuel L. Zelinka; Donald S. Stone

    2011-01-01

    This paper compares two methods of measuring the corrosion of steel and galvanized steel in wood: a long-term exposure test in solid wood and a rapid test method where fasteners are electrochemically polarized in extracts of wood treated with six different treatments. For traditional wood preservatives, the electrochemical extract method correlates with solid wood...

  15. Concentration-response analysis of differential gene expression in the zebrafish embryotoxicity test following flusilazole exposure.

    Science.gov (United States)

    Hermsen, Sanne A B; Pronk, Tessa E; van den Brandhof, Evert-Jan; van der Ven, Leo T M; Piersma, Aldert H

    2012-05-01

    The zebrafish embryotoxicity test (ZET) is considered a promising alternative model in predictive toxicology. Currently, morphological assessment of the embryo is the main readout for this assay. However, implementation of transcriptomics may help to detect more subtle effects, which may increase the sensitivity and predictability of the test. In this study, we tested a concentration response of flusilazole in the ZET. After exposure for 24 h postfertilization, microarray analysis revealed a number of processes to be regulated in a concentration-dependent way. We identified development related processes, retinol metabolism and transcription, as well as processes corresponding to the antifungal mechanism of action, steroid biosynthesis, and fatty acid metabolism, to be differentially regulated. Retinol metabolism and transcription were already significantly altered at concentrations that were not inducing morphological effects. Differential expression of genes related to steroid biosynthesis and fatty acid metabolism showed a concentration response similar to morphological response. An increase in concentration was also positively associated with an increase in magnitude of expression for individual genes within functional processes. Our study shows that transcriptomics analysis in the ZET is a more sensitive readout of compound-induced effects than morphological assessment. However, the interpretation of differential gene expression in terms of predicting morphological effects is not straightforward and requires further study.

  16. Novel materials and devices for sunlight concentrating systems

    Science.gov (United States)

    Hovel, H. J.

    1980-09-01

    An economic analysis of photovoltaic conversion under concentrated sunlight has been performed which demonstrates that solar cell efficiency, concentrator efficiency, and concentrator cost are the most important parameters in a concentrating photovoltaic system; solar cell cost is only of secondary importance. Six novel structures are described, including modified conventional Si cells Ga(1-x)Al(x)As/GaAs, interdigitated cells, vertical and horizontal multijunction cells and 'multicolor' devices.

  17. Using Alternative Approaches to Prioritize Testing for the Universe of Chemicals with Potential for Human Exposure (WC9)

    Science.gov (United States)

    One use of alternative methods is to target animal use at only those chemicals and tests that are absolutely necessary. We discuss prioritization of testing based on high-throughput screening assays (HTS), QSAR modeling, high-throughput toxicokinetics (HTTK), and exposure modelin...

  18. Terrestrial photovoltaic power systems with sunlight concentration. Annual progress report, January 1, 1975--December 31, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Backus, C.E.

    1976-01-31

    This annual report is for the second year of a program to investigate the characteristics of the components and the total system using sunlight concentrated onto solar cells. The second year was primarily to experimentally investigate the conclusions of the first year of analytical studies. Cells have been fabricated that are designed for different intensities. Typically the efficiency of a cell will increase from its 11 percent at AM1 peak to efficiency at the designed concentration level and return to its initial efficiency at about 3 times its designed concentration level. The developed cells have been tested under high intensity simulators and in concentrated sunlight and have shown to have the predicted response. The experimental testing of passive cooling limitations for cooling cells with just finned arrangements in the back of the cell has been completed in the controlled environment of a wind tunnel. These experiments have confirmed the heat transfer coefficients that had been used in the analytical studies. Testing was done to collect heat transfer coefficients for actual wind conditions and these data show good agreement with the controlled wind tunnel data. Four photovoltaic/concentrator system experiments have been started with CR of about 3, 10, 25, and 100. System analysis has indicated that photovoltaic concentration systems may be attractive in low solar irradiation areas such as Cleveland.

  19. Recovery of terrestrial plants in vegetative vigor and seedling emergence tests from exposure to atrazine.

    Science.gov (United States)

    Brain, Richard A; Hoberg, James

    2016-05-01

    Ten species of terrestrial plants, including 6 dicotyledonous and 4 monocotyledonous species, were exposed to a direct overspray of atrazine according to US Environmental Protection Agency seedling emergence and vegetative vigor study guidelines and subsequently evaluated for potential recovery. For each species, no-observed-effect rate (NOER), 10% effect rate, 25% effect rate, and 50% effect rate values were calculated (where possible) for a variety of guideline-required endpoints (but focusing on growth rate) for both the standard experimental phase and a recovery phase; and the rates subsequently were compared. For the seedling emergence study, the standard experimental (designated test 1) and recovery (designated test 2) phases encompassed days 0 to 14 and days 14 to 28, respectively. Similarly, for the vegetative vigor study, test 1 and test 2 encompassed days 0 to 21 and days 21 to 42, respectively. Plants were exposed to atrazine at nominal application rates ranging from 1.1 g active ingredient (a.i.)/ha (0.0010 lb a.i./A) to 28,000 g a.i./ha (25 lb a.i./A), depending on the species; the 28,000 g a.i./ha rate is greater than 12 times the maximum application rate of 2250 g a.i./ha (2 lb a.i./A) registered on corn. For seedling emergence, only 2 of 10 species tested, cabbage and tomato, provided clear rate responses in the initial 14 d of exposure (test 1). Based on a comparison of x% effect rate (ERx) and NOER values for growth rates of shoot length and shoot dry weight for days 0 to 14 relative to days 14 to 28, recovery was apparent for cabbage shoot length growth rate and tomato shoot length and shoot dry weight growth rates. Test application rates selected for the remaining 8 species showed either a weak response that did not allow a clear assessment of recovery or no response at all. For the vegetative vigor study, 9 of the 10 species tested provided clear rate responses in test 1 (days 0-21); corn did not demonstrate any herbicidal response up

  20. Testing a cumulative and aggregate exposure model using biomonitoring studies and dietary records for Italian vineyard spray operators.

    Science.gov (United States)

    Kennedy, Marc C; Glass, C Richard; Fustinoni, Silvia; Moretto, Angelo; Mandic-Rajcevic, Stefan; Riso, Patrizia; Turrini, Aida; van der Voet, Hilko; Hetmanski, Michel T; Fussell, Richard J; van Klaveren, Jacob D

    2015-05-01

    The need for improved tools to estimate the cumulative and aggregate exposure to compounds such as plant protection products (PPPs) is recognised in the EU Regulation 1107/2009. A new model has been developed to estimate the exposure within a population to single compounds or compounds within a Cumulative Action Group, considering dietary and non-dietary sources and multiple exposure routes. To test the model a field study was carried out in Italy with operators applying tebuconazole fungicides, with measurements of dermal exposure collected. Whole urine samples were collected and analysed to provide values for the absorbed dose of tebuconazole, with duplicate diet samples collected and analysed as a measure of dietary exposures. The model provided predicted values of exposure for combined dietary and non-dietary routes of exposures which were compared to the measured absorbed dose values based on urinary analysis. The model outputs provided mean daily exposure values of 1.77 (± 1.96) µg a.s./kg BW which are comparable to measured mean values from the biomonitoring field study of 1.73 (± 1.31) µg a.s./kg BW. To supplement the limited measurement data available, comparisons against other models were also made and found to be comparable.

  1. Testing exposure of a jet engine to a dilute volcanic-ash cloud

    Science.gov (United States)

    Guffanti, M.; Mastin, L. G.; Schneider, D. J.; Holliday, C. R.; Murray, J. J.

    2013-12-01

    An experiment to test the effects of volcanic-ash ingestion by a jet engine is being planned for 2014 by a consortium of U.S. Government agencies and engine manufacturers, under the auspices of NASA's Vehicle Integrated Propulsion Research Program. The experiment, using a 757-type engine, will be an on-ground, on-wing test carried out at Edwards Air Force Base, California. The experiment will involve the use of advanced jet-engine sensor technology for detecting and diagnosing engine health. A primary test objective is to determine the effect on the engine of many hours of exposure to ash concentrations (1 and 10 mg/cu m) representative of ash clouds many 100's to >1000 km from a volcanic source, an aviation environment of great interest since the 2010 Eyjafjallajökull, Iceland, eruption. A natural volcanic ash will be used; candidate sources are being evaluated. Data from previous ash/aircraft encounters, as well as published airborne measurements of the Eyjafjallajökull ash cloud, suggest the ash used should be composed primarily of glassy particles of andesitic to rhyolitic composition (SiO2 of 57-77%), with some mineral crystals, and a few tens of microns in size. Collected ash will be commercially processed less than 63 microns in size with the expectation that the ash particles will be further pulverized to smaller sizes in the engine during the test. For a nominally planned 80 hour test at multiple ash-concentration levels, the test will require roughly 500 kg of processed (appropriately sized) ash to be introduced into the engine core. Although volcanic ash clouds commonly contain volcanic gases such as sulfur dioxide, testing will not include volcanic gas or aerosol interactions as these present complex processes beyond the scope of the planned experiment. The viscous behavior of ash particles in the engine is a key issue in the experiment. The small glassy ash particles are expected to soften in the engine's hot combustion chamber, then stick to cooler

  2. Microcapsule-based self-healing anticorrosive coatings: Capsule size, coating formulation, and exposure testing

    DEFF Research Database (Denmark)

    Nesterova, Tatyana; Dam-Johansen, Kim; Pedersen, Lars Thorslund

    2012-01-01

    Self-healing coatings is a rapidly growing research area, where focus has mainly been on development of new approaches to the mechanism of self-healing. However, there is a growing need for investigation of practical issues related to formulation, application, and testing of true self-healing coa......Self-healing coatings is a rapidly growing research area, where focus has mainly been on development of new approaches to the mechanism of self-healing. However, there is a growing need for investigation of practical issues related to formulation, application, and testing of true self......-healing coatings. In this work, ways of reducing the size of poly(urea–formaldehyde) microcapsules, filled with linseed oil and intended for a microcapsule-based self-healing anticorrosive coating (above water exposure), are explored. The influence of microcapsules on epoxy coating performance is also studied...... a decrease in microcapsule size but were accompanied by excessive formation of nanoparticles. Thus, isolation of too large microcapsules has been performed by filtration utilizing a novel low-energy fluoropolymer-coated steel sieve. An estimation of the critical pigment (microcapsule) volume concentration...

  3. Passive dosing: an approach to control mutagen exposure in the Ames fluctuation test.

    Science.gov (United States)

    Bougeard, Cynthia; Gallampois, Christine; Brack, Werner

    2011-04-01

    One of the major challenges for mutagenicity assessment of environmental samples and individual compounds for example in the Ames fluctuation test (AFT) is the establishment and control of a well defined exposure concentration. Thus, a combination of passive dosing with silicone O-rings (SRs) together with an analytical confirmation of the freely dissolved concentration (FDC) is presented. FDCs are often determined with a combination of solid phase micro-extraction (SPME) with gas chromatography (GC). For compounds with poor performance in GC, a high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis of bi-distilled water dosed with identically loaded SRs is suggested to avoid interference of the bacterial culture. The approach was tested for six amino-, nitro-, and keto-substituted polycyclic aromatic compounds with a logK(OW) range of 2.5-5.1 without metabolic activation. The method provided reliable concentration-effect relationships and freely dissolved 50% effect concentrations (DEC(50)) 3-33 times lower than nominal effect concentrations (NEC(50)) derived in parallel solvent-dosed AFT. Partition coefficients and NEC(50)/DEC(50) ratios were well correlated with lipophilicity.

  4. Performance Testing of Lidar Components Subjected to Space Exposure in Space via MISSE 7 Mission

    Science.gov (United States)

    Prasad, Narasimha S.

    2012-01-01

    .The objective of the Materials International Space Station Experiment (MISSE) is to study the performance of novel materials when subjected to the synergistic effects of the harsh space environment for several months. MISSE missions provide an opportunity for developing space qualifiable materials. Several laser and lidar components were sent by NASA Langley Research Center (LaRC) as a part of the MISSE 7 mission. The MISSE 7 module was transported to the international space station (ISS) via STS 129 mission that was launched on Nov 16, 2009. Later, the MISSE 7 module was brought back to the earth via the STS 134 that landed on June 1, 2011. The MISSE 7 module that was subjected to exposure in space environment for more than one and a half year included fiber laser, solid-state laser gain materials, detectors, and semiconductor laser diode. Performance testing of these components is now progressing. In this paper, the current progress on post-flight performance testing of a high-speed photodetector and a balanced receiver is discussed. Preliminary findings show that detector characteristics did not undergo any significant degradation.

  5. Performance testing of lidar components subjected to exposure in space via MISSE 7 mission

    Science.gov (United States)

    Prasad, Narasimha S.

    2012-10-01

    The objective of the Materials International Space Station Experiment (MISSE) is to study the performance of novel materials when subjected to the synergistic effects of the harsh space environment for several months. MISSE missions provide an opportunity for developing space qualifiable materials. Several laser and lidar components were sent by NASA Langley Research Center (LaRC) as a part of the MISSE 7 mission. The MISSE 7 module was transported to the international space station (ISS) via STS 129 mission that was launched on Nov 16, 2009. Later, the MISSE 7 module was brought back to the earth via the STS 134 that landed on June 1, 2011. The MISSE 7 module that was subjected to exposure in space environment for more than one and a half year included fiber laser, solid-state laser gain materials, detectors, and semiconductor laser diode. Performance testing of these components is now progressing. In this paper, the current progress on post-flight performance testing of a high-speed photodetector and a balanced receiver is discussed. Preliminary findings show that detector characteristics did not undergo any significant degradation.

  6. 3D Case Studies of Monitoring Dynamic Structural Tests using Long Exposure Imagery

    Science.gov (United States)

    McCarthy, D. M. J.; Chandler, J. H.; Palmeri, A.

    2014-06-01

    Structural health monitoring uses non-destructive testing programmes to detect long-term degradation phenomena in civil engineering structures. Structural testing may also be carried out to assess a structure's integrity following a potentially damaging event. Such investigations are increasingly carried out with vibration techniques, in which the structural response to artificial or natural excitations is recorded and analysed from a number of monitoring locations. Photogrammetry is of particular interest here since a very high number of monitoring locations can be measured using just a few images. To achieve the necessary imaging frequency to capture the vibration, it has been necessary to reduce the image resolution at the cost of spatial measurement accuracy. Even specialist sensors are limited by a compromise between sensor resolution and imaging frequency. To alleviate this compromise, a different approach has been developed and is described in this paper. Instead of using high-speed imaging to capture the instantaneous position at each epoch, long-exposure images are instead used, in which the localised image of the object becomes blurred. The approach has been extended to create 3D displacement vectors for each target point via multiple camera locations, which allows the simultaneous detection of transverse and torsional mode shapes. The proposed approach is frequency invariant allowing monitoring of higher modal frequencies irrespective of a sampling frequency. Since there is no requirement for imaging frequency, a higher image resolution is possible for the most accurate spatial measurement. The results of a small scale laboratory test using off-the-shelf consumer cameras are demonstrated. A larger experiment also demonstrates the scalability of the approach.

  7. A novel system for embryo-larval toxicity testing of pelagic fish: Applications for impact assessment of Deepwater Horizon crude oil.

    Science.gov (United States)

    Stieglitz, John D; Mager, Edward M; Hoenig, Ronald H; Alloy, Matthew; Esbaugh, Andrew J; Bodinier, Charlotte; Benetti, Daniel D; Roberts, Aaron P; Grosell, Martin

    2016-11-01

    Key differences in the developmental process of pelagic fish embryos, in comparison to embryos of standard test fish species, present challenges to obtaining sufficient control survival needed to successfully perform traditional toxicity testing bioassays. Many of these challenges relate to the change in buoyancy, from positive to negative, of pelagic fish embryos that occurs just prior to hatch. A novel exposure system, the pelagic embryo-larval exposure chamber (PELEC), has been developed to conduct successful bioassays on the early life stages (ELSs; embryos/larvae) of pelagic fish. Using this unique recirculating upwelling system, it was possible to significantly improve control survival in pelagic fish ELS bioassays compared to commonly used static exposure methods. Results demonstrate that control performance of mahi-mahi (Coryphaena hippurus) embryos in the PELEC system, measured as percent survival after 96-hrs, significantly outperformed agitated static exposure and static exposure systems. Similar significant improvements in 72-hr control survival were obtained with yellowfin tuna (Thunnus albacares). The PELEC system was subsequently used to test the effects of photo-induced toxicity of crude oil to mahi-mahi ELSs over the course of 96-hrs. Results indicate a greater than 9-fold increase in toxicity of Deepwater Horizon (DWH) crude oil during co-exposure to ambient sunlight compared to filtered ambient sunlight, revealing the importance of including natural sunlight in 96-hr DWH crude oil bioassays as well as the PELEC system's potential application in ecotoxicological assessments.

  8. Lead exposure and the 2010 achievement test scores of children in New York counties

    Directory of Open Access Journals (Sweden)

    Strayhorn Jillian C

    2012-01-01

    Full Text Available Abstract Background Lead is toxic to cognitive and behavioral functioning in children even at levels well below those producing physical symptoms. Continuing efforts in the U.S. since about the 1970s to reduce lead exposure in children have dramatically reduced the incidence of elevated blood lead levels (with elevated levels defined by the current U.S. Centers for Disease Control threshold of 10 μg/dl. The current study examines how much lead toxicity continues to impair the academic achievement of children of New York State, using 2010 test data. Methods This study relies on three sets of data published for the 57 New York counties outside New York City: school achievement data from the New York State Department of Education, data on incidence of elevated blood lead levels from the New York State Department of Health, and data on income from the U.S. Census Bureau. We studied third grade and eighth grade test scores in English Language Arts and mathematics. Using the county as the unit of analysis, we computed bivariate correlations and regression coefficients, with percent of children achieving at the lowest reported level as the dependent variable and the percent of preschoolers in the county with elevated blood lead levels as the independent variable. Then we repeated those analyses using partial correlations to control for possible confounding effects of family income, and using multiple regressions with income included. Results The bivariate correlations between incidence of elevated lead and number of children in the lowest achievement group ranged between 0.38 and 0.47. The partial correlations ranged from 0.29 to 0.40. The regression coefficients, both bivariate and partial (both estimating the increase in percent of children in the lowest achievement group for every percent increase in the children with elevated blood lead levels, ranged from 0.52 to 1.31. All regression coefficients, when rounded to the nearest integer, were

  9. Efficacy of sunlight-activatable porphyrin formulates on larvae of Anopheles gambiae M and S molecular forms and An. arabiensis: a potential novel biolarvicide for integrated malaria vector control.

    Science.gov (United States)

    Fabris, Clara; Ouédraogo, Robert Kossivi; Coppellotti, Olimpia; Dabiré, Roch K; Diabaté, Abdoulaye; Di Martino, Piera; Guidolin, Laura; Jori, Giulio; Lucantoni, Leonardo; Lupidi, Giulio; Martena, Valentina; Sawadogo, Simon P; Soncin, Marina; Habluetzel, Annette

    2012-09-01

    Biolarvicides, such as microbial formulations based on Bacillus thuringiensis and B. sphaericus, have been found to be highly effective against mosquito larvae and are currently employed as eco-friendly alternatives to synthetic chemical insecticides for vector control. Recently, a porphyrin of natural origin has been suggested as a sunlight-activatable larvicide against the dengue vector Aedes aegypti. In order to validate the approach for the control of the malaria vector, we tested the photo-larvicidal activity of a novel porphyrin, namely meso-tri(N-methyl-pyridyl), mono(N-dodecyl-pyridyl)porphine, C12, associated with two specifically selected carriers, against Anopheles gambiae s.s. and An. arabiensis larvae, both laboratory reared and collected from malaria endemic sites in Burkina Faso. Both C12-porphyrin formulates, when administered to larvae at a 50μM porphyrin dose, were accumulated in the alimentary canal. Subsequent exposure of the porphyrin-loaded larvae to sunlight for short times (0.5-3h) led to a complete mortality. The high efficacy exhibited by a "foodstuff" porphyrin formulate also in the presence of typical larval food particles opens promising perspectives for the development of an effective photocidal larvicide.

  10. Exposure to sun radiation as a risk factor for the occurrence of basal cell carcinoma in the Montenegrian population

    Directory of Open Access Journals (Sweden)

    Maksimović Nataša

    2006-01-01

    Full Text Available Backgound/aim: Basal cell carcinoma (BCC is the most frequent form of carcinomas in the whites. Among the environmental factors, the most important risk factor for its occurrence is the exposure to sun radiation. The aim of this study was to assess the role of the sun radiation in the development of basal cell carcinoma BCC in the Montenegrian population. Methods. A case-control study was conducted in a period from 2002-2003. The study group included 100 histopatologically confirmed cases with BCC, while the control group included 100 patients from the same population, who did not present skin cancer and who were individually matched with the cases from the study group by sex and age (± 5 years. All the participants were interviewed using an epidemiological questionnaire. For statistical analysis, the χ2 test and univariate logistic regression analysis were used. Results. The risk for development of BCC was increased in the persons: that always had burns with no tan during the exposure to sunlight (OR = 1.75; 95% CI = 1.20-2.55; p = 0.003; that developed sunburns after two hours of the exposure to sunlight (OR = 3.72; 95% CI = 2.39-5.79; p < 0.001 that kept light tan or remained without changes in childhood and adolescence after the repeated exposures to sunlight (OR = 2.92; 95% CI = 1.89-4.52; p < 0.001 that often had severe and painful sunburns (OR = 4.48; 95% CI = 2.74-7.33; p < 0.001. Conclusion. Our study confirmed the significance of sunlight exposure for the development of BCC.

  11. Changes in background impair fluency-triggered positive affect: a cross-cultural test using a mere-exposure paradigm.

    Science.gov (United States)

    Ishii, Keiko

    2011-04-01

    This study examined whether repeated exposure would enhance positive evaluations when only a part of a stimulus (e.g., the central object) was identical to a previously presented stimulus. Japanese and American participants were exposed to photographs of animals with scenery, then asked their preferences for each of four types of photographs of animals (photographs of animals with the original scenery, photographs of animals without scenery, photographs of animals with novel scenery, and photographs of animals not depicted previously). Finally, their recognition of the animals presented in the exposure phase was tested. Members of both groups showed the mere-exposure effect for the first two types of stimuli, irrespective of stimulus recognition accuracy, whereas this effect was not observed for animals presented with novel scenery. This suggests that changes in background impair positive affect as a result of repeated exposure.

  12. In vitro toxicity testing of cigarette smoke based on the air-liquid interface exposure: A review.

    Science.gov (United States)

    Li, Xiang

    2016-10-01

    Cigarette smoke is a complex aerosol comprising particulate phase and gaseous vapour phase. The air-liquid interface exposure provides a possible technical means to implement whole smoke exposure for the assessment of tobacco products. In this review, the research progress in the in vitro toxicity testing of cigarette smoke based on the air-liquid interface exposure is summarized. The contents presented involve mainly cytotoxicity, genotoxicity, oxidative stress, inflammation, systems toxicology, 3D culture and cigarette smoke dosimetry related to cigarette smoke, as well as the assessment of electronic cigarette aerosol. Prospect of the application of the air-liquid interface exposure method in assessing the biological effects of tobacco smoke is discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Exploring the linkage between exposure to mass media and HIV testing among married women and men in Ghana.

    Science.gov (United States)

    Sano, Yujiro; Sedziafa, Alice P; Amoyaw, Jonathan A; Boateng, Godfred O; Kuuire, Vincent Z; Boamah, Sheila; Kwon, Eugena

    2016-01-01

    Although HIV testing is critical to the treatment and prevention of HIV/AIDS, utilization rate of HIV testing services among married women and men remains low in Ghana. Mass media, as a tool to increase overall HIV testing turnouts, has been considered one of the important strategies in promoting and enhancing behavioural changes related to HIV/AIDS prevention. Using the 2014 Ghana Demographic and Health Survey, the current study examines the relationship between levels of exposure to print media, radio, and television and the uptake of HIV testing among married women and men in Ghana. Results show that HIV testing is more prevalent among married women than their male counterparts. We also find that higher levels of exposure to radio is associated with HIV testing among women, while higher levels of exposure to print media and television are associated with HIV testing among men. Implications of these findings are discussed for Ghana's HIV/AIDS strategic framework, which aims to expanding efforts at dealing with the HIV/AIDS epidemic. Specifically, it is important for health educators and programme planners to deliver HIV-related messages through television, radio, and print media to increase the uptake of HIV testing particularly among married women and men in Ghana.

  14. Numerical compliance testing of human exposure to electromagnetic radiation from smart-watches

    Science.gov (United States)

    Hong, Seon-Eui; Lee, Ae-Kyoung; Kwon, Jong-Hwa; Pack, Jeong-Ki

    2016-10-01

    In this study, we investigated the electromagnetic dosimetry for smart-watches. At present, the standard for compliance testing of body-mounted and handheld devices specifies the use of a flat phantom to provide conservative estimates of the peak spatial-averaged specific absorption rate (SAR). This means that the estimated SAR using a flat phantom should be higher than the SAR in the exposure part of an anatomical human-body model. To verify this, we numerically calculated the SAR for a flat phantom and compared it with the numerical calculation of the SAR for four anatomical human-body models of different ages. The numerical analysis was performed using the finite difference time domain method (FDTD). The smart-watch models were used in the three antennas: the shorted planar inverted-F antenna (PIFA), loop antenna, and monopole antenna. Numerical smart-watch models were implemented for cellular commutation and wireless local-area network operation at 835, 1850, and 2450 MHz. The peak spatial-averaged SARs of the smart-watch models are calculated for the flat phantom and anatomical human-body model for the wrist-worn and next to mouth positions. The results show that the flat phantom does not provide a consistent conservative SAR estimate. We concluded that the difference in the SAR results between an anatomical human-body model and a flat phantom can be attributed to the different phantom shapes and tissue structures.

  15. Violent media exposure, aggression and CU traits in adolescence: Testing the selection and socialization hypotheses.

    Science.gov (United States)

    Rydell, Ann-Margret

    2016-10-01

    We investigated the role of exposure to violent action for later aggression and for later callous-unemotional traits in a sample of Swedish adolescents (N = 77-85), testing the selection and socialization hypotheses. Adolescents reported on violent delinquency and on callous-unemotional (CU) traits at age 15, on their media habits at age 16 and on reactive and proactive aggression and CU traits at age 18. The socialization hypothesis was supported with regard to aggression, that is, violent delinquency did not affect consumption of violent action, but controlling for violent delinquency, consumption of violent action added to proactive aggression and, marginally, to reactive aggression. The selection hypothesis was supported with regard to CU traits, that is, high levels of CU traits predicted frequent consumption of violent action, but consumption of violent action did not affect later levels of CU traits. Frequent violent media use was associated with later aggression. The associations between CU traits and violent media need further study.

  16. Sunlight and Skin Cancer: Lessons from the Immune System

    OpenAIRE

    Ullrich, Stephen E

    2007-01-01

    The ultraviolet (UV) radiation in sunlight induces skin cancer development. Skin cancer is the most common form of human neoplasia. Estimates suggest that in excess of 1.5 million new cases of skin cancer (www.cancer.org/statistics) will be diagnosed in the United States this year Fortunately, because of their highly visible location, skin cancers are more rapidly diagnosed and more easily treated than other types of cancer. Be that as it may, approximately 10,000 Americans a year die from sk...

  17. Sunlight and Skin Cancer: Lessons from the Immune System

    OpenAIRE

    Ullrich, Stephen E

    2007-01-01

    The ultraviolet (UV) radiation in sunlight induces skin cancer development. Skin cancer is the most common form of human neoplasia. Estimates suggest that in excess of 1.5 million new cases of skin cancer (www.cancer.org/statistics) will be diagnosed in the United States this year Fortunately, because of their highly visible location, skin cancers are more rapidly diagnosed and more easily treated than other types of cancer. Be that as it may, approximately 10,000 Americans a year die from sk...

  18. Characterization of Multi Crystalline PV Modules under Standard Test Conditions and its Comparison with other Module Types

    Directory of Open Access Journals (Sweden)

    Rahnuma. Siddiqui

    2014-06-01

    Full Text Available Photovoltaic modules based on the relatively high efficiency crystalline technology are gaining importance in the photovoltaic market. Improving module performance is driven by a focus on lifetime yields and requirements of space – constraints sites. The materials used not only in thin film technologies but also crystalline pose problems in terms of measuring how much power is generated under STC. The fact that the modules power rates vary depends both on the amount of time they have been exposed to the sun and on their history of sunlight exposure in order to know the current state of the module. It is necessary to determine an easily accomplishable testing method that ensures the repeatability of the measurements of the power generated. This is essential because in order to have a reliable sample of the PV module population of a large PV plant, a huge no of modules must be measured. This paper shows different tests performed on different commercial crystalline PV modules both multi and mono, in order to find the best way to obtain measurements. A correlation was tested between sun exposure and power measured. A method for obtaining indoor measurements that takes periods of sunlight exposure into account is proposed. Also, temperature and irradiance coefficients were also determined for different technologies in order to obtain accurate measurements. Tests are operated in outdoor exposure and natural sunlight located in Gurgaon Region of Haryana (India as specific composite climate environment, characterized by high irradiation and temperature levels.

  19. A Randomized Rounding Approach for Optimization of Test Sheet Composing and Exposure Rate Control in Computer-Assisted Testing

    Science.gov (United States)

    Wang, Chu-Fu; Lin, Chih-Lung; Deng, Jien-Han

    2012-01-01

    Testing is an important stage of teaching as it can assist teachers in auditing students' learning results. A good test is able to accurately reflect the capability of a learner. Nowadays, Computer-Assisted Testing (CAT) is greatly improving traditional testing, since computers can automatically and quickly compose a proper test sheet to meet user…

  20. Sunlight triggers cutaneous lupus through a CSF-1-dependent mechanism in MRL-Fas(lpr) mice.

    Science.gov (United States)

    Menke, Julia; Hsu, Mei-Yu; Byrne, Katelyn T; Lucas, Julie A; Rabacal, Whitney A; Croker, Byron P; Zong, Xiao-Hua; Stanley, E Richard; Kelley, Vicki R

    2008-11-15

    Sunlight (UVB) triggers cutaneous lupus erythematosus (CLE) and systemic lupus through an unknown mechanism. We tested the hypothesis that UVB triggers CLE through a CSF-1-dependent, macrophage (Mø)-mediated mechanism in MRL-Fas(lpr) mice. By constructing mutant MRL-Fas(lpr) strains expressing varying levels of CSF-1 (high, intermediate, none), and use of an ex vivo gene transfer to deliver CSF-1 intradermally, we determined that CSF-1 induces CLE in lupus-susceptible MRL-Fas(lpr) mice, but not in lupus-resistant BALB/c mice. UVB incites an increase in Møs, apoptosis in the skin, and CLE in MRL-Fas(lpr), but not in CSF-1-deficient MRL-Fas(lpr) mice. Furthermore, UVB did not induce CLE in BALB/c mice. Probing further, UVB stimulates CSF-1 expression by keratinocytes leading to recruitment and activation of Møs that, in turn, release mediators, which induce apoptosis in keratinocytes. Thus, sunlight triggers a CSF-1-dependent, Mø-mediated destructive inflammation in the skin leading to CLE in lupus-susceptible MRL-Fas(lpr) but not lupus-resistant BALB/c mice. Taken together, CSF-1 is envisioned as the match and lupus susceptibility as the tinder leading to CLE.

  1. Evaluation of sunlight induced structural changes and their effect on the photocatalytic activity of V{sub 2}O{sub 5} for the degradation of phenols

    Energy Technology Data Exchange (ETDEWEB)

    Aslam, M. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Ismail, Iqbal M.I. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Salah, Numan [Centre of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chandrasekaran, S. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Qamar, M.Tariq [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Hameed, A., E-mail: afmuhammad@kau.edu.sa [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); National Centre for Physics, Quaid-e-Azam University, Islamabad 44000 (Pakistan)

    2015-04-09

    Highlights: • The interaction of UV photons of sunlight induces defects in V{sub 2}O{sub 5}. • The photon induced defects promotes the trapping and transfer of excited electrons. • The nature of the substituent at 2-position affects the degradation process. • The formation of the intermediates is influenced by the nature of substituents. • The released ions are subjected further transformation. - Abstract: Despite knowing the fact that vanadium pentoxide is slightly soluble in aqueous medium, its photocatalytic activity was evaluated for the degradation of phenol and its derivatives (2-hydroxyphenol, 2-chlorophenol, 2-aminophenol and 2-nitrophenol) in natural sunlight exposure. The prime objective of the study was to differentiate between the homogeneous and heterogeneous photocatalysis incurred by dissolved and undissolved V{sub 2}O{sub 5} in natural sunlight exposure. V{sub 2}O{sub 5} was synthesized by chemical precipitation procedure using Triton X-100 as morphology mediator and characterized by DRS, PLS, Raman, FESEM and XRD. A lower solubility of ∼5% per 100 ml of water at 23 °C was observed after calcination at 600 °C. The study revealed no contribution of the dissolved V{sub 2}O{sub 5} in the photocatalytic process. In sunlight exposure, V{sub 2}O{sub 5} powder exhibited substantial activity for the degradation, however, a low mineralization of phenolic substrates was observed. The initial low activity of V{sub 2}O{sub 5} followed by a sharp increase both in degradation and mineralization in complete spectrum sunlight exposure, was further investigated that revealed the decrease in the bandgap and the reduction in the particle size with the interaction of UV photons (<420 nm) as this effect was not observable in the exposure of visible region of sunlight. The role of the chemically different substituents attached to an aromatic ring at 2-positions and the secondary interaction of released ions during the degradation process with the reactive

  2. Development of the town data base: Estimates of exposure rates and times of fallout arrival near the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, C.B.; McArthur, R.D. [Univ. and Community College System of Nevada, Las Vegas, NV (United States); Hutchinson, S.W. [Mead Johnson Nutritional Group, Evansville, IN (United States)

    1994-09-01

    As part of the U.S. Department of Energy`s Off-Site Radiation Exposure Review Project, the time of fallout arrival and the H+12 exposure rate were estimated for populated locations in Arizona, California, Nevada, and Utah that were affected by fallout from one or more nuclear tests at the Nevada Test Site. Estimates of exposure rate were derived from measured values recorded before and after each test by fallout monitors in the field. The estimate for a given location was obtained by retrieving from a data base all measurements made in the vicinity, decay-correcting them to H+12, and calculating an average. Estimates were also derived from maps produced after most events that show isopleths of exposure rate and time of fallout arrival. Both sets of isopleths on these maps were digitized, and kriging was used to interpolate values at the nodes of a 10-km grid covering the pattern. The values at any location within the grid were then estimated from the values at the surrounding grid nodes. Estimates of dispersion (standard deviation) were also calculated. The Town Data Base contains the estimates for all combinations of location and nuclear event for which the estimated mean H+12 exposure rate was greater than three times background. A listing of the data base is included as an appendix. The information was used by other project task groups to estimate the radiation dose that off-site populations and individuals may have received as a result of exposure to fallout from Nevada nuclear tests.

  3. Effect of humic acids and sunlight on the cytotoxicity of engineered zinc oxide and titanium dioxide nanoparticles to a river bacterial assemblage

    Institute of Scientific and Technical Information of China (English)

    Thabitha P.Dasari; Huey-Min Hwang

    2013-01-01

    The effect of a terrestrial humic acid (HA) and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles (ZnONPs)and titanium dioxide nanoparticles (TiO2NPs) to natural aquatic bacterial assemblages was measured with spread plate counting.The effect of HA (10 and 40 ppm) on the cytotoxicity of ZnONPs and TiO2NPs was tested factorially in the presence and absence of natural sunlight (light irradiation (LI)).The experiment was of full factorial,completely randomized design and the results were analyzed using the General Linear Model in SAS analytical software.The method of least squares means was used to separate the means or combinations of means.We determined the mechanism of toxicity via measurements of oxidative stress and metal ions.The toxicity of ZnONPs and TiO2NPs to natural aquatic bacterial assemblages appears to be concentration dependent.Moreover,the cytotoxicity of ZnONPs and TiO2NPs appeared to be affected by HA concentration,the presence of sunlight irradiation,and the dynamic multiple interactions among these factors.With respect to light versus darkness in the control group,the data indicate that bacterial viability was inhibited more in the light exposure than in the darkness exposure.The same was true in the HA treatment groups.With respect to terrestrial versus Suwanee River HA for a given nanoparticle,in light versus darkness,bacterial viability was more inhibited in the light treatment groups containing the terrestrial HA than in those containing Suwanee River HA.Differences in the extent of reactive oxygen species formation,adsorption/binding of ZnONPs/TiO2NPs by HA,and the levels of free metal ions were speculated to account for the observed cytotoxicity.TEM images indicate the attachment and binding of the tested nanoparticles to natural bacterial assemblages.Besides the individual parameter,significant effects on bacterial viability count were also observed in the following combined treatments

  4. Evidence for Alteration in Chemical and Physical Properties of Water and Modulation of its Biological Functions by Sunlight Transmitted through Color Ranges of the Visible Spectrum-A Novel Study

    Directory of Open Access Journals (Sweden)

    M. Rajeswara Rao

    2005-08-01

    Full Text Available We investigated the changes in the properties of water when exposed to sunlight for 40 days. We hypothesize and prove that solar irradiation to water entraps electromagnetic radiation as potential energy, which becomes kinetic energy in various systems. It is postulated that photochemically-induced energy transfers, associated with individual spectral emission of visible spectrum of solar light, exert diverse influences on biological systems. Bottles of distilled water, individually wrapped in spectral-colored cellophane were exposed to sunlight and compared to an unwrapped bottle to determine chemical and physical changes as well as modifications of biological properties. Each bottle of water was named according to the color of cellophane paper with letter E (stands for exposed as a prefix with (E-violet, E-indigo, E-blue, E-green, E-yellow, E-orange, and Ered. E-control (without wrap was exposed to polychromatic sunlight. This study addresses two main issues viz., the chemical and physical changes in E-water and its effect on biological activities. Chemical and physical composition analysis using inductively coupled plasma atomic emission spectrometry; physical conductance by a Wheatstone Bridge type conductivity meter; osmolarity by a vapor pressure osmometer; and, salt solubility profile of 10% sodium bicarbonate were determined. Furthermore, testing the effect of E-waters on human lymphocyte proliferation, mosquito larvae hatching and seed germination determined the functional role of solar radiation through specific spectrum/s of visible light on various biological processes. We found that water exposed to visible spectral emissions of sunlight had an altered elemental composition, electrical conductance, osmolarity and salt-solubility, as well as differences in bio-modulatory effects. A gradual increase in leaching of Boron from Eviolet to E-red was noted. E-indigo showed maximal increase in electrical conductance and maximal salt

  5. Use of sunlight to degrade oxytetracycline in marine aquaculture's waters.

    Science.gov (United States)

    Leal, J F; Esteves, V I; Santos, E B H

    2016-06-01

    Oxytracycline (OTC) is a broad spectrum antibiotic authorized for use in European aquaculture. Its photo-degradation has been widely studied in synthetic aqueous solutions, sometimes resorting to expensive methods and without proven effectiveness in natural waters. Thus, this work studied the possibility to apply the solar photo-degradation for removal of OTC from marine aquaculture's waters. For that, water samples were collected at different locals of the water treatment circuit, from two different aquaculture companies. Water samples were firstly characterized regarding to pH, salinity, total suspended solids (TSS), organic carbon and UV-Vis spectroscopic characteristics. Then, the samples were spiked with OTC and irradiated using simulated sunlight in order to evaluate the matrix effects on OTC photo-degradation. From kinetic results, the apparent quantum yields and the outdoor half-life times, at 40°N for midsummer and midwinter days were estimated by the first time for these conditions. For a midsummer day, at sea level, the outdoor half-life time predicted for OTC in these aquaculture's waters ranged between 21 and 25 min. Additionally, the pH and salinity effects on the OTC photo-degradation were evaluated and it has been shown that high pH values and the presence of sea salt increase the OTC photo-degradation rate in aquaculture's waters, compared to results in deionised water. The results are very promising to apply this low-cost methodology using the natural sunlight in aquaculture's waters to remove OTC.

  6. Decomposition of S-Nitrosothiols Induced by UV and Sunlight

    Directory of Open Access Journals (Sweden)

    Manoj M. Veleeparampil

    2009-01-01

    Full Text Available Photochemical release of nitric oxide (NO from the S-nitroso derivatives of glutathione, L-cysteine, N-acetyl-L-cysteine, L-cysteinemethylester, D,L-penicillamine, N-acetyl-D,L-penicillamine, and N-acetylcysteamine has been investigated at neutral and acidic pH. The release of NO from RSNO is one of the key reactions that could be utilized in photodynamic therapy. The UV-VIS and HPLC analyses have shown that under argon saturated conditions, disulfide (RSSR is the major product of UV as well as sunlight induced decomposition. While in aerated conditions, nitirite—the end product of the oxidation of NO—was also observed along with disulfide. The formation of thiyl radical as the intermediate was reconfirmed by laser flash photolysis. The initial rate of formation of NO was on the order of 10−10dm3mol−1s−1. The quantum yields of these reactions were in the range of 0.2–0.8. The high quantum yields observed in the photo induced release of NO from RSNO using both UV and sunlight demonstrate the potential application of these reactions in photodynamic therapy.

  7. The impact of sunlight on high-latitude equivalent currents

    CERN Document Server

    Laundal, K M; Østgaard, N; Reistad, J P; Haaland, S; Snekvik, K; Tenfjord, P; Ohtani, S; Milan, S E

    2016-01-01

    Ground magnetic field measurements can be mathematically related to an overhead ionospheric equivalent current. In this study we look in detail at how the global equivalent current, calculated using more than 30 years of SuperMAG magnetometer data, changes with sunlight conditions. The calculations are done using spherical harmonic analysis in quasi-dipole coordinates, a technique which leads to improved accuracy compared to previous studies. Sorting the data according to the location of the sunlight terminator and orientation of the interplanetary magnetic field (IMF), we find that the equivalent current resembles ionospheric convection patterns on the sunlit side of the terminator but not on the dark side. On the dark side, with southward IMF, the current is strongly dominated by a dawn cell and the current across the polar cap has a strong dawnward component. The contrast between the sunlit and dark side increases with increasing values of the $\\mathit{F}_{10.7}$ index, showing that increasing solar EUV fl...

  8. Ontogeny and adolescent alcohol exposure in Wistar rats: open field conflict, light/dark box and forced swim test.

    Science.gov (United States)

    Desikan, Anita; Wills, Derek N; Ehlers, Cindy L

    2014-07-01

    Epidemiological studies have demonstrated that heavy drinking and alcohol abuse and dependence peak during the transition between late adolescence and early adulthood. Studies in animal models have demonstrated that alcohol exposure during adolescence can cause a modification in some aspects of behavioral development, causing the "adolescent phenotype" to be retained into adulthood. However, the "adolescent phenotype" has not been studied for a number of behavioral tests. The objective of the present study was to investigate the ontogeny of behaviors over adolescence/young adulthood in the light/dark box, open field conflict and forced swim test in male Wistar rats. These data were compared to previously published data from rats that received intermittent alcohol vapor exposure during adolescence (AIE) to test whether they retained the "adolescent phenotype" in these behavioral tests. Three age groups of rats were tested (post-natal day (PD) 34-42; PD55-63; PD69-77). In the light/dark box test, younger rats escaped the light box faster than older adults, whereas AIE rats returned to the light box faster and exhibited more rears in the light than controls. In the open field conflict test, both younger and AIE rats had shorter times to first enter the center, spent more time in the center of the field, were closer to the food, and consumed more food than controls. In the forced swim test no clear developmental pattern emerged. The results of the light/dark box and the forced swim test do not support the hypothesis that adolescent ethanol vapor exposure can "lock-in" all adolescent phenotypes. However, data from the open field conflict test suggest that the adolescent and the AIE rats both engaged in more "disinhibited" and food motivated behaviors. These data suggest that, in some behavioral tests, AIE may result in a similar form of behavioral disinhibition to what is seen in adolescence.

  9. Developing testing methods for characterizing emissions and sources of exposures from polyurehane products

    Science.gov (United States)

    The relationship between onsite manufacture of spray polyurethane foam insulation (SPFI) and potential exposures to diisocyanate compounds, amine catalysts, flame retardants, and blowing agents, as well as aldehydes and other volatile or semivolatile organic compounds that may be...

  10. Multimedia Field Test Thinking About Exposures? There's an App for That!

    Science.gov (United States)

    Carper, Matthew M

    2017-02-01

    Anxiety Coach is a smartphone application ("app") for iOS devices that is billed as a self-help program for anxiety in youth and adults. The app is currently available in the iTunes store for a one-time fee of $4.99. Anxiety Coach is organized around three related content areas: (a) self-monitoring of anxiety symptoms, (b) learning about anxiety and its treatment, and (c) guiding users through the development of a fear hierarchy and completion of exposure tasks. Although the app includes psychoeducation about anxiety as well as information regarding specific skills individuals can use to cope with anxiety (e.g., cognitive restructuring), the primary focus of the app is on exposure tasks. As such, the app includes a large library of potential exposure tasks that are relevant to treating common fears and worries, making Anxiety Coach useful to clients and clinicians alike. Additionally, Anxiety Coach prompts users to provide fear ratings while they are carrying out an exposure task and displays a message instructing users to stop the exposure once fear ratings drop by half. These features work together to create an app that has the potential to greatly increase the reach of exposure-based cognitive behavioral therapy for anxiety.

  11. Second-phase validation study of short time exposure test for assessment of eye irritation potency of chemicals.

    Science.gov (United States)

    Kojima, Hajime; Hayashi, Kazuhiko; Sakaguchi, Hitoshi; Omori, Takashi; Otoizumi, Takuya; Sozu, Takashi; Kuwahara, Hirofumi; Hayashi, Takumi; Sakaguchi, Mayumi; Toyoda, Akemi; Goto, Haruka; Watanabe, Shinichi; Ahiko, Kyoko; Nakamura, Tsuneaki; Morimoto, Takashi

    2013-09-01

    A Short Time Exposure (STE) test is a cytotoxicity test that uses SIRC cells (rabbit corneal cell line) to assess eye irritation potency following a 5-min chemical exposure. This second-phase validation study assessed the predictive capacity of the STE test using 40 coded test substances at three laboratories. A Validation Management Team (VMT) then evaluated the predictivity of the STE test for United Nation (UN) Globally Harmonized System (GHS) categories using 63 test substances including the results of the first-phase validation study. The STE test can assess not only the severe or corrosive ocular irritants (corresponding to the UN GHS Category 1) but also non-irritant (corresponding to UN GHS Non Category) from other toxicity classes, especially for limited types of test substances. The predictivity by STE test, however, was insufficient for identification of UN GHS categories (Category 1, Category 2, or Non Category). These results suggest that the STE test can be recommended as an initial step in a top-down approach to identification of severe irritants and test substances that require classification for eye irritation (UN GHS Category 1) as well as an initial step in a bottom-up approach to identification of test substances that do not require classification for eye irritation (UN GHS Non Category) from other toxicity classes, especially for limited types of test substances. On the other hand, the STE test is not considered adequate for the identification of mild or moderate irritants (i.e., UN GHS Categories 2A and 2B) and severe irritants (UN GHS Category 1).

  12. A novel solar cell fabricated with spiral photo-electrode for capturing sunlight 3-dimensionally

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; SHEN Hui; DENG Youjun

    2006-01-01

    A novel solar cell fabricated with spiral photo-electrode for capturing sunlight 3-dimensionally (3D-cell) is proposed in this paper. We studied its performance both in solar simulator and in nature sunlight. Spiral photo-electrode of 3D-cell can receive sunlight from all directions and therefore can track the sun passively. And it is much insensitive to solar azimuth angle and shade. In addition, it increases the area to obtain scattered sunlight and reflected light. Compared with the dye-sensitized solar cells using sandwich structure, it would be more advantageous in the sealing technique.

  13. Sunlight-induced carbon dioxide emissions from inland waters

    Science.gov (United States)

    Koehler, Birgit; Landelius, Tomas; Weyhenmeyer, Gesa A.; Machida, Nanako; Tranvik, Lars J.

    2014-07-01

    The emissions of carbon dioxide (CO2) from inland waters are substantial on a global scale. Yet the fundamental question remains open which proportion of these CO2 emissions is induced by sunlight via photochemical mineralization of dissolved organic carbon (DOC), rather than by microbial respiration during DOC decomposition. Also, it is unknown on larger spatial and temporal scales how photochemical mineralization compares to other C fluxes in the inland water C cycle. We combined field and laboratory data with atmospheric radiative transfer modeling to parameterize a photochemical rate model for each day of the year 2009, for 1086 lakes situated between latitudes from 55°N to 69°N in Sweden. The sunlight-induced production of dissolved inorganic carbon (DIC) averaged 3.8 ± 0.04 g C m-2 yr-1, which is a flux comparable in size to the organic carbon burial in the lake sediments. Countrywide, 151 ± 1 kt C yr-1 was produced by photochemical mineralization, corresponding to about 12% of total annual mean CO2 emissions from Swedish lakes. With a median depth of 3.2 m, the lakes were generally deep enough that incoming, photochemically active photons were absorbed in the water column. This resulted in a linear positive relationship between DIC photoproduction and the incoming photon flux, which corresponds to the absorbed photons. Therefore, the slope of the regression line represents the wavelength- and depth-integrated apparent quantum yield of DIC photoproduction. We used this relationship to obtain a first estimate of DIC photoproduction in lakes and reservoirs worldwide. Global DIC photoproduction amounted to 13 and 35 Mt C yr-1 under overcast and clear sky, respectively. Consequently, these directly sunlight-induced CO2 emissions contribute up to about one tenth to the global CO2 emissions from lakes and reservoirs, corroborating that microbial respiration contributes a substantially larger share than formerly thought, and generate annual C fluxes similar in

  14. Railway noise annoyance: exposure-response relationships and testing a theoretical model by structural equation analysis.

    Science.gov (United States)

    Pennig, Sibylle; Schady, Arthur

    2014-01-01

    In some regions the exposure to railway noise is extremely concentrated, which may lead to high residential annoyance. Nonacoustical factors contribute to these reactions, but there is limited evidence on the interrelations between the nonacoustical factors that influence railway noise annoyance. The aims of the present study were (1) to examine exposure-response relationships between long-term railway noise exposure and annoyance in a region severely affected by railway noise and (2) to determine a priori proposed interrelations between nonacoustical factors by structural equation analysis. Residents (n = 320) living close to railway tracks in the Middle Rhine Valley completed a socio-acoustic survey. Individual noise exposure levels were calculated by an acoustical simulation model for this area. The derived exposure-response relationships indicated considerably higher annoyance at the same noise exposure level than would have been predicted by the European Union standard curve, particularly for the night-time period. In the structural equation analysis, 72% of the variance in noise annoyance was explained by the noise exposure (L(den)) and nonacoustical variables. The model provides insights into several causal mechanisms underlying the formation of railway noise annoyance considering indirect and reciprocal effects. The concern about harmful effects of railway noise and railway traffic, the perceived control and coping capacity, and the individual noise sensitivity were the most important factors that influence noise annoyance. All effects of the nonacoustical factors on annoyance were mediated by the perceived control and coping capacity and additionally proposed indirect effects of the theoretical model were supported by the data.

  15. Railway noise annoyance: Exposure-response relationships and testing a theoretical model by structural equation analysis

    Directory of Open Access Journals (Sweden)

    Sibylle Pennig

    2014-01-01

    Full Text Available In some regions the exposure to railway noise is extremely concentrated, which may lead to high residential annoyance. Nonacoustical factors contribute to these reactions, but there is limited evidence on the interrelations between the nonacoustical factors that influence railway noise annoyance. The aims of the present study were (1 to examine exposure-response relationships between long-term railway noise exposure and annoyance in a region severely affected by railway noise and (2 to determine a priori proposed interrelations between nonacoustical factors by structural equation analysis. Residents (n = 320 living close to railway tracks in the Middle Rhine Valley completed a socio-acoustic survey. Individual noise exposure levels were calculated by an acoustical simulation model for this area. The derived exposure-response relationships indicated considerably higher annoyance at the same noise exposure level than would have been predicted by the European Union standard curve, particularly for the night-time period. In the structural equation analysis, 72% of the variance in noise annoyance was explained by the noise exposure (Lden and nonacoustical variables. The model provides insights into several causal mechanisms underlying the formation of railway noise annoyance considering indirect and reciprocal effects. The concern about harmful effects of railway noise and railway traffic, the perceived control and coping capacity, and the individual noise sensitivity were the most important factors that influence noise annoyance. All effects of the nonacoustical factors on annoyance were mediated by the perceived control and coping capacity and additionally proposed indirect effects of the theoretical model were supported by the data.

  16. Testing of various membranes for use in a novel sediment porewater isolation chamber for infaunal invertebrate exposure to PCBs.

    Science.gov (United States)

    Coleman, Jessica G; Lotufo, Guilherme R; Kennedy, Alan J; Poda, Aimee R; Rushing, Todd S; Ruiz, Carlos E; Bridges, Todd S

    2014-07-01

    In benthic sediment bioassays, determining the relative contribution to exposure by contaminants in overlying water, porewater, and sediment particles is technically challenging. The purpose of the present study was to assess the potential for membranes to be utilized as a mechanism to allow freely dissolved hydrophobic organic contaminants into a pathway isolation exposure chamber (PIC) while excluding all sediment particles and dissolved organic carbon (DOC). This investigation was conducted in support of a larger effort to assess contaminant exposure pathways to benthos. While multiple passive samplers exist for estimating concentrations of contaminants in porewater such as those using solid-phase micro extraction (SPME) and polyoxymethylene (POM), techniques to effectively isolate whole organism exposure to porewater within a sediment system are not available. We tested the use of four membranes of different pore sizes (0.1-1.2μm) including nylon, polycarbonate, polyethylsulfone, and polytetrafluoroethylene with a hydrophilic coating. Exposures included both diffusion of radiolabeled and non-labeled contaminants across membranes from aqueous, sediment slurry, and whole sediment sources to assess and evaluate the best candidate membrane. Data generated from the present study was utilized to select the most suitable membrane for use in the larger bioavailability project which sought to assess the relevance of functional ecology in bioavailability of contaminated sediments at remediation sites. The polytetrafluoroethylene membrane was selected for use in the PIC, although exclusion of dissolved organic carbon was not achieved.

  17. Low dose prenatal alcohol exposure does not impair spatial learning and memory in two tests in adult and aged rats.

    Directory of Open Access Journals (Sweden)

    Carlie L Cullen

    Full Text Available Consumption of alcohol during pregnancy can have detrimental impacts on the developing hippocampus, which can lead to deficits in learning and memory function. Although high levels of alcohol exposure can lead to severe deficits, there is a lack of research examining the effects of low levels of exposure. This study used a rat model to determine if prenatal exposure to chronic low dose ethanol would result in deficits in learning and memory performance and if this was associated with morphological changes within the hippocampus. Sprague Dawley rats were fed a liquid diet containing 6% (vol/vol ethanol (EtOH or an isocaloric control diet throughout gestation. Male and Female offspring underwent behavioural testing at 8 (Adult or 15 months (Aged of age. Brains from these animals were collected for stereological analysis of pyramidal neuron number and dendritic morphology within the CA1 and CA3 regions of the dorsal hippocampus. Prenatal ethanol exposed animals did not differ in spatial learning or memory performance in the Morris water maze or Y maze tasks compared to Control offspring. There was no effect of prenatal ethanol exposure on pyramidal cell number or density within the dorsal hippocampus. Overall, this study indicates that chronic low dose prenatal ethanol exposure in this model does not have long term detrimental effects on pyramidal cells within the dorsal hippocampus or impair spatial learning and memory performance.

  18. Asteroid thermal modeling in the presence of reflected sunlight

    Science.gov (United States)

    Myhrvold, Nathan

    2016-10-01

    This study addresses thermal modeling of asteroids with a new derivation of the Near Earth Asteroid Thermal (NEATM) model which correctly accounts for the presence of reflected sunlight in short wave IR bands. Kirchhoff's law of thermal radiation applies to this case and has important implications. New insight is provided into the ???? parameter in the NEATM model and it is extended to thermal models besides NEATM. The role of surface material properties on ???? is examined using laboratory spectra of meteorites and other asteroid compositional proxies; the common assumption that emissivity ????=0.9 in asteroid thermal models may not be justified and can lead to misestimating physical parameters. In addition, indeterminacy in thermal modeling can limit its ability to uniquely determine temperature and other physical properties. A new curve-fitting approach allows thermal modeling to be done independently of visible-band observational parameters, such as the absolute magnitude ????.

  19. Spectral analysis of red scattered sunlight at sunrise

    CERN Document Server

    Zagury, F; Zagury, Frederic; Fujii, Mitsugu

    2003-01-01

    We analyze and fit visible spectra of a red horizon at sunrise. The shape of the spectra consist of a blue continuum followed by a red bump. The reddest spectra are well fitted by the product of a spectrum of extinguished sunlight (Rayleigh extinction + ozone absorption) and 1/lambda^4. The former is essentially the radiation field in the outer atmosphere, at the scattering volume location; the latter corresponds to Rayleigh scattering by the gas. Moving to higher altitudes, a second component, corresponding to the spectrum of a blue sky, must be added. The spectra we have obtained are similar to spectra of red nebulae, suggesting there may be other explanations than an emission process to the red color of some nebulae.

  20. Sustainable sunlight to biogas is via marginal organics.

    Science.gov (United States)

    Shilton, Andy; Guieysse, Benoit

    2010-06-01

    Although biogas production from algae offers higher sunlight to biomass energy conversion efficiencies its production costs simply cannot compete with terrestrial plants. Unfortunately terrestrial plant cropping for biogas production is, in its own right, neither particularly sustainable nor profitable and its ongoing application is only driven by energy security concerns resulting in taxpayer subsidies. By comparison, scavenging the organic energy residual/wastes from food production offers a far more profitable and sustainable proposition and has an energy potential that dwarfs anything biogas production from dedicated energy crops can realistically offer. Thus researchers wanting to assist the development of sustainable biogas systems with viable process economics should forget about terrestrial and algal energy cropping and focus on the realm of scavengers.

  1. Circadian clocks optimally adapt to sunlight for reliable synchronization

    CERN Document Server

    Hasegawa, Yoshihiko

    2014-01-01

    Circadian oscillation provides selection advantages through synchronization to the daylight cycle. However, a reliable clock must be designed through two conflicting properties: entrainability to properly respond to external stimuli such as sunlight, and regularity to oscillate with a precise period. These two aspects do not easily coexist because better entrainability favors higher sensitivity, which may sacrifice the regularity. To investigate conditions for satisfying the two properties, we analytically calculated the optimal phase-response curve with a variational method. Our result indicates an existence of a dead zone, i.e., a time during which external stimuli neither advance nor delay the clock. This result is independent of model details and a dead zone appears only when the input stimuli obey the time course of actual insolation. Our calculation demonstrates that every circadian clock with a dead zone is optimally adapted to the daylight cycle. Our result also explains the lack of a dead zone in osc...

  2. Good performance of rapid prostate-specific antigen test for detection of semen exposure in women: implications for qualitative research.

    Science.gov (United States)

    Hobbs, Marcia M; Steiner, Markus J; Rich, Kimberly D; Gallo, Maria F; Alam, Anadil; Rahman, Motiur; Menezes, Prema; Chipato, Tsungai; Warner, Lee; Macaluso, Maurizio

    2009-08-01

    Prostate-specific antigen (PSA) is a valid biomarker of semen exposure in women and has been used to assess reliability of self-reported sexual behavior as well as serve as a proxy measure for condom efficacy. Quantitative PSA tests are expensive and require specialized equipment. A simple, rapid, and inexpensive test for PSA would facilitate semen biomarker evaluation in a variety of research settings. This study evaluated the performance of a rapid PSA test compared with a quantitative assay to identify semen in vaginal swab specimens. We tested 581 vaginal swabs collected from 492 women participating in 2 separate research studies in Bangladesh and Zimbabwe. PSA in vaginal secretions was detected using the quantitative IMx (Abbott Laboratories) assay and the ABAcard p30 (Abacus Diagnostics) rapid immunochromatographic strip test. The ABAcard test was 100% sensitive (95% confidence interval [CI], 98%-100%) and 96% specific (95% CI, 93%-97%) compared with the quantitative test in detecting >1.0 ng PSA/mL vaginal swab eluate. Rapid PSA results were semiquantitative and correlated well with PSA concentrations (kappa = 0.88; 95% CI, 0.85-0.90). Rapid PSA detection requires no instrumentation and can be performed easily and economically. Having rapid PSA results available immediately following interview provides opportunities to explore discrepancies between the objective marker of recent semen exposure and self-reported behaviors.

  3. Using eyeblink classical conditioning as a test of the functional consequences of exposure of the developing cerebellum to alcohol.

    Science.gov (United States)

    Green, John T

    2003-01-01

    Exposure of the developing brain to alcohol produces profound Purkinje cell loss in the cerebellum, and deficits in tests of motor coordination. However, the precise relationship between these two sets of findings has been difficult to determine. Eyeblink classical conditioning is known to engage a discrete brainstem-cerebellar circuit, making it an ideal test of cerebellar functional integrity after developmental alcohol exposure. In eyeblink conditioning, one of the deep cerebellar nuclei, the interpositus nucleus, as well as specific Purkinje cell populations, are sites of convergence for CS and US information. A series of studies have shown that eyeblink conditioning is impaired in both weanling and adult rats given binge-like exposure to alcohol as neonates, and that these deficits can be traced, at least in part, to impaired activation of cerebellar interpositus nucleus neurons and to an overall reduction in the deep cerebellar nuclear cell population. Because particular cerebellar cell populations are utilized in well-defined ways during eyeblink conditioning, conclusions regarding specific changes in the mediation of behavior by these cell populations are greatly strengthened. Further studies will be directed towards the impact of early exposure to alcohol on the functionality of specific Purkinje cell populations, as well as towards brainstem areas that process the tone CS and the somatosensory US.

  4. Integrated exposure and dose modeling and analysis system. 1. Formulation and testing of microenvironmental and pharmacokinetic components

    Energy Technology Data Exchange (ETDEWEB)

    Georgopoulos, P.G.; Walia, A.; Roy, A.; Lioy, P.J. [Rutgers Univ. and Univ. of Medicine & Dentistry of New Jersey, Piscataway, NJ (United States)

    1997-01-01

    The conceptual and theoretical framework for a modular integrated Exposure and Dose Modeling and Analysis System (EDMAS) has been formulated, and its stepwise implementation and testing is currently in progress. This system aims to provide state-of-the art tools for performing integrated assessments of exposure and dose for individuals and populations. The integration of modeling components with each other as well as with available environmental, exposure, and toxicological databases in being accomplished with the use of computational tools that include interactive simulation environments, Geographical information Systems, and various data retrieval, management, statistical analysis, and visualization methods. This paper overviews the structure and modular nature of this integrated modeling system and focuses specifically on two of its components: (a) a hierarchy of physiologically based pharmacokinetic models (PBPKM), representing various levels of detail and sophistication, and (b) a family of microenvironmental models, that incorporate complex physical and chemical transformations. The deterministic implementation of these components is also presented here in two test applications: (i) a case study of benzene exposure indoors resulting from the volatilization of contaminated tap water and (ii) a case study of photochemical pollution infiltration indoors, in an office building environment. 77 refs., 6 figs., 2 tabs.

  5. Natural sunlight irradiated flower-like CuS synthesized from DMF solvothermal treatment

    Science.gov (United States)

    Zhao, Wei; Wang, Zihao; Zhou, Lei; Liu, Nianqi; Wang, Hongxing

    2016-09-01

    Three-dimensional CuS hierarchical crystals with high catalytic activity had been successfully fabricated using a facile solvothermal process. The CuS microparticles showed different flower-like morphology and good dispersion by optimizing reaction conditions. It was found that using N,N-dimethylformamide (DMF) as the solvent reagent in the proper temperature conditions was favorable for the growth of hierarchically structured CuS. The hexagonal flower-like CuS synthesized at 170°C for 60 min displayed broad-spectrum photocatalytic properties under ultraviolet (UV) and visible irradiation. The as-prepared CuS crystals exhibited good performance to decolorize methylene blue (MB) solution under visible light irradiation. The total organic carbon (TOC) removal of rhodamine B (RhB) solution was nearly 60% after 5 h of the natural sunlight irradiation, and the property was stable after testing over four recycles, demonstrating a potential application in waster water treatment.

  6. Exposure to Music and Cognitive Performance: Tests of Children and Adults

    Science.gov (United States)

    Schellenberg, E. Glenn; Nakata, Takayuki; Hunter, Patrick G.; Tamoto, Sachiko

    2007-01-01

    This article reports on two experiments of exposure to music and cognitive performance. In Experiment 1, Canadian undergraduates performed better on an IQ subtest (Symbol Search) after listening to an up-tempo piece of music composed by Mozart in comparison to a slow piece by Albinoni. The effect was evident, however, only when the two pieces also…

  7. Community Violence Exposure and Aggression among Urban Adolescents: Testing a Cognitive Mediator Model

    Science.gov (United States)

    McMahon, Susan D.; Felix, Erika D.; Halpert, Jane A.; Petropoulos, Lara A. N.

    2009-01-01

    Past research has shown that exposure to violence leads to aggressive behavior, but few community-based studies have examined theoretical models illustrating the mediating social cognitive processes that explain this relation with youth exposed to high rates of violence. This study examines the impact of community violence on behavior through…

  8. Testing a procedural variant of written imaginal exposure for generalized anxiety disorder.

    Science.gov (United States)

    Fracalanza, Katie; Koerner, Naomi; Antony, Martin M

    2014-08-01

    This experiment examined the degree to which it is more beneficial for individuals with generalized anxiety disorder (GAD) to engage in repeated exposure to mental imagery of the same feared scenario versus varying the exposure content. On three consecutive days, individuals with GAD (N=57) spent 20min writing about: (1) the same worst case scenario (consistent exposure; CE), (2) variations of their worst case scenario (varied exposure; VE), or (3) a neutral topic (neutral control; NC). Participants in the CE condition displayed significant decreases in worry, acute cognitive avoidance, and intolerance of uncertainty from baseline to 1-week follow-up; participants in the VE and NC conditions did not. Initial activation of self-reported anxiety (observed in the CE and VE conditions) and between-session reduction in anxiety (observed in the CE condition only) were associated with improvement in worry. Including more references to negative emotion and writing in the present tense were also associated with greater improvement in worry in the CE condition. These findings suggest that writing repeatedly about the same worst case scenario may benefit people with GAD. The study also provides information on potential mechanisms of change.

  9. Exposure to Music and Cognitive Performance: Tests of Children and Adults

    Science.gov (United States)

    Schellenberg, E. Glenn; Nakata, Takayuki; Hunter, Patrick G.; Tamoto, Sachiko

    2007-01-01

    This article reports on two experiments of exposure to music and cognitive performance. In Experiment 1, Canadian undergraduates performed better on an IQ subtest (Symbol Search) after listening to an up-tempo piece of music composed by Mozart in comparison to a slow piece by Albinoni. The effect was evident, however, only when the two pieces also…

  10. Performance of QuantiFERON-TB Gold and tuberculin skin test relative to subjects' risk of exposure to tuberculosis.

    Science.gov (United States)

    McMullen, Sharon E; Pegues, David A; Shofer, Frances S; Sheller, Alexandra C; Wiener, Evelyn B

    2014-05-01

    Performance of QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) has not been compared in a US college population with varying risk of tuberculosis exposure. We performed a retrospective chart review of students tested for tuberculosis at the University of Pennsylvania Student Health Service between 2009 and 2011. We stratified students into high-, low-, and no-risk categories for exposure to tuberculosis and compared QFT-GIT and TST performance in risk groups adjusting demographic characteristics. During the study period, 15 936 tuberculosis tests were performed in 9483 college students. Coming from a tuberculosis-endemic country was the only risk factor significantly associated with having a positive result (odds ratio [OR] 12.9; 95% confidence interval [CI], 10.2-16.5). Test specificity was higher for TST than QFT-GIT (99.7% vs 91.4%; P tuberculosis testing and the use of risk-stratified interpretation for students who are tested with QFT-GIT.

  11. Surrogate testing suggests that chlorine dioxide gas exposure would not inactivate Ebola virus contained in environmental blood contamination.

    Science.gov (United States)

    Lowe, John J; Hewlett, Angela L; Iwen, Peter C; Smith, Philip W; Gibbs, Shawn G

    2015-05-08

    The ability to decontaminate a room potentially containing the Ebola virus is important to healthcare facilities in the United States. Ebola virus remains viable in body fluids, a room that has housed a patient with Ebola virus disease must have all surfaces manually wiped with an approved disinfectant, which increases occupational exposure risk. This study evaluated the efficacy of gaseous chlorine dioxide inactivation of bacterial organisms in blood as Ebola virus surrogates and as the organisms used by the Nebraska Biocontainment Unit to provide the margin of safety for decontamination. Bacillus anthracis, Escherichia coli, Enterococcus faecalis, and Mycobacterium smegmatis blood suspensions that were exposed to ClO2 gas concentrations and exposure limits. The log reduction in Colony Forming Units (CFU) was determined for each bacterial blood suspension. Exposure parameters approximating industry practices for ClO2 environmental decontamination (360ppm concentration to 780 ppm-hrs exposure, 65% relative humidity) as well as parameters exceeding current practice (1116 ppm concentration to 1400 ppm-hrs exposure; 1342ppm concentration to 1487 ppm-hrs exposure) were evaluated. Complete inactivation was not achieved for any of the bacterial blood suspensions tested. Reductions were observed in concentrations of B. anthracis spores (1.3 -3.76 log) and E. faecalis vegetative cells (1.3 log) whereas significant reductions in vegetative cell concentrations for E. coli and M. smegmatis blood suspensions were not achieved. Our results showed that bacteria in the presence of blood were not inactivated using gaseous ClO2 decontamination. ClO2 decontamination alone should not be used for Ebola virus, but decontamination processes should first include manual wiping of potentially contaminated blood; especially for microorganisms as infectious as the Ebola virus.

  12. A New Approach of Studying Correlation between Outdoor Exposure and Indoor Accelerated Corrosion Test for High Polymer Materials

    Institute of Scientific and Technical Information of China (English)

    YANG Lixia; LI Xiaogang; ZHANG Sanping

    2006-01-01

    The correlation between outdoor exposure and indoor accelerated corrosion test for high polymer materials was investigated according to the variation of the functional group of exposure models aged. Environment aging intensities at different zones ( Wuhan and Lasa with the same latitude ) and the influences of indoor accelerating factors including water and ultraviolet on weathering performance of high polymer materials were also studied by comparing different indoor accelerated corrosion testing results. The experimental results show that: by testing variations of carbonyl exponent of polythene ( which represented the degradation behavior of highpolymer materials due to ultraviolet oxidation of double bond) and ultraviolet absorbance of polycarbonate ( which represented the degradation behavior of high polymer materials due to abevacuation of branched chain), the degradation behavior of high polymer materials could be studied. Carbonyl exponent of polythene exposed in Wuhan and Lasa for 1 year was equal to that exposed in indoor cycle ultraviolet for 128 h and 170 h, respectively, the ultraviolet absorbance of polycarbonate exposed in Wuhan for 1 year was equal to that exposed in indoor cycle ultraviolet for 240 h. The ratio of environment aging intensity of Lasa to Wuhan was around 1.2. With the prolongation of cycle accelerated ultraviolet exposure time, the variations of carbonyl exponent of polythene and the ultraviolet absorbance of polycarbonate were in the same shape of first order exponential decay curve. Accompanied with ultraviolet, the effect of water condensated on the sample on weathering performance of polythene was more significant than that of polycarbonate.

  13. A study of pulmonary function test among tea garden factory workers in relation to exposure of tea dust

    Directory of Open Access Journals (Sweden)

    Birinchi Kartik Das

    2015-10-01

    Results: The investigator is interested to test whether there were significant differences between parameters of PFT among the study and control group. For this purpose student t test has been applied and significant differences were found in all the parameters of PFT as P < 0.01. Conclusions: Exposure to tea dust affects the lung volumes and flow rates, thereby causing increased prevalence of respiratory, allergic symptoms and significant degree of airway obstruction. [Int J Res Med Sci 2015; 3(10.000: 2686-2693

  14. Testing Augmented Reality for Cue Exposure in Obese Patients: An Exploratory Study.

    Science.gov (United States)

    Pallavicini, Federica; Serino, Silvia; Cipresso, Pietro; Pedroli, Elisa; Chicchi Giglioli, Irene Alice; Chirico, Alice; Manzoni, Gian Mauro; Castelnuovo, Gianluca; Molinari, Enrico; Riva, Giuseppe

    2016-02-01

    Binge eating is one of the key behaviors in relation to the etiology and severity of obesity. Cue exposure with response prevention consists of exposing patients to binge foods while actual eating is not allowed. Augmented reality (AR) has the potential to change the way cue exposure is administered, but very few prior studies have been conducted so far. Starting from these premises, this study was aimed to (a) investigate whether AR foods elicit emotional responses comparable to those produced by the real stimuli, (b) study differences between obese and control participants in terms of emotional responses to food, and (c) compare emotional responses to different categories of foods. To reach these goals, we assess in 15 obese (age, 44.6 ± 13 years; body mass index [BMI], 44.2 ± 8.1) and 15 control participants (age, 43.7 ± 12.8 years; BMI, 21.2 ± 1.4) the emotional responses to high-calorie (savory and sweet) and low-calorie food stimuli, presented through different exposure conditions (real, photographic, and AR). The State-Trait Anxiety Inventory was used for the assessment of state anxiety, and it was administered at the beginning and after the exposure to foods, along with the Visual Analog Scale (VAS) for Hunger and Happiness. To assess the perceived pleasantness, the VAS for Palatability was administered after the exposure to food stimuli. Heart rate, skin conductance response, and facial corrugator supercilii muscle activation were recorded. Although preliminary, the results showed that (a) AR food stimuli were perceived to be as palatable as real stimuli, and they also triggered a similar arousal response; (b) obese individuals showed lower happiness after the exposure to food compared to control participants, with regard to both psychological and physiological responses; and (c) high-calorie savory (vs. low-calorie) food stimuli were perceived by all the participants to be more palatable, and they triggered a greater arousal response.

  15. Accounting for differing exposure patterns between laboratory tests and the field in the assessment of long-term risks of pesticides to terrestrial vertebrates.

    Science.gov (United States)

    Fischer, David L

    2005-11-01

    Long-term risks of pesticides to birds and mammals are currently assessed by comparing effects thresholds determined in chronic laboratory studies to exposure levels expected to occur in the field. However, there is often a mismatch between exposure patterns tested in the laboratory tests (exposure levels held constant) and those experienced by animals in the field (exposure levels varying over time). Three methods for addressing this problem are presented and discussed. Time-weighted averaging (TWA) converts a variable field exposure regime to a single value that can be compared directly to the laboratory test results. Body-burden modeling (BBM) is applied to both laboratory and field exposure regimes allowing a straightforward comparison of body residue levels expected for each situation. Temporal analysis (TA) uses expert judgment to decide if the length of time exposure exceeds a toxicity threshold is long enough to cause biologically significant effects. To reduce uncertainty in long-term assessments, the conduct of specialized laboratory tests in which test subjects are administered a time-varying exposure that mimics what occurs in the field should be considered. Such tests may also be useful testing the validity of each of these assessment methods.

  16. Integrated Lateral Flow Test Strip with Electrochemical Sensor for Quantification of Phosphorylated Cholinesterase: Biomarker of Exposure to Organophosphorus Agents

    Energy Technology Data Exchange (ETDEWEB)

    Du, Dan; Wang, Jun; Wang, Limin; Lu, Donglai; Lin, Yuehe

    2012-02-08

    An integrated lateral flow test strip with electrochemical sensor (LFTSES) device with rapid, selective and sensitive response for quantification of exposure to organophosphorus (OP) pesticides and nerve agents has been developed. The principle of this approach is based on parallel measurements of post-exposure and baseline acetylcholinesterase (AChE) enzyme activity, where reactivation of the phosphorylated AChE is exploited to enable measurement of total amount of AChE (including inhibited and active) which is used as a baseline for calculation of AChE inhibition. Quantitative measurement of phosphorylated adduct (OP-AChE) was realized by subtracting the active AChE from the total amount of AChE. The proposed LFTSES device integrates immunochromatographic test strip technology with electrochemical measurement using a disposable screen printed electrode which is located under the test zone. It shows linear response between AChE enzyme activity and enzyme concentration from 0.05 to 10 nM, with detection limit of 0.02 nM. Based on this reactivation approach, the LFTSES device has been successfully applied for in vitro red blood cells inhibition studies using chlorpyrifos oxon as a model OP agent. This approach not only eliminates the difficulty in screening of low-dose OP exposure because of individual variation of normal AChE values, but also avoids the problem in overlapping substrate specificity with cholinesterases and avoids potential interference from other electroactive species in biological samples. It is baseline free and thus provides a rapid, sensitive, selective and inexpensive tool for in-field and point-of-care assessment of exposures to OP pesticides and nerve agents.

  17. Polybrominated Diphenyl Ether Exposure and Thyroid Function Tests in North American Adults

    OpenAIRE

    Makey, Colleen M.; McClean, Michael D.; Braverman, Lewis E.; Pearce, Elizabeth N.; He, Xue-Mei; Sjödin, Andreas; Weinberg, Janice M; Webster, Thomas F

    2015-01-01

    Background: Polybrominated diphenyl ethers (PBDEs) are flame-retardant chemicals that are added to many consumer products. Multiple animal studies have shown PBDEs to be thyroid hormone (TH) disruptors. Epidemiologic evidence of PBDE exposure associated with TH disruption has been inconclusive. Objectives: We used repeated measures to estimate associations between serum PBDE concentrations and THs in a North American adult cohort. Methods: From 2010 to 2011, we collected ≤ 3 serum samples at ...

  18. Childhood maltreatment, 9/11 exposure, and latent dimensions of psychopathology: A test of stress sensitization.

    Science.gov (United States)

    Meyers, Jacquelyn L; Lowe, Sarah R; Eaton, Nicholas R; Krueger, Robert; Grant, Bridget F; Hasin, Deborah

    2015-09-01

    On September 11, 2001, a terrorist attack occurred in the U.S. (9/11). Research on 9/11 and psychiatric outcomes has focused on individual disorders rather than the broader internalizing (INT) and externalizing (EXT) domains of psychopathology, leaving unknown whether direct and indirect 9/11 exposure differentially impacted these domains rather than individual disorders. Further, whether such effects were exacerbated by earlier childhood maltreatment (i.e. stress sensitization) is unknown. 18,713 participants from a U.S. national sample with no history of psychiatric disorders prior to 9/11 were assessed using a structured in-person interview. Structural equation modeling conducted in a sample who endorsed no psychiatric history prior to 9/11, indicated that indirect exposure to 9/11 (i.e. media, friends/family) was related to both EXT (alcohol, nicotine, and cannabis dependence, and antisocial personality disorder) and INT (major depression, generalized anxiety, and post-traumatic stress disorder (PTSD)) dimensions of psychopathology (EXT: β = 0.10, p childhood maltreatment, the risk for EXT and INT dimensions associated with 9/11 was exacerbated (Interactions: β = 0.06, p psychopathology in the US general population rather than specific disorders with the exception of PTSD, which had independent effects beyond INT (as indicated by a significant (p childhood maltreatment increases the risk associated with adult trauma exposure, providing further evidence for the concept of stress sensitization.

  19. Validation of the dynamic direct exposure method for toxicity testing of diesel exhaust in vitro.

    Science.gov (United States)

    Joeng, Lucky; Hayes, Amanda; Bakand, Shahnaz

    2013-01-01

    Diesel exhaust emission is a major health concern because of the complex nature of its gaseous content (e.g., NO2, NO, CO, and CO2) and high concentration of particulate matter (PM) less than 2.5  μ m which allows for deeper penetration into the human pulmonary system upon inhalation. The aim of this research was to elucidate the potential toxic effects of diesel exhaust on a human pulmonary-based cellular system. Validation of a dynamic direct exposure method for both laboratory (230 hp Volvo truck engine) and field (Volkswagen Passat passenger car) diesel engines, at idle mode, was implemented. Human pulmonary type II epithelial cells (A549) grown on porous membranes were exposed to unmodified diesel exhaust at a low flow rate (37.5 mL/min). In parallel, diesel emission sampling was also conducted using real-time air monitoring techniques. Induced cellular effects were assessed using a range of in vitro cytotoxicity assays (MTS, ATP, and NRU). Reduction of cell viability was observed in a time-dependent manner following 30-60 mins of exposure with NRU as the most sensitive assay. The results suggest that the dynamic direct exposure method has the potential to be implemented for both laboratory- and field-based in vitro toxicity studies of diesel exhaust emissions.

  20. Abiotic degradation of four phthalic acid esters in aqueous phase under natural sunlight irradiation

    Institute of Scientific and Technical Information of China (English)

    Ruttapol Lertsirisopon; Satoshi Soda; Kazunari Sei; Michihiko Ike

    2009-01-01

    Abiotic degradability of four phthalic acid esters (PAEs) in the aquatic phase was evaluated over the wide pH range (5-9). The PAE solutions in glass test tubes were placed in the dark and under natural sunlight irradiation for evaluating the degradation rate via hydrolysis and photolysis plus hydrolysis, respectively, at ambient temperature for 140 d from autumn to winter in Osaka, Japan. The efficiency of abiotic degradation of the PAEs with relatively short alkyl chain, butylbenzyl phthalate (BBP) and di-n-butyl phthalate (DBP) at neutral pH was significant less than that in the acidic or alkaline condition. Photolysis was considered to mainly contribute to total abiotic degradation at any pH. Neither hydrolysis nor photolysis of di-ethylhexyl phthalate (DEHP) proceeded significantly at any pH, especially hydrolysis at neutral pH was negligible. On the other hand, the degradation rate of di-isononyl phthalate (DINP) mainly catalyzed by photolysis was much higher compared with that of the other PAEs, and almost complete removal was observed during the experimental period at pH 5.0 and 9.0. As a whole, according to the half-life (t1/2) obtained in the experiments, the abiotic degradability of the PAEs was in the sequence, DINP (32-140 d) > DBP (50-360 d), BBP (58-480 d) > DEHP (390-1600 d) under sunlight irradiation (via photolysis plus hydrolysis). Although the abiotic degradation rate for BBP, DBP, and DEHP are much lower than their biodegradation rate reported, the photolysis rate for DINP is comparable to its biodegradation rate in the acidic or alkaline condition.

  1. A-Stratified Computerized Adaptive Testing with Unequal Item Exposure across Strata.

    Science.gov (United States)

    Deng, Hui; Chang, Hua-Hua

    The purpose of this study was to compare a proposed revised a-stratified, or alpha-stratified, USTR method of test item selection with the original alpha-stratified multistage computerized adaptive testing approach (STR) and the use of maximum Fisher information (FSH) with respect to test efficiency and item pool usage using simulated computerized…

  2. Sun protecting and sun exposing behaviors: testing their relationship simultaneously with indicators of ultraviolet exposure among adolescents.

    Science.gov (United States)

    Williams, Melinda; Caputi, Peter; Jones, Sandra C; Iverson, Don

    2011-01-01

    The aim of this study was to build on existing understanding of adolescent sun-related behavior by combining sun protecting and sun exposing behaviors and testing their relationship simultaneously with indicators of ultraviolet (UV) exposure. Data were collected for 692 adolescents aged between 12 and 18 years. General linear modeling was undertaken to test the relationship of sun-related behaviors with indicators of UV exposure. Overall, the combined sun protection and sun exposing behaviors accounted for 13.8% of the variance in the number of sunburns, 28.1% of the variance in current tan and 57.5% of the variance in desired tan, respectively. Results indicated that having a strong desire for a tan was significantly associated with spending time tanning, delaying the use of sun protection, wearing brief clothing and using no sun protection; whereas the number of sunburns was significantly associated with sunscreen use, avoiding peak hours and delaying sun protection. Current tan was significantly associated with wearing sunglasses, shade use and time spent tanning. In examining sun-related behaviors among adolescents, consideration needs to be given to both sun exposing and sun protecting behaviors. This research has important implications for conceptualizing outcomes in programs designed to reduce UV exposure.

  3. Experimental Investigation Of Microbially Induced Corrosion Of Test Samples And Effect Of Self-assembled Hydrophobic Monolayers. Exposure Of Test Samples To Continuous Microbial Cultures, Chemical Analysis, And Biochemical Studies

    CERN Document Server

    Laurinavichius, K S

    1998-01-01

    Experimental Investigation Of Microbially Induced Corrosion Of Test Samples And Effect Of Self-assembled Hydrophobic Monolayers. Exposure Of Test Samples To Continuous Microbial Cultures, Chemical Analysis, And Biochemical Studies

  4. The CRHR1 gene, trauma exposure, and alcoholism risk: a test of G × E effects.

    Science.gov (United States)

    Ray, L A; Sehl, M; Bujarski, S; Hutchison, K; Blaine, S; Enoch, M-A

    2013-06-01

    The corticotropin-releasing hormone type I receptor (CRHR1) gene has been implicated in the liability for neuropsychiatric disorders, particularly under conditions of stress. On the basis of the hypothesized effects of CRHR1 variation on stress reactivity, measures of adulthood traumatic stress exposure were analyzed for their interaction with CRHR1 haplotypes and single-nucleotide polymorphisms (SNPs) in predicting the risk for alcoholism. Phenotypic data on 2533 non-related Caucasian individuals (1167 alcoholics and 1366 controls) were culled from the publically available Study of Addiction: Genetics and Environment genome-wide association study. Genotypes were available for 19 tag SNPs. Logistic regression models examined the interaction between CRHR1 haplotypes/SNPs and adulthood traumatic stress exposure in predicting alcoholism risk. Two haplotype blocks spanned CRHR1. Haplotype analyses identified one haplotype in the proximal block 1 (P = 0.029) and two haplotypes in the distal block 2 (P = 0.026, 0.042) that showed nominally significant (corrected P alcoholism. The block 1 haplotype effect was driven by SNPs rs110402 (P = 0.019) and rs242924 (P = 0.019). In block 2, rs17689966 (P = 0.018) showed significant and rs173365 (P = 0.026) showed nominally significant, gene × environment (G × E) effects on alcoholism status. This study extends the literature on the interplay between CRHR1 variation and alcoholism, in the context of exposure to traumatic stress. These findings are consistent with the hypothesized role of the extra hypothalamic corticotropin-releasing factor system dysregulation in the initiation and maintenance of alcoholism. Molecular and experimental studies are needed to more fully understand the mechanisms of risk and protection conferred by genetic variation at the identified loci.

  5. How much exposure to English is necessary for a bilingual toddler to perform like a monolingual peer in language tests?

    Science.gov (United States)

    Cattani, Allegra; Abbot-Smith, Kirsten; Farag, Rafalla; Krott, Andrea; Arreckx, Frédérique; Dennis, Ian; Floccia, Caroline

    2014-11-01

    Bilingual children are under-referred due to an ostensible expectation that they lag behind their monolingual peers in their English acquisition. The recommendations of the Royal College of Speech and Language Therapists (RCSLT) state that bilingual children should be assessed in both the languages known by the children. However, despite these recommendations, a majority of speech and language professionals report that they assess bilingual children only in English as bilingual children come from a wide array of language backgrounds and standardized language measures are not available for the majority of these. Moreover, even when such measures do exist, they are not tailored for bilingual children. It was asked whether a cut-off exists in the proportion of exposure to English at which one should expect a bilingual toddler to perform as well as a monolingual on a test standardized for monolingual English-speaking children. Thirty-five bilingual 2;6-year-olds exposed to British English plus an additional language and 36 British monolingual toddlers were assessed on the auditory component of the Preschool Language Scale, British Picture Vocabulary Scale and an object-naming measure. All parents completed the Oxford Communicative Development Inventory (Oxford CDI) and an exposure questionnaire that assessed the proportion of English in the language input. Where the CDI existed in the bilingual's additional language, these data were also collected. Hierarchical regression analyses found the proportion of exposure to English to be the main predictor of the performance of bilingual toddlers. Bilingual toddlers who received 60% exposure to English or more performed like their monolingual peers on all measures. K-means cluster analyses and Levene variance tests confirmed the estimated English exposure cut-off at 60% for all language measures. Finally, for one additional language for which we had multiple participants, additional language CDI production scores were

  6. Sunlight activated lanthanide complex for luminescent solar collector applications: effect of waveguide matrix

    Science.gov (United States)

    Shahi, Praveen Kumar; Singh, Priyam; Bahadur Rai, Shyam

    2017-02-01

    The performance of Eu(DBM)3Phen complex (EDP) dispersed in PMMA poly-(methyl methacrylate) polymer matrix, as simple planner luminescent solar collectors (LSCs) is demonstrated using spectroscopic and photovoltaic (PV) measurements. The organic ligands absorb ultra-violet-blue (UV-blue) radiation (220–450 nm) very efficiently and transfer its energy to the Eu3+ ion, which gives an intense red emission even in sunlight exposure. The excellent optical properties of EDP in PMMA permit its coating on the front surface of c-Si solar cell (10  ×  10 cm2) for PV measurements. The PV characterizations reveal the improvement in the short circuit current density (J sc) of PV cell and maximum improvement is found to be 4.6% for 2.5 wt% EDP concentration in PMMA matrix. The efficiency of solar cell increases from 17.22% to 18.33% for bare and 2.5% EDP in PMMA. At a higher concentration of EDP, the thin film starts losing its transparency and hence PV efficiency decreases. These results illustrate that a EDP complex combined with a PV cell could work as a prototype of a new generation solar cell.

  7. Sunlight and Vitamin D: The Bone and Cancer Connections (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Holick, M.F

    2000-07-01

    Vitamin D plays an essential role for calcium metabolism and bone health. It has been estimated that 90 to 95% of our vitamin D requirement comes from casual exposure to sunlight. There is a wide variety of factors that strongly influence the cutaneous production of vitamin D. These include melanin pigmentation, latitude, time of day, sunscreen use, and aging. There is an association with increased risk and mortality to breast, colon, and prostrate cancer. There is evidence that 25-hydroxyvitamin D, the major circulating form of vitamin D, is directly metabolised in prostate, breast, colon, and skin cells to its active form 1,25-dihydroxyvitamin D. 1,25-Dihydroxyvitamin D{sub 3} has the capacity to regulate cell proliferation and differentiation. Therefore, it may be that an increase in the cutaneous synthesis of vitamin D results in the increase in the production of 1,25(OH){sub 2}D in tissues not related to calcium metabolism that results in a decrease in malignancy. (author)

  8. Cognitive test performance following exposure to noise in an open-office simulation study

    DEFF Research Database (Denmark)

    Lund, Søren Peter; Kristiansen, Jesper; Persson, Roger

    Objective: Noise in open-plan offices may increase mental fatigue of the employees at the end of the day. Measurements: 225 employees completed a screening questionnaire. Of these, 50 persons (33 females) who normally worked in open-plan offices agreed to participate in the experiment. All who...... participated completed two counter balanced experimental sessions, one with exposure to simulation of office noise (Leq=55 dB(A)) and one without noise (Leq=50 dB(A)). To simulate a workday, each session lasted about 7 hours, where the participants engaged in different computerised work tasks. Before and after...

  9. Exposure setup to test effects of wireless communications systems on the CNS.

    Science.gov (United States)

    Burkhardt, M; Spinelli, Y; Kuster, N

    1997-11-01

    This paper presents an exposure setup designed for in vivo studies of possible effects on the central nervous system due to the electromagnetic exposure from handheld mobile communications equipment. The setup consists of a carousel on which 10 rats, each restrained in a radially positioned tube, are exposed to the electromagnetic field emanating from a dipole antenna at the center. The rats are positioned with their snouts at a distance of 35 mm from the dipole antenna. The tubes restrain the movement of the animals to such an extent as to allow for well defined exposure conditions, yet without totally immobilizing them. Numerical and experimental dosimetric analysis of the setup was conducted using rats weighing 250-300 g at a frequency of 900 MHz. A detailed rat phantom derived from MRI scans was developed for the numerical assessment with a commercially available code based on the finite integration technique. The results were validated by measurements of the temperature rise in selected points of a rat cadaver. The dosimetric analysis shows that the setup is eminently suitable for central nervous system studies. It enables well defined field strengths to be induced in the brain tissue, whereby the variations in the specific absorption rate averaged over the brain tissue caused by movement and varying animal sizes was shown to be less than +/-16%. The specific absorption rate distribution in the brain is nonhomogeneous but comparable to that induced in the brain of a human using a handheld wireless phone. The efficiency of the exposure is about 0.20+/-0.05 mW g(-1) for the brain average value per 100 mA feedpoint current. The whole-body average specific absorption rate is considerably lower, i.e., about half of that of the brain averaged value. In addition, the setup has been proven to be practical in use, and the stress levels caused by restraining the animals in this setup are deemed by neurologists and veterinary scientists to be very low.

  10. High spacecraft potentials on ISEE-1 in sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Whipple, E.C.; Olsen, R.C.

    1987-01-01

    Data from the two electric-field experiments and from the plasma-composition experiment on ISEE-1 show that the spacecraft charged to close to -70 V in sunlight at about 0700 UT on March 17, 1978. Data from the electron-spectrometer experiment show that there was a potential barrier of some -10 to -20 V about the spacecraft during this event. The potential barrier was effective in turning back emitted photoelectrons to the spacecraft. Potential barriers can be formed by differential charging on the spacecraft or by the presence of space charge. The stringent electrostatic cleanliness specifications imposed on ISEE made by the presence of differential charging seem unlikely, if these precautions were effective. Modeling of this event to determine if the barrier was produced by the presence of space charge, suggested that this could not explain the observed barrier. The angular shape of the distribution could be successfully modeled as a product of differential charging on the solar arrays. This implies that the conductive coating was not completely effective in preventing differential charging, and that differential charging did occur.

  11. Sunlight assisted photodegradation by tin oxide quantum dots

    Science.gov (United States)

    Shajira, P. S.; Prabhu, V. Ganeshchandra; Bushiri, M. Junaid

    2015-12-01

    Rutile phase of SnO2 quantum dots of average size of 2.5 nm were synthesized at a growth temperature of 70 °C and characterized with XRD, TEM, FTIR and Raman analysis. The effective strain within the lattice of SnO2 quantum dots was calculated by Williamson-Hall method. The broad peaks in XRD as well as Raman spectra and the presence of Raman bands at 569 and 432 cm-1 are due to lower crystallinity of nanoparticles. The optical band gap of SnO2 quantum dots was increased to 3.75 eV attributed to the quantum size effect. SnO2 quantum dots were annealed in air atmosphere and the crystallite size of the particles increased with annealing temperature. Sunlight assisted photodegration property of SnO2 quantum dots was investigated with vanillin as a model system and it shows the photodegradation efficiency of 87%. The photoluminescence and photodegradation efficiency of nanocrystallite SnO2 decreases with increase of crystallite size contributed to the reduction in population of defects and surface area.

  12. Sunlight and skin cancer: lessons from the immune system.

    Science.gov (United States)

    Ullrich, Stephen E

    2007-08-01

    The ultraviolet (UV) radiation in sunlight induces skin cancer development. Skin cancer is the most common form of human neoplasia. Estimates suggest that in excess of 1.5 million new cases of skin cancer (www.cancer.org/statistics) will be diagnosed in the United States this year. Fortunately, because of their highly visible location, skin cancers are more rapidly diagnosed and more easily treated than other types of cancer. Be that as it may, approximately 10,000 Americans a year die from skin cancer, and the cost of treating skin cancer in the United States (both melanoma and non-melanoma skin cancer) is estimated to be in excess of $2.9 billion a year. In addition to causing skin cancer, UV radiation is also immune suppressive. In fact, data from studies with both experimental animals and biopsy proven skin cancer patients suggest that there is an association between the immune suppressive effects of UV radiation and its carcinogenic potential. Recent studies in my laboratory have focused on understanding the initial molecular events that induce immune suppression. We made two novel observations: first UV-induced keratinocyte-derived platelet activating factor plays a role in the induction of immune suppression. Second, cis-urocanic acid, a skin-derived immunosuppressive compound mediates immune suppression by binding to serotonin receptors on target cells. Recent findings suggest that blocking the binding of these compounds to their receptors not only inhibits UV-induced immune suppression but it also interferes with skin cancer induction.

  13. Photocatalytic Hydrogen Production by Direct Sunlight: A Laboratory Experiment

    Science.gov (United States)

    Koca, Atif; Sahin, Musa

    2003-11-01

    The demand for hydrogen will increase within the next decades as a result of the necessity to produce clean and environmentally and economically accepted fuels from natural and renewable energy resources. In principle, hydrogen has the potential to play an important role in future energy systems because of the diversity of its applications, the variety of ways in which it can be stored, its general environmental advantages, and especially because of the possibility of producing hydrogen by splitting water using photocatalysts and solar energy. Methods and techniques of photocatalytic reactions are covered in some detail in many undergraduate chemistry programs. However, many times in instructional settings, little attention is given to how it is used for the production of hydrogen. In the present investigation a photocatalytic hydrogen production experiment suitable for use in undergraduate chemistry laboratories is described. The experiment can be used to introduce students to the concept of a renewable and sustainable hydrogen energy system of the future, as well as its production techniques, and to demonstrate the use of a CdS/ZnS photocatalyst system for photocatalytic hydrogen production from direct sunlight.

  14. Interactions of ozone with organic surface films in the presence of simulated sunlight: impact on wettability of aerosols.

    Science.gov (United States)

    Nieto-Gligorovski, L; Net, S; Gligorovski, S; Zetzsch, C; Jammoul, A; D'Anna, B; George, C

    2008-05-28

    Heterogeneous reactions between organic films, taken as proxies for atmospheric aerosols, with ozone in presence of simulated sunlight and the photosensitizer 4-carboxybenzophenone (4-CB) were observed to alter surface properties as monitored by contact angle during the reaction. Attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) was used in addition for product identification. Two types of model surfaces were systematically studied: 4-CB/4-phenoxyphenol and 4-CB/catechol. Solid organic films made of 4-CB/catechol were observed to become hydrophilic by simultaneous exposure to ozone and simulated sunlight, whereas organic films made of 4-CB/4-phenoxyphenol become hydrophobic under the same conditions. These changes in contact angle indicate that photo-induced aging processes involving ozone (such as oligomerisation) not necessarily favour increased hygroscopicity of organic aerosols in the atmosphere. The ratio between hydrophobic and hydrophilic functional groups should reflect the chemical property of organic films with respect to wettability phenomena. Contact angles and surface tensions of the exposed organic film made of 4-CB/4-phenoxyphenol were found to correspond to the hydrophobic/hydrophilic ratios obtained from the FTIR-ATR spectra.

  15. Developmental toxicity and DNA damage from exposure to parking lot runoff retention pond samples in the Japanese medaka (Oryzias latipes).

    Science.gov (United States)

    Colton, Meryl D; Kwok, Kevin W H; Brandon, Jennifer A; Warren, Isaac H; Ryde, Ian T; Cooper, Ellen M; Hinton, David E; Rittschof, Daniel; Meyer, Joel N

    2014-08-01

    Parking lot runoff retention ponds (PLRRP) receive significant chemical input, but the biological effects of parking lot runoff are not well understood. We used the Japanese medaka (Oryzias latipes) as a model to study the toxicity of water and sediment samples from a PLRRP in Morehead City, NC. Medaka exposed in ovo to a dilution series of PLRRP water had increased odds of death before hatching, but not teratogenesis or delayed hatching. Next, we adapted a long-amplicon quantitative PCR (LA-QPCR) assay for DNA damage for use with the Japanese medaka. We employed LA-QPCR to test the hypotheses that PLRRP water and sediments would cause nuclear and mitochondrial DNA damage with and without full-spectrum, natural solar radiation. Fluoranthene with and without natural sunlight was a positive control for phototoxic polycyclic aromatic hydrocarbon-induced DNA damage. Fluoranthene exposure did not result in detectable DNA damage by itself, but in combination with sunlight caused significant DNA damage to both genomes. PLRRP samples caused DNA damage to both genomes, and this was not increased by sunlight exposure, suggesting the DNA damage was unlikely the result of PAH phototoxicity. We report for the first time that PLRRP-associated pollutants cause both nuclear and mitochondrial DNA damage, and that fluoranthene-mediated phototoxicity results in similar levels of damage to the nuclear and mitochondrial genomes. These effects may be especially significant in sensitive marine ecosystems.

  16. Exposure to siRNA-GalNAc Conjugates in Systems of the Standard Test Battery for Genotoxicity.

    Science.gov (United States)

    Janas, Maja M; Jiang, Yongfeng; Duncan, Richard G; Hayes, Antoinette N; Liu, Ju; Kasperkovitz, Pia V; Placke, Michael E; Barros, Scott A

    2016-12-01

    Registration of pharmaceuticals requires an assessment of their genotoxic potential using in vitro and in vivo tests outlined in the International Conference on Harmonisation (ICH) guidance S2(R1). We have evaluated numerous siRNA-N-acetylgalactosamine (GalNAc) conjugates containing phosphorothioate linkages and various combinations of 2'-fluoro and 2'-O-methyl ribose modifications of multiple nucleotides in the ICH battery of assays, all of which have uniformly yielded negative results. To verify these negative genotoxicity results, in this study we confirm test article exposure using toolkit small interfering RNAs (siRNAs) representative of those in the clinic. In the Ames test, the highest uptake of the siRNA-GalNAc conjugates occurred at 1 h postdose in all bacterial strains independent of siRNA sequence or chemistry (up to ∼14,000 siRNA molecules per cell), followed by metabolic degradation of the parent siRNA at 6, 24, and 48 h postdose. siRNA-GalNAc conjugates were internalized by bacteria as assessed by protection from the addition of nucleases to the culture media following uptake and by the requirement of cell lysis for detection of the siRNA. In the in vitro chromosome aberration assay, uptake was observed in Chinese hamster ovary cells (up to ∼5,500 siRNA molecules per cell at 21 h postdose) and in CD3(+) human peripheral blood lymphocytes (up to ∼500 siRNA molecules per cell at 21 h postdose). In the in vivo micronucleus assay in rat bone marrow, exposure to parent siRNA was 100-350 μg of antisense strand per gram of protein at 24 and 48 h postlimit dose of 2 g/kg. Loss of terminal nucleotides was detected in bone marrow by mass spectrometry, indicating exposure to monomer metabolites as well. Negative genotoxicity results were also confirmed in an in vitro double-strand DNA break assay in HeLa and HepG2 cells where exposure was maximized using transfection reagents. Thus negative genotoxicity assay results for si

  17. The diagnostic testing as means of exposure of students' individual peculiarities

    Directory of Open Access Journals (Sweden)

    Ирина Михайловна Жаворонкова

    2011-09-01

    Full Text Available In this article they offer a test methodology of the investigation of students' intellectual and creative abilities. There is a test of different types of tasks verbal not verbal and numerical. A strong attention is paid to the necessity to take into consideration all the individual peculiarities during the learning process.

  18. The Effect of Sunlight in Parenchyma Pith Cells Diameter of Manihot esculenta

    Science.gov (United States)

    Susanti, D.; Aziz, D. N.; Astuti, W.; Nuraeni, E.

    2017-03-01

    Sunlight is one of the factors that effect on the grow of a plant. Manihot esculenta is one of the plants that easily found in Indonesia because its role as staple food. The aim of this research is to know the correlation between sunlight the grow of parenchyma pith cells diameter of Manihot esculenta. Independent variable in this research is sunlight, and dependent variable is the parenchyma pith cells diameter of Manihot esculenta. Data was collected is in qualitative and quantitative form. Qualitative data gotten gained by morphology observation. The parenchyma pith cells of Manihot esculenta that is affected by sunlight in 1310 x 10 Lux, morphologically has hexagon, cell walls thick, solid state, and regular composition. Meanwhile, the parenchyma pith cells that has less sunlight (363 x 10 Lux) has a hexagon shape, thin cell walls thin, soft state, and irregular composition. Qualitative data suported by quantitative data. The size of parenchyma pith cells diameter that is affected by sunlight in 1310 x 10 Lux 96,4 µm. While, the stem parenchyma pith cells diameter empulur that has less sunlight (363 x 10 Lux) is 129,8 µm.

  19. Differences in salivary alpha-amylase and cortisol responsiveness following exposure to electrical stimulation versus the Trier Social Stress Tests.

    Directory of Open Access Journals (Sweden)

    Yoshihiro Maruyama

    Full Text Available BACKGROUND: Cortisol is an essential hormone in the regulation of the stress response along the HPA axis, and salivary cortisol has been used as a measure of free circulating cortisol levels. Recently, salivary alpha-amylase (sAA has also emerged as a novel biomarker for psychosocial stress responsiveness within the sympathetic adrenomedullary (SAM system. PRINCIPAL FINDINGS: We measured sAA and salivary cortisol in healthy volunteers after exposure to the Trier Social Stress Test (TSST and electric stimulation stress. One hundred forty-nine healthy volunteers participated in this study. All subjects were exposed to both the TSST and electric stimulation stress on separate days. We measured sAA and salivary cortisol levels three times immediately before, immediately after, and 20 min after the stress challenge. The State (STAI-S and Trait (STAI-T versions of the Spielberger Anxiety Inventory test and the Profile of Mood State (POMS tests were administered to participants before the electrical stimulation and TSST protocols. We also measured HF, LF and LF/HF Heart Rate Variability ratio immediately after electrical stimulation and TSST exposure. Following TSST exposure or electrical stimulation, sAA levels displayed a rapid increase and recovery, returning to baseline levels 20 min after the stress challenge. Salivary cortisol responses showed a delayed increase, which remained significantly elevated from baseline levels 20 min after the stress challenge. Analyses revealed no differences between men and women with regard to their sAA response to the challenges (TSST or electric stimulations, while we found significantly higher salivary cortisol responses to the TSST in females. We also found that younger subjects tended to display higher sAA activity. Salivary cortisol levels were significantly correlated with the strength of the applied electrical stimulation. CONCLUSIONS: These preliminary results suggest that the HPA axis (but not the SAM

  20. Daytime Cognitive Performance in Response to Sunlight or Fluorescent Light Controlling for Sleep Duration

    Science.gov (United States)

    Ramos, Jhanic; Zamos, Adela; Rao, Rohit; Flynn-Evans, Erin

    2015-01-01

    Light is the primary synchronizer of the human circadian rhythm and also has acute alerting effects. Our study involves and comparing the alertness, performance and sleep of participants in the NASA Ames Sustainability Base, which uses sunlight as its primary light source, to in a traditional office building which uses overhead florescent lighting and varying exposure to natural light. The purpose of this study is to determine whether the use of natural lighting as a primary light source improves daytime cognitive function and promotes nighttime sleep. Participants from the Sustainability Base will be matched by gender and age to individuals working in other NASA buildings. In a prior study we found no differences in performance between those working in the Sustainability Base and those working in other buildings. Unexpectedly, we found that the average sleep duration among participants in both buildings was short, which likely obscured our ability to detect a difference the effect of light exposure on alertness. Given that such sleep deprivation has negative effects on cognitive performance, in this iteration of the study we are asking the participants to maintain a regular schedule with eight hours in bed each night in order to control for the effect of self-selected sleep restriction. Over the course of one week, we will ask the participants to wear actiwatches continuously, complete a psychomotor vigilance task (PVT) and digit symbol substitution task (DSST) three times per day, and keep daily sleepwork diaries. We hope that this study will provide data to support the idea that natural lighting and green architectural design are optimal to enhance healthy nighttime sleep patterns and daytime cognitive performance.

  1. Low-cost extrapolation method for maximal LTE radio base station exposure estimation: test and validation.

    Science.gov (United States)

    Verloock, Leen; Joseph, Wout; Gati, Azeddine; Varsier, Nadège; Flach, Björn; Wiart, Joe; Martens, Luc

    2013-06-01

    An experimental validation of a low-cost method for extrapolation and estimation of the maximal electromagnetic-field exposure from long-term evolution (LTE) radio base station installations are presented. No knowledge on downlink band occupation or service characteristics is required for the low-cost method. The method is applicable in situ. It only requires a basic spectrum analyser with appropriate field probes without the need of expensive dedicated LTE decoders. The method is validated both in laboratory and in situ, for a single-input single-output antenna LTE system and a 2×2 multiple-input multiple-output system, with low deviations in comparison with signals measured using dedicated LTE decoders.

  2. USING STRESS TESTING METHODOLOGY IN EVALUATING BANKING INSTITUTION’S EXPOSURE TO RISK

    OpenAIRE

    Ioan TRENCA; Simona MUTU; Maria-Miruna POCHEA

    2010-01-01

    In order to correctly estimate the unpredictable effects on their transaction portfolios, the banks developed stress testing methods which turned out to be a very important tool in the bank supervision process. Moreover, the supervision authorities started using stress-testing methods for evaluating systemic risk and for determining the adequacy degree of capital in the banking sector. Taking into account the importance of these simulations, the present paper presents methodologies with which...

  3. Hemodynamic retrieval intensity in hippocampus is decreased by pre-exposure to autobiographic test items.

    Science.gov (United States)

    Rekkas, P Vivien; Constable, R Todd

    2006-10-16

    The purpose of this experiment was to assess the effects of probe familiarity, the consequences of having recently retrieved an autobiographic memory (AM), on subsequent recall. This was accomplished by replicating an earlier imaging experiment, using the same participants and memory probes. Subtractions between sessions showed significant pre-exposure effects (i.e., drop in BOLD signal intensity) in the prefrontal cortex, thalamus, cerebellum and other brain structures. Further, region of interest (ROI) analysis illustrated a significant decrease in neural activity in the hippocampus in both conditions. The results are discussed in terms of the pre-scan interview technique, a method applied in AM research to procure personal information. Although invaluable, we emphasize it must be used with caution as it can result in a loss of power. The widespread use of this method in AM research may explain why studies often fail to find evidence of significant responding in the hippocampus in response to memory probes. Alternatively, when activity in the hippocampus is reported, it often fails to differentiate between recent and remote memories. This point is of particular importance to the on-going consolidation debate, as it often centers on a failure to detect an effect in the hippocampus in one or both conditions.

  4. Local cold exposure test with a new arterial photoplethysmographic sensor in healthy controls and patients with secondary Raynaud's phenomenon.

    Science.gov (United States)

    Hahn, M; Hahn, C; Jünger, M; Steins, A; Zuder, D; Klyscz, T; Büchtemann, A; Rassner, G; Blazek, V

    1999-03-01

    Local cold exposure tests are used to diagnose cold-induced vasospastic disorders and to evaluate therapeutic success. We investigated the pulsatile signal detected with a newly developed arterial photoplethysmography (APPG) method and the signal change induced by local cold exposure using a temperature-controlled finger holder, comparing it with laser Doppler flux (red and green laser, rLDF and gLDF) and red blood cell velocity measured in nailfold capillaries (CBV). Ten healthy volunteers and 10 age- and sex-matched patients suffering from Raynaud's phenomenon due to systemic sclerosis were investigated using a moderate cooling temperature of 16 degrees C for 5 min. All signals were recorded simultaneously. The results show a significant reduction of CBV (P pulse wave amplitude; P amplitude could be detected under resting conditions; at cooling temperatures there were also significant differences in CBV and APPG. The temperature-controlled finger holder with its built-in APPG probe appears to be a useful tool for evaluating the effect of local cooling on finger skin perfusion and differentiating between healthy controls and patients with secondary Raynaud's phenomenon due to systemic sclerosis. The gLDF signal was rather weak, limiting its value in cold stress tests. The differences between controls and patients in CBV were somewhat smaller than in previous studies, suggesting the advantage of lower local cooling temperatures, e.g., 12 degrees C.

  5. TRACKING PYRETHROID TOXICITY IN SURFACE WATER SAMPLES: EXPOSURE DYNAMICS AND TOXICITY IDENTIFICATION TOOLS FOR LABORATORY TESTS WITH HYALELLA AZTECA (AMPHIPODA).

    Science.gov (United States)

    Deanovic, Linda A; Stillway, Marie; Hammock, Bruce G; Fong, Stephanie; Werner, Inge

    2017-09-09

    Pyrethroid insecticides are commonly used in pest control and are present at toxic concentrations in surface waters of agricultural and urban areas worldwide. Monitoring is challenging due to their high hydrophobicity and low toxicity thresholds, which often fall below the detection limits of analytical methods. Standard daphnid bioassays used in surface water monitoring are not sensitive enough to protect more susceptible invertebrate species such as the amphipod, Hyalella azteca, and chemical loss during toxicity testing is of concern. In this study, we quantified toxicity loss during storage and testing, using both natural and synthetic water, and present a tool to enhance toxic signal strength for improved sensitivity of H. azteca toxicity tests. The average half-life during storage in LDPE cubitainers at 4°C of five pyrethroids (permethrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, esfenvalerate) and one organophosphate (chlorpyrifos; used as reference) was 1.4 d, and piperonyl butoxide (PBO) proved an effective tool to potentiate toxicity. We conclude that toxicity tests on ambient water samples containing these hydrophobic insecticides are likely to underestimate toxicity present in the field, and mimic short pulse rather than continuous exposures. Where these chemicals are of concern, the addition of PBO during testing can yield valuable information on their presence or absence. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  6. Using equilibrium passive dosing to maintain stable exposure concentrations of triclosan in a 6-week toxicity test

    DEFF Research Database (Denmark)

    Sobek, A.; Ribbenstedt, A.; Mustajärvi, L.

    2015-01-01

    stable exposure concentrations of triclosan (log Kow 4.8) in a 6-week multigeneration test with the benthic copepod Nitocra spinipes. The tests were performed in 10 mL vials casted with 1000 mg of silicone (DC 1-2577). Based on a previous pilot study, three triclosan concentrations were selected...... and tested (15 μg L-1; 30 μg L-1; 60 μg L-1) as well as a control (no triclosan). At test beginning, each vial contained 12 individuals consisting of 3 individuals from four different life stages. The test includes feeding with phytoplankton three times a week, which can lead to declining freely dissolved...... triclosan concentrations. In the present study this was buffered by passive dosing. Water was exchanged every 7th day by transferring the animals from the spend solution into a pre-equilibrated passive dosing glass. During the first two weeks, the copepods grow exponentially and can reach numbers of several...

  7. Can exposure limitations for well-known contact allergens be simplified? An analysis of dose-response patch test data.

    Science.gov (United States)

    Fischer, Louise Arup; Menné, Torkil; Voelund, Aage; Johansen, Jeanne Duus

    2011-06-01

    Allergic contact dermatitis is triggered by chemicals in the environment. Primary prevention is aimed at minimizing the risk of induction, whereas secondary and tertiary prevention are aimed at reducing elicitation. To identify the elicitation doses that will elicit an allergic reaction in 10% of allergic individuals under patch test conditions (ED(10) patch test) for different allergens, and to compare the results with those for different allergens and with animal data indicating sensitizing potency from the literature. The literature was searched for patch test elicitation studies that fulfilled six selected criteria. The elicitation doses were calculated, and fitted dose-response curves were drawn. Sixteen studies with eight different allergens-methylchloroisothiazolinone/ methylisothiazolinone, formaldehyde, nickel, cobalt, chromium, isoeugenol, hydroxyiso hexyl 3-cyclohexene carboxaldehyde, and methyldibromo glutaronitrile-were selected. The median ED(10) value was 0.835 µg/cm(2). The ED(10) patch test values were all within a factor of 7 from the lowest to the highest value, leaving out three outliers. No obvious patterns between the sensitization and elicitation doses for the allergens were found. We found a rather small variation in the ED(10) patch test between the allergens, and no clear relationship between induction potency and elicitation threshold of a range of allergens. This knowledge may stimulate thoughts on introducing a generic approach for limitations in exposure to well-known allergens. © 2011 John Wiley & Sons A/S.

  8. A Stochastic Method for Balancing Item Exposure Rates in Computerized Classification Tests

    Science.gov (United States)

    Huebner, Alan; Li, Zhushan

    2012-01-01

    Computerized classification tests (CCTs) classify examinees into categories such as pass/fail, master/nonmaster, and so on. This article proposes the use of stochastic methods from sequential analysis to address item overexposure, a practical concern in operational CCTs. Item overexposure is traditionally dealt with in CCTs by the Sympson-Hetter…

  9. 77 FR 37717 - Electrical Cable Test Results and Analysis During Fire Exposure

    Science.gov (United States)

    2012-06-22

    ... Commission. ACTION: Draft NUREG; request for comment. SUMMARY: The U.S. Nuclear Regulatory Commission (NRC or the Commission) is making the proposed draft, NUREG-2128, ``Electrical Cable Test Results and Analysis... available in ADAMS) is provided the first time that a document is referenced. The proposed draft...

  10. Concentration-response analysis of differential gene expression in the zebrafish embryotoxicity test following flusilazole exposure

    NARCIS (Netherlands)

    Hermsen, S.A.B.; Pronk, T.; van den Brandhof, E.J.; van der Ven, L.T.M.; Piersma, A.H.

    2012-01-01

    The zebrafish embryotoxicity test (ZET) is considered a promising alternative model in predictive toxicology. Currently, morphological assessment of the embryo is the main readout for this assay. However, implementation of transcriptomics may help to detect more subtle effects, which may increase th

  11. Effect of sunlight on the survival of pathogenic E. coli in freshwater and sea water

    DEFF Research Database (Denmark)

    Surendraraj, Alagarsamy; Farvin, Sabeena; Thampuran, N.

    2011-01-01

    An enteropathogenic group of E. coli are the emerging category of pathogen of public health significance. Several recent pathogenic E. coli outbreaks are associated with drinking water. Aquaculture, the fast emerging food production sector also poses a pathogenic EHEC outbreak risk, as it regularly......) were studied for their survival under sunlight and darkness in fresh water and seawater. Effect of direct sunlight on the viable but nonculturable (VBNC) state of cultures was also studied. The results of the study indicated a distinct pattern between freshwater system and seawater system. Pathogenic E....... coli from different sources showed significantly higher level of destruction under direct sunlight than in complete darkness. A reduction of 1.1 to 5.7 log CFU was seen in fresh water after 90 to 105 min under direct sunlight and only 0.2 to 2 log reduction was observed in complete darkness in 5 to 96...

  12. Assessment of Unsuspected Exposure to Drugs of Abuse in Children from a Mediterranean City by Hair Testing

    Directory of Open Access Journals (Sweden)

    Simona Pichini

    2014-02-01

    Full Text Available Hair testing was used to investigate the prevalence of unsuspected exposure to drugs of abuse in a group of children presenting to an urban paediatric emergency department without suggestive signs or symptoms. Hair samples were obtained from 114 children between 24 months and 10 years of age attending the emergency room of Hospital del Mar in Barcelona, Spain. Hair samples from the accompanying parent were also collected. The samples were analyzed for the presence of opiates, cocaine, amphetamines, and cannabinoids by ultra-performance liquid chromatography-tandem mass spectrometry. Parental sociodemographics and possible drug of abuse history were recorded. Hair samples from twenty-three children (20.1% were positive for cocaine (concentration range 0.15–3.81 ng/mg hair, those of thirteen children (11.4% to cannabinoids (D9-THC concentration range 0.05–0.54 ng/mg hair, with four samples positive to codeine (0.1–0.25 ng/mg hair, one positive for 2.09 ng methadone per mg hair and one to 6-MAM (0.42 ng/mg hair and morphine (0. 15 ng/mg hair . In 69.5 and 69.2% of the positive cocaine and cannabinoids cases respectively, drugs was also found in the hair of accompanying parent. Parental sociodemographics were not associated with children exposure to drugs of abuse. However, the behavioural patterns with potential harmful effects for the child’s health (e.g., tobacco smoking, cannabis, benzodiazepines and/or antidepressants use were significantly higher in the parents of exposed children. In the light of the obtained results (28% overall children exposure to drugs of abuse and in agreement with 2009 unsuspected 23% cocaine exposure in pre-school children from the same hospital, we support general hair screening to disclose exposure to drugs of abuse in children from risky environments to provide the basis for specific social and health interventions.

  13. Sunlight inactivation of faecal bacteria in waste stabilization ponds in a Sahelian region (Ouagadougou, Burkina Faso)

    Energy Technology Data Exchange (ETDEWEB)

    Maiga, Y.; Denyigba, K.; Wethe, J.; Ouattara, A. S.

    2009-07-01

    Waste stabilization ponds (WSPs) are an appropriate sewage treatment system for developing countries in Sahelian regions. Several studies on wastewater treatment in WSPs have shown that solar radiation is a major factor in the inactivation of faecal indicator, and that sunlight acts on interaction with other factors including dissolved oxygen (DO) and pH. However, the inactivation by sunlight is limited by the reduction of light penetration in ponds. (Author)

  14. Skin prick test predictive value on the outcome of a first known egg exposure in milk-allergic children.

    Science.gov (United States)

    Diéguez, M C; Cerecedo, I; Muriel, A; Zamora, J; Sánchez-Cano, M; De la Hoz, B

    2008-06-01

    Children with milk allergy have higher incidence of other food allergies, especially egg allergy. The objective of this study was to ascertain the accuracy of the prick test in children with IgE-mediated milk allergy for diagnosing egg allergy. Children under the age of 1 yr who came consecutively to Allergy Department 2003-05, and were diagnosed with IgE-mediated milk allergy were selected for this study. Egg introduction was completely avoided until the age of 14 months when clinical history, skin prick tests (SPT), specific-IgE antibodies determination and egg challenge test were performed. One hundred and four milk-allergic children were included. At least one positive prick test to any egg allergen was found in 65 out of the 104 (62.5%). Thirty-eight (36.5%) were allergic to egg proteins as well. Prick tests with egg white and ovomucoid (OVM) had the best diagnostic performances showing the largest areas under the receiver operating characteristic curve. The optimal diagnosis cut-off point was 6 mm for egg white and 5 mm for OVM. The positive likelihood ratios for these cut-off points were: 2.95 (95% CI: 1.74-4.99) for egg white prick test, and 20 (95% CI: 2.9-143.7) for OVM prick test. Children with specific IgE-mediated cow's milk allergy must be closely followed as a risk group for egg allergy. Early diagnosis is necessary and the SPT has shown itself to be a very useful tool for diagnosing immediate IgE reactions to egg on first known exposure.

  15. Effects of test media on reproduction in Potamopyrgus antipodarum and of pre-exposure population densities on sensitivity to cadmium in a reproduction test.

    Science.gov (United States)

    Sieratowicz, Agnes; Schulte-Oehlmann, Ulrike; Wigh, Adriana; Oehlmann, Jörg

    2013-01-01

    Molluscan species can be affected by various anthropogenic substances. Yet, these effects are disregarded in chemical risk assessment as molluscs are unrepresented in standard OECD guidelines. The project "validation of a mollusc reproduction test" (Federal Environment Agency, code 371165417) deals with the development of a test method with the mudsnail Potamopyrgus antipodarum for OECD purposes. In this context, the influence on reproduction of both, different media and varying snail density, has been observed in independent experiments. Further, the impact of density on the outcome of subsequent cadmium (Cd) toxicity in a test has been investigated to refine the existing methodology. First, adult snails were kept in different test media for 12 weeks. Second, snail density was increased for 4 weeks to induce stress. Snails from each density scenario were used for another 4 weeks in a reproduction test at an equal density with 12 μg Cd/L, respectively. Significant differences in reproduction between medium groups were noted after 4 and 8, but not 12, weeks. Further, reproduction was significantly altered by snail density in the beakers but after subsequent 4 weeks at a constant density, no differences were observed between control groups. Cd reduced reproduction and this effect increased with snail density in the pre-exposure period, demonstrating that a previous stress factor may result in increased sensitivity to chemicals and underlines the need for more standardized breeding conditions to minimize effect variations. Based on the outcome of this study, an acclimatization period of 12 weeks must be guaranteed for specimens transferred to another medium. Further, 4 weeks of acclimatization are necessary after density stress. An additional 12 weeks density experiment showed that medium volume in each replicate can be decreased by half to save on chemicals, water and space during tests.

  16. Environmental Exposure and Accelerated Testing of Rubber-to-Metal Vulcanized-Bonded Assemblies

    Science.gov (United States)

    1975-08-01

    53 percent for the unstressed and 66 percent for the stressed specimens. 4 A Z! - ~ - The attempt to improve the hydroltyic stability of vulcanized...vulcanized bonds show no loss in bond strength after two years otdoors at Rock Island * or after 14 days in the hydrolytic stability test in which...METAL Part b Weit COMPOUNDNG INGREDIENTS E57 MU__ N200 Nordel i04o0 ( EPDm ) 100 Stereon 700 (SBR) 100 Neoprene WD (CR) 100 Paracril AJ (NBR) 85 Paracril B

  17. Environmental Exposure and Accelerated Testing of Rubber-to-Metal Vulcanized Bonded Assemblies

    Science.gov (United States)

    1974-11-01

    subjected to the hydrolytic stability test or when exposed to the severe climatic conditions at Panama. EPDM and nitrile vulcanized bonded-specimens...butadiene acrylonitrile rubber bonded Sassembliesshowed a severe loes of 100 percent in bond strength; the EPDM bond.ed assemblies shcwed a 40 percent lose...02 ~ 4 -0 04 0: 00 V 4 o ~no 󈧄 0 80 EPDM Spgcimens aged up to 450°F are .shown .in Table 7. At 3000F, all - bonding agents provided good retention

  18. Simulation tests to assess occupational exposure to airborne asbestos from artificially weathered asphalt-based roofing products.

    Science.gov (United States)

    Sheehan, Patrick; Mowat, Fionna; Weidling, Ryan; Floyd, Mark

    2010-11-01

    Historically, asbestos-containing roof cements and coatings were widely used for patching and repairing leaks. Although fiber releases from these materials when newly applied have been studied, there are virtually no useful data on airborne asbestos fiber concentrations associated with the repair or removal of weathered roof coatings and cements, as most studies involve complete tear-out of old roofs, rather than only limited removal of the roof coating or cement during a repair job. This study was undertaken to estimate potential chrysotile asbestos fiber exposures specific to these types of roofing products following artificially enhanced weathering. Roof panels coated with plastic roof cement and fibered roof coating were subjected to intense solar radiation and daily simulated precipitation events for 1 year and then scraped to remove the weathered materials to assess chrysotile fiber release and potential worker exposures. Analysis of measured fiber concentrations for hand scraping of the weathered products showed 8-h time-weighted average concentrations that were well below the current Occupational Safety and Health Administration permissible exposure limit for asbestos. There was, however, visibly more dust and a few more fibers collected during the hand scraping of weathered products compared to the cured products previously tested. There was a notable difference between fibers released from weathered and cured roofing products. In weathered samples, a large fraction of chrysotile fibers contained low concentrations of or essentially no magnesium and did not meet the spectral, mineralogical, or morphological definitions of chrysotile asbestos. The extent of magnesium leaching from chrysotile fibers is of interest because several researchers have reported that magnesium-depleted chrysotile fibers are less toxic and produce fewer mesothelial tumors in animal studies than normal chrysotile fibers.

  19. Sunlight and the 10-year incidence of age-related maculopathy: the Beaver Dam Eye Study.

    Science.gov (United States)

    Tomany, Sandra C; Cruickshanks, Karen J; Klein, Ronald; Klein, Barbara E K; Knudtson, Michael D

    2004-05-01

    To examine the association of sunlight exposure and indicators of sun sensitivity with the 10-year incidence of age-related maculopathy (ARM). Population-based cohort study. We included persons aged 43 to 86 years at the baseline examination from 1988 to 1990, living in Beaver Dam, Wis, of whom 3684 persons underwent 5-year follow-up and 2764 underwent 10-year follow-up. Data on sun exposure and indicators of sun sensitivity were obtained from a standardized questionnaire administered at baseline and/or follow-up. We determined ARM status by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System. Incidence and progression of ARM. While controlling for age and sex, we found that participants exposed to the summer sun for more than 5 hours a day during their teens, in their 30s, and at the baseline examination were at a higher risk of developing increased retinal pigment (risk ratio [RR], 2.99; 95% confidence interval [CI], 1.18-7.60; P =.02) and early ARM (RR, 2.20; 95% CI, 1.02-4.73; P =.04) [corrected] by 10 years than those exposed less than 2 hours per day during the same periods. In participants reporting the highest summer sun exposure levels in their teens and 30s, the use of hats and sunglasses at least half the time during the same periods was associated with a decreased risk of developing soft indistinct drusen (RR, 0.55; 95% CI, 0.33-0.90; P =.02) and retinal pigment epithelial depigmentation (RR, 0.51; 95% CI, 0.29-0.91; P =.02). Participants who experienced more than 10 severe sunburns during their youth were more likely than those who experienced 1 or no burn to develop drusen with a 250-microm diameter or larger (RR, 2.52; 95% CI, 1.29-4.94 [corrected] P =.01) by the 10-year examination. No relationships were found between UV-B exposure, winter leisure time spent outdoors, skin sun sensitivity, or number of bad sunburns experienced by the time of the baseline examination and the 10-year incidence and

  20. EVALUATING THE EFFECTS OF FLY ASH EXPOSURE ON FISH EARLY LIFE STAGES: FATHEAD MINNOW EMBRYO-LARVAL TESTS

    Energy Technology Data Exchange (ETDEWEB)

    Greeley Jr, Mark Stephen [ORNL; Elmore, Logan R [ORNL; McCracken, Kitty [ORNL

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash in an 84-acre complex of the Tennessee Valley Authority's (TVA) Kingston Steam Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits extended as far as 4 miles upstream (Emory River mile 6) of the Plant, and some ash was carried as far downstream as Tennessee River mile 564 ({approx}4 miles downstream of the Tennessee River confluence with the Clinch River). A byproduct of coal burning power plants, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be toxic to biological systems. The effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to be the effects of specific ash constituents, especially selenium, on fish early life stages. Uptake by adult female fish of fly ash constituents through the food chain and subsequent maternal transfer of contaminants to the developing eggs is thought to be the primary route of selenium exposure to larval fish (Woock and others 1987, Coyle and others 1993, Lemly 1999, Moscatello and others 2006), but direct contact of the fertilized eggs and developing embryos to ash constituents in river water and sediments is also a potential risk factor (Woock and others 1987, Coyle and others 1993, Jezierska and others 2009). To address the risk of fly ash from the Kingston spill to the reproductive health of downstream fish populations, ORNL has undertaken a series of studies in collaboration with TVA including: (1) a field study of the bioaccumulation of fly ash constituents in fish ovaries and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill; (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (reported in the

  1. Dissolved organic matter degradation by sunlight coagulates organo-mineral colloids and produces low-molecular weight fraction of metals in boreal humic waters

    Science.gov (United States)

    Oleinikova, Olga V.; Drozdova, Olga Yu.; Lapitskiy, Sergey A.; Demin, Vladimir V.; Bychkov, Andrey Yu.; Pokrovsky, Oleg S.

    2017-08-01

    Photochemical degradation of dissolved organic matter (DOM) is recognized as the major driver of CO2 emission to the atmosphere from the inland waters of high latitudes. In contrast to numerous studies of photo-induced DOM transformation, the behavior of trace element (TE) during photodegradation of boreal DOM remains virtually unknown. Towards a better understanding of concentration, size fractionation and speciation change of DOM and TE in boreal waters subjected to solar radiation, we conducted on-site photo-degradation experiments in stream and bog water collected from a pristine zone of the Northern Karelia (Russian subarctic). The removal of Fe and Al occurred only in the bog water (90% and 50% respectively, over 5 days of reaction), whereas no detectable decrease of dissolved (exposure to sunlight: Al, P, Ti, V, Cr, As, Y, Zr, REEs, Hf, Th, Pb and U. The second group of elements (Li, B, Mg, Ca, Sr, Ba, Na, K, Rb, Si, Mn, Ni, Cu, Co, Cd, Sb) was indifferent to photodegradation of DOM and exhibited a non-systematic variation (±10-15% from the control) of sunlight exposure. The bog water insolation yielded a factor of 3 ± 1 increase of low molecular weight (LMW sunlight exposure compared to the dark control. The LMW< 1 kDa fraction was preferentially enriched in Fe, Al, Ca, Mg and other divalent metals relative to Corg. The climate warming leading to water temperature rise in the boreal zone will intensify the Fe and Al hydroxide coagulation while increasing the production of LMW organic ligands and free metals and metal - organic complexes.

  2. Short communication: artificial ultraviolet B light exposure increases vitamin D levels in cow plasma and milk.

    Science.gov (United States)

    Jakobsen, Jette; Jensen, Søren Krogh; Hymøller, Lone; Andersen, Elisabeth Wreford; Kaas, Poul; Burild, Anders; Jäpelt, Rie Bak

    2015-09-01

    The number of dairy cows without access to pasture or sunlight is increasing; therefore, the content of vitamin D in dairy products is decreasing. Ultimately, declining vitamin D levels in dairy products will mean that dairy products are a negligible source of natural vitamin D for humans. We tested the ability of a specially designed UVB lamp to enhance the vitamin D3 content in milk from dairy cows housed indoors. This study included 16 cows divided into 4 groups. Each group was exposed daily to artificial UVB light simulating 1, 2, 3, or 4 h of summer sun at 56°N for 24 d, and the group with simulated exposure to 2 h of summer sun daily continued to be monitored for 73 d. We found a significant increase in 25-hydroxyvitamin D3 (25OHD3) levels in plasma as well as vitamin D3 and 25OHD3 levels in milk after daily exposure for 24 d in all treatment groups. Extending daily exposure to artificial UVB light to 73 d did not lead to an increase of vitamin D3 or 25OHD3 level in the milk. In conclusion, the change in production facilities for dairy cows providing cows with no access to pasture and sunlight causes a decrease of vitamin D levels in dairy products. This decrease may be prevented by exposing cows to artificial UVB light in the stable.

  3. Long-term exposure to a ‘safe’ dose of bisphenol A reduced protein acetylation in adult rat testes

    Science.gov (United States)

    Chen, Zhuo; Zuo, Xuezhi; He, Dongliang; Ding, Shibin; Xu, Fangyi; Yang, Huiqin; Jin, Xin; Fan, Ying; Ying, Li; Tian, Chong; Ying, Chenjiang

    2017-01-01

    Bisphenol A (BPA), a typical environmental endocrine-disrupting chemical, induces epigenetic inheritance. Whether histone acetylation plays a role in these effects of BPA is largely unknown. Here, we investigated histone acetylation in male rats after long-term exposure to a ‘safe’ dose of BPA. Twenty adult male rats received either BPA (50 μg/kg·bw/day) or a vehicle diet for 35 weeks. Decreased protein lysine-acetylation levels at approximately ~17 kDa and ~25 kDa, as well as decreased histone acetylation of H3K9, H3K27 and H4K12, were detected by Western blot analysis of testes from the treated rats compared with controls. Additionally, increased protein expression of deacetylase Sirt1 and reduced binding of Sirt1, together with increased binding of estrogen receptor β (ERβ) to caveolin-1 (Cav-1), a structural protein component of caveolar membranes, were detected in treated rats compared with controls. Moreover, decreased acetylation of Cav-1 was observed in the treated rats for the first time. Our study showed that long-term exposure to a ‘safe’ dose of BPA reduces histone acetylation in the male reproductive system, which may be related to the phenotypic paternal-to-offspring transmission observed in our previous study. The evidence also suggested that these epigenetic effects may be meditated by Sirt1 via competition with ERβ for binding to Cav-1.

  4. Long-term exposure to a ‘safe’ dose of bisphenol A reduced protein acetylation in adult rat testes

    Science.gov (United States)

    Chen, Zhuo; Zuo, Xuezhi; He, Dongliang; Ding, Shibin; Xu, Fangyi; Yang, Huiqin; Jin, Xin; Fan, Ying; Ying, Li; Tian, Chong; Ying, Chenjiang

    2017-01-01

    Bisphenol A (BPA), a typical environmental endocrine-disrupting chemical, induces epigenetic inheritance. Whether histone acetylation plays a role in these effects of BPA is largely unknown. Here, we investigated histone acetylation in male rats after long-term exposure to a ‘safe’ dose of BPA. Twenty adult male rats received either BPA (50 μg/kg·bw/day) or a vehicle diet for 35 weeks. Decreased protein lysine-acetylation levels at approximately ~17 kDa and ~25 kDa, as well as decreased histone acetylation of H3K9, H3K27 and H4K12, were detected by Western blot analysis of testes from the treated rats compared with controls. Additionally, increased protein expression of deacetylase Sirt1 and reduced binding of Sirt1, together with increased binding of estrogen receptor β (ERβ) to caveolin-1 (Cav-1), a structural protein component of caveolar membranes, were detected in treated rats compared with controls. Moreover, decreased acetylation of Cav-1 was observed in the treated rats for the first time. Our study showed that long-term exposure to a ‘safe’ dose of BPA reduces histone acetylation in the male reproductive system, which may be related to the phenotypic paternal-to-offspring transmission observed in our previous study. The evidence also suggested that these epigenetic effects may be meditated by Sirt1 via competition with ERβ for binding to Cav-1. PMID:28067316

  5. A microfluidic device with multi-valves system to enable several simultaneous exposure tests on Caenorhabditis elegans

    Science.gov (United States)

    Jung, Jaehoon; Nakajima, Masahiro; Masaru, Takeuchi; Huang, Qiang; Fukuda, Toshio

    2014-03-01

    In this paper, we report on a microfluidic device with a multi-valve system to conduct several exposure tests on Caenorhabditis elegans (C. elegans) simultaneously. It has pneumatic valves and no-moving-parts (NMP) valves. An NMP valve is incorporated with a chamber and enables the unidirectional movement of C. elegans in the chamber; once worms are loaded into the chamber, they cannot exit, regardless of the flow direction. To demonstrate the ability of the NMP valve to handle worms, we made a microfluidic device with three chambers. Each chamber was used to expose worms to Cd and Cu solutions, and K-medium. A pair of electrodes was installed in the device and the capacitance in-between the electrode was measured. When a C. elegans passed through the electrodes, the capacitance was changed. The capacitance change was proportional to the body volume of the worm, thus the body volume change by the heavy metal exposure was measured in the device. Thirty worms were divided into three groups and exposed to each solution. We confirmed that the different solutions induced differences in the capacitance changes for each group. These results indicate that our device is a viable method for simultaneously analyzing the effect of multiple stimuli on C. elegans.

  6. Evaluating the suitability of Hydrobia ulvae as a test species for sediment metal toxicity testing applying a tissue residue approach to metal mixtures in laboratory and field exposures.

    Science.gov (United States)

    Campana, Olivia; Rodríguez, Antonio; Blasco, Julián

    2013-05-01

    A major weakness in evaluating the suitability of a biomonitor organism is the poor ability to predict the variability of the bioavailability of metals from measured environmental concentrations. In this study, the intertidal gastropod Hydrobia ulvae was used to evaluate its suitability as a test organism for assessing sediment metal toxicity. Toxicity tests were run with sediments spiked with copper, cadmium and zinc applied both as single metal and as a mixture to investigate toxicological interactions evaluating different lethal and sublethal effects. Dose-response relationships were constructed based both on tissue residue approach and particulate metal concentrations. Because metal-spiked sediments used in routine toxicity tests often do not exhibit the same adsorption/desorption kinetics as the natural sediments, the laboratory results were compared to 10-d bioassays conducted with natural field sediments collected from the Guadalete estuary (SW Spain). Highly significant correlations between tissue residue concentrations and particulate metal concentrations were found for all metal-spiked or field-collected and demonstrated that: (i) H. ulvae readily accumulated copper and cadmium in response to contamination and (ii) dietary uptake was determined to be the most significant route of metal exposure. The comparison of the modeled tissue residue-response curve developed from the mixture tests was in good agreement with the results from the bioassay conducted with field sediments and strongly demonstrated that H. ulvae is also a suitable test organism for assessing copper sediment toxicity. In contrast, the dose-response curve expressed as a function of total particulate metal concentrations would fail in predicting effect, erroneously assessing higher metal toxicity.

  7. Pilot study testing a European human biomonitoring framework for biomarkers of chemical exposure in children and their mothers

    DEFF Research Database (Denmark)

    Exley, Karen; Aerts, Dominique; Biot, Pierre;

    2015-01-01

    Exposure to a number of environmental chemicals in UK mothers and children has been assessed as part of the European biomonitoring pilot study, Demonstration of a Study to Coordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES). For the European-funded project, 17 countries...... tested the biomonitoring guidelines and protocols developed by COPHES. The results from the pilot study in the UK are presented; 21 school children aged 6-11 years old and their mothers provided hair samples to measure mercury and urine samples, to measure cadmium, cotinine and several phthalate...... on environment, health and lifestyle. Mercury in hair was higher in children who reported frequent consumption of fish (geometric mean 0.35 μg/g) compared to those that ate fish less frequently (0.13 μg/g, p = 0.002). Cadmium accumulates with age as demonstrated by higher levels of urinary cadmium in the mothers...

  8. Child exposure to serious life events, COMT, and aggression: Testing differential susceptibility theory.

    Science.gov (United States)

    Hygen, Beate Wold; Belsky, Jay; Stenseng, Frode; Lydersen, Stian; Guzey, Ismail Cuneyt; Wichstrøm, Lars

    2015-08-01

    Both genetic and environmental factors contribute to individual differences in aggression. Catechol-O-methyltransferase Val158Met (COMT), a common, functional polymorphism, has been implicated in aggression and aggression traits, as have childhood experiences of adversity. It is unknown whether these effects are additive or interactional and, in the case of interaction, whether they conform to a diathesis-stress or differential susceptibility model. We examined Gene × Environment interactions between COMT and serious life events on measures of childhood aggression and contrasted these 2 models. The sample was composed of community children (N = 704); 355 were boys, and the mean age was 54.8 months (SD = 3.0). The children were genotyped for COMT rs4680 and assessed for serious life events and by teacher-rated aggression. Regression analysis showed no main effects of COMT and serious life events on aggression. However, a significant interactive effect of childhood serious life events and COMT genotype was observed: Children who had faced many serious life events and were Val homozygotes exhibited more aggression (p = .02) than did their Met-carrying counterparts. Notably, in the absence of serious life events, Val homozygotes displayed significantly lower aggression scores than did Met carriers (p = .03). When tested, this constellation of findings conformed to the differential susceptibility hypothesis: In this case, Val homozygotes are more malleable to the effect of serious life events on aggression and not simply more vulnerable to the negative effect of having experienced many serious life events.

  9. Photocatalytic degradation of phenol by iodine doped tin oxide nanoparticles under UV and sunlight irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hamdi, Abdullah M.; Sillanpää, Mika [Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Dutta, Joydeep, E-mail: dutta@squ.edu.om [Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 17, 123 Al-Khoudh (Oman)

    2015-01-05

    Highlights: • A sol–gel method used to synthesize tin oxide nanoparticles. • Nanoparticles of tin oxide doped with different iodine concentrations. • Degradation studies carried up with UV–vis, TOC, HPLC and GC instruments. • 1% iodine doped tin dioxide showed maximum photodegradation efficiency. - Abstract: Iodine doped tin oxide (SnO{sub 2}:I) nanoparticles were prepared by sol–gel synthesis and their photocatalytic activities with phenol as a test contaminant were studied. In the presence of the catalysts, phenol degradation under direct sunlight was comparable to what was achieved under laboratory conditions. Photocatalytic oxidation reactions were studied by varying the catalyst loading, light intensity, illumination time, pH of the reactant and phenol concentration. Upon UV irradiation in the presence of SnO{sub 2}:I nanoparticles, phenol degrades very rapidly within 30 min, forming carboxylic acid which turns the solution acidic. Phenol degradation rate with 1% iodine doped SnO{sub 2} nanoparticles is at least an order of magnitude higher compared to the degradation achieved through undoped SnO{sub 2} nanoparticles under similar illumination conditions.

  10. Photocatalytic degradation of five sulfonylurea herbicides in aqueous semiconductor suspensions under natural sunlight.

    Science.gov (United States)

    Fenoll, José; Hellín, Pilar; Flores, Pilar; Martínez, Carmen María; Navarro, Simón

    2012-05-01

    In the present study, the photocatalytic degradation of five sulfonylurea herbicides (chlorsulfuron, flazasulfuron, nicosulfuron, sulfosulfuron and triasulfuron) has been investigated in aqueous suspensions of zinc oxide (ZnO), tungsten (VI) oxide (WO(3)), tin (IV) oxide (SnO(2)) and zinc sulfide (ZnS) at pilot plant scale under natural sunlight. Photocatalytic experiments, especially those involving ZnO photocatalysis, showed that the addition of semiconductors in tandem with the oxidant (Na(2)S(2)O(8)) strongly enhances the degradation rate of the herbicides in comparisons carried out with photolytic tests. The degradation of the herbicides follows a first order kinetics according to the Langmuir-Hinshelwood model. In our conditions, the amount of time required for 50% of the initial pesticide concentration to dissipate (t(½)) ranged from 8 to 27 min (t(30W)=0.3-1.2 min) for sulfosulfuron and chlorsulfuron, respectively in the ZnO/Na(2)S(2)O(8) system. None of the studied herbicides was found after 120 min of illumination (except chlorsulfuron, 0.2 μg L(-1)).

  11. Field tests on human tolerance to (LNG) fire radiant heat exposure, and attenuation effects of clothing and other objects.

    Science.gov (United States)

    Raj, Phani K

    2008-09-15

    A series of field tests exposing mannequins clothed with civilian clothing to a 3m x 3m square liquefied natural gas (LNG) pool fire was conducted. Both single layer clothing and double layer clothing were used. The radiant heat flux incident outside the clothing and incident on the skin covered by clothing were measured using wide-angle radiometers, for durations of 100-200 s (per test). The levels of heat flux incident on the clothing were close to 5 kW/m(2). The magnitude of the radiant heat attenuation factor (AF) across the thickness was determined. AF varies between 2 and higher for cotton and polyester clothing (thickness 0.286-1.347 mm); AF value of 6 was measured for 1.347 mm thickness. Single sheet newspaper held about 5 cm in front of mannequins and exposed to incident flux of 5 kW/m(2) resulted in AF of 5, and AF of 8 with double sheets. AF decreases linearly with increasing heat flux values and linearly increases with thickness. The author exposed himself, in normal civilian clothing (of full sleeve cotton/polyester shirt and jean pants), to radiant heat from a LNG fire. The exposure was for several tens of seconds to heat flux levels ranging from 3.5 kW/m(2) to 5(+) kW/m(2) (exposure times from 25s to 97 s at average heat flux values in the 4 kW/m(2) and 5 kW/m(2)range). Occasionally, he was exposed to (as high as) 7 kW/m(2) for durations of several seconds. He did not suffer any unbearable or even severe pain nor did he experience blisters or burns or any other injury on the unprotected skin of his body. The incident heat fluxes on the author were measured by a hand-held radiometer (with digital display) as well as by strapped on wide-angle radiometers connected to a computer. He could withstand the US regulatory criterion of 5 kW/m(2) (for 30 s) without suffering any damage or burns. Temperature measured on author's skin covered by clothing did not rise above the normal body temperature even after 200 s of exposure to 4 kW/m(2) average heat flux.

  12. Sunlight Triggers Cutaneous Lupus through a Colony Stimulating Factor-1 (CSF-1) Dependent Mechanism in MRL-Faslpr mice

    Science.gov (United States)

    Menke, Julia; Hsu, Mei-Yu; Byrne, Katelyn T.; Lucas, Julie A.; Rabacal, Whitney A.; Croker, Byron P.; Zong, Xiao-Hua; Stanley, E. Richard; Kelley, Vicki R.

    2008-01-01

    Sunlight (UVB) triggers cutaneous (CLE) and systemic lupus through an unknown mechanism. We tested the hypothesis that UVB triggers CLE through a CSF-1-dependent, macrophage (Mø) -mediated mechanism in MRL-Faslpr mice. By constructing mutant MRL-Faslpr strains expressing varying levels of CSF-1 (high, intermediate, none), and use of an ex-vivo gene transfer to deliver CSF-1 intra-dermally, we determined that CSF-1 induces CLE in lupus-susceptible, MRL-Faslpr mice, but not in lupus-resistant, BALB/c mice. Notably, UVB incites an increase in Mø, apoptosis in the skin and CLE in MRL-Faslpr, but not in CSF-1-deficient MRL-Faslpr mice. Furthermore, UVB did not induce CLE in BALB/c mice. Probing further, UVB stimulates CSF-1 expression by keratinocytes leading to recruitment and activation of Mø that, in turn, release mediators, which induce apoptosis in keratinocytes. Thus, sunlight triggers a CSF-1-dependent, Mø-mediated destructive inflammation in the skin leading to CLE in lupus-susceptible MRL-Faslpr, but not lupus-resistant BALB/c mice. Taken together, we envision CSF-1 as the “match” and lupus-susceptibility as the “tinder” leading to CLE. PMID:18981160

  13. Cognitive disparities, lead plumbing, and water chemistry: prior exposure to water-borne lead and intelligence test scores among World War Two U.S. Army enlistees.

    Science.gov (United States)

    Ferrie, Joseph P; Rolf, Karen; Troesken, Werner

    2012-01-01

    Higher prior exposure to water-borne lead among male World War Two U.S. Army enlistees was associated with lower intelligence test scores. Exposure was proxied by urban residence and the water pH levels of the cities where enlistees lived in 1930. Army General Classification Test scores were six points lower (nearly 1/3 standard deviation) where pH was 6 (so the water lead concentration for a given amount of lead piping was higher) than where pH was 7 (so the concentration was lower). This difference rose with time exposed. At this time, the dangers of exposure to lead in water were not widely known and lead was ubiquitous in water systems, so these results are not likely the effect of individuals selecting into locations with different levels of exposure. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. RADIATION DOSES AND CANCER RISKS IN THE MARSHALL ISLANDS ASSOCIATED WITH EXPOSURE TO RADIOACTIVE FALLOUT FROM BIKINI AND ENEWETAK NUCLEAR WEAPONS TESTS: SUMMARY

    OpenAIRE

    Simon, Steven L.; Bouville, André; Land, Charles E.; Beck, Harold L.

    2010-01-01

    Nuclear weapons testing conducted at Bikini and Enewetak Atolls during 1946–1958 resulted in exposures of the resident population of the present-day Republic of the Marshall Islands to radioactive fallout. This paper summarizes the results of a thorough and systematic reconstruction of radiation doses to that population, by year, age at exposure, and atoll of residence, and the related cancer risks. Detailed methods and results are presented in a series of companion papers in this volume. Fro...

  15. THE RISKS OF SUNLIGHTING CLASSROOMS. An appraisal method to assess the severity of discomfort due to sunlight penetration in classrooms. Site of study: Primary school classrooms in Constantine (ALGERIA

    Directory of Open Access Journals (Sweden)

    D SAFFIDINE-ROUAG

    2001-12-01

    Full Text Available The westerly orientations for a large number of primary school classrooms in Constantine involved a serious environmental problem provoked by uncontrolled sunlight. Under such circumstances the schoolchildren had no choice than keep sitting under incident sunlight while performing their various school tasks.  Evidence of the severity of discomfort experienced by those pupils was investigated using observational methods. The results allowed to reach substantial conclusions about the risks of sunlighting classrooms.

  16. Influence of manure age and sunlight on the community structure of cattle fecal bacteria as revealed by Illumina sequencing

    Science.gov (United States)

    Wong, K.; Shaw, T. I.; Oladeinde, A.; Molina, M.

    2013-12-01

    Fecal pollution of environmental waters is a major concern for the general public because exposure to fecal-associated pathogens can have severe impacts on human health. Stream and river impairment due to fecal pollution is largely the result of agricultural activities in the United States. In the last few years, numerous metagenomic studies utilized next generation sequencing to develop microbial community profiles by massively sequencing the 16sRNA hypervariable region. This technology supports the application of water quality assessment such as pathogen detection and fecal source tracking. The bacteria communities of samples in these studies were determined when they were freshly collected; therefore, little is known about how feces age or how environmental stress influences the microbial ecology of fecal materials. In this study we monitored bacteria community changes in cattle feces for 57 days after excretion (day 0, 2, 4 8, 15, 22, 29, 43, 57) by sequencing the 16s variable region 4, using Illumnia MiSeq. Twelve cattle feces were studied; half of the samples were directly exposed to sunlight (unshaded) and half were shaded. Results indicate that the relative abundance (RA) profile in both shaded and unshaded samples rapidly changed from day 0 to 15, but stabilized from day 22 to 57. Firmcutes were the most abundant phylum (~40%) at day 0, but were reduced to bacteria community in the natural environment. According to the rarefaction curve analysis, richness of bacteria diversity in feces decreased as time progressed. Some pathogens such as Campylobacter were detected only at the beginning, meaning they substantially decayed during the course of our study. Overall, this study indicated: (1) sunlight can influence the community structure and (2) after excretion the fecal bacteria diversity can be significantly changed over time. Future studies should therefore use not only the microbial signature of fresh but also moderately aged fecal samples to develop more

  17. Synthesis, Characterization, and Sunlight Mediated Photocatalytic Activity of CuO Coated ZnO for the Removal of Nitrophenols.

    Science.gov (United States)

    Qamar, M Tariq; Aslam, M; Ismail, Iqbal M I; Salah, Numan; Hameed, A

    2015-04-29

    CuO@ZnO core-shell catalysts, coated by varying the CuO layer density ranging from 0.5% to 10%, were synthesized with the aim to enhance the photocatalytic activity of ZnO in sunlight and control its photocorrosion. Initially, the Cu(2+) ions were impregnated on presynthesized ZnO by wet impregnation and finally converted to CuO layers by calcination. The optical and structural characterization of the synthesized powders was performed by DRS, PL, Raman spectroscopy, and XRD analysis, respectively. The homogeneity of the coated layers was explored by FESEM. The photocatalytic activity of CuO coated ZnO was investigated for the degradation of mononitrophenols (2-, 3-, and 4-nitrophenol) and dinitrophenols (2,4-, 2,5-, and 2,6-dinitrophenol) in the exposure of the complete spectrum and visible region (420-800 nm) of sunlight. The effect of the increasing density coated layers of CuO on photocatalytic activity was evaluated for the degradation of 4-NP. Compared to pristine ZnO, a substantial increase in the degradation/mineralization ability was observable for the catalysts coated with 0.5% and 1% CuO, whereas a detrimental effect was noticed for higher coating density. Prior to photocatalytic studies, as evaluated by cyclic voltammetry (CV), compared to pure ZnO, a significant suppression of photocorrosion was noticed, under illumination, for catalysts coated with lower CuO coating. The progress of the photocatalytic degradation process was monitored by HPLC while the mineralization ability of the synthesized catalysts was estimated by TOC. The estimation of the released ions and their further interaction with the excited states and the reactive oxygen was monitored by ion chromatography (IC).

  18. Nanoparticle-Based Immunochromatographic Test Strip with Fluorescent Detector for Quantification of Phosphorylated Acetycholinesterase: An Exposure Biomarker of Organophosphorous Agents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weiying; Ge, Xiaoxiao; Tang, Yong; Du, Dan; Liu, Deli; Lin, Yuehe

    2013-09-21

    A nanoparticle-based fluorescence immunochromatographic test strip (FITS) coupled with a hand-held detector for highly selective and sensitive detection of phosphorylated acetylcholinesterase (AChE), an exposure biomarker of organophosphate (OP) pesticides and nerve agents, is reported. In this approach, OP-AChE adducts were selectively captured by quantum dot-tagged anti-AChE antibodies (Qdot-anti-AChE) and zirconia nanoparticles (ZrO2 NPs). The sandwich-like immunoreactions were performed among the Qdot-anti-AChE, OP-AChE and ZrO2 NPs to form Qdot-anti-AChE/OP-AChE/ZrO2 complex, which was detected by recording the fluorescence intensity of Qdot captured on the test line. Paraoxon was used as the model OP pesticides. Under optimal conditions, this portable FITS immunosensor demonstrates a highly linear absorption response over the range of 0.01 nM to 10 nM OP-AChE, with a detection limit of 4 pM, coupled with a good reproducibility. Moreover, the FITS immunosensor has been validated with OP-AChE spiked human plasma samples. This is the first report on the development of ZrO2 NPs-based FITS for detection of OP-AChE adduct. The FITS immunosensor provides a sensitive and low-cost sensing platform for on-site screening/evaluating OP pesticides and nerve agents poisoning.

  19. Solar tests of aperture plate materials for solar thermal dish collectors

    Science.gov (United States)

    Jaffe, L. D.

    1984-11-01

    If a malfunction occurs in a solar thermal point-focus distributed receiver power plant while a concentrator is pointed at the sun, motion of the concentrator may stop. As the sun moves relative to the earth, the spot of concentrated sunlight then slowly walks off the receiver aperture, across the receiver face plate, and perhaps across adjacent portions of the concentrator. Intense local heating by the concentrated sunlight may damage or destroy these parts. The behavior of various materials under conditions simulating walk-off of a parabolic dish solar collector were evaluated. Each test consisted of exposure to concentrated sunlight at a peak flux density of about 7000 kW/square meter for 15 minutes. Types of materials tested included graphite, silicon carbide, silica, various silicates, alumina, zirconia, aluminum, copper, steel, and polytetrafluroethylene. The only material that neither cracked nor melted was grade G-90 graphite. Grade CS graphite, a lower cost commercial grade, cracked half-way across, but did not fail apart. Both of these grades are medium-grain extruded graphites. A graphite cloth (graphitized polyacrylonitrile) showed fair performance when tested as a single thin ply; it might be useful as a multi-ply assembly. High purity slipcast silica showed some promise also.

  20. Solar tests of aperture plate materials for solar thermal dish collectors

    Science.gov (United States)

    Jaffe, L. D.

    1984-01-01

    If a malfunction occurs in a solar thermal point-focus distributed receiver power plant while a concentrator is pointed at the sun, motion of the concentrator may stop. As the sun moves relative to the earth, the spot of concentrated sunlight then slowly walks off the receiver aperture, across the receiver face plate, and perhaps across adjacent portions of the concentrator. Intense local heating by the concentrated sunlight may damage or destroy these parts. The behavior of various materials under conditions simulating walk-off of a parabolic dish solar collector were evaluated. Each test consisted of exposure to concentrated sunlight at a peak flux density of about 7000 kW/square meter for 15 minutes. Types of materials tested included graphite, silicon carbide, silica, various silicates, alumina, zirconia, aluminum, copper, steel, and polytetrafluroethylene. The only material that neither cracked nor melted was grade G-90 graphite. Grade CS graphite, a lower cost commercial grade, cracked half-way across, but did not fail apart. Both of these grades are medium-grain extruded graphites. A graphite cloth (graphitized polyacrylonitrile) showed fair performance when tested as a single thin ply; it might be useful as a multi-ply assembly. High purity slipcast silica showed some promise also.

  1. Effect of sunlight on the survival of pathogenic E. coli in freshwater and sea water

    DEFF Research Database (Denmark)

    Surendraraj, Alagarsamy; Farvin, Sabeena; Thampuran, N.

    2011-01-01

    An enteropathogenic group of E. coli are the emerging category of pathogen of public health significance. Several recent pathogenic E. coli outbreaks are associated with drinking water. Aquaculture, the fast emerging food production sector also poses a pathogenic EHEC outbreak risk, as it regularly...... uses cow dung, a reservoir of this organism. Hence, a experiment was set up to study the duration of survival of pathogenic E. coli under sunlight and darkness. Eight pathogenic E. coli isolates from clinical (EPEC, ETEC, EHEC, EAEC), veterinary (CTE3, CTE4) and environmental sources (ASHE3, Rao II......) were studied for their survival under sunlight and darkness in fresh water and seawater. Effect of direct sunlight on the viable but nonculturable (VBNC) state of cultures was also studied. The results of the study indicated a distinct pattern between freshwater system and seawater system. Pathogenic E...

  2. Optical modeling of sunlight by using partially coherent sources in organic solar cells.

    Science.gov (United States)

    Alaibakhsh, Hamzeh; Darvish, Ghafar

    2016-03-01

    We investigate the effects of coherent and partially coherent sources in optical modeling of organic solar cells. Two different organic solar cells are investigated: one without substrate and the other with a millimeter-sized glass substrate. The coherent light absorption is calculated with rigorous coupled-wave analysis. The result of this method is convolved with a distribution function to calculate the partially coherent light absorption. We propose a new formulation to accurately model sunlight as a set of partially coherent sources. In the structure with glass substrate, the accurate sunlight modeling results in the elimination of coherent effects in the thick substrate, but the coherency in other layers is not affected. Using partially coherent sources instead of coherent sources for simulations with sunlight results in a smoother absorption spectrum, but the change in the absorption efficiency is negligible.

  3. De Novo Assembly and Comparative Transcriptome Analyses of Red and Green Morphs of Sweet Basil Grown in Full Sunlight

    National Research Council Canada - National Science Library

    Torre, Sara; Tattini, Massimiliano; Brunetti, Cecilia; Guidi, Lucia; Gori, Antonella; Marzano, Cristina; Landi, Marco; Sebastiani, Federico

    2016-01-01

    .... The development of a reference transcriptome for sweet basil, and the analysis of differentially expressed genes in acyanic and cyanic cultivars exposed to natural sunlight irradiance, has interest...

  4. Effect of long-term exposure of 2.4 GHz radiofrequency radiation emitted from Wi-Fi equipment on testes functions.

    Science.gov (United States)

    Dasdag, Suleyman; Taş, Muzaffer; Akdag, Mehmet Zulkuf; Yegin, Korkut

    2015-03-01

    The aim of this study was to investigate long-term effects of radiofrequency radiation (RFR) emitted from a Wireless Fidelity (Wi-Fi) system on testes. The study was carried out on 16 Wistar Albino adult male rats by dividing them into two groups such as sham (n: 8) and exposure (n: 8). Rats in the exposure group were exposed to 2.4 GHz RFR radiation for 24 h/d during 12 months (1 year). The same procedure was applied to the rats in the sham control group except the Wi-Fi system was turned off. Immediately after the last exposure, rats were sacrificed and reproductive organs were removed. Motility (%), concentration (×10(6)/mL), tail defects (%), head defects (%) and total morphologic defects (%) of sperms and weight of testes (g), left epididymis (g), prostate (g), seminal vesicles (g) were determined. Seminiferous tubules diameter (μm) and tunica albuginea thickness (μm) were also measured. However, the results were evaluated by using Johnsen's score. Head defects increased in the exposure group (p  0.05). In conclusion, we observed that long-term exposure of 2.4 GHz RF emitted from Wi-Fi (2420 μW/kg, 1 g average) affects some of the reproductive parameters of male rats. We suggest Wi-Fi users to avoid long-term exposure of RF emissions from Wi-Fi equipment.

  5. Sunlight, vitamin D and malignant melanoma: an update.

    Science.gov (United States)

    Reichrath, Jörg; Reichrath, Sandra

    2014-01-01

    Solar radiation represents an essential requirement for life, not only by spending the thermal energy for photosynthesis in plants, which provides our atmosphere with oxygen, but also by facilitating the cutaneous synthesis of vitamin D in vertebrates and many other organisms. It is well known that humans and most vertebrates have to obtain an adequate source of vitamin D, in order to develop and maintain a healthy mineralized skeleton and in order to be protected against cancer and a broad variety of other diseases. On the other hand, solar UV radiation can be assumed to be the most relevant environmental carcinogen causing melanoma and nonmelanoma skin cancer with increasing incidences. During the last decades, epidemiological studies and experimental animal models, including genetically engineered mice, the Xiphophorus hybrid fish, the south american oppossum and human skin xenografts, have further elucidated the multi-step process of UV-induced melanomagenesis. It has to be emphasized that, in contrast to intermittent, short-term high-dose solar UV-exposure, more chronic less intense exposure (which is recommended by many experts in the field to obtain a sufficient vitamin D status) has not been found to be a risk factor for the development of melanoma and in fact has been found in several studies to be protective. Interestingly, several independent lines of investigation have demonstrated convincing evidence that vitamin D and/or analogs may be effective in the prevention and treatment of melanoma. This essay summarizes our present understanding about the pathogenic role of UV radiation and of vitamin D for malignant melanoma.

  6. Using metal nanostructures to form hydrocarbons from carbon dioxide, water and sunlight

    Science.gov (United States)

    Wang, Cong; Shen, Mengyan; Huo, Haibin; Ren, Haizhou; Johnson, Michael

    2011-12-01

    Based on experimental results, we propose a mechanism that allows the use of metal nanostructures to synthesize hydrocarbons and carbohydrates from carbon dioxide, water and sunlight. When sunlight impinges on cobalt nanostructures in a glass chamber, its intensity is greatly enhanced around the tips of the nanostructures through surface plasmon excitations focusing effect, and it then photodissociates the water and carbon dioxide molecules through enhanced photon absorptions of ions around the tips of the nanostructures. The photodissociated molecules in excited states remain on the cobalt nanostructure surfaces and various hydrocarbons and carbohydrates then will be formed around the surfaces at temperatures much lower than 100 oC.

  7. The Seasonality of Tuberculosis, Sunlight, Vitamin D, and Household Crowding

    OpenAIRE

    2014-01-01

    Background.  Unlike other respiratory infections, tuberculosis diagnoses increase in summer. We performed an ecological analysis of this paradoxical seasonality in a Peruvian shantytown over 4 years. Methods.  Tuberculosis symptom-onset and diagnosis dates were recorded for 852 patients. Their tuberculosis-exposed cohabitants were tested for tuberculosis infection with the tuberculin skin test (n = 1389) and QuantiFERON assay (n = 576) and vitamin D concentrations (n = 195) quantified from ra...

  8. Chronic toxicity of hydrogen peroxide to Daphnia magna in a continuous exposure, flow-through test system

    Science.gov (United States)

    Meinertz, J.R.; Greseth, Shari L.; Gaikowski, M.P.; Schmidt, L.J.

    2008-01-01

    A flow-through, continuous exposure test system was developed to expose Daphnia magna to an unstable compound. 35% Perox-Aid?? is a specially formulated hydrogen peroxide (a highly oxidative chemical) product approved for use in U.S. aquaculture and therefore has the potential to be released from aquaculture facilities and pose a risk to aquatic invertebrates. The study objective was to assess the effects of 35% Perox-Aid?? on an aquatic invertebrate by evaluating the survival, growth, production, and gender ratio of progeny from a representative aquatic invertebrate continuously exposed to 35% Perox-Aid??. The study design consisted of 6 treatment groups (10 test chambers each) with target hydrogen peroxide concentrations of 0.0, 0.32, 0.63, 1.25, 2.5, and 5.0??mg L- 1. The study was initiated with peroxide for 21??days. Hydrogen peroxide concentrations ??? 1.25??mg L- 1 had no significant effect on Daphnia time to death compared to controls and no significant effect on the time to first brood production and the number of broods produced. Concentrations ??? 0.63??mg L- 1 had no significant effect on the total number of young produced. Concentrations ??? 0.32??mg L- 1 had a negative effect on Daphnia growth. Hydrogen peroxide had no significant effect on the gender ratio of young produced. All second generation Daphnia were female. A continuous discharge of hydrogen peroxide into aquatic ecosystems is not likely to affect cladocerans if the concentration is maintained at ??? 0.63??mg L- 1 for less than 21??days.

  9. Testing of a cumulative and aggregate exposure model using biomonitoring studies and dietary records for Italian vineyard spray operators.

    NARCIS (Netherlands)

    Kennedy, M.C.; Glass, C.R.; Fustinoni, S.; Moretto, A.; Mandic-Rajcevic, S.; Riso, P.; Turrini, A.; Voet, van der H.; Hetmanski, M.T.; Fussel, R.J.; Klaveren, van J.D.

    2015-01-01

    The need for improved tools to estimate the cumulative and aggregate exposure to compounds such as plant protection products (PPPs) is recognised in the EU Regulation 1107/2009. A new model has been developed to estimate the exposure within a population to single compounds or compounds within a Cumu

  10. A practical demonstration of water disinfection using TiO2 films and sunlight.

    Science.gov (United States)

    Gelover, Silvia; Gómez, Luis A; Reyes, Karina; Teresa Leal, Ma

    2006-10-01

    The scope of this study is the assessment of the efficiency of solar disinfection by heterogeneous photocatalysis with sol-gel immobilized (titanium dioxide) TiO2 films over glass cylinders. The solar disinfection process known as SODIS was considered as a reference. Spring water naturally polluted with coliform bacteria was exposed to sunlight in plastic bottles with and without TiO2 over simple solar collectors and the disinfection effectiveness was measured. Total and fecal coliforms quantification was performed by means of the chromogenic substrate method in order to obtain the efficiency of each disinfection treatment. The disinfection with TiO2 was more efficient than the SODIS process, inactivating total coliforms as well as fecal coliforms. On a sunny day (more than 1000 W m(-2) irradiance), it took the disinfection with immobilized TiO2 15 min of irradiation to inactivate the fecal coliforms to make them undetectable. For inactivation of total coliforms, 30 min was required, so that in less than half the time it takes SODIS, the treated water complies with the microbial standards for drinking water in Mexico. Another important part of this study has been to determine the bacterial regrowth in water after the disinfection processes were tested. After SODIS, bacterial regrowth of coliforms was observed. In contrast, when using the TiO2 catalyst, coliforms regrowth was not detected, neither for total nor for fecal coliforms. The disinfection process using TiO2 kept treated water free of coliforms at least for seven days after sun irradiation. This demonstration opens the possibility of application of this simple method in rural areas of developing countries.

  11. Antiradical capacity and polyphenol composition of asparagus spears varieties cultivated under diff erent sunlight conditions

    Directory of Open Access Journals (Sweden)

    Bartosz Kulczyński

    2016-09-01

    Full Text Available Background. Asparagus offi cinalis has a high nutritional value. Asparagus is rich in a number of bioactive compounds, mainly fl avonoids (quercetin, glutathione, vitamin C, vitamin E, fructans (inulin and fructooligosaccharides and phytosterols (b-sitosterol. These compounds may play an important role in human health. The purpose of this study was to examine the antioxidant potential and polyphenol composition of white, pale-colored and green asparagus spears of diff erent cultivars. Material and methods. Investigations were conducted on diff erent asparagus spear extracts. The study included three colors of asparagus (white, pale-colored and green from fi ve diff erent cultivars subjected to the ethanol extraction procedure. Total phenolic content was also determined by the Folin-Ciocalteu method. Polyphenol (phenolic acids and fl avonols composition was estimated using the HPLC method. The antioxidant properties of extracts were examined using DPPH, ABTS and metal ion chelating assays. Results. The highest contents of phenolic and fl avonoids were observed in green asparagus from Grolim and the lowest in pale-colored asparagus from Gyjmlin. It was found that both the color of asparagus and the cultivar had a signifi cant eff ect on the composition of phenolic acid and fl avonols. Radical scavenging activity toward DPPH• and ABTS was highest for green asparagus cv. Grolim and Eposs. The greatest number of Fe ions was chelated by samples of green asparagus cv. Grolim and Huchel’s Alpha and pale-colored asparagus cv. Huchel’s Alpha. Conclusion. It was shown that the antioxidant activity of asparagus spears measured by antiradical and chelating activity test depends on variety and color. The highest activity was found in green asparagus and the lowest was identifi ed in white asparagus extracts. It has also been clarifi ed that changes in fl avonol and phenolic acid composition and increases in their diversity depends on growing with

  12. Passive dosing of triclosan in multi-generation tests with copepods - Stable exposure concentrations and effects at the low µg l-1 range

    DEFF Research Database (Denmark)

    Ribbenstedt, Anton; Mustajärvi, Lukas; Breitholtz, Magnus

    2017-01-01

    to test the applicability of passive dosing to maintain stable concentrations of the organochlorine bacteriocide triclosan in the water phase during a 6-week multi-generation population development test with the harpacticoid copepod Nitocra spinipes. Triclosan was loaded into silicone (1000 mg), which...... was used as passive dosing phase in the exposure vials. The distribution ratio for triclosan between silicone and water (Dsilicone-water ) was 10466 ± 1927. A population development test was conducted at three concentration levels of triclosan that were measured to be 3-5 µg L(-1) , 7-11 µg L(-1) and 16...... exerted on juvenile development. Progressively lower development index values in the populations exposed to increasing triclosan concentrations suggest developmental retardation. Our results further stress the need for chronic exposure during ecotoxicity testing in chemical risk assessment as even...

  13. Passive dosing of triclosan in multi-generation tests with copepods - Stable exposure concentrations and effects at the low µg l-1 range

    DEFF Research Database (Denmark)

    Ribbenstedt, Anton; Mustajärvi, Lukas; Breitholtz, Magnus;

    2016-01-01

    to test the applicability of passive dosing to maintain stable concentrations of the organochlorine bacteriocide triclosan in the water phase during a 6-week multi-generation population development test with the harpacticoid copepod Nitocra spinipes. Triclosan was loaded into silicone (1000 mg), which...... was used as passive dosing phase in the exposure vials. The distribution ratio for triclosan between silicone and water (Dsilicone-water ) was 10466 ± 1927. A population development test was conducted at three concentration levels of triclosan that were measured to be 3-5 µg L(-1) , 7-11 µg L(-1) and 16...... exerted on juvenile development. Progressively lower development index values in the populations exposed to increasing triclosan concentrations suggest developmental retardation. Our results further stress the need for chronic exposure during ecotoxicity testing in chemical risk assessment as even...

  14. Passive dosing of triclosan in multi-generation tests with copepods - Stable exposure concentrations and effects at the low µg l-1 range

    DEFF Research Database (Denmark)

    Ribbenstedt, Anton; Mustajärvi, Lukas; Breitholtz, Magnus

    2016-01-01

    Ecotoxicity testing is a crucial component of chemical risk assessment. Still, due to methodological difficulties related to controlling exposure concentrations over time, data on long-term effects of organic chemicals at low concentrations are limited. The aim of the present study was therefore...... to test the applicability of passive dosing to maintain stable concentrations of the organochlorine bacteriocide triclosan in the water phase during a 6-week multi-generation population development test with the harpacticoid copepod Nitocra spinipes. Triclosan was loaded into silicone (1000 mg), which...... was used as passive dosing phase in the exposure vials. The distribution ratio for triclosan between silicone and water (Dsilicone-water ) was 10466 ± 1927. A population development test was conducted at three concentration levels of triclosan that were measured to be 3-5 µg L(-1) , 7-11 µg L(-1) and 16...

  15. Tanpopo: Astrobiology Exposure and Micrometeoroid Capture, a Sample Return Experiment to Test Quasi-Panspermia Hypothesis Onboard the ISS-Kibo Exposed Facility

    Science.gov (United States)

    Yano, H.; Yamagishi, A.; Hashimoto, H.; Yokobori, S.; Kobayashi, K.; Yabuta, H.; Mita, H.; Tabata, M.; Kawai, H.; Higashide, M.; Okudaira, K.; Sasaki, S.; Imai, E.; Kawaguchi, Y.; Uchibori, Y.; Kodaira, S.; Tanpopo Project Team

    2013-11-01

    As the first Japanese astrobiology experiment in space, the Tanpopo will test key concepts of the quasi-panspermia hypothesis by sample returns of microbe and bio-orgaincs exposure and micrometeoroid capture onboard ISS-Kibo Exposed Facility ExHAM.

  16. Reversible degradation in ITO-containing organic photovoltaics under concentrated sunlight

    NARCIS (Netherlands)

    Galagan, Y.O.; Mescheloff, A.; Veenstra, S.C.; Andriessen, H.A.J.M.; Katz, E.A.

    2015-01-01

    Stabilities of ITO-containing and ITO-free organic solar cells were investigated under simulated AM 1.5G illumination and under concentrated natural sunlight. In both cases ITO-free devices exhibit high stability, while devices containing ITO show degradation of their photovoltaic performance. The a

  17. Hybrid sunlight/LED illumination and renewable solar energy saving concepts for indoor lighting.

    Science.gov (United States)

    Tsuei, Chih-Hsuan; Sun, Wen-Shing; Kuo, Chien-Cheng

    2010-11-08

    A hybrid method for using sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting is simulated and presented in this study. We can illuminate an indoor space and collect the solar energy using an optical switching system. When the system is turned off, the full spectrum of the sunlight is concentrated by a concentrator, to be absorbed by solar photovoltaic devices that provide the electricity to power the LEDs. When the system is turned on, the sunlight collected by the concentrator is split into visible and non-visible rays by a beam splitter. The visible rays pass through the light guide into a light box where it is mixed with LED light to ultimately provide uniform illumination by a diffuser. The non-visible rays are absorbed by the solar photovoltaic devices to provide electrical power for the LEDs. Simulation results show that the efficiency of the hybrid sunlight/LED illumination with the renewable solar energy saving design is better than that of LED and traditional lighting systems.

  18. Greenhouse Effect: Temperature of a Metal Sphere Surrounded by a Glass Shell and Heated by Sunlight

    Science.gov (United States)

    Nguyen, Phuc H.; Matzner, Richard A.

    2012-01-01

    We study the greenhouse effect on a model satellite consisting of a tungsten sphere surrounded by a thin spherical, concentric glass shell, with a small gap between the sphere and the shell. The system sits in vacuum and is heated by sunlight incident along the "z"-axis. This development is a generalization of the simple treatment of the…

  19. Degradation of benzotriazole and benzothiazole in treatment wetlands and by artificial sunlight.

    Science.gov (United States)

    Felis, Ewa; Sochacki, Adam; Magiera, Sylwia

    2016-11-01

    Laboratory-scale experiments were performed using unsaturated subsurface-flow treatment wetlands and artificial sunlight (with and without TiO2) to study the efficiency of benzotriazole and benzothiazole removal and possible integration of these treatment methods. Transformation products in the effluent from the treatment wetlands and the artificial sunlight reactor were identified by high performance liquid chromatography coupled with tandem mass spectrometry. The removal of benzothiazole in the vegetated treatment wetlands was 99.7%, whereas the removal of benzotriazole was 82.8%. The vegetation positively affected only the removal of benzothiazole. The major transformation products in the effluents from the treatment wetlands were methylated and hydroxylated derivatives of benzotriazole, and hydroxylated derivatives of benzothiazole. Hydroxylation was found to be the main process governing the transformation pathway for both compounds in the artificial sunlight experiment (with and without TiO2). Benzotriazole was not found to be susceptible to photodegradation in the absence of TiO2. The integration of the sunlight-induced processes (with TiO2) with subsurface-flow treatment wetlands caused further elimination of the compounds (42% for benzotriazole and 58% for benzothiazole). This was especially significant for the elimination of benzotriazole, because the removal of this compound was 96% in the coupled processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Contamination-Focused Exposure as a Treatment for Disgust-Based Fears: A Preliminary Test in Spider-Fearful Women.

    Science.gov (United States)

    Cougle, Jesse R; Summers, Berta J; Harvey, Ashleigh M; Dillon, Kirsten H; Allan, Nicholas P

    2016-11-01

    Disgust is thought to play a prominent role in multiple anxiety disorders and fears, including spider phobia, though little attention has been given to specific treatment strategies that may be effective for multiple disgust-based fears. In the present study, we evaluated contamination-focused exposure as a potential transdiagnostic treatment strategy for disgust-based fears in a spider fearful sample. Women with significant spider fear were randomized to three 30-minute sessions of exposure therapy involving repeated contact with a dirt mixture (n=17) or a waitlist control condition (n=17). Assessments of spider fear and disgust were administered at baseline and at one-week posttreatment. At high (but not low) levels of pretreatment disgust propensity, exposure led to lower in vivo spider fear and perceived danger than waitlist, though exposure had no effects on spider-related disgust. Similar effects of exposure on spider fear were found at high levels of pretreatment spider-related disgust. Exposure also reduced fear and danger perceptions, but not disgust, related to a separate contamination assessment (touching a toilet). No effects of treatment were found on self-report measures of spider fear or disgust propensity. These findings suggest contamination-focused exposure therapy may be an effective transdiagnostic treatment strategy for individuals with elevated disgust propensity. Limitations and directions for future research are discussed.

  1. Utilization of the National Health and Nutrition Examination (NHANES) Survey for Symptoms, Tests, and Diagnosis of Chronic Respiratory Diseases and Assessment of Second hand Smoke Exposure.

    Science.gov (United States)

    Koru-Sengul, Tulay; Clark, John D; Ocasio, Manuel A; Wanner, Adam; Fleming, Lora E; Lee, David J

    2011-10-01

    Respiratory diseases encompass a number of complex disorders that constitute a major cause of both morbidity and mortality worldwide with a major burden to the afflicted as well as the health care systems that care for them. Although the prevalence of chronic respiratory diseases (CRDs) has been decreasing in industrialized countries due to a decreasing number of smokers and stricter laws aimed at reducing exposure to secondhand smoke (SHS), the burden of CRDs in developing world populations is expected to worsen due to communicable disease prevention programs, aging populations, environmental air pollution, and continued tobacco smoke exposure. Although tobacco smoking has been shown to be significantly associated with many CRDs, evidence linking SHS exposure to different CRDs is mixed, especially with low levels of SHS exposure. The National Health and Nutrition Examination Survey (NHANES) is a series of studies designed to assess the health and nutritional status of non-institutionalized adults and children in the United States (U.S.). In addition to being used to monitor the health of the U.S. population, NHANES data allow for research into prevalent health problems and their risk factors in the population, such with CRDs and SHS exposure. NHANES data can be utilized to explore a variety of issues related to the assessment of SHS exposure and its association to respiratory symptoms and illnesses. First, we provide a brief review of NHANES including its strengths and limitations. We then provide a summary of the variables and publically available population based data that can be used to study associations between SHS exposure and CRD symptoms, testing and diagnoses. Rich and cost effective, NHANES data provide a unique opportunity for research into the risk factors for CRDs in the U.S. population, particularly into the possible health effects of low levels of SHS exposure.

  2. [Alveolar macrophages and mononuclear cells of the peripheral blood in sulfur dioxide and chrysotile B exposure: a realistic in vitro test of oxygen free radical liberation].

    Science.gov (United States)

    Knorst, M M; Kienast, K; Müller-Quernheim, J; Ferlinz, R

    1993-05-01

    Sulfur dioxide (SO2) and Asbest are frequently found at workplaces. They can induce airway and lung parenchymal injury. Alveolar macrophages (AM) play an important and decisive role in the damage of respiratory tissue. We evaluated the reactive oxygen intermediates (ROI) production of AM and peripheral blood mononuclear cells after exposure with SO2 and Chrysotile B. The cells were exposed in a special gas exposure chamber at 37 degrees C and 100% air humidity for 30 minutes to 1.5 or 2.5 ppm SO2. Afterwards they were incubated for one hour with 100 micrograms or 200 micrograms Chrysotile B. Control experiments were performed with cell exposure to synthetic air without SO2 and Chrysotile B. Spontaneous and phorbol myristate acetate (PMA) stimulated ROI-release were measured by chemiluminescence and the cell toxicity was evaluated with the trypan blue exclusion test. Our results show a dose-dependent increase of the spontaneous ROI-production of AM after SO2 and Chrysotile B exposure. Exposure to 100 micrograms Chrysotile B caused an 1.5 fold, exposure to 1.5 or 2.5 ppm SO2 plus 100 micrograms Chrysotile B resulted in an 2.4 respectively 3.3 fold increase in ROI-release compared to control experiments. Exposure of AM to 200 micrograms Chrysotile B yielded an 1.9 fold, exposure to 2.5 ppm SO2 plus 200 micrograms Chrysotile B a 3.9 fold elevation in the spontaneous ROI-production compared to control experiment with standard air. A similar reaction pattern was observed in PMA-stimulated AM and in peripheral blood mononuclear cells.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Aconitine Challenge Test Reveals a Single Exposure to Air Pollution Causes Increased Cardiac Arrhythmia Risk in Hypertensive Rats - Abstract

    Science.gov (United States)

    Epidemiological studies demonstrate a significant association between arrhythmias and air pollution exposure. Sensitivity to aconitine-induced arrhythmia has been used repeatedly to examine the factors that increase the risk of such cardiac electrical dysfunction. In this study, ...

  4. Specifying the interrelationship between exposure to violence and parental monitoring for younger versus older adolescents: a five year longitudinal test.

    Science.gov (United States)

    Spano, Richard; Rivera, Craig; Vazsonyi, Alexander T; Bolland, John M

    2012-03-01

    Five waves of longitudinal data collected from 349 African American youth living in extreme poverty were used to examine the interrelationship between exposure to violence and parenting during adolescence. Semi-parametric group based modeling was used to identify trajectories of parental monitoring and exposure to violence from T1 to T5. Results from these analyses revealed: (1) a trajectory of declining parental monitoring for 48% of youth; and (2) four distinct trajectories of exposure to violence. Multivariate findings were largely consistent with the ecological-transactional model of community violence. Youth with stable and/or increasing trajectories of exposure to violence were more likely than youth with stable-low exposure to violence to have declining parental monitoring, but additional analyses revealed a similar pattern of findings for younger adolescents (age 9-11 T1), but no evidence of linkages between trajectories of exposure to violence and parental monitoring for older adolescents (age 12-16 T1). The theoretical and policy implications of these findings as well as areas for future research are also discussed.

  5. Local Adaptation of Sun-Exposure-Dependent Gene Expression Regulation in Human Skin

    Science.gov (United States)

    Kita, Ryosuke; Fraser, Hunter B.

    2016-01-01

    Sun-exposure is a key environmental variable in the study of human evolution. Several skin-pigmentation genes serve as classical examples of positive selection, suggesting that sun-exposure has significantly shaped worldwide genomic variation. Here we investigate the interaction between genetic variation and sun-exposure, and how this impacts gene expression regulation. Using RNA-Seq data from 607 human skin samples, we identified thousands of transcripts that are differentially expressed between sun-exposed skin and non-sun-exposed skin. We then tested whether genetic variants may influence each individual’s gene expression response to sun-exposure. Our analysis revealed 10 sun-exposure-dependent gene expression quantitative trait loci (se-eQTLs), including genes involved in skin pigmentation (SLC45A2) and epidermal differentiation (RASSF9). The allele frequencies of the RASSF9 se-eQTL across diverse populations correlate with the magnitude of solar radiation experienced by these populations, suggesting local adaptation to varying levels of sunlight. These results provide the first examples of sun-exposure-dependent regulatory variation and suggest that this variation has contributed to recent human adaptation. PMID:27760139

  6. Cigarette smoke induced genotoxicity and respiratory tract pathology: evidence to support reduced exposure time and animal numbers in tobacco product testing.

    Science.gov (United States)

    Dalrymple, Annette; Ordoñez, Patricia; Thorne, David; Walker, David; Camacho, Oscar M; Büttner, Ansgar; Dillon, Debbie; Meredith, Clive

    2016-06-01

    Many laboratories are working to develop in vitro models that will replace in vivo tests, but occasionally there remains a regulatory expectation of some in vivo testing. Historically, cigarettes have been tested in vivo for 90 days. Recently, methods to reduce and refine animal use have been explored. This study investigated the potential of reducing animal cigarette smoke (CS) exposure to 3 or 6 weeks, and the feasibility of separate lung lobes for histopathology or the Comet assay. Rats were exposed to sham air or CS (1 or 2 h) for 3 or 6 weeks. Respiratory tissues were processed for histopathological evaluation, and Alveolar type II cells (AEC II) isolated for the Comet assay. Blood was collected for Pig-a and micronucleus quantification. Histopathological analyses demonstrated exposure effects, which were generally dependent on CS dose (1 or 2 h, 5 days/week). Comet analysis identified that DNA damage increased in AEC II following 3 or 6 weeks CS exposure, and the level at 6 weeks was higher than 3 weeks. Pig-a mutation or micronucleus levels were not increased. In conclusion, this study showed that 3 weeks of CS exposure was sufficient to observe respiratory tract pathology and DNA damage in isolated AEC II. Differences between the 3 and 6 week data imply that DNA damage in the lung is cumulative. Reducing exposure time, plus analyzing separate lung lobes for DNA damage or histopathology, supports a strategy to reduce and refine animal use in tobacco product testing and is aligned to the 3Rs (replacement, reduction and refinement).

  7. Water splitting and electricity with semiconducting silicides in sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Demuth, Martin [Max-Planck-Institut fuer Bioanorganische Chemie, Muelheim an der Ruhr (Germany); H2 Solar GmbH, Loerrach (Germany); Kerpen, Klaus; Kuklya, Andriy; Wuestkamp, Marc-Andre [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany)

    2010-07-01

    Generation of hydrogen and oxygen from water is described using mainly the semiconductor titanium disilicide as catalyst and halogen light which closely mimics solar radiation. The reactions are carried out under non-aerobic conditions, i.e., under nitrogen. High efficiencies are reached at 1.1-1.2 bar pressure. In the first phase of these reactions the catalytically active centers are built up. During this phase of reaction the kinetics of the water splitting process is growing in and leads to a linear dependence in the further course of the reactions which consists of >96% water splitting to yield hydrogen and oxygen in a 2:1 ratio. Hydrogen is partially and reversibly stored physically, depending on temperature. Oxygen behaves differently since it is stored entirely under the applied reaction conditions (50-80 C and light) and can be liberated from storage upon heating the slurries in the dark. This allows convenient separation of hydrogen and oxygen. The stability of titanium disilicide has been positively tested over several months. This material is abundant and inexpensive besides that it absorbs most of the solar radiation. Further, XRD and XPS studies show that titanium disilicide is 80% crystalline and the oxide formation is limited to a few molecular layers in depth. By using labeled water it was shown that labeled dioxygen appears in the gas phase of such reactions, this showing definitively that hydrogen evolution occuring here stems from photochemical splitting of water. Further, water splitting is part of a project which involves photoelectrochemistry and in which the silicides are used as light-receiving electrode and transition metal-coated anodes serve to split water. (orig.)

  8. Community Violence Exposure and Callous-Unemotional Traits in Adolescents: Testing Parental Support as a Promotive Versus Protective Factor.

    Science.gov (United States)

    Davis, Tess; Ammons, Chrissy; Dahl, Alexandra; Kliewer, Wendy

    2015-04-01

    Although callous-unemotional (CU) traits are associated with maladjustment in youth, literature predicting CU using prospective designs is rare. In the present study we examine associations between exposure to community violence, supportive relationships with caregivers, and CU in a sample of 236 low-income youth (M age = 13.00 yrs, SD = 1.56 yrs; 43% male; 92% African American) participating in a 3-wave longitudinal study of violence exposure and adjustment. Both promotive and protective models of linkages between exposure to community violence, support, and CU were investigated. Given known sex differences in CU, sex was explored as a moderator. Regression analysis revealed that witnessing and hearing about community violence, aggregated over 2 waves, were positively associated with CU at the final study wave. Supportive relationships with caregivers, aggregated over 2 waves, were negatively associated with CU but did not interact with violence exposure, suggesting that supportive relationships with caregivers has a promotive but not a protective association with CU in the context of exposure to violence. The pattern of associations did not vary by sex. This study informs our understanding of factors that contribute to the development of CU.

  9. Reducing employee exposure potential using the ANSI/ASHRAE 110 Method of Testing Performance of Laboratory Fume Hoods as a diagnostic tool.

    Science.gov (United States)

    Maupins, K; Hitchings, D T

    1998-02-01

    The primary goal of a laboratory ventilation system is to assure that employee exposure to hazardous chemicals does not exceed acceptable levels. Industrial hygienists at Eli Lilly & Co. were concerned about the adequacy of fume hoods to protect workers in an aging laboratory facility. Wanting to conduct a comprehensive series of tests for a true reading on the containment effectiveness of these hoods, the industrial hygienists went beyond the traditional face velocity tests. Tests prescribed in the ANSI/ASHRAE 110 Method of Testing Performance of Laboratory Fume Hoods (ASHRAE 110) standard including low- and high-volume smoke tests, face velocity tests, and tracer gas containment tests indicated that many of the hoods did not meet industry consensus standards for containment (0.1 ppm), yet met industry recommended face velocity specifications (80-120 ft/min). Based on the results of performance tests and engineering observations of the facility, apparent causes of poor performance were identified, and a mitigation plan was implemented to bring the hoods to the desired containment standards. After completion of the improvements, retesting was conducted to confirm achievement of these standards. Pre- and postmitigation test results, indicating a 99.5% reduction in tracer gas leakage or potential employee exposures, build a strong case for a more complete testing protocol as specified by the ASHRAE 110 test method. The authors recommend that traditional face velocity testing alone be discontinued in favor of the ASHRAE 110 method as a quantitative measure of fume hood performance coupled with the traditional face velocity measurement at periodic intervals to assure continued performance.

  10. Identification of Nitration Products during Heterogeneous Reaction of NO2 on Soot in the Dark and under Simulated Sunlight.

    Science.gov (United States)

    Guan, Chun; Li, Xinling; Zhang, Wugao; Huang, Zhen

    2017-01-19

    Author: The present work, involving the formation of NO and nitrous acid (HONO) and the nitration of polycyclic aromatic hydrocarbon (PAHs) to nitro-PAHs as well as the uptake coefficients of NO2, has been performed on a normal-pressure flow reactor to identify the nitration products during the heterogeneous reaction of soot toward NO2 in the dark and under simulated sunlight. Two types of soot particles, namely the commercial black carbon (BC) and the diesel engine soot (ES), were selected as the studied soot to compare the impacts of soot properties on heterogeneous nitration. During the whole reaction on either of the two studied soots in the dark, a fast reversible physical adsorption is observed at the very beginning, followed by a slow irreversible chemical conversion from NO2 to HONO and NO, in good agreement with the "reduction-oxidation" mechanism. HONO is the most abundant product during the nitration reaction on the two studied soots, contributing to 70-90% of consumed NO2 after 50 min exposure. Reaction orders of NO2 for HONO are determined as 1.20 ± 0.07 and 1.31 ± 0.04 for BC and ES, respectively, which are both close to first-order. Moreover, four sorts of PAHs compounds and their five nitro-derivatives have been identified and quantified during the reaction. About 40% and 20% of the total four measured PAHs are consumed on BC and ES, respectively, resulting in an increase in the total five measured nitro-PAHs by 21-fold on BC and 2.8-fold on ES. Finally, the impacts of light on gaseous and organics products have been investigated and the results confirm that simulated sunlight can enhance the reactivity of PAHs toward NO2 and cause the photolysis of newly formed nitro-compounds with more HONO formation, strongly suggesting that photochemistry of soot in the presence of NO2 is of great importance to be a photochemical source of HONO and would also influence the fates of PAHs and nitro-PAHs on soot.

  11. Free radicals induced by sunlight in different spectral regions - in vivo versus ex vivo study.

    Science.gov (United States)

    Lohan, Silke B; Müller, Robert; Albrecht, Stephanie; Mink, Kathrin; Tscherch, Kathrin; Ismaeel, Fakher; Lademann, Jürgen; Rohn, Sascha; Meinke, Martina C

    2016-05-01

    Sunlight represents an exogenous factor stimulating formation of free radicals which can induce cell damage. To assess the effect of the different spectral solar regions on the development of free radicals in skin, in vivo electron paramagnetic resonance (EPR) investigations with human volunteers and ex vivo studies on excised human and porcine skin were carried out. For all skin probes, the ultraviolet (UV) spectral region stimulates the most intensive radical formation, followed by the visible (VIS) and the near infrared (NIR) regions. A comparison between the different skin models shows that for UV light, the fastest and highest production of free radicals could be detected in vivo, followed by excised porcine and human skin. The same distribution pattern was found for the VIS/NIR spectral regions, whereby the differences in radical formation between in vivo and ex vivo were less pronounced. An analysis of lipid composition in vivo before and after exposure to UV light clearly showed modifications in several skin lipid components; a decrease of ceramide subclass [AP2] and an increase of ceramide subclass [NP2], sodium cholesterol sulphate and squalene (SQ) were detectable. In contrast, VIS/NIR irradiation led to an increase of ceramides [AP2] and SCS, and a decrease of SQ. These results, which are largely comparable for the different skin models investigated in vivo and ex vivo, indicate that radiation exposure in different spectral regions strongly influences radical production in skin and also results in changes in skin lipid composition, which is essential for barrier function.

  12. Photodegradation of 2,4-Dichlorophenol in Aqueous Systems under Simulated and Natural Sunlight

    Directory of Open Access Journals (Sweden)

    Dorota Gryglik

    2016-01-01

    Full Text Available The work presents results of studies on 2,4-dichlorophenol (2,4-DCP degradation in aqueous solutions using photochemically initiated processes by simulated and natural sunlight. A number of possible substrate photodegradation routes were investigated, by both direct photolysis and photosensitized oxidation process. The major role of singlet oxygen in 2,4-DCP photodegradation was proved. Rose Bengal and derivatives of porphine and phthalocyanine were used as sensitizers. The influences of various process parameters on the reaction rate were investigated. On the basis of experimental data reaction rate constants of 2,4-DCP photosensitized oxidation were determined. The possibility of using natural sunlight to degrade 2,4-DCP in water in the middle latitudes was stated. The acute toxicity bioassay was conducted with the marine bacterium Vibrio fischeri as a bioluminescent indicator. The obtained results encourage further research on this process.

  13. Formation of Silicon Carbide Using Volcanic Ash as Starting Material and Concentrated Sunlight as Energy Resource

    Directory of Open Access Journals (Sweden)

    Kensuke Nishioka

    2015-01-01

    Full Text Available SiC was formed using volcanic ash as starting material and concentrated sunlight as energy resource. The solar furnace was composed of two parts: Fresnel lens and reacting furnace. The reacting furnace was composed of a cylindrical vacuum chamber and quartz glass plate functioning to guide the concentrated sunlight into the furnace and was placed at the focal point of the Fresnel lens. The sample was made from the mixture of silica formed from volcanic ash and graphite and placed in the carbon crucible inside the reacting furnace. The temperature in the carbon crucible reached more than 1500°C. After the reaction using concentrated light, β-SiC was formed. The weight % of formed SiC was 90.5%.

  14. Sunlight-activated AlFeO3/TiO2 photocatalyst

    Institute of Scientific and Technical Information of China (English)

    YUAN; Zhihao; WANG; Yuhong; SUN; Yongchang; WANG; Jing; BIE; Lijian; DUAN; Yueqing

    2006-01-01

    A nanocomposite photocatalyst composed of AlFeO3 and TiO2 is prepared, and characterized through X-ray diffraction. Application of the nanocomposite for the photodegradations of eosin dye and methyl orange gives an improved photoactivity compared with TiO2-only nanomaterials. The optimal concentration of AlFeO3 in the composite is about 1.0 wt% under UV excitation, and 9.0 wt% under sunlight excitation for the improved photoactivity. Furthermore, this nanocomposite is more active for eosin photodegradation if natural sunlight rather than UV is used. This may be due to the reason that adding AlFeO3 nanoparticles into TiO2 matrix can promote the separation of photogenerated charge carriers, and extend the photoresponse of TiO2 toward visible region, which results in an increase in the solar energy utilization efficiency.

  15. Interlaboratory testing of 42-d Hyalella azteca survival, growth and reproduction method with sediment and water-only exposures

    Science.gov (United States)

    Over the past four years, USEPA-Duluth, USGS-Columbia, the Illinois Natural History Survey, and Environment Canada have conducted studies to refine the USEPA/ASTM International methods for conducting 10- to 42-d water or sediment toxicity exposures with Hyalella azteca. In advanc...

  16. Relapse of Extinguished Fear after Exposure to a Dangerous Context Is Mitigated by Testing in a Safe Context

    Science.gov (United States)

    Goode, Travis D.; Kim, Janice J.; Maren, Stephen

    2015-01-01

    Aversive events can trigger relapse of extinguished fear memories, presenting a major challenge to the long-term efficacy of therapeutic interventions. Here, we examined factors regulating the relapse of extinguished fear after exposure of rats to a dangerous context. Rats received unsignaled shock in a distinct context ("dangerous"…

  17. Interlaboratory testing of 42-d Hyalella azteca survival, growth and reproduction method with sediment and water-only exposures

    Science.gov (United States)

    Over the past four years, USEPA-Duluth, USGS-Columbia, the Illinois Natural History Survey, and Environment Canada have conducted studies to refine the USEPA/ASTM International methods for conducting 10- to 42-d water or sediment toxicity exposures with Hyalella azteca. In advanc...

  18. Gender differences in transcriptional signature of developing rat testes and ovaries following embryonic exposure to 2,3,7,8-TCDD.

    Directory of Open Access Journals (Sweden)

    Solange Magre

    Full Text Available Dioxins are persistent organic pollutants interfering with endocrine systems and causing reproductive and developmental disorders. The objective of our project was to determine the impact of an in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD on reproductive function of male and female offspring in the rat with a special emphasis on the immature period. We used a low dose of TCDD (unique exposure by oral gavage of 200 ng/kg at 15.5 days of gestation in order to mirror a response to an environmental dose of TCDD not altering fertility of the progeny. We choose a global gene expression approach using Affymetrix microarray analysis, and testes of 5 days and ovaries of 14 days of age. Less than 1% of the expressed genes in gonads were altered following embryonic TCDD exposure; specifically, 113 genes in ovaries and 56 in testes with 7 genes common to both sex gonads. It included the repressor of the aryl hydrocarbon receptor (Ahrr, the chemokines Ccl5 and Cxcl4 previously shown to be regulated by dioxin in testis, Pgds2/Hpgds and 3 others uncharacterized. To validate and extend the microarray data we realized real-time PCR on gonads at various developmental periods of interest (from 3 to 25 days for ovaries, from 5 to the adult age for testes. Overall, our results evidenced that both sex gonads responded differently to TCDD exposure. For example, we observed induction of the canonic battery of TCDD-induced genes coding enzymes of the detoxifying machinery in ovaries aged of 3-14 days of age (except Cyp1a1 induced at 3-10 days but not in testes of 5 days (except Ahrr. We also illustrated that inflammatory pathway is one pathway activated by TCDD in gonads. Finally, we identified several new genes targeted by TCDD including Fgf13 in testis and one gene, Ptgds2/Hpgds regulated in the two sex gonads.

  19. Effect of rapid HIV testing on HIV incidence and services in populations at high risk for HIV exposure: an equity-focused systematic review

    OpenAIRE

    Pottie, Kevin; Medu, Olanrewaju; Welch, Vivian; Dahal, Govinda P.; Tyndall, Mark; Rader, Tamara; Wells, George

    2014-01-01

    Objective To assess the effects of rapid voluntary counselling and testing (VCT) for HIV on HIV incidence and uptake of HIV/AIDS services in people at high risk for HIV exposure. Design Cochrane systematic review and meta-analysis. Data sources We searched PubMed, EMBASE, AIDSearch, LILACS, Global Health, Medline Africa, PsychInfo, CINAHL, Cochrane CENTRAL, Cochrane HIV/AIDS Group Specialized Register and grey literature from 1 January 2001 to 5 June 2014 without language restriction. Data se...

  20. Power Output Improvement of PV Module for Agricultural Use by Using Inexpensive Sunlight Concentrator

    Institute of Scientific and Technical Information of China (English)

    NISHIMURA Ryo

    2010-01-01

    PV modules are used as stand alone power sources for agricultural equipments such as lifting pumps in farms,where the power infrastructure is not yet improved.In order to expand the agricultural use of PV module,the cost of PV generation should be reduced.In this paper,the power output performance of a commercial PV module was improved by using a sunlight concentrator that could be assembled inexpensively and a simple sun-tracking method.

  1. Calculation of the optimum thickness of thermo-insulation for collectors of sunlight installations

    Directory of Open Access Journals (Sweden)

    Ermuratskii V.V.

    2005-12-01

    Full Text Available In the work the task of calculation of the optimum thickness of thermo-insulation for collectors of sunlight and accumulators of the heat is considered. The simplified model of calculation and the technique based on an estimation of efficiency of investment projects is offered. It is shown, that at calculation on the simplified model which are not taking into account financial streams, the overestimated values of thickness thermo-insulation turn out.

  2. Multiple scattering of polarized light in planetary atmospheres. II - Sunlight reflected by terrestrial water clouds.

    Science.gov (United States)

    Hansen, J. E.

    1971-01-01

    The intensity and polarization of sunlight reflected by terrestrial water clouds are computed with the doubling method. The calculations illustrate that this method can be effectively used in problems involving strongly anisotropic phase matrices. The method can, therefore, be used to derive information about planetary clouds, including those of the earth, from polarimetric observations. The results of the computations indicate that the polarization is more sensitive than the intensity to cloud microstructure, such as particle size and shape.

  3. Highly Branched Sn-Doped ZnO Nanostructures for Sunlight Driven Photocatalytic Reactions

    Directory of Open Access Journals (Sweden)

    Yangyang Liu

    2014-01-01

    Full Text Available Ultralong, highly branched Sn-doped zinc oxide (ZnO nanostructures were fabricated using a simple substrate-free chemical vapor deposition (CVD method. The nanostructures exhibited efficient photocatalytic activities in degradation of methylene blue (MB under natural sunlight. 100% of MB with the concentration of 10 mg/L could be completely removed within 36 minutes. Possible reasons for the enhanced photocatalytic effect were analyzed.

  4. Highly Branched Sn-Doped ZnO Nanostructures for Sunlight Driven Photocatalytic Reactions

    OpenAIRE

    2014-01-01

    Ultralong, highly branched Sn-doped zinc oxide (ZnO) nanostructures were fabricated using a simple substrate-free chemical vapor deposition (CVD) method. The nanostructures exhibited efficient photocatalytic activities in degradation of methylene blue (MB) under natural sunlight. 100% of MB with the concentration of 10 mg/L could be completely removed within 36 minutes. Possible reasons for the enhanced photocatalytic effect were analyzed.

  5. The Photocatalytic Activity of TiO2-Zeolite Composite for Degradation of Dye Using Synthetic UV and Jeddah Sunlight

    Directory of Open Access Journals (Sweden)

    Laila M. Al-Harbi

    2015-01-01

    Full Text Available In this research different composites of impregnated TiO2 with LTA or FAU zeolites were used as different weight% ratio for photodegradation of organic dye. Normal laboratory UV-lamps were used as a source of UV irradiation. In addition a setup of system of mirrors was used to collect real Jeddah sunlight. A comparison of UV and real sunlight photodegradation activity showed that the real sunlight enhances new centers of active sites exhibiting higher catalytic activity than that of UV irradiated samples.

  6. No effects of power line frequency extremely low frequency electromagnetic field exposure on selected neurobehavior tests of workers inspecting transformers and distribution line stations versus controls.

    Science.gov (United States)

    Li, Li; Xiong, De-fu; Liu, Jia-wen; Li, Zi-xin; Zeng, Guang-cheng; Li, Hua-liang

    2014-03-01

    We aimed to evaluate the interference of 50 Hz extremely low frequency electromagnetic field (ELF-EMF) occupational exposure on the neurobehavior tests of workers performing tour-inspection close to transformers and distribution power lines. Occupational short-term "spot" measurements were carried out. 310 inspection workers and 300 logistics staff were selected as exposure and control. The neurobehavior tests were performed through computer-based neurobehavior evaluation system, including mental arithmetic, curve coincide, simple visual reaction time, visual retention, auditory digit span and pursuit aiming. In 500 kV areas electric field intensity at 71.98% of total measured 590 spots were above 5 kV/m (national occupational standard), while in 220 kV areas electric field intensity at 15.69% of total 701 spots were above 5 kV/m. Magnetic field flux density at all the spots was below 1,000 μT (ICNIRP occupational standard). The neurobehavior score changes showed no statistical significance. Results of neurobehavior tests among different age, seniority groups showed no significant changes. Neurobehavior changes caused by daily repeated ELF-EMF exposure were not observed in the current study.

  7. Spore sensitivity to sunlight and freezing can restrict dispersal in wood-decay fungi.

    Science.gov (United States)

    Norros, Veera; Karhu, Elina; Nordén, Jenni; Vähätalo, Anssi V; Ovaskainen, Otso

    2015-08-01

    Assessment of the costs and benefits of dispersal is central to understanding species' life-history strategies as well as explaining and predicting spatial population dynamics in the changing world. While mortality during active movement has received much attention, few have studied the costs of passive movement such as the airborne transport of fungal spores. Here, we examine the potential of extreme environmental conditions to cause dispersal mortality in wood-decay fungi. These fungi play a key role as decomposers and habitat creators in forest ecosystems and the populations of many species have declined due to habitat loss and fragmentation. We measured the effect of simulated solar radiation (including ultraviolet A and B) and freezing at -25°C on the spore germinability of 17 species. Both treatments but especially sunlight markedly reduced spore germinability in most species, and species with thin-walled spores were particularly light sensitive. Extrapolating the species' laboratory responses to natural irradiance conditions, we predict that sunlight is a relevant source of dispersal mortality at least at larger spatial scales. In addition, we found a positive effect of spore size on spore germinability, suggesting a trade-off between dispersal distance and establishment. We conclude that freezing and particularly sunlight can be important sources of dispersal mortality in wood-decay fungi which can make it difficult for some species to colonize isolated habitat patches and habitat edges.

  8. Bait Formulations of Chlorophyllin against Infected/Uninfected Lymnaea acuminata in Red and Sunlight

    Directory of Open Access Journals (Sweden)

    Navneet Kumar

    2015-01-01

    Full Text Available Control of snail population is an important tool in fasciolosis control programme. In order to achive this objective the method of bait formulation containing an attractant and a molluscicide is an appropriate approach to ensure the death of host snail. Chlorophyllin bait pellets were prepared by addition of attractants starch (10 mM/serine (20 mM and Chlorophyllin 2% agar solution. These baits were used against host snail Lymnaea acuminata. The behavioral response of snail against attractant (starch/serine and chlorophyllin was examined in red and sunlight. The fraction of snail that was in contact with chlorophyllin bait in zone-3 was used as measure of attraction process. Infected snails were more attracted with red light+starch (57.7%. Uninfected snails were more attracted by red light+serine (58.0%. The molluscicidal activity of chlorophyllin against infected snails in red light (96h LC50-1.88% chlorophyllin in bait and sunlight (96h LC50-2.40% chlorophyllin in bait was more pronounced than uninfected snail in red light (96h LC50-1.76% Chlorophyllin in bait and sunlight (96h LC50-3.62% chlorophyllin in bait.

  9. Perfluorooctanoic acid degradation in the presence of Fe(III) under natural sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dandan [Beijing Key Laboratory of Water Resource and Environmental Engineering, China University of Geosciences, Beijing 100083 (China); Xiu, Zongming [Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005 (United States); Liu, Fei [Beijing Key Laboratory of Water Resource and Environmental Engineering, China University of Geosciences, Beijing 100083 (China); Wu, Gang [Division of Hematology, Department of Internal Medicine, University of Texas-Medical School at Houston, Houston, TX 77030 (United States); Adamson, Dave; Newell, Charles [GSI Environmental Inc., Houston, TX 77098 (United States); Vikesland, Peter [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Tsai, Ah-Lim [Division of Hematology, Department of Internal Medicine, University of Texas-Medical School at Houston, Houston, TX 77030 (United States); Alvarez, Pedro J., E-mail: alvarez@rice.edu [Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005 (United States)

    2013-11-15

    Highlights: • PFOA was photo-chemically decomposed in the presence of Fe(III) and natural sunlight. • An alternative reaction pathway involves hydroxyl radical as confirmed by EPR. • Common oxidant-persulfate increased PFOA defluorination extent. -- Abstract: Due to the high bond dissociation energy (BDE) of C-F bonds (116 kcal/mol), perfluorooctanoic acid (PFOA) is a highly recalcitrant pollutant. Herein, we demonstrate a novel method to decompose PFOA in the presence of sunlight and ferric iron (Fe(III)). Under such conditions, 97.8 ± 1.7% of 50 μM PFOA decomposed within 28 days into shorter-chain intermediates and fluoride (F{sup −}), with an overall defluorination extent of 12.7 ± 0.5%. No PFOA was removed under visible light, indicating that UV radiation is required for PFOA decomposition. Spectroscopic analysis indicates that the decomposition reaction is likely initiated by electron-transfer from PFOA to Fe(III), forming Fe(II) and an unstable organic carboxyl radical. An alternative mechanism for the formation of this organic radical involves hydroxyl radicals, detected by electron paramagnetic resonance (EPR). The observation that PFOA can be degraded by Fe(III) under solar irradiation provides mechanistic insight into a possibly overlooked natural attenuation process. Because Fe(III) is abundant in natural waters and sunlight is essentially free, this work represents a potentially important step toward the development of simple and inexpensive remediation strategies for PFOA-contaminated water.

  10. Modified optical fiber daylighting system with sunlight transportation in free space.

    Science.gov (United States)

    Vu, Ngoc-Hai; Pham, Thanh-Tuan; Shin, Seoyong

    2016-12-26

    We present the design, optical simulation, and experiment of a modified optical fiber daylighting system (M-OFDS) for indoor lighting. The M-OFDS is comprised of three sub-systems: concentration, collimation, and distribution. The concentration part is formed by coupling a Fresnel lens with a large-core plastic optical fiber. The sunlight collected by the concentration sub-system is propagated in a plastic optical fiber and then collimated by the collimator, which is a combination of a parabolic mirror and a convex lens. The collimated beam of sunlight travels in free space and is guided to the interior by directing flat mirrors, where it is diffused uniformly by a distributor. All parameters of the system are calculated theoretically. Based on the designed system, our simulation results demonstrated a maximum optical efficiency of 71%. The simulation results also showed that sunlight could be delivered to the illumination destination at distance of 30 m. A prototype of the M-OFDS was fabricated, and preliminary experiments were performed outdoors. The simulation results and experimental results confirmed that the M-OFDS was designed effectively. A large-scale system constructed by several M-OFDSs is also proposed. The results showed that the presented optical fiber daylighting system is a strong candidate for an inexpensive and highly efficient application of solar energy in buildings.

  11. Improved Flexible Transparent Conductive Electrodes based on Silver Nanowire Networks by a Simple Sunlight Illumination Approach

    Science.gov (United States)

    Kou, Pengfei; Yang, Liu; Chang, Cheng; He, Sailing

    2017-01-01

    Silver nanowire (Ag NW) networks have attracted wide attention as transparent electrodes for emerging flexible optoelectronics. However, the sheet resistance is greatly limited by large wire-to-wire contact resistances. Here, we propose a simple sunlight illumination approach to remarkably improve their electrical conductivity without any significant degradation of the light transmittance. Because the power density is extremely low (0.1 W/cm2, 1-Sun), only slight welding between Ag NWs has been observed. Despite this, a sheet resistance of <20 Ω/sq and transmittance of ~87% at wavelength of 550 nm as well as excellent mechanical flexibility have still been achieved for Ag NW networks after sunlight illumination for 1 hour or longer, which are significant upgrades over those of ITO. Slight plasmonic welding together with the associated self-limiting effect has been investigated by numerical simulations and further verified experimentally through varied solar concentrations. Due to the reduced resistance, high-performance transparent film heaters as well as efficient defrosters have been demonstrated, which are superior to the previously-reported Ag NW based film heaters. Since the sunlight is environmentally friendly and easily available, sophisticated or expensive facilities are not necessary. Our findings are particularly meaningful and show enormous potential for outdoor applications. PMID:28169343

  12. Chemically derived luminescent graphene oxide nanosheets and its sunlight driven photocatalytic activity against methylene blue dye

    Science.gov (United States)

    Kumar, Sumeet; Kumar, Ashok

    2016-12-01

    In the present work, graphene oxide (GO) nanosheets (NSs) have been synthesized with precise control over their thickness and molecular structure. The existence of oxygen containing functional groups on GO NSs through chemical treatment confers remarkable optical properties on GO. XRD, TEM, Raman and FTIR techniques were used to confirm the phase and degree of oxidation, morphology, structural information and chemical structure of the synthesized GO NSs. UV-Vis. spectroscopy was employed to study the optical absorption properties of the synthesized GO NSs. The excitation wavelength dependent PL measurements of the synthesized GO NSs were carried out which could be useful for the design and development of GO based next generation optoelectronic devices. The most fascinating luminescent property of synthesized GO NSs is that its luminescence peak position can be easily tuned by only varying the excitation wavelength without significant changes in its size and chemical composition. In order to study the photocatalytic degradation of methylene blue (MB) dye using GO NSs as a photocatalyst, a sunlight driven photocatalytic activity has been performed. The degradation rate of MB dye becomes fast when GO NSs are added to the dye solution. The photodegradation efficiency of GO NSs is calculated to be 60%. The present results indicate that synthesized GO NSs can be used as sunlight active photocatalyst. The optimistic response to sunlight irradiation validates the potential of GO NSs in solar energy conversion.

  13. An MFC capable of regenerating the cathodic electron acceptor under sunlight

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A renewable MFC (microbial fuel cell) cathode was used in this study because the iodide ion could react with oxygen to generate triiodide under natural sunlight.The feasibility of the regeneration of triiodide ion under natural sunlight and the effect of the regenerated triiodide ion concentration on the MFC performance were studied.The results showed that the power density of the MFC using triiodide ion as cathodic electron acceptor was significantly higher than that of using ferricyanate,and that the iodide ion can be oxidized to triiodide ion by oxygen in air at the expense of natural sunlight.In addition,it was obvious from the experimental results that the MFC performance was improved with the increase of the triiodide concentration,indicating that the concentration of triiodide ion had a critical effect on the MFC performance.The linear sweep voltammetry (LSV) curves for the electro-reduction of triiodide ion on the carbon paper were obtained and the results suggested that the diffusion process of triiodide ions to cathode was the control factor for the MFC performance.

  14. Combined Application of Natural Sunlight and Hydrogen peroxide on the Removal of Harmful Cyanobacteria

    Science.gov (United States)

    Wang, D. H.; Li, L.; Zhu, C. W.; Wang, Z. Y.; Xie, P.

    2017-08-01

    This study provides an efficient and environmentally friendly advanced oxidation technique involving the combined application of natural sunlight and hydrogen peroxide for the removal of harmful cyanobacteria from lakes and reservoirs. In this paper, we collected water samples from Taihu Lake (Wuxi, China) in August 2016 when cyanobacterial blooms had occurred and then performed an outdoor experiment. Hydrogen peroxide at 0.6 mM had no obvious effect on the cyanobacterial inactivation in the dark, even stimulating cyanobacterial growth to some extent. Cyanobacteria were inactivated by higher concentrations of hydrogen peroxide (1.0 mM) in the dark, as well as 0.4 mM hydrogen peroxide under sunlight irradiation, indicating that natural sunlight significantly enhanced the effect of hydrogen peroxide on the removal of cyanobacteria. An experiment involving Pseudanabaena sp. (a harmful species) led to similar conclusions as the study using algae attained from Taihu Lake. This study provides a practical and effective method for controlling harmful cyanobacteria in natural water bodies.

  15. Spectroscopic properties of Er doped and Er, Nd codoped fluoride glasses under simulated sunlight illumination

    Science.gov (United States)

    Mizuno, Shintaro; Ito, Hiroshi; Hasegawa, Kazuo; Kawai, Hiroyuki; Nasu, Hiroyuki; Hughes, Mark A.; Suzuki, Takenobu; Ohishi, Yasutake

    2011-10-01

    We investigated the fluorescence characteristics of Er codoped Nd doped ZBLAN glasses proposed for solar pumped fiber laser (SPFL) under simulated sunlight. Er is used as a sensitizer because it absorbs a part of the ultraviolet and visible light where is no absorption of Nd. Under simulated sunlight illumination, Er singly doped fluoride glass displayed four emission bands with peaks at 550, 848, 977 and 1533 nm attributed to the 4S 3/2- 4I 15/2, 4S 3/2- 4I 13/2, 4I 11/2- 4I 15/2 and 4I 13/2- 4I 15/2 electronic transitions of Er, respectively. The quantum efficiency measurement was carried out using an integrating sphere and under the simulated sunlight excitation showed a maximum of 73% for 0.5 mol.% of ErF 3 in ZBLAN glass. In Nd, Er codoped fluoride glass, the 1.05 μm emission of Nd was observed under 380 nm excitation what supposes the energy transfer from Er to Nd in ZBLAN glasses as Nd has no absorption at the wavelength. Er, Nd codoped fluoride glasses are promising as a sensitized laser media for solar pumped fiber lasers.

  16. The Effect of Prenatal Methamphetamine Exposure on Attention as Assessed by Continuous Performance Tests: Results from the Infant Development, Environment, and Lifestyle (IDEAL) Study

    Science.gov (United States)

    Kiblawi, Zeina N.; Smith, Lynne M.; LaGasse, Linda L.; Derauf, Chris; Newman, Elana; Shah, Rizwan; Arria, Amelia; Huestis, Marilyn; DellaGrotta, Sheri; Dansereau, Lynne M.; Neal, Charles; Lester, Barry

    2013-01-01

    Objective The purpose of this study is to assess for increased risk of attention deficit hyperactivity problem in young children with prenatal methamphetamine exposure from the multicenter, longitudinal Infant Development, Environment, and Lifestyle (IDEAL) study. Methods IDEAL enrolled 412 mother-infant pairs at four sites (Tulsa, OK; Des Moines, IA; Los Angeles, CA; and Honolulu, HI). Methamphetamine exposed subjects (n=204) were identified by self-report and/or gas chromatography/mass spectrometry confirmation of amphetamine and metabolites in infant meconium. Matched subjects (n=208) denied methamphetamine use and had a negative meconium screen. This analysis includes a subsample of 301 subjects that were administered the Conners’ Kiddie Continuous Performance Test (K-CPT) at age 5.5 years (153 exposed, 148 comparison). Hierarchical linear models adjusted for covariates tested exposure effects on K-CPT measures. Using the same covariates, logistic regression was used to determine the effect of exposure on the incidence of a positive ADHD confidence index score, defined as greater than 50%. Results There were no differences between the groups in omission or commission errors or reaction time for correct trials. However, methamphetamine exposure was associated with subtle differences in other outcomes predictive of ADHD, including increased slope of reaction time across blocks (p<0.001), increased variability in reaction time with longer interstimulus intervals (p<0.01), and increased likelihood of greater than 50% on the ADHD confidence index (OR 3.1, 95% CI 1.2–7.8; p=0.02). Conclusion Prenatal methamphetamine exposure was associated with subtle differences in K-CPT scores at age 5.5 years. Even at this relatively young age, these children exhibit indicators of risk for ADHD and warrant monitoring. PMID:23275056

  17. Heterotrophic bacterium Pseudomonas saponiphila and sunlight as impact factors on organo-mineral colloids transformations in boreal humic waters

    Science.gov (United States)

    Oleinikova, Olga; Drozdova, Olga; Shirokova, Liudmila; Lapitskiy, Sergey; Bychkov, Andrew; Pokrovsky, Oleg

    2017-04-01

    Two of the main factors of carbon balance in high latitudes, known to govern the CO2 flux from the lakes and rivers to the atmosphere, are bacterial mineralization (respiration) of allochthonous dissolved organic matter (DOM) and photochemical degradation of DOM. Yet, in contrast to large numbers of experimental and field studies on these factors impact on the utilization of DOM of different origin, the fate of metals bound to colloids during bacterial processing of DOM and behavior of trace element (TE) during photodegradation of DOM remains poorly constrained. This is especially important in view of essentially organic and organo-mineral colloidal status of TE in most boreal waters. To answer this questions, a monoculture of Pseudomonas saponiphila from a boreal creek in NW Karelia (Russia) was separated and allowed to interact with boreal peat leachate in nutrient-free media. We quantified colloidal transformation of the peat leachate during 5-days activity of live bacteria using 3 kDa, 50 kDa Amicon® centrifugal filtration and 0.45 µm syringe filtration. The total net decrease of the concentration of Dissolved Organic Carbon (DOC) over 93 h of exposure was within 5% of the initial value for all fractions except low molecular weight one (exposure, the DOM in stream photodegraded in a much smaller degree than that in the bog water with 25 and 60% removal of initial DOC, respectively. Specific UV absorption (SUVA254) decreased by a factor of 1.75 and 5 over 200 h of exposure in stream and bog water, respectively. The removal of Fe and Al occurred only in the bog water (90 % and 50% respectively, over 5 days of reaction), whereas no detectable decrease of Al and Fe concentration (sunlight exposure. We acknowledge support from a RFBR research projects №№ 16-55-150002 HЦHИ_a, 15-05-05000_a, 14-05-00430_a, 16-05-00542_a. Experimental study was supported by RSF № 14-50-00029.

  18. Particulate matter 2.5 (PM2.5) personal exposure evaluation on mechanics and administrative officers at the motor vehicle testing center at Pulo Gadung, DKI Jakarta.

    Science.gov (United States)

    Rizky, Zuly Prima; Yolla, Patricia Bebby; Ramdhan, Doni Hikmat

    2016-03-01

    Exposure to fine particulate matter (PM2.5) in both the short and long term has been known to cause deaths and health effects, especially related to the heart, blood vessels, and lungs. Based on this information, researchers conducted this study at a motor vehicle testing center unit at Pulo Gadung, in Jarkarta, to determine the concentration of PM2.5 that workers were exposed to. The major source of PM2.5 in this area is from the exhaust of gas emissions from motor vehicles, which is one of the largest contributors to the levels of PM in urban areas. Ten mechanics were picked from 16 mechanics that work in this station. Four administration workers from different posts were also picked to participate. The researcher conducted the PM2.5 personal exposure measurement during weekdays from 6 to 14 April 2015 (2 workers/day). This research was conducted to measure the particle number concentration with size mechanics amounted to 149.01 μm/m3 while the administrative officer group that consisted of four administrative workers were exposed to an average of 103.28 μm/m3. Once converted and compared with the World Health Organization Air Quality Guidelines, the PM2.5 exposure of the mechanics and administrative officers exceeded the recommended exposure (25 μm/m3).

  19. Early prenatal androgen exposure reduces testes size and sperm concentration in sheep without altering neuroendocrine differentiation and masculine sexual behavior.

    Science.gov (United States)

    Scully, C M; Estill, C T; Amodei, R; McKune, A; Gribbin, K P; Meaker, M; Stormshak, F; Roselli, C E

    2017-07-29

    Prenatal androgens are largely responsible for growth and differentiation of the genital tract and testis and for organization of the control mechanisms regulating male reproductive physiology and behavior. The aim of the present study was to evaluate the impact of inappropriate exposure to excess testosterone (T) during the first trimester of fetal development on the reproductive function, sexual behavior, and fertility potential of rams. We found that biweekly maternal T propionate (100 mg) treatment administered from Day 30-58 of gestation significantly decreased (P sexually attracted to estrous females. In summary, these results suggest that exposure to exogenous T during the first trimester of gestation can negatively impact spermatogenesis and compromise the reproductive fitness of rams. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. THE INFLUENCE OF SUNLIGHT AND WIND ON THE POLYCRYSTALLINE SILICON MODULES

    Directory of Open Access Journals (Sweden)

    Piotr Lichograj

    2016-12-01

    Full Text Available Changing conditions have a significant impact on the efficiency and durability of photovoltaic cells. On photovoltaic modules have also influence such external factors as temperature of the module, which changes during the long exposure to light radiation, wind, pollution and the frequency of rainfall. Parameters of PV modules provided by the manufacturers differ significantly from the results achieved under natural conditions. This work presents the laboratory study on the impact of temperature of the polycrystalline silicon module to the change of generated voltage tested with no load. Research confirms the correlation of temperature increase during the long exposure to light radiation with a voltage drop. At the same time simulation of wind causes the cooling of the module and increase the voltage circuit. Further development of research on the effects of environmental conditions will allow for accurate placement optimization of photovoltaic farms.

  1. Sun exposure may increase risk of prostate cancer in the high UV environment of New South Wales, Australia: a case-control study.

    Science.gov (United States)

    Nair-Shalliker, Visalini; Smith, David P; Egger, Sam; Hughes, Ann Maree; Kaldor, John M; Clements, Mark; Kricker, Anne; Armstrong, Bruce K

    2012-09-01

    Ultraviolet (UV) radiation in sunlight may influence risk of prostate cancer. In New South Wales (NSW), Australia, we examined the relationship between sun exposure at 30 and 50 years of age and risk of prostate cancer in a case-control study combining the NSW prostate cancer care and outcome study (cases) and the NSW non-Hodgkin's lymphoma study (controls). Prostate cancer risk increased with increasing estimated sun exposure (adjusted OR for highest vs. lowest quartiles of average weekly sun exposure in the warmer months 2.07 95% CI: 1.36-3.15) and this increase was most evident with weekend sun exposure (adjusted OR=5.55, 95% CI: 2.94-10.48). High sun sensitivity was also positively associated with risk for prostate cancer (adjusted OR=1.63, 95% CI: 1.09-2.44). The apparent effects of weekly sun exposure did not vary by disease aggressiveness. Our results suggest that increasing sun exposure in mid-adult years increases prostate cancer risk in a high ambient solar UV environment. Given that previous studies, conducted mainly in low solar UV environments, have generally found evidence of a negative association, our findings suggest there may be a U-shaped relationship between solar UV exposure and prostate cancer. Further studies are needed to test the hypothesis that high solar UV exposure is a risk factor for prostate cancer and to explore possible mechanisms for such an association.

  2. Interacting effects of sunlight, agriculturally derived dissolved organic matter and reactive oxygen species on fecal indicator bacteria growth dynamics

    Science.gov (United States)

    Bacterial survival in agriculturally impacted surface waters is dependent on resource availability and also on potential resource transformations, mediated by biotic and abiotic processes. In this study, we focused on the effect of sunlight irradiated cattle fecal extract (CFE) a...

  3. Aloe sterol supplementation improves skin elasticity in Japanese men with sunlight-exposed skin: a 12-week double-blind, randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Tanaka M

    2016-11-01

    Full Text Available Miyuki Tanaka,1 Yuki Yamamoto,2 Eriko Misawa,1 Kazumi Nabeshima,1 Marie Saito,1 Koji Yamauchi,1 Fumiaki Abe,1 Fukumi Furukawa2 1Functional Food Ingredients Department, Food Ingredients & Technology Institute, Morinaga Milk Industry Co., Ltd., Zama, Kanagawa, 2Department of Dermatology, Wakayama Medical University, Kimiidera, Wakayama, Japan Background/objective: Recently, it was confirmed that the daily oral intake of plant sterols of Aloe vera gel (Aloe sterol significantly increases the skin barrier function, moisture, and elasticity in photoprotected skin. This study aimed to investigate whether Aloe sterol intake affected skin conditions following sunlight exposure in Japanese men. Methods: We performed a 12-week, randomized, double-blind, placebo-controlled study to evaluate the effects of oral Aloe sterol supplementation on skin conditions in 48 apparently healthy men (age range: 30–59 years; average: 45 years. The subjects were instructed to expose the measurement position of the arms to the sunlight outdoors every day for 12 weeks. The skin parameters were measured at 0 (baseline, 4, 8, and 12 weeks. Results: Depending on the time for the revelation of the sunlight, the b* value and melanin index increased and the skin moisture decreased. After taking an Aloe sterol tablet daily for 12 weeks, the skin elasticity index (R2, R5, and R7 levels were significantly higher than the baseline value. There were no differences between the groups in these skin elasticity values. In the subgroup analysis of subjects aged <46 years, the change in the R5 and R7 was significantly higher in the Aloe group than in the placebo group at 8 weeks (P=0.0412 and P=0.0410, respectively. There was a difference in the quantity of sun exposure between each subject, and an additional clinical study that standardizes the amount of ultraviolet rays is warranted. No Aloe sterol intake-dependent harmful phenomenon was observed during the intake period

  4. Acute toxicity test for terrestrial hazard assessment with exposure of Folsomia candida to pesticides in an aqueous medium

    NARCIS (Netherlands)

    Houx, N.W.H.; Dekker, A.; Kammen-Polman, van A.M.M.; Ronday, R.

    1996-01-01

    An acute-toxicty test is described in which the springtail Folsomia candida was exposed to pesticides in water for four days. The test method has been designed for the direct and economical chemical analyses of all the concentrations during the execution of the test. The 96-hour EC50 values determin

  5. An effort to test the embryotoxicity of benzene, toluene, xylene, and formaldehyde to murine embryonic stem cells using airborne exposure technique.

    Science.gov (United States)

    Shen, Shuijie; Yuan, Lingmin; Zeng, Su

    2009-10-01

    Benzene, toluene, xylene, and formaldehyde are well-known indoor air pollutants, especially after house decoration. They are also common pollutants in the working places of the plastic industry, chemical industry, and leather industry. It has been reported that these pollutants cause people to be irritated, sick, experience a headache, and be dizzy. They also have the potential to induce asthma, aplastic anemia, and leukemia, even cause abortion or fetus malformation in humans. In this study, the airborne toxicity of benzene, toluene, xylene, and formaldehyde to murine embryonic stem cells (mES cells) were tested using airborne exposure technique to evaluate the mES cell airborne exposure model on embryotoxicity prediction. Briefly, mES cells were cultured on Transwell inserts and were exposed to an airborne surrounding of test chemicals in a chamber for 1 h at 37 degrees C. Cytotoxicity was determined using the MTT assay after further culture for 18 h at 37 degrees C in normal medium. The airborne IC(50) (50% inhibition concentration) of benzene, toluene, xylene, and formaldehyde derived from the fitted dose-response curves were 17,400 +/- 1290, 16,000 +/- 250, 4680 +/- 500, and 620 +/- 310 ppm, respectively. Formaldehyde was found to be the compound most toxic to mES cells compared to benzene homologues. The toxicity data had good correlation with the in vivo data. The results showed that the mES airborne exposure model may be used to predict embryotoxicity of volatile organic compounds.

  6. Synthesis of Ag-decorated porous TiO{sub 2} nanowires through a sunlight induced reduction method and its enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yun-Chang; Dai, Xin-Rong [Anhui & Huaihe river institute of hydraulic research, Hefei, Anhui 230088 (China); Hu, Xiao-Ye, E-mail: hxy821982@issp.ac.cn [Key Laboratory of Materials Physics, and Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Huang, Su-Zhen [Institute of plasma physics, Chinese Academy of Sciences, Hefei 230031 (China); Jin, Zhen, E-mail: ftbjin@hotmail.com [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

    2016-11-30

    Highlights: • The Ag-decorated porous TiO{sub 2} nanowires were succefully synthesized. • A sunlight induced ethanol reduction method for Ag decoration has been reported. • The Ag-decorated porous TiO{sub 2} nanowires exhibit excellent photocatalytic activity. • The photodegradation ratio of the as-prepared product is much higher than that of P25. - Abstract: In this work, Ag-decorated porous TiO{sub 2} nanowires were successfully synthesized via a facile and low-cost sunlight induced reduction method. The cooperation of sunlight irradiation and ethanol reduction results the formation and decoration of the Ag nanoparticles on the porous TiO{sub 2} nanowires. The structure of the Ag-decorated porous TiO{sub 2} nanowires were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Energy dispersive spectroscopy (EDS) measurements. It can be seen that the Ag nanoparticles are well dispersed within the porous TiO{sub 2} nanowires. The as-prepared Ag-decorated porous TiO{sub 2} nanowires exhibits excellent photocatalytic properties. The photocatalytic tests show that 10 ppm methylene blue can be photodegraded within 60 min. And the photodegradation ratio of the Ag-decorated porous TiO{sub 2} nanowires much higher than that of P25 and porous TiO{sub 2} nanowires. Moreover, the Ag-decorated porous TiO{sub 2} nanowires also reveal good photocatalytic activity towards to other organic pollutions, such as phenol and R6G. Therefore, it is believed that the Ag-decorated porous TiO{sub 2} nanowires can be used as a potential high performance photocatalyst in wastewater treatment.

  7. Barriers and facilitators to voluntary HIV testing uptake among communities at high risk of HIV exposure in Chennai, India.

    Science.gov (United States)

    Woodford, Michael R; Chakrapani, Venkatesan; Newman, Peter A; Shunmugam, Murali

    2015-08-28

    In India, increasing uptake of voluntary HIV testing among 'core risk groups' is a national public health priority. While HIV testing uptake has been studied among key populations in India, limited information is available on multi-level barriers and facilitators to HIV testing, and experiences with free, publicly available testing services, among key populations. We conducted 12 focus groups (n = 84) and 12 key informant interviews to explore these topics among men who have sex with men, transgender women, cisgender female sex workers, and injecting drug users in the city of Chennai. We identified inter-related barriers at social-structural, health-care system, interpersonal, and individual levels. Barriers included HIV stigma, marginalised-group stigma, discrimination in health-care settings, including government testing centres, and fears of adverse social consequences of testing HIV positive. Facilitators included outreach programmes operated by community-based/non-governmental organisations, accurate HIV knowledge and risk perception for HIV, and access to drug dependence treatment for injecting drug users. Promoting HIV testing among these key populations requires interventions at several levels: reducing HIV-related and marginalised-group stigma, addressing the fears of consequences of testing, promoting pro-testing peer and social norms, providing options for rapid and non-blood-based HIV tests, and ensuring non-judgmental and culturally competent HIV counselling and testing services.

  8. Preparation of graphene/TiO{sub 2} composites by nonionic surfactant strategy and their simulated sunlight and visible light photocatalytic activity towards representative aqueous POPs degradation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kexin; Xiong, Jingjing; Chen, Tong [Provincial Key Laboratory of Ecological Diagnosis-Remediation and Pollution Blocking Technology, Department of Environment and Chemical Engineering, Nanchang Hangkong Uuniversity, Nanchang 330063 (China); Yan, Liushui, E-mail: yanliushui1964@yahoo.cn [Provincial Key Laboratory of Ecological Diagnosis-Remediation and Pollution Blocking Technology, Department of Environment and Chemical Engineering, Nanchang Hangkong Uuniversity, Nanchang 330063 (China); Dai, Yuhua; Song, Dongyang; Lv, Ying; Zeng, Zhenxing [Provincial Key Laboratory of Ecological Diagnosis-Remediation and Pollution Blocking Technology, Department of Environment and Chemical Engineering, Nanchang Hangkong Uuniversity, Nanchang 330063 (China)

    2013-04-15

    Highlights: ► A series of graphene/TiO{sub 2} composites were developed by nonionic surfactant strategy. ► The textural property, optical property, and composition were well characterized. ► Aqueous POPs were degraded under simulated sunlight and visible light irradiation. ► The degradation mechanism and kinetics of aqueous POPs were studied in detail. ► Mineralization of aqueous POPs and recyclability of the composites were also tested. -- Abstract: A series of graphene/TiO{sub 2} composites were fabricated using a single-step nonionic surfactant strategy combined with the solvothermal treatment technique. Their phase structure, morphology, porosity, optical absorption property, as well as composition and structure, were characterized. The as-prepared composites were successfully applied to degrade aqueous persistent organic pollutants (POPs) such as rhodamine B, aldicarb, and norfloxacin in simulated sunlight (λ > 320 nm) and visible light (λ > 400 nm) irradiation. The degradation mechanism and kinetics of aqueous POPs were studied in detail. The mineralization of aqueous POPs and the recyclability of the composites were also tested in the same condition.

  9. A sunlight-induced method for rapid biosynthesis of silver nanoparticles using an Andrachnea chordifolia ethanol extract

    Science.gov (United States)

    Karimi Zarchi, A. A.; Mokhtari, N.; Arfan, M.; Rehman, T.; Ali, M.; Amini, M.; Faridi Majidi, R.; Shahverdi, A. R.

    2011-05-01

    In this study a sunlight-induced method for rapid synthesis of silver nanoparticles using an ethanol extract of Andrachnea chordifolia is described. The silver nitrate solutions (1 mM) containing the ethanol extract of Andrachnea chordifolia were irradiated by both sunlight radiation and by sunlight radiation passed through different colored filters (red, yellow or green). The smallest size of silver nanoparticles was obtained when a silver ion solution was irradiated for 5 minutes by direct sunlight radiation. Further examination of the shape and size and of the surface chemistry of these biogenic silver nanoparticles, which were prepared under sunlight radiation, was carried out using transmission electron microscopy and infrared spectroscopy, respectively. Transmission electron microscopy images show spherical particles with an average size of 3.4 nm. Hydroxyl residues were also detected on the surface of these biogenic silver nanoparticles fabricated using plant extract of Andrachnea chordifolia under sunlight radiation. Our study on the reduction of silver ions by this plant extract in darkness shows that the synthesis process can take place under dark conditions at much longer incubations (48 hours). Larger silver polydispersed nanoparticles ranging in size from 3 to 30 nm were obtained when the silver ions were treated with the ethanol extract of Andrachnea chordifolia under dark conditions for 48 hours.

  10. A sunlight-induced method for rapid biosynthesis of silver nanoparticles using an Andrachnea chordifolia ethanol extract

    Energy Technology Data Exchange (ETDEWEB)

    Karimi Zarchi, A.A.; Faridi Majidi, R. [Tehran University of Medical Sciences, Department of Nanomedicine, School of Advanced Medical Technologies, Tehran (Iran, Islamic Republic of); Mokhtari, N.; Shahverdi, A.R. [Tehran University of Medical Sciences, Department of Pharmaceutical Biotechnology and Medicinal Plants Research Center, Faculty of Pharmacy, Tehran (Iran, Islamic Republic of); Arfan, M.; Rehman, T.; Ali, M. [University of Peshawar, Institute of Chemical Sciences, Peshawar, Khyber Pakhtoonkhwa (Pakistan); Amini, M. [Tehran University of Medical Sciences, Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran (Iran, Islamic Republic of)

    2011-05-15

    In this study a sunlight-induced method for rapid synthesis of silver nanoparticles using an ethanol extract of Andrachnea chordifolia is described. The silver nitrate solutions (1 mM) containing the ethanol extract of Andrachnea chordifolia were irradiated by both sunlight radiation and by sunlight radiation passed through different colored filters (red, yellow or green). The smallest size of silver nanoparticles was obtained when a silver ion solution was irradiated for 5 minutes by direct sunlight radiation. Further examination of the shape and size and of the surface chemistry of these biogenic silver nanoparticles, which were prepared under sunlight radiation, was carried out using transmission electron microscopy and infrared spectroscopy, respectively. Transmission electron microscopy images show spherical particles with an average size of 3.4 nm. Hydroxyl residues were also detected on the surface of these biogenic silver nanoparticles fabricated using plant extract of Andrachnea chordifolia under sunlight radiation. Our study on the reduction of silver ions by this plant extract in darkness shows that the synthesis process can take place under dark conditions at much longer incubations (48 hours). Larger silver polydispersed nanoparticles ranging in size from 3 to 30 nm were obtained when the silver ions were treated with the ethanol extract of Andrachnea chordifolia under dark conditions for 48 hours. (orig.)

  11. One dimensional CdS nanowire@TiO2 nanoparticles core-shell as high performance photocatalyst for fast degradation of dye pollutants under visible and sunlight irradiation.

    Science.gov (United States)

    Arabzadeh, Abbas; Salimi, Abdollah

    2016-10-01

    In this study, one-dimensional CdS nanowires@TiO2 nanoparticles core-shell structures (1D CdS NWs@TiO2 NPs) were synthesized by a facile wet chemical-solvothermal method. The different aspects of the properties of CdS NWs@TiO2 NPs were surveyed by using a comprehensive range of characterization techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis spectroscopy, scanning electron microscopy (SEM), fluorescence spectroscopy, energy dispersive X-ray spectroscopy (EDX), Cyclic Voltammetry (CV) and amperometry. The as-prepared nanostructure was applied as an effective photocatalyst for degradation of methyl orange (MO), methylene blue (MB) and rhodamine B (Rh B) under visible and sunlight irradiation. The results indicated significantly enhanced photocatalytic activity of CdS NWs@TiO2 NPs for degradation of MO, MB and Rh B compared to CdS NWs. The enhanced photocatalytic activity could be attributed to the enhanced sunlight absorbance and the efficient charge separation of the formed heterostructure between CdS NWs and TiO2. The results showed that MO, Rh B and MB were almost completely degraded after 2, 2 and 3min of